National Library of Energy BETA

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

    2013-01-01

    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. Variable Refrigerant Flow HVAC 

    E-Print Network [OSTI]

    Jones, S.

    2013-01-01

    Variable refrigerant flow technology HVAC CATEE 2013 San Antonio, TX ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency Conference, San Antonio, Texas Dec. 16-18 What is the acronym VRF? ? Variable Refrigerant Flow Operates like a... 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...

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

    SciTech Connect (OSTI)

    Sharma, Chandan; Raustad, Richard

    2013-06-01

    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. 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

    2013-09-30

    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

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

    E-Print Network [OSTI]

    Jones, S.

    2012-01-01

    Ducted Units Ceiling Suspended Floor Standing 27 VRF Energy-Efficiency and Environmental Impact Utilizing VRF with LEED ? Energy and Atmosphere: VRF can achieve up to 21 points ? Environmental Quality: VRF can achieve up to seven... points LEED NC 3.0 ? Certified: 40-49 points ? Silver: 50-59 points ? Gold: 60-79 points ? Platinum: 80 + points 29 VRF Systems and Energy Modeling ? Energy usage and cost for the VRF systems can be modeled using EnergyPro EnergyPro uses...

  6. Solubility modeling of refrigerant/lubricant mixtures

    SciTech Connect (OSTI)

    Michels, H.H.; Sienel, T.H.

    1996-12-31

    A general model for predicting the solubility properties of refrigerant/lubricant mixtures has been developed based on applicable theory for the excess Gibbs energy of non-ideal solutions. In our approach, flexible thermodynamic forms are chosen to describe the properties of both the gas and liquid phases of refrigerant/lubricant mixtures. After an extensive study of models for describing non-ideal liquid effects, the Wohl-suffix equations, which have been extensively utilized in the analysis of hydrocarbon mixtures, have been developed into a general form applicable to mixtures where one component is a POE lubricant. In the present study we have analyzed several POEs where structural and thermophysical property data were available. Data were also collected from several sources on the solubility of refrigerant/lubricant binary pairs. We have developed a computer code (NISC), based on the Wohl model, that predicts dew point or bubble point conditions over a wide range of composition and temperature. Our present analysis covers mixtures containing up to three refrigerant molecules and one lubricant. The present code can be used to analyze the properties of R-410a and R-407c in mixtures with a POE lubricant. Comparisons with other models, such as the Wilson or modified Wilson equations, indicate that the Wohl-suffix equations yield more reliable predictions for HFC/POE mixtures.

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

    E-Print Network [OSTI]

    Zhu, H.

    2006-01-01

    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...

  8. Modeling of Refrigerant Flow Through Flexible Short Tube Orifices 

    E-Print Network [OSTI]

    Mohamed, Ramadan

    2000-01-01

    Single-phase flow of refrigerants R-22, R-13a, and R-41a through flexible short tube orifices with three different geometries and a range in upstream operating conditions was modeling using the finite element method, FEM. ...

  9. 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 and to install heat pumps in unoccupied spaces. Nevertheless manufacturers keep working on components for hydrocarbons. In the frame of a research project on heat pumps for simultaneous heating and cooling, an R407C

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

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S

    2014-01-01

    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%.

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

    SciTech Connect (OSTI)

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01

    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.

  12. 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.

    2006-01-01

    As a high-efficiency air conditioning scheme, the variable refrigerant flow (VRF) air-conditioning system is finding its way into medium-sized office buildings. Based on a generic dynamic building energy simulation environment, EnergyPlus, a new...

  13. 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 to improve industrial energy efficiency, the development of a high temperature heat pump using water vapor as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump

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

    E-Print Network [OSTI]

    Farzad, Mohsen

    1990-01-01

    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...

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

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

  16. 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 Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890, USA b Department of Electrical and Computer Engineering, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, PA 15213-3890, USA a r t i c

  17. 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)

    2014-01-29

    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.

  18. Exergy analysis of magnetic refrigeration

    E-Print Network [OSTI]

    Lucia, Umberto

    2010-01-01

    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.

  19. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G.W.

    1993-01-01

    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.

  20. Model solution State variable model: differential equation

    E-Print Network [OSTI]

    Limburg, Karin E.

    2/26/2014 1 Model solution State variable model: differential equation Models a rate of change equation General solution: the antiderivative Particular solution: require initial and boundary conditions up the general solution to a differential equation in a book Solve for initial and boundary

  1. Variable Refrigerant Flow Systems

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

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

  2. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking WithTelecentric viewingValidatingRoadmapVannevar Bush andCSVData

  3. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G W

    1992-01-01

    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.

  4. Malone refrigeration

    SciTech Connect (OSTI)

    Swift, G.W.

    1993-06-01

    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.

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

    E-Print Network [OSTI]

    Skogestad, Sigurd

    the compressor turbine. A forced draft air cooler is used to condense the HP refrigerant vapour, followed flash of saturated liquid letdown from the high pressure (HP) refrigerant receiver. The LP evaporator vessels differ by a factor of 5. The LP and IP evaporators are designed to provide adequate liquid

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

    E-Print Network [OSTI]

    Gupta, Ankush 1986-

    2012-09-27

    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

    2010-07-25

    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_hisolated 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. Thermoacoustic refrigeration

    SciTech Connect (OSTI)

    Garrett, S.L.; Hofler, T.J. )

    1992-12-01

    Shortly after their introduction, chlorofluorocarbons (CFCs) used as working fluids in a vapor compression (Rankine) refrigeration cycle became dominant in almost all small and medium-scale food refrigerator/freezer and building/residential air-conditioning applications. That situation is about to change dramatically and, at this moment, unpredictably. Two recent events are responsible for the new era in refrigeration that will dawn before the beginning of the 21st Century. The most significant of these is the international ban on the production of CFCs which were found to be destroying the Earth's protective ozone layer. The second event was the discovery of high temperature superconductors and the development of high speed and high density electronic circuits that require active cooling. It is the purpose of this article to introduce an entirely new approach to refrigeration that was first discovered in the early 1980s. This new approach-thermoacoustic refrigeration-uses high intensity sound waves to pump heat, with inert gases as the working fluid.

  9. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

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

    1992-12-22

    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.

  10. Superfluid thermodynamic cycle refrigerator

    DOE Patents [OSTI]

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

    1992-01-01

    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.

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

    E-Print Network [OSTI]

    Zevenhoven, Ron

    (Hvaporisation >> Hmelting), for example: water The Carnot power cycle can be executed in a reverse within the 8.11.2012Åbo Akademi Univ - Thermal and Flow Engineering - Piispankatu 8, 20500 Turku 3/64 The Carnot power cycle can be executed in a reverse within the saturation dome of a refrigerant fluid Reversed Carnot

  12. 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, a refrigeration cycle can be driven by heat (preferably 100-200°C) The replaces the compressor in a vapour to the surroundings in a d i th ttl d tcondenser, is throttled to low pressure and takes up heat in the evaporator

  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)

    1995-01-01

    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. 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.

    2004-01-01

    to an increase in the ambien perature above the system design point, a rigi rt-tube can sometimes provide a high enough flow e to flood the compressor with saturated refrigerant the other hand, when the condenser pressur . 1. Schematic of the flexible short...Pa were studied. Four upstream and downstream pressures were applied and the upstream subcooling was held at a constant value of 16.7 ?C. Mass flow rates from the numerical model were compared to available published experimental results. The study showed...

  15. 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)

    2007-09-11

    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.

  16. Fluorescent refrigeration

    DOE Patents [OSTI]

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

    1995-09-05

    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. 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

  18. PV output variability modeling using satellite imagery.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Ellis, Abraham; Reno, Matthew J.

    2010-11-01

    High frequency irradiance variability measured on the ground is caused by the formation, dissipation, and passage of clouds in the sky. If we can identify and associate different cloud types/patterns from satellite imagery, we may be able to predict irradiance variability in areas lacking sensors. With satellite imagery covering the entire U.S., this allows for more accurate integration planning and power flow modeling over wide areas. Satellite imagery from southern Nevada was analyzed at 15 minute intervals over a year. Methods for image stabilization, cloud detection, and textural classification of clouds were developed and tested. High Performance Computing parallel processing algorithms were also investigated and tested. Artificial Neural Networks using imagery as inputs were trained on ground-based measurements of irradiance to model the variability and were tested to show some promise as a means for predicting irradiance variability.

  19. Pearle's Hidden-Variable Model Revisited

    E-Print Network [OSTI]

    Richard D. Gill

    2015-05-19

    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.

  20. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1996-07-01

    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.

  1. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1999-01-01

    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.

  2. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1996-11-15

    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.

  3. Gray-box model for energy-efficient selection of set point hysteresis in heating, ventilation, air conditioning, and refrigeration controllers

    E-Print Network [OSTI]

    Bahrami, Majid

    Energy efficiency Gray-box model a b s t r a c t Many heating, ventilation, air conditioning by Heating, Ventilation, Air Conditioning, and Refrigeration (HVAC­R) systems [1]. HVAC­R energy consumption, for instance, may use up to 80% of the total energy consumed in the supermarket [3]. Moreover, Air Conditioning

  4. Control method for mixed refrigerant based natural gas liquefier

    DOE Patents [OSTI]

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

    2003-01-01

    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.

  5. Refrigeration system having standing wave compressor

    DOE Patents [OSTI]

    Lucas, Timothy S. (Glen Allen, VA)

    1992-01-01

    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.

    1994-05-27

    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.

    1999-01-01

    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. Multiscale modeling of spatially variable water and energy balance processes

    E-Print Network [OSTI]

    Famiglietti, J. S; Wood, E. F

    1994-01-01

    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

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

    E-Print Network [OSTI]

    Famiglietti, J. S; Wood, E. F

    1994-01-01

    AND WOOD: MULTISCALE WATER AND ENERGY BALANCE MODELING Wood,of spatially variable water and energy balance processes J.hydrological modeling. Water and energy balance models are

  10. Covered Product Category: Commercial Refrigerators and Freezers...

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

    assumptions: Assumes 24-ft3 capacity, vertical, solid-door refrigerators operated year round. The performance of the less efficient model just meets the U.S. Department of...

  11. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1997-02-01

    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.

  12. ARTI refrigerant database

    SciTech Connect (OSTI)

    Calm, J.M.

    1998-08-01

    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.

  13. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

    Vobach, A.R.

    1987-11-24

    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, A.R.

    1987-06-23

    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.

  15. Chemically assisted mechanical refrigeration process

    DOE Patents [OSTI]

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

    1987-01-01

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

    1987-01-01

    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.

  17. Numerical Simulation of Pulse-Tube Refrigerators: 1D model I.A. Lyulina1

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    of a piston, an aftercooler (AC), a regenerator, a cold heat exchanger (CHX), a tube, a hot heat exchanger numerical model has been introduced to study steady oscillatory heat and mass transfer in the tube section, numerical simulation, high resolution scheme 1 Introduction The pulse tube is a relatively new type

  18. ARTI Refrigerant Database

    SciTech Connect (OSTI)

    Calm, J.M.

    1992-04-30

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

  19. 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.

  20. Advances in refrigeration and heat transfer engineering

    SciTech Connect (OSTI)

    Bansal, Pradeep [ORNL; Cremaschi, Prof. Lorenzo [Oklahoma State University

    2015-01-01

    This special edition of Science and Technology for the Built Environment (STBE) presents selected high quality papers that were presented at the 15th International Refrigeration and Air Conditioning Conference held at Purdue University during July 14-17 2014. All papers went through the additional review before being finally accepted for publication in this special issue of Science and Technology and the Built Environment. Altogether 20 papers made to this special issue that cover a wide range of topics, including advancements in alternative refrigerants, heat exchangers/heat transfer, nano-fluids, systems design and optimization and modeling approaches. Although CO2 may perhaps have been the most researched and popular refrigerant in the past decade, R32 is being seriously considered lately as an alternative and environmentally friendly refrigerant for small systems due to its low Global Warming Potential (GWP).

  1. Nonparametric estimation of econometric models with categorical variables 

    E-Print Network [OSTI]

    Ouyang, Desheng

    2006-10-30

    shows that regression model with only discrete vari- ables differs significantly from the mixed discrete and continuous variables case. In the mixed variable case with at least one relevant continuous regressor, the irrele- vant variables can be smoothed... CV-based estimator has a high probability of smoothing out the irrele- vant variable, hence it leads to a more efficient (in finite samples) estimation result than the frequency estimator. It is interesting to observe that our nonparametric CV...

  2. High-Resolution Residential Feeder Load Characterization and Variability Modelling

    E-Print Network [OSTI]

    data. Ideally the method should be validated or updated with 1- second load data from the region-15-minute variability estimates for modeling dynamic load profiles. An autoregressive, AR(1) functionHigh-Resolution Residential Feeder Load Characterization and Variability Modelling Andrew Pohl, Jay

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

    E-Print Network [OSTI]

    Al-Majed, Abdulaziz Abdullah

    , 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 for simulating gas relatively high, near-constant, oil saturation in condensate reeervoir performance has been

  4. Thermoacoustic engines and refrigerators

    SciTech Connect (OSTI)

    Swift, G.

    1996-12-31

    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}.

  5. 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; Fricke, Brian A; Vineyard, Edward Allan

    2012-01-01

    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.

  6. Synchronous temperature rate control for refrigeration with reduced energy consumption

    DOE Patents [OSTI]

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Steven J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    Methods of operation for refrigerator appliance configurations with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper, and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The methods may include synchronizing alternating cycles of cooling each compartment to a temperature approximately equal to the compartment set point temperature by operation of the compressor, fans, damper and/or valve system. The methods may also include controlling the cooling rate in one or both compartments. Refrigeration compartment cooling may begin at an interval before or after when the freezer compartment reaches its lower threshold temperature. Freezer compartment cooling may begin at an interval before or after when the freezer compartment reaches its upper threshold temperature.

  7. Hybrid coupled models of the tropical Pacific: I interannual variability

    E-Print Network [OSTI]

    Tang, Youmin

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

  8. ARTI Refrigerant Database

    SciTech Connect (OSTI)

    Cain, J.M. , Great Falls, VA )

    1993-04-30

    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.

  9. Downhole pulse tube refrigerators

    SciTech Connect (OSTI)

    Swift, G.; Gardner, D.

    1997-12-01

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

  10. Energy Efficient, Environmentally Friendly Refrigerants 

    E-Print Network [OSTI]

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

    1998-01-01

    refrigerants have become expensive or unavailable. A safe, environmentally friendly, high performance refrigerant mixture for replacement of R-12 and R-134a has been developed. The mixture, designated Ikon B, is nonflammable, has zero ozone depletion potential...

  11. Waste Heat Recovery from Refrigeration 

    E-Print Network [OSTI]

    Jackson, H. Z.

    1982-01-01

    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...

  12. A Topography-Preserving Latent Variable Model with Learning Metrics

    E-Print Network [OSTI]

    Kaski, Samuel

    A Topography-Preserving Latent Variable Model with Learning Metrics Samuel Kaski and Janne grid to the input spa- ce. The mapping preserves the topography but measures local distances in terms

  13. Experimental Evaluation of Latent Variable Models for Dimensionality Reduction 

    E-Print Network [OSTI]

    Carreira-Perpinan, Miguel A; Renals, Steve

    1998-01-01

    We use electropalatographic (EPG) data as a test bed for dimensionality reduction methods based in latent variable modelling, in which an underlying lower dimension representation is inferred directly from the data. Several ...

  14. Studies of climate variability in a simple coupled model

    E-Print Network [OSTI]

    Abiven, Claude

    2007-01-01

    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 ...

  15. ARTI Refrigerant Database

    SciTech Connect (OSTI)

    Calm, J.M.

    1992-11-09

    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.

  16. Refrigeration monitor and alarm system

    SciTech Connect (OSTI)

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

    1986-09-23

    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.

  17. Ames Lab 101: Magnetic Refrigeration

    SciTech Connect (OSTI)

    Pecharsky, Vitalij

    2011-01-01

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

  18. Ames Lab 101: Magnetic Refrigeration

    ScienceCinema (OSTI)

    Pecharsky, Vitalij

    2013-03-01

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

  19. Internet Traffic Modeling Using the Index of Variability

    E-Print Network [OSTI]

    Kansas, University of

    traffic models: the Two-State Markov Modulated Poisson Process (MMPP) and the renewal process1 Internet Traffic Modeling Using the Index of Variability Georgios Y. Lazarou, Xiangdong Xia and is analytically tractable for many popular traffic models. Using this proposed measure, we then analyzed two

  20. Data Assimilation in Variable Dimension Dispersion Models using Particle Filters

    E-Print Network [OSTI]

    Singh, Tarunraj

    Data Assimilation in Variable Dimension Dispersion Models using Particle Filters K. V. Umamaheswara at Buffalo Buffalo, NY, U.S.A. peter@buffalo.edu Abstract-- Data assimilation in the context of puff based models usually lead to high dimensional space-gridded state space models. In the case of puff based

  1. 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

  2. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-05-26

    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.

  3. Thermoacoustic engines and refrigerators

    SciTech Connect (OSTI)

    Swift, G.W.

    1995-07-01

    We ordinarily think of a sound wave in a gas as consisting of coupled pressure and displacement oscillations. However, temperature oscillations always accompany the pressure changes. The combination of all these oscillations, and their interaction with solid boundaries, produces a rich variety of `thermoacoustic` effects. Although these effects as they occur in every-day life are too small to be noticed, one can harness extremely loud sound waves in acoustically sealed chambers to produce powerful heat engines, heat pumps and refrigerators. Whereas typical engines and refrigerators have crankshaft-coupled pistons or rotating turbines, thermoacoustic engines and refrigerators have at most a single flexing moving part (as in a loudspeaker) with no sliding seals. Thermoacoustic devices may be of practical use where simplicity, reliability or low cost is more important than the highest efficiency (although one cannot say much more about their cost-competitiveness at this early stage). This paper discusses the fundamentals of thermoacoustic engines and refrigerators, research in this field, and their commercial development. 16 refs., 5 figs.

  4. Design issues of a thermoacoustic refrigerator and its heat exchangers

    SciTech Connect (OSTI)

    Wetzel, M.; Herman, C.

    1996-12-31

    Thermoacoustic refrigeration is a fast advancing new refrigeration technology. Performance calculations indicate remarkable values for the thermoacoustic core of a thermoacoustic refrigerator. The thermoacoustic core is responsible for pumping heat from a cold to a hot temperature reservoir. However, the systems necessary to support the thermoacoustic core, such as heat exchangers and acoustic drivers are the weak points of this refrigeration technology. Particularly, heat exchangers were designed so far without any optimization. A reason for this is the lack of knowledge of the flow structures and heat transfer phenomena at the interface between the thermoacoustic core and the heat exchangers. For the purpose of gaining better insight, the authors built a thermoacoustic refrigerator model and applied visualization techniques, such as smoke injection and holographic interferometry, to visualize the flow and temperature fields at the interface.

  5. Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

    SciTech Connect (OSTI)

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

    2014-01-01

    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.

  6. Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

    SciTech Connect (OSTI)

    Bansal, Pradeep [ORNL; Shen, Bo [ORNL

    2015-01-01

    This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate 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. Among all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.

  7. The smallest refrigerators can reach maximal efficiency

    E-Print Network [OSTI]

    Paul Skrzypczyk; Nicolas Brunner; Noah Linden; Sandu Popescu

    2011-12-02

    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.

  8. Anisotropic Cosmological Model with Variable G and Lambda

    E-Print Network [OSTI]

    S. K. Tripathy; D. Behera; T. R. Routray

    2015-01-12

    Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar. The dynamics of the anisotropic universe with variable G and Lambda are discussed. Without assuming any specific forms for Lambda and the metric potentials, we have tried to extract the time variation of G and Lambda from the anisotropic model. The extracted G and Lambda are in conformity with the present day observation. Basing upon the observational limits, the behaviour and range of the effective equation of state parameter are discussed.

  9. Compact acoustic refrigerator

    SciTech Connect (OSTI)

    Bennett, G.A.

    1991-12-31

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

  10. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, Gloria A. (Los Alamos, NM)

    1992-01-01

    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.

  11. Compact acoustic refrigerator

    DOE Patents [OSTI]

    Bennett, G.A.

    1992-11-24

    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.

  12. Refrigerants in Transition 

    E-Print Network [OSTI]

    Stouppe, D. E.

    1991-01-01

    . 27-30. 7. Hayes, Floyd C., "Centrifugal\\~ater Chillers," CFCs: Today's Options Tomorrow's Solutions, ASHRAE Publication, Atlanta, GA, 1990, pp. 71-73. 8. Lorenz, Michael R., "CFCs: The Designer's Dilemma," Heating/Piping/Air Conditioning, April 1990... IN TRANSITION DAVID E. STOUPPE, P.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...

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

    E-Print Network [OSTI]

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

    1986-01-01

    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...

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

    SciTech Connect (OSTI)

    Beshr, Mohamed; Aute, Vikrant; Abdelaziz, Omar; Fricke, Brian A; Radermacher, Reinhard

    2014-01-01

    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.

  15. Separation of variables for the classical and quantum Neumann model

    E-Print Network [OSTI]

    O. Babelon; M. Talon

    1992-01-16

    The method of separation of variables is shown to apply to both the classical and quantum Neumann model. In the classical case this nicely yields the linearization of the flow on the Jacobian of the spectral curve. In the quantum case the Schr\\"odinger equation separates into one--dimensional equations belonging to the class of generalized Lam\\'e differential equations.

  16. Magnetic Refrigeration | GE Global Research

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

    and it will become hotter. Move it away (demagnetization) and the food cools down. GE researchers predict the cooling refrigerators could reduce energy consumption by 20%, in...

  17. Synchronous temperature rate control and apparatus for refrigeration with reduced energy consumption

    DOE Patents [OSTI]

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Steven J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    A refrigerator appliance configuration, and associated methods of operation, for an appliance with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper, and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The controller, by operation of the compressor, fans, damper and/or valve system, depending on the appliance configuration, synchronizes alternating cycles of cooling each compartment to a temperature approximately equal to the compartment set point temperature.

