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Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

Corrosive resistant heat exchanger  

DOE Patents [OSTI]

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.

Richlen, Scott L. (Annandale, VA)

1989-01-01T23:59:59.000Z

2

Heat exchanger  

DOE Patents [OSTI]

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.

Brackenbury, P.J.

1983-12-08T23:59:59.000Z

3

Heat exchanger  

DOE Patents [OSTI]

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.

Brackenbury, Phillip J. (Richland, WA)

1986-01-01T23:59:59.000Z

4

Segmented heat exchanger  

DOE Patents [OSTI]

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.

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

5

Heat pipe array heat exchanger  

DOE Patents [OSTI]

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.

Reimann, Robert C. (Lafayette, NY)

1987-08-25T23:59:59.000Z

6

Woven heat exchanger  

DOE Patents [OSTI]

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.

Piscitella, R.R.

1984-07-16T23:59:59.000Z

7

Direct fired heat exchanger  

SciTech Connect (OSTI)

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.

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

1986-01-01T23:59:59.000Z

8

Active microchannel heat exchanger  

DOE Patents [OSTI]

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.

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

9

Heat and mass exchanger  

DOE Patents [OSTI]

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.

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

2007-09-18T23:59:59.000Z

10

Heat and mass exchanger  

DOE Patents [OSTI]

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.

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

2011-06-28T23:59:59.000Z

11

Thermoelectric heat exchange element  

DOE Patents [OSTI]

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.

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

2007-08-14T23:59:59.000Z

12

A corrosive resistant heat exchanger  

DOE Patents [OSTI]

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.

Richlen, S.L.

1987-08-10T23:59:59.000Z

13

Radial flow heat exchanger  

DOE Patents [OSTI]

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.

Valenzuela, Javier (Hanover, NH)

2001-01-01T23:59:59.000Z

14

Proceedings: Heat exchanger workshop  

SciTech Connect (OSTI)

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.

Not Available

1987-07-01T23:59:59.000Z

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]

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...

Siegell, J. H.

17

High Temperature Heat Exchanger Project  

SciTech Connect (OSTI)

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

Anthony E. Hechanova, Ph.D.

2008-09-30T23:59:59.000Z

18

Modular heat exchanger  

DOE Patents [OSTI]

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.

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

1981-03-03T23:59:59.000Z

19

Heat exchanger using graphite foam  

DOE Patents [OSTI]

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.

Campagna, Michael Joseph; Callas, James John

2012-09-25T23:59:59.000Z

20

Heat exchanger with ceramic elements  

DOE Patents [OSTI]

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.

Corey, John A. (North Troy, NY)

1986-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Ceramic heat exchanger  

DOE Patents [OSTI]

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.

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

1998-06-16T23:59:59.000Z

22

Ceramic heat exchanger  

DOE Patents [OSTI]

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.

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

23

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...

24

Second Law Optimization of Heat Exchangers  

E-Print Network [OSTI]

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...

Witte, L. C.

25

Condensing Heat Exchangers Optimize Steam Boilers  

E-Print Network [OSTI]

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...

Sullivan, B.; Sullivan, P. A.

1983-01-01T23:59:59.000Z

26

Synergistic diffuser/heat-exchanger design  

E-Print Network [OSTI]

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 ...

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

2004-01-01T23:59:59.000Z

27

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...

28

THERMOSIPHON WATER HEATERS WITH HEAT EXCHANGERS  

E-Print Network [OSTI]

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*

Mertol, Atila

2012-01-01T23:59:59.000Z

29

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

30

NGNP Process Heat Utilization: Liquid Metal Phase Change Heat Exchanger  

SciTech Connect (OSTI)

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.

Piyush Sabharwall; Mike Patterson; Vivek Utgikar; Fred Gunnerson

2008-09-01T23:59:59.000Z

31

Heat exchanger for power generation equipment  

DOE Patents [OSTI]

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.

Nirmalan, Nirm Velumylm; Bowman, Michael John

2005-06-14T23:59:59.000Z

32

Thermodynamic Efficiency of Heat Exchange Devices  

E-Print Network [OSTI]

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...

Witte, L. C.; Shamsundar, N.

1982-01-01T23:59:59.000Z

33

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

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.

Koplow, Jeffrey P. (San Ramon, CA)

2012-07-24T23:59:59.000Z

34

Heat exchanger device and method for heat removal or transfer  

DOE Patents [OSTI]

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.

Koplow, Jeffrey P

2013-12-10T23:59:59.000Z

35

Heat exchanger with transpired, highly porous fins  

DOE Patents [OSTI]

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.

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

2002-01-01T23:59:59.000Z

36

Integrated Approach to Revamping Heat Exchangers Networks  

E-Print Network [OSTI]

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...

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

37

Heat Exchanger Technologies for Distillation Columns  

E-Print Network [OSTI]

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...

Polley, G. T.

38

IntroductiontoProcessEngineering(PTG) 4. Heat exchangers;  

E-Print Network [OSTI]

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

Zevenhoven, Ron

39

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

40

Heat Exchanger With Internal Pin Elements  

DOE Patents [OSTI]

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.

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

2004-01-13T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

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...

42

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network [OSTI]

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...

Singh, K. P.

1979-01-01T23:59:59.000Z

43

Heat exchanger for coal gasification process  

DOE Patents [OSTI]

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.

Blasiole, George A. (Greensburg, PA)

1984-06-19T23:59:59.000Z

44

Modeling particle deposition on HVAC heat exchangers  

SciTech Connect (OSTI)

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.

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

2002-01-01T23:59:59.000Z

45

Heat exchanger containing a component capable of discontinuous movement  

DOE Patents [OSTI]

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.

Wilson, David Gordon (Winchester, MA)

2002-01-01T23:59:59.000Z

46

Heat exchanger containing a component capable of discontinuous movement  

DOE Patents [OSTI]

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.

Wilson, David Gordon

2001-04-17T23:59:59.000Z

47

Heat exchanger containing a component capable of discontinuous movement  

DOE Patents [OSTI]

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.

Wilson, D.G.

1993-11-09T23:59:59.000Z

48

Multidimensional numerical modeling of heat exchangers. [LMFBR  

SciTech Connect (OSTI)

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).

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

1982-01-01T23:59:59.000Z

49

Carbon nanotube heat-exchange systems  

DOE Patents [OSTI]

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).

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

2008-11-11T23:59:59.000Z

50

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

51

Modeling of Heat Transfer in Geothermal Heat Exchangers  

E-Print Network [OSTI]

, 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...

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

2006-01-01T23:59:59.000Z

52

Fouling of HVAC fin and tube heat exchangers  

E-Print Network [OSTI]

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

Siegel, Jeffrey; Carey, Van P.

2001-01-01T23:59:59.000Z

53

Using Plate Heat Exchangers to Increase Energy Efficiency  

E-Print Network [OSTI]

"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...

Bailey, K.

54

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...

55

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...

56

Dealing with Uncertainties During Heat Exchanger Design  

E-Print Network [OSTI]

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...

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

57

Heat exchanger support apparatus in a fluidized bed  

DOE Patents [OSTI]

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.

Lawton, Carl W. (West Hartford, CT)

1982-01-01T23:59:59.000Z

58

Heat Pump Cycle with Solution Circuit and Internal Heat Exchange  

E-Print Network [OSTI]

-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...

Radermacher, R.

59

Microchannel Heat Exchangers with Carbon Dioxide  

SciTech Connect (OSTI)

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.

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

2001-09-15T23:59:59.000Z

60

Design and Development of a Plastic Film Heat Exchanger  

E-Print Network [OSTI]

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...

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

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

SciTech Connect (OSTI)

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.

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

2008-11-01T23:59:59.000Z

62

Condensation in horizontal heat exchanger tubes  

SciTech Connect (OSTI)

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)

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

63

Diffusion-Welded Microchannel Heat Exchanger for Industrial Processes  

SciTech Connect (OSTI)

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.

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

2013-03-01T23:59:59.000Z

64

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

E-Print Network [OSTI]

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...

Gonzalez, Jose Antonio

1993-01-01T23:59:59.000Z

65

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

E-Print Network [OSTI]

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

Kandlikar, Satish

66

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

E-Print Network [OSTI]

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...

Chen, Y.; Zhao, J.

2006-01-01T23:59:59.000Z

67

Temperature profile of the infrared image Heat exchange between  

E-Print Network [OSTI]

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

Jaehne, Bernd

68

Heat exchanger for fuel cell power plant reformer  

DOE Patents [OSTI]

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.

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

69

Control Dewar Subcooler Heat Exchanger Calculations  

SciTech Connect (OSTI)

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.

Rucinski, R.; /Fermilab

1993-10-04T23:59:59.000Z

70

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

SciTech Connect (OSTI)

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)

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

71

Automatic Tube Cleaning Systems for Condensers and Heat Exchangers  

E-Print Network [OSTI]

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...

Someah, K.

72

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

73

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

SciTech Connect (OSTI)

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.

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

1983-01-01T23:59:59.000Z

74

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

E-Print Network [OSTI]

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

Thole, Karen A.

75

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

76

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

77

Direct-contact closed-loop heat exchanger  

DOE Patents [OSTI]

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.

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

1984-01-01T23:59:59.000Z

78

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

DOE Patents [OSTI]

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.

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

1994-11-29T23:59:59.000Z

79

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

E-Print Network [OSTI]

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...

Chen, Y.; Zhang, J.

