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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.


1

16 Heat Transfer and Air Flow in a Domestic Refrigerator  

E-Print Network [OSTI]

445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel........................................................................447 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity

Paris-Sud XI, Université de

2

A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus  

SciTech Connect (OSTI)

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

3

Refrigerant charge management in a heat pump water heater  

DOE Patents [OSTI]

Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, methods of managing refrigerant charge, and methods for heating and cooling a space and heating water. Various embodiments deliver refrigerant gas to a heat exchanger that is not needed for transferring heat, drive liquid refrigerant out of that heat exchanger, isolate that heat exchanger against additional refrigerant flowing into it, and operate the heat pump while the heat exchanger is isolated. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled or adjusted by controlling how much liquid refrigerant is driven from the heat exchanger, by letting refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and segments of refrigerant conduit can be interconnected with various components.

Chen, Jie; Hampton, Justin W.

2014-06-24T23:59:59.000Z

4

Waste Heat Recovery from Refrigeration  

E-Print Network [OSTI]

heat recovery from refrigeration machines is a concept which has great potential for implementation in many businesses. If a parallel requirement for refrigeration and hot water exists, the installation of a system to provide hot water as a by...

Jackson, H. Z.

1982-01-01T23:59:59.000Z

5

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

SciTech Connect (OSTI)

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

6

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

SciTech Connect (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

7

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

E-Print Network [OSTI]

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

Kandlikar, Satish

8

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

E-Print Network [OSTI]

as other types of air source heat pumps, VRF systems needconventional packaged air source heat pumps. Typical GSHPis basically an air source heat pump), especially when the

Hong, Tainzhen

2010-01-01T23:59:59.000Z

9

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

E-Print Network [OSTI]

tool for geothermal water loop heat pump systems, 9thInternational IEA Heat Pump Conference, Zrich, Switzerland,Performance of ground source heat pump system in a near-zero

Hong, Tainzhen

2010-01-01T23:59:59.000Z

10

Natural Refrigerant (R-729) Heat Pump  

Energy Savers [EERE]

Manufactured in the U.S. 2 Problem Statement * Current commercial and industrial heat pumps - Poor coefficient of performance (COP) at low temperatures * HFC refrigerant...

11

Analysis of heat recovery in supermarket refrigeration system using carbon dioxide as refrigerant.  

E-Print Network [OSTI]

?? The aim of this study is to investigate the heat recovery potential in supermarket refrigeration systems using CO2 as refrigerants. The theoretical control strategy (more)

Abdi, Amir

2014-01-01T23:59:59.000Z

12

Air Conditioning Heating and Refrigeration Institute Comment  

Broader source: Energy.gov [DOE]

These comments are submitted by the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) in response to the U.S. Department of Energys (DOE) notice in the July 3, 2014 Federal Register...

13

The Impact of Refrigerant Charge, Air Flow and Expansion Devices on the Measured Performance of an Air-Source Heat Pump Part I  

SciTech Connect (OSTI)

This paper describes extensive tests performed on a 3-ton R-22 split heat pump in heating mode. The tests contain 150 steady-state performance tests, 18 cyclic tests and 18 defrost tests. During the testing work, the refrigerant charge level was varied from 70 % to 130% relative to the nominal value; the outdoor temperature was altered by three levels at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C); indoor air flow rates ranged from 60% to 150% of the rated air flow rate; and the expansion device was switched from a fixed-orifice to a thermal expansion value. Detailed performance data from the extensive steady state cyclic and defrost testing performed were presented and compared.

Shen, Bo [ORNL

2011-01-01T23:59:59.000Z

14

Waste Heat Recapture from Supermarket Refrigeration Systems  

SciTech Connect (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

15

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

16

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

17

Literature survey of heat transfer enhancement techniques in refrigeration applications  

SciTech Connect (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

18

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

19

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

20

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

SciTech Connect (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

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

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...

Nutter, Darin Wayne

22

HVAC's Variable Refrigerant Flow (VRF) Technology  

E-Print Network [OSTI]

1 Comfort by Design Steve Jones Commercial Sales Manager for Mitsubishi Southwest Business Unit HVAC?s Variable Refrigerant Flow (VRF) Technology HVAC Industry Overview HVAC Market Dollar Volume $18 Billion Source:;NABH Research....2M Systems Ductless is a small percent of the U.S. HVAC market but current building and energy usage trends indicate a large growth opportunity Determining the Proper Application Worldwide Usage-Opportunity Window Unitary Chillers...

Jones, S.

2012-01-01T23:59:59.000Z

23

Helium Refrigerator Design for Pulsed Heat Load in Tokamaks  

SciTech Connect (OSTI)

Nuclear fusion reactors of the Tokamak type will be operated in a pulsed mode requiring the helium refrigerator to remove periodically large heat loads in time steps of approximately one hour. What are the necessary steps for a refrigerator to cope with such load variations?A series of numerical simulations has been performed indicating the possibility of an active refrigerator control with low exergetic losses. A basic comparison is made between the largest existing refrigerator sizes and the size required to service for example the ITER requirements.

Kuendig, A.; Schoenfeld, H. [Linde Kryotechnik AG, Dattlikonerstrasse 5, CH-8422 Pfungen (Switzerland)

2006-04-27T23:59:59.000Z

24

Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants  

E-Print Network [OSTI]

1 Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants Paul BYRNE and to install heat pumps in unoccupied spaces. Nevertheless manufacturers keep working on components for hydrocarbons. In the frame of a research project on heat pumps for simultaneous heating and cooling, an R407C

Paris-Sud XI, Université de

25

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

SciTech Connect (OSTI)

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

26

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

27

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

E-Print Network [OSTI]

Electric 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 of vapor compression system configurations including multi-functional integrated heat pumps, multi

Oak Ridge National Laboratory

28

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...

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

1980-01-01T23:59:59.000Z

29

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...

Rodriguez, Angel Gerardo

2012-06-07T23:59:59.000Z

30

Reliability of Heat Pumps Containing R410-A Refrigerant  

E-Print Network [OSTI]

Ester (POE) oils used with HFC refrigerants will break down into acid and alcohol when exposed to heat. Manufacturers have many tools to establish reliability of a product prior to mass production. Units and compressors can be nm on life tests. Prototype...

McJimsey, B. A.; Cawley, D.

1998-01-01T23:59:59.000Z

31

Waste-heat-driven refrigeration plants for freezer trawlers  

SciTech Connect (OSTI)

An analysis is made of the possibility of utilizing waste heat from a proposed gas-turbine fishing-vessel propulsion engine to power a refrigeration plant. On the basis of superior volume, maintenance and reliability, and cost and availability, the ammonia-water absorption system is chosen over the other waste-heat-driven option considered. It is found to be comparable in volume and in maintenance and reliability to the conventional vapor-compression system.

Kellen, A.D.

1986-01-01T23:59:59.000Z

32

Analysis of simultaneous cooling and heating in supermarket refrigeration systems.  

E-Print Network [OSTI]

?? In this master thesis project, conventional supermarket refrigeration systems using R404A are compared with refrigeration system solutions using natural refrigerants such as carbon dioxide (more)

Marigny, Johan

2011-01-01T23:59:59.000Z

33

Miniaturized Air to Refrigerant Heat Exchangers | Department...  

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

- Grenada, MS -- International Copper Association - New York, NY -- Wieland - Ulm, Germany -- Heat Transfer Technologies - Abington, PA DOE Funding: 1,500,000 Cost Share: NA...

34

Study on Alternative Refrigerants for Direct Expansion Solar Assisted Heat Pump System  

Science Journals Connector (OSTI)

This paper reports the investigation results of the possibilities for using pure and mixed refrigerants as working fluids to replace R22 for the DX-SAHP systems. Firstly, pure refrigerants are compared in terms of COP, discharge temperature and mass ... Keywords: direct expansion, heat pump, refrigerant, steady state, simulation

Hong Li

2012-05-01T23:59:59.000Z

35

DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT  

E-Print Network [OSTI]

1 DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT CHAMOUN MARWAN to improve industrial energy efficiency, the development of a high temperature heat pump using water vapor as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump

Paris-Sud XI, Université de

36

Study of Low Global Warming Potential Refrigerants in Heat Pump System for Residential Applications.  

E-Print Network [OSTI]

??R410A is one of the major refrigerants used for air conditioning and heat pump systems in residential applications. It has zero ODP but its GWP (more)

Barve, Atharva

2012-01-01T23:59:59.000Z

37

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

Broader source: Energy.gov [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...

38

Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery  

SciTech Connect (OSTI)

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

39

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

SciTech Connect (OSTI)

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

40

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

E-Print Network [OSTI]

COFELY Refrigeration | Rüdiger Roth | European Heat Pump Summit 2013 Seite 1 Copyright©COFELYDeutuschlandGmbH2009.AlleRechtevorbehalten. #12;COFELY Refrigeration | Rüdiger Roth | European Heat Pump Summit 2013 Campaign Spectrum: Heat pump with speed controlled screw compressor #12;COFELY Refrigeration | Rüdiger Roth

Oak Ridge National Laboratory

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

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

E-Print Network [OSTI]

RefrigerationRefrigerationRefrigeration coursecourse # 424503.0# 424503.0 v.v. 20122012 8. Heat pumps, heat pipes, cold thermal energy storage Ron on a vapour-compression cycle) /heat_pump.g Heat pumps make use of low- temperature (waste) heat, replacing/vcmfiles/ electricity!) for heating and air conditioning purposes Heat pumps became popular in ://www.bge.c Heat pumps

Zevenhoven, Ron

42

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

Broader source: Energy.gov [DOE]

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

43

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

SciTech Connect (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

44

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

45

LPG recovery from refinery flare by waste heat powered absorption refrigeration  

SciTech Connect (OSTI)

A waste heat powered ammonia Absorption Refrigeration Unit (ARU) has commenced operation at the Colorado Refining Company in Commerce City, Colorado. The ARU provides 85 tons of refrigeration at 30 F to refrigerate the net gas/treat gas stream, thereby recovering 65,000 barrels per year of LPG which formerly was flared or burned as fuel. The ARU is powered by the 290 F waste heat content of the reform reactor effluent. An additional 180 tons of refrigeration is available at the ARU to debottleneck the FCC plant wet gas compressors by cooling their inlet vapor. The ARU is directly integrated into the refinery processes, and uses enhanced, highly compact heat and mass exchange components. The refinery's investment will pay back in less than two years from increased recovery of salable product, and CO{sub 2} emissions are decreased by 10,000 tons per year in the Denver area.

Erickson, D.C.; Kelly, F.

1998-07-01T23:59:59.000Z

46

Planetary heat flow measurements  

Science Journals Connector (OSTI)

...ESA's Rosetta mission towards comet Churyumov-Gerasimenko. It...Heat flow measurements on comets have a different motivation...penetrator is by no means limited to comets; it has also been tested in...measurement. Currently, a landing on Mercury within the framework...

2005-01-01T23:59:59.000Z

47

IEA Heat Pump Conference 2011, 16 -19 May 2011, Tokyo, Japan ON SIDE REFRIGERANT MEASUREMENT OF HEAT PUMP  

E-Print Network [OSTI]

- 1 - 10th IEA Heat Pump Conference 2011, 16 - 19 May 2011, Tokyo, Japan ON SIDE REFRIGERANT MEASUREMENT OF HEAT PUMP SEASONAL PERFORMANCES C. T. Tran, PhD student, Centre for Energy and Processes, MINES, Research Engineer, ENERBAT, Electricity of France R&D, Moret/Loing, France Abstract Heat pump systems have

Paris-Sud XI, Université de

48

Regeneration tests of a room temperature magnetic refrigerator and heat pump  

E-Print Network [OSTI]

A magnetic heat pump apparatus consisting of a solid magnetic refrigerant, gadolinium, and a liquid regenerator column of ethanol and water has been tested. Utilizing a 7T field, it produced a maximum temperature span of 80 K, and in separate tests, a lowest temperature of 241 K and a highest temperature of 328 K. Thermocouples, placed at intervals along the regenerator tube, permitted measurement of the temperature distribution in the regenerator fluid. No attempt was made to extract refrigeration from the device, but analysis of the temperature distributions shows that 34 watts of refrigeration was produced.

Brown, G V

2014-01-01T23:59:59.000Z

49

Solid-Vapor Sorption Refrigeration Systems  

E-Print Network [OSTI]

adsorbents in heat pump cycles: 1. A high usable refrigerant mass per unit mass of adsorbent. 2. A high energy of adsorption and desorption. 3. Heat flows and composition changes occur at constant temperature. The advantages of complex compounds... 2. Useable refrigerant densities. Summarizing, complex compound exhibit inherent characteristics which make them ideal adsorbents in heat pump cycles: 1. A high usable refrigerant mass per unit mass of adsorbent. 2. A high energy of adsorption...

Graebel, W.; Rockenfeller, U.; Kirol, L.

50

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

Broader source: Energy.gov [DOE]

This document is a comment submitted by the Air Conditioning, Heating and Refrigeration Institute (AHRI) regarding the Energy Star Verification Testing Program

51

A refrigerator-heat-pump desalination scheme for fresh-water and salt recovery  

Science Journals Connector (OSTI)

This study concerns a refrigerator-heat-pump desalination scheme (RHPDS), which allows energy-efficient recovery of fresh water and salt from the sea. In this scheme, a salt-water chamber is continuously refilled with sea water via atmospheric pressure. Sea water is evaporated into a vacuum chamber and the water vapor is condensed on top of a fresh-water chamber. A refrigerator-heat-pump circuit maintains the two water chambers at suitably different operating temperatures and allows efficient recovery of the latent heat of condensation. The scheme is analyzed with special consideration to potential exploitation of renewable energy sources such as solar and wind energy.

M. Reali

1984-01-01T23:59:59.000Z

52

2014-04-28 Issuance: Certification of Commercial HVAC, Water Heating, and Refrigeration Equipment; Final Rule  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register final rule regarding the certification of commercial heating, ventilation, and air-conditioning (HVAC), water heating (WH), and refrigeration (CRE) equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on April 28, 2014.

53

An experimental study of waste heat recovery from a residential refrigerator  

SciTech Connect (OSTI)

This paper describes the design, construction, and testing of an integrated heat recovery system which has been designed both to enhance the performance of a residential refrigerator and simultaneously to provide preheated water for an electric hot water heater. A commercial, indirect-heated hot water tank was retrofitted with suitable tubing to permit it to serve as a water cooled condenser for a residential refrigerator. This condenser operates in parallel with the air-cooled condenser tubing of the refrigerator so that either one or the other is active when the refrigerator is running. The refrigerator was housed in a controlled-environment chamber, and it was instrumented so that its performance could be monitored carefully in conjunction with the water pre-heating system. The system has been tested under a variety of hot water usage protocols, and the resulting data set has provided significantly insight into issues associated with commercial implementation of the concept. For the case of no water usage, the system was able to provide a 35 C temperature rise in the storage tank after about 100 hours of continuous operation, with no detectable deterioration of the refrigerator performance. Preliminary tests with simulations of high water usage, low water usage, and family water usage indicate a possible 18--20% energy savings for hot water over a long period of operation. Although the economic viability for such a system in a residential environment would appear to be sub-marginal, the potential for such a system associated with commercial-scale refrigeration clearly warrants further study, particularly for climates for which air conditioning heat rejection is highly seasonal.

Clark, R.A.; Smith, R.N.; Jensen, M.K. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1996-12-31T23:59:59.000Z

54

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

SciTech Connect (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

55

Novel 4-Way Refrigerant Reversing Valve for Heat Pumps  

SciTech Connect (OSTI)

This project is nearing completion. Since the last progress report (November, 1999), all experimental tests have been completed. Preliminary analysis shows the refrigerant pressure drops through the reversing valve were reduced by an average of about 60{percent}, when compared to traditional reversing valves. Also, the prototype reversing valve reduced the overall coefficient of performance (COP) by an average of only 0.45{percent}.

Darin W. Nutter

2000-02-17T23:59:59.000Z

56

Two-Phase Flow of Two HFC Refrigerant Mixtures Through Short Tube Orifices, Draft Final Report  

E-Print Network [OSTI]

The present study presents data for flow of two refrigerant mixtures through short tube orifices. The two mixtures were R3211251134a (23%/25%/52% on a mass percentage basis) and R321125 (50%/50%). The following presents results for the flow...

Payne, W. V.; O'Neal, D. L.

1994-01-01T23:59:59.000Z

57

Cooling power of the dilution refrigerator with a perfect continuous counterflow heat exchanger  

Science Journals Connector (OSTI)

The model of the perfect continuous counterflow heat exchanger introduced by Frossati et al. to describe the performance of dilution refrigerators is solved rigorously with the proper boundary condition. Unlike the original solution by Frossati et al. the present solution gives the refrigerator cooling power which is in good agreement with experimental data over the entire temperature range. The analysis of the cooling power using the present result allows more detailed evaluation of the refrigerator performance than has been possible with the analysis of the base temperature. An approximate expression for the cooling power is discussed which simplifies the prediction of the cooling rate of a large thermal load such as a copper nuclear?demagnetization stage.

Y. Takano

1994-01-01T23:59:59.000Z

58

Earth's Crust: Heat Flow Relationships  

Science Journals Connector (OSTI)

... of heat flow through the Earth's surface at any point requires two measurements, the geothermal gradient itself and the thermal conductivity of the adjacent rocks. In the oceanic crust, ... variations in heat flow from point to point are governed essentially by variations in the geothermal gradient. In continents, however, the story is different. Correlation and regression analyses carried ...

Our Geomagnetism Correspondent

1970-07-11T23:59:59.000Z

59

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

Broader source: Energy.gov [DOE]

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

60

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...

Zuo, Z.; Hu, W.

2006-01-01T23:59:59.000Z

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

HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL...  

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

of the updated Energy Conservation Standards for Air Conditioners, Furnaces and Heat Pumps. DOE EX Parte Memo.pdf More Documents & Publications 3rd Semi-Annual Report to...

62

Direct Refrigeration from Heat Recovery Using 2-Stage Absorption Chillers  

E-Print Network [OSTI]

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...

Hufford, P. E.

1983-01-01T23:59:59.000Z

63

Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow...  

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

Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer, Longer-lasting Batteries Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer,...

64

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

E-Print Network [OSTI]

Refinery Waste Heat Ammonia Absorption Refrigeration Plant (WHAARp?) Recovers LPG's and Gasoline, Saves Energy, and Reduces Air Pollution Benjamin Brant Sabine Brueske Donald Erickson Riyaz Papar Planetec Planetec Energy Concepts Company Energy... in Denver, Colorado. The Waste Heat Ammo nia Absorption Refrigeration Plant (WHAARP?) is based on a patented process and cycle design developed by Energy Concepts Co. (ECC) to cost effectively re cover 73,000 barrels a year of salable LPGs and gasoline...

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

65

Comfort by Design: An Introduction to HVAC's Variable Refrigerant Flow (VRF) Technology  

E-Print Network [OSTI]

Comfort by Design An Introduction to HVACs Variable Refrigerant Flow (VRF) Technology Keith Reihl kreihl@hvac.mea.com ESL-KT-14-11-13 CATEE 2014: Clean Air Through Efficiency Conference, Dallas, Texas Nov. 18-20 HVAC Market Overview 0% 27% 9% 5% 4... Through Efficiency Conference, Dallas, Texas Nov. 18-20 How LOUD is a traditional HVAC unit? 33 dB(A) Library 50 dB(A) Refrigerator 60 dB(A) Conversation 78 dB(A) Vacuum 25 dB(A) Recording Studio 65-75 dB(A) Residential 3-ton HVAC Unit How Q IET are VRF...

Reihl,K.

2014-01-01T23:59:59.000Z

66

Heat-machine control by quantum-state preparation: from quantum engines to refrigerators  

E-Print Network [OSTI]

We explore the dependence of the performance bounds of heat engines and refrigerators on the initial quantum state and the subsequent evolution of their piston, modeled by a quantized harmonic oscillator. Our goal is to provide a fully quantized treatment of self-contained (autonomous) heat machines, as opposed to their prevailing semiclassical description that consists of a quantum system alternately coupled to a hot or a cold heat bath, and parametrically driven by a classical time-dependent piston or field. Here by contrast, there is no external time-dependent driving. Instead, the evolution is caused by the stationary simultaneous interaction of two heat baths (having distinct spectra and temperatures) with a single two-level system that is in turn coupled to the quantum piston. The fully quantized treatment we put forward allows us to investigate work extraction and refrigeration by the tools of quantum-optical amplifier and dissipation theory, particularly, by the analysis of amplified or dissipated phase-plane quasiprobability distributions. Our main insight is that quantum states may be thermodynamic resources and can provide a powerful handle, or control, on the efficiency of the heat machine. In particular, a piston initialized in a coherent state can cause the engine to produce work at an efficiency above the Carnot bound in the linear amplification regime. In the refrigeration regime, the coefficient of performance can transgress the Carnot bound if the piston is initialized in a Fock state. The piston may be realized by a vibrational mode, as in nanomechanical setups, or an electromagnetic field mode, as in cavity-based scenarios.

David Gelbwaser-Klimovsky; Gershon Kurizki

2015-01-31T23:59:59.000Z

67

2014-06-23 Issuance: Energy Conservation Standards for Walk-in Coolers and Freezers; Air-Conditioning, Heating, & Refrigeration Institute Petition for Reconsideration  

Broader source: Energy.gov [DOE]

This document is the agency response to the Energy Conservation Standards for Walk-in Coolers and Freezers; Air-Conditioning, Heating, & Refrigeration Institute Petition for Reconsideration.

68

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

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference...

69

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

70

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

E-Print Network [OSTI]

, 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

71

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

72

2014-02-07 Issuance: Certification of Commercial Heating, Ventilation, and Air-conditioning, Water Heating, and Refrigeration Equipment; Notice of Proposed Rulemaking  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register notice of proposed rulemaking regarding certification of commercial heating, ventilation, and air-conditioning, water-heating, and refrigeration equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on February 7, 2014.

73

9.11.2014bo Akademi Univ -Thermal and Flow Engineering -Piispankatu 8, 20500 Turku 1/65 2. Vapour-compression refrigeration  

E-Print Network [OSTI]

. Vapour-compression refrigeration processes Ron Zevenhoven ?bo Akademi University Thermal and Flow") Refrigeration course # 424503.0 v. 2014 ?A 424503 Refrigeration / Kylteknik 9.11.2014?bo Akademi Univ - Thermal of a refrigerant fluid Picture: ?B98 liquid-vapour saturation dome 1-2 and 3-4: reversible and isothermal 2-3 and 4

Zevenhoven, Ron

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 μcal/gm-yr, which is slightly

75

Geothermal Heat Flow and Existing Geothermal Plants | Department...  

Energy Savers [EERE]

Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Geothermal Plants Geothermal Heat Flow and Existing Plants With plants in development. Click...

76

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

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.

1987-06-23T23:59:59.000Z

78

Cryogenic Fluid Flow Heat Transfer in a Porous Heat Exchanger  

Science Journals Connector (OSTI)

The recent utilization of porous heat exchangers in various key industries has aroused considerable interest in the heat transfer and fluid dynamics processes in channel flows involving suction...1], suction with...

L. L. Vasiliev; G. I. Bobrova; S. K. Vinokurov

1978-01-01T23:59:59.000Z

79

Heat flow on the southern Colorado Plateau  

Science Journals Connector (OSTI)

Heat-flow data from the study area in the southern Colorado Plateau indicate a pattern of local anomalies having relatively high heat flow superimposed on a regional, intermediate heat-flow setting. While many of the conventional heat-flow data are relatively shallow and may be perturbed by groundwater circulation, bottom-hole temperature data from two relatively deep petroleum exploration drill holes near the southern plateau periphery yield intermediate heat-flow estimates. The mean heat flow within the volcanically active Jemez zone does not appear to be significantly greater than the mean heat flow for the remainder of the study area. This is due to the presence of high heat-flow values outside the Jemez zone. Sites with relatively high heat flow located towards the plateau interior and away from recent volcanic activity of the Jemez zone may reflect magma intrusion and/or groundwater movement along crustal zones of weakness associated with Laramide deformation (monoclines). The heat-flow data are consistent with coal maturation data, which suggest that any regional post-Cretaceous thermal events that may be associated with the southern Plateau boundary have been initiated relatively recently, or are occurring at relatively great depths, or are occurring south of the Jemez lineament.

Jeffrie Minier; Marshall Reiter

1991-01-01T23:59:59.000Z

80

GEA Refrigeration Technologies / GEA Refrigeration Germany GmbH Wolfgang Dietrich / Dr. Ole Fredrich  

E-Print Network [OSTI]

GEA Refrigeration Technologies / GEA Refrigeration Germany GmbH Wolfgang Dietrich / Dr. Ole Technologies3 Achema 2012 // heat pumps using ammonia Industrial demand on heat in Germany Heatdemandin

Oak Ridge National Laboratory

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

Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger  

E-Print Network [OSTI]

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

Singh, K. P.

1979-01-01T23:59:59.000Z

82

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

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

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

83

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

Broader source: Energy.gov [DOE]

This document provides Public Information for Convening Interviews for US Department of Energys Regulatory Negotiations Convening on Commercial Certification for Heating, Ventilating, Air-Conditioning, and Refrigeration Equipment

84

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...

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

2006-01-01T23:59:59.000Z

85

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]

, and relative humidity on the COP and capacity of the test unit. The refrigerant charge was held constant#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

Oak Ridge National Laboratory

86

Proc. 5th Minsk International Seminar (Heat Pipes, Heat Pumps and Refrigerators), Minsk, Belarus, 2003. 21 7+( '(),1,7,21 2) 38/6$7,1* +($7 3,3(6 $1 29(59,(  

E-Print Network [OSTI]

Proc. 5th Minsk International Seminar (Heat Pipes, Heat Pumps and Refrigerators), Minsk, Belarus)-711-685-2142, Fax: (+49)-711-685-2010, E-mail: khandekar@ike.uni-stuttgart.de $EVWUDFW Pulsating heat pipes (PHPs) have emerged as interesting alternatives to conventional heat transfer technologies. These simple

Khandekar, Sameer

87

Refrigeration monitor and alarm system  

SciTech Connect (OSTI)

A monitor is described for a refrigeration system including a heat reclaiming system coupled therewith, comprising: a sensor positioned to detect the level of liquid state refrigerant in the system and provide an electrical output signal therefrom; a digital display for displaying the refrigerant level; first circuit means coupling the digital display to the sensor for actuating the digital display; and lockout means coupled with the sensor for deactivating the heat reclaiming system when a preselected refrigerant level is reached.

Branz, M.A.; Renaud, P.F.

1986-09-23T23:59:59.000Z

88

An evaluation of heat flow transducers as a means of determining soil heat flow  

E-Print Network [OSTI]

provided to the Micrometeorology Section, Department of Oceanography and Meteorology, ARM College of Texas by the Signal Corps of the United States Army, under Contract No. DA 36-039 AMC-02195 (E). The heat flow plates used in this study were provided... surface soil heat flow. The results show that acceptable performance of the plates in the measurement of heat flow is possible although in general should not be expected without thorough testing, and even then there are restrictive considerations...

King, Barney L. D

2012-06-07T23:59:59.000Z

89

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

90

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

SciTech Connect (OSTI)

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

91

Effects of refrigerant charge and structural parameters on the performance of a direct-expansion solar-assisted heat pump system  

Science Journals Connector (OSTI)

Abstract The direct-expansion solar-assisted heat pump (DX-SAHP) is widely studied as a refrigeration system, which can supply hot water for domestic use during the whole year. The system refrigerant charge and structure parameters are believed to have a great effect on the cycling thermal performance. The refrigerant mass charge including two-phase and single-phase in heat exchangers and pipes is calculated with distributed and lumped parameter approach mathematical models, respectively. Based on the system simulation program, the refrigerant distribution characteristics and system performance under varied structural parameters are obtained. The mathematical calculation results show that the 70%80% refrigerant charge exists in the condenser and collector; the optimum refrigerant charge, solar collector area, condenser pipe length and condenser internal diameter for the system are 1.651.75kg, 6.0m2, 70m and 9mm, respectively. In the optimum parameters, the better system performance and feasible cost can be achieved.

