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1

Air flow in a high aspect ratio heat sink  

E-Print Network (OSTI)

The increasing heat output of modern electronics requires concomitant advances in heat sinking technology: reductions in thermal resistance and required pumping power are necessary. This research covers the development of ...

Allison, Jonathan Michael

2010-01-01T23:59:59.000Z

2

Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions  

SciTech Connect

A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

2012-08-29T23:59:59.000Z

3

Heat flow of Oregon  

DOE Green Energy (OSTI)

An extensive new heat flow and geothermal gradient data set for the State of Oregon is presented on a contour map of heat flow at a scale of 1:1,000,000 and is summarized in several figures and tables. The 1:1,000,000 scale heat flow map is contoured at 20 mW/m/sup 2/ (0.5 HFU) intervals. Also presented are maps of heat flow and temperature at a depth of 1 km averaged for 1/sup 0/ x 1/sup 0/ intervals. Histograms and averages of geothermal gradient and heat flow for the State of Oregon and for the various physiographic provinces within Oregon are also included. The unweighted mean flow for Oregon is 81.3 +- 2.7 mW/m/sup 2/ (1.94 +- 0.06 HFU). The average unweighted geothermal gradient is 65.3 +- 2.5/sup 0/C/km. The average heat flow value weighted on the basis of geographic area is 68 +- 5 mW/m/sup 2/ (1.63 +- 0.12 HFU) and the average weighted geothermal gradient is 55.0 +- 5/sup 0/C/km.

Blackwell, D.D.; Hull, D.A.; Bowen, R.G.; Steele, J.L.

1978-01-01T23:59:59.000Z

4

Film boiling of saturated liquid flowing upward through a heated tube : high vapor quality range  

E-Print Network (OSTI)

Film boiling of saturated liquid flowing upward through a uniformly heated tube has been studied for the case in which pure saturated liquid enters the tube and nearly saturated vapor is discharged. Since a previous study ...

Laverty, W. F.

1964-01-01T23:59:59.000Z

5

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas-  

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Details Activities (5) Areas (5) Regions (0) Abstract: Surface heat flow measurements over active geothermal systems indicate strongly positive thermal anomalies. Whereas in "normal" geothermal settings, the surface heat flow is usually below 100-120 mW m- 2, in active geothermal areas heat flow values as high as several watts per meter squared can be found. Systematic interpretation of heat flow patterns sheds light on heat transfer mechanisms at depth on different lateral, depth and time scales. Borehole temperature profiles in active geothermal

6

Convective heat flow probe  

DOE Patents (OSTI)

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

7

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In  

Open Energy Info (EERE)

Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In The Precambrian And Younger Silicic Rocks Of The Zuni And Florida Mountains, New Mexico (Usa) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Potassium, Uranium, Thorium Radiogenic Heat Contribution To Heat Flow In The Precambrian And Younger Silicic Rocks Of The Zuni And Florida Mountains, New Mexico (Usa) Details Activities (4) Areas (2) Regions (0) Abstract: High heat flow in the Zuni Mountains, New Mexico, U.S.A., has been explained by the possible presence of a buried felsic pluton. Alternately, high K, U, Th abundances have been proposed to account for part of the high heat flow. The mean radiogenic heat contribution for 60 samples of Precambrian core rocks is 7.23 ÎĽcal/gm-yr, which is slightly

8

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

9

Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...  

Open Energy Info (EERE)

Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow,...

10

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part II: Flow Structure and Heat Budgets  

Science Conference Proceedings (OSTI)

This paper analyzes the three-dimensional flow structure and the heat budget in a typical medium-sized and steep Alpine valley—the Riviera Valley in southern Switzerland. Aircraft measurements from the Mesoscale Alpine Programme (MAP)-Riviera ...

Andreas P. Weigel; Fotini K. Chow; Mathias W. Rotach; Robert L. Street; Ming Xue

2006-01-01T23:59:59.000Z

11

A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements  

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Details Activities (0) Areas (0) Regions (0) Abstract: A comprehensive database of temperature, heat flow, thermal conductivity and geochemistry is the basis of geothermal modelling. The latest revision (1987) of the UK Geothermal Catalogue (UKGC) contains over 2600 temperatures at over 1150 sites and over 200 observations of heat flow. About 93% of the temperature data are from depths less than 2000 m and about 50% are Bottom Hole Temperatures (BHT). Heat-flow density

12

Flow modification in McGill Heat Pipes.  

E-Print Network (OSTI)

??A heat pipe is a heat transfer device of very high thermal conductance that features two-phase flow. Research at McGill University has led to the… (more)

Lee, JuHee, 1973-

2005-01-01T23:59:59.000Z

13

Analysis of the transient compressible vapor flow in heat pipe  

SciTech Connect

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-07-01T23:59:59.000Z

14

Heat-flow reconnaissance of the Gulf Coastal Plain  

DOE Green Energy (OSTI)

Most of the 46 new values of heat flow determined for the Gulf Coastal Plain are in the low to normal range, but heat-flow values averaging 1.8 heat-flow unit (HFU) were obtained in Claiborne, Ouachita, and Union parishes, Louisiana. Moreover, a zone of relatively high heat-flow values and steep thermal gradients (35 to 46/sup 0/C/km) extends from northern Louisiana into southwestern Mississippi. Also near Pensacola, Florida, temperatures of 50/sup 0/C at 1-km depth have been extrapolated from thermal gradients. Future development of low-grade geothermal resources may be warranted in these areas.

Smith, D.L.; Shannon, S.S. Jr.

1982-04-01T23:59:59.000Z

15

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 in such an exchanger are derived and solved leading to an optimization problem. In this problem, the optimal subdivision of heat transfer surface to minimize required overall heat transfer surface, under certain restricted conditions, is sought. It is shown that the off-center nozzle location can be selected judiciously so as to maintain (or even improve heat transfer) while reducing the gross shellside pressure loss. Thus, the pumping costs are minimized without sacrificing heat transfer.

Singh, K. P.

1979-01-01T23:59:59.000Z

16

Heat Pump for High School Heat Recovery  

E-Print Network (OSTI)

The heat pump system used for recycling and reusing waste heat in s high school bathroom was minutely analyzed in its coefficient of performance, onetime utilization ratio of energy, economic property and so on. The results showed that this system has good economic property, can conserve energy and protects the environment. Therefore, there is a large potential for its development. In addition, three projects using this system are presented and contrasted, which indicate that a joint system that uses both the heat pump and heat exchanger to recycle waste heat is a preferable option.

Huang, K.; Wang, H.; Zhou, X.

2006-01-01T23:59:59.000Z

17

Heat-flow studies in Wyoming, 1979 to 1981  

DOE Green Energy (OSTI)

Thirty heat flow values completed during May 1981 for Wyoming are tabulated and updated maps of heat flow in Wyoming and adjacent areas are presented.

Decker, E.R.; Heasler, H.P.; Buelow, K.L.

1981-12-01T23:59:59.000Z

18

Heat flow in the postquasistatic approximation  

Science Conference Proceedings (OSTI)

We apply the postquasistatic approximation to study the evolution of spherically symmetric fluid distributions undergoing dissipation in the form of radial heat flow. For a model that corresponds to an incompressible fluid departing from the static equilibrium, it is not possible to go far from the initial state after the emission of a small amount of energy. Initially collapsing distributions of matter are not permitted. Emission of energy can be considered as a mechanism to avoid the collapse. If the distribution collapses initially and emits one hundredth of the initial mass only the outermost layers evolve. For a model that corresponds to a highly compressed Fermi gas, only the outermost shell can evolve with a shorter hydrodynamic time scale.

Rodriguez-Mueller, B. [Computational Science Research Center, College of Sciences, San Diego State University, San Diego, California (United States); Peralta, C. [Deutscher Wetterdienst, Frankfurter Strasse 135, 63067 Offenbach (Germany); School of Physics, University of Melbourne, Parkville, VIC 3010 (Australia); Barreto, W. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Rosales, L. [Laboratorio de Fisica Computacional, Universidad Experimental Politecnica, 'Antonio Jose de Sucre', Puerto Ordaz (Venezuela, Bolivarian Republic of)

2010-08-15T23:59:59.000Z

19

Method for identifying anomalous terrestrial heat flows  

DOE Patents (OSTI)

A method for locating and mapping the magnitude and extent of terrestrial heat-flow anomalies from 5 to 50 times average with a tenfold improved sensitivity over orthodox applications of aerial temperature-sensing surveys as used for geothermal reconnaissance. The method remotely senses surface temperature anomalies such as occur from geothermal resources or oxidizing ore bodies by: measuring the spectral, spatial, statistical, thermal, and temporal features characterizing infrared radiation emitted by natural terrestrial surfaces; deriving from these measurements the true surface temperature with uncertainties as small as 0.05 to 0.5 K; removing effects related to natural temperature variations of topographic, hydrologic, or meteoric origin, the surface composition, detector noise, and atmospheric conditions; factoring out the ambient normal-surface temperature for non-thermally enhanced areas surveyed under otherwise identical environmental conditions; distinguishing significant residual temperature enhancements characteristic of anomalous heat flows and mapping the extent and magnitude of anomalous heat flows where they occur.

Del Grande, Nancy Kerr (San Leandro, CA)

1977-01-25T23:59:59.000Z

20

Heat Transfer Enhancement in Separated and Vortex Flows  

SciTech Connect

This document summarizes the research performance done at the Heat Transfer Laboratory of the University of Minnesota on heat transfer and energy separation in separated and vortex flow supported by DOE in the period September 1, 1998--August 31, 2003. Unsteady and complicated flow structures in separated or vortex flows are the main reason for a poor understanding of heat transfer under such conditions. The research from the University of Minnesota focused on the following important aspects of understanding such flows: (1) Heat/mass transfer from a circular cylinder; (2) study of energy separation and heat transfer in free jet flows and shear layers; and (3) study of energy separation on the surface and in the wake of a cylinder in crossflow. The current study used three different experimental setups to accomplish these goals. A wind tunnel and a liquid tunnel using water and mixtures of ethylene glycol and water, is used for the study of prandtl number effect with uniform heat flux from the circular cylinder. A high velocity air jet is used to study energy separation in free jets. A high speed wind tunnel, same as used for the first part, is utilized for energy separation effects on the surface and in the wake of the circular cylinder. The final outcome of this study is a substantial advancement in this research area.

Richard J. Goldstein

2004-05-27T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Preferential flow paths and heat pipes: Results from laboratory experiments on heat-driven flow in natural and artificial rock fractures  

SciTech Connect

Water flow in fractures under the conditions of partial saturation and thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. Water flowing in fast pathways may ultimately contact waste packages at Yucca Mountain and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize liquid flow in glass fracture models, a transparent epoxy fracture replica, and a rock/replica fracture assembly. Spatially resolved thermal monitoring was performed in seven of these experiments to evaluate heat-pipe formation. Depending on the fracture apertures and flow conditions, various flow regimes were observed including continuous rivulet flow for high flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for low flow rates and wide apertures. These flow regimes were present in both fracture models and in the replica of a natural fracture. Heat-pipe conditions indicated by low thermal gradients were observed in five experiments. Conditions conducive to heat-pipe formation include an evaporation zone, condensation zone, adequate space for vapor and liquid to travel, and appropriate fluid driving forces. In one of the two experiments where heat pipe conditions were not observed, adequate space for liquid-vapor counterflow was not provided. Heat pipe conditions were not established in the other, because liquid flow was inadequate to compensate for imbibition and the quantity of heat contained within the rock.

Kneafsey, T.J.; Pruess, K. [Lawrence Berkeley National Lab., CA (United States). Earth Sciences Div.

1997-06-01T23:59:59.000Z

22

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents (OSTI)

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier`s Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

1990-12-31T23:59:59.000Z

23

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents (OSTI)

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

1990-01-01T23:59:59.000Z

24

Triaxial thermopile array geo-heat-flow sensor  

DOE Patents (OSTI)

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.

Carrigan, Charles R. (Tracy, CA); Hardee, Harry C. (Albuquerque, NM); Reynolds, Gerald D. (Tijeras, NM); Steinfort, Terry D. (Tijeras, NM)

1992-01-01T23:59:59.000Z

25

Triaxial thermopile array geo-heat-flow sensor  

DOE Green Energy (OSTI)

A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

1990-01-01T23:59:59.000Z

26

Flow fields and heat transfer of liquid falling film on horizontal cylinders.  

E-Print Network (OSTI)

??A liquid film flowing over horizontal cylinders is of great importance as a high rate of heat transfer exists between the falling liquid film and… (more)

Jafar, Farial A

2011-01-01T23:59:59.000Z

27

Heat Flow-Thermodynamic Depth Complexity in Networks  

Science Conference Proceedings (OSTI)

In this paper we establish a formal link between network complexity in terms of Birkhoff-von Newmann decompositions and heat flow complexity (in terms of quantifying the heat flowing through the network at a given inverse temperature). Furthermore, we ...

Francisco Escolano; Miguel A. Lozano; Edwin R. Hancock

2010-08-01T23:59:59.000Z

28

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

Science Conference Proceedings (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 800°C. 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

29

Hamiltonian Thermostats Fail to Promote Heat Flow  

E-Print Network (OSTI)

Hamiltonian mechanics can be used to constrain temperature simultaneously with energy. We illustrate the interesting situations that develop when two different temperatures are imposed within a composite Hamiltonian system. The model systems we treat are "phi-4" chains, with quartic tethers and quadratic nearest-neighbor Hooke's-law interactions. This model is known to satisfy Fourier's law. Our prototypical problem sandwiches a Newtonian subsystem between hot and cold Hamiltonian reservoir regions. We have characterized four different Hamiltonian reservoir types. There is no tendency for any of these two-temperature Hamiltonian simulations to transfer heat from the hot to the cold degrees of freedom. Evidently steady heat flow simulations require energy sources and sinks, and are therefore incompatible with Hamiltonian mechanics.

Wm. G. Hoover; Carol G. Hoover

2013-03-25T23:59:59.000Z

30

High Temperature Heat Exchanger Project  

Science Conference Proceedings (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

31

Thaw flow control for liquid heat transport systems  

DOE Patents (OSTI)

In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

Kirpich, Aaron S. (Broomall, PA)

1989-01-01T23:59:59.000Z

32

Comparison of heat transfer in solar collectors with heat pipe versus flow through absorbers  

DOE Green Energy (OSTI)

Analysis of heat transfer in solar collectors with heat pipe absorbers is compared to that for collectors with flow through absorbers. Both pumped and thermosiphon systems that produce hot water or other heated fluids are discussed. In these applications the heat pipe absorber suffers a heat transfer penalty compared with the flow through absorber, but in many cases the penalty can be minimized by proper design at the heat pipe condenser and system manifold. When the solar collector is used to drive an absorption chiller, the heat pipe absorber has better heat transfer characteristics than the flow through absorber.

Hull, J.R.

1985-01-01T23:59:59.000Z

33

Development of Technologies on Innovative-Simplified Nuclear Power Plant Using High-Efficiency Steam Injectors (12) Evaluations of Spatial Distributions of Flow and Heat Transfer in Steam Injector  

SciTech Connect

Next-generation nuclear reactor systems have been under development aiming at simplified system and improvement of safety and credibility. One of the innovative technologies is the supersonic steam injector, which has been investigated as one of the most important component of the next-generation nuclear reactor. The steam injector has functions of a passive pump without large motor or turbo-machinery and a high efficiency heat exchanger. The performances of the supersonic steam injector as a pump and a heat exchanger are dependent on direct contact condensation phenomena between a supersonic steam and a sub-cooled water jet. In previous studies of the steam injector, there are studies about the operating characteristics of steam injector and about the direct contact condensation between static water pool and steam in atmosphere. However, there is a little study about the turbulent heat transfer and flow behavior under the great shear stress. In order to examine the heat transfer and flow behavior in supersonic steam injector, it is necessary to measure the spatial temperature distribution and velocity in detail. The present study, visible transparent supersonic steam injector is used to obtain the axial pressure distributions in the supersonic steam injector, as well as high speed visual observation of water jet and steam interface. The experiments are conducted with and without non-condensable gas. The experimental results of the interfacial flow behavior between steam and water jet are obtained. It is experimentally clarified that an entrainment exists on the water jet surface. It is also clarified that discharge pressure is depended on the steam supply pressure, the inlet water flow rate, the throat diameter and non-condensable flow rate. Finally a heat flux is estimated about 19 MW/m{sup 2} without non-condensable gas condition in steam. (authors)

Yutaka Abe; Yujiro Kawamoto [University of Tsukuba, Tsukuba, Ibaraki (Japan); Chikako Iwaki [Toshiba Corporation (Japan); Tadashi Narabayashi [Hokkaido University, Kita-ku, Sapporo (Japan); Michitsugu Mori; Shuichi Ohmori [Tokyo Electric Power Company (Japan)

2006-07-01T23:59:59.000Z

34

Development of a fuel-rod simulator and small-diameter thermocouples for high-temperature, high-heat-flux tests in the Gas-Cooled Fast Reactor Core Flow Test Loop  

SciTech Connect

The Core Flow Test Loop was constructed to perform many of the safety, core design, and mechanical interaction tests in support of the Gas-Cooled Fast Reactor (GCFR) using electrically heated fuel rod simulators (FRSs). Operation includes many off-normal or postulated accident sequences including transient, high-power, and high-temperature operation. The FRS was developed to survive: (1) hundreds of hours of operation at 200 W/cm/sup 2/, 1000/sup 0/C cladding temperature, and (2) 40 h at 40 W/cm/sup 2/, 1200/sup 0/C cladding temperature. Six 0.5-mm type K sheathed thermocouples were placed inside the FRS cladding to measure steady-state and transient temperatures through clad melting at 1370/sup 0/C.

McCulloch, R.W.; MacPherson, R.E.

1983-03-01T23:59:59.000Z

35

A Cross-Flow Ceramic Heat Recuperator for Industrial Heat Recovery  

E-Print Network (OSTI)

With increasing fuel costs, the efficient use of fuel is very important to the U.S. process heat industries. Increase in fuel usage efficiency can be obtained by transferring the waste exhaust heat to the cold combustion air. The metallic recuperators currently available suffer from problems of creep, corrosion and oxidation, particularly at high temperatures. The Department of Energy and GTE Products corporation have pursued a jointly funded venture, Contract No. EX-76-C-Q1-2162, to establish performance criteria and demonstrate a cross-flow ceramic heat recuperator for high temperature industrial heat recovery applications. The immediate goals of the ceramic recuperator project were to demonstrate a heat exchanger capable of handling high temperatures (1600-2400oF), that is compact with a high surface area and with costs comparable to the lower temperature metal heat exchangers. This paper describes the basic GTE Products Corporation design and details the design basis, the predicted recuperator performance, the ceramic and housing materials, the recuperator design procedure and the fabrication and assembly. The data provided includes NTU-Effectiveness and low friction and heat transfer ("f" and "J") plots.

Gonzalez, J. M.; Cleveland, J. J.; Kohnken, K. H.; Rebello, W. J.

1980-01-01T23:59:59.000Z

36

Heat flow in relation to hydrothermal activity in the southern Black Rock Desert, Nevada  

DOE Green Energy (OSTI)

As part of an investigation of the Gerlach NE KGRA (Known Geothermal Resource Area) a number of heat-flow measurements were made in playa sediments of the southern Black Rock Desert, northwestern Nevada. These data together with additional previously unpublished heat-flow values reveal a complex pattern of heat flow with values ranging between 1.0 to 5.0 HFU (40 to 100 mWm/sup -2/) outside of the hot springs area. The mean heat flow for the 13 reported sites in the southern Black Rock Desert is 1.8 +- 0.15 HFU (75 +- 6 mWm/sup -2/). The complexity of the pattern of heat flow is believed to arise from hydrothermal circulation supporting the numerous hot springs throughout the region. The fact that the lowest observed heat flow occurs in the deepest part of the basin strongly suggests that fluid movement within the basin represents part of the recharge for the hydrothermal system. A thermal balance for the system incorporating both anomalous conductive heat loss and convective heat loss from the spring systems indicate a total energy loss of about 8.0 Mcal/sec or 34 megawatts over an estimated 1000 km/sup 2/ region. Consideration of this additional heat loss yields a mean regional heat flow of 2.5 + HFU (100 + mWm/sup -2/) and warrants inclusion of this region in the Battle Mountain heat-flow high (Lachenbruch and Sass, 1977, 1978).

Sass, J.H.; Zoback, M.L.; Galanis, S.P. Jr.

1979-01-01T23:59:59.000Z

37

Influence of Ohmic Heating on Advection-Dominated Accretion Flows  

E-Print Network (OSTI)

Advection-dominated, high-temperature, quasi-spherical accretion flow onto a compact object of mass M, recently considered by a number of authors, assume that the dissipation of turbulent energy of the flow heats the ions and that a constant fraction f of the dissipated energy is advected inward. It is suggested that the efficiency of conversion of accretion energy to radiation can be very much smaller than unity. However, it is likely that the flows have an equipartition magnetic field with the result that dissipation of magnetic energy at a rate comparable to that for the turbulence must occur by Ohmic heating. We argue that this heating occurs as a result of plasma instabilities and that the relevant instabilities are current driven in response to the strong electric fields parallel to the magnetic field. We argue further that these instabilities heat predominantly the electrons. We analyze a model for the radial dependence of the ion and electron temperatures of a general, possibly quasi-spherical accreti...

Bisnovatyi-Kogan, G S

1997-01-01T23:59:59.000Z

38

Heat transfer and pressure drop in tape generated swirl flow  

E-Print Network (OSTI)

The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...

Lopina, Robert F.

1967-01-01T23:59:59.000Z

39

In-situ determination of heat flow in unconsolidated sediments  

DOE Green Energy (OSTI)

Subsurface thermal measurements are the most effective, least ambiguous tools for identifying and delineating possible geothermal resources. A technique was developed which provides reliable real-time determinations of temperature, thermal conductivity, and hence, of heat flow during the drilling operation in unconsolidated sediments. A combined temperature, gradient, and thermal conductivity experiment can be carried out, by driving a thin probe through the bit about 1.5 meters into the formation in the time that would otherwise be required for a coring trip. Two or three such experiments over the depth range of, say, 50 to 150 meters provide a high-quality heat-flow determination at costs comparable to those associated with a standard cased gradient hole to comparable depths. The hole can be backfilled and abandoned upon cessation of drilling, thereby eliminating the need for casing, grouting, or repeated site visits.

Sass, J.H.; Kennelly, J.P. Jr.; Wendt, W.E.; Moses, T.H. Jr.; Ziagos, J.P.

1979-01-01T23:59:59.000Z

40

The International Heat Flow Commission | Open Energy Information  

Open Energy Info (EERE)

The International Heat Flow Commission The International Heat Flow Commission Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: The International Heat Flow Commission Details Activities (1) Areas (1) Regions (0) Abstract: Unavailable Author(s): A. E. Beck, V. Cermak Published: Geothermics, 1989 Document Number: Unavailable DOI: Unavailable Source: View Original Journal Article Data Acquisition-Manipulation (Beck & Cermak, 1989) Unspecified Retrieved from "http://en.openei.org/w/index.php?title=The_International_Heat_Flow_Commission&oldid=387748" Category: Reference Materials What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 1863774514

Note: This page contains sample records for the topic "high heat flow" 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

Heat flow determinations and implied thermal regime of the Coso...  

Open Energy Info (EERE)

determinations and implied thermal regime of the Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Heat flow...

42

Heat flow and microearthquake studies, Coso Geothermal Area,...  

Open Energy Info (EERE)

and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the...

43

Handbook of thermodynamics, heat transfer and fluid flow  

E-Print Network (OSTI)

9 Nov 2010 ... Handbook of thermodynamics, heat transfer and fluid flow | JUNE 1992 | 3 Volume | U.S. Department of Energy FSC-6910 Washington, D.C. ...

44

Heat flow studies, Coso Geothermal Area, China Lake, California...  

Open Energy Info (EERE)

studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Heat flow studies, Coso Geothermal...

45

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. The laminar flow and turbulent flow have approximately the same optimal frequency, i.e., about 8 Hz. When the pulsation source was placed in the upstream and downstream position, the heat transformation was completed dissimilarly. These results are coincident with previous experiments. The article also gives some information on the applications of the heat transformation by pulse flow in the shell and tube heat exchanger.

Chen, Y.; Zhao, J.

2006-01-01T23:59:59.000Z

46

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca  

Open Energy Info (EERE)

Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Details Activities (0) Areas (0) Regions (0) Abstract: A three-dimensional unsaturated-zone numerical model has been developed to simulate flow and distribution of moisture, gas and heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor, air and heat in the highly heterogeneous, fractured porous rock in the unsaturated zone (UZ). This model is intended for use in the prediction of the current and future conditions in the UZ so

47

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

48

Engineering Fundamentals - Heat Transfer & Fluid Flow, Version 6.0  

Science Conference Proceedings (OSTI)

The Heat Transfer and Fluid Flow module covers basic terms and concepts of heat transfer and fluid flow and discusses their applications in nuclear power plants. This course will help new engineers understand how their work might impact and/or be ...

2013-01-17T23:59:59.000Z

49

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger crystalliser surface  

E-Print Network (OSTI)

Measurement of flow field and local heat transfer distribution on a scraped heat exchanger.ravelet@laposte.net Geert-Jan Witkamp G.J.Witkamp@xs4all.nl Abstract In a cylindrical scraped heat exchanger crystallizer exchanger surface has been studied by direct measurements of the heat exchanger surface temperature

Paris-Sud XI, Université de

50

Heat transfer to impacting drops and post critical heat flux dispersed flow  

E-Print Network (OSTI)

Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

Kendall, Gail E.

1978-01-01T23:59:59.000Z

51

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network (OSTI)

The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two-dimensional flow were solved using the SIMPLE method. The results indicate that the pressure, shear stress, and friction factor under linear heat flux boundary conditions are considerably smoother, and hence, more closely approximate the real situation. As the heat flux increases, the pressure drop increases, but the friction factor demonstrates only a slight change for different heat flux conditions. The size and shape of the micro heat pipe vapor space was shown to have a significant influence on the vapor flow behavior for micro heat pipes. When the vapor space area decreases, the pressure drop, shear stress, and friction factor all significantly increase.

Liu, Xiaoqin

1996-01-01T23:59:59.000Z

52

Heating surface material’s effect on subcooled flow boiling heat transfer of R134a  

Science Conference Proceedings (OSTI)

In this study, subcooled flow boiling of R134a on copper (Cu) and stainless steel (SS) heating surfaces was experimentally investigated from both macroscopic and microscopic points of view. By utilizing a high-speed digital camera, bubble growth rate, bubble departure size, and nucleation site density, were able to be observed and analyzed from the microscopic point of view. Macroscopic characteristics of the subcooled flow boiling, such as heat transfer coefficient, were able to be measured as well. Experimental results showed that there are no obvious difference between the copper and the stainless surface with respect to bubble dynamics, such as contact angle, growth rate and departure size. On the contrary, the results clearly showed a trend that the copper surface had a better performance than the stainless steel surface in terms of heat transfer coefficient. It was also observed that wall heat fluxes on both surfaces were found highly correlated with nucleation site density, as bubble hydrodynamics are similar on these two surfaces. The difference between these two surfaces was concluded as results of different surface thermal conductivities.

Ling Zou; Barclay G. Jones

2012-11-01T23:59:59.000Z

53

Liquid-fluidized-bed heat exchanger flow distribution models  

DOE Green Energy (OSTI)

Allied Chemical Corporation at the Idaho National Engineering Laboratory is developing liquid-fluidized-bed shell-and-tube heat exchangers for geothermal applications. Sand fluidized by geothermal water on the shell side prevents scaling and increases heat transfer coefficients over conventional heat exchangers. Tests were conducted on two instrumented fluidized-bed heat exchanger models, constructed primarily of plexiglass, which differ in tube bundle orientation. One contains a horizontal bundle and the other a vertical tube bundle. Plexiglass construction allowed visual observation of flow patterns. The vertical model proved to have more uniform flow distribution and higher heat transfer coefficients than the horizontal model. The horizontal heat exchanger experienced piling on top of the tubes and areas of poor fluidization existed in the bed. Geometric considerations show that a horizontal design is more conducive to large flow rates than a vertical design. New design concepts for both vertical and horizontal assemblies and recommendations for further developmental work are presented.

Cole, L.T.; Allen, C.A.

1979-01-01T23:59:59.000Z

54

Forced convective flow and heat transfer of upward cocurrent air-water slug flow in vertical plain and swirl tubes  

SciTech Connect

This experimental study comparatively examined the two-phase flow structures, pressured drops and heat transfer performances for the cocurrent air-water slug flows in the vertical tubes with and without the spiky twisted tape insert. The two-phase flow structures in the plain and swirl tubes were imaged using the computerized high frame-rate videography with the Taylor bubble velocity measured. Superficial liquid Reynolds number (Re{sub L}) and air-to-water mass flow ratio (AW), which were respectively in the ranges of 4000-10000 and 0.003-0.02 were selected as the controlling parameters to specify the flow condition and derive the heat transfer correlations. Tube-wise averaged void fraction and Taylor bubble velocity were well correlated by the modified drift flux models for both plain and swirl tubes at the slug flow condition. A set of selected data obtained from the plain and swirl tubes was comparatively examined to highlight the impacts of the spiky twisted tape on the air-water interfacial structure and the pressure drop and heat transfer performances. Empirical heat transfer correlations that permitted the evaluation of individual and interdependent Re{sub L} and AW impacts on heat transfer in the developed flow regions of the plain and swirl tubes at the slug flow condition were derived. (author)

Chang, Shyy Woei [Thermal Fluids Laboratory, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China); Yang, Tsun Lirng [Department of Marine Engineering, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China)

2009-10-15T23:59:59.000Z

55

Heat Flow At Standard Depth | Open Energy Information  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Heat Flow At Standard Depth Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow At Standard Depth Details Activities (2) Areas (1) Regions (0) Abstract: Secular and long-term periodic changes in surface temperature cause perturbations to the geothermal gradient which may be significant to depths of at least 1000 m, and major corrections are required to determine absolute values of heat flow from the Earth's interior. However, detailed climatic models remain contentious and estimates of error in geothermal gradients differ widely. Consequently, regions of anomalous heat flow which

56

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

57

Heat Flow From Four New Research Drill Holes In The Western Cascades...  

Open Energy Info (EERE)

Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four...

58

High-temperature waste-heat-stream selection and characterization  

Science Conference Proceedings (OSTI)

Four types of industrial high-temperature, corrosive waste heat streams are selected that could yield significant energy savings if improved heat recovery systems were available. These waste heat streams are the flue gases from steel soaking pits, steel reheat furnaces, aluminum remelt furnaces, and glass melting furnaces. Available information on the temperature, pressure, flow, and composition of these flue gases is given. Also reviewed are analyses of corrosion products and fouling deposits resulting from the interaction of these flue gases with materials in flues and heat recovery systems.

Wikoff, P.M.; Wiggins, D.J.; Tallman, R.L.; Forkel, C.E.

1983-08-01T23:59:59.000Z

59

Ceramic heat pipes for high temperature heat removal  

SciTech Connect

Difficulties in finding metal or protected metal components that exhibit both strength and corrosion resistance at high temperature have severely restricted the application of effective heat recovery techniques to process heat furnaces. A potential method of overcoming this restriction is to use heat pipes fabricated from ceramic materials to construct counterflow recuperators. A development program has been initiated to demonstrate the technical and eventually the economical feasibility of ceramic heat pipes and ceramic heat pipe recuperators. The prime candidate for heat pipe construction is SiC. Closed-end tubes of this material have been prepared by chemical vapor deposition (CVD). These tubes were lined internally with tungsten by a subsequent CVD operation, partially filled with sodium, and sealed by brazing a tungsten lined SiC plug into the open-end with a palladium--cobalt alloy. Heat pipes constructed in this manner have been successfully operated in vacuum at temperatures of 1225/sup 0/K and in air at a temperature of 1125/sup 0/K. The heat source used initially for the air testing was an induction heated metallic sleeve in thermal contact with the test unit. Subsequent testing has shown that a silicon carbide heat pipe can be successfully operated with natural gas burners providing the input heat. Methods of fabricating and testing these devices are described.

Keddy, E.S.; Ranken, W.A.

1978-01-01T23:59:59.000Z

60

Heat-flow mapping at the Geysers Geothermal Field  

SciTech Connect

Pertinent data were compiled for 187 temperature-gradient holes in the vicinity of The Geysers Geothermal field. Terrain-correction techniques were applied to most of the temperature-gradient data, and a temperature-gradient map was constructed. Cutting samples from 16, deep, production wells were analyzed for thermal conductivity. From these samples, the mean thermal conductivities were determined for serpentinized ultramafic rock, greenstone, and graywacke. Then, a heat flow map was made. The temperature-gradient and heat-flow maps show that The Geysers Geothermal field is part of a very large, northwesterly-trending, thermal anomaly; the commercially productive portion of the field may be 100 km/sup 2/ in area. The rate that heat energy flows through the surface by thermal conduction is estimated at 1.79 x 10/sup 9/MJ per year. The net heat energy loss from commercial production for 1983 is estimated at 180.14 x 10/sup 9/MJ.

Thomas, R.P.

1986-10-31T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Heat Flow And Geothermal Potential In The South-Central United States |  

Open Energy Info (EERE)

And Geothermal Potential In The South-Central United States And Geothermal Potential In The South-Central United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow And Geothermal Potential In The South-Central United States Details Activities (1) Areas (1) Regions (0) Abstract: Geothermal exploration is typically limited to high-grade hydrothermal reservoirs that are usually found in the western United States, yet large areas with subsurface temperatures above 150 deg. C at economic drilling depths can be found east of the Rocky Mountains. The object of this paper is to present new heat flow data and to evaluate the geothermal potential of Texas and adjacent areas. The new data show that, west of the Ouachita Thrust Belt, the heat flow values are lower than east of the fault zone. Basement heat flow values for the Palo Duro and Fort

62

The heat transfer mechanism in aqueous foam flow in a channel  

Science Conference Proceedings (OSTI)

The Heat transfer mechanism in two-phase aqueous foam flow was investigated for developing energy-efficient heat exchangers. Such heat exchangers can provide low consumption of energy resources due to enhanced heat transfer rates. An enhanced heat transfer ... Keywords: aqueous foam flow, heat exchangers, heat transfer

Irena Gabrielaitien?; Jonas Gylys; Rolandas Jonynas; Tadas Ždankus

2011-12-01T23:59:59.000Z

63

Geothermal investigations in Idaho. Part 8. Heat flow study of the Snake River Plain region, Idaho  

DOE Green Energy (OSTI)

The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential.

Brott, C.A.; Blackwell, D.D.; Mitchell, J.C.

1976-09-01T23:59:59.000Z

64

Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps  

E-Print Network (OSTI)

An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced evaporator airflow, and return air leakage from hot attic spaces. There were five sets of tests used for this research: two of them for the charging tests, two for the reduced evaporator airflow, and one for the return air leakage tests. For the charging tests, the indoor room conditions were 80'F (27.8'C) dry-bulb and 50% relative humidity. The outdoor conditions ranged from 95'F (350C) all the way up to 120'F (48.9'C). Charge levels ranged from 30% undercharged to 40% overcharged for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels ranged from-36% charging to +27% charging. Performance was quantified with the following variables: total capacity, energy efficiency ratio (EER), and power. The performance of the orifice unit was more sensitive to charge than it was for the TXV unit. For the TXV unit on the -27% to +27% charging range, the capacity and EER changed little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced evaporator airflow. As evaporator airflow decreased, the capacity and EER both decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or EER dropped more than 25%. Return air leakage from hot attic spaces was simulated by assuming adiabatic mixing of the indoor air at normal conditions with the attic air at high temperatures. Effective capacity and EER both decreased with increased return air leakage. However, power consumption was relatively constant for all variables except outdoor temperature, which meant that for the same power consumption, the unit delivered much lower performance when there was return air leakage. The increase in sensible heat ratio (SHR) with increasing leakage showed perhaps the most detrimental effect of return air leakage on performance, which was the inability of the unit to absorb moisture from the environment.

Rodriguez, Angel Gerardo

1995-01-01T23:59:59.000Z

65

Effect of Refrigerant Charge, Duct Leakage, and Evaporator Air Flow on the High Temperature Performance of Air Conditioners and Heat Pumps  

E-Print Network (OSTI)

An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced evaporator airflow, and return air leakage from hot attic spaces. There were five sets of tests used for this research: two of them for the charging tests, two for the reduced evaporator airflow, and one for the return air leakage tests. For the charging tests, the indoor room conditions were 80°F (27.8°C) dry-bulb and 50% relative humidity. The outdoor conditions ranged from 95°F (35°C) all the way up to 120°F (48.9°C). Charge levels ranged from 30% undercharged to 40% overcharged for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels ranged from -36% charging to +27% charging. Performance was quantified with the following variables: total capacity, energy efficiency ratio (EER), and power. The performance of the orifice unit was more sensitive to charge than it was for the TXV unit. For the TXV unit on the -27% to +27% charging range, the capacity and EER changed little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced evaporator airflow. As evaporator airflow decreased, the capacity and EER both decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or EER dropped more than 25%. Return air leakage from hot attic spaces was simulated by assuming adiabatic mixing of the indoor air at normal conditions with the attic air at high temperatures. Effective capacity and EER both decreased with increased return air leakage. However, power consumption was relatively constant for all variables except outdoor temperature, which meant that for the same power consumption, the unit delivered much lower performance when there was return air leakage. The increase in sensible heat ratio (SHR) with increasing leakage showed perhaps the most detrimental effect of return air leakage on performance, which was the inability of the unit to absorb moisture from the environment.

