Sample records for microchannel heat exchanger

  1. Active microchannel heat exchanger

    DOE Patents [OSTI]

    Tonkovich, Anna Lee Y. (Pasco, WA) [Pasco, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Call, Charles J. (Pasco, WA) [Pasco, WA; Wegeng, Robert S. (Richland, WA) [Richland, WA; Wang, Yong (Richland, WA) [Richland, WA

    2001-01-01T23:59:59.000Z

    The present invention is an active microchannel heat exchanger with an active heat source and with microchannel architecture. The microchannel heat exchanger has (a) an exothermic reaction chamber; (b) an exhaust chamber; and (c) a heat exchanger chamber in thermal contact with the exhaust chamber, wherein (d) heat from the exothermic reaction chamber is convected by an exothermic reaction exhaust through the exhaust chamber and by conduction through a containment wall to the working fluid in the heat exchanger chamber thereby raising a temperature of the working fluid. The invention is particularly useful as a liquid fuel vaporizer and/or a steam generator for fuel cell power systems, and as a heat source for sustaining endothermic chemical reactions and initiating exothermic reactions.

  2. Microchannel Heat Exchangers with Carbon Dioxide

    SciTech Connect (OSTI)

    Zhao, Y.; Ohadi, M.M.; Radermacher, R.

    2001-09-15T23:59:59.000Z

    The objective of the present study was to determine the performance of CO{sub 2} microchannel evaporators and gas coolers in operational conditions representing those of residential heat pumps. A set of breadboard prototype microchannel evaporators and gas coolers was developed and tested. The refrigerant in the heat exchangers followed a counter cross-flow path with respect to the airflow direction. The test conditions corresponded to the typical operating conditions of residential heat pumps. In addition, a second set of commercial microchannel evaporators and gas coolers was tested for a less comprehensive range of operating conditions. The test results were reduced and a comprehensive data analysis, including comparison with the previous studies in this field, was performed. Capacity and pressure drop of the evaporator and gas cooler for the range of parameters studied were analyzed and are documented in this report. A gas cooler performance prediction model based on non-dimensional parameters was also developed and results are discussed as well. In addition, in the present study, experiments were conducted to evaluate capacities and pressure drops for sub-critical CO{sub 2} flow boiling and transcritical CO{sub 2} gas cooling in microchannel heat exchangers. An extensive review of the literature failed to indicate any previous systematic study in this area, suggesting a lack of fundamental understanding of the phenomena and a lack of comprehensive data that would quantify the performance potential of CO{sub 2} microchannel heat exchangers for the application at hand. All experimental tests were successfully conducted with an energy balance within {+-}3%. The only exceptions to this were experiments at very low saturation temperatures (-23 C), where energy balances were as high as 10%. In the case of evaporators, it was found that a lower saturation temperature (especially when moisture condensation occurs) improves the overall heat transfer coefficient significantly. However, under such conditions, air side pressure drop also increases when moisture condensation occurs. An increase in airflow rate also increases the overall heat transfer coefficient. Air side pressure drop mainly depends on airflow rate. For the gas cooler, a significant portion of the heat transfer occurred in the first heat exchanger module on the refrigerant inlet side. The temperature and pressure of CO{sub 2} significantly affect the heat transfer and fluid flow characteristics due to some important properties (such as specific heat, density, and viscosity). In the transcritical region, performance of CO{sub 2} strongly depends on the operating temperature and pressure. Semi-empirical models were developed for predictions of CO{sub 2} evaporator and gas cooler system capacities. The evaporator model introduced two new factors to account for the effects of air-side moisture condensate and refrigerant outlet superheat. The model agreed with the experimental results within {+-}13%. The gas cooler model, based on non-dimensional parameters, successfully predicted the experimental results within {+-}20%. Recommendations for future work on this project include redesigning headers and/or introducing flow mixers to avoid flow mal-distribution problems, devising new defrosting techniques, and improving numerical models. These recommendations are described in more detail at the end of this report.

  3. Low-Cost Microchannel Heat Exchanger

    Broader source: Energy.gov (indexed) [DOE]

    Produce prototype heat exchangers for electronics cooling and high pressure waste heat recovery power system applications Test integrity and confirm high performance of...

  4. Diffusion-Welded Microchannel Heat Exchanger for Industrial Processes

    SciTech Connect (OSTI)

    Piyush Sabharwall; Denis E. Clark; Michael V. Glazoff; Michael G. McKellar; Ronald E. Mizia

    2013-03-01T23:59:59.000Z

    The goal of next generation reactors is to increase energy ef?ciency in the production of electricity and provide high-temperature heat for industrial processes. The ef?cient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process. The need for ef?ciency, compactness, and safety challenge the boundaries of existing heat exchanger technology. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more ef?cient industrial processes. Modern compact heat exchangers can provide high compactness, a measure of the ratio of surface area-to-volume of a heat exchange. The microchannel heat exchanger studied here is a plate-type, robust heat exchanger that combines compactness, low pressure drop, high effectiveness, and the ability to operate with a very large pressure differential between hot and cold sides. The plates are etched and thereafter joined by diffusion welding, resulting in extremely strong all-metal heat exchanger cores. After bonding, any number of core blocks can be welded together to provide the required ?ow capacity. This study explores the microchannel heat exchanger and draws conclusions about diffusion welding/bonding for joining heat exchanger plates, with both experimental and computational modeling, along with existing challenges and gaps. Also, presented is a thermal design method for determining overall design speci?cations for a microchannel printed circuit heat exchanger for both supercritical (24 MPa) and subcritical (17 MPa) Rankine power cycles.

  5. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOE Patents [OSTI]

    Swift, Gregory W. (Los Alamos, NM); Migliori, Albert (Santa Fe, NM); Wheatley, John C. (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.

  6. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOE Patents [OSTI]

    Swift, G.W.; Migliori, A.; Wheatley, J.C.

    1985-05-14T23:59:59.000Z

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance. 9 figs.

  7. Microchannel crossflow fluid heat exchanger and method for its fabrication

    DOE Patents [OSTI]

    Swift, G.W.; Migliori, A.; Wheatley, J.C.

    1982-08-31T23:59:59.000Z

    A microchannel crossflow fluid heat exchanger and a method for its fabrication are disclosed. The heat exchanger is formed from a stack of thin metal sheets which are bonded together. The stack consists of alternating slotted and unslotted sheets. Each of the slotted sheets includes multiple parallel slots which form fluid flow channels when sandwiched between the unslotted sheets. Successive slotted sheets in the stack are rotated ninety degrees with respect to one another so as to form two sets of orthogonally extending fluid flow channels which are arranged in a crossflow configuration. The heat exchanger has a high surface to volume ratio, a small dead volume, a high heat transfer coefficient, and is suitable for use with fluids under high pressures. The heat exchanger has particular application in a Stirling engine that utilizes a liquid as the working substance.

  8. Experimentally validated models of refrigerant distribution in microchannel heat exchangers used to evaluate charge reduction of various working fluids.

    E-Print Network [OSTI]

    Padilla, Yadira

    2012-01-01T23:59:59.000Z

    ??This thesis presents experimentally validated simulation models developed to obtain accurate prediction of microchannel heat exchanger performance and charge. Effects of using various correlations are (more)

  9. Microchannel heat sink assembly

    DOE Patents [OSTI]

    Bonde, W.L.; Contolini, R.J.

    1992-03-24T23:59:59.000Z

    The present invention provides a microchannel heat sink with a thermal range from cryogenic temperatures to several hundred degrees centigrade. The heat sink can be used with a variety of fluids, such as cryogenic or corrosive fluids, and can be operated at a high pressure. The heat sink comprises a microchannel layer preferably formed of silicon, and a manifold layer preferably formed of glass. The manifold layer comprises an inlet groove and outlet groove which define an inlet manifold and an outlet manifold. The inlet manifold delivers coolant to the inlet section of the microchannels, and the outlet manifold receives coolant from the outlet section of the microchannels. In one embodiment, the manifold layer comprises an inlet hole extending through the manifold layer to the inlet manifold, and an outlet hole extending through the manifold layer to the outlet manifold. Coolant is supplied to the heat sink through a conduit assembly connected to the heat sink. A resilient seal, such as a gasket or an O-ring, is disposed between the conduit and the hole in the heat sink in order to provide a watertight seal. In other embodiments, the conduit assembly may comprise a metal tube which is connected to the heat sink by a soft solder. In still other embodiments, the heat sink may comprise inlet and outlet nipples. The present invention has application in supercomputers, integrated circuits and other electronic devices, and is suitable for cooling materials to superconducting temperatures. 13 figs.

  10. DEVELOPMENT OF A UHT WATER PASTEURIZATION SYSTEM USING MICROCHANNEL HEAT EXCHANGER TECHNOLOGY

    E-Print Network [OSTI]

    Escher, Christine

    stages of proposal development for DaVita, leveraging the OSU Venture Fund money for a small-scale system+ that a small-scale system is feasible with microchannel technology. These past activities, as footnoted below, significant interest exists in a stand-alone water purification system in the 1000 ml

  11. Carbon nanotube heat-exchange systems

    DOE Patents [OSTI]

    Hendricks, Terry Joseph (Arvada, CO); Heben, Michael J. (Denver, CO)

    2008-11-11T23:59:59.000Z

    A carbon nanotube heat-exchange system (10) and method for producing the same. One embodiment of the carbon nanotube heat-exchange system (10) comprises a microchannel structure (24) having an inlet end (30) and an outlet end (32), the inlet end (30) providing a cooling fluid into the microchannel structure (24) and the outlet end (32) discharging the cooling fluid from the microchannel structure (24). At least one flow path (28) is defined in the microchannel structure (24), fluidically connecting the inlet end (30) to the outlet end (32) of the microchannel structure (24). A carbon nanotube structure (26) is provided in thermal contact with the microchannel structure (24), the carbon nanotube structure (26) receiving heat from the cooling fluid in the microchannel structure (24) and dissipating the heat into an external medium (19).

  12. Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel

    E-Print Network [OSTI]

    Aussillous, Pascale

    Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow

  13. Innovative heat removal structure for power devices -the drift region integrated microchannel cooler

    E-Print Network [OSTI]

    Boyer, Edmond

    Innovative heat removal structure for power devices - the drift region integrated microchannel is approved to be a compact and high-performance solution to deal with the thermal requirements of power devices and modules. This is due to the large heat exchange surface, the high heat transfer coefficient

  14. Corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, Scott L. (Annandale, VA)

    1989-01-01T23:59:59.000Z

    A corrosive and errosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is conveyed through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium.

  15. Heat exchanger

    DOE Patents [OSTI]

    Brackenbury, P.J.

    1983-12-08T23:59:59.000Z

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  16. Heat exchanger

    DOE Patents [OSTI]

    Brackenbury, Phillip J. (Richland, WA)

    1986-01-01T23:59:59.000Z

    A heat exchanger comparising a shell attached at its open end to one side of a tube sheet and a detachable head connected to the other side of said tube sheet. The head is divided into a first and second chamber in fluid communication with a nozzle inlet and nozzle outlet, respectively, formed in said tube sheet. A tube bundle is mounted within said shell and is provided with inlets and outlets formed in said tube sheet in communication with said first and second chambers, respectively.

  17. Hydrodynamics, heat transfer and flow boiling instabilities in microchannels

    E-Print Network [OSTI]

    Barber, Jacqueline Claire

    2010-01-01T23:59:59.000Z

    Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...

  18. Segmented heat exchanger

    DOE Patents [OSTI]

    Baldwin, Darryl Dean (Lafayette, IN); Willi, Martin Leo (Dunlap, IL); Fiveland, Scott Byron (Metamara, IL); Timmons, Kristine Ann (Chillicothe, IL)

    2010-12-14T23:59:59.000Z

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  19. Heat pipe array heat exchanger

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1987-08-25T23:59:59.000Z

    A heat pipe arrangement for exchanging heat between two different temperature fluids. The heat pipe arrangement is in a ounterflow relationship to increase the efficiency of the coupling of the heat from a heat source to a heat sink.

  20. Heat Integrated Distillation through Use of Microchannel Technology

    Broader source: Energy.gov [DOE]

    This factsheet describes a research project whose goal is to develop a breakthrough distillation process using Microchannel Process Technology to integrate heat transfer and separation into a single unit operation.

  1. Microchannel laminated mass exchanger and method of making

    DOE Patents [OSTI]

    Martin, Peter M. (Kennewick, WA); Bennett, Wendy D. (Kennewick, WA); Matson, Dean W. (Kennewick, WA); Stewart, Donald C. (Richland, WA); Drost, Monte K. (Pasco, WA); Wegeng, Robert S. (Richland, WA); Perez, Joseph M. (Richland, WA); Feng, Xiangdong (West Richland, WA); Liu, Jun (West Richland, WA)

    2000-01-01T23:59:59.000Z

    The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

  2. Microchannel laminated mass exchanger and method of making

    DOE Patents [OSTI]

    Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

    2003-03-18T23:59:59.000Z

    The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

  3. Microchannel laminated mass exchanger and method of making

    DOE Patents [OSTI]

    Martin, Peter M [Kennewick, WA; Bennett, Wendy D [Kennewick, WA; Matson, Dean W [Kennewick, WA; Stewart, Donald C [Richland, WA; Drost, Monte K [Pasco, WA; Wegeng, Robert S [Richland, WA; Perez, Joseph M [Richland, WA; Feng, Xiangdong [West Richland, WA; Liu, Jun [West Richland, WA

    2002-03-05T23:59:59.000Z

    The present invention is a microchannel mass exchanger having a first plurality of inner thin sheets and a second plurality of outer thin sheets. The inner thin sheets each have a solid margin around a circumference, the solid margin defining a slot through the inner thin sheet thickness. The outer thin sheets each have at least two header holes on opposite ends and when sandwiching an inner thin sheet. The outer thin sheets further have a mass exchange medium. The assembly forms a closed flow channel assembly wherein fluid enters through one of the header holes into the slot and exits through another of the header holes after contacting the mass exchange medium.

  4. Woven heat exchanger

    DOE Patents [OSTI]

    Piscitella, R.R.

    1984-07-16T23:59:59.000Z

    This invention relates to a heat exchanger for waste heat recovery from high temperature industrial exhaust streams. In a woven ceramic heat exchanger using the basic tube-in-shell design, each heat exchanger consisting of tube sheets and tube, is woven separately. Individual heat exchangers are assembled in cross-flow configuration. Each heat exchanger is woven from high temperature ceramic fiber, the warp is continuous from tube to tube sheet providing a smooth transition and unitized construction.

  5. Direct fired heat exchanger

    SciTech Connect (OSTI)

    Reimann, Robert C. (Lafayette, NY); Root, Richard A. (Spokane, WA)

    1986-01-01T23:59:59.000Z

    A gas-to-liquid heat exchanger system which transfers heat from a gas, generally the combustion gas of a direct-fired generator of an absorption machine, to a liquid, generally an absorbent solution. The heat exchanger system is in a counterflow fluid arrangement which creates a more efficient heat transfer.

  6. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2007-09-18T23:59:59.000Z

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  7. Heat and mass exchanger

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc J. (Princeton, NJ); Miller, Jeffrey A. (Hopewell, NJ); Tonon, Thomas (Princeton, NJ)

    2011-06-28T23:59:59.000Z

    A mass and heat exchanger includes at least one first substrate with a surface for supporting a continuous flow of a liquid thereon that either absorbs, desorbs, evaporates or condenses one or more gaseous species from or to a surrounding gas; and at least one second substrate operatively associated with the first substrate. The second substrate includes a surface for supporting the continuous flow of the liquid thereon and is adapted to carry a heat exchange fluid therethrough, wherein heat transfer occurs between the liquid and the heat exchange fluid.

  8. Thermoelectric heat exchange element

    DOE Patents [OSTI]

    Callas, James J. (Peoria, IL); Taher, Mahmoud A. (Peoria, IL)

    2007-08-14T23:59:59.000Z

    A thermoelectric heat exchange module includes a first substrate including a heat receptive side and a heat donative side and a series of undulatory pleats. The module may also include a thermoelectric material layer having a ZT value of 1.0 or more disposed on at least one of the heat receptive side and the heat donative side, and an electrical contact may be in electrical communication with the thermoelectric material layer.

  9. A corrosive resistant heat exchanger

    DOE Patents [OSTI]

    Richlen, S.L.

    1987-08-10T23:59:59.000Z

    A corrosive and erosive resistant heat exchanger which recovers heat from a contaminated heat stream. The heat exchanger utilizes a boundary layer of innocuous gas, which is continuously replenished, to protect the heat exchanger surface from the hot contaminated gas. The innocuous gas is pumped through ducts or perforations in the heat exchanger wall. Heat from the heat stream is transferred by radiation to the heat exchanger wall. Heat is removed from the outer heat exchanger wall by a heat recovery medium. 3 figs., 3 tabs.

  10. Low-Cost Microchannel Heat Exchanger

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector General Office0-72.pdfGeorgeDoesn't Happen

  11. MICROCHANNEL EXPANDED HEAT EXCHANGER - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fund Las ConchasTrail of aMEEM Energy FrontierAMONGPHYSICS

  12. Microchannel devices

    SciTech Connect (OSTI)

    Alman, David E.; Wilson, Rick D.

    2001-09-01T23:59:59.000Z

    The fabrication of stainless steel microchannel heat exchangers was examined through microlamination, the process of diffusion bonding precision machined metallic foils. The influence of diffusion bonding parameters, as well as the device geometry on the strength of the bond between the foils and embedded channel integrity, was investigated. During diffusion bonding, high temperatures and/or pressures result in well bonded foils, but these conditions cause the embedded channels to deform, which will degrade the efficiency of fluid flow through the channels. Alternatively, low temperatures and/or pressures result in undeformed channels but weakly bonded foils. This causes failure of the device due to fluid leakage. Thus, a processing envelope exists for producing a sound device with no fluid leakage and no degradation of fluid flow properties. The theoretical limit on aspect ratio within two-fluid counter-flow microchannel heat exchangers was also investigated. A counter-flow device is comprised of alternating layers of microchannels, which allow the two fluids to flow in opposite directions separated by fins. A theoretical model for interpreting the span of the fin as a function of the fin thickness was established. The model was verified experimentally by fabricating specimens to simulate the counter-flow device. The results of these investigations were used to aid in the design and processing of prototype microchannel devices.

  13. Radial flow heat exchanger

    DOE Patents [OSTI]

    Valenzuela, Javier (Hanover, NH)

    2001-01-01T23:59:59.000Z

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  14. Proceedings: Heat exchanger workshop

    SciTech Connect (OSTI)

    Not Available

    1987-07-01T23:59:59.000Z

    Heat transfer processes are of controlling importance in the operation of a thermal power plant. Heat exchangers are major cost items and are an important source of problems causing poor power plant availability and performance. A workshop to examine the improvements that can be made to heat exchangers was sponsored by the Electric Power Research Institute (EPRI) on June 10-11, 1986, in Palo Alto, California. This workshop was attended by 25 engineers and scientists representing EPRI-member utilities and EPRI consultants. A forum was provided for discussions related to the design, operation and maintenance of utility heat transfer equipment. The specific objectives were to identify research directions that could significantly improve heat exchanger performance, reliability and life cycle economics. Since there is a great diversity of utility heat transfer equipment in use, this workshop addressed two equipment categories: Boiler Feedwater Heaters (FWH) and Heat Recovery Steam Generators (HRSG). The workshop was divided into the following panel sessions: functional design, mechanical design, operation, suggested research topics, and prioritization. Each panel session began with short presentations by experts on the subject and followed by discussions by the attendees. This report documents the proceedings of the workshop and contains recommendations of potentially valuable areas of research and development. 4 figs.

  15. Sandia National Laboratories: Heat Exchanger Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    LabHeat Exchanger Development Heat Exchanger Development Planned Heat Exchanger Test Loop Capabilities Heat Exchanger 1 500 kW Heaters (Elec.) 500 kW Gas Cooler Unbalanced flows...

  16. Optimization of Heat Exchanger Cleaning

    E-Print Network [OSTI]

    Siegell, J. H.

    decrease models of the heat recovery decay. A mathematical comparison of mechanical and chemical cleaning of heat exchangers has identified the most significant parameters which affect the choice between the two methods. INTRODUCTION In most... can be somewhat mitigated by periodic chemical or mechanical cleaning of the exchanger surface, and by the addition of antifoul ants. The typical decay in heat recovery capabil ity due to fou 1i ng and restoration afte r heat exchanger cleaning...

  17. SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke

    E-Print Network [OSTI]

    Kandlikar, Satish

    SINGLE-PHASE LIQUID HEAT TRANSFER IN PLAIN AND ENHANCED MICROCHANNELS Mark E. Steinke Systems upon the understanding of the fundamental heat transfer processes that occur in these systems. There have been great advancements in our understanding of the heat transfer and fluid flow mechanisms

  18. Joule heating effects on electrokinetic focusing and trapping of particles in constriction microchannels

    E-Print Network [OSTI]

    Xuan, Xiangchun "Schwann"

    Joule heating effects on electrokinetic focusing and trapping of particles in constriction for more Home Search Collections Journals About Contact us My IOPscience #12;IOP PUBLISHING JOURNAL.1088/0960-1317/22/7/075011 Joule heating effects on electrokinetic focusing and trapping of particles in constriction microchannels

  19. High Temperature Heat Exchanger Project

    SciTech Connect (OSTI)

    Anthony E. Hechanova, Ph.D.

    2008-09-30T23:59:59.000Z

    The UNLV Research Foundation assembled a research consortium for high temperature heat exchanger design and materials compatibility and performance comprised of university and private industry partners under the auspices of the US DOE-NE Nuclear Hydrogen Initiative in October 2003. The objectives of the consortium were to conduct investigations of candidate materials for high temperature heat exchanger componets in hydrogen production processes and design and perform prototypical testing of heat exchangers. The initial research of the consortium focused on the intermediate heat exchanger (located between the nuclear reactor and hydrogen production plan) and the components for the hydrogen iodine decomposition process and sulfuric acid decomposition process. These heat exchanger components were deemed the most challenging from a materials performance and compatibility perspective

  20. Modular heat exchanger

    DOE Patents [OSTI]

    Giardina, Angelo R. [Marple Township, Delaware County, PA

    1981-03-03T23:59:59.000Z

    A shell and tube heat exchanger having a plurality of individually removable tube bundle modules. A lattice of structural steel forming rectangular openings therein is placed at each end of a cylindrical shell. Longitudinal structural members are placed in the shell between corners of the rectangular openings situated on opposite ends of the shell. Intermediate support members interconnect the longitudinal supports so as to increase the longitudinal supports rigidity. Rectangular parallelpiped tube bundle moldules occupy the space defined by the longitudinal supports and end supports and each include a rectangular tube sheet situated on each end of a plurality of tubes extending therethrough, a plurality of rectangular tube supports located between the tube sheets, and a tube bundle module stiffening structure disposed about the bundle's periphery and being attached to the tube sheets and tube supports. The corners of each tube bundle module have longitudinal framework members which are mateable with and supported by the longitudinal support members. Intermediate support members constitute several lattice, each of which is situate d in a plane between the end support members. The intermediate support members constituting the several lattice extend horizontally and vertically between longitudinal supports of adjacent tube module voids. An alternative embodiment for intermediate support members constitute a series of structural plates situated at the corners of the module voids and having recesses therein for receiving the respective longitudinal support members adjacent thereto, protrusions separating the recesses, and a plurality of struts situated between protrusions of adjacent structural plates.

  1. Heat exchanger using graphite foam

    DOE Patents [OSTI]

    Campagna, Michael Joseph; Callas, James John

    2012-09-25T23:59:59.000Z

    A heat exchanger is disclosed. The heat exchanger may have an inlet configured to receive a first fluid and an outlet configured to discharge the first fluid. The heat exchanger may further have at least one passageway configured to conduct the first fluid from the inlet to the outlet. The at least one passageway may be composed of a graphite foam and a layer of graphite material on the exterior of the graphite foam. The layer of graphite material may form at least a partial barrier between the first fluid and a second fluid external to the at least one passageway.

  2. Heat exchanger with ceramic elements

    DOE Patents [OSTI]

    Corey, John A. (North Troy, NY)

    1986-01-01T23:59:59.000Z

    An annular heat exchanger assembly includes a plurality of low thermal growth ceramic heat exchange members with inlet and exit flow ports on distinct faces. A mounting member locates each ceramic member in a near-annular array and seals the flow ports on the distinct faces into the separate flow paths of the heat exchanger. The mounting member adjusts for the temperature gradient in the assembly and the different coefficients of thermal expansion of the members of the assembly during all operating temperatures.

  3. Dependency of Heat Transfer Rate on the Brinkman Number in Microchannels

    E-Print Network [OSTI]

    H. S. Park

    2008-01-07T23:59:59.000Z

    Heat generation from electronics increases with the advent of high-density integrated circuit technology. To come up with the heat generation, microscale cooling has been thought as a promising technology. Prediction of heat transfer rate is crucial in design of microscale cooling device but is not clearly understood yet. This work proposes a new correlation between heat transfer rate and Brinkman number which is nondimensional number of viscosity, flow velocity and temperature. It is expected that the equation proposed by this work can be useful to design microchannel cooling device.

  4. 2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in

    E-Print Network [OSTI]

    Maruyama, Shigeo

    2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level

  5. OPTIMIZATION AND DESIGN GUIDELINES FOR HIGH FLUX MICRO-CHANNEL HEAT SINKS FOR LIQUID AND GASEOUS SINGLE-PHASE FLOW

    E-Print Network [OSTI]

    Müller, Norbert

    forced convection micro-channel heat sinks for minimum pump power at high heat fluxes. Results gained orders of magnitude, especially for high heat flux devices. Using water and air as coolants, designs for heat fluxes of >10 kW/cm2 and >100 W/cm2 respectively with pump/fan power expenses less than 1

  6. Ceramic heat exchanger

    DOE Patents [OSTI]

    LaHaye, P.G.; Rahman, F.H.; Lebeau, T.P.; Severin, B.K.

    1998-06-16T23:59:59.000Z

    A tube containment system is disclosed. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture. 6 figs.

  7. Ceramic heat exchanger

    DOE Patents [OSTI]

    LaHaye, Paul G. (Kennebunk, ME); Rahman, Faress H. (Portland, ME); Lebeau, Thomas P. E. (Portland, ME); Severin, Barbara K. (Biddeford, ME)

    1998-01-01T23:59:59.000Z

    A tube containment system. The tube containment system does not significantly reduce heat transfer through the tube wall. The contained tube is internally pressurized, and is formed from a ceramic material having high strength, high thermal conductivity, and good thermal shock resistance. The tube containment system includes at least one ceramic fiber braid material disposed about the internally pressurized tube. The material is disposed about the tube in a predetermined axial spacing arrangement. The ceramic fiber braid is present in an amount sufficient to contain the tube if the tube becomes fractured. The tube containment system can also include a plurality of ceramic ring-shaped structures, in contact with the outer surface of the tube, and positioned between the tube and the ceramic fiber braid material, and/or at least one transducer positioned within tube for reducing the internal volume and, therefore, the energy of any shrapnel resulting from a tube fracture.

  8. Light weight and economical exhaust heat exchanger for waste...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    exhaust heat exchanger for waste heat recovery using mixed radiant and convective heat transfer Light weight and economical exhaust heat exchanger for waste heat recovery...

  9. Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method

    E-Print Network [OSTI]

    Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non the results of experimental and numerical studies concerning boiling heat transfer inside vertical in minichannels for several gravity levels (µg, 1g, 2g). To fully understand the high heat transfer potential

  10. Second Law Optimization of Heat Exchangers

    E-Print Network [OSTI]

    Witte, L. C.

    A new method for optimizing heat exchangers is developed in this paper. It is based on second law efficiency relationships rather than on the traditional heat exchanger effectiveness concept. The cost of energy is based on its availability level...

  11. Condensing Heat Exchangers Optimize Steam Boilers

    E-Print Network [OSTI]

    Sullivan, B.; Sullivan, P. A.

    1983-01-01T23:59:59.000Z

    for Industrial Boilers" R. E. Thompson - R. J. Goldstick KVB, Inc., 18806 Skypark Blvd., Irvine, California 92714, pg. 12-4. (3) "Condensing Heat Exchangers Using Tenon R Covered Tubes", Ronald Hessen, Condensing Heat Exchanger Corp., Latham, New York...

  12. Synergistic diffuser/heat-exchanger design

    E-Print Network [OSTI]

    Lazzara, David S. (David Sergio), 1980-

    2004-01-01T23:59:59.000Z

    The theoretical and numerical evaluation of synergistic diffusing heat-exchanger design is presented. Motivation for this development is based on current diffuser and heat-exchange technologies in cogeneration plants, which ...

  13. THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERS

    E-Print Network [OSTI]

    Mertol, Atila

    2012-01-01T23:59:59.000Z

    The Performance of Solar Water Heater With Natural Ci rcul2-6, 1980 THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERSJune 1980 THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERS*

  14. IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER

    E-Print Network [OSTI]

    IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS #12;ii IMPLEMENTING GROUND SOURCE HEAT PUMP AND GROUND LOOP HEAT EXCHANGER MODELS IN THE ENERGYPLUS............................................................... 2 1.3. Overview of the Parameter Estimation Water-to-Water Heat Pump Model ........... 5 1

  15. Efficient, Low-cost Microchannel Heat Exchanger - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinanInformation Desert Southwest Region service area. TheEPSCI Home It is the| Center for GasVehicles and

  16. NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger

    SciTech Connect (OSTI)

    Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

    2008-09-01T23:59:59.000Z

    One key long-standing issue that must be overcome to fully realize the successful growth of nuclear power is to determine other benefits of nuclear energy apart from meeting the electricity demands. The Next Generation Nuclear Plant (NGNP) will most likely be producing electricity and heat for the production of hydrogen and/or oil retrieval from oil sands and oil shale to help in our national pursuit of energy independence. For nuclear process heat to be utilized, intermediate heat exchange is required to transfer heat from the NGNP to the hydrogen plant or oil recovery field in the most efficient way possible. Development of nuclear reactor - process heat technology has intensified the interest in liquid metals as heat transfer media because of their ideal transport properties. Liquid metal heat exchangers are not new in practical applications. An important rational for considering liquid metals is the potential convective heat transfer is among the highest known. Thus explains the interest in liquid metals as coolant for intermediate heat exchange from NGNP. For process heat it is desired that, intermediate heat exchangers (IHX) transfer heat from the NGNP in the most efficient way possible. The production of electric power at higher efficiency via the Brayton Cycle, and hydrogen production, requires both heat at higher temperatures and high effectiveness compact heat exchangers to transfer heat to either the power or process cycle. Compact heat exchangers maximize the heat transfer surface area per volume of heat exchanger; this has the benefit of reducing heat exchanger size and heat losses. High temperature IHX design requirements are governed in part by the allowable temperature drop between the outlet and inlet of the NGNP. In order to improve the characteristics of heat transfer, liquid metal phase change heat exchangers may be more effective and efficient. This paper explores the overall heat transfer characteristics and pressure drop of the phase change heat exchanger with Na as the heat exchanger coolant. In order to design a very efficient and effective heat exchanger one must optimize the design such that we have a high heat transfer and a lower pressure drop, but there is always a trade-off between them. Based on NGNP operational parameters, a heat exchanger analysis with the sodium phase change will be presented to show that the heat exchanger has the potential for highly effective heat transfer, within a small volume at reasonable cost.

  17. Heat exchanger for power generation equipment

    DOE Patents [OSTI]

    Nirmalan, Nirm Velumylm; Bowman, Michael John

    2005-06-14T23:59:59.000Z

    A heat exchanger for a turbine is provided wherein the heat exchanger comprises a heat transfer cell comprising a sheet of material having two opposed ends and two opposed sides. In addition, a plurality of concavities are disposed on a surface portion of the sheet of material so as to cause hydrodynamic interactions and affect a heat transfer rate of the turbine between a fluid and the concavities when the fluid is disposed over the concavities.

  18. Thermodynamic Efficiency of Heat Exchange Devices

    E-Print Network [OSTI]

    Witte, L. C.; Shamsundar, N.

    1982-01-01T23:59:59.000Z

    is defined for heat exchange devices. The efficiency can be simply written in terms of the mean absolute temperature levels of the two fluids exchanging heat, and an appropriate environment temperature. It is also shown that for a given ratio of hot to cold...

  19. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P. (San Ramon, CA)

    2012-07-24T23:59:59.000Z

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  20. Heat exchanger device and method for heat removal or transfer

    DOE Patents [OSTI]

    Koplow, Jeffrey P

    2013-12-10T23:59:59.000Z

    Systems and methods for a forced-convection heat exchanger are provided. In one embodiment, heat is transferred to or from a thermal load in thermal contact with a heat conducting structure, across a narrow air gap, to a rotating heat transfer structure immersed in a surrounding medium such as air.

  1. Heat exchanger with transpired, highly porous fins

    DOE Patents [OSTI]

    Kutscher, Charles F. (Golden, CO); Gawlik, Keith (Boulder, CO)

    2002-01-01T23:59:59.000Z

    The heat exchanger includes a fin and tube assembly with increased heat transfer surface area positioned within a hollow chamber of a housing to provide effective heat transfer between a gas flowing within the hollow chamber and a fluid flowing in the fin and tube assembly. A fan is included to force a gas, such as air, to flow through the hollow chamber and through the fin and tube assembly. The fin and tube assembly comprises fluid conduits to direct the fluid through the heat exchanger, to prevent mixing with the gas, and to provide a heat transfer surface or pathway between the fluid and the gas. A heat transfer element is provided in the fin and tube assembly to provide extended heat transfer surfaces for the fluid conduits. The heat transfer element is corrugated to form fins between alternating ridges and grooves that define flow channels for directing the gas flow. The fins are fabricated from a thin, heat conductive material containing numerous orifices or pores for transpiring the gas out of the flow channel. The grooves are closed or only partially open so that all or substantially all of the gas is transpired through the fins so that heat is exchanged on the front and back surfaces of the fins and also within the interior of the orifices, thereby significantly increasing the available the heat transfer surface of the heat exchanger. The transpired fins also increase heat transfer effectiveness of the heat exchanger by increasing the heat transfer coefficient by disrupting boundary layer development on the fins and by establishing other beneficial gas flow patterns, all at desirable pressure drops.

  2. Integrated Approach to Revamping Heat Exchangers Networks

    E-Print Network [OSTI]

    Glass, K. E.; Dhole, V.; Wang, Y.

    geometry configurations for a given set of process conditions. Develop simulation model (in Aspen Plus) incorporating rigorous heat exchanger (Aspen Hetran) models for the 1) Validate existing preheat train performance & evaluate the existing and de...-bottlenecked cases de-bottlenecked performance Initiate pinch analysis (using Aspen Pinch) directly 2) Determine feasible energy saving from (Aspen Plus) simulation results Heat exchanger network pinch analysis (using Aspen Pinch) incorporating rigorous (Aspen...

  3. Heat Exchanger Technologies for Distillation Columns

    E-Print Network [OSTI]

    Polley, G. T.

    each type of exchanger in turn. Heat exchanger size is minimised if the temperature driving force is maximised. The design should therefore seek to minimise the temperature changes during phase change. So, streams that are being condensed are kept... Reboiler not always possible (e.g. one part of a unit may be running at reduced load). Result: installed steam driven unit required to ensure integrity or heat recovery not used. Low temperature driving force Operation at low temperature driving force...

  4. Laminar Flow Forced Convection Heat Transfer Behavior of Phase Change Material Fluid in Straight and Staggered Pin Microchannels

    E-Print Network [OSTI]

    Kondle, Satyanarayana

    2011-10-21T23:59:59.000Z

    ? Density Subscripts b Bulk i Inlet w Wall 1 Start of melting 2 End of melting Superscripts `` Flux - Average Acronyms CHF Constant heat glux CWT Constant wall temperature PCM Phase change material ix TABLE...:8 microchannel under T boundary condition .............. 52 Figure 32 Nusselt number for square pins geometry using CHF boundary condition ... 55 Figure 33 Nusselt number for circular pins geometry using CHF boundary condition . 55 Figure 34 Fluid...

  5. IntroductiontoProcessEngineering(PTG) 4. Heat exchangers;

    E-Print Network [OSTI]

    Zevenhoven, Ron

    ProcessEngineering(PTG) VST rz13 8/72 Heat exchangers: energy balance Picture: SEHB06 Heat exchanger schematic with open/72 Overall heat transfer coefficient · The heat transfer process* may be described by a simple model expression Q = U·A·T for temperature diffence T (°C), heat exchange area A (m2) and overall heat transfer

  6. MODELING PARTICLE DEPOSITION ON HVAC HEAT EXCHANGERS

    E-Print Network [OSTI]

    LBNL-49339 MODELING PARTICLE DEPOSITION ON HVAC HEAT EXCHANGERS J.A. Siegel1,3 * and W.W. Nazaroff2 Department of Energy under contract DE-AC03-76SF00098. #12;MODELING PARTICLE DEPOSITION ON HVAC HEAT, such as discontinuities in the fins, are hypothesized to be responsible for the discrepancy. INDEX TERMS HVAC, Fouling

  7. Heat Exchanger With Internal Pin Elements

    DOE Patents [OSTI]

    Gerstmann, Joseph (Framingham, MA); Hannon, Charles L. (Arlington, MA)

    2004-01-13T23:59:59.000Z

    A heat exchanger/heater comprising a tubular member having a fluid inlet end, a fluid outlet end and plurality of pins secured to the interior wall of the tube. Various embodiments additionally comprise a blocking member disposed concentrically inside the pins, such as a core plug or a baffle array. Also disclosed is a vapor generator employing an internally pinned tube, and a fluid-heater/heat-exchanger utilizing an outer jacket tube and fluid-side baffle elements, as well as methods for heating a fluid using an internally pinned tube.

  8. Simulation of three-dimensional laminar flow and heat transfer in an array of parallel microchannels

    E-Print Network [OSTI]

    Mlcak, Justin Dale

    2009-05-15T23:59:59.000Z

    and incorrect reporting of experimental uncertainty. Agostini et al. [16] detailed the importance of obtaining a very low uncertainty when measuring the dimensions of mini and microchannels. An example illustrated that a 3% uncertainty on channel width...

  9. Demonstration and Performance Monitoring of Foundation Heat Exchangers...

    Energy Savers [EERE]

    for New and Existing Homes: Foundation Heat Exchanger, Oak Ridge, Tennessee Performance Analysis of Air-Source Variable Speed Heat Pumps and Various Electric Water Heating Options...

  10. Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger

    E-Print Network [OSTI]

    Singh, K. P.

    1979-01-01T23:59:59.000Z

    The concept of a "Divided-flow" heat exchanger is generalized by locating the shell inlet (or outlet) nozzle off-center such that the two shell sub-streams are unequal and traverse unequal flow paths. The governing equations for heat transfer...

  11. Heat exchanger for coal gasification process

    DOE Patents [OSTI]

    Blasiole, George A. (Greensburg, PA)

    1984-06-19T23:59:59.000Z

    This invention provides a heat exchanger, particularly useful for systems requiring cooling of hot particulate solids, such as the separated fines from the product gas of a carbonaceous material gasification system. The invention allows effective cooling of a hot particulate in a particle stream (made up of hot particulate and a gas), using gravity as the motive source of the hot particulate. In a preferred form, the invention substitutes a tube structure for the single wall tube of a heat exchanger. The tube structure comprises a tube with a core disposed within, forming a cavity between the tube and the core, and vanes in the cavity which form a flow path through which the hot particulate falls. The outside of the tube is in contact with the cooling fluid of the heat exchanger.

  12. Modeling particle deposition on HVAC heat exchangers

    SciTech Connect (OSTI)

    Siegel, J.A.; Nazaroff, W.W.

    2002-01-01T23:59:59.000Z

    Fouling of fin-and-tube heat exchangers by particle deposition leads to diminished effectiveness in supplying ventilation and air conditioning. This paper explores mechanisms that cause particle deposition on heat exchanger surfaces. We present a model that accounts for impaction, diffusion, gravitational settling, and turbulence. Simulation results suggest that some submicron particles deposit in the heat exchanger core, but do not cause significant performance impacts. Particles between 1 and 10 {micro}m deposit with probabilities ranging from 1-20% with fin edge impaction representing the dominant mechanism. Particles larger than 10 {micro}m deposit by impaction on refrigerant tubes, gravitational settling on fin corrugations, and mechanisms associated with turbulent airflow. The model results agree reasonably well with experimental data, but the deposition of larger particles at high velocities is underpredicted. Geometric factors, such as discontinuities in the fins, are hypothesized to be responsible for the discrepancy.

  13. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, David Gordon (Winchester, MA)

    2002-01-01T23:59:59.000Z

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  14. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, David Gordon

    2001-04-17T23:59:59.000Z

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices.

  15. Heat exchanger containing a component capable of discontinuous movement

    DOE Patents [OSTI]

    Wilson, D.G.

    1993-11-09T23:59:59.000Z

    Regenerative heat exchangers are described for transferring heat between hot and cold fluids. The heat exchangers have seal-leakage rates significantly less than those of conventional regenerative heat exchangers because the matrix is discontinuously moved and is releasably sealed while in a stationary position. Both rotary and modular heat exchangers are described. Also described are methods for transferring heat between a hot and cold fluid using the discontinuous movement of matrices. 11 figures.

  16. Multidimensional numerical modeling of heat exchangers. [LMFBR

    SciTech Connect (OSTI)

    Sha, W.T.; Yang, C.I.; Kao, T.T.; Cho, S.M.

    1982-01-01T23:59:59.000Z

    A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchangers for liquid-metal services. For the shellside fluid, the conservation equations of mass, momentum, and energy for continuum fluids are modified using the concept of porosity, surface permeability and distributed resistance to account for the blockage effects due to the presence of heat-transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, the heat-transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phase on the shell side and may undergo phase-change on the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reactor (LMFBR) intermediate heat exchangers (IHX) and steam generators (SG).

  17. Foundation Heat Exchanger Model and Design Tool Development and Validation

    E-Print Network [OSTI]

    Heat Exchangers for Residential Ground Source Heat Pump Systems - Numerical Modeling and Experimental. Fisher, J. Shonder, P. Im. 2010. Residential Ground Source Heat Pump Systems Utilizing Foundation Heat. Feasibility of foundation heat exchangers in ground source heat pump systems in the United States. ASHRAE

  18. Modeling of Heat Transfer in Geothermal Heat Exchangers

    E-Print Network [OSTI]

    Cui, P.; Man, Y.; Fang, Z.

    2006-01-01T23:59:59.000Z

    , University of Lund, Sweden, [7] Fang, Z., Diao, N., and Cui, P., Discontinuous operation of geothermal heat exchangers [J], Tsinghua Science and Technology. , 2002, 7 194?197. [8] Hellstrom, G., Ground heat storage -- Thermal analysis of duct storage... systems [D], Department of Mathem Sweden, 1991. [9] Mei, V. C. and Baxter, V. D., Performance of a ground-coupled heat pump with multiple dissimilar U-tu Transactions, 1986, 92 Part 2, 22-25. [10] Yavuzturk, C., Spitler, J. D. and Rees, S. J., A...

  19. Fouling of HVAC fin and tube heat exchangers

    E-Print Network [OSTI]

    Siegel, Jeffrey; Carey, Van P.

    2001-01-01T23:59:59.000Z

    air ? air ? part ? part FPI HVAC REFERENCES Anonymous, 1987,LBNL-47668 Fouling of HVAC Fin and Tube Heat ExchangersCIEE SPONSOR. FOULING OF HVAC FIN AND TUBE HEAT EXCHANGERS

  20. Using Plate Heat Exchangers to Increase Energy Efficiency

    E-Print Network [OSTI]

    Bailey, K.

    "In recent years, there has been an increasing awareness of Plate Heat Exchangers (PHE's) in industrial processes around the world. While PHE's have historically been classified as compact heat exchangers, compactness is often a secondary advantage...

  1. High-Performance Refrigerator Using Novel Rotating Heat Exchanger...

    Broader source: Energy.gov (indexed) [DOE]

    pumps have the potentially to reduce energy costs and refrigerant charge in a compact space. Rotating heat exchangers installed in appliances and heat pumps have the potentially...

  2. alloy heat exchanger: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Heat Exchangers, Heat Transfer, Energy, Phase Change and multiphase process, Renewable energy (Solan, Tidal), Energy Storage, Conversion Cessi, Paola 53 Dealing with...

  3. Dealing with Uncertainties During Heat Exchanger Design

    E-Print Network [OSTI]

    Polley, G. T.; Pugh, S. J.

