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Sample records for electric domestic refrigerators

  1. 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…

  2. Energetic, economic and environmental impacts of using nanorefrigerant in domestic refrigerators in Malaysia

    International Nuclear Information System (INIS)

    Javadi, F.S.; Saidur, R.

    2013-01-01

    Highlights: • Energy saving of using nanorefrigerant except of normal refrigerant in domestic refrigerator is investigated in Malaysia. • Using nanorefrigerant cause to reduce energy consumption of domestic refrigerator. • The maximum energy saving would be happen in case of using 0.1% TiO 2 –mineral oil–R134a nanorefrigerant. • Emission reduction is an environmental effect of using nanorefrigerant. - Abstract: The electricity demand in the residential sector has increased rapidly in recent years in Malaysia. This is mainly due to lifestyle improvement; and is also associated with the increase in the number of domestic refrigerators in this tropical country. This paper investigates the effect of using nanorefrigerant on energy saving in domestic refrigerators and emission reduction of greenhouse gases as an environmental viewpoint. The combination of R-134a refrigerant with TiO 2 and Al 2 O 3 nanoparticles with different mass fractions was scrutinized as a new refrigerant. It has been found that the energy saving using nanorefrigerant (0.1% TiO 2 nanoparticle/Mineral Oil) would be greater than normal refrigerant, with 10,863 MW h reduction in energy consumption by the year 2030. In this regard, this technology will be environmentally friendly by decreasing greenhouse emission, especially in terms of carbon dioxide. Thus, nanorefrigerant can help to increase the performance of domestic refrigerators and reduce energy consumption. Favorable effect on emission reduction and economic justification were concluded

  3. 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 ...

  4. National potential of saving of electricity in domestic refrigeration; Potencial nacional de ahorro de electricidad en refrigeracion domestica

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo C, Fernando [Universidad Nacional Autonoma de Mexico (Mexico); Ambriz G, Juan Jose; Romero P, Hernando [Universidad Autonoma Metropolitana, (Mexico)

    2003-07-01

    In the present paper the evaluation of the potential of saving of electrical energy in Mexico is presented, by means of the substitution of old refrigerators of low efficiency by modern high efficiency ones. This potential is very ample, since the replacement of the old models by new follows a very slow curve, if the economic difficulties of the Mexican families are considered and that, on the other hand, the technology of the domestic refrigerators is so reliable that they have a very long life and they are not easily rejected. In field work have been found refrigerators operating with ages of more than 30 years and still 40. In Mexico, it is estimated that the refrigeration is responsible for around 29% of the of electricity consumption in homes settled in tempered climate and of 14 % in those of warm climate in which air conditioning is used. The proposal of this work is the organization of a governmental program of accelerated substitution of refrigerators that helps to acquire an efficient refrigerator and to reject the old ones. The results indicate that if a total renovation of the park of domestic refrigerators is made, the saving of electrical energy would reach the 5.2 TWh/a which represents the 44.5% of the total consumption of 11.7 TWh in a year. [Spanish] En el presente trabajo se presenta la evaluacion del potencial de ahorro de energia electrica en Mexico, mediante la substitucion de refrigeradores antiguos de baja eficiencia por modernos de alta eficiencia. Este potencial es muy amplio, ya que el reemplazo de los modelos viejos por nuevos sigue una curva muy lenta, si se consideran las dificultades economicas de las familias mexicanas y que, por otro lado, la tecnologia de los refrigeradores domesticos es tan confiable que tienen una vida muy larga y no se desechan facilmente. En trabajos de campo se han encontrado refrigeradores operando con edades de mas de 30 anos y aun 40. En Mexico, se estima que la refrigeracion es responsable de alrededor del

  5. Time-Temperature Profiling of United Kingdom Consumers' Domestic Refrigerators.

    Science.gov (United States)

    Evans, Ellen W; Redmond, Elizabeth C

    2016-12-01

    Increased consumer demand for convenience and ready-to-eat food, along with changes to consumer food purchase and storage practices, have resulted in an increased reliance on refrigeration to maximize food safety. Previous research suggests that many domestic refrigerators operate at temperatures exceeding recommendations; however, the results of several studies were determined by means of one temperature data point, which, given temperature fluctuation, may not be a true indicator of actual continual operating temperatures. Data detailing actual operating temperatures and the effects of consumer practices on temperatures are limited. This study has collated the time-temperature profiles of domestic refrigerators in consumer kitchens (n = 43) over 6.5 days with concurrent self-reported refrigerator usage. Overall, the findings established a significant difference (P < 0.05) between one-off temperature (the recording of one temperature data point) and mean operating temperature. No refrigerator operated at ≤5.0°C for the entire duration of the study. Mean temperatures exceeding 5.0°C were recorded in the majority (91%) of refrigerators. No significant associations or differences were determined for temperature profiles and demographics, including household size, or refrigerator characteristics (age, type, loading, and location). A positive correlation (P < 0.05) between room temperature and refrigerator temperature was determined. Reported door opening frequency correlated with temperature fluctuation (P < 0.05). Thermometer usage was determined to be infrequent. Cumulatively, research findings have established that the majority of domestic refrigerators in consumer homes operate at potentially unsafe temperatures and that this is influenced by consumer usage. The findings from this study may be utilized to inform the development of shelf-life testing based on realistic domestic storage conditions. Furthermore, the data can inform the development of future

  6. Experimental evaluation of the consumption of electrical energy of domestic refrigerators in Mexico; Evaluacion experimental del consumo de energia electrica de refrigeradores domesticos en Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo Cabanas, Fernando Gabriel [Programa de Energia, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Ambriz Garcia, Juan Jose; Paredes Rubio, Hernando Romero [Area de Ingenieria en Recursos Energeticos, Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

    2004-06-15

    In this work the experimental methodology developed to carry out tests of the electrical energy of refrigerators consumption as norm NOM-015-ENER-2002 is described. The tests were made in the Laboratory of Controlled Environment of the Iztapalapa Unit of the Universidad Autonoma Metropolitana to a sample of old domestic refrigerators in operation. The results found show that the consumption of electrical energy of refrigerators of more than 10 years of age can be higher than 60% of what a modern refrigerator of high efficiency would consume, or 30% higher if the refrigerator was made between 1997 and 2002. With these results it is sustained, in a more complete way, the evaluation of the saving potential of the national electrical energy by the substitution of old domestic refrigerators by modern, as reported in a previous work. [Spanish] En este trabajo se describe la metodologia experimental desarrollada para efectuar pruebas del consumo de energia electrica a refrigeradores conforme la norma NOM-015-ENER-2002. Las pruebas se realizaron en el Laboratorio de Ambiente Controlado de la Unidad Iztapalapa de la Universidad Autonoma Metropolitana a una muestra de refrigeradores domesticos antiguos en operacion. Los resultados encontrados muestran que el consumo de energia electrica de refrigeradores de mas de 10 anos de antig�edad puede superior al 60% de lo que consumiria un refrigerador moderno de alta eficiencia, o superior en un 30% si el refrigerador fue fabricado entre 1997 y 2002. Con estos resultados se sustenta de manera mas completa la evaluacion del potencial de ahorro de energia electrica nacional por substitucion de refrigeradores domesticos antiguos por modernos reportado en un trabajo anterior.

  7. Energy shift estimation of demand response activation on domestic refrigerators – A field test study

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Gudmand-Høyer, Kristian; Marinelli, Mattia

    2014-01-01

    This paper presents a method to estimate the amount of energy that can be shifted during demand response (DR) activation on domestic refrigerator. Though there are many methods for DR activation like load reduction, load shifting and onsite generation, the method under study is load shifting....... Electric heating and cooling equipment like refrigerators, water heaters and space heaters and coolers are preferred for such DR activation because of their energy storing capacity. Accurate estimation of available regulating power and energy shift is important to understand the value of DR activation...... at any time. In this paper a novel method to estimate the available energy shift from domestic refrigerators with only two measurements, namely fridge cool chamber temperature and compressor power consumption is proposed, discussed and evaluated....

  8. An experimental investigation on a novel ejector enhanced refrigeration cycle applied in the domestic refrigerator-freezer

    International Nuclear Information System (INIS)

    Wang, Xiao; Yu, Jianlin

    2015-01-01

    This paper presents an experimental investigation on a NERC (novel ejector enhanced refrigeration cycle) applied in the domestic refrigerator-freezer (BCD-249). Experimental studies were conducted to validate the NERC system feasibility in a practical NERC based refrigerator-freezer prototype. The system performances of energy consumption, ejector pressure lift ratio and compressor power were compared under different combinations of system configuration parameters. The results showed that the NERC system could effectively reduce the thermodynamic losses in the throttle processing. The minimum energy consumption of 0.520 kWh 24 h"−"1 was obtained for the NERC prototype, indicating 5.45% energy consumption reduction compared with the conventional domestic refrigerator-freezer. Furthermore, the effects of system configuration parameters including the refrigerant charge amount, the compressor displacement and the length of capillary tube were investigated. This study aims at providing deep insight into ejector-expansion technology applied in domestic refrigerator-freezers. - Highlights: • A NERC (novel ejector enhanced refrigeration cycle) was experimentally studied. • 73 experimental data points with different system configuration were acquired. • Energy consumption could be reduced with optimum system configuration. • 5.45% energy consumption reduction is obtained compared with the conventional system.

  9. Qualitative comparison of duplex Stirling and absorption refrigerators in domestic applications

    Energy Technology Data Exchange (ETDEWEB)

    Shao, H. [Global Cooling BV, Zutphen (Netherlands)

    2000-07-01

    A qualitative comparison has been carried out between the duplex Stirling and the absorption refrigerator for domestic applications. The duplex Stirling has many advantages over the absorption refrigerator on efficiency, modulation, suitability, operating costs, pollution reduction. Based on the state of the art of free-piston gas-bearing and linear-motor Stirling engines and coolers, it appears technically and economically feasible to develop the duplex Stirling to compete with the absorption refrigerator for heat-driven domestic refrigeration. (orig.)

  10. Energy evaluation process of electric domestic refrigerators; Proceso de evaluacion energetica de refrigeradores electrodomesticos

    Energy Technology Data Exchange (ETDEWEB)

    Malacara Toral, Manuel; Ruiz Neblina, Joaquin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1993-12-31

    A description is made of an energy evaluation study on electric domestic refrigerators carried out by the Instituto de Investigaciones Electricas (IIE), in its strategy for diminishing the energy consumption through the design enhancement, the manufacture, the operation and the standardization of the electric appliances. In order to initiate the evaluation-standardization process, the Mexican (NOM), the American (ANSI/AHAM) and the Canadian (CAN/CSA) standards were taken as a base to harmonize the procedures and the parameters of the tests. The energy assessment demonstrated that there are significant differences among the standards encompassed by the study, therefore, recommendations were made for the harmonization of the standards. [Espanol] Se describe un estudio de evaluacion energetica sobre refrigeradores electrodomesticos realizado en el Instituto de Investigaciones Electricas (IIE) dentro de la estrategia para disminuir los consumos de energia a traves de mejoras en el diseno, la manufactura, la operacion y la normalizacion de equipos electricos. Se tomo como base las normas mexicanas (NOM), americana (ANSI/AHAM) y canadiense (CAN/CSA) para iniciar el proceso de evaluacion-normalizacion a fin de armonizar los procedimientos y parametros de las pruebas. La evaluacion energetica demostro que existen diferencias significativas entre las normas que abarco el estudio por lo que se presentan recomendaciones para la armonizacion de las normas.

  11. Energy evaluation process of electric domestic refrigerators; Proceso de evaluacion energetica de refrigeradores electrodomesticos

    Energy Technology Data Exchange (ETDEWEB)

    Malacara Toral, Manuel; Ruiz Neblina, Joaquin [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-12-31

    A description is made of an energy evaluation study on electric domestic refrigerators carried out by the Instituto de Investigaciones Electricas (IIE), in its strategy for diminishing the energy consumption through the design enhancement, the manufacture, the operation and the standardization of the electric appliances. In order to initiate the evaluation-standardization process, the Mexican (NOM), the American (ANSI/AHAM) and the Canadian (CAN/CSA) standards were taken as a base to harmonize the procedures and the parameters of the tests. The energy assessment demonstrated that there are significant differences among the standards encompassed by the study, therefore, recommendations were made for the harmonization of the standards. [Espanol] Se describe un estudio de evaluacion energetica sobre refrigeradores electrodomesticos realizado en el Instituto de Investigaciones Electricas (IIE) dentro de la estrategia para disminuir los consumos de energia a traves de mejoras en el diseno, la manufactura, la operacion y la normalizacion de equipos electricos. Se tomo como base las normas mexicanas (NOM), americana (ANSI/AHAM) y canadiense (CAN/CSA) para iniciar el proceso de evaluacion-normalizacion a fin de armonizar los procedimientos y parametros de las pruebas. La evaluacion energetica demostro que existen diferencias significativas entre las normas que abarco el estudio por lo que se presentan recomendaciones para la armonizacion de las normas.

  12. 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...

  13. Small variable speed hermetic reciprocating compressors for domestic refrigerators

    DEFF Research Database (Denmark)

    Rasmussen, Bjarne D.

    1996-01-01

    This paper contains both a theoretical and experimental investigation of some of the fundamental characteristics of a smal variable speed hermetic reciprocating compressor intended for application in domestic refrigeration. The results of a previously published simulation model for variable speed...

  14. Assessment of propane/commercial butane mixtures as possible alternatives to R134a in domestic refrigerators

    International Nuclear Information System (INIS)

    Fatouh, M.; El Kafafy, M.

    2006-01-01

    The possibility of using hydrocarbon mixtures as working fluids to replace R134a in domestic refrigerators has been evaluated through a simulation analysis in the present work. The performance characteristics of domestic refrigerators were predicted over a wide range of evaporation temperatures (-35 to -10 o C) and condensation temperatures (40-60 deg. C) for various working fluids such as R134a, propane, commercial butane and propane/iso-butane/n-butane mixtures with various propane mass fractions. The performance characteristics of the considered domestic refrigerator were identified by the coefficient of performance (COP), volumetric cooling capacity, cooling capacity, condenser capacity, input power to compressor, discharge temperature, pressure ratio and refrigerant mass flow rate. The results showed that pure propane could not be used as a drop in replacement for R134a in domestic refrigerators because of its high operating pressures and low COP. Commercial butane yields many desirable characteristics but requires a compressor change. The coefficient of performance of the domestic refrigerator using a ternary hydrocarbon mixture with propane mass fractions from 0.5 to 0.7 is higher than that of R134a. Comparison among the considered working fluids confirmed that the average refrigerant mass flow rate of the propoane/commercial butane mixture is 50% lower than that of R134a. Also, the results indicated that R134a and the propoane/commercial butane mixture with 60% propane mass concentration have approximately the same values of saturation pressure, compressor discharge temperature, condenser heat load, input power, cooling capacity and volumetric cooling capacity. However, the pressure ratio of the hydrocarbon mixture with 60% propane is lower than that of R134a by about 11.1%. Finally, the reported results confirmed that the propane/iso-butane/n-butane mixture with 60% propane is the best drop in replacement for R134a in domestic refrigerators under normal

  15. Electric power saving potential due to domestic refrigerators replacement; Potencial de ahorro de energia electrica por el reemplazo de refrigeradores domesticos

    Energy Technology Data Exchange (ETDEWEB)

    Peralta Solorio, Jose Luis [Fideicomiso para el Ahorro de Energia Electrica (Mexico)]. E-mail: jose.peralta@cfe.gob.mx

    2006-04-15

    In Mexico the second most used electrical appliance is: refrigerator. Owing to its use, it would be a promising option for electric power saving. In Guadalajara, Reynosa and Tampico it was performed a study with the aim of launching a project to replace the old refrigerators with new ones which are more effective and less expensive. Since the refrigerators cost and the electrical invoicing saving, the electric appliance change is profitable. To expect with this replacement more than eight million of refrigerators manufactured before 1997 will be changed. [Spanish] El refrigerador es el segundo electrodomestico mas utilizado a nivel nacional, esto permite que debido a su uso sea una opcion prometedora para el ahorro de energia electrica. Se hizo un estudio en Guadalajara, Reynosa y Tampico con el fin de lanzar un proyecto para sustituir los refrigeradores viejos por unos nuevos que sean mas eficaces y menos costosos. Por el costo de los refrigeradores y el ahorro en la facturacion electrica, el cambio de electrodomestico es rentable, de esta manera se espera que los mas de ocho millones de refrigeradores fabricados antes de 1997 que existen en el pais sean cambiados.

  16. Energy efficiency study of the domestic refrigerators inside of a controlled environment laboratory; Estudio de la eficiencia energetica de refrigeradores domesticos dentro de un laboratorio de ambiente controlado

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo Cabanas, Fernando Gabriel

    2004-04-15

    The evaluation of the energy saving potential is looked for that exists in the park of domestic refrigerators of the country when replacing them by refrigerators of higher power efficiency, through a comparative analysis of the results obtained in experimental tests applied to domestic refrigerators, in agreement with Official Norm NOM 015-2002 and with the theoretical values reported by the manufacturers. Initially the park of domestic refrigerators used in Mexico (brand names, efficiency and electrical consumption) was studied with the objective of evaluating the electric energy consumption in the refrigerators at national level. Once with the consumption determined, a governmental program for the accelerated substitution of the park of domestic refrigerators of greater antiquity is proposed, for models of better power efficiency. Next, the characterization of the Laboratorio de Ambiente Controlado is made (preliminary tests of thermal stability and heat losses) to obtain the thermal conditions marked by Norm NOM-015-2002. Also relevant points for the experimental energy analysis are established in domestic refrigerators according to norm NOM-015-2002. Finally, a test protocol for domestic refrigerators applied in the LAC with base in this norm will be proposed and a validation of this by means of the necessary experimental tests and the required calculations will be carried out. Finally the obtained results of the tests of power efficiency applied to different models from domestic refrigerators, as well as conclusions are presented. [Spanish] Se busca evaluar el potencial de ahorro de energia que existe en el parque de refrigeradores domesticos del pais al sustituirlos por refrigeradores de mayor eficiencia energetica, a traves de un analisis comparativo de los resultados obtenidos de pruebas experimentales aplicadas a refrigeradores domesticos, de acuerdo con la Norma Oficial NOM.015-2002 y con los valores teoricos reportados por los fabricantes. Primeramente

  17. 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

  18. 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

  19. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  20. Domestic Refrigerators Temperature Prediction Strategy for the Evaluation of the Expected Power Consumption

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam; Marinelli, Mattia; Kosek, Anna Magdalena

    2013-01-01

    This paper discusses and presents a simple temperature prediction strategy for the domestic refrigerator. The main idea is to predict the duration it takes to the Cold chamber temperature to reach the thresholds according to the state of the compressor and to the last temperature measurements....... The experiments are conducted at SYSLAB facility at DTU Risø Campus having a set of refrigerators working at different set point temperatures, with different ambient temperatures and under different thermal load conditions. The prediction strategy is tested using a set of different refrigerators in order...

  1. An encyclopedia on domestic electricity

    International Nuclear Information System (INIS)

    1982-12-01

    This book describes the footprint of domestic electrification with domestic energy and the role of electrification, basic knowledge on domestic electrification, the basic things electric equipment in domestic, materials, part and making, demand of electricity, electrification and life, various electric equipment in the kitchen, rationalization of house chore, environment and hygiene like electric iron, electric stove, electric mat and dining wagon, beauty treatment and health, refinement and entertainment and lighting in houses.

  2. Experimental study of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator

    International Nuclear Information System (INIS)

    Wongwises, Somchai; Chimres, Nares

    2005-01-01

    This work presents an experimental study on the application of hydrocarbon mixtures to replace HFC-134a in a domestic refrigerator. The hydrocarbons investigated are propane (R290), butane (R600) and isobutane (R600a). A refrigerator designed to work with HFC-134a with a gross capacity of 239 l is used in the experiment. The consumed energy, compressor power and refrigerant temperature and pressure at the inlet and outlet of the compressor are recorded and analysed as well as the distributions of temperature at various positions in the refrigerator. The refrigerant mixtures used are divided into three groups: the mixture of three hydrocarbons, the mixture of two hydrocarbons and the mixture of two hydrocarbons and HFC-134a. The experiments are conducted with the refrigerants under the same no load condition at a surrounding temperature of 25 deg. C. The results show that propane/butane 60%/40% is the most appropriate alternative refrigerant to HFC-134a

  3. An experimental investigation on the substitution of HFC134a with HFO1234YF in a domestic refrigerator

    International Nuclear Information System (INIS)

    Aprea, Ciro; Greco, Adriana; Maiorino, Angelo

    2016-01-01

    Highlights: • An experimental comparison between R134A and HFO1234YF is presented. • A domestic refrigerator made to work with R134A is analysed. • The annual energy consumptions of the device are reported. • The energy saving achievable after the drop-in is evaluated. - Abstract: The latest international regulations on the reduction of greenhouse gases are strongly redesigning the scenario of use of refrigerants, gradually eliminating the possibility of employing the HFCs. Among all sectors of refrigeration, one of the most affected by these restrictions is the domestic refrigeration. Although for it have been suggested some solutions, such as the construction of household refrigerator operating with the hydrocarbons, there remains the need to find a substitute for HFC134a. In particular, the substitution may involve both existing machines and already in operation, which cannot be loaded with hydrocarbons, and new devices. With the aim of finding a simple implementation solution, in the present work, it is reported an experimental investigation carried out on a domestic refrigerator designed and built to operate with HFC134a and for which a drop-in with HFO1234yf has been realised. The experimentation has been addressed so as to highlight the behaviour of the system as a result of the drop-in, with a particular interest in the energy performance variation. A slight energy saving has been recorded with HFO1234yf, and an improving of the cooling capacity has been noticed.

  4. Improvement of a thermoelectric and vapour compression hybrid refrigerator

    International Nuclear Information System (INIS)

    Astrain, D.; Martínez, A.; Rodríguez, A.

    2012-01-01

    This paper presents the improvement in the performance of a domestic hybrid refrigerator that combines vapour compression technology for the cooler and freezer compartments, and thermoelectric technology for a new compartment. The heat emitted by the Peltier modules is discharged into the freezer compartment, forming a cascade refrigeration system. This configuration leads to a significant improvement in the coefficient of operation. Thus, the electric power consumption of the modules and the refrigerator decreases by 95% and 20% respectively, with respect to those attained with a cascade refrigeration system connected with the cooler compartment. The optimization process is based on a computational model that simulates the behaviour of the whole refrigerator. Two prototypes have been built and tested. Experimental results indicate that the temperature of the new compartment is easily set up at any value between 0 and −4 °C, the oscillation of this temperature is always lower than 0.4 °C, and the electric power consumption is low enough to include this hybrid refrigerator into energy efficiency class A, according European rules and regulations. - Highlights: ► Optimization of a vapour compression and thermoelectric hybrid refrigerator. ► Two prototypes built and tested. Computational model for the whole refrigerator. ► Electric power consumption of the modules and the refrigerator 95% and 20% lower. ► New compartment refrigerated with thermoelectric technology. ► Inner temperature adjustable from 0 to −4 °C. Oscillations lower than ±0.2 °C.

  5. Modelling of domestic refrigerators' energy consumption under real life conditions in Europe

    Energy Technology Data Exchange (ETDEWEB)

    Geppert, Jasmin

    2011-05-23

    In recent decades, energy and resource savings have become increasingly important, not only in the industrial, but also the residential sector. As one of the largest energy users in private homes, domestic refrigerators and freezers were among the first appliances to be targeted for energy efficiency improvements. With the aim of encouraging manufacturers to develop and produce more efficient appliances, the European Energy Label was introduced in the mid-nineties. However, the energy use of refrigerators does not only depend on technical components and features. Especially the using conditions in private homes are of a decisive influence. Thus, the present study has been conducted to test the sensitivity of refrigerators' energy consumption to various usage conditions within realistic ranges, which have been determined by means of two empirical studies. Key information gathered from the experiments were used as a base for the development and validation of a simplified model that allows predicting the energy consumption of refrigerators in use. The practical experiments were performed under controlled laboratory conditions with four different refrigerators with an A{sup +} or A{sup ++} energy efficiency rating (two statically cooled built-in fridge-freezers, one dynamically cooled refrigerator and one statically cooled refrigerator). The investigations revealed that the ambient temperature has the greatest impact on a refrigerator's energy consumption, followed by thermostat setting and heat load by insertion of warm items. The refrigerators' load under static conditions as well as the number of door openings have almost no impact on energy consumption. The modelling methodology follows a first-principle approach adjusted by experimental data. When compared to experimental results, model predictions show a reasonable agreement for the whole range of investigated conditions. (orig.)

  6. The application of ionizers in domestic refrigerators for reduction in airborne and surface bacteria.

    Science.gov (United States)

    Kampmann, Y; Klingshirn, A; Kloft, K; Kreyenschmidt, J

    2009-12-01

    To investigate the antimicrobial effect of ionization on bacteria in household refrigerators. Ionizer prototypes were tested with respect to their technical requirements and their ability to reduce surface and airborne contamination in household refrigerators. Ion and ozone production of the tested prototypes were measured online by an ion meter and an ozone analyser. The produced negative air ion (NAI) and ozone amounts were between 1.2 and 3.7 x 10(6) NAI cm(-3) and 11 and 19 ppb O(3), respectively. To test the influence of ionization on surface contamination, different materials like plastic, glass and nutrient agar for simulation of food were inoculated with bacterial suspensions. The reduction rate was dependent on surface properties. The effect on airborne bacteria was tested by nebulization of Bacillus subtilis- suspension (containing spores) aerosols in refrigerators with and without an ionizer. A clear reduction in air contamination because of ionization was measured. The antimicrobial effect is dependent on several factors, such as surface construction and airflow patterns within the refrigerator. Ionization seems to be an effective method for reduction in surface and airborne bacteria. This study is an initiation for a new consumer tool to decontaminate domestic refrigerators.

  7. 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

  8. 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

  9. Projected electricity savings from implementing minimum energy efficiency standard for household refrigerators in Malaysia

    International Nuclear Information System (INIS)

    Mahlia, T.M.I.; Masjuki, H.H.; Saidur, R.; Choudhury, I.A.; NoorLeha, A.R.

    2003-01-01

    The Malaysian economy has grown rapidly in the last two decades. This growth has increased the ownership of household electrical appliances, especially refrigerator-freezers. Almost every house in Malaysia owns a refrigerator-freezer. The Malaysia Energy Center considered implementing a minimum energy efficiency standard for household refrigerator-freezers sometime in the coming year. This paper attempts to predict the amount of energy savings in the residential sector by implementing a minimum energy efficiency standard for household refrigerator-freezers. The calculations are based on the growth of refrigerator-freezer ownership data in Malaysian households. By implementing the programs in 2004, about 8722 GWh will be saved in the year 2013. Therefore, efficiency improvement of this appliance will provide a significant impact in future electricity consumption in Malaysia

  10. Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials

    Directory of Open Access Journals (Sweden)

    Angelika-Ioanna Gialleli

    2017-01-01

    Full Text Available Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C. The positive eff ect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose signifi cantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the eff ect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confi rmed by the analysis of the fi nal products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profi le and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

  11. Technological Development of Brewing in Domestic Refrigerator Using Freeze-Dried Raw Materials.

    Science.gov (United States)

    Gialleli, Angelika-Ioanna; Ganatsios, Vassilios; Terpou, Antonia; Kanellaki, Maria; Bekatorou, Argyro; Koutinas, Athanasios A; Dimitrellou, Dimitra

    2017-09-01

    Development of a novel directly marketable beer brewed at low temperature in a domestic refrigerator combined with yeast immobilization technology is presented in this study. Separately, freeze-dried wort and immobilized cells of the cryotolerant yeast strain Saccharomyces cerevisiae AXAZ-1 on tubular cellulose were used in low-temperature fermentation (2, 5 and 7 °C). The positive effect of tubular cellulose during low-temperature brewing was examined, revealing that freeze-dried immobilized yeast cells on tubular cellulose significantly reduced the fermentation rates in contrast to freeze-dried free cells, although they are recommended for home-made beer production. Immobilization also enhanced the yeast resistance at low-temperature fermentation, reducing the minimum brewing temperature value from 5 to 2 °C. In the case of high-quality beer production, the effect of temperature and initial sugar concentration on the fermentation kinetics were assessed. Sensory enrichment of the produced beer was confirmed by the analysis of the final products, revealing a low diacetyl concentration, together with improved polyphenol content, aroma profile and clarity. The proposed process for beer production in a domestic refrigerator can easily be commercialized and applied by dissolving the content of two separate packages in tap water; one package containing dried wort and the other dried immobilized cells on tubular cellulose suspended in tap water.

  12. Performance analysis of the electric vehicle air conditioner by replacing hydrocarbon refrigerant

    Science.gov (United States)

    Santoso, Budi; Tjahjana, D. D. D. P.

