WorldWideScience

Sample records for refrigerated display cabinet

  1. Refrigerated display cabinets; Butikskyla

    Energy Technology Data Exchange (ETDEWEB)

    Fahlen, Per

    2000-07-01

    This report summarizes experience from SP research and assignments regarding refrigerated transport and storage of food, mainly in the retail sector. It presents the fundamentals of heat and mass transfer in display cabinets with special focus on indirect systems and secondary refrigerants. Moreover, the report includes a brief account of basic food hygiene and the related regulations. The material has been compiled for educational purposes in the Masters program at Chalmers Technical University.

  2. Performance simulation of refrigerated display cabinets operating with refrigerants R22 and R404A

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Y.T. [Mechanical Engineering, School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH (United Kingdom); Cropper, R. [Formerly School of Engineering, North East Wales Institute, Plas Coch Campus, Mold Road, Wrexham L11 2AW (United Kingdom)

    2008-08-15

    This paper describes the analysis and performance comparison of a display cabinet system using refrigerant R404A and its substitute refrigerant R22. The model of the display cabinet is developed at steady state and integrated from three main component sub-models, air-cooling finned-tube evaporator, air curtain and display cabinet body. The evaporator model is built up based on the distributed method, which can simulate the heat exchangers with different circuit structures. The frost effect on the performance of the evaporator is included in the model. The correlations for the heat transfer and pressure drop calculations of both air and refrigerant sides are purposely selected in the evaporator model. In addition, the evaporator model has been validated with experimental results at steady states from published literature. Several correlated functions from the detailed numerical solution are used for the model of the air curtain. Some simplifications are also utilized for the model of display cabinet body. The performance simulation and comparison of the display cabinet using refrigerants R404A and R22 are carried out at different indoor ambient conditions especially at varied ambient air humidity to mimic the actual indoor space conditions in super stores. Some significant results such as the comparison of cooling load requirement for different refrigerant display cases have been obtained from the simulation, which can significantly contribute to the optimal cabinet design and operating analysis. (author)

  3. Quality Model of Foodstuff in a Refrigerated Display Cabinet

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    Commercial refrigerating systems need to be defrosted regularly to maintain a satisfactory performance. When defrosting the evaporator coil, the air temperature inside the display cabinet will increase, and float outside the normal temperature range for a period of time, the question is what...... happens to the food inside during this period, when we look at the quality factor? This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as how the defrost temperature and duration influence the food temperature, thus the food quality, as well...

  4. Detailed CFD Modelling of Open Refrigerated Display Cabinets

    Directory of Open Access Journals (Sweden)

    Pedro Dinis Gaspar

    2012-01-01

    Full Text Available A comprehensive and detailed computational fluid dynamics (CFDs modelling of air flow and heat transfer in an open refrigerated display cabinet (ORDC is performed in this study. The physical-mathematical model considers the flow through the internal ducts, across fans and evaporator, and includes the thermal response of food products. The air humidity effect and thermal radiation heat transfer between surfaces are taken into account. Experimental tests were performed to characterize the phenomena near physical extremities and to validate the numerical predictions of air temperature, relative humidity, and velocity. Numerical and experimental results comparison reveals the predictive capabilities of the computational model for the optimized conception and development of this type of equipments. Numerical predictions are used to propose geometrical and functional parametric studies that improve thermal performance of the ORDC and consequently food safety.

  5. CFD Parametric Studies for Global Performance Improvement of Open Refrigerated Display Cabinets

    Directory of Open Access Journals (Sweden)

    Pedro Dinis Gaspar

    2012-01-01

    Full Text Available A detailed CFD modelling of an open refrigerated display cabinet has been formulated in a previous study. Some modifications are introduced in order to perform parametric studies dealing with low-cost geometrical and functional characteristics for improvement of the global performance and energy efficiency. The parametric studies are devoted to the analysis of the thermal response and behaviour inside the food conservation space influenced by (1 air flow rate through the evaporator heat exchanger; (2 air curtain behaviour; (3 hole dimensions and distribution of the back panel; (4 discharge and return grilles angles; and (5 flow deflectors inside the internal duct. The analysis of the numerical predictions from the parametric studies allows the development of an optimized model for the conception of an open refrigerated display cabinet with a more adequate configuration. The numerical predictions of the optimized model show lower product temperature and reduced electrical energy consumption, allowing the improvement of the food safety and the energy rationalization of the refrigeration equipment.

  6. Numerical and experimental investigations on the use of mist flow process in refrigerated display cabinets

    Energy Technology Data Exchange (ETDEWEB)

    Moureh, J.; Letang, G.; Palvadeau, B. [UMR Genie Industriel Alimentaire Cemagref-ENSIA-INAPG-INRA, Cemagref Antony Refrigerating Process Engineering Unit, Parc de Tourvoie, BP 44, 92163 Antony cedex (France); Boisson, H. [IMFT Institut de Mecanique des Fluides de Toulouse, Av. du Professeur Camille Soula, 31400 Toulouse (France)

    2009-03-15

    This study concerns the use of mist flow whereby fine water droplets are injected into the air curtain to improve the performance of Refrigerated Display Cabinets (RDCs). The deposition and evaporation of droplets on the surface of products partially compensate the radiative heat gained by the products by removing from it the amount of latent heat of the evaporated droplets. The experiments were carried out on an actual display cabinet. Numerical modelling was performed using Fluent Computational Fluid Dynamics (CFD) software. In two-phase flow, an Euler-Lagrange approach was adopted to predict the transport of droplets by the air curtain and their spatial distribution on the product surface of the RDC. An original numerical procedure was built in the CFD model in order to compute the deposited droplets while taking into account the evaporative flux of droplets on the product surface. The two-phase flow model was used to analyse the performance of the mist cooling process in terms of surface temperature decrease and the homogeneity of droplet deposition on the product surface of the RDC as a function of inlet droplet injection configurations. (author)

  7. Numerical Simulation on the Food Package Temperature in Refrigerated Display Cabinet Influenced by Indoor Environment

    Directory of Open Access Journals (Sweden)

    Chang Zhijuan

    2013-01-01

    Full Text Available In order to study the relation between the food package temperature and ambient environment, the food package temperature is investigated by numerical simulation under the different conditions, such as evaporator outlet velocities, ambient temperatures, and relative humidity. In the present computation, the influence of mass transfer and radiation is considered. The computational results show that the front and top food package temperature rises to 0.1 ~ 1.2°C due to the effect of light. At the investigated range of this paper, the food package temperature decreases when the air curtain velocity increases, but the food package temperature also increases with increase of ambient temperature and humidity. At the same time, the food package temperature decreases 0.2 ~ 1.1°C when air curtain outlet velocity increased by 0.15 m/s. The food package temperature rises about 0.6°C when ambient temperature increases by 2°C. The food package temperature rises about 0.9°C when ambient humidity increases by 20%. Therefore, the study can provide the reference for the design of refrigerated display cabinet.

  8. Energy efficiency categories for refrigerated display cabinets in food retailer shops; Effizienzklassen fuer Kuehlmoebel im Detailhandel. Vorstudie

    Energy Technology Data Exchange (ETDEWEB)

    Froelich, A.

    2004-07-01

    Up to now, in the European Union, an efficiency declaration is compulsory for household refrigerators but not for refrigerated display cabinets (RDC). This study deals with the possibilities for an improvement of the efficiency of such cabinets for the Swiss market. There are different voluntary actions in Europe aiming to improve the efficiency of RDCs. First of all, the Netherlands started end of the 90ties to pay subsidies to promote efficient cabinets. The procedures for the measurement and the classification where developed by TNO, the Dutch Testing and Research Organisation. The European Association of Air Handling and Refrigerating Equipment Manufacturers, Eurovent/Cecomaf, is building up a database with the efficiency data of all RDCs. It uses the procedures developed by TNO. According to the schedule for the test and certification procedure the database will be complete in 2009 only. By October 2004 Australia and New Zealand have introduced a new law, which sets strict standards for the installation of new RDCs. The procedures applied are similar to those of TNO and Eurovent. The European Standard for the declaration of RDCs is the EN 441, developed in 1995. A new Standard, the prEN 23953, has been worked out. It is for final vote now and will come into force in 2005. The basics content of EN 441 was kept, but new procedures like the one applicable to the testing of cabinets with remote condensing units where integrated. For Switzerland, it is suggested to develop a strategy for improving the efficiency of RDCs. The best way would be the introduction of an efficiency label. For this goal, the help of the 'key players' in Europe would be necessary. If this does not work out, it should be considered to adapt the measures or programs which were introduced in the Netherlands or in Australia and New Zealand. (author)

  9. Detecting Fan Faults in refrigerated Cabinets

    DEFF Research Database (Denmark)

    Thybo, C.; Rasmussen, B.D.; Izadi-Zamanabadi, Roozbeh

    2002-01-01

    Fault detection in supermarket refrigeration systems is an important topic due to both economic and food safety reasons. If faults can be detected and diagnosed before the system drifts outside the specified operational envelope, service costs can be reduced and in extreme cases the costly...... faults in display cabinets under the wide operational conditions that display cabinets are exposed to. The approach described uses a non- linear parity equation comparing the heat transfer rates of the air and the refrigerant. The paper presents the detection method and discusses the application...

  10. Quality Model of Foodstuff in the Control of Refrigerated Display Cabinet

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    as what is the optimal defrost scheme from food quality point of view are answered. This will serve as a prerequisite of designing of optimal control scheme for the commercial refrigeration system, aiming at optimizing a weighed cost function of both food quality and overall energy consumption of system....... happens to the food inside during this period, when we look at the quality factor? This paper discusses quality model of foodstuff, different scenarios of defrost scheme are simulated, questions such as how the defrost temperature and duration influence the food temperature, thus the food quality, as well...

  11. Laminar-flow Liquid-to-air Heat Exchangers - Energy-efficient Display Cabinet Applications

    OpenAIRE

    Haglund Stignor, Caroline

    2009-01-01

    Provisions are stored and displayed in supermarkets and grocery stores, at a temperature lower than the ambient, in display cabinets, which are responsible for a significant amount of the energy use in this sector. During the 1990s, major changes in the regulations governing the use of synthetic refrigerants took place in Sweden. This resulted in many refrigeration systems being converted to systems with indirect cooling by means of a liquid secondary refrigerant. The cooling coil is an impor...

  12. Additive Manufacturing of Tooling for Refrigeration Cabinet Foaming Processes

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K [ORNL; Nuttall, David [ORNL; Cukier, Michael Z [ORNL; Hile, Michael B [ORNL

    2016-07-29

    The primary objective of this project was to leverage the Big Area Additive Manufacturing (BAAM) process and materials into a long term, quick change tooling concept to drastically reduce product lead and development timelines and costs. Current refrigeration foam molds are complicated to manufacture involving casting several aluminum parts in an approximate shape, machining components of the molds and post fitting and shimming of the parts in an articulated fixture. The total process timeline can take over 6 months. The foaming process is slower than required for production, therefore multiple fixtures, 10 to 27, are required per refrigerator model. Molds are particular to a specific product configuration making mixed model assembly challenging for sequencing, mold changes or auto changeover features. The initial goal was to create a tool leveraging the ORNL materials and additive process to build a tool in 4 to 6 weeks or less. A secondary goal was to create common fixture cores and provide lightweight fixture sections that could be revised in a very short time to increase equipment flexibility reduce lead times, lower the barriers to first production trials, and reduce tooling costs.

  13. Open-refrigerated retail display case temperature profile and its impact on product quality and microbiota of stored baby spinach

    Science.gov (United States)

    Open-refrigerated display cabinets are widely used in supermarkets and grocery chains around the globe. However, the temperature conditions in these display cases are variable which may impact product quality and safety. Therefore, we investigated the quality and microbiological populations of bagge...

  14. Vibroacoustic Analysis of a Refrigerator Freezer Cabinet Coupled with an Air Duct

    Directory of Open Access Journals (Sweden)

    Onur Çelikkan

    2017-01-01

    Full Text Available In this study, the vibration and acoustic interactions between the structure and the cavity inside the freezer cabinet were investigated. Thus, a set of numerical and experimental analyses were performed. In the numerical analysis, the acoustic characteristics of the freezer cavity were solved, and the mixed finite element method was then implemented to analyse the coupled behaviour of the cavity with the air duct using the Acoustic Fluid-Structure Interaction (AFSI technique. In the experimental analyses, an acoustic modal analysis of the freezer cavity and a structural modal analysis of the air duct were performed for the validation process. A good agreement was obtained among the results. Thus, the accuracy of the numerical model was confirmed. The validated models were used for optimizing the design. To solve the noise generation mechanism inside the freezer cabinet, the noise primarily generated by the freezer fan unit was measured under normal working conditions of the refrigerator, and the resonance frequencies were obtained. This information was compared with the normal modes of the air duct, and the overlapping frequencies were identified. To reduce the interaction between the source and the structure, a few design modifications were applied to the air duct. Thus, the structural-borne noise radiating from the air duct into the freezer cavity was reduced.

  15. 10 CFR 431.64 - Uniform test method for the measurement of energy consumption of commercial refrigerators...

    Science.gov (United States)

    2010-01-01

    ... Institute (ARI) Standard 1200-2006, “Performance Rating of Commercial Refrigerated Display Merchandisers and... Requirements for Self-contained Commercial Refrigerated Display Merchandisers and Storage Cabinets... Remote Commercial Refrigerated Display Merchandisers and Storage Cabinets.” (Incorporated by reference...

  16. Vibroacoustic Analysis of a Refrigerator Freezer Cabinet Coupled with an Air Duct

    OpenAIRE

    Onur Çelikkan; Haluk Erol

    2017-01-01

    In this study, the vibration and acoustic interactions between the structure and the cavity inside the freezer cabinet were investigated. Thus, a set of numerical and experimental analyses were performed. In the numerical analysis, the acoustic characteristics of the freezer cavity were solved, and the mixed finite element method was then implemented to analyse the coupled behaviour of the cavity with the air duct using the Acoustic Fluid-Structure Interaction (AFSI) technique. In the experim...

  17. ESO2 Optimization of Supermarket Refrigeration Systems

    DEFF Research Database (Denmark)

    Petersen, Lars Norbert; Madsen, Henrik; Heerup, Christian

    Supermarket refrigeration systems consists of a number of display cases, cooling cabinets and cold rooms connected to a central compressor pack. This configuration saves energy compared to placing a compressor at each cooling site. The classical control setup of a supermarket refrigeration system...

  18. Utilizing Thermal Mass in Refrigerated Display Cases to Reduce Peak Demand

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL; Kuruganti, Teja [ORNL; Nutaro, James J [ORNL; Fugate, David L [ORNL; Sanyal, Jibonananda [ORNL

    2016-01-01

    The potential to store energy within refrigerated food products presents convenience store and supermarket operators with an opportunity to participate in utility sponsored demand response programs, whereby electricity usage can be shifted or reduced during peak periods. To determine the feasibility of reducing peak demand by shifting the refrigeration load to off-peak times, experimental and analytical analyses were performed. Simulated product, consisting of one-pint containers filled with a 50% ethylene glycol and 50% water solution, were stored in a medium-temperature vertical open refrigerated display case. Product temperature rise as a function of time was determined by turning off the refrigeration to the display case, while product temperature pull-down time was subsequently determined by turning on the refrigeration to the display case. It was found that the thermal mass of the product in a medium-temperature display case was such that during a 2.5 hour period with no refrigeration, the average product temperature increased by 5.5 C. In addition, it took approximately 3.5 hours for the product to recover to its initial temperature after the refrigeration was turned on. Transient heat conduction analyses for one-dimensional objects is in good agreement with the experimental results obtained in this study. From the analysis, it appears that the thermal mass of the stored product in refrigerated display cases is sufficient to allow product temperatures to safely drift for a significant time under reduced refrigeration system operation. Thus, strategies for shifting refrigeration system electrical demand can be developed. The use of an advanced refrigeration system controller that can respond to utility signals can enable demand shifting with minimal impact.

  19. Effects of acoustic hood on noise, CFC-11, and particulate matter in a recycling system for waste refrigerator cabinet.

    Science.gov (United States)

    Guo, Jie; Fang, Wenxiong; Yang, Yichen; Xu, Zhenming

    2014-11-01

    The mechanical-physical process was proven to be technologically feasible for waste refrigerator recycling and has been widely used in the typical e-waste recycling factories in China. In this study, effects of the acoustic hood on the reduction of noise level, CFC-11, and heavy metals (Cr, Ni, Cu, Cd, and Pb) in particulate matter (PM) were evaluated. For noise pollution, the noise level inside and outside the acoustic hood was 96.4 and 78.9 dB, respectively. Meanwhile, it had a significant effect on A-weighted sound level with a reduction from 98.3 to 63.6 dB. For CFC-11 exposure, abundant CFC-11 (255 mg/m(3)) was detected in the acoustic hood. However, the mean concentration of CFC-11 at the outline of polyurethane foam collection was obviously diminished to 14 mg/m(3), and no CFC-11 was monitored around the acoustic hood. The concentrations of PM and heavy metals in PM outside the acoustic hood were lower than those inside the acoustic hood due to the physical barriers of the acoustic hood. Based on the risk assessment, only adverse health effect caused by Pb might likely appear. All the results can provide the basic data for pollution control and risk assessment in waste refrigerator recycling system.

  20. Performance Monitoring in Supermarket Refrigeration Systems - Synchronisation of Refrigerated Display Cases

    DEFF Research Database (Denmark)

    Chen, Liang; Green, Torben; Sloth Larsen, Lars Finn

    2009-01-01

    . The conceptual validation of these methods has been by far illustrated through the use of typically simple academic examples. In this paper the hybrid systems is treated as a single directed topological space, and presents a refrigeration system as a benchmark that should be useful as a platform...

  1. Model Identification for Control of Display Units in Supermarket Refrigeration Systems

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Andersen, Philip Hvidthøft Delff

    In this paper we propose a method for identifying and validating a model of the heat dynamics of a supermarket refrigeration display case for the purpose of advanced control. The model is established to facilitate the development of novel model-based control techniques for individual display units...... in a supermarket refrigeration system. The grey-box modelling approach is adopted, using stochastic differential equations to define the dynamics of the model, combining prior knowledge of the physical system with data-driven modelling. Model identification is performed using the forward selection method......, and the performance of candidate models is evaluated through cross-validation.The model developed in this work uses operational data from a small Danish supermarket. A three-state model is determined to be most appropriate for describing the dynamics of this system. Advanced local control employing the identified...

  2. Food Service Refrigerators and Food Service Storage Freezers. Standard No. 7, Revised April 1966.

    Science.gov (United States)

    National Sanitation Foundation, Ann Arbor, MI.

    This standard covers the sanitation and performance requirements for new food service refrigerators and food service storage freezers of the type generally used in the food service industry. It covers cabinets operating in the freezers, above or below freezing temperature, designed for the storage or display of varieties of food products. Topics…

  3. Minimizing quality deteriorations of refrigerated foodstuffs as a side effect of defrosting

    DEFF Research Database (Denmark)

    Cai, Junping; Stoustrup, Jakob

    2008-01-01

    This paper proposes an optimization scheme for traditional refrigeration systems with hysteresis controllers and scheduled defrosts. It aims at minimizing the side effect of defrost cycles on the storage quality of refrigerated foodstuffs in supermarkets. By utilizing the thermal mass of air...... and products inside a display cabinet, this optimization scheme forces the compressor to work harder and cool down more prior to the scheduled defrosts, thus guaranteeing the product temperature after defrost cycles still to be within a controlled safe level....

  4. 75 FR 29823 - Energy Conservation Program for Consumer Products: Test Procedures for Refrigerators...

    Science.gov (United States)

    2010-05-27

    ...'' means an electric refrigerator-freezer. ``Electric refrigerator'' means a cabinet designed for the... Refrigerators, Refrigerator-Freezers, and Freezers; Proposed Rule #0;#0;Federal Register / Vol. 75, No. 102... Conservation Program for Consumer Products: Test Procedures for Refrigerators, Refrigerator-Freezers, and...

  5. Redesign and Automation of a mold for manufacturing of refrigerated display cases using Polyurethane Foam Injection

    Directory of Open Access Journals (Sweden)

    Eugenio Yime

    2016-10-01

    Full Text Available Context: To stay competitive over time, a company must continually submit their processes to improvements and updates. Herein are proposed some improvements with regard to safety at work and the reduction of time that occurs during the operation of a mold for manufacturing refrigerators. Method: Some operating conditions of the mold are analyzed and then some factors affecting the processing time and the safety of operating personnel are established. The weaknesses found are related to the intrinsic design of the mold, which raises the need for a structural redesign that also includes automation. Results: It is presented a new design and way to operate the mold which reduces the risk of accidents at having no heavy loads over operator heads. Another contribution of the redesign is the increase in the system rigidity which helps to reduce manufacturing defects. Finally, it is show a automation design which helps to reduce manufacturing times. Conclusions: Significant improvements were obtained in the operation of the mold, such as the reduction of occupational hazards and reduced manufacturing time of refrigerators. These improvements translate into benefits for the company, by reducing costs and increasing production. Both benefits help strengthen the competitiveness of the company.

  6. Terrorism and cabinet duration

    NARCIS (Netherlands)

    Gassebner, M.; Jong-A-Pin, R.; Mierau, J.O.

    2011-01-01

    Terrorism can strengthen or weaken electoral support for ruling governments. We show in a simple model of coalition formation that, regardless of the direction of a public opinion shock, the impact of terrorism on cabinet duration is ambiguous. However, in an analysis of a data set including 2,400

  7. Manufacturing A Refrigerator with Heat Recovery Unit

    Directory of Open Access Journals (Sweden)

    Mustafa Mohammed Kadhim

    2018-02-01

    Full Text Available This study aims to exploite the rejected heating energy from condenser and benefit from it to reheat the foods and other materials. It can also be employed to improve the coefficient of performance of a refrigerator at the same time by using approximately the same consumption electrical energy used to operate the compressor and refrigerator in general. This idea has been implemented by manufacturing of a refrigerator with using additional part has the same metal and condenser pipe diameters but its surface area does not exceed 40% from total surface area of the condenser and its design as an insulated cabinet from all sides to prevent heat leakage through it and located between the compressor and the condenser. Small electrical fan has been added inside this cabinet to provide a suitable air circulation and a homogenous temperature distribution inside the cabinet space. It is expected that the super heating energy of refrigerant (R134a which comes out of the compressor would be removed  inside this cabinet and this insist to condensate the refrigerant (cooling fluid with a rate higher than that used in the normal refrigerator only. Three magnetic valves have been used in order to control the refrigerant flow in state of operation the refrigerator only or to gather with heating cabinet. To measure the temperatures at each process of the simple vapor compression refrigeration cycle, nine temperature sensors at input and output of each compressor, condenser and an evaporator in additional to input of cabinet and inside it and on evaporator surface have been provided. Five pressure gages have been used to measure the value of pressure and compare it for the two states of operation. The consumption of electrical energy  can be calculated by adding an ammeter and a voltmeter and compare between the consumption energy of both states. The obtained results show that there is an improvement in the coeffecient of performance in state of operation the

  8. 75 FR 78809 - Energy Conservation Program for Consumer Products: Test Procedures for Refrigerators...

    Science.gov (United States)

    2010-12-16

    ... currently define a freezer as ``a cabinet designed as a unit for the freezing and storage of food at... Refrigerators, Refrigerator-Freezers, and Freezers; Final Rule and Interim Final Rule #0;#0;Federal Register... Refrigerators, Refrigerator-Freezers, and Freezers AGENCY: Office of Energy Efficiency and Renewable Energy...

  9. Development of a high efficiency, automatic defrosting refrigerator-freezer

    Science.gov (United States)

    Topping, R. F.; Lee, W. D.

    The development of an energy efficient refrigerator freezer prototype to accelerate the commercialization of residential, high efficiency refrigerator freezers is described. A computer model developed to simulate the cabinet and refrigeration unit performance was used to evaluate alternative designs and optimize the cabinet insulation as well as the refrigeration component integration. Placement of polyurethane foam insulation in the cabinet and thicker insulation in the doors were used to reduce the closed door heat load of the prototype. Modifications to the evaporator system provide automatic frost-free operation with a significantly reduced defrost energy requirement. Resulting higher moisture levels in the refrigerator compartment enhance fresh food storage. A dual control system, different from most models which use only one active control, provides precise temperature regulation in both the freezer and refrigerator compartments.

  10. Load forecasting for supermarket refrigeration

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Aalborg Nielsen, Henrik

    This report presents a study of models for forecasting the load for supermarket refrigeration. The data used for building the forecasting models consists of load measurements, local climate measurements and weather forecasts. The load measurements are from a supermarket located in a village...... in Denmark. The load for refrigeration is the sum of all cabinets in the supermarket, both low and medium temperature cabinets, and spans a period of one year. As input to the forecasting models the ambient temperature observed near the supermarket together with weather forecasts are used. Every hour...... the hourly load for refrigeration for the following 42 hours is forecasted. The forecast models are adaptive linear time-series models which are fitted with a computationally efficient recursive least squares scheme. The dynamic relations between the inputs and the load is modeled by simple transfer...

  11. 77 FR 17410 - Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea: Final Affirmative...

    Science.gov (United States)

    2012-03-26

    ... combination refrigerator-freezers, namely: (1) Any assembled cabinets designed for use in bottom mount... external doors designed for use in bottom mount combination refrigerator-freezers that incorporate, at a... assembled external drawers designed for use in bottom mount combination refrigerator-freezers that...

  12. 76 FR 55044 - Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea: Preliminary Negative...

    Science.gov (United States)

    2011-09-06

    ..., namely: (1) Any assembled cabinets designed for use in bottom mount combination refrigerator-freezers... designed for use in bottom mount combination refrigerator-freezers that incorporate, at a minimum: (a) an... International Trade Administration Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea...

  13. 76 FR 23298 - Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea: Initiation of...

    Science.gov (United States)

    2011-04-26

    ... in bottom mount combination refrigerator-freezers, namely: (1) Any assembled cabinets designed for...; (2) any assembled external doors designed for use in bottom mount combination refrigerator-freezers... International Trade Administration Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea...

  14. Displays

    OpenAIRE

    Schauer, A.

    1983-01-01

    A short review is given on new display technologies such as plasma, liquid crystals, light emitting diodes, electroluminescence and electrochromism. It is stated that thin or thick film or hybrid techniques are essential for all the different types of display. Comparing the performance data of displays the advantages, disadvantages, appropriate applications and future developments are described. Finally the display market and its growth are discussed briefly.

  15. Hydrophilic structures for condensation management in refrigerator appliances

    Science.gov (United States)

    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.

  16. Oxidative stability and its relationship with natural antioxidants during refrigerated retail display of beef produced in Argentina.

    Science.gov (United States)

    Insani, E M; Eyherabide, A; Grigioni, G; Sancho, A M; Pensel, N A; Descalzo, A M

    2008-07-01

    The objective of this study was to determine if pasture or grain diets affect oxidative/antioxidative status and the color stability of beef during retail display. Ten crossbreed steers were fed on pasture. Five of them were randomly assigned to remain on this diet, and the other five were finished on feedlot system (grain diet) during 110days until slaughter. Slices of Psoas major steaks were randomly distributed among retail display times (1, 3, 5, 7 and 9days). Lipid and protein oxidation were higher in Psoas major steaks from grain diet than in pasture diet (P<0.05). After 3days of display, lipid oxidation increased in meat from grain diet, whereas in meat from pasture diet the first evidence was after 7days (P<0.05). Protein oxidation was higher in meat from grain diet than in meat from pasture diet at day 9 of display (1.15±0.92 vs. 1.91±0.70μg/g, respectively; P<0.05). Antioxidant vitamins, α-tocopherol and β-carotene were higher at time=0 in pasture Psoas major steaks (P<0.05) and were differentially reduced throughout storage. While α-tocopherol decreased 41% and 57% for pasture and grain beef respectively (P<0.05), β-carotene levels remained practically unaffected in grain beef. After 7days of display "a" value was higher for Psoas major steaks from pasture diet (P<0.05). Besides, "L" parameter showed higher values for samples from grain diets but it was no affected by display time. No differences were observed between both treatments for "b" value, but a significant decrease (P<0.05) was observed along storage. Superoxide dismutase and catalase activity was stable throughout storage, while glutathione peroxidase activity decreased significantly (P<0.05). The results in this study demonstrated that the higher initial level and synergistic action (under light and air) of α-tocopherol and β-carotene found in pasture-finished animals improved the oxidative and color stability of beef, as showed by a better retention of redness at the end of retail

  17. 76 FR 72440 - Bottom Mount Combination Refrigerator-Freezers From Korea and Mexico; Scheduling of the Final...

    Science.gov (United States)

    2011-11-23

    ... mount combination refrigerator-freezers, namely: (1) Any assembled cabinets designed for use in bottom... assembled external doors designed for use in bottom mount combination refrigerator-freezers that incorporate...) any assembled external drawers designed for use in bottom mount combination refrigerator-freezers that...

  18. State Children's Cabinets and Councils: 2008 Directory

    Science.gov (United States)

    Gaines, Elizabeth; Ravindranath, Nalini; Folliard, June

    2008-01-01

    This paper serves as the introduction to the State Children's Cabinets and Councils Series, a set of reports intended to capture and organize the decisions and experiences of more than 20 children's cabinets and councils and present them against an emerging set of expectations about what the public and policy makers could and should expect from…

  19. Russia's science minister keeps cabinet post

    CERN Multimedia

    1999-01-01

    Mikhail Kirpichnikov, minister for science and technology has kept his post in the cabinet of the new prime minister Sergei Stepashin. Yevgeniy Adamov also remains as minister of atomic energy (2 paragraphs).

  20. Thermoacoustic refrigeration

    Science.gov (United States)

    Garrett, Steven L.; Hofler, Thomas J.

    1991-12-01

    A new refrigerator which uses resonant high amplitude sound in inert gases to pump heat is described and demonstrated. The phasing of the thermoacoustic cycle is provided by thermal conduction. This 'natural' phasing allows the entire refrigerator to operate with only one moving part (the loudspeaker diaphragm). The thermoacoustic refrigerator has no sliding seals, requires no lubrication, uses only low-tolerance machine parts, and contains no expensive components. Because the compressor moving mass is typically small and the oscillation frequency is high, the small amount of vibration is very easily isolated. This low vibration and lack of sliding seals makes thermoacoustic refrigeration an excellent candidate for food refrigeration and commercial/residential air conditioning applications. The design, fabrication, and performance of the first practical, autonomous thermoacoustic refrigerator, which will be flown on the Space Shuttle (STS-42), are described, and designs for terrestrial applications are presented.

  1. Advanced exergy analysis of a R744 booster refrigeration system with parallel compression

    DEFF Research Database (Denmark)

    Gullo, Paride; Elmegaard, Brian; Cortella, Giovanni

    2016-01-01

    In this paper, the advanced exergy analysis was applied to a R744 booster refrigeration system with parallel compression taking into account the design external temperatures of 25 degrees C and 35 degrees C, as well as the operating conditions of a conventional European supermarket. The global...... stage) compressor and the MT (medium temperature) display cabinet exhibited the highest enhancement potential. The further splitting of their corresponding exergy destruction rates into their different parts and the following assessment of the interactions among the components allowed figuring out...... the real achievable improvements. The avoidable irreversibilities of the HS compressor and that of the MT evaporator were mainly and completely endogenous, respectively. On the other hand, the gas cooler/condenser could be predominantly improved by decreasing the inefficiencies of the MT evaporator...

  2. Flammable refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Gerwen, R.J.M. van; Verwoerd, M.; Oostendorp, P.A. [Netherlands Organization for Applied Scientific Research TNO, Apeldoorn (Netherlands). Dept. of Refrigeration and Heat Pump Technology

    1999-07-01

    Hydrocarbons are promising alternatives for CFC, HCFC and HFC refrigerants. Due to their flammable nature, safety aspects have to be considered carefully. The world-wide situation concerning acceptability and practical application of flammable refrigerants is becoming more and more complex and confusing. Quantification of the risks of using flammable refrigerants in specific applications is the only way to make the situation clear and to discuss this topic on the basis of facts and figures. Several Quantitative Risk Assessments (QRA) have been carried out by TNO, resulting in risk figures to be compared with generally accepted risk criteria. In addition, risk reducing measures may be evaluated by using the same kind of QRA's. The example QRA's carried out for the cooling system of a bulk milk tank and for a residential heat pump, show acceptable risk levels, as long as the proper safety measures are applied. Other QRA's for several applications (domestic refrigerators, air dehumidifiers, automotive air-conditioning etc.) containing up to a few kilograms of hydrocarbon refrigerant confirm these results. Several national, European and international (draft) standards and guidelines are available, almost always being inconsistent or conflicting. Most of them are based on refrigeration expertise and experience, and not on a quantification of the risks. A Working Group of CEN/TC 182 currently identifies and quantifies the risks of flammable refrigerants, creating a solid basis for a revision of the European safety standard for refrigerating systems and heat pumps. (orig.)

  3. Validation of cross-contamination control in biological safety cabinet for biotech/pharmaceutical manufacturing process.

    Science.gov (United States)

    Hu, Shih-Cheng; Shiue, Angus; Tu, Jin-Xin; Liu, Han-Yang; Chiu, Rong-Ben

    2015-12-01

    For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet exhaust opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC.

  4. 21 CFR 890.5250 - Moist steam cabinet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Moist steam cabinet. 890.5250 Section 890.5250...) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Therapeutic Devices § 890.5250 Moist steam cabinet. (a) Identification. A moist steam cabinet is a device intended for medical purposes that delivers...

  5. Modeling structural acoustic properties of loudspeaker cabinets

    DEFF Research Database (Denmark)

    Luan, Yu

    In this dissertation, a theoretical/numerical methodology is presented for coarse and fast predictions of cabinet vibrations. The study is focused on vibrations of rib-stiffened panels by improving a smearing technique and employing it into finite element modeling. The computationally efficient s...

  6. Manufacture of oak furniture, cabinets, and panels

    Science.gov (United States)

    Harold C. Moser

    1971-01-01

    Oak is uniquely favored for use in furniture, cabinets, and similar products. The supply is plentiful. Though drying presents some problems, once oak is properly dried it is a stable wood that machines very well, glues well, and accepts a variety of finishes well.

  7. Dynamic Heat Transfer Model of Refrigerated Foodstuff

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    their temperature relation. This paper discusses the dynamic heat transfer model of foodstuff inside the display cabinet, one-dimensional dynamic model is developed, and the Explicit Finite Difference Method is applied, to handle the unsteady heat transfer problem with phase change, as well as time varying boundary...

  8. Indirect refrigeration systems with natural refrigerants

    DEFF Research Database (Denmark)

    Knudsen, Hans Jørgen Høgaard; Christensen, Kim Gardø; Jensen, Per Henrik

    1998-01-01

    Heat transfer for boiling and condensing carbon dioxide has been investigated.Heat transfer for carbon dioxide evaporating inside pipe has been measured and compared with Shah's correlation. The measured heat transfer coefficient is much higher than the value determined with the correlation.A she......-and-tube heat exchanger with carbon dioxide on the shell side and flow ice inside the tubes has been used to investigate the heat transfer for condensing carbon dioxide.At leats is mentioned results obtained with a frozen food display case using carbone dioxide as refrigerant....

  9. Density Gradient Columns for Chemical Displays.

    Science.gov (United States)

    Guenther, William B.

    1986-01-01

    Procedures for preparing density gradient columns for chemical displays are presented. They include displays illustrating acid-base reactions, metal ion equilibria, and liquid density. The lifetime of these metastable displays is surprising, some lasting for months in display cabinets. (JN)

  10. Three interactive scenes of The Crystal Cabinet

    OpenAIRE

    Unander-Scharin, Åsa

    2010-01-01

    The interactive scenes of The Crystal Cabinet (2008) constitute the first part in my choreographic research project exploring volatile bodies and multistable corporealities. This performance took the form of a dream play opera in twelve scenes including texts and images from William Blake’s (1757-1827) illuminated books. To create his books Blake invented a printing-machine with which he could print his handwritten poems and images. We transformed this idea into an interactive stage area wher...

  11. Defrost Temperature Termination in Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  12. [BETWEEN HORROR AND SCIENCE: THE BIRTH OF A CABINET OF PATHOLOGICAL ANATHOMY AT THE UNIVERSITY OF PALERMO].

    Science.gov (United States)

    Craxí, Lucia; Maresi, Emiliano; Franco, Vito

    2014-01-01

    This paper outlines the history of the Cabinet of Pathological Anathomy at the University of Palermo, describes rapidly its current status and analyzes the composition of its displays in 1859. It aims to highlight the analogies with other collections of a similar kind and to pinpoint potential actions to endorse and develop this important scientific asset.

  13. The Plus Oultra writing cabinet of Charles V: Expression of the sacred imperialism of the Austrias

    Directory of Open Access Journals (Sweden)

    Ángeles Jordano

    2012-02-01

    Full Text Available The “Plus Oultra” writing cabinet of Charles V on display at the Victoria and Albert Museum of London is an 'intarsia' piece made by Italian craftsmen ca. 1532. This article examines the iconographic programme of the cabinet as an expression of the universal Christian empire of Charles V and the sacred imperialism of the Spanish Austrias. This programme is revealed in three scenes depicting the story of Gideon that decorate the outside of the cabinet fall front: the revelation of the angel to Gideon and the woollen fleece in allusion to the Order of the Golden Fleece of which Charles V was the grand master, the selection of the three hundred men, and the battle against the Midianites. These scenes are complemented by medallion heads of Roman emperors to portray Charles V as legitimate successor to the Ancient Roman Empire. The inside of the fall front is emblazoned with the emblems of Charles V: the Pillars of Hercules, the ‘Plus Ultra’ motto, Saint Andrew’s crosses and laurel motifs, while the allegorical figures of Temperance and Justice adorning the sides of the cabinet symbolise the virtues of a good governor. The fall front opens to reveal a set of drawers and doors decorated with one of the earliest examples of the 'vanitas': objects alluding to the fleeting nature of life and the pursuit of wisdom. From a stylistic standpoint, the scenes and decorative motifs of the cabinet suggest that it may have been made in the workshop of the Dominican friar Damiano da Bergamo which Charles V visited in 1529.

  14. Refrigeration and Food Safety

    Science.gov (United States)

    ... Forms Standard Forms FSIS United States Department of Agriculture Food Safety and Inspection Service About FSIS District ... 286) Actions ${title} Loading... Refrigeration and Food Safety History of Refrigeration Importance of Refrigeration Types of Bacteria ...

  15. The Proteus Cabinet, or "We Are Here but Not Here"

    Science.gov (United States)

    Nield, Sophie

    2008-01-01

    In the early nineteenth century, there were three stage illusions in which a magician could cause a person to disappear. In one of these, the Proteus Cabinet, participants would enter a box, and simply vanish. As the designers of the Proteus Cabinet said of them, they were "Here, but not Here." My essay explores this concept in relation to…

  16. 21 CFR 880.6100 - Ethylene oxide gas aerator cabinet.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ethylene oxide gas aerator cabinet. 880.6100... Miscellaneous Devices § 880.6100 Ethylene oxide gas aerator cabinet. (a) Identification. An ethyene oxide gas... required to remove residual ethylene oxide (ETO) from wrapped medical devices that have undergone ETO...

  17. Thermoeconomic model of a commercial transcritical booster refrigeration system

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Elmegaard, Brian

    2011-01-01

    . The booster refrigeration plant consists of one refrigerant cycle supplying refrigerant for evaporators in both cooled and frozen display cases. The detailed numerical model of a refrigeration plant reflects that the trans- and subcritical operation criteria depends on heat rejection performance defined...... by ambient conditions. As two evaporation temperatures are produced from one exergy stream, thermoeconomic theory is used to establish the price of cooling at each individual temperature level based on operating costs. The analysis shows that exergy for cooling frozen displays has approximately double cost......For cooling applications in supermarkets, booster refrigeration systems operating in both transcritical and subcritical conditions are increasingly used. A thermodynamic model of a transcritical booster refrigeration plant is tailored to match the new generation of commercial refrigeration plants...

  18. Development of a Battery-Free Solar Refrigerator

    Science.gov (United States)

    Ewert, Michael K.; Bergeron, David J., III

    2000-01-01

    Recent technology developments and a systems engineering design approach have led to the development of a practical battery-free solar refrigerator as a spin-off of NASA's aerospace refrigeration research. Off-grid refrigeration is a good application of solar photovoltaic (PV) power if thermal storage is incorporated and a direct connection is made between the cooling system and the PV panel. This was accomplished by integrating water as a phase-change material into a well insulated refrigerator cabinet and by developing a microprocessor based control system that allows direct connection of a PV panel to a variable speed compressor. This second innovation also allowed peak power-point tracking from the PV panel and elimination of batteries from the system. First a laboratory unit was developed to prove the concept and then a commercial unit was produced and deployed in a field test. The laboratory unit was used to test many different configurations including thermoelectric, Stirling and vapor compression cooling systems. The final configuration used a vapor compression cooling cycle, vacuum insulation, a passive condenser, an integral evaporator/ thermal storage tank, two 77 watt PV panels and the novel controller mentioned above. The system's only moving part was the variable speed BD35 compressor made by Danfoss. The 365 liter cabinet stayed cold with as little as 274 watt-hours per day average PV power. Battery-free testing was conducted for several months with very good results. The amount of thermal storage, size of compressor and power of PV panels connected can all be adjusted to optimize the design for a given application and climate. In the commercial unit, the high cost of the vacuum insulated refrigerator cabinet and the stainless steel thermal storage tank were addressed in an effort to make the technology commercially viable. This unit started with a 142 liter, mass-produced chest freezer cabinet that had the evaporator integrated into its inner walls

  19. Dissolution of FB-Line Cabinet Sweepings

    Energy Technology Data Exchange (ETDEWEB)

    Crowder, Mark L.

    2005-06-14

    Three FB-Line samples were received by the Savannah River National Laboratory (SRNL) for characterization and evaluation for suitability for HB-Line dissolution. These samples are part of a larger sampling/evaluation program in support of FB-Line deinventory efforts. The samples studied were identified as MC04-147- HBL, MC04-148-HBL, and FBL-SWP-04-016-HBL (N). The first sample, MC04-147-HBL, is a portion of FB-Line Packaging and Stabilization (P&S) materials. The second sample, MC04-148-HBL, is a sweeping from Cabinet 6-8, which is not representative of the mechanical line. The third sample, FBL-SWP-04-016-HBL (N), is an FB-Line North cabinet sweeping. The samples were described by FB-Line personnel as containing plutonium oxide (PuO{sub 2}) which had not been high-fired. This description was generally confirmed by solids analysis and off gas measurements. All three samples were dissolved in 8 M HNO{sub 3}/0.1 M KF at 90-100 C leaving minor amounts of solid residue. During dissolution, sample MC04-147 did not generate hydrogen gas. Sample MC04-148 generated modest amounts of gas, which contained 4.0 to 4.7 volume percent (vol %) hydrogen (H{sub 2}) at a ratio of up to 8.4 x 10{sup -5} mol H{sub 2}/g sample. Sample FBL-SWP-04-016-HBL (N) was nearly completely soluble in 8 M HNO{sub 3}and produced a very small amount of gas. Apparently, the CaF{sub 2} in that sample dissolves and provides sufficient fluoride to support the dissolution of other components.

  20. Stirling Refrigerator

    Science.gov (United States)

    Kagawa, Noboru

    A Stirling cooler (refrigerator) was proposed in 1862 and the first Stirling cooler was put on market in 1955. Since then, many Stirling coolers have been developed and marketed as cryocoolers. Recently, Stirling cycle machines for heating and cooling at near-ambient temperatures between 173 and 400K, are recognized as promising candidates for alternative system which are more compatible with people and the Earth. The ideal cycles of Stirling cycle machine offer the highest thermal efficiencies and the working fluids do not cause serious environmental problems of ozone depletion and global warming. In this review, the basic thermodynamics of Stirling cycle are briefly described to quantify the attractive cycle performance. The fundamentals to realize actual Stirling coolers and heat pumps are introduced in detail. The current status of the Stirling cycle machine technologies is reviewed. Some machines have almost achieved the target performance. Also, duplex-Stirling-cycle and Vuilleumier-cycle machines and their performance are introduced.