    Technology Conference, Houston, TX, May 1-4, 2001 E2 Area = 100 m 2 cp= 35 kW/K El Area = 300 m 2 Figure 1. Simple Heat Exchanger Network CP = 30 kW/K CP= 55 kWIK Assume that exchangers EI (of heat transfer area 100 m 2 ) and E2 (of 300 m 2... .) are perfectly sized. Consequently, the cold stream leaving E I has a temperature of 277?C and that leaving E2 a temperature of 212?C. If a ten percent design margin had been added to each of these units (i.e. El now has 110 m 2 and E2 has 330 m 2...

  4. Heat exchanger support apparatus in a fluidized bed

    DOE Patents [OSTI]

    Lawton, Carl W. (West Hartford, CT)

    1982-01-01T23:59:59.000Z

    A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

  5. Design of a microbreather for two-phase microchannel devices

    E-Print Network [OSTI]

    Alexander, Brentan R

    2008-01-01T23:59:59.000Z

    Multiphase flows in microchannels are encountered in a variety of microfluidic applications. Two-phase microchannel heat sinks leverage the latent heat of vaporization to offer an efficient method of dissipating large heat ...

  6. Heat Pump Cycle with Solution Circuit and Internal Heat Exchange

    E-Print Network [OSTI]

    Radermacher, R.

    -stage cycle, the heat transfer area required on the refrigerant side will increase by 10~ compared to the ammonia cycl e. CONCLUSIONS The hea t p1llllp cycl e employ ing one sol ut ion circuit and absorber/de sorber heat exchange has a more sophisticated... when a two-stage version fed into the same compressor. While ammonia of this cycl e is used. In this paper. another evaporate s out of an ammonia-water sol ution on C version of such cycles will be discussed which the composition. X. of this solution...

  7. Design and Development of a Plastic Film Heat Exchanger

    E-Print Network [OSTI]

    Guyer, E. C.; Gollin, M. K.; Brownell, D. L.

    of the PFHX technology in olving heat. exchange at any pressure other than'atmo pheric pressure. Atmospheric applications could ope ate with a simple remote level control basin. There are also many other potential appl ca tions of the PFHX technology...DESIGN AND DEVELOPMENT OF A PLASTIC FILM HEAT EXCHANGER Eric C. Guyer, Sc.D., David L. Brownell, and Martin K. Gollin Dynatech RID Company Cambridge, Massachusetts ABSTRACT A plastic film heat exchang.er (PFHX) utilizes the low cost...

  8. DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM

    SciTech Connect (OSTI)

    G. K. Housley; J.E. O'Brien; G.L. Hawkes

    2008-11-01T23:59:59.000Z

    Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.

  9. Condensation in horizontal heat exchanger tubes

    SciTech Connect (OSTI)

    Leyer, S.; Zacharias, T.; Maisberger, F.; Lamm, M. [AREVA NP GmbH, Paul-Gossen-Strasse 100, Erlangen, 91052 (Germany); Vallee, C.; Beyer, M.; Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstrasse 400, Dresden, 01328 (Germany)

    2012-07-01T23:59:59.000Z

    Many innovative reactor concepts for Generation III nuclear power plants use passive safety equipment for residual heat removal. These systems use two phase natural circulation. Heat transfer to the coolant results in a density difference providing the driving head for the required mass flow. By balancing the pressure drop the system finds its operational mode. Therefore the systems depend on a strong link between heat transfer and pressure drop determining the mass flow through the system. In order to be able to analyze these kind of systems with the help of state of the art computer codes the implemented numerical models for heat transfer, pressure drop or two phase flow structure must be able to predict the system performance in a wide parameter range. Goal of the program is to optimize the numerical models and therefore the performance of computer codes analyzing passive systems. Within the project the heat transfer capacity of a heat exchanger tube will be investigated. Therefore the tube will be equipped with detectors, both temperature and pressure, in several directions perpendicular to the tube axis to be able to resolve the angular heat transfer. In parallel the flow structure of a two phase flow inside and along the tube will be detected with the help of x-ray tomography. The water cooling outside of the tube will be realized by forced convection. It will be possible to combine the flow structure measurement with an angular resolved heat transfer for a wide parameter range. The test rig is set up at the TOPLFOW facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), so that it will be possible to vary the pressure between 5 and 70 bar. The steam mass content will be varied between 0 and 100 percent. The results will be compared to the large scaled Emergency Condenser Tests performed at the INKA test facility in Karlstein (Germany). The paper will explain the test setup and the status of the project will be presented. (authors)

  10. A simplified methodology for sizing ground coupled heat pump heat exchangers in cooling dominated climates

    E-Print Network [OSTI]

    Gonzalez, Jose Antonio

    1993-01-01T23:59:59.000Z

    between GSIM and two commercially available heat exchanger sizing methods, the National Water Well Association (NWWA) and the International Ground Source Heat Pump Association (IGSHPA) methods, was performed. GSIM heat exchanger lengths for Dallas were... Pump Capacity and Cooling Load. . . . . Oversizing and Undersizing the Heat Pump. . . . . . . . . . . . . . Summary. . 72 74 76 78 80 82 85 87 90 92 IX COMPARISON OF HEAT EXCHANGER SIZING METHODS . . 93 International Ground Source Heat...

  11. CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER

    E-Print Network [OSTI]

    Kandlikar, Satish

    1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation schemes proposed by Yan and Lin (1999b) for modeling the heat transfer coefficient in both a single- phase

  12. Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01T23:59:59.000Z

    This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it has an optimal frequency...

  13. Temperature profile of the infrared image Heat exchange between

    E-Print Network [OSTI]

    Jaehne, Bernd

    T Temperature profile of the infrared image Heat exchange between atmosphere and ocean References coefficient of heat in water determine the heat transfer velocity: *t Infrared images of the water surface: a-Karls-Universität Heidelberg www.uni-heidelberg.de Active controlled flux technique (ACFT) Continuous heat flux Periodic heat

  14. Heat exchanger for fuel cell power plant reformer

    DOE Patents [OSTI]

    Misage, Robert (Manchester, CT); Scheffler, Glenn W. (Tolland, CT); Setzer, Herbert J. (Ellington, CT); Margiott, Paul R. (Manchester, CT); Parenti, Jr., Edmund K. (Manchester, CT)

    1988-01-01T23:59:59.000Z

    A heat exchanger uses the heat from processed fuel gas from a reformer for a fuel cell to superheat steam, to preheat raw fuel prior to entering the reformer and to heat a water-steam coolant mixture from the fuel cells. The processed fuel gas temperature is thus lowered to a level useful in the fuel cell reaction. The four temperature adjustments are accomplished in a single heat exchanger with only three heat transfer cores. The heat exchanger is preheated by circulating coolant and purge steam from the power section during startup of the latter.

  15. Control Dewar Subcooler Heat Exchanger Calculations

    SciTech Connect (OSTI)

    Rucinski, R.; /Fermilab

    1993-10-04T23:59:59.000Z

    The calculations done to size the control dewar subcooler were done to obtain a sufficient subcooler size based on some conservative assumptions. The final subcooler design proposed in the design report will work even better because (1) It has more tubing length, and (2) will have already subcooled liquid at the inlet due to the transfer line design. The subcooler design described in the 'Design Report of the 2 Tesla Superconducting Solenoid for the Fermilab D0 Detector Upgrade' is the final design proposed. A short description of this design follows. The subcooler is constructed of 0.50-inch OD copper tubing with 1.0-inch diameter fins. It has ten and one half spirals at a 11.375-inch centerline diameter to provide 31 feet of tubing length. The liquid helium supply for the solenoid flows through the subcooler and then is expanded through a J-T valve. The subcooler spirals are immersed in the return two phase helium process stream. The return stream is directed over the finned tubing by an annulus created by a 10-inch pipe inside a 12-inch pipe. The transfer line from the refrigerator to the control dewar is constructed such that the liquid helium supply tube is in the refrigerator return stream, thereby subcooling the liquid up to the point where the u-tubes connect the transfer line to the control dewar. The subcooler within the control dewar will remove the heat picked up in the helium supply u-tube/bayonets. The attached subcooler/heat exchanger calculations were done neglecting any subcooling in the transfer line. All heat picked up in the transfer line from the refrigerator storage dewar to the control dewar is absorbed by the supply stream. The subcooler was sized such that the two phase supply fluid is subcooled at 1.7 atm pressure and when expanded through a JT valve to 1.45 atm pressure it is at a saturated liquid state. The calculations apply during steady state operation and at a flow rate of 16 g/s. The analysis of the heat exchanger was broken into two parts relating to the heat transfer mode taking place. The first part is considered the condensing part in which the helium supply stream is changed from two phase fluid to one phase liquid. The second part is the subcooling part where the liquid temperature is lowered, i.e.. subcooled. A summary of the calculations and results appears on the next page. The raw calculations follow the summary.

  16. Heat extraction from salinity-gradient solar ponds using heat pipe heat exchangers

    SciTech Connect (OSTI)

    Tundee, Sura; Terdtoon, Pradit; Sakulchangsatjatai, Phrut [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand); Singh, Randeep; Akbarzadeh, Aliakbar [Energy Conservation and Renewable Energy Group, School of Aerospace, Mechanical and Manufacturing Engineering, RMIT University, Bundoora East Campus, Bundoora, Victoria 3083 (Australia)

    2010-09-15T23:59:59.000Z

    This paper presents the results of experimental and theoretical analysis on the heat extraction process from solar pond by using the heat pipe heat exchanger. In order to conduct research work, a small scale experimental solar pond with an area of 7.0 m{sup 2} and a depth of 1.5 m was built at Khon Kaen in North-Eastern Thailand (16 27'N102 E). Heat was successfully extracted from the lower convective zone (LCZ) of the solar pond by using a heat pipe heat exchanger made from 60 copper tubes with 21 mm inside diameter and 22 mm outside diameter. The length of the evaporator and condenser section was 800 mm and 200 mm respectively. R134a was used as the heat transfer fluid in the experiment. The theoretical model was formulated for the solar pond heat extraction on the basis of the energy conservation equations and by using the solar radiation data for the above location. Numerical methods were used to solve the modeling equations. In the analysis, the performance of heat exchanger is investigated by varying the velocity of inlet air used to extract heat from the condenser end of the heat pipe heat exchanger (HPHE). Air velocity was found to have a significant influence on the effectiveness of heat pipe heat exchanger. In the present investigation, there was an increase in effectiveness by 43% as the air velocity was decreased from 5 m/s to 1 m/s. The results obtained from the theoretical model showed good agreement with the experimental data. (author)

  17. Automatic Tube Cleaning Systems for Condensers and Heat Exchangers

    E-Print Network [OSTI]

    Someah, K.

    AUTOMATIC TUBE CLEANING SYSTEMS FOR CONDENSERS AND HEAT EXCHANGERS Kaveh Someah/V.P. Sales & Mktg. WSA Engineered Systems, Milwaukee, WI (414) 354-6470 ABSTRACT The on-line Automatic Tube Cleaning Systems (ATCS) for condensers and heat... exchangers provide a positive means for automatic cleaning on a continuous basis, while the exchanger or condenser remains "on stream" and at its full operating potential. Condenser tube fouling contributes up to 50% of the total condenser tube heat...

  18. Design and Test of Tube & Shell Heat Exchangers for Potential

    E-Print Network [OSTI]

    exchangerLow-temperature side Chiller > Calorimeter body Storage tank Storage tank Calorimeter monitor Calorimeter body High-temperature side Chiller > Experimental apparatus for seawater heat

  19. Heat transfer in the plate heat exchanger of an ammonia-synthesis column

    SciTech Connect (OSTI)

    Obolentsev, Y.G.; Chus', M.S.; Norobchanskii, O.A.; Teplitshi, Y.S.; Tovazhnyanskii, L.L.

    1983-01-01T23:59:59.000Z

    The planning and construction of high-capacity synthetic ammonia plants requires the development and fabrication of unique, high unit-power equipment with high technical and economic characteristics. In foreign and domestic practice, tubular heat exchangers with relatively low heat-transfer coefficients are used. Plate heat exchangers are a promising alternative. They are compact and have a high heat energy efficiency and a relatively small metal content. To make an experimental check of the operating capability of a plate heat exchanger under ammonia production conditions, a welded plate heat exchanger was designed for an ammonia synthesis column 800mm in diameter. On prolonged testing (four years), the device provided an autothermal operating mode in the column and the heat transfer coefficient was practically constant for fixed space velocities. Consequently, the heat exchange surface was not contaminated significantly with catalyst dust, confirmed by visual observation of the heat exchanger after disassembly.

  20. Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers

    E-Print Network [OSTI]

    Thole, Karen A.

    Effects of winglets to augment tube wall heat transfer in louvered fin heat exchangers Paul A transfer along the tube wall of the compact heat exchanger through the use of winglets placed of attack, aspect ratio, direction, and shape, were all evaluated based on heat transfer augmentation

  1. MODELING OF VERTICAL GROUND LOOP HEAT EXCHANGERS FOR GROUND SOURCE

    E-Print Network [OSTI]

    MODELING OF VERTICAL GROUND LOOP HEAT EXCHANGERS FOR GROUND SOURCE HEAT PUMP SYSTEMS By CENK SOURCE HEAT PUMP SYSTEMS Thesis Approved: ___________________________________________ Thesis Adviser scale test data. The short-term behavior of ground-coupled heat pump systems is important for the design

  2. Deposition of Biological Aerosols on HVAC Heat Exchangers

    E-Print Network [OSTI]

    LBNL-47669 Deposition of Biological Aerosols on HVAC Heat Exchangers Jeffrey Siegel and Iain Walker of Biological Aerosols on HVAC Heat Exchangers Jeffrey A. Siegel Iain S. Walker, Ph.D. ASHRAE Student Member that are found in commercial and residential HVAC systems of 1 - 6 m/s (200 - 1200 ft/min), particle diameters

  3. Experimental Investigation of Forced Convection Heat Transfer of Nanofluids in a Microchannel using Temperature Nanosensors

    E-Print Network [OSTI]

    Yu, Jiwon 1982-

    2012-12-03T23:59:59.000Z

    for performing the experimental measurements. TFT arrays were designed (which included design of photomask layout), microfabricated, packaged and assembled for testing with the experimental apparatus. Heat removal rates from the heated surface to the different...

  4. Experimental and numerical study of pressure drop and heat transfer in a single-phase micro-channel heat sink

    E-Print Network [OSTI]

    Qu, Weilin

    Experimental and numerical study of pressure drop and heat transfer in a single-phase micro Received 6 July 2001; received in revised form 26 October 2001 Abstract The pressure drop and heat transfer-dimensional heat transfer characteristics of the heat sink were analyzed numerically by solving the conjugate heat

  5. Demonstration of Energy Efficient Steam Reforming in Microchannels for Automotive Fuel Processing

    SciTech Connect (OSTI)

    Whyatt, Greg A.; TeGrotenhuis, Ward E.; Geeting, John GH; Davis, James M.; Wegeng, Robert S.; Pederson, Larry R.

    2002-01-01T23:59:59.000Z

    A compact, energy efficient microchannel steam reforming system has been demonstrated. The unit generates sufficient reformate to provide H2 to a 10 kWe PEM fuel cell (when coupled with a water-gas shift and CO cleanup reactors). The overall volume of the reactor is 4.9 liters while that of the supporting network of heat exchangers is 1.7 liters . Use of a microchannel configuration in the steam reforming reactor produces rapid heat and mass transport which enables fast kinetics for the highly endothermic reaction. Heat is provided to the reactor by a combustion gas flowing in interleaved microchannels in cross flow with the reaction channels. A network of microchannel heat exchangers allows recovery of heat in the reformate product and combustion exhaust streams for use in vaporizing water and fuel, preheating reactants to reactor temperature and preheating combustion air. The microchannel architecture enables very compact and highly effective heat exchangers to be constructed. As a result of the heat exchange network, the system exhaust temperatures are typically ~50?C for the combustion gas and ~130?C for the reformate product while the reactor is operated at 750?C. While reforming isooctane at a rate sufficient to supply a 13.7 kWe fuel cell the system achieved 98.6% conversion with an estimated overall system efficiency after integration with WGS and PEM fuel cell of 44% (electrical output / LHV fuel). The efficiency estimate assumes integration with a WGS reactor (90% conversion CO to CO2 with 100% selectivity) and a PEM fuel cell (64% power conversion effectiveness with 85% H2 utilization for an overall 54% efficiency) and does not include parasitic losses for compression of combustion air. Acknowledgement The work described here was funded by the U.S. Department of Energy, Office of Transportation Technology as part of the OTT Fuel Cells Program.

  6. Direct-contact closed-loop heat exchanger

    DOE Patents [OSTI]

    Berry, Gregory F. (Naperville, IL); Minkov, Vladimir (Skokie, IL); Petrick, Michael (Joliet, IL)

    1984-01-01T23:59:59.000Z

    A high temperature heat exchanger with a closed loop and a heat transfer liquid within the loop, the closed loop having a first horizontal channel with inlet and outlet means for providing direct contact of a first fluid at a first temperature with the heat transfer liquid, a second horizontal channel with inlet and outlet means for providing direct contact of a second fluid at a second temperature with the heat transfer liquid, and means for circulating the heat transfer liquid.

  7. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI); Marsala, Joseph (Glen Ellyn, IL)

    1994-11-29T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  8. Error Analysis of Heat Transfer for Finned-Tube Heat-Exchanger Text-Board

    E-Print Network [OSTI]

    Chen, Y.; Zhang, J.

    2006-01-01T23:59:59.000Z

    In order to reduce the measurement error of heat transfer in water and air side for finned-tube heat-exchanger as little as possible, and design a heat-exchanger test-board measurement system economically, based on the principle of test-board system...

  9. Compact heat exchangers for condensation applications: Yesterday, today and tomorrow

    SciTech Connect (OSTI)

    Panchal, C.B.

    1993-07-01T23:59:59.000Z

    Compact heat exchangers are being increasingly considered for condensation applications in the process, cryogenic, aerospace, power and refrigeration industries. In this paper, different configurations available for condensation applications are analyzed and the current state-of-the-knowledge for the design of compact condensers is evaluated. The key technical issues for the design and development of compact heat exchangers for condensation applications are analyzed and major advantages are identified. The experimental data and performance prediction methods reported in the literature are analyzed to evaluate the present design capabilities for different compact heat-exchanger configurations. The design flexibility is evaluated for the development of new condensation applications, including integration with other process equipment.

  10. Heat exchanger and water tank arrangement for passive cooling system

    DOE Patents [OSTI]

    Gillett, J.E.; Johnson, F.T.; Orr, R.S.; Schulz, T.L.

    1993-11-30T23:59:59.000Z

    A water storage tank in the coolant water loop of a nuclear reactor contains a tubular heat exchanger. The heat exchanger has tube sheets mounted to the tank connections so that the tube sheets and tubes may be readily inspected and repaired. Preferably, the tubes extend from the tube sheets on a square pitch and then on a rectangular pitch there between. Also, the heat exchanger is supported by a frame so that the tank wall is not required to support all of its weight. 6 figures.

  11. Acoustically enhanced heat exchange and drying apparatus

    DOE Patents [OSTI]

    Bramlette, T.T.; Keller, J.O.

    1987-07-10T23:59:59.000Z

    A heat transfer drying apparatus includes an acoustically augmented heat transfer chamber for receiving material to be dried. The chamber includes a first heat transfer gas inlet, a second heat transfer gas inlet, a material inlet, and a gas outlet which also serves as a dried material and gas outlet. A non-pulsing first heat transfer gas source provides a first drying gas to the acoustically augmented heat transfer chamber through the first heat transfer gas inlet. A valveless, continuous second heat transfer gas source provides a second drying gas to the acoustically augmented heat transfer chamber through the second heat transfer gas inlet. The second drying gas also generates acoustic waves which bring about acoustical coupling with the gases in the acoustically augmented heat transfer chamber. The second drying gas itself oscillates at an acoustic frequency of approximately 180 Hz due to fluid mechanical motion in the gas. The oscillations of the second heat transfer gas coupled to the first heat transfer gas in the acoustically augmented heat transfer chamber enhance heat and mass transfer by convection within the chamber. 3 figs.

  12. SILICON CARBIDE CERAMICS FOR COMPACT HEAT EXCHANGERS

    SciTech Connect (OSTI)

    DR. DENNIS NAGLE; DR. DAJIE ZHANG

    2009-03-26T23:59:59.000Z

    Silicon carbide (SiC) materials are prime candidates for high temperature heat exchangers for next generation nuclear reactors due to their refractory nature and high thermal conductivity at elevated temperatures. This research has focused on demonstrating the potential of liquid silicon infiltration (LSI) for making SiC to achieve this goal. The major advantage of this method over other ceramic processing techniques is the enhanced capability of making high dense, high purity SiC materials in complex net shapes. For successful formation of net shape SiC using LSI techniques, the carbon preform reactivity and pore structure must be controlled to allow the complete infiltration of the porous carbon structure which allows complete conversion of the carbon to SiC. We have established a procedure for achieving desirable carbon properties by using carbon precursors consisting of two readily available high purity organic materials, crystalline cellulose and phenolic resin. Phenolic resin yields a glassy carbon with low chemical reactivity and porosity while the cellulose carbon is highly reactive and porous. By adjusting the ratio of these two materials in the precursor mixtures, the properties of the carbons produced can be controlled. We have identified the most favorable carbon precursor composition to be a cellulose resin mass ratio of 6:4 for LSI formation of SiC. The optimum reaction conditions are a temperature of 1800 C, a pressure of 0.5 Torr of argon, and a time of 120 minutes. The fully dense net shape SiC material produced has a density of 2.96 g cm{sup -3} (about 92% of pure SiC) and a SiC volume fraction of over 0.82. Kinetics of the LSI SiC formation process was studied by optical microscopy and quantitative digital image analysis. This study identified six reaction stages and provided important understanding of the process. Although the thermal conductivity of pure SiC at elevated temperatures is very high, thermal conductivities of most commercial SiC materials are much lower due to phonon scattering by impurities (e.g., sintering aids located at the grain boundaries of these materials). The thermal conductivity of our SiC was determined using the laser flash method and it is 214 W/mK at 373 K and 64 W/mK at 1273 K. These values are very close to those of pure SiC and are much higher than those of SiC materials made by industrial processes. This SiC made by our LSI process meets the thermal properties required for use in high temperature heat exchanger. Cellulose and phenolic resin carbons lack the well-defined atomic structures associated with common carbon allotropes. Atomic-scale structure was studied using high resolution transmission electron microscopy (HRTEM), nitrogen gas adsorption and helium gas pycnometry. These studies revealed that cellulose carbon exhibits a very high degree of atomic disorder and angstrom-scale porosity. It has a density of only 93% of that of pure graphite, with primarily sp2 bonding character and a low concentration of graphene clusters. Phenolic resin carbon shows more structural order and substantially less angstrom-scale porosity. Its density is 98% of that of pure graphite, and Fourier transform analysis of its TEM micrographs has revealed high concentrations of sp3 diamond and sp2 graphene nano-clusters. This is the first time that diamond nano-clusters have been observed in carbons produced from phenolic resin. AC and DC electrical measurements were made to follow the thermal conversion of microcrystalline cellulose to carbon. This study identifies five regions of electrical conductivity that can be directly correlated to the chemical decomposition and microstructural evolution during carbonization. In Region I, a decrease in overall AC conductivity occurs due to the initial loss of the polar groups from cellulose molecules. In Region II, the AC conductivity starts to increase with heat treatment temperature due to the formation and growth of conducting carbon clusters. In Region III, a further increase of AC conductivity with increasing heat treatment temperature is obs

  13. Evaluation of fluid bed heat exchanger optimization parameters. Final report

    SciTech Connect (OSTI)

    Not Available

    1980-03-01T23:59:59.000Z

    Uncertainty in the relationship of specific bed material properties to gas-side heat transfer in fluidized beds has inhibited the search for optimum bed materials and has led to over-conservative assumptions in the design of fluid bed heat exchangers. An experimental program was carried out to isolate the effects of particle density, thermal conductivity, and heat capacitance upon fluid bed heat transfer. A total of 31 tests were run with 18 different bed material loads on 12 material types; particle size variations were tested on several material types. The conceptual design of a fluidized bed evaporator unit was completed for a diesel exhaust heat recovery system. The evaporator heat transfer surface area was substantially reduced while the physical dimensions of the unit increased. Despite the overall increase in unit size, the overall cost was reduced. A study of relative economics associated with bed material selection was conducted. For the fluidized bed evaporator, it was found that zircon sand was the best choice among materials tested in this program, and that the selection of bed material substantially influences the overall system costs. The optimized fluid bed heat exchanger has an estimated cost 19% below a fin augmented tubular heat exchanger; 31% below a commercial design fluid bed heat exchanger; and 50% below a conventional plain tube heat exchanger. The comparisons being made for a 9.6 x 10/sup 6/ Btu/h waste heat boiler. The fluidized bed approach potentially has other advantages such as resistance to fouling. It is recommended that a study be conducted to develop a systematic selection of bed materials for fluidized bed heat exchanger applications, based upon findings of the study reported herein.

  14. Process Heat Exchanger Options for the Advanced High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall; Eung Soo Kim; Michael McKellar; Nolan Anderson

    2011-06-01T23:59:59.000Z

    The work reported herein is a significant intermediate step in reaching the final goal of commercial-scale deployment and usage of molten salt as the heat transport medium for process heat applications. The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production and process heat application, which would support large-scale deployment.

  15. Process Heat Exchanger Options for Fluoride Salt High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall; Eung Soo Kim; Michael McKellar; Nolan Anderson

    2011-04-01T23:59:59.000Z

    The work reported herein is a significant intermediate step in reaching the final goal of commercial-scale deployment and usage of molten salt as the heat transport medium for process heat applications. The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production and process heat application, which would support large-scale deployment.

  16. Energy effectiveness of simultaneous heat and mass exchange devices

    E-Print Network [OSTI]

    Narayan, G. Prakash

    2010-01-01T23:59:59.000Z

    Simultaneous heat and mass exchange devices such as cooling towers, humidifiers and dehumidifiers are widely used in the power generation, desalination, air conditioning, and refrigeration industries. For design and rating ...

  17. Heat Transfer of a Multiple Helical Coil Heat Exchanger Using a Microencapsulated Phase Change Material Slurry

    E-Print Network [OSTI]

    Gaskill, Travis

    2012-02-14T23:59:59.000Z

    The present study has focused on the use of coil heat exchangers (CHEs) with microencapsulated phase change material (MPCM) slurries to understand if CHEs can yield greater rates of heat transfer. An experimental study was conducted using a...

  18. A Simplified Procedure for Sizing Vertical Ground Coupled Heat Pump Heat Exchangers for Residences in Texas

    E-Print Network [OSTI]

    O'Neal, D. L.; Gonzalez, J. A.; Aldred, W.

    1994-01-01T23:59:59.000Z

    the simplified method were compared to two available heat exchanger sizing methods: the National Water Well Association (NWWA) and the International Ground Source Heat Pump Association (IGSHPA). The simplified method predicted shorter lengths than those from...

  19. Heat Exchanger Network Targeting, Design and Analysis: The MIDAS Package

    E-Print Network [OSTI]

    Barton, I.; Jones, D. H.; Smith, G. J.

    HEAT EXCHANGER NETWORK TARGETING, DESIGN AND ANALYSIS: THE MIDAS PACKAGE I. BARTON, D.H. JONES AND G.J. SMITH TENSA Services, Houston, Texas ICI PLC, Wilton England ABSTRACT Recent work to consolidate pinch-based procedures for targeting... was reduced to industrial practice by the U.K. major, ICI PLC. A wide range of pinch-based procedures have been developed for process energy efficiency applications. These incl~de heat exchanger network (HEN) design [2,3], distillation system...

  20. Acoustically enhanced heat exchange and drying apparatus

    DOE Patents [OSTI]

    Bramlette, T. Tazwell (Livermore, CA); Keller, Jay O. (Oakland, CA)

    1989-01-01T23:59:59.000Z

    A heat transfer apparatus includes a first chamber having a first heat transfer gas inlet, a second heat transfer gas inlet, and an outlet. A first heat transfer gas source provides a first gas flow to the first chamber through the first heat transfer gas inlet. A second gas flow through a second chamber connected to the side of the first chamber, generates acoustic waves which bring about acoustical coupling of the first and second gases in the acoustically augmented first chamber. The first chamber may also include a material inlet for receiving material to be dried, in which case the gas outlet serves as a dried material and gas outlet.

  1. Heat Exchangers for the Next Generation of Nuclear Reactors

    SciTech Connect (OSTI)

    Xiuqing, Li; Le Pierres, Renaud; Dewson, Stephen John [Heatric Division of Meggitt (UK) Ltd., 46 Holton Road, Holton Heath, Poole, Dorset BH16 6LT (United Kingdom)

    2006-07-01T23:59:59.000Z

    The realisation that fossil fuel resources are finite, the associated rising price and a growing concern about greenhouse gas emissions, has resulted in renewed interest in nuclear energy. Generation IV and other programmes are looking at a variety of new reactors. These reactors vary in type from Very High Temperature Gas Cooled Reactors (VHTR) to Liquid Metal Fast Reactors (LFR and SFR) with cooling mediums that include: - Helium, - Supercritical carbon dioxide, - Sodium, - Lead, - Molten salts. In addition interest is not just focused on production of electrical power with an efficiency greater than that associated with the Rankine Cycle (typically 30 -35%); there is now genuine interest in nuclear energy as a heat source for hydrogen production, via the Sulphur Iodine Process (SI) or high temperature electrolysis. The production of electrical power at higher efficiency via a Brayton Cycle, and hydrogen production requires both heat at higher temperatures, up to 1000 deg C and high effectiveness heat exchange to transfer the heat to either the power or process cycle. This presents new challenges for the heat exchangers. If plant efficiencies are to be improved there is a need for: - High effectiveness heat exchange at minimal pressure drop; - Compact heat exchange to improve safety and economics; - An ability to build coded heat exchangers in a variety of nickel based alloys, oxide dispersion strengthened alloys (ODS) and ceramic materials to address the temperature, life and corrosion issues associated with these demanding duties. Heatric has already given consideration to many of these challenges. Their Print Circuit Heat Exchanger (PCHE) and Formed Plate Heat Exchanger (FPHE) technology which are commercially available today, will fulfill all of the duties up to temperatures of 950 deg C. In addition products currently under development will further increase the temperature and pressure range, while offering greater corrosion resistance and operational life. This paper outlines the challenges for the heat exchangers and the development required, with particular attention given to material selection. It is further the objective of this study to demonstrate that heat exchangers such as PCHE and FPHE are able to meet the above challenges. (authors)

  2. Self-defrosting recuperative air-to-air heat exchanger

    DOE Patents [OSTI]

    Drake, R.L.

    1993-12-28T23:59:59.000Z

    A heat exchanger is described which includes a stationary spirally or concentrically wound heat exchanger core with rotating baffles on upper and lower ends thereof. The rotating baffles include rotating inlets and outlets which are in communication with respective fixed inlets and outlets via annuli. The rotation of the baffles causes a concurrent rotation of the temperature distribution within the stationary exchanger core, thereby preventing frost build-up in some applications and preventing the formation of hot spots in other applications. 3 figures.

  3. Liquid-vapour phase change and multiphase flow heat transfer in single micro-channels using pure liquids and nano-fluids

    E-Print Network [OSTI]

    Wang, Yuan

    2011-11-22T23:59:59.000Z

    Heat management in high thermal-density systems such as CPU chips, nuclear reactors and compact heat exchangers is confronting rising challenges due to ever more miniaturized and intensified processes. While searching ...

  4. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

    Huebotter, P.R.; McLennan, G.A.

    1984-08-30T23:59:59.000Z

    The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

  5. Fast reactor power plant design having heat pipe heat exchanger

    DOE Patents [OSTI]

    Huebotter, Paul R. (Western Springs, IL); McLennan, George A. (Downers Grove, IL)

    1985-01-01T23:59:59.000Z

    The invention relates to a pool-type fission reactor power plant design having a reactor vessel containing a primary coolant (such as liquid sodium), and a steam expansion device powered by a pressurized water/steam coolant system. Heat pipe means are disposed between the primary and water coolants to complete the heat transfer therebetween. The heat pipes are vertically oriented, penetrating the reactor deck and being directly submerged in the primary coolant. A U-tube or line passes through each heat pipe, extended over most of the length of the heat pipe and having its walls spaced from but closely proximate to and generally facing the surrounding walls of the heat pipe. The water/steam coolant loop includes each U-tube and the steam expansion device. A heat transfer medium (such as mercury) fills each of the heat pipes. The thermal energy from the primary coolant is transferred to the water coolant by isothermal evaporation-condensation of the heat transfer medium between the heat pipe and U-tube walls, the heat transfer medium moving within the heat pipe primarily transversely between these walls.

  6. Model based methodology development for energy recovery in flash heat exchange systems

    E-Print Network [OSTI]

    McCarthy, John E.

    Model based methodology development for energy recovery in flash heat exchange systems Problem with a condensing heat exchanger can be used when heat exchange is required between two streams and where at leastH, consistency etc.). To increase the efficiency of heat exchange, a cascade of these units in series can be used

  7. Heat Exchangers for Solar Water Heating Systems | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehicles »Exchange Visitors ProgramEnergyGasDeployment |Exchangers for

  8. Progress Report for Diffusion Welding of the NGNP Process Application Heat Exchangers

    SciTech Connect (OSTI)

    R.E. Mizia; D.E. Clark; M.V. Glazoff; T.E. Lister; T.L. Trowbridge

    2011-04-01T23:59:59.000Z

    The NGNP Project is currently investigating the use of metallic, diffusion welded, compact heat exchangers to transfer heat from the primary (reactor side) heat transport system to the secondary heat transport system. The intermediate heat exchanger will transfer this heat to downstream applications such as hydrogen production, process heat, and electricity generation. The channeled plates that make up the heat transfer surfaces of the intermediate heat exchanger will have to be assembled into an array by diffusion welding.

  9. STUDY OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS

    E-Print Network [OSTI]

    STUDY OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS OF FROST GROWTH ON HEAT EXCHANGERS USED AS OUTDOOR COILS IN AIR SOURCE HEAT PUMP SYSTEMS Dissertation . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 3.5.3 Air Side Heat Transfer Rates . . . . . . . . . . . . . . . . . . 43 3.5.4 Fluid Side Heat

  10. Integrated Module Heat Exchanger | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S.IndianaofPilot Project | DepartmentandModule Heat

  11. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1996-12-03T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  12. Liquid Salt Heat Exchanger Technology for VHTR Based Applications

    SciTech Connect (OSTI)

    Mark Anderson; Kumar Sridhara; Todd Allen; Per Peterson

    2012-10-11T23:59:59.000Z

    The objective of this research is to evaluate performance of liquid salt fluids for use as a heat carrier for transferring high-temperature process heat from the very high-temperature reactor (VHTR) to chemical process plants. Currently, helium is being considered as the heat transfer fluid; however, the tube size requirements and the power associated with pumping helium may not be economical. Recent work on liquid salts has shown tremendous potential to transport high-temperature heat efficiently at low pressures over long distances. This project has two broad objectives: To investigate the compatibility of Incoloy 617 and coated and uncoated SiC ceramic composite with MgCl2-KCl molten salt to determine component lifetimes and aid in the design of heat exchangers and piping; and, To conduct the necessary research on the development of metallic and ceramic heat exchangers, which are needed for both the helium-to-salt side and salt-to-process side, with the goal of making these heat exchangers technologically viable. The research will consist of three separate tasks. The first task deals with material compatibility issues with liquid salt and the development of techniques for on-line measurement of corrosion products, which can be used to measure material loss in heat exchangers. Researchers will examine static corrosion of candidate materials in specific high-temperature heat transfer salt systems and develop an in situ electrochemical probe to measure metallic species concentrations dissolved in the liquid salt. The second task deals with the design of both the intermediate and process side heat exchanger systems. Researchers will optimize heat exchanger design and study issues related to corrosion, fabrication, and thermal stresses using commercial and in-house codes. The third task focuses integral testing of flowing liquid salts in a heat transfer/materials loop to determine potential issues of using the salts and to capture realistic behavior of the salts in a small scale prototype system. This includes investigations of plugging issues, heat transfer, pressure drop, and the corrosion and erosion of materials in the flowing system.

  13. Effect of Heat Exchanger Material and Fouling on Thermoelectric Exhaust Heat Recovery

    SciTech Connect (OSTI)

    Love, Norman [University of Texas, El Paso; Szybist, James P [ORNL; Sluder, Scott [ORNL

    2011-01-01T23:59:59.000Z

    This study is conducted in an effort to better understand and improve the performance of thermoelectric heat recovery systems for automotive use. For this purpose an experimental investigation of thermoelectrics in contact with clean and fouled heat exchangers of different materials is performed. The thermoelectric devices are tested on a bench-scale thermoelectric heat recovery apparatus that simulates automotive exhaust. The thermoelectric apparatus consists of a series of thermoelectric generators contacting a hot-side and a cold-side heat exchanger. The thermoelectric devices are tested with two different hot-side heat exchanger materials, stainless steel and aluminum, and at a range of simulated exhaust gas flowrates (40 to 150 slpm), exhaust gas temperatures (240 C and 280 C), and coolant-side temperatures (40 C and 80 C). It is observed that for higher exhaust gas flowrates, thermoelectric power output increases while overall system efficiency decreases. Degradation of the effectiveness of the EGR-type heat exchangers over a period of driving is also simulated by exposing the heat exchangers to diesel engine exhaust under thermophoretic conditions to form a deposit layer. For the fouled EGR-type heat exchangers, power output and system efficiency is observed to be significantly lower for all conditions tested. The study found, however, that heat exchanger material is the dominant factor in the ability of the system to convert heat to electricity with thermoelectric generators. This finding is thought to be unique to the heat exchangers used for this study, and not a universal trend for all system configurations.

  14. Design of Heat Exchanger for Heat Recovery in CHP Systems

    E-Print Network [OSTI]

    Kozman, T. A.; Kaur, B.; Lee, J.

    The objective of this research is to review issues related to the design of heat recovery unit in Combined Heat and Power (CHP) systems. To meet specific needs of CHP systems, configurations can be altered to affect different factors of the design...

  15. Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems

    SciTech Connect (OSTI)

    Mark Anderson; Greg Nellis; Michael Corradini

    2012-10-19T23:59:59.000Z

    The objective of this project is to produce the necessary data to evaluate the performance of the supercritical carbon dioxide cycle. The activities include a study of materials compatibility of various alloys at high temperatures, the heat transfer and pressure drop in compact heat exchanger units, and turbomachinery issues, primarily leakage rates through dynamic seals. This experimental work will serve as a test bed for model development and design calculations, and will help define further tests necessary to develop high-efficiency power conversion cycles for use on a variety of reactor designs, including the sodium fast reactor (SFR) and very high-temperature gas reactor (VHTR). The research will be broken into three separate tasks. The first task deals with the analysis of materials related to the high-temperature S-CO{sub 2} Brayton cycle. The most taxing materials issues with regard to the cycle are associated with the high temperatures in the reactor side heat exchanger and in the high-temperature turbine. The system could experience pressures as high as 20MPa and temperatures as high as 650C. The second task deals with optimization of the heat exchangers required by the S-CO{sub 2} cycle; the S-CO{sub 2} flow passages in these heat exchangers are required whether the cycle is coupled with a VHTR or an SFR. At least three heat exchangers will be required: the pre-cooler before compression, the recuperator, and the heat exchanger that interfaces with the reactor coolant. Each of these heat exchangers is unique and must be optimized separately. The most challenging heat exchanger is likely the pre-cooler, as there is only about a 40C temperature change but it operates close to the CO{sub 2} critical point, therefore inducing substantial changes in properties. The proposed research will focus on this most challenging component. The third task examines seal leakage through various dynamic seal designs under the conditions expected in the S-CO{sub 2} cycle, including supercritical, choked, and two-phase flow conditions.

  16. Heat energy Q: -energy exchanged between systems if they have a different temperature

    E-Print Network [OSTI]

    Boyd, Sylke

    About heat Heat energy Q: - energy exchanged between systems if they have a different temperature - heat flows from higher to lower temperature - without temperature difference, no heat is exchanged If a system is receiving or releasing heat, then this heat is called a) Sensible heat, if the system changes

  17. Heat treatment of exchangers to remove coke

    SciTech Connect (OSTI)

    Turner, J.D.

    1990-02-20T23:59:59.000Z

    This patent describes a process for preparing furfural coke for removal from metallic surfaces. It comprises: heating the furfural coke without causing an evolution of heat capable of undesirably altering metallurgical properties of the surfaces in the presence of a gas containing molecular oxygen at a sufficient temperature below 800{degrees}F (427{degrees}C) for a sufficient time to change the crush strength of the coke so as to permit removal with a water jet at a pressure of five thousand pounds per square inch.

  18. Diffusion Welding of Compact Heat Exchangers for Nuclear Applications

    SciTech Connect (OSTI)

    Denis Clark; Ron Mizia; Dr. Michael V. Glazoff; Mr. Michael W. Patterson

    2012-06-01T23:59:59.000Z

    The next--generation nuclear plant (NGNP) is designed to be a flexible source of energy, producing various mixes of electrical energy and process heat (for example, for hydrogen generation) on demand. Compact heat exchangers provide an attractive way to move energy from the helium primary reactor coolant to process heat uses. For process heat efficiency, reactor outlet temperatures of 750--900C are desirable. There are minor but deleterious components in the primary coolant; the number of alloys that can handle this environment is small. The present work concentrates on Alloys 800H and 617.

  19. Sludge, fuel degradation and reducing fouling on heat exchangers

    SciTech Connect (OSTI)

    Butcher, T.; Litzke, Wai Lin; Krajewski, R.; Celebi, Y.

    1992-02-01T23:59:59.000Z

    Brookhaven National Laboratory, under contract to the US Department of Energy, operates an oil heat research primarily to lower energy consumption in the 12 million oil heated homes in the US. The program objectives include: Improve steady state efficiency of oil heating equipment, Improve seasonal efficiencies, Eliminate or minimize factors which tend to degrade system performance. This paper provides an overview of the status of three specific projects which fall under the above objectives. This includes our fuel quality project, oil appliance venting and a project addressing efficiency degradation due to soot fouling of heat exchangers.

  20. Heat Exchanger Fouling- Prediction, Measurement and Mitigation

    E-Print Network [OSTI]

    Peterson, G. R.

    wall. The fouling probe has been successfully tested in the laboratory at flue gas temperatures up to 2200F and a local heat flux up to 41,000 BTU/hr-ft2. The probe has been field tested at a coal-fired boiler plant. Future tests at a municipal waste...

  1. Supercritical Carbon Dioxide Turbo-Expander and Heat Exchangers

    Broader source: Energy.gov [DOE]

    This fact sheet describes a supercritical carbon dioxide turbo-expander and heat exchangers project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Southwest Research Institute, is working to develop a megawatt-scale s-CO2 hot-gas turbo-expander optimized for the highly transient solar power plant profile. The team is also working to optimize novel printed circuit heat exchangers for s-CO2 applications to drastically reduce their manufacturing costs.

  2. Method of fabricating a heat exchanger for Stirling engine

    SciTech Connect (OSTI)

    Rao, V.D.

    1980-10-28T23:59:59.000Z

    A heat exchange assembly and method for making same is disclosed which is useful for Stirling engine heater head constructions. The assembly is comprised entirely of a low cost extrudable material, such as silicon, which when fused in a carburizing furnace provides a rigid highly durable ceramic. Heater tubes are arranged within a chamber, the tubes carry ambient pressure high temperature combusted gases and the chamber containing high pressure lower temperature working gases about the exterior of each tube. Heat exchange can additionally be improved by increasing the exterior surface area of each tube relative to the interior surface thereof.

  3. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    SciTech Connect (OSTI)

    Mittereder, N.; Poerschke, A.

    2013-11-01T23:59:59.000Z

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.

