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1

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

2

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

3

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

4

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

5

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

6

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

7

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

8

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

9

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

E-Print Network (OSTI)

1 CORRELATING EVAPORATION HEAT TRANSFER COEFFICIENT OF REFRIGERANT R-134a IN A PLATE HEAT EXCHANGER for evaporation heat transfer coefficient of refrigerant R-134a flowing in a plate heat exchanger. Correlation heat exchanger are found to result in large discrepancies with their own experimental data

Kandlikar, Satish

10

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

11

Triple loop heat exchanger for an absorption refrigeration system  

DOE Patents (OSTI)

A triple loop heat exchanger for an absorption refrigeration system is disclosed. The triple loop heat exchanger comprises portions of a strong solution line for conducting relatively hot, strong solution from a generator to a solution heat exchanger of the absorption refrigeration system, conduit means for conducting relatively cool, weak solution from the solution heat exchanger to the generator, and a bypass system for conducting strong solution from the generator around the strong solution line and around the solution heat exchanger to an absorber of the refrigeration system when strong solution builds up in the generator to an undesirable level. The strong solution line and the conduit means are in heat exchange relationship with each other in the triple loop heat exchanger so that, during normal operation of the refrigeration system, heat is exchanged between the relatively hot, strong solution flowing through the strong solution line and the relatively cool, weak solution flowing through the conduit means. Also, the strong solution line and the bypass system are in heat exchange relationship in the triple loop heat exchanger so that if the normal flow path of relatively hot, strong solution flowing from the generator to an absorber is blocked, then this relatively, hot strong solution which will then be flowing through the bypass system in the triple loop heat exchanger, is brought into heat exchange relationship with any strong solution which may have solidified in the strong solution line in the triple loop heat exchanger to thereby aid in desolidifying any such solidified strong solution.

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

12

Air-Conditioning, Heating, and Refrigeration Institute (AHRI...  

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

Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI These comments...

13

Ground Loops for Heat Pumps and Refrigeration  

E-Print Network (OSTI)

Ground loops are used for water source heat pumps. Refrigeration can be put on a ground loop. Water-cooled condensing units are more efficient than air-cooled, and they can be put indoors. Indoor location makes piping for desuperheater hot water easy. Since refrigeration equipment runs more than heat pumps, energy savings can be large for ground-coupled refrigeration. The paper presents a design procedure for ground loops for heat pumps, hot water, ice machines, and water-cooled refrigeration. It gives an overview of the commercial ground-coupled systems in Louisiana that have both refrigeration and heat pumps. Systems vary from small offices to a three-story office building with 187 tons. A chain of hamburger outlets uses total ground-coupling in all of its stores. A grocery store has ground-coupling for heat pumps and refrigeration. Desuperheaters provide 80 percent of the hot water for a coin laundry in the same building. A comparison of energy costs in a bank with a ground-coupled heat pump system to a similar bank with air-conditioning and gas for heat revealed a 31 percent reduction in utility costs for the ground-coupled building. Two buildings of the Mississippi Power and Light Co. have ground-coupled heat pumps in one, and high efficiency air source heat pumps in the other. Energy savings in nine months was 60,000 kWh (25 percent), and electric peak demand was reduced 42 kW (35 percent).

Braud, H. J.

1986-01-01T23:59:59.000Z

14

Waste heat driven absorption refrigeration process and system  

DOE Patents (OSTI)

Absorption cycle refrigeration processes and systems are provided which are driven by the sensible waste heat available from industrial processes and other sources. Systems are disclosed which provide a chilled water output which can be used for comfort conditioning or the like which utilize heat from sensible waste heat sources at temperatures of less than 170.degree. F. Countercurrent flow equipment is also provided to increase the efficiency of the systems and increase the utilization of available heat.

Wilkinson, William H. (Columbus, OH)

1982-01-01T23:59:59.000Z

15

Waste Heat Recapture from Supermarket Refrigeration Systems  

DOE Green Energy (OSTI)

The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

Fricke, Brian A [ORNL

2011-11-01T23:59:59.000Z

16

Heat exchanger bypass system for an absorption refrigeration system  

DOE Patents (OSTI)

A heat exchanger bypass system for an absorption refrigeration system is disclosed. The bypass system operates to pass strong solution from the generator around the heat exchanger to the absorber of the absorption refrigeration system when strong solution builds up in the generator above a selected level indicative of solidification of strong solution in the heat exchanger or other such blockage. The bypass system includes a bypass line with a gooseneck located in the generator for controlling flow of strong solution into the bypass line and for preventing refrigerant vapor in the generator from entering the bypass line during normal operation of the refrigeration system. Also, the bypass line includes a trap section filled with liquid for providing a barrier to maintain the normal pressure difference between the generator and the absorber even when the gooseneck of the bypass line is exposed to refrigerant vapor in the generator. Strong solution, which may accumulate in the trap section of the bypass line, is diluted, to prevent solidification, by supplying weak solution to the trap section from a purge system for the absorption refrigeration system.

Reimann, Robert C. (Lafayette, NY)

1984-01-01T23:59:59.000Z

17

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe or pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, J.A.; Prenger, F.C. Jr.

1985-10-25T23:59:59.000Z

18

Magnetic refrigeration apparatus with heat pipes  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 4 to 20 K range utilizes heat pipes to transfer heat to and from the magnetic material at the appropriate points during the material's movement. In one embodiment circular disks of magnetic material can be interleaved with the ends of the heat pipes. In another embodiment a mass of magnetic material reciprocatingly moves between the end of the heat pipe of pipes that transmits heat from the object of cooling to the magnetic material and the end of the heat pipe or pipes that transmits heat from the magnetic material to a heat sink.

Barclay, John A. (Los Alamos, NM); Prenger, Jr., F. Coyne (Madison, WI)

1987-01-01T23:59:59.000Z

19

Economizer refrigeration cycle space heating and cooling system and process  

DOE Patents (OSTI)

This invention relates to heating and cooling systems and more particularly to an improved system utilizing a Stirling Cycle engine heat pump in a refrigeration cycle. 18 figs.

Jardine, D.M.

1983-03-22T23:59:59.000Z

20

Economizer refrigeration cycle space heating and cooling system and process  

DOE Patents (OSTI)

This invention relates to heating and cooling systems and more particularly to an improved system utilizing a Stirling Cycle engine heat pump in a refrigeration cycle.

Jardine, Douglas M. (Colorado Springs, CO)

1983-01-01T23:59:59.000Z

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

Literature survey of heat transfer enhancement techniques in refrigeration applications  

Science Conference Proceedings (OSTI)

A survey has been performed of the technical and patent literature on enhanced heat transfer of refrigerants in pool boiling, forced convection evaporation, and condensation. Extensive bibliographies of the technical literature and patents are given. Many passive and active techniques were examined for pure refrigerants, refrigerant-oil mixtures, and refrigerant mixtures. The citations were categorized according to enhancement technique, heat transfer mode, and tube or shell side focus. The effects of the enhancement techniques relative to smooth and/or pure refrigerants were illustrated through the discussion of selected papers. Patented enhancement techniques also are discussed. Enhanced heat transfer has demonstrated significant improvements in performance in many refrigerant applications. However, refrigerant mixtures and refrigerant-oil mixtures have not been studied extensively; no research has been performed with enhanced refrigerant mixtures with oil. Most studies have been of the parametric type; there has been inadequate examination of the fundamental processes governing enhanced refrigerant heat transfer, but some modeling is being done and correlations developed. It is clear that an enhancement technique must be optimized for the refrigerant and operating condition. Fundamental processes governing the heat transfer must be examined if models for enhancement techniques are to be developed; these models could provide the method to optimize a surface. Refrigerant mixtures, with and without oil present, must be studied with enhancement devices; there is too little known to be able to estimate the effects of mixtures (particularly NARMs) with enhanced heat transfer. Other conclusions and recommendations are offered.

Jensen, M.K.; Shome, B. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Mechanical Engineering, Aeronautical Engineering and Mechanics

1994-05-01T23:59:59.000Z

22

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

DOE Patents (OSTI)

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

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

1997-04-22T23:59:59.000Z

23

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

DOE Patents (OSTI)

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

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

1997-01-01T23:59:59.000Z

24

Electric, Gas, Water, Heating, Refrigeration, and Street Railways...  

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

and Street Railways Facilities and Service (South Dakota) Electric, Gas, Water, Heating, Refrigeration, and Street Railways Facilities and Service (South Dakota) < Back...

25

Status of not-in-kind refrigeration technologies for household space conditioning, water heating and food refrigeration  

Science Conference Proceedings (OSTI)

This paper presents a review of the next generation not-in-kind technologies to replace conventional vapor compression refrigeration technology for household applications. Such technologies are sought to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration for domestic use. These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption refrigeration, adsorption refrigeration, and compressor driven metal hydride heat pumps. Furthermore, heat pump water heating and integrated heat pump systems are also discussed due to their significant energy saving potential for water heating and space conditioning in households. The paper provides a snapshot of the future R&D needs for each of the technologies along with the associated barriers. Both thermoelectric and magnetic technologies look relatively attractive due to recent developments in the materials and prototypes being manufactured.

Bansal, Pradeep [ORNL; Vineyard, Edward Allan [ORNL; Abdelaziz, Omar [ORNL

2012-01-01T23:59:59.000Z

26

The Effect of Circuiting Arrangement on the Thermal Performance of Refrigeration Mixtures in Tube-and-Fin Condensing Heat Exchangers  

SciTech Connect

For the pure or azeotropic refrigerants typically used in present air conditioning and refrigeration applications, the refrigerant changes phase at a constant temperature. Thus, the refrigerant circuiting arrangement such as crossfiow, counterfiow, or cross-counterflow, has no effect on the thermal performance. For zeotropic refrigerant mixtures, however, the phase-change occurs over a temperature range, or "glide", and the refrigerant circuiting arrangement, or flow path through the heat exchanger, can affect the thermal performance of both the heat exchangers as well as the overall efficiency of the vapor compression cooling cycle. The effects of tsvo diflerent circuiting arrangements on the thermal performance of a zeotropic retligerant mixture and an almost azeotropic refrigerant mixture in a four-row cross-countertlow heat exchanger arrangement are reported here. The two condensers differ only in the manner of circuiting the refrigerant tubes, where one has refrigerant always flowing downward in the active heat transfer region ("identical order") and the other has refrigerant alternating flow direction in the active heat transfer region ("inverted order"). All other geometric parameters, such as bce are% fin louver geometry, refrigerant tube size and enhancement etc., are the same for both heat exchangers. One refrigerant mixture (R-41OA) un&rgoes a small temperature change ("low glide") during phase change, and the other retligerant mixture (a multi- component proprietary mixture) has a substantial temperature change ("high glide") of approximately 10"C during the phase change process. The overall thermal conductance, two-phase conductance, and pressure drop are presented. For the flow conditions of these tests, which are representative of resi&ntial cooling conditions, inverted order circuiting is more desirable than identical order. The potential thermal advantages of the i&ntical order arrangement for high-glide zeotropic refrigerant mixtures are negated by the increased parasitic refrigerant-side pressure drop utiortunately resulting from tkbrication requirements of the identical order circuiting.

Chen, D.T.; Conklin, J.C.

1999-03-15T23:59:59.000Z

27

Research of Refrigerant Phase-Change Stirling-Cycle Heat Engines  

Science Conference Proceedings (OSTI)

This paper firstly introduces the principles of Refrigerant Phase-Change Stirling-Cycle solar power towers This heat engines use solar reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant ... Keywords: refrigerant phase-change cycle, heat engines, finite-time thermodynamics

Dezhong Huang; Fuer Wu

2011-01-01T23:59:59.000Z

28

Global warming impacts of ozone-safe refrigerants and refrigeration, heating, and air-conditioning technologies  

SciTech Connect

International agreements mandate the phase-out of many chlorine containing compounds that are used as the working fluid in refrigeration, air-conditioning, and heating equipment. Many of the chemical compounds that have been proposed, and are being used in place of the class of refrigerants eliminated by the Montreal Protocol are now being questioned because of their possible contributions to global warming. Natural refrigerants are put forth as inherently superior to manufactured refrigerants because they have very low or zero global warming potentials (GWPs). Questions are being raised about whether or not these manufactured refrigerants, primarily hydrofluorocarbons (HFCs), should be regulated and perhaps phased out in much the same manner as CFCs and HCFCs. Several of the major applications of refrigerants are examined in this paper and the results of an analysis of their contributions to greenhouse warming are presented. Supermarket refrigeration is shown to be an application where alternative technologies have the potential to reduce emissions of greenhouse gases (GHG) significantly with no clear advantage to either natural or HFC refrigerants. Mixed results are presented for automobile air conditioners with opportunities to reduce GHG emissions dependent on climate and comfort criteria. GHG emissions for hermetic and factory built systems (i.e. household refrigerators/freezers, unitary equipment, chillers) are shown to be dominated by energy use with much greater potential for reduction through efficiency improvements than by selection of refrigerant. The results for refrigerators also illustrate that hydrocarbon and carbon dioxide blown foam insulation have lower overall effects on GHG emissions than HFC blown foams at the cost of increased energy use.

Fischer, S.; Sand, J.; Baxter, V.

1997-12-01T23:59:59.000Z

29

Heat pump employing optimal refrigerant compressor for low pressure ratio applications  

DOE Patents (OSTI)

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler for circulating the fluid in heat exchange relationship with a refrigerant fluid; two refrigerant heat exchangers; one for effecting the heat exchange with the fluid and a second refrigerant-heat exchange fluid heat exchanger for effecting a low pressure ratio of compression of the refrigerant; a rotary compressor for compressing the refrigerant with low power consumption at the low pressure ratio; at least one throttling valve connecting at the inlet side of heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit serially connecting the above elements; refrigerant in the circuit; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant.

Ecker, Amir L. (Dallas, TX)

1982-01-01T23:59:59.000Z

30

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

31

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

32

Heat pump/refrigerator using liquid working fluid  

DOE Patents (OSTI)

A heat transfer device is described that can be operated as a heat pump or refrigerator, which utilizes a working fluid that is continuously in a liquid state and which has a high temperature-coefficient of expansion near room temperature, to provide a compact and high efficiency heat transfer device for relatively small temperature differences as are encountered in heating or cooling rooms or the like. The heat transfer device includes a pair of heat exchangers that may be coupled respectively to the outdoor and indoor environments, a regenerator connecting the two heat exchangers, a displacer that can move the liquid working fluid through the heat exchangers via the regenerator, and a means for alternately increasing and decreasing the pressure of the working fluid. The liquid working fluid enables efficient heat transfer in a compact unit, and leads to an explosion-proof smooth and quiet machine characteristic of hydraulics. The device enables efficient heat transfer as the indoor-outdoor temperature difference approaches zero, and enables simple conversion from heat pumping to refrigeration as by merely reversing the direction of a motor that powers the device.

Wheatley, John C. (Del Mar, CA); Paulson, Douglas N. (Del Mar, CA); Allen, Paul C. (Solana Beach, CA); Knight, William R. (Corvallis, OR); Warkentin, Paul A. (San Diego, CA)

1982-01-01T23:59:59.000Z

33

Electric equipment providing space conditioning, water heating, and refrigeration consumes 12.5% of the nation's  

E-Print Network (OSTI)

-acceptable refrigerants. Whether involving design of specific new products or refriger- ants to which the entire industryElectric equipment providing space conditioning, water heating, and refrigeration consumes 12 are the heart of air conditioners, heat pumps, chillers, supermarket refrigeration systems, and more. Global use

Oak Ridge National Laboratory

34

New waste-heat refrigeration unit cuts flaring, reduces pollution  

Science Conference Proceedings (OSTI)

Planetec Utility Services Co. Inc. and Energy Concepts Co. (ECC), with the help of the US Department of Energy (DOE), developed and commissioned a unique waste-heat powered LPG recovery plant in August 1997 at the 30,000 b/d Denver refinery, operated by Ultramar Diamond Shamrock (UDS). This new environmentally friendly technology reduces flare emissions and the loss of salable liquid-petroleum products to the fuel-gas system. The waste heat ammonia absorption refrigeration plant (Whaarp) is the first technology of its kind to use low-temperature waste heat (295 F) to achieve sub-zero refrigeration temperatures ({minus}40 F) with the capability of dual temperature loads in a refinery setting. The ammonia absorption refrigeration is applied to the refinery`s fuel-gas makeup streams to condense over 180 b/d of salable liquid hydrocarbon products. The recovered liquid, about 64,000 bbl/year of LPG and gasoline, increases annual refinery profits by nearly $1 million, while substantially reducing air pollution emissions from the refinery`s flare.

Brant, B.; Brueske, S. [Planetec Utility Services Co., Inc., Evergreen, CO (United States); Erickson, D.; Papar, R. [Energy Concepts Co., Annapolis, MD (United States)

1998-05-18T23:59:59.000Z

35

Waste Heat Recovery from Refrigeration in a Meat Processing Facility  

E-Print Network (OSTI)

A case study is reviewed on a heat recovery system installed in a meat processing facility to preheat water for the plant hot water supply. The system utilizes waste superheat from the facility's 1,350-ton ammonia refrigeration system. The heat recovery system consists of a shell and tube heat exchanger (16"? x 14'0") installed in the compressor hot gas discharge line. Water is recirculated from a 23,000-gallon tempered water storage tank to the heat exchanger by a circulating pump at the rate of 100 gallons per minute. All make-up water to the plant hot water system is supplied from this tempered water storage tank, which is maintained at a constant filled level. Tests to determine the actual rate of heat recovery were conducted from October 3, 1979 to October 12, 1979, disclosing an average usage of 147,000 gallons of hot water daily. These tests illustrated a varied heat recovery of from 0.5 to 1.0 million BTU per hour. The deviations were the result of both changing refrigeration demands and compressor operating modes. An average of 16 million BTU per day was realized, resulting in reduced boiler fuel costs of $30,000 annually, based on the present $.80 per gallon #2 fuel oil price. At the total installed cost of $79,000, including test instrumentation, the project was found to be economically viable. The study has demonstrated the technical and economic feasibility of refrigeration waste heat recovery as a positive energy conservation strategy which has broad applications in industry and commerce.

