Sample records for modeling variable refrigerant

  1. A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard A. [Florida Solar Energy Center

    2013-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

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

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

    SciTech Connect (OSTI)

    Sharma, Chandan; Raustad, Richard

    2013-06-01T23:59:59.000Z

    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.

  4. HVAC's Variable Refrigerant Flow (VRF) Technology

    E-Print Network [OSTI]

    Jones, S.

    2012-01-01T23:59:59.000Z

    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... Moveable Ductless 5 VRF Technology Overview 6 What is VRF Technology? Variable Refrigerant Flow More Comfort, Less Energy Usage 8 INVERTER-driven Compressor Time R oo m T em pe ra tur e ? Enables capacity operation as low as 4% ? Sizing...

  5. Model Based Control Refrigeration Systems

    E-Print Network [OSTI]

    Model Based Control of Refrigeration Systems Ph.D. Thesis Lars Finn Sloth Larsen Central R & D University, Denmark. The work has been carried out at the Central R&D - Refrigeration and Air Conditioning The subject for this Ph.D. thesis is model based control of refrigeration systems. Model based control covers

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

    SciTech Connect (OSTI)

    Raustad, Richard; Nigusse, Bereket; Domitrovic, Ron

    2013-09-30T23:59:59.000Z

    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

  7. Fast Nonconvex Model Predictive Control for Commercial Refrigeration

    E-Print Network [OSTI]

    Fast Nonconvex Model Predictive Control for Commercial Refrigeration Tobias Gybel Hovgard , Lars F 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

  8. Microscopic model of a phononic refrigerator

    E-Print Network [OSTI]

    Liliana Arrachea; Eduardo Mucciolo; Claudio Chamon; Rodrigo Capaz

    2012-11-05T23:59:59.000Z

    We analyze a simple microscopic model to pump heat from a cold to a hot reservoir in a nanomechanical system. The model consists of a one-dimensional chain of masses and springs coupled to a back gate through which a time-dependent perturbation is applied. The action of the gate is to modulate the coupling of the masses to a substrate via additional springs that introduce a moving phononic barrier. We solve the problem numerically using non-equilibrium Green function techniques. For low driving frequencies and for sharp traveling barriers, we show that this microscopic model realizes a phonon refrigerator.

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

    E-Print Network [OSTI]

    Zhu, H.

    2006-01-01T23:59:59.000Z

    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...

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

    E-Print Network [OSTI]

    Zhu, H.

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-3 Impact of the Variable Refrigerant Volume Air Conditioning System on Building Energy Efficiency Huawei Zhu Zhejiang Urban and Rural Planning Design Institute... conditioning system has led to extensive criticism. 2. THE CHARACTERISTICS OF THE VARIABLE REFRIGERANT VOLUME AIR CONDITIONING SYSTEM AND ITS PRESENT APPLICATION ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-3 2...

  11. Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 Scroll compressor modelling for heat pumps using hydrocarbons as refrigerants Paul BYRNE prototype working with a scroll compressor was built and tested. A near-industrial prototype is today being regarding hydrocarbons as refrigerants, this article reviews scroll compressor modelling studies

  12. Energy Simulation of Integrated Multiple-Zone Variable Refrigerant Flow System

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    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

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Chapter 3: Refrigeration Process Control: Case Study Model 42 33.. RREEFFRRIIGGEERRAATTIIOONN-stage refrigeration system case study. It describes in detail the mathematical model developed, highlighting.1. PROCESS DESCRIPTION The cycle considered here is a two-stage side-load refrigeration unit with propylene

  15. DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT CHAMOUN MARWAN as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump of Refrigeration 35, 4 (2012) 1080-1091" DOI : 10.1016/j.ijrefrig.2011.12.007 #12;2 NOMENCLATURE A Cross sectional

  16. Mathematical Model of an Air-Filled Alpha Stirling Refrigerator Patrick McFarlane,1, a)

    E-Print Network [OSTI]

    Sen, Mihir

    Mathematical Model of an Air-Filled Alpha Stirling Refrigerator Patrick McFarlane,1, a) Fabio for an alpha Stirling refrigerator with air as the working fluid and will be useful in optimizing Stirling refrigeration systems. a) Electronic mail: pmcfarla@nd.edu b) Electronic mail: Fabio.Semperlotti.1

  17. Development of Versatile Compressor Modeling using Approximation Techniques for Alternative Refrigerants Evaluation

    SciTech Connect (OSTI)

    Abdelaziz, Omar [ORNL] [ORNL; Shrestha, Som S [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Refrigerants are the life-blood of vapor compression systems that are widely used in Heating, Ventilation, Air-Conditioning, and Refrigeration (HVAC&R) applications. The HVAC&R community is currently transitioning from main-stream refrigerants that have high Global Warming Potential (GWP) to alternative lower-GWP refrigerants. During this transition, it is important to account for the life cycle climate performance of alternative refrigerants since their performance will be different than that of higher-GWP refrigerants. This requires the evaluation of the system performance with the new refrigerants. Unfortunately, it is extremely difficult to predict the realistic performance of new alternative refrigerants without experimental validation. One of the main challenges in this regard is modeling the compressor performance with high fidelity due to the complex interaction of operating parameters, geometry, boundary conditions, and fluid properties. High fidelity compressor models are computationally expensive and require significant pre-processing to evaluate the performance of alternative refrigerants. This paper presents a new approach to modeling compressor performance when alternative refrigerants are used. The new modeling concept relies on using existing compressor performance to create an approximate model that captures the dependence of compressor performance on key operating parameters and fluid properties. The model can be built using a myriad of approximation techniques. This paper focuses on Kriging-based techniques to develop higher fidelity approximate compressor models. Baseline and at least one alternative refrigerant performance data are used to build the model. The model accuracy was evaluated by comparing the model results with compressor performance data using other refrigerants. Preliminary results show that the approximate model can predict the compressor mass flow rate and power consumption within 5%.

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

    SciTech Connect (OSTI)

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01T23:59:59.000Z

    With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 Module Development and Simulation of the Variable Refrigerant Flow Air Conditioning System under Cooling Conditions in Energyplus Yanping Zhou Jingyi..., especially for those who ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-2 show some interest about high-efficiency systems like VRF, it becomes of interest to compare the VRF to other systems and evaluate VRF?s performance...

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

    E-Print Network [OSTI]

    Weston, Ken

    1 Sample Self-Heating in the Portable Dilution Refrigerator Figure 1. Self-heating of a model ~ 6 pW, self heating begins to occur. The most dramatic result of this test was that a temperature

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

    E-Print Network [OSTI]

    Farzad, Mohsen

    1990-01-01T23:59:59.000Z

    a small refrigerant charge. A new heat exchanger model based on tube-by-tube simulation was developed and integrated into the ORNL heat pump model. The model was capable of simulating the steady state response of a vapor compression air-to-air heat...

  2. Physical control oriented model of large scale refrigerators to synthesize advanced control schemes. Design, validation, and first control results

    SciTech Connect (OSTI)

    Bonne, François; Bonnay, Patrick [INAC, SBT, UMR-E 9004 CEA/UJF-Grenoble, 17 rue des Martyrs, 38054 Grenoble (France); Alamir, Mazen [Gipsa-Lab, Control Systems Department, CNRS-University of Grenoble, 11, rue des Mathématiques, BP 46, 38402 Saint Martin d'Hères (France)

    2014-01-29T23:59:59.000Z

    In this paper, a physical method to obtain control-oriented dynamical models of large scale cryogenic refrigerators is proposed, in order to synthesize model-based advanced control schemes. These schemes aim to replace classical user experience designed approaches usually based on many independent PI controllers. This is particularly useful in the case where cryoplants are submitted to large pulsed thermal loads, expected to take place in the cryogenic cooling systems of future fusion reactors such as the International Thermonuclear Experimental Reactor (ITER) or the Japan Torus-60 Super Advanced Fusion Experiment (JT-60SA). Advanced control schemes lead to a better perturbation immunity and rejection, to offer a safer utilization of cryoplants. The paper gives details on how basic components used in the field of large scale helium refrigeration (especially those present on the 400W @1.8K helium test facility at CEA-Grenoble) are modeled and assembled to obtain the complete dynamic description of controllable subsystems of the refrigerator (controllable subsystems are namely the Joule-Thompson Cycle, the Brayton Cycle, the Liquid Nitrogen Precooling Unit and the Warm Compression Station). The complete 400W @1.8K (in the 400W @4.4K configuration) helium test facility model is then validated against experimental data and the optimal control of both the Joule-Thompson valve and the turbine valve is proposed, to stabilize the plant under highly variable thermals loads. This work is partially supported through the European Fusion Development Agreement (EFDA) Goal Oriented Training Program, task agreement WP10-GOT-GIRO.

  3. Multiphysics modeling of a micro-scale Stirling refrigeration system Dongzhi Guo a

    E-Print Network [OSTI]

    McGaughey, Alan

    Multiphysics modeling of a micro-scale Stirling refrigeration system Dongzhi Guo a , Alan J.H. Mc Accepted 2 July 2013 Available online Keywords: Stirling microcooler Regenerator Coefficient of performance of arrays of silicon MEMS cooling elements that operate on the Stirling cycle has been designed

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01T23:59:59.000Z

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

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

    E-Print Network [OSTI]

    -refrigerator integrated onto a chip. The model takes into account of the Peltier cooling and heating, Joule heating-refrigerator, Peltier effect, Seebeck coefficient, and finite difference method (FDM) 1. Introduction The state and Peltier

  6. Theoretical Modelling of Magnetic Refrigeration Materials A PhD studentship is available in the Warwick Theory Group on a theoretical/computational PhD project

    E-Print Network [OSTI]

    Low, Robert

    Theoretical Modelling of Magnetic Refrigeration Materials A PhD studentship is available in the Warwick Theory Group on a theoretical/computational PhD project on the modelling of magnetic refrigeration or air, or for very low temperatures, helium. Therefore, magnetic refrigeration is environmentally

  7. Design of a single orifice pulse tube refrigerator through the development of a first-order model

    E-Print Network [OSTI]

    Schor, Alisha R. (Alisha Robin)

    2007-01-01T23:59:59.000Z

    A first order model for the behavior of a linear orifice pulse tube refrigerator (OPTR) was developed as a design tool for construction of actual OPTRs. The model predicts cooling power as well as the pressure/volume ...

  8. New energy test procedures for refrigerators and other appliances

    SciTech Connect (OSTI)

    Meier, Alan; Ernebrant, Stefan; Kawamoto, Kaoru; Wihlborg, Mats

    1999-04-01T23:59:59.000Z

    Many innovations in refrigerator design rely on microprocessors, sensors, and algorithms to control automatic defrost, variable speed,and other features. Even though these features strongly influence energy consumption, the major energy test procedures presently test only a refrigerator's mechanical efficiency and ignore the ''software'' aspects. We describe a new test procedure where both ''hardware'' and ''software'' tests are fed into a dynamic simulation model. A wide range of conditions can be tested and simulated. This approach promotes international harmonization because the simulation model can also be programmed to estimate energy use for the ISO, DOE, or JIS test. The approach outlined for refrigerators can also be applied to other appliances.

  9. Exergy analysis of magnetic refrigeration

    E-Print Network [OSTI]

    Lucia, Umberto

    2010-01-01T23:59:59.000Z

    One of the main challenges of the industry today is to face its impact on global warming considering that the greenhouse effect problem is not be solved completely yet. Magnetic refrigeration represents an environment-safe refrigeration technology. The magnetic refrigeration is analysed using the second law analysis and introducing exergy in order to obtain a model for engineering application.

  10. Numerical Simulation of PulseTube Refrigerators: 1D model I.A. Lyulina 1 , R.M.M. Mattheij 1 , A.S. Tijsseling 1 , A.T.A.M. de Waele 2

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    Numerical Simulation of Pulse­Tube Refrigerators: 1D model I.A. Lyulina 1 , R.M.M. Mattheij 1 , A of a pulse­tube refrigerator. Conservation equations describing compressible gas flow in the tube are solved, calculate the average enthalpy flow and estimate the refrigeration power. Keywords: pulse­tube refrigerator

  11. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G.W.

    1993-01-01T23:59:59.000Z

    Malone refrigeration is the use of a liquid near its critical points without evaporations as working fluid in a regenerative or recuperative refrigeration cycle such as the Stirling and Brayton cycles. It's potential advantages include compactness, efficiency, an environmentally benign working fluid, and reasonable cost. One Malone refrigerator has been built and studied; two more are under construction. Malone refrigeration is such a new, relatively unexplored technology that the potential for inventions leading to improvements in efficiency and simplicity is very high.

  12. Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration

    E-Print Network [OSTI]

    Zevenhoven, Ron

    RefrigerationRefrigerationRefrigeration coursecourse # 424503.0# 424503.0 v.v. 20122012 4. Refrigeration process comparison;f g p p process equipment needs, reliability, ease of operation cture:http://1 6.11.2012 Åbo Akademi Univ - Thermal and Flow open screw Va Typical equipment and compressor type ranges (source: S90) -80 6.11.2012 Åbo Akademi Univ

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

    E-Print Network [OSTI]

    Farzad, Mohsen

    An experimental and analytical study concerned with the off-design refrigerant charging of air conditioners is presented. A series of experiments were conducted to characterize the effects of refrigerant charge and type of expansion device...

  14. A Prediction Model for Adiabatic and Diabatic Capillary Tubes with Alternative Refrigerants 

    E-Print Network [OSTI]

    Zhang, Yupeng

    2014-12-05T23:59:59.000Z

    The capillary tube is a very common throttling device located between the condenser and evaporator in a refrigeration system. In some refrigerant systems, a section of the capillary tube is connected to a section of the ...

  15. Supplemental Simulation Case Studies of Dynamic Evaporator Modeling Paradigms with Variable Fluid Phases 

    E-Print Network [OSTI]

    Rodriguez, E.; Rasmussen, B.

    2015-01-01T23:59:59.000Z

    1Supplemental Simulation Case Studies of Dynamic Evaporator Modeling Paradigms with Variable Fluid Phases Erik Rodriguez1, Bryan Rasmussen2 The purpose of this document is to present a multitude of case studies comparing evaporator modeling... which uses two-phase region density to trigger mass conservative switching. Nine case studies are performed through a combination of three different refrigerants, three different physical system parameters, and three different operating conditions...

  16. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G W

    1992-01-01T23:59:59.000Z

    Malone refrigeration is the use of a liquid near its critical point, without evaporation, as working fluid in a refrigeration cycle such as the Stirling cycle. We discuss relevant properties of appropriate liquids, and describe two Malone refrigerators. The first completed several years ago, established the basic principles of use of liquids in such cycles. The second, now under construction, is a linear, free-piston machine.

  17. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G.W.

    1993-06-01T23:59:59.000Z

    Malone refrigeration is the use of a liquid near its critical points without evaporations as working fluid in a regenerative or recuperative refrigeration cycle such as the Stirling and Brayton cycles. It`s potential advantages include compactness, efficiency, an environmentally benign working fluid, and reasonable cost. One Malone refrigerator has been built and studied; two more are under construction. Malone refrigeration is such a new, relatively unexplored technology that the potential for inventions leading to improvements in efficiency and simplicity is very high.

  18. Variable Refrigerant Flow HVAC

    E-Print Network [OSTI]

    Jones, S.

    2013-01-01T23:59:59.000Z

    heat pump utilizing VFD Inverter Compressors and LEV’s Unlike conventional commercial and residential HVAC systems in the USA The predominate method of cooling and heating in the world ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency... Conference, San Antonio, Texas Dec. 16-18 Heat Pump operation at lower ambient conditions -13 -4 5 17 23 32 41 470 0.2 0.4 0.6 0.8 1 1.2 Residential Heating Capacity at Low Temperatures MUZ-FE18NA MUZ-FE09NA MUZ-FE12NA Unitary Outdoor Temperature (F...

  19. Variable Refrigerant Flow Systems

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

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

  20. Variable Refrigerant Flow Systems

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1 - USAF Wind Power Program Latitude: N.Data

  1. Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration

    E-Print Network [OSTI]

    Zevenhoven, Ron

    on a vapour-compression cycle) /heat_pump.g Heat pumps make use of low- temperature (waste) heat, replacing indoor space, or 5) waste heat from a process or device http://www.fos device COPHP ~ TH / (THRefrigerationRefrigerationRefrigeration coursecourse # 424503.0# 424503.0 v.v. 20122012 8. Heat pumps, heat pipes, cold thermal energy storage Ron

  2. Form Date 4/4/01 Refrigerant Service Order Form

    E-Print Network [OSTI]

    Russell, Lynn

    Form 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 Minor Maintenance Recovery Vacuum: __________Inches Dispose of Unit Refrigerant Conversion Major

  3. Model for corrosion of carbon steel in lithium bromide absorption refrigeration systems

    SciTech Connect (OSTI)

    Anderko, A.; Young, R.D.

    2000-05-01T23:59:59.000Z

    A comprehensive model has been developed for the computation of corrosion rates of carbon steels in the presence of lithium bromide (LiBr)-based brines that are used as working fluids for absorption refrigeration cycles. The model combines a thermophysical module that provides realistic speciation of aqueous systems with an electrochemical module for partial cathodic and anodic processes on the metal surface. The electrochemical module includes the absorption of halides, which strongly influences the corrosion process. Also, the model takes into account the formation of passive films and their interactions with solution species. The model has been verified by comparing calculated corrosion rates with laboratory data for carbon steels in LiBr solutions. Good agreement between calculated and experimental corrosion rates has been obtained. In particular, the model is capable of reproducing effects of pH-adjusting components and selected inhibitors on the rates of general corrosion. The model has been incorporated into a program that makes it possible to analyze effects of various conditions such as temperature, pressure, solution composition, or flow velocity on corrosion rates.

  4. Cospolich Refrigerator: Order (2013-CE-5314)

    Broader source: Energy.gov [DOE]

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

  5. Refrigerator Manufacturers: Order (2013-CE-5341)

    Broader source: Energy.gov [DOE]

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

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

    E-Print Network [OSTI]

    Gupta, Ankush 1986-

    2012-09-27T23:59:59.000Z

    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...

  7. Optimal refrigerator

    E-Print Network [OSTI]

    Armen E. Allahverdyan; Karen Hovhannisyan; Guenter Mahler

    2010-07-25T23:59:59.000Z

    We study a refrigerator model which consists of two $n$-level systems interacting via a pulsed external field. Each system couples to its own thermal bath at temperatures $T_h$ and $T_c$, respectively ($\\theta\\equiv T_c/T_hrefrigerator functions in two steps: thermally isolated interaction between the systems driven by the external field and isothermal relaxation back to equilibrium. There is a complementarity between the power of heat transfer from the cold bath and the efficiency: the latter nullifies when the former is maximized and {\\it vice versa}. A reasonable compromise is achieved by optimizing the product of the heat-power and efficiency over the Hamiltonian of the two system. The efficiency is then found to be bounded from below by $\\zeta_{\\rm CA}=\\frac{1}{\\sqrt{1-\\theta}}-1$ (an analogue of the Curzon-Ahlborn efficiency), besides being bound from above by the Carnot efficiency $\\zeta_{\\rm C} = \\frac{1}{1-\\theta}-1$. The lower bound is reached in the equilibrium limit $\\theta\\to 1$. The Carnot bound is reached (for a finite power and a finite amount of heat transferred per cycle) for $\\ln n\\gg 1$. If the above maximization is constrained by assuming homogeneous energy spectra for both systems, the efficiency is bounded from above by $\\zeta_{\\rm CA}$ and converges to it for $n\\gg 1$.

  8. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

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

    1992-12-22T23:59:59.000Z

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

  9. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

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

    1992-01-01T23:59:59.000Z

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

  10. 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]

    Wisconsin at Madison, University of

    This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed of an Active Magnetic Regenerator Refrigerator 1. Governing Equations Figure 1 shows a schematic of an active in MATLAB. The model uses cycle inputs such as the fluid mass flow and magnetic field profiles, fluid

  11. Kylteknik ("KYL")Kylteknik ("KYL") RefrigerationRefrigerationRefrigerationRefrigeration

    E-Print Network [OSTI]

    Zevenhoven, Ron

    - compression cycle Sources for "cheap heat" could be waste heat from power generation or steamp g plants processes: i l ffi iexpensive, spacy, low efficiency, requires large cooling towers for waste heat, a refrigeration cycle can be driven by heat (preferably 100-200°C) The replaces the compressor in a vapour

  12. Comparison of two models of a Double Inlet Miniature Pulse Tube Refrigerator : Part B Electrical Analogy

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Inlet Pulse Tube Refrigerator is investigated by means of an analogy with an electric circuit) and experiments. The basic formulation of equivalent electronic components is discussed and a few improvements to avoid mechanical vibrations and magnetic fields. Therefore, a third capillary is used to link

  13. Fluorescent refrigeration

    DOE Patents [OSTI]

    Epstein, Richard I. (Santa Fe, NM); Edwards, Bradley C. (Los Alamos, NM); Buchwald, Melvin I. (Santa Fe, NM); Gosnell, Timothy R. (Santa Fe, NM)

    1995-01-01T23:59:59.000Z

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

  14. Refrigerant directly cooled capacitors

    DOE Patents [OSTI]

    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

    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.

  15. Tabletop thermoacoustic refrigerator for demonstrations Daniel A. Russell and Pontus Weibulla)

    E-Print Network [OSTI]

    Russell, Daniel A.

    Tabletop thermoacoustic refrigerator for demonstrations Daniel A. Russell and Pontus Weibulla; accepted 22 April 2002 An inexpensive less than $25 tabletop thermoacoustic refrigerator for demonstration in the literature, this demonstration model effectively illustrates the behavior of a thermoacoustic refrigerator

  16. Fluorescent refrigeration

    DOE Patents [OSTI]

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

    1995-09-05T23:59:59.000Z

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

  17. ARTI refrigerant database

    SciTech Connect (OSTI)

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

    1999-01-01T23:59:59.000Z

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

  18. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1996-11-15T23:59:59.000Z

    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.

  19. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1996-07-01T23:59:59.000Z

    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.

  20. Pearle's Hidden-Variable Model Revisited

    E-Print Network [OSTI]

    Richard D. Gill

    2015-05-19T23:59:59.000Z

    Pearle (1970) gave an example of a local hidden variables model which exactly reproduced the singlet correlations of quantum theory, through the device of data-rejection: particles can fail to be detected in a way which depends on the hidden variables carried by the particles and on the measurement settings. If the experimenter computes correlations between measurement outcomes of particle pairs for which both particles are detected, he is actually looking at a subsample of particle pairs, determined by interaction involving both measurement settings and the hidden variables carried in the particles. We correct a mistake in Pearle's formulas (a normalization error) and more importantly show that the model is more simple than first appears. We illustrate with visualisations of the model and with a small simulation experiment, with code in the statistical programming language R included in the paper. Open problems are discussed.

  1. Control method for mixed refrigerant based natural gas liquefier

    DOE Patents [OSTI]

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

    2003-01-01T23:59:59.000Z

    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.

  2. Duracold Refrigeration Manufacturing: Order (2013-CE-5342)

    Broader source: Energy.gov [DOE]

    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.

  3. Commercial Refrigerator Door: Order (2013-CE-5351)

    Broader source: Energy.gov [DOE]

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

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

    Broader source: Energy.gov [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.

  5. Refrigeration system having standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (Glen Allen, VA)

    1992-01-01T23:59:59.000Z

    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.

  6. ARTI Refrigerant Database

    SciTech Connect (OSTI)

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

    1994-05-27T23:59:59.000Z

    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.

  7. Plant Site Refrigeration Upgrade

    E-Print Network [OSTI]

    Zdrojewski, R.; Healy, M.; Ramsey, J.

    Bayer Corporation operates a multi-division manufacturing facility in Bushy Park, South Carolina. Low temperature refrigeration (-4°F) is required by many of the chemical manufacturing areas and is provided by a Plant Site Refrigeration System...

  8. Save with Hybrid Refrigeration

    E-Print Network [OSTI]

    Chung, C. W.

    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...

  9. Literature survey of heat transfer enhancement techniques in refrigeration applications

    SciTech Connect (OSTI)

    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

    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.

  10. ARTI refrigerant database

    SciTech Connect (OSTI)

    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

    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.

  11. Multiscale modeling of spatially variable water and energy balance processes

    E-Print Network [OSTI]

    Famiglietti, J. S; Wood, E. F

    1994-01-01T23:59:59.000Z

    MULTISCALE WATER AND ENERGY BALANCE MODELING Wood, E. F. ,spatially variable water and energy balance processes J. S.modeling. Water and energy balance models are developed at

  12. The Quantum Absorption Refrigerator

    E-Print Network [OSTI]

    Amikam Levy; Ronnie Kosloff

    2011-11-09T23:59:59.000Z

    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.

  13. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

    Vobach, A.R.

    1987-11-24T23:59:59.000Z

    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.

  14. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

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

  15. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

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

  16. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

    Vobach, A.R.

    1987-06-23T23:59:59.000Z

    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.

  17. Bayesian variable selection in clustering via dirichlet process mixture models

    E-Print Network [OSTI]

    Kim, Sinae

    2007-09-17T23:59:59.000Z

    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...

  18. Small Commercial Refrigeration Incentive

    Broader source: Energy.gov [DOE]

    Efficiency Vermont offers financial incentives to cover the incremental costs of energy efficient refrigeration for commercial, industrial, agricultural and institutional buildings. To receive the...

  19. ARTI refrigerant database

    SciTech Connect (OSTI)

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

    1998-08-01T23:59:59.000Z

    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 manufactures 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 many refrigerants including propane, ammonia, water, carbon dioxide, propylene, ethers, and others as well as azeotropic and zeotropic blends of these fluids. 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.