D. Zhang; Q.B. Wu; J.P. Li; X.Q. Kong

2014-01-01T23:59:59.000Z

92

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

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

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

93

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

SciTech Connect (OSTI)

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

94

Cryogenic heat exchanger with turbulent flows  

Science Journals Connector (OSTI)

An evaporator-type cryogenic heat exchanger is designed and built for introducing fluidsolid heat exchange phenomena to undergraduates in a practical and efficient way. The heat exchanger functions at liquid nitrogen temperature and enables cooling of N2and He gases from room temperatures. We present first the experimental results of various parameters which characterize the heat exchanger (efficiency, number of transfer units, heat exchange coefficient, etc) as a function of the mass flow rate of the gas to be cooled. An analysis of the NuRe diagram is also presented. All experiments were conducted with N2gas. The scope of this tool is readily extended to research purposes.

Jay Amrit; Christelle Douay; Francis Dubois; Grard Defresne

2012-01-01T23:59:59.000Z

95

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

96

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

97

Plume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a,b  

E-Print Network [OSTI]

to follow a power-law size distribution, estimated a plume heat flux as high as 35% of surface heat fluxPlume heat flow is much lower than CMB heat flow Eric Mittelstaedt a,*, Paul J. Tackley a, of the heat conducted across the CMB. Here this assumption is explored using numerical convection models

Tackley, Paul J.

98

Corrosion aspects in indirect systems with secondary refrigerants.  

E-Print Network [OSTI]

?? Aqueous solutions of organic or inorganic salts are used as secondary refrigerants in indirect refrigeration systems to transport and transfer heat. Water is known (more)

Ignatowicz, Monika

2008-01-01T23:59:59.000Z

99

Hydrodynamics, heat transfer and flow boiling instabilities in microchannels  

E-Print Network [OSTI]

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

Barber, Jacqueline Claire

2010-01-01T23:59:59.000Z

100

Interpretive geothermal heat flow map of Colorado | Open Energy...  

Open Energy Info (EERE)

Interpretive geothermal heat flow map of Colorado Jump to: navigation, search OpenEI Reference LibraryAdd to library Map: Interpretive geothermal heat flow map of ColoradoInfo...

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

Heat Flow in the Hungarian Basin  

Science Journals Connector (OSTI)

... the basin is deep and the gradient is between 40 and 45 C/km. This geothermal low may be characterized by 1-4-1-6 [jical/cm2 sec except if ... is about 1*5 sec can bo considered as the Western boundary of the Hungarian geothermal anomaly, since heat flow diminishes from that line in the north-west direction to ...

T. BOLDIZSR

1964-06-27T23:59:59.000Z

102

Radio frequency (RF) heated supersonic flow laboratory  

SciTech Connect (OSTI)

A unique supersonic flow apparatus which employs an inductively-coupled, radio frequency (RF) torch to supply high enthalpy source gas to the nozzle inlet is described. The main features of this system are the plasma tube, a cooled nozzle assembly, and a combustion/expansion chamber with a heat exchanger. A description of these components with current test data is presented. In addition, a discussion of anticipated experiments utilizing this system is included.

Wantuck, P.; Watanabe, H.

1990-01-01T23:59:59.000Z

103

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 geometry the flow field influence on the local heat transfer distribution on an evenly cooled scraped heat loss heat loss to the surroundings stst stainless steel plate lc thermo-chromic liquid crystal

Boyer, Edmond

104

FLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS  

E-Print Network [OSTI]

= heat, f = LO-mode, g = LO, h = LA-mode, i = negligible, j = remote heat sink 7/ 70 #12;Heat conductionFLUID MECHANICS AND HEAT TRANSFER OF ELECTRON FLOW IN SEMICONDUCTORS Mihir Sen Department · Shallow water analogy · Vorticity dynamics · Linear stability analysis · Numerical simulations of heat

Sen, Mihir

105

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

106

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

E-Print Network [OSTI]

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

Aussillous, Pascale

107

EHD enhancement of boiling/condensation, heat transfer of alternate refrigerants. Final Report for 1993-1999  

SciTech Connect (OSTI)

The goal was to address the feasibility of frost control by the EHD technique for operating conditions and geometries of significance to refrigeration. The objective of the experimental investigation was to demonstrate by experiment the feasibility of the EHD technique for control of frost on a cold surface under operating conditions of direct significance to refrigeration applications.

Ohadi, M. M.

1999-09-01T23:59:59.000Z

108

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications  

E-Print Network [OSTI]

MERLOT: a model for flow and heat transfer through porous media for high heat flux applications A Abstract Fusion power plant studies have found helium to be an attractive coolant based on its safety tend to provide modest heat transfer performance due to their inherently low heat capacity and heat

Raffray, A. René

109

IIR Workshop on Refrigerant Charge Reduction in Refrigerating Systems Corresponding author: P. Leblay  

E-Print Network [OSTI]

3rd IIR Workshop on Refrigerant Charge Reduction in Refrigerating Systems Corresponding author: P on the refrigerant side and louver fins on the air side. The flat tubes are grouped within a header, to use the heat exchangers with round tubes, such as charge reduction and higher heat transfer efficiency. But a reduced

Paris-Sud XI, Université de

110

Heat flow in the postquasistatic approximation  

SciTech Connect (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

111

Heat flow in the postquasistatic approximation  

E-Print Network [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 which 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 which corresponds to a highly compressed Fermi gas, only the outermost shell can evolve with a shorter hydrodynamic time scale.

B. Rodrguez-Mueller; C. Peralta; W. Barreto; L. Rosales

2010-05-10T23:59:59.000Z

112

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

113

Temperature, heat flow maps and temperature gradient holes |...  

Open Energy Info (EERE)

Temperature, heat flow maps and temperature gradient holes Author T. G. Zacharakis Organization Colorado Geological Survey in Cooperation with the U.S. Department of Energy...

114

Ch. VII, Temperature, heat flow maps and temperature gradient...  

Open Energy Info (EERE)

Ch. VII, Temperature, heat flow maps and temperature gradient holes Author T. G. Zacharakis Editor T. G. Zacharakis Published Colorado Geological Survey in Cooperation with the...

115

Radiative heat transfer in a flow of rheologically complex fluid  

Science Journals Connector (OSTI)

The problem of complex radiative and convective heat transfer in steady-state generalized Couette flow of a nonlinear viscoplastic fluid is examined.

V. F. Volchenok; Z. P. Shul'man

1980-09-01T23:59:59.000Z

116

Heat Flow Database Expansion for NGDS Data Development, Collection...  

Open Energy Info (EERE)

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...

117

Semiconductor-based optical refrigerator  

DOE Patents [OSTI]

Optical refrigerators using semiconductor material as a cooling medium, with layers of material in close proximity to the cooling medium that carries away heat from the cooling material and preventing radiation trapping. In addition to the use of semiconducting material, the invention can be used with ytterbium-doped glass optical refrigerators.

Epstein, Richard I. (Santa Fe, NM); Edwards, Bradley C. (Nekoosa, WI); Sheik-Bahae, Mansoor (Albuquerque, NM)

2002-01-01T23:59:59.000Z

118

Heat transfer in channel flow of a micropolar fluid  

Science Journals Connector (OSTI)

The study of heat transfer in channel flow has been done by previous authors for Newtonian and elastico-viscous fluids. It is the aim of the present ... the temperature profile for flow of a micropolar fluid in a...

Renuka Rajagopalan; K. S. Bhatnagar

1969-10-01T23:59:59.000Z

119

NICE3: Industrial Refrigeration System  

SciTech Connect (OSTI)

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

120

Heat transfer research on supercritical water flow upward in tube  

SciTech Connect (OSTI)

The experimental research of heat transfer on supercritical water has been carried out on the supercritical water multipurpose test loop with a 7.6 mm upright tube. The experimental data of heat transfer is obtained. The experimental results of thermal-hydraulic parameters on flow and heat transfer of supercritical water show that: Heat transfer enhancement occurs when the fluid temperature reaches pseudo-critical point with low mass flow velocity, and peters out when the mass flow velocity increases. The heat transfer coefficient and Nusselt number decrease with the heat flux or system pressure increases, and increase with the increasing of mass flow velocity. The wall temperature increases when the mass flow velocity decreases or the system pressure increases. (authors)

Li, H. B.; Yang, J. [China Nuclear Power Technology Research Inst., Shenzhen, Guangdong (China); Gu, H. Y.; Zhao, M. [Shanghai Jiao Tong Univ., Shanghai (China); Lu, D. H.; Zhang, J. M.; Wang, F.; Zhang, Y. [China Nuclear Power Technology Research Inst., Shenzhen, Guangdong (China)

2012-07-01T23:59:59.000Z

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.


121

Miniature liquid?3He refrigerator  

Science Journals Connector (OSTI)

The use of a cryopump and high?pressure internal storage of the cryogen makes it possible to miniaturize a one?shot recyclable 3He refrigerator while at the same time improving its performance. Because of their simplified interface requirements such refrigerators are readily incorporated into existing 4He cryostats allowing a convenient extension of their operating range down to 0.3 K. An analysis of the parameters describing refrigerator performance (condensation time heat transfer to the 4He bath lifetime and refrigeration power) leads to the definition of an optimized refrigerator. Measured performance characteristics of a miniature [2?l standard temperature and pressure (STP) of 3He] refrigerator used in laboratory and stratospheric balloon?borne experiments are given.

J. P. Torre; G. Chanin

1985-01-01T23:59:59.000Z

122

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

123

Heat transfer during laminar fluid flow in a pipe with radiative heat removal  

Science Journals Connector (OSTI)

The heat-transfer problem is analyzed for laminar fluid flow in the initial section of a ... pipe having a parabolic entry velocity distribution and heat removal by radiation from the surface of...

Ya. S. Kadaner; Yu. P. Rassadkin; . L. Spektor

1971-01-01T23:59:59.000Z

124

The developing heat transfer and fluid flow in micro-channel heat sink with viscous heating effect  

Science Journals Connector (OSTI)

The numerical modeling of the conjugate heat transfer and fluid flow through the micro-heat sink was presented in the paper, considering the viscous dissipation effect. Three different fluids with temperature dep...

Dorin Lelea; Adrian Eugen Cioabla

2011-07-01T23:59:59.000Z

125

The growth rate of gas hydrate from refrigerant R12  

SciTech Connect (OSTI)

Experimental and theoretical investigations were presented dealing with three phase direct-contact heat transfer by evaporation of refrigerant drops in an immiscible liquid. Refrigerant R12 was used as the dispersed phase, while water and brine were the immiscible continuous phase. A numerical solution is presented to predict the formation rate of gas hydrates in test column. The solution provided an acceptable agreement when compared with experimental results. The gas hydrate growth rate increased with time. It increased with increasing dispersed phase flow rate. The presence of surface-active sodium chloride in water had a strong inhibiting effect on the gas hydrate formation rate. (author)

Kendoush, Abdullah Abbas; Jassim, Najim Abid [Centre of Engineering Physics, Ministry of Sciences and Technology, P.O. Box 765, Baghdad (Iraq); Joudi, Khalid A. [Al-Nahrain University, Baghdad (Iraq)

2006-07-15T23:59:59.000Z

126

Experimental study and analysis on components of a thermoacoustic refrigerator and thermoacoustic prime mover  

SciTech Connect (OSTI)

A thermoacoustic refrigerator and a thermoacoustic prime mover, due to its simple structure, would serve as very desirable systems because thermoacoustic prime movers can be driven with the waste heat such as an exhaust gas from engines, and with heat from the nature such as sunlight and a geothermal heat. The thermoacoustic refrigerator and the thermoacoustic prime mover combined would serve as a perfect cooling system without moving parts, CFC's and HFC's. Thus this Thermoacoustic-driven Thermoacoustic Refrigerator will replace the previous paper compression refrigeration system. The authors set up the thermoacoustic refrigerator and thermoacoustic prime mover to investigate the fundamental characteristics. On the refrigerator tests, dimensions of the stack are varied as a parameter of experiments. As a result, influences of the stack configuration on the performance are confirmed, so the design method for the optimum dimension to attain the large temperature difference can be indicated. About the prime mover tests, fundamental characteristics of stack dimensions is checked. The way to improve the thermal efficiency of the prime mover is mentioned in terms of the operating condition. Numerical calculations about the refrigerator are made which is based on the enthalpy flow model by Radebaugh. The result of calculations has a good agreement in quality with the experimental results, so the propriety of this model is confirmed.

Nohtomi, Makoto; Katsuta, Masafumi

1999-07-01T23:59:59.000Z

127

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

128

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

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

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.

129

2014-09-23 Issuance: Energy Conservation Standard for Walk-in Coolers and Freezers; Air-Conditioning, Heating, & Refrigeration Institute Petition for Reconsideration Notice of Public Meeting  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register notice of public meeting regarding energy conservation standards for walk-in coolers and freezers; Air-Conditioning, Heating, & Refrigeration Institute petition for reconsideration, as issued by the Deputy Assistant Secretary for Energy Efficiency on September 23, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

130

2014-12-22 Issuance: Alternative Efficiency Determination Methods, Basic Model Definition, and Compliance for Commercial HVAC, Refrigeration, and Water Heating Equipment; Final Rule  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register final rule regarding alternative efficiency determination methods, basic model definition, and compliance for commercial HVAC, refrigeration, and water heating equipment , as issued by the Deputy Assistant Secretary for Energy Efficiency on December 22, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

131

Modular thermoacoustic refrigerator  

Science Journals Connector (OSTI)

A thermoacousticrefrigerator was built to explore scaling to large heat flux. The refrigerator was constructed according to a modular design so that various stack heat exchanger and resonator sections are easily interchangeable. The resonator is driven by a commercial 10?in. woofer. Initial tests using pure helium gas as the working fluid and steel honeycomb (0.8?mm cell) for the stack pumped 60 W of heat against a 10?C temperature gradient. Measurements of heat flux and efficiency will be reported as functions of stack structure (e.g. pore size and shape) and will be compared with theoretical predictions.

Steven R. Murrell; George Mozurkewich

1993-01-01T23:59:59.000Z

132

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

133

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

134

Thermoacoustic refrigerator  

DOE Patents [OSTI]

A thermoacoustic device is described 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. 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. 13 figs.

Moss, W.C.

1997-10-07T23:59:59.000Z

135

Numerical Evaluation of Flow and Heat Transfer in Plate-Pin Fin Heat Sinks with Various Pin Cross-Sections  

E-Print Network [OSTI]

Liu, Research on the Heat Transfer and Flow Performance of aCompound Heat Sink, Numer. Heat Transfer A, vol. 55, no. 5,Hand- book of Numerical Heat Transfer, 2nd ed. , chap. 6,

Zhou, Feng; Catton, Ivan

2011-01-01T23:59:59.000Z

136

Heat flow and geothermal studies in the Great Plains  

SciTech Connect (OSTI)

In continental heat flow studies, sedimentary basins are usually avoided because of difficulties in obtaining thermal conductivity measurements and because temperature gradients may contain advective signals caused by moving groundwater. These problems are superimposed in the Denver, Kennedy and Williston Basins where complex geothermal gradients derive both from large contrasts among thermal conductivities of strata and from regional groundwater flow. The occurrence and magnitude of advective heat flow within the Denver, Kennedy and Williston Basins is conceptually consistent with simple models that relate groundwater flow to the piezometric surface and to subsurface structures, i.e., folds and faults. An advective heat flow of +25 mW/m/sup 2/ has been determined for an area in the eastern margin of the Denver Basin, and quantities of +35 mW/m/sup 2/ and +10 MW/m/sup 2/ have been determined respectively for parts of the southeastern and northeastern parts of the Williston Basin. A detailed analysis of bottom hole temperatures obtained from drill holes in the area of the Billings Anticline in the Williston Basin indicates that information on subsurface structures and groundwater flow may be obtained from heat flow studies. Additional information that may be derived from these heat flow studies includes: the occurrence and nature of geothermal resources, oil source rock maturation and secondary migration of petroleum, formation and deposition of strata-bound ores. 43 references.

Gosnold, W.D.; Fischer, D.W.

1985-12-01T23:59:59.000Z

137

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

138

Flow Dynamics and Plasma Heating of Spheromaks in SSX  

Science Journals Connector (OSTI)

We report several new experimental results related to flow dynamics and heating from single dipole-trapped spheromaks and spheromak merging studies at SSX. Single spheromaks (...Phys. Plasmas 13 1...

M. R. Brown; C. D. Cothran; D. H. Cohen; J. Horwitz; V. Chaplin

2008-06-01T23:59:59.000Z

139

Temperatures, heat flow, and water chemistry from drill holes...  

Open Energy Info (EERE)

Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...

140

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport 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.


141

Heating Cooling Flows with Weak Shock Waves  

E-Print Network [OSTI]

The discovery of extended, approximately spherical weak shock waves in the hot intercluster gas in Perseus and Virgo has precipitated the notion that these waves may be the primary heating process that explains why so little gas cools to low temperatures. This type of heating has received additional support from recent gasdynamical models. We show here that outward propagating, dissipating waves deposit most of their energy near the center of the cluster atmosphere. Consequently, if the gas is heated by (intermittent) weak shocks for several Gyrs, the gas within 30-50 kpc is heated to temperatures that far exceed observed values. This heating can be avoided if dissipating shocks are sufficiently infrequent or weak so as not to be the primary source of global heating. Local PV and viscous heating associated with newly formed X-ray cavities are likely to be small, which is consistent with the low gas temperatures generally observed near the centers of groups and clusters where the cavities are located.

W. G. Mathews; A. Faltenbacher; F. Brighenti

2005-11-05T23:59:59.000Z

142

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

143

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

144

Method and apparatus for de-superheating 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. 7 figs.

Zess, J.A.; Drost, M.K.; Call, C.J.

1997-11-25T23:59:59.000Z

145

An Evaluation of Improper Refrigerant Charge on the Performance of a Split System Air Conditioner with a Thermal Expansion Valve  

E-Print Network [OSTI]

State Tests(wet coil). . . .26 2. Steady State & Cyclic (dry coil) TESTS 26 CAPACITY 32 1. Steady State Tests(wet coil)... .32 1.1 Subcooling and Superheat Temperatures 34 1.2 Refrigerant Flow Rate. . . .37 1.3 Sensible Heat Ratio 39 2. Steady State... Typical Refrigerant Temperature Probe . . . .14 2.6 The Fully Charged Subcooling Temperature as a Function of Outdoor Temperature 18 3.1 Refrigerant-Side/Air-Side Capacity Comparison 24 3.2 Total Capacity of the Fully Charged Unit. . . .27 3.3 Energy...

Farzad, M.; O'Neal, D. L.

1989-01-01T23:59:59.000Z

146

Oscillating flow in a stirling engine heat exchanger  

Science Journals Connector (OSTI)

Three heat exchangers exist in modern Stirling engines: a heater, a cooler, and a regenerator. Here a study that deals principally with tubular heaters and coolers is carried out. The calculation procedure for the oscillating flow heat transfer is presented. Literature sources are studied to find the most suitable correlations by comparing them to each other and to the classical turbulent flow correlations encountered in the literature. The enhancement of heat transfer by means of a few circumferential slots inside the tubes and the pressure losses of oscillatory flow are discussed. Non-circular cross-section conduits with rectangular and triangular cross-sections are investigated and compared to the smooth circular tubes. The increment of the performance of an idealised Stirling engine with slotted heat exchanger tubes is compared to the case with smooth ones. The ratio of the gain in the shaft power and pumping losses is 2.22. The Carnot efficiency increment is 2.7%.

M. Kuosa; K. Saari; A. Kankkunen; T.-M. Tveit

2012-01-01T23:59:59.000Z

147

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

148

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...

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

2006-01-01T23:59:59.000Z

149

Heat flow in nonlinear molecular junctions  

E-Print Network [OSTI]

We investigate the heat conduction properties of molecular junctions comprising anharmonic interactions. We find that nonlinear interactions can lead to novel phenomena: it negative differential thermal conductance and heat rectification. Based on analytically solvable models we derive an expression for the heat current that clearly reflects the interplay between anharmonic interactions, strengths of coupling to the thermal reservoirs, and junction asymmetry. This expression indicates that negative differential thermal conductance shows up when the molecule is strongly coupled to the thermal baths, even in the absence of internal molecular nonlinearities. In contrast, diode like behavior is expected for a highly anharmonic molecule with an inherent structural asymmetry. Anharmonic interactions are also necessary for manifesting Fourier type transport. We briefly present an extension of our model system that can lead to this behavior.

Dvira Segal

2005-12-22T23:59:59.000Z

150

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

E-Print Network [OSTI]

when it was located in the downstream, which also weakened heat exchange[5-8], (4)pulse flow might enhance or weaken heat exchange that lied on flow parameter[9-11]. This article made use of FLUENT software to numerical Simulate round... exchange[12]. When adapted FLUENT software, we considered the model was slender tube which had a large gap between length and scale, so we could use double precision solver; In the numerical simulation, the pressure interpolation selected standard...

Chen, Y.; Zhao, J.

2006-01-01T23:59:59.000Z

151

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

152

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

E-Print Network [OSTI]

simulation with credible software programs is a proven feasible way to get quantitative comparison of the energy

Hong, Tainzhen

2010-01-01T23:59:59.000Z

153

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

E-Print Network [OSTI]

the current movement toward net zero energy buildings, manyThe movement towards net zero energy buildings brings

Hong, Tainzhen

2010-01-01T23:59:59.000Z

154

Hot springs, geochemistry, and regional heat flow of northcentral Mexico  

SciTech Connect (OSTI)

To date we have found, sampled and performed chemical analyses on 21 hot springs (T > 30/sup 0/C), 4 hot wells (T > 30/sup 0/C) and 15 warm springs (T = 25 to 30/sup 0/C) from the states of Chihuahua, Coahuila and Sonora, Mexico. Also in order to establish background chemistry, an additional 250 cold wells and springs (T = 12 to 25/sup 0/C) were sampled and analyzed and several hundred water analyses from the several thousand provided by various Mexican agencies were included. The technique of silica geothermometry was used to estimate the regional heat flow of northcentral Mexico. Both the traditional heat flow and the silica heat flow values are generally high and show considerable scatter as is typical of areas having Tertiary and Quaternary volcanic and tectonic activity. Specific areas of high heat flow (> 2.5 HFU) include the Presidio and Los Muertos Bolsons, the Cuidad Chihuahua-Chuatemoc area, the Delicias area, and the area south of the San Bernardino Bolson of southeast Arizona. Areas of lower heat flow (2.0 to 2.5 HFU) include the Jimenez-Camargo region and the area between the Los Muertos and Presidio Bolsons.

Swanberg, C.A.; Marvin, P.R.; Salazar S., L.; Gutierrez, C.G.

1981-10-01T23:59:59.000Z

155

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

E-Print Network [OSTI]

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...

Jeon, Sae Il

2012-10-19T23:59:59.000Z

156

Variable Refrigerant Flow Systems  

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

Resources News & Events Expand News & Events Skip navigation links Smart Grid Demand Response Energy Efficiency Emerging Technologies Current Research Portfolio Behavior Based...

157

Variable Refrigerant Flow HVAC  

E-Print Network [OSTI]

Conference, San Antonio, Texas Dec. 16-18 What do they know that we dont know? Japan 90% Over 7 Million Systems China 86% Over 17 Million Systems Europe 81% Over 7 Million Systems USA 4% .5 Million Systems ESL-KT-13-12-33 CATEE 2013: Clean Air Through...-source VRF IEER 11.5 - 17.7 19.6 9.7 10.3 10.9 10.5 IPLV - 14.2 - - SCHE - - 18.6 N/A Energy Efficiency - commercial EER ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency Conference, San Antonio, Texas Dec. 16-18 More Comfort & Quiet ? 4 ton...

Jones, S.

2013-01-01T23:59:59.000Z

158

Heat Transfer at Low Temperatures between Tube Walls and Gases in Turbulent Flow  

Science Journals Connector (OSTI)

...September 1947 research-article Heat Transfer at Low Temperatures between Tube...counter-flow system to study heat transfer between tube walls and gases at...Determinations on friction accompanying heat transfer with gases in turbulent flow at...

1947-01-01T23:59:59.000Z

159

Brine flow in heated geologic salt.  

SciTech Connect (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

160

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,

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

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

162

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

163

1st TECCS meeting, 26th April 2007 Adsorption Refrigeration  

E-Print Network [OSTI]

TECCS meeting, 26th April 2007 Adsorption refrigerators and heat pumps These machines ADsorb cycles for: Heat pumps Refrigerators Air conditioning Driven by heat from: Fossil fuels Bio fuels Waste of concept forced convection adsorption machine [#1] · Generating temperature 225° C · Heat rejection

Davies, Christopher

164

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

E-Print Network [OSTI]

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

Fullerton, Tracy

2012-02-14T23:59:59.000Z

165

Coupled flow and heat transfer in viscoelastic fluid with CattaneoChristov heat flux model  

Science Journals Connector (OSTI)

Abstract This letter presents a research for coupled flow and heat transfer of an upper-convected Maxwell fluid above a stretching plate with velocity slip boundary. Unlike most classical works, the new heat flux model, which is recently proposed by Christov, is employed. Analytical solutions are obtained by using the homotopy analysis method (HAM). The effects of elasticity number, slip coefficient, the relaxation time of the heat flux and the Prandtl number on velocity and temperature fields are analyzed. A comparison of Fouriers Law and the CattaneoChristov heat flux model is also presented.

Shihao Han; Liancun Zheng; Chunrui Li; Xinxin Zhang

2014-01-01T23:59:59.000Z

166

Friction-Induced Fluid Heating in Nanoscale Helium Flows  

SciTech Connect (OSTI)

We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.

Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2010-05-21T23:59:59.000Z

167

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect (OSTI)

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

168

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

E-Print Network [OSTI]

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

Padilla, Yadira

2012-01-01T23:59:59.000Z

169

Low-GWP Refrigerants Research Project | Department of Energy  

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

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

170

Flow-induced vibration of component cooling water heat exchangers  

SciTech Connect (OSTI)

This paper presents an evaluation of flow-induced vibration problems of component cooling water heat exchangers in one of Taipower's nuclear power stations. Specifically, it describes flow-induced vibration phenomena, tests to identify the excitation mechanisms, measurement of response characteristics, analyses to predict tube response and wear, various design alterations, and modifications of the original design. Several unique features associated with the heat exchangers are demonstrated, including energy-trapping modes, existence of tube-support-plate (TSP)-inactive modes, and fluidelastic instability of TSP-active and -inactive modes. On the basis of this evaluation, the difficulties and future research needs for the evaluation of heat exchangers are identified. 11 refs., 19 figs., 3 tabs.

Yeh, Y.S.; Chen, S.S. (Taiwan Power Co., Taipei (Taiwan). Nuclear Engineering Dept.; Argonne National Lab., IL (USA))

1990-01-01T23:59:59.000Z

171

Evaporative system for water and beverage refrigeration in hot countries  

E-Print Network [OSTI]

Evaporative system for water and beverage refrigeration in hot countries A Saleh1 and MA Al-Nimr2 1 Abstract: The present study proposes an evaporative refrigerating system used to keep water or other are found to be consistent with the available literature data. Keywords: evaporative refrigeration, heat

172

On flow and supply temperature control in district heating systems  

Science Journals Connector (OSTI)

This paper discusses how the control of the flow and the supply temperature in district heating systems can be optimized, utilizing stochastic modelling, prediction and control methods. The main objective is to reduce heat production costs and heat losses in the transmission and distribution net by minimizing the supply temperature at the district heating plant. This control strategy is reasonable, in particular, if the heat production takes place at a combined heat and power (CHP) plant. The control strategy is subject to some restrictions, e.g. that the total heat requirement for all consumers is supplied at any time, and each individual consumer is guaranteed some minimum supply temperature at any time. Another important restriction is that the variation in time of the supply temperature is kept as small as possible. This concept has been incorporated in the program package, PRESS, developed at the Technical University of Denmark. PRESS has been applied and tested, e.g. at Vestkraft in Esbjerg, Denmark, and significant saving potentials have been documented. PRESS is now distributed by the Danish District Heating Association.