Murphy, W. T.; Woods, B. E.; Gerdes, J. E.

1980-01-01T23:59:59.000Z

36

Analysis of Mass Flow and Enhanced Mass Flow Methods of Flashing Refrigerant-22 from a Small Vessel  

E-Print Network (OSTI)

The mass flow characteristics of flashing Refrigerant-22 from a small vessel were investigated. A flash boiling apparatus was designed and built. It was modeled after the flashing process encountered by the accumulator of air-source heat pump systems. Three small pyrex glass vessels were used to hold the refrigerant and allow for visualization studies of the flashing process. Baseline experiments were run varying initial pressure, initial refrigerant amount, orifice diameter, and vessel geometry. Three sets of experiments were run using two passive enhancement methods (the addition of steel balls and the addition of small amounts of oil) and one active enhancement method (the addition of an immersion heater). Furthermore, a lumped-parameter analytical model was developed from basic thermodynamic principles that predicted the rate of depressurization for the flashing refrigerant. The study showed that the initial refrigerant amount and the orifice size had the greatest influence on the mass flow and pressure characteristics during each sixty second test. The initial pressure and vessel volume had less of an impact under the conditions tested. Two of the enhancement methods consistently increased the amount of refrigerant flashed during the tests as compared to the baseline data for the same initial conditions. The addition a 1 cm layer of 3.6 mm steel balls to the base of the vessel increased the amount flashed from 21% to 81% and the addition of the 215-watt flat-spiral immersion heater the increased the amount flashed from 47% to 111 %. Foaming at the vapor-liquid interface was observed with the refrigerant-oil mixture experiments as two of the eight test conditions averaged an increase while six averaged a decrease, ranging from a 21% increase to a 27% decrease. The analytical depressurization model predicted general pressure and mass flux trends, and revisions to the model improved pressure predictions to within ±11%.

Nutter, Darin Wayne

1994-12-01T23:59:59.000Z

37

Influence of External Heat Source on Transcritical CO2 Refrigeration System  

Science Conference Proceedings (OSTI)

Synthetic refrigerants such as CFCs and HCFCs are harmful to the ozone and could cause greenhouse effect. Refrigerant alternatives research is very urgent. CO2 as a natural working fluid has zero ODP and its GWP=1, is receiving more and more attention ... Keywords: Coefficient of Performance, Experimental Investigation, Heat Source, Transcritical CO2 Refrigeration System

Liu Yingfu; Xiao Jian; Jin Guangya

2012-07-01T23:59:59.000Z

38

Application Availability of Insulation Heat of the Terrace in a Rebuilt Refrigerator  

E-Print Network (OSTI)

Dealing with the terrace in rebuilt refrigerators influences the performance characteristics, performance safety and construction costs. This paper researches the heat transfer of the terrace of the rebuilt refrigerator by the numerical method, analyzes the temperature distribution of the terrace, and supplies guidance for rebuilding refrigerators.

Qu, C.; Sun, Y.; Chen, Z.

2006-01-01T23:59:59.000Z

39

Thermoacoustic engines and refrigerators  

SciTech Connect

This report is a transcript of a practice lecture given in preparation for a review lecture on the operation of thermoacoustic engines and refrigerators. The author begins by a brief review of the thermodynamic principles underlying the operation of thermoacoustic engines and refrigerators. Remember from thermodynamics class that there are two kinds of heat engines, the heat engine or the prime mover which produces work from heat, and the refrigerator or heat pump that uses work to pump heat. The device operates between two thermal reservoirs at temperatures T{sub hot} and T{sub cold}. In the heat engine, heat flows into the device from the reservoir at T{sub hot}, produces work, and delivers waste heat into the reservoir at T{sub cold}. In the refrigerator, work flows into the device, lifting heat Q{sub cold} from reservoir at T{sub cold} and rejecting waste heat into the reservoir at T{sub hot}.

Swift, G.

1996-12-31T23:59:59.000Z

40

Electric, Gas, Water, Heating, Refrigeration, and Street Railways Facilities and Service (South Dakota)  

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

This legislation contains provisions for facilities and service related to electricity, natural gas, water, heating, refrigeration, and street railways. The chapter addresses the construction and...

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

Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery  

SciTech Connect

An emerging DOE-sponsored technology has been deployed. The technology recovers light ends from a catalytic reformer plant using waste heat powered ammonia absorption refrigeration. It is deployed at the 17,000 bpd Bloomfield, New Mexico refinery of Western Refining Company. The technology recovers approximately 50,000 barrels per year of liquefied petroleum gas that was formerly being flared. The elimination of the flare also reduces CO2 emissions by 17,000 tons per year, plus tons per year reductions in NOx, CO, and VOCs. The waste heat is supplied directly to the absorption unit from the Unifiner effluent. The added cooling of that stream relieves a bottleneck formerly present due to restricted availability of cooling water. The 350oF Unifiner effluent is cooled to 260oF. The catalytic reformer vent gas is directly chilled to minus 25oF, and the FCC column overhead reflux is chilled by 25oF glycol. Notwithstanding a substantial cost overrun and schedule slippage, this project can now be considered a success: it is both profitable and highly beneficial to the environment. The capabilities of directly-integrated waste-heat powered ammonia absorption refrigeration and their benefits to the refining industry have been demonstrated.

Donald C, Energy Concepts Co.; Lauber, Eric, Western Refining Co.

2008-06-20T23:59:59.000Z

42

Control system for heat exchangers fans in a refrigeration system  

Science Conference Proceedings (OSTI)

The paper presents a method for controlling evaporator and condenser fans in a refrigeration system. The refrigeration system includes a refrigerant circuit defined by a compressor, a condenser, a throttling device, and an evaporator. The system includes ... Keywords: controlling, fan, refrigeration system, variable frequency drive unit

Cristian Iosifescu; Valeriu Damian; C?lin Ciufudean

2010-05-01T23:59:59.000Z

43

Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow and airflow for a breadboard CVSHP (Miller 1987a). This previous work was continued in the present study by investigation  

E-Print Network (OSTI)

#12;Previous work conducted in the laboratory demonstrated optimal control of refrigerant flow optimal refrigerant flow and airflow control settings. Previous studies by Tanaka and Yamanaka (1982 pump were replaced with fine metering hand valves having variable flow area for both heating

Oak Ridge National Laboratory

44

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

45

Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics  

SciTech Connect

The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.

Lowe, K.T.

2005-10-07T23:59:59.000Z

46

Floating Refrigerant Loop Based on R-134a Refrigerant Cooling of High-Heat Flux Electronics  

SciTech Connect

The Oak Ridge National Laboratory (ORNL) Power Electronics and Electric Machinery Research Center (PEEMRC) have been developing technologies to address the thermal issues associated with hybrid vehicles. Removal of the heat generated from electrical losses in traction motors and their associated power electronics is essential for the reliable operation of motors and power electronics. As part of a larger thermal control project, which includes shrinking inverter size and direct cooling of electronics, ORNL has developed U.S. Patent No. 6,772,603 B2, ''Methods and Apparatus for Thermal Management of Vehicle Systems and Components'' [1], and patent pending, ''Floating Loop System for Cooling Integrated Motors and Inverters Using Hot Liquid Refrigerant'' [2]. The floating-loop system provides a large coefficient of performance (COP) for hybrid-drive component cooling. This loop (based on R-134a) is integrated with a vehicle's existing air-conditioning (AC) condenser, which dissipates waste heat to the ambient air. Because the temperature requirements for cooling of power electronics and electric machines are not as low as that required for passenger compartment air, this adjoining loop can operate on the high-pressure side of the existing AC system. This arrangement also allows the floating loop to run without the need for the compressor and only needs a small pump to move the liquid refrigerant. For the design to be viable, the loop must not adversely affect the existing system. The loop should also provide a high COP, a flat-temperature profile, and low-pressure drop. To date, the floating-loop test prototype has successfully removed 2 kW of heat load in a 9 kW automobile passenger AC system with and without the automotive AC system running. The COP for the tested floating-loop system ranges from 40-45, as compared to a typical AC system COP of about 2-4. The estimated required waste-heat load for future hybrid applications is 5.5 kW and the existing system could be easily scaleable for this larger load.

Lowe, K.T.

2005-10-07T23:59:59.000Z

47

Unique method for liquid nitrogen precooling of a plate fin heat exchanger in a helium refrigeration cycle  

E-Print Network (OSTI)

Unique method for liquid nitrogen precooling of a plate fin heat exchanger in a helium refrigeration cycle

Weber, T B; Howell, G; Racine, M; Weisend, J G

2004-01-01T23:59:59.000Z

48

A continuous heat regenerative adsorption refrigerator using spiral plate heat exchanger as adsorbers: improvements  

SciTech Connect

Spiral plate heat exchangers as adsorbers have been proposed, and a prototype heat regenerative adsorption refrigerator using activated carbon-methanol pair has been developed and tested. Various improvements have been made, the authors get a specific cooling power for 2.6 kg-ice/day-kg adsorbent at the condition of generation temperature lower than 100 C. Discussions on the arrangements of thermal cycles and influences of design are shown.

Wang, R.Z.; Wu, J.Y.; Xu, Y.X. [Shanghai Jiao Tong Univ. (China). Inst. of Refrigeration and Cryogenics

1999-02-01T23:59:59.000Z

49

COFELY Refrigeration | Rdiger Roth | European Heat Pump Summit 2013 CopyrightCOFELYDeutuschlandGmbH2009.AlleRechtevorbehalten.  

E-Print Network (OSTI)

©COFELYDeutuschlandGmbH2009.AlleRechtevorbehalten. Industrial Design #12;COFELY Refrigeration | RĂŒdiger Roth | European HeatCOFELY Refrigeration | RĂŒdiger Roth | European Heat Pump Summit 2013 Seite 1 Copyright©COFELYDeutuschlandGmbH2009.AlleRechtevorbehalten. #12;COFELY Refrigeration | RĂŒdiger Roth | European Heat Pump Summit 2013

Oak Ridge National Laboratory

50

Energy Simulation of Integrated Multiple-Zone Variable Refrigerant Flow System  

Science Conference Proceedings (OSTI)

We developed a detailed steady-state system model, to simulate the performance of an integrated five-zone variable refrigerant flow (VRF)heat pump system. The system is multi-functional, capable of space cooling, space heating, combined space cooling and water heating, and dedicated water heating. Methods were developed to map the VRF performance in each mode, based on the abundant data produced by the equipment system model. The performance maps were used in TRNSYS annual energy simulations. Using TRNSYS, we have successfully setup and run cases for a multiple-split, VRF heat pump and dehumidifier combination in 5-zone houses in 5 climates that control indoor dry-bulb temperature and relative humidity. We compared the calculated energy consumptions for the VRF heat pump against that of a baseline central air source heat pump, coupled with electric water heating and the standalone dehumidifiers. In addition, we investigated multiple control scenarios for the VRF heat pump, i.e. on/off control, variable indoor air flow rate, and using different zone temperature setting schedules, etc. The energy savings for the multiple scenarios were assessed.

Shen, Bo [ORNL; Rice, C Keith [ORNL; Baxter, Van D [ORNL

2013-01-01T23:59:59.000Z

51

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

52

Dual source heat pump  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

53

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

54

Direct Refrigeration from Heat Recovery Using 2-Stage Absorption Chillers  

E-Print Network (OSTI)

Although the cost of some fossil fuels has moderated, the importance of energy conservation by heat recovery has not diminished. The application of waste heat generated steam to produce chilled water is not new. However, there is a newly developed absorption chiller which can produce chilled water 44% more efficiently than the conventional single stage absorption chillers. The new 2-stage parallel flow system makes the chiller package more compact, more efficient, and easier to operate. Many types of waste heat, not just steam, can be used directly in this new chiller without the need for costly recovery and conversion systems.

Hufford, P. E.

1983-01-01T23:59:59.000Z

55

Air-Conditioning, Heating, and Refrigeration Institute (AHRI) Regulatory Burden RFI  

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

These comments are submitted by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) in response to the U.S. Department of Energy’s (DOE) notice in the August 8, 2012 Federal Register...

56

IMPACTS OF REFRIGERANTLINE LENGTH ON SYSTEM EFFICIENCY IN RESIDENTIAL HEATING AND COOLING SYSTEMS USING REFRIGERANT DISTRIBUTION.  

Science Conference Proceedings (OSTI)

The effects on system efficiency of excess refrigerant line length are calculated for an idealized residential heating and cooling system. By excess line length is meant refrigerant tubing in excess of the 25 R provided for in standard equipment efficiency test methods. The purpose of the calculation is to provide input for a proposed method for evaluating refrigerant distribution system efficiency. A refrigerant distribution system uses refrigerant (instead of ducts or pipes) to carry heat and/or cooling effect from the equipment to the spaces in the building in which it is used. Such systems would include so-called mini-splits as well as more conventional split systems that for one reason or another have the indoor and outdoor coils separated by more than 25 ft. This report performs first-order calculations of the effects on system efficiency, in both the heating and cooling modes, of pressure drops within the refrigerant lines and of heat transfer between the refrigerant lines and the space surrounding them.

ANDREWS, J.W.

2001-04-01T23:59:59.000Z

57

Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration  

E-Print Network (OSTI)

refrigeration processes (4 5) Vapor-compression refrigeration processes (4-5) Absorption refrigeration; Gas processing (O2, H2, CO2, LPG, LNG...) (3) Air conditioning, cooling towers, rg/pages/zon Air conditioning, cooling towers, food cooling and freezing (4) Heat pumps, heat pipes, special ww.sgisland.o p p

Zevenhoven, Ron

58

Multiple source heat pump  

DOE Patents (OSTI)

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

Ecker, Amir L. (Duncanville, TX)

1983-01-01T23:59:59.000Z

59

Multiple-Zone Variable Refrigerant Flow System Modeling and Equipment Performance Mapping  

Science Conference Proceedings (OSTI)

We developed a variable refrigerant flow (VRF) vapor compression system model, which has five indoor units, one outdoor unit and one water heater. The VRF system can run simultaneous space conditioning (cooling or heating) and water heating. The indoor units and outdoor unit use fin-&-tube coil heat exchangers, and the water heater uses a tube-in-tube heat exchanger. The fin-&-tube coil heat exchangers are modeled using a segment-by-segment approach and the tube-in-tube water heater is modeled using a phase-by-phase approach. The compressor used is a variable-speed rotary design. We calibrated our model against a manufacturer s product literature. Based on the vapor compression system model, we investigated the methodology for generating VRF equipment performance maps, which can be used for energy simulations in TRNSYS and EnergyPlus, etc. In the study, the major independent variables for mapping are identified and the deviations between the simplified performance map and the actual equipment system simulation are quantified.

Shen, Bo [ORNL; Rice, C Keith [ORNL

2012-01-01T23:59:59.000Z

60

Effect of surface conditions on boiling heat transfer of refrigerants in shell-and-tube evaporators  

Science Conference Proceedings (OSTI)

Experimental results are presented for the boiling heat transfer performance of R 22 and R 717 on surfaces with porous metallized coatings. A calculational-theoretical model is given for predicting the heat transfer of refrigerants boiling on a bundle of finned tubes.

Danilova, G.N.; Dyundin, V.A.; Borishanskaya, A.V.; Soloviyov, A.G.; Vol'nykh, Y.A.; Kozyrev, A.A.

1990-01-01T23:59:59.000Z

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

A combined power and ejector refrigeration cycle for low temperature heat sources  

Science Conference Proceedings (OSTI)

A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature of 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)

Zheng, B.; Weng, Y.W. [School of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

2010-05-15T23:59:59.000Z

62

Heat pump with freeze-up prevention  

DOE Patents (OSTI)

What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid prevents freeze up of the second heat exchanger by keeping the temperature above the dew point; and, optionally, provides heat for efficient operation.

Ecker, Amir L. (Dallas, TX)

1981-01-01T23:59:59.000Z

63

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,...

64

COMPUTER DESIGN AND OPTIMIZATION OF CRYOGENIC REFRIGERATION SYSTEMS  

E-Print Network (OSTI)

One Stage Compressor Heat Exchanger Refrigeration Load XBLOne Stage Compressor Heat Exchanger Refrigeration Load XBLcondensers, surface heat exchangers, surface condensers,

green, M.A.

2011-01-01T23:59:59.000Z

65

HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL (HARDI)  

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

OE Framework Document and Stakeholder Meeting regarding the Enforcement of the updated Energy Conservation Standards for Air Conditioners, Furnaces and Heat Pumps.

66

Membrane-Based Absorption Refrigeration Systems: Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat  

Science Conference Proceedings (OSTI)

BEETIT Project: UFL is improving a refrigeration system that uses low quality heat to provide the energy needed to drive cooling. This system, known as absorption refrigeration system (ARS), typically consists of large coils that transfer heat. Unfortunately, these large heat exchanger coils are responsible for bulkiness and high cost of ARS. UFL is using new materials as well as system design innovations to develop nanoengineered membranes to allow for enhanced heat exchange that reduces bulkiness. UFL’s design allows for compact, cheaper and more reliable use of ARS that use solar or waste heat.

None

2010-09-01T23:59:59.000Z

67

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

68

Detailed CFD modelling of open refrigerated display cabinets  

Science Conference Proceedings (OSTI)

A comprehensive and detailed computational fluid dynamics (CFDs) modelling of air flow and heat transfer in an open refrigerated display cabinet (ORDC) is performed in this study. The physical-mathematical model considers the flow through the internal ...