  4. Design Development Analyses in Support of a Heat pipe-Brayton Cycle Heat Exchanger

    SciTech Connect (OSTI)

    Steeve, Brian E. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Kapernick, Richard J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2004-07-01T23:59:59.000Z

    One of the power systems under consideration for future space exploration applications, including nuclear electric propulsion or as a planetary surface power source, is a heat pipe-cooled reactor coupled to a Brayton cycle. In this system, power is transferred from the heat pipes to the Brayton gas via a heat exchanger attached to the heat pipes. This paper discusses the fluid, thermal and structural analyses that were performed in support of the design of the heat exchanger to be tested in the SAFE-100 experimental program at the Marshall Space Flight Center. An important consideration throughout the design development of the heat exchanger was its capability to be utilized for higher power and temperature applications. This paper also discusses this aspect of the design and presents designs for specific applications that are under consideration. (authors)

  5. Optimized design of a heat exchanger for an air-to-water reversible heat pump working with propane (R290)

    E-Print Network [OSTI]

    Fernández de Córdoba, Pedro

    Optimized design of a heat exchanger for an air-to-water reversible heat pump working with propane-to-water reversible heat pump unit was carried out using two different fin-and-tube heat exchanger ``coil'' designs concepts. The performance of the heat pump was evaluated for each coil design at different superheat

  6. Advanced Rotating Heat Exchangers | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartment of EnergyAdministrative2| Department of Energy 2|Rotating Heat

  7. Xenon Recirculation-Purification with a Heat Exchanger

    E-Print Network [OSTI]

    K. L. Giboni; E. Aprile; B. Choi; T. Haruyama; R. F. Lang; K. E. Lim; A. J. Melgarejo; G. Plante

    2011-03-04T23:59:59.000Z

    Liquid-xenon based particle detectors have been dramatically growing in size during the last years, and are now exceeding the one-ton scale. The required high xenon purity is usually achieved by continuous recirculation of xenon gas through a high-temperature getter. This challenges the traditional way of cooling these large detectors, since in a thermally well insulated detector, most of the cooling power is spent to compensate losses from recirculation. The phase change during recondensing requires five times more cooling power than cooling the gas from ambient temperature to -100C (173 K). Thus, to reduce the cooling power requirements for large detectors, we propose to use the heat from the purified incoming gas to evaporate the outgoing xenon gas, by means of a heat exchanger. Generally, a heat exchanger would appear to be only of very limited use, since evaporation and liquefaction occur at zero temperature difference. However, the use of a recirculation pump reduces the pressure of the extracted liquid, forces it to evaporate, and thus cools it down. We show that this temperature difference can be used for an efficient heat exchange process. We investigate the use of a commercial parallel plate heat exchanger with a small liquid xenon detector. Although we expected to be limited by the available cooling power to flow rates of about 2 SLPM, rates in excess of 12 SLPM can easily be sustained, limited only by the pump speed and the impedance of the flow loop. The heat exchanger operates with an efficiency of (96.8 +/- 0.5)%. This opens the possibility for fast xenon gas recirculation in large-scale experiments, while minimizing thermal losses.

  8. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  9. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1998-07-21T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  10. Integral collector storage system with heat exchange apparatus

    DOE Patents [OSTI]

    Rhodes, Richard O.

    2004-04-20T23:59:59.000Z

    The present invention relates to an integral solar energy collector storage systems. Generally, an integral collector storage system includes a tank system, a plurality of heat exchange tubes with at least some of the heat exchange tubes arranged within the tank system, a first glazing layer positioned over the tank system and a base plate positioned under the tank system. In one aspect of the invention, the tank system, the first glazing layer an the base plate each include protrusions and a clip is provided to hold the layers together. In another aspect of the invention, the first glazing layer and the base plate are ribbed to provide structural support. This arrangement is particularly useful when these components are formed from plastic. In yet another aspect of the invention, the tank system has a plurality of interconnected tank chambers formed from tubes. In this aspect, a supply header pipe and a fluid return header pipe are provided at a first end of the tank system. The heat exchange tubes have inlets coupled to the supply header pipe and outlets coupled to the return header pipe. With this arrangement, the heat exchange tubes may be inserted into the tank chambers from the first end of the tank system.

  11. Condensing Heat Exchanger for Optimization of Energy Efficiency

    E-Print Network [OSTI]

    Carrigan, J. F.; Johnson, D. W.; DiVitto, J. G.; Schulze, K. H.

    Historically, boiler efficiency has been limited due to the minimum temperature allowed at the stack. Heat lost up the stack was in exchange for keeping the flue gas temperature above the water vapor dew point. If water vapor was allowed to condense...

  12. Finned Tube With Vortex Generators For A Heat Exchanger.

    DOE Patents [OSTI]

    Sohal, Manohar S. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID)

    2005-12-20T23:59:59.000Z

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  13. GEA Heat Exchangers GEA Searle Cooler and Condensing Unit Ranges

    E-Print Network [OSTI]

    Frandsen, Søren

    have high efficiency EC fans as standard across the range. All our commercial unit coolers have whiteUnits GEA Searle Condensing Units are supplied as standard to a high specification with a complete controlGEA Heat Exchangers GEA Searle Cooler and Condensing Unit Ranges Top-level engineering solutions

  14. Heat exchanger efficiently operable alternatively as evaporator or condenser

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1981-01-01T23:59:59.000Z

    A heat exchanger adapted for efficient operation alternatively as evaporator or condenser and characterized by flexible outer tube having a plurality of inner conduits and check valves sealingly disposed within the outer tube and connected with respective inlet and outlet master flow conduits and configured so as to define a parallel flow path for a first fluid such as a refrigerant when flowed in one direction and to define a serpentine and series flow path for the first fluid when flowed in the opposite direction. The flexible outer tube has a heat exchange fluid, such as water, flowed therethrough by way of suitable inlet and outlet connections. The inner conduits and check valves form a package that is twistable so as to define a spiral annular flow path within the flexible outer tube for the heat exchange fluid. The inner conduits have thin walls of highly efficient heat transfer material for transferring heat between the first and second fluids. Also disclosed are specific materials and configurations.

  15. Novel Power Electronics Three-Dimensional Heat Exchanger: Preprint

    SciTech Connect (OSTI)

    Bennion, K.; Cousineau, J.; Lustbader, J.; Narumanchi, S.

    2014-08-01T23:59:59.000Z

    Electric drive systems for vehicle propulsion enable technologies critical to meeting challenges for energy, environmental, and economic security. Enabling cost-effective electric drive systems requires reductions in inverter power semiconductor area. As critical components of the electric drive system are made smaller, heat removal becomes an increasing challenge. In this paper, we demonstrate an integrated approach to the design of thermal management systems for power semiconductors that matches the passive thermal resistance of the packaging with the active convective cooling performance of the heat exchanger. The heat exchanger concept builds on existing semiconductor thermal management improvements described in literature and patents, which include improved bonded interface materials, direct cooling of the semiconductor packages, and double-sided cooling. The key difference in the described concept is the achievement of high heat transfer performance with less aggressive cooling techniques by optimizing the passive and active heat transfer paths. An extruded aluminum design was selected because of its lower tooling cost, higher performance, and scalability in comparison to cast aluminum. Results demonstrated a heat flux improvement of a factor of two, and a package heat density improvement over 30%, which achieved the thermal performance targets.

  16. A thin film transistor driven microchannel device

    E-Print Network [OSTI]

    Lee, Hyun Ho

    2005-02-17T23:59:59.000Z

    the conventional slab-type electrophoresis.3 A major problem of protein separation with a CE or microchip electrophoresis is the adsorption of protein molecules to the capillary or microchannel glass wall, where an ion-exchange mechanism exists between... of the capillary or microchannel glass wall can be coated with a linear polyacrylamide or other hydrophobic functional polymer, and (iii) the high ionic strength or buffers containing a high concentration of alkali salts can be used.3,4,6,7 15...

  17. Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall; Ali Siahpush; Michael McKellar; Michael Patterson; Eung Soo Kim

    2012-06-01T23:59:59.000Z

    The goals of next generation nuclear reactors, such as the high temperature gas-cooled reactor and advance high temperature reactor (AHTR), are to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. The need for efficiency, compactness, and safety challenge the boundaries of existing heat exchanger technology, giving rise to the following study. Various studies have been performed in attempts to update the secondary heat exchanger that is downstream of the primary heat exchanger, mostly because its performance is strongly tied to the ability to employ more efficient conversion cycles, such as the Rankine super critical and subcritical cycles. This study considers two different types of heat exchangershelical coiled heat exchanger and printed circuit heat exchangeras possible options for the AHTR secondary heat exchangers with the following three different options: (1) A single heat exchanger transfers all the heat (3,400 MW(t)) from the intermediate heat transfer loop to the power conversion system or process plants; (2) Two heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants, each exchanger transfers 1,700 MW(t) with a parallel configuration; and (3) Three heat exchangers share heat to transfer total heat of 3,400 MW(t) from the intermediate heat transfer loop to the power conversion system or process plants. Each heat exchanger transfers 1,130 MW(t) with a parallel configuration. A preliminary cost comparison will be provided for all different cases along with challenges and recommendations.

  18. Foundation heat exchangers for residential ground source heat pump systems Numerical modeling and experimental validation

    SciTech Connect (OSTI)

    Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University

    2011-01-01T23:59:59.000Z

    A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

  19. Design of compact intermediate heat exchangers for gas cooled fast reactors

    E-Print Network [OSTI]

    Gezelius, Knut, 1978-

    2004-01-01T23:59:59.000Z

    Two aspects of an intermediate heat exchanger (IHX) for GFR service have been investigated: (1) the intrinsic characteristics of the proposed compact printed circuit heat exchanger (PCHE); and (2) a specific design optimizing ...

  20. Heat Exchanger Monitoring and Its Application to Cleaning and Antifoulant Use

    E-Print Network [OSTI]

    Garcia, E.; Leach, S. H.; VanNostrand, W. L.

    1983-01-01T23:59:59.000Z

    of heat exchanger monitoring, the development of an optimum cleaning strategy and the use of antifoulants. This paper presents a brief overview of the heat exchanger monitoring procedure, and through examples, it shows the incentives of monitoring...

  1. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange

    DOE Patents [OSTI]

    McBride, Troy O; Bell, Alexander; Bollinger, Benjamin R; Shang, Andrew; Chmiel, David; Richter, Horst; Magari, Patrick; Cameron, Benjamin

    2013-07-02T23:59:59.000Z

    In various embodiments, efficiency of energy storage and recovery systems compressing and expanding gas is improved via heat exchange between the gas and a heat-transfer fluid.

  2. air-to-air heat exchangers: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Heat Exchangers, Heat Transfer, Energy, Phase Change and multiphase process, Renewable energy (Solan, Tidal), Energy Storage, Conversion Cessi, Paola 62 Dealing with...

  3. air-to-air heat exchanger: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Heat Exchangers, Heat Transfer, Energy, Phase Change and multiphase process, Renewable energy (Solan, Tidal), Energy Storage, Conversion Cessi, Paola 62 Dealing with...

  4. Forming liquid sprays in compressed-gas energy storage systems for effective heat exchange

    DOE Patents [OSTI]

    McBride, Troy O.; Bell, Alexander; Bollinger, Benjamin R.

    2012-08-07T23:59:59.000Z

    In various embodiments, efficiency of energy storage and recovery systems compressing and expanding gas is improved via heat exchange between the gas and a heat-transfer fluid.

  5. Thermal performance of direct contact heat exchangers for mixed hydrocarbons

    SciTech Connect (OSTI)

    Sharpe, L. Jr.; Coswami, D.Y.; Demuth, O.J.; Mines, G.

    1985-01-01T23:59:59.000Z

    This paper describes a physical and a mathematical model for evaluating the tray efficiencies for a direct contact heat exchanger (DCHX). The model is then used to determine the efficiencies for tests conducted on a 60kW sieve tray DCHX as heat is transferred from a geofluid (brine) to a working fluid (mixed hydrocarbons). It is assumed that there are three distinct regions in the column based on the state of the working fluid, as follows: Region I - Preheating with no vaporization; Region II - Preheating with moderate vaporization; and Region III - Major vaporization. The boundaries of these regions can be determined from the experimental data. In the model, mass balance and energy balance is written for a tray ''N'' in each of these regions. Finally, the ''tray efficiency'' or ''heat transfer'' effectiveness of the tray is calculated based on the definition that it is the ratio of the actual heat transfer to the maximum possible, thermodynamically.

  6. (Solar clothes dryer and wastewater heat exchanger). Final report

    SciTech Connect (OSTI)

    Baer, B.F.

    1984-12-04T23:59:59.000Z

    The first project investigated the technical possibilities of adapting a domestic electric clothes dryer to utilize solar-heated water as the heat source, replacing electric resistance heat. The second project attempted to extract wastewater heat from a commercial dishwasher to preheat fresh water to be used in the next dish washing cycle. It is felt that the clothes dryer project has met all of intended goals. Although a solar application has some real-world practical problems, the application of a dryer connected directly to the home heating system will prove to be cost-beneficial over the life of a dryer. The additional cost of a heat exchanger is not excessive, and the installation cost, if installed with the initial house plumbing is less than $100. From a practical point of view, the complexity of installing a wastewater heat extracter is considered impractical. The environment in which such equipment must operate is difficult at best, and most restaurants prefer to maintain as simple an operation as possible. If problems were to occur in this type of equipment, the kitchen would effectively be crippled. In conclusion, further research in the concept is not recommended. Recent advances in commercial dishwashers have also considerably reduced the heat losses which accompanied equipment only a few years old.

  7. Energy Recovery By Direct Contact Gas-Liquid Heat Exchange

    E-Print Network [OSTI]

    Fair, J. R.; Bravo, J. L.

    -09-48 Proceedings from the Tenth Annual Industrial Energy Technology Conference, Houston, TX, September 13-15, 1988 passes to the atmosphere. The heated liquid moves through a closed circuit to tubular exchangers where its heat is transferred to a working fluid... are available, For sieve trays, mass transfer efficiency sources have been tabulated by Chan and Fair (1984), 267 ESL-IE-88-09-48 Proceedings from the Tenth Annual Industrial Energy Technology Conference, Houston, TX, September 13-15, 1988 When only mass...

  8. Microcomputer analysis of regenerative heat exchangers for oscillating flow

    SciTech Connect (OSTI)

    Hutchinson, R.A.; Lyke, S.E.

    1987-03-01T23:59:59.000Z

    Regenerative heat exchangers for use in oscillating flows such as those occurring in Stirling engines present considerable analytical problems to the thermal engineer. A simplified finite element analysis has been implemented in a spreadsheet, providing improved access to analytical assumptions and allowing parametric analysis of current heat transfer data. In addition, an irreversibility analysis has been implemented using the thermal and friction results in the spreadsheet. It is suited for evaluation and insights into loss tradeoffs inside operating regenerators, to suggest new regenerator design concepts, and to focus experimental work. 22 refs., 13 figs.

  9. Compact Ceramic Heat Exchangers for Corrosive Waste Gas Applications

    E-Print Network [OSTI]

    Laws, W. R.; Reed, G. R.

    1982-01-01T23:59:59.000Z

    in the late 1930's of low-leakage high-pressure metallic recuperators resulted in the gradual demise of ceramic heat exchar~ers. This trend was given further impetus by the rapid fall in oil prices in the 1950's which further reduced the economic... recuperators. Metallic heat exchangers are ideally suited to handlir~ clean waste gases havir~ temperatures rar~ir~ from 300 deg. C to 1050 deg. C and for preheatir~ air up to 550 deg. C as well as low calorific gases to 450 deg. C. Operatir~ metallic...

  10. A Plastic-Core Compact Heat Exchanger for Energy Conservation

    E-Print Network [OSTI]

    Lazaridis, A.; Rafailidis, E.

    is 10 er cost compared to one with a metallic core, but it as the potential of contamination from mOisfre contained in air. All of these heat exchangers su fer from fouling by dust and particulates wile condensation of moisture leads to corrosion... maximum temperature does not exceed 340 K (150?F) while polypropylene is recommended for use up to 370 K (200?F). Fouling of the transfer surfaces has the negative effect of increasing the resistance to heat flow that leads to deterioration...

  11. Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems

    SciTech Connect (OSTI)

    Vierow, Karen

    2005-08-29T23:59:59.000Z

    This report describes a three-year project to investigate the major factors of horizontal heat exchanger performance in passive containment heat removal from a light water reactor following a design basis accident LOCA (Loss of Coolant Accident). The heat exchanger studied in this work may be used in advanced and innovative reactors, in which passive heat removal systems are adopted to improve safety and reliability The application of horizontal tube-bundle condensers to passive containment heat removal is new. In order to show the feasibility of horizontal heat exchangers for passive containment cooling, the following aspects were investigated: 1. the condensation heat transfer characteristics when the incoming fluid contains noncondensable gases 2. the effectiveness of condensate draining in the horizontal orientation 3. the conditions that may lead to unstable condenser operation or highly degraded performance 4. multi-tube behavior with the associated secondary-side effects This project consisted of two experimental investigations and analytical model development for incorporation into industry safety codes such as TRAC and RELAP. A physical understanding of the flow and heat transfer phenomena was obtained and reflected in the analysis models. Two gradute students (one funded by the program) and seven undergraduate students obtained research experience as a part of this program.

  12. Fouling of HVAC fin and tube heat exchangers

    SciTech Connect (OSTI)

    Siegel, Jeffrey; Carey, Van P.

    2001-07-01T23:59:59.000Z

    Fin and tube heat exchangers are used widely in residential, commercial and industrial HVAC applications. Invariably, indoor and outdoor air contaminants foul these heat exchangers. This fouling can cause decreased capacity and efficiency of the HVAC equipment as well as indoor air quality problems related to microbiological growth. This paper describes laboratory studies to investigate the mechanisms that cause fouling. The laboratory experiments involve subjecting a 4.7 fins/cm (12 fins/inch) fin and tube heat exchanger to an air stream that contains monodisperse particles. Air velocities ranging from 1.5-5.2 m/s (295 ft/min-1024 ft/min) and particle sizes from 1--8.6 {micro}m are used. The measured fraction of particles that deposit as well as information about the location of the deposited material indicate that particles greater than about 1 {micro}m contribute to fouling. These experimental results are used to validate a scaling analysis that describes the relative importance of several deposition mechanisms including impaction, Brownian diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The analysis is extended to apply to different fin spacings and particle sizes typical of those found in indoor air.

  13. Natural convection heat exchangers for solar water heating systems. Technical progress report, November 15, 1996--January 14, 1997

    SciTech Connect (OSTI)

    Davidson, J.H.

    1998-06-01T23:59:59.000Z

    The goals of this project are: (1) to develop guidelines for the design and use of thermosypohon side-arm heat exchangers in solar domestic water heating systems, and (2) to establish appropriate modeling and testing criteria for evaluating the performance of systems using this type of heat exchanger.

  14. Engineering Analysis of Intermediate Loop and Process Heat Exchanger Requirements to Include Configuration Analysis and Materials Needs

    SciTech Connect (OSTI)

    T.M. Lillo; R.L. Williamson; T.R. Reed; C.B. Davis; D.M. Ginosar

    2005-09-01T23:59:59.000Z

    The need to locate advanced hydrogen production facilities a finite distance away from a nuclear power source necessitates the need for an intermediate heat transport loop (IHTL). This IHTL must not only efficiently transport energy over distances up to 500 meters but must also be capable of operating at high temperatures (>850oC) for many years. High temperature, long term operation raises concerns of material strength, creep resistance and general material stability (corrosion resistance). IHTL design is currently in the initial stages. Many questions remain to be answered before intelligent design can begin. The report begins to look at some of the issues surrounding the main components of an IHTL. Specifically, a stress analysis of a compact heat exchanger design under expected operating conditions is reported. Also the results of a thermal analysis performed on two ITHL pipe configurations for different heat transport fluids are presented. The configurations consist of separate hot supply and cold return legs as well as annular design in which the hot fluid is carried in an inner pipe and the cold return fluids travels in the opposite direction in the annular space around the hot pipe. The effects of insulation configurations on pipe configuration performance are also reported. Finally, a simple analysis of two different process heat exchanger designs, one a tube in shell type and the other a compact or microchannel reactor are evaluated in light of catalyst requirements. Important insights into the critical areas of research and development are gained from these analyses, guiding the direction of future areas of research.

  15. Fouling of HVAC Fin and Tube Heat Exchangers Jeffrey Siegel and Van P. Carey

    E-Print Network [OSTI]

    Fouling of heat exchangers used in heating, ventilating, and air conditioning (HVAC) systems is important contributor to overall energy use and peak electric demand. Furthermore, the location of heat exchangers in HVAC systems means that if bioaerosols containing bacteria, fungi, and viruses deposit on heat

  16. Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing

    E-Print Network [OSTI]

    Yu, Lisan

    1 Sea surface exchanges of momentum, heat, and freshwater determined by satellite remote sensing Freshwater flux Latent heat flux Longwave radiation Satellite remote sensing Sea surface flux estimation Sensible heat flux Shortwave radiation Surface wind fields 2 #12;Sea surface exchanges of momentum, heat

  17. MULTIPLE POLLUTANT REMOVAL USING THE CONDENSING HEAT EXCHANGER

    SciTech Connect (OSTI)

    B.J. JANKURA; G.A. KUDLAC; R.T. BAILEY

    1998-06-01T23:59:59.000Z

    The Integrated Flue Gas Treatment (IFGT) system is a new concept whereby a Teflon covered condensing heat exchanger is adapted to remove certain flue gas constituents, both particulate and gaseous, while recovering low level heat. The pollutant removal performance and durability of this device is the subject of a USDOE sponsored program to develop this technology. The program was conducted under contract to the United States Department of Energy?s Fossil Energy Technology Center (DOE-FETC) and was supported by the Ohio Coal Development Office (OCDO) within the Ohio Department of Development, the Electric Power Research Institute?s Environmental Control Technology Center (EPRI-ECTC) and Babcock and Wilcox - a McDermott Company (B&W). This report covers the results of the first phase of this program. This Phase I project has been a two year effort. Phase I includes two experimental tasks. One task dealt principally with the pollutant removal capabilities of the IFGT at a scale of about 1.2MWt. The other task studied the durability of the Teflon covering to withstand the rigors of abrasive wear by fly ash emitted as a result of coal combustion. The pollutant removal characteristics of the IFGT system were measured over a wide range of operating conditions. The coals tested included high, medium and low-sulfur coals. The flue gas pollutants studied included ammonia, hydrogen chloride, hydrogen fluoride, particulate, sulfur dioxide, gas phase and particle phase mercury and gas phase and particle phase trace elements. The particulate removal efficiency and size distribution was investigated. These test results demonstrated that the IFGT system is an effective device for both acid gas absorption and fine particulate collection. Although soda ash was shown to be the most effective reagent for acid gas absorption, comparative cost analyses suggested that magnesium enhanced lime was the most promising avenue for future study. The durability of the Teflon covered heat exchanger tubes was studied on a pilot-scale single- stage condensing heat exchanger (CHX ). This device was operated under typical coal-fired flue gas conditions on a continuous basis for a period of approximately 10 months. Data from the test indicate that virtually no decrease in Teflon thickness was observed for the coating on the first two rows of heat exchanger tubes, even at high inlet particulate loadings. Evidence of wear was present only at the microscopic level, and even then was very minor in severity.

  18. Thermal Performance of Microencapsulated Phase Material (MPCM) Slurry in a Coaxial Heat Exchanger

    E-Print Network [OSTI]

    Yu, Kun

    2014-05-08T23:59:59.000Z

    Microencapsulated phase change material (MPCM) slurries and coil heat exchangers had been recently studied separately as enhancers of convective heat transfer processes. Due to the larger apparent heat related to the phase change process...

  19. E-Print Network 3.0 - aluminum heat exchangers Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    rejector consists of an aluminum heat sink... 10 10 Figure 4 Schematic of a typical remote heat exchanger system 12 11 Figure 5 Heat pipe... in laptop computers ... Source:...

  20. Xenon Recirculation-Purification with a Heat Exchanger

    E-Print Network [OSTI]

    Giboni, K L; Choi, B; Haruyama, T; Lang, R F; Lim, K E; Melgarejo, A J; Plante, G; 10.1088/1748-0221/6/03/P03002

    2011-01-01T23:59:59.000Z

    Liquid-xenon based particle detectors have been dramatically growing in size during the last years, and are now exceeding the one-ton scale. The required high xenon purity is usually achieved by continuous recirculation of xenon gas through a high-temperature getter. This challenges the traditional way of cooling these large detectors, since in a thermally well insulated detector, most of the cooling power is spent to compensate losses from recirculation. The phase change during recondensing requires five times more cooling power than cooling the gas from ambient temperature to -100C (173 K). Thus, to reduce the cooling power requirements for large detectors, we propose to use the heat from the purified incoming gas to evaporate the outgoing xenon gas, by means of a heat exchanger. Generally, a heat exchanger would appear to be only of very limited use, since evaporation and liquefaction occur at zero temperature difference. However, the use of a recirculation pump reduces the pressure of the extracted liquid...

  1. Vertical Concentric Tube Ground Couoled Heat Exchangers V. C. Mei and S. K. Fischer*

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    to extract heat from or reject heat to the environment. The majority of heat pumps use ambient air of the air. Ground water is a better heat source/sink for heat pump application (due to its superior thermal exchangers for use in heat-pump applications is described. The experimental apparatus consists

  2. Aging management guideline for commercial nuclear power plants - heat exchangers

    SciTech Connect (OSTI)

    Booker, S.; Lehnert, D.; Daavettila, N.; Palop, E.

    1994-06-01T23:59:59.000Z

    This Aging Management Guideline (AMG) describes recommended methods for effective detection and mitigation of age-related degradation mechanisms in commercial nuclear power plant heat exchangers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein.

  3. Integrated heat exchanger design for a cryogenic storage tank

    SciTech Connect (OSTI)

    Fesmire, J. E.; Bonner, T.; Oliveira, J. M.; Johnson, W. L.; Notardonato, W. U. [NASA Kennedy Space Center, Cryogenics Test Laboratory, NE-F6, KSC, FL 32899 (United States); Tomsik, T. M. [NASA Glenn Research Center, 21000 Brookpark Road, Cleveland, OH 44135 (United States); Conyers, H. J. [NASA Stennis Space Center, Building 3225, SSC, MS 39529 (United States)

    2014-01-29T23:59:59.000Z

    Field demonstrations of liquid hydrogen technology will be undertaken for the proliferation of advanced methods and applications in the use of cryofuels. Advancements in the use of cryofuels for transportation on Earth, from Earth, or in space are envisioned for automobiles, aircraft, rockets, and spacecraft. These advancements rely on practical ways of storage, transfer, and handling of liquid hydrogen. Focusing on storage, an integrated heat exchanger system has been designed for incorporation with an existing storage tank and a reverse Brayton cycle helium refrigerator of capacity 850 watts at 20 K. The storage tank is a 125,000-liter capacity horizontal cylindrical tank, with vacuum jacket and multilayer insulation, and a small 0.6-meter diameter manway opening. Addressed are the specific design challenges associated with the small opening, complete modularity, pressure systems re-certification for lower temperature and pressure service associated with hydrogen densification, and a large 8:1 length-to-diameter ratio for distribution of the cryogenic refrigeration. The approach, problem solving, and system design and analysis for integrated heat exchanger are detailed and discussed. Implications for future space launch facilities are also identified. The objective of the field demonstration will be to test various zero-loss and densified cryofuel handling concepts for future transportation applications.

  4. Performance studies of a solar energy storing heat exchanger

    SciTech Connect (OSTI)

    Bushnell, D.L. (Northern Illinois Univ., DeKalb (USA))

    1988-01-01T23:59:59.000Z

    The design, construction, and performance of a solar energy storing heat exchanger is presented as a step toward a solar cooking concept. The solid-solid transition of pentaerythritol is the principal mechanism for energy storage. The methods for describing the system performance are explained and applied to a test system containing a controllable replacement for the solar input power. This first stage of the project will be followed by another in which the heat exchanger is connected to a concentrating array of CPC cylindrical troughs. Although a size appropriate to commercial cooking may prove easier to design from the point of view of economics in the US, the system discussed herein is sized for domestic use and addresses the question of what solar collector area and PCM mass are needed in order to provide adequate energy for several family-size meals with sufficient storage to cook at night and one or two days later. The performance is described from efficiency measurements and the determination of a figure of merit.

  5. AN OPTIMIZED TWO-CAPACITY ADVANCED ELECTRIC HEAT PUMP S. E. Veyo, Manager, Heat Exchange Systems Research

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;AN OPTIMIZED TWO-CAPACITY ADVANCED ELECTRIC HEAT PUMP S. E. Veyo S. E. Veyo, Manager, Heat Exchange Systems Research Westinghouse Electric Corporation, R&D Center 1310 Beulah Road Pittsburgh, PA 15235 KEYWORDS: heat pump, air conditioner, electric, residential, energy, compressor, fan, blower, heat

  6. Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers

    E-Print Network [OSTI]

    Thole, Karen A.

    Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance used to increase heat transfer by initiating new boundary layer growth and increasing surface area

  7. Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical delta winglets

    E-Print Network [OSTI]

    Thole, Karen A.

    Heat transfer augmentation along the tube wall of a louvered fin heat exchanger using practical the formation of streamwise vortices and increase heat transfer between a working fluid and the surface on which the winglets are placed. This study investigates the use of delta winglets to augment heat transfer on the tube

  8. Condensing heat exchanger systems for residential/commercial furnaces and boilers. Phase IV

    SciTech Connect (OSTI)

    Razgaitis, R.; Payer, J.H.; Talbert, S.G.; Hindin, B.; White, E.L.; Locklin, D.W.; Cudnik, R.A.; Stickford, G.H.

    1985-10-01T23:59:59.000Z

    The development of condensing heat exchanger systems is studied. In the work reported here, the focus is on the corrosion resistance of materials to condensate produced by gas-fired heating equipment, and the characterization of the spatial variation of condensation corrosivity in condensing heat exchangers.

  9. The Cost of Heat Exchanger Fouling in the U. S. Industries

    E-Print Network [OSTI]

    Rebello, W. J.; Richlen, S. L.; Childs, F.

    and other industries. The 1982 U.S. sales of all industrial heat exchangers, excepting boilers and automotive radiators, was about 285,000 units amounting to about $1.6 billion. The total heat duty of all the heat exchangers in industrial operation...

  10. Numerical computation of 3D heat transfer in complex parallel convective exchangers using generalized Graetz modes

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Numerical computation of 3D heat transfer in complex parallel convective exchangers using insights into the most con- tributing structure to exchanges and transfers. Several examples of heat, whilst many other can be found in a recent review [12]. As quoted in [12] conjugate heat transfer

  11. A Simple Control Scheme for Near-optimal Operation of Parallel Heat Exchanger Systems

    E-Print Network [OSTI]

    Skogestad, Sigurd

    . In the chemical and process industries, large amounts of energy can be saved by using heat recovery in heat exchanger networks, which transfer energy in form of heat Corresponding author: email: skoge@ntnu.no, phone exchanger networks for saving energy and costs has led to a large body of research, and most

  12. Continuation of Studies on Development of ODS Heat Exchanger Tubing

    SciTech Connect (OSTI)

    Lawrence Brown; David Workman; Bimal Kad; Gaylord Smith; Archie Robertson; Ian Wright

    2008-04-15T23:59:59.000Z

    The Department of Energy (DOE), National Energy Technology Center (NETL), has initiated a strategic plan for the development of advanced technologies needed to design and build fossil fuel plants with very high efficiency and environmental performance. These plants, referred to as 'Vision 21' and FutureGen programs by DOE, will produce electricity, chemicals, fuels, or a combination of these products, and possibly secondary products such as steam/heat for industrial use. MA956 is a prime candidate material being considered for a high temperature heat exchanger in the 'Vision 21' and FutureGen programs. This material is an oxide dispersion strengthened (ODS) alloy; however, there are some gaps in the data required to commit to the use of these alloys in a full-size plant. To fill the technology gaps for commercial production and use of the material for 'Advanced Power Generation Systems' this project has performed development activity to significant increase in circumferential strength of MA956 as compared to currently available material, investigated bonding technologies for bonding tube-to-tube joints through joining development, and performed tensile, creep and fire-side corrosion tests to validate the use and fabrication processes of MA956 to heat exchanger tubing applications. Development activities within this projected has demonstrated increased circumferential strength of MA956 tubes through flow form processing. Of the six fabrication technologies for bonding tube-to-tube joints, inertia friction welding (IFW) and flash butt welding (FBW) were identified as processes for joining MA956 tubes. Tensile, creep, and fire-side corrosion test data were generated for both base metal and weld joints. The data can be used for design of future systems employing MA956. Based upon the positive development activities, two test probes were designed and fabricated for field exposure testing at 1204 C ({approx}2200 F) flue gas. The probes contained tube portions with FBW and IFW welded MA956. Field testing of the probes and remaining heat exchanger design activity will be performed by Oak Ridge National Laboratory under DOE Contract DE-AC05-00OR22725.

  13. Analytical Study on Thermal and Mechanical Design of Printed Circuit Heat Exchanger

    SciTech Connect (OSTI)

    Su-Jong Yoon; Piyush Sabharwall; Eung-Soo Kim

    2013-09-01T23:59:59.000Z

    The analytical methodologies for the thermal design, mechanical design and cost estimation of printed circuit heat exchanger are presented in this study. In this study, three flow arrangements of parallel flow, countercurrent flow and crossflow are taken into account. For each flow arrangement, the analytical solution of temperature profile of heat exchanger is introduced. The size and cost of printed circuit heat exchangers for advanced small modular reactors, which employ various coolants such as sodium, molten salts, helium, and water, are also presented.

  14. Erosion of heat exchanger tubes in fluidized beds

    SciTech Connect (OSTI)

    Johnson, E.K.; Flemmer, R.L.C.

    1991-01-01T23:59:59.000Z

    This final report describes the activities of the 3-year project entitled Erosion of Heat Exchanger Tubes In Fluidized Beds.'' which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. [times] 24in. fluidized bed, comparative wear results In a 6in. [times] 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. [times] 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. [times] 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. [times] 24in. bed and the modeling of the tube wear in the 24in. [times] 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.

  15. Heat transfer and combustion characteristics of a burner with a rotary regenerative heat exchanger

    SciTech Connect (OSTI)

    Hirose, Yasuo; Kaji, Hitoshi; Arai, Norio

    1998-07-01T23:59:59.000Z

    The authors have developed a Rotary Regenerative Combustion (RRX) System, which is coupled with a compact high efficiency regenerative air heat exchanger and a combustion burner. This system contributes to saving energy of fuel firing industrial furnaces and decreases NO{sub x} emission. This technology can be considered as a solution of greenhouse problem. This paper, discusses a compact high efficiency regenerative air heat exchanger in comparison with the existing types of regenerative burners and reverse firing with high momentum fuel jet (with motive fluid) in the furnace. This burner is compact in size, with high fuel efficiency, low NOx emission, easy to operate, and reliable, based on the results of field tests and commercial operations. The authors can say that the RRX system is a regenerative burner of the second generation.

  16. E-Print Network 3.0 - active heat exchange Sample Search Results

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    6 Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 Summary: Pumps on vertical heat exchangers (probes) thanks to: - the implementation of a "quality...

  17. Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers

    SciTech Connect (OSTI)

    Uvan Catton; Vijay K. Dhir; Deepanjan Mitra; Omar Alquaddoomi; Pierangelo Adinolfi

    2004-04-06T23:59:59.000Z

    Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers.

  18. Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets

    SciTech Connect (OSTI)

    O'Brien, James Edward; Sohal, Manohar Singh

    2000-11-01T23:59:59.000Z

    This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with a circular tube and/or a delta-winglet pair. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.51 x 10-3 to 14.0 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 670 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of a circular tube, a delta-winglet pair, and a combination of a circular tube and a delta-winglet pair. Comparisons of local and average heat transfer distributions for the circular tube with and without winglets are provided. Overall mean finsurface Nusselt-number results indicate a significant level of heat transfer enhancement associated with the deployment of the winglets with the circular cylinder. At the lowest Reynolds numbers (which correspond to the laminar operating conditions of existing geothermal air-cooled condensers), the enhancement level is nearly a factor of two. At higher Reynolds numbers, the enhancement level is close to 50%.

  19. Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results

    SciTech Connect (OSTI)

    O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

    2002-08-01T23:59:59.000Z

    A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

  20. Heat exchanger design for thermoelectric electricity generation from low temperature flue gas streams .

    E-Print Network [OSTI]

    Latcham, Jacob G. (Jacob Greco)

    2009-01-01T23:59:59.000Z

    ??An air-to-oil heat exchanger was modeled and optimized for use in a system utilizing a thermoelectric generator to convert low grade waste heat in flue (more)

  1. Heat exchanger design for thermoelectric electricity generation from low temperature flue gas streams

    E-Print Network [OSTI]

    Latcham, Jacob G. (Jacob Greco)

    2009-01-01T23:59:59.000Z

    An air-to-oil heat exchanger was modeled and optimized for use in a system utilizing a thermoelectric generator to convert low grade waste heat in flue gas streams to electricity. The NTU-effectiveness method, exergy, and ...

  2. The effects of outdoor heat exchanger hydrophobic treatment on the performance of an air source heat pump

    E-Print Network [OSTI]

    Parker, Brandon DeWayne

    1995-01-01T23:59:59.000Z

    mode, the system must remove heat from the cold outdoor air and provide it to the conditioned space. To remove the heat from the outdoor air, the refrigerant entering the outdoor heat exchanger must be colder than the outdoor air. The outdoor air... is pulled across the heat exchanger surface by the outdoor fan Hence, the cold liquid refrigerant passing through the evaporator coil receives heat from the outdoor ambient air passing over the coil, causing the refrigerant to vaporize into a cool gas...

  3. Deposition of biological aerosols on HVAC heat exchangers

    SciTech Connect (OSTI)

    Siegel, Jeffrey; Walker, Ian

    2001-09-01T23:59:59.000Z

    Many biologically active materials are transported as bioaerosols 1-10 {micro}m in diameter. These particles can deposit on cooling and heating coils and lead to serious indoor air quality problems. This paper investigates several of the mechanisms that lead to aerosol deposition on fin and tube heat exchangers. A model has been developed that incorporates the effects of several deposition mechanisms, including impaction, Brownian and turbulent diffusion, turbophoresis, thermophoresis, diffusiophoresis, and gravitational settling. The model is applied to a typical range of air velocities that are found in commercial and residential HVAC systems 1 - 6 m/s (200 - 1200 ft/min), particle diameters from 1 - 8 {micro}m, and fin spacings from 3.2 - 7.9 fins/cm (8 - 16 fins/inch or FPI). The results from the model are compared to results from an experimental apparatus that directly measures deposition on a 4.7 fins/cm (12 FPI) coil. The model agrees reasonably well with this measured data and suggests that cooling coils are an important sink for biological aerosols and consequently a potential source of indoor air quality problems.

  4. Energy, Exergy and Uncertainty Analyses of the Thermal Response Test for a Ground Heat Exchanger

    E-Print Network [OSTI]

    Al-Shayea, Naser Abdul-Rahman

    exchanger, Ground coupled heat pump Corresponding author, Tel.: +1-617-308-7214, Fax: +1-617-253-3484, E calibration DAS data acquisition system g ground H heater loss1 losses from the heating section loss2 losses heating and cooling, water heating, crop drying, agricultural greenhouses, etc. In vertical U

  5. Feasibility Study of Secondary Heat Exchanger Concepts for the Advanced High Temperature Reactor

    SciTech Connect (OSTI)

    Piyush Sabharwall

    2011-09-01T23:59:59.000Z

    The work reported herein represents a significant step in the preliminary design of heat exchanger options (material options, thermal design, selection and evaluation methodology with existing challenges). The primary purpose of this study is to aid in the development and selection of the required heat exchanger for power production using either a subcritical or supercritical Rankine cycle.

  6. Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes

    SciTech Connect (OSTI)

    O'Brien, James Edward; Sohal, Manohar Singh

    2000-08-01T23:59:59.000Z

    This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

  7. An Experimental Study of Upward and Downward Flow of Supercritical Carbon Dioxide in a Straight Pipe Heat Exchanger with Constant Wall Heat Flux

    E-Print Network [OSTI]

    Umrigar, Eric Dara

    2014-05-01T23:59:59.000Z

    An experimental analysis was conducted on a single circular tube heat exchanger using supercritical carbon dioxide as the working fluid. The heat exchanger was operated in two different orientations: vertically upward and downward. The experimental...

  8. Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes

    E-Print Network [OSTI]

    Fullerton, Tracy

    2012-02-14T23:59:59.000Z

    Laminar, two-dimensional, constant-property numerical simulations of flat tube heat exchanger devices operating in flow regimes in which self-sustained oscillations occur were performed. The unsteady flow regimes were transition flow regimes...

  9. Method for producing components with internal architectures, such as micro-channel reactors, via diffusion bonding sheets

    DOE Patents [OSTI]

    Alman, David E. (Corvallis, OR); Wilson, Rick D. (Corvallis, OR); Davis, Daniel L. (Albany, OR)

    2011-03-08T23:59:59.000Z

    This invention relates to a method for producing components with internal architectures, and more particularly, this invention relates to a method for producing structures with microchannels via the use of diffusion bonding of stacked laminates. Specifically, the method involves weakly bonding a stack of laminates forming internal voids and channels with a first generally low uniaxial pressure and first temperature such that bonding at least between the asperites of opposing laminates occurs and pores are isolated in interfacial contact areas, followed by a second generally higher isostatic pressure and second temperature for final bonding. The method thereby allows fabrication of micro-channel devices such as heat exchangers, recuperators, heat-pumps, chemical separators, chemical reactors, fuel processing units, and combustors without limitation on the fin aspect ratio.

  10. Numerical Study on Crossflow Printed Circuit Heat Exchanger for Advanced Small Modular Reactors

    SciTech Connect (OSTI)

    Su-Jong Yoon [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Piyush Sabharwall [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Eung-Soo Kim [Seoul National Univ., Seoul (Korea, Republic of)

    2014-03-01T23:59:59.000Z

    Various fluids such as water, gases (helium), molten salts (FLiNaK, FLiBe) and liquid metal (sodium) are used as a coolant of advanced small modular reactors (SMRs). The printed circuit heat exchanger (PCHE) has been adopted as the intermediate and/or secondary heat exchanger of SMR systems because this heat exchanger is compact and effective. The size and cost of PCHE can be changed by the coolant type of each SMR. In this study, the crossflow PCHE analysis code for advanced small modular reactor has been developed for the thermal design and cost estimation of the heat exchanger. The analytical solution of single pass, both unmixed fluids crossflow heat exchanger model was employed to calculate a two dimensional temperature profile of a crossflow PCHE. The analytical solution of crossflow heat exchanger was simply implemented by using built in function of the MATLAB program. The effect of fluid property uncertainty on the calculation results was evaluated. In addition, the effect of heat transfer correlations on the calculated temperature profile was analyzed by taking into account possible combinations of primary and secondary coolants in the SMR systems. Size and cost of heat exchanger were evaluated for the given temperature requirement of each SMR.

  11. Research for Advanced Heat Exchangers- The U.S. DOE Program

    E-Print Network [OSTI]

    Richlen, S. L.

    to be developed with the recuperator if DOE's developments were to have an impact on the high temperature heat exchangers. The next series of proj ects following the pioneering efforts supported by DOE were system designs that included all aspects... Programs has made significant contributions to the development of advanced heat exchanger technology to save energy for U.S. industry. Currently the Program is field testing two large ceramic tubular high temperature waste heat recuperators and one...

  12. The Role of Filtration in Maintaining Clean Heat Exchanger Coils

    SciTech Connect (OSTI)

    Li Yang; James E. Braun; Eckhard A. Groll

    2004-06-30T23:59:59.000Z

    The main purpose of the study was to investigate the role of filtration in maintaining clean heat exchanger coils and overall performance. Combinations of 6 different levels of filtration (MERV 14, 11, 8, 6, 4, and no filter) and 4 different coils (an eight-row lanced-fin coil, HX8L), (an eight-row wavy-fin coil, HX8W), (a four-row lanced-fin coil, HX4L) and (a two-row lanced-fin coil, HX2L) were tested at 4 different air velocities (1.52, 2.03, 2.54,3.05 m/s (300, 400, 500, 600 ft/min)). The fouled conditions were obtained after injection of 600 grams of ASHRAE standard dust upstream of the filter/coil combination. This magnitude of dust is representative of a year of normal operation for an air conditioning system. The air-side pressure drops of the coils and filters and air-side heat transfer coefficients of the coils were determined from the measurements under the clean and fouled conditions. Depending upon the filter and coil test, the coil pressure drops increased in the range of 6%-30% for an air velocity at 2.54 m/s (500 ft/min). The impact was significantly greater for tests performed without a filter. The largest relative effect of fouling on pressure drop occurs for coils with fewer rows and having lanced fins. Coils with a greater number of rows can hold more dust so that a fixed amount of dust has a relatively smaller impact. The impact of fouling on air-side heat transfer coefficients was found to be relatively small. In some cases, heat transfer was actually enhanced due to additional turbulence caused by the presence of dust. The experimental results for pressure drops and heat transfer coefficients were correlated and the correlations were implemented within computer models of prototypical rooftop air conditioners and used to evaluate the impact of fouling on cooling capacity and EER. The equipment cooling capacity is reduced with fouling primarily because of a decrease in air flow due to the increase pressure drop rather than due to changes in h eat transfer coefficient. In most cases, the EER was reduced with fouling primarily due to increased fan power. However, the changes in EER were relatively small, in the range of 1%-9% (10%). For most cases, equipment having low efficiency filters had higher EER after fouling than equipment with high efficiency filters, because the high efficiency filter caused significantly higher pressure drops than the low efficiency filters. The extra filter pressure drop outweighed the reduced coil pressure drop after fouling. The impact of fan efficiency curves was also investigated in the study. The energy penalty associated with high efficiency filters was reduced considerably with higher efficiency fans. There is an energy penalty associated with the use of high efficiency filtration. However, the primary reason for selecting high efficiency filters for a particular application would be improved air quality. For HX8L, the quantity of dust passing through the coil with a MERV4 filter was approximately 30 times the dust passing the coil with a MERV14 filter. Without an upstream filter, the quantity of dust passing through the coil was approximately 60 times the value for a MERV14 filter.