Rodriguez, Angel Gerardo

2007-11-29T23:59:59.000Z

66

Brine flow in heated geologic salt.  

Science Conference Proceedings (OSTI)

This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

Kuhlman, Kristopher L.; Malama, Bwalya

2013-03-01T23:59:59.000Z

67

Dispersed-Flow Film Boiling Heat Transfer Data near Spacer Grids in a Rod Bundle  

Science Conference Proceedings (OSTI)

Technical Paper / Radiation Effects and Their Relationship to Geological Repository / Heat Transfer and Fluid Flow

Graydon L. Yoder; Jr.; David G. Morris; Charles B. Mullins; Larry J. Ott

68

Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report  

DOE Green Energy (OSTI)

The present research effort at the Coso Geothermal Area located on the China Lake Naval Weapons Center, China Lake, California, was concerned with: (1) heat flow studies and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical resistivity data. Difficulty was encountered in the drilling of all of the holes due to altered, porous, faulted, and sometime highly fractures zones. Thermal conductivity measurements were completed using both the needle probe technique and the divided bar apparatus with a cell arrangement. Heat flow values were obtaned by combining equilibrium temperature measurements with the appropriate thermal conductivity values. Heat, in the upper few hundred meters of the subsurface associated with the Coso Geothermal Area, is being transferred by a conductive heat transfer mechanism with a value of approximately 15 ..mu..cal/cm/sup 2/-sec. This is typical of geothermal systems throughout the world and is approximately ten times the normal terrestrial heat flow of 1.5 HFU. The background heat flow for the Coso region is about 3.5 HFU.

Combs, J.

1975-01-01T23:59:59.000Z

69

Heat flow and microearthquake studies, Coso Geothermal Area, China Lake,  

Open Energy Info (EERE)

and microearthquake studies, Coso Geothermal Area, China Lake, and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Book: Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report Details Activities (2) Areas (1) Regions (0) Abstract: The present research effort at the Coso Geothermal Area located on the China Lake Naval Weapons Center, China Lake, California, was concerned with: (1) heat flow studies and (2) microearthquake studies associated with the geothermal phenomena in the Coso Hot Springs area. The sites for ten heat flow boreholes were located primarily using the available seismic ground noise and electrical resistivity data. Difficulty was encountered in the drilling of all of the holes due to altered, porous,

70

Heat flow studies, Coso Geothermal Area, China Lake, California. Technical  

Open Energy Info (EERE)

studies, Coso Geothermal Area, China Lake, California. Technical studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Heat flow studies, Coso Geothermal Area, China Lake, California. Technical report Details Activities (1) Areas (1) Regions (0) Abstract: Heat flow studies in the Coso Geothermal Area were conducted at China Lake, California. Temperature measurements were completed in nine of the heat flow boreholes. Temperatures were measured at five meter intervals from the ground surface to the deepest five meter interval. Subsequently, temperatures were remeasured two or three times in each borehole in order to demonstrate that equilibrium thermal conditions existed. The maximum difference in temperature, at any of the five meter intervals, was 0.03 deg

71

Control of reactor coolant flow path during reactor decay heat removal  

DOE Patents (OSTI)

An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

Hunsbedt, Anstein N. (Los Gatos, CA)

1988-01-01T23:59:59.000Z

72

New shear-free relativistic models with heat flow  

E-Print Network (OSTI)

We study shear-free spherically symmetric relativistic models with heat flow. Our analysis is based on Lie's theory of extended groups applied to the governing field equations. In particular, we generate a five-parameter family of transformations which enables us to map existing solutions to new solutions. All known solutions of Einstein equations with heat flow can therefore produce infinite families of new solutions. In addition, we provide two new classes of solutions utilising the Lie infinitesimal generators. These solutions generate an infinite class of solutions given any one of the two unknown metric functions.

A. M. Msomi; K. S. Govinder; S. D. Maharaj

2012-12-29T23:59:59.000Z

73

Prediction of strongly-heated internal gas flows  

Science Conference Proceedings (OSTI)

The purposes of the present article are to remind practitioners why the usual textbook approaches may not be appropriate for treating gas flows heated from the surface with large heat fluxes and to review the successes of some recent applications of turbulence models to this case. Simulations from various turbulence models have been assessed by comparison to the measurements of internal mean velocity and temperature distributions by Shehata for turbulent, laminarizing and intermediate flows with significant gas property variation. Of about fifteen models considered, five were judged to provide adequate predictions.

McEligot, D.M. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.]|[Univ. of Arizona, Tucson, AZ (United States)]|[Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Shehata, A.M. [Xerox Corp., Webster, NY (United States); Kunugi, Tomoaki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)]|[Tokai Univ., Hiratsuka, Kanagawa (Japan)

1997-12-31T23:59:59.000Z

74

Calibration of High Heat Flux Sensors at NIST  

Science Conference Proceedings (OSTI)

... sides and uniform distri- bution of flow across the tube cross section, the ... is beneficial in minimizing the stagnation point flow heat transfer effects on ...

2012-10-18T23:59:59.000Z

75

Comparison of calculated results from two analytical models with measured data from a heat-exchanger flow test  

SciTech Connect

Predicted results from both a network flow model and a turbulent flow model were compared with measured results from an air flow test on a half-scale model of the auxiliary heat exchanger for a high-temperature gas-cooled reactor. Measurements of both velocity and pressure were made within the heat exchanger shell side flow field. These measurements were compared with calculated results from both a network flow model and a turbulent flow model. Both analytical models predicted early identical results which, except for some minor anomalies, compared favorably with the measured data.

Carosella, D.P.; Pavlics, P.N.

1983-05-01T23:59:59.000Z

76

Two-Dimensional Response of a Stably Stratified Shear Flow to Diabatic Heating  

Science Conference Proceedings (OSTI)

A two-dimensional, linearized problem in a stratified shell flow with either isolated heating or differential heating is investigated. In response to isolated heating with the heating top below the wind reversal height, the low-level vertical ...

Yuh-Lang Lin

1987-05-01T23:59:59.000Z

77

Self-heating in kinematically complex magnetohydrodynamic flows  

SciTech Connect

The non-modal self-heating mechanism driven by the velocity shear in kinematically complex magnetohydrodynamic (MHD) plasma flows is considered. The study is based on the full set of MHD equations including dissipative terms. The equations are linearized and unstable modes in the flow are looked for. Two different cases are specified and studied: (a) the instability related to an exponential evolution of the wave vector and (b) the parametric instability, which takes place when the components of the wave vector evolve in time periodically. By examining the dissipative terms, it is shown that the self-heating rate provided by viscous damping is of the same order of magnitude as that due to the magnetic resistivity. It is found that the heating efficiency of the exponential instability is higher than that of the parametric instability.

Osmanov, Zaza; Rogava, Andria [Centre for Theoretical Astrophysics, ITP, Ilia State University, 0162-Tbilisi (Georgia); Poedts, Stefaan [Centre for Plasma Astrophysics, Katholieke Universiteit Leuven, Celestijnenlaan 200B, Bus 2400 B-3001 (Belgium)

2012-01-15T23:59:59.000Z

78

Flow and heat transfer in gas turbine disk cavities subject to nonuniform external pressure field  

SciTech Connect

Ingestion of hot gas from the main-stream gas path into turbine disk cavities, particularly the first-stage disk cavity, has become a serious concern for the next-generation industrial gas turbines features high rotor inlet temperature. Fluid temperature in the cavities increases further due to windage generated by fluid drag at the rotating and stationary surfaces. The resulting problem of rotor disk heat-up is exacerbated by the high disk rim temperature due to adverse (relatively flat) temperature profile of the mainstream gas in the annular flow passage of the turbine. This describes an investigation into local convective heat transfer coefficient and cooling effectiveness of the rotor disk, flow field in the disk cavity, computation of the flow field and heat transfer in the disk cavity, and mainstream gas injection and rotor disk cooling effectiveness by mass transfer analogy.

Roy, R.P.; Kim, Y.W.; Tong, T.W. [Arizona State Univ., Tempe, AZ (United States). Dept. of Mechanical and Aerospace Engineering

1995-12-31T23:59:59.000Z

79

Relationship Between Heat Flows and Geological Structures in the Sichuan Basin, P.R. China  

DOE Green Energy (OSTI)

Based on an extensive data collection and analysis, this research has provided reliable representations of the features of the geothermal fields, their heat flow, and relationships with geological structures in the Sichuan Basin. The isotherms below a depth of 1,000 m show high values in the Central Uplift and the Southwest Uplift, and low values in the Northwest and Southeast Depressions. These features probably indicate undulation of crystalline basement and structural depression. At depths greater than 3,000 m, the isotherms tend to become simpler and regionalized. The mean heat flow in the basin is 69.1 mW/m{sup 2}. In the Central Uplift, the Northwest Depression and the East of the basin, heat-flow values range from 58.6 to 71.2 mW/m{sup 2}, with a mean value of 66.1 mWE/m{sup 2}. In the south and southwest, it varies from 76.6 to 100.5 mW/m{sup 2}, with a mean value of 86.2 mW/m{sup 2}. High heat-flow values occur within the uplift of the crystalline basement in the southwest Sichuan, and the heat flow decreases from the south, through the central area, to the northwest.

Zeng, Y.; Yu, H.; Wang, X.

1995-01-01T23:59:59.000Z

80

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,with fluid and heat flow in fractured porous media arefluid and heat flow in porous media, heat pipe, reservoir simulation, fractured

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Modeling of fluid and heat flow in fractured geothermal reservoirs  

DOE Green Energy (OSTI)

In most geothermal reservoirs large-scale permeability is dominated by fractures, while most of the heat and fluid reserves are stored in the rock matrix. Early-time fluid production comes mostly from the readily accessible fracture volume, while reservoir behavior at later time depends upon the ease with which fluid and heat can be transferred from the rock matrix to the fractures. Methods for modeling flow in fractured porous media must be able to deal with this matrix-fracture exchange, the so-called interporosity flow. This paper reviews recent work at Lawrence Berkeley Laboratory on numerical modeling of nonisothermal multiphase flow in fractured porous media. We also give a brief summary of simulation applications to problems in geothermal production and reinjection. 29 refs., 1 fig.

Pruess, K.

1988-08-01T23:59:59.000Z

82

Supersonic combustion of a transverse injected H sub 2 jet in a radio frequency heated flow  

DOE Green Energy (OSTI)

The combustion of a single hydrogen jet, normally injected into a radio frequency (RF) heated, oxidant-containing, supersonic flow, has been established to characterize the chemical and fluid dynamic phenomena associated with the reaction process and ultimately validate the predictive capability of computational computer dynamic (CFD) codes. The experimental system employed for this study is unique in that it uses an electrodeless, inductively coupled plasma tube to generate the high temperature oxidant-containing gas for subsequent nozzle expansion. Advantages of an RF heated flow system include reduced free-stream chemical contamination, continuous operation, and relative ease of integration into a typical flow laboratory environment. A description of the system utilized for this study is presented including preliminary results of the reactive flow characterization. In addition, the use of the laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), for measuring flow properties is also discussed. 8 refs., 7 figs.

Wantuck, P.J.; Tennant, R.A.; Watanabe, H.H.

1991-01-01T23:59:59.000Z

83

Heat flow and geothermal potential of Kansas  

DOE Green Energy (OSTI)

The plan of the US Geological Survey and Kansas Geological Survey to drill four deep hydrologic tests in Kansas prompted a geothermal study in these wells. These wells were drilled through the Arbuckle Group to within a few feet of basement and two of the holes were deepened on into the basement and core samples collected of the basement rock. Because of the depth of the four holes and because of the fact that they have been cased through most of their depth and left undisturbed to reach temperature equilibrium, it is possible to get highly accurate, stable temperature measurements through the complete sedimentary section. In addition an extensive suite of geophysical logs were obtained for each of the holes (gamma-ray, travel time, density, neutron porosity, electric, etc.) and cuttings were collected at frequent intervals. In addition 5 other holes were logged as part of this study. For these holes cutting samples and geophysical logs are not available, but the additional holes offer useful supplementary information on the temperature regime in other parts of Kansas.

Blackwell, D.D.; Steele, J.L.

1981-01-01T23:59:59.000Z

84

Critical heat-flux experiments under low-flow conditions in a vertical annulus. [PWR; BWR; LMFBR  

Science Conference Proceedings (OSTI)

An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF.

Mishima, K.; Ishii, M.

1982-03-01T23:59:59.000Z

85

An experimental study of the flow and heat transfer between enhanced heat transfer plates for PHEs  

Science Conference Proceedings (OSTI)

The flow and heat transfer between inclined discrete rib plates for plate heat exchangers have been experimentally studied. Dye injection method is used to visualize the flow structures. The visualization results show that front vortex, rear vortex and main vortex are formed between the plates. The rib parameter influence is also studied using visualization method. The pressure drop and heat transfer between the inclined discrete rib plates as well as that between inclined continuous rib plates and smooth plates are also measured. The measured results show that the inclined discrete rib plate can enhanced heat transfer 20-25% at the same pumping power compared with the commonly used inclined continuous rib plates. (author)

Li, Xiao-wei [Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Meng, Ji-an; Li, Zhi-xin [School of Aerospace, Tsinghua University, Beijing 100084 (China)

2010-11-15T23:59:59.000Z

86

Enhanced Heat Flow in the Hydrodynamic Collisionless Regime  

SciTech Connect

We study the heat conduction of a cold, thermal cloud in a highly asymmetric trap. The cloud is axially hydrodynamic, but due to the asymmetric trap radially collisionless. By locally heating the cloud we excite a thermal dipole mode and measure its oscillation frequency and damping rate. We find an unexpectedly large heat conduction compared to the homogeneous case. The enhanced heat conduction in this regime is partially caused by atoms with a high angular momentum spiraling in trajectories around the core of the cloud. Since atoms in these trajectories are almost collisionless they strongly contribute to the heat transfer. We observe a second, oscillating hydrodynamic mode, which we identify as a standing wave sound mode.

Meppelink, R.; Rooij, R. van; Vogels, J. M.; Straten, P. van der [Atom Optics and Ultrafast Dynamics, Utrecht University, P.O. Box 80000, 3508 TA Utrecht (Netherlands)

2009-08-28T23:59:59.000Z

87

Optical techniques for fluid flow and heat transfer  

Science Conference Proceedings (OSTI)

A review is presented of optical measuring techniques employed in momentum heat and mass transfer studies. A classification is given of those techniques that are nowadays widely employed in studies to advance the understanding of transport phenomena in fluids. Techniques that employ effects caused by fluid molecules are briefly treated, and examples of measurements are given to demonstrate the kind of information that can be obtained by these techniques. Optical techniques using tracers to obtain transport information are summarized, and laser-Doppler anemometry and its application to fluid flow studies are emphasized. Applications of this technique in single-phase and two-phase flows are given that demonstrate its potential in experimental fluid mechanics and convective heat transfer studies. 63 refs.

Durst, F. (Erlangen-Nuernberg Universitaet, Erlangen (Germany, F.R.))

1990-01-01T23:59:59.000Z

88

Conductive heat flow in the Randsburg area, California  

DOE Green Energy (OSTI)

The Randsburg known Geothermal Resource Area (KGRA) is located in a tectonically active part of the Mojave Desert just south of the Garlock Fault. To provide background information for geothermal resource appraisal, the results from five holes drilled for regional heat-flow reconnaissance (USGS, unpublished data) were combined with data from nine additional holes drilled especially as part of this study in an attempt to delineate the conductive thermal anomaly associated with observed geothermal manifestations in the Randsburg area.

Sass, J.H.; Galanis, S.P. Jr.; Marshall, B.V.; Lachenbruch, A.H.; Munroe, R.J.; Moses, T.H. Jr.

1978-01-01T23:59:59.000Z

89

Protected Loss of Flow Transient Simulation (Quicktime format, High  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineering Analysis > Videos Engineering Analysis > Videos Engineering Analysis: Protected Loss of Flow Transient Simulation Quicktime format Quicktime Format - High Bandwidth | Size: 25.94 MB | Bit Rate: 1148 kbps Keywords: flow transient, plot, EBR-II, SAS4A, SASSYS-1, passive safety, protected loss of flow, PLOF, shutdown heat removal test, SHRT-17, SHRT17 Elevation plot showing detailed top of core temperatures in experimental assembly XX09 during a protected loss of flow transient in EBR-II. Surrounding assemblies are depicted using fuel average temperatures. Results show excellent decay heat removal capability of sodium through natural circulation and exceptionally low transient temperatures with metallic fuel. :: Please wait until video loads completely :: Closed Captioning Transcript

90

Ohmically heated high-density Z pinch  

SciTech Connect

The gross properties of a high-density (n approximately equal to 10$sup 27$ m$sup -3$), small-radius, (r = 10$sup -4$ m) gas-imbedded Z pinch have been examined considering only classical processes. The rate equation using only ohmic heating along with bremsstrahlung and radial heat transport shows that ohmic heating will rapidly take the pinch to thermonuclear temperatures for currents, I, greater than 1 MA. The radial heat loss for the pinch is very small for I greater than 1.5 MA. This suggests that the pinch could tolerate being driven to a nearby wall by an m = 1 kink. The laser technology for initiation of the small-diameter filament and the high-voltage technology for giving a 30-ns rise to a MA or more are available now. Some reactor considerations have been included. (auth)

Hammel, J.E.

1976-01-01T23:59:59.000Z

91

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

92

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

93

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

94

STABLE HEATING OF CLUSTER COOLING FLOWS BY COSMIC-RAY STREAMING  

SciTech Connect

We study heating of cool cores in galaxy clusters by cosmic-ray (CR) streaming using numerical simulations. In this model, CRs are injected by the central active galactic nucleus (AGN) and move outward with Alfven waves. The waves are excited by the streaming itself and become nonlinear. If magnetic fields are large enough, CRs can prevail in and heat the entire core because of a large Alfven velocity. We find that the CR streaming can stably heat both high- and low-temperature clusters for a long time without the assistance of thermal conduction, and it can prevent the development of massive cooling flows. If there is even a minor contribution from thermal conduction, the heating can be stabilized further. We discuss the reason for the stability and indicate that the CR pressure is insensitive to changes in the intracluster medium (ICM) and that the density dependence of the heating term is similar to that of radiative cooling.

Fujita, Yutaka [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Ohira, Yutaka, E-mail: fujita@vega.ess.sci.osaka-u.ac.jp [Theory Centre, Institute of Particle and Nuclear Studies, KEK, 1-1 Oho, Tsukuba 305-0801 (Japan)

2011-09-10T23:59:59.000Z

95

Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K  

E-Print Network (OSTI)

Lau, W, and Yang, S. , “A Heat Exchanger between Forced FlowWITHIN A CYLINDRICAL HEAT EXCHANGER COOLED TO 14 K S. Qof the container is a heat exchanger between the hydrogen

Yang, S.W.; Oxford U.

2004-01-01T23:59:59.000Z

96

Estimation of heat transfer in oscillating annular flow using artifical neural networks  

Science Conference Proceedings (OSTI)

In this study, the prediction of heat transfer from a surface having constant heat flux subjected to oscillating annular flow is investigated using artificial neural networks (ANNs). An experimental study is carried out to estimate the heat transfer ... Keywords: Annular duct, Artificial neural network, Heat transfer, Oscillating flow

Unal Akdag; M. Aydin Komur; A. Feridun Ozguc

2009-09-01T23:59:59.000Z

97

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

22]. Fluid flow and heat-transfer processes in a two-phase,processes associated with multiphase flow and heat transferprocesses has also motivated development of fluid flow and heat transfer

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

98

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

fluid flow and heat-transfer processes. The physicalcoupled fluid-flow and heat-transfer processes has proven toin which flow and heat transfer processes along drifts are

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

99

Numerical study of flow and heat transfer in 3D serpentine channels using colocated grids  

E-Print Network (OSTI)

channels, which have applications in heat-exchangers, were studied. A finite-volume code in FORTRAN was developed to solve this problem. Modules were made for generating rids in the domain, for valving the flow velocities and pressure, for solving temperature field and for post-processing the results. For solving the flow field, colocated grid formulation was used as opposed to the staggered-grid formulation, and the SIMPLE algorithm was used to link the velocity and pressure. The line-by-line method was used to solve the algebraic equations. The geometry of the problem facilitated the application of periodic inverted symmetry boundary condition. Since this is a forced convection problem, the flow field was solved first and the converged velocity field was input to the temperature solver module. The temperature field was solved for the uniform-wall-heat-flux boundary condition. The post-processing module obtained the overall friction-factor, which is representative of the pressure drop, the local and average Nusselt number. The numerical code developed was validated by solving for fully developed flow and heat transfer in a square straight channel. Grid-independent solution was established for a reference case of serpentine channel with the highest Reynolds number (Re=200). Periodically fully developed flow and heat transfer in serpentine channels were salved for different geometry parameters, for different Reynolds numbers and for two different Prandtl numbers ( 0.7 and 7.0 for air and water respectively). The results were plotted to study the effect of the independent parameters on the pressure drop and the heat transfer performance. The friction factor increased as the amplitude of the serpentine channel and the Reynolds number were increased. Similar trend was observed for the heat transfer coefficients. High heat transfer coefficients are observed at certain regions in the serpentine channels which are explained by the impingement phenomena. High Prandtl number (=7.0) gives higher heat transfer coefficients than the low Pr (=0.7) because of the thinner thermal boundary layer. The enhancement of heat transfer mechanism was explained by studying the plotted flow-field velocity vectors in different planes.

Chintada, Sailesh Raju

1998-01-01T23:59:59.000Z

100

High precision high flow range control valve  

DOE Patents (OSTI)

A fluid control valve is described having a valve housing having first and second valve housing openings for the ingress and egress of fluid through the control valve. Disposed within a void formed by the control valve is a sleeve having at least one sleeve opening to permit the flow of fluid therethrough. A flow restricter travels within the sleeve to progressively block off the sleeve opening and thereby control flow. A fluid passageway is formed between the first valve housing opening and the outer surface of the sleeve. A second fluid passageway is formed between the inside of the sleeve and the second valve housing opening. Neither fluid passageway contains more than one 90.degree. turn. In the preferred embodiment only one of the two fluid passageways contains a 90.degree. turn. In another embodiment, the control valve housing is bifurcated by a control surface having control surface opening disposed therethrough. A flow restricter is in slidable contact with the control surface to restrict flow of fluid through the control surface openings.

McCray, John A. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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.


101

Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads  

Science Conference Proceedings (OSTI)

The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits

2012-01-01T23:59:59.000Z

102

Heat flow patterns of the North American continent: A discussion of the DNAG Geothermal Map of North America  

DOE Green Energy (OSTI)

The large and small-scale geothermal features of the North American continent and surrounding ocean areas illustrated on the new 1:5,000,000 DNAG Geothermal Map of North America are summarized. Sources for the data included on the map are given. The types of data included are heat flow sites coded by value, contours of heat flow with a color fill, areas of major groundwater effects on regional heat flow, the top-of-geopressure in the Gulf Coast region, temperature on the Dakota aquifer in the midcontinent, location of major hot springs and geothermal systems, and major center of Quaternary and Holocene volcanism. The large scale heat flow pattern that is well known for the conterminous United States and Canada of normal heat flow east of the Cordillera and generally high heat flow west of the front of the Cordillera dominates the continental portion of the map. However, details of the heat flow variations are also seen and are discussed briefly in this and the accompanying papers.

Blackwell, David D.; Steele, John L.; Carter, Larry C.

1990-01-01T23:59:59.000Z

103

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

Flow, Transport, and Heat Transfer in Porous and Fracturedtransport, and heat transfer in porous and fracturedflow, chemical transport, and heat transfer in rock. These

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

104

Microscale flow visualization of nucleate boiling in small channels: Mechanisms influencing heat transfer  

SciTech Connect

This paper describes the use of a new test apparatus employing flow visualization via ultra-high-speed video and microscope optics to study microscale nucleate boiling in a small, rectangular, heated channel. The results presented are for water. Because of confinement effects produced by the channel cross section being of the same nominal size as the individual vapor bubbles nucleating at discrete wall sites, flow regimes and heat transfer mechanisms that occur in small channels are shown to be considerably different than those in large channels. Flow visualization data are presented depicting discrete bubble/bubble and bubble/wall interactions for moderate and high heat flux. Quantitative data are also presented on nucleate bubble growth behavior for a single nucleation site in the form of growth rates, bubble sizes, and frequency of generation in the presence and absence of a thin wall liquid layer. Mechanistic boiling behavior and trends are observed which support the use of this type of research as a powerful means to gain fundamental insights into why, under some conditions, nucleate boiling heat transfer coefficients are considerably larger in small channels than in large channels.

Kasza, K.E.; Didascalou, T.; Wambsganss, M.W.

1997-07-01T23:59:59.000Z

105

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES  

E-Print Network (OSTI)

PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES A Thesis Submitted April 1995 #12;PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES by Xiangwei Zhao Abstract The steady and time-dependentbehavior of a single-row heat exchanger with water and air in the in

Sen, Mihir

106

Artificial neural network control of a heat exchanger in a closed flow air circuit  

Science Conference Proceedings (OSTI)

This paper experimentally investigates the control of a heat exchanger in a closed flow air circuit. The temperature inside the test section of the test facility has been maintained at a set value by variation of air flow rate over the heat exchanger ... Keywords: Air circuit, Heat exchanger, Multi-layer perceptron, Neural network control, PID control

Kapil Varshney; P. K. Panigrahi

2005-07-01T23:59:59.000Z

107

Heat flow and hot dry rock geothermal resources of the Clearlake Region, northern California  

DOE Green Energy (OSTI)

The Geysers-Clear Lake geothermal anomaly is an area of high heat flow in northern California. The anomaly is caused by abnormally high heat flows generated by asthenospheric uplift and basaltic magmatic underplating at a slabless window created by passage of the Mendocino Triple Junction. The Clear Lake volcanic field is underlain by magmatic igneous bodies in the form of a stack of sill-form intrusions with silicic bodies generally at the top and basic magmas at the bottom. The tabular shape and wide areal extent of the heat sources results in linear temperature gradients and near-horizontal isotherms in a broad region at the center of the geothermal anomaly. The Hot Dry Rock (HDR) portion of The Geysers-Clear Lake geothermal field is that part of the geothermal anomaly that is external to the steamfield, bounded by geothermal gradients of 167 mW/m2 (4 heat flow units-hfu) and 335 mW/m2 (8 hfu). The HDR resources, to a depth of 5 km, were estimated by piece-wise linear summation based on a sketch map of the heat flow. Approximately, the geothermal {open_quotes}accessible resource base{close_quotes} (Qa) is 1.68E+21 J; the {open_quotes}HDR resource base{close_quotes} (Qha) is 1.39E+21 J; and the {open_quotes}HDR power production resource{close_quotes} (Qhp) is 1.01E+21 J. The HDR power production resource (Qhp) is equivalent to 2.78E+ 11 Mwht (megawatt hours thermal), or 1.72E+11 bbls of oil.

Burns, K.L.

1996-08-01T23:59:59.000Z

108

High-bandwidth continuous-flow arc furnace  

DOE Patents (OSTI)

A high-bandwidth continuous-flow arc furnace for stream welding applications includes a metal mass contained in a crucible having an orifice. A power source charges an electrode for generating an arc between the electrode and the mass. The arc heats the metal mass to a molten state. A pressurized gas source propels the molten metal mass through the crucible orifice in a continuous stream. As the metal is ejected, a metal feeder replenishes the molten metal bath. A control system regulates the electrode current, shielding gas pressure, and metal source to provide a continuous flow of molten metal at the crucible orifice. Independent control over the electrode current and shield gas pressure decouples the metal flow temperature and the molten metal flow rate, improving control over resultant weld characteristics. 4 figs.

Hardt, D.E.; Lee, S.G.

1996-08-06T23:59:59.000Z

109

Heat Treatment of High Pressure Die Castings; Challenges and ...  

Science Conference Proceedings (OSTI)

High Strength Aluminum Brazing Sheets for Condenser Fins of Automotive Heat Exchangers · High Temperature Creep Characterization of A380 Cast ...

110

Liquid Metal, a Heat Transport Fluid for High Temperature Solar ...  

Science Conference Proceedings (OSTI)

The need for high efficiency and direct heat conversion into hydrogen, process heat and energy storage pushes the temperature for solar concentrator systems.

111

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

of multiphase, multicomponent fluid mixtures in porous andmultiphase heat and mass flow in unsaturated fractured porous

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

112

Heat Flow Database Expansion for NGDS Data Development, Collection and  

Open Energy Info (EERE)

Database Expansion for NGDS Data Development, Collection and Database Expansion for NGDS Data Development, Collection and Maintenance Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance Project Type / Topic 1 Recovery Act: Geothermal Technologies Program Project Type / Topic 2 Geothermal Data Development, Collection, and Maintenance Project Description In particular the efforts on document and core digitization, the recovery of the BEG geopressure data developed during the approximately $200 million project by DOE in the 1970-1980, the EGS data from the Fenton Hill experiments, and meta-data associated with US thermal mapping are crucial to be performed at this point because they are otherwise in danger of deterioration or complete loss.

113

Flow over Heated Terrain. Part I: Linear Theory and Idealized Numerical Simulations  

Science Conference Proceedings (OSTI)

The flow past heated topography is examined with both linear and nonlinear models. It is first shown that the forcing of an obstacle with horizontally homogenous surface heating can be approximated by the forcing of an obstacle with surface ...

N. Andrew Crook; Donna F. Tucker

2005-09-01T23:59:59.000Z

114

A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus  

SciTech Connect

This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

Raustad, Richard A. [Florida Solar Energy Center

2013-01-01T23:59:59.000Z

115

High heating oil prices discourage heating oil supply contracts ...  

U.S. Energy Information Administration (EIA)

EIA's Short-Term Energy and Winter Fuels Outlook expects the U.S. home heating oil price will average $3.71 per gallon for the season, ...

116

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...  

Open Energy Info (EERE)

repository. The modeling approach is based on a mathematical formulation of coupled multiphase, multicomponent fluid and heat flow through porous and fractured rock. Fracture...

117

Continuous flow microwave heating : evaluation of system efficiency and enzyme inactivation kinetics.  

E-Print Network (OSTI)

??A continuous flow microwave heating system was set up by using one domestic microwave oven (1000W nominal output at 2450MHz). Water was run through the… (more)

Lin, Man Guang, 1966-

2004-01-01T23:59:59.000Z

118

The Development of a Non-Equilibrium Dispersed Flow Film Boiling Heat Transfer Modeling Package.  

E-Print Network (OSTI)

??The dispersed flow film boiling (DFFB) heat transfer regime is important to several applications including cryogenics, rocket engines, steam generators, and in the safety analysis… (more)

Meholic, Michael

2011-01-01T23:59:59.000Z

119

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… (more)

Westheimer, David Thomas

2012-01-01T23:59:59.000Z

120

Heat transfer issues in high-heat-load synchrotron x-ray beams  

SciTech Connect

In this paper, a short description of the synchrotron radiation x-ray sources and the associated power loads is given, followed by a brief description of typical synchrotron components and their heat load. It is emphasized that the design goals for most of these components is to limit (a) temperature, (b) stresses, or (c) strains in the system. Each design calls for a different geometry, material selection, and cooling scheme. Cooling schemes that have been utilized so far are primarily single phase and include simple macrochannel cooling, microchannel cooling, contact cooling, pin-post cooling, porous-flow cooling, jet cooling, etc. Water, liquid metals, and various cryogenic coolants have been used. Because the trend in x-ray beam development is towards brighter (i.e., more powerful) beams and assuming that no radical changes in the design of x-ray generating machines occurs in the next few years, it is fair to state that the utilization of various effective cooling schemes and, in particular, two-phase flow (e.g., subcooled boiling) warrants further investigation. This, however, requires a thorough examination of stability and reliability of two-phase flows for high-heat-flux components operating in ultrahigh vacuum with stringent reliability requirements.

Khounsary, A.M.; Mills, D.M.

1994-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Heat Flow From Four New Research Drill Holes In The Western Cascades,  

Open Energy Info (EERE)

From Four New Research Drill Holes In The Western Cascades, From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Details Activities (1) Areas (1) Regions (0) Abstract: Conceptual models of the thermal structure of the Oregon Cascade Range propose either (1) a narrow zone of magmatic heat sources, flanked by shallow heat-flow anomalies caused by lateral ground-water flow; or (2) a wide zone of magmatic heat sources, with localized, generally negligible ground-water effects. The proposed narrow heat source coincides with the Quaternary volcanic arc, whereas the wider heat source would extend 10-30 km west of the arc. To test the models, four new heat-flow holes were sited

122

Pressure recovery in a cylindrical heat pipe at high radial Reynolds numbers and at high Mach numbers  

SciTech Connect

The pressure recovery in a cylindrical heat pipe has been investigated. The experiments cover average radial Reynolds numbers between 5 and 150 and average Mach numbers up to the velocity of sound. During preliminary experiments in a cylindrical, gravity-assisted heat pipe at high Mach numbers large condensate flow instabilities were observed. As a consequence the heat pipe power varied strongly. Based on these observations an improved heat pipe design was made that resulted in steady operating conditions throughout the entire parameter range. This heat pipe is described. The pressure recovery was measured and compared with results from a two-dimensional analytical model for describing compressible vapor flow in heat pipes. Good agreement with the experimental data was found.

Haug, F.; Busse, C.A.

1985-01-01T23:59:59.000Z

123

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

124

High temperature heat pipes for waste heat recovery  

SciTech Connect

Operation of heat pipes in air at temperatures above 1200/sup 0/K has been accomplished using SiC as a shell material and a chemical vapor deposit (CVD) tungsten inner liner for protection of the ceramic from the sodium working fluid. The CVD tungsten has been used as a distribution wick for the gravity assisted heat pipe through the development of a columnar tungsten surface structure, achieved by control of the metal vapor deposition rate. Wick performance has been demonstrated in tests at approximately 2 kW throughput with a 19-mm-i.d. SiC heat pipe. Operation of ceramic heat pipes in repeated start cycle tests has demonstrated their ability to withstand temperature rise rates of greater than 1.2 K/s.

Merrigan, M.A.; Keddy, E.S.

1980-01-01T23:59:59.000Z

125

Experimental shellside flow visualization in a shell and tube heat exchanger  

E-Print Network (OSTI)

Shell and tube heat exchangers are an extremely effective and mechanically feasible method of transferring thermal energy between two fluids. There is great demand for effective design methods capable of producing highly efficient models. To further improve efficiency, there must be an increased understanding of the physics of shellside flow at a local level. To accomplish this end, an experimental investigation was conducted to obtain flow visualization and internal local pressure drop 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 2.21 L/s were studied. Flow visualization photographs confirmed the existence of leakage streams and recirculation zones. Anomalous vortices were also detected under certain circumstances. Global experimental pressure drops were in good agreement with values predicted from other methods. Local internal pressure dro s were also recorded for the first time and were in good agreement with what would be expected from conventional theory.

Fischer, Matthew Winslow

1998-01-01T23:59:59.000Z

126

High Heating Rate Thermal Desorption for Molecular Surface ...  

High Heating Rate Thermal Desorption for Molecular Surface Sampling Note: The technology described above is an early stage opportunity. Licensing ...

127

Temperature-gradient and heat flow data, Grass Valley, Nevada  

DOE Green Energy (OSTI)

A series of 16 shallow and intermediate-depth temperature-gradient holes were drilled for Sunoco Energy Development Co. in Grass Valley, Pershing County, Nevada, on leases held by Aminoil USA, Inc., under the cost-sharing industry-linked program of the Department of Energy. Thirteen shallow (85-152 m) and 3 intermediate-depth (360-457 m) holes were completed and logged during the period June through September, 1979. The locations of these holes and of pre-existing temperature-gradient holes are shown on plate 1. This report constitutes a final data transmittal and disclosure of results. The drilling subcontractor was Southwest Drilling and Exploration, Inc. of Central, Utah. They provided a Gardner-Denver 15W rig, a 3-man crew, and supporting equipment. A l l holes were drilled with mud as the circulating medium. Drilling histories for each hole are summarized in table 1. GeothermEx, Inc. performed on-site geological descriptions of the cuttings; obtained several temperature profiles for each hole, including an equilibrium profile taken 23 days or more after cessation of drilling; selected samples for thermal conductivity measurements; integrated temperature, temperature-gradient, and heat-flow data obtained in this project with published values; and prepared this report.

Koenig, James B.; Gardner, Murray C.