  20. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1997-02-01T23:59:59.000Z

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

  1. Asset Management Equipment Disposal Form -Refrigerant Recovery

    E-Print Network [OSTI]

    Sin, Peter

    Asset Management Equipment Disposal Form - Refrigerant Recovery Safe Disposal Requirements Under refrigeration, cold storage warehouse refrigeration, chillers, and industrial process refrigeration) has to have the refrigerant recovered in accordance with EPA's requirements for servicing. However, equipment that typically

  2. A Prediction Model for Adiabatic and Diabatic Capillary Tubes with Alternative Refrigerants

    E-Print Network [OSTI]

    Zhang, Yupeng

    2014-12-05T23:59:59.000Z

    line) that exits the evaporator, which creates the so called capillary tube/suction line heat exchanger. Models to predict the mass flow in both adiabatic capillary tubes and capillary tube/suction line heat exchangers are developed in this thesis...

  3. COLD STORAGE DESIGN REFRIGERATION EQUIPMENT

    E-Print Network [OSTI]

    COLD STORAGE DESIGN AND REFRIGERATION EQUIPMENT REFRIGERATION OF FISH - PART 1 \\ "..\\- ,,, T I Fishery Leaflet 427 Washington 25, D. C. June 1956 REFRIGERATION OF FISH - PART em; COlD STORAGE DESIGN AND REFRIGERATION EQUIPMENT By Charles Butler (Section 1), Joseph W. Slavin (Sections 1, 2, and 3), Max Patashnik

  4. 2014-12-22 Issuance: Alternative Efficiency Determination Methods, Basic Model Definition, and Compliance for Commercial HVAC, Refrigeration, and Water Heating Equipment; Final Rule

    Broader source: Energy.gov [DOE]

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

  5. Stirling-cycle refrigerator

    SciTech Connect (OSTI)

    Nakamura, K.

    1985-06-11T23:59:59.000Z

    A Stirling-cycle refrigerator comprises a plurality of Stirling-cycle refrigerator units each having a displacer defining an expansion chamber, a piston defining a compression chamber, and a circuit including a heater and a cooler and interconnecting the expansion chamber and the compression chamber, and a heat exchanger shared by the circuits and disposed between the coolers and the heaters for effecting heat exchange between working gases in the circuits. The heat exchanger may comprise a countercurrent heat exchanger, and the Stirling-cycle refrigerator units are operated in cycles which are 180/sup 0/ out of phase with each other.

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

    Energy Savers [EERE]

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

  7. Refrigerant Compliance Updated: July 12, 2012

    E-Print Network [OSTI]

    Holland, Jeffrey

    Refrigerant Compliance Policy Updated: July 12, 2012 #12;TABLE OF CONTENTS The official version ........................................................................................................ 3 A. Refrigerant Compliance Manager (RCM).................................................................. 3 B. Refrigerant Inventory Coordinator (RIC

  8. Development of Low Global Warming Potential Refrigerant Solutions for Commercial Refrigeration Systems using a Life Cycle Climate Performance Design Tool

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, direct emissions related to refrigerant leakage and indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications to provide lower Global Warming Potential (GWP) refrigerant solutions with improved LCCP compared to baseline systems. The LCCP design tool accounts for system performance, ambient temperature, and system load; system performance is evaluated using a validated vapor compression system simulation tool while ambient temperature and system load are devised from a widely used building energy modeling tool (EnergyPlus). The LCCP design tool also accounts for the change in hourly electricity emission rate to yield an accurate prediction of indirect emissions. The analysis shows that conventional commercial refrigeration system life cycle emissions are largely due to direct emissions associated with refrigerant leaks and that system efficiency plays a smaller role in the LCCP. However, as a transition occurs to low GWP refrigerants, the indirect emissions become more relevant. Low GWP refrigerants may not be suitable for drop-in replacements in conventional commercial refrigeration systems; however some mixtures may be introduced as transitional drop-in replacements. These transitional refrigerants have a significantly lower GWP than baseline refrigerants and as such, improved LCCP. The paper concludes with a brief discussion on the tradeoffs between refrigerant GWP, efficiency and capacity.

  9. Save with Hybrid Refrigeration 

    E-Print Network [OSTI]

    Chung, C. W.

    1985-01-01T23:59:59.000Z

    ) unit, is presented in this article. This paper will briefly describe process configuration, advantages and utility consumption, equipment cost and direct field cost comparisons of such a hybrid refrigeration unit over its counterpart, a cascading MCR...

  10. Thermoacoustic engines and refrigerators

    SciTech Connect (OSTI)

    Swift, G.

    1996-12-31T23:59:59.000Z

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

  11. Refrigerants in Transition 

    E-Print Network [OSTI]

    Stouppe, D. E.

    1991-01-01T23:59:59.000Z

    great that a meeting was held in 1987 to address the problem. A treaty was the result of this meeting. Legislation on the production and use of these chemicals followed. Industry has responded by testing replacement refrigerants. This paper describes...

  12. Helium dilution refrigeration

    E-Print Network [OSTI]

    McKee, Thomas Raymond

    1968-01-01T23:59:59.000Z

    13 13 Methods of dilution and recirculation. 14 3. L'. Successful refrigeration. . . , . 15 CONTINUOUS DILUTION CYCLE, . ~ , ~ ~ 17 0. 1. Important components. 4. 2. 4. 3. Add. ition of He to the concentrated phase Cooling, and removal of' 3... the dilution was to occur by the diffusion down a tube containing a concentration gradient and. the second by diffusion of the solvent thru a semipermeable membrane into the concentrated mixture. Two methods of refrigeration were thoroughly discussed...

  13. Refrigerants in Transition

    E-Print Network [OSTI]

    Stouppe, D. E.

    .E. Senior Engineer The Hartford Steam Boiler Inspection and Insurance Company Hartford,. Connecticut ABSTRACT The massive growth of air conditioning and refrigeration has been a direct result of the development of a class of chemicals called fluorocarbons..., Gordon, "Forty Years Research on Atmospheric Ozone at Oxford: A !Iistory," Applied Optics, March t968, pp. 387-405. 4. Downing, R., "Development of Chloro fluorocarbon Refrigerants," CFCs: Time of Transition, ASHRAE Publication, Atlanta, GA, 1989...

  14. NBSIFI 86-3373 Impact of Refrigerant Property

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    of performance prediction to refrigerant properties for a residential, split heat pump operating in the cooling mode. The NBS steady-state heat pump model, HPSIM, was used in this study. The individual influence and refrigerant mass flow rate are also given in the report. iii #12;Discrepancy between heat pump laboratory test

  15. A Variable Cell Model for Simulating Gas Condensate Reservoir Performance

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    maturation profiles, which ie exhibitpd when gas pressure. Between this region near tha wellbore, SPE-~~~ SPE 21428 A Variable Cell Model for Simulating Gas Condensate Reservoir Performance A of depletion performance of gas condensate reservoirs report the existence of a A variable cell model

  16. ARTI Refrigerant Database

    SciTech Connect (OSTI)

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

    1993-04-30T23:59:59.000Z

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

  17. Optimal performance of endoreversible quantum refrigerators

    E-Print Network [OSTI]

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

    2014-11-24T23:59:59.000Z

    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.

  18. Waste Heat Recovery from Refrigeration

    E-Print Network [OSTI]

    Jackson, H. Z.

    1982-01-01T23:59:59.000Z

    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...

  19. IMPROVING THE ENERGY EFFECTIVENESS OF DOMESTIC REFRIGERATORS BY THE APPLICATION OF REFRIGERANT MIXTURES*

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;IMPROVING THE ENERGY EFFECTIVENESS OF DOMESTIC REFRIGERATORS BY THE APPLICATION OF REFRIGERANT.S. and foreign literature on the use of a mixture of refrigerants rather than a single one in a refrigeration-evaporator refrigerator typical of domestic refrigerators showed an energy savings of 12 percent. By acceptance

  20. Refrigeration monitor and alarm system

    SciTech Connect (OSTI)

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

    1986-09-23T23:59:59.000Z

    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.

  1. Magnetic refrigeration for spacecraft systems

    SciTech Connect (OSTI)

    Barclay, J.A.

    1981-01-01T23:59:59.000Z

    Magnetic refrigerators, i.e., those that use the magnetocaloric effect of a magnetic working material in a thermodynamic cycle, offer potentially reliable, and efficient refrigeration over a variety of temperature ranges and cooling powers. A descriptive analysis of magnetic refrigeration systems is performed with particular emphasis on more efficient infrared detector cooling. Three types of magnetic refrigerator designs are introduced to illustrate some of the possibilities.

  2. Ames Lab 101: Magnetic Refrigeration

    ScienceCinema (OSTI)

    Pecharsky, Vitalij

    2013-03-01T23:59:59.000Z

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  3. Ames Lab 101: Magnetic Refrigeration

    SciTech Connect (OSTI)

    Pecharsky, Vitalij

    2011-01-01T23:59:59.000Z

    Vitalij Pecharsky, distinguished professor of materials science and engineering, discusses his research in magnetic refrigeration at Ames Lab.

  4. ARTI Refrigerant Database

    SciTech Connect (OSTI)

    Calm, J.M.

    1992-11-09T23:59:59.000Z

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

  5. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-05-26T23:59:59.000Z

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

  6. Model Predictive Control of Variable Density Multiphase Flows Governed by

    E-Print Network [OSTI]

    Hinze, Michael

    of model predictive control (MPC) consists in steering or keeping the state of a dynamical systemModel Predictive Control of Variable Density Multiphase Flows Governed by Diffuse Interface Models appearing in the model predictive control strategy. The resulting control concept is known as instantaneous

  7. A model for variable thickness superconducting thin lms

    E-Print Network [OSTI]

    Chapman, Jon

    A model for variable thickness superconducting thin #12;lms S. J. Chapman #3; Mathematical for Applied Mathematics Virginia Tech Blacksburg VA 24061-0531, USA Abstract A model for superconductivity. When the #12;lm is of uniform thickness the model is identical to a model for superconducting cylinders

  8. Comparison of Several Eco-Friendly Refrigeration Technologies

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    In this paper, the operation principles, thermodynamics characteristics, and technical practicability were compared between thermoelectric refrigeration, magnetic refrigeration and adsorption refrigeration. The TE refrigeration is the most well...

  9. Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

    SciTech Connect (OSTI)

    Bansal, Pradeep [ORNL] [ORNL; Shen, Bo [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    This paper presents technical assessment of environmentally friendly refrigerants for window air conditioners that currently use refrigerant R410A for residential and commercial applications. The alternative refrigerants that are studied for its replacement include R32, R600a, R290, R1234yf, R1234ze and a mixture of R32 (90% molar concentration) and R125 (10% molar concentration). Baseline experiments were performed on a window unit charged with R410A. The ORNL Heat Pump Design Model was calibrated with the baseline data and was used to assess the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners.

  10. Cash for Clunkers Refrigerator Reimbursement Program To receive a financial incentive for replacing an OSU-owned old, inefficient, in-use and food-only

    E-Print Network [OSTI]

    Escher, Christine

    Cash for Clunkers Refrigerator Reimbursement Program To receive a financial incentive for replacing an OSU-owned old, inefficient, in-use and food-only refrigerator, please follow the steps below 1) Email (building and room #) of existing refrigerator c. Make and model # of existing refrigerator d. Make

  11. Cash for Clunkers Refrigerator Retirement Program To receive a financial incentive for retiring an OSU-owned old, inefficient, in-use and food-only

    E-Print Network [OSTI]

    Escher, Christine

    Cash for Clunkers Refrigerator Retirement Program To receive a financial incentive for retiring an OSU-owned old, inefficient, in-use and food-only refrigerator, please follow the steps below 1) Email (building and room #) of existing refrigerator c. Make and model # of refrigerator 2) Within 3 business days

  12. China Refrigerator Information Label

    E-Print Network [OSTI]

    LBNL-246E China Refrigerator Information Label: Specification Development and Potential Impact Jianhong Cheng China National Institute of Standardization Tomoyuki Sakamoto The Institute of Energy by the United States Gov- ernment. While this document is believed to contain correct information, neither

  13. Studies of climate variability in a simple coupled model

    E-Print Network [OSTI]

    Abiven, Claude

    2007-01-01T23:59:59.000Z

    The mechanisms of variability of a coupled atmosphere-ocean model are investigated through the study of two coupled configurations: an aquaplanet in which gyres are absent, and an aquaplanet in which a ridge extending from ...

  14. The smallest refrigerators can reach maximal efficiency

    E-Print Network [OSTI]

    Paul Skrzypczyk; Nicolas Brunner; Noah Linden; Sandu Popescu

    2011-12-02T23:59:59.000Z

    We investigate whether size imposes a fundamental constraint on the efficiency of small thermal machines. We analyse in detail a model of a small self-contained refrigerator consisting of three qubits. We show analytically that this system can reach the Carnot efficiency, thus demonstrating that there exists no complementarity between size and efficiency.

  15. Capturing Variability in Business Process Models: The Provop Approach

    E-Print Network [OSTI]

    Ulm, Universität

    Capturing Variability in Business Process Models: The Provop Approach Alena Hallerbach1 , Thomas be transferred to cross-organizational business processes as well [4]. A business process model captures models there exists a multitude of tools like ARIS Business Architect [5], ADONIS [6], and Web

  16. Nonlinear Latent Variable Models for Video Sequences

    E-Print Network [OSTI]

    rahimi, ali

    2005-06-06T23:59:59.000Z

    Many high-dimensional time-varying signals can be modeled as a sequence of noisy nonlinear observations of a low-dimensional dynamical process. Given high-dimensional observations and a distribution describing the ...

  17. BNL Refrigerant Overview Presentation to the

    E-Print Network [OSTI]

    Homes, Christopher C.

    BNL Refrigerant Overview Presentation to the BER and CAC Ed Murphy, PE Chief Engineer / Manager is a heating process. Refrigeration is an engineered "cycle" where the refrigerant is made to evaporate) to the cycle. Refrigerants are the "working fluids" in refrigeration, air conditioning and heat pumping systems

  18. Optimal Sequencing of Central Refrigeration Equipment in an Industrial Plant

    E-Print Network [OSTI]

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

    1986-01-01T23:59:59.000Z

    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...

  19. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Lave et al. A Wavelet-based Variability Model (WVM)for Solar PV Powerplants A Wavelet-based Variability Model (Joshua S. Stein Abstract – A wavelet variability model (WVM)

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

    SciTech Connect (OSTI)

    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

    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.

  1. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, G.A.

    1992-11-24T23:59:59.000Z

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

  2. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, Gloria A. (Los Alamos, NM)

    1992-01-01T23:59:59.000Z

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

  3. Multilayer Thermionic Refrigeration

    SciTech Connect (OSTI)

    Mahan, G.D.

    1999-08-30T23:59:59.000Z

    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.

  4. Improving the energy efficiency of refrigerators in India

    SciTech Connect (OSTI)

    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

    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.

  5. STATE OF CALIFORNIA REFRIGERATED WAREHOUSE INSTALLATION CERTIFICATE

    E-Print Network [OSTI]

    STATE OF CALIFORNIA REFRIGERATED WAREHOUSE INSTALLATION CERTIFICATE CEC-RWH-INST (Revised 08 # BUILDING TYPE Refrigerated Warehouse PHASE OF CONSTRUCTION New Construction Addition Alteration If more By the Enforcement Agency #12;STATE OF CALIFORNIA REFRIGERATED WAREHOUSE INSTALLATION CERTIFICATE CEC

  6. Magnetic Refrigeration | GE Global Research

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

    temperature," said Frank Johnson, a materials scientist and project leader on GE's magnetic refrigeration project. Developed over the past decade, these new magnetocaloric...

  7. New Supermarket Refrigeration Systems Reduce Cost

    Office of Energy Efficiency and Renewable Energy (EERE)

    Traditional supermarket refrigeration systems found in most grocery stores across the country are vulnerable to issues which can cause significant refrigerant leakage – especially with older...

  8. New Energy Efficiency Standards for Commercial Refrigeration...

    Office of Environmental Management (EM)

    for Commercial Refrigeration Equipment to Cut Businesses' Energy Bills and Carbon Pollution New Energy Efficiency Standards for Commercial Refrigeration Equipment to Cut...

  9. Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration...

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

    Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems Case Study: Transcritical Carbon Dioxide Supermarket Refrigeration Systems This case study documents one...

  10. Multi-stage Cascaded Stirling Refrigerator

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

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

  11. Relationship between gradient and EM steps in latent variable models.

    E-Print Network [OSTI]

    Roweis, Sam

    includes random search, standard gradient­based algorithms, line search methods such as conjugate gradient to to first order method operat­ ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

  12. Relationship between gradient and EM steps in latent variable models.

    E-Print Network [OSTI]

    Roweis, Sam

    includes random search, standard gradient-based algorithms, line search methods such as conjugate gradient to to first order method operat- ing on the gradient of a locally reshaped likelihood function. DirectRelationship between gradient and EM steps in latent variable models. Ruslan Salakhutdinov Sam

  13. Development of energy-efficiency standards for Indian refrigerators

    SciTech Connect (OSTI)

    Bhatia, P.

    1999-07-01T23:59:59.000Z

    The application of advanced techniques in engineering simulation and economic analysis for the development of efficiency standards for Indian refrigerators is illustrated in this paper. A key feature of this methodology is refrigerator simulation to generate energy savings for a set of energy-efficient design options and life-cycle cost (LCC) analysis with these design options. The LCC of a refrigerator is analyzed as a function of five variables: nominal discount rate, fuel price, appliance lifetime, incremental price, and incremental energy savings. The frequency of occurrence of the LCC minimum at any design option indicates the optimum efficiency level or range. Studies carried out in the US and European Economic Community show that the location of the LCC minimum under different scenarios (e.g., variable fuel price, life-time, discount rate, and incremental price) is quite stable. Thus, an efficiency standard can be developed based on the efficiency value at the LCC minimum. This paper examines and uses this methodology in developing efficiency standards for Indian refrigerators. The potential efficiency standard value is indicated to be 0.65 kWh/day for a 165-liter, CFC-based, manual defrost, single-door refrigerator-freezer.

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

    SciTech Connect (OSTI)

    Rice, C K; Sand, J R

    1993-01-01T23:59:59.000Z

    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.

  15. Extreme solid state refrigeration using nanostructured Bi-Te alloys.

    SciTech Connect (OSTI)

    Lima Sharma, Ana L. (San Jose State University, San Jose, CA); Spataru, Dan Catalin; Medlin, Douglas L.; Sharma, Peter Anand; Morales, Alfredo Martin

    2009-09-01T23:59:59.000Z

    Materials are desperately needed for cryogenic solid state refrigeration. We have investigated nanostructured Bi-Te alloys for their potential use in Ettingshausen refrigeration to liquid nitrogen temperatures. These alloys form alternating layers of Bi{sub 2} and Bi{sub 2}Te{sub 3} blocks in equilibrium. The composition Bi{sub 4}Te{sub 3} was identified as having the greatest potential for having a high Ettingshausen figure of merit. Both single crystal and polycrystalline forms of this material were synthesized. After evaluating the Ettingshausen figure of merit for a large, high quality polycrystal, we simulated the limits of practical refrigeration in this material from 200 to 77 K using a simple device model. The band structure was also computed and compared to experiments. We discuss the crystal growth, transport physics, and practical refrigeration potential of Bi-Te alloys.

  16. Helium dilution refrigeration system

    DOE Patents [OSTI]

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

    1988-09-13T23:59:59.000Z

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

  17. Helium dilution refrigeration system

    DOE Patents [OSTI]

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

    1988-01-01T23:59:59.000Z

    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.

  18. M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle

    E-Print Network [OSTI]

    Bahrami, Majid

    M. Bahrami ENSC 461 (S 11) Refrigeration Cycle 1 Refrigeration Cycle Heat flows in direction a low-temperature to high-temperature requires a refrigerator and/or heat pump. Refrigerators and heat of refrigerators and heat pumps is expressed in terms of coefficient of performance (COP): innet H HP innet L R W Q

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

    E-Print Network [OSTI]

    Cohen, Robert E.

    LAB SAFETY Refrigerator: Refrigerators and freezers are not typically constructed to assure temperature of the refrigerator rises. This results in an increase in the concentration of flammable vapors within the refrigerator's interior. When power is restored, a spark generated by the refrigerator light

  20. Report of Refrigerated Medication Loss UConn Health

    E-Print Network [OSTI]

    Oliver, Douglas L.

    Report of Refrigerated Medication Loss UConn Health Please complete form & return to John Dempsey Other (Specify): Phone: E-mail: Address: Location of Refrigerator Affected: Date/time refrigerator was out of temperature range: Describe the event below: How long was the refrigerator out of range (hours

  1. International Journal of Thermophysics, Vol. 20, No. 1, 1999 Vapor-Liquid Equilibria of Alternative Refrigerants

    E-Print Network [OSTI]

    Lisal, Martin

    Refrigerants by Molecular Dynamics Simulations1 M. Lisal,2 R. Budinsky,3 V. Vacek,3 and K. Aim2, 4 Alternative refrigerants HFC-152a (CHF2CH3), HFC-143a (CF3CH3), HFC- 134a (CF3CH2F), and HCFC-142b (CF2ClCH3) are modeled Republic. 4 To whom correspondence should be addressed. KEY WORDS: alternative refrigerants; Gibbs

  2. Optimization of Industrial Refrigeration Systems 

    E-Print Network [OSTI]

    Flack, P. J.; Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L.

    1995-01-01T23:59:59.000Z

    schematic of a basic two-stage re frigeration system. It shows six of the seven basic components in a refrigeration system; the evaporator, booster or low-stage compressor, intercooler, com pressor or high-stage compressor, condenser and an expansion... the evaporator coils. Air from the refriger ated space is forced over the coils and loses thennal energy to the refrigerant The liquid refrigerant evaporates as it absorbs the them1al energy. The re frigerant leaves the evaporator and enters the booster as a...

  3. Performance bound for quantum absorption refrigerators

    E-Print Network [OSTI]

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

    2013-04-29T23:59:59.000Z

    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.

  4. Solid-Vapor Sorption Refrigeration Systems

    E-Print Network [OSTI]

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

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract... Complex compound sorption reactions are ideally suited for use in refrigeration cycles as an economically viable alternative to CFC refrigerants. Complex compound refrigeration provides a number of energy-saving advantages over present refrigeration...

  5. Design of Industrial Process Refrigeration Systems

    E-Print Network [OSTI]

    Witherell, W. D.

    of the study is discussed in terms of identifying refrigeration intensive processes. Specific and general conclusions are presented to help faci I itate proper industrial refrigeration system design throughout fhe industry. This paper presents the resul ts... custaner's specifications. Most systems fall into two broad categories: Vapor Canpression Refrigeration Cycles - Mechanical or Steam Jet Canpression Systems Absorption Refrigeration Cycles - Heat Operated Cycles As shown in Table I, refrigerations...

  6. Cryogenic refrigeration apparatus

    DOE Patents [OSTI]

    Crunkleton, J.A.

    1992-03-31T23:59:59.000Z

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

  7. Cryogenic refrigeration apparatus

    DOE Patents [OSTI]

    Crunkleton, James A. (Cambridge, MA)

    1992-01-01T23:59:59.000Z

    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.

  8. Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model

    E-Print Network [OSTI]

    O'Neal, D.L.; Bassiouny, R.

    reliability. Short-tubes have either a constant inner dia- meter flow channel or a tapered channel with a smallAbstract A finite element model was used to simulate single-phase flow of R-22 through flexible short-tubes. The numerical model included the fluid... in the flow area. The more flexible (5513 kPa) short-tube restricted the mass flow rate more than the most rigid (9889 kPa) short-tube used in this study. The mass flow rates estimated with the finite element model were as much as 14% higher than those from...

  9. Magnetic refrigeration apparatus and method

    DOE Patents [OSTI]

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

    1984-01-01T23:59:59.000Z

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

  10. Energy Efficient, Environmentally Friendly Refrigerants

    E-Print Network [OSTI]

    Nimitz, J.; Glass, S.; Dhooge, P. M.

    This paper describes a new family of safe, environmentally friendly, high performance substitute refrigerants for application in manufacturing and facilities operations. Due to the Montreal Protocol and subsequent environmental regulations, CFC...

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    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

  12. Analysis of Refrigerant Flow and Deformation for a Flexible Short-Tube using a Finite Element Model 

    E-Print Network [OSTI]

    O'Neal, D.L.; Bassiouny, R.

    2004-01-01T23:59:59.000Z

    an short-tube using a finite element model International Journal of Refrig Vol 27 No 2, pp. 176-183The short-tube is used by United States heat pump manufactures as an expansion device because of its lowAnalyse de l’e´coulement d’un frigorige`ne et...

  13. Non-intrusive refrigerant charge indicator

    DOE Patents [OSTI]

    Mei, Viung C.; Chen, Fang C.; Kweller, Esher

    2005-03-22T23:59:59.000Z

    A non-intrusive refrigerant charge level indicator includes a structure for measuring at least one temperature at an outside surface of a two-phase refrigerant line section. The measured temperature can be used to determine the refrigerant charge status of an HVAC system, and can be converted to a pressure of the refrigerant in the line section and compared to a recommended pressure range to determine whether the system is under-charged, properly charged or over-charged. A non-intrusive method for assessing the refrigerant charge level in a system containing a refrigerant fluid includes the step of measuring a temperature at least one outside surface of a two-phase region of a refrigerant containing refrigerant line, wherein the temperature measured can be converted to a refrigerant pressure within the line section.

  14. GEOCHEMICAL MODELING OF F AREA SEEPAGE BASIN COMPOSITION AND VARIABILITY

    SciTech Connect (OSTI)

    Millings, M.; Denham, M.; Looney, B.