  13. Description of emission control using fluidized-bed, heat-exchange technology

    SciTech Connect (OSTI)

    Vogel, G.J.; Grogan, P.J.

    1980-06-01T23:59:59.000Z

    Environmental effects of fluidized-bed, waste-heat recovery technology are identified. The report focuses on a particular configuration of fluidized-bed, heat-exchange technology for a hypothetical industrial application. The application is a lead smelter where a fluidized-bed, waste-heat boiler (FBWHB) is used to control environmental pollutants and to produce steam for process use. Basic thermodynamic and kinetic information for the major sulfur dioxide (SO/sub 2/) and NO/sub x/ removal processes is presented and their application to fluidized-bed, waste heat recovery technology is discussed. Particulate control in fluidized-bed heat exchangers is also discussed.

  14. Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

    DOE Patents [OSTI]

    Phillips, Benjamin A. (Benton Harbor, MI); Zawacki, Thomas S. (St. Joseph, MI)

    1996-11-05T23:59:59.000Z

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

  15. Statistical properties of the energy exchanged between two heat baths coupled by thermal fluctuations

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    particles kept at different temperatures and coupled by an elastic force. We measure the heat flowingStatistical properties of the energy exchanged between two heat baths coupled by thermal systems in contact with a single heat bath and driven out of equilibrium by external forces [1, 2, 3, 4, 5

  16. Ground heat exchanger design for direct geothermal energy systems .

    E-Print Network [OSTI]

    COLLS, STUART

    2013-01-01T23:59:59.000Z

    ??Direct geothermal energy systems use the ground to heat and cool buildings. Ground-source heat pump (GSHP) systems are the most widespread form of direct geothermal (more)

  17. MULTI-SCALE MODELING AND APPROXIMATION ASSISTED OPTIMIZATION OF BARE TUBE HEAT EXCHANGERS

    SciTech Connect (OSTI)

    Bacellar, Daniel [University of Maryland, College Park; Ling, Jiazhen [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Radermacher, Reinhard [University of Maryland, College Park; Abdelaziz, Omar [ORNL

    2014-01-01T23:59:59.000Z

    Air-to-refrigerant heat exchangers are very common in air-conditioning, heat pump and refrigeration applications. In these heat exchangers, there is a great benefit in terms of size, weight, refrigerant charge and heat transfer coefficient, by moving from conventional channel sizes (~ 9mm) to smaller channel sizes (< 5mm). This work investigates new designs for air-to-refrigerant heat exchangers with tube outer diameter ranging from 0.5 to 2.0mm. The goal of this research is to develop and optimize the design of these heat exchangers and compare their performance with existing state of the art designs. The air-side performance of various tube bundle configurations are analyzed using a Parallel Parameterized CFD (PPCFD) technique. PPCFD allows for fast-parametric CFD analyses of various geometries with topology change. Approximation techniques drastically reduce the number of CFD evaluations required during optimization. Maximum Entropy Design method is used for sampling and Kriging method is used for metamodeling. Metamodels are developed for the air-side heat transfer coefficients and pressure drop as a function of tube-bundle dimensions and air velocity. The metamodels are then integrated with an air-to-refrigerant heat exchanger design code. This integration allows a multi-scale analysis of air-side performance heat exchangers including air-to-refrigerant heat transfer and phase change. Overall optimization is carried out using a multi-objective genetic algorithm. The optimal designs found can exhibit 50 percent size reduction, 75 percent decrease in air side pressure drop and doubled air heat transfer coefficients compared to a high performance compact micro channel heat exchanger with same capacity and flow rates.

  18. Multiple pollutant removal using the condensing heat exchanger. Task 3, Long term testing at the ECTC

    SciTech Connect (OSTI)

    Schulze, K.H.

    1996-01-01T23:59:59.000Z

    The objective of this task is to demonstrate long term operation of a condensing heat exchanger for coal-fired conditions. A small condensing heat exchanger will be installed at the Environmental Control Technology Center in Barker, New York. It will be installed downstream of the flue gas particulate removal system. The test will determine the amount of wear, if any, on the Teflon{trademark} covered internals of the heat exchanger. Visual inspection and measurements will be obtained for the Teflon{trademark} covered tubes during the test. The material wear study will conducted over a one year calendar period, and the CHX equipment will be operated to the fullest extent allowable.

  19. Effects of slitted fins on the heat transfer and pressure drop characteristics of a compact heat exchanger

    SciTech Connect (OSTI)

    Kim, C.H.; Yun, J.Y. [LG Electronics Living System Research Lab., Seoul (Korea, Republic of)

    1996-12-31T23:59:59.000Z

    A compact heat exchanger which consists of air-cooled aluminum fins and copper tubes circulating refrigerant has been used in a cooling system for a long time. There are two key parameters to be seriously considered for a design of the heat exchanger and its performance improvement. These are the heat transfer rate and pressure drop coefficient which varies with the change of the tube size, its arrangement and the fin configuration. In here, a numerical study was carried to understand the effect of the fin configuration on the heat transfer and pressure drop of the heat exchanger. The diameter and the arrangement of tubes were fixed but three different types of the fin configuration were used to see its effect on the heat transfer capacity and the static pressure drop. The calculation results were compared with that of a flat plate fin. From the comparison, it was found that the slitted fins have higher pressure drop; however, they have higher heat transfer rate. It means that the simpler of the fin configuration, the lower pressure drop and heat transfer coefficients are obtained. It is mainly due to the discretisation of the thermal boundary layer on the fin surface to maximize the heat transfer to air. The slitted sides of fins act like obstacles in the airflow path. From the experimental result, it was found that the same trend in the variation of the heat transfer rate and the pressure drop with the change of the fin configuration was obtained.

  20. Progress Report for Diffusion Welding of the NGNP Process Application Heat Exchangers

    SciTech Connect (OSTI)

    R.E. Mizia; D.E. Clark; M.V. Glazoff; T.E. Lister; T.L. Trowbridge

    2011-12-01T23:59:59.000Z

    The U.S. Department of Energy selected the high temperature gas-cooled reactor as the basis for the Next Generation Nuclear Plant (NGNP). The NGNP will demonstrate the use of nuclear power for electricity, hydrogen production, and process heat applications. The NGNP Project is currently investigating the use of metallic, diffusion welded, compact heat exchangers to transfer heat from the primary (reactor side) heat transport system to the secondary heat transport system. An intermediate heat exchanger will transfer this heat to downstream applications such as hydrogen production, process heat, and electricity generation. The channeled plates that make up the heat transfer surfaces of the intermediate heat exchanger will have to be assembled into an array by diffusion welding. This report describes the preliminary results of a scoping study that evaluated the diffusion welding process parameters and the resultant mechanical properties of diffusion welded joints using Alloy 800H. The long-term goal of the program is to progress towards demonstration of small heat exchanger unit cells fabricated with diffusion welds. Demonstration through mechanical testing of the unit cells will support American Society of Mechanical Engineers rules and standards development, reduce technical risk, and provide proof of concept for heat exchanger fabrication methods needed to deploy heat exchangers in several potential NGNP configurations.1 Researchers also evaluated the usefulness of modern thermodynamic and diffusion computational tools (Thermo-Calc and Dictra) in optimizing the parameters for diffusion welding of Alloy 800H. The modeling efforts suggested a temperature of 1150 C for 1 hour with an applied pressure of 5 MPa using 15 {micro}m nickel foil as joint filler to reduce chromium oxidation on the welded surfaces. Good agreement between modeled and experimentally determined concentration gradients was achieved

  1. Drying and first heat up of a kiln unit with cyclone heat exchangers with a lining of refractory concretes

    SciTech Connect (OSTI)

    Petrov-Denisov, V.G.; Matveev, Y.V.; Pichkov, A.M.; Pozdnyakova, N.K.; Shakhov, I.I.

    1985-11-01T23:59:59.000Z

    This paper describes an accelerated drying and first heatup cycle developed for a kiln unit for dry production of clinker with a capacity of 3000 tons/day with cyclone heat exchangers of refractory concretes of high-alumina cement with a chamotte aggregate. The drying of the lining and the heating of the unit were done in 4 days. The results of the work indicate the desirability of use of refractory concretes for lining the cyclone heat exchangers of kiln units for dry production of clinker.

  2. Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties

    SciTech Connect (OSTI)

    Hansen, B.J.; White, M.J.; Klebaner, A.; /Fermilab

    2011-06-10T23:59:59.000Z

    Future superconducting radio frequency (SRF) cavities, as part of Project X at Fermilab, will be cooled to superfluid helium temperatures by a cryogenic distribution system supplying cold supercritical helium. To reduce vapor fraction during the final Joule-Thomson (J-T) expansion into the superfluid helium cooling bath, counter-flow, plate-fin heat exchangers will be utilized. Due to their compact size and ease of fabrication, plate-fin heat exchangers are an effective option. However, the design of compact and high-effectiveness cryogenic heat exchangers operating at liquid helium temperatures requires consideration of axial heat conduction along the direction of flow, in addition to variable fluid properties. Here we present a numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger. The model is used to guide design decisions on heat exchanger material choice and geometry. In addition, the J-T expansion process is modeled with the heat exchanger to analyze the effect of heat load and cryogenic supply parameters. A numerical model that includes the effects of axial conduction and variable properties for a plate fin heat exchanger was developed and the effect of various design parameters on overall heat exchanger size was investigated. It was found that highly conductive metals should be avoided in the design of compact JT heat exchangers. For the geometry considered, the optimal conductivity is around 3.5 W/m-K and can range from 0.3-10 W/m-K without a large loss in performance. The model was implemented with an isenthalpic expansion process. Increasing the cold side inlet temperature from 2K to 2.2 K decreased the liquid fraction from 0.856 to 0.839 which corresponds to a 0.12 g/s increase in supercritical helium supply needed to maintain liquid level in the cooling bath. Lastly, it was found that the effectiveness increased when the heat load was below the design value. Therefore, the heat exchanger should be sized on the high end of the required heat load.

  3. DIRECT CONTACT HEAT EXCHANGER 10 kW POWER LOOP. SECTION 1: EXECUTIVE SUMMARY. SECTION 2: TEST SERIES NO. 1. SECTION 3; TEST SERIES NO. 2

    E-Print Network [OSTI]

    Engineering, Barber-Nicholas

    2011-01-01T23:59:59.000Z

    Heat Exchangers to Geothermal Power Production Cycles",Heat Exchanger to Geothermal Power Production Cycles",4057702. o m SUMMARY The geothermal power loop was modified

  4. Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions

    E-Print Network [OSTI]

    Westheimer, David Thomas

    2000-01-01T23:59:59.000Z

    This work examines the effects of gravitational acceleration on the flow boiling process. A test facility focusing on an annular heat exchanger was designed, built out of borosilicate glass, and flown on NASA's KC-135 reduced gravity airplane...

  5. DETAILED LOOP MODEL (DLM) ANALYSIS OF LIQUID SOLAR THERMOSIPHONS WITH HEAT EXCHANGERS

    E-Print Network [OSTI]

    Mertol, A.

    2013-01-01T23:59:59.000Z

    a Collector- Cum-Storage Type of ar Water Heater, 11 SolarSolar Water Heater of the Combined Collector and Storagethermosiphon water heaters with heat exchangers in storage

  6. Microchannels and Minichannels -2004 June 17-19, 2004, Rochester, New York, USA

    E-Print Network [OSTI]

    Kandlikar, Satish

    more aggressive cooling techniques, such as flow boiling, are considered. INTRODUCTION Microchannel by ASME ICMM2004 xxxx SINGLE-PHASE HEAT TRANSFER ENHANCEMENT TECHNIQUES IN MICROCHANNEL AND MINICHANNEL@rit.edu, 2 sgkeme@rit.edu ABSTRACT The single-phase heat transfer enhancement techniques are well established

  7. air heat exchanger: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: Solar air heating system for combined DHW and space heating solar air collector PV-panel fannon-return valve DHW tank mantle cold waterhot water roof Solar Energy Centre...

  8. air heat exchangers: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: Solar air heating system for combined DHW and space heating solar air collector PV-panel fannon-return valve DHW tank mantle cold waterhot water roof Solar Energy Centre...

  9. Monolithic microchannel heatsink

    DOE Patents [OSTI]

    Benett, William J. (Livermore, CA); Beach, Raymond J. (Livermore, CA); Ciarlo, Dino R. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    A silicon wafer has slots sawn in it that allow diode laser bars to be mounted in contact with the silicon. Microchannels are etched into the back of the wafer to provide cooling of the diode bars. To facilitate getting the channels close to the diode bars, the channels are rotated from an angle perpendicular to the diode bars which allows increased penetration between the mounted diode bars. This invention enables the fabrication of monolithic silicon microchannel heatsinks for laser diodes. The heatsinks have low thermal resistance because of the close proximity of the microchannels to the laser diode being cooled. This allows high average power operation of two-dimensional laser diode arrays that have a high density of laser diode bars and therefore high optical power density.

  10. Heat as a tracer to determine streambed water exchanges Jim Constantz1

    E-Print Network [OSTI]

    Heat as a tracer to determine streambed water exchanges Jim Constantz1 Received 13 March 2008 of heat as a tracer of shallow groundwater movement and describes current temperature-based approaches relying on traditional observation wells, and remote sensing and other large-scale advanced temperature

  11. Design considerations of a 15kW heat exchanger for the CSPonD Project

    E-Print Network [OSTI]

    Adames, Adrian A

    2010-01-01T23:59:59.000Z

    The objective of this work was to develop a 15 kW heat exchanger model for the CSPonD molten salt receiver that will shuttle the molten salt's thermal energy for conversion to electric power. A heat extraction system ...

  12. NGNP/HTE full-power operation at reduced high-temperature heat exchanger temperatures.

    SciTech Connect (OSTI)

    VIlim, R.; Nuclear Engineering Division

    2009-03-12T23:59:59.000Z

    Operation of the Next Generation Nuclear Plant (NGNP) with reduced reactor outlet temperature at full power was investigated for the High Temperature Electrolysis (HTE) hydrogen-production application. The foremost challenge for operation at design temperature is achieving an acceptably long service life for heat exchangers. In both the Intermediate Heat Exchanger (IHX) and the Process Heat Exchanger (PHX) (referred to collectively as high temperature heat exchangers) a pressure differential of several MPa exists with temperatures at or above 850 C. Thermal creep of the heat exchanger channel wall may severely limit heat exchanger life depending on the alloy selected. This report investigates plant performance with IHX temperatures reduced by lowering reactor outlet temperature. The objective is to lower the temperature in heat transfer channels to the point where existing materials can meet the 40 year lifetime needed for this component. A conservative estimate for this temperature is believed to be about 700 C. The reactor outlet temperature was reduced from 850 C to 700 C while maintaining reactor power at 600 MWt and high pressure compressor outlet at 7 MPa. We included a previously reported design option for reducing temperature at the PHX. Heat exchanger lengths were adjusted to reflect the change in performance resulting from coolant property changes and from resizing related to operating-point change. Turbomachine parameters were also optimized for the new operating condition. An integrated optimization of the complete system including heat transfer equipment was not performed. It is estimated, however, that by performing a pinch analysis the combined plant efficiency can be increased from 35.5 percent obtained in this report to a value between 38.5 and 40.1 percent. Then after normalizing for a more than three percent decrease in commodities inventory compared to the reference plant, the commodities-normalized efficiency lies between 40.0 and 41.3. This compares with a value of 43.9 for the reference plant. This latter plant has a reactor outlet temperature of 850 C and the two high temperature heat exchangers. The reduction in reactor outlet temperature from 850 C to 700 C reduces the tritium permeability rate in the IHX metal by a factor of three and thermal creep by five orders of magnitude. The design option for reducing PHX temperature from 800 C to 200 C reduces the permeability there by three orders of magnitude. In that design option this heat exchanger is the single 'choke-point' for tritium migration from the nuclear to the chemical plant.

  13. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    SciTech Connect (OSTI)

    Edward Levy; Harun Bilirgen; John DuPoint

    2011-03-31T23:59:59.000Z

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: (1) An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing high-moisture, low rank coals. (2) Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. (3) Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. (4) Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. (5) Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. (6) Condensed flue gas water treatment needs and costs. (7) Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. (8) Results of cost-benefit studies of condensing heat exchangers.

  14. Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers

    SciTech Connect (OSTI)

    Levy, Edward; Bilirgen, Harun; DuPont, John

    2011-03-31T23:59:59.000Z

    Most of the water used in a thermoelectric power plant is used for cooling, and DOE has been focusing on possible techniques to reduce the amount of fresh water needed for cooling. DOE has also been placing emphasis on recovery of usable water from sources not generally considered, such as mine water, water produced from oil and gas extraction, and water contained in boiler flue gas. This report deals with development of condensing heat exchanger technology for recovering moisture from flue gas from coal-fired power plants. The report describes: An expanded data base on water and acid condensation characteristics of condensing heat exchangers in coal-fired units. This data base was generated by performing slip stream tests at a power plant with high sulfur bituminous coal and a wet FGD scrubber and at a power plant firing highmoisture, low rank coals. Data on typical concentrations of HCl, HNO{sub 3} and H{sub 2}SO{sub 4} in low temperature condensed flue gas moisture, and mercury capture efficiencies as functions of process conditions in power plant field tests. Theoretical predictions for sulfuric acid concentrations on tube surfaces at temperatures above the water vapor dewpoint temperature and below the sulfuric acid dew point temperature. Data on corrosion rates of candidate heat exchanger tube materials for the different regions of the heat exchanger system as functions of acid concentration and temperature. Data on effectiveness of acid traps in reducing sulfuric acid concentrations in a heat exchanger tube bundle. Condensed flue gas water treatment needs and costs. Condensing heat exchanger designs and installed capital costs for full-scale applications, both for installation immediately downstream of an ESP or baghouse and for installation downstream of a wet SO{sub 2} scrubber. Results of cost-benefit studies of condensing heat exchangers.

  15. Welding of dissimilar alloys for high temperature heat exchangers for SOFC

    SciTech Connect (OSTI)

    Wilson, R.D.; Hatem, J.; Dogan, O.N.; King, P.E.

    2006-10-01T23:59:59.000Z

    Reduction in the cost of balance of plant applications is one of the top priority focus areas for the successful implementation of solid oxide fuel cell technology. High temperature heat exchangers are employed to heat cathode air utilizing either hot gases coming from the anode side of the stack or other hot gases generated by external processes. In order to reduce the cost of heat exchangers, it may be necessary to apply several different materials, each in a different temperature zone, for the construction of the heat exchanger. This technique would require the joining of dissimilar materials in the construction. In this work, welding of commercial candidate dissimilar materials is explored. Filler materials were identified using equilibrium phase diagrams and thermodynamic simulation software. Autogenous welding was performed and the welding defects were characterized. Finally, experimental weld microstructures were compared to phases predicted by the simulations.

  16. Heat Exchanger Design Options and Tritium Transport Study for the VHTR System

    SciTech Connect (OSTI)

    Chang H. Oh; Eung S. Kim

    2008-09-01T23:59:59.000Z

    This report presents the results of a study conducted to consider heat exchanger options and tritium transport in a very high temperature reactor (VHTR) system for the Next Generation Nuclear Plant Project. The heat exchanger options include types, arrangements, channel patterns in printed circuit heat exchangers (PCHE), coolant flow direction, and pipe configuration in shell-and-tube designs. Study considerations include: three types of heat exchanger designs (PCHE, shell-and-tube, and helical coil); single- and two-stage unit arrangements; counter-current and cross flow configurations; and straight pipes and U-tube designs in shell-and-tube type heat exchangers. Thermal designs and simple stress analyses were performed to estimate the heat exchanger options, and the Finite Element Method was applied for more detailed calculations, especially for PCHE designs. Results of the options study show that the PCHE design has the smallest volume and heat transfer area, resulting in the least tritium permeation and greatest cost savings. It is theoretically the most reliable mechanically, leading to a longer lifetime. The two-stage heat exchanger arrangement appears to be safer and more cost effective. The recommended separation temperature between first and second stages in a serial configuration is 800oC, at which the high temperature unit is about one-half the size of the total heat exchanger core volume. Based on simplified stress analyses, the high temperature unit will need to be replaced two or three times during the plants lifetime. Stress analysis results recommend the off-set channel pattern configuration for the PCHE because stress reduction was estimated at up to 50% in this configuration, resulting in a longer lifetime. The tritium transport study resulted in the development of a tritium behavior analysis code using the MATLAB Simulink code. In parallel, the THYTAN code, previously performed by Ohashi and Sherman (2007) on the Peach Bottom data, was revived and verified. The 600 MWt VHTR core input file developed in preparation for the transient tritium analysis of VHTR systems was replaced with the original steady-state inputs for future calculations. A Finite Element Method analysis was performed using COMSOL Multiphysics software to accurately predict tritium permeation through the PCHE type heat exchanger walls. This effort was able to estimate the effective thickness for tritium permeations and develop a correlation for general channel configurations, which found the effective thickness to be much shorter than the average channel distance because of dead spots on the channel side.

  17. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    SciTech Connect (OSTI)

    Hughes, Patrick [ORNL; Im, Piljae [ORNL

    2012-01-01T23:59:59.000Z

    Geothermal heat pumps, sometimes called ground-source heat pumps (GSHPs), have been proven capable of significantly reducing energy use and peak demand in buildings. Conventional equipment for controlling the temperature and humidity of a building, or supplying hot water and fresh outdoor air, must exchange energy (or heat) with the building's outdoor environment. Equipment using the ground as a heat source and heat sink consumes less non-renewable energy (electricity and fossil fuels) because the earth is cooler than outdoor air in summer and warmer in winter. The most important barrier to rapid growth of the GSHP industry is high first cost of GSHP systems to consumers. The most common GSHP system utilizes a closed-loop ground heat exchanger. This type of GSHP system can be used almost anywhere. There is reason to believe that reducing the cost of closed-loop systems is the strategy that would achieve the greatest energy savings with GSHP technology. The cost premium of closed-loop GSHP systems over conventional space conditioning and water heating systems is primarily associated with drilling boreholes or excavating trenches, installing vertical or horizontal ground heat exchangers, and backfilling the excavations. This project investigates reducing the cost of horizontal closed-loop ground heat exchangers by installing them in the construction excavations, augmented when necessary with additional trenches. This approach applies only to new construction of residential and light commercial buildings or additions to such buildings. In the business-as-usual scenario, construction excavations are not used for the horizontal ground heat exchanger (HGHX); instead the HGHX is installed entirely in trenches dug specifically for that purpose. The potential cost savings comes from using the construction excavations for the installation of ground heat exchangers, thereby minimizing the need and expense of digging additional trenches. The term foundation heat exchanger (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of excavation, 50% of which was construction excavation. There are six pipes in all excavations (three par

  18. Hierarchical Modeling for Population-Based Heat Exchanger Design

    E-Print Network [OSTI]

    Geb, David

    2013-01-01T23:59:59.000Z

    layer," Journal of Fluids Engineering, 117(1), pp. 181-journal. Ser. 2, Fluids engineering, heat transfer, power,Networks," Journal of Fluids Engineering, 125(6), pp. 1051-

  19. LIQUID-FLUIDIZED-BED HEAT' EXCHANGER FLOW DISTRIBUTION MODELS

    Office of Scientific and Technical Information (OSTI)

    rods, and shell-side heat transfer coefficients were calculated u s i n g "Newton's Law o f Cooling": a c The horizontal tubes showed a definite angular dependence of the...

  20. Value pricing of surface coatings for mitigating heat exchanger fouling

    E-Print Network [OSTI]

    Wilson, D.I.; Gomes da Cruz, L.; Ishiyama, E.M.; Boxler, C.; Augustin, W.; Scholl, S.

    2014-05-19T23:59:59.000Z

    crystallisation fouling; (b) fluorocarbon-based coatings which offer antifouling performance but can reduce heat transfer, for crystallisation fouling; and (c) fluorocarbon-based coatings in a dairy pasteuriser application. A novel strategy, of replacing stainless...

  1. Review of Current Experience on Intermediate Heat Exchanger (IHX) and A Recommended Code Approach

    SciTech Connect (OSTI)

    Duane Spencer; Kevin McCoy

    2010-02-02T23:59:59.000Z

    The purpose of the ASME/DOE Gen IV Task 7 Part I is to review the current experience on various high temperature reactor intermediate heat exchanger (IHX) concepts. There are several different IHX concepts that could be envisioned for HTR/VHTR applications in a range of temperature from 850C to 950C. The concepts that will be primarily discussed herein are: (1) Tubular Helical Coil Heat Exchanger (THCHE); (2) Plate-Stamped Heat Exchanger (PSHE); (3) Plate-Fin Heat Exchanger (PFHE); and (4) Plate-Machined Heat Exchanger (PMHE). The primary coolant of the NGNP is potentially subject to radioactive contamination by the core as well as contamination from the secondary loop fluid. To isolate the radioactivity to minimize radiation doses to personnel, and protect the primary circuit from contamination, intermediate heat exchangers (IHXs) have been proposed as a means for separating the primary circuit of the NGNP (Next Generation Nuclear Plant) or other process heat application from the remainder of the plant. This task will first review the different concepts of IHX that could be envisioned for HTR/VHTR applications in a range of temperature from 850 to 950 C. This will cover shell-and-tube and compact designs (including the platefin concept). The review will then discuss the maturity of the concepts in terms of design, fabricability and component testing (or feedback from experience when applicable). Particular attention will be paid to the feasibility of developing the IHX concepts for the NGNP with operation expected in 2018-2021. This report will also discuss material candidates for IHX applications and will discuss specific issues that will have to be addressed in the context of the HTR design (thermal aging, corrosion, creep, creep-fatigue, etc). Particular attention will be paid to specific issues associated with operation at the upper end of the creep regime.

  2. ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY

    SciTech Connect (OSTI)

    Kwang J. Kim; Thomas W. Bell; Srinivas Vemuri; Sailaja Govindaraju

    2004-01-01T23:59:59.000Z

    Steam condensation heat transfer on smooth horizontal tubes and enhanced tubes (TURBO-CDI and TURBO-CSL) along with nanoscale hydrophobic coated tubes was studied experimentally. Hydrophobic coatings have been created through self-assembled mono layers (SAMs) on copper alloy (99.9% Cu, 0.1% P) surfaces to enhance steam condensation through dropwise condensation. In general, a SAM system with a long-chain, hydrophobic group is nano-resistant, meaning that such a system forms a protective hydrophobic layer with negligible heat transfer resistance but a much stronger bond. When compared to complete filmwise condensation, the SAM coating on a plain tube increased the condensation heat transfer rate by a factor of 3 for copper alloy surfaces, under vacuum pressure (33.86 kPa) and by a factor of about 8 times when operated at atmospheric pressure (101 kPa). Lifetime of maintaining dropwise condensation is greatly dependent on the processing conditions.

  3. HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM

    SciTech Connect (OSTI)

    Lee, S.; King, W.

    2011-05-23T23:59:59.000Z

    Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds immersed in waste supernate or filled with dry air under various accident scenarios. Accident scenarios evaluated included loss of salt solution flow through the bed, inadvertent column drainage, and loss of active cooling in the column. The modeling results demonstrate that the baseline design using one central and four outer cooling tubes provides a highly efficient cooling mechanism for reducing the maximum column temperature.

  4. Hydrodynamic cavitation and boiling in refrigerant (R-123) flow inside microchannels

    E-Print Network [OSTI]

    Peles, Yoav

    Hydrodynamic cavitation and boiling in refrigerant (R-123) flow inside microchannels Brandon cavitation has on heat transfer. The fluid medium is refrigerant R-123 flowing through 227 lm hydraulic diameter microchannels. The cavitation is instigated by the inlet orifice. Adiabatic tests were con- ducted

  5. Development of Design Criteria for Fluid Induced Structural Vibration in Steam Generators and Heat Exchangers

    SciTech Connect (OSTI)

    Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo

    2004-03-26T23:59:59.000Z

    OAK-B135 Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers. In the nuclear industry, steam generators are often affected by this problem. However, flow-induced vibration is not limited to nuclear power plants, but to any type of heat exchanger used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat exchangers experience flow-induced vibration due to the high velocity flow over the tube banks. Flow-induced vibration in these heat exchangers leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat exchangers. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by a discussion of publications and presentations relevant to the project in Chapter 5, while the conclusions and recommendations for future work are presented in Chapter 6.

  6. Compact microchannel system

    DOE Patents [OSTI]

    Griffiths, Stewart

    2003-09-30T23:59:59.000Z

    The present invention provides compact geometries for the layout of microchannel columns through the use of turns and straight channel segments. These compact geometries permit the use of long separation or reaction columns on a small microchannel substrate or, equivalently, permit columns of a fixed length to occupy a smaller substrate area. The new geometries are based in part on mathematical analyses that provide the minimum turn radius for which column performance in not degraded. In particular, we find that straight channel segments of sufficient length reduce the required minimum turn radius, enabling compact channel layout when turns and straight segments are combined. The compact geometries are obtained by using turns and straight segments in overlapped or nested arrangements to form pleated or coiled columns.

  7. Hydraulic transmissivity and heat exchange efficiency of open fractures: a model based on lowpass filtered apertures

    E-Print Network [OSTI]

    Neuville, Amlie; Schmittbuhl, Jean; 10.1111/j.1365-246X.2011.05126.x

    2011-01-01T23:59:59.000Z

    Natural open joints in rocks commonly present multi-scale self-affine apertures. This geometrical complexity affects fluid transport and heat exchange between the flow- ing fluid and the surrounding rock. In particular, long range correlations of self-affine apertures induce strong channeling of the flow which influences both mass and heat advection. A key question is to find a geometrical model of the complex aperture that describes at best the macroscopic properties (hydraulic conductivity, heat exchange) with the smallest number of parameters. Solving numerically the Stokes and heat equa- tions with a lubrication approximation, we show that a low pass filtering of the aperture geometry provides efficient estimates of the effective hydraulic and thermal properties (apertures). A detailed study of the influence of the bandwidth of the lowpass filtering on these transport properties is also performed. For instance, keeping the information of amplitude only of the largest Fourier length scales allows us to rea...

  8. Stability analysis of direct contact heat exchangers subject to system perturbations. Final report, Task 2

    SciTech Connect (OSTI)

    Jacobs, H.R.

    1985-01-01T23:59:59.000Z

    This report includes a project summary, copies of two papers resulting from the work and the Ph.D. Dissertation of Dr. Mehdi Golafshani entitled, ''Stability of a Direct Contact Heat Exchanger''. Specifically, the work deals with the operational stability of a spray column type heat exchanger subject to disturbances typical of those which can occur for geothermal applications. A computer program was developed to solve the one-dimensional transient two-phase flow problem and it was applied to the design of a spray column. The operation and design of the East Mesa 500kW/sub e/ direct contactor was assessed. It is shown that the heat transfer is governed by the internal resistance of the dispersed phase. In fact, the performance is well-represented by diffusion of heat within the drops. 5 refs.

  9. The Influence of Availability Costs on Optimal Heat Exchanger Size

    E-Print Network [OSTI]

    Witte, L. C.

    3.62 2272.5 2230.2 2691.5 0.1433 110 3.86 2321. 3 2129.6 2740.3 0.4154 145 4.03 2344.5 2066.2 2763.5 0.7005 165 . 4.29 2371. 0 1960.0 2790.0 1. 3978 195 2385.0 4.67 230 2804.0 1813.8 2.795 2370.7 5.24 270 2789.7 1605.2 5.499 The scheme... clearly affects the optimal NTU hat will result. Thus the effect of the s r roundings and function of a particularlheat exchanger on its irreversibility costs is inherently contained in the curves of iq ure 2. The parameter Thi/Tci ranges ftom 1...

  10. Design of chemical reactors of the heat exchanger type

    E-Print Network [OSTI]

    McBeth, Lloyd Theodore

    1956-01-01T23:59:59.000Z

    evaluated at the second f1ow rate. A heat balance on the coolant gives the following differential equation: C t +naU(T - t) = o c ~i? 10 The temperature, t, of the coolant at any position, L, is n' n' given by - naU Ln t -T-(T-t)e w n- i C p c (1... for the increment of tim? /f, , is satisfied. It does not necessarily follow that the differential equation of continuity is satisfied at all times. The integral expression for Q+, is as follows: The time, (t -t)w, c f)f) (14) c 0 6 required...

  11. Geothermal: Sponsored by OSTI -- Chapter 11. Heat Exchangers

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun with Big Sky Learning FunNeuTel2011Programmatic ReportsContactRelated1. Heat

  12. Long-term corrosion measurements in condensing heat exchangers. Topical report, September 1989-January 1993

    SciTech Connect (OSTI)

    Stickford, G.H.; Hindin, B.

    1993-01-31T23:59:59.000Z

    Corrosion of metals used in condensing heat exchangers for gas appliances has been correlated most strongly with the chloride content of the condensate. This study presents results of an experimental examination of the long-term corrosion in metals used in condensing heat exchangers. The objective of this work is to develop a rationale for predicting the performance and expected service life of metals in condensing heat exchangers. Long-term exposure tests were conducted using finned-tube condensing heat exchangers containing tubes of 304L, 3161L, 3171L, Sea-Cure, and 29-4C steel, and aluminum. The natural gas was spiked with R-11 to generate chloride ion levels in the condensate of 3 ppm, 26 ppm, and 225 ppm. The aluminum tubes experienced through-the-wall pitting after 1.5 months at 225 ppm chloride, and after 6 months at 26 ppm chloride. At 3 ppm, most of the tubes exhibited no corrosion. At 225 ppm and 26 ppm, the 300-series stainless steels experienced through-the-wall corrosion within 3 months, but at 3 ppm virtually no corrosion was found. Sea-Cure and 29-4C exhibited the best corrosion resistance with some pitting at 225 ppm but none at 26 ppm and 3 ppm.

  13. When to clean and how to clean biofilms in heat exchangers

    E-Print Network [OSTI]

    Pogiatzis, T.A.; Vassiliadis, V.S.; Mergulho, F.J.; Wilson, D.I.

    2014-07-02T23:59:59.000Z

    in refinery preheat trains. Energy & Fuels. 2009, 23, 1323-37. [4] Lavaja, J.H., Bagajewicz, M.J. On a new MILP model for the planning of heat-exchanger network cleaning. Industrial & Engineering Chemistry Research. 2004, 43, 3924-38. [5] Rodriguez, C., Smith...

  14. Corrosion of Aluminum-fin, Copper-tube Heat Exchange Coils

    E-Print Network [OSTI]

    Field, J. E.

    2002-01-01T23:59:59.000Z

    Over the past several years the HVAC industry has experienced a large increase in instances of leaks in the central portion of aluminum-finned, coppertube heat exchange coils. These leaks are characterized as being very small in size and very high...

  15. Bond Graph Model of a Vertical U-Tube Steam Condenser Coupled with a Heat Exchanger

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    level. Steam condensers are integral part of any nuclear and thermal power plant utilising steam A simulation model for a vertical U-tube steam condenser in which the condensate is stored at the bottom well and thus the bottom well acts as a heat exchanger. The storage of hydraulic and thermal energies

  16. Experimental shellside flow visualization in a shell and tube heat exchanger

    E-Print Network [OSTI]

    Fischer, Matthew Winslow

    1998-01-01T23:59:59.000Z

    information in the shellside flow. A scale-model shell and tube heat exchanger with an outer diameter of 30.5 cm and a length of 61 cm was designed and constructed out of acrylic. Water was utilized as the working fluid and flowrates ranging from 0.32 to 2...

  17. Applying Learnable Evolution Model to Heat Exchanger Design Kenneth A. Kaufman and Ryszard S. Michalski*

    E-Print Network [OSTI]

    Michalski, Ryszard S.

    of the evaporator tubes in the heat exchanger of an air conditioner. This is a very difficult problem because conditioner, refrigerant flows through a loop. It is superheated and placed in contact with cooler outside air conditions, manufacturers of air conditioning systems currently assume in their models average operating

  18. Hybrid heat exchange for the compression capture of CO2 from recirculated flue gas

    SciTech Connect (OSTI)

    Oryshchyn, Danylo B.; Ochs, Thomas L.; Summers, Cathy A.

    2004-01-01T23:59:59.000Z

    An approach proposed for removal of CO2 from flue gas cools and compresses a portion of a recirculated flue-gas stream, condensing its volatile materials for capture. Recirculating the flue gas concentrates SOx, H2O and CO2 while dramatically reducing N2 and NOx, enabling this approach, which uses readily available industrial components. A hybrid system of indirect and direct-contact heat exchange performs heat and mass transfer for pollutant removal and energy recovery. Computer modeling and experimentation combine to investigate the thermodynamics, heat and mass transfer, chemistry and engineering design of this integrated pollutant removal (IPR) system.

  19. Experimental study on corrugated cross-flow air-cooled plate heat exchangers

    SciTech Connect (OSTI)

    Kim, Minsung; Baik, Young-Jin; Park, Seong-Ryong; Ra, Ho-Sang [Solar Thermal and Geothermal Research Center, Korea Institute of Energy Research, Daejeon 305-343 (Korea); Lim, Hyug [Research and Development Center, LHE Co., Ltd., Gimhae 621-874 (Korea)

    2010-11-15T23:59:59.000Z

    Experimental study on cross-flow air-cooled plate heat exchangers (PHEs) was performed. The two prototype PHEs were manufactured in a stack of single-wave plates and double-wave plates in parallel. Cooling air flows through the PHEs in a crosswise direction against internal cooling water. The heat exchanger aims to substitute open-loop cooling towers with closed-loop water circulation, which guarantees cleanliness and compactness. In this study, the prototype PHEs were tested in a laboratory scale experiments. From the tests, double-wave PHE shows approximately 50% enhanced heat transfer performance compared to single-wave PHE. However, double-wave PHE costs 30% additional pressure drop. For commercialization, a wide channel design for air flow would be essential for reliable performance. (author)

  20. Micro-scale heat-exchangers for Joule-Thomson cooling.

    SciTech Connect (OSTI)

    Gross, Andrew John

    2014-01-01T23:59:59.000Z

    This project focused on developing a micro-scale counter flow heat exchangers for Joule-Thomson cooling with the potential for both chip and wafer scale integration. This project is differentiated from previous work by focusing on planar, thin film micromachining instead of bulk materials. A process will be developed for fabricating all the devices mentioned above, allowing for highly integrated micro heat exchangers. The use of thin film dielectrics provides thermal isolation, increasing efficiency of the coolers compared to designs based on bulk materials, and it will allow for wafer-scale fabrication and integration. The process is intended to implement a CFHX as part of a Joule-Thomson cooling system for applications with heat loads less than 1mW. This report presents simulation results and investigation of a fabrication process for such devices.

  1. Interface Exchange as an Indicator for Eddy Heat Transport

    SciTech Connect (OSTI)

    Petersen, Mark R. [Los Alamos National Laboratory; Williams, Sean J. [Los Alamos National Laboratory; Hecht, Matthew W. [Los Alamos National Laboratory; Maltrud, Mathew E. [Los Alamos National Laboratory; Hamann, Bernd [U of California Davis; Patchett, John M. [Los Alamos National Laboratory; Ahrens, James P. [Los Alamos National Laboratory

    2012-06-12T23:59:59.000Z

    The ocean contains many large-scale, long-lived vortices, called mesoscale eddies, that are believed to have a role in the transport and redistribution of salt, heat, and nutrients throughout the ocean. Determining this role, however, has proven to be a challenge, since the mechanics of eddies are only partly understood; a standard definition for these ocean eddies does not exist and, therefore, scientifically meaningful, robust methods for eddy extraction, characterization, tracking and visualization remain a challenge. In order to shed light on the nature and potential roles of eddies, we have combined our previous research on eddy identification and tracking, and have used those approaches as the basis for analysis-driven computational experiments on the nature of eddies. Based on the resulting visualizations of eddy behavior, we have devised a new metric to characterize the transfer of water into and out of eddies across their boundary, and have developed visualization methods for this new metric to provide clues about the role eddies play in the global ocean and, potentially, climate change.

  2. Technology Development Roadmap for the Advanced High Temperature Reactor Secondary Heat Exchanger

    SciTech Connect (OSTI)

    P. Sabharwall; M. McCllar; A. Siahpush; D. Clark; M. Patterson; J. Collins

    2012-09-01T23:59:59.000Z

    This Technology Development Roadmap (TDRM) presents the path forward for deploying large-scale molten salt secondary heat exchangers (MS-SHX) and recognizing the benefits of using molten salt as the heat transport medium for advanced high temperature reactors (AHTR). This TDRM will aid in the development and selection of the required heat exchanger for: power production (the first anticipated process heat application), hydrogen production, steam methane reforming, methanol to gasoline production, or ammonia production. This TDRM (a) establishes the current state of molten salt SHX technology readiness, (b) defines a path forward that systematically and effectively tests this technology to overcome areas of uncertainty, (c) demonstrates the achievement of an appropriate level of maturity prior to construction and plant operation, and (d) identifies issues and prioritizes future work for maturing the state of SHX technology. This study discusses the results of a preliminary design analysis of the SHX and explains the evaluation and selection methodology. An important engineering challenge will be to prevent the molten salt from freezing during normal and off-normal operations because of its high melting temperature (390C for KF ZrF4). The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The need for efficiency, compactness, and safety challenge the capabilities of existing heat exchanger technology. The description of potential heat exchanger configurations or designs (such as printed circuit, spiral or helical coiled, ceramic, plate and fin, and plate type) were covered in an earlier report (Sabharwall et al. 2011). Significant future work, much of which is suggested in this report, is needed before the benefits and full potential of the AHTR can be realized. The execution of this TDRM will focuses research efforts on the near-term qualification, selection, or maturation strategy as detailed in this report. Development of the integration methodology feasibility study, along with research and development (R&D) needs, are ongoing tasks that will be covered in the future reports as work progresses. Section 2 briefly presents the integration of AHTR technology with conventional chemical industrial processes., See Idaho National Laboratory (INL) TEV-1160 (2011) for further details

  3. An Analysis of the Use of Fluidized-Bed Heat Exchangers for Heat Recovery

    E-Print Network [OSTI]

    Vogel, G. J.; Grogan, P. J.

    1980-01-01T23:59:59.000Z

    are presented for a FBWHB system that would produce hot water by recovering part of the heat energy contained in a hot gas....

  4. Investigation of new heat exchanger design performance for solar thermal chemical heat pump.

    E-Print Network [OSTI]

    Cordova, Cordova

    2013-01-01T23:59:59.000Z

    ?? The emergence of Thermally Driven Cooling system has received more attention recently due to its ability to utilize low grade heat from engine, incinerator (more)

  5. SPECIAL ANALYSIS FOR SLIT TRENCH DISPOSAL OF THE REACTOR PROCESS HEAT EXCHANGERS

    SciTech Connect (OSTI)

    Hamm, L.; Collard, L.; Aleman, S.; Gorensek, M.; Butcher, T.

