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Note: This page contains sample records for the topic "modeling variable refrigerant" 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

A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus  

SciTech Connect

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

Raustad, Richard A. [Florida Solar Energy Center

2013-01-01T23:59:59.000Z

2

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

SciTech Connect

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

Sharma, Chandan; Raustad, Richard

2013-06-01T23:59:59.000Z

3

Modeling supermarket refrigeration energy use and demand  

SciTech Connect

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

4

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

5

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

SciTech Connect

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

6

Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency  

E-Print Network (OSTI)

The application of the variable refrigerant volume multi-zone air conditioning systems has met with mixed results since the publication of the Design Standard for Energy Efficiency of Public Buildings. This paper analyzes the characteristics...

Zhu, H.

2006-01-01T23:59:59.000Z

7

Modeling Supermarket Refrigeration Systems with EnergyPlus  

SciTech Connect

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

8

Supermarket refrigeration modeling and field demonstration: Interim report  

SciTech Connect

The Electric Power Research Institute (EPRI) has undertaken a project to investigate supermarket refrigeration. The objectives of this project are (1) to develop an energy use and demand model of supermarket refrigeration systems and (2) to carry out an extensive field test of such systems in an operating supermarket. To accomplish these goals, a supermarket owned by Safeway Stores, Inc., and located in Menlo Park, CA, with an existing conventional refrigeration system utilizing single compressor units, was equipped with a state-of-the-art system with multiplexed parallel compressors. The store and both refrigeration systems were thoroughly instrumented and a test schedule was prepared and executed. Presented in this report are the preliminary results of this field test along with the initial validation of the energy use and demand model. 62 figs., 47 tabs.

Walker, D.H.; Deming, G.I.

1989-03-01T23:59:59.000Z

9

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

E-Print Network (OSTI)

Comfort by Design An Introduction to HVAC’s 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

10

Control of household refrigerators. Part 1: Modeling temperature control performance  

SciTech Connect

Commercial household refrigerators use simple, cost-effective, temperature controllers to obtain acceptable control. A manually adjusted airflow damper regulates the freezer compartment temperature while a thermostat controls operation of the compressor and evaporator fan to regulate refrigerator compartment temperature. Dual compartment temperature control can be achieved with automatic airflow dampers that function independently of the compressor and evaporator fan thermostat, resulting in improved temperature control quality and energy consumption. Under dual control, freezer temperature is controlled by the thermostat while the damper controls refrigerator temperature by regulating airflow circulation. A simulation model is presented that analyzes a household refrigerator configured with a conventional thermostat and both manual and automatic dampers. The model provides a new paradigm for investigating refrigerator systems and temperature control performance relative to the extensive verification testing that is typically done by manufacturers. The effects of each type of control and damper configuration are compared with respect to energy usage, control quality, and ambient temperature shift criteria. The results indicate that the appropriate control configuration can have significant effects and can improve plant performance.

Graviss, K.J.; Collins, R.L.

1999-07-01T23:59:59.000Z

11

Chapter 4: Refrigeration Process Control: Simulation Model 64 44.. RREEFFRRIIGGEERRAATTIIOONN PPRROOCCEESSSS  

E-Print Network (OSTI)

Chapter 4: Refrigeration Process Control: Simulation Model 64 44.. RREEFFRRIIGGEERRAATTIIOONN of the simulation model for the two-stage refrigeration system is presented. The model is based on the mathematical, it is #12;Chapter 4: Refrigeration Process Control: Simulation Model 65 translated into FORTRAN or C

Skogestad, Sigurd

12

A simple computational model for Stirling cycle refrigerators  

SciTech Connect

This paper presents a simple computational model for an Alpha Free-Pistons Stirling refrigerator. The model assumes isothermal workspaces, where the compression space is maintained at temperature TH, while the expansion space is maintained at temperature TL. The regenerator is assumed to have a linear temperature distribution along its axial direction, with the working fluid taken as an ideal gas. This model is based on a control volume type analysis in which each of the components of the refrigerator (the regenerator and each of the two workspaces) is considered a separate control volume. Moving the compression piston in a predetermined sinusoidal motion provides the work input to the cycle. The motion of the compression space piston generates a pressure difference across the refrigerator, and forces the working fluid to pass through the regenerator. The expansion piston responds to the pressure in its workspace according to Newton's second law of motion. In this way the dynamics of the moving pistons will be coupled to the thermodynamics of the refrigerator system. Conservation laws of mass, momentum and energy along with ideal gas relations are used to form a set of differential and algebraic equations fully describing the refrigerator system. The motion of the expansion piston, the state of the working fluid at each workspace, and the energy terms appearing in the definition of the COP, can all be obtained. A marching-in-time technique with a Runge-Kutta scheme of the fourth order is adapted to integrate the equation of motion of the expansion piston. System behavior can be represented by the motion of the two pistons with time, and also by the pressure-volume diagrams of the workspaces. The COP plots can be produced from the computational results to describe the performance of the refrigerator.

Al-Hazmy, M.M.; Peterson, R.B.

1998-07-01T23:59:59.000Z

13

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

14

Fast Nonconvex Model Predictive Control for Commercial Refrigeration  

E-Print Network (OSTI)

its capabil- ity to minimize the total cost of energy for a commercial refrigeration system while multi-zone refrigeration system, consisting of several cooling units that share a common compressor. This corresponds roughly to 2% of the entire electricity consumption in the country. Refrigerated goods constitute

15

Neural modeling of vapor compression refrigeration cycle with extreme learning machine  

Science Journals Connector (OSTI)

In this paper, a single-hidden layer feed-forward neural network (SLFN) is used to model the dynamics of the vapor compression cycle in refrigeration and air-conditioning systems, based on the extreme learning machine (ELM). It is shown that the assignment ... Keywords: Back propagation, Extreme learning machine, Modeling, Radial basis function, Support vector regression, Vapor compression refrigeration cycle

Lei Zhao; Wen-Jian Cai; Zhi-Hong Man

2014-03-01T23:59:59.000Z

16

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

17

Field demonstration of optimized variable speed compressor and condenser fan control for commercial refrigeration systems. Final report  

SciTech Connect

The demonstration project discussed in this report consisted of two separate programs intended to examine methods of implementing variable-frequency drives (VFDs) to increase the efficiency of supermarket refrigeration racks. The first program examined the optimum control strategy for minimizing the power consumption of medium-temperature parallel compressor racks driven by VFDs. The second program, aimed at developing the optimum control strategy for variable-speed control of supermarket condenser fans.

NONE

1997-11-01T23:59:59.000Z

18

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

19

Modelling and transient simulation of CO2-refrigeration systems with Modelica  

Science Journals Connector (OSTI)

This paper presents the current results of the development of a Modelica library for CO2-refrigeration systems based on the free Modelica library ThermoFluid. The development of the library is carried out in a research project of Airbus Deutschland and the TUHH and is focused on the aim to obtain a library for detailed numerical investigations of refrigeration systems with the rediscovered refrigerant carbon dioxide (CO2). A survey of the concept of an integrated on-board cooling system of airliners, the modelling language Modelica™ and the CO2-library is given and the modelling of CO2-heat exchangers is described. A comparison with steady state results of heat exchangers shows a fair agreement. The presented transient simulation results are compared with experimental data showing also a fair agreement.

Torge Pfafferott; Gerhard Schmitz

2004-01-01T23:59:59.000Z

20

Engineering computer models for refrigerators, freezers, furnaces, water heaters, room and central air conditioners  

SciTech Connect

This User's Guide provides the necessary information for understanding and using a computer model developed for the US Department of Energy which predicts the performance (energy consumption) of household refrigerators, refrigerator-freezers, and freezers. The model is capable of simulating various cabinet configurations (top-mount, bottom-mount, side-by-side, single-door) and refrigeration unit combinations (back-mounted static condenser with single forced convection evaporator, hot wall condenser with cooled wall panels, etc.). The program is comprised of two main subroutines: a cabinet heat-load submodel and a refrigeration unit submodel; they can be used separately for preliminary design analysis or together for performance evaluations. A technical description of the model and information on how to structure input parameters are provided. The user is provided with specific guidance for running the model on a computer. Specific instructions are given in the Appendices for changing and running the model using the operating language compatible with the DOE computer terminal system. Other users will have to modify the procedures in these sections as necessary for different computers.

Not Available

1982-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

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

22

90.1 Prototype Building Models Warehouse (non-refrigerated) | Building  

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

Warehouse (non-refrigerated) Warehouse (non-refrigerated) The ASHRAE Standard 90.1 prototype building models were developed by Pacific Northwest National Laboratory in support of the U.S. Department of Energy's (DOE's) Building Energy Codes Program. These prototype buildings were derived from DOE's Commercial Reference Building Models. This suite of ASHRAE Standard 90.1 prototype buildings covers all the Reference Building types except supermarket, and also adds a new building prototype representing high-rise apartment buildings.The prototype models include 16 building types in 17 climate locations for ASHRAE Standards 90.1-2004, 90.1-2007 and 90.1-2010. This combination leads to a set of 816 building models (in EnergyPlus Version 6.0). Also included is a scorecard for each prototype building. The scorecard is a spreadsheet that summarizes the

23

Cascade and secondary coolant supermarket refrigeration systems : modelling and new frost correlations.  

E-Print Network (OSTI)

??Nowadays traditional (direct expansion) supermarket refrigeration systems are mostly employed in supermarket establishments for refrigerating food products and beverages in the store. However, the installations… (more)

Haile-Michael, Getu

2011-01-01T23:59:59.000Z

24

Modeling of Solar-Powered Single-Effect Absorption Cooling System and Supermarket Refrigeration/HVAC System.  

E-Print Network (OSTI)

??This thesis consists of two different research problems. In the first one, the aim is to model and simulate a solar-powered, single-effect, absorption refrigeration system… (more)

Bahman, Ammar

2011-01-01T23:59:59.000Z

25

Modeling of Solar-Powered Single-Effect Absorption Cooling System and Supermarket Refrigeration/HVAC System.  

E-Print Network (OSTI)

?? This thesis consists of two different research problems. In the first one, the aim is to model and simulate a solar-powered, single-effect, absorption refrigeration… (more)

Bahman, Ammar Mohammad Khalil

2011-01-01T23:59:59.000Z

26

Modeling the dynamic response of pressures in a distributed helium refrigeration system  

SciTech Connect

A mathematical model is created of the dynamic response of pressures caused by flow inputs to an existing distributed helium refrigeration system. The dynamic system studied consists of the suction and discharge pressure headers and compressor portions of the refrigeration system used to cool the superconducting magnets of the Tevatron accelerator at the Fermi National Accelerator Laboratory. The modeling method involves identifying the system from data recorded during a series of controlled tests, with effort made to detect locational differences in pressure response around the four mile accelerator circumference. A review of the fluid mechanics associated with the system indicates linear time invariant models are suitable for the identification, particularly since the governing equations of one dimensional fluid flow are approximated by linear differential equations. An outline of the experimental design and the data acquisition system are given, followed by a detailed description of the modeling, which utilized the Matlab programming language and associated System Identification Toolbox. Two representations of the system are presented. One, a black box model, provides a multi-input, multi-output description assembled from the results of single input step function testing. This description indicates definite variation in pressure response with distance from the flow input location, and also suggests subtle differences in response with the input location itself. A second system representation is proposed which details the relation between continuous flow changes and pressure response, and provides explanation of a previously unappreciated pressure feedback internal to the system.

Brubaker, J.C.

1997-12-01T23:59:59.000Z

27

Cosmological models with variable constants  

E-Print Network (OSTI)

The behavior of the constants, G,c,h,a,e,m and Lambda, considering them as variable, in the framework of a flat cosmological model with FRW symmetries described by a bulk viscous fluid and considering mechanisms of adiabatic matter creation are investigated. Within two models; one with radiation predominance and another of matter predominance, this behavior are studied.

J. A. Belinchon

1999-07-01T23:59:59.000Z

28

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

29

Variable Refrigerant Flow Systems  

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

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

30

Variable Refrigerant Flow HVAC  

E-Print Network (OSTI)

Conference, San Antonio, Texas Dec. 16-18 What do they know that we don’t 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

31

Dynamic Modeling and Cascaded Control for a Multi-Evaporator Supermarket Refrigeration System.  

E-Print Network (OSTI)

??The survey from US Department of Energy showed that about one-third of energy consumption in US is due to air conditioning and refrigeration systems. This… (more)

Gupta, Ankush 1986-

2012-01-01T23:59:59.000Z

32

Duracold Refrigeration Manufacturing: Order (2013-CE-5342) | Department of  

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

Duracold Refrigeration Manufacturing: Order (2013-CE-5342) Duracold Refrigeration Manufacturing: Order (2013-CE-5342) Duracold Refrigeration Manufacturing: Order (2013-CE-5342) April 25, 2013 DOE ordered Duracold Refrigeration Manufacturing Company, LLC to pay a $8,000 civil penalty after finding Duracold Refrigeration Manufacturing had failed to certify that certain models of walk-in cooler and freezer components comply with the applicable energy conservation standards. The Order adopted a Compromise Agreement, which reflected settlement terms between DOE and Duracold Refrigeration Manufacturing. Duracold Refrigeration Manufacturing: Order (2013-CE-5342) More Documents & Publications Duracold Refrigeration Manufacturing: Proposed Penalty (2013-CE-5342) North Star Refrigerator: Order (2013-CE-5355) Schott Gemtron: Order (2013-CE-5358

33

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

34

Requirements for Determining Refrigerant Charge Residential Air Conditioning Measures  

E-Print Network (OSTI)

Requirements for Determining Refrigerant Charge Residential Air Conditioning Measures Improved Refrigerant Charge Purpose Component packages require in some climate zones that split system air refrigerant charge. For the performance method, the proposed design is modeled with less efficiency

35

Cospolich Refrigerator: Order (2013-CE-5314)  

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

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

36

Refrigerator Manufacturers: Order (2013-CE-5341)  

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

37

Dynamic Modeling and Cascaded Control for a Multi-Evaporator Supermarket Refrigeration System  

E-Print Network (OSTI)

The survey from US Department of Energy showed that about one-third of energy consumption in US is due to air conditioning and refrigeration systems. This significant usage of electricity in the HVAC industry has prompted researchers to develop...

Gupta, Ankush 1986-

2012-09-27T23:59:59.000Z

38

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

39

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

40

DOE Closes Investigation of Arcelik's Blomberg Refrigerator | Department of  

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

Arcelik's Blomberg Refrigerator Arcelik's Blomberg Refrigerator DOE Closes Investigation of Arcelik's Blomberg Refrigerator September 1, 2010 - 4:37pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Arcelik's Blomberg refrigerator-freezer model # BRFB1450. The Department opened this investigation based on a complaint. DOE subpoenaed information from Arcelik, reviewed Arcelik's response, and performed its own testing of this model. Based on our investigation and test results, DOE has determined this model to be compliant with federal energy conservation standards. Notice of Compliance Determination Addthis Related Articles DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations DOE Closes Investigation of Whirlpool's Maytag Refrigerator

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

ARTI refrigerant database  

SciTech Connect

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

42

Three-Dimensional Electro-Thermal Modeling of Thin Film Micro-Refrigerators for Site-Specific Cooling of VLSI ICs  

E-Print Network (OSTI)

. of Electrical Engineering, University of California at Santa Cruz 1156 High Street, Santa Cruz, CA 95064 1 with micro- refrigerators attached is not a simple task. One di- mensional modeling of thermoelectric coolers is organized as follows. In Section 2, basic principles for thermoe- lectric cooling are reviewed. Section 3

43

Low-GWP Refrigerants Research Project | Department of Energy  

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

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

44

SYNTHESIS: MODELING VARIABILITY AND CONSTRAINTS Rolf Carlson  

E-Print Network (OSTI)

SYNTHESIS: MODELING VARIABILITY AND CONSTRAINTS Rolf Carlson This is a modified version. Abstract This paper discusses some important topics in current speech synthesis research. Modeling of speaker characteristics and emotions are used as a examples of new trends in the speech synthesis field

Carlson, Rolf

45

Modeling and Experimental Investigation of a Variable Speed Drive Water Source Heat Pump  

Science Journals Connector (OSTI)

Accurate variable speed characteristics are needed for water source heat pumps (WSHP) to design variable speed controls to adjust refrigerant flow rates in heat pumps and air conditioners. The system capacity can then be regulated to match the compressor loads to the heating or cooling needs to improve the energy efficiency and lower energy costs. The motor and compression characteristics of WSHP were modeled to include the coupling between the motor speed and the torque characteristics and compression characteristics. An analytical model is given for a variable speed hermetic scroll compressor that describes various factors, such as the drive frequency, suction pressure, and discharge pressure as a function of the compressor speed. The model was validated experimentally using R22 and \\{R134a\\} in an experimental WSHP with variable speed control using frequency conversion. The results show that the analytical model properly describes the variable speed characteristics and provides a control strategy for adjusting the capacity of scroll compressors to match the heat pump or air conditioner operating conditions.

Zhifang Xue; Lin Shi

2010-01-01T23:59:59.000Z

46

North Star Refrigerator: Order (2013-CE-5355)  

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

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

47

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

48

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

49

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.

50

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.

51

Form Date 4/4/01 Refrigerant Service Order Form  

E-Print Network (OSTI)

Recovery Unit ID # : Added Lbs oz Lbs oz Lbs oz Startup Charge Net Refrigerant Added: Lbs oz Parts UsedForm Date 4/4/01 Refrigerant Service Order Form Service ID: Owner: Work Order #: Building: Date: Issued: Completed: Equipment ID: Technicians: Location: Model: Manufact: Serial #: Refrigerant Type

Russell, Lynn

52

Dynamic simulation of a reverse Brayton refrigerator  

SciTech Connect

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

53

Literature survey of heat transfer enhancement techniques in refrigeration applications  

SciTech Connect

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

54

Dissecting magnetar variability with Bayesian hierarchical models  

E-Print Network (OSTI)

Neutron stars are a prime laboratory for testing physical processes under conditions of strong gravity, high density, and extreme magnetic fields. Among the zoo of neutron star phenomena, magnetars stand out for their bursting behaviour, ranging from extremely bright, rare giant flares to numerous, less energetic recurrent bursts. The exact trigger and emission mechanisms for these bursts are not known; favoured models involve either a crust fracture and subsequent energy release into the magnetosphere, or explosive reconnection of magnetic field lines. In the absence of a predictive model, understanding the physical processes responsible for magnetar burst variability is difficult. Here, we develop an empirical model that decomposes magnetar bursts into a superposition of small spike-like features with a simple functional form, where the number of model components is itself part of the inference problem. The cascades of spikes that we model might be formed by avalanches of reconnection, or crust rupture afte...

Huppenkothen, D; Hogg, D W; Murray, I; Frean, M; Elenbaas, C; Watts, A L; Levin, Y; van der Horst, A J; Kouveliotou, C

2015-01-01T23:59:59.000Z

55

Performance of a two-cycle refrigerator/freezer using HFC refrigerants  

SciTech Connect

A two-cycle 18 ft{sup 3} (0.51 m{sup 3}) refrigerator/freezer was tested utilizing American National Standards Institute/Association of Home Appliance Manufacturers (ANSI/AHAM) standards for energy consumption testing. A 34.9% energy consumption reduction was realized for a 1984 model refrigerator/freezer (1020 kWh original energy use). This paper presents a proven method of reducing the current Department of Energy (DOE) minimum energy-efficiency standards for refrigerator/freezers to the proposed year 2001 standards utilizing existing technology. For a top-mount, frost-free refrigerator/freezer having the above volume, the current DOE minimum energy standard is 770 kWh/year, and the proposed DOE year 2001 standard is 530 kWh/year (a 31% reduction). Therefore, some significant reductions may be obtained by implementing the modifications discussed in this paper into newer refrigerator/freezer models. The paper gives an overview of the modifications implemented by a Danish university on a US refrigerator/freezer and presents experimental performance testing results of the refrigerator/freezer. The modifications will cause the refrigerator/freezer to be more expensive, but the performance enhancements should offset cost. No cost analysis is presented in this paper, but a detailed cost analysis of a two-cycle refrigerator/freezer is contained in a 1993 US Environmental Protection Agency (EPA) report (EPA 1993). The refrigerator/freezer was tested using four refrigerants and compressors. Two compressors and refrigerants were tested in the freezer cycle, and four were tested in the fresh food cycle.

Baskin, E.; Delafield, F.R.

1999-07-01T23:59:59.000Z

56

Monitoring refrigeration energy useage.  

SciTech Connect

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

57

ARTI refrigerant database  

SciTech Connect

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

58

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

59

Bayesian variable selection in clustering via dirichlet process mixture models  

E-Print Network (OSTI)

simultane- ously. I use Dirichlet process mixture models to define the cluster structure and to introduce in the model a latent binary vector to identify discriminating variables. I update the variable selection index using a Metropolis algorithm and obtain...

Kim, Sinae

2007-09-17T23:59:59.000Z

60

Manufacture of refrigeration oils  

SciTech Connect

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Energy-efficiency directory of refrigerators and refrigerator-freezers  

SciTech Connect

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

62

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

63

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

64

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

E-Print Network (OSTI)

pump and air conditioner commonly used in residential applications. The simulated results were compared with laboratory tests at two outdoor temperatures. It was found that the ORNL model estimates were within an average of 3% of the experimental...

Farzad, Mohsen

65

ARTI Refrigerant Database  

SciTech Connect

The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air- conditioning and refrigeration equipment. The complete documents are not included, 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

66

Control of household refrigerators. Part 2: Alternate control approaches for improving temperature performance and reducing energy use  

SciTech Connect

In Part 1 it was shown that conventional control of household refrigerators is achieved by regulating the distribution of air in the freezer compartment to all other parts of the plant. In Part 2 three alternative approaches to the conventional control of a top-mount refrigerator are presented: variable temperature bandwidths, uncoupled compressor and evaporator fan, and the combination of these two. These allowed the plant to achieve near-ideal control with respect to improved temperature performance in each compartment. Automatic airflow dampers were used with the dual controllers to independently regulate refrigerator compartment temperature. Plant performance was simulated using a model that computes the refrigerant and airflow systems behavior. Together, these alternate configurations and approaches define new control algorithms that reveal the plant's optimal control model for improving performance and energy usage relative to conventional controllers. Results based on model simulations are dependent upon the model's accuracy and validity. However, the model validation studies cited here, though limited in scope, do show agreement between simulation and experimental data for the ambient temperatures and thermal load conditions considered. This suggests that these model results are reasonable, and representative of actual plant behavior under these conditions and configurations for a top-mount style refrigerator plant.

Graviss, K.J.; Collins, R.L.

1999-07-01T23:59:59.000Z

67

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

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

68

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

69

Multi-stage Cascaded Stirling Refrigerator  

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

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

70

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

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

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...

71

DOE Opens Three Investigations into Alleged Refrigerator Efficiency  

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

Opens Three Investigations into Alleged Refrigerator Efficiency Opens Three Investigations into Alleged Refrigerator Efficiency Violations DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations April 12, 2010 - 7:27pm Addthis The Department of Energy has issued one subpoena and two data requests to three companies in response to allegations that the companies are selling refrigerator-freezers that failed to meet federal energy efficiency standards. Under the subpoena, Arçelik A.S, a Turkish Company is required to submit detailed information about the design, marketing and U.S. sales of its Blomberg brand refrigerator-freezer, model "BRFB1450." The Department also requested testing data from Whirlpool Corporation and Viking Range Corporation for two refrigerator-freezers that the companies

72

DOE Opens Three Investigations into Alleged Refrigerator Efficiency  

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

Opens Three Investigations into Alleged Refrigerator Efficiency Opens Three Investigations into Alleged Refrigerator Efficiency Violations DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations April 12, 2010 - 7:27pm Addthis The Department of Energy has issued one subpoena and two data requests to three companies in response to allegations that the companies are selling refrigerator-freezers that failed to meet federal energy efficiency standards. Under the subpoena, Arçelik A.S, a Turkish Company is required to submit detailed information about the design, marketing and U.S. sales of its Blomberg brand refrigerator-freezer, model "BRFB1450." The Department also requested testing data from Whirlpool Corporation and Viking Range Corporation for two refrigerator-freezers that the companies

73

Rank/sparsity minimization and latent variable graphical model selection  

E-Print Network (OSTI)

Rank/sparsity minimization and latent variable graphical model selection Pablo A. Parrilo · Complication: latent variables · Rank/sparsity decomposition, and generalizations · Convex optimization cond. on other vars. 1 3 2 4 Sparse Low-rank Concentration matrix #12;Proposal for modeling · Decompose

Parrilo, Pablo A.

74

1991 & 1992 trade-in refrigerator metering project  

SciTech Connect

Under SMUD`s Equipment Efficiency Improvement Program the District offers an incentive of $100 to customers who trade in an older refrigerator in conjunction with the purchase of a new model. More than 40,000 refrigerators have been traded in this program as of January 1993. This program has provided 36.5% of the total reported savings from all SMUD`s conservation programs through April 1993. Of this 36.5% reported savings, 84.7% is attributed to the trading in of an old refrigerator for a new model, and only 15.3% to purchases of a new refrigerators without trading in their older model. In 1992 two laboratory studies were undertaken to quantify energy use of older, close to retirement, domestic residential refrigerators from participants in SMUD`s refrigerator trade-in program. One study focused on annual energy use from older model refrigerators received from this program, and the second study focused on potential energy savings from condenser coil cleaning from this same stock of refrigerators. To determine the performance of these refrigerators, a sample of 79 units was randomly selected for testing. Each unit was tested to obtain annual energy use (kWh/yr) and to document physical and operational conditions. A subset of 28 units from this sample was also tested to determine energy savings as a result of cleaning condenser coils. This was done by comparing test results of annual energy use before and after coil cleaning. These refrigerators were tested to the same conventional procedures (commonly called the {open_quotes}DOE{close_quotes} test, or AHAM test procedures) used to arrive at annual energy use labeled on all new refrigerators. Although laboratory results do not exactly replicate field (in-home) results, they have been found to still be a reasonably good predictor of energy use as reported in a Lawrence Berkeley Laboratory study , discussed in the following section.

Bos, W.

1994-12-31T23:59:59.000Z

75

Downhole pulse tube refrigerators  

SciTech Connect

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

76

Application of Best Industry Practices to the Design of Commercial Refrigerators  

SciTech Connect

The substantial efficiency improvements which have been realized in residential refrigerators over the last twenty years due to implementation of the National Appliance Energy Conservation Act and changing consumer reactions to energy savings give an indication of the potential for improvement in the commercial sector, where few such efficiency improvements have been made to date. The purchase decision for commercial refrigerators is still focused primarily on first cost and product performance issues such as maximizing storage capacity, quick pulldown, durability, and reliability. The project applied techniques used extensively to reduce energy use in residential refrigeration to a commercial reach-in refrigerator. The results will also be applicable to other commercial refrigeration equipment, such as refrigerated vending machines, reach-in freezers, beverage merchandisers, etc. The project described in this paper was a collaboration involving the Appliance and Building Technology Sector of TIAX, the Delfield Company, and the U. S. Department of Energy's Office of Building Technologies. Funding was provided by DOE through Cooperative Agreement No. DE-FC26-00NT41000. The program plan and schedule were structured to assure successful integration of the TIAX work on development of efficient design concepts into Delfield's simultaneous development of the Vantage product line. The energy-saving design options evaluated as part of the development included brushless DC and PSC fan motors, high-efficiency compressors, variable-speed compressor technology, cabinet thermal improvement (particularly in the face frame area), increased insulation thickness, a trap for the condensate line, improved insulation, reduced-wattage antisweat heaters, non-electric antisweat heating, off-cycle defrost termination, rifled heat exchanger tubing, and system optimization (selection of heat exchangers, fans, and subcooling, superheat, and suction temperatures for efficient operation). The project started with a thorough evaluation of the baseline Delfield Model 6051 two-door reach-in refrigerator. Performance testing was done to establish a performance baseline which, to meet end-users requirements, would have to be met or exceeded by the high-efficiency refrigerator design. Energy testing was done to establish the baseline energy use. Diagnostic testing such as reverse heat leak testing and insulation conductivity testing was done to evaluate factors contributing to the cabinet load and energy use. Modeling was done to assess the energy savings potential of the energy saving design options. Discussion with vendors and cost modeling was done to assess the manufacturing cost impact of the options. Based on this work, the following group of design options was selected for incorporation in the final refrigerator design: (1) Brushless DC evaporator fans; (2) Improved face frame design; (3) Reduced antisweat heater wattage; (4) Condensate line trap; and (5) Optimized refrigeration system. There was no net cost premium associated with these design changes, leading to a high-efficiency design requiring no payback of any initial additional investment. Delfield incorporated these design options in the Vantage line design and built a first prototype, which was tested at TIAX. Additional design changes were implemented in the transition to manufacturing, based in part on results of initial prototype testing, and a pilot production unit was sent to TIAX for final testing. The energy use of the pilot production unit was 68% less than that of the baseline refrigerator when tested according to the ASHRAE 117 Energy Test Standard. The energy test results for the baseline refrigerator and the two new-design units is shown in Figure ES-1 below. The resulting energy consumption is well below Energy Star and proposed Canadian and California standards levels. Delfield has successfully transitioned the design to production and is manufacturing all configurations of the energy efficient reach-ins at a rate greater than 7,000 per year, with production quantities projec

None

2002-06-30T23:59:59.000Z

77

DOE Closes Investigation of Whirlpool's Maytag Refrigerator | Department of  

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

of Whirlpool's Maytag Refrigerator of Whirlpool's Maytag Refrigerator DOE Closes Investigation of Whirlpool's Maytag Refrigerator July 8, 2010 - 3:12pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Whirlpool's Maytag refrigerator-freezer model "MSD2578VE." The Department opened this investigation and requested testing data from Whirlpool based on a complaint (April 12, 2010, "DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations"). After reviewing the data and testing this model, the Department has found the model to be compliant with the applicable efficiency standards and has closed the investigation. The Department takes credible allegations seriously and will continue to initiate investigations on products that are

78

DOE Closes Investigation of Whirlpool's Maytag Refrigerator | Department of  

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

Closes Investigation of Whirlpool's Maytag Refrigerator Closes Investigation of Whirlpool's Maytag Refrigerator DOE Closes Investigation of Whirlpool's Maytag Refrigerator July 8, 2010 - 3:12pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Whirlpool's Maytag refrigerator-freezer model "MSD2578VE." The Department opened this investigation and requested testing data from Whirlpool based on a complaint (April 12, 2010, "DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations"). After reviewing the data and testing this model, the Department has found the model to be compliant with the applicable efficiency standards and has closed the investigation. The Department takes credible allegations seriously and will continue to initiate investigations on products that are

79

Proceedings: Commercial Refrigeration Research Workshop  

SciTech Connect

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

80

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

International Refrigeration: Proposed Penalty (2012-CE-1510)  

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

International Refrigeration Products International Refrigeration Products (room air conditioners) ) ) ) ) ) Case Number: 2012-CE-1510 NOTICE OF PROPOSED CIVIL PENALTY Date issued: July 9, 2012 Number of alleged violations: 5475 (365 days, 15 models) Maximum possible assessment: $1,095,000 Proposed civil penalty: $109,500 The U.S. Department of Energy ("DOE") Office of the General Counsel, Office of Enforcement, alleges that International Refrigeration Products ("IRP") has violated cettain provisions of the Energy Policy and Conservation Act, 42 U.S.C. § 6291 et seq. ("the Act"), and 10 C.P.R. § 429.12. Specifically, DOE alleges: 1. IRP has manufactured 1 a variety of Sea Breeze brand room air conditioners, including basic models WA46YR, WA48YRX, WA410YRX, WA412YRX, WH418ZRX,

82

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; José P. Palao; Gerardo Adesso; Daniel Alonso

2014-11-24T23:59:59.000Z

83

Refrigerator recycling and CFCs  

SciTech Connect

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

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

1994-12-31T23:59:59.000Z

84

Refrigeration monitor and alarm system  

SciTech Connect

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

85

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

86

Hybrid coupled models of the tropical Pacific: I interannual variability  

E-Print Network (OSTI)

Y. Tang Hybrid coupled models of the tropical Pacific: I interannual variability Received: 20 Two hybrid coupled models (HCMs), an intermediate complexity dynamical ocean model cou- pled to either), hybrid models (e.g., Barnett et al. 1993; Balmaseda et al. 1994,1995), and fully coupled general

Tang, Youmin

87

Enhanced naphthenic refrigeration oils for household refrigerator systems  

SciTech Connect

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

88

Modeling and Estimating Current Harmonics of Variable Electronic Loads  

E-Print Network (OSTI)

This paper develops a model for relating input current harmonic content to real power consumption for variable electronic loads, specifically for loads' actively controlled inverters energized by an uncontrolled rectification ...