  18. Continuous-Variable Protocols in the Noisy-Storage Model

    E-Print Network [OSTI]

    Fabian Furrer; Christian Schaffner; Stephanie Wehner

    2015-09-30

    We present the first protocol for oblivious transfer that can be implemented with an optical continuous-variable system, and prove its security in the noisy-storage model. This model allows security to be achieved by sending more quantum signals than an attacker can reliably store at one specific point during the protocol. Concretely, we determine how many signals need to be sent in order to achieve security by establishing a trade-off between quantum uncertainty generated in the protocol and the classical capacity of the memory channel. As our main technical tool, we study and derive new uncertainty relations for continuous-variable systems. Finally, we provide explicit security parameters for realistic memory models.

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

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

    Low-Emission Refrigeration System Research & Development Roadmap: Next-Generation Low Global Warming Potential Refrigerants Energy Savings Potential and RD&D Opportunities for...

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

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

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

  1. 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...

  2. New Advanced Refrigeration Technology Provides Clean Energy,...

    Office of Environmental Management (EM)

    Refrigeration Technology Provides Clean Energy, Low Utility Bills for Supermarkets New Advanced Refrigeration Technology Provides Clean Energy, Low Utility Bills for...

  3. Helium dilution refrigeration system

    DOE Patents [OSTI]

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

    1988-01-01

    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.

  4. Helium dilution refrigeration system

    DOE Patents [OSTI]

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

    1988-09-13

    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.

  5. General Guidelines for the Disposal of Refrigerators, Freezers, and other Refrigeration Abandon or dispose of refrigerators, freezers, or window air conditioning units in

    E-Print Network [OSTI]

    Cina, Jeff

    not Abandon or dispose of refrigerators, freezers, or window air conditioning units in dumpsters or in common working and nonworking household refrigeration units (refrigerators, freezers, window air conditioning

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

    SciTech Connect (OSTI)

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

    2012-05-08

    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.

  7. Cryogenic refrigeration apparatus

    DOE Patents [OSTI]

    Crunkleton, James A. (Cambridge, MA)

    1992-01-01

    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. Cryogenic refrigeration apparatus

    DOE Patents [OSTI]

    Crunkleton, J.A.

    1992-03-31

    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.

  9. Performance bound for quantum absorption refrigerators

    E-Print Network [OSTI]

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

    2013-04-29

    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.

  10. Parameter spaces and design optimization of thermoacoustic refrigerators

    SciTech Connect (OSTI)

    Wetzel, M.; Herman, C.

    1996-12-31

    In the last two decades thermoacoustic refrigerators were developed in research laboratories with the goal to understand the basic physics and thermodynamics of thermoacoustic heat pumping. These research efforts led to a good understanding of this new environmentally safe refrigeration technology that employs acoustic power to pump heat. Consequently the next step is to improve and optimize the performance of thermoacoustic refrigerators and seek commercial applications. For this purpose, the need for fast and simple engineering estimates arises. By implementing the simplified linear model of thermoacoustic refrigerators--the short stack boundary layer approximation--such design estimates were derived and presented in this paper in the form of a design algorithm. Calculations obtained with this algorithm predict values for the Coefficient Of Performance (COP) of the order of 5 to 6. These values cannot be achieved at this time because of loss mechanisms in key parts of the thermoacoustic refrigerator, which are not quite understood yet. Nevertheless, these values are encouraging and gaining a better understanding of these loss mechanisms will be a big step towards the commercial market for this new environmentally safe refrigeration technology.

  11. 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.

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

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01

    index: Analysis and statistics. Solar Energy. 81, 195-206.Proc. of International Solar Energy World Congress, Kassel,irradiance variability. Solar Energy. 85, 1343-1353. Perez,

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

    E-Print Network [OSTI]

    Lave, Matthew; Kleissl, Jan

    2013-01-01

    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

  14. 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

  15. USING CLOUD CLASSIFICATION TO MODEL SOLAR VARIABILITY Matthew J. Reno

    E-Print Network [OSTI]

    With increasing amounts of solar energy on the electric grid, understanding the solar variability for different applications for predicting variability or ramp rates at locations with PV plants. For example, if the cloud dispatch could be controlled based on the expected variability and ramp rates from solar power plants

  16. Design of Industrial Process Refrigeration Systems 

    E-Print Network [OSTI]

    Witherell, W. D.

    1987-01-01

    of Cascade Refrigeration and Liquefaction Systems", Industrial Engineering Chemicals, Process Des. Develop., Vol. 13, No.4, 1974, pp. 421-433. 5. Cheng, W.B., and Mah, R.S.H., "Interactive Synthesis of Cascade Refrigeration Systems", Indus trial...

  17. 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.

  18. Thermoelectric refrigerator having improved temperature stabilization means

    DOE Patents [OSTI]

    Falco, Charles M. (Woodridge, IL)

    1982-01-01

    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.

  19. A latent-variable modelling approach to the acoustic-to-articulatory mapping problem. I 

    E-Print Network [OSTI]

    Carreira-Perpinan, Miguel A; Renals, Steve

    1999-01-01

    We present a latent variable approach to the acoustic-to-articulatory mapping problem, where different vocal tract configurations can give rise to the same acoustics. In latent variable modelling, the combined acoustic and ...

  20. Clustering South African Households Based on their Asset Status Using Latent Variable Models.

    E-Print Network [OSTI]

    Washington at Seattle, University of

    Clustering South African Households Based on their Asset Status Using Latent Variable Models into homogeneous groups based on their asset status. A model-based approach to clustering, based on latent variable and the models are combined to produce a hybrid model capable of handling mixed data types. Further, a mixture

  1. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1982-01-20

    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.

  2. Wheel-type magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, J.A.

    1983-10-11

    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.

  3. Ternary Dy-Er-Al magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-07-25

    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.

  4. Natural Refrigerant, Geothermal Heating & Cooling Solutions

    E-Print Network [OSTI]

    properties Kilmarnock Scotland demonstration History of Carbon Dioxide (R744) as Refrigerant CO2 proposed · Introduction to Thar Geothermal · Carbon Dioxide (R744) the Environmentally Exceptional Refrigerant · Thar Scale, Direct Exchange Design Carbon Dioxide (co2) R744 the Safe & Natural Refrigerant #12;150 Gamma

  5. Load Forecasting of Supermarket Refrigeration

    E-Print Network [OSTI]

    @compute.dtu.dk www.compute.dtu.dk M.Sc.-2013-87 #12;Summary (English) The Danish power production coming from energy system. Observed refrigeration load and local ambient temperature from a Danish su- permarket renewable energy, is increasing, therefore a flexible energy system is needed. In the present Thesis

  6. A recuperative superfluid stirling refrigerator

    SciTech Connect (OSTI)

    Brisson, J.G.; Swift, G.W.

    1993-07-01

    A superfluid Stirling refrigerator has been built with a counterflow heat exchanger serving as a recuperative regenerator. It has achieved temperatures of 296 mK with a 4% {sup 3}He-{sup 4}He mixture. Cooling power versus temperature and speed is presented for a 6.6% mixture.

  7. Low-temperature magnetic refrigerator

    DOE Patents [OSTI]

    Barclay, John A. (Los Alamos, NM)

    1985-01-01

    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.

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

    E-Print Network [OSTI]

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

    2013-01-01

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

  9. Modelling credit risk of small and medium sized enterprises using transactional, accounting and market variables 

    E-Print Network [OSTI]

    Ma, Yigui

    2012-06-26

    This thesis comprehensively explores the credit risk of Small and Medium Sized Enterprises (SMEs) using transactional characteristics, financial variables and market information. It contributes SMEs credit risk modelling ...

  10. Modeling Variability and Uncertainty of Photovoltaic Generation: A Hidden State Spatial Statistical Approach

    E-Print Network [OSTI]

    Tabone, Michaelangelo D; Callaway, Duncan S

    2015-01-01

    for grid-connected photovoltaic system based on advancedof many photovoltaic power generation systems dis- persed inSYSTEMS Modeling Variability and Uncertainty of Photovoltaic

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    and W. David Lee Arthur D. Little, Inc. Abstract This paper describes the development of an energy in the design phase, a computer model was developed by Arthur D. Little, Inc. to simulate the cabinet Refrigeration, Inc., and Arthur D. Little, Inc. In combination, these seven design options were estimated

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

    E-Print Network [OSTI]

    Famiglietti, JS; Wood, EF

    1994-01-01

    MULTISCALE WATER AND ENERGY BALANCE MODELING Wood, E. F. ,MULTISCALE WATER AND ENERGY BALANCE MODELING cess runoff,models of water and energy balance, Ph.D. dissertation,

  13. Synchronous compartment temperature control and apparatus for refrigeration with reduced energy consumption

    DOE Patents [OSTI]

    Gomes, Alberto Regio; Keres, Stephen L.; Kuehl, Stephen J.; Litch, Andrew D.; Richmond, Peter J.; Wu, Guolian

    2015-09-22

    A refrigerator appliance configuration, and associated methods of operation, for an appliance with a controller, a condenser, at least one evaporator, a compressor, and two refrigeration compartments. The configuration may be equipped with a variable-speed or variable-capacity compressor, variable speed evaporator or compartment fans, a damper and/or a dual-temperature evaporator with a valve system to control flow of refrigerant through one or more pressure reduction devices. The controller, by operation of the compressor, fans, damper and/or valve system, depending on the appliance configuration, controls the cooling rate in one or both compartments to synchronize, alternating cycles of cooling the compartments to their set point temperatures.

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

    SciTech Connect (OSTI)

    Ardhapurkar, P. M.; Sridharan, Arunkumar; Atrey, M. D.

    2014-01-29

    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.

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

    E-Print Network [OSTI]

    Scheichl, Robert

    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

  16. 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 Risø National Laboratory Vestas Wind Systems A/S #12;#12;I Modelling and Analysis of Variable Speed Wind Turbines with Induction Generator during Grid Fault by Sigrid M. Bolik Institute of Energy

  17. THE DUST RING OF LUMINOUS BLUE VARIABLE CANDIDATE HD 168625: INFRARED OBSERVATIONS AND MODEL CALCULATIONS1

    E-Print Network [OSTI]

    Speck, Angela Karen

    THE DUST RING OF LUMINOUS BLUE VARIABLE CANDIDATE HD 168625: INFRARED OBSERVATIONS AND MODEL surrounding the luminous blue variable (LBV) candidate HD 168625, together with new temperature and optical energy distribution of the dust. Therefore, HD 168625 is an excellent example of proposed models of LBV

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

    E-Print Network [OSTI]

    Wang, Jin

    Modeling and Generating Daily Changes in Market Variables Using A Multivariate Mixture of Normal of the normal distribution for modeling of daily changes in market variables with fatter-than-normal tails is to transform (linearly) a multivariate normalwith an input covariance matrix into the desired multivariate

  19. PV Output Variability Modeling Using Satellite Imagery and Neural Matthew J. Reno1,2

    E-Print Network [OSTI]

    PV Output Variability Modeling Using Satellite Imagery and Neural Networks Matthew J. Reno1, Albuquerque, NM, USA Abstract -- Variability and ramp rates of PV systems are increasingly important to understand and model for grid stability as PV penetration levels rise. Using satellite imagery to identify

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

    E-Print Network [OSTI]

    Luckyanova, Maria N. (Maria Nickolayevna)

    2008-01-01

    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 ...

  1. Energy Efficient Commercial Refrigeration with Carbon Dioxide Refrigerant and Scroll Expanders

    SciTech Connect (OSTI)

    Dieckmann, John

    2013-04-04

    Current supermarket refrigeration systems are built around conventional fluorocarbon refrigerants – HFC-134a and the HFC blends R-507 and R404A, which replaced the CFC refrigerants, R-12 and R-502, respectively, used prior to the Montreal Protocol phase out of ozone depleting substances. While the HFC refrigerants are non-ozone depleting, they are strong greenhouse gases, so there has been continued interest in replacing them, particularly in applications with above average refrigerant leakage. Large supermarket refrigeration systems have proven to be particularly difficult to maintain in a leak-tight condition. Refrigerant charge losses of 15% of total charge per year are the norm, making the global warming impact of refrigerant emissions comparable to that associated with the energy consumption of these systems.

  2. Logistic Regression Models In the linear regression model X + , there are two types of variables explanatory variables 1 2, ,.., kX X X

    E-Print Network [OSTI]

    Shalabh

    1 Chapter 14 Logistic Regression Models In the linear regression model X + , there are two types two possible values 0 and 1. In such a case, the logistic regression is used. For example, y can function of a random variable. In particular, the logistic distribution, whose cumulative distribution

  3. 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

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

    SciTech Connect (OSTI)

    Nohtomi, Makoto; Katsuta, Masafumi

    1999-07-01

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

  5. 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

    2011-08-15

    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.

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

    E-Print Network [OSTI]

    Bahrami, Majid

    COP W Q COP , , The Reversed Carnot Cycle Reversing the Carnot cycle does reverse the directions of heat and work interactions. A refrigerator or heat pump that operates on the reversed Carnot cycle refrigerator. The reversed Carnot cycle is the most efficient refrigeration cycle operating between two

  7. Working Fluids Low Global Warming Potential Refrigerants

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

    by 50% compared to today's best common practice - Alternative refrigerants with low global warming potential (GWP) are needed to achieve these goals - Provide guidance to the...

  8. 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.

  9. Natural Refrigerant (R-729) Heat Pump

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

    Natural Refrigerant (R-729) Heat Pump 2014 Building Technologies Office Peer Review New Project Lee Jestings (lee@S-RAM.com), Project Summary Timeline: Key Partners: Start date:...

  10. Multi-stage Cascaded Stirling Refrigerator

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

    Level: 7 - Full system prototype tested in a controlled environment Patent Status: Thermoacoustic Refrigerators and Engines Comprising Cascading Stirling Thermodynamic Units, US...

  11. Miniaturized Air-to-Refrigerant Heat Exchangers

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

    kW air-to-water and air-to- refrigerant heat exchangers Investigate conventional and additive manufacturing techniques Analyze system level performance of novel heat...

  12. High Efficiency Low Emission Refrigeration System

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

    Efficiency Low Emission Refrigeration System 2014 Building Technologies Office Peer Review Brian Fricke, frickeba@ornl.gov Oak Ridge National Laboratory Project Summary Timeline:...

  13. Miniaturized Air to Refrigerant Heat Exchangers | Department...

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

    in ORNL's Building Technologies Research & Integration Center. Working Fluids Low Global Warming Potential Refrigerants Improving Data Center Efficiency with Rack or Row...

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

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

    beverage vending machines are the General Services Administration (GSA) and Defense Logistics Agency (DLA). GSA sells refrigerated beverage vending machines through its...

  15. Development and Evaluation of a Sandia Cooler-based Refrigerator Condenser

    SciTech Connect (OSTI)

    Johnson, Terry A.; Kariya, Harumichi Arthur; Leick, Michael T.; Zimmerman, Mark D.; Li, Manjie; Du, Yilin; Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard

    2015-07-01

    This report describes the first design of a refrigerator condenser using the Sandia Cooler, i.e. air - bearing supported rotating heat - sink impeller. The project included ba seline performance testing of a residential refrigerator, analysis and design development of a Sandia Cooler condenser assembly including a spiral channel baseplate, and performance measurement and validation of this condenser system as incorporated into the residential refrigerator. Comparable performance was achieved in a 60% smaller volume package. The improved modeling parameters can now be used to guide more optimized designs and more accurately predict performance.

  16. Variable horizon model predictive control: robustness and optimality

    E-Print Network [OSTI]

    Shekhar, Rohan Chandra

    2012-07-03

    . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 6.3 Kinematic vectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 6.4 Mechanism model showing generalised coordinates . . . . . . . . . . . . . . . . 109 6.5 Static balance of material failure forces... .1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 6.1.1 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 6.2 Mechanism Model...

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

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

    Refrigerants Working Fluids Low Global Warming Potential Refrigerants Brian Fricke conducts research in ORNL's Building Technologies Research & Integration Center. Brian Fricke...

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

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

    Refrigerants - 2013 Peer Review Working Fluids Low Global Warming Potential Refrigerants - 2013 Peer Review Emerging Technologies Project for the 2013 Building Technologies...

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

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

    Global Warming Potential Refrigerants - 2013 Peer Review Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants - 2013 Peer Review Emerging Technologies Project for...

  20. Alternative Refrigerant Evaluation for High-Ambient-Temperature...

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

    for Low-GWP Refrigerants aims to develop an understanding of the performance of lower global warming potential (low-GWP) alternative refrigerants to hydrochlorofluorocarbon...

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

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

    Global-Warming-Potential Refrigerants Thermodynamic Evaluation of Low-Global-Warming-Potential Refrigerants Lead Performer: National Institute of Standards and Technology -...

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

    Energy Savers [EERE]

    Cooler relative to current heat exchanger technology are additional refrigerated space, noise reduction, and fouling reduction. Additional refrigerated volume realized by the more...

  3. 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...

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

    E-Print Network [OSTI]

    Fridley, David

    2008-01-01

    Urban Refrigerator Stocks, 1990-2006 5 Figure 3 China's Energy Information Label for Refrigerators.. 6 Figure 4 China's Voluntary Energy Efficiency

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

    Office of Environmental Management (EM)

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

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

    Energy Savers [EERE]

    HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL (HARDI) HEATING, AIR-CONDITIONING AND REFRIGERATION DISTRIBUTORS INTERNATIONAL (HARDI) OE Framework Document...

  7. 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...

  8. Low-Cost Electrochemical Compressor Utilizing Green Refrigerants...

    Office of Environmental Management (EM)

    Low-Cost Electrochemical Compressor Utilizing Green Refrigerants for HVAC Applications Low-Cost Electrochemical Compressor Utilizing Green Refrigerants for HVAC Applications...

  9. 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...

  10. Alternative Refrigerant Evaluation for High-Ambient-Temperature...

    Office of Environmental Management (EM)

    Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners Alternative Refrigerant Evaluation for...

  11. 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

  12. Seven-effect absorption refrigeration

    DOE Patents [OSTI]

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

    1989-05-09

    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.

  13. 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

    2004-08-30

    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.

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

    SciTech Connect (OSTI)

    Johnson, Francis

    2014-06-30

    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.

  15. Validating the BHR RANS model for variable density turbulence

    SciTech Connect (OSTI)

    Israel, Daniel M [Los Alamos National Laboratory; Gore, Robert A [Los Alamos National Laboratory; Stalsberg - Zarling, Krista L [Los Alamos National Laboratory

    2009-01-01

    The BHR RANS model is a turbulence model for multi-fluid flows in which density variation plays a strong role in the turbulence processes. In this paper they demonstrate the usefulness of BHR over a wide range of flows which include the effects of shear, buoyancy, and shocks. The results are in good agreement with experimental and DNS data across the entire set of validation cases, with no need to retune model coefficients between cases. The model has potential application to a number of aerospace related flow problems.

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

    E-Print Network [OSTI]

    Furr, James C., Jr

    2007-09-17

    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...

  17. 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

  18. Modeling Variability and Uncertainty of Photovoltaic Generation: A Hidden State Spatial Statistical Approach

    E-Print Network [OSTI]

    Tabone, Michaelangelo D; Callaway, Duncan S

    2015-01-01

    Solar Data for Power System Modeling From Static Spatial Variability Anal- ysis, National Renewable Energydata for isolated sites: Using artificial neural network and a library of Markov transition matrices approach,” Solar Energy

  19. Counterflow absorber for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01

    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.

  20. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

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

    1985-01-01

    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.

  1. Oil cooled, hermetic refrigerant compressor

    DOE Patents [OSTI]

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

    1985-05-14

    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.

  2. Novel materials for laser refrigeration

    SciTech Connect (OSTI)

    Hehlen, Markus P

    2009-01-01

    The status of optical refrigeration of rare-earth-doped solids is reviewed, and the various factors that limit the performance of current laser-cooling materials are discussed. Efficient optical refrigeration is possible in materials for which {Dirac_h}{omega}{sub max} < E{sub p}/8, where {Dirac_h}{omega}{sub max} is the maximum phonon energy of the host material and E{sub p} is the pump energy of the rare-earth dopant. Transition-metal and OH{sup -}impurities at levels >100 ppb are believed to be the main factors for the limited laser-cooling performance in current materials. The many components of doped ZBLAN glass pose particular processing challenges. Binary fluoride glasses such as YF{sub 3}-LiF are considered as alternatives to ZBLAN. The crystalline system KPb{sub 2}CI{sub 5} :Dy{sup 3+} is identified as a prime candidate for high-efficiency laser cooling.

  3. 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 developed a sequential model to predict the coupled thermo-hydraulic processes at a cell-scale radioactive

  4. Limited Dependent Variable Correlated Random Coefficient Panel Data Models 

    E-Print Network [OSTI]

    Liang, Zhongwen

    2012-10-19

    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...

  5. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Boeder, A; Zimm, C

    2006-09-30

    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.

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

    DOE Patents [OSTI]

    DeVault, Robert C. (Knoxville, TN)

    1995-01-01

    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.

  7. Refrigerant charge management in a heat pump water heater

    DOE Patents [OSTI]

    Chen, Jie; Hampton, Justin W.

    2014-06-24

    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.

  8. Bearing construction for refrigeration compresssor

    DOE Patents [OSTI]

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

    1988-01-01

    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.

  9. Solid-Vapor Sorption Refrigeration Systems 

    E-Print Network [OSTI]

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

    1991-01-01

    sorption media. 'i: ! 60 1 60 I 40 SO I 20 a 10 J 0 CC48G-1110 AclivallJd carbon Uquld-II0p0r ~OO-1300 Zealllll Figure 2. Useable refrigerant densities. Summarizing, complex compound exhibit inherent characteristics which make them ideal... refrigerant density than is attainable with any other sorption media. Figure 2 shows usable refrigerant densities for complex compounds and other sorption media. 'i: ! 80 60 1 40 SO 20 a 10 J 0 CC48G-1110 AcIivallld carbon Uqukl-II0p0r ~OO-1300Zaalllll Figure...