Pedro Dinis Gaspar; L. C. Carrilho Gonçalves; R. A. Pitarma

2012-01-01T23:59:59.000Z

69

The Stirling alternative. Power systems, refrigerants and heat pumps  

SciTech Connect

This book provides an up-to-date reference on the technology, history, and practical applications of Stirling engines, including recent developments in the field and a convenient survey of the Stirling engine literature. The topics of the book include: fundamentals of Stirling technology, definition and terminology, thermodynamic laws and cycles: some elementary considerations, the Stirling cycle, practical regenerative cycle, theoretical aspects and computer simulation of Stirling machines, mechanical arrangements, control systems, heat exchangers, performance characteristics, working fluids, applications of Stirling machines, advantages of Stirling machines, disadvantages of Stirling machines, Stirling versus internal combustion engines, Stirling versus Rankine engines, applications for Stirling machines, Stirling power systems, the literature and sources of supply, the literature of Stirling engines, and the literature of cryocoolers.

Walker, G.; Reader, G.; Fauvel, O.R.; Bingham, E.R. (Univ. of Calgary, Alberta (Canada))

1993-01-01T23:59:59.000Z

70

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

71

Heat Transfer and Pressure Drop During Condensation of Refrigerants in Microchannels .  

E-Print Network (OSTI)

??Two-phase flow, boiling, and condensation in microchannels have received considerable attention in the recent past due to the growing interest in the high heat fluxes… (more)

Agarwal, Akhil

2006-01-01T23:59:59.000Z

72

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

73

How refrigeration, heating, ventilation, and air conditioning service technicians learn from troubleshooting (Dissertation ABstract)  

E-Print Network (OSTI)

The purpose of this study was to understand how refrigeration, heating, ventilation, and air conditioning (RHVAC) service technicians (techs) learned from troubleshooting. This understanding resulted in instructional and curricular strategies designed to help community colleges prepare vocational students to learn more effectively from informal workplace learning. RHVAC techs were studied because they increasingly learn their trade skills through a combination of formal schooling and informal workplace learning, though many still learn their trade almost exclusively in the workplace. Even those with formal training require considerable workplace experience to become fully competent. Troubleshooting is a major job function for RHVAC service techs, and troubleshooting

Denis F. H. Green

2006-01-01T23:59:59.000Z

74

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 ÎŒcal/gm-yr, which is slightly

75

Energy Efficiency Evaluation of Refrigeration Technologies in Combined Cooling, Heating and Power Systems  

E-Print Network (OSTI)

With development of absorption refrigeration technology, the cooling requirement can be met using various optional refrigeration technologies in a CCHP system, including compression refrigeration, steam double-effect absorption refrigeration, steam single-effect absorption refrigeration, flue gas absorption refrigeration and hot water absorption refrigeration, etc. As a universal criterion, the COP coefficient cannot reflect the difference in availability of driving energy for different chillers. Exergy efficiency of optional chillers in CCHP system was analyzed and compared, which can be regarded as an important reference criterion in comparison of energy efficiency. Furthermore, a new index, relative electricity saving ratio, was put forward for evaluating end energy efficiency of all kinds of chillers in a CCHP system, which indicates actual energy or electricity saving ratio for different absorption chillers with various parameters in contrast to the reference electricity-driven refrigeration scheme.

Zuo, Z.; Hu, W.

2006-01-01T23:59:59.000Z

76

Energy conservation for household refrigerators and water heaters  

Science Conference Proceedings (OSTI)

An energy conservation arrangement for household refrigerators and water heaters, in which the source of cold water to the hot water heater is divided and part is caused to flow through and be warmed in the condenser of the refrigerator. The warmed water is then further heated in the oil cooling loop of the refrigerator compressor, and proceeds then to the top of the hot water tank.

Speicher, T. L.

1984-12-11T23:59:59.000Z

77

Chemically assisted mechanical refrigeration process  

DOE Patents (OSTI)

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Vobach, A.R.

1987-11-24T23:59:59.000Z

78

Chemically assisted mechanical refrigeration process  

DOE Patents (OSTI)

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing he evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

Vobach, Arnold R. (6006 Allentown Dr., Spring, TX 77379)

1987-01-01T23:59:59.000Z

79

Chemically assisted mechanical refrigeration process  

DOE Patents (OSTI)

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer (11) at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer (11) to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator (10) to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator.

Vobach, Arnold R. (6006 Allentown Dr., Spring, TX 77389)

1987-01-01T23:59:59.000Z

80

Chemically assisted mechanical refrigeration process  

DOE Patents (OSTI)

There is provided a chemically assisted mechanical refrigeration process including the steps of: mechanically compressing a refrigerant stream which includes vaporized refrigerant; contacting the refrigerant with a solvent in a mixer at a pressure sufficient to promote substantial dissolving of the refrigerant in the solvent in the mixer to form a refrigerant-solvent solution while concurrently placing the solution in heat exchange relation with a working medium to transfer energy to the working medium, said refrigerant-solvent solution exhibiting a negative deviation from Raoult's Law; reducing the pressure over the refrigerant-solvent solution in an evaporator to allow the refrigerant to vaporize and substantially separate from the solvent while concurrently placing the evolving refrigerant-solvent solution in heat exchange relation with a working medium to remove energy from the working medium to thereby form a refrigerant stream and a solvent stream; and passing the solvent and refrigerant stream from the evaporator. 5 figs.

Vobach, A.R.

1987-06-23T23:59:59.000Z

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

Improvement of xenon purification system using a combination of a pulse tube refrigerator and a coaxial heat exchanger  

E-Print Network (OSTI)

We have developed a compact cryogenic system with a pulse tube refrigerator and a coaxial heat exchanger. This liquefaction-purification system not only saves the cooling power used to reach high gaseous recirculation rate, but also reduces the impurity level with high speed. The heat exchanger operates with an efficiency of 99%, which indicates the possibility for fast xenon gas recirculation in a highpressurized large-scale xenon storage with much less thermal losses.

Chen, Wan-Ting; Cussonneau, J -P; Donnard, J; Duval, S; Lemaire, O; Calloch, M Le; Ray, P Le; Mohamad-Hadi, A -F; Morteau, E; Oger, T; Scotto-Lavina, L; Stutzmann, J -S; Thers, D; Briend, P; Haruyama, T; Mihara, S; Tauchi, T

2012-01-01T23:59:59.000Z

82

Refinery Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP) Recovers LPG's and Gasoline, Saves Energy, and Reduces Air Pollution  

E-Print Network (OSTI)

A first-of-its-kind Waste Heat Ammonia Absorption Refrigeration Plant (WHAARP™) was installed by Planetec Utility Services Co., Inc. in partnership with Energy Concepts Co. at Ultramar Diamond Shamrock's 30,000 barrel per day refinery in Denver, Colorado. The refrigeration unit is designed to provide refrigeration for two process units at the refinery while utilizing waste heat as the energy source. The added refrigeration capacity benefits the refinery by recovering salable products, debottlenecking process units, avoiding additional electrical demand, and reducing the refinery Energy Intensity Index. In addition, the WHAARP unit lowers air pollutant emissions by reducing excess fuel gas that is combusted in the refinery flare. A comprehensive utility and process efficiency Master Plan developed for the Denver refinery by Planetec provided the necessary platform for implementing this distinctive project. The $2.3 million WHAARP system was paid for in part by a $760,000 grant from the U.S. Department of Energy, as part of their "Industry of the Future Program". Total combined benefits are projected to be approximately $1 million/year with a 1.6 year simple payback including the grant funding.

Brant, B.; Brueske, S.; Erickson, D.; Papar, R.

1998-04-01T23:59:59.000Z

83

Comment submitted by the Air Conditioning, Heating and Refrigeration Institute (AHRI) regarding the Energy Star Verification Testing Program  

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

AHRI Comments - DOE Verification Testing in Support of Energy Star AHRI Comments - DOE Verification Testing in Support of Energy Star May 9, 2011 P a g e | 1 May 9, 2010 Ms. Ashley Armstrong U.S. Department of Energy 1000 Independence Avenue, SW Washington, DC 20585 RE: DOE Verification Testing in Support of Energy Star Dear Ms. Armstrong: I am writing on behalf of the Air Conditioning, Heating and Refrigeration Institute (AHRI) to address the proposed DOE requirements for verification testing in support of the Energy Star program. AHRI is the trade association representing manufacturers of heating, cooling, and commercial refrigeration equipment. More than 300 members strong, AHRI is an internationally recognized advocate for the industry, and develops standards for and certifies the performance of many of the

84

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

85

Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus  

E-Print Network (OSTI)

As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new module is developed and the energy usage of the VRF system is investigated. This paper compares the energy consumption of the VRF system with that of two conventional air-conditioning systems, namely, the variable air volume (VAV) system and the fan-coil plus fresh air (FPFA) system. A generic office building is used to accommodate the different types of heating, ventilating, and air conditioning (HVAC) systems. Our objective is to examine the energy consumption of the VRF system applied to office buildings and make suggestions for evaluating and making decisions on HVAC systems in the early stages of building design. Simulation results show that the energy-saving potential of the VRF system is expected to achieve 22.2 percent and 11.7 percent, compared to the VAV system and the FPFA system, respectively. An energy-usage breakdown of electricity end-users in various systems is also presented.

Zhou, Y.; Wu, J.; Wang, R.; Shiochi, S.

2006-01-01T23:59:59.000Z

86

Large HVAC Codes and Standards Update 2000: American Society of Heating, Refrigerating and Air-Conditioning Engineers  

Science Conference Proceedings (OSTI)

This report documents EPRI activities in the year 2000 related to building codes and standards. The following activities are covered: attendance at the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) meetings and participation in technical committee and subcommittee meetings related to ASHRAE Standard 90.l; review of relevant U.S Department of Energy (DOE) appliance standards; review of developments of other building energy code organizations; and participation in the E...

2000-12-13T23:59:59.000Z

87

Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration  

E-Print Network (OSTI)

) and gives it off at higher ail.asp?article temperature (and pressure) and gives it off at higher temperature or no pressure changes Coolant for an engine: e:http://www 8.11.2012Ă?bo Akademi Univ - Thermal and Flow Engineering - Piispankatu 8, 20500 Turku 32/64 pressure changes. Coolant for an engine: not a refrigerant

Zevenhoven, Ron

88

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

89

High temperature refrigerator  

SciTech Connect

A high temperature magnetic refrigerator which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle said working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot.

Steyert, Jr., William A. (Los Alamos, NM)

1978-01-01T23:59:59.000Z

90

Candidate chemical systems for air cooled, solar powered, absorption air conditioner design. Part II. Solid absorbents, high latent heat refrigerants  

DOE Green Energy (OSTI)

Work done in attempting to qualify absorption refrigeration systems based on refrigerants with intermediate latent heats of vaporization is summarized. In practice, these comprise methanol, ammonia, and methylamine. A wide variety of organic substances, salts, and mixtures were evaluated in as systematic a manner as possible. Several systems of interest are described. The system, LiClO/sub 3/--LiBr--H/sub 2/O, is a good back up system to our first choice of an antifreeze additive system, and thermodynamically promising but subject to some inconvenient materials limitations. The system, LiBr/ZnBr/sub 2/--methanol, is thermodynamically promising but requires additional kinetic qualification. Chemical stability of the system, LiCNS--ammonia/methylamine with various other third components, does not appear to be adequate for a long-lived system.

Biermann, W. J.

1978-04-01T23:59:59.000Z

91

Heat pump system  

DOE Patents (OSTI)

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

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

1982-01-01T23:59:59.000Z

92

Heat pump system  

DOE Patents (OSTI)

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

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

1979-01-01T23:59:59.000Z

93

The Impact of Charge on Performance of an Air-to-Air Heat Pump for R22 and Three Binary Blends of Refrigerants 32 and 134a  

E-Print Network (OSTI)

An experimental study was conducted in which the performance of three blends of R134a and R32 were compared to R22. The effect of refrigerant charge and the size of expansion device on the performance of these refrigerants in an air-to-air heat pump operating in the air-conditioning mode was quantified. All tests were conducted according to ASHRAE Standard 116 (1983). The mixtures consisted of 60%/40%, 70%/30% and 80%/20% ratios by mass of R134a and R32. Charge levels of 5, 5.45, 5.90 and 6.00 kilograms (11, 12, 13 and 14 pounds) were tested. At each charge level, outdoor room conditions of 27.8°C, 35.0°C and 40.6°C (82°F, 95°F and 105°F) were tested. For each combination of charge level and outdoor room temperature, orifice diameters of 1.64, 1.78, 1.96 and 2.07 millimeters (0.0645, 0.0700, 0.0770 and 0.0815 inches) were tested. Three variables were used to quantify refrigerant performance: total capacity, total electrical power consumption and coefficient of performance (COP). Several other variables such as mass flow rate, compressor suction pressures and differential pressures were also used to determine system characteristics. The performance of the three mixtures was not as good as the R22. The capacities were between 7 and 17% lower than R22. The energy efficiency ratios were IV within three percent in some cases but the corresponding capacities at these EERs were more than 12% lower than the R22 base case. The best results for a mixture was the 60/40 blend. The capacity was 7.3% lower than the base case and the EER was 8.5% lower.

Robinson, J. H.

1993-08-01T23:59:59.000Z

94

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

95

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

96

Indoor unit for electric heat pump  

DOE Patents (OSTI)

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

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

1984-05-22T23:59:59.000Z

97

Frost sensor for use in defrost controls for refrigeration  

DOE Patents (OSTI)

An apparatus and method for measuring the total thermal resistance to heat flow from the air to the evaporative cooler fins of a refrigeration system. The apparatus is a frost sensor that measures the reduction in heat flow due to the added thermal resistance of ice (reduced conduction) as well as the reduction in heat flow due to the blockage of airflow (reduced convection) from excessive ice formation. The sensor triggers a defrost cycle when needed, instead of on a timed interval. The invention is also a method for control of frost in a system that transfers heat from air to a refrigerant along a thermal path. The method involves measuring the thermal conductivity of the thermal path from the air to the refrigerant, recognizing a reduction in thermal conductivity due to the thermal insulation effect of the frost and due to the loss of airflow from excessive ice formation; and controlling the defrosting of the system.

French, Patrick D. (ADA Technologies, Inc. 8100 Shaffer Pkwy., Suite 130, Littleton, CO 80127-4107); Butz, James R. (ADA Technologies, Inc. 8100 Shaffer Pkwy., Suite 130, Littleton, CO 80127-4107); Veatch, Bradley D. (ADA Technologies, Inc. 8100 Shaffer Pkwy., Suite 130, Littleton, CO 80127-4107); O' Connor, Michael W. (ADA Technologies, Inc. 8100 Shaffer Pkwy., Suite 130, Littleton, CO 80127-4107)

2002-01-01T23:59:59.000Z

98

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

99

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

100

Spray generators for absorption refrigeration systems  

DOE Patents (OSTI)

A spray generator for an absorption refrigeration system that includes a heat exchanger comprised of a multiplicity of variably spaced heat exchange tubes. The tubes are spaced close together near the top of the heat exchanger and spaced more widely apart near the bottom of the heat exchanger. Dilute absorbent solution is sprayed down through the heat exchanger. The close nesting of the tubes in the top portion of the heat exchanger retards liquid flow and aids heating of the solution. The wide spacing of the tubes in the lower section of the heat exchanger facilitate vapor flow out of the heat exchanger and eliminates liquid "blow-off". The top tubes are covered by a baffle to prevent the liquid solution from splashing out of the heat exchanger off of these top tubes.

Sibley, Howard W. (Baldwinsville, NY)

1979-06-19T23:59:59.000Z

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

Solar powered refrigeration apparatus  

SciTech Connect

Solar powered refrigeration apparatus is disclosed in which an absorption refrigeration system is operated directly by solar energy. One end of a heat pipe is thermally connected to the boiler of the absorption refrigeration system, and a solar collector is thermally coupled to the other remote end of the heat pipe. The heat pipe is a sealed, evacuated metal tube partially filled with water. The solar collector is a double walled glass vacuum tube with a central axial opening for accommodating the remote end of the heat pipe. Heat energy collected by the solar collector boils the water in the heat pipe to subsequently condense in the area of the boiler thus transferring heat energy along the heat pipe to the boiler. The heat pipe is installed sloping downwardly away from the boiler to permit the return of condensate down the pipe to the solar collector area thus permitting continuous operation.

Theakston, F.H.

1982-12-07T23:59:59.000Z

102

Low-temperature magnetic refrigerator  

DOE Patents (OSTI)

The invention relates to magnetic refrigeration and more particularly to low temperature refrigeration between about 4 and about 20 K, with an apparatus and method utilizing a belt of magnetic material passed in and out of a magnetic field with heat exchangers within and outside the field operably disposed to accomplish refrigeration.

Barclay, J.A.

1983-05-26T23:59:59.000Z

103

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

104

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

105

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

106

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

107

Memorandum To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) From: JONATHAN MELCHI, HEATING, AIR-CONDITIONING AND REFRIGERATION  

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

To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) To: GENERAL COUNSEL, DEPARTMENT OF ENERGY (DOE) From: JONATHAN MELCHI, HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL (HARDI) Date: 1/12/2012 Subject: EX PARTE COMMUNICATION MEMO DOE ATTENDEES: Ashley Armstrong, John Cymbalsky, David Case, Laura Barhydt HARDI ATTENDEES: Talbot Gee, Jonathan Melchi AREAS OF DISCUSSION: DOE Framework Document and Stakeholder Meeting regarding the Enforcement of the updated Energy Conservation Standards for Air Conditioners, Furnaces and Heat Pumps. The meeting took place on Thursday January 5 th , 2012 from 2pm to 3-pm. The following topics were discussed. 1.) Sell-Through. HARDI asked for clarification on the DOE's notation on the Framework Document

108

Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report  

DOE Green Energy (OSTI)

Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.

Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

1980-03-01T23:59:59.000Z

109

Refrigerant Phase-Change Stirling-Cycle Solar Power Towers  

Science Conference Proceedings (OSTI)

This paper firstly introduces the principles of Refrigerant Phase-Change Stirling-Cycle solar power towers This heat engines use solar reservoire. When the refrigerant in an engine cylinder absorbs heat from high-temperature heat sources, refrigerant ... Keywords: refrigerant phase-change cycle, heat engines, solar power tower, finite-time thermodynamics

Dezhong Huang

2011-01-01T23:59:59.000Z

110

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

111

Advanced control strategies for heating, ventilation, air-conditioning, and refrigeration systems—An overview: Part I: Hard control  

SciTech Connect

A chronological overview of the advanced control strategies for heating, ventilation, air-conditioning, and refrigeration (HVAC&R) is presented in this article. The overview focuses on hard-computing or control techniques, such as proportional-integral-derivative, optimal, nonlinear, adaptive, and robust; soft-computing or control techniques, such as neural networks, fuzzy logic, genetic algorithms; and on the fusion or hybrid of hard- and soft-control techniques. Thus, it is to be noted that the terminology “hard” and “soft” computing/control has nothing to do with the “hardware” and “software” that is being generally used. Part I of a two-part series focuses on hard-control strategies, and Part II focuses on softand fusion-control in addition to some future directions in HVAC&R research. This overview is not intended to be an exhaustive survey on this topic, and any omission of other works is purely unintentional.

D. Subbaram Naidu; Craig G. Rieger

2011-02-01T23:59:59.000Z

112

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

113

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

114

Opportunities for Energy Efficiency and Automated Demand Response in Industrial Refrigerated Warehouses in California  

E-Print Network (OSTI)

system. The refrigeration system design involves sizing ofDesign Essentials for Refrigerated Storage Facilities, American Society for Heating Refrigeration anddesign considerations are mostly related to wall and roof types, shell insulation, and the refrigeration

Lekov, Alex

2009-01-01T23:59:59.000Z

115

Date | 1Refrigeration and Air Conditioning EMA Education and Training Date | 2Refrigeration and Air Conditioning EMA Education and Training  

E-Print Network (OSTI)

Date | 1Refrigeration and Air Conditioning EMA Education and Training #12;Date | 2Refrigeration Flow Coil Design etc. Finger Print Relationship Every evaporator is unique Unstable Region * = examples

Oak Ridge National Laboratory

116

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

117

Method and apparatus for desuperheating refrigerant  

DOE Patents (OSTI)

The present invention is an apparatus and method for de-superheating a primary refrigerant leaving a compressor wherein a secondary refrigerant is used between the primary refrigerant to be de-superheated. Reject heat is advantageously used for heat reclaim.

Zess, James A. (Kelso, WA); Drost, M. Kevin (Richland, WA); Call, Charles J. (Richland, WA)

1997-01-01T23:59:59.000Z

118

Chapter 19. Heat Engines and Refrigerators That's not smoke. It's clouds  

E-Print Network (OSTI)

the cooling towers around a large power plant. The power plant is generating electricity by turning heat Copyright © 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. electricity by turning heat fuel, into another, such as work. · Chapters 17 and 18 established two laws of thermodynamics Copyright

Dhamala, Mukesh

119

Improving Industrial Refrigeration System Efficiency - Actual Applications  

E-Print Network (OSTI)

This paper discusses actual design and modifications for increased system efficiency and includes reduced chilled liquid flow during part load operation, reduced condensing and increased evaporator temperatures for reduced system head, thermosiphon cycle cooling during winter operation, compressor intercooling, direct refrigeration vs. brine cooling, insulation of cold piping to reduce heat gain, multiple screw compressors for improved part load operation, evaporative condensers for reduced system head and pumping energy, and using high efficiency motors.

White, T. L.

1980-01-01T23:59:59.000Z

120

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

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

122

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

123

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

124

Measured Effects of Retrofits - A Refrigerant Oil Additive and a Condenser Spray Device - On the Cooling Performance of a Heat Pump  

E-Print Network (OSTI)

A 15-year old, 3-ton single package air-to-air heat pump was tested in laboratory environmental chambers simulating indoor and outdoor conditions. After documenting initial performance, the unit was retrofitted with a prototype condenser water-spray device and retested. Results at standard AM cooling rating conditions (95°F outdoor dry bulb and 80167 OF indoor dry bulb/wet bulb temperatures) showed the capacity increased by about 7%, and the electric power demand dropped by about 8%, resulting in a steady-state EER increase of 17%. Suction and discharge pressures were reduced by 7 and 37 psi, respectively. A refrigerant oil additive formulated to enhance refrigerant-side heat transfer was added at a dose of one ounce per ton of rated capacity. and the unit was tested for several days at the same 95°F outdoor conditions and showed essentially no increase in capacity, and a slight 3% increase in steady-state EER. Adding more additive lowered the EER slightly. Suction and discharge pressures were essentially unchanged. Our short-term testing showed that the condenser-spray device was effective in increasing the cooling capacity and lowering the electrical demand on an old and relatively inefficient heat pump, but the refrigerant additive had little effect on the cooling performance of our unit Sprayer issues to be resolved include the effect of a sprayer on a new, high-efficiency air conditioner/heat pump, reliable long-term operation, and economics.

Levins, W. P.; Sand, J. R.; Baxter, V. D.; Linkous, R. S.

1996-01-01T23:59:59.000Z

125

Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration  

E-Print Network (OSTI)

of the tower An (earlier) alternative is to use a spray pond to cool water; disadvantages are a large areaRefrigerationRefrigerationRefrigeration coursecourse # 424503.0# 424503.0 v.v. 20122012 7. Air conditioning, cooling towersg, g Ron Zevenhoven Ă?Ă?bo, is the hi htemperature at which condensation begins when air is cooled at constant pressurecooled

Zevenhoven, Ron

126

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

127

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...

128

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...

129

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. ...

130

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...

131

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

132

Heat extraction and refrigeration (HEAR) system. Phase I final progress report. [Restaurant kitchens  

Science Conference Proceedings (OSTI)

Testing indicates that heat energy available to be recaptured grossly exceeds the capacity of the 1.5 ton medium temperature Freon 12 compressor being utilized. The unit produced 50 pounds of suction pressure with the damper (Figure 4) open and exceeded compressor operational limits with the damper closed. This indicates that the current compressor could be replaced by one of 5 ton capacity since current estimates indicate that 60,000 Btu's are available for recovery. This could be divided between space heating and water heating as required by using separate condensers. There were no real surprises in the feasibility model construction and test phase, and the validity of the assumptions made in the original project description have been established. That is, it has been demonstrated that it is feasible to extract heat from the kitchen exhaust duct in a restaurant and keep the heat pump evaporator clean. It is concluded that work done under this $10,000 grant demonstrated the technical feasibility of the HEAR System. However, additional funding (our original proposal called for a $47,000 grant) would be required to economically evaluate the benefit realized and to advance the HEAR System design to a workable prototype stage.

Venable, B.M.

1983-01-01T23:59:59.000Z

133

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

134

Compact acoustic refrigerator  

DOE Patents (OSTI)

This invention is comprised of a compact acoustic refrigeration system that actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment.

Bennett, G.A.

1991-12-31T23:59:59.000Z

135

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits, in a borehole environment. An acoustic engine includes first thermodynamic elements for generating a standing acoustic wave in a selected medium. An acoustic refrigerator includes second thermodynamic elements located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements and a relatively hot temperature at a second end of the second thermodynamic elements. A resonator volume cooperates with the first and second thermodynamic elements to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements, first heat pipes transfer heat from the heat load to the second thermodynamic elements and second heat pipes transfer heat from first and second thermodynamic elements to the borehole environment. 18 figs.

Bennett, G.A.

1992-11-24T23:59:59.000Z

136

Compact acoustic refrigerator  

DOE Patents (OSTI)

A compact acoustic refrigeration system actively cools components, e.g., electrical circuits (22), in a borehole environment. An acoustic engine (12, 14) includes first thermodynamic elements (12) for generating a standing acoustic wave in a selected medium. An acoustic refrigerator (16, 26, 28) includes second thermodynamic elements (16) located in the standing wave for generating a relatively cold temperature at a first end of the second thermodynamic elements (16) and a relatively hot temperature at a second end of the second thermodynamic elements (16). A resonator volume (18) cooperates with the first and second thermodynamic elements (12, 16) to support the standing wave. To accommodate the high heat fluxes required for heat transfer to/from the first and second thermodynamic elements (12, 16), first heat pipes (24, 26) transfer heat from the heat load (22) to the second thermodynamic elements (16) and second heat pipes (28, 32) transfer heat from first and second thermodynamic elements (12, 16) to the borehole environment.

Bennett, Gloria A. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

137

Adsorption Refrigeration System  

SciTech Connect

Adsorption refrigeration is an environmentally friendly cooling technology which could be driven by recovered waste heat or low-grade heat such as solar energy. In comparison with absorption system, an adsorption system has no problems such as corrosion at high temperature and salt crystallization. In comparison with vapor compression refrigeration system, it has the advantages of simple control, no moving parts and less noise. This paper introduces the basic theory of adsorption cycle as well as the advanced adsorption cycles such as heat and mass recovery cycle, thermal wave cycle and convection thermal wave cycle. The types, characteristics, advantages and drawbacks of different adsorbents used in adsorption refrigeration systems are also summarized. This article will increase the awareness of this emerging cooling technology among the HVAC engineers and help them select appropriate adsorption systems in energy-efficient building design.

Wang, Kai [ORNL; Vineyard, Edward Allan [ORNL

2011-01-01T23:59:59.000Z

138

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

139

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

140

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

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

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

142

NICE3: Industrial Refrigeration System  

SciTech Connect

Energy Concepts has developed an absorption-augmented system as a cost-effective means of achieving more cooling capacity with a substantial reduction in energy consumption and greenhouse gas emissions for industrial refrigeration. It cuts fuel consumption by 30% by combining an internal combustion engine with a mechanical compression refrigeration system and an absorption refrigeration system. The absorption system is powered by engine waste heat. Conventional industrial refrigeration uses mechanical vapor compression, powered by electric motors, which results in higher energy costs. By the year 2010, the new system could cut fuel consumption by 19 trillion Btu and greenhouse emissions by more than 1 million tons per year.

Simon, P.

1999-09-29T23:59:59.000Z

143

Floating Loop System For Cooling Integrated Motors And Inverters Using Hot Liquid Refrigerant  

DOE Patents (OSTI)

A floating loop vehicle component cooling and air-conditioning system having at least one compressor for compressing cool vapor refrigerant into hot vapor refrigerant; at least one condenser for condensing the hot vapor refrigerant into hot liquid refrigerant by exchanging heat with outdoor air; at least one floating loop component cooling device for evaporating the hot liquid refrigerant into hot vapor refrigerant; at least one expansion device for expanding the hot liquid refrigerant into cool liquid refrigerant; at least one air conditioning evaporator for evaporating the cool liquid refrigerant into cool vapor refrigerant by exchanging heat with indoor air; and piping for interconnecting components of the cooling and air conditioning system.

Hsu, John S [Oak Ridge, TN; Ayers, Curtis W [Kingston, TN; Coomer, Chester [Knoxville, TN; Marlino, Laura D [Oak Ridge, TN

2006-02-07T23:59:59.000Z

144

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

145

Frontiers in thermoacoustic refrigeration and mixture separation  

E-Print Network (OSTI)

pulse-tube refrigerator shown in Figure 1 dissipates acoustic power by design because power must flowFrontiers in thermoacoustic refrigeration and mixture separation S. Backhaus1 , D. Geller2 , B oscillating thermodynamics in a gas in a sealed system. Since then, many related engines and refrigerators

146

Heat transfer characteristics of a three-phase volume boiling direct contact heat exchanger  

DOE Green Energy (OSTI)

The advantages of direct contact heat transfer over heat transfer utilizing conventional metallic heat exchangers are listed. The performance characteristics of a three-phase direct contact heat exchanger in near counterflow operation were evaluated using water as the continuous phase fluid and refrigerant 113 as the dispersed phase fluid. Conclusions are drawn from the results having to do with refrigerant injection technique, vessel operating height, mass flow rate of refrigerant, water inlet temperature, operation at pinch point temperature differences below 13 to 20/sup 0/C, and operation with a dispersed phase fluid less dense than water. (MHR)

Blair, C.K.; Boehm, R.F.; Jacobs, H.R.

1976-03-01T23:59:59.000Z

147

A New Absorption Cycle: The Single-Effect Regenerative Absoprtion Refrigeration Cycle  

E-Print Network (OSTI)

REGENERATIVE ABSORPTION REFRIGERATION CYCLE ABSTRACT A new absorption cycle , using heat as the energy

Dao, K.

2011-01-01T23:59:59.000Z

148

Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration  

E-Print Network (OSTI)

.100.110.2 Typical refrigerant: R-134a, R- 600a and other hydrocarbons cture:http://1 Air-cooled condensing unit ncompressioisentropicwithprocess isentropicc realc t COP COP · The diagram gives some efficiency data from commercial vapour- 6 some efficiency data from commercial vapour compression refrigerators (T1 = TH, T2 = TL, data from 1976

Zevenhoven, Ron

149

Magnetic refrigeration apparatus and method  

SciTech Connect

The disclosure relates to refrigeration through magnetizing and demagnitizing a body by rotating it within a magnetic field. Internal and external heat exchange fluids and in one embodiment, a regenerator, are used.

Barclay, John A. (Los Alamos, NM); Overton, Jr., William C. (Los Alamos, NM); Stewart, Walter F. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

150

Dual-circuit, multiple-effect refrigeration system and method  

DOE Patents (OSTI)

A dual circuit absorption refrigeration system comprising a high temperature single-effect refrigeration loop and a lower temperature double-effect refrigeration loop separate from one another and provided with a double-condenser coupling therebetween. The high temperature condenser of the single-effect refrigeration loop is double coupled to both of the generators in the double-effect refrigeration loop to improve internal heat recovery and a heat and mass transfer additive such as 2-ethyl-1-hexanol is used in the lower temperature double-effect refrigeration loop to improve the performance of the absorber in the double-effect refrigeration loop.

DeVault, Robert C. (Knoxville, TN)

1995-01-01T23:59:59.000Z

151

Countercurrent flow absorber and desorber  

DOE Patents (OSTI)

Countercurrent flow absorber and desorber devices are provided for use in absorption cycle refrigeration systems and thermal boosting systems. The devices have increased residence time and surface area resulting in improved heat and mass transfer characteristics. The apparatuses may be incorporated into open cycle thermal boosting systems in which steam serves both as the refrigerant vapor which is supplied to the absorber section and as the supply of heat to drive the desorber section of the system. 9 figs.

Wilkinson, W.H.

1984-10-16T23:59:59.000Z

152

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

153

Heat pump system  

DOE Patents (OSTI)

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

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

1983-01-01T23:59:59.000Z

154

Heat pump system  

DOE Patents (OSTI)

An air heating and cooling system for a building includes an expansion type refrigeration circuit and a vapor power circuit. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The vapor power circuit includes two heat exchangers, one of which is disposed in series air flow relationship with the indoor refrigeration circuit heat exchanger and the other of which is disposed in series air flow relationship with the outdoor refrigeration circuit heat exchanger. Fans powered by electricity generated by a vapor power circuit alternator circulate indoor air through the two indoor heat exchangers and circulate outside air through the two outdoor heat exchangers. The system is assembled as a single roof top unit, with a vapor power generator and turbine and compressor thermally insulated from the heat exchangers, and with the indoor heat exchangers thermally insulated from the outdoor heat exchangers.

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

1977-01-01T23:59:59.000Z

155

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

156

US Department of Energys Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment  

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

US Department of Energy's Regulatory Negotiations Convening on US Department of Energy's Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment Public Information for Convening Interviews I. What are the substantive issues DOE seeks to address? Strategies for grouping various basic models for purposes of certification; Identification of non-efficiency attributes, which do not impact the measured consumption of the equipment as tested by DOE's test procedure; The information that is certified to the Department; The timing of when the certification should be made relative to distribution in commerce; and Alterations to a basic model that would impact the certification.

157

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...

158

Roughness and surface material effects on nucleate boiling heat transfer from cylindrical surfaces to refrigerants R-134a and R-123  

SciTech Connect

This paper presents results of an experimental investigation carried out to determine the effects of the surface roughness of different materials on nucleate boiling heat transfer of refrigerants R-134a and R-123. Experiments have been performed over cylindrical surfaces of copper, brass and stainless steel. Surfaces have been treated by different methods in order to obtain an average roughness, Ra, varying from 0.03 {mu}m to 10.5 {mu}m. Boiling curves at different reduced pressures have been raised as part of the investigation. The obtained results have shown significant effects of the surface material, with brass being the best performing and stainless steel the worst. Polished surfaces seem to present slightly better performance than the sand paper roughened. Boiling on very rough surfaces presents a peculiar behavior characterized by good thermal performance at low heat fluxes, the performance deteriorating at high heat fluxes with respect to smoother surfaces. (author)

Jabardo, Jose M. Saiz [Escuela Politecnica Superior, Universidad de la Coruna, Mendizabal s/n Esteiro, 15403 Ferrol, Coruna (Spain); Ribatski, Gherhardt; Stelute, Elvio [Department of Mechanical Engineering, Escola de Engenharia de Sao Carlos (EESC), University of Sao Paulo (USP), Av. Trabalhador Saocarlense 400 Centro, 13566-590 Sao Carlos, SP (Brazil)

2009-04-15T23:59:59.000Z

159

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

160

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 "refrigerant flow heat" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

162

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

This invention is comprised of a cryogenic refrigerator which cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He/[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, G.W.; Kotsubo, V.Y.

1991-04-02T23:59:59.000Z

163

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of [sup 3]He in a single phase [sup 3]He-[sup 4]He solution. The [sup 3]He in superfluid [sup 4]He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid [sup 3]He at an initial concentration in superfluid [sup 4]He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of [sup 4]He while restricting passage of [sup 3]He. The [sup 3]He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs.

Swift, G.W.; Kotsubo, V.Y.

1992-12-22T23:59:59.000Z

164

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

This invention is comprised of a cryogenic refrigerator which cools a heat source by cyclically concentrating and diluting the amount of {sup 3}He in a single phase {sup 3}He/{sup 4}He solution. The {sup 3}He in superfluid {sup 4}He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid {sup 3}He at an initial concentration in superfluid {sup 4}He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of {sup 4}He while restricting passage of {sup 3}He. The {sup 3}He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, G.W.; Kotsubo, V.Y.