Wichakool, Warit

89

Variational inferences for partially linear additive models with variable selection  

Science Journals Connector (OSTI)

This article develops a mean field variational Bayes approximation algorithm for posterior inferences of the recently proposed partially linear additive models with simultaneous and automatic variable selection and linear/nonlinear component identification ... Keywords: Bayesian inference, Mean field variational Bayes, Model selection, Partially linear additive model

Kaifeng Zhao, Heng Lian

2014-12-01T23:59:59.000Z

90

Parameters and variables appearing in repository-siting models  

SciTech Connect

Included in this report is a summary of data characterizing the parameters and variables appearing in repository siting models. These data cover the processes of saturates flow, unsaturated flow, surface water flow, geochemistry, heat transport, solute transport, and geomechanical response. Definitions and ranges of values are provided for equation parameters, source terms, dependent variables, boundary conditions, and initial conditions for the equations that are solved in the repository siting models. The data were compiled to help guide the selection of values of parameters and variables to be used in benchmark problems.

Mercer, J.W.; Thomas, S.D.; Ross, B.

1982-12-01T23:59:59.000Z

91

The Greenhouse Gas Protocol Initiative: GHG Emissions from Refrigeration  

Open Energy Info (EERE)

The Greenhouse Gas Protocol Initiative: GHG Emissions from Refrigeration The Greenhouse Gas Protocol Initiative: GHG Emissions from Refrigeration and Air Conditioning Jump to: navigation, search Tool Summary LAUNCH TOOL Name: The Greenhouse Gas Protocol Initiative: GHG Emissions from Refrigeration and Air Conditioning Agency/Company /Organization: World Resources Institute, World Business Council for Sustainable Development Sector: Energy, Climate Focus Area: Greenhouse Gas Phase: Determine Baseline, Evaluate Effectiveness and Revise as Needed Resource Type: Software/modeling tools User Interface: Spreadsheet Website: www.ghgprotocol.org/calculation-tools/all-tools Cost: Free References: Refrigerant Guide[1] The Greenhouse Gas Protocol tool for refrigeration is a free Excel spreadsheet calculator designed to calculate GHG emissions specifically

92

Renormalization group maps for Ising models in lattice gas variables  

E-Print Network (OSTI)

Real space renormalization group maps, e.g., the majority rule transformation, map Ising type models to Ising type models on a coarser lattice. We show that each coefficient of the renormalized Hamiltonian in the lattice gas variables depends on only a finite number of values of the renormalized Hamiltonian. We introduce a method which computes the values of the renormalized Hamiltonian with high accuracy and so computes the coefficients in the lattice gas variables with high accuracy. For the critical nearest neighbor Ising model on the square lattice with the majority rule transformation, we compute over 1,000 different coefficients in the lattice gas variable representation of the renormalized Hamiltonian and study the decay of these coefficients. We find that they decay exponentially in some sense but with a slow decay rate. We also show that the coefficients in the spin variables are sensitive to the truncation method used to compute them.

Tom Kennedy

2009-05-15T23:59:59.000Z

93

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

94

Multilayer Thermionic Refrigeration  

SciTech Connect

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

95

Essential Terrestrial Variable data workflows for distributed water resources modeling  

Science Journals Connector (OSTI)

This paper discusses a prototype infrastructure, HydroTerre, that provides researchers, educators and resource managers with seamless access to geospatial/geotemporal data for supporting physics-based numerical models. The prototype defines the supporting ... Keywords: Data workflow, Distributed hydrologic model, Essential Terrestrial Variables, Geographic information systems, HydroTerre, PIHM, Web services

Lorne Leonard; Christopher J. Duffy

2013-12-01T23:59:59.000Z

96

DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy Star  

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

Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements March 16, 2010 - 4:28pm Addthis DOE-initiated testing has revealed that a Samsung refrigerator (model RF26VAB), which the company had claimed was Energy Star compliant, consumed more energy than permitted by the Energy Star program. Test results for the Samsung model at issue show that, when tested in accordance with DOE's test procedure, it consumed between 7 and 11.4 percent more energy than the Energy Star requirement. Samsung is no longer manufacturing this model, although it may still be available from some retail outlets. Based on this testing, DOE is referring Samsung Model RF26VAB to the U.S.

97

Optimal Sequencing of Central Refrigeration Equipment in an Industrial Plant  

E-Print Network (OSTI)

A model was developed to find a viable solution to the problem of selecting the optimal sequence of refrigeration equipment (chillers, cooling towers, pumps) to operate in a Central Utility Plant. The optimal equipment sequence is that sequence...

Fiorino, D. P.; Priest, J. W.

1986-01-01T23:59:59.000Z

98

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

99

Vaccine refrigerator testing. Final report  

SciTech Connect

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

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

1990-06-01T23:59:59.000Z

100

An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants  

SciTech Connect

Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Energy Efficiency and Environmental Impact Analyses of Supermarket Refrigeration Systems  

SciTech Connect

This paper presents energy and life cycle climate performance (LCCP) analyses of a variety of supermarket refrigeration systems to identify designs that exhibit low environmental impact and high energy efficiency. EnergyPlus was used to model refrigeration systems in a variety of climate zones across the United States. The refrigeration systems that were modeled include the traditional multiplex DX system, cascade systems with secondary loops and the transcritical CO2 system. Furthermore, a variety of refrigerants were investigated, including R-32, R-134a, R-404A, R-1234yf, R-717, and R-744. LCCP analysis was used to determine the direct and indirect carbon dioxide emissions resulting from the operation of the various refrigeration systems over their lifetimes. Our analysis revealed that high-efficiency supermarket refrigeration systems may result in up to 44% less energy consumption and 78% reduced carbon dioxide emissions compared to the baseline multiplex DX system. This is an encouraging result for legislators, policy makers and supermarket owners to select low emission, high-efficiency commercial refrigeration system designs for future retrofit and new projects.

Fricke, Brian A [ORNL] [ORNL; Bansal, Pradeep [ORNL] [ORNL; Zha, Shitong [Hillphoenix] [Hillphoenix

2013-01-01T23:59:59.000Z

102

Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants  

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

Thermodynamic Evaluation of Thermodynamic Evaluation of Low-GWP Refrigerants Mark O. McLinden National Institute of Standards and Technology markm@boulder.nist.gov; 303-497-3580 April 3, 2013 Optimization Fluid Modeling Cycle Modeling Final Candidates Optimum Thermo Parameters 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: HFC refrigerants face restrictions: U.S./Canada/Mexico proposal to Montreal Protocol (85 % cut) EU regulations likely on all application areas (79 % cut)

103

Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants  

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

Thermodynamic Evaluation of Thermodynamic Evaluation of Low-GWP Refrigerants Mark O. McLinden National Institute of Standards and Technology markm@boulder.nist.gov; 303-497-3580 April 3, 2013 Optimization Fluid Modeling Cycle Modeling Final Candidates Optimum Thermo Parameters 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: HFC refrigerants face restrictions: U.S./Canada/Mexico proposal to Montreal Protocol (85 % cut) EU regulations likely on all application areas (79 % cut)

104

Improving the energy efficiency of refrigerators in India  

SciTech Connect

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

105

NICE3: Industrial Refrigeration System  

SciTech Connect

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

Simon, P.

1999-09-29T23:59:59.000Z

106

Adiabatic Demagnetization Refrigerator Field Mapping and Shielding Models for a 70 mK Superconducting Transition Edge Sensor Array and Associated Electronics  

SciTech Connect

An X-ray detection instrument to be flown on a sounding rocket experiment (the Advanced Technology Solar Spectroscopic Imager -- ATSSI) for solar physics observations is being developed by the Lockheed Martin Solar and Astrophysics Laboratory (LMSAL). The detector is a novel class of microcalorimeter, a superconducting Transition-Edge Sensor (TES), that coupled with associated SQUID and feedback electronics requires high temperature stability at {approx}70 mK to resolve the energy of absorbed X-ray photons emitted from the solar corona. The cooling system incorporates an existing Adiabatic Demagnetization Refrigerator (ADR) developed at the University of Wisconsin (UW), which was previously flown to study the diffuse cosmic X-ray background. The Si thermistor detectors for that project required 130 K shielded JFET electronic components that are much less sensitive to the external field of the ADR solenoid than are the 1st ({approx}70 mK) and 2nd ({approx}2 K) SQUID stages used with TESs for solar observations. Modification of the Wisconsin ADR design, including TES focal plane and electronics re-positioning, therefore requires a tradeoff between the existing ADR solenoid nulling coil geometry and a low mass passive solenoid shield, while preserving the vibration isolation features of the existing design. We have developed models to accurately compute the magnetic field with and without shielding or nulling coils at critical locations to guide the re-design of the detector subsystem. The models and their application are described.

Ladner, D. R. [N-Science Corporation, Arvada, CO 80002 (United States); Martinez-Galarce, D. S. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); McCammon, D. [University of Wisconsin, Madison, WI 53706 (United States)

2006-04-27T23:59:59.000Z

107

Torque modelling for optimising fuel economy in variable compression engines  

Science Journals Connector (OSTI)

Fuel optimal control of a variable compression engine is studied and it is shown that a crucial component is the model for the engine torque. A model for the produced work that captures the important effects of ignition and compression ratio is proposed and investigated. The main task for the model is to be a mean for determining the fuel optimal control signals, for each requested engine torque and speed. The contribution is a model suitable for finding this optimal combination. This model consists of well-known components, and the novelty lies in the compilation and validation of the control-oriented efficiency model for a variable compression engine. The modelling and validation is performed on a multicylinder variable compression engine using two fuels with different octane rating. Despite the models simplicity, it describes the indicated work with good accuracy, and suits its purpose of finding optimal control signals. In the evaluation, it is shown that a fuel optimal controller based on the proposed model captures the optimal IMEP to within 1.2%. This corresponds to a loss in engine efficiency that is in the range of 0.5% units or less.

Ylva Nilsson; Lars Eriksson; Martin Gunnarsson

2008-01-01T23:59:59.000Z

108

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

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

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

109

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect

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

110

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

111

The refrigerator revolution  

SciTech Connect

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

112

Covered Product Category: Residential Refrigerators | Department of Energy  

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

Residential Refrigerators Residential Refrigerators Covered Product Category: Residential Refrigerators October 7, 2013 - 11:19am Addthis ENERGY STAR Qualified Products FEMP provides acquisition guidance across a variety of product categories, including residential refrigerators, which are an ENERGY STAR®-qualified product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law. Most manufacturers display the ENERGY STAR label on complying models. For a model not displaying this label, check the manufacturer's literature to determine if it meets the efficiency requirements outlined by ENERGY STAR. Performance Requirements for Federal Purchases For the most up-to-date efficiency levels required by ENERGY STAR, look for

113

Covered Product Category: Residential Refrigerators | Department of Energy  

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

Refrigerators Refrigerators Covered Product Category: Residential Refrigerators October 7, 2013 - 11:19am Addthis ENERGY STAR Qualified Products FEMP provides acquisition guidance across a variety of product categories, including residential refrigerators, which are an ENERGY STAR®-qualified product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law. Most manufacturers display the ENERGY STAR label on complying models. For a model not displaying this label, check the manufacturer's literature to determine if it meets the efficiency requirements outlined by ENERGY STAR. Performance Requirements for Federal Purchases For the most up-to-date efficiency levels required by ENERGY STAR, look for

114

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

115

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

116

A single dimensionless variable for solar chimney power plant modeling  

SciTech Connect

The solar chimney power plant is a relatively new technology for generating electricity from solar energy. In this paper dimensional analysis is used together with engineering intuition to combine eight primitive variables into only one dimensionless variable that establishes a dynamic similarity between a prototype and its scaled models. Three physical configurations of the plant were numerically tested for similarity: fully geometrically similar, partially geometrically similar, and dissimilar types. The values of the proposed dimensionless variable for all these cases were found to be nominally equal to unity. The value for the physical plant actually built and tested previously was also evaluated and found to be about the same as that of the numerical simulations, suggesting the validity of the proposition. The physical meaning of this dimensionless (similarity) variable is also interpreted; and the connection between the Richardson number and this new variable was found. It was found also that, for a fixed solar heat flux, different-sized models that are fully or partially geometrically similar share an equal excess temperature across the roof outlet. (author)

Koonsrisuk, Atit; Chitsomboon, Tawit [School of Mechanical Engineering, Institute of Engineering, Suranaree University of Technology, Muang District, Nakhon Ratchasima 30000 (Thailand)

2009-12-15T23:59:59.000Z

117

Malone cycle refrigerator development  

SciTech Connect

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

118

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

119

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

SciTech Connect

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

120

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

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

122

Synopsis of residential refrigerator/freezer alternative refrigerants evaluation  

SciTech Connect

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

123

Refrigerator-freezer energy testing with alternative refrigerants  

SciTech Connect

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

124

Performance bound for quantum absorption refrigerators  

E-Print Network (OSTI)

An implementation of quantum absorption chillers with three qubits has been recently proposed, that is ideally able to reach the Carnot performance regime. Here we study the working efficiency of such self-contained refrigerators, adopting a consistent treatment of dissipation effects. We demonstrate that the coefficient of performance at maximum cooling power is upper bounded by 3/4 of the Carnot performance. The result is independent of the details of the system and the equilibrium temperatures of the external baths. We provide design prescriptions that saturate the bound in the limit of a large difference between the operating temperatures. Our study suggests that delocalized dissipation, which must be taken into account for a proper modelling of the machine-baths interaction, is a fundamental source of irreversibility which prevents the refrigerator from approaching the Carnot performance arbitrarily closely in practice. The potential role of quantum correlations in the operation of these machines is also investigated.

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

2012-12-18T23:59:59.000Z

125

The application of Stirling cooler to refrigeration  

SciTech Connect

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

126

MagLab - Dilution Refrigerator  

NLE Websites -- All DOE Office Websites (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...

127

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

128

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

129

The Proof is in the Pudding: How Refrigerator Standards Have Saved  

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

The Proof is in the Pudding: How Refrigerator Standards Have Saved The Proof is in the Pudding: How Refrigerator Standards Have Saved Consumers $Billions The Proof is in the Pudding: How Refrigerator Standards Have Saved Consumers $Billions July 11, 2011 - 12:33pm Addthis Today’s refrigerators have been designed to save energy and money without detriment to capacity, functionality, or extra features. | Image source: Building Technologies Program Today's refrigerators have been designed to save energy and money without detriment to capacity, functionality, or extra features. | Image source: Building Technologies Program Roland Risser Roland Risser Program Director, Building Technologies Office What does this mean for me? Today's refrigerators use only about 25 percent of the energy compared to models built in 1975. They've also increased in size by almost 20 percent, with lots of

130

The Proof is in the Pudding: How Refrigerator Standards Have Saved  

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

The Proof is in the Pudding: How Refrigerator Standards Have Saved The Proof is in the Pudding: How Refrigerator Standards Have Saved Consumers $Billions The Proof is in the Pudding: How Refrigerator Standards Have Saved Consumers $Billions July 11, 2011 - 12:33pm Addthis Today’s refrigerators have been designed to save energy and money without detriment to capacity, functionality, or extra features. | Image source: Building Technologies Program Today's refrigerators have been designed to save energy and money without detriment to capacity, functionality, or extra features. | Image source: Building Technologies Program Roland Risser Roland Risser Program Director, Building Technologies Office What does this mean for me? Today's refrigerators use only about 25 percent of the energy compared to models built in 1975. They've also increased in size by almost 20 percent, with lots of

131

Grassmann Variables and the Jaynes-Cummings Model  

E-Print Network (OSTI)

This paper shows that phase space methods using a positive P type distribution function involving both c-number variables (for the cavity mode) and Grassmann variables (for the two level atom) can be used to treat the Jaynes-Cummings model. Although it is a Grassmann function, the distribution function is equivalent to six c-number functions of the two bosonic variables. Experimental quantities are given as bosonic phase space integrals involving the six functions. A Fokker-Planck equation involving both left and right Grassmann differentiation can be obtained for the distribution function, and is equivalent to six coupled equations for the six c-number functions. The approach used involves choosing the canonical form of the (non-unique) positive P distribution function, where the correspondence rules for bosonic operators are non-standard and hence the Fokker-Planck equation is also unusual. Initial conditions, such as for initially uncorrelated states, are used to determine the initial distribution function. Transformations to new bosonic variables rotating at the cavity frequency enables the six coupled equations for the new c-number functions (also equivalent to the canonical Grassmann distribution function) to be solved analytically, based on an ansatz from a 1980 paper by Stenholm. It is then shown that the distribution function is the same as that determined from the well-known solution based on coupled equations for state vector amplitudes of atomic and n-photon product states. The treatment of the simple two fermion mode Jaynes-Cummings model is a useful test case for the future development of phase space Grassmann distribution functional methods for multi-mode fermionic applications in quantum-atom optics.

Bryan J. Dalton; Barry M. Garraway; John Jeffers; Stephen M. Barnett

2012-03-22T23:59:59.000Z

132

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

133

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

134

Energy use test procedures for appliances: A case study of Japanese refrigerators  

SciTech Connect

The energy test procedure provides a consistent measurement of refrigerator energy consumption, which can be used by engineers, utility forecasters, and consumers. The U.S. and Japanese test procedures for refrigerators differ significantly, so it is impossible to directly compare the performance of unique features, or even determine which units are more efficient. The energy use of 12 Japanese refrigerators (of which 9 were unique models) were measured under the U.S. DOE energy test procedure and compared to that reported by the manufacturers under the Japanese test procedure. The Japanese refrigerators used substantially more electricity with the DOE test.

Meier, A.K.

1987-06-01T23:59:59.000Z

135

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  

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

136

DOE Closes Investigation into Energy Efficiency of Viking Refrigerator |  

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

Closes Investigation into Energy Efficiency of Viking Closes Investigation into Energy Efficiency of Viking Refrigerator DOE Closes Investigation into Energy Efficiency of Viking Refrigerator November 9, 2010 - 7:30pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Viking Range Corporation's refrigerator-freezer model VCSB542. The Department initiated this investigation in response to allegations that the model failed to meet federal energy efficiency standards. After reviewing data provided by Viking for this model, the Department issued a testing demand on June 16, 2010 and initially tested four units, one of which was defective and replaced by a fifth unit. The test results showed that two Viking units failed the federal energy standard for maximum energy use, while two passed. Because of the wide variation in the

137

DOE Closes Investigation into Energy Efficiency of Viking Refrigerator |  

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

into Energy Efficiency of Viking into Energy Efficiency of Viking Refrigerator DOE Closes Investigation into Energy Efficiency of Viking Refrigerator November 9, 2010 - 7:30pm Addthis The Department of Energy has closed its investigation into the energy efficiency of Viking Range Corporation's refrigerator-freezer model VCSB542. The Department initiated this investigation in response to allegations that the model failed to meet federal energy efficiency standards. After reviewing data provided by Viking for this model, the Department issued a testing demand on June 16, 2010 and initially tested four units, one of which was defective and replaced by a fifth unit. The test results showed that two Viking units failed the federal energy standard for maximum energy use, while two passed. Because of the wide variation in the

138

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...

139

Modeling variable density effects in turbulent flames -- Some basic considerations  

SciTech Connect

The paper discusses the basic physical phenomena involved in pressure-density interactions, and presents models of pressure-velocity, pressure-scalar, baroclinic and dilatation effects for variable density low Mach-number turbulence. Their implementation in the {kappa}-{epsilon} framework is then described and their performance evaluated. The models assume that both scalar transport and turbulence generation arising from pressure-density interactions in flames are caused by the motion of large scale turbulent thermals superposed on the normal turbulence mechanism. The velocity of the thermals is related directly to the mean pressure gradient and local density differences in the flames. It is furthermore assumed that the correction for dilatation effects in the {kappa}-{epsilon} system can be determined from the constraint of conservation of the angular momentum of turbulence per unit mass. Simple corrections of the {kappa}-{epsilon} system are proposed for fast chemistry diffusion and premixed flames subject to variable pressure gradients, which offer substantial improvements in the predictions of the flames. some problems remain, particularly in predictions of turbulence in premixed flames, owing to large scale instabilities of the flames observed in the experiments.

Chomiak, J.; Nisbet, J.R. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics] [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Thermo and Fluid Dynamics

1995-08-01T23:59:59.000Z

140

Measurement and Modeling of Solar and PV Output Variability: Preprint  

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

Measurement and Modeling of Measurement and Modeling of Solar and PV Output Variability Preprint M. Sengupta To be presented at SOLAR 2011 Raleigh, North Carolina May 17-21, 2011 Conference Paper NREL/CP-5500-51105 April 2011 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (Alliance), a contractor of the US Government under Contract No. DE-AC36-08GO28308. Accordingly, the US Government and Alliance retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty,

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Observational Constraints of New Variable Modified Chaplygin Gas Model  

E-Print Network (OSTI)

Assuming the flat FRW universe in Einstein's gravity filled with New Variable Modified Chaplygin gas (NVMCG) dark energy and dark matter having negligible pressure. In this research work we analyze the viability on the basis of recent observation. Hubble parameter $H$ is expressed in terms of the observable parameters $H_0$, $\\Omega_m^0$ and the model parameters $A_0$, $B_0$, $C_0$, $m$, $n$, $\\alpha$ and the red shift parameter $z$. Here we find a best fitted parameter range of $A_0$, $B_0$ keeping $0\\leq \\alpha \\leq 1$ and using Stern data set (12 points) by minimizing the $\\chi^2$ test at 66%, 90% and 99% confidence levels. Next we do the joint analysis with BAO and CMB observations. Again evaluating the distance modulus $\\mu(z)$ vs redshift ($z$) curve obtained in the model NVMCG with dark matter with the best fitted value of the parameters and comparing with that derived from the union2 compilation data.

Jhumpa Bhadra; Ujjal Debnath

2012-11-09T23:59:59.000Z

142

Superinsulation in refrigerators and freezers  

SciTech Connect

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

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

1998-02-01T23:59:59.000Z

143

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

144

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

145

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

146

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

147

International Refrigeration: Order (2012-CE-1510)  

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

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

148

Cloud speed impact on solar variability scaling â?? Application to the wavelet variability model  

E-Print Network (OSTI)

Kleissl, J. , 2013. Deriving cloud velocity from an array ofCloud Speed Impact on Solar Variability Scaling -this work, we determine from cloud speeds. Cloud simulator

Lave, Matthew; Kleissl, Jan

2013-01-01T23:59:59.000Z

149

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

SciTech Connect

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

150

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. Barnés; C. Judson King

1974-10-01T23:59:59.000Z

151

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

152

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

153

Dynamic Exergy Analysis of a Solar Ejector Refrigeration System with Hot Water Storage Tank  

Science Journals Connector (OSTI)

A dynamic model is proposed to use in investigating the exergy analysis of a solar ejector refrigeration system using R141, for office ... in Tehran. Classical hourly outdoor temperature and solar radiation model...

Hooman Golchoobian; Ali Behbahaninia…

2014-01-01T23:59:59.000Z

154

Covered Product Category: Residential Refrigerators  

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

FEMP provides acquisition guidance across a variety of product categories, including residential refrigerators, which are an ENERGY STAR®-qualified product category. Federal laws and executive orders mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

155

Using Variable Precision Rough Set Model to Build FP-Tree of Association Rules  

Science Journals Connector (OSTI)

The main mission of the variable precision rough set is to solve the problem of non- ... of association rules algorithms based on variable precision rough set model in e-commerce. The experiments show...

SuJuan Qian; ZhiQiang Zhang

2012-01-01T23:59:59.000Z

156

Energy consumption testing of innovative refrigerator-freezers  

SciTech Connect

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

157

Testing, Model Simulations of the Thermocline Depth Variability in the Tropical Atlantic from 1982 through 1984  

Science Journals Connector (OSTI)

The multivariate model toning procedure of Frankignoul et al. has been extended to the general time-series case, thus allowing to test ocean model ability at simulating the interannual variability. The method aims at distinguishing between model ...

Pascale Braconnot; Claude Frankignoul

1993-04-01T23:59:59.000Z

158

Bayesian latent variable modelling in studies of air pollution and health  

E-Print Network (OSTI)

Bayesian latent variable modelling in studies of air pollution and health Duncan Lee, Gavin://www.bath.ac.uk/math-sci/BICS #12;Bayesian latent variable modelling in studies of air pollution and health. Duncan Lee (1), Gavin to the approach adopted for modelling the trend and correlation. KEYWORDS: Air pollution and health; Bayesian

Burton, Geoffrey R.

159

Markov Chain Models for GP and Variable-length GAs with Homologous Crossover  

E-Print Network (OSTI)

Markov Chain Models for GP and Variable-length GAs with Homologous Crossover Riccardo Poli School mcphee@mrs.umn.edu Abstract In this paper we present a Markov chain model for GP and variable-length GAs of the genetic material taken from the parents. We obtain this result by using the core of Vose's model for GAs

Poli, Riccardo

160

Evaluation of ozone-friendly hydrofluoropropane-based zeotropic refrigerant mixtures in a Lorenz-Meutzner refrigerator/freezer  

SciTech Connect

The design of the Lorenz-Meutzner refrigerator/freezer has two evaporators (located in the freezer and fresh food compartments), which makes it a leading candidate for use of zeotropic refrigerant mixtures. Zeotropic mixtures can have significant temperature glides during evaporation and condensation. Performance of the zeotropic mixture can be maximized in the LM design by permitting the lower end of the temperature glide to occur in the freezer compartment evaporator and the higher end in the fresh food compartment evaporator. Several hydrofluoropropane-based zeotropes (e.g., R-227 ea/R-245ca) have been shown through steady-state modeling to outperform R-134a by up to 15%. Results from previous testing of this refrigerator/freezer using R-32/R-124 (zeotropic mixture) were published in an ASHRAE paper (Sand et al. 1993). Their results showed performance gains of approximately 3% over R-12. In the study presented in this paper, the Lorenz-Meutzner refrigerator/freezer having two evaporators and two intercoolers was experimentally tested in an environmental chamber according to Association of Home Appliance Manufacturers/Department of Energy (AHAM/DOE) testing standards using several hydrofluoropropane-based zeotropic mixtures. The results are compared to baseline testing with R-134a. The R-245ca/R-134a and R-245ca/R-152a mixtures performed comparably to R-134a. R-245ca/R-270 outperformed all zeotropic mixtures and R-134a by at least 16%. Also, a refrigerant sampling loop is added to determine the running composition of the mixture and its effects on the performance of the refrigerator/freezer.