  10. Conserving Energy in Blast Freezers Using Variable Frequency Drives 

    E-Print Network [OSTI]

    Kolbe, E.; Ling, Q.; Wheeler, G.

    2004-01-01

    ,280 cfm. This might fall by 25% in a fully loaded room. Fan motors were nominal 7-1/2 HP inverter-duty models manufactured by Baldor. Refrigeration System An engine roo m dedicated to freezing operations had a total capacity intended to meet... Baldor Model ID15H430-EO, rated for a 40 HP variable torque load. Other significant components were: - The enclosure; - A ?choke? or line reactor on the incoming line to the VFD. This serves two purposes: it protects the VFD electronics from...

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

    E-Print Network [OSTI]

    Sanders, Seth

    Simplified Modelling and Control of a Synchronous Machine with Variable­Speed Six­Step Drive on simple and intuitive techniques for the modelling of synchronous machines and their associated control design process for synchronous machines. What the two techniques have in common is a reliance

  12. A stochastic model of fatigue crack propagation under variable-amplitude loading

    E-Print Network [OSTI]

    Ray, Asok

    -space model of fatigue crack propagation under variable-amplitude loading. The (non-stationary) statistic. Introduction Fatigue crack analysis is an essential tool for life prediction and maintenance of machinery/strain) factor b a constant model parameter larger than 1 (I 10) d increment operator DS eective stress range W 2

  13. A depth-derived Pleistocene age model: Uncertainty estimates, sedimentation variability, and nonlinear climate change

    E-Print Network [OSTI]

    Wunsch, Carl

    A depth-derived Pleistocene age model: Uncertainty estimates, sedimentation variability. To avoid biasing this ``depth-derived'' age estimate, the depth scale is first corrected for the effects sediment accumulation rates are estimated and modeled as an autocorrelated stochastic process. Depth-derived

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

    SciTech Connect (OSTI)

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

    2012-01-01

    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.

  15. 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

    2013-11-14

    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.

  16. Defrost Temperature Termination in Supermarket Refrigeration Systems

    SciTech Connect (OSTI)

    Fricke, Brian A; Sharma, Vishaldeep

    2011-11-01

    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.

  17. 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.

  18. 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.

  19. 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.

  20. Loveland Water & Power- Refrigerator Recycling Program

    Broader source: Energy.gov [DOE]

    Loveland Water & Power is providing an incentive for customers to recycle older, working refrigerators. Interested customers can call the utility to arrange a time to pick up the old...

  1. Combined cold compressor/ejector helium refrigerator

    DOE Patents [OSTI]

    Brown, D.P.

    1984-06-05

    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.

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

    SciTech Connect (OSTI)

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

    1997-12-01

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

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

    E-Print Network [OSTI]

    Zuo, Z.; Hu, W.

    2006-01-01

    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...

  4. Variable Selection in Data Mining: Building a Predictive Model for Bankruptcy

    E-Print Network [OSTI]

    Stine, Robert A.

    Variable Selection in Data Mining: Building a Predictive Model for Bankruptcy Dean P. Foster and Robert A. Stine Department of Statistics The Wharton School of the University of Pennsylvania consequences of over-fitting (e.g. ?). Many in- teresting problems, particularly classification problems

  5. 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

  6. Ancillary Statistics In a parametric model f (y; ) for a random variable

    E-Print Network [OSTI]

    Reid, Nancy

    Ancillary Statistics In a parametric model f (y; ) for a random variable or vector Y, a statistic A = a(Y) is ancillary for if the distribution of A does not depend on . As a very simple example, if Y is determined randomly, rather than being fixed in advance, then A = number of observations in Y is an ancillary

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

    E-Print Network [OSTI]

    Grizzle, Jessy W.

    Control-Oriented Model of a Dual Equal Variable Cam Timing Spark Ignition Engine A. G of min- imizing exhaust emissions, providing increased fuel economy and satisfying driver perfor- mance that provides a tradeo among idle stability, fuel economy, and maximum torque performance. There are also

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

    E-Print Network [OSTI]

    Cs. Asszonyi; T. Fülöp; P. Ván

    2014-10-22

    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.

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

    E-Print Network [OSTI]

    Asszonyi, Cs; Ván, P

    2014-01-01

    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.

  10. SMALL-SCALE VARIABILITY IN SEA SURFACE HEIGHTS AND SURFACE WINDS: IMPLICATIONS FOR ERRORS IN OCEAN MODELS AND OBSERVATIONS

    E-Print Network [OSTI]

    Kaplan, Alexey

    SMALL-SCALE VARIABILITY IN SEA SURFACE HEIGHTS AND SURFACE WINDS: IMPLICATIONS FOR ERRORS IN OCEAN on dispersion relationship of planetary waves 4. Small-scale variability in surface winds and sea surface of model and observational data sets. Imperfect parameterization of the small-scale variability (SSV

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

    E-Print Network [OSTI]

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

    1995-08-17

    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.

  12. Quantum heat engines and refrigerators: Continuous devices

    E-Print Network [OSTI]

    Ronnie Kosloff; Amikam Levy

    2013-10-02

    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.

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

    E-Print Network [OSTI]

    Wilson, Benton Wade

    2004-09-30

    of the new model (t (? p /? tD D D) for- mulation (Eq. 1.6)). Solution is plotted versus the inverse of the modified Boltzmann transform variable 2DDD r 10 In Fig. 1.4 we present the radial derivative function pDdr(? D) function plotted versus... the modified Boltzmann transform variable The p2 DDD t Ddr(? D) formulation represents the change in pressure drop with respect to radius as we move out into the reservoir ? clearly there are separate factors at issue ? the behavior of the |rD(? pD/? r...

  14. High power thermoacoustic refrigeration. Annual summary report, 1 June 1995-31 May 1996

    SciTech Connect (OSTI)

    Garrett, S.L.

    1996-06-15

    The purpose of this research project is to study the fundamental physical processes which are involved in production of high cooling powers from electrically driven thermoacoustic refrigeration. The results of these experimental investigations are then utilized to produce improved designs for the next generation of high power thermoacoustic refrigerators, chillers, and air conditioners. These research objectives are achieved by an integrated combination of experimental measurements on thermoacoustic components and subsystems, as well as complete refrigeration systems. Comparison of the measured performance to analytic models based on differential equations (low amplitude) and similitude (high amplitude) and to numerical models based on the Los Alamos National Laboratory Design Environment for Low-Amplitude ThermoAcoustic Engines (DELTA-E), are then made.

  15. Energy Savings from Floating Head Pressure in Ammonia Refrigeration Systems 

    E-Print Network [OSTI]

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

    1998-01-01

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

  16. Refrigerant pressurization system with a two-phase condensing ejector

    DOE Patents [OSTI]

    Bergander, Mark (Madison, CT)

    2009-07-14

    A refrigerant pressurization system including an ejector having a first conduit for flowing a liquid refrigerant therethrough and a nozzle for accelerating a vapor refrigerant therethrough. The first conduit is positioned such that the liquid refrigerant is discharged from the first conduit into the nozzle. The ejector includes a mixing chamber for condensing the vapor refrigerant. The mixing chamber comprises at least a portion of the nozzle and transitions into a second conduit having a substantially constant cross sectional area. The condensation of the vapor refrigerant in the mixing chamber causes the refrigerant mixture in at least a portion of the mixing chamber to be at a pressure greater than that of the refrigerant entering the nozzle and greater than that entering the first conduit.

  17. 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

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

    E-Print Network [OSTI]

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

    2006-01-01

    In a mucilage glue fiber factory, the design of the refrigeration system takes into account the characteristics of mucilage glue fiber production and fully uses the refrigeration compressor heat to economize energy and reduce the production cost...

  19. Basics of Low-temperature Refrigeration

    E-Print Network [OSTI]

    Alekseev, A

    2014-01-01

    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.

  20. T N YORK, NEW YORKI AMERICAN SOCIETY OF HEATING, REFRIGERATING

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    lDC) r; T N YORK, NEW YORKI OF THE AMERICAN SOCIETY OF HEATING, REFRIGERATING /*s\\ TECHNICAL ANDITI

  1. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect (OSTI)

    Calm, James M.

    2000-09-30

    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.

  2. Energy Savings Potential and Research & Development Opportunities for Commercial Refrigeration

    SciTech Connect (OSTI)

    none,

    2009-09-01

    This study documents the energy consumption of commercial refrigeration equipment (CRE) in the U.S. and evaluated the energy savings potential of various technologies and energy efficiency measures that could be applied to such equipment. The study provided an overview of CRE applications, assessed the energy-savings potential of CRE in the U.S., outline key barriers to adoption of energy-savings technologies, and recommended opportunities for advanced energy saving technology research. The study was modeled after an earlier 1996 report by Arthur D. Little, Inc., and updated key information, examined more equipment types, and outlined long-term research and development opportunities.

  3. 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 (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single as a refrigerator Optimum cooling power is reached at V 2/e: Cooling power of a NIS junction: Temperature TN

  4. Method and apparatus for de-superheating refrigerant

    DOE Patents [OSTI]

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

    1997-11-25

    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.

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

    E-Print Network [OSTI]

    Demosthenes Kazanas

    2000-01-13

    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.

  6. Change of variables as a method to study general ?-models: Bulk universality

    SciTech Connect (OSTI)

    Shcherbina, M.

    2014-04-15

    We consider ? matrix models with real analytic potentials. Assuming that the corresponding equilibrium density ? has a one-interval support (without loss of generality ? = [?2, 2]), we study the transformation of the correlation functions after the change of variables ?{sub i} ? ?(?{sub i}) with ?(?) chosen from the equation ?{sup ?}(?)?(?(?)) = ?{sub sc}(?), where ?{sub sc}(?) is the standard semicircle density. This gives us the “deformed” ?-model which has an additional “interaction” term. Standard transformation with the Gaussian integral allows us to show that the “deformed” ?-model may be reduced to the standard Gaussian ?-model with a small perturbation n{sup ?1}h(?). This reduces most of the problems of local and global regimes for ?-models to the corresponding problems for the Gaussian ?-model with a small perturbation. In the present paper, we prove the bulk universality of local eigenvalue statistics for both one-cut and multi-cut cases.

  7. Circumpolar Deep Water Circulation and Variability in a Coupled Climate Model AGUS SANTOSO AND MATTHEW H. ENGLAND

    E-Print Network [OSTI]

    Santoso, Agus

    Circumpolar Deep Water Circulation and Variability in a Coupled Climate Model AGUS SANTOSO Deep Water (CDW) is analyzed using a long-term integration of a coupled climate model. The variability into the Southern Ocean via North Atlantic Deep Water (NADW). Salinity dipole anomalies appear to propagate around

  8. Moore et al. 1 Modeling the Impact of Traffic Conditions on the Variability of Mid-block Roadside Fine

    E-Print Network [OSTI]

    Bertini, Robert L.

    variables; additionally, the effects of vehicle types and wind direction were quantified. Modeling resultsMoore et al. 1 Modeling the Impact of Traffic Conditions on the Variability of Mid-block Roadside Fine Particulate Matter Concentrations on an Urban Arterial Adam Moore, adam.moore@pdx.edu* Miguel

  9. Convective Precipitation Variability as a Tool for General Circulation Model Analysis CHARLOTTE A. DEMOTT, DAVID A. RANDALL, AND MARAT KHAIROUTDINOV

    E-Print Network [OSTI]

    Collett Jr., Jeffrey L.

    Convective Precipitation Variability as a Tool for General Circulation Model Analysis CHARLOTTE A Precipitation variability is analyzed in two versions of the Community Atmospheric Model (CAM), the standard rainfall as soon as the boundary layer energizes. Precipitation is also concurrent with tropospheric

  10. 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

    2006-02-07

    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.

  11. 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.

  12. Improving Industrial Refrigeration System Efficiency - Actual Applications 

    E-Print Network [OSTI]

    White, T. L.

    1980-01-01

    in the booster pump suction line to prevent pump cavitation and to improve refrigeration cycle effi ciency. Por each lOOp of sUDcooling, cycle efficiency increases by about 2%. Approxi mately 20 0 p of subcooling is planned for the modified system...

  13. Measurements with a recuperative superfluid Stirling refrigerator

    SciTech Connect (OSTI)

    Watanabe, A.; Swift, G.W.; Brisson, J.G.

    1995-08-01

    A superfluid Stirling refrigerator cooled to 168 mK using a 4.9% {sup 3}He- {sup 4}He mixture and exhausting its waste heat at 383 mK. Cooling power versus temperature and speed is presented for 4.9%, 17%, and 36% mixtures. At the highest concentration, a dissipation mechanism of unknown origin is observed.

  14. Frontiers in thermoacoustic refrigeration and mixture separation

    E-Print Network [OSTI]

    conversion, which harnesses the oscillations of temperature, heat flux, pressure, and motion in intense sound-transfer and acoustic components and filled with a gas-- typically high-pressure helium. Refrigeration is produced because gas that oscillates through the cold heat exchanger is depressurized adiabatically on the pulse

  15. Ground Loops for Heat Pumps and Refrigeration 

    E-Print Network [OSTI]

    Braud, H. J.

    1986-01-01

    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...

  16. 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.

  17. Waste Heat Recapture from Supermarket Refrigeration Systems

    SciTech Connect (OSTI)

    Fricke, Brian A

    2011-11-01

    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.

  18. Computing supersonic non-premixed turbulent combustion by an SMLD flamelet progress variable model

    E-Print Network [OSTI]

    Coclite, A; Gurtner, M; De Palma, P; Haidnd, O J; Pascazio, G

    2015-01-01

    This paper describes the numerical simulation of the NASA Langley Research Center supersonic H2 -Air combustion chamber performed using two approaches to model the presumed probability density function (PDF) in the flamelet progress variable (FPV) framework. The first one is a standard FPV model, built presuming the functional shape of the PDFs of the mixture fraction, Z, and of the progress parameter, {\\Lambda}. In order to enhance the prediction capabilities of such a model in high-speed reacting flows, a second approach is proposed employing the statistically most likely distribution (SMLD) techcnique to presume the joint PDF of Z and {\\Lambda}, without any assumption about their behaviour. The standard and FPV-SMLD models have been developed using the low Mach number assumption. In both cases, the temperature is evaluated by solving the total-energy conservation equation, providing a more suitable approach for the simulation of supersonic combustion. By comparison with experimental data, the proposed SMLD...

  19. 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

    2015-01-01

    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 ...

  20. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; Primeau, F.

    2015-01-12

    Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a fact that is often omitted from biogeochemical ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observationalmore »data coverage and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C : N : P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model (CESM) and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr-1 (143 Tmol C yr-1, 16.4 Tmol N yr-1, and 1 Tmol P yr-1, respectively, with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. Dissolved organic carbon (DOC) export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less

  1. Variable C : N : P stoichiometry of dissolved organic matter cycling in the Community Earth System Model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Letscher, R. T.; Moore, J. K.; Teng, Y. -C.; Primeau, F.

    2014-06-16

    Dissolved organic matter (DOM) plays an important role in the ocean's biological carbon pump by providing an advective/mixing pathway for ~ 20% of export production. DOM is known to have a stoichiometry depleted in nitrogen (N) and phosphorus (P) compared to the particulate organic matter pool, a~fact that is often omitted from biogeochemical-ocean general circulation models. However the variable C : N : P stoichiometry of DOM becomes important when quantifying carbon export from the upper ocean and linking the nutrient cycles of N and P with that of carbon. Here we utilize recent advances in DOM observational data coveragemore »and offline tracer-modeling techniques to objectively constrain the variable production and remineralization rates of the DOM C / N / P pools in a simple biogeochemical-ocean model of DOM cycling. The optimized DOM cycling parameters are then incorporated within the Biogeochemical Elemental Cycling (BEC) component of the Community Earth System Model and validated against the compilation of marine DOM observations. The optimized BEC simulation including variable DOM C : N : P cycling was found to better reproduce the observed DOM spatial gradients than simulations that used the canonical Redfield ratio. Global annual average export of dissolved organic C, N, and P below 100 m was found to be 2.28 Pg C yr-1 (143 Tmol C yr-1), 16.4 Tmol N yr-1, and 1 Tmol P yr-1, respectively with an average export C : N : P stoichiometry of 225 : 19 : 1 for the semilabile (degradable) DOM pool. DOC export contributed ~ 25% of the combined organic C export to depths greater than 100 m.« less

  2. Mathematical and Computational Applications, Vol. 18, No. 3, pp. 408-420, 2013 MODELING AND CONTROL OF A VARIABLE SPEED

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    OF A VARIABLE SPEED VARIABLE PITCH ANGLE PROTOTYPE WIND TURBINE Sanem Evren, Mustafa Ünel and Mahmut F. Akit on modeling, control and simulation of a 500 horizontal axis prototype wind turbine that is being developed in the context of the MILRES (National Wind Energy Systems) Project in Turkey. The prototype turbine is designed

  3. 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

    2010-01-01

    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.

  4. Measurements of the efficiency and refrigeration power of pulse-tube refrigerators

    SciTech Connect (OSTI)

    Herrmann, S.; Radebaugh, R.

    1986-09-01

    Pulse-tube or thermoacoustic refrigerators have the potential for high reliability since they require only one moving part - an oscillating piston or diaphragm at room temperature. If a tube is closed at one end and connected to a pressure-wave generator at the open end, and if the phase angle between mass flow and pressure is shifted from 90/sup 0/, then refrigeration occurs at the open end. The shift in phase angle can be realized by thermal relaxation between the gas and the tube walls or by an orifice at the closed end. A low temperature of 60 K using helium gas in a one-stage orifice pulse tube has been achieved at NBS. The report describes the first measurements of the efficiency, refrigeration power, and refrigeration power per unit mass flow, for three pulse-tube refrigerators. Three tube sizes, differing in length and diameter, were studied over a frequency range of 3 to 11.5 Hz. Cooling efficiencies as high as 90% of the Carnot efficiency were obtained when compressor and regenerator losses are neglected.

  5. Generating Candidate Models Each variable li can identify a candidate model (a label).

    E-Print Network [OSTI]

    Toronto, University of

    , in our experiments. Fast Fusion Moves for Multi-Model Estimation Andrew Delong Olga Veksler Yuri Boykov. of the Royal Society A, 1998. V. Lempitsky, C. Rother, S. Roth, A. Blake. Fusion moves for markov random field Relaxation. CVPR 2007. H. N. Isack, Y. Boykov. Energy-based Geometric Multi-Model Fitting. IJCV 97

  6. 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)

    1990-01-01

    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.

  7. Theoretical evaluation of the optimal performance of a thermoacoustic refrigerator

    SciTech Connect (OSTI)

    Minner, B.L.; Braun, J.E.; Mongeau, L.G.

    1997-12-31

    Theoretical models were integrated with a design optimization tool to allow estimates of the maximum coefficient of performance for thermoacoustic cooling systems. The system model was validated using experimental results for a well-documented prototype. The optimization tool was then applied to this prototype to demonstrate the benefits of systematic optimization. A twofold increase in performance was predicted through the variation of component dimensions alone, while a threefold improvement was estimated when the working fluid parameters were also considered. Devices with a similar configuration were optimized for operating requirements representative of a home refrigerator. The results indicate that the coefficients of performance are comparable to those of existing vapor-compression equipment for this application. In addition to the choice of working fluid, the heat exchanger configuration was found to be a critical design factor affecting performance. Further experimental work is needed to confirm the theoretical predictions presented in this paper.

  8. Hydrophilic structures for condensation management in refrigerator appliances

    DOE Patents [OSTI]

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

    2014-10-21

    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.

  9. Microcomputer Software for Refrigerant Property and Cycle Analysis Calculations 

    E-Print Network [OSTI]

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

    1985-01-01

    .e., minimum temperature difference betweeD the refrigerant and the process stream) in the evapo rator and condenser on the energy utilization and cooling requirements for the refrigeration system. The assumed refrigeration load is 30 million Btu... on an existing system for purposes of improving energy utilization efficiency. Consider the case of a chiller for a commercial office building, operating on R12 at an evapo rator temperature of 42 deg F. During typical summer conditions, the chiller provides...

  10. Supermarket with Ground Coupled Carbon Dioxide Refrigeration Plant 

    E-Print Network [OSTI]

    Rehault, N.

    2012-01-01

    SUPERMARKET WITH GROUND COUPLED CARBON DIOXIDE REFRIGERATION PLANT Dipl.-Ing. Nicolas R?hault Fraunhofer Institute for Solar Energy Systems ISE ICEBO 2012 Manchester, 25.10.2012 ? Fraunhofer ISE 2 AGENDA 1. Background on supermarkets, energy...- conditioning: Insulation and air tightness to Passivhaus Standard CO2 refrigeration plant as only energy supply No use of fossil fuels Use of ground to sub-cool refrigerant and as heat source for heat pump Use of covers and night curtains LED...

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

    DOE Patents [OSTI]

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

    1998-04-28

    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.

  12. 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)

    1998-04-28

    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.

  13. Retrofitting Doors on Open Refrigerated Cases | Department of...

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

    - 2013 BTO Peer Review Better Buildings Alliance Equipment Performance Specifications - 2013 BTO Peer Review Working Fluids Low Global Warming Potential Refrigerants - 2013...