Henrik Madsen; Ken Sejling; Henning T. Sgaard; Olafur P. Palsson

1994-01-01T23:59:59.000Z

173

The heating of the cooling flow (The feedback effervescent heating model)  

E-Print Network [OSTI]

The standard cooling flow model has predicted a large amount of cool gas in the clusters of galaxies. The failure of the Chandra and XXM-Newton telescopes to detect cooling gas (below 1-2 keV) in clusters of galaxies has suggested that some heating process must work to suppress the cooling. The most likely heating source is the heating by AGNs. There are many heating mechanisms, but we will adopt the effervescent heating model which is a result of the interaction of the bubbles inflated by AGN with the intra-cluster medium(ICM). Using the FLASH code, we have carried out time dependent simulations to investigate the effect of the heating on the suppression of the cooling in cooling flow clusters. We have found that the effervescent heating model can not balance the radiative cooling and it is an artificial model. Furthermore, the effervescent heating is a function of the ICM pressure gradient but the cooling is proportional to the gas density square and square root of the gas temperature.

Nasser Mohamed Ahmed

2007-10-10T23:59:59.000Z

174

Assessment of adsorber bed designs in waste-heat driven adsorption cooling systems for vehicle air conditioning and refrigeration  

E-Print Network [OSTI]

Assessment of adsorber bed designs in waste-heat driven adsorption cooling systems for vehicle air conditioning Finned tube adsorber bed Specific cooling power Adsorber bed to adsorbent mass ratio a b s t r a c t Adsorber bed design strongly affects the performance of waste-heat driven adsorption cooling systems (ACS

Bahrami, Majid

175

Estimates of heat flow from Cenozoic seafloor using global depth and age data  

E-Print Network [OSTI]

-independent estimate of the total heat output of Cenozoic seafloor is 18.6 to 20.5 TW, which leads to a global output: Oceanic heat flow; Global heat budget; Subsidence rate 1. Introduction The total heat output of the EarthEstimates of heat flow from Cenozoic seafloor using global depth and age data Meng Wei , David

Sandwell, David T.

176

Helium Refrigerator Liquid Nitrogen Pre-Cooler Component Parameter Sensitivity Analysis  

SciTech Connect (OSTI)

For helium refrigerators using liquid nitrogen (LN) pre-cooling it is not uncommon for the ambient helium refrigeration return stream(s) exiting the cold box to be significantly colder and for the cycle to use more nitrogen than estimated by the process studies. Often there is an emphasis on the length of 300 to 80-K helium-nitrogen heat exchangers to ensure the exiting nitrogen is as close to ambient as possible. However, it is really the size and flow distribution of the 300 to 80-K helium-helium heat exchangers which are the dominate influence of the nitrogen consumption. As such, an analysis was done to identify and quantify the sensitivity the key parameters in the refrigerator LN pre-cooler section affecting the LN consumption.

Peter Knudsen, Venkatarao Ganni

2010-04-01T23:59:59.000Z

177

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

178

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

179

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

180

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

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

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

E-Print Network [OSTI]

with total refrigerant charge of 950 grams (2. 1 lbs) (Tanaka et. al. 1982). Table 2. 1 shows the distribution of refrigerant during steady state heating and cooling operation. Table 2. 1: Refri erant Distribution at Stead State Location Hestin made... light, (2) keep the charge as low as possible, (3) stop refrigerant flow into the outdoor coil during off periods, and (4) protect the compressor from slugging liquid. The work of the previously mentioned investigators has shown that the degradation...

Payne, William Vance

2012-06-07T23:59:59.000Z

182

Experimental study of fluid flow and heat transfer in tortuous microchannels.  

E-Print Network [OSTI]

??Tortuous microchannels have attracted increasing interest due to great potential to enhance fluid mixing and heat transfer. While the fluid flow and heat transfer in (more)

Dai, Zhenhui

2014-01-01T23:59:59.000Z

183

Particle Heating by Alfvenic Turbulence in Hot Accretion Flows  

E-Print Network [OSTI]

Recent work on Alfvenic turbulence by Goldreich & Sridhar (1995; GS) suggests that the energy cascades almost entirely perpendicular to the local magnetic field. As a result, the cyclotron resonance is unimportant in dissipating the turbulent energy. Motivated by the GS cascade, we calculate the linear collisionless dissipation of Alfven waves with frequencies much less than the proton cyclotron frequency, but with perpendicular wavelengths of order the Larmor radius of thermal protons. In plasmas appropriate to hot accretion flows (proton temperature much greater than electron temperature) the dissipated Alfven wave energy primarily heats the protons. For a plasma with $\\beta \\lsim 5$, however, where $\\beta$ is the ratio of the gas pressure to the magnetic pressure, the MHD assumptions utilized in the GS analysis break down before most of the energy in Alfven waves is dissipated; how the cascade then proceeds is unclear. Hot accretion flows, such as advection dominated accretion flows (ADAFs), are expected to contain significant levels of MHD turbulence. This work suggests that, for $\\beta \\gsim 5$, the Alfvenic component of such turbulence primarily heats the protons. Significant proton heating is required for the viability of ADAF models. We contrast our results on particle heating in ADAFs with recent work by Bisnovatyi-Kogan & Lovelace (1997).

Eliot Quataert

1997-10-13T23:59:59.000Z

184

Heat Transfer Reduction Across the Walls of Refrigerated Van Trailers by the Application of Phase Change Material  

E-Print Network [OSTI]

. The technology was tested in similar days in terms of temperature and solar insolation. The relevant variables that were monitored were the heat flux across the walls of the simulators and temperatures, including surface and indoor air temperatures. Other...

Ahmed, Mashud

2009-03-13T23:59:59.000Z

185

Thermodynamic Evaluation of Low-Global-Warming-Potential Refrigerants...  

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

Impact This will provide the heating, venting, air conditioning, and refrigeration (HVAC&R) industries and policymakers with definitive information regarding the available...

186

Improving Industrial Refrigeration System Efficiency - Actual Applications  

E-Print Network [OSTI]

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...

White, T. L.

1980-01-01T23:59:59.000Z

187

Momentum rate probe for use with two-phase flows S. G. Bush,a)  

E-Print Network [OSTI]

of flows including nuclear reactor coolant streams, refrigerants in heating-ventilating air flow rates of these flows span a wide range of values, from those in nuclear power plant cooling systems, through supercritical diesel fuel injection, heating-ventilating and air-conditioning HVAC

Panchagnula, Mahesh

188

Flow and heat transfer around a linear array of spheres  

SciTech Connect (OSTI)

Laminar fluid flow and forced convection heat transfer over equally space linear arrays of spheres are analyzed using the finite element package FIDAP. For the arrays, sphere spacings of 1.5, 2, and 3 diameters are examined at Reynolds numbers of 40, 80, and 120 and Prandtl numbers ranging from 0.73 to 7.3. Average Nusselt numbers and drag coefficient data for a linear array of eight spheres (as an approximation to the developing region) and a single sphere with periodic boundary conditions (as an approximation to fully developed flow) are presented and correlated.

Lloyd, B. (Marathon Oil Co., Shreveport, LA (United States)); Boehn, R. (Univ. of Nevada, Las Vegas, NV (United States). Mechanical Engineering Dept.)

1994-08-01T23:59:59.000Z

189

The regional geothermal heat flow regime of the north-central Gulf of Mexico continental slope.  

E-Print Network [OSTI]

??Eighty-eight oil and gas wells located in the Texas-Louisiana continental slope were analyzed to obtain heat flow and geothermal gradient values. Present-day geothermal heat flow (more)

Jones, Michael S

2003-01-01T23:59:59.000Z

190

A visualization comparison of convective flow boiling heat transfer augmentation devices  

E-Print Network [OSTI]

The qualitative effects of inset-table heat transfer phics. augmentation devices on vertical in-tube convective flow boiling flow regimes, transition mechanisms, and heat transfer are presented in this study. Three twisted tapes with twist ratios...

Lundy, Brian Franklin

2012-06-07T23:59:59.000Z

191

A numerica1 study of fluid flow and heat transfer in different microchannel heat sinks for electronic chip cooling  

Science Journals Connector (OSTI)

Four different microchannel heat sinks are designed to study the effects of structures in microchannel heat sinks for electronic chips cooling. Based on the theoretic analysis and numerical computation of flow...

Shanglong Xu; Guangxin Hu; Jie Qin

2012-04-01T23:59:59.000Z

192

Melting heat transfer effects on stagnation point flow of micropolar fluid saturated in porous medium with internal heat generation (absorption)  

Science Journals Connector (OSTI)

The effect of melting heat transfer on the two dimensional boundary layer flow of a micropolar fluid near a stagnation point embedded in a porous medium in the presence of internal heat generation/absorption is i...

M. A. A. Mahmoud; S. E. Waheed

2014-08-01T23:59:59.000Z

193

3D Numerical heat transfer and fluid flow analysis in plate-fin and tube heat exchangers with electrohydrodynamic enhancement  

Science Journals Connector (OSTI)

Three-dimensional laminar fluid flow and heat transfer over a four-row plate-fin and tube heat exchanger with electrohydrodynamic (EHD) wire electrodes...V E...=016kV) are investigated in detail...

Chia-Wen Lin; Jiin-Yuh Jang

2005-05-01T23:59:59.000Z

194

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

E-Print Network [OSTI]

; 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

195

Heat transfer to a fluid flowing in an annulus  

E-Print Network [OSTI]

. ii I ~ DIMENSIONS AND SYMBOLS o ~ ~ ~ . ~ ~ ~ ~ I II e INTRODUCTION AND THEORY ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 3 IXI e APPARATUS AND PROCEDURES ~ ~ e ~ ~ ~ ~ ~ ~ ~ ~ 7 XV o RESULTS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ 17 V, DXSCUSSION OF RESULTS... of times 0 Prandtl nnnber~ e~& dimensionless initial temperature oi' surfaoe and fluids% D equivalent diameter& Di g~ L Q - volume flow rate~ L3/T V~ mass velooity, FT/L3 6 mass floe rate~ FT/L IMTRODUCTIOR AND THEORY This thesis comprises heat tz...

Logan, Earl

2012-06-07T23:59:59.000Z

196

Heat transport by laminar boundary layer flow with polymers  

E-Print Network [OSTI]

Motivated by recent experimental observations, we consider a steady-state Prandtl-Blasius boundary layer flow with polymers above a slightly heated horizontal plate and study how the heat transport might be affected by the polymers. We discuss how a set of equations can be derived for the problem and how these equations can be solved numerically by an iterative scheme. By carrying out such a scheme, we find that the effect of the polymers is equivalent to producing a space-dependent effective viscosity that first increases from the zero-shear value at the plate then decreases rapidly back to the zero-shear value far from the plate. We further show that such an effective viscosity leads to an enhancement in the drag, which in turn leads to a reduction in heat transport.

Roberto Benzi; Emily S. C. Ching.; Vivien W. S. Chu

2011-04-23T23:59:59.000Z

197

NUMERICAL SIMULATIONS OF HEAT TRANSFER AND FLUID FLOW PROBLEMS USING AN  

E-Print Network [OSTI]

NUMERICAL SIMULATIONS OF HEAT TRANSFER AND FLUID FLOW PROBLEMS USING AN IMMERSED-BOUNDARY FINITE of the immersed boundary technique for simulating fluid flow and heat transfer problems over or inside complex. Several phenomenologically different fluid flow and heat transfer problems are simulated using

Pacheco, Jose Rafael

198

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based  

E-Print Network [OSTI]

Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also

Le Roy, Robert J.

199

FliHy experimental facilities for studying open channel turbulent flows and heat transfer  

E-Print Network [OSTI]

FliHy experimental facilities for studying open channel turbulent flows and heat transfer B. Freeze) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low supercritical flow regimes (Fr /1), in which the surface waves are amplified and heat transfer is enhanced due

Abdou, Mohamed

200

FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER  

E-Print Network [OSTI]

1 FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER B was constructed at UCLA to study open channel turbulent flow and heat transfer of low-thermal and low supercritical flow regimes (Fr>1), in which the surface waves are amplified and heat transfer is enhanced due

California at Los Angeles, University of

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

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a  

E-Print Network [OSTI]

Numerical simulations of heat transfer in plane channel flow Najla EL GHARBI 1, 3, a , Rafik ABSI 2 abenzaoui@gmail.com Keywords: turbulent flows, heat transfer, forced convection, low Reynolds number model data for Re = 150. Introduction Turbulent flow with heat transfer mechanism is of great importance from

Paris-Sud XI, Université de

202

Heat transfer in the flow of a viscoelastic fluid over a stretching sheet  

Science Journals Connector (OSTI)

The problem of heat transfer in the viscoelastic fluid flow over a stretching sheet is examined. ... such as the skin-friction coefficient and the heat transfer coefficient, are determined. It is found that the heat

P. Sam Lawrence; Dr. B. Nageswara Rao

1992-01-01T23:59:59.000Z

203

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

E-Print Network [OSTI]

for Simulating Fluid Flow and Heat Transfer in Unsaturatedcomplex multiphase fluid flow and heat-transfer processes.of the coupled fluid-flow and heat-transfer processes has

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

2005-01-01T23:59:59.000Z

204

Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with  

E-Print Network [OSTI]

Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur

Paris-Sud XI, Université de

205

ARTI refrigerant database  

SciTech Connect (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

206

Elastic Metal Alloy Refrigerants: Thermoelastic Cooling  

SciTech Connect (OSTI)

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 materialan elastic shape memory metal alloyas 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.

None

2010-10-01T23:59:59.000Z

207

Superinsulation in refrigerators and freezers  

SciTech Connect (OSTI)

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

208

A general heat transfer correlation for non-boiling gasliquid flow with different flow patterns  

E-Print Network [OSTI]

, such as oil wells and pipelines, solar collectors, chemical reactors, and nuclear reactors, and its in horizontal pipes Jae-yong Kim, Afshin J. Ghajar * School of Mechanical and Aerospace Engineering, Oklahoma patterns in horizontal pipes is proposed. In order to overcome the effect of flow pattern on heat transfer

Ghajar, Afshin J.

209

Convective flow and heat transfer of a viscous heat generating fluid in the presence of a moving, infinite, vertical, porous plate  

Science Journals Connector (OSTI)

The analysis of convective flow and heat transfer of a viscous heat generating fluid past a uniformly moving, infinite, vertical, ... of the plate-motion and the presence of heat generation/absorption on the flow...

K. Vajravelu

1978-09-01T23:59:59.000Z

210

Dynamic simulation of a reverse Brayton refrigerator  

SciTech Connect (OSTI)

A test refrigerator based on the modified Reverse Brayton cycle has been developed in the Chinese Academy of Sciences recently. To study the behaviors of this test refrigerator, a dynamic simulation has been carried out. The numerical model comprises the typical components of the test refrigerator: compressor, valves, heat exchangers, expander and heater. This simulator is based on the oriented-object approach and each component is represented by a set of differential and algebraic equations. The control system of the test refrigerator is also simulated, which can be used to optimize the control strategies. This paper describes all the models and shows the simulation results. Comparisons between simulation results and experimental data are also presented. Experimental validation on the test refrigerator gives satisfactory results.

Peng, N.; Xiong, L. Y.; Dong, B.; Liu, L. Q. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 (China); Lei, L. L.; Tang, J. C. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 China and Graduate University of Chinese Academy of Sciences, Beijing, 100190 (China)

2014-01-29T23:59:59.000Z

211

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

E-Print Network [OSTI]

, and pressure drop of R-123 over a bank of shrouded micro pin fins 243 lm long with hydraulic diameter of 99.5 lm. Heat transfer coefficients and Nusselt numbers have been obtained over effective heat fluxes studied in the context of turbine blade cooling. Nusselt number and friction factor correlations

Peles, Yoav

212

Combined Brayton-JT cycles with refrigerants for natural gas liquefaction  

Science Journals Connector (OSTI)

Thermodynamic cycles for natural gas liquefaction with single-component refrigerants are investigated under a governmental project in Korea aiming at new processes to meet the requirements on high efficiency large capacity and simple equipment. Based upon the optimization theory recently published by the present authors it is proposed to replace the methane-JT cycle in conventional cascade process with a nitrogen-Brayton cycle. A variety of systems to combine nitrogen-Brayton ethane-JT and propane-JT cycles are simulated with Aspen HYSYS and quantitatively compared in terms of thermodynamic efficiency flow rate of refrigerants and estimated size of heat exchangers. A specific Brayton-JT cycle is suggested with detailed thermodynamic data for further process development. The suggested cycle is expected to be more efficient and simpler than the existing cascade process while still taking advantage of easy and robust operation with single-component refrigerants.

Ho-Myung Chang; Jae Hoon Park; Sanggyu Lee; Kun Hyung Choe

2012-01-01T23:59:59.000Z

213

Modeling supermarket refrigeration energy use and demand  

SciTech Connect (OSTI)

A computer model has been developed that can predict the performance of supermarket refrigeration equipment to within 3% of field test measurements. The Supermarket Refrigeration Energy Use and Demand Model has been used to simulate currently available refrigerants R-12, R-502 and R-22, and is being further developed to address alternative refrigerants. This paper reports that the model is expected to be important in the design, selection and operation of cost-effective, high-efficiency refrigeration systems. It can profile the operation and performance of different types of compressors, condensors, refrigerants and display cases. It can also simulate the effects of store humidity and temperature on display cases; the efficiency of various floating head pressure setpoints, defrost alternatives and subcooling methods; the efficiency and amount of heat reclaim from refrigeration systems; and the influence of other variables such as store lighting and building design. It can also be used to evaluate operational strategies such as variable-speed drive or cylinder unloading for capacity control. Development of the model began in 1986 as part of a major effort, sponsored by the U.S. electric utility industry, to evaluate energy performance of then conventional single compressor and state-of-the-art multiplex refrigeration systems, and to characterize the contribution of a variety of technology enhancement features on system energy use and demand.

Blatt, M.H.; Khattar, M.K. (Electric Power Research Inst., Palo Alto, CA (US)); Walker, D.H. (Foster Miller Inc., Waltham, MA (US))

1991-07-01T23:59:59.000Z

214

Lattice Boltzmann method for rarefied channel flows with heat transfer  

Science Journals Connector (OSTI)

Abstract A thermal lattice Boltzmann method (TLBM) is presented for the analysis of fluid flow and heat transfer in two-dimensional channels with non-continuum effects. The relaxation times ( ? f , ? g ) are linked to the Knudsen number which accounts for the rarefaction that can be present at micro geometries or at low density conditions. The TLBM used here employs inlet/outlet boundary conditions to generate a forced convection problem where the calculation of equilibrium distributions at the wall surfaces are modified to incorporate the velocity slip and temperature jump conditions. Numerical simulations are obtained for thermal micro-Couette and thermal micro-Poiseuille channel flows and the effect of the Knudsen number on the velocity and temperature profile is investigated.

Seckin Gokaltun; George S. Dulikravich

2014-01-01T23:59:59.000Z

215

Numerical heat conduction in hydrodynamical models of colliding hypersonic flows  

E-Print Network [OSTI]

Hydrodynamical models of colliding hypersonic flows are presented which explore the dependence of the resulting dynamics and the characteristics of the derived X-ray emission on numerical conduction and viscosity. For the purpose of our investigation we present models of colliding flow with plane-parallel and cylindrical divergence. Numerical conduction causes erroneous heating of gas across the contact discontinuity which has implications for the rate at which the gas cools. We find that the dynamics of the shocked gas and the resulting X-ray emission are strongly dependent on the contrast in the density and temperature either side of the contact discontinuity, these effects being strongest where the postshock gas of one flow behaves quasi-adiabatically while the postshock gas of the other flow is strongly radiative. Introducing additional numerical viscosity into the simulations has the effect of damping the growth of instabilities, which in some cases act to increase the volume of shocked gas and can re-he...

Parkin, E R

2010-01-01T23:59:59.000Z

216

12.11.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/32 4. Refrigeration process comparison;  

E-Print Network [OSTI]

Engineering Laboratory / Värme- och strömningsteknik tel. 3223 ; ron.zevenhoven@abo.fi Kylteknik ("KYL") Refrigeration course # 424503.0 v. 2014 ?A 424503 Refrigeration / Kylteknik 12.11.2014?bo Akademi Univ - Thermal voltage part for T-E) see ---- boundaries in the figures below The energy input occurs at the point where

Zevenhoven, Ron

217

Paper No. 206 IIR Gustav Lorentzen Conference on Natural Refrigerants, Delft, The Netherlands, 2012  

E-Print Network [OSTI]

outside the buildings for devices having the refrigerant charge of small heat pumps for space heatingPaper No. 206 10th IIR Gustav Lorentzen Conference on Natural Refrigerants, Delft, The Netherlands by subcooling of the refrigerant in the cold water tank (not used for cooling during winter). The water tank

Paris-Sud XI, Université de

218

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

219

Proceedings: commercial refrigeration research workshop. Summary  

SciTech Connect (OSTI)

The purpose of this workshop was to identify the state-of-the-art and determine research needs for improving energy use and demand in commercial refrigeration applications. Workshop attendees included research and development, technical operations and marketing people from manufacturers of supermarket refrigeration, space conditioning, and energy management systems equipment, and from supermarket chains and electric utilities. Presentations were given on best current practice and research needs from the perspective of each of these industry segments. Working groups identified ten important research, development and equipment demonstration projects to improve the efficiency of refrigerating equipment, heating, ventilating and air-conditioning (HVAC) equipment, and other energy-using systems in supermarkets.

Blatt, M.H.

1984-10-01T23:59:59.000Z

220

A FIVE-WATTS G-M/J-T REFRIGERATOR FOR LHE TARGET AT BNL.  

SciTech Connect (OSTI)

A five-watts G-M/J-T refrigerator was built and installed for the high-energy physics research at Brookhaven National Laboratory in 2001. A liquid helium target of 8.25 liters was required for an experiment in the proton beam line at the Alternating Gradient Synchrotron (AGS) of BNL. The large radiation heat load towards the target requires a five-watts refrigerator at 4.2 K to support a liquid helium flask of 0.2 meter in diameter and 0.3 meter in length which is made of Mylar film of 0.35 mm in thickness. The liquid helium flask is thermally exposed to the vacuum windows that are also made of 0.35 mm thickness Mylar film at room temperature. The refrigerator uses a two-stage Gifford-McMahon cryocooler for precooling the Joule-Thomson circuit that consists of five Linde-type heat exchangers. A mass flow rate of 0.8 {approx} 1.0 grams per second at 17.7 atm is applied to the refrigerator cold box. The two-phase helium flows between the liquid target and liquid/gas separator by means of thermosyphon. The paper presents the system design as well as the test results including the control of thermal oscillation.

JIA,L.X.; WANG,L.; ADDESSI,L.; MIGLIONICO,G.; MARTIN,D.; LESKOWICZ,J.; MCNEILL,M.; YATAURO,B.; TALLERICO,T.

2001-07-16T23:59:59.000Z

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

An experimental study on new egg-crate type evaporators in domestic refrigerators and freezers  

SciTech Connect (OSTI)

This paper presents experimental results of the heat transfer performance of new egg-crate type evaporators that are becoming popular in vapor compression cycle-based modern refrigerators and freezers. These forced flow, multiple finned evaporators are preferred in the local industry over the older roll-bonded designs due to efficiency and cost considerations. Extensive testing was done, and experimental data were gathered on evaporators of three different sizes at three airflow rates using a closed-loop test rig built for the purpose. This has led to the development of a novel approach of measuring low air velocities as encountered in domestic refrigerators. A correlation has been developed for the heat transfer performance of these evaporators following the j-Colburn factor analysis. The correlation relates the j-Colburn factor, a nondimensional heat transfer grouping of the Nusselt number, Reynolds number, and Prandtl number to the Reynolds number and finning factor.

Bansal, P.K. [Univ. of Auckland (New Zealand). Dept. of Mechanical Engineering; Neuren, O.S. van [OPUS International Consultants, Ltd., Auckland (New Zealand)

1998-12-31T23:59:59.000Z

222

Review of fluid flow and convective heat transfer within rotating disk cavities  

E-Print Network [OSTI]

Review of fluid flow and convective heat transfer within rotating disk cavities with impinging jet * Corresponding author : souad.harmand@univ-valenciennes.fr Abstract Fluid flow and convective heat transfer, are treated in details in this review. The review focuses on convective heat transfer in predominantly outward

Boyer, Edmond

223

Review of fluid flow and convective heat transfer within rotating disk cavities  

E-Print Network [OSTI]

1 Review of fluid flow and convective heat transfer within rotating disk cavities with impinging axial direction #12;5 Introduction Fluid flow and convective heat transfer in rotor-stator configuration heat transfer in rotor-stator configurations, which are of great importance in different engineering

Paris-Sud XI, Université de

224

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system  

E-Print Network [OSTI]

Numerical modeling of fluid flow and heat transfer in a narrow Taylor-Couette-Poiseuille system S [1, 2] widely validated in various rotor-stator cavities with throughflow [3­5] and heat transfer [6: RANS modeling, Reynolds Stress Model, Taylor-Couette-Poiseuille flow, turbulence, heat transfer. hal

Paris-Sud XI, Université de

225

The effects of topology upon fluid-flow and heat-transfer within cellular copper structures  

E-Print Network [OSTI]

The effects of topology upon fluid-flow and heat-transfer within cellular copper structures J. Tian February 2004 Available online 20 March 2004 Abstract The fluid-flow and heat-transfer features of cellular and packed beds, but also a function of orientation (open area ratio). The overall heat transfer depends

Wadley, Haydn

226

The effects of topology upon fluid-flow and heat-transfer within cellular copper structures  

E-Print Network [OSTI]

1 The effects of topology upon fluid-flow and heat-transfer within cellular copper structures J The fluid-flow and heat-transfer features of copper cellular metal structures made by the transient liquid media. The experimental results for pressure drop and heat transfer were expressed on the basis

Wadley, Haydn

227

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation  

E-Print Network [OSTI]

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tube­Nusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem

Wei, Dongming

228

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow  

E-Print Network [OSTI]

Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT

Kostic, Milivoje M.

229

Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar  

E-Print Network [OSTI]

Flow Boiling Heat Transfer Coefficient In Minichannels ­ Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found

Kandlikar, Satish

230

Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law  

E-Print Network [OSTI]

Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1

Boyer, Edmond

231

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions  

E-Print Network [OSTI]

Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions by Carl, Measurements of Film Flow Rate in Heated Tubes with Various Axial Power Distributions KTH Nuclear Reactor power is limited by a phenomenon called critical heat flux (CHF). It appears as a sudden detoriation

Haviland, David

232

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

233

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

234

Next Generation Low-Global Warming Potential Refrigerants R&D...  

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

accelerate the transition to low-GWP refrigerants across the entire heating, ventilation, air-conditioning and refrigeration (HVAC&R) industry. The schedule of R&D activities...

235

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

E-Print Network [OSTI]

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...

Zheng, A.; Gu, J.

2006-01-01T23:59:59.000Z

236

Save with Hybrid Refrigeration  

E-Print Network [OSTI]

SAVE WITH HYBRID REFRIGERATION Cheng-Wen (Wayne) Chung, P.E. Fluor Engineers, Inc. Irvine, California ABSTRACT Two level demand makes it possible to use two systems for refrigeration and save energy and money. An example of this type... of refrigeration, consisting of an ammonia absorption refrigeration (AAR) unit and a mechanical compression refrigera tion (MCR) unit, is presented in this article. This paper will briefly describe process configur ation, advantages and utility consumption...