Baskin, E. [Environmental Protection Agency, Research Triangle Park, NC (United States); Bayoglu, E.S.; Delafield, F.R. [Acurex Environmental Corp., Durham, NC (United States)

1997-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Quantum-enhanced absorption refrigerators  

E-Print Network (OSTI)

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

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

2013-08-19T23:59:59.000Z

162

HFC supermarket refrigeration demonstration. Phases 1 and 2  

SciTech Connect

The HFC Supermarket Refrigeration Demonstration tested and evaluated HFC refrigerants in a new Shop `n Save supermarket in Glens Falls, New York. This project included laboratory testing of HFC refrigerants for medium- and low-temperature application, the design of a supermarket refrigeration system to accommodate the new refrigerants, installation, start-up, and field monitoring.

Borhanian, H.; Rafuse, L.

1996-04-01T23:59:59.000Z

163

Suction muffler for refrigeration compressor  

DOE Patents (OSTI)

A hermetic refrigeration compressor includes a suction muffler formed from two pieces of plastic material mounted on the cylinder housing. One piece is cylindrical in shape with an end wall having an aperture for receiving a suction tube connected to the cylinder head. The other piece fits over and covers the other end of the cylindrical piece, and includes a flaring entrance horn which extends toward the return line on the sidewall of the compressor shell. 5 figs.

Nelson, R.T.; Middleton, M.G.

1983-01-25T23:59:59.000Z

164

Solar sorption refrigeration in Africa  

Science Journals Connector (OSTI)

Abstract Solar sorption refrigeration technologies are regarded as a promising way to meet the growing refrigeration needs in Africa, for thermal comfort, foods and crops, vaccines and medicines conservation. Sorption technologies projects and studies have been reported in Africa since the late 1970s. This paper describes the most representative reported research activities and projects in various African climatic conditions. An emphasis is put on demonstrative plants involving absorption, adsorption or desiccant cooling applications. From this overview, it appears that a lot of achievements have been made, though applications are mainly focused on small-size cold boxes for foods and vaccines preservation; no direct building air conditioning based on adsorption or absorption has been reported. Mediterranean countries seems to offer the best weather conditions for solar sorption refrigeration applications and plenty of related activities could be identified in these countries. A more adequate design for each of other climatic zones in Africa may then be relevant. As anywhere, the high cost of these technologies remains the main the biggest brake to their diffusion in Africa.

Kokouvi Edem N’Tsoukpoe; Daniel Yamegueu; Justin Bassole

2014-01-01T23:59:59.000Z

165

Exergetic optimization of a refrigeration cycle for natural gas liquefaction  

Science Journals Connector (OSTI)

Abstract Natural gas is widely use in many industries as fuel and also as raw material. Although gas pipelines present less transportation losses they become impracticable when distances are too long or when demands are highly variable. The liquefaction of natural gas is then necessary to allow its transportation in great volumes, with little loss of material. This also enables its storage in a more stable way. Natural gas consumption is continuously growing worldwide and consequently, the number of exporter terminals (liquefaction industries) and importer terminals (regasification plants) will increase. The natural gas liquefaction process is based on a sequence of refrigeration cycles, which need to work in an optimized way. The exergetic analysis is a very useful thermodynamic tool to evaluate the efficiency of these cycles. This work aims at an exergetic analysis of a multistage cascade refrigeration cycle applied to a natural gas liquefaction process. Firstly, the process was simulated using commercial software and the results obtained from the simulations were validated with literature data, showing a good agreement. After that, different operational conditions, according to a complete factorial design of experiments, were studied, in order to verify the influence of pressure in six specific points of the cycle. The response variable analyzed is the rate of total exergy destroyed in the cycle. The results showed a new set of operational condition to the refrigeration cycle in which the destroyed exergy rate was reduced by approximately 48% in comparison with literature data.

Liza Cipolato; Maria C.A. Lirani; Thiago V. Costa; Francine M. Fábrega; José V.H. d'Angelo

2012-01-01T23:59:59.000Z

166

Determining the minimum mass and cost of a magnetic refrigerator  

E-Print Network (OSTI)

An expression is determined for the mass of the magnet and magnetocaloric material needed for a magnetic refrigerator and these are determined using numerical modeling for both parallel plate and packed sphere bed regenerators as function of temperature span and cooling power. As magnetocaloric material Gd or a model material with a constant adiabatic temperature change, representing a infinitely linearly graded refrigeration device, is used. For the magnet a maximum figure of merit magnet or a Halbach cylinder is used. For a cost of \\$40 and \\$20 per kg for the magnet and magnetocaloric material, respectively, the cheapest 100 W parallel plate refrigerator with a temperature span of 20 K using Gd and a Halbach magnet has 0.8 kg of magnet, 0.3 kg of Gd and a cost of \\$35. Using the constant material reduces this cost to \\$25. A packed sphere bed refrigerator with the constant material costs \\$7. It is also shown that increasing the operation frequency reduces the cost. Finally, the lowest cost is also found a...

Bjørk, R; Bahl, C R H; Pryds, N

2014-01-01T23:59:59.000Z

167

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

168

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.

169

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

SciTech Connect

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

170

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

171

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...

172

Covered Product Category: Commercial Refrigerators and Freezers  

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

The Federal Energy Management Program (FEMP) provides acquisition guidance for commercial refrigerators and freezers, which are covered by the ENERGY STAR program.

173

Design of Industrial Process Refrigeration Systems  

E-Print Network (OSTI)

DESIGN OF INDUSTRIAL PROCESS REfRIGERATION SYSTEMS W.O. WITHERELL AOVENTg Technolog1st Un10n Carb1de Corporat1on South Charleston, West V1rg~n1a ABSTRACT ~hen considering electric driven refrigeration compressors, proper integration... to several canple~ processes that ut iii ze refr igerat ion systems. In IOClSt cases the design of a cOOlllex refrigeration system in isolation (i.e., without considering process integration) generallv results in non-ptilTUll refrigeration levels...

Witherell, W. D.

174

Covered Product Category: Refrigerated Beverage Vending Machines...  

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

vending machines are equipped with controls or software that put the lighting andor refrigeration systems into a low power state at night, on weekends, or other periods of...

175

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

176

Layer of protection analysis applied to ammonia refrigeration systems  

E-Print Network (OSTI)

Ammonia refrigeration systems are widely used in industry. Demand of these systems is expected to increase due to the advantages of ammonia as refrigerant and because ammonia is considered a green refrigerant. Therefore, it is important to evaluate...

Zuniga, Gerald Alexander

2009-05-15T23:59:59.000Z

177

Assessment of Modes of Interannual Variability of Southern Hemisphere Atmospheric Circulation in CMIP5 Models  

Science Journals Connector (OSTI)

An assessment is made of the modes of interannual variability in the seasonal mean summer and winter Southern Hemisphere (SH) 500-hPa geopotential height in the twentieth century in models from the Coupled Model Intercomparison Project (CMIP) ...

Simon Grainger; Carsten S. Frederiksen; Xiaogu Zheng

2014-11-01T23:59:59.000Z

178

Simulating effects of multispeed compressors on refrigerator/freezer performance  

SciTech Connect

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

179

Analysis of household refrigerators for different testing standards  

SciTech Connect

This study highlights the salient differences among various testing standards for household refrigerator-freezers and proposes a methodology for predicting the performance of a single evaporator-based vapor-compression refrigeration system (either refrigerator or freezer) from one test standard (where the test data are available-the reference case) to another (the alternative case). The standards studied during this investigation include the Australian-New Zealand Standard (ANZS), the International Standard (ISO), the American National Standard (ANSI), the Japanese Industrial Standard (JIS), and the Chinese National Standard (CNS). A simple analysis in conjunction with the BICYCLE model (Bansal and Rice 1993) is used to calculate the energy consumption of two refrigerator cabinets from the reference case to the alternative cases. The proposed analysis includes the effect of door openings (as required by the JIS) as well as defrost heaters. The analytical results are found to agree reasonably well with the experimental observations for translating energy consumption information from one standard to another.

Bansal, P.K. [Univ. of Auckland (New Zealand). Dept. of Mechanical Engineering; McGill, I. [Fischer and Paykel Ltd., Auckland (New Zealand)

1995-08-01T23:59:59.000Z

180

Improvement of the Performance for an Absorption Refrigeration System with Lithium bromide-water as Refrigerant by Increasing Absorption Pressure  

E-Print Network (OSTI)

Because the absorption refrigeration system uses the Lithium bromide- water solution as refrigerant, it is profitable for the environment that human beings are living since the values of ODP and GWP of the refrigerant almost are zero. However...

Xie, G.; Sheng, G.; Li, G.; Pan, S.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

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 temperature—a 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

182

Fridge of the future: ORNL`s refrigeration R&D  

SciTech Connect

Fears about warming the globe may change the way foods are chilled. Concern about global warming, as expressed in the President`s Climate Change Action Plan of 1993, is the latest motivation for putting future American refrigerators and freezers on a strict energy diet. A current national goal is to design an environmentally sound refrigerator-freezer by 1998 that uses half as much energy as 1993 models. Interest in designing a more energy-efficient refrigerator is not new. It first became a goal almost 20 years ago. In the 1970`s the United States was relying on increasingly unstable supplies of imported oil for fuel, and energy prices began to rise. Utilities balked at building additional power plants because of rising costs and investment risks. As a result, a premium was placed on developing energy-efficient appliances, culminating in the passage of the National Appliance Energy Conservation Act of 1987. In the late 1980`s refrigerator design was again a target of engineers because of the need to change the refrigerant and insulation used. The reason: the Montreal Protocol called for phasing out of substances containing chlorofluorocarbons (CFCs) by the year 2000 because they were thought to be destroying the earth`s stratospheric ozone layer. Ozone shields humans from solar rays that can cause skin cancer and cataracts. Among the CFCs to be phased out are common refrigerants like R-12 and the refrigerator insulation blowing agent R-11.

Krause, C.

1995-12-31T23:59:59.000Z

183

Federal Energy Management Program: Covered Product Category: Refrigerated  

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

Refrigerated Beverage Vending Machines to someone by E-mail Refrigerated Beverage Vending Machines to someone by E-mail Share Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on Facebook Tweet about Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on Twitter Bookmark Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on Google Bookmark Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on Delicious Rank Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on Digg Find More places to share Federal Energy Management Program: Covered Product Category: Refrigerated Beverage Vending Machines on AddThis.com...

184

DOE Opens Three Investigations into Alleged Refrigerator Efficiency...  

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

Opens Three Investigations into Alleged Refrigerator Efficiency Violations DOE Opens Three Investigations into Alleged Refrigerator Efficiency Violations April 12, 2010 - 7:27pm...

185

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

186

Working Fluids Low Global Warming Potential Refrigerants | Department...  

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

Center. Life Cycle Climate Performance of supermarket refrigeration.
Credit: Oak Ridge National Lab Life Cycle Climate Performance of supermarket refrigeration....

187

Transportation Refrigeration Unit (TRU) Retrofit with HUSS Active...  

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

Transportation Refrigeration Unit (TRU) Retrofit with HUSS Active Diesel Particulate Filters Transportation Refrigeration Unit (TRU) Retrofit with HUSS Active Diesel Particulate...

188

DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy...  

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

Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements DOE Testing Reveals Samsung Refrigerator Does Not Meet Energy Star Requirements March 16, 2010 - 4:28pm...

189

2014-04-10 Issuance: Test Procedures for Commercial Refrigeration...  

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

0 Issuance: Test Procedures for Commercial Refrigeration Equipment; Final Rule 2014-04-10 Issuance: Test Procedures for Commercial Refrigeration Equipment; Final Rule This document...

190

Chapter 7, Refrigerator Recycling Evaluation Protocol: The Uniform...  

Office of Environmental Management (EM)

of refrigerators recycled through the program EXISTINGUEC The average annual unit energy consumption of participating refrigerators PARTUSE The portion of the year the...

191

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

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

Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants - 2013 Peer Review Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants - 2013 Peer Review...

192

Working Fluids Low Global Warming Potential Refrigerants - 2013...  

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

Working Fluids Low Global Warming Potential Refrigerants - 2013 Peer Review Working Fluids Low Global Warming Potential Refrigerants - 2013 Peer Review Emerging Technologies...

193

Nonparametric estimation of econometric models with categorical variables  

E-Print Network (OSTI)

-validated smoothing parameters differ in their asymptotic behavior depending on whether a variable is uniformly distributed or not. In chapter IV, we consider a k-n-n estimation of regression function with k selected by a cross validation method. We consider both...

Ouyang, Desheng

2006-10-30T23:59:59.000Z

194

Research and development of highly energy-efficient supermarket refrigeration systems. Volume 2. Supplemental laboratory testing  

SciTech Connect

The Supermarket Refrigeration System project was structured to investigate and develop a new, highly energy-efficient supermarket refrigeration system which features unequal, parallel compressors, microprocessor suction pressure control, and floating head pressure control. Energy savings are achieved because such a system is better able to match compressor capacity with the required refrigeration load. For this same reason, the unequal, parallel compressor system can operate at the lowest possible condenser pressure. The combined effect of highest possible suction pressure and lowest possible condensing pressure substantially increases the energy efficiency ratio (EER) of the refrigeration system. The test conditions included winter and spring ambient temperatures ranging from 8/sup 0/ to 70/sup 0/F, refrigerants R-12 and R-502 with corresponding evaporator temperatures of 20/sup 0/ and -20/sup 0/F, respectively, and variable refrigeration loads between 100,000 and 170,000 Btu/hr. Heat reclaim tests were performed with R-12 only. For the three sets of tests performed, R-12, R-12 with heat reclaim, and R-502, the highest system EER was achieved when the unequal, parallel compressor system was operated with microprocessor control and floating head control.

Toscano, W.M.; Walker, D.H.; Tetreault, R.D.

1983-06-01T23:59:59.000Z

195

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

196

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

197

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

198

Final Scientific/Technical Report for DOE/EERE project Advanced Magnetic Refrigerant Materials  

SciTech Connect

A team led by GE Global Research developed new magnetic refrigerant materials needed to enhance the commercialization potential of residential appliances such as refrigerators and air conditioners based on the magnetocaloric effect (a nonvapor compression cooling cycle). The new magnetic refrigerant materials have potentially better performance at lower cost than existing materials, increasing technology readiness level. The performance target of the new magnetocaloric material was to reduce the magnetic field needed to achieve 4 °C adiabatic temperature change from 1.5 Tesla to 0.75 Tesla. Such a reduction in field minimizes the cost of the magnet assembly needed for a magnetic refrigerator. Such a reduction in magnet assembly cost is crucial to achieving commercialization of magnetic refrigerator technology. This project was organized as an iterative alloy development effort with a parallel material modeling task being performed at George Washington University. Four families of novel magnetocaloric alloys were identified, screened, and assessed for their performance potential in a magnetic refrigeration cycle. Compositions from three of the alloy families were manufactured into regenerator components. At the beginning of the project a previously studied magnetocaloric alloy was selected for manufacturing into the first regenerator component. Each of the regenerators was tested in magnetic refrigerator prototypes at a subcontractor at at GE Appliances. The property targets for operating temperature range, operating temperature control, magnetic field sensitivity, and corrosion resistance were met. The targets for adiabatic temperature change and thermal hysteresis were not met. The high thermal hysteresis also prevented the regenerator components from displaying measurable cooling power when tested in prototype magnetic refrigerators. Magnetic refrigerant alloy compositions that were predicted to have low hysteresis were not attainable with conventional alloy processing methods. Preliminary experiments with rapid solidification methods showed a path towards attaining low hysteresis compositions should this alloy development effort be continued.

Johnson, Francis

2014-06-30T23:59:59.000Z

199

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

200

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Two Tales of Variable Selection for High Dimensional Regression: Screening and Model Building  

E-Print Network (OSTI)

Two Tales of Variable Selection for High Dimensional Regression: Screening and Model Building C and Model Building Cong Liu, Tao Shi and Yoonkyung Lee Department of Statistics, The Ohio State University at two stages of statistical modeling, namely screening and formal model building, with different goals

Shi, Tao

202

Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic formations  

E-Print Network (OSTI)

Evaluating variable switching and flash methods in modeling carbon sequestration in deep geologic performance computing to assess the risks involved in carbon sequestration in deep geologic formations-thermal- chemical processes in variably saturated, non-isothermal porous media is applied to sequestration

Mills, Richard

203

Exergy analysis of a two-stage refrigeration cycle using two natural substitutes of HCFC22  

Science Journals Connector (OSTI)

The aim of the present paper is to carry out a detailed exergy analysis of a two-stage vapour compression cycle by calculating its components exergetic losses. The exergy equations have been developed using refrigerant thermodynamic properties computed by means of a simple model of local equations of states. The results of the exergy analysis of a two-stage refrigeration system operating between a constant evaporating temperature of -30°C and condensation temperatures of 30, 40, 50 and 60°C with two natural substitutes of HCFC22, namely, propane (R290) and ammonia (R717) as working fluids, are presented. It is found that the most significant losses occur in the compressors, expansion valves and condenser. Furthermore, it is shown that the optimum inter-stage pressure for a two-stage refrigeration system is very close to the saturation pressure corresponding to the arithmetical mean of the refrigerant condensation and evaporation temperatures.

Ahmed Ouadha; Mohammed En-nacer; Lahouari Adjlout; Omar Imine

2005-01-01T23:59:59.000Z

204

Demand Side Management by controlling refrigerators and its effects on consumers  

Science Journals Connector (OSTI)

Demand Side Management in power grids has become more and more important in recent years. Continuously growing energy demand both increases the need for distributed generation from renewable energy sources and brings out the topic of Demand Side Management. One of the major application areas of Demand Side Management in smart grids is cooling systems. In this paper, Demand Side Management with control of a refrigerator and its economic effects on consumers are analyzed. With a refrigerator model based on real measurements, several cooling schedules are simulated and annual energy fees for different pricing methods in use in Turkey are calculated and discussed. The results revealed that, 37.9% of refrigerator’s demand in peak period can be shifted to other periods and annual electricity bills for customers can be reduced by 11.4%.

M. Alparslan Zehir; Mustafa Bagriyanik

2012-01-01T23:59:59.000Z

205

Computers and Chemical Engineering 31 (2007) 15901601 Optimal operation of simple refrigeration cycles  

E-Print Network (OSTI)

with a constant setpoint policy. For the CO2 cycle on the other hand, a combination of measurements is necessary cycles Part II: Selection of controlled variables Jørgen Bauck Jensen, Sigurd Skogestad Department February 2007 Abstract The paper focuses on operation of simple refrigeration cycles and considers

Skogestad, Sigurd

206

Process Systems Engineering Optimal Synthesis of Refrigeration Cycles  

E-Print Network (OSTI)

Process Systems Engineering Optimal Synthesis of Refrigeration Cycles and Selection of Refrigerants, University Park, PA 16802 The optimal synthesis of the refrigeration configuration and the selection of the best refrigerants that satisfy a set of process cooling duties at different temperatures is ad- dressed

Maranas, Costas

207

DOE Publishes Supplemental Proposed Determination for Miscellaneous Residential Refrigeration Products  

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

The Department of Energy has published a supplemental proposed determination regarding miscellaneous residential refrigeration products.

208

Refrigerator/freezer energy use: Measured values vs. simulation results  

SciTech Connect

The EPA Refrigerator Analysis (ERA) program was utilized in the engineering analysis performed to support the proposed refrigerator/freezer standards in the United States. In this paper the accuracy of the ERA program for predicting the energy consumption of domestic refrigerators, freezers, and refrigerator-freezers is studied by comparing the predicted energy consumption with the measured energy consumption.

Hakim, S.H.; Turiel, I. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1997-12-31T23:59:59.000Z

209

A comparison of two approaches for generating spatial models of growing season variables for Canada  

Science Journals Connector (OSTI)

This study produced annual spatial models (or grids) of 27 growing season variables for Canada that span two centuries (1901-2100). Temporal gaps in the availability of daily climate data – the typical and preferred source for calculating growing ...

John H. Pedlar; Daniel W. McKenney; Kevin Lawrence; Pia Papadopol; Michael F. Hutchinson; David Price

210

Dynamic Cost-Loss Ratio Decision-making Model with an Autocorrelated Climate Variable  

Science Journals Connector (OSTI)

A dynamic decision-making problem is considered involving the use of information about the autocorrelation of a climate variable. Specifically, an infinite horizon, discounted version of the dynamic cost-loss ratio model is treated, in which only ...

Richard W. Katz

1993-01-01T23:59:59.000Z

211

Magnetic Refrigeration Technology for High Efficiency Air Conditioning  

SciTech Connect

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

Boeder, A; Zimm, C

2006-09-30T23:59:59.000Z

212

Proceedings: commercial refrigeration research workshop. Summary  

SciTech Connect

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

213

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

214

A new framework for the simulation of equation-based models with variable structure  

Science Journals Connector (OSTI)

Many modern models contain changes that affect the structure of their underlying equation system, e.g. the breaking of mechanical devices or the switching of ideal diodes. The modeling and simulation of such systems in current equation-based languages ... Keywords: differential-algebraic equations, equation-based modeling, index reduction, variable-structure systems

Dirk Zimmer

2013-08-01T23:59:59.000Z

215

Limited Dependent Variable Correlated Random Coefficient Panel Data Models  

E-Print Network (OSTI)

for the average slopes of a linear CRC model with a general nonparametric correlation between regressors and random coefficients. I construct a sqrt(n) consistent estimator for the average slopes via varying coefficient regression. The identification of binary...

Liang, Zhongwen

2012-10-19T23:59:59.000Z

216

PhD student in Energy Technology, specifically in Commercial refrigeration systems with CO2 as refrigerant  

E-Print Network (OSTI)

the use of carbon dioxide as refrigerant in supermarket refrigeration systems. The work includes fieldPhD student in Energy Technology, specifically in Commercial refrigeration systems with CO2 a PhD student in Energy Technology, specifically Commercial refrigeration systems with CO2

Kazachkov, Ivan

217

DOE/AHAM advanced refrigerator technology development project  

SciTech Connect

As part of the effort to improve residential energy efficiency and reduce greenhouse emissions from power plants, several design options were investigated for improving the energy efficiency of a conventionally designed domestic refrigerator-freezer. The program goal was to reduce the energy consumption of a 20-ft{sup 3} (570-L) top-mount refrigerator-freeze to 1.00 kWh/d, a 50% reduction from the 1993 National Appliance Energy Conservation Act (NAECA) standard. The options--such as improved cabinet and door insulation, a high-efficiency compressor, a low-wattage fan, a large counterflow evaporator, and adaptive defrost control--were incorporated into prototype refrigerator-freezer cabinets and refrigeration systems. The refrigerant HFC-134a was used as a replacement for CFC-12. The baseline energy performance of the production refrigerator-freezers, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. The project consisted of three main phases: (1) an evaluation of energy-efficient design options using computer simulation models and experimental testing, (2) design and testing of an initial prototype unit, and (3) energy and economic analyses of a final prototype. The final prototype achieved an energy consumption level of 0.93 kWh/d--an improvement of 45% over the baseline unit and 54% over the 1993 NAECA standard for 20-fg{sup 3} (570-L) units. The manufacturer`s cost for those improvements was estimated at $134; assuming that cost is doubled for the consumer, it would take about 11.4 years to pay for the design changes. Since the payback period was thought to be unfeasible, a second, more cost-effective design was also tested. Its energy consumption level was 1.16 kWh/d, a 42% energy savings, at a manufacturer`s cost increase of $53. Again assuming a 100% markup, the payback for this unit would be 6.6 years.

Vineyard, E.A.; Sand, J.R.; Rice, C.K.; Linkous, R.L.; Hardin, C.V.; Bohman, R.H.

1997-03-01T23:59:59.000Z

218

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

SciTech Connect

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

219

Variability in active galactic nuclei: confrontation of models with observations  

Science Journals Connector (OSTI)

......flux. The time-scale of the light variation corresponds to the...However, observations of quasar light curves imply time-scales of...parameter sets to produce simulated light curves from which they can evaluate...had come to be known as the Christmas tree model (Pica Smith 1983......

M.R.S. Hawkins

2002-01-01T23:59:59.000Z

220

Small Commercial Refrigeration Incentive | Department of Energy  

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

Small Commercial Refrigeration Incentive Small Commercial Refrigeration Incentive Small Commercial Refrigeration Incentive < Back Eligibility Agricultural Commercial Industrial Institutional Nonprofit Savings Category Appliances & Electronics Commercial Lighting Lighting Maximum Rebate Incentives over $5,000 must be pre-approved Program Info Funding Source Efficiency Vermont Public Benefit Fund Expiration Date 06/30/2013 State Vermont Program Type State Rebate Program Rebate Amount Outside Air Economizers: $1,250 Evaporator Fan Motors: $20 - $100 Evaporator Fan Motor Controls: $550 Door/Frame Heater Controls: $50 per door Case Light Occupancy Controls: $40 LED Refrigerator and Freezer Case Light Fixtures: $6 - $15 per foot Energy Star Ice Machines: $50 - $75 Efficient Compressors: $200 Display Case Strip-Curtain and Continuous Covers: $6 per foot

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Elastic Metal Alloy Refrigerants: Thermoelastic Cooling  

SciTech Connect

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

None

2010-10-01T23:59:59.000Z

222

Intra-molecular refrigeration in enzymes  

E-Print Network (OSTI)

We present a simple mechanism for intra-molecular refrigeration, where parts of a molecule are actively cooled below the environmental temperature. We discuss the potential role and applications of such a mechanism in biology, in particular in enzymatic reactions.

Hans J. Briegel; Sandu Popescu

2009-12-14T23:59:59.000Z

223

Air Conditioning Heating and Refrigeration Institute Comment  

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

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

224

Refrigerator Manufacturers: Proposed Penalty (2013-CE-5341)  

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

DOE alleged in a Notice of Proposed Civil Penalty that Refrigerator Manufacturers, LLC failed to certify a variety of walk-in cooler or freezer components as compliant with the applicable energy conservation standards.

225

Cospolich Refrigerator: Proposed Penalty (2013-CE-5314)  

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

DOE alleged in a Notice of Proposed Civil Penalty that Cospolich Refrigerator Co, Inc. failed to certify walk-in cooler or freezer components as compliant with the energy conservation standards.

226

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

227

Residential Refrigerator Recycling Ninth Year Retention Study  

E-Print Network (OSTI)

Residential Refrigerator Recycling Ninth Year Retention Study Study ID Nos. 546B, 563 Prepared RECYCLING PROGRAMS Study ID Nos. 546B and 563 Prepared for Southern California Edison Rosemead, California

228

U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical Turk Surveys  

SciTech Connect

Amazon Mechanical Turk was used, for the first time, to collect statistically representative survey data from U.S. households on the presence, number, type and usage of refrigerators, freezers, and various “miscellaneous” refrigeration products (wine/beverage coolers, residential icemakers and non-vapor compression refrigerators and freezers), along with household and demographic information. Such products have been poorly studied to date, with almost no information available about shipments, stocks, capacities, energy use, etc. A total of 9,981 clean survey responses were obtained from five distinct surveys deployed in 2012. General refrigeration product survey responses were weighted to demographics in the U.S. Energy Information Administration’s Residential Energy Consumption Survey 2009 dataset. Miscellaneous refrigeration product survey responses were weighted according to demographics of product ownership found in the general refrigeration product surveys. Model number matching for a portion of miscellaneous refrigeration product responses allowed validation of refrigeration product characteristics, which enabled more accurate estimates of the penetrations of these products in U.S. households. We estimated that there were 12.3±1.0 million wine/beverage coolers, 5.5(–3.5,+3.2) million residential icemakers and 4.4(–2.7,+2.3) million non-vapor compression refrigerators in U.S. households in 2012. (All numerical results are expressed with ranges indicating the 95% confidence interval.) No evidence was found for the existence of non-vapor compression freezers. Moreover, we found that 15% of wine/beverage coolers used vapor compression cooling technology, while 85% used thermoelectric cooling technology, with the vast majority of thermoelectric units having capacities of less than 30 wine bottles (approximately 3.5 cubic feet). No evidence was found for the existence of wine/beverage coolers with absorption cooling technology. Additionally, we estimated that there were 3.6±1.0 million hybrid refrigerator-wine/beverage coolers and 0.9±0.5 million hybrid freezer-wine/beverage coolers in U.S. households. We also obtained estimates of miscellaneous refrigeration product capacities, lifetimes, purchase and installation costs, repair frequencies and costs, and maintenance costs. For wine/beverage coolers, we also obtained information on the penetration of built-in units, AC/DC operating capability, the use of internal lights, and distributions of door opening frequencies. This information is essential to develop detailed estimates of national energy usage and life-cycle costs, and would be helpful in obtaining information on other plug-load appliances. Additional information not highlighted in the main report was presented in Appendices.

Greenblatt, Jeffery B.; Young, Scott J.; Yang, Hung-Chia; Long, Timothy; Beraki, Bereket; Price, Sarah K.; Pratt, Stacy; Willem, Henry; Desroches, Louis-Benoit

2013-11-14T23:59:59.000Z

229

Energy use of US residential refrigerators and freezers: function derivation based on household and climate characteristics  

E-Print Network (OSTI)

residential refrigerators and freezers: function derivationsecond most-used) refrigerators, and freezers, and residualfor more efficient refrigerators and freezers, as well as

Greenblatt, Jeffery

2013-01-01T23:59:59.000Z

230

U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical Turk Surveys  

E-Print Network (OSTI)

vapor compression refrigerators and freezers), along withthe number of refrigerators and freezers in a home alongcompression refrigerators and freezers) in U.S. households.

Greenblatt, Jeffery B.