    2012-06-18T23:59:59.000Z

    The Savannah River National Laboratory (SRNL), in response to a request from Solid Waste Management (SWM), conducted a Special Analysis (SA) to evaluate the performance of nineteen heat exchangers that are to be disposed in the E-Area low level waste facility Slit Trench 9 (ST 9). Although these nineteen heat exchangers were never decontaminated, the majority of the radionuclides in the heat exchanger inventory list were determined to be acceptable for burial because they are less than the 'generic' waste form inventory limits given in the 2008 Performance Assessment (PA) (WSRC, 2008). However, as generic waste, the H-3 and C-14 inventories resulted in unacceptable sum-of-fractions (SOFs). Initial scoping analyses performed by SRNL indicated that if alterations were made to certain external nozzles to mitigate various potential leak paths, acceptable SOFs could be achieved through the use of a 'Special' waste form. This SA provides the technical basis for this new 'Special' waste form and provides the inventory limits for H-3 and C-14 for these nineteen heat exchangers such that the nineteen heat exchangers can be disposed in ST 9. This 'Special' waste form is limited to these nineteen heat exchangers in ST 9 and applies for H-3 and C-14, which are designated as H-3X and C-14X, respectively. The SA follows the same methodology used in the 2008 PA and the 2008 SA except for the modeling enhancements noted below. Infiltration rates above the heat exchangers are identical to those used in the 2008 PA; however, flow through the heat exchangers is unique. Because it is unknown exactly how sealed heat exchanger openings will perform and how surface and embedded contaminants will be released, multiple base cases or scenarios were established to investigate a set of performances. Each scenario consists of flow options (based on the performance of sealed openings) and a near-field release of contaminants (based on corrosion and diffusion performance). Two disposal configurations were analyzed where heat exchangers were assumed to be disposed four across and five lengthwise (the 4x5 configuration, with one empty) and three across and seven lengthwise (the 3x7 configuration, with two empty). A large range of conditions was considered. For example, peak well concentrations at the 100-m boundary for H-3 are shown in Figure ES-1 for a wide range of configurations (i.e. release mechanism and degree of sealing options). The maximum contaminant level (MCL) and a 10% SOF goal for H-3 are also shown. The 10% goal was based on an estimated volume fraction that these nineteen heat exchangers would consume in ST 9 and was solely used for scoping purposes to assess disposal feasibility and sealing requirements. Because various line breaks and poor sealing greatly exceeded that 10% goal, the determination was made that mitigating activities were needed, such as protection from line breaks and better sealing. An initial set of scenarios was run to assess the requirements for sealing the heat exchanger openings and the need to ensure that the sealed heat exchangers stayed sealed during transit and disposal operations. After discovering that such mitigating activities were required, additional scenarios were run that included the mitigating activities. Scenarios deemed to have a very low probability of occurrence were excluded from consideration for calculating inventory limits (for example, those scenarios that assumed an instantaneous release of contaminants along with poor sealing). The SA used the most recent K{sub d} values for the C-14 analyses and the most recent Dose Conversion Factors for H-3 and C-14 which have been updated since the 2008 PA was issued. This SA took into account the location and the disposal timing of these heat exchangers. The disposal location is within a small area of the overall Slit Trench unit (about 6% of the total) and is behind a line that is 200 ft from the down-gradient edge of ST 9. The disposal timing is assumed to be after July 1, 2012 (because disposals cannot occur until this document is approved and miti

  6. Three important parts of an integrated plant are reactors, separators and a heat exchanger network (HEN) for heat recovery. Within the process engineering community, much

    E-Print Network [OSTI]

    Skogestad, Sigurd

    exchanger network (HEN) for heat recovery. Within the process engineering community, much attention has beeni ABSTRACT Three important parts of an integrated plant are reactors, separators and a heat and in particular to optimal operation of HENs. The purpose of heat integration is to save energy, but the HEN also

  7. Directly connected heat exchanger tube section and coolant-cooled structure

    DOE Patents [OSTI]

    Chainer, Timothy J; Coico, Patrick A; Graybill, David P; Iyengar, Madhusudan K; Kamath, Vinod; Kochuparambil, Bejoy J; Schmidt, Roger R; Steinke, Mark E

    2014-04-01T23:59:59.000Z

    A cooling apparatus for an electronics rack is provided which includes an air-to-liquid heat exchanger, one or more coolant-cooled structures and a tube. The heat exchanger, which is associated with the electronics rack and disposed to cool air passing through the rack, includes a plurality of distinct, coolant-carrying tube sections, each tube section having a coolant inlet and a coolant outlet, one of which is coupled in fluid communication with a coolant loop to facilitate flow of coolant through the tube section. The coolant-cooled structure(s) is in thermal contact with an electronic component(s) of the rack, and facilitates transfer of heat from the component(s) to the coolant. The tube connects in fluid communication one coolant-cooled structure and the other of the coolant inlet or outlet of the one tube section, and facilitates flow of coolant directly between that coolant-carrying tube section of the heat exchanger and the coolant-cooled structure.

  8. Multiple pollutant removal using the condensing heat exchanger: Phase 1 final report, October 1995--July 1997

    SciTech Connect (OSTI)

    Bailey, R.T.; Jankura, B.J.; Kudlac, G.A.

    1998-06-01T23:59:59.000Z

    The Integrated Flue Gas Treatment (IFGT) system is a new concept whereby a Teflon{reg_sign} covered condensing heat exchanger is adapted to remove certain flue gas constitutents, both particulate and gaseous, while recovering low level heat. Phase 1 includes two experimental tasks. One task dealt principally with the pollutant removal capabilities of the IFGT at a scale of about 1.2MW{sub t}. The other task studied the durability of the Teflon{reg_sign} covering to withstand the rigors of abrasive wear by fly ash emitted as a result of coal combustion. The pollutant removal characteristics of the IFGT system were measured over a wide range of operating conditions. The coals tested included high, medium and low-sulfur coals. The flue gas pollutants studied included ammonia, hydrogen chloride, hydrogen fluoride, particulate, sulfur dioxide, gas phase and particle phase mercury and gas phase and particle phase trace elements. The particulate removal efficiency and size distribution was investigated. These test results demonstrated that the IFGT system is an effective device for both acid gas absorption and fine particulate collection. The durability of the Teflon{reg_sign} covered heat exchanger tubes was studied on a pilot-scale single-stage condensing heat exchanger (CHX{reg_sign}). Data from the test indicate that virtually no decrease in Teflon{reg_sign} thickness was observed for the coating on the first two rows of heat exchanger tubes, even at high inlet particulate loadings. Evidence of wear was present only at the microscopic level, and even then was very minor in severity.

  9. Microchannel apparatus and methods of conducting catalyzed oxidative dehydrogenation

    DOE Patents [OSTI]

    Tonkovich, Anna Lee (Dublin, OH); Yang, Bin (Columbus, OH); Perry, Steven T. (Galloway, OH); Mazanec, Terry (Solon, OH); Arora, Ravi (New Albany, OH); Daly, Francis P. (Delaware, OH); Long, Richard (New Albany, OH); Yuschak, Thomas D. (Lewis Center, OH); Neagle, Paul W. (Westerville, OH); Glass, Amanda (Galloway, OH)

    2011-08-16T23:59:59.000Z

    Methods of oxidative dehydrogenation are described. Surprisingly, Pd and Au alloys of Pt have been discovered to be superior for oxidative dehydrogenation in microchannels. Methods of forming these catalysts via an electroless plating methodology are also described. An apparatus design that minimizes heat transfer to the apparatus' exterior is also described.

  10. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOE Patents [OSTI]

    Berry, Gregory F. (Naperville, IL); Minkov, Vladimir (Skokie, IL); Petrick, Michael (Joliet, IL)

    1988-01-01T23:59:59.000Z

    A magnetohydrodynamic (MHD) power generating system in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  11. Open-cycle magnetohydrodynamic power plant based upon direct-contact closed-loop high-temperature heat exchanger

    DOE Patents [OSTI]

    Berry, G.F.; Minkov, V.; Petrick, M.

    1981-11-02T23:59:59.000Z

    A magnetohydrodynamic (MHD) power generating system is described in which ionized combustion gases with slag and seed are discharged from an MHD combustor and pressurized high temperature inlet air is introduced into the combustor for supporting fuel combustion at high temperatures necessary to ionize the combustion gases, and including a heat exchanger in the form of a continuous loop with a circulating heat transfer liquid such as copper oxide. The heat exchanger has an upper horizontal channel for providing direct contact between the heat transfer liquid and the combustion gases to cool the gases and condense the slag which thereupon floats on the heat transfer liquid and can be removed from the channel, and a lower horizontal channel for providing direct contact between the heat transfer liquid and pressurized air for preheating the inlet air. The system further includes a seed separator downstream of the heat exchanger.

  12. Liquid metal heat exchanger for efficient heating of soils and geologic formations

    DOE Patents [OSTI]

    DeVault, Robert C. (Knoxville, TN) [Knoxville, TN; Wesolowski, David J. (Kingston, TN) [Kingston, TN

    2010-02-23T23:59:59.000Z

    Apparatus for efficient heating of subterranean earth includes a well-casing that has an inner wall and an outer wall. A heater is disposed within the inner wall and is operable within a preselected operating temperature range. A heat transfer metal is disposed within the outer wall and without the inner wall, and is characterized by a melting point temperature lower than the preselected operating temperature range and a boiling point temperature higher than the preselected operating temperature range.

  13. Liquid over-feeding refrigeration system and method with integrated accumulator-expander-heat exchanger

    DOE Patents [OSTI]

    Mei, Viung C. (Oak Ridge, TN); Chen, Fang C. (Knoxville, TN)

    1997-01-01T23:59:59.000Z

    A refrigeration system having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle.

  14. Heat exchangers comprising at least one porous member positioned within a casing

    DOE Patents [OSTI]

    Turner, Terry D. (Idaho Falls, ID); Wilding, Bruce M (Idaho Falls, ID)

    2011-11-22T23:59:59.000Z

    A heat exchanger and associated methods for sublimating solid particles therein, for conveying fluids therethrough, or both. The heat exchanger includes a chamber, and a porous member having a porous wall having pores in communication with the chamber and an interior of the porous member. A first fluid is conveyed into the porous member while a second fluid is conveyed into the porous member through the porous wall. The second fluid may form a positive flow boundary layer along the porous wall to reduce or eliminate substantial contact between the first fluid and the interior of the porous wall. The combined first and second fluids are conveyed out of the porous member. Additionally, the first fluid and the second fluid may each be conveyed into the porous member at different temperatures and may exit the porous member at substantially the same temperature.

  15. Liquid over-feeding refrigeration system and method with integrated accumulator-expander-heat exchanger

    DOE Patents [OSTI]

    Mei, V.C.; Chen, F.C.

    1997-04-22T23:59:59.000Z

    A refrigeration system is described having a vapor compression cycle utilizing a liquid over-feeding operation with an integrated accumulator-expander-heat exchanger. Hot, high-pressure liquid refrigerant from the condenser passes through one or more lengths of capillary tubing substantially immersed in a pool liquid refrigerant in the accumulator-expander-heat exchanger for simultaneously sub-cooling and expanding the liquid refrigerant while vaporizing liquid refrigerant from the pool for the return thereof to the compressor as saturated vapor. The sub-cooling of the expanded liquid provides for the flow of liquid refrigerant into the evaporator for liquid over-feeding the evaporator and thereby increasing the efficiency of the evaporation cycle. 4 figs.

  16. Study of junction flows in louvered fin round tube heat exchangers using the dye injection technique

    SciTech Connect (OSTI)

    Huisseune, H.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); T'Joen, C. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); Department Radiation, Radionuclides and Reactors, Delft University of Technology, Mekelweg 15, 2629 JB Delft (Netherlands); De Jaeger, P. [Department of Flow, Heat and Combustion Mechanics, Ghent University, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium); NV Bekaert SA, Bekaertstraat 2, 8550 Zwevegem (Belgium)

    2010-11-15T23:59:59.000Z

    Detailed studies of junction flows in heat exchangers with an interrupted fin design are rare. However, understanding these flow structures is important for design and optimization purposes, because the thermal hydraulic performance of heat exchangers is strongly related to the flow behaviour. In this study flow visualization experiments were performed in six scaled-up models of a louvered fin round tube heat exchanger. The models have three tube rows in a staggered layout and differ only in their fin spacing and louver angle. A water tunnel was designed and built and the flow visualizations were carried out using dye injection. At low Reynolds numbers the streakline follows the tube contours, while at higher Reynolds numbers a horseshoe vortex is developed ahead of the tubes. The two resulting streamwise vortex legs are destroyed by the downstream louvers (i.e. downstream the turnaround louver), especially at higher Reynolds numbers, smaller fin pitches and larger louver angles. Increasing the fin spacing results in a larger and stronger horseshoe vortex. This illustrates that a reduction of the fin spacing results in a dissipation of vortical motion by mechanical blockage and skin friction. Furthermore it was observed that the vortex strength and number of vortices in the second tube row is larger than in the first tube row. This is due to the thicker boundary layer in the second tube row, and the flow deflection, which is typical for louvered fin heat exchangers. Visualizations at the tube-louver junction showed that in the transition part between the angled louver and the flat landing a vortex is present underneath the louver surface which propagates towards the angled louver. (author)

  17. Eddy current inspection of power plant heat-exchanger tubing in the USA

    SciTech Connect (OSTI)

    Fishkin, P.; Nash, J. [MQS Inspection, Inc., Chicago, IL (United States)

    1995-02-01T23:59:59.000Z

    The latest experience in the eddy current inspection of heat-exchanger tubing by means of ID probes is reported and generalized. The authors demonstrate the feasibility of using modern, general-purpose, digital eddy current flaw detectors equipped with microprocessors, displays, the capability for recording inspection results on paper or magnetic media, sound and visual alarms. The NDE personnel qualification and certification requirements are described.

  18. Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure, Part I: Experimental results

    E-Print Network [OSTI]

    Kandlikar, Satish

    Pool boiling heat transfer enhancement over cylindrical tubes with water at atmospheric pressure online 4 May 2013 Keywords: Pool boiling Heat transfer enhancement Open microchannels Cylindrical tube boiling heat transfer over enhanced cylindrical microchannel test surfaces with water at atmospheric

  19. Advanced Alloys for Compact, High-Efficiency, High-Temperature Heat-Exchangers

    SciTech Connect (OSTI)

    Maziasz, Philip J [ORNL; Pint, Bruce A [ORNL; Shingledecker, John P [ORNL; Evans, Neal D [ORNL; Yamamoto, Yukinori [ORNL; More, Karren Leslie [ORNL; Lara-Curzio, Edgar [ORNL

    2006-01-01T23:59:59.000Z

    Oak Ridge National Laboratory (ORNL) has conducted research and development for several years which has been focused on the behavior and performance improvements of sheets and foils of various alloys for compact heat-exchangers (recuperators) for advanced microturbines. The performance and reliability of such thin sections are challenged at 650-750 C by fine grain size causing excessive creep, and by moisture effects greatly enhancing oxidation attack in exhaust gas environments. Standard 347 stainless steel has been used successfully at or below 600 C, but has suffered from both of these kinds of degradation at 650 C and above. Alloys have been identified which can have very good properties for such heat-exchangers, especially with careful control of microstructure during processing, including alloy 625, HR120 and the new AL20-25+Nb. These alloys, and the mechanistic understanding behind their behavior, are also applicable to achieving the better heat-exchanger technology needed for fuel cells or other high-temperature, clean-energy applications.

  20. A mathematical model for the simulation of closed-loop earth-coupled heat exchangers for a water source heat pump

    E-Print Network [OSTI]

    De Lange, Kevin Jon

    1988-01-01T23:59:59.000Z

    A MATHEMATICAL MODEL FOR THE SIMULATION OF CLOSED-LOOP EARTH-COUPLED HEAT EXCHANGERS FOR A WATER SOURCE HEAT PUMP A Thesis by KEVIN JON DE LANGE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Agricultural Engineering A MATHEMATICAL MODEL FOR THE SIMULATION OF CLOSED-LOOP EARTH-COUPLED HEAT EXCHANGERS FOR A WATER SOURCE HEAT PUMP A Thesis by KEVIN JON DE LANGE...

  1. Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger

    DOE Patents [OSTI]

    Im, Kwan H. (Naperville, IL); Ahluwalia, Rajesh K. (Burr Ridge, IL)

    1994-01-01T23:59:59.000Z

    A radiative heat transfer mechanism in a furnace having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits.

  2. Heat transfer mechanism with thin filaments including ceramic high temperature heat exchanger

    DOE Patents [OSTI]

    Im, K.H.; Ahluwalia, R.K.

    1994-10-18T23:59:59.000Z

    A radiative heat transfer mechanism in a furnace is described having burners through which pulverized coal and air are burned producing combustion gases and contaminants. A plurality of elongated conduits are positioned inside the furnace proximate to the burners generally parallel to the flow of combustion gases in the furnace. A plurality of thin filaments are inside each of the elongated hollow conduits, the filaments having diameters in the range of from about 1 micrometer to about 1,000 micrometers and having an infrared radiation cross-section sufficient to cause the filaments to heat upon exposure to infrared radiation. Blower mechanism is associated with the elongated conduits for limiting the amount of soot and ash which deposit on the conduits to preserve the radiative and convective transfer of heat energy from the combustion gases to the conduits. 7 figs.

  3. Separation process using microchannel technology

    DOE Patents [OSTI]

    Tonkovich, Anna Lee (Dublin, OH); Perry, Steven T. (Galloway, OH); Arora, Ravi (Dublin, OH); Qiu, Dongming (Bothell, WA); Lamont, Michael Jay (Hilliard, OH); Burwell, Deanna (Cleveland Heights, OH); Dritz, Terence Andrew (Worthington, OH); McDaniel, Jeffrey S. (Columbus, OH); Rogers, Jr.; William A. (Marysville, OH); Silva, Laura J. (Dublin, OH); Weidert, Daniel J. (Lewis Center, OH); Simmons, Wayne W. (Dublin, OH); Chadwell, G. Bradley (Reynoldsburg, OH)

    2009-03-24T23:59:59.000Z

    The disclosed invention relates to a process and apparatus for separating a first fluid from a fluid mixture comprising the first fluid. The process comprises: (A) flowing the fluid mixture into a microchannel separator in contact with a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the first fluid is sorbed by the sorption medium, removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing first fluid from the sorption medium and removing desorbed first fluid from the microchannel separator. The process and apparatus are suitable for separating nitrogen or methane from a fluid mixture comprising nitrogen and methane. The process and apparatus may be used for rejecting nitrogen in the upgrading of sub-quality methane.

  4. Emerging Heat Exchanger Technologies for the Mitigation of Fouling in Crude Oil Pre-Heat Trains

    E-Print Network [OSTI]

    Polley, G. T.; Pugh, S. J.; King, D. C.

    Over the last three years ESDU have been working with engineers from oil companies and the companies that serve them in order to produce a guide describing the current state of knowledge on fouling in pre-heat trains and ways in which it can...

  5. Combustion air preheating for refinery heaters using plate-type heat exchangers

    SciTech Connect (OSTI)

    Dinulescu, M.

    1987-01-01T23:59:59.000Z

    Combustion air preheating by recovering heat from combustion gases is a cost effective method of increasing the overall thermal efficiency of the refining and petrochemical processes. This paper presents the advantages of the plate-type air preheaters made of smooth plates without extended surfaces. These exchangers provide a relatively high heat transfer coefficient at a relatively low pressure drop, resulting in a flexible and compact design. The air preheater design can easily be integrated into the heater design. Top mounting with natural draft becomes possible for many applications, eliminating the need for I.D. fan and expensive ductwork. The economical extent of heat recovery function of the fuel fired is presented based on practical experience. The use of porcelain enameled (glass coated) plates and of stainless steel materials allows the operation of the air preheater below the acidic and water dew point. Finally the paper presents the experience of the Canadian refineries and petrochemical plants with plate-type heat exchangers used for combustion air preheating.

  6. Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1

    SciTech Connect (OSTI)

    Gupta, Prabhat Kumar [Raja Ramanna Centre for Advanced Technology (RRCAT), Indore (MP), India; Rabehl, Roger [FNAL

    2014-07-01T23:59:59.000Z

    Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.

  7. High Performance Trays and Heat Exchangers in Heat Pumped Distillation Columns

    E-Print Network [OSTI]

    Wisz, M. W.; Antonelli, R.; Ragi, E. G.

    1981-01-01T23:59:59.000Z

    AND LIQUID now PATHS fOA IltO TltAYS I A number of engineering contractors and 1 operating companies have employed Union Carbide'\\s High Flux and Multiple Downcomer tray technolog~es to improve performance, decrease utilities and I lower operating costs... ? Fi,?'d as nll\\ximum within hf'l~ht n'!:-;tl'ie-tlon. The control scheme for a heat pump can be de signed to be no more complex than a conventional steam/cooling water system which relies on flow and level controllers to set the various column flow...

  8. Light weight and economical exhaust heat exchanger for waste heat recovery

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10IO1OP001 Letter Report:Life-CycleDutyR&DPart of ausing

  9. Laser heating of aqueous samples on a micro-optical-electro-mechanical system

    DOE Patents [OSTI]

    Beer, Neil Reginald; Kennedy, Ian

    2013-02-05T23:59:59.000Z

    A system of heating a sample on a microchip includes the steps of providing a microchannel flow channel in the microchip; positioning the sample within the microchannel flow channel, providing a laser that directs a laser beam onto the sample for heating the sample; providing the microchannel flow channel with a wall section that receives the laser beam and enables the laser beam to pass through wall section of the microchannel flow channel without being appreciably heated by the laser beam; and providing a carrier fluid in the microchannel flow channel that moves the sample in the microchannel flow channel wherein the carrier fluid is not appreciably heated by the laser beam.

  10. Laser heating of aqueous samples on a micro-optical-electro-mechanical system

    DOE Patents [OSTI]

    Beer, Neil Reginald; Kennedy, Ian

    2013-12-17T23:59:59.000Z

    A system of heating a sample on a microchip includes the steps of providing a microchannel flow channel in the microchip; positioning the sample within the microchannel flow channel, providing a laser that directs a laser beam onto the sample for heating the sample; providing the microchannel flow channel with a wall section that receives the laser beam and enables the laser beam to pass through wall section of the microchannel flow channel without being appreciably heated by the laser beam; and providing a carrier fluid in the microchannel flow channel that moves the sample in the microchannel flow channel wherein the carrier fluid is not appreciably heated by the laser beam.

  11. Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant

    SciTech Connect (OSTI)

    Not Available

    2010-12-01T23:59:59.000Z

    The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.

  12. Experimental evaluation of dry/wet air-cooled heat exchangers. Progress report

    SciTech Connect (OSTI)

    Hauser, S.G.; Gruel, R.L.; Huenefeld, J.C.; Eschbach, E.J.; Johnson, B.M.; Kreid, D.K.

    1982-08-01T23:59:59.000Z

    The ultimate goal of this project was to contribute to the development of improved cooling facilities for power plants. Specifically, the objective during FY-81 was to experimentally determine the thermal performance and operating characteristics of an air-cooled heat exchanger surface manufactured by the Unifin Company. The performance of the spiral-wound finned tube surface (Unifin) was compared with two inherently different platefin surfaces (one developed by the Trane Co. and the other developed by the HOETERV Institute) which were previously tested as a part of the same continuing program. Under dry operation the heat transfer per unit frontal area per unit inlet temperature difference (ITD) of the Unifin surface was 10% to 20% below that of the other two surfaces at low fan power levels. At high fan power levels, the performances of the Unifin and Trane surfaces were essentially the same, and 25% higher than the HOETERV surface. The design of the Unifin surface caused a significantly larger air-side pressure drop through the heat exchanger both in dry and deluge operation. Generally higher overall heat transfer coefficients were calculated for the Unifin surface under deluged operation. They ranged from 2.0 to 3.5 Btu/hr-ft/sup 2/-/sup 0/F as compared to less than 2.0 Btu hr-ft/sup 2/-/sup 0/F for the Trane and HOETERV surfaces under similar conditions. The heat transfer enhancement due to the evaporative cooling effect was also measureably higher with the Unifin surface as compared to the Trane surface. This can be primarily attributed to the better wetting characteristics of the Unifin surface. If the thermal performance of the surfaces are compared at equal face velocities, the Unifin surface is as much as 35% better. This method of comparison accounts for the wetting characteristics while neglecting the effect of pressure drop. Alternatively the surfaces when compared at equal pressure drop essentially the same thermal performance.

  13. EXPERIMENTAL AND THEORETICAL INVESTIGATIONS OF NEW POWER CYCLES AND ADVANCED FALLING FILM HEAT EXCHANGERS

    SciTech Connect (OSTI)

    Arsalan Razani; Kwang J. Kim

    2001-12-01T23:59:59.000Z

    The final report for the DOE/UNM grant number DE-FG26-98FT40148 discusses the accomplishments of both the theoretical analysis of advanced power cycles and experimental investigation of advanced falling film heat exchangers. This final report also includes the progress report for the third year (period of October 1, 2000 to September 30, 2001). Four new cycles were studied and two cycles were analyzed in detail based on the second law of thermodynamics. The first cycle uses a triple combined cycle, which consists of a topping cycle (Brayton/gas), an intermediate cycle (Rankine/steam), and a bottoming cycle (Rankine/ammonia). This cycle can produce high efficiency and reduces the irreversibility of the Heat Recovery Steam Generator (HRSC) of conventional combined power cycles. The effect of important system parameters on the irreversibility distribution of all components in the cycle under reasonable practical constraints was evaluated. The second cycle is a combined cycle, which consists of a topping cycle (Brayton/gas) and a bottoming cycle (Rankine/ammonia) with integrated compressor inlet air cooling. This innovative cycle can produce high power and efficiency. This cycle is also analyzed and optimized based on the second the second law to obtain the irreversibility distribution of all components in the cycle. The results of the studies have been published in peer reviewed journals and ASME conference proceeding. Experimental investigation of advanced falling film heat exchangers was conducted to find effective additives for steam condensation. Four additives have been selected and tested in a horizontal tube steam condensation facility. It has been observed that heat transfer additives have been shown to be an effective way to increase the efficiency of conventional tube bundle condenser heat exchangers. This increased condensation rate is due to the creation of a disturbance in the liquid condensate surround the film. The heat transfer through such a film has increased due to the onset of Maranogni convection as well as the population of ''dropwise-like'' condensation increased. The results have been published in peer reviewed journals.

  14. Reformate Cleanup: The Case for Microchannel Architecture

    E-Print Network [OSTI]

    Reformate Cleanup: The Case for Microchannel Architecture DOE Hydrogen and Fuel Cells 2003 Annual for MicrochannelMicrochannel ArchitectureArchitecture DOE Hydrogen and Fuel CellsDOE Hydrogen and Fuel Cells 2003, controls Integrated reformer/fuel cell demonstration at ~2 kWeFY 2002 WGS/PROX catalyst studies

  15. Dry/wet performance of a plate-fin air-cooled heat exchanger with continuous corrugated fins

    SciTech Connect (OSTI)

    Hauser, S.G.; Kreid, D.K.; Johnson, B.M.

    1981-01-01T23:59:59.000Z

    The performance and operating characteristics of a plate-fin heat exchanger in dry/wet or deluge operations was experimentally determined. Development of the deluge heat/mass transfer model continued. The experiments were conducted in a specially-designed wind tunnel at the PNL. Air that was first heated and humidified to specified conditions was circulated at a controlled rate through a 2 ft x 6 ft heat exchanger module. The heat exchanger used in the tests was a wavy surface, plate fin on tube configuration. Hot water was circulated through the tubes at high flow rates to maintain an essentially isothermal condition on the tube side. Deionized water sprayed on the top of the vertically oriented plate fins was collected at the bottom of the core and recirculated. Instrumentation was provided for measurement of flow rates and thermodynamic conditions in the air, in the core circulation water, and in the deluge water. Measurements of the air side pressure drop and heat rejection rate were made as a function of air flow rate, air inlet temperature and humidity, deluge water flow rate, and the core inclination from the vertical. An overall heat transfer coefficient and an effective deluge film convective coefficient was determined. The deluge model, for predicting heat transfer from a wet finned heat exchanger was further developed and refined, and a major extension of the model was formulated that permits simultaneous calculation of both the heat transfer and evaporation rates from the wetted surface. The experiments showed an increase in the heat rejection rate due to wetting, accompanied by a proportional increase in the air side pressure drop. For operation at the same air side pressure drop, the enhancement ratio Q/sub w//Q/sub d/ varied between 2 and 5 for the conditions tested. Thus, the potential enhancement of heat transfer due to wetting can be substantial.

  16. RELAP5-3D Modeling of Heat Transfer Components (Intermediate Heat Exchanger and Helical-Coil Steam Generator) for NGNP Application

    SciTech Connect (OSTI)

    N. A. Anderson; P. Sabharwall

    2014-01-01T23:59:59.000Z

    The Next Generation Nuclear Plant project is aimed at the research and development of a helium-cooled high-temperature gas reactor that could generate both electricity and process heat for the production of hydrogen. The heat from the high-temperature primary loop must be transferred via an intermediate heat exchanger to a secondary loop. Using RELAP5-3D, a model was developed for two of the heat exchanger options a printed-circuit heat exchanger and a helical-coil steam generator. The RELAP5-3D models were used to simulate an exponential decrease in pressure over a 20 second period. The results of this loss of coolant analysis indicate that heat is initially transferred from the primary loop to the secondary loop, but after the decrease in pressure in the primary loop the heat is transferred from the secondary loop to the primary loop. A high-temperature gas reactor model should be developed and connected to the heat transfer component to simulate other transients.

  17. CHARACTERIZATION OF ELEVATED TEMPERATURE PROPERTIES OF HEAT EXCHANGER AND STEAM GENERATOR ALLOYS

    SciTech Connect (OSTI)

    J.K. Wright; L.J. Carroll; C.J. Cabet; T. Lillo; J.K. Benz; J.A. Simpson; A. Chapman; R.N. Wright

    2012-10-01T23:59:59.000Z

    The Next Generation Nuclear Plant project is considering Alloy 800H and Alloy 617 for steam generator and intermediate heat exchangers. It is envisioned that a steam generator would operate with reactor outlet temperatures from 750 to 800 C, while an intermediate heat exchanger for primary to secondary helium would operate up to an outlet temperature of 950 C. Although both alloys are of interest due in part to their technical maturity, a number of specific properties require further characterization for design of nuclear components. Strain rate sensitivity of both alloys has been characterized and is found to be significant above 600 C. Both alloys also exhibit dynamic strain aging, characterized by serrated flow, over a wide range of temperatures and strain rates. High temperature tensile testing of Alloy 617 has been conducted over a range of temperatures. Dynamic strain aging is a concern for these materials since it is observed to result in reduced ductility for many solid solution alloys. Creep, fatigue, and creep-fatigue properties of Alloy 617 have been measured as well, with the goal of determining the influence of the temperature, strain rate and atmosphere on the creep fatigue life of Alloy 617. Elevated temperature properties and implications for codification of the alloys will be described.

  18. Demonstration and Performance Monitoring of Foundation Heat Exchangers (FHX) in Ultra-High Energy Efficient Research Homes

    SciTech Connect (OSTI)

    Im, Piljae [ORNL] [ORNL; Hughes, Patrick [ORNL] [ORNL; Liu, Xiaobing [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    The more widespread use of Ground Source Heat Pump (GSHP) systems has been hindered by their high first cost, which is mainly driven by the cost of the drilling and excavation for installation of ground heat exchangers (GHXs). A new foundation heat exchanger (FHX) technology was proposed to reduce first cost by placing the heat exchanger into the excavations made during the course of construction (e.g., the overcut for the basement and/or foundation and run-outs for water supply and the septic field). Since they reduce or eliminate the need for additional drilling or excavation, foundation heat exchangers have the potential to significantly reduce or eliminate the first cost premium associated with GSHPs. Since December 2009, this FHX technology has been demonstrated in two ultra-high energy efficient new research houses in the Tennessee Valley, and the performance data has been closely monitored as well. This paper introduces the FHX technology with the design, construction and demonstration of the FHX and presents performance monitoring results of the FHX after one year of monitoring. The performance monitoring includes hourly maximum and minimum entering water temperature (EWT) in the FHX compared with the typical design range, temperature difference (i.e., T) across the FHX, and hourly heat transfer rate to/from the surrounding soil.

  19. Design of a continuous fiber ceramic composite heat exchanger for high-temperature, high-pressure applications

    SciTech Connect (OSTI)

    Cho, S.M.; Seltzer, A.H.; Narayanan, T.V. [Foster Wheeler Development Corp., Livingston, NJ (United States); Shah, A.C.; Weddell, J.K. [DuPont Lanxide Composites Inc., Newark, DE (United States)

    1996-12-31T23:59:59.000Z

    A conceptual design of a continuous fiber ceramic composite (CFCC) heat exchanger for high-temperature, high-pressure applications is presented. The CFCC materials under consideration are SiC reinforced with SiC fibers manufactured using the continuous vapor infiltration process and alumina reinforced with SiC or alumina fibers manufactured using the directed metal oxidation process. These composite materials are highly resistant to high-temperature corrosive environment and possess a greater creep strength than metallic materials. Heat exchangers constructed of CFCC material may be utilized for high-temperature, high-pressure applications such as air/gas heaters in advanced energy systems and high-temperature energy recovery systems. This paper presents a design of a gas-to-air CFCC heat exchanger for the high temperature advanced furnace (HITAF) in the high-performance power system (HIPPS). The 1.38 MPa (200 psia) air is heated from 760 C (1,400 F) to 982 C (1,800 F) using the combustion products at 1,650 C (3,000 F). The heat exchanger is of a cross-parallel/counter flow type in which the tube-side air flow makes a combined parallel and counter flow arrangement with a cross-flowing combustion gas in such a way that the maximum CFCC tube temperature will not exceed a 1,260 C (2,300 F) design limit. The main heat transfer mechanism from the external hot gas to the tube-side air is that of gaseous radiation for the first few rows of the tubes, followed by convective heat transfer across the remainder of the tube bundle. The design characteristics of this high-temperature, high-pressure CFCC heat exchanger with supporting thermal, flow, structural, and vibrational analyses are presented in detail in the paper.

  20. Erosion of heat exchanger tubes in fluidized beds. Annual report, 1990

    SciTech Connect (OSTI)

    Johnson, E.K.; Flemmer, R.L.C.

    1991-01-01T23:59:59.000Z

    This final report describes the activities of the 3-year project entitled ``Erosion of Heat Exchanger Tubes In Fluidized Beds.`` which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. {times} 24in. fluidized bed, comparative wear results In a 6in. {times} 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. {times} 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. {times} 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. {times} 24in. bed and the modeling of the tube wear in the 24in. {times} 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.

  1. Direct contact liquid-liquid heat exchanger for solar heated and cooled buildings. Final report, January 1, 1979-May 30, 1980

    SciTech Connect (OSTI)

    Karaki, S.; Brothers, P.

    1980-06-01T23:59:59.000Z

    The technical and economic feasibility of using a direct contact liquid-liquid heat exchanger (DCLLHE) storage unit in a solar heating and cooling system is established. Experimental performance data were obtained from the CSU Solar House I using a DCLLHE for both heating and cooling functions. A simulation model for the system was developed. The model was validated using the experimental data and applied in five different climatic regions of the country for a complete year. The life-cycle cost of the system was estimated for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger. It is concluded that while thare is a performance advantage with a DCLLHE system over a conventional solar system, the advantage is not sufficiently large to overcome slightly higher capital and operating costs for the DCLLHE system.

  2. Direct contact liquid-liquid heat exchanger for solar-heated and -cooled buildings. Final report, January 1, 1979-May 30, 1980

    SciTech Connect (OSTI)

    Karaki, S.; Brothers, P.

    1980-06-01T23:59:59.000Z

    The procedure used was to obtain experimental performance data from a solar system using a DCLLHE for both heating and cooling functions, develop a simulation model for the system, validate the model using the data, apply the model in five different climatic regions of the country for a complete year, and estimate the life-cycle cost of the system for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger.

  3. Experimental and numerical investigation on air-side performance of fin-and-tube heat exchangers with various fin patterns

    SciTech Connect (OSTI)

    Tang, L.H.; Zeng, M.; Wang, Q.W. [State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

    2009-07-15T23:59:59.000Z

    Air-side heat transfer and friction characteristics of five kinds of fin-and-tube heat exchangers, with the number of tube rows (N = 12) and the diameter of tubes (D{sub o} = 18 mm), have been experimentally investigated. The test samples consist of five types of fin configurations: crimped spiral fin, plain fin, slit fin, fin with delta-wing longitudinal vortex generators (VGs) and mixed fin with front 6-row vortex-generator fin and rear 6-row slit fin. The heat transfer and friction factor correlations for different types of heat exchangers were obtained with the Reynolds numbers ranging from 4000 to 10000. It was found that crimped spiral fin provides higher heat transfer and pressure drop than the other four fins. The air-side performance of heat exchangers with the above five fins has been evaluated under three sets of criteria and it was shown that the heat exchanger with mixed fin (front vortex-generator fin and rear slit fin) has better performance than that with fin with delta-wing vortex generators, and the slit fin offers best heat transfer performance at high Reynolds numbers. Based on the correlations of numerical data, Genetic Algorithm optimization was carried out, and the optimization results indicated that the increase of VG attack angle or length, or decrease of VG height may enhance the performance of vortex-generator fin. The heat transfer performances for optimized vortex-generator fin and slit fin at hand have been compared with numerical method. (author)

  4. Development of nondestructive evaluation techniques for high-temperature ceramic heat exchanger components. Tenth quarterly report, January-March 1980

    SciTech Connect (OSTI)

    Kupperman, D.S.; Yuhas, D.; Caines, M.J.

    1980-04-01T23:59:59.000Z

    The effectiveness of several conventional and unconventional NDE techniques for specific high-temperature ceramic components was determined. Techniques under study at ANL include dye-enhanced radiography, acoustic microscopy, conventional ultrasonic testing, acoustic-emission detection, acoustic impact testing, holography, interferometry, infrared scanning, internal friction measurements, and overload proof testing. The current effort involves SiC heat-exchanger tubes; previous ceramic NDE efforts at ANL have involved silicon-nitride gas-turbine rotors. Recent results on inspection of SiC heat-exchanger tubing by means of ultrasonic acoustic microscopy techniques and efforts initiated and planned for NDE of ceramic joints are discussed.

  5. Multiple pollutant removal using the condensing heat exchanger. Task 2, Pilot scale IFGT testing

    SciTech Connect (OSTI)

    Jankura, B.J.

    1996-01-01T23:59:59.000Z

    The purpose of Task 2 (IFGT Pilot-Scale Tests at the B&W Alliance Research Center) is to evaluate the emission reduction performance of the Integrated flue Gas Treatment (IFGT) process for coal-fired applications. The IFGT system is a two-stage condensing heat exchanger that captures multiple pollutants - while recovering waste heat. The IFGT technology offers the potential of a addressing the emission of SO{sub 2} and particulate from electric utilities currently regulated under the Phase I and Phase II requirements defined in Title IV, and many of the air pollutants that will soon be regulated under Title III of the Clean Air Act. The performance data will be obtained at pilot-scale conditions similar to full-scale operating systems. The task 2 IFGT tests have been designed to investigate several aspects of IFGT process conditions at a broader range of variable than would be feasible at a larger scale facility. The performance parameters that will be investigated are as follows: SO{sub 2} removal; particulate removal; removal of mercury and other heavy metals; NO{sub x} removal; HF and HCl removal; NH{sub 3} removal; ammonia-sulfur compounds generation; and steam injection for particle removal. For all of the pollutant removal tests, removal efficiency will be based on measurements at the inlet and outlet of the IFGT facility. Heat recovery measurements will also be made during these tests to demonstrate the heat recovery provided by the IFGT technology. This report provides the Final Test Plan for the first coal tested in the Task 2 pilot-scale IFGT tests.

  6. Advanced Heat Exchanger Development for Molten Salts in Nuclear and Non Nuclear Systems

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sabharwall, Piyush; Clark, Denis; Sridharan, Kumar; Zheng, Guiqiu; Anderson, Mark

    2014-12-01T23:59:59.000Z

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.

  7. Advanced Heat Exchanger Development for Molten Salts in Nuclear and Non Nuclear Systems

    SciTech Connect (OSTI)

    Piyush Sabharwall; Denis Clark; Kumar Sridharan; Guiqiu Zheng; Mark Anderson

    2014-10-01T23:59:59.000Z

    This study addresses present work concerned with advanced heat exchanger development for molten salt in nuclear and non nuclear thermal systems. The molten salt systems discussed herein use alloys, such as Hastelloy N and 242, which show corrosion resistance to molten salt at nominal operating temperatures up to 700C. These alloys were diffusion welded, and the corresponding information is presented. Test specimens were prepared for exposing diffusion welds to molten salt environments. Hastelloy N and 242 were found to be weldable by diffusion welding, with ultimate tensile strengths about 90% of base metal values. Both diffusion welds and sheet material in Hastelloy N were corrosion tested in?58 mol% KF and 42 mol% ZrF4 at 650, 700, and 850C for 200, 500, and 1,000 hours. Corrosion rates found were similar between welded and nonwelded materials, typically <10 mils per year. For materials of construction, nickel and alloys with dense nickel coatings are effectively inert to corrosion in fluorides, but not so in chlorides. Hence, additional testing of selected alloys for resistance to intergranular corrosion is needed, as is a determination of corrosion rate as a function of contaminant type and alloy composition with respect to chromium and carbon to better define the optimal chromium and carbon composition, independent of galvanic or differential solubility effects. Also presented is the division of the nuclear reactor and high temperature components per ASME standards, along with design requirements for a subcritical Rankine power cycle heat exchanger that has to overcome pressure difference of about 17 MPa.

  8. Design and Analysis of High-Performance Air-Cooled Heat Exchanger with an Integrated Capillary-Pumped Loop Heat Pipe

    E-Print Network [OSTI]

    McCarthy, Matthew

    We report the design and analysis of a high-power air-cooled heat exchanger capable of dissipating over 1000 W with 33 W of input electrical power and an overall thermal resistance of less than 0.05 K/W. The novelty of the ...

  9. OPTIMIZATION OF INTERNAL HEAT EXCHANGERS FOR HYDROGEN STORAGE TANKS UTILIZING METAL HYDRIDES

    SciTech Connect (OSTI)

    Garrison, S.; Tamburello, D.; Hardy, B.; Anton, D.; Gorbounov, M.; Cognale, C.; van Hassel, B.; Mosher, D.

    2011-07-14T23:59:59.000Z

    Two detailed, unit-cell models, a transverse fin design and a longitudinal fin design, of a combined hydride bed and heat exchanger are developed in COMSOL{reg_sign} Multiphysics incorporating and accounting for heat transfer and reaction kinetic limitations. MatLab{reg_sign} scripts for autonomous model generation are developed and incorporated into (1) a grid-based and (2) a systematic optimization routine based on the Nelder-Mead downhill simplex method to determine the geometrical parameters that lead to the optimal structure for each fin design that maximizes the hydrogen stored within the hydride. The optimal designs for both the transverse and longitudinal fin designs point toward closely-spaced, small cooling fluid tubes. Under the hydrogen feed conditions studied (50 bar), a 25 times improvement or better in the hydrogen storage kinetics will be required to simultaneously meet the Department of Energy technical targets for gravimetric capacity and fill time. These models and methodology can be rapidly applied to other hydrogen storage materials, such as other metal hydrides or to cryoadsorbents, in future work.

  10. Measurement of laser heating in spin exchange optical pumping by NMR diffusion sensitization gradients

    SciTech Connect (OSTI)

    Parnell, Steven R.; Deppe, Martin H.; Ajraoui, Salma; Parra-Robles, Juan; Wild, Jim M. [Unit of Academic Radiology, University of Sheffield, Royal Hallamshire Hospital, Glossop Road, Sheffield, S10 2JF (United Kingdom); Boag, Stephen [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

    2010-05-15T23:59:59.000Z

    This paper details pulsed gradient NMR measurements of the {sup 3}He diffusion coefficient in sealed cells during spin exchange optical pumping. The potential of ultra low field magnetic resonance imgaing (MRI) and NMR for noninvasive measurement of cell pressure is demonstrated. Diffusion sensitization gradients allow measurement of the {sup 3}He diffusion coefficient from which the pressure and/or temperature of the gas can be determined during optical pumping. The pressure measurements were compared with neutron time of flight transmission measurements. Good agreement was observed between the temperature/pressure measurements and predictions based on Chapman-Enskog theory. The technique had sufficient sensitivity to observe the diffusion coefficient increasing with temperature in a sealed cell. With this method, evidence for laser heating of the {sup 3}He during optical pumping was found. The results show that NMR diffusion measurements allow noninvasive measurement of the cell temperature and/or pressure in an optical pumping setup. The method can be expanded using MRI to probe the spatial distribution of the diffusion coefficient. These techniques can be applied to the further investigation of polarization limiting effects such as laser heating.