  1. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

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

    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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. SolarChill - a solar PV refrigerator without battery

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, P.H.; Poulsen, S.; Katic, I. [Danish Technological Inst., Taastrup (Denmark)

    2004-07-01

    A solar powered refrigerator (SolarChill) has been developed in an international project involving Greenpeace International, GTZ, UNICEF, UNEP, WHO, industrial partners and Danish Technological Institute. The refrigerator is able to operate directly on solar PV panels, without battery or additional electronics, and is therefore suitable for locations where little maintenance and reliable operation is mandatory. The main objective of the SolarChill Project is to help deliver vaccines and refrigeration to the rural poor. To achieve this objective, the SolarChill Project developed - and plans to make freely available a versatile refrigeration technology that is environmentally sound, technologically reliable, and affordable. SolarChill does not use any fluorocarbons in its cooling system or in the insulation. For domestic and small business applications, another type of solar refrigerator is under development. This is an upright type, suitable for cool storage of food and beverages in areas where grid power is non-existent or unstable. The market potential for this type is thus present in industrialised countries as well as in countries under development. The unique feature of SolarChill is that energy is stored in ice instead of in batteries. An ice compartment keeps the cabinet at desired temperatures during the night. The paper describes the product development, possible SolarChill applications and experience with the two types of solar refrigerators, as well as results from the laboratory and field test. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAN

    2003-05-19

    With increased concern about the impact of refrigerant leakage on global warming, a number of new supermarket refrigeration system configurations requiring significantly less refrigerant charge are being considered. In order to help promote the development of advanced systems and expand the knowledge base for energy-efficient supermarket technology, the International Energy Agency (IEA) established IEA Annex 26 (Advanced Supermarket Refrigeration/Heat Recovery Systems) under the ''IEA Implementing Agreement on Heat Pumping Technologies''. Annex 26 focuses on demonstrating and documenting the energy saving and environmental benefits of advanced systems design for food refrigeration and space heating and cooling for supermarkets. Advanced in this context means systems that use less energy, require less refrigerant and produce lower refrigerant emissions. Stated another way, the goal is to identify supermarket refrigeration and HVAC technology options that reduce the total equivalent warming impact (TEWI) of supermarkets by reducing both system energy use (increasing efficiency) and reducing total refrigerant charge. The Annex has five participating countries: Canada, Denmark, Sweden, the United Kingdom, and the United States. The working program of the Annex has involved analytical and experimental investigation of several candidate system design approaches to determine their potential to reduce refrigerant usage and energy consumption. Advanced refrigeration system types investigated include the following: distributed compressor systems--small parallel compressor racks are located in close proximity to the food display cases they serve thus significantly shortening the connecting refrigerant line lengths; secondary loop systems--one or more central chillers are used to refrigerate a secondary coolant (e.g. brine, ice slurry, or CO2) that is pumped to the food display cases on the sales floor; self-contained display cases--each food display case

  6. 24 CFR 3280.204 - Kitchen cabinet protection.

    Science.gov (United States)

    2010-04-01

    ... framing members and trim are exempted from this requirement. The cabinet area over the cooking range or cooktops shall be protected by a metal hood (26-gauge sheet metal, or .017 stainless steel, or .024...

  7. ENERGY STAR Certified Commercial Hot Food Holding Cabinet

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 2.0 ENERGY STAR Program Requirements for Commercial Hot Food Holding Cabinets that are...

  8. [Microcontroller temperature regulator MPT110 for drying-sterilizing cabinets].

    Science.gov (United States)

    Kostin, N N; Gavrishchuk, V I; Zelepukin, S A; Shkulepa, V M; Zharov, E N

    2002-01-01

    The paper describes a MPT-110 temperature microcontroller developed by the closed joint-stock company "OPLEKS" (Orel, Russia) and the results of comparative tests performed in the @IIICC-80 drying sterilizing cabinet. The use of the MPT-110 controller is shown to improve the quality of control and to shorten the times that is taken for the cabinet to reach the preset temperature point.

  9. Microminiature Refrigeration

    Science.gov (United States)

    Little, W. A.

    2008-03-01

    The dramatic growth of industrial cryogenics in the past century has overshadowed the need for cryogenics on a smaller scale. Today, small scale, MEMS or microminiature refrigerators constitute a small part of the field, but one with a unique role to play, often in instrumentation. Key attributes of these coolers have proved to be their small size, low noise, fast response, and low cost. The small size has enabled the integration of the instrument and cooler. The fast response and low noise have made possible instruments of unique capabilities. Opportunities exist for the seamless integration of cryogenics in other products, but to succeed here, companies need strength in both cryogenics and a broad range of other disciplines, including materials science, electronics, and software. To offset economies of scale, new fabrication technologies have had to be created, and others are needed. Some key elements remain to be developed before more widespread use of this technology will be seen. Better miniature heat exchangers and regenerators are needed. Development of miniature compressors to power the coolers could herald a new world of cooled devices analogous to the revolution created by fractional horsepower electric motors in the past fifty years. Opportunities abound!

  10. Spanish cabinet moves to liberalize abortion law.

    Science.gov (United States)

    1995-07-14

    On July 7 (1995), the cabinet of Spain's socialist prime minister Felipe Gonzalez approved a measure to expand the country's abortion law by permitting a woman to obtain the procedure during the first 12 weeks of pregnancy in circumstances not currently allowed. Since 1985, abortion has been legal throughout pregnancy in the following situations: when a medical specialist not associated with the procedure determines that an abortion is necessary to "avert a serious risk to [a woman's] physical or mental health;" during the first 12 weeks if the pregnancy results from reported rape; and within the first 22 weeks when two physicians not associated with the abortion certify that the fetus would develop "severe physical or mental defects." The new legislation, which also requires women to receive nonbinding counseling, permits abortions when a health care professional determines that carrying to term will cause a woman severe anxiety for social or economic reasons. Before the measure can become law, it must be approved by the Spanish Parliament, which is expected to vote on the proposal in September. The Catalan nationalist grouping, which has been a key supporter of the socialist government, is among the forces opposing liberalization of the abortion statute. Partly due to the abortion controversy, the Catalan coalition is expected to vote on July 17 to decide whether to continue its backing. full text

  11. Laboratory biological safety cabinet (BSC) explosion

    Energy Technology Data Exchange (ETDEWEB)

    Al-Dahhan, Wedad H.; Al-Zuhairi, Ali Jasim; Hussein, Falah H.; Rodda, Kabrena E.; Yousif, Emad

    2016-12-01

    Scientists at universities across Iraq are actively working to report actual incidents and accidents occurring in their laboratories in order to raise awareness and encourage openness, leading to widespread adoption of robust Chemical Safety and Security (CSS) practices. This manuscript is the first in a series of five case studies describing laboratory incidents and accidents in Iraqi university laboratories in order to share lessons learned and minimize the possibility of similar incidents in the future. In this study, we describe a serious event that resulted in a postgraduate student sustaining serious injuries when the biological safety cabinet (BSC) she was using exploded. Of particular note, the paper highlights how a combination of failures and deficiencies at many levels within an organization and its technical community (rather than a single piece of faulty equipment or the careless behavior of one person) can lead to a dangerous, potentially life-threatening incident. By openly sharing what happened along with the lessons learned from the accident, we hope to minimize the possibility of another researcher being injured in a similar incident in the future.

  12. Refrigerating machine oil

    Energy Technology Data Exchange (ETDEWEB)

    Nozawa, K.

    1981-03-17

    Refrigerating machine oil to be filled in a sealed motorcompressor unit constituting a refrigerating cycle system including an electric refrigerator, an electric cold-storage box, a small-scaled electric refrigerating show-case, a small-scaled electric cold-storage show-case and the like, is arranged to have a specifically enhanced property, in which smaller initial driving power consumption of the sealed motor-compressor and easier supply of the predetermined amount of the refrigerating machine oil to the refrigerating system are both guaranteed even in a rather low environmental temperature condition.

  13. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  14. Model Based Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth

    for automation of these procedures, that is to incorporate some "intelligence" in the control system, this project was started up. The main emphasis of this work has been on model based methods for system optimizing control in supermarket refrigeration systems. The idea of implementing a system optimizing......-couplings resulting in large disturbances. In supermarkets refrigeration systems the temperature control in the refrigerated display cases are maintained by hysteresis controllers. Based on a model predictive hybrid framework a novel approach for desynchronization is presented. The approach is applied.......e. by degrading the performance. The method has been successfully applied on a test frigeration system for minimization of the power consumption; the hereby gained experimental results will be presented. The present control structure in a supermarket refrigeration system is distributed, which means...

  15. Transcriptomic and metabolomic analysis of Yukon Thellungiella plants grown in cabinets and their natural habitat show phenotypic plasticity

    Directory of Open Access Journals (Sweden)

    Guevara David R

    2012-10-01

    Full Text Available Abstract Background Thellungiella salsuginea is an important model plant due to its natural tolerance to abiotic stresses including salt, cold, and water deficits. Microarray and metabolite profiling have shown that Thellungiella undergoes stress-responsive changes in transcript and organic solute abundance when grown under controlled environmental conditions. However, few reports assess the capacity of plants to display stress-responsive traits in natural habitats where concurrent stresses are the norm. Results To determine whether stress-responsive changes observed in cabinet-grown plants are recapitulated in the field, we analyzed leaf transcript and metabolic profiles of Thellungiella growing in its native Yukon habitat during two years of contrasting meteorological conditions. We found 673 genes showing differential expression between field and unstressed, chamber-grown plants. There were comparatively few overlaps between genes expressed under field and cabinet treatment-specific conditions. Only 20 of 99 drought-responsive genes were expressed both in the field during a year of low precipitation and in plants subjected to drought treatments in cabinets. There was also a general pattern of lower abundance among metabolites found in field plants relative to control or stress-treated plants in growth cabinets. Nutrient availability may explain some of the observed differences. For example, proline accumulated to high levels in cold and salt-stressed cabinet-grown plants but proline content was, by comparison, negligible in plants at a saline Yukon field site. We show that proline accumulated in a stress-responsive manner in Thellungiella plants salinized in growth cabinets and in salt-stressed seedlings when nitrogen was provided at 1.0 mM. In seedlings grown on 0.1 mM nitrogen medium, the proline content was low while carbohydrates increased. The relatively higher content of sugar-like compounds in field plants and seedlings on low nitrogen

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

    National Research Council Canada - National Science Library

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

    2012-01-01

    .... These alternative technologies include: thermoacoustic refrigeration, thermoelectric refrigeration, thermotunneling, magnetic refrigeration, Stirling cycle refrigeration, pulse tube refrigeration, Malone cycle refrigeration, absorption...

  17. Refrigerants for Vapour Compression Refrigeration Systems

    Indian Academy of Sciences (India)

    ; global warming; CFC; HCFC; HFC; HFO; zeotropic mixture; natural fluids. Author Affiliations. G Venkatarathnam1 S Srinivasa Murthy1. Refrigeration and Airconditioning Laboratory, Department of Mechanical Engineering, Indian Institute of ...

  18. Study on the Reduction of Acetic Acid from Cabinets for Microfilms

    OpenAIRE

    佐野, 千絵; 古田嶋, 智子; 井上, さやか; 津田, 徹英; 呂, 俊民

    2012-01-01

    Concentration of acetic acid in cabinets, film storage and adjacent room were measured. Two cabinets were filled with acetic acid generated from aged microfilms. Absorbents were placed in one of the cabinets to remove acetic acid. It was confirmed thatconcentration of acetic acid decreased one week after setting the absorbents. Concentration in the other cabinet in which acetic-acid-absorbents were not placed remained high. From this result, it may be said that the absorbents were effective i...

  19. Vuilleumier Cycle Cryogenic Refrigeration

    Science.gov (United States)

    1976-04-01

    changing pressure to produce a cooling effect is similar to that of the cold section of the Stirling cycle refrigerator , since the method by which the...AFFDL-TR-76-17 VUILLEUMIER CYCLE CRYOGENIC REFRIGERATION ENVIRONMENTAL CONTROL BRANCH 4 VEHICLE EQUIPMENT DIVISION APRIL 1976 TECHNICAL REPORT AFFDL...WORDS (Continue on reverse side if necessary and identify by block number) Cryogenic Refrigerator Vuilleumier Cycle 20. ABSTRACT (Continue on reverse

  20. The wood household furniture and kitchen cabinet industries: a contrast in fortune

    Science.gov (United States)

    William G. Luppold; Matthew S. Bumgardner

    2009-01-01

    In 1977, the value of wood household furniture shipments from domestic manufacturers exceeded kitchen cabinet shipments by 170 percent; conversely, in 2006 shipments of cabinets exceeded shipments of furniture by 78 percent. The most apparent reason for the decrease in domestic furniture shipments is the increase in furniture imports, whereas cabinet demand has...

  1. 21 CFR 1020.40 - Cabinet x-ray systems.

    Science.gov (United States)

    2010-04-01

    ... are all x-ray systems designed primarily for the inspection of carry-on baggage at airline, railroad... target and passing through the window of the x-ray tube. (11) Safety interlock means a device which is... body through any aperture shall not be possible. (4) Safety interlocks. (i) Each door of a cabinet x...

  2. 41 CFR 101-26.308 - Obtaining filing cabinets.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Obtaining filing cabinets. 101-26.308 Section 101-26.308 Public Contracts and Property Management Federal Property Management Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 26-PROCUREMENT SOURCES AND...

  3. Evaluation of a cabinet dryer developed for cassava chips | Taiwo ...

    African Journals Online (AJOL)

    This study aimed at evaluating the performance of a prototype sawdust-‐ fueled and fan-‐forced convection cabinet dryer developed for cassava chips. The specific objectives were to develop regression equations to relate drying (or elapsed) time and moisture content for sun drying and drying of fresh peeled cassava chips ...

  4. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  5. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. De-synchronization of the Distributed Refrigeration System

    DEFF Research Database (Denmark)

    Chen, Liang; Wisniewski, Rafal

    2010-01-01

    The supermarket refrigeration system typically has a distributed control structure, which simple and flexible, however, neglects interactions between its subsystems. Practice shows that these interactions lead to a synchronous operation of the display cases. It causes excessive wear...... on the compressors and increased energy consumption. The paper focuses on the synchronization analysis and de-synchronization control. The supermarket refrigeration system is modeled as a piecewise-affine switched system. The system behavior is decomposed such that synchronization analysis can be completed by using...... performance and can deal with the large scale refrigeration system with different system parameters in the display cases....

  7. Natural refrigerants in commercial and household refrigerators and freezers; Natuurlijke koudemiddelen in commerciele en huishoud koel- en vrieskasten

    Energy Technology Data Exchange (ETDEWEB)

    Havenaar, D.

    2008-01-15

    Refrigerators and freezers manufactured by Gram are completely free of CFCs (including the insulation of the cabinets) because they are using natural refrigerants and save 47-74% energy. Natural refrigerants do not influence the ozon layer and almost they do not contribute to global warming. But they have a higher cooling capacity that requires less refrigerants with the same result. [Dutch] Koel- en vrieskasten van Gram zijn volledig HFK vrij (ook de isolatie van de kasten) en maken gebruik van natuurlijke koudemiddelen en besparen 47-74% energie. Natuurlijke koudemiddelen tasten de ozonlaag niet aan en vormen nagenoeg geen bijdrage aan het broeikaseffect maar hebben een groter koelvermogen, waardoor minder koudemiddelvulling nodig is voor hetzelfde resultaat. Ook wordt gebruik gemaakt van speciale componenten met laag energiegebruik. Het energiegebruik is de helft tot een kwart ten opzichte van gebruikelijke kosten. De besparing op jaarbasis in Nederland bedraagt totaal circa 200.000 kWh. Hierdoor wordt het milieu in de sector 'huishoud- en commerciele koeling' aanzienlijk minder belast.

  8. Refrigerants and environment

    Science.gov (United States)

    Tsvetkov, O. B.; Laptev, Yu A.

    2017-11-01

    The refrigeration and air-conditioning industries are important sectors of the economy and represents about 15 % of global electricity consumptions. The chlorofluorocarbons also called CFCs are a class of refrigerants containing the halogens chlorine and/or fluorine on a carbon skeleton. Because of their environmental impact the Montreal Protocol was negotiated in 1987 to limit the production of certain CFCs and hydrochlirofluorocarbons (HCFCs) in developed and developing countries. The halogenated refrigerants are depleting the ozone layer also major contribution to the greenhouse effect. To be acceptable as a refrigerant a fluid must satisfy a variety of thermodynamic criteria and should be environment friendly with zero Ozone Depletion Potential and low Global Warming Potential. The perspective of a future phase down of HFCs is considered in this report taking into account a strategy for the phase out of HCFCs and perspective of choosing of various refrigerant followed by safety issues.

  9. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Refrigerants for Vapour Compression Refrigeration Systems

    Indian Academy of Sciences (India)

    With the mandate of Montreal Protocol banning ozone de- pleting substances, and Kyoto Protocol later on curtailing the use of substances which contribute to global warming, con- ventional refrigerants are to be replaced by environment- friendly working fluids. Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons ...

  11. Pulse Tube Refrigerator

    Science.gov (United States)

    Matsubara, Yoichi

    The pulse tube refrigerator is one of the regenerative cycle refrigerators such as Stirling cycle or Gifford-McMahon cycle which gives the cooling temperature below 150 K down to liquid helium temperature. In 1963, W. E. Gifford invented a simple refrigeration cycle which is composed of compressor, regenerator and simple tube named as pulse tube which gives a similar function of the expander in Stirling or Gifford-McMahon cycle. The thermodynamically performance of this pulse tube refrigerator is inferior to that of other regenerative cycles. In 1984, however, Mikulin and coworkers made a significant advance in pulse tube configuration called as orifice pulse tube. After this, several modifications of the pulse tube hot end configuration have been developed. With those modifications, the thermodynamic performance of the pulse tube refrigerator became the same order to that of Stirling and Gifford-McMahon refrigerator. This article reviews the brief history of the pulse tube refrigerator development in the view point of its thermodynamically efficiency. Simplified theories of the energy flow in the pulse tube have also been described.

  12. Measurement of the transient shielding effectiveness of shielding cabinets

    Directory of Open Access Journals (Sweden)

    H. Herlemann

    2008-05-01

    Full Text Available Recently, new definitions of shielding effectiveness (SE for high-frequency and transient electromagnetic fields were introduced by Klinkenbusch (2005. Analytical results were shown for closed as well as for non closed cylindrical shields. In the present work, the shielding performance of different shielding cabinets is investigated by means of numerical simulations and measurements inside a fully anechoic chamber and a GTEM-cell. For the GTEM-cell-measurements, a downscaled model of the shielding cabinet is used. For the simulations, the numerical tools CONCEPT II and COMSOL MULTIPHYSICS were available. The numerical results agree well with the measurements. They can be used to interpret the behaviour of the shielding effectiveness of enclosures as function of frequency. From the measurement of the electric and magnetic fields with and without the enclosure in place, the electric and magnetic shielding effectiveness as well as the transient shielding effectiveness of the enclosure are calculated. The transient SE of four different shielding cabinets is determined and discussed.

  13. The toxicity of refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1996-07-01

    This paper presents toxicity data and exposure limits for refrigerants. The data address both acute (short-term, single exposure) and chronic (long-term, repeated exposure) effects, with emphasis on the former. The refrigerants covered include those in common use for the last decade, those used as components in alternatives, and selected candidates for future replacements. The paper also reviews the toxicity indicators used in both safety standards and building, mechanical, and fire codes. It then outlines current classification methods for refrigerant safety and relates them to standard and code usage.

  14. Effects of outside air temperature on the preparation of antineoplastic drug solutions in biological safety cabinets.

    Science.gov (United States)

    Umemura, Masayuki; Itoh, Akio; Ando, Yuichi; Yamada, Kiyofumi; Wakiya, Yoshifumi; Nabeshima, Toshitaka

    2015-08-01

    In Japan, biological safety cabinets are commonly used by medical staff to prepare antineoplastic agents. At the Division of Chemotherapy for Outpatients, Nagoya University Hospital, a class II B2 biological safety cabinet is used. The temperature inside this biological safety cabinet decreases in winter. In this study, we investigated the effect of low outside air temperature on the biological safety cabinet temperature, time required to admix antineoplastic agents, and accuracy of epirubicin weight measurement. Studies were conducted from 1 January to 31 March 2008 (winter). The outside air temperature near the biological safety cabinet intake nozzle was compared with the biological safety cabinet temperature. The correlation between the outside air temperature and the biological safety cabinet temperature, time for cyclophosphamide and gemcitabine solubilization, and accuracy of epirubicin weight measurement were investigated at low and high biological safety cabinet temperatures. The biological safety cabinet temperature correlated with the outside air temperature of 5-20℃ (p < 0.0001). Compared to cyclophosphamide and gemcitabine solubilization in the biological safety cabinet at 25℃, solubilization at 10℃ was significantly delayed (p < 0.01 and p < 0.0001, respectively). Measurement of epirubicin weight by using a syringe lacked accuracy because of epirubicin's high viscosity at low temperatures (p < 0.01). These results suggest that the biological safety cabinet temperature decreases when cool winter air is drawn into the biological safety cabinet, affecting the solubilization of antineoplastic agents. We suggest that a decrease in biological safety cabinet temperature may increase the time required to admix antineoplastic agents, thereby increasing the time for which outpatients must wait for chemotherapy. © The Author(s) 2014.

  15. Quantum-circuit refrigerator

    Science.gov (United States)

    Tan, Kuan Yen; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Masuda, Shumpei; Möttönen, Mikko

    2017-05-01

    Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable electron tunnelling in a nanoscale refrigerator. This result is revealed by a decreased electron temperature at a resonator-coupled probe resistor, even for an elevated electron temperature at the refrigerator. Our conclusions are verified by control experiments and by a good quantitative agreement between theory and experimental observations at various operation voltages and bath temperatures. In the future, we aim to remove spurious dissipation introduced by our refrigerator and to decrease the operational temperature. Such an ideal quantum-circuit refrigerator has potential applications in the initialization of quantum electric devices. In the superconducting quantum computer, for example, fast and accurate reset of the quantum memory is needed.

  16. Quantum-circuit refrigerator

    Science.gov (United States)

    Tan, Kuan Yen; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Masuda, Shumpei; Möttönen, Mikko

    2017-01-01

    Quantum technology promises revolutionizing applications in information processing, communications, sensing and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains challenging in many solid-state implementations, such as superconducting circuits. Here we demonstrate direct cooling of a superconducting resonator mode using voltage-controllable electron tunnelling in a nanoscale refrigerator. This result is revealed by a decreased electron temperature at a resonator-coupled probe resistor, even for an elevated electron temperature at the refrigerator. Our conclusions are verified by control experiments and by a good quantitative agreement between theory and experimental observations at various operation voltages and bath temperatures. In the future, we aim to remove spurious dissipation introduced by our refrigerator and to decrease the operational temperature. Such an ideal quantum-circuit refrigerator has potential applications in the initialization of quantum electric devices. In the superconducting quantum computer, for example, fast and accurate reset of the quantum memory is needed. PMID:28480900

  17. Public Refrigerated Warehouses

    Data.gov (United States)

    Department of Homeland Security — The International Association of Refrigerated Warehouses (IARW) came into existence in 1891 when a number of conventional warehousemen took on the demands of storing...

  18. Refrigeration oils for low GWP refrigerants in various applications

    Science.gov (United States)

    Saito, R.; Sundaresan, S. G.

    2017-08-01

    The practical use of the refrigeration systems is considered as a methods to suppress global warming. The replacement of a refrigerant with a new one that has lower global warming potential (GWP) has been underway for several years. For the application fields of refrigerators, domestic air conditioners, automotive air conditioners and hot water dispensers, the investigation has almost finished. It is still underway for the application fields of commercial air conditioners and chillers, refrigeration facilities for cold storage, etc. And now, the refrigeration system is being applied in various ways to decrease global warming above the generation of electric power with organic Rankine cycle, the binary electric generation with ground source heat pump, and so on. In these situations, various refrigerants are developed and several kinds of suitable refrigeration oils are selected. This paper presents the consideration of suitable refrigeration oil for the various low GWP refrigerants.

  19. Refrigeration systems and applications

    CERN Document Server

    Dincer, Ibrahim

    2010-01-01

    Refrigeration Systems and Applications, 2nd edition offers a comprehensive treatise that addresses real-life technical and operational problems, enabling the reader to gain an understanding of the fundamental principles and the practical applications of refrigeration technology. New and unique analysis techniques (including exergy as a potential tool), models, correlations, procedures and applications are covered, and recent developments in the field are included - many of which are taken from the author's own research activities in this area. The book also includes so

  20. Energy consumption of household refrigerator: experimentation and modelling; Interaction energetique batiment-equipement experimentale et modelisation

    Energy Technology Data Exchange (ETDEWEB)

    Saheb, Y.

    2003-12-01

    Monitoring projects showed that energy consumption of household refrigerators varies from 22% (Denmark) to 41% (Lebanon) of household electricity bill depending of use conditions. To study the influence of each use condition, we monitored during one week, energy consumption of two domestic refrigerators used in normal way by families in Algiers and the ambient temperature of each kitchen. From this, we found correlation between energy consumption of appliances and indoor air temperature. Then, we modelled the system. The equations of the refrigerant loop have been considered in a static mode and solved using Engineering Equation Solver, EES. While the refrigerator cabinet considered in a dynamic mode is a new TRNSYS Type. After that, we coupled this model to an existing building model, Type 56 of TRNSYS library. In the coupling model, the influence of indoor temperature and the heat rejected by the appliance are taken into account. In one hand, the simulation results showed that the influence of ambient temperature on energy consumption is more important for refrigerators with bad insulation. In the other hand, the improving of refrigerator insulation (class G to A) decreases by two-third the energy consumption. This study is supported by the French Agency for Environment and Energy Management. (author)

  1. Sound Radiation from a Loudspeaker Cabinet using the Boundary Element Method

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren

    Ideally, the walls of a loudspeaker cabinet are rigid. However, in reality, the cabinet is excited by the vibration of the loudspeaker units and by the acoustic pressure inside the cabinet. The radiation of sound caused by such vibration can influence the overall performance of the loudspeaker...... had been reported, based on subjective testing. This study aims to detect the reported problem. The radiation from the cabinet is calculated using the Boundary Element Method. The analysis examines both the frequency domain and the time domain characteristics (in other words, the steady state response...... and the impulse response) of the loudspeaker and the cabinet. A significant influence of the cabinet has been detected, which becomes especially apparent in the time domain, during the sound decay process....

  2. Hey you! Shut the refrigerator door!

    Science.gov (United States)

    Fay, Sarah; Portenga, Angela

    1998-09-01

    The note discusses electrical power and energy and includes possible labs to be used in a physics classroom. It is based on our experimentation with a new device called the Watt-Watt/Hour Meter, which displays instantaneous power and cumulative energy readings of household electrical devices. Our experiments utilized this meter in conjunction with various appliances and focused primarily on its use with a refrigerator.

  3. Low Global Warming Potential Refrigerants for Commercial Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Environmental concerns are driving regulations for the heating, ventilating, air-conditioning and refrigeration (HVAC&R) industry towards lower GWP alternatives to HFC refrigerants. Existing lower GWP refrigerant alternatives include hydrocarbons, such as propane (R-290) and isobutane (R-600a), as well as carbon dioxide (R-744), ammonia (R-717), and R-32. In addition, new lower GWP refrigerant alternatives are currently being developed by refrigerant manufacturers, including hydrofluoro-olefin (HFO) and unsaturated hydrochlorofluorocarbon (HCFO) refrigerants. The selection of an appropriate refrigerant for a given refrigeration application should be based on several factors, including the GWP of the refrigerant, the energy consumption of the refrigeration system over its operating lifetime, and leakage of refrigerant over the system lifetime. For example, focusing on energy efficiency alone may overlook the significant environmental impact of refrigerant leakage; while focusing on GWP alone might result in lower efficiency systems that result in higher indirect impact over the equipment lifetime. Thus, the objective of this Collaborative Research and Development Agreement (CRADA) between

  4. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

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

    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.

  5. Construction and performance measurement of a portable thermoacoustic refrigerator demonstration apparatus

    OpenAIRE

    Berhow, Todd J.

    1994-01-01

    Approved for public release; distribution is unlimited This thesis documents the construction and performance measurement of a portable thermoacoustic refrigerator demonstration apparatus. The objective of the portable refrigerator is to graphically display, as a demonstration during lectures, a substantial thermoacoustic cooling power. Within minutes of start up, the apparatus develops frost on a small metal portion of the device. The refrigerator is small and compact and fits into a port...

  6. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. Refrigeration a history

    CERN Document Server

    Gantz, Carroll

    2015-01-01

    For thousands of years, humans coped with heat by harvesting and storing natural ice and devising natural cooling systems that utilized ventilation and evaporation. By the mid 1800s, people began developing huge refrigeration machines to manufacture ice. By the early 1900s, engineers developed electric domestic refrigerators, which by 1927 were affordable convenient household appliances. By then, an increasingly sophisticated public demanded more modern-looking appliances than engineers could produce, and a new breed of designers entered the manufacturing world to provide them. During the Depr

  8. Refrigeration Playbook: Natural Refrigerants; Selecting and Designing Energy-Efficient Commercial Refrigeration Systems That Use Low Global Warming Potential Refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Caleb [CTA Architects Engineers, Boise, ID (United States); Reis, Chuck [CTA Architects Engineers, Boise, ID (United States); Nelson, Eric [CTA Architects Engineers, Boise, ID (United States); Armer, James [CTA Architects Engineers, Boise, ID (United States); Arthur, Rob [CTA Architects Engineers, Boise, ID (United States); Heath, Richard [CTA Architects Engineers, Boise, ID (United States); Rono, James [CTA Architects Engineers, Boise, ID (United States); Hirsch, Adam [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Doebber, Ian [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    This report provides guidance for selecting and designing energy efficient commercial refrigeration systems using low global warming potential refrigerants. Refrigeration systems are generally the largest energy end use in a supermarket type building, often accounting for more than half of a building's energy consumption.

  9. Portable refrigerant charge meter and method for determining the actual refrigerant charge in HVAC systems

    Science.gov (United States)

    Gao, Zhiming; Abdelaziz, Omar; LaClair, Tim L.

    2017-08-08

    A refrigerant charge meter and a method for determining the actual refrigerant charge in HVAC systems are described. The meter includes means for determining an optimum refrigerant charge from system subcooling and system component parameters. The meter also includes means for determining the ratio of the actual refrigerant charge to the optimum refrigerant charge. Finally, the meter includes means for determining the actual refrigerant charge from the optimum refrigerant charge and the ratio of the actual refrigerant charge to the optimum refrigerant charge.

  10. Patterns of post-cabinet careers: When one door closes another door opens?

    NARCIS (Netherlands)

    Dörrenbächer, N.

    2016-01-01

    This article tackles the question to what extent former cabinet members go through the so-called revolving door by starting a second career in the private sector, and what factors make them likely to do so. After a cabinet position, career advancement in the political and public sector is difficult.

  11. Environmental Protection: Observations on Elevating the Environmental Protection Agency to Cabinet Status

    National Research Council Canada - National Science Library

    Stephenson, John

    2002-01-01

    ... major industrial power without a Cabinet-level environmental organization. The additional visibility and prestige that comes with Cabinet status would send the symbolic, but important, message to other federal departments and foreign nations that the United States is fully committed to solving the most serious and complex domestic and global environmental problems.

  12. Electrocaloric refrigeration: an innovative, emerging, eco-friendly refrigeration technique

    Science.gov (United States)

    Aprea, C.; Greco, A.; Maiorino, A.; Masselli, C.

    2017-01-01

    Nowadays, the refrigeration is responsible of about 15% of the overall energy consumption all over the world. Actually most of the refrigerant fluids working in vapor compression plants (VCPs) are environmentally harmful, since they presents high GWP (Global Warming Potential), which leads to a substantial warming of both earth surface and atmosphere. Electrocaloric refrigeration (ER) is an innovative, emerging refrigeration technique based on solid state refrigerant that shows a great potential. It fits in the context of environment-friendly refrigeration systems, whom are spreading increasingly to replace VCPs. ER is founded on electrocaloric effect that is a physical phenomenon found in materials with dielectric properties, electrocaloric materials. The thermodynamical cycle that best is addressed to the electrocaloric refrigeration is Active Electrocaloric Regeneration cycle (AER) that consists of two adiabatic and two isofield stages. The core of an electrocaloric refrigerator is the regenerator whom operates both as refrigerant and regenerator in an AER cycle. In this paper, we compare the energetic performance of a commercial R134a refrigeration plant to that of an electrocaloric refrigerator working with an AER cycle. The comparison is performed in term of TEWI index (Total Equivalent Warming Impact) that includes both direct and indirect contributions to global warming.

  13. Solar Powered Refrigeration System

    Science.gov (United States)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  14. Improved cryogenic refrigeration system

    Science.gov (United States)

    Higa, W. H.

    1967-01-01

    Two-position shuttle valve simplifies valving arrangement and crank-shaft configuration in gas-balancing and Stirling-cycle refrigeration systems used to produce temperatures below 173 degrees K. It connects the displacer and regenerator alternately to the supply line or the return line of the compressor, and establishes constant pressure on the drive piston.

  15. Cryogenic Optical Refrigeration

    Science.gov (United States)

    2012-03-22

    study by Ball Aerospace Corporation showed that rare-earth-based optical refrigeration can outperform conventional thermoelectric and mechanical coolers...J. Cryst. Growth 30(1), 21–26 (1975). 139. J. S. Abell, I. R. Harris, B. Cockayne, and J. G. Plant , “A DTA study of zone-refined LiRF4 (R = Y,Er

  16. Preventing refrigerated foodstuffs in supermarkets from being discarded on hot days by mpc

    DEFF Research Database (Denmark)

    Cai, Junping; Stoustrup, Jakob; Jørgensen, John Bagterp

    2008-01-01

    This paper presents an optimization strategy for supermarket refrigeration systems. It deals with one special condition when the extremely high outdoor temperature causes the compressor to saturate, and work at its maximum capacity. In a traditional control, refrigerated foodstuffs inside display...

  17. Synchronization Analysis of the Supermarket Refrigeration System

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Chen, Liang; Larsen, Lars Finn Sloth

    2009-01-01

    The supermarket refrigeration system typically has a distributed control structure, which neglects interactions between its subsystems. These interactions from time to time lead to a synchronization operation of the display-cases which causes an inferior control performance and increased energy...... consumption. The paper focuses on synchronization dynamics of the refrigeration system modeled as a piecewiseaffine switched system. Stability analysis is performed bygluing the subsystems and polyhedra together to form a single dynamical system defined on a coherent state space. Then, system behavior...... is analyzed using the bifurcation and chaos theory. It is demonstrated that the system can have a complex chaotic behavior, which is far from the synchronization. This shows that making the system chaotic is a good choice for a de-synchronization strategy. The positive maximum Lyapunov exponent is usually...

  18. Ajna: negotiating forms in the making of a musical cabinet

    DEFF Research Database (Denmark)

    Fernaeus, Ylva; Vallgårda, Anna

    2014-01-01

    creators as well as on observations of Ajna performing in different contexts. From the perspective of interaction design, we first analyse the process of its making through the negotiations between physical form, temporal from, and the interactive gestalts. Lastly, we place these negotiations in a larger......Ajna is a musical cabinet made from a rich composition of acoustic materials and designed to perform digitally composed music. In this paper, we aim to unpack the design as well as key aspects of the design process that lead up to this unique artwork. We base our analysis on interviews with its two...... picture of bricolage as a design approach. Based on this we then discuss the qualities of bricolage in interaction design....

  19. Encouraging resilience within SMEs: the Cabinet Office's proposed approach.

    Science.gov (United States)

    Sterling, Stuart

    2011-06-01

    This paper introduces the Cabinet Office's Civil Contingencies Secretariat (CCS). It explains how the National Risk Assessment, produced within the CCS, is created and used. As part of the recent Strategic Defence and Security Review, the Government made a commitment to improve the business continuity of small and medium-sized enterprises (SMEs).This paper describes the CCS's approach to achieving this, and explains why the resilience of SMEs is important to both local communities, at a time of disruption or crisis, and the essential services sectors, such as energy, food and transport. It provides an outline of a strategic approach that will seek to simplify business continuity by making it accessible, achievable and affordable, and, in partnership with the organisations that SMEs turn to for advice, promotes the benefits of business continuity and encourages its use.

  20. A Carboniferous Cabinet of Wonders: an example of how the collaboration of art and Earth Sciences can inspire conservation

    Science.gov (United States)

    Grey, Melissa; Rogers, Janine

    2016-04-01

    The Joggins Fossil Cliffs (Nova Scotia, Canada) is a UNESCO World Heritage Site representing the Late Carboniferous time period (ca. 310-325 mya). The site was formative for Charles Lyell in constructing his geological principles. It is still the best place in the world to view fossils from the Carboniferous 'Coal Age', a time when much of the coal that we use today was formed. The Joggins Fossil Institute is a not-for-profit, charitable organization that co-manages the site with the Province of Nova Scotia. Its mission is to conduct research and educate the public about Earth Sciences through interpretation (e.g., exhibits and tours of the site) and a fossil collection. Fossils are the only direct evidence of how biodiversity has changed over deep time; they are the texts and artifacts that we 'read' in order to understand the development of the earth and that can help humans decipher the deeper histories that produced us. At the Joggins Fossil Institute we primarily present the scientific history of the Carboniferous Period through the use of fossils, but we are also interested in the cultural history of coal production and usage, which is an essential part of the region's economic history. However, this industry has also contributed to climate change and the emergence of a new geological age called the Anthropocene. We encourage our visitors to connect palaeontology and coal energy consumption, and ask them to consider how different values (economic and scientific) are attributed to both coal and fossils; such questions lead directly to discussions about conservation issues. The Joggins Fossil Institute has partnered with the Faculty of Arts at nearby Mount Allison University to create an exhibit that will interrogate these questions. The medium of display that we have chosen is the "cabinet of wonders" or "cabinet of curiosity," which has a rich tradition in western cultures going back to the Renaissance. A venerable intersection of art and science, the cabinet

  1. Model based control of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Sloth Larsen, L.F.

    2005-11-15

    with a distributed control structure, the cross-couplings are not naturally incorporated in the design of the controllers. The disturbances caused by the individual subsystems might be insignificant, however if the effect from all of the subsystems is synchronized it might cause a sever deterioration in the system performance. In the part of the thesis covering dynamical optimization, the main emphasis is laid on analyzing the phenomena of synchronization of hysteresis controlled subsystems. The propose method for desynchronization is based on a model predictive control setup. By formulating a cost function that penalizes the effects of synchronization hard, an optimal control sequence for the subsystems can be computed that desynchronizes the operation. A supermarket's refrigeration system consists of a number of refrigerated display cases located in the supermarkets sales area. The display cases are connected to a central refrigeration system, moreover the temperature control in the display cases is carried out by hysteresis controller. Practice however shows that the display cases have a tendency to synchronize the temperature control. This cause periodically high loads on the central refrigeration system and thereby an increased energy consumption and wear. By studying a nonlinear system model it has been analyzed, which parameter that are important for the synchronization. Applying the proposed method on the nonlinear system model has proved that it is capable of desynchronizing the operation of the display cases. (au)

  2. On Refrigerant Compressors

    OpenAIRE

    McGovern, Jim

    1988-01-01

    The purpose of the work was to critically re-examine and investigate the evaluation of refrigerant compressors and to determine and discriminate between the factors which influence their characteristics. The objectives also included the investigation of techniques by which the characteristics can be established and the suggestion of ways in which compressor performance can be described and quantified. The particular compressor which was tested was of the reciprocating open type. Existing theo...

  3. Multilayer Thermionic Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, G.D.

    1999-08-30

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

  4. Static analysis of rectifier cabinet for nuclear power generating stations based on finite element method

    Science.gov (United States)

    Yin, Qiang; Chen, Tian-jin; Li, Wei-yang; Xiong, Ze-cheng; Ma, Rui

    2017-09-01

    In order to obtain the deformation map and equivalent stress distribution of rectifier cabinet for nuclear power generating stations, the quality distribution of structure and electrical are described, the tensile bond strengths of the rings are checked, and the finite element model of cabinet is set up by ANSYS. The transport conditions of the hoisting state and fork loading state are analyzed. The deformation map and equivalent stress distribution are obtained. The attentive problems are put forward. It is a reference for analysis method and the obtained results for the transport of rectifier cabinet for nuclear power generating stations.

  5. A fault tolerant superheat control strategy for supermarket refrigeration systems

    DEFF Research Database (Denmark)

    Vinther, Kasper; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik

    2013-01-01

    in a plug & play fashion. The strategy is outlined by means of procedural steps as well as a flow chart that also illustrates the process of automatic tuning of the maximum slope-seeking controller. Test results are furthermore presented for a display case in a full scale CO2 supermarket refrigeration...

  6. THERMOELECTRIC REFRIGERATION USING PELTIER EFFECT

    OpenAIRE

    Prof. Rajendra. P. Patil*, Pradhyumna Suryawanshi, Akshay Pawar, Avdhoot Pawar

    2017-01-01

    In the field of military and medical science there are refrigerators used to cool samples or specimens for preservation. They include refrigeration units for storing blood plasma and other blood products, as well as vaccines and other medical or pharmaceutical supplies. They differ from standard refrigerators used in homes or restaurant because they need to be very hygienic and completely reliable. However, in case of transportation of component from one place to another place there is no ref...

  7. THERMODYNAMIC PROPERTIES OF SELECTED HFC REFRIGERANTS

    Science.gov (United States)

    Hydrofluorocarbon (HFC) refrigerants are possible alternatives to replace ozone-depleting chlorofluorocarbon and hydrochlorofluorocarbon (HCFC) refrigerants. The flammability of a proposed new refrigerant is a major consideration in assessing its utility for a particular applicat...

  8. Energy series. What about refrigerators and freezers?

    OpenAIRE

    Grisso, Robert D. (Robert Dwight), 1956-; Walker, Martha A.

    2009-01-01

    In most households, the refrigerator is the single biggest energy consuming kitchen appliance. This publication offers tips for choosing the most energy efficient refrigerator or freezer, operating it efficiently, and recycling your old refrigerator.

  9. Kentucky Transportation Cabinet : annual assessment of customer needs and satisfaction : mail survey report

    Science.gov (United States)

    1997-11-01

    The Kentucky Transportation Cabinet, both through its own quality initiative and a statewide 'Empower Kentucky' campaign, has a commitment to achieve new levels of quality in the development, construction and maintenance of highways. In order to gage...

  10. The Railway Transport Cabinet of the Kyiv Commercial Institute: educational activities and library

    Directory of Open Access Journals (Sweden)

    Afanasievа Z.

    2014-01-01

    Full Text Available In the article the history of foundation and activities of the Railway Transport Cabinet of the Kyiv Commercial Institute are recreated and an attempt is made to trace the way of its library book fonds which "has been lost" during the institute numerous transformations.The Railway Transport Cabinet was established as a supportive educational subdivision of the Merchandising Museum of the Kyiv Commercial Institute. Its purpose was to gather materials on railway science from the improved models of railway transport to the rich collection of specialized literature in foreign languages. In this regard a library was organized in a cabinet; it consisted of professional books and documents covering the railway science, railroads organization and operation, various manuals, diagrams etc. The novelty of the publication lies in the disclosure of the history of the Kyiv Commercial Institute Railway Transport Cabinet library, which has not yet been an object of a special book science research.

  11. Building services cabinets as teaching material in a degree in architecture

    Science.gov (United States)

    Martín-Gómez, César; Zapata, Omayra; Zuazua, Amaia; Villanueva, Sonia; Olaizola, Paula

    2014-03-01

    The aim of this innovative educational project is to encourage students' interest in one of the most underrated fields of architecture: building services. With this material students interact with real elements and thereby understand the relationship between facilities and the building. A set of three small technical cabinets is planned. They allow for comfortable use and movement inside the building, need minimum maintenance and are easily stored. The result is an alternative concept of a mobile laboratory called a 'technical cabinet', made up of three mobile units for fire safety, electricity and the heating/cooling system. The design, content and learning systems of the cabinets confirmed the validity of the initial concept during the first year of use. A protocol has also been developed for each of the technical cabinets so that the teaching experience may be of use in other Schools of Architecture.