2006-01-01T23:59:59.000Z

80

Microchannel crossflow fluid heat exchanger and method for its fabrication  

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Microchannel crossflow fluid heat exchanger and method for its fabrication  

DOE Patents [OSTI]

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.

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

1985-05-14T23:59:59.000Z

82

Microchannel crossflow fluid heat exchanger and method for its fabrication  

DOE Patents [OSTI]

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.

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

1982-08-31T23:59:59.000Z

83

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

SciTech Connect (OSTI)

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.

Panchal, C.B.

1993-07-01T23:59:59.000Z

84

Heat exchanger and water tank arrangement for passive cooling system  

DOE Patents [OSTI]

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.

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

1993-11-30T23:59:59.000Z

85

Acoustically enhanced heat exchange and drying apparatus  

DOE Patents [OSTI]

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.

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

1987-07-10T23:59:59.000Z

86

SILICON CARBIDE CERAMICS FOR COMPACT HEAT EXCHANGERS  

SciTech Connect (OSTI)

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

DR. DENNIS NAGLE; DR. DAJIE ZHANG

2009-03-26T23:59:59.000Z

87

Evaluation of fluid bed heat exchanger optimization parameters. Final report  

SciTech Connect (OSTI)

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.

Not Available

1980-03-01T23:59:59.000Z

88

Process Heat Exchanger Options for the Advanced High Temperature Reactor  

SciTech Connect (OSTI)

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.

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

2011-06-01T23:59:59.000Z

89

Process Heat Exchanger Options for Fluoride Salt High Temperature Reactor  

SciTech Connect (OSTI)

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.

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

2011-04-01T23:59:59.000Z

90

Energy effectiveness of simultaneous heat and mass exchange devices  

E-Print Network [OSTI]

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 ...

Narayan, G. Prakash

2010-01-01T23:59:59.000Z

91

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

E-Print Network [OSTI]

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...

Gaskill, Travis

2012-02-14T23:59:59.000Z

92

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

E-Print Network [OSTI]

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...

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

1994-01-01T23:59:59.000Z

93

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

E-Print Network [OSTI]

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...

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

94

Acoustically enhanced heat exchange and drying apparatus  

DOE Patents [OSTI]

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.

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

1989-01-01T23:59:59.000Z

95

Heat Exchangers for the Next Generation of Nuclear Reactors  

SciTech Connect (OSTI)

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)

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

96

Self-defrosting recuperative air-to-air heat exchanger  

DOE Patents [OSTI]

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.

Drake, R.L.

1993-12-28T23:59:59.000Z

97

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents [OSTI]

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.

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

1984-08-30T23:59:59.000Z

98

Fast reactor power plant design having heat pipe heat exchanger  

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

99

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

E-Print Network [OSTI]

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

McCarthy, John E.

100

Heat Exchangers for Solar Water Heating Systems | Department of Energy  

Energy Savers [EERE]

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Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
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101

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

SciTech Connect (OSTI)

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.

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

2011-04-01T23:59:59.000Z

102

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

103

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

104

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

DOE Patents [OSTI]

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.

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

1996-12-03T23:59:59.000Z

105

Liquid Salt Heat Exchanger Technology for VHTR Based Applications  

SciTech Connect (OSTI)

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.

Mark Anderson; Kumar Sridhara; Todd Allen; Per Peterson

2012-10-11T23:59:59.000Z

106

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

SciTech Connect (OSTI)

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.

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

2011-01-01T23:59:59.000Z

107

Design of Heat Exchanger for Heat Recovery in CHP Systems  

E-Print Network [OSTI]

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...

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

108

Materials, Turbomachinery and Heat Exchangers for Supercritical CO2 Systems  

SciTech Connect (OSTI)

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.

Mark Anderson; Greg Nellis; Michael Corradini

2012-10-19T23:59:59.000Z

109

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

E-Print Network [OSTI]

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

Boyd, Sylke

110

Heat treatment of exchangers to remove coke  

SciTech Connect (OSTI)

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.

Turner, J.D.

1990-02-20T23:59:59.000Z

111

Diffusion Welding of Compact Heat Exchangers for Nuclear Applications  

SciTech Connect (OSTI)

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.

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

2012-06-01T23:59:59.000Z

112

Sludge, fuel degradation and reducing fouling on heat exchangers  

SciTech Connect (OSTI)

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.

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

1992-02-01T23:59:59.000Z

113

Heat Exchanger Fouling- Prediction, Measurement and Mitigation  

E-Print Network [OSTI]

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...

Peterson, G. R.

114

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.

115

Method of fabricating a heat exchanger for Stirling engine  

SciTech Connect (OSTI)

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.

Rao, V.D.

1980-10-28T23:59:59.000Z

116

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

SciTech Connect (OSTI)

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.

Mittereder, N.; Poerschke, A.

2013-11-01T23:59:59.000Z

117

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

SciTech Connect (OSTI)

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)

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

118

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

E-Print Network [OSTI]

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

Fernández de Córdoba, Pedro

119

Advanced Rotating Heat Exchangers | Department of Energy  

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

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120

Xenon Recirculation-Purification with a Heat Exchanger  

E-Print Network [OSTI]

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.

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

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

DOE Patents [OSTI]

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.

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

1998-07-21T23:59:59.000Z

122

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

DOE Patents [OSTI]

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.

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

1998-07-21T23:59:59.000Z

123

Integral collector storage system with heat exchange apparatus  

DOE Patents [OSTI]

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.

Rhodes, Richard O.

2004-04-20T23:59:59.000Z

124

Condensing Heat Exchanger for Optimization of Energy Efficiency  

E-Print Network [OSTI]

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...

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

125

Finned Tube With Vortex Generators For A Heat Exchanger.  

DOE Patents [OSTI]

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.

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

2005-12-20T23:59:59.000Z

126

GEA Heat Exchangers GEA Searle Cooler and Condensing Unit Ranges  

E-Print Network [OSTI]

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

Frandsen, Søren

127

Heat exchanger efficiently operable alternatively as evaporator or condenser  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

128

Novel Power Electronics Three-Dimensional Heat Exchanger: Preprint  

SciTech Connect (OSTI)

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.

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

2014-08-01T23:59:59.000Z

129

Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor  

SciTech Connect (OSTI)

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.

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

2012-06-01T23:59:59.000Z

130

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

SciTech Connect (OSTI)

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.

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

131

Design of compact intermediate heat exchangers for gas cooled fast reactors  

E-Print Network [OSTI]

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 ...

Gezelius, Knut, 1978-

2004-01-01T23:59:59.000Z

132

Heat Exchanger Monitoring and Its Application to Cleaning and Antifoulant Use  

E-Print Network [OSTI]

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...

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

1983-01-01T23:59:59.000Z

133

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

DOE Patents [OSTI]

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.

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

2013-07-02T23:59:59.000Z

134

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...

135

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...

136

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

DOE Patents [OSTI]

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.

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

2012-08-07T23:59:59.000Z

137

Thermal performance of direct contact heat exchangers for mixed hydrocarbons  

SciTech Connect (OSTI)

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.

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

1985-01-01T23:59:59.000Z

138

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

SciTech Connect (OSTI)

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.

Baer, B.F.

1984-12-04T23:59:59.000Z

139

Energy Recovery By Direct Contact Gas-Liquid Heat Exchange  

E-Print Network [OSTI]

-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...

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

140

Microcomputer analysis of regenerative heat exchangers for oscillating flow  

SciTech Connect (OSTI)

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.

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

1987-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Compact Ceramic Heat Exchangers for Corrosive Waste Gas Applications  

E-Print Network [OSTI]

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...

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

1982-01-01T23:59:59.000Z

142

A Plastic-Core Compact Heat Exchanger for Energy Conservation  

E-Print Network [OSTI]

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...

Lazaridis, A.; Rafailidis, E.

143

Horizontal Heat Exchanger Design and Analysis for Passive Heat Removal Systems  

SciTech Connect (OSTI)

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.

Vierow, Karen

2005-08-29T23:59:59.000Z

144

Fouling of HVAC fin and tube heat exchangers  

SciTech Connect (OSTI)

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.

Siegel, Jeffrey; Carey, Van P.

2001-07-01T23:59:59.000Z

145

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

SciTech Connect (OSTI)

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.

Davidson, J.H.

1998-06-01T23:59:59.000Z

146

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

147

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

E-Print Network [OSTI]

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

Yu, Lisan

148

MULTIPLE POLLUTANT REMOVAL USING THE CONDENSING HEAT EXCHANGER  

SciTech Connect (OSTI)

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.

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

1998-06-01T23:59:59.000Z

149

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

E-Print Network [OSTI]

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...

Yu, Kun

2014-05-08T23:59:59.000Z

150

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:...

151

Xenon Recirculation-Purification with a Heat Exchanger  

E-Print Network [OSTI]

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...

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

152

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

E-Print Network [OSTI]

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

Oak Ridge National Laboratory

153

Aging management guideline for commercial nuclear power plants - heat exchangers  

SciTech Connect (OSTI)

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.

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

1994-06-01T23:59:59.000Z

154

Integrated heat exchanger design for a cryogenic storage tank  

SciTech Connect (OSTI)

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.

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

155

Performance studies of a solar energy storing heat exchanger  

SciTech Connect (OSTI)

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.

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

1988-01-01T23:59:59.000Z

156

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

E-Print Network [OSTI]

#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

Oak Ridge National Laboratory

157

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

E-Print Network [OSTI]

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

Thole, Karen A.