1979-11-01T23:59:59.000Z

128

Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal  

Open Energy Info (EERE)

Resource-Reservoir Investigations Based On Heat Flow And Thermal Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Details Activities (2) Areas (2) Regions (0) Abstract: Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of

129

Heat flow in the northern Basin and Range province | Open Energy  

Open Energy Info (EERE)

in the northern Basin and Range province in the northern Basin and Range province Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat flow in the northern Basin and Range province Abstract The heat flow in the Basin and Range province of northern Nevada is extremely complex. It is a product of superposition of the regional effects of extension and volcanism /intrusion modified by the local conductive effects of thermal refraction (complicated structural settings),variations in radioactive heat production, erosion and sedimentation. In addition to these conductive effects,groundwater flow, both on a local and a regional basis,affects heat-flow measurements. Typical heat -flow values for the Basin and Range province average 85 +/- 10 mWm-2. The higher estimates are

130

New heat-flow contour map of the conterminous United States  

DOE Green Energy (OSTI)

A series of maps is presented, depicting the heat flow within the conterminous United States based on all data available to the U.S. Geological Survey (USGS) as of August 1976. Sources include all published data and about a hundred new USGS values currently being readied for publication. Tables are included on locations, heat flow, and heat production for published values plotted on the maps. (JGB)

Sass, J.H.; Diment, W.H.; Lachenbruch, A.H.; Marshall, B.V.; Munroe, R.J.; Moses, T.H. Jr.; Urban, T.C.

1976-01-01T23:59:59.000Z

131

Numerical simulation of fluid flow and heat transfer in a water heater  

Science Conference Proceedings (OSTI)

Energy consumption represents a major concern, considering the limited resources and latest targets for lower emissions of carbon dioxide. Therefore design of electric heating elements for household and industry are more and more subject to optimization, ... Keywords: electric heating, finite elements, fluid flow, heat transfer

Mircea Nicoar?; Aurel R?du??; Lauren?iu Roland Cucuruz; Cosmin Locovei

2010-04-01T23:59:59.000Z

132

Comparison of the high temperature heat flux sensor to traditional heat flux gages under high heat flux conditions.  

SciTech Connect

Four types of heat flux gages (Gardon, Schmidt-Boelter, Directional Flame Temperature, and High Temperature Heat Flux Sensor) were assessed and compared under flux conditions ranging between 100-1000 kW/m2, such as those seen in hydrocarbon fire or propellant fire conditions. Short duration step and pulse boundary conditions were imposed using a six-panel cylindrical array of high-temperature tungsten lamps. Overall, agreement between all gages was acceptable for the pulse tests and also for the step tests. However, repeated tests with the HTHFS with relatively long durations at temperatures approaching 1000%C2%B0C showed a substantial decrease (10-25%) in heat flux subsequent to the initial test, likely due to the mounting technique. New HTHFS gages have been ordered to allow additional tests to determine the cause of the flux reduction.

Blanchat, Thomas K.; Hanks, Charles R.

2013-04-01T23:59:59.000Z

133

Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01  

SciTech Connect

The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m2). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that ~50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a "toe-thrust" ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those ~70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the KG basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m2. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basin is at the low end of glob

Trehu, Anne; Kannberg, Peter

2011-06-30T23:59:59.000Z

134

Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01  

Science Conference Proceedings (OSTI)

The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m{sup 2}). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that {approx}50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a 'toe-thrust' ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those {approx}70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the K-G basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m{sup 2}. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basi

Anne Trehu; Peter Kannberg

2011-06-30T23:59:59.000Z

135

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

grain-specific heat for each model grid layer, are providedand heat flow is simulated using the 3-D TH model grid (

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

136

Commercial high efficiency dehumidification systems using heat pipes  

SciTech Connect

An improved heat pipe design using separately connected two-section one-way flow heat pipes with internal microgrooves instead of wicks is described. This design is now commercially available for use to increase the dehumidification capacity of air conditioning systems. The design also includes a method of introducing fresh air into buildings while recovering heat and controlling the humidity of the incoming air. Included are applications and case studies, load calculations and technical data, and installation, operation, and maintenance information.

1993-09-01T23:59:59.000Z

137

Numerical models for high beta magnetohydrodynamic flow  

Science Conference Proceedings (OSTI)

The fundamentals of numerical magnetohydrodynamics for highly conducting, high-beta plasmas are outlined. The discussions emphasize the physical properties of the flow, and how elementary concepts in numerical analysis can be applied to the construction of finite difference approximations that capture these features. The linear and nonlinear stability of explicit and implicit differencing in time is examined, the origin and effect of numerical diffusion in the calculation of convective transport is described, and a technique for maintaining solenoidality in the magnetic field is developed. Many of the points are illustrated by numerical examples. The techniques described are applicable to the time-dependent, high-beta flows normally encountered in magnetically confined plasmas, plasma switches, and space and astrophysical plasmas. 40 refs.

Brackbill, J.U.

1987-01-01T23:59:59.000Z

138

Combined cycle electric power plant and a heat recovery steam generator having improved boiler feed pump flow control  

SciTech Connect

A combined cycle electric power plant is described that includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes an economizer tube and a high pressure evaporator tube and a boiler feed pump for directing the heat exchange fluid serially through the aforementioned tubes. A condenser is associated with the steam turbine for converting the spent steam into condensate water to be supplied to a deaerator for removing undesired air and for preliminarily heating the water condensate before being pumped to the economizer tube. Condensate flow through the economizer tube is maintained substantially constant by maintaining the boiler feed pump at a predetermined, substantially constant rate. A bypass conduit is provided to feed back a portion of the flow heated in the economizer tube to the deaerator; the portion being equal to the difference between the constant flow through the economizer tube and the flow to be directed through the high pressure evaporator tube as required by the steam turbine for its present load.

Martz, L.F.; Plotnick, R.J.

1976-06-29T23:59:59.000Z

139

Phase change based cooling for high burst mode heat loads with temperature regulation above the phase change temperature  

DOE Patents (OSTI)

An apparatus and method for transferring thermal energy from a heat load is disclosed. In particular, use of a phase change material and specific flow designs enables cooling with temperature regulation well above the fusion temperature of the phase change material for medium and high heat loads from devices operated intermittently (in burst mode). Exemplary heat loads include burst mode lasers and laser diodes, flight avionics, and high power space instruments. Thermal energy is transferred from the heat load to liquid phase change material from a phase change material reservoir. The liquid phase change material is split into two flows. Thermal energy is transferred from the first flow via a phase change material heat sink. The second flow bypasses the phase change material heat sink and joins with liquid phase change material exiting from the phase change material heat sink. The combined liquid phase change material is returned to the liquid phase change material reservoir. The ratio of bypass flow to flow into the phase change material heat sink can be varied to adjust the temperature of the liquid phase change material returned to the liquid phase change material reservoir. Varying the flowrate and temperature of the liquid phase change material presented to the heat load determines the magnitude of thermal energy transferred from the heat load.

The United States of America as represented by the United States Department of Energy (Washington, DC)

2009-12-15T23:59:59.000Z

140

Heat transfer characteristics of R410A-oil mixture flow boiling inside a 7 mm straight smooth tube  

SciTech Connect

Two-phase flow patterns and heat transfer characteristics of R410A-oil mixture flow boiling inside a straight smooth tube with the outside diameter of 7.0 mm were investigated experimentally. The experimental conditions include the evaporation temperature of 5 C, the mass flux from 200 to 400 kg m{sup -2} s{sup -1}, the heat flux from 7.56 to 15.12 kW m{sup -2}, the inlet vapor quality from 0.2 to 0.7, nominal oil concentration from 0% to 5%. The test results show that the heat transfer coefficient of R410A-oil mixture increases with mass flux of refrigerant-oil mixture; the presence of oil enhances the heat transfer at the range of low and intermediate vapor qualities; there is a peak of local heat transfer coefficient at about 2-4% nominal oil concentration at higher vapor qualities, and the peak shifts to lower nominal oil concentration with the increasing of vapor qualities; higher nominal oil concentration gives more detrimental effect at high vapor qualities. The flow pattern map of R410A-oil mixture was developed based on refrigerant-oil mixture properties, and the observed flow patterns match well with the flow pattern map. New correlation to predict the local heat transfer of R410A-oil mixture flow boiling inside the straight smooth tube was developed based on flow patterns and local properties of refrigerant-oil mixture, and it agrees with 90% of the experiment data within the deviation of {+-}25%. (author)

Hu, Haitao; Ding, Guoliang; Wei, Wenjian; Wang, Zhence [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Wang, Kaijian [Fujitsu General Institute of Air-Conditioning Technology Limited, Kawasaki 213-8502 (Japan)

2008-01-15T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Heat transfer and pressure drop data for high heat flux densities to water at high subcritical pressures  

E-Print Network (OSTI)

Local surface ooeffioients of heat t-ansfer, overall pressure drop data and mean friction factor are presented for heat flamms up to 3.52106 BtuAr ft2 for water flowing in a nickel tabe isder the following conditions: mass ...

Rohsenow, Warren M.

1951-01-01T23:59:59.000Z

142

Flow and heat transfer in a curved pipe with periodically varying curvature  

SciTech Connect

A numerical analysis is carried out for the study of the flow and heat transfer for a laminar flow in a pipe with periodically varying finite (not very small) curvature. The effects of the flow rate (Re), the Prandtl number (Pr), the pipe-period ({kappa}) and the pipe-amplitude (a) on the heat transfer ratio (heat transfer of curved pipe to straight pipe) are studied. The results show that an increase in the amplitude and/or a decrease in the wavelength of a periodic wavy pipe can enhance the heat transfer rate significantly. The ratio of the heat transfer ratio to the friction ratio is greater than one which means a net benefit of heat transfer enhancement.

Yang, R.; Chang, S.F.; Wu, W.

2000-01-01T23:59:59.000Z

143

Cooling by Heat Conduction Inside Magnetic Flux Loops and the Moderate Cluster Cooling Flow Model  

E-Print Network (OSTI)

I study non-radiative cooling of X-ray emitting gas via heat conduction along magnetic field lines inside magnetic flux loops in cooling flow clusters of galaxies. I find that such heat conduction can reduce the fraction of energy radiated in the X-ray band by a factor of 1.5-2. This non-radiative cooling joins two other proposed non-radiative cooling processes, which can be more efficient. These are mixing of cold and hot gas, and heat conduction initiated by magnetic fields reconnection between hot and cold gas. These processes when incorporated into the moderate cooling flow model lead to a general cooling flow model with the following ingredients. (1) Cooling flow does occur, but with a mass cooling rate about 10 times lower than in old versions of the cooling flow model. Namely, heating occurs such that the effective age of the cooling flow is much below the cluster age, but the heating can't prevent cooling altogether. (2) The cooling flow region is in a non-steady state evolution. (3) Non-radiative cooling of X-ray emitting gas can bring the model to a much better agreement with observations. (4) The general behavior of the cooling flow gas, and in particular the role played by magnetic fields, make the intracluster medium in cooling flow clusters similar in some aspects to the active solar corona.

Noam Soker

2003-11-02T23:59:59.000Z

144

A low NO/sub x/ combustion system and a ceramic cross flow heat exchanger for small gas turbines  

SciTech Connect

A new low NO/sub x/ oil-combustion system with superheated steam fuel evaporation prior to combustion has been found especially feasible for open cycle gas turbines with high turbine inlet temperatures and ceramic cross flow heat exchanger. The actual state of development of both the low NO/sub x/ light fuel-oil combustion system and ceramic heat exchanger elements, especially the cross flow type, is outlined in this paper. The use of this combustion system results in considerably lower combustion temperatures in the primary combustion zone, reducing the NO/sub x/-production even at high air temperatures when the air is preheated in the heat exchanger. The water vapour used for the evaporation of the fuel oil before combustion has an improving effect on the cycle efficiency comparable to the Cheng-dual-fluid-cycle. Illustrative evaluations for a gas turbine cycle for a shaft power of 70 kW are given.

Forster, S.; Quell, P.

1987-01-01T23:59:59.000Z

145

Laclede Gas Company - Residential High Efficiency Heating Rebate Program |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Residential High Efficiency Heating Rebate Residential High Efficiency Heating Rebate Program Laclede Gas Company - Residential High Efficiency Heating Rebate Program < Back Eligibility Multi-Family Residential Residential Savings Category Heating & Cooling Commercial Heating & Cooling Heating Appliances & Electronics Water Heating Maximum Rebate Heating System: 2 maximum Programmable Thermostats: 2 maximum Multi-Family Property Owners: 50 thermostat rebates, 50 furnace rebates over the life of the program Program Info State Missouri Program Type Utility Rebate Program Rebate Amount Gas Furnace: $150 - $200 Gas Boiler: $150 Programmable Setback Thermostat: $25 Gas Water Heater: $50 - $200 Provider Laclede Gas Company Laclede Gas Company offers various rebates to residential customers for investing in energy efficient equipment and appliances. Residential

146

Two-phase gas-liquid flow characteristics inside a plate heat exchanger  

Science Conference Proceedings (OSTI)

In the present study, the air-water two-phase flow characteristics including flow pattern and pressure drop inside a plate heat exchanger are experimentally investigated. A plate heat exchanger with single pass under the condition of counter flow is operated for the experiment. Three stainless steel commercial plates with a corrugated sinusoidal shape of unsymmetrical chevron angles of 55 and 10 are utilized for the pressure drop measurement. A transparent plate having the same configuration as the stainless steel plates is cast and used as a cover plate in order to observe the flow pattern inside the plate heat exchanger. The air-water mixture flow which is used as a cold stream is tested in vertical downward and upward flow. The results from the present experiment show that the annular-liquid bridge flow pattern appeared in both upward and downward flows. However, the bubbly flow pattern and the slug flow pattern are only found in upward flow and downward flow, respectively. The variation of the water and air velocity has a significant effect on the two-phase pressure drop. Based on the present data, a two-phase multiplier correlation is proposed for practical application. (author)

Nilpueng, Kitti [Department of Mechanical Engineering, South East Asia University, Bangkok 10160 (Thailand); Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

2010-11-15T23:59:59.000Z

147

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.fluid flow, mass transport, and heat-transfer processes through porous and fractured media.

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

148

Variational formulations for resting irreversible fluids with heat flow  

Science Conference Proceedings (OSTI)

Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave model of heat: relaxation ... Keywords: conservation laws, entropy, grad solution, variational calculus, wave equations

Stanislaw Sieniutycz; Piotr Kuran

2008-09-01T23:59:59.000Z

149

Perturbations in high-velocity gas flow  

DOE Green Energy (OSTI)

High velocity explosive products or other low-density gases are often used to accelerate metal plates to high velocities. Perturbations in otherwise uniform flow configurations are sometimes sufficient to cause interactions that can rapidly destroy the integrity of the plates. In this study perturbations were introduced in uniform gas flows of detonated HE products and strongly shocked polyethylene, CH{sub 2}. The primary diagnostics were smear-camera records obtained when these gases impinged on layers of plexiglas separated by small argon-filled gaps. These records show shock-arrival times at various levels and thus determine not only the size of the perturbation but also its strength. Perturbations in HE gases running into H{sub 2} and in CH{sub 2} into H{sub 2} have been studied. Two-dimensional hydrodynamic calculations are in excellent agreement with the experiments, and enable one to study details of the flow not possible from experimental results. 1 ref., 5 figs.

Harvey, W.B.; McQueen, R.G. (Los Alamos National Lab., NM (USA))

1989-01-01T23:59:59.000Z

150

Flow and heat transfer due to a buoyant ceiling jet turning downward at a corner  

Science Conference Proceedings (OSTI)

An experimental investigation has been carried out on the flow and heat transfer characteristics of a horizontal buoyant ceiling jet that turns downward at a corner to yield a vertical negatively buoyant wall flow. In this study, a two-dimensional jet of heated air is discharged adjacent to the lower surface of an isothermal horizontal plate. An isothermal vertical plate is attached at the other end of the horizontal surface, making a right angle corner. The vertical penetration distance of the resulting downward flow is measured and is related to the inflow conditions, particularly to the temperature and velocity at the jet discharge. This penetration distance is found to increase as the distance between the discharge location and the corner is reduced and also as the relative buoyancy level in the inlet flow is decreased. Velocity and temperature measurements are also carried out over the flow region. These indicate that the ceiling flow separates from the horizontal surface just before reaching the corner and then reattaches itself to the vertical wall at a finite distance vertically below the corner. The local surface heat flux measurements show a minimum in the heat transfer rate before the turn, along with a recovery in the heat transfer rate after the turn and the existence of a small recirculation zone near the corner. The net entrainment into the flow and heat transfer rate to the solid boundaries are also measured and correlated with the jet discharge conditions. 22 refs., 12 figs., 1 tab.

Kapoor, K.; Jaluria, Y. [Rutgers - State Univ. of New Jersey, New Brunswick, NJ (United States)

1996-02-01T23:59:59.000Z

151

Application of heat-flow techniques to geothermal energy exploration, Leach Hot Springs area, Grass Valley, Nevada  

DOE Green Energy (OSTI)

A total of 82 holes ranging in depth from 18 to 400 meters were drilled for thermal and hydrologic studies in a 200 km/sup 2/ area of Grass Valley, Nevada, near Leach Hot Springs. Outside the immediate area of Leach Hot Springs, heat flow ranges from 1 to 6.5 hfu with a mean of 2.4 hfu (1 hfu = 10/sup -6/ cal cm/sup 2/ s/sup -1/ = 41.8 mWm/sup -2/). Within 2 km of the springs, conductive heat flow ranges between 1.6 and more than 70 hfu averaging 13.6 hfu. Besides the conspicuous thermal anomaly associated with the hot springs, two additional anomalies were identified. One is associated with faults bounding the western margin of the Tobin Range near Panther Canyon, and the other is near the middle of Grass Valley about 5 km SSW of Leach Hot Springs. The mid-valley anomaly appears to be caused by hydrothermal circulation in a bedrock horst beneath about 375 meters of impermeable valley sediments. If the convective and conductive heat discharge within 2 km of the Leach Hot Springs is averaged over the entire hydrologic system (including areas of recharge), the combined heat flux from this part of Grass Valley is about 3 hfu, consistent with the average regional conductive heat flow in the Battle Mountain High. The hydrothermal system can be interpreted as being in a stationary stable phase sustained by high regional heat flow, and no localized crustal heat sources (other than hydrothermal convection to depths of a few kilometers) need be invoked to explain the existence of Leach Hot Springs.

Sass, J.H.; Ziagos, J.P.; Wollenberg, H.A.; Munroe, R.J.; di Somma, D.E.; Lachenbruch, A.H.

1977-01-01T23:59:59.000Z

152

The simplicity of fractal-like flow networks for effective heat and mass transport  

SciTech Connect

A variety of applications using disk-shaped fractal-like flow networks and the status of one and two-dimensional predictive models for these applications are summarized. Applications discussed include single-phase and two-phase heat sinks and heat exchangers, two-phase flow separators, desorbers, and passive micromixers. Advantages of using these fractal-like flow networks versus parallel-flow networks include lower pressure drop, lower maximum wall temperature, inlet plenum symmetry, alternate flow paths, and pressure recovery at the bifurcation. The compact nature of microscale fractal-like branching heat exchangers makes them ideal for modularity. Differences between fractal-like and constructal approaches applied to disk-shaped heat sink designs are highlighted, and the importance of including geometric constraints, including fabrication constraints, in flow network design optimization is discussed. Finally, a simple pencil and paper procedure for designing single-phase heat sinks with fractal-like flow networks based solely on geometric constraints is outlined. Benefit-to-cost ratios resulting from geometric-based designs are compared with those from flow networks determined using multivariable optimization. Results from the two network designs are within 11%. (author)

Pence, Deborah [Oregon State University, Mechanical Engineering, 204 Rogers Hall, Corvallis, Oregon 97331-6001 (United States)

2010-05-15T23:59:59.000Z

153

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. (Los Alamos National Lab., NM (United States)); Critchley, E. (Phillips Lab., Kirtland AFB, NM (United States))

1993-01-01T23:59:59.000Z

154

High temperature heat pipe experiments in low earth orbit  

SciTech Connect

Although high temperature, liquid metal heat pipe radiators have become a standard component on most high power space power system designs, there is no experimental data on the operation of these heat pipes in a zero gravity or micro-gravity environment. Experiments to benchmark the transient and steady state performance of prototypical heat pipe space radiator elements are in preparation for testing in low earth orbit. It is anticipated that these heat pipes will be tested aborad the Space Shuttle in 1995. Three heat pipes will be tested in a cargo bay Get Away Special (GAS) canister. The heat pipes are SST/potassium, each with a different wick structure; homogeneous, arterial, and annular gap, the heat pipes have been designed, fabricated, and ground tested. In this paper, the heat pipe designs are specified, and transient and steady-state ground test data are presented.

Woloshun, K.; Merrigan, M.A.; Sena, J.T. [Los Alamos National Lab., NM (United States); Critchley, E. [Phillips Lab., Kirtland AFB, NM (United States)

1993-02-01T23:59:59.000Z

155

Temperatures, heat flow, and water chemistry from drill holes in the Raft  

Open Energy Info (EERE)

Temperatures, heat flow, and water chemistry from drill holes in the Raft Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Report: Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Details Activities (1) Areas (1) Regions (0) Abstract: The Raft River area of Idaho contains a geothermal system of intermediate temperatures (approx. = 150 0C) at depths of about 1.5 km. Outside of the geothermal area, temperature measurements in three intermediate-depth drill holes (200 to 400 m) and one deep well (1500 m) indicate that the regional conductive heat flow is about 2.5 mucal/cm 2 sec or slightly higher and that temperature gradients range from 50 0 to 60

156

Analysis of Chemically Reacting Gas Flow and Heat Transfer in Methane Reforming Processes  

Science Conference Proceedings (OSTI)

This paper presents simulation and analysis of gas flow and heat transfer affected by chemical reactions relating to steam reforming of methane in a compact reformer. The reformer conditions such as the combined thermal boundary conditions on solid walls, ...

Guogang Yang; Danting Yue; Xinrong Lv; Jinliang Yuan

2009-10-01T23:59:59.000Z

157

Three-Dimensional Response of a Shear Flow to Elevated Heating  

Science Conference Proceedings (OSTI)

The three-dimensional response of a shear flow to elevated heating is investigated using linear theory. The basic wind profile is allowed to reverse directions at a certain height. Effects of shear, evaporative cooling, and the stratosphere are ...

Yuh-Lang Lin; Shiaolin Li

1988-10-01T23:59:59.000Z

158

Heat and Momentum Fluxes Induced by Thermal Inhomogeneities with and without Large-Scale Flow  

Science Conference Proceedings (OSTI)

The authors Present an analytical evaluation of the vertical heat and momentum fluxes associated with mesoscale flow generated by periodic and isolated thermal inhomogeneities within the convective boundary layer (CBL). The influence of larger-...

G. A. Dalu; R. A. Pielke; M. Baldi; X. Zeng

1996-11-01T23:59:59.000Z

159

A Blow-up Criterion for Two Dimensional Compressible Viscous Heat-Conductive Flows  

E-Print Network (OSTI)

We establish a blow-up criterion in terms of the upper bound of the density and temperature for the strong solution to 2D compressible viscous heat-conductive flows. The initial vacuum is allowed.

Fang, Daoyuan; Zhang, Ting

2011-01-01T23:59:59.000Z

160

Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling...  

NLE Websites -- All DOE Office Websites (Extended Search)

Reynolds Number (Nu Nu o ) (f f o ) 24% Increase in Cooling Performance Rotating Heat Transfer in High Aspect Ratio Rectangular Cooling Passages with Shaped Turbulators...

Note: This page contains sample records for the topic "high heat flow" from the National Library of EnergyBeta (NLEBeta).
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161

Creep Behavior of High Temperature Alloys for Intermediate Heat ...  

Science Conference Proceedings (OSTI)

Presentation Title, Creep Behavior of High Temperature Alloys for Intermediate Heat Exchanger in Next Generation Nuclear Plant. Author(s), Xingshuo Wen, ...

162

Saturated critical heat flux in a multi-microchannel heat sink fed by a split flow system  

SciTech Connect

An extensive experimental campaign has been carried out for the measurement of saturated critical heat flux in a multi-microchannel copper heat sink. The heat sink was formed by 29 parallel channels that were 199 {mu}m wide and 756 {mu}m deep. In order to increase the critical heat flux and reduce the two-phase pressure drop, a split flow system was implemented with one central inlet at the middle of the channels and two outlets at either end. The base critical heat flux was measured using three HFC Refrigerants (R134a, R236fa and R245fa) for mass fluxes ranging from 250 to 1500 kg/m{sup 2} s, inlet subcoolings from -25 to -5 K and saturation temperatures from 20 to 50 C. The parametric effects of mass velocity, saturation temperature and inlet subcooling were investigated. The analysis showed that significantly higher CHF was obtainable with the split flow system (one inlet-two outlets) compared to the single inlet-single outlet system, providing also a much lower pressure drop. Notably several existing predictive methods matched the experimental data quite well and quantitatively predicted the benefit of higher CHF of the split flow. (author)

Mauro, A.W.; Toto, D. [Department of Energetics, Applied Thermofluidynamics and Air Conditioning Systems, FEDERICO II University, p.le Tecchio 80, 80125 Napoli (Italy); Thome, J.R. [Laboratory of Heat and Mass Transfer (LTCM), Faculty of Engineering (STI), Ecole Polytechnique Federale de Lausanne (EPFL), Station 9, Lausanne CH-1015 (Switzerland); Vanoli, G.P. [Engineering Department, Sannio University, Corso Garibaldi 107, Palazzo dell'Aquila Bosco Lucarelli, 82100 Benevento (Italy)

2010-01-15T23:59:59.000Z

163

Heat transfer and pressure drop for air flow through enhanced passages. Final report  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

164

Heat transfer and pressure drop for air flow through enhanced passages  

SciTech Connect

An extensive experimental investigation was carried out to determine the pressure drop and heat transfer characteristics for laminar, transitional and turbulent flow of air through a smooth passage and twenty-three enhanced passages. The internal surfaces of all enhanced passages had spirally shaped geometries; these included fluted, finned/ribbed and indented surfaces. The Reynolds number (Re) was varied between 400 and 50000. The effect of heat transfer (wall cooling or fluid heating) on pressure drop is most significant within the transition region; the recorded pressure drop with heat transfer is much higher than that without heat transfer. The magnitude of this effect depends markedly on the average surface temperature and, to a lesser extent, on the geometric characteristics of the enhanced surfaces. When the pressure drop data are reduced as values of the Fanning friction factor(f), the results are about the same with and without heat transfer for turbulent flow, with moderate differences in the laminar and transition regions.

Obot, N.T.; Esen, E.B.

1992-06-01T23:59:59.000Z

165

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki  

E-Print Network (OSTI)

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki Department of Physics as a functional of the order parameter and the energy density. Let us consider one-component fluids, where-component fluids the effect is drastically altered due to latent heat generation or absorption at the interface [12

166

Natural convection flow over an inclined flat plate with internal heat generation and variable viscosity  

Science Conference Proceedings (OSTI)

The present investigation deals with study of laminar natural convection flow of a viscous fluid over a semi-infinite flat plate inclined at a small angle to the horizontal with internal heat generation and variable viscosity. The dimensionless boundary ... Keywords: Heat generation, Inclined flat surface, Natural convection, Temperature dependent viscosity

S. Siddiqa; S. Asghar; M. A. Hossain

2010-11-01T23:59:59.000Z

167

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology  

DOE Green Energy (OSTI)

Precise airborne temperature surveys depicted small predawn surface temperature differences related to heat flow anomalies at the Long Valley, California, KGRA. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) has predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. The warmer zones had hot water circulating in a shallow (less than 60-m-deep) aquifer. Hot water is a useful geochemical indicator of geothermal and mineral resource potential. The precise airborne temperature survey method recorded redundant infrared scanner signals at two wavelengths (10 to 12 ..mu..m and 4.5 to 5.5 ..mu..m) and two elevations (0.3 km and 1.2 km). Ground thermistor probes recorded air and soil temperatures during the survey overflights. Radiometric temperatures were corrected for air-path and reflected-sky-radiation effects. Corrected temperatures were displayed in image form with color-coded maps which depicted 0.24/sup 0/C temperature differences. After accounting for surficial features on the corrected predawn thermal imagery, there remained several anomalous zones. These zones had high temperature gradients at depths from 6 to 30 m, compared to the temperature gradients in nearby areas.

Del Grande, N.K.

1982-11-10T23:59:59.000Z

168

Variable Refrigerant Flow Air Conditioners and Heat Pumps for Commercial Buildings  

Science Conference Proceedings (OSTI)

Multi-split heat pumps have evolved from a technology suitable for residential and light commercial buildings to variable refrigerant flow (VRF) systems that can provide efficient space conditioning for large commercial buildings. VRF systems are enhanced versions of ductless multi-split systems, permitting more indoor units to be connected to each outdoor unit and providing additional features such as simultaneous heating and cooling and heat recovery. VRF systems are very popular in Asia and Europe and...

2008-01-25T23:59:59.000Z

169

Coupled Model for Heat and Water Transport in a High Level Waste Repository  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coupled Model for Heat and Water Transport in a High Level Waste Coupled Model for Heat and Water Transport in a High Level Waste Repository in Salt Coupled Model for Heat and Water Transport in a High Level Waste Repository in Salt This report summarizes efforts to simulate coupled thermal-hydrological-chemical (THC) processes occurring within a generic hypothetical high-level waste (HLW) repository in bedded salt; chemical processes of the system allow precipitation and dissolution of salt with elevated temperatures that drive water and water vapor flow around hot waste packages. Characterizing salt backfill processes is an important objective of the exercise. An evidence-based algorithm for mineral dehydration is also applied in the modeling. The Finite Element Heat and Mass transfer code (FEHM) is used to simulate coupled thermal,

170

Anomalous recovery of damped radial modes in a circular?sector duct with locally heated flow  

Science Conference Proceedings (OSTI)

It is often desirable to predict acoustic propagation in a circular duct carrying a locally heated flow. Common examples include jet engines and certain industrial and commercial burners whose combustion?related noise can be an environmental problem if allowed to penetrate into the surroundings. In these cases axial gradients in the steady flow variables

J. R. Maham; S.?Y. Yeh

1984-01-01T23:59:59.000Z

171

Implicitly balanced solution of the two-phase flow equations coupled to nonlinear heat conduction  

Science Conference Proceedings (OSTI)

This paper presents the solution of the two-phase flow equations coupled to nonlinear heat conduction using the Jacobian-free Newton-Krylov (JFNK) method which employs a physics-based preconditioner. Computer simulations will demonstrate that the implicitly ... Keywords: implicit, nonlinear, preconditioning, two-phase flow

V. A. Mousseau

2004-10-01T23:59:59.000Z

172

Numerical Investigation of Heat Transfer to Fully Developed Turbulent Air Flow in a Concentric Pipe  

Science Conference Proceedings (OSTI)

Numerical simulation using standard k-e turbulencemodel was developed to investigate numerically thecharacteristic of backward-facing step flow in a concentricpipe. This research is focused on the surface temperature, localheat transfer coefficient and ... Keywords: Numerical Simulation, Heat Transfer, Turbulent Flow, Computational Fluid Dynamics, Backward Facing Step

Cheen Sean Oon, Ahmad Badarudin, Salim Newaz Kazi, Arif Syazwan

2013-09-01T23:59:59.000Z

173

Investigation of the Heat Transfer Coefficient of Liquid and Gas Bubble Train Flow in a Square Mini-channel Using Infra-Red thermography  

E-Print Network (OSTI)

Investigation of the Heat Transfer Coefficient of Liquid and Gas Bubble Train Flow in a Square Mini slug and bubbles, liquid and gas superficial velocities which depend on the volume flow ratio of the channel (Bo) for specific liquid and gas phase. At relatively high Bo (Bo>Bocr1.835) systems gravity force

Khandekar, Sameer

174

Oscillating flow loss test results in Stirling engine heat exchangers. Final Report  

SciTech Connect

The results are presented for a test program designed to generate a database of oscillating flow loss information that is applicable to Stirling engine heat exchangers. The tests were performed on heater/cooler tubes of various lengths and entrance/exit configurations, on stacked and sintered screen regenerators of various wire diameters and on Brunswick and Metex random fiber regenerators. The test results were performed over a range of oscillating flow parameters consistent with Stirling engine heat exchanger experience. The tests were performed on the Sunpower oscillating flow loss rig which is based on a variable stroke and variable frequency linear drive motor. In general, the results are presented by comparing the measured oscillating flow losses to the calculated flow losses. The calculated losses are based on the cycle integration of steady flow friction factors and entrance/exit loss coefficients.

Koester, G.; Howell, S.; Wood, G.; Miller, E.; Gedeon, D.

1990-05-01T23:59:59.000Z

175

Technical Subtopic 2.1: Modeling Variable Refrigerant Flow Heat Pump and Heat Recovery Equipment in EnergyPlus  

Science Conference Proceedings (OSTI)

The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow heat pump (VRF HP) manufacturers, provided a detailed computer model for a VRF HP system in the United States Department of Energy's (U.S. DOE) EnergyPlus? building energy simulation tool. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance to both the manufacturer's data and that predicted by the use of this new model through computer simulation. The project goal was to investigate the complex interactions of VRF HP systems from an HVAC system perspective, and explore the operational characteristics of this HVAC system type within a laboratory and real world building environment. Detailed laboratory testing of this advanced HVAC system provided invaluable performance information which does not currently exist in the form required for proper analysis and modeling. This information will also be useful for developing and/or supporting test standards for VRF HP systems. Field testing VRF HP systems also provided performance and operational information pertaining to installation, system configuration, and operational controls. Information collected from both laboratory and field tests were then used to create and validate the VRF HP system computer model which, in turn, provides architects, engineers, and building owners the confidence necessary to accurately and reliably perform building energy simulations. This new VRF HP model is available in the current public release version of DOE?s EnergyPlus software and can be used to investigate building energy use in both new and existing building stock. The general laboratory testing did not use the AHRI Standard 1230 test procedure and instead used an approach designed to measure the field installed full-load operating performance. This projects test methodology used the air enthalpy method where relevant air-side parameters were controlled while collecting output performance data at discreet points of steady-state operation. The primary metrics include system power consumption and zonal heating and cooling capacity. Using this test method, the measured total cooling capacity was somewhat lower than reported by the manufacturer. The measured power was found to be equal to or greater than the manufacturers indicated power. Heating capacity measurements produced similar results. The air-side performance metric was total cooling and heating energy since the computer model uses those same metrics as input to the model. Although the sensible and latent components of total cooling were measured, they are not described in this report. The test methodology set the thermostat set point temperature very low for cooling and very high for heating to measure full-load performance and was originally thought to provide the maximum available capacity. Manufacturers stated that this test method would not accurately measure performance of VRF systems which is now believed to be a true statement. Near the end of the project, an alternate test method was developed to better represent VRF system performance as if field installed. This method of test is preliminarily called the Load Based Method of Test where the load is fixed and the indoor conditions and unit operation are allowed to fluctuate. This test method was only briefly attempted in a laboratory setting but does show promise for future lab testing. Since variable-speed air-conditioners and heat pumps include an on-board control algorithm to modulate capacity, these systems are difficult to test. Manufacturers do have the ability to override internal components to accommodate certification procedures, however, it is unknown if the resulting operation is replicated in the field, or if so, how often. Other studies have shown that variable-speed air-conditioners and heat pumps do out perform their single-speed counterparts though these field studies leave as many questions as they do provide answers. The measure

Raustad, Richard; Nigusse, Bereket; Domitrovic, Ron

2013-09-30T23:59:59.000Z

176

Problems in suppressing cooling flows in clusters of galaxies by global heat conduction  

E-Print Network (OSTI)

I use a simple analytical model to show that simple heat conduction models cannot significantly suppress cluster cooling flows. I build a static medium where heat conduction globally balances radiative cooling, and then perturb it. I show that a perturbation extending over a large fraction of the cooling flow region will grow to the non-linear regime within a Hubble time. Such perturbations are reasonable in clusters which frequently experience mergers and/or AGN activity. This result strengthens previous findings which show that a steady solution does not exist for a constant heat conduction coefficient.

Noam Soker

2003-02-19T23:59:59.000Z

177

Coevolution of inverse cascade and nonlinear heat front in shear flows of strongly coupled Yukawa liquids  

Science Conference Proceedings (OSTI)

Using classical molecular dynamics (MD) simulations, we report on the development and propagation of a nonlinear heat front in parallel shear flows of a strongly coupled Yukawa liquid. At a given coupling strength, a subsonic shear profile is superposed on an equilibrated Yukawa liquid and Kelvin Helmholtz (KH) instability is observed. Coherent vortices are seen to emerge towards the nonlinear regime of the instability. It is seen that while inverse cascade leads to a continuous transfer of flow energy towards the largest scales, there is also a simultaneous transfer of flow energy into the thermal velocities of grains at the smallest scale. The latter is an effect of velocity shear and thus leads to the generation of a nonlinear heat front. In the linear regime, the heat front is seen to propagate at speed much lesser than the adiabatic sound speed of the liquid. Spatio-temporal growth of this heat front occurs concurrently with the inverse cascade of KH modes.

Ashwin, J.; Ganesh, R. [Institute for Plasma Research, Bhat, Gandhinagar 382428, Gujarat (India)

2011-08-15T23:59:59.000Z

178

A heat exchanger between forced flow helium gas at 14 to 18 K and liquid hydrogen at 20 K circulated by natural convection  

E-Print Network (OSTI)

LBNL-53719 A HEAT EXCHANGER BETWEEN FORCED FLOW HELIUM GAShydrogen absorber and the heat exchanger between the liquidpasses through the heat exchanger in the absorber shell. The

Green, M.A.; Ishimoto, S.; Lau, W.; Yang, S.