2013-01-01T23:59:59.000Z

231

Working Fluids Low Global Warming Potential Refrigerants  

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

Working Fluids Low GWP Working Fluids Low GWP Refrigerants - CRADA Ed Vineyard Oak Ridge National Laboratory vineyardea@ornl.gov (865) 574-0576 3 April 2013 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: - High GWP refrigerants increase CO 2 equivalent emissions for HVAC&R equipment - Low GWP alternatives may increase energy consumption, introduce safety risks, require significant modifications to equipment, and have higher costs

232

Working Fluids Low Global Warming Potential Refrigerants  

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

Working Fluids Low GWP Working Fluids Low GWP Refrigerants - CRADA Ed Vineyard Oak Ridge National Laboratory vineyardea@ornl.gov (865) 574-0576 3 April 2013 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: - High GWP refrigerants increase CO 2 equivalent emissions for HVAC&R equipment - Low GWP alternatives may increase energy consumption, introduce safety risks, require significant modifications to equipment, and have higher costs

233

Combined cold compressor/ejector helium refrigerator  

DOE Patents (OSTI)

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Brown, Donald P. (Southold, NY)

1985-01-01T23:59:59.000Z

234

Uninterrupted power supply for autonomous small refrigerators  

Science Journals Connector (OSTI)

The objective of this paper is to describe salient features of a small refrigerator powered by a field of photovoltaic panels backed up by a petrol-start, kerosene-run portable generator set. Such units find applications in medical shops, veterinary applications and storage of vaccines in primary health centers. The modular arrangement allows use of certain components as a part of an uninterrupted power supply system for such refrigerators. Some preliminary results on temperature distributions and performance data are also presented.

Thomachan A. Kattakayam; K. Srinivasan

1998-01-01T23:59:59.000Z

235

ARI delegation to Japan on Alternative Refrigerants  

SciTech Connect

Researchers from ARI member companies spoke at the International Conference on Alternative Refrigerants in Tokyo and visited several Japanese organizations for the purpose of exchanging information on alternative refrigerants. The specific purpose of the meetings was to review the methods being utilized to screen alternatives to CFCs and HCFCs: materials compatibility screening methods, lubricant testing techniques, as well as flammability studies. A list of papers presented at the conference is included.

Not Available

1993-02-01T23:59:59.000Z

236

Combined cold compressor/ejector helium refrigerator  

DOE Patents (OSTI)

A refrigeration apparatus having an ejector operatively connected with a cold compressor to form a two-stage pumping system. This pumping system is used to lower the pressure, and thereby the temperature of a bath of boiling refrigerant (helium). The apparatus as thus arranged and operated has substantially improved operating efficiency when compared to other processes or arrangements for achieving a similar low pressure.

Brown, D.P.

1984-06-05T23:59:59.000Z

237

Energy performance listings: Residential refrigerator/freezers  

SciTech Connect

The Energy Performance Listings series provides comparative information across manufacturers on products. The Refrigerator/Freezers Listings include more than 2900 models that meet or exceed federal standards contained in the Energy Conservation Program for Consumer Products. Information on model energy efficiency levels, performance characteristics, and manufacturer names permits easy selection of top-performing equipment. Each Energy Performance Listing includes an introductory section, two sections of model listings, and an appendix with manufacturer contacts. The first model-listing section presents information in descending order of efficiency for all manufacturers. These efficiency-ordered listings also include banners or symbols to identify voluntary efficiency thresholds for U.S. DOE/U.S. EPA`s Energy Star Program and U.S. DOE`s Federal Energy Management Program (FEMP). Products listed above each banner meet or exceed the efficiency level established by the Energy Star program. All models noted with the symbol meet or exceed FEMP levels. With these listings, users can quickly identify the most efficient product in a particular size range, identify products that meet the efficiency criteria of a specific program, or determine an efficiency threshold that will include a specific number of manufacturers. The second section of model listings presents products grouped by manufacturer and catalog number, allowing users to quickly find and identify performance information on specific models. Energy Performance Listings are tools that support purchasing and procurement by federal, state, and local governments and others, including utility companies, energy interest groups, and research organizations. The listings may be used for program design and planning purposes, equipment selection, specification, and purchasing decisions. The listings are a product of the Energy-Efficient Procurement Collaborative, Inc. and are available through NYSERDA.

NONE

1997-01-01T23:59:59.000Z

238

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

SciTech Connect

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

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

1997-12-01T23:59:59.000Z

239

Modeling of performance behavior in gas condensate reservoirs using a variable mobility concept  

E-Print Network (OSTI)

" representation of the new model (pD(? D) formulation (Eq. 1.5)). Solution is plotted versus the modified Boltzmann transform variable ......................... 8 2 DDD t 1.4 "Type curve" representation of the new model (|rD dpD/drD| formulation (Eq. 1....6)). Solution is plotted versus the modified Boltzmann transform variable ........... 9 2 DDD t 1.5 "Type curve" representation of the new model (tD(? pD/? tD) formulation (Eq. 1.6)). Solution is plotted versus the inverse of the modified Boltzmann...

Wilson, Benton Wade

2004-09-30T23:59:59.000Z

240

Hybrid coupled models of the tropical Paci c |I Interannual variability  

E-Print Network (OSTI)

Hybrid coupled models of the tropical Paci#12;c |I Interannual variability by Youmin Tang 1 University, 251 Mercer Street, New York, NY 10012, USA. Email: ytang@cims.nyu.edu #12; Abstract Two hybrid), hybrid models (e.g., Barnett et al 1993; Balmaseda et al. 1994,1995), and fully coupled general

Hsieh, William

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

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

242

Comparisons of model simulations of climate variability with data, Task 2  

SciTech Connect

Significant progress has been made in our investigations aimed at diagnosing low frequency variations of climate in General Circulation Models. We have analyzed three versions of the Oregon State University General Circulation Model (OSU GCM). These are: (1) the Slab Model in which the ocean is treated as a static heat reservoir of fixed depth, (2) the coupled upper ocean-atmosphere model in which the ocean dynamics are calculated in two layers of variable depths representing the mixed layers and the thermocline; this model is referred to OSU2 in the following discussion, and (3) the coupled full ocean-atmosphere model in which the ocean is represented by six layers of variable depth; this model is referred to as OSU6 GCM in the discussion.

Not Available

1990-01-01T23:59:59.000Z

243

Comparisons of model simulations of climate variability with data, Task 2. [Progress report  

SciTech Connect

Significant progress has been made in our investigations aimed at diagnosing low frequency variations of climate in General Circulation Models. We have analyzed three versions of the Oregon State University General Circulation Model (OSU GCM). These are: (1) the Slab Model in which the ocean is treated as a static heat reservoir of fixed depth, (2) the coupled upper ocean-atmosphere model in which the ocean dynamics are calculated in two layers of variable depths representing the mixed layers and the thermocline; this model is referred to OSU2 in the following discussion, and (3) the coupled full ocean-atmosphere model in which the ocean is represented by six layers of variable depth; this model is referred to as OSU6 GCM in the discussion.

Not Available

1990-12-31T23:59:59.000Z

244

High Efficiency Low Emission Supermarket Refrigeration Research Project |  

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

High Efficiency Low Emission Supermarket High Efficiency Low Emission Supermarket Refrigeration Research Project High Efficiency Low Emission Supermarket Refrigeration Research Project The U.S. Department of Energy (DOE) is currently conducting research into high efficiency, low emission supermarket refrigeration technologies. Project Description The project involves the development of a supermarket refrigeration system that can reduce greenhouse gas emissions and energy consumption when compared to existing systems. The challenge is to design a system that is capable of achieving low refrigerant leak rates while significantly reducing both the energy consumption and the refrigerant charge size. Project Partners Research is being undertaken between DOE and Oak Ridge National Laboratory. Project Goals

245

Recent variability of the solar spectral irradiance and its impact on climate modelling  

E-Print Network (OSTI)

The lack of long and reliable time series of solar spectral irradiance (SSI) measurements makes an accurate quantification of solar contributions to recent climate change difficult. Whereas earlier SSI observations and models provided a qualitatively consistent picture of the SSI variability, recent measurements by the SORCE satellite suggest a significantly stronger variability in the ultraviolet (UV) spectral range and changes in the visible and near-infrared (NIR) bands in anti-phase with the solar cycle. A number of recent chemistry-climate model (CCM) simulations have shown that this might have significant implications on the Earth's atmosphere. Motivated by these results, we summarize here our current knowledge of SSI variability and its impact on Earth's climate. We present a detailed overview of existing SSI measurements and provide thorough comparison of models available to date. SSI changes influence the Earth's atmosphere, both directly, through changes in shortwave (SW) heating and therefore, temp...

Ermolli, I; de Wit, T Dudok; Krivova, N A; Tourpali, K; Weber, M; Unruh, Y C; Gray, L; Langematz, U; Pilewskie, P; Rozanov, E; Schmutz, W; Shapiro, A; Solanki, S K; Woods, T N

2013-01-01T23:59:59.000Z

246

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

247

Shape Changing and Accelerating Solitons in the Integrable Variable Mass Sine-Gordon Model  

SciTech Connect

The sine-Gordon model with a variable mass (VMSG) appears in many physical systems, ranging from the current through a nonuniform Josephson junction to DNA-promoter dynamics. Such models are usually nonintegrable with solutions found numerically or perturbatively. We construct a class of VMSG models, integrable at both the classical and the quantum levels with exact soliton solutions, which can accelerate and change their shape, width, and amplitude simulating realistic inhomogeneous systems at certain limits.

Kundu, Anjan [Theory Group, Saha Institute of Nuclear Physics, Calcutta (India)

2007-10-12T23:59:59.000Z

248

End-Use Load and Consumer Assessment Program: Analysis of residential refrigerator/freezer performance  

SciTech Connect

The Bonneville Power Administration (Bonneville) is conducting a large end-use data acquisition program in an effort to understand how energy is utilized in buildings with permanent electric space heating equipment in the Pacific Northwest. The initial portion of effort, known as the End-Use Load and Consumer Assessment Program (ELCAP), was conducted for Bonneville by the Pacific Northwest Laboratory (PNL). The collection of detailed end-use data provided an opportunity to analyze the amount of energy consumed by both refrigerators and separate freezers units located in residential buildings. By obtaining this information, the uncertainty of long- term regional end-use forecasting can be improved and potential utility marketing programs for new appliances with a reduced overall energy demand can be identified. It was found that standby loads derived from hourly averages between 4 a.m. and 5 a.m. reflected the minimum consumption needed to maintain interior refrigerator temperatures at a steady-state condition. Next, an average 24-hour consumption that included cooling loads from door openings and cooling food items was also determined. Later, analyses were conducted to develop a model capable of predicting refrigerator standby loads and 24-hour consumption for comparison with national refrigerator label ratings. Data for 140 residential sites with a refrigeration end-use were screened to develop a sample of 119 residences with pure refrigeration for use in this analysis. To identify those refrigerators that were considered to be pure (having no other devices present on the circuit) in terms of their end-use classification, the screening procedure used a statistical clustering technique that was based on standby loads with 24-hour consumption. 5 refs., 18 figs., 4 tabs.

Ross, B.A.

1991-09-01T23:59:59.000Z

249

Energy Consumption of Refrigerators in Ghana - Outcomes of Household  

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

Energy Consumption of Refrigerators in Ghana - Outcomes of Household Energy Consumption of Refrigerators in Ghana - Outcomes of Household Surveys Speaker(s): Essel Ben Hagan Date: July 12, 2007 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Robert Van Buskirk Galen Barbose As part of activities to develop refrigerator efficiency standards regulations in Ghana, a national survey on the energy consumption of refrigerators and refrigerator-freezers has been conducted. The survey covered 1000 households in urban, peri-urban and rural communities in various parts of the country. The survey found that, on average, refrigerators and refrigerator-freezers in Ghana use almost three times what is allowed by minimum efficiency standards in the U.S., and a few refrigerators had energy use at levels almost ten times the U.S.

250

Loveland Water and Power - Refrigerator Recycling Program | Department of  

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

Refrigerator Recycling Program Refrigerator Recycling Program Loveland Water and Power - Refrigerator Recycling Program < Back Eligibility Residential Savings Category Appliances & Electronics Maximum Rebate Limit one rebate per account per year Program Info State Colorado Program Type Utility Rebate Program Rebate Amount Refrigerator and Freezer Recycling: $35 Loveland Water and Power is providing an incentive for its customers to recycle their old refrigerators. Interested customers can call the utility to arrange a time to pick up the old refrigerator. The old refrigerator should be brought outside but remain plugged in so the utility can make it is in working condition. the utility will then take the refrigerator to a recycling facility and issue a $35 bill credit. Other Information

251

Refrigerator Standards Save Consumers $ Billions | Department of Energy  

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

Refrigerator Standards Save Consumers $ Billions Refrigerator Standards Save Consumers $ Billions Refrigerator Standards Save Consumers $ Billions March 5, 2013 - 10:35am Addthis Refrigerator Standards Refrigerator Standards Refrigerator technology has come a long way since Dr. John Gorrie (1803 - 1855), a forward-looking inventor, was granted U. S. Patent #8080 for mechanical refrigeration in 1851. In those days, ice was expensive, if it was even available: Blocks of natural ice were carved from frozen lakes and rivers and stored in special warehouses under layers of sawdust for insulation. By the 1890s, pollution and sewage dumping caused by population growth compromised sources of pure, natural ice, threatening the brewing, meat-packing, and dairy industries. As these and other industries sought better solutions, modern refrigeration technology started to evolve.

252

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

253

VEE-0079- In the Matter of Diversified Refrigeration, Inc.  

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

Diversified Refrigeration, Inc. (DRI) requests a six-month exception from the 2001 energy appliance efficiency standards for built-in refrigerators that become effective July 1, 2001. As explained...

254

Fully portable, highly flexible dilution refrigerator systems for neutron scattering  

E-Print Network (OSTI)

775 Fully portable, highly flexible dilution refrigerator systems for neutron scattering P. A systems developed specifically for neutron scattering environ- ments. The refrigerators are completely relatively recently however, the lowest temperatures available in almost all neutron scattering laboratories

Boyer, Edmond

255

Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems  

E-Print Network (OSTI)

This paper presents case studies of two moderately sized ammonia refrigeration systems retrofitted for floating head pressure control. It also presents a parametric analysis to assist in selecting appropriate pressures in an ammonia refrigeration...

Barrer, P. J.; Jones, S. M.

256

DOE Resolves Avanti Refrigerator and Freezer Civil Penalty Case  

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

Today, the Department of Energy announced that it has resolved the civil penalty action against Mackle Company for its failure to certify that refrigerators and refrigerator-freezers sold under the...

257

Of Refrigerators & Regulations | Department of Energy  

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

Of Refrigerators & Regulations Of Refrigerators & Regulations Of Refrigerators & Regulations February 8, 2011 - 9:29am Addthis Jesse Lee White House Director of Online Affairs Editor's Note: This entry has been cross-posted from The White House Blog. For those interested in the President's remarks to the U.S. Chamber of Commerce and his views on the shared responsibilities of government and business to the American people, our post earlier will give a suitable overview. For those interested in the details of the President's Executive Order on reviewing regulations and their impacts on the economy, Cass Sunstein's post this morning will also be of value. But the President also took a moment during his speech to put the debate over regulation in a different perspective, and to break through the false dichotomy so often

258

Thermal links for the implementation of an optical refrigerator  

SciTech Connect

Optical refrigeration has been demonstrated by several groups of researchers, but the cooling elements have not been thermally linked to realistic heat loads in ways that achieve the desired temperatures. The ideal thermal link will have minimal surface area, provide complete optical isolation for the load, and possess high thermal conductivity. We have designed thermal links that minimize the absorption of fluoresced photons by the heat load using multiple mirrors and geometric shapes including a hemisphere, a kinked waveguide, and a tapered waveguide. While total link performance is dependent on additional factors, we have observed net transmission of photons with the tapered link as low as 0.04%. Our optical tests have been performed with a surrogate source that operates at 625 nm and mimics the angular distribution of light emitted from the cooling element of the Los Alamos solid state optical refrigerator. We have confirmed the optical performance of our various link geometries with computer simulations using CODE V optical modeling software. In addition we have used the thermal modeling tool in COMSOL MULTIPHYSICS to investigate other heating factors that affect the thermal performance of the optical refrigerator. Assuming an ideal cooling element and a nonabsorptive dielectric trapping mirror, the three dominant heating factors are (1) absorption of fluoresced photons transmitted through the thermal link, (2) blackbody radiation from the surrounding environment, and (3) conductive heat transfer through mechanical supports. Modeling results show that a 1 cm{sup 3} load can be chilled to 107 K with a 100 W pump laser. We have used the simulated steady-state cooling temperatures of the heat load to compare link designs and system configurations.

Epsteiin, Richard I [Los Alamos National Laboratory; Greenfield, Scott R [Los Alamos National Laboratory; Parker, John [HARVEY MUDD COLLEGE; Mar, David [HARVEY MUDD GOLLEGE; Von Der Porten, Steven [HARVEY MUDD COLLEGE; Hankinson, John [HARVEY MUDD COLLEGE; Byram, Kevin [HARVEY MUDD COLLEGE; Lee, Chris [HARVEY MUDD COLLEGE; Mayeda, Kai [HARVEY MUDD COLLEGE; Haskell, Richard [HARVEY MUDD COLLEGE; Yang, Qimin [HARVEY MUDD COLLEGE

2008-01-01T23:59:59.000Z

259

Review and comparison of methods to study the contribution of variables in artificial neural network models  

E-Print Network (OSTI)

, Greece Abstract Convinced by the predictive quality of artificial neural network (ANN) models in ecology. # 2002 Published by Elsevier Science B.V. Keywords: Artificial neural networks; Backpropagation; NonReview and comparison of methods to study the contribution of variables in artificial neural

Lek, Sovan

260

Population Pharmacokinetics of Rifampin in Pulmonary Tuberculosis Patients, Including a Semimechanistic Model To Describe Variable Absorption  

Science Journals Connector (OSTI)

...gastric emptying occurs, resulting in rapid uptake from the duodenum. However...conclude that the model is suitable for simulation using patient populations similar to...as long as it is borne in mind that simulations may overemphasize variability to a small...

Justin J. Wilkins; Radojka M. Savic; Mats O. Karlsson; Grant Langdon; Helen McIlleron; Goonaseelan Pillai; Peter J. Smith; Ulrika S. H. Simonsson

2008-04-07T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid  

E-Print Network (OSTI)

Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy turbine technology has undergone rapid developments. Growth in size and the optimization of wind turbines

Hansen, René Rydhof

262

Symbolic Variable Elimination for Discrete and Continuous Graphical Models Scott Sanner  

E-Print Network (OSTI)

Symbolic Variable Elimination for Discrete and Continuous Graphical Models Scott Sanner NICTA & ANU, e.g., estimating the position and pose of entities from measurements in robotics, or radar track Intelligence (www.aaai.org). All rights reserved. n xx1 ...x2 d 10 d 0 100 P(d) = P(x |d) = d x i i Figure 1

Sanner, Scott

263

Optimized regional and interannual variability of lightning in a global chemical transport model constrained  

E-Print Network (OSTI)

to remove their diurnal sampling bias, we construct a monthly time series of lightning flash rates for 1998, D20307, doi:10.1029/2012JD017934. 1. Introduction [2] The extreme heat in a lightning flash channelOptimized regional and interannual variability of lightning in a global chemical transport model

Jacob, Daniel J.

264

Sequential Thermo-Hydraulic Modeling of Variably Saturated Flow in High-Level Radioactive Waste Repository  

E-Print Network (OSTI)

Sequential Thermo-Hydraulic Modeling of Variably Saturated Flow in High-Level Radioactive Waste long-lived radioactive wastes must be managed in a safe way for human health and for the environment. That is the raison why the French agency for the management of radioactive waste (ANDRA) is engaged to study

Boyer, Edmond

265

Simplified Modelling and Control of a Synchronous Machine with VariableSpeed SixStep Drive  

E-Print Network (OSTI)

of electrical power flow in the machine. Cost is a driving factor in the design of such a system, and the power frequency than PWM as well. II. VARIABLE­SPEED ELECTRIC MACHINE DRIVES While the choice of driveSimplified Modelling and Control of a Synchronous Machine with Variable­Speed Six­Step Drive

Sanders, Seth

266

BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha Karhunen  

E-Print Network (OSTI)

BUILDING BLOCKS FOR HIERARCHICAL LATENT VARIABLE MODELS Harri Valpola, Tapani Raiko and Juha, Espoo, Finland E­mail: {Harri.Valpola, Tapani.Raiko, Juha.Karhunen}@hut.fi URL: http; and the approximation of the true posterior p(#18; j X) by q(#18;). The cost function C used in ensemble learning is C

Karhunen, Juha

267

Modeling and Generating Daily Changes in Market Variables Using A Multivariate Mixture of Normal Distributions  

E-Print Network (OSTI)

Modeling and Generating Daily Changes in Market Variables Using A Multivariate Mixture of Normal Distributions Jin Wang Department of Mathematics and Computer Science Valdosta State University Valdosta, GA 31698-0040 January 28, 2000 Abstract The mixture of normal distributions provides a useful extension

Wang, Jin

268

Control of surface gravity waves by variable fluid injection in a model of a copper  

E-Print Network (OSTI)

Control of surface gravity waves by variable fluid injection in a model of a copper converter splashing appears in copper converters when air is injected into the molten matte in order to carry out to the opposite extreme to where the nozzle injection is placed. Key words: Copper converter, gravity waves

Osses, Axel

269

Modelled and observed variability of the atmospheric circulation the Peruvian Current System: 2000-2005  

E-Print Network (OSTI)

on the characteristics of the local equatorward atmospheric circulation. Resolving the mesoscale variability of the heat Mesoscale Model (MM5) and Weather Research and Forecasting (WRF) that were run over the Peruvian Current System (PCS) [0N-19°S; 83°W-68°W] from November 2000- October 2005. Wind data as derived from

270

ENVIRONMENTAL ASSESSMENT FOR THE PROPOSED ENERGY CONSERVATION STANDARD FOR REFRIGERATORS, REFRIGERATOR-  

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

ASSESSMENT FOR THE PROPOSED ENERGY ASSESSMENT FOR THE PROPOSED ENERGY CONSERVATION STANDARD FOR REFRIGERATORS, REFRIGERATOR- , AND FREEZERS - 1. INTRODUCTION AND NEED FOR PROPOSED ACTION ental Assessment (EA) on the candidate energy conservation stand licy Act. of 1969 (NEPA), regulations of the Council on Environmentd Qu refrigerators, re€iigerator-freezers, and freezers was prepared pursuant to the National ' ederal Regulations, Parts 1500 through. 1508. The proposed energy conservation standard (Level 1) and the alternative standards are being reviewed in an energy- efficiency standards rulemaking that the Department has undertaken pursuant to the Energy Policy and Conservation Act, as amended by the National Energy Conservation Policy Act and the National Appliance Energy Consehation Act

271

Retrofitting Doors on Open Refrigerated Cases  

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

Retrofitting Doors on Open Retrofitting Doors on Open Refrigerated Cases William Goetzler Navigant Consulting, Inc. wgoetzler@navigant.com (781) 270-8351 April 4, 2013 BBA Refrigeration Project Team Images courtesy of REMIS AMERICA, LLC. 2 | Building Technologies Office eere.energy.gov Technology Overview Image from Investigation of Energy- Efficient Supermarket Display Cases. 2004, Oak Ridge National Laboratory. Background and Motivation * Adding doors to open cases (retrofits) greatly reduces cold air loss - 50-80% load reduction - Load reduction = system energy savings

272

Development of a prototype optical refrigerator  

SciTech Connect

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

273

Phase boundary detection for dilution refrigerators  

SciTech Connect

We describe a device to conveniently measure the positions of the phase boundaries in a dilution refrigerator. We show how a simple modification of a standard capacitive level gauge (segmentation of one of the electrodes) permits a direct calibration of the capacitance versus phase boundary position. We compare this direct calibration with the indirect procedure that must be adopted for a conventional capacitive level gauge. The device facilitates the correct adjustment of the {sup 3}He/{sup 4}He fraction in the dilution refrigerator.

Haar, E. ter; Martin, R.V. [DFMT, Instituto de Fisica, Universidade de Sao Paulo, C.P. 66.318, 05315-970 Sao Paulo, SP (Brazil)

2004-09-01T23:59:59.000Z

274

Helium refrigeration considerations for cryomodule design  

SciTech Connect

Many of the present day accelerators are based on superconducting radio frequency (SRF) cavities, packaged in cryo-modules (CM), which depend on helium refrigeration at sub-atmospheric pressures, nominally 2 K. These specialized helium refrigeration systems are quite cost intensive to produce and operate. Particularly as there is typically no work extraction below the 4.5-K supply, it is important that the exergy loss between this temperature level and the CM load temperature(s) be minimized by the process configuration choices. This paper will present, compare and discuss several possible helium distribution process arrangements to support the CM loads.

Ganni, V.; Knudsen, P. [Thomas Jefferson National Accelerator Facility (JLab), Newport News, VA 23606 (United States)

2014-01-29T23:59:59.000Z

275

Pipeline gas pressure reduction with refrigeration generation  

SciTech Connect

The high pressure of pipeline gas is reduced to the low pressure of a distribution system with simultaneous generation of refrigeration by passing the gas through two successive centrifugal compressors driven by two turbo-expanders in which the compressed gas is expanded to successively lower pressures. Refrigeration is recovered from the gas as it leaves each turbo-expander. Methanol is injected into the pipeline gas before it is expanded to prevent ice formation. Aqueous methanol condensate separated from the expanded gas is distilled for the recovery and reuse of methanol.

Markbreiter, S. J.; Schorr, H. P.

1985-06-11T23:59:59.000Z

276

Reducing the Carbon Footprint of Commercial Refrigeration Systems Using Life Cycle Climate Performance Analysis: From System Design to Refrigerant Options  

SciTech Connect

In this paper, Life Cycle Climate Performance (LCCP) analysis is used to estimate lifetime direct and indirect carbon dioxide equivalent gas emissions of various refrigerant options and commercial refrigeration system designs, including the multiplex DX system with various hydrofluorocarbon (HFC) refrigerants, the HFC/R744 cascade system incorporating a medium-temperature R744 secondary loop, and the transcritical R744 booster system. The results of the LCCP analysis are presented, including the direct and indirect carbon dioxide equivalent emissions for each refrigeration system and refrigerant option. Based on the results of the LCCP analysis, recommendations are given for the selection of low GWP replacement refrigerants for use in existing commercial refrigeration systems, as well as for the selection of commercial refrigeration system designs with low carbon dioxide equivalent emissions, suitable for new installations.

Fricke, Brian A [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL; Vineyard, Edward Allan [ORNL] [ORNL

2013-01-01T23:59:59.000Z

277

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

278

Feasibility of Solar-Assisted Refrigerated Transport in Australia  

E-Print Network (OSTI)

systems. Keywords: refrigeration, transport, photovoltaics, economics. 1 #12;B. Elliston, M. Dennis) modules to minimise the use of diesel generation in refrigerated transport. Sub- sequently, UK supermarket. This report investigates the merit of retrofitting a PV system to assist refrigerated trailers in Australian

279

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

280

EPA's research projects relating to the dual-circuit and Lorenz refrigerator/freezers  

SciTech Connect

The paper discusses EPA research projects relating to the dual-circuit and Lorenz refrigerator/freezers (RFs). EPA is interested in not only phasing out chlorofluorocarbons (CFCs) in RFs, but doing so in a way that will maximize energy efficiency and minimize subsequent impacts on the greenhouse effect. An early decision was made to concentrate on replacing fully halogenated CFCs in RFs during the first year of EPA's research. RFs were chosen because they are small, require small quantities of refrigerants, are relatively easy to modify and test, and are the most energy-consumptive appliances in most U.S. households. In the future, other applications are expected to receive more attention. The first year of EPA's program has concentrated on implementing two alternative configurations of RFs which are believed to have the potential to make RFs more energy efficient: the dual-circuit and the Lorenz RFs. Research has included modeling alternative refrigerants and Non-azeotropic Refrigerant Mixtures (NARMs) in the dual-circuit and Lorenz configurations and experimental testing of modified RFs and refrigeration components in test stands.

Bare, J.C.

1992-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

2014-04-10 Issuance: Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers; Final Rule  

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

This document is a pre-publication Federal Register final rule regarding test procedures for residential refrigerators and freezers, as issued by the Deputy Assistant Secretary for Energy Efficiency on April 10, 2014.

282

Evaluation of design options for improving the energy efficiency of an environmentally safe domestic refrigerator-freezer  

SciTech Connect

In order to reduce greenhouse emissions from power plants and respond to regulatory actions arising from the National Appliance Energy Conservation Act (NAECA), several design options were investigated for improving the energy efficiency of a conventionally designed, domestic refrigerator-freezer. The options, such as improved cabinet insulation and high-efficiency compressor and fans, were incorporated into a prototype refrigerator-freezer cabinet and refrigeration system to produce a unit that is superior from an environmental viewpoint due to its lower energy consumption and the use of refrigerant HFC-134a as a replacement for CFC-12. Baseline energy performance of the original 1993 production refrigerator-freezer, along with cabinet heat load and compressor calorimeter test results, were extensively documented to provide a firm basis for experimentally measured energy savings. A detailed refrigerator system computer model was used to evaluate the energy savings for several design modifications that, collectively, could achieve a targeted energy consumption of 1.00 kWh/d for a 20 ft{sup 3} (570 l) top-mount, automatic-defrost, refrigerator-freezer. The energy consumption goal represents a 50% reduction in the 1993 NAECA standard for units of this size. Following the modeling simulation, laboratory prototypes were fabricated and tested to experimentally verify the analytical results and aid in improving the model in those areas where discrepancies occurred. While the 1.00 kWh/d goal was not achieved with the modifications, a substantial energy efficiency improvement of 22% (1.41 kWh/d) was demonstrated using near-term technologies. It is noted that each improvement exacts a penalty in terms of increased cost or system complexity/reliability. Further work on this project will analyze cost-effectiveness of the design changes and investigate alternative, more-elaborate, refrigeration system changes to further reduce energy consumption.