158

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

E-Print Network [OSTI]

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

Thole, Karen A.

159

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

SciTech Connect (OSTI)

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.

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

160

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

E-Print Network [OSTI]

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...

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

162

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

E-Print Network [OSTI]

. 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

Skogestad, Sigurd

163

Continuation of Studies on Development of ODS Heat Exchanger Tubing  

SciTech Connect (OSTI)

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.

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

2008-04-15T23:59:59.000Z

164

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

SciTech Connect (OSTI)

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.

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

2013-09-01T23:59:59.000Z

165

Erosion of heat exchanger tubes in fluidized beds  

SciTech Connect (OSTI)

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.

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

1991-01-01T23:59:59.000Z

166

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

SciTech Connect (OSTI)

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.

Hirose, Yasuo; Kaji, Hitoshi; Arai, Norio

1998-07-01T23:59:59.000Z

167

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...

168

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

SciTech Connect (OSTI)

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.

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

2004-04-06T23:59:59.000Z

169

Heat Transfer Enhancement for Finned-tube Heat Exchangers with Winglets  

SciTech Connect (OSTI)

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%.

O'Brien, James Edward; Sohal, Manohar Singh

2000-11-01T23:59:59.000Z

170

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

SciTech Connect (OSTI)

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.

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

2002-08-01T23:59:59.000Z

171

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

E-Print Network [OSTI]

??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)

Latcham, Jacob G. (Jacob Greco)

2009-01-01T23:59:59.000Z

172

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

E-Print Network [OSTI]

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 ...

Latcham, Jacob G. (Jacob Greco)

2009-01-01T23:59:59.000Z

173

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

E-Print Network [OSTI]

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...

Parker, Brandon DeWayne

1995-01-01T23:59:59.000Z

174

Deposition of biological aerosols on HVAC heat exchangers  

SciTech Connect (OSTI)

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.

Siegel, Jeffrey; Walker, Ian

2001-09-01T23:59:59.000Z

175

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

E-Print Network [OSTI]

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

Al-Shayea, Naser Abdul-Rahman

176

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

SciTech Connect (OSTI)

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.

Piyush Sabharwall

2011-09-01T23:59:59.000Z

177

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

SciTech Connect (OSTI)

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.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01T23:59:59.000Z

178

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]

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...

Umrigar, Eric Dara

2014-05-01T23:59:59.000Z

179

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

E-Print Network [OSTI]

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...

Fullerton, Tracy

2012-02-14T23:59:59.000Z

180

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

SciTech Connect (OSTI)

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.

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

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...

Richlen, S. L.

182

The Role of Filtration in Maintaining Clean Heat Exchanger Coils  

SciTech Connect (OSTI)

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.

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

2004-06-30T23:59:59.000Z

183

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

SciTech Connect (OSTI)

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.

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

1980-06-01T23:59:59.000Z

184

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

DOE Patents [OSTI]

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.

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

1996-11-05T23:59:59.000Z

185

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

E-Print Network [OSTI]

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

Paris-Sud XI, Universit de

186

Ground heat exchanger design for direct geothermal energy systems .  

E-Print Network [OSTI]

??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)

COLLS, STUART

2013-01-01T23:59:59.000Z

187

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

SciTech Connect (OSTI)

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.

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

188

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

SciTech Connect (OSTI)

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.

Schulze, K.H.

1996-01-01T23:59:59.000Z

189

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

SciTech Connect (OSTI)

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.

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

1996-12-31T23:59:59.000Z

190

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

SciTech Connect (OSTI)

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

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

2011-12-01T23:59:59.000Z

191

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

SciTech Connect (OSTI)

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.

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

1985-11-01T23:59:59.000Z

192

Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties  

SciTech Connect (OSTI)

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.

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

2011-06-10T23:59:59.000Z

193

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]

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

Engineering, Barber-Nicholas

2011-01-01T23:59:59.000Z

194

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

E-Print Network [OSTI]

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...

Westheimer, David Thomas

2000-01-01T23:59:59.000Z

195

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

E-Print Network [OSTI]

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

Mertol, A.

2013-01-01T23:59:59.000Z

196

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...

197

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...

198

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

199

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

E-Print Network [OSTI]

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 ...

Adames, Adrian A

2010-01-01T23:59:59.000Z

200

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

SciTech Connect (OSTI)

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.

VIlim, R.; Nuclear Engineering Division

2009-03-12T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers  

SciTech Connect (OSTI)

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.

Edward Levy; Harun Bilirgen; John DuPoint

2011-03-31T23:59:59.000Z

202

Recovery of Water from Boiler Flue Gas Using Condensing Heat Exchangers  

SciTech Connect (OSTI)

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.

Levy, Edward; Bilirgen, Harun; DuPont, John

2011-03-31T23:59:59.000Z

203

Welding of dissimilar alloys for high temperature heat exchangers for SOFC  

SciTech Connect (OSTI)

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.

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

2006-10-01T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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.

Chang H. Oh; Eung S. Kim

2008-09-01T23:59:59.000Z

205

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

SciTech Connect (OSTI)

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

Hughes, Patrick [ORNL; Im, Piljae [ORNL

2012-01-01T23:59:59.000Z

206

Hierarchical Modeling for Population-Based Heat Exchanger Design  

E-Print Network [OSTI]

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-

Geb, David

2013-01-01T23:59:59.000Z

207

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...

208

Value pricing of surface coatings for mitigating heat exchanger fouling  

E-Print Network [OSTI]

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...

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

2014-05-19T23:59:59.000Z

209

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

SciTech Connect (OSTI)

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.

Duane Spencer; Kevin McCoy

2010-02-02T23:59:59.000Z

210

ADVANCED HEAT EXCHANGERS USING TUNABLE NANOSCALE-MOLECULAR ASSEMBLY  

SciTech Connect (OSTI)

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.

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

2004-01-01T23:59:59.000Z

211

HEAT TRANSFER ANALYSIS FOR ION-EXCHANGE COLUMN SYSTEM  

SciTech Connect (OSTI)

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.

Lee, S.; King, W.

2011-05-23T23:59:59.000Z

212

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

E-Print Network [OSTI]

??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)

Padilla, Yadira

2012-01-01T23:59:59.000Z

213

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

SciTech Connect (OSTI)

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.

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

2004-03-26T23:59:59.000Z

214

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

E-Print Network [OSTI]

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...

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

2011-01-01T23:59:59.000Z

215

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

SciTech Connect (OSTI)

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.

Jacobs, H.R.

1985-01-01T23:59:59.000Z

216

The Influence of Availability Costs on Optimal Heat Exchanger Size  

E-Print Network [OSTI]

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...

Witte, L. C.

217

Design of chemical reactors of the heat exchanger type  

E-Print Network [OSTI]

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...

McBeth, Lloyd Theodore

1956-01-01T23:59:59.000Z

218

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

219

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

SciTech Connect (OSTI)

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.

Stickford, G.H.; Hindin, B.

1993-01-31T23:59:59.000Z

220

When to clean and how to clean biofilms in heat exchangers  

E-Print Network [OSTI]

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...

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

2014-07-02T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

E-Print Network [OSTI]

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...

Field, J. E.

2002-01-01T23:59:59.000Z

222

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

223

Experimental shellside flow visualization in a shell and tube heat exchanger  

E-Print Network [OSTI]

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...

Fischer, Matthew Winslow

1998-01-01T23:59:59.000Z

224

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

E-Print Network [OSTI]

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

Michalski, Ryszard S.

225

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

SciTech Connect (OSTI)

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.

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

2004-01-01T23:59:59.000Z

226

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

SciTech Connect (OSTI)

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)

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

227

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

SciTech Connect (OSTI)

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.

Gross, Andrew John

2014-01-01T23:59:59.000Z

228

Interface Exchange as an Indicator for Eddy Heat Transport  

SciTech Connect (OSTI)

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.

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

229

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

SciTech Connect (OSTI)

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

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

2012-09-01T23:59:59.000Z

230

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

E-Print Network [OSTI]

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

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

1980-01-01T23:59:59.000Z

231

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

E-Print Network [OSTI]

?? 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)

Cordova, Cordova

2013-01-01T23:59:59.000Z

232

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

SciTech Connect (OSTI)

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

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

2012-06-18T23:59:59.000Z

233

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]

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

Skogestad, Sigurd

234

Directly connected heat exchanger tube section and coolant-cooled structure  

DOE Patents [OSTI]

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.

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

235

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

SciTech Connect (OSTI)

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.

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

1998-06-01T23:59:59.000Z

236

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

DOE Patents [OSTI]

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.

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

1988-01-01T23:59:59.000Z

237

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

DOE Patents [OSTI]

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.

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

1981-11-02T23:59:59.000Z

238

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

DOE Patents [OSTI]

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.

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

2010-02-23T23:59:59.000Z

239

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

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

240

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

DOE Patents [OSTI]

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.

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

2011-11-22T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

DOE Patents [OSTI]

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.

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

1997-04-22T23:59:59.000Z

242

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

SciTech Connect (OSTI)

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)

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

243

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

SciTech Connect (OSTI)

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.

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

1995-02-01T23:59:59.000Z

244

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

SciTech Connect (OSTI)

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.

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

245

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

E-Print Network [OSTI]

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...

De Lange, Kevin Jon

1988-01-01T23:59:59.000Z

246

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

DOE Patents [OSTI]

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.