2003-01-01T23:59:59.000Z

179

Heat transfer characteristics of circular impinging jet arrays in an annular section with cross flow effects  

E-Print Network (OSTI)

Jet impingement has been shown to be an effective method for enhancing convective heat transfer. There are a variety of applications of impinging jets in industry, including tempering and shaping of glass, annealing of metal and plastic sheets, cooling of electronic components and drying of paper, veneer, etc. Another application is the use of impinging jets in internal cooling channels in modern gas turbine blades. High velocity jets provide an effective way to augment the rate of heat removal from the blades to the cooling air, maintaining the blade temperatures within tolerable and metallurgical limits. This experimental research examines, for turbulent parallel and counter flows of air through an annular channel with holes for jet impingement along the inner tube, the effects of varying the geometries of the channel and the hole array, and the air flow rate, on the heat transfer distribution on the inner surfaces of the outer tube. Air enters one end of the inner tube, whose other end is closed, passes through the holes on the inner tube and exits through one end of the annular passage between the inner and outer tubes. Each hole array has inline or staggered circular holes with a given diameter and has a fixed number of holes around the circumference of the inner tube at any cross section of the annular channel. Heat transfer experiments are performed for Reynolds numbers of 5,000, 12,250 and 30,000 to determine the distribution of the regionally average Nusselt numbers along the outer tube, as a result of the impinging jets along the inner tube. Pressure measurement experiments give the pressure distributions in the airflows in the inner tube and between the inner and outer tubes. The pressure data is needed to determine the mass flow rates of the impinging jets along the inner tube. The results of the experiments are presented and discussed, the Nusselt numbers for the various cases studied are compared and major findings are reported. The results of this investigation should be particularly useful to engineers in the design of the leading edges of airfoils of modern gas turbine blades.

Mhetras, Shantanu Prakash

2002-01-01T23:59:59.000Z

180

Heat transfer and fluid dynamics of air-water two-phase flow in micro-channels  

SciTech Connect

Heat transfer, pressure drop, and void fraction were simultaneously measured for upward heated air-water non-boiling two-phase flow in 0.51 mm ID tube to investigate thermo-hydro dynamic characteristics of two-phase flow in micro-channels. At low liquid superficial velocity j{sub l} frictional pressure drop agreed with Mishima-Hibiki's correlation, whereas agreed with Chisholm-Laird's correlation at relatively high j{sub l}. Void fraction was lower than the homogeneous model and conventional empirical correlations. To interpret the decrease of void fraction with decrease of tube diameter, a relation among the void fraction, pressure gradient and tube diameter was derived. Heat transfer coefficient fairly agreed with the data for 1.03 and 2.01 mm ID tubes when j{sub l} was relatively high. But it became lower than that for larger diameter tubes when j{sub l} was low. Analogy between heat transfer and frictional pressure drop was proved to hold roughly for the two-phase flow in micro-channel. But satisfactory relation was not obtained under the condition of low liquid superficial velocity. (author)

Kaji, Masuo; Sawai, Toru; Kagi, Yosuke [Department of Mechanical Engineering, School of Biology-Oriented Science and Technology, Kinki University, 930 Nishi-mitani, Kinokawa, Wakayama 649-6493 (Japan); Ueda, Tadanobu [Toyota Central R and D Laboratory, Incorporated, 41-1 Yokomichi, Nagakute, Aichi 480-1192 (Japan)

2010-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Heat Budget of the Siberian High and the Winter Monsoon  

Science Conference Proceedings (OSTI)

The heat budget of the Siberian high is investigated by using a compositing method. Ninteen cases of strong Siberian highs that moved over China from the northwest were selected from datasets covering five winters (December through February of ...

Yihui Ding; T. N. Krishnamurti

1987-10-01T23:59:59.000Z

182

Emissivity corrected infrared method for imaging anomalous structural heat flows  

DOE Patents (OSTI)

A method for detecting flaws in structures using dual band infrared radiation is disclosed. Heat is applied to the structure being evaluated. The structure is scanned for two different wavelengths and data obtained in the form of images. Images are used to remove clutter to form a corrected image. The existence and nature of a flaw is determined by investigating a variety of features. 1 fig.

Del Grande, N.K.; Durbin, P.F.; Dolan, K.W.; Perkins, D.E.

1995-08-22T23:59:59.000Z

183

Counter flow cooling drier with integrated heat recovery  

DOE Patents (OSTI)

A drier apparatus for removing water or other liquids from various materials includes a mixer, drying chamber, separator and regenerator and a method for use of the apparatus. The material to be dried is mixed with a heated media to form a mixture which then passes through the chamber. While passing through the chamber, a comparatively cool fluid is passed counter current through the mixture so that the mixture becomes cooler and drier and the fluid becomes hotter and more saturated with moisture. The mixture is then separated into drier material and media. The media is transferred to the regenerator and heated therein by the hot fluid from the chamber and supplemental heat is supplied to bring the media to a preselected temperature for mixing with the incoming material to be dried. In a closed loop embodiment of the apparatus, the fluid is also recycled from the regenerator to the chamber and a chiller is utilized to reduce the temperature of the fluid to a preselected temperature and dew point temperature.

Shivvers, Steve D. (Prole, IA)

2009-08-18T23:59:59.000Z

184

THERMAL DESIGN METHODOLOGY FOR LOW FLOW RATE SINGLE-PHASE AND TWO-PHASE MICRO-CHANNEL HEAT SINKS  

E-Print Network (OSTI)

in Engine Cooling Systems,'' Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics 1997, June 1997, ``A Correlation for Boiling Heat Transfer to Saturated Fluids in Convective Flow,'' Ind. Eng. Chem the engines in automotive applications. Heat is transferred essentially under subcooled flow boiling

Qu, Weilin

185

Heat flow in the Oregon Cascade Range and its correlation with regional gravity, Curie point depths, and geology  

Science Conference Proceedings (OSTI)

Heat flow measurements from several deep wells (up to 2,500 m deep), as well as extensive new data from industry exploration efforts in the Breitenbush and the Santiam Pass-Belknap/Foley areas are described. The heat flow is about 100 mW m{sup {minus}2} in the High Cascade Range and at the eastern edge of the Western Cascade Range, and about 40-50 mW m{sup {minus}2} to the west in the outer arc block of the subduction zone. The gravity field in the Cascade Range has characteristics that can be closely related to the heat flow pattern. The relationship may be causal, and to examine the relationship in more detail, earlier two-dimensional modeling is extended to three dimensions. Consideration of the effects of a midcrustal density anomaly, such as might be associated with a region with at least areas of partial melt, as two major consequences. The first of these is that a high-frequency gravity gradient near the Western Cascade Range/High Cascade Range boundary is explained. Second, the negative gravity anomaly associated with the northeast/southwest striking regional Bouguer gravity anomaly associated with the north edge of the Blue Mountains becomes continuous across the Cascade Range with a similar feature along the north side of the Klamath Mountains. The correlation, or lack thereof, of the heat flow, depth to Curie point, gravity field, crustal electrical resistivity, crustal seismic velocity, and geology in the High/Western Cascade Ranges is summarized.

Blackwell, D.D.; Steele, J.L. (Southern Methodist Univ., Dallas, TX (USA)); Frohme, M.K. (Memphis State Univ., TN (USA)); Murphey, C.F. (Union Pacific Resources, Arlington, TX (USA)); Priest, G.R.; Black, G.L. (Dept. of Geological and Mineral Industries, Portland, OR (USA))

1990-11-10T23:59:59.000Z

186

Performance correlations for high temperature potassium heat pipes  

SciTech Connect

Potassium heat pipes designed for operation at a nominal temperature of 775K have been developed for use in a heat pipe cooled reactor design. The heat pipes operate in a gravity assist mode with a maximum required power throughput of approximately 16 kW per heat pipe. Based on a series of sub-scale experiments with 2.12 and 3.2 cm diameter heat pipes the prototypic heat pipe diameter was set at 5.7 cm with a simple knurled wall wick used in the interests of mechanical simplicity. The performance levels required for this design had been demonstrated in prior work with gutter assisted wicks and emphasis in the present work was on the attainment of similar performance with a simplified wick structure. The wick structure used in the experiment consisted of a pattern of knurled grooves in the internal wall of the heat pipe. The knurl depth required for the planned heat pipe performance was determined by scaling of wick characteristic data from the sub-scale tests. These tests indicated that the maximum performance limits of the test heat pipes did not follow normal entrainment limit predictions for textured wall gravity assist heat pipes. Test data was therefore scaled to the prototype design based on the assumption that the performance was controlled by an entrainment parameter based on the liquid flow depth in the groove structure. This correlation provided a reasonable fit to the sub-scale test data and was used in scale up of the design from the 8.0 cm/sup 2/ cross section of the largest sub-scale heat pipe to the 25.5 cm/sup 2/ cross section prototype. Correlation of the model predictions with test data from the prototype is discussed.

Merrigan, M.A.; Keddy, E.S.; Sena, J.T.

1987-01-01T23:59:59.000Z

187

New Heat Flow Models in Fractured Geothermal Reservoirs - Final Report  

DOE Green Energy (OSTI)

This study developed new analytical models for predicting the temperature distribution within a geothermal reservoir following reinjection of water having a temperature different from that of the reservoir. The study consisted of two parts: developing new analytical models for the heat conduction rate into multi-dimensional, parallelepiped matrix blocks and developing new analytical models for the advance of the thermal front through the geothermal reservoir. In the first part of the study, a number of semi-empirical models for the multi-dimensional heat conduction were developed to overcome the limitations to the exact solutions. The exact solution based on a similarity solution to the heat diffusion equation is the best model for the early-time period, but fails when thermal conduction fronts from opposing sides of the matrix block merge. The exact solution based on an infinite series solution was found not to be useful because it required tens of thousands of terms to be include d for accuracy. The best overall model for the entire conduction time was a semi-empirical model based on an exponential conduction rate. In the second part of the study, the early-time period exact solution based on similarity methods and the semi-empirical exponential model were used to develop new analytical models for the location of the thermal front within the reservoir during injection. These equations were based on an energy balance on the water in the fractured network. These convective models allowed for both dual and triple porosity reservoirs, i.e., one or two independent matrix domains. A method for incorporating measured fracture spacing distributions into these convective models was developed. It was found that there were only minor differences in the predicted areal extent of the heated zone between the dual and triple porosity models. Because of its simplicity, the dual porosity model is recommended. These new models can be used for preliminary reservoir studies. Although they are not as accurate as numerical simulators, they are simple, easy and inexpensive to use. These new models can be used to get general information about reservoir behavior before committing to the considerable greater expense of numerical simulation.

Reis, John

2001-03-31T23:59:59.000Z

188

Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders  

SciTech Connect

Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity of roughly 200 W/m-K and a CTE ranging from 7-12 ppm/ deg C, similar to that of silicon. An equivalent sized heat pipe embedded AlSiC plate has effective thermal conductivity ranging from 400 to 500 W/m-K and retains the CTE of AlSiC.

Johnson, Matthew (DOE/NNSA Kansas City Plant (United States)); Weyant, J.; Garner, S. (Advanced Cooling Technologies, Inc. (Lancaster, PA (United States)); Occhionero, M. (CPS Technologies Corporation, Norton, MA (United States))

2010-01-07T23:59:59.000Z

189

Electrically heated particulate filter with zoned exhaust flow control  

SciTech Connect

A system includes a particulate matter (PM) filter that includes X zones. An electrical heater includes Y heater segments that are associated with respective ones of the X zones. The electrical heater is arranged upstream from and proximate with the PM filter. A valve assembly includes Z sections that are associated with respective ones of the X zones. A control module adjusts flow through each of the Z sections during regeneration of the PM filter via control of the valve assembly. X, Y and Z are integers.

Gonze, Eugene V [Pinckney, MI

2012-06-26T23:59:59.000Z

190

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

SciTech Connect

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

191

High speed flow cytometric separation of viable cells  

SciTech Connect

Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

Sasaki, Dennis T. (Mountain View, CA); Van den Engh, Gerrit J. (Seattle, WA); Buckie, Anne-Marie (Margate, GB)

1995-01-01T23:59:59.000Z

192

High speed flow cytometric separation of viable cells  

DOE Patents (OSTI)

Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

Sasaki, D.T.; Van den Engh, G.J.; Buckie, A.M.

1995-11-14T23:59:59.000Z

193

Forced convection heat transfer in the transition region between laminar and turbulent flow for a vertical circular tube  

Science Conference Proceedings (OSTI)

In this study, first results of the heat transfer characteristic of a vertical double tube heat exchanger were determined. The heat exchanger was operated under cocurrent-flow conditions. The Reynolds-number was varied in the transition region between ... Keywords: circular tube, forced convection, heat transfer, transition region

D. Huber; H. Walter

2010-07-01T23:59:59.000Z

194

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

for both liquid and heat transfer processes. In order to beprocesses in hot fractured rock with ( 1) flow channeling in fractures, (2) interface reduction in F-M heat transfer,

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

195

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1  

Science Conference Proceedings (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

196

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2  

Science Conference Proceedings (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

197

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3  

SciTech Connect

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

198

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

Science Conference Proceedings (OSTI)

The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.

Moridis, G.J.; Pruess (editor), K.

1992-11-01T23:59:59.000Z

199

ON THE TRANSFER OF HEAT TO FLUIDS FLOWING THROUGH PIPES, ANNULI, AND PARALLEL PLATES  

SciTech Connect

Nusselt numbers were calculated for heat transfer to fluids flowing through annuli under conditions of uniform heat flux and fully established velocity and temperature profiles. The following cases were considered: (a) laminar flow, (b) slug flow, (c) turbulent flow with molecular conduction only, and (d) turbulent flow with both molecular and eddy conduction. These Nusselt numbers were determined for two conditions: heat transfer from the inner wall only and heat transfer from the outer wall only. The results were correlated by semi-empirical equations. The final results obtained on cases (a), (b), amd (c) are applicable to any fluid, whereas those obtained on (d) are for liquid metals only. Wall- and bulk-temperature relationships for the above four cases were also determined. These relationships were treated as dimensionless temperature ratios. Both the Nusselt numbers ad temperature ratios were evaluated over the r/ sub 1//r/sub 2/ range, zero to unity; the former being the case of the circular pipe, and the later, the case of infinite parallel plates. (auth)

Dwyer, O.E.

1963-01-01T23:59:59.000Z

200

Cedarville Elementary & High School Space Heating Low Temperature  

Open Energy Info (EERE)

Cedarville Elementary & High School Space Heating Low Temperature Cedarville Elementary & High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Cedarville Elementary & High School Space Heating Low Temperature Geothermal Facility Facility Cedarville Elementary & High School Sector Geothermal energy Type Space Heating Location Cedarville, California Coordinates 41.5290606°, -120.1732781° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

Note: This page contains sample records for the topic "high heat flow" 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

Cotulla High School Space Heating Low Temperature Geothermal Facility |  

Open Energy Info (EERE)

Cotulla High School Space Heating Low Temperature Geothermal Facility Cotulla High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Cotulla High School Space Heating Low Temperature Geothermal Facility Facility Cotulla High School Sector Geothermal energy Type Space Heating Location Cotulla, Texas Coordinates 28.436934°, -99.2350322° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

202

Henley High School Space Heating Low Temperature Geothermal Facility | Open  

Open Energy Info (EERE)

Henley High School Space Heating Low Temperature Geothermal Facility Henley High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Henley High School Space Heating Low Temperature Geothermal Facility Facility Henley High School Sector Geothermal energy Type Space Heating Location Klamath Falls, Oregon Coordinates 42.224867°, -121.7816704° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

203

Modoc High School Space Heating Low Temperature Geothermal Facility | Open  

Open Energy Info (EERE)

Modoc High School Space Heating Low Temperature Geothermal Facility Modoc High School Space Heating Low Temperature Geothermal Facility Jump to: navigation, search Name Modoc High School Space Heating Low Temperature Geothermal Facility Facility Modoc High School Sector Geothermal energy Type Space Heating Location Alturas, California Coordinates 41.4871146°, -120.5424555° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[]}

204

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

or chemical species in a multiphase porous medium system canand radiation in a multiphase, multicomponent, porous mediummultiphase flow, multicomponent transport, and heat transfer in porous

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

205

Flow measurement and characterization in shallow geothermal systems used for downhole heat exchanger applications  

DOE Green Energy (OSTI)

In the largest non-electrical application of geothermal energy presently occurring in the United States, over 400 relatively shallow wells are being used for extraction of energy with downhole heat exchangers. Despite this large amount of application, the exact nature of the flows in the wells has not before been characterized. Knowledge to date on the nature of flows in the systems is summarized, and an ongoing experimental program for making appropriate downhole measurements to determine flows is described in detail. Flow characterization was a principal object of this study. Horizontal cross-flows of geothermal fluid may occur at upper and/or lower levels in the well where perforations in the well casing are situated. In addition, natural convection may induce vertical flows within the well casing which would be influenced by the presence or absence of a heat exchanger. Three main aspects of the experimental program are reported on: (i) a review of potentially applicable methods for measuring vertical and horizontal flows in wells, (ii) the limitations and preliminary results of using a vane anemometer for measuring vertical flows, and (iii) the description of the selected hot-film probe, its associated pressurized calibration facility, and means of making well measurements.

Churchill, D.; Culver, G.G.; Reistad, G.M.

1977-01-01T23:59:59.000Z

206

Vibration effects of two-phase cross flow on heat exchangers  

SciTech Connect

Excessive flow-induced vibration in tube bundles causes costly tube failures by fatigue or fretting wear. This is a common condition in many shell-and-tube heat exchangers, such as condensers and reboilers. However, designers can't plan for phenomena that they don't understand. To avoid cross-flow vibration damage, the designer must determine flow-behavior effects on tube bundles under these conditions. And this is very true when discussing two-phase cross-flow vibration. Two-phase cross-flow vibration does cause tube/tube bundle failure. Early research used single-phase flow models, which failed to accurately predict vibration behavior in a two-phase system. Consequently, single-phase models and assumptions don't apply to two-phase systems and don't accurately describe vibration-behavior for exchanger tubes. Improved heat exchanger design requires more emphasis and development on cross-flow vibration parameters. The paper describes tube vibrations; flow conditions; void-fraction effects; vortex-induced vibration; fluid excitation forces; and tube response.

Lian, H.Y.; Kawaji, M. (Univ. of Toronto, Ontario (Canada)); Chan, A.M.C. (Ontario Hydro Research Div., Toronto (Canada))

1993-03-01T23:59:59.000Z

207

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

208

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

209

Fusion blanket high-temperature heat transfer  

DOE Green Energy (OSTI)

Deep penetration of 14 MeV neutrons makes two-temperature region blankets feasible. A relatively low-temperature (approx. 300/sup 0/C) metallic structure is the vacuum/coolant pressure boundary, while the interior of the blanket, which is a simple packed bed of nonstructural material, operates at very high temperatures (>1000/sup 0/C). The water-cooled shell structure is thermally insulated from the steam-cooled interior. High-temperature steam can dramatically increase the efficiency of electric power generation, as well as produce hydrogen and oxygen-based synthetic fuels at high-efficiency.

Fillo, J.A.

1983-01-01T23:59:59.000Z

210

Investigation of heat exchanger flow arrangement on performance and cost in a geothermal binary cycle  

DOE Green Energy (OSTI)

The performance of an idealized geothermal binary-fluid-cycle energy conversion system is shown to be a function of the temperatures of brine and working fluid leaving the heat exchanger. System power output, heat exchanger area required and initial well and heat exchanger costs are determined for counterflow, single and multi-pass parallel-counterflow exchangers. Results are presented graphically as functions of the brine and working fluid exit temperatures from the exchanger. Use of the system analysis developed is illustrated by showing quantitatively the advantage of the counterflow over the other flow arrangements considered.

Giedt, W.H.

1976-06-15T23:59:59.000Z

211

Fluid and heat flow in gas-rich geothermal reservoirs  

DOE Green Energy (OSTI)

Numerical-simulation techniques are used to study the effects of noncondensible gases (CO/sub 2/) on geothermal reservoir behavior in the natural state and during exploitation. It is shown that the presence of CO/sub 2/ has large effects on the thermodynamic conditions of a reservoir in the natural state, especially on temperature distributions and phase compositions. The gas will expand two-phase zones and increase gas saturations to enable flow of CO/sub 2/ through the system. During exploitation, the early pressure drop is primarily due to degassing of the system. This process can cause a very rapid initial pressure drop, on the order of tens of bars, depending upon the initial partial pressure of CO/sub 2/. The following gas content from wells can provide information on in-place gas saturations and relative permeability curves that apply at a given geothermal resource. Site-specific studies are made for the gas-rich two-phase reservoir at the Ohaki geothermal field in New Zealand. A simple lumped-parameter model and a vertical column model are applied to the field data. The results obtained agree well with the natural thermodynamic state of the Ohaki field (pressure and temperature profiles) and a partial pressure of 15 to 25 bars is calculated in the primary reservoirs. The models also agree reasonably well with field data obtained during exploitation of the field. The treatment of thermophysical properties of H/sub 2/O-CO/sub 2/ mixtures for different phase compositions is summarized.

O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.

1983-07-01T23:59:59.000Z

212

Mobile robot path planning algorithm by equivalent conduction heat flow topology optimization  

Science Conference Proceedings (OSTI)

This paper addresses the path planning problem for a point robot moving in a planar environment filled with obstacles. Our approach is based on the principles of thermal conduction and structural topology optimization and rests on the observation that, ... Keywords: Conduction heat flow, Mobile robot, Path planning, Topology optimization

Jae Chun Ryu; Frank Chongwoo Park; Yoon Young Kim

2012-05-01T23:59:59.000Z

213

Heat transfer in oscillating flows with sudden change in cross section  

DOE Green Energy (OSTI)

Oscillating fluid flow (zero mean) with heat transfer, between two parallel plates with a sudden change in cross section, was examined computationally. The flow was assumed to be laminar and incompressible with inflow velocity uniform over the channel cross section but varying sinusoidally with time. Over 30 different cases were examined; these cases cover wide ranges of Re{sub max} (187.5 to 30,000), Va (1 to 350), expansion ratio (1:2, 1:4, 1:8, and 1:12) and A{sub r} (0.68 to 4). Three different geometric cases were considered (asymmetric expansion/contraction, symmetric expansion/contraction, and symmetric blunt body). The heat transfer cases were based on constant wall temperature at higher (heating) or lower (cooling) value than inflow fluid temperature. As a result of the oscillating flow, the fluid undergoes sudden expansion in one-half of the cycle and sudden contraction in the other half. In this paper, one heating case is examined in detail, and conclusions are drawn from all the cases (documented in detail elsewhere). Instantaneous friction factors and heat transfer coefficients, for some ranges, of Re{sub max} and Va, deviated substantially from those predicted with steady-state correlations.

Ibrahim, M.; Hashim, W. [Cleveland State Univ., OH (United States); Tew, R.C.; Dudenhoefer, J.E. [Lewis Research Center, Cleveland, OH (United States)

1994-09-01T23:59:59.000Z

214

High-frequency plasma-heating apparatus  

DOE Patents (OSTI)

An array of adjacent wave guides feed high-frequency energy into a vacuum chamber in which a toroidal plasma is confined by a magnetic field, the wave guide array being located between two toroidal current windings. Waves are excited in the wave guide at a frequency substantially equal to the lower frequency hybrid wave of the plasma and a substantially equal phase shift is provided from one guide to the next between the waves therein. For plasmas of low peripheral density gradient, the guides are excited in the TE.sub.01 mode and the output electric field is parallel to the direction of the toroidal magnetic field. For exciting waves in plasmas of high peripheral density gradient, the guides are excited in the TM.sub.01 mode and the magnetic field at the wave guide outlets is parallel to the direction of the toroidal magnetic field. The wave excited at the outlet of the wave guide array is a progressive wave propagating in the direction opposite to that of the toroidal current and is, therefore, not absorbed by so-called "runaway" electrons.

Brambilla, Marco (St. Egreve, FR); Lallia, Pascal (Grenoble, FR)

1978-01-01T23:59:59.000Z

215

High heat flux engineering in solar energy applications  

DOE Green Energy (OSTI)

Solar thermal energy systems can produce heat fluxes in excess of 10,000 kW/m{sup 2}. This paper provides an introduction to the solar concentrators that produce high heat flux, the receivers that convert the flux into usable thermal energy, and the instrumentation systems used to measure flux in the solar environment. References are incorporated to direct the reader to detailed technical information.

Cameron, C.P.

1993-07-01T23:59:59.000Z

216

Effects of particle concentration and surfactant use in convective heat transfer of CuO nanofluids in microchannel flow.  

E-Print Network (OSTI)

??Heat exchange systems used in everything from cars to microelectronics have rapidly advanced in recent years to offer high heat transfer rates in increasingly smaller… (more)

Byrne, Matthew Davidson

2011-01-01T23:59:59.000Z

217

Experimental Study of Heat Transfer and Flow Characteristics for a New Type of Air Heater  

E-Print Network (OSTI)

A new type air heater was developed, and an experimental set-up was built to analyze its characteristics. Within the Reynolds number from 2000 to 15000, the integrated characteristics in air heater channels with and without holed baffles have been studied experimentally. The experimental results show that the average Nu number increases greatly but the friction factor increases only slightly with the Re number. The Webb performance evaluation criterion has been adopted for analysis purposes. It is found that the integrated characteristics of heat transfer and flow friction increase with the hole's diameter at the same hole density (which is equal to the ratio of the hole's total area to the baffle's area), and the heat transfer rate increases with the hole density at the same hole diameter. The C type baffle has the best performance at the same heat transfer surface area and fan power consumption; its heat transfer rate improves about 44 to 69 percent.

Zheng, H.; Fan, X.; Li, A.

2006-01-01T23:59:59.000Z

218

Calculation of heating values for the high flux isotope reactor  

Science Conference Proceedings (OSTI)

Calculating the amount of energy released by a fission reaction (fission Q value) and the heating rate distribution in a nuclear reactor is an important part of the safety analysis. However, these calculations can become very complex. One of the codes that can be used for this type of analyses is the Monte Carlo transport code MCNP5. Currently it is impossible to calculate the Q value and heating rate disposition for delayed beta and delayed gamma particles directly from MCNP5. The purpose of this paper is to outline a rigorous method for indirectly calculating the Q values and heating rates in the High Flux Isotope Reactor (HFIR), based on previous similar studies carried out for very high-temperature reactor configurations. This method has been applied in this study to calculate heating rates for the beginning of cycle (BOC) and end-of-cycle (EOC) states of HFIR. In addition, the BOC results obtained for HFIR are compared with corresponding results for the Advanced Test Reactor. The fission Q value for HFIR was calculated as 200.2 MeV for the BOC and 201.3 MeV for the EOC. It was also determined that 95.1% and 95.4% of the heat was deposited within the HFIR fuel plates for the BOC and EOC models, respectively. This methodology can also be used for heating rate calculations for HFIR experiments. (authors)

Peterson, J.; Ilas, G. [Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831-6172 (United States)

2012-07-01T23:59:59.000Z

219

Calculation of Heating Values for the High Flux Isotope Reactor  

SciTech Connect

Calculating the amount of energy released by a fission reaction (fission Q value) and the heating rate distribution in a nuclear reactor is an important part of the safety analysis. However, these calculations can become very complex. One of the codes that can be used for this type of analyses is the Monte Carlo transport code MCNP5. Currently it is impossible to calculate the Q value and heating rate disposition for delayed beta and delayed gamma particles directly from MCNP5. The purpose of this paper is to outline a rigorous method for indirectly calculating the Q values and heating rates in the High Flux Isotope Reactor (HFIR), based on previous similar studies carried out for very high-temperature reactor configurations. This method has been applied in this study to calculate heating rates for the beginning of cycle (BOC) and end-of-cycle (EOC) states of HFIR. In addition, the BOC results obtained for HFIR are compared with corresponding results for the Advanced Test Reactor. The fission Q value for HFIR was calculated as 200.2 MeV for the BOC and 201.3 MeV for the EOC. It was also determined that 95.1% and 95.4% of the heat was deposited within the HFIR fuel plates for the BOC and EOC models, respectively. This methodology can also be used for heating rate calculations for HFIR experiments.

Peterson, Joshua L [ORNL; Ilas, Germina [ORNL

2012-01-01T23:59:59.000Z

220

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

Note: This page contains sample records for the topic "high heat flow" 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

High frequency parametric wave phenomena and plasma heating: a review  

SciTech Connect

A survey of parametric instabilities in plasma, and associated particle heating, is presented. A brief summary of linear theory is given. The physical mechanism of decay instability, the purely growing mode (oscillating two-stream instability) and soliton and density cavity formation is presented. Effects of density gradients are discussed. Possible nonlinear saturation mechanisms are pointed out. Experimental evidence for the existence of parametric instabilities in both unmagnetized and magnetized plasmas is reviewed in some detail. Experimental observation of plasma heating associated with the presence of parametric instabilities is demonstrated by a number of examples. Possible application of these phenomena to heating of pellets by lasers and heating of magnetically confined fusion plasmas by high power microwave sources is discussed. (auth)

Porkolab, M.

1975-11-01T23:59:59.000Z

222

Structural and heat-flow implications of infrared anomalies at Mt. Hood, Oregon  

DOE Green Energy (OSTI)

Surface thermal features occur in an area of 9700 m/sup 2/ at Mt. Hood, on the basis of an aerial line-scan survey made April 26, 1973. The distribution of the thermal areas below the summit of Mt. Hood, shown on planimetrically corrected maps at 1 : 12,000, suggests structural control by a fracture system and brecciated zone peripheral to a hornblende-dacite plug dome (Crater Rock), and by a concentric fracture system that may have been associated with development of the present crater. The extent and inferred temperature of the thermal areas permits a preliminary estimate of a heat discharge of 10 megawatts, by analogy with similar fumarole and thermal fields of Mt. Baker, Washington. This figure includes a heat loss of 4 megawatts (MW) via conduction, diffusion, evaporation, and radiation to the atmosphere, and a somewhat less certain loss of 6 MW via fumarolic mass transfer of vapor and advective heat loss from runoff and ice melt. The first part of the estimate is based on two-point models for differential radiant exitance and differential flux via conduction, diffusion, evaporation, and radiation from heat balance of the ground surface. Alternate methods for estimating volcanogenic geothermal flux that assume a quasi-steady state heat flow also yield estimates in the 5-11 MW range. Heat loss equivalent to cooling of the dacite plug dome is judged to be insufficient to account for the heat flux at the fumarole fields.

Friedman, J.D.; Frank, D.

1977-01-01T23:59:59.000Z

223

Numerical investigation of electric heating impacts on solid/liquid glass flow patterns.  

SciTech Connect

A typical glass furnace consists of a combustion space and a melter. Intense heat is generated from the combustion of fuel and air/oxygen in the combustion space. This heat is transferred mainly by radiation to the melter in order to melt sand and cullet (scrap glass) eventually creating glass products. Many furnaces use electric boosters to enhance glass melting and increase productivity. The coupled electric/combustion heat transfer patterns are key to the glass making processes. The understanding of the processes can lead to the improvement of glass quality and furnace efficiency. The effects of electrical boosting on the flow patterns and heat transfer in a glass melter are investigated using a multiphase Computational Fluid Dynamics (CFD) code with addition of an electrical boosting model. The results indicate that the locations and spacing of the electrodes have large impacts on the velocity and temperature distributions in the glass melter. With the same total heat input, the batch shape (which is determined by the overall heat transfer and the batch melting rate) is kept almost the same. This indicates that electric boosting can be used to replace part of heat by combustion. Therefore, temperature is lower in the combustion space and the life of the furnace can be prolonged. The electric booster can also be used to increase productivity without increasing the furnace size.

Chang, S. L.; Zhou, C. Q.; Golchert, B.

2002-07-02T23:59:59.000Z

224

Importance of considering intraborehole flow in solute transport modeling under highly dynamic flow conditions  

SciTech Connect

Correct interpretation of tracer test data is critical for understanding transport processes in the subsurface. This task can be greatly complicated by the presence of intraborehole flows in a highly dynamic flow environment. At a new tracer test site (Hanford IFRC) a dynamic flow field created by changes in the stage of the adjacent Columbia River, coupled with a heterogeneous hydraulic conductivity distribution, leads to considerable variations in vertical hydraulic gradients. These variations, in turn, create intraborehole flows in fully-screened (6.5 m) observation wells with frequently alternating upward and downward movement. This phenomenon, in conjunction with a highly permeable aquifer formation and small horizontal hydraulic gradients, makes modeling analysis and model calibration a formidable challenge. Groundwater head data alone were insufficient to define the flow model boundary conditions, and the movement of the tracer was highly sensitive to the dynamics of the flow field. This study shows that model calibration can be significantly improved by explicitly considering (a) dynamic flow model boundary conditions and (b) intraborehole flow. The findings from this study underscore the difficulties in interpreting tracer tests and understanding solute transport under highly dynamic flow conditions.

Ma, Rui; Zheng, Chunmiao; Tonkin, Matthew J.; Zachara, John M.

2011-04-01T23:59:59.000Z

225

High Operating Temperature Liquid Metal Heat Transfer Fluids  

NLE Websites -- All DOE Office Websites (Extended Search)

Liquid Metal Liquid Metal Heat Transfer Fluids UCLA, UCB, Yale DE-EE0005941 | April 15, 2013 | Ju 1.1 Thermochemistry modeling * Continue CALPHAD based calculations to search for optimal ternary alloy compositions. * Initiate development of liquid density models. 1.2 Combinatorial synthesis and characterization * Pipe-Liquid interaction of compositional library * More alloys, alloy additions and effect on liquidus temperatures * Iteratively optimize the compositions. 1.3 Corrosion characterization and mitigation * Tune static corrosion testing systems for testing over an extended period of time. * Perform analysis of the micro mechanical testing on the oxide layers. 1.4 Heat transfer characterization and modeling * Complete the construction of the flow loop and perform experiments to measure

226

Water flow calorimetry measurements of heat loads for a volume production H/sup -/ source  

DOE Green Energy (OSTI)

The design of volume-production H/sup -/ sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs.

Purgalis, P.; Ackerman, G.; Kwan, J.; Wells, R.P.

1987-10-01T23:59:59.000Z

227

Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K  

DOE Green Energy (OSTI)

A liquid hydrogen in a absorber for muon cooling requires that up to 300 W be removed from 20 liters of liquid hydrogen. The wall of the container is a heat exchanger between the hydrogen and 14 K helium gas in channels within the wall. The warm liquid hydrogen is circulated down the cylindrical walls of the absorber by free convection. The flow of the hydrogen is studied using FEA methods for two cases and the heat transfer coefficient to the wall is calculated. The first case is when the wall is bare. The second case is when there is a duct some distance inside the cooled wall.

Green, Michael A.; Oxford U.; Yang, S.W.; Green, M.A.; Lau, W.

2004-05-08T23:59:59.000Z

228

High differential pressure, radial flow characteristics of gun perforations  

Science Conference Proceedings (OSTI)

Tubing conveyed completion techniques are being utilized more frequently than in the past, because of the apparent advantages derived from underbalanced perforating. These advantages include cleaner perforations, reductions of additional stimulation treatments and reduced completion times. This paper presents the results of a laboratory study of gun perforations made under high differential pressure, radial flow conditions. In this study, Berea sandstone cores, modified to permit radial flow, are used to determine the relationship between perforation characteristics and the time-dependent pressure differential between pore pressure (i.e. formation pressure) and ''well bore'' pressure during the completion process. The primary perforation characteristic investigated (Radial Flow Ratio) is defined as the ratio of the perforated flow rate to the flow rate of the unperforated core under identical conditions. The perforated flow rate is measured in radial flow after the perforation has been made under various time-dependent pressure differentials.

Regalbuto, J.A.; Riggs, R.S.

1985-01-01T23:59:59.000Z

229

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

E-Print Network (OSTI)

Microchannels have been studied extensively for electronic cooling applications ever since they were found to be effective in removing high heat flux from small areas. The rate of heat removed using microchannels depends on many factors including the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done so far in using Phase Change Material (PCM) fluids and pin fins in microchannels to enhance the heat transfer. PCM fluids exhibit greater heat transfer when the phase change material undergoes liquid-to-solid transformation. Staggered pins in microchannels have also shown higher heat removal characteristics because of the continuous breaking and formation of the thermal and hydrodynamic boundary layer; they also exhibit higher pressure drop because pins act as flow obstructers. This paper presents numerical results of circular, square, straight rectangular microchannels with various aspect ratios (1:2, 1:4 and 1:8), and rectangular microchannels with two characteristic staggered pins (square and circular, fixed height with no variation in aspect ratio). The heat transfer performance of a single phase fluid and PCM fluid in all of these microchannels and the corresponding pressure drop characteristics are also presented. An effective specific heat capacity model was used to account for the phase change process of PCM fluid. Comparison of heat transfer characteristics of single phase fluid and PCM fluid are presented for all the geometries considered. Among the straight microchannels, 1:8 geometry was found to have the highest Nusselt number. The use of PCM fluid in straight microchannels increased the Nusselt number by 3-7 percent compared to the single phase fluids. Among the staggered pin microchannels, circular pins were found to be more effective in terms of heat transfer by exhibiting higher Nusselt number. Circular pin microchannels were also found to have lower pressure drop compared to the square pin microchannels. Overall, for all the geometries considered, it was found that the PCM fluid enhances the heat transfer compared to the SPF fluid.