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

1995-03-01T23:59:59.000Z

283

A cryogenic axial-centrifugal compressor for superfluid helium refrigeration  

E-Print Network (OSTI)

CERN's new project, the Large Hadron Collider (LHC), will use superfluid helium as coolant for its high-field superconducting magnets and therefore require large capacity refrigeration at 1.8 K. This may only be achieved by subatmospheric compression of gaseous helium at cryogenic temperature. To stimulate development of this technology, CERN has procured from industry prototype Cold Compressor Units (CCU). This unit is based on a cryogenic axial-centrifugal compressor, running on ceramic ball bearings and driven by a variable-frequency electrical motor operating under low-pressure helium at ambient temperature. The machine has been commissioned and is now in operation. After describing basic constructional features of the compressor, we report on measured performance.

Decker, L; Schustr, P; Vins, M; Brunovsky, I; Lebrun, P; Tavian, L

1997-01-01T23:59:59.000Z

284

COSSOR—a transient simulation program for a solid absorption solar refrigerator  

Science Journals Connector (OSTI)

An algorithm for the computer simulation of a solid absorption solar refrigerator, COSSOR, is presented. The algorithm is based on a detailed transient mathematical model of the system. It is a sequential modular program which consists of a relatively short main program and about 50 subprograms which are called by name by the main program or other subprograms. The program is coded in QBASIC, is highly flexible, accurate and fast, and has been tested on a wide variety of personal computers. Predictions of the refrigerator performance obtained using COSSOR compare very well with experimental data over a wide range of operating conditions. It is therefore a useful tool for computer aided design, performance prediction and analysis of the refrigerator, and may find applications in other solar thermal systems. Typical predicted results for some stations are given.

S.O. Enibe; O.C. Iloeje

2000-01-01T23:59:59.000Z

285

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

286

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

287

Waste Heat Recapture from Supermarket Refrigeration Systems  

SciTech Connect

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

288

Alternative Refrigerants for Building Air Conditioning  

E-Print Network (OSTI)

The majority of building air conditioning has traditionally been achieved with vapor compression technology using CFC-I I or HCFC-22 as refrigerant fluids. CFC-11 is being successfully replaced by HCFC-123 (retrofit or new equipment) or by HFC- 134a...

Bivens, D. B.

1996-01-01T23:59:59.000Z

289

Covered Product Category: Refrigerated Beverage Vending Machines  

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

FEMP provides acquisition guidance and Federal efficiency requirements across a variety of product categories, including refrigerated beverage vending machines, which are covered by the ENERGY STAR® program. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

290

International Refrigeration: Proposed Penalty (2012-CE-1510) | Department  

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

International Refrigeration: Proposed Penalty (2012-CE-1510) International Refrigeration: Proposed Penalty (2012-CE-1510) International Refrigeration: Proposed Penalty (2012-CE-1510) July 9, 2012 DOE alleged in a Notice of Proposed Civil Penalty that International Refrigeration Products failed to certify a various room air conditioners as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. International Refrigeration: Proposed Penalty (2012-CE-1510) More Documents & Publications

291

Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems  

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

This case study documents one year of operating experience with a transcritical carbon dioxide (TC CO2) booster refrigeration system at Delhaize America’s Hannaford supermarket location in Turner, Maine. This supermarket, which began operation in June 2013, is the first supermarket installation in the U.S. of a TC CO2 booster refrigeration system. We compare refrigeration system performance to that for a supermarket having nearly identical layout and refrigeration loads, in a similar climate and of similar vintage, that uses a conventional hydrofluorocarbon (HFC) refrigerant. Delhaize provided the submetered and utility data used to generate the performance summaries herein.

292

Special dilution refrigerator systems of Milli-Kelvin detector experiments  

SciTech Connect

Several hundred ultra low temperature systems have been designed and built for a variety of applications. One common application is the refrigeration of low temperature detectors. Although many of the requirements are satisfied by standard designs, Oxford Instruments has often built special refrigerators to suit specific detector requirements. A few of the most interesting of these systems will be discussed. (1) dilution refrigerators to cool gravitational wave antennae to 65 mK; (2) rotating dilution refrigerator for cosmic ray detector experiments; (3) compact dilution refrigerator to cool large bolometer arrays within the SCUBA telescope; (4) side access systems for beam line experiments

Batey, G.; Balshaw, N. (Oxford Instruments Ltd., Old Station Way (United Kingdom))

1993-11-01T23:59:59.000Z

293

Solid-vapor adsorption refrigeration system development. Final report, October 1987-September 1988  

SciTech Connect

The report describes the feasibility study of several gas-fired refrigeration cycles using ammoniated complex compounds as the working media. The cycles take advantage of the coordinative characteristic of complex compound ligand bonds which result in large coordination spheres with only one degree of freedom. The coordinative bond yields refrigerant concentration plateaus of constant pressure, which in turn result in high thermal-cycle efficiencies and eliminate electrical parasitics and the requirement for moving parts. Media properties of known complex compound materials were verified with respect to vapor-pressure equilibria, coordination properties, and thermal stability. An existing computer model was used to predict heat balances and coefficients of performance.

Rockenfeller, U.

1988-10-01T23:59:59.000Z

294

Retail refrigeration systems -- The use of ammonia and two-level secondary refrigeration  

SciTech Connect

The concept of a secondary refrigeration system for high-temperature use as investigated in 1991, and a design for a full high-temperature system was completed the following year. In late 1992, a supermarket chain commissioned a study of the feasibility of turning the design into a practical application and assisted the project in 1993 by commissioning a test facility for single-temperature secondary refrigeration at one of the company`s factory sites. Results and conclusions from this trial work pointed toward the need for a total secondary refrigeration system, including a low-temperature system for frozen food display cases, and the possibility of utilizing environmentally friendly ammonia as the primary refrigerant. Therefore, in late 1993/early 1994, a low-temperature system was developed and commissioned at the test facility. Full collaboration between the supermarket company and the contractor resulted in the funding of practical trial work and feasibility studies for both secondary refrigeration and a fully detailed proposal for the use of ammonia in a public retail environment. In May 1995, the first UK ammonia and two-level secondary refrigeration system began operation in a supermarket in Horsham, Sussex England.

Thomas, A.S. [Westward Refrigeration, Gloucester (United Kingdom)

1998-10-01T23:59:59.000Z

295

Building Technologies Office: Low-Global Warming Potential Refrigerants  

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

Low-Global Warming Low-Global Warming Potential Refrigerants Research Project to someone by E-mail Share Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on Facebook Tweet about Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on Twitter Bookmark Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on Google Bookmark Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on Delicious Rank Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on Digg Find More places to share Building Technologies Office: Low-Global Warming Potential Refrigerants Research Project on AddThis.com... About Take Action to Save Energy

296

Energy efficiency improvements for refrigerator/freezers using prototype doors containing gas-filled panel insulating systems  

SciTech Connect

Energy efficiency improvements in domestic refrigerator/freezers, are directly influenced by the overall thermal performance of the cabinet and doors. An advanced system for reducing heat gain is Gas-Filled Panel thermal insulation technology. Gas-Filled Panels contain a low-conductivity, inert gas at atmospheric pressure and employ a reflective baffle to suppress radiation and convection within the gas. This paper presents energy use test results for a 1993 model 500 liter top mount refrigerator/freezer operated with its original doors and with a series of alternative prototype doors. Gas-Filled Panel technology was used in two types of prototype refrigerator/freezer doors. In one design, panels were used in composite with foam in standard metal door pans; this design yielded no measurable energy savings. In the other design, special polymer door pans were fitted with panels that fill nearly all of the available insulation volume; this design yielded a 6.5% increase in energy efficiency for the entire refrigerator/freezer. The EPA Refrigerator Analysis computer program has been used to predict the change in daily energy consumption with the alternative doors. The computer model also projects a 25% energy efficiency improvement for a refrigerator/freezer that would use Gas-Filled Panel insulation throughout the cabinet as well as the doors.

Griffith, B.; Arasteh, D.; Tuerler, D.

1995-01-01T23:59:59.000Z

297

Connecting Atlantic temperature variability and biological cycling in two earth system models  

Science Journals Connector (OSTI)

Abstract Connections between the interdecadal variability in North Atlantic temperatures and biological cycling have been widely hypothesized. However, it is unclear whether such connections are due to small changes in basin-averaged temperatures indicated by the Atlantic Multidecadal Oscillation (AMO) Index, or whether both biological cycling and the AMO index are causally linked to changes in the Atlantic Meridional Overturning Circulation (AMOC). We examine interdecadal variability in the annual and month-by-month diatom biomass in two Earth System Models with the same formulations of atmospheric, land, sea ice and ocean biogeochemical dynamics but different formulations of ocean physics and thus different AMOC structures and variability. In the isopycnal-layered ESM2G, strong interdecadal changes in surface salinity associated with changes in AMOC produce spatially heterogeneous variability in convection, nutrient supply and thus diatom biomass. These changes also produce changes in ice cover, shortwave absorption and temperature and hence the AMO Index. Off West Greenland, these changes are consistent with observed changes in fisheries and support climate as a causal driver. In the level-coordinate ESM2M, nutrient supply is much higher and interdecadal changes in diatom biomass are much smaller in amplitude and not strongly linked to the AMO index.

Anand Gnanadesikan; John P. Dunne; Rym Msadek

2014-01-01T23:59:59.000Z

298

The alternative refrigerant dilemma for refrigerator-freezers: Truth or consequences  

SciTech Connect

In an effort to select a refrigerant that has minimal impact on energy consumption and the environment, a screening analysis of potential refrigerants was performed that resulted in the selection of six candidates. The screening results show that R-134a, R-134, R-152a, R-134a/R-152a, R-22/R-152a/R-124, and R-134a/R-152a/R-124 are the most promising refrigerants based on the following criteria: ozone depletion potential, greenhouse warming potential, coefficient of performance, and safety. Energy consumption tests were performed for the three pure refrigerants in accordance with the Association of Home Appliance Manufacturers standard for household refrigerators and household freezers. The results indicate an increased energy consumption of 6.8%, 7.3%, and 7.3%, respectively for R-134, R-152a, and R-134a in the most efficient oil. However, when the effects of compressor efficiency are taken into account, the normalized energy consumption results in an increase of only 2.7% for R-152a and 5.5% for both R-134a and R-134. 14 refs., 5 tabs.

Vineyard, E.A.

1991-01-01T23:59:59.000Z

299

International Refrigeration: Order (2012-CE-1510)  

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

WASHINGTON, D.C. 20585 WASHINGTON, D.C. 20585 Case Number: 2012-CE-1510 International Refrigeration Products, Respondent ) ) ) ) ) ) ORDER Issued: July 20, 2012 By the General Counsel, U.S. Department of Energy: 1. In this Order, I adopt the attached Compromise Agreement entered into between the U.S. Department of Energy ("DOE") and International Refrigeration Products ("Respondent"). The Compromise Agreement resolves the case initiated to pursue a civil penalty for violations of the compliance certification requirements located at 10 C.P.R. § 429.12. 2. DOE and Respondent have negotiated the terms of the Compromise Agreement that resolve this matter. A copy of the Compromise Agreement is attached hereto and incorporated by reference. 3. After reviewing the terms of the Compromise Agreement and evaluating the facts

300

An electric utility's adventures in commercial refrigeration  

SciTech Connect

This article provides a look at the history of energy conservation efforts in supermarket refrigeration from World War II to the present and a goal for the future. A supermarket is a low profit margin business, typically netting 1 percent on annual sales. The typical supermarket's annual electric bill equals or exceeds the annual profits. With all of these data, it looked like energy conservation in the supermarket industry was going to be an easy task. Change the lighting to a more energy-efficient system and lower the head pressure and raise the suction pressure in the refrigeration. Any owner, CEO, or general manager who could easily increase his bottom-line profit by 10 to 30 percent would jump at the opportunity, especially when the electric utility was willing to support a portion of the cost for the changes.

Flannick, J.A. (Wisconsin Electric Co., Milwaukee, WI (United States)); Stamm, R.H. (Industrial Refrigeration, Sandy, OR (United States)); Calle, M.M. (Technical Resources, Inc., Milwaukee, WI (United States)); Gomolla, J.C. (Gomolla (Jerry C.), Milwaukee, WI (United States))

1994-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Process for the production of refrigerator oil  

SciTech Connect

A process for producing a high quality refrigerator oil from an oil fraction boiling at a temperature within boiling point of lubricating oil by contacting said oil fraction with a solvent to extract undesirable components thereby lowering % C..cap alpha.. of said oil fraction, hydrogenating said solvent extracted fraction under the specific conditions, and then contacting said hydrogenated oil with a solid absorbant to remove impurities; said oil fraction being obtained from a low grade naphthenic crude oil.

Kunihiro, T.; Tsuchiya, K.

1985-06-04T23:59:59.000Z

302

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

303

Cool energy savings opportunities in commercial refrigeration  

SciTech Connect

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

304

Could You Save Money on Your Refrigerator? | Department of Energy  

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

Could You Save Money on Your Refrigerator? Could You Save Money on Your Refrigerator? Could You Save Money on Your Refrigerator? July 20, 2012 - 4:35pm Addthis Earlier this week, Amanda wrote about how you can save energy by choosing the right refrigerator and using it efficiently. These tips explain all sorts of ways you can ensure your refrigerator uses as little energy as possible to keep itself cool. So this week, we're curious: Could you save money with your refrigerator? You have the chance to share your thoughts on a question about energy efficiency or renewable energy for consumers. E-mail your responses to the Energy Saver team at consumer.webmaster@nrel.gov. Addthis Related Articles How Do You Save Money on Summer Holidays? Have You Seen Energy Efficiency Improvements in Your Neighborhood?

305

Could You Save Money on Your Refrigerator? | Department of Energy  

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

Could You Save Money on Your Refrigerator? Could You Save Money on Your Refrigerator? Could You Save Money on Your Refrigerator? July 20, 2012 - 4:35pm Addthis Earlier this week, Amanda wrote about how you can save energy by choosing the right refrigerator and using it efficiently. These tips explain all sorts of ways you can ensure your refrigerator uses as little energy as possible to keep itself cool. So this week, we're curious: Could you save money with your refrigerator? You have the chance to share your thoughts on a question about energy efficiency or renewable energy for consumers. E-mail your responses to the Energy Saver team at consumer.webmaster@nrel.gov. Addthis Related Articles How Do You Save Money on Summer Holidays? Have You Seen Energy Efficiency Improvements in Your Neighborhood?

306

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

307

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

308

Process Options for Nominal 2-K Helium Refrigeration System Designs  

SciTech Connect

Nominal 2-K helium refrigeration systems are frequently used for superconducting radio frequency and magnet string technologies used in accelerators. This paper examines the trade-offs and approximate performance of four basic types of processes used for the refrigeration of these technologies; direct vacuum pumping on a helium bath, direct vacuum pumping using full or partial refrigeration recovery, cold compression, and hybrid compression (i.e., a blend of cold and warm sub-atmospheric compression).

Peter Knudsen, Venkatarao Ganni

2012-07-01T23:59:59.000Z

309

Hydrophilic structures for condensation management in refrigerator appliances  

DOE Patents (OSTI)

A refrigerator appliance that includes a freezer compartment having a freezer compartment door, and a refrigeration compartment having at least one refrigeration compartment door. The appliance further includes a mullion with an exterior surface. The mullion divides the compartments and the exterior surface directs condensation toward a transfer point. The appliance may also include a cabinet that houses the compartments and has two sides, each with an exterior surface. Further, at least one exterior surface directs condensation toward a transfer point.

Kuehl, Steven John; Vonderhaar, John J; Wu, Guolian; Wu, Mianxue

2014-10-21T23:59:59.000Z

310

Microcomputer Software for Refrigerant Property and Cycle Analysis Calculations  

E-Print Network (OSTI)

cost, a large component of which is energy-related. Existing system operation must be analyzed to optimize energy consumption while still meeting cooling load requirements. Refrigerant properties, which form the basis for such calculations, have... to illustrate the application of the program to problems in design and operation of refrigeration systems. INTRODUCTION Thermodynamic analysis of refrigeration systems is important in a variety. of industrial; commercial, and building-related applications...

Bierschenk, J. L.; Strohl, S. T.; Schmidt, P. S.

311

Helium Refrigerator Design for Pulsed Heat Load in Tokamaks  

SciTech Connect

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

312

Supermarket refrigeration assessment for the New England Electric System  

SciTech Connect

The Electric Power Research Institute (EPRI) has undertaken a project to assess the impact of energy efficient supermarket refrigeration on the electric capacity requirements of the New England Electric System (NEES) service territories. The leading supermarket chains in the NEES service territories were contacted and the number of supermarkets and the types of refrigeration systems employed were established. Estimates were then made of the potential demand and energy savings that NEES and the supermarkets could realize if energy efficient refrigeration systems were employed. On the basis of this analysis, possible incentives to accelerate the implementation of energy efficient refrigeration equipment in NEES service territories were recommended. 4 refs., 10 figs., 27 tabs.

Tsaros, T.L.; Walker, D.H. (Foster-Miller, Inc., Waltham, MA (United States))

1991-07-01T23:59:59.000Z

313

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

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

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

314

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

315

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

316

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

317

South Africa Sectoral Study on Climate and Refrigeration Technology...  

Open Energy Info (EERE)

Reduction Potential and Implementing NAMAs Jump to: navigation, search Name South Africa-Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the...

318

Polyhalogenated hydrocarbon refrigerants and refrigerant oils colored with fluorescent dyes and method for their use as leak detectors  

SciTech Connect

A leak detectable refrigeration composition is described comprising: (A) a refrigeration liquid selection from the group consisting of: (1) a polyhalogenated hydrocarbon refrigerant; (2) a refrigeration oil selected from the group consisting of naphthenic oils, paraffinic oils, alkylated benzenes, silicones, polyglycols, diesters or triesters of dicarboxylic or tricarboxylic acids, and polyalkyl silicate oils, and (3) a mixture of A(1) and A(2), and (B) a fluorescent dye compound or composition comprising the dye selected from the group consisting of: (1) a fluorescent dye selected from the group consisting of perylene, naphthoxanthene, monocyclic aromatic compounds having an organometallic compound, (2) a solution of fluorescent dye in a solvent, and (3) a mixture of B(1) and B(2). The fluorescent dye compound or composition is soluble in the refrigeration liquid. The concentration of the dye being at least 0.001 grams per 100 grams of the refrigeration liquid.

Parekh, M.

1988-07-19T23:59:59.000Z

319

Exergy analysis and experimental study of a vapor compression refrigeration cycle  

Science Journals Connector (OSTI)

This article presents a detailed experimental analysis of 2TR (ton of refrigeration) vapor compression refrigeration cycle for different percentage of refrigerant charge using exergy analysis. An experimental set...

S. Anand; S. K. Tyagi

2012-11-01T23:59:59.000Z

320

Field test of a high efficiency, automatic defrost refrigerator-freezer  

SciTech Connect

This paper describes the market evaluation and field test portion of a program to design, develop, and demonstrate a high efficiency, automatic defrosting refrigerator-freezer for the residential market. After the successful completion of Phase I of the program, which concentrated on the design, construction, and laboratory testing of a 453 1 (16 ft/sup 3/) high-efficiency refrigerator-freezer prototype, Phase II was initiated in February 1979 to evaluate the sales potential and performance of the high-efficiency refrigerator concept under field conditions, as a necessary step in creating a product that was both manufacturable and marketable. In Phase I, a survey of food consumption and storage trends, family size, and consumer buying habits led to a sales-weighted average-capacity forecast for 1985 of approximately 453 1 (16 ft/sup 3/) and identification of the top-mount, automatic defrosting refrigerator as the projected sales leader. To meet this market demand, a 453 1 (16 ft/sup 3/) top-mount was selected as the baseline for the Phase I design and development. In Phase II, a 509 1 (18 ft/sup 3/) unit using Phase I technology was chosen for the field test, since the slightly larger model better fit the participating manufacturer's new product development efforts and market.

Topping, R.F.; Vineyard, E.A.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Hierarchical Modeling of Variability in Regional Climate Models Using Markov Random Fields  

E-Print Network (OSTI)

ensembles, are used to explore the uncertainties associated with projections of climate change (ANOVA), climate model ensembles, un- certainty quantification. 1 Geophysical Statistics Project the Earth's climate and producing projections of climate change. They encapsulate an entire field

Kaufman, Cari

322

The New York Power Authority`s energy-efficient refrigerator program for the New York City Housing Authority -- 1997 savings evaluation  

SciTech Connect

This document describes the estimation of the annual energy savings achieved from the replacement of 20,000 refrigerators in New York City Housing Authority (NYCHA) public housing with new, highly energy-efficient models in 1997. The US Department of Housing and Urban Development (HUD) pays NYCHA`s electricity bills, and agreed to reimburse NYCHA for the cost of the refrigerator installations. Energy savings over the lifetime of the refrigerators accrue to HUD. Savings were demonstrated by a metering project and are the subject of the analysis reported here. The New York Power Authority (NYPA) identified the refrigerator with the lowest life-cycle cost, including energy consumption over its expected lifetime, through a request for proposals (RFP) issued to manufacturers for a bulk purchase of 20,000 units in 1997. The procurement was won by Maytag with a 15-ft{sup 3} top-freezer automatic-defrost refrigerator rated at 437 kilowatt-hours/year (kWh/yr). NYCHA then contracted with NYPA to purchase, finance, and install the new refrigerators, and demanufacture and recycle materials from the replaced units. The US Department of Energy (DOE) helped develop and plan the project through the ENERGY STAR{reg_sign} Partnerships program conducted by its Pacific Northwest National Laboratory (PNNL). PNNL designed the metering protocol and occupant survey used in 1997, supplied and calibrated the metering equipment, and managed and analyzed the data collected by NYPA. The objective of the 1997 metering study was to achieve a general understanding of savings as a function of refrigerator label ratings, occupant effects, indoor and compartment temperatures, and characteristics (such as size, defrost features, and vintage). The data collected in 1997 was used to construct models of refrigerator energy consumption as a function of key refrigerator and occupant characteristics.

Pratt, R.G.; Miller, J.D.

1998-09-01T23:59:59.000Z

323

Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties  

SciTech Connect

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

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

2011-06-10T23:59:59.000Z

324

Modeling without categorical variables : a mixed-integer nonlinear program for the optimization of thermal insulation systems.  

SciTech Connect

Optimal design applications are often modeled by using categorical variables to express discrete design decisions, such as material types. A disadvantage of using categorical variables is the lack of continuous relaxations, which precludes the use of modern integer programming techniques. We show how to express categorical variables with standard integer modeling techniques, and we illustrate this approach on a load-bearing thermal insulation system. The system consists of a number of insulators of different materials and intercepts that minimize the heat flow from a hot surface to a cold surface. Our new model allows us to employ black-box modeling languages and solvers and illustrates the interplay between integer and nonlinear modeling techniques. We present numerical experience that illustrates the advantage of the standard integer model.

Abhishek, K.; Leyffer, S.; Linderoth, J. T.; Mathematics and Computer Science; Lehigh Univ.

2010-06-01T23:59:59.000Z

325

Refrigerator: Refrigerators and freezers are not typically constructed to assure that there is no  

E-Print Network (OSTI)

and unstable chemicals only be stored in a lab-safe refrigeration unit that meets National Fire Protection Association 45 ­ Standard on Fire Protection for Laboratories Using Chemicals. #12;Hearing conservation protection which will be furnished by the Institute. Samples of various types of ear muffs, ear caps, and ear

Cohen, Robert E.

326

Experimental investigation of an advanced adsorption refrigeration cycle  

SciTech Connect

Experimental measurements are made for a silica gel-water advanced absorption refrigeration chiller (1.2-kW [4,095-Btu/h] cooling capacity) to evaluate its performance under different temperature and adsorption/desorption cycle time conditions. This paper describes the operating principle of the chiller, outlines the experimental hardware, and discusses results obtained by varying the cooling and hot water inlet temperatures and adsorption/desorption cycle times, as well as their agreement with the simulated results given by a lumped parameter model. The chiller performance is analyzed in terms of cooling capacity and coefficient of performance (COP). Excellent qualitative agreement was obtained between the experimental data and simulated results. The results showed the advanced three-stage cycle to be particularly well suited for operation with low-grade-temperature waste heat as the driving source, since it worked with small regenerating temperature lifts (heat source-heat sink temperature) of 10 to 30 K.

Saha, B.B.; Kashiwagi, Takao [Tokyo Univ. of Agriculture and Technology (Japan). Mechanical Systems Engineering Dept.

1997-12-31T23:59:59.000Z

327

HgCdTe superlattices for solid-state cryogenic refrigeration  

E-Print Network (OSTI)

for solid-state cryogenic refrigeration Daryoosh Vashaee a?merit ?ZT max ? 3? at cryogenic temperatures. Calculationstemperature, 1–6 for cryogenic refrigeration the situation

Vashaee, D; Shakouri, A

2006-01-01T23:59:59.000Z

328

U.S. Residential Miscellaneous Refrigeration Products: Results from Amazon Mechanical Turk Surveys  

E-Print Network (OSTI)

refrigerator operate with propane as well as electricity?refrigerator operate with propane as well as electricity? [freezer operate with propane as well as electricity? [

Greenblatt, Jeffery B.

2014-01-01T23:59:59.000Z

329

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd{sub 0.54}Er{sub 0.46})AlNi alloys having a relatively constant {Delta}Tmc over a wide temperature range. 16 figs.

Gschneidner, K.A. Jr.; Takeya, Hiroyuki

1995-10-31T23:59:59.000Z

330

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

331

Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants  

DOE Patents (OSTI)

A magnetic refrigerant for a magnetic refrigerator using the Ericsson thermodynamic cycle comprises DyAlNi and (Gd.sub.0.54 Er.sub.0.46)AlNi alloys having a relatively constant .DELTA.Tmc over a wide temperature range.

Gschneidner, Jr., Karl A. (Ames, IA); Takeya, Hiroyuki (Ibaraki, JP)

1995-10-31T23:59:59.000Z

332

Control of Refrigeration Systems for Trade-off between Energy  

E-Print Network (OSTI)

Control of Refrigeration Systems for Trade-off between Energy Consumption and Food Quality Loss Ph and Technology (DMST) under Grant: 2002-603/4001-93. CMBC consists of seven industrial companies, three academic of the three academic partners in the center. The refrigeration research activities within CMBC were initiated

Skogestad, Sigurd

333

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

334

Investigation of ammonia equipment configurations for supermarket refrigeration applications (for microcomputers). Software  

SciTech Connect

This product gives results of a project to quantify the advantages and disadvantages of using ammonia with a secondary brine refrigerant compared to R-22 in supermarket refrigeration applications. Project objectives were achieved by numerical experiments using simulations. Mechanistic models of refrigeration system components were used, based on fundamental principles, accepted heat transfer/pressure drop correlations, and available manufacturers` data. Available thermodynamic and transport property data correlations for ammonia and R-22 were used in the models. The parameters of these models were varied to determine their effect on system performance and locate optimum values. A modular approach was used in which each component was separately modeled, allowing simple changes in system configurations. The combined component models resulted in a large set of coupled nonlinear algebraic equations for the quasi-steady systems that did not involve brine storage. The system involved differential and algebraic equations. These equations were solved using the general-purpose simulation programs EES and TRNSYS. EES is a robust nonlinear equation-solving program with built-in thermophysical property data. TRNSYS is a sequential modular simulation program that uses schemes to solve coupled algebraic and differential equations.