  11. Solid State Joining of High Temperature Alloy Tubes for USC and Heat-Exchanger Systems

    SciTech Connect (OSTI)

    Bimal Kad

    2011-12-31T23:59:59.000Z

    The principal objective of this project was to develop materials enabling joining technologies for use in forward looking heat-exchanger fabrication in Brayton cycle HIPPS, IGCC, FutureGen concepts capable of operating at temperatures in excess of 1000{degree}C as well as conventional technology upgrades via Ultra Super-Critical (USC) Rankine-cycle boilers capable of operating at 760{degree}C (1400F)/38.5MPa (5500psi) steam, while still using coal as the principal fossil fuel. The underlying mission in Rankine, Brayton or Brayton-Rankine, or IGCC combined cycle heat engine is a steady quest to improving operating efficiency while mitigating global environmental concerns. There has been a progressive move to higher overall cycle efficiencies, and in the case of fossil fuels this has accelerated recently in part because of concerns about greenhouse gas emissions, notably CO{sub 2}. For a heat engine, the overall efficiency is closely related to the difference between the highest temperature in the cycle and the lowest temperature. In most cases, efficiency gains are prompted by an increase in the high temperature, and this in turn has led to increasing demands on the materials of construction used in the high temperature end of the systems. Our migration to new advanced Ni-base and Oxide Dispersion Strengthened (ODS) alloys poses significant fabrication challenges, as these materials are not readily weldable or the weld performs poorly in the high temperature creep regime. Thus the joining challenge is two-fold to a) devise appropriate joining methodologies for similar/dissimilar Ni-base and ODS alloys while b) preserving the near baseline creep performance in the welded region. Our program focus is on solid state joining of similar and dissimilar metals/alloys for heat exchanger components currently under consideration for the USC, HIPPS and IGCC power systems. The emphasis is to manipulate the joining methods and variables available to optimize joint creep performance compared to the base material creep performance. Similar and dissimilar butt joints were fabricated of MA956, IN740 alloys and using inertia welding techniques. We evaluated joining process details and heat treatments and its overall effect on creep response. Fixed and incrementally accelerated temperature creep tests were performed for similar and dissimilar joints and such incremental creep life data is compiled and reported. Long term MA956-MA556 joint tests indicate a firm 2Ksi creep stress threshold performance at 850{degree}C with a maximum exposure of over 9725 hours recorded in the current program. A Larsen Miller Parameter (LMP) of 48.50 for a 2Ksi test at 850{degree}C was further corroborated with tests at 2Ksi stress at 900{degree}C yielding a LMP=48.80. Despite this threshold the joints exhibit immense temperature sensitivity and fail promptly when test temperature raised above 900{degree}C. In comparison the performance of dissimilar joints was inferior, perhaps dictated by the creep characteristics of the mating nickel-base alloys. We describe a parametric window of joint development, and post weld heat treatment (PWHT) in dissimilar joints with solid solution (IN601, IN617) and precipitate strengthened (IN740) materials. Some concerns are evident regarding the diffusion of aluminum in dissimilar joints during high temperature recrystallization treatments. It is noted that aggressive treatments rapidly deplete the corrosion protecting aluminum reservoir in the vicinity of the joint interface. Subsequently, the impact of varying PWHT has been evaluated in the context on ensuing creep performance.

  12. Study of Frost Growth on Heat Exchangers Used as Outdoor Coils in Air Source Heat Pump Systems.

    E-Print Network [OSTI]

    Padhmanabhan, Sankaranarayanan K.

    2011-01-01T23:59:59.000Z

    ??During winter heating operation, the outdoor coil of a heat pump acts as an evaporator and when the ambient temperature is near freezing, the moisture (more)

  13. Next Generation Nuclear Plant Intermediate Heat Exchanger Materials Research and Development Plan (PLN-2804)

    SciTech Connect (OSTI)

    J. K. Wright

    2008-04-01T23:59:59.000Z

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Todays high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760C. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for application in heat exchangers and core internals for the NGNP. The primary candidates are Inconel 617, Haynes 230, Incoloy 800H and Hastelloy XR. Based on the technical maturity, availability in required product forms, experience base, and high temperature mechanical properties all of the vendor pre-conceptual design studies have specified Alloy 617 as the material of choice for heat exchangers. Also a draft code case for Alloy 617 was developed previously. Although action was suspended before the code case was accepted by ASME, this draft code case provides a significant head start for achieving codification of the material. Similarly, Alloy 800H is the material of choice for control rod sleeves. In addition to the above listed considerations, Alloy 800H is already listed in the nuclear section of the ASME Code; although the maximum use temperature and time need to be increased.

  14. Heat exchanges in fast, high-performance liquid chromatography. A complete thermodynamic study

    SciTech Connect (OSTI)

    Gritti, Fabrice [University of Tennessee, Knoxville (UTK); Guiochon, Georges A [ORNL

    2008-01-01T23:59:59.000Z

    The successive physical transformations of the mobile phase that take place in very high pressure liquid chromatography were studied based on the formalism of classical thermodynamics. The eluent is initially under atmospheric pressure (P{sup 0}) and at ambient temperature (T{sub ext}). In a first step, it is compressed to a high pressure (P{sub max} of the order of 1 kbar) in the pump heads of the chromatograph. In a second step, the pressurized eluent is transferred to the inlet of the chromatographic column, along which, in a third step, it is decompressed to atmospheric pressure. Both the compression and the decompression of the fluid were considered to take place under conditions that can be either adiabatic or nonadiabatic and either reversible or irreversible. Applications of the first and second principles of thermodynamics allow the determination of the heat and energy exchanged between the eluent and the external surroundings during each transformation. Experimental data were acquired using acetonitrile as the mobile phase. The true state equation, {rho}(P, T), of liquid acetonitrile was used in the theoretical calculations. A series of four different flow rates (0.55, 0.85, 1.15, and 1.45 mL/min, corresponding to inlet pressures of 357.2, 559.5, 765.1, and 972.9 bar, respectively), were applied to a 2.1 x 100 mm column packed with 1.7-{micro}m bridged ethane-silicon hybrid particles. Thermocouples were used to measure the eluent temperature before and after its passage through the column. These data provide estimates of the variation of the internal energy of the eluent. The heat lost through the external wall of the column during the eluent decompression was estimated by measuring the surface temperature of the column tube under steady state. Both the compression and the decompression of acetonitrile were found to be nonadiabatic and irreversible transformations. The results showed that, during the eluent decompression, the heat released by the friction forces serves four different purposes: (1) it increases the eluent entropy at constant temperature (for 35%); (2) it increases the temperature of the eluent (for 5%); (3) it provides heat to the laboratory atmosphere (for 5%); and (4) it provides some work inside the column (for 5%). This quantitative heat balance description accounts well for the actual performance of the new, very high pressure liquid chromatographic technique.

  15. Microchannel High-Temperature Recuperator for Fuel Cell Systems...

    Broader source: Energy.gov (indexed) [DOE]

    Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2011 Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2011 FuelCell...

  16. Microchannel High-Temperature Recuperator for Fuel Cell Systems...

    Energy Savers [EERE]

    Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2014 Microchannel High-Temperature Recuperator for Fuel Cell Systems - Fact Sheet, 2014 FuelCell...

  17. Hybrid slab-microchannel gel electrophoresis system

    DOE Patents [OSTI]

    Balch, Joseph W. (Livermore, CA); Carrano, Anthony V. (Livermore, CA); Davidson, James C. (Livermore, CA); Koo, Jackson C. (San Ramon, CA)

    1998-01-01T23:59:59.000Z

    A hybrid slab-microchannel gel electrophoresis system. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate.

  18. E-Print Network 3.0 - absorption heat exchange Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Center MOTIVATION ABSORPTION HEAT PUMP COMBINED CARNOT CYCLES... HEAT-DRIVEN HEAT PUMPS EXERGY DESTRUCTION IN ABSORPTION CYCLE PROCESSES ZERO-ORDER ABSORPTION...

  19. Hydraulic transmissivity and heat exchanges: aperture lowpass filtering model 1 Natural open joints in rocks commonly present multi-scale self-affine apertures. This

    E-Print Network [OSTI]

    Paris-Sud XI, Universit de

    Hydraulic transmissivity and heat exchanges: aperture lowpass filtering model 1 SUMMARY Natural aperture that describes at best the macroscopic properties (hydraulic conductivity, heat exchange of the effective hydraulic and thermal properties (apertures). A detailed study of the influence of the bandwidth

  20. Comparison between a spray column and a sieve tray column operating as liquid-liquid heat exchangers

    SciTech Connect (OSTI)

    Keller, A.; Jacobs, H.R.; Boehm, R.F.

    1980-12-01T23:59:59.000Z

    The performance of a spray column and a sieve tray column was compared as a liquid-liquid heat exchanger. In carrying out these studies a 15.2 cm (6.0 in.) diameter column, 183 cm (6.0 ft) tall was utilized. The performance of the spray column as a heat exchanger was shown to correlate with the model of Letan-Kehat which has as a basis that the heat transfer is dominated by the wakeshedding characteristics of the drops over much of the column length. This model defines several hydrodynamic zones along the column of which the wake formation zone at the bottom appears to have the most efficient heat transfer. The column was also operated with four perforated plates spaced two column diameters apart in order to take advantage of the wake formation zone heat transfer. The plates induce coalescence of the dispersed phase and reformation of the drops, and thus cause a repetition of the wake formation zone. It is shown that the overall volumetric heat transfer coefficient in a perforated plate column is increased by a minimum of eleven percent over that in a spray column. A hydrodynamic model that predicts the performance of a perforated plate column is suggested.

  1. Wetting and lubricating film instabilities in microchannels

    E-Print Network [OSTI]

    Cubaud, Thomas

    , and silicone oils . Dynamic wetting transitions: a pearl flow thick lubricating film , b spider flow thinWetting and lubricating film instabilities in microchannels Thomas Cubaud Department of Mechanical of partially wetting threads in planar microchannels of height h=100 or 250 m fluids: ethanol, mineral oils

  2. Prediction and measurement of pitting damage functions for condensing heat exchangers

    SciTech Connect (OSTI)

    Macdonald, D.D.; Liu, C.; Urquidi-Macdonald, M. (Pennsylvania State Univ., University Park, PA (United States). Center for Advanced Materials); Stickford, G.H.; Hindin, B.; Agrawal, A.K. (Battelle Columbus Labs., Columbus, OH (United States)); Krist, K. (Gas Research Inst., Chicago, IL (United States))

    1994-10-01T23:59:59.000Z

    Pitting corrosion is a form of localized attack resulting in rapid penetration into a metal substrate. It is one of the most destructive and insidious forms of corrosion that occurs in industrial systems. Traditionally, the damage function (i.e., the number of pits vs the pit depth) is measured experimentally, and the development of damage has been described using empirical models. In general, the empirical models are successful because the distribution functions employed display great mathematical flexibility, but they require a significant database to achieve reliability. In fact, they really are successful only when the answer is known in advance. In this study, a deterministic method was developed to predict localized corrosion damage functions for condensing heat exchangers. The method incorporated calculations for the composition of the condensed environment and the electrochemical corrosion potential (E[sub corr]) of the alloy and included mechanistic treatments of pit nucleation and growth. The roles of important environmental parameters such as chloride concentration ([Cl[sup [minus

  3. Standard practice for in situ examination of ferromagnetic Heat-Exchanger tubes using remote field testing

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2010-01-01T23:59:59.000Z

    1.1 This practice describes procedures to be followed during remote field examination of installed ferromagnetic heat-exchanger tubing for baseline and service-induced discontinuities. 1.2 This practice is intended for use on ferromagnetic tubes with outside diameters from 0.500 to 2.000 in. [12.70 to 50.80 mm], with wall thicknesses in the range from 0.028 to 0.134 in. [0.71 to 3.40 mm]. 1.3 This practice does not establish tube acceptance criteria; the tube acceptance criteria must be specified by the using parties. 1.4 UnitsThe values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this practice to establ...

  4. Continuous-wave radar to detect defects within heat exchangers and steam generator tubes.

    SciTech Connect (OSTI)

    Nassersharif, Bahram (New Mexico State University, Las Cruces, NM); Caffey, Thurlow Washburn Howell; Jedlicka, Russell P. (New Mexico State University, Las Cruces, NM); Garcia, Gabe V. (New Mexico State University, Las Cruces, NM); Rochau, Gary Eugene

    2003-01-01T23:59:59.000Z

    A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The experimental program resulted in a completed product development schedule and the design of an experimental apparatus for studying handling of the probe and data acquisition. These tests were completed as far as the prototypical probe performance allowed. The prototype probe design did not have sufficient sensitivity to detect a defect signal using the defined radar technique and did not allow successful completion of all of the project milestones. The best results from the prototype probe could not detect a tube defect using the radar principle. Though a more precision probe may be possible, the cost of design and construction was beyond the scope of the project. This report describes the probe development and the status of the design at the termination of the project.

  5. HIGH-TEMPERATURE HEAT EXCHANGER TESTING IN A PILOT-SCALE SLAGGING FURNACE SYSTEM

    SciTech Connect (OSTI)

    Michael E. Collings; Bruce A. Dockter; Douglas R. Hajicek; Ann K. Henderson; John P. Hurley; Patty L. Kleven; Greg F. Weber

    1999-12-01T23:59:59.000Z

    The University of North Dakota Energy & Environmental Research Center (EERC), in partnership with United Technologies Research Center (UTRC) under a U.S. Department of Energy (DOE) contract, has designed, constructed, and operated a 3.0-million Btu/hr (3.2 x 10{sup 6} kJ/hr) slagging furnace system (SFS). Successful operation has demonstrated that the SFS meets design objectives and is well suited for testing very high-temperature heat exchanger concepts. Test results have shown that a high-temperature radiant air heater (RAH) panel designed and constructed by UTRC and used in the SFS can produce a 2000 F (1094 C) process air stream. To support the pilot-scale work, the EERC has also constructed laboratory- and bench-scale equipment which was used to determine the corrosion resistance of refractory and structural materials and develop methods to improve corrosion resistance. DOE projects that from 1995 to 2015, worldwide use of electricity will double to approach 20 trillion kilowatt hours. This growth comes during a time of concern over global warming, thought by many policy makers to be caused primarily by increases from coal-fired boilers in carbon dioxide (CO{sub 2}) emissions through the use of fossil fuels. Assuming limits on CO{sub 2} emissions from coal-fired boilers are imposed in the future, the most economical CO{sub 2} mitigation option may be efficiency improvements. Unless efficiency improvements are made in coal-fired power plants, utilities may be forced to turn to more expensive fuels or buy CO{sub 2} credits. One way to improve the efficiency of a coal-fired power plant is to use a combined cycle involving a typical steam cycle along with an indirectly fired turbine cycle using very high-temperature but low-pressure air as the working fluid. At the heart of an indirectly fired turbine combined-cycle power system are very high-temperature heat exchangers that can produce clean air at up to 2600 F (1427 C) and 250 psi (17 bar) to turn an aeroderivative turbine. The overall system design can be very similar to that of a typical pulverized coal-fired boiler system, except that ceramics and alloys are used to carry the very high-temperature air rather than steam. This design makes the combined-cycle system especially suitable as a boiler-repowering technology. With the use of a gas-fired duct heater, efficiencies of 55% can be achieved, leading to reductions in CO{sub 2} emissions of 40% as compared to today's coal-fired systems. On the basis of work completed to date, the high-temperature advanced furnace (HITAF) concept appears to offer a higher-efficiency technology option for coal-fired power generation systems than conventional pulverized coal firing. Concept analyses have demonstrated the ability to achieve program objectives for emissions (10% of New Source Performance Standards, i.e., 0.003 lb/MMBtu of particulate), efficiency (47%-55%), and cost of electricity (10%-25% below today's cost). Higher-efficiency technology options for new plants as well as repowering are important to the power generation industry in order to conserve valuable fossil fuel resources, reduce the quantity of pollutants (air and water) and solid wastes generated per MW, and reduce the cost of power production in a deregulated industry. Possibly more important than their potential application in a new high-temperature power system, the RAH panel and convective air heater tube bank are potential retrofit technology options for existing coal-fired boilers to improve plant efficiencies. Therefore, further development of these process air-based high-temperature heat exchangers and their potential for commercial application is directly applicable to the development of enabling technologies in support of the Vision 21 program objectives. The objective of the work documented in this report was to improve the performance of the UTRC high-temperature heat exchanger, demonstrate the fuel flexibility of the slagging combustor, and test methods for reducing corrosion of brick and castable refractory in such combustion environments. Specif

  6. Heat exchanger temperature response for duty-cycle transients in the NGNP/HTE.

    SciTech Connect (OSTI)

    Vilim, R. B.; Nuclear Engineering Division

    2009-03-12T23:59:59.000Z

    Control system studies were performed for the Next Generation Nuclear Plant (NGNP) interfaced to the High Temperature Electrolysis (HTE) plant. Temperature change and associated thermal stresses are important factors in determining plant lifetime. In the NGNP the design objective of a 40 year lifetime for the Intermediate Heat Exchanger (IHX) in particular is seen as a challenge. A control system was designed to minimize temperature changes in the IHX and more generally at all high-temperature locations in the plant for duty-cycle transients. In the NGNP this includes structures at the reactor outlet and at the inlet to the turbine. This problem was approached by identifying those high-level factors that determine temperature rates of change. First are the set of duty cycle transients over which the control engineer has little control but which none-the-less must be addressed. Second is the partitioning of the temperature response into a quasi-static component and a transient component. These two components are largely independent of each other and when addressed as such greater understanding of temperature change mechanisms and how to deal with them is achieved. Third is the manner in which energy and mass flow rates are managed. Generally one aims for a temperature distribution that minimizes spatial non-uniformity of thermal expansion in a component with time. This is can be achieved by maintaining a fixed spatial temperature distribution in a component during transients. A general rule of thumb for heat exchangers is to maintain flow rate proportional to thermal power. Additionally the product of instantaneous flow rate and heat capacity should be maintained the same on both sides of the heat exchanger. Fourth inherent mechanisms for stable behavior should not be compromised by active controllers that can introduce new feedback paths and potentially create under-damped response. Applications of these principles to the development of a plant control strategy for the reference NGNP/HTE plant can be found in the body of this report. The outcome is an integrated plant/control system design. The following conclusions are drawn from the analysis: (1) The plant load schedule can be managed to maintain near-constant hot side temperatures over the load range in both the nuclear and chemical plant. (2) The reactor open-loop response is inherently stable resulting mainly from a large Doppler temperature coefficient compared to the other reactivity temperature feedbacks. (3) The typical controller used to manage reactor power production to maintain reactor outlet temperature at a setpoint introduces a feedback path that tends to destabilize reactor power production in the NGNP. (4) A primary loop flow controller that forces primary flow to track PCU flow rate is effective in minimizing spatial temperature differentials within the IHX. (5) Inventory control in both the primary and PCU system during ramp load change transients is an effective means of maintaining high NGNP thermal efficiency while at reduced electric load. (6) Turbine bypass control is an effective means for responding to step changes in generator load when equipment capacity limitations prevent inventory control from being effective. (7) Turbine bypass control is effective in limiting PCU shaft over speed for the loss of generator load upset event. (8) The proposed control strategy is effective in limiting time variation of the differential spatial temperature distribution in the IHX during transients. Essentially the IHX can be made to behave in a manner where each point in the IHX experiences approximately the same temperature rate of change during a transient. (9) The stability of the closed-loop Brayton cycle was found to be sensitive to where one operates on the turbo-machine performance maps. There are competing interests: more stable operation means operating on the curves at points that reduce overall cycle efficiency. Future work should address in greater detail elements that came to light in the course of this work. Specifically: (1) A stability analysi

  7. Functional Integral approach to time-dependent heat exchange in open quantum systems: general method and applications

    E-Print Network [OSTI]

    M. Carrega; P. Solinas; A. Braggio; M. Sassetti; U. Weiss

    2014-12-22T23:59:59.000Z

    We establish the path integral approach for the time-dependent heat exchange of an externally driven quantum system coupled to a thermal reservoir. We derive the relevant influence functional and present an exact formal expression for the moment generating functional which carries all statistical properties of the heat exchange process for general linear dissipation. The general method is applied to the time-dependent average heat transfer in the dissipative two-state system. We show that the heat can be written as a convolution integral which involves the population and coherence correlation functions of the two-state system and additional correlations due to a polarization of the reservoir. The corresponding expression can be solved in the weak-damping limit both for white noise and for quantum mechanical coloured noise. The implications of pure quantum effects are discussed. Altogether a complete description of the dynamics of the average heat transfer ranging from the classical regime down to zero temperature is achieved.

  8. Numerical simulation of intermediate heat exchanger of the liquid metal fast breeder reactor using COMMIX-1B

    E-Print Network [OSTI]

    Saleh, Habeeb H.

    2012-06-07T23:59:59.000Z

    Sodium Flow Through FFTF Reactor Vessel 28 COLD LEG ISOLATION VALVE IIGG SELLDWS SEAL' HOT LEG ISOLATION VALVE QS" I t ?A OUTLET ' L'. : '. i NOZZLE '. : PESSARY~ PUMP IHX INLET NOZZLE CHECK VALVE SELLDWS SEAL' GRAVED MONITOR HOT LEG...NUMERICAL SIMULATION OF INTERMEDIATE HEAT EXCHANGER OF THE LIQUID METAL FAST BREEDER REACTOR USING COMMIX-1B A Thesis by HABEEB H. SALEH Submitted to the Office of Graduate Studies of Texas A@M University in partial fulfillment...

  9. Experimental Evaluation of a Pt-based Heat Exchanger Methanol Reformer for a HTPEM Fuel Cell Stack

    E-Print Network [OSTI]

    Berning, Torsten

    ) Included in this reaction is the decomposition of methanol, which produces CO: CH3OH CO + 2H2 (90.5 kJ mol a picture of the methanol reformer which has been designed to produce hydrogen for a 1 kWe HTPEM fuel cellExperimental Evaluation of a Pt-based Heat Exchanger Methanol Reformer for a HTPEM Fuel Cell Stack

  10. In situ heat exchanger tube fouling thickness measurements using ultrasonics. Final report on a laboratory feasibility study

    SciTech Connect (OSTI)

    Hirshman, J; Munier, R S.C.

    1980-09-01T23:59:59.000Z

    The growth of fouling layers on heat exchanger surfaces and the corrosion of heat exchanger materials exposed to seawater have been recognized since the beginning of OTEC research as basic problems which could render the concept uneconomical. Consequently, a significant effort has been directed toward predicting, measuring, identifying, explaining and solving potential biofouling and corrosion phenomena. To address this problem, the feasibility of establishing a practical microacoustic technique to measure fouling film thickness in situ on typical OTEC heat exchanger tasks was studied. Seven techniques were studied for this application, including velocity measurements, acoustic diffraction, acoustic interferometer, Doppler flow velocity, pulse echo, critical angle, and surface (shear) wave effects. Of these, the latter five were laboratory tested using conventional microacoustic system components in various configuratons. Only the pulse echo technique yielded promising results. On fouled aluminum plates, thin film layers of 40 ..mu..m and greater were measured using a focused 30 MHz ceramic transducer operated at 25 MHz; this represents a resolution of about 2/3 wavelength. Measurements made on the inside of fouled 1'' aluminum pipes yielded film thicknesses of 75 to 125 ..mu..m. The thinnest layer resolved was approximately 1-1/4 wavelength. The resolution of slime layer thicknesses in the magnitudes of OTEC interest (5 to 30 ..mu..m) using pulse echo microacoustics will require transducer development. In particular, a higher operating frequency (150 to 200 MHz) and advanced material construction is recommended for further research.

  11. The (safety-related) heat exchangers aging management guideline for commercial nuclear power plants, and developments since 1994

    SciTech Connect (OSTI)

    Clauss, J.M.

    1998-08-01T23:59:59.000Z

    The US Department of Energy (DOE), in cooperation with the Electric Power Research Institute (EPRI) and US nuclear power plant utilities, is preparing a series of aging management guidelines (AMGs) for commodity types of components (e.g., heat exchangers, electrical cable and terminations, pumps). Commodities are included in this series based on their importance to continued nuclear plant operation and license renewal. The AMGs contain a detailed summary of operating history, stressors, aging mechanisms, and various types of maintenance and surveillance practices that can be combined to create an effective aging management program. Each AMG is intended for use by the systems engineers and plant maintenance staff (i.e., an AMG is intended to be a hands-on technical document rather than a licensing document). The heat exchangers AMG, published in June 1994, includes the following information of interest to nondestructive examination (NDE) personnel: aging mechanisms determined to be non-significant for all applications; aging mechanisms determined to be significant for some applications; effective conventional programs for managing aging; and effective unconventional programs for managing aging. Since the AMG on heat exchangers was published four years ago, a brief review has been conducted to identify emerging regulatory issues, if any. The results of this review and lessons learned from the collective set of AMGs are presented.

  12. Optimum Design of Micro Bare-Tube Heat Exchanger Tomohisa OKU, Nobuhide KASAGI and Yuji SUZUKI

    E-Print Network [OSTI]

    Tokyo, University of

    for automobiles, electronic equipement cooling system, and recuperator for micro gas turbine. Key words : Heat

  13. EulerianEulerian two-phase numerical simulation of nanofluid laminar forced convection in a microchannel

    E-Print Network [OSTI]

    Harting, Jens

    by a cooling system to guarantee their appropriate performance. One possible way to cool these devises canEulerian­Eulerian two-phase numerical simulation of nanofluid laminar forced convection August 2010 Accepted 5 August 2010 Keywords: Nanofluid Microchannel Two-phase Laminar Heat transfer a b

  14. OSCILLATORY FLOW FORCED CONVECTION IN MICRO HEAT SPREADERS

    E-Print Network [OSTI]

    Beskok, Ali

    transfer devices, micro heat pipes, based on capillary pumping of a multiphase uid in microchannels, have-phase forced convection heat transfer and ow characteristics of water in microchannels, both in the laminar) concept for ef cient transport of large, concentrated heat loads is introduced. The MHS is a single

  15. Dual source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX); Pietsch, Joseph A. (Dallas, TX)

    1982-01-01T23:59:59.000Z

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  16. High-Flux Microchannel Solar Receiver

    Broader source: Energy.gov [DOE]

    This fact sheet describes a high-flux, microchannel solar receiver project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by Oregon State University, is working to demonstrate a microchannel-based solar receiver capable of absorbing high solar flux, while using a variety of liquid and gaseous working fluids. High-flux microchannel receivers have the potential to dramatically reduce the size and cost of a solar receiver by minimizing re-radiation and convective losses.

  17. Multiple pollutant removal using the condensing heat exchanger: Phase 1 final report, November 1995--June 1997. Addendum 2: Task 3 topical report -- Long term wear test

    SciTech Connect (OSTI)

    Kudlac, G.A.

    1998-06-01T23:59:59.000Z

    Long-term operation of a condensing heat exchanger under typical coal-fired flue gas conditions was investigated in Phase 1, Task 3 of the Multiple Pollutant Removal Using the Condensing Heat Exchanger test program. The specific goal of this task was to determine the amount of wear, if any, on the Teflon{reg_sign}-covered heat transfer tubes in a condensing heat exchanger. A pilot-scale single-stage condensing heat exchanger (CHX{reg_sign}) was operated under typical coal-fired flue gas conditions on a continuous basis for a period of approximately 10 months. Operating conditions and particulate loadings for the test unit were monitored, Teflon{reg_sign} film thickness measurements were conducted, and surface replications (which duplicate the surface finish at the microscopic level) were taken at various times during the test. Data from the test indicate that virtually no decrease in Teflon{reg_sign} thickness was observed for the coating on the first two rows of heat exchanger tubes, even at high inlet particulate loadings (400 mg/dscm [0.35 lb/10{sup 6} Btu]). Evidence of wear was present only at the microscopic level, and even then was very minor in severity. Operation at high inlet particulate loadings resulted in accumulated ash deposits within the heat exchanger. Installation of a modified (higher flow rate) wash nozzle manifold substantially reduced subsequent deposit formation.

  18. Development of a Microchannel In Situ Propellant Production System

    SciTech Connect (OSTI)

    Brooks, Kriston P.; Rassat, Scot D.; TeGrotenhuis, Ward E.

    2005-09-01T23:59:59.000Z

    An in situ propellant production (ISPP) plant on future Mars robotic missions can produce oxygen (O2) and methane (CH4) that can be used for propellant for the return voyage. By producing propellants from Mars atmospheric carbon dioxide (CO2) and hydrogen (H2) brought from Earth, the initial mass launched in low Earth orbit can be reduced by 20% to 45%, as compared to carrying all of the propellant for a round-trip mission to the Mars surface from Earth. Pacific Northwest National Laboratory used microchannel architecture to develop a Mars-based In Situ Propellant Production (ISPP) system. This three year research and development effort focused on process intensification and system miniaturization of three primary subsystems: a thermochemical compressor, catalytic reactors, and components for separating gas phases from liquid phases. These systems were designed based on a robotic direct return mission scenario, but can be scaled up to human flight missions by simply numbering up the microchannel devices. The thermochemical compression was developed both using absorption and adsorption. A multichannel adsorption system was designed to meet the full-scale CO2 collection requirements using temperature swing adsorption. Each stage is designed to achieve a 10x compression of CO2. A compression ratio to collect Martian atmospheric CO2 at ~0.8 kPa and compress it to at least 100 kPa can be achieved with two adsorption stages in series. A compressor stage incorporates eight thermally coupled adsorption cells at various stages in the adsorption/desorption cycle to maximize the recuperation of thermal energy and provide a nearly continuous flow of CO2 to the downstream reactors. The thermochemically compressed CO2 is then mixed with hydrogen gas and fed to two reactors: a Sabatier Reaction unit and a Reverse Water/Gas Shift unit. The microchannel architecture allows better heat control than is possible in an adiabatic system, resulting in significantly higher conversion. The reactors can also have reduced mass over conventional hardware. Over 60% conversion was achieved using a two stage RWGS reactor in which water was removed between stages. Sabatier conversions of greater than 85% were achieved in a single stage system. Since the RWGS is endothermic and the Sabatier is exothermic, by combining the two reactions, heat generated from the Sabatier can be used to fuel the RWGS reaction. A combined Sabatier/RWGS reactor was successfully tested. Both the Sabatier and RWGS reactions generate water. The water will be collected and electrolyzed to produce oxygen and recycle the hydrogen. A microchannel phase separator is also under development to separate liquid water from vapor and other gases in these product streams. This phase separator relies on surface forces, not gravitational effects, to separate the water and is therefore suited to space applications. The specific energy of this device reached values of 1200 to 8000 W/K for water mole fractions of 20 to 70%. The phase separator technology was scaled up in a system to removed water from a cathode effluent of a 5 kW PEM fuel cell. In this case a three channel device can remove 43 mL/min of water in 95 SCFM of air. This exceeded the design requirements of the device. A system model of the microchannel ISPP plant was generated to predict the size, weight and performance for the individual components and use it to optimize the overall system. The microchannel technologies developed for CO2 collection, reaction, and phase separation can be used not only for an ISPP system, but also life support, EVA, and lunar applications. The use of microchannel technologies reduces both mass and volume of the system as well as improving the system efficiency.

  19. Design study of a coal-fired thermionic (THX) topped power plant. Volume IV. Thermionic heat exchanger design and costing

    SciTech Connect (OSTI)

    Dick, R.S.; Britt, E.J.

    1980-10-15T23:59:59.000Z

    This volume deals with the details of how thermionic conversion works, and how it is used in a coal-fired furnace to achieve power plant efficiencies of 45%, and overall costs of 36.3 mills/kWh. A review of the fundamental technical aspects of thermionic conversion is given. The overall Thermionic Heat Exchanger (THX) design, the heat pipe design, and the interaction of the heat pipes with the furnace are presented. Also, the operational characteristics of thermionic converters are described. Details on the computer program used to perform the parametric study are given. The overall program flow is reviewed along with the specifics of how the THX subroutine designed the converter to match the conditions imposed. Also, input costs and variables effecting the THX's performance are detailed. The efficiencies of the various power plants studied are given as a function of the air preheat temperature, size of the power plant, and thermionic level of performance.

  20. Field and Laboratory Study of a Ground-Coupled Water Source Heat Pump with an Integral Enthalpy Exchange System for Classrooms

    E-Print Network [OSTI]

    Domitrovic, R.; Hayzen, G. J.; Johnson, W. S.; Chen, F. C.

    2002-01-01T23:59:59.000Z

    technologies is needed to increase the dehumidification abilities of equipment without compromising energy efficiency or the need for fresh ventilation air. To study the effectiveness of integrated heat pump and enthalpy exchange equipment, a nominal 4-ton...

  1. Hybrid slab-microchannel gel electrophoresis system

    DOE Patents [OSTI]

    Balch, J.W.; Carrano, A.V.; Davidson, J.C.; Koo, J.C.

    1998-05-05T23:59:59.000Z

    A hybrid slab-microchannel gel electrophoresis system is described. The hybrid system permits the fabrication of isolated microchannels for biomolecule separations without imposing the constraint of a totally sealed system. The hybrid system is reusable and ultimately much simpler and less costly to manufacture than a closed channel plate system. The hybrid system incorporates a microslab portion of the separation medium above the microchannels, thus at least substantially reducing the possibility of non-uniform field distribution and breakdown due to uncontrollable leakage. A microslab of the sieving matrix is built into the system by using plastic spacer materials and is used to uniformly couple the top plate with the bottom microchannel plate. 4 figs.

  2. Thermal hydraulic performance testing of printed circuit heat exchangers in a high-temperature helium test facility

    SciTech Connect (OSTI)

    Sai K. Mylavarapu; Xiaodong Sun; Richard E. Glosup; Richard N. Christensen; Michael W. Patterson

    2014-04-01T23:59:59.000Z

    In high-temperature gas-cooled reactors, such as a very high temperature reactor (VHTR), an intermediate heat exchanger (IHX) is required to efficiently transfer the core thermal output to a secondary fluid for electricity generation with an indirect power cycle and/or process heat applications. Currently, there is no proven high-temperature (750800 C or higher) compact heat exchanger technology for high-temperature reactor design concepts. In this study, printed circuit heat exchanger (PCHE), a potential IHX concept for high-temperature applications, has been investigated for their heat transfer and pressure drop characteristics under high operating temperatures and pressures. Two PCHEs, each having 10 hot and 10 cold plates with 12 channels (semicircular cross-section) in each plate are fabricated using Alloy 617 plates and tested for their performance in a high-temperature helium test facility (HTHF). The PCHE inlet temperature and pressure were varied from 85 to 390 C/1.02.7 MPa for the cold side and 208790 C/1.02.7 MPa for the hot side, respectively, while the mass flow rate of helium was varied from 15 to 49 kg/h. This range of mass flow rates corresponds to PCHE channel Reynolds numbers of 950 to 4100 for the cold side and 900 to 3900 for the hot side (corresponding to the laminar and laminar-to-turbulent transition flow regimes). The obtained experimental data have been analyzed for the pressure drop and heat transfer characteristics of the heat transfer surface of the PCHEs and compared with the available models and correlations in the literature. In addition, a numerical treatment of hydrodynamically developing and hydrodynamically fully-developed laminar flow through a semicircular duct is presented. Relations developed for determining the hydrodynamic entrance length in a semicircular duct and the friction factor (or pressure drop) in the hydrodynamic entry length region for laminar flow through a semicircular duct are given. Various hydrodynamic entrance region parameters, such as incremental pressure drop number, apparent Fanning friction factor, and hydrodynamic entrance length in a semicircular duct have been numerically estimated.

  3. Micro and nanostructured surfaces for enhanced phase change heat transfer

    E-Print Network [OSTI]

    Chu, Kuang-Han, Ph. D. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Two-phase microchannel heat sinks are of significant interest for thermal management applications, where the latent heat of vaporization offers an efficient method to dissipate large heat fluxes in a compact device. However, ...

  4. Fluidized bed steam reactor including two horizontal cyclone separators and an integral recycle heat exchanger

    SciTech Connect (OSTI)

    Gorzegno, W.P.

    1993-06-15T23:59:59.000Z

    A reactor is described comprising: a vessel; a first furnace section disposed in said vessel; a second furnace section disposed in said vessel; means in each of said furnace sections for receiving a combustible fuel for generating heat and combustion gases; a first heat recovery area located adjacent said furnace sections; a second heat recovery area located adjacent said furnace sections; means for passing said combustion gases from said first furnace section to said first heat recovery area; and means for passing said combustion gases from said second furnace section to said second heat recovery area.

  5. E-Print Network 3.0 - advanced heat exchangers Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and integration Molecular-scale design Advanced materials Digital control technology Hydrogen may be leading... and mechanically integrate the reformer to maximize heat recovery,...

  6. Assessment of strength limiting flaws in ceramic heat exchanger components: Phase 1, Final report, September 28, 1984-June 30, 1986

    SciTech Connect (OSTI)

    Powers, T.; Snyder, J.

    1986-10-01T23:59:59.000Z

    Assurance of energy efficient design lifetimes of high temperature structural ceramics requires the ability to specify acceptance criteria and to test to those criteria. These criteria will be established through nondestructive testing, to determine which defects are detectable, together with fracture mechanics, to calculate effects of indetectable flaws. The first phase of this program is to examine heat exchanger material with four test methods which have shown promise for use in ceramics; ultrasonic scanning, microfocus x-ray, Scanning Laser Acoustic Microscope, and Acoustic Holography. The capabilities, limits, and potential for improvement of these are presented in this report. Destructive testing, material sectioning, and fractography are included. 24 refs., 68 figs., 6 tabs.

  7. Cross-Roll Flow Forming of ODS Alloy Heat Exchanger Tubes for Hoop Creep Enhancement

    SciTech Connect (OSTI)

    Bimal K. Kad

    2006-04-10T23:59:59.000Z

    Mechanically alloyed oxide dispersion strengthened (ODS) Fe-Cr-Al alloy thin walled tubes and sheets, produced via powder processing and consolidation methodologies, are promising materials for eventual use at temperatures up to 1200 C in the power generation industry, far above the temperature capabilities of conventional alloys. Target end-uses range from gas turbine combustor liners to high aspect ratio (L/D) heat exchanger tubes. Grain boundary creep processes at service temperatures, particularly those acting in the hoop direction, are the dominant failure mechanisms for such components. The processed microstructure of ODS alloys consists of high aspect ratio grains aligned parallel to the tube axis, a result of dominant axial metal flow which aligns the dispersoid particles and other impurities in the longitudinal direction. The dispersion distribution is unaltered on a micro scale by recrystallization thermal treatments, but the high aspect ratio grain shape typically obtained limits transverse grain spacing and consequently the hoop creep response. Improving hoop creep in ODS-alloy components will require understanding and manipulating the factors that control the recrystallization behavior, and represents a critical materials design and development challenge that must be overcome in order to fully exploit the potential of ODS alloys. The objectives of this program are to (1) increase creep-strength at temperature in ODS-alloy tube and liner components by 100% via, (2) preferential cross-roll flow forming and grain/particle fibering in the critical hoop direction. The research program outlined here is iterative in nature and is intended to systematically (1) examine and identify post-extrusion forming methodologies to create hoop strengthened tubes, which will be (2) evaluated at ''in-service'' loads at service temperatures and environments. This research program is being conducted in collaboration with the DOE's Oak Ridge National Laboratory and the vested industrial partner Special Metals Corporation. In this ninth quarter of performance, program activities are continued for Tasks 2, 3 and 4 and are reported herein. Two sets of MA956 tube material samples rotary crossrolled at rolling angles of {beta} = 2{sup o} and 8{sup o} are processed in Task 3 and available for mechanical property testing in the remainder of this project. These samples are at various stages of creep testing and evaluation in Task 4. The creep rigs are being upgraded to handle long term testing at 1000 C and above. Reduced test times at accelerated temperatures will allow for additional testes to be conducted resulting in overall robust creep data statistics. The creep performance enhancement in cross-rolled MA956 material samples versus the base creep property is elucidated. Additional creep enhancements are derived when flow formed tubes are flattened at 900 C and recrystallized. The Larsen-Miller parameter for the improvised thermo-mechanical processing now approaches 52. At least 2-3 orders of magnitude of improvement in creep rates/day are demonstrated for the cross-rolled samples versus the base reference tests.

  8. Multiple source heat pump

    DOE Patents [OSTI]

    Ecker, Amir L. (Duncanville, TX)

    1983-01-01T23:59:59.000Z

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  9. A Semi-Empirical Model for Porous Media Heat Exchanger Design Richard A. Wirtz1

    E-Print Network [OSTI]

    Wirtz, Richard A.

    and the effectiveness of the porous wall are always maximum when it is operated with the number of transfer units of the porous matrix greater than two (ntu 2). Furthermore, if the porous matrix is composed of a packed bed matrix is minimum when ntu 2. This suggest that for many design requirements, the porous media exchanger

  10. Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003

    SciTech Connect (OSTI)

    Gary E. Rochau and Thurlow W.H. Caffey, Sandia National Laboratories, Albuquerque, NM 87185-0740; Bahram Nassersharif and Gabe V. Garcia, Department of Mechanical Engineering, New Mexico State University, Las Cruces, NM 88003-8001; Russell P. Jedlicka, Klipsch School of Electrical and Computer Engineering, New Mexico State University, Las Cruces, NM 88003-8001

    2003-05-01T23:59:59.000Z

    OAK B204 Continuous-Wave Radar to Detect Defects Within Heat Exchangers and Steam Generator Tubes ; Revised September 3, 2003. A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The technique is 100% volumetric, and may find smaller defects, more rapidly, and less expensively than present methods. The project described in this report was a joint development effort between Sandia National Laboratories (SNL) and New Mexico State University (NMSU) funded by the US Department of Energy. The goal of the project was to research, design, and develop a new concept utilizing a continuous wave radar to detect defects inside metallic tubes and in particular nuclear plant steam generator tubing. The project was divided into four parallel tracks: computational modeling, experimental prototyping, thermo-mechanical design, and signal detection and analysis.

  11. Microchannel cooling of face down bonded chips

    DOE Patents [OSTI]

    Bernhardt, Anthony F. (Berkeley, CA)

    1993-01-01T23:59:59.000Z

    Microchannel cooling is applied to flip-chip bonded integrated circuits, in a manner which maintains the advantages of flip-chip bonds, while overcoming the difficulties encountered in cooling the chips. The technique is suited to either multichip integrated circuit boards in a plane, or to stacks of circuit boards in a three dimensional interconnect structure. Integrated circuit chips are mounted on a circuit board using flip-chip or control collapse bonds. A microchannel structure is essentially permanently coupled with the back of the chip. A coolant delivery manifold delivers coolant to the microchannel structure, and a seal consisting of a compressible elastomer is provided between the coolant delivery manifold and the microchannel structure. The integrated circuit chip and microchannel structure are connected together to form a replaceable integrated circuit module which can be easily decoupled from the coolant delivery manifold and the circuit board. The coolant supply manifolds may be disposed between the circuit boards in a stack and coupled to supplies of coolant through a side of the stack.

  12. Microchannel cooling of face down bonded chips

    DOE Patents [OSTI]

    Bernhardt, A.F.

    1993-06-08T23:59:59.000Z

    Microchannel cooling is applied to flip-chip bonded integrated circuits, in a manner which maintains the advantages of flip-chip bonds, while overcoming the difficulties encountered in cooling the chips. The technique is suited to either multi chip integrated circuit boards in a plane, or to stacks of circuit boards in a three dimensional interconnect structure. Integrated circuit chips are mounted on a circuit board using flip-chip or control collapse bonds. A microchannel structure is essentially permanently coupled with the back of the chip. A coolant delivery manifold delivers coolant to the microchannel structure, and a seal consisting of a compressible elastomer is provided between the coolant delivery manifold and the microchannel structure. The integrated circuit chip and microchannel structure are connected together to form a replaceable integrated circuit module which can be easily decoupled from the coolant delivery manifold and the circuit board. The coolant supply manifolds may be disposed between the circuit boards in a stack and coupled to supplies of coolant through a side of the stack.

  13. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)

    1982-01-01T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  14. Integrated three-dimensional module heat exchanger for power electronics cooling

    DOE Patents [OSTI]

    Bennion, Kevin; Lustbader, Jason

    2013-09-24T23:59:59.000Z

    Embodiments discussed herein are directed to a power semiconductor packaging that removes heat from a semiconductor package through one or more cooling zones that are located in a laterally oriented position with respect to the semiconductor package. Additional embodiments are directed to circuit elements that are constructed from one or more modular power semiconductor packages.

  15. System and method for optically locating microchannel positions

    DOE Patents [OSTI]

    Brewer, Laurence R. (Oakland, CA); Kimbrough, Joseph (Pleasanton, CA); Balch, Joseph (Livermore, CA); Davidson, J. Courtney (Livermore, CA)

    2001-01-01T23:59:59.000Z

    A system and method is disclosed for optically locating a microchannel position. A laser source generates a primary laser beam which is directed at a microchannel plate. The microchannel plates include microchannels at various locations. A back-reflectance beam detector receives a back-reflected beam from the plate. The back-reflected beam is generated when the primary beam reflects off of the plate. A photodiode circuit generates a trigger signal when the back-reflected beam exceeds a predetermined threshold, indicating a presence of the microchannel. The method of the present invention includes the steps of generating a primary beam, directing the primary beam to a plate containing a microchannel, receiving from the plate a back-reflected beam generated in response to the primary beam, and generating a trigger signal when the back-reflected beam exceeds a predetermined threshold which corresponds to a presence of the microchannel.