Kondle, Satyanarayana

2010-08-01T23:59:59.000Z

230

High Performance Trays and Heat Exchangers in Heat Pumped Distillation Columns  

E-Print Network (OSTI)

Vapor recompression of distillation columns overheads, followed by subsequent condensation in the reboiler results in substantial operating cost savings compared to conventional steam driven reboiler systems. The use of high performance heat exchangers and distillation trays permits additional energy savings by lower reboiler temperature differences, and reduced reflux requirements for a fixed column height, due to closer tray spacings. This paper surveys the heat pump systems currently in operation using high performance UCC MD trays and High Flux tubing. Design considerations for high or low pressure level towers, with single or dual stage compression equipment are discussed, along with the various control methods. Factors affecting startup, part load, and off design operation of the equipment are also reviewed.

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

1981-01-01T23:59:59.000Z

231

Heat flow in the Coso geothermal area, Inyo County, California | Open  

Open Energy Info (EERE)

source source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon » Heat flow in the Coso geothermal area, Inyo County, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Heat flow in the Coso geothermal area, Inyo County, California Details Activities (2) Areas (1) Regions (0) Abstract: Obvious surface manifestations of an anomalous concentration of geothermal resources at the Coso geothermal area, Inyo County, California, include fumarolic activity and associated hydrothermally altered rocks. Pleistocene volcanic rocks associated with the geothermal activity include 38 rhyolite domes occupying a north trending structural and topographic

232

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology  

DOE Green Energy (OSTI)

Airborne temperature surveys were used to depict the small surface temperature differences related to heat flow anomalies. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) had predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. Airborne temperature surveys were coordinated with field temperature surveys at Long Valley, California, the site of a known geothermal resource area. The airborne temperature surveys recorded redundant, predawn temperatures at two wavelengths and at two elevations. Overall temperature corrections were determined by calibrating dry soil surface temperatures with thermistor probes. The probes measured air and soil temperatures within 2 cm of the surface, every twenty minutes, during the survey overflights.

Del Grande, N.K.

1982-07-09T23:59:59.000Z

233

Basic study of heat flow in fusion welding. Progress report, March 1, 1980-February 28, 1981  

SciTech Connect

During the past year the study of electroslag welding was essentially completed with good agreement between the experimental and the theoretical results. It is concluded that the ESW process has certain inherent limitations which were not appreciated previously. The study has expanded into a more complete analysis of heat and fluid flow in arc welding. It has been shown that the heat affected zone and fusion zone sizes are not simple functions of the net heat input as predicted by all current theories. This will affect the choice of welding parameters. For example, in single pass arc welds, the smallest HAZ is usually desirable, while in multipass welding large HAZ's may be desirable to provide tempering of the previous weld beads. It may be possible to achieve both these goals at equivalent heat input by proper adjustment of the welding parameters (such as voltage, current and travel speed). Goal of the current study is to predict which combinations of parameters maximize or minimize the size of the heat affected zone and fusion zone at equal heat input.

Szekely, J.; Eagar, T.W.

1981-01-01T23:59:59.000Z

234

Coal plasticity at high heating rates and temperatures  

SciTech Connect

The broad objective of this project is to obtain improved, quantitative understanding of the transient plasticity of bituminous coals under high heating rates and other reaction and pretreatment conditions of scientific and practical interest. To these ends the research plan is to measure the softening and resolidification behavior of two US bituminous coals with a rapid-heating, fast response, high-temperature coal plastometer, previously developed in this laboratory. Specific measurements planned for the project include determinations of apparent viscosity, softening temperature, plastic period, and resolidificationtime for molten coal: (1) as a function of independent variations in coal type, heating rate, final temperature, gaseous atmosphere (inert, 0{sub 2} or H{sub 2}), and shear rate; and (2) in exploratory runs where coal is pretreated (preoxidation, pyridine extraction, metaplast cracking agents), before heating. The intra-coal inventory and molecular weight distribution of pyridine extractables will also be measured using a rapid quenching, electrical screen heater coal pyrolysis reactor. The yield of extractables is representative of the intra-coal inventory of plasticing agent (metaplast) remaining after quenching. Coal plasticity kinetics will then be mathematically modeled from metaplast generation and depletion rates, via a correlation between the viscosity of a suspension and the concentration of deformable medium (here metaplast) in that suspension. Work during this reporting period has been concerned with re-commissioning the rapid heating rate plastometer apparatus.

Darivakis, G.S.; Peters, W.A.; Howard, J.B.

1990-01-01T23:59:59.000Z

235

Comparing Variable Refrigerant Flow to Traditional Heating and Cooling Technologies: Assessing VRF Performance in Mobile, Alabama  

Science Conference Proceedings (OSTI)

In America, most conditioned air is delivered by ductwork, which is often made of sheet metal covered in insulation and installed during construction. However, in Japan and Europe, because the office buildings often pre-date the invention of air conditioning, it is easier and more common for refrigerant pipes to run to wall- or ceiling-mounted heat exchangers. Using refrigerant pipes instead of ducting can eliminate duct loss and offer more precise control. Are Variable Refrigerant Flow (VRF) ...

2013-09-04T23:59:59.000Z

236

Performance Assessment of a Variable Refrigerant Flow Heat Pump Air Conditioning System  

Science Conference Proceedings (OSTI)

Variable refrigerant flow (VRF) technology uses smart integrated controls, variable speed drives, and refrigerant piping to provide energy efficiency, flexible operation, ease of installation, low noise, zone control, and comfort through all-electric technology. This report describes and documents the construction, performance, and application of a heat pump air conditioning system that uses VRF technology8212the Daikin VRV system. This variable refrigerant volume (VRV) system is manufactured by Daikin I...

2008-12-17T23:59:59.000Z

237

A blow-up criterion for compressible viscous heat-conductive flows  

E-Print Network (OSTI)

We study an initial boundary value problem for the Navier-Stokes equations of compressible viscous heat-conductive fluids in a 2-D periodic domain or the unit square domain. We establish a blow-up criterion for the local strong solutions in terms of the gradient of the velocity only, which coincides with the famous Beale-Kato-Majda criterion for ideal incompressible flows.

Jiang, Song

2010-01-01T23:59:59.000Z

238

Construction of high embankment dam material flow equilibrium system  

Science Conference Proceedings (OSTI)

As high embankment dam engineering is often large-scale, how to achieve equilibrium of material flow is a critical factor affecting the construction progress of embankment dam engineering and an important approach to save resource and reduce construction ... Keywords: Embankment dam, Material flow equilibrium, Traffic network

Yan Zhang; Guo-Ping Xia

2009-07-01T23:59:59.000Z

239

High-Performance Computing and Visualization of Unsteady Turbulent Flows  

Science Conference Proceedings (OSTI)

The history of high-performance computing in turbulent flows is reviewed and their recent topics in industrial use are addressed. Special attention is paid to the validity of the method in flow visualization, and three-dimensional unsteady simulation ... Keywords: CAE, DNS, HPC, LES, turbulence

T. Kobayashi; M. Tsubokura; N. Oshima

2008-01-01T23:59:59.000Z

240

Electron heating and acceleration by magnetic reconnection in hot accretion flows  

E-Print Network (OSTI)

Both analytical and numerical works show that magnetic reconnection must occur in hot accretion flows. This process will effectively heat and accelerate electrons. In this paper we use the numerical hybrid simulation of magnetic reconnection plus test-electron method to investigate the electron acceleration and heating due to magnetic reconnection in hot accretion flows. We consider fiducial values of density, temperature, and magnetic parameter $\\beta_e$ (defined as the ratio of the electron pressure to the magnetic pressure) of the accretion flow as $n_{0} \\sim 10^{6} {\\rm cm^{-3}}$, $T_{e}^0\\sim 2\\times 10^9 {\\rm K}$, and $\\beta_e=1$. We find that electrons are heated to a higher temperature $T_{e}=5\\times 10^9$K, and a fraction $\\eta\\sim 8%$ of electrons are accelerated into a broken power-law distribution, $dN(\\gamma)\\propto \\gamma^{-p}$, with $p\\approx 1.5$ and 4 below and above $\\sim 1$ MeV, respectively. We also investigate the effect of varying $\\beta$ and $n_0$. We find that when $\\beta_e$ is smalle...

Ding, Jian; Liang, Edison

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

ELECTRON HEATING AND ACCELERATION BY MAGNETIC RECONNECTION IN HOT ACCRETION FLOWS  

Science Conference Proceedings (OSTI)

Both analytical and numerical works show that magnetic reconnection must occur in hot accretion flows. This process will effectively heat and accelerate electrons. In this paper, we use the numerical hybrid simulation of magnetic reconnection plus the test-electron method to investigate the electron acceleration and heating due to magnetic reconnection in hot accretion flows. We consider fiducial values of density, temperature, and magnetic parameter beta{sub e} (defined as the ratio of the electron pressure to the magnetic pressure) of the accretion flow as n{sub 0} approx 10{sup 6} cm{sup -3}, T {sup 0}{sub e} approx 2 x 10{sup 9} K, and beta{sub e} = 1. We find that electrons are heated to a higher temperature T{sub e} = 5 x 10{sup 9} K, and a fraction eta approx 8% of electrons are accelerated into a broken power-law distribution, dN(gamma) propor to gamma{sup -p}, with p approx 1.5 and 4 below and above approx1 MeV, respectively. We also investigate the effect of varying beta and n{sub 0}. We find that when beta{sub e} is smaller or n{sub 0} is larger, i.e., the magnetic field is stronger, T{sub e} , eta, and p all become larger.

Ding Jian; Yuan Feng [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, Shanghai 200030 (China); Liang, Edison, E-mail: fyuan@shao.ac.c [Department of Physics and Astronomy, Rice University, Houston, Texas, 77005 (United States)

2010-01-10T23:59:59.000Z

242

Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis  

E-Print Network (OSTI)

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Given the schematic diagram of TDHT system, introducing the definition of equivalent fouling roughness height, and using the Niklaus semi-rational resistance coefficient formula in rough region, the calculation methods of the sewage flow resistance are explained. Through the resistance contrastive analysis of sewage and pure mediate water, the results indicate that the mediate water sub-system is the primary design point of the TDHT system. The economical ratio of flux and velocity is determined by optimization analysis of investment and operating cost in the technical feasible range. The paper will provide reference for pipe design and pump selection of urban sewage cool or heat source applied delivery heat transfer methods.

Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

2006-01-01T23:59:59.000Z

243

Internal flow patterns on heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves using ethanol and a silver nano-ethanol mixture  

Science Conference Proceedings (OSTI)

The aim of this research was to investigate the internal flow patterns and heat transfer characteristics of a closed-loop oscillating heat-pipe with check valves (CLOHP/CV). The ratio of number of check valves to meandering turns was 0.2. Ethanol and a silver nano-ethanol mixture were used as working fluids with a filling ratio of 50% by total volume of tube. The CLOHP/CV was made of a glass tube with an inside diameter of 2.4 mm. The evaporator section was 50 mm and 100 mm in length and there were 10 meandering turns. An inclination angle of 90 from horizontal axis was established. The evaporator section was heated by an electric heater and the condenser section was cooled by distilled water. Temperature at the evaporator section was controlled at 85 C, 105 C and 125 C. The inlet and outlet temperatures were measured. A digital camera and video camera were used to observe the flow patterns at the evaporator. The silver nano-ethanol mixture gave higher heat flux than ethanol. When the temperature at the evaporator section was increased from 85 C to 105 C and 125 C. It was found that, the flow patterns occurred as annular flow + slug flow, slug flow + bubble flow and dispersed bubble flow + bubble flow respectively. The main regime of each flow pattern can be determined from the flow pattern map ethanol and a silver nano-ethanol mixture. Each of the two working fluids gave corresponding flow patterns. (author)

Bhuwakietkumjohn, N.; Rittidech, S. [Heat Pipe and Thermal Tools Design Research Laboratory (HTDR), Faculty of Engineering, Mahasarakham University, Mahasarakham 44150 (Thailand)

2010-11-15T23:59:59.000Z

244

Heat exchangers for high-temperature thermodynamic cycles  

SciTech Connect

The special requirements of heat exchangers for high temperature thermodynamic cycles are outlined and discussed with particular emphasis on cost and thermal stress problems. Typical approaches that have been taken to a comprehensive solution intended to meet all of the many boundary conditions are then considered by examining seven typical designs including liquid-to-liquid heat exchangers for nuclear plants, a heater for a closed cycle gas turbine coupled to a fluidized bed coal combustion chamber, steam generators for nuclear plants, a fossil fuel-fired potassium boiler, and a potassium condenser-steam generator. (auth)

Fraas, A.P.

1975-01-01T23:59:59.000Z

245

THE INTEGRATION OF PROCESS HEAT APPLICATIONS TO HIGH TEMPERATURE GAS REACTORS  

SciTech Connect

A high temperature gas reactor, HTGR, can produce industrial process steam, high-temperature heat-transfer gases, and/or electricity. In conventional industrial processes, these products are generated by the combustion of fossil fuels such as coal and natural gas, resulting in significant emissions of greenhouse gases such as carbon dioxide. Heat or electricity produced in an HTGR could be used to supply process heat or electricity to conventional processes without generating any greenhouse gases. Process heat from a reactor needs to be transported by a gas to the industrial process. Two such gases were considered in this study: helium and steam. For this analysis, it was assumed that steam was delivered at 17 MPa and 540 C and helium was delivered at 7 MPa and at a variety of temperatures. The temperature of the gas returning from the industrial process and going to the HTGR must be within certain temperature ranges to maintain the correct reactor inlet temperature for a particular reactor outlet temperature. The returning gas may be below the reactor inlet temperature, ROT, but not above. The optimal return temperature produces the maximum process heat gas flow rate. For steam, the delivered pressure sets an optimal reactor outlet temperature based on the condensation temperature of the steam. ROTs greater than 769.7 C produce no additional advantage for the production of steam.

Michael G. McKellar

2011-11-01T23:59:59.000Z

246

High Performance Flow Simulations on Graphics Processing Units  

NLE Websites -- All DOE Office Websites (Extended Search)

High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar HostPoint of Contact: Michael Wetter...

247

Remote high-temperature insulatorless heat-flux gauge  

DOE Patents (OSTI)

A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge.

Noel, Bruce W. (Espanola, NM)

1993-01-01T23:59:59.000Z

248

Remote high-temperature insulatorless heat-flux gauge  

DOE Patents (OSTI)

A remote optical heat-flux gauge for use in extremely high temperature environments is described. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet or laser light. The luminescence emitted by the two phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat-flux measurements can be made by scanning the light across the surface of the gauge. 3 figures.

Noel, B.W.

1993-12-28T23:59:59.000Z

249

High-temperature process heat applications with an HTGR  

SciTech Connect

An 842-MW(t) HTGR-process heat (HTGR-PH) design and several synfuels and energy transport processes to which it could be coupled are described. As in other HTGR designs, the HTGR-PH has its entire primary coolant system contained in a prestressed concrete reactor vessel (PCRV) which provides the necessary biological shielding and pressure containment. The high-temperature nuclear thermal energy is transported to the externally located process plant by a secondary helium transport loop. With a capability to produce hot helium in the secondary loop at 800/sup 0/C (1472/sup 0/F) with current designs and 900/sup 0/C (1652/sup 0/F) with advanced designs, a large number of process heat applications are potentially available. Studies have been performed for coal liquefaction and gasification using nuclear heat.

Quade, R.N.; Vrable, D.L.

1980-04-01T23:59:59.000Z

250

Remote high temperature insulatorless heat-flux gauge  

DOE Patents (OSTI)

A remote optical heat-flux gauge for use in high temperature environments. This application is possible because of the use of thermographic phosphors as the sensing media, and the omission of the need for an intervening layer of insulator between phosphor layers. The gauge has no electrical leads, but is interrogated with ultraviolet light. The luminescence emitted by the two thermographic-phosphor layers, which is indicative of the temperature of the layers, is collected and analyzed in order to determine the heat flux incident on the surface being investigated. The two layers of thermographic phosphor must be of different materials to assure that the spectral lines collected will be distinguishable. Spatial heat flux measurements can be made by scanning the light across the surface of the gauge.

Noel, B.W.

1992-12-31T23:59:59.000Z

251

Woven heat exchanger  

DOE Patents (OSTI)

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, Roger R. (Idaho Falls, ID)

1987-01-01T23:59:59.000Z

252

Numerical study on coupled fluid flow and heat transfer process in parabolic trough solar collector tube  

SciTech Connect

A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)

Tao, Y.B.; He, Y.L. [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-10-15T23:59:59.000Z

253

Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model  

SciTech Connect

Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

Sharma, Chandan; Raustad, Richard

2013-06-01T23:59:59.000Z

254

Heat-pipe development for high-temperature recuperator application  

SciTech Connect

Heat pipes have been developed for operation in oxidizing atmospheres at temperatures above 1100/sup 0/K. The heat pipes comprise a metallic liner and wick structure with a protective outer shell of an oxidation resistant material. The working fluids used in the heat pipes are alkali metals. A number of configurations have been evaluated, ranging from pipes using a metallic inner liner of a chemically vapor deposited (CVD) refractory metal applied to ceramic tubing, to one utilizing ferrous materials with an outer layer of a developed oxide. A promising intermediate configuration consisting of free-standing refractory tubing covered with a layered structure of fine grain, equi-axed CVD silicon carbide has also been evaluated. The test heat pipe was fabricated using low-carbon, arc-cast molybdenum tubing and a wick composed of 150 mesh molybdenum screen. Hafnium gettering was used with sodium working fluid. Assembly of the pipe was by electron beam welding. Following closure and capping of the fill tube the assembly was operated in a vacuum for several hours prior to the chemical vapor deposition of the exterior ceramic coating. After coating, the pipe was operated in air and in combustion gases for performance evaluation. The use of iron-chromium-aluminum alloys as container materials for operating in high temperature oxidizing and sulfiding gas streams has been investigated. Alloys of this type develop heavy, protective oxide surface layers when exposed to high temperature oxidizing atmospheres, and are commonly used in electrical heating elements because of their exceptional oxidation resistance.

Merrigan, M.; Dunwoody, W.; Lundberg, L.

1981-01-01T23:59:59.000Z

255

Performance of a glazed open flow liquid desiccant solar collector for both summer cooling and winter heating: Final report  

DOE Green Energy (OSTI)

This report documents the work performed under DOE Contract ACO3-82SF11658, entitled, ''A Research Study to Determine the Heat and Mass Transfer Characteristics of an Open Flow Solar Collector for Both Summer Cooling and Winter Heating.'' Data and computer simulation results are shown for a glazed, open flow collector used for reconcentrating a lithium chloride solution and for thermal energy collection. A comparison of the glazed collector with an unglazed collector from a previous study is also presented.

McCormick, P.O.; Brown, S.R.; Tucker, S.P.

1983-06-01T23:59:59.000Z

256

Practical method for modeling fluid and heat flow in fractured porous media  

DOE Green Energy (OSTI)

A Multiple Interacting Continua method (MINC) is presented which is applicable for numerical simulation of heat and multi-phase fluid flow in multidimensional, fractured porous media. This method is a generalization of the double-porosity concept. The partitioning of the flow domain into computational volume elements is based on the criterion of approximate thermodynamic equilibrium at all times within each element. The thermodynamic conditions in the rock matrix are assumed to be primarily controlled by the distance from the fractures, which leads to the use of nested grid blocks. The MINC concept is implemented through the Integral Finite Difference (IFD) method. No analytical approximations are made for the coupling between the fracture and matrix continua. Instead, the transient flow of fluid and heat between matrix and fractures is treated by a numerical method. The geometric parameters needed in a simulation are preprocessed from a specification of fracture spacings and apertures, and the geometry of the matrix blocks. The MINC method is verified by comparison with the analytical solution of Warren and Root. Illustrative applications are given for several geothermal reservoir engineering problems.

Pruess, K.; Narasimhan, T.N.

1982-02-01T23:59:59.000Z

257

Direct contact heat transfer between two immiscible liquids in laminar flow between parallel plates  

DOE Green Energy (OSTI)

The search for new sources of energy has prompted studies concerned with extracting energy from low temperature geothermal reservoirs which may include investigations into direct contact heat transfer due to the caustic nature of the geothermal brine. The heat transfer between two liquids of constant properties in laminar stable flow between infinite insulated horizontal parallel plates was studied. The formulation of the general problem involves two energy equations, one for each layer, which are coupled at the interfacial boundary by conditions of temperature and energy flux compatibility. The method of solution is to use the Laplace transform which then results in the necessity of using infinite series solutions with their associated recursion relationships for the coefficients. Special solutions are developed separately for the case where the fluid properties are the same and for the case of slug-flow or constant velocity. Results are presented for the dimensionless mean temperature profile of either fluid, as they are proven to be the same, as a function of the ratios of viscosities, Peclet numbers, volumetric flow rates and the axial location.

Johnson, R.W.; Jacobs, H.R.; Boehm, R.F.

1975-12-01T23:59:59.000Z

258

Reduced heat flow in light water (H2O) due to heavy water (D2O)  

E-Print Network (OSTI)

The flow of heat, from top to bottom, in a column of light water can be decreased by over 1000% with the addition of heavy water. A column of light water cools from 25 C to 0 C in 11 hours, however, with the addition of heavy water it takes more than 100 hours. There is a concentration dependence where the cooling time increases as the concentration of added (D2O) increases, with a near maximum being reached with as little as 2% of (D2O) added. This phenomenon will not occur if the water is mixed after the heavy water is added.

William R. Gorman; James D. Brownridge

2008-09-04T23:59:59.000Z

259

FUNDAMENTAL INVESTIGATION OF BOILING HEAT TRANSFER AND TWO-PHASE FLOW  

SciTech Connect

Significantly improved theories of two-phase heat transfer and prediction of departure from nucleate boiling have recently been developed which for the first time are not based on empirical relationships. These theories should be critically analyzed in relation to naval reactor work and tested with all existing data from both classified and unclassified sources. Conflicting analyses of two-phase fluid fiow regimes confuse this area, and essentially no data or theories are avsilable for twophase fiow with superimposed boiling. Theories and understanding of two-phase flow with boiling should be developed, starting from proven theories without boiling, and tested against all existing data or new data as necessary. A substantial start hss been made in analysis of the case of upward annular two-phase flow in vertical channels, based upon modern knowledge of boundary layer and vapor condensation principles. (auth)

Grohse, E.W.; Mueller, G.O.; Findlay, J.A.

1958-10-17T23:59:59.000Z

260

Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid  

E-Print Network (OSTI)

flow is developed based upon the second entropy for dynamical transitions between energy moment a molecular-dynamics trajectory was generated, and various time-dependent properties were accumulatedStatistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid

Attard, Phil

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261

Transient Heat and Material Flow Modeling of Friction Stir Processing of Magnesium Alloy using Threaded Tool  

SciTech Connect

A three-dimensional transient computational fluid dynamics (CFD) model was developed to investigate the material flow and heat transfer during friction stir processing (FSP) in an AZ31B magnesium alloy. The material was assumed to be a non-Newtonian viscoplastic fluid, and the Zener-Hollomon parameter was used to describe the dependence of material viscosity on temperature and strain rate. The material constants used in the constitutive equation were determined experimentally from compression tests of the AZ31B Mg alloy under a wide range of strain rates and temperatures. A dynamic mesh method, combining both Lagrangian and Eulerian formulations, was used to capture the material flow induced by the movement of the threaded tool pin. Massless inert particles were embedded in the simulation domain to track the detailed history of material flow. The actual FSP was also carried out on a wrought Mg plate where temperature profiles were recorded by embedding thermocouples. The predicted transient temperature history was found to be consistent with that measured during FSP. Finally, the influence of the thread on the simulated results of thermal history and material flow was studied by comparing two models: one with threaded pin and the other with smooth pin surface.

Yu, Zhenzhen [ORNL; Zhang, Wei [ORNL; Choo, Hahn [ORNL; Feng, Zhili [ORNL

2012-01-01T23:59:59.000Z

262

High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

NLE Websites -- All DOE Office Websites (Extended Search)

A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension. In this snapshot of the simulation, the stress on each suspended particle is shown color-coded with its specific value drawn on its surface. Suspended particles that have a stress value below a specific threshold value are shown in outline form in order to better view those particles that are carrying the majority of the stress in the system. This image and the software used to produce it was developed by Steven Satterfield, John Hagedorn, and John Kelso of the National Institute of Standards and Technology (NIST), and Marc Olano of NIST and the University of Maryland-Baltimore County. High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry

263

Investigation on a Microwave High-Temperature Air Heat Exchanger  

Science Conference Proceedings (OSTI)

In present paper, an energy efficient air heat exchanger, based on accumulation of the heat generated by microwave absorbing materials is presented according  ...

264

Predicting high harmonic ion cyclotron heating efficiency in Tokamak plasmas  

SciTech Connect

Observations of improved radio frequency (RF) heating efficiency in high-confinement (H-) mode plasmas on the National Spherical Tokamak Experiment (NSTX) are investigated by whole-device linear simulation. We present the first full-wave simulation to couple kinetic physics of the well confined core plasma to the poorly confined scrape-off plasma. The new simulation is used to scan the launched fast-wave spectrum and examine the steady-state electric wave field structure for experimental scenarios corresponding to both reduced, and improved RF heating efficiency. We find that launching toroidal wave-numbers that required for fast-wave propagation excites large amplitude (kVm 1 ) coaxial standing modes in the wave electric field between the confined plasma density pedestal and conducting vessel wall. Qualitative comparison with measurements of the stored plasma energy suggest these modes are a probable cause of degraded heating efficiency. Also, the H-mode density pedestal and fast-wave cutoff within the confined plasma allow for the excitation of whispering gallery type eigenmodes localised to the plasma edge.

Green, David L [ORNL; Jaeger, E. F. [XCEL; Berry, Lee A [ORNL; Chen, Guangye [ORNL; Ryan, Philip Michael [ORNL; Canik, John [ORNL

2011-01-01T23:59:59.000Z

265

High Magnetic Field Processing - A Heat-Free Heat Treating Method  

SciTech Connect

The High and Thermal Magnetic Processing/Electro-magnetic Acoustic Transducer (HTMP/EMAT) technology has been shown to be an enabling disruptive materials processing technology, that can achieve significant improvements in microstructure and consequently material performance beyond that achievable through conventional processing, and will lead to the next generation of advanced performance structural and functional materials. HTMP exposure increased the reaction kinetics enabling refinement of microstructural features such as finer martensite lath size, and finer, more copious, homogeneous dispersions of strengthening carbides leading to combined strength and toughness improvements in bainitic steels. When induction heating is applied in a high magnetic field environment, the induction heating coil is configured so that high intensity acoustic/ultrasonic treatment occurs naturally. The configuration results in a highly effective electromagnetic acoustical transducer (EMAT). HTMP combined with applying high-field EMAT, produce a non-contact ultrasonic treatment that can be used to process metal alloys in either the liquid state resulting in significant microstructural changes over conventional processing. Proof-of-principle experiments on cast irons resulted in homogeneous microstructures in small castings along with improved casting surface appearance. The experiment showed that by exposing liquid metal to the non-contact acoustic/ultrasonic processing technology developed using HMFP/EMAT wrought-like microstructures were developed in cast components. This Energy Intensive Processes (EIP) project sponsored by the DOE EERE Advanced Manufacturing Office (AMO) demonstrated the following: (1) The reduction of retained austenite in high carbon/high alloy steels with an ambient temperature HTMP process, replacing either a cryogenic or double tempering thermal process normally employed to accomplish retained austenite transformation. HTMP can be described as a 'heat-free', heat treating technology. Lower residual stresses in HTMP treated materials are anticipated since no thermal strains are involved in inducing the transformation of retained austenite to martensite in high alloy steel. (2) The simultaneous increase of 12% in yield strength and 22% in impact energy in a bainitic alloy using HTMP processing. This is a major breakthrough in materials processing for the next generation of structural materials since conventionally processed materials show a reduction in impact toughness with an increase in yield strength. HTMP is a new paradigm to beneficially increase both yield strength and impact energy absorption simultaneously. (3) HTMP processing refined both the martensite lath population and the carbide dispersion in a bainitic steel alloy during Gausstempering. The refinement was believed to be responsible for the simultaneous increase in strength and toughness. Hence, HTMP significantly impacts nucleation and growth phenomenon. (4) HTMP processing developed comparable ultimate tensile strength and twice the impact energy in a lower cost, lower alloy content ({approx}8% alloy content) steel, compared to highly alloyed, (31% alloy elements involving Ni, Co, and Mo) 250-grade margining steel. Future low-cost HTMP alloys appear viable that will exceed the structural performance of highly alloyed materials that are conventionally processed. This economic benefit will enable U.S. industry to reduce cost (better more competitive worldwide) while maintaining or exceeding current performance. (5) EMAT processed cast iron exhibits significantly higher hardness (by 51% for a 9T condition) than a no-field processed sample. (6) EMAT produced microstructures in cast iron resulted in an unique graphite nodule morphology, a modified pearlite content, and unique carbide types, that formed during solidification and cooling. (7) EMAT processed nanoparticle dispersions in Mg resulted in a very fine, unagglomerated distribution of the nanoparticles in the magnesium matrix. This provides a breakthrough technology to make the next generation of

Ludtka, Gerard Michael [ORNL; Ludtka, Gail Mackiewicz- [ORNL; Wilgen, John B [ORNL; Kenik, Edward A [ORNL; Parish, Chad M [ORNL; Rios, Orlando [ORNL; Rogers, Hiram [ORNL; Manuel, Michele [University of Florida, Gainesville; Kisner, Roger A [ORNL; Watkins, Thomas R [ORNL; Murphy, Bart L [ORNL

2012-08-01T23:59:59.000Z

266

High Performance Flow Simulations on Graphics Processing Units  

NLE Websites -- All DOE Office Websites (Extended Search)

High Performance Flow Simulations on Graphics Processing Units High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Michael Wetter Building design and operation often requires real-time or faster-than-real-time simulations for detailed information on air distributions. However, none of the current flow simulation techniques can satisfy this requirement. To solve this problem, a Fast Fluid Dynamics (FFD) model has been developed. The FFD can solve Navier-Stokes equations at a speed of 50 times faster than Computational Fluid Dynamics (CFD). In addition, the computing speed of the FFD program has been further enhanced up to 30 times by executing in parallel on a Graphics Processing Unit (GPU) instead of a Central Processing Unit (CPU). As a whole, the FFD on a GPU

267

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

Performance of ground source heat pump system in a near-zerosimulation tool for ground- source heat pump system designflow systems and ground source heat pump systems Abstract

Hong, Tainzhen

2010-01-01T23:59:59.000Z

268

DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION  

E-Print Network (OSTI)

Forced Convection Heat Transfer in Curved RectangularInfluence of Curvature on Heat Transfer to IncompressibleT. , "Forced Convective Heat Transfer in a Curved Channel

Yee, G.

2010-01-01T23:59:59.000Z

269

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

change and capillarity—the heat pipe effect, Int. J. Heatgeothermal reservoirs as heat pipes in fractured porousProcesses in Geologic Heat Pipes Jens T. Birkholzer Ernest

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

270

Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow  

E-Print Network (OSTI)

Gravity Surface Wave Bifurcation in a Highly Turbulent Swirling Flow Michael Baumer University Gravity Wave 2 3 Measurements 3 4 Mechanical Hardware: Problems and Solutions 5 5 Results 7 6 Conclusions investigated a free-surface gravity wave bifurcation in the large-separation regime, that is, where

Witten, Thomas A.

271

PERIODIC MOTION IN HIGH-SYMMETRIC FLOW Lennaert van Veen  

E-Print Network (OSTI)

is supplied by fixing the smallest wave number components of velocity. The smallest wave number corresponding to a nonzero velocity component is kf = |kf | = 11 and the energy of these fixed components is Ef = 3PERIODIC MOTION IN HIGH-SYMMETRIC FLOW Lennaert van Veen Department of Mechanical Engineering

van Veen, Lennaert

272

Heat flow studies in the Steamboat Mountain-Lemei Rock area, Skamania County, Washington. Information circular 62  

DOE Green Energy (OSTI)

In order to investigate the possible occurrence of geothermal energy in areas of Quaternary basaltic volcanism, the Washington State Department of Natural Resources drilled several 152 m deep heat-flow holes in the Steamboat Mountain-Lemei Rock area of Skamania County, Washington. The study area is located in the southern part of Washington's Cascade Mountains between 45/sup 0/54' and 46/sup 0/07' N. and 121/sup 0/40' and 121/sup 0/53'W. This area was selected for study because geologic mapping had identified a north-trending chain of late Quaternary basaltic volcanoes that had extruded a sequence of lava flows up to 600 m thick and because the chain of volcanoes is areally coincident with a well-defined gravity low with a minimum value of about -110 mgals. Gradients of 52.7 and 53.4/sup 0/C/km and heat flows of 1.8 and 1.6 ..mu..cal/cm/sup 2/sec, respectively, were measured in two drill holes near the east flank of the chain of volcanoes. Gradients of 44.5 and 58/sup 0/C/km and heat flows of 1.3 and 1.6 ..mu..cal/cm/sup 2/ sec, respectively, were measured in two holes near the axis of the chain, and one gradient of 49.8/sup 0/C/km and heat flow of 1.5 ..mu..cal/cm/sup 2/ sec were measured in a drill hole near the west flank of the chain. All gradients and heat flows are terrain corrected. These heat-flow values are typical regional heat-flow values for the Cascade Mountains. The data show that there is no large-sized heat source body within the general area of the heat-flow study. However, there is only one location in Washington, also in the Cascade Mountains, where higher gradients have been measured.

Schuster, J.E.; Blackwell, D.D.; Hammond, P.E.; Huntting, M.T.

1978-01-01T23:59:59.000Z

273

Design and demonstration of heat pipe cooling for NASP and evaluation of heating methods at high heating rates  

SciTech Connect

An evaluation of two heating methods for demonstration of NASP leading edge heat pipe technology was conducted. The heating methods were and rf induction heated plasma jet and direct rf induction. Tests were conducted to determine coupling from the argon plasma jet on a surface physically similar to a heat pipe. A molybdenum tipped calorimeter was fabricated and installed in an rf induction heated plasma jet for the test. The calorimetric measurements indicated a maximum power coupling of approximately 500 W/cm{sup 2} with the rf plasma jet. The effect of change in gas composition on the heating rate was investigated using helium. An alternative to the plasma heating of a heat pipe tip, an rf concentrator was evaluated for coupling to the hemispherical tip of a heat pipe. A refractory metal heat pipe was designed, fabricated, and tested for the evaluation. The heat pipe was designed for operation at 1400 to 1900 K with power input to 1000 W/cm{sup 2} over a hemispherical nose tip. Power input of 800 W/cm{sup 2} was demonstrated using the rf concentrator. 2 refs., 13 figs.

Merrigan, M.A.; Sena, J.T.

1989-01-01T23:59:59.000Z

274

Heat flow and geothermal gradients of Irian Jaya-Papua New Guinea: Implications for regional hydrocarbon exploration  

Science Conference Proceedings (OSTI)

Compilation of published and unpublished bottom hole temperatures (corrected for circulation times) obtained from open files and reports of the Indonesian Petroleum Association, Papua Geologic Survey, and the Southeast Asia Petroleum Society, together with published oceanographic heat flow analyses from the surrounding seas, allow an analysis of the regional heat flow and geothermal gradients of New Guinea. In two dimensions the thermal trends may be described as a pervasive west-northwest striking Cordilleran core of cool (2 HFU->4{degree}C/100 m) on the northwest, northeast, east, and southwest. As a first approximation, the heat flow may be viewed as directly proportional to the crustal thickness (as demonstrated from north-south transects across the Central Cordillera), inversely proportional to the age of the ocean crust (offshore), and perturbed by crustal heterogeneities proximal to plate boundaries (e.g., the Northern New Guinea Fault System). As a result, the heat flow distribution affords a record of post-Cretaceous tectonic activities of New Guinea. Using the spatial distribution of geothermal gradients and specific source rock ages, kinetic calculations of hydrocarbon maturities confirmed by recent drilling results suggest thermal variations through space and time that cannot be modeled simply as a function of present day static temperatures. Therefore, in terms of utilizing the present thermal information, hydrocarbon basin exploration strategies must also take into account the tectonically perturbed heat flow history of the region.

Bettis, P.K. (Expatriate-Congo, Houston, TX (USA)); Pigott, J.D. (Univ. of Oklahoma, Norman (USA))

1990-06-01T23:59:59.000Z

275

Unsteady flow and heat transfer in a channel with a built-in tandem of rectangular cylinders  

Science Conference Proceedings (OSTI)

The incompressible unsteady flow past a channel with a pair of cylinders of rectangular cross section, placed in tandem normal to the flow, is investigated by numerical simulation. The objective is to evaluate the effect of cylinder separation distance, S/H, on the flow behavior and heat transfer on the channel walls, over a range of Reynolds numbers. Above a critical Reynolds number, these flows bifurcate to a time-periodic self-sustained oscillatory state. The results reveal for S/H = 2.0 three distinct flow patterns: steady flow (Re = 200), time-periodic oscillatory state (400 {le} Re {le} 800), and quasi-periodic oscillatory flow (Re = 1,000). For S/H 600.