    2017-01-01

    The thermal comfort in passenger cabins needs an automotive air-conditioning system. The electric vehicle air conditioner system is driven by an electric compressor which includes a compressor and an electric motor. Almost air-conditioning system uses CFC-12, CFC-22 and HFC-134a as refrigerant. However, CFC-12 and CFC-22 will damage the ozone layer. The extreme huge global warming potentials (GWP) values of CFC-12, CFC-22, and HFC-134a represent the serious greenhouse effect of Earth. This article shows new experimental measurements and analysis by using a mixture of HC-134 to replace HFC-134a. The result is a refrigerating effect, the coefficient of performance and energy factor increase along with cooling capacity, both for HFC-134a and HC-134. The refrigerating effect of HC-134 is almost twice higher than HFC-134a. The coefficient of performance value of HC-134 is also 36.42% greater than HFC-134a. Then, the energy factor value of HC-134 is 3.78% greater than HFC-134a.

  13. Numerical investigation of refrigeration machine compressor operation considering single-phase electric motor dynamic characteristics

    Science.gov (United States)

    Baidak, Y.; Smyk, V.

    2017-08-01

    Using as the base the differential equations system which was presented in relative units for generalized electric motor of hermetic refrigeration compressor, mathematical model of the software for dynamic performance calculation of refrigeration machine compressors drive low-power asynchronous motors was developed. Performed on its ground calculations of the basic model of two-phase electric motor drive of hermetic compressor and the proposed newly developed model of the motor with single-phase stator winding, which is an alternative to the industrial motor winding, have confirmed the benefits of the motor with innovative stator winding over the base engine. Given calculations of the dynamic characteristics of compressor drive motor have permitted to determine the value of electromagnetic torque swinging for coordinating compressor and motor mechanical characteristics, and for taking them into consideration in choosing compressor elements construction materials. Developed and used in the process of investigation of refrigeration compressor drive asynchronous single-phase motor mathematical and software can be considered as an element of computer-aided design system for design of the aggregate of refrigeration compression unit refrigerating machine.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1995-03-01

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

  15. Electricity Profile Study for Domestic and Commercial Sectors

    OpenAIRE

    Asmarashid Ponniran; Nur Azura Mamat; Ariffudin Joret

    2012-01-01

    As Malaysia move towards as a developed country, it is expected that the electricity consumption in domestic and commercial sectors will increase as well as more industrials and households need. This study is to investigate the electricity profile in domestic and commercial sectors by monitoring some appropriate appliances that contribute high electricity consumption. The characteristics for every major loads are examined and the potential energy saving is compared to an efficient electrical ...

  16. Max Tech Efficiency Electric HPWH with low-GWP Halogenated Refrigerant

    Energy Technology Data Exchange (ETDEWEB)

    Nawaz, Kashif [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Elatar, Ahmed F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baxter, Van D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    A scoping-level analysis was conducted to determine the maximum performance of an electric heat pump water heater (HPWH) with low GWP refrigerants (hydroflouroolefins (HFO), hydrofluorocarbons (HFC), and blends). A baseline heat pump water heater (GE GeoSpring) deploying R-134a was analyzed first using the DOE/ORNL Heat Pump Design Model (HPDM) modeling tool. The model was calibrated using experimental data to match the water temperature stratification in tank, first hour rating, energy factor and coefficient of performance. A CFD modeling tool was used to further refine the HPDM tank model. After calibration, the model was used to simulate the performance of alternative refrigerants. The parametric analysis concluded that by appropriate selection of equipment size and condenser tube wrap configuration the overall performance of emerging low GWP refrigerants for HPWH application not only exceed the Energy Star Energy Factor criteria i.e. 2.20, but is also comparable to some of the most efficient products in the market.

  17. 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.

  18. 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

  19. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    Directory of Open Access Journals (Sweden)

    J. A. Olorunmaiye

    2012-12-01

    Full Text Available One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150 THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in a room with the air-conditioner switched off and near an oven in a bakery. The electric power consumption of the refrigerator was measured using "Watts up?.net" Watt meter and the ambient temperature was measured using FLUKE temperature/humidity meter. The average hourly energy consumption of the refrigerator operating at mean ambient temperatures of 25.4°C, 30.7oC, 38.8°C were 93.844 Wh, 100.32 Wh and 105.08 Wh respectively. Some possible ways to reduce the increase in power consumption of refrigerators due to global warming include using compressors of higher efficiency and condensers of greater effectiveness.

  20. High-resolution stochastic integrated thermal–electrical domestic demand model

    International Nuclear Information System (INIS)

    McKenna, Eoghan; Thomson, Murray

    2016-01-01

    Highlights: • A major new version of CREST’s demand model is presented. • Simulates electrical and thermal domestic demands at high-resolution. • Integrated structure captures appropriate time-coincidence of variables. • Suitable for low-voltage network and urban energy analyses. • Open-source development in Excel VBA freely available for download. - Abstract: This paper describes the extension of CREST’s existing electrical domestic demand model into an integrated thermal–electrical demand model. The principle novelty of the model is its integrated structure such that the timing of thermal and electrical output variables are appropriately correlated. The model has been developed primarily for low-voltage network analysis and the model’s ability to account for demand diversity is of critical importance for this application. The model, however, can also serve as a basis for modelling domestic energy demands within the broader field of urban energy systems analysis. The new model includes the previously published components associated with electrical demand and generation (appliances, lighting, and photovoltaics) and integrates these with an updated occupancy model, a solar thermal collector model, and new thermal models including a low-order building thermal model, domestic hot water consumption, thermostat and timer controls and gas boilers. The paper reviews the state-of-the-art in high-resolution domestic demand modelling, describes the model, and compares its output with three independent validation datasets. The integrated model remains an open-source development in Excel VBA and is freely available to download for users to configure and extend, or to incorporate into other models.

  1. Development of a hybrid refrigerator combining thermoelectric and vapor compression technologies

    International Nuclear Information System (INIS)

    Vian, J.G.; Astrain, D.

    2009-01-01

    A domestic refrigerator with three compartments has been developed: refrigerator compartment, at 4 deg. C (vapor compression cooling system); freezer compartment, at -22 deg. C (vapor compression cooling system); and a new super-conservation compartment, at 0 deg. C (thermoelectric cooling system). The thermoelectric system designed for the super-conservation compartment eliminates the oscillation of its temperature due to the start and stop compressor cycles, obtaining a constant temperature and thus, a better preservation of the food. For the design and optimization of this application, a computational model, based in the numerical method of finite differences, has been developed. This model allows to simulate the complete hybrid refrigerator (vapor compression-thermoelectricity). The accuracy of the model has been experimentally checked, with a maximum error of 1.2 deg. C for temperature values, and 8% for electric power consumption. By simulations with the computational model, the design of the refrigerator has been optimized, obtaining a final prototype highly competitive, by the features on food preservation and power consumption: 1.15 kW h per day (48.1 W) for an ambient temperature of 25 deg. C. According to European rules, this power consumption value means that this new refrigerator could be included on energy efficiency class B.

  2. Thermal Simulation of the Fresh Food Compartment in a Domestic Refrigerator

    Directory of Open Access Journals (Sweden)

    Juan M. Belman-Flores

    2017-01-01

    Full Text Available In the field of domestic refrigeration, it is important to look for methods that can be used to simulate, and, thus, improve the thermal behavior of the fresh food compartment. In this sense, this study proposes some methods to model the thermal behavior of this compartment when the shelves’ positions are changed. Temperature measurements at specific locations in this compartment were obtained. Several shelf position combinations were performed to use three 2D interpolation methods in order to simulate the temperature mean and the temperature variance. The methods used were: Lagrange’s interpolation, cubic spline interpolation and bilinear interpolation. Two validation points were chosen to verify the proposed methods. By comparing the experimental results with the computer simulations, it was possible to conclude that the method of Lagrange’s interpolation provided values that were not close to the real measured values. On the other hand, it was observed that the method of bilinear interpolation offered the best results, estimating values which were very close to the actual experimental measurements. These interpolation methods were used to build color thermal graphs that can be used to find some of the most appropriate shelf position combinations in this type of refrigerator. By inspection of these thermal graphs, it can be seen that the lowest average temperature was obtained when one shelf was located at 24.5 cm while the second shelf was located at 29.5 cm measured from the top of the compartment. In the same way, it can be seen that the minimum temperature variance was obtained when only one shelf was inside the compartment and this shelf was located at 29.5 cm.

  3. Experimental analysis of a diffusion absorption refrigeration system used alternative energy sources

    International Nuclear Information System (INIS)

    Soezen, A.; Oezbas, E.

    2009-01-01

    The continuous-cycle absorption refrigeration device is widely used in domestic refrigerators, and recreational vehicles. It is also used in year-around air conditioning of both homes and larger buildings. The unit consists of four main parts the boiler, condenser, evaporator and the absorber. When the unit operates on kerosene or gas, the heat is supplied by a burner. This element is fitted underneath the central tube. When operating on electricity, the heat is supplied by an element inserted in the pocket. No moving parts are employed. The operation of the refrigerating mechanism is based on Dalton's law. In this study, experimental analysis was performed of a diffusion absorption refrigeration system (DARS) used alternative energy sources such as solar, liquid petroleum gas (LPG) sources. Two basic DAR cycles were set up and investigated: i) In the first cycle (DARS-1), the condensate is sub-cooled prior to the evaporator entrance by the coupled evaporator/gas heat exchanger similar with manufactured by Electrolux Sweden. ii) In the second cycle (DARS-2), the condensate is not sub-cooled prior to the evaporator entrance and gas heat exchanger is separated from the evaporator. (author)

  4. Life cycle assessment of domestic heat pump hot water systems in Australia

    Directory of Open Access Journals (Sweden)

    Moore Andrew D.

    2017-01-01

    Full Text Available Water heating accounts for 23% of residential energy consumption in Australia, and, as over half is provided by electric water heaters, is a significant source of greenhouse gas emissions. Due to inclusion in rebate schemes heat pump water heating systems are becoming increasingly popular, but do they result in lower greenhouse gas emissions? This study follows on from a previous life cycle assessment study of domestic hot water systems to include heat pump systems. The streamlined life cycle assessment approach used focused on the use phase of the life cycle, which was found in the previous study to be where the majority of global warming potential (GWP impacts occurred. Data was collected from an Australian heat pump manufacturer and was modelled assuming installation within Australian climate zone 3 (AS/NZS 4234:2011. Several scenarios were investigated for the heat pumps including different sources of electricity (grid, photovoltaic solar modules, and batteries and the use of solar thermal panels. It was found that due to their higher efficiency heat pump hot water systems can result in significantly lower GWP than electric storage hot water systems. Further, solar thermal heat pump systems can have lower GWP than solar electric hot water systems that use conventional electric boosting. Additionally, the contributions of HFC refrigerants to GWP can be significant so the use of alternative refrigerants is recommended. Heat pumps combined with PV and battery technology can achieve the lowest GWP of all domestic hot water systems.

  5. Energy consumption of small refrigerators - Information leaflet; Merkblatt Kleinkuehlschrank

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    In this leaflet published by the Swiss Federal Office of Energy (SFOE), the energy consumption of small refrigerators with a capacity of less than 100 litres is reported on. Such small refrigerators are often used in hotel rooms or in campers. It is noted that, in comparison, a typical, 150 litre class A++ domestic refrigerator uses only a fraction of the amount of energy used by such small refrigerators. The results of measurements made according to EN 153 and ISO 15502 norms are discussed. Recommendations are made on the purchase and operation of these small refrigerators.

  6. 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…

  7. 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.

  8. Modelling aggregate domestic electricity demand in Ghana: An autoregressive distributed lag bounds cointegration approach

    International Nuclear Information System (INIS)

    Adom, Philip Kofi; Bekoe, William; Akoena, Sesi Kutri Komla

    2012-01-01

    In spite of the varying supply boosting efforts made by various governments to deal with the existing demand–supply gap in the electricity sector, the incessant growth in aggregate domestic electricity demand has made these efforts futile. As an objective, this paper attempts to identify the factors responsible for the historical growth trends in aggregate domestic electricity demand quantifying their effects both in the short-run and long-run periods using the ARDL Bounds cointegration approach and the sample period 1975 to 2005. In the long-run, real per capita GDP, industry efficiency, structural changes in the economy, and degree of urbanisation are identified as the main driving force behind the historical growth trend in aggregate domestic electricity demand. However, in the short-run, real per capita GDP, industry efficiency, and degree of urbanisation are the main drivers of aggregate domestic electricity demand. Industry efficiency is the only factor that drives aggregate domestic electricity demand downwards. However, the negative efficiency effect is insufficient to have outweighed the positive income, output, and demographic effects, hence the continual growth in aggregate domestic electricity demand. As a policy option, we recommend that appropriate electricity efficiency standards be implemented at the industry level. - Highlights: ► Real per capita GDP is the primary determinant of electricity demand both in the short and long-run. ► Industrial efficiency, structural changes and urbanisation rate play secondary role. ► The positive income, output, and demographic effects outweigh the negative efficiency effects.

  9. 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.

  10. 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...

  11. Performance Characteristics of a Refrigerator-Freezer with Parallel Evaporators using a Linear Compressor

    OpenAIRE

    Min, Byungchae; Song, Sangjin; Noh, Kiyoul; Kim, Geonwoo; Yoon, Teaseung; Na, Sangkyung; Song, Sanghoon; Yang, Jangsik; Choi, Gyungmin; Kim, Duckjool

    2016-01-01

    A linear compressor for a domestic refrigerator-freezer has energy saving potential compared with a reciprocating compressor because of a low friction loss and free piston system. A linear compressor can control the piston stroke since it does not have mechanical restriction of piston movement. Therefore, the energy consumption of a domestic refrigerator-freezer using a linear compressor can be reduced by changing the cooling capacity of the compressor. In order to investigate the performance...

  12. Effect of temperature in domestic refrigerators on fresh-cut Iceberg salad quality and waste.

    Science.gov (United States)

    Manzocco, L; Alongi, M; Lagazio, C; Sillani, S; Nicoli, M C

    2017-12-01

    The evolution of different quality parameters (firmness, weight loss, colour changes, microbial counts, consumer rejection) of packed fresh-cut Iceberg salad was assessed at 4, 8 and 12°C to simulate domestic refrigerators running at different conditions. The increase in storage temperature did not affect salad firmness and weight loss but increased colour changes, microbial growth and consumer rejection. A survey among Italian consumers was also carried out and demonstrated that fresh-cut salad was mainly consumed within the first 5days after purchasing. Consumer rejection data were combined with data relevant to the distribution of salad consumption over the days following product purchase, to estimate salad wasting risk. When salad was stored at 4 and 8°C, estimated wasted packages within the expiration date (7days) were sustainable interventions to tackle food waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. World's first ejector cycle for mobile refrigerators to stop global warming

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Hirotsugu [Denso Corporation, Kariya (Japan); Gyoeroeg, Tibor [DENSO AUTOMOTIVE Deutschland GmbH, Eching (Germany)

    2010-07-01

    The development of energy-saving technologies is in great demand recently to stop global warming. We are committed to developing the Ejector Cycle as an energy-saving technology for refrigerators and air conditioners. The ejector, which is an energy-saving technological innovation, improves the efficiency of the refrigeration cycle by effectively using the expansion energy that is lost in the conventional vapor-compression cycle, and is applicable to almost all vapor-compression refrigerating air conditioners, thus improving the efficiency of the refrigeration cycle. Concerning the application of the Ejector Cycle in truck-transport refrigerators, we released Ejector Cycle products for large and medium-size freezer trucks, which have been favorably accepted by customers in 2003. Simultaneously we also developed the domestic water supply system using heat pump with natural refrigerant (CO{sub 2}). We developed a new Ejector Cycle, completed in 2007 a cool box which uses the refrigeration cycle of the mobile air-conditioning system to cool drinks and the commercial compact refrigerator. In 2008 a domestic water supply heat pump system using a heat pump with the natural refrigerant CO{sub 2} and the next-generation Ejector Cycle II that substantially improves performance was brought to the market. A new generation of Ejector Cycle is under development which will significantly improve the efficiency of mobile air conditioning systems (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-01-01

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

  15. Cooling performance of R510A in domestic water purifiers

    International Nuclear Information System (INIS)

    Park, Ki Jung; Lee, Yo Han; Jung, Dong Soo

    2010-01-01

    Cooling performance of R510A is examined both numerically and experimentally in an effort to replace HFC134a in the refrigeration system of domestic water purifiers. Although the use of HFC134a is currently dominant, it is being phased out in Europe and most developed countries due to its high potential contribution to global warming. To solve this problem, cycle simulation and experimental measurements are conducted with a new refrigerant mixture of 88%RE170/12%R600a using actual domestic water purifiers. This mixture has been recently numbered and listed as R510A by ASHRAE. Test results show that, due to the small internal volume of the refrigeration system of the domestic water purifiers, system performance with R510A is greatly influenced by the amount of charge. With the optimum charge amount of 20 to 21 g, approximately 50% that of HFC134a, the energy consumption of R510A is 22.3% lower than that of HFC134a. The compressor discharge temperature of R510A is 3.7 .deg. C lower than that of HFC134a at the optimum charge. Overall, R510A, a new, long term, and environmentally safe refrigerant, is a good alternative for HFC134a. Furthermore, it requires only minor changes in the refrigeration system of the domestic water purifiers

  16. A new compressed air energy storage refrigeration system

    International Nuclear Information System (INIS)

    Wang Shenglong; Chen Guangming; Fang Ming; Wang Qin

    2006-01-01

    In this study, a new compressed air energy storage (CAES) refrigeration system is proposed for electrical power load shifting application. It is a combination of a gas refrigeration cycle and a vapor compression refrigeration cycle. Thermodynamic calculations are conducted to investigate the performance of this system. Economic analysis is performed to study the operating cost of the system, and comparison is made with a vapor compression refrigeration system and an ice storage refrigeration system. The results indicate that the CAES refrigeration system has the advantages of simple structure, high efficiency and low operating cost

  17. Reliability Prediction Approaches For Domestic Intelligent Electric Energy Meter Based on IEC62380

    Science.gov (United States)

    Li, Ning; Tong, Guanghua; Yang, Jincheng; Sun, Guodong; Han, Dongjun; Wang, Guixian

    2018-01-01

    The reliability of intelligent electric energy meter is a crucial issue considering its large calve application and safety of national intelligent grid. This paper developed a procedure of reliability prediction for domestic intelligent electric energy meter according to IEC62380, especially to identify the determination of model parameters combining domestic working conditions. A case study was provided to show the effectiveness and validation.

  18. 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.

  19. Flexible demand in the GB domestic electricity sector in 2030

    International Nuclear Information System (INIS)

    Drysdale, Brian; Wu, Jianzhong; Jenkins, Nick

    2015-01-01

    Highlights: • Annual domestic demand by category and daily flexible load profiles are shown to 2030. • Valuable flexible demand requires loads to be identifiable, accessible, and useful. • The extent of flexible demand varies significantly on a diurnal and seasonal basis. • Barriers to accessing domestic demand include multiple low value loads and apathy. • Existing market structure a barrier to fully rewarding individual load flexibility. - Abstract: In order to meet greenhouse gas emissions targets the Great Britain (GB) future electricity supply will include a higher fraction of non-dispatchable generation, increasing opportunities for demand side management to maintain a supply/demand balance. This paper examines the extent of flexible domestic demand (FDD) in GB, its usefulness in system balancing and appropriate incentives to encourage consumers to participate. FDD, classified as electric space and water heating (ESWH), and cold and wet appliances, amounts to 59 TW h in 2012 (113 TW h total domestic demand) and is calculated to increase to 67 TW h in 2030. Summer and winter daily load profiles for flexible loads show significant seasonal and diurnal variations in the total flexible load and between load categories. Low levels of reflective consumer engagement with electricity consumption and a resistance to automation present barriers to effective access to FDD. A value of £1.97/household/year has been calculated for cold appliance loads used for frequency response in 2030, using 2013 market rates. The introduction of smart meters in GB by 2020 will allow access to FDD for system balancing. The low commercial value of individual domestic loads increases the attractiveness of non-financial incentives to fully exploit FDD. It was shown that appliance loads have different characteristics which can contribute to an efficient power system in different ways

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-01

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

  1. Industrial trigeneration using ammonia-water absorption refrigeration systems (AAR)

    International Nuclear Information System (INIS)

    Colonna, Piero; Gabrielli, Sandro

    2003-01-01

    In many industrial processes there is a simultaneous need for electric power and refrigeration at low temperatures. Examples are in the food and chemical industries. Nowadays the increase in fuel prices and the ecological implications are giving an impulse to energy technologies that better exploit the primary energy source and integrated production of utilities should be considered when designing a new production plant. The number of so-called trigeneration systems installations (electric generator and absorption refrigeration plant) is increasing. If low temperature refrigeration is needed (from 0 to -40 deg. C), ammonia-water absorption refrigeration plants can be coupled to internal combustion engines or turbogenerators. A thermodynamic system study of trigeneration configurations using a commercial software integrated with specifically designed modules is presented. The study analyzes and compares heat recovery from the primary mover at different temperature levels. In the last section a simplified economic assessment that takes into account disparate prices in European countries compares conventional electric energy supply from the grid and optimized trigeneration plants in one test case (10 MW electric power, 7000 h/year)

  2. 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

  3. 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.

  4. 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.

  5. The absorption refrigerator as a thermal transformer

    International Nuclear Information System (INIS)

    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

  6. Bacteriological quality of raw human milk: effect of storage in a refrigerator.

    Science.gov (United States)

    Olowe, S A; Ahmed, I; Lawal, S F; Ransome-Kuti, S

    1987-12-01

    Eighty-seven breast milk samples were obtained from 63 mothers of infants on the neonatal intensive care unit of the Lagos University Teaching Hospital. The samples were cultured for bacteria immediately after collection (0 h) and then stored in a domestic refrigerator from where cultures were repeated at 6-hourly intervals for 24 h. At 0 h, three (3.4%) of the samples were sterile; 56 (64%) grew coagulase negative staphylococci, and one (1.1%) Streptococcus viridans. Thus, 60 (69%) of the samples were either sterile or contained only skin commensals. Twenty-nine (31%) grew potential pathogens--coagulase positive staphylococci in two (2.3%) and mixed growth of staphylococci, coliforms and klebsiella in 25 (28.3%). During the 24 h storage in the refrigerator, bacteria multiplied in 50 and their growth was inhibited in 32 of the samples. But the mean bacterial count at any time during the 24 h was not significantly different from that at the beginning of the storage in the refrigerator. It is proposed that expressed breast milk stored in a domestic refrigerator can be given safely to infants within 24 h of collection if heavy contamination is prevented at the time of collection.

  7. 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.

  8. Modeling of in-vehicle magnetic refrigeration

    DEFF Research Database (Denmark)

    Olsen, Ulrik Lund; Bahl, Christian R.H.; Engelbrecht, Kurt

    2014-01-01

    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...

  9. 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...

  10. Cost-benefit analysis of implementing minimum energy efficiency standards for household refrigerator-freezers in Malaysia

    International Nuclear Information System (INIS)

    Mahlia, T.M.I.; Masjuki, H.H.; Saidur, R.; Amalina, M.A.

    2004-01-01

    The ownership of household electrical appliances especially refrigerator-freezer has increased rapidly in Malaysia. Almost every household in this country has a refrigerator-freezer. To reduce energy consumption in this sector the refrigerator is one of the top priorities of the energy efficiency program for household appliances. Malaysian authority is considering implementing minimum energy efficiency standards for refrigerator-freezer sometime in the coming year. This paper attempts to analyze cost-benefit of implementing minimum energy efficiency standards for household refrigerator-freezers in Malaysia. The calculations were made based on growth of ownership data for refrigerators in Malaysian households. The number of refrigerator-freezer has increased from 175,842 units in 1970 to 4,196,486 in 2000 and it will be about 11,293,043 in the year of 2020. Meanwhile it has accounted for about 26.3% of electricity consumption in a single household. Therefore, efficiency improvement of this appliance will give a significant impact in the future of electricity consumption in this country. Furthermore, it has been found that implementing an energy efficiency standard for household refrigerator-freezers is economically justified

  11. Domestic merger policy in an international oligopoly: the Nordic market for electricity

    International Nuclear Information System (INIS)

    Soergard, Lars

    1997-01-01

    Many domestic markets are becoming integrated in international markets. Is this an argument for permitting mergers between domestic producers? It is shown that a merger with no cost-saving effects will always be detrimental to domestic welfare if the country is an importer of the good in question, and may increase welfare if the country is an exporter and the price-cost margin is sufficiently low initially. We specify a general condition for a merger to improve welfare, and apply the condition on the Nordic market for electricity. Numerical calculations suggest that in this particular market the Norwegian competition authority should ban domestic mergers with no cost savings. (Author)

  12. 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.)

  13. Recent investigations on refrigerants for magnetic refrigerators

    International Nuclear Information System (INIS)

    Hashimoto, T.

    1986-01-01

    In development of the magnetic refrigerator, an important problem is selection of magnetic materials as refrigerants. The main purpose of the present paper is to discuss the magnetic and thermal properties necessary for these refrigerants and to report recent investigations. Magnetic refrigerants can be expediently divided into two groups, one for the Carnottype magnetic refrigerator below 20 K and the other for the Ericsson-type refrigerator. The required physical properties of refrigerants in each type of the magnetic refrigerator are first discussed. And then, the results of recent investigations on the magnetic, thermal and magnetocaloric characters of several promising magnetic refrigerants are shown. Finally, a brief prospect of the magnetic refrigerants and refrigerators is given

  14. Experimental analysis of diffusion absorption refrigerator driven by electrical heater and engine exhaust gas

    Directory of Open Access Journals (Sweden)

    Mohamed Izzedine Serge ADJIBADE

    2017-09-01

    Full Text Available This work presents an experimental study of H20-NH3-H2 diffusion absorption refrigeration under two types of energy sources, i.e. the conventional electric energy from grid (electric and exhaust gas from internal combustion engine. Dynamic method is used to evaluate the behavior of the components of the system for both energy sources. Results obtained show that the performance of each component under different types of energy sources is almost coherent. For the generator, the electrical heater system requires more time to warm up, around three minutes, compared to the 40 s for system running with exhaust gas. For the evaporator, the decreasing rate is higher for the exhaust gas source and it took only about two hours to reach steady-state while for the electrical heat, the steady-state is reached after about seven hours of operation. For both energy sources, the evaporation temperature stabilizes to 3 °C and the minimum temperature to boil off ammonia is around 140 °C.

  15. Efficient Use of Behavioral Tools to Reduce Electricity Demand of Domestic Consumers

    Directory of Open Access Journals (Sweden)

    Elbaz Shimon

    2016-12-01

    Full Text Available Purpose: The present study investigated the main literature on the subject of methods and policies for reducing the electricity demand of domestic consumers, in order to identify the place of behavioral tools. Methodology: We used secondary sources, performing a literature review, together with analysis and synthesis. Findings: Policy makers prefer to use tools offered by neoclassical economics, such as various forms of taxation, fines and financial incentives in order to make domestic electricity consumers save electricity, on the assumption that consumers will make rational decisions while maximizing their personal benefit. However, studies conducted in recent years in the field of behavioral economics, which are based on the assumption that consumers’ decisions are not rational and are affected by cognitive biases, showed that the use of behavioral tools, such as detailed online information (feedback,social comparison information, information on varying rates (dynamic pricing and general information (advertising campaign, are tools that are not less appropriate than the ones the neoclassical economics offers, mainly because electricity is an invisible product and consumers are unable to assess it by normal cognitive measures. Using an interdisciplinary combination of behavioral tools that come from a variety of approaches taken from a wide variety of different academic fields, it is possible to receive efficient results in the endeavor of reducing electricity demand. Implications: Although the neoclassical economics still remains the fundamental theory used by policymakers, it is recommended to consider behavioral economics as a complementary approach to the neoclassical economics, and combine behavioral tools in the policymakers’ toolbox, especially when those tools do not require a significant financial investment, thus efficiently maximizing the reduction of electricity demand among domestic consumers. These theoretical results will be

  16. Equivalent electricity storage capacity of domestic thermostatically controlled loads

    International Nuclear Information System (INIS)

    Sossan, Fabrizio

    2017-01-01

    A method to quantify the equivalent storage capacity inherent the operation of thermostatically controlled loads (TCLs) is developed. Equivalent storage capacity is defined as the amount of power and electricity consumption which can be deferred or anticipated in time with respect to the baseline consumption (i.e. when no demand side event occurs) without violating temperature limits. The analysis is carried out for 4 common domestic TCLs: an electric space heating system, freezer, fridge, and electric water heater. They are simulated by applying grey-box thermal models identified from measurements. They describe the heat transfer of the considered TCLs as a function of the electric power consumption and environment conditions. To represent typical TCLs operating conditions, Monte Carlo simulations are developed, where models inputs and parameters are sampled from relevant statistical distributions. The analysis provides a way to compare flexible demand against competitive storage technologies. It is intended as a tool for system planners to assess the TCLs potential to support electrical grid operation. In the paper, a comparison of the storage capacity per unit of capital investment cost is performed considering the selected TCLs and two grid-connected battery storage systems (a 720 kVA/500 kWh lithium-ion unit and 15 kVA/120 kWh Vanadium flow redox) is performed. - Highlights: • The equivalent storage capacity of domestic TCLs is quantified • A comparison with battery-based storage technologies is performed • We derive metrics for system planners to plan storage in power system networks • Rule-of-thumb cost indicators for flexible demand and battery-based storage

  17. Analysis of energy saving performance for household refrigerator with thermal storage of condenser and evaporator

    International Nuclear Information System (INIS)

    Cheng, Wen-long; Ding, Miao; Yuan, Xu-dong; Han, Bing-Chuan

    2017-01-01

    Highlights: • A novel refrigerator with both HSC and CSE is proposed. • The operational characteristics of novel refrigerator is analyzed. • The comparison of CSE, HSC and DES refrigerators is analyzed. • DES refrigerator has a largest off-time to on-time ratio of 4.3. • DES refrigerator has the best electrical energy saving performance (32%). - Abstract: The heat transfer performances of evaporators and condensers significantly affect the efficiency of household refrigerators. For enhancing heat transfer of the condensers and evaporators, a novel dual energy storage (DES) refrigerator with both heat storage condenser (HSC) and cold storage evaporator (CSE) is proposed. The performance comparison of three kinds of energy storage refrigerators: HSC refrigerator, CSE refrigerator and DES refrigerator is analyzed by establishing dynamic simulation models. According to the simulation results, the DES refrigerator combines the advantage of HSC refrigerator and CSE refrigerator, it has more balanced operational cycle and higher evaporation pressure and temperature. The DES refrigerator shows a best energy saving performance among the three energy storage refrigerators with largest off-time to on-time ratio of 4.3 and the electrical consumption saving can reach 32%, which is greater than the sum (28%) of the other two kinds of energy storage refrigerators.