  16. High power density fuel cell comprising an array of microchannels

    DOE Patents [OSTI]

    Sopchak, David A; Morse, Jeffrey D; Upadhye, Ravindra S; Kotovsky, Jack; Graff, Robert T

    2014-05-06T23:59:59.000Z

    A phosphoric acid fuel cell according to one embodiment includes an array of microchannels defined by a porous electrolyte support structure extending between bottom and upper support layers, the microchannels including fuel and oxidant microchannels; fuel electrodes formed along some of the microchannels; and air electrodes formed along other of the microchannels. A method of making a phosphoric acid fuel cell according to one embodiment includes etching an array of microchannels in a substrate, thereby forming walls between the microchannels; processing the walls to make the walls porous, thereby forming a porous electrolyte support structure; forming anode electrodes along some of the walls; forming cathode electrodes along other of the walls; and filling the porous electrolyte support structure with a phosphoric acid electrolyte. Additional embodiments are also disclosed.

  17. Parametric performance studies on fluidized-bed heat exchangers. Task I. Fouling characteristics. Yearly technical progress report, 28 July 1981-31 July 1982

    SciTech Connect (OSTI)

    None

    1982-09-01T23:59:59.000Z

    Analyses and experiments are being performed in this program to investigate the heat transfer performance of single and multi-stage shallow fluidized beds for application to the recovery of heat from sources such as waste heat, and coal combustion or coal gasification. The work, which is an extension of that done previously under contracts EC-77-C-03-1433 and DE-AC03-79-ET11348, consists of three tasks. In Task 1, tests have been conducted to investigate the effects of liquid condensate fouling on fluidized bed heat exchanger performance. Liquid condensates used in these tests were water and glycerol (which is more viscous than water). The tests showed that fluidized bed heat exchanger performance is degraded by condensation within the bed and the degradation is caused by bed particles adhering to the heat exchanger surface, not by particle agglomeration. Liquid condensate did not continuously build up within the bed. After a period of dry-out, heat transfer equal to that obtained prior to condensation was again obtained. 8 figures, 1 table.

  18. LOx breathing system with gas permeable-liquid impermeable heat exchange and delivery hose

    DOE Patents [OSTI]

    Hall, M.N.

    1996-04-30T23:59:59.000Z

    Life support apparatus is composed of: a garment for completely enclosing a wearer and constructed for preventing passage of gas from the environment surrounding the garment; a portable receptacle holding a quantity of an oxygen-containing fluid in liquid state, the fluid being in a breathable gaseous state when at standard temperature and pressure; a fluid flow member secured within the garment and coupled to the receptacle for conducting the fluid in liquid state from the receptacle to the interior of the garment; and a fluid flow control device connected for causing fluid to flow from the receptacle to the fluid flow member at a rate determined by the breathable air requirement of the wearer, wherein fluid in liquid state is conducted into the interior of the garment at a rate to be vaporized and heated to a breathable temperature by body heat produced by the wearer. 6 figs.

  19. Lox breathing system with gas permeable-liquid impermeable heat exchange and delivery hose

    DOE Patents [OSTI]

    Hall, Mark N. (Richland, WA)

    1996-01-01T23:59:59.000Z

    Life support apparatus composed of: a garment (2): for completely enclosing a wearer and constructed for preventing passage of gas from the environment surrounding the garment (2); a portable receptacle (6) holding a quantity of an oxygen-containing fluid in liquid state, the fluid being in a breathable gaseous; state when at standard temperature and pressure; a fluid flow member (16) secured within the garment (2) and coupled to the receptacle (6) for conducting the fluid in liquid state from the receptacle (6) to the interior of the garment (2); and a fluid flow control device (14) connected for causing fluid to flow from the receptacle (6) to the fluid flow member (16) at a rate determined by the breathable air requirement of the wearer, wherein fluid in liquid state is conducted into the interior of the garment (2) at a rate to be vaporized and heated to a breathable temperature by body heat produced by the wearer.

  20. Numerical Investigation of Thermal Hydraulic Behavior of Supercritical Carbon Dioxide in Compact Heat Exchangers

    E-Print Network [OSTI]

    Fatima, Roma

    2012-02-14T23:59:59.000Z

    desirable. Henceforth, various turbulence models were used to study their impact on the heat transfer solution for these problems. The present numerical work focuses on improving the CFD model and methodologies in order to capture... NOMENCLATURE Sc Supercritical Tcr Critical temperature Vcr Critical volume Tpc Pseudo-critical temperature Ppc Pseudo-critical pressure Pcr Critical pressure Pop Operating pressure Tw Wall temperature Tb Bulk temperature Tin Inlet...

  1. Electrokinetic transport in microchannels with random roughness

    SciTech Connect (OSTI)

    Wang, Moran [Los Alamos National Laboratory; Kang, Qinjun [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We present a numerical framework to model the electrokinetic transport in microchannels with random roughness. The three-dimensional microstructure of the rough channel is generated by a random generation-growth method with three statistical parameters to control the number density, the total volume fraction, and the anisotropy characteristics of roughness elements. The governing equations for the electrokinetic transport are solved by a high-efficiency lattice Poisson?Boltzmann method in complex geometries. The effects from the geometric characteristics of roughness on the electrokinetic transport in microchannels are therefore modeled and analyzed. For a given total roughness volume fraction, a higher number density leads to a lower fluctuation because of the random factors. The electroosmotic flow rate increases with the roughness number density nearly logarithmically for a given volume fraction of roughness but decreases with the volume fraction for a given roughness number density. When both the volume fraction and the number density of roughness are given, the electroosmotic flow rate is enhanced by the increase of the characteristic length along the external electric field direction but is reduced by that in the direction across the channel. For a given microstructure of the rough microchannel, the electroosmotic flow rate decreases with the Debye length. It is found that the shape resistance of roughness is responsible for the flow rate reduction in the rough channel compared to the smooth channel even for very thin double layers, and hence plays an important role in microchannel electroosmotic flows.

  2. Rheology and Convective Heat Transfer of Colloidal Gas Aphrons in Horizontal Minichannels

    E-Print Network [OSTI]

    Tseng, H.; Pilon, L.; Warrier, G.

    2006-01-01T23:59:59.000Z

    Single-phase convective heat transfer in microchannels: aand Newell, M. E. , 1967. Heat transfer in fully developed3 /s at 130 W. Water CGA Heat Transfer Coefficient, h (W/m 2

  3. The TFTR E Parallel B Spectrometer for Mass and Energy Resolved Multi-Ion Charge Exchange Diagnostics

    SciTech Connect (OSTI)

    A.L. Roquemore; S.S. Medley

    1998-01-01T23:59:59.000Z

    The Charge Exchange Neutral Analyzer diagnostic for the Tokamak Fusion Test Reactor was designed to measure the energy distributions of both the thermal ions and the supra thermal populations arising from neutral-beam injection and ion cyclotron radio-frequency heating. These measurements yield the plasma ion temperature, as well as several other plasma parameters necessary to provide an understanding of the plasma condition and the performance of the auxiliary heating methods. For this application, a novel charge-exchange spectrometer using a dee-shaped region of parallel electric and magnetic fields was developed at the Princeton Plasma Physics Laboratory. The design and performance of this spectrometer is described in detail, including the effects of exposure of the microchannel plate detector to magnetic fields, neutrons, and tritium.

  4. Evaluation Metrics for Intermediate Heat Exchangers for Next Generation Nuclear Reactors

    SciTech Connect (OSTI)

    Piyush Sabharwall; Eung Soo Kim; Nolan Anderson

    2011-06-01T23:59:59.000Z

    The Department of Energy (DOE) is working with industry to develop a next generation, high-temperature gas-cooled reactor (HTGR) as a part of the effort to supply the United States with abundant, clean, and secure energy as initiated by the Energy Policy Act of 2005 (EPAct; Public Law 109-58,2005). The NGNP Project, led by the Idaho National Laboratory (INL), will demonstrate the ability of the HTGR to generate hydrogen, electricity, and/or high-quality process heat for a wide range of industrial applications.

  5. Technology development for corrosion-resistant condensing heat exchangers. Final report, September 1984-October 1985

    SciTech Connect (OSTI)

    Stickford, G.H.; Hindin, B.; Talbert, S.G.; Agrawal, A.K.; Murphy, M.J.

    1985-10-01T23:59:59.000Z

    The report presents the results of a study to develop technology to support gas-appliance manufacturers in the selection of corrosion-resistant materials for high-efficiency, gas-fired residential space-heating equipment. Condensate sampling during the 1984-85 heating season has indicated that condensate chloride levels from indoor-air combustion normally vary by 200 or 300% from week-to-week due to normal homeowner activities. Several homes, however, had chloride levels greater than the benchmark level (26 ppm) nearly every week. These results support the hypothesis that high indoor chloride levels are more likely caused by on-going homeowner activities than by a rare chloride-producing event. The mean chloride level found in outdoor-air condensate samples was five to eight times lower than the mean of the indoor data. The chloride level corresponding to the 99.5 percentile for the outdoor samples could not be estimated because of the limited amount of outdoor data.

  6. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers, Volumes 1, 2.

    SciTech Connect (OSTI)

    Upadhyaya, Belle R.; Hines, J. Wesley; Lu, Baofu; Huang, Xuedong; Penha, Rosani, L.; Perillo, Sergio, R.; Zhao, Ke

    2005-06-03T23:59:59.000Z

    The overall purpose of this Nuclear Engineering Education Research (NEER) project was to integrate new, innovative, and existing technologies to develop a fault diagnostics and characterization system for nuclear plant steam generators (SG) and heat exchangers (HX). Issues related to system level degradation of SG and HX tubing, including tube fouling, performance under reduced heat transfer area, and the damage caused by stress corrosion cracking, are the important factors that influence overall plant operation, maintenance, and economic viability of nuclear power systems. The research at The University of Tennessee focused on the development of techniques for monitoring process and structural integrity of steam generators and heat exchangers. The objectives of the project were accomplished by the completion of the following tasks. All the objectives were accomplished during the project period. This report summarizes the research and development activities, results, and accomplishments during June 2001 ???????????????????????????????? September 2004. ???????????????????????????????· Development and testing of a high-fidelity nodal model of a U-tube steam generator (UTSG) to simulate the effects of fouling and to generate a database representing normal and degraded process conditions. Application of the group method of data handling (GMDH) method for process variable prediction. ???????????????????????????????· Development of a laboratory test module to simulate particulate fouling of HX tubes and its effect on overall thermal resistance. Application of the GMDH technique to predict HX fluid temperatures, and to compare with the calculated thermal resistance. ???????????????????????????????· Development of a hybrid modeling technique for process diagnosis and its evaluation using laboratory heat exchanger test data. ???????????????????????????????· Development and testing of a sensor suite using piezo-electric devices for monitoring structural integrity of both flat plates (beams) and tubing. Experiments were performed in air, and in water with and without bubbly flow. ???????????????????????????????· Development of advanced signal processing methods using wavelet transforms and image processing techniques for isolating flaw types. ???????????????????????????????· Development and implementation of a new nonlinear and non-stationary signal processing method, called the Hilbert-Huang transform (HHT), for flaw detection and location. This is a more robust and adaptive approach compared to the wavelet transform

  7. On-Line Monitoring and Diagnostics of the Integrity of Nuclear Plant Steam Generators and Heat Exchangers.

    SciTech Connect (OSTI)

    Belle R. Upadhyaya; J. Wesley Hines

    2004-09-27T23:59:59.000Z

    The overall purpose of this Nuclear Engineering Education Research (NEER) project was to integrate new, innovative, and existing technologies to develop a fault diagnostics and characterization system for nuclear plant steam generators (SG) and heat exchangers (HX). Issues related to system level degradation of SG and HX tubing, including tube fouling, performance under reduced heat transfer area, and the damage caused by stress corrosion cracking, are the important factors that influence overall plant operation, maintenance, and economic viability of nuclear power systems. The research at The University of Tennessee focused on the development of techniques for monitoring process and structural integrity of steam generators and heat exchangers. The objectives of the project were accomplished by the completion of the following tasks. All the objectives were accomplished during the project period. This report summarizes the research and development activities, results, and accomplishments during June 2001-September 2004. (1) Development and testing of a high-fidelity nodal model of a U-tube steam generator (UTSG) to simulate the effects of fouling and to generate a database representing normal and degraded process conditions. Application of the group method of data handling (GMDH) method for process variable prediction. (2) Development of a laboratory test module to simulate particulate fouling of HX tubes and its effect on overall thermal resistance. Application of the GMDH technique to predict HX fluid temperatures, and to compare with the calculated thermal resistance. (3) Development of a hybrid modeling technique for process diagnosis and its evaluation using laboratory heat exchanger test data. (4) Development and testing of a sensor suite using piezo-electric devices for monitoring structural integrity of both flat plates (beams) and tubing. Experiments were performed in air, and in water with and without bubbly flow. (5) Development of advanced signal processing methods using wavelet transforms and image processing techniques for isolating flaw types. (6) Development and implementation of a new nonlinear and non-stationary signal processing method, called the Hilbert-Huang transform (HHT), for flaw detection and location. This is a more robust and adaptive approach compared to the wavelet transform. (7) Implementation of a moving-window technique in the time domain for detecting and quantifying flaw types in tubular structures. A window zooming technique was also developed for flaw location in tubes. (8) Theoretical study of elastic wave propagation (longitudinal and shear waves) in metallic flat plates and tubing with and without flaws. (9) Simulation of the Lamb wave propagation using the finite-element code ABAQUS. This enabled the verification of the experimental results. The research tasks included both analytical research and experimental studies. The experimental results helped to enhance the robustness of fault monitoring methods and to provide a systematic verification of the analytical results. The results of this research were disseminated in scientific meetings. A journal manuscript was submitted for publication. The new findings of this research have potential applications in aerospace and civil structures. The report contains a complete bibliography that was developed during the course of the project.

  8. Fluid Mechanics -1 An oil is used in a heat exchanger. The internal geometry consists of many small diameter tubes of fixed length

    E-Print Network [OSTI]

    Virginia Tech

    Fluid Mechanics - 1 An oil is used in a heat exchanger. The internal geometry consists of many small diameter tubes of fixed length (mounted in a bundle as indicated in the sketch). The oil is pumped). Assume the steady flow of the oil through each small tube is in the laminar regime. It is proposed

  9. Study on Micro-scale Ceramic Catalytic Combustor with Embedded Heat Exchange Channels Takashi OKAMASA, Gwang-Goo LEE, Yuji SUZUKI, and Nobuhide KASAGI

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    Study on Micro-scale Ceramic Catalytic Combustor with Embedded Heat Exchange Channels Takashi combustion of butane is investigated. A cost-effective and robust ceramic combustor is developed using high anodic oxidation of aluminum layer. In order to increase the thermal efficiency, a combustor

  10. Combined refrigeration system with a liquid pre-cooling heat exchanger

    DOE Patents [OSTI]

    Gaul, Christopher J.

    2003-07-01T23:59:59.000Z

    A compressor-pump unit for use in a vapor-compression refrigeration system is provided. The compressor-pump unit comprises a driving device including a rotatable shaft. A compressor is coupled with a first portion of the shaft for compressing gaseous refrigerant within the vapor-compression refrigeration system. A liquid pump is coupled with a second portion of the shaft for receiving liquid refrigerant having a first pressure and for discharging the received liquid refrigerant at a second pressure with the second pressure being higher than the first pressure by a predetermined amount such that the discharged liquid refrigerant is subcooled. A pre-cooling circuit is connected to the liquid pump with the pre-cooling circuit being exposed to the gaseous refrigerant whereby the gaseous refrigerant absorbs heat from the liquid refrigerant, prior to the liquid refrigerant entering the liquid pump.

  11. Comparison of binary mixture heat and mass transfer analysis with single-component heat and mass transfer analysis in the design of GAX absorber/desorber[Generator-Absorber heat eXchange

    SciTech Connect (OSTI)

    Cao, J.; Christensen, R.N.

    2000-07-01T23:59:59.000Z

    The GAX cycle is an elegant way of achieving higher effect performance with single-stage configuration. One of the key components of the GAX cycle is the absorber/desorber heat exchanger, which carries out internal heat recovery. This paper investigated two different models for the design of an absorber/desorber in the GAX system. In model A, single-component forced convective boiling with the physical properties of the mixture was assumed for the cocurrent desorption process, which is basically an approximation technique adopted widely so far. In model B, the multi-component effect of the binary mixture on the forced convective boiling transfer was considered. Significant degradation of heat and mass transfer was observed under binary mixture boiling condition as opposed to the single-component boiling. The results show that about 57% of extra heat transfer area would be needed under the case being investigated if the fluid is considered as a binary mixture rather than a single-component fluid. This paper provides a basic guideline for designing a properly sized GAX absorber-desorber.

  12. Industrial Waste Heat Recovery Using Heat Pipes

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01T23:59:59.000Z

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  13. Process for separating nitrogen from methane using microchannel process technology

    DOE Patents [OSTI]

    Tonkovich, Anna Lee (Marysville, OH); Qiu, Dongming (Dublin, OH); Dritz, Terence Andrew (Worthington, OH); Neagle, Paul (Westerville, OH); Litt, Robert Dwayne (Westerville, OH); Arora, Ravi (Dublin, OH); Lamont, Michael Jay (Hilliard, OH); Pagnotto, Kristina M. (Cincinnati, OH)

    2007-07-31T23:59:59.000Z

    The disclosed invention relates to a process for separating methane or nitrogen from a fluid mixture comprising methane and nitrogen, the process comprising: (A) flowing the fluid mixture into a microchannel separator, the microchannel separator comprising a plurality of process microchannels containing a sorption medium, the fluid mixture being maintained in the microchannel separator until at least part of the methane or nitrogen is sorbed by the sorption medium, and removing non-sorbed parts of the fluid mixture from the microchannel separator; and (B) desorbing the methane or nitrogen from the sorption medium and removing the desorbed methane or nitrogen from the microchannel separator. The process is suitable for upgrading methane from coal mines, landfills, and other sub-quality sources.

  14. Evaporative CO2 cooling using microchannels etched in silicon for the future LHCb vertex detector

    E-Print Network [OSTI]

    A. Nomerotski; J. Buytart; P. Collins; R. Dumps; E. Greening; M. John; A. Mapelli; A. Leflat; Y. Li; G. Romagnoli; B. Verlaat

    2013-02-16T23:59:59.000Z

    The extreme radiation dose received by vertex detectors at the Large Hadron Collider dictates stringent requirements on their cooling systems. To be robust against radiation damage, sensors should be maintained below -20 degree C and at the same time, the considerable heat load generated in the readout chips and the sensors must be removed. Evaporative CO2 cooling using microchannels etched in a silicon plane in thermal contact with the readout chips is an attractive option. In this paper, we present the first results of microchannel prototypes with circulating, two-phase CO2 and compare them to simulations. We also discuss a practical design of upgraded VELO detector for the LHCb experiment employing this approach.

  15. Development of a coal-fueled Internal Manifold Heat Exchanger (IMHEX reg sign ) molten carbonate fuel cell

    SciTech Connect (OSTI)

    Not Available

    1991-09-01T23:59:59.000Z

    The design of a CGMCFC electric generation plant that will provide a cost of eletricity (COE) which is lower than that of current electric generation technologies and which is competitive with other long-range electric generating systems is presented. This effort is based upon the Internal Manifold Heat Exchanger (IMHEX) technology as developed by the Institute of Gas Technology (IGT). The project was executed by selecting economic and performance objectives for alternative plant arrangements while considering process constraints identified during IMHEX fuel cell development activities at ICT. The four major subsystems of a coal-based MCFC power plant are coal gasification, gas purification, fuel cell power generation and the bottoming cycle. The design and method of operation of each subsystem can be varied, and, depending upon design choices, can have major impact on both the design of other subsystems and the resulting cost of electricity. The challenge of this project was to select, from a range of design parameters, those operating conditions that result in a preferred plant design. Computer modelling was thus used to perform sensitivity analyses of as many system variables as program resources and schedules would permit. In any systems analysis, it is imperative that the evaluation methodology be verifiable and comparable. The TAG Class I develops comparable (if imprecise) data on performance and costs for the alternative cases being studied. It identifies, from a range of options, those which merit more exacting scrutiny to be undertaken at the second level, TAG class II analysis.

  16. Single Channel Testing for Characterization of the Direct Gas Cooled Reactor and the SAFE-100 Heat Exchanger

    SciTech Connect (OSTI)

    Bragg-Sitton, S.M. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Propulsion Research Center, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Kapernick, R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Godfroy, T.J. [Propulsion Research Center, NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)

    2004-02-04T23:59:59.000Z

    Experiments have been designed to characterize the coolant gas flow in two space reactor concepts that are currently under investigation by NASA Marshall Space Flight Center and Los Alamos National Laboratory: the direct-drive gas-cooled reactor (DDG) and the SAFE-100 heatpipe-cooled reactor (HPR). For the DDG concept, initial tests have been completed to measure pressure drop versus flow rate for a prototypic core flow channel, with gas exiting to atmospheric pressure conditions. The experimental results of the completed DDG tests presented in this paper validate the predicted results to within a reasonable margin of error. These tests have resulted in a re-design of the flow annulus to reduce the pressure drop. Subsequent tests will be conducted with the re-designed flow channel and with the outlet pressure held at 150 psi (1 MPa). Design of a similar test for a nominal flow channel in the HPR heat exchanger (HPR-HX) has been completed and hardware is currently being assembled for testing this channel at 150 psi. When completed, these test programs will provide the data necessary to validate calculated flow performance for these reactor concepts (pressure drop and film temperature rise)

  17. Preliminary studies on the heat exchanger option for S-CO{sub 2} power conversion cycle coupled to water cooled SMR

    SciTech Connect (OSTI)

    Ahn, Y.; Lee, J. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Inst. of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Lee, J. I. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Inst. of Science and Technology, 373-1 Guseong-dong Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Dept. of Nuclear Engineering, Khalifa Univ. of Science, Technology and Research (KUSTAR), P.O.Box 127788, Abu Dhabi (United Arab Emirates)

    2012-07-01T23:59:59.000Z

    For more than a half century, the steam Rankine cycle had been the major power conversion cycle for a nuclear power plant. However, as the interest on the next generation reactors grows, a variety of alternative power conversion systems have been studied. Among them, the S-CO{sub 2} cycle (Supercritical carbon dioxide Brayton cycle) is considered as a promising candidate due to several benefits such as 1) Relatively high thermal efficiency at relatively low turbine inlet temperature, 2) High efficiency with simple lay-out 3) Compactness of turbo-machineries. 4) Compactness of total cycle combined with PCHE (Printed Circuit Heat Exchanger). According to the conventional classification of heat exchangers (HE), there are three kind of HE, 1) Tubular HEs, 2) Plate-type HEs, 3) Extended surface HEs. So far, the researcher has mostly assumed PCHE type HE for the S-CO{sub 2} cycle due to its compactness with reasonably low pressure drop. However, PCHE is currently one of the most expensive components in the cycle, which can have a negative effect on the economics of the cycle. Therefore, an alternative for the HE should be seriously investigated. By comparing the operating condition (pressure and temperature) there are three kind of HE in the S-CO{sub 2} cycle, 1) IHX (Intermediate Heat exchanger) 2) Recuperator and 3) Pre-cooler. In each heat exchanger, hot side and cold side coolants are different, i.e. reactor coolant to S-CO{sub 2} (IHX), S-CO{sub 2} to S-CO{sub 2}(Recuperator), S-CO{sub 2} to water (Pre-cooler). By considering all the attributes mentioned above, all existing types of heat exchangers are compared to find a possible alternative to PCHE. The comparing factors are 1) Size(volume), 2) Cost. Plate fin type HEs are considered to be the most competitive heat exchanger regarding the size and the cost after some improvements on the design limit are made. (authors)

  18. Determining the quality and quantity of heat produced by proton exchange membrane fuel cells with application to air-cooled stacks for combined heat and power

    E-Print Network [OSTI]

    Victoria, University of

    with application to air-cooled stacks for combined heat and power by Thomas Schmeister B.Sc., University to air-cooled stacks for combined heat and power by Thomas Schmeister B.Sc., University of Colorado, 1991 cells as a heat and electrical power source for residential combined heat and power (CHP

  19. Heat pump with freeze-up prevention

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1981-01-01T23:59:59.000Z

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

  20. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, G.

    1982-06-16T23:59:59.000Z

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  1. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN)

    1984-01-01T23:59:59.000Z

    The efficiency of an absorption heat pump system is improved by conducting liquid from a second stage evaporator thereof to an auxiliary heat exchanger positioned downstream of a primary heat exchanger in the desorber of the system.

  2. MAGNITUDE AND VARIANCE OF ACOUSTIC ENERGY DENSITY IN MICROCHANNEL ACOUSTOPHORESIS

    E-Print Network [OSTI]

    and Martin Wiklund1 1 Dept. of Applied Physics, Royal Institute of Technology (KTH), Stockholm, SWEDEN 2 Dept modulation, Acoustic energy density, Microchannel INTRODUCTION Microchannel acoustophoresis is a powerful) causing a half-wave resonance across the channel width or height. However, a generic problem with SF

  3. Optimal artificial neural network architecture selection for performance prediction of compact heat exchanger with the EBaLM-OTR technique

    SciTech Connect (OSTI)

    Dumidu Wijayasekara; Milos Manic; Piyush Sabharwall; Vivek Utgikar

    2011-07-01T23:59:59.000Z

    Artificial Neural Networks (ANN) have been used in the past to predict the performance of printed circuit heat exchangers (PCHE) with satisfactory accuracy. Typically published literature has focused on optimizing ANN using a training dataset to train the network and a testing dataset to evaluate it. Although this may produce outputs that agree with experimental results, there is a risk of over-training or overlearning the network rather than generalizing it, which should be the ultimate goal. An over-trained network is able to produce good results with the training dataset but fails when new datasets with subtle changes are introduced. In this paper we present EBaLM-OTR (error back propagation and Levenberg-Marquardt algorithms for over training resilience) technique, which is based on a previously discussed method of selecting neural network architecture that uses a separate validation set to evaluate different network architectures based on mean square error (MSE), and standard deviation of MSE. The method uses k-fold cross validation. Therefore in order to select the optimal architecture for the problem, the dataset is divided into three parts which are used to train, validate and test each network architecture. Then each architecture is evaluated according to their generalization capability and capability to conform to original data. The method proved to be a comprehensive tool in identifying the weaknesses and advantages of different network architectures. The method also highlighted the fact that the architecture with the lowest training error is not always the most generalized and therefore not the optimal. Using the method the testing error achieved was in the order of magnitude of within 10{sup -5} - 10{sup -3}. It was also show that the absolute error achieved by EBaLM-OTR was an order of magnitude better than the lowest error achieved by EBaLM-THP.

  4. Design Method for the Heating/Cooling Coil in the AHU Based on Fuzzy Logic - Part Two: Design of the Minimum Heat-Exchanging Unit

    E-Print Network [OSTI]

    Zhang, J.; Chen, Y.; Liang, Z.

    2006-01-01T23:59:59.000Z

    Zhang Yongpan Chen Zhen Liang Ph.D. Professor Doctoral Candidate Instructor School of Municipal & Environmental Eng, Harbin Institute of Technology Harbin P. R. China, 150090 zhangjili@hit.edu.cn Abstract: Considering a heating/cooling coil... heat indoor, as is given by Equation (5) (noted in difference scheme), where Qr denotes sensible heat amount indoor (KW); ? denotes time variable (s); ? r denotes air density indoor (Kg/m3); CP denotes air specific heat at constant pressure (KJ...

  5. A change in the temperature or a transformation of the phase of a material requires an exchange of heat with the surroundings. This exchange of heat can be used to store thermal

    E-Print Network [OSTI]

    Braun, Paul

    . Transformations of singlecomponent material typically occur at constant temperature. For example, ice transforms to water at a constant temperature of 0 °C. The heat required to produce the transformation is called are heated separately; the heating power applied to the sample and the reference is controlled to produce

  6. Microchannel Reactor System for Catalytic Hydrogenation

    SciTech Connect (OSTI)

    Adeniyi Lawal; Woo Lee; Ron Besser; Donald Kientzler; Luke Achenie

    2010-12-22T23:59:59.000Z

    We successfully demonstrated a novel process intensification concept enabled by the development of microchannel reactors, for energy efficient catalytic hydrogenation reactions at moderate temperature, and pressure, and low solvent levels. We designed, fabricated, evaluated, and optimized a laboratory-scale microchannel reactor system for hydrogenation of onitroanisole and a proprietary BMS molecule. In the second phase of the program, as a prelude to full-scale commercialization, we designed and developed a fully-automated skid-mounted multichannel microreactor pilot plant system for multiphase reactions. The system is capable of processing 1 10 kg/h of liquid substrate, and an industrially relevant immiscible liquid-liquid was successfully demonstrated on the system. Our microreactor-based pilot plant is one-of-akind. We anticipate that this process intensification concept, if successfully demonstrated, will provide a paradigm-changing basis for replacing existing energy inefficient, cost ineffective, environmentally detrimental slurry semi-batch reactor-based manufacturing practiced in the pharmaceutical and fine chemicals industries.

  7. Methods for applying microchannels to separate methane using liquid absorbents, especially ionic liquid absorbents from a mixture comprising methane and nitrogen

    DOE Patents [OSTI]

    Tonkovich, Anna Lee Y. (Dublin, OH); Litt, Robert D. (Westerville, OH); Dongming, Qiu (Dublin, OH); Silva, Laura J. (Plain City, OH); Lamont, Micheal Jay (Plain City, OH); Fanelli, Maddalena (Plain City, OH); Simmons, Wayne W. (Plain city, OH); Perry, Steven (Galloway, OH)

    2011-10-04T23:59:59.000Z

    Methods of using microchannel separation systems including absorbents to improve thermal efficiency and reduce parasitic power loss. Energy is typically added to desorb methane and then energy or heat is removed to absorb methane using a working solution. The working solution or absorbent may comprise an ionic liquid, or other fluids that demonstrate a difference in affinity between methane and nitrogen in a solution.

  8. The Economic and Environmental Aspects of Heat Exchanger Cleaning -- How FP&L Has Used the Newly Patented MCC Process to Clean Turbine Lube Oil Coolers to Maximize Efficiency and Minimize Waste

    E-Print Network [OSTI]

    Wood, H. A. T.

    of efficient and timely cleaning of heat exchangers. There are great differences in the cleaning processes that are used to clean exchanger bundles in industry today. The cleaning of turbine lube oil coolers is a specialized case in point. A newly patented...

  9. Contraction/expansion flow of dilute elastic solutions in microchannels

    E-Print Network [OSTI]

    Scott, Timothy Peter, 1980-

    2004-01-01T23:59:59.000Z

    An experimental study is conducted on the nature of extensional flows of mobile dilute polymer solutions in microchannel. By observing such fluids on the microscale it is possible to generate large strain rates ([approximately] ...

  10. Laminated microchannel devices, mixing units and method of making same

    DOE Patents [OSTI]

    Bennett, Wendy D [Kennewick, WA; Hammerstrom, Donald J [West Richland, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA

    2002-10-17T23:59:59.000Z

    A laminated microchannel device is described in which there is a unit operation process layer that has longitudinal channel. The longitudinal channel is cut completely through the layer in which the unit process operation resides. Both the device structure and method of making the device provide significant advantages in terms of simplicity and efficiency. A static mixing unit that can be incorporated in the laminated microchannel device is also described.

  11. Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

    DOE Patents [OSTI]

    Lewis, Arthur E. (Los Altos, CA); Braun, Robert L. (Livermore, CA); Mallon, Richard G. (Livermore, CA); Walton, Otis R. (Livermore, CA)

    1986-01-01T23:59:59.000Z

    A cascading bed retorting process and apparatus in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

  12. Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange

    DOE Patents [OSTI]

    Lewis, A.E.; Braun, R.L.; Mallon, R.G.; Walton, O.R.

    1983-09-21T23:59:59.000Z

    A cascading bed retorting process and apparatus are disclosed in which cold raw crushed shale enters at the middle of a retort column into a mixer stage where it is rapidly mixed with hot recycled shale and thereby heated to pyrolysis temperature. The heated mixture then passes through a pyrolyzer stage where it resides for a sufficient time for complete pyrolysis to occur. The spent shale from the pyrolyzer is recirculated through a burner stage where the residual char is burned to heat the shale which then enters the mixer stage.

  13. Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

    SciTech Connect (OSTI)

    Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.; Cauchy, Charles J.

    2010-09-01T23:59:59.000Z

    The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique power panel approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designing a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin power panels consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 C and cold-side temperatures = 40 C. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.

  14. A novel approach to heat transfer enhancement using trapezoid shaped spiral strips to promote tumble and swirl in a slot shaped channel used in heat exchangers

    E-Print Network [OSTI]

    Segura, D.; Acharya, S.

    2012-01-01T23:59:59.000Z

    Heat transfer results for a given slot shaped channel with a 3:1 aspect ratio are presented using various configurations of a trapezoid shaped spiral wound strips to enhance swirl and tumble motion in the channel. The Reynolds numbers investigated...

  15. Proceedings of NHTC'00: 34 th National Heat Transfer Conference

    E-Print Network [OSTI]

    Kandlikar, Satish

    Proceedings of NHTC'00: 34 th National Heat Transfer Conference Pittsburgh, Pennsylvania, August 20 ON SINGLE- AND TWO-PHASE HEAT TRANSFER CHARACTERISTICS IN A MICROCHANNEL Michael S June Graduate Student study investigates the heat transfer characteristics of single and two-phase flows in a 200 m wide

  16. Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector

    E-Print Network [OSTI]

    Fajans, Joel

    Antiproton, positron, and electron imaging with a microchannel plate/phosphor detector ALPHA; accepted 2 November 2009; published online 1 December 2009 A microchannel plate MCP /phosphor screen Microchannel plate MCP /phosphor screen based diag- nostics have proved invaluable in studying the evolution

  17. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11T23:59:59.000Z

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  18. Mass and Heat Recovery

    E-Print Network [OSTI]

    Hindawai, S. M.

    2010-01-01T23:59:59.000Z

    In the last few years heat recovery was under spot and in air conditioning fields usually we use heat recovery by different types of heat exchangers. The heat exchanging between the exhaust air from the building with the fresh air to the building...

  19. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01T23:59:59.000Z

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  20. Heat pump having improved defrost system

    DOE Patents [OSTI]

    Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN); Murphy, Richard W. (Knoxville, TN)

    1998-01-01T23:59:59.000Z

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger.

  1. Heat pump having improved defrost system

    DOE Patents [OSTI]

    Chen, F.C.; Mei, V.C.; Murphy, R.W.

    1998-12-08T23:59:59.000Z

    A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

  2. Experimental development of the predictive relations for the eddy exchange coefficients for momentum and heat in the atmospheric boundary layer

    E-Print Network [OSTI]

    Jensen, Paul Alfred

    2012-06-07T23:59:59.000Z

    , increase in w by removing the dummy -1 bases was 4. 2 cm/sec , and u for these runs was 330 cm/sec -I ?? Using sin [w/u] as a measure of the tilt of the wind field gave an inclination of . 72', in fair agreement with KAIMAL's relation. Therefore.... '?'illlam H. Clayton Direct measurements of the eddy fluxes of mo. . . entum and heat were. made in the atmospheric boundary layer simultaneously with measurements of the profiles of average wind velocity and tempera- ture to evaluate the capability...

  3. Heating system

    SciTech Connect (OSTI)

    Nishman, P.J.

    1983-03-08T23:59:59.000Z

    A heating system utilizing solar panels and buried ground conduits to collect and store heat which is delivered to a heatpump heat exchanger. A heat-distribution fluid continuously circulates through a ground circuit to transfer heat from the ground to the heat exchanger. The ground circuit includes a length of buried ground conduit, a pump, a check valve and the heat exchanger. A solar circuit, including a solar panel and a second pump, is connected in parallel with the check valve so that the distribution fluid transfers solar heat to the heat exchanger for utilization and to the ground conduit for storage when the second pump is energized. A thermostatically instrumented control system energizes the second pump only when the temperature differential between the solar panel inlet and outlet temperatures exceeds a predetermined value and the ground temperature is less than a predetermined value. Consequently, the distribution fluid flows through the solar panel only when the panel is capable of supplying significant heat to the remainder of the system without causing excessive drying of the ground.

  4. Modeling gas flow through microchannels and nanopores Subrata Roya)

    E-Print Network [OSTI]

    Roy, Subrata

    Plasma Dynamics Laboratory, Department of Mechanical Engineering Kettering University, Flint, Michigan microchannels and nanopores. Presented two-dimensional numerical results for Poiseuille flow of a simple fluid extensively used in our everyday life. Some MEMS devices have also been designed in the field of fluid applica

  5. RESEARCH PAPER Fouling and its mitigation in silicon microchannels used

    E-Print Network [OSTI]

    Kandlikar, Satish

    RESEARCH PAPER Fouling and its mitigation in silicon microchannels used for IC chip cooling Jeffrey@rit.edu 123 Microfluid Nanofluid (2008) 5:357­371 DOI 10.1007/s10404-007-0254-4 #12;lE electrophoretic and micro- electronics. In recent years, the proliferation of Micro Electro Mechanical Systems (MEMS) has

  6. Low-Cost Manufacturable Microchannel Systems for Passive

    E-Print Network [OSTI]

    for use in fuel cell systems need development in order to achieve cost targets. Low-cost, highLow-Cost Manufacturable Microchannel Systems for Passive PEM Water Management IIPS Number 16910 LowLow--CostCost;2 Project objective: Create a low cost and passive PEM water management system Project objective

  7. Research on thermophoretic and inertial aspects of the ash particle deposition on heat exchanger surfaces in coal-fired equipment

    SciTech Connect (OSTI)

    Rosner, D.E.

    1986-12-01T23:59:59.000Z

    In support of the above mentioned objectives, we have initiated theoretical studies in the following three interrelated areas : (a) Interaction of inertial- and thermophoretic effects in well-defined laminar dusty-gas'' flows. (b) Self-regulated sticking and deposit erosion in the simultaneous presence of vapor or submicron glue'' (c) Use of packed bed and tube-bank heat transfer and friction correlations to provide the basis for future tube-bank fouling predictions.During the first three months of Grant DE-FG22-86 PC 90756, we have: (1) Designed and initiated construction of the microcombustor particle-laden jet facility described in Section 3.1. (2) Initiated theoretical studies of the interaction of inertial and thermophoretic effects, the role of simultaneous vapor arrival in determining particle sticking and erosion probabilities, and mass transport phenomena in deep tube banks.

  8. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01T23:59:59.000Z

    low volumetric heat capacity (relative to liquid-cooledvolumetric heat capacity relative to the liquid salt. Thisvolumetric heat capacity (?*c p ) of the liquid salt permits

  9. Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment

    SciTech Connect (OSTI)

    Rosner, D.E.

    1987-03-01T23:59:59.000Z

    In support of the above mentioned objectives, we are carrying out theoretical studies in the following three interrelated areas: (a) Interaction of inertial- and thermophoretic effects in well-defined laminar dusty-gas'' flows; (b) Self-regulated sticking and deposit erosion in the simultaneous presence of vapor or submicron glue''; (c) Use of packed bed and tube-bank heat transfer and friction correlations to provide the basis for future tube-bank fouling predictions. During this second quarter of Grant DE-FG22-86 PC 90756. we have: (1) done preliminary gas velocity and temperature calibrations of the micro-combustor exit gas flow jet and initiated the development of both a monodispersed droplet feed system and powder feed system to provide monodispersed particle laden jets covering a broad spectrum of particle sizes (ca. 0.5--50 m diameter); and, (2) demonstrated the ability of impacting supermicron particles to remove predeposited submicron particles on a platinum target, using real-time optical reflectivity methods. These preliminary experiments will be extended and discussed in our next Quarterly Technical Report.

  10. Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment

    SciTech Connect (OSTI)

    Rosner, D.E.

    1989-03-01T23:59:59.000Z

    Little is yet known (theoretically or experimentally) about the simultaneous effects of particle inertia, particle thermophoresis and high mass loading on the important engineering problem of predicting deposition rates from flowing dusty'' gases. For this reason, we investigate the motion of particles present at nonnegligible mass loading in a flowing nonisothermal gaseous medium and their deposition on strongly cooled or heated solid objects by examining the instructive case of steady axisymmetric dusty gas'' flow between two infinite disks: an inlet (porous) disk and the impermeable target'' disk -- a flow not unlike that encountered in recent seeded-flame experiments. Since this stagnation flow/geometry admits interesting self-similar solutions at all Reynolds numbers, we are able to predict laminar flow mass-, momentum- and energy-transfer rate coefficients over a wide range of particle mass loadings, dimensionless particle relaxation times (Stokes numbers), dimensionless thermophoretic diffusivities, and gas Reynolds numbers. As a by-product, we illustrate the accuracy and possible improvement of our previous diffusion model'' for tightly coupled dusty gas systems. Moreover, we report new results illustrating the dependence of the important critical'' Stokes number (for incipient particle impaction) on particle mass loading and wall/gas temperature ratio for dust-laden gas motion towards overheated'' solid surfaces. The present formulation and insulating transport coefficients should not only be useful in explaining/predicting recent deposition rate trends in seeded'' flame experiments, but also highly mass-loaded systems of technological interest.

  11. Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment

    SciTech Connect (OSTI)

    Rosner, D.E.

    1988-03-01T23:59:59.000Z

    During the present reporting period, we have initiated work on (a) the interpretation of our recent data (see QTR5) on deposition rates under the simultaneous influence of inertia and thermophoresis, (b) the possible rate of particle photophoresis in environments characterized by high radiative heat loads. and (c) the influence of particle size distributions on total mass deposition rates. The fruits of these initiatives will be reported in subsequent quarterly technical reports. Here, we focus on our recent theoretical results in the important but previously uncharted area of the relations between particulate deposition mechanisms, deposit microstructure and deposit properties. Experimental verification of some of the most interesting predictions will be the subject of future HTCRE-Lab studies. Recent discussions with fouling engineers have convinced us that despite recent advances in our ability to predict particle deposition rates in convective-diffusion environments, the important connection between resulting deposit properties (effective thermal conductivity permeability, [hor ellipsis]) and deposition mechanism remain poorly understood and only scarcely studied. Accordingly, as part of this DOE-PETC program we have developed a discrete stochastic model to simulate particulate deposition processes resulting from a combination of deposition mechanisms.

  12. Development of a coal-fueled Internal Manifold Heat Exchanger (IMHEX{reg_sign}) molten carbonate fuel cell. Volumes 1--6, Final report

    SciTech Connect (OSTI)

    Not Available

    1991-09-01T23:59:59.000Z

    The design of a CGMCFC electric generation plant that will provide a cost of eletricity (COE) which is lower than that of current electric generation technologies and which is competitive with other long-range electric generating systems is presented. This effort is based upon the Internal Manifold Heat Exchanger (IMHEX) technology as developed by the Institute of Gas Technology (IGT). The project was executed by selecting economic and performance objectives for alternative plant arrangements while considering process constraints identified during IMHEX fuel cell development activities at ICT. The four major subsystems of a coal-based MCFC power plant are coal gasification, gas purification, fuel cell power generation and the bottoming cycle. The design and method of operation of each subsystem can be varied, and, depending upon design choices, can have major impact on both the design of other subsystems and the resulting cost of electricity. The challenge of this project was to select, from a range of design parameters, those operating conditions that result in a preferred plant design. Computer modelling was thus used to perform sensitivity analyses of as many system variables as program resources and schedules would permit. In any systems analysis, it is imperative that the evaluation methodology be verifiable and comparable. The TAG Class I develops comparable (if imprecise) data on performance and costs for the alternative cases being studied. It identifies, from a range of options, those which merit more exacting scrutiny to be undertaken at the second level, TAG class II analysis.

  13. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

    1983-01-01T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  14. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F.; Moore, Paul B.

    1983-06-21T23:59:59.000Z

    An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

  15. Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,

    E-Print Network [OSTI]

    Kandlikar, Satish

    Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

  16. Determination of the Number of Tube Rows to Obtain Closure for Volume Averaging Theory Based Model of Fin-and-Tube Heat Exchangers

    E-Print Network [OSTI]

    Zhou, Feng; Hansen, Nicholas E; Geb, David J; Catton, Ivan

    2011-01-01T23:59:59.000Z

    Fig. 3 Journal of Heat Transfer Grid system for 2-row caseDomain and Grid System. Since the fin-and- tube heat

  17. Direct contact heat exchanger performance

    SciTech Connect (OSTI)

    Wahl, E. F.

    1981-03-12T23:59:59.000Z

    Although the final performance result of a DCHE is the cost of the net electricity produced, the best performance cannot be achieved without optimizing the components of the system as well as the whole system. Thus collection and analysis of data on the internal performance of the column assists in optimizing the operation of the particular column as well as in suggesting ways for improving the operation and design of future columns.