NONE

1995-02-01T23:59:59.000Z

335

This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed in MATLAB. The model uses cycle inputs such as the fluid mass flow and  

E-Print Network (OSTI)

in MATLAB. The model uses cycle inputs such as the fluid mass flow and magnetic field profiles, fluid

Wisconsin at Madison, University of

336

North Star Refrigerator: Proposed Penalty (2013-CE-5355) | Department of  

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

North Star Refrigerator: Proposed Penalty (2013-CE-5355) North Star Refrigerator: Proposed Penalty (2013-CE-5355) North Star Refrigerator: Proposed Penalty (2013-CE-5355) March 26, 2013 DOE alleged in a Notice of Proposed Civil Penalty that North Star Refrigerator Co., Inc. failed to certify a variety of walk-in cooler or freezer components as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. North Star Refrigerator: Proposed Penalty (2013-CE-5355) More Documents & Publications

337

Duracold Refrigeration Manufacturing: Proposed Penalty (2013-CE-5342) |  

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

Duracold Refrigeration Manufacturing: Proposed Penalty Duracold Refrigeration Manufacturing: Proposed Penalty (2013-CE-5342) Duracold Refrigeration Manufacturing: Proposed Penalty (2013-CE-5342) February 21, 2013 DOE alleged in a Notice of Proposed Civil Penalty that Duracold Refrigeration Manufacturing Company, LLC failed to certify a variety of walk-in cooler or freezer components as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. Duracold Refrigeration Manufacturing: Proposed Penalty (2013-CE-5342)

338

DOE Proposes Higher Efficiency Standards for Refrigerators | Department of  

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

DOE Proposes Higher Efficiency Standards for Refrigerators DOE Proposes Higher Efficiency Standards for Refrigerators DOE Proposes Higher Efficiency Standards for Refrigerators September 28, 2010 - 12:00am Addthis WASHINGTON, DC - U.S. Energy Secretary Steven Chu today announced the release of a new proposed energy efficiency standard for residential refrigerators, refrigerator-freezers, and freezers. The standard, as proposed, could save consumers as much as $18.6 billion over thirty years. The Obama Administration has made efficiency standards a major priority as a way to save energy and money for American families and businesses. Since January 2009, the Department of Energy has finalized new efficiency standards for more than twenty household and commercial products, which will cumulatively save consumers between $250 billion and

339

North Star Refrigerator: Proposed Penalty (2013-CE-5355) | Department of  

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

North Star Refrigerator: Proposed Penalty (2013-CE-5355) North Star Refrigerator: Proposed Penalty (2013-CE-5355) North Star Refrigerator: Proposed Penalty (2013-CE-5355) March 26, 2013 DOE alleged in a Notice of Proposed Civil Penalty that North Star Refrigerator Co., Inc. failed to certify a variety of walk-in cooler or freezer components as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. North Star Refrigerator: Proposed Penalty (2013-CE-5355) More Documents & Publications

340

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

E-Print Network (OSTI)

Date | 1Refrigeration and Air Conditioning EMA Education and Training #12;Date | 2Refrigeration operating pressure (MOP) 5. De-humidifying (Te control) 6. Defrost funtions 7. Loss of charge detection (LOC control) 6. Defrost funtions 7. Loss of charge detection (LOC) 8. Bleed function 9. Sensor placement tips

Oak Ridge National Laboratory

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Three-dimensional finite-element model for simulating water flow in variability saturated porous media  

SciTech Connect

A three-dimensional finite-element model for simulating water flow in variably saturated porous media is presented. The model formulation is general and capable of accommodating complex boundary conditions associated with seepage faces and infiltration or evaporation on the soil surface. Included in this formulation is an improved Picard algorithm designed to cope with severely nonlinear soil moisture relations. The algorithm is formulated for both rectangular and triangular prism elements. The element matrices are evaluated using an influence coefficient technique that avoids costly numerical integration. Spatial discretization of a three-dimensional regions is performed using a vertical slicing approach designed to accommodate complex geometry with irregular boundaries, layering, and/or lateral discontinuities. Matrix solution is achieved using a slice successive overrelaxation scheme that permits a fairly large number of nodal unknowns (on the order of several thousand) to be handled efficiently on small minicomputers. Six examples are presented to verify and demonstrate the utility of the proposed finite-element model. The first four examples concern one- and two-dimensional flow problems used as sample problems to benchmark the code. The remaining examples concern three-dimensions problems. These problems are used to illustrate the performance of the proposed algorithm in three-dimensional situations involving seepage faces and anisotropic soil media.

Huyakorn, P.S.; Springer, E.P.; Guvanasen, V.; Wadsworth, T.D.

1986-12-01T23:59:59.000Z

342

Experience in Measuring Backbone Traffic Variability: Models, Metrics, Measurements and Meaning  

E-Print Network (OSTI)

was specifically motivated by the question: to what extent does traffic variability justify the M. Roughen, A

Fisher, Kathleen

343

Operation and maintenance of Fermilab`s satellite refrigerator expansion engines  

SciTech Connect

Fermilab`s superconducting Tevatron accelerator is cooled to liquid helium temperatures by 24 satellite refrigerators, each of which uses for normal operations a reciprocating `wet` expansion engine. These expanders are basically Process System (formerly Koch) Model 1400 expanders installed in standalone cryostats designed by Fermilab. This paper will summarize recent experience with operations and maintenance of these expansion engines. Some of the statistics presented will include total engine hours, mean time between major and minor maintenance, and frequent causes of major maintenance.

Soyars, W.M.

1996-09-01T23:59:59.000Z

344

Refrigeration Recovery for Experiment Hall High Target Loads  

SciTech Connect

The Qweak experiment at Jefferson Lab (JLab) is a 3000 W hydrogen target scheduled for the summer of 2010 and running for two years until the planned shut-down for 12GeV. The End Station Refrigerator (ESR) supports the three experiment halls, two of which may normally have a hydrogen target. The refrigerator for the ESR is a CTI/Helix 1500 W 4.5-K refrigerator nominally capable of supporting a 1250 W target load at 12 bar and 15-K (plus 1100 W of 4.5-K refrigeration). As such, this refrigerator is not capable of supporting the Qweak experiment target load in its present condition. Additionally, since the installation of an ambient air vaporizer for a single use, two week run duration of a high target load in the summer of 2003 there has been a consistent usage of the Central Helium Liquefier’s (CHL’s) 3 bar 4.5-K helium, supplied via an existing transfer-line to the ESR, for other high target loads. By the fall of 2004, it was apparent that this continued use of CHL’s supercritical helium was routinely being sought by the hall experimenters. As such, a method of refrigeration recovery was proposed to reduce the support required of CHL for these high target loads, including the anticipated Qweak experiment, while utilizing the recovered CHL refrigeration from the target to increase ESR’s 12 bar 15-K capacity.

Peter Knudsen, Venkatarao Ganni, Errol Yuksek, Jonathan Creel

2010-04-01T23:59:59.000Z

345

Effect of parasitic refrigeration on the efficiency of magnetic liquefiers  

SciTech Connect

Our studies have shown that magnetic refrigerators have the potential to liquefy cryogens very efficiently. High efficiency is especially important for liquid hydrogen and natural gas applications where the liquefaction costs are a significant fraction of the total liquid cost. One of the characteristics of magnetic refrigerators is the requirement for a high-field superconducting magnet. Providing a 4.2-K bath for this magnet will require a small amount of parasitic refrigeration at 4.2 K even though the rest of the liquefier may be at 110 K (liquid natural gas) or higher. For several different refrigeration power levels at 4.2 K, we have calculated the efficiency of the magnetic liquefier as a function of power, temperature and the 4.2-K refrigerator efficiency. The results show that if the ratio of the thermal load at 4.2 K to the main refrigerator power is 0.001 or less, the effect on the efficiency of the liquefier is negligible at all temperatures below room temperature provided the 4.2-K refrigerator efficiency is high.

Barclay, J.A.; Stewart, W.F.

1982-01-01T23:59:59.000Z

346

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

347

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

348

Product Refrigerator Freezer Fresh, in shell 4 to 5 weeks Don't freeze  

E-Print Network (OSTI)

Product Refrigerator Freezer Eggs Fresh, in shell 4 to 5 weeks Don't freeze Raw yolks, whites 2 recommended storage times are for quality only. Refrigerator & Freezer Storage Chart Product Refrigerator, opened 3 days Don't freeze unopened 10 days 1 year Mayonnaise, commercial Refrigerate after opening 2

Burke, Peter

349

Integrability study on a generalized (2+1)-dimensional variable-coefficient Gardner model with symbolic computation  

SciTech Connect

Gardner model describes certain nonlinear elastic structures, ion-acoustic waves in plasmas, and shear flows in ocean and atmosphere. In this paper, by virtue of the computerized symbolic computation, the integrability of a generalized (2+1)-dimensional variable-coefficient Gardner model is investigated. Painleve integrability conditions are derived among the coefficient functions, which reduce all the coefficient functions to be proportional only to {gamma}(t), the coefficient of the cubic nonlinear term u{sup 2}u{sub x}. Then, an independent transformation of the variable t transforms the reduced {gamma}(t)-dependent equation into a constant-coefficient integrable one. Painleve test shows that this is the only case when our original generalized (2+1)-dimensional variable-coefficient Gardner model is integrable.

Lue Xing; Zhang Haiqiang; Xu Tao; Li He [School of Science, Beijing University of Posts and Telecommunications, P.O. Box 122, Beijing 100876 (China); Tian Bo [School of Science, Beijing University of Posts and Telecommunications, P.O. Box 122, Beijing 100876 (China); State Key Laboratory of Software Development Environment, Beijing University of Aeronautics and Astronautics, Beijing 100191 (China); Key Laboratory of Information Photonics and Optical Communications (BUPT), Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 128, Beijing 100876 (China)

2010-12-15T23:59:59.000Z

350

New Regenerative Cycle for Vapor Compression Refrigeration  

Office of Scientific and Technical Information (OSTI)

SCIENTIFIC REPORT SCIENTIFIC REPORT Title Page Project Title: New Regenerative Cycle for Vapor Compression Refrigeration DOE Award Number: DE-FG36-04GO14327 Document Title: Final Scientific Report Period Covered by Report: September 30, 2004 to September 30, 2005 Name and Address of Recipient Organization: Magnetic Development, Inc., 68 Winterhill Road, Madison, CT 06443, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Contact Information: Mark J. Bergander, Ph.D., P.E., Principal Investigator, phone: 203-214-7247, fax: 203-421-7948, e-mail: mjb1000@aol.com Project Objective (as stated in the proposal): The main objective of this project is to confirm on a well-instrumented prototype the theoretically derived claims of higher efficiency and coefficient

351

Isothermally heatsunk diffusion cloud chamber refrigerator  

SciTech Connect

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

352

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

353

EPA's research projects relating to the dual-circuit and Lorenz refrigerator/freezers  

SciTech Connect

At a meeting in February 1989, EPA presented to several research universities, national laboratories, and refrigerator/freezer (RF) manufacturers the Agency's desire to replace CFC-12 as a refrigerant in the RF vapor compression cycle and increase RF energy efficiency. EPA recognized that, while eliminating CFCs, energy benefits could be gained by further product development (e.g., improving compressor efficiency or heat transfer surface areas). The largest cycle energy gains, however, were expected to be a result of completely different vapor compression configuration. Two new vapor compression configurations were suggested by the participants - the Lorenz design and the dual-circuit design. A decision was made to construct and test modified RFs as proof that the advanced refrigerants and cycles could achieve energy gains. An RF computer model has been updated and expanded which can model both the Lorenz and dual-circuit RF. Modified RF testing and component testing in test stands is being performed to determine the increased energy performance of these configurations.

Bare, J.C. (Environmental Protection Agency, Research Triangle Park, NC (United States))

1992-01-01T23:59:59.000Z

354

2014-10-06 DOE Certification, Compliance, and Enforcement Overview for Refrigerators, Refrigerator-Freezers, Freezers, Dehumidifiers, Room Air Conditioners, Clothes Washers, Clothes Dryers, and Dishwashers  

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

This presentation provides an overview of DOE Certification, Compliance, and Enforcement for Refrigerators, Refrigerator-Freezers, Freezers, Dehumidifiers, Room Air Conditioners, Clothes Washers, Clothes Dryers, and Dishwashers. It was presented via webinar on October 6, 2014.

355

Product Standards for Refrigerators (Japan) | Open Energy Information  

Open Energy Info (EERE)

Product Standards for Refrigerators (Japan) Product Standards for Refrigerators (Japan) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Product Standards for Refrigerators (Japan) Focus Area: Appliances & Equipment Topics: Policy Impacts Website: www.eccj.or.jp/top_runner/pdf/tr_re-freez_Jul.2006.pdf Equivalent URI: cleanenergysolutions.org/content/product-standards-refrigerators-japan Language: English Policies: "Deployment Programs,Regulations" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Industry Codes & Standards Regulations: Appliance & Equipment Standards and Required Labeling This Energy Conservation Center Japan (ECCJ) document was created as a guide in response to its newly established set of standards and labelling

356

Property:Building/SPElectrtyUsePercRefrigeration | Open Energy Information  

Open Energy Info (EERE)

SPElectrtyUsePercRefrigeration SPElectrtyUsePercRefrigeration Jump to: navigation, search This is a property of type String. Refrigeration Pages using the property "Building/SPElectrtyUsePercRefrigeration" Showing 25 pages using this property. (previous 25) (next 25) S Sweden Building 05K0001 + 0.0 + Sweden Building 05K0002 + 0.0 + Sweden Building 05K0003 + 0.0 + Sweden Building 05K0004 + 0.0 + Sweden Building 05K0005 + 0.0 + Sweden Building 05K0006 + 4.24846345193 + Sweden Building 05K0007 + 0.0 + Sweden Building 05K0008 + 0.0 + Sweden Building 05K0009 + 0.0 + Sweden Building 05K0010 + 24.6944086225 + Sweden Building 05K0011 + 0.0 + Sweden Building 05K0012 + 0.0 + Sweden Building 05K0013 + 1.29913989581 + Sweden Building 05K0014 + 7.46645043826 + Sweden Building 05K0015 + 0.0 +

357

DOE Reaches Agreement with LG Electronics, USA, On Refrigerator Energy  

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

Reaches Agreement with LG Electronics, USA, On Refrigerator Reaches Agreement with LG Electronics, USA, On Refrigerator Energy Matter DOE Reaches Agreement with LG Electronics, USA, On Refrigerator Energy Matter November 14, 2008 - 4:47pm Addthis ENERGY STAR® Program Continues to Help American Consumers Make Energy Efficient Choices WASHINGTON - The U.S. Department of Energy (DOE) today announced an agreement with LG Electronics, USA, Inc. (LG), resolving concerns related to energy usage measurements reported on LG French Door refrigerators with through-the-door ice and water service. The ENERGY STAR® program helps American consumers make energy efficient choices, saving billions of dollars while protecting the environment by using identified energy efficient products and practices. "DOE believes that the actions LG plans to take will benefit consumers and

358

Application of Cryocoolers to a Vintage Dilution Refrigerator  

SciTech Connect

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

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

2011-06-06T23:59:59.000Z

359

Energy Department Announces More Stringent Criteria for ENERGY STAR® Refrigerators  

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

WASHINGTON, DC - The U.S. Department of Energy (DOE) today announced increased energy efficient criteria for refrigerators carrying the ENERGY STAR® label.  In order to qualify, full-size...

360

High-Efficiency, Low-Emission Refrigeration System | Department...  

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

of the compressor rack and system diagram for the CO2 refrigeration system.
Credit: Oak Ridge National Lab Image of the compressor rack and system diagram for the CO2...

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Speed Control in Industrial Refrigeration: Theory, Application & Case Studies  

E-Print Network (OSTI)

It is often standard practice in the field of industrial refrigeration to design and operate systems with little regard toward part-load performance. This approach is understandable, whether viewed from the standpoint of the design engineer, plant...

Wilcox, M. H.

362

Applications Tests of Energy Efficient, Environmentally Friendly Refrigerants  

E-Print Network (OSTI)

This paper describes performance demonstrations of two members of the Ikon® family of safe, environmentally friendly, high performance substitute refrigerants for replacement of R-12 and R-134a in manufacturing and facilities operations. Preliminary...

Nimitz, J.; Glass, S.; McCullough, E.; Dhooge, P.

363

Designing Augmented Refrigerator Magnets Rachel Eardley, Laurel Swan  

E-Print Network (OSTI)

Designing Augmented Refrigerator Magnets Rachel Eardley, Laurel Swan , Abi Sellen Alex S. Taylor philosophy. As such, they are designed to operate as a modular based system so that their various functions

Hunt, Galen

364

6 Energy Saving Tips for Commercial Refrigerators and Freezers  

Office of Energy Efficiency and Renewable Energy (EERE)

To help businesses save energy and money, the Energy Department today announced new standards aimed at making commercial refrigerators and freezers. Here are just a few more tips to increase the energy efficiency of these appliances.

365

Combined Cold Compressor/Ejector Helium Refrigerator Cycle  

Science Journals Connector (OSTI)

In recent years there has been increasing interest in raising refrigeration efficiency and capacity in cycles which produce cooling below 4.2 K. It is, of course, desirable to be able to produce the required s...

A. P. Schlafke; D. P. Brown; K. C. Wu

1984-01-01T23:59:59.000Z

366

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 1.65–1.75 kg, 6.0 m2, 70 m and 9 mm, 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

367

Automatic determination about precision parameter value based on inclusion degree with variable precision rough set model  

Science Journals Connector (OSTI)

Abstract The rough set theory provides a powerful approach for attributes reduction and data analysis. The variable precision rough set (VPRS) model, an extension of the original rough set approach, tolerates misclassifications of the training data to some degree, which promotes the applications of rough set theory in inconsistent information systems. However, in most existing algorithms of feature reduction based on VPRS, the precision parameter (?) is introduced as prior knowledge, which restricts their applications because it is not clear how to set the ? value. By studying ?-consistency in the measurement of a decision table and the threshold value of the ?-consistent decision table, this paper presents an algorithm for automatic determination of the precision parameter value from a decision table based on VPRS. At the same time, the precision parameter value from our proposed method is compared with the thresholds from the decision-theoretic rough set (DTRS). The influences of the precision parameter are also discussed on attribute reduction, which shows the necessity of the estimated precision parameter from a decision table. The simulation results including VPRS and other classification methods in real data further indicate that different precision parameter values make a great difference on rules and setting a precise parameter near the threshold value of the ?-consistent decision table can precisely reflect the decision distribution of the decision table.

Yusheng Cheng; Wenfa Zhan; Xindong Wu; Yuzhou Zhang

2015-01-01T23:59:59.000Z

368

Refrigerator design for the ambulatory and wheelchair-using elderly  

E-Print Network (OSTI)

REFRIGERATOR DESIGN FOR THE AMBULATORY ANO WHEELCHAIR-USING ELDERLY A Thesis by MARY SUE MILLS Submitted to the Graduate College of Texas A S M University in partial fulfillment of the requirements f or the degree of MASTER OF SCIENCE May... 198S Major Subject: Industrial Engineering REFRIGERATOR DESIGN FOR THE AMBULATORY AND WHEELCHAIR-USING ELDERLY A Thesis by MARY SUE MILLS Approved as to style and content by: )7 Rodg Koppa (Chair of Committee) rome . Co leton ( ember...

Mills, Mary Sue

2012-06-07T23:59:59.000Z

369

ARI delegation to Japan on Alternative Refrigerants. [Foreign Trip Report  

SciTech Connect

Researchers from ARI member companies spoke at the International Conference on Alternative Refrigerants in Tokyo and visited several Japanese organizations for the purpose of exchanging information on alternative refrigerants. The specific purpose of the meetings was to review the methods being utilized to screen alternatives to CFCs and HCFCs: materials compatibility screening methods, lubricant testing techniques, as well as flammability studies. A list of papers presented at the conference is included.

Not Available

1993-02-01T23:59:59.000Z

370

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve Timing  

E-Print Network (OSTI)

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve engine efficiency. Fuel-flexible engines permit the increased use of ethanol-gasoline blends. Ethanol points across the engine operating range for four blends of gasoline and ethanol. I. INTRODUCTION Fuel

371

A review of lubrication and preformance issues in refrigeration systems using an HFC (R-134a) refrigerant  

SciTech Connect

It has been considered critical for refrigerant and compressor lubricant to be miscible with each other over part of the range of operating conditions of refrigerant systems. Adequate miscibility, many believe, provides oil return to the compressor. Presently, synthetic polyol esters have been selected for use with HFC refrigerants, such as R-134a, which are considered appropriate alternatives to CFCs. The authors will review the mechanical issues in miscible vs non-miscible naphthenic hydrocarbon oil-based lubricants. Extensive lab, test stand and cabinet testing has been conducted and data will be presented which show responsible and predictable performance based on the chemical and physical properties of the lubricant and refrigerant. Many non-miscible systems show satisfactory performance with the proper selection of lubricant, additives and mechanical configuration. 3 refs., 3 figs., 5 tabs.

Reyes-Gavilan, J.; Eckard, A.; Flak, T.; Tritak, T. [Witco Corporation, Oakland, NJ (United States)

1996-04-01T23:59:59.000Z

372

Fridge of the future: Designing a one-kilowatt-hour/day domestic refrigerator-freezer  

SciTech Connect

An industry/government Cooperative Research and Development Agreement (CRADA) was established to evaluate and test design concepts for a domestic refrigerator-freezer unit that represents approximately 60% of the US market. The goal of the CRADA was to demonstrate advanced technologies which reduce, by 50 percent, the 1993 NAECA standard energy consumption for a 20 ft{sup 3} (570 I) top-mount, automatic-defrost, refrigerator-freezer. For a unit this size, the goal translated to an energy consumption of 1.003 kWh/d. The general objective of the research was to facilitate the introduction of cost-efficient technologies by demonstrating design changes that can be effectively incorporated into new products. A 1996 model refrigerator-freezer was selected as the baseline unit for testing. Since the unit was required to meet the 1993 NAECA standards, the energy consumption was quite low (1.676 kWh/d), thus making further reductions in energy consumption very challenging. Among the energy saving features incorporated into the original design of the baseline unit were a low-wattage evaporator fan, increased insulation thicknesses, and liquid line flange heaters.

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

1998-03-01T23:59:59.000Z

373

On the ""early-time"" evolution of variables relevant to turbulence models for Rayleigh-Taylor instability  

SciTech Connect

We present our progress toward setting initial conditions in variable density turbulence models. In particular, we concentrate our efforts on the BHR turbulence model for turbulent Rayleigh-Taylor instability. Our approach is to predict profiles of relevant parameters before the fully turbulent regime and use them as initial conditions for the turbulence model. We use an idealized model of the mixing between two interpenetrating fluids to define the initial profiles for the turbulence model parameters. Velocities and volume fractions used in the idealized mixing model are obtained respectively from a set of ordinary differential equations modeling the growth of the Rayleigh-Taylor instability and from an idealization of the density profile in the mixing layer. A comparison between predicted initial profiles for the turbulence model parameters and initial profiles of the parameters obtained from low Atwood number three dimensional simulations show reasonable agreement.

Rollin, Bertrand [Los Alamos National Laboratory; Andrews, Malcolm J [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

374

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

375

Demand Response Opportunities in Industrial Refrigerated Warehouses in  

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

Response Opportunities in Industrial Refrigerated Warehouses in Response Opportunities in Industrial Refrigerated Warehouses in California Title Demand Response Opportunities in Industrial Refrigerated Warehouses in California Publication Type Conference Paper LBNL Report Number LBNL-4837E Year of Publication 2011 Authors Goli, Sasank, Aimee T. McKane, and Daniel Olsen Conference Name 2011 ACEEE Summer Study on Energy Efficiency in Industry Date Published 08/2011 Conference Location Niagara Falls, NY Keywords market sectors, openadr, refrigerated warehouses Abstract Industrial refrigerated warehouses that implemented energy efficiency measures and have centralized control systems can be excellent candidates for Automated Demand Response (Auto-DR) due to equipment synergies, and receptivity of facility managers to strategies that control energy costs without disrupting facility operations. Auto-DR utilizes OpenADR protocol for continuous and open communication signals over internet, allowing facilities to automate their Demand Response (DR). Refrigerated warehouses were selected for research because: They have significant power demand especially during utility peak periods; most processes are not sensitive to short-term (2-4 hours) lower power and DR activities are often not disruptive to facility operations; the number of processes is limited and well understood; and past experience with some DR strategies successful in commercial buildings may apply to refrigerated warehouses. This paper presents an overview of the potential for load sheds and shifts from baseline electricity use in response to DR events, along with physical configurations and operating characteristics of refrigerated warehouses. Analysis of data from two case studies and nine facilities in Pacific Gas and Electric territory, confirmed the DR abilities inherent to refrigerated warehouses but showed significant variation across facilities. Further, while load from California's refrigerated warehouses in 2008 was 360 MW with estimated DR potential of 45-90 MW, actual achieved was much less due to low participation. Efforts to overcome barriers to increased participation may include, improved marketing and recruitment of potential DR sites, better alignment and emphasis on financial benefits of participation, and use of Auto-DR to increase consistency of participation.

376

Technology data characterizing refrigeration in commercial buildings: Application to end-use forecasting with COMMEND 4.0  

SciTech Connect

In the United States, energy consumption is increasing most rapidly in the commercial sector. Consequently, the commercial sector is becoming an increasingly important target for state and federal energy policies and also for utility-sponsored demand side management (DSM) programs. The rapid growth in commercial-sector energy consumption also makes it important for analysts working on energy policy and DSM issues to have access to energy end-use forecasting models that include more detailed representations of energy-using technologies in the commercial sector. These new forecasting models disaggregate energy consumption not only by fuel type, end use, and building type, but also by specific technology. The disaggregation of the refrigeration end use in terms of specific technologies, however, is complicated by several factors. First, the number of configurations of refrigeration cases and systems is quite large. Also, energy use is a complex function of the refrigeration-case properties and the refrigeration-system properties. The Electric Power Research Institute`s (EPRI`s) Commercial End-Use Planning System (COMMEND 4.0) and the associated data development presented in this report attempt to address the above complications and create a consistent forecasting framework. Expanding end-use forecasting models so that they address individual technology options requires characterization of the present floorstock in terms of service requirements, energy technologies used, and cost-efficiency attributes of the energy technologies that consumers may choose for new buildings and retrofits. This report describes the process by which we collected refrigeration technology data. The data were generated for COMMEND 4.0 but are also generally applicable to other end-use forecasting frameworks for the commercial sector.

Sezgen, O.; Koomey, J.G.

1995-12-01T23:59:59.000Z

377

Direct comparison of Neural Network, Fuzzy Logic and Model Prediction Variable Structure vortex flow controllers  

E-Print Network (OSTI)

Predictive Variable Structure and Fuzzy Logic based controllers for the same benchmark problem. Evaluation criteria consist of closed-loop system performance, activity level of the VFC nozzles, ease of controller synthesis, time required to synthesize...

Joshi, Praveen Sudhakar

2012-06-07T23:59:59.000Z

378

Mechanisms of Decadal Arctic Climate Variability in the Community Climate System Model, Version 2 (CCSM2)  

Science Journals Connector (OSTI)

Several mechanisms have been proposed to explain natural climate variability in the Arctic. These include processes related to the influence of the North Atlantic Oscillation/Arctic Oscillation (NAO/AO), anticyclonic/cyclonic regimes, changes in ...

Hugues Goosse; Marika M. Holland

2005-09-01T23:59:59.000Z

379

L&E: Refrigerated Display Case | The Better Buildings Alliance  

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

Lighting & Electrical » Adopt the Lighting & Electrical » Adopt the refrigerated display case lighting performance specification and start saving on your case lighting costs Activities Technology Solutions Teams Lighting & Electrical Space Conditioning Plug & Process Loads Food Service Refrigeration Laboratories Energy Management & Information Systems Public Sector Teams Market Solutions Teams Adopt the refrigerated display case lighting performance specification and start saving on your case lighting costs The LED Refrigerated Display Case Lighting Specification delivers nearly 50% energy savings compared to typical display case lighting. If all retail refrigerated display cases switched today to LED systems, over 2.1 TWh of electricity could be saved annually. LED Refrigerated Display Case Lighting Specification

380

Combination cooler and freezer for refrigerating containers and food in outer space  

SciTech Connect

A refrigeration apparatus for cooling containers and food in the microgravity conditions of outer space is described comprising: (a) a housing defining a refrigeration compartment for supporting the containers in a container storage area and food in a refrigerated food storage area, and freezer compartment; (b) cold plate means within the refrigeration compartment for cooling the containers and food by conduction; (c) thermoelectric refrigeration means for maintaining the cold plates at temperatures which cool the contents of the refrigeration compartment, and the freezer compartment.

Rudick, A.G.

1988-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

The Community Earth System Model (CESM) Large Ensemble Project: A Community Resource for Studying Climate Change in the Presence of Internal Climate Variability  

Science Journals Connector (OSTI)

While internal climate variability is known to affect climate projections, its influence is often underappreciated and confused with model error. Why? In general, modeling centers contribute a small number of realizations to international climate ...

J. E. Kay; C. Deser; A. Phillips; A. Mai; C. Hannay; G. Strand; J. M. Arblaster; S. C. Bates; G. Danabasoglu; J. Edwards; M. Holland; P. Kushner; J.-F. Lamarque; D. Lawrence; K. Lindsay; A. Middleton; E. Munoz; R. Neale; K. Oleson; L. Polvani; M. Vertenstein

382

The Climatology and Interannual Variability of East Asian Summer Monsoon in CMIP5 Coupled Models: Does Air–Sea Coupling Improve the Simulations?  

Science Journals Connector (OSTI)

The climatology and interannual variability of the East Asian summer monsoon (EASM) simulated by 34 coupled general circulation models (CGCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are evaluated. To estimate the role of ...

Fengfei Song; Tianjun Zhou

2014-12-01T23:59:59.000Z

383

1. For a refrigerator, you are given that 1 ,0 20 400 t p t = - ? ? . The ...  

E-Print Network (OSTI)

1. For a refrigerator, you are given that. 2. 0. 1. ,0. 20. 400 t t p t. = -. ? ? . The Purdue Actuarial club owns two refrigerators. One is brand new and one was ...

Owner

2011-04-28T23:59:59.000Z

384

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...

385

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

386

Design of a Large 2.0 K Refrigerator for CEBAF  

Science Journals Connector (OSTI)

The CEBAF refrigerator is designed to produce 4620 watts of ... Several design features are described, including a modular concept for the 2 K and 4.5 K refrigerator sections and the use of multistage centrifugal...

H. Parish; G. Gistau; C. Hood; K. Kreinbrink; W. Appleton

1991-01-01T23:59:59.000Z

387

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

388

Design and Optimization of a Pure Refrigerant Cycle for Natural Gas Liquefaction with Subcooling  

Science Journals Connector (OSTI)

Design and Optimization of a Pure Refrigerant Cycle for Natural Gas Liquefaction with Subcooling ... The world’s first commercial LNG plant uses the cascade process, which employs three different pure refrigerants: propane, ethane (or ethylene), and methane. ...