    2012-05-08T23:59:59.000Z

    From the 1950s through 1989, the F Area Seepage Basins at the Savannah River Site (SRS) received low level radioactive wastes resulting from processing nuclear materials. Discharges of process wastes to the F Area Seepage Basins followed by subsequent mixing processes within the basins and eventual infiltration into the subsurface resulted in contamination of the underlying vadose zone and downgradient groundwater. For simulating contaminant behavior and subsurface transport, a quantitative understanding of the interrelated discharge-mixing-infiltration system along with the resulting chemistry of fluids entering the subsurface is needed. An example of this need emerged as the F Area Seepage Basins was selected as a key case study demonstration site for the Advanced Simulation Capability for Environmental Management (ASCEM) Program. This modeling evaluation explored the importance of the wide variability in bulk wastewater chemistry as it propagated through the basins. The results are intended to generally improve and refine the conceptualization of infiltration of chemical wastes from seepage basins receiving variable waste streams and to specifically support the ASCEM case study model for the F Area Seepage Basins. Specific goals of this work included: (1) develop a technically-based 'charge-balanced' nominal source term chemistry for water infiltrating into the subsurface during basin operations, (2) estimate the nature of short term and long term variability in infiltrating water to support scenario development for uncertainty quantification (i.e., UQ analysis), (3) identify key geochemical factors that control overall basin water chemistry and the projected variability/stability, and (4) link wastewater chemistry to the subsurface based on monitoring well data. Results from this study provide data and understanding that can be used in further modeling efforts of the F Area groundwater plume. As identified in this study, key geochemical factors affecting basin chemistry and variability included: (1) the nature or chemistry of the waste streams, (2) the open system of the basins, and (3) duration of discharge of the waste stream types. Mixing models of the archetype waste streams indicated that the overall basin system would likely remain acidic much of the time. Only an extended periods of predominantly alkaline waste discharge (e.g., >70% alkaline waste) would dramatically alter the average pH of wastewater entering the basins. Short term and long term variability were evaluated by performing multiple stepwise modeling runs to calculate the oscillation of bulk chemistry in the basins in response to short term variations in waste stream chemistry. Short term (1/2 month and 1 month) oscillations in the waste stream types only affected the chemistry in Basin 1; little variation was observed in Basin 2 and 3. As the largest basin, Basin 3 is considered the primary source to the groundwater. Modeling showed that the fluctuation in chemistry of the waste streams is not directly representative of the source term to the groundwater (i.e. Basin 3). The sequence of receiving basins and the large volume of water in Basin 3 'smooth' or nullify the short term variability in waste stream composition. As part of this study, a technically-based 'charge-balanced' nominal source term chemistry was developed for Basin 3 for a narrow range of pH (2.7 to 3.4). An example is also provided of how these data could be used to quantify uncertainty over the long term variations in waste stream chemistry and hence, Basin 3 chemistry.

  15. Refrigerator-Freezer Appendix A1 | Department of Energy

    Office of Environmental Management (EM)

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

  16. Integrating giant microwave absorption with magnetic refrigeration in one

    E-Print Network [OSTI]

    Wang, Wei Hua

    Integrating giant microwave absorption with magnetic refrigeration in one multifunctional with magnetic refrigeration in one multifunctional material. This integration not only advances our-compression/expansion refrigeration, magnetic refrigeration exhibits the advantages of high energy efficiency and environment

  17. 2014-09-18 Issuance: Energy Conservation Standard for Alternative Efficiency Determination Methods, Basic Model Definition, and Compliance for Commercial HVAC, Refrigeration, and Water Heating Equipment; Supplemental Notice of Proposed Rulemaking

    Broader source: Energy.gov [DOE]

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

  18. Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling: a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling variability as well as characteristics and hydrological behavior of catchments, we have proceeded simulator and a distributed hydrological model (with four production functions and a distributed transfer

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

    E-Print Network [OSTI]

    Kandlikar, Satish

    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

  20. Quantum Refrigerator and the III-law of Thermodynamics

    E-Print Network [OSTI]

    Amikam Levy; Robert Alicki; Ronnie Kosloff

    2012-05-07T23:59:59.000Z

    The rate of temperature decrease of a cooled quantum bath is studied as its temperature is reduced to the absolute zero. The III-law of thermodynamics is then quantified dynamically by evaluating the characteristic exponent {\\zeta} of the cooling process dT(t)/dt \\sim -T^{\\zeta} when approaching the absolute zero, T \\rightarrow 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 2-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 {\\zeta}, 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 baths models are considered, a bath composed of harmonic oscillators and a bath composed from ideal Bose/Fermi gas. The restrictions on the interaction Hamiltonian imposed by the III-law are discussed. In the appendix the theory of periodicaly driven open systems and its implication to thermodynamics is outlined.

  1. Prototyping of a real size air-conditioning system using a tetra-n-butylammonium bromide semiclathrate hydrate slurry as secondary two-phase refrigerant

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    semiclathrate hydrate slurry as secondary two-phase refrigerant ­ Experimental investigations and modelling). Abstract Among innovative processes developed in the field of refrigeration systems, technologies) is used as secondary refrigerant. The production of the slurry can be smoothed over day and night. Upon

  2. Superinsulation in refrigerators and freezers

    SciTech Connect (OSTI)

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

    1998-02-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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 diameter implies a refrigerant distribution much more penalizing for these exchangers than for round tube

  4. Thermoelectric refrigerator having improved temperature stabilization means

    DOE Patents [OSTI]

    Falco, Charles M. (Woodridge, IL)

    1982-01-01T23:59:59.000Z

    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.

  5. Loveland Water and Power- Refrigerator Recycling Program

    Broader source: Energy.gov [DOE]

    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...

  6. International Refrigeration: Order (2012-CE-1510)

    Broader source: Energy.gov [DOE]

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

  7. Energy Saving with Absorption Refrigeration Technologies

    E-Print Network [OSTI]

    Davis, R. C.

    1984-01-01T23:59:59.000Z

    Absorption refrigeration technology can be an economical and cost effective means of reducing energy cost and/or improving the efficiency and output of your process. We believe the potential benefits of absorption refrigeration technology have...

  8. Frontiers in thermoacoustic refrigeration and mixture separation

    E-Print Network [OSTI]

    and time phases, and isolate the refrigeration from waste heat rejection at the two ambient heat exchangers

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

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01T23:59:59.000Z

    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

  10. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-07-25T23:59:59.000Z

    A ternary magnetic refrigerant material comprising (Dy{sub 1{minus}x}Er{sub x})Al{sub 2} for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant. 29 figs.

  11. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-07-25T23:59:59.000Z

    A ternary magnetic refrigerant material comprising (Dy.sub.1-x Er.sub.x)Al.sub.2 for a magnetic refrigerator using the Joule-Brayton thermodynamic cycle spanning a temperature range from about 60K to about 10K, which can be adjusted by changing the Dy to Er ratio of the refrigerant.

  12. Method and apparatus for desuperheating refrigerant

    DOE Patents [OSTI]

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

    1997-01-01T23:59:59.000Z

    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.

  13. Thermodynamic optimization of heat-driven refrigerators in the transient regime

    SciTech Connect (OSTI)

    Vargas, J.V.C.; Parise, J.A.R.; Ledezma, G.A.; Bianchi, M.V.A.

    2000-02-01T23:59:59.000Z

    The present work introduces a transient endoreversible model of a heat-driven refrigeration plant, which is driven by a fuel-burning heater. The model consists of a combustion chamber with negligible heat loss to the ambient, a refrigerator with three finite-size heat exchangers, namely, the evaporator between the refrigeration load and refrigerant, the condenser between the refrigerant and the ambient, and the generator between the combustion chamber and the refrigerant, and finally the refrigerated space. The total thermal conductance of the three heat exchangers is fixed. A thermodynamic optimization of the absorption cycle is then performed, reporting the operating conditions for minimum time to reach a prescribed cold-space temperature, thus maximum refrigeration rate, specifically, the optimal mass fuel flow rate and the optimal way of allocating the thermal conductance inventory. Half of the total supply of thermal conductance has to be divided equally between the generator and evaporator and the other half allocated to the condenser, for optimal operation. A narrow range of fuel flow rates lead to the minimum time to achieve a prescribed cold-space temperature, thus stressing the importance of the transient analysis. Appropriate dimensionless groups were identified and the generalized results are reported in dimensionless charts.

  14. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM)

    1983-01-01T23:59:59.000Z

    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.

  15. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1982-01-20T23:59:59.000Z

    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.

  16. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-10-11T23:59:59.000Z

    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.

  17. Energy consumption testing of innovative refrigerator-freezers

    SciTech Connect (OSTI)

    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

    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.

  18. 1. Check to make sure all electrical appliances, such as curling irons, toasters, etc. are unplugged. Exceptions are clocks and refrigerators. Keep your refrigerator plugged in!

    E-Print Network [OSTI]

    Minnesota, University of

    . are unplugged. Exceptions are clocks and refrigerators. Keep your refrigerator plugged in! 2. Secure windows

  19. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM)

    1985-01-01T23:59:59.000Z

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

  20. Optimization of Industrial Refrigeration Systems

    E-Print Network [OSTI]

    Flack, P. J.; Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L.

    A computer program designed to optimize the size of an evaporative condenser in a two-stage industrial refrigeration plant was created. The program sizes both the high-stage and low-stage compressors and an evaporative condenser. Once the initial...

  1. Direct condensation refrigerant recovery and restoration system

    SciTech Connect (OSTI)

    Grant, D.C.H.

    1992-03-10T23:59:59.000Z

    This patent describes a refrigerant recovery and purification system for removing gaseous refrigerant from a disabled refrigeration unit, cleaning the refrigerant of contaminants, and converting the gaseous refrigerant to a liquid state for storage. It comprises a low pressure inlet section; a high pressure storage section; the low pressure inlet section comprising: an oil and refrigerant gas separator, including a separated oil removal means, first conduit means for connecting an inlet of the separator to the disabled refrigerant unit, a slack-sided accumulator, second conduit means connecting the separator to the slack-sided accumulator, a reclaim condenser, third conduit means connecting the separator and the reclaim condenser in series, an evaporator coil in the reclaim condenser connectable to a conventional operating refrigeration system for receiving a liquid refrigerant under pressure for expansion therein, the evaporator coil forming a condensing surface for condensing the refrigerant gas at near atmospheric pressure in the condenser, a liquid receiver, a reclaimed refrigerant storage tank, fourth conduit means further connecting the liquid receiver in series with the reclaim condenser, downstream thereof, means between the reclaim condenser and the liquid receiver.

  2. Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 1: Refrigerant Properties

    SciTech Connect (OSTI)

    Mark O. McLinden; Arno Laesecke; Eric W. Lemmon; Joseph W. Magee; Richard A. Perkins

    2002-08-30T23:59:59.000Z

    The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of measuring thermodynamic properties R125, R410A and R507A, measuring viscosity and thermal conductivity of R410A and R507A and comparing data to mixture models in NIST REFPROP database. For R125, isochoric (constant volume) heat capacity was measured over a temperature range of 305 to 397 K (32 to 124 C) at pressures up to 20 MPa. For R410A, isochoric heat capacity was measured along 8 isochores with a temperature range of 303 to 397 K (30 to 124 C) at pressures up to 18 MPa. Pressure-density-temperature was also measured along 14 isochores over a temperature range of 200 to 400 K (-73 to 127 C) at pressures up to 35 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. For R507A, viscosity was measured along 5 isotherms over a temperature range of 301 to 421 K (28 to 148 C) at pressures up to 83 MPa and thermal conductivity along 6 isotherms over a temperature range of 301 to 404 K (28 to 131 C) with pressures to 38 MPa. Mixture models were developed to calculate the thermodynamic properties of HFC refrigerant mixtures containing R32, R125, R134a and/or R125. The form of the model is the same for all the blends considered, but blend-specific mixing functions are required for the blends R32/125 (R410 blends) and R32/134a (a constituent binary of R407 blends). The systems R125/134a, R125/143a, R134a/143a, and R134a/152a share a common, generalized mixing function. The new equation of state for R125 is believed to be the most accurate and comprehensive formulation of the properties for that fluid. Likewise, the mixture model developed in this work is the latest state-of-the-art for thermodynamic properties of HFC refrigerant blends. These models were incorporated into version 7 of NIST REFPROP database.

  3. Investigation of pressure drop in capillary tube for mixed refrigerant Joule-Thomson cryocooler

    SciTech Connect (OSTI)

    Ardhapurkar, P. M. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 India and S. S. G. M. College of Engineering Shegaon, MS 444 203 (India); Sridharan, Arunkumar; Atrey, M. D. [Mechanical Engineering Department, Indian Institute of Technology Bombay, Mumbai, MS 400 076 (India)

    2014-01-29T23:59:59.000Z

    A capillary tube is commonly used in small capacity refrigeration and air-conditioning systems. It is also a preferred expansion device in mixed refrigerant Joule-Thomson (MR J-T) cryocoolers, since it is inexpensive and simple in configuration. However, the flow inside a capillary tube is complex, since flashing process that occurs in case of refrigeration and air-conditioning systems is metastable. A mixture of refrigerants such as nitrogen, methane, ethane, propane and iso-butane expands below its inversion temperature in the capillary tube of MR J-T cryocooler and reaches cryogenic temperature. The mass flow rate of refrigerant mixture circulating through capillary tube depends on the pressure difference across it. There are many empirical correlations which predict pressure drop across the capillary tube. However, they have not been tested for refrigerant mixtures and for operating conditions of the cryocooler. The present paper assesses the existing empirical correlations for predicting overall pressure drop across the capillary tube for the MR J-T cryocooler. The empirical correlations refer to homogeneous as well as separated flow models. Experiments are carried out to measure the overall pressure drop across the capillary tube for the cooler. Three different compositions of refrigerant mixture are used to study the pressure drop variations. The predicted overall pressure drop across the capillary tube is compared with the experimentally obtained value. The predictions obtained using homogeneous model show better match with the experimental results compared to separated flow models.

  4. VAM2D: Variably saturated analysis model in two dimensions

    SciTech Connect (OSTI)

    Huyakorn, P.S.; Kool, J.B.; Wu, Y.S. (HydroGeoLogic, Inc., Herndon, VA (United States))

    1991-10-01T23:59:59.000Z

    This report documents a two-dimensional finite element model, VAM2D, developed to simulate water flow and solute transport in variably saturated porous media. Both flow and transport simulation can be handled concurrently or sequentially. The formulation of the governing equations and the numerical procedures used in the code are presented. The flow equation is approximated using the Galerkin finite element method. Nonlinear soil moisture characteristics and atmospheric boundary conditions (e.g., infiltration, evaporation and seepage face), are treated using Picard and Newton-Raphson iterations. Hysteresis effects and anisotropy in the unsaturated hydraulic conductivity can be taken into account if needed. The contaminant transport simulation can account for advection, hydrodynamic dispersion, linear equilibrium sorption, and first-order degradation. Transport of a single component or a multi-component decay chain can be handled. The transport equation is approximated using an upstream weighted residual method. Several test problems are presented to verify the code and demonstrate its utility. These problems range from simple one-dimensional to complex two-dimensional and axisymmetric problems. This document has been produced as a user's manual. It contains detailed information on the code structure along with instructions for input data preparation and sample input and printed output for selected test problems. Also included are instructions for job set up and restarting procedures. 44 refs., 54 figs., 24 tabs.

  5. Evaluating energy dissipation during expansion in a refrigeration cycle using flue pipe acoustic resonators

    E-Print Network [OSTI]

    Luckyanova, Maria N. (Maria Nickolayevna)

    2008-01-01T23:59:59.000Z

    This research evaluates the feasibility of using a flue pipe acoustic resonator to dissipate energy from a refrigerant stream in order to achieve greater cooling power from a cryorefrigeration cycle. Two models of the ...

  6. Determining the minimum mass and cost of a magnetic refrigerator

    E-Print Network [OSTI]

    Bjørk, R; Bahl, C R H; Pryds, N

    2014-01-01T23:59:59.000Z

    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...

  7. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Power characteristics of PV ensembles: experiences from theproduction of 100 grid connected PV systems distributed overHoff and R. Perez, "Modeling PV Fleet Output Variability,"

  8. Selection of regenerator geometry for magnetic refrigerator applications

    SciTech Connect (OSTI)

    Barclay, J.A.; Sarangi, S.

    1984-01-01T23:59:59.000Z

    In our effort to develop magnetic regenerators of high efficiency we have looked at the following geometries: (1) tube channels in solid block; (2) stack of perforated plates normal to the fluid flow direction; (3) stack of solid plates parallel to fluid flow direction, and packed bed of spherical particles; (4) loose packed; and (5) sintered. Reported are computations of the overall efficiency of the regenerator, considering heat transfer, longitudinal conduction, and fluid pressure drop, for all the above arrangements as a function of geometrical variables, such as overall length and particle diameter or plate thickness. The results yield the optimum geometry for a given combination of other controlling parameters, such as frequency, porosity, and fluid properties. The different geometries are compared under the constraint that the mass of magnetic material is the same for all. This condition is peculiar to the magnetic refrigeration process because the net refrigeration and driving forces are proportional to the mass of magnetic material.

  9. Suction muffler for refrigeration compressor

    DOE Patents [OSTI]

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

    1983-01-25T23:59:59.000Z

    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.

  10. Suction muffler for refrigeration compressor

    DOE Patents [OSTI]

    Nelson, Richard T. (Worthington, OH); Middleton, Marc G. (West Jefferson, OH)

    1983-01-01T23:59:59.000Z

    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.

  11. University of Connecticut Daily Temperature Log Specimen Refrigerator Log

    E-Print Network [OSTI]

    Oliver, Douglas L.

    University of Connecticut Daily Temperature Log ­ Specimen Refrigerator Log Month / Year Clinical ___ Fac. Mgmt. Resolution: 31 ___ Fac. Mgmt. Resolution: If the refrigerator temperature falls out refrigerator. This record must be kept for one year and then destroyed per State requirement

  12. 16 Heat Transfer and Air Flow in a Domestic Refrigerator

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel...............................................447 16.2.1 Studies in Domestic Refrigerators...................................................................................... 451 16.3 Cold Production System in Domestic Refrigerators

  13. Layer of protection analysis applied to ammonia refrigeration systems

    E-Print Network [OSTI]

    Zuniga, Gerald Alexander

    2009-05-15T23:59:59.000Z

    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...

  14. Covered Product Category: Refrigerated Beverage Vending Machines...

    Energy Savers [EERE]

    ENERGY STAR product specification applies to new and remanufactured indoor (i.e., glass front) and indooroutdoor (i.e., solid front) refrigerated beverage vending machines....

  15. Covered Product Category: Commercial Refrigerators and Freezers

    Broader source: Energy.gov [DOE]

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

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    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...

  17. Bayesian latent variable modelling in studies of air pollution and health

    E-Print Network [OSTI]

    Burton, Geoffrey R.

    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 air pollution on respiratory mortality in the elderly (aged 65 and above) in London, England, between

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

    E-Print Network [OSTI]

    Hansen, René Rydhof

    Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault to the grid connection of wind turbines. The second chapter elucidates recent thinking in the area of grid Risø National Laboratory Vestas Wind Systems A/S #12;#12;I Modelling and Analysis of Variable Speed

  19. New Refrigerant Boosts Energy Efficiency of Supermarket Display...

    Energy Savers [EERE]

    New Refrigerant Boosts Energy Efficiency of Supermarket Display Cases New Refrigerant Boosts Energy Efficiency of Supermarket Display Cases February 20, 2015 - 4:55pm Addthis New...

  20. Natural Refrigerant High-Performance Heat Pump for Commercial...

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

    Natural Refrigerant High-Performance Heat Pump for Commercial Applications Natural Refrigerant High-Performance Heat Pump for Commercial Applications Lead Performer: S-RAM -...

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

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

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

  2. High-Performance Refrigerator Using Novel Rotating Heat Exchanger...

    Energy Savers [EERE]

    energy savings of 407 TBtuyear when implemented in both residential and commercial refrigeration. The first proof of concept will be in a residential refrigerator....

  3. 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...

  4. Active Diesel Emission Control Technology for Transport Refrigeration...

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

    Transport Refrigeration Units Active Diesel Emission Control Technology for Transport Refrigeration Units This project discusses a CARB Level 2+ verified active regeneration...

  5. 2014-04-10 Issuance: Test Procedures for Commercial Refrigeration...

    Energy Savers [EERE]

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

  6. 2014-11-26 Issuance: Test Procedures for Miscellaneous Refrigeration...

    Office of Environmental Management (EM)

    6 Issuance: Test Procedures for Miscellaneous Refrigeration Products; Notice of Proposed Rulemaking 2014-11-26 Issuance: Test Procedures for Miscellaneous Refrigeration Products;...

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

    Energy Savers [EERE]

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

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

    Energy Savers [EERE]

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

  9. Limited Dependent Variable Correlated Random Coefficient Panel Data Models

    E-Print Network [OSTI]

    Liang, Zhongwen

    2012-10-19T23:59:59.000Z

    OF CONTENTS : : : : : : : : : : : : : : : : : : : : : : : : : : : : : vii LIST OF TABLES : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : ix 1. INTRODUCTION : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 1.1 Linear Models... : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 2 1.2 Binary Response Models : : : : : : : : : : : : : : : : : : : : : : : : : 3 1.3 Truncated Models : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 6 2. LINEAR CRC PANEL DATA MODELS : : : : : : : : : : : : : : : : : : 8 2.1...

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

    SciTech Connect (OSTI)

    Johnson, Francis

    2014-06-30T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

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

    2004-08-30T23:59:59.000Z

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

  12. Modeling a Snap-Action, Variable-Delay Switch

    E-Print Network [OSTI]

    Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America, 2, Cambridge, Massachusetts, United States of America When exposed to tumor necrosis factor (TNF) or TNFModeling a Snap-Action, Variable-Delay Switch Controlling Extrinsic Cell Death John G. Albeck1

  13. Natural Refrigerant, Geothermal Heating & Cooling Solutions

    E-Print Network [OSTI]

    Natural Refrigerant, Geothermal Heating & Cooling Solutions Lalit Chordia, PhD, Marc Portnoff 150.thargeo.com Thar Geothermal, LLC © 2013 All Rights Reserved CO2MFORT ADVANTAGE Nature's Talk Outline · Introduction to Thar Geothermal · Carbon Dioxide (R744) the Environmentally Exceptional Refrigerant · Thar

  14. Seven-effect absorption refrigeration

    DOE Patents [OSTI]

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

    1989-01-01T23:59:59.000Z

    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.

  15. Seven-effect absorption refrigeration

    DOE Patents [OSTI]

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

    1989-05-09T23:59:59.000Z

    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.

  16. Examining Uncertainty in Demand Response Baseline Models and Variability in Automated Response to Dynamic Pricing

    SciTech Connect (OSTI)

    Mathieu, Johanna L.; Callaway, Duncan S.; Kiliccote, Sila

    2011-08-15T23:59:59.000Z

    Controlling electric loads to deliver power system services presents a number of interesting challenges. For example, changes in electricity consumption of Commercial and Industrial (C&I) facilities are usually estimated using counterfactual baseline models, and model uncertainty makes it difficult to precisely quantify control responsiveness. Moreover, C&I facilities exhibit variability in their response. This paper seeks to understand baseline model error and demand-side variability in responses to open-loop control signals (i.e. dynamic prices). Using a regression-based baseline model, we define several Demand Response (DR) parameters, which characterize changes in electricity use on DR days, and then present a method for computing the error associated with DR parameter estimates. In addition to analyzing the magnitude of DR parameter error, we develop a metric to determine how much observed DR parameter variability is attributable to real event-to-event variability versus simply baseline model error. Using data from 38 C&I facilities that participated in an automated DR program in California, we find that DR parameter errors are large. For most facilities, observed DR parameter variability is likely explained by baseline model error, not real DR parameter variability; however, a number of facilities exhibit real DR parameter variability. In some cases, the aggregate population of C&I facilities exhibits real DR parameter variability, resulting in implications for the system operator with respect to both resource planning and system stability.

  17. Counterflow absorber for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01T23:59:59.000Z

    An air-cooled, vertical tube absorber for an absorption refrigeration system is disclosed. Strong absorbent solution is supplied to the top of the absorber and refrigerant vapor is supplied to the bottom of the absorber to create a direct counterflow of refrigerant vapor and absorbent solution in the absorber. The refrigeration system is designed so that the volume flow rate of refrigerant vapor in the tubes of the absorber is sufficient to create a substantially direct counterflow along the entire length of each tube in the absorber. This provides several advantages for the absorber such as higher efficiency and improved heat transfer characteristics, and allows improved purging of non-condensibles from the absorber.

  18. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

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

    1985-01-01T23:59:59.000Z

    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.

  19. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

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

    1985-05-14T23:59:59.000Z

    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.

  20. Optimal Performance of Quantum Refrigerators

    E-Print Network [OSTI]

    Tova Feldmann; Ronnie Kosloff

    2009-09-08T23:59:59.000Z

    A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling to absolute zero. We find that if the energy spectrum of the working medium possesses an uncontrollable gap, then there is a minimum achievable temperature above zero. Such a gap, combined with a negligible amount of noise, prevents adiabatic following during the demagnetization stage which is the necessary condition for reaching $T_c \\to 0$. The refrigerator is based on an Otto cycle where the working medium is an interacting spin system with an energy gap. For this system the external control Hamiltonian does not commute with the internal interaction. As a result during the demagnetization and magnetization segments of the operating cycle the system cannot follow adiabatically the temporal change in the energy levels. We connect the nonadiabatic dynamics to quantum friction. An adiabatic measure is defined characterizing the rate of change of the Hamiltonian. Closed form solutions are found for a constant adiabatic measure for all the cycle segments. We have identified a family of quantized frictionless cycles with increasing cycle times. These cycles minimize the entropy production. Such frictionless cycles are able to cool to $T_c=0$. External noise on the controls eliminates these frictionless cycles. The influence of phase and amplitude noise on the demagnetization and magnetization segments is explicitly derived. An extensive numerical study of optimal cooling cycles was carried out which showed that at sufficiently low temperature the noise always dominates restricting the minimum temperature.