  12. Application of Best Industry Practices to the Design of Commercial Refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    None

    2002-06-30

    The substantial efficiency improvements which have been realized in residential refrigerators over the last twenty years due to implementation of the National Appliance Energy Conservation Act and changing consumer reactions to energy savings give an indication of the potential for improvement in the commercial sector, where few such efficiency improvements have been made to date. The purchase decision for commercial refrigerators is still focused primarily on first cost and product performance issues such as maximizing storage capacity, quick pulldown, durability, and reliability. The project applied techniques used extensively to reduce energy use in residential refrigeration to a commercial reach-in refrigerator. The results will also be applicable to other commercial refrigeration equipment, such as refrigerated vending machines, reach-in freezers, beverage merchandisers, etc. The project described in this paper was a collaboration involving the Appliance and Building Technology Sector of TIAX, the Delfield Company, and the U. S. Department of Energy's Office of Building Technologies. Funding was provided by DOE through Cooperative Agreement No. DE-FC26-00NT41000. The program plan and schedule were structured to assure successful integration of the TIAX work on development of efficient design concepts into Delfield's simultaneous development of the Vantage product line. The energy-saving design options evaluated as part of the development included brushless DC and PSC fan motors, high-efficiency compressors, variable-speed compressor technology, cabinet thermal improvement (particularly in the face frame area), increased insulation thickness, a trap for the condensate line, improved insulation, reduced-wattage antisweat heaters, non-electric antisweat heating, off-cycle defrost termination, rifled heat exchanger tubing, and system optimization (selection of heat exchangers, fans, and subcooling, superheat, and suction temperatures for efficient

  13. Implementation of Advanced Inventory Management Functionality in Automated Dispensing Cabinets.

    Science.gov (United States)

    Findlay, Russell; Webb, Aaron; Lund, Jim

    2015-07-01

    Automated dispensing cabinets (ADCs) are an integral component of distribution models in pharmacy departments across the country. There are significant challenges to optimizing ADC inventory management while minimizing use of labor and capital resources. The role of enhanced inventory control functionality is not fully defined. The aim of this project is to improve ADC inventory management by leveraging dynamic inventory standards and a low inventory alert platform. Two interventional groups and 1 historical control were included in the study. Each intervention group consisted of 6 ADCs that tested enhanced inventory management functionality. Interventions included dynamic inventory standards and a low inventory alert messaging system. Following separate implementation of each platform, dynamic inventory and low inventory alert systems were applied concurrently to all 12 ADCs. Outcome measures included number and duration of daily stockouts, ADC inventory turns, and number of phone calls related to stockouts received by pharmacy staff. Low inventory alerts reduced both the number and duration of stockouts. Dynamic inventory standards reduced the number of daily stockouts without changing the inventory turns and duration of stockouts. No change was observed in number of calls related to stockouts made to pharmacy staff. Low inventory alerts and dynamic inventory standards are feasible mechanisms to help optimize ADC inventory management while minimizing labor and capital resources.

  14. Taking Stock: Marie Nimier’s Textual Cabinet of Curiosities

    Directory of Open Access Journals (Sweden)

    Adrienne Angelo

    2014-01-01

    Full Text Available In many life-writing projects, the seemingly innocuous description of heteroclite objects and how those objects are stored and recalled in fact plays an important role in demonstrating their importance to the process of memory work. At once the lingering traces of one’s past and also an aggregation of stories evoked by an examination of them, these curios focus attention on the relationship between the individual and the storage of memories. This article will focus on certain collectibles, collections and collectors that appear throughout the fictional, autobiographical and autofictional world that Marie Nimier has scripted to date. This textual cabinet of curiosities and the act of collecting more generally serve as a trope to connect memory with materiality, despite the numerous narrative voices that Nimier assumes—voices that move from a first-person “Marie Nimier” to an unnamed, although clearly identifiable first-person and even float between genders. Despite this nominal and narrational fluidity, objects function to guarantee recognition, both for the reader, and, especially, for the author herself. What is at stake in this intertextual assemblage of objects is not only the roles that they play in allowing the narrator to revisit past traumas and loss, but also in connecting the author’s presence to other, more fictionalized voices that above all signify the primacy of life-writing in her corpus.

  15. Electrocaloric Refrigeration for Superconductors

    Science.gov (United States)

    1977-02-01

    hardening is unspecified. The error bars on the data are for a 7 W/cmK minimum conductivity and a 14 W/cmK maximum conductivity for OFHC copper at 15 K...shortly. Cooling to as low as 0.05 K was demonstrated in CN doped RbCl . Electrocaloric refrigeration using KCl:OH has been used for ther...ym thicknesses were used along with several bonding agents: epoxy (Epibond 100-A), Corning jlass code 750 AGB devitrifying glaze, and DuPont 822 5

  16. From National Enclaves to Supporting Offices: an Analysis of the 1999 Reform of European Commissioners’ Cabinets

    Directory of Open Access Journals (Sweden)

    Renke Deckarm

    2016-08-01

    Full Text Available This article analyses the transformation of European commissioners’ private offices (cabinets from national enclaves to supporting offices. Structural changes were caused by a reform by then-Commission President Prodi in 1999. To analyse this reform, a typology based on management literature is developed. The reform is characterised as ‘big bang’: it was strategically planned by a leader, transformational and affected the entire cabinet system. The most important measures were that at least three nationalities and three Commission officials were required in cabinets. These and other measures anticipated changing demands towards cabinets caused by the 2004/7 enlargement and the Kinnock reforms. This article closes a gap in research on the Commission, in which cabinets are seldom analysed in their own right. It complements earlier evidence on change in cabinets by explaining why and how structural changes evoked a functional transformation. This contributes to the broader research agenda on change in the functioning of the Commission. Content analysis of primary sources (Prodi’s speeches and publications, expert interviews and a biographic database and recent academic publications contribute to the analysis.

  17. Improving demand response potential of a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Pedersen, Rasmus; Schwensen, John; Biegel, Benjamin

    2017-01-01

    through tests on a full scale supermarket refrigeration system made available by Danfoss A/S. The conducted application test shows that feedback based on food temperature can increase the demand flexibility during a step by approx. 60 % the first 70 minutes and up to 100%over the first 150 minutes...... a method for estimating food temperature based on measurements of evaporator expansion valve opening degree. This method requires no additional hardware or system modeling. We demonstrate the estimation method on a real supermarket display case and the applicability of knowing food temperature is shown...... - thereby strengthening the demand response potential of supermarket refrigeration systems....

  18. Self-supporting refrigerated truck

    NARCIS (Netherlands)

    Beukers, A.; De Winter, S.E.E.; Brouwer, W.D.

    1997-01-01

    Self-supporting refrigerated truck comprising a floor, two side walls, a front bulkhead and a roof. The components are all constructed as sandwich panels. The connection between the rear axle construction of the refrigerated truck and the front is not provided with longitudinal beams. The function

  19. Energy optimisation of domestic refrigerators

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.

    1998-01-01

    This paper describes the main results of a research project with the objective of reducing the energy consumption of domestic refrigerators by increasing the efficiency of the refrigeration system. The improvement of the system efficiency was to be obtained by:1) Introducing continuous operation...

  20. Magnetic refrigerator for hydrogen liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, K; Kondo, T [Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Yoshioka, S; Kamiya, K; Numazawa, T [Tsukuba Magnet Laboratory, National Institute for Materials Science, 3-13 Sakura, Tsukuba 305-0003 (Japan)], E-mail: kmatsu@kenroku.kanazawa-u.ac.jp

    2009-02-01

    Magnetic refrigeration which is based on the magnetocaloric effect of solids has the potential to achieve high thermal efficiency for hydrogen liquefaction. We have been developing a magnetic refrigerator for hydrogen liquefaction which cools down hydrogen gas from liquid natural gas temperature and liquefies at 20 K. The magnetic liquefaction system consists of two magnetic refrigerators: Carnot magnetic refrigerator (CMR) and active magnetic regenerator (AMR) device. CMR with Carnot cycle succeeded in liquefying hydrogen at 20K. Above liquefaction temperature, a regenerative refrigeration cycle should be necessary to precool hydrogen gas, because adiabatic temperature change of magnetic material is reduced due to a large lattice specific heat of magnetic materials. We have tested an AMR device as the precooling stage. It was confirmed for the first time that AMR cycle worked around 20 K.

  1. Auditory Display

    DEFF Research Database (Denmark)

    volume. The conference's topics include auditory exploration of data via sonification and audification; real time monitoring of multivariate date; sound in immersive interfaces and teleoperation; perceptual issues in auditory display; sound in generalized computer interfaces; technologies supporting...... auditory display creation; data handling for auditory display systems; applications of auditory display....

  2. Magnetic Refrigeration and the Magnetocaloric Effect

    DEFF Research Database (Denmark)

    Petersen, Thomas Frank; Pryds, Nini; Smith, Anders

    2006-01-01

    Magnetic refrigeration at room temperature is an emerging technology for refrigeration, which promises low energy consumption and is environmentalle friendly. Magnetic refrigeration is based on the magnetocaloric effect, which manifests itself as a reversibel increase in temperature when magnetic...... material are plased in a magnetic field. This paper introduces and describes magnetic refrigeration cycles and the magnetocaloric effect, and shows how magnetic refrigeration can be an alternative to vapour-compression refrigeration,. A review of the Danish research on magnetic refrigeration at Risø...

  3. Cryogenic refrigeration apparatus

    Science.gov (United States)

    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.

  4. High Efficiency Refrigeration Process Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A refrigeration cycle is proposed for development which can reduce compressor work and increase cooling effect, by eliminating a portion of the irreversabilities...

  5. Thermoacoustic refrigerator for space applications

    Science.gov (United States)

    Garrett, Steven L.; Adeff, Jay A.; Hofler, Thomas J.

    1993-10-01

    A new spacecraft cryocooler which uses resonant high-amplitude sound waves in inert gases to pump heat is described. The phasing of the thermoacoustic cycle is provided by thermal conduction. This 'natural' phasing allows the entire refrigerator to operate with only one moving part (the loudspeaker diaphragm). A space-qualified thermoacoustic refrigerator was flown on the Space Shuttle Discovery (STS-42) in January, 1992. It was entirely autonomous, had no sliding seals, required no lubrication, used mostly low-tolerance machined parts, and contained no expensive components. Thermoacoustics is shown to be a competitive candidate for food refrigerator/freezers and commercial/residential air conditioners. The design and performance of the Space Thermo/Acoustic Refrigerator (STAR) is described.

  6. Regulating Power from Supermarket Refrigeration

    DEFF Research Database (Denmark)

    O'Connell, Niamh; Madsen, Henrik; Pinson, Pierre

    2014-01-01

    This paper presents an analysis of the demand response capabilities of a supermarket refrigeration system, with a particular focus on the suitability for participation in the regulating power market. An ARMAX model of a supermarket refrigeration system is identified using experimental data from...... be represented in a manner that is sufficiently simple to communicate to a market operator in the form of a bid for the provision of regulating power....

  7. Single Party Cabinets and Presidential Democracies: insights from the Argentinean case

    Directory of Open Access Journals (Sweden)

    Marcelo CAMERLO

    2013-07-01

    Full Text Available The study of presidential cabinets has mainly focused on coalitional formations, distinguishing individual ministers in terms of their party affiliation particularly at cabinet instauration and termination. This article moves the focus to single-party cabinets to study minister appointment in situations where the legislative support is less relevant. A model of analysis that observes extra-partisan affiliations, individual technical skills and personal liaison with the president is proposed and exploratory applied to the Argentinean case. The results suggest that well positioned presidents tend to apply closer strategies of portfolio distribution, with levels of institutionalization that depends on the president’s party organization and the president’s style of leadership.

  8. Modeling Supermarket Refrigeration Systems for Supervisory Control in Smart Grid

    OpenAIRE

    Shafiei, Seyed Ehsan; Rasmussen, Henrik,; Stoustrup, Jakob

    2013-01-01

    A modular modeling approach of supermarket refrigeration systems (SRS) which is appropriate for smart grid control purposes is presented in this paper. Modeling and identification are performed by just knowing the system configuration and measured data disregarding the physical details. So, this approach is extendable to different configurations with different modules. The focus of the work is on estimating the power consumption of the system while estimating the display case temperatures as ...

  9. Investigation of Energy-Efficient Supermarket Display Cases

    Energy Technology Data Exchange (ETDEWEB)

    Walker, D.H.

    2005-01-21

    Supermarkets represent one of the largest energy-intensive building groups in the commercial sector, consuming 2 to 3 million kWh/yr per store (ES-1). Over half of this energy use is for the refrigeration of food display cases and storage coolers. Display cases are used throughout a supermarket for the merchandising of perishable food products. The cases are maintained at air temperatures ranging from -10 to 35 F, depending upon the type of product stored. The operating characteristics and energy requirements of the refrigeration system are directly related to the refrigeration load. The sources of the display case refrigeration load consist of: (1) Moist and warm air infiltration through the open front of the case--air curtains are employed to inhibit this infiltration, but some ambient air is entrained, which adds a substantial portion to the refrigeration load. (2) Heat conduction through case panels and walls. (3) Thermal radiation from the ambient to the product and display case interior. (4) Internal thermal loads--the use of lights, evaporator fans, periodic defrosts, and antisweat heaters adds to the refrigeration load of the display case as well as directly consuming electric energy. The impact of each of these elements on the refrigeration load is very dependent upon case type (Figure ES-1). For example, air infiltration is the most significant portion of the refrigeration load for open, multi-deck cases, while radiation is the largest part of the load for tub-type cases. The door anti-sweat heaters represent a major share of the refrigeration load for frozen food door reach-in cases. Figure ES-2 shows the distribution of display cases in a typical supermarket (ES-2). Open, multi-deck, medium temperature display cases typically comprise about half of the refrigerated fixtures in a store (ES-3). In addition, medium temperature fixtures and storage coolers account for roughly 70 to 75 percent of the total store refrigeration load with open, multi-deck cases

  10. 78 FR 76710 - Notice of Buy America Waiver for a Video Ready Access Device Cabinet

    Science.gov (United States)

    2013-12-18

    ... cabinet needed for an AT&T utility relocation associated with the Charlotte Area Transit System's (CATS... Transit System's (CATS or City of Charlotte) LYNX Blue Line Extension (BLE) project, which is an FTA... manufactured goods used in the project are produced in the United States.'' 49 U.S.C. 5323(j)(1). A...

  11. From vanitas to veneration: the embellishments in the anatomical cabinet of Frederik Ruysch

    NARCIS (Netherlands)

    van de Roemer, G.M.

    2010-01-01

    The elaborate way in which the Dutch anatomist Frederik Ruysch (1638-1731) decorated and presented his anatomical cabinet has raised questions as to whether we should view him as a scientist or rather as an artist. The concept of the collection as ‘baroque monument’ or as merely ‘bizarre’ fails to

  12. The Black Box of the Nice Treaty Negotiations: The influence of the Dutch cabinet

    NARCIS (Netherlands)

    S. Luitwieler (Sander)

    2009-01-01

    textabstractThis study applies a relational influence approach to analyse the European Union (EU) Nice Treaty negotiation process (2000) and explain its outcome, focusing on the influence of the Dutch cabinet in the context of the other participating actors (14 member states, the European

  13. Children: Oklahoma's Investment in Tomorrow '96. Preliminary Report: Agency Budget by Cabinet.

    Science.gov (United States)

    Oklahoma Commission on Children and Youth, Oklahoma City.

    This report presents preliminary Oklahoma state agency budget summaries for all programs serving children in the Departments of Administration, Agriculture, Commerce, Education, Energy, Health and Human Services, Human Resources, Safety and Security, Tourism and Recreation, and Veterans Affairs. The budget figures are organized by cabinet and…

  14. A review of pulse tube refrigeration

    Science.gov (United States)

    Radebaugh, Ray

    1990-01-01

    This paper reviews the development of the three types of pulse tube refrigerators: basic, resonant, and orifice types. The principles of operation are given. It is shown that the pulse tube refrigerator is a variation of the Stirling-cycle refrigerator, where the moving displacer is substituted by a heat transfer mechanism or by an orifice to bring about the proper phase shifts between pressure and mass flow rate. A harmonic analysis with phasors is described which gives reasonable results for the refrigeration power, yet is simple enough to make clear the processes which give rise to the refrigeration. The efficiency and refrigeration power are compared with those of other refrigeration cycles. A brief review is given of the research being done at various laboratories on both one- and two-stage pulse tubes. A preliminary assessment of the role of pulse tube refrigerators is discussed.

  15. REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

    Science.gov (United States)

    Large refrigeration systems are found in several applications including supermarkets, cold storage warehouses, and industrial processes. The sizes of these systems are a contributing factor to their problems of high refrigerant leak rates because of the thousands of connections, ...

  16. Refrigeration system having dual suction port compressor

    Science.gov (United States)

    Wu, Guolian

    2016-01-05

    A cooling system for appliances, air conditioners, and other spaces includes a compressor, and a condenser that receives refrigerant from the compressor. The system also includes an evaporator that receives refrigerant from the condenser. Refrigerant received from the condenser flows through an upstream portion of the evaporator. A first portion of the refrigerant flows to the compressor without passing through a downstream portion of the evaporator, and a second portion of the refrigerant from the upstream portion of the condenser flows through the downstream portion of the evaporator after passing through the upstream portion of the evaporator. The second portion of the refrigerant flows to the compressor after passing through the downstream portion of the evaporator. The refrigeration system may be configured to cool an appliance such as a refrigerator and/or freezer, or it may be utilized in air conditioners for buildings, motor vehicles, or other such spaces.

  17. 16 CFR Appendix A2 to Part 305 - Refrigerators and Refrigerators-Freezers With Manual Defrost

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Refrigerators and Refrigerators-Freezers With Manual Defrost A2 Appendix A2 to Part 305 Commercial Practices FEDERAL TRADE COMMISSION... Refrigerators-Freezers With Manual Defrost Range Information Manufacturer's Rated Total Refrigerated Volume in...

  18. Wheel-type magnetic refrigerator

    Science.gov (United States)

    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.

  19. Load forecasting of supermarket refrigeration

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Buth; Bacher, Peder; Madsen, Henrik

    2016-01-01

    This paper presents a novel study of models for forecasting the electrical load for supermarket refrigeration. The data used for building the models consists of load measurements, local climate measurements and weather forecasts. The load measurements are from a supermarket located in a village...... in Denmark. Every hour the hourly electrical load for refrigeration is forecasted for the following 42 h. The forecast models are adaptive linear time series models. The model has two regimes; one for opening hours and one for closing hours, this is modeled by a regime switching model and two different...

  20. Solar Refrigerators Store Life-Saving Vaccines

    Science.gov (United States)

    2014-01-01

    Former Johnson Space Center engineer David Bergeron used his experience on the Advanced Refrigeration Technology Team to found SunDanzer Refrigeration Inc., a company specializing in solar-powered refrigerators. The company has created a battery-free unit that provides safe storage for vaccines in rural and remote areas around the world.

  1. 49 CFR 173.174 - Refrigerating machines.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Refrigerating machines. 173.174 Section 173.174 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Refrigerating machines. A refrigerating machine assembled for shipment and containing 7 kg (15 pounds) or less...

  2. 46 CFR 154.702 - Refrigerated carriage.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigerated carriage. 154.702 Section 154.702 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1...

  3. Method and apparatus for desuperheating refrigerant

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-01-01

    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.

  4. Development of a battery-free solar refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Ewert, Michael K; Bergeron, David J. III [Houston, TX (United States)

    2000-07-01

    Recent technology developments and a systems engineering design approach have led to the development of a practical battery-free solar refrigerator as a spin-off of NASA's aerospace refrigeration research. Off-grid refrigeration is a good application of solar photovoltaic (PV) power thermal storage is incorporated and a direct connection is made between the cooling system and the PV panel. This was accomplished by integrating water as a phase-change material into a well-insulated refrigerator cabinet and by developing a microprocessor-based control system that allows direct connection of a PV panel to a variable-speed compressor. This second innovation also allowed peak power-point tracking from the PV panel and elimination of batteries from the system. First a laboratory unit was developed to prove the concept and then a commercial unit was produced and deployed in a field test. The laboratory unit was used to test many different configurations including thermoelectric., Stirling and vapor compression cooling systems. The final configuration used a vapor compression cooling cycle, vacuum insulation, a passive condenser, and integral evaporator/thermal storage tank, two 77 watt PV panels, and the novel controller mentioned above. The system's only moving part was the variable-speed BD35 compressor made by Danfoss. The 365 liter cabinet stayed cold with as a little as 274 watt-hours per day average PV power. Battery-free testing was conducted for several months with very good results. The amount of thermal storage, size of compressor, and power of PV panels connected can all be adjusted to optimize the design for a given application and climate. In the commercial unit, vacuum insulation and the stainless steel thermal storage tank were not used in order to reduce cost and make the technology commercially viable. This unit started with a 142 liter, mass-produced chest freezer cabinet that had the evaporator integrated into its inner walls. Its compressor

  5. Refrigeration Cycle Design for Refrigerant Mixtures by Molecular Simulation

    Czech Academy of Sciences Publication Activity Database

    Smith, W.R.; Francová, Magda; Kowalski, M.; Nezbeda, Ivo

    2010-01-01

    Roč. 75, č. 4 (2010), s. 383-391 ISSN 0010-0765 R&D Projects: GA AV ČR IAA400720710 Grant - others:NSERC(CA) OGP1041 Institutional research plan: CEZ:AV0Z40720504 Keywords : refrigerants * molecular simulations * vapor–liquid equilibrium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.853, year: 2010

  6. High Efficiency, Low Emission Refrigeration System

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-08-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Methods for reducing refrigerant leakage and energy consumption are available, but underutilized. Further work needs to be done to reduce costs of advanced system designs to improve market utilization. In addition, refrigeration system retrofits that result in reduced energy consumption are needed since the majority of applications address retrofits rather than new stores. The retrofit market is also of most concern since it involves large-volume refrigerant systems with high leak rates. Finally, alternative refrigerants for new and retrofit applications are needed to reduce emissions and reduce the impact on the environment. The objective of this Collaborative Research and Development Agreement (CRADA) between the Oak Ridge National Laboratory and Hill Phoenix is to develop a supermarket refrigeration system that reduces greenhouse gas emissions and has 25 to 30 percent lower energy consumption than existing systems. The outcomes of this project will include the design of a low emission, high efficiency commercial refrigeration system suitable for use in current U.S. supermarkets. In addition, a prototype low emission, high efficiency supermarket refrigeration system will be produced for

  7. Solar-Powered Refrigeration System

    Science.gov (United States)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2001-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure. and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  8. Solar-Powered Refrigeration System

    Science.gov (United States)

    Ewert, Michael K. (Inventor); Bergeron, David J., III (Inventor)

    2002-01-01

    A solar powered vapor compression refrigeration system is made practicable with thermal storage and novel control techniques. In one embodiment, the refrigeration system includes a photovoltaic panel, a variable speed compressor, an insulated enclosure, and a thermal reservoir. The photovoltaic (PV) panel converts sunlight into DC (direct current) electrical power. The DC electrical power drives a compressor that circulates refrigerant through a vapor compression refrigeration loop to extract heat from the insulated enclosure. The thermal reservoir is situated inside the insulated enclosure and includes a phase change material. As heat is extracted from the insulated enclosure, the phase change material is frozen, and thereafter is able to act as a heat sink to maintain the temperature of the insulated enclosure in the absence of sunlight. The conversion of solar power into stored thermal energy is optimized by a compressor control method that effectively maximizes the compressor's usage of available energy. A capacitor is provided to smooth the power voltage and to provide additional current during compressor start-up. A controller monitors the rate of change of the smoothed power voltage to determine if the compressor is operating below or above the available power maximum, and adjusts the compressor speed accordingly. In this manner, the compressor operation is adjusted to convert substantially all available solar power into stored thermal energy.

  9. Magnetic refrigerator for hydrogen liquefaction

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, T [National Institute for Materials Science, Tsukuba (Japan); Kamlya, K. [Japan Atomic Energy Agency, Naka (Japan); Utaki, T. [Osaka University, Osaka (Japan); Matsumoto, K. [Kanazawa University, Kanazawa (Japan)

    2013-06-15

    This paper reviews the development status of magnetic refrigeration system for hydrogen liquefaction. There is no doubt that hydrogen is one of most important energy sources in the near future. In particular, liquid hydrogen can be utilized for infrastructure construction consisting of storage and transportation. Liquid hydrogen is in cryogenic temperatures and therefore high efficient liquefaction method must be studied. Magnetic refrigeration which uses the magneto-caloric effect has potential to realize not only the higher liquefaction efficiency > 50 %, but also to be environmentally friendly and cost effective. Our hydrogen magnetic refrigeration system consists of Carnot cycle for liquefaction stage and AMR (active magnetic regenerator) cycle for precooling stages. For the Carnot cycle, we develop the high efficient system > 80 % liquefaction efficiency by using the heat pipe. For the AMR cycle, we studied two kinds of displacer systems, which transferred the working fluid. We confirmed the AMR effect with the cooling temperature span of 12 K for 1.8 T of the magnetic field and 6 second of the cycle. By using the simulation, we estimate the total efficiency of the hydrogen liquefaction plant for 10 kg/day. A FOM of 0.47 is obtained in the magnetic refrigeration system operation temperature between 20 K and 77 K including LN2 work input.

  10. Keeping Cool With Solar-Powered Refrigeration

    Science.gov (United States)

    2003-01-01

    In the midst of developing battery-free, solar-powered refrigeration and air conditioning systems for habitats in space, David Bergeron, the team leader for NASA's Advanced Refrigerator Technology Team at Johnson Space Center, acknowledged the need for a comparable solar refrigerator that could operate in conjunction with the simple lighting systems already in place on Earth. Bergeron, a 20-year veteran in the aerospace industry, founded the company Solus Refrigeration, Inc., in 1999 to take the patented advanced refrigeration technology he co-developed with his teammate, Johnson engineer Michael Ewert, to commercial markets. Now known as SunDanzer Refrigeration, Inc., Bergeron's company is producing battery-free, photovoltaic (PV) refrigeration systems under license to NASA, and selling them globally.

  11. When are solar refrigerators less costly than on-grid refrigerators: A simulation modeling study.

    Science.gov (United States)

    Haidari, Leila A; Brown, Shawn T; Wedlock, Patrick; Connor, Diana L; Spiker, Marie; Lee, Bruce Y

    2017-04-19

    Gavi recommends solar refrigerators for vaccine storage in areas with less than eight hours of electricity per day, and WHO guidelines are more conservative. The question remains: Can solar refrigerators provide value where electrical outages are less frequent? Using a HERMES-generated computational model of the Mozambique routine immunization supply chain, we simulated the use of solar versus electric mains-powered refrigerators (hereafter referred to as "electric refrigerators") at different locations in the supply chain under various circumstances. At their current price premium, the annual cost of each solar refrigerator is 132% more than each electric refrigerator at the district level and 241% more at health facilities. Solar refrigerators provided savings over electric refrigerators when one-day electrical outages occurred more than five times per year at either the district level or the health facilities, even when the electric refrigerator holdover time exceeded the duration of the outage. Two-day outages occurring more than three times per year at the district level or more than twice per year at the health facilities also caused solar refrigerators to be cost saving. Lowering the annual cost of a solar refrigerator to 75% more than an electric refrigerator allowed solar refrigerators to be cost saving at either level when one-day outages occurred more than once per year, or when two-day outages occurred more than once per year at the district level or even once per year at the health facilities. Our study supports WHO and Gavi guidelines. In fact, solar refrigerators may provide savings in total cost per dose administered over electrical refrigerators when electrical outages are less frequent. Our study identified the frequency and duration at which electrical outages need to occur for solar refrigerators to provide savings in total cost per dose administered over electric refrigerators at different solar refrigerator prices. Copyright © 2017. Published

  12. Dilution Refrigerator for Nuclear Refrigeration and Cryogenic Thermometry Studies

    Science.gov (United States)

    Nakagawa, Hisashi; Hata, Tohru

    2014-07-01

    This study explores the design and construction of an ultra-low temperature facility in order to realize the Provisional low-temperature scale from 0.9 mK to 1 K (PLTS-2000) in Japan, to disseminate its use through calibration services, and to study thermometry at low temperatures below 1 K. To this end, a dilution refrigerator was constructed in-house that has four sintered silver discrete heat exchangers for use as a precooling stage of a copper nuclear demagnetization stage. A melting curve thermometer attached to the mixing chamber flange could be cooled continuously to 4.0 mK using the refrigerator. The dependence of minimum temperatures on circulation rates can be explained by the calculation of Frossati's formula based on a perfect continuous counterflow heat exchanger model, assuming that the Kapitza resistance has a temperature dependence. Residual heat leakage to the mixing chamber was estimated to be around 86 nW. A nuclear demagnetization cryostat with a nuclear stage containing an effective amount of copper (51 mol in a 9 T magnetic field) is under construction, and we will presently start to work toward the realization of the PLTS-2000. In this article, the design and performance of the dilution refrigerator are reported.

  13. The activity of the Cabinet of Ukrainian Art History of the All-Ukrainian Academy of Sciences

    Directory of Open Access Journals (Sweden)

    M. I. Sichka

    2016-05-01

    As a result of this research it was recognized that Cabinet besides collecting the materials was study and developed issues of the history of Ukrainian art «from ancient times to the present», including Shevchenko as an artist, history of architecture and music. Moreover, members of Cabinet prepared materials for encyclopedias, and dictionaries of Ukrainian art History, involved in the museum activity in Kyiv and Moscow, popularized Ukrainian art.

  14. Cabinet Appointment in Uruguay: Legislative Strategy, hierarchy of portfolio and party affiliation of ministers

    Directory of Open Access Journals (Sweden)

    Daniel CHASQUETTI

    2013-07-01

    Full Text Available The article analyzes the formation and change of presidential cabinets in Uruguay during the period 1985-2010. In the first section we present the institutional and political features of the process of appointment and resignation of the ministers. The second section describes the cabinets formed in this period and shows that presidents have exchanged seats in cabinet by legislative support. The third section analyzes the political attributes of the ministers appointed (party affiliation, previous experience and the type of linkage that they keep with the president. The fourth analyze the relationship between the time survival of the individuals in office, the political responsibility in front of congress and the existence of a legislative majority that support the president. The last section describes the Uruguayan pattern of ministerial designation based in (i the establishment of an order of importance of portfolios, (ii the nomination of individuals with party affiliation (weather insider or adherent politicians and (iii the influence of the legislative support in defining the ministerial team.

  15. Improving the Sun Drying of Apricots (Prunus armeniaca) with Photo-Selective Dryer Cabinet Materials.

    Science.gov (United States)

    Milczarek, Rebecca R; Avena-Mascareno, Roberto; Alonzo, Jérôme; Fichot, Mélissa I

    2016-10-01

    Photo-selective materials have been studied for their effects on the preharvest quality of horticultural crops, but little work has been done on potential postharvest processing effects. The aim of this work was to characterize the effects of 5 different photo-selective acrylic materials (used as the lid to a single-layer sun drying cabinet) on the drying rate and quality of apricots (Prunus armeniaca). Photo-selective cabinet materials that transmit light in the visible portion of the solar spectrum accelerate the apricots' drying rate in both the early period of drying and the course of drying as a whole. These materials do not significantly affect the measured quality metrics during the first day of sun drying. However, when drying is taken to completion, some minor but significant quality differences are observed. Infrared-blocking material produces dried apricot with lower red color, compared to clear, opaque black, and ultraviolet-blocking materials. Clear material produced dried apricot with significantly lower antioxidant activity, compared to black and infrared-blocking materials. Using appropriate photo-selective drying cabinet materials can reduce the required sun drying time for apricots by 1 to 2 d, compared with fully shaded drying. Ultraviolet-blocking material is recommended to maximize drying rate and minimize quality degradation. © 2016 Institute of Food Technologists®.

  16. DEVELOPMENT OF PROTOTYPE SYSTEM FOR REGULATING THERMAL CONDITIONS OF TELECOMMUNICATIONS EQUIPMENT CABINETS

    Directory of Open Access Journals (Sweden)

    A. T. Rashidkhanov

    2017-01-01

    Full Text Available Objectives. The main objective of the study was to regulate the thermal regime and ensure the reliability of electronic equipmentMethods. In order to conduct experimental studies of the thermoelectric cooling system using heat pipes, a stand was assembled on which the developed and manufactured prototype was studied. The object of the experimental studies was a prototype cooling system, consisting of a thermoelectric battery made of conventional unified thermoelectric materials of ICE-71 type. The solution of the research problems carried out by the method of reduction to ordinary differential equations (Kantorovich method provides acceptable accuracy for such a class of problems.Results. A design of a telecommunication equipment cabinet with a thermal management system based on the use of heat pipes and thermoelectric cooling units is proposed. A mathematical model for the determination of the thermal field in the cabinet volume is considered; an experimental stand for the prototype study is described; the results of experimental studies for various power sources of heat release are presented.Conclusion. Experimental studies confirm the operability of the developed cooling system for cabinets with telecommunication equipment; this cooling method has advantages over conventional forced or natural cooling; the temperature in the block volume and the peak values of the heat sources are significantly reduced; at dissipation powers on one board within 50 W there is no need to use special means to remove heat from hot junctions of the thermoelectric battery.

  17. Computation of sound radiation by a driver in a cabinet using a substitute source approach.

    Science.gov (United States)

    Lindberg, Anders; Pavić, Goran

    2015-08-01

    Sound radiation by a driver set in a rigid closed cabinet is modeled analytically using the principle of wave superposition. The driver-cabinet assembly is replaced by an array of volumeless substitute sources-monopoles-confined within its surface. The role of substitute sources is to reproduce the sound field exterior to the surface as close to the original field as possible. The frequency dependent positions and strengths of substitute monopoles are optimized by an iterative search procedure aimed at matching the prescribed surface boundary conditions of the original source. The time-consuming optimization of monopole positions is carried out at narrowband center frequencies reducing the computational cost without significant loss of accuracy. The consistency of computed results is verified by checking the power output through the cabinet surface. Modeling is done for anechoic and semi-anechoic conditions. The model has been validated experimentally in a semi-anechoic room with satisfactory results using a mid-range driver set in a closed-box baffle.

  18. Study on the Materials for Compressor and Reliability of Refrigeration Circuit in Refrigerator with R134a Refrigerant

    Science.gov (United States)

    Komatsubara, Takeo; Sunaga, Takasi; Takahasi, Yasuki

    R134a was selected as the alternative refrigerant for R12 because of the similar thermodynamic properties with R12. But refrigeration oil for R12 couldn't be used for R134a because of the immiscibility with R134a. To solve this problem we researched miscible oil with R134a and selected polyol ester oil (POE) as refrigeration oil. But we found sludge deposition into capillary tube after life test of refrigerator with POE and detected metal soap, decomposed oil and alkaline ions by analysis of sludge. This results was proof of phenomena like oil degradation, precipitation of process materials and wear of compressor. Therefore we improved stability and lubricity of POE, reevaluated process materials and contaminations in refrigerating circuit. In this paper we discuss newly developed these technologies and evaluation results of it by life test of refrigerator.

  19. When are solar refrigerators less costly than on-grid refrigerators: A simulation modeling study☆

    Science.gov (United States)

    Haidari, Leila A.; Brown, Shawn T.; Wedlock, Patrick; Connor, Diana L.; Spiker, Marie; Lee, Bruce Y.

    2017-01-01

    Background Gavi recommends solar refrigerators for vaccine storage in areas with less than eight hours of electricity per day, and WHO guidelines are more conservative. The question remains: Can solar refrigerators provide value where electrical outages are less frequent? Methods Using a HERMES-generated computational model of the Mozambique routine immunization supply chain, we simulated the use of solar versus electric mains-powered refrigerators (hereafter referred to as “electric refrigerators”) at different locations in the supply chain under various circumstances. Results At their current price premium, the annual cost of each solar refrigerator is 132% more than each electric refrigerator at the district level and 241% more at health facilities. Solar refrigerators provided savings over electric refrigerators when one-day electrical outages occurred more than five times per year at either the district level or the health facilities, even when the electric refrigerator holdover time exceeded the duration of the outage. Two-day outages occurring more than three times per year at the district level or more than twice per year at the health facilities also caused solar refrigerators to be cost saving. Lowering the annual cost of a solar refrigerator to 75% more than an electric refrigerator allowed solar refrigerators to be cost saving at either level when one-day outages occurred more than once per year, or when two-day outages occurred more than once per year at the district level or even once per year at the health facilities. Conclusion Our study supports WHO and Gavi guidelines. In fact, solar refrigerators may provide savings in total cost per dose administered over electrical refrigerators when electrical outages are less frequent. Our study identified the frequency and duration at which electrical outages need to occur for solar refrigerators to provide savings in total cost per dose administered over electric refrigerators at different solar

  20. Load forecasting of supermarket refrigeration

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Buth; Bacher, Peder; Madsen, Henrik

    2016-01-01

    This paper presents a novel study of models for forecasting the electrical load for supermarket refrigeration. The data used for building the models consists of load measurements, local climate measurements and weather forecasts. The load measurements are from a supermarket located in a village...... in Denmark. Every hour the hourly electrical load for refrigeration is forecasted for the following 42 h. The forecast models are adaptive linear time series models. The model has two regimes; one for opening hours and one for closing hours, this is modeled by a regime switching model and two different...... methods for predicting the regimes are tested. The dynamic relation between the weather and the load is modeled by simple transfer functions and the non-linearities are described using spline functions. The results are thoroughly evaluated and it is shown that the spline functions are suitable...

  1. CO2 as a refrigerant

    CERN Document Server

    2014-01-01

    A first edition, the IIR guide “CO2 as a Refrigerant” highlights the application of carbon dioxide in supermarkets, industrial freezers, refrigerated transport, and cold stores as well as ice rinks, chillers, air conditioning systems, data centers and heat pumps. This guide is for design and development engineers needing instruction and inspiration as well as non-technical experts seeking background information on a specific topic. Written by Dr A.B. Pearson, a well-known expert in the field who has considerable experience in the use of CO2 as a refrigerant. Main topics: Thermophysical properties of CO2 – Exposure to CO2, safety precautions – CO2 Plant Design – CO2 applications – Future prospects – Standards and regulations – Bibliography.

  2. Mountain Plains Learning Experience Guide: Heating, Refrigeration, & Air Conditioning.

    Science.gov (United States)

    Carey, John

    This Heating, Refrigeration, and Air Conditioning course is comprised of eleven individualized units: (1) Refrigeration Tools, Materials, and Refrigerant; (2) Basic Heating and Air Conditioning; (3) Sealed System Repairs; (4) Basic Refrigeration Systems; (5) Compression Systems and Compressors; (6) Refrigeration Controls; (7) Electric Circuit…

  3. Suction muffler for refrigeration compressor

    Science.gov (United States)

    Nelson, Richard T.; Middleton, Marc G.

    1983-01-01

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

  4. Carbon Dioxide in Supermarket Refrigeration

    OpenAIRE

    Sawalha, Samer

    2008-01-01

    This thesis theoretically and experimentally investigates different aspects of the application of CO2 in supermarket refrigeration. Theoretical analysis has been performed using computer simulation models developed to simulate CO2 indirect, NH3/CO2 cascade, CO2 trans-critical and direct expansion (DX) R404A systems. The models supported the selection of the CO2 system solutions to be tested experimentally and facilitated the design of NH3/CO2 cascade and trans-critical systems test rigs. Perf...

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

    Energy Technology Data Exchange (ETDEWEB)

    Dieckmann, John [TIAX LLC, Lexington, MA (United States)

    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.

  6. High-Performance, Low Environmental Impact Refrigerants

    Science.gov (United States)

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

    2001-01-01

    Refrigerants used in process and facilities systems in the US include R-12, R-22, R-123, R-134a, R-404A, R-410A, R-500, and R-502. All but R-134a, R-404A, and R-410A contain ozone-depleting substances that will be phased out under the Montreal Protocol. Some of the substitutes do not perform as well as the refrigerants they are replacing, require new equipment, and have relatively high global warming potentials (GWPs). New refrigerants are needed that addresses environmental, safety, and performance issues simultaneously. In efforts sponsored by Ikon Corporation, NASA Kennedy Space Center (KSC), and the US Environmental Protection Agency (EPA), ETEC has developed and tested a new class of refrigerants, the Ikon (registered) refrigerants, based on iodofluorocarbons (IFCs). These refrigerants are nonflammable, have essentially zero ozone-depletion potential (ODP), low GWP, high performance (energy efficiency and capacity), and can be dropped into much existing equipment.

  7. HeREF-2003 : Helium Refrigeration Techniques

    CERN Multimedia

    2003-01-01

    CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. • Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003 • Cost per participant: 500.- CHF ...

  8. HeREF-2003: Helium Refrigeration Techniques

    CERN Multimedia

    2003-01-01

    CERN Technical Training 2003: Learning for the LHC ! Theory, Technology, Maintenance and Control of Helium Refrigerators HeREF-2003 is a course in the framework of the 2002 Technical Training Programme, that will provide a complete introduction to Helium refrigeration, with a practical approach to theory, technology, maintenance and control of Helium refrigeration installations. Theoretical aspects and equations will be limited to a minimum. HeREF-2003 targets an audience of technicians and operators of Helium refrigeration plants at CERN, as well as physicists and engineers needing an overview of current Helium refrigeration techniques. HeREF-2003 will address, among other, issues related to component technology, installation maintenance, process control and Helium purity. A commented visit to a couple of CERN Helium refrigeration or liquefaction plants will also take place. Duration: 7 half days (4 mornings and 3 afternoons), 6-10 October, 2003 Cost per participant: 500.- CHF Language: Bilingual English...

  9. Numerical model for thermoeconomic diagnosis in commercial transcritical/subcritical booster refrigeration systems

    DEFF Research Database (Denmark)

    Ommen, Torben; Elmegaard, Brian

    2012-01-01

    cycle supplying refrigerant for evaporators in both chilled and frozen display cases. In the paper, thermoeconomic theory is used to establish the cost of cooling at each individual temperature level based on operating costs.With a high amount of operating systems, faulty operation becomes an economic...

  10. Improving spinach quality and reducing energy costs by retrofitting retail open refrigerated cases with doors

    Science.gov (United States)

    The prevalence of open-refrigerated display cases is ubiquitous in retail supermarkets, even in the face of the non-uniform temperature conditions present in these cases that may affect the quality and safety of the stored products. In this paper, the temperature variations ('T) of packaged ready-t...

  11. Adsorption refrigeration technology theory and application

    CERN Document Server

    Wang, Ruzhu; Wu, Jingyi

    2014-01-01

    Gives readers a detailed understanding of adsorption refrigeration technology, with a focus on practical applications and environmental concerns Systematically covering the technology of adsorption refrigeration, this book provides readers with a technical understanding of the topic as well as detailed information on the state-of-the-art from leading researchers in the field. Introducing readers to background on the development of adsorption refrigeration, the authors also cover the development of adsorbents, various thermodynamic theories, the design of adsorption systems and adsorption refri

  12. Refrigeration for a supraconducting 1000 MVA generator

    Energy Technology Data Exchange (ETDEWEB)

    Nienaber, U.; Stephan, A.; Weber, J.

    1985-01-01

    The author discusses the requirements made on the refrigerating system for high-capacity turbogenerators. He presents the block diagram of the refrigerating system, explains the associated tasks, demonstrates the selected process by means of the process flow diagram of the He refrigerator system, describes the major components like loop compressor with oil separator, gas and oil flow, cold box, expansion turbine and process control. (HAG).

  13. Energy efficient for refrigeration and air conditioning

    OpenAIRE

    Abdeen Mustafa Omer

    2015-01-01

    Over the years, all parts of a commercial refrigerator, such as the compressor, heat exchangers, refrigerant, and packaging, have been improved considerably due to the extensive research and development efforts carried out by academia and industry. However, the achieved and anticipated improvement in conventional refrigeration technology are incremental since this technology is already nearing its fundamentals limit of energy efficiency is described is ‘magnetic refrigeration’ which is an evo...

  14. Piezoelectric driven thermo-acoustic refrigerator

    Science.gov (United States)

    Chinn, D. G.; Nouh, M.; Aldraihem, O.; Baz, A.

    2011-03-01

    Thermoacoustic refrigeration is an emerging refrigeration technology which does not rely for in its operation on the use of any moving parts or harmful refrigerants. This technology uses acoustic waves to pump heat across a temperature gradient. The vast majority of thermoacoustic refrigerators to date have used electromagnetic loudspeakers to generate the acoustic input. In this paper, the design, construction, operation, and modeling of a piezoelectric-driven thermoacoustic refrigerator are detailed. This refrigerator demonstrates the effectiveness of piezoelectric actuation in moving 0.3 W of heat across an 18 degree C temperature difference with an input power of 7.6 W. The performance characteristics of this class of thermoacoustic-piezoelectric refrigerator are modeled using DeltaEC software and the predictions are validated experimentally. The obtained results confirm the validity of the developed model. Furthermore, the potential of piezoelectric actuation as effective means for driving thermoacoustic refrigerators is demonstrated as compared to the conventional electromagnetic loudspeakers which are heavy and require high actuation energy. The developed theoretical and experimental tools can serve as invaluable means for the design and testing of other piezoelectric driven thermoacoustic refrigerator configurations.