Chung, C. W.

237

Refrigerants in Transition  

E-Print Network [OSTI]

component of ternary blends and as a blowing agent. Further testing is ongoing to determine its performance characteristics. Since CFC-114 chillers constitute an estimated 1% of the more than 80,000 centrifugal chillers, testing has not been a high..., commercial refrigerators, ice makers, etc. Some commercial chillers. Some commercial refrigeration. Marine refrigeration, stationery chillers, ternary blends, blowing agents. 51 RESULTS OF TESTING The testing programs undertaken by the refrigerant...

Stouppe, D. E.

238

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

E-Print Network [OSTI]

. . Heat transfer and Flutd flow results ? Counter flow . 32 64 CONCLUSIONS . 101 REFERENCES . 104 APPENDIX A. APPENDIX B APPENDIX C LIST OF FIGURES FIGURE 1 Detailed Schematic of the Test Section with the Flow Loop for 81. 27cm Inner pipe... with Parallel Flow. . 2 Schematic Diagram showing the arrangement of the mner pipes with different diameters with the copper segments. 3 Schematic of the test section showmg the two different flow arrangements (Parallel Flow and Counter Flow) . Page 12 14...

Mhetras, Shantanu Prakash

2012-06-07T23:59:59.000Z

239

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

E-Print Network [OSTI]

development of fluid flow and heat transfer models at otherTOUGH2 code [22]. Fluid flow and heat-transfer processes inand heat transfer through fractured rock is based on the DKM method. This approach considers global fluid and

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

2006-01-01T23:59:59.000Z

240

APPLIANCE EFFICIENCY REGULATIONS FOR REFRIGERATORS AND FREEZERS  

E-Print Network [OSTI]

mobile equipment. (c) Central air conditioning heat pumps, regardless of capacity, except that requirements for central air conditioning heat pumps with cooling capacity of 135,000 Btu per hour or more#12;#12;APPLIANCE EFFICIENCY REGULATIONS FOR REFRIGERATORS AND FREEZERS ROOM AIR CONDITIONERS

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

2014-09-18 Issuance: Energy Conservation Standard for Alternative Efficiency Determination Methods, Basic Model Definition, and Compliance for Commercial HVAC, Refrigeration, and Water Heating Equipment; Supplemental Notice of Proposed Rulemaking  

Broader source: Energy.gov [DOE]

This document is a pre-publication Federal Register supplemental notice of proposed rulemaking regarding energy conservation standards for alternative efficiency determination methods, basic model definition, and compliance for commercial HVAC, Refrigeration, and Water Heating Equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on September 18, 2014. Though it is not intended or expected, should any discrepancy occur between the document posted here and the document published in the Federal Register, the Federal Register publication controls. This document is being made available through the Internet solely as a means to facilitate the public's access to this document.

242

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.

243

Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer, Longer-lasting Batteries  

Broader source: Energy.gov [DOE]

Partnered with NETZSCH, the National Renewable Energy Laboratory (NREL) developed an Isothermal Battery Calorimeter (IBC) used to quantify heat flow in battery cells and modules.

244

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations  

E-Print Network [OSTI]

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations J 2004) An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation

Brenner, Donald W.

245

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

246

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

247

Heat transfer in the nonisothermal flow of an anomalously viscous fluid in a helical duct  

Science Journals Connector (OSTI)

The problem of heat transfer in the initial section of a helical ... with a steady flow of an anomalously viscous fluid is solved numerically.

A. I. Mumladze; Yu. G. Nazmeev; O. V. Maminov

1982-08-01T23:59:59.000Z

248

Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU)  

Broader source: Energy.gov [DOE]

Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU) presentation at the April 2013 peer review meeting held in Denver, Colorado.

249

FRACSTIM/I: A Fully Coupled Fluid Flow/Heat Transport and Geomechanica...  

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

FRACSTIMI: A Fully Coupled Fluid FlowHeat Transport and Geomechanical DeformationFracture Generation Simulator aka FALCON: Fracturing and Liquid CONservation Robert K....

250

Heat and mass transfer on MHD heat generating flow through a porous medium in a rotating fluid  

Science Journals Connector (OSTI)

The problem of the free-convection flow of a viscous heat generating fluid through porous media in a rotating frame of reference is considered for the case when a strong magnetic field is imposed in a directio...

P. C. Ram

251

Experimental Study on Heat Transfer of Single-Phase Flow and Boiling Two-Phase Flow in Vertical Narrow Annuli  

SciTech Connect (OSTI)

Water single-phase and nucleate boiling heat transfer were experimentally investigated in vertical annuli with narrow gaps. The experimental data about water single-phase flow and boiling two-phase flow heat transfer in narrow annular channel were accumulated by two test sections with the narrow gaps of 1.0 mm and 1.5 mm. Empirical correlations to predict the heat transfer of the single-phase flow and boiling two-phase flow in the narrow annular channel were obtained, which were arranged in the forms of the Dittus-Boelter for heat transfer coefficients in a single-phase flow and the Jens-Lottes formula for a boiling two-phase flow in normal tubes, respectively. The mechanism of the difference between the normal channel and narrow annular channel were also explored. From experimental results, it was found that the turbulent heat transfer coefficients in narrow gaps are nearly the same to the normal channel in the experimental range, and the transition Reynolds number from a laminar flow to a turbulent flow in narrow annuli was much lower than that in normal channel, whereas the boiling heat transfer in narrow annular gap was greatly enhanced compared with the normal channel. (authors)

Suizheng Qiu; Guanghui Su; Dounan Jia [Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, Shaanxi, 710049 (China); Minoru Takahashi [Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152 (Japan)

2002-07-01T23:59:59.000Z

252

M . B a h r a m i ENSC 388 Experiment 2: Vapor Compression Refrigeration Cycle ENSC 388: Engineering Thermodynamics and Heat Transfer  

E-Print Network [OSTI]

Determining the coefficient of performance of a vapour compression refrigeration cycle. Apparatus Figure 1, a condenser, an evaporator and an expansion valve. The compressor unit shown in Fig. 2 comprises the liquid to vapor. The system has an expansion valve which is a float valve. Schematic of the expansion

Bahrami, Majid

253

Optimal performance of endoreversible quantum refrigerators  

E-Print Network [OSTI]

The derivation of general performance benchmarks is important in the design of highly optimized heat engines and refrigerators. To obtain them, one may model phenomenologically the leading sources of irreversibility ending up with results which are model-independent, but limited in scope. Alternatively, one can take a simple physical system realizing a thermodynamic cycle and assess its optimal operation from a complete microscopic description. We follow this approach in order to derive the coefficient of performance at maximum cooling rate for \\textit{any} endoreversible quantum refrigerator. At striking variance with the \\textit{universality} of the optimal efficiency of heat engines, we find that the cooling performance at maximum power is crucially determined by the details of the specific system-bath interaction mechanism. A closed analytical benchmark is found for endoreversible refrigerators weakly coupled to unstructured bosonic heat baths: an ubiquitous case study in quantum thermodynamics.

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

2014-11-24T23:59:59.000Z

254

Heat and Mass Transfer in the MHD Flow of a Visco-elastic Fluid in a Rotating Porous Channel with Radiative Heat  

Science Journals Connector (OSTI)

This paper deals with heat and mass transfer in the magnetohydrodynamic flow of a visco-elastic fluid in a rotating porous channel with radiative heat. The flow phenomenon has been characterized by the fluid para...

M. Jena; M. Goswami; S. Biswal

2014-12-01T23:59:59.000Z

255

Flow and heat transfer in porous micro heat sink for thermal management of high power LEDs  

Science Journals Connector (OSTI)

A novel porous micro heat sink system is presented for thermal management of high power LEDs, which has high heat transport capability. The operational principle and heat transfer characteristics of porous micro heat sink are analyzed. Numerical model ... Keywords: Heat dissipation, High heat flux, High power LEDs, Porous media, Porous micro heat sink

Z. M. Wan; J. Liu; K. L. Su; X. H. Hu; S. S. M

2011-05-01T23:59:59.000Z

256

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

E-Print Network [OSTI]

+ moisture a_Falls.jpg For the range -10 ~ +50°C, dry air can be treated as an ideal gas with c i 1 005 kJ/(kg· K) _Mist-Niagara cp,air 1.005 kJ/(kg K) The saturation pressure of water at 50°C is 12.3 k.3 kJ/kg c t 1.82 kJ/(kg· K) Picture:http:// 8.11.2012 ?bo Akademi Univ - Thermal and Flow

Zevenhoven, Ron

257

1.12.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/24 8. Heat pumps, heat pipes,  

E-Print Network [OSTI]

pumps, heat pipes, cold thermal energy storage Ron Zevenhoven ?bo Akademi University Thermal and Flow for heating is referred to as a heat pump (mostly based on a vapour-compression cycle) Heat pumps make use electricity!) for heating and air conditioning purposes Heat pumps became popular in the 1970s

Zevenhoven, Ron

258

Characteristics of Fluid flow and heat transfer in Shellside of Heat Exchangers with Longitudinal Flow of Shellside Fluid with Different Supporting structures  

Science Journals Connector (OSTI)

In the paper, a simplified numerical model-the periodic unit duct model was presented for the numerical simulation of shellside characteristics in heat exchanger with longitudinal flow of shellside fluid, and its...

Yongqing Wang; Qiwu Dong; Minshan Liu

2007-01-01T23:59:59.000Z

259

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

260

Implications of Heat Flow Studies for Geothermal Energy Prospects  

Science Journals Connector (OSTI)

There is a close interrelation between the phenomena of heat generation, storage of heat, transport of heat and the temperature field in the crust. For evaluating the geothermal energy potential of a given area t...

O. Kappelmeyer

1979-01-01T23:59:59.000Z

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

Monitoring refrigeration energy useage.  

SciTech Connect (OSTI)

Refrigerators use more energy than any other kitchen appliance -- an unsurprising fact considering that refrigerators operate 24 hours a day, 365 days a year to keep food at a safe temperature. In many low-income households, refrigerators eat up more than half the electricity consumed in one year. And if the refrigerator in a family's home is functioning poorly, the cost to the consumer can be enormous. Discovering whether an existing refrigerator is operating inefficiently enough to warrant replacing it is an extremely difficult task for a resident who sees only a monthly electric bill. Only by knowing the approximate usage of the existing unit can anyone tell whether it would pay to buy a new, energy-efficient refrigerator. The savings from replacing older refrigerators can be substantial, and collecting the data needed to determine when refrigerators should be replaced is easier and less costly than one might think. In both Chicago and New York City, replacing existing units cut refrigerator electricity usage by more than 50%. Monitoring to develop an average usage for the existing stock of refrigerators is a task that can be completed by maintenance staff in a reasonably short time -- and identifying poorly performing units that should be immediately replaced can take just two hours of monitoring.

Cavallo, J.; Mapp, J.; Energy Systems; Wisconsin Energy Bureau

2000-05-01T23:59:59.000Z

262

ARTI refrigerant database  

SciTech Connect (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. 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 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. Citations in this report are divided into the following topics: thermophysical properties; materials compatibility; lubricants and tribology; application data; safety; test and analysis methods; impacts; regulatory actions; substitute refrigerants; identification; absorption and adsorption; research programs; and miscellaneous documents. Information is also presented on ordering instructions for the computerized version.

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

1996-04-15T23:59:59.000Z

263

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

E-Print Network [OSTI]

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

Maruyama, Shigeo

264

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; Jos P. Palao; Daniel Alonso; Gerardo Adesso

2013-08-19T23:59:59.000Z

265

Mathematical circulation model for the blood-flow-heat-loss relationship in the rat tail  

Science Journals Connector (OSTI)

A mathematical model for the heat-loss-blood-flow relationship is developed for the rat tail. When supplied with experimental values of heat loss and blood flow, the model allows one to compute the distribution of flow in deep and cutaneous vessels as a function of body core and tail temperature and to determine the savings in heat loss that result from alterations in the pattern of circulation and from counter-current heat transfer. Blood flow in the cutaneous and deep lying veins of the tail is controlled by both central and local temperatures and increases fairly linearly with deep body temperature. However, the distribution of blood flow in the tail is controlled only by local tail temperature and is independent of deep body temperature. The change in venous distribution of flow has a great impact on the conservation of heat and can reduce the heat loss from the circulating blood by more than 50% when venous return is directed to deep lying veins. On the other hand, counter-current heat transfer is of only minor importance in the control of heat loss from the tail, resulting at most in a 10% saving of heat loss, and that only at the smallest rate of blood flow.

E R Raman; V J Vanhuyse; M F Roberts

1987-01-01T23:59:59.000Z

266

Regional variations of heat flow differences with depth in Alberta, Canada  

Science Journals Connector (OSTI)

......occupies the vast area between the Rocky Mountain Foothills in the SW...increases toward the west from the flat plains area to the foothills and the Rocky Mountains beyond. 3 Heat flow...features, and so the heat flow in ROCKY ' MOUNTAINS INTERIOR PLAINS......

J. A. Majorowicz; F. W. Jones; H.-L. Lam; A. M. Jessop

1985-05-01T23:59:59.000Z

267

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR  

E-Print Network [OSTI]

NUMERICAL STUDY OF FLUID FLOW AND HEAT TRANSFER OVER A SERIES OF IN-LINE NONCIRCULAR TUBES CONFINED, Texas A&M University, College Station, Texas, USA Two-dimensional steady developing fluid flow and heat-volume technique. Grid independence study was carried out by running the developed code for several different grid

Bahaidarah, Haitham M.

268

Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states  

E-Print Network [OSTI]

, refrigeration, HVAC, auto- mobile sector, space, nuclear and other emerging systems. While in many applications

Khandekar, Sameer

269

Taylor bubble-train flows and heat transfer in the context of Pulsating Balkrishna Mehta, Sameer Khandekar  

E-Print Network [OSTI]

Taylor bubble-train flows and heat transfer in the context of Pulsating Heat Pipes Balkrishna Mehta Nusselt number Heat transfer enhancement a b s t r a c t Understanding the performance of Pulsating Heat Pipes (PHPs) requires spatio-temporally coupled, flow and heat transfer information during the self

Khandekar, Sameer

270

Large Deviations in Stochastic Heat-Conduction Processes Provide a Gradient-Flow Structure for Heat Conduction  

E-Print Network [OSTI]

We consider three one-dimensional continuous-time Markov processes on a lattice, each of which models the conduction of heat: the family of Brownian Energy Processes with parameter $m$, a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti process. The hydrodynamic limit of each of these three processes is a parabolic equation, the linear heat equation in the case of the BEP$(m)$ and the KMP, and a nonlinear heat equation for the GBEP($a$). We prove the hydrodynamic limit rigorously for the BEP$(m)$, and give a formal derivation for the GBEP($a$). We then formally derive the pathwise large-deviation rate functional for the empirical measure of the three processes. These rate functionals imply gradient-flow structures for the limiting linear and nonlinear heat equations. We contrast these gradient-flow structures with those for processes describing the diffusion of mass, most importantly the class of Wasserstein gradient-flow systems. The linear and nonlinear heat-equation gradient-flow structures are each driven by entropy terms of the form $-\\log \\rho$; they involve dissipation or mobility terms of order $\\rho^2$ for the linear heat equation, and a nonlinear function of $\\rho$ for the nonlinear heat equation.

Mark A. Peletier; Frank Redig; Kiamars Vafayi

2014-03-19T23:59:59.000Z

271

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

272

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

273

Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement  

E-Print Network [OSTI]

Flow-induced deformation of thin structures coupled with convective heat transfer has potential applications in energy harvesting and is important for understanding functioning of several biological systems. We numerically demonstrate large-scale flow-induced deformation as an effective passive heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. In the present work, we validate convective heat transfer module of the in-house FSI solver against several benchmark examples of conduction and convective heat transfer including moving structure boundaries. The thermal augmentation is investigated as well as quantified for the flow-induced deformation of an elastic thin plate attached to lee side of a rigid cylinder in a heated channel laminar flow. We show that the wake vortices past the plate sweep higher sources of vorticity...

Soti, Atul Kumar; Sheridan, John

2015-01-01T23:59:59.000Z

274

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

275

Numerical investigation of flow structure and mixed convection heat transfer of impinging radial and axial jets  

SciTech Connect (OSTI)

Mixed convection flow fields and heat transfer of partially enclosed axial and radial laminar jets impinging on a heated flat plate have been investigated from the numerical solution of incompressible unsteady Navier-Stokes and energy equations with a Boussinesq approximation. For mixed convection flow at Re = 200, steady flow has not been observed for either the radial or the axial jet. For the smallest Grashof number (Gr = 10,000), periodic solutions have been obtained. With Gr = 40,000 nonsteady nonperiodic (chaotic) flow appears. Free convection may increase that heat transfer by more than 200%.

Potthast, F.; Laschefski, H.; Mitra, N.K. (Ruhr-Univ. Bochum (Germany). Inst. fuer Thermo- und Fluiddynamik); Biswas, G. (Indian Inst. of Tech., Kanpur (India). Dept. of Mechanical Engineering)

1994-08-01T23:59:59.000Z

276

Manufacture of refrigeration oils  

SciTech Connect (OSTI)

Lubricating oils suitable for use in refrigeration equipment in admixture with fluorinated hydrocarbon refrigerants are produced by solvent extraction of naphthenic lubricating oil base stocks, cooling the resulting extract mixture, optionally with the addition of a solvent modifier, to form a secondary raffinate and a secondary extract, and recovering a dewaxed oil fraction of lowered pour point from the secondary raffinate as a refrigeration oil product. The process of the invention obviates the need for a separate dewaxing operation, such as dewaxing with urea, as conventionally employed for the production of refrigeration oils.

Chesluk, R.P.; Platte, H.J.; Sequeira, A.J.

1981-12-08T23:59:59.000Z

277

EXPERIMENTAL INVESTIGATION OF TURBULENT HEAT TRANSFER OF HIGH PRANDTL NUMBER FLUID FLOW UNDER STRONG MAGNETIC FIELD  

E-Print Network [OSTI]

EXPERIMENTAL INVESTIGATION OF TURBULENT HEAT TRANSFER OF HIGH PRANDTL NUMBER FLUID FLOW UNDER to the heat transfer characteristic: Flibe is a high Prandtl number fluid. For high Prandtl number fluid, there is a severe limitation of temperature window due to its high melting point. The turbulent heat transfer is

Abdou, Mohamed

278

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow  

E-Print Network [OSTI]

Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

Boyer, Edmond

279

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,  

E-Print Network [OSTI]

Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

Kandlikar, Satish

280

Energy-efficiency directory of refrigerators and refrigerator-freezers  

SciTech Connect (OSTI)

Information is presented about the energy costs of operating refrigerators and refrigerator-freezers and includes the type of refrigerator or refrigerator-freezer, the fresh food volume, the freezer volume, the total volume, and the yearly energy cost. The directory lists all currently marketed electric refrigerators and refrigerator-freezers that have Energy Guide labels. The Federal Trade Commission requires manufacturers who distribute refrigerators and refrigerator-freezers to attach Energy Guide labels to appliances manufactured on or after May 19, 1980. The data have been measured by manufacturers and/or their agents according to US Government standard test procedures.

Statt, T.G.; Coggins, J.L.

1981-06-01T23:59:59.000Z

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.


281

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

282

HVAC Optimized Heat Exchangers Research Project | Department of Energy  

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

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

283

ARC-HEATED GAS FLOW EXPERIMENTS FOR HYPERSONIC PROPULSION  

E-Print Network [OSTI]

was extensively developed for the purpose of eventually performing experiments simulating scramjet engine flow

Texas at Arlington, University of

284

Innovative Method for Performance Inspections often save 20-30% through Optimization of Air-Conditioning and Refrigeration  

E-Print Network [OSTI]

of performance?. (Nordtest.) Esbo, Finland. 16. NT VVS 116, 1997. ?Refrigeration and heat pump equipment: Check-ups and performance data inferred from measurements under field conditions in the refrigerant system?. (Nordtest.) Esbo, Finland. ESL-IC-10...

Berglof, K.

2010-01-01T23:59:59.000Z

285

Analysis of cross-flow mixed convection with applications to building heat transfer  

SciTech Connect (OSTI)

A numerical simulation model has been developed for partial enclosure with restricted inlet and outlet simulating the building fluid flow and heat transfer scenario. Computed results are presented for a number of geometric configurations over a wide range of Reynolds and Rayleigh numbers and validated with available experimental data. The physical processes were modeled by solving equations for the conservation of mass, momentum, and energy with appropriate boundary conditions. The properties of the fluid were assumed to remain approximately constant over the range of operation and the buoyancy was incorporated using the Boussinesq approximation. The k-{var_epsilon} model was used for the simulation of turbulence. The computed results included the local velocity and temperature and the variation of local heat transfer coefficient along the heated side wall. Computed results showed excellent agreement with experimental data. The flow pattern within the enclosure was found to be quite complex in nature and consisted of a core flow due to forced convection near the central region of the enclosure and strong buoyancy induced flow near the heated side walls. It was found that as the flow rate through the enclosure increased, the enhancement of heat transfer above that for natural convection alone, also increased. The variation of the local heat transfer coefficient over the heated surface was found to be strongly affected by the recirculation of portions of the forced flow within the enclosure as well as the impingement to or separation of flow from the side walls in some regions.

Gao, S.; Rahman, M.M.

1999-07-01T23:59:59.000Z

286

ARTI Refrigerant Database  

SciTech Connect (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

287

Microsoft Word - PDFSelfHeatTPMFinal.doc  

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

Sample Self-Heating in the Portable Dilution Refrigerator Figure 1. Self-heating of a model sample in a dilution refrigerator. Sample temperature is plotted as a function of the...

288

Modelica-based modelling and simulation of dry-expansion shell-and-tube evaporators working with alternative refrigerant mixtures  

Science Journals Connector (OSTI)

A new methodology of intermediate complexity level is developed to model the dry-expansion shell and U-tube evaporators. The model has a reasonable level of accuracy and uses fundamental physical principles in a distributed parameters approach capable of detecting the complex circuit of the shell-side flow. This level of details is necessary to simulate accurately the zeotropic refrigerant mixtures evaporation. Using Modelica language gives a heat exchanger model with a generic flow arrangement. The model is experimentally validated using a standard shell-and-tube evaporator working with HFC-134a. Three distinct working fluids, pure HFC-134a, R-407C, and a specially selected glide matching refrigerant mixture are simulated in the same heat source duty with different shell-and-tube configurations. Three different gas superheat values are also taken into account. The total amount of irreversibility is considered by calculating the total exergy losses. It is concluded that the effect of the temperature profile of any refrigerant mixture can be substantial on the relative performance of a particular heat exchanger configuration compared to counter-flow configuration.

Khattar Assaf; Assaad Zoughaib; Denis Clodic

2011-01-01T23:59:59.000Z

289

Closed cycle liquid helium refrigerators  

Science Journals Connector (OSTI)

We have developed closed cycle liquid helium refrigerators using a Joule Thomson circuit precooled by commercially available two staged Gifford Mac Mahon cryocoolers. The Joule Thomson counterflow heat exchangers are modular and have been thermo-hydraulically characterized. Fully automatic cool down and operation are achieved by two pneumatically driven by pass and expansion valves. Several apparatus have been built or are under assembly with cooling power ranging from 100 mW up to 5 Watt, for temperature ranging from 2.8 K up to 4.5 K. A trouble free operation with several warm up and cool down cycles has been proven over 7000 hours.

G. Claudet; R. Lagnier; A. Ravex

1992-01-01T23:59:59.000Z

290

ECI International Conference on Heat Transfer and Fluid Flow in Microscale Whistler, 21-26 September 2008  

E-Print Network [OSTI]

ECI International Conference on Heat Transfer and Fluid Flow in Microscale Whistler, 21] studied convective heat transfer of slug flows in a macro-sized tube by using viscoelastic fluids-26 September 2008 NUMERICAL STUDY ON CONVECTIVE HEAT TRANSFER OF GAS-LIQUID SLUG FLOW IN A MICRO TUBE Qunwu He

Kasagi, Nobuhide

291

PHYSICAL REVIEW E 84, 048302 (2011) Reply to "Comment on `Heat transfer and fluid flow in microchannels and nanochannels  

E-Print Network [OSTI]

PHYSICAL REVIEW E 84, 048302 (2011) Reply to "Comment on `Heat transfer and fluid flow) model for high-Knudsen-number (Kn) flow and heat transfer, in the range of Kn 1. We present various studies employing the LBGK model for high-Kn flow and heat transfer simulations. It is concluded that

Luo, Li-Shi

292

Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems  

DOE Patents [OSTI]

Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

Meisner, Gregory P

2013-10-08T23:59:59.000Z

293

Mapping Geothermal Heat Flow and Existing Plants | Department...  

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

resources make up most of the current geothermal operating plants in the United States. Power generation comes from drawing heat from the fluid found naturally deep below the...

294

Development of a prototype optical refrigerator  

SciTech Connect (OSTI)

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The authors have carried out a range of tasks directed toward the construction and testing of a proof-of-principle optical refrigerator prototype. They procured and tested new cooling elements that are at the heart of an optical refrigerator. The cooling element absorbs pump radiation and then fluoresces with nearly unity quantum efficiency. They constructed and tested a cooling chamber with low thermal emissivity walls that reduces the parasitic heating.

Epstein, R.I.; Edwards, B.C.; Sigel, G.H.

1998-01-01T23:59:59.000Z

295

Numerical modeling of deep groundwater flow and heat transport in the Williston Basin  

SciTech Connect (OSTI)

A numerical modeling approach has been used to evaluate quantitatively the effects of fluid flow on contemporary heat flow in an intracratonic basin. The authors have selected the Williston basin for this hydrodynamic study because of the opportunity it presents to assess the relation of deep groundwater flow to basin geothermics and the associated features of diagenesis and petroleum accumulation. The finite element method is used to solve the coupled equations of fluid flow and heat transport in two-dimensional sections of the basin. Both the fluid- and heat-flow regime are assumed to be at steady state, and the fluid flow is driven primarily by the water-table relief which is taken to be a subdued replica of land-surface topography. Buoyancy forces may also affect flow through fluid density gradients created by temperature and salinity effects. Three southwest-northwest oriented sections across the basin were modeled using available and estimated parameter data. The predicted flow patterns are most strongly affected by the topography, but the Devonian salt unit and Cretaceous shale unit exert some control. Cross-formational flow is especially important near the downdip, solution edge of the salt beds. Flow rates rarely exceed 0.5 m/year in the deep-central part of the basin, yet there does exist a marked effect on heat flow, albeit subdued by the blanket effect of the low-permeability Cretaceous shales. The regional effect of the topography-driven flow system is reflected in present-day salinity patterns and heat-flow data.

Garven, G.; Vigrass, L.

1985-01-01T23:59:59.000Z

296

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

297

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

298

Local heat and mass transfer for gas-solid two phase flow in CFB  

Science Journals Connector (OSTI)

An experimental investigation on the flow characteristics and the local heat and mass transfer between coarse wet particles and hot gas in the circulating fluidized bed (CFB) has been performed. A two-thermocoupl...

Feng Lu; Ming-Heng Shi

1994-09-01T23:59:59.000Z

299

Heat transfer due to stagnation point flow of a non-Newtonian fluid  

Science Journals Connector (OSTI)

Heat transfer analysis for steady, laminar flow of an incompressible, homogeneous, non-Newtonian fluid of second grade at a stagnation point...K, of the fluid. The energy equation is discretized using central ......

V. K. Garg

1994-01-01T23:59:59.000Z

300

Heat-transfer mechanism in turbulent flow of fluid at supercritical pressures  

Science Journals Connector (OSTI)

A hypothetical physical model of the heat-transfer process accompanying a forced flow of liquid at supercritical pressures is proposed. This model accounts for the anomalous improvements and deteriorations in ...