1991-04-02T23:59:59.000Z

165

Superfluid thermodynamic cycle refrigerator  

DOE Patents (OSTI)

A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Swift, Gregory W. (Santa Fe, NM); Kotsubo, Vincent Y. (La Canada, CA)

1992-01-01T23:59:59.000Z

166

Thermoacoustic refrigerator  

DOE Patents (OSTI)

A thermoacoustic device having a thermal stack made from a piece of porous material which provides a desirable ratio of thermoacoustic area to viscous area, which has a low resistance to flow, which minimizes acoustic streaming and which has a high specific heat and low thermal conductivity is disclosed. The thermal stack is easy and cheap to form and it can be formed in small sizes. Specifically, in one embodiment, a thermal stack which is formed by the natural structure of a porous material such as reticulated vitreous carbon is disclosed. The thermal stack is formed by machining a block of reticulated vitreous carbon into the required shape of the thermal stack. In a second embodiment, a micro-thermoacoustic device is disclosed which includes a thermal stack made of a piece of porous material such as reticulated vitreous carbon. In another embodiment, a heat exchanger is disclosed which is formed of a block of heat conductive open cell foam material.

Moss, William C. (San Mateo, CA)

1997-01-01T23:59:59.000Z

167

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

168

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

169

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,

170

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

171

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

172

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1989-01-01T23:59:59.000Z

173

Seven-effect absorption refrigeration  

DOE Patents (OSTI)

A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit. 1 fig.

DeVault, R.C.; Biermann, W.J.

1989-05-09T23:59:59.000Z

174

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

E-Print Network (OSTI)

Comparison of energy efficiency between variable refrigeranttheir superior energy efficiency. The variable refrigerantfew studies reporting the energy efficiency of VRF systems

Hong, Tainzhen

2010-01-01T23:59:59.000Z

175

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

176

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

177

List of Refrigerators Incentives | Open Energy Information  

Open Energy Info (EERE)

Refrigerators Incentives Refrigerators Incentives Jump to: navigation, search The following contains the list of 657 Refrigerators Incentives. CSV (rows 1-500) CSV (rows 501-657) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active AEP Ohio - Commercial Custom Project Rebate Program (Ohio) Utility Rebate Program Ohio Commercial Fed. Government Industrial Institutional Local Government Nonprofit Schools State Government Tribal Government Boilers Central Air conditioners Chillers Custom/Others pending approval Furnaces Heat pumps Heat recovery Lighting Lighting Controls/Sensors Processing and Manufacturing Equipment Refrigerators Yes AEP Ohio - Commercial Energy Efficiency Rebate Program (Ohio) Utility Rebate Program Ohio Commercial Fed. Government Industrial

178

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

179

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

180

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 "refrigerant flow heat" 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

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

182

The influence of return bends on the downstream pressure drop and condensation heat transfer in tubes  

E-Print Network (OSTI)

The influence of return bends on the downstream pressure drop and heat transfer coefficient of condensing refrigerant R-12 was studied experimentally. Flow patterns in glass return bends of 1/2 to 1 in. radius and 0.315 ...

Traviss, Donald P.

1971-01-01T23:59:59.000Z

183

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

184

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

185

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

186

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

187

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

188

Low-GWP Refrigerants Research Project | Department of Energy  

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

Emerging Technologies » Low-GWP Refrigerants Research Project Emerging Technologies » Low-GWP Refrigerants Research Project Low-GWP Refrigerants Research Project The U.S. Department of Energy is currently conducting research into low global warming potential (GWP) refrigerants. As concerns about climate change intensify, it is becoming increasingly clear that suitable low-GWP refrigerants will be needed for both new and existing residential and commercial heating, ventilation, air conditioning, and refrigeration (HVAC&R) equipment. Project Description This project seeks to develop alternative refrigerants for HVAC&R equipment. The overall environmental impacts of alternative refrigerants will be assessed using a life cycle climate performance model that accounts for direct emissions associated with refrigerant leaks and indirect

189

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect

Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.

Boeder, A; Zimm, C

2006-09-30T23:59:59.000Z

190

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

191

Heat pump system with selective space cooling  

DOE Patents (OSTI)

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve. 4 figs.

Pendergrass, J.C.

1997-05-13T23:59:59.000Z

192

Heat pump system with selective space cooling  

DOE Patents (OSTI)

A reversible heat pump provides multiple heating and cooling modes and includes a compressor, an evaporator and heat exchanger all interconnected and charged with refrigerant fluid. The heat exchanger includes tanks connected in series to the water supply and a condenser feed line with heat transfer sections connected in counterflow relationship. The heat pump has an accumulator and suction line for the refrigerant fluid upstream of the compressor. Sub-cool transfer tubes associated with the accumulator/suction line reclaim a portion of the heat from the heat exchanger. A reversing valve switches between heating/cooling modes. A first bypass is operative to direct the refrigerant fluid around the sub-cool transfer tubes in the space cooling only mode and during which an expansion valve is utilized upstream of the evaporator/indoor coil. A second bypass is provided around the expansion valve. A programmable microprocessor activates the first bypass in the cooling only mode and deactivates the second bypass, and vice-versa in the multiple heating modes for said heat exchanger. In the heating modes, the evaporator may include an auxiliary outdoor coil for direct supplemental heat dissipation into ambient air. In the multiple heating modes, the condensed refrigerant fluid is regulated by a flow control valve.

Pendergrass, Joseph C. (Gainesville, GA)

1997-01-01T23:59:59.000Z

193

Refrigerant directly cooled capacitors  

DOE Patents (OSTI)

The invention is a direct contact refrigerant cooling system using a refrigerant floating loop having a refrigerant and refrigeration devices. The cooling system has at least one hermetic container disposed in the refrigerant floating loop. The hermetic container has at least one electronic component selected from the group consisting of capacitors, power electronic switches and gating signal module. The refrigerant is in direct contact with the electronic component.

Hsu, John S. (Oak Ridge, TN); Seiber, Larry E. (Oak Ridge, TN); Marlino, Laura D. (Oak Ridge, TN); Ayers, Curtis W. (Kingston, TN)

2007-09-11T23:59:59.000Z

194

Bipolar pulse field for magnetic refrigeration  

DOE Patents (OSTI)

A magnetic refrigeration apparatus includes first and second steady state magnets, each having a field of substantially equal strength and opposite polarity, first and second bodies made of magnetocaloric material disposed respectively in the influence of the fields of the first and second steady state magnets, and a pulsed magnet, concentric with the first and second steady state magnets, and having a field which cycles between the fields of the first and second steady state magnets, thereby cyclically magnetizing and demagnetizing and thus heating and cooling the first and second bodies. Heat exchange apparatus of suitable design can be used to expose a working fluid to the first and second bodies of magnetocaloric material. A controller is provided to synchronize the flow of working fluid with the changing states of magnetization of the first and second bodies. 2 figs.

Lubell, M.S.

1994-10-25T23:59:59.000Z

195

Bubble Pump Design for Single Pressure Absorption Refrigeration Cycles  

E-Print Network (OSTI)

A model has been developed for the design and optimization of a small bubble pump to be used in a single pressure absorption refrigeration cycle to lift the working fluid mixture against gravity and overcome flow friction. This analytical model is developed from two-phase flow fundamentals and incorporates the design parameters of the bubble pump. Parametric studies are carried out and a design optimization for maximum efficiency is performed for various operating conditions. Optimum efficiency is defined as the liquid pumped per unit of bubble pump heat input. The results show the optimum bubble pump tube diameter over a range of operating conditions.

Sam V. Shelton; Susan White Stewart

2002-01-01T23:59:59.000Z

196

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

197

Comparison of Several Eco-Friendly Refrigeration Technologies  

E-Print Network (OSTI)

In this paper, the operation principles, thermodynamics characteristics, and technical practicability were compared between thermoelectric refrigeration, magnetic refrigeration and adsorption refrigeration. The TE refrigeration is the most well-developed, applicable and competitive technology. Three eco-friendly refrigeration systems are increasingly getting attention, especially in a day with increasingly energy and environmental crises. In summary, thermoelectric refrigeration possesses the following superiorities: a longer developmental period, more perfect techniques, increasing applications, a larger range of refrigerating capacity, and a better economic property in small refrigerating capacity. Thermoelectric refrigeration cannot be replaced in special fields, and its applications have received more and more attention in recovering waste heat. Magnetic refrigeration has been widely applied in lower temperature regions; its application in middle temperature regions is juvenile. In particular, there is no application of this technique in high temperature regions. Adsorption refrigeration is practical only in near room temperatures. Its advantage is that it can be used in some fields where conventional refrigeration cannot be applied, such as in the application of solar energy, geothermal energy, and other renewable energy, and the recovery of residual and waste heat.? Supported by the Young Foundation of Central South University of Forestry & Technology (06002A) The disadvantages are as follows: the cost is expensive, no practical technique is available at present, and thus, it possesses no general superiority versus other refrigeration technologies.

Tang, C.; Luo, Q.; Li, X.; Zhu, X.

2006-01-01T23:59:59.000Z

198

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

199

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

200

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

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

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

202

Well simulation using Refrigerant 114  

DOE Green Energy (OSTI)

A simple method for the investigation of thermodynamic (substance) similarity in the two-phase domain is introduced based on the assumptions of a simplified model fluid. According to this method, the investigation of the conditions for thermodynamic similarity between substances in the two-phase region reveals the important role the latent heat of evaporation (h/sub fg/) plays in the definition of the property scales. These greatly influence the dynamic and geometric similarity of the process under investigation. The introduction of the thermodynamic similarity property scales into the energy conservation equations for a certain process (e.g., flow up a geothermal well) brings forth a thermodynamic length scale and kinetic energy scale. Refrigerant 114 has been examined for similarity with water substance according to this method and found to be adequate for geothermal well simulation in the laboratory. Low pressures and temperatures and a substantial reduction of mass flow rates and geometric scales are a few of the advantages of using R114 for such experiments.

Nikitopoulos, D.E.; Dickinson, D.A.; DiPippo, R.; Maeder, P.F.

1984-06-01T23:59:59.000Z

203

Fluorescent refrigeration  

DOE Patents (OSTI)

Fluorescent refrigeration is based on selective radiative pumping, using substantially monochromatic radiation, of quantum excitations which are then endothermically redistributed to higher energies. Ultimately, the populated energy levels radiatively deexcite emitting, on the average, more radiant energy than was initially absorbed. The material utilized to accomplish the cooling must have dimensions such that the exciting radiation is strongly absorbed, but the fluorescence may exit the material through a significantly smaller optical pathlength. Optical fibers and mirrored glasses and crystals provide this requirement. 6 figs.

Epstein, R.I.; Edwards, B.C.; Buchwald, M.I.; Gosnell, T.R.

1995-09-05T23:59:59.000Z

204

Low-temperature magnetic refrigerator  

SciTech Connect

The disclosure is directed to a low temperature 4 to 20 K. refrigeration apparatus and method utilizing a ring of magnetic material moving through a magnetic field. Heat exchange is accomplished in and out of the magnetic field to appropriately utilize the device to execute Carnot and Stirling cycles.

Barclay, John A. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

205

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

206

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

207

ARTI refrigerant database  

Science Conference Proceedings (OSTI)

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Calm, J.M.

1996-07-01T23:59:59.000Z

208

ARTI refrigerant database  

Science Conference Proceedings (OSTI)

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilities access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)] [Calm (James M.), Great Falls, VA (United States)

1999-01-01T23:59:59.000Z

209

ARTI refrigerant database  

Science Conference Proceedings (OSTI)

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Calm, J.M.

1996-11-15T23:59:59.000Z

210

Elastic Metal Alloy Refrigerants: Thermoelastic Cooling  

SciTech Connect

BEETIT Project: UMD is developing an energy-efficient cooling system that eliminates the need for synthetic refrigerants that harm the environment. More than 90% of the cooling and refrigeration systems in the U.S. today use vapor compression systems which rely on liquid to vapor phase transformation of synthetic refrigerants to absorb or release heat. Thermoelastic cooling systems, however, use a solid-state material—an elastic shape memory metal alloy—as a refrigerant and a solid to solid phase transformation to absorb or release heat. UMD is developing and testing shape memory alloys and a cooling device that alternately absorbs or creates heat in much the same way as a vapor compression system, but with significantly less energy and a smaller operational footprint.

2010-10-01T23:59:59.000Z

211

Superinsulation in refrigerators and freezers  

SciTech Connect

The results presented here were obtained during Phase 4 of the first CRADA, which had the specific objective of determining the lifetime of superinsulations when installed in simulated refrigerator doors. The second CRADA was established to evaluate and test design concepts proposed to significantly reduce energy consumption in a refrigerator-freezer that is representative of approximately 60% of the US market. The stated goal of this CRADA is to demonstrate advanced technologies which reduce, by 50%, the 1993 National Appliance Energy Conservation Act (NAECA) standard energy consumption for a 20 ft{sup 3} (570 L) top-mount, automatic-defrost, refrigerator-freezer. For a unit this size, the goal translates to an energy consumption of 1.003 kWh/d. The general objective of the research is to facilitate the introduction of efficient appliances by demonstrating design changes that can be effectively incorporated into new products. In previous work on this project, a Phase 1 prototype refrigerator-freezer achieved an energy consumption of 1.413 kWh/d [Vineyard, et al., 1995]. Following discussions with an advisory group comprised of all the major refrigerator-freezer manufacturers, several options were considered for the Phase 2 effort, one of which was cabinet heat load reductions.

Vineyard, E.; Stovall, T.K.; Wilkes, K.E.; Childs, K.W.

1998-02-01T23:59:59.000Z

212

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

213

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

214

Convective flow of refrigerant (R-123) across a bank of micro pin fins Ali Kosar, Yoav Peles *  

E-Print Network (OSTI)

with the tube bundle (porous regions) and the free flow regions in the context of the homogenization techniques. Lellouche and B. A. Zolotar, "Mechanistic Model For Predicting Two-Phase Void Fraction For Water in Vertical

Peles, Yoav

215

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

216

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

217

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.

218

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

219

New Regenerative Cycle for Vapor Compression Refrigeration  

SciTech Connect

The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient of performance for geothermal heat pumps based on a new regenerative thermodynamic cycle as comparing to existing technology. In order to demonstrate the improved performance of the prototype, it will be compared to published parameters of commercially available geothermal heat pumps manufactured by US and foreign companies. Other objectives are to optimize the design parameters and to determine the economic viability of the new technology. Background (as stated in the proposal): The proposed technology closely relates to EERE mission by improving energy efficiency, bringing clean, reliable and affordable heating and cooling to the residential and commercial buildings and reducing greenhouse gases emission. It can provide the same amount of heating and cooling with considerably less use of electrical energy and consequently has a potential of reducing our nations dependence on foreign oil. The theoretical basis for the proposed thermodynamic cycle was previously developed and was originally called a dynamic equilibrium method. This theory considers the dynamic equations of state of the working fluid and proposes the methods for modification of T-S trajectories of adiabatic transformation by changing dynamic properties of gas, such as flow rate, speed and acceleration. The substance of this proposal is a thermodynamic cycle characterized by the regenerative use of the potential energy of two-phase flow expansion, which in traditional systems is lost in expansion valves. The essential new features of the process are: (1) The application of two-step throttling of the working fluid and two-step compression of its vapor phase. (2) Use of a compressor as the initial step compression and a jet device as a second step, where throttling and compression are combined. (3) Controlled ratio of a working fluid at the first and second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

Mark J. Bergander

2005-08-29T23:59:59.000Z

220

Refrigeration system having standing wave compressor  

DOE Patents (OSTI)

A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

Lucas, Timothy S. (Glen Allen, VA)

1992-01-01T23:59:59.000Z

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

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...

222

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

223

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

224

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

225

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

226

Control method for mixed refrigerant based natural gas liquefier  

DOE Patents (OSTI)

In a natural gas liquefaction system having a refrigerant storage circuit, a refrigerant circulation circuit in fluid communication with the refrigerant storage circuit, and a natural gas liquefaction circuit in thermal communication with the refrigerant circulation circuit, a method for liquefaction of natural gas in which pressure in the refrigerant circulation circuit is adjusted to below about 175 psig by exchange of refrigerant with the refrigerant storage circuit. A variable speed motor is started whereby operation of a compressor is initiated. The compressor is operated at full discharge capacity. Operation of an expansion valve is initiated whereby suction pressure at the suction pressure port of the compressor is maintained below about 30 psig and discharge pressure at the discharge pressure port of the compressor is maintained below about 350 psig. Refrigerant vapor is introduced from the refrigerant holding tank into the refrigerant circulation circuit until the suction pressure is reduced to below about 15 psig, after which flow of the refrigerant vapor from the refrigerant holding tank is terminated. Natural gas is then introduced into a natural gas liquefier, resulting in liquefaction of the natural gas.

Kountz, Kenneth J. (Palatine, IL); Bishop, Patrick M. (Chicago, IL)

2003-01-01T23:59:59.000Z

227

List of Commercial Refrigeration Equipment Incentives | Open Energy  

Open Energy Info (EERE)

Refrigeration Equipment Incentives Refrigeration Equipment Incentives Jump to: navigation, search The following contains the list of 103 Commercial Refrigeration Equipment Incentives. CSV (rows 1 - 103) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active AEP Appalachian Power - Commercial and Industrial Rebate Programs (West Virginia) Utility Rebate Program West Virginia Commercial Industrial Central Air conditioners Chillers Custom/Others pending approval Heat pumps Lighting Lighting Controls/Sensors Motor VFDs Programmable Thermostats Commercial Refrigeration Equipment Ground Source Heat Pumps Yes AEP Ohio - Commercial New Construction Energy Efficiency Rebate Program (Ohio) Utility Rebate Program Ohio Commercial Industrial Local Government Municipal Utility

228

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

229

ARTI Refrigerant Database  

Science Conference Proceedings (OSTI)

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern.