  14. Test results on a supercharged compressor for commercial refrigeration

    SciTech Connect (OSTI)

    Andrews, J.W.; Butcher, T.A.; Wilhelm, W.G. )

    1989-01-01

    This paper reports on a project whose objective was to quantify the technical benefits of using refrigerant R-502 in a supercharged reciprocating compressor for commercial refrigeration applications. The supercharged compressor concept used a special heat exchanger that subcools the major portion of the liquid refrigerant leaving the condenser. This subcooling is achieved by flashing the remaining portion of the condensed liquid through an expansion valve, thereby cooling it, and using it to absorb heat from the rest of the refrigerant. This supercharged stream is then fed to the cylinders through ports in the cylinder walls that are uncovered when the piston reaches bottom dead center.

  15. Development and Evaluation of a Sandia Cooler-based Refrigerator...

    Energy Savers [EERE]

    Radial Sandia Cooler Report Rotating heat exchangers installed in appliances and heat pumps have the potentially to reduce energy costs and refrigerant charge in a compact...

  16. 2014-04-10 Issuance: Test Procedures for Commercial Refrigeration...

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

    final rule regarding test procedures for commercial refrigeration equipment, as issued by the Deputy Assistant Secretary for Energy Efficiency on April 10, 2014. Though it is not...

  17. Acoustic recovery of lost power in pulse tube refrigerators

    SciTech Connect (OSTI)

    Swift, G.W.; Gardner, D.L.; Backhaus, S.

    1999-02-01

    In an efficient Stirling-cycle cryocooler, the cold piston or displacer recovers power from the gas. This power is dissipated into heat in the orifice of an orifice pulse tube refrigerator, decreasing system efficiency. Recovery of some of this power in a pulse tube refrigerator, without sacrificing the simplicity and reliability inherent in a system with no cold moving parts, is described in this paper. In one method of such power recovery, the hot ends of both the regenerator and the pulse tube are connected to the front of the piston driving the refrigerator. Experimental data is presented demonstrating this method using a thermoacoustic driver instead of a piston driver. Control of time-averaged mass flux through the refrigerator is crucial to this power recovery, lest the refrigerator{close_quote}s cooling power be overwhelmed by a room-temperature mass flux. Two methods are demonstrated for control of mass flux: a barrier method, and a hydrodynamic method based on turbulent irreversible flow. At {minus}55{degree}C, the refrigerator provided cooling with 9{percent} of the Carnot coefficient of performance. With straightforward improvements, similar refrigerators should achieve efficiencies greater than those of prior pulse tube refrigerators and prior standing-wave thermoacoustic refrigerators, while maintaining the advantages of no moving parts. {copyright} {ital 1999 Acoustical Society of America.}

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

    Office of Environmental Management (EM)

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

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

    Open Energy Info (EERE)

    Mexico Sectoral Study on Climate and Refrigeration Technology in Developing Countries and the Development of Methods and Instruments for Identifying Reduction Potential and...

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

    Open Energy Info (EERE)

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

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

    DOE Patents [OSTI]

    Jardine, Douglas M. (Colorado Springs, CO)

    1983-01-01

    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.

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

    DOE Patents [OSTI]

    Jardine, D.M.

    1983-03-22

    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.

  3. Energy Efficient Design, Retrofit and Control of Evaporative Condensers in Ammonia Refrigeration Systems

    E-Print Network [OSTI]

    Kissock, Kelly

    Energy Efficient Design, Retrofit and Control of Evaporative Condensers in Ammonia Refrigeration ABSTRACT Ammonia refrigeration systems typically offer many energy efficiency opportunities because efficiency of ammonia refrigeration systems. Introduction About 7.5% of the total manufacturing energy

  4. 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.

    1998-09-01

    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.

  5. 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.

    2007-03-20

    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.

  6. Changing Industrial Energy Behavior Via Education: Case Study of an Energy Efficiency Refrigeration Certification

    E-Print Network [OSTI]

    McClaren, Mersiha; Phoutrides, Steve; O'Neil, Nick; McRae, Marjorie

    2015-01-01

    refrigeration systems efficiently, while more executivesour refrigeration systems efficiently Middle manager (n=28)Value of Operating Equipment Efficiently Vendors are selling

  7. Changing Industrial Energy Behavior Via Education: Case Study of an Energy Efficiency Refrigeration Certification

    E-Print Network [OSTI]

    McClaren, Mersiha; Phoutrides, Steve; O'Neil, Nick; McRae, Marjorie

    2015-01-01

    Changing Industrial Energy Behavior Via Education: Casewith the operation of industrial refrigeration plants,aim was to encourage industrial refrigeration professionals

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    Technologies3 Achema 2012 // heat pumps using ammonia Industrial demand on heat in Germany Heatdemandin Fredrich GEA Grasso heat pumps using ammonia ­ the megawatt range #12;GEA Refrigeration Technologies2 Achema 2012 // heat pumps using ammonia Heat pumps using ammonia ­ a sustainable choice How to improve

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

    E-Print Network [OSTI]

    Rodriguez, David

    2011-01-01

    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.

  10. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

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

    1987-01-01

    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.

  11. Magnetic refrigeration apparatus with heat pipes

    DOE Patents [OSTI]

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

    1985-10-25

    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.

  12. Commercial Refrigeration Equipment | Open Energy Information

    Open Energy Info (EERE)

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButtePower Ventures Jump to:Information9176632°,InformationRefrigeration

  13. Remarks on application of different variables for the PKN model of hydrofracturing. Various fluid-flow regimes

    E-Print Network [OSTI]

    P. Kusmierczyk; G. Mishuris; M. Wrobel

    2013-07-20

    The problem of hydraulic fracture for the PKN model is considered within the framework presented recently by Linkov (2011). The modified formulation is further enhanced by employing an improved regularized boundary condition near the crack tip. This increases solution accuracy especially for singular leak-off regimes. A new dependent variable having clear physical sense is introduced. A comprehensive analysis of numerical algorithms based on various dependent variables is provided. Comparison with know numerical results has been given.

  14. Remarks on numerical simulation of the PKN model of hydrofracturing in proper variables. Various leak-off regimes

    E-Print Network [OSTI]

    Kusmierczyk, P; Wrobel, M

    2012-01-01

    The problem of hydraulic fracture for the PKN model is considered within the framework of approach presented recently by Linkov (2011). The modified formulation is further enhanced by employing an improved regularized boundary condition near the crack tip. This increases solution accuracy especially for singular leak-off regimes. A new dependent variable having clear physical sense is introduced. A comprehensive analysis of numerical algorithms based on various dependent variables is provided.

  15. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    DOE Patents [OSTI]

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

    1995-10-31

    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.

  16. New technologies for refrigeration without CFCs

    SciTech Connect (OSTI)

    Swift, G.W.

    1992-09-01

    Today the appliance industry and other cooling industries are facing the double challenge of eliminating environmentally harmful CFCs while simultaneously improving energy efficiency. These challenges will force this industry to make tremendous changes and to work out many difficult problems, ranging from choice of technology through production-line retooling to product-liability concerns. Three new cooling technologies--sonic compression, thermoacoustic refrigeration, and Malone refrigeration--have been developed at least in part at Los Alamos National Laboratory. We will discuss the principles, features, and status of each of these three technologies. With these three examples we hope to show that mechanical compression and subsequent evaporation of CFCs is not the only potentially practical way to produce cooling. These examples are only three of many alternative cooling technologies. No new technology can be guaranteed a success before development is complete, from either an economic or engineering point of view. But enough alternative cooling technologies exist, and the probability for success of each technology is high enough, that one or more of these technologies can almost certainly be produced at reasonable cost, eliminate CFCS, and reduce the consumption of electricity.

  17. ISSUANCE 2015-10-20: Energy Conservation Program: Energy Conservation Standards for Refrigerated Beverage Vending Machines

    Broader source: Energy.gov [DOE]

    Energy Conservation Program: Energy Conservation Standards for Refrigerated Beverage Vending Machines

  18. Refrigerators and Refrigerator-Freezers (Appendix A1 after May 2, 2011) |

    Energy Savers [EERE]

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuildingBudgetFinancial Opportunities »Refrigerator Standards

  19. 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.

    1996-01-01

    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...

  20. 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

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

    DOE Patents [OSTI]

    Gaul, Christopher J.

    2003-07-01

    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.

  2. Bipolar pulse field for magnetic refrigeration

    DOE Patents [OSTI]

    Lubell, M.S.

    1994-10-25

    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.

  3. Modeling of Vertical Ground Loop Heat Exchangers with Variable Convective Resistance and Thermal Mass of the Fluid

    E-Print Network [OSTI]

    Modeling of Vertical Ground Loop Heat Exchangers with Variable Convective Resistance and Thermal-term behavior of ground loop heat exchangers (GLHE) is critical to the design and energy analysis of ground in the tube to guarantee a low convective heat transfer resistance. However, for some antifreeze types

  4. Modeling of Vertical Ground Loop Heat Exchangers with Variable Convective Resistance and Thermal Mass of the Fluid

    E-Print Network [OSTI]

    source heat pump (GSHP) systems. Thermal load profiles vary significantly from building to buildingModeling of Vertical Ground Loop Heat Exchangers with Variable Convective Resistance and Thermal-term behavior of ground loop heat exchangers (GLHE) is critical to the design and energy analysis of ground

  5. Response of the Midlatitude Jets, and of Their Variability, to Increased Greenhouse Gases in the CMIP5 Models

    E-Print Network [OSTI]

    Barnes, Elizabeth A.

    Response of the Midlatitude Jets, and of Their Variability, to Increased Greenhouse Gases This work documents how the midlatitude, eddy-driven jets respond to climate change using model output from Atlantic, the North Pacific, and the Southern Hemisphere jets. The analysis is not limited to annual- mean

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

    SciTech Connect (OSTI)

    Shrestha, Som S; Sharma, Vishaldeep; Abdelaziz, Omar

    2014-01-01

    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.

  7. Thermodynamic Evaluation of Low-Global Warming Potential Refrigerants

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

    Thermodynamic Evaluation of Low-GWP Refrigerants Mark O. McLinden National Institute of Standards and Technology markm@boulder.nist.gov; 303-497-3580 April 3, 2013 Optimization...

  8. 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

  9. Comparison of Several Eco-Friendly Refrigeration Technologies 

    E-Print Network [OSTI]

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

    2006-01-01

    will be liquefied. Heat discharged by liquefaction passes through condenser 2 and exchanges heat with refrigerant (such as air or water). When stop heating, adsorbent becomes cool, its adsorbing capacity gradually enhances again. At this moment, it adsorb...

  10. 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.

  11. 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.

  12. National Weatherization Assistance Program Evaluation: Assessment of Refrigerator Energy Use

    SciTech Connect (OSTI)

    Tonn, Bruce Edward; Goeltz, Rick

    2015-03-01

    This report assesses the energy consumption characteristics and performance of refrigerators that were monintored as a component of the Indoor Air Quality Study that itself was a component of the retrospective evaluation of the Department of Energy's Weatherization Assistance Program.

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

    E-Print Network [OSTI]

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

    2013-01-01

    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].

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

    E-Print Network [OSTI]

    Frey, H. Christopher

    . Performance, Emissions, and Cost of Combustion-Based NOx Controls for Wall and Tangential Furnace Coal ................................................................................................................... 20 3. VARIABILITY AND UNCERTAINTY IN NOX EMISSION MEASUREMENTS.................. 29 3.1 GENERAL............................................................................................................................... 1 1.2 NOX REGULATIONS

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

    E-Print Network [OSTI]

    Joshi, Praveen Sudhakar

    1999-01-01

    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...

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

    E-Print Network [OSTI]

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

    1992-01-01

    will be illustrated by two recent case studies. INTRODUCTION This paper deals with a Demand Side Management (DSM) option of using waste heat for refrigeration. Absorption Refrigeration from waste heat offers a viable option for DSM. This can profitably either... years. The potential for avoided cost through DSM will approach $45 billion over the next decade(1,2). Waste Energy And Pollutants The U.S. industry consumes more than 30 quads (quadrillion Btu) of energy each year. About one third...

  17. Quantitative Analysis of Variability and Uncertainty in Environmental Data and Models. Volume 1. Theory and Methodology Based Upon Bootstrap Simulation

    SciTech Connect (OSTI)

    Frey, H. Christopher; Rhodes, David S.

    1999-04-30

    This is Volume 1 of a two-volume set of reports describing work conducted at North Carolina State University sponsored by Grant Number DE-FG05-95ER30250 by the U.S. Department of Energy. The title of the project is “Quantitative Analysis of Variability and Uncertainty in Acid Rain Assessments.” The work conducted under sponsorship of this grant pertains primarily to two main topics: (1) development of new methods for quantitative analysis of variability and uncertainty applicable to any type of model; and (2) analysis of variability and uncertainty in the performance, emissions, and cost of electric power plant combustion-based NOx control technologies. These two main topics are reported separately in Volumes 1 and 2.

  18. Heat exchanger bypass system for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01

    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.

  19. 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.

    2006-01-01

    , the low COP of the absorption machine was limited seriously to compete with the refrigeration machine that is drove by electricity. Therefore, most researchers focus their attention on the improvement of performance of the absorption system through many...

  20. 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.

    2009-01-01

    Control Parameters C1: Compressor specifications C2: Condenser specifications C3: Capillary specifications C4: Evaporator specifications Fig. 2 – Parameter diagram of refrigeration cycle.To introduce the Bx life, the characteristic life in the Weibull... ofcharacteristic life in Eq. (4). When the number of failed samples is below four, it follows the Poisson distribution (Ryu and Chang, 2005). At a sixty-percent confidence level, the characteristic life is defined as on refrigeration cycle.cycles and the number...

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

    DOE Patents [OSTI]

    Ecker, Amir L. (Dallas, TX)

    1982-01-01

    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.

  2. A Method for On-Going Commissioning of VRV Package Systems Using a Simulation Model 

    E-Print Network [OSTI]

    Yamaha, M.; Sekiyama, K.; Misaki, S.

    2006-01-01

    is not known. A simulation model based on a refrigeration cycle was proposed to evaluate system performance. Basic conditions for evaporation and condensation were defined from conditions provided in Japanese Industrial Standards (JIS). Flow rate of refrigerant...

  3. 11-14 An ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid is considered. The rate of heat removal from the refrigerated space, the power input to the compressor, the rate of heat rejection to the environment,

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    -compression refrigeration cycle, the refrigerant enters the compressor as a saturated vapor at the evaporator pressure11-7 11-14 An ideal vapor-compression refrigeration cycle with refrigerant-134a as the working fluid is considered. The rate of heat removal from the refrigerated space, the power input

  4. 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

    2015-01-01

    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...

  5. 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)

    1999-01-01

    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.

  6. 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

    2015-01-01

    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 ...

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

    E-Print Network [OSTI]

    Miller, Franklin K., 1970-

    2005-01-01

    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 ...

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

    SciTech Connect (OSTI)

    NONE

    1996-01-01

    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. Counter-Top Thermoacoustic Refrigerator- An Experimental Investigation

    SciTech Connect (OSTI)

    Anwar, Mahmood; Ghazali, Normah Mohd

    2010-06-28

    Thermoacoustic phenomenon is a new alternative refrigeration technology. Though design and fabrication is complex for getting the desired effect, it is environmentally friendly and successful system showed that it is relatively easy to run compared to the traditional vapor compression refrigeration system. Currently, theories supporting the thermoacoustic refrigeration systems are yet to be comprehensive to make them commercially viable. Theoretical, experimental, and numerical studies are being done to address the thermodynamics-acoustics interactions. In this study, experimental investigations were completed to test the feasibility of the practical use of a thermoacoustic refrigerator in its counter-top form for future specific application. The system was designed and fabricated based on linear acoustic theory. Acoustic power was given by a loud speaker and thermoacoustic effects were measured in terms of the cooling effects produced at resonanance. Investigations showed that discrepancies between designed and working resonance frequency exist. Thermoacoutic cooling improved at a certain frequency, achieved when the working frequency was varied away from the design frequency. A cooling effect of 4.8 K below the ambient temperature of 23.3 deg. C was obtained from the counter-top thermoacoustic system. This system uses no refrigerants and no compressor to generate the cooling effect, a potential to be further investigated for a practical system.

  10. 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

  11. Solutions for Summer Electric Power Shortages: Demand Response and its Applications in Air Conditioning and Refrigerating Systems

    E-Print Network [OSTI]

    Han, Junqiao; Piette, Mary Ann

    2008-01-01

    LBNL-63806 Refrigeration, Air Conditioning, & Electric Powerand its Applications in Air Conditioning and Refrigeratingand its applications in Air Conditioning and refrigerating

  12. A baseline model for utility bill analysis using both weather and non-weather-related variables

    SciTech Connect (OSTI)

    Sonderegger, R.C. [SRC Systems, Inc., Berkeley, CA (United States)

    1998-12-31

    Many utility bill analyses in the literature rely only on weather-based correlations. While often the dominant cause of seasonal variations in utility consumption, weather variables are far from the only determinant factors. Vacation shutdowns, plug creep, changes in building operation and square footage, and plain poor correlation are all too familiar to the practicing performance contractor. This paper presents a generalized baseline equation, consistent with prior results by others but extended to include other, non-weather-related independent variables. Its compatibility with extensive prior research by others is shown, as well as its application to several types of facilities. The baseline equation, as presented, can accommodate up to five simultaneous independent variables for a maximum of eight free parameters. The use of two additional, empirical degree-day threshold parameters is also discussed. The baseline equation presented here is at the base of a commercial utility accounting software program. All case studies presented to illustrate the development of the baseline equation for each facility are drawn from real-life studies performed by users of this program.

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

    E-Print Network [OSTI]

    P. T. Zycki; A. Rozanska

    2001-02-13

    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.

  14. A cryogen-free dilution refrigerator based Josephson qubit measurement system

    E-Print Network [OSTI]

    Tian, Ye; Yu, H. F.; Deng, H.; Xue, G. M.; Liu, D. T.; Ren, Y. F.; Chen, G.; Zheng, D. N.; Jing, X. N.; Lu, Li; Zhao, S. P.; Han, Siyuan

    2012-01-12

    We develop a small-signal measurement system on cryogen-free dilution refrigerator which is suitable for superconductingqubit studies. Cryogen-free refrigerators have several advantages such as less manpower for system operation and large sample...

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

    E-Print Network [OSTI]

    Owner

    2011-04-28

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

  16. Compatibility of refrigerants and lubricants with electrical sheet insulation under retrofit conditions

    SciTech Connect (OSTI)

    Doerr, R.G.; Waite, T.D.

    1996-11-01

    To determine whether exposure to the original refrigerant/mineral oil would affect compatibility of sheet insulation with alternative refrigerant/lubricant after retrofit, sheet insulation was exposed at elevated temperature to the original refrigerant and mineral oil for 500 hours, followed by exposure to the alternative refrigerant and lubricant for 500 hours. Most of the sheet insulation materials exposed to the alternative refrigerant and lubricant (after an initial exposure to the original refrigerant and mineral oil) appeared to be compatible with the alternative refrigerant and lubricant. The only concern was delamination and blistering of the sheet insulation containing Nomex, especially after removal of absorbed refrigerant at high temperature. This was attributed to incompatibility of the adhesive and not to the Nomex itself. Embrittlement of the polyethylene terephthalate (PET) sheet was initially observed, but 2048 subsequent tests under extremely dry conditions showed that embrittlement of the PET materials was attributed to moisture present during the exposure.

  17. 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

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

    E-Print Network [OSTI]

    Peffer, Therese; Burke, William; Auslander, David

    2010-01-01

    the Design of Residential Demand Responsive Technology withHiroshi Asano. 2006. A Residential End-Use Demand Model forModelling of Energy Demand in the Residential Sector: 1.

  19. Modeling Variability and Uncertainty of Photovoltaic Generation: A Hidden State Spatial Statistical Approach

    E-Print Network [OSTI]

    Tabone, Michaelangelo D; Callaway, Duncan S

    2015-01-01

    require- ments in unit commitment optimal dispatch modelsLaboratory (NREL) uses a unit commitment optimal dispatch

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

    E-Print Network [OSTI]

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

    2006-01-01

    HVAC Technologies for Energy Efficiency Vol.IV-1-5 Associate Master Professor Application Availability of Insulation Heat of the Terrace in a Rebuilt Refrigerator Chunmin Qu Yong Sun Zhonghai Chen Master... refrigerator; insulation heat; saving energy 1. INTRODUCTION The homoiothermal refrigerators that are built early day need be rebuilt to the cryogenic refrigerators along with the development continuously of market economy. The matching...

  1. Demand Response Opportunities in Industrial Refrigerated Warehouses in California

    SciTech Connect (OSTI)

    Goli, Sasank; McKane, Aimee; Olsen, Daniel

    2011-06-14

    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.

  2. 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.

    1986-04-03

    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.

  3. The growth rate of gas hydrate from refrigerant R12

    SciTech Connect (OSTI)

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

    2006-07-15

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

  4. 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)

    1987-01-01

    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.

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

    SciTech Connect (OSTI)

    Not Available

    1994-09-01

    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.

  6. Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander

    E-Print Network [OSTI]

    Bahrami, Majid

    Exergy analysis of transcritical carbon dioxide refrigeration cycle with an expander Jun Lan Yang is performed for the transcritical carbon dioxide refrigeration cycles with a throttling valve attracted considerable attention. As one of the natural refrigerants, carbon dioxide has many excellent

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

    E-Print Network [OSTI]

    Dhamala, Mukesh

    the cooling towers around a large power plant. The power plant is generating electricity by turning heat and refrigerators. #12;Topics: · Turning Heat into Work · Heat Engines and Refrigerators · Ideal-Gas Heat Engines Addison-Wesley. · Ideal-Gas Refrigerators · The Limits of Efficiency · The Carnot Cycle #12;Chapter 19

  8. Cataclysmic Variables

    E-Print Network [OSTI]

    Robert Connon Smith

    2007-01-23

    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.

  9. Large-scale Environmental Variables and Transition to Deep Convection in Cloud Resolving Model Simulations: A Vector Representation

    SciTech Connect (OSTI)

    Hagos, Samson M.; Leung, Lai-Yung R.