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

1994-01-01T23:59:59.000Z

247

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

DOE Patents [OSTI]

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.

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

1994-10-18T23:59:59.000Z

248

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

E-Print Network [OSTI]

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...

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

249

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

SciTech Connect (OSTI)

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.

Dinulescu, M.

1987-01-01T23:59:59.000Z

250

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

SciTech Connect (OSTI)

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.

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

2014-07-01T23:59:59.000Z

251

High Performance Trays and Heat Exchangers in Heat Pumped Distillation Columns  

E-Print Network [OSTI]

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...

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

1981-01-01T23:59:59.000Z

252

Light weight and economical exhaust heat exchanger for waste heat recovery  

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

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253

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

SciTech Connect (OSTI)

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.

Not Available

2010-12-01T23:59:59.000Z

254

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

SciTech Connect (OSTI)

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.

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

1982-08-01T23:59:59.000Z

255

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

SciTech Connect (OSTI)

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.

Arsalan Razani; Kwang J. Kim

2001-12-01T23:59:59.000Z

256

Tracking of Transgene Expression in Soybean using Robotics and GFP John James Finer  

E-Print Network [OSTI]

Tracking of Transgene Expression in Soybean using Robotics and GFP John James Finer Department system that is composed of a 2-dimensional robotics platform, a Leica MZFLIII fluorescence dissecting on the robotics platform. The platform contains docking centers for 16 Petri dishes, which are secured

Finer, John J.

257

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

SciTech Connect (OSTI)

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.

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

1981-01-01T23:59:59.000Z

258

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

SciTech Connect (OSTI)

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.

N. A. Anderson; P. Sabharwall

2014-01-01T23:59:59.000Z

259

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

SciTech Connect (OSTI)

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.

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

260

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

SciTech Connect (OSTI)

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.

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

2012-01-01T23:59:59.000Z

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261

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

SciTech Connect (OSTI)

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.

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

262

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

SciTech Connect (OSTI)

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.

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

1991-01-01T23:59:59.000Z

263

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

SciTech Connect (OSTI)

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.

Karaki, S.; Brothers, P.

1980-06-01T23:59:59.000Z

264

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

SciTech Connect (OSTI)

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.

Karaki, S.; Brothers, P.

1980-06-01T23:59:59.000Z

265

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

SciTech Connect (OSTI)

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)

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

266

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

SciTech Connect (OSTI)

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.

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

1980-04-01T23:59:59.000Z

267

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

SciTech Connect (OSTI)

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.

Jankura, B.J.

1996-01-01T23:59:59.000Z

268

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

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

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.

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

2014-12-01T23:59:59.000Z

269

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

SciTech Connect (OSTI)

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.

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

2014-10-01T23:59:59.000Z

270

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

E-Print Network [OSTI]

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 ...

McCarthy, Matthew

271

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

SciTech Connect (OSTI)

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.

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

2011-07-14T23:59:59.000Z

272

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

SciTech Connect (OSTI)

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.

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

273

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

SciTech Connect (OSTI)

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.

Bimal Kad

2011-12-31T23:59:59.000Z

274

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

E-Print Network [OSTI]

??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)

Padhmanabhan, Sankaranarayanan K.

2011-01-01T23:59:59.000Z

275

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

SciTech Connect (OSTI)

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.

J. K. Wright

2008-04-01T23:59:59.000Z

276

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

SciTech Connect (OSTI)

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.

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

2008-01-01T23:59:59.000Z

277

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...

278

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]

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

Paris-Sud XI, Universit de

279

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

SciTech Connect (OSTI)

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.

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

1980-12-01T23:59:59.000Z

280

Prediction and measurement of pitting damage functions for condensing heat exchangers  

SciTech Connect (OSTI)

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

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

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

E-Print Network [OSTI]

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...

American Society for Testing and Materials. Philadelphia

2010-01-01T23:59:59.000Z

282

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

SciTech Connect (OSTI)

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.

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

283

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

SciTech Connect (OSTI)

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

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

284

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

SciTech Connect (OSTI)

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

Vilim, R. B.; Nuclear Engineering Division

2009-03-12T23:59:59.000Z

285

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

E-Print Network [OSTI]

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.

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

2014-12-22T23:59:59.000Z

286

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

E-Print Network [OSTI]

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...

Saleh, Habeeb H.

2012-06-07T23:59:59.000Z

287

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

E-Print Network [OSTI]

) 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

Berning, Torsten

288

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

SciTech Connect (OSTI)

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.

Hirshman, J; Munier, R S.C.

1980-09-01T23:59:59.000Z

289

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

SciTech Connect (OSTI)

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.

Clauss, J.M.

1998-08-01T23:59:59.000Z

290

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

E-Print Network [OSTI]

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

Tokyo, University of

291

Dual source heat pump  

DOE Patents [OSTI]

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.

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

1982-01-01T23:59:59.000Z

292

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)

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.

Kudlac, G.A.

1998-06-01T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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.

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

1980-10-15T23:59:59.000Z

294

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

E-Print Network [OSTI]

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...

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

2002-01-01T23:59:59.000Z

295

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

SciTech Connect (OSTI)

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.

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

2014-04-01T23:59:59.000Z

296

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

SciTech Connect (OSTI)

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.

Gorzegno, W.P.

1993-06-15T23:59:59.000Z

297

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,...

298

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

SciTech Connect (OSTI)

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.

Powers, T.; Snyder, J.

1986-10-01T23:59:59.000Z

299

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

SciTech Connect (OSTI)

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.

Bimal K. Kad

2006-04-10T23:59:59.000Z

300

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

SciTech Connect (OSTI)

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.

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

2005-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Multiple source heat pump  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

302

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

E-Print Network [OSTI]

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

Wirtz, Richard A.

303

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

SciTech Connect (OSTI)

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.

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

304

Heat pump system  

DOE Patents [OSTI]

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.

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

1982-01-01T23:59:59.000Z

305

Integrated three-dimensional module heat exchanger for power electronics cooling  

DOE Patents [OSTI]

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.

Bennion, Kevin; Lustbader, Jason

2013-09-24T23:59:59.000Z

306

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)

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.

None

1982-09-01T23:59:59.000Z

307

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

DOE Patents [OSTI]

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.

Hall, M.N.

1996-04-30T23:59:59.000Z

308

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

DOE Patents [OSTI]

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.

Hall, Mark N. (Richland, WA)

1996-01-01T23:59:59.000Z

309

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

E-Print Network [OSTI]

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...

Fatima, Roma

2012-02-14T23:59:59.000Z

310

Evaluation Metrics for Intermediate Heat Exchangers for Next Generation Nuclear Reactors  

SciTech Connect (OSTI)

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.

Piyush Sabharwall; Eung Soo Kim; Nolan Anderson

2011-06-01T23:59:59.000Z

311

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

SciTech Connect (OSTI)

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.

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

1985-10-01T23:59:59.000Z

312

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

SciTech Connect (OSTI)

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

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

2005-06-03T23:59:59.000Z

313

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

SciTech Connect (OSTI)

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.

Belle R. Upadhyaya; J. Wesley Hines

2004-09-27T23:59:59.000Z

314

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]

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

Virginia Tech

315

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]

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

Kasagi, Nobuhide

316

Combined refrigeration system with a liquid pre-cooling heat exchanger  

DOE Patents [OSTI]

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.

Gaul, Christopher J.

2003-07-01T23:59:59.000Z

317

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)

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.

Cao, J.; Christensen, R.N.

2000-07-01T23:59:59.000Z

318

Industrial Waste Heat Recovery Using Heat Pipes  

E-Print Network [OSTI]

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...

Ruch, M. A.

1981-01-01T23:59:59.000Z

319

Development of a coal-fueled Internal Manifold Heat Exchanger (IMHEX reg sign ) molten carbonate fuel cell  

SciTech Connect (OSTI)

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.

Not Available

1991-09-01T23:59:59.000Z

320

Single Channel Testing for Characterization of the Direct Gas Cooled Reactor and the SAFE-100 Heat Exchanger  

SciTech Connect (OSTI)

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)

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Preliminary studies on the heat exchanger option for S-CO{sub 2} power conversion cycle coupled to water cooled SMR  

SciTech Connect (OSTI)

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)

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

322

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]

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

Victoria, University of

323

Heat pump with freeze-up prevention  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

324

Absorption heat pump system  

DOE Patents [OSTI]

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.

Grossman, G.

1982-06-16T23:59:59.000Z

325

Absorption heat pump system  

DOE Patents [OSTI]

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.

Grossman, Gershon (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

326

Optimal artificial neural network architecture selection for performance prediction of compact heat exchanger with the EBaLM-OTR technique  

SciTech Connect (OSTI)

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.

Dumidu Wijayasekara; Milos Manic; Piyush Sabharwall; Vivek Utgikar

2011-07-01T23:59:59.000Z

327

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 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...

Zhang, J.; Chen, Y.; Liang, Z.

2006-01-01T23:59:59.000Z

328

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]

. 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

Braun, Paul

329

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]

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...

Wood, H. A. T.

330

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange  

DOE Patents [OSTI]

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.

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

331

Process for oil shale retorting using gravity-driven solids flow and solid-solid heat exchange  

DOE Patents [OSTI]

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.

Lewis, A.E.; Braun, R.L.; Mallon, R.G.; Walton, O.R.

1983-09-21T23:59:59.000Z

332

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]

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...