Calm, J.M. [Calm (James M.), Great Falls, VA (United States)

1994-05-27T23:59:59.000Z

230

Commissioning and Operational Experience with 1 kW Class Helium Refrigerator/Liquefier for SST?1  

Science Conference Proceedings (OSTI)

The helium refrigerator/liquefier (R/L) for the Steady State Super conducting Tokamak (SST?1) has been developed with very stringent specifications for the different operational modes. The total refrigeration capacity is 650 W at 4.5 K and liquefaction capacity of 200 l/h. A cold circulation pump is used for the forced flow cooling of 300 g/s supercritical helium (SHe) for the magnet system (SCMS). The R/L has been designed also to absorb a 200 W transient heat load of the SCMS. The plant consists of a compressor station

C. P. Dhard; B. Sarkar; Ruchi Misra; A. K. Sahu; V. L. Tanna; J. Tank; P. Panchal; J. C. Patel; G. D. Phadke; Y. C. Saxena

2004-01-01T23:59:59.000Z

231

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

232

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

233

Heat Transfer Fluids Containing Nanoparticles  

commercial and industrial heat-transfer applications. ... Refrigeration and other cooling systems Nuclear reactors Aerospace Defense Grinding and ...

234

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

235

Method of removing an immiscible lubricant from a refrigeration system and apparatus for same  

DOE Patents (OSTI)

A method of separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed.

Spauschus, Hans O. (Stockbridge, GA); Starr, Thomas L. (Roswell, GA)

1999-01-01T23:59:59.000Z

236

Method of reducing chlorofluorocarbon refrigerant emissons to the atmosphere  

DOE Patents (OSTI)

A method is disclosed for reducing chloroflurocarbon (CFC) refrigerant emissions during removal or transfer or refrigerants from a vapor compression cooling system or heat pump which comprises contacting the refrigerant with a suitable sorbent material. The sorbent material allows for the storage and retention or the chlorofluorocarbon in non-gaseous form so that it does not tend to escape to the atmosphere where it would cause harm by contributing to ozone depletion. In other aspects of the invention, contacting of CFC refrigerants with sorbent material allows for purification and recycling of used refrigerant, and a device containing stored sorbent material can be employed in the detection of refrigerant leakage in a cooling system or heat pump.

DeVault, Robert C. (Knoxville, TN); Fairchild, Phillip D. (Clinton, TN); Biermann, Wendell J. (Fayetteville, NY)

1990-01-01T23:59:59.000Z

237

Optimal Design Refrigeration System for a Mucilage Glue Fiber Factory  

E-Print Network (OSTI)

In a mucilage glue fiber factory, the design of the refrigeration system takes into account the characteristics of mucilage glue fiber production and fully uses the refrigeration compressor heat to economize energy and reduce the production cost. In this paper, the author introduces different points of this kind of design with conventional design. For efficient use of the compressed heat of the refrigeration system, the designer should calculate the number of condensers according to the changes that the refrigeration system undergoes after using the soft water as cooling water. To economize the investment, the designer should use the refrigeration workshop and the soft water workshop and obtain optimum processing to shorten the duct. Through an economizing energy analysis, the paper demonstrates that an optimum design for a refrigeration system for a mucilage glue factory has a significant energy saving potential.

Tan, C.; Liu, J.; Tang, F.; Liu, Y.

2006-01-01T23:59:59.000Z

238

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

239

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

240

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

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

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

242

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

243

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

244

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

245

BTRIC - Refrigerant testing heats up  

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

cases and three 12 foot freezer cases are in the indoor chamber, and their condenser and compressor rack are in the outdoor one. Plastic tubs filled with water simulate...

246

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

247

Quantum-enhanced absorption refrigerators  

E-Print Network (OSTI)

Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators.

Luis A. Correa; José P. Palao; Daniel Alonso; Gerardo Adesso

2013-08-19T23:59:59.000Z

248

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

249

An Advanced Solar-Powered Rotary Solid Adsorption Refrigerator with High Performance  

E-Print Network (OSTI)

In this paper, according to practical consideration, a new solar powered rotary solid adsorption refrigerator system adopting activated carbon fibre + ethanol as its adsorption pair has been designed with higher performance. Moreover, the principle of the refrigeration cycle, different components of the machine, selection of working pairs and feasible theory analysis of the refrigeration system all have been presented in detail. In addition, it shows that the new refrigerator has many great advantages including a simple structure, fast refrigeration, higher thermodynamic coefficient, friendly to the atmospheric environment, etc. This paper explains that the refrigerating process is constant, which has a promising potential for competing the 'intermittent' cycle reported before. Through improving the refrigerant performance of heat and mass transfer in the adsorbent bed, the refrigeration cycle has been advanced from the aspect of utilization of the thermal energy from low-temperature level resources. In addition, it is shown that the commercial solar powered refrigerator will be existent in the near future.

Zheng, A.; Gu, J.

2006-01-01T23:59:59.000Z

250

Potential Refrigerants for Power Electronics Cooling  

DOE Green Energy (OSTI)

In the past, automotive refrigerants have conventionally been used solely for the purpose of air conditioning. However, with the development of hybrid-electric vehicles and the incorporation of power electronics (PEs) into the automobile, automotive refrigerants are taking on a new role. Unfortunately, PEs have lifetimes and functionalities that are highly dependent on temperature and as a result thermal control plays an important role in the performance of PEs. Typically, PEs are placed in the engine compartment where the internal combustion engine (ICE) already produces substantial heat. Along with the ICE heat, the additional thermal energy produced by PEs themselves forces designers to use different cooling methods to prevent overheating. Generally, heat sinks and separate cooling loops are used to maintain the temperature. Disturbingly, the thermal control system can consume one third of the total volume and may weigh more than the PEs [1]. Hence, other avenues have been sought to cool PEs, including submerging PEs in automobile refrigerants to take advantage of two-phase cooling. The objective of this report is to explore the different automotive refrigerants presently available that could be used for PE cooling. Evaluation of the refrigerants will be done by comparing environmental effects and some thermo-physical properties important to two-phase cooling, specifically measuring the dielectric strengths of potential candidates. Results of this report will be used to assess the different candidates with good potential for future use in PE cooling.

Starke, M.R.

2005-10-24T23:59:59.000Z

251

Heat transfer characteristics of a surface type direct contact boiler  

DOE Green Energy (OSTI)

Two direct contact heat exchangers were constructed and test results were obtained using water and refrigerant 113 as the working fluids. The heat exchangers were operated in a three-phase mode; the water remained liquid throughout the vessel and the liquid refrigerant 113 underwent vaporization following direct injection into the water. The effect of important operational parameters--operating heights, refrigerant 113 injection techniques, mass flow ratios, and temperatures--was studied to determine generalized trends important in the design and operation of a prototype three-phase direct contact heat exchanger. The primary system used in this study performed well overall. The initial favorable results of this study warrant further investigation of direct contact heat exchange as a means of utilizing geothermal energy.

Deeds, R.S.; Jacobs, H.R.; Boehm, R.F.

1976-03-01T23:59:59.000Z

252

Thermosyphon coil arrangement for heat pump outdoor unit  

DOE Patents (OSTI)

For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement there for which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil has a feed portion and an exit portion leading to a separator drum from which liquid refrigerant is returned through downcomer line for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation. 9 figs.

Draper, R.

1984-05-22T23:59:59.000Z

253

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

254

Air Conditioning with Magnetic Refrigeration : An Efficient, Green Compact Cooling System Using Magnetic Refrigeration  

SciTech Connect

BEETIT Project: Astronautics is developing an air conditioning system that relies on magnetic fields. Typical air conditioners use vapor compression to cool air. Vapor compression uses a liquid refrigerant to circulate within the air conditioner, absorb the heat, and pump the heat out into the external environment. Astronautics’ design uses a novel property of certain materials, called “magnetocaloric materials”, to achieve the same result as liquid refrigerants. These magnetocaloric materials essentially heat up when placed within a magnetic field and cool down when removed, effectively pumping heat out from a cooler to warmer environment. In addition, magnetic refrigeration uses no ozone-depleting gases and is safer to use than conventional air conditioners which are prone to leaks.

None

2010-09-01T23:59:59.000Z

255

HVAC Optimized Heat Exchangers Research Project | Department of Energy  

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

Optimized Heat Exchangers Research Optimized Heat Exchangers Research Project HVAC Optimized Heat Exchangers Research Project The U.S. Department of Energy is currently conducting research into heating, ventilation, and air conditioning (HVAC) optimized heat exchangers. The information generated in this study will demonstrate performance improvements that can be achieved through optimization of refrigerant circuitry for non-uniform inlet air distribution. The tubing circuitry on fin-tube heat exchangers used in residential space-conditioning systems is typically designed assuming uniform airflow through the finned passageways. However, the air flow in installed systems is highly non-uniform, resulting in mismatched refrigerant-air heat transfer that reduces the capacity of the heat exchanger and efficiency of

256

ARTI refrigerant database  

Science Conference Proceedings (OSTI)

The Refrigerant Database is an information system on alternative refrigerants, associated lubricants, and their use in air conditioning and refrigeration. It consolidates and facilitates access to property, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alterative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on various refrigerants. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates.

Calm, J.M.

1997-02-01T23:59:59.000Z

257

Regenerator for Magnetic Refrigerants  

Ames Laboratory researchers have developed a new magnetic material that can be used at low temperatures (sub liquid hydrogen) for magnetic refrigerators.

258

China Refrigerator Information Label  

E-Print Network (OSTI)

LBNL-246E China Refrigerator Information Label: Specification Development and Potential Impact Jianhong Cheng China National Institute of Standardization Tomoyuki Sakamoto The Institute of Energy

259

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

260

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

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


261

Available Technologies: Convection Heat Pump  

APPLICATIONS OF TECHNOLOGY: Solar thermal systems; Heating and cooling systems for buildings; Refrigeration; Compressed air source; Recycling waste heat from chimneys

262

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

263

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

264

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

265

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

266

Energy Efficient Operation of Ammonia Refrigeration Systems  

SciTech Connect

Ammonia refrigeration systems typically offer many energy efficiency opportunities because of their size and complexity. This paper develops a model for simulating single-stage ammonia refrigeration systems, describes common energy saving opportunities, and uses the model to quantify those opportunities. The simulation model uses data that are typically available during site visits to ammonia refrigeration plants and can be calibrated to actual consumption and performance data if available. Annual electricity consumption for a base-case ammonia refrigeration system is simulated. The model is then used to quantify energy savings for six specific energy efficiency opportunities; reduce refrigeration load, increase suction pressure, employ dual suction, decrease minimum head pressure set-point, increase evaporative condenser capacity, and reclaim heat. Methods and considerations for achieving each saving opportunity are discussed. The model captures synergistic effects that result when more than one component or parameter is changed. This methodology represents an effective method to model and quantify common energy saving opportunities in ammonia refrigeration systems. The results indicate the range of savings that might be expected from common energy efficiency opportunities.

Mohammed, Abdul Qayyum [University of Dayton, Ohio; Wenning, Thomas J [ORNL; Sever, Franc [University of Dayton, Ohio; Kissock, Professor Kelly [University of Dayton, Ohio

2013-01-01T23:59:59.000Z

267

Energy Saving with Absorption Refrigeration Technologies  

E-Print Network (OSTI)

Absorption refrigeration technology can be an economical and cost effective means of reducing energy cost and/or improving the efficiency and output of your process. We believe the potential benefits of absorption refrigeration technology have generally been overlooked by the process industry. This paper will address the application of the lithium bromide-water cycle in various energy saving modes. A waste heat powered absorption chiller producing chilled water can reduce energy consumption in a process plant by replacing an existing mechanical refrigeration system or replacing cooling tower water with a lower temperature cooling medium at negligible increase in energy cost. A variety of waste heat sources can be used at temperatures as low as 150 F.

Davis, R. C.

1984-01-01T23:59:59.000Z

268

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

269

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

270

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

271

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

272

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

273

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

274

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

275

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

276

Solar refrigeration in rural West Bengal: Design of a product service system.  

E-Print Network (OSTI)

??Solarbear is a refrigerator that cools with the heat of the sun only. This technology, more formally known as solar powered adsorption cooling, has been… (more)

Van Genuchten, R.P.

2011-01-01T23:59:59.000Z

277

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

278

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

279

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

280

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

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

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

282

ARTI Refrigerant Database  

Science Conference Proceedings (OSTI)

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on R-32, R-123, R-124, R- 125, R-134a, R-141b, R142b, R-143a, R-152a, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses polyalkylene glycol (PAG), ester, and other lubricants. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits.

Calm, J.M.

1992-04-30T23:59:59.000Z

283

Available Technologies: Heat Transfer Interface for Thermo ...  

Refrigeration systems; Internal combustion engines; ... The components of the technology could be used to improve heat transfer in industrial, ...

284

Carbon Dioxide and Ionic Liquid Refrigerants: Compact, Efficient Air Conditioning with Ionic Liquid-Based Refrigerants  

SciTech Connect

BEETIT Project: Notre Dame is developing an air-conditioning system with a new ionic liquid and CO2 as the working fluid. Synthetic refrigerants used in air conditioning and refrigeration systems are potent GHGs and can trap 1,000 times more heat in the atmosphere than CO2 alone—making CO2 an attractive alternative for synthetic refrigerants in cooling systems. However, operating cooling systems with pure CO2 requires prohibitively high pressures and expensive hardware. Notre Dame is creating a new fluid made of CO2 and ionic liquid that enables the use of CO2 at low pressures and requires minimal changes to existing hardware and production lines. This new fluid also produces no harmful emissions and can improve the efficiency of air conditioning systems— enabling new use of CO2 as a refrigerant in cooling systems.

2010-10-01T23:59:59.000Z

285

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

286

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

287

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

288

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

289

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

290

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

291

Heat Pump Systems  

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

Like a refrigerator, heat pumps use electricity to move heat from a cool space into a warm space, making the cool space cooler and the warm space warmer. Because they move heat rather than generate...

292

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

293

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

294

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

295

Refrigerated cryogenic envelope  

DOE Patents (OSTI)

An elongated cryogenic envelope including an outer tube and an inner tube coaxially spaced within said inner tube so that the space therebetween forms a vacuum chamber for holding a vacuum. The inner and outer tubes are provided with means for expanding or contracting during thermal changes. A shield is located in the vacuum chamber intermediate the inner and outer tubes; and, a refrigeration tube for directing refrigeration to the shield is coiled about at least a portion of the inner tube within the vacuum chamber to permit the refrigeration tube to expand or contract along its length during thermal changes within said vacuum chamber.

Loudon, John D. (Boulder, CO)

1976-11-16T23:59:59.000Z

296

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

297

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

298

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

299

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

300

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

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

Exploring the Limits of Boiling and Evaporative Heat Transfer Using Micro/Nano Structures  

E-Print Network (OSTI)

small passages of compact heat-exchangers, Int J Therm Sci,and refrigeration and compact heat exchangers [4], chemical

Lu, Ming-Chang

2010-01-01T23:59:59.000Z

302

Heat exchanger-accumulator  

DOE Patents (OSTI)

What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

Ecker, Amir L. (Dallas, TX)

1980-01-01T23:59:59.000Z

303

An Experimental Investigaton of the Effect of Oil on Convective Heat Trasfer and Pressure Drop of a HFC-32/HRC-125 Mixture  

E-Print Network (OSTI)

The heat transfer coefficients and pressure drops of HCFC-22 and a 50% mass mixture of HFC-32/HFC-125 were experimentally measured under flow boiling conditions in a smooth tube. The refrigerants were flowed through an 8 mm diameter smooth tube at mass fluxes of 277, 434, 520 and 700 kg/sm^2. Heat fluxes were applied at values of 5100, 7100 and 11000 W/m^2. The heat transfer coefficients and pressure drops were measured at refrigerant qualities of 10, 15, 20, 25, 30, 40 and 60 percent. The refrigerants were examined at temperatures near 4°C. Oil was added to the HFC-32/HFC-125 mixture in concentrations of 2.6% and 5.4%. Experiments were repeated with the oil laden refrigerant. The heat transfer coefficients for HCFC-22 increased with quality, mass flux and heat flux. The heat transfer coefficients for HFC-32/HFC-125 often decreased at low qualities and increased with quality at high qualities. The pressure drop increased with quality and mass flux for both refrigerants. The heat transfer had a minimal effect upon pressure drop. HFC-32/HFC-125 had a lower pressure drop than HCFC-22 for all conditions. The addition of oil increased the pressure drop. A pressure drop correlation and heat transfer correlation were developed for HFC-32/HFC-125.

McJimsey, Bert Ashford

1994-12-01T23:59:59.000Z

304

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

305

Radial wave thermoacoustic engines: Theory and examples for refrigerators and high?gain narrow?bandwidth photoacoustic spectrometers  

Science Conference Proceedings (OSTI)

A theoretical analysis of radial wave thermoacoustic engines in cylindrical resonators is developed. Impedance and pressure translation equations are presented for open sections of the resonator and for heat exchangers. Coupled first?order differential equations are given for pressure and impedance in the temperature gradient supporting engine section (stack). These quantities are used to calculate heat and work flows and to predict engine performance. Theory and design of a variable quality factor resonator for enhanced photoacoustic spectroscopy are presented. The short stack approximation is developed for the radial geometry and is used along with plane?wave equations to compare refrigerator performance for these two geometries. Results of the comparison are that engines in the plane?wave geometry are better overall refrigerators when maximizing the coefficient of performance and cooling capacity together.

W. Patrick Arnott; Richard Raspet; Hans Moosmüller

1996-01-01T23:59:59.000Z

306

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

307

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

308

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

309

Oil cooled, hermetic refrigerant compressor  

DOE Patents (OSTI)

A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler and is then delivered through the shell to the top of the motor rotor where most of it is flung radially outwardly within the confined space provided by the cap which channels the flow of most of the oil around the top of the stator and then out to a multiplicity of holes to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator from which the suction gas passes by a confined path in pipe to the suction plenum and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum. 3 figs.

English, W.A.; Young, R.R.