  15. Refrigerant charge management in a heat pump water heater

    Science.gov (United States)

    Chen, Jie; Hampton, Justin W.

    2016-07-05

    Heat pumps that heat or cool a space and that also heat water, refrigerant management systems for such heat pumps, and methods of managing refrigerant charge. Various embodiments remove idle refrigerant from a heat exchanger that is not needed for transferring heat by opening a refrigerant recovery valve and delivering the idle refrigerant from the heat exchanger to an inlet port on the compressor. The heat exchanger can be isolated by closing an electronic expansion valve, actuating a refrigerant management valve, or both. Refrigerant charge can be controlled by controlling how much refrigerant is drawn from the heat exchanger, by letting some refrigerant back into the heat exchanger, or both. Heat pumps can be operated in different modes of operation, and various components can be interconnected with refrigerant conduit. Some embodiments deliver refrigerant gas to the heat exchanger and drive liquid refrigerant out prior to isolating the heat exchanger.

  16. Refrigeration generation using expander-generator units

    Science.gov (United States)

    Klimenko, A. V.; Agababov, V. S.; Koryagin, A. V.; Baidakova, Yu. O.

    2016-05-01

    The problems of using the expander-generator unit (EGU) to generate refrigeration, along with electricity were considered. It is shown that, on the level of the temperatures of refrigeration flows using the EGU, one can provide the refrigeration supply of the different consumers: ventilation and air conditioning plants and industrial refrigerators and freezers. The analysis of influence of process parameters on the cooling power of the EGU, which depends on the parameters of the gas expansion process in the expander and temperatures of cooled environment, was carried out. The schematic diagram of refrigeration generation plant based on EGU is presented. The features and advantages of EGU to generate refrigeration compared with thermotransformer of steam compressive and absorption types were shown, namely: there is no need to use the energy generated by burning fuel to operate the EGU; beneficial use of the heat delivered to gas from the flow being cooled in equipment operating on gas; energy production along with refrigeration generation, which makes it possible to create, using EGU, the trigeneration plants without using the energy power equipment. It is shown that the level of the temperatures of refrigeration flows, which can be obtained by using the EGU on existing technological decompression stations of the transported gas, allows providing the refrigeration supply of various consumers. The information that the refrigeration capacity of an expander-generator unit not only depends on the parameters of the process of expansion of gas flowing in the expander (flow rate, temperatures and pressures at the inlet and outlet) but it is also determined by the temperature needed for a consumer and the initial temperature of the flow of the refrigeration-carrier being cooled. The conclusion was made that the expander-generator units can be used to create trigeneration plants both at major power plants and at small energy.

  17. TRANSPORT PROPERTIES FOR REFRIGERANT MIXTURES

    Directory of Open Access Journals (Sweden)

    V. Geller

    2014-06-01

    Full Text Available A set of models to predict viscosity and thermal conductivity of refrigerant mixtures is developed. A general model for viscosity and thermal conductivity use the three contributions sum form (the dilute-gas terms, the residual terms, and the liquid terms. The corresponding states model is recommended to predict the dense gas transport properties over a range of reduced density from 0 to 2. It is shown that the RHS model provides the most reliable results for the saturated-liquid and the compressed-liquid transport properties over a range of given temperatures from 0,5 to 0,95.

  18. Refrigeration and air-conditioning

    CERN Document Server

    Hundy, G H; Welch, T C

    2008-01-01

    Now in its fourth edition, this respected text delivers a comprehensive introduction to the principles and practice of refrigeration. Clear and straightforward, it is designed for students (NVQ/vocational level) and professional HVAC engineers, including those on short or CPD courses. Inexperienced readers are provided with a comprehensive introduction to the fundamentals of the technology. With its concise style yet broad sweep the book covers most of the applications professionals will encounter, enabling them to understand, specify, commission, use and maintain these systems. Many readers w

  19. Advanced Refrigerant-Based Cooling Technologies for Information and Communication Infrastructure (ARCTIC)

    Energy Technology Data Exchange (ETDEWEB)

    Salamon, Todd

    2012-12-13

    Faster, more powerful and dense computing hardware generates significant heat and imposes considerable data center cooling requirements. Traditional computer room air conditioning (CRAC) cooling methods are proving increasingly cost-ineffective and inefficient. Studies show that using the volume of room air as a heat exchange medium is wasteful and allows for substantial mixing of hot and cold air. Further, it limits cabinet/frame/rack density because it cannot effectively cool high heat density equipment that is spaced closely together. A more cost-effective, efficient solution for maximizing heat transfer and enabling higher heat density equipment frames can be accomplished by utilizing properly positioned phase change or two-phase pumped refrigerant cooling methods. Pumping low pressure, oil-free phase changing refrigerant through microchannel heat exchangers can provide up to 90% less energy consumption for the primary cooling loop within the room. The primary benefits of such a solution include reduced energy requirements, optimized utilization of data center space, and lower OPEX and CAPEX. Alcatel-Lucent recently developed a modular cooling technology based on a pumped two-phase refrigerant that removes heat directly at the shelf level of equipment racks. The key elements that comprise the modular cooling technology consist of the following. A pump delivers liquid refrigerant to finned microchannel heat exchangers mounted on the back of equipment racks. Fans drive air through the equipment shelf, where the air gains heat dissipated by the electronic components therein. Prior to exiting the rack, the heated air passes through the heat exchangers, where it is cooled back down to the temperature level of the air entering the frame by vaporization of the refrigerant, which is subsequently returned to a condenser where it is liquefied and recirculated by the pump. All the cooling air enters and leaves the shelves/racks at nominally the same temperature. Results

  20. Energy efficient control of a refrigeration plant

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Larsen, Lars F. S.

    2009-01-01

    This paper proposes a novel method for superheat and capacity control of refrigeration systems. The new idea is to control the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed and used in a backstepping design o...... and the methods are evaluated with respect to energy efficiency....

  1. ACTIVATED CARBON/REFRIGERANT COMBINATIONS FOR ...

    African Journals Online (AJOL)

    ES Obe

    No. 1, March, 2001. 53. ACTIVATED CARBON/REFRIGERANT COMBINATIONS. FOR SOLAR REFRIGERATION APPLICATION. By. E.E. ANYANWU. 1. AND N.V. .... may be assumed that the perfect gas law is obeyed approximately by the vapour. Thus,. (2). Hence by integrating,. This linear relationship between log P and.

  2. Natural refrigerants. Special issue; Natuurlijke koudemiddelen. Special

    Energy Technology Data Exchange (ETDEWEB)

    Hoogkamer, J.; Forbes Pearson, S.; Van der Sluis, S.M.; Van Gerwen, R.; Gerrard, A.; Roberti, F.; Broeze, J.; Lukasse, L.; Wictor, E.; Oskam, G.; Bouazzaoui, S.; Infante Feirreira, C.A.; Langreck, J.; Gerritsen, J.; Bakker, R.; Uges, P.G.H.; Buitenhuis, H.; Havenaar, D.; Kwakman, N.; Jans, R.

    2008-11-15

    In 21 short and longer articles attention is paid to the use of natural refrigerants as a substitute for current refrigerants. [Dutch] In 21 korte en langere artikelen wordt in dit nummer aandacht besteed aan de toepassing van natuurlijke koudemiddelen als vervanging van de huidige in gebruik zijnde koudemiddelen.

  3. 7 CFR 58.154 - Refrigerated storage.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Refrigerated storage. 58.154 Section 58.154 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... § 58.154 Refrigerated storage. Finished product in containers subject to such conditions that will...

  4. ENERGY STAR Certified Commercial Refrigerators and Freezers

    Science.gov (United States)

    Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Commercial Refrigerators and Freezers that are effective as of October 1, 2014. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=commer_refrig.pr_crit_commercial_refrigerators

  5. On-line Monitoring Device for High-voltage Switch Cabinet Partial Discharge Based on Pulse Current Method

    Science.gov (United States)

    Y Tao, S.; Zhang, X. Z.; Cai, H. W.; Li, P.; Feng, Y.; Zhang, T. C.; Li, J.; Wang, W. S.; Zhang, X. K.

    2017-12-01

    The pulse current method for partial discharge detection is generally applied in type testing and other off-line tests of electrical equipment at delivery. After intensive analysis of the present situation and existing problems of partial discharge detection in switch cabinets, this paper designed the circuit principle and signal extraction method for partial discharge on-line detection based on a high-voltage presence indicating systems (VPIS), established a high voltage switch cabinet partial discharge on-line detection circuit based on the pulse current method, developed background software integrated with real-time monitoring, judging and analyzing functions, carried out a real discharge simulation test on a real-type partial discharge defect simulation platform of a 10KV switch cabinet, and verified the sensitivity and validity of the high-voltage switch cabinet partial discharge on-line monitoring device based on the pulse current method. The study presented in this paper is of great significance for switch cabinet maintenance and theoretical study on pulse current method on-line detection, and has provided a good implementation method for partial discharge on-line monitoring devices for 10KV distribution network equipment.

  6. Density, distribution, and genetic structure of grizzly bears in the Cabinet-Yaak Ecosystem

    Science.gov (United States)

    Macleod, Amy C.; Boyd, Kristina L; Boulanger, John; Royle, J. Andrew; Kasworm, Wayne F.; Paetkau, David; Proctor, Michael F; Annis, Kim; Graves, Tabitha A.

    2016-01-01

    The conservation status of the 2 threatened grizzly bear (Ursus arctos) populations in the Cabinet-Yaak Ecosystem (CYE) of northern Montana and Idaho had remained unchanged since designation in 1975; however, the current demographic status of these populations was uncertain. No rigorous data on population density and distribution or analysis of recent population genetic structure were available to measure the effectiveness of conservation efforts. We used genetic detection data from hair corral, bear rub, and opportunistic sampling in traditional and spatial capture–recapture models to generate estimates of abundance and density of grizzly bears in the CYE. We calculated mean bear residency on our sampling grid from telemetry data using Huggins and Pledger models to estimate the average number of bears present and to correct our superpopulation estimates for lack of geographic closure. Estimated grizzly bear abundance (all sex and age classes) in the CYE in 2012 was 48–50 bears, approximately half the population recovery goal. Grizzly bear density in the CYE (4.3–4.5 grizzly bears/1,000 km2) was among the lowest of interior North American populations. The sizes of the Cabinet (n = 22–24) and Yaak (n = 18–22) populations were similar. Spatial models produced similar estimates of abundance and density with comparable precision without requiring radio-telemetry data to address assumptions of geographic closure. The 2 populations in the CYE were demographically and reproductively isolated from each other and the Cabinet population was highly inbred. With parentage analysis, we documented natural migrants to the Cabinet and Yaak populations by bears born to parents in the Selkirk and Northern Continental Divide populations. These events supported data from other sources suggesting that the expansion of neighboring populations may eventually help sustain the CYE populations. However, the small size, isolation, and inbreeding documented by this study

  7. Review of investigations in eco-friendly thermoacoustic refrigeration system

    Directory of Open Access Journals (Sweden)

    Raut Ashish S.

    2017-01-01

    Full Text Available To reduce greenhouse gas emissions, internationally research and development is intended to improve the performance of conventional refrigeration system also growth of new-fangled refrigeration technology of potentially much lesser ecological impact. This paper gives brief review of research and development in thermoacoustic refrigeration also the existing situation of thermoacoustic refrigeration system. Thermoacoustic refrigerator is a novel sort of energy conversion equipment which converts acoustic power into heat energy by thermoacoustic effect. Thermoacoustic refrigeration is an emergent refrigeration technology in which there are no moving elements or any environmentally injurious refrigerants during its working. The concept of thermoacoustic refrigeration system is explained, the growth of thermoacoustic refrigeration, various investigations into thermoacoustic refrigeration system, various optimization techniques to improve coefficient of performance, different stacks and resonator tube designs to improve heat transfer rate, various gases, and other parameters like sound generation have been reviewed.

  8. Oil cooled, hermetic refrigerant compressor

    Science.gov (United States)

    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.

  9. Thermofluid Analysis of Magnetocaloric Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Gluesenkamp, Kyle R [ORNL; Vineyard, Edward Allan [ORNL; Benedict, Michael [GE Appliances

    2014-01-01

    While there have been extensive studies on thermofluid characteristics of different magnetocaloric refrigeration systems, a conclusive optimization study using non-dimensional parameters which can be applied to a generic system has not been reported yet. In this study, a numerical model has been developed for optimization of active magnetic refrigerator (AMR). This model is computationally efficient and robust, making it appropriate for running the thousands of simulations required for parametric study and optimization. The governing equations have been non-dimensionalized and numerically solved using finite difference method. A parametric study on a wide range of non-dimensional numbers has been performed. While the goal of AMR systems is to improve the performance of competitive parameters including COP, cooling capacity and temperature span, new parameters called AMR performance index-1 have been introduced in order to perform multi objective optimization and simultaneously exploit all these parameters. The multi-objective optimization is carried out for a wide range of the non-dimensional parameters. The results of this study will provide general guidelines for designing high performance AMR systems.

  10. Novel materials for laser refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Hehlen, Markus P [Los Alamos National Laboratory

    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.

  11. A review of carbon dioxide as a refrigerant in refrigeration technology

    Directory of Open Access Journals (Sweden)

    Paul Maina

    2015-09-01

    Full Text Available Tough environmental laws and stringent government policies have revolutionised the refrigeration sector, especially concerning the cycle fluid known as the refrigerant. It has been observed that only natural refrigerants are environmentally benign. When other refrigerant qualities are considered, especially those relating to toxicity and flammability, carbon dioxide emerges as the best among the natural refrigerants. However, carbon dioxide based refrigerants are not without drawbacks. Even though the use of R744 a carbon dioxide based refrigerant gas has solved the direct effect of emissions on the environment, studies to investigate the indirect effects of these systems are needed. Improvement in existing technical solutions and the formulation of additional solutions to existing R744 refrigeration problems is paramount if this technology is to be accepted by all, especially in areas with warm climates. National policies geared to green technologies are important to clear the way and provide support for these technologies. It is clear that carbon dioxide is one of the best refrigerants and as environmental regulations become more intense, it will be the ultimate refrigerant of the future.

  12. CABINETS OPERATING RULES AND COALITIONN FORMATION IN CENTRAL AND EASTERN EUROPE

    Directory of Open Access Journals (Sweden)

    DANA IRINA IONITA

    2011-04-01

    Full Text Available After the fall of communism in the late ’80 in Central and Eastern Europe, due to the appearance of several political parties in each state, there was the need to form coalitions in order to provide support for the governments. This paper aims to identify the institutional features that influence the coalition formation process using the rational choice institutionalism approach. In this case, the political parties, who seek to optimize their benefits in the government formation process, are constrained by the institutional environment. The institutional environment comprises the rules that determine how the governments are formed. Particularly, this paper aim is to identify how the cabinet operating rules affect the outcomes of the coalition formation process. In order to do so, I will develop a quantitative analysis of 110 cabinets in Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Slovenia, Romania and Bulgaria formed after the first free elections subsequent to the communist fall until the beginning of 2010. These countries represent the post-communist states that joined the European Union, finalizing the democratization process at least from a formal point a view. This cross-country comparison tries to explain how some institutional features influence the formation of coalitions in new democracies. This research is valuable due to the lack of this type of comparative studies on Central and Eastern European states.

  13. Recent advances of rearing cabinet instrumentation and control system for insect stock culture

    Science.gov (United States)

    Hermawan, Wawan; Kasmara, Hikmat; Melanie, Panatarani, Camellia; Joni, I. Made

    2017-01-01

    Helicoverpa armigera (Hubner) is one of a serious pest of horticulture in Indonesia. Helicoverpa armigera Nuclear Polyhedrovirus (HaNPV) has attracted interest for many researchers as a pest control for larvae of this species. Currently, we investigating the agrochemical formulations of HaNPV by introducing nanotechnology. Thus it is required an acceptable efficiency of insect stock cultures equipped with advance instruments to resolve the difficulties on insect stock seasons dependency. In addition, it is important to improve the insect survival with the aid of artificial natural environment and gain high insect production. This paper reports the rearing cabinet used as preparation of stock culture includes air-conditioning system, lighting, i.e. day and night control, and the main principles on recent technical and procedural advances apparatus of the system. The rearing system was moveable, designed and build by allowing air-conditioned cabinet for rearing insects, air motion and distribution as well as temperature and humidity being precisely controlled. The air was heated, humidified, and dehumidified respectively using a heater and ultrasonic nebulizer as actuators. Temperature and humidity can be controlled at any desired levels from room temperature (20°C) to 40 ± 1°C and from 0 to 80% RH with an accuracy of ±3% R.H. It is concluded that the recent design has acceptable performance based on the defined requirement for insect rearing and storage.

  14. Le contrôle des infections au cabinet du pédiatre

    Science.gov (United States)

    2008-01-01

    RÉSUMÉ La transmission des infections au cabinet du pédiatre est de plus en plus préoccupante. Le présent document expose les voies de transmission des infections et les principes sous-jacents aux mesures actuelles pour contrôler les infections. Pour prévenir les infections, il faut bien concevoir le cabinet et adopter des politiques administratives et de triage convenables, de même que des pratiques de base pour les soins de tous les patients (p. ex., hygiène des mains, port de gants, de masques, de lunettes de protection et d’une blouse d’hôpital pour des interventions précises; nettoyage, désinfection et stérilisation convenables des surfaces et du matériel, y compris les jouets, et techniques d’asepsie en cas d’interventions effractives) et des précautions additionnelles en cas d’infections précises. Le personnel doit avoir reçu les vaccins pertinents, et les personnes infectées doivent respecter les politiques de restriction au travail.

  15. Universal Numeric Segmented Display

    OpenAIRE

    Azad, Md. Abul Kalam; Sharmeen, Rezwana; S. M. Kamruzzaman

    2010-01-01

    Segmentation display plays a vital role to display numerals. But in today's world matrix display is also used in displaying numerals. Because numerals has lots of curve edges which is better supported by matrix display. But as matrix display is costly and complex to implement and also needs more memory, segment display is generally used to display numerals. But as there is yet no proposed compact display architecture to display multiple language numerals at a time, this paper proposes uniform...

  16. 46 CFR 111.79-15 - Receptacles for refrigerated containers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Receptacles for refrigerated containers. 111.79-15... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Receptacles § 111.79-15 Receptacles for refrigerated containers. Receptacles for refrigerated containers must meet one of the following: (a) Each receptacle for refrigerated...

  17. 46 CFR 151.40-11 - Refrigeration systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigeration systems. 151.40-11 Section 151.40-11... Refrigeration systems. (a) Boiloff systems. The venting of cargo boiloff to atmosphere shall not be used as a...) Vapor compression, tank refrigeration, and secondary refrigeration systems: The required cooling...

  18. 46 CFR 98.25-35 - Refrigerated systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Refrigerated systems. 98.25-35 Section 98.25-35 Shipping... § 98.25-35 Refrigerated systems. (a) Where refrigerated systems are installed to maintain the... acting as a stand-by unit. (c) Refrigerated tanks shall be insulated in conformance with the requirements...

  19. Ferroelectric Stirling-Cycle Refrigerator

    Science.gov (United States)

    Jalink, Antony, Jr. (Inventor); Hellbaum, Richard F. (Inventor); Rohrbach, Wayne W. (Inventor)

    1999-01-01

    A Stirling-cycle refrigerator has a three-pump configuration and pumping sequence, in which one pump serves as a compressor. one pump serves as an expander, and one pump serves as a displacer. The pumps are ferroelectrically actuated diaphragm pumps which are coordinated by synchronizing the ferroelectric-actuator voltages in such a way that the net effect of the displacer is to reduce the deleterious effect of dead space; that is, to circulate a greater fraction of the working fluid through the heat exchangers than would be possible by use of the compressor and expander alone. In addition. the displacer can be controlled separately to make the flow of working fluid in the heat exchangers turbulent (to increase the rate of transfer of heat at the cost of greater resistance to flow) or laminar (to decrease the resistance to flow at the cost of a lower heat-transfer rate).

  20. PIPER Continuous Adiabatic Demagnetization Refrigerator

    Science.gov (United States)

    Kimball, Mark O.; Shirron, Peter J.; Canavan, Edgar R.; James, Bryan L.; Sampson, Michael A.; Letmate, Richard V.

    2017-01-01

    We report upon the development and testing of a 4-stage adiabatic demagnetization refrigerator (ADR) capable of continuous cooling at 0.100 Kelvin. This cooler is being built to cool the detector array aboard NASA's Primordial Inflation Polarization Explorer (PIPER) observatory. The goal of this balloon mission is to measure the primordial gravitational waves that should exist if the theory of cosmological inflation is correct. At altitude, the ADR will hold the array of transition-edge sensors at 100 mK continuously while periodically rejecting heat to a 1.2 K pumped helium bath. During testing on ground, the array is held at the same temperature but heat is rejected to a 4.2 K helium bath indicating the flexibility in this coolers design.

  1. A versatile magnetic refrigeration test device

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Petersen, Thomas Frank; Pryds, Nini

    2008-01-01

    A magnetic refrigeration test device has been built and tested. The device allows variation and control of many important experimental parameters, such as the type of heat transfer fluid, the movement of the heat transfer fluid, the timing of the refrigeration cycle, and the magnitude...... of the applied magnetic field. An advanced two-dimensional numerical model has previously been implemented in order to help in the optimization of the design of a refrigeration test device. Qualitative agreement between the results from model and the experimental results is demonstrated for each of the four...

  2. Mathematical analysis of a Vuilleumier refrigerator.

    Science.gov (United States)

    Sherman, A.

    1971-01-01

    A comprehensive analysis of the Vuilleumier refrigerator was conducted. This analysis includes the effects of nonisothermal gas heat addition and rejection, hot and cold regenerator inefficiencies, conduction losses, and gas leakage losses. A computer program was written which solves the equations resulting from the analysis. The program calculates internal pressures, temperatures, and gas flow rates as functions of refrigerator crank angle, as well as overall refrigerator cooling load and power input. Comparisons between the program results and available data show good agreement, with a marked improvement over the predictions of the ideal model.

  3. Two-phase flow in refrigeration systems

    CERN Document Server

    Gu, Junjie; Gan, Zhongxue

    2013-01-01

    Two-Phase Flow in Refrigeration Systems presents recent developments from the authors' extensive research programs on two-phase flow in refrigeration systems. This book covers advanced mass and heat transfer and vapor compression refrigeration systems and shows how the performance of an automotive air-conditioning system is affected through results obtained experimentally and theoretically, specifically with consideration of two-phase flow and oil concentration. The book is ideal for university postgraduate students as a textbook, researchers and professors as an academic reference book, and b

  4. A Ross-Stirling spacecraft refrigerator

    Science.gov (United States)

    Walker, G.; Scott, M.; Zylstra, S.

    A spacecraft refrigerator was investigated capable of providing cooling for storage of food and biological samples in the temperature range 0-20 F with cooling capacity in the range of 1 to 2 kW, operating for long periods with great reliability. The system operated on the Stirling refrigeration cycle using the spacecraft life-support gases as the working fluid. A prototype spacecraft Stirling refrigerator was designed, built, and tested with air as the working fluid. The system performance was satisfactory, meeting the requirements specified above. Potential applications for the prototype unit are mentioned.

  5. Refrigerant charge management in a heat pump water heater

    Science.gov (United States)

    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.

  6. Commercial refrigeration: bet on green fluids; Refrigeration commerciale: pari sur les fluides verts

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-08-01

    Thanks to the collaboration between the user (Carrefour supermarkets), the fitter (CEF Nord) and the material manufacturer (Heatcraft Refrigeration), the new Carrefour supermarket of Collegien (Paris region, France) uses CO{sub 2} (R-744) as refrigerating fluid for the negative temperature refrigeration and ice slurries production units for the positive temperature cooling of 6100 m{sup 2} of fresh products. The new installation requires less refrigerating fluid and less maintenance than a classical direct expansion system. The ice slurry system allows to save 15 to 30% of electric power. Short paper. (J.S.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Pradeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Vineyard, Edward Allan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2012-07-19

    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.

  8. Compressor Properties in Sucking Two Phase Refrigerant

    Science.gov (United States)

    Inoue, Seiji; Nakayama, Masahiro; Matsuoka, Fumio

    A simulation model is proposed to analyze refrigerant properties in suction,compression and discharge process in rotary compressors,and compressor performance is analyzed by the calculations and the experiments in this paper. Heat transfer coefficients between the cylinder and refrigerant both in sucking two phase and superheated gas refrigerant have been evaluated by the calculations performed under the condition of the experiments since the validity of the simulation model has been proved by the agreement of the calculation results with the experimental ones. Linear relationship of discharge and cylinder temperature to compressor frequency and suction quality has been clarified by the experimental results. Mechanisms of the compressor performance have also analyzed by the refrigerant properties in the compression mechanism calculated every angle of the rolling piston in detail.

  9. Designing a magnet for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

    This thesis investigates the design and optimization of a permanent magnet assembly for use in a magnetic refrigeration device. The heart of magnetic refrigeration is the adiabatic temperature change in the magnetocaloric material which is caused by the magnetic field. In order to design an ideal...... magnet assembly the magnetocaloric materials and the refrigeration process itself and their properties and performance as a function of magnetic field are investigated. For the magnetocaloric materials it is the magnetization, specific heat capacity and adiabatic temperature that are investigated...... as functions of the magnetic field. Following this the process utilized by a magnetic refrigerator to provide cooling is investigated using a publicly available one dimensional numerical model. This process is called active magnetic regeneration (AMR). The aim is to determine the performance of the AMR...

  10. Modelling refrigerant distribution in microchannel evaporators

    DEFF Research Database (Denmark)

    Brix, Wiebke; Kærn, Martin Ryhl; Elmegaard, Brian

    2009-01-01

    The effects of refrigerant maldistribution in parallel evaporator channels on the heat exchanger performance are investigated numerically. For this purpose a 1D steady state model of refrigerant R134a evaporating in a microchannel tube is built and validated against other evaporator models. A stu...... out of the evaporator is kept constant. It is shown that the cooling capacity of the evaporator is reduced significantly, both in the case of unevenly distributed inlet quality and for the case of non-uniform airflow on the outside of the channels.......The effects of refrigerant maldistribution in parallel evaporator channels on the heat exchanger performance are investigated numerically. For this purpose a 1D steady state model of refrigerant R134a evaporating in a microchannel tube is built and validated against other evaporator models. A study...

  11. Enclosure for thermoelectric refrigerator and method

    Science.gov (United States)

    Park, Brian V. (Inventor); McGrath, Ralph D. (Inventor)

    1997-01-01

    An enclosed structure is provided for use with a refrigerator having a door assembly. The enclosed structure preferably contains superinsulation materials and a plurality of matching drawers. The enclosed structure preferably includes corner joints which minimize thermal energy transfer between adjacent superinsulation panels. The refrigerator may include a cooling system having a thermoelectric device for maintaining the temperature within the refrigerator at selected values. If desired, a fluid cooling system and an active gasket may also be provided between the door assembly and the enclosed structure. The fluid cooling system preferably includes a second thermoelectric device to maintain the temperature of fluid flowing through the active gasket at a selected value. The drawers associated with the refrigerator may be used for gathering, processing, shipping and storing food or other perishable items.

  12. REFRIGERATION ESPECIALLY FOR VERY LOW TEMPERATURES

    Science.gov (United States)

    Kennedy, P.B.; Smith, H.R. Jr.

    1960-09-13

    A refrigeration system for producing very low temperatures is described. The system of the invention employs a binary mixture refrigerant in a closed constant volume, e.g., Freon and ethylene. Such mixture is compressed in the gaseous state and is then separated in a fractionating column element of the system. Thenceforth, the first liquid to separate is employed stagewise to cool and liq uefy successive portions of the refrigerant at successively lower temperatures by means of heat exchangers coupled between the successive stages. When shut down, all of the volumes of the system are interconnected and a portion of the refrigerant remains liquid at ambient temperatures so that no dangerous overpressures develop. The system is therefore rugged, simple and dependable in operation.

  13. COMPUTER SIMULATION OF A STIRLING REFRIGERATING MACHINE

    Directory of Open Access Journals (Sweden)

    V.V. Trandafilov

    2015-10-01

    Full Text Available In present numerical research, the mathematical model for precise performance simulation and detailed behavior of Stirling refrigerating machine is considered. The mathematical model for alpha Stirling refrigerating machine with helium as the working fluid will be useful in optimization of these machines mechanical design. Complete non-linear mathematical model of the machine, including thermodynamics of helium, and heat transfer from the walls, as well as heat transfer and gas resistance in the regenerator is developed. Non-dimensional groups are derived, and the mathematical model is numerically solved. Important design parameters are varied and their effect on Stirling refrigerating machine performance determined. The simulation results of Stirling refrigerating machine which include heat transfer and coefficient of performance are presented.

  14. Shuttle Kit Freezer Refrigeration Unit Conceptual Design

    Science.gov (United States)

    Copeland, R. J.

    1975-01-01

    The refrigerated food/medical sample storage compartment as a kit to the space shuttle orbiter is examined. To maintain the -10 F in the freezer kit, an active refrigeration unit is required, and an air cooled Stirling Cycle refrigerator was selected. The freezer kit contains two subsystems, the refrigeration unit, and the storage volume. The freezer must provide two basic capabilities in one unit. One requirement is to store 215 lbs of food which is consumed in a 30-day period by 7 people. The other requirement is to store 128.3 lbs of medical samples consisting of both urine and feces. The unit can be mounted on the lower deck of the shuttle cabin, and will occupy four standard payload module compartments on the forward bulkhead. The freezer contains four storage compartments.

  15. ENERGY STAR Certified Commercial Refrigerators and Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Commercial Refrigerators and Freezers that are...

  16. ENERGY STAR Laboratory Grade Refrigerators and Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1 ENERGY STAR Program Requirements for Laboratory Grade Refrigerators and Freezers that...

  17. Positive Displacement Compressor Technology for Refrigeration

    Science.gov (United States)

    Nagatomo, Shigemi

    Trends of compressor technologies for refrigerators, freezers and condensing units are presented in this paper. HFC refrigerants such as R134a and R404C are promising candidates as an altemative for R12. Performance of reciprocating and rotary compressors in the operation with R134A is described. In addition, compressor technologies such as efficiency improvement are described in the cases of reciprocating, rotary and scroll compressors.

  18. Active Sensor Configuration Validation for Refrigeration Systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Blanke, Mogens; Niemann, Hans Henrik

    2010-01-01

    Major faults in the commissioning phase of refrigeration systems are caused by defects related to sensors. With a number of similar sensors available that do not differ by type but only by spatial location in the plant, interchange of sensors is a common defect. With sensors being used quite...... identify the sensor configuration. The method as such is generic and is shown in the paper to work convincingly on refrigeration systems with significant nonlinear behaviors...

  19. Combined cold compressor/ejector helium refrigerator

    Science.gov (United States)

    Brown, Donald P.

    1985-01-01

    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.

  20. Touching Anatomy. : On the Handling of Anatomical Preparations in the Anatomical Cabinets of Frederik Ruysch (1638-1731)

    NARCIS (Netherlands)

    Knoeff, Rina

    2015-01-01

    This paper argues that the anatomical Cabinets of Dutch anatomist Frederik Ruysch must be understood as an early modern workshop in which preparations were continuously handled. It is claimed that preparations actively appealed to anatomists and visitors to handle, re-dissect, touch, and even kiss

  1. Hardwood lumber widths and grades used by the furniture and cabinet industries: Results of a 14-mill survey

    Science.gov (United States)

    Jan Wiedenbeck; John Brown; Neal Bennett; Everette Rast

    2003-01-01

    Data on red oak lumber width, length, and grade were collected at 14 furniture and cabinet industry rough mills to identify relationships among these lumber attributes and the degree to which they differ from mill to mill. Also, this information is needed to formulate valid lumber size distributions that will improve the quality of theresults obtained in mill and...

  2. Solar thermal drying of apricots: Effect of spectrally-selective cabinet materials on drying rate and quality metrics (abstract)

    Science.gov (United States)

    Solar thermal (ST) drying is currently not in widespread commercial use due to concerns about slow drying rates and poor product quality. ST dryer cabinets could be constructed from spectrally-selective materials (materials which transmit only certain sunlight wavelength bands), but these types of ...

  3. Door and cabinet recognition using convolutional neural nets and real-time method fusion for handle detection and grasping

    DEFF Research Database (Denmark)

    Maurin, Adrian Llopart; Ravn, Ole; Andersen, Nils Axel

    2017-01-01

    In this paper we present a new method that robustly identifies doors, cabinets and their respective handles, with special emphasis on extracting useful features from handles to be then manipulated. The novelty of this system relies on the combination of a Convolutional Neural Net (CNN), as a form...

  4. Refrigerant saving automotive air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Muso, M.; Kitahara, Y. (Hitachi, Ltd., Tokyo (Japan))

    1990-06-01

    Based on the phaseout schedule of harmful fleons controlled in the Montreal Protocl, as the first step to alter them into harmless ones, the reduction of fleon consumption was attempted for automotive air-conditioning systems. As saving measures against refrigerant, the following methods were pursued: (1) the volume reduction of air conditioner elements, such as the use of thin pipes, (2) the improvement of liquid and gas secession to reduce a refrigerant weight in a receiver-drier, (3) the reduction of refrigerant leakage from flexible hoses or compressor seals, and (4) more precise determination of a suitable refrigerant weight, such as the adoption of narrower weight tolerance. The low-permeable flexible hose with an inner thin nylon tube was developed, and a suitable refrigerant weight was determined from a register discharge air temperature, and furthermore, the tolerance was narrowed from {plus minus} 0.1kg to {plus minus} 0.05kg. As a result, required refrigerant was successfully reduced by 31-35%. 2 refs., 6 figs., 2 tabs.

  5. Air flow optimization for energy efficient blower of biosafety cabinet class II A2

    Science.gov (United States)

    Ibrahim, M. D.; Mohtar, M. Z.; Alias, A. A.; Wong, L. K.; Yunos, Y. S.; Rahman, M. R. A.; Zulkharnain, A.; Tan, C. S.; Thayan, R.

    2017-04-01

    An energy efficient Biosafety Cabinet (BSC) has become a big challenge for manufacturers to develop BSC with the highest level of protection. The objective of research is to increase air flow velocity discharge from centrifugal blower. An aerodynamic duct shape inspired by the shape of Peregrine Falcon’s wing during diving flight is added to the end of the centrifugal blower. Investigation of air movement is determined by computational fluid dynamics (CFD) simulation. The results showed that air velocity can be increased by double compared to typical manufactured BSC and no air recirculation. As conclusion, a novel design of aerodynamic duct shape successfully developed and proved that air velocity can be increase naturally with same impeller speed. It can contribute in increasing energy efficiency of the centrifugal blower. It is vital to BSC manufacturer and can be apply to Heating, Air Ventilation and Air Conditioning (HVAC) industries.

  6. United Kingdom security policy during the Blair Cabinet (1997-2007

    Directory of Open Access Journals (Sweden)

    Oana Elena Brânda

    2012-08-01

    Full Text Available The United Kingdom’s security policy between 1997-2007, the time when Tony Blair���s Labour dominated the Cabinet, cannot be easily distinguished from the foreign policy. The two are strategically combined and are the responsibility of so many institutions that one finds it difficult to assess them. However, as the period is dominated by the 9/11 attacks and the military interventions in Afghanistan and Iraq, the British defense policy is unitarily centered on the threat of terrorism and weapons of mass destruction. Despite the many holders of decision-making power, it appears that the instruments to be used in achieving a state of comfort on a security level are mainly documents that are to become the basis of further action.

  7. Control of accidental releases of hydrogen selenide in vented storage cabinets

    Science.gov (United States)

    Fthenakis, V. M.; Moskowitz, P. D.; Sproull, R. D.

    1988-07-01

    Highly toxic hydrogen selenide and hydrogen sulfide gases are used in the production of copper-indium-diselenide photovoltaic cells by reactive sputtering. In the event of an accident, these gases may be released to the atmosphere and pose hazards to public and occupational safety and health. This paper outlines an approach for designing systems for the control of these releases given the uncertainty in release conditions and lack of data on the chemical systems involved. Accidental releases of these gases in storage cabinets can be controlled by either a venturi and packed-bed scrubber and carbon adsorption bed, or containment scrubbing equipment followed by carbon adsorption. These systems can effectively reduce toxic gas emissions to levels needed to protect public health. The costs of these controls (˜0.012/Wp) are samll in comparison with current (˜6/Wp) and projected (˜I/Wp) production costs.

  8. Meeting Summary of Kitchen Cabinet on Financial Due Diligence to Reduce Proliferation Risks

    Energy Technology Data Exchange (ETDEWEB)

    Hund, Gretchen [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weise, Rachel A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Carr, Geoffrey A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-15

    The U.S. Department of Energy’s Pacific Northwest National Laboratory convened the Kitchen Cabinet (KC) to facilitate a candid discussion about the role of financial institutions (FIs) in antiproliferation efforts to reduce nuclear proliferation risks by identifying suspicious business transactions and exports when making lending or insurance decisions. The meeting brought together a group of export control specialists, largely representatives from the Nuclear Suppliers Group (NSG) Participating Governments (PGs) and finance experts representing banks and insurance companies. By assembling a KC of experts, the group could understand what suspicious transactions look like from each other’s perspectives and better inform each of their operations. The goal was to develop red flags FIs could use to identify suspicious proliferation-related transactions and to help governments gain a clearer picture of proliferation using financial information.

  9. Self-sustained cabinet based on fuel cell technology and solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Rafael Augusto de Oliveira; Valentim, Rafael Bertier; Glir, Joao Raphael Zanlorensi; Stall, Alexandre; Sommer, Elise Meister; Sanches, Luciana Schimidilin; Dias, Fernando Gallego; Korndorfer, Heitor Medeiros de Albuquerque; Vargas, Jose Viriato Coelho [Universidade Federal do Parana (DEMEC/UFPR), Curitiba, PR (Brazil). Dept. de Engenharia Mecanica], Email: rafaelcorrea123@hotmail.com; Ordonez, Juan Carlos [Florida State University, Tallahasse, Florida (United States). Dept. of Mechanical Engineering. Center for Advanced Power Systems

    2010-07-01

    Along the past few years, there has been intensive research on clean and renewable energy production. Two main reasons have been pointed out: pollution caused by oil based fuels consumption and their availability diminution, which increases their production costs. Fuel Cells have shown to be a clean and renewable energy source, which reveals them as a promising solution, although their technology needs further development. Fuel Cells produce electricity, water and heat consuming hydrogen and oxygen, this provided pure or from a natural air source. Present research has combined different equipment to compose a self-sustaining fuel cells technology based cabinet for energy production, which is a Regenerative Fuel Cell System (RFC). This system contains: fuel cells stack, electrolyzer, photovoltaic panel, batteries, current inverter and a charge controller. Photovoltaic panel charges the batteries, while charge controller controls the batteries loading. Batteries are connected to an inverter which converts direct current into alternating current. Inverter is connected to an electrolyzer (Hogen GC 600) which splits the water molecule into hydrogen and oxygen molecules. Produced hydrogen supplies the fuel cell stack and the oxygen is released directly to the atmosphere. Fuel cell stacks power production is transformed into mechanical energy by a fan. Electrical power generated by Ballard stack is 5.124 W, with a voltage of 36.6 V and current of 0.14 A. The system proved to have a great efficiency and to be capable to assemble two renewable energy sources (solar and fuel cell technology) in a self-sustainable cabinet. It has also been shown that equipment such as Electrolyzer, Fuel Cell Stack and Photovoltaic panel can be fit together in the order to produce energy. Therefore, research on Fuel Cells Regenerative System reveals great importance for developing a new, clean, renewable and regenerative energy production system. (author)

  10. Reducing airborne pathogens, dust and Salmonella transmission in experimental hatching cabinets using an electrostatic space charge system.

    Science.gov (United States)

    Mitchell, B W; Buhr, R J; Berrang, M E; Bailey, J S; Cox, N A

    2002-01-01

    Electrostatic charging of particles in enclosed spaces has been shown to be an effective means of reducing airborne dust. Dust generated during the hatching process has been strongly implicated in Salmonella transmission, which complicates the cleaning and disinfecting processes for hatchers. Following two preliminary trials in which dust reduction was measured, four trials were conducted to evaluate the effectiveness of an electrostatic space charge system (ESCS) on the levels of total aerobic bacteria (TPC), enterobacteriaceae (ENT), and Salmonella within an experimental hatching cabinet. The ESCS was placed in a hatching cabinet that was approximately 50% full of 18-d-old broiler hatching eggs. The ESCS operated continuously to generate a strong negative electrostatic charge throughout the cabinet through hatching, and dust was collected in grounded trays containing water and a degreaser. An adjacent hatching cabinet served as an untreated control. Air samples from hatchers were collected daily, and sample chicks from each hatcher were grown out to 7 d of age for cecal analysis in three of the trials. The ESCS significantly (P < 0.05) reduced TPC and ENT by 85 to 93%. Dust concentration was significantly reduced (P < 0.0001) during the preliminary trials with an average reduction of 93.6%. The number of Salmonella per gram of cecal contents in birds grown to 7 d of age was significantly (P < 0.001) reduced by an average log10 3.4 cfu/g. This ionization technology is relatively inexpensive and could be used to reduce airborne bacteria and dust within the hatching cabinet.

  11. Efficacy of Two Cleaning Solutions for the Decontamination of 10 Antineoplastic Agents in the Biosafety Cabinets of a Hospital Pharmacy.

    Science.gov (United States)

    Anastasi, Marco; Rudaz, Serge; Queruau Lamerie, Thomas; Odou, Pascal; Bonnabry, Pascal; Fleury-Souverain, Sandrine

    2015-08-01

    This study aimed to evaluate two cleaning solutions for the chemical decontamination of antineoplastic agents on the surfaces of two biosafety cabinets routinely used for chemotherapy preparation in a hospital pharmacy. For almost 1 year (49 weeks), two different solutions were used for the weekly cleaning of two biosafety cabinets in a hospital pharmacy's centralized cytotoxic preparation unit. The solutions evaluated were a commercial solution of isopropyl alcohol (IPA) and water (70:30, vol:vol), and a detergent solution constituted by 10(-2)M of sodium dodecyl sulfate (SDS) with 20% IPA. Seven areas in each biosafety cabinet were wiped 14 times throughout the year, before and after the weekly cleaning process, according to a validated procedure. Samples were analyzed using a validated method of high-performance liquid chromatography coupled to mass spectrometry. The decontamination efficacy of these two solutions was tested for 10 antineoplastic agents: cytarabine, gemcitabine, methotrexate, etoposide phosphate, irinotecan, cyclophosphamide, ifosfamide, doxorubicin, epirubicin, and vincristine. Overall decontamination efficacies observed were 82±6% and 49±11% for SDS solution and IPA, respectively. Higher contamination levels were distributed on areas frequently touched by the pharmacy technicians-such as sleeves and airlock handles-than on scale plates, gravimetric control hardware, and work benches. Detected contaminations of cyclophosphamide, ifosfamide, gemcitabine, and cytarabine were higher than those of the others agents. SDS solution was almost 20% more efficient than IPA on eight of the antineoplastic agents. Both cleaning solutions were able to reduce contamination levels in the biosafety cabinets. The efficacy of the solution containing an anionic detergent agent (SDS) was shown to be generally higher than that of IPA and, after the SDS cleaning procedure, biosafety cabinets demonstrated acceptable contamination levels. © The Author 2015

  12. Review of magnetic refrigeration system as alternative to conventional refrigeration system

    Science.gov (United States)

    Mezaal, N. A.; Osintsev, K. V.; Zhirgalova, T. B.

    2017-10-01

    The refrigeration system is one of the most important systems in industry. Developers are constantly seeking for how to avoid the damage to the environment. Magnetic refrigeration is an emerging, environment-friendly technology based on a magnetic solid that acts as a refrigerant by magneto-caloric effect (MCE). In the case of ferromagnetic materials, MCE warms as the magnetic moments of the atom are aligned by the application of a magnetic field. There are two types of magnetic phase changes that may occur at the Curie point: first order magnetic transition (FOMT) and second order magnetic transition (SOMT). The reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative cycle), where the magnetic material matrix works both as a refrigerating medium and as a heat regenerating medium, while the fluid flowing in the porous matrix works as a heat transfer medium. Regeneration can be accomplished by blowing a heat transfer fluid in a reciprocating fashion through the regenerator made of magnetocaloric material that is alternately magnetized and demagnetized. Many magnetic refrigeration prototypes with different designs and software models have been built in different parts of the world. In this paper, the authors try to shed light on the magnetic refrigeration and show its effectiveness compared with conventional refrigeration methods.