Valencia, A. [Universidad de Chile, Santiago (Chile). Dept. de Ingenieria Mecanica

1996-05-10T23:59:59.000Z

276

RF heating and current drive on NSTX with high  

SciTech Connect

NSTX is a small aspect ratio tokamak (R = 0.85 m, a = 0.65 m). The High Harmonic Fast Wave (HHFW) system is a 30 MHz, 12-element array capable of launching both symmetric and directional wave spectra for plasma heating and non-inductive current drive. It has delivered up to 6 MW for short pulses and has routinely operated at ~3 MW for 100-400 ms pulses. Results include strong, centrally-peaked electron heating in both D and He plasmas for both high and low phase velocity spectra. H-modes were obtained with application of HHFW power alone, with stored energy doubling after the L-H transition. Beta poloidal as large as unity has been obtained with significant fractions (0.4) of bootstrap current. Differences in the loop voltage are observed depending on whether the array is phased to drive current in the co- or counter-current directions. A fast ion tail with energies extending up to 140 keV has been observed when HHFW interacts with 80 keV neutral beams; neutron rate and lost ion measurements, as well as modeling, indicate significant power absorption by the fast ions. Radial rf power deposition and driven current profiles have been calculated with ray tracing and kinetic full-wave codes and compared with measurements.

Ryan, Philip Michael [ORNL; Peng, Yueng Kay Martin [ORNL

2003-01-01T23:59:59.000Z

277

NIST Helps Heat Pumps 'Go With the Flow' to Boost Output  

Science Conference Proceedings (OSTI)

... ARTI) under a Cooperative Research and Development Agreement (CRADA), could increase finned-tube heat exchanger heating or cooling ...

2012-03-05T23:59:59.000Z

278

A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes  

E-Print Network (OSTI)

make sure that the heat transfer processes are approximatelyfocus is on the heat and mass transfer processes within the

Birkholzer, Jens T.

2004-01-01T23:59:59.000Z

279

Secondary Heat Exchanger Design and Comparison for Advanced High Temperature Reactor  

Science Conference Proceedings (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 exchangers—helical coiled heat exchanger and printed circuit heat exchanger—as 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

280

The deterioration in heat transfer to fluids at supercritical pressure and high heat fluxes  

E-Print Network (OSTI)

At slightly supercritical pressure and in the neighborhood of the pseudo-critical temperature (defined as the temperature corresponding to the peak in specific heat at the operating pressure), the heat transfer coefficient ...

Shiralkar, B. S.

1968-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Heat pipe technology development for high temperature space radiator applications  

SciTech Connect

Technology requirements for heat pipe radiators, potentially among the lightest weight systems for space power applications, include flexible elements, and improved specific radiator performance(kg/kW). For these applications a flexible heat pipe capable of continuous operation through an angle of 180/sup 0/ has been demonstrated. The effect of bend angle on the heat pipe temperature distribution is reviewed. An analysis of lightweight membrane heat pipe radiators that use surface tension forces for fluid containment has been conducted. The design analysis of these lightweight heat pipes is described and a potential application in heat rejection systems for space nuclear power plants outlined.

Merrigan, M.A.; Keddy, E.S.; Sena, J.T.; Elder, M.G.

1984-01-01T23:59:59.000Z

282

DOE-HDBK-1012/2-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 2 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2-92 2-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 2 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019790 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

283

DOE-HDBK-1012/1-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 1 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1-92 1-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 1 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019789 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance

284

Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four  

Open Energy Info (EERE)

Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa By S E Ingebritsen, M A Scholl And D R Sherrod Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Reply To The Comment By D D Blackwell And G R Priest On Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa By S E Ingebritsen, M A Scholl And D R Sherrod Details Activities (1) Areas (1) Regions (0) Abstract: Unavailable Author(s): S. E. Ingebritsen, M. A. Scholl, D. R. Sherrod Published: Geothermics, 1996 Document Number: Unavailable DOI: Unavailable Source: View Original Journal Article Geothermal Literature Review At Breitenbush Hot Springs Area (Ingebritsen, Et Al., 1996)

285

DOE-HDBK-1012/3-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 3 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3-92 3-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 3 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019791 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

286

Heat flow of the Earth and resonant capture of solar 57-Fe axions  

E-Print Network (OSTI)

In a very conservative approach, supposing that total heat flow of the Earth is exclusively due to resonant capture inside the Earth of axions, emitted by 57-Fe nuclei on Sun, we obtain limit on mass of hadronic axion: m_aheat from decays of 40-K, 232-Th, 238-U inside the Earth, this estimation could be improved to the value: m_a<1.6 keV. Both the values are less restrictive than limits set in devoted experiments to search for 57-Fe axions (m_a<216-745 eV), but are much better than limits obtained in experiments with 83-Kr (m_a<5.5 keV) and 7-Li (m_a<13.9-32 keV).

F. A. Danevich; A. V. Ivanov; V. V. Kobychev; V. I. Tretyak

2008-11-24T23:59:59.000Z

287

Heat flow determinations and implied thermal regime of the Coso geothermal  

Open Energy Info (EERE)

determinations and implied thermal regime of the Coso geothermal determinations and implied thermal regime of the Coso geothermal area, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Heat flow determinations and implied thermal regime of the Coso geothermal area, California Details Activities (1) Areas (1) Regions (0) Abstract: Obvious surface manifestations of an anomalous concentration of geothermal energy at the Coso Geothermal Area, California, include fumarolic activity, active hot springs, and associated hydrothermally altered rocks. Abundant Pleistocene volcanic rocks, including a cluster of thirty-seven rhyolite domes, occupy a north-trending structural and topographic ridge near the center of an oval-shaped zone of late Cenozoic ring faulting. In an investigation of the thermal regime of the geothermal

288

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

Amarnath, M. Blatt, Variable refrigerant flow: where, why,simulation in the variable refrigerant flow air-conditioningsimulation of the variable refrigerant flow air conditioning

Hong, Tainzhen

2010-01-01T23:59:59.000Z

289

SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer  

NLE Websites -- All DOE Office Websites (Extended Search)

High Operating Temperature Liquid High Operating Temperature Liquid Metal Heat Transfer Fluids to someone by E-mail Share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Facebook Tweet about SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Twitter Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Google Bookmark SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Delicious Rank SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on Digg Find More places to share SunShot Initiative: High Operating Temperature Liquid Metal Heat Transfer Fluids on AddThis.com... Concentrating Solar Power Systems Components Competitive Awards

290

High-Temperature Experiments using a Resistively-Heated High-Pressure Membrane Diamond Anvil Cell  

SciTech Connect

A reliable high-performance heating method using resistive heaters and a membrane driven diamond anvil cell (mDAC) is presented. Two micro-heaters are mounted in a mDAC and use electrical power of less than 150 W to achieve sample temperatures up to 1200 K. For temperature measurement we use two K-type thermocouples mounted near the sample. The approach can be used for in-situ Raman spectroscopy and x-ray diffraction at high pressures and temperatures. A W-Re alloy gasket material permits stable operation of mDAC at high temperature. Using this method, we made an isothermal compression at 900 K to pressures in excess of 100 GPa and isobaric heating at 95 GPa to temperatures in excess of 1000 K. As an example, we present high temperature Raman spectroscopy measurements of nitrogen at high pressures.

Jenei, Z; Visbeck, K; Cynn, H; Yoo, C; Evans, W

2009-04-22T23:59:59.000Z

291

Process Heat Exchanger Options for the Advanced High Temperature Reactor  

Science Conference Proceedings (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

292

Process Heat Exchanger Options for Fluoride Salt High Temperature Reactor  

Science Conference Proceedings (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

293

Bubble confinement in flow boiling of FC-72 in a ''rectangular'' microchannel of high aspect ratio  

SciTech Connect

Boiling in microchannels remains elusive due to the lack of full understanding of the mechanisms involved. A powerful tool in achieving better comprehension of the mechanisms is detailed imaging and analysis of the two-phase flow at a fundamental level. Boiling is induced in a single microchannel geometry (hydraulic diameter 727 {mu}m), using a refrigerant FC-72, to investigate the effect of channel confinement on bubble growth. A transparent, metallic, conductive deposit has been developed on the exterior of the rectangular microchannel, allowing simultaneous uniform heating and visualisation to be achieved. The data presented in this paper is for a particular case with a uniform heat flux applied to the microchannel and inlet liquid mass flowrate held constant. In conjunction with obtaining high-speed images and videos, sensitive pressure sensors are used to record the pressure drop across the microchannel over time. Bubble nucleation and growth, as well as periodic slug flow, are observed in the microchannel test section. The periodic pressure fluctuations evidenced across the microchannel are caused by the bubble dynamics and instances of vapour blockage during confined bubble growth in the channel. The variation of the aspect ratio and the interface velocities of the growing vapour slug over time, are all observed and analysed. We follow visually the nucleation and subsequent both 'free' and 'confined' growth of a vapour bubble during flow boiling of FC-72 in a microchannel, from analysis of our results, images and video sequences with the corresponding pressure data obtained. (author)

Barber, Jacqueline [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom); Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Brutin, David; Tadrist, Lounes [Aix-Marseille Universite (UI, UII) - CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille 13453 (France); Sefiane, Khellil [School of Engineering, University of Edinburgh, The King's Buildings, Mayfield Road, Edinburgh, EH9 3JL (United Kingdom)

2010-11-15T23:59:59.000Z

294

High Performance Catalytic Heat Exchanger for SOFC Systems - FuelCell Energy  

NLE Websites -- All DOE Office Websites (Extended Search)

Catalytic Heat Catalytic Heat Exchanger for SOFC Systems-FuelCell Energy Background In a typical solid oxide fuel cell (SOFC) power generation system, hot (~900 °C) effluent gas from a catalytic combustor serves as the heat source within a high-temperature heat exchanger, preheating incoming fresh air for the SOFC's cathode. The catalytic combustor and the cathode air heat exchanger together represent the largest opportunity for cost

295

High performance in low-flow solar domestic hot water systems  

DOE Green Energy (OSTI)

Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

Dayan, M.

1997-12-31T23:59:59.000Z

296

Numerical simulation of flow distribution for pebble bed high temperature gas cooled reactors  

E-Print Network (OSTI)

The premise of the work presented here is to use a common analytical tool, Computational Fluid dynamics (CFD), along with a difference turbulence models. Eddy viscosity models as well as state-of-the-art Large Eddy Simulation (LES) were used to study the flow past bluff bodies. A suitable CFD code (CFX5.6b) was selected and implemented. Simulation of turbulent transport for the gas through the gaps of the randomly distributed spherical fuel elements (pebbles) was performed. Although there are a number of numerical studies () on flows around spherical bodies, none of them use the necessary turbulence models that are required to simulate flow where strong separation exists. With the development of high performance computers built for applications that require high CPU time and memory; numerical simulation becomes one of the more effective approaches for such investigations and LES type of turbulence models can be used more effectively. Since there are objects that are touching each other in the present study, a special approach was applied at the stage of building computational domain. This is supposed to be a considerable improvement for CFD applications. Zero thickness was achieved between the pebbles in which fission reaction takes place. Since there is a strong pressure gradient as a result of high Reynolds Number on the computational domain, which strongly affects the boundary layer behavior, heat transfer in both laminar and turbulent flows varies noticeably. Therefore, noncircular curved flows as in the pebble-bed situatio n, in detailed local sense, is interesting to be investigated. Since a compromise is needed between accuracy of results and time/cost of effort in acquiring the results numerically, selection of turbulence model should be done carefully. Resolving all the scales of a turbulent flow is too costly, while employing highly empirical turbulence models to complex problems could give inaccurate simulation results. The Large Eddy Simulation (LES) method would achieve the requirements to obtain a reasonable result. In LES, the large scales in the flow are solved and the small scales are modeled. Eddy viscosity and Reynolds stress models were also be used to investigate the applicability of these models for this kind of flow past bluff bodies at high Re numbers.

Yesilyurt, Gokhan

2006-05-01T23:59:59.000Z

297

Novel Charging Station and Computational Modeling for High Thermal Conductivity Heat Pipe Thermal Ground Planes.  

E-Print Network (OSTI)

??Thermal ground planes (TGPs) are planar, thin (thickness of 3 mm or less) heat pipes which use two-phase heat transfer. TGPs are innovative high-performance, integrated… (more)

Ababneh, Mohammed

2012-01-01T23:59:59.000Z

298

Thulium heat source for high-endurance and high-energy density power systems  

DOE Green Energy (OSTI)

We are studying the performance characteristics of radioisotope heat source designs for high-endurance and high-energy-density power systems that use thulium-170. Heat sources in the power range of 5--50 kW{sub th} coupled with a power conversion efficiency of {approximately}30%, can easily satisfy current missions for autonomous underwater vehicles. New naval missions will be possible because thulium isotope power systems have a factor of one-to-two hundred higher endurance and energy density than chemical and electrochemical systems. Thulium-170 also has several other attractive features, including the fact that it decays to stable ytterbium-170 with a half-life of four months. For terrestrial applications, refueling on that time scale should be acceptable in view of the advantage of its benign decay. The heat source designs we are studying account for the requirements of isotope production, shielding, and integration with power conversion components. These requirements are driven by environmental and safety considerations. Thulium is present in the form of thin refractory thulia disks that allow power conversion at high peak temperature. We give estimates of power system state points, performance, mass, and volume characteristics. Monte Carlo radiation analysis provides a detailed assessment of shield requirements and heat transfer under normal and distressed conditions is also considered. 11 refs., 7 figs., 4 tabs.

Walter, C.E.; Kammeraad, J.E.; Van Konynenburg, R.; VanSant, J.H.

1991-05-01T23:59:59.000Z

299

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

A schematic of the heat pipe problem (from Updegraff [1989])19. A schematic of the heat pipe problem (from Updegraff[Numerical Modeling of a Porous Heat Pipe: Comparison with a

Moridis, G.J.

2010-01-01T23:59:59.000Z

300

Heat transfer and fluid flow characteristics of microchannels with internal longitudinal fins.  

E-Print Network (OSTI)

??Electronic components generate large amount of heat during their operation, which requires to be dissipated. Over the past decade, internal heat generation levels have exponentially… (more)

Foong, Andrew Jun Li

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Subcooled flow boiling heat transfer and critical heat flux in water-based nanofluids at low pressure  

E-Print Network (OSTI)

A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In this ...

Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

302

Long titanium heat pipes for high-temperature space radiators  

SciTech Connect

Titanium heat pipes are being developed to provide light weight, reliable heat rejection devices as an alternate radiator design for the Space Reactor Power System (SP-100). The radiator design includes 360 heat pipes, each of which is 5.2 m long and dissipates 3 kW of power at 775 K. The radiator heat pipes use potassium as the working fluid, have two screen arteries for fluid return, a roughened surface distributive wicking system, and a D-shaped cross-section container configuration. A prototype titanium heat pipe, 5.5-m long, has been fabricated and tested in space-simulating conditions. Results from startup and isothermal operation tests are presented. These results are also compared to theoretical performance predictions that were used to design the heat pipe initially.

Girrens, S.P.; Ernst, D.M.

1982-01-01T23:59:59.000Z

303

Heat Transfer and Fluid Flow of Benard-Cell Convection in Rectangular Container with Free Surface Sensed by Infrared Thermography  

Science Conference Proceedings (OSTI)

The natural convection flow phenomena that occur inside an enclosed space are very interesting examples of complex fluid systems that may yield to analytical, empirical and numerical solutions, and many reports have looked into this basic problem. In ... Keywords: Gas-liquid Interface, Heat Transfer, Infrared Thermography, Natural Convection, Thermal Visualization, Turbulence

T. Inagaki; M. Hatori; T. Suzuki; Y. Shiina

2006-04-01T23:59:59.000Z

304

Experiments in the ISX-B tokamak electron cyclotron heating, ripple studies, pellet fueling, impurity flow reversal and surface physics  

DOE Green Energy (OSTI)

The wide variety of experiments on the ISX-B tokamak includes electron cyclotron heating, ripple effects, hydrogen pellet fueling, impurity flow reversal mechanisms, plasma edge studies, and testing of limiter coatings. The most significant results in each of these areas are discussed.

Isler, R.C. [Oak Ridge National Laboratory (ORNL); Peng, Yueng Kay Martin [ORNL

1981-01-01T23:59:59.000Z

305

Pressure drop, heat transfer, critical heat flux, and flow stability of two-phase flow boiling of water and ethylene glycol/water mixtures - final report for project "Efficent cooling in engines with nucleate boiling."  

SciTech Connect

Because of its order-of-magnitude higher heat transfer rates, there is interest in using controllable two-phase nucleate boiling instead of conventional single-phase forced convection in vehicular cooling systems to remove ever increasing heat loads and to eliminate potential hot spots in engines. However, the fundamental understanding of flow boiling mechanisms of a 50/50 ethylene glycol/water mixture under engineering application conditions is still limited. In addition, it is impractical to precisely maintain the volume concentration ratio of the ethylene glycol/water mixture coolant at 50/50. Therefore, any investigation into engine coolant characteristics should include a range of volume concentration ratios around the nominal 50/50 mark. In this study, the forced convective boiling heat transfer of distilled water and ethylene glycol/water mixtures with volume concentration ratios of 40/60, 50/50, and 60/40 in a 2.98-mm-inner-diameter circular tube has been investigated in both the horizontal flow and the vertical flow. The two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux of the test fluids were determined experimentally over a range of the mass flux, the vapor mass quality, and the inlet subcooling through a new boiling data reduction procedure that allowed the analytical calculation of the fluid boiling temperatures along the experimental test section by applying the ideal mixture assumption and the equilibrium assumption along with Raoult's law. Based on the experimental data, predictive methods for the two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux under engine application conditions were developed. The results summarized in this final project report provide the necessary information for designing and implementing nucleate-boiling vehicular cooling systems.

Yu, W.; France, D. M.; Routbort, J. L. (Energy Systems)

2011-01-19T23:59:59.000Z

306

Study on the Interfacial Heat Transfer Coefficient of High Pressure ...  

Science Conference Proceedings (OSTI)

The heat transfer behavior between an AM60B alloy casting and die during .... for Spent Nuclear Fuel and Measuring the Composition of Molten Salt by Using ...

307

Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States  

Science Conference Proceedings (OSTI)

Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

2000-04-01T23:59:59.000Z

308

Heat Transfer in Rectangular Channels (AR=2:1) of the Gas Turbine Blade at High Rotation Numbers  

E-Print Network (OSTI)

Gas turbine blade/vane cooling is obtained by circulating the high pressure air from compressor to the internal cooling passage of the blade/vane. Heat transfer and cooling effect in the rotating blade is highly affected by rotation. The typical rotation number for the aircraft engine is in the range of 0~0.25 and for the land based power generation turbine in the range of 0~05. Currently, the heat transfer data at high rotation numbers are limited. Besides, the investigation of heat transfer phenomena in the turn region, especially near hub portion is rare. This dissertation is to study the heat transfer in rectangular channels with turns in the tip or the hub portion respectively at high rotation numbers close to the engine condition. The dissertation experimentally investigates the heat transfer phenomena in a two-pass rectangular channel (AR=W/H=2:1) with a 180 degree sharp turn in the tip portion. The flow in the first passage is radial outward and after the turn in the second passage, the flow direction is radial inward. The hydraulic diameter (Dh) of the channel is 16.9 mm. Parallel square ribs with an attack angle (alpha) of 45 degrees are used on leading and trailing surfaces to enhance the heat transfer. The rib height-to-hydraulic diameter ratio (e/Dh) is 0.094. For the baseline smooth case and the case with rib pitch-to-height ratio (P/e) 10, channel orientation angles (beta) of 90 degrees and 135 degrees were tried to model the cooling passage in the mid and rear portion of the blade respectively. Two other P/e ratios of 5 and 7.5 were studied at beta=135 degrees to investigate their effect on heat transfer. The data are presented under high rotation numbers and buoyancy parameters by varying the Reynolds number (Re=10,000~40,000) and rotation speed (rpm=0~400). Corresponding rotation number and buoyancy parameter are ranged as 0~0.45 and 0~0.8 respectively. The dissertation also studies the heat transfer in a two-pass channel (AR=2:1) connected by a 180 degree U bend in the hub portion. The flow in the first passage is radial inward and after the U bend, the flow in the second passage is radial outward. The cross-section dimension of this channel is the same as the previous one. To increase heat transfer, staggered square ribs (e/Dh=0.094) are pasted on leading and trailing walls with an attack angle (alpha) of 45 degrees and pitch-to-height ratio (P/e) of 8. A turning vane in the shape of half circle (R=18.5 mm, t=1.6 mm) is used in the turn region to guide the flow for both smooth and ribbed cases. Channel orientation angles (beta) of 90 degrees and 135 degrees were taken for both smooth and ribbed cases. The heat transfer data were taken at high rotation numbers close to previous test section.

Lei, Jiang 1980-

2011-08-01T23:59:59.000Z

309

Evaporation heat transfer and friction characteristics of R-134a flowing downward in a vertical corrugated tube  

SciTech Connect

Differently from most previous studies, the heat transfer and friction characteristics of the pure refrigerant HFC-134a during evaporation inside a vertical corrugated tube are experimentally investigated. The double tube test sections are 0.5 m long with refrigerant flowing in the inner tube and heating water flowing in the annulus. The inner tubes are one smooth tube and two corrugated tubes, which are constructed from smooth copper tube of 8.7 mm inner diameter. The test runs are performed at evaporating temperatures of 10, 15, and 20 C, heat fluxes of 20, 25, and 30 kW/m{sup 2}, and mass fluxes of 200, 300, and 400 kg/m{sup 2} s. The quality of the refrigerant in the test section is calculated using the temperature and pressure obtained from the experiment. The pressure drop across the test section is measured directly by a differential pressure transducer. The effects of heat flux, mass flux, and evaporation temperature on the heat transfer coefficient and two-phase friction factor are also discussed. It is found that the percentage increases of the heat transfer coefficient and the two-phase friction factor of the corrugated tubes compared with those of the smooth tube are approximately 0-10% and 70-140%, respectively. (author)

Aroonrat, Kanit; Wongwises, Somchai [Fluid Mechanics, Thermal Engineering and Multiphase Flow Research Lab. (FUTURE), Department of Mechanical Engineering, King Mongkut's University of Technology Thonburi, Bangmod, Bangkok 10140 (Thailand)

2011-01-15T23:59:59.000Z

310

TOUGH: a numerical model for nonisothermal unsaturated flow to study waste canister heating effects  

Science Conference Proceedings (OSTI)

The physical processes modeled and the mathematical and numerical methods employed in a simulator for non-isothermal flow of water, vapor, and air in permeable media are briefly summarized. The simulator has been applied to study thermo-hydrological conditions in the near vicinity of high-level nuclear waste packages emplaced in unsaturated rocks. The studies reported here specifically address the question whether or not the waste canister environment will dry up in the thermal phase. 13 references, 8 figures, 2 tables.

Pruess, K.; Wang, J.S.Y.

1983-12-01T23:59:59.000Z

311

Continental margin subsidence and heat flow: important parameters in formation of petroleum hydrocarbons  

Science Conference Proceedings (OSTI)

Passive continental margins have been shown to subside with a 50-My exponentially decaying rate which cannot be explained by isostatic compensation for sediment loading. This suggests that the subsidence is dominated by geodynamic processes similar to those in the deep ocean. Two simple geologic models for continental breakup are developed: (1) attenuation of continental lithosphere; and (2) intrusion of mantle diapirs. These models for rifting give a direct relation between subsidence of passive margins and their surface heat flow through time. On this basis we develop a method of reconstructing the thermal history of sedimentary strata from regional subsidence and sedimentation history. Because generation of petroleum hydrocarbons depends on the intergrated time/temperature history of buried organic material, this reconstruction technique can be used to determine the depth to the oil range of the hydrocarbon generation window in advance of drilling. By way of example, we reconstruct time/temperature/depth plots and estimate hydrocarbon maturity for one site in the Falkland Plateau and three sites in the North Atlantic near Cape Hatteras. In addition to providing a method for evaluating hydrocarbon potential in frontier regions where there is little or no well control, this approach suggests that there may be significant potential for oil and gas generation on the outer part of the continental rise and in deep-sea sedimentary basins. 13 figures, 1 table.

Royden, L. (Massachusetts Inst. of Tech., Cambridge); Sclater, J.G.; Von Herzen, R.P.

1980-02-01T23:59:59.000Z

312

The 1983 Temperature Gradient and Heat Flow Drilling Project for the State of Washington  

DOE Green Energy (OSTI)

During the Summer of 1983, the Washington Division of Geology and Earth Resources carried out a three-hole drilling program to collect temperature gradient and heat flow information near potential geothermal resource target areas. The project was part of the state-coupled US Department of Energy Geothermal Program. Richardson Well Drilling of Tacoma, Washington was subcontracted through the State to perform the work. The general locations of the project areas are shown in figure 1. The first hole, DNR 83-1, was located within the Green River valley northwest of Mount St. Helens. This site is near the Green River Soda Springs and along the projection of the Mount St. Helens--Elk Lake seismic zone. The other two holes were drilled near Mount Baker. Hole DNR 83-3 was sited about 1/4 km west of the Baker Hot Springs, 10.5 km east of Mount Baker, while hole DNR 83-5 was located along Rocky Creek in the Sulphur Creek Valley. The Rocky Creek hole is about 10 km south-southwest of the peak. Two other holes, DNR 83-2 and DNR 83-4, were located on the north side of the Sulphur Creek Valley. Both holes were abandoned at early stages of drilling because of deep overburden and severe caving problems. The sites were apparently located atop old landslide deposits.

Korosec, Michael A.

1983-11-01T23:59:59.000Z

313

1983 temperature gradient and heat flow drilling project for the State of Washington  

DOE Green Energy (OSTI)

During the Summer of 1983, a three-hole drilling program was carried out to collect temperature gradient and heat flow information near potential geothermal resource target areas. The general locations of the project areas are shown. The first hole, DNR 83-1, was located within the Green River valley northwest of Mount St. Helens. This site is near the Green River Soda Springs and along the projection of the Mount St. Helens - Elk Lake seismic zone. The other two holes were drilled near Mount Baker. Hole DNR 83-3 was sited about 1/4 km west of the Baker Hot Springs, 10.5 km east of Mount Baker, while hole DNR 83-5 was located along Rocky Creek in the Sulphur Creek Valley. The Rocky Creek hole is about 10 km south-southwest of the peak. Two other holes, DNR 83-2 and DNR 83-4, were located on the north side of the Sulphur Creek Valley. Both holes were abandoned at early stages of drilling because of deep overburden and severe caving problems. The sites were apparently located atop old landslide deposits.

Korosec, M.A.

1983-11-01T23:59:59.000Z

314

Proximity functions for modeling fluids and heat flow in reservoirs with stochastic fracture distributions  

DOE Green Energy (OSTI)

Conventional approaches to geothermal reservoir modeling have employed a porous medium approximation, but recently methods have been developed which can take into account the different thermodynamic conditions in rock matrix and fractures. The multiple interacting continua method (MINC) treats the thermal and hydraulic interaction between rock matrix and fractures in terms of a set of geometrical parameters. However, this approach was restricted to idealized fracture distributions with regularly shaped matrix blocks. Fractures in geothermal reservoirs usually occur in nearly parallel sets with a certain scatter in orientation, and a stochastic distribution of spacings and apertures. The MINC-method was extended to realistic fracture systems with stochastic distributions. The interaction between matrix and fractures is parameterized in terms of a proximity function, which represents the volume of matrix rock as a function of distance from the fractures. Monte Carlo techniques were employed to compute proximity functions for a number of two-dimensional systems with regular or stochastic fracture distributions. It is shown how the proximity functions can be used to generate computational grids for modeling fluid and heat flow in fractured reservoirs.

Pruess, K.; Karasaki, K.

1982-10-01T23:59:59.000Z

315

High Efficiency R-744 Commercial Heat Pump Water Heaters  

SciTech Connect

The project investigated the development and improvement process of a R744 (CO2) commercial heat pump water heater (HPWH) package of approximately 35 kW. The improvement process covered all main components of the system. More specific the heat exchangers (Internal heat exchanger, Evaporator, Gas cooler) as well as the expansion device and the compressor were investigated. In addition, a comparison to a commercially available baseline R134a unit of the same capacity and footprint was made in order to compare performance as well as package size reduction potential.

Elbel, Dr. Stefan W.; Petersen, Michael

2013-04-25T23:59:59.000Z

316

High Operating Temperature Heat Transfer Fluids for Solar Thermal...  

NLE Websites -- All DOE Office Websites (Extended Search)

Heat Transfer Fluids for Solar Thermal Power Generation UCLA, UCB, Yale Award Number: DE-EE0005941 | January 9, 2013 | Sungtaek Ju 1.1 Thermochemistry modeling Identified promising...

317

Failure Analysis of the Heat Exchanger Tubes Exposed to High ...  

Science Conference Proceedings (OSTI)

The bundle of the heat exchanger was removed from service after 8 years for metallurgical investigation. The tube side contains boiler feed water at 622oF and  ...

318

Cross flow heat exchange of textile cellular metal core sandwich panels , T.J. Lu b,*, H.P. Hodson a  

E-Print Network (OSTI)

Cross flow heat exchange of textile cellular metal core sandwich panels J. Tian a , T.J. Lu b,*, H. Finally, the thermal performance of brazed woven tex- tiles is compared with other heat exchanger media be used as heat exchangers, node rotation precludes their use as structural members. In addition

Wadley, Haydn

319

Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor  

SciTech Connect

Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 Degree-Sign C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 Degree-Sign C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

Cao Wei, E-mail: cawe-001@163.com [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Li Jing, E-mail: lijing02@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Burn and Plastic Surgery (China); Wu Zhiqun, E-mail: zhiqunwu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Interventional Radiology (China); Zhou Changxi, E-mail: changxizhou@163.com [Chinese PLA General Hospital, Department of Respiratory Disease (China); Liu Xi, E-mail: xiliu@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China); Wan Yi, E-mail: yiwan@163.com [The Fourth Military Medical University, Department of Health Statistics, Institute for Health Informatics (China); Duan Yunyou, E-mail: yunyouduan@fmmu.edu.cn [Tangdu Hospital, The Fourth Military Medical University, Department of Ultrasound Diagnostics (China)

2013-06-15T23:59:59.000Z

320

High speed flow cytometer droplet formation system and method  

DOE Patents (OSTI)

A droplet forming flow cytometer system allows high speed processing without the need for high oscillator drive powers through the inclusion of an oscillator or piezoelectric crystal such as within the nozzle volume or otherwise unidirectionally coupled to the sheath fluid. The nozzle container continuously converges so as to amplify unidirectional oscillations which are transmitted as pressure waves through the nozzle volume to the nozzle exit so as to form droplets from the fluid jet. The oscillator is directionally isolated so as to avoid moving the entire nozzle container so as to create only pressure waves within the sheath fluid. A variation in substance concentration is achieved through a movable substance introduction port which is positioned within a convergence zone to vary the relative concentration of substance to sheath fluid while still maintaining optimal laminar flow conditions. This variation may be automatically controlled through a sensor and controller configuration. A replaceable tip design is also provided whereby the ceramic nozzle tip is positioned within an edge insert in the nozzle body so as to smoothly transition from nozzle body to nozzle tip. The nozzle tip is sealed against its outer surface to the nozzle body so it may be removable for cleaning or replacement.

Van den Engh, Ger (Seattle, WA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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321

Downward two-phase flow effects in heat-loss and pressure-drop modeling of steam injection wells  

SciTech Connect

Modelling of the pressure drop and heat loss in steam injection wells has undergone a gradual evolution since the heavy interest in enhanced oil recovery by steam injection in the mid-60's. After briefly reviewing the evolution of steam models this paper presents a model which advances the state-of-the-art of steam modelling. The main advance presented in this paper is modelling the effects of the various flow regimens that occur during steam injection. The paper describes the formulation of a two-phase downward vertical flow pressure drop model which is not limited by the ''no-slip'' homogeneous flow assumptions in most previously published models. By using different correlations for mist, bubble, and slug flow, improved pressure drop calculations result, which in turn improve temperature predictions. The paper describes how the model handles temperature predictions differently in the single and two-phase steam flow situations. The paper also describes special features in the model to account for layered soil properties, soil dry out, cyclic injection, coupling heat losses, and reflux boiling in wet annuli. Two examples problems are presented which illustrate some of these features.

Galate, J.W.; Mitchell, R.F.

1985-03-01T23:59:59.000Z

322

Industrial Waste Heat Recovery Opportunities: An Update on Industrial High Temperature Heat Pump Technologies  

Science Conference Proceedings (OSTI)

It is estimated that as much as 20% to 50% of energy consumed is lost via waste heat contained in streams of exhaust gases and hot liquids, as well as through conduction, convection or radiation emanating from the surface of hot equipment. It is also estimated that in some cases, such as industrial furnaces, efficiency improvements resulting from waste heat recovery can improve efficiency by 10% to as much as 50%. This technical update is a continuation of research conducted by the Electric Power ...

2013-12-04T23:59:59.000Z

323

NUCLEAR FLUID DYNAMICS VERSUS INTRANUCLEAR CASCADE--POSSIBLE EVIDENCE FOR COLLECTIVE FLOW IN CENTRAL HIGH ENERGY NUCLEAR COLLISIONS  

E-Print Network (OSTI)

Flow in Central High Energy Nuclear Collisions H. Stockera,under Contract High energy nuclear collisions offer a uniquesidewards flow·in high-energy nuclear collisions. The

Stocker, H.

2012-01-01T23:59:59.000Z

324

Results of temperature gradient and heat flow in Santiam Pass Area, Oregon, Volume 1  

DOE Green Energy (OSTI)

The conclusions of this report are: (1) There is a weakly defined thermal anomaly within the area examined by temperature-gradient holes in the Santiam Pass area. This is a relict anomaly showing differences in permeability between the High Cascades and Western Cascades areas, more than a fundamental difference in shallow crustal temperatures. (2) The anomaly as defined by the 60 F isotherms at 400 feet follows a north-south trend immediately westward of the Cascade axis in the boundary region. It is clear that all holes spudded into High Cascades rocks result in isothermal and reversal gradients. Holes spudded in Western Cascades rocks result in positive gradients. (3) Cold groundwater flow influences and masks temperature gradients in the High Cascades to a depth of at least 700 feet, especially eastward from the major north-south trending faults. Pleistocene and Holocene rocks are very permeable aquifers. (4) Shallow gradient drilling in the lowlands westward of the faults provides more interpretable information than shallow drilling in the cold-water recharge zones. Topographic and climatological effects can be filtered out of the temperature gradient results. (5) The thermal anomaly seems to have 2 centers: one in the Belknap-Foley area, and one northward in the Sand Mountain area. The anomalies may or may not be connected along a north-south trend. (6) A geothermal effect is seen in holes downslope of the Western-High Cascade boundary. Mixing with cold waters is a powerful influence on temperature gradient data. (7) The temperature-gradient program has not yet examined and defined the geothermal resources potential of the area eastward of the Western Cascades-High Cascades boundary. Holes to 1500-2000 feet in depth are required to penetrate the high permeability-cold groundwater regime. (8) Drilling conditions are unfavorable. There are very few accessible level drill sites. Seasonal access problems and environmental restrictions together with frequent lost circulation results in very high costs per foot drilled.

Cox, B.L.; Gardner, M.C.; Koenig, J.B.

1981-08-01T23:59:59.000Z

325

Simulation of a High Efficiency Multi-bed Adsorption Heat Pump  

Science Conference Proceedings (OSTI)

Attaining high energy efficiency with adsorption heat pumps is challenging due to thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. The multi-bed concept described here effectively transfers heat from beds being cooled to beds being heated, which enables high efficiency in thermally driven heat pumps. A simplified lumped-parameter model and detailed finite element analysis are used to simulate the performance of an ammonia-carbon sorption compressor, which is used to project the overall heat pump coefficient of performance. The effects of bed geometry and number of beds on system performance are explored, and the majority of the performance benefit is obtained with four beds. Results indicate that a COP of 1.24 based on heat input is feasible at AHRI standard test conditions for residential HVAC equipment. When compared on a basis of primary energy input, performance equivalent to SEER 13 or 14 are theoretically attainable with this system.

TeGrotenhuis, Ward E.; Humble, Paul H.; Sweeney, J. B.

2012-05-01T23:59:59.000Z

326

Study of high energy ion loss during hydrogen minority heating in TFTR  

DOE Green Energy (OSTI)

High energy ion loss during hydrogen minority ICRF heating is measured and compared with the loss of the D-D fusion products. During H minority heating a relatively large loss of high energy ions is observed at 45{degrees} below the outer midplane, with or without simultaneous NBI heating. This increase is most likely due to a loss of the minority tail protons, a possible model for this process is described.

Park, J.; Zweben, S.J.

1994-03-01T23:59:59.000Z

327

Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b  

E-Print Network (OSTI)

in saturated pool boiling. In this model the analysis of heat conduction within the heater is added on the heater surface itself [10]. Bhat et al. [11] put forward a theoretical model of macrolayer formation to their model and ob- tained the simulated boiling curve of water. In addition, they compared Haramura and Katto

Maruyama, Shigeo

328

Gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts  

E-Print Network (OSTI)

We investigate the gravitational collapse of a spherically symmetric, inhomogeneous star, which is described by a perfect fluid with heat flow and satisfies the equation of state $p=\\rho/3$ at its center. In the process of the gravitational collapsing, the energy of the whole star is emitted into space. And the remaining spacetime is a Minkowski one without a remnant at the end of the process. For a star with a solar mass and solar radius, the total energy emitted is at the order of $10^{54}$ {\\rm erg}, and the time-scale of the process is about $8s$. These are in the typical values for a gamma-ray burst. Thus, we suggest the gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts.