  1. Inferring Variable Conflicts for Local Search from High-Level Models

    E-Print Network [OSTI]

    Flener, Pierre

    Inferring Variable Conflicts for Local Search from High-Level Models Magnus °Agren, Pierre Flener in local search algorithms are often shrunk by only considering moves modifying variables that actually for speeding up search. State-of-the-art solutions to, e.g., the progressive party problem exploit

  2. clustvarsel: A Package Implementing Variable Selection for Model-based Clustering in R

    E-Print Network [OSTI]

    Washington at Seattle, University of

    is performed using either a stepwise greedy search or a headlong algorithm. Adjustments for speeding up subset of variables with group/cluster information in a dataset. Search over the solution spaceclustvarsel: A Package Implementing Variable Selection for Model-based Clustering in R Luca Scrucca

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

    E-Print Network [OSTI]

    Mills, Richard

    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

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

    SciTech Connect (OSTI)

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

    1997-12-31T23:59:59.000Z

    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.

  5. Process Systems Engineering Optimal Synthesis of Refrigeration Cycles

    E-Print Network [OSTI]

    Maranas, Costas

    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

  6. Refrigerator Recycling Evaluation Protocol Doug Bruchs, The Cadmus Group, Inc.

    E-Print Network [OSTI]

    1 Refrigerator Recycling Evaluation Protocol Doug Bruchs, The Cadmus Group, Inc. Refrigerator Description Refrigerator recycling programs are designed to save energy through the removal of old-but- operable refrigerators from service. By offering free pick-up, providing incentives, and disseminating

  7. USDA Food Safety News Alert Cleaning the Office Refrigerator

    E-Print Network [OSTI]

    Watson, Craig A.

    USDA Food Safety News Alert Cleaning the Office Refrigerator When it comes to safe food handling, everything that comes in contact with food must be kept clean -- including the refrigerator. You probably keep your refrigerator at home clean, but the office refrigerator may be a problem because it

  8. Dual-circuit, multiple-effect refrigeration system and method

    DOE Patents [OSTI]

    DeVault, Robert C. (Knoxville, TN)

    1995-01-01T23:59:59.000Z

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

  9. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Boeder, A; Zimm, C

    2006-09-30T23:59:59.000Z

    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.

  10. Refrigerant charge management in a heat pump water heater

    DOE Patents [OSTI]

    Chen, Jie; Hampton, Justin W.

    2014-06-24T23:59:59.000Z

    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.

  11. Accounting for the Occupancy Variable in Inverse Building Energy Baselining Models

    E-Print Network [OSTI]

    Claridge, D. E.

    2001-01-01T23:59:59.000Z

    .1-1989, Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings. American Society of Heating, Refrigerating and Air-conditioning Engineers. Atlanta, Georgia. Bronson, D., 1992, ?Calibrated Computer Simulations for the Analysis of Retrofit...

  12. China Refrigerator Information Label: Specification Development and Potential Impact

    SciTech Connect (OSTI)

    Fridley, David; Fridley, David; Zheng, Nina; Zhou, Nan; Aden, Nathaniel; Lin, Jiang; Jianhong, Cheng; Sakamoto, Tomoyuki

    2008-02-01T23:59:59.000Z

    In the last five years, China's refrigerator market has grown rapidly, and now urban markets are showing signs of saturation, with ownership rates in urban households reaching 92%. Rural markets continue to grow from a much lower base. As a result of this growth, the Chinese government in 2006 decided to revise the refrigerator standards and its associated efficiency grades for the mandatory energy information label. In the Chinese standards process, the efficiency grades for the information label are tied to the minimum standards. Work on the minimum standards revision began in 2006 and continued through the first half of 2007, when the draft standard was completed under the direction of the China National Institute of Standardization (CNIS). Development of the information label grades required consideration of stakeholder input, continuity with the previous grade classification, ease of implementation, and potential impacts on the market. In this process, CLASP, with the support of METI/IEEJ, collaborated with CNIS to develop the efficiency grades, providing technical input to the process, comment and advice on particular technical issues, and evaluation of the results. After three months of effort and three drafts of the final grade specifications, this work was completed. In addition, in order to effectively evaluate the impact of the label on China's market, CLASP further provided assistance to CNIS to collect data on both the efficiency distribution and product volume distribution of refrigerators on the market. The new information label thresholds to be implemented in 2008 maintain the approach first adopted in 2005 of establishing efficiency levels relative to the minimum standard, but increased the related required efficiency levels by 20% over those established in 2003 and implemented in 2005. The focus of improvement was on the standard refrigerator/freezer (class 5), which constitutes the bulk of the Chinese market. Indeed, the new requirements to achieve grade 1 on the label are now virtually as stringent as those for US Energy Star-qualified or EU A-grade refrigerators. When the energy information label went into effect in March 2005, refrigerator manufacturers were required to display their declared level of efficiency on the label and report it to the China Energy Label Center (CELC), a newly established unit of CNIS responsible for label program management. Because of the visible nature of the label, it was found, through a METI/IEEJ-supported study, that MEPS non-compliance dropped from 4% to zero after the label became mandatory, and that the percentage of higher-grade refrigerators increased. This suggests that the label itself does have potential for shifting the market to higher-efficiency models (Lin 2007). One challenge, however, of assessing this potential impact is the lack of a comprehensive baseline of market efficiency and a program to evaluate the market impact on a yearly basis. As a result, the impact evaluation in this study draws upon the market transformation experience of the related EU energy information label, for which quantitative assessments of its market impact exist. By assuming a parallel process unfolding in China, it is possible to look at the potential impact of the label to 2020. The results of the analysis demonstrates that a robust market transformation program in China focused on the energy information label could save substantial amounts of electricity by 2020, totaling 16.4 TWh annually by that year, compared to a case in which the efficiency distribution of refrigerators was frozen at the 2007 level. Remarkably, the impact of a successful market transformation program with the label would essentially flatten the consumption of electricity for refrigerator use throughout most of the next decade, despite the expectations of continued growth in total stock by nearly 190 million units. At the end of this period, total consumption begins to rise again, as the least efficient of the units have been mostly removed from the market. Such a level of savings would reduce CO{sub

  13. ASHRAE/NIST Refrigerants Conference International concerns about the impact of refrigerants on climate change drive the

    E-Print Network [OSTI]

    Ginzel, Matthew

    ASHRAE/NIST Refrigerants Conference International concerns about the impact of refrigerants on climate change drive the need to look at new cooling and refrigeration options that are sustainable" refrigerants through papers, presentations and panel discussions. This is the fourth jointly sponsored

  14. Refrigerator Magnets It seems that, these days, the home refrigerator was invented primarily as a venue for displaying

    E-Print Network [OSTI]

    Lü, James Jian-Qiang

    1 Refrigerator Magnets Ken Connor It seems that, these days, the home refrigerator was invented creativity, some very bright person conceived of the refrigerator magnet. Most homes have at least several. Refrigerator magnets and other simple applications of electromagnetic phenomena can be very helpful

  15. Magnetic refrigeration: Materials, design, and applications. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1995-12-01T23:59:59.000Z

    The bibliography contains citations concerning cryogenics using magnetic refrigerants. Refrigerant properties, magnetic materials, and thermal characteristics are discussed. Magnetic refrigerators are used for helium liquefaction, cooling superconductors, and superfluid helium production. Carnot-cycle refrigerators, reciprocating refrigerators, parasitic refrigerators, Ericsson refrigerators, and Stirling cycle refrigerators are among the types of magnetic refrigerators evaluated. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  16. Magnetic refrigeration: Materials, design, and applications. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1995-01-01T23:59:59.000Z

    The bibliography contains citations concerning cryogenics using magnetic refrigerants. Refrigerant properties, magnetic materials, and thermal characteristics are discussed. Magnetic refrigerators are used for helium liquefaction, cooling superconductors, and superfluid helium production. Carnot-cycle refrigerators, reciprocating refrigerators, parasitic refrigerators, Ericsson refrigerators, and Stirling cycle refrigerators are among the types of magnetic refrigerators evaluated. (Contains a minimum of 118 citations and includes a subject term index and title list.)

  17. Quantitative Analysis of Variability and Uncertainty in Environmental Data and Models

    E-Print Network [OSTI]

    Frey, H. Christopher

    Quantitative Analysis of Variability and Uncertainty in Environmental Data and Models Volume 1 ........................................6 1.3 Is A Probabilistic Analysis Necessary? ................................................................8 1.4 Previous Work in Probabilistic Risk Assessment

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

    E-Print Network [OSTI]

    Furr, James C., Jr

    2007-09-17T23:59:59.000Z

    Empirical models of airflow output and power consumption were developed for series and parallel fan powered variable air volume terminal units at typical design pressure conditions. A testing procedure and experimental setup were developed to test...

  19. 16.4 HODOGRAPH VARIABILITY WITHIN ANALYTICALLY MODELED BAROCLINIC WAVES Peter C. Banacos

    E-Print Network [OSTI]

    wavelength, R is the gas constant for dry air, a is the meridional temperature gradient, is a parameter geopotential, Table 1. Parameter values used in individual model runs variable (units) "control" value

  20. Quantum refrigerator driven by current noise

    E-Print Network [OSTI]

    Yi-Xin Chen; Sheng-Wen Li

    2011-04-13T23:59:59.000Z

    We proposed a scheme to implement a self-contained quantum refrigerator system composed of three rf-SQUID qubits, or rather, flux-biased phase qubits. The three qubits play the roles of the target, the refrigerator and the heat engine respectively. We provide different effective temperatures for the three qubits, by imposing external current noises of different strengths. The differences of effective temperatures give rise to the flow of free energy and that drives the refrigerator system to cool down the target. We also show that the efficiency of the system approaches the Carnot efficiency.

  1. DOE/AHAM advanced refrigerator technology development project

    SciTech Connect (OSTI)

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

    1997-03-01T23:59:59.000Z

    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.

  2. Bearing construction for refrigeration compresssor

    DOE Patents [OSTI]

    Middleton, Marc G. (Wyoming, MI); Nelson, Richard T. (Worthington, OH)

    1988-01-01T23:59:59.000Z

    A hermetic refrigeration compressor has a cylinder block and a crankshaft rotatable about a vertical axis to reciprocate a piston in a cylinder on the cylinder block. A separate bearing housing is secured to the central portion of the cylinder block and extends vertically along the crankshaft, where it carries a pair of roller bearings to journal the crankshaft. The crankshaft has a radially extending flange which is journaled by a thrust-type roller bearing above the bearing housing to absorb the vertical forces on the crankshaft so that all three of the roller bearings are between the crankshaft and the bearing housing to maintain and control the close tolerances required by such bearings.

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

    SciTech Connect (OSTI)

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

    2012-01-01T23:59:59.000Z

    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.

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

    SciTech Connect (OSTI)

    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

    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.

  5. Limited Dependent Variable Correlated Random Coefficient Panel Data Models 

    E-Print Network [OSTI]

    Liang, Zhongwen

    2012-10-19T23:59:59.000Z

    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...

  6. 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

  7. Defrost Temperature Termination in Supermarket Refrigeration Systems

    SciTech Connect (OSTI)

    Fricke, Brian A [ORNL; Sharma, Vishaldeep [ORNL

    2011-11-01T23:59:59.000Z

    The objective of this project was to determine the potential energy savings associated with implementing demand defrost strategies to defrost supermarket refrigerated display case evaporators, as compared to the widely accepted current practice of controlling display case defrost cycles with a preset timer. The defrost heater energy use of several representative display case types was evaluated. In addition, demand defrost strategies for refrigerated display cases as well as those used in residential refrigerator/freezers were evaluated. Furthermore, it is anticipated that future work will include identifying a preferred defrost strategy, with input from Retail Energy Alliance members. Based on this strategy, a demand defrost system will be designed which is suitable for supermarket refrigerated display cases. Limited field testing of the preferred defrost strategy will be performed in a supermarket environment.

  8. Intra-molecular refrigeration in enzymes

    E-Print Network [OSTI]

    Hans J. Briegel; Sandu Popescu

    2009-12-14T23:59:59.000Z

    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.

  9. Elastic Metal Alloy Refrigerants: Thermoelastic Cooling

    SciTech Connect (OSTI)

    None

    2010-10-01T23:59:59.000Z

    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.

  10. Energy use of icemaking in domestic refrigerators

    SciTech Connect (OSTI)

    Meier, A. [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.; Martinez, M.S. [ENVEST-SCE, Irwindale, CA (United States)

    1996-02-01T23:59:59.000Z

    This study was designed to develop and test a procedure to measure the electrical consumption of ice making in domestic refrigerators. The Department of Energy (DOE) test procedure was modified to include the energy used for icemaking in conventional refrigerators and those equipped with automatic icemakers. The procedure assumed that 500 grams of ice would be produced daily. Using the new test procedure and the existing DOE test (as a benchmark), four refrigerators equipped with automatic icemakers were tested for ice-making energy use. With the revised test, gross electricity consumption increased about 10% (100 kWh/yr) due to automatic icemaking but about 5% (55 kWh/yr) could be attributed to the special features of the automatic icemaker. The test also confirmed the feasibility of establishing procedures for measuring energy use of specific loads and other activities related to domestic refrigerators. Field testing and subsequent retesting revealed a 14% increase in energy use.

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

    Broader source: Energy.gov [DOE]

    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.

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

    Broader source: Energy.gov [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.

  13. Improving Industrial Refrigeration System Efficiency - Actual Applications

    E-Print Network [OSTI]

    White, T. L.

    1980-01-01T23:59:59.000Z

    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...

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

    Broader source: Energy.gov [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.

  15. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, D.P.

    1984-06-05T23:59:59.000Z

    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.

  16. Solid-Vapor Sorption Refrigeration Systems 

    E-Print Network [OSTI]

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

    1991-01-01T23:59:59.000Z

    SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL DR. UWE ROCKENFELLER MR. LANCE KIROL Engineer President Chief Engineer Rocky Research Rocky Research Rocky Research Boulder city, NV Boulder city, NV Boulder City, NV Abstract.... Complex compounds have a number of advantages as working media, including: 43 SOLID-VAPOR SORPTION REFRIGERATION SYSTEMS DR. WILLIAM GRAEBEL Engineer Rocky Research Boulder city, NV DR. UWE ROCKENFELLER President Rocky Research Boulder city, NV MR...

  17. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, Donald P. (Southold, NY)

    1985-01-01T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Nutter, Darin Wayne

    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...

  19. Atmospheric Horizontal Resolution Affects Tropical Climate Variability in Coupled Models

    E-Print Network [OSTI]

    Guilyardi, Eric

    di Geofisica e Vulcanologia, Bologna, Italy S. BEHERA, J.-J. LUO, AND S. MASSON Frontier Research model, SINTEX-Frontier (SINTEX-F), developed jointly at Istituto Nazionale di Geofisica e Vulcanologia that the Corresponding author address: A. Navarra, Istituto Nazionale di Geofisica e Vulcanologia, Via Donato Creti 12

  20. Model-Checking Systems with Unbounded Variables without Abstraction

    E-Print Network [OSTI]

    Pierre, Laurence

    Pierre2 1 CMI/Universit´e de Provence 39 Rue Joliot-Curie 13453 Marseille cedex 13 - France Magali.Contensin@cmi of a model-checker for the modal - calculus with a theorem prover, first theoretical results were reported

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

    E-Print Network [OSTI]

    Wilson, Benton Wade

    2004-09-30T23:59:59.000Z

    " 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...

  2. Seasonal and Interannual Variability in the Circulation of Puget Sound, Washington: A Box Model Study

    E-Print Network [OSTI]

    MacCready, Parker

    Seasonal and Interannual Variability in the Circulation of Puget Sound, Washington: A Box Model A prognostic, time-dependent box model of circulation in Puget Sound, Washington is used to study seasonal circulation dans le détroit de Puget, dans l'État de Washington, pour étudier les variations saisonnières et

  3. Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 Finite Bisimulation of Reactive Untimed Infinite State Systems Modeled as Automata with Variables for reactive untimed infinite state systems called input- output extended finite automaton (I/O-EFA), which of a finite bisimilar abstraction. The results are illustrated through examples that model reactive software

  4. The Role of Aspects in Modeling Product Line Variabilities Jing (Janet) Liu

    E-Print Network [OSTI]

    Lutz, Robyn R.

    for handling crosscutting concerns [47] in all phases of the software development lifecycle. Several approaches-driven development of software product lines. Although some preliminary studies exist at the requirements-Driven Development, Software Product Lines, Variability, Aspect, Aspect-Oriented Modeling. 1. INTRODUCTION Model

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

    E-Print Network [OSTI]

    Sanders, Seth

    systems. A scheme for control of electrical power flow is proposed for machines with variable­speed six (e.g. in implement- ing torque or power control), the mechanical dynamics of the model can to select a drive scheme before embarking on the system modelling and subsequent control design. Each drive

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

    E-Print Network [OSTI]

    Boyer, Edmond

    Sequential Thermo-Hydraulic Modeling of Variably Saturated Flow in High-Level Radioactive Waste-Malabry, France Key words: waste repository, geological disposal, thermo- hydraulic modeling Introduction The most long-lived radioactive wastes must be managed in a safe way for human health and for the environment

  7. Concrete calcium leaching at variable temperature: experimental data and numerical model inverse

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , concrete porous solution is very basic (pH around 13) and several ionic species are highly concentrated [1Concrete calcium leaching at variable temperature: experimental data and numerical model inverse/DSU/SSIAD/BERIS, Fontenay-aux-Roses, France Abstract A simplified model for calcium leaching in concrete is presented

  8. Investigation of design options for improving the energy efficiency of conventionally designed refrigerator-freezers

    SciTech Connect (OSTI)

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

    1993-11-01T23:59:59.000Z

    Several design options for improving the energy efficiency of conventionally-designed, domestic refrigerator freezers (RFs) were incorporated into two 1990 production RF cabinets and refrigeration systems. The baseline performance of the original units and unit components were extensively documented to provide a firm basis for experimentally measured energy savings. A detailed refrigerator system computer model which could simulate cycling behavior was used to evaluate the daily energy use impacts for each modification, and modeled versus experimental results are compared. The model was shown to track measured RF performance improvement sufficiently well that it was used with some confidence to investigate additional options that could not be experimentally investigated. Substantial improvements in RF efficiency were demonstrated with relatively minor changes in system components and refrigeration circuit design. However, each improvement exacts a penalty in terms of increased cost or system complexity/reliability. For RF sizes typically sold in the United States (18-22 ft{sup 3} [510--620 1]), alternative, more-elaborate, refrigeration cycles may be required to achieve the program goal (1.00 Kilowatt-hour per day for a 560 l, top mount RF.

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

    E-Print Network [OSTI]

    Zuo, Z.; Hu, W.

    2006-01-01T23:59:59.000Z

    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...

  10. Barocaloric effect and the pressure induced solid state refrigerator

    SciTech Connect (OSTI)

    Oliveira, N. A. de [Instituto de Fisica Armando Dias Tavares Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, Rio de Janeiro, 20550-013, RJ (Brazil)

    2011-03-01T23:59:59.000Z

    The current refrigerators are based on the heating and cooling of fluids under external pressure variation. The great inconvenience of this refrigeration technology is the damage caused to the environment by the refrigerant fluids. In this paper, we discuss the magnetic barocaloric effect, i.e., the heating or cooling of magnetic materials under pressure variation and its application in the construction of refrigerators using solid magnetic compounds as refrigerant materials and pressure as the external agent. The discussion presented in this paper points out that such a pressure induced solid state refrigerator can be very interesting because it is not harmful to the environment and can exhibit a good performance.

  11. MODELING CYCLIC VARIABILITY IN SPARK-ASSISTED HCCI

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL; Wagner, Robert M [ORNL; Edwards, Kevin Dean [ORNL; Green Jr, Johney Boyd [ORNL

    2008-01-01T23:59:59.000Z

    Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark-assist to expand the operating range of HCCI combustion.

  12. Modeling Cyclic Variability in Spark-Assisted HCCI

    SciTech Connect (OSTI)

    Daw, C Stuart [ORNL; Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL; Green Jr, Johney Boyd [ORNL

    2008-01-01T23:59:59.000Z

    Spark assist appears to offer considerable potential for increasing the speed and load range over which homogeneous charge compression ignition (HCCI) is possible in gasoline engines. Numerous experimental studies of the transition between conventional spark-ignited (SI) propagating-flame combustion and HCCI combustion in gasoline engines with spark assist have demonstrated a high degree of deterministic coupling between successive combustion events. Analysis of this coupling suggests that the transition between SI and HCCI can be described as a sequence of bifurcations in a low-dimensional dynamic map. In this paper, we describe methods for utilizing the deterministic relationship between cycles to extract global kinetic rate parameters that can be used to discriminate multiple distinct combustion states and develop a more quantitative understanding of the SI-HCCI transition. We demonstrate the application of these methods for indolene-containing fuels and point out an apparent HCCI mode switching not previously reported. Our results have specific implications for developing dynamic combustion models and feedback control strategies that utilize spark assist to expand the operating range of HCCI combustion.

  13. Task Modeling in Imitation Learning using Latent Variable Models Carl Henrik Ek, Dan Song, Kai Huebner and Danica Kragic

    E-Print Network [OSTI]

    Ek, Carl Henrik

    in the sensorimotor systems, [4] proposed a coherent control, trajectory optimization, and action planningTask Modeling in Imitation Learning using Latent Variable Models Carl Henrik Ek, Dan Song, Kai about different manipulation tasks from scene observations. In this paper we present a probabilistic

  14. Quantum heat engines and refrigerators: Continuous devices

    E-Print Network [OSTI]

    Ronnie Kosloff; Amikam Levy

    2013-10-02T23:59:59.000Z

    Quantum thermodynamics supplies a consistent description of quantum heat engines and refrigerators up to the level of a single few level system coupled to the environment. Once the environment is split into three;a hot, cold and work reservoirs a heat engine can operate. The device converts the positive gain into power;where the gain is obtained from population inversion between the components of the device. Reversing the operation transforms the device into a quantum refrigerator. The quantum tricycle, a device connected by three external leads to three heat reservoirs is used as a template for engines and refrigerators. The equation of motion for the heat currents and power can be derived from first principle. Only a global description of the coupling of the device to the reservoirs is consistent with the first and second laws of thermodynamics. Optimisation of the devices leads to a balanced set of parameters where the couplings to the three reservoirs are of the same order and the external driving field is in resonance. When analysing refrigerators special attention is devoted to a dynamical version of the third law of thermodynamics. Bounds on the rate of cooling when approaching the absolute zero are obtained by optimising the cooling current. At low temperature all refrigerators show universal behavior. Restrictions on the system imposed by the dynamical version of the third law are studied.

  15. Potential Refrigerants for Power Electronics Cooling

    SciTech Connect (OSTI)

    Starke, M.R.

    2005-10-24T23:59:59.000Z

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

  16. adiabatic demagnetization refrigerator: Topics by E-print Network

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

    refrigeration, steam... Zuo, Z.; Hu, W. 2006-01-01 287 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  17. absorption-recompression refrigeration cycle: Topics by E-print...

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

    refrigeration, steam... Zuo, Z.; Hu, W. 2006-01-01 70 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  18. DOE EPCA Commercial Refrigeration Standards - EERE-2010-BT-STD...

    Office of Environmental Management (EM)

    EPCA Commercial Refrigeration Standards - EERE-2010-BT-STD-0003 (RIN) 1904-AC19 DOE EPCA Commercial Refrigeration Standards - EERE-2010-BT-STD-0003 (RIN) 1904-AC19 In today's...

  19. Optimal Design Refrigeration System for a Mucilage Glue Fiber Factory 

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    to fully use the compression heat of refrigerator, reduces the pipeline, Saves the investment. The workshop best arrangement is take refrigeration workshop and the soft water workshop as the center, various workshops around them, chart 4 shows...

  20. Fully portable, highly flexible dilution refrigerator systems for neutron scattering

    E-Print Network [OSTI]

    Boyer, Edmond

    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

  1. Microcomputer Software for Refrigerant Property and Cycle Analysis Calculations

    E-Print Network [OSTI]

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

    the thermodynamic properties of ten fluorocarbon refrigerants, (Rll, R12, R13, R14, R22, R23, Rl13, Rl14, R500, R502) and ammonia in the sub-cooled, saturation, 2-phase, and superheat regions. In the sec tions which follow, the theoretical basis... for each fluorocarbon refrigerant, represent curve fits to existing tabular property data. For both ammonia and the fluorocarbon refrigerants, the equations for the following four basic properties of refrigerants are used. - Liquid density as a...

  2. Short Time Cycles of Purely Quantum Refrigerators

    E-Print Network [OSTI]

    Tova Feldmann; Ronnie Kosloff

    2012-04-18T23:59:59.000Z

    Four stroke Otto refrigerator cycles with no classical analogue are studied. Extremely short cycle times with respect to the internal time scale of the working medium characterize these refrigerators. Therefore these cycles are termed sudden. The sudden cycles are characterized by the stable limit cycle which is the invariant of the global cycle propagator. During their operation the state of the working medium possesses significant coherence which is not erased in the equilibration segments due to the very short time allocated. This characteristic is reflected in a difference between the energy entropy and the Von Neumann entropy of the working medium. A classification scheme for sudden refrigerators is developed allowing simple approximations for the cooling power and coefficient of performance.