  18. Performance measurement of a mini thermoacoustic refrigerator and associated drivers

    OpenAIRE

    Petrina, Denys E.

    2002-01-01

    Approved for public release; distribution is unlimited A miniature Thermoacoustic refrigerator is being developed to cool integrated circuits - which must sometimes operate at high temperatures nearing the upper threshold of their tolerance - to temperature spans more within the circuits' tolerable limits, without the need of the chemicals of a traditional refrigerating system. The development of an electrically powered acoustic driver that powers the thermoacoustic refrigerator is describ...

  19. 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.

  20. Electricity Bill

    International Nuclear Information System (INIS)

    Blair, A.; Beith, A.J.; Hardy, P.

    1989-01-01

    The first part of the debate, which lasted a total of about 7 hours, a verbatim report of the first five of which are included here, was about energy conservation. Several new clauses and amendments were discussed. One would place a duty on the new Director of the Energy Supply industry to promote the efficiency and conservation of energy, another would appoint a Deputy Director with responsibility for energy conservation, and the third would require targets of energy efficiency and pollution reduction to be achieved. This allowed discussion on energy saving by domestic thermal insulation, improved efficiency of heating and refrigeration units and on renewable energy sources especially world energy. The second part of the debate was about access to information regarding health and safety resulting from any activities of the electricity supply industry. The remainder of the debate concerned regional representation and the economics of the electricity supply industry. (UK)

  1. Modeling and calculation of open carbon dioxide refrigeration system

    International Nuclear Information System (INIS)

    Cai, Yufei; Zhu, Chunling; Jiang, Yanlong; Shi, Hong

    2015-01-01

    Highlights: • A model of open refrigeration system is developed. • The state of CO 2 has great effect on Refrigeration capacity loss by heat transfer. • Refrigeration capacity loss by remaining CO 2 has little relation to the state of CO 2 . • Calculation results are in agreement with the test results. - Abstract: Based on the analysis of the properties of carbon dioxide, an open carbon dioxide refrigeration system is proposed, which is responsible for the situation without external electricity unit. A model of open refrigeration system is developed, and the relationship between the storage environment of carbon dioxide and refrigeration capacity is conducted. Meanwhile, a test platform is developed to simulation the performance of the open carbon dioxide refrigeration system. By comparing the theoretical calculations and the experimental results, several conclusions are obtained as follows: refrigeration capacity loss by heat transfer in supercritical state is much more than that in two-phase region and the refrigeration capacity loss by remaining carbon dioxide has little relation to the state of carbon dioxide. The results will be helpful to the use of open carbon dioxide refrigeration

  2. 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.)

  3. Thermodynamic, Environmental and Economic Analyses of Solar Ejector Refrigeration System Application for Cold Storage

    Directory of Open Access Journals (Sweden)

    İbrahim ÜÇGÜL

    2009-02-01

    Full Text Available The refrigeration processes have been widely applied for especially in cold storages. In these plants, the systems working with compressed vapour cooling cycles have been used as a classical method. In general, electrical energy is used for compressing in these processes. Although, mainly the electricity itself has no pollution effect on the environment, the fossil fuels that are widely used to produce electricity in the most of the world, affect the nature terribly. In short, these refrigeration plants, because of the source of the electricity pollute the nature indirectly. However, for compression an ejector refrigeration system requires one of the important renewable energy sources with negligible pollution impact on the environment, namely solar energy from a thermal source. Thermodynamical, environmental and economical aspects of the ejector refrigeration system working with solar energy was investigated in this study. As a pilot case, apple cold storage plants widely used in ISPARTA city, which 1/5 th of apple production of TURKEY has been provided from, was chosen. Enviromental and economical advantages of solar ejector refrigeration system application for cold storage dictated by thermodynamic, economic and enviromental analyses in this research.

  4. A potential candidate for the sustainable and reliable domestic energy generation–Thermoelectric cogeneration system

    International Nuclear Information System (INIS)

    Zheng, X.F.; Yan, Y.Y.; Simpson, K.

    2013-01-01

    Due to being solid-state, noiseless and maintenance free, thermoelectric devices have found wide applications in different areas since they were discovered over 180 years ago. The applications are concerned with environment-friendly refrigeration and power generation in transportation tools, industrial utilities, military devices, medical services and space applications. It is utilisation of waste heat in varying applications that make the modules particularly attractive. Nevertheless, despite a few academic papers, there has not been extensive use in the domestic sector. A concept of thermoelectric cogeneration system (‘TCS’) is proposed to highlight the direction for enhancing the sustainability by improving the energy efficiency in domestic sector. Compared to the thermoelectric systems used in other areas which only uses the part of converted energy but wastes the unconverted part by dissipating it into the environment, the system presented here maximally recover the available heat by generating electrical power and producing hot water simultaneously. The viability of this system concept is evaluated on a bench-scale experimental prototype. The outputs of electrical power and hot water have been investigated at different temperature difference. The cost saving potential and cost recovery period have been estimated using the available heat sources in domestic sector. The results intend to provide reference for developing the real-scale domestic thermoelectric cogeneration system and show the potential benefits

  5. Improvement in performance of a direct solar-thermally driven diffusion-absorption refrigerator; Leistungssteigerung einer direkt solarthermisch angetriebenen Diffusions-Absorptionskaeltemaschine

    Energy Technology Data Exchange (ETDEWEB)

    Schmid, Fabian; Bierling, Bernd; Spindler, Klaus [Stuttgart Univ. (Germany). Inst. fuer Thermodynamik und Waermetechnik (ITW)

    2012-07-01

    The diffusion-absorption refrigeration process offers the possibility of a wear-free refrigeration system without electricity and noise. At the Institute for Thermodynamics and Thermal Engineering (Stuttgart, Federal Republic of Germany), a decentralized solar refrigeration system is developed based on this process. The expeller and the thermosiphon pump of this process are integrated in the collector, and thus are heated directly. The diffusion-absorption refrigeration process also can be used for domestic water heating by means of a second cycle in the collector. A cooling capacity of 400 W is to be achieved for each solar collector (2.5 m{sup 2}). Several refrigeration systems can be modular interconnected for higher cooling capacities. As part of the DKV Conference 2011, the construction of the plant, the first measurement data and results were presented. Since then, both the cooling capacity and the coefficient of performance of the diffusion-absorption refrigeration system could be increased significantly. For this, solvent heat exchanger, evaporator, absorber and gas heat exchanger have been optimized in terms of system efficiency. In addition, a stable system operation could be achieved by means of a bypass line. About this line, an exaggerated refrigerant already is removed in the solvent heat exchanger. In addition, a condensate pre-cooler was integrated in order to increase the efficiency. For a detailed investigation of the auxiliary gas cycle facilities, the volume flow and the concentration of the auxiliary gas circuit were examined under utilization of an ultrasonic sensor. In order to evaluate the influence factors by means of a parametric study, the mass transfer in the auxiliary gas circuit was simulated using the two-fluid model. The results of these studies, the current system configuration and the current results are presented in the contribution under consideration.

  6. An Optimal Domestic Electric Vehicle Charging Strategy for Reducing Network Transmission Loss While Taking Seasonal Factors into Consideration

    Directory of Open Access Journals (Sweden)

    Yuancheng Zhao

    2018-01-01

    Full Text Available With the rapid growth of domestic electric vehicle charging loads, the peak-valley gap and power fluctuation rate of power systems increase sharply, which can lead to the increase of network losses and energy efficiency reduction. This paper tries to regulate network loads and reduce power system transmission loss by optimizing domestic electric vehicle charging loads. In this paper, a domestic electric vehicle charging loads model is first developed by analyzing the key factors that can affect users’ charging behavior. Subsequently, the Monte Carlo method is proposed to simulate the power consumption of a cluster of domestic electric vehicles. After that, an optimal electric vehicle charging strategy based on the 0-1 integer programming is presented to regulate network daily loads. Finally, by taking the IEEE33 distributed power system as an example, this paper tries to verify the efficacy of the proposed optimal charging strategy and the necessity for considering seasonal factors when scheduling electric vehicle charging loads. Simulation results show that the proposed 0-1 integer programming method does have good performance in reducing the network peak-valley gap, voltage fluctuation rate, and transmission loss. Moreover, it has some potential to further reduce power system transmission loss when seasonal factors are considered.

  7. Quantum-Circuit Refrigerator

    Science.gov (United States)

    MöTtöNen, Mikko; Tan, Kuan Y.; Masuda, Shumpei; Partanen, Matti; Lake, Russell E.; Govenius, Joonas; Silveri, Matti; Grabert, Hermann

    Quantum technology holds great potential in providing revolutionizing practical applications. However, fast and precise cooling of the functional quantum degrees of freedom on demand remains a major challenge in many solid-state implementations, such as superconducting circuits. We demonstrate direct cooling of a superconducting resonator mode using voltage-controllable quantum tunneling of electrons in a nanoscale refrigerator. In our first experiments on this type of a quantum-circuit refrigerator, we measure the drop in the mode temperature by electron thermometry at a resistor which is coupled to the resonator mode through ohmic losses. To eliminate unwanted dissipation, we remove the probe resistor and directly observe the power spectrum of the resonator output in agreement with the so-called P(E) theory. We also demonstrate in microwave reflection experiments that the internal quality factor of the resonator can be tuned by orders of magnitude. In the future, our refrigerator can be integrated with different quantum electric devices, potentially enhancing their performance. For example, it may prove useful in the initialization of superconducting quantum bits and in dissipation-assisted quantum annealing. We acknowledge European Research Council Grant SINGLEOUT (278117) and QUESS (681311) for funding.

  8. POWER EFFICIENCY OPPORTUNITIES FOR INDUSTRIAL REFRIGERATION SYSTEM OF FOOD PROCESSING ENTERPRISE

    Directory of Open Access Journals (Sweden)

    O. Ostapenko

    2016-12-01

    Full Text Available Rising prices on power supply are forcing business owners to search the ways of operating costs reducing. Refrigeration system in the food industry is a major source of power consumption. The utilization of cold accumulation systems allows reducing of refrigeration unit power consumption. In this paper the refrigeration system with a system of cold accumulation and dry cooling tower is considered. The possibility of power consumption reducing due to the organization of the enterprise refrigeration system operation process in the night period according to electricity multiple tariffs has been analyzed.

  9. Demonstration of the Use of Remote Temperature Monitoring Devices in Vaccine Refrigerators in Haiti.

    Science.gov (United States)

    Cavallaro, Kathleen F; Francois, Jeannot; Jacques, Roody; Mentor, Derline; Yalcouye, Idrissa; Wilkins, Karen; Mueller, Nathan; Turner, Rebecca; Wallace, Aaron; Tohme, Rania A

    After the 2010 earthquake, Haiti committed to introducing 4 new antigens into its routine immunization schedule, which required improving its cold chain (ie, temperature-controlled supply chain) and increasing vaccine storage capacity by installing new refrigerators. We tested the feasibility of using remote temperature monitoring devices (RTMDs) in Haiti in a sample of vaccine refrigerators fueled by solar panels, propane gas, or electricity. We analyzed data from 16 RTMDs monitoring 24 refrigerators in 15 sites from March through August 2014. Although 5 of the 16 RTMDs exhibited intermittent data gaps, we identified typical temperature patterns consistent with refrigerator door opening and closing, propane depletion, thermostat insufficiency, and overstocking. Actual start-up, annual maintenance, and annual electricity costs for using RTMDs were $686, $179, and $9 per refrigerator, respectively. In Haiti, RTMD use was feasible. RTMDs could be prioritized for use with existing refrigerators with high volumes of vaccines and new refrigerators to certify their functionality before use. Vaccine vial monitors could provide additional useful information about cumulative heat exposure and possible vaccine denaturation.

  10. Application of high-resolution domestic electricity load profiles in network modelling

    DEFF Research Database (Denmark)

    Marszal, Anna Joanna; Mendaza, Iker Diaz de Cerio; Heiselberg, Per Kvols

    2016-01-01

    the generated profiles are inputted in a low-voltage network model created in DIgSILENT PowerFactory. By means of employing 1 hour based demand and generation profiles in during dynamic studies, the representation of the local power system performance might sometimes not be as accurate as needed. In the test...... with modeling when 1-minute domestic electricity demand and generation profiles are used as inputs. The analysis is done with a case study of low-voltage network located in Northern Denmark. The analysis includes two parts. The first part focuses on modeling the domestic demands and on-site generation in 1......-minute resolution. The load profiles of the household appliances are created using a bottom-up model, which uses the 1-minute cycle power use characteristics of a single appliance as the main building block. The profiles of heavy electric appliances, such as heat pump, are not included in the above...

  11. Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks.

    Science.gov (United States)

    Dufresne, S F; Locas, M C; Duchesne, A; Restieri, C; Ismaïl, J; Lefebvre, B; Labbé, A C; Dion, R; Plante, M; Laverdière, M

    2012-01-01

    Sporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated with Legionella spp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the same Legionella isolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study. Legionella was recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

  12. Alternative test method to assess the energy performance of frost-free refrigerating appliances

    International Nuclear Information System (INIS)

    Hermes, Christian J.L.; Melo, Cláudio; Knabben, Fernando T.

    2013-01-01

    This paper outlines an alternative test method to evaluate the energy consumption of frost-free refrigerators and freezers for residential applications. While the standardized methods require the refrigerating appliance to be kept running according to its onboard control system, which usually drives the refrigerator through an on–off cycling pattern, the proposed approach assesses the refrigerator energy performance in the steady-state regime, being therefore much faster and more reliable. In this procedure, the cooling capacity is matched to the cooling loads by PID-controlled electrical heaters installed within the refrigerated compartments, so that the compartment temperatures are kept at the desired standardized levels. Comparisons between the experimental results obtained using the steady-state energy test and the standardized procedures showed that the former follows closely the trends observed for the latter. - Highlights: ► An alternative test method to assess the energy consumption of refrigerators is proposed. ► PID-controlled electrical heaters were installed within the compartments. ► Steady-state and ISO energy tests were performed and compared. ► Both proposed and standardized test procedures showed similar trends.

  13. Thermodynamic design of hydrogen liquefaction systems with helium or neon Brayton refrigerator

    Science.gov (United States)

    Chang, Ho-Myung; Ryu, Ki Nam; Baik, Jong Hoon

    2018-04-01

    A thermodynamic study is carried out for the design of hydrogen liquefaction systems with helium (He) or neon (Ne) Brayton refrigerator. This effort is motivated by our immediate goal to develop a small-capacity (100 L/h) liquefier for domestic use in Korea. Eight different cycles are proposed and their thermodynamic performance is investigated in comparison with the existing liquefaction systems. The proposed cycles include the standard and modified versions of He Brayton refrigerators whose lowest temperature is below 20 K. The Brayton refrigerator is in direct thermal contact with the hydrogen flow at atmospheric pressure from ambient-temperature gas to cryogenic liquid. The Linde-Hampson system pre-cooled by a Ne Brayton refrigerator is also considered. Full cycle analysis is performed with the real properties of fluids to estimate the figure of merit (FOM) under an optimized operation condition. It is concluded that He Brayton refrigerators are feasible for this small-scale liquefaction, because a reasonably high efficiency can be achieved with simple and safe (low-pressure) operation. The complete cycles with He Brayton refrigerator are presented for the development of a prototype, including the ortho-to-para conversion.

  14. Gross domestic product estimation based on electricity utilization by artificial neural network

    Science.gov (United States)

    Stevanović, Mirjana; Vujičić, Slađana; Gajić, Aleksandar M.

    2018-01-01

    The main goal of the paper was to estimate gross domestic product (GDP) based on electricity estimation by artificial neural network (ANN). The electricity utilization was analyzed based on different sources like renewable, coal and nuclear sources. The ANN network was trained with two training algorithms namely extreme learning method and back-propagation algorithm in order to produce the best prediction results of the GDP. According to the results it can be concluded that the ANN model with extreme learning method could produce the acceptable prediction of the GDP based on the electricity utilization.

  15. Enhancement of isobutane refrigerator performance by using far-infrared coating

    International Nuclear Information System (INIS)

    Hsu, Yu-Chun; Teng, Tun-Ping

    2016-01-01

    Highlights: • Two-step synthesis method was employed to produce FIRCs. • Emissivity of FIRCs was determined using a FT-IR. • The highest emissivity of FIRMs was MWCNT. • No-load pull-down and 24-h on-load cycling test were performed. • The COP and EF of S2 were greater than those of S1 by 5.92% and 7.89%. - Abstract: This study evaluated the effect on refrigeration performance and feasibility of a far-infrared coating (FIRC) on the condenser of a small isobutane (R-600a) refrigerator. The evaluation was based on the no-load pull-down and 24-h on-load cycling tests. Far-infrared materials and a water-based coating material were mixed using a two-step synthesis method to obtain the FIRC material. Fourier transform infrared spectrometry established that the optimal far-infrared material was a multiwalled carbon nanotube (MWCNT). The results of the no-load pull-down test revealed that the electricity consumption, freezer temperature, and coefficient of performance (COP) of the R-600a refrigerator with MWCNT-FIRC (S2) were lower than those of the refrigerator without MWCNT-FIRC (S1) by 3.39%, 3.61%, and 2.92%, respectively. The results of the 24-h on-load cycling test showed that S2 had a lower electricity consumption, higher slope of pull-down (SPD), higher compression ratio (CR), higher COP, lower duty ratio (DR), and higher energy factor (EF), changing upon those of S1 by −7.05%, 5.66%, 3.24%, 5.92%, −5.63, and 7.89%, respectively. A MWCNT-FIRC on the condenser of an R-600a refrigerator can enhance refrigeration performance and reduce electricity consumption, resulting in energy saving and carbon reduction.

  16. Conception and simulation of an improved solar refrigeration unit

    International Nuclear Information System (INIS)

    Chaouachi, B.; Gabsi, S.

    2006-01-01

    If the solar energy possesses the advantage to be c lean , free and new able, this last is probably, considered like an adapted potential solution, that answers in even time at a economic preoccupation and ecological problems. Among the main done currently research is the use of free source to make operate system of refrigeration. following a bibliographic study on the absorption cycles, the utilized couples absorbents-refrigerating fluids and the capture of the solar energy, an unit refrigeration using an improved solar absorption cycle of ammonia has been conceived and studied. The simulation results in permanent regime concerned the determination of the variation of the performance criteria mainly according to the operatives kept for this study. The obtained results showed, that the improved mono pressure absorption cycle of ammonia is suitable well for the cold production by means of the solar energy and that with a simple plate collector we can reach a power, of the order of 900 watts sufficient for domestic use.(Author)

  17. 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.

  18. Control optimizations for heat recovery from CO2 refrigeration systems in supermarket

    International Nuclear Information System (INIS)

    Ge, Y.T.; Tassou, S.A.

    2014-01-01

    Highlights: • Application of supermarket energy control system model. • Heat recovery from CO 2 refrigeration system in supermarket space conditioning. • Effect of pressure controls of CO 2 refrigeration system on heat recovery potentials. • Control optimization of CO 2 refrigeration system for heat recovery in supermarket. - Abstract: A modern supermarket energy control system has a concurrent need for electricity, food refrigeration and space heating or cooling. Approximately 10% of this energy is for conventional gas-powered heating. In recent years, the use of CO 2 as a refrigerant in supermarket systems has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. CO 2 refrigeration systems also offer more compact component designs over a conventional HFC system and heat recovery potential from compressor discharge. In this paper, the heat recovery potential of an all-CO 2 cascade refrigeration system in a supermarket has been investigated using the supermarket simulation model “SuperSim” developed by the authors. It has been shown that at UK weather conditions, the heat recovery potential of CO 2 refrigeration systems can be increased by increasing the condenser/gas cooler pressure to the point where all the heat requirements are satisfied. However, the optimum level of heat recovery will vary during the year and the control system should be able to continuously optimize this level based on the relative cost of energy, i.e., gas and electricity

  19. The impact of the development of external markets for electricity on the domestic price in Quebec

    International Nuclear Information System (INIS)

    St-Amour, Y.

    1990-03-01

    A study was conducted to establish the sensitivity of the average price of electricity in the domestic Quebec market with respect to the volume of electricity exported. Economic data are presented on electricity in relation to other forms of energy in the northwest North American continental framework. The state of electricity exports and the hydroelectric potential of Quebec with respect to the capacity of neighboring networks to utilize this potential are discussed. CANREM (Canadian Regionalized Electricity Model) is described and used to simulate the effect of electric power exports on the Quebec electricity price over a 23-year period starting in 1987. Three simulation scenarios are presented and analyzed. The results obtained indicate a significant increase in the domestic price during the time that generation and transmission installation is being carried out. In contrast, during the years when service is offered, the slowing of the increase in the price of electricity is the determining factor with regard to the net social gain which can be achieved over the long term for Quebec society. 75 refs., 10 figs., 18 tabs

  20. 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

  1. Method and refrigerants for replacing existing refrigerants in centrifugal compressors

    International Nuclear Information System (INIS)

    Kopko, W.L.

    1991-01-01

    This patent describes a method for replacing an existing refrigerant in a centrifugal compressor. It comprises selecting a desired impeller Mach number for the centrifugal compressor; selecting a base refrigerant constituent; combining at least one additive refrigerant constituent with the base refrigerant constituent to form a replacement refrigerant having at least one physical or chemical property different from the existing refrigerant and substantially providing the desired impeller Mach number in the centrifugal compressor; and replacing the existing refrigerant with the replacement refrigerant

  2. The effect of electricity and gas losses on Nigeria`s Gross Domestic ...

    African Journals Online (AJOL)

    The effect of electricity and gas losses on Nigeria`s Gross Domestic Product. ... PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals ... West African Journal of Industrial and Academic Research. Journal Home ... Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  3. Study of some aspects of the long-run domestic demand for electricity in New Zealand

    Energy Technology Data Exchange (ETDEWEB)

    Stent, A F

    1982-01-01

    This study investigates the long-run domestic demand for electricity in New Zealand over the period 1945 to 1972. The first part analyzes the ownership of electrical appliances using data from the five yearly censuses of population and dwellings. A dynamic appliance ownership model is developed for the analysis. This model explains the proportion of households, in small regional districts, with ownership status of a particular appliance type when observed at census time. It measures the effects of prices, income, and household taste characteristics on ownership. The main results include estimates of long-run electricity price effects. The second part of the thesis estimates dynamic demand equations for electricity. A flow-adjustment model is fitted to moving cross sections of data for individual Electrical Supply Authority districts in the North and South Islands separately. The final part of the thesis undertakes a synthesis of electricity price effects on appliance ownership (from the first part) and electricity demand (from the second part). This indicates substantial consistency in the estimates obtained. The main conclusions for electricity price are that this variable has been a significant factor in explaining the variation in domestic electricity consumption over the period; that the relationship has been inelastic in the later part, in both short and long-runs; and that long-run effects are mainly via the use of the electrical services.

  4. Performance of an auto refrigerant cascade refrigerator operating in gas refrigerant supply (GRS) mode with nitrogen-hydrocarbon and argon-hydrocarbon refrigerants

    Science.gov (United States)

    Gurudath Nayak, H.; Venkatarathnam, G.

    2009-07-01

    There is a worldwide interest in the development of auto refrigerant cascade (ARC) refrigerators operating with refrigerant mixtures. Both flammable and non-flammable refrigerant mixtures can be used in these systems. The performance of an ARC system with optimum nitrogen-hydrocarbon and argon-hydrocarbon mixtures between 90 and 160 K is presented in this paper.

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

    Science.gov (United States)

    Gaul, Christopher J.

    2001-01-01

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

  6. 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.

  7. 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.

  8. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Hao; Wu Guo-Xing

    2013-01-01

    An irreversible Ericsson refrigeration cycle model is established, in which multi-irreversibilities such as finite-rate heat transfer, regenerative loss, heat leakage, and the efficiency of the regenerator are taken into account. Expressions for several important performance parameters, such as the cooling rate, coefficient of performance (COP), power input, exergy output rate, entropy generation rate, and ecological function are derived. The influences of the heat leakage and the time of the regenerative processes on the ecological performance of the refrigerator are analyzed. The optimal regions of the ecological function, cooling rate, and COP are determined and evaluated. Furthermore, some important parameter relations of the refrigerator are revealed and discussed in detail. The results obtained here have general significance and will be helpful in gaining a deep understanding of the magnetic Ericsson refrigeration cycle. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  9. 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.

  10. Performance and energy saving analysis of a refrigerator using hydrocarbon mixture (HC-R134a) as working fluid

    Science.gov (United States)

    Mohtar, M. N.; Nasution, H.; Aziz, A. A.

    2015-12-01

    The use of hydrocarbon mixture as a working fluid in a refrigerator system is rarely explored. Almost all domestic refrigerators use hydroflourocarbon R134a (HFC-R134a) as refrigerants. In this study, hydrocarbon gas (HC-R134a) is used as the alternative refrigerant to replace HFC-R134a. It has a composition of R290 (56%), R600a (54.39%) and additive (0.1%wt) blended for the trials. The experiments were conducted with 105 g and 52.5 g refrigerant mass charge, subjected to internal heat load of 0, 1, 2, 3 and 4 kg respectively. The study investigates the coefficient of performance of the refrigerator (COPR) and energy consumption. The results show that the use of HC-R134a as the replaceable refrigerant can save energy ranging from 2.04% to 7.09%, as compared to the conventional HFC-R134a refrigerant. Naturally, the COPR improvement and temperature distribution using HC-R134a are much better than HFC-R134a

  11. 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.

  12. Computer model of the refrigeration system of an ice rink

    Energy Technology Data Exchange (ETDEWEB)

    Teyssedou, G.; Zmeureanu, R. [Concordia Univ., Centre for Building Studies, Montreal, PQ (Canada). Dept. of Building, Civil and Environmental Engineering; Giguere, D. [Natural Resources Canada, Varennes, PQ (Canada). CANMET Energy Technology Centre

    2008-07-01

    This paper presented a refrigeration system model of an existing ice rink using a component approach. The chillers, the ice-concrete slab and the controller were the 3 main components used in the simulations which were performed using both open and closed loop systems. The simulated ice rink refrigeration system was based on measurements taken in an existing indoor ice rink located in Montreal, Quebec. Measurements of the refrigeration system included electricity demand; heat flux on the ice sheet; exterior air temperature; ice temperature; return brine temperature; brine temperature at the pump; brine temperature at both evaporator exits; and refrigerant temperature and pressure at the expansion and condenser valve exits. Simulation results and measurements were found to be in good agreement. A computer model of the refrigeration system was developed using the TRNSYS 16 program. The refrigeration system was composed of 2 chillers using refrigerant R-22. The impact of heat recovery from the condensers on the energy demand for sanitary water heating was also estimated. The potential reduction of equivalent carbon dioxide emissions was calculated using the total equivalent warming impact (TEWI) criterion in an effort to estimate the refrigeration impact on global warming. 12 refs., 4 tabs., 12 figs.

  13. Being everything to anyone: Applicability of thermoacoustic technology in the commercial refrigeration market

    Science.gov (United States)

    Poese, Matthew E.; Smith, Robert W. M.; Garrett, Steven L.