Zhe Chang; Cheng-Bo Guan; Chao-Guang Huang; Xin Li

2008-03-26T23:59:59.000Z

329

Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data  

Science Conference Proceedings (OSTI)

In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data.

Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

1990-05-01T23:59:59.000Z

330

Handbook of radiative heat transfer in high-temperature gases  

Science Conference Proceedings (OSTI)

This work offers both an original method for calculating optical properties of low-temperature plasma at elevated densities ... and an effective new means for calculating radiative heat transfer in hot gases and plasma with arbitrary temperature and pressure distributions. These methods allow for automatic accounting of all details of the plasma spectrum, including the line structure. This volume contains radiant transfer in problems of heat transfer; integration over frequency; methods of partial characteristics; method of effective populations; calculation of partial characteristics; appendix: tabular data.

Soloukhin, R.I.; Golovnev, I.F.; Zamurayev, V.P.; Katsnelson, S.S.; Kovalskaya, G.A.; Sevastyanenko, V.G.; Soloukhin, R.I.

1987-01-01T23:59:59.000Z

331

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

Science Conference Proceedings (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

332

PC-based fluid and heat transfer analyzer for two-phase flow in pipes.  

E-Print Network (OSTI)

??Modeling the simultaneous flow of gas and liquid or two-phase gas-liquid flow in pipes is a key aspect in petroleum production. These models can enhance… (more)

Afonja, Gbolahan.

2006-01-01T23:59:59.000Z

333

Device for plasma confinement and heating by high currents and nonclassical plasma transport properties  

DOE Patents (OSTI)

A toroidal plasma containment device having means for inducing high total plasma currents and current densities and at the same time emhanced plasma heating, strong magnetic confinement, high energy density containment, magnetic modulation, microwaveinduced heating, and diagnostic accessibility is described. (Official Gazette)

Coppi, B.; Montgomery, D.B.

1973-12-11T23:59:59.000Z

334

Alternatives Generation and Analysis for Heat Removal from High Level Waste Tanks  

Science Conference Proceedings (OSTI)

This document addresses the preferred combination of design and operational configurations to provide heat removal from high-level waste tanks during Phase 1 waste feed delivery to prevent the waste temperature from exceeding tank safety requirement limits. An interim decision for the preferred method to remove the heat from the high-level waste tanks during waste feed delivery operations is presented herein.

WILLIS, W.L.

2000-06-15T23:59:59.000Z

335

Study on structure heat capacity of high-rise residences: (part 2) comparison by insulation methods  

Science Conference Proceedings (OSTI)

This paper follows the paper of Part 1. Here we examined Air-Conditioning loads (hereinafter referred to as AC loads) impact in several deferent cases of insulation methods in interior of super high-rise residences by using the dynamic simulation software ... Keywords: AC load, heat capacity, heat insulation method, high-rise residences, simulation

Yupeng Wang; Hiroatsu Fukuda; Akihiro Mitsumoto; Akihito Ozaki; Yuko Kuma

2007-08-01T23:59:59.000Z

336

Flame stabilization by a plasma driven radical jet in a high speed flow .  

E-Print Network (OSTI)

??In current afterburners combustion is stabilized by the high temperature, recirculating region behind bluff body flame holders, such as V-gutters. Blocking the high speed flow… (more)

Choi, Woong-Sik

2009-01-01T23:59:59.000Z

337

Cooling of X-ray Emitting Gas by Heat Conduction in the Center of Cooling Flow Clusters  

E-Print Network (OSTI)

We study the possibility that a large fraction of the gas at temperatures of ? 10 7 K in cooling flow clusters cools by heat conduction to lower temperatures, rather than by radiative cooling. We argue that this process, when incorporated into the so-called “moderate cooling flow model”, where the effective age of the intracluster medium is much lower than the age of the cluster, reduces substantially the expected X-ray luminosity from gas residing at temperatures of ? 10 7 K. In this model, the radiative mass cooling rate of gas at ? 10 7 K inferred from X-ray observations, which is heat conduction is regulated by reconnection between the magnetic field lines in cold ( ? 10 4 K) clouds and the field lines in the intracluster medium. A narrow conduction front is formed, which, despite the relatively low temperature, allows efficient heat conduction from the hot ICM to the cold clouds. The reconnection between the field lines in cold clouds and those in the intracluster medium occurs only when the magnetic field in the ICM is strong enough. This occurs only in the very inner regions of cooling flow clusters, at r ? 10 ? 30 kpc. The large ratio of the number of H? photons to the number of cooling hydrogen atoms is explained by this scenario. 1.

Noam Soker; L. Blanton; Craig L. Sarazin; Chandra Fellow

2003-01-01T23:59:59.000Z

338

High Rayleigh number thermal convection in volumetrically heated spherical shells  

E-Print Network (OSTI)

parameterizations for the average temperature of the shell and for the temperature jump across the thermal boundary properties, cores and overlying shells (e.g., silicate mantles or ice layers) of rocky planets and icy moons, including the rheology of the material, the presence of phase transitions, and the mode of heating

Tackley, Paul J.

339

High temperature thermographic measurements of laser heated silica  

SciTech Connect

In situ spatial and temporal surface temperature profiles of CO{sub 2} laser-heated silica were obtained using a long wave infrared (LWIR) HgCdTe camera. Solutions to the linear diffusion equation with volumetric and surface heating are shown to describe the temperature evolution for a range of beam powers, over which the peak surface temperature scales linearly with power. These solutions were used with on-axis steady state and transient experimental temperatures to extract thermal diffusivity and conductivity for a variety of materials, including silica, spinel, sapphire, and lithium fluoride. Experimentally-derived thermal properties agreed well with reported values and, for silica, thermal conductivity and diffusivity are shown to be approximately independent of temperature between 300 and 2800K. While for silica our analysis based on a temperature independent thermal conductivity is shown to be accurate, for other materials studied this treatment yields effective thermal properties that represent reasonable approximations for laser heating. Implementation of a single-wavelength radiation measurement in the semi-transparent regime is generally discussed, and estimates of the apparent temperature deviation from the actual outer surface temperature are also presented. The experimental approach and the simple analysis presented yield surface temperature measurements that can be used to validate more complex physical models, help discriminate dominant heat transport mechanisms, and to predict temperature distribution and evolution during laser-based material processing.

Elhadj, S; Yang, S T; Matthews, M J; Cooke, D J; Bude, J D; Johnson, M; Feit, M; Draggoo, V; Bisson, S E

2009-11-02T23:59:59.000Z

340

DevoFlow: scaling flow management for high-performance networks  

Science Conference Proceedings (OSTI)

OpenFlow is a great concept, but its original design imposes excessive overheads. It can simplify network and traffic management in enterprise and data center environments, because it enables flow-level control over Ethernet switching and provides global ... Keywords: data center, flow-based networking, switch design

Andrew R. Curtis; Jeffrey C. Mogul; Jean Tourrilhes; Praveen Yalagandula; Puneet Sharma; Sujata Banerjee

2011-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

High volume tidal or current flow harnessing system  

Science Conference Proceedings (OSTI)

Apparatus permitting the utilization of large volumes of water in the harnessing and extracting of a portion of the power generated by the rise and fall of ocean tides, ocean currents, or flowing rivers includes the provision of a dam, and a specialized single cavity chamber of limited size as compared with the water head enclosed by the dam, and an extremely high volume gating system in which all or nearly all of the water between the high and low levels on either side of the dam is cyclically gated through the single chamber from one side of the dam to the other so as to alternately provide positive air pressure and a partial vacuum within the single chamber. In one embodiment, the specialized chamber has a barrier at the bottom which divides the bottom of the chamber in half, large ports at the bottom of the chamber to permit inflow and outflow of high volumes of water, and ganged structures having a higher total area than that of corresponding ports, in which the structures form sluice gates to selectively seal off and open different sets of ports. In another embodiment, a single chamber is used without a barrier. In this embodiment, vertical sluice gates are used which may be activated automatically by pressures acting on the sluice gates as a result of ingested and expelled water.

Gorlov, A.M.

1984-08-07T23:59:59.000Z

342

Application of mechanistic models for flow distribution and heat transfer in finned tube bundles.  

E-Print Network (OSTI)

?? The focus of this thesis was heat transfer and pressure drop in staggered tube bundles with solid and serrated fins. The first part of… (more)

Eikill, Astrid Oygarden

2013-01-01T23:59:59.000Z

343

Definition: Heat | Open Energy Information  

Open Energy Info (EERE)

Heat Heat Jump to: navigation, search Dictionary.png Heat Heat is the form of energy that is transferred between systems or objects with different temperatures (flowing from the high-temperature system to the low-temperature system). Also referred to as heat energy or thermal energy. Heat is typically measured in Btu, calories or joules. Heat flow, or the rate at which heat is transferred between systems, has the same units as power: energy per unit time (J/s).[1][2][3][4] View on Wikipedia Wikipedia Definition In physics and chemistry, heat is energy in transfer between a system and its surroundings other than by work or transfer of matter. The transfer can occur in two simple ways, conduction, and radiation, and in a more complicated way called convective circulation. Heat is not a property

344

Delivering High Reliability in Heat Recovery Steam Generators  

Science Conference Proceedings (OSTI)

Despite being relatively new, the worldwide fleet of combined-cycle units with heat recovery steam generators (HRSGs) has exhibited a disappointing record with respect to reliability and availability in terms of HRSG tube failures (HTFs). This report identifies actions that—if implemented prior to commercial operation—should greatly improve the operational HRSG reliability.BackgroundWhen contemplating new combined-cycle units, the choices that can ...

2012-12-12T23:59:59.000Z

345

Definition: Heat pump | Open Energy Information  

Open Energy Info (EERE)

pump pump Jump to: navigation, search Dictionary.png Heat pump Heating and/or cooling equipment that, during the heating season, draws heat into a building from outside and, during the cooling season, ejects heat from the building to the outside[1] View on Wikipedia Wikipedia Definition A heat pump is a device that transfers heat energy from a heat source to a heat sink against a temperature gradient. Heat pumps are designed to move thermal energy opposite the direction of spontaneous heat flow. A heat pump uses some amount of external high-grade energy to accomplish the desired transfer of thermal energy from heat source to heat sink. While compressor-driven air conditioners and freezers are familiar examples of heat pumps, the term "heat pump" is more general and applies to

346

Design and demonstration of a high-temperature, deployable, membrane heat-pipe radiator element  

SciTech Connect

Demonstration of a high-temperature, deployable, membrane heat-pipe radiator element has been conducted. Membrane heat pipes offer the potential for compact storage, ease of transportation, self-deployment, and a high specific radiator performance (kg/kW) for use in thermal reflection systems of space nuclear power plants. A demonstration heat pipe 8-cm wide and 100-cm long was fabricated. The heat pipe containment and wick structure were made of stainless steel and sodium used as the working fluid. The tests demonstrated passive deployment of the high-temperature membrane radiator, simulating a single segment in a flat array, at a temperature of 800 K. Details of test procedures and results of the tests are presented in this paper together with a discussion of the design and development of a full-scale, segmented high-temperature, deployable membrane heat pipe. 5 refs., 7 figs.

Trujillo, V.L.; Keddy, E.S.; Merrigan, M.A.

1989-01-01T23:59:59.000Z

347

Use of a Heat Flow Meter to Determine Active PCM Content in an Insulation  

DOE Green Energy (OSTI)

Residential and commercial roofs and walls are currently designed and tested using steady-state criteria. The resulting R-values, based on the apparent thermal conductivity, are used by building standards as an important measure of energy performance. Building envelope components, however, are subject to dynamic environmental conditions. This mismatch between the steady-state principles used in design and code requirements and their dynamic operation results in relatively low thermal efficiencies. Although several research centers have developed experimental methods for transient analysis of building envelopes, there are no standardized testing procedures available for screening materials and systems for which performance depends on dynamic response. For example, a full-scale dynamic evaluation of phase change materials (PCMs) is needed to assess their energy saving benefits. A nationally accepted small-scale (one to two foot size specimens) testing procedure is not available for the analysis of dynamic thermal characteristics of conventional thermal mass systems or PCM-enhanced materials. At the same time, data on these characteristics are necessary for whole-building simulations, energy analysis, and energy code work. The transient characteristics of PCM-enhanced products depend on the PCM content and quality. The only readily available method of thermal evaluation uses the differential scanning calorimeter. Unfortunately, this method requires small, relatively uniform test specimens. This requirement is unrealistic in the case of PCM-enhanced building envelope products such as PCM-cellulose, PCM-glass fiber, or PCM-gypsum blends. Small specimens are not representative of PCM-based blends, since these materials are not homogeneous. Jan Kosny and David Yarbrough, Oak Ridge National Laboratory, P.O. Box 2008, MS 6070, Oak Ridge, TN 37831-6070. Elizabeth Kossecka, Polish Academy of Sciences, Institute of Fundamental Technological Research, Pawinskiego 5 B, 02-106, Warsaw, Poland. A procedure for making dynamic heat-flow measurements using existing instrumentation has been developed to analyze the benefits of thermal storage. This small-scale testing method is useful for thermal analysis and as a potential quality control method for producers of PCM-enhanced building materials. The research may provide the basis for consensus standard development. This paper uses as an example a dynamic testing process for PCM-enhanced cellulose insulation.

Kosny, Jan [ORNL; Kossecka, Elizabeth [Institute of Fundamental Technological Research, Polish Academy of Sciences; Yarbrough, David W [ORNL

2010-01-01T23:59:59.000Z

348

A Linear Model Study of Cross-Equatorial Flow Forced by Summer Monsoon Heat Sources  

Science Conference Proceedings (OSTI)

A linear model of the steady response of a stratified fluid to isolated heat sources on a sphere is developed. The model is used to examine the response to diabatic heating associated with summer monsoon precipitation in India and to low-level ...

Keith D. Sashegyi; John E. Geisler

1987-07-01T23:59:59.000Z

349

Interaction between an Inland Urban Heat Island and a Sea-Breeze Flow: A Laboratory Study  

Science Conference Proceedings (OSTI)

Using laboratory experimental data taken from a temperature-controlled water tank, the basic features of the circulation associated with an inland urban heat island (UHI) of diameter D and surface heating rate H0 and its interaction with a sea-...

A. Cenedese; P. Monti

2003-11-01T23:59:59.000Z

350

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

351

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

352

System for Recovering Waste Heat from High Temperature Molten ...  

Science Conference Proceedings (OSTI)

There are some shortages: poor effectiveness of granulation, high air-slag ratio and high energy consumption, which are the obstacles to popularize ...

353

Parametric Analyses of Heat Removal from High Level Waste Tanks  

Science Conference Proceedings (OSTI)

The general thermal hydraulics program GOTH-SNF was used to predict the thermal response of the waste in tanks 241-AY-102 and 241-AZ-102 when mixed by two 300 horsepower mixer pumps. This mixing was defined in terms of a specific waste retrieval scenario. Both dome and annulus ventilation system flow are necessary to maintain the waste within temperature control limits during the mixing operation and later during the sludge-settling portion of the scenario are defined.

TRUITT, J.B.

2000-06-05T23:59:59.000Z

354

A Stable Vanadium Redox-Flow Battery with High Energy Density for Large-scale Energy Storage  

SciTech Connect

Low cost, high performance redox flow batteries are highly demanded for up to multi-megawatt levels of renewable and grid energy storage. Here, we report a new vanadium redox flow battery with a significant improvement over the current technologies. This new battery utilizes a sulfate-chloride mixed solution, which is capable of dissolving more than 2.5 M vanadium or about a 70% increase in the energy storage capacity over the current vanadium sulfate system. More importantly, the new electrolyte remains stable over a wide temperature range of -5 to 60oC, potentially eliminating the need of active heat management. Its high energy density, broad operational temperature window, and excellent electrochemical performance would lead to a significant reduction in the cost of energy storage, thus accelerating its market penetration.

Li, Liyu; Kim, Soowhan; Wang, Wei; Vijayakumar, M.; Nie, Zimin; Chen, Baowei; Zhang, Jianlu; Xia, Guanguang; Hu, Jian Z.; Graff, Gordon L.; Liu, Jun; Yang, Zhenguo

2011-05-01T23:59:59.000Z

355

Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems  

E-Print Network (OSTI)

comparison of VAV and VRF air conditioning systems in anThe variable refrigerant flow (VRF) and ground source heatthe energy efficiency of VRF systems compared with GSHP

Hong, Tainzhen

2010-01-01T23:59:59.000Z

356

High Temperature Variable Conductance Heat Pipes for Radioisotope Stirling Systems  

SciTech Connect

In a Stirling radioisotope system, heat must continually be removed from the GPHS modules, to maintain the GPHS modules and surrounding insulation at acceptable temperatures. Normally, the Stirling converter provides this cooling. If the Stirling engine stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS, but also ending the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) is under development to allow multiple stops and restarts of the Stirling engine. The status of the ongoing effort in developing this technology is presented in this paper. An earlier, preliminary design had a radiator outside the Advanced Stirling Radioisotope Generator (ASRG) casing, used NaK as the working fluid, and had the reservoir located on the cold side adapter flange. The revised design has an internal radiator inside the casing, with the reservoir embedded inside the insulation. A large set of advantages are offered by this new design. In addition to reducing the overall size and mass of the VCHP, simplicity, compactness and easiness in assembling the VCHP with the ASRG are significantly enhanced. Also, the permanently elevated temperatures of the entire VCHP allows the change of the working fluid from a binary compound (NaK) to single compound (Na). The latter, by its properties, allows higher performance and further mass reduction of the system. Preliminary design and analysis shows an acceptable peak temperature of the ASRG case of 140 deg. C while the heat losses caused by the addition of the VCHP are 1.8 W.

Tarau, Calin; Walker, Kara L.; Anderson, William G. [Advanced Cooling Technologies, Inc. 1046 New Holland Ave. Lancaster, PA 17601 (United States)

2009-03-16T23:59:59.000Z

357

Heat Recovery from Coal Gasifiers  

E-Print Network (OSTI)

This paper deals with heat recovery from pressurized entrained and fixed bed coal gasifiers for steam generation. High temperature waste heat, from slagging entrained flow coal gasifier, can be recovered effectively in a series of radiant and convection waste heat boilers. Medium level waste heat leaving fixed bed type gasifiers can be recovered more economically by convection type boilers or shell and tube heat exchangers. An economic analysis for the steam generation and process heat exchanger is presented. Steam generated from the waste heat boiler is used to drive steam turbines for power generation or air compressors for the oxygen plant. Low level heat recovered by process heat exchangers is used to heat product gas or support the energy requirement of the gasification plant. The mechanical design for pressure vessel shell and boiler tubes is discussed. The design considers metallurgical requirements associated with hydrogen rich, high temperature, and high pressure atmosphere.

Wen, H.; Lou, S. C.

1981-01-01T23:59:59.000Z

358

Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD  

SciTech Connect

This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

2010-03-15T23:59:59.000Z

359

Pacific Ocean Heat Transport at 24°N in a High-Resolution Global Model  

Science Conference Proceedings (OSTI)

Meridional heat transport in the North Pacific Ocean in a seasonally forced high-resolution global ocean general circulation model is compared to observations. At 24°N, annual mean heat transport in the model of 0.37×1011W is half the most recent ...

John L. Wilkin; James V. Mansbridge; J. Stuart Godfrey

1995-10-01T23:59:59.000Z

360

Precision control of high temperature furnaces using an auxiliary power supply and charged particle current flow  

DOE Patents (OSTI)

Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. 5 figs.

Pollock, G.G.

1997-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Precision control of high temperature furnaces using an auxiliary power supply and charged practice current flow  

DOE Patents (OSTI)

Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved.

Pollock, George G. (San Ramon, CA)

1997-01-01T23:59:59.000Z

362

Stochastic Heating, Differential Flow, and the Alpha-to-Proton Temperature Ratio in the Solar Wind  

E-Print Network (OSTI)

We extend previous theories of stochastic ion heating to account for the motion of ions along the magnetic field. We derive an analytic expression for the ion-to-proton perpendicular temperature ratio in the solar wind for any ion species, assuming that stochastic heating is the dominant ion heating mechanism. This expression describes how this temperature ratio depends upon the average velocity of the ions along the magnetic field direction and the ratio of the parallel proton pressure to the magnetic pressure. We compare our model with previously published measurements of alpha particles and protons from the WIND spacecraft. We find that stochastic heating offers a promising explanation for these measurements when the fractional cross helicity and Alfven ratio at the proton-gyroradius scale have values that are broadly consistent with solar-wind measurements.

Chandran, B D G; Quataert, E; Kasper, J C; Isenberg, P A; Bourouaine, S

2013-01-01T23:59:59.000Z

363

The flow structure under mixed convection in a uniformly heated vertical pipe  

E-Print Network (OSTI)

For decay heat removal systems in the conceptual Gas-cooled Fast Reactor (GFR) currently under development, passive emergency cooling using natural circulation of a gas at an elevated pressure is being considered. Since ...

Lee, Jeongik

2005-01-01T23:59:59.000Z

364

Study of Linear Steady Atmospheric Flow above a Finite Surface Heating  

Science Conference Proceedings (OSTI)

The steady-state atmospheric responses to a finite surface heating through thermal eddy diffusion are studied. The effects of the mean wind, the earth's rotation, and the thermal stratification are considered in a linear system. Scale analysis ...

Hsiao-Ming Hsu

1987-01-01T23:59:59.000Z

365

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance  

Science Conference Proceedings (OSTI)

The eddy heat flux generated by statistically equilibrated baroclinic turbulence supported on a uniform, horizontal temperature gradient is examined using a two-layer ?-plane quasigeostrophic model. The dependence of the eddy diffusivity of ...

Andrew F. Thompson; William R. Young

2007-09-01T23:59:59.000Z

366

Alumina Nanoparticle Pre-coated Tubing Ehancing Subcooled Flow Boiling Cricital Heat Flux  

E-Print Network (OSTI)

Nanofluids are engineered colloidal dispersions of nano-sized particle in common base fluids. Previous pool boiling studies have shown that nanofluids can improve critical heat flux (CHF) up to 200% for pool boiling and ...

Truong, Bao H.

367

High temperature superconducting current lead test facility with heat pipe intercepts  

SciTech Connect

A high temperature superconducting (HTS) current lead test facility using heat pipe thermal intercepts is under development at the Superconducting Technology Center at Los Alamos National Laboratory. The facility can be configured for tests at currents up to 1,000 A. Mechanical cryocoolers provide refrigeration to the leads. Electrical isolation is maintained by intercepting thermal energy from the leads through cryogenic heat pipes. HST lead warm end temperature is variable from 65 K to over 90 K by controlling heat pipe evaporator temperature. Cold end temperature is variable up to 30 K. Performance predictions in terms of heat pipe evaporator temperature as a function of lead current are presented for the initial facility configuration, which supports testing up to 200 A. Measurements are to include temperature and voltage gradient in the conventional and HTS lead sections, temperature and heat transfer rate in the heat pipes. as well as optimum and off-optimum performance of the conventional lead sections.

Blumenfeld, P.E.; Prenger, C.; Roth, E.W.; Stewart, J.A.

1998-12-31T23:59:59.000Z

368

Flow Behavior of Three 625-Type Alloys During High Temperature ...  

Science Conference Proceedings (OSTI)

heat exchangers, and piping. The alloy ..... H.H. Ruble and S.L. Semiatin, Metal;s Handbook Ninth Edition (Metals Park, OH: ASM. International, 1988), 261-266.

369

Heat transfer in leading and trailing edge cooling channels of the gas turbine blade under high rotation numbers  

E-Print Network (OSTI)

The gas turbine blade/vane internal cooling is achieved by circulating the compressed air through the cooling passages inside the turbine blade. Leading edge and trailing edge of the turbine blade are two critical regions which need to be properly cooled. Leading edge region receives extremely hot mainstream flow and high heat transfer enhancement is required. Trailing edge region usually has narrow shaped geometry and applicable cooling techniques are restricted. Heat transfer will be investigated in the leading edge and trailing edge cooling channels at high rotation numbers close to the engine condition. Heat transfer and pressure drop has been investigated in an equilateral triangular channel (Dh=1.83cm) to simulate the cooling channel near the leading edge of the gas turbine blade. Three different rib configurations (45°, inverted 45°, and 90°) were tested at four different Reynolds numbers (10000-40000), each with five different rotational speeds (0-400 rpm). By varying the Reynolds numbers (10000-40000) and the rotational speeds (0-400 rpm), the rotation number and buoyancy parameter reached in this study were 0-0.58 and 0-2.3, respectively. 45° angled ribs show the highest thermal performance at stationary condition. 90° ribs have the highest thermal performance at the highest rotation number of 0.58. Heat transfer coefficients are also experimentally measured in a wedge-shaped cooling channel (Dh =2.22cm, Ac=7.62cm2) to model an internal cooling passage near the trailing edge of a gas turbine blade where the coolant discharges through the slot to the mainstream flow. Tapered ribs are put on the leading and trailing surfaces with an angle of attack of 45°. The ribs are parallel with staggered arrangement on opposite walls. The inlet Reynolds number of the coolant varies from 10,000 to 40,000 and the rotational speeds varies from 0 to 500 rpm. The inlet rotation number is from 0 - 1.0. The local rotation number and buoyancy parameter are determined by the rotational speeds and the local Reynolds number at each region. Results show that heat transfer is high near the regions where strong slot ejection exists. Both the rotation number and buoyancy parameter have been correlated to predict the rotational heat transfer enhancement.

Liu, Yao-Hsien

2008-12-01T23:59:59.000Z

370

Effect of flow topology on the calculation of two-phase frictional multipliers in uniformly heated flow of R-134a in a rectangular duct  

SciTech Connect

The two-phase frictional multipliers for SUVA R-134a flowing in a rectangular duct (with D{sub H} = 4.8 mm) have been measured for three nominal system pressures (0.88, 1.34 and 2.34 MPa) and four nominal mass fluxes (510, 1020 and 1740, 2040 kg/m{sup 2}/s) under uniform heat flux conditions. The data is compared with adiabatic data previously taken at similar flow conditions, as well as with several classical multiplier correlations. The comparisons reveal a strong effect of pressure and mass flux on the flow topology and, by extension, a large effect on the calculation of acceleration and frictional pressure drop components. For this fluid and this geometry, entrainment and fluid separation is enhanced at higher pressures and mass flux such that most of the liquid exists in the test section edges and as dispersed droplets in the core. For these cases, the classical simplified approach to calculate acceleration pressure drop fails to adequately predict the acceleration component and leads to erroneous calculations of frictional pressure drop from the measured total pressure drop. Best estimates of the true acceleration component are given, based on void profiles measured with a gamma densitometer system, comparisons to the adiabatic data, and recasting the data in terms of the total pressure drop multiplier as a function of the Martinelli parameter, X{sub tt}. (author)

Vassallo, Peter; Kevin Cope, W.; Smith, Walter C. [Bechtel Marine Propulsion Corporation, Niskayuna, NY 12309 (United States)

2010-11-15T23:59:59.000Z

371

Double-diffusive convection for a non-Newtonian fluid flow past a permeable surface embedded in a porous medium with uniform heat and mass fluxes  

Science Conference Proceedings (OSTI)

The problem of steady, laminar, double-diffusive mixed convective flow of a non-Newtonian power-law fluid past a vertical semi-infinite permeable surface embedded in a porous medium with uniform heat and mass fluxes. A mixed convection parameter for ... Keywords: heat and mass transfer, mixed convection, non-Newtonian fluid, numerical solution, porous media, suction or injection

Ali J. Chamkha

2008-03-01T23:59:59.000Z

372

Development and extended operation of a high power radiation loaded heat pipe  

SciTech Connect

A high temperature, high power molybdenum-lithium heat pipe has been fabricated and tested at 1500 K for 1700 hours with radiant heat rejection. Power throughput during the test was approximately 14 kW, corresponding to an axial flux density of 11 kW/cm/sup 2/ for the 1.59 cm diameter heat pipe. Radial flux density was 70 W/cm/sup 2/ over an evaporator length of 40.0 cm. Condenser length was approximately 150 cm with radiant heat rejection from the condenser to a coaxial water cooled radiation calorimeter. A plasma sprayed, high emissivity coating was used on the condenser surface to increase the radiant heat rejection during the tests. The heat pipe was operated for 514 hours at steady state conditions before being damaged during a planned shutdown for test equipment maintenance. The damage was repaired and the initial 1000 hour test period completed without further incident. After physical examination of the heat pipe at 1000 hours the test was resumed and the heat pipe operated at the same conditions for an additional 700 hours before conclusion of this test phase.

Merrigan, M.A.; Keddy, E.S.; Runyan, J.R.; Martinez, H.E.

1984-06-01T23:59:59.000Z

373

High energy bursts from a solid state laser operated in the heat capacity limited regime  

DOE Patents (OSTI)

High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes.

Albrecht, Georg (Livermore, CA); George, E. Victor (Livermore, CA); Krupke, William F. (Pleasanton, CA); Sooy, Walter (Pleasanton, CA); Sutton, Steven B. (Manteca, CA)

1996-01-01T23:59:59.000Z

374

High energy bursts from a solid state laser operated in the heat capacity limited regime  

DOE Patents (OSTI)

High energy bursts are produced from a solid state laser operated in a heat capacity limited regime. Instead of cooling the laser, the active medium is thermally well isolated. As a result, the active medium will heat up until it reaches some maximum acceptable temperature. The waste heat is stored in the active medium itself. Therefore, the amount of energy the laser can put out during operation is proportional to its mass, the heat capacity of the active medium, and the temperature difference over which it is being operated. The high energy burst capacity of a heat capacity operated solid state laser, together with the absence of a heavy, power consuming steady state cooling system for the active medium, will make a variety of applications possible. Alternately, cooling takes place during a separate sequence when the laser is not operating. Industrial applications include new material working processes. 5 figs.

Albrecht, G.; George, E.V.; Krupke, W.F.; Sooy, W.; Sutton, S.B.

1996-06-11T23:59:59.000Z

375

Low Cost High Performance Generator Technology Program. Volume 5. Heat Pipe Topical  

DOE Green Energy (OSTI)

Research progress towards the development of a heat pipe for use in the Low Cost High Performance Thermoelectric Generator Program is reported for the period May 15, 1975 through June 1975. (TFD)

Not Available

1975-07-01T23:59:59.000Z

376

Development and Analysis of Advanced High-Temperature Technology for Nuclear Heat Transport and Power Conversion  

DOE Green Energy (OSTI)

This project by the Thermal Hydraulics Research Laboratory at U.C. Berkeley Studied advanced high-temperature heat transport and power conversion technology, in support of the Nuclear Hydrogen Initiative and Generation IV.

Per F. Peterson

2010-03-01T23:59:59.000Z

377

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

in Porous Media," SAND84-2057, Sandia National Laboratories,and Field Comparison of the Sandia . Waste-Isolation FlowNUREG/CR-3316, SAND83- 1154, Sandia National Laboratories,

Moridis, G.J.

2010-01-01T23:59:59.000Z

378

Development of Micro/Nano-Scale Sensors for Investigation of Heat Transfer in Multi-Phase Flows  

E-Print Network (OSTI)

The objective of this investigation was to develop micro/nano-scale temperature sensors for measuring surface temperature transients in multi-phase flows and heat transfer. Surface temperature fluctuations were measured on substrates exposed to phase change processes. Prior reports in the literature indicate that these miniature scale surface temperature fluctuations can result in 60-90 percent of the total heat flux during phase change heat transfer. In this study, DTS (Diode Temperature Sensors) were fabricated with a doping depth of ~100 nm on n-type silicon to measure the surface temperature transients on a substrate exposed to droplet impingement cooling. DTS are expected to have better sensor characteristics compared to TFTs (Thin Film Thermocouples), due to their small size and faster response (which comes at the expense of the smaller operating temperature range). Additional advantages of DTS include the availability of robust commercial micro fabrication processes (with diode and transistor node sizes currently in the size range of ~ 30 nm), and that only 2N wire leads can be used to interrogate a set of N x N array of sensors (in contrast thermocouples require 2 N x N wire leads for N x N sensor array). The DTS array was fabricated using conventional semi-conductor processes. The temperature response of the TFT and DTS was also calibrated using NIST standards. Transient temperature response of the DTS was recorded using droplet impingement cooling experiments. The droplet impingement cooling experiments were performed for two different test fluids (acetone and ethanol). An infrared camera was used to verify the surface temperature of the substrate and compare these measurements with the temperature values recorded by individual DTS. PVD (Physical Vapor Deposition) was used for obtaining the catalyst coatings for subsequent CNT synthesis using CVD (Chemical Vapor Deposition) as well as for fabricating the thin film thermocouple (TFT) arrays using the "lift-off" process. Flow boiling experiments were conducted for three different substrates. Flow boiling experiments on bare silicon wafer surface were treated as the control experiment, and the results were compared with that of CNT (Carbon Nano-Tube) coated silicon wafer surfaces. Similar experiments were also performed on a pure copper surface. In addition, experiments were performed using compact condensers. Micro-scale patterns fabricated on the refrigerant side of the compact heat exchanger were observed to cause significant enhancement of the condensation heat transfer coefficient.

Jeon, Sae Il

2011-08-01T23:59:59.000Z

379

High Performance Computing Based Methods for Simulation and Optimisation of Flow Problems.  

E-Print Network (OSTI)

??The thesis is concerned with the study of methods in high-performance computing for simulation and optimisation of flow problems that occur in the framework of… (more)

Bockelmann, Hendryk

2010-01-01T23:59:59.000Z

380

Coronal Heating and Acceleration of the High/Low-Speed Solar Wind by Fast/Slow MHD Shock Trains  

E-Print Network (OSTI)

We investigate coronal heating and acceleration of the high- and low-speed solar wind in the open field region by dissipation of fast and slow magnetohydrodynamical (MHD) waves through MHD shocks. Linearly polarized \\Alfven (fast MHD) waves and acoustic (slow MHD) waves travelling upwardly along with a magnetic field line eventually form fast switch-on shock trains and hydrodynamical shock trains (N-waves) respectively to heat and accelerate the plasma. We determine one dimensional structure of the corona from the bottom of the transition region (TR) to 1AU under the steady-state condition by solving evolutionary equations for the shock amplitudes simultaneously with the momentum and proton/electron energy equations. Our model reproduces the overall trend of the high-speed wind from the polar holes and the low-speed wind from the mid- to low-latitude streamer except the observed hot corona in the streamer. The heating from the slow waves is effective in the low corona to increase the density there, and plays an important role in the formation of the dense low-speed wind. On the other hand, the fast waves can carry a sizable energy to the upper level to heat the outer corona and accelerate the high-speed wind effectively. We also study dependency on field strength, $B_0$, at the bottom of the TR and non-radial expansion of a flow tube, $f_{\\rm max}$, to find that large $B_0/f_{\\rm max}\\gtrsim 2$ but small $B_0\\simeq 2$G are favorable for the high-speed wind and that small $B_0/f_{\\rm max}\\simeq 1$ is required for the low-speed wind.

Takeru K. Suzuki

2003-12-22T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Northern High-Latitude Heat Budget Decomposition and Transient Warming  

Science Conference Proceedings (OSTI)

Climate models simulate a wide range of climate changes at high northern latitudes in response to increased CO2. They also have substantial disagreement on projected changes of the Atlantic meridional overturning circulation (AMOC). Here, two ...

Maria A. A. Rugenstein; Michael Winton; Ronald J. Stouffer; Stephen M. Griffies; Robert Hallberg

2013-01-01T23:59:59.000Z

382

Sensitivity studies of heat transfer: forced convection across a cylindrical pipe and duct flow  

E-Print Network (OSTI)

We consider two common heat transfer processes and perform a through sensitivity study of the variables involved. We derive and discuss analytical formulas for the heat transfer coefficient in function of film velocity, air temperature and pipe diameter. The according plots relate to a qualitative analysis of the multi-variable function $h$, according to functional optimization. For each process, we provide with graphs and tables of the parameters of interest, such as the Reynolds number. This method of study and the specific values can constitute a useful reference for didactic purposes.

Ferrantelli, Andrea; Viljanen, Martti

2013-01-01T23:59:59.000Z

383

Water-heating dehumidifier  

DOE Patents (OSTI)

A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator fan. The condenser includes a water inlet and a water outlet for flowing water therethrough or proximate thereto, or is affixed to the tank or immersed into the tank to effect water heating without flowing water. The immersed condenser design includes a self-insulated capillary tube expansion device for simplicity and high efficiency. In a water heating mode air is drawn by the evaporator fan across the evaporator to produce cooled and dehumidified air and heat taken from the air is absorbed by the refrigerant at the evaporator and is pumped to the condenser, where water is heated. When the tank of water heater is full of hot water or a humidistat set point is reached, the water-heating dehumidifier can switch to run as a dehumidifier.