Sh. G. Kaplan

1971-09-01T23:59:59.000Z

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

Second-order fluid flow past a stretching sheet with heat transfer  

Science Journals Connector (OSTI)

The heat transfer in the flow of a second-order fluid, obeying Coleman and Noll's constitutive equation...KC/v. The thermal boundary layer thickness decreases and the Nusselt numberNu x increases ...

N. M. Bujurke; S. N. Biradar; P. S. Hiremath

1987-07-01T23:59:59.000Z

302

Unsteady hydromagnetic free-convection flow with radiative heat transfer in a rotating fluid  

Science Journals Connector (OSTI)

We consider the buoyancy-induced flow of an electrically-conducting fluid with radiative heat transfer past a vertical flat plate of infinite ... vary with temperature, that is a compressible fluid. If the temper...

A. R. Bestman; S. K. Adjepong

303

Heat transfer in a radiating fluid with slug flow in a parallel-plate channel  

Science Journals Connector (OSTI)

As a step towards a better understanding of combined conduction, convection, and radiation, fully developed heat transfer in slug flow in a flat duct ... , nonblack, isothermal surfaces. The gray radiating fluid ...

R. Viskanta

1964-01-01T23:59:59.000Z

304

Heat transfer in an MHD channel flow with boundary conditions of the third kind  

Science Journals Connector (OSTI)

The heat transfer equation for a two-dimensional magnetohydrodynamic channel flow has been solved using boundary conditions of the third kind considering a discontinuity in the ambient temperature. The bound...

Sergio Cuevas; Eduardo Ramos

1991-01-01T23:59:59.000Z

305

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

E-Print Network [OSTI]

creating unique visual and quantitative data. These data were then analyzed using a resistance type heat transfer model and five different zero gravity flow regime maps. Results from this analysis included: (i) presenting zero gravity data that correlated...

Westheimer, David Thomas

2012-06-07T23:59:59.000Z

306

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

E-Print Network [OSTI]

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...

Chintada, Sailesh Raju

1998-01-01T23:59:59.000Z

307

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

Open Energy Info (EERE)

Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat Flow From Four New...

308

Influence of surface heating on the boundary layer stability of flows with favorable pressure gradients  

E-Print Network [OSTI]

INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABI E PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE August 1986 Major Subject: Aerospace Engineering INFLUENCE OF SURFACE HEATING ON THE BOUNDARY LAYER STABILITY OF FLOWS WITH FAVORABLE PRESSURE GRADIENTS A Thesis by DAVID BRIAN LANDRUM Approved as to style and content...

Landrum, David Brian

2012-06-07T23:59:59.000Z

309

Finite element analysis of conjugate heat transfer in axisymmetric pipe flows  

E-Print Network [OSTI]

FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MA STER... OF S CI EN CE August 1987 Major Subject: Mechanical Engineering FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Approved ss to style and content by: N. K. Anand (Chairman of Committee...

Fithen, Robert Miller

2012-06-07T23:59:59.000Z

310

Characteristics of fluid flow and heat transfer in a fluidized heat exchanger with circulating solid particles  

Science Journals Connector (OSTI)

The commercial viability of heat exchanger is mainly dependent on its long- ... loss and degrades the thermal performance of a heat exchanger. An experimental study was performed to investigate the characteristic...

Soo Whan Ahn; ByungChang Lee; WonCheol Kim; Myung- Whan Bae

2002-09-01T23:59:59.000Z

311

Numerical Analysis of Fluid Flow and Heat Transfer within Grooved Flat Mini Heat Pipes  

Science Journals Connector (OSTI)

A Theoretical study is carried out in order to verify the Mini Heat Pipe (MHP) concept for cooling high ... as an integrated part of a Flat Mini Heat Pipe (FMHP). Hence, a detailed ... with axial microchannels is...

Jed Mansouri; Samah Maalej; Mohamed Sassi

2013-01-01T23:59:59.000Z

312

Terrestrial Heat Flow and Heat Generation in South-west England  

Science Journals Connector (OSTI)

......g cm-3 and a heat generation contrast of 3.35 pW...batholith, assuming heat generation from the country rocks...that radioactive heat generation is not constant throughout...University of London Reactor Centre for providing...from radioactivity, Nuclear Geology, ed. H. Faul......

H. Y. Tammemagi; J. Wheildon

1974-07-01T23:59:59.000Z

313

Heat transfer and pressure drop for air flow through enhanced passages  

SciTech Connect (OSTI)

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

314

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

SciTech Connect (OSTI)

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

315

A Refined Model of Stationary Heat Transfer in Composite Bodies Reinforced with Pipes Containing a Heat-Transfer Fluid Moving in Laminar Flow Conditions  

Science Journals Connector (OSTI)

Equations describing the stationary heat conduction of composite bodies spatially reinforced with ... of smooth pipes, through which an incompressible heat-transfer fluid is pumped in laminar flow conditions, are...

A. P. Yankovskii

2014-03-01T23:59:59.000Z

316

Three-dimensional analysis of fluid flow and heat transfer in single- and two-layered micro-channel heat sinks  

Science Journals Connector (OSTI)

A three-dimensional numerical analysis of laminar fluid flow and conjugate heat transfer has been conducted for single- and two-layered micro-channel heat sinks. The validity of the numerical model ... power, the...

M. L.-J. Levac; H. M. Soliman; S. J. Ormiston

2011-11-01T23:59:59.000Z

317

Heat and mass transfer in a viscoelastic fluid flow over an accelerating surface with heat source/sink and viscous dissipation  

Science Journals Connector (OSTI)

...?In this paper we present a mathematical analysis of heat and mass transfer phenomena in a viscoelastic fluid flow over an accelerating stretching sheet in the presence of heat source/sink, viscous dissipatio...

R. M. Sonth; S. K. Khan; M. S. Abel; K. V. Prasad

2002-02-01T23:59:59.000Z

318

On Heating of Cluster Cooling Flows by Sound Waves  

E-Print Network [OSTI]

We investigate heating of the cool core of a galaxy cluster through the dissipation of sound waves excited by the activities of the central active galactic nucleus (AGN). Using a weak shock theory, we show that this heating mechanism alone cannot reproduce observed temperature and density profiles of a cluster, because the dissipation length of the waves is much smaller than the size of the core and thus the wave energy is not distributed to the whole core. However, we find that if it is combined with thermal conduction from the hot outer layer of the cluster, the wave heating can reproduce the observational results.

Yutaka Fujita; Takeru Ken Suzuki

2005-08-10T23:59:59.000Z

319

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

E-Print Network [OSTI]

. 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...

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

2006-01-01T23:59:59.000Z

320

BUBBLE CHARACTERISTICS AND CONVECTIVE EFFECTS IN THE FLOW BOILING HEAT TRANSFER OF BINARY MIXTURES  

E-Print Network [OSTI]

BUBBLE CHARACTERISTICS AND CONVECTIVE EFFECTS IN THE FLOW BOILING HEAT TRANSFER OF BINARY MIXTURES on the bubble growth and associated heat transfer phenomena. The present work focuses on obtaining the bubble. The bubble growth is observed using a high speed camera (1000 fps) under a magnification of 290X. The bubble

Kandlikar, Satish

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

A method to visualise near wall fluid flow patterns using locally resolved heat transfer experiments  

Science Journals Connector (OSTI)

Abstract The present study demonstrates an alternative approach for describing fluid flow characteristics very close to the wall, using locally resolved convective heat transfer experiments. Heat transfer coefficients on the base surface and around a surface mounted vortex generator of delta-wing shape design, are evaluated with the transient liquid crystal measurement technique and over a range of freestream velocities. Therefore, the local values of exponent m in the equation Nu x ? Re x m , which is directly linked to the structure of the boundary layer, can be determined over the complete heat transfer area. The local distributions of exponent m are then directly compared to the footprint of the flow obtained with typical oil and dye surface flow visualisation. The results indicate that a more appropriate interpretation of the flow structures very close to the wall is possible by analysing the spatial variation of exponent m, which approximates better the flow pattern compared to the heat transfer coefficients. As a result, fluid flow topologies can be directly evaluated from the heat transfer experiments since the distributions of oil-flow visualisation and exponent m are qualitatively similar.

Alexandros Terzis; Jens von Wolfersdorf; Bernhard Weigand; Peter Ott

2015-01-01T23:59:59.000Z

322

The Quantum Absorption Refrigerator Amikam Levy and Ronnie Kosloff  

E-Print Network [OSTI]

, 07.20.Pe,05.30.-d I. INTRODUCTION The adsorption chiller is a refrigerator which employs a heat source to replace mechanical work for driving a heat pump [1]. The first device was developed in 1850 c J h P Tc Th Tw - - - 0 FIG. 1: The quantum trickle: A quantum heat pump des- ignated

Kosloff, Ronnie

323

An analog analysis of transient heat flow in solids with temperature-dependent thermal properties  

E-Print Network [OSTI]

) used a nonlinear material known as Metrosil to simulate the nonlinear variations of thermal properties for combined conductive and radiant heat transfer. Since that time, Friedmann (8) has used nonlinear resistances in conjunction with an electronic... at end of this thesis. K = thermal conductivity of heat conducting media, and K and S are functions of the temperature t. Since the formation of these equations, solutions of transient heat flow problems involving materials in which the thermal...

Lee, Dwain Edward

2012-06-07T23:59:59.000Z

324

Cryogenic optical refrigeration.  

E-Print Network [OSTI]

??This thesis compiles recent achievements in optical refrigeration, cooling a 5 wt. % ytterbium doped yttrium lithium fluoride (Yb+3:YLF) crystal through anti-Stokes fluorescence to a (more)

Melgaard, Seth

2011-01-01T23:59:59.000Z

325

Heat transfer enhancement during condensation in smooth tubes with helical wire inserts .  

E-Print Network [OSTI]

??In the past two decades the refrigeration, air-conditioning and heat pump industries began the conversion from chlorofluorocarbon (CFC) refrigerants to hydrochlorofluorocarbons (HCFCs) and to natural (more)

Ji, Tianfu

2008-01-01T23:59:59.000Z

326

Multi-stage Cascaded Stirling Refrigerator  

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

Multi-stage Cascaded Stirling Refrigerator Multi-stage Cascaded Stirling Refrigerator Los Alamos National Laboratory (LANL) researchers have developed a multi-stage refrigerator,...

327

International Refrigeration: Order (2012-CE-1510) | Department...  

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

Refrigeration: Order (2012-CE-1510) July 20, 2012 DOE ordered International Refrigeration Products to pay an 8,000 civil penalty after finding International Refrigeration had...

328

Heat source/sink effects on non-Newtonian MHD fluid flow and heat transfer over a permeable stretching surface: Lie group analysis  

Science Journals Connector (OSTI)

An analysis is performed for flow and heat transfer of a non-Newtonian fluid known as Casson fluid over a permeable stretching surface through a...

M. N. Tufail; A. S. Butt; A. Ali

2014-01-01T23:59:59.000Z

329

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

330

Numerical Analysis of Heat Transfer and Fluid Characteristics of Flowing Liquid Nitrogen in HTS Cable  

Science Journals Connector (OSTI)

Abstract High-temperature superconducting (HTS) cable has heat intrusion from the termination including joule heat generation at the terminal joint and from the room temperature cable through the Cu current lead. According to the length of the HTS cable, this heat loss may become a considerable amount which cannot be ignored in the HTS cable system. In this study, referring to a high-voltage cable (HV cable) which was developed in M-PACC project, the effect of heat transfer at the interface between the terminal joint and LN2 in the terminal vessel (ho) on the temperature of the HTS cable were calculated and evaluated. The condition of flow in the terminal vessel was assumed to be natural convection, forced flow or static condition for evaluating this effect with various heat transfer condition. As a result, in the case of the natural convection, most of heats flow into the LN2 in the terminal vessel where the volumetric flow of the LN2 is large since ho becomes high. Accordingly, the temperature rise of the LN2 in the inner pipe of Cu former and the terminal vessel can be restricted. However, in the cases of the forced flow and the static condition, most of heats flow into the LN2 in the inner pipe where the volumetric flow of the LN2 is small since ho becomes small. Accordingly, the temperature rise of the LN2 in the inner pipe becomes high. This temperature rise of the LN2 in the inner pipe makes the temperature of the HTS conductor large resulting in remarkable increase of AC losses. Consequently, on the HV cable design, for restriction of the AC loss increase, it is expected that designing the HTS cable termination such as extending outer surface of the terminal joint for increasing of the heat inflow from the terminal joint to the LN2 in the vessel is effective.

O. Maruyama; T. Ohkuma; T. Izumi; Y. Shiohara

2014-01-01T23:59:59.000Z

331

ORIGINAL PAPER Flow Dynamics and Plasma Heating of Spheromaks in SSX  

E-Print Network [OSTI]

ORIGINAL PAPER Flow Dynamics and Plasma Heating of Spheromaks in SSX M. R. Brown ? C. D. Cothran ? from single dipole- trapped spheromaks and spheromak merging studies at SSX. Single spheromaks) copper flux conserver. Local spheromak flow is studied with two Mach probes (r1 £ qi, r2 qi) calibrated

Brown, Michael R.

332

ENERGY CONCENTRATION FOR 2-DIMENSIONAL RADIALLY SYMMETRIC EQUIVARIANT HARMONIC MAP HEAT FLOWS  

E-Print Network [OSTI]

flows. Adapting Struwe's energy method we first establish a finite bubble tree result with a discrete, energy method, energy quanta, bubble tree, bubbling off, single bubble, intersection-comparison. AMSENERGY CONCENTRATION FOR 2-DIMENSIONAL RADIALLY SYMMETRIC EQUIVARIANT HARMONIC MAP HEAT FLOWS

Hulshof, Joost

333

Scale effects on flow boiling heat transfer in microchannels: A fundamental perspective  

E-Print Network [OSTI]

pattern transitions and stability for flow boiling of water and FC-77 are evaluated. From the insight between heat transfer around a nucleating bubble in pool boiling and in the elongated bubble/slug flow on the high-speed visualization and localized thermal measurements made at the base of a nucleating bubble

Kandlikar, Satish

334

Modeling Supermarket Refrigeration Systems with EnergyPlus  

SciTech Connect (OSTI)

Supermarket refrigeration capabilities were first added to EnergyPlus in 2004. At that time, it was possible to model a direct expansion (DX) rack system with multiple refrigerated cases. The basic simulation software handles all the building energy uses, typically on a 5 to 10 minute time step throughout the period of interest. The original refrigeration module included the ability to model the sensible and latent interactions between the refrigerated cases and the building HVAC system, along with some basic heat recovery capabilities. Over the last few years, the refrigeration module has been expanded to handle more complex systems, such as secondary loops, shared condensers, cascade condensers, subcoolers, and walk-in coolers exchanging energy with multiple conditioned zones.

Stovall, Therese K [ORNL; Baxter, Van D [ORNL

2010-01-01T23:59:59.000Z

335

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

SciTech Connect (OSTI)

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

336

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

337

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

338

Development of a Water Based, Critical Flow, Non-Vapor Compression cooling Cycle  

SciTech Connect (OSTI)

Expansion of a high-pressure liquid refrigerant through the use of a thermostatic expansion valve or other device is commonplace in vapor-compression cycles to regulate the quality and flow rate of the refrigerant entering the evaporator. In vapor-compression systems, as the condensed refrigerant undergoes this expansion, its pressure and temperature drop, and part of the liquid evaporates. We (researchers at Kansas State University) are developing a cooling cycle that instead pumps a high-pressure refrigerant through a supersonic converging-diverging nozzle. As the liquid refrigerant passes through the nozzle, its velocity reaches supersonic (or critical-flow) conditions, substantially decreasing the refrigerants pressure. This sharp pressure change vaporizes some of the refrigerant and absorbs heat from the surrounding conditions during this phase change. Due to the design of the nozzle, a shockwave trips the supersonic two-phase refrigerant back to the starting conditions, condensing the remaining vapor. The critical-flow refrigeration cycle would provide space cooling, similar to a chiller, by running a secondary fluid such as water or glycol over one or more nozzles. Rather than utilizing a compressor to raise the pressure of the refrigerant, as in a vapor-cycle system, the critical-flow cycle utilizes a high-pressure pump to drive refrigerant liquid through the cooling cycle. Additionally, the design of the nozzle can be tailored for a given refrigerant, such that environmentally benign substances can act as the working fluid. This refrigeration cycle is still in early-stage development with prototype development several years away. The complex multi-phase flow at supersonic conditions presents numerous challenges to fully understanding and modeling the cycle. With the support of DOE and venture-capital investors, initial research was conducted at PAX Streamline, and later, at Caitin. We (researchers at Kansas State University) have continued development of the cycle and have gained an in-depth understanding of the governing fundamental knowledge, based on the laws of physics and thermodynamics and verified with our testing results. Through this research, we are identifying optimal working fluid and operating conditions to eventually demonstrate the core technology for space cooling or other applications.

Hosni, Mohammad H.

2014-03-30T23:59:59.000Z

339

Experimental study on heat transfer to supercritical water flowing through tubes  

SciTech Connect (OSTI)

A test facility named SWAMUP (Supercritical Water Multi-Purpose Loop) has been constructed in Shanghai Jiao Tong Univ. to investigate heat transfer and pressure drop through tubes and rod bundles. SWAMUP is a closed loop with operating pressure up to 30 MPa, outlet-water temperature up to 550 deg. C, and mass flow rate up to 5 t/h. In this paper, experimental study has been carried out on heat transfer of supercritical water flowing vertically through tubes (ID=7.6 and 10 mm). A large number of test points in tubes has been obtained with a wide range of heat flux (200-1500 kw/m{sup 2}) and mass flux (450-2000 kg/m{sup 2}s). Test results showed that heat transfer deterioration (HTD) caused by buoyancy effect only appears in upward flow and HTD caused by acceleration effect appears both in upward flow and downward flow. The heat transfer coefficients (HTC) produced in tube tests were compared with existing heat transfer correlations. (authors)

Zhao, M.; Gu, H.; Cheng, X. [School of Nuclear Science and Engineering, Shanghai Jiao Tong Univ. SJTU, 800 Dongchuan Road, Shanghai (China)

2012-07-01T23:59:59.000Z

340

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

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.


341

Heat Transfer in Wedge Flow of a Micropolar Fluid  

Science Journals Connector (OSTI)

The theory of fluids with microstructures was first given by Eringen ... , 1965), and they are called micropolar fluids. These fluids exhibit microrotational effects and microrotational inertia. The flow of such

V. M. Soundalgekar; H. S. Takhar

1980-01-01T23:59:59.000Z

342

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

SciTech Connect (OSTI)

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

343

Cooling the ANL SC heavy-ion linac with two refrigerators in parallel. Preprint Paper G-26  

SciTech Connect (OSTI)

The Argonne Superconducting Heavy-Ion Linac consists of a series of niobium accelerating resonators grouped in cryostats. The resonators are cooled by a forced-circulation flow of liquid helium directly from a CTI Model 1400 refrigerator through a low-loss distribution line. Helium entering each cryostat is condensed to near liquid saturation by heat exchange with the colder, lower pressure return stream. As more resonators and cryostats have been added to the linac over the past few years, it has been necessary to increase the cooling capacity of the system without increasing the flow of helium through the outgoing primary side of the distribution line and the resonators. This has been accomplished by coupling the first operational CTI Model 2800 turbo-expander refrigerator in parallel with the Model 1400 in such a way as to avoid major modifications in the helium distribution system.

Nixon, J.M.; Bollinger, L.M.

1981-01-01T23:59:59.000Z

344

Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns  

SciTech Connect (OSTI)

Closed-loop Brayton cycles using supercritical carbon dioxide (SCO{sub 2}) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO{sub 2} Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO{sub 2} Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO{sub 2} flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

Carlson, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States); Kruizenga, A. [Sandia National Laboratory (United States); Anderson, M.; Corradini, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States)

2012-07-01T23:59:59.000Z

345

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network [OSTI]

be modeled as a classical blowing and suction problem, i. e. ?(00) = v(00) = o ?(I, p) = v(L0) = 0 ?(x, 0) = ?(x, H) = 0 i(x, 0) = v(x), v(x, H) = -i'(x) 0&x&I. , (2. 6) v(x, 0) = 0, v(x, H) = 0 I. , &x&(L, +L, ) i(x, 0) = -v(x), v(x, H) = v(x) (L, +L... are considerably smoother and appear more reasonable Figure 5. 6 presents the velocity vector which is under q=40W/cm2, H=0. 003m uniform heat flux linear heat flux 0 00 0 O'I 0 02 0. 03 0. 04 0. 05 0 06 x(m) Fig. 5. 2 Heat flux distribution influence...

Liu, Xiaoqin

2012-06-07T23:59:59.000Z

346

Comparative performance evaluation of cascaded air-source hydronic heat pumps  

Science Journals Connector (OSTI)

Abstract The results are reported of an investigation of the effects of cascading air-source heat pumps on performance for hydronic residential systems. Three heat pump systems are modeled as single-stage, single-refrigerant cascaded, and two-refrigerant cascaded. Energy and exergy analyses are performed, and a comparative performance analysis is carried out, considering energy efficiency, refrigerant mass flow rates, evaporator pressure, exergy efficiency, and several other criteria. Three sets of source and supply temperatures, representing different climates and different water sink systems (low, medium and high temperature), are used to provide more comprehensive behavior assessments of the systems. Additionally, the optimum intermediate pressure of the cascaded systems for all working temperature pairs is found for the highest energetic COP and exergetic COP. Compared to a single stage heat pump, cascading improves the overall energy efficiency of the system for low-ambient temperatures, but not for high-ambient temperatures. Although this improvement is minor, the exergetic COP is increased by 67% for the single refrigerant cascaded system and 70% for a two-refrigerant cascaded system, at low ambient temperatures. Using refrigerant R404A in the low-pressure cycle marginally improves the energetic COP of the cascaded heat pump, but increases the evaporator working pressure, making it possible to use smaller compressors. However, the overall refrigerant mass flow rates increase with cascading. The two cascaded systems have higher exergy destructions (by almost four times) compared to the single stage system, mainly due to having more components, including an intermediate heat exchanger. Also, cascading shifts the major exergy destruction centers from the compressors and expansion valves to the evaporators. A comparison of cascaded and single-stage heat pumps shows that the exergy analysis results exhibit a different trend than energy analysis results with source and supply temperatures, highlighting the advantages of exergy methods in determining if cascading is appropriate for a given application.

R. Soltani; I. Dincer; M.A. Rosen

2015-01-01T23:59:59.000Z

347

NEW DESIGN OF NEON REFRIGERATOR FOR HTS POWER MACHINES  

Science Journals Connector (OSTI)

In 2007 we developed a prototype refrigerator with a small turbo?expander to provide adequate cooling power (2 kW at 70 K) for HTS (High Temperature Superconductor) power machines. The reverse?Brayton cycle with neon gas as a working fluid was adopted in the refrigerator. The prototype refrigerator does not have enough COP (Coefficient of Performance) for practical HTS applications and the purpose of this study is to research the information required for designing a new neon refrigerator with improved performance. We take the same refrigeration cycle and working fluid as the prototype one adopted but a lower process pressure of 1 MPa/0.5 MPa is chosen instead of 2 MPa/1 MPa. The lower process pressure is required by the turbo?compressor design and the refrigeration process is analyzed by using a newly developed process simulator. Also a heat?exchanger configuration is studied to make the refrigerator size small. The new refrigerator will have a cooling power of 2.5 kW at 65 K and a COP of 0.06 at 80 K.

S. Yoshida; H. Hirai; A. Takaike; M. Hirokawa; Y. Aizawa; Y. Kamioka; H. Okamoto; H. Hayashi; Y. Shiohara

2010-01-01T23:59:59.000Z

348

Energy efficiency improvements utilising mass flow control and a ring topology in a district heating network  

Science Journals Connector (OSTI)

Abstract Heating and cooling have a major role in the energy sector, covering 46% of total final energy use worldwide. District heating (DH) is a significant technology for improving the energy efficiency of heating systems in communities, because it enables waste heat sources to be utilised economically and therefore significantly reduces the environmental impacts of power generation. As a result of new and more stringent construction regulations for buildings, the heat demands of individual buildings are decreasing and more energy-efficient heating systems have to be developed. In this study, the energy efficiency of a new DH system which includes both a new control system called mass flow control and a new network design called a ring network is examined. A topology in the Helsinki region is studied by using a commercial DH network modelling tool, Grades Heating. The district heating network is attached to a wood-burning heat station which has a heat recovery system in use. Examination is performed by means of both technical and economic analysis. The new non-linear temperature programme that is required is adopted for supply and return temperatures, which allows greater temperature cooling and smaller flow rates. Lower district heating water temperatures are essential when reducing the heat losses in the network and heat production. Mass flow control allows smaller pressure drops in the network and thus reduces the pumping power. The aim of this study was to determine the most energy-efficient DH water supply temperatures in the case network. If the ring network design is utilised, the district heating system is easier to control. As a result the total heat consumption within the heating season is reduced compared to traditional DH systems. On the basis of the results, the new DH system is significantly more energy-efficient in the case network that was examined than the traditional design. For example, average energy losses within the constraints (which consist of heat losses, pumping energy, and surplus energy from the heat recovery system) are reduced from 4.4% to 3.1%.

Tatu Laajalehto; Maunu Kuosa; Tapio Mkil; Markku Lampinen; Risto Lahdelma

2014-01-01T23:59:59.000Z

349

A numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat transfer at microscale  

E-Print Network [OSTI]

Computational fluid dynamics Microchannel Minichannel Surface roughness Roughness elements Heat transfer Fluid to achieve enhancement in heat transfer with relatively low cooling fluid flow rate [1]. In spite of havingA numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat

Kandlikar, Satish

350

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls  

E-Print Network [OSTI]

PIV flow measurements for heat transfer characterization in two-pass square channels with smooth the correlation between the high- Reynolds number turbulent flow and wall heat transfer characteristics in a two number (Re) of 30,000. The PIV measurement results were compared with the heat transfer experimental data

Kihm, IconKenneth David

351

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON AND WILLIAM R. YOUNG  

E-Print Network [OSTI]

Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance ANDREW F. THOMPSON of these drag- less heat-flux parameterizations relies on the ability of to direct energy into zonal flows, California (Manuscript received 27 September 2006, in final form 13 December 2006) ABSTRACT The eddy heat

Young, William R.

352

Enhancing geothermal heat pump systems with parametric performance analyses.  

E-Print Network [OSTI]

??Parametric performance analyses and comparison of a basic geothermal heat pump, a heat pump cycle with motor cooling/refrigerant preheating, and a heat pump cycle utilizing (more)

Self, Stuart

2010-01-01T23:59:59.000Z

353

Causal heat flow in Bianchi type-V universe  

E-Print Network [OSTI]

In this paper we investigate the role of causal heat transport in a spatially homogeneous, locally-rotationally symmetric Bianchi type-V cosmological model. In particular, the causal temperature profile of the cosmological fluid is obtained within the framework of extended irreversible thermodynamics. We demonstrate that relaxational effects can alter the temperature profile when the cosmological fluid is out of hydrostatic equilibrium.

M. Govender; S. Thirukkanesh

2014-04-11T23:59:59.000Z

354

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

SciTech Connect (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

355

Application of Cryocoolers to a Vintage Dilution Refrigerator  

SciTech Connect (OSTI)

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

356

Downhole pulse tube refrigerators  

SciTech Connect (OSTI)

This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

Swift, G.; Gardner, D. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

1997-12-01T23:59:59.000Z

357

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

SciTech Connect (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

358

Super energy saver heat pump with dynamic hybrid phase change material  

DOE Patents [OSTI]

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

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

2010-07-20T23:59:59.000Z

359

Study Of a Solar Trough Concentrating System for Application of Solar Energy Refrigeration  

Science Journals Connector (OSTI)

A solar concentrating trough device has been constructed for further application of solar heating and power system or solar refrigeration. A model for both evacuated tube and copper tube heated by solar trough co...