Segura, D.; Acharya, S.

2012-01-01T23:59:59.000Z

333

Rotary magnetic heat pump  

DOE Patents [OSTI]

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.

Kirol, L.D.

1987-02-11T23:59:59.000Z

334

Mass and Heat Recovery  

E-Print Network [OSTI]

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...

Hindawai, S. M.

2010-01-01T23:59:59.000Z

335

Rotary magnetic heat pump  

DOE Patents [OSTI]

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.

Kirol, Lance D. (Shelly, ID)

1988-01-01T23:59:59.000Z

336

Heat pump having improved defrost system  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

337

Heat pump having improved defrost system  

DOE Patents [OSTI]

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.

Chen, F.C.; Mei, V.C.; Murphy, R.W.

1998-12-08T23:59:59.000Z

338

Heat storage with CREDA  

SciTech Connect (OSTI)

The principle of operation of ETS or Electric Thermal Storage is discussed in this book. As can be seen by the diagram presented, heating elements buried deep within the core are energized during off-peak periods or periods of lower cost energy. These elements charge the core to a per-determined level, then during the on-peak periods when the cost of electricity is higher or demand is higher, the heat is extracted from the core. The author discusses how this technology has progressed to the ETS equipment of today; this being the finer control of charging rates and extraction of heat from the core.

Beal, T. (Fostoria Industries, Fostoria, OH (US))

1987-01-01T23:59:59.000Z

339

Experimental development of the predictive relations for the eddy exchange coefficients for momentum and heat in the atmospheric boundary layer  

E-Print Network [OSTI]

, 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...

Jensen, Paul Alfred

2012-06-07T23:59:59.000Z

340

Heating system  

SciTech Connect (OSTI)

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.

Nishman, P.J.

1983-03-08T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Research on thermophoretic and inertial aspects of the ash particle deposition on heat exchanger surfaces in coal-fired equipment  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1986-12-01T23:59:59.000Z

342

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]

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

Urquiza, Eugenio

2009-01-01T23:59:59.000Z

343

Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1987-03-01T23:59:59.000Z

344

Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1989-03-01T23:59:59.000Z

345

Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1988-03-01T23:59:59.000Z

346

Development of a coal-fueled Internal Manifold Heat Exchanger (IMHEX{reg_sign}) molten carbonate fuel cell. Volumes 1--6, Final report  

SciTech Connect (OSTI)

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.

Not Available

1991-09-01T23:59:59.000Z

347

Heat pump system  

DOE Patents [OSTI]

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.

Swenson, Paul F. (Shaker Heights, OH); Moore, Paul B. (Fedhaven, FL)

1983-01-01T23:59:59.000Z

348

Heat pump system  

DOE Patents [OSTI]

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.

Swenson, Paul F.; Moore, Paul B.

1983-06-21T23:59:59.000Z

349

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]

Fig. 3 Journal of Heat Transfer Grid system for 2-row caseDomain and Grid System. Since the fin-and- tube heat

Zhou, Feng; Hansen, Nicholas E; Geb, David J; Catton, Ivan

2011-01-01T23:59:59.000Z

350

Direct contact heat exchanger performance  

SciTech Connect (OSTI)

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.

Wahl, E. F.

1981-03-12T23:59:59.000Z

351

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

352

High pressure ceramic heat exchanger  

DOE Patents [OSTI]

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.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1999-01-01T23:59:59.000Z

353

High pressure ceramic heat exchanger  

DOE Patents [OSTI]

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.

Harkins, Bruce D. (San Diego, CA); Ward, Michael E. (Poway, CA)

1998-01-01T23:59:59.000Z

354

High pressure ceramic heat exchanger  

DOE Patents [OSTI]

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.

Harkins, B.D.; Ward, M.E.

1998-09-22T23:59:59.000Z

355

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

356

Refrigerant charge management in a heat pump water heater  

DOE Patents [OSTI]

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.

Chen, Jie; Hampton, Justin W.

2014-06-24T23:59:59.000Z

357

Heat rejection system  

DOE Patents [OSTI]

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.

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

358

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...

359

Thulium-170 heat source  

DOE Patents [OSTI]

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.

Walter, Carl E. (Pleasanton, CA); Van Konynenburg, Richard (Livermore, CA); VanSant, James H. (Tracy, CA)

1992-01-01T23:59:59.000Z

360

Heat pump employing optimal refrigerant compressor for low pressure ratio applications  

DOE Patents [OSTI]

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.

Ecker, Amir L. (Dallas, TX)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED BUILDING ENERGY AND CFD SIMULATION  

E-Print Network [OSTI]

for the correct prediction of the convective heat. A finer grid resolution in CFD does not always lead to a more conservation equations of flow on these grid cells. As shown in Figure 1(a), CFD calculates convective heat1 NUMERICAL DETERMINATION AND TREATMENT OF CONVECTIVE HEAT TRANSFER COEFFICIENT IN THE COUPLED

Chen, Qingyan "Yan"

362

Stirling cycle engine and heat pump  

SciTech Connect (OSTI)

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.

Mitchell, M.P.

1986-11-18T23:59:59.000Z

363

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...

364

Heat Pipes: An Industrial Application  

E-Print Network [OSTI]

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...

Murray, F.

1984-01-01T23:59:59.000Z

365

Vitrification of ion exchange resins  

DOE Patents [OSTI]

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.

Cicero-Herman, Connie A. (Aiken, SC); Workman, Rhonda Jackson (North Augusta, SC)

2001-01-01T23:59:59.000Z

366

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)

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.

Rosner, D.E.

1987-03-01T23:59:59.000Z

367

Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect  

E-Print Network [OSTI]

)" #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

Boyer, Edmond

368

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...

369

Absorption heat pump system  

DOE Patents [OSTI]

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.

Grossman, Gershon (Oak Ridge, TN); Perez-Blanco, Horacio (Knoxville, TN)

1984-01-01T23:59:59.000Z

370

Method for controlling exhaust gas heat recovery systems in vehicles  

DOE Patents [OSTI]

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.

Spohn, Brian L.; Claypole, George M.; Starr, Richard D

2013-06-11T23:59:59.000Z

371

Thermal Analysis of LANL Ion Exchange Column  

SciTech Connect (OSTI)

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.

Laurinat, J.E.

1999-06-16T23:59:59.000Z

372

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

373

Frostless heat pump having thermal expansion valves  

DOE Patents [OSTI]

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.

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

2002-10-22T23:59:59.000Z

374

Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers  

E-Print Network [OSTI]

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...

Muraya, Norman K.

375

Agriculture on Exchange InternationalExchangeProgram  

E-Print Network [OSTI]

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

Viglas, Anastasios

376

Technical Note Solution of periodic heating problems by the  

E-Print Network [OSTI]

.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

Barber, James R.

377

Hear Exchange Assembly  

DOE Patents [OSTI]

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.

Lowenstein, Andrew (Princeton, NJ); Sibilia, Marc (Princeton, NJ); Miller, Jeffrey (Rocky Hill, NJ); Tonon, Thomas S. (Princeton, NJ)

2003-05-27T23:59:59.000Z

378

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-...

379

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

380

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

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Industrial Plate Exchangers Heat Recovery and Fouling  

E-Print Network [OSTI]

(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...

Cross, P. H.

1981-01-01T23:59:59.000Z

382

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

383

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

384

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

385

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

386

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

387

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

388

Open-loop heat-recovery dryer  

DOE Patents [OSTI]

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.

TeGrotenhuis, Ward Evan

2013-11-05T23:59:59.000Z

389

Experimental investigations about using the earth as a heat storage medium and as a heat source for heat pumps. Final report  

SciTech Connect (OSTI)

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.

Nievergeld, P.; Koppenol, A.; van der Brugh, J.

1981-03-01T23:59:59.000Z

390

The CO2 Reduction Potential of Combined Heat and Power in California's Commercial Buildings  

E-Print Network [OSTI]

heat exchangers, solar thermal collectors, absorptioncells; photovoltaics (PV) and solar thermal collectors; for application of solar thermal and recovered heat to end-

Stadler, Michael

2010-01-01T23:59:59.000Z

391

The CO2 Reduction Potential of Combined Heat and Power in California's Commercial Buildings  

E-Print Network [OSTI]

P.C. (2001), Introduction to Advancd Batteries for EmergingPV) and solar thermal collectors; conventional batteries,flow batteries, and heat storage; heat exchangers for

Stadler, Michael

2010-01-01T23:59:59.000Z

392

Model Based Diagnosis of an Air Source Heat Pump; Modellbaserad Diagnos av en Luftvrmepump.  

E-Print Network [OSTI]

?? 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)

Alfredsson, Sandra

2011-01-01T23:59:59.000Z

393

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)

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.

Not Available

1981-09-30T23:59:59.000Z

394

Heat pump system with selective space cooling  

DOE Patents [OSTI]

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.

Pendergrass, J.C.

1997-05-13T23:59:59.000Z

395

Heat pump system with selective space cooling  

DOE Patents [OSTI]

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.

Pendergrass, Joseph C. (Gainesville, GA)

1997-01-01T23:59:59.000Z

396

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]

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...

Dawoud, B.; Hofle, P.; Chmielewski, S.

2010-01-01T23:59:59.000Z

397

Energy-Exchange Project  

SciTech Connect (OSTI)

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)

Not Available

1982-04-01T23:59:59.000Z

398

The effects of airflow modulation and multi-stage defrost on the performance of an air source heat pump  

E-Print Network [OSTI]

. 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...