  13. COMPARISON OF ENERGY AND EXERGY EFFICIENCIES OF ABSORPTION REFRIGERATION SYSTEM WITH MECHANICAL COMPRESSION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Gülay YAKAR

    2005-02-01

    Full Text Available In this study, energy and exergy analysis of absorption refrigeration system using LiBr- water and mechanical compression refrigeration system using R134-a were performed at different evaporation temperatures. The results are presented in tables and figures.

  14. Properties of Gas Mixtures and Their Use in Mixed-Refrigerant Joule-Thomson Refrigerators

    Science.gov (United States)

    Luo, E.; Gong, M.; Wu, J.; Zhou, Y.

    2004-06-01

    The Joule-Thomson (J-T) effect has been widely used for achieving low temperatures. In the past few years, much progress has been made in better understanding the working mechanism of the refrigeration method and in developing prototypes for different applications. In this talk, there are three aspects of our research work to be discussed. First, some special thermal properties of the mixtures for achieving liquid nitrogen temperature range will be presented. Secondly, some important conclusions from the optimization of various mixed-refrigerant J-T cycles such as a simple J-T cycle and an auto-cascade mixed-refrigerant J-T cycle will be presented. Moreover, an auto-cascade, mixed-refrigerant J-T refrigerator with a special mixture capable of achieving about 50K will be mentioned. Finally, various prototypes based on the mixed-refrigerant refrigeration technology will be described. These applications include miniature J-T cryocoolers for cooling infrared detectors and high-temperature superconducting devices, cryosurgical knife for medical treatment, low-temperature refrigerators for biological storage and so forth. The on-going research work and unanswered questions for this technology will be also discussed.

  15. SIMULATION RESULTS OF SINGLE REFRIGERANTS FOR USE IN A DUAL-CIRCUIT REFRIGERATOR/FREEZER

    Science.gov (United States)

    The paper reviews the refrigerant/freezer (RF) design and refrigerant selection process that is necessary to design an energy efficient RF that does not use fully halogenated chlorofluorocarbons (CFCs). EPA is interested in phasing out CFCs in RFs to minimize stratospheric ozone ...

  16. 10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

    Science.gov (United States)

    2010-01-01

    ... vertical. Ice-cream freezer means a commercial freezer that is designed to operate at or below −5 °F (−21... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial refrigerators, freezers and refrigerator-freezers. 431.62 Section 431.62 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION...

  17. Low cost microminiature refrigerators for large unit volume applications

    Science.gov (United States)

    Duboc, R. M., Jr.

    1983-01-01

    Photolithographic techniques were employed to fabricate small Joule-Thomson refrigerators in laminated substrates. The gas passages of a J-T refrigerator are formed by etching channels as narrow as 50 microns and as shallow as 5 microns in glass plates which are laminated together. Circular refrigerators on the order of 1.5 centimeters in diameter and .75 millimeters thick were produced which cool down to cryogenic temperatures in a few seconds, using Argon or Nitrogen, with no vacuum or radiation insulation. Smaller refrigerators are developed for both faster cooldown and low refrigeration capacity applications. By using this technology, custom refrigerators can be designed to meet specific application requirements.

  18. Refrigerated Warehouse Demand Response Strategy Guide

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Doug [VaCom Technologies, San Luis Obispo, CA (United States); Castillo, Rafael [VaCom Technologies, San Luis Obispo, CA (United States); Larson, Kyle [VaCom Technologies, San Luis Obispo, CA (United States); Dobbs, Brian [VaCom Technologies, San Luis Obispo, CA (United States); Olsen, Daniel [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-11-01

    This guide summarizes demand response measures that can be implemented in refrigerated warehouses. In an appendix, it also addresses related energy efficiency opportunities. Reducing overall grid demand during peak periods and energy consumption has benefits for facility operators, grid operators, utility companies, and society. State wide demand response potential for the refrigerated warehouse sector in California is estimated to be over 22.1 Megawatts. Two categories of demand response strategies are described in this guide: load shifting and load shedding. Load shifting can be accomplished via pre-cooling, capacity limiting, and battery charger load management. Load shedding can be achieved by lighting reduction, demand defrost and defrost termination, infiltration reduction, and shutting down miscellaneous equipment. Estimation of the costs and benefits of demand response participation yields simple payback periods of 2-4 years. To improve demand response performance, it’s suggested to install air curtains and another form of infiltration barrier, such as a rollup door, for the passageways. Further modifications to increase efficiency of the refrigeration unit are also analyzed. A larger condenser can maintain the minimum saturated condensing temperature (SCT) for more hours of the day. Lowering the SCT reduces the compressor lift, which results in an overall increase in refrigeration system capacity and energy efficiency. Another way of saving energy in refrigerated warehouses is eliminating the use of under-floor resistance heaters. A more energy efficient alternative to resistance heaters is to utilize the heat that is being rejected from the condenser through a heat exchanger. These energy efficiency measures improve efficiency either by reducing the required electric energy input for the refrigeration system, by helping to curtail the refrigeration load on the system, or by reducing both the load and required energy input.

  19. A study of alternative refrigerants for the refrigeration and air conditioning sector in Mauritius

    Science.gov (United States)

    Dreepaul, R. K.

    2017-11-01

    The most frequently used refrigerants in the refrigeration and air conditioning (RAC) sector in Mauritius are currently hydrochlorofluorocarbons (HCFC) and hydrofluorocarbons (HFC). However, because of their strong influence on global warming and the impact of HCFCs on the ozone layer, refrigerants such as ammonia (NH3), carbon dioxide (CO2) and Hydrocarbons (HC), having minimal impact on the environment, are being considered. So far, HCs have only been safely used in domestic refrigeration. Ammonia has been used mainly for industrial refrigeration whereas CO2 is still under study. In this paper, a comparative study of the various feasible alternatives is presented in a survey that was undertaken with major stake holders in the field. The retrofitting possibility of existing equipment was assessed and safety issues associated with each refrigerant were analysed. The major setback of hydrocarbons as a widely accepted refrigerant is its flammability which was considered as a major safety hazard by the majority of respondents in the survey and the main advantages are the improved equipment coefficient of performance (COP) and better TEWI factor. This resulted in a 12 % drop in energy consumption. Despite the excellent thermodynamic properties of ammonia, its use has mainly been confined to industrial refrigeration due to its toxicity. In Mauritius, the performance of ammonia in air conditioning is being evaluated on a pilot basis. The major setback of carbon dioxide as a refrigerant is the high operating pressure which is considered a safety hazard. The high initial investment cost and the lack of qualified maintenance technician is also an issue. The use of CO2 is mainly being considered in the commercial refrigeration sector.

  20. Refrigeration systems with non-azeotropic refrigerant mixtures instead of CNC; Kaelteanlagen mit nichtazeotropen ZKM zur Abloesung der FCKW

    Energy Technology Data Exchange (ETDEWEB)

    Burandt, B.

    1992-10-14

    The use of non-azeotropic refrigerant mixtures in cooling and heat pump systems is energetically favourable. This was proved in process calculations with refrigerants and two-component refrigerant mixtures. The work helps to solve plant problems and shows ways for continuous concentration determination of non-azeotropic refrigerants as well as for the control of refrigeration system in which refrigerant mixtuers are used. (VT) [Deutsch] Die Anwendung nichtazeotroper Kaeltemittel in Kaelte und Waermepumpanlagen weist energetisch guenstigere Eigenschaften aus. Dies wurde durch Prozessberechnungen von Ein- und Zweistoffkaeltemitteln bestaetigt. Die Arbeit traegt zur Loesung anlagetechnischer Probleme und der kontinuierlichen Konzentrationsbestimmung von nichtazeotropen Kaeltemitteln sowie der Regelung von Kaelteanlagen mit Kaeltemitteln bei. (VT

  1. Quantum heat engines and refrigerators: continuous devices.

    Science.gov (United States)

    Kosloff, Ronnie; Levy, Amikam

    2014-01-01

    Quantum thermodynamics supplies a consistent description of quantum heat engines and refrigerators up to a single few-level system coupled to the environment. Once the environment is split into three (a hot, cold, and work reservoir), a heat engine can operate. The device converts the positive gain into power, with the gain 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 principles. Only a global description of the coupling of the device to the reservoirs is consistent with the first and second laws of thermodynamics. Optimization of the devices leads to a balanced set of parameters in which the couplings to the three reservoirs are of the same order and the external driving field is in resonance. When analyzing refrigerators, one needs to devote special attention to a dynamical version of the third law of thermodynamics. Bounds on the rate of cooling when Tc→0 are obtained by optimizing the cooling current. All refrigerators as Tc→0 show universal behavior. The dynamical version of the third law imposes restrictions on the scaling as Tc→0 of the relaxation rate γc and heat capacity cV of the cold bath.

  2. Quantum absorption refrigerator with trapped ions

    Science.gov (United States)

    Gan, Jaren; Maslennikov, Gleb; Hablützel Marrero, Roland; Ding, Shiqian; Nimmrichter, Stefan; Roulet, Alexandre; Dai, Jibo; Scarani, Valerio; Matsukevich, Dzmitry

    2017-04-01

    We report on an experimental realization of a quantum absorption refrigerator in a system of the three trapped 171Yb+ ions. The normal modes of motion are coupled by a trilinear Hamiltonian a† bc + h . c . and represent ``hot'', ``work'' and ``cold'' bodies of the refrigerator. We investigate the equilibrium properties of the refrigerator, and demonstrate the absorption refrigeration effect with the modes being prepared in thermal states. We also investigate the coherent dynamics and steady state properties of such a system away from equilibrium operation. We compare the cooling capabilities of thermal versus squeezed thermal states prepared in the work mode as a quantum resource for cooling. Finally, we exploit the coherent dynamics of the system and demonstrate single-shot cooling in the refrigerator. By stopping the evolution in the right moment, we show a significant advantage in cooling as compared to both the steady state and equilibrium performance. This research is supported by the National Research Foundation, Prime Minister's Office, Singapore and the Ministry of Education, Singapore under the Research Centres of Excellence programme.

  3. Data-Driven Control of Refrigeration System

    DEFF Research Database (Denmark)

    Vinther, Kasper

    Refrigeration is used in a wide range of applications, e.g., for storage of food at low temperatures to prolong shelf life and in air conditioning for occupancy comfort. The main focus of this thesis is control of supermarket refrigeration systems. This market is very competitive and it is import......Refrigeration is used in a wide range of applications, e.g., for storage of food at low temperatures to prolong shelf life and in air conditioning for occupancy comfort. The main focus of this thesis is control of supermarket refrigeration systems. This market is very competitive...... conditions make optimal tuning of controllers a difficult and time consuming task. These are also some of the challenges which make advanced model-based control difficult, and a model-based controller will often be tailored to a specific system. The focus in this thesis is therefore instead on development...... of data-driven control strategies with a higher plug and play potential. One of the main control challenges in refrigeration systems is proper control of superheat for efficient and safe operation of the system. This task can be performed by an electronic expansion valve and requires two sensors, which...

  4. Influence of Oil on Refrigerant Evaporator Performance

    Science.gov (United States)

    Kim, Jong-Soo; Nagata, Karsuya; Katsuta, Masafumi; Tomosugi, Hiroyuki; Kikuchi, Kouichiro; Horichi, Toshiaki

    In vapor compression refrigeration system using oil-lubricated compressors, some amount of oil is always circulated through the system. Oil circulation can have a significant influence on the evaporator performance of automotive air conditioner which is especially required to cool quickly the car interior after a period standing in the sun. An experimental investigation was carried out an electrically heated horizontal tube to measure local heat transfer coefficients for various flow rates and heat fluxes during forced convection boiling of pure refrigerant R12 and refrigerant-oil mixtures (0-11% oil concentration by weight) and the results were compared with oil free performance. Local heat transfer coefficients increased at the region of low vapor quality by the addition of oil. On the other hand, because the oil-rich liquid film was formed on the heat transfer surface, heat transfer coefficients gradually decreased as the vapor quality became higher. Average heat transfer coefficient reached a maximum at about 4% oil concentration and this trend agreed well with the results of Green and Furse. Previous correlations, using the properties of the refrigerant-oil mixture, could not predict satisfactorily the local heat transfer coefficients data. New correlation modified by oil concentration factor was developed for predicting the corresponding heat transfer coefficient for refrigerant-oil mixture convection boiling. The maximum percent deviation between predicted and measured heat transfer coefficient was within ±30%.

  5. Cool sound: the future of refrigeration? Thermodynamic and heat transfer issues in thermoacoustic refrigeration

    Science.gov (United States)

    Herman, C.; Travnicek, Z.

    2006-04-01

    During the past two decades the thermoacoustic refrigeration and prime mover cycles gained importance in a variety of refrigeration applications. Acoustic work, sound, can be used to generate temperature differences that allow the transport of heat from a low temperature reservoir to an ambient at higher temperature, thus forming a thermoacoustic refrigeration system. The thermoacoustic energy pumping cycle can also be reversed: temperature difference imposed along the stack plates can lead to sound generation. In this situation the thermoacoustic system operates as a prime mover. Sound generated by means of this thermoacoustic energy conversion process can be utilized to drive different types of refrigeration devices that require oscillatory flow for their operation, such as thermoacoustic refrigerators, pulse tubes and Stirling engines. In order for a thermoacoustic refrigeration or prime mover system as well as a thermoacoustic prime mover driving a non-thermoacoustic refrigeration system to be competitive on the current market, it has to be optimized in order to improve its overall performance. Optimization can involve improving the performance of the entire system as well as its components. The paper addresses some of the thermodynamic and heat transfer issues relevant in improving the performance of the thermoacoustic system, such as optimization for maximum COP, maximum cooling load and the role of the heat exchangers. Results obtained using the two optimization criteria are contrasted in the paper to illustrate the complexity of the optimization process.

  6. Performance characteristics of a quantum Diesel refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    He Jizhou [Department of Physics, Nanchang University, Nanchang 330031 (China)], E-mail: hjzhou@ncu.edu.cn; Wang Hao; Liu Sanqiu [Department of Physics, Nanchang University, Nanchang 330031 (China)

    2009-04-15

    The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed.

  7. Performance characteristics of a quantum Diesel refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    He, Jizhou; Wang, Hao; Liu, Sanqiu [Department of Physics, Nanchang University, Nanchang 330031 (China)

    2009-04-15

    The Diesel refrigeration cycle using an ideal quantum gas as the working substance is called quantum Diesel refrigeration cycle, which is different from Carnot, Ericsson, Brayton, Otto and Stirling refrigeration cycles. For ideal quantum gases, a corrected equation of state, which considers the quantum behavior of gas particles, is used instead of the classical one. The purpose of this paper is to investigate the effect of quantum gas as the working substance on the performance of a quantum Diesel refrigeration cycle. It is found that coefficients of performance of the cycle are not affected by the quantum degeneracy of the working substance, which is the same as that of the classical Diesel refrigeration cycle. However, the refrigeration load is different from those of the classical Diesel refrigeration cycle. Lastly, the influence of the quantum degeneracy on the performance characteristics of the quantum Diesel refrigeration cycle operated in different temperature regions is discussed. (author)

  8. A Cold Cycle Dilution Refrigerator for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The cold cycle dilution refrigerator is a continuous refrigerator capable of cooling to temperatures below 100 mK that makes use of a novel thermal magnetic pump....

  9. Simulation of absorption refrigeration system for automobile application

    Directory of Open Access Journals (Sweden)

    Ramanathan Anand

    2008-01-01

    Full Text Available An automotive air-conditioning system based on absorption refrigeration cycle has been simulated. This waste heat driven vapor absorption refrigeration system is one alternate to the currently used vapour compression refrigeration system for automotive air-conditioning. Performance analysis of vapor absorption refrigeration system has been done by developing a steady-state simulation model to find the limitation of the proposed system. The water-lithium bromide pair is used as a working mixture for its favorable thermodynamic and transport properties compared to the conventional refrigerants utilized in vapor compression refrigeration applications. The pump power required for the proposed vapor absorption refrigeration system was found lesser than the power required to operate the compressor used in the conventional vapor compression refrigeration system. A possible arrangement of the absorption system for automobile application is proposed.

  10. Retail Food Refrigeration and the Phaseout of HCFC-22

    Science.gov (United States)

    Provides information on the HCFC phaseout that is relevant to food retailers, including alternatives to the use of HCFC-22 in retail food refrigeration, other refrigerant regulations, and resources for more information.

  11. OPTIONS FOR REDUCING REFRIGERANT EMISSIONS FROM SUPERMARKET SYSTEMS

    Science.gov (United States)

    The report was prepared to assist personnel responsible for the design, construction, and maintenance of retail food refrigeration equipment in making knowledgeable decisions regarding the implementation of refrigerant-emissions-reducing practices and technologies. It characteriz...

  12. Transitioning to Low-GWP Alternatives in Transport Refrigeration

    Science.gov (United States)

    This fact sheet provides information on low-GWP refrigerant and foam blowing agent alternatives used in transport refrigeration equipment. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

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

    Science.gov (United States)

    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.

  14. Laser refrigeration of rare-earth doped sodium-yttrium-fluoride nanowires

    Science.gov (United States)

    Zhou, Xuezhe; Roder, Paden B.; Smith, Bennett E.; Pauzauskie, Peter J.

    2017-02-01

    Hexagonal sodium yttrium fluoride (β-NaYF4) crystals are currently being studied for a wide range of applications including color displays, solar cells, photocatalysis, and bio-imagβing. β-NaYF4 has also been predicted to be a promising host material for laser refrigeration of solids. However, due to challenges with growing Czochralski β- NaYF4 single-crystals, laser refrigeration of bulk β-NaYF4 has not yet been achieved6. Recently hydrothermal processing has been reported to produce Yb-doped β-NaYF4 nanowires (NWs) that undergo laser refrigeration during single-beam optical trapping experiments in heavy water. The local refrigeration of the individual nanowire is quantified through the analysis of its Brownian motion through the analysis of forward scattered light that is focused onto a quadrant photodiode. The individual β-NaYF4 nanowires show maximum local cooling of 9°C below ambient conditions. Here we present the emission lifetime for the 4S3/2 - 4I15/2 transition for Er(III) ions in Yb/Er-codoped -NaYF4 NW ensembles was measured to be (220 +/- 6) μs using a an electron multiplying charge coupled device (EMCCD) as a detector with high spatial resolution. This lifetime is consistent with values reported in the literature.

  15. Modelling refrigerant distribution in minichannel evaporators

    DEFF Research Database (Denmark)

    Brix, Wiebke

    distribution and on the cooling capacity of the evaporator. A one dimensional, steady state model of a minichannel evaporator is used for the study. An evaporator consisting of two multiport minichannels in parallel is used as a test case and two different refrigerants, R134a and R744 (CO2), are applied...... in the numerical experiments using the test case evaporator. The results show that the reduction in cooling capacity due to non-uniform airflow and non-uniform liquid and vapour distribution is generally larger when using R134a than when using CO2 as refrigerant. Comparing the capacity reductions with reductions......This thesis is concerned with numerical modelling of flow distribution in a minichannel evaporator for air-conditioning. The study investigates the impact of non-uniform airflow and non-uniform distribution of the liquid and vapour phases in the inlet manifold on the refrigerant mass flow...

  16. Systematic modelling and simulation of refrigeration systems

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.; Jakobsen, Arne

    1998-01-01

    The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose of the s......The task of developing a simulation model of a refrigeration system can be very difficult and time consuming. In order for this process to be effective, a systematic method for developing the system model is required. This method should aim at guiding the developer to clarify the purpose...... of the simulation, to select appropriate component models and to set up the equations in a well-arranged way. In this paper the outline of such a method is proposed and examples showing the use of this method for simulation of refrigeration systems are given....

  17. Basics of Low-temperature Refrigeration

    CERN Document Server

    Alekseev, A.

    2014-07-17

    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.

  18. Toxicity Data to Determine Refrigerant Concentration Limits

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Refrigerant Distribution Effects on the Performance of Microchannel Evaporators

    OpenAIRE

    Bowers, Chad D.; Mai, Helena; Elbel, Stefan; Hrnjak, Predrag S.

    2012-01-01

    The performance of air to refrigerant heat exchangers can be affected greatly by both refrigerant and air flow distribution. Maldistribution of either fluid stream can lead to reduced heat transfer effectiveness of the heat exchanger and thus lower system efficiency and capacity. Microchannel evaporators are especially susceptible to refrigerant maldistribution as they typically have many parallel channels fed by a common header or manifold. This paper outlines general trends in refrigerant f...

  20. THE STIRLING GAS REFRIGERATING MACHINE MECHANICAL DESIGN IMPROVING

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-06-01

    Full Text Available To improve the mechanical design of the piston Stirling gas refrigeration machine the structural optimization of rotary vane Stirling gas refrigeration machine is carried out. This paper presents the results of theoretical research. Analysis and prospects of rotary vane Stirling gas refrigeration machine for domestic and industrial refrigeration purpose are represented. The results of a patent search by mechanisms of transformation of rotary vane machines are discussed.

  1. THE STIRLING GAS REFRIGERATING MACHINE MECHANICAL DESIGN IMPROVING

    Directory of Open Access Journals (Sweden)

    V. V. Trandafilov

    2016-02-01

    Full Text Available To improve the mechanical design of the piston Stirling gas refrigeration machine the structural optimization of rotary vane Stirling gas refrigeration machine is carried out. This paper presents the results of theoretical research. Analysis and prospects of rotary vane Stirling gas refrigeration machine for domestic and industrial refrigeration purpose are represented. The results of a patent search by mechanisms of transformation of rotary vane machines are discussed

  2. Online load forecasting for supermarket refrigeration

    DEFF Research Database (Denmark)

    Bacher, Peder; Madsen, Henrik; Nielsen, Henrik Aalborg

    2013-01-01

    This paper presents a study of models for forecasting the load for supermarket refrigeration. The data used for building the forecasting models consists of load measurements, local climate measurements and weather forecasts. The load measurements are from a supermarket located in a village...... in Denmark. Every hour the hourly load for refrigeration for the following 42 hours is forecasted. The forecast models are time adaptive linear time-series models. The dynamic relations between the inputs and the load is modeled by simple transfer functions. The system operates in two regimes: one...

  3. Designing a magnet for magnetic refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerk, R.

    2010-03-15

    This thesis investigates the design and optimization of a permanent magnet assembly for use in a magnetic refrigeration device. The heart of magnetic refrigeration is the adiabatic temperature change in the magnetocaloric material which is caused by the magnetic field. In order to design an ideal magnet assembly the magnetocaloric materials and the refrigeration process itself and their properties and performance as a function of magnetic field are investigated. For the magnetocaloric materials it is the magnetization, specific heat capacity and adiabatic temperature that are investigated as functions of the magnetic field. Following this the process utilized by a magnetic refrigerator to provide cooling is investigated using a publicly available one dimensional numerical model. This process is called active magnetic regeneration (AMR). The aim is to determine the performance of the AMR as a function of the magnetic field in order to learn the properties of the optimal magnet assembly. The performance of the AMR as a function of the synchronization and width of the magnetic field with respect to the AMR cycle, the ramp rate and maximum value of the magnetic field are investigated. Other published magnet designs used in magnetic refrigeration devices are also evaluated, using a figure of merit based on the properties of the investigated magnetocaloric materials, to learn the properties of the best magnet designs to date. Following this investigation the Halbach cylinder, which is a hollow permanent magnet cylinder with a rotating remanent flux density, is investigated in detail as it forms the basis of many magnet designs used in magnetic refrigeration. Here the optimal dimensions of a Halbach cylinder, as well as analytical calculations of the magnetic field for a Halbach cylinder of infinite length, are presented. Once it has been determined which properties are desirable for a magnet used in magnetic refrigeration the design of a new magnet is described. This is

  4. Entanglement enhances cooling in microscopic quantum refrigerators.

    Science.gov (United States)

    Brunner, Nicolas; Huber, Marcus; Linden, Noah; Popescu, Sandu; Silva, Ralph; Skrzypczyk, Paul

    2014-03-01

    Small self-contained quantum thermal machines function without external source of work or control but using only incoherent interactions with thermal baths. Here we investigate the role of entanglement in a small self-contained quantum refrigerator. We first show that entanglement is detrimental as far as efficiency is concerned-fridges operating at efficiencies close to the Carnot limit do not feature any entanglement. Moving away from the Carnot regime, we show that entanglement can enhance cooling and energy transport. Hence, a truly quantum refrigerator can outperform a classical one. Furthermore, the amount of entanglement alone quantifies the enhancement in cooling.

  5. Modular Modeling of a Refrigeration Container

    DEFF Research Database (Denmark)

    Kjær Sørensen, Kresten; Juel Skovrup, Morten; M. Jessen, Lars

    2015-01-01

    This paper presents the modeling of a refrigeration container for use as a reference for energy-optimizing controller design. The model is based on first principles in order to conserve mass and energy, but various assumptions are used to simplify the equations, resulting in a unified model...... for the Star Cool refrigeration unit, the container and the cargo. Comparisons between simulations using the model and measurements from a real container show an average error of less than ±1K on the states important for control....

  6. Development of a prototype optical refrigerator

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

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

  7. Boiling Heat Transfer to Halogenated Hydrocarbon Refrigerants

    Science.gov (United States)

    Yoshida, Suguru; Fujita, Yasunobu

    The current state of knowledge on heat transfer to boiling refrigerants (halogenated hydrocarbons) in a pool and flowing inside a horizontal tube is reviewed with an emphasis on information relevant to the design of refrigerant evaporators, and some recommendations are made for future research. The review covers two-phase flow pattern, heat transfer characteristics, correlation of heat transfer coefficient, influence of oil, heat transfer augmentation, boiling from tube-bundle, influence of return bend, burnout heat flux, film boiling, dryout and post-dryout heat transfer.

  8. Example of teaching practice for the comedy the Cabinet Minister's Wife by Branislav Nušić

    Directory of Open Access Journals (Sweden)

    Stanisavljević Nevena B.

    2017-01-01

    Full Text Available Awareness of the need for innovation and enrichment curriculum with comedies by Branislav Nušić inspired us to offer a creative methodological model processing for comedy Gospođa ministarka (The Cabinet Minister's Wife, in order to point out the possibility of it's involvement in the educational process and the positive effects that such action had. The reason for selecting just this comedy lies in the fact that, despite the fact that it's title well understood, it's ideological layer, referring to criticism of the government and power, can positively influence the development of student's personality traits. Our proposal is to analyze comedy Gospođa ministarka (The Cabinet Minister's Wife in the sixth grade, however, such an approach does not cease the possibility of interpretation of a play in teaching practices, but use the offered model as the starting point of any new readings and interpretation in the educational practice.

  9. improvement to the design of a solid absorption solar refrigerator

    African Journals Online (AJOL)

    user

    The paper presents the highlights of the design of an existing solid absorption solar refrigerator, using CaCl2 stabilised ... design of a new model refrigerator, to improve the refrigerator performance are then presented. Introduction ..... O. C. Iloeje, "Parametric Effects on the Performance of a Solar Powered Solid Absorption.

  10. 49 CFR 179.102-17 - Hydrogen chloride, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen chloride, refrigerated liquid. 179.102-17...) § 179.102-17 Hydrogen chloride, refrigerated liquid. Each tank car used to transport hydrogen chloride, refrigerated liquid must comply with the following special requirements: (a) The tank car must comply with...

  11. 49 CFR 179.102-1 - Carbon dioxide, refrigerated liquid.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Carbon dioxide, refrigerated liquid. 179.102-1...) § 179.102-1 Carbon dioxide, refrigerated liquid. (a) Tank cars used to transport carbon dioxide, refrigerated liquid must comply with the following special requirements: (1) All plates for tank, manway nozzle...

  12. 46 CFR 58.20-15 - Installation of refrigerating machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Installation of refrigerating machinery. 58.20-15 Section 58.20-15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN... refrigerating machinery. (a) Where refrigerating machines are installed in which anhydrous ammonia is used as a...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1994-05-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-02-01

    requirements to achieve grade 1 on the label are now virtually as stringent as those for US Energy Star-qualified or EU A-grade refrigerators. When the energy information label went into effect in March 2005, refrigerator manufacturers were required to display their declared level of efficiency on the label and report it to the China Energy Label Center (CELC), a newly established unit of CNIS responsible for label program management. Because of the visible nature of the label, it was found, through a METI/IEEJ-supported study, that MEPS non-compliance dropped from 4% to zero after the label became mandatory, and that the percentage of higher-grade refrigerators increased. This suggests that the label itself does have potential for shifting the market to higher-efficiency models (Lin 2007). One challenge, however, of assessing this potential impact is the lack of a comprehensive baseline of market efficiency and a program to evaluate the market impact on a yearly basis. As a result, the impact evaluation in this study draws upon the market transformation experience of the related EU energy information label, for which quantitative assessments of its market impact exist. By assuming a parallel process unfolding in China, it is possible to look at the potential impact of the label to 2020. The results of the analysis demonstrates that a robust market transformation program in China focused on the energy information label could save substantial amounts of electricity by 2020, totaling 16.4 TWh annually by that year, compared to a case in which the efficiency distribution of refrigerators was frozen at the 2007 level. Remarkably, the impact of a successful market transformation program with the label would essentially flatten the consumption of electricity for refrigerator use throughout most of the next decade, despite the expectations of continued growth in total stock by nearly 190 million units. At the end of this period, total consumption begins to rise again, as the least

  15. Kokanee Stock Status and Contribution Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1988 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, Edward C.

    1989-02-01

    The kokanee Oncorhynchus nerka rehabilitation program for Lake Pend Oreille continued to show progress during 1988. Estimated kokanee abundance in early September was 10.2 million fish. This estimate is 70% higher than 1987 and 140% higher than the populations's low point in 1986. Increased population size over the past two years is the result of two consecutive strong year classes produced from high recruitment of hatchery and wild fry. High recruitment of wild fry in 1988 resulted from good parental escapement (strong year class) in 1987 and relatively high fry survival. Hatchery fry made up 51% of total fry recruitment (73% of total fry biomass), which is the largest contribution since hatchery supplementation began in the 1970s. High hatchery fry abundance resulted from a large release (13 million fry) from Cabinet Gorge Hatchery and excellent fry survival (29%) during their first summer in Lake Pend Oreille. Improved fry release strategies enhanced survival, which doubled from 1987 to 1988 and was ten times higher than survival in 1986. Our research goal is to maintain 30% survival so we are very optimistic, but need to replicate additional years to address annual variability. 27 refs., 24 figs., 3 tabs.

  16. Evaluation of a storage cabinet for heat-sensitive endoscopes in a clinical setting.

    Science.gov (United States)

    Grandval, P; Hautefeuille, G; Marchetti, B; Pineau, L; Laugier, R

    2013-05-01

    In most countries, endoscopes must be disinfected or fully reprocessed before the beginning of each session, even if they were cleaned and disinfected after their last use. Several storage cabinets for heat-sensitive endoscopes (SCHE) are commercially available. They are designed to maintain the microbiological quality of reprocessed endoscopes for a predefined period of time validated by the SCHE manufacturer. Use of an SCHE increases the acceptable storage time before it is necessary to re-disinfect the endoscope. To evaluate the efficacy of an SCHE (DSC8000, Soluscope, SAS Marseilles, France) in a clinical setting. The microbiological quality of endoscopes was assessed after 72 h of storage in an SCHE (Group I), and compared with the microbiological quality of endoscopes stored for 72 h in a clean, dry, dedicated cupboard without morning disinfection (Group II) and the microbiological quality of endoscopes stored for 72 h in a clean, dry, dedicated cupboard with morning disinfection (Group III). Forty-one endoscopes in each group were sampled for microbiological quality. Endoscope contamination levels were analysed according to guidelines published by the National Technical Committee on Nosocomial Infection in 2007. Use of an SCHE helps to maintain the microbiological quality of endoscopes, provided that staff members are well trained and all practices are framed by a proven quality assurance process. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  17. Eighteenth Century Technological Efficiency: The Reuse of Brazilian Sugar Chest Wood in Portuguese Cabinet Manufacture

    Directory of Open Access Journals (Sweden)

    Rocio Astrid BERNAL

    2011-12-01

    Full Text Available We studied decorative Portuguese furniture from the 18th century Clerigos Church in Porto, to identify the woods used, to analyze their possible origin and understand the criteria for wood choice, according to sample location. We identified wood from Acacia sp., Castanea sativa, Couratari sp. and Dalbergia nigra. D. nigra, Acacia sp. and Couratari sp. may have arrived from Brazil, according to their natural distribution and the Portuguese colonial routes; C. sativa was abundant in the North Region of Portugal. In the 18th century, golden metal brass over black furniture was in fashion in Portuguese ecclesiastical cabinet making. Due to its dark colour, Dalbergia nigra was a desirable wood for the exposed structures of ecclesiastical furniture, such as top drawers and top tables. Couratari is a pale wood. Therefore, it was used in the inner structure of the drawers and legs. Acacia wood was also used in internal parts due to its durability. C. sativa was local and extensive; its wood was used in the inner structures, where it could not be seen. Marks were found in the Couratari wood, which indicated that the timber from chest boards employed to carry sugar from Brazil to Portugal was reused. The high silica content of Couratari wood makes it ideal for building sugar chests.

  18. Commercial Refrigeration: Heat Transfer Optimization and Energy Reduction, Measurement and Verification of a Liquid Refrigerant Pump System Retrofit

    Energy Technology Data Exchange (ETDEWEB)

    Gaul, Chris [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sheppy, Michael [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-22

    This study describes the test results of a Refrigerant Pump System integrated into a commercial supermarket direct expansion (DX) vapor compression refrigeration system. The Liquid Refrigerant Pump System retrofit (patent-pending; application number 13/964,198) was introduced to NREL in August 2014 by CTA Architects Engineers.

  19. Influence of Refrigerant Mass Fraction in the Performance of an Ammonia Absorption Refrigerator

    National Research Council Canada - National Science Library

    TAKESHITA, Keisuke; AMANO, Yoshiharu; HASHIZUME, Takumi; TAKEI, Toshitaka; TOMIZAWA, Masao

    2004-01-01

    .... We propose a method to estimate the refrigerant mass fraction with mass and energy balance equations around the separator at the inlet of the evaporator, and describe the results of experiments which...

  20. Conversion of cold beverage dispenser's refrigeration system to R744 refrigerant

    OpenAIRE

    Visek, Matej; Elbel, Stefan; Hrnjak, Pega

    2016-01-01

    Cold beverage dispensers belong to the group of light commercial refrigeration machines that includes beverage coolers, ice machines and storage units for food items. Beverage dispensers use a vapor compression system to charge a thermal storage, usually an ice bank, which is used to indirectly cool tap water and beverage concentrate. For these machines, R290 (propane) and R744 (carbon dioxide) are among the favorite candidates to completely replace high GWP HFC refrigerants in the future. Be...

  1. Experimental Investigation of COP Using Hydro Carbon Refrigerant in a Domestic Refrigerator

    Science.gov (United States)

    Peyyala, Anusha; Sudheer, N. V. V. S., Dr

    2017-08-01

    Under the Montreal protocol 1987 researchers worked on the possibility of alternative refrigerants like Hydroflourocarbon’s [HFC’s] and Hydrocarbon’s[HC’s] to replace refrigerants Chloroflourocarbon’s [CFC’s] and Hydrochlorofluorocarbons [HCFC’s] in air-conditioning and cooling systems that are destroying the ozone layer. On October 15, 2016 one hundred and ninety plus countries including India came to an agreement called Kigali Amendment to phase out potent green house gases by 2045 there by preventing 0.5 C rise in global temperature by 2050. Under this agreement India agreed to a timeline to reduce the use of HFC’s by 85% of their baseline by 2045. HFC’s are a family of greenhouse gases that are largely used in refrigerators and air conditioners which have reduced the Ozone Depleting Potential [ODP] but increased the Global Warming Potential [GWP]. Refrigeration and its applications are important in almost all branches of industry, so engineers have to become aware of its principles, uses and limitations. Since the decade there are major changes in the choice of refrigerants due to environmental factors. This issue is on-going and new developments should be developed to decrease the environmental problems. So the aim of this paper is to present the experimental analysis of Coefficient of performance [COP] values using R134a [HFC] & R600a [HC] as Refrigerants in Domestic refrigerator using conventional and nonconventional energy sources. Based on the results, usage of R600a in domestic refrigerators will reduce the ODP and also GWP problems which fulfills the nominal requirements of human beings without any effects.

  2. Regenerative sorption compressors for cryogenic refrigeration

    Science.gov (United States)

    Bard, Steven; Jones, Jack A.

    Dramatic efficiency improvements for sorption coolers appear possible with use of compressor heat regeneration techniques. The general theory of sorption compressor heat regeneration is discussed in this paper, and several design concepts are presented. These designs result in long-life, low-vibration cryocoolers that potentially have efficiencies comparable to Stirling refrigerators for 65 to 90 K spacecraft instrument cooling applications.

  3. Eco-Friendly Alternative Refrigeration Systems

    Indian Academy of Sciences (India)

    lies in the development of an air-conditioning system that is light, inexpensive and efficient. The technology ideally lends itself to be used in electric cars, and the cooling process can also be reversed to heat the vehicle. Thermoelectric Refrigeration. Principle of Technology. In 1823, Seebeck discovered that a voltage drop ...

  4. The smallest refrigerators can reach maximal efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Skrzypczyk, Paul; Brunner, Nicolas; Popescu, Sandu [H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Linden, Noah, E-mail: paul.skrzypczyk@bristol.ac.uk, E-mail: n.brunner@bristol.ac.uk [Department of Mathematics, University of Bristol, University Walk, Bristol BS8 1TW (United Kingdom)

    2011-12-09

    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. (fast track communication)

  5. a solid absorbent for solar refrigeration

    African Journals Online (AJOL)

    user

    ABSTRACT. The thermophysical properties of 'Nsukkanut', - a CaCl2/CaSO4 absorbent mixture used in solid absorption solar refrigeration [1], were studied in this report. The transient experimental technique of Beck and Al-Araji. [12] was used in determining the effective thermal conductivity, specific heat and bulk thermal ...

  6. The absoption refrigerator as a thermal transformer

    OpenAIRE

    Herrmann, Friedrich

    2008-01-01

    The absorption refrigerator can be considered a thermal transformer, i.e. a device that is analogous to the electric transformer. The analogy is based on a correspondence between the extensive quantities entropy and electric charge and that of the intensive variables temperature and electric potential.

  7. The Absorption Refrigerator as a Thermal Transformer

    Science.gov (United States)

    Herrmann, F.

    2009-01-01

    The absorption refrigerator can be considered a thermal transformer, that is, a device that is analogous to the electric transformer. The analogy is based on the correspondence between the extensive quantities, entropy and electric charge and the intensive variables, temperature and electric potential. (Contains 1 footnote and 6 figures.)

  8. Air Conditioning and Refrigeration. Book Two.

    Science.gov (United States)

    Wantiez, Gary W.

    This curriculum guide (book II), along with book I, is designed to provide students with the basic skills for an occupation in air conditioning and refrigeration. Six major areas are included, each consisting of one or more units of instruction. These areas and their respective units are titled as follows: Electricity (fundamentals of electricity,…

  9. Materials for room temperature magnetic refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Rosendahl Hansen, B.

    2010-07-15

    Magnetic refrigeration is a cooling method, which holds the promise of being cleaner and more efficient than conventional vapor-compression cooling. Much research has been done during the last two decades on various magnetic materials for this purpose and today a number of materials are considered candidates as they fulfill many of the requirements for a magnetic refrigerant. However, no one material stands out and the field is still active with improving the known materials and in the search for a better one. Magnetic cooling is based on the magnetocaloric effect, which causes a magnetic material to change its temperature when a magnetic field is applied or removed. For room temperature cooling, one utilizes that the magnetocaloric effect peaks near magnetic phase transitions and so the materials of interest all have a critical temperature within the range of 250 - 310 K. A magnetic refrigerant should fulfill a number of criteria, among these a large magnetic entropy change, a large adiabatic temperature change, preferably little to no thermal or magnetic hysteresis and the material should have the stability required for long term use. As the temperature range required for room temperature cooling is some 40 - 50 K, the magnetic refrigerant should also be able to cover this temperature span either by exhibiting a very broad peak in magnetocaloric effect or by providing the opportunity for creating a materials series with varying transition temperatures. (Author)

  10. Anaesthetic potency and physiological effects of refrigerated ...

    African Journals Online (AJOL)

    Several in vitro studies have justified the use of thiopentone solutions beyond the period recommended by the manufacturer. We conducted this in vivo study to investigate the anaesthetic potency and physiological effect of refrigerated thiopentone solution. Rabbits in four groups designated A, B, C and D were ...

  11. Materials for Room Temperature Magnetic Refrigeration

    DEFF Research Database (Denmark)

    Hansen, Britt Rosendahl

    Magnetic refrigeration is a cooling method, which holds the promise of being cleaner and more efficient than conventional vapor-compression cooling. Much research has been done during the last two decades on various magnetic materials for this purpose and today a number of materials are considere...... cooling is some 40 – 50 K, the magnetic refrigerant should also be able to cover this temperature span either by exhibiting a very broad peak in magnetocaloric effect or by providing the opportunity for creating a materials series with varying transition temperatures.......Magnetic refrigeration is a cooling method, which holds the promise of being cleaner and more efficient than conventional vapor-compression cooling. Much research has been done during the last two decades on various magnetic materials for this purpose and today a number of materials are considered...... candidates as they fulfill many of the requirements for a magnetic refrigerant. However, no one material stands out and the field is still active with improving the known materials and in the search for a better one. Magnetic cooling is based on the magnetocaloric effect, which causes a magnetic material...

  12. Modeling of In-vehicle Magnetic refrigeration

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Bahl, Christian; Engelbrecht, Kurt

    2012-01-01

    A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose...... the demands on cooling power density, temperature difference between hot and cold side, transient properties and COP, will be high....

  13. Progress in magnetic refrigeration and future challenges

    DEFF Research Database (Denmark)

    Engelbrecht, Kurt; Pryds, Nini

    2014-01-01

    refrigerators have the potential for high efficiency. However, reported device COPs for laboratory devices are still well below commercially available vapor compression systems. In order to significantly improve AMR efficiency, several loss mechanisms must be reduced and other aspects of system design...

  14. Microporous Carbon Disks For Sorption Refrigerators

    Science.gov (United States)

    Munukutla, Lakshmi V.; Moore, Mark R.

    1993-01-01

    Slow, carefully controlled pyrolysis found to turn polyvinylidene chloride disks into carbon disks having small pores and large surface areas. Disks exhibit high adsorptivities making them useful in krypton-sorption refrigerators. Carbons made from polyvinylidene chloride have greater adsorptive capacities. Thermal instability controlled and variability of product reduced by careful control of rates of heating, heating times, and rate of final cooling.

  15. Waste Heat Recapture from Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL

    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.

  16. Dynamic Heat Transfer Model of Refrigerated Foodstuff

    DEFF Research Database (Denmark)

    Cai, Junping; Risum, Jørgen; Thybo, Claus

    2006-01-01

    as what is the optimal defrost scheme from food quality point of view are answered. This will serve as a prerequisite of designing of optimal control scheme for the commercial refrigeration system, aiming at optimizing a weighed cost function of both food quality and overall energy consumption of system....

  17. Topology Optimization of Regenerators for Magnetic Refrigeration

    Science.gov (United States)

    Okkels, Fridolin; Panagakos, Grigorios

    2010-11-01

    We show a free form geometrical optimization of a simple regenerator model and how it relates to improvements of magnetic refrigerator systems. Magnetic refrigeration systems utilize the magnetocaloric effect to separate the ambient temperature into hot and cold regions, through a thermodynamic cycle. In the specific model [1], a small-scale regenerator support the temperature difference, and we apply the method of topology optimization to improve the existing design. In order for the high-level implementation of topology optimization to work [2], the model has to be steady state, and therefore the refrigeration cycle has been reformulated, using harmonically varying fields, into an amplitude model. The amplitude model nicely reproduces the results from direct simulation of the thermodynamic cycle, and initial results from the topology optimization are presented. [4pt] [1] T. F. Petersen, "Numerical modelling and analysis of a room temperature magnetic refrigeration system," PhD-thesis, DTU Risø, Denmark (2007)[0pt] [2] L.H. Olesen, F. Okkels, and H. Bruus, Int. J. Num. Meth. Eng. 65, 975 (2006)

  18. Analysis of refrigerant mal-distribution

    DEFF Research Database (Denmark)

    Kærn, Martin Ryhl; Elmegaard, Brian

    2009-01-01

    to be two straight tubes. The refrigerant maldistribution is then induced to the evaporator by varying the vapor quality at the inlet to each tube and the air-flow across each tube. Finally it is shown that mal-distribution can be compensated by an intelligent distributor, that ensures equal superheat...