    2012-11-01

    Cloud resolving model simulations and vector analysis are used to develop a quantitative method of assessing regional variations in the relationships between various large-scale environmental variables and the transition to deep convection. Results of the CRM simulations from three tropical regions are used to cluster environmental conditions under which transition to deep convection does and does not take place. Projections of the large-scale environmental variables on the difference between these two clusters are used to quantify the roles of these variables in the transition to deep convection. While the transition to deep convection is most sensitive to moisture and vertical velocity perturbations, the details of the profiles of the anomalies vary from region to region. In comparison, the transition to deep convection is found to be much less sensitive to temperature anomalies over all three regions. The vector formulation presented in this study represents a simple general framework for quantifying various aspects of how the transition to deep convection is sensitive to environmental conditions.

  10. The effect of variable thermal diffusivity on kinematic models of subduction

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    at the surface and thermal insulating effects once subducted. Temperature differences between models based on the interpretation of seismic tomog- raphy suggest that subducting slabs penetrate the whole

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

    E-Print Network [OSTI]

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

    2013-01-01

    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

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

    E-Print Network [OSTI]

    Peffer, Therese; Burke, William; Auslander, David

    2010-01-01

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

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

    E-Print Network [OSTI]

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

    2013-01-01

    Model (WVM) for Solar PV Power Plants Matthew Lave, Jansimulating solar photovoltaic (PV) power plant output giventhe power output of a solar photovoltaic (PV) plant was

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

    E-Print Network [OSTI]

    Peffer, Therese; Burke, William; Auslander, David

    2010-01-01

    variation imposed by occupant behavior and appliance loads.a stochastic model of occupant behavior to develop annualhousehold occupant make-up and behavior. Physical factors,

  15. 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.

  16. Modeling circulation and thermal structure in Lake Michigan: Annual cycle and interannual variability

    E-Print Network [OSTI]

    structure in Lake Michigan: spring thermal bar, full stratification, deepening of the thermocline duringModeling circulation and thermal structure in Lake Michigan: Annual cycle and interannual and thermal structure in the lake. The model was able to reproduce all of the basic features of the thermal

  17. Optimal threshold policies in a workload model with a variable number of service phases per job

    E-Print Network [OSTI]

    Brouns, Gido

    and termination control, optimal threshold policies, Markov decision processes. 1 Introduction Workload models of performance optimization is the question of how to control some type of system in an optimal way within in literature so far. Stidham and Weber 4 present a comprehensive overview of models for the optimal control

  18. Supervised Learning Based Model for Predicting Variability-Induced Timing Errors

    E-Print Network [OSTI]

    Gupta, Rajesh

    combat variations in hardware and workload by increasing conservative guardbanding that leads, for a given amount of guardband reduction. The proposed methodology enables a model-based rule method the robustness of our modeling methodology by considering various operating voltage and temperature corners. Our

  19. Re-conceptualizing the soil and water assessment tool (SWAT) model to predict runoff from variable

    E-Print Network [OSTI]

    Walter, M.Todd

    runoff in ways that implicitly assume an infiltration-excess response to rainfall. Because of this generated in rural, humid regions. In this study, the Soil and Water Assessment Tool (SWAT) model was re is applied in these models implicitly assumes an infiltration-excess (or Hortonian, i.e., Horton, 1933

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

    SciTech Connect (OSTI)

    Robert Pincus

    2011-05-17

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

  1. Purchasing Energy-Efficient 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.

  2. page 1 of 4 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    devices. 201. An office is heated using a heat pump system based on a vapour-compression cycle is the compressor work w (kJ/kg refrigerant) (2 p.) c. What is the coefficient of performance COP of this heat pump? Compare it with the COP of a Carnot process heat pump operating between -20°C and 30°C. (2 p.) d

  3. Reliability of Heat Pumps Containing R410-A Refrigerant 

    E-Print Network [OSTI]

    McJimsey, B. A.; Cawley, D.

    1998-01-01

    of their potential destruction of ozone in the troposphere. Residential and commercial rooftop units usually contain hydrochlorofluorocarbon 22 , (also referred to as HCFC-22 or R-22). R-22 has been used successfully as a refrigerant in HVAC equipment for over 40...

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

    SciTech Connect (OSTI)

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

    2014-08-01

    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.

  5. Feasibility of Solar-Assisted Refrigerated Transport in Australia

    E-Print Network [OSTI]

    unit. This has proven to be reasonably economical, given the high cost of diesel fuel in the UK the fea- sibility of using photovoltaics to minimise the use of diesel generators in refrigerated because it competes with the price of electricity generated off-grid. The UK experience is compelling

  6. Layer of protection analysis applied to ammonia refrigeration systems 

    E-Print Network [OSTI]

    Zuniga, Gerald Alexander

    2009-05-15

    the risks in existing and future ammonia refrigeration systems to ensure their safety. LOPA (Layer of Protection Analysis) is one of the best ways to estimate the risk. It provides quantified risk results with less effort and time than other methods. LOPA...

  7. Triple loop heat exchanger for an absorption refrigeration system

    DOE Patents [OSTI]

    Reimann, Robert C. (Lafayette, NY)

    1984-01-01

    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.

  8. Effects of Refrigeration and Freezing on the Electromechanical and

    E-Print Network [OSTI]

    Buschmann, Michael

    Effects of Refrigeration and Freezing on the Electromechanical and Biomechanical Properties.buschmann@polymtl.ca In vitro electromechanical and biomechanical testing of articular cartilage provide critical information,6 . Biomechanical and electromechanical tests are used to assess cartilage functional properties and reflect its

  9. 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 School of Communications and Informatics Victoria University PO Box 14428, Melbourne City MC VIC 8001 2-5, 2001 Abstract. The paper describes the development of a smart embedded fuzzy system for reefer

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

    E-Print Network [OSTI]

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

    1980-01-01

    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...

  11. 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 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity

  12. 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

  13. Water Vapor Variability Across Spatial Scales: Insights for Theory, Parameterization, and Model Assessment

    E-Print Network [OSTI]

    Pressel, Kyle Gregory

    2012-01-01

    11 2 Scaling of Water Vapor Structure Functions as 2.1cloud model. q is the total water mixing-ratio and q ? isAIRS Exponents from AIRS Data Water Vapor Time Series from a

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

    E-Print Network [OSTI]

    Till, Christy B.

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

  15. INVERSE BIOMEDICAL IMAGING USING SEPARATELY ADAPTED MESHES FOR PARAMETERS AND FORWARD MODEL VARIABLES1

    E-Print Network [OSTI]

    Bangerth, Wolfgang

    INVERSE BIOMEDICAL IMAGING USING SEPARATELY ADAPTED MESHES FOR PARAMETERS AND FORWARD MODEL Many important existing and upcoming biomedical imaging modalities lead to nonlinear relationships experiment. 1. INTRODUCTION In a number of current and upcoming biomedical imaging methods, the relationship

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

    E-Print Network [OSTI]

    David Gelbwaser-Klimovsky; Gershon Kurizki

    2015-01-31

    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.

  17. Time-variability of alpha from realistic models of Oklo reactors

    E-Print Network [OSTI]

    C. R. Gould; E. I. Sharapov; S. K. Lamoreaux

    2007-04-30

    We reanalyze Oklo $^{149}$Sm data using realistic models of the natural nuclear reactors. Disagreements among recent Oklo determinations of the time evolution of $\\alpha$, the electromagnetic fine structure constant, are shown to be due to different reactor models, which led to different neutron spectra used in the calculations. We use known Oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models. Two Oklo reactors, RZ2 and RZ10, were modeled with MCNP. The resulting neutron spectra were used to calculate the change in the $^{149}$Sm effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-meV resonance. We independently deduce ancient $^{149}$Sm effective cross sections, and use these values to set limits on the time-variation of $\\alpha$. Our study resolves a contradictory situation with previous Oklo $\\alpha$-results. Our suggested $2 \\sigma$ bound on a possible time variation of $\\alpha$ over two billion years is stringent: $ -0.24 \\times 10^{-7} \\le \\frac{\\Delta \\alpha}{\\alpha} \\le 0.11 \\times 10^{-7}$, but model dependent in that it assumes only $\\alpha$ has varied over time.

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

    SciTech Connect (OSTI)

    Lowe, K.T.

    2005-10-07

    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.

  19. 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

    of these magnets (I will call them type A), the magnetic force problem we need to solve involves only the magnet and the steel skin of the refrigerator door. The second kind of magnet (I will call it type B) has an additional includes all three components. For both types of configurations we will assume that the magnetization

  20. 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

    of a piston, an aftercooler (AC), a regenerator, a cold heat exchanger (CHX), a tube, a hot heat exchanger ( numerical model has been introduced to study steady oscillatory heat and mass transfer in the tube section, numerical simulation, high resolution scheme 1 Introduction The pulse tube is a relatively new type

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

    E-Print Network [OSTI]

    T. Thiemann

    1999-10-04

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

  2. Local observability of state variables and parameters in nonlinear modeling quantified by delay reconstruction

    E-Print Network [OSTI]

    Parlitz, Ulrich; Luther, Stefan

    2015-01-01

    Features of the Jacobian matrix of the delay coordinates map are exploited for quantifying the robustness and reliability of state and parameter estimations for a given dynamical model using an observed time series. Relevant concepts of this approach are introduced and illustrated for discrete and continuous time systems employing a filtered H\\'enon map and a R\\"ossler system.

  3. Spatial variability of regional model simulated JuneSeptember mean precipitation over West Africa

    E-Print Network [OSTI]

    made with the CCSR/GISS RM3, driven by synchronous data from NCEP reanalysis. A five-member ensemble for a single season was generated by staggering the initial conditions of each member by 36 hr within] Regional climate model (RCM) simulations are driven by synchronous lateral boundary conditions (LBC

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

    E-Print Network [OSTI]

    Fang, Yue

    2006-08-16

    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. The results show that the RP...

  5. Statistical models in prognostic modelling with many skewed variables and missing data: a case study in breast cancer 

    E-Print Network [OSTI]

    Baneshi, Mohammad Reza

    2009-01-01

    Prognostic models have clinical appeal to aid therapeutic decision making. In the UK, the Nottingham Prognostic Index (NPI) has been used, for over two decades, to inform patient management. However, it has been commented ...

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

    E-Print Network [OSTI]

    Rodriguez, E.; Rasmussen, B.

    2015-01-01

    at Texas A&M University, College Station, TX 77843-3123, USA 2Associate Professor in the Department of Mechanical Engineering at Texas A&M University, College Station, TX 77843- 3123, USA June 1, 2015 DRAFT ESL-TR-15-06-01 2TABLE I: Operating Conditions... Simulation time (s) 400 Simulation step size (s) 0.01 Solver Fourth Order Runge-Kutta June 1, 2015 DRAFT ESL-TR-15-06-01 3A. Length Threshold Analysis Fig. 1: Comparison of minimum normalized threshold length, leps, for enthalpy based SMB model - Case 1a June...

  7. The influence of selection effects on the observed cataclysmic variable population: modelling and application to the Palomar-Green sample

    E-Print Network [OSTI]

    Magaretha L. Pretorius; Christian Knigge; Ulrich Kolb

    2006-11-06

    Large differences between the properties of the known sample of cataclysmic variable stars (CVs) and the predictions of the theory of binary star evolution have long been recognised. However, because all existing CV samples suffer from strong selection effects, observational biases must be taken into account before it is possible to tell whether there is an inconsistency. In order to address this problem, we have modelled the impact of selection effects on observed CV samples using a Monte Carlo approach. By simulating the selection criteria of the Palomar-Green (PG) Survey, we show that selection effects cannot reconcile the predictions of standard CV evolution theory with the observed sample. More generally, we illustrate the effect of the biases that are introduced by magnitude limits, selection cuts in U-B, and restrictions in galactic latitude.

  8. Miniaturized Air-to-Refrigerant Heat Exchangers

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

    Design and fabricate 10kW Radiators (in progress) Test radiators and update models as required * Conduct noisevibrations analysis Design and fabricate...

  9. Compatibility of refrigerants and lubricants with motor materials under retrofit conditions

    SciTech Connect (OSTI)

    Doerr, R.; Waite, T.

    1995-01-12

    Motor materials were exposed to original refrigerants R-11, R-12, R-22 and R-502 in the presence of mineral oil for 500 hours. These same materials were then exposed to alternative refrigerants R-123, R-134a, R-407C (R-32/R-125/R-134a) and R-404A (R-125/R-143a/R-134a), respectively, in the presence of the appropriate lubricant for 500 hours. As a control, some samples were exposed to the original refrigerant/mineral oil for a total of 1,000 hours. These tests were conducted to determine whether exposure to the original refrigerant/mineral oil would affect compatibility of the motor materials with the alternative refrigerant/lubricant after retrofit. Motor materials exposed to the alternative refrigerant and lubricant (after an initial exposure to the original refrigerant and mineral oil) appeared to be compatible with the alternative refrigerant and lubricant. The only concerns were embrittlement of the polyethylene terephthalate (PET) sheet and sleeving insulations, and delamination and blistering of the Nomex sheet insulation in the R-22, R-502, and R-12. Embrittlement of the PET materials was attributed to moisture present during the exposure. Separation of the 475 varnish from metal surfaces in the R-123 was also a concern. The sheet and sleeving insulations were affected by the original refrigerant/mineral oil to a greater extent than by the alternative refrigerant and lubricant.

  10. Computational experiences with variable modulus, elastic-plastic, and viscoelastic concrete models. [HTGR

    SciTech Connect (OSTI)

    Anderson, C.A.

    1981-01-01

    Six years ago the Reactor Safety Research Division of the Nuclear Regulatory Commission (NRC) approached the Los Alamos National Laboratory to develop a comprehensive concrete structural analysis code to predict the static and dynamic behavior of Prestressed Concrete Reactor Vessels (PCRVs) that serve as the containment structure of a High-Temperature Gas-Cooled Reactor. The PCRV is a complex concrete structure that must be modeled in three dimensions and posseses other complicating features such as a steel liner for the reactor cavity and woven cables embedded vertically in the PCRV and wound circumferentially on the outside of the PCRV. The cables, or tendons, are used for prestressing the reactor vessel. In addition to developing the computational capability to predict inelastic three dimensional concrete structural behavior, the code response was verified against documented experiments on concrete structural behavior. This code development/verification effort is described.

  11. Pilot Testing of Commercial Refrigeration-Based Demand Response

    SciTech Connect (OSTI)

    Hirsch, Adam; Clark, Jordan; Deru, Michael; Trenbath, Kim; Doebber, Ian; Studer, Daniel

    2015-10-08

    Supermarkets potentially offer a substantial demand response (DR) resource because of their high energy intensity and use patterns. This report describes a pilot project conducted to better estimate supermarket DR potential. Previous work has analyzed supermarket DR using heating, ventilating, and air conditioning (HVAC), lighting, and anti-condensate heaters. This project was concerned with evaluating DR using the refrigeration system and quantifying the DR potential inherent in supermarket refrigeration systems. Ancillary aims of the project were to identify practical barriers to the implementation of DR programs in supermarkets and to determine which high-level control strategies were most appropriate for achieving certain DR objectives. The scope of this project does not include detailed control strategy development for DR or development of a strategy for regional implementation of DR in supermarkets.

  12. Circulating heat exchangers for oscillating wave engines and refrigerators

    DOE Patents [OSTI]

    Swift, Gregory W.; Backhaus, Scott N.

    2003-10-28

    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.

  13. Free displacer and Ringbom displacer for a Malone refrigerator

    SciTech Connect (OSTI)

    Swift, G.W.; Brown, A.O.

    1994-05-01

    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.

  14. Heat powered refrigeration compressor. Semi-annual technical report

    SciTech Connect (OSTI)

    Goad, R.R.

    1981-01-01

    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.

  15. Solar heat pump systems with refrigerant-filled collectors

    SciTech Connect (OSTI)

    O'Dell, M.P.; Beckman, W.A.; Mitchell, J.W.

    1983-01-01

    The heat pump system with a refrigerant-filled evaporator consists of a standard air-to-air or air-to-liquid heat pump that utilizes a solar panel as the evaporator. A combination of solar energy and convection heat transfer acts as the ''free'' energy absorbed by the collector/evaporator. In this paper, the seasonal performance of such systems for industrial applications will be presented. Performance of collector/evaporator heat pumps will be compared with alternative heat pump and solar systems. The benefits of covered and coverless collector/evaporators will be discussed. Results to date have shown that refrigerant-filled collector heat pumps do not perform as well as conventional heat pumps at small collector areas but have as much as 15% performance improvement over conventional heat pumps at an appropriate collector area.

  16. Cryogenics for superconductors: Refrigeration, delivery, and preservation of the cold

    SciTech Connect (OSTI)

    Venkatarao Ganni, James Fesmire

    2012-06-01

    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.

  17. New age water chillers with water as refrigerant

    E-Print Network [OSTI]

    Kühnl-Kinel, J

    1998-01-01

    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.

  18. Experiments and modeling of variably permeable carbonate reservoir samples in contact with CO?-acidified brines

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Smith, Megan M.; Hao, Yue; Mason, Harris E.; Carroll, Susan A.

    2014-12-31

    Reactive experiments were performed to expose sample cores from the Arbuckle carbonate reservoir to CO?-acidified brine under reservoir temperature and pressure conditions. The samples consisted of dolomite with varying quantities of calcite and silica/chert. The timescales of monitored pressure decline across each sample in response to CO? exposure, as well as the amount of and nature of dissolution features, varied widely among these three experiments. For all samples cores, the experimentally measured initial permeability was at least one order of magnitude or more lower than the values estimated from downhole methods. Nondestructive X-ray computed tomography (XRCT) imaging revealed dissolution featuresmore »including “wormholes,” removal of fracture-filling crystals, and widening of pre-existing pore spaces. In the injection zone sample, multiple fractures may have contributed to the high initial permeability of this core and restricted the distribution of CO?-induced mineral dissolution. In contrast, the pre-existing porosity of the baffle zone sample was much lower and less connected, leading to a lower initial permeability and contributing to the development of a single dissolution channel. While calcite may make up only a small percentage of the overall sample composition, its location and the effects of its dissolution have an outsized effect on permeability responses to CO? exposure. The XRCT data presented here are informative for building the model domain for numerical simulations of these experiments but require calibration by higher resolution means to confidently evaluate different porosity-permeability relationships.« less

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

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and liquified by the cold low pressure He3 gas in a counterflow heat exchanger. That allows to operate refrigerator. The tubular heat exchanger is constructed as follows. A Cu-Ni tube 0.6/0.4 mm (o.d., i.d.), 1.5 m into a coil of about 32 mm in diameter. The mixing chamber has a sintered copper heat exchanger with a surface

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

    E-Print Network [OSTI]

    Wilcox, M. H.

    1995-01-01

    -pressure regulators (BPRs) or liquid solenoids, and condensers cycle fans. Unfortunately, these control methods do not provide the maximum attainable reduction in brake horsepower (BHP) as refrigeration capacity is reduced. This paper will discuss... theory and case study, speed control of these components provides maximum flexibility, control and energy efficiency. SPEED CONTROL BACKGROUND In standard system design, electric motors are intended to operate at a fixed speed. This speed...

  1. Applications Tests of Energy Efficient, Environmentally Friendly Refrigerants 

    E-Print Network [OSTI]

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

    1999-01-01

    the Twenty-first National Industrial Energy Technology Conference, Houston, TX, May 12-13, 1999 ~ ::l ;; il fitO(x) ~- f-T (; av~ 30 -----.------r---..,----r-----,-----r----,---r--i 30 E+++ 0 ~ ~ cr:" -10 -20 -20 L... ambient temperatures, and a moderately high global warming potential (GWP). 197 ESL-IE-99-05-29 Proceedings from the Twenty-first National Industrial Energy Technology Conference, Houston, TX, May 12-13, 1999 The Ikon? Refrigerants The original goal...

  2. page 1 of 5 TkF Vrmeteknik Refrigeration / Kylteknik

    E-Print Network [OSTI]

    Zevenhoven, Ron

    of the cycle (MPa). (1p.) b. Determine the mass flow rate of the working fluid (kg/s) and compressor power (kW) in kW. (2p.) Use tabelised data for R-134a, otherwise the log p, h diagram given below (next page). #12 within 1 hour, calculate the minimum cooling/freezing capacity of the refrigerator (W) and the time

  3. Fuel Cell Based Auxiliary Power Unit for Refrigerated Trucks

    SciTech Connect (OSTI)

    Brooks, Kriston P.

    2014-09-02

    This is the annual report for the Market Transformation project as required by DOE EERE's Fuel Cell Technologies Office. We have been provided with a specific format. It describes the work that was done in developing fuel-cell powered Transport Refrigeration Units for Reefer Trucks. It describes the progress that has been made by Nuvera and Plug Power as they develop and ultimately demonstrate this technology in real world application.

  4. DOE Opens Three Investigations into Alleged Refrigerator Efficiency

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

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based| Department ofRefrigeratorsDepartment of Energy Investigation

  5. Refrigerator Standards Save Consumers $ Billions | Department of Energy

    Energy Savers [EERE]

    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: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematicsEnergyInterested PartiesBuildingBudgetFinancial Opportunities »Refrigerator Standards Save

  6. New waste-heat refrigeration unit cuts flaring, reduces pollution

    SciTech Connect (OSTI)

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

    1998-05-18

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

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

    SciTech Connect (OSTI)

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

    1987-05-01

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

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

    DOE Patents [OSTI]

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

    1999-03-30

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

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

    SciTech Connect (OSTI)

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

    2014-05-28

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

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

    DOE Patents [OSTI]

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

    1997-01-01

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

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

    DOE Patents [OSTI]

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

    1997-04-22

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

  12. X-ray variability and correlations in the two phase disk-corona model for Seyfert galaxies

    E-Print Network [OSTI]

    Francesco Haardt; Laura Maraschi; Gabriele Ghisellini

    1996-09-06

    We discuss in detail the broad band X-ray variability expected in Seyfert galaxies in the framework of a Compton cooled corona model. Variations in the optical depth tau of the corona cause spectral changes in the Comptonized emission in the sense that the spectrum steepens and the temperature decreases with increasing tau. If the corona is pair dominated, tau is determined by the compactness (proportional to luminosity for fixed size). This yields a definite relation between spectral shape and intensity implying a variation in intensity of a factor 10 for a change of 0.2 in the 2-10 keV spectral index. For low pair density coronae, no definite prediction is possible. In the absence of substantial changes in the structure of the corona, the soft thermal component correlates with the medium-hard Comptonized component. Examples are computed using the ROSAT response matrix, showing that current observations of NGC 5548 and Mrk 766 showing different behaviours can be reconciled with the model. The spectral behaviour of Mrk 766 strongly suggests that the coronal plasma in this source is not pair dominated.