Li Ming; Wang Liuling; Zhou Xizheng

2009-01-01T23:59:59.000Z

360

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...

McJimsey, Bert Ashford

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

Numerical Studies of Fluid Leakage from a Geologic Disposal Reservoir for CO2 Show Self-Limiting Feedback between Fluid Flow and Heat Transfer  

E-Print Network [OSTI]

Feedback between Fluid Flow and Heat Transfer Karsten Pruessfeedback between fluid flow and heat transfer tends to limitfluid mobility (viscosity and relative permeability effects), are countered by effects arising from limitations in the rate of conductive heat transfer.

Pruess, Karsten

2005-01-01T23:59:59.000Z

362

Proceedings: Commercial Refrigeration Research Workshop  

SciTech Connect (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.

None

1984-10-01T23:59:59.000Z

363

Heat transfer during the flow of an incompressible fluid in a circular tube, allowing for axial heat flow, with boundary conditions of the first and second kind at the tube surface  

Science Journals Connector (OSTI)

An examination is made of heat transfer in a hydraulically stabilized laminar stream and in a two-layer dynamic flow model.

V. V. Shapovalov

1966-09-01T23:59:59.000Z

364

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...

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

1996-01-01T23:59:59.000Z

365

Refrigerator recycling and CFCs  

SciTech Connect (OSTI)

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

366

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

E-Print Network [OSTI]

-1209(h) Office Hours: M-F 1-2p.m. Text: Heating, Ventilating, and Air Conditioning - Analysis and Design. -- Refrigeration and heating, ventilating and air-conditioning (HVAC) for comfort and industrial applications of the fundamentals of Heating, Ventilating, Air Conditioning, and Refrigeration as they relate to human comfort

Dyer, Bill

367

Helium dilution refrigeration  

E-Print Network [OSTI]

. 1875" OD exchanger Qu ID copper cap Fig. 6. Assembled view of 3He - He dilution refrigerator. 26 The joint thru the tubing wall and the joining of the two sizes of capillary were silver soldered (35/ silver content). A 0. 250" OD tube... the inert atmosphere inside the refrigerator. After removal from the nitrogen atmosphere the graphite support, was 'attached to the still and mixing chamber using Stycast 2850 GT with catalyst g9 ). The mass of the graphite 26 support 1s 11. 62 grams...

McKee, Thomas Raymond

2012-06-07T23:59:59.000Z

368

Enhanced naphthenic refrigeration oils for household refrigerator systems  

SciTech Connect (OSTI)

Due to industry concerns about the successful employment of hydrofluorocarbon-immiscible hydrocarbon oils in refrigeration systems, enhanced naphthenic refrigeration oils have been developed. These products have been designed to be more dispersible with hydrofluorocarbon (HFC) refrigerants, such as R-134a, in order to facilitate lubricant return to the compressor and to ensure proper energy efficiency of the system. Bench tests and system performance evaluations indicate the feasibility of these oils for use in household refrigeration applications. Results of these evaluations are compared with those obtained with polyol esters and typical naphthenic mineral oils employed in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) refrigeration applications.

Reyes-Gavilan, J.L.; Flak, G.T.; Tritcak, T.R. [Witco Corp., Oakland, NJ (United States); Barbour, C.B. [Americold, Cullman, AL (United States)

1997-12-31T23:59:59.000Z

369

Tapered pulse tube for pulse tube refrigerators  

DOE Patents [OSTI]

Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

Swift, Gregory W. (Sante Fe, NM); Olson, Jeffrey R. (San Mateo, CA)

1999-01-01T23:59:59.000Z

370

Flow patterns and heat transfer around six in-line circular cylinders at low Reynolds number  

E-Print Network [OSTI]

The flow field and the heat transfer around six in-line iso-thermal circular cylinders has been studied by mean of numerical simulations. Two values of the center to center spacing ($s=3.6d$ and $4d$, where $d$ is the cylinder diameter) at Reynolds number of $100$ and Prandtl number of $0.7$ has been investigated. Similarly to the in-line two cylinder configuration, in this range a transition in the flow and in the heat transfer occurs. Two different flow patterns have been identified: the stable shear layer (SSL) mode and the shear layer secondary vortices (SLSV) mode, at $3.6$ and $4$ spacing ratio ($s/d$), respectively. At $s/d=3.6$ the flow pattern causes the entrainment of cold fluid on the downstream cylinders enhancing the heat transfer. On the other hand at $s/d=4$ two stable opposite shear layer prevent the cold fluid entrainment over the downstream cylinders reducing their heat exchange. The overall time average heat transfer of the array is enhanced up to 25% decreasing the spacing ratio from $4$ t...

Fornarelli, Francesco; Lippolis, Antonio

2014-01-01T23:59:59.000Z

371

Effects of lithospheric rigidity on ocean floor bathymetry and heat flow  

SciTech Connect (OSTI)

The observed quasi-rigid behaviour of surface plates in the course of their relative motion is a consequence of the high viscosity which obtains in the cold near surface region. By assigning a particular constant velocity as the upper boundary condition in a numerical model of mantle convection, we have investigated the effect of lithospheric rigidity on the variation of oceanic bathymetry and heat flow as a function of ocean floor age. Predicted variations of both bathymetry and heat flow at the surface of mantle wide convection cells which are partially heated from within, exhibit the same qualitative behaviour as data compiled for the major ocean basins. The bathymetry varies with distance x from the spreading centre initially as x/sup 1/2/ but subsequently flattens with respect to an x/sup 1/2/ reference curve whereas the heat flow closely follows an x-/sup 1/2/ decay over most of the convection cell. Consequently the viability of the mechanism for sea floor flattening proposed by Jarvis and Peltier (1980) is increased when a constant surface velocity, characteristic of rigid plates, is incorporated in the model. This model successfully predicts both that the bathymetry should flatten and that the heat flow should not.

Jarvis, G.T.; Peltier, W.R.

1981-08-01T23:59:59.000Z

372

Experimental study of heat flows in the walls of a high-enthalpy mhd channel  

SciTech Connect (OSTI)

This article reports results of experimental studies of local heat flows in the walls of an MHD channel during different regimes of its operation. Special attention was given to aspects of the reliability of measurement of heat flow to B-walls. Tests were conducted on a unit consisting of a Faraday MHD channel with sectional electrodes operating in the accelerator regime. A basic diagram of the unit is shown. Tests were conducted with the primary nozzle and power was supplied along zones 160 and 280 mm long. The data obtained were analyzed using the electrogasdynamic flow pattern established for each regime from numerical solution of a system of quasiunidimensional magnetogasdynamic equations. Results are presented of measurement and analysis of gasdynamic and electrodynamic characteristics of flow in the MHD channel.

Alferov, V.I.; Rudakova, A.P.; Shcherbakov, G.I.; Sukhobokov, A.D.; Vitskoskaya, O.N.

1986-01-01T23:59:59.000Z

373

Effect of heat transfer on the plane-channel poiseuille flow of a thermo-viscous fluid  

Science Journals Connector (OSTI)

A steady-state plane channel flow of viscous incompressible fluid with no-slip and heat transfer boundary conditions is considered. The flow is ... induced by a fixed pressure difference and the fluid viscosity d...

S. N. Aristov; V. G. Zelenina

374

Electrically heated particulate filter with zoned exhaust flow control  

DOE Patents [OSTI]

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

375

Interpreting Velocities from Heat-Based Flow Sensors by NumericalSimulation  

SciTech Connect (OSTI)

We have carried out numerical simulations of three-dimensional non-isothermal flow around an in situ heat-based flow sensor to investigate how formation heterogeneities can affect the interpretation of ground water flow velocities from this instrument. The flow sensor operates by constant heating of a 0.75 m long, 5 cm diameter cylindrical probe, which contains 30 thermistors in contact with the formation. The temperature evolution at each thermistor can be inverted to obtain an estimate of the ground water flow velocity vector using the standard interpretive method, which assumes that the formation is homogeneous. Analysis of data from heat-based flow sensors installed in a sand aquifer at the Former Fort Ord Army Base near Monterey, California suggested an unexpected component of downward flow. The magnitudes of the vertical velocities were expected to be much less than the horizontal velocities at this site because the sensors were installed just above a clay aquitard. Numerical simulations were conducted to examine how differences in thermal conductivities may lead to spurious indications of vertical flow velocities. We found that a decrease in the thermal conductivity near the bottom of the sensor can perturb the temperature profiles along the instrument in such a manner that analyses assuming homogeneous thermal conductivity could indicate a vertical flow component even though flow is actually horizontal. This work demonstrates how modeling can be used to simulate instrument response to formation heterogeneity, and shows that caution must be used in interpreting data from such devices using overly simplistic assumptions.

Su, Grace W.; Freifeld, Barry M.; Oldenburg, Curtis M.; Jordan,Preston D.; Daley, Paul F.

2005-06-13T23:59:59.000Z

376

Compressor calorimeter performance of refrigerant blends: Comparative methods and results for a refrigerator/freezer application  

SciTech Connect (OSTI)

A protocol was developed to define calorimeter operating pressures for nonazeotropic refrigerant mixtures (NARMs) which corresponded with the saturated evaporator and condenser temperatures commonly used for pure refrigerants. Compressor calorimeter results were obtained using this equivalent-mean-temperature (EMT) approach and a generally applied Association of Home Appliance Manufacturers (AHAM) procedure at conditions characteristic of a domestic refrigerator-freezer application. Tests with R-12 and two NARMs indicate that compressor volumetric and isentropic efficiencies are nearly the same for refrigerants with similar capacities and pressure ratios. The liquid-line temperature conditions specified in the AHAM calorimeter rating procedure for refrigerator-freezer compressors were found to preferentially derate NARM performance relative to R-12. Conversion of calorimeter data taken with a fixed liquid-line temperature to a uniform minimal level of condenser subcooling is recommended as a fairer procedure when NARMs are involved. Compressor energy-efficiency-ratio (EER) and capacity data measured as a result of the EMT approach were compared to system performance calculated using an equivalent-heat-exchanger-loading (EHXL) protocol based on a Lorenz-Meutzner (L-M) refrigerator-freezer modeling program. The EHXL protocol was used to transform the calorimeter results into a more relevant representation of potential L-M cycle performance. The EMT method used to set up the calorimeter tests and the AHAM liquid-line conditions combined to significantly understate the cycle potential of NARMs relative to that predicted at the more appropriate EHXL conditions. Compressor conditions representative of larger heat exchanger sizes were also found to give a smaller L-M cycle advantage relative to R-12.

Rice, C K; Sand, J R

1993-01-01T23:59:59.000Z

377

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

378

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

379

Solid-vapor adsorption-refrigeration system development. Final report, March 1990-May 1991  

SciTech Connect (OSTI)

The study describes the development of heat-activated industrial refrigeration systems using ammoniated complex compound sorption media. The focus was on single-stage cycles for low temperature (+20 F and below) refrigeration. Compared to vapor compression refrigeration, these cycles have the advantages of lower operating energy costs, reduction of peak electrical demand and associated demand charges, and reduced maintenance costs due to replacement of the compressor with solid-state sorbers. In many cases, particularly for refrigeration at -40 F and below, complex compound sorption cycles also have the potential for lower first cost than conventional electrically driven refrigeration systems. Technical issues addressed included the following: economic optimization of sorber design, demonstration of cyclic stability of the sorption reactions, construction material compatibility, and reactor scale-up. Sorption reactions for refrigeration at -40 F, and -70 F were demonstrated. Optimum heat exchanger configuration, complex compound loading, and cycle time were determined.

Rockenfeller, U.; Kirol, L.; Graebel, B.

1991-12-01T23:59:59.000Z

380

Improving the energy efficiency of refrigerators in India  

SciTech Connect (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

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

Terrestrial Heat Flow and Heat Generation in South-west England  

Science Journals Connector (OSTI)

......the Wilsey Down borehole, and of heat...located over the large underlying batholith...the Wilsey Down borehole lies just beyond...the effects of drilling had subsided and...length of the borehole, I6 months after drilling ceased. At Geevor......

H. Y. Tammemagi; J. Wheildon

1974-07-01T23:59:59.000Z

382

Buoyancy driven flow in a hot water tank due to standby heat loss  

Science Journals Connector (OSTI)

Results of experimental and numerical investigations of thermal behavior in a vertical cylindrical hot water tank due to standby heat loss of the tank are presented. The effect of standby heat loss on temperature distribution in the tank is investigated experimentally on a slim 150l tank with a height to diameter ratio of 5. A tank with uniform temperatures and with thermal stratification is studied. A detailed computational fluid dynamics (CFD) model of the tank is developed to calculate the natural convection flow in the tank. The distribution of the heat loss coefficient for the different parts of the tank is measured by experiments and used as input to the CFD model. Water temperatures at different levels of the tank are measured and compared to CFD calculated temperatures. The investigations focus on validation of the CFD model and on understanding of the CFD calculations. The results show that the CFD model predicts satisfactorily water temperatures at different levels of the tank during cooling by standby heat loss. It is elucidated how the downward buoyancy driven flow along the tank wall is established by the heat loss from the tank sides and how the natural convection flow is influenced by water temperatures in the tank. When the temperature gradient in the tank is smaller than 2K/m, there is a downward fluid velocity of 0.0030.015m/s. With the presence of thermal stratification the buoyancy driven flow is significantly reduced. The dependence of the velocity magnitude of the downward flow on temperature gradient is not influenced by the tank volume and is only slightly influenced by the tank height to tank diameter ratio. Based on results of the CFD calculations, an equation is determined to calculate the magnitude of the buoyancy driven flow along the tank wall for a given temperature gradient in the tank.

Jianhua Fan; Simon Furbo

2012-01-01T23:59:59.000Z

383

An ammonia refrigerator with an absorption circuit as economizer  

Science Journals Connector (OSTI)

The experimental results of a compression refrigerator with an integrated solution circuit, a so-called compression-absorption cycle, are presented. The compression refrigerator operates with ammonia (NH3) as refrigerant. The cycle is improved by two-stage throttling of the condensate and an absorption circuit which replaces the economizer compressor. The absorption circuit operates on the working pair ammonia/water (NH3/H2O). It is driven by superheat of the compressor without additional heat input from an external source. By this means the benefit of two-stage throttling, namely a reduction in compression work or an increase in refrigeration capacity, can be doubled. In the experiments an improvement of up to 9% in the efficiency of the NH3-refrigeration cycle has been attained. Compared to a simple compression refrigerator, the presented compression-absorption cycle has a payback time of only several months. Compared to a conventional economizer refrigeration cycle, the payback can be expected within the range of several months to about four years.

F Ziegler; U Spindler

1993-01-01T23:59:59.000Z

384

Optimization of Industrial Refrigeration Plants: Including a Case Study at Stonyfield Farm Yogurt  

E-Print Network [OSTI]

MARKET Table 1 below presents information on the manufacturing industries that are intensive in process cooling and refrigeration (PC&R) energy consumption as monitored by the US Energy Information Administration (EIA). The information in Table 1... Expansion (DX), Pumped Liquid Overfeed, Flooded shell and tube and Plate heat exchangers. Evaporators in the refrigerated space can contribute as much as 10 to 15% of the energy consumption in an industrial refrigeration system and therefore...

Dixon, R.; McCowan, B.; Drake, L.; Epstein, G.; D'Antonio, M.; Moray, S.

2006-01-01T23:59:59.000Z

385

Chemical heat pump cools as well as heats  

Science Journals Connector (OSTI)

Chemical heat pump cools as well as heats ... Innovative heat pump uses methanol refrigerant, calcium chloride absorber to use and store solar energy for heating, air conditioning, hot water ... Though the EIC heat pump is similar in concept to other chemical heat pumps now being used or developed, it does offer a number of innovations, not the least of which are its novel refrigerant (methanol) and absorption medium (calcium chloride). ...

RON DAGANI

1980-10-20T23:59:59.000Z

386

Solutions of turbulent backward-facing step flow with heat transfer using the finite volume method  

SciTech Connect (OSTI)

The heated turbulent flow over a backward-facing step is numerically solved using the commercial computational fluid dynamics program FLUENT. The methods used here consist of the default power-law upwinding scheme, default multigrid equation solution method and a standard k-{var_epsilon} turbulence model with wall functions. A total of four separate cases are reported. The four cases consist of combinations of partially and fully developed flow at the inlet with uniform or developed temperature profiles. Three mesh refinements are reported for each flow.

Horstman, R.H. [Boeing Commercial Airplane, Seattle, WA (United States). Environmental Control Systems R& D; Cochran, R.J. [Sandia National Labs., Albuquerque, NM (United States); Emergy, A.F. [Univ. of Washington, Seattle, WA (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

387

Global Thermodynamic Analysis of Heat Engines Frank Rioux  

E-Print Network [OSTI]

and refrigerators. The analyses provided are based on the skematic diagram shown below. The system is a working the ideal, theoretical limit, Stot =0. Refrigerator A refrigerator is also a heat pump. However, with a refrigerator we are interested in how much energy we can pump out of the low temperature reservoir (the

Rioux, Frank

388

Flow and Heat-Transfer Apparatus, Instrumentation and Data Acquisition Method  

E-Print Network [OSTI]

friction and convective heat transfer characteristics of nanofluids. Instead of a usual closed-loop system where pumps and after-cooling units are required, the developed apparatus utilizes nitrogen pressure-driven flow to test a single batch of fluid. This reduces the complexity of the system while improving its

Kostic, Milivoje M.

389

November 28, 2006 Seismologists get handle on heat flow deep in earth  

E-Print Network [OSTI]

November 28, 2006 Seismologists get handle on heat flow deep in earth Earth's interior placid inner Earth as a dynamic environment filled with exotic materials and substances roiling under that has an impact on what happens on our planet's surface. The latest evidence of this dynamic inner Earth

Garnero, Ed

390

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows  

E-Print Network [OSTI]

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows K Magnetic fields a b s t r a c t The ice giant planets, Uranus and Neptune, have magnetic fields to yield small-scale and disorganized turbulence. In agreement with ice giant observations, both

391

INFLUENCE OF OHMIC HEATING ON ADVECTION-DOMINATED ACCRETION FLOWS G. S. BISNOVATYI-KOGAN  

E-Print Network [OSTI]

is advected inward, and the fraction 1 f is locally radiated. The further assumption that the energy exchange that the dissipation of turbulent energy of the flow heats the ions and that 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

392

Experimental shellside flow visualization in a shell and tube heat exchanger  

E-Print Network [OSTI]

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

Fischer, Matthew Winslow

1998-01-01T23:59:59.000Z

393

Numerical simulation of fluid flow and heat transfer in a passage with moving boundary  

Science Journals Connector (OSTI)

In this paper, a method is presented in detail that can be used to solve the fluid flow and heat transfer in domains with moving boundaries. The primitive variables formulation is adopted and a non-staggered grid, with Cartesian velocity components used as the primary unkowns in the momentum equations, is utilised. Discretisation is carried out using a control-volume method, the simplified QUICK scheme combined with a deferred correction approach is adopted for the convective fluxes and implicit time stepping is used for temporal differencing. The well-known SIMPLE algorithm is employed for handling the velocity??pressure coupling. The computational method is applied for the prediction of fluid flow and heat transfer in a channel with a boundary moving in a prescribed manner. Results show that both the amplitude and Strouhal number have great influences on the characteristics of fluid flow and heat transfer, and in the range studied, the heat transfer rate increases monotonously with the amplitude, whereas the Strouhal number only has a small effect on heat transfer.

D. S. Zhang; Q. W. Wang; W. Q. Tao

2002-01-01T23:59:59.000Z

394

Inferring temperature uniformity from gas composition measurements in a hydrogen combustion-heated hypersonic flow stream  

SciTech Connect (OSTI)

The application of a method for determining the temperature of an oxygen-replenished air stream heated to 2600 K by a hydrogen burner is reviewed and discussed. The purpose of the measurements is to determine the spatial uniformity of the temperature in the core flow of a ramjet test facility. The technique involves sampling the product gases at the exit of the test section nozzle to infer the makeup of the reactant gases entering the burner. Knowing also the temperature of the inlet gases and assuming the flow is at chemical equilibrium, the adiabatic flame temperature is determined using an industry accepted chemical equilibrium computer code. Local temperature depressions are estimated from heat loss calculations. A description of the method, hardware and procedures is presented, along with local heat loss estimates and uncertainty assessments. The uncertainty of the method is estimated at {+-}31 K, and the spatial uniformity was measured within {+-}35 K.

Olstad, S.J. [Phoenix Solutions Co., Minneapolis, MN (United States)

1995-08-01T23:59:59.000Z

395

Turbulent heat transfer in a channel flow at transitional Reynolds numbers  

E-Print Network [OSTI]

Direct numerical simulation of a turbulent channel flow with heat transfer was performed at very low Reynolds numbers. Two different thermal boundary conditions were studied, and temperature was considered as a passive scalar. The computations were carried out with huge computational boxes (up to 327.7 x 2 x 128 in the streamwise, wall-normal, and spanwise directions, respectively). The emphases of this paper are to investigate the large-scale structure (puff) in the intermittent-turbulent flow including the scalar fields and to provide the values of the transitional and critical Reynolds numbers, below which the turbulent flow becomes intermittent and laminar, respectively. The statistics, such as the skin friction and the Stanton number, were also examined: they suggest that the puff should be effective in sustaining turbulence and in heat transfer enhancement.

Tsukahara, Takahiro

2014-01-01T23:59:59.000Z

396

Group solution for unsteady free-convection flow from a vertical moving plate subjected to constant heat flux  

Science Journals Connector (OSTI)

The problem of heat and mass transfer in an unsteady free-convection flow over a continuous moving vertical sheet in an ambient fluid is investigated for constant heat flux using the group theoretical method. The nonlinear coupled partial differential ... Keywords: 22E05, 35Q53, 54H15, Free convective flow, Group theoretic method, Prandtl number, Thermal boundary layer

M. Kassem

2006-03-01T23:59:59.000Z

397

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

SciTech Connect (OSTI)

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

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

2010-11-15T23:59:59.000Z

398

Asset Management Equipment Disposal Form -Refrigerant Recovery  

E-Print Network [OSTI]

enters the waste stream with the charge intact (e.g., motor vehicle air conditioners, refrigeratorsAsset Management Equipment Disposal Form - Refrigerant Recovery Safe Disposal Requirements Under refrigeration, cold storage warehouse refrigeration, chillers, and industrial process refrigeration) has to have

Sin, Peter

399

The application of Stirling cooler to refrigeration  

SciTech Connect (OSTI)

The application field of the free-piston Stirling Cooler, Model 100A of Global Cooling BV in the refrigeration has been studied. The cooling effectiveness of the free-piston Stirling Cooler which means small capacity with better efficiency, large range of temperature and capacity modulated operation is of much use to cool a space insulated well. One practicable application is suggested here, in which FPSC and secondary heat transfer fluid are used to the single temperature refrigerator (60 liter) instead of conventional vapor compression machines. In the freezer operation at {minus}20 C inside cabinet, the steady-state test results show 25% improvement in energy consumption over original one. The application of free-piston Stirling Cooler to a freezer at lower temperature shows great potentials also.

Kim, S.Y.; Chung, W.S.; Shin, D.K.; Cho, K.S. [LG Electronics Inc., Seoul (Korea, Republic of). Living System Lab.

1997-12-31T23:59:59.000Z

400

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 Eindhoven (The Netherlands)  

E-Print Network [OSTI]

EUROTHERM Seminar 74 Proceedings Heat transfer in unsteady and transitional flows March 23-26, 2003 to be governed by heat transfer and time microscales of turbulence through the inner sublayer. Physical interpreta- tions are given to relate the observed heat transfer correlation and these turbulence transition

Paris-Sud XI, Université de

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

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

E-Print Network [OSTI]

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

402

Exergy analysis of second-generation micro heat sinks under single-phase and flow boiling conditions  

Science Journals Connector (OSTI)

A parametric study of exergy efficiency was conducted for five micro pin fin heat sinks of different spacing and shapes. Of the four micro pin fin heat sinks tested under single-phase flow conditions, those with better heat transfer performance yielded superior exergy efficiencies. The use of R-123 in place of water as working fluid was found to enhance exergetic performance at the expense of reduced heat transfer performance. The exergy analysis was also extended to the flow boiling of R-123 in an additional hydrofoil-based micro pin fin heat sink. It was found that exergy efficiencies decreased with mass velocity.

Ali Kosar

2010-01-01T23:59:59.000Z

403

Multilayer Thermionic Refrigeration  

SciTech Connect (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

404

Heat transfer deterioration in tubes caused by bulk flow acceleration due to thermal and frictional influences  

SciTech Connect (OSTI)

Severe deterioration of forced convection heat transfer can be encountered with compressible fluids flowing through strongly heated tubes of relatively small bore as the flow accelerates and turbulence is reduced because of the fluid density falling (as the temperature rises and the pressure falls due to thermal and frictional influence). The model presented here throws new light on how the dependence of density on both temperature and pressure can affect turbulence and heat transfer and it explains why the empirical equations currently available for calculating effectiveness of forced convection heat transfer under conditions of strong non-uniformity of fluid properties sometimes fail to reproduce observed behaviour. It provides a criterion for establishing the conditions under which such deterioration of heat transfer might be encountered and enables heat transfer coefficients to be determined when such deterioration occurs. The analysis presented here is for a gaseous fluid at normal pressure subjected strong non-uniformity of fluid properties by the application of large temperature differences. Thus the model leads to equations which describe deterioration of heat transfer in terms of familiar parameters such as Mach number, Reynolds number and Prandtl number. It is applicable to thermal power plant systems such as rocket engines, gas turbines and high temperature gas-cooled nuclear reactors. However, the ideas involved apply equally well to fluids at supercritical pressure. Impairment of heat transfer under such conditions has become a matter of growing interest with the active consideration now being given to advanced water-cooled nuclear reactors designed to operate at pressures above the critical value. (authors)

Jackson, J. D. [Univ. of Manchester, Manchester (United Kingdom)

2012-07-01T23:59:59.000Z

405

The influence of convective heat transfer on flow stability in rotating disk chemical vapor deposition reactors  

SciTech Connect (OSTI)

Flow and heat transfer of NH{sub 3} and He were studied in a rotating disk system with applications to chemical vapor deposition reactors. Flow field and disk heat flux were obtained over a range of operating conditions. Comparisons of disk convective heat transfer were made to infinite rotating disk results to appraise uniformity of transport to the disk. Important operating variables include disk spin rate, disk and enclosure temperatures, flow rate, composition, pressure, and gas mixture temperature at the reactor inlet. These variables were studied over ranges of the spin Reynolds number, Re{omega}; disk mixed convection parameter, MCP{sub w}; and wall mixed convection parameter, MCP{sub w}. Results obtained for NH{sub 3} show that increasing Re{omega} from 314.5 to 3145 increases the uniformity of rotating disk heat flux and results in thinner thermal boundary layers at the disk surface. At Re{omega}=314.5, increasing MCP{sub d} to 15 leads to significant departure from the infinite disk result with nonuniform disk heat fluxes and recirculating flow patterns; flow becomes increasingly complex at larger values of MCP{sub d}. At Re{omega} of 3145, results are closer to the infinite disk for MCP{sub d} up to 15. For large negative (hot walls) and positive (cold walls) values of MCP{sub w}, flow recirculates and there is significant deviation from the infinite disk result; nonuniformities occur at both values of Re{omega}. The influence of MCP{sub w} on flow stability is increased at larger MCP{sub d} and lower Re{omega}. To determine the influence of viscosity and thermal conductivity variation with temperature, calculations were made with He and NH{sub 3}; He transport property variation is low relative to NH{sub 3}. Results show that the flow of NH{sub 3} is less stable than that of He as MCP{sub d} is increased for MCP{sub w}=0 and Re{omega}=314.5. 16 refs., 15 figs., 1 tab.