1985-05-14T23:59:59.000Z

310

Oil cooled, hermetic refrigerant compressor  

DOE Patents (OSTI)

A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum 64.

English, William A. (Murrysville, PA); Young, Robert R. (Murrysville, PA)

1985-01-01T23:59:59.000Z

311

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

312

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

313

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

314

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

315

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

316

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

317

DEVELOPMENT OF SOLAR DRIVEN ABSORPTION AIR CONDITIONERS AND HEAT PUMPS  

E-Print Network (OSTI)

the Annual DOE Active Solar Heating and Cooling Contractors'and Annual DOE Active Solar Heating and Cooling Contractors'refrigeration systems for solar active heating and cooling

Dao, K.

2013-01-01T23:59:59.000Z

318

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

319

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

320

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

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


321

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

322

Optimizing the Low Temperature Cooling Energy Supply: Experimental Performance of an Absorption Chiller, a Compression Refrigeration Machine and Direct Cooling - a Comparison  

E-Print Network (OSTI)

A strategy to optimize the low temperature cooling energy supply of a newly build office building is discussed against the background of a changing energy system. It is focused on, what production way - Direct Cooling, the Compression Refrigeration Machine or the Absorption Chiller provided with heat from Combined Heat and Power Plants - has the lowest primary energy consumption at what load level. For low levels this is direct cooling. If demand exceeds the capacity of direct cooling, the absorption chiller is the option to choose. However, in future the compression refrigeration machine is more efficient at providing high load levels than the Absorption Chiller. The operation analysis shows that flow rates are often held constant and the re-cooling temperatures are often above the ambient temperature. By the integration of automatic flow rate control and lowering the re-cooling temperature of the chillers, electricity consumption of pumps can be reduced and energy efficiency enhanced.

Uhrhan, S.; Gerber, A.

2012-01-01T23:59:59.000Z

323

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

324

Super energy saver heat pump with dynamic hybrid phase change material  

Science Conference Proceedings (OSTI)

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

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

2010-07-20T23:59:59.000Z

325

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

326

Application of Cryocoolers to a Vintage Dilution Refrigerator  

SciTech Connect

A dilution refrigerator is required for 50mK detector operation of CDMS (Cryogenic Dark Matter Search). Besides shielding the dilution refrigerator itself, the liquid nitrogen shield and liquid helium bath in the refrigerator cool the detector cryostat heat shields and cool electronics, resulting in significant external heat loads at 80K and at 4K. An Oxford Instruments Kelvinox 400 has served this role for ten years but required daily transfers of liquid nitrogen and liquid helium. Complicating the cryogen supply is the location 800 meters below ground in an RF shielded, class 10000 clean room at Soudan, MN. Nitrogen and helium re-liquefiers using cryocoolers were installed outside the clean room and continuously condense room temperature gas and return the liquids to the dilution refrigerator through a transfer line. This paper will describe the design, installation, controls and performance of liquefaction systems.

Schmitt, Richard; Smith, Gary; Ruschman, Mark; /Fermilab; Beaty, Jim; /Minnesota U.

2011-06-06T23:59:59.000Z

327

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

328

Non-intrusive refrigerant charge indicator - Energy ...  

... -phase refrigerant line section. The measured temperature can be used to determine the refrigerant charge status of an HVAC system, ...

329

Demand Response Opportunities in Industrial Refrigerated Warehouses...  

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

Demand Response Opportunities in Industrial Refrigerated Warehouses in California Title Demand Response Opportunities in Industrial Refrigerated Warehouses in California...

330

ARTI Refrigerant Database  

SciTech Connect

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R-717 (ammonia), ethers, and others as well as azeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents to accelerate availability of the information and will be completed or replaced in future updates.

Cain, J.M. (Calm (James M.), Great Falls, VA (United States))

1993-04-30T23:59:59.000Z

331

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

332

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

333

Proceedings: Commercial Refrigeration Research Workshop  

Science Conference Proceedings (OSTI)

Improving refrigeration systems for commercial use can enhance both utility load factors and supermarket profits. This workshop has pinpointed research needs in commercial refrigeration and systems integration for a supermarket environment.

1984-10-01T23:59:59.000Z

334

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

335

COLD STORAGE DESIGN REFRIGERATION EQUIPMENT  

E-Print Network (OSTI)

COLD STORAGE DESIGN AND REFRIGERATION EQUIPMENT REFRIGERATION OF FISH - PART 1 \\ "..\\- ,,, T I Fishery Leaflet 427 Washington 25, D. C. June 1956 REFRIGERATION OF FISH - PART em; COlD STORAGE DESIGN · · · · · 18 Specific design features 0 0 · · · · · · · · · · · · · · 19 Refrigerated surfaces 0 · · 0 0 0 · 0

336

Japanese refrigerators field testing  

SciTech Connect

Residential refrigerators consume the equivalent of 1700 megawatts (MW) of baseload power in the Bonneville Power Administration (BPA) service area. Japanese manufacturers have designed refrigerator units that appear more energy efficient than some currently available American models. This report summarizes preliminary findings from field testing of 12 refrigerators of Japanese manufacture to evaluate annual kilowatt hour (kWh) use during actual operation. The units have also undergone laboratory testing sponsored by BPA at ETL Testing Laboratories, Inc. in Cortland, New York. A final report of the project -- due at the end of 1989 -- will correlate in detail the results of field and laboratory tests in comparison to performance ratings determined by the manufacturer.

Lou, A.T.

1989-03-01T23:59:59.000Z

337

Japanese Refrigerators Field Testing.  

SciTech Connect

Residential refrigerators consume the equivalent of 1700 megawatts (MW) of baseload power in the Bonneville Power Administration (BPA) service area. Japanese manufacturers have designed refrigerator units that appear more energy efficient than some currently available American models. This report summarizes preliminary findings from field testing of 12 refrigerators of Japanese manufacture to evaluate annual kilowatt hour (kWh) use during actual operation. The units have also undergone laboratory testing sponsored by BPA at ETL Testing Laboratories, Inc. in Cortland, New York. A final report of the project -- due at the end of 1989 -- will correlate in detail the results of field and laboratory tests in comparison to performance ratings determined by the manufacturer.

Lou, Albert T.

1989-03-01T23:59:59.000Z

338

ARTI Refrigerant Database  

Science Conference Proceedings (OSTI)

The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R-134a, R-141b, R-142b, R-143a, R-152a, R-245ca, R-290 (propane), R- 717 (ammonia), ethers, and others as well as azeotropic and zeotropic and zeotropic blends of these fluids. It addresses lubricants including alkylbenzene, polyalkylene glycol, ester, and other synthetics as well as mineral oils. It also references documents on compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. A computerized version is available that includes retrieval software.

Calm, J.M.

1992-11-09T23:59:59.000Z

339

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

340

Refrigerator recycling and CFCs  

SciTech Connect

Utility-sponsored refrigerator and freezer pick-up programs have removed almost 900,000 inefficient appliances from the North American electric grid to date. While the CFC-12 refrigerant from the discarded appliances is typically removed and recycled, in all but a few programs the CFC-11 in the foam insulation is not. About a quarter-billion pounds of CFC-11 are banked in refrigerator foam in the United States. Release of this ``bank`` of CFC, combined with that from foam insulation used in buildings, will be the largest source of future emissions if preventive measures are not taken. Methods exist to recover the CFC for reuse or to destroy it by incineration. The task of recycling or destroying the CFCs and other materials from millions of refrigerators is a daunting challenge, but one in which utilities can play a leadership role. E Source believes that utilities can profitably serve as the catalyst for public-private partnerships that deliver comprehensive refrigerator recycling. Rather than treating such efforts solely as a DSM resource acquisition, utilities could position these programs as a multifaceted service delivery that offers convenient appliance removal for homeowners, a solid waste minimization service for landfills, a source of recycled materials for industry, and a CFC recovery and/or disposal service in support of the HVAC industry and society`s atmospheric protection goals and laws. Financial mechanisms could be developed through these public-private enterprises to ensure that utilities are compensated for the extra cost of fully recycling refrigerators, including the foam CFC.

Shepard, M.; Hawthorne, W.; Wilson, A.

1994-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "refrigerant flow heat" 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.
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341

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

342

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

343

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process  

DOE Patents (OSTI)

Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.

Gschneidner, Jr., Karl A. (Ames, IA); Pecharsky, Vitalij K. (Ames, IA)

1998-04-28T23:59:59.000Z

344

Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process  

DOE Patents (OSTI)

Active magnetic regenerator and method using Gd{sub 5} (Si{sub x}Ge{sub 1{minus}x}){sub 4}, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd{sub 5} (Si{sub x} Ge{sub 1{minus}x}){sub 4}, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing. 27 figs.

Gschneidner, K.A. Jr.; Pecharsky, V.K.

1998-04-28T23:59:59.000Z

345

The Quantum Absorption Refrigerator Amikam Levy and Ronnie Kosloff  

E-Print Network (OSTI)

source to replace mechanical work for driving a heat pump [1]. The first device was developed in 1850 an ab- sorption refrigerator with no moving parts [2]. This idea has been incorporated recently c J h P Tc Th Tw - - - 0 FIG. 1: The quantum trickle: A quantum heat pump des- ignated

Kosloff, Ronnie

346

Improving the energy efficiency of refrigerators in India  

Science Conference Proceedings (OSTI)

Five state-of-the-art, production refrigerators from different manufacturers in India were subjected to a variety of appliance rating and performance evaluation test procedures in an engineering laboratory. Cabinet heat loss, compressor calorimeter, high-ambient pull-down, and closed-door energy consumption tests were performed on each unit to assess the current status of commercially available Indian refrigerators and refrigerator component efficiencies. Daily energy consumption tests were performed at nominal line voltages and at 85% and 115% of nominal voltage to assess the effect of grid voltage variations. These test results were also used to indicate opportunities for effective improvements in energy efficiency. A widely distributed ``generic`` computer model capable of simulating single-door refrigerators with a small interior freezer section was used to estimate cabinet heat loss rates and closed door energy consumption values from basic cabinet and refrigeration circuit inputs. This work helped verify the model`s accuracy and potential value as a tool for evaluating the energy impact of proposed design options. Significant differences ranging from 30 to 90% were seen in the measured performance criterion for these ``comparable`` refrigerators suggesting opportunities for improvements in individual product designs. Modeled cabinet heat loadings differed from experimentally extrapolated values in a range from 2--29%, and daily energy consumption values estimated by the model differed from laboratory data by as little as 3% or as much as 25%, which indicates that refinement of the model may be needed for this single-door refrigerator type. Additional comparisons of experimentally measured performance criteria such as % compressor run times and compressor cycling rates to modeled results are given. The computer model is used to evaluate the energy saving impact of several modest changes to the basic Indian refrigerator design.

Sand, J.R.; Vineyard, E.A. [Oak Ridge National Lab., TN (United States); Bohman, R.H. [Consulting Engineer, Cedar Rapids, IA (United States)

1995-04-01T23:59:59.000Z

347

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

348

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

349

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

350

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

351

Method of removing an immiscible lubricant from a refrigeration system and apparatus for same  

DOE Patents (OSTI)

A method is described for separating an immiscible lubricant from a liquid refrigerant in a refrigerating system including a compressor, a condenser, an expansion device and an evaporator, wherein the expansion device is connected to the condenser by a liquid refrigerant flow line for liquid refrigerant and immiscible lubricant. The method comprising slowing the rate of flow of the liquid refrigerant and immiscible lubricant between the condenser and the expansion device such that the liquid refrigerant and the immiscible lubricant separate based upon differences in density. The method also comprises collecting the separated immiscible lubricant in a collection chamber in fluid communication with the separated immiscible lubricant. Apparatus for performing the method is also disclosed. 3 figs.

Spauschus, H.O.; Starr, T.L.

1999-03-30T23:59:59.000Z

352

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

353

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

354

Development of Refrigerant Change Indicator and Dirty Air Filter Sensor  

Science Conference Proceedings (OSTI)

The most common problems affecting residential and light commercial heating, ventilation, and air-conditioning (HVAC) systems are slow refrigerant leaks and dirty air filters. Equipment users are usually not aware of a problem until most of the refrigerant has escaped or the air filter is clogged with dirt. While a dirty air filter can be detected with a technology based on the air pressure differential across the filter, such as a ''whistling'' indicator, it is not easy to incorporate this technology into existing HVAC diagnostic equipment. Oak Ridge National Laboratory is developing a low-cost, nonintrusive refrigerant charge indicator and dirty air filter detection sensor. The sensors, based on temperature measurements, will be inexpensive and easy to incorporate into existing heat pumps and air conditioners. The refrigerant charge indicator is based on the fact that when refrigerant starts to leak, the evaporator coil temperature starts to drop and the level of liquid subcooling drops. When the coil temperature or liquid subcooling drops below a preset reading, a signal, such as a yellow warning light, can be activated to warn the equipment user that the system is undercharged. A further drop of coil temperature or liquid subcooling below another preset reading would trigger a second warning signal, such as a red warning light, to warn the equipment user that the unit now detects a leak and immediate action should be taken. The warning light cannot be turned off until it is re-set by a refrigeration repairman. To detect clogged air filters, two additional temperature sensors can be applied, one each across the evaporator. When the air filter is accumulating buildup, the temperature differential across the evaporator will increase because of the reduced airflow. When the temperature differential reaches a pre-set reading, a signal will be sent to the equipment user that the air filter needs to be changed. A traditional refrigerant charge indicator requires intrusion into the system to measure the refrigerant high-side and low-side pressures. Once the pressures are known, based on the equipment's refrigerant charging chart? or in most cases, based on the technician's experience? the refrigerant charging status is determined. However, there is a catch: by the time a refrigeration technician is called, most of the refrigerant has already escaped into the atmosphere. The new technology provides a real-time warning so that when, say, 20% of the refrigerant has leaked, the equipment users will be warned, even though the equipment is still functioning properly at rated capacity. Temperature sensors are becoming very accurate and very low in cost, compared with pressure sensors. Using temperature sensors to detect refrigerant charge status is inherently nonintrusive, inexpensive, and accurate. With the addition of two temperature sensors for detecting dirty air filters, the capability of the diagnostic equipment is further enhanced with very little added cost. This report provides laboratory test data on the change of indoor coil refrigerant temperature and subcooling as a function of refrigerant charge for a 2-ton split heat pump system. The data can be used in designing the indicators for refrigerant loss and dirty air filter sensors.

Mei, V.

2003-06-24T23:59:59.000Z

355

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

356

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

357

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

358

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

359

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

360

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

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

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

362

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

363

Computer program for determining the thermodynamic properties of Freon refrigerants  

DOE Green Energy (OSTI)

This program was written to be used as a subroutine. The program determines the thermodynamics of Freon refrigerants. The following refrigerants can be analyzed F-11, F-12, F-13, F-14, F-21, F-22, F-23, F-113, and F-114. The subroutine can evaluate a thermodynamic state for these refrigerants given any of the following pairs of state quantities: pressure and quality, pressure and entropy, pressure and enthalpy, temperature and quality, temperature and specific volume, and temperature and pressure. These six pairs of knowns allow the user to analyze any thermodynamic cycle utilizing a refrigerant as the working fluid. The Downing form of the Martin equation of state was used. This report contains a brief description, flow chart and listing of all subroutines required.

Riemer, D.H.; Jacobs, H.R.; Boehm, R.F.

1977-12-01T23:59:59.000Z

364

Computer program for determining the thermodynamic properties of freon refrigerants  

DOE Green Energy (OSTI)

This program was written to be used as a subroutine. The program determines the thermodynamics of Freon refrigerants. The following refrigerants can be analyzed F-11, F-12, F-13, F-14, F-21, F-22, F-23, F-113, and F-114. The subroutine can evaluate a thermodynamic state for these refrigerants given any of the following pairs of state quantities: pressure and quality, pressure and entropy, pressure and enthalpy, temperature and quality, temperature and specific volume and temperature and pressure. These six pairs of knowns allow the user to analyze any thermodynamic cycle utilizing a refrigerant as the working fluid. The Downing form of the Martin equation of state was used. A brief description, flow chart, and listing of all subroutines required are presented.

Riemer, D.H.; Jacobs, H.R.; Boehm, R.F.

1976-07-01T23:59:59.000Z

365

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

366

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

367

Condensation of refrigerants on vertical fluted tubes  

DOE Green Energy (OSTI)

Experiments were run to determine heat transfer performance of single vertical fluted tubes with selected fluids condensing on the outside. Working fluids included six fluorocarbons (Refrigerants 11, 21, 22, 113, 114, and 115) and a hydrocarbon (Refrigerant 600a or isobutane). The nine test tubes were of 2.54-cm (1-in.) nominal outside diameter and 1.2 m (4 ft) in length with from 0 (smooth) to 60 axial flutes. Condensing heat transfer coefficients ranged from 620 to 7900 W/m/sup 2/ . K (110 to 1400 Btu/hr . ft/sup 2/ . /sup 0/F) over the heat flux range of 2000 to 43,000 W/m/sup 2/ (920 to 13,600 Btu/hr . ft/sup 2/). All parameters are based on total condensing surface area. The data show that, for a given heat flux, a fluted tube can increase condensing coefficients up to 6.0 times smooth tube values. Further heat transfer enhancement was achieved by the use of drainage skirts on fluted tubes; these skirts effectively divided the 1.2-m (4-ft) tubes into two, four, and eight equal condensing lengths.

Combs, S.K.; Mailen, G.S.; Murphy, R.W.