  19. High performance magnetocaloric perovskites for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bahl, Christian R. H.; Velazquez, David; Nielsen, Kaspar K.

    2012-01-01

    We have applied mixed valance manganite perovskites as magnetocaloric materials in a magnetic refrigeration device. Relying on exact control of the composition and a technique to process the materials into single adjoined pieces, we have observed temperature spans above 9 K with two materials...

  20. Hybrid control of the distributed refrigeration system

    DEFF Research Database (Denmark)

    Chen, L.; Wisniewski, R.

    2010-01-01

    consumption. The paper focuses on synchronization dynamics of the refrigeration system modeled as a piecewise-affine switched system. System behaviors are analyzed using chaos theory. The synchronization phenomenon is interpreted as a stable low-period orbit; if the system has a high-order periodic orbit...

  1. EXERGETIC PERFORMANCE OF A DOMESTIC REFRIGERATOR USING R12 AND ITS ALTERNATIVE REFRIGERANTS

    Directory of Open Access Journals (Sweden)

    BUKOLA O. BOLAJI

    2010-12-01

    Full Text Available Production and use of R12 and other chlorofluorocarbon refrigerants will be prohibited completely all over the world in the year 2010 due to their harmful effects on the earth’s protective ozone layer. Therefore, in this study, the exergetic performance of a domestic refrigerator using two environment-friendly refrigerants (R134a and R152a was investigated and compared with the performance of the system when R12 (an ozone depleting refrigerant was used. The effects of evaporator temperature on the coefficient of performance (COP, exergy flow destruction, exergetic efficiency and efficiency defect in the four major components of the cycle for R12, R134a and R152a were experimentally investigated. The results obtained showed that the average COP of R152a was very close to that of R12 with only 1.4% reduction, while 18.2% reduction was obtained for R134a in comparison with that of R12. The highest average exergetic efficiency of the system (41.5% was obtained using R152a at evaporator temperature of -3.0oC. The overall efficiency defect in the refrigeration cycle working with R152a is consistently better (lower than those of R12 and R134a. Generally, R152a performed better than R134a in terms of COP, exergetic efficiency and efficiency defect as R12 substitute in domestic refrigeration system.

  2. Invisible Display in Aluminum

    DEFF Research Database (Denmark)

    Prichystal, Jan Phuklin; Hansen, Hans Nørgaard; Bladt, Henrik Henriksen

    2005-01-01

    for an integrated display in a metal surface is often ruled by design and functionality of a product. The integration of displays in metal surfaces requires metal removal in order to clear the area of the display to some extent. The idea behind an invisible display in Aluminum concerns the processing of a metal...

  3. Methods development for measuring and classifying flammability/combustibility of refrigerants. Interim report, Task 1 -- Annotated bibliography and summary

    Energy Technology Data Exchange (ETDEWEB)

    Heinonen, E.W.; Tapscott, R.E. [New Mexico Univ., Albuquerque, NM (United States). Center for Global Enviromental Technology

    1994-06-01

    For Task 1 of the flammable refrigerant methods development contract, NMERI performed a literature search to identify references on the flammability of refrigerants. A database to store a bibliographic record of the literature search was then developed. This database is contained in the Microsoft Access{reg_sign} relational database management system for Windows{trademark}. Searches for applicable sources were made on-line using the STN{reg_sign} scientific and technical network; off-line using the National Technical Information Service (NTIS) database; WorldCat CD-rom database; the University of New Mexico library search; the Air-Conditioning and Refrigeration institute (ARI) Refrigerant Database; and personal contacts. Three specific areas were searched: refrigerant properties, flammability test methods, and ignition technology. Many of the articles retrieved fall into multiple categories. Ignition technology was included as a separate category because of the importance of the ignition process to flammability and the vast amount of information available on ignition of gaseous fuels, especially hydrocarbons. Over 90 separate references have been entered into the database. Two separate report formats have been developed to display the results of the literature search. Appendix B is the short report format--without abstract, while Appendix C is the long format--with abstract.

  4. Variable speed hermetic reciprocating compressors for domestic refrigerators

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.

    1998-01-01

    This article describes the results of a both theoretical and experimental investigation of the performance of variable speed hermetic reciprocating compressors for domestic refrigerators. The investigation was performed as a part of a larger research project with the objective of reducing...... the energy consumption of domestic refrigerators by increasing the efficiency of the refrigeration system. The improvement of the system efficiency was to be obtained by introducing continuous operation and use variable speed compressors for controlling the capacity of the refrigeration system....... It was the aim of the project to double the efficiency of the refrigeration system and thereby reduce the energy consumption of the refrigerator by 50% compared to a standard refrigerator available on the market to day....

  5. Recent progress in magnetic refrigeration; Jiki reito no kenkyu doko

    Energy Technology Data Exchange (ETDEWEB)

    Numazawa, T. [National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

    1997-05-25

    Nearly 20 years have passed since the regular study in magnetic refrigeration commenced. However it has not been put to practical use, because the technology depends largely not only on magnetic materials but also on superconduction magnets, heat switches, and etc. This paper reviews the outline of studies in magnetic refrigeration and their future. The principle of magnetic refrigeration and the merit and demerit are described first under the heading of the special features of magnetic refrigeration. Magnetic materials developed so far are also introduced. Then a Carnot cycle magnetic refrigeration is explained. The study in space satellites by NASA, adiabatic demagnetization refrigerators and etc. are introduced. In the section of magnetic regenerative refrigerators, continuous Carnot active magnetic regenerators (AMR) and Brayton AMR are described. The actual proof study of AMR has been over and the application study has commenced. 36 refs., 14 figs., 2 tabs.

  6. Regenerative characteristics of magnetic or gas Stirling refrigeration cycle

    Science.gov (United States)

    Chen, J.; Yan, Z.

    A general criterion to distinguish whether a Stirling refrigeration cycle possesses the condition of perfect regeneration is given. It is proven using the criterion that a Stirling refrigeration cycle using a simple paramagnetic or ferromagnetic material as the working substance possesses the condition of perfect regeneration, as does a Stirling refrigeration cycle using an ideal or van der Waals gas as the working substance. However, a Stirling refrigeration cycle using a gas which is described by the Redlich-Kwong, Beattie-Bridgeman, Benedict-Webb-Rubin, Dieterici, Berthelot, or Martin-Hou equation as the working substance does not possess the condition of perfect regeneration and its coefficient of performance is always smaller than that of the Carnot refrigeration cycle for the same temperature range. Moreover, the effect of non-perfect regeneration on the level of refrigeration and the coefficient of performance of a Stirling refrigeration cycle is expounded using a strict equation of state.

  7. Development of a new magnetocaloric material used in a magnetic refrigeration device

    Directory of Open Access Journals (Sweden)

    Hardy V.

    2012-06-01

    Full Text Available Testing directly a magnetocaloric material in a magnetic refrigeration (MR system is the best way to judge of its applicative potentialities. In this spirit, an oxide expected to show promising magnetocaloric properties around room temperature (Pr0.65Sr0.35MnO3 was produced in large scale and shaped in order to build a regenerator. Magnetization, heat capacity, resistivity, thermal conductivity and a direct test in a MR device were carried out on this manganite. The results were compared to those observed in the reference material which is Gadolinium. The two main conclusions of these preliminary results are: (i the Pr0.65Sr0.35MnO3 actually displays not only a significant magnetocaloric effect but also a real refrigeration capability at room temperature; (ii the temperature spans reached in these first experiments are even found to well compare with those obtained with Gd.

  8. Effects of open-air temperature on air temperature inside biological safety cabinet.

    Science.gov (United States)

    Umemura, Masayuki; Shigeno, Katsuro; Yamamura, Keiko; Osada, Takashi; Soda, Midori; Yamada, Kiyofumi; Ando, Yuichi; Wakiya, Yoshifumi

    2011-02-14

    In Japan, biological safety cabinets (BSCs) are normally used by medical staff while handling antineoplastic agents. We have also set up a class II B2 BSC at the Division of Chemotherapy for Outpatients. The air temperature inside this BSC, however, decreases in winter. We assumed that this decrease is caused by the intake of open-air. Therefore, we investigated the effects of low open-air temperature on the BSC temperature and the time of admixtures of antineoplastic agents. The studies were conducted from January 1 to March 31, 2008. The outdoor air temperature was measured in the shade near the intake nozzle of the BSC and was compared with the BSC temperature. The correlation between the outdoor air temperature and the BSC temperature, the dissolution time of cyclophosphamide (CPA) and gemcitabine (GEM), and accurate weight measurement of epirubicin (EPI) solution were investigated for low and normal BSC temperatures. The BSC temperature was correlated with the open-air temperature for open-air temperatures of 5-20°C (p < 0.0001). The dissolution of CPA and GEM at these temperatures was significantly delayed as compared to that at 25°C (p < 0.01 and p < 0.0001, respectively). The weight measurement of EPI solution using a syringe method lacks accuracy because of its high coefficient of viscosity at low temperatures (p < 0.01). These results suggest that the BSC temperature decreases below room temperature in winter when air is drawn from outdoors. We showed that the BSC temperature affects the dissolution rate of antineoplastic agents. Further, we suggested that the BSC temperature drop might delay the affair of the admixtures of antineoplastic agents and increase the waiting time of outpatients for chemotherapy.

  9. Validation of peracetic acid as a sporicide for sterilization of working surfaces in biological safety cabinets

    Directory of Open Access Journals (Sweden)

    Sandra Regina B.R. Sella

    2012-09-01

    Full Text Available Objectives: This study aimed to validate the use of peracetic acid as sporicide agent to decontaminate the workingsurface of a laminar flow biological safety cabinet (BSC, as an alternative to glutaraldehyde, including the selection ofthe disinfecting agent, the method of application, and the contact time.Materials and methods: The test organism was the spore-forming bacterium Bacillus atrophaeus ATCC 9372, which isa surrogate for an important infectious agent. Spore cultures were prepared from B. atrophaeus and used them to testthe sporicidal efficacy of peracetic acid on a BSC stainless steel surface. The performance of the sterilant was assessedby determining minimal inhibitory concentration (MIC and by microbial challenge in conditions that mimicked surfacecontamination. It was used 2.0% glutaraldehyde solution as the control.Results: The range of MICs was 0.6-1.1% for the control and 0.003-0.006% for the 0.2% peracetic acid solution. The 0.2%peracetic acid was an effective sterilant against B. atrophaeus spores (6-7 log spores, under defined conditions of useafter 40 min contact time, which was double that recommended on the product label.Conclusion: It was conclude that while the results of official methods can help to evaluate how products will perform,they are not usually reproducible in real-life user conditions and environments. Validation tests must be carried out toensure the efficacy and safety of surface decontamination procedures. J Microbiol Infect Dis 2012; 2(3: 93-99Key words: Peracetic acid, sporicidal activity, sterility, Bacillus atrophaeus spores, glutaraldehyde

  10. Effects of a direct refill program for automated dispensing cabinets on medication-refill errors.

    Science.gov (United States)

    Helmons, Pieter J; Dalton, Ashley J; Daniels, Charles E

    2012-10-01

    The effects of a direct refill program for automated dispensing cabinets (ADCs) on medication-refill errors were studied. This study was conducted in designated acute care areas of a 386-bed academic medical center. A wholesaler-to-ADC direct refill program, consisting of prepackaged delivery of medications and bar-code-assisted ADC refilling, was implemented in the inpatient pharmacy of the medical center in September 2009. Medication-refill errors in 26 ADCs from the general medicine units, the infant special care unit, the surgical and burn intensive care units, and intermediate units were assessed before and after the implementation of this program. Medication-refill errors were defined as an ADC pocket containing the wrong drug, wrong strength, or wrong dosage form. ADC refill errors decreased by 77%, from 62 errors per 6829 refilled pockets (0.91%) to 8 errors per 3855 refilled pockets (0.21%) (p error type detected before the intervention was the incorrect medication (wrong drug, wrong strength, or wrong dosage form) in the ADC pocket. Of the 54 incorrect medications found before the intervention, 38 (70%) were loaded in a multiple-drug drawer. After the implementation of the new refill process, 3 of the 5 incorrect medications were loaded in a multiple-drug drawer. There were 3 instances of expired medications before and only 1 expired medication after implementation of the program. A redesign of the ADC refill process using a wholesaler-to-ADC direct refill program that included delivery of prepackaged medication and bar-code-assisted refill significantly decreased the occurrence of ADC refill errors.

  11. Handbook of display technology

    CERN Document Server

    Castellano, Joseph A

    1992-01-01

    This book presents a comprehensive review of technical and commercial aspects of display technology. It provides design engineers with the information needed to select proper technology for new products. The book focuses on flat, thin displays such as light-emitting diodes, plasma display panels, and liquid crystal displays, but it also includes material on cathode ray tubes. Displays include a large number of products from televisions, auto dashboards, radios, and household appliances, to gasoline pumps, heart monitors, microwave ovens, and more.For more information on display tech

  12. Optimized heat exchanger unit in a thermoacoustic refrigerator

    Science.gov (United States)

    El-Fawal, Mawahib Hassan; Mohd-Ghazali, Normah

    2012-06-01

    Due to concern over the environmental impact caused by hazardous refrigerants, the last ten years or so has seen increasing research into thermoacoustic refrigeration. A thermoacoustic refrigerator is a device which uses acoustic power to pump heat. It holds the merits of simple mechanical design, absence of harmful refrigerants and having no or few moving parts. However, the performance of the thermoacoustic refrigerator, particularly the standing wave types, is currently not competitive compared to its counterpart conventional vapor-compression refrigerator. Thermoacoustic refrigeration prototypes, built up-to-date, achieved 0.1-0.2 relative coefficient of performance (COPR) compared with that of 0.33-0.5 for the conventional vapor-compression refrigerators. The poor heat exchanger design is one of the reasons for this poor efficiency. This paper discussed the influence of the thermoacoustic refrigerator heat exchanger's parameters on its design and the optimization of the performance of the system using the Lagrange multiplier method. The results showed that, the dissipated power is less than the published value by about 49% in the cold heat exchanger and about 38.5% in the hot heat exchanger. Furthermore, the increase of the cold heat exchanger effectiveness is found to be 3%. Thus, the decrease in the dissipated power in both heat exchangers with effective cold heat exchanger increases the performance of the thermoacoustic refrigerator.

  13. Performance Analysis of Multipurpose Refrigeration System (MRS on Fishing Vessel

    Directory of Open Access Journals (Sweden)

    Ust Y.

    2016-04-01

    Full Text Available The use of efficient refrigerator/freezers helps considerably to reduce the amount of the emitted greenhouse gas. A two-circuit refrigerator-freezer cycle (RF reveals a higher energy saving potential than a conventional cycle with a single loop of serial evaporators, owing to pressure drop in each evaporator during refrigeration operation and low compression ratio. Therefore, several industrial applications and fish storage systems have been utilized by using multipurpose refrigeration cycle. That is why a theoretical performance analysis based on the exergetic performance coefficient, coefficient of performance (COP, exergy efficiency and exergy destruction ratio criteria, has been carried out for a multipurpose refrigeration system by using different refrigerants in serial and parallel operation conditions. The exergetic performance coefficient criterion is defined as the ratio of exergy output to the total exergy destruction rate (or loss rate of availability. According to the results of the study, the refrigerant R32 shows the best performance in terms of exergetic performance coefficient, COP, exergy efficiency, and exergy destruction ratio from among the other refrigerants (R1234yf, R1234ze, R404A, R407C, R410A, R143A and R502. The effects of the condenser, freezer-evaporator and refrigerator-evaporator temperatures on the exergetic performance coefficient, COP, exergy efficiency and exergy destruction ratios have been fully analyzed for the refrigerant R32.

  14. Analysis of Refrigeration Cycle Performance with an Ejector

    Directory of Open Access Journals (Sweden)

    Wani J. R.

    2016-01-01

    Full Text Available A conventional refrigeration cycle uses expansion device between the condenser and the evaporator which has losses during the expansion process. A refrigeration cycle with ejector is a promising modification to improve the performance of conventional refrigeration cycle. The ejector is used to recover some of the available work so that the compressor suction pressure increases. To investigate the enhancement a model with R134a refrigerant was developed. To solve the set of equations and simulate the cycle performance a subroutine was written on engineering equation solver (EES environment. At specific conditions, the refrigerant properties are obtained from EES. At the design conditions the ejector refrigeration cycle achieved 5.141 COP compared to 4.609 COP of the conventional refrigeration cycle. This means that ejector refrigeration cycle offers better COP with 10.35% improvement compared to conventional refrigeration cycle. Parametric analysis of ejector refrigeration cycle indicated that COP was influenced significantly by evaporator and condenser temperatures, entrainment ratio and diffuser efficiency.

  15. Lunar Sample Display Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA provides a number of lunar samples for display at museums, planetariums, and scientific expositions around the world. Lunar displays are open to the public....

  16. A Compressive Superresolution Display

    KAUST Repository

    Heide, Felix

    2014-06-22

    In this paper, we introduce a new compressive display architecture for superresolution image presentation that exploits co-design of the optical device configuration and compressive computation. Our display allows for superresolution, HDR, or glasses-free 3D presentation.

  17. Design of refrigeration system using refrigerant R134a for macro compartment

    Science.gov (United States)

    Rani, M. F. H.; Razlan, Z. M.; Shahriman, A. B.; Yong, C. K.; Harun, A.; Hashim, M. S. M.; Faizi, M. K.; Ibrahim, I.; Kamarrudin, N. S.; Saad, M. A. M.; Zunaidi, I.; Wan, W. K.; Desa, H.

    2017-10-01

    The main objective of this study is to analyse and design an optimum cooling system for macro compartment. Current product of the refrigerator is not specified for single function and not compact in size. Hence, a refrigeration system using refrigerant R134a is aimed to provide instant cooling in a macro compartment with sizing about 150 × 150 × 250 mm. The macro compartment is purposely designed to fit a bottle or drink can, which is then cooled to a desired drinking temperature of about 8°C within a period of 1 minute. The study is not only concerned with analysing of heat load of the macro compartment containing drink can, but also focused on determining suitable heat exchanger volume for both evaporator and condenser, calculating compressor displacement value and computing suitable resistance value of the expansion valve. Method of optimization is used to obtain the best solution of the problem. Mollier diagram is necessary in the process of developing the refrigeration system. Selection of blower is made properly to allow air circulation and to increase the flow rate for higher heat transfer rate. Property data are taken precisely from thermodynamic property tables. As the main four components, namely condenser, compressor, evaporator and expansion valve are fully developed, the refrigeration system is complete.

  18. Screw Compressor Characteristics for Helium Refrigeration Systems

    Science.gov (United States)

    Ganni, V.; Knudsen, P.; Creel, J.; Arenius, D.; Casagrande, F.; Howell, M.

    2008-03-01

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

  19. An optimized magnet for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

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

  20. Energy analysis of a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Jensen, Jakob Munch; Jakobsen, Arne; Rasmussen, Bjarne D.

    1999-01-01

    From 1995 to 1998, an energy test method for supermarket refrigeration systems was developed in a project financed by the Danish Energy Agency. The purpose of the energy test method is to provide the means for evaluating the energy efficiency of these systems. The test method requires measurements...... of air temperatures and energy consumption to be carried out on the selected supermarket refrigeration system. In addition to the measurements required by the method, more measurements of individual energy consumptions have been carried in the case described in this paper. The purpose of the additional...... systems and therefore the experience with its application is limited. In the future, the energy test method may be used for evaluation of the efficiency of a new system or the improvement in efficiency when optimising an existing system....

  1. 78 FR 55889 - Energy Conservation Program: Energy Conservation Standards for Commercial Refrigeration Equipment

    Science.gov (United States)

    2013-09-11

    ... refrigerator-freezers with solid doors, and self-contained commercial refrigerators designed for pull-down... designed for holding temperatures \\14\\ (i.e., commercial refrigerators, freezers, and refrigerator-freezers.... Representative Unit Selection b. Baseline Models 2. Design Options 3. Refrigerants 4. Cost Assessment Methodology...

  2. Properties of Refrigerant Affect Compressor Design

    OpenAIRE

    Bukac, Hubert

    2012-01-01

    The paper examines selected thermodynamic properties of commonly used refrigerants and how they may affect design of a compressor. Among those properties are volumetric capacity, system pressure difference, system compression ratio, isentropic coefficient of performance, gas density, temperature of discharge gas, velocity of sound etc. The is made on the scale of evaporating temperatures from –40 oC to 30 oC, and condensing temperature 40.5 oC. The temperature of gas entering suction port is ...

  3. Synchronized acoustic refrigerator and heat engine (SARAH)

    OpenAIRE

    Banerjee, Aayan; Nayak, Gaurav

    2011-01-01

    In light of the present global energy scenario, it is imperative to seek novel and efficient energy solutions to redress the situation. Solar energy, wind energy, geothermal energy, ocean thermoclines and waste heat recovery are the major players in the sustainable energy field. In this paper we propose a Synchronized Acoustic Refrigerator And Heat Engine (SARAH), a Thermoacoustic (TA) device capable of harnessing these untapped sources in a cost-effective and efficient way on both small and ...

  4. 3D magnetometer for a dilution refrigerator

    Science.gov (United States)

    Uchaikin, S.; Likhachev, A.; Cioata, F.; Perminov, I.; Sanghera, H.; Singh, I.; Spear, P.; Chavez, P.; Han, X.; Petroff, C.; Rich, C.

    2012-12-01

    In this report, we describe a development of a three dimensional system for measurements of magnetic field at a wide temperature range of 300K-4K. The system is based on 8 AMR sensors and allows for control of the magnetic environment in a dilution refrigerator during the cool down of a superconducting processor. With a low noise signal processing electronics and a special sensor saturation circuit, a magnetic induction resolution below of 1 nT was achieved.

  5. Minimum Infectious Dose Determination of the Arkansas Delmarva Poultry Industry Infectious Bronchitis Virus Vaccine Delivered by Hatchery Spray Cabinet.

    Science.gov (United States)

    Leyson, Christina M; Hilt, Deborah A; Jordan, Brian J; Jackwood, Mark W

    2017-03-01

    The Arkansas Delmarva Poultry Industry (ArkDPI) infectious bronchitis virus (IBV) vaccine is effective when administered by eye drop, where the vaccine virus is able to infect and replicate well in birds and is able to induce protection against homologous challenge. However, accumulating evidence indicates that the ArkDPI vaccine is ineffective when applied by hatchery spray cabinet using the same manufacturer-recommended dose per bird. For this study, we aimed to determine the minimum infectious dose for the spray-administered ArkDPI vaccine, which we designate as the dose that achieves the same level of infection and replication as the eye drop-administered ArkDPI vaccine. To this end, we used increasing doses of commercial ArkDPI vaccine to vaccinate 100 commercial broiler chicks at day of hatch, using a commercial hatchery spray cabinet. The choanal cleft of each bird was swabbed at 7 and 10 days postvaccination, and real-time reverse-transcriptase PCR was performed. We observed that the level of infection and replication with spray vaccination matches with that of eye drop vaccination when chicks received 100 times the standard dose for the commercial ArkDPI vaccine. We further examined the S1 spike gene sequence from a subset of reisolated ArkDPI vaccine virus samples and observed that certain nucleotide changes arise in vaccine viruses reisolated from chicks, as previously reported. This suggests that the ArkDPI vaccine has a certain virus subpopulation that, while successful at infecting and replicating in chicks, represents only a minor virus subpopulation in the original vaccine. Thus, the minimum infectious dose for the ArkDPI vaccine using a hatchery spray cabinet appears to be dependent on the amount of this minor subpopulation reaching the chicks.

  6. Helium refrigeration system for hydrogen liquefaction applications

    Science.gov (United States)

    Nair, J. Kumar, Sr.; Menon, RS; Goyal, M.; Ansari, NA; Chakravarty, A.; Joemon, V.

    2017-02-01

    Liquid hydrogen around 20 K is used as cold moderator for generating “cold neutron beam” in nuclear research reactors. A cryogenic helium refrigeration system is the core upon which such hydrogen liquefaction applications are built. A thermodynamic process based on reversed Brayton cycle with two stage expansion using high speed cryogenic turboexpanders (TEX) along with a pair of compact high effectiveness process heat exchangers (HX), is well suited for such applications. An existing helium refrigeration system, which had earlier demonstrated a refrigeration capacity of 470 W at around 20 K, is modified based on past operational experiences and newer application requirements. Modifications include addition of a new heat exchanger to simulate cryogenic process load and two other heat exchangers for controlling the temperatures of helium streams leading out to the application system. To incorporate these changes, cryogenic piping inside the cold box is suitably modified. This paper presents process simulation, sizing of new heat exchangers as well as fabrication aspects of the modified cryogenic process piping.

  7. Stirling cycle engine and refrigeration systems

    Science.gov (United States)

    Higa, W. H. (Inventor)

    1976-01-01

    A Stirling cycle heat engine is disclosed in which displacer motion is controlled as a function of the working fluid pressure P sub 1 and a substantially constant pressure P sub 0. The heat engine includes an auxiliary chamber at the constant pressure P sub 0. An end surface of a displacer piston is disposed in the auxiliary chamber. During the compression portion of the engine cycle when P sub 1 rises above P sub 0 the displacer forces the working fluid to pass from the cold chamber to the hot chamber of the engine. During the expansion portion of the engine cycle the heated working fluid in the hot chamber does work by pushing down on the engine's drive piston. As the working fluid pressure P sub 1 drops below P sub 0 the displacer forces most of the working fluid in the hot chamber to pass through the regenerator to the cold chamber. The engine is easily combinable with a refrigeration section to provide a refrigeration system in which the engine's single drive piston serves both the engine and the refrigeration section.

  8. Real-Time Perceptual Simulation of Moving Sources: Application to the Leslie Cabinet and 3D Sound Immersion

    Directory of Open Access Journals (Sweden)

    T. Voinier

    2008-07-01

    Full Text Available Perception of moving sound sources obeys different brain processes from those mediating the localization of static sound events. In view of these specificities, a preprocessing model was designed, based on the main perceptual cues involved in the auditory perception of moving sound sources, such as the intensity, timbre, reverberation, and frequency shift processes. This model is the first step toward a more general moving sound source system, including a system of spatialization. Two applications of this model are presented: the simulation of a system involving rotating sources, the Leslie Cabinet and a 3D sound immersion installation based on the sonification of cosmic particles, the Cosmophone.

  9. Real-Time Perceptual Simulation of Moving Sources: Application to the Leslie Cabinet and 3D Sound Immersion

    Directory of Open Access Journals (Sweden)

    Kronland-Martinet R

    2008-01-01

    Full Text Available Perception of moving sound sources obeys different brain processes from those mediating the localization of static sound events. In view of these specificities, a preprocessing model was designed, based on the main perceptual cues involved in the auditory perception of moving sound sources, such as the intensity, timbre, reverberation, and frequency shift processes. This model is the first step toward a more general moving sound source system, including a system of spatialization. Two applications of this model are presented: the simulation of a system involving rotating sources, the Leslie Cabinet and a 3D sound immersion installation based on the sonification of cosmic particles, the Cosmophone.

  10. Fault detection and diagnosis for refrigerator from compressor sensor

    Science.gov (United States)

    Keres, Stephen L.; Gomes, Alberto Regio; Litch, Andrew D.

    2016-12-06

    A refrigerator, a sealed refrigerant system, and method are provided where the refrigerator includes at least a refrigerated compartment and a sealed refrigerant system including an evaporator, a compressor, a condenser, a controller, an evaporator fan, and a condenser fan. The method includes monitoring a frequency of the compressor, and identifying a fault condition in the at least one component of the refrigerant sealed system in response to the compressor frequency. The method may further comprise calculating a compressor frequency rate based upon the rate of change of the compressor frequency, wherein a fault in the condenser fan is identified if the compressor frequency rate is positive and exceeds a condenser fan fault threshold rate, and wherein a fault in the evaporator fan is identified if the compressor frequency rate is negative and exceeds an evaporator fan fault threshold rate.

  11. Magnetically suspended Stirling cryogenic space refrigerator Status report

    Science.gov (United States)

    Daniels, A.; Gasser, M.; Sherman, A.

    1982-01-01

    At the 1979 Cryogenic Engineering Conference, attention was given to conceptual designs of spaceborne cryogenic refrigeration systems which can provide long-term, unattended operation. Since that time, efforts have continued to translate one of those concepts into an engineering model. The present investigation is concerned with a refrigerator which was designed to generate 5 W of cooling power at a temperature of 65 K. The compression heat of the refrigerator is dissipated at a temperature of 300 K, and the output of the system is to be maintained reliably for a period of five years or longer. The refrigerator design is based on the Stirling cycle, which has an ideal efficiency equal to that of the Carnot cycle. Attention is given to some background information concerning a cryogenic refrigerator, the design of the refrigerator components, and the development status. The magnetic bearings and the linear motors have been tested at the component level.

  12. Magnetic Refrigeration – an Energy Efficient Technology for the Future

    DEFF Research Database (Denmark)

    Bahl, Christian Robert Haffenden; Smith, Anders; Pryds, Nini

    2009-01-01

    . This magnetocaloric effect is inherent to all magnetic materials, but manifests itself stronger in some materials. The thermodynamically reversible nature of the magnetocaloric effect holds out the promise of a more energy efficient method of refrigeration compared to conventional compressor technology. Coupling......Magnetic refrigeration is an emerging technology that has the potential to significantly reduce the energy consumption in the refrigeration sector. The technology relies on the heating and cooling of magnetic materials upon the application and removal of a magnetic field, respectively...... this with an absence of ozone depleting and greenhouse contributing gasses gives magnetic refrigeration the potential to become an environmentally sustainable technology. The magnetic refrigeration group at Risø DTU aims to demonstrate the technology in a prototype magnetic refrigeration device. Our work spans a wide...

  13. Prediction of thermodynamic properties of refrigerants using data mining

    Energy Technology Data Exchange (ETDEWEB)

    Kuecueksille, Ecir Ugur, E-mail: ecir@tef.sdu.edu.t [Department of Mechanical Education, Technical Education Faculty, Sueleyman Demirel University, 32260 Isparta (Turkey); Selbas, Resat, E-mail: selbas@tef.sdu.edu.t [Department of Mechanical Education, Technical Education Faculty, Sueleyman Demirel University, 32260 Isparta (Turkey); Sencan, Arzu, E-mail: sencan@tef.sdu.edu.t [Department of Mechanical Education, Technical Education Faculty, Sueleyman Demirel University, 32260 Isparta (Turkey)

    2011-02-15

    The analysis of vapor compression refrigeration systems requires the availability of simple and efficient mathematical formulations for the determination of thermodynamic properties of refrigerants. The aim of this study is to determine thermodynamic properties as enthalpy, entropy and specific volume of alternative refrigerants using data mining method. Alternative refrigerants used in the study are R134a, R404a, R407c and R410a. The results obtained from data mining have been compared to actual data from the literature. The study shows that the data mining methodology is successfully applicable to determine enthalpy, entropy and specific volume values for any temperature and pressure of refrigerants. Therefore, computation time reduces and simulation of vapor compression refrigeration systems is fairly facilitated.

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

    Science.gov (United States)

    Rice, C. K.; Sand, J. R.

    1993-01-01

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

  15. New Copper-based Heat Exchangers for Alternative Refrigerants

    OpenAIRE

    Shabtay, Yoram; Black, John; Kraft, Frank

    2014-01-01

    The ongoing global effort to replace current refrigerants with zero Ozone Depletion Potential (ODP) and virtually zero Global Warming Potential (GWP) refrigerants has important implications for heat exchangers, air conditioning system design, and the materials choices in these designs. Natural refrigerants with higher flammability, CO2, new HFC blends, and new HFO’s each place different requirements on the heat exchanger design, whether it be for higher equipment efficiency, to reduce refrige...

  16. Evaluating alternative refrigerants for the room air conditioner market

    OpenAIRE

    Back, Izabelle; Dunberger, Lars

    2015-01-01

    This study aimed to facilitate evaluation of alternative refrigerants for the air conditioner market. In order to achieve this target, two objectives were set. The first being the identification of alternative refrigerant with regard to regulations and trends. The second being enabling of thermodynamic evaluation of refrigerants for single components in air conditioners via design and installation of a test rig. A literature review was conducted to investigate the regulations, standards and t...

  17. Refrigeration arrangement and methods for reducing charge migration

    Science.gov (United States)

    Litch, Andrew D.; Wu, Guolian

    2017-04-11

    A refrigerator appliance including a refrigerant circuit between a condenser, an evaporator, and a compressor that includes two conduits and pressure reducing devices arranged in parallel between the evaporator and the condenser. The appliance also includes a valve system to direct refrigerant through one, both or none of the conduits and pressure reducing devices, and a heat exchanging member in thermal contact with either one pressure reducing device, or one conduit between the pressure reducing device and the valve system.

  18. The maximum cooling density of a realistic Stirling refrigerator

    Science.gov (United States)

    Berrin Erbay, L.; Yavuz, Hasbi

    1998-02-01

    The maximum cooling density of a Stirling refrigerator operating in a closed regenerative thermodynamic cycle is presented in this paper. The cooling density is the cooling load per unit volume of the refrigerator. Since the size of the refrigerator is involved in the cooling density, the maximization of the cooling density has given a critical compression ratio. The maximum cooling density serves as a better comparison criterion for thermoeconomic considerations.

  19. Refrigeration needs for sustainable preservation of horticultural products

    OpenAIRE

    Sousa, A.R.; Juliao, M.; Miguel, Maria Graça; Antunes, Maria Dulce; Panagopoulos, Thomas

    2011-01-01

    Fresh horticultural products are highly perishable and need refrigeration for further preservation. Refrigeration needs energy consumption with consequent economical cost and damage for the environment. The objective of the present work was to use efficiently the refrigeration according to the product needs and time for consumption. Salicornia ramosissima and Sarcocornia perennis fresh branch tips, which are used for fresh salads, were stored at 1, 4 and 9 °C for up to 21 days. In both specie...

  20. Refrigeration processes a practical handbook on the physical properties of refrigerants and their applications

    CERN Document Server

    Meacock, H M

    1979-01-01

    A comprehensive applications-oriented treatment of the subject in two parts. The first part forms a useful introduction to basic principles dealing with the definitions of the physical properties and outlines the method of their calculation. The second part is devoted to calculated data on a range of refrigerants by means of extensive tables and diagrams. The treatment takes the form of a data sheet, one for each of about thirty refrigerants; this data sheet gives the essential information from which close approximations of pressure, temperature, volume and enthalpy can be made for any predict

  1. Refrigeration Playbook. Heat Reclaim; Optimizing Heat Rejection and Refrigeration Heat Reclaim for Supermarket Energy Conservation

    Energy Technology Data Exchange (ETDEWEB)

    Reis, Chuck [CTA Architects Engineers, Boise, ID (United States); Nelson, Eric [CTA Architects Engineers, Boise, ID (United States); Armer, James [CTA Architects Engineers, Boise, ID (United States); Johnson, Tim [CTA Architects Engineers, Boise, ID (United States); Hirsch, Adam [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Doebber, Ian [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    The purpose of this playbook and accompanying spreadsheets is to generalize the detailed CBP analysis and to put tools in the hands of experienced refrigeration designers to evaluate multiple applications of refrigeration waste heat reclaim across the United States. Supermarkets with large portfolios of similar buildings can use these tools to assess the impact of large-scale implementation of heat reclaim systems. In addition, the playbook provides best practices for implementing heat reclaim systems to achieve the best long-term performance possible. It includes guidance on operations and maintenance as well as measurement and verification.

  2. REFRIGERANT/LUBRICANT MIXTURES: PROBLEMS OF APPLICATION AND PROPERTY RESEARCH

    Directory of Open Access Journals (Sweden)

    Yu. Semenyuk

    2013-10-01

    Full Text Available The results and generalizations of thermophysical property research for the refrigerant/lubricant mixtures are summarized. The methodological aspects of the experimental studies of the thermal properties of real working media for vapor compression refrigeration machines and the general principles of the thermodynamic properties simulation for such solutions are analyzed. It is shown that the admixtures of compressor oil in the refrigerant make the efficiency parameters of compressor systems much lower. The question of a selective solubility of the multicomponent refrigerants in compressor oils is discussed.

  3. Spacecraft-borne long life cryogenic refrigeration: Status and trends

    Science.gov (United States)

    Johnson, A. L.

    1983-01-01

    The status of cryogenic refrigerator development intended for, or possibly applicable to, long life spacecraft-borne application is reviewed. Based on these efforts, the general development trends are identified. Using currently projected technology needs, the various trends are compared and evaluated. The linear drive, non-contacting bearing Stirling cycle refrigerator concept appears to be the best current approach that will meet the technology projection requirements for spacecraft-borne cryogenic refrigerators. However, a multiply redundant set of lightweight, moderate life, moderate reliability Stirling cycle cryogenic refrigerators using high-speed linear drive and sliding contact bearings may possibly suffice.

  4. Magnesium Diboride Superconducting Coils for Adiabatic Demagnetization Refrigerators (ADR's) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For Adiabatic Demagnetization Refrigerators (ADRs) in space applications, it is desirable to have very light weight, small diameter, high current density...

  5. Transitioning to Low-GWP Alternatives in Commercial Refrigeration

    Science.gov (United States)

    This fact sheet provides information on low-GWP alternatives in commercial refrigeration. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

  6. Reasearch and Evaluation of Electromagnetic Fields of Refrigerators

    Directory of Open Access Journals (Sweden)

    Pranas Baltrėnas

    2013-12-01

    Full Text Available The use of refrigerators causes the occurence of electromagnetic fields that are invisible and intangible, which therefore makes difficulties in protecting ourselves from them. A refrigerator is an irreplaceable item in domestic household and thus can be hardly ignored by a modern way of human life. In order to preserve the characteristics of products, the refrigerator must operate continuously (24 hrs a day, regardless of the time of the year. This results in a huge increase in electricity consumption, which leads to energy consumption related pollution of the environment emitting CO2 gas. On these grounds, it is necessary to assess electromagnetic fields created by the refrigerator. Studies on electromagnetic fields produced by refrigerators were conducted in domestic premises where people spent a significant part of the day. For comparison purposes, five different power refrigerators were chosen (1 – 0.20 kW; 2 – 0.25 kW; 3 – 0.30 kW; 4 – 0.35 kW; 5 – 0.40 kW. The obtained results, according to the parameters of their electromagnetic fields, were presented in graphs and charts and showed that the values of electric and magnetic intensity of refrigerators depended on the distance and the power of the refrigerator. The conducted research also disclosed that none of tested refrigerators exceeded the permissible limits of electromagnetic fields.Article in Lithuanian

  7. Evaluating the effect of the space surrounding the condenser of a household refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Bassiouny, Ramadan [Dept. of Mech. Power Eng. and Energy, Faculty of Engineering, Minia University, Minia 61111 (Egypt)

    2009-11-15

    The paper presents an analytical and computational modeling of the effect of the space surrounding the condenser of a household refrigerator on the rejected heat. The driving force for rejecting the heat carried by the refrigerant from the interior of a refrigerator is the temperature difference between the condenser outer surface and surrounding air. The variation of this difference, because of having an insufficient space, increasing the room air temperature, or blocking this space, is of interest to quantify its effect The results showed that having an enough surrounding space width (s > 200 mm) leads to a decrease in the temperature of the air flowing vertically around the condenser coil. Accordingly, this would significantly increase the amount of heat rejected. Moreover, blocking this space retards the buoyant flow up the condenser surface, and hence increases the air temperature around the condenser. This would also decrease the heat rejected from the condenser. Predicted temperature contours are displayed to visualize the air plumes' variation surrounding the condenser in all cases. (author)

  8. Displaying gray shades in liquid crystal displays

    Indian Academy of Sciences (India)

    These transistors act as a switch to charge and hold the desired voltage across a pixel. Passive matrix LCDs are easy to fabricate and cost less as compared to the active matrix LCDs. Current trend demands gray scale and colour capa- bilities even for the displays in mobile phones. Passive matrix LCDs will be preferred as.

  9. Development of the style guide for DPPS FPD display design

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Chul; Lee, Yong Hee; Oh, In Seok; Lee, Jung Woon

    2003-05-01

    DPPS(Digital Plat Protection System) plays a role of generating the reactor trip signal and ESF(Engineered Safety Features) actuation signal when monitored plant processes reach the predefined limits. DPPS has 3 user interface system; RCM(Remote Control Modules) in MCB(Main Control Board), MTP(Maintenance and Test Panel) with main cabinets in MCR(Main Control Room) outer area, and RSP(Remote Shutdown Panel) near the plant. DPPS has been designed using analog displays and controls, a FPD(Flat Panel Display) in MTP is adopted firstly in Ulchin 5 and 6 plant. The FPD in Ulchin 5 and 6 has many screens to which the parts of analog displays and controls in the conventional MTP are transferred without many changes in appearance, thus there is no dedicated design guideline for the FPD in Ulchin 5 and 6. The adoption of FPD in subsequent DPPS is highly expected and so the guideline for FPD screen design is necessary. This report provides the styleguide applicable to design new FPD screens. This styleguide is developed on the basis of FPD screens in Ulchine 5 and 6 so that the satisfactory FPD screen design can be supported in case that the physical specification of new FPD is equal to that of Ulchine 5 and 6 FPD. However the sources related to each guide in the styleguide are described, thus the styleguide can be used to develop new styleguide for the different FPD specification.

  10. Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1989 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Hoelscher, Brian

    1990-04-01

    The kokanee Oncorhynchus nerka rehabilitation program for Lake Pend Oreille continued to show progress during 1989. Estimated kokanee abundance in late August was 7.71 million fish. Decreased population size is the result of lower hatchery and wild fry recruitment and low age 1+ survival. Lower recruitment of wild fry in 1989 resulted from a smaller parental escapement in 1988 and lower wild fry survival. Six fry release strategies were evaluated in 1989. Two groups were released in Clark Fork River to help improve a spawning run to Cabinet Gorge Hatchery. Survival from the mid-summer release, which was barged down Clark Fork River to avoid low flow problems, was not significantly different from the early release. The final assessment of these release strategies will be evaluated when adults return to Cabinet gorge Hatchery in 1992 and 1993. Fry released to support the Sullivan Springs Creek spawning run also survived will in 1989. Two open-water releases were made during early and mid-summer. 30 refs., 26 figs., 2 tabs.

  11. Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hessell, Edward

    2013-12-31

    The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

  12. Scalable Resolution Display Walls

    KAUST Repository

    Leigh, Jason

    2013-01-01

    This article will describe the progress since 2000 on research and development in 2-D and 3-D scalable resolution display walls that are built from tiling individual lower resolution flat panel displays. The article will describe approaches and trends in display hardware construction, middleware architecture, and user-interaction design. The article will also highlight examples of use cases and the benefits the technology has brought to their respective disciplines. © 1963-2012 IEEE.

  13. OLED displays and lighting

    CERN Document Server

    Koden, Mitsuhiro

    2017-01-01

    Organic light-emitting diodes (OLEDs) have emerged as the leading technology for the new display and lighting market. OLEDs are solid-state devices composed of thin films of organic molecules that create light with the application of electricity. OLEDs can provide brighter, crisper displays on electronic devices and use less power than conventional light-emitting diodes (LEDs) or liquid crystal displays (LCDs) used today. This book covers both the fundamentals and practical applications of flat and flexible OLEDs.

  14. Displaying Data As Movies

    Science.gov (United States)

    Moore, Judith G.

    1992-01-01

    NMSB Movie computer program displays large sets of data (more than million individual values). Presentation dynamic, rapidly displaying sequential image "frames" in main "movie" window. Any sequence of two-dimensional sets of data scaled between 0 and 255 (1-byte resolution) displayed as movie. Time- or slice-wise progression of data illustrated. Originally written to present data from three-dimensional ultrasonic scans of damaged aerospace composite materials, illustrates data acquired by thermal-analysis systems measuring rates of heating and cooling of various materials. Developed on Macintosh IIx computer with 8-bit color display adapter and 8 megabytes of memory using Symantec Corporation's Think C, version 4.0.