    2005-09-01

    This talk will compare electrodynamically driven thermoacoustic refrigeration technology to some common implementations of low-lift vapor-compression technology. A rudimentary explanation of vapor-compression refrigeration will be presented along with some of the implementation problems faced by refrigeration engineers using compressor-based systems. These problems include oil management, compressor slugging, refrigerant leaks and the environmental impact of refrigerants. Recently, the method of evaluating this environmental impact has been codified to include the direct effects of the refrigerants on global warming as well as the so-called ``indirect'' warming impact of the carbon dioxide released during the generation (at the power plant) of the electrical power consumed by the refrigeration equipment. It is issues like these that generate commercial interest in an alternative refrigeration technology. However, the requirements of a candidate technology for adoption in a mature and risk-averse commercial refrigeration industry are as hard to divine as they are to meet. Also mentioned will be the state of other alternative refrigeration technologies like free-piston Stirling, thermoelectric and magnetocaloric as well as progress using vapor compression technology with alternative refrigerants like hydrocarbons and carbon dioxide.

  14. CFD simulations and reduced order modeling of a refrigerator compartment including radiation effects

    International Nuclear Information System (INIS)

    Bayer, Ozgur; Oskay, Ruknettin; Paksoy, Akin; Aradag, Selin

    2013-01-01

    Highlights: ► Free convection in a refrigerator is simulated including radiation effects. ► Heat rates are affected drastically when radiation effects are considered. ► 95% of the flow energy can be represented by using one spatial POD mode. - Abstract: Considering the engineering problem of natural convection in domestic refrigerator applications, this study aims to simulate the fluid flow and temperature distribution in a single commercial refrigerator compartment by using the experimentally determined temperature values as the specified constant wall temperature boundary conditions. The free convection in refrigerator applications is evaluated as a three-dimensional (3D), turbulent, transient and coupled non-linear flow problem. Radiation heat transfer mode is also included in the analysis. According to the results, taking radiation effects into consideration does not change the temperature distribution inside the refrigerator significantly; however the heat rates are affected drastically. The flow inside the compartment is further analyzed with a reduced order modeling method called Proper Orthogonal Decomposition (POD) and the energy contents of several spatial and temporal modes that exist in the flow are examined. The results show that approximately 95% of all the flow energy can be represented by only using one spatial mode

  15. Optimal household refrigerator replacement policy for life cycle energy, greenhouse gas emissions, and cost

    International Nuclear Information System (INIS)

    Kim, Hyung Chul; Keoleian, Gregory A.; Horie, Yuhta A.

    2006-01-01

    Although the last decade witnessed dramatic progress in refrigerator efficiencies, inefficient, outdated refrigerators are still in operation, sometimes consuming more than twice as much electricity per year compared with modern, efficient models. Replacing old refrigerators before their designed lifetime could be a useful policy to conserve electric energy and greenhouse gas emissions. However, from a life cycle perspective, product replacement decisions also induce additional economic and environmental burdens associated with disposal of old models and production of new models. This paper discusses optimal lifetimes of mid-sized refrigerator models in the US, using a life cycle optimization model based on dynamic programming. Model runs were conducted to find optimal lifetimes that minimize energy, global warming potential (GWP), and cost objectives over a time horizon between 1985 and 2020. The baseline results show that depending on model years, optimal lifetimes range 2-7 years for the energy objective, and 2-11 years for the GWP objective. On the other hand, an 18-year of lifetime minimizes the economic cost incurred during the time horizon. Model runs with a time horizon between 2004 and 2020 show that current owners should replace refrigerators that consume more than 1000 kWh/year of electricity (typical mid-sized 1994 models and older) as an efficient strategy from both cost and energy perspectives

  16. 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%.

  17. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1998-03-15

    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 thermophysical properties, compatibility, environmental, safety, application and other information. It provides corresponding information on older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air conditioning and refrigeration equipment. It also references documents addressing compatibility of refrigerants and lubricants with other materials.

  18. Experience of Using Domestic High-Frequency Electric Welding Technology in Surgical Treatment of Patients with Abdominal Pathology

    Directory of Open Access Journals (Sweden)

    A.M. Babiy

    2014-04-01

    Full Text Available The article presents the experience of using electric welding technology of biological tissues with domestic high-frequency electrical generator EC 300 M1 in 176 patients at open and laparoscopic surgery for abdominal pathology. The analysis of findings showed that electric welding of living tissue provides reliable hemostasis, promotes tissue repair after their separation.

  19. Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigeration for lesser developed countries

    Science.gov (United States)

    Erickson, Donald C.

    1990-02-01

    The Intermittent Solar Ammonia Absorption Cycle (ISAAC) refrigerator is a solar thermal technology which provides low cost, efficient, reliable ice-making to areas without ready access to electricity. An ISAAC refrigeration system consists of a compound parabolic solar collector, two pressure vessels, a condenser, a cold box or refrigerated space, and simple connective piping -- no moving parts or electrical components. Most parts are simple construction or plumbing grade materials, locally available in many remote areas. This technology has numerous potential benefits in lesser developed countries both by providing a cheap, reliable source of ice, and, since manufacture requires only semi-skilled labor, a source of employment to the local economy. Applications include vaccine storage for health care clinics; fish, meat, and dairy product storage; and personal consumption. Importantly, this technology increases the quality of life for people in lesser developed countries without depleting fossil fuel resources or increasing the release of greenhouse gases such as CO2 and chlorofluorocarbons.

  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. Dynamic model of an autonomous solar absorption refrigerator

    International Nuclear Information System (INIS)

    Ali Fellah; Tahar Khir; Ammar Ben Brahim

    2009-01-01

    The performance analysis of a solar absorption refrigerator operating in an autonomous way is investigated. The water/LiBr machine satisfies the air-conditioning needs along the day. The refrigerator performances were simulated regarding a dynamic model. For the solar driven absorption machines, two applications could be distinguished. The sun provides the thermal part of the useful energy. In this case, it is necessary to use additional energy as the electric one to activate the pumps, the fans and the control system. On the other hand, the sun provides all the necessary energy. Here, both photovoltaic cells and thermal concentrators should be used. The simulation in dynamic regime of the cycle requires the knowledge of the geometric characteristics of every component as the exchange areas and the internal volumes. Real characteristics of a refrigerator available at the applied thermodynamic research unit (ATRU) at the engineers' national school of Gabes are notified. The development of the thermal and matter balances in every component of the cycle has permitted to simulate in dynamic regime the performances of a solar absorption refrigerator operating with the water/LiBr couple for air-conditioning needs. The developed model could be used to perform intermittent refrigeration cycle autonomously driven. (author)

  2. 78 FR 25724 - Petition for Waiver of GE Appliances From the Department of Energy Residential Refrigerator and...

    Science.gov (United States)

    2013-05-02

    ... refrigerators and refrigerator-freezers that are the focus of this notice.\\1\\ Part B includes definitions, test... division of General Electric Co., (``GE'') is a leading manufacturer and marketer of household appliances...

  3. PIV measurement of the flow field in a domestic refrigerator model: Comparison with 3D simulations

    Energy Technology Data Exchange (ETDEWEB)

    Ben Amara, S.; Laguerre, O.; Flick, D. [UMR Genie Industriel Alimentaire (Cemagref-AgroParisTech-INRA) - Cemagref, Parc de Tourvoie, BP 44, 92185 Antony Cedex (France); Charrier-Mojtabi, M.-C.; Lartigue, B. [Universite Paul Sabatier, Laboratoire PHASE, E.A. 3208, 118 route de Narbonne, 31062 Toulouse Cedex 4 (France)

    2008-12-15

    PIV (particle image velocimetry) measurements of flow field due to natural convection in a parallelepipedic enclosure representing a domestic refrigerator model (scale 1) have been undertaken in order to determine the thickness of the hydrodynamic boundary layers and to study the flow motions depending on the boundary conditions applied on the vertical walls. One of the vertical walls is maintained at a negative and constant temperature either on the totality or on one part of its surface: this wall acts as the evaporator. The other walls are in contact with external air at constant temperature. The velocity measurements have been made in the symmetry plane of the enclosure. Unsteady recirculations have been observed at the bottom of the cavity. The influence of both the temperature and the dimension of the cold wall has been studied. Numerical simulations using CFD software (Fluent) have been then performed. In the numerical model, we assumed that the temperature of the evaporator is constant while an uniform global heat transfer coefficient has been used to describe the heat exchange with the external air at constant temperature. We considered laminar 3D flows and took into account the heat transfer by radiation between the different walls of the cavity. The results obtained with the 3D numerical simulations are in quite good agreement with the experimental airflow measurements using the PIV technique. (author)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. A compact rotating dilution refrigerator

    Science.gov (United States)

    Fear, M. J.; Walmsley, P. M.; Chorlton, D. A.; Zmeev, D. E.; Gillott, S. J.; Sellers, M. C.; Richardson, P. P.; Agrawal, H.; Batey, G.; Golov, A. I.

    2013-10-01

    We describe the design and performance of a new rotating dilution refrigerator that will primarily be used for investigating the dynamics of quantized vortices in superfluid 4He. All equipment required to operate the refrigerator and perform experimental measurements is mounted on two synchronously driven, but mechanically decoupled, rotating carousels. The design allows for relative simplicity of operation and maintenance and occupies a minimal amount of space in the laboratory. Only two connections between the laboratory and rotating frames are required for the transmission of electrical power and helium gas recovery. Measurements on the stability of rotation show that rotation is smooth to around 10-3 rad s-1 up to angular velocities in excess of 2.5 rad s-1. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

  9. Refrigeration requirements for fusion reactors based upon the theta-pinch concept

    International Nuclear Information System (INIS)

    Williamson, K.D. Jr.; King, C.R.

    1976-01-01

    Two refrigeration systems applicable to the theta-pinch fusion concept are described. The first is a 1100 W, 4.5 K refrigerator which will be used for testing superconducting NbTi Magnetic Energy Transfer and Storage (METS) coil systems. This unit is currently being installed and is to be operational by April 1977. The second unit is applicable to the Syllac Fusion Test Reactor (SFTR) and has been conceptually designed. This liquefier-refrigerator is about 22 times larger than those in existence at present and will require 12-MW input electrical power. It will provide 3045 kg/h of liquid helium at 4.5 K

  10. Effects of Coupling Lens on Optical Refrigeration of Semiconductors

    International Nuclear Information System (INIS)

    Kai, Ding; Yi-Ping, Zeng

    2008-01-01

    Optical refrigeration of semiconductors is encountering efficiency difficulties caused by nonradiative recombination and luminescence trapping. A commonly used approach for enhancing luminescence efficiency of a semiconductor device is coupling a lens with the device. We quantitatively study the effects of a coupling lens on optical refrigeration based on rate equations and photon recycling, and calculated cooling efficiencies of different coupling mechanisms and of different lens materials. A GaAs/GaInP heterostructure coupled with a homo-epitaxial GaInP hemispherical lens is recommended. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Natural refrigerants. Future heat pumps for district heating; Naturliga koeldmedier. Framtida vaermepumpar foer fjaerrvaerme

    Energy Technology Data Exchange (ETDEWEB)

    Ingvarsson, Paul; Steen Ronnermark, Ingela [Fortum Teknik och Miljoe AB, Stockholm (Sweden); Eriksson, Marcus [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Chemical Engineering and Environmental Science

    2004-01-01

    International work on refrigerants is aiming at phasing out HFC. The solution might be natural refrigerants. Within 15-20 years, when present heat pumps for district heating in Sweden are likely not in service any longer, it might still be good economy to install new heat pumps since only the machines need to be replaced. This report describes the possibilities to use natural refrigerants. A first screening resulted in further study on some hydrocarbons, ammonia and carbon dioxide. Water was considered to require too large volumes. In present plants it is practically not possible to use any natural refrigerants, partly because the compressors are not adapted. In new plants the situation is different. Today it is technically possible to install new heat pumps in the studied size, 15 MW{sub th}, using ammonia or hydrocarbons as refrigerant. But likely it is very difficult to get permits from authorities since the refrigerants are toxic or highly flammable. There is substantial international research on using carbon dioxide, and this refrigerant is also used in some applications. Carbon dioxide is used at high pressure and in a trans-critical process. Surprisingly, it turned out that one compressor manufacturer considers it possible to supply a heat pump for district heating within 5 years. This development has taken place in Russia, mainly for domestic use. Thus, within 15 to 20 years there will probably exist a technique where carbon dioxide is used. However, more development is needed. Additionally, low district heating return temperatures are also needed to get an acceptable COP. The investment cost for a heat pump installation is considered to be approx. 30 % higher when using ammonia or propane compared to using R134a. When using carbon dioxide there is in the longer run potential to get lower cost than for R134a. The COPs are almost identical if the systems are properly designed. In the carbon dioxide case the COP is somewhat lower, but has a potential for

  12. ARTI refrigerant database

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-15

    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. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date. The database identifies sources of specific information on refrigerants. It addresses lubricants including alkylbenzene, polyalkylene glycol, polyolester, and other synthetics as well as mineral oils. It also references documents addressing compatibility of refrigerants and lubricants with metals, plastics, elastomers, motor insulation, and other materials used in refrigerant circuits. Incomplete citations or abstracts are provided for some documents. They are included to accelerate availability of the information and will be completed or replaced in future updates. Citations in this report are divided into the following topics: thermophysical properties; materials compatibility; lubricants and tribology; application data; safety; test and analysis methods; impacts; regulatory actions; substitute refrigerants; identification; absorption and adsorption; research programs; and miscellaneous documents. Information is also presented on ordering instructions for the computerized version.

  13. 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.

  14. Installation and Commissioning of the Helium Refrigeration System for the HANARO-CNS

    International Nuclear Information System (INIS)

    Choi, Jung Woon; Kim, Young Ki; Wu, Sang Ik; Son, Woo Jung

    2009-11-01

    The cold neutron source (CNS), which will be installed in the vertical CN hole of the reflector tank at HANARO, makes thermal neutrons to moderate into the cold neutrons with the ranges of 0.1 ∼ 10 meV passing through a moderator at about 22K. A moderator to produce cold neutrons is liquid hydrogen, which liquefies by the heat transfer with cryogenic helium flowing from the helium refrigeration system. For the maintenance of liquid hydrogen in the IPA, the CNS system is mainly consisted of the hydrogen system to supply the hydrogen to the IPA, the vacuum system to keep the cryogenic liquid hydrogen in the IPA, and the helium refrigeration system to liquefy the hydrogen gas. The helium refrigeration system can be divided into two sections: one is the helium compression part from the low pressure gas to the high pressure gas and the other is the helium expansion part from the high temperature gas and pressure to low temperature and pressure gas by the expansion turbine. The helium refrigeration system except the warm helium pipe and the helium buffer tank has been manufactured by Linde Kryotechnik, AG in Switzerland and installed in the research reactor hall, HANARO. Other components have been manufactured in the domestic company. This technical report deals with the issues, its solutions, and other particular points while the helium refrigeration system was installed at site, verified its performance, and conducted its commissioning along the reactor operation. Furthermore, the operation procedure of the helium refrigeration system is included in here for the normal operation of the CNS

  15. Energy consumption of cooling systems. Optimization of the energy consumption of the cooling system in electric refrigerators; Energiforbrug i koelesystemer. Optimering af energiforbruget i koelesystemer i eldrevne koeleskabe

    Energy Technology Data Exchange (ETDEWEB)

    Danig, P.O. [Danmarks Tekniske Universitet (Denmark); Pedersen, J.K.; Ritchie, E. [Aalborg Universitet (Denmark); Kierkegaard, P. [CETEC E/F (Denmark)

    1997-12-31

    The aim of the project was to determine an energy optimum solution for household refrigerators comprising the whole system from electric power supply to the cooled food. The basic idea was to replace the normal ON/OFF control with continuous operation, but so that the engine`s speed of rotation and thereby the performance of the compressor should be controlled according to the cooling demand. A 325 l Gram refrigerator model KS350 was used in the experiments and as a reference. In conventional operation - with a 3,13 cm{sup 3} compressor using ON/OFF control - this refrigerator on average used 33 W at the ISO point (ISO 7371 standard). The most important technical results are that continuous operation of refrigerators uses substantial less energy than ON/OFF control, and that this mode of operation improves the quality of the stored food. A compressor which is small enough to even a refrigerator of the size of 325 l does not exist on the market. A new compressor type must therefore be developed which must by combined and optimized with a pinion. A new compressor type with pinion will, when developed, demand substantial production changes at costs of probably a three-figure million amount. There is no doubt that the continuous operation of refrigerators will become dominating in the future, and globally it will result in a decrease of the energy consumption of 2-3%. (LN)

  16. Task 2 Report - A GIS-Based Technical Potential Assessment of Domestic Energy Resources for Electricity Generation.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nathan [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Grue, Nicholas W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rosenlieb, Evan [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2018-03-14

    The purpose of this report is to support the Lao Ministry of Energy and Mines in assessing the technical potential of domestic energy resources for utility scale electricity generation in the Lao PDR. Specifically, this work provides assessments of technical potential, and associated maps of developable areas, for energy technologies of interest. This report details the methodology, assumptions, and datasets employed in this analysis to provide a transparent, replicable process for future analyses. The methodology and results presented are intended to be a fundamental input to subsequent decision making and energy planning-related analyses. This work concentrates on domestic energy resources for utility-scale electricity generation and considers solar photovoltaic, wind, biomass, and coal resources. This work does not consider potentially imported energy resources (e.g., natural gas) or domestic energy resources that are not present in sufficient quantity for utility-scale generation (e.g., geothermal resources). A technical potential assessment of hydropower resources is currently not feasible due to the absence of required data including site-level assessments of multiple characteristics (e.g., geology environment and access) as well as spatial data on estimated non-exploited hydropower resources. This report is the second output of the Energy Alternatives Study for the Lao PDR, a collaboration led by the Lao Ministry of Energy and Mines and the United States Agency for International Development under the auspices of the Smart Infrastructure for the Mekong program. The Energy Alternatives Study is composed of five successive tasks that collectively support the project's goals. This work is focused on Task 2 - Assess technical potential of domestic energy resources for electricity generation. The work was carried out by a team from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) in collaboration with the Lao Ministry of Energy

  17. Nuclear heat sources for cryogenic refrigerator applications

    International Nuclear Information System (INIS)

    Raab, B.; Schock, A.; King, W.G.; Kline, T.; Russo, F.A.

    1975-01-01

    Spacecraft cryogenic refrigerators require thermal inputs on the order of 1000 W. First, the characteristics of solar-electric and radioisotope heat source systems for supplying this thermal input are compared. Then the design of a 238 Pu heat source for this application is described, and equipment for shipping and handling the heat source is discussed. (LCL)

  18. 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.

  19. Superconducting tunnel-junction refrigerator

    International Nuclear Information System (INIS)

    Melton, R.G.; Paterson, J.L.; Kaplan, S.B.

    1980-01-01

    The dc current through an S 1 -S 2 tunnel junction, with Δ 2 greater than Δ 1 , when biased with eV 1 +Δ 2 , will lower the energy in S 1 . This energy reduction will be shared by the phonons and electrons. This device is shown to be analogous to a thermoelectric refrigerator with an effective Peltier coefficient π* approx. Δ 1 /e. Tunneling calculations yield the cooling power P/sub c/, the electrical power P/sub e/ supplied by the bias supply, and the cooling efficiency eta=P/sub c//P/sub e/. The maximum cooling power is obtained for eV= +- (Δ 2 -Δ 1 ) and t 1 =T 1 /T/sub c/1 approx. 0.9. Estimates are made of the temperature difference T 2 -T 1 achievable in Al-Pb and Sn-Pb junctions with an Al 2 O 3 tunneling barrier. The performance of this device is shown to yield a maximum cooling efficiency eta approx. = Δ 1 /(Δ 2 -Δ 1 ) which can be compared with that available in an ideal Carnot refrigerator of eta=T 1 /(T 2 -T 1 ). The development of a useful tunnel-junction refrigerator requires a tunneling barrier with an effective thermal conductance per unit area several orders of magnitude less than that provided by the A1 2 O 3 barrier in the Al-Pb and Sn-Pb systems

  20. Application of Cascade Refrigeration System with Mixing Refrigerant in Cold Air Cutting

    Science.gov (United States)

    Yang, Y.; Tong, M. W.; Yang, G.; Wang, X. P.

    In the mechanical cutting process, the replacement of traditional cutting solution with cold air can avoid the pollution of environment. In order to high efficient the refrigerating device and flexible adjust the temperature of cold air, it is necessary to use cascade refrigeration system to supply cool quantity for the compressed air. The introduction of a two-component non-azeotropic mixing refrigerant into the cryogenic part of the cascade system, can effectively solve the problems of the system working at too high pressure and the volume expanding of refrigerant in case of the cascade refrigeration sets closed down. However, the filling ratio of mixing refrigerants impact on the relationships among the closing down pressure, refrigerating output and refrigerating efficiency. On the basis of computing and experiment, the optimal mixing ratio of refrigerant R22/R13 and a low temperature of -60° were obtained in this study. A cold air injecting device possessing high efficiency in energy saving has also been designed and manufactured. The cold air, generated from this cascade system and employed in a cutting process, takes good comprehensive effects on machining and cutting.

  1. Trends in the choice of refrigerants according to the applications; Tendances dans le choix des frigorigenes selon les applications

    Energy Technology Data Exchange (ETDEWEB)

    Billiard, F.

    2002-07-01

    No general rules exist in the choice of refrigerants but five classical criteria: thermo-physical, technological, economical, safety, environmental, some regulations and local standards, and the 'cultural' criteria linked with the professional habits and with the personnel training. The best approach to present the evolutions and trends in this domain consists in reasoning application by application. In this document, 8 applications are analyzed: domestic, commercial, and industrial refrigeration, terrestrial and maritime refrigerating transport, air conditioning and heat pumps, air conditioning with water cooling groups, and mobile air conditioning. For each application, national and worldwide statistical data are given which allow to characterize the economical importance of the sector of application and the trends in the choice of refrigerants (HFC, ammonia, hydrocarbons, CO{sub 2} etc..). Finally, some future trends are briefly evoked. (J.S.)

  2. Functional Dependence of Thermodynamic and Thermokinetic Parameters of Refrigerants Used in Mine Air Refrigerators. Part 1 - Refrigerant R407C

    Science.gov (United States)

    Nowak, Bernard; Życzkowski, Piotr; Łuczak, Rafał

    2017-03-01

    The authors of this article dealt with the issue of modeling the thermodynamic and thermokinetic properties (parameters) of refrigerants. The knowledge of these parameters is essential to design refrigeration equipment, to perform their energy efficiency analysis, or to compare the efficiency of air refrigerators using different refrigerants. One of the refrigerants used in mine air compression refrigerators is R407C. For this refrigerant, 23 dependencies were developed, determining its thermodynamic and thermokinetic parameters in the states of saturated liquid, dry saturated vapour, superheated vapor, subcooled liquid, and in the two-phase region. The created formulas have been presented in Tables 2, 5, 8, 10 and 12, respectively. It should be noted that the scope of application of these formulas is wider than the range of changes of that refrigerant during the normal operation of mine refrigeration equipment. The article ends with the statistical verification of the developed dependencies. For this purpose, for each model correlation coefficients and coefficients of determination were calculated, as well as absolute and relative deviations between the given values from the program REFPROP 7 (Lemmon et al., 2002) and the calculated ones. The results of these calculations have been contained in Tables 14 and 15.

  3. 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.

  4. Penjadwalan Perencanaan Produksi Produk Mixed Model Pada Refrigerator Business Unit Di Perusahaan Elektronik Jakarta

    OpenAIRE

    Rinaldi, Dendi

    2011-01-01

    Perusahaan elektronik di Jakarta merupakan salah satu perusahaan yang memiliki enam business unit yaitu Refrigerator, Audio, Electric Fan, Air Conditioner, Water Pump, dan Loundry System. Dalam menjalankan produksi khususnya pada Refrigerator Business Unit, perusahaan mengalami permasalahan pada penjadwalan produksinya karena terdapat 30 model yang diproduksi sesuai permintaan menyebabkan perusahaan sulit untuk melakukan penjadwalan. Salah satu penjadwalan yang dipakai dalam sistem produks...

  5. Refrigeration and global warming

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    Some aspects of global warming in general, and the implications for refrigerants and refrigerator efficiency in particular, are briefly considered in a question and answer format. The concepts of Global Warming Potential (GWP) and Total Equivalent Warming Impact (TEWI) are explained. GWP is an index which allows a simple comparison to be make between the warming effects of different gases on a kg to kg basis relative to carbon. The GWP depends both on the lifetime of a substance in the atmosphere and its infra-red absorption capacity. The overall warming effect of operating a refrigeration system for its entire life is measured by its TEWI. Chloroflourocarbons (CFCs) which have been widely used as refrigerants are powerful greenhouse gases with high GWPs. Because of the bank of CFCs in refrigerating systems, their levels in the atmosphere are still increasing and it will be some time before refrigerant changes will be effective in reducing the warming effects of refrigerant releases. Hydrocarbons, hydroflourocarbons and ammonia all have a part to play as substitute refrigerants. Refrigerator efficiency is very important in terms of reducing CO 2 emissions. (UK)

  6. The control system of the ecological hybrid two stages refrigerating cycle

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2016-01-01

    Full Text Available The compression anticlockwise cycle is mostly used for refrigeration. However due to the environmental regulations, the use of classic refrigerants: F-gases is limited by international agreements. Therefore the combined compression-adsorption hybrid cycle with natural liquids: water/carbon dioxide working as the energy carriers is a promising solution. This allows to utilize the solar or waste energy for the refrigeration purpose. In this paper application of the solar collectors as the energy source for the adsorption cycle, coupled with the low temperature (LT refrigerating carbon dioxide compression cycle is shown. The control of the system is an essential issue to reduce the electric power consumption. The control of the solar heat supply and water sprayed cooling tower, for the adsorption cycle re-cooling, is presented in this paper. The designed control system and algorithm is related to the LT compression cycle, which operates according to the need of cold for the refrigeration chamber. The results of the laboratory investigations of the full system, showing the reduction of the energy consumption and maximum utilization of the solar heat for different control methods are presented.

  7. Vibration-induced electrical noise in a cryogen-free dilution refrigerator: Characterization, mitigation, and impact on qubit coherence

    Energy Technology Data Exchange (ETDEWEB)

    Kalra, Rachpon; Laucht, Arne; Dehollain, Juan Pablo; Bar, Daniel; Freer, Solomon; Simmons, Stephanie; Muhonen, Juha T.; Morello, Andrea, E-mail: a.morello@unsw.edu.au [Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney NSW 2052 (Australia)

    2016-07-15

    Cryogen-free low-temperature setups are becoming more prominent in experimental science due to their convenience and reliability, and concern about the increasing scarcity of helium as a natural resource. Despite not having any moving parts at the cold end, pulse tube cryocoolers introduce vibrations that can be detrimental to the experiments. We characterize the coupling of these vibrations to the electrical signal observed on cables installed in a cryogen-free dilution refrigerator. The dominant electrical noise is in the 5–10 kHz range and its magnitude is found to be strongly temperature dependent. We test the performance of different cables designed to diagnose and tackle the noise, and find triboelectrics to be the dominant mechanism coupling the vibrations to the electrical signal. Flattening a semi-rigid cable or jacketing a flexible cable in order to restrict movement within the cable, successfully reduces the noise level by over an order of magnitude. Furthermore, we characterize the effect of the pulse tube vibrations on an electron spin qubit device in this setup. Coherence measurements are used to map out the spectrum of the noise experienced by the qubit, revealing spectral components matching the spectral signature of the pulse tube.

  8. The performance of the first Jordan Badia's solar powered refrigerator

    International Nuclear Information System (INIS)

    Mohammed Awwad Al-Dabbas

    2012-01-01

    We are facing a significant challenge in Jordan's Badia region. Such challenge present us given that it will be environmentally protected with easy access to the refrigeration process to food and medical vaccines keeping at a reasonably and economical low cost. Solar cooling method that is generated from the sun as a substitute for batteries or electrical power is characteristic of its kind to store a power system for continued use. A pilot project of solar refrigerator was tested to collect technological data on a standard basis so the method control tests are accurate and precise. Solar refrigerator does not require electricity, which utilizes a combination of heat conduction and convection. In addition, it can be made from readily available material such as cardboard, sand, and recycled metal. It is constructed from two cylinders: an inner metal cylinder, fitted inside, and an outer cylinder that can be made of wood or plastic, etc, and organic material such as (sand, wool, or soil) placed in the left space between the two cylinders which is then saturated with water. As heat from the sun evaporates the water, the inner chamber is cooled to reduce and maintains the temperature at (6 degree C). (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    Cavestri, R.C. [Imagination Resources, Inc., Dublin, OH (United States)

    1997-07-01

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

  10. Cryogenic forced convection refrigerating system

    International Nuclear Information System (INIS)

    Klee, D.J.