Tomlinson, John J. (Knoxville, TN)

2006-04-18T23:59:59.000Z

384

High Water Heating Bills on Lockdown at Idaho Jail | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

High Water Heating Bills on Lockdown at Idaho Jail High Water Heating Bills on Lockdown at Idaho Jail High Water Heating Bills on Lockdown at Idaho Jail August 19, 2010 - 12:05pm Addthis The Blaine County Public Safety Facility houses between 60 and 80 prisoners and roughly 30 staffers. | Photo courtesy of Blaine The Blaine County Public Safety Facility houses between 60 and 80 prisoners and roughly 30 staffers. | Photo courtesy of Blaine Lindsay Gsell What does this project do? The new solar thermal hot water system will provide nearly 70 percent of the BTUs required for heating 600,000 gallons of water for the jail annually, saving the county more than $4,000 a year in electricity costs at current rates. In Hailey, Idaho, one 330,000 square foot building - the Blaine County Public Safety Facility - accounts for the county's highest operational

385

HEATS OF COMBUSTION OF HIGH TEMPERATURE POLYMERS Richard N. Walters*, Stacey M. Hackett* and Richard E. Lyon  

E-Print Network (OSTI)

1 HEATS OF COMBUSTION OF HIGH TEMPERATURE POLYMERS Richard N. Walters*, Stacey M. Hackett Creek Avenue, Building C Egg Harbor Township, New Jersey 08234 ABSTRACT The heats of combustion to thermochemical calculations of the net heat of combustion from oxygen consumption and the gross heat

Laughlin, Robert B.

386

The Role of Ekman flow and Planetary Waves in the Oceanic Cross-Equatorial Heat Transport  

Science Conference Proceedings (OSTI)

A numerical model is used to mechanistically simulate the oceans’ seasonal cross-equatorial heat transport, and the results of Oort and Vonder Haar (1976). The basic process of Ekman pumping and drift is found to be able to account for a large ...

Paul S. Schopf

1980-03-01T23:59:59.000Z

387

Tree-Shaped Fluid Flow and Heat Storage in a Conducting Solid  

Science Conference Proceedings (OSTI)

This paper documents the time-dependent thermal interaction between a fluid stream configured as a plane tree of varying complexity embedded in a conducting solid with finite volume and insulated boundaries. The time scales of the convection-conduction phenomenon are identified. Two-dimensional and three-dimensional configurations are simulated numerically. The number of length scales of the tree architecture varies from one to four. The results show that the heat transfer density increases, and the time of approach to equilibrium decreases as the complexity of the tree designs increases. These results are then formulated in the classical notation of energy storage by sensible heating, which shows that the effective number of heat transfer units increases as the complexity of the tree design increases. The complexity of heat transfer designs in many applications is constrained by first cost and operating cost considerations. This work provides a fundamental basis for objective evaluation of cost and performance tradeoffs in thermal design of energy systems with complexity as an unconstrained parameter that can be actively varied over a broad range to determine the optimum system design.

Combelles, L.; Lorente, S.; Anderson, R.; Bejan, A.

2012-01-01T23:59:59.000Z

388

Comparison of the PLTEMP code flow instability predictions with measurements made with electrically heated channels for the advanced test reactor.  

SciTech Connect

When the University of Missouri Research Reactor (MURR) was designed in the 1960s the potential for fuel element burnout by a phenomenon referred to at that time as 'autocatalytic vapor binding' was of serious concern. This type of burnout was observed to occur at power levels considerably lower than those that were known to cause critical heat flux. The conversion of the MURR from HEU fuel to LEU fuel will probably require significant design changes, such as changes in coolant channel thicknesses, that could affect the thermal-hydraulic behavior of the reactor core. Therefore, the redesign of the MURR to accommodate an LEU core must address the same issues of fuel element burnout that were of concern in the 1960s. The Advanced Test Reactor (ATR) was designed at about the same time as the MURR and had similar concerns with regard to fuel element burnout. These concerns were addressed in the ATR by two groups of thermal-hydraulic tests that employed electrically heated simulated fuel channels. The Croft (1964), Reference 1, tests were performed at ANL. The Waters (1966), Reference 2, tests were performed at Hanford Laboratories in Richland Washington. Since fuel element surface temperatures rise rapidly as burnout conditions are approached, channel surface temperatures were carefully monitored in these experiments. For self-protection, the experimental facilities were designed to cut off the electric power when rapidly increasing surface temperatures were detected. In both the ATR reactor and in the tests with electrically heated channels, the heated length of the fuel plate was 48 inches, which is about twice that of the MURR. Whittle and Forgan (1967) independently conducted tests with electrically heated rectangular channels that were similar to the tests by Croft and by Walters. In the Whittle and Forgan tests the heated length of the channel varied among the tests and was between 16 and 24 inches. Both Waters and Whittle and Forgan show that the cause of the fuel element burnout is due to a form of flow instability. Whittle and Forgan provide a formula that predicts when this flow instability will occur. This formula is included in the PLTEMP/ANL code.Error! Reference source not found. Olson has shown that the PLTEMP/ANL code accurately predicts the powers at which flow instability occurs in the Whittle and Forgan experiments. He also considered the electrically heated tests performed in the ANS Thermal-Hydraulic Test Loop at ORNL and report by M. Siman-Tov et al. The purpose of this memorandum is to demonstrate that the PLTEMP/ANL code accurately predicts the Croft and the Waters tests. This demonstration should provide sufficient confidence that the PLTEMP/ANL code can adequately predict the onset of flow instability for the converted MURR. The MURR core uses light water as a coolant, has a 24-inch active fuel length, downward flow in the core, and an average core velocity of about 7 m/s. The inlet temperature is about 50 C and the peak outlet is about 20 C higher than the inlet for reactor operation at 10 MW. The core pressures range from about 4 to about 5 bar. The peak heat flux is about 110 W/cm{sup 2}. Section 2 describes the mechanism that causes flow instability. Section 3 describes the Whittle and Forgan formula for flow instability. Section 4 briefly describes both the Croft and the Waters experiments. Section 5 describes the PLTEMP/ANL models. Section 6 compares the PLTEMP/ANL predictions based on the Whittle and Forgan formula with the Croft measurements. Section 7 does the same for the Waters measurements. Section 8 provides the range of parameters for the Whittle and Forgan tests. Section 9 discusses the results and provides conclusions. In conclusion, although there is no single test that by itself closely matches the limiting conditions in the MURR, the preponderance of measured data and the ability of the Whittle and Forgan correlation, as implemented in PLTEMP/ANL, to predict the onset of flow instability for these tests leads one to the conclusion that the same method should be able to predict the

Feldman, E. (Nuclear Engineering Division)

2011-06-09T23:59:59.000Z

389

Dynamic Heat Flow Measurements to Study the Distribution of Phase-Change Material in an Insulation Matrix  

DOE Green Energy (OSTI)

Phase change materials (PCMs) are used in building envelopes in many forms. The PCMs may be encased in discrete pouches or containers, or they may be distributed within another medium, such as in a board or within a loose fill product. In addition, most PCM products are blends containing fire retardants and chemical stabilizers. However, the current test method to measure the dynamic characteristics of PCMs, the differential scanning calorimeter (DSC), requires specimens that are relatively uniform and very small. Considering the limitations of DSC test results when applied to more complex PCM building envelope applications, we developed a combined experimental analytical protocol to determine the amount of phase-change energy actually available to provide thermal storage. This paper presents this new methodology for performing dynamic heat flow analysis of complex PCM-enhanced building materials. The experimental analytical protocol uses a conventional heat-flow apparatus and three-dimensional (3-D), finite-difference modeling. Based upon results from this methodology, ORNL researchers developed a simplified one-dimensional (1-D) model that can be easily used in whole-building simulations. This paper describes this methodology as applied to an insulation assembly containing a complex array of PCM pouches.

Kosny, Jan [ORNL; Stovall, Therese K [ORNL; Yarbrough, David W [ORNL

2010-01-01T23:59:59.000Z

390

High Operating Temperature Liquid Metal Heat Transfer Fluids (Fact Sheet)  

DOE Green Energy (OSTI)

The University of California, Los Angeles, the University of California, Berkeley, and Yale University is one of the 2012 SunShot CSP R&D awardees for their Multidisciplinary University Research Initiative (MURI): High Operating Temperature (HOT) Fluids. This fact sheet explains the motivation, description, and impact of the project.

Not Available

2012-12-01T23:59:59.000Z

391

Electrical heating of soils using high efficiency electrode patterns and power phases  

DOE Patents (OSTI)

Powerline-frequency electrical (joule) heating of soils using a high efficiency electrode configuration and power phase arrangement. The electrode configuration consists of several heating or current injection electrodes around the periphery of a volume of soil to be heated, all electrodes being connected to one phase of a multi-phase or a single-phase power system, and a return or extraction electrode or electrodes located inside the volume to be heated being connected to the remaining phases of the multi-phase power system or to the neutral side of the single-phase power source. This electrode configuration and power phase arrangement can be utilized anywhere where powerline frequency soil heating is applicable and thus has many potential uses including removal of volatile organic compounds such as gasoline and tricholorethylene (TCE) from contaminated areas.

Buettner, Harley M. (Livermore, CA)

1999-01-01T23:59:59.000Z

392

Device and method for relativistic electron beam heating of a high-density plasma to drive fast liners  

DOE Patents (OSTI)

A device and method for relativistic electron beam heating of a high-density plasma in a small localized region. A relativistic electron beam generator or accelerator produces a high-voltage electron beam which propagates along a vacuum drift tube and is modulated to initiate electron bunching within the beam. The beam is then directed through a low-density gas chamber which provides isolation between the vacuum modulator and the relativistic electron beam target. The relativistic beam is then applied to a high-density target plasma which typically comprises DT, DD, hydrogen boron or similar thermonuclear gas at a density of 10.sup.17 to 10.sup.20 electrons per cubic centimeter. The target gas is ionized prior to application of the electron beam by means of a laser or other preionization source to form a plasma. Utilizing a relativistic electron beam with an individual particle energy exceeding 3 MeV, classical scattering by relativistic electrons passing through isolation foils is negligible. As a result, relativistic streaming instabilities are initiated within the high-density target plasma causing the relativistic electron beam to efficiently deposit its energy and momentum into a small localized region of the high-density plasma target. Fast liners disposed in the high-density target plasma are explosively or ablatively driven to implosion by a heated annular plasma surrounding the fast liner which is generated by an annular relativistic electron beam. An azimuthal magnetic field produced by axial current flow in the annular plasma, causes the energy in the heated annular plasma to converge on the fast liner.

Thode, Lester E. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

393

Heating  

SciTech Connect

According to The Hydronics Institute, the surge in gas-fired boiler shipments brought about 3 years ago by high oil prices and the availability of natural gas after years of curtailment has almost competely subsided. Gas prices continue to escalate and the threat of decontrol by 1985 continues. Likewise, the Gas Appliance Manufacturers Association reports that shipments of gas-fired unit heaters, duct furnaces, and wall furnaces have also dropped as homeowners adopt a wait-and-see attitude toward conversion. However, the market for high- and ultra-high-efficiency furnaces appears to hold potential for expansion. Because of the rebounding home market, a steady replacement market, and increased sales for reasons of efficiency, GAMA expects the total (gas, oil, and electric) central furnace market to increase by 16% in 1983.

1983-04-04T23:59:59.000Z

394

UNSAT-H Version 3.0: Unsaturated Soil Water and Heat Flow Model Theory, User Manual, and Examples  

Science Conference Proceedings (OSTI)

The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water dynamics and estimating recharge rates, the UNSAT-H model addresses soil water infiltration, redistribution, evaporation, plant transpiration, deep drainage, and soil heat flow as one-dimensional processes. The UNSAT-H model simulates liquid water flow using Richards' equation (Richards 1931), water vapor diffusion using Fick's law, and sensible heat flow using the Fourier equation. This report documents UNSAT-H .Version 3.0. The report includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plants, and the code manual. Version 3.0 is an, enhanced-capability update of UNSAT-H Version 2.0 (Fayer and Jones 1990). New features include hysteresis, an iterative solution of head and temperature, an energy balance check, the modified Picard solution technique, additional hydraulic functions, multiple-year simulation capability, and general enhancements.

MJ Fayer

2000-06-12T23:59:59.000Z

395

Development of a High Performance Air Source Heat Pump for the US Market  

SciTech Connect

Heat pumps present a significant advantage over conventional residential heating technologies due to higher energy efficiencies and less dependence on imported oil. The US development of heat pumps dates back to the 1930 s with pilot units being commercially available in the 1950 s. Reliable and cost competitive units were available in the US market by the 1960 s. The 1973 oil embargo led to increased interest in heat pumps prompting significant research to improve performance, particularly for cold climate locations. Recent increasing concerns on building energy efficiency and environmental emissions have prompted a new wave of research in heat pump technology with special emphasis on reducing performance degradation at colder outdoor air temperatures. A summary of the advantages and limitations of several performance improvement options sought for the development of high performance air source heat pump systems for cold climate applications is the primary focus of this paper. Some recommendations for a high performance cold climate heat pump system design most suitable for the US market are presented.

Abdelaziz, Omar [ORNL; Shen, Bo [ORNL; Gao, Zhiming [ORNL; Baxter, Van D [ORNL; Iu, Ipseng [ORNL

2011-01-01T23:59:59.000Z

396

Compressor performance at high suction temperatures with application to solar heat pump  

DOE Green Energy (OSTI)

As part of the study of Solar Assisted Heat Pump (SAHP) Systems, the performance of the heat pump itself and its components under conditions attendant to series solar input to the evaporator is being investigated at Brookhaven National Laboratory (BNL). Particular emphasis has been placed on the details of the compressor performance, since in order to properly exploit the thermodynamic potential of high solar input temperatures (40 to 100/sup 0/F), the compressor must operate efficiently over a wide range of (saturated) suction temperatures most of which are well above those for which present compressors are designed. A systematic series of experiments is being conducted at evaporating temperatures in the range from 45 to 100/sup 0/F using a Solar Heat Pump Simulator and a specially designed Laboratory Model Heat Pump assembled from off-the-shelf components. Two reciprocating compressors have been tested thus far - an open type driven by a 2-speed motor and a hermetic 2-speed, the multi-speed feature providing capacity control, which is a virtual necessity for effective use of solar source. Thorough and highly accurate instrumentation is used in the simulator and in the heat pump refrigeration loop. The results to date of the compressor aspects of the solar heat pump experiments at BNL are described, and the general application of heat pumps and their compressors to use with solar input are discussed.

Kush, E A

1980-01-01T23:59:59.000Z

397

On Water Flow in Hot Fractured Rock -- A Sensitivity Study on the Impact of Fracture-Matrix Heat Transfer  

E-Print Network (OSTI)

is related to the heat transfer between the two phasespossibly be affected. Heat transfer from the matrix can beof Fracture-Matrix Heat Transfer Jens T. Birkholzer and

Birkholzer, Jens T.; Zhang, Yingqi

2005-01-01T23:59:59.000Z

398

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

transport, and heat transfer processes in porous media. 2.1.mass transport, and heat-transfer processes through porousinvolved. These heat-transfer processes are complicated by

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

399

Review of current status of high flux heat transfer techniques. Volume I. Text + Appendix A  

SciTech Connect

The scope of this work comprised two tasks. The first was to review high heat flux technology with consideration given to heat transfer panel configuration, diagnostics techniques and coolant supply. The second task was to prepare a report describing the findings of the review, to recommend the technology offering the least uncertainty for scale-up for the MFTF-B requirement and to recommend any new or perceived requirements for R and D effort.

Bauer, W.H.; Gordon, H.S.; Lackner, H.; Mettling, J.R.; Miller, J.E.

1980-09-01T23:59:59.000Z

400

Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit  

SciTech Connect

In a turbine having closed-circuit steam-cooling passages about the rim of the rotor during steady-state operation, compressor discharge air is supplied to the rotor bore for passage radially outwardly into the wheel space cavities between the wheels and spacers. Communicating slots and channels in the spacers and wheels at circumferentially spaced positions enable egress of the compressor discharge air into the hot gas flow path. At turbine startup, cooling air flows through the closed-circuit steam passages to cool the outer rim of the rotor while compressor discharge air pre-warms the wheels and spacers. At steady-state, cooling steam is supplied in the closed-circuit steam-cooling passages and compressor discharge air is supplied through the bore and into the wheel space cavities to cool the rotor.

Caruso, Philip M. (Selkirk, NY); Eldrid, Sacheverel Quentin (Saratoga Springs, NY); Ladhani, Azad A. (Niskayuna, NY); DeMania, Alan Richard (Niskayuna, NY); Palmer, Gene David (Clifton Park, NY); Wilson, Ian David (Clifton Park, NY); Rathbun, Lisa Shirley (Scotia, NY); Akin, Robert Craig (Schenectady, NY)

2002-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" 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

Recent High Heat Flux Tests on W-Rod-Armored Mockups  

Science Conference Proceedings (OSTI)

In the authors initial high heat flux tests on small mockups armored with W rods, done in the small electron beam facility (EBTS) at Sandia National Laboratories, the mockups exhibited excellent thermal performance. However, to reach high heat fluxes, they reduced the heated area to only a portion ({approximately}25%) of the sample. They have now begun tests in their larger electron beam facility, EB 1200, where the available power (1.2 MW) is more than enough to heat the entire surface area of the small mockups. The initial results indicate that, at a given power, the surface temperatures of rods in the EB 1200 tests is somewhat higher than was observed in the EBTS tests. Also, it appears that one mockup (PW-10) has higher surface temperatures than other mockups with similar height (10mm) W rods, and that the previously reported values of absorbed heat flux on this mockup were too high. In the tests in EB 1200 of a second mockup, PW-4, absorbed heat fluxes of {approximately}22MW/m{sup 2} were reached but the corresponding surface temperatures were somewhat higher than in EBTS. A further conclusion is that the simple 1-D model initially used in evaluating some of the results from the EBTS testing was not adequate, and 3-D thermal modeling will be needed to interpret the results.

NYGREN,RICHARD E.; YOUCHISON,DENNIS L.; MCDONALD,JIMMIE M.; LUTZ,THOMAS J.; MISZKIEL,MARK E.

2000-07-18T23:59:59.000Z

402

Heat shock, an exposure to high but sublethal temperature, protects cells, tissues and organisms from a subsequent  

E-Print Network (OSTI)

Heat shock, an exposure to high but sublethal temperature, protects cells, tissues and organisms be negatively affected by increases in temperature. We investigated the effects of heat shock contraction force at high temperatures. Furthermore, the heat-shock- induced thermoprotection of extensor

Robertson, Meldrum

403

High-temperature industrial process heat: technology assessment and introduction rationale  

SciTech Connect

Three specific topics of interest to DOE are addressed: to establish the significance and identify the role of high-temperature process heat in the nation's energy economy; to identify the role of solar thermal power in these high-temperature industrial applications in terms of possible markets and economic potential; and to recommend programmatic approaches for these solar thermal high-temperature process heat activities, including proposed content for initial Request for Proposals (RFPs) to accomplish such activities. The scope of the work required to accomplish these three purposes included the following: review of US industrial energy requirements, survey of current DOE low-temperature Agricultural and Industrial Process Heat Program, examination of high-temperature solar thermal electric systems already developed or under development by DOE and industry, and coordination with the high-energy user segments of industry (i.e., cement, chemical and petroleum) to find additional markets for some or all of the systems or components being developed in the DOE solar thermal electric program. Statistical data are presented identifying energy allocations to process heat and defining DOE's involvement. Three current fossil fuel process heat system examples are provided and the corresponding solar potential is identified.

1978-03-03T23:59:59.000Z

404

High-temperature industrial process heat: technology assessment and introduction rationale  

DOE Green Energy (OSTI)

Three specific topics of interest to DOE are addressed: to establish the significance and identify the role of high-temperature process heat in the nation's energy economy; to identify the role of solar thermal power in these high-temperature industrial applications in terms of possible markets and economic potential; and to recommend programmatic approaches for these solar thermal high-temperature process heat activities, including proposed content for initial Request for Proposals (RFPs) to accomplish such activities. The scope of the work required to accomplish these three purposes included the following: review of US industrial energy requirements, survey of current DOE low-temperature Agricultural and Industrial Process Heat Program, examination of high-temperature solar thermal electric systems already developed or under development by DOE and industry, and coordination with the high-energy user segments of industry (i.e., cement, chemical and petroleum) to find additional markets for some or all of the systems or components being developed in the DOE solar thermal electric program. Statistical data are presented identifying energy allocations to process heat and defining DOE's involvement. Three current fossil fuel process heat system examples are provided and the corresponding solar potential is identified.

Not Available

1978-03-03T23:59:59.000Z

405

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

Science Conference Proceedings (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

406

In-Situ Thermal Conductivity Testing Using a Portable Heat Flow Meter  

E-Print Network (OSTI)

A method has been developed for measuring heat losses from insulated systems in the field. While the measurements are not as precise as those made under laboratory conditions, they are more indicative of actual in service conditions. Extensive field tests have been carried out in petrochemical plants and power plants throughout the country. Some insulating materials have been found to lose up to 60% of their insulating value after a few years in service. Calcium silicate insulations were found to be the most durable.

Harr, K. S.; Hutto, F. B., Jr.

1979-01-01T23:59:59.000Z

407

Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. This picture highlights the root and tip vortex along with the turbulent structures in the wake of a deflected rudder through isosurface of instantaneous Q criterion colored by speed on a locally adapted unstructured finite element mesh with 1.2 billion elements. Michel Rasquin, Argonne National Laboratory Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF:

408

Experimental measurements in a radio frequency discharge heated supersonic flow: Evaluation of a potential electric propulsion thruster  

DOE Green Energy (OSTI)

An operational radio frequency discharge-driven supersonic flow system, which utilizes an inductively and capacitively coupled plasma (ICCP) tube to produce high enthalpy source gas, is described. The ICCP coupled to a properly designed nozzle represents a potential electric propulsion device. The high gas temperatures achieved in the plasma discharge (> 5000 K) and the electrodeless nature of the tube's operation offers potentially high thruster performance coupled and long operational lifetime. A preliminary characterization of the current system was established using emission and probe-based measurements. A nominal peak specific impulse of 155 s was estimated for operation with argon. The calculated thrust based upon the peak velocity and mass flow through the device is 1.1 N. 14 refs., 10 figs.

Wantuck, P.J.; Hull, D.E.

1991-01-01T23:59:59.000Z

409

Thermal evaluation of uranium silicide miniplates irradiated at high heat flux  

Science Conference Proceedings (OSTI)

The Gas Test Loop (GTL)-1 irradiation experiment was conducted in the Advanced Test Reactor (ATR) to assess corrosion performance of proposed booster fuel at heat flux levels ~30% above the design operating condition. Sixteen miniplates fabricated from 25% enriched, high-density (4.8 g U/cm3) U3Si2/Al dispersion fuel with 6061 aluminum cladding were subjected to peak beginning of cycle (BOC) heat fluxes ranging from 411 to 593 W/cm2. No adverse impacts to the miniplates were observed at these high heat flux levels. A detailed finite element model was constructed to calculate temperatures and heat flux for an as-run cycle average effective ATR south lobe power of 25.4 MW(t). Miniplate heat flux levels and fuel, cladding, hydroxide, and coolant–hydroxide interface temperatures were calculated using the average hydroxide thickness on each miniplate measured during post-irradiation examination. The purpose of this study was to obtain a best estimate of the as-run experiment temperatures to aid in establishing acceptable heat flux levels and designing fuel qualification experiments for this fuel type.

Donna P. Guillen

2012-09-01T23:59:59.000Z

410

Welding of dissimilar alloys for high temperature heat exchangers for SOFC  

DOE Green Energy (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

411

Towards Closing the Window on Strongly Interacting Dark Matter: Far-Reaching Constraints from Earth's Heat Flow  

E-Print Network (OSTI)

We point out a new and largely model-independent constraint on the dark matter scattering cross section with nucleons, applying when this quantity is larger than for typical weakly interacting dark matter candidates. When the dark matter capture rate in Earth is efficient, the rate of energy deposition by dark matter self-annihilation products would grossly exceed the measured heat flow of Earth. This improves the spin-independent cross section constraints by many orders of magnitude, and closes the window between astrophysical constraints (at very large cross sections) and underground detector constraints (at small cross sections). In the applicable mass range, from about 1 to about 10^{10} GeV, the scattering cross section of dark matter with nucleons is then bounded from above by the latter constraints, and hence must be truly weak, as usually assumed.

Gregory D. Mack; John F. Beacom; Gianfranco Bertone

2007-05-29T23:59:59.000Z

412

Impact of unsteady flow processes on the performance of a high speed axial flow compressor  

E-Print Network (OSTI)

This thesis examines the unsteady interactions between blade rows in a high Mach number, highly-loaded compressor stage. Two straight vane/rotor configurations with different axial spacing between vane and rotor are ...

Botros, Barbara Brenda

2008-01-01T23:59:59.000Z

413

Development and Demonstration of a High Efficiency, Rapid Heating, Low NOx Alternative to Conventional Heating of Round Steel Shapes, Steel Substrate (Strip) and Coil Box Transfer Bars  

SciTech Connect

Direct Flame Impingement involves the use of an array of very high-velocity flame jets impinging on a work piece to rapidly heat the work piece. The predominant mode of heat transfer is convection. Because of the locally high rate of heat transfer at the surface of the work piece, the refractory walls and exhaust gases of a DFI furnace are significantly cooler than in conventional radiant heating furnaces, resulting in high thermal efficiency and low NOx emissions. A DFI furnace is composed of a successive arrangement of heating modules through or by which the work piece is conveyed, and can be configured for square, round, flat, and curved metal shapes (e.g., billets, tubes, flat bars, and coiled bars) in single- or multi-stranded applications.

Kurek, Harry; Wagner, John

2010-01-25T23:59:59.000Z

414

Mold, flow, and economic considerations in high temperature precision casting  

E-Print Network (OSTI)

Casting high temperature alloys that solidify through a noticeable two phase region, specifically platinum-ruthenium alloys, is a particularly challenging task due to their high melting temperature and this necessitates ...

Humbert, Matthew S

2013-01-01T23:59:59.000Z

415

Heat reclaimer  

SciTech Connect

An apparatus for reclaiming heat from the discharge gas from a combustion fuel heating unit, which has: inlet and outlet sections; an expansion section whose circumference gradually increases in the direction of flow, thereby providing an increased area for heat transfer; flow splitter plates which lie within and act in conjunction with the expansion section wall to form flow compartments, which flow splitter plates and expansion section wall have a slope, with respect to the centroidal axis of the flow compartment not exceeding 0.1228, which geometry prevents a separation of the flow from the enclosing walls, thereby increasing heat transfer and maintaining the drafting function; and a reduction section which converges the flow to the outlet section.

Horkey, E.J.

1982-06-29T23:59:59.000Z

416

Subcooled flow boiling of fluorocarbons  

E-Print Network (OSTI)

A study was conducted of heat transfer and hydrodynamic behavior for subcooled flow boiling of Freon-113, one of a group of fluorocarbons suitable for use in cooling of high-power-density electronic components. Problems ...

Murphy, Richard Walter

1971-01-01T23:59:59.000Z

417

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry PI Name: William George PI Email: wgeorge@nist.gov Institution: National Institute of Standards and Technology Allocation Program: INCITE Allocation Hours at ALCF: 22 Million Year: 2012 Research Domain: Materials Science Flow properties of large-particle suspensions, such as concrete, cannot now be measured accurately in industrial settings. Flow simulations with many thousands of particles with a wide range of sizes and shapes in a non-Newtonian fluid matrix will enable the design of rheometers that will revolutionize the use of these instruments. The project's previous three-year INCITE award, granted in 2008, gave

418

Exploration of High Harmonic Fast Wave Heating on the National Spherical Torus Experiment  

SciTech Connect

High Harmonic Fast Wave (HHFW) heating has been proposed as a particularly attractive means for plasma heating and current drive in the high-beta plasmas that are achievable in spherical torus (ST) devices. The National Spherical Torus Experiment (NSTX) [Ono, M., Kaye, S.M., Neumeyer, S., et al., Proceedings, 18th IEEE/NPSS Symposium on Fusion Engineering, Albuquerque, 1999, (IEEE, Piscataway, NJ (1999), p. 53.)] is such a device. An radio-frequency (rf) heating system has been installed on NSTX to explore the physics of HHFW heating, current drive via rf waves and for use as a tool to demonstrate the attractiveness of the ST concept as a fusion device. To date, experiments have demonstrated many of the theoretical predictions for HHFW. In particular, strong wave absorption on electrons over a wide range of plasma parameters and wave parallel phase velocities, wave acceleration of energetic ions, and indications of current drive for directed wave spectra have been observed. In addition HHFW heating has been used to explore the energy transport properties of NSTX plasmas, to create H-mode (high-confinement mode) discharges with a large fraction of bootstrap current and to control the plasma current profile during the early stages of the discharge.

J.R. Wilson; R.E. Bell; S. Bernabei; M. Bitter; P. Bonoli; D. Gates; J. Hosea; B. LeBlanc; T.K. Mau; S. Medley; J. Menard; D. Mueller; M. Ono; C.K. Phillips; R.I. Pinsker; R. Raman; A. Rosenberg; P. Ryan; S. Sabbagh; D. Stutman; D. Swain; Y. Takase; J. Wilgen; the NSTX Team

2003-02-11T23:59:59.000Z

419

Study of Cross-flow Cooling Effects in a Stirling Engine Heat Exchanger.  

E-Print Network (OSTI)

??While much effort in Stirling engine development is placed on making the high-temperature region of the Stirling engine warmer, this research explores methods to lower… (more)

Eppard, Erin Frances

2011-01-01T23:59:59.000Z

420

TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow  

DOE Green Energy (OSTI)

TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.

Pruess, K.

1991-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "high heat flow" from the National Library of EnergyBeta (NLEBeta).
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We encourage you to perform a real-time search of NLEBeta
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421

Candidate alloys for cost-effective, high-efficiency, high-temperature compact/foil heat-exchangers  

SciTech Connect

Solid oxide fuel cell (SOFC) and molten carbonate fuel cell (MCFC) systems operate at high temperatures (up to 1000 C and 650 C, respectively), which makes them especially attractive sources for combined heat and power (CHP) cogeneration. However, improvements in the efficiency of heat exchange in these fuel cells require both development and careful processing of advanced cost-effective alloys for use in such high-temperature service conditions. The high-temperature properties of both sheet and foil forms of several alloys being considered for use in compact heat-exchangers (recuperators) have been characterized. Mechanical and creep-rupture testing, oxidation studies, and microstructural studies have been performed on commercially available sheet and foil forms of alloy 347, alloys 625, HR230, HR120, and the new AL20-25+Nb. These studies have led to a mechanistic understanding of the responses of these alloys to anticipated service conditions, and suggest that these alloys developed for gas- and micro-turbine recuperator applications are also suitable for use in fuel cell heat-exchangers. Additional work is still required to achieve foil forms with creep life comparable to thicker-section wrought product forms of the same alloys.

Evans, Neal D [ORNL; Maziasz, Philip J [ORNL; Shingledecker, John P [ORNL; Pint, Bruce A [ORNL; Yamamoto, Yukinori [ORNL

2007-01-01T23:59:59.000Z

422

Development of High Efficiency Carbon Dioxide Commercial Heat Pump Water Heater  

Science Conference Proceedings (OSTI)

Although heat pump water heaters are today widely accepted in both Japan and Europe, where energy costs are high and government incentives for their use exist, acceptance of such products in the US has been limited. While this trend is slowly changing with the introduction of heat pump water heaters into the residential market, but acceptance remains low in the commercial sector. The objective of the presented work is the development of a high efficiency R744 heat pump water heater for commercial applications with effective utilization of the cooling capability for air conditioning and/or refrigeration. The ultimate goal is to achieve total system COP of up to 8. This unit will be targeted at commercial use where some cooling load is typically needed year round, such as restaurants, hotels, nursing homes, and hospitals. This paper presents the performance results from the development of four R744 commercial heat pump water heater packages of approximately 35 kW and comparison to a commercially available baseline R134a unit of the same capacity and footprint. In addition, the influences of an internal heat exchanger and an enhanced evaporator on the system performance are described and recommendations are made for further improvements of the R744 system.

Michael PETERSEN; Chad D. BOWERS; Stefan ELBEL; Pega HRNJAK

2012-07-01T23:59:59.000Z

423

Using Plasmas for High-Speed Flow Control and Combustion Control.  

E-Print Network (OSTI)

??Experiments on characterization of Localized Arc Filament Plasma Actuators used for high-speed flow control, as well as experimental studies of chemiluminescence and chemi-ionization for flame… (more)

Keshav, Saurabh

2008-01-01T23:59:59.000Z

424

An Enskog based Monte Carlo method for high Knudsen number non-ideal gas flows  

E-Print Network (OSTI)

high Knudsen number non-ideal gas flows References [1] Gad-121: [2] Bird GA. Molecular gas dynamics. Oxford: Clarendon1976. [3] Bird GA. Molecular Gas Dynamics and the Direct

Wang, Moran; Li, Zhixin

2007-01-01T23:59:59.000Z

425

Marketing research for EE G Mound Applied Technologies' heat treatment process of high strength materials  

Science Conference Proceedings (OSTI)

This report summarizes research conducted by ITI to evaluate the commercialization potential of EG G Mound Applied Technologies' heat treatment process of high strength materials. The remainder of the report describes the nature of demand for maraging steel, extent of demand, competitors, environmental trends, technology life cycle, industry structure, and conclusion. (JL)

Shackson, R.H.

1991-10-09T23:59:59.000Z

426

Silicon Fresnel zone plates for high heat load X-ray microscopy  

Science Conference Proceedings (OSTI)

A technique to produce diffractive X-ray lenses optimized for high heat load applications is demonstrated. The lenses are made from single crystal silicon membranes, which have uniform thermal conductivity and homogeneous thermal expansion. Silicon Fresnel ... Keywords: Electron beam lithography, Fresnel zone plate, Reactive ion etching, X-ray microscopy

J. Vila-Comamala; K. Jefimovs; J. Raabe; B. Kaulich; C. David

2008-05-01T23:59:59.000Z

427

Method for establishing high permeability flow path between boreholes  

SciTech Connect

A method for linking adjacent boreholes in a subterranean formation, particularly in a coal gasification array, by firing a high velocity terradynamic projectile from one borehole to the other.

Dow, Jerome P. (Pleasanton, CA)

1978-01-01T23:59:59.000Z

428

Numerical investigation of transient heat and mass transfer in a parallel-flow liquid-desiccant absorber  

E-Print Network (OSTI)

model for heat and mass transfer processes in internallyof coupled heat and mass transfer processes in liquidHeat and mass transfer in liquid des- iccant air-conditioning process

Diaz, Gerardo

2010-01-01T23:59:59.000Z

429

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

two-phase zone, is the heat-pipe (i.e. , a zone of constant4a), when there is a heat pipe just above the emplacementduring ventilation, the heat-pipe signature is absent in

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

430

High average power CW FELs (Free Electron Laser) for application to plasma heating: Designs and experiments  

SciTech Connect

A short period wiggler (period {approximately} 1 cm), sheet beam FEL has been proposed as a low-cost source of high average power (1 MW) millimeter-wave radiation for plasma heating and space-based radar applications. Recent calculation and experiments have confirmed the feasibility of this concept in such critical areas as rf wall heating, intercepted beam ( body'') current, and high voltage (0.5 - 1 MV) sheet beam generation and propagation. Results of preliminary low-gain sheet beam FEL oscillator experiments using a field emission diode and pulse line accelerator have verified that lasing occurs at the predicted FEL frequency. Measured start oscillation currents also appear consistent with theoretical estimates. Finally, we consider the possibilities of using a short-period, superconducting planar wiggler for improved beam confinement, as well as access to the high gain, strong pump Compton regime with its potential for highly efficient FEL operation.

Booske, J.H.; Granatstein, V.L.; Radack, D.J.; Antonsen, T.M. Jr.; Bidwell, S.; Carmel, Y.; Destler, W.W.; Latham, P.E.; Levush, B.; Mayergoyz, I.D.; Zhang, Z.X. (Maryland Univ., College Park, MD (USA). Lab. for Plasma Research); Freund, H.P. (Science Applications International Corp., McLean, VA (USA))

1989-01-01T23:59:59.000Z

431

High Levels of Winter Air Pollution under the Influence of the Urban Heat Island along the Shore of Tokyo Bay  

Science Conference Proceedings (OSTI)

A wintertime small-scale sea breeze associated with high levels of air pollution is described, in which the urban heat island plays an important role.

Hiroshi Yoshikado; Makoto Tsuchida

1996-10-01T23:59:59.000Z

432

High Efficiency Adsorption Chillers: High Efficiency Adsorption Cooling Using Metal Organic Heat Carriers  

SciTech Connect

BEETIT Project: PNNL is incorporating significant improvements in materials that adsorb liquids or gases to design more efficient adsorption chillers. An adsorption chiller is a type of air conditioner that is powered by heat, solar or waste heat, or combustion of natural gas. Unlike typical chillers, this type has few moving parts and uses almost no electricity to operate. PNNL is designing adsorbent materials at the molecular level with at least 3 times higher refrigerant capacity and up to 20 times faster kinetics than adsorbents used in current chillers. By using the new adsorbent, PNNL is able to create a chiller that is significantly smaller, has twice the energy efficiency, and lower costs for materials and assembly time compared to conventional adsorption chillers.

None

2010-10-01T23:59:59.000Z

433

Field Monitoring of a Geothermal Heat Pump Water Heater: Unicoi County High School, Erwin, Tennessee  

Science Conference Proceedings (OSTI)

A geothermal heat pump water heater (HPWH) system -- installed to preheat water entering a 250-gallon gas-fired water heater (GWH) at a Tennessee high school -- reduced water-heating costs by 34 percent per year, compared to the base case GWH system. This report provides res