Inkyu Lee; Kyungjae Tak; Hweeung Kwon; Junghwan Kim; Daeho Ko; Il Moon

2014-05-14T23:59:59.000Z

389

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

SciTech Connect

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

390

A coupled model study of the remote influence of enso on tropical Atlantic sst variability  

E-Print Network (OSTI)

stage one in this region. In general, the horizontal advection of heat plays a secondary role in the SST response to the remote influence of ENSO, except in the regions where the North Equatorial Countercurrent (NECC) dominates and the SST variability...

Fang, Yue

2006-08-16T23:59:59.000Z

391

Quantum spins mimic refrigerator magnets - Argonne National Laboratories,  

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

Highlights > Quantum spins mimic refrigerator Highlights > Quantum spins mimic refrigerator magnets Quantum spins mimic refrigerator magnets By Joseph Bernstein * October 11, 2012 The behavior of magnetic moments in metal oxides such as layered iridium is dominated by strong spin-orbit coupling effects. In layered compounds such as Sr3Ir2O7 (shown on the left), the direction of these moments (blue arrows) is controlled at the quantum level by dipolar interactions that are akin to those of classical bar magnets. Another outcome is an unprecedented 'magnon gap' (shown at right), which was measured at the Argonne Advanced Photon Source and reveals that these underlying dipolar magnetic interactions are extremely strong. Current electronic devices depend on manipulating charge. Alternative approaches may rely on not only charge but also the spin of electrons.

392

Thailand Sectoral Study on Climate and Refrigeration Technology in  

Open Energy Info (EERE)

Thailand Sectoral Study on Climate and Refrigeration Technology in Thailand Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Jump to: navigation, search Name Thailand-Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Agency/Company /Organization Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Sector Climate Focus Area Renewable Energy, Greenhouse Gas Topics Low emission development planning, -LEDS, -NAMA, Market analysis Website http://www.giz.de/en/ Program Start 2010 Program End 2012 Country Thailand South-Eastern Asia References Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)[1]

393

South Africa Sectoral Study on Climate and Refrigeration Technology in  

Open Energy Info (EERE)

South Africa Sectoral Study on Climate and Refrigeration Technology in South Africa Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Jump to: navigation, search Name South Africa-Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Agency/Company /Organization Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Sector Climate Focus Area Renewable Energy, Greenhouse Gas Topics Low emission development planning, -LEDS, -NAMA, Market analysis Website http://www.giz.de/en/ Program Start 2010 Program End 2012 Country South Africa Southern Africa

394

India Sectoral Study on Climate and Refrigeration Technology in Developing  

Open Energy Info (EERE)

India Sectoral Study on Climate and Refrigeration Technology in Developing India Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Jump to: navigation, search Name India-Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Agency/Company /Organization Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Sector Climate Focus Area Renewable Energy, Greenhouse Gas Topics Low emission development planning, -LEDS, -NAMA, Market analysis Website http://www.giz.de/en/ Program Start 2010 Program End 2012 Country India Southern Asia References Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)[1]

395

Mexico Sectoral Study on Climate and Refrigeration Technology in Developing  

Open Energy Info (EERE)

Mexico Sectoral Study on Climate and Refrigeration Technology in Developing Mexico Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Jump to: navigation, search Name Mexico-Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Agency/Company /Organization Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Sector Climate Focus Area Renewable Energy, Greenhouse Gas Topics Low emission development planning, -LEDS, -NAMA, Market analysis Website http://www.giz.de/en/ Program Start 2010 Program End 2012 Country Mexico Central America References Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)[1]

396

Sectoral Study on Climate and Refrigeration Technology in Developing  

Open Energy Info (EERE)

Study on Climate and Refrigeration Technology in Developing Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Jump to: navigation, search Name Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and Implementing NAMAs Agency/Company /Organization Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH Sector Climate Focus Area Renewable Energy, Greenhouse Gas Topics Low emission development planning, -LEDS, -NAMA, Market analysis Website http://www.giz.de/en/ Program Start 2010 Program End 2012 Country India, Mexico, South Africa, Thailand Southern Asia, Central America, Southern Africa, South-Eastern Asia

397

Intermittent absorption refrigeration system equipped with an economizer  

Science Journals Connector (OSTI)

Abstract Conservation of useful form of energy, i.e. electricity to be used in the production sector rather than consumption sector is becoming a priority in the KSA (Kingdom of Saudi Arabia). One of the consumption sectors which utilize a large amount of electrical energy is the air-conditioning and refrigeration sector. Improving the performance of refrigeration and air-conditioning systems and utilizing solar energy in powering such systems will contribute to significant conservation of electrical energy in the kingdom of Saudi-Arabia. Hence, the objective of the present study is to improve the performance of intermittent solar absorption refrigeration system. To achieve this objective, the design of a conventional intermittent system has been modified by introducing an economizer into the system. The analysis of the modified design system indicated an increase of 20% in the coefficient of performance of the system.

S.A.M. Said; M.A.I. El-Shaarawi; M.U. Siddiqui

2013-01-01T23:59:59.000Z

398

Energy Efficiency Standards for Refrigerators in Brazil: A Methodology for  

Open Energy Info (EERE)

Energy Efficiency Standards for Refrigerators in Brazil: A Methodology for Energy Efficiency Standards for Refrigerators in Brazil: A Methodology for Impact Evaluation Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Energy Efficiency Standards for Refrigerators in Brazil: A Methodology for Impact Evaluation Focus Area: Energy Efficiency Topics: Potentials & Scenarios Website: www.scribd.com/doc/34712276/Energy-efficiency-standards-for-refrigerat Equivalent URI: cleanenergysolutions.org/content/energy-efficiency-standards-refrigera Language: English Policies: Regulations Regulations: "Appliance & Equipment Standards and Required Labeling,Emissions Standards" is not in the list of possible values (Agriculture Efficiency Requirements, Appliance & Equipment Standards and Required Labeling, Audit Requirements, Building Certification, Building Codes, Cost Recovery/Allocation, Emissions Mitigation Scheme, Emissions Standards, Enabling Legislation, Energy Standards, Feebates, Feed-in Tariffs, Fuel Efficiency Standards, Incandescent Phase-Out, Mandates/Targets, Net Metering & Interconnection, Resource Integration Planning, Safety Standards, Upgrade Requirements, Utility/Electricity Service Costs) for this property.

399

Demand Response Opportunities in Industrial Refrigerated Warehouses in California  

SciTech Connect

Industrial refrigerated warehouses that implemented energy efficiency measures and have centralized control systems can be excellent candidates for Automated Demand Response (Auto-DR) due to equipment synergies, and receptivity of facility managers to strategies that control energy costs without disrupting facility operations. Auto-DR utilizes OpenADR protocol for continuous and open communication signals over internet, allowing facilities to automate their Demand Response (DR). Refrigerated warehouses were selected for research because: They have significant power demand especially during utility peak periods; most processes are not sensitive to short-term (2-4 hours) lower power and DR activities are often not disruptive to facility operations; the number of processes is limited and well understood; and past experience with some DR strategies successful in commercial buildings may apply to refrigerated warehouses. This paper presents an overview of the potential for load sheds and shifts from baseline electricity use in response to DR events, along with physical configurations and operating characteristics of refrigerated warehouses. Analysis of data from two case studies and nine facilities in Pacific Gas and Electric territory, confirmed the DR abilities inherent to refrigerated warehouses but showed significant variation across facilities. Further, while load from California's refrigerated warehouses in 2008 was 360 MW with estimated DR potential of 45-90 MW, actual achieved was much less due to low participation. Efforts to overcome barriers to increased participation may include, improved marketing and recruitment of potential DR sites, better alignment and emphasis on financial benefits of participation, and use of Auto-DR to increase consistency of participation.

Goli, Sasank; McKane, Aimee; Olsen, Daniel

2011-06-14T23:59:59.000Z

400

DOE Publishes Notice of Proposed Rulemaking for Commercial Refrigeration Equipment Test Procedure  

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

The Department of Energy has published a notice of proposed rulemaking regarding test procedures for commercial refrigeration equipment.

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Investigation of a Single Stage Four-Valve Pulse Tube Refrigerator for High Cooling Power  

Science Journals Connector (OSTI)

We discuss the optimization of a pulse tube refrigerator for high cooling power. Our approach is to increase the system...

T. Schmauder; A. Waldauf; M. Thürk; R. Wagner; P. Seidel

2002-01-01T23:59:59.000Z

402

DOE/EA-1643: Environmental Assessment for 10 CFR 431 Commercial Refrigeration Equipment (December 2008)  

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

ENVIRONMENTAL ASSESSMENT FOR ENVIRONMENTAL ASSESSMENT FOR 10 CFR Part 431 Energy Conservation Program for Commercial and Industrial Equipment: Energy Conservation Standards for Commercial Ice-Cream Freezers; Self-Contained Commercial Refrigerators, Commercial Freezers, and Commercial Refrigerator- Freezers without Doors; and Remote Condensing Commercial Refrigerators, Commercial Freezers, and Commercial Refrigerator-Freezers December 2008 CHAPTER 16. ENVIRONMENTAL IMPACT ANALYSIS TABLE OF CONTENTS 16.1 INTRODUCTION ............................................................................................................ 16-1 16.2 AIR QUALITY ANALYSIS ............................................................................................ 16-1

403

New compressor systems seen paring refrigeration costs 15%  

SciTech Connect

Manufacturers claim that a parallel arrangement of three to five compressors of varying capacities can lower a store's refrigerating costs over 15%. The energy savings come from the more-precise matching of compressor capacity with refrigeration demand. The 500 stores that have installed uneven compressor systems are achieving a payback in under a year. Because it is important for controls to match a system for maximum efficiency, manufacturers are introducing tailor-made microprocessor controllers. A table summarizes three supermarket case histories. (DCK)

Barber, J.

1983-05-09T23:59:59.000Z

404

Supermarket with Ground Coupled Carbon Dioxide Refrigeration Plant  

E-Print Network (OSTI)

refrigeration remains the last big subsector and the strongest emission source of the fluorinated hydrocarbons (HFC) in Germany? - Kauffeld [4] About 65 % of the cooling needs in Germany for frozen and refrigerated food products ? over 50.000 GWh.../a [2] In 2011, 72.4 % of the sales share of food retail industry realized in discounters and supermarkets in Germany [1] Supermarket: ? 600 ? 2.000 kWh/m2.a (PE) [3] Normal building: 200 ? 400 kWh/m2.a (PE) [4] [1] EHI retail institute 2012...

Rehault, N.

2012-01-01T23:59:59.000Z

405

Magnetic refrigeration apparatus with belt of ferro or paramagnetic material  

DOE Patents (OSTI)

A magnetic refrigerator operating in the 12 to 77 K range utilizes a belt which carries ferromagnetic or paramagnetic material and which is disposed in a loop which passes through the center of a solenoidal magnet to achieve cooling. The magnetic material carried by the belt, which can be blocks in frames of a linked belt, can be a mixture of substances with different Curie temperatures arranged such that the Curie temperatures progressively increase from one edge of the belt to the other. This magnetic refrigerator can be used to cool and liquefy hydrogen or other fluids.

Barclay, J.A.; Stewart, W.F.; Henke, M.D.; Kalash, K.E.

1986-04-03T23:59:59.000Z

406

The growth rate of gas hydrate from refrigerant R12  

SciTech Connect

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

407

RHEOLOGICAL STUDY OF TWO-PHASE SECONDARY FLUIDS FOR REFRIGERATION AND AIR CONDITIONING.  

E-Print Network (OSTI)

, indirect refrigeration systems renews interest as they enable to notably reduce the use of environmental the refrigeration applications to the air-conditioning systems. However, this kind of process only remainsRHEOLOGICAL STUDY OF TWO-PHASE SECONDARY FLUIDS FOR REFRIGERATION AND AIR CONDITIONING. Mylène

Boyer, Edmond

408

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

409

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

410

Balancing Energy Consumption and Food Quality Loss in Supermarket Refrigeration System  

E-Print Network (OSTI)

Balancing Energy Consumption and Food Quality Loss in Supermarket Refrigeration System J. Cai and J- tion of commercial refrigeration system, featuring balanced system energy consumption and food quality energy consumption and food quality loss, at varying ambient condition, in a supermarket refrigeration

Skogestad, Sigurd

411

Estimation of exhaust gas aerodynamic force on the variable geometry turbocharger actuator: 1D flow model approach  

Science Journals Connector (OSTI)

Abstract This paper provides a reliable tool for simulating the effects of exhaust gas flow through the variable turbine geometry section of a variable geometry turbocharger (VGT), on flow control mechanism. The main objective is to estimate the resistive aerodynamic force exerted by the flow upon the variable geometry vanes and the controlling actuator, in order to improve the control of vane angles. To achieve this, a 1D model of the exhaust flow is developed using Navier–Stokes equations. As the flow characteristics depend upon the volute geometry, impeller blade force and the existing viscous friction, the related source terms (losses) are also included in the model. In order to guarantee stability, an implicit numerical solver has been developed for the resolution of the Navier–Stokes problem. The resulting simulation tool has been validated through comparison with experimentally obtained values of turbine inlet pressure and the aerodynamic force as measured at the actuator shaft. The simulator shows good compliance with experimental results.

Fayez Shakil Ahmed; Salah Laghrouche; Adeel Mehmood; Mohammed El Bagdouri

2014-01-01T23:59:59.000Z

412

2014-07-10 Issuance: Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers; Final Rule Correction  

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

This document is a pre-publication Federal Register final rule correction regarding test procedures for refrigerators, refrigerator-freezers, and freezers, as issued by the Deputy Assistant Secretary for Energy Efficiency on July 10, 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.

413

Low-frequency variability and heat transport in a low-order nonlinear coupled ocean-atmosphere model  

E-Print Network (OSTI)

We formulate and study a low-order nonlinear coupled ocean-atmosphere model with an emphasis on the impact of radiative and heat fluxes and of the frictional coupling between the two components. This model version extends a previous 24-variable version by adding a dynamical equation for the passive advection of temperature in the ocean, together with an energy balance model. The bifurcation analysis and the numerical integration of the model reveal the presence of low-frequency variability (LFV) concentrated on and near a long-periodic, attracting orbit. This orbit combines atmospheric and oceanic modes, and it arises for large values of the meridional gradient of radiative input and of frictional coupling. Chaotic behavior develops around this orbit as it loses its stability; this behavior is still dominated by the LFV on decadal and multi-decadal time scales that is typical of oceanic processes. Atmospheric diagnostics also reveals the presence of predominant low- and high-pressure zones, as well as of a subtropical jet; these features recall realistic climatological properties of the oceanic atmosphere. Finally, a predictability analysis is performed. Once the decadal-scale periodic orbits develop, the coupled system's short-term instabilities --- as measured by its Lyapunov exponents --- are drastically reduced, indicating the ocean's stabilizing role on the atmospheric dynamics. On decadal time scales, the recurrence of the solution in a certain region of the invariant subspace associated with slow modes displays some extended predictability, as reflected by the oscillatory behavior of the error for the atmospheric variables at long lead times.

Stéphane Vannitsem; Jonathan Demaeyer; Lesley De Cruz; Michael Ghil

2014-12-01T23:59:59.000Z

414

Modelling repairable system reliability with explanatory variables and repair and maintenance actions  

Science Journals Connector (OSTI)

......hazards modeling in reliability analysis-an application to...model to light water reactor component failure data...SGATTI,S.(2003) Reliability in automotive electronics...1972a) The statistical analysis of dependencies in point......

Diederik Lugtigheid; agan Banjevic; Andrew K. S. Jardine

2004-04-01T23:59:59.000Z

415

Stochastic models of the meridional overturning circulation: time scales and patterns of variability  

Science Journals Connector (OSTI)

...model captures the essential physics of the advective feedback bistability...to a Theme Issue Stochastic physics and climate modelling. Figure...038501 . Gardiner, C.W Handbook of stochastic methods for physics, chemistry, and the natural...

2008-01-01T23:59:59.000Z

416

Mechanisms of aerosol-forced AMOC variability in a state of the art climate model  

E-Print Network (OSTI)

with a new state-of-the-art Earth system model. Anthropogenic aerosols have previously been highlighted anthropogenic aerosols force a strengthening of the AMOC by up to 20% in our state-of-the-art Earth system model

417

A New Variable Modified Chaplygin Gas Model Interacting with Scalar Field  

E-Print Network (OSTI)

In this letter we present a new form of the well known Chaplygin gas model by introducing inhomogeneity in the EOS. This model explains $\\omega=-1$ crossing. Also we have given a graphical representation of the model using $\\{r,s\\}$ parameters. We have also considered an interaction of this model with the scalar field by introducing a phenomenological coupling function and have shown that the potential decays with time.

Writambhara Chakraborty; Ujjal Debnath

2010-06-11T23:59:59.000Z

418

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic Controlled Variable Selection  

E-Print Network (OSTI)

Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no structure that leads to optimal economic operation, while promptly rejecting disturbances at lower layers

Skogestad, Sigurd

419

Continuous-time random-walk model of transport in variably saturated heterogeneous porous media  

Science Journals Connector (OSTI)

We propose a unified physical framework for transport in variably saturated porous media. This approach allows fluid flow and solute migration to be treated as ensemble averages of fluid and solute particles, respectively. We consider the cases of homogeneous and heterogeneous porous materials. Within a fractal mobile-immobile continuous time random-walk framework, the heterogeneity will be characterized by algebraically decaying particle retention times. We derive the corresponding (nonlinear) continuum-limit partial differential equations and we compare their solutions to Monte Carlo simulation results. The proposed methodology is fairly general and can be used to track fluid and solutes particles trajectories for a variety of initial and boundary conditions.

Andrea Zoia; Marie-Christine Néel; Andrea Cortis

2010-03-04T23:59:59.000Z

420

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

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

422

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

423

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

424

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

425

Automated control and data acquisition for a small dilution refrigerator  

Science Journals Connector (OSTI)

An automatic temperature controller and data acquisition system for use with a dilution refrigerator is described. The unit is controlled by a 16?bit home microcomputer and operates and reads a resistance bridge capacitance bridge and temperature controller. Interfacing is achieved with common components and minimum additional wiring. Flexibility is retained in the software to allow application to several types of measurements.

David G. Haase

1981-01-01T23:59:59.000Z

426

Superefficient Refrigerators: Opportunities and Challenges for Efficiency Improvement Globally  

SciTech Connect

As an energy-intensive mainstream product, residential refrigerators present a significant opportunity to reduce electricity consumption through energy efficiency improvements. Refrigerators expend a considerable amount of electricity during normal use, typically consuming between 100 to 1,000 kWh of electricity per annum. This paper presents the results of a technical analysis done for refrigerators in support of the Super-efficient Equipment and Appliance Deployment (SEAD) initiative. Beginning from a base case representative of the average unit sold in India, we analyze efficiency improvement options and their corresponding costs to build a cost-versus-efficiency relationship. We then consider design improvement options that are known to be the most cost effective and that can improve efficiency given current design configurations. We also analyze and present additional super-efficient options, such as vacuum-insulated panels. We estimate the cost of conserved electricity for the various options, allowing flexible program design for market transformation programs toward higher efficiency. We estimate ~;;160TWh/year of energy savings are cost effective in 2030, indicating significant potential for efficiency improvement in refrigerators in SEAD economies and China.

Shah, Nihar; Park, Won Young; Bojda, Nicholas; McNeil, Michael A.

2014-08-01T23:59:59.000Z

427

A Miniature Helium Turbo-Expander for Cryogenic Refrigeration Systems  

Science Journals Connector (OSTI)

Publisher Summary This chapter highlights the features of a miniature helium turbo expander for cryogenic refrigeration systems. The Cryogenic Engineering Laboratory of the National Bureau of Standards has investigated the use of small, high speed turbines, supported by gas lubricated journal bearings, in small capacity refrigeration system. Two systems have been studied, one that operates at 4.2 K and another at 30 K. As a result of optimization studies, a 20:1 pressure ratio was used for the 4.2 K system. It is found that although the final low temperature is obtained with an expansion valve, work extraction is necessary for system operation. Refrigeration at 30 K is accomplished by shutting the expansion valve, and leaving the low temperature loop of the system unused. Refrigeration is obtained downstream of the turbine. It is found that for this system, optimization studies indicated best performance at 4:1 pressure ratio. A program was initiated to investigate the performance of a 4:1 pressure ratio turbine for this application. A design goal of 70% was selected from the qualitative reasoning that in larger sizes 80 to 90% was common, but in small machines friction and leakage losses tend to be relatively high.

M.T. NORTON

1965-01-01T23:59:59.000Z

428

Removing Odors from Refrigerators and Freezers after Food has Spoiled  

E-Print Network (OSTI)

ER-005 6-06 Extension Family and Consumer Science Specialists The Texas A&M University System If food has spoiled in a refrigerator or freezer because of a power failure or some other reason, undesirable odors can develop. To eliminate these odors...

FCS Project Team - FDRM UNIT

2005-09-30T23:59:59.000Z

429

X-RAY VARIABILITY COHERENCE: HOW TO COMPUTE IT, WHAT IT MEANS, AND HOW IT CONSTRAINS MODELS OF GX 339 4 AND CYGNUS X-1  

E-Print Network (OSTI)

X-RAY VARIABILITY COHERENCE: HOW TO COMPUTE IT, WHAT IT MEANS, AND HOW IT CONSTRAINS MODELS OF GX of the spectrum and variability of X-ray binaries. Here we present a procedure for estimating the coherence and GX 339 4 and find that the near-perfect coherence between low- and high-energy X-ray photons rules

Faraon, Andrei

430

Leducq, Roche, Macchi-Tejeda , Fournaison, Guilpart Workshop on Refrigerant Charge Reduction, Cemagref Antony, France, 2009 1  

E-Print Network (OSTI)

Leducq, Roche, Macchi-Tejeda , Fournaison, Guilpart IIR 1st Workshop on Refrigerant Charge, Antony cedex, 92 163,, France denis.leducq@cemagref.fr ABSTRACT A design of a low charge refrigerating on refrigerant charge and energy performance has been evaluated experimentally for a cold room refrigerating unit

Paris-Sud XI, Université de

431

Refrigerator and Solenoid Run Summary August/September 1999  

SciTech Connect

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

432

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

SciTech Connect

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

Lowe, K.T.

2005-10-07T23:59:59.000Z

433

Magnetized String Cosmological Model in Cylindrically Symmetric Inhomogeneous Universe with Variable Cosmological-Term $?$  

E-Print Network (OSTI)

Cylindrically symmetric inhomogeneous magnetized string cosmological model is investigated with cosmological term $\\Lambda$ varying with time. To get the deterministic solution, it has been assumed that the expansion ($\\theta$) in the model is proportional to the eigenvalue $\\sigma^{1}_{1}$ of the shear tensor $\\sigma^{i}_{j}$. The value of cosmological constant for the model is found to be small and positive which is supported by the results from recent supernovae Ia observations. The physical and geometric properties of the model are also discussed in presence and absence of magnetic field.

Anirudh Pradhan

2007-08-01T23:59:59.000Z

434

ResPoNSe: modeling the wide variability of residential energy consumption.  

E-Print Network (OSTI)

affect appliance energy consumption. For example, differentStates, 2005 Residential Energy Consumption Survey: HousingModeling of End-Use Energy Consumption in the Residential

Peffer, Therese; Burke, William; Auslander, David

2010-01-01T23:59:59.000Z

435

Investigating ionized disc models of the variable narrow-line Seyfert 1 PG 1404+226  

E-Print Network (OSTI)

We investigate the use of relativistically blurred photoionized disc models on an XMM-Newton observation of the Narrow Line Seyfert 1 galaxy PG 1404+226. The model is designed to reproduce the radiation from the inner accretion disc around a Kerr black hole, and is more successful at fitting the spectrum than models based on a thermal soft excess. The source varies strongly over the course of the observation, and the disc model works over all observed flux states. We conclude that it is a useful tool in the study of certain quasars.

J. Crummy; A. C. Fabian; W. N. Brandt; Th. Boller

2005-06-06T23:59:59.000Z

436

Multiple thermohaline states due to variable di usivity in a hierarchy of simple models.  

E-Print Network (OSTI)

of under-resolved FG models is constructed, the simplest of which is an eight-cell cube, to connect the two

Edwards, Neil

437

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

438

Validation of the state-space model of fatigue crack growth in ductile alloys under variable-amplitude load via comparison of the crack-opening stress data  

Science Journals Connector (OSTI)

A state-space model of fatigue crack growth in ductile alloys under variable-amplitude load was presented by Patankar and Ray (Patankar...International Journal of Fracture, 90, 235--249; Patankar and Ray (2000).

Ravindra Patankar; Rong Qu

2005-02-01T23:59:59.000Z

439

Accounting for the Occupancy Variable in Inverse Building Energy Baselining Models  

E-Print Network (OSTI)

in Figure 1. Figure 2 shows the typical load shapes for lighting and equipment for the specified daytypes. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1357911131517192123 Hour Density Average Weekday Average Weekend and Vacation Average Semester Break Weekday... variable against the lighting and equipment load shapes produced profiles reasonably similar to the occupancy profiles obtained by a walk-through survey, which shows the strong correlation between them. y = 1.721x - 0.8976 R2 = 0.9267 0 0.1 0.2 0.3 0.4 0...

Claridge, D. E.

2001-01-01T23:59:59.000Z

440

Accounting for Unresolved Spatial Variability in Large Scale Models: Development and Evaluation of a Statistical Cloud Parameterization with Prognostic Higher Order Moments  

SciTech Connect

This project focused on the variability of clouds that is present across a wide range of scales ranging from the synoptic to the millimeter. In particular, there is substantial variability in cloud properties at scales smaller than the grid spacing of models used to make climate projections (GCMs) and weather forecasts. These models represent clouds and other small-scale processes with parameterizations that describe how those processes respond to and feed back on the largescale state of the atmosphere.

Robert Pincus

2011-05-17T23:59:59.000Z

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--Three-Year Results with Third-Generation Blowing Agents  

SciTech Connect

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and -10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first three years of a multi-year aging study. Preliminary comparisons of measured data with predictions of a mathematical aging model are presented.

Wilkes, K.E.

2001-05-29T23:59:59.000Z

442

Aging of Polyurethane Foam Insulation in Simulated Refrigerator Panels--Two-Year Results with Third-Generation Blowing Agents  

SciTech Connect

Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements--HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 F, 40 F, and {minus}10 F. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first two years of a multi-year aging study. Preliminary comparisons of measured data with predictions of a mathematical aging model are presented.

Wilkes, K.E.

2001-02-14T23:59:59.000Z

443

Accounting for biological variability and sampling scale: a multi-scale approach to building epidemic models  

Science Journals Connector (OSTI)

...sedentary, by developing a multi-scale framework...individuals within families (or other social units...within parishes). The multi-scale framework developed...and sampling scale: a multi-scale approach to building epidemic models...

2007-01-01T23:59:59.000Z

444

A melting model for variably depleted and enriched lherzolite in the plagioclase and spinel stability fields  

E-Print Network (OSTI)

Here we develop a lherzolite melting model and explore the effects of variations in mantle composition, pressure, temperature, and H[subscript 2]O content on melt composition. New experiments and a compilation of experimental ...

Till, Christy B.

445

Representing Variability in Subgrid Snow Cover and Snow Depth in a Global Land Model: Offline Validation  

Science Journals Connector (OSTI)

Subgrid snow cover is one of the key parameters in global land models since snow cover has large impacts on the surface energy and moisture budgets, and hence the surface temperature. In this study, the Subgrid Snow Distribution (SSNOWD) snow ...

T. Nitta; K. Yoshimura; K. Takata; R. O’ishi; T. Sueyoshi; S. Kanae; T. Oki; A. Abe-Ouchi; G. E. Liston

2014-05-01T23:59:59.000Z

446

Modeling variability in {sup 210}Pb and sediment fluxes near the Whites Point Outfalls, Palos Verdes Shelf, California  

SciTech Connect

Many researchers have had difficulty interpreting sediment data collected from the Palos Verdes Shelf, southern California. Factors that have been difficult to reconcile include the distribution of {sup 210}Pb and metals, the depth and extent of bioturbation, and the rate of sedimentation. This paper presents a simple model that includes these elements and simulates the flux of {sup 210}Pb, sediment, and metals to the sea floor near the Whites Point wastewater outfalls. The model uses known particle and metals emission rates from the outfalls and {sup 210}Pb fluxes to the sediments that vary in proportion to the flux of sediment mass to the sea floor. Model-predicted metals and {sup 210}Pb concentration profiles in the sediments agree well with data from cores collected at three locations on the Palos Verdes Shelf between 1972 and 1997. The implication of the model results is that {sup 210}Pb fluxes to the sediments in this area have varied greatly over the past 60 years. The model suggests that subsurface {sup 210}Pb maxima and uniform {sup 210}Pb concentrations to depths within the sediments of roughly 30 cm have resulted from time-variable {sup 210}Pb fluxes to the sediments and relatively shallow bioturbation and that natural sedimentation rates are relatively high.