  15. JAVA Stereo Display Toolkit

    Science.gov (United States)

    Edmonds, Karina

    2008-01-01

    This toolkit provides a common interface for displaying graphical user interface (GUI) components in stereo using either specialized stereo display hardware (e.g., liquid crystal shutter or polarized glasses) or anaglyph display (red/blue glasses) on standard workstation displays. An application using this toolkit will work without modification in either environment, allowing stereo software to reach a wider audience without sacrificing high-quality display on dedicated hardware. The toolkit is written in Java for use with the Swing GUI Toolkit and has cross-platform compatibility. It hooks into the graphics system, allowing any standard Swing component to be displayed in stereo. It uses the OpenGL graphics library to control the stereo hardware and to perform the rendering. It also supports anaglyph and special stereo hardware using the same API (application-program interface), and has the ability to simulate color stereo in anaglyph mode by combining the red band of the left image with the green/blue bands of the right image. This is a low-level toolkit that accomplishes simply the display of components (including the JadeDisplay image display component). It does not include higher-level functions such as disparity adjustment, 3D cursor, or overlays all of which can be built using this toolkit.

  16. New concept of refrigeration. ; Magnetic refrigeration. Goku teion gijutsu. ; Jiki reito wo chushin to shite

    Energy Technology Data Exchange (ETDEWEB)

    Ogiwara, H.; Nakagome, H. (Toshiba Corp., Tokyo (Japan))

    1990-07-05

    This paper explained the principle, construction and problems of magnetic refrigeration which is an advanced refrigerartion technique. When strong field is applied to a paramagnet from the outside, the paramagnet bocomes a state of low entropy, that is, arranged electron spin. Adiabatic elimination of magnetic field deprives heat of lattice vibration of the paramagnet, returns it to the the entropy of electron spin without magnetic field, resulting itself to lower temperature state. This is the principle of adiabatic demaganetization by which a cycle to refrigerate and exhaust heat by a thermal switch can be constructed. But since the temperature range to which a paramagnet can exhibit the remarkable effect is limited, major problems are the selection of optimal paramagnet and how to get the AC or pulse magnetic field, although the practically necessary field may be obtained by a superconducting magnet. National Research Institute of Metals in Science and Technology Agency manufactured trially a stationary type magnetic refrigerator, of which maximum refrigerating capability was 100mW at 2K and minimum reachable temperature was 1.5K. 9 refs., 13 figs.

  17. PERFORMANCE OF A TWO-CYCLE REFRIGERATOR/FREEZER USING HFC REFRIGERANTS

    Science.gov (United States)

    A two-cycle 18 ft3 (0.51 m3) refrigerator/freezer (R/F) was tested utilizing American National Standards Institute (ANSI)/AHAM (1988) standards for energy consumption testing. A 34.9% energy consumption reduction was realized. This work presents a proven method of reducing the ...

  18. General RMP Guidance - Appendix E: Supplemental Risk Management Program Guidance for Ammonia Refrigeration Facilities

    Science.gov (United States)

    Additional information for food processors, food distributors, refrigerated warehouses, and any other facility with ammonia refrigeration system. Includes guidance on exemptions, threshold quantity, offsite consequence analysis.

  19. Toward High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  20. Towards High Performance in Industrial Refrigeration Systems

    DEFF Research Database (Denmark)

    Thybo, C.; Izadi-Zamanabadi, Roozbeh; Niemann, H.

    2002-01-01

    Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design in industr......Achieving high performance in complex industrial systems requires information manipulation at different system levels. The paper shows how different models of same subsystems, but using different quality of information/data, are used for fault diagnosis as well as robust control design...... in industrial refrigeration systems....

  1. Development of a novel rotary magnetic refrigerator

    DEFF Research Database (Denmark)

    Lozano, Jaime A.; Capovilla, Matheus S.; Trevizoli, Paulo V.

    2016-01-01

    with approximately 1.7 kg of gadolinium spheres (425-600 μm diameter) were placed in the magnetic gap. Two low-friction rotary valves were developed to synchronize the hydraulic and magnetic cycles. The valves were positioned at the hot end to avoid heat generation in the cold end. In this work, experimental results......A novel rotary magnetic refrigerator was designed and built at the Federal University of Santa Catarina (UFSC). The optimized magnetic circuit is a two-pole system in a rotor-stator configuration with high flux density regions of approximately 1 T. Eight pairs of stationary regenerator beds filled...

  2. Four-level refrigerator driven by photons

    Science.gov (United States)

    Wang, Jianhui; Lai, Yiming; Ye, Zhuolin; He, Jizhou; Ma, Yongli; Liao, Qinghong

    2015-05-01

    We propose a quantum absorption refrigerator driven by photons. The model uses a four-level system as its working substance and couples simultaneously to hot, cold, and solar heat reservoirs. Explicit expressions for the cooling power Q˙c and coefficient of performance (COP) ηCOP are derived, with the purpose of revealing and optimizing the performance of the device. Our model runs most efficiently under the tight coupling condition, and it is consistent with the third law of thermodynamics in the limit T →0 .

  3. Flow-synchronous field motion refrigeration

    Science.gov (United States)

    Hassen, Charles N.

    2017-08-22

    An improved method to manage the flow of heat in an active regenerator in a magnetocaloric or an electrocaloric heat-pump refrigeration system, in which heat exchange fluid moves synchronously with the motion of a magnetic or electric field. Only a portion of the length of the active regenerator bed is introduced to or removed from the field at one time, and the heat exchange fluid flows from the cold side toward the hot side while the magnetic or electric field moves along the active regenerator bed.

  4. Nonlinear Superheat Control of a Refrigeration Plant using Backstepping

    DEFF Research Database (Denmark)

    Rasmussen, Henrik

    2008-01-01

    This paper proposes a novel method for superheat and capacity control of refrigeration systems. The main idea is to control the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed and used in a backstepping design...

  5. development of a dual purpose refrigeration system for domestic use

    African Journals Online (AJOL)

    user

    1a4: Vaporization / Refrigeration Effect air: Dry air eff: Effective cap: Capillary. DB: Dry Bulb Temperature. REF: REFACON t or T. Ref: Total Refrigerator Load. Nigerian Journal of Technology (NIJOTECH). Vol. 35, No. .... (907 kg) of water at 0 °C to ice at 0 °C over a period of 24 hours. vii. The cooling load of the machine was.

  6. Refrigeration and Cryogenics Specialist. J3ABR54530

    Science.gov (United States)

    Air Force Training Command, Sheppard AFB, TX.

    This document package contains an Air Force course used to train refrigeration and cryogenics specialists. The course is organized in six blocks designed for group instruction. The blocks cover the following topics: electrical principles; fundamentals of tubing and piping; metering devices, motor controls, domestic and commercial refrigeration;…

  7. Lanthanide Al-Ni base Ericsson cycle magnetic refrigerants

    Science.gov (United States)

    Gschneidner, Jr., Karl A.; 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.

  8. Numerical approach to solar ejector-compression refrigeration system

    Directory of Open Access Journals (Sweden)

    Zheng Hui-Fan

    2016-01-01

    Full Text Available A model was established for solar ejector-compression refrigeration system. The influence of generator temperature, middle-temperature, and evaporator temperature on the performance of the refrigerant system was analyzed. An optimal generator temperature is found for maximal energy efficiency ratio and minimal power consumption.

  9. Closed Cycle Solar Refrigeration with the Calcium Chloride System ...

    African Journals Online (AJOL)

    A closed cycle solid absorption intermittent refrigerator, using CaC12 absorbent and NH3 refrigerant, was constructed and tested to obtain the instantaneous and cumulative available overall COP. The combined collector/absorber/generator unit had double glazing of 1.14 m2 exposed areas. The system was fitted with a ...

  10. improvement to the design of a solid absorption solar refrigerator

    African Journals Online (AJOL)

    user

    The paper presents the highlights of the design of an existing solid absorption solar refrigerator, using CaCl2 ... on the coupling of auxiliary heating systems to the solar powered refrigerator. A re-design of the ... Six collector tubes, having a perforated co-axial galvanised inner steel tube, were bonded to the plate at 152 mm.

  11. Use of glucose oxidase to improve refrigerated dough quality

    Science.gov (United States)

    Refrigerated dough encompasses a wide range of products including bread, rolls, pastries and pizza crust and is a very popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to e...

  12. Control and optimization of the refrigeration plant in a brewery

    DEFF Research Database (Denmark)

    Petersen, P.M; Qvale, Einar Bjørn

    1989-01-01

    The design and operation of a refrigeration plant in a brewery has been studied. The plant has been evaluated by using mathematical models of the components to simulate responses to real-life load variations. The study shows that the efficiency and economy of the actual refrigeration plant could...

  13. Profile: Department of Refrigeration and Heat Pump Technology

    NARCIS (Netherlands)

    Sluis, S.M. van der

    2000-01-01

    The activities in the fields of refrigeration and heatpumps are concentrated within TNO Environment, Energy and Process Innovation, Apeldoorn, and specifically within the Department of Refrigeration and Heat Pump Technology. The aim of this department is to develop, implement and test: — systems for

  14. Domestic Refrigeration, Freezer, and Window Air Conditioner Service. Teacher Edition.

    Science.gov (United States)

    Clemons, Mark

    This curriculum guide contains six units of instruction for a course in domestic refrigerator, freezer, and window air conditioner service. The units cover the following topics: (1) service fundamentals; (2) mechanical components and functions; (3) electrical components and control devices; (4) refrigerator and freezer service; (5) domestic ice…

  15. Helmet-Mounted Displays (HMD)

    Data.gov (United States)

    Federal Laboratory Consortium — The Helmet-Mounted Display labis responsible for monocular HMD day display evaluations; monocular HMD night vision performance processes; binocular HMD day display...

  16. Effective Monitor Display Design.

    Science.gov (United States)

    Harrell, William

    1999-01-01

    Describes some of the factors that affect computer monitor display design and provides suggestions and insights into how screen displays can be designed more effectively. Topics include color, font choices, organizational structure of text, space outline, and general principles. (Author/LRW)

  17. Jet printing flexible displays

    OpenAIRE

    Street, R. A.; Wong, W S; Ready, S. E.; Chabinyc, M.L; Arias, A.C.; Limb, S.; Salleo, A; Lujan, R.

    2006-01-01

    Jet printing is an interesting patterning technique for electronic devices because it requires no physical mask, has digital control of ejection, and provides good layer-to-layer registration. It also has the potential to reduce display manufacturing costs and enable roll-to-roll processing. The technique is illustrated with examples of prototype printed displays using amorphous silicon and polymer semiconductors.

  18. Standardizing visual display quality

    NARCIS (Netherlands)

    Besuijen, J.; Spenkelink, G.P.J.

    1998-01-01

    The current ISO 9241–3 standard for visual display quality and the proposed user performance tests are reviewed. The standard is found to be more engineering than ergonomic and problems with system configuration, software applications, display settings, user behaviour, wear and physical environment

  19. Visual merchandising window display

    Directory of Open Access Journals (Sweden)

    Opris (Cas. Stanila M.

    2013-12-01

    Full Text Available Window display plays a major part in the selling strategies; it does not only include the simple display of goods, nowadays it is a form of art, also having the purpose of sustaining the brand image. This article wants to reveal the tools that are essential in creating a fabulous window display. Being a window designer is not an easy job, you have to always think ahead trends, to have a sense of colour, to know how to use light to attract customers in the store after only one glance at the window. The big store window displays are theatre scenes: with expensive backgrounds, special effects and high fashion mannequins. The final role of the displays is to convince customers to enter the store and trigger the purchasing act which is the final goal of the retail activity.

  20. Thermoacoustically driven refrigerator with double thermoacoustic-Stirling cycles

    Science.gov (United States)

    Luo, Ercang; Dai, Wei; Zhang, Yong; Ling, Hong

    2006-02-01

    Recently, considerable research efforts have been made to search substitution technologies for chlorofluorocarbon-based vapor compression cycles due to the concern over environmental issues. This letter introduces a helium-based thermoacoustic refrigeration system, which is a thermoacoustic-Stirling refrigerator driven by a thermoacoustic-Stirling heat engine, for domestic refrigeration purpose. In the regenerators of both the refrigerator and the prime mover, helium gas experiences near to reversible high efficiency Stirling process. At the operating point with 3.0MPa mean pressure, 57.7Hz frequency, and 2.2kW heat input, the experimental cooler provides a lowest temperature of -64.4°C and 250W cooling power at -22.1°C. These results show good potential of the system to be an alternative in near future for domestic refrigeration with advantages of environment-friendliness, no moving parts, and heat driven mechanism.

  1. Simulation of Thermodynamics Aspects about Pulse Tube Refrigerator

    Science.gov (United States)

    Hozumi, Yoshikazu; Shiraishi, Masao; Murakami, Masahide

    2004-06-01

    In order to investigate the heat transfer mechanism inside a pulse tube refrigerator, CFD has been applied to simulate the working gas behavior. Three dimensional compressible Navier-Stokes equations with viscous dissipation have been solved. Heat conduction between the working gas and the tube metal solids are incorporated into the simulation. A Stirling cycle refrigerator has been also simulated to validate the heat transfer mechanism of the pulse tube refrigerator. However, there is a distinctive heat transfer from the cold end to the hot end of pulse tube, the pulse tube works as a gas displacer to induce a phase shift. The heat transfer of pulse tube refrigerator is caused by the same mechanism of Stirling cycle refrigerator. Additionally, thermal convection at an inclined pulse tube on the angle less than horizontal installation is investigated to show simulation capability of the three dimensional modeling.

  2. Japanese Refrigerators : A Field Performance Analysis : Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Short, John A.

    1990-02-01

    The Pacific Northwest Electric Power Planning and Conservation Act, signed into law December 5, 1980, mandated regionwide energy conservation practices. Under the Act, BPA must identify and implement cost-effective electric energy options and programs for the Pacific Northwest. The Residential Technology Section in the Division of Resource Management supports current residential energy conservation programs and designs and conducts various research and development projects, of which this project is one. Laboratory test procedures used by the Japanese had shown their refrigerators to be about 50 percent more efficient than American-made refrigerators. A previous BPA study tested 12 Japanese refrigerators according to the USDOE laboratory procedure. When tested to the DOE procedure, Japanese refrigerators used about 43 percent more energy than when tested by the Japanese procedure. This study compared in-home energy use of 12 Japanese refrigerators identical to those in the laboratory test to both the Japanese and USDOE laboratory tests. 7 refs., 9 tabs.

  3. Application of magnetic refrigeration and its assessment - Annual report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Kitanovski, A.; Vuarnoz, D.; Diebold, M.; Gonin, C.; Egolf, P. W.

    2007-07-01

    This annual report for the Swiss Federal Office of Energy (SFOE) takes a look at the work done in 2007 at the University of Applied Sciences of Western Switzerland on a project involving refrigeration based on magnetic effects. Possible refrigeration technologies and the evaluation of the potential of magnetic refrigeration are discussed. A calculation tool developed to determine the coefficient of performance (COP) values and the exergy efficiency as a function of magnetic field strength and rotational frequency for rotary types of magnetic refrigerators is introduced. Two applications that are considered to be very interesting for initial research, namely a household refrigerator without a freezing compartment and a large-size central chilling unit are discussed. The COP values of such large-scale systems are commented on. The study of the use of even superconducting magnets is considered as being an economic solution.

  4. EVALUATION OF OZONE-FRIENDLY HYDROFLUOROPROPANE-BASED ZEOTROPIC REFRIGERANT MIXTURES IN A LORENZ-MEUTZNER REFRIGERATOR/FREEZER

    Science.gov (United States)

    The two-evaporator (located in the freezer and fresh food compartments) design of the Lorenz-Meutzner (L-M) refrigerator/freezer (R/F) makes it a leading candidate for use of zeotropic refrigerant mixtures. Zeotrophic mixtures can have significant temperature glides during evapor...

  5. Miniaturized Air-to-Refrigerant Heat Exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Radermacher, Reinhard [Univ. of Maryland, College Park, MD (United States); Bacellar, Daniel [Univ. of Maryland, College Park, MD (United States); Aute, Vikrant [Univ. of Maryland, College Park, MD (United States); Huang, Zhiwei [Univ. of Maryland, College Park, MD (United States); Hwang, Yunho [Univ. of Maryland, College Park, MD (United States); Ling, Jiazhen [Univ. of Maryland, College Park, MD (United States); Muehlbauer, Jan [Univ. of Maryland, College Park, MD (United States); Tancabel, James [Univ. of Maryland, College Park, MD (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhang, Mingkan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-05-23

    Air-to-refrigerant Heat eXchangers (HX) are an essential component of Heating, Ventilation, Air-Conditioning, and Refrigeration (HVAC&R) systems, serving as the main heat transfer component. The major limiting factor to HX performance is the large airside thermal resistance. Recent literature aims at improving heat transfer performance by utilizing enhancement methods such as fins and small tube diameters; this has lead to almost exhaustive research on the microchannel HX (MCHX). The objective of this project is to develop a miniaturized air-to-refrigerant HX with at least 20% reduction in volume, material volume, and approach temperature compared to current state-of-the-art multiport flat tube designs and also be capable of production within five years. Moreover, the proposed HX’s are expected to have good water drainage and should succeed in both evaporator and condenser applications. The project leveraged Parallel-Parametrized Computational Fluid Dynamics (PPCFD) and Approximation-Assisted Optimization (AAO) techniques to perform multi-scale analysis and shape optimization with the intent of developing novel HX designs whose thermal-hydraulic performance exceeds that of state-of-the-art MCHX. Nine heat exchanger geometries were initially chosen for detailed analysis, selected from 35+ geometries which were identified in previous work at the University of Maryland, College Park. The newly developed optimization framework was exercised for three design optimization problems: (DP I) 1.0kW radiator, (DP II) 10kW radiator and (DP III) 10kW two-phase HX. DP I consisted of the design and optimization of 1.0kW air-to-water HX’s which exceeded the project requirements of 20% volume/material reduction and 20% better performance. Two prototypes for the 1.0kW HX were prototyped, tested and validated using newly-designed airside and refrigerant side test facilities. DP II, a scaled version DP I for 10kW air-to-water HX applications, also yielded optimized HX designs

  6. Microlaser-based displays

    Science.gov (United States)

    Bergstedt, Robert; Fink, Charles G.; Flint, Graham W.; Hargis, David E.; Peppler, Philipp W.

    1997-07-01

    Laser Power Corporation has developed a new type of projection display, based upon microlaser technology and a novel scan architecture, which provides the foundation for bright, extremely high resolution images. A review of projection technologies is presented along with the limitations of each and the difficulties they experience in trying to generate high resolution imagery. The design of the microlaser based projector is discussed along with the advantage of this technology. High power red, green, and blue microlasers have been designed and developed specifically for use in projection displays. These sources, in combination with high resolution, high contrast modulator, produce a 24 bit color gamut, capable of supporting the full range of real world colors. The new scan architecture, which reduces the modulation rate and scan speeds required, is described. This scan architecture, along with the inherent brightness of the laser provides the fundamentals necessary to produce a 5120 by 4096 resolution display. The brightness and color uniformity of the display is excellent, allowing for tiling of the displays with far fewer artifacts than those in a traditionally tiled display. Applications for the display include simulators, command and control centers, and electronic cinema.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-08-30

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

  8. Color Display Design Guide

    Science.gov (United States)

    1978-10-01

    and G. M. Corso , "Color flcsearch for Visuz’l Displays, Technical Report No. ONH-CR2l3-102-3, July 1975, 108 pp. 45 1 Results of two code comparison...respective- ly. Since the display elements constitute routine or non-priority informatica , all display information would be coded green if the three-color...1963, with Amendment 1, 30 September 1971. U.S. Government Printing Office: Washington, DC. 27. Christ, R.E. and G.M. Corso . "Color Research for Visual

  9. Small - Display Cartography

    DEFF Research Database (Denmark)

    Nissen, Flemming; Hvas, Anders; Münster-Swendsen, Jørgen

    This report comprises the work carried out in the work-package of small display cartography. The work-package has aimed at creating a general framework for the small-display cartography. A solid framework facilitates an increased use of spatial data in mobile devices - thus enabling, together...... Service Communication and finally, Part IV: Concluding remarks and topics for further research on small-display cartography. Part II includes a separate Appendix D consisting of a cartographic design specification. Part III includes a separate Appendix C consisting of a schema specification, a separate...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

    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.

  11. Savoirs mondains, savoirs savants : les femmes et leurs cabinets de curiosités au siècle des Lumières

    Directory of Open Access Journals (Sweden)

    Adeline Gargam

    2010-01-01

    Full Text Available Dans la France des Lumières, la culture de la curiosité est un phénomène de mode mais surtout un jeu social et intellectuel. La présente étude entend retracer l’histoire d’une trentaine de cabinets féminins de curiosité tenus à cette époque. Des femmes fortunées de l’aristocratie et de la bourgeoisie parisienne et provinciale ont alors constitué sous l’emprise de leur libido sciendi des cabinets d’alchimie, de minéralogie, de physique‑chimie, d’histoire naturelle et d’anatomie naturelle et artificielle. Ces cabinets obéissent à une typologie particulière. Il en existe deux catégories : les cabinets d’amateurs, constitués pour la parade et le spectacle des visiteurs et fonctionnant comme de véritables écoles de plaisirs intellectuels et éducatifs ; les cabinets à finalité scientifique et didactique, formés par des savantes expérimentées qui se livrent dans leurs laboratoires à des recherches personnelles et expérimentales au nom des progrès de la science médicale et de l’instruction publique. La réflexion porte aussi sur le fonctionnement de ces cabinets privés de curiosité, particulièrement sur leur mode de constitution, leur décor intérieur ainsi que sur le contenu des collections qui nécessitaient certaines techniques d’organisation, d’acquisition et de conservation communes à celles de leurs homologues masculins.During the Enlightenment in France, curiosity culture constituted both a fashion and an intellectual and social game.  This article explores thirty cabinets of  curiosities run by women during this period. Wealthy women from the Parisiain and provincial aristocracy and middle classes organized cabinets in alchemy, mineralogy, physics and chemistry, natural history and biology studies. These cabinets can be divided into two distinct categories. The first represented amateur interests; they were developed for show and served as schools for intellectual and

  12. Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1987 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, Edward C.

    1988-05-01

    Estimated kokanee Oncorhynchus nerka abundance in Lake Pend Oreille was 6.01 million during late summer 1987. This estimate is 40% higher than the 1986 estimate and is the second largest population estimate since 1977. Higher abundance is predominantly a result of enhanced fry survival and recruitment. Hatchery-reared fry contribution was 22% of total fry recruitment in 1987, compared to 8% in 1986, and resulted from a fivefold increase in survival. Much of this improvement can be attributed to the large (52 mm) fry produced at Cabinet Gorge Hatchery in 1987 and represents the first measurable contribution of the new hatchery to the kokanee rehabilitation program. Survival of hatchery-reared fry released into Clark Fork River was nearly one-half that of fry released into Sullivan Springs due to poor flow conditions and potentially high predation during migration from Cabinet Gorge Hatchery to Lake Pend Oreille. Wild fry survival was enhanced by early availability of forage (cladocern zooplankton) during fry emergence in late spring. Cladoceran production began three weeks earlier in 1987 than 1986, which resulted from reduced Mysis abundance and earlier thermal stratification of Lake Pend Oreille, which helped segregate cladocerans from mysid predation. Kokanee dry otolith coding was evaluated to provide a reliable long-term mark. Analysis of daily growth increments on otoliths was used successfully in 1987 to differentiate fry from various release sites. The technique will be refined during 1988 to include coding fry otoliths with water temperature fluctuations during hatchery residence. 23 refs., 20 figs., 2 tabs.

  13. Map display design

    Science.gov (United States)

    Aretz, Anthony J.

    1990-01-01

    This paper presents a cognitive model of a pilot's navigation task and describes an experiment comparing a visual momentum map display to the traditional track-up and north-up approaches. The data show the advantage to a track-up map is its congruence with the ego-centered forward view; however, the development of survey knowledge is hindered by the inconsistency of the rotating display. The stable alignment of a north-up map aids the acquisition of survey knowledge, but there is a cost associated with the mental rotation of the display to a track-up alignment for ego-centered tasks. The results also show that visual momentum can be used to reduce the mental rotation costs of a north-up display.

  14. Compressive light field displays.

    Science.gov (United States)

    Wetzstein, Gordon; Lanman, Douglas; Hirsch, Matthew; Heidrich, Wolfgang; Raskar, Ramesh

    2012-01-01

    Light fields are the multiview extension of stereo image pairs: a collection of images showing a 3D scene from slightly different perspectives. Depicting high-resolution light fields usually requires an excessively large display bandwidth; compressive light field displays are enabled by the codesign of optical elements and computational-processing algorithms. Rather than pursuing a direct "optical" solution (for example, adding one more pixel to support the emission of one additional light ray), compressive displays aim to create flexible optical systems that can synthesize a compressed target light field. In effect, each pixel emits a superposition of light rays. Through compression and tailored optical designs, fewer display pixels are necessary to emit a given light field than a direct optical solution would require.

  15. Flexible displays, rigid designs?

    DEFF Research Database (Denmark)

    Hornbæk, Kasper

    2015-01-01

    Rapid technological progress has enabled a wide range of flexible displays for computing devices, but the user experience--which we're only beginning to understand--will be the key driver for successful designs....

  16. ENERGY STAR Certified Displays

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 7.0 ENERGY STAR Program Requirements for Displays that are effective as of July 1, 2016....

  17. Advanced aerosense display interfaces

    Science.gov (United States)

    Hopper, Darrel G.; Meyer, Frederick M.

    1998-09-01

    High-resolution display technologies are being developed to meet the ever-increasing demand for realistic detail. The requirement for evermore visual information exceeds the capacity of fielded aerospace display interfaces. In this paper we begin an exploration of display interfaces and evolving aerospace requirements. Current and evolving standards for avionics, commercial, and flat panel displays are summarized and compared to near term goals for military and aerospace applications. Aerospace and military applications prior to 2005 up to UXGA and digital HDTV resolution can be met by using commercial interface standard developments. Advanced aerospace requirements require yet higher resolutions (2560 X 2048 color pixels, 5120 X 4096 color pixels at 85 Hz, etc.) and necessitate the initiation of discussion herein of an 'ultra digital interface standard (UDIS)' which includes 'smart interface' features such as large memory and blazingly fast resizing microcomputer. Interface capacity, IT, increased about 105 from 1973 to 1998; 102 more is needed for UDIS.

  18. Liquid Crystal Airborne Display

    Science.gov (United States)

    1977-08-01

    with the drive capability of the present state-of-the- art microm.ziiaturized integi ated circuits. The impact of microminiaturizing the drive circuits...7 Advantages /Disadvantages of Prior Art .........- 8 Performance of the Liquid Crystal Matrix Display . . .. 8 Liquid Crystal...Holographic HUD Light Source ...................... .... 99 Design of a Special Purpose Mercury Art - Plo.?hcr La np . 104 V LARGE SCALE INTEGRATION FOR DISPLAY

  19. Military display performance parameters

    Science.gov (United States)

    Desjardins, Daniel D.; Meyer, Frederick

    2012-06-01

    The military display market is analyzed in terms of four of its segments: avionics, vetronics, dismounted soldier, and command and control. Requirements are summarized for a number of technology-driving parameters, to include luminance, night vision imaging system compatibility, gray levels, resolution, dimming range, viewing angle, video capability, altitude, temperature, shock and vibration, etc., for direct-view and virtual-view displays in cockpits and crew stations. Technical specifications are discussed for selected programs.

  20. ORFeome Phage Display.

    Science.gov (United States)

    Zantow, Jonas; Moreira, Gustavo Marçal Schmidt Garcia; Dübel, Stefan; Hust, Michael

    2018-01-01

    ORFeome phage display allows the efficient functional screening of entire proteomes or even metaproteomes to identify immunogenic proteins. For this purpose, randomly fragmented, whole genomes or metagenomes are cloned into a phage-display vector allowing positive selection for open reading frames (ORF) to improve the library quality. These libraries display all possible proteins encoded by a pathogen or a microbiome on the phage surface. Consequently, immunogenic proteins can be selected from these libraries using disease-related immunoglobulins from patient serum. ORFeome phage display in particular allows the identification of immunogenic proteins that are only expressed in the host-pathogen interaction but not in cultivation, as well as the detection of very low expressed and very small immunogens and immunogenic proteins of non-cultivable organisms. The identified immunogenic proteins are potential biomarkers for the development of diagnostic assays or vaccines. These articles will give an introduction to ORFeome phage-display technology and give detailed protocols to identify immunogenic proteins by phage display.

  1. Energy Efficiency and Environmental Impact Analyses of Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-01-01

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

  2. Compatibility of refrigerants and lubricants with engineering plastics. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C.

    1993-12-01

    23 plastics have been subjected to immersion studies using 7 different lubricants at 60 C and 100 C, and 10 different refrigerants at ambient and 60 C. In the first part of the study, 22 hermetic stress crack-creep rupture test chambers were used to determine dynamic effects of a constant dead weight load on plastic test bars immersed at 20 C in a 40% refrigerant 32 ISOVG branched acid polyolester lubricant. The creep modulus data of the 10 refrigerants, using a dead weight load of 25% of ultimate tensile, are compared to values for air and HCFC-22. In the second part, the plastic test bars were aged for 14 d at constant refrigerant pressure 300 psia with 17 refrigerant lubricant combinations at 150 C. Additional evaluations were conducted to elucidate the effects of temperature, refrigerant, and lubricant on the plastics. At 150 C, high acid formation (high TAN) was further examined with dehydrated plastics. These evaluations indicate that dehydrating the plastics reduced, but did not eliminate, high TAN values and that heat alone caused the lost physicals. Alternative HFC refrigerants had little impact on plastics; some polyolester lubricants caused identifiable changes.

  3. Copper Oxide Nanoparticles for Advanced Refrigerant Thermophysical Properties: Mathematical Modeling

    Directory of Open Access Journals (Sweden)

    S. A. Fadhilah

    2014-01-01

    Full Text Available In modern days, refrigeration systems are important for industrial and domestic applications. The systems consume more electricity as compared to other appliances. The refrigeration systems have been investigated thoroughly in many ways to reduce the energy consumption. Hence, nanorefrigerant which is one kind of nanofluids has been introduced as a superior properties refrigerant that increased the heat transfer rate in the refrigeration system. Many types of materials could be used as the nanoparticles to be suspended into the conventional refrigerants. In this study, the effect of the suspended copper oxide (CuO nanoparticles into the 1,1,1,2-tetrafluoroethane, R-134a is investigated by using mathematical modeling. The investigation includes the thermal conductivity, dynamic viscosity, and heat transfer rate of the nanorefrigerant in a tube of evaporator. The results show enhanced thermophysical properties of nanorefrigerant compared to the conventional refrigerant. These advanced thermophysical properties increased the heat transfer rate in the tube. The nanorefrigerant could be a potential working fluid to be used in the refrigeration system to increase the heat transfer characteristics and save the energy usage.

  4. 77 FR 10291 - Energy Conservation Program: Test Procedure for Commercial Refrigeration Equipment

    Science.gov (United States)

    2012-02-21

    ... consumption of commercial freezers specifically designed for ice-cream application. 71 FR 71357 (Dec. 8, 2006... industrial equipment, which includes commercial refrigerators, freezers, and refrigerator-freezers, the...- contained commercial refrigerators, freezers, and refrigerator- freezers with solid or transparent doors...

  5. 7 CFR 3300.37 - Testing of a mechanical refrigerating appliance.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Testing of a mechanical refrigerating appliance. 3300... SPECIAL EQUIPMENT Procedures for Separate Testing of Mechanical Refrigerating Appliances § 3300.37 Testing of a mechanical refrigerating appliance. For separate testing of a mechanical refrigerating appliance...

  6. Nonconvex Model Predictive Control for Commercial Refrigeration

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F.S.; Jørgensen, John Bagterp

    2013-01-01

    is to minimize the total energy cost, using real-time electricity prices, while obeying temperature constraints on the zones. We propose a variation on model predictive control to achieve this goal. When the right variables are used, the dynamics of the system are linear, and the constraints are convex. The cost......We consider the control of a commercial multi-zone refrigeration system, consisting of several cooling units that share a common compressor, and is used to cool multiple areas or rooms. In each time period we choose cooling capacity to each unit and a common evaporation temperature. The goal...... savings, on the order of 30%, compared to a standard thermostat-based control system. Perhaps more important, we see that the method exhibits sophisticated response to real-time variations in electricity prices. This demand response is critical to help balance real-time uncertainties in generation...

  7. Coefficient of performance of Stirling refrigerators

    Science.gov (United States)

    E Mungan, Carl

    2017-09-01

    Stirling coolers transfer heat in or out of the working fluid during all four stages of their operation, and their coefficient of performance depends on whether the non-isothermal heat exchanges are performed reversibly or irreversibly. Both of these possibilities can in principle be arranged. Notably, if the working fluid is an ideal gas, the input of energy in the form of heat during one isochoric step is equal in magnitude to the output during the other isochoric step in the cycle. The theoretical performance of the fridge can then attain the reversible Carnot limit if a regenerator is used, which is a high heat capacity material through which the gas flows. Various Stirling refrigerator configurations are analysed in this article at a level of presentation suitable for an introductory undergraduate thermodynamics course.

  8. Advanced Refrigerator/Freezer Technology Development Project

    Science.gov (United States)

    Cairelli, James E.; Geng, Steven M.

    1999-01-01

    The Advanced Refrigerator/Freezer (R/F) Technology Development Project was initiated in 1994, on the basis of recommendations of a team of NASA Scientists and engineers, who assessed the need for advanced technology to support future life and biomedical sciences space flight missions. The project, which was cofunded by NASA's Office of Aerospace Technology and Life and Biomedical Sciences & Applications Division, has two phases. In the Phase I Advanced R/F Technology Assessment, candidate technologies were identified and ranked, on the basis of a combination of their effect on system performance and their risk of developmental success. In Phase II Technology Development, the advanced technologies with the highest combined ranking, which could be accomplished within the budgetary constraints, were pursued. The effort has been mainly by contract, with a modest in-house effort at the NASA Lewis Research Center. Oceaneering Space Systems (OSS) of Houston, Texas, was selected as the prime contractor for both contract phases.

  9. The lifetime cost of a magnetic refrigerator

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian R.H.; Nielsen, Kaspar Kirstein

    2016-01-01

    The total cost of a 25 W average load magnetic refrigerator using commercial grade Gd is calculated using a numerical model. The price of magnetocaloric material, magnet material and cost of operation are considered, and all influence the total cost. The lowest combined total cost with a device......, the optimal magnetic field is about 1.4 T, the particle size is 0.23 mm, the length of the regenerator is 40-50 mm and the utilization is about 0.2, for all device lifetimes and material and magnet prices, while the operating frequency vary as function of device lifetime. The considered performance...... lifetime of 15 years is found to be in the range $150-$400 depending on the price of the magnetocaloric and magnet material. The cost of the magnet is largest, followed closely by the cost of operation, while the cost of the magnetocaloric material is almost negligible. For the lowest cost device...

  10. Information rich display design

    Energy Technology Data Exchange (ETDEWEB)

    Welch, Robin; Braseth, Alf Ove; Veland, Oeystein

    2004-07-01

    This paper presents the concept Information Rich Displays. The purpose of Information Rich Displays (IRDs) is to condensate prevailing information in process displays in such a way that each display format (picture) contains more relevant information for the user. Compared to traditional process control displays, this new concept allows the operator to attain key information at a glance and at the same time allows for improved monitoring of larger portions of the process. This again allows for reduced navigation between both process and trend displays and ease the cognitive demand on the operator. This concept has been created while working on designing display prototypes for the offshore petroleum production facilities of tomorrow. Offshore installations basically consist of wells, separation trains (where oil, gas and water are separated from each other), an oil tax measurement system (where oil quality is measured and the pressure increased to allow for export), gas compression (compression of gas for export) and utility systems (water treatment, chemical systems etc.). This means that an offshore control room operator has to deal with a complex process that comprises several functionally different systems. The need for a new approach to offshore display format design is in particular based on shortcomings in today's designs related to the keyhole effect, where the display format only reveals a fraction of the whole process. Furthermore, the upcoming introduction of larger off- and on-shore operation centres will increase the size and complexity of the operators' work domain. In the light of the increased demands on the operator, the proposed IRDs aim to counter the negative effects this may have on the workload. In this work we have attempted to classify the wide range of different roles an operator can have in different situations. The information content and amount being presented to the operator in a display should be viewed in context of the roles

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

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Smith, Anders; Bahl, Christian Robert Haffenden

    2011-01-01

    An expression is determined for the mass of the magnet and magnetocaloric material needed for a magnetic refrigerator and these are determined using numerical modeling for both parallel plate and packed sphere bed regenerators as function of temperature span and cooling power. As magnetocaloric......, respectively, the cheapest 100 W parallel plate refrigerator with a temperature span of 20 K using Gd and a Halbach magnet has 0.8 kg of magnet, 0.3 kg of Gd and a cost of $35. Using the constant material reduces this cost to $25. A packed sphere bed refrigerator with the constant material costs $7. It is also...

  12. Automatic control study of the icing research tunnel refrigeration system

    Science.gov (United States)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-02-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  13. Automatic control study of the icing research tunnel refrigeration system

    Science.gov (United States)

    Kieffer, Arthur W.; Soeder, Ronald H.

    1991-01-01

    The Icing Research Tunnel (IRT) at the NASA Lewis Research Center is a subsonic, closed-return atmospheric tunnel. The tunnel includes a heat exchanger and a refrigeration plant to achieve the desired air temperature and a spray system to generate the type of icing conditions that would be encountered by aircraft. At the present time, the tunnel air temperature is controlled by manual adjustment of freon refrigerant flow control valves. An upgrade of this facility calls for these control valves to be adjusted by an automatic controller. The digital computer simulation of the IRT refrigeration plant and the automatic controller that was used in the simulation are discussed.

  14. Power Consumption in Refrigeration Systems - Modeling for Optimization

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Skovrup, Morten Juel

    2011-01-01

    Refrigeration systems consume a substantial amount of energy. Taking for instance supermarket refrigeration systems as an example they can account for up to 50−80% of the total energy consumption in the supermarket. Due to the thermal capacity made up by the refrigerated goods in the system...... with possibly multiple extrema. Such a function can not directly be optimized by standard methods and a qualitative analysis of the system’s constraints is presented. The description of power consumption contains nonlinear terms which are approximated by linear functions in the control variables and the error...

  15. Modeling of Pressure Drop During Refrigerant Condensation in Pipe Minichannels

    Science.gov (United States)

    Sikora, Małgorzata; Bohdal, Tadeusz

    2017-12-01

    Investigations of refrigerant condensation in pipe minichannels are very challenging and complicated issue. Due to the multitude of influences very important is mathematical and computer modeling. Its allows for performing calculations for many different refrigerants under different flow conditions. A large number of experimental results published in the literature allows for experimental verification of correctness of the models. In this work is presented a mathematical model for calculation of flow resistance during condensation of refrigerants in the pipe minichannel. The model was developed in environment based on conservation equations. The results of calculations were verified by authors own experimental investigations results.

  16. Performance comparison of a refrigerator system using R134a and hydrocarbon refrigerant (HCR134a) with different expansion devices

    Science.gov (United States)

    Aziz, A.; Izzudin; Mainil, A. K.

    2017-09-01

    The objective of this study is to compare the performance of refrigerator system using working fluid between R134a refrigerant and HCR134a as hydrocarbon refrigerant for substitution of R134a. The use of capillary tube (CT) 1.5 m with HCR134a showed that slightly better COP than among the others, due to the lower pressure of condenser, conversely thermostatic expansion valve (TEV) showed that better COP than among the others with R134a. COP of CT 1.25 m and CT 1.5 m using HCR134a increase about 42.89% and 18.09% compared to R134a, where the electric current of refrigerator system decrease about 11.63% and 10.98%. However, the COP of HCR134a with CT 2.7 m and TEV were obtained lower than R134a about 16.2% and 17.06% and the use of electric current is higher than R134a about 12.98% and 16.5%. The use of HCR134a provides a higher refrigeration effect than R134a about 66.71%-88.27% for various types of expansion devices. The results confirmed that HCR134a could be an alternative refrigerant for replacement of R134a refrigerant.

  17. Dynamic plasmonic colour display

    Science.gov (United States)

    Duan, Xiaoyang; Kamin, Simon; Liu, Na

    2017-01-01

    Plasmonic colour printing based on engineered metasurfaces has revolutionized colour display science due to its unprecedented subwavelength resolution and high-density optical data storage. However, advanced plasmonic displays with novel functionalities including dynamic multicolour printing, animations, and highly secure encryption have remained in their infancy. Here we demonstrate a dynamic plasmonic colour display technique that enables all the aforementioned functionalities using catalytic magnesium metasurfaces. Controlled hydrogenation and dehydrogenation of the constituent magnesium nanoparticles, which serve as dynamic pixels, allow for plasmonic colour printing, tuning, erasing and restoration of colour. Different dynamic pixels feature distinct colour transformation kinetics, enabling plasmonic animations. Through smart material processing, information encoded on selected pixels, which are indiscernible to both optical and scanning electron microscopies, can only be read out using hydrogen as a decoding key, suggesting a new generation of information encryption and anti-counterfeiting applications. PMID:28232722

  18. Stereo Painting Display Devices

    Science.gov (United States)

    Shafer, David

    1982-06-01

    The Spanish Surrealist artist Salvador Dali has recently perfected the art of producing two paintings which are stereo pairs. Each painting is separately quite remarkable, presenting a subject with the vivid realism and clarity for which Dali is famous. Due to the surrealistic themes of Dali's art, however, the subjects preser.ted with such naturalism only exist in his imagination. Despite this considerable obstacle to producing stereo art, Dali has managed to paint stereo pairs that display subtle differences of coloring and lighting, in addition to the essential perspective differences. These stereo paintings require a display method that will allow the viewer to experience stereo fusion, but which will not degrade the high quality of the art work. This paper gives a review of several display methods that seem promising in terms of economy, size, adjustability, and image quality.

  19. THE RESULTS OF THE STUDY BOILING POINT OUT OZONE-SAFE REFRIGERANT R410A IN THE EVAPORATORS OF REFRIGERATING MACHINES

    Directory of Open Access Journals (Sweden)

    V. G. Bukin

    2012-01-01

    Full Text Available The results of experimental research boiling heat transfer of ozone-friendly R410A refrigerant in evaporators machines and the possibility of its use in place of the prohibited refrigerant R22.

  20. Experimental study on neon refrigeration system using commercial helium compressor

    Science.gov (United States)

    Ko, Junseok; Kim, Hyobong; Hong, Yong-Ju; Yeom, Hankil; Koh, Deuk-Yong; Park, Seong-Je

    2012-06-01

    In this study, we developed neon refrigeration system using commercial helium compressor which was originally designed for GM cryocooler. We performed this research as precedent study before developing neon refrigeration system for small-scale hydrogen liquefaction system. The developed system is based on precooled Linde-Hampson system with liquid nitrogen as precoolant. Design parameters of heat exchangers are determined from thermodynamic cycle analysis with operating pressure of 2 MPa and 0.4 MPa. Heat exchangers have concentric-tube heat exchanger configuration and orifice is used as Joule- Thomson expansion device. In experiments, pressure, temperature, mass flow rate and compressor input power are measured as charging pressure. With experimental results, the characteristics of heat exchanger, Joule-Thomson expansion and refrigeration effect are discussed. The developed neon refrigeration system shows the lowest temperature of 43.9 K.

  1. Non-linear and adaptive control of a refrigeration system

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Larsen, Lars F. S.

    2011-01-01

    In a refrigeration process heat is absorbed in an evaporator by evaporating a flow of liquid refrigerant at low pressure and temperature. Controlling the evaporator inlet valve and the compressor in such a way that a high degree of liquid filling in the evaporator is obtained at all compressor...... are capable of adapting to variety of systems. This paper proposes a novel method for superheat and capacity control of refrigeration systems; namely by controlling the superheat by the compressor speed and capacity by the refrigerant flow. A new low order nonlinear model of the evaporator is developed...... capacities ensures a high energy efficiency. The level of liquid filling is indirectly measured by the superheat. Introduction of variable speed compressors and electronic expansion valves enables the use of more sophisticated control algorithms, giving a higher degree of performance and just as important...

  2. A theoretical and experimental study of a novel refrigerant compressor

    OpenAIRE

    I. W. Eames

    1989-01-01

    The aim of this thesis is to evaluate the findings of research undertaken into the design manufacture and testing of a novel refrigeration compressor for use in packaged air conditioner units of the type used in railway passenger transport systems.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-01

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

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

    Science.gov (United States)

    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.