    1988-01-01

    This patent describes the method of refrigerating products by contact with a refrigerating gas which comprises introducing product into a refrigeration zone, contacting the product with the refrigerating gas for a sufficient time to refrigerate it to the appropriate extent and removing the refrigerated product. The improvement for producing the refrigeration gas from a liquid cryogen such that essentially all of the liquid cryogen is fully vaporized before contacting the product comprises: (a) introducing the liquid cryogen, selected from the group consisting of liquid air and liquid nitrogen, at elevated pressure into an ejector as the motive fluid to accelerate a portion of a warm refrigerating gas through the ejector while mixing the cryogen and gas to effect complete vaporization of the liquid cryogen and substantial cooling of the portion of the refrigerating gas resulting in a cold discharge gas which is above the liquefaction temperature of the cryogen; (b) introducing the cold discharge gas into a forced circulation pathway of refrigerating gas and producing a cold refrigerating gas which contacts and refrigerates product and is then at least partially recirculated; (c) sensing the temperature of the refrigerating gas in the forced circulation pathway and controlling the introduction of liquid cryogen with regard to the sensed temperature to maintain the temperature of the discharge gas above the liquefacton temperature of the cryogen utilized

  11. Air-Conditioning for Electric Vehicles

    Science.gov (United States)

    Popinski, Z.

    1984-01-01

    Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

  12. Relationship between composition of mixture charged and that in circulation in an auto refrigerant cascade and a J-T refrigerator operating in liquid refrigerant supply mode

    Science.gov (United States)

    Sreenivas, Bura; Nayak, H. Gurudath; Venkatarathnam, G.

    2017-01-01

    The composition of the refrigerant mixture in circulation during steady state operation of J-T and allied refrigerators is not the same as that charged due to liquid hold up in the heat exchangers and phase separators, as well as the differential solubility of different refrigerant components in the compressor lubricating oil. The performance of refrigerators/liquefiers operating on mixed refrigerant cycles is dependent on the mixture composition. It is therefore important to charge the right mixture that results in an optimum composition in circulation during steady state operation. The relationship between the charged and circulating composition has been experimentally studied in a J-T refrigerator operating in the liquid refrigerant supply (LRS) mode and an auto refrigerant cascade refrigerator (with a phase separator) operating in the gas refrigerant supply (GRS) mode. The results of the study are presented in this work. The results show that the method presented earlier for J-T refrigerators operating in GRS mode is also applicable in the case of refrigerators studied in this work.

  13. Flammable refrigerants

    NARCIS (Netherlands)

    Gerwen, R.J.M. van; Verwoerd, M.; Oostendorp, P.A.

    1999-01-01

    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

  14. Performance of refrigerating machineries with new refrigerants; Performance des machines frigorifiques avec les nouveaux refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Bailly, A; Jurkowski, R [CIAT, 01 - Culoz (France)

    1998-12-31

    This paper reports on a comparative study of the thermal performances of different refrigerants like R-22, R-134a, R-404A and R-407C when used as possible substitutes for the HCFC22 refrigerant in a given refrigerating machinery equipped with compact high performance plate exchangers. Thermal performances are compared in identical operating conditions. The behaviour of the two-phase exchange coefficient is analyzed with respect to the different parameters. The composition of the mixture after one year of operation has been analyzed too and the influence of oil on the performances is studied. (J.S.)

  15. Performance of refrigerating machineries with new refrigerants; Performance des machines frigorifiques avec les nouveaux refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Bailly, A.; Jurkowski, R. [CIAT, 01 - Culoz (France)

    1997-12-31

    This paper reports on a comparative study of the thermal performances of different refrigerants like R-22, R-134a, R-404A and R-407C when used as possible substitutes for the HCFC22 refrigerant in a given refrigerating machinery equipped with compact high performance plate exchangers. Thermal performances are compared in identical operating conditions. The behaviour of the two-phase exchange coefficient is analyzed with respect to the different parameters. The composition of the mixture after one year of operation has been analyzed too and the influence of oil on the performances is studied. (J.S.)

  16. Behavior of FFC refrigerants in the presence of refrigerant oils. Oelverhalten chlorfreier Kaeltemittel

    Energy Technology Data Exchange (ETDEWEB)

    Burke, M.; Kruse, H. (Hannover Univ. (Germany, F.R.). Inst. fuer Kaeltetechnik und Angewandte Waermetechnik)

    1990-01-01

    Looking for substitutes for the ozone-depleting refrigerants R12 and R22, investigations were made of the miscibility of FFC refrigerants (R23 - trifluoromethane CHF{sub 3}, R134a - tetrafluoroethane CH{sub 3}-CHF{sub 2}, and R152a - difluoroethane CH{sub 3}-CHF{sub 2}) with refrigerator oils. First experimental results reveal the refrigerants' behavior when mixed with mineral oils, alkylbenzene, PAG and ester-based oils. Mixtures of above refrigerants, especially R134a/R152a and R23/R152a as binary nonazeotropic mixtures, are considered conceivable substitutes. While addition of R23 reduces the mixture's flammability, addition of R152a improves the solubility of R134a in refrigerant oils. (orig./HW).

  17. Artificial neural network analysis of triple effect absorption refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Hajizadeh Aghdam, A. [Department of Mechanical Engineering, Islamic Azad University (Iran, Islamic Republic of)], email: a.hajizadeh@iaukashan.ac.ir; Nazmara, H.; Farzaneh, B. [Department of Mechanical Engineering, University of Tabriz (Iran, Islamic Republic of)], email: h.nazmara@nioec.org, email: b_farzaneh_ms@yahoo.com

    2011-07-01

    In this study, artificial neural networks are utilized to predict the performance of triple effect series and parallel flow absorption refrigeration systems, with lithium bromide/water as the working fluid. Important parameters such as high generator and evaporator temperatures were varied and their effects on the performance characteristics of the refrigeration unit were observed. Absorption refrigeration systems make energy savings possible because they can use heat energy to produce cooling, in place of the electricity used for conventional vapour compression chillers. In addition, non-conventional sources of energy (such as solar, waste heat, and geothermal) can be utilized as their primary energy input. Moreover, absorption units use environmentally friendly working fluid pairs instead of CFCs and HCFCs, which affect the ozone layer. Triple effect absorption cycles were analysed. Results apply for both series and parallel flow systems. A relative preference for parallel-flow over series-flow is also shown.

  18. The Influence of Stunning Method, Refrigeration and Freezing Time on the Rheological and Textural Properties of Raw Meat

    Directory of Open Access Journals (Sweden)

    Liliana Tudoreanu

    2013-11-01

    Full Text Available The present research was conducted to provide information on the influence of stunning methods in conjunction with refrigeration and freezing time on the textural and rheological properties of raw meat. Pork raw meat, commercially available, was analyzed for textural properties such as hardness, cohesiveness, adhesiveness and fracture force. Sample were analyzed fresh, after 3 days of refrigeration, and 15 days, 30days and 60 days freezing time in commercially available refrigerators mimicking the storing conditions used by consumers. For pork raw meat, hardness increased sharply after 3 days of refrigeration and showed no significant differences after 15days of freezing compared to 3days refrigeration time. After 30 days of freezing the raw pork meat samples’ hardness decreased significantly compared to the hardness of the samples freeze for15 days. Hardness of gas stunning raw pork meat samples compared to electrical stunning raw pork meat samples was 2.57 times higher indicating a better firmness of the gas stunning raw pork meat. The cohesiveness of the raw pork meat from gas stunned animals maintained its levels after 60 days of freezing while the meat from electrically stunned animals showed significant modificatio

  19. Prediction of Dangerous Time in Case Hydrocarbon Refrigerant Leaks into Household Refrigerator Cabinet

    Science.gov (United States)

    Meguro, Takatoshi; Kaji, Nobufuji; Miyake, Kunihiro

    Hydrocarbon refrigerators are now on sale in European countries. However, hydrocarbons are flammable. A common claim is that concentration of hydrocarbon in the refrigerator could exceed the lower explosive limit by a sudden leak and then a spark ignites a flame causing overpressure. There is the need of the studies on potential risks originated from the use of flammable refrigerants. Thus, the flow rate of the fresh air into the refrigerator cabinet has been defined experimentally, and the spatial average concentration in the refrigerator cabinet has been analyzed theoretically to predict the dangerous time in excess of the lower explosive limit.

  20. Theoretical study on a novel dual-nozzle ejector enhanced refrigeration cycle for household refrigerator-freezers

    International Nuclear Information System (INIS)

    Zhou, Mengliu; Wang, Xiao; Yu, Jianlin

    2013-01-01

    Highlights: • A novel dual-nozzle ejector enhanced refrigeration cycle is proposed. • The novel cycle is evaluated by using the developed mathematical model. • The results show the performances of the novel cycle could be significantly improved. • The novel cycle shows its promise in household refrigerator-freezers applications. - Abstract: In this study, a novel dual-nozzle ejector enhanced refrigeration cycle is presented for dual evaporator household refrigerator-freezers. The proposed ejector equipped with two nozzles can efficiently recover the expansion work from cycle throttling processes and enhance cycle performances. The performances of the novel cycle are evaluated by using the developed mathematical model, and then compared with that of the conventional ejector enhanced refrigeration cycle and basic vapor-compression refrigeration cycle. The simulation results show that for the given operating conditions, the coefficient of performance (COP) of the novel cycle using refrigerant R134a is improved by 22.9–50.8% compared with that of the basic vapor-compression refrigeration cycle, and the COP improvement is 10.5–30.8% larger than that of the conventional ejector enhanced refrigeration cycle. The further simulation results of the novel cycle using refrigerant R600a indicate that the cycle COP and volumetric refrigeration capacity could be significantly improved

  1. Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

    International Nuclear Information System (INIS)

    Wang, L.; Chen, G.M.; Wang, Q.; Zhong, M.

    2007-01-01

    In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide-water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated

  2. Developments in magnetocaloric refrigeration

    International Nuclear Information System (INIS)

    Brueck, Ekkes

    2005-01-01

    Modern society relies on readily available refrigeration. Magnetic refrigeration has three prominent advantages compared with compressor-based refrigeration. First, there are no harmful gases involved; second, it may be built more compactly as the working material is a solid; and third, magnetic refrigerators generate much less noise. Recently a new class of magnetic refrigerant-materials for room-temperature applications was discovered. These new materials have important advantages over existing magnetic coolants: they exhibit a large magnetocaloric effect (MCE) in conjunction with a magnetic phase-transition of first order. This MCE is larger than that of Gd metal, which is used in the demonstration refrigerators built to explore the potential of this evolving technology. In the present review we compare the different materials considering both scientific aspects and industrial applicability. Because fundamental aspects of MCE are not so widely discussed, we also give some theoretical considerations. (topical review)

  3. Energy performance of supermarket refrigeration and air conditioning integrated systems working with natural refrigerants

    International Nuclear Information System (INIS)

    Cecchinato, Luca; Corradi, Marco; Minetto, Silvia

    2012-01-01

    The current trends in commercial refrigeration aim at reducing the synthetic refrigerant charge, either by minimising the internal volume of the circuit or by utilising natural refrigerants, and at energy saving. The energy efficiency of supermarkets can be improved by optimising components design, recovering thermal and refrigerating energy, adopting innovative technology solutions, integrating the HVAC system with medium temperature and low temperature refrigeration plants and, finally, reducing thermal loads on refrigerated cases. This study aims at investigating the performance of different lay-out and technological solutions where only natural refrigerants are used and at finding the potential for improving energy efficiency over the traditional systems in different climates. In the analysis, chillers and heat pumps working with ammonia or propane, medium temperature systems working with ammonia or propane and carbon dioxide as heat transfer fluid or with carbon dioxide as the refrigerant and low temperature systems working with carbon dioxide are considered and benchmarked with a state-of-the-art HFCs based plant. The most efficient investigated solution enables an annual energy saving higher than 15% with respect to the baseline solution for all the considered climates. - Highlights: ► Different natural refrigerants supermarket HVAC and R integrated systems are analysed. ► Some of the proposed solutions offer a significant benefit over the baseline one. ► Up to 18.7% energy saving is achieved in the considered climates. ► The refrigeration unit condensation by the AC chiller offers the poorest results.

  4. The Impact of Minimum Energy Performance Standards (MEPS) Regulation on Electricity Saving in Malaysia

    Science.gov (United States)

    Fatihah Salleh, Siti; Eqwan Roslan, Mohd; Isa, Aishah Mohd; Faizal Basri Nair, Mohd; Syafiqah Salleh, Siti

    2018-03-01

    One of Malaysia’s key strategies to promote efficient energy use in the country is to implement the minimum energy performance standards (MEPS) through the Electricity Regulations (Amendment) 2013. Five selected electrical appliances (refrigerator, air conditioner, television, domestic fans and lamp fittings) must comply with MEPS requirement in order to be sold in Malaysian market. Manufacturers, importers or distributors are issued Certificate of Approval (COA) if products are MEPS-compliant. In 2015, 1,215 COAs were issued but the number of MEPS products in the market is unknown. This work collects sales data from major manufacturers to estimate the annual sales of MEPS appliances and the cumulative electricity consumption and electricity saving. It was found that most products sold have 3-star rating and above. By year 2015, total cumulative electricity savings gained from MEPS implementation is 3,645 GWh, with air conditioner being the highest contributor (30%). In the future, it is recommended that more MEPS products and related incentives be introduced to further improve efficiency of energy use in Malaysia.

  5. COP improvement of refrigerator/freezers, air-conditioners, and heat pumps using nonazeotropic refrigerant mixtures

    Science.gov (United States)

    Westra, Douglas G.

    1993-01-01

    With the February, 1992 announcement by President Bush to move the deadline for outlawing CFC (chloro-fluoro-carbon) refrigerants from the year 2000 to the year 1996, the refrigeration and air-conditioning industries have been accelerating their efforts to find alternative refrigerants. Many of the alternative refrigerants being evaluated require synthetic lubricants, are less efficient, and have toxicity problems. One option to developing new, alternative refrigerants is to combine existing non-CFC refrigerants to form a nonazeotropic mixture, with the concentration optimized for the given application so that system COP (Coefficient Of Performance) may be maintained or even improved. This paper will discuss the dilemma that industry is facing regarding CFC phase-out and the problems associated with CFC alternatives presently under development. A definition of nonazeotropic mixtures will be provided, and the characteristics and COP benefits of nonazeotropic refrigerant mixtures will be explained using thermodynamic principles. Limitations and disadvantages of nonazeotropic mixtures will be discussed, and example systems using such mixtures will be reviewed.

  6. Fermilab tevatron five refrigerator system tests

    International Nuclear Information System (INIS)

    Rode, C.; Ferry, R.; Leiniger, M.; Makara, J.; Misek, J.; Mizicko, D.; Richied, D.; Theilacker, J.

    1982-01-01

    The Fermilab Tevatron refrigeration system is described with the layout illustrated. The compressor control loops, the refrigerator control loops, and magnet control loops (two per refrigerator) are described and each illustrated. The mobile purifier is described. A five refrigerator test is presented, using two compressor buildings, satellite refrigerator concept test and the test current to the writing. The configuration of the five refrigerator test is diagramed

  7. The Impact of Socio-Economic Indicators on Sustainable Consumption of Domestic Electricity in Lithuania

    Directory of Open Access Journals (Sweden)

    Sergej Vojtovic

    2018-01-01

    Full Text Available Lithuania is one of the EU Member States, where the rate of energy consumption is comparatively low but consumption of electricity has been gradually increasing over the last few years. Despite this trend, households in only three EU Member States consume less electricity than Lithuanian households. The purpose of this research is to analyse the impact of socio-economic factors on the domestic electricity consumption in Lithuania, i.e., to establish whether electricity consumption is determined by socio-economic conditions or population’s awareness to save energy. Cointegration analysis, causality test and error-correction model were used for the analysis. The results reveal that there is a long run equilibrium relationship between residential electricity consumption per capita and GDP at current prices as well as the ratio of the registered unemployed to the working-age population. In consequence, the results of the research propose that improvement of living standards for Lithuanian community calls for the necessity to pay particular attention to the promotion of sustainable electricity consumption by providing consumers with appropriate information and feedback in order to seek new energy-related consumption practices.

  8. 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.

  9. Energy engineering. Standardization in the domain of coldness production; Genie energetique. Normalisation dans le domaine du froid

    Energy Technology Data Exchange (ETDEWEB)

    Legent, N. [Association Francaise de Normalisation (AFNOR), 92 - Paris-la-Defense (France)

    2000-10-01

    This paper deals with the recent advances in the domain of standardization and regulation of refrigeration and cold production systems used in the industry and in the commercial sector: 1 - international standardization; 2 - European standardization; 3 - international standardization in the domain of cold production (ISO/TC 86 'coldness and air conditioning', CEI 61C 'domestic refrigerating appliances', CEI 61D 'air-conditioning appliances for domestic and similar use', ISO/TC 104 'goods transportation containers'); 4 - European standardization in the domain of cold production (CEN/TC 182 'refrigerating systems - safety and environment requirements', CEN/TC 44 'household refrigerating appliances and refrigerating furniture for stores', CEN/TC 113 'heat pumps and air-conditioners', CEN/TC 141 'manometers and thermometers, measuring and recording means', CENELEC 61 'safety of domestic electrical appliances'); 5 - French standardization (international file, European file, French file, French standardization system); 6 - national standardization in other countries; 7 - regulations in the domain of cold production. (J.S.)

  10. 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.

  11. 'TEWI' concept for estimation of the global warming from the refrigerating and air conditioning systems

    International Nuclear Information System (INIS)

    Ciconkov, Risto

    2002-01-01

    The most applied CFC refrigerants and their HFC alternatives. values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) of the most used refrigerants. natural working fluids and their properties. Montreal Protocol and Kyoto Protocol, illogical relations between them concerning to the HFC fluids. Confusion and polemics on the international level about the appliance of HFCs which, by the Kyoto Protocol, are liable to reduction. Introduction of the TEWI concept as a method for estimating the overall influence of refrigerating and air conditioning systems on the greenhouse effect: the direct emission (refrigerant leakage in the atmosphere) and indirect emission as a result of the electrical energy consumption. A demonstration of the TEWI concept on the concrete example in several variants. A discussion about the appliance of the TEWI concept. Meaning of the energy efficiency of the refrigerating systems (indirect CO 2 emission). One of the main measures: prevention of refrigerant leakage (direct CO 2 emission). A need of permanent education and training courses of the people who work on refrigerating and air conditioning systems. A necessity for constitution of an expert body in the country, preparation of a strategy to lay obligations on the new changes of the Kyoto Protocol and news on the world market. Introduction of country regulations, certification of the companies and people involved in refrigeration and air conditioning. (Author)

  12. Magnon-driven quantum dot refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yuan; Huang, Chuankun; Liao, Tianjun; Chen, Jincan, E-mail: jcchen@xmu.edu.cn

    2015-12-18

    Highlights: • A three-terminal quantum dot refrigerator is proposed. • The effects of magnetic field, applied voltage, and polarization are considered. • The region that the system can work as a refrigerator is determined. • Two different magnon-driven quantum dot refrigerators are compared. - Abstract: A new model of refrigerator consisting of a spin-splitting quantum dot coupled with two ferromagnetic reservoirs and a ferromagnetic insulator is proposed. The rate equation is used to calculate the occupation probabilities of the quantum dot. The expressions of the electron and magnon currents are obtained. The region that the system can work in as a refrigerator is determined. The cooling power and coefficient of performance (COP) of the refrigerator are derived. The influences of the magnetic field, applied voltage, and polarization of two leads on the performance are discussed. The performances of two different magnon-driven quantum dot refrigerators are compared.

  13. Refrigerator efficiency in Ghana: Tailoring an appliance market transformation program design for Africa

    International Nuclear Information System (INIS)

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

    2007-01-01

    In some cases, a simple replication of developed country appliance efficiency labels and standards may not be completely feasible in Ghana, Africa. Yet by creatively modifying the developed country appliance efficiency market transformation model, it should be possible to achieve dramatic energy use reductions. As was true in developed countries in the previous two decades, refrigeration efficiency improvements provide the greatest energy savings potential in the residential electricity sector in Ghana. Although Ghana, like many African countries may impose standards on imports since Ghana does not have manufacturing facilities for appliances in country. This approach may hurt some consumers who patronize a very diverse market of used appliances imported from Europe. We discuss how meeting the challenges of the Ghanaian market will require modification of the usual energy efficiency labeling and standards paradigm. But once a refrigerator market transformation is accomplished in Ghana, we estimate an average energy savings potential of 550 kWh/refrigerator/year, and a monetary savings of more than $35/refrigerator/year. We discuss how this modified refrigerator efficiency market transformation may occur in the Ghanaian context. If successful, this market transformation is likely to be an example for many other African countries

  14. Applicability of ASST-A helium refrigeration system for JLab End Station Refrigerator

    Science.gov (United States)

    Hasan, N.; Knudsen, P.; Ganni, V.

    2017-12-01

    The MØLLER experiment at Jefferson Lab (JLab) is a high power (5 kW) liquid hydrogen target scheduled to be operational in the 12 GeV-era. At present, cryogenic loads and targets at three of JLab’s four experimental halls are supported by the End Station Refrigerator (ESR) - a CTI/Helix 1.5 kW 4.5 K refrigerator. It is not capable of supporting the high power target load and a capacity upgrade of the ESR cryogenic system is essential. The ASST-A helium refrigeration system is a 4 kW 4.5 K refrigerator. It was designed and used for the Superconducting Super Collider Lab (SSCL) magnet string test and later obtained by JLab after the cancellation of that project. The modified ASST-A refrigeration system, which will be called ESR-II along with a support flow from JLab’s Central Helium Liquefier (CHL) is considered as an option for the End Station Refrigerator capacity upgrade. The applicability of this system for ESR-II under varying load conditions is investigated. The present paper outlines the findings of this process study.

  15. Cooling performance and energy saving of a compression-absorption refrigeration system driven by a gas engine

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Z.G.; Guo, K.H. [Sun Yat-Sen University, Guangzhou (China). Engineering School

    2006-07-01

    The prototype of combined vapour compression-absorption refrigeration system was set up, where a gas engine drove directly an open screw compressor in a vapour compression refrigeration chiller and waste heat from the gas engine was used to operate absorption refrigeration cycle. The experimental procedure and results showed that the combined refrigeration system was feasible. The cooling capacity of the prototype reached about 589 kW at the Chinese rated conditions of air conditioning (the inlet and outlet temperatures of chilled water are 12 and 7{sup o}C, the inlet and outlet temperatures of cooling water are 30 and 35{sup o}C, respectively). Primary energy rate (PER) and comparative primary energy saving were used to evaluate energy utilization efficiency of the combined refrigeration system. The calculated results showed that the PER of the prototype was about 1.81 and the prototype saved more than 25% of primary energy compared to a conventional electrically driven vapour compression refrigeration unit. Error analysis showed that the total error of the combined cooling system measurement was about 4.2% in this work. (author)

  16. First and Second Law Analyses of Trans-critical N2O Refrigeration Cycle Using an Ejector

    Directory of Open Access Journals (Sweden)

    Damoon Aghazadeh Dokandari

    2018-04-01

    Full Text Available An ejector-expansion refrigeration cycle using nitrous oxide was assessed. Thermodynamic analyses, including energy and exergy analyses, were carried out to investigate the effects on performance of several key factors in the system. The results show that the ejector-expansion refrigeration cycle (EERC has a higher maximum coefficient of performance and exergy efficiency than the internal heat exchanger cycle (IHEC, by 12% and 15%, respectively. The maximum coefficient of performance and exergy efficiency are 14% and 16.5% higher than the corresponding values for the vapor-compression refrigeration cycle (VCRC, respectively. The total exergy destruction for the N2O ejector-expansion cycle is 63% and 53% less than for IHEC and VCRC, respectively. Furthermore, the highest COPs for the vapor-compression refrigeration, the internal heat exchanger and the ejector-expansion refrigeration cycles correspond to a high side pressure of 7.3 MPa, and the highest COPs for the three types of CO2 refrigeration cycles correspond to a high side pressure of 8.5 MPa. Consequently, these lead to a lower electrical power consumption by the compressor.

  17. Homecell: design and development of a 2 kW fuel cell based electric energy generating system, for the domestic market

    Energy Technology Data Exchange (ETDEWEB)

    Bordallo, C.R.; Moreno, E.; Brey, J.J.; Garcia, C.; Castro, A.; Sarmiento, B. [Hynergreen Technologies, S.A., Seville (Spain)

    2004-07-01

    'Full text:' Even though fuel cell technology has been known in industry for decades now, it has come to the fore in recent years hand in hand with renewable energy sources and the hydrogen vector, as a clean, reliable and efficient electric energy source. Within the stationary applications of fuel cells, the production of high output electric energy has always stood out and this could range from several hundreds of watts to megawatts to supply large plants. The objective of this project is to develop, construct and experimentally validate an electric energy generating system for domestic applications of up to 2 kW. This is due to the fact that multiple domestic applications currently exist for which an electric output of 2 kW is sufficient. On the other hand, an electricity supply might not exist, or might be deficient; and this system will enable electricity supply even under these circumstances. Moreover, the existing system is very versatile and could be complemented with other hydrogen production ones (using photovoltaic energy for example), or else two systems could be used in parallel if outputs up to 4 kW were required, and other applications in other markets, such as telecommunications or tele-metering systems, could be undertaken. (author)

  18. 78 FR 4383 - Foreign-Trade Zone 117-Orange, Texas; Notification of Proposed Production Activity; Signal...

    Science.gov (United States)

    2013-01-22

    .... On its domestic sales, Signal would be able to choose the duty rate during customs entry procedures... related parts, compressors, turbochargers, refrigeration/cooling equipment, electric motors, generators...

  19. Investigation of the effect of different refrigerants on performances of binary geothermal power plants

    International Nuclear Information System (INIS)

    Basaran, Anil; Ozgener, Leyla

    2013-01-01

    Highlights: • Working fluid selection plays a key role on binary cycle performance. • Selected refrigerants were analyzed in the sample cycle under the same working conditions. • Energy and exergy efficiencies of binary cycle were calculated for 8 refrigerants. - Abstract: The paper tries to review the argument of the use of working fluids for binary cycle power plants and has been dedicated to this specific argument with a more general perspective. Binary cycle that allows the production of electricity from geothermal energy sources is one of these systems. In this cycle, thermal energy obtained from geothermal sources is transferred to second working fluid. Therefore, selection of second working fluid plays a key role on the cycle performance. In this study, a sample geothermal binary power cycle was modeled and 12 refrigerants that are HFC, HC, and zoetrope refrigerant mixtures were selected as working fluid. Energy and exergy efficiencies of binary cycle were calculated for 12 refrigerants. Dry type fluids of investigated refrigerants R 236ea, R 600, R 600a, and R 227ea showed higher energy and exergy efficiencies, respectively. On the other hand, R 143a, R 415A, R 290, and R 413A that are wet fluids indicated lower energy and exergy efficiencies, respectively

  20. Indoor unit for electric heat pump

    Science.gov (United States)

    Draper, R.; Lackey, R.S.; Fagan, T.J. Jr.; Veyo, S.E.; Humphrey, J.R.

    1984-05-22

    An indoor unit for an electric heat pump is provided in modular form including a refrigeration module, an air mover module, and a resistance heat package module, the refrigeration module including all of the indoor refrigerant circuit components including the compressor in a space adjacent the heat exchanger, the modules being adapted to be connected to air flow communication in several different ways as shown to accommodate placement of the unit in various orientations. 9 figs.

  1. Eco-Friendly Alternative Refrigeration Systems -R-ES-O-N-A-N--CE ...

    Indian Academy of Sciences (India)

    An electrical signal may be converted to acoustical (i.e. ... Thermoacoustic Refrigeration System. In a simple ... Tc and rejecting Wclste heat power Qh to a heat sink at T h. •. In .... use where eco-friendliness, simplicity, reliability or low cost is.

  2. Model Predictive Control for Flexible Power Consumption of Large-Scale Refrigeration Systems

    DEFF Research Database (Denmark)

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

    2014-01-01

    A model predictive control (MPC) scheme is introduced to directly control the electrical power consumption of large-scale refrigeration systems. Deviation from the baseline of the consumption is corresponded to the storing and delivering of thermal energy. By virtue of such correspondence...