Paulsen, S.C.; List, E.J. [Flow Science Inc., Pasadena, CA (United States)] [Flow Science Inc., Pasadena, CA (United States); Santschi, P.H. [Texas A and M Univ., Galveston, TX (United States). Dept. of Oceanography] [Texas A and M Univ., Galveston, TX (United States). Dept. of Oceanography

1999-09-15T23:59:59.000Z

447

An investigation of the sub-grid variability of trace gases and aerosols for global climate modeling  

SciTech Connect

One fundamental property and limitation of grid based models is their inability to identify spatial details smaller than the grid cell size. While decades of work have gone into developing sub-grid treatments for clouds and land surface processes in climate models, the quantitative understanding of sub-grid processes and variability for aerosols and their precursors is much poorer. In this study, WRF-Chem is used to simulate the trace gases and aerosols over central Mexico during the 2006 MILAGRO field campaign, with multiple spatial resolutions and emission/terrain scenarios. Our analysis focuses on quantifying the sub-grid variability (SGV) of trace gases and aerosols within a typical global climate model grid cell, i.e. 75x75 km2. Our results suggest that a simulation with 3-km horizontal grid spacing adequately reproduces the overall transport and mixing of trace gases and aerosols downwind of Mexico City, while 75-km horizontal grid spacing is insufficient to represent local emission and terrain-induced flows along the mountain ridge, subsequently affecting the transport and mixing of plumes from nearby sources. Therefore, the coarse model grid cell average may not correctly represent aerosol properties measured over polluted areas. Probability density functions (PDFs) for trace gases and aerosols show that secondary trace gases and aerosols, such as O3, sulfate, ammonium, and nitrate, are more likely to have a relatively uniform probability distribution (i.e. smaller SGV) over a narrow range of concentration values. Mostly inert and long-lived trace gases and aerosols, such as CO and BC, are more likely to have broad and skewed distributions (i.e. larger SGV) over polluted regions. Over remote areas, all trace gases and aerosols are more uniformly distributed compared to polluted areas. Both CO and O3 SGV vertical profiles are nearly constant within the PBL during daytime, indicating that trace gases are very efficiently transported and mixed vertically by turbulence. But, simulated horizontal variability indicates that trace gases and aerosols are not well mixed horizontally in the PBL. During nighttime the SGV for trace gases is maximum at the surface, and quickly decreases with height. Unlike the trace gases, the SGV of BC and secondary aerosols reaches a maximum at the PBL top during the day. The SGV decreases with distance away from the polluted urban area, has a more rapid decrease for long-lived trace gases and aerosols than for secondary ones, and is greater during daytime than nighttime. The SGV of trace gases and aerosols is generally larger than for meteorological quantities. Emissions can account for up to 50% of the SGV over urban areas such as Mexico City during daytime for less-reactive trace gases and aerosols, such as CO and BC. The impact of emission spatial variability on SGV decays with altitude in the PBL and is insignificant in the free troposphere. The emission variability affects SGV more significantly during daytime (rather than nighttime) and over urban (rather than rural or remote) areas. The terrain, through its impact on meteorological fields such as wind and the PBL structure, affects dispersion and transport of trace gases and aerosols and their SGV.

Qian, Yun; Gustafson, William I.; Fast, Jerome D.

2010-07-29T23:59:59.000Z

448

An experimental analysis of cycling losses in domestic refrigerator-freezers  

SciTech Connect

This paper identifies and quantifies the cycling losses in a domestic refrigerator-freezer. During cycling operation the refrigerator was found to operate between 5% and 25% less efficiently than the corresponding quasi-steady machine. The cycling refrigerator operates with an evaporator capacity between 3% and 17% less than that of the quasi-steady refrigerator while at the same time requiring between 1% and 9% more power to operate. This refrigerator performance degradation was attributed to several factors, the most important being the refrigerant migration and the thermal mass of the evaporator and compressor. During the off-cycle, refrigerant migrates from the condenser to the evaporator as the system pressures equalize. The off-cycle migration increases the temperature of the evaporator and necessitates refrigerant redistribution during the on-cycle and thereby tends to reduce system performance. The increased power requirements, traced to the compressor, result from slight differences in system pressure and the reduced compressor efficiency due to a cool compressor. With the cycling losses identified, several possible refrigerator design changes were suggested. It appears that a refrigerator equipped with a reciprocating compressor, solenoid valves to isolate the condenser, and no accumulator should operate in a nearly quasi-steady manner.

Coulter, W.H. [DuPont Co., Belle, WV (United States); Bullard, C.W. [Univ. of Illinois, Urbana, IL (United States). Air Conditioning and Refrigeration Center

1997-12-31T23:59:59.000Z

449

Energy and global warming impacts of next generation refrigeration and air conditioning technologies  

SciTech Connect

Significant developments have occurred in hydrofluorocarbon (HFC) and the application of ammonia and hydrocarbons as refrigerant working fluids since the original TEWI (Total Equivalent Warming Impact) report in 1991. System operating and performance data on alternative refrigerants and refrigeration technologies justify and updated evaluation of these new alternative refrigerants and competing technologies in well-characterized applications. Analytical and experimental results are used to show quantitative comparisons between HFCS, HFC blends, hydrocarbons, and ammonia, used as refrigerants. An objective evaluation is presented for commercial and near commercial non-CFC refrigerants/blowing agents and alternative refrigeration technologies. This information is needed for objective and quantitative decisions on policies addressing greenhouse gas emissions from refrigeration and air conditioning equipment. The evaluation assesses the energy use and global warming impacts of refrigeration and air conditioning technologies that could be commercialized during the phase out of HCFCS. Quantitative comparison TEWI for two application areas are presented. Opportunities for significant reductions in TEWI are seen with currently known refrigerants through improved maintenance and servicing practices and improved product designs.

Sand, J.R.; Fischer, S.K.; Baxter, V.D.

1996-10-01T23:59:59.000Z

450

Advances of Modeling Water Flow in Variably Saturated Soils with SWAP  

Science Journals Connector (OSTI)

...any user-specified grid density to allow local...that the ecosystem would benefit from higher groundwater...might be bridged with smart one-dimensional models...2007). These studies benefit greatly from reliable...G. Lachaud. 1995. Estimating sparse forest rainfall...

Jos C. van Dam; Piet Groenendijk; Rob F.A. Hendriks; Joop G. Kroes

451

Modelling repairable system reliability with explanatory variables and repair and maintenance actions  

Science Journals Connector (OSTI)

......However, in general, in RMs...overhaul of an engine (a midlife...used with diesel engines...g. from diesel engines, such as...is a quite general model, and...analysis of diesel engine failure data...systems with general repair......

Diederik Lugtigheid; agan Banjevic; Andrew K. S. Jardine

2004-04-01T23:59:59.000Z

452

Process-Driven Feature Modeling for Variability Management of Project Environment Configurations  

E-Print Network (OSTI)

.winkler}@tuwien.ac.at ABSTRACT Technical projects environments, i.e., sets of methods and tools that support an engineering. For designing an effective and efficient engineering project environment, project managers and engineering of engineering project environment configurations and present a conceptual approach using semantic modeling

453

Canonical quantization of a minisuperspace model for gravity using self-dual variables  

E-Print Network (OSTI)

The present article summarizes the work of the papers \\cite{1} dealing with the quantization of pure gravity and gravity coupled to a Maxwell field and a cosmological constant in presence of spherical symmetry. The class of models presented is intended as an interesting testing ground for the quantization of full 3+1 gravity. We are working in Ashtekar's self-dual representation.

T. Thiemann

1999-10-04T23:59:59.000Z

454

Development of models for series and parallel fan variable air volume terminal units  

E-Print Network (OSTI)

for the series and parallel units, with coefficients varying by size and manufacturer. Statistical modeling utilized SAS software (2002). Fan power and airflow data were collected at downstream static pressures over a range from 0.1 to 0.5 in. w.g. (25 to 125 Pa...

Furr, James C., Jr

2007-09-17T23:59:59.000Z

455

Guidelines on Airflow and Refrigerant Charge Verification and Diagnostics  

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

GUIDELINES ON AIRFLOW AND GUIDELINES ON AIRFLOW AND REFRIGERANT CHARGE VERIFICATION AND DIAGNOSTICS Alliance for Residential Building Innovation David Springer, Davis Energy Group Context  Airflow and refrigerant charge defects in existing air conditioning systems are well documented  Failure to address these problems represents a missed opportunity for home performance contractors  To ensure cost-effective solutions, a systematic approach is needed to quickly and accurately diagnose and resolve problems  Target:  Home performance contractors  HVAC contractors & technicians The Impact of Defects Non-TXV TXV 15% duct leakage 1 -18.10% 23% low airflow -4.70% 50% condenser coil blockage -5.80% 50% evaporator coil blockage 2 -4.60% -4.20% 20% overcharge -3.50% -7.90%

456

Guide for the selection of supermarket refrigeration systems  

SciTech Connect

This report presents an evaluation of supermarket refrigeration involving the use of conventional and multiplex compressor systems. Computer simulations of these systems were performed for six representative sites. The performance predictions generated in this fashion were tabulated to allow hand calculation of electric costs for any prevailing electric rate schedule. A methodology was also developed to allow economic assessment of the conventional and multiplex systems and of various enhancements employed with the multiplex system. The results of the evaluation showed the multiplex refrigeration system produced a reasonable payback for all sites examined, depending upon the enhancements employed. System features that had the greatest impact on payback were heat reclaim, hot gas defrost, and floating head pressure. 25 figs., 28 tabs.

Walker, D.H.; Tsaros, T.L.; Deming, G.I. (Foster-Miller, Inc., Waltham, MA (USA))

1990-03-01T23:59:59.000Z

457

IMPROVEMENTS OF HELIUM LIQUEFACTION/REFRIGERATION PLANTS AND APPLICATIONS  

Science Journals Connector (OSTI)

Design features for a new range of helium liquefiers and refrigerators with capacities ranging from 30 to 280 l/h of liquid helium (LHe) and 100 to 900 Watt respectively. The latest He cold box development shows an increased efficiency due to improved turbine and heat exchanger design. Other benefits of the new design include short cool-down times and a very compact design which offers better flexibility and process control. The modularity of the system was designed in order to cover a wide range of applications like sophisticated shield cooling at different temperature levels or simultaneous operation modes for He liquefaction and refrigeration purposes. The presentation will highlight the individual improvements in the design.

K.-H. Berdais; H. Wilhelm; Th. Ungricht

2008-01-01T23:59:59.000Z

458

Multi-variable optimisation of PEMFC cathodes based on surrogate modelling  

Science Journals Connector (OSTI)

Abstract A two-dimensional, steady state, isothermal agglomerate model for cathode catalyst layer design is presented. The design parameters, platinum loading, platinum mass ratio, electrolyte volume fraction, thickness of catalyst layer and agglomerate radius, are optimised by a multiple surrogate model and their sensitivities are analysed by a Monte Carlo method based approach. Two optimisation strategies, maximising the current density at a fix cell voltage and during a specific range, are implemented for the optima prediction. The results show that the optimal catalyst composition depends on operating cell voltages. At high current densities, the performance is improved by reducing electrolyte volume fraction to 7.0% and increasing catalyst layer porosity to 52.9%. At low current densities, performance is improved by increasing electrolyte volume fraction to 50.0% and decreasing catalyst layer porosity to 12.0%. High platinum loading and small agglomerate radius improve current density at all cell voltages. The improvement in fuel cell performance is analysed in terms of the electrolyte coating thickness, agglomerate specific area, conductivity, overpotential, volumetric current density and oxygen mole fraction within the cathode catalyst layer. The optimisation results are also validated by the agglomerate model at different cell voltages to confirm the effectiveness of the proposed methodologies.

Lei Xing; Xueguan Song; Keith Scott; Volker Pickert; Wenping Cao

2013-01-01T23:59:59.000Z

459

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

460

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

Note: This page contains sample records for the topic "modeling variable refrigerant" 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

Waste-heat-driven refrigeration plants for freezer trawlers  

SciTech Connect

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

462

Aluminum tunnel junction detector operation in an adiabatic demagnetization refrigerator  

SciTech Connect

Superconducting tunnel junction detectors are being developed as both particle and X-ray detectors. Aluminum junctions are desirable for detectors because of their strong native oxide barriers, and because the small energy gap of aluminum is a good match to ballistic phonons generated by particle interactions in single crystals of silicon or other low acoustic-loss insulating crystals. Aluminum tunnel junction detectors must be operated near 0.1 T{sub C} which is 110 mK for aluminum. To operate detectors at these temperatures, we have developed adiabatic demagnetization refrigerators (ADRs) for the laboratory and prototype ADRs for space based operation. These cryogenic systems are simpler, more convenient and more portable than most dilution refrigerators. We have demonstrated that the magnetic field of the ADR need not compromise the performance of aluminum tunnel junctions. We have recently initiated a program to develop superconducting tunnel junctions (STJs) as high resolution X-ray detectors and low energy threshold particle detectors. This complements our existing program in which we are developing high resolution X-ray microcalorimeter detectors. One of our goals for both of these cryogenic detector development efforts is to observe X-ray emission from cosmic sources. This requires a refrigeration system that can operate under zero gravity space flight conditions. For the microcalorimeter project, temperatures of 100 mK and below are required to sufficiently reduce the heat capacity of the device. We have therefore developed an adiabatic demagnetization refrigerator (ADR) system which can be configured for space flight.

Labov, S.; Silver, E.; Le Gros, M. (Lawrence Livermore National Lab., CA (United States)); Bland, R.W.; Dickson, S.C.; Dignan, T.G.; Laws, K.; Johnson, R.T.; Simon, M.W.; Stricker, D.A.; Watson, R.M. (San Francisco State Univ., CA (United States)); Madden, N.; Landis, D. (Lawrence Berkeley Lab., CA (United States))

1992-01-30T23:59:59.000Z

463

Novel 4-Way Refrigerant Reversing Valve for Heat Pumps  

SciTech Connect

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

464

Potential of the tractor-trailer and container segments as entry markets for a proposed refrigeration technology  

SciTech Connect

The refrigerated trailer and container segments of the transportation industry are evaluated as potential entry markets for a proposed absorption refrigeration technology. To perform this analysis the existing transportation refrigeration industry is characterized; this includes a description of the current refrigeration technology, rating systems, equipment manufacturers, maintenance requirements, and sales trends. This information indicates that the current transportation refrigeration industry is composed of two major competitors, Thermo King and Carrier. In addition, it has low profit potential, some barriers to entry and low growth potential. Data are also presented that characterize the transportation refrigeration consumers, specifically, major groups, market segmentation, consumer decision process, and buying criteria. This consumer information indicates that the majority of refrigerated trailer consumers are private carriers, and that the majority of refrigerated container consumers are shipping companies. Also, these consumers are primarily interested in buying reliable equipment at a low price, and are quite satisfied with existing refrigeration equipment.

Smith, S.A.; Davis, L.J.; Garrett, B.A.

1987-05-01T23:59:59.000Z

465

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

SciTech Connect

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-Technology’s 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

466

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

467

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

SciTech Connect

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

468

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

469

An analytical model for flame propagation in low-Mach-number, variable-density flow  

SciTech Connect

Flame propagation is relevant in many practical applications involving heat transfer and the conversion of heat into mechanical work. Examples of such applications include spark-ignition engines, turbojets, ramjets, afterburners and rockets, although these devices may exhibit nonlocal and nonpropagating combustion phenomena as well. Here, a simple model problem is formulated to describe the coupling between premixed-flame and flow-field dynamics resulting from gas expansion within the flame. The energy conservation equation is integrated analytically across the flame in order to reduce the number of governing equations for the computational problem. A system of six equations and associated boundary conditions are formulated for computation of the time evolution of an initially prescribed three-dimensional velocity field and the flame surface.

Aldredge, R.C. [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aeronautical Engineering] [Univ. of California, Davis, CA (United States). Dept. of Mechanical and Aeronautical Engineering

1997-12-01T23:59:59.000Z

470

Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 2  

SciTech Connect

Lubrication properties of refrigeration lubricants were investigated in high pressure nonconforming contacts under different conditions of temperature, rolling speed, and refrigerant concentration. The program was based upon the recognition that the lubrication regime in refrigeration compressors is generally elastohydrodynamic or hydrodynamic, as determined by the operating conditions of the compressor and the properties of the lubricant. Depending on the compressor design, elastohydrodynamic lubrication conditions exist in many rolling and sliding elements of refrigeration compressors such as roller element bearings, gears, and rotors. The formation of an elastohydrodynamic film separating rubbing surfaces is important in preventing the wear and failure of compressor elements. It is, therefore, important to predict the elastohydrodynamic (EHD) performance of lubricants under realistic tribocontact renditions. This is, however, difficult as the lubricant properties that control film formation are critically dependent upon pressure and shear, and cannot be evaluated using conventional laboratory instruments. In this study, the elastohydrodynamic behavior of refrigeration lubricants with and without the presence of refrigerants was investigated using the ultrathin film EHD interferometry technique. This technique enables very thin films, down to less than 5 nm, to be measured accurately within an EHD contact under realistic conditions of temperature, shear, and pressure. The technique was adapted to the study of lubricant refrigerant mixtures. Film thickness measurements were obtained on refrigeration lubricants as a function of speed, temperature, and refrigerant concentration. The effects of lubricant viscosity, temperature, rolling speed, and refrigerant concentration on EHD film formation were investigated. From the film thickness measurements, effective pressure-viscosity coefficients were calculated. The lubricants studied in this project included two naphthenic mineral oils (NMO), four polyolesters (POE), and two polyvinyl ether (PVE) fluids. These fluids represented viscosity grades of ISO 32 and ISO 68 and are shown in a table. Refrigerants studied included R-22, R-134a, and R-410A. Film thickness measurements were conducted at 23 C, 45 C, and 65 C with refrigerant concentrations ranging from zero to 60% by weight.

Gunsel, Selda; Pozebanchuk, Michael

1999-04-01T23:59:59.000Z

471

Using R-134a and R-22 in supermarket refrigeration applications  

SciTech Connect

This article reports on tests of the performance of refrigerants R-134a and R-22 in medium and low temperature refrigeration systems. These tests were performed to determine the accuracy of predictions that R-134a would be a suitable replacement for CFC refrigerants in supermarkets. The testing resulted in extensive modifications to compressors, lubricating oil and control systems while using standard piping systems, expansion valves and installation practices.

Albrecht, R.H. (New York State Energy Research and Development Authority, Albany, NY (United States)); Borhanian, H.; Rafuse, L.J. (Aspen Systems Inc., Marlborough, MA (United States)); Matthews, T.J. (Hannaford Bros., Co., Scarborough, ME (United States))

1994-02-01T23:59:59.000Z

472

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

473

Table B36. Refrigeration Equipment, Number of Buildings and Floorspace, 1999  

U.S. Energy Information Administration (EIA) Indexed Site

6. Refrigeration Equipment, Number of Buildings and Floorspace, 1999" 6. Refrigeration Equipment, Number of Buildings and Floorspace, 1999" ,"Number of Buildings (thousand)",,,,,"Total Floorspace (million square feet)" ,"All Buildings","All Buildings with Refrigeration Equipment","Type of Equipment (more than one may apply)",,,"All Buildings","All Buildings with Refrigeration Equipment","Type of Equipment (more than one may apply)" ,,,"Walk-In","Open Cases or Cabinets","Closed Cases or Cabinets",,,"Walk-In","Open Cases or Cabinets","Closed Cases or Cabinets" "All Buildings ................",4657,950,658,255,719,67338,25652,19713,8808,19938 "Building Floorspace"

474

ISAC SC-LINAC PHASE-II HELIUM REFRIGERATOR COMMISSIONING AND FIRST OPERATIONAL EXPERIENCE AT TRIUMF  

SciTech Connect

ISAC Phase-II is an upgrade of the radioactive isotope superconducting linear accelerator, SC-linac, at TRIUMF. The Phase-I section of the accelerator, medium-beta, is operational and is cooled with a 600 W helium refrigerator, commissioned in March 2005. An identical refrigerator is being used with the Phase-II segment of the accelerator; which is now under construction. The second refrigerator has been commissioned and tested with the Phase-I section of the linac and is used for Phase-II linac development, including new SC-cavity performance tests. The commissioning of the Phase-II refrigeration system and recent operational experience is presented.

Sekachev, I.; Kishi, D.; Laxdal, R. E. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada)

2010-04-09T23:59:59.000Z

475

Some studies on industrial Refrigeration system integrated With encapsulated pcm in cool Thermal energy storage system;.  

E-Print Network (OSTI)

??The widespread use of refrigeration and air conditioning utilities newlineespecially in the developing countries has increased manifold during the last newlinedecade This additional load on… (more)

Cheralathan M

2014-01-01T23:59:59.000Z

476

Development and Testing of a Screw Compressor Supermarket Refrigeration System: Phase II, Final Report.  

SciTech Connect

A laboratory prototype screw compressor refrigeration system was designed, fabricated and tested under various evaporator and ambient conditions. The design is based on a Dunham-Bush vertical hermetic screw compressor and other standard refrigeration components. Results indicate that a screw compressor rack with vapor injection can increase the thermodynamic efficiency of low temperature refrigeration in supermarkets by 20 to 28% compared to multiple reciprocating compressor racks. The payback period of the screw compressor refrigeration system relative to multiple reciprocating compressor systems is 1.1 to 1.5 years and the net present value savings range from 15 to 22 thousand dollars.

Borhanian, H. Hamed; Toscano, William M.; Lee, Kang P.

1987-02-01T23:59:59.000Z

477

Options for reducing refrigerant emissions from supermarket systems. Final report, February-September 1994  

SciTech Connect

The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characterizes the design of typical supermarket refrigeration systems and focuses on why these types of systems have high rates of refrigerant emissions. Three case studies are provided of companies that have successfully implemented emission-reducing practices and technologies. The report discusses a variety of technical and procedural options that can be applied to existing systems and in new construction.

Troy, E.F.

1997-04-01T23:59:59.000Z

478

Refrigerator Efficiency in Ghana: Tailoring an appliance market transformation program design for Africa  

E-Print Network (OSTI)

World Business Information: Refrigerators, URL: http://www.gobi.co.uk/page42.htm International Energy Agency (2005) IEA Energy Statistics,

Ben Hagan, Essel; Van Buskirk, Robert; Ofosu-Ahenkorah, Alfred; McNeil, Michael A.

2006-01-01T23:59:59.000Z

479

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

480

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

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

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

Note: This page contains sample records for the topic "modeling variable refrigerant" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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481

E-Print Network 3.0 - authority refrigerator replacement Sample...  

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

Summary: generally replacing their old refrigerator with a larger capacity unit. Rising energy prices and heightened... -95d DEVELOPMENT OF A HIGH EFFICIENCY,...

482

Refrigerator/freezer directory: sorted by type and volume, based on 1979 standards  

SciTech Connect

This directory identifies refrigerators, freezers and combinations thereof, that have been certified as complying with the regulations that became effective on November 3, 1979.

Not Available

1980-02-29T23:59:59.000Z

483

New Development of Simulation Methods on Refrigeration and Air Conditioning Equipments  

Science Journals Connector (OSTI)

Development status of classical simulation technology and application status of artificial intelligence on refrigeration and air conditioning equipments were introduced. The new concept of intelligence simulat...

Cao Wensheng

2011-01-01T23:59:59.000Z

484

E-Print Network 3.0 - arti refrigerant database Sample Search...  

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

-- &i Supplementary Laboratory Testing William M. Toscano... ENERGY-EFFICIENT SUPERMARKET REFRIGERATION SYSTEMS VOLUME 2 SUPPLEMENTAL ... Source: Oak Ridge National Laboratory -...

485

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

E-Print Network (OSTI)

in significant energy and demand savings for refrigeratedbe modified to reduce energy demand during demand responsein refrigerated warehouse energy demand if they are not

Lekov, Alex

2009-01-01T23:59:59.000Z

486

Cryogenic system for ITER CS model coil  

SciTech Connect

A 5-kW/4.5-K helium refrigerator has been developed, which will be used for the test of ITER Central Solenoid Model Coil that is under fabrication by an international collaboration under the framework of the ITER Engineering Design Activity. Its acceptance test was recently finished and its specified refrigeration power of 5 kW with a surplus liquefaction rate of 114 1/h was demonstrated. A major feature of the refrigerator is that newly developed components, such as helium compressor and turbo-expander, are adopted in its simple refrigeration process in order that the results will be transferred to the ITER helium cryogenic system.

Kato, T.; Hamada, K.; Kawano, K.; Hiyama, T. [JAERI, Naka Fusion Research Establishment, Nada-machi, Nada-gun, Ibaraki-ken (Japan)] [and others

1996-12-31T23:59:59.000Z

487

Auto-Baecklund transformation and new exact solutions of the generalized variable-coefficients two-dimensional Korteweg-de Vries model  

SciTech Connect

Describing plasma physics, cluster physics, and geophysical fluid dynamics, a generalized variable-coefficient two-dimensional Korteweg-de Vries (GVCKdV) model is hereby under investigation. In this paper, an extended-variable-coefficient homogeneous balance method with symbolic computation is used to obtain an auto-Baecklund transformation, some rational solutions, and new soliton-type solutions for the GVCKdV model. The solutions of the well-known cylindrical Kadomtsev-Petviashvili equation can be recovered as special cases of the results obtained here.

Li Yezhou; Liu Jianguo [School of Science, Beijing University of Posts and Telecommunications, P.O. Box 91, Beijing 100876 (China)

2007-02-15T23:59:59.000Z

488

Refrigeration system with a compressor-pump unit and a liquid-injection desuperheating line  

DOE Patents (OSTI)

The refrigeration system includes a compressor-pump unit and/or a liquid-injection assembly. The refrigeration system is a vapor-compression refrigeration system that includes an expansion device, an evaporator, a compressor, a condenser, and a liquid pump between the condenser and the expansion device. The liquid pump improves efficiency of the refrigeration system by increasing the pressure of, thus subcooling, the liquid refrigerant delivered from the condenser to the expansion device. The liquid pump and the compressor are driven by a single driving device and, in this regard, are coupled to a single shaft of a driving device, such as a belt-drive, an engine, or an electric motor. While the driving device may be separately contained, in a preferred embodiment, the liquid pump, the compressor, and the driving device (i.e., an electric motor) are contained within a single sealable housing having pump and driving device cooling paths to subcool liquid refrigerant discharged from the liquid pump and to control the operating temperature of the driving device. In another aspect of the present invention, a liquid injection assembly is included in a refrigeration system to divert liquid refrigerant from the discharge of a liquid pressure amplification pump to a compressor discharge pathway within a compressor housing to desuperheat refrigerant vapor to the saturation point within the compressor housing. The liquid injection assembly includes a liquid injection pipe with a control valve to meter the volume of diverted liquid refrigerant. The liquid injection assembly may also include a feedback controller with a microprocessor responsive to a pressure sensor and a temperature sensor both positioned between the compressor to operate the control valve to maintain the refrigerant at or near saturation.

Gaul, Christopher J. (Thornton, CO)

2001-01-01T23:59:59.000Z

489

Greenhouse Gas Emissions for Refrigerant Choices in Room Air Conditioner Units  

Science Journals Connector (OSTI)

In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. ... De Kleine, R. D.; Keoleian, G. A.; Kelly, J. C.Optimal replacement of residential air conditioning equipment to minimize energy, greenhouse gas emissions, and consumer cost in the US Energy Policy 2011, 39, 3144– 3153 ... Most of the inventory data have been collected from Thailand, except for the upstream of fuel oil and fuel transmission, which have been computed from Greenhouse gases, Regulated Emissions, and Energy use in Transportation version 1.7 and Global Emission Model for Integrated Systems version 4.3. ...

Michael D. Galka; James M. Lownsbury; Paul Blowers

2012-11-08T23:59:59.000Z

490

Thermodynamic property evaluation and magnetic refrigeration cycle analysis for gadolinium gallium garnet  

SciTech Connect

Based on relevant material property data and previous model formulations, a magnetothermodynamic property map for gadolinium gallium garnet (Gd{sub 3}Ga{sub 5}O{sub 12}) was adapted for refrigeration cycle analysis in the temperature range 4-40 K and the magnetic field range 0-6 T. Employing methods similar to those previously developed for other materials and temperature ranges, assessments of limitations and relative performance were made for Carnot, ideal regenerative, and pseudo-constant field regenerative cycles. It was found that although Carnot cycle limitations on available temperature lift for gadolinium gallium garnet are not as severe as the limitations for materials previously examined, considerable improvement in cooling capacity and temperature lift combinations can be achieved by using regenerative cycles if serious loss mechanisms are avoided.

Murphy, R.W.

1994-12-01T23:59:59.000Z

491

Process design of helium refrigerators collaborated with the predesign of turbo expander  

Science Journals Connector (OSTI)

Turbo expanders are the most critical components in helium refrigerators. However since the performance of expanders is dependent on a number of operating parameters and the relations between them are quite complex usually only very simple modeling for expanders is applied during the process design with which the scale and performance of expanders cannot be rated. Hence the design parameters specified by process design may not match the current turbine technology. As a solution we employed a collaborated design method with which a predesign for turbo expanders is integrated into the process design. The tip wheel diameter the tip speed the rotational speed and the efficiency of turbo expander are preliminarily calculated. Evaluation of these parameters helps us to check if the process design is appropriate or need to be further improved.

2014-01-01T23:59:59.000Z

492

Adapted from FDA refrigerator and freezer guidelines: http://www.fda.gov/downloads/Food/ResourcesForYou/HealthEducators/UCM109315.pdf Have you ever wondered how long you should keep things in the refrigerator or freezer? If so, then the chart below can he  

E-Print Network (OSTI)

Adapted from FDA refrigerator and freezer guidelines: http://www.fda.gov/downloads/Food/ResourcesForYou/HealthEducators/UCM109315.pdf Have you ever wondered how long you should keep things in the refrigerator or freezer? If so to preserve quality. Refrigerator & Freezer Storage Chart Product Refrigerator Freezer Product Refrigerator

493

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, Zürich, Switzerland,Performance of ground source heat pump system in a near-zero

Hong, Tainzhen

2010-01-01T23:59:59.000Z

494

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

495

Variable gas spring for matching power output from FPSE to load of refrigerant compressor  

DOE Patents (OSTI)

The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand.

Chen, Gong (Athens, OH); Beale, William T. (Athens, OH)

1990-01-01T23:59:59.000Z