1978-08-01T23:59:59.000Z

368

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

369

SCREW COMPRESSOR CHARACTERISTICS FOR HELIUM REFRIGERATION SYSTEMS  

SciTech Connect

The oil injected screw compressors have practically replaced all other types of compressors in modern helium refrigeration systems due to their large displacement capacity, minimal vibration, reliability and capability of handling helium's high heat of compression.At the present state of compressor system designs for helium systems, typically two-thirds of the lost input power is due to the compression system. Therefore it is important to understand the isothermal and volumetric efficiencies of these machines to help properly design these compression systems to match the refrigeration process. This presentation summarizes separate tests that have been conducted on Sullair compressors at the Superconducting Super-Collider Laboratory (SSCL) in 1993, Howden compressors at Jefferson Lab (JLab) in 2006 and Howden compressors at the Spallation Neutron Source (SNS) in 2006. This work is part of an ongoing study at JLab to understand the theoretical basis for these efficiencies and their loss

Ganni, Venkatarao; Knudsen, Peter; Creel, Jonathan; Arenius, Dana; Casagrande, Fabio; Howell, Matt

2008-03-01T23:59:59.000Z

370

Multilayer Thermionic Refrigeration  

DOE Green Energy (OSTI)

A review is presented of our program to construct an efficient solid state refrigerator based on thermionic emission of electrons over periodic barriers in the solid. The experimental program is to construct a simple device with one barrier layer using a three layers: metal-semiconductor-metal. The theoretical program is doing calculations to determine: (i) the optimal layer thickness, and (ii) the thermal conductivity.

Mahan, G.D.

1999-08-30T23:59:59.000Z

371

Dilution Refrigeration of Multi-Ton Cold Masses  

E-Print Network (OSTI)

Dilution refrigeration is the only means to provide continuous cooling at temperatures below 250 mK. Future experiments featuring multi-ton cold masses require a new generation of dilution refrigeration systems, capable of providing a heat sink below 10 mK at cooling powers which exceed the performance of present systems considerably. This thesis presents some advances towards dilution refrigeration of multi-ton masses in this temperature range. A new method using numerical simulation to predict the cooling power of a dilution refrigerator of a given design has been developed in the framework of this thesis project. This method does not only allow to take into account the differences between an actual and an ideal continuous heat exchanger, but also to quantify the impact of an additional heat load on an intermediate section of the dilute stream. In addition, transient behavior can be simulated. The numerical model has been experimentally verified with a dilution refrigeration system which has been designed, ...

Wikus, P; CERN. Geneva

2007-01-01T23:59:59.000Z

372

Vaccine refrigerator testing. Final report  

SciTech Connect

For the Central American Health Clinic Project initiated in 1986, Sandia National Laboratories and the Florida Solar Energy Center recognized the need for a test and evaluation program for vaccine refrigeration systems. At the Florida Solar Energy Center, side-by-side testing of three photovoltaic powered vaccine refrigerators began in 1987. The testing was expanded in 1988 to include a kerosene absorption refrigerator. This report presents observations, conclusions, and recommendations derived from testing the four vaccine refrigeration systems. Information is presented pertaining to the refrigerators, photovoltaic arrays, battery subsystems, charge controllers, and user requirements. This report should be of interest to designers, manufacturers, installers, and users of photovoltaic-powered vaccine refrigeration systems and components.

Ventre, G.G. [Univ. of Central Florida, Orlando, FL (United States); Kilfoyle, D.; Marion, B. [Florida Solar Energy Center, Cape Canaveral, FL (United States)

1990-06-01T23:59:59.000Z

373

Magnetic Refrigeration - Programmaster.org  

Science Conference Proceedings (OSTI)

Aug 6, 2013 ... Magnetic Refrigeration a 21st Century Highly Efficient and Green Cooling .... In order to advance their incorporation in prototypes and industrial ...

374

PERFORMANCE OF A STIRLING ENGINE POWERED HEAT ACTIVATED HEAT PUMP  

E-Print Network (OSTI)

by the heat pump effect. The Stirling engine/Rankine cycle refrigeration loop heat pump being developed would and replacement segments of each. The Preliminary Design was completed in 1975. During this phase, several. As a result of this phase, a Stirling/ Rankine, prime mover/refrigeration cycle approach was selected

Oak Ridge National Laboratory

375

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

376

Heat reclaiming method and apparatus  

DOE Patents (OSTI)

Method and apparatus to extract heat by transferring heat from hot compressed refrigerant to a coolant, such as water, without exceeding preselected temperatures in the coolant and avoiding boiling in a water system by removing the coolant from direct or indirect contact with the hot refrigerant.

Jardine, Douglas M. (Colorado Springs, CO)

1984-01-01T23:59:59.000Z

377

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

378

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

379

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

380

DEVELOPMENT OF AN ADVANCED HEAT EXCHANGER MODEL FOR STEADY STATE AND FROSTING CONDITIONS.  

E-Print Network (OSTI)

??Air-to-refrigerant fin-and-tube heat exchangers are a key component in the heating, air conditioning and refrigeration industry. Considering their dominance, the industry has focused immensely on… (more)

Singh, Varun

2009-01-01T23:59:59.000Z

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

Commercial Refrigeration Equipment | Open Energy Information  

Open Energy Info (EERE)

Refrigeration Equipment Jump to: navigation, search TODO: Add description List of Commercial Refrigeration Equipment Incentives Retrieved from "http:en.openei.orgw...

382

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

383

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

384

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

385

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

386

Modeling the effects of Refrigerant Charging on Air Conditioner Performance Characteristics For Three Expansion Devices  

E-Print Network (OSTI)

An experimental and analytical study concerned with the off-design refrigerant charging of air conditioners is presented. A series of experiments were conducted to characterize the effects of refrigerant charge and type of expansion device on the system performance (capacity, EER, SEER, etc.) of an air conditioner. All experiments were performed according to the ASHRAE Standard [1983]. The effects of off-design refrigerant charge in the system, type of expansion device (capillary tube, TXV, and short-tube orifice), and outdoor dry-bulb temperature (82° to l00°F) on the wet and dry steady state and cyclic tests are addressed in this study. The fully charged condition was established as a base case for all the expansion device systems. A full charge was obtained by charging the unit to the superheat or subcooled condition specified by the manufacturer charging chan. Once the full charge was determined, refrigerant was then added in 5% increments from -20% of full charge to +20% of full charge to cover the full range of charging conditions for a particular expansion device being tested. The investigation of off-design charging indicated that the system performance variables (total capacity, EER, and SEER) of the unit with capillary tube were more sensitive to off-design charging than the systems with TXV and short-tube orifice. From -20% to +20% charging, the capacity and EER showed a strong dependence on the outdoor temperature, but varied little with charge for the TXV and short-tube orifice expansion systems. A -20% charging resulted in a 21% reduction in SEER while a +20% charging produced an 11% reduction in SEER for the unit with capillary tube. For the TXV, SEER dropped 2% and 8% for -20% and +20% refrigerant charging, respectively. The SEER was constant at 9.4 for all the charging condition except for -5% charging where it peaked to 9.9 for the short-tube orifice expansion system. This trend would suggest that the range of sensitivity of a short-tube orifice system is confined within a small refrigerant charge. A new heat exchanger model based on tube-by-tube simulation was developed and integrated into the ORNL heat pump model. The model was capable of simulating the steady state response of a vapor compression air-to-air heat pump and air conditioner commonly used in residential applications. The simulated results were compared with laboratory tests at two outdoor temperatures. It was found that the ORNL model estimates were within an average of 3% of the experimental results from - 10% to +10% charging conditions. The model predicted the system performance up to 8% higher than measured results at +/-20% and +/-15% charging conditions. Among the eight void fraction models studied, the Hughmark model showed the best agreement between superheat and subcooled temperatures, refrigerant flow rate and capacity and the measured results.

Farzad, Mohsen

1990-08-01T23:59:59.000Z

387

Water-heating dehumidifier - Energy Innovation Portal  

A water-heating dehumidifier includes a refrigerant loop including a compressor, at least one condenser, an expansion device and an evaporator including an evaporator ...

388

Helium dilution refrigeration system  

DOE Patents (OSTI)

A helium dilution refrigeration system operable over a limited time period, and recyclable for a next period of operation is disclosed. The refrigeration system is compact with a self-contained pumping system and heaters for operation of the system. A mixing chamber contains [sup 3]He and [sup 4]He liquids which are precooled by a coupled container containing [sup 3]He liquid, enabling the phase separation of a [sup 3]He rich liquid phase from a dilute [sup 3]He-[sup 4]He liquid phase which leads to the final stage of a dilution cooling process for obtaining low temperatures. The mixing chamber and a still are coupled by a fluid line and are maintained at substantially the same level with the still cross sectional area being smaller than that of the mixing chamber. This configuration provides maximum cooling power and efficiency by the cooling period ending when the [sup 3]He liquid is depleted from the mixing chamber with the mixing chamber nearly empty of liquid helium, thus avoiding unnecessary and inefficient cooling of a large amount of the dilute [sup 3]He-[sup 4]He liquid phase. 2 figs.

Roach, P.R.; Gray, K.E.

1988-09-13T23:59:59.000Z

389

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

390

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

391

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

392

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

393

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

394

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

395

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

396

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

397

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

398

Cryogenic refrigeration apparatus  

DOE Patents (OSTI)

A technique for producing a cold environment in a refrigerant system in which input fluid from a compressor at a first temperature is introduced into an input channel of the system and is pre-cooled to a second temperature for supply to one of at least two stages of the system, and to a third temperature for supply to another stage thereof. The temperatures at such stages are reduced to fourth and fifth temperatures below the second and third temperatures, respectively. Fluid at the fourth temperature from the one stage is returned through the input channel to the compressor and fluid at the fifth temperature from the other stage is returned to the compressor through an output channel so that pre-cooling of the input fluid to the one stage occurs by regenerative cooling and counterflow cooling and pre-cooling of the input fluid to the other stage occurs primarily by counterflow cooling.

Crunkleton, James A. (Cambridge, MA)

1992-01-01T23:59:59.000Z

399

Cryogenic refrigeration apparatus  

DOE Patents (OSTI)

A technique for producing a cold environment in a refrigerant system in which input fluid from a compressor at a first temperature is introduced into an input channel of the system and is pre-cooled to a second temperature for supply to one of at least two stages of the system, and to a third temperature for supply to another stage thereof. The temperatures at such stages are reduced to fourth and fifth temperatures below the second and third temperatures, respectively. Fluid at the fourth temperature from the one stage is returned through the input channel to the compressor and fluid at the fifth temperature from the other stage is returned to the compressor through an output channel so that pre-cooling of the input fluid to the one stage occurs by regenerative cooling and counterflow cooling and pre-cooling of the input fluid to the other stage occurs primarily by counterflow cooling. 6 figs.

Crunkleton, J.A.

1992-03-31T23:59:59.000Z

400

The Quantum Absorption Refrigerator  

E-Print Network (OSTI)

A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power J_c vanishes as J_c proportional to T_c^{alpha}, when T_c approach 0, where alpha =d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath.

Amikam Levy; Ronnie Kosloff

2011-09-04T23:59:59.000Z

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

Refrigerant testing heats up | ornl.gov  

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

cases and three 12-foot freezer cases are in the indoor chamber; and their condenser and compressor rack are in the outdoor one. Plastic tubs filled with water simulate...

402

Teton Coin Op Laundry: heat recovery unit. Final report  

SciTech Connect

Experience with a heat recovery unit using Freon 11 refrigerant as a transfer medium is reported. Heat exchangers were fabricated for use in dryer stacks and the waste heat was used in heating the water for the laundry. (MHR)

1984-01-16T23:59:59.000Z

403

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-12-25T23:59:59.000Z

404

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

405

Intrinsically irreversible heat engine  

DOE Patents (OSTI)

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

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

1984-01-01T23:59:59.000Z

406

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

407

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

408

NBSIFI 86-3373 Impact of Refrigerant Property  

E-Print Network (OSTI)

flow and pressure difference is the driving force for fluid flow. The rate of heat transfer is understood to mean the transfer of thermal energy, not the flow of a fluid-like substance called heat in practice. 1 CHAPTER 1 CONTENTS 1­1 Thermodynamics and Heat Transfer 2 1­2 Engineering Heat Transfer 4 1

Oak Ridge National Laboratory

409

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

410

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

411

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)

412

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

413

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

414

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

415

Occupant Response to Window Control Signaling Systems  

E-Print Network (OSTI)

At Savery hall, variable refrigerant flow  (VRF) heat pumps with distributed variable refrigerant flow (VRF) units for

Ackerly, Katherine

2012-01-01T23:59:59.000Z

416

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

417

ETME 422 -REFRIGERATION & HVAC SYSTEMS FALL 2011 LEC -10:00 -10:50am M W F RH 312  

E-Print Network (OSTI)

10/31/2011 ETME 422 - REFRIGERATION & HVAC SYSTEMS FALL 2011 LEC - 10:00 - 10:50am M W F RH 312 Catalog Description ETME 422 PRINCIPLES OF HVAC I F 3 cr. LEC 3 PREREQUISITE: EMEC 320 or EGEN 324. -- Refrigeration and heating, ventilating and air-conditioning (HVAC) for comfort and industrial applications

Dyer, Bill

418

Vapor Compression Refrigeration Technology  

Science Conference Proceedings (OSTI)

... ice from central ice-making facilities to household iceboxes. ... that extracts heat from the space to be cooled. ... for another run of the cooling cycle while ...

2011-10-19T23:59:59.000Z

419

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

E-Print Network (OSTI)

solar heat; • refrigeration loads that can be met either by standard equipment or absorption equivalents; • hot-water and space-heating

Stadler, Michael

2010-01-01T23:59:59.000Z

420

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

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


421

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

422

PARAMETER ESTIMATION BASED MODELS OF WATER SOURCE HEAT PUMPS  

E-Print Network (OSTI)

, Singapore. ©2006, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. (www operating refrigerant pressure limits). A design goal must therefore be to control the rise or drop exponent is dependent on the refrigerant type; the values of the isentropic exponents are obtained from

423

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

424

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

425

Design and installation considerations for refrigerant charged thermosyphoning solar DHW systems  

SciTech Connect

The recent introduction of refrigerants into the realm of passive solar technologies has provided some advantages in performance over the typical liquid solar domestic hot water system. These advantages can be offset by the lack of familiarity by designers or installers with the operation, layout or components of a phase-change thermosyphon water heater. The considerations which were evaluated in the design and installation of a passive solar domestic hot water system in Golden, Colorado, are described. A discussion of collector selection, storage and heat exchanger design, refrigerant type selection, system integration design, and refrigeration requirements is presented.

DeAngelis, M.; Nordham, D.

1980-01-01T23:59:59.000Z

426

Triple-effect absorption refrigeration system with double-condenser coupling  

DOE Patents (OSTI)

A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

DeVault, Robert C. (Knoxville, TN); Biermann, Wendell J. (Fayetteville, NY)

1993-01-01T23:59:59.000Z

427

Triple-effect absorption refrigeration system with double-condenser coupling  

DOE Patents (OSTI)

A triple effect absorption refrigeration system is provided with a double-condenser coupling and a parallel or series circuit for feeding the refrigerant-containing absorbent solution through the high, medium, and low temperature generators utilized in the triple-effect system. The high temperature condenser receiving vaporous refrigerant from the high temperature generator is double coupled to both the medium temperature generator and the low temperature generator to enhance the internal recovery of heat within the system and thereby increase the thermal efficiency thereof.

DeVault, R.C.; Biermann, W.J.

1993-04-27T23:59:59.000Z

428

Thermal Analysis of Refrigeration Systems Used for Vaccine ...  

Science Conference Proceedings (OSTI)

Page 1. Thermal Analysis of Refrigeration Systems Used for Vaccine Storage ... Suitability of commercial refrigerators for vaccine storage not ...

2012-08-03T23:59:59.000Z

429

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

430

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

431

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

432

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

433

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

434

International Refrigeration: Order (2012-CE-1510)  

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

DOE ordered International Refrigeration Products to pay an $8,000 civil penalty after finding International Refrigeration had failed to certify that certain room air conditioners comply with the applicable energy conservation standard.

435

Cospolich Refrigerator: Order (2013-CE-5314)  

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

DOE ordered Cospolich Refrigerator Co, Inc. to pay a $8,000 civil penalty after finding Cospolich Refrigerator had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards.

436

Thermoelectric refrigerator having improved temperature stabilization means  

DOE Patents (OSTI)

A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized.

Falco, Charles M. (Woodridge, IL)

1982-01-01T23:59:59.000Z

437

DOE Proposes Higher Efficiency Standards for Refrigerators  

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

New Proposed Standards for Residential Refrigerators and Freezers to Lower Energy Use by as much as Twenty-Five Percent

438

Magnetocaloric Effect and Enhanced Refrigeration effectiveness in ...  

Science Conference Proceedings (OSTI)

Presentation Title, Magnetocaloric Effect and Enhanced Refrigeration effectiveness in ... Industrial Needs and Applications for Soft Magnetic Materials · Industrial ...

439

Optimization of the Refrigerant Capacity in Multiphase ...  

Science Conference Proceedings (OSTI)

Symposium, Magnetic Materials for Energy Applications. Presentation Title, Optimization of the Refrigerant Capacity in Multiphase Magnetocaloric Materials.

440

The Use of Water Vapor as a Refrigerant: Impact of Cycle Modifications on Commercial Viability  

SciTech Connect

This project investigated the economic viability of using water as the refrigerant in a 1000-ton chiller application. The most attractive water cycle configuration was found to be a flash-intercooled, two-stage cycle using centrifugal compressors and direct contact heat exchangers. Component level models were developed that could be used to predict the size and performance of the compressors and heat exchangers in this cycle as well as in a baseline, R-134a refrigeration cycle consistent with chillers in use today. A survey of several chiller manufacturers provided information that was used to validate and refine these component models. The component models were integrated into cycle models that were subsequently used to investigate the life-cycle costs of both an R-134a and water refrigeration cycle. It was found that the first cost associated with the water as a refrigerant cycle greatly exceeded the savings in operating costs associated with its somewhat higher COP. Therefore, the water refrigeration cycle is not an economically attractive option to today's R-134a refrigeration system. There are a number of other issues, most notably the requirements associated with purging non-condensable gases that accumulate in a direct contact heat exchanger, which will further reduce the economic viability of the water cycle.

Brandon F. Lachner, Jr.; Gregory F. Nellis; Douglas T. Reindl

2004-08-30T23:59:59.000Z