Payne, William Vance

1992-01-01T23:59:59.000Z

399

ME 339 Heat Transfer ABET EC2000 syllabus  

E-Print Network [OSTI]

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

Ben-Yakar, Adela

400

Absorption-heat-pump system  

DOE Patents [OSTI]

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.

Grossman, G.; Perez-Blanco, H.

1983-06-16T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Cascade heat recovery with coproduct gas production  

DOE Patents [OSTI]

A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange. 4 figs.

Brown, W.R.; Cassano, A.A.; Dunbobbin, B.R.; Rao, P.; Erickson, D.C.

1986-10-14T23:59:59.000Z

402

Cascade heat recovery with coproduct gas production  

DOE Patents [OSTI]

A process for the integration of a chemical absorption separation of oxygen and nitrogen from air with a combustion process is set forth wherein excess temperature availability from the combustion process is more effectively utilized to desorb oxygen product from the absorbent and then the sensible heat and absorption reaction heat is further utilized to produce a high temperature process stream. The oxygen may be utilized to enrich the combustion process wherein the high temperature heat for desorption is conducted in a heat exchange preferably performed with a pressure differential of less than 10 atmospheres which provides considerable flexibility in the heat exchange.

Brown, William R. (Zionsville, PA); Cassano, Anthony A. (Allentown, PA); Dunbobbin, Brian R. (Allentown, PA); Rao, Pradip (Allentown, PA); Erickson, Donald C. (Annapolis, MD)

1986-01-01T23:59:59.000Z

403

GEOTHERMAL HEAT PUMPS Jack DiEnna  

E-Print Network [OSTI]

by DOE, "a Geothermal heat pump is a highly efficient RENEWABLE energy technology". #12;ArgumentGEOTHERMAL HEAT PUMPS THE "PLAYBOOK" Jack DiEnna Executive Director The Geothermal National What do we call it... Geothermal, Ground Source, GeoExchange. The feds call it geothermal heat pumps

404

2008 DOE FCVT Merit Review: BSST Waste Heat Recovery Program  

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

in Th Developing a System Architecture to Manage Wide Variations in Th ermal Power ermal Power Catalytic Converter Primary Heat Exchanger Rear Exhaust with Muffler Pump DCDC...

405

Combined Heat and Power: Expanding CHP in Your State  

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

Turbines Electricity On-Site Consumption Sold to Utility Fuel Natural Gas Propane Biogas Landfill Gas Coal Steam Waste Products Others Generator Heat Exchanger Thermal Process...

406

Combined Heat & Power Technology Overview and Federal Sector...  

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

Fuel Cells Electricity On-Site Consumption Sold to Utility Fuel Natural Gas Propane Biogas Landfill Gas Coal Steam Waste Products Others Generator Heat Exchanger Thermal Steam...

407

Technical Information Exchange on Pyrolysis Oil: Potential for...  

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

Exchange on Pyrolysis Oil: Potential for a Renewab;e Heating Oil Substation Fuel in New England April 2012 Biomass Program News Blast June 2012 News Blast: Algae on the Mind...

408

atom heat processing: Topics by E-print Network  

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

accepted by industry, will fall into one of the three cycle categories. In a closed cycle heat pump, a working fluid exchanges heat... Priebe, S. J.; Chappell, R. N. 16 TOPICAL...

409

Drain-Water Heat Recovery | Department of Energy  

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

works well with all types of water heaters, especially with demand and solar water heaters. Drain-water heat exchangers can recover heat from the hot water used in showers,...

410

Heat-driven acoustic cooling engine having no moving parts  

DOE Patents [OSTI]

A heat-driven acoustic cooling engine having no moving parts receives heat from a heat source. The acoustic cooling engine comprises an elongated resonant pressure vessel having first and second ends. A compressible fluid having a substantial thermal expansion coefficient and capable of supporting an acoustic standing wave is contained in the resonant pressure vessel. The heat source supplies heat to the first end of the vessel. A first heat exchanger in the vessel is spaced-apart from the first end and receives heat from the first end. A first thermodynamic element is adjacent to the first heat exchanger and converts some of the heat transmitted by the first heat exchanger into acoustic power. A second thermodynamic element has a first end located spaced-apart from the first thermodynamic element and a second end farther away from the first thermodynamic element than is its first end. The first end of the second thermodynamic element heats while its second end cools as a consequence of the acoustic power. A second heat exchanger is adjacent to and between the first and second thermodynamic elements. A heat sink outside of the vessel is thermally coupled to and receives heat from the second heat exchanger. The resonant pressure vessel can include a housing less than one-fourth wavelength in length coupled to a reservoir. The housing can include a reduced diameter portion communicating with the reservoir.

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

1989-01-01T23:59:59.000Z

411

Enhanced two phase flow in heat transfer systems  

DOE Patents [OSTI]

A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

2013-12-03T23:59:59.000Z

412

Anion exchange polymer electrolytes  

DOE Patents [OSTI]

Solid anion exchange polymer electrolytes include chemical compounds comprising a polymer backbone with side chains that include guanidinium cations.

Kim, Yu Seung; Kim, Dae Sik

2013-09-10T23:59:59.000Z

413

Vehicle hydraulic system that provides heat for passenger compartment  

DOE Patents [OSTI]

A vehicle includes a vehicle housing which defines a passenger compartment. Attached to the vehicle housing is a hydraulic system, that includes a hydraulic fluid which flows through at least one passageway within the hydraulic system. Also attached to the vehicle housing is a passenger compartment heating system. The passenger compartment heating system includes a heat exchanger, wherein a portion of the heat exchanger is a segment of the at least one passageway of the hydraulic system.

Bartley, Bradley E. (Manito, IL); Blass, James R. (Bloomington, IL); Gibson, Dennis H. (Chillicothe, IL)

2001-01-01T23:59:59.000Z

414

Development of a compensation chamber for use in a multiple condenser loop heat pipe  

E-Print Network [OSTI]

The performance of many electronic devices is presently limited by heat dissipation rates. One potential solution lies in high-performance air-cooled heat exchangers like PHUMP, the multiple condenser loop heat pipe presented ...

Roche, Nicholas Albert

2013-01-01T23:59:59.000Z

415

Air heating system  

DOE Patents [OSTI]

A self-starting, fuel-fired, air heating system including a vapor generator, a turbine, and a condenser connected in a closed circuit such that the vapor output from the vapor generator is conducted to the turbine and then to the condenser where it is condensed for return to the vapor generator. The turbine drives an air blower which passes air over the condenser for cooling the condenser. Also, a condensate pump is driven by the turbine. The disclosure is particularly concerned with the provision of heat exchanger and circuitry for cooling the condensed fluid output from the pump prior to its return to the vapor generator.

Primeau, John J. (19800 Seminole Rd., Euclid, OH 44117)

1983-03-01T23:59:59.000Z

416

2005 ASHRAE. 109 Groundwater heat pump systems using standing column  

E-Print Network [OSTI]

©2005 ASHRAE. 109 ABSTRACT Groundwater heat pump systems using standing column wells as their ground heat exchanger can be used as a highly efficient source of heating and cooling in residential the well through the heat pump in an open-loop pipe circuit. Standing column wells have been in use

417

Super energy saver heat pump with dynamic hybrid phase change material  

DOE Patents [OSTI]

A heat pump has a refrigerant loop, a compressor in fluid communication with the refrigerant loop, at least one indoor heat exchanger in fluid communication with the refrigerant loop, and at least one outdoor heat exchanger in fluid communication with the refrigerant loop. The at least one outdoor heat exchanger has a phase change material in thermal communication with the refrigerant loop and in fluid communication with an outdoor environment. Other systems, devices, and methods are described.

Ally, Moonis Raza (Oak Ridge, TN) [Oak Ridge, TN; Tomlinson, John Jager (Knoxville, TN) [Knoxville, TN; Rice, Clifford Keith (Clinton, TN) [Clinton, TN

2010-07-20T23:59:59.000Z

418

Waste-heat recovery in batch processes using heat storage  

SciTech Connect (OSTI)

The waste-heat recovery in batch processes has been studied using the pinch-point method. The aim of the work has been to investigate theoretical and practical approaches to the design of heat-exchanger networks, including heat storage, for waste-heat recovery in batch processes. The study is limited to the incorporation of energy-storage systems based on fixed-temperature variable-mass stores. The background for preferring this to the alternatives (variable-temperature fixed-mass and constant-mass constant-temperature (latent-heat) stores) is given. It is shown that the maximum energy-saving targets as calculated by the pinch-point method (time average model, TAM) can be achieved by locating energy stores at either end of each process stream. This theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. A simple procedure for determining a number of heat-storage tanks sufficient to achieve the maximum energy-saving targets as calculated by the pinch-point method is described. This procedure relies on combinatorial considerations, and could therefore be labeled the combinatorial method for incorporation of heat storage in heat-exchanger networks. Qualitative arguments justifying the procedure are presented. For simple systems, waste-heat recovery systems with only three heat-storage temperatures (a hot storage, a cold storage, and a heat store at the pinch temperature) often can achieve the maximum energy-saving targets. Through case studies, six of which are presented, it is found that a theoretically large number of heat-storage tanks (twice the number of process streams) can be reduced to just a few tanks. The description of these six cases is intended to be sufficiently detailed to serve as benchmark cases for development of alternative methods.