Winters, W.S.; Evans, G.H. [Sandia National Labs., Livermore, CA (United States); Grief, R. [Univ. of California, Berkeley, CA (United States). Mechanical Engineering Dept.

1997-06-01T23:59:59.000Z

406

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]

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... of test points . Accuracy of the key system parameters. . 17 19 4. 1 Results &om gas chromatograph tests. 5. 1 Curve &t equations for charge as a function of mass flow rate at 35'C (95'F) outdoor room condition for R22 33 5. 2 Curve &t equations...

Robinson, Jay Hart

2012-06-07T23:59:59.000Z

407

Heat loss model for flow assurance in a deep water riser  

Science Journals Connector (OSTI)

The study is intended to investigate the heat loss phenomenon of oil flow in a riser. This heat loss happens due to the difference between the oil temperature in a riser and the surrounding sea water temperature. It causes the formation of wax that may disturb the flow. Heat loss can be reduced by setting up an insulator in a riser or by selecting appropriate pipeline specifications. It is necessary to determine the possible locations and specifications of insulator and pipeline. A mathematical model is formulated by considering the oil temperature and its flow velocity. Assuming that the density variation is small the fluid behaves as an incompressible fluid. Furthermore numerical solutions with finite difference methods are presented with some hypothetical data to give an overview of how the system works. Two surrounding conditions are taken into account i.e. with and without sea current. From the simulation the location of wax formation can be predicted. At a certain depth region of sea where the sea current is present a greater heat loss take place in which wax may be formed immediately. To overcome the formation of wax we can control the parameters such as conductivity and wall thickness of pipe.

Pudjo Sukarno

2014-01-01T23:59:59.000Z

408

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

SciTech Connect (OSTI)

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

409

Vaccine refrigerator testing. Final report  

SciTech Connect (OSTI)

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

410

Quantum refrigerators and the third law of thermodynamics  

Science Journals Connector (OSTI)

The rate of temperature decrease of a cooled quantum bath is studied as its temperature is reduced to absolute zero. The third law of thermodynamics is then quantified dynamically by evaluating the characteristic exponent ? of the cooling process dT(t)dt??T? when approaching absolute zero, T?0. A continuous model of a quantum refrigerator is employed consisting of a working medium composed either by two coupled harmonic oscillators or two coupled two-level systems. The refrigerator is a nonlinear device merging three currents from three heat baths: a cold bath to be cooled, a hot bath as an entropy sink, and a driving bath which is the source of cooling power. A heat-driven refrigerator (absorption refrigerator) is compared to a power-driven refrigerator. When optimized, both cases lead to the same exponent ?, showing a lack of dependence on the form of the working medium and the characteristics of the drivers. The characteristic exponent is therefore determined by the properties of the cold reservoir and its interaction with the system. Two generic heat bath models are considered: a bath composed of harmonic oscillators and a bath composed of ideal Bose/Fermi gas. The restrictions on the interaction Hamiltonian imposed by the third law are discussed. In the Appendices, the theory of periodically driven open systems and its implication for thermodynamics are outlined.

Amikam Levy; Robert Alicki; Ronnie Kosloff

2012-06-26T23:59:59.000Z

411

Influence of variable property effects on natural convection flows in asymmetrically-heated vertical channels  

SciTech Connect (OSTI)

The influence of variable property effects on the laminar air flow induced by natural convection in a vertical, asymmetrically-heated channel is investigated. A full-elliptic model that accounts for variations of viscosity and thermal conductivity with temperature and determines the density from the state equation, has been solved numerically for cases for which variable property effects are important, particularly for conditions for which flow reversals may appear. The corresponding numerical results are compared with those obtained from an alternative model in which all thermophysical properties are assumed to be constant and the Boussinesq approximation is used. It has been found that variable property effects have a strong influence, not reported in previous works, on the recirculation patterns, and may produce, for certain ranges of parameters that roughly coincide with those for which flow reversals exist, an increase in the mass flow rate induced in the channel.

Zamora, B. [Univ. de Murcia (Spain)] [Univ. de Murcia (Spain); Hernandez, J. [Ciudad Universitaria, Madrid (Spain)] [Ciudad Universitaria, Madrid (Spain)

1997-12-01T23:59:59.000Z

412

Micro-canonical thermodynamics: Why does heat flow from hot to cold  

E-Print Network [OSTI]

We consider two weakly coupled Hamiltonian dynamical systems in the micro-canonical ensemble. We describe a stochastic model for the energy-transfer between two systems initially at different micro-canonical temperatures. Fluctuations in energy observables are shown to be the underlying source of heat-transfer (dissipation). As a result, on average, heat flows from hot to cold. Like in Evans et al. (Phys.\\ Rev.\\ Lett.) [71], 2401 (1993), we obtain a universal law of violation of the 2nd law of thermodynamics.

Rugh, Hans Henrik

2012-01-01T23:59:59.000Z

413

The LSST Camera 500 watt -130 degC Mixed Refrigerant Cooling System  

SciTech Connect (OSTI)

The LSST Camera has a higher cryogenic heat load than previous CCD telescope cameras due to its large size (634 mm diameter focal plane, 3.2 Giga pixels) and its close coupled front-end electronics operating at low temperature inside the cryostat. Various refrigeration technologies are considered for this telescope/camera environment. MMR-Technologys Mixed Refrigerant technology was chosen. A collaboration with that company was started in 2009. The system, based on a cluster of Joule-Thomson refrigerators running a special blend of mixed refrigerants is described. Both the advantages and problems of applying this technology to telescope camera refrigeration are discussed. Test results from a prototype refrigerator running in a realistic telescope configuration are reported. Current and future stages of the development program are described. (auth)

Bowden, Gordon B.; Langton, Brian J.; Little, William A.; Powers, Jacob R; Schindler, Rafe H.; Spektor, Sam; /MMR-Technologies, Mountain View, CA

2014-05-28T23:59:59.000Z

414

E-Print Network 3.0 - adiabatic demagnetization refrigerator...  

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

refrigerator Search Powered by Explorit Topic List Advanced Search Sample search results for: adiabatic demagnetization refrigerator...

415

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

SciTech Connect (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

416

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

417

Heat transfer enhancement on thin wires in superfluid helium forced flows  

E-Print Network [OSTI]

In this paper, we report the first evidence of an enhancement of the heat transfer from a heated wire by an external turbulent flow of superfluid helium. We used a standard Pt-Rh hot-wire anemometer and overheat it up to 21 K in a pressurized liquid helium turbulent round jet at temperatures between 1.9 K and 2.12 K. The null-velocity response of the sensor can be satisfactorily modeled by the counter flow mechanism while the extra cooling produced by the forced convection is found to scale similarly as the corresponding extra cooling in classical fluids. We propose a preliminary analysis of the response of the sensor and show that -contrary to a common assumption- such sensor can be used to probe local velocity in turbulent superfluid helium.

Duri, Davide; Moro, Jean-Paul; Roche, Philippe-Emmanuel; Diribarne, Pantxo

2014-01-01T23:59:59.000Z

418

Review of fluid flow and convective heat transfer within rotating disk cavities with impinging jet  

E-Print Network [OSTI]

Fluid flow and convective heat transfer in rotor-stator configurations, which are of great importance in different engineering applications, are treated in details in this review. The review focuses on convective heat transfer in predominantly outward air flow in the rotor-stator geometries with and without impinging jets and incorporates two main parts, namely, experimental/theoretical methodologies and geometries/results. Experimental methodologies include naphthalene sublimation techniques, steady state (thin layer) and transient (thermochromic liquid crystals) thermal measurements, thermocouples and infra-red cameras, hot-wire anemometry, laser Doppler and particle image velocimetry, laser plane and smoke generator. Theoretical approaches incorporate modern CFD computational tools (DNS, LES, RANS etc). Geometries and results part being mentioned starting from simple to complex elucidates cases of a free rotating disk, a single disk in the crossflow, single jets impinging onto stationary and rotating disk,...

Harmand, Souad; Poncet, Sbastien; Shevchuk, Igor V; 10.1016/j.ijthermalsci.2012.11.009

2013-01-01T23:59:59.000Z

419

Boundary layer flow and heat transfer analysis of a second-grade fluid  

SciTech Connect (OSTI)

Boundary layer flow and heat transfer analysis of a homogeneous, incompressible, non-Newtonian fluid of grade two at a stagnation point is presented. The flow is assumed to be steady and laminar. A power-law representation is assumed for the velocity distribution and wall temperature variation. The governing equations are solved using an iterative central difference approximation method in a non-uniform grid domain. This analysis show the effect of non-Newtonian nature of the fluid and the effect of suction/injection on the velocity profile. The effect of non-Newtonian nature of the fluid on the heat transfer coefficient at the wall for different values of Prandtl number and wall-temperature variation is also presented. (VC)

Massoudi, M. [USDOE Pittsburgh Energy Technology Center, PA (United States); Ramezan, M. [Burns and Roe Services Corp., Pittsburgh, PA (United States)

1992-04-01T23:59:59.000Z

420

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect (OSTI)

As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers. The results are presented for an 18 cubic foot (0.51 cubic meter), top-mount refrigerator-freezer with a static condenser using the following refrigerants: R12, R500, R12/Dimethyl-ether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12 /DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants indicating a higher capacity. While the R134a and R22/R142b results were less promising refrigeration system, such as a different capillary tube or compressor, may improve their performance. 12 refs., 2 figs., 3 tabs.

Vineyard, E.A.; Sand, J.R.; Miller, W.A.

1989-01-01T23:59:59.000Z

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

Chapter 3: Refrigeration Process Control: Case Study Model 42 33.. RREEFFRRIIGGEERRAATTIIOONN PPRROOCCEESSSS  

E-Print Network [OSTI]

compressor driven by a steam turbine. The fraction of the refrigerant that flows around the second the compressor turbine. A forced draft air cooler is used to condense the HP refrigerant vapour, followed TP1o TP2o TP1i TP2i Turbine Compressor 1 Compressor 2 Condenser Receiver Process Stream 1 Process

Skogestad, Sigurd

422

Heat extracted from the long term flow test in the Fenton Hill HDR reservoir  

SciTech Connect (OSTI)

A long-term flow test was carried out in the Fenton Hill HDR Phase-2 reservoir for 14 months during 1992-1993 to examine the potential for supplying thermal energy at a sustained rate as a commercial demonstration of HDR technology. The test was accomplished in several segments with changes in mean flowrate due to pumping conditions. Re-test estimates of the extractable heat content above a minimum useful temperature were based on physical evidence of the size of the Fenton Hill reservoir. A numerical model was used to estimate the extent of heat extracted during the individual flow segments from the database of measured production data during the test. For a reservoir volume of 6.5x10{sup 6}m{sup 3}, the total heat content above a minimum temperature of 150{degree} C was 1.5x10{sup 15}J. For the total test period at the three sustained mean flowrates, the integrated heat extracted was 0.088x10{sup 15}J, with no discernable temperature decline of the produced fluid. The fraction of energy extracted above the abandonment temperature was 5.9%. On the basis of a constant thermal energy extraction rate, the lifetime of the reservoir (without reservoir growth) to the abandonment temperature would be 13.3 years, in good agreement with the pre-test estimate of 15.0 years for the given reservoir volume.

Kruger, Paul; Robinson, Bruce

1994-01-20T23:59:59.000Z

423

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

424

The refrigerator revolution  

SciTech Connect (OSTI)

This article discusses how a simple, new technology threw the best-laid plans of the chemical and refrigerator industries into disarray-and provided a new perspective on how future environmental agreements can be reached. In recent years, a series of massive business mergers has mesmerized the industrial world. However in the early 1990s a German environmentalist, triggered global reprocussions in the wake of the mandate to phase out the use of ozone depleting substances. The economic and political background of this is explained in detail.

Ayres, E.; French, H.

1996-09-01T23:59:59.000Z

425

Cool energy savings opportunities in commercial refrigeration  

SciTech Connect (OSTI)

The commercial sector consumes over 13 quads of primary energy annually. Most of this consumption (two-thirds) meets the energy needs of lighting and heating, ventilation, and air-conditioning. The largest consuming group of the remaining one-third is commercial refrigeration at about one quad annually (990 trillion Btu), valued at over $7 billion per year to the commercial sector consumer. Potential energy savings are estimated to be about 266 trillion Btu, with consumer savings valued at about $2 billion. This study provides the first known estimates of these values using a bottom-up approach. The authors evaluated numerous self-contained and engineered commercial refrigeration systems in this study, such as: supermarket central systems, beverage merchandisers, ice machines, and vending machines. Typical physical characteristics of each equipment type were identified at the component level for energy consumption. This information was used to form a detailed database from which they arrived at the estimate of 990 trillion Btu energy consumption for the major equipment types used in commercial refrigeration. Based on the implementation of the most cost-effective technology improvements for the seven major equipment types, they estimated an annual potential energy savings of 266 trillion Btu. Much of the savings can be realized with the implementation of high-efficiency fan motors and compressors. In many cases, payback can be realized within three years.

Westphalen, D.; Brodrick, J.; Zogg, R.

1998-07-01T23:59:59.000Z

426

Load Forecasting of Supermarket Refrigeration  

E-Print Network [OSTI]

energy system. Observed refrigeration load and local ambient temperature from a Danish su- permarket renewable energy, is increasing, therefore a flexible energy system is needed. In the present ThesisLoad Forecasting of Supermarket Refrigeration Lisa Buth Rasmussen Kongens Lyngby 2013 M.Sc.-2013

427

Triple effect absorption chiller utilizing two refrigeration circuits  

SciTech Connect (OSTI)

A heat absorption method for an absorption chiller is described comprising: (a) providing a first absorption system circuit for operation within a first temperature range; (b) providing a second absorption system circuit for operation within a second temperature range which has a lower maximum temperature than the first temperature range; (c) heat exchanging refrigerant and absorber solution from the first circuit condenser and absorber with absorption solution from the generator of the second circuit; and (d) the evaporator of the first circuit and the evaporator of the second circuit both being disposed in thermal communication with an external heat load to withdraw heat from the heat load.

De Vault, R.C.

1988-03-22T23:59:59.000Z

428

Malone cycle refrigerator development  

SciTech Connect (OSTI)

This paper describes the progress made in demonstrating a Malone Cycle Refrigerator/Freezer. The Malone cycle is similar to the Stirling cycle but uses a supercritical fluid in place of real gas. In the approach, solid-metal diaphragms are used to seal and sweep the working volumes against the high working fluid pressures required in Malone cycle machines. This feature eliminates the friction and leakage that accounted for nearly half the losses in the best piston-defined Malone cycle machines built to date. The authors successfully built a Malone cycle refrigerator that: (1) used CO{sub 2} as the working fluid, (2) operated at pressures up to 19.3 Mpa (2,800 psi), (3) achieved a cold end metal temperatures of {minus}29 C ({minus}20 F), and (4) produced over 400 Watts of cooling at near ambient temperatures. The critical diaphragm components operated flawlessly throughout characterization and performance testing, supporting the conclusion of high reliability based on analysis of fatigue date and actual strain measurements.

Shimko, M.A.; Crowley, C.J.

1999-07-01T23:59:59.000Z

429

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. 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.

Roach, Patrick R. (Darien, IL); Gray, Kenneth E. (Naperville, IL)

1988-01-01T23:59:59.000Z

430

Isothermally heatsunk diffusion cloud chamber refrigerator  

SciTech Connect (OSTI)

This patent describes a diffusion cloud chamber isothermally heatsunk refrigerator which comprises: a heatsink consisting of two phases of a saturated substance existing in thermodynamic equilibrium at constant pressure and therefore at constant temperature, contained in a reservoir; a means of pressure damping to maintain constant pressure, as the ratio of the two phases present changes and introduces volumetric changes in the substance; a cooling member which transfer heat from vapor in contact with the cooling member surface to the ''cold side'' of a Peltier thermoelectric element with which the cooling member is in thermal contact; a Peltier thermoelectric element which removes the heat supplied by the cooling member from its ''cold side'' and pumps it to the ''hot side'' when driven by an electric current; and a means of transferring heat from the ''hot side'' of the Peltier thermoelectric element to the two-phase isothermal substance in the reservoir.

Menocal, S.G.

1987-05-05T23:59:59.000Z

431

Low Level Heat Recovery Technology  

E-Print Network [OSTI]

level heat recovery technology. This paper discusses heat distribution systems, latest developments in absorption refrigeration and organic Rankine cycles, and pressure, minimization possibilities. The relative merits and economics of the various...

O'Brien, W. J.

1982-01-01T23:59:59.000Z

432

Flow and heat transfer from a continuous surface in a parallel free stream of viscoelastic second-order fluid  

Science Journals Connector (OSTI)

Boundary layer solutions are presented to investigate the steady flow and heat transfer characteristics from a continuous flat surface moving in a parallel free stream of viscoelastic fluid. Numerical results are...

I. A. Hassanien

1992-10-01T23:59:59.000Z

433

FRAC-STIM: A Physics-Based Fracture Simulation, /reservoir Flow and Heat Transport Simulator(aka FALCON)  

Broader source: Energy.gov [DOE]

FRAC-STIM: A Physics-Based Fracture Simulation, /reservoir Flow and Heat Transport Simulator(aka FALCON) presentation at the April 2013 peer review meeting held in Denver, Colorado.

434

Electron Heating by the Ion Cyclotron Instability in Collisionless Accretion Flows. II. Electron Heating Efficiency as a Function of Flow Conditions  

E-Print Network [OSTI]

In the innermost regions of low-luminosity accretion flows, including Sgr A* at the center of our Galaxy, the frequency of Coulomb collisions is so low that the plasma is two-temperature, with the ions substantially hotter than the electrons. This paradigm assumes that Coulomb collisions are the only channel for transferring the ion energy to the electrons. In this work, the second of a series, we assess the efficiency of electron heating by ion velocity-space instabilities in collisionless accretion flows. The instabilities are seeded by the pressure anisotropy induced by magnetic field amplification, coupled to the adiabatic invariance of the particle magnetic moments. Using two-dimensional (2D) particle-in-cell (PIC) simulations, we showed in Paper I that if the electron-to-ion temperature ratio is cyclotron instability is the dominant mode for values of ion beta_i ~ 5-30 (here, beta_i is the ratio of ion thermal pressure to magnetic pressure), as appropriate for the midplane of low-lumin...

Sironi, Lorenzo

2014-01-01T23:59:59.000Z

435

Review of energy efficiency of refrigerator/freezer gaskets. Final report, Jul-Nov 90  

SciTech Connect (OSTI)

The report gives results of an investigation of the significance of heat leakage through gaskets in household refrigerator/freezers, explores different design features, and suggests further study if necessary. The report gives results of an extensive literature review, interviews with refrigerator/freezer and gasket manufacturers, and some engineering analysis. (NOTE: Home refrigerators are the largest consumers of electricity among household appliances and are consuming an estimated 8% of the total electricity used in the U.S. Recent studies show that gasket area heat leakage may account for as much as 21% of the total thermal load.)

Ghassemi, M.; Shapiro, H.

1991-10-01T23:59:59.000Z

436

Convective heat transfer enhancement of laminar flow of latent functionally thermal fluid in a circular tube with constant heat flux: internal heat source model and its application  

Science Journals Connector (OSTI)

This paper analyzes the convective heat transfer enhancement mechanism of latent heat functionally thermal fluid. By using the proposed internal heat source model, the influence of each factor affecting the heat

Yinping Zhang; Xianxu Hu; Qing Hao; Xin Wang

2003-04-01T23:59:59.000Z

437

A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows  

E-Print Network [OSTI]

A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN GREENDYKE Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Aerospace Engineering A PARAMETRIC STUDY OF SHOCK JUMP CHEMISTRY, ELECTRON TEMPERATURE, AND RADIATIVE HEAT TRANSFER MODELS IN HYPERSONIC FLOWS A Thesis by ROBERT BRIAN...

Greendyke, Robert Brian

2012-06-07T23:59:59.000Z

438

Numerical Evaluation of Flow and Heat Transfer in Plate-Pin Fin Heat Sinks with Various Pin Cross-Sections  

E-Print Network [OSTI]

in Table 3. The grid systems for all heat sink models areregion. The grid system for one of the heat sinks is shown

Zhou, Feng; Catton, Ivan

2011-01-01T23:59:59.000Z

439

The flow and heat transfer characteristics of multi-thermal fluid in horizontal wellbore coupled with flow in heavy oil reservoirs  

Science Journals Connector (OSTI)

Abstract As a new improved oil-recovery technique, multi-thermal fluid injection technology through a horizontal well has been widely used in the development process of heavy oil reservoirs. The flow and heat transfer characteristic of multi-thermal fluid in horizontal wellbore is significantly important for the productivity evaluation and parameters design of the horizontal well. Considering the specific physical properties of multi-thermal fluid, fluid absorption in perforation holes and pressure drop characteristics along the horizontal wellbore, this paper developed the flow and heat transfer model of multi-thermal fluid in perforated horizontal wellbore. In order to evaluate the heating effect of the multi-thermal fluid, a concept of effective heating length of a horizontal well is proposed. Then, a sensitivity analysis process is performed to study the influence of reservoir/fluid parameters and operating parameters on the flowing process of multi-thermal fluid in horizontal wellbore. Simultaneously, using the method of orthogonal numerical test, differential analysis and variance analysis are also conducted. Results show that the flowing process of multi-thermal fluid in horizontal wellbore includes a single-phase flowing process and a gasliquid two-phase flowing process. The influence of oil viscosity on the flow and heat transfer characteristics of multi-thermal fluid in horizontal wellbore is most significant. Thereafter, the solution of our semi-analytical model is compared against the test results of an actual horizontal well from an oilfield in China. It is shown that the model results are in good agreement with the real test results. This model could be used to calculate and predict the flow and heat transfer characteristics of multi-thermal fluid (or saturated steam) in a perforated horizontal wellbore.

Xiaohu Dong; Huiqing Liu; Zhaoxiang Zhang; Changjiu Wang

2014-01-01T23:59:59.000Z

440

P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar  

E-Print Network [OSTI]

pieces , electrical contact resistance, material properties, phase changes and heat dissipationi ...) P~!ETRIC STUDY OF HEAT FLOW DURING RESISTANCE SPOT WELDING Euiwhan Kim and Thomas W. Eagar Department of Materials Science and Engineering Hassachusetts Institute of Technology Cambridge, MA 02139

Eagar, Thomas W.

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.


441

page 1 of 4 TkF Vrmeteknik Refrigeration / Kylteknik  

E-Print Network [OSTI]

kJ/kg. a. Calculate the heat of vaporisation of the R-40 at 30°C and -20°C, and calculate with methylchloride (CH3Cl, R-40) as refrigerant. The evaporator operates at Te = -20 °C and exchanges heat-1), closing the cycle. The following data is given for these states: T °C p bar h kJ/kg s kJ/(kg·K) 1 -20 1

Zevenhoven, Ron

442

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

443

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

444

Synopsis of residential refrigerator/freezer alternative refrigerants evaluation  

SciTech Connect (OSTI)

The experimental testing on residential refrigerator/freezers (R/Fs) is summarized in this paper. R/F testing focused on two areas: alternative refrigerants and equipment configurations. The refrigerants evaluated consisted of single components, azeotropes, and zeotropes derived from hydrofluorocarbons (HFCs) and hydrocarbons (HCs). These refrigerants were evaluated in conventional and unconventional R/F designs. Major and minor design modifications were studied. Minor modifications consisted of various capillary tube lengths, door insulations, and compressors, while major modifications included two-evaporator and two-cycle R/F systems. Results obtained from testing the two-cycle system will be discussed in a later paper. This paper presents the experimental results of alternative technologies evaluated as replacements for ozone depleting chemicals.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States)

1998-12-31T23:59:59.000Z

445

Micro-canonical thermodynamics: Why does heat flow from hot to cold  

E-Print Network [OSTI]

We show how to use a central limit approximation for additive co-cycles to describe non-equilibrium and far from equilibrium thermodynamic behavior. We consider first two weakly coupled Hamiltonian dynamical systems initially at different micro-canonical temperatures. We describe a stochastic model where the energy-transfer between the two systems is considered as a random variable satisfying a central limit approximation. We show that fluctuations in energy observables are linearly related to the heat-transfer (dissipation). As a result, on average, heat flows from hot to cold. We also consider the far from equilibrium situation of a non-Hamiltonian thermostatted system as in Evans et al. {\\em Phys.\\ Rev.\\ Lett.} {\\bf 71}, 2401 (1993). Applying the same central limit approximation we re-derive their relation for the violation of the 2nd law of thermodynamics. We note that time-reversal symmetry is not used in our derivation.

Hans Henrik Rugh

2012-04-10T23:59:59.000Z

446

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect (OSTI)

As a result of the Montreal Protocol (UNEP 1987) that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must resolved. Among these are energy impacts, system compatibility, cost, and availability, In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers (AHAM 1985). The results are presented for an 18 ft{sup 3} (0.51 m{sup 3}), top mount refrigerators-freezer with a static condenser using the following refrigerants: R 12, R500, R12/dimethylether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12/DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants, indicating a higher capacity. While the R134a and R22/R142b results were less promising (6.8% and 8.5% higher energy consumption, respectively), changes to the refrigeration system, such as a different capillary tube or compressor, may improve their performance. It is noted that the test results are only an initial step in determining a replacement for R12.

Sand, J.R. (Oak Ridge National Lab., Oak Ridge, TN (US)); Vineyard, E.A.; Sand, J.R.

1989-01-01T23:59:59.000Z

447

On the calculation of flow and heat transfer characteristics for CANDU-type 19-rod fuel bundles  

SciTech Connect (OSTI)

A numerical study is reported of flow and heat transfer in a CANDU-type 19 rod fuel bundle. The flow domain of interest includes combinations of trangular, square, and peripheral subchannels. The basic equations of momentum and energy are solved with the standard k--epsilon model of turbulence. Isotropic turbulent viscosity is assumed and no secondary flow is considered for this steady-state, fully developed flow. Detailed velocity and temperature distributions with wall shear stress and Nusselt number distributions are obtained for turbulent flow of Re = 4.35 x 10/sup 4/, 10/sup 5/, 2 x 10/sup 5/, and for laminar flow of Re--2400. Friction factor and heat transfer ceofficients of various subchannels inside the full bundle are compared with those of infinite rod arrays of triangular or square arrangements. The calculated velocity contours of peripheral subchannel agreed reasonably with measured data.

Yuh-Shan Yueh; Ching-Chang Chieng

1987-08-01T23:59:59.000Z

448

On the calculation of flow and heat transfer characteristics for CANDU-type 19-rod fuel bundles  

SciTech Connect (OSTI)

A numerical study is reported of flow and heat transfer in a CANDU-type 19 rod fuel bundle. The flow domain of interest includes combinations of triangular, square, and peripheral subchannels. The basic equations of momentum and energy are solved with the standard k-{epsilon} model of turbulence. Isotropic turbulent viscosity is assumed and no secondary flow is considered for this steady-state, fully developed flow. Detailed velocity and temperature distributions with wall shear stress and Nusselt number distributions are obtained for turbulent flow of Re = 4.35 {times} 10{sup 4}, 10{sup 5}, 2 {times} 10{sup 5}, and for laminar flow of Re {approximately} 2,400. Friction factor and heat transfer coefficients of various subchannels inside the full bundle are compared with those of infinite rod arrays of triangular or square arrangements. The calculated velocity contours of peripheral subchannel agreed reasonably with measured data.

Yueh, Yuhshan; Chieng, Chingchang (National Tsing Hua Univ., Hsinchu (Taiwan))

1987-08-01T23:59:59.000Z

449

On numerical simulation of flow, heat transfer and combustion processes in tangentially-fired furnace  

SciTech Connect (OSTI)

In this work, an Eulerian/Lagrangian approach has been employed to investigate numerically flow characteristics, heat transfer and combustion processes inside corner-fired power plant boiler furnace. To avoid pseudo-diffusion that is significant in modeling tangentially-fired furnaces, some attempts have been made at improving the finite-difference scheme. Comparisons have been made between standard {kappa}-{epsilon} model and RNG {kappa}-{epsilon} model. Some new developments on turbulent diffusion of particles are taken into account in an attempt to improve computational accuracy. Finally, temperature deviation is studied numerically so as to gain deeper insight into tangentially fired furnace.