  5. An overview of adsorptive processes in refrigeration systems

    Directory of Open Access Journals (Sweden)

    Wolak Eliza

    2016-01-01

    Full Text Available Economic reasons and quest for new solutions based on recovering the energy have provoked an increase of interest in the adsorption technology in the refrigeration industry. The confirmation can be the fact that number of published research is on rise. Adsorption appliances may turn out to be an alternative to compression-type coolers. They use ecological chemical agents instead of substances which are aggressive and harmful to the environment. For regeneration of adsorptive refrigeration systems one can use cheap energy in a form of: industrial waste heat, energy of solar radiation and cheap electric power. The paper presents principles of operation as well as advantages and disadvantages of adsorptive refrigeration systems. Basing on literature the most frequently used adsorbent – adsorbate systems – which are employed in refrigeration industry – have been characterized. A review of construction solutions of systems on both laboratory and industrial scale has been made.

  6. Thermodynamic Analysis of the Irreversibilities in Solar Absorption Refrigerators

    Directory of Open Access Journals (Sweden)

    Emma Berrich Betouche

    2016-03-01

    Full Text Available A thermodynamic analysis of the irreversibility on solar absorption refrigerators is presented. Under the hierarchical decomposition and the hypothesis of an endoreversible model, many functional and practical domains are defined. The effect of external heat source temperature on the entropy rate and on the inverse specific cooling load (ISCL multiplied by the total area of the refrigerator A/Qe are studied. This may help a constructor to well dimension the solar machine under an optimal technico-economical criterion A/Qe and with reasonable irreversibility on the refrigerator. The solar concentrator temperature effect on the total exchanged area, on the technico-economical ratio A/Qe, and on the internal entropy rate are illustrated and discussed. The originality of these results is that they allow a conceptual study of a solar absorption refrigeration cycle.

  7. Zero-ODP Refrigerants for Low Tonnage Centrifugal Chiller Systems

    National Research Council Canada - National Science Library

    Gui, Fulin

    1996-01-01

    ..., HFC-236cb, HFC-236fa, HFC-245cb, and HFC-254cb, for centrifugal chiller applications. We took into account the thermodynamic properties of the refrigerant and aerodynamic properties of the impeller compression process to this evaluation...

  8. Study on Operating Characteristics of A House Hold Stirling Refrigerator

    Science.gov (United States)

    Otaka, Toshio; Sakamoto, Moriyoshi; Murakami, Kazuhiko; Ota, Masahiro

    A prototype Stirling cycle refrigerator employing helium as a working fluid has been investigated to see whether the freon free machine be a viable alternative for the current household refrigerator. The prototype is a kinematics drive, and β type Stirling cycle machine of 100W refrigeration. The performance was evaluated as a function of cooling head temperature, mean pressure, frequency, and cooling capacity. The prototype has achieved the targeted refrigeration of 100W, and the COP of 1.02 under the design operation condition; 16.7Hz frequency and 0.7MPa helium pressure. The performance data was compared with the predicted ones, which was obtained by the 3rd order computational method. It has been demonstrated that the performance is in a good agreement with the predicted in the whole range of operation condition.

  9. Magnesium Diboride Superconducting Coils for Adiabatic Demagnetization Refrigerators (ADR's) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For Adiabatic Demagnetization Refrigerators(ADR's) for space it is desirable to have very light weight, small diameter, high current density superconducting wires...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-07

    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.

  11. REVIEW OF ENERGY EFFICIENCY OF REFRIGERATOR/FREEZER GASKETS

    Science.gov (United States)

    The report gives results of an investigation of the significance of heat leakage through gaskets in household refrigerator/freezers, explores different design features, and suggests further study if necessary. The report gives results of an extensive literature review, interviews...

  12. Analysis of synchronization in a supermarket refrigeration system

    DEFF Research Database (Denmark)

    Wisniewski, Rafal; Leth, John-Josef; Rasmussen, Jakob Gulddahl

    2014-01-01

    increases both the energy consumption and the wear of components. Besides this practical importance, from the theoretical point of view, synchronization, likewise stability, Zeno phenomenon, and chaos, is an interesting dynamical phenomenon. The study of synchronization in the supermarket refrigeration...

  13. Transitioning to Low-GWP Alternatives in Domestic Refrigeration

    Science.gov (United States)

    This fact sheet provides information on low-GWP alternatives in newly manufactured domestic refrigeration equipment. It discusses HFC alternatives, market trends, challenges to market entry for alternatives, and potential solutions.

  14. REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures

    Science.gov (United States)

    SRD 73 NIST REFLEAK: NIST Leak/Recharge Simulation Program for Refrigerant Mixtures (PC database for purchase)   REFLEAK estimates composition changes of zeotropic mixtures in leak and recharge processes.

  15. Optimization of refrigeration system with gas-injected scroll compressor

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Baolong; Shi, Wenxing; Han, Linjun; Li, Xianting [Department of Building Science, Tsinghua University, Beijing 100084 (China)

    2009-11-15

    Gas refrigerant injection has been proven as an effective method to improve the performance of the scroll compressor and its refrigeration system under high compression ratio working conditions. Much research on the injected scroll compressor and its system has been conducted, but the universal control and design method is still lacking. A model of the refrigeration system with a gas-injected scroll compressor is developed in this paper. With this model, the effects of gas injection on the system and component parameters are investigated. Based on the identified evaporator characteristics and thermodynamic analysis, a set of general principles for the design and operation of the refrigeration or heat pump system with a gas-injected scroll compressor is proposed. (author)

  16. Performance improvement clarification for refrigeration system using active system monitoring

    DEFF Research Database (Denmark)

    Green, Torben; Niemann, Hans Henrik; Izadi-Zamanabadi, Roozbeh

    2011-01-01

    This paper addresses the problem of determining whether a refrigeration plant has the possibility of delivering a better performance of the operation. The controllers are wellknown but detailed knowledge about the underlying dynamics of the refrigeration plant is not available. Thus, the question...... is if it is possible to achieve a better performance by changing the controller parameter. An approach to active system monitoring, based on active fault diagnosis techniques, is employed in order to evaluate changes in the system performance under operation....

  17. Magnetic refrigeration with paramagnetic semiconductors at cryogenic temperatures

    Science.gov (United States)

    Vlasov, Alexander; Guillemette, Jonathan; Gervais, Guillaume; Szkopek, Thomas

    2017-10-01

    We propose paramagnetic semiconductors as active media for refrigeration at cryogenic temperatures by adiabatic demagnetization. The paramagnetism of impurity dopants or structural defects can provide the entropy necessary for refrigeration at cryogenic temperatures. We present a simple model for the theoretical limitations to specific entropy and cooling power achievable by demagnetization of various semiconductor systems. Performance comparable to that of the commonly used paramagnetic salt cerous magnesium nitrate hydrate is predicted.

  18. Refreshing Refreshable Braille Displays.

    Science.gov (United States)

    Russomanno, Alexander; O'Modhrain, Sile; Gillespie, R Brent; Rodger, Matthew W M

    2015-01-01

    The increased access to books afforded to blind people via e-publishing has given them long-sought independence for both recreational and educational reading. In most cases, blind readers access materials using speech output. For some content such as highly technical texts, music, and graphics, speech is not an appropriate access modality as it does not promote deep understanding. Therefore blind braille readers often prefer electronic braille displays. But, these are prohibitively expensive. The search is on, therefore, for a low-cost refreshable display that would go beyond current technologies and deliver graphical content as well as text. And many solutions have been proposed, some of which reduce costs by restricting the number of characters that can be displayed, even down to a single braille cell. In this paper, we demonstrate that restricting tactile cues during braille reading leads to poorer performance in a letter recognition task. In particular, we show that lack of sliding contact between the fingertip and the braille reading surface results in more errors and that the number of errors increases as a function of presentation speed. These findings suggest that single cell displays which do not incorporate sliding contact are likely to be less effective for braille reading.

  19. Effect of evaporator temperature on vapor compression refrigeration system

    Directory of Open Access Journals (Sweden)

    Abdullah A.A.A. Al-Rashed

    2011-12-01

    Full Text Available This paper presents a comparable evaluation of R600a (isobutane, R290 (propane, R134a, R22, for R410A, and R32 an optimized finned-tube evaporator, and analyzes the evaporator effect on the system coefficient of performance (COP. Results concerning the response of a refrigeration system simulation software to an increase in the amount of oil flowing with the refrigerant are presented. It is shown that there is optima of the apparent overheat value, for which either the exchanged heat or the refrigeration coefficient of performance (COP is maximized: consequently, it is not possible to optimize both the refrigeration COP and the evaporator effect. The obtained evaporator optimization results were incorporated in a conventional analysis of the vapor compression system. For a theoretical cycle analysis without accounting for evaporator effects, the COP spread for the studied refrigerants was as high as 11.7%. For cycle simulations including evaporator effects, the COP of R290 was better than that of R22 by up to 3.5%, while the remaining refrigerants performed approximately within a 2% COP band of the R22 baseline for the two condensing temperatures considered.

  20. SBIR Grant:No-Vibration Agile Cryogenic Optical Refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Epstein, Richard

    2013-04-09

    Optical refrigeration is currently the only all-solid-state cryocooling technology that has been demonstrated. Optical cryocoolers are devices that use laser light to cool small crystal or glass cooling elements. The cooling element absorbs the laser light and reradiates it at higher energy, an example of anti-Stokes fluorescence. The dif-ference between the energy of the outgoing and incoming light comes from the thermal energy of the cooling element, which in turn becomes colder. Entitled No-Vibration Agile Cryocoolers using Optical Refrigeration, this Phase I proposal directly addressed the continued development of the optical refrigerator components necessary to transition this scientific breakthrough into National Nu-clear Security Administration (NNSA) sensor applications in line with the objectives of topic 50b. ThermoDynamic Films LLC (TDF), in collaboration with the University of New Mexico (UNM), cooled an optical-refrigerator cooling element comprised of an ytterbium-doped yttrium lithium fluoride (Yb:YLF) crystal from room tempera-ture to 123 K with about 2% efficiency. This is the world record in optical refrigera-tion and an important step toward revolutionizing cryogenic systems for sensor ap-plications. During this period, they also designed and analyzed the crucial elements of a prototype optical refrigerator including the thermal link that connects the cool-ing element with the load.

  1. Field Testing and Modeling of Supermarket Refrigeration Systems as a Demand Response Resource

    Energy Technology Data Exchange (ETDEWEB)

    Deru, Michael; Hirsch, Adam; Clark, Jordan; Anthony, Jamie

    2016-08-26

    Supermarkets offer a substantial demand response (DR) resource because of their high energy intensity and use patterns; however, refrigeration as the largest load has been challenging to access. Previous work has analyzed supermarket DR using heating, ventilating, and air conditioning; lighting; and anti-sweat heaters. This project evaluated and quantified the DR potential inherent in supermarket refrigeration systems in the Bonneville Power Administration service territory. DR events were carried out and results measured in an operational 45,590-ft2 supermarket located in Hillsboro, Oregon. Key results from the project include the rate of temperature increase in freezer reach-in cases and walk-ins when refrigeration is suspended, the load shed amount for DR tests, and the development of calibrated models to quantify available DR resources. Simulations showed that demand savings of 15 to 20 kilowatts (kW) are available for 1.5 hours for a typical store without precooling and for about 2.5 hours with precooling using only the low-temperature, non-ice cream cases. This represents an aggregated potential of 20 megawatts within BPA's service territory. Inability to shed loads for medium-temperature (MT) products because of the tighter temperature requirements is a significant barrier to realizing larger DR for supermarkets. Store owners are reluctant to allow MT case set point changes, and laboratory tests of MT case DR strategies are needed so that owners become comfortable testing, and implementing, MT case DR. The next-largest barrier is the lack of proper controls in most supermarket displays over ancillary equipment, such as anti-sweat heaters, lights, and fans.

  2. SIMULATION OF NON-AZEOTROPIC REFRIGERANT MIXTURES FOR USE IN A DUAL-CIRCUIT REFRIGERATOR/FREEZER WITH COUNTERCURRENT HEAT EXCHANGES

    Science.gov (United States)

    The paper discusses a refrigerator/freezer (RF) system that has two complete and independent refrigeration cycles for the two compartments. It uses a non-azeotropic refrigerant mixture (NARM) in each cycle and countercurrent heat exchangers throughout. This RF is housed in a stan...

  3. 78 FR 25724 - Petition for Waiver of GE Appliances From the Department of Energy Residential Refrigerator and...

    Science.gov (United States)

    2013-05-02

    ... is developing new refrigerator- freezers that incorporate a dual-compressor design that is not... Energy Residential Refrigerator and Refrigerator-Freezer Test Procedure and Grant of Interim Waiver... energy consumption of electric refrigerators and refrigerator-freezers. GE asks that it be permitted to...

  4. New Regenerative Cycle for Vapor Compression Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Bergander

    2005-08-29

    second step of compression. In the proposed system, the compressor compresses the vapor only to 50-60% of the final pressure, while the additional compression is provided by a jet device using internal potential energy of the working fluid flow. Therefore, the amount of mechanical energy required by a compressor is significantly reduced, resulting in the increase of efficiency (either COP or EER). The novelty of the cycle is in the equipment and in the way the multi-staging is accomplished. The anticipated result will be a new refrigeration system that requires less energy to accomplish a cooling task. The application of this technology will be for more efficient designs of: (1) Industrial chillers, (2) Refrigeration plants, (3) Heat pumps, (4) Gas Liquefaction plants, (5) Cryogenic systems.

  5. Challenges in recovery and recycling of refrigerants from Indian refrigeration and air-conditioning service sector

    Science.gov (United States)

    Devotta, Sukumar; Asthana, Saroja; Joshi, Rahul

    India is a large producer and user of chlorofluorocarbons (CFCs) in the refrigeration and air-conditioning (RAC) sector. Government of India has taken several steps to restrict the production and consumption of CFCs. Refrigerant conservation through recovery, recycling (R&R) and reclamation is one way of reducing emissions and encouraging timely phase out of CFCs in developing countries. CFC recovery, recycling and reclamation have been mandated in many developed countries. However, this practice is yet to make an impact in India although it is practiced in MAC sector to some extent. India is planning for the final phase out of CFCs in the RAC service sector, in which R&R will be one of the components. A model has been developed to assess the economics of R&R for some typical parameters in developing counties like India. The model suggests that the enterprises recycling 1500 kg/a will break even within 1 year for all scenarios. However, R&R may not be cost effective for small workshops and low volume refrigerant vendors until either the price of CFC goes up or the cost of R&R unit is subsidized. A nationwide survey on RAC service sector revealed that in India, there are very few enterprises handling more than 500 kg/a. Therefore, there is a need to provide the RAC service sector with adequate and innovative financial incentives. This paper attempts to study the issues related to R&R for various sub-sectors of RAC in developing countries with an emphasis on cost effectiveness. India is used as a model for this study.

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

    Science.gov (United States)

    Ecker, Amir L.

    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.

  7. Hatchery Spray Cabinet Administration Does Not Damage Avian Coronavirus Infectious Bronchitis Virus Vaccine Based on Analysis by Electron Microscopy and Virus Titration.

    Science.gov (United States)

    Roh, Ha-Jung; Jordan, Brian J; Hilt, Deborah A; Ard, Mary B; Jackwood, Mark W

    2015-03-01

    studies in our laboratory showed that the Arkansas-Delmarva Poultry Industry (Ark-DPI) vaccine given to 1-day-old chickens by hatchery spray cabinet replicated poorly and failed to adequately protect broilers against homologous virus challenge, whereas the same vaccine given by eye-drop did replicate and the birds were protected following homologous virus challenge. To determine if mechanical damage following spray application plays a role in failure of the Ark-DPI vaccine, we examined the morphology of three Ark-DPI vaccines from different manufacturers using an electron microscope and included a Massachusetts (Mass) vaccine as control. One of the Ark-DPI vaccines (vaccine A) and the Mass vaccine had significantly (P hatchery spray cabinet, suggesting that some other factor is contributing to the failure of that vaccine when given by that method.

  8. Influence of Oil on Refrigerant Evaporator Performance

    Science.gov (United States)

    Jong-Soo, Kim; Nagata, Katsuya; Katsuta, Masafumi; Tomosugi, Hiroyuki; Kikuchi, Kouichiro; Horichi, Toshiaki

    To explore the quantitative effect of the lubrication oil on the thermal and hydraulic evaporator performance, the detailed structure of two-phase refrigerant (R11) and lubrication oil (Suniso 5GS) flow has been investigated. Experiment has been performed using a transparent tube 20mm in inner diameter and 2600mm in total length as main test section, which was heated by surrounding hot water bath. This water bath also functioned as the visual observation section of the transition of two-phase flow pattern. Oil mass concentration was controlled initially, and circulated into the system. The void fraction at the main test section was measured by direct volume measurement using so-called "Quick Closing Valve" method. Since the effect of oil on the transition of two-phase flow pattern is emphasized at the low flow rate, operation was made at relatively low mass velocity, 50 and 100 kg/m2·s, five different oil concentrations were taken. Throughout the experiment, the evaporation pressure was kept at 105 kPa. In general, when contamination of the lubrication oil happened, the void fraction was decreasing due to the change of viscosity and surface tension and the occurence of the foaming. To correlate the void fraction as function of quality, Zivi's expression was modified to include the effect of oil concentration. The agreement between the data and this proposed correlation was favorable. Finally, to take into account the effect of lubrication oil, the new flow pattern diagram was proposed.

  9. Tactical Video Display.

    Science.gov (United States)

    1981-02-01

    designed to extend the state-of-the-art in the area of thin film electroluminescent display systems. The program entails two major areas of efforts...the inclusion of the residual gases in thin film is very likely and dependent upon the concentrations of the gases and the reactive nature of the...reproducible films . Some exploratory work was also performed on the feasitility of applying a ZnTe /Te system black layer with TFEL structure. Pre

  10. Attention-Seeking Displays.

    Directory of Open Access Journals (Sweden)

    Szabolcs Számadó

    Full Text Available Animal communication abounds with extravagant displays. These signals are usually interpreted as costly signals of quality. However, there is another important function for these signals: to call the attention of the receiver to the signaller. While there is abundant empirical evidence to show the importance of this stage, it is not yet incorporated into standard signalling theory. Here I investigate a general model of signalling - based on a basic action-response game - that incorporates this searching stage. I show that giving attention-seeking displays and searching for them can be an ESS. This is a very general result and holds regardless whether only the high quality signallers or both high and low types give them. These signals need not be costly at the equilibrium and they need not be honest signals of any quality, as their function is not to signal quality but simply to call the attention of the potential receivers. These kind of displays are probably more common than their current weight in the literature would suggest.

  11. Kokanee Stock Status and Contribution of Cabinet Gorge Hatchery, Lake Pend Oreille, Idaho, 1986 Annual Progress Report.

    Energy Technology Data Exchange (ETDEWEB)

    Bowles, Edward C.

    1987-02-01

    Estimated kokanee (Oncorhynchus nerka) abundance in Lake Pend Oreille was 4.3 million during September 1986. This estimate was similar to 1985 and indicates continued suppression of the kokanee population since initial decline in the late 1960s. Atypically high survival of wild fry resulted in similar fry recruitment in 1986 as 1985, whereas hatchery-reared fry contributed only 8% to total fry recruitment as a result of low post-release survival (3%). Fry released into the Clark Fork River from Cabinet Gorge Hatchery had very low survival during emigration to Lake Pend Oreille, resulting from poor flow conditions and potentially high predation. Fry survival during emigration was twice as high during nighttime flows of 16,000 cfs than 7,800 cfs. Emigration also was faster during higher flows. Several marks were tested to differentially mark fry release groups to help determine impacts of flow and other factors on fry survival. Survival of fry marked with tetracycline and fluorescent dye was high (>99%) during the 10-week study. In contrast, survival of fry marked with fluorescent grit marks ranged from 5 to 93%, depending on application pressure and distance from the fry. Retention was high (>96%) for tetracycline and grit marks during the study, whereas dye marks were discernible (100%) for only one week. 23 refs., 20 figs., 10 tabs.

  12. Stage Cylindrical Immersive Display

    Science.gov (United States)

    Abramyan, Lucy; Norris, Jeffrey S.; Powell, Mark W.; Mittman, David S.; Shams, Khawaja S.

    2011-01-01

    Panoramic images with a wide field of view intend to provide a better understanding of an environment by placing objects of the environment on one seamless image. However, understanding the sizes and relative positions of the objects in a panorama is not intuitive and prone to errors because the field of view is unnatural to human perception. Scientists are often faced with the difficult task of interpreting the sizes and relative positions of objects in an environment when viewing an image of the environment on computer monitors or prints. A panorama can display an object that appears to be to the right of the viewer when it is, in fact, behind the viewer. This misinterpretation can be very costly, especially when the environment is remote and/or only accessible by unmanned vehicles. A 270 cylindrical display has been developed that surrounds the viewer with carefully calibrated panoramic imagery that correctly engages their natural kinesthetic senses and provides a more accurate awareness of the environment. The cylindrical immersive display offers a more natural window to the environment than a standard cubic CAVE (Cave Automatic Virtual Environment), and the geometry allows multiple collocated users to simultaneously view data and share important decision-making tasks. A CAVE is an immersive virtual reality environment that allows one or more users to absorb themselves in a virtual environment. A common CAVE setup is a room-sized cube where the cube sides act as projection planes. By nature, all cubic CAVEs face a problem with edge matching at edges and corners of the display. Modern immersive displays have found ways to minimize seams by creating very tight edges, and rely on the user to ignore the seam. One significant deficiency of flat-walled CAVEs is that the sense of orientation and perspective within the scene is broken across adjacent walls. On any single wall, parallel lines properly converge at their vanishing point as they should, and the sense of

  13. Handbook of Visual Display Technology

    CERN Document Server

    Cranton, Wayne; Fihn, Mark

    2012-01-01

    The Handbook of Visual Display Technology is a unique work offering a comprehensive description of the science, technology, economic and human interface factors associated with the displays industry. An invaluable compilation of information, the Handbook will serve as a single reference source with expert contributions from over 150 international display professionals and academic researchers. All classes of display device are covered including LCDs, reflective displays, flexible solutions and emissive devices such as OLEDs and plasma displays, with discussion of established principles, emergent technologies, and particular areas of application. The wide-ranging content also encompasses the fundamental science of light and vision, image manipulation, core materials and processing techniques, display driving and metrology.

  14. Activity of citrus essential oils against Escherichia coli O157:H7 and Salmonella spp. and effects on beef subprimal cuts under refrigeration.

    Science.gov (United States)

    Pittman, Curtis I; Pendleton, Sean; Bisha, Bledar; O'Bryan, Corliss A; Belk, Keith E; Goodridge, Lawrence; Crandall, Philip G; Ricke, Steven C

    2011-08-01

    Escherichia coli O157:H7 and Salmonella spp. are bacterial pathogens often associated with beef, and cause many cases of foodborne illness each year in the United States. During beef slaughter and processing, these bacteria may spread from the hide or intestines to the carcass. The objective of this research was to investigate the use of naturally occurring compounds citrus essential oils (CEOs) extracted from orange peel to reduce or eliminate these pathogens at the chilling stage of processing, or during fabrication. Brisket flats (used to simulate beef subprimals) were spot inoculated with approximately 6 log of surrogate generic E. coli cocktail (previously shown to be identical in growth and survival parameters to E. coli O157:H7 and Salmonella spp.). Following drying, CEOs were applied by spraying at concentrations of 3% and 6% to the surface of different pieces of meat. Treatments were applied using a custom built spray cabinet at 2.07 bar and applied at a rate of 3.79 L/min to replicate commercial practices. The CEOs significantly reduced (P refrigerated storage stage of processing. CEOs are natural compounds that have been designated as Generally Recognized as Safe (GRAS). They can be used to control Salmonella spp. and E. coli O157:H7 on beef carcasses at the chilling stage. © 2011 Institute of Food Technologists®

  15. Active Cooling for Downhole Instrumentation: Miniature Thermoacoustic Refrigerator.

    Science.gov (United States)

    Bennett, Gloria Adame

    1991-02-01

    A miniature active cooling system capable of providing multi-watt refrigeration for thermally protecting downhole instruments used in hot geothermal wells is researched, developed and designed. The engineering design process is used to develop design criteria and design constraints and to select potential refrigeration processes. A literature search identifies nine physical and chemical processes and twenty six systems appropriate for a feasibility study. Each refrigeration process is investigated to search for suitable high temperature components and a refrigerant, thereby eliminating only three processes and nine systems. Consistent analysis of an ideal thermodynamic cycle for each of the six remaining refrigeration processes further reduces the choices to three processes and seven systems. Final selection requires consideration of refrigerator and geothermal logging system thermal, mechanical and electrical interactions to define failure modes, insure compatibility with existing hardware, and allow adaptability to changes in design criteria. Results of calculations from postulated design criteria changes provide insight into design simplicity and data for further selection. A decision model is constructed and used to organize design constraints and criteria and sort out those useful for making a final selection. Final selection is based on maximizing system simplicity and providing graceful degradation in case of refrigerator failure. The consistent design, systematic analysis and unbiased selection process represent a body of research results that is new to this technology and provides a potential for advance not realized to date. The selected thermoacoustic process and the designed refrigeration system are analyzed in detail, with numerical models constructed for each subsystem, and component and for the component interactions. The thermoacoustic wave equation is extended to allow sloped rather than parallel acoustic plates. This extension increases acoustic

  16. OPTIMAL SYSNTHESIS PROCESSES OF LOW-TEMPERATURE CONDENSATION ASSOCIATED OIL GAS PLANT REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    O. Ostapenko

    2015-10-01

    Full Text Available Design of modern high-efficient systems is a key priority for the Energy Sector of Ukraine. The cooling technological streams of gas and oil refineries, including air coolers, water cooling and refrigeration systems for specific refrigerants are the objectives of the present study. Improvement of the refrigeration unit with refrigerant separation into fractions is mandatory in order to increase cooling capacity, lowering the boiling point of coolant and increasing the coefficient of target hydrocarbons extraction from the associated gas flow. In this paper it is shown that cooling temperature plays significant role in low-temperature condensation process. Two operation modes for refrigeration unit were proposed: permanent, in which the concentration of the refrigerant mixture does not change and dynamic, in which the concentration of refrigerant mixtures depends on the ambient temperature. Based on the analysis of exergy losses the optimal concentration of refrigerant mixtures propane/ethane for both modes of operation of the refrigeration unit has been determined. On the basis of the conducted pinch-analysis the modification of refrigeration unit with refrigerant separation into fractions was developed. Additional recuperative heat exchangers for utilization heat were added to the scheme. Several important measures to increase the mass flow rate of refrigerant through the second section of the refrigeration centrifugal compressor from 22.5 to 25 kg/s without violating the agreed operational mode of the compressor sections were implemented.

  17. Performance of diffusion absorption refrigeration cycle with organic working fluids

    Energy Technology Data Exchange (ETDEWEB)

    Zohar, A.; Jelinek, M.; Levy, A.; Borde, I. [Pearlstone Center for Aeronautical Engineering Studies, Mechanical Engineering Department, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel)

    2009-09-15

    A diffusion absorption refrigeration (DAR) cycle is driven by heat and utilizes a binary solution of refrigerant and absorbent as working fluid, together with an auxiliary inert gas. Commercial DAR systems operate with ammonia-water solution and hydrogen or helium as the inert gas. In this work, the performance of a simplified DAR system working with an organic absorbent (DMAC - dimethylacetamide) and five different refrigerants and helium as inert gas was examined numerically, with the aim of lowering the generator temperature and system pressure along with a non-toxic refrigerant The refrigerants were: chlorodifluoromethane (R22), difluoromethane (R32), 2-chloro-1,1,1,2-tetrafluoroethane (R124), pentafluoroethane (R125) and 1,1,1,2-tetrafluoroethane (R134a). The results were compared with the performance of the same system working with ammonia-water and helium. Similar behavior was found for all systems, regarding the coefficient of performance (COP) and rich and poor solution concentrations as functions of generator temperature. It was found that typical generator temperature with the new substances was 150 C, yet lower COPs, higher evaporator temperatures and lower condensation temperature of about 40 C governed these systems. (author)

  18. Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

    Directory of Open Access Journals (Sweden)

    Zi-Jie Chien

    2013-01-01

    Full Text Available This experiment is to study an absorption refrigerator driven by solar cells. Hand-held or carried in vehicle can be powered by solar energy in places without power. In the evenings or rainy days, it is powered by storage battery, and it can be directly powered by alternating current (AC power supply if available, and the storage battery can be charged full as a backup supply. The proposed system was tested by the alternation of solar irradiance 550 to 700 W/m2 as solar energy and 500ml ambient temperature water as cooling load. After 160 minutes, the proposal refrigerator can maintain the temperature at 5–8°C, and the coefficient of performance (COP of NH3-H2O absorption refrigeration system is about 0.25. Therefore, this system can be expected to be used in remote areas for refrigeration of food and beverages in outdoor activities in remote and desert areas or long-distance road transportation of food or low temperature refrigeration of vaccine to avoid the deterioration of the food or the vaccines.

  19. Dilution Refrigeration of Multi-Ton Cold Masses

    CERN Document Server

    Wikus, P; CERN. Geneva

    2007-01-01

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

  20. Image Descriptors for Displays

    Science.gov (United States)

    1977-02-01

    the entire display could be changed as often as every 1/60 s (TV field rate). Scan interlace was not used on the monitor. The 1/60-s resolution of...of photons arriving at the retina. These contributions can be separated by examining the experimental mT(v) as a function of luminance. From... photon shot noise, was found to be negligible for luminance .al.•- above 4 iabout 10 mL. Thus, the function A(v) represents the m4(v) employed in the

  1. Refrigeration and air-conditioning technology workshop

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, P. J.; Counce, D. M. [eds.

    1993-01-01

    The Alternative Fluorocarbon Environmental Acceptability Study (AFEAS), a consortium of fluorocarbon manufacturers, and the US Department of Energy (DOE) are collaborating on a project to evaluate the energy use and global warming impacts of CFC alternatives. The goal of this project is to identify technologies that could replace the use of CFCs in refrigeration, heating, and air-conditioning equipment; to evaluate the direct impacts of chemical emissions on global warming; and to compile accurate estimates of energy use and, indirect CO{sub 2} emissions of substitute technologies. The first phase of this work focused on alternatives that could be commercialized before the year 2000. The second phase of the project is examining not-in-kind and next-generation technologies that could be developed to replace CFCs, HCFCs, and HFCs over a longer period. As part of this effort, Oak Ridge National Laboratory held a workshop on June 23--25, 1993. The preliminary agenda covered a broad range of alternative technologies and at least one speaker was invited to make a brief presentation at the workshop on each technology. Some of the invited speakers were unable to participate, and in a few cases other experts could not be identified. As a result, those technologies were not represented at the workshop. Each speaker was asked to prepare a five to seven page paper addressing six key issues concerning the technology he/she is developing. These points are listed in the sidebar. Each expert also spoke for 20 to 25 minutes at the workshop and answered questions from the other participants concerning the presentation and area of expertise. The primary goal of the presentations and discussions was to identify the developmental state of the technology and to obtain comparable data on system efficiencies. Individual papers are indexed separately.

  2. Optical refrigeration for ultra-efficient photovoltaics

    Science.gov (United States)

    Manor, Assaf; Martin, Leopoldo L.; Rotschild, Carmel

    2015-03-01

    The Shockley-Queisser (SQ) efficiency limit for single-junction photovoltaic cell (PV) is to a great extent due to inherent heat dissipation accompanying the quantum process of electro-chemical potential generation. Concepts such as solar thermophotovoltaics1,2,3 (STPV) and thermo-photonics4 aim to harness this dissipated heat, claiming very high theoretical limit. In practice, none of these concepts have been experimentally proven to overcome the SQ limit, mainly due to the very high operating temperatures, which significantly challenge electro-optical devices. In contrast to the above concepts for harnessing thermal emission at thermal equilibrium, Photoluminescence (PL) is a fundamental light-matter interaction under non-thermal equilibrium, which conventionally involves the absorption of energetic photon, thermalization and the emission of a red-shifted photon. Conversely, in optical-refrigeration the absorption of low energy photon is followed by endothermic-PL of energetic photon5,6. Both aspects were mainly studied where thermal population is far weaker than photonic excitation, obscuring the generalization of PL and thermal emissions. Here we experimentally study endothermic-PL at high temperatures7. In accordance with theory, we show how PL photon rate is conserved with temperature increase, while each photon is blue shifted. Further rise in temperature leads to an abrupt transition to thermal emission where the photon rate increases sharply. We also show how endothermic-PL generates orders of magnitude more energetic photons than thermal emission at similar temperatures. Relying on these observations, we propose and study thermally enhanced PL (TEPL) for highly efficient solar-energy conversion. Here, solar radiation is absorbed by a low-bandgap PL material. The dissipated heat is emitted by endothermic PL, and harvested by a higher-bandgap photovoltaic cell. While such device operates at much lower temperatures than STPV, the theoretical efficiencies

  3. Improving the system of absorption unit refrigeration

    Directory of Open Access Journals (Sweden)

    Pokhol'chenko V. A.

    2016-12-01

    Full Text Available The problems of improving the absorption stove cooling system for high quality liquid smoke producing have been discussed in the paper. There is absorption stove construction presented which includes absorber, heat exchanger, low-temperature chamber, ultrasound radiator, and water spray generator. The data on the color depending of the experimental liquid smoke on main factors influencing the process – the coolant temperature and amount of fuel burned – have been presented. The specific surface of the fuel mass fraction of water in the fuel has been determined according to standard procedures. Transparency, color and intensity of staining smoke fluid have been determined organoleptically. The liquid smoke according to the requirements of the current normative documents on safety performance indicators has been tested by standard methods: determination of benzo(apyrene, phenol compounds and heavy metals. The equation for estimation the complex quality criterion of experimental liquid smoke on the basis of its chemical composition has been presented. The main factors influencing the complex quality criteria of experimental liquid smoke have been given there. They include the sound pressure level, amount of wood raw material required for pyrolysis, heat exchanging surface, refrigerant temperature, and ultrasound water spray generator efficiency. After processing the experimental data the regression equation of producing liquid smoke by absorption has been received. With the help of the mathematical modeling for absorption process of smoke components by fine-dispersed spray the rational parameters of liquid smoke processing have been founded. The project of technological instructions for the liquid smoke production by using the wood smoke and acoustically generated aerosol has been designed. The project of technical requirement "Liquid smoke Antonio Silver" has been designed as well; it has been tested at producing the commercial batch of dried

  4. Nonconvex model predictive control for commercial refrigeration

    Science.gov (United States)

    Gybel Hovgaard, Tobias; Boyd, Stephen; Larsen, Lars F. S.; Bagterp Jørgensen, John

    2013-08-01

    We consider the control of a commercial multi-zone refrigeration system, consisting of several cooling units that share a common compressor, and is used to cool multiple areas or rooms. In each time period we choose cooling capacity to each unit and a common evaporation temperature. The goal is to minimise the total energy cost, using real-time electricity prices, while obeying temperature constraints on the zones. We propose a variation on model predictive control to achieve this goal. When the right variables are used, the dynamics of the system are linear, and the constraints are convex. The cost function, however, is nonconvex due to the temperature dependence of thermodynamic efficiency. To handle this nonconvexity we propose a sequential convex optimisation method, which typically converges in fewer than 5 or so iterations. We employ a fast convex quadratic programming solver to carry out the iterations, which is more than fast enough to run in real time. We demonstrate our method on a realistic model, with a full year simulation and 15-minute time periods, using historical electricity prices and weather data, as well as random variations in thermal load. These simulations show substantial cost savings, on the order of 30%, compared to a standard thermostat-based control system. Perhaps more important, we see that the method exhibits sophisticated response to real-time variations in electricity prices. This demand response is critical to help balance real-time uncertainties in generation capacity associated with large penetration of intermittent renewable energy sources in a future smart grid.

  5. Painting Reproductions on Display

    Directory of Open Access Journals (Sweden)

    Joanna Iranowska

    2017-09-01

    Full Text Available Paintings in museums might occasionally be replaced by a photoprint mimicking the original. This article is an investigation of what constitutes a good reproduction of an artwork (oil painting that is meant to be displayed. The article discusses what the usefulness of reproductions depends on, applying the Valuation Studies approach, which means the primary concern is with the practice of valuing itself. In other words, the study focuses on how museum experts evaluate reproduc-tions of oil paintings. The article analyses three cases of displaying digitally prin-ted copies of Edvard Munch's oil paintings between 2013 and 2015 in the Munch Museum and in the National Gallery in Oslo. The study is based on a series of semi-structured interviews with the experts, working at and for the museums, that were involved in producing and exhibiting of the photoprints: curators, con-servators, museum educators, and external manufacturers. The interviews were grouped into five clusters, which I have chosen to call registers of valuing following Frank Heuts and Annemarie Mol (2013. The described valuation practices have to do with delivering experiences to the public, obtaining mimetic resemblance, solving ethical aspects, exhibitions' budget, and last but not least, with the time perspective.

  6. 10 CFR Appendix A1 to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Electric Refrigerators and Electric...

    Science.gov (United States)

    2010-01-01

    ... incorporated into the design of a refrigerator or refrigerator-freezer to prevent the accumulation of moisture... of Electric Refrigerators and Electric Refrigerator-Freezers A1 Appendix A1 to Subpart B of Part 430... the Energy Consumption of Electric Refrigerators and Electric Refrigerator-Freezers 1. Definitions 1.1...

  7. Experimental investigation of R-134a and R-600a refrigerant blend ...

    African Journals Online (AJOL)

    GWP) ≤ 150 according to the European Union protocol, alongside other properties, which no single refrigerant has met as at today. This study focused on blending of existing refrigerants towards obtaining blends with GWP ≤ 150.

  8. Appendix E: Supplemental Risk Management Program Guidance for Ammonia Refrigeration Facilities

    Science.gov (United States)

    Additional information for food processors, food distributors, refrigerated warehouses, and any other facility that has an ammonia refrigeration system. Includes details on exemption for farms, threshold quantity, and offsite consequence analysis.

  9. 75 FR 59469 - Energy Conservation Program: Energy Conservation Standards for Residential Refrigerators...

    Science.gov (United States)

    2010-09-27

    ... IV. Methodology and Discussion A. Market and Technology Assessment 1. Exclusion of Wine Coolers From... revisions, product classes (including wine coolers, all- refrigerators,\\7\\ and built-in refrigeration...

  10. Review and comparison of magnet designs for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus; Bahl, Christian Robert Haffenden; Smith, Anders

    2010-01-01

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

  11. A Case Study of a Low Powervapour Compression Refrigeration System

    Science.gov (United States)

    Abinav, R.; Nambiar, G. K.; Sahu, Debjyoti

    2016-09-01

    Reported in this paper is a case study on a normal vapor compression refrigeration system which is expected to be run by photovoltaic panels to utilize minimum grid power. A small 120 W refrigerator is fabricated out of commercially available components and run by an inverter and battery connected to solar photovoltaic panel as well as grid. Temperature at several points was measured and the performance was evaluated. The Coefficient of performance (COP) to run such refrigerator is estimated after numerical simulation of major components namely, evaporator, condenser and a capillary tube. The simulation was done to obtain an effective cooling temperature and the results were compared with measured temperatures. Calculation proves to be in conformity with the actual model.

  12. Compounds produced by motor burnouts of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Koester, C.; Hawley-Fedder, R.; Foiles, L.

    1995-05-24

    The phase-out of chlorofluorocarbons has necessitated the introduction of alternate refrigerants. R22 (CF{sub 2}ClH), R134a (CF{sub 3}CH{sub 2}F), and R507 (50/50 CHF{sub 2}CF{sub 3}/CF{sub 3}CH{sub 3}) are newer fluids which are used in cooling systems. Recently, concern over the possible formation of toxic compounds during electrical arcing through these fluids has prompted us to identify their electrical breakdown products by electron ionization GC/MS. For example, it is known that perfluoroisobutylene (PFIB), which have an threshold limit value of 10 ppb (set by the American Conference of Government Industrial Hygienists), is produced from the thermal and electrical breakdown of some refrigerants. We have used specially designed test cells, equipped with electrodes, to simulate the electrical breakdown of R22, R134a, and R507 in refrigeration systems.

  13. Conference on Refrigeration for Cryogenic Sensors and Electronic Systems

    CERN Document Server

    Sullivan, D B; McCarthy, S E; Cryogenic Refrigeration Conference; International Cryocooler Conference; Cryocoolers 1

    1981-01-01

    This proceedings documents the output of a meeting of refrigeration specialists held at the National Bureau of Standards, Boulder, CO, on October 6 and 7, 1980. Building on an earlier invitation-only meeting in 1977, the purpose of this first open meeting was to discuss progress in the development of refrigeration systems to cool cryogenic sensors and electronic systems in the temperature range below 20 K and with required cooling capacities below 10 W. The meeting was jointly sponsored by the International Institute of Refrigeration - Commission A1/2, the Office of Naval Research, the Naval Research Laboratory, the Cryogenic Engineering Conference, and the National Bureau of Standards. This first open cryocooler conference consisted of 23 papers presented by representatives of industry, government, and academia. The conference proceedings reproduced here was published by the National Bureau of Standards in Boulder, Colorado as NBS Special Publication #607. Subsequent meetings would become known as the Intern...

  14. Alternatives to ozone depleting refrigerants in test equipment

    Science.gov (United States)

    Hall, Richard L.; Johnson, Madeleine R.

    1995-01-01

    This paper describes the initial results of a refrigerant retrofit project at the Aerospace Guidance and Metrology Center (AGMC) at Newark Air Force Base, Ohio. The objective is to convert selected types of test equipment to properly operate on hydrofluorocarbon (HFC) alternative refrigerants, having no ozone depleting potential, without compromising system reliability or durability. This paper discusses the primary technical issues and summarizes the test results for 17 different types of test equipment: ten environmental chambers, two ultralow temperature freezers, two coolant recirculators, one temperature control unit, one vapor degreaser, and one refrigerant recovery system. The postconversion performance test results have been very encouraging: system capacity and input power remained virtually unchanged. In some cases, the minimum operating temperature increased by a few degrees as a result of the conversion, but never beyond AGMC's functional requirements.

  15. Frost sensor for use in defrost controls for refrigeration

    Science.gov (United States)

    French, Patrick D.; Butz, James R.; Veatch, Bradley D.; O'Connor, Michael W.

    2002-01-01

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

  16. Electron refrigeration in hybrid structures with spin-split superconductors

    Science.gov (United States)

    Rouco, M.; Heikkilä, T. T.; Bergeret, F. S.

    2018-01-01

    Electron tunneling between superconductors and normal metals has been used for an efficient refrigeration of electrons in the latter. Such cooling is a nonlinear effect and usually requires a large voltage. Here we study the electron cooling in heterostructures based on superconductors with a spin-splitting field coupled to normal metals via spin-filtering barriers. The cooling power shows a linear term in the applied voltage. This improves the coefficient of performance of electron refrigeration in the normal metal by shifting its optimum cooling to lower voltage, and also allows for cooling the spin-split superconductor by reverting the sign of the voltage. We also show how tunnel coupling spin-split superconductors with regular ones allows for a highly efficient refrigeration of the latter.

  17. Determining minimal display element requirements for surface map displays

    Science.gov (United States)

    2003-04-14

    There is a great deal of interest in developing electronic surface map displays to enhance safety and reduce incidents and incursions on or near the airport surface. There is a lack of research, however, detailing the minimal display elements require...

  18. Demand Response Opportunities in Industrial Refrigerated Warehouses in California

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Development of a low noise 10K J-T refrigeration system

    Science.gov (United States)

    Little, William A.

    1990-10-01

    The development of a low noise, Joule-Thomson, microminiature refrigeration system is summarized. Progress was made on the development of the pneumatic compressor drive system which will be used to operate the compressor to determine the compressor lifetime and refrigerator system performance. Work on the refrigerator itself also has progressed well with operation down to 20 K now being achieved, and reliably reproduced. Work is underway on the heat exchanger section of the third stage of the refrigerator, the helium stage.

  20. Temperature control in refrigeration appliances. An Important food safety factor; Kylmaesaeilytyslaitteen laempoetilansaeaetoe. Taerkeae ruoan turvallisuustekijae

    Energy Technology Data Exchange (ETDEWEB)

    Marjomaa, T. [Work Efficiency Inst., Helsinki (Finland)

    2000-07-01

    Critical stages from the point of view of the quality of foods stored refrigerated are refrigerated transportation and excessively warm shop furnishings. The consumer's own refrigeration appliance can also be a problem as the consumer has to adjust its temperature. Temperature control is done using rotating selections of electronically-functioning push-button type of selectors. The TTS Institute has conducted a study looking into the precision of temperature control in the case of seven freezer refrigerations.