  3. Basics of Low-temperature Refrigeration

    E-Print Network [OSTI]

    Alekseev, A

    2014-01-01T23:59:59.000Z

    This chapter gives an overview of the principles of low temperature refrigeration and the thermodynamics behind it. Basic cryogenic processes - Joule-Thomoson process, Brayton process as well as Claude process - are described and compared. A typical helium laboratory refrigerator based on Claude process is used as a typical example of a low-temperature refrigeration system. A description of the hardware components for helium liquefaction is an important part of this paper, because the design of the main hardware components (compressors, turbines, heat exchangers, pumps, adsorbers, etc.) provides the input for cost calculation, as well as enables to estimate the reliability of the plant and the maintenance expenses. All these numbers are necessary to calculate the economics of a low temperature application.

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

    SciTech Connect (OSTI)

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

    2013-01-01T23:59:59.000Z

    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.

  5. page 1 of 5 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    page 1 of 5 TkF Värmeteknik Refrigeration / Kylteknik Ron Zevenhoven Exam 11-2-2009 4 questions. A two-stage vapour-compression process, using refrigerant R-22, operates between the temperatures 36 °C and -58°C, with intermediate temperature 0°C. The refrigerant mass streams through the high temperature

  6. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki) Francesco Giazotto (SNS Pisa) Yuri Pashkin (NEC) #12;Outline Electronic refrigeration Classical vs quantum (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single

  7. HANDLING FRESH FISH REFRIGERATION OF FISH -PART 2

    E-Print Network [OSTI]

    HANDLING FRESH FISH REFRIGERATION OF FISH - PART 2 UNITED STATES DEPARTMENT OF THE INTERIOR FISH 428 Washington 25, D, C. December 1956 REFRIGERATION OF FISH - PART TWO HANDLING FRESH FISH By Charles in a series of five on "Refrigeration of Fish." Titles of the other four leaflets are: - 38 - 84 Part 1

  8. REFRIGERATION OF FISH PART 5 DISTRIBUTION AND MARKETING

    E-Print Network [OSTI]

    REFRIGERATION OF FISH· PART 5 DISTRIBUTION AND MARKETING OF FROZEN FISHERY PRODUCTS UNITED STATES in a series of five on "Refrigeration of Fish." Titles of the other four leaflets are: Part 1 (Fishery Leaflet., and edited by Joseph W. Slavin, Refrigeration Engineer, Fishery Technological Laborator,y, East Boston

  9. A dilution refrigerator insert for standard ILL cryostats K. Neumaier

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    773 A dilution refrigerator insert for standard ILL cryostats K. Neumaier WMI Garching, F.R.G. A-1.2 K) the sample stick was replaced by a dilution refrigerator insert with a minimum no temperatures, we replaced the sample stick by a dilution refrigerator insert (Fig. 1). The large cooling power

  10. page 1 of 4 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    page 1 of 4 TkF Värmeteknik Refrigeration / Kylteknik Ron Zevenhoven, prof. Exam 240107 4 questions with methylchloride (CH3Cl, R-40) as refrigerant. The evaporator operates at Te = -20 °C and exchanges heat the mixture quality x for state 5 in the T,s diagram. (2 p.) b. How much heat qin (kJ/kg refrigerant) is taken

  11. Development of a thermoacoustic travelling-wave refrigerator

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Development of a thermoacoustic travelling-wave refrigerator M. Pierensa , J.-P. Thermeaua , T. Le, a thermoacoustic travelling-wave refrigerator has been developed. Its performances are presented in this paper the refrigerator, its instrumentation and its experimental test bench. Finally we give the results obtained from

  12. CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CHARACTERIZATION OF MIXED CO2-TBPB HYDRATE FOR REFRIGERATION APPLICATIONS Pascal Clain , Anthony storage and distribution in refrigeration applications. Previous studies show that these hydrates are able.s] INTRODUCTION Secondary refrigeration is a method using a neutral fluid for cold distribution in order

  13. 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

  14. DEVELOPMENT OF A HIGH EFFICIENCY, AUTOMATIC DEFROSTING REFRIGERATOR-FREEZER

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;DEVELOPMENT OF A HIGH EFFICIENCY, AUTOMATIC DEFROSTING REFRIGERATOR-FREEZER Richard F. Topping-efficient refrigerator- freezer prototype involving the Department of Energy's Oak Ridge National Laboratory, Arthur D. Little, Inc., and Amana Refrigeration, Inc. The project was initiated in 1977 by Oak Ridge National

  15. page 1 of 5 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    page 1 of 5 TkF Värmeteknik Refrigeration / Kylteknik Ron Zevenhoven, prof. Exam 17-12-2008 4 devices. 209. An ideal vapour-compression cycle heat pump with R-134a as the working fluid (refrigerant within 1 hour, calculate the minimum cooling/freezing capacity of the refrigerator (W) and the time

  16. Optimal Performance of a Reciprocating Demagnetization Quantum Refrigerators

    E-Print Network [OSTI]

    Kosloff, Ronnie

    Optimal Performance of a Reciprocating Demagnetization Quantum Refrigerators Ronnie Kosloff A reciprocating quantum refrigerator is studied with the purpose of determining the limitations of cooling. The refrigerator is based on an Otto cycle where the working medium is an interacting spin system with an energy

  17. page 1 of 4 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    page 1 of 4 TkF Värmeteknik Refrigeration / Kylteknik Ron Zevenhoven, prof. Exam 280307 4 questions devices. 205. A vapour-compression system that uses refrigerant R-134a must be tested to determine optimal; the mass flow of refrigerant is 0.05 kg/s. a. Determine the values for evaporator and condenser heat loads

  18. Embedded Smart Controller for an Industrial Reefer Refrigeration1

    E-Print Network [OSTI]

    Reznik, Leon

    Embedded Smart Controller for an Industrial Reefer Refrigeration1 Leon Reznik and Shane Spiteri refrigeration control. The goal of this project is twofold: to design an efficient and economically feasible to a regulation problem in reefer refrigeration systems. By an application of the Motorola HC12 MCU with its

  19. Method and apparatus for de-superheating refrigerant

    DOE Patents [OSTI]

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

    1997-11-25T23:59:59.000Z

    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.

  20. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect (OSTI)

    Calm, James M.

    2000-09-30T23:59:59.000Z

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  1. Quantum bath refrigeration towards absolute zero: unattainability principle challenged

    E-Print Network [OSTI]

    Michal Kolá?; David Gelbwaser-Klimovsky; Robert Alicki; Gershon Kurizki

    2012-08-05T23:59:59.000Z

    A minimal model of a quantum refrigerator (QR), i.e. a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards the absolute zero (T=0). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as T->0 for certain realistic quantized baths, e.g. phonons in strongly disordered media (fractons) or quantized spin-waves in ferromagnets (magnons). This result challenges Nernst's third-law formulation known as the unattainability principle.

  2. How small can thermal machines be? The smallest possible refrigerator

    E-Print Network [OSTI]

    Noah Linden; Sandu Popescu; Paul Skrzypczyk

    2010-08-31T23:59:59.000Z

    We investigate the fundamental dimensional limits to thermodynamic machines. In particular we show that it is possible to construct self-contained refrigerators (i.e. not requiring external sources of work) consisting of only a small number of qubits and/or qutrits. We present three different models, consisting of two qubits, a qubit and a qutrit with nearest-neighbour interactions, and a single qutrit respectively. We then investigate fundamental limits to their performance; in particular we show that it is possible to cool towards absolute zero.

  3. Helium refrigeration considerations for cryomodule design

    SciTech Connect (OSTI)

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

    2014-01-29T23:59:59.000Z

    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.

  4. Infrared and ultraviolet problem for the Nelson model with variable coefficients

    E-Print Network [OSTI]

    Infrared and ultraviolet problem for the Nelson model with variable coefficients C. G´erard,1 , F of the Hamiltonian in the presence of the infrared problem, i.e. assuming that the boson mass tends to 0 at infinity state one usually speaks of the infrared problem or infrared divergence. The infrared problem arises

  5. Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    control 1 Introduction. Modern automobile engines must satisfy the challenging and often con icting goals) 248-3611, Phone: (313) 322-1977 y Control Systems Laboratory, Department of Electrical EngineeringControl-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine A. G

  6. Keller's model Variable energy recreation Bounding the derivative of f Optimization of running strategies based on

    E-Print Network [OSTI]

    Boyer, Edmond

    strategies based on anaerobic energy and variations of velocity J. Fr´ed´eric Bonnans Inria-Saclay and CMAP of running strategies hal-01024231,version1-15Jul2014 #12;Keller's model Variable energy recreation Bounding.F. Bonnans, Optimization of running strategies based on anaerobic energy and variations of velocity. SIAM J

  7. Journal of Hydrology 161 (1994)91-108 Variably saturated modeling of transient drainage: sensitivity

    E-Print Network [OSTI]

    Clement, Prabhakar

    Journal of Hydrology ELSEVIER [1] Journal of Hydrology 161 (1994)91-108 Variably saturated modeling-1694(94)02509-A #12;92 W.R. Wise et al. / Journal of Hydrology 161 (1994) 91-108 transient unconfined flow through

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

    E-Print Network [OSTI]

    Wang, Jin

    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 of the normal distribution for modeling of daily changes in market variables with fatter-than-normal tails

  9. Model simulation of Greenland Sea upper-ocean variability S. Hakkinen,1

    E-Print Network [OSTI]

    Zhang, Jinlun

    Model simulation of Greenland Sea upper-ocean variability S. Ha¨kkinen,1 F. Dupont,2 M. Karcher,3-ocean water masses coincides with periods of intense deep-water formation in the Greenland Sea. This paper-ocean properties observed in the Greenland Sea, including very dense, saline water masses in the 1950s, 1960s

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

    E-Print Network [OSTI]

    Lek, Sovan

    , 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

  11. Nonparametric Variable Selection for Predictive Models and Subpopulations in Clinical Trials

    E-Print Network [OSTI]

    Xie, Jun

    Introduction In most clinical trials, there is much heterogeneity among individual outcomes and the treat- mentNonparametric Variable Selection for Predictive Models and Subpopulations in Clinical Trials Jingyi, IN 47907 Abstract Most clinical trials have heterogeneous treatment effect among patient individuals

  12. Geostatistical modeling of the spatial variability of arsenic in groundwater of southeast Michigan

    E-Print Network [OSTI]

    Geostatistical modeling of the spatial variability of arsenic in groundwater of southeast Michigan in groundwater of southeast Michigan, accounting for arsenic data collected at private residential wells and the hydrogeochemistry of the area. The arsenic data set, which was provided by the Michigan Department of Environmental

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

    SciTech Connect (OSTI)

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

    1995-03-01T23:59:59.000Z

    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.

  14. Distinguished rheological models in the framework of a thermodynamical internal variable theory

    E-Print Network [OSTI]

    Asszonyi, Cs; Ván, P

    2014-01-01T23:59:59.000Z

    We present and analyze a thermodynamical theory of rheology with single internal variable. The universality of the model is ensured as long as the mesoscopic and/or microscopic background processes satisfy the applied thermodynamical principles, which are the second law, the basic balances and the existence of an additional-tensorial-state variable. The resulting model, which we suggest to call the Kluitenberg-Verh\\'as body, is the Poynting-Thomson-Zener body with an additional inertial element, or, in other words, is the extension of Jeffreys model to solids. We argue that this Kluitenberg-Verh\\'as body is the natural thermodynamical building block of rheology. An important feature of the presented methodology is that nontrivial inequality-type restrictions arise for the four parameters of the model. We compare these conditions and other aspects to those of other known thermodynamical approaches, like Extended Irreversible Thermodynamics or the original theory of Kluitenberg.

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

    DOE Patents [OSTI]

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

    2006-02-07T23:59:59.000Z

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

  16. T Tauri variability in the context of the beat-frequency model

    E-Print Network [OSTI]

    K. W. Smith; G. F. Lewis; I. A. Bonnell

    1995-08-17T23:59:59.000Z

    We examine the implications of a beat frequency modulated model of T Tauri accretion. In particular we show that measurements of the variability of accretion generated lines can be used in conjunction with existing photometry to obtain a measurement of the underlying photospheric and disc flux. This provides an independent way of checking spectral energy distribution modelling. In addition, we show how spectroscopy of T Tauri stars can reveal the inclination angle between the magnetic axis and the plane of the disc.

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

    E-Print Network [OSTI]

    Kazachkov, Ivan

    PhD student in Energy Technology, specifically in Commercial refrigeration systems with CO2 as refrigerant The School of Industrial Engineering and Management at the Royal Institute of Technology seeks a PhD student in Energy Technology, specifically Commercial refrigeration systems with CO2

  18. 2014-04-10 Issuance: Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers; Final Rule

    Broader source: Energy.gov [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.

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

    SciTech Connect (OSTI)

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

    1995-01-01T23:59:59.000Z

    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.

  20. Waste Heat Recapture from Supermarket Refrigeration Systems

    SciTech Connect (OSTI)

    Fricke, Brian A [ORNL

    2011-11-01T23:59:59.000Z

    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.

  1. Ground Loops for Heat Pumps and Refrigeration 

    E-Print Network [OSTI]

    Braud, H. J.

    1986-01-01T23:59:59.000Z

    Ground loops are used for water source heat pumps. Refrigeration can be put on a ground loop. Water-cooled condensing units are more efficient than air-cooled, and they can be put indoors. Indoor location makes piping for desuperheater hot water...

  2. Covered Product Category: Refrigerated Beverage Vending Machines

    Broader source: Energy.gov [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.

  3. Alternative Refrigerants for Building Air Conditioning

    E-Print Network [OSTI]

    Bivens, D. B.

    1996-01-01T23:59:59.000Z

    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...

  4. Ground Loops for Heat Pumps and Refrigeration

    E-Print Network [OSTI]

    Braud, H. J.

    1986-01-01T23:59:59.000Z

    Ground loops are used for water source heat pumps. Refrigeration can be put on a ground loop. Water-cooled condensing units are more efficient than air-cooled, and they can be put indoors. Indoor location makes piping for desuperheater hot water...

  5. Dilution cycle control for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01T23:59:59.000Z

    A dilution cycle control system for an absorption refrigeration system is disclosed. The control system includes a time delay relay for sensing shutdown of the absorption refrigeration system and for generating a control signal only after expiration of a preselected time period measured from the sensed shutdown of the absorption refrigeration system, during which the absorption refrigeration system is not restarted. A dilution cycle for the absorption refrigeration system is initiated in response to generation of a control signal by the time delay relay. This control system is particularly suitable for use with an absorption refrigeration system which is frequently cycled on and off since the time delay provided by the control system prevents needless dilution of the absorption refrigeration system when the system is turned off for only a short period of time and then is turned back on.

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

    SciTech Connect (OSTI)

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

    1990-01-01T23:59:59.000Z

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

  7. IEA Annex 26: Advanced Supermarket Refrigeration/Heat Recovery Systems

    SciTech Connect (OSTI)

    Baxter, VAN

    2003-05-19T23:59:59.000Z

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case has its own refrigeration unit; low-charge direct expansion--similar to conventional multiplex refrigeration systems but with improved controls to limit charge. Means to integrate store HVAC systems for space heating/cooling with the refrigeration system have been investigated as well. One approach is to use heat pumps to recover refrigeration waste heat and raise it to a sufficient level to provide for store heating needs. Another involves use of combined heating and power (CHP) or combined cooling, heating, and power (CCHP) systems to integrate the refrigeration, HVAC, and power services in stores. Other methods including direct recovery of refrigeration reject heat for space and water heating have also been examined.

  8. Models of the Time Variability of BHC: Light Curves, PSD, Lags

    E-Print Network [OSTI]

    Demosthenes Kazanas

    2000-01-13T23:59:59.000Z

    We present a model for the aperiodic variablity of accreting Black Hole Candidates (BHC) along with model light curves. According to the model this variability is the combined outcome of random (Poisson) injection of soft photons near the center of an extended {\\sl inhomogeneous} distribution of hot electrons (similar to those advocated by the ADAF or ADIOS flows) and the stochastic nature of Compton scattering which converts these soft photons into the observed high energy radiation. Thus, the timing properties (PSD, lags, coherence) of the BHC light curves reflect, to a large extent, the properties of the scattering medium (which in this approximation acts as a combination of a {\\sl linear} amplifier/filter) and they can be used to probe its structure, most notably the density profile of the scattering medium. The model accounts well for the observed PSDs and lags and also the reduction in the RMS variability and the increase in the characteristic PSD frequencies with increasing source luminosity. The electron density profiles obtained to date are consistent mainly with those of ADIOS but also with pure ADAF flows.

  9. The German Vowel System The Control of Token-to-Token Variability: an Experimental and Modeling Study

    E-Print Network [OSTI]

    The German Vowel System The Control of Token-to-Token Variability: an Experimental and Modeling to the motor commands (Modeling) DATA ACQUISITION AND PROCESSING Articulatory data consisted of simultaneous MEASURED ARTICULATORY VARIABILITY General trends for the majority of cases: For low vowels (see left panels

  10. Model Based Control of Refrigeration Systems

    E-Print Network [OSTI]

    Lars Finn; Sloth Larsen; Central R

    2005-01-01T23:59:59.000Z

    Thybo has supervised the work. I would especially like to express my gratitude to my good friend, dive mate, college and supervisor Claus Thybo, for his invaluable help, support and inspiration. His guidance and support has truly been ideal. Without his presence this project would not have been at all and it wouldn’t have been so enjoyable. I would like to thank Jakob Stoustrup for sharing of his profound knowledge within control theory, that has improved the acad-emic level of this thesis. Moreover I would like to thank Henrik Rasmussen, who has more than a lifetimes experience within application of control theory. His sincere and eager interest in my work has truly been a source of inspiration. I would like to thank Professor Manfred Morari for giving me the opportunity to stay at the Automatic Control Laboratory, ETH Zürich and for giving me valuable guidance while I was there. I was amazed by the unique scientific milieu and the high academic level there. I would especially like to thank Tobias Geyer, who contributed with many ideas and a lot of help, while I was at the ETH. I would furthermore like to thank him for taking of his valuable time at the ending of his Ph.D.-study to come and visit Danfoss

  11. An optimized magnet for magnetic refrigeration

    E-Print Network [OSTI]

    Bjørk, R; Smith, A; Christensen, D V; Pryds, N

    2014-01-01T23:59:59.000Z

    A magnet designed for use in a magnetic refrigeration device is presented. The magnet is designed by applying two general schemes for improving a magnet design to a concentric Halbach cylinder magnet design and dimensioning and segmenting this design in an optimum way followed by the construction of the actual magnet. The final design generates a peak value of 1.24 T, an average flux density of 0.9 T in a volume of 2 L using only 7.3 L of magnet, and has an average low flux density of 0.08 T also in a 2 L volume. The working point of all the permanent magnet blocks in the design is very close to the maximum energy density. The final design is characterized in terms of a performance parameter, and it is shown that it is one of the best performing magnet designs published for magnetic refrigeration.

  12. Numerical investigation of high-pressure combustion in rocket engines using Flamelet/Progress-variable models

    E-Print Network [OSTI]

    Coclite, A; De Palma, P; Pascazio, G

    2015-01-01T23:59:59.000Z

    The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined ...

  13. Tapered pulse tube for pulse tube refrigerators

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

    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.

  14. Method of reducing chlorofluorocarbon refrigerant emissons to the atmosphere

    DOE Patents [OSTI]

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

    1990-01-01T23:59:59.000Z

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

  15. A small quantum absorption refrigerator with reversed couplings

    E-Print Network [OSTI]

    Ralph Silva; Paul Skrzypczyk; Nicolas Brunner

    2015-04-14T23:59:59.000Z

    Small quantum absorption refrigerators have recently attracted renewed attention. Here we present a missing design of a two-qubit fridge, the main feature of which is that one of the two machine qubits is itself maintained at a temperature colder than the cold bath. This is achieved by 'reversing' the couplings to the baths compared to previous designs, where only a transition is maintained cold. We characterize the working regime and the efficiency of the fridge. We demonstrate the soundness of the model by deriving and solving a master equation. Finally, we discuss the performance of the fridge, in particular the heat current extracted from the cold bath. We show that our model performs comparably to the standard three-level quantum fridge, and thus appears appealing for possible implementations of nano thermal machines.

  16. Building Qualitative Models of Thermodynamic Processes

    E-Print Network [OSTI]

    Forbus, Kenneth D.

    of typical fluid and thermal systems, such as refrigerators and power plants . We use explicit modeling simplified versions of a refrigerator, a steam plant, and a thermal control system . Finally, we describe a Refrigerator 66 5 .5 Modeling a shipboard propulsion plant 70 5 .6 Summary of Examples 70 6 Discussion 72 7

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

    SciTech Connect (OSTI)

    None

    2010-09-01T23:59:59.000Z

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

  18. Hydrophilic structures for condensation management in refrigerator appliances

    DOE Patents [OSTI]

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

    2014-10-21T23:59:59.000Z

    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.

  19. Process Options for Nominal 2-K Helium Refrigeration System Designs

    SciTech Connect (OSTI)

    Peter Knudsen, Venkatarao Ganni

    2012-07-01T23:59:59.000Z

    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).

  20. Optimal Design Refrigeration System for a Mucilage Glue Fiber Factory

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-4 Optimal Design Refrigeration System for a Mucilage Glue Fiber Factory Chaoyi Tan Jianlong Liu Fennan Tang Yang Liu Hunan University of Technology... fiber ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency Vol.IV-1-4 2. REFRIGERATION SYSTEM SUPERIOR DESIGN PROPOSAL IN MUCILAGE GLUE FIBER FACTORY 2.1 Refrigeration system superior design proposal in mucilage glue fiber factory...

  1. TRANSFUSION MEDICINE Desialylation accelerates platelet clearance after refrigeration and initiates GPIb

    E-Print Network [OSTI]

    von Andrian, Ulrich H.

    TRANSFUSION MEDICINE Desialylation accelerates platelet clearance after refrigeration and initiates, Boston, MA When refrigerated platelets are rewarmed, they secrete active sialidases, including factor receptor (VWFR), specifically the GPIb subunit. The recovery and circulation of refrigerated

  2. Design Principles and Performance Metrics for Magnetic Refrigerators Operating Near Room Temperature

    E-Print Network [OSTI]

    Victoria, University of

    Design Principles and Performance Metrics for Magnetic Refrigerators Operating Near Room Principles and Performance Metrics for Magnetic Refrigerators Operating Near Room Temperature by Daniel Sean decade, active magnetic regenerative (AMR) refrigeration technology has progressed towards commercial

  3. The effect of distributed exchange parameters on magnetocaloric refrigeration capacity in amorphous and nanocomposite materials

    E-Print Network [OSTI]

    McHenry, Michael E.

    of Physics. Related Articles High performance magnetocaloric perovskites for magnetic refrigeration Appl energy on interatomic spacing. The magnetic entropy curve revealed extra broadening with a refrigerationThe effect of distributed exchange parameters on magnetocaloric refrigeration capacity in amorphous

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

    DOE Patents [OSTI]

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

    1998-04-28T23:59:59.000Z

    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.

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

    DOE Patents [OSTI]

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

    1998-04-28T23:59:59.000Z

    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.

  6. arti refrigerant database: Topics by E-print Network

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

    textbooks: Database Systems Alechina, Natasha 86 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  7. Mexico Sectoral Study on Climate and Refrigeration Technology...

    Open Energy Info (EERE)

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

  8. Energy Efficient Refrigerators Incentive Program Options for South Africa

    E-Print Network [OSTI]

    Can, Stephane de la Rue du

    2014-01-01T23:59:59.000Z

    Covary, Unlimited Energy, South Africa and Paul Waide, WaideCA 94720 Unlimited Energy 2 South Africa Waide Strategicof refrigerator energy efficiency for South Africa. The

  9. New Refrigerant Boosts Energy Efficiency of Supermarket Display...

    Energy Savers [EERE]

    Solstice N40 offer supermarkets an easy solution to reduce their refrigeration system's electricity consumption, save energy, and cut greenhouse gas emissions. The Building...

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

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

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

  11. 2015-03-26: Miscellaneous Refrigeration Products; Notice of Intent...

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

    Miscellaneous Refrigeration Products, as issued by the Deputy Assistant Secretary for Energy Efficiency on March 26, 2015. Though it is not intended or expected, should any...

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

    Energy Savers [EERE]

    fluids along with thermophysical properties that yield high energy efficiency in refrigeration equipment. NIST cannot make the determination of the optimal fluid for any given...

  13. Geothermal: Sponsored by OSTI -- Chapter 13. Absorption Refrigeration

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

    3. Absorption Refrigeration Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us HomeBasic Search About Publications Advanced Search New Hot Docs News...

  14. active magnetic refrigerator: Topics by E-print Network

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

    is active magnetic regenerator (AMR) refrigeration. This technology relies on solid materials exhibiting the magnetocaloric effect, (more) Dikeos, John 2006-01-01 2 Design...

  15. Helium Refrigerator Design for Pulsed Heat Load in Tokamaks

    SciTech Connect (OSTI)

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

    2006-04-27T23:59:59.000Z

    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.

  16. Energy Efficiency Standards for Refrigerators in Brazil: A Methodology...

    Open Energy Info (EERE)

    Impact Evaluation Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Energy Efficiency Standards for Refrigerators in Brazil: A Methodology for Impact Evaluation Focus...

  17. Economizer refrigeration cycle space heating and cooling system and process

    DOE Patents [OSTI]

    Jardine, D.M.

    1983-03-22T23:59:59.000Z

    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.

  18. Economizer refrigeration cycle space heating and cooling system and process

    DOE Patents [OSTI]

    Jardine, Douglas M. (Colorado Springs, CO)

    1983-01-01T23:59:59.000Z

    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.

  19. The response of glaciers to intrinsic climate variability: observations and models of late-Holocene variations in the

    E-Print Network [OSTI]

    Roe, Gerard

    The response of glaciers to intrinsic climate variability: observations and models of late glacier variations due to natural climate variability and those due to true climate change is crucial for the interpretation and attribution of past glacier changes, and for the expectations of future changes. We explore

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

    SciTech Connect (OSTI)

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

    1998-09-01T23:59:59.000Z

    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.