  18. Shell and Tube Heat Exchangers

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector GeneralDepartment of Energyof the Americas |DOE Former Worker/EnergyFracture

  19. High pressure ceramic heat exchanger

    DOE Patents [OSTI]

    Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

    1999-01-01T23:59:59.000Z

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the reinforcing member and having a strengthening member wrapped around the refractory material. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  20. High pressure ceramic heat exchanger

    DOE Patents [OSTI]

    Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

    1998-01-01T23:59:59.000Z

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  1. High pressure ceramic heat exchanger

    DOE Patents [OSTI]

    Harkins, B.D.; Ward, M.E.

    1998-09-22T23:59:59.000Z

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present header assembly when used with recuperators reduces the brittle effect of a portion of the ceramic components. Thus, the present header assembly used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present header assembly is comprised of a first ceramic member, a second ceramic member, a strengthening reinforcing member being in spaced relationship to the first ceramic member and the second ceramic member. The header assembly is further comprised of a refractory material disposed in contacting relationship with the first ceramic member, the second ceramic member and the strengthening reinforcing member. The present header assembly provides a high strength load bearing header assembly having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 5 figs.

  2. Shell and Tube Heat Exchangers

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists' Research |RegulationRenewable Energy (EERE) |SeniorIt seems likeShawn Wang - Director

  3. Microchannel Networks for Nanowire Patterning Benjamin Messer, Jae Hee Song, and Peidong Yang*

    E-Print Network [OSTI]

    Yang, Peidong

    Microchannel Networks for Nanowire Patterning Benjamin Messer, Jae Hee Song, and Peidong Yang - ] nanowires on substrates using microchannel networks.5 This strategy relies on the solvent evaporation induced self-assembly of [Mo3Se3 -] infinite chains within the micro- channels. Aligned [Mo3Se3 - ] wires6

  4. Refrigerant charge management in a heat pump water heater

    DOE Patents [OSTI]

    Chen, Jie; Hampton, Justin W.

    2014-06-24T23:59:59.000Z

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

  5. Process for making unsaturated hydrocarbons using microchannel process technology

    DOE Patents [OSTI]

    Tonkovich, Anna Lee (Dublin, OH); Yuschak, Thomas (Lewis Center, OH); LaPlante, Timothy J. (Columbus, OH); Rankin, Scott (Columbus, OH); Perry, Steven T. (Galloway, OH); Fitzgerald, Sean Patrick (Columbus, OH); Simmons, Wayne W. (Dublin, OH); Mazanec, Terry (Solon, OH) Daymo, Eric (Dublin, OH)

    2011-04-12T23:59:59.000Z

    The disclosed invention relates to a process for converting a feed composition comprising one or more hydrocarbons to a product comprising one or more unsaturated hydrocarbons, the process comprising: flowing the feed composition and steam in contact with each other in a microchannel reactor at a temperature in the range from about 200.degree. C. to about 1200.degree. C. to convert the feed composition to the product, the process being characterized by the absence of catalyst for converting the one or more hydrocarbons to one or more unsaturated hydrocarbons. Hydrogen and/or oxygen may be combined with the feed composition and steam.

  6. Heat rejection system

    DOE Patents [OSTI]

    Smith, Gregory C. (Richland, WA); Tokarz, Richard D. (Richland, WA); Parry, Jr., Harvey L. (Richland, WA); Braun, Daniel J. (Richland, WA)

    1980-01-01T23:59:59.000Z

    A cooling system for rejecting waste heat consists of a cooling tower incorporating a plurality of coolant tubes provided with cooling fins and each having a plurality of cooling channels therein, means for directing a heat exchange fluid from the power plant through less than the total number of cooling channels to cool the heat exchange fluid under normal ambient temperature conditions, means for directing water through the remaining cooling channels whenever the ambient temperature rises above the temperature at which dry cooling of the heat exchange fluid is sufficient and means for cooling the water.

  7. anisothermal heat treatment: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of outdoor heat exchanger hydrophobic treatment on the performance of an air source heat pump Texas A&M University - TxSpace Summary: The effects of outdoor heat exchanger...

  8. Thulium-170 heat source

    DOE Patents [OSTI]

    Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

    1992-01-01T23:59:59.000Z

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  9. Heat pump employing optimal refrigerant compressor for low pressure ratio applications

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1982-01-01T23:59:59.000Z

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerant heat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

  10. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    DOE Patents [OSTI]

    Jacobson, Stephen C. (Knoxville, TN); Ramsey, J. Michael (Knoxville, TN); Culbertson, Christopher T. (Oak Ridge, TN); Whitten, William B. (Lancing, TN); Foote, Robert S. (Oak Ridge, TN)

    2011-03-22T23:59:59.000Z

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  11. Methods for forming small-volume electrical contacts and material manipulations with fluid microchannels

    DOE Patents [OSTI]

    Jacobson, Stephen C. (Knoxville, TN); Ramsey, J. Michael (Knoxville, TN); Culbertson, Christopher T. (Oak Ridge, TN); Whitten, William B. (Lancing, TN); Foote, Robert S. (Oak Ridge, TN)

    2011-12-27T23:59:59.000Z

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  12. Investigating the stability of viscoelastic stagnation flows in T-shaped microchannels

    E-Print Network [OSTI]

    Soulage, Johannes

    We investigate the stability of steady planar stagnation flows of a dilute polyethylene oxide (PEO) solution using T-shaped microchannels. The precise flow rate control and well-defined geometries achievable with microfluidic ...

  13. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    DOE Patents [OSTI]

    Jacobson, Stephen C. (Knoxville, TN); Ramsey, J. Michael (Knoxville, TN)

    2007-11-20T23:59:59.000Z

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microchannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  14. Development of photo-patterned composite structures in microchannels for oil reservoir research

    E-Print Network [OSTI]

    Lee, Hyundo

    2014-01-01T23:59:59.000Z

    Starting from unstructured glass microchannels, we develop a new method of micromodel fabrication. We build composite structures in a bottom-up manner with ultraviolet projection lithography where the composite structures ...

  15. Dehydrogenation of liquid fuel in microchannel catalytic reactor

    DOE Patents [OSTI]

    Toseland, Bernard Allen (Coopersburg, PA); Pez, Guido Peter (Allentown, PA); Puri, Pushpinder Singh (Emmaus, PA)

    2010-08-03T23:59:59.000Z

    The present invention is an improved process for the storage and delivery of hydrogen by the reversible hydrogenation/dehydrogenation of an organic compound wherein the organic compound is initially in its hydrogenated state. The improvement in the route to generating hydrogen is in the dehydrogenation step and recovery of the dehydrogenated organic compound resides in the following steps: introducing a hydrogenated organic compound to a microchannel reactor incorporating a dehydrogenation catalyst; effecting dehydrogenation of said hydrogenated organic compound under conditions whereby said hydrogenated organic compound is present as a liquid phase; generating a reaction product comprised of a liquid phase dehydrogenated organic compound and gaseous hydrogen; separating the liquid phase dehydrogenated organic compound from gaseous hydrogen; and, recovering the hydrogen and liquid phase dehydrogenated organic compound.

  16. Axially Tapered And Bilayer Microchannels For Evaporative Cooling Devices

    DOE Patents [OSTI]

    Nilson, Robert (Cardiff, CA); Griffiths, Stewart (Livermore, CA)

    2005-10-04T23:59:59.000Z

    The invention consists of an evaporative cooling device comprising one or more microchannels whose cross section is axially reduced to control the maximum capillary pressure differential between liquid and vapor phases. In one embodiment, the evaporation channels have a rectangular cross section that is reduced in width along a flow path. In another embodiment, channels of fixed width are patterned with an array of microfabricated post-like features such that the feature size and spacing are gradually reduced along the flow path. Other embodiments incorporate bilayer channels consisting of an upper cover plate having a pattern of slots or holes of axially decreasing size and a lower fluid flow layer having channel widths substantially greater than the characteristic microscale dimensions of the patterned cover plate. The small dimensions of the cover plate holes afford large capillary pressure differentials while the larger dimensions of the lower region reduce viscous flow resistance.

  17. Collimator application for microchannel plate image intensifier resolution improvement

    DOE Patents [OSTI]

    Thomas, Stanley W. (Livermore, CA)

    1996-02-27T23:59:59.000Z

    A collimator is included in a microchannel plate image intensifier (MCPI). Collimators can be useful in improving resolution of MCPIs by eliminating the scattered electron problem and by limiting the transverse energy of electrons reaching the screen. Due to its optical absorption, a collimator will also increase the extinction ratio of an intensifier by approximately an order of magnitude. Additionally, the smooth surface of the collimator will permit a higher focusing field to be employed in the MCP-to-collimator region than is currently permitted in the MCP-to-screen region by the relatively rough and fragile aluminum layer covering the screen. Coating the MCP and collimator surfaces with aluminum oxide appears to permit additional significant increases in the field strength, resulting in better resolution.

  18. Microchannel cross load array with dense parallel input

    DOE Patents [OSTI]

    Swierkowski, Stefan P.

    2004-04-06T23:59:59.000Z

    An architecture or layout for microchannel arrays using T or Cross (+) loading for electrophoresis or other injection and separation chemistry that are performed in microfluidic configurations. This architecture enables a very dense layout of arrays of functionally identical shaped channels and it also solves the problem of simultaneously enabling efficient parallel shapes and biasing of the input wells, waste wells, and bias wells at the input end of the separation columns. One T load architecture uses circular holes with common rows, but not columns, which allows the flow paths for each channel to be identical in shape, using multiple mirror image pieces. Another T load architecture enables the access hole array to be formed on a biaxial, collinear grid suitable for EDM micromachining (square holes), with common rows and columns.

  19. Collimator application for microchannel plate image intensifier resolution improvement

    DOE Patents [OSTI]

    Thomas, S.W.

    1996-02-27T23:59:59.000Z

    A collimator is included in a microchannel plate image intensifier (MCPI). Collimators can be useful in improving resolution of MCPIs by eliminating the scattered electron problem and by limiting the transverse energy of electrons reaching the screen. Due to its optical absorption, a collimator will also increase the extinction ratio of an intensifier by approximately an order of magnitude. Additionally, the smooth surface of the collimator will permit a higher focusing field to be employed in the MCP-to-collimator region than is currently permitted in the MCP-to-screen region by the relatively rough and fragile aluminum layer covering the screen. Coating the MCP and collimator surfaces with aluminum oxide appears to permit additional significant increases in the field strength, resulting in better resolution. 2 figs.

  20. High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array

    DOE Patents [OSTI]

    Freitas, Barry L. (Livermore, CA)

    1998-01-01T23:59:59.000Z

    An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver>4kW/cm2 of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources.

  1. Stirling cycle engine and heat pump

    SciTech Connect (OSTI)

    Mitchell, M.P.

    1986-11-18T23:59:59.000Z

    A method is described of operating a hot gas engine comprising a cylinder having one end thereof connected to the other end thereof through at least two separate closed heat exchanger assemblies. Each comprises heated heat exchanger means and cooled heat exchanger means serially arranged, the hot end of each such closed heat exchanger assembly is attached to the same end of the cylinder. Each closed heat exchanger assembly is equipped with valve means at each end thereof, the cylinder accommodating a double-acting reciprocating piston means. The piston means cyclically displaces and is displaced by a volume of gas for each such closed heat exchanger assembly. The volumes of gas are alternately confined in and released from the closed heat exchanger assemblies by the valves.

  2. Formation of microchannels from low-temperature plasma-deposited silicon oxynitride

    DOE Patents [OSTI]

    Matzke, Carolyn M. (Los Lunas, NM); Ashby, Carol I. H. (Edgewood, NM); Bridges, Monica M. (Albuquerque, NM); Manginell, Ronald P. (Albuquerque, NM)

    2000-01-01T23:59:59.000Z

    A process for forming one or more fluid microchannels on a substrate is disclosed that is compatible with the formation of integrated circuitry on the substrate. The microchannels can be formed below an upper surface of the substrate, above the upper surface, or both. The microchannels are formed by depositing a covering layer of silicon oxynitride over a mold formed of a sacrificial material such as photoresist which can later be removed. The silicon oxynitride is deposited at a low temperature (.ltoreq.100.degree. C.) and preferably near room temperature using a high-density plasma (e.g. an electron-cyclotron resonance plasma or an inductively-coupled plasma). In some embodiments of the present invention, the microchannels can be completely lined with silicon oxynitride to present a uniform material composition to a fluid therein. The present invention has applications for forming microchannels for use in chromatography and electrophoresis. Additionally, the microchannels can be used for electrokinetic pumping, or for localized or global substrate cooling.

  3. RESIDENTIAL EXCHANGE

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    establishes the right of Pacific Northwest electric utilities to participate in the Residential Exchange Program that provides wholesale power cost benefits for residential and...

  4. Heat Pipes: An Industrial Application

    E-Print Network [OSTI]

    Murray, F.

    1984-01-01T23:59:59.000Z

    This paper reviews the basics of heat pipe exchangers. Included are how they are constructed, how they operate, where they have application, and various aspects of evaluating a potential application. After discussing the technical aspects of heat...

  5. Note: Precision viscosity measurement using suspended microchannel resonators

    SciTech Connect (OSTI)

    Lee, I.; Lee, J. [Department of Mechanical Engineering, Sogang University, Seoul 121-742 (Korea, Republic of); Park, K. [Department of Mechanical, Industrial, and Systems Engineering, University of Rhode Island, Kingston, Rhode Island 02881 (United States)

    2012-11-15T23:59:59.000Z

    We report the characterization of a suspended microchannel resonator (SMR) for viscosity measurements in a low viscosity regime (<10 mPa s) using two measurement schemes. First, the quality factor (Q-factor) of the SMR was characterized with glycerol-water mixtures. The measured Q-factor at 20 Degree-Sign C exhibits a bilinear behavior with the sensitivity of 1281 (mPa s){sup -1} for a lower (1-4 mPa s) and 355 (mPa s){sup -1} for a higher viscosity range (4-8 mPa s), respectively. The second scheme is the vibration amplitude monitoring of the SMR running in a closed loop feedback. When compared in terms of the measurement time, the amplitude-based measurement takes only 0.1 {approx} 1 ms while the Q-factor-based measurement takes {approx}30 s. However, the viscosity resolution of the Q-factor-based measurement is at least three times better than the amplitude-based measurement. By comparing the Q-factors of heavy water and 9.65 wt.% glycerol-water mixture that have very similar viscosities but different densities, we confirmed that the SMR can measure the dynamic viscosity without the density correction. The obtained results demonstrate that the SMR can measure the fluid viscosity with high precision and even real-time monitoring of the viscosity change is possible with the amplitude-based measurement scheme.

  6. Active microchannel fluid processing unit and method of making

    DOE Patents [OSTI]

    Bennett, Wendy D [Kennewick, WA; Martin, Peter M [Kennewick, WA; Matson, Dean W [Kennewick, WA; Roberts, Gary L [West Richland, WA; Stewart, Donald C [Richland, WA; Tonkovich, Annalee Y [Pasco, WA; Zilka, Jennifer L [Pasco, WA; Schmitt, Stephen C [Dublin, OH; Werner, Timothy M [Columbus, OH

    2002-12-10T23:59:59.000Z

    The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

  7. Active microchannel fluid processing unit and method of making

    DOE Patents [OSTI]

    Bennett, Wendy D. (Kennewick, WA) [Kennewick, WA; Martin, Peter M. (Kennewick, WA) [Kennewick, WA; Matson, Dean W. (Kennewick, WA) [Kennewick, WA; Roberts, Gary L. (West Richland, WA) [West Richland, WA; Stewart, Donald C. (Richland, WA) [Richland, WA; Tonkovich, Annalee Y. (Pasco, WA) [Pasco, WA; Zilka, Jennifer L. (Pasco, WA) [Pasco, WA; Schmitt, Stephen C. (Dublin, OH) [Dublin, OH; Werner, Timothy M. (Columbus, OH) [Columbus, OH

    2001-01-01T23:59:59.000Z

    The present invention is an active microchannel fluid processing unit and method of making, both relying on having (a) at least one inner thin sheet; (b) at least one outer thin sheet; (c) defining at least one first sub-assembly for performing at least one first unit operation by stacking a first of the at least one inner thin sheet in alternating contact with a first of the at least one outer thin sheet into a first stack and placing an end block on the at least one inner thin sheet, the at least one first sub-assembly having at least a first inlet and a first outlet; and (d) defining at least one second sub-assembly for performing at least one second unit operation either as a second flow path within the first stack or by stacking a second of the at least one inner thin sheet in alternating contact with second of the at least one outer thin sheet as a second stack, the at least one second sub-assembly having at least a second inlet and a second outlet.

  8. Ultrafast gating of proximity-focused microchannel-plate intensifiers

    SciTech Connect (OSTI)

    Lundy, A.S.; Iverson, A.E.

    1982-01-01T23:59:59.000Z

    Proximity-focused, microchannel-plate (MCP) image intensifiers have been used at Los Alamos for many years to allow single frame film and video exposure times in the range of 2.5 to 10 ns. There is now a program to reduce gating times to < 1 ns. This paper reviews previous work and the problems in achieving good resolution with gating times of < 1 ns. The key problems involve applying fast electrical gating signals to the tube elements. We present computer modeling studies of the combined tube, tube connection, and pulser system and show that low photocathode surface resistivity must be obtained to permit fast gating between the photocathode and the MCP input. We discuss ways of making low-resistivity S20 photocathodes, using gallium arsenide photocathodes, and various means of gating the tubes. A variety of pulser designs are being experimentally evaluated including spark gaps, avalanche transistors, Krytron tubes with sharpening gaps, step recovery diodes, and photoconductive elements (PCEs). The results of these studies are presented. Because of the high capacitances involved in most gating schemes, the tube connection geometry must be of low-impedance design, and our solution is presented. Finally, ways of testing these high-speed camera systems are discussed.

  9. Vitrification of ion exchange resins

    DOE Patents [OSTI]

    Cicero-Herman, Connie A. (Aiken, SC); Workman, Rhonda Jackson (North Augusta, SC)

    2001-01-01T23:59:59.000Z

    The present invention relates to vitrification of ion exchange resins that have become loaded with hazardous or radioactive wastes, in a way that produces a homogenous and durable waste form and reduces the disposal volume of the resin. The methods of the present invention involve directly adding borosilicate glass formers and an oxidizer to the ion exchange resin and heating the mixture at sufficient temperature to produce homogeneous glass.

  10. Cavitation in flow through a micro-orifice inside a silicon microchannel Chandan Mishra and Yoav Pelesa)

    E-Print Network [OSTI]

    Peles, Yoav

    Cavitation in flow through a micro-orifice inside a silicon microchannel Chandan Mishra and Yoav) Hydrodynamic cavitation in flows through a micro-orifice entrenched in a microchannel has been detected. The flow of de-ionized water through the micro-orifice reveals the presence of multifarious cavitating flow

  11. MNHMT2009-18491 An Experimental Investigation of Droplet Detachment in High-Speed Microchannel Air Flow

    E-Print Network [OSTI]

    Hidrovo, Carlos H.

    MNHMT2009-18491 An Experimental Investigation of Droplet Detachment in High-Speed Microchannel Air detachment in a confined microchannel under highly inertial air flow. Experimental observations show of magnitude sense. These results show that although shear stress at the droplet-air interface may contribute

  12. Methods for forming small-volume electrical contacts and material manipulations with fluidic microchannels

    DOE Patents [OSTI]

    Jacobson, Stephen C. (Knoxville, TN); Ramsey, J. Michael (Knoxville, TN); Culbertson, Christopher T. (Oak Ridge, TN); Whitten, William B. (Lancing, TN); Foote, Robert S. (Oak Ridge, TN)

    2011-04-26T23:59:59.000Z

    A microfabricated device employing a bridging membrane and methods for electrokinetic transport of a liquid phase biological or chemical material using the same are described. The bridging membrane is deployed in or adjacent to a microchannel and permits either ionic current flow or the transport of gas species, while inhibiting the bulk flow of material. The use of bridging membranes in accordance with this invention is applicable to a variety of processes, including electrokinetically induced pressure flow in a region of a microehannel that is not influenced by an electric field, sample concentration enhancement and injection, as well as improving the analysis of materials where it is desired to eliminate electrophoretic bias. Other applications of the bridging membranes according to this invention include the separation of species from a sample material, valving of fluids in a microchannel network, mixing of different materials in a microchannel, and the pumping of fluids.

  13. Neuronal micro-culture engineering by microchannel devices of cellular scale dimensions

    E-Print Network [OSTI]

    Goyal, Gaurav

    2015-01-01T23:59:59.000Z

    Purpose: The purpose of the current study was to investigate the effect of microchannel geometry on neuronal cultures and to maintain these cultures for long period of time (over several weeks) inside the closed microchannels of cellular scale dimensions. Methods: The primary hippocampal neurons from E-18 rat were cultured inside the closed polydimethylsiloxane (PDMS) microchannels of varying sizes. The effect of the channel geometry on the spatial and the temporal variations in the neural microenvironment was investigated by studying neural maturation and variation in the media osmolality respectively. The cultures were maintained for longer time spans by PDMS device pretreatment, control on media evaporation (by using hydrophobic ethylene propylene membrane) and an effective culture maintenance protocol. Further, the devices were integrated with the planar microelectrode arrays (MEA) to record spontaneous electrical activity. Results: A direct influence of channel geometry on neuron maturation was observed ...

  14. Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment. Quarterly techical report, December 1, 1986--February 28, 1987

    SciTech Connect (OSTI)

    Rosner, D.E.

    1987-03-01T23:59:59.000Z

    In support of the above mentioned objectives, we are carrying out theoretical studies in the following three interrelated areas: (a) Interaction of inertial- and thermophoretic effects in well-defined laminar ``dusty-gas`` flows; (b) Self-regulated sticking and deposit erosion in the simultaneous presence of vapor or submicron ``glue``; (c) Use of packed bed and tube-bank heat transfer and friction correlations to provide the basis for future tube-bank fouling predictions. During this second quarter of Grant DE-FG22-86 PC 90756. we have: (1) done preliminary gas velocity and temperature calibrations of the micro-combustor exit gas flow jet and initiated the development of both a monodispersed droplet feed system and powder feed system to provide monodispersed particle laden jets covering a broad spectrum of particle sizes (ca. 0.5--50 m diameter); and, (2) demonstrated the ability of impacting supermicron particles to remove predeposited submicron particles on a platinum target, using real-time optical reflectivity methods. These preliminary experiments will be extended and discussed in our next Quarterly Technical Report.

  15. Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect

    E-Print Network [OSTI]

    Boyer, Edmond

    )" #12;1. Introduction Brazed aluminium heat exchangers are composed of flat tubes on the refrigerant exchangers with round tube, such as charge reduction and higher heat transfer coefficient. But, according are thus not suitable to small-channel heat exchangers. As a consequence, the refrigerant distribution

  16. Technical Information Exchange on Pyrolysis Oil: Potential for...

    Broader source: Energy.gov (indexed) [DOE]

    Renewab;e Heating Oil Substation Fuel in New England Technical Information Exchange on Pyrolysis Oil: Potential for a Renewab;e Heating Oil Substation Fuel in New England This...

  17. Absorption heat pump system

    DOE Patents [OSTI]

    Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

    1984-01-01T23:59:59.000Z

    An improvement in an absorption heat pump cycle is obtained by adding adiabatic absorption and desorption steps to the absorber and desorber of the system. The adiabatic processes make it possible to obtain the highest temperature in the absorber before any heat is removed from it and the lowest temperature in the desorber before heat is added to it, allowing for efficient utilization of the thermodynamic availability of the heat supply stream. The improved system can operate with a larger difference between high and low working fluid concentrations, less circulation losses, and more efficient heat exchange than a conventional system.

  18. Mixing in wicking structures and the use of enhanced mixing within wicks in microchannel devices

    DOE Patents [OSTI]

    Stenkamp, Victoria S. (Richland, WA); TeGrotenhuis, Ward E. (Kennewick, WA); Wegeng, Robert S. (Alexandria, VA)

    2009-06-02T23:59:59.000Z

    Advanced wicking structures and methods utilizing these structures are described. The use of advanced wicking structures can promote rapid mass transfer while maintaining high capillary pressure through the use of small pores. Particularly improved results in fluid contacting processes can be achieved by enhanced mixing within a wicking layer within a microchannel.

  19. An experimental investigation into the dimension-sensitive viscosity of polymer containing lubricant oils in microchannels

    E-Print Network [OSTI]

    Erickson, David

    lubricant oils in microchannels David Erickson a , Fuzhi Lu a , Dongqing Li a,*, Tony White b , Jason Gao b lubrication processes, lubricating oils containing polymer additives are subject to high shear rate through of channel height on the effective viscosity of oil lubricants with two different polymer additives (a radial

  20. Modeling of diffusion of injected electron spins in spin-orbit coupled microchannels

    E-Print Network [OSTI]

    Zarbo, Liviu P.; Sinova, Jairo; Knezevic, I.; Wunderlich, J.; Jungwirth, T.

    2010-01-01T23:59:59.000Z

    We report on a theoretical study of spin dynamics of an ensemble of spin-polarized electrons injected in a diffusive microchannel with linear Rashba and Dresselhaus spin-orbit coupling. We explore the dependence of the spin-precession and spin...

  1. AN ARTIFICIAL NEURAL NETWORK FOR DIMENSIONS AND COST MODELLING OF INTERNAL MICRO-CHANNELS

    E-Print Network [OSTI]

    Lee, Hyowon

    AN ARTIFICIAL NEURAL NETWORK FOR DIMENSIONS AND COST MODELLING OF INTERNAL MICRO Engineering, Dublin City University, Dublin, Ireland ABSTRACT For micro-channel fabrication using laser micro evaluation. Artificial Neural Network (ANN) is one of the numerical methodologies that can be utilised

  2. Proceedings of the Sixth International ASME Conference on Nanochannels, Microchannels and Minichannels June 23-25, 2008, Darmstadt, Germany

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    pattern. Simulation is repeated under different conditions of pressure gradient, void fraction and bubble such as micro heat exchangers and biotechnology systems. The features of extremely large surface-to-volume ratio the lubrication theory for phase change in microlayer region. Fukagata et al. (2007) simulated slug flows

  3. CO2 dissolution in water using long serpentine microchannels

    E-Print Network [OSTI]

    Cubaud, Thomas

    an important role in blood circulation and during gas exchange in the respiratory system.1 The system carbon, and Ruopeng Sun Department of Mechanical Engineering, Stony Brook University, Stony Brook, New York 11794, USA in the liquid plugs.79 When bubbles are diffusive, this mechanism also facilitates gas absorption at the liquid

  4. Method for controlling exhaust gas heat recovery systems in vehicles

    DOE Patents [OSTI]

    Spohn, Brian L.; Claypole, George M.; Starr, Richard D

    2013-06-11T23:59:59.000Z

    A method of operating a vehicle including an engine, a transmission, an exhaust gas heat recovery (EGHR) heat exchanger, and an oil-to-water heat exchanger providing selective heat-exchange communication between the engine and transmission. The method includes controlling a two-way valve, which is configured to be set to one of an engine position and a transmission position. The engine position allows heat-exchange communication between the EGHR heat exchanger and the engine, but does not allow heat-exchange communication between the EGHR heat exchanger and the oil-to-water heat exchanger. The transmission position allows heat-exchange communication between the EGHR heat exchanger, the oil-to-water heat exchanger, and the engine. The method also includes monitoring an ambient air temperature and comparing the monitored ambient air temperature to a predetermined cold ambient temperature. If the monitored ambient air temperature is greater than the predetermined cold ambient temperature, the two-way valve is set to the transmission position.

  5. Fabrication of a Hybrid Microfluidic System Incorporating both Lithographically Patterned Microchannels and a 3D Fiber-Formed Microfluidic Network

    E-Print Network [OSTI]

    Bellan, Leon M.

    A device containing a 3D microchannel network (fabricated using sacrificial melt-spun microfibers) sandwiched between lithographically patterned microfluidic channels offers improved delivery of soluble compounds to a large ...

  6. Proceedings of the Sixth International ASME Conference on Nanochannels, Microchannels and Minichannels June 23-25, 2008, Darmstadt, Germany

    E-Print Network [OSTI]

    Kandlikar, Satish

    Proceedings of the Sixth International ASME Conference on Nanochannels, Microchannels TRANSFER IN MICROSCALE SINGLE PHASE FLOW: A CRITICAL REVIEW Perry L. Young Rochester Institute of Technology PerryLYoung@gmail.com Satish G. Kandlikar Rochester Institute of Technology sgkeme

  7. Thermal Analysis of LANL Ion Exchange Column

    SciTech Connect (OSTI)

    Laurinat, J.E.

    1999-06-16T23:59:59.000Z

    This document reports results from an ion exchange column heat transfer analysis requested by Los Alamos National Laboratory (LANL). The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades.

  8. 8 Ecosystem Exchange 8.3 Introduction

    E-Print Network [OSTI]

    of momentum, sensible heat, H, latent heat, E, and carbon dioxide, Fc, and the energy budget. 8.4 Storage and carbon dioxide are described. Patterns of these exchanges are explained in relation to appropriate variables and controlling factors. The storage of mass and energy is presented first, followed by the fluxes

  9. Frostless heat pump having thermal expansion valves

    DOE Patents [OSTI]

    Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN)

    2002-10-22T23:59:59.000Z

    A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

  10. Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers

    E-Print Network [OSTI]

    Muraya, Norman K.

    Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed...

  11. Agriculture on Exchange InternationalExchangeProgram

    E-Print Network [OSTI]

    Viglas, Anastasios

    Agriculture on Exchange InternationalExchangeProgram Students enrolled in courses offered through the Faculty of Agriculture and Environment are welcome to apply for exchange. However, to ensure that you Academic Adviser before submitting an exchange application. Undergraduate Agriculture students normally go

  12. Technical Note Solution of periodic heating problems by the

    E-Print Network [OSTI]

    Barber, James R.

    .R. Barber * Department of Mechanical Engineering, 2250 GG Brown Laboratory, University of Michigan, Ann in sliding solids [2], regenerative heat exchangers [3], solar heating systems [4] and heat con- duction

  13. Hear Exchange Assembly

    DOE Patents [OSTI]

    Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc (Princeton, NJ); Miller, Jeffrey (Rocky Hill, NJ); Tonon, Thomas S. (Princeton, NJ)

    2003-05-27T23:59:59.000Z

    A heat exchange assembly comprises a plurality of plates disposed in a spaced-apart arrangement, each of the plurality of plates includes a plurality of passages extending internally from a first end to a second end for directing flow of a heat transfer fluid in a first plane, a plurality of first end-piece members equaling the number of plates and a plurality of second end-piece members also equaling the number of plates, each of the first and second end-piece members including a recessed region adapted to fluidly connect and couple with the first and second ends of the plate, respectively, and further adapted to be affixed to respective adjacent first and second end-piece members in a stacked formation, and each of the first and second end-piece members further including at least one cavity for enabling entry of the heat transfer fluid into the plate, exit of the heat transfer fluid from the plate, or 180.degree. turning of the fluid within the plate to create a serpentine-like fluid flow path between points of entry and exit of the fluid, and at least two fluid conduits extending through the stacked plurality of first and second end-piece members for providing first fluid connections between the parallel fluid entry points of adjacent plates and a fluid supply inlet, and second fluid connections between the parallel fluid exit points of adjacent plates and a fluid discharge outlet so that the heat transfer fluid travels in parallel paths through each respective plate.

  14. A Lightweight Material for Heat Exchange Applications

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    (UHMW-PE) fiber and sheet production that will result in a thermally conductive plastic material. A number of lab-scale studies have shown that thermal conductivity is im-...

  15. COMPACT HEAT EXCHANGERS FOR CONDENSATION APPLICATIONS: YESTERDAY,

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed New Substation Sites Proposed Route BTRIC CNMSMethanoliVP-^"^^?COMMISSIONERS

  16. Industrial Plate Exchangers Heat Recovery and Fouling

    E-Print Network [OSTI]

    Cross, P. H.

    1981-01-01T23:59:59.000Z

    (still)for separation of light oil from the wash oil,which is then returned to absorber tower.The debenzolised wash 0 0 oil is cooled indirectly to 20 C/30 C before returning to the absorber tower. This is toprevent condensation of water from the gas... Industrial Energy Technology Conference Houston, TX, April 26-29, 1981 -- c.O.G. LIGHT OIL SCRUBBER COKE OVEN GAS(C.O.G,J BENZINE COOLING WATER BENZOLISED ~WASH OILSTRIPPER CONVENTIONAL LIGHT OIL RECOVERY PLANT DEBENZOLISED WASH OIL / COOLING WATER...

  17. A Lightweight Material for Heat Exchange Applications

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up from theDepartment(October-DecemberBased onIn-CylinderContinuous Processing of High

  18. Building-Integrated Heat & Moisture Exchange

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 2015 < prevBuilding the Distribution Grid of the

  19. Miniaturized Air-to-Refrigerant Heat Exchangers

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d F S i DOE TribaltheMy nameMid-LevelMidwestSept. 2005 | Department

  20. Sabdia's Radial Flow Air Bearing Heat Exchanger

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l LPROJECTS IN7 RoadmapProgram 2013: AlaskaSTEM0-1FACT SHEET: SALTSandia's

  1. Sandia National Laboratories: Heat Exchanger Development

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik Spoerke SSLS Exhibit at ExploraGlobal SandiaVermontFacilityHeFl Flow

  2. Ruggedized microchannel-cooled laser diode array with self-aligned microlens

    DOE Patents [OSTI]

    Freitas, Barry L.; Skidmore, Jay A.

    2003-11-11T23:59:59.000Z

    A microchannel-cooled, optically corrected, laser diode array is fabricated by mounting laser diode bars onto Si surfaces. This approach allows for the highest thermal impedance, in a ruggedized, low-cost assembly that includes passive microlens attachment without the need for lens frames. The microlensed laser diode array is usable in all solid-state laser systems that require efficient, directional, narrow bandwidth, high optical power density pump sources.

  3. Aluminum Nitride Micro-Channels Grown via Metal Organic Vapor Phase Epitaxy for MEMs Applications

    SciTech Connect (OSTI)

    Rodak, L.E.; Kuchibhatla, S.; Famouri, P.; Ting, L.; Korakakis, D.

    2008-01-01T23:59:59.000Z

    Aluminum nitride (AlN) is a promising material for a number of applications due to its temperature and chemical stability. Furthermore, AlN maintains its piezoelectric properties at higher temperatures than more commonly used materials, such as Lead Zirconate Titanate (PZT) [1, 2], making AlN attractive for high temperature micro and nanoelectromechanical (MEMs and NEMs) applications including, but not limited to, high temperature sensors and actuators, micro-channels for fuel cell applications, and micromechanical resonators. This work presents a novel AlN micro-channel fabrication technique using Metal Organic Vapor Phase Epitaxy (MOVPE). AlN easily nucleates on dielectric surfaces due to the large sticking coefficient and short diffusion length of the aluminum species resulting in a high quality polycrystalline growth on typical mask materials, such as silicon dioxide and silicon nitride [3,4]. The fabrication process introduced involves partially masking a substrate with a silicon dioxide striped pattern and then growing AlN via MOVPE simultaneously on the dielectric mask and exposed substrate. A buffered oxide etch is then used to remove the underlying silicon dioxide and leave a free standing AlN micro-channel. The width of the channel has been varied from 5 m to 110 m and the height of the air gap from 130 nm to 800 nm indicating the stability of the structure. Furthermore, this versatile process has been performed on (111) silicon, c-plane sapphire, and gallium nitride epilayers on sapphire substrates. Reflection High Energy Electron Diffraction (RHEED), Atomic Force Microscopy (AFM), and Raman measurements have been taken on channels grown on each substrate and indicate that the substrate is influencing the growth of the AlN micro-channels on the SiO2 sacrificial layer.

  4. Note: A timing micro-channel plate detector with backside fast preamplifier

    SciTech Connect (OSTI)

    Wang, Wei [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China) [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Yu, Deyang, E-mail: d.yu@impcas.ac.cn; Lu, Rongchun; Liu, Junliang; Cai, Xiaohong [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)] [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2014-03-15T23:59:59.000Z

    A timing micro-channel plate detector with a backside double-channel fast preamplifier was developed to avoid distortion during signal propagation from the anode to the preamplifier. The mechanical and electronic structure is described. The detector including its backside preamplifier is tested by a {sup 241}Am ?-source and a rise time of ?2 ns with an output background noise of 4 mV{sub rms} was achieved.

  5. Co-current airwater two-phase ow patterns in vertical triangular microchannels

    E-Print Network [OSTI]

    Zhao, Tianshou

    Co-current air±water two-phase ¯ow patterns in vertical triangular microchannels T.S. Zhao * , Q Characteristics of co-current upward air±water two-phase ¯ow patterns in vertical equilateral triangular channels tubes has been re- ported. Damianides (1987) experimentally studied the two-phase ¯ow of air±water

  6. Open-loop heat-recovery dryer

    DOE Patents [OSTI]

    TeGrotenhuis, Ward Evan

    2013-11-05T23:59:59.000Z

    A drying apparatus is disclosed that includes a drum and an open-loop airflow pathway originating at an ambient air inlet, passing through the drum, and terminating at an exhaust outlet. A passive heat exchanger is included for passively transferring heat from air flowing from the drum toward the exhaust outlet to air flowing from the ambient air inlet toward the drum. A heat pump is also included for actively transferring heat from air flowing from the passive heat exchanger toward the exhaust outlet to air flowing from the passive heat exchanger toward the drum. A heating element is also included for further heating air flowing from the heat pump toward the drum.

  7. Experimental investigations about using the earth as a heat storage medium and as a heat source for heat pumps. Final report

    SciTech Connect (OSTI)

    Nievergeld, P.; Koppenol, A.; van der Brugh, J.

    1981-03-01T23:59:59.000Z

    The main purpose of the experimental investigation was to verify the computer program for calculating horizontal earth heat exchangers under practical conditions. The heat extraction from and the temperature distribution in the earth around the tubes of a horizontal earth heat exchanger were measured.

  8. Low Cost Manufacturable Microchannel Systems for Passive PEM Water

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10IO1OP001Long-Term Storage of Cesium1940sofof10Management |

  9. Low-Cost Manufacturable Microchannel Systems for Passive PEM Water

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe10IO1OP001Long-Termpaul_fini@cree.com CREE

  10. The CO2 Reduction Potential of Combined Heat and Power in California's Commercial Buildings

    E-Print Network [OSTI]

    Stadler, Michael

    2010-01-01T23:59:59.000Z

    heat exchangers, solar thermal collectors, absorptioncells; photovoltaics (PV) and solar thermal collectors; for application of solar thermal and recovered heat to end-

  11. The CO2 Reduction Potential of Combined Heat and Power in California's Commercial Buildings

    E-Print Network [OSTI]

    Stadler, Michael

    2010-01-01T23:59:59.000Z

    P.C. (2001), Introduction to Advancd Batteries for EmergingPV) and solar thermal collectors; conventional batteries,flow batteries, and heat storage; heat exchangers for

  12. Model Based Diagnosis of an Air Source Heat Pump; Modellbaserad Diagnos av en Luftvrmepump.

    E-Print Network [OSTI]

    Alfredsson, Sandra

    2011-01-01T23:59:59.000Z

    ?? The purpose of a heat pump is to control the temperature of an enclosed space. This is done by using heat exchange with a (more)

  13. Task II: evaluation of heat-exchanger and turbine materials for use in a coal-fired fluidized-bed-combustion environment. Final report, July 1, 1976-July 31, 1980

    SciTech Connect (OSTI)

    Not Available

    1981-09-30T23:59:59.000Z

    Specific alloys were tested as in-bed and above-bed heat exchanger materials in the fireside environment of a pressurized fluidized bed coal combustor (PFBCC). Corrosion conditions on the alloys exposed to normal and very low oxygen pressures in the presence of calcium sulfate deposits were simulated. Bayonet-type specimen probes of selected alloys were exposed in the Exxon Miniplant at probe control temperatures representative of conventional steam, advanced steam, helium and liquid metal energy conversion cycles. Corrosion/erosion testing of the air cooled, welded samples consisted of a 117-hour shakedown run followed by an incremental 1000-hour exposure. Metallurgical analyses were run on removed specimens. The test matrix for in-bed and above-bed exposure was: 1050/sup 0/F (566/sup 0/C): 2.25 Cr-1Mo and 9Cr-1Mo steels (in-bed only); 1200/sup 0/F (649/sup 0/C): 304 SS and Incoloy-800; 1400/sup 0/F (760/sup 0/C): Incoloy-800 and Hastelloy-X; and 1600/sup 0/F (871/sup 0/C); Hastelloy-X and Haynes-188. Subscale sulfides formed in most of the alloys. The most severe corrosion was noted in the ferritic 2.25Cr-1Mo and 9Cr-1Mo steels at a nominal control temperature of 1050/sup 0/F (566/sup 0/C) and in Hastelloy-X at 1400/sup 0/F (760/sup 0/C) exposed in-bed. The best overall behavior of in-bed alloys was observed for Incoloy-800, which had a maximum metal loss of about .007 in (.18 mm) in 1117 hours of exposure at both 1200/sup 0/F (649/sup 0/C) and 1400/sup 0/F (760/sup 0/C) but averaged more nearly .001 in (.025 mm) to .002 in (.051 mm) and in Haynes-188 which showed maximum wall thinning of less than .003 in (.076 mm) at 1600/sup 0/F (871/sup 0/C) in the longest time exposure.

  14. Heat pump system with selective space cooling

    DOE Patents [OSTI]

    Pendergrass, J.C.

    1997-05-13T23:59:59.000Z

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

  15. Heat pump system with selective space cooling

    DOE Patents [OSTI]

    Pendergrass, Joseph C. (Gainesville, GA)

    1997-01-01T23:59:59.000Z

    A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

  16. Experimental Investigation of the Effect Of Zeolite Coating Thickness on the Performance of a Novel Zeolite-Water Adsorption Heat Pump Module

    E-Print Network [OSTI]

    Dawoud, B.; Hofle, P.; Chmielewski, S.

    2010-01-01T23:59:59.000Z

    A novel zeolite-water absorption heat pump module comprising an adsorber, an evaporator and a condenser heat exchanger as well as a module non-return valve in a hermetically sealed vessel is introduced. The investigated adsorber heat exchanger...

  17. Microchannel formation in seaice as habitat for microalgae

    E-Print Network [OSTI]

    K. Morawetz; S. Thoms; B. Kutschan

    2014-07-08T23:59:59.000Z

    The formation of saline brine channels in seaice is described by two coupled order parameters, the tetrahedricity as structure of ice and the salinity. Their evolution equations follow from a Ginzburg-Landau-functional in the form of a phase-field theory conserving salinity. The stability analysis provides the phase diagram in terms of two parameters, one describing the velocity of the freezing process and the other one characterizing the velocity of structure formation. In thermodynamics these parameters determine the supercooling or superheating region and the specific heat respectively. In contrast to the Turing model the diffusivity does not enter this phase diagram but determines only the structure size. The numerical solution shows a microstructure formation of brine inclusions in agreement with the measured samples dependent on the salinity and temperature.

  18. Energy-Exchange Project

    SciTech Connect (OSTI)

    Not Available

    1982-04-01T23:59:59.000Z

    The purpose of the study was to determine what energy savings can be achieved by coordinating the resources and requirements of two facilities, the 26th Ward Water Pollution Control Plant (WPCP) and a housing development named Starrett City with its own total energy system. It was determined that three energy exchange options were economically and technically feasible. These include: the transfer of digester gas produced at the 26th Ward to the boilers at the Starrett City's total energy plant (TEP); the transfer of hot water heated at the TEP to the 26th Ward for space and process heating; and the transfer of coal effluent waste water from the 26th Ward to the condenser cooling systems at the TEP. Technical information is presented to support the findings. The report addresses those tasks of the statement of work dedicated to data acquisition, analysis, and energy conservation strategies internal to the Starrett City TEP and the community it supplies as well as to the 26th Ward WPCP. (MCW)

  19. The effects of airflow modulation and multi-stage defrost on the performance of an air source heat pump

    E-Print Network [OSTI]

    Payne, William Vance

    1992-01-01T23:59:59.000Z

    . This transfer of heat energy from a low temperature ambient to the high temperature conditioned space is accomplished by the input of electrical energy to the compressor. During the heating season, the heat pump transfers heat energy from the low temperature... pump refrigeration circuit includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, an expansion device, and fans to transfer heat energy from a low temperature heat energy source to a higher temperature heat energy sink...

  20. ME 339 Heat Transfer ABET EC2000 syllabus

    E-Print Network [OSTI]

    Ben-Yakar, Adela

    ME 339­ Heat Transfer Page 1 ABET EC2000 syllabus ME 339 ­ Heat Transfer Spring 2010 Required convection; radiation; introduction to phase change heat transfer and to heat exchangers. Prerequisite(s): ME, Fundamentals of Heat and Mass Transfer, 6th ed., Wiley Other Required Material: NA Course Objectives