  3. Thermodynamic performance of an auto-cascade ejector refrigeration cycle with mixed refrigerant R32 + R236fa

    International Nuclear Information System (INIS)

    Tan, Yingying; Wang, Lin; Liang, Kunfeng

    2015-01-01

    In this paper, an auto-cascade ejector refrigeration cycle (ACERC) is proposed to obtain lower refrigeration temperature based on conventional ejector refrigeration and auto-cascade refrigeration principle. The thermodynamic performance of ACERC is investigated theoretically. The zeotropic refrigerant mixture R32 + R236fa is used as its working fluid. A parametric analysis is conducted to evaluate the effects of some thermodynamic parameters on the cycle performance. The study shows that refrigerant mixture composition, condenser outlet temperature and evaporation pressure have effects on performance of ACERC. The theoretical results also indicate that the ACERC can achieve the lowest refrigeration temperature at the temperature level of −30 °C. The application of zeotropic refrigerant mixture auto-cascade refrigeration in the ejector refrigeration cycle can provide a new way to obtain lower refrigeration temperature utilizing low-grade thermal energy. - Highlights: • An auto-cascade ejector refrigerator with R32 + R236fa mixed refrigerant is proposed. • The cycle can obtain a refrigeration temperature at −30 °C temperature range. • The effects of some thermodynamic parameters on the cycle performance are evaluated

  4. 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

  5. The role of domestic biomass in electricity, heat and grid balancing markets in Switzerland

    International Nuclear Information System (INIS)

    Panos, Evangelos; Kannan, Ramachandran

    2016-01-01

    The Swiss Energy Strategy targets to reduce per capita energy consumption, to decrease the share of fossil energy and to replace nuclear electricity generation by gains in efficiency and renewable energy sources. In view of the above objectives, we evaluated the prospects of biomass in stationary applications and grid balancing from an energy system perspective. We quantify a number of “what-if” scenarios using a cost-optimisation bottom-up model, with detailed representation of biomass production and use pathways, electricity and heat sectors, and grid ancillary services markets. The scenario analysis shows that domestic biomass can contribute 5–7% in electricity and 14–21% in heat production by 2050, depending on natural gas prices and climate policy intensity. Pooling of biogenic driven cogeneration plants can provide about 22–44% of the total secondary control power in 2050. Generally, biogenic technologies complement other assets in heat, electricity and ancillary services markets such as heat pumps, new renewable sources and hydropower. - Highlights: • Development and application of the Swiss TIMES electricity and heat system model. • Bioenergy supplies 5–7% of electricity and 14–21% of heat by 2050. • Biogenic gas driven CHP can provide 22–44% of secondary control power in 2050.

  6. The Effect of Electric Load Profiles on the Performance of Off-Grid Residential Hybrid Renewable Energy Systems

    Directory of Open Access Journals (Sweden)

    Stephen Treado

    2015-10-01

    Full Text Available This paper investigates the energy performance of off-grid residential hybrid renewable electric power systems, particularly the effect of electric load profiles on the ability to harvest available solar energy and avoid the consumption of auxiliary energy in the form of propane. The concepts are illustrated by an analysis of the energy performance of electric and propane-fired refrigerators. Off-grid electric power systems frequently incorporate a renewable source, such as wind or solar photovoltaic (PV, with a back-up power provided by a propane fueled motor/generator. Among other design decisions, residential consumers face the choice of employing an electric refrigerator with a conventional vapor compression refrigeration system, or a fuel-fired refrigerator operating as an absorption refrigeration system. One interesting question is whether it is more advantageous from an energy perspective to use electricity to run the refrigerator, which might be provided by some combination of the PV and propane motor/generator, thereby taking advantage of the relatively higher electric refrigerator Coefficient of Performance (COP and free solar energy but having to accept a low electrical conversion efficiency of the motor/generator, or use thermal energy from the combustion of propane to produce the refrigeration effect via an absorption system, albeit with a much lower COP. The analysis is complicated by the fact that most off-grid renewable electrical power systems utilize a battery bank to provide electrical power when it is not available from the wind turbine or PV system, so the state of charge of the battery bank will have a noticeable impact on what energy source is available at any moment in time. Daily electric load profiles combined with variable solar energy input determine the state of charge of the battery bank, with the degree of synchronization between the two being a critical factor in determining performance. The annual energy usage

  7. 10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

    Science.gov (United States)

    2010-01-01

    ... functional characteristics that affect energy consumption. Commercial refrigerator, freezer, and refrigerator... formed by the plane of the door, when the equipment is viewed in cross-section; and (2) For equipment...

  8. Computer simulation with TRNSYS for a mobile refrigeration system incorporating a phase change thermal storage unit

    International Nuclear Information System (INIS)

    Liu, Ming; Saman, Wasim; Bruno, Frank

    2014-01-01

    Highlights: • A mobile refrigeration system incorporating phase change thermal storage was simulated using TRNSYS. • A TRNSYS component of a phase change thermal storage unit was created and linked to other components from TRNSYS library. • The temperature in the refrigerated space can be predicted using this TRNSYS model under various conditions. • A mobile refrigeration system incorporating PCM and an off-peak electric driven refrigeration unit is feasible. • The phase change material with the lowest melting temperature should be selected. - Abstract: This paper presents a new TRNSYS model of a refrigeration system incorporating phase change material (PCM) for mobile transport. The PCTSU is charged by an off-vehicle refrigeration unit and the PCM provides cooling when discharging and the cooling released is utilized to cool down the refrigerated space. The advantage of this refrigeration system compared to a conventional system is that it consumes less energy and produces significantly lower greenhouse gas emissions. A refrigeration system for a typical refrigerated van is modelled and simulations are performed with climatic data from four different locations. The main components of the TRNSYS model are Type 88 (cooling load estimation) and Type 300 (new PCTSU component), accompanied by other additional components. The results show that in order to maintain the temperature of the products at −18 °C for 10 h, a total of 250 kg and 390 kg of PCM are required for no door opening and 20 door openings during the transportation, respectively. In addition, a parametric study is carried out to evaluate the effects of location, size of the refrigerated space, number of door openings and melting temperature of the PCM on the thermal performance

  9. Electrical production for domestic and industrial applications using hybrid PV-wind system

    International Nuclear Information System (INIS)

    Essalaimeh, S.; Al-Salaymeh, A.; Abdullat, Y.

    2013-01-01

    Highlights: ► Modeling and building hybrid system of PV and wind turbine. ► Investigation of the electrical generation under Amman–Jordan’s climate. ► Configuration of theoretical and actual characteristics of the hybrid system. ► Testing effects of dust, inclination and load on the electrical generation. ► Financial analysis for various applications. - Abstract: The present work shows an experimental investigation of using a combination of solar and wind energies as hybrid system for electrical generation under the Jordanian climate conditions. The generated electricity has been utilized for different types of applications and mainly for space heating and cooling. The system has also integration with grid connection to have more reliable system. Measurements included the solar radiation intensity, the ambient temperature, the wind speed and the output power from the solar PV panels and wind turbine. The performance characteristic of the PV panels has been obtained by varying the load value through a variable resistance. Some major factors have been studied and practically measured; one of them is the dust effect on electrical production efficiency for photovoltaic panels. Another factor is the inclination of the PV panels, where varying the angle of inclination has a seasonal importance for gathering the maximum solar intensity. Through mathematical calculation and the collected and measured data, a simple payback period has been calculated of the hybrid system in order to study the economical aspects of installing such a system under Jordanian climate conditions and for different usages and local tariffs including domestic, industrial and commercial applications. It was found through this work that the generated electricity of hybrid system and under Jordanian climate conditions can be utilized for electrical heating and cooling through split units and resistive heaters.

  10. A low temperature cryostat with a refrigerator for studying electron irradiation effects on solids

    International Nuclear Information System (INIS)

    Oka, Takashi; Yoshida, Toshio; Kitagawa, Michiharu; Yanai, Masayoshi

    1976-01-01

    A low temperature cryostat with a small cryogenic refrigerator is described which is convenient for studying irradiation effects of the energetic electrons on solids. It allows a sample to be kept about 12 K without irradiation and 15 K under the irradiation at a heating rate of 1.5 w. The sample temperature can be changed up to room temperature by adjusting the power of an attached heater and the pressure of a compressor for the refrigerator. The optical and electrical properties of the sample can be measured under and after irradiation. (auth.)

  11. How to use the clean development mechanism in the residential sector? The case of Brazilian refrigerators

    International Nuclear Information System (INIS)

    Khalil, Helioui; Cohen, Claude; Salem Szklo, Alexandre

    2006-01-01

    The definition of simple and reliable emission baselines is crucial to foster clean development mechanism (CDM) projects. This paper assesses a project methodology that could boost large-scale energy-efficiency projects in the sector of domestic appliances. The baseline appliance is defined a priori in a 'conservative' manner as the design option minimizing life-cycle social costs. The project methodology consists in a program which rebates new appliances according to their emission savings compared to the baseline. Is the proposed baseline acceptable? What could be the impact of such project on emissions? To address these questions, we look for insights from a hypothetical case on Brazilian refrigerators. A rational choice model is developed which assumes that households select design options minimizing life-cycle private costs. Results suggest that electricity tariff distortions and financial constraints might hamper project performances and allow significant free-riding. Low income households remain trapped into low-efficiency choices and high income households adopt outperforming appliances, whether rebated or not. However, simple solutions likely to improve the project methodology do exist

  12. Ultimate refrigerating conditions, behavior turning and a thermodynamic analysis for absorption–compression hybrid refrigeration cycle

    International Nuclear Information System (INIS)

    Zheng Danxing; Meng Xuelin

    2012-01-01

    Highlights: ► Two novel fundamental concepts of the absorption refrigeration cycle were proposed. ► The interaction mechanism of compressor pressure increasing with other key-parameters was investigated. ► A set of optimal operating condition of hybrid refrigeration cycle was found. ► A simulation and investigation for R134a-DMF hybrid refrigeration cycle was performed. - Abstract: The absorption–compression hybrid refrigeration cycle has been considered as an effective approach to reduce the mechanical work consumption by using low-grade heat, such as solar energy. This work aims at studying the thermodynamic mechanism of the hybrid refrigeration cycle. Two fundamental concepts have been proposed, which are the ultimate refrigerating temperature (or the ultimate temperature lift) and the behavior turning. On the basis of that, the interaction mechanism of compressor pressure increasing with other key-parameters and the impact of compressor pressure increasing on the cycle performance have been investigated. The key-parameters include the concentration difference, the circulation ratio of working fluid, etc. The work points out that the hybrid refrigeration cycle performance varies with the change of compressor outlet pressure and depends on which one achieves dominance in the hybrid refrigeration cycle, the absorption sub-system or the compression sub-system. The behavior turning point during parameters changing corresponds to a maximum value of the heat powered coefficient of performance. In this case, the hybrid refrigeration cycle performance is optimal because the low-grade heat utilization is the most effective. In addition, to validate the theoretical analysis, a solar hybrid refrigeration cycle with R134a–DMF as working pair was simulated. The Peng–Robinson equation of state was adopted to calculate thermophysical properties when the reliability assessment of the prediction models on the available literature data of R134a–DMF system had been

  13. Two-phase Flow Ejector as Water Refrigerant by Using Waste Heat

    International Nuclear Information System (INIS)

    Yamanaka, H; Nakagawa, M

    2013-01-01

    Energy saving and the use of clean energy sources have recently become significant issues. It is expected that clean energy sources such as solar panels and fuel cells will be installed in many private dwellings. However, when electrical power is generated, exhaust heat is simultaneously produced. Especially for the summer season, the development of refrigeration systems that can use this waste heat is highly desirable. One approach is an ejector that can reduce the mechanical compression work required in a normal refrigeration cycle. We focus on the use of water as a refrigerant, since this can be safely implemented in private dwellings. Although the energy conversion efficiency is low, it is promising because it can use heat that would otherwise be discarded. However, a steam ejector refrigeration cycle requires a large amount of energy to change saturated water into vapour. Thus, we propose a more efficient two-phase flow ejector cycle. Experiments were carried out in which the quality of the two-phase flow from a tank was varied, and the efficiency of the ejector and nozzle was determined. The results show that a vacuum state can be achieved and suction exerted with a two-phase flow state at the ejector nozzle inlet.

  14. Thermoelectric refrigerator having improved temperature stabilization means

    International Nuclear Information System (INIS)

    Falco, C.M.

    1982-01-01

    A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized

  15. Environment-friendly refrigeration - Switzerland moves forward

    International Nuclear Information System (INIS)

    Stohler, F.

    2003-01-01

    This article presents an interview with Silvan Schaller, president of the Swiss Refrigeration Society SVK and head of a leading Swiss industrial refrigeration company, on the subject of the implementation of new Swiss materials legislation that regulates the use of various refrigerants. In particular, the co-operation between the Society and the regulatory authorities is stressed. The reasons behind the regulations - the protection of the environment and, in particular, the ozone layer - are discussed as are the efforts required by industry to meet them. Future refrigeration technologies and the choice of refrigerants are examined. Measures that will have to be taken by the companies in the refrigeration sector, such as the additional training of personnel and the monitoring of the disposal of wastes, are examined. For the future, the goal of reducing the energy consumption of refrigeration installations is noted

  16. Thermodynamic, Environmental and Economic Analyses of Solar Ejector Refrigeration System Application for Cold Storage

    OpenAIRE

    İbrahim ÜÇGÜL

    2009-01-01

    The refrigeration processes have been widely applied for especially in cold storages. In these plants, the systems working with compressed vapour cooling cycles have been used as a classical method. In general, electrical energy is used for compressing in these processes. Although, mainly the electricity itself has no pollution effect on the environment, the fossil fuels that are widely used to produce electricity in the most of the world, affect the nature terribly. In short, these refrigera...

  17. Fault diagnosis and refrigerant leak detection in vapour compression refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Tassou, S.A.; Grace, I.N. [Brunel University, Uxbridge (United Kingdom). Department of Mechanical Engineering

    2005-08-01

    The environmental impact of refrigeration systems can be reduced by operation at higher efficiency and reduction of refrigerant leakage. Refrigerant loss contributes both directly and indirectly to global warming through inefficient system operation, increased power consumption and greenhouse gas emissions and higher maintenance costs. Existing sensor-based leak detection methods are limited by the inability to detect gradual leakage and the need for careful sensor location. There is a requirement for a real-time performance monitoring approach to leak detection and fault diagnosis which overcomes these disadvantages. This paper reports on the development of a fault diagnosis and refrigerant leak detection system based on artificial intelligence and real-time performance monitoring. The system has been used successfully to distinguish between faulty and fault free operation, steady-state and transient operation, leakage and over charge conditions. Work currently underway is aimed at testing additional fault conditions and establishing further rules to distinguish between these patterns. (author)

  18. A high-resolution stochastic model of domestic activity patterns and electricity demand

    International Nuclear Information System (INIS)

    Widen, Joakim; Waeckelgard, Ewa

    2010-01-01

    Realistic time-resolved data on occupant behaviour, presence and energy use are important inputs to various types of simulations, including performance of small-scale energy systems and buildings' indoor climate, use of lighting and energy demand. This paper presents a modelling framework for stochastic generation of high-resolution series of such data. The model generates both synthetic activity sequences of individual household members, including occupancy states, and domestic electricity demand based on these patterns. The activity-generating model, based on non-homogeneous Markov chains that are tuned to an extensive empirical time-use data set, creates a realistic spread of activities over time, down to a 1-min resolution. A detailed validation against measurements shows that modelled power demand data for individual households as well as aggregate demand for an arbitrary number of households are highly realistic in terms of end-use composition, annual and diurnal variations, diversity between households, short time-scale fluctuations and load coincidence. An important aim with the model development has been to maintain a sound balance between complexity and output quality. Although the model yields a high-quality output, the proposed model structure is uncomplicated in comparison to other available domestic load models.

  19. Regulating Power from Supermarket Refrigeration

    DEFF Research Database (Denmark)

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

    2014-01-01

    the Danfoss refrigeration test centre. The complexities of modelling demand response are demonstrated through simulation. Simulations are conducted by placing the identified model in a direct-control demand response architecture, with power reference tracking using model predictive control. The energylimited......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...... nature of demand response from refrigeration is identified as the key consideration when considering participation in the regulating power market. It is demonstrated that by restricting the operating regions of the supermarket refrigeration system, a simple relationship can be found between the available...

  20. Impact of Demand Side Response on a Commercial Retail Refrigeration System

    Directory of Open Access Journals (Sweden)

    Ibrahim M. Saleh

    2018-02-01

    Full Text Available The UK National Grid has placed increased emphasis on the development of Demand Side Response (DSR tariff mechanisms to manage load at peak times. Refrigeration systems, along with HVAC, are estimated to consume 14% of the UK’s electricity and could have a significant role for DSR application. However, characterized by relatively low individual electrical loads and massive asset numbers, multiple low power refrigerators need aggregation for inclusion in these tariffs. In this paper, the impact of the Demand Side Response (DSR control mechanisms on food retailing refrigeration systems is investigated. The experiments are conducted in a test-rig built to resemble a typical small supermarket store. The paper demonstrates how the temperature and pressure profiles of the system, the active power and the drawn current of the compressors are affected following a rapid shut down and subsequent return to normal operation as a response to a DSR event. Moreover, risks and challenges associated with primary and secondary Firm Frequency Response (FFR mechanisms, where the load is rapidly shed at high speed in response to changes in grid frequency, is considered. For instance, measurements are included that show a significant increase in peak inrush currents of approx. 30% when the system returns to normal operation at the end of a DSR event. Consideration of how high inrush currents after a DSR event can produce voltage fluctuations of the supply and we assess risks to the local power supply system.

  1. ASPECTS ON THE EFFICIENCY OF MOBILE TEAM INTERVENTIONS ON ELECTRICAL ENERGY DISTRIBUTION EQUIPMENT TOWARDS DOMESTIC AND INDUSTRIAL CONSUMERS

    OpenAIRE

    Cristinel POPESCU

    2017-01-01

    The paper aims at presenting how to coordinate intervention teams in the event of failure regimes in electric power distribution installations to domestic and industrial low voltage consumers. The work was theoretically and practically supported by an application implemented within the Faculty of Engineering and coordinated by the author.

  2. 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.

  3. Transition to New Refrigerants

    Science.gov (United States)

    Overview page provides information on the refrigerants that motor vehicle air conditioners have used over time, with information on environmental impacts, refrigerant fitting sizes, label colors, and alternatives to ozone-depleting substances.

  4. Evaluation of Refrigerating and Air Conditioning Devices in Energy Cascade Systems under the Restriction of Carbon Dioxide Emissions

    Science.gov (United States)

    Shimazaki, Yoichi; Akisawa, Atsushi; Kashiwagi, Takao

    It is necessary to introduce energy cascade systems into the industrial sector in Japan to reduce carbon dioxide emissions. The aim of this study is to evaluate the refrigerating and air conditioning devices in cases of introducing both energy cascade systems and thermal recycling systems in industries located around urban areas. The authors have developed an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Limitation of carbon dioxide emissions results in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature one is shifted to refrigeration. It was found that increasing the amount of garbage combustor waste heat can reduce electric power for the turbo refrigerator by promoting waste heat driven ammonia absorption refrigerator.

  5. Design of a hybrid emissivity domestic electric oven

    Science.gov (United States)

    Isik, Ozgur; Onbasioglu, Seyhan Uygur

    2017-10-01

    In this study, the radiative properties of the surfaces of an electric oven were investigated. Using experimental data related to an oven-like enclosure, a novel combination of surface properties was developed. Three different surface emissivity combinations were analysed experimentally: low-emissivity, high emissivity (black-coated), and hybrid emissivity. The term "hybrid emissivity design" here corresponds to an enclosure with some high emissive and some low-emissive surfaces. The experiments were carried out according to the EN 50304 standard. When a brick (load) was placed in the enclosure, the view factors between its surfaces were calculated with the Monte Carlo method. These and the measured surface temperatures were then used to calculate the radiative heat fluxes on the surfaces of the load. The three different models were compared with respect to energy consumption and baking time. The hybrid model performed best, with the highest radiative heat transfer between the surfaces of the enclosure and the load and minimum heat loss from the cavity. Thus, it was the most efficient model with the lowest energy consumption and the shortest baking time. The recent European Union regulation regarding the energy labelling of domestic ovens was used.

  6. Experimental study on a resorption system for power and refrigeration cogeneration

    International Nuclear Information System (INIS)

    Jiang, L.; Wang, L.W.; Liu, C.Z.; Wang, R.Z.

    2016-01-01

    Energy conversion technologies, especially for power generation and refrigeration technologies driven by the low temperature heat, are gathering the momentum recently. This paper presents a novel resorption system for electricity and refrigeration cogeneraion. Compared with adsorption refrigeration system, resorption refrigeration is characterized as safety and simple structure since there is no ammonia liquid in the system. The cogeneration system is mainly composed of three HTS (high temperature salt) unit beds; three LTS (low temperature salts) unit beds, one expander, three ammonia valves, two oil valves, four water valves and connection pipes. Chemical working pair of MnCl 2 –CaCl 2 –NH 3 is selected. Since scroll expander is suitable for small type power generation system, it is chosen for expansion process. 4.8 kg MnCl 2 and 3.9 kg CaCl 2 impregnated in expanded natural graphite treated with sulfuric acid (ENG-TSA) are filled in the cogeneration system. Experimental results show that maximum cooling power 2.98 kW is able to be obtained while maximum shaft power is about 253 W with 82.3 W average value. The cogeneration system can be utilized for the heat source temperature lower than 170 °C. Total energy efficiency increases from 0.293 to 0.417 then decreases to 0.407 while exergy efficiency increases from 0.12 to 0.16. - Highlights: • A resorption system for power and refrigeration cogeneration is established and investigated. • ENG-TSA as the additive improves the heat and mass performance of composite adsorbent. • The highest shaft power and refrigeration power are 253 W and 2.98 kW, respectively. • Total energy efficiency of the system increases from 0.293 to 0.417 then decreases to 0.407.

  7. Current status of development on superconducting magnetic energy storage systems and magnetic refrigeration

    International Nuclear Information System (INIS)

    Hirano, Naoki

    2010-01-01

    Superconducting magnetic energy storage (SMES) systems have excellent characteristics as energy-storage equipment in power systems such as high efficiency, quick response, and no deterioration in repetitive operations. There are many projects to develop SMES throughout the world. Since 1991, a national project by the Agency for Natural Resources and Energy Japan has been working to develop an SMES system to control power in power systems. Moreover, SMES has been developed to compensate for momentary voltage dips since 2003. To reduce energy consumption due to prolonged operating times, we developed energy-conserving electrical equipment incorporating refrigerating aggregates such as air conditioners. We conduced R and D to convert magnetic refrigeration and highly-efficient, energy-conserving/environmentally friendly technologies, to practical applications. The current status in the development of SMES to control power systems, bridging to deal with instantaneous voltage dips, and magnetic refrigeration technology will be explained in this paper. (author)

  8. Influence of the nozzle angle on refrigeration performance of a gas wave refrigerator

    Science.gov (United States)

    Liu, P.; Zhu, Y.; Wang, H.; Zhu, C.; Zou, J.; Wu, J.; Hu, D.

    2017-05-01

    A gas wave refrigerator (GWR) is a novel refrigerating device that refrigerates a medium by shock waves and expansion waves generated by gas pressure energy. In a typical GWR, the injection energy losses between the nozzle and the expansion tube are essential factors which influence the refrigeration efficiency. In this study, numerical simulations are used to analyze the underlying mechanism of the injection energy losses. The results of simulations show that the vortex loss, mixing energy loss, and oblique shock wave reflection loss are the main factors contributing to the injection energy losses in the expansion tube. Furthermore, the jet angle of the gas is found to dominate the injection energy losses. Therefore, the optimum jet angle is theoretically calculated based on the velocity triangle method. The value of the optimum jet angle is found to be 4^{circ }, 8^{circ }, and 12^{circ } when the refrigeration efficiency is the first-order, second-order, and third-order maximum value over all working ranges of jet frequency, respectively. Finally, a series of experiments are conducted with the jet angle ranging from -4^{circ } to 12^{circ } at a constant expansion ratio. The results indicate the optimal jet angle obtained by the experiments is in good agreement with the calculated value. The isentropic refrigeration efficiency increased by about 4 % after the jet angle was optimized.

  9. Efficiency improvement of commercial refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Denecke, Julius [NTNU, Trondheim (Norway); Hafner, Armin [SINTEF Energy Research, Trondheim (Norway)

    2011-07-01

    This work presents a historical review of carbon dioxide refrigeration systems. Further a literature survey is carried out to get a status of existing refrigeration technology related to supermarkets. In the next step various energy saving options are stated. A heat recovery model, basing on a R744 booster refrigeration system is established and described. Simplified demand curves for refrigeration, air conditioning and heating will base this model to calculate different heat recovery layouts. Supermarket future trends will be considered and integrated in the calculation. Finally the calculated energy consumptions will be compared with real energy consumptions of selected supermarket refrigeration systems.

  10. 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...

  11. Computational tool for simulation of power and refrigeration cycles

    Science.gov (United States)

    Córdoba Tuta, E.; Reyes Orozco, M.

    2016-07-01

    Small improvement in thermal efficiency of power cycles brings huge cost savings in the production of electricity, for that reason have a tool for simulation of power cycles allows modeling the optimal changes for a best performance. There is also a big boom in research Organic Rankine Cycle (ORC), which aims to get electricity at low power through cogeneration, in which the working fluid is usually a refrigerant. A tool to design the elements of an ORC cycle and the selection of the working fluid would be helpful, because sources of heat from cogeneration are very different and in each case would be a custom design. In this work the development of a multiplatform software for the simulation of power cycles and refrigeration, which was implemented in the C ++ language and includes a graphical interface which was developed using multiplatform environment Qt and runs on operating systems Windows and Linux. The tool allows the design of custom power cycles, selection the type of fluid (thermodynamic properties are calculated through CoolProp library), calculate the plant efficiency, identify the fractions of flow in each branch and finally generates a report very educational in pdf format via the LaTeX tool.

  12. Prediction and analysis of the seasonal performance of tri-generation and CO2 refrigeration systems in supermarkets

    International Nuclear Information System (INIS)

    Ge, Y.T.; Tassou, S.A.; Suamir, I.N.

    2013-01-01

    Highlights: ► Integration model of a trigeneration with CO 2 refrigeration systems in supermarket. ► Validation of the developed integration model with site and laboratory measurement. ► Application of the trigeneration system in power generation and space conditioning. ► Performance analysis and comparison of the integrated system in supermarket. - Abstract: A modern supermarket energy control system has a concurrent need for electricity, space heating or cooling, and food refrigeration. The power supply to the supermarket is primarily from the national grid, where losses in efficiency are due to the processes of energy conversion and transmission. Combined heat and power (CHP) offers the potential to locally produce electrical power and heating which could save energy and reduce CO 2 emissions in the long run. During the summer months, as the space heating requirement in a supermarket is relatively small, the energy efficiency of a CHP installation can be improved by using excess thermal energy to drive a sorption refrigeration system to provide space cooling or refrigeration. This process is also known as tri-generation. In recent years, the use of CO 2 as a refrigerant in supermarkets has received considerable attention due to its negligible contribution to direct greenhouse gas emissions and excellent thermophysical and heat transfer properties. Consequently, the application of a tri-generation system in a supermarket with CO 2 refrigeration merits further investigation. In this paper, to evaluate the performance of a tri-generation system in the supermarket, a previously tested 80 kWe microturbine device was applied into an operational supermarket to generate power and provide space heating and cooling through exhaust heat. The performance evaluation and comparison for this tri-generation application is based on the prediction from an integrated model of supermarket energy control, cascade CO 2 refrigeration and tri-generation systems. The results

  13. 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.

  14. Overall performance of the duplex Stirling refrigerator

    International Nuclear Information System (INIS)

    Erbay, L. Berrin; Ozturk, M. Mete; Doğan, Bahadır

    2017-01-01

    Highlights: • Overall performance coefficient of duplex Stirling refrigerator was investigated. • A definite region for the coefficient of performance of the refrigerator in duplex Stirling is identified. • A definite region for the thermal efficiency of the heat engine in duplex Stirling is identified. • Benchmark values and design bounds of the duplex Stirling refrigerator were obtained. - Abstract: The duplex Stirling refrigerator is an integrated refrigerator consists of Stirling cycle engine and Stirling cycle refrigerator used for cooling. The equality of the work generation of the heat engine to the work consumption of the refrigerator is the primary constraint of the duplex Stirling. The duplex Stirling refrigerator is investigated thermodynamically by considering the effects of constructional and operational parameters which are namely the temperature ratios for heat engine and refrigerator, and the compression ratios for both sides. The primary concern is given to the parametric effects on the overall coefficient of performance of the duplex Stirling refrigerator. The given diagrams provide a design bounds and benchmark results that allows seeing the big picture about the cooling load and heat input relation. Moreover they ease to determine the corresponding work rate to the target cooling load. As regard to the obtained results, a definite region for coefficient of performance of the refrigerator and a definite region for the thermal efficiency of the heat engine of the duplex Stirling are identified.