Stoltze, S.; Mikkelsen, J.; Lorentzen, B.; Petersen, P.M.; Qvale, B. [Technical Univ. of Denmark, Lyngby (Denmark). Lab. for Energetics

1995-06-01T23:59:59.000Z

419

Chicago Climate Exchange, Inc. 2010 Chicago Climate Exchange 1 The Role of Exchanges and Standardization  

E-Print Network [OSTI]

Chicago Climate Exchange, Inc. 2010 Chicago Climate Exchange 1 The Role of Exchanges and Standardization in Reducing Emissions at Scale Michael J. Walsh, Ph.D. Executive Vice President Chicago Climate Exchange, Inc. #12;Chicago Climate Exchange, Inc. 2010 Chicago Climate Exchange Pacala-Socolow GHG

420

Wastewater heat recovery apparatus  

DOE Patents [OSTI]

A heat recovery system is described with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature. 6 figs.

Kronberg, J.W.

1992-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Wastewater heat recovery apparatus  

DOE Patents [OSTI]

A heat recovery system with a heat exchanger and a mixing valve. A drain trap includes a heat exchanger with an inner coiled tube, baffle plate, wastewater inlet, wastewater outlet, cold water inlet, and preheated water outlet. Wastewater enters the drain trap through the wastewater inlet, is slowed and spread by the baffle plate, and passes downward to the wastewater outlet. Cold water enters the inner tube through the cold water inlet and flows generally upward, taking on heat from the wastewater. This preheated water is fed to the mixing valve, which includes a flexible yoke to which are attached an adjustable steel rod, two stationary zinc rods, and a pivoting arm. The free end of the arm forms a pad which rests against a valve seat. The rods and pivoting arm expand or contract as the temperature of the incoming preheated water changes. The zinc rods expand more than the steel rod, flexing the yoke and rotating the pivoting arm. The pad moves towards the valve seat as the temperature of the preheated water rises, and away as the temperature falls, admitting a variable amount of hot water to maintain a nearly constant average process water temperature.

Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

1992-01-01T23:59:59.000Z

422

"Nanotechnology Enabled Advanced Industrial Heat Transfer Fluids"  

SciTech Connect (OSTI)

ABSTRACT Nanotechnology Enabled Advanced industrial Heat Transfer Fluids Improving the efficiency of Industrial Heat Exchangers offers a great opportunity to improve overall process efficiencies in diverse industries such as pharmaceutical, materials manufacturing and food processing. The higher efficiencies can come in part from improved heat transfer during both cooling and heating of the material being processed. Additionally, there is great interest in enhancing the performance and reducing the weight of heat exchangers used in automotives in order to increase fuel efficiency. The goal of the Phase I program was to develop nanoparticle containing heat transfer fluids (e.g., antifreeze, water, silicone and hydrocarbon-based oils) that are used in transportation and in the chemical industry for heating, cooling and recovering waste heat. Much work has been done to date at investigating the potential use of nanoparticle-enhanced thermal fluids to improve heat transfer in heat exchangers. In most cases the effect in a commercial heat transfer fluid has been marginal at best. In the Phase I work, we demonstrated that the thermal conductivity, and hence heat transfer, of a fluid containing nanoparticles can be dramatically increased when subjected to an external influence. The increase in thermal conductivity was significantly larger than what is predicted by commonly used thermal models for two-phase materials. Additionally, the surface of the nanoparticles was engineered so as to have a minimal influence on the viscosity of the fluid. As a result, a nanoparticle-laden fluid was successfully developed that can lead to enhanced heat transfer in both industrial and automotive heat exchangers

Dr. Ganesh Skandan; Dr. Amit Singhal; Mr. Kenneth Eberts; Mr. Damian Sobrevilla; Prof. Jerry Shan; Stephen Tse; Toby Rossmann

2008-06-12T23:59:59.000Z

423

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat. 11 figs.

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

1984-12-25T23:59:59.000Z

424

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. the second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

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

1984-01-01T23:59:59.000Z

425

Intrinsically irreversible heat engine  

DOE Patents [OSTI]

A class of heat engines based on an intrinsically irreversible heat transfer process is disclosed. In a typical embodiment the engine comprises a compressible fluid that is cyclically compressed and expanded while at the same time being driven in reciprocal motion by a positive displacement drive means. A second thermodynamic medium is maintained in imperfect thermal contact with the fluid and bears a broken thermodynamic symmetry with respect to the fluid. The second thermodynamic medium is a structure adapted to have a low fluid flow impedance with respect to the compressible fluid, and which is further adapted to be in only moderate thermal contact with the fluid. In operation, thermal energy is pumped along the second medium due to a phase lag between the cyclical heating and cooling of the fluid and the resulting heat conduction between the fluid and the medium. In a preferred embodiment the engine comprises an acoustical drive and a housing containing a gas which is driven at a resonant frequency so as to be maintained in a standing wave. Operation of the engine at acoustic frequencies improves the power density and coefficient of performance. The second thermodynamic medium can be coupled to suitable heat exchangers to utilize the engine as a simple refrigeration device having no mechanical moving parts. Alternatively, the engine is reversible in function so as to be utilizable as a prime mover by coupling it to suitable sources and sinks of heat.

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

1984-01-01T23:59:59.000Z

426

Electricity-producing heating apparatus utilizing a turbine generator in a semi-closed brayton cycle  

DOE Patents [OSTI]

The present invention provides apparatus and methods for producing both heat and electrical energy by burning fuels in a stove or boiler using a novel arrangement of a surface heat exchanger and microturbine-powered generator and novel surface heat exchanger. The equipment is particularly suited for use in rural and relatively undeveloped areas, especially in cold regions and highlands.

Labinov, Solomon D.; Christian, Jeffrey E.

2003-10-07T23:59:59.000Z

427

MODELING PARTICLE DEPOSITION ON HVAC HEAT JA Siegel1,3*  

E-Print Network [OSTI]

. Of Mechanical Engineering, University of California, Berkeley, CA, USA 2 Dept. Of Civil and Environmental degradation for heating, ventilating, and air conditioning (HVAC) systems. Particulate fouling of indoor fin: JASiegel@lbl.gov Proceedings: Indoor Air 2002 521 #12;HEAT EXCHANGER DESCRIPTION The HVAC heat exchangers

Siegel, Jeffrey

428

Indoor unit for electric heat pump  

DOE Patents [OSTI]

An indoor unit for an electric heat pump is provided in modular form including a refrigeration module, an air mover module, and a resistance heat package module, the refrigeration module including all of the indoor refrigerant circuit components including the compressor in a space adjacent the heat exchanger, the modules being adapted to be connected to air flow communication in several different ways as shown to accommodate placement of the unit in various orientations. 9 figs.

Draper, R.; Lackey, R.S.; Fagan, T.J. Jr.; Veyo, S.E.; Humphrey, J.R.

1984-05-22T23:59:59.000Z

429

Anion exchange membrane  

DOE Patents [OSTI]

An anion exchange membrane and fuel cell incorporating the anion exchange membrane are detailed in which proazaphosphatrane and azaphosphatrane cations are covalently bonded to a sulfonated fluoropolymer support along with anionic counterions. A positive charge is dispersed in the aforementioned cations which are buried in the support to reduce the cation-anion interactions and increase the mobility of hydroxide ions, for example, across the membrane. The anion exchange membrane has the ability to operate at high temperatures and in highly alkaline environments with high conductivity and low resistance.

Verkade, John G; Wadhwa, Kuldeep; Kong, Xueqian; Schmidt-Rohr, Klaus

2013-05-07T23:59:59.000Z

430

Research on thermophoretic and inertial aspects of the ash particle deposition on heat exchanger surfaces in coal-fired equipment. Quarterly technical report, September 1, 1986--November 30, 1986  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1986-12-01T23:59:59.000Z

431

Original article Influence of heating conditions in continuous-flow  

E-Print Network [OSTI]

, holding and cooling phases. When milk was heated in a continuous microwave heating system, at 90 C and cooling times. vitamin B1 / vitamin B2 / milk / microwave heating Rsum -- tude de l'effet des exchange systems on the vitamin B1 and B2 content of milk Isabel SIERRA, Concepcin VIDAL

Paris-Sud XI, Universit de

432

E-Print Network 3.0 - artificially heated waters Sample Search...  

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

Oklahoma State University (www.hvac.okstate.edu) Summary: exchanger, and water-to-water heat pumps have been developed and validated separately... from precipitation, and latent...

433

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,602 1,397...

434

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings* ... 1,870 1,276...

435

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Energy Consumption Survey: Energy End-Use Consumption Tables Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All...

436

Total Space Heating Water Heating Cook-  

Gasoline and Diesel Fuel Update (EIA)

Released: September, 2008 Total Space Heating Water Heating Cook- ing Other Total Space Heating Water Heating Cook- ing Other All Buildings ... 2,037...

437

Susanville District Heating District Heating Low Temperature...  

Open Energy Info (EERE)

Susanville District Heating District Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Susanville District Heating District Heating Low Temperature...

438

Application and Technology Requirements for Heat Pumps at the Process Industries  

E-Print Network [OSTI]

APPLICATION AND TECHNOLOGY REQUIREMENTS FOR HEAT PUMPS AT THE PROCESS INDUSTRIESl Stephen Priebe Engineering Specialist EG&G Idaho, Inc. Idaho Falls, ID There are basically three categories of equip ment used to manage heat energy flows... in an indus trial process. First, heat exchangers are used to move heat through the process down the temperature gradient. Second, heat pumps are used to move heat through the process up the temperature gra dient. Third, heat engines are used to convert...