  1. Rapid Oscillatory quintessence with variable equation of state parameter in non minimal derivative coupling model

    E-Print Network [OSTI]

    H. Mohseni Sadjadi

    2014-10-07T23:59:59.000Z

    The rapid oscillating scalar field is considered as the quintessence in the framework of nonminimal kinetic coupling model. The scalar field behaves like a perfect fluid with a variable equation of state parameter which can be expressed as a function of the Hubble parameter. This feature enables us to study its evolution via continuity equation. The scalar field may behave as dark energy in the present epoch, while it behaves like dark matter in the future. This characteristic allows the occurrence of a decelerated expansion after the present acceleration, without invoking any interaction. The model is also studied in the presence of an interaction between dark sectors alleviating the coincidence problem. The stability of the model is investigated and the stable attractor solutions are studied.

  2. Autoregressive modeling with state-space embedding vectors for damage detection under operational and environmental variability

    SciTech Connect (OSTI)

    Farrar, Charles [Los Alamos National Laboratory; Figueiredo, Eloi [UNIV OF PORTO; Todd, Michael [UCSD; Flynn, Eric [UCSD

    2010-01-01T23:59:59.000Z

    A nonlinear time series approach is presented to detect damage in systems by using a state-space reconstruction to infer the geometrical structure of a deterministic dynamical system from observed time series response at multiple locations. The unique contribution of this approach is using a Multivariate Autoregressive (MAR) model of a baseline condition to predict the state space, where the model encodes the embedding vectors rather than scalar time series. A hypothesis test is established that the MAR model will fail to predict future response if damage is present in the test condition, and this test is investigated for robustness in the context of operational and environmental variability. The applicability of this approach is demonstrated using acceleration time series from a base-excited 3-story frame structure.

  3. Floating loop method for cooling integrated motors and inverters using hot liquid refrigerant

    DOE Patents [OSTI]

    Hsu, John S.; Ayers, Curtis W.; Coomer, Chester; Marlino, Laura D.

    2007-03-20T23:59:59.000Z

    A method for cooling vehicle components using the vehicle air conditioning system comprising the steps of: tapping the hot liquid refrigerant of said air conditioning system, flooding a heat exchanger in the vehicle component with said hot liquid refrigerant, evaporating said hot liquid refrigerant into hot vapor refrigerant using the heat from said vehicle component, and returning said hot vapor refrigerant to the hot vapor refrigerant line in said vehicle air conditioning system.

  4. Reliability Design and Case Study of a Refrigerator Compressor Subjected to Repetitive Loads, International Journal of Refrigeration

    E-Print Network [OSTI]

    Woo, S.; O'Neal, D.L.; Pecht, M.

    A newly designed crankshaft of a compressor for a side-by-side (SBS) refrigerator was studied. Using mass and energy conservation balances, a variety of compressor loads typically found in a refrigeration cycle were analyzed. The laboratory failure... vis-a´-vis de la fiabilite´ et e´tude de casArticle history: Received 18 March 2008 Received in revised form 6 May 2008 Accepted 21 July 2008 Published online 31 July 2008 Keywords: Refrigeration system Compression system Reciprocating compressor...

  5. Fourier-phase analysis of the orbiting bright-spot model for AGN variability

    E-Print Network [OSTI]

    V. Karas

    1997-01-13T23:59:59.000Z

    Fourier power spectra and phases of a signal from a large number of radiating sources orbiting around a black hole are investigated. It is assumed that the individual sources (bright spots) are located in an accretion disc and their lifetime exceeds the corresponding orbital period. This model is relevant for the short-time X-ray variability of active galactic nuclei. Previous works on this subject were mostly concentrated on temporal characteristics and power spectra of observed light curves. In our present contribution, Fourier phases are brought into consideration and studied systematically for a broad range of input parameters. In particular, conditions for the phase coherence are discussed. It is shown that one can discriminate between the two classes of models which are currently under consideration--orbital motion of a large number of sources versus short-lived independent flares--although parameters of the model are not completely arbitrary. It is also shown that predicted power spectra depend rather strongly on the spot distribution across the disk surface. We conclude that the orbital motion of the spots cannot be the only reason for the source fluctuations, but it certainly influences observational properties of the source intrinsic variability.

  6. Collective coordinate variable for soliton-potential system in sine-Gordon model

    E-Print Network [OSTI]

    Kurosh Javidan

    2009-10-16T23:59:59.000Z

    A Collective coordinate variable for adding a space dependent potential to the sine-Gordon model is presented. Interaction of solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the characters of interaction are derived analytically. We will find that the behaviour of a solitonic solution is like a point particle which is moved under the influence of a complicated effective potential. The effective potential is a function of the field initial conditions and also parameters of added potential.

  7. Plate Fin Heat Exchanger Model with Axial Conduction and Variable Properties

    SciTech Connect (OSTI)

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

    2011-06-10T23:59:59.000Z

    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.

  8. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-10-31T23:59:59.000Z

    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.

  9. Feasibility of Solar-Assisted Refrigerated Transport in Australia

    E-Print Network [OSTI]

    the fea- sibility of using photovoltaics to minimise the use of diesel generators in refrigerated) modules to minimise the use of diesel generation in refrigerated transport. Sub- sequently, UK supermarket, to fail over to the diesel generator when electrical power is cut. The major supermarket chains trading

  10. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

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

    1985-10-25T23:59:59.000Z

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

  11. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

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

    1987-01-01T23:59:59.000Z

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

  12. Simplified Modeling of Active Magnetic Regenerators Thomas Burdyny

    E-Print Network [OSTI]

    Victoria, University of

    , this technology uses the magnetization and demagnetization of environmentally neutral solid refrigerants ...............................................................................................................1 1.2 Magnetic RefrigerationSimplified Modeling of Active Magnetic Regenerators by Thomas Burdyny BEng., University of Victoria

  13. Numerical modelling and analysis of a room temperature magnetic

    E-Print Network [OSTI]

    Numerical modelling and analysis of a room temperature magnetic refrigeration system Thomas Frank and analysis of a room temperature magnetic refrigeration system Department: Fuel Cells and Solid State-dimensional mathematical model of an Active Magnetic Regenerator (AMR) system which is used for magnetic refrigeration

  14. Detection probability enhancement as a natural feature of Local Hidden Variable models (and Quantum Mechanics too?)

    E-Print Network [OSTI]

    Rodriguez, David

    2011-01-01T23:59:59.000Z

    Experimental tests of Bell inequalities often require supplementary assumptions, one of the usual ones being the "no-enhancement" assumption. Here we show how an already well known Local Hidden Variables (LHV) model for the Clauser-Horne-Shimony-Holt inequality, when extended to account for the probabilities of detection when the polarizers are removed (such as how it would need to be done in a test of the Clauser-Horne inequality), gives rise, as the most natural feature, to the so-called "enhancement" (breaking of the no-enhancement assumption formulated by Clauser and Horne themselves for the operational expression of their inequality). Aside from exposing that key role of enhancement, our work is useful (at least in our case it has been) to gain understanding on some other known results. We also add some comments that we think may be thought-provoking.

  15. PhD student in Energy Technology, specifically in New low GWP refrigerants

    E-Print Network [OSTI]

    Kazachkov, Ivan

    PhD student in Energy Technology, specifically in New low GWP refrigerants The School of Industrial, specifically New low GWP refrigerants. KTH is the largest technical university in Sweden. Education and Refrigeration The Division of Applied Thermodynamics and Refrigeration, part of the Department of Energy

  16. Refrigerated Warehouses Introduction Page 8-1 2008 Nonresidential Compliance Manual August 2009

    E-Print Network [OSTI]

    Refrigerated Warehouses ­ Introduction Page 8-1 2008 Nonresidential Compliance Manual August 2009 8 Refrigerated Warehouses 8.1 Introduction This section of the nonresidential compliance manual addresses refrigerated warehouses. Since regulation of refrigerated warehouses is new for the 2008 Standards (§126

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    2007-01-01T23:59:59.000Z

    Computers and Chemical Engineering 31 (2007) 1590­1601 Optimal operation of simple refrigeration February 2007 Abstract The paper focuses on operation of simple refrigeration cycles and considers refrigeration cycle and the other is a trans-critical CO2 refrigeration cycle. There is no fundamental

  18. Development and Validation of an Active Magnetic Regenerator Refrigeration Cycle Simulation

    E-Print Network [OSTI]

    Victoria, University of

    Development and Validation of an Active Magnetic Regenerator Refrigeration Cycle Simulation by John of an Active Magnetic Regenerator Refrigeration Cycle Simulation by John Dikeos B.Sc., Queen's University, 2003 for refrigeration and gas liquefaction is active magnetic regenerator (AMR) refrigeration. This technology relies

  19. Computer modeling of arc welds to predict effects of critical variables on weld penetration

    SciTech Connect (OSTI)

    Zacharia, T.; David, S.A.

    1991-01-01T23:59:59.000Z

    In recent years, there have been several attempts to study the effect of critical variables on welding by computational modeling. It is widely recognized that temperature distributions and weld pool shapes are keys to quality weldments. It would be very useful to obtain relevant information about the thermal cycle experienced by the weld metal, the size and shape of the weld pool, and the local solidification rates, temperature distributions in the heat-affected zone (HAZ), and associated phase transformations. The solution of moving boundary problems, such as weld pool fluid flow and heat transfer, that involve melting and/or solidification is inherently difficult because the location of the solid-liquid interface is not known a priori and must be obtained as a part of the solution. Because of non-linearity of the governing equations, exact analytical solutions can be obtained only for a limited number of idealized cases. Therefore, considerable interest has been directed toward the use of numerical methods to obtain time-dependant solutions for theoretical models that describe the welding process. Numerical methods can be employed to predict the transient development of the weld pool as an integral part of the overall heat transfer conditions. The structure of the model allows each phenomenon to be addressed individually, thereby gaining more insight into their competing interactions. 19 refs., 6 figs., 1 tab.

  20. Combined refrigeration system with a liquid pre-cooling heat exchanger

    DOE Patents [OSTI]

    Gaul, Christopher J.

    2003-07-01T23:59:59.000Z

    A compressor-pump unit for use in a vapor-compression refrigeration system is provided. The compressor-pump unit comprises a driving device including a rotatable shaft. A compressor is coupled with a first portion of the shaft for compressing gaseous refrigerant within the vapor-compression refrigeration system. A liquid pump is coupled with a second portion of the shaft for receiving liquid refrigerant having a first pressure and for discharging the received liquid refrigerant at a second pressure with the second pressure being higher than the first pressure by a predetermined amount such that the discharged liquid refrigerant is subcooled. A pre-cooling circuit is connected to the liquid pump with the pre-cooling circuit being exposed to the gaseous refrigerant whereby the gaseous refrigerant absorbs heat from the liquid refrigerant, prior to the liquid refrigerant entering the liquid pump.

  1. Variably Saturated Flow and Multicomponent Biogeochemical Reactive Transport Modeling of a Uranium Bioremediation Field Experiment

    SciTech Connect (OSTI)

    Yabusaki, Steven B.; Fang, Yilin; Williams, Kenneth H.; Murray, Christopher J.; Ward, Anderson L.; Dayvault, Richard; Waichler, Scott R.; Newcomer, Darrell R.; Spane, Frank A.; Long, Philip E.

    2011-11-01T23:59:59.000Z

    Field experiments at a former uranium mill tailings site have identified the potential for stimulating indigenous bacteria to catalyze the conversion of aqueous uranium in the +6 oxidation state to immobile solid-associated uranium in the +4 oxidation state. This effectively removes uranium from solution resulting in groundwater concentrations below actionable standards. Three-dimensional, coupled variably-saturated flow and biogeochemical reactive transport modeling of a 2008 in situ uranium bioremediation field experiment is used to better understand the interplay of transport rates and biogeochemical reaction rates that determine the location and magnitude of key reaction products. A comprehensive reaction network, developed largely through previous 1-D modeling studies, was used to simulate the impacts on uranium behavior of pulsed acetate amendment, seasonal water table variation, spatially-variable physical (hydraulic conductivity, porosity) and geochemical (reactive surface area) material properties. A principal challenge is the mechanistic representation of biologically-mediated terminal electron acceptor process (TEAP) reactions whose products significantly alter geochemical controls on uranium mobility through increases in pH, alkalinity, exchangeable cations, and highly reactive reduction products. In general, these simulations of the 2008 Big Rusty acetate biostimulation field experiment in Rifle, Colorado confirmed previously identified behaviors including (1) initial dominance by iron reducing bacteria that concomitantly reduce aqueous U(VI), (2) sulfate reducing bacteria that become dominant after {approx}30 days and outcompete iron reducers for the acetate electron donor, (3) continuing iron-reducer activity and U(VI) bioreduction during dominantly sulfate reducing conditions, and (4) lower apparent U(VI) removal from groundwater during dominantly sulfate reducing conditions. New knowledge on simultaneously active metal and sulfate reducers has been incorporated into the modeling. In this case, an initially small population of slow growing sulfate reducers is active from the initiation of biostimulation. Three-dimensional, variably saturated flow modeling was used to address impacts of a falling water table during acetate injection. These impacts included a significant reduction in aquifer saturated thickness and isolation of residual reactants and products, as well as unmitigated uranium, in the newly unsaturated vadose zone. High permeability sandy gravel structures resulted in locally high flow rates in the vicinity of injection wells that increased acetate dilution. In downgradient locations, these structures created preferential flow paths for acetate delivery that enhanced local zones of TEAP reactivity and subsidiary reactions. Conversely, smaller transport rates associated with the lower permeability lithofacies (e.g., fine) and vadose zone were shown to limit acetate access and reaction. Once accessed by acetate, however, these same zones limited subsequent acetate dilution and provided longer residence times that resulted in higher concentrations of TEAP products when terminal electron donors and acceptors were not limiting. Finally, facies-based porosity and reactive surface area variations were shown to affect aqueous uranium concentration distributions; however, the ranges were sufficiently small to preserve general trends. Large computer memory and high computational performance were required to simulate the detailed coupled process models for multiple biogeochemical components in highly resolved heterogeneous materials for the 110-day field experiment and 50 days of post-biostimulation behavior. In this case, a highly-scalable subsurface simulator operating on 128 processor cores for 12 hours was used to simulate each realization. An equivalent simulation without parallel processing would have taken 60 days, assuming sufficient memory was available.

  2. Development of Refrigerant Change Indicator and Dirty Air Filter Sensor

    SciTech Connect (OSTI)

    Mei, V.

    2003-06-24T23:59:59.000Z

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

  3. Stellar population models of Lick indices with variable element abundance ratios

    E-Print Network [OSTI]

    Daniel Thomas; Claudia Maraston; Ralf Bender

    2002-11-12T23:59:59.000Z

    We provide the whole set of Lick indices from CN1 to TiO2 of Simple Stellar Population models with, for the first time, variable element abundance ratios, [alpha/Fe]=0.0, 0.3, 0.5, [alpha/Ca]=-0.1, 0.0, 0.2, 0.5, and [alpha/N]=-0.5, 0.0. The models cover ages between 1 and 15 Gyr, metallicities between 1/200 and 3.5 solar. Our models are free from the intrinsic alpha/Fe bias that was imposed by the Milky Way template stars up to now, hence they reflect well-defined alpha/Fe ratios at all metallicities. The models are calibrated with Milky Way globular clusters for which metallicities and alpha/Fe ratios are known from independent spectroscopy of individual stars. The metallicities that we derive from the Lick indices Mgb and Fe5270 are in excellent agreement with the metallicity scale by Zinn & West (1984), and we show that the latter provides total metallicity rather than iron abundance. We can reproduce the relatively strong CN-absorption features CN1 and CN2 of galactic globular clusters with models in which nitrogen is enhanced by a factor three. An enhancement of carbon, instead, would lead to serious inconsistencies with the indices Mg1 and C24668. The calcium sensitive index Ca4227 of globular clusters is well matched by our models with [Ca/Fe]= 0.3, including the metal-rich Bulge clusters NGC 6528 and NGC 6553. From our alpha/Fe enhanced models we infer that the index [MgFe] defined by Gonzalez (1993) is quite independent of alpha/Fe, but still slightly decreases with increasing alpha/Fe. We define a slight modification of this index that is completely independent of alpha/Fe and serves best as a tracer of total metallicity. Searching for blue indices that give similar information as Mgb and Fe, we find that CN1 and Fe4383 may be best suited to estimate alpha/Fe ratios of objects at redshifts z~1. (Abridged)

  4. Refrigerator with a clearance seal compressor

    SciTech Connect (OSTI)

    Holland, N. J.

    1985-09-10T23:59:59.000Z

    In a Stirling refrigeration system in which a displacer is driven in a reciprocating motion within a cold finger by a pressure differential between helium gas in the cold finger and helium gas in a gas spring volume, the reciprocating piston compressor for the working volume has a clearance seal between the working volume and a control volume. The only lubricant in that seal is the helium gas. The mean pressure of the working volume relative to the control volume can be controlled by varying the length of the clearance seal throughout the stroke of the piston. Preferably, the seal is between alumina ceramic sleeves. The clearance seal compressor may also be used in a Gifford-McMahon cycle.

  5. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, Martin S. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    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.

  6. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, M.S.

    1994-10-25T23:59:59.000Z

    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.

  7. Rotating Winds from Accretion Disks in Cataclysmic Variables: Eclipse Modeling of V347 Puppis

    E-Print Network [OSTI]

    Isaac Shlosman; Peter Vitello; Christopher W. Mauche

    1995-11-01T23:59:59.000Z

    We study the eclipsing nova-like variable V347 Pup by matching its UV emission line profiles in and out of eclipse to synthetic lines using a 3D kinematic and radiation transfer model. Our results support the accretion disk origin of winds in non-magnetic CVs as opposite to the WD origin. Our main point concerns the importance of rotation for the UV emission line shapes in such systems. In particular, we show that the narrowing of the UV emission lines in V347 Pup during eclipse can be easily explained by the eclipse of the innermost part of the wind by the secondary and the resulting reduction in the contribution of rotational broadening to the width of the lines. During the eclipse, the residual line flux is very sensitive to the maximal temperature of disk radiation. Good fits for reasonable mass-loss rates have been obtained for maximum disk temperatures of 50,000 degrees. This constraint was imposed either by leveling off the inner disk temperature profiles, in agreement with recent observations of some nova-like objects, or by assuming that the accretion disk does not extend to the surface of the white dwarf, in which case V347 up would be an intermediate polar. In anticipation of high-speed spectrophotometry of CVs by the HST, we provide numerical model of a time-resolved eclipse of V347 Pup or similar such system to be verified by future observations.

  8. Comprehensive Compressor Calorimeter Testing of Lower-GWP Alternative Refrigerants for Heat Pump and Medium Temperature Refrigeration Applications

    SciTech Connect (OSTI)

    Shrestha, Som S [ORNL] [ORNL; Sharma, Vishaldeep [ORNL] [ORNL; Abdelaziz, Omar [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    In response to environmental concerns raised by the use of refrigerants with high Global Warming Potential (GWP), the Air-Conditioning, Heating, and Refrigeration Institute (AHRI) has launched an industry-wide cooperative research program, referred to as the Low-GWP Alternative Refrigerants Evaluation Program (AREP), to identify and evaluate promising alternative refrigerants for major product categories. This paper reports one of the Oak Ridge National Laboratory (ORNL) contributions to AREP. It compares performance of alternative refrigerants to that of R-410A and R-404A for heat pump and medium temperature applications, respectively. The alternatives reported in this paper are: R-32, DR-5, and L-41a for R-410A and ARM-31a, D2Y-65, L-40, and a mixture of R-32 and R-134a for R-404A. All performance comparison tests were conducted using scroll compressors of ~1.85 tons (6.5 kW) cooling capacity. Tests were conducted over a range of combinations of saturation suction and saturation discharge temperatures for both compressors. The tests showed that, in general, energy efficiency ratio (EER) and cooling capacity of R-410A alternative refrigerants were slightly lower than that of the baseline refrigerant with a moderate increases in discharge temperature. On the other hand, R-404A alternative refrigerants showed relative performance dependence on saturation suction and saturation discharge temperatures and larger increases in discharge temperature than for the R-410A alternatives. This paper summarizes the relative performance of all alternative refrigerants compared to their respective baseline.

  9. absorption refrigerator system: Topics by E-print Network

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

    Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L. 12 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  10. amr refrigeration cycle: Topics by E-print Network

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

    Banerjee; Ralph E. Pudritz; Lindsay Holmes 2004-08-15 112 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  11. adsorption refrigeration system: Topics by E-print Network

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

    J.; Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L. 8 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  12. absorption refrigeration system: Topics by E-print Network

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

    Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L. 12 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  13. adsorption refrigerator powered: Topics by E-print Network

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

    cycle T I. Jinshah B S; Ajith Krishnan R; Eep V S 71 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  14. absorption refrigeration systems: Topics by E-print Network

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

    Sharp, M. K.; Case, M. E.; Gregory, R. W.; Case, P. L. 12 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  15. authority refrigerator replacement: Topics by E-print Network

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

    videos. Unlike prior work, it does not ... Dale, Kevin 52 Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems Texas A&M University - TxSpace Summary:...

  16. Reliability of Heat Pumps Containing R410-A Refrigerant

    E-Print Network [OSTI]

    McJimsey, B. A.; Cawley, D.

    1998-01-01T23:59:59.000Z

    on alternate refrigerants. One major manufacturer announced a formation of black smudge on internal surfaces of field trial units using HFCs. Several causes were suggested but none were published. Reports of capillary tube plugging were wide spread. Polyol...

  17. Removing Odors from Refrigerators and Freezers after Food has Spoiled

    E-Print Network [OSTI]

    FCS Project Team - FDRM UNIT

    2005-09-30T23:59:59.000Z

    If food has spoiled in a refrigerator or freezer because of a power outage or some other reason, undesirable odors can result. This publication explains how to eliminate odors from these appliances....

  18. Availability of refrigerants for heat pumps in Europe

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    grids Smart cities #12;8 Residential HPs Refrigerants Use of aero-geo- +hydrothermal renewable energy cooling and heating Residential Future: Heating of electric cars and cooling the batteries Future: Smart

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

    Broader source: Energy.gov [DOE]

    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.

  20. North Star Refrigerator: Proposed Penalty (2013-CE-5355)

    Broader source: Energy.gov [DOE]

    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.

  1. Commercial Refrigerator Door: Proposed Penalty (2013-CE-5351)

    Broader source: Energy.gov [DOE]

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

  2. Monthly Variable-based Degree Day Template: A Spreadsheet Procedure Calculating a 3 Parameter Change-point Model for Residential or Commercial Buildings 

    E-Print Network [OSTI]

    Landman, D. S.; Haberl, J. S.

    1996-01-01T23:59:59.000Z

    This report presents a spreadsheet procedure for calculating a variable-based degree day or three parameter change-point models using monthly utility billing data and coincident weather data. These models were used to model monthly energy...

  3. Design and construction of the astronautics refrigerator magnet

    SciTech Connect (OSTI)

    Dresner, L.

    1994-05-01T23:59:59.000Z

    This document reports on the design, construction, and testing of a 7-Tesla, 4-in. bore superconducting magnet for use in the Astronautics Refrigerator Experiment. The magnet is a single-strand, layer-wound, potted solenoid wound with Formvar-insulated SSC strands. The magnet was constructed by American Magnetics, Inc. of Oak Ridge and has been installed in the Astronautics Refrigerator Experiment at the Astronautics Technology Center in Madison, Wisconsin.

  4. Applications Tests of Energy Efficient, Environmentally Friendly Refrigerants

    E-Print Network [OSTI]

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

    APPLICATIONS TESTS OF ENERGY EFFICIENT, ENVIRONMENTALLY FRIENDLY REFRIGERANTS JONATHAN NIMITZ SUZANNE GLASS EDWARD McCULLOUGH PATRICK DHOOGE PRESIDENT/CEO RESEARCH ASSOCIATE ENGINEER DIR.OF BUSINESS DEV. ENVIRON?v1ENTAL TECHNOLOGY AND EDUCAn.... This goal has been achieved. Additionally, the Ikon? refrigerants were designed to take advantage of the exceptional combustion suppression characteristics of trifluoroiodomethane (CF 3 I), a member of the chemical family known as fluoroiodocarbons...

  5. Refrigerator design for the ambulatory and wheelchair-using elderly

    E-Print Network [OSTI]

    Mills, Mary Sue

    1986-01-01T23:59:59.000Z

    of limitations snd their higher degree of dependence on products. An important arse in product design which has seldom been considered is that of kitchen appliances, and, more specifically, rafr igerators. Refrigerator design has changed little in the last... For the elderly or disabled is a relatively unexplored ares. The present research is an attempt to rectify this neglect. LITERATURE REVIEW Ther s is a striking lack of information in the literature specifically concerned with refrigerators. Those few studies...

  6. Demand Side Management (DSM) Through Absorption Refrigeration Systems

    E-Print Network [OSTI]

    Chao, P. Y.; Shukla, D.; Amarnath, A.; Mergens, E.

    DEMAND SIDE MANAGEMENT (DSM) TIIROUGH ABSORPTION REFRIGERATION SYSTEMS Peter Y. Chao, PhD, Deepak Shukla, PhD, Sr. Process Engineers, TENSA Services, Inc. Ammi Amarnath, Sr. Project Manager, Electrical Power Research Institute Ed. Mergens.... They are Peak Clipping, Valley filling, Load Shifting, Strategic Conservation, Strategic Load Growth, and Flexible Load Shaping. Absorption Refrigeration from waste heat offers a viable option for DSM. This will either reduce the peak load (peak clipping...