  15. Electroluminescent refrigeration by ultra-efficient GaAs light-emitting diodes

    Science.gov (United States)

    Patrick Xiao, T.; Chen, Kaifeng; Santhanam, Parthiban; Fan, Shanhui; Yablonovitch, Eli

    2018-05-01

    Electroluminescence—the conversion of electrons to photons in a light-emitting diode (LED)—can be used as a mechanism for refrigeration, provided that the LED has an exceptionally high quantum efficiency. We investigate the practical limits of present optoelectronic technology for cooling applications by optimizing a GaAs/GaInP double heterostructure LED. We develop a model of the design based on the physics of detailed balance and the methods of statistical ray optics, and predict an external luminescence efficiency of ηext = 97.7% at 263 K. To enhance the cooling coefficient of performance, we pair the refrigerated LED with a photovoltaic cell, which partially recovers the emitted optical energy as electricity. For applications near room temperature and moderate power densities (1.0-10 mW/cm2), we project that an electroluminescent refrigerator can operate with up to 1.7× the coefficient of performance of thermoelectric coolers with ZT = 1, using the material quality in existing GaAs devices. We also predict superior cooling efficiency for cryogenic applications relative to both thermoelectric and laser cooling. Large improvements to these results are possible with optoelectronic devices that asymptotically approach unity luminescence efficiency.

  16. Improving the energy efficiency of industrial refrigeration systems

    International Nuclear Information System (INIS)

    Oh, Jin-Sik; Binns, Michael; Park, Sangmin; Kim, Jin-Kuk

    2016-01-01

    Various retrofit design options are available for improving the energy efficiency and economics of industrial refrigeration systems. This study considers a novel retrofit option using a mixed refrigerant (MR) in refrigeration cycles designed for use with a pure refrigerant (PR). In this way energy savings can be realized by switching refrigerants without requiring extensive and expensive reconfiguration of equipment. Hence, the aim here is to test the common thinking that equipment should always be extensively reconfigured when switching from pure to mixed refrigerants. To determine the most energy-efficient operating conditions for each refrigeration design an optimization framework is utilized linking a process simulator with an external optimization method. A case study is presented to demonstrate how the proposed process modeling and optimization framework can be applied and to illustrate the economic benefits of using the retrofit design options considered here. For the case considered in this paper, savings of shaft power required for the refrigeration cycle can be achieved from 16.3% to 27.2% when the pure refrigerant is replaced with mixed refrigerants and operating conditions are re-optimized. - Highlights: • Design methods for the design of refrigeration cycles in retrofit cases. • Consideration of mixed refrigerants to the existing multi-level pure-refrigerant cycles. • Optimization of refrigeration cycles with integrated use of a process simulator with an optimizer.

  17. Artificial neural network analysis of a refrigeration system with an evaporative condenser

    Energy Technology Data Exchange (ETDEWEB)

    Ertunc, H.M. [Department of Mechatronics Engineering, Kocaeli University, 41040 Kocaeli (Turkey); Hosoz, M. [Department of Mechanical Education, Kocaeli University, 41380 Kocaeli (Turkey)

    2006-04-01

    This paper describes an application of artificial neural networks (ANNs) to predict the performance of a refrigeration system with an evaporative condenser. In order to gather data for training and testing the proposed ANN, an experimental refrigeration system with an evaporative condenser was set up. Then, steady-state test runs were conducted varying the evaporator load, air and water flow rates passing through the condenser and both dry and wet bulb temperatures of the air stream entering the condenser. Utilizing some of the experimental data, an ANN model for the system based on standard backpropagation algorithm was developed. The ANN was used for predicting various performance parameters of the system, namely the condenser heat rejection rate, refrigerant mass flow rate, compressor power, electric power input to the compressor motor and the coefficient of performance. The ANN predictions usually agree well with the experimental values with correlation coefficients in the range of 0.933-1.000, mean relative errors in the range of 1.90-4.18% and very low root mean square errors. Results show that refrigeration systems, even complex ones involving concurrent heat and mass transfer such as systems with an evaporative condenser, can alternatively be modelled using ANNs within a high degree of accuracy. [Author].

  18. Thermodynamic simulation of ammonia-water absorption refrigeration system

    Directory of Open Access Journals (Sweden)

    Sathyabhama A.

    2008-01-01

    Full Text Available The ammonia-water absorption refrigeration system is attracting increasing research interests, since the system can be powered by waste thermal energy, thus reducing demand on electricity supply. The development of this technology demands reliable and effective system simulations. In this work, a thermodynamic simulation of the cycle is carried out to investigate the effects of different operating variables on the performance of the cycle. A computer program in C language is written for the performance analysis of the cycle.

  19. Optimising the refrigeration cycle with a two-stage centrifugal compressor and a flash intercooler

    Energy Technology Data Exchange (ETDEWEB)

    Roeyttae, Pekka; Turunen-Saaresti, Teemu; Honkatukia, Juha [Lappeenranta University of Technology, Laboratory of Energy and Environmental Technology, PO Box 20, 53851 Lappeenranta (Finland)

    2009-09-15

    The optimisation of a refrigeration process with a two-stage centrifugal compressor and flash intercooler is presented in this paper. The two-stage centrifugal compressor stages are on the same shaft and the electric motor is cooled with the refrigerant. The performance of the centrifugal compressor is evaluated based on semi-empirical specific-speed curves and the effect of the Reynolds number, surface roughness and tip clearance have also been taken into account. The thermodynamic and transport properties of the working fluids are modelled with a real-gas model. The condensing and evaporation temperatures, the temperature after the flash intercooler, and cooling power have been chosen as fixed values in the process. The aim is to gain a maximum coefficient of performance (COP). The method of optimisation, the operation of the compressor and flash intercooler, and the method for estimating the electric motor cooling are also discussed in the article. (author)

  20. Bio-mass stimulated absorption refrigerator for food storage in Papua New Guinea

    Energy Technology Data Exchange (ETDEWEB)

    Uppal, A.H.; Komuna, K.K. (University of Technology, Papua (New Guinea). Dept. of Mechanical Engineering)

    1992-01-01

    A medium capacity (140 litre) water-ammonia absorption refrigerator, thermally stimulated by a charcoal-stove is being developed to store food in remote locations and island communities of Papua New Guinea. The paper describes a prototype charcoal or biomass-stove thermal refrigerator in which the absorption cycle and thermo-syphonic cycle of a heating liquid has been coupled in a novel and straight forward approach. The system consisted of a heat-exchanger, in the form of a jacket surrounding the generator tube of a water-ammonia absorption cycle refrigerator, and was connected in a close-pipe work loop to a heat exchanger placed in a charcoal-stove. A heat-transfer oil flowed due to thermo-syphonic forces between the heat exchanger and the jacket. According to initial tests it took 4 hours for the system to warm up, and took another 7 hours for water in the freezer cabinet to approach 0{sup o}C from an initial 25{sup o}C. The cooling capacity of the evaporator was roughly 70% of the cooling capacity of the original system with electric heating. For a twelve hour test the stove consumed 2.5 kg of charcoal with an air port opening between 3 to 5 millimeters. Preliminary estimates indicate that the described prototype absorption unit stimulated by the wood/coconut husk stove (rather than electricity/kerosene), when manufactured commercially will cost less than US 1500 dollars at 1991 prices. (Author).

  1. Implementation of energy efficiency standards of household refrigerator/freezer in China: Potential environmental and economic impacts

    International Nuclear Information System (INIS)

    Tao, Jing; Yu, Suiran

    2011-01-01

    Due to the rapid economic development, living standards in China are improving fast. Chinese families are having more household electrical appliances, among which refrigerators are indispensable. Energy consumption of refrigerators is huge in China and causes environmental concerns. China has issued the national energy efficiency standards of household refrigerators, GB12021.2-2003 and GB12021.2-2008 to promote high-efficiency refrigerator production and use. This study evaluated the impacts of the standards on the environment, manufacturers and consumers over a long-term period of 2003-2023. It first evaluated the potential electricity conservation and GHG emission reduction resulting from energy efficiency improvements driven by the standards. Next, manufacturers' technological and economic concerns about complying with the standards were discussed. Some efficiency improving design options were considered and the resulting increases in manufacturing cost and retail price were estimated. The return of consumers from invest in efficiency was analyzed based on lifecycle cost saving of the improved models. The economical viability of the standards was then evaluated by national consumer costs and benefits. Results showed that the considered efficiency standards will potentially save a cumulative total of 588-1180 TWh electricity, and reduce emission of 629-1260 million tons of CO 2 , 4.00-8.04 million tons of SO x and 2.37-4.76 million tons of NO x by 2023, depending on sale share of models by efficiency. In a more environmentally optimal case (75% sale share of high-efficiency models), the national consumer benefits are 121 billion RMB (discounted), with the benefit/cost ratio of consumer's expenditure being 1.45:1. However, the preference to high-efficiency models is substantial influenced by consumer's expectation on return from the additional cost on efficiency.

  2. 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...

  3. 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 ...

  4. Magnetocaloric refrigeration near room temperature (invited)

    International Nuclear Information System (INIS)

    Brueck, E.; Tegus, O.; Thanh, D.T.C.; Buschow, K.H.J.

    2007-01-01

    Modern society relies on readily available refrigeration. The ideal cooling machine would be a compact, solid state, silent and energy-efficient heat pump that does not require maintenance. Magnetic refrigeration has three prominent advantages compared to compressor-based refrigeration. First, there are no harmful gases involved, second it may be built more compact as the working material is a solid and third magnetic refrigerators generate much less noise. Recently, a new class of magnetic refrigerant materials for room-temperature applications was discovered. These new materials have important advantages over existing magnetic coolants: They exhibit a large magnetocaloric effect (MCE) in conjunction with a magnetic phase transition of first order. This MCE is, larger than that of Gd metal, which is used in the demonstration refrigerators built to explore the potential of this evolving technology. In the present review, we compare the different materials considering both scientific aspects and industrial applicability

  5. 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.

  6. 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...

  7. Thermodynamic analysis of hydrocarbon refrigerants in a sub-cooling refrigeration system

    Directory of Open Access Journals (Sweden)

    BUKOLA O. BOLAJI

    2013-06-01

    Full Text Available In this study, the performance simulation of some hydrocarbon refrigerants (R290, R600 and R600a as alternatives to R134a in refrigeration system with sub-cooling is conducted by thermodynamic calculation of performance parameters using the REFPROP software. The results obtained showed that the saturated vapour pressure and temperature characteristic profiles for R600 and R600a are very close to that of R134a. The three hydrocarbon refrigerants exhibited very high refrigerating effect and condenser duty than R134a. The best of these parameters was obtained using R600. The discharge temperatures obtained using R600 and R600a were low, while that of R290 was very much higher. The highest coefficient of performance (COP and relative capacity index were obtained using R600. Average COPs of R600 and R600a are 4.6 and 2.2% higher than that of R134a, respectively. The performances of R600 and R600a in system were better than those of R134a and R290. The best performance was obtained using R600 in the system.

  8. Effect of Gaseous Ozone Exposure on the Bacteria Counts and Oxidative Properties of Ground Hanwoo Beef at Refrigeration Temperature.

    Science.gov (United States)

    Cho, Youngjae; Muhlisin; Choi, Ji Hye; Hahn, Tae-Wook; Lee, Sung Ki

    2014-01-01

    This study was designed to elucidate the effect of ozone exposure on the bacteria counts and oxidative properties of ground Hanwoo beef contaminated with Escherichia coli O157:H7 at refrigeration temperature. Ground beef was inoculated with 7 Log CFU/g of E. coli O157:H7 isolated from domestic pigs and was then subjected to ozone exposure (10×10(-6) kg O3 h(-1)) at 4℃ for 3 d. E. coli O157:H7, total aerobic and anaerobic bacterial growth and oxidative properties including instrumental color changes, TBARS, catalase (CAT) and glutathione peroxidase (GPx) activity were evaluated. Ozone exposure significantly prohibited (pgenerator inside a refrigerator. Further studies regarding the ozone concentrations and exposure times are needed.

  9. 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.

  10. 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...... traditionally are a pressure and a temperature sensor. In this thesis, a novel maximum slope-seeking (MSS) control method is developed. This has resulted in a control implementation, which successfully has been able to control the evaporator superheat in four widely different refrigeration system test...... problems. The method utilizes the qualitative nonlinearity in the system and harmonic analysis of a perturbation signal to reach an unknown, but suitable, operating point. Another important control task in refrigeration systems is to maintain the temperature of the refrigerated space or foodstuff within...

  11. Thermodynamic analysis of an absorption refrigeration system with ionic-liquid/refrigerant mixture as a working fluid

    International Nuclear Information System (INIS)

    Kim, Yoon Jo; Kim, Sarah; Joshi, Yogendra K.; Fedorov, Andrei G.; Kohl, Paul A.

    2012-01-01

    Thermodynamics of an ionic-liquid (IL) based absorption refrigeration system has been numerically analyzed. It provides an alternative to the normally toxic working fluids, such as the ammonia in conventional absorption systems. The use of ILs also eliminates crystallization and metal-compatibility problems of the water/LiBr system. Mixtures of refrigerants and imidazolium-based ILs are theoretically explored as the working fluid pairs in a miniature absorption refrigeration system, so as to utilize waste-heat to power a refrigeration/heat pump system for electronics cooling. A non-random two-liquid (NRTL) model was built and used to predict the solubility of the mixtures. Saturation temperatures at the evaporator and condenser were set at 25 °C and 50 °C, respectively, with the power dissipation of 100 W. Water in combination with [emim][BF 4 ] (1-ethyl-3-methylimidazolium tetrafluoroborate) gave the highest coefficient of performance (COP) around 0.9. The refrigerant/IL compatibility indicated by the circulation ratio, alkyl chain length of the IL, and thermodynamic properties of the refrigerants, such as latent heat of evaporation were proven to be important factors in determining the performance of the absorption system. The negative effect of high viscosity was mitigated by dilution of the IL with the refrigerant and the use of slightly larger microfluidic channel heat exchangers. -- Highlights: ► Mixtures of refrigerant/ionic-liquid are studied for absorption system. ► We carry out comprehensive theoretical thermodynamic analysis. ► The essential factors of refrigerant/IL affecting the performance are identified. ► Water/[emim][BF 4 ] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

  12. 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.

  13. Demand Response on domestic thermostatically controlled loads

    DEFF Research Database (Denmark)

    Lakshmanan, Venkatachalam

    . For a safe and reliable operation of electric power systems, the balance between electricity generation and consumption has to be maintained. The conventional fossil fuel based power generation achieves this balance by adjusting the generation to follow the consumption. In the electric power system......Electricity has become an inevitable part of human life in present day world. In the past two centuries, the electric power system has undergone a lot of changes. Due to the awareness about the adverse impact of the fossil fuels, the power industry is adopting green and sustainable energy sources....... In general, the electricity consumers are classified as industrial, commercial and domestic. In this dissertation, only the thermostatically controlled loads (TCLs) in the domestic segment are considered for the demand response study. The study is funded by Danish Council for Strategic Research (DCSR...

  14. A miniature adsorption3HE refrigerator

    International Nuclear Information System (INIS)

    Duband, L.; Ravex, A.; Lange, A.

    1991-01-01

    A self-contained, recyclable laboratory 3 He refrigerator has been developed. The refrigerator is very compact, portable and is designed to be safe and reliable. The unit can easily be installed on the cold plate of a superfluid 4 He cryostat. Once bolted on the cold plate, operation of the refrigerator is controlled by a single heater. In this new design the refrigerator has a cylindrical geometry. The adsorption pump is placed above the condensation point to prevent convection during the condensation phase and to improve the pumping speed. The inhibition of convection reduces the load on the 4 He bath and increases the condensation efficiency. This refrigeration technique has great potential for space applications. The absence of moving parts makes the system reliable and vibration free. Its simplicity and the absence of external components facilitate its integration on a cryostat. In fact, a rocket-borne 3 He refrigerator has already been successfully flown and has demonstrated the feasibility of this method

  15. Not all counterclockwise thermodynamic cycles are refrigerators

    Science.gov (United States)

    Dickerson, R. H.; Mottmann, J.

    2016-06-01

    Clockwise cycles on PV diagrams always represent heat engines. It is therefore tempting to assume that counterclockwise cycles always represent refrigerators. This common assumption is incorrect: most counterclockwise cycles cannot be refrigerators. This surprising result is explored here for quasi-static ideal gas cycles, and the necessary conditions for refrigeration cycles are clarified. Three logically self-consistent criteria can be used to determine if a counterclockwise cycle is a refrigerator. The most fundamental test compares the counterclockwise cycle with a correctly determined corresponding Carnot cycle. Other criteria we employ include a widely accepted description of the functional behavior of refrigerators, and a corollary to the second law that limits a refrigerator's coefficient of performance.

  16. Cryogenic mixed refrigerant processes

    CERN Document Server

    Venkatarathnam, Gadhiraju

    2010-01-01

    Teaches the need for refrigerant mixtures, the type of mixtures that can be used for different refrigeration and liquefaction applications, the different processes that can be used and the methods to be adopted for choosing the components of a mixture and their concentration for different applications.

  17. Thermoacoustic engines and refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.

    1996-12-31

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

  18. Leaking electricity in domestic appliances

    International Nuclear Information System (INIS)

    Meier, Alan; Rosen, Karen

    1999-01-01

    Many types of home electronic equipment draw electric power when switched off or not performing their principal functions. Standby power use (or ''leaking electricity'') for most appliances ranges from 1 - 20 watts. Even though standby use of each device is small, the combined standby power use of all appliances in a home can easily exceed 50 watts. Leaking electricity is already responsible for 5 to 10 percent of residential electricity use in the United States and over 10 percent in Japan. An increasing number of white goods also have standby power requirements. There is a growing international effort to limit standby power to around one watt per device. New and existing technologies are available to meet this target at little or no extra cost

  19. Refrigerator Efficiency in Ghana: Tailoring an appliance markettransformation program design for Africa

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-02-28

    A simple replication of developed country applianceefficiency labels and standards is unlikely to be feasible in Ghana andmany other countries in Africa. Yet by creatively modifying the developedcountry appliance efficiency market transformation model, it should bepossible to achieve dramatic energy use reductions. As was true indeveloped countries in the previous two decades, refrigeration efficiencyimprovements provide the greatest energy savings potential in theresidential electricity sector in Ghana. Although Ghana, like manyAfrican countries may impose standards on imports since Ghana does nothave manufacturing facilities for appliances in country. This approachmay hurt some consumers who patronize a very diverse market of usedappliances imported from Europe. We discuss how meeting the challenges ofthe Ghanaian market will require modification of the usual energyefficiency labeling and standards paradigm. But once a refrigeratormarket transformation is accomplished in Ghana, we estimate an averageenergy savings potential of 550 kWh/refrigerator/year, and a monetarysavings of more than $35/refrigerator/year. We discuss how this modifiedrefrigerator efficiency market transformation may occur in the Ghanaiancontext. If successful, this market transformation is likely to be anexample for many other African countries.

  20. United States: refrigeration industry blows hot

    International Nuclear Information System (INIS)

    Crawford, J.

    1997-01-01

    In the framework of the Kyoto convention on global warming, the american refrigeration industries have undertaken several organizations and contacts with governments and agencies in order to explain the real issues concerning the effects of refrigerant utilization in refrigerating machines on the greenhouse effect, taking into consideration the commercial impact that a ban on certain refrigerants could have on the industry's business. They argue that HFC utilization in this industry is fundamentally non-emissive and that important improvements have been realized concerning tightness and energy consumption

  1. Sorption compressor/mechanical expander hybrid refrigeration

    Science.gov (United States)

    Jones, J. A.; Britcliffe, M.

    1987-01-01

    Experience with Deep Space Network (DSN) ground-based cryogenic refrigerators has proved the reliability of the basic two-stage Gifford-McMahon helium refrigerator. A very long life cryogenic refrigeration system appears possible by combining this expansion system or a turbo expansion system with a hydride sorption compressor in place of the usual motor driven piston compressor. To test the feasibility of this system, a commercial Gifford-McMahon refrigerator was tested using hydrogen gas as the working fluid. Although no attempt was made to optimize the system for hydrogen operation, the refrigerator developed 1.3 W at 30 K and 6.6 W at 60 K. The results of the test and of theoretical performances of the hybrid compressor coupled to these expansion systems are presented.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-11

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

  3. 46 CFR 154.702 - Refrigerated carriage.

    Science.gov (United States)

    2010-10-01

    ... Pressure and Temperature Control § 154.702 Refrigerated carriage. (a) Each refrigeration system must: (1) Have enough capacity to maintain the cargo vapor pressure in each cargo tank served by the system below... the purpose of this section, a “refrigeration unit” includes a compressor and its motors and controls...

  4. 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.

  5. 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.

  6. 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.

  7. Magnetic hysteresis and refrigeration capacity of Ni–Mn–Ga alloys near Martensitic transformation

    International Nuclear Information System (INIS)

    Bin, Fu; Yi, Long; Jing-Fang, Duan; Chao-Lun, Wang; Yong-Qin, Chang; Rong-Chang, Ye; Guang-Heng, Wu

    2010-01-01

    This paper studies the magnetic hysteresis and refrigeration capacity of Ni-Mn-Ga alloys in detail during heating and cooling isothermal magnetisation processes. The Ni-Mn-Ga alloys show larger magnetic hysteresis when they transform from austenite to martensite, but smaller magnetic hysteresis when they transform from martensite to austenite. This behaviour is independent of either the pure Ni-Mn-Ga alloys or the alloys doped with other elements. Because of the existence of the magnetic hysteresis, the relation between the magnetic entropy change and refrigeration capacity is not simply linear. For practical consideration, magnetocaloric effect of Ni-Mn-Ga alloys should be investigated both on cooling and heating processes. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  8. 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.

  9. 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.

  10. Load forecasting of supermarket refrigeration

    DEFF Research Database (Denmark)

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

    2016-01-01

    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...... for handling the non-linear relations and that after applying an auto-regressive noise model the one-step ahead residuals do not contain further significant information....... 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...

  11. Coupling of the electrocaloric and electromechanical effects for solid-state refrigeration

    Science.gov (United States)

    Bradeško, A.; Juričić, Äń.; Santo Zarnik, M.; Malič, B.; Kutnjak, Z.; Rojac, T.

    2016-10-01

    Electrocaloric (EC) materials have shown the potential to replace some of the technologies in current commercial refrigeration systems. The key problem when fabricating an efficient EC refrigerator is the small adiabatic temperature change that current bulk materials can achieve. Therefore, such a solid-state EC refrigerator should be engineered to enhance the EC temperature change by rectifying the induced EC heat flow. Here, we present a numerical study of a device that couples the EC and electromechanical (EM) effects in a single active material. The device consists of several elements made from a functional material with coupled EC and EM properties, allowing the elements to bend and change their temperature with the application of an electric field. The periodic excitation of these elements results in a temperature span across the device. By assuming heat exchange with the environment and a low thermal contact resistivity between the elements, we show that a device with 15 elements and an EC effect of 1.2 K achieves a temperature span between the hot and cold sides of the device equal to 12.6 K. Since the temperature span can be controlled by the number of elements in the device, the results suggest that in combination with the so-called "giant" EC effect (ΔTEC ≥ 10 K), a very large temperature span would be possible. The results of this work should motivate the development of efficient EC refrigeration systems based on a coupling of the EC and EM effects.

  12. Raw milk from vending machines: Effects of boiling, microwave treatment, and refrigeration on microbiological quality.

    Science.gov (United States)

    Tremonte, Patrizio; Tipaldi, Luca; Succi, Mariantonietta; Pannella, Gianfranco; Falasca, Luisa; Capilongo, Valeria; Coppola, Raffaele; Sorrentino, Elena

    2014-01-01

    In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4 °C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  13. Suitability criterion for a refrigerant for use in solar operated sorption refrigerator

    International Nuclear Information System (INIS)

    Tabassum, S.A.; Mir, M.S.

    1996-01-01

    The thermodynamics of a sorption refrigeration cycle has been discussed representing the cycle on a clapeyron digram. The minimum generation temperature required has been determined using the 'd-a' equation which represents the sorption equilibrium of the pair, and Gibbs free energy relation. The mathematical relation developed provides a totally new basis for determination of suitability of a particular refrigerant. (author)

  14. Suitability criterion for a refrigerant for use in solar operated sorption refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Tabassum, S A; Mir, M S [University of Engineering and Technology, Lahore (Pakistan). Dept. of Mechanical Engineering

    1996-06-01

    The thermodynamics of a sorption refrigeration cycle has been discussed representing the cycle on a clapeyron digram. The minimum generation temperature required has been determined using the `d-a` equation which represents the sorption equilibrium of the pair, and Gibbs free energy relation. The mathematical relation developed provides a totally new basis for determination of suitability of a particular refrigerant. (author).

  15. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Parekh, M.

    1988-07-19

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

  17. Solar-driven refrigeration technologies; Koeltechnologieen op zonne-energie

    Energy Technology Data Exchange (ETDEWEB)

    De Cillis, S.; Infante Ferreira, C.A. [Technische Universiteit Delft, Delft (Netherlands); Krieg, J. [Unilever Foods and Health Research Institute, Vlaardingen (Netherlands)

    2005-12-01

    A review is presented of solar driven refrigeration technologies. A subdivision is made between electric driven and thermal driven systems. Their potential and stage of development are discussed. The electric driven systems include Stirling, thermo-acoustic, thermoelectric, electrochemical and membrane assisted absorption systems. The thermal driven systems include absorption and adsorption systems. A model is used to compare the performance of the different solutions. [Dutch] Dit artikel geeft een overzicht van zon-aangedreven koeltechnologieen. Er wordt onderscheid gemaakt tussen elektrisch en thermisch aangedreven systemen. Hun potentieel en niveau van ontwikkeling worden besproken. De elektrisch aangedreven systemen omvatten Stirling, thermo-akoestisch, thermo-elektrisch, elektrochemisch en membraanondersteund absorptiesystemen.De warmte-aangedreven systemen omvatten absorptie en adsorptie. Er wordt gebruik gemaakt van een model om de prestaties van de verschillende alternatieven onderling te vergelijken.

  18. High temperature refrigerator

    International Nuclear Information System (INIS)

    Steyert, W.A. Jr.

    1978-01-01

    A high temperature magnetic refrigerator is described which uses a Stirling-like cycle in which rotating magnetic working material is heated in zero field and adiabatically magnetized, cooled in high field, then adiabatically demagnetized. During this cycle the working material is in heat exchange with a pumped fluid which absorbs heat from a low temperature heat source and deposits heat in a high temperature reservoir. The magnetic refrigeration cycle operates at an efficiency 70% of Carnot

  19. 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.

  20. Refrigeration: Introducing energy saving opportunities for business

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-04-15

    In some industries, most notably food and drink and chemicals, refrigeration accounts for a significant proportion of overall site energy costs. For instance, in the industrial handling of meat, poultry and fish, it often accounts for 50% of total energy costs. In ice-cream production the proportion is 70%. In a number of commercial sectors, refrigeration also represents a significant proportion of overall energy costs. For example: Cold storage 90%; Food supermarkets 50%; Small shops with refrigerated cabinets 70% or over; Pubs and clubs 30%. Against these high costs, even a small reduction in refrigeration energy use can offer significant cost savings, resulting in increased profits. Energy saving need not be expensive. Energy savings of up to 20% can be realised in many refrigeration plant through actions that require little or no investment. In addition, improving the efficiency and reducing the load on a refrigeration plant can improve reliability and reduce the likelihood of a breakdown. Most organisations can save energy and money on refrigeration by: More efficient equipment; Good maintenance; Housekeeping and control. This publication provides an understanding of the operation of refrigeration systems, identifies where savings can be realised and will enable readers to present an informed case on energy savings to key decision makers within their organisation. (GB)

  1. Environmentally benign working pairs for adsorption refrigeration

    International Nuclear Information System (INIS)

    Cui Qun; Tao Gang; Chen Haijun; Guo Xinyue; Yao Huqing

    2005-01-01

    This paper begins from adsorption working pairs: water and ethanol were selected as refrigerants; 13x molecular sieve, silica gel, activated carbon, adsorbent NA and NB, proposed by authors, were selected as adsorbents, and the performance of adsorption working pairs in adsorption refrigeration cycle was studied. The adsorption isotherms of adsorbents (NA and NB) were obtained by high-vacuum gravimetric method. Desorption properties of adsorbents were analyzed and compared by thermal analysis method. The performance of adsorption refrigeration was studied on simulation device of adsorption refrigeration cycle. After presentation of adsorption isotherms, the thermodynamic performance for their use in adsorption refrigeration system was calculated. The results show: (1) the maximum adsorption capacity of water on adsorbent NA reaches 0.7 kg/kg, and the maximum adsorption capacity of ethanol on adsorbent NB is 0.68 kg/kg, which is three times that of ethanol on activated carbon, (2) the refrigeration capacity of NA-water working pair is 922 kJ/kg, the refrigeration capacity of NB-ethanol is 2.4 times that of activated carbon-methanol, (3) as environmental friendly and no public hazard adsorption working pair, NA-H 2 O and NB-ethanol can substitute activated carbon-methanol in adsorption refrigeration system using low-grade heat source

  2. Casebook on electric safety accidents

    International Nuclear Information System (INIS)

    1987-09-01

    This book gives concentration on electric safety accidents in domestic and abroad, which introduces general electrical safety with property of electricity, safe equipment and maintenance and protection of electric shock. It lists the cases of accident caused of electricity in domestic like accident in power substation, utilization equipment, load system and another accident by electricity like death in electric shock another by electricity like death in electric shock in new building construction, the cases caused of electricity in abroad like damage in electric shock by high voltage electric transformer, electric shock in summer and earth fault accident by fault cooling tower.