  13. The superfluid Stirling refrigerator, a new method for cooling below 0.5 K

    SciTech Connect (OSTI)

    Brisson, J.G.; Kotsubo, V.; Swift, G.W.

    1993-04-09

    A new subkelvin refrigerator, the superfluid Stirling cycle refrigerator, uses a working fluid of {sup 3}He-{sup 4}He mixture in a Stirling cycle. The thermodynamically active components of the mixture are the {sup 3}He, which behaves like a Boltzman gas, and the phonon-roton gas in the {sup 4}He. The superfluid component of the liquid is inert. Two refrigerators have been built and temperatures of 340 mK have been achieved.

  14. The superfluid Stirling refrigerator, a new method for cooling below 0. 5 K

    SciTech Connect (OSTI)

    Brisson, J.G.; Kotsubo, V.; Swift, G.W.

    1993-04-09

    A new subkelvin refrigerator, the superfluid Stirling cycle refrigerator, uses a working fluid of [sup 3]He-[sup 4]He mixture in a Stirling cycle. The thermodynamically active components of the mixture are the [sup 3]He, which behaves like a Boltzman gas, and the phonon-roton gas in the [sup 4]He. The superfluid component of the liquid is inert. Two refrigerators have been built and temperatures of 340 mK have been achieved.

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

    SciTech Connect (OSTI)

    Gunsel, Selda; Pozebanchuk, Michael

    1999-04-01

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

  16. Numerical Simulation of Pulse-Tube Refrigerators

    E-Print Network [OSTI]

    Tijsseling, A.S.

    . . . . . . . . . . . . . . . . . . 51 3.3.1 A model problem . . . . . . . . . . . . . . . . . 52 3.3.2 Two-grid LUGR with fixed refinement area . . . . . . . . 53 3.3.3 Two-grid LUGR with moving refinement area . . . . . . . 55 4 in fully developed pipe flow . . . . 76 5 Flow and heat transfer computations for the pulse tube 81 5.1 One

  17. Top-down estimate of anthropogenic emission inventories and their interannual variability in Houston using a mesoscale inverse modeling technique

    SciTech Connect (OSTI)

    Brioude, J.; Kim, S. W.; Angevine, Wayne M.; Frost, G. J.; Lee, S. H.; McKeen, S. A.; Trainer, Michael; Fehsenfeld, Fred C.; Holloway, J. S.; Ryerson, T. B.; Williams, E. J.; Petron, Gabrielle; Fast, Jerome D.

    2011-10-31

    The 2000 and 2006 Texas Air Quality Study (TexAQS 2000 and 2006) field campaigns took place in eastern Texas in August-October of 2000 and 2006. Several flights of the National Oceanic and Atmospheric Administration (NOAA) and National Center for Atmospheric Research (NCAR) research aircraft were dedicated to characterizing anthropogenic emissions over Houston. Houston is known for having serious problems with non-attainment of air quality standards. We present a method that uses three models and aircraft observations to assess and improve existing emission inventories using an inverse modeling technique. We used 3-dimensional and 4-dimensional variational (3D-VAR and 4D-VAR) inverse modeling techniques based on a least-squares method to improve the spatial and temporal distribution of CO, NOy (sum of all reactive nitrogen compounds), and SO2 emissions predicted by the 4-km-resolution U.S. Environmental Protection Agency (EPA) National Emission Inventory (NEI) for 2005. Differences between the prior and posterior inventories are discussed in detail. We found that in 2006 the prior daytime emissions in the urban area of Houston have to be reduced by 40% {+-} 12% for CO and 7% {+-} 13% for NOy. Over the Houston Ship Channel, where industrial emissions are predominant, the prior emissions have to be reduced by 41% {+-} 15% for CO and 51% {+-} 9% for NOy. Major ports around Houston have their NOy emissions reduced as well, probably due to uncertainties in near-shore ship emissions in the EPA NEI inventory. Using the measurements from the two field campaigns, we assessed the interannual emission variability between 2000 and 2006. Daytime CO emissions from the Houston urban area have been reduced by 8% {+-} 20%, while the NOy emissions have increased by 20% {+-} 12% from 2000 to 2006. In the Houston Ship Channel, the daytime NOy emissions have increased by 13% {+-} 17%. Our results show qualitative consistencies with known changes in Houston emissions sources.

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

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

    of low-global warming potential (GWP) refrigerants. DOE commissioned this roadmap to establish a set of high-priority research and development (R&D) activities that...

  19. Research and Development Roadmap For Next-Generation Low-Global Warming Potential Refrigerants

    SciTech Connect (OSTI)

    none,

    2011-07-01

    The Department of Energy commissioned this roadmap to establish a set of high-priority research and development (R&D) activities that will accelerate the transition to low-GWP refrigerants across the entire heating, ventilation, air-conditioning and refrigeration (HVAC&R) industry. The schedule of R&D activities occurs within an accelerated five-year timeframe, and covers several prominent equipment types. The roadmap is organized around four primary objectives to: assess and mitigate safety risks, characterize refrigerant properties, understand efficiency and environmental tradeoffs, and support new refrigerant and equipment development.

  20. A Cooperative Demand Response Scheme Using Punishment Mechanism and Application to Industrial Refrigerated Warehouses

    E-Print Network [OSTI]

    Ma, Kai; Hu, Guoqiang; Spanos, Costas J

    2014-01-01

    Z. Yang, and Y. Zhang, “Demand response man- agement withwith application to demand response,” IEEE Transactions onand automated demand response in industrial refrigerated

  1. New Regenerative Cycle for Vapor Compression Refrigeration

    SciTech Connect (OSTI)

    Bergander, Mark J [Magnetic Development, Inc.; Butrymowicz, Dariusz [Polish Academy of Scinces

    2010-01-26

    This project was a continuation of Category 1 project, completed in August 2005. Following the successful bench model demonstration of the technical feasibility and economic viability, the main objective in this stage was to fabricate the prototype of the heat pump, working on the new thermodynamic cycle. This required further research to increase the system efficiency to the level consistent with theoretical analysis of the cycle. Another group of objectives was to provide the foundation for commercialization and included documentation of the manufacturing process, preparing the business plan, organizing sales network and raising the private capital necessary to acquire production facilities.

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

    DOE Patents [OSTI]

    Gaul, Christopher J. (Thornton, CO)

    2001-01-01

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

  3. ASHRAE $1000 Scholarship Application (02/26/2013) The Utah Chapter of the American Society of Heating, Refrigerating and Air Conditioning

    E-Print Network [OSTI]

    van den Berg, Jur

    of Heating, Refrigerating and Air Conditioning Engineers is offering multiple $1,000 scholarships automation or controls, heating, ventilating, refrigeration or air conditioning (HVAC) principles are invited

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

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

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    type air-source VRF system and a GSHP system that uses single-stage scroll compressors and vertical ground loop heat exchanger (

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    GSHP system is more energy efficient than the air-source VRFGSHP system is more energy efficient than the air-source VRVintended to be as energy efficient as required by current

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

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

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

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

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    dual compressor available on the market Compared with the selected building, a more energy efficient building will have lower space cooling and heating

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

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

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

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

    DOE Patents [OSTI]

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

    1990-01-01

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

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

    DOE Patents [OSTI]

    Chen, G.; Beale, W.T.

    1990-04-03

    The power output of a free piston Stirling engine is matched to a gas compressor which it drives and its stroke amplitude is made relatively constant as a function of power by connecting a gas spring to the drive linkage from the engine to the compressor. The gas spring is connected to the compressor through a passageway in which a valve is interposed. The valve is linked to the drive linkage so it is opened when the stroke amplitude exceeds a selected limit. This allows compressed gas to enter the spring, increase its spring constant, thus opposing stroke increase and reducing the phase lead of the displacer ahead of the piston to reduce power output and match it to a reduced load power demand. 6 figs.

  13. Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices

    E-Print Network [OSTI]

    Tolbert, Leon M.

    Two-Phase Cooling Method Using R134a Refrigerant to Cool Power Electronic Devices Jeremy B, TN 37932 Abstract This paper presents a two-phase cooling method using R134a refrigerant). The cooling method involves submerging PE devices in an R134a bath, which limits the junction temperature

  14. Measurements with reticulated vitreous carbon stacks in thermoacoustic prime movers and refrigerators

    SciTech Connect (OSTI)

    Adeff, J.A.; Hofler, T.J.; Atchley, A.A.; Moss, W.C.

    1998-07-01

    Reticulated vitreous carbon has been successfully used as a stack material in thermoacoustic prime movers and refrigerators. It is a rigid glassy carbon material, with a porous spongelike structure. Test results indicate peak pressure amplitudes of up to 32{percent} in a prime mover, and refrigeration performance comparable to that of a traditional plastic roll stack. {copyright} {ital 1998 Acoustical Society of America.}

  15. 2180, Page 1 International Refrigeration and Air Conditioning Conference at Purdue, July 14-17, 2014

    E-Print Network [OSTI]

    2180, Page 1 15th International Refrigeration and Air Conditioning Conference at Purdue, July 14 in Yashar and Lee (2013); they optimized the evaporator circuitry for a rooftop air- conditioning (RTU) unit;2180, Page 2 15th International Refrigeration and Air Conditioning Conference at Purdue, July 14-17, 2014

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    . (Keywords: CFCs; refrigeration; air conditioning; insulation; ozone depletion) Utilisation des to this global environmental issue by signing for R22 were obtained from the Air Conditioning and the MontrealFILE COPY DO NOT REMOVE Use of chlorofluorocarbons in refrigeration, insulation and mobile air

  17. M. Bahrami ENSC 461 (S 11) Tutorial 4 1 ENSC 461 Tutorial, Week#6 Refrigeration Cycle

    E-Print Network [OSTI]

    Bahrami, Majid

    M. Bahrami ENSC 461 (S 11) Tutorial 4 1 ENSC 461 Tutorial, Week#6 ­ Refrigeration Cycle A large of the refrigerant, b) the power input to the compressor, c) the mass flow rate of the cooling water, and d) the rate to represent the system Condenser Evaporator LQ 4 3 2 1 Wc QH Expansion Valve Compressor = 100kW High Pressure

  18. 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 for energy savings without extra loss of food quality. We also show that by utilizing the relatively slow

  19. The Impact of Control Technology on the Demand Response Potential of California Industrial Refrigerated Facilities Final Report

    E-Print Network [OSTI]

    Scott, Doug

    2014-01-01

    and Automated Demand Response in Industrial RefrigeratedDemand Response .. ..Technology on the Demand Response Potential of California

  20. HFC-134A and HCFC-22 supermarket refrigeration demonstration and laboratory testing. Phase I. Final report

    SciTech Connect (OSTI)

    1996-04-01

    Aspen Systems and a team of nineteen agencies and industry participants conducted a series of tests to determine the performance of HFC-134a, HCFC-22, and CFC-502 for supermarket application. This effort constitutes the first phase of a larger project aimed at carrying out both laboratory and demonstration tests of the most viable HFC refrigerants and the refrigerants they replace. The results of the Phase I effort are presented in the present report. The second phase of the project has also been completed. It centered on testing all viable HFC replacement refrigerants for CFC-502. These were HFC-507, HFC-404A, and HFC-407A. The latter results are published in the Phase II report for this project. As part of Phase I, a refrigeration rack utilizing a horizontal open drive screw compressor was constructed in our laboratory. This refrigeration rack is a duplicate of one we have installed in a supermarket in Clifton Park, NY.

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

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

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

  2. Applications of statistical models to synchronous climate variables: a case study of temperature and dew point for College Station, Texas 

    E-Print Network [OSTI]

    O'Brien, Charles F.

    1995-01-01

    transformations. Generally speaking, temperature, dew point, and dew point depression values could be transformed to resemble a bivariate normal distribution. Of the 288 cases (6 mos. x 24 hrs. x 2 moisture variables) applied to the bivariate normal distribution...

  3. Discovering the relevant variables in a large clinical database by back-fitting fixed effects in a mixed linear model

    E-Print Network [OSTI]

    Boyer, Edmond

    Discovering the relevant variables in a large clinical database by back-fitting fixed effects are investigates according to a planned protocol and with a predetermined cohort. They also differ from basic

  4. Combined Experimental and Statistical Model to Understand the Role of Anatomical and Implant Alignment Variables in Guiding Knee Joint Motion

    E-Print Network [OSTI]

    Mane, Amitkumar M.

    2012-05-31

    Kinematics variation is the inheritant part of the joint mechanics; factors such as patient anatomy, joint loading and implant alignments are all variable in nature. Improvement in the design of orthopedic implants requires ...

  5. Low-latitude Western North Atlantic climate variability during the past millennium : insights from proxies and models

    E-Print Network [OSTI]

    Saenger, Casey Pearce

    2009-01-01

    Estimates of natural climate variability during the past millennium provide a frame of reference in which to assess the significance of recent changes. This thesis investigates new methods of reconstructing low-latitude ...

  6. Waste Heat Powered Ammonia Absorption Refrigeration Unit for LPG Recovery

    SciTech Connect (OSTI)

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

    2008-06-20

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

  7. RECENT PROGRESS IN DYNAMIC PROCESS SIMULATION OF CRYOGENIC REFRIGERATORS

    SciTech Connect (OSTI)

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

    2008-03-16

    At the CEC 2005 a paper with the title 'Helium refrigerator design for pulsed heat load in Tokamaks' was presented. That paper highlighted the control requirements for cryogenic refrigerators to cope with the expected load variations of future nuclear fusion reactors. First dynamic computer simulations have been presented.In the mean time, the computer program is enhanced and a new series of process simulations are available. The new program considers not only the heat flows and the temperature variations within the heat exchangers, but also the variation of mass flows and pressure drops. The heat transfer numbers now are calculated in dependence of the flow speed and the gas properties. PI-controllers calculate the necessary position of specific valves for maintaining pressures, temperatures and the rotation speed of turbines.Still unsatisfactory is the fact, that changes in the process arrangement usually are attended by adjustments in the program code. It is the main objective of the next step of development a more flexible code which enables that any user defined process arrangements can be assembled by input data.

  8. Heat pump/refrigerator using liquid working fluid

    DOE Patents [OSTI]

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

    1982-01-01

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

  9. Refrigeration options for the Advanced Light Source Superbend Dipole Magnets

    SciTech Connect (OSTI)

    Green, M.A.; Hoyer, E.H.; Schlueter, R.D.; Taylor, C.E.; Zbasnik, J.; Wang, S.T.

    1999-07-09

    The 1.9 GeV Advance Light Source (ALS) at the Lawrence Berkeley National Laboratory (LBNL) produces photons with a critical energy of about 3.1 kev at each of its thirty-six 1.3 T gradient bending magnets. It is proposed that at three locations around the ring the conventional gradient bending magnets be replaced with superconducting bending magnets with a maximum field of 5.6 T. At the point where the photons are extracted, their critical energy will be about 12 keV. In the beam lines where the SuperBend superconducting magnets are installed, the X ray brightness at 20 keV will be increased over two orders of magnitude. This report describes three different refrigeration options for cooling the three SuperBend dipoles. The cooling options include: (1) liquid helium and liquid nitrogen cryogen cooling using stored liquids, (2) a central helium refrigerator (capacity 70 to 100 W) cooling all of the SuperBend magnets, (3) a Gifford McMahon (GM) cryocooler on each of the dipoles. This paper describes the technical and economic reasons for selecting a small GM cryocooler as the method for cooling the SuperBend dipoles on the LBNL Advanced Light Source.

  10. TransCom N[subscript 2]O model inter-comparison – Part 1: Assessing the influence of transport and surface fluxes on tropospheric N[subscript 2]O variability

    E-Print Network [OSTI]

    Thompson, R. L.

    We present a comparison of chemistry-transport models (TransCom-N2O) to examine the importance of atmospheric transport and surface fluxes on the variability of N2O mixing ratios in the troposphere. Six different models ...

  11. A Fourier series model to predict hourly heating and cooling energy use in commercial buildings with outdoor temperature as the only weather variable

    SciTech Connect (OSTI)

    Dhar, A. [Enron Corp., Houston, TX (United States); Reddy, T.A. [Drexel Univ., Philadelphia, PA (United States). Civil and Architectural Engineering Dept.; Claridge, D.E. [Texas A and M Univ., College Station, TX (United States). Energy Systems Lab.

    1999-02-01

    Accurate modeling of hourly heating and cooling energy use in commercial buildings can be achieved by a Generalized Fourier Series (GFS) approach involving weather variables such as dry-bulb temperature, specific humidity and horizontal solar flux. However, there are situations when only temperature data is available. The objective of this paper is to (i) describe development of a variant of the GFS approach which allows modeling both heating and cooling hourly energy use in commercial buildings with outdoor temperature as the only weather variable and (ii) illustrate its application with monitored hourly data from several buildings in Texas. It is found that the new Temperature based Fourier Series (TFS) approach (1) provides better approximation to heating energy use than the existing GFS approach, (ii) can indirectly account for humidity and solar effects in the cooling energy use, (iii) offers physical insight into the operating pattern of a building HVAC system and (iv) can be used for diagnostic purposes.

  12. ADVANCED UNDERGROUND GAS STORAGE CONCEPTS REFRIGERATED-MINED CAVERN STORAGE

    SciTech Connect (OSTI)

    1998-09-01

    Limited demand and high cost has prevented the construction of hard rock caverns in this country for a number of years. The storage of natural gas in mined caverns may prove technically feasible if the geology of the targeted market area is suitable; and economically feasible if the cost and convenience of service is competitive with alternative available storage methods for peak supply requirements. It is believed that mined cavern storage can provide the advantages of high delivery rates and multiple fill-withdrawal cycles in areas where salt cavern storage is not possible. In this research project, PB-KBB merged advanced mining technologies and gas refrigeration techniques to develop conceptual designs and cost estimates to demonstrate the commercialization potential of the storage of refrigerated natural gas in hard rock caverns. Five regions of the U.S.A. were studied for underground storage development and PB-KBB reviewed the literature to determine if the geology of these regions was suitable for siting hard rock storage caverns. Area gas market conditions in these regions were also studied to determine the need for such storage. Based on an analysis of many factors, a possible site was determined to be in Howard and Montgomery Counties, Maryland. The area has compatible geology and a gas industry infrastructure for the nearby market populous of Baltimore and Washington D.C.. As Gas temperature is lowered, the compressibility of the gas reaches an optimum value. The compressibility of the gas, and the resultant gas density, is a function of temperature and pressure. This relationship can be used to commercial advantage by reducing the size of a storage cavern for a given working volume of natural gas. This study looks at this relationship and and the potential for commercialization of the process in a storage application. A conceptual process design, and cavern design were developed for various operating conditions. Potential site locations were considered and a typical plant layout was developed. In addition a geomechanical review of the proposed cavern design was performed, evaluating the stability of the mine rooms and shafts, and the effects of the refrigerated gas temperatures on the stability of the cavern. Capital and operating cost estimates were also developed for the various temperature cases considered. The cost estimates developed were used to perform a comparative market analysis of this type of gas storage system to other systems that are commercially used in the region of the study.

  13. A simple model for 1/f spectra in heart rate variability James P. Gleesona and Aneta Stefanovskab

    E-Print Network [OSTI]

    Gleeson, James P.

    , Lancaster, LA1 4YB, UK. ABSTRACT Heart rate variability (HRV) measures cycle-to-cycle correlations of a sum of uncoupled sinusoidal oscillators with slightly different frequencies, has a HRV spectrum with a 1/f scaling over a range of frequencies. This implies that the appearance of 1/f HRV spectra

  14. Modeling and Control of Discrete Event Systems Using Finite State Machines with Variables and Their Applications in Power Grids

    E-Print Network [OSTI]

    Zhang, Hongwei

    of electric power grids. Keywords: control synthesis; discrete event systems; finite state machines; PHEVModeling and Control of Discrete Event Systems Using Finite State Machines with Variables,e , and Hongwei Zhangf a Department of Electrical and Computer Engineering, Wayne State University, Detroit, MI

  15. Intraseasonal to annual propagating variability in a medium-resolution regional model simulation of the South Eastern Pacific

    E-Print Network [OSTI]

    ) and Yves duPenhoat (1) (1) LEGOS/IRD - Toulouse, (2) CEAZA, Coquimbo, Chile, (3) LOCEAN/IRD-Paris (4) DGEO the energy is transmitted both from the open boundaries along the coast and to the inner basin and from variability display peaks in the inner basin between 33°S and 15°S and a minimum in a `shadow zone' just off

  16. Effects of temperature on desiccant catalysis of refrigerant and lubricant decomposition. Final report

    SciTech Connect (OSTI)

    Rohatgi, N.D.T.

    1998-06-01

    Accelerated aging at high temperatures (149 C) for short aging times (28 days) is effective in screening the compatibility of different materials in refrigeration systems. However, in actual applications temperatures are usually lower and operating times much longer. Therefore plots to allow for interpolation or extrapolation of experimental data to actual operating conditions are needed. In the current study, aging of refrigerant/lubricant/desiccant/metal systems was conducted at five different temperatures, and for each temperature at four different aging times. The data collected from this study provided plots relating refrigerant or lubricant decomposition to aging time, aging temperature, and type of desiccant, which can be used for interpolation or extrapolation.