  7. Properties and Cycle Performance of Refrigerant Blends Operating Near and Above the Refrigerant Critical Point, Task 2: Air Conditioner System Study

    SciTech Connect (OSTI)

    Piotr A. Domanski; W. Vance Payne

    2002-10-31T23:59:59.000Z

    The main goal of this project was to investigate and compare the performance of an R410A air conditioner to that of an R22 air conditioner, with specific interest in performance at high ambient temperatures at which the condenser of the R410A system may be operating above the refrigerant's critical point. Part 1 of this project consisted of conducting comprehensive measurements of thermophysical for refrigerant R125 and refrigerant blends R410A and R507A and developing new equation of state formulations and mixture models for predicting thermophysical properties of HFC refrigerant blends. Part 2 of this project conducted performance measurements of split-system, 3-ton R22 and R410A residential air conditioners in the 80 to 135 F (27.8 to 57.2 C) outdoor temperature range and development of a system performance model. The performance data was used in preparing a beta version of EVAP-COND, a windows-based simulation package for predicting performance of finned-tube evaporators and condensers. The modeling portion of this project also included the formulation of a model for an air-conditioner equipped with a thermal expansion valve (TXV). Capacity and energy efficiency ratio (EER) were measured and compared. The R22 system's performance was measured over the outdoor ambient temperature range of 80 to 135 F (27.8 to 57.2 C). The same test range was planned for the R410A system. However, the compressor's safety system cut off the compressor at the 135.0 F (57.2 C) test temperature. The highest measurement on this system was at 130.0 F (54.4 C). Subsequently, a custom-manufactured R410A compressor with a disabled safety system and a more powerful motor was installed and performance was measured at outdoor temperatures up to 155.0 F (68.3 C). Both systems had similar capacity and EER performance at 82.0 F (27.8 C). The capacity and EER degradation of both systems were nearly linearly dependent with rising ambient outdoor ambient test temperatures. The performance degradation of R410A at higher temperatures was greater than R22. However, the R22 and R410A systems both operated normally during all tests. Visual observations of the R410A system provided no indication of vibrations or TXV hunting at high ambient outdoor test conditions with the compressor operating in the transcritical regime.

  8. Trace Metal Bioremediation: Assessment of Model Components from Laboratory and Field Studies to Identify Critical Variables

    SciTech Connect (OSTI)

    Peter Jaffe; Herschel Rabitz

    2003-02-14T23:59:59.000Z

    The objective of this project was to gain an insight into the modeling support needed for the understanding, design, and operation of trace metal/radionuclide bioremediation. To achieve this objective, a workshop was convened to discuss the elements such a model should contain. A ''protomodel'' was developed, based on the recommendations of the workshop, and was used to perform sensitivity analysis as well as some preliminary simulations in support for bioremediation test experiments at UMTRA sites. To simulate the numerous biogeochemical processes that will occur during the bioremediation of uranium contaminated aquifers, a time-dependent one-dimensional reactive transport model has been developed. The model consists of a set of coupled, steady state mass balance equations, accounting for advection, diffusion, dispersion, and a kinetic formulation of the transformations affecting an organic substrate, electron acceptors, corresponding reduced species, and uranium. This set of equations is solved numerically, using a finite element scheme. The redox conditions of the domain are characterized by estimating the pE, based on the concentrations of the dominant terminal electron acceptor and its corresponding reduced specie. This pE and the concentrations of relevant species are passed to a modified version of MINTEQA2, which calculates the speciation and solubilities of the species of interest. Kinetics of abiotic reactions are described as being proportional to the difference between the actual and equilibrium concentration. A global uncertainty assessment, determined by Random Sampling High Dimensional Model Representation (RS-HDMR), was performed to attain a phenomenological understanding of the origins of output variability and to suggest input parameter refinements as well as to provide guidance for field experiments to improve the quality of the model predictions. Results indicated that for the usually high nitrate contents found ate many DOE sites, overall bioremediation of trace metals was highly sensitive to the formulation of the denitrification process. Simulations were performed to illustrate the effect of biostimulation on the transport and precipitation of uranium in the subsurface, at conditions equivalent to UMTRA sites. These simulations predicted that uranium would precipitate in bands that are located relatively close to the acetate injection well. The simulations also showed the importance of properly determining U(IV) oxidative dissolution rates, in order to assess the stability of precipitates once oxygenated water reenters the aquifer after bioremediation is discontinued. The objective of this project was to provide guidance to NABIR's Systems Integration Element, on the development of models to simulate the bioremediation of trace metals and radionuclides. Such models necessarily need to integrate hydrological, geochemical, and microbiological processes. In order to gain a better understanding of the key processes that such a model should contain, it was deemed desirable to convene a workshop with experts from these different fields. The goal was to obtain a preliminary consensus on the required level of detail for the formulations of these different chemical, physical, and microbiological processes. The workshop was held on December 18, 1998.

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

    SciTech Connect (OSTI)

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

    1998-03-01T23:59:59.000Z

    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.

  10. Heat exchanger bypass system for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01T23:59:59.000Z

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

  11. Toward hydro-social modeling: Merging human variables and the social sciences with climate-glacier runoff models (Santa River, Peru)

    E-Print Network [OSTI]

    McKenzie, Jeffrey M.

    Toward hydro-social modeling: Merging human variables and the social sciences with climate mountain range, this paper provides a holistic hydro-social framework that identifies five major human of watershed dynamics. This hydro-social framework has wide- spread implications for hydrological modeling

  12. Heat pump employing optimal refrigerant compressor for low pressure ratio applications

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1982-01-01T23:59:59.000Z

    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.

  13. Modeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A. Cooky

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    and multivariable. The control scheme jointly manages fuel and cam position. 1 Introduction. Modern automobile external exhaust gas recirculation (EGR) systems commonly used for NOx reduction. Control SystemsModeling and Control of a Spark Ignition Engine with Variable Cam Timing A. G. Stefanopoulou, J. A

  14. 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

  15. Phase Precession and Variable Spatial Scaling in a Periodic Attractor Map Model of Medial Entorhinal Grid Cells With Realistic

    E-Print Network [OSTI]

    Hasselmo, Michael

    Phase Precession and Variable Spatial Scaling in a Periodic Attractor Map Model of Medial Entorhinal Grid Cells With Realistic After-Spike Dynamics Zaneta Navratilova,1,2 Lisa M. Giocomo,3,4 Jean that describes the generation of the spatial (grid fields) and temporal (phase precession) properties of medial

  16. Effect of grid size on runoff and soil moisture for a variable-source-area hydrology model

    E-Print Network [OSTI]

    Walter, M.Todd

    landscapes are dependent on the distribution and pattern of soil moisture and water transport. In this paper for efficient manage- ment of water quality [U.S. Environmental Protection Agency, 1994, 1995, 1996Effect of grid size on runoff and soil moisture for a variable-source-area hydrology model Wen

  17. Chemometric calibration of infrared spectrometers: selection and validation of variables by non-linear models

    E-Print Network [OSTI]

    Verleysen, Michel

    regression (PCR) and partial least squares regression (PLSR). Then, we will propose to incorporate non-linearChemometric calibration of infrared spectrometers: selection and validation of variables by non-linear (step by step) for the selection of spectral variables, using linear regression or neural networks

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    ICEBO2006, Shenzhen, China HVAC Technologies for Energy Efficiency, Vol. IV-10-4 Improvement of the Performance for an Absorption Refrigerating System with Lithium bromide-water as Refrigerant by Increasing Absorption... in order to lay a theoretical foundation of improving the performance of whole LBAC. 2. THE PRINCIPLE OF ENHANCING ABSORPTION EFFICIENCY OF THE ABSORBER It is well known that the absorption of ICEBO2006, Shenzhen, China HVAC...

  19. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

    Mark J. Bergander

    2005-08-29T23:59:59.000Z

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

  20. JOURNAL DE PHYSIQUE Colloque C6, supplment au n 8, Tome 39, aot 1978, page C6-1598 MAGNETIC REFRIGERATORS FOR USE AT ROOM TEMPERATURE AND BELOW+

    E-Print Network [OSTI]

    Boyer, Edmond

    spéci- fiques de réseau peuvent être rendues petites. Abstract.- Magnetic Carnot cycle refrigerators. Four magnetic refrigerators have been built, but no economically viable unit is in operation. However, fundamental considera- tion indicates that magnetic refrigerators should eventually replace gas refrigerators

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

    DOE Patents [OSTI]

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

    1999-01-01T23:59:59.000Z

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

  2. The development of a proff of principle superfluid Joule-Thomson refrigerator for cooling below 1 Kelvin

    E-Print Network [OSTI]

    Miller, Franklin K., 1970-

    2005-01-01T23:59:59.000Z

    A new type of sub-Kelvin refrigerator, the superfluid Joule-Thomson refrigerator, has been developed and its performance has been experimentally verified. This refrigerator uses a liquid superfluid mixture of He and 4He ...

  3. Performance of HCFC22 alternative refrigerants

    SciTech Connect (OSTI)

    Jung, D.; Kim, C.B.; Song, Y.J.; Park, B.J.

    1999-07-01T23:59:59.000Z

    In this study, 14 refrigerant mixtures composed of R32, R125, R134a, R152a, R290(Propane) and R1270(Propylene) were tested in a breadboard heat pump in an attempt to replace R22 used in residential air-conditioners. The test heat pump was of 1 ton capacity with water as the secondary heat transfer fluids. All tests were conducted under ARI test A condition. Test results how that ternary mixtures composed of R32, R125, and R134a have 4 {approximately} 5% higher coefficient of performance(COP) and capacity than R22. Hence they seem to be promising alternatives for R22. On the other hand, ternary mixtures containing R125, R134a, and R152a have lower COPs and capacities than R22. R290/R134 azeotrope also shows 3--4% increases in COP and capacity. The compressor discharge and dome temperatures of all the mixtures tested are lower than those of R22 by 15.9--34.7 C and 5.5--14.3 C respectively, indicating that these mixtures would offer better system reliability and longer life time than R22. Finally, the test results with a suction line heat exchanger (SLHX) indicated that SLHX must be used with special care in air-conditioners since its effect is fluid dependent.

  4. Enriching the exploration of the mUED model with event shape variables at the CERN LHC

    E-Print Network [OSTI]

    Amitava Datta; Anindya Datta; Sujoy Poddar

    2011-11-12T23:59:59.000Z

    We propose a new search strategy based on the event shape variables for new physics models where the separations among the masses of the particles in the spectrum are small. Collider signature of these models, characterised by low $p_T$ leptons/jets and low missing $p_T$, are known to be difficult to look for. The conventional search strategies involving hard cuts may not work in such situations. As a case study, we have investigated the hitherto neglected jets + missing $E_T$ signature -known to be a challenging one - arising from the pair productions and decay of $n =1$ KK-excitations of gluons and quarks in the minimal Universal Extra Dimension (mUED) model. Judicious use of the event shape variables, enables us to reduce the Standard Model backgrounds to a negligible level . We have shown that in mUED, $R^{-1}$ upto $850 ~\\rm GeV$, can be explored or ruled out with 12 fb$^{-1}$ of integrated luminosity at the 7 TeV run of the LHC. We also discuss the prospects of employing these variables for searching other beyond standard model physics with compressed or partially compressed spectra.

  5. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Term Variability of Solar Power," LBNL Report No. 3884E,High penetration of solar power is highly desirable from ansimilarity to the shape of solar power fluctuations [11].

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

    E-Print Network [OSTI]

    Joshi, Praveen Sudhakar

    1999-01-01T23:59:59.000Z

    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...

  7. Performance testing of a commercially produced cryogenic refrigerator

    SciTech Connect (OSTI)

    Keshock, E.G. (Tennessee Univ., Knoxville, TN (USA). Dept. of Mechanical and Aerospace Engineering); Murphy, R.W. (Oak Ridge National Lab., TN (USA))

    1990-09-01T23:59:59.000Z

    A commercially available cryogenic refrigeration unit, model M-20, (3-phase, 60-Hz, 230-V) manufactured by Cryodynamics, Inc., was subjected to laboratory testing to measure some of its performance characteristics. Comparisons were made with those performance characteristics given in manufacturer literature for the M-20 unit (3-phase, 400-Hz, 208-V). At 77 K, the measured cooling capacity of the 60-Hz/230-V unit was very nearly the same (<2% difference) as the specified capacity (110 W) of the 400-Hz/208-V unit. At temperature levels higher than 77 K, measured cooling capacities exceeded the manufacturer product data sheet values. Coefficients of performance (COP) based on the experimental measurements ranged from about 0.37 at 250 K to 0.03 at 70 K. Comparison of measured to ideal (Carnot cycle) COPs yielded values ranging from about 8 to 18%, with broad maximum occurring between approximately 100 and 150 K. Finally, the measured cool-down time from room temperature to 77 K was about 10 minutes compared with a specification sheet value of 7.4 minutes. This difference may be attributed to lower thermal mass (without heater block) and higher operating frequency conditions associated with the specification. 6 figs., 2 tabs.

  8. Environmental assessment for proposed energy conservation standards for refrigerators, refrigerator-freezers, and freezers

    SciTech Connect (OSTI)

    NONE

    1996-01-01T23:59:59.000Z

    This Environmental Assessment (EA) on the candidate energy conservation standards for refrigerators, refrigerator-freezers, and freezers was prepared pursuant to the National Environmental Policy Act of 1969 (NEPA), regulations of the Council on Environmental Quality, Title 40, Code of Federal 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 Conservation Act. The EA presents the associated environmental impacts from four energy conservation standards for this type of household appliance. For purposes of this EA, each standard is an alternative action and is compared to what is expected to happen if no new standards for this type of product were finalized, i.e., the no action alternative. Of the four energy conservation standard levels considered, standard level 4 has the highest level of energy efficiency and the largest environmental impact. The proposed action implementing Standard Level 1 would have the least environmental impacts, through emission reductions, of the four alternatives. The description of the standards results from the appliance energy-efficiency analyses conducted for the rulemaking. The presentation of environmental impacts for each of the alternatives appears at Section 3 of the EA.

  9. Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation and Transient Dynamics during the Twentieth and Twenty-First Centuries

    E-Print Network [OSTI]

    Hoffman, Forrest M.

    Atmospheric Carbon Dioxide Variability in the Community Earth System Model: Evaluation pathways (RCPs 4.5 and 8.5) using the Community Earth System Model­Biogeochemistry (CESM1- BGC). CO2

  10. Variable Selection for Modeling the Absolute Magnitude at Maximum of Type Ia Supernovae

    E-Print Network [OSTI]

    Uemura, Makoto; Kawabata, S; Ikeda, Shiro; Maeda, Keiichi

    2015-01-01T23:59:59.000Z

    We discuss what is an appropriate set of explanatory variables in order to predict the absolute magnitude at the maximum of Type Ia supernovae. In order to have a good prediction, the error for future data, which is called the "generalization error," should be small. We use cross-validation in order to control the generalization error and LASSO-type estimator in order to choose the set of variables. This approach can be used even in the case that the number of samples is smaller than the number of candidate variables. We studied the Berkeley supernova database with our approach. Candidates of the explanatory variables include normalized spectral data, variables about lines, and previously proposed flux-ratios, as well as the color and light-curve widths. As a result, we confirmed the past understanding about Type Ia supernova: i) The absolute magnitude at maximum depends on the color and light-curve width. ii) The light-curve width depends on the strength of Si II. Recent studies have suggested to add more va...

  11. PUBLISHED ONLINE: 16 JANUARY 2011 | DOI: 10.1038/NPHYS1871 Piezoresistive heat engine and refrigerator

    E-Print Network [OSTI]

    Loss, Daniel

    and refrigerator P. G. Steeneken*, K. Le Phan, M. J. Goossens, G. E. J. Koops, G. J. A. M. Brom, C. van der Avoort to reduce these thermal fluctuations, therefore operating as a refrigerator. M ost heat engines operate

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

    E-Print Network [OSTI]

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

    2006-01-01T23:59:59.000Z

    Dealing with the terrace in rebuilt refrigerators influences the performance characteristics, performance safety and construction costs. This paper researches the heat transfer of the terrace of the rebuilt refrigerator by the numerical method...

  13. Elastohydrodynamic Lubrication with Polyolester Lubricants and HFC Refrigerants, Final Report, Volume 1

    SciTech Connect (OSTI)

    Gunsel, Selda; Pozebanchuk, Michael

    1999-04-01T23:59:59.000Z

    The objective of this study was to investigate the film formation properties of refrigeration lubricants using the ultrathin film elastohydrodynamic (EHD) interferometry technique and to study the effects of refrigerants on film formation. Film thickness measurements were conducted as a function of lubricant viscosity, speed, temperature, and refrigerant concentration. Based on the EHD film thickness data, effective pressure-viscosity coefficients were calculated for the test fluids at different temperatures and the effects of refrigerants on pressure-viscosity properties were investigated.

  14. Frost sensor for use in defrost controls for refrigeration

    DOE Patents [OSTI]

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

    2002-01-01T23:59:59.000Z

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

  15. The Hall D solenoid helium refrigeration system at JLab

    SciTech Connect (OSTI)

    Laverdure, Nathaniel A. [JLAB; Creel, Jonathan D. [JLAB; Dixon, Kelly d. [JLAB; Ganni, Venkatarao [JLAB; Martin, Floyd D. [JLAB; Norton, Robert O. [JLAB; Radovic, Sasa [JLAB

    2014-01-01T23:59:59.000Z

    Hall D, the new Jefferson Lab experimental facility built for the 12GeV upgrade, features a LASS 1.85 m bore solenoid magnet supported by a 4.5 K helium refrigerator system. This system consists of a CTI 2800 4.5 K refrigerator cold box, three 150 hp screw compressors, helium gas management and storage, and liquid helium and nitrogen storage for stand-alone operation. The magnet interfaces with the cryo refrigeration system through an LN2-shielded distribution box and transfer line system, both designed and fabricated by JLab. The distribution box uses a thermo siphon design to respectively cool four magnet coils and shields with liquid helium and nitrogen. We describe the salient design features of the cryo system and discuss our recent commissioning experience.

  16. Effects of refrigeration in a transportable cryogenic aerospace application

    SciTech Connect (OSTI)

    Donovan, B.D.; Mahefkey, T. [Wright Lab., Wright-Patterson AFB, OH (United States); Ramalingam, M.L. [UES, Inc., Dayton, OH (United States)

    1995-12-31T23:59:59.000Z

    Preliminary feasibility studies, based on refrigeration thermodynamics, have been conducted for candidate power conditioning components in a 1MWe terrestrial/transportable cryogenic power system. The cryogenic power system being considered has a super conducting generator for high power applications such as the power source for a Ground Based Radar (GBR) System. While the superconducting generator operates at 77K or lower, the present analysis indicates that significant benefits cannot be derived by cooling the various components of the power conditioning system to such low temperatures. It was found that, by operating the power conditioning component at 150K instead of at 77K the overall system efficiency was not jeopardized by way of large input power requirements to dissipate small refrigerator loads. This is an acute problem as current cryogenic refrigeration systems allow for very low levels of energy dissipation while performing at about 7 to 10% of the Carnot coefficients of performance (COP) between 300K and 77K.

  17. Review and comparison of magnet designs for magnetic refrigeration

    E-Print Network [OSTI]

    Bjørk, R; Smith, A; Pryds, N

    2014-01-01T23:59:59.000Z

    One of the key issues in magnetic refrigeration is generating the magnetic field that the magnetocaloric material must be subjected to. The magnet constitutes a major part of the expense of a complete magnetic refrigeration system and a large effort should therefore be invested in improving the magnet design. A detailed analysis of the efficiency of different published permanent magnet designs used in magnetic refrigeration applications is presented in this paper. Each design is analyzed based on the generated magnetic flux density, the volume of the region where this flux is generated and the amount of magnet material used. This is done by characterizing each design by a figure of merit magnet design efficiency parameter, $\\Lambda_\\mathrm{cool}$. The designs are then compared and the best design found. Finally recommendations for designing the ideal magnet design are presented based on the analysis of the reviewed designs.

  18. An SMLD joint PDF model for turbulent non-premixed combustion using the flamelet progress-variable approach

    E-Print Network [OSTI]

    Coclite, Alessandro; De Palma, Pietro; Cutrone, Luigi; Ihme, Matthias

    2015-01-01T23:59:59.000Z

    This paper provides an improved flamelet/progress variable (FPV) model for the simulation of turbulent combustion, employing the statistically most likely distribution (SMLD) approach for the joint probability density function (PDF) of the mixture fraction, Z, and of the progress parameter, {\\Lambda} . Steady-state FPV models are built presuming the func- tional shape of the joint PDF of Z and {\\Lambda} in order to evaluate Favre-averages of thermody- namic quantities. The mixture fraction is widely assumed to behave as a passive scalar with a mono-modal behaviour modelled by a \\b{eta} -distribution. Moreover, under the hypothesis that Z and {\\Lambda} are statistically independent, the joint PDF coincides with the product of the two marginal PDFs. In this work we discuss these two constitutive hypotheses. The proposed model evaluates the most probable joint distribution of Z and {\\Lambda} , relaxing some crucial as- sumption on their statistical behaviour. This provides a more general model in the context of ...

  19. Dark Energy Model in Anisotropic Bianchi Type-III Space-Time with Variable EoS Parameter

    E-Print Network [OSTI]

    Anirudh Pradhan; Hassan Amirhashchi

    2010-10-12T23:59:59.000Z

    A new dark energy model in anisotropic Bianchi type-III space-time with variable equation of state (EoS) parameter has been investigated in the present paper. To get the deterministic model, we consider that the expansion $\\theta$ in the model is proportional to the eigen value $\\sigma^{2}_{~2}$ of the shear tensor $\\sigma^{j}_~i$. The EoS parameter $\\omega$ is found to be time dependent and its existing range for this model is in good agreement with the recent observations of SNe Ia data (Knop et al. 2003) and SNe Ia data with CMBR anisotropy and galaxy clustering statistics (Tegmark et al. 2004). It has been suggested that the dark energy that explains the observed accelerating expansion of the universe may arise due to the contribution to the vacuum energy of the EoS in a time dependent background. Some physical aspects of dark energy model are also discussed.

  20. PHYSICAL AND CHEMICAL CHANGES OF PINK SHRIMP, PANDALUS BOREALIS, HELD IN CARBON DIOXIDE MODIFIED REFRIGERATED

    E-Print Network [OSTI]

    REFRIGERATED SEAWATER COMPARED WITH PINK SHRIMP HELD IN ICE FERN A. BULLARD AND JEFF COLLINSl ABSTRACT Pink ahrimp,PandaluB borealis, were held in carbon dioxide modified refrigerated seawater for 12.5 days refrigerated seawater were acceptable up to 9.5 days and those held in ice up to 6.5 days. Data on weight

  1. Two-phase refrigerant flow instability analysis and active control in transient electronics cooling systems

    E-Print Network [OSTI]

    Peles, Yoav

    Two-phase refrigerant flow instability analysis and active control in transient electronics cooling Pressure-drop oscillation Refrigeration system Two-phase cooling Active control Transient heat load a b s t r a c t Two-loop refrigeration systems are being explored for two-phase cooling of ultra high power

  2. On the Trade-off between Energy Consumption and Food Quality Loss in Supermarket Refrigeration Systems

    E-Print Network [OSTI]

    Skogestad, Sigurd

    On the Trade-off between Energy Consumption and Food Quality Loss in Supermarket Refrigeration refrigeration systems. Compared with the traditional operation with pressure control, a large poten- tial inside display cabinets. This paper discusses a dynamic optimization of commer- cial refrigeration

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    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-acceptable refrigerants. Whether involving design of specific new products or refriger- ants to which the entire industry

  4. M. Bahrami ENSC 461 (S 11) Assignment 3 1 Assignment #3 (Refrigeration)

    E-Print Network [OSTI]

    Bahrami, Majid

    M. Bahrami ENSC 461 (S 11) Assignment 3 1 MECH 461 Assignment #3 (Refrigeration) Assignment date: Tuesday Jan 29, 2011 Problem 1: Figure below shows a steam jet refrigeration system that produces chilled refrigeration) = 211 kJ/min. water Sat. vapor at 200 kPa Ejector nozzle Steam jet Sat. vapor P = 4 kPa Condenser

  5. Chapter 5: Refrigeration Process Control: A Pragmatic Design Approach 75 55.. RREEFFRRIIGGEERRAATTIIOONN PPRROOCCEESSSS

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Chapter 5: Refrigeration Process Control: A Pragmatic Design Approach 75 55-stage refrigeration system. Several control configurations are examined. These configurations were chosen An analysis of the relationships in the two-stage refrigeration system shows the availability of 5 degrees

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

    E-Print Network [OSTI]

    Page 1 of 4 Refrigerant Charge Verification: 70°F Return Air Requirement This article describes refrigerant charge verification when the outdoor temperature is between 55 and 65°F, in accordance than 70°F has been an explicit requirement since the refrigerant charge verification protocol was first

  7. Computers and Chemical Engineering 31 (2007) 712721 Optimal operation of simple refrigeration cycles

    E-Print Network [OSTI]

    Skogestad, Sigurd

    2007-01-01T23:59:59.000Z

    Computers and Chemical Engineering 31 (2007) 712­721 Optimal operation of simple refrigeration online 16 January 2007 Abstract The paper focuses on the operation of simple refrigeration cycles of about 2%. In this paper, refrigeration (cooling) cycles are considered, but the same principles apply

  8. Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Evaporation and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate and Condensation Heat Transfer Performance of Flammable Refrigerants in a Brazed Plate Heat Exchanger Sheila C ........................................................... 8 3. Average relative difference (%) in calculated heat transfer rates for refrigerants and HTF

  9. Use of chlorofluorocarbons in refrigeration, insulation and mobile air conditioning in the USA*

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    FILE COPY DO NOT REMOVE Use of chlorofluorocarbons in refrigeration, insulation and mobile air in refrigeration equipment and mobile air conditioners, or as the blowing agent in foam insulations. When again accounted for _ 40 %of the potential risk to the environment. Refrigeration, mobile air

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

    E-Print Network [OSTI]

    Boyer, Edmond

    RHEOLOGICAL STUDY OF TWO-PHASE SECONDARY FLUIDS FOR REFRIGERATION AND AIR CONDITIONING. Mylène have promising application in refrigeration thanks to their large cooling capacity and their storage Because it is nowadays necessary to phase out CFCs or HCFCs fluids from the refrigeration industry

  11. Balancing Energy Consumption and Food Quality Loss in Supermarket Refrigeration System

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Balancing Energy Consumption and Food Quality Loss in Supermarket Refrigeration System J. Cai and J energy consumption and food quality loss, at varying ambient condition, in a supermarket refrigeration-designed optimal control scheme, continuously maintaining a commer- cial refrigeration system at its optimum

  12. University of Connecticut Daily Temperature Log for Unit Based Medication Refrigerators

    E-Print Network [OSTI]

    Oliver, Douglas L.