Sun, P.; Fan, J.; Cen, K.

1999-07-01T23:59:59.000Z

450

Heat transfer in the flow of a cold, axisymmetric jet over a hot sphere  

E-Print Network [OSTI]

The heat transfer characteristics of thin film flow over a hot sphere resulting from a cold vertical jet of liquid falling onto the surface has been investigated. The underlying physical features have been illustrated by numerical solutions of high accuracy based on the modified Keller box method. The solutions for film thickness distribution are good agreement with those obtained approximately by using the Pohlhausen integral momentum technique and observed experimentally by using water as working fluid, thus providing a basic confirmation of the validity of the results presented.

Shu, Jian-Jun

2014-01-01T23:59:59.000Z

451

Parallel heat flux and flow acceleration in open field line plasmas with magnetic trapping  

SciTech Connect (OSTI)

The magnetic field strength modulation in a tokamak scrape-off layer (SOL) provides both flux expansion next to the divertor plates and magnetic trapping in a large portion of the SOL. Previously, we have focused on a flux expander with long mean-free-path, motivated by the high temperature and low density edge anticipated for an absorbing boundary enabled by liquid lithium surfaces. Here, the effects of magnetic trapping and a marginal collisionality on parallel heat flux and parallel flow acceleration are examined. The various transport mechanisms are captured by kinetic simulations in a simple but representative mirror-expander geometry. The observed parallel flow acceleration is interpreted and elucidated with a modified Chew-Goldberger-Low model that retains temperature anisotropy and finite collisionality.

Guo, Zehua; Tang, Xian-Zhu; McDevitt, Chris [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2014-10-15T23:59:59.000Z

452

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

SciTech Connect (OSTI)

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

453

Page 1 of 4 Refrigerant Charge Verification: 70F Return Air Requirement  

E-Print Network [OSTI]

by operating the central heating system to preheat the dwelling sufficiently to keep the air temperature above 70°F for the duration of the test, or by using supplemental electric resistance heating devices on for the refrigerant charge test. This preheating is best accomplished by the central heating system, but a plug

454

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

455

MagLab - Dilution Refrigerator  

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

in science. Using a condensationevaporation cycle not unlike that of a kitchen refrigerator, a dil fridge takes 4.2 K liquid helium way down to 1.5 K. The animation below...

456

China Refrigerator Information Label: Specification Development and Potential Impact  

E-Print Network [OSTI]

years. About 20% of refrigerators and freezers sold in 2000energy efficiency of refrigerators and freezers, Directiveof Energy, for refrigerators and freezers are base unit

Fridley, David

2008-01-01T23:59:59.000Z

457

Continued development of a semianalytical solution for two-phase fluid and heat flow in a porous medium  

SciTech Connect (OSTI)

Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.

Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

1991-06-01T23:59:59.000Z

458

On the dynamical Rayleigh-Taylor instability in compressible viscous flows without heat conductivity  

E-Print Network [OSTI]

We investigate the instability of a smooth Rayleigh-Taylor steady-state solution to compressible viscous flows without heat conductivity in the presence of a uniform gravitational field in a bounded domain $\\Omega\\subset{\\mathbb R}^3$ with smooth boundary $\\partial\\Omega$. We show that the steady-state is linearly unstable by constructing a suitable energy functional and exploiting arguments of the modified variational method. Then, based on the constructed linearly unstable solutions and a local well-posedness result of classical solutions to the original nonlinear problem, we further reconstruct the initial data of linearly unstable solutions to be the one of the original nonlinear problem and establish an appropriate energy estimate of Gronwall-type. With the help of the established energy estimate, we show that the steady-state is nonlinearly unstable in the sense of Hadamard by a careful bootstrap argument. As a byproduct of our analysis, we find that the compressibility has no stabilizing effect in the linearized problem for compressible viscous flows without heat conductivity.

Fei Jiang; Song Jiang

2014-03-20T23:59:59.000Z

459

3D numerical simulation on fluid flow and heat transfer characteristics in multistage heat exchanger with slit fins  

Science Journals Connector (OSTI)

In this paper, a numerical investigation is performed for three-stage heat exchangers with plain plate fins and slit ... are arranged in a staggered way, and heat conduction in fins is considered. In order ... av...

W. Q. Tao; Y. P. Cheng; T. S. Lee

2007-11-01T23:59:59.000Z

460

Numerical studies for flow and heat transfer of the Powell-Eyring fluid thin film over an unsteady stretching sheet with internal heat generation using the chebyshev finite difference method  

Science Journals Connector (OSTI)

An analysis is carried out to study the unsteady two-dimensional Powell-Eyring flow and heat transfer to a laminar liquid film from a ... horizontal stretching surface in the presence of internal heat generation....

M. M. Khader; A. M. Megahed

2013-05-01T23:59:59.000Z

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.


461

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

462

Heat transfer and fluid flow in microchannels and nanochannels at high Knudsen number using thermal lattice-Boltzmann method  

Science Journals Connector (OSTI)

The present paper deals with the two-dimensional numerical simulation of gaseous flow and heat transfer in planar microchannel and nanochannel with different wall temperatures in transitional regime 0.1?Kn?1. An atomistic molecular simulation method is used known as thermal lattice-Boltzmann method. The results of simulation are presented in four cases corresponding to the Fourier flow, shear-driven flow (Couette flow), pressure-driven flow (Poiseuille flow), and mixed shearpressure-driven flow in the developing and fully developed regions. The mixed shearpressure-driven flow is divided into two subcases with shear stress and pressure gradient acting in the same and the opposite directions. Normalized temperature and velocity profiles across the channel, distribution of local wall Nusselt number, and friction coefficient are illustrated. Using this method, nonlinear pressure distribution in the streamwise direction, reduction in mass flow rate, Cf?Re, and Nu by increasing the Knudsen number are studied. It is seen that for Couette flow, Nu over the hotter plate is greater than the cooler plate, but for the pressure-driven flow with stationary wall temperature dependency of viscosity and thermal conductivity causes this trend to be reversed. The reversed flow appearance in the velocity profile is captured in the case of opposite shearpressure-driven flow.

J. Ghazanfarian and A. Abbassi

2010-08-13T23:59:59.000Z

463

Pioneering Heat Pump Project  

Broader source: Energy.gov [DOE]

Project objectives: To install and monitor an innovative WaterFurnace geothermal system that is technologically advanced and evolving; To generate hot water heating from a heat pump that uses non-ozone depleting refrigerant CO2. To demonstrate the energy efficiency of this system ground source heat pump system.

464

Countercurrent flow limited (CCFL) heat flux in the high flux isotope reactor (HFIR) fuel element  

SciTech Connect (OSTI)

The countercurrent flow (CCF) performance in the fuel element region of the HFIR is examined experimentally and theoretically. The fuel element consists of two concentric annuli filled with aluminum clad fuel plates of 1.27 mm thickness separated by 1.27 mm flow channels. The plates are curved as they go radially outward to accomplish constant flow channel width and constant metal-to-coolant ratio. A full-scale HFIR fuel element mock-up is studied in an adiabatic air-water CCF experiment. A review of CCF models for narrow channels is presented along with the treatment of CCFs in system of parallel channels. The experimental results are related to the existing models and a mechanistic model for the annular'' CCF in a narrow channel is developed that captures the data trends well. The results of the experiment are used to calculate the CCFL heat flux of the HFIR fuel assembly. It was determined that the HFIR fuel assembly can reject 0.62 Mw of thermal power in the CCFL situation. 31 refs., 17 figs.

Ruggles, A.E.

1990-10-12T23:59:59.000Z

465

Effect of rolling motion on critical heat flux for subcooled flow boiling in vertical tube  

SciTech Connect (OSTI)

This paper presents defining characteristics of the critical heat flux (CHF) for the boiling of R-134a in vertical tube operation under rolling motion in marine reactor. It is important to predict CHF of marine reactor having the rolling motion in order to increase the safety of the reactor. Marine Reactor Moving Simulator (MARMS) tests are conducted to measure the critical heat flux using R-134a flowing upward in a uniformly heated vertical tube under rolling motion. MARMS was rotated by motor and mechanical power transmission gear. The CHF tests were performed in a 9.5 mm I.D. test section with heated length of 1 m. Mass fluxes range from 285 to 1300 kg m{sup -2}s{sup -1}, inlet subcooling from 3 to 38 deg. C and outlet pressures from 13 to 24 bar. Amplitudes of rolling range from 15 to 40 degrees and periods from 6 to 12 sec. To convert the test conditions of CHF test using R-134a in water, Katto's fluid-to-fluid modeling was used in present investigation. A CHF correlation is presented which accounts for the effects of pressure, mass flux, inlet subcooling and rolling angle over all conditions tested. Unlike existing transient CHF experiments, CHF ratio of certain mass flux and pressure are different in rolling motion. For the mass fluxes below 500 kg m{sup -2}s{sup -1} at 13, 16 (region of relative low mass flux), CHF ratio was decreased but was increased above that mass flux (region of relative high mass flux). Moreover, CHF tend to enhance in entire mass flux at 24 bar. (authors)

Hwang, J. S.; Park, I. U.; Park, M. Y.; Park, G. C. [Dept. of Energy Systems Engineering, Seoul National Univ., 599 Gwanak-Ro, Gwanak-Gu, Seoul, 151-744 (Korea, Republic of)

2012-07-01T23:59:59.000Z

466

Numerical study of fluid flow and heat transfer characteristics inanintermittent turbulent impinging round jet  

Science Journals Connector (OSTI)

Abstract The flow structure and heat transfer of the air pulsed turbulent impinging jet are studied numerically. The gas turbulence is modelled with the Reynolds stress model. The effects of pulse frequency, ratio of on time to total cycle time, distance between pipe outlet and impinging flat plate and Reynolds number on heat transfer are numerically studied. The impingement heat transfer increases with distance from the pipe edge and target surface. The heat transfer decreases at high distance from the pipe edge and target surface. An increase in the Reynolds number causes reduction of heat transfer enhancement. Reduced heat transfer in comparison with the steady-state impinging jet is typical in the range of low frequencies of the pulse impinging jet.

M.A. Pakhomov; V.I. Terekhov

2015-01-01T23:59:59.000Z

467

Refrigerator-Freezer Appendix A1 | Department of Energy  

Energy Savers [EERE]

Refrigerator-Freezer Appendix A1 Refrigerator-Freezer Appendix A1 Residential Refrigerator-Freezer Appendix A1 - v2.8.xlsx More Documents & Publications Refrigerators and...

468

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)

469

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

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

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

470

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

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

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

471

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

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

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

472

Assessment of gas-fired commercial refrigeration. Final report Mar-Aug 1982  

SciTech Connect (OSTI)

Gas-fired commercial refrigeration is not common today. However, today's and tomorrow's gas engines (internal combustion, Stirling, gas turbines) could power cost-effective refrigeration systems. One key is effectively utilizing the prime mover's reject heat to economic advantage. Another is the capacity control afforded by a variable-speed prime mover. The best example of such a system is comparatively near-term. It serves the large and steady supermarket refrigeration market with an industrial-grade internal combustion engine driving an open-shaft reciprocating compressor. The gas engine's exhaust enables a reciprocating steam engine to boost shaft power by 20%.

Hynek, S.J.; Krepchin, I.P.; Harvey, A.C.; Demler, R.L.; Borhanian, H.H.

1983-02-01T23:59:59.000Z

473

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

474

China Refrigerator Information Label: Specification Development and Potential Impact  

E-Print Network [OSTI]

Household Refrigerator Market and Energy Conservation Regulations in Japan.Household Refrigerator Market and Energy Conservation Regulations in Japan

Fridley, David

2008-01-01T23:59:59.000Z

475

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

476

LATERAL HEAT FLOW INFRARED THERMOGRAPHY FOR THICKNESS INDEPENDENT DETERMINATION OF THERMAL DIFFUSIVITY IN CFRP  

SciTech Connect (OSTI)

In conventional infrared thermography, determination of thermal diffusivity requires thickness information. Recently GE has been experimenting with the use of lateral heat flow to determine thermal diffusivity without thickness information. This work builds on previous work at NASA Langley and Wayne State University but we incorporate thermal time of flight (tof) analysis rather than curve fitting to obtain quantitative information. We have developed appropriate theoretical models and a tof based data analysis framework to experimentally determine all components of thermal diffusivity from the time-temperature measurements. Initial validation was carried out using finite difference simulations. Experimental validation was done using anisotropic carbon fiber reinforced polymer (CFRP) composites. We found that in the CFRP samples used, the in-plane component of diffusivity is about eight times larger than the through-thickness component.

Tralshawala, Nilesh; Howard, Don; Knight, Bryon; Plotnikov, Yuri; Ringermacher, Harry [Nondestructive Technologies Laboratory, GE--Global Research Center, Niskayuna, NY 12309 (United States)

2008-02-28T23:59:59.000Z

477

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

478

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 (more)

Rodriguez, Angel Gerardo

2012-01-01T23:59:59.000Z

479

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

480

Cospolich Refrigerator: Order (2013-CE-5314)  

Broader source: Energy.gov [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.

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.


481

Refrigerator Manufacturers: Order (2013-CE-5341)  

Broader source: Energy.gov [DOE]

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

482

International Refrigeration: Order (2012-CE-1510)  

Broader source: Energy.gov [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.

483

Numerical analysis of convective heat transfer characteristics of supercritical hydrocarbon fuel in cooling panel with local flow blockage structure  

Science Journals Connector (OSTI)

Abstract The convection heat transfer of hydrocarbon fuel at supercritical pressure has a great influence on the regenerative cooling technology of a scramjet engine. A three-dimensional numerical simulation was conducted for the convection transfer of hydrocarbon fuel in the cooling panel of a combustion chamber wall. And the flow field around the local flow blockage structure and the outlet flow rate distribution characteristics of fuel in the cooling channels were analyzed in detail. The results of analyses indicate that with the optimized local flow blockage structure, the outlet flow rate distribution of fuel among the cooling channels become more uniform, as the area of local flow dead zone decreases. However, as the fuel temperature increases, the dramatic variation of thermodynamic physical properties of fuel has a strong influence on the flow field around the local flow blockage structure. Especially, a local flow dead zone can be easily formed in the supercritical temperature region. Meanwhile, transverse pressure gradient around the throat region of blockage structure and additional loss, which is caused by turbulence fluctuation and energy exchange of fluid in the downstream area, affect the outlet flow rate distribution of fuel among the coolant passages seriously. It can therefore be concluded that the local flow blockage structure is more suitably designed in the subcritical temperature region by taking above-mentioned factors into consideration.

Yu Feng; Jiang Qin; Wen Bao; Qinchun Yang; Hongyan Huang; Zhongqi Wang

2014-01-01T23:59:59.000Z

484

Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel  

E-Print Network [OSTI]

COMMANDS . . APPENDIX C: UNCERTAINTY ANALYSIS . APPENDIX D: RAW DATA & RESULTS . . 71 . . . . 74 77 VITA. 134 vu1 LIST OF FIGURES Page Figurc 1 Internal and external cooling concepts used in modem gas turbine airfoils (Han et al. ). Figure 2... . . . . . . . . . . . . . . . . . . . . . . . . . 62 xt NOMENCLATURE A, flow cross-sectional area of test channel, m 2 surface area, m 2 D?hydraulic diameter of test channel, m friction factor f, reference friction factor for fully developed turbulent flow in smooth channel heat transfer...

Cervantes, Joel

2012-06-07T23:59:59.000Z

485

Synthesis of Cascade Refrigeration and Liquefaction Systems  

Science Journals Connector (OSTI)

Synthesis of Cascade Refrigeration and Liquefaction Systems ... Current Status and Perspectives of Liquefied Natural Gas (LNG) Plant Design ...

Francisco J. Barns; C. Judson King

1974-10-01T23:59:59.000Z

486

Interactive Synthesis of Cascade Refrigeration Systems  

Science Journals Connector (OSTI)

Interactive Synthesis of Cascade Refrigeration Systems ... Current Status and Perspectives of Liquefied Natural Gas (LNG) Plant Design ...

Wai Biu Cheng; Richard S. H. Mah

1980-07-01T23:59:59.000Z

487

Dry dilution refrigerator with He-4 precool loop  

SciTech Connect (OSTI)

He-3/He-4 dilution refrigerators (DR) are very common in sub-Kelvin temperature research. We describe a pulse tube precooled DR where a separate He-4 circuit condenses the He-3 of the dilution loop. Whereas in our previous work the dilution circuit and the He-4 circuit were separate, we show how the two circuits can be combined. Originally, the He-4 loop with a base temperature of ? 1 K was installed to make an additional cooling power of up to 100 mW available to cool cold amplifiers and electrical lines. In the new design, the dilution circuit is run through a heat exchanger in the vessel of the He-4 circuit so condensation of the He-3 stream of the DR is done by the He-4 stage. A much reduced condensation time (factor of 2) of the He-3/He-4 gas mixture at the beginning of an experiment is achieved. A compressor is no longer needed with the DR as the condensation pressure remains below atmospheric pressure at all times; thus the risk of losing expensive He-3 gas is small. The performance of the DR has been improved compared to previous work: The base temperature of the mixing chamber at a small He-3 flow rate is now 4.1 mK; at the highest He-3 flow rate of 1.2 mmol/s this temperature increases to 13 mK. Mixing chamber temperatures were measured with a cerium magnesium nitrate (CMN) thermometer which was calibrated with a superconducting fixed point device.

Uhlig, Kurt [Walther-Meissner-Institute, 85748 Garching (Germany)

2014-01-29T23:59:59.000Z

488

Wheel-type magnetic refrigerator  

DOE Patents [OSTI]

The disclosure is directed to a wheel-type magnetic refrigerator capable of cooling over a large temperature range. Ferromagnetic or paramagnetic porous materials are layered circumferentially according to their Curie temperature. The innermost layer has the lowest Curie temperature and the outermost layer has the highest Curie temperature. The wheel is rotated through a magnetic field perpendicular to the axis of the wheel and parallel to its direction of rotation. A fluid is pumped through portions of the layers using inner and outer manifolds to achieve refrigeration of a thermal load. 7 figs.

Barclay, J.A.

1983-10-11T23:59:59.000Z

489

Refrigerator and Solenoid Run Summary August/September 1999  

SciTech Connect (OSTI)

The helium refrigerator was cooled down and operated for the third time since its installation. D-Zero's 2 Tesla superconducting solenoid was cooled down and operated for its second time since its installation into the D-Zero detector. This engineering note summarizes the cryogenic aspects of the test run and performance measurements made. The main purpose of this run was to do field mapping of the solenoid with different combinations of field polarity on the Solenoid and CF iron magnets. This was accomplished. A second purpose was to test the lower field joint repair that was done in January 1999. This field joint had a measurable voltage drop across the soldered bus splice. The repair was an undoing of the joint, extensive cleaning of the bus, and then welding the splice. The repair was successful, no voltage drop was measured and the magnet behaved nicely. A parasitic purpose was to get some operating time on the refrigerator, measure the refrigeration performance, and measure the heat leak in the VLPC lines mounted on the detector platform. Refrigerator performance was spot checked, and was found to be 60 watts (10%) less than generic operating curves. At this level of performance, the operating margin for the full solenoid and VLPC system will be 75 watts (15%) which is somewhat uncomfortable from an operational stand point. The VLPC lines were operated and heat leak numbers of around 40 watts was measured for each pipe section including the supply u-tubes to the detector, the bayonet can, valve box on the platform and the piping back to the refrigerator valve box. Another purpose of the test run was to test the compatibility of other detector components with the new central magnetic field environment. I do not know the results of these tests.

Rucinski, R.; /Fermilab

1999-09-20T23:59:59.000Z

490

Heat pump having improved defrost system  

DOE Patents [OSTI]

A heat pump system includes, in an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant: a compressor; an interior heat exchanger; an exterior heat exchanger; an accumulator; and means for heating the accumulator in order to defrost the exterior heat exchanger. 2 figs.

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

1998-12-08T23:59:59.000Z

491

Comparison of Several Eco-Friendly Refrigeration Technologies  

E-Print Network [OSTI]

The mechanism of adsorption refrigeration is shown in Fig 1. The adsorption system is sealed, when adsorbent filled in adsorber is heated, adsorbate adsorbed in adsorbent gains energy. When molecule movement rate of adsorbate is enough to overcome affinity... between adsorbate and adsorbent, adsorbate will be desorbed. When sub-pressure of the system gradually increasing reaches the value of saturation steam pressure corresponding to environmental temperature, adsorbate desorbed from adsorbent...

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

2006-01-01T23:59:59.000Z

492

Simple thermodynamic diagrams for real refrigeration systems  

Science Journals Connector (OSTI)

The thermodynamic performance of real irreversible cooling and refrigeration systems (chillers) can be summarized in simple rectangular temperature-entropy diagrams in analogy to classic pedagogical examples for idealized reversible devices. The key to translating complex dissipative losses into this graphical framework is the process average temperaturea factor that can be calculated from nonintrusive experimental measurements for converting entropy production into lost work. An uncomplicated thermodynamic model is used to transform the governing chiller performance equations into an easily-interpreted graph. Examples based upon actual data from commercial work-driven (reciprocating) and heat-driven (absorption) chillers are presented and are used to highlight the predominance of internal dissipation in determining chiller efficiency. With the thermodynamic diagram representation the relative roles of each irreversibility source as well as the reversible and endoreversible limits become transparent.

J. M. Gordon; K. C. Ng; H. T. Chua

1999-01-01T23:59:59.000Z

493

Double layer created by electron cyclotron resonance heating in an inhomogeneously magnetized plasma with high-speed ion flow  

SciTech Connect (OSTI)

A potential jump, i.e., an electric double layer (DL) is formed near an electron cyclotron resonance (ECR) point when an electron cyclotron wave is injected into an inhomogeneously magnetized plasma with high-speed ion flow. A charge separation is caused by an electron reflection due to -{mu}{nabla}B{sub z} force enhanced by ECR heating and ion inertia. It is clearly demonstrated in the experiment that the potential height of the DL is almost proportional to the field-aligned ion flow energy; the DL is found to be self-consistently formed for maintaining charge neutrality by reflecting a part of the flowing ions.

Takahashi, K.; Kaneko, T.; Hatakeyama, R. [Department of Electronic Engineering, Tohoku University, Sendai, 980-8579 (Japan)

2008-07-15T23:59:59.000Z

494

Heat transfer in channels with porous inserts during forced fluid flow  

Science Journals Connector (OSTI)

General analytic expressions are obtained to calculate heat transfer and temperature fields in a plane channel ... allowance for the effective thermal conductivity of the heat carrier and the distribution of heat

A. A. Plakseev; V. V. Kharitonov

1989-01-01T23:59:59.000Z

495

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

E-Print Network [OSTI]

necessary fluid mechanical and heat transfer data forCurvature on Heat Transfer to Incompressible Fluids," Trans.may transfer as much or more heat (to a moving fluid in

Yee, G.

2010-01-01T23:59:59.000Z

496

Research Positionsfor Development of Novel Green Air Conditioning and Refrigeration Systems for Transportation Vehicles  

E-Print Network [OSTI]

in refrigeration and heat pump systems, HVAC, porous media development/characterization, transport phenomena of compact and lightweight heat exchangers for evaporator and condenser; v) Development of heatdriven adsorption chillers tailored to service vehicles; vi) Development and implementation of thermal energy

Bahrami, Majid

497

Energy consumption testing of innovative refrigerator-freezers  

SciTech Connect (OSTI)

The high ambient temperature of the Canadian Standards Association (CSA) and the AHAM/DOE Refrigerator-Freezer Energy Consumption Standards is intended to compensate for the lack of door openings and other heat loads. Recently published results by Meier and Jansky (1993) indicate labeled consumption overpredicting typical field consumption by 15%. In-house field studies on conventional models showed labeled consumption overpredicting by about 22%. The Refrigerator-Freezer Technology Assessment (RFTA) test was developed to more accurately predict field consumption. This test has ambient temperature and humidity, door openings, and condensation control set at levels intended to typify Canadian household conditions. It also assesses consumption at exactly defined compartment rating temperatures. Ten conventional and energy-efficient production models were laboratory tested. The RFTA results were about 30% lower than labeled. Similarly, the four innovative refrigerator-freezer models, when field tested, also had an average of 30% lower consumption than labeled. Thus, the results of the limited testing suggest that the RFTA test may be a more accurate predictor of field use. Further testing with a larger sample is recommended. Experimental results also indicated that some innovative models could save up to 50% of the energy consumption compared with similar conventional units. The technologies that contributed to this performance included dual compressors, more efficient compressors and fan motors, off-state refrigerant control valve, fuzzy logic control, and thicker insulation. The larger savings were on limited production models, for which additional production engineering is required for full marketability.

Wong, M.T.; Howell, B.T.; Jones, W.R. [Ontario Hydro Technologies, Toronto, Ontario (Canada); Long, D.L. [Statistical Solutions, Mississauga, Ontario (Canada)

1995-12-31T23:59:59.000Z

498

Dry dilution refrigerator with 4He-1K-loop  

E-Print Network [OSTI]

In this article we summarize experimental work on cryogen-free 3He/4He dilution refrigerators which, in addition to the dilution refrigeration circuit, are equipped with a 4He-1K-stage. This type of DR becomes worth considering when high cooling capacities are needed at T ~ 1 K to cool cold amplifiers and heat sink cables. In our application, the motivation for the construction of this type of cryostat was to do experiments on superconducting quantum circuits for quantum information technology and quantum simulations. In other work, DRs with 1K-stage were proposed for astro-physical cryostats. For neutron scattering research, a top-loading cryogen-free DR with 1K-stage was built which was equipped with a standard commercial dilution refrigeration insert. Cooling powers of up to 100 mW have been reached with our 1K-stage, but higher refrigeration powers were achieved with more powerful pulse tube cryocoolers and higher 4He circulation rates in the 1K-loop. Several different versions of a 1K-loop have been test...

Uhlig, Kurt

2014-01-01T23:59:59.000Z

499

Simulating effects of multispeed compressors on refrigerator/freezer performance  

SciTech Connect (OSTI)

Simulation analyses suggest that a multispeed compressor could increase steady-state operating efficiency by 4% to 14%. An additional 0.5% to 4% energy savings might be obtained from the reduction in the cycling frequency of the refrigerator. Several aspects of the robustness of the capillary tube-suction line heat exchanger design for the two-speed compressor system were also examined with the simulation model. It was shown that a system optimized for low-speed operation, when operating at the high speed, could have as much capacity as the original base case high-speed system. A relatively simple control strategy was proposed, one that requires measurement of on-cycle time and one or two compartment air temperatures. The effects of varying the speed of the evaporator or condenser fans at both compressor speeds were examined over a range of ambient temperatures. One energy-saving scenario was identified: decreasing the condenser fan speed for refrigerators operating at low ambient temperatures. By affecting the distribution of refrigerant change throughout the system, the decrease in condenser fan speed reduces the superheat in the evaporator and increases the overall UA of the evaporator. The resulting increase in evaporator capacity more than offsets the decrease in condenser UA and the energy use of the refrigerator is decreased.

Woodall, R.J. [International Paper Technology, Mobile, AL (United States); Bullard, C.W. [Univ. of Illinois, Urbana, IL (United States). Air Conditioning and Refrigeration Center

1997-12-31T23:59:59.000Z

500

Standard Method of Test for Integrated Heat Pumps  

Broader source: Energy.gov [DOE]

Lead Performer: Oak Ridge National Laboratory - Oak Ridge, TN Partners: -- ASHRAE - Atlanta, GA -- Air Conditioning, Heating, and Refrigeration Institute (AHRI) - Arlington, VA