  17. Regeneration tests of a room temperature magnetic refrigerator and heat pump

    E-Print Network [OSTI]

    Brown, G V

    2014-01-01

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

  18. Triple-effect absorption refrigeration system with double-condenser coupling

    DOE Patents [OSTI]

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

    1993-04-27

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

  19. Triple-effect absorption refrigeration system with double-condenser coupling

    DOE Patents [OSTI]

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

    1993-01-01

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

  20. Estimation of two-parameter multilevel item response models with predictor variables: simulation and substantiation for an urban school district 

    E-Print Network [OSTI]

    Natesan, Prathiba

    2009-05-15

    IRT models. However, models such as 2-PL MLIRT models have not been studied yet. This dissertation consists of two studies, a simulation and a substantiation for an urban school district dataset. The simulation study tested the performance...

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

    E-Print Network [OSTI]

    Zheng, A.; Gu, J.

    2006-01-01

    In this paper, according to practical consideration, a new solar powered rotary solid adsorption refrigerator system adopting activated carbon fibre + ethanol as its adsorption pair has been designed with higher performance. ...

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

    E-Print Network [OSTI]

    Lekov, Alex

    2009-01-01

    48 hrs if doors o Cold Storage (Ammonia chiller 1: 450 ton,o Building 2: Cold storage, 54000 sq ft (2 ammonia chillersAmmonia is the most commonly used refrigerant for food processing and storage

  3. Patterns of Refrigerant Use Resulting From Regulations Designed to Protect the Environment 

    E-Print Network [OSTI]

    Thomas, R.

    1996-01-01

    . These difficulties can be turned into a competitive advantage if the contractor understands the source of the difficulties. This paper explores some of the industry wide problems and solutions. The new refrigerants are many and are covered by venting, recycling...

  4. Fluctuations in ASHRAE Refrigerant Physical Properties and the Effect on Single and Two Phase Flow 

    E-Print Network [OSTI]

    Nagy, Paul

    2014-11-17

    handbook edition is released. Thirteen properties (liquid and vapor viscosity, thermal conductivity, specific heat, enthalpy, surface tension, density and specific volume) from five widely used refrigerants (R-22, R-134a, R-410a, R-152a, R-600a...

  5. Global emissions of refrigerants HCFC-22 and HFC-134a: Unforeseen seasonal contributions

    E-Print Network [OSTI]

    Xiang, Bin

    HCFC-22 (CHClF[subscript 2]) and HFC-134a (CH[subscript 2]FCF[subscript 3]) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ...

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

    E-Print Network [OSTI]

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

    1994-01-01

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

  7. A Systems Approach to Optimize the Operation of a Refrigeration Unit at a Chemical Plant 

    E-Print Network [OSTI]

    Papar, R.; Zugibe, K.; Heitler, J.

    2005-01-01

    This paper focuses on the ongoing system level analysis and the optimization results of two steamturbine driven refrigeration units at the Dow Chemical company Peroxymerics (PXC) plant located at St. Charles Operations in Hahnville, LA. Six-sigma...

  8. Ongoing Commissioning of a high efficiency supermarket with a ground coupled carbon dioxide refrigeration plant 

    E-Print Network [OSTI]

    Rehault, N.; Kalz, D.

    2012-01-01

    developed a new supermarket concept combining several innovative solutions for the refrigeration, lighting and heating/ventilation with the goal to reduce the energy consumption by about 30% compared to a standard subsidiary. A highly insulated building...

  9. Heat pump simulation model and optimal variable-speed control for a wide range of cooling conditions

    E-Print Network [OSTI]

    Zakula, Tea

    2010-01-01

    The steady-state air-to-air heat pump model presented in this thesis was developed from the first principles. The main objective was to develop a heat pump model that can be used as a part of larger simulation models, and ...

  10. Optimal threshold policies in a workload model with a variable number of service phases per job \\Lambda

    E-Print Network [OSTI]

    Brouns, Gido

    models, admission and termination control, optimal threshold policies, Markov decision processes. 1 systems. The basic principle of performance optimization is the question of how to control some type of models for the optimal control of queueing systems. Emphasis is laid on models based on Markov decision

  11. Overview of Air Liquide refrigeration systems between 1.8 K and 200 K

    SciTech Connect (OSTI)

    Gondrand, C.; Durand, F.; Delcayre, F.; Crispel, S. [AL-AT, 2 rue de Clémencières, 38360 Sassenage (France); Baguer, G. M. Gistau [CRYOGUY, 44, chemin de la Buisse, 38330 Biviers (France)

    2014-01-29

    Cryogenic refrigeration systems are necessary for numerous applications. Gas purification and distillation require temperatures between 15 K and 200 K depending on the application, space simulation chambers down to 15 K, superconductivity between 1.8 K and up to 75 K (magnets, cavities or HTS devices like cables, FCL, SMES, etc), Cold Neutron Sources between 15 and 20 K, etc. Air Liquide Advanced Technologies is designing and manufacturing refrigerators since 60 years to satisfy those needs. The step by step developments achieved have led to machines with higher efficiency and reliability. In 1965, reciprocating compressors and Joule Thomson expansion valves were used. In 1969, centripetal expanders began to be used. In 1980, oil lubricated screw compressors took the place of reciprocating compressors and a standard range of Claude cycle refrigerators was developed: the HELIAL series. 1980 was also the time for cryogenic centrifugal compressor development. In 2011, driven by the need for lower operational cost (high efficiency and low maintenance), cycle oil free centrifugal compressors on magnetic bearings were introduced instead of screw compressors. The power extracted by centripetal expanders was recovered. Based on this technology, a range of Turbo-Brayton refrigerators has been designed for temperatures between 40 K and 150 K. On-going development will enable widening the range of Turbo-Brayton refrigerators to cryogenic temperatures down to 15 K.. Cryogenic centrifugal circulators have been developed in order to answer to an increasing demand of 4 K refrigerators able to distribute cold power.

  12. Statistical characteristics of cloud variability. Part 2: Implication for parameterizations of microphysical and radiative transfer processes in climate models

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Dong; Liu, Yangang

    2014-09-27

    The effects of subgrid cloud variability on grid-average microphysical rates and radiative fluxes are examined by use of long-term retrieval products at the Tropical West Pacific, Southern Great Plains, and North Slope of Alaska sites of the Department of Energy's Atmospheric Radiation Measurement program. Four commonly used distribution functions, the truncated Gaussian, Gamma, lognormal, and Weibull distributions, are constrained to have the same mean and standard deviation as observed cloud liquid water content. The probability density functions are then used to upscale relevant physical processes to obtain grid-average process rates. It is found that the truncated Gaussian representation results inmore »up to 30% mean bias in autoconversion rate, whereas the mean bias for the lognormal representation is about 10%. The Gamma and Weibull distribution function performs the best for the grid-average autoconversion rate with the mean relative bias less than 5%. For radiative fluxes, the lognormal and truncated Gaussian representations perform better than the Gamma and Weibull representations. The results show that the optimal choice of subgrid cloud distribution function depends on the nonlinearity of the process of interest, and thus, there is no single distribution function that works best for all parameterizations. Examination of the scale (window size) dependence of the mean bias indicates that the bias in grid-average process rates monotonically increases with increasing window sizes, suggesting the increasing importance of subgrid variability with increasing grid sizes.« less

  13. Statistical characteristics of cloud variability. Part 2: Implication for parameterizations of microphysical and radiative transfer processes in climate models

    SciTech Connect (OSTI)

    Huang, Dong; Liu, Yangang

    2014-09-27

    The effects of subgrid cloud variability on grid-average microphysical rates and radiative fluxes are examined by use of long-term retrieval products at the Tropical West Pacific, Southern Great Plains, and North Slope of Alaska sites of the Department of Energy's Atmospheric Radiation Measurement program. Four commonly used distribution functions, the truncated Gaussian, Gamma, lognormal, and Weibull distributions, are constrained to have the same mean and standard deviation as observed cloud liquid water content. The probability density functions are then used to upscale relevant physical processes to obtain grid-average process rates. It is found that the truncated Gaussian representation results in up to 30% mean bias in autoconversion rate, whereas the mean bias for the lognormal representation is about 10%. The Gamma and Weibull distribution function performs the best for the grid-average autoconversion rate with the mean relative bias less than 5%. For radiative fluxes, the lognormal and truncated Gaussian representations perform better than the Gamma and Weibull representations. The results show that the optimal choice of subgrid cloud distribution function depends on the nonlinearity of the process of interest, and thus, there is no single distribution function that works best for all parameterizations. Examination of the scale (window size) dependence of the mean bias indicates that the bias in grid-average process rates monotonically increases with increasing window sizes, suggesting the increasing importance of subgrid variability with increasing grid sizes.

  14. The hydrology of malaria : field observations and mechanistic modeling of the malaria transmission response to environmental climatic variability

    E-Print Network [OSTI]

    Bomblies, Arne

    2009-01-01

    A coupled HYDrology, Entomology and MAlaria Transmission Simulator (HYDREMATS) has been developed. The model simulates the hydrological and climatological determinants of malaria transmission mechanistically and at high ...

  15. Energy Savings in Refrigerated Walk-In Boxes

    SciTech Connect (OSTI)

    Webster, Tom

    1998-06-01

    The purpose of this technical brief is to provide an overview of the results of an assessment of a technique for saving energy in refrigerated walk-in coolers, and to evaluate the potential for this technology in Federal facilities. The focus of this study was on a single manufacturer of the technology, Nevada Energy Control Systems, Inc. (Necsi); no other vendors for this technology could be found. Previous studies were inconclusive about the overall efficacy of this technique due to uncertainties in a number of areas. [1] Previous evaluations also lacked the benefit of the results from recent manufacturer sponsored tests and did not address some fundamental issues about the overall efficacy of this technology that are critical to understanding its potential. The primary objective of this assessment was to determine if the previous studies combined with recent vendor sponsored test results substantiate the manufacturer's claims that this is a cost effective energy saving technique with significant potential in Federal facilities. Secondary objectives included evaluation of intangible benefits such as equipment life and reliability issues, and humidity and airflow effects on product.

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

    E-Print Network [OSTI]

    Dyer, Bill

    , fans, compressors, heat exchangers, heaters, refrigerators, etc.) of heating, ventilation, air Load - Introduction HVAC Systems Comfort and Health Solar Radiation Radiant Time Series Method Moist

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

    Office of Energy Efficiency and Renewable Energy (EERE)

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

  18. Semi-Empirical Screw Compressor Chiller Model 

    E-Print Network [OSTI]

    Nelson, I. C.; Culp, C.; Graves, R. D.

    2008-01-01

    temperature difference between the outlet and inlet of the evaporator. The required measured parameters of the model are the evaporator water inlet and outlet temperatures and mass flow, the refrigerant temperature in the condenser and evaporator...

  19. A simple hidden variable experiment

    E-Print Network [OSTI]

    Arnold Neumaier

    2007-06-22

    An experiment is described which proves, using single photons only, that the standard hidden variables assumptions (commonly used to derive Bell inequalities) are inconsistent with quantum mechanics. The analysis is very simple and transparent. In particular, it demonstrates that a classical wave model for quantum mechanics is not ruled out by experiments demonstrating the violation of the traditional hidden variable assumptions.

  20. Impact of subgrid-scale radiative heating variability on the stratocumulus-to-trade cumulus transition in climate models

    SciTech Connect (OSTI)

    Xiao, Heng; Gustafson, William I.; Wang, Hailong

    2014-04-29

    Subgrid-scale interactions between turbulence and radiation are potentially important for accurately reproducing marine low clouds in climate models. To better understand the impact of these interactions, the Weather Research and Forecasting (WRF) model is configured for large eddy simulation (LES) to study the stratocumulus-to-trade cumulus (Sc-to-Cu) transition. Using the GEWEX Atmospheric System Studies (GASS) composite Lagrangian transition case and the Atlantic Trade Wind Experiment (ATEX) case, it is shown that the lack of subgrid-scale turbulence-radiation interaction, as is the case in current generation climate models, accelerates the Sc-to-Cu transition. Our analysis suggests that in cloud-topped boundary layers subgrid-scale turbulence-radiation interactions contribute to stronger production of temperature variance, which in turn leads to stronger buoyancy production of turbulent kinetic energy and helps to maintain the Sc cover.

  1. ARTI Refrigerant Database. [Quarterly progress report, 1 July 1993--30 September 1993

    SciTech Connect (OSTI)

    Calm, J.M.

    1993-11-28

    The Refrigerant Database consolidates and facilitates access to information to assist industry in developing equipment using alternative refrigerants. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on R-32, R-123, R-124, R-125, R-134, R134a, R-141b, R-142b, R-143a, R-152a, R-227ea, 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, polyol 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. They are included to accelerate availability of the information and will be completed or replaced in future updates.

  2. Evaluation of EHD enhancement and thermoacoustic refrigeration for naval applications. Technical report, Jul-Sep 91

    SciTech Connect (OSTI)

    Memory, S.B.

    1991-12-01

    An evaluation has been made of two different techniques which could prove valuable for Naval refrigeration needs in the future. The first is electrohydrodynamic (EHD) enhancement of pool boiling and condensation heat transfer; this has been shown to provide significant enhancements for both modes of heat transfer under certain conditions and could provide increases in efficiency of present vapor-compression systems. EHD techniques are quite advanced and prototype condenser and evaporator bundles are currently being tested. The second technique is an alternative refrigeration technology called thermoacoustic refrigeration; alternative technologies have become increasingly attractive over recent years due to environmental concerns over CFCs. Thermoacoustic refrigeration uses acoustic power to pump heat from a low temperature source to a high temperature sink. It is still in the early stages of development and can presently accommodate only small thermal loads. However, its general principles of operation have been proven and its resent capacity and efficiency limitations are not seen as a problem in the long term. Electrohydrodynamic Enhancement, Boiling and Condensation, Thermoacoustic Refrigeration.

  3. Development of a Variable-Speed Residential Air-Source Integrated Heat Pump

    SciTech Connect (OSTI)

    Rice, C Keith [ORNL] [ORNL; Shen, Bo [ORNL] [ORNL; Munk, Jeffrey D [ORNL] [ORNL; Ally, Moonis Raza [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL

    2014-01-01

    A residential air-source integrated heat pump (AS-IHP) is under development in partnership with a U.S. manufacturer. A nominal 10.6 kW (3-ton) cooling capacity variable-speed unit, the system provides both space conditioning and water heating. This multi-functional unit can provide domestic water heating (DWH) in either full condensing (FC) (dedicated water heating or simultaneous space cooling and water heating) or desuperheating (DS) operation modes. Laboratory test data were used to calibrate a vapor-compression simulation model for each mode of operation. The model was used to optimize the internal control options for efficiency while maintaining acceptable comfort conditions and refrigerant-side pressures and temperatures within allowable operating envelopes. Annual simulations were performed with the AS-IHP installed in a well-insulated house in five U.S. climate zones. The AS-IHP is predicted to use 45 to 60% less energy than a DOE minimum efficiency baseline system while meeting total annual space conditioning and water heating loads. Water heating energy use is lowered by 60 to 75% in cold to warmer climates, respectively. Plans are to field test the unit in Knoxville, TN.

  4. The effect of variable atmospheric forcing on oceanic subduction of a passive tracer in a numerical model: Implications for global warming

    SciTech Connect (OSTI)

    Horsfall, F.; Bleck, R.; Hanson, H.P.

    1997-11-01

    This study addresses the issue of the ocean`s response to the changing climate. The objectives is to determine the effect of variable atmospheric forcing on the ocean on decadal time scales, specifically on the subduction of a passive tracer. In the context of the model used in this study, this tracer is {open_quotes}tagged{close_quotes} water that is subducted into the thermocline and into the deep ocean. The model used in this study is the Miami Isopycnic Coordinate Ocean Model which has a realistic Atlantic domain from 20{degrees}S to 60{degrees}N. There are twelve model layers, the first (top) layer being the thermodynamically active mixed layer and the lower eleven layers all having constant potential density ({sigma}{sub {theta}}). The atmospheric forcing changes vary latitudinally, allowing for a maximum increase in wind at midlatitudes and a maximum increase in temperature at the poles. In these experiments, it was found that wind speed and temperature effects dominate in bringing about changes in mixed-layer depth and in tracer penetration at high latitudes, with wind speed effects having the greater weight. It is apparent from the results that the weakening of the North Atlantic thermohaline circulation is dependent on the atmospheric changes in air temperature and in the wind field. 11 refs., 2 figs.

  5. Moving-Boundary Heat Exchanger Models with Variable Outlet Phase, ASME Journal of Dynamic Systems, Measurement, and Control 

    E-Print Network [OSTI]

    Eldredge, B.D; Rasmussen, B.P.; Alleyne, A.

    2008-01-01

    a w r yna 115 uid 1 c A s c s p e r t i p m t e e i c number of elements results in a dynamically complex model that may be computationally expensive and is unsuitable for model- based control design ?3?. e g l n d t m i t b r G a d principles...://www.asme.org/terms/Terms_Use.cfm ?L LT ???Acs? ?t dz = Acs ? d dt?L LT ???dz + ?gL? 1 ? ?31? A t E p N c e B A v A T I a E E ? L LT ??m?h? ?z dz = m?outhout ? m?inthint ?40? J l Dow ESL-PA-08-11-011 1 ssume that the lumped density can be evaluated as a function of he void fraction...

  6. Optimization of Magnetic Refrigerators by Tuning the Heat Transfer Medium and Operating Conditions

    E-Print Network [OSTI]

    Ghahremani, Mohammadreza; Bennett, Lawrence H; Della Torre, Edward

    2015-01-01

    A new experimental test bed has been designed, built, and tested to evaluate the effect of the systems parameters on a reciprocating Active Magnetic Regenerator (AMR) near room temperature. Bulk gadolinium was used as the refrigerant, silicon oil as the heat transfer medium, and a magnetic field of 1.3 T was cycled. This study focuses on the methodology of single stage AMR operation conditions to get a higher temperature span near room temperature. Herein, the main objective is not to report the absolute maximum attainable temperature span seen in an AMR system, but rather to find the systems optimal operating conditions to reach that maximum span. The results of this research show that there is a optimal operating frequency, heat transfer fluid flow rate, flow duration, and displaced volume ratio in an AMR system. By optimizing these parameters the refrigeration performance increased by 24%. It is expected that such optimization will permit the design of a more efficient magnetic refrigeration system.

  7. Measurement of solubility, viscosity, and density of R-410A refrigerant/lubricant mixtures

    SciTech Connect (OSTI)

    Cavestri, R.C.; Schafer, W.R.

    2000-07-01

    Measurements of the refrigerant vapor/liquid lubricant equilibrium viscosity reduction of four polyolester lubricants, viscosity grades 32 and 68 ISO VG, with the refrigerant R-410A were taken between {minus}13 F and 257 F and up to 700 psia. A high and low miscibility grade polyolester was analyzed for each viscosity. The viscosity, density, and composition of the solubilized gas mixture in solution with the lubricant was obtained with constant gas vapor composition in the viscometer head space. This refrigerant has a very small temperature glide but is considered a zeotropic blend nonetheless. The fractionation data presented were obtained from individual isothermal measurements. The isotherm for each temperature detailed the composition of the equilibrium gas fractionation of R-32 and R-125 in the lubricant, mixed vapor pressure, concentration of the total mixed blend (percent by weight) in the lubricant, and viscosity in centipoise (cP) and centistokes (cSt).

  8. High frequency thermoacoustic refrigerator. Annual summary report, 2 September 1993-31 May 1994

    SciTech Connect (OSTI)

    Symko, O.G.

    1994-06-16

    A small thermoacoustic refrigerator was developed for operation at 5 kHz. Its main components are a piezoelectric driver of the bimorph type, a cotton wool stack, a 1/2-wave resonator (operated at its 3rd harmonic), and photolithographically processed copper heat exchangers. Tests with air at 1 atmosphere as the working gas produced a temperature difference Delta T across the stack of 32 deg C in 4 seconds for an acoustic power input level of 160 dB. The refrigerator did not have thermal insulation. Improved performance is expected with pressurized helium gas and helium-xenon mixtures. The performance of this refrigerator and its small size make it attractive for applications in high speed electronics and possibly IR detectors.

  9. High frequency thermoacoustic refrigerator. Annual summary report, 1 June 1994-31 May 1995

    SciTech Connect (OSTI)

    Symko, O.G.

    1995-08-15

    Results are presented on the development of a high frequency thermoacoustic refrigerator and its performance. The device consists of a piezoelectric driver, operated around 5kHz, which is coupled to a cylindrical resonator containing air at 1 atmosphere as the compressible fluid. For sound levels of 155dB at the stack, a maximum T of 41 C was reached across a cotton wool stack 4mm long. A cooling power of 1.2 watt was achieved with a coefficient of performance of 3. This simple and lightweight refrigerator shows promise for cooling of small samples and electronic components. The performance of this type of refrigerator at high frequencies leads to high efficiency and power density. Research is aimed at improving its performance by optimizing some of the critical parameters such as the sound level and the thermal interface between stack and heat exchangers.

  10. Thermodynamic improvements for the space thermo-acoustic refrigerator (STAR). Master's thesis

    SciTech Connect (OSTI)

    Susalla, M.P.

    1988-06-01

    The objective of the STAR project is to test and space qualify a new continuous-cycle cryogenic refrigeration system for cooling of sensors and electronics which is based upon the newly discovered thermoacoustic heat-pumping effect. The new refrigerator has no sliding seals, a cycle frequency of about 300 Hz, and uses acoustic resonance to enhance the overall power density and efficiency. This thesis is concerned specifically with the design and testing of the thermodynamic element (or stack), which is responsible for the thermo-acoustic power conversion, and the testing of binary inert-gas mixtures as working fluids. Using the refrigerator's coefficient of performance relative to the ideal Carnot coefficient of performance as a measure of efficiency, a 93% improvement over previous designs.