Priebe, S.; Chappell, R.

439

Using Exergy Analysis Methodology to Assess the Heating Efficiency of an Electric Heat Pump  

E-Print Network [OSTI]

The authors, using exergy analysis methodology, propose that it should consider not only the COP (coefficient of Performance) value of the electric power heat pump set (EPHPS/or HP set), but also the exergy loss at the heating exchanger of the HP...

Ao, Y.; Duanmu, L.; Shen, S.

2006-01-01T23:59:59.000Z

440

Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment. Quarterly technical report No. 10, December 1, 1988--February 28, 1989  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1989-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "heat exchangers finer" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Research on thermophoretic and inertial aspects of ash particle deposition on heat exchanger surfaces in coal-fired equipment. Quarterly technical report No. 6, December 1, 1987--February 28, 1988  

SciTech Connect (OSTI)

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.

Rosner, D.E.

1988-03-01T23:59:59.000Z

442

Silicon ingot casting: Heat Exchanger Method (HEM)/multi-wire slicing: Fixed Abrasive Slicing Technique (FAST), Phase IV. Quarterly progress report No. 2, April 1, 1980-June 30, 1980  

SciTech Connect (OSTI)

Silicon ingot size cast by HEM has been extended to 34 cm x 34 cm x 10 cm. A 20 kg ingot has been solidified at 3 kg/hr with no crucible attachment or ingot cracking problems. Another ingot of 26 kg weight has also been solidified. The heat treatment used to develop a graded structure caused cracking on the inside surface of the first large crucibles. The thermal conditions were altered to minimize high gradients and the cracking was eliminated. A high degree of single crystallinity has been maintained as the size of the ingots has been increased. A graphite retainer made out of flat plates was used to produce an ingot with flat sides and rounded curves. It is now possible to electroplate diamonds only on the cutting edge of the wire. The advantages associated with diamonds on the cutting edge only are lower kerf, improved accuracy by improved seating in the support rollers, and less degradation of the rollers. This has resulted in less wander of wires and will reduce costs by using less diamonds and less degradation of rollers. The main failure mechanism of wires - diamond pullout - has been minimized by using filler diamonds to prevent erosion of the nickel matrix. It has been shown that an electroplated wirepack can be used to slice three 10 cm diameter silicon ingots without significant diamond pullout. IPEG analysis of value added costs of sheet formation using conservative and optimistic extension of HEM and FAST technologies yields $27.05/m/sup 2/ ($0.191/w) and $13.49/m/sup 2/ (0.095/w), respectively. Assuming cost goals of other tasks are met, the projected costs are $0.654/w, conservatively, and $0.539/w, optimistically, for photovoltaic modules.

Schmid, F.; Khattak, C.P.; Basaran, M.

1980-08-01T23:59:59.000Z

443

E-Print Network 3.0 - advanced heat pipes Sample Search Results  

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

Thermal Hinge System in IBM Thinkpad T series... 10 10 Figure 4 Schematic of a typical remote heat exchanger system 12 11 Figure 5 Heat pipe... in laptop computers rely on...

444

Analysis of vascular response to systemic heating using the pallid bat wing  

E-Print Network [OSTI]

The objective of this research is to analyze the relationship between environ-mental heat exchange and vascular response in the pallid bat wing during systemicheating and to develop a simplied model of heat transfer for theoretical analysis...

Mendez, Tanya

2009-05-15T23:59:59.000Z

445

Determination of heat transfer and friction characteristics of an adapted inclined louvered fin  

SciTech Connect (OSTI)

An experimental study of a fin-and-tube heat exchanger was performed. To this end a test rig was constructed to measure the heat transfer rate on the air and waterside of the heat exchanger. A wide range of Reynolds numbers on the airside was investigated. The resulting data was used to determine the convective heat transfer correlation (expressed using the Colburn factor) and the friction factor on the airside. The fin type used in the heat exchanger of this research is an adaptation of the standard inclined louvered type. A thorough error analysis was performed, to validate the results. (author)

T'Joen, C.; Steeman, H.-J.; Willockx, A.; De Paepe, M. [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Sint-Pietersnieuwstraat 41, 9000 Gent (Belgium)

2006-03-01T23:59:59.000Z

446

Ion exchange phenomena  

SciTech Connect (OSTI)

Ion exchange phenomena involve the population of readily exchangeable ions, the subset of adsorbed solutes that balance the intrinsic surface charge and can be readily replaced by major background electrolyte ions (Sposito, 2008). These phenomena have occupied a central place in soil chemistry research since Way (1850) first showed that potassium uptake by soils resulted in the release of an equal quantity of moles of charge of calcium and magnesium. Ion exchange phenomena are now routinely modeled in studies of soil formation (White et al., 2005), soil reclamation (Kopittke et al., 2006), soil fertilitization (Agbenin and Yakubu, 2006), colloidal dispersion/flocculation (Charlet and Tournassat, 2005), the mechanics of argillaceous media (Gajo and Loret, 2007), aquitard pore water chemistry (Tournassat et al., 2008), and groundwater (Timms and Hendry, 2007; McNab et al., 2009) and contaminant hydrology (Chatterjee et al., 2008; van Oploo et al., 2008; Serrano et al., 2009).

Bourg, I.C.; Sposito, G.

2011-05-01T23:59:59.000Z

447

Radiant Heating | 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 »ExchangeDepartment ofManagement PropertyQuiz:Heating Radiant

448

Method and apparatus for fuel gas moisturization and heating  

DOE Patents [OSTI]

Fuel gas is saturated with water heated with a heat recovery steam generator heat source. The heat source is preferably a water heating section downstream of the lower pressure evaporator to provide better temperature matching between the hot and cold heat exchange streams in that portion of the heat recovery steam generator. The increased gas mass flow due to the addition of moisture results in increased power output from the gas and steam turbines. Fuel gas saturation is followed by superheating the fuel, preferably with bottom cycle heat sources, resulting in a larger thermal efficiency gain compared to current fuel heating methods. There is a gain in power output compared to no fuel heating, even when heating the fuel to above the LP steam temperature.

Ranasinghe, Jatila (Niskayuna, NY); Smith, Raub Warfield (Ballston Lake, NY)

2002-01-01T23:59:59.000Z

449

Chemical exchange program analysis.  

SciTech Connect (OSTI)

As part of its EMS, Sandia performs an annual environmental aspects/impacts analysis. The purpose of this analysis is to identify the environmental aspects associated with Sandia's activities, products, and services and the potential environmental impacts associated with those aspects. Division and environmental programs established objectives and targets based on the environmental aspects associated with their operations. In 2007 the most significant aspect identified was Hazardous Materials (Use and Storage). The objective for Hazardous Materials (Use and Storage) was to improve chemical handling, storage, and on-site movement of hazardous materials. One of the targets supporting this objective was to develop an effective chemical exchange program, making a business case for it in FY07, and fully implementing a comprehensive chemical exchange program in FY08. A Chemical Exchange Program (CEP) team was formed to implement this target. The team consists of representatives from the Chemical Information System (CIS), Pollution Prevention (P2), the HWMF, Procurement and the Environmental Management System (EMS). The CEP Team performed benchmarking and conducted a life-cycle analysis of the current management of chemicals at SNL/NM and compared it to Chemical Exchange alternatives. Those alternatives are as follows: (1) Revive the 'Virtual' Chemical Exchange Program; (2) Re-implement a 'Physical' Chemical Exchange Program using a Chemical Information System; and (3) Transition to a Chemical Management Services System. The analysis and benchmarking study shows that the present management of chemicals at SNL/NM is significantly disjointed and a life-cycle or 'Cradle-to-Grave' approach to chemical management is needed. This approach must consider the purchasing and maintenance costs as well as the cost of ultimate disposal of the chemicals and materials. A chemical exchange is needed as a mechanism to re-apply chemicals on site. This will not only reduce the quantity of unneeded chemicals and the amount spent on new purchases, but will also avoid disposal costs. If SNL/NM were to realize a 5 percent reduction in chemical inventory and a 10 percent reduction in disposal of unused chemicals the total savings would be $189, 200 per year.

Waffelaert, Pascale

2007-09-01T23:59:59.000Z

450

Modeling bronchial circulation with application to soluble gas exchange: description and sensitivity analysis  

E-Print Network [OSTI]

Modeling bronchial circulation with application to soluble gas exchange: description into an existing model that describes the simul- taneous exchange of heat, water, and a soluble gas in the airways and represents an avenue to understanding the ex- change process. The soluble gas used in the model simulations

George, Steven C.

451

Earth-Coupled Water-Source Heat Pump Research, Design and Applications in Louisiana  

E-Print Network [OSTI]

An earth-coupled water-source heat pump uses the earth as the thermal source and sink for economical, energy efficient, space heating and cooling. Water exiting the heat pump passes through an earth heat exchanger, which is a closed loop of plastic...

Braud, H. J.; Klimkowski, H.; Baker, F. E.

1985-01-01T23:59:59.000Z

452

A batch reactor heat recovery challenge problem Johannes Jschke, Sigurd Skogestad  

E-Print Network [OSTI]

A batch reactor heat recovery challenge problem Johannes Jäschke, Sigurd Skogestad Department a challenge problem fo