    University of Connecticut Daily Temperature Log for Unit Based Medication Refrigerators Month: If the refrigerator temperature falls out of the acceptable range of 36 to 46 degrees Fahrenheit or 2.2 to 7.7 degrees. * If the refrigerator temperature falls out of range please document your actions in the follow-up column. #12;

  13. Design and Analysis of a Nested Halbach Permanent Magnet Magnetic Refrigerator

    E-Print Network [OSTI]

    Victoria, University of

    Design and Analysis of a Nested Halbach Permanent Magnet Magnetic Refrigerator by Armando Tura BEng Committee Design and Analysis of a Nested Halbach Permanent Magnet Magnetic Refrigerator by Armando Tura with the potential to create efficient and compact refrigeration devices is an active magnetic regenerative

  14. A Miniature Continuous Adiabatic Demagnetization Refrigerator with compact shielded superconducting magnets.

    E-Print Network [OSTI]

    Timbie, Peter

    insulated from the bath. The refrigeration cycle exploits the interaction between the atomic magnetic a magnetic field is applied to a param- agnetic refrigerant, its magnetic spins are aligned and orderedA Miniature Continuous Adiabatic Demagnetization Refrigerator with compact shielded superconducting

  15. Proceedings of the 1993 non-fluorocarbon insulation, refrigeration and air conditioning technology workshop

    SciTech Connect (OSTI)

    Not Available

    1994-09-01T23:59:59.000Z

    Sessions included: HFC blown polyurethanes, carbon dioxide blown foam and extruded polystyrenes, plastic foam insulations, evacuated panel insulation, refrigeration and air conditioning, absorption and adsorption and stirling cycle refrigeration, innovative cooling technologies, and natural refrigerants. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

  16. Demand Response Opportunities in Industrial Refrigerated Warehouses in California

    SciTech Connect (OSTI)

    Goli, Sasank; McKane, Aimee; Olsen, Daniel

    2011-06-14T23:59:59.000Z

    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.

  17. Mass Measurements of AGN from Multi-Lorentzian Models of X-ray Variability. I. Sampling Effects in Theoretical Models of the rms^2-M_BH Correlation

    E-Print Network [OSTI]

    Martin E. Pessah

    2006-10-11T23:59:59.000Z

    Recent X-ray variability studies suggest that the log of the square of the fractional rms variability amplitude, rms^2, seems to correlate with the log of the AGN black-hole mass, M_BH, with larger black holes being less variable for a fixed time interval. This has motivated the theoretical modeling of the rms^2-M_BH correlation with the aim of constraining AGN masses based on X-ray variability. A viable approach to addressing this problem is to assume an underlying power spectral density with a suitable mass dependence, derive the functional form of the rms^2-M_BH correlation for a given sampling pattern, and investigate whether the result is consistent with the observations. For simplicity, previous studies, inspired by the similarities shared by the timing properties of AGN and X-ray binaries, have explored model power spectral densities characterized by broken power laws. and ignored, in general, the distorting effects that the particular sampling pattern imprints in the observed power spectral density. Motivated by the latest timing results from X-ray binaries, obtained with RXTE, we propose that AGN broad-band noise spectra consist of a small number of Lorentzian components. This assumption allows, for the first time, to fully account for sampling effects in theoretical models of X-ray variability in an analytic manner. We show that, neglecting sampling effects when deriving the fractional rms from the model power spectral density can lead to underestimating it by a factor of up to 80% with respect to its true value for the typical sampling patterns used to monitor AGN. We discuss the implications of our results for the derivation of AGN masses using theoretical models of the rms^2-M_BH correlation. (Abridged)

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

    E-Print Network [OSTI]

    Fang, Yue

    2006-08-16T23:59:59.000Z

    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...

  19. Bayesian nonparametric inference for unit level models with categorical response variables

    E-Print Network [OSTI]

    Carriquiry, Alicia

    -moderately high, 4-high. · soil wind potential, three categories: 1-low, 2-moderate, 3-moderately high(xij + zij i , 1), i = 1, .., N, j = 1, .., ni i |b N(0, b) · K = 4 for runoff potential and K = 3 for wind of the output variables are ordinal scores: · soil runoff potential, four categories: 1-low, 2-moderate, 3

  20. Cooling an electron gas using quantum dot based electronic refrigeration

    E-Print Network [OSTI]

    Prance, Jonathan Robert

    2009-10-13T23:59:59.000Z

    Cooling an electron gas using quantum dot based electronic refrigeration Jonathan Robert Prance August 28, 2009 Downing College, University of Cambridge A thesis submitted for the degree of Doctor of Philosophy Preface The work presented... dots. Conventionally, low temperature measurements of 2DEGs are made by cooling the sample to 1.5 K with liquid Helium-4, to 300 mK with liquid Helium-3, or even down to a few mK using a dilution refrigerator. However, at lower temperatures the electron...

  1. Supermarket with Ground Coupled Carbon Dioxide Refrigeration Plant

    E-Print Network [OSTI]

    Rehault, N.

    2012-01-01T23:59:59.000Z

    are massive energy consumers [4] EnOB [5] Kauffeld 2009 ? Fraunhofer ISE 4 Global emissions of fluorinated greenhouse gases Source: UBA ? 12.2010 1,1% 7,9% F-gas contribution to greenhouse effect 1. Backgrounds ? Fraunhofer ISE 5 Energy breakdown... 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...

  2. Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

    DOE Patents [OSTI]

    Barclay, John A. (Madison, WI); Stewart, Walter F. (Marshall, WI); Henke, Michael D. (Los Alamos, NM); Kalash, Kenneth E. (Los Alamos, NM)

    1987-01-01T23:59:59.000Z

    A magnetic refrigerator operating in the 12 to 77K 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.

  3. Magnetic refrigeration apparatus with belt of ferro or paramagnetic material

    DOE Patents [OSTI]

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

    1986-04-03T23:59:59.000Z

    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.

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    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. 1 (BSM1) and the activated sludge model no. 1 (ASM1). The objective is to search for a control

  5. 2014-07-10 Issuance: Test Procedures for Refrigerators, Refrigerator-Freezers, and Freezers; Final Rule Correction

    Broader source: Energy.gov [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.

  6. Testing a model of variability of X-ray reprocessing features in Active Galactic Nuclei

    E-Print Network [OSTI]

    P. T. Zycki; A. Rozanska

    2001-02-13T23:59:59.000Z

    A number of recent results from X-ray observations of Active Galactic Nuclei involving the Fe K alpha line (reduction of line variability compared to the X-ray continuum variability, the X-ray ``Baldwin effect'') were attributed to a presence of a hot, ionized skin of an accretion disc, suppressing emission of the line. The ionized skin appears as a result of the thermal instability of X-ray irradiated plasma. We test this hypothesis by computing the Thomson thickness of the hot skin on top of the 'alpha P_tot' Shakura-Sunyaev disc, by simultaneously solving the vertical structure of both the hot skin and the disc. We then compute a number of relations between observable quantities, e.g. the hard X-ray flux, amplitude of the observed reprocessed component, relativistic smearing of the K alpha line, the r.m.s. variability of the hard X-rays. These relations can be compared to present and future observations. We point out that this mechanism is unlikely to explain the behaviour of the X-ray source in MCG-6-30-15, where there is a number of arguments against the existence of a thick hot skin, but it can work for some other Seyfert 1 galaxies.

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

    E-Print Network [OSTI]

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

    2014-12-01T23:59:59.000Z

    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.

  8. Demand Response Opportunities in Industrial Refrigerated Warehouses in

    E-Print Network [OSTI]

    LBNL-4837E Demand Response Opportunities in Industrial Refrigerated Warehouses in California Sasank thereof or The Regents of the University of California. #12;Demand Response Opportunities in Industrial centralized control systems can be excellent candidates for Automated Demand Response (Auto- DR) due

  9. COMPUTER DESIGN AND OPTIMIZATION OF CRYOGENIC REFRIGERATION SYSTEMS

    E-Print Network [OSTI]

    green, M.A.

    2011-01-01T23:59:59.000Z

    and the assumed electrical energy cost is $0.04 per kWh.cost (the cost is given in US$ per kWh at 80.4°K) andThe cost of nitrogen refrigeration given in $ per kWh at

  10. Superefficient Refrigerators: Opportunities and Challenges for Efficiency Improvement Globally

    SciTech Connect (OSTI)

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

    2014-08-01T23:59:59.000Z

    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.

  11. Triple loop heat exchanger for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01T23:59:59.000Z

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

  12. Procurement and commissioning of the CHL refrigerator at CEBAF

    SciTech Connect (OSTI)

    Chronis, W.C.; Arenius, D.M.; Bevins, B.S.; Ganni, V.; Kashy, D.H.; Keesee, M.M.; Reid, T.R.; Wilson, J.D.

    1996-08-01T23:59:59.000Z

    The CEBAF Central Helium Liquefier (CHL) provides 2K refrigeration to the 338 superconducting niobium cavities in two 400 MeV linacs and one 45 MeV injector. The CHL consists of three first stage and three second stage compressors, a 4.5K cold box, a 2K cold box, liquid and gaseous helium storage, liquid nitrogen storage, and transfer lines. Figure 1 presents a block diagram of the CHL refrigerator. The system was designed to provide 4.8 kW of primary refrigeration at 2K, 12 kW of shield refrigeration at 45K for the linac cryomodules, and 10 g/s of liquid flow for the end stations. In April 1994, stable 2K operation of the previously uncommissioned cold compressors was achieved. The cold compressors are a cold vacuum pump with an inlet temperature of circa 3.0K. These compressors operate on magnetic bearing,s and therefore eliminate the possibility of contamination due to any air leaks into the system. Operational data and commissioning experience as they relate to the warm gaseous helium compressors, turbines, instrumentation and control, and the cold compressors are presented.

  13. Dry dilution refrigerator with 4He-1K-loop

    E-Print Network [OSTI]

    Uhlig, Kurt

    2014-01-01T23:59:59.000Z

    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...

  14. 1st TECCS meeting, 26th April 2007 Adsorption Refrigeration

    E-Print Network [OSTI]

    Davies, Christopher

    the refrigerant into a solid rather than ABsorbing it into a liquid. It is a discontinuous (batch) process #12;1st;1st TECCS meeting, 26th April 2007 Rotor and stator of ammonia circulator #12;1st TECCS meeting, 26th

  15. Designing Augmented Refrigerator Magnets Rachel Eardley, Laurel Swan

    E-Print Network [OSTI]

    Hunt, Galen

    Designing Augmented Refrigerator Magnets Rachel Eardley, Laurel Swan , Abi Sellen Alex S. Taylor In this poster we present the conceptual designs for several augmented fridge magnets, each illustrative artifacts. Specifically, it reso- nates with the manner in which fridge surfaces, magnets and the content

  16. REVIEW OF SUPERCONDUCTING MAGNETOMETERS AND CRYOGENIC REFRIGERATION TECHNIQUES

    E-Print Network [OSTI]

    Boyer, Edmond

    3. REVIEW OF SUPERCONDUCTING MAGNETOMETERS AND CRYOGENIC REFRIGERATION TECHNIQUES By W. S. GOREE to devices for shielding, stabilizing, measuring and producing magnetic fields. The zero resistance property of superconductors has been used to construct magnets capable of producing magnetic fields up to 140 kgauss

  17. Waste Heat Recovery from Refrigeration in a Meat Processing Facility

    E-Print Network [OSTI]

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

    1980-01-01T23:59:59.000Z

    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...

  18. A model for variable phytoplankton stoichiometry based on cell protein regulation

    E-Print Network [OSTI]

    Bonachela, J. A; Allison, S. D; Martiny, A. C; Levin, S. A

    2013-01-01T23:59:59.000Z

    Ecology, 50, 188–192, 1969. Droop, M. R. : Vitamin B 12 andfrom quota models – the Droop Cell Quota Model 40 years on,Menten–Monod up- take, Droop’s growth and Liebig’s law,

  19. 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

  20. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23T23:59:59.000Z

    Cataclysmic variables are binary stars in which a relatively normal star is transferring mass to its compact companion. This interaction gives rise to a rich range of behaviour, of which the most noticeable are the outbursts that give the class its name. Novae belong to the class, as do the less well known dwarf novae and magnetic systems. Novae draw their energy from nuclear reactions, while dwarf novae rely on gravity to power their smaller eruptions. All the different classes of cataclysmic variable can be accommodated within a single framework and this article will describe the framework, review the properties of the main types of system and discuss models of the outbursts and of the long-term evolution.

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

    E-Print Network [OSTI]

    David Gelbwaser-Klimovsky; Gershon Kurizki

    2015-01-31T23:59:59.000Z

    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.

  2. Revisiting the Rigidly Rotating Magnetosphere model for $\\sigma$ Ori E - II. Magnetic Doppler imaging, arbitrary field RRM, and light variability

    E-Print Network [OSTI]

    Oksala, M E; Krticka, J; Townsend, R H D; Wade, G A; Prvak, M; Mikulasek, Z; Silvester, J; Owocki, S P

    2015-01-01T23:59:59.000Z

    The initial success of the Rigidly Rotating Magnetosphere (RRM) model application to the B2Vp star sigma OriE by Townsend, Owocki & Groote (2005) triggered a renewed era of observational monitoring of this archetypal object. We utilize high-resolution spectropolarimetry and the magnetic Doppler imaging (MDI) technique to simultaneously determine the magnetic configuration, which is predominately dipolar, with a polar strength Bd = 7.3-7.8 kG and a smaller non-axisymmetric quadrupolar contribution, as well as the surface distribution of abundance of He, Fe, C, and Si. We describe a revised RRM model that now accepts an arbitrary surface magnetic field configuration, with the field topology from the MDI models used as input. The resulting synthetic Ha emission and broadband photometric observations generally agree with observations, however, several features are poorly fit. To explore the possibility of a photospheric contribution to the observed photometric variability, the MDI abundance maps were used to ...

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

    SciTech Connect (OSTI)

    Lowe, K.T.

    2005-10-07T23:59:59.000Z

    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.

  4. A theoretical study on the performances of thermoelectric heat engine and refrigerator with two-dimensional electron reservoirs

    SciTech Connect (OSTI)

    Luo, Xiaoguang, E-mail: 276718626@qq.com; Long, Kailin; Wang, Jun; Qiu, Teng, E-mail: tqiu@seu.edu.cn [Department of Physics, Southeast University, Nanjing 211189 (China); He, Jizhou [Department of Physics, Nanchang University, Nanchang 330031 (China); Liu, Nian [Department of Physical and Electronics, Anhui Science and Technology University, Bengbu 233100 (China)

    2014-06-28T23:59:59.000Z

    Theoretical thermoelectric nanophysics models of low-dimensional electronic heat engine and refrigerator devices, comprising two-dimensional hot and cold reservoirs and an interconnecting filtered electron transport mechanism have been established. The models were used to numerically simulate and evaluate the thermoelectric performance and energy conversion efficiencies of these low-dimensional devices, based on three different types of electron transport momentum-dependent filters, referred to herein as k{sub x}, k{sub y}, and k{sub r} filters. Assuming the Fermi-Dirac distribution of electrons, expressions for key thermoelectric performance parameters were derived for the resonant transport processes, in which the transmission of electrons has been approximated as a Lorentzian resonance function. Optimizations were carried out and the corresponding optimized design parameters have been determined, including but not limited to the universal theoretical upper bound of the efficiency at maximum power for heat engines, and the maximum coefficient of performance for refrigerators. From the results, it was determined that k{sub r} filter delivers the best thermoelectric performance, followed by the k{sub x} filter, and then the k{sub y} filter. For refrigerators with any one of three filters, an optimum range for the full width at half maximum of the transport resonance was found to be <2k{sub B}T.

  5. Development and Validation of WECC Variable Speed Wind Turbine Dynamic Models for Grid Integration Studies

    SciTech Connect (OSTI)

    Behnke, M.; Ellis, A.; Kazachkov, Y.; McCoy, T.; Muljadi, E.; Price, W.; Sanchez-Gasca, J.

    2007-09-01T23:59:59.000Z

    This paper describes reduced-order, simplified wind turbine models for analyzing the stability impact of large arrays of wind turbines with a single point of network interconnection.

  6. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Model (WVM) for Solar PV Power Plants Matthew Lave, Janoutput of a solar photovoltaic (PV) plant was presented andsimulating solar photovoltaic (PV) power plant output given

  7. A Wavelet-Based Variability Model (WVM) for Solar PV Power Plants

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan; Stein, Joshua S

    2013-01-01T23:59:59.000Z

    Model (WVM) for Solar PV Power Plants Matthew Lave, Jansolar photovoltaic (PV) power plant output given a singleproduce a simulated power plant output. The WVM is validated

  8. ResPoNSe: modeling the wide variability of residential energy consumption.

    E-Print Network [OSTI]

    Peffer, Therese; Burke, William; Auslander, David

    2010-01-01T23:59:59.000Z

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

  9. Rao-Blackwellization for Bayesian Variable Selection and Model Averaging in Linear and Binary Regression

    E-Print Network [OSTI]

    West, Mike

    of covariates to use in regression or generalized linear models is a ubiquitous problem. The Bayesian paradigm regression and binary re- gression with non-orthogonal design matrices in conjunction with independent "spike and kernel regression (Clyde and George 2004). The generalization of the Gaussian linear model to other

  10. Observational constraints on models of the Universe with time variable Gravitational and Cosmological constants along MOG

    E-Print Network [OSTI]

    M. Khurshudyan; N. S. Mazhari; D. Momeni; R. Myrzakulov; M. Raza

    2014-06-24T23:59:59.000Z

    The subject of this paper is to investigate the weak regime covariant scalar-tensor-vector gravity (STVG) theory, known as the MOdified gravity (MOG) theory of gravity. First, we show that the MOG in the absence of scalar fields is converted into $\\Lambda(t),G(t)$ models. Time evolution of the cosmological parameters for a family of viable models have been investigated. Numerical results with the cosmological data have been adjusted. We've introduced a model for dark energy (DE) density and cosmological constant which involves first order derivatives of Hubble parameter. To extend this model, correction terms including the gravitational constant are added. In our scenario, the cosmological constant is a function of time. To complete the model,interaction terms between dark energy and dark matter (DM) manually entered in phenomenological form. Instead of using the dust model for DM, we have proposed DM equivalent to a barotropic fluid. Time evolution of DM is a function of other cosmological parameters. Using sophisticated algorithms, the behavior of various quantities including the densities, Hubble parameter, etc. have been investigated graphically. The statefinder parameters have been used for the classification of DE models. Consistency of the numerical results with experimental data of $SneIa+BAO+CMB$ are studied by numerical analysis with high accuracy.

  11. Modeling Biogeochemistry and Flow within Heterogeneous Formations in Variably-Saturated Media

    E-Print Network [OSTI]

    Arora, Bhavna

    2012-10-19T23:59:59.000Z

    to accurately model preferential flow and tracer transport. This research is crucial to agricultural systems where soil and crop management practices modify soil structure and alter macropore densities. The comparison between deterministic and stochastic...

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

    E-Print Network [OSTI]

    Fang, Yue

    2006-08-16T23:59:59.000Z

    To investigate the tropical Atlantic response to the remote El Nino-Southern Oscillation (ENSO) forcing, a Reduced Physics Â? Coupled Global Circulation Model (RP-CGCM) is developed, and four experiments are carried out. ...

  13. TRANSVIP: a solute transport model based on the spatial variability of intrinsic permeability

    E-Print Network [OSTI]

    Freeze, Geoffrey Allan

    1989-01-01T23:59:59.000Z

    groundwater flow and solute transport in three dimensions in both saturated and unsaturated porous media. The model simulates mechanical dispersion using a spatially vari- able intrinsic permeability field. This approach provides a, more realistic physical.... TRANSVIP is a three-dimensional flow and transport model capable of simulating contaminant transport in both saturated and unsaturated porous me- dia and does not assume Fickian dispersion. In TRANSVIP, the flow deviations that cause mechanical...

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

    SciTech Connect (OSTI)

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

    2010-07-29T23:59:59.000Z

    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.

  15. Free displacer and Ringbom displacer for a Malone refrigerator

    SciTech Connect (OSTI)

    Swift, G.W.; Brown, A.O.

    1994-05-01T23:59:59.000Z

    Malone refrigeration uses a liquid near its critical point (instead of the customary gas) as the working fluid in a Stirling, Brayton, or similar regenerative or recuperative cycle. Thus far, we have focused on the Stirling cycle, to avoid the difficult construction of the high-pressure-difference counterflow recuperator required for a Brayton machine. Our first Malone refrigerator used liquid propylene (C{sub 3}H{sub 6}) in a double-acting 4-cylinder Stirling configuration. First measurements with a free displacer used in a liquid working fluid are presented. The displacer was operated both in harmonic mode and in Ringbom mode, in liquid carbon dioxide. The results are in reasonable agreement with expectations.

  16. Circulating heat exchangers for oscillating wave engines and refrigerators

    DOE Patents [OSTI]

    Swift, Gregory W.; Backhaus, Scott N.

    2003-10-28T23:59:59.000Z

    An oscillating-wave engine or refrigerator having a regenerator or a stack in which oscillating flow of a working gas occurs in a direction defined by an axis of a trunk of the engine or refrigerator, incorporates an improved heat exchanger. First and second connections branch from the trunk at locations along the axis in selected proximity to one end of the regenerator or stack, where the trunk extends in two directions from the locations of the connections. A circulating heat exchanger loop is connected to the first and second connections. At least one fluidic diode within the circulating heat exchanger loop produces a superimposed steady flow component and oscillating flow component of the working gas within the circulating heat exchanger loop. A local process fluid is in thermal contact with an outside portion of the circulating heat exchanger loop.

  17. The Quantum Refrigerator: The quest for absolute zero

    E-Print Network [OSTI]

    Yair Rezek; Peter Salamon; Karl Heinz Hoffmann; Ronnie Kosloff

    2008-08-04T23:59:59.000Z

    The scaling of the optimal cooling power of a reciprocating quantum refrigerator is sought as a function of the cold bath temperature as $T_c \\to 0$. The working medium consists of noninteracting particles in a harmonic potential. Two closed-form solutions of the refrigeration cycle are analyzed, and compared to a numerical optimization scheme, focusing on cooling toward zero temperature. The optimal cycle is characterized by linear relations between the heat extracted from the cold bath, the energy level spacing of the working medium and the temperature. The scaling of the optimal cooling rate is found to be proportional to $T_c^{3/2}$ giving a dynamical interpretation to the third law of thermodynamics.

  18. Heat powered refrigeration compressor. Semi-annual technical report

    SciTech Connect (OSTI)

    Goad, R.R.

    1981-01-01T23:59:59.000Z

    The objective of this program is to develop and improve the design of previously started prototypes of the Heat Powered Refrigeration Compressor. To build this prototype and ready it for testing by the University of Evansville is another goal. This prototype will be of similar capacity as the compressor that will eventually be commercially produced. This unit can operate on almost any moderate temperature water heat source. This heat source could include such applications as industrial waste heat, solar, wood burning stove, resistance electrical heat produced by a windmill, or even perhaps heat put out by the condenser of another refrigeration system. Work performed in the past four months has consisted of: engineering of HX-1; comparisons of specifications from different companies to ensure state of the art applications of parts for project; coordinating project requirements with machine shop; designing condenser; and partial assembly of HX-1.

  19. New age water chillers with water as refrigerant

    E-Print Network [OSTI]

    Kühnl-Kinel, J

    1998-01-01T23:59:59.000Z

    Vacuum-process technology producing chilled water needs no refrigerant of the conventional kind, but water from the process itself is used to generate cooling. This eye-catching novelty incorporates many of the considerations about the future of refrigerants: "ozone friendly", no extra demands for safety measures or for skilful operators, no special requirements concerning the installation's components, lower maintenance costs since leakages can be accommodated from the system. Vacuum-process technology may be used not only for production of chilled water but also for Binary Ice - pumpable suspension of minute ice crystals in an aqueous solution. This means that all the advantages related to a latent heat system may become available.

  20. Cryogenics for superconductors: Refrigeration, delivery, and preservation of the cold

    SciTech Connect (OSTI)

    Venkatarao Ganni, James Fesmire

    2012-06-01T23:59:59.000Z

    Applications in superconductivity have become widespread, enabled by advancements in cryogenic engineering. In this paper, the history of cryogenic refrigeration, its delivery, its preservation and the important scientific and engineering advancements in these areas in the last 100 years will be reviewed, beginning with small laboratory dewars to very large scale systems. The key technological advancements in these areas that enabled the development of superconducting applications at temperatures from 4 to 77 K are identified. Included are advancements in the components used up to the present state-of-the-art in refrigeration systems design. Viewpoints as both an equipment supplier and the end-user with regard to the equipment design and operations will be presented. Some of the present and future challenges in these areas will be outlined. Most of the materials in this paper are a collection of the historical materials applicable to these areas of interest.