  11. Superfluid stirling refrigerator: A new method for cooling below 1 Kelvin

    SciTech Connect (OSTI)

    Kotsubo, V.; Swift, G.W.

    1990-01-01

    We have invented and built a new type of cryocooler, which we call the superfluid Stirling refrigerator (SSR). The first prototype reached 0.6 K from a starting temperature of 1.2 K. The working fluid of the SSR is the {sup 3}He solute in a superfluid {sup 3}He--{sup 4}He solution. At low temperatures, the superfluid {sup 4}He is in its quantum ground state, and therefore is thermodynamically inert, while the {sup 3}He solute has the thermodynamic properties of a dense ideal gas. Thus, in principle, any refrigeration cycle that can use an ideal gas can also use the {sup 3}He solute as working fluid. In our SSR prototype, bellows-sealed superleak pistons driven by a room-temperature camshaft work on the {sup 3}He solute. Ultimately, we anticipate elimination of moving parts by analogy with pulse-tube refrigeration. 15 refs., 6 figs.

  12. Method using CO for extending the useful shelf-life of refrigerated red blood cells

    DOE Patents [OSTI]

    Bitensky, Mark W. (Los Alamos, NM)

    1995-01-01

    Method using CO for extending the useful shelf-life of refrigerated red blood cells. Carbon monoxide is utilized for stabilizing hemoglobin in red blood cells to be stored at low temperature. Changes observed in the stored cells are similar to those found in normal red cell aging in the body, the extent thereof being directly related to the duration of refrigerated storage. Changes in cell buoyant density, vesiculation, and the tendency of stored cells to bind autologous IgG antibody directed against polymerized band 3 IgG, all of which are related to red blood cell senescence and increase with refrigerated storage time, have been substantially slowed when red blood cells are treated with CO. Removal of the carbon monoxide from the red blood cells is readily and efficiently accomplished by photolysis in the presence of oxygen so that the stored red blood cells may be safely transfused into a recipient.

  13. Method using CO for extending the useful shelf-life of refrigerated red blood cells

    DOE Patents [OSTI]

    Bitensky, M.W.

    1995-12-19

    A method is disclosed using CO for extending the useful shelf-life of refrigerated red blood cells. Carbon monoxide is utilized for stabilizing hemoglobin in red blood cells to be stored at low temperature. Changes observed in the stored cells are similar to those found in normal red cell aging in the body, the extent thereof being directly related to the duration of refrigerated storage. Changes in cell buoyant density, vesiculation, and the tendency of stored cells to bind autologous IgG antibody directed against polymerized band 3 IgG, all of which are related to red blood cell senescence and increase with refrigerated storage time, have been substantially slowed when red blood cells are treated with CO. Removal of the carbon monoxide from the red blood cells is readily and efficiently accomplished by photolysis in the presence of oxygen so that the stored red blood cells may be safely transfused into a recipient. 5 figs.

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

    SciTech Connect (OSTI)

    Ohadi, M. M.

    1999-09-01

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

  15. An inverse method for calculation of thermal inertia and heat gain in air conditioning and refrigeration systems

    E-Print Network [OSTI]

    Bahrami, Majid

    An inverse method for calculation of thermal inertia and heat gain in air conditioning for estimation of thermal inertia and heat gain in air conditioning and refrigeration systems using on Ltd. All rights reserved. 1. Introduction Heating, Ventilation, Air Conditioning, and Refrigeration

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

    E-Print Network [OSTI]

    Bahrami, Majid

    ) for vehicle air conditioning and refrigeration (A/C­R) applications. Adsorber beds should be specificallyAssessment of adsorber bed designs in waste-heat driven adsorption cooling systems for vehicle air conditioning and refrigeration Amir Sharafian, Majid Bahrami n Laboratory for Alternative Energy Conversion

  17. STUDIES ON THE USE OF CARBON DIOXIDE DISSOLVED IN REFRIGERATED BRINE FOR THE PRESERVATION OF WHOLE FISH

    E-Print Network [OSTI]

    STUDIES ON THE USE OF CARBON DIOXIDE DISSOLVED IN REFRIGERATED BRINE FOR THE PRESERVATION OF WHOLE in rockfish and chum salmon of dissolving carbon dioxide in brine. Storing the fish in the refrigerated brine treated with carbon dioxide inhibited the growth of the bacteria, retarded the rate at which the fish

  18. ISSUANCE 2015-12-04: Energy Conservation Standards and Test Procedure for Miscellaneous Refrigeration Products: Notice of Data Availability; Request for Information

    Broader source: Energy.gov [DOE]

    Energy Conservation Standards and Test Procedure for Miscellaneous Refrigeration Products: Notice of Data Availability; Request for Information

  19. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    SciTech Connect (OSTI)

    Abdelaziz, Omar; Shrestha, Som S.; Munk, Jeffrey D.; Linkous, Randall Lee; Goetzler, William; Guernsey, Matt; Kassuga, Theo

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  20. Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures, Part II: Experimental comparison and verification of methods. Volume 2, In situ conductivity data

    SciTech Connect (OSTI)

    Kauffman, R.

    1995-09-01

    Data are presented for the accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures.

  1. ISSUANCE 2015-02-03: Energy Efficiency Program for Residential Products: Energy Conservation Standards for Miscellaneous Refrigeration Products, Reopening of Public Comment Period

    Broader source: Energy.gov [DOE]

    Energy Efficiency Program for Residential Products: Energy Conservation Standards for Miscellaneous Refrigeration Products, Reopening of Public Comment Period

  2. Investigation on the two-stage active magnetic regenerative refrigerator for liquefaction of hydrogen

    SciTech Connect (OSTI)

    Park, Inmyong; Park, Jiho; Jeong, Sangkwon; Kim, Youngkwon

    2014-01-29

    An active magnetic regenerative refrigerator (AMRR) is expected to be useful for hydrogen liquefaction due to its inherent high thermodynamic efficiency. Because the temperature of the cold end of the refrigerator has to be approximately liquid temperature, a large temperature span of the active magnetic regenerator (AMR) is indispensable when the heat sink temperature is liquid nitrogen temperature or higher. Since magnetic refrigerants are only effective in the vicinity of their own transition temperatures, which limit the temperature span of the AMR, an innovative structure is needed to increase the temperature span. The AMR must be a layered structure and the thermophysical matching of magnetic field and flow convection effects is very important. In order to design an AMR for liquefaction of hydrogen, the implementation of multi-layered AMR with different magnetic refrigerants is explored with multi-staging. In this paper, the performance of the multi-layered AMR using four rare-earth compounds (GdNi{sub 2}, Gd{sub 0.1}Dy{sub 0.9}Ni{sub 2}, Dy{sub 0.85}Er{sub 0.15}Al{sub 2}, Dy{sub 0.5}Er{sub 0.5}Al{sub 2}) is investigated. The experimental apparatus includes two-stage active magnetic regenerator containing two different magnetic refrigerants each. A liquid nitrogen reservoir connected to the warm end of the AMR maintains the temperature of the warm end around 77 K. High-pressure helium gas is employed as a heat transfer fluid in the AMR and the maximum magnetic field of 4 T is supplied by the low temperature superconducting (LTS) magnet. The temperature span with the variation of parameters such as phase difference between magnetic field and mass flow rate of magnetic refrigerants in AMR is investigated. The maximum temperature span in the experiment is recorded as 50 K and several performance issues have been discussed in this paper.

  3. Simulation of the intraseasonal variability over the Eastern...

    Office of Scientific and Technical Information (OSTI)

    Simulation of the intraseasonal variability over the Eastern Pacific ITCZ in climate models Citation Details In-Document Search Title: Simulation of the intraseasonal variability...

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

    E-Print Network [OSTI]

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

    2006-01-01

    is then throttled to the high-pressure receiver (HPR). A portion of the high-pressure liquid ammonia is directed to the ice making system to remove heat from the chilled water system where the ammonia flashes to gas after extracting the heat from the ice storage... on the assessed data. This paper will: provide an overview of typical industrial ammonia refrigeration systems; discuss the various components of the system including the compressors, condensers, evaporators and controls that make up a refrigeration system...

  5. Natural Gas Variability In California: Environmental Impacts And Device Performance Combustion Modeling of Pollutant Emissions From a Residential Cooking Range

    SciTech Connect (OSTI)

    Tonse, S. R.; Singer, B. C.

    2011-07-01

    As part of a larger study of liquefied natural gas impacts on device performance and pollutant emissions for existing equipment in California, this report describes a cmoputer modeling study of a partially premixed flame issueing from a single cooktop burner port. The model consisted of a reactive computational fluid dynamics three-dimensional spatial grid and a 71-species chemical mechanism with propane combustion capability. Simulations were conducted with a simplified fuel mixture containing methane, ethane, and propane in proportions that yield properties similar to fuels distributed throughout much of California now and in recent years (baseline fuel), as well as with two variations of simulated liquefied natural gas blends. A variety of simulations were conducted with baseline fuel to explore the effect of several key parameters on pollutant formation and other flame characteristics. Simulations started with fuel and air issuing through the burner port, igniting, and continuing until the flame was steady with time. Conditions at this point were analyzed to understand fuel, secondary air and reaction product flows, regions of pollutant formation, and exhaust concentrations of carbon monoxide, nitric oxide and formaldehyde. A sensitivity study was conducted, varying the inflow parameters of this baseline gs about real-world operating conditions. Flame properties responded as expected from reactive flow theory. In the simulation, carbon monoxide levels were influenced more by the mixture's inflow velocity than by the gas-to-air ratio in the mixture issuing from the inflow port. Additional simulations were executed at two inflow conditions - high heat release and medium heat release - to examine the impact of replacing the baseline gas with two mixtures representative of liquefied natural gas. Flame properties and pollutant generation rates were very similar among the three fuel mixtures.

  6. Computer Modeling VRF Heat Pumps in Commercial Buildings using EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard

    2013-06-01

    Variable Refrigerant Flow (VRF) heat pumps are increasingly used in commercial buildings in the United States. Monitored energy use of field installations have shown, in some cases, savings exceeding 30% compared to conventional heating, ventilating, and air-conditioning (HVAC) systems. A simulation study was conducted to identify the installation or operational characteristics that lead to energy savings for VRF systems. The study used the Department of Energy EnergyPlus? building simulation software and four reference building models. Computer simulations were performed in eight U.S. climate zones. The baseline reference HVAC system incorporated packaged single-zone direct-expansion cooling with gas heating (PSZ-AC) or variable-air-volume systems (VAV with reheat). An alternate baseline HVAC system using a heat pump (PSZ-HP) was included for some buildings to directly compare gas and electric heating results. These baseline systems were compared to a VRF heat pump model to identify differences in energy use. VRF systems combine multiple indoor units with one or more outdoor unit(s). These systems move refrigerant between the outdoor and indoor units which eliminates the need for duct work in most cases. Since many applications install duct work in unconditioned spaces, this leads to installation differences between VRF systems and conventional HVAC systems. To characterize installation differences, a duct heat gain model was included to identify the energy impacts of installing ducts in unconditioned spaces. The configuration of variable refrigerant flow heat pumps will ultimately eliminate or significantly reduce energy use due to duct heat transfer. Fan energy is also studied to identify savings associated with non-ducted VRF terminal units. VRF systems incorporate a variable-speed compressor which may lead to operational differences compared to single-speed compression systems. To characterize operational differences, the computer model performance curves used to simulate cooling operation are also evaluated. The information in this paper is intended to provide a relative difference in system energy use and compare various installation practices that can impact performance. Comparative results of VRF versus conventional HVAC systems include energy use differences due to duct location, differences in fan energy when ducts are eliminated, and differences associated with electric versus fossil fuel type heating systems.

  7. Materials Compatibility and Lubricants Research on CFC-refrigerant substitutes. Quarterly MCLR Program technical progress report, July 1--September 30, 1995

    SciTech Connect (OSTI)

    Szymurski, S.R.; Hourahan, G.C.; Godwin, D.S.; Amrane, K.

    1995-10-01

    The Materials Compatibility and Lubricants Research (MCLR) program supports critical research to accelerate the introduction of CFC and HCFC refrigerant substitutes. The MCLR program addresses refrigerant and lubricant properties and materials compatibility. The primary elements of the work include data collection and dissemination, materials compatibility testing, and methods development. This report summarizes the research conducted during the third quarter of calendar year 1995 on the following projects: Thermophysical properties of HCFC alternatives; Compatibility of manufacturing process fluids with HFC refrigerants and ester lubricants; Compatibility of motor materials used in air-conditioning for retrofits with alternative refrigerants and lubricants; Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants; Products of motor burnouts; Accelerated test methods for predicting the life of motor materials exposed to refrigerant-lubricant mixtures; Investigation of flushing and clean-out methods; Investigation into the fractionation of refrigerant blends; Lean flammability limits as a fundamental refrigerant property; Effect of selected contaminants in AC and R equipment; Study of foaming characteristics; Study of lubricant circulation in systems; Evaluation of HFC-245ca for commercial use in low pressure chillers; Infrared analysis of refrigerant mixtures; Refrigerant database; Refrigerant toxicity survey; Thermophysical properties of HFC-32, HFC-123, HCFC-124 and HFC-125; Thermophysical properties of HFC-143a and HFC-152a; Theoretical evaluations of R-22 alternative fluids; Chemical and thermal stability of refrigerant-lubricant mixtures with metals; Miscibility of lubricants with refrigerants; Viscosity, solubility and density measurements of refrigerant-lubricant mixtures; Electrohydrodynamic enhancement of pool and in-tube boiling of alternative refrigerants; Accelerated screening methods; and more.

  8. Development and proof-testing of advanced absorption refrigeration cycle concepts

    SciTech Connect (OSTI)

    Modahl, R.J.; Hayes, F.C. (Trane Co., La Crosse, WI (United States). Applied Unitary/Refrigeration Systems Div.)

    1992-03-01

    The overall objectives of this project are to evaluate, develop, and proof-test advanced absorption refrigeration cycles that are applicable to residential and commercial heat pumps for space conditioning. The heat pump system is to be direct-fired with natural gas and is to use absorption working fluids whose properties are known. Target coefficients of performance (COPs) are 1.6 at 47{degrees}F and 1.2 at 17{degrees} in the heating mode, and 0.7 at 95{degree}F in the cooling mode, including the effect of flue losses. The project is divided into three phases. Phase I entailed the analytical evaluation of advanced cycles and included the selection of preferred concepts for further development. Phase II involves the development and testing of critical components and of a complete laboratory breadboard version of the selected system. Phase III calls for the development of a prototype unit and is contingent on the successful completion of Phase II. This report covers Phase I work on the project. In Phase 1, 24 advanced absorption cycle/fluid combinations were evaluated, and computer models were developed to predict system performance. COP, theoretical pump power, and internal heat exchange were calculated for each system, and these calculations were used as indicators of operating and installed costs in order to rank the relative promise of each system. The highest ranking systems involve the cycle concept of absorber/generator heat exchange, generator heat exchanger/absorber heat exchange, regeneration, and resorption/desorption, in combination with the NH{sub 3}/H{sub 2}O/LiBr ternary absorption fluid mixture or with the NH{sub 3}/H{sub 2}O binary solution. Based upon these conclusions, the recommendation was made to proceed to Phase II, the laboratory breadboard proof-of- concept.

  9. Advanced insulations for refrigerator/freezers: The potential for new shell designs incorporating polymer barrier construction

    SciTech Connect (OSTI)

    Griffith, B.T.; Arasteh, D.

    1992-11-01

    The impending phase-out of chlorofluorocarbons (CFCs) used to expand foam insulation, combined with requirements for increased energy efficiency, make the use of non-CFC-based high performance insulation technologies increasingly attractive. The majority of current efforts are directed at using advanced insulations in the form of thin, flat low-conductivity gas-filled or evacuated orthogonal panels, which we refer to as Advanced Insulation Panels (AIPs). AIPs can be used in composite with blown polymer foams to improve insulation performance in refrigerator/freezers (R/Fs) of conventional design and manufacture. This AIP/foam composite approach is appealing because it appears to be a feasible, near-term method for incorporating advanced insulations into R/Fs without substantial redesign or retooling. However, the requirements for adequate flow of foam during the foam-in-place operation impose limitations on the allowable thickness and coverage area of AIPs. This report examines design alternatives which may offer a greater increase in overall thermal resistance than is possible with the use of AIP/foam composites in current R/F design. These design alternatives generally involve a basic redesign of the R/F taking into account the unique requirements of advanced insulations and the importance of minimizing thermal bridging with high thermal resistance insulations. The focus here is on R/F doors because they are relatively simple and independent R/F components and are therefore good candidates for development of alterative designs. R/F doors have significant thermal bridging problems due to the steel outer shell construction. A three dimensional finite difference computer modeling exercise of a R/F door geometry was used to compare the overall levels of thermal resistance (R-value) for various design configurations.

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

    E-Print Network [OSTI]

    Bahrami, Majid

    /min 2) the compressor power input, in kW 3) the rate of heat transfer from the refrigerant passing through the condenser, in kW. Condenser Evaporator 1 Evaporator 2 Expansion valve Expansion valve Expansion valve Compressor Qin, 2 = 2 tons Qin, 1 = 3 tons 5 6 1 87 4 3 2 Qout Win #12;

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

    E-Print Network [OSTI]

    Bahrami, Majid

    /min 2) the compressor power input, in kW 3) the rate of heat transfer from the refrigerant passing through the condenser, in kW. Condenser Evaporator 1 Evaporator 2 Expansion valve Expansion valve Expansion valve Compressor Qin, 2 = 2 tons Qin, 1 = 3 tons 5 6 1 87 4 3 2 Qout Win #12;M. Bahrami ENSC 461

  12. Storage of Dressed Chinook Salmon, Oncorhynchus tshawytscha, in Refrigerated Freshwater, Diluted Seawater, Seawater, and in Ice

    E-Print Network [OSTI]

    Storage of Dressed Chinook Salmon, Oncorhynchus tshawytscha, in Refrigerated Freshwater, Diluted during storage. Iced storage offers several advantages over the water chilling systems, including little by 25 per- cent within four days after transfer to ice, and weight gained during water storage was lost

  13. FIELD TEST OF A HIGH-EFFICIENCY, AUTOMATIC-DEFROST REFRIGERATOR-FREEZER

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;FIELD TEST OF A HIGH-EFFICIENCY, AUTOMATIC- DEFROST REFRIGERATOR-FREEZER By Richard F. Topping and manufacture pre-production units for home usage tests. The purpose of the field test and the associated market been promising. The first five months of field test data have shown an average 57% decrease in energy

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

    E-Print Network [OSTI]

    Burke, Peter

    with USDA seal, unopened 2 weeks Don't freeze well Raw Hamburger, Ground & Stew Meat Hamburger & stew meats just before using. · If freezing meat and poultry in its original package longer than 2 monthsProduct Refrigerator Freezer Eggs Fresh, in shell 4 to 5 weeks Don't freeze Raw yolks, whites 2

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

    E-Print Network [OSTI]

    Bahrami, Majid

    in refrigeration and heat pump systems, HVAC, porous media development/characterization, transport phenomena of compact and lightweight heat exchangers for evaporator and condenser; v) Development of heatdriven storage for service vehicles; vii) Development of sustainable hybrid A/C systems featuring desiccant

  16. Compatibility of lubricant additives with HFC refrigerants and synthetic lubricants. Final report, Part 1

    SciTech Connect (OSTI)

    Cavestri, R.C.

    1997-07-01

    Part one of this research provides manufacturers of components of air-conditioning and refrigeration equipment with a useful list of lubricant additives, sources, functional properties and chemical species. The list in part one is comprised of domestic lubricant additive suppliers and the results of a literature search that was specifically targeted for additives reported to be useful in polyolester chemistry.

  17. Steady-state operational degrees of freedom with application to refrigeration cycles

    E-Print Network [OSTI]

    Skogestad, Sigurd

    - position of the circulating refrigerant are also discussed. Two LNG processes of current interest, the C3MRTM LNG process from Air Products and the MFCTM process developed by Statoil-Linde LNG Technology. The optimal design of LNG processes has been studied extensively by several com- panies such as Air Products

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

    SciTech Connect (OSTI)

    Lekov, Alex; Thompson, Lisa; McKane, Aimee; Rockoff, Alexandra; Piette, Mary Ann

    2009-05-11

    This report summarizes the Lawrence Berkeley National Laboratory's research to date in characterizing energy efficiency and open automated demand response opportunities for industrial refrigerated warehouses in California. The report describes refrigerated warehouses characteristics, energy use and demand, and control systems. It also discusses energy efficiency and open automated demand response opportunities and provides analysis results from three demand response studies. In addition, several energy efficiency, load management, and demand response case studies are provided for refrigerated warehouses. This study shows that refrigerated warehouses can be excellent candidates for open automated demand response and that facilities which have implemented energy efficiency measures and have centralized control systems are well-suited to shift or shed electrical loads in response to financial incentives, utility bill savings, and/or opportunities to enhance reliability of service. Control technologies installed for energy efficiency and load management purposes can often be adapted for open automated demand response (OpenADR) at little additional cost. These improved controls may prepare facilities to be more receptive to OpenADR due to both increased confidence in the opportunities for controlling energy cost/use and access to the real-time data.

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

    E-Print Network [OSTI]

    heating in freezers, evaporator fan controls, compressor part load efficiency in specific applications than 3,000 ft² in floor area. Additionally, areas within refrigerated warehouses designed solely Btu/hr-ft² of floor space, which is equivalent to 2 tons per 100ft² of floor space, at conditions

  20. 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-off between energy consumption and food quality loss, at varying ambient con- ditions, in supermarket for energy savings without extra loss of food quality is demonstrated. We also show that by utilizing