  3. 2014 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    2014-01-01

    The proceedings of the 2014 German refrigeration and air conditioning meeting contain contributions on the following topics: cryotechnology, fundamentals and materials for the refrigeration and heat pump technology, devices and components for the refrigeration and heat pump technology, applications of refrigeration technologies, air conditioning technology and heat pump applications, cryotechnology in biology and medicine, heat transfer and ventilation, guidelines and legal topics, refrigerant fluid - oil mixtures, control and surveillance, simulation and control, ambient air.

  4. Control of the Tevatron Satellite Refrigeration system

    International Nuclear Information System (INIS)

    Theilacker, J.; Chapman, L.; Gannon, J.; Hentges, M.; Martin, M.; Rode, C.H.; Zagel, J.

    1984-01-01

    This chapter describes a computerized control system for 24 satellite refrigerators which cool a six kilometer ring of superconducting magnets. The control system consists of 31 independent microprocessors operating over 400 servo loops, and a central computer system which provides monitoring, alarms, logging and changing of parameters. Topics considered include pressure measurement, flow measurement, temperature measurement, gas analysis, control valves, expansion engine controllers, and control loops. Each refrigerator has 12 active microprocessor based control loops which tune the refrigerator to one of its four operating modes: satellite, liquefier, refrigerator, and stand-by. It is suggested that optimizing the refrigerator control loops and quench recovery scheme will minimize the accelerator down time

  5. Performance characteristics of a quantum Diesel refrigeration cycle

    International Nuclear Information System (INIS)

    He Jizhou; Wang Hao; Liu Sanqiu

    2009-01-01

    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

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

    Science.gov (United States)

    Xiang, Bin; Montzka, Stephen A.; Miller, Scot M.; Elkins, James W.; Moore, Fred L.; Atlas, Elliot L.; Miller, Ben R.; Weiss, Ray F.; Prinn, Ronald G.; Wofsy, Steven C.

    2014-01-01

    HCFC-22 (CHClF2) and HFC-134a (CH2FCF3) are two major gases currently used worldwide in domestic and commercial refrigeration and air conditioning. HCFC-22 contributes to stratospheric ozone depletion, and both species are potent greenhouse gases. In this work, we study in situ observations of HCFC-22 and HFC-134a taken from research aircraft over the Pacific Ocean in a 3-y span [HIaper-Pole-to-Pole Observations (HIPPO) 2009–2011] and combine these data with long-term ground observations from global surface sites [National Oceanic and Atmospheric Administration (NOAA) and Advanced Global Atmospheric Gases Experiment (AGAGE) networks]. We find the global annual emissions of HCFC-22 and HFC-134a have increased substantially over the past two decades. Emissions of HFC-134a are consistently higher compared with the United Nations Framework Convention on Climate Change (UNFCCC) inventory since 2000, by 60% more in recent years (2009–2012). Apart from these decadal emission constraints, we also quantify recent seasonal emission patterns showing that summertime emissions of HCFC-22 and HFC-134a are two to three times higher than wintertime emissions. This unforeseen large seasonal variation indicates that unaccounted mechanisms controlling refrigerant gas emissions are missing in the existing inventory estimates. Possible mechanisms enhancing refrigerant losses in summer are (i) higher vapor pressure in the sealed compartment of the system at summer high temperatures and (ii) more frequent use and service of refrigerators and air conditioners in summer months. Our results suggest that engineering (e.g., better temperature/vibration-resistant system sealing and new system design of more compact/efficient components) and regulatory (e.g., reinforcing system service regulations) steps to improve containment of these gases from working devices could effectively reduce their release to the atmosphere. PMID:25422438

  7. ARTI refrigerant database. Quarterly report, March--May 1997

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1997-05-01

    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 an older refrigerants, to assist manufacturers and those using alternative refrigerants, to make comparisons and determine differences. The underlying purpose is to accelerate phase out of chemical compounds of environmental concern. The database provides bibliographic citations and abstracts for publications that may be useful in research and design of air-conditioning and refrigeration equipment. The complete documents are not included, though some may be added at a later date.

  8. Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

    International Nuclear Information System (INIS)

    Yang, Puqing; Zhang, Houcheng

    2015-01-01

    A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

  9. Effect of Oven Types on the Characteristics of Biscuits Made from Refrigerated and Frozen Doughs

    Directory of Open Access Journals (Sweden)

    Ismail Sait Dogan

    2006-01-01

    Full Text Available Characteristics of sugar snap and chocolate chip cookies, and hazelnut biscuits made from refrigerated and frozen dough were studied. Doughs were stored at 4 °C for 6 weeks and at –18 °C for 6 months, respectively. Physical characteristics of the biscuit samples such as spread, baking loss, surface colour and density were determined. Dough colour was not affected by storage time and temperatures. Biscuit characteristics did not change significantly during storage. Spread ratio was significantly lower for the biscuits baked in the gas oven than for the biscuits baked in the electric oven. Biscuit dough can be refrigerated for 6 weeks, and frozen for 6 months. Results also suggest that unique quality differences exist between the two ovens. For sugar snap cookies and hazelnut biscuits the electric oven without air circulation was better, while for chocolate chip cookies gas oven with air circulation was more suitable.

  10. Electric power prices, price control and competition on the European domestic electric power market. Stromtarife, Preisaufsicht und Wettbewerb im Europaeischen Binnenmarkt fuer Strom

    Energy Technology Data Exchange (ETDEWEB)

    Weigt, N

    1993-01-01

    If one speaks of electric power prices and price control in the year 1992, this subject has a different dimension than it did two or three years ago, when the new federal rate scale for electric power (ETO Elt) was drawn up and put into practice. Since the beginning of this year, a draft for guidelines which was drawn up by the EC Commission exists which, going on the assumption that the European domestic electric power market will set an example, does away with territorial protection and in the name of third party access (TPA) allows for electric power-line transit, thus introducing at least partial competition to the electric power market. We no longer think in terms of closed systems with clear-cut responsibilities in regard to power supply, which form the basis for the laws on electric power prices, the cartel laws, the practices of the electric power control board and the cartel authorities. Thus, using the new federal rate scale for electric power and its principles as formulated in Article 1 as a point of departure, developments will go in the direction of a competitive system in accordance with the ideas of the EC Commission and German free-enterprise theoreticians, as laid down for example by the deregulation commission. Thus developments will lead us away from the status quo in the direction of possible reforms, if not to say revolutionary structural changes and the consequnces which they will bring for price and cartel laws. (orig.)

  11. Optimum operating regimes of common paramagnetic refrigerants

    CERN Document Server

    Wikus, P; Figueroa-Feliciano, E

    2011-01-01

    Adiabatic Demagnetization Refrigerators (ADRs) are commonly used in cryogenic laboratories to achieve subkelvin temperatures. ADRs are also the technology of choice for several space borne instruments which make use of cryogenic microcalorimeters or bolometers {[}1-4]. For these applications, refrigerants with high ratios of cooling capacity to volume, or cooling capacity to mass are usually required. In this manuscript, two charts for the simple selection of the most suitable of several common refrigerants (CAA, CMN, CPA, DGG, FAA, GGG, GLF and MAS) are presented. These graphs are valid for single stage cycles. The selection of the refrigerants is uniquely dependent on the starting conditions of the refrigeration cycle (temperature and magnetic field density) and the desired final temperature. Only thermodynamic properties of the refrigerants have been taken into account, and other important factors such as availability and manufacturability have not been considered. (C) 2011 Elsevier Ltd. All rights reserve...

  12. Compatibility of refrigerants and lubricants with elastomers

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, G.R.; Seiple, R.H.

    1993-01-01

    The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. 97% of the swell measurements have been made to date. The other 3% of the measurements are contingent on availability of additional R-32. Swell behavior in the fluids have been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

  13. Refrigerating liquid prototype for LED's thermal management

    International Nuclear Information System (INIS)

    Faranda, Roberto; Guzzetti, Stefania; Lazaroiu, George Cristian; Leva, Sonia

    2012-01-01

    The heat management is the critical factor for high performance operation of LED. A new heat management application of refrigerating liquid integrated within a fabricated prototype is proposed and investigated. A series of experiments considering different heights of liquid level were performed to evaluate the heat dissipation performance and optical characteristics of the refrigerating liquid based prototype. The results reveal that the junction temperature decreases as the level of refrigerating liquid increases. The experimental results report that the refrigerating liquid reduces the junction temperature, and can positively influence the luminous radiation performances. An optimization investigation of the proposed solution was carried out to find an optimum thermal performance. The experiments indicated that refrigerating liquid cooling is a powerful way for heat dissipation of high power LEDs, and the fabrication of prototype was feasible and useful. - Highlights: ► New heat management application of refrigerating liquid on a fabricated LED prototype. ► Thermal models setup and comparison between the classical and the new solutions. ► The impact of refrigerating liquid level on LED thermal and luminous performances. ► The relationship between different levels of liquid with LED prototype performances.

  14. 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

  15. Deregulation of Electricity Market and Drivers of Demand for Electrical Energy in Industry

    Directory of Open Access Journals (Sweden)

    Bojnec Štefan

    2016-09-01

    Full Text Available This paper investigates deregulation of electricity market focusing on electricity prices and drivers of demand for electrical energy in industry in Slovenia. The patterns in evolution of real electricity price developments and the three main components of the electricity price are calculated: liberalized market share for purchased electricity price, regulated infrastructure share for use of electricity network grids and mandatory state charges in the sale of electricity (duty, excise duty and value-added tax. To calculate the real value of electricity prices, producer price index of industrial commodities for electricity prices in industry is used as deflator and implicit deflator of gross domestic product for the size of the economy. In the empirical econometric part is used regression analysis for the amount electricity consumption in the industry depending on the real gross domestic product, direct and cross-price elasticity for natural gas prices in the industry. The results confirmed volatility in real electricity price developments with their increasing tendency and the increasing share of different taxes and state charges in the electricity prices for industry. Demand for electrical energy in industry is positively associated with gross domestic product and price of natural gas as substitute for electrical energy in industry use, and negatively associated with prices of electrical energy for industry.

  16. Operating Manual of Helium Refrigerator (Rev. 2)

    Energy Technology Data Exchange (ETDEWEB)

    Song, K.M.; Son, S.H.; Kim, K.S.; Lee, S.K.; Kim, M.S. [Korea Electric Power Research Institute, Taejon (Korea)

    2002-07-01

    A helium refrigerator was installed as a supplier of 20K cold helium to the cryogenic distillation system of WTRF pilot plant. The operating procedures of the helium refrigerator, helium compressor and auxiliary apparatus are described for the safety and efficient operation in this manual. The function of the helium refrigerator is to remove the impurities from the compressed helium of about 250psig, to cool down the helium from ambient temperature to 20K through the heat exchanger and expansion engine and to transfer the cold helium to the cryogenic distillation system. For the smoothly operation of helium refrigerator, the preparation, the start-up, the cool-down and the shut-down of the helium refrigerator are described in this operating manual. (author). 3 refs., 14 tabs.

  17. Modified A{sup ++}-standard refrigerator with 30% reduction of energy consumption. Higher efficiency by compressor modification - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Siegrist, M.; Stahl, S.; Ganz, J.

    2010-06-15

    This final report for the Swiss Federal Office of Energy (SFOE) takes a look at how a modified refrigerator can be given a higher efficiency by modifying the compressor. The modified refrigerator was fitted with a variable-speed compressor. This compressor could be run at much lower speeds so that it was in operation for up to 90% of the time. It was shown that less electricity was consumed the more the compressor ran. The report discusses the aims of the work and presents details on the standard refrigerator used for the tests. The compressor normally used and the variable-speed compressor used in the test are described. Systems for temperature control and data acquisition during the tests are described. The results obtained are examined and the influence of various factors is discussed.

  18. Modelling of a chemisorption refrigeration and power cogeneration system

    International Nuclear Information System (INIS)

    Bao, Huashan; Wang, Yaodong; Roskilly, Anthony Paul

    2014-01-01

    Highlights: • An adsorption cogeneration was proposed and simulated for cooling and electricity. • A dynamic model was built and studied to demonstrate the variability of the system. • A dynamic model included the complex coupling of thermodynamic and chemical kinetic. • Mutual constrains between main components and optimisation methods were discussed. • The highest theoretical COP and exergy efficiency of cogeneration is 0.57 and 0.62. - Abstract: The present work for the first time explores the possibility of a small-scale cogeneration unit by combining solid–gas chemisorption refrigeration cycle and a scroll expander. The innovation in this work is the capability of producing refrigeration and electricity continuously and simultaneously without aggravating the energy scarcity and environmental impact. Individual modelling for each component, which has been validated by experimental data, was firstly investigated in order to identify the proper operation condition for the cogeneration mode achieving 1000 W power output. Subsequently, with the integrated modelling of two components the cogeneration performance was studied to demonstrate the viability of this concept. However, because of the mutual constraint between the chemisorption and the expansion when they link in series, the power output of the cogeneration mode was only around one third of the original expectation under the same condition identified in the individual modelling. Methods of improving the global performance including the selection of reactive mediums were also discussed and would be of referable value for the future practical investigation

  19. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P [ELF Atochem, Centre d` Application de Lavallois, 92 (France)

    1998-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  20. HFC perspectives in air-conditioning and refrigeration; Perspectives HFC en A/C et refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Fauvarque, P. [ELF Atochem, Centre d`Application de Lavallois, 92 (France)

    1997-12-31

    This paper is a series of transparencies dealing with the development of substitutes for the replacement of the R-22 refrigerant in air-conditioning systems (R-134a, R-407C, R-410A), and in industrial refrigeration systems of agriculture and food industry (R-134a and R-404A). (J.S.)

  1. Rotary magnetic refrigerator for superfluid helium production

    International Nuclear Information System (INIS)

    Hakuraku, Y.; Ogata, H.

    1986-01-01

    A new rotary-magnetic refrigerator designed to obtain superfluid helium temperatures by executing a magnetic Carnot cycle is developed. A rotor containing 12 magnetic refrigerants (gadolinium-gallium-garnet) is immersed in liquid helium at 4.2 K and rotated at constant speed in a steady magnetic field distribution. Performance tests demonstrate that the new rotary refrigerator is capable of obtaining a temperature of 1.48 K. The maximum useful cooling power obtained at 1.8 K is 1.81 W which corresponds to a refrigeration efficiency of 34%

  2. New magnetic refrigeration materials for the liquefaction of hydrogen

    International Nuclear Information System (INIS)

    Gschneidner, K.A.; Takeya, H.; Moorman, J.O.; Pecharsky, V.K.; Malik, S.K.; Zimm, C.B.

    1994-01-01

    Five heavy lanthanide ferromagnetic intermetallic compounds were studied as potential magnetic refrigerants for the liquefaction of hydrogen gas. (Dy 0.5 Er 0.5 )Al 2 and TbNi 2 appear to be better refrigerants than GdPd for a Joule-Brayton cycle refrigerator, while (Gd 0.54 Er 0.46 )AlNi seems to be a suitable refrigerant for an Ericsson cycle refrigerator

  3. Krypton based adsorption type cryogenic refrigerator

    Science.gov (United States)

    Jones, Jack A. (Inventor); Schember, Helene R. (Inventor)

    1989-01-01

    Krypton and a monolithic porous carbon such as Saran carbon are used respectively as the sorbate and sorbent of an adsorption type refrigerator to improve refrigeration efficiency and operational longevity.

  4. 76 FR 23281 - Bottom Mount Combination Refrigerator-Freezers From the Republic of Korea and Mexico: Initiation...

    Science.gov (United States)

    2011-04-26

    ... and Mexican markets were made at prices below the fully- absorbed cost of production (``COP''), within... calculating COP and CV and the Mexican bottom mount refrigerator models sold in the comparison market and the... Mexican hourly compensation rates for electrical equipment, appliance, and component manufacturing in 2007...

  5. Auto-refrigerating cascade for superconducting applications

    International Nuclear Information System (INIS)

    Forrest, S.M.; Hall, P.H.; Missimer, D.J.

    1987-01-01

    Extremely low temperatures, in the range of 230 to 90 K, are achieved in a single circuit compression refrigeration system operated by a conventional compressor. The system relies upon a series of intermediate cooling stages. The refrigerant is a mixture and the system employs fractional condensation, distillation, phase separation and intermediate heat transfer. Each stage includes the steps of withdrawing a portion of the liquid condensate from the compressed vapor-liquid refrigerant mixture which enters the stage. The withdrawn condensate is then throttled to a lower pressure and is mixed with the refrigerant being recycled to the compressor from the final evaporator. Evaporating the throttled condensate absorbs heat from and at least partially condenses the compressed uncondensed vapor in the compressed mixture

  6. 46 CFR 147.90 - Refrigerants.

    Science.gov (United States)

    2010-10-01

    .../ASHRAE 34-78 may be carried as ships' stores. (b) Refrigerants contained in a vessel's operating system... 46 Shipping 5 2010-10-01 2010-10-01 false Refrigerants. 147.90 Section 147.90 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS SHIPS' STORES Stowage and Other...

  7. Energy and exergy analysis of LPG (liquefied petroleum gas) as a drop in replacement for R134a in domestic refrigerators

    International Nuclear Information System (INIS)

    El-Morsi, Mohamed

    2015-01-01

    This study presents a comparison of energetic and exergetic performance of a vapour compression refrigeration system using pure HC (hydrocarbon) refrigerants. In this study, three different pure HCs propane (R290), butane (R600) and commercial LPG (liquefied petroleum gas) are used in the theoretical analysis. R134a is also used in the analysis as a reference refrigerant. The evaporator temperature ranges from −30 to 0 °C while the condenser ranges from 30 to 50 °C. MATLAB software is used for solving the thermodynamic equations, while the thermo-physical properties are calculated using REFPROP software. The results show that R600 has the highest COP c and exergetic efficiency, while LPG has the lowest. When compared to R134a, the COP c for R134a is higher than that for LPG by 10%. Also, the exergetic efficiency is higher by 5%. However, LPG has the advantage of being not expensive, available in large amounts and zero ozone depletion potential and low global warming potential. - Highlights: • The results show that R600 has the highest COP c & exergy efficiency, and the lowest irreversibility. • LPG has the lowest COP c & exergy efficiency, and the highest irreversibility. • Compared to R134a, LPG has a lower COP c and exergy efficiency by an average of 10% and 5%, respectively

  8. Export orientation and domestic electricity generation: Effects on energy efficiency innovation in select sectors

    International Nuclear Information System (INIS)

    Urpelainen, Johannes

    2011-01-01

    Why are some countries developing many energy efficiency innovations, while others are lagging behind? I argue that export orientation and electricity at low variable cost from nuclear and hydropower plants have an interactive effect on energy efficiency innovation. Export-oriented countries have strong incentives to invest in energy efficiency innovation, as they are in a position to export these technology innovations for global markets. But if inexpensive electricity is supplied in a country, the domestic demand for energy efficiency innovation is missing, and so the home market cannot serve as a springboard for international commercialization. I test this theory against international patent data on energy efficiency innovation in insulation, heating, and lighting for 22 OECD countries, 1991-2007. The statistical analysis indicates that export orientation has large positive effects on energy efficiency innovation in countries that do not rely on nuclear and hydroelectricity. - Highlights: → Export-oriented countries produce energy efficiency innovations. → Nuclear and hydropower reduce energy efficiency innovation. → Data on international patents from industrialized countries support the argument.

  9. 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

  10. Refrigeration plants using carbon dioxide as refrigerant: measuring and modelling the solubility and diffusion of carbon dioxide in polymers used as sealing materials

    DEFF Research Database (Denmark)

    von Solms, Nicolas; Kristensen, Jakob

    2010-01-01

    Because of increased environmental pressure, there is currently a movement away from more traditional refrigerants such as HCFC's toward refrigerants with lower global warming potential such as carbon dioxide (CO2). However, the use of CO2 as a refrigerant requires a refrigeration cycle...

  11. 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.

  12. Analysis of cooldown performance for Isabelle helium refrigerator

    International Nuclear Information System (INIS)

    Wu, K.C.; Brown, D.P.; Moore, R.W.

    1982-01-01

    The cooldown performance for the ISABELLE Helium refrigerator is analyzed in terms of the relationship between refrigerator and its load. The flow diagram for ISABELLE with its redundant turbines and heat exchangers is given. Cycle description and procedure for cooldown is described with the relationship between a refrigerator and its load illustrated. Pressure vs. temperature for ISABELLE load and the efficiency for a turbine are illustrated. The procedure for modeling the refrigerator and the concepts of maximizing the cooldown capacity are described. The results and discussion are accompanied with T-S diagrams for initial stage of cooldown and refrigerator characteristic at various return temperatures. The ISABELLE refrigerator with its reduncant expanders properly used achieves cooldown capacity well beyond its steady-state capacity. The cooldown rate at this stage relies on the design safety margin, which for the ISABELLE is 50%

  13. Refrigeration system having standing wave compressor

    Science.gov (United States)

    Lucas, Timothy S.

    1992-01-01

    A compression-evaporation refrigeration system, wherein gaseous compression of the refrigerant is provided by a standing wave compressor. The standing wave compressor is modified so as to provide a separate subcooling system for the refrigerant, so that efficiency losses due to flashing are reduced. Subcooling occurs when heat exchange is provided between the refrigerant and a heat pumping surface, which is exposed to the standing acoustic wave within the standing wave compressor. A variable capacity and variable discharge pressure for the standing wave compressor is provided. A control circuit simultaneously varies the capacity and discharge pressure in response to changing operating conditions, thereby maintaining the minimum discharge pressure needed for condensation to occur at any time. Thus, the power consumption of the standing wave compressor is reduced and system efficiency is improved.

  14. 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

  15. The disappearance of HCFC 22 and the search for the ideal refrigerant; La disparition du HCFC-22 et le recherche du refrigerant ideal

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, C. [Ville de Montreal, PQ (Canada). Direction des Immeubles Gestion de l' Energie et du Genie Climatique

    2003-03-01

    The City of Montreal, Quebec is searching for the optimum refrigerant, and has determined that ammonia, carbon dioxide, hydrocarbons and refrigerant-mixes in the 400 series are to be considered for general refrigeration and in skating rinks in the next years. The refrigerants of the 400 series contribute to the greenhouse effect and it is not possible to utilize them in sunk type systems. The City of Montreal has 12 per cent of ice surfaces in Quebec. The Montreal Protocol, a United Nations document calls for the gradual elimination of the refrigerant monochlorodifluoromethane (HCFC 22) starting in 2004 and that none will be made after 2020 in order to protect the ozone layer. In this document, the author discussed the following topics: (1) supply problems, regulations, international index used to compare refrigeration systems, (2) the origin of refrigerants available on the market and why the chemical industry is incapable of producing the miracle refrigerant, and (3) a proposal for an action plan for the control and the reduction of HCFC 22 leaks, the replacement of entire refrigeration systems and the preparation for the period following the availability of HCFC 22. The author offered twelve conclusions. 10 refs., 9 figs.

  16. 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

  17. 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, ...

  18. PARAMETRIC STUDY OF ENERGY, EXERGY AND THERMOECONOMIC ANALYSES ON VAPOR-COMPRESSION SYSTEM CASCADED WITH LIBR/WATER AND NH3/WATER ABSORBTION CASCADE REFRIGERATION CYCLE

    Directory of Open Access Journals (Sweden)

    ahmet selim dalkilic

    2017-03-01

    Full Text Available Energy savings on cooling systems can be performed by using novel refrigeration cycles. For this aim, vapour compression-vapour absorption cascade refrigeration systems can be considered as substitute to single-stage vapour compression refrigeration systems. Renewable energy sources of geothermal and solar heat, waste heat of processes have been used by these cycles to provide cooling and they also require less electrical energy than vapour compression cycles having alternative refrigerants. In this study, a vapour compression (VC and vapour absorption (VA cascade systems are analysed with the second law analysis for varied cooling capacities. While lithium bromide-water and NH3/H2O are the working fluids in VA part, various refrigerants are used in VC section. The refrigerants of R134a and R600a, R410A and R407C are tested as drop in alternatives for R12 and R22, respectively. The effects of alteration in cooling capacity, superheating and sub cooling in VC part, temperature in the generator and absorber, and degree of overlap in cascade condenser in VA part on the coefficient of system performance are studied. Validation of the results have been performed by the values given in the literature. Improvement in COP of VC, VA and cascade system are obtained separately. According to the analyses, cascade systems’ COP values increase with increasing the temperatures of generator and evaporator and they also increase with decreasing the condenser and absorber temperatures. Moreover, the generator has the highest exergy destruction rates, second and third one were the condenser and absorber, respectively. Electricity consumption and payback period are also determined considering the various parameters of the study.

  19. The climate change implications of manufacturing refrigerants. A calculation of 'production' energy contents of some common refrigerants

    International Nuclear Information System (INIS)

    Campbell, N.J.; McCulloch, A.

    1998-01-01

    Total Equivalent Warming Impact (TEWI) analysis has been shown to be a useful aid to quantifying the climate change effect of potential emissions from the operation of systems that involve the use of greenhouse gases and consume energy, so generating CO 2 emissions. It enables these systems to be optimized for minimum global warming impact. In previous studies, the energies required to manufacture the greenhouse gases themselves were not included; by analogy with other chemical manufacturing processes they were assumed to be small in the context of climate change. In the work described here, climate change impacts from the energy used to produce a number of common refrigerant fluids are evaluated. These impacts are compared with the potential impact on global warming from the other components of TEWI: use and disposal of the refrigerants, including direct release into the environment. It is shown that the implications for climate change of the production of traditional refrigerants like ammonia, hydrocarbons or CFC-12 and new refrigerating fluids, such as HFC-134a, are truly insignificant in comparison with other stages of the life cycle of a refrigerator and have no role in TEWI. (author)

  20. Possibility of using adsorption refrigeration unit in district heating network

    Science.gov (United States)

    Grzebielec, Andrzej; Rusowicz, Artur; Jaworski, Maciej; Laskowski, Rafał

    2015-09-01

    Adsorption refrigeration systems are able to work with heat sources of temperature starting with 50 °C. The aim of the article is to determine whether in terms of technical and economic issues adsorption refrigeration equipment can work as elements that produce cold using hot water from the district heating network. For this purpose, examined was the work of the adsorption air conditioning equipment cooperating with drycooler, and the opportunities offered by the district heating network in Warsaw during the summer. It turns out that the efficiency of the adsorption device from the economic perspective is not sufficient for production of cold even during the transitional period. The main problem is not the low temperature of the water supply, but the large difference between the coefficients of performance, COPs, of adsorption device and a traditional compressor air conditioning unit. When outside air temperature is 25 °C, the COP of the compressor type reaches a value of 4.49, whereas that of the adsorption device in the same conditions is 0.14. The ratio of the COPs is 32. At the same time ratio between the price of 1 kWh of electric power and 1 kWh of heat is only 2.85. Adsorption refrigeration equipment to be able to compete with compressor devices, should feature COPads efficiency to be greater than 1.52. At such a low driving temperature and even changing the drycooler into the evaporative cooler it is not currently possible to achieve.

  1. Component-wise exergy and energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

    Science.gov (United States)

    Gill, Jatinder; Singh, Jagdev

    2017-11-01

    In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor compression refrigeration system. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG refrigeration system was found lower by approximately 11.13-3.41%, 2.24-3.43%, 12.02-13.47% and 1.54-5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in refrigeration systems. The refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG refrigeration system were detected higher and lower compared to the R134a refrigeration system by about 7.04-11.41%, 15.1-17.82%, and 3.83-8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.

  2. Component-wise exergy and energy analysis of vapor compression refrigeration system using mixture of R134a and LPG as refrigerant

    Science.gov (United States)

    Gill, Jatinder; Singh, Jagdev

    2018-05-01

    In this work, the experimental examination was carried out using a mixture of R134a and LPG refrigerant (consisting of R134a and LPG in a proportion of 28:72 by weight) as a replacement for R134a in a vapor compression refrigeration system. Exergy and energy tests were carried out at different evaporator and condenser temperatures with controlled environmental conditions. The results showed that the exergy destruction in the compressor, condenser, evaporator, and a capillary tube of the R134a / LPG refrigeration system was found lower by approximately 11.13-3.41%, 2.24-3.43%, 12.02-13.47% and 1.54-5.61% respectively. The compressor exhibits the highest level of destruction, accompanied by a condenser, an evaporator and a capillary tube in refrigeration systems. The refrigeration capacity, COP and power consumption of the compressor of the R134a /LPG refrigeration system were detected higher and lower compared to the R134a refrigeration system by about 7.04-11.41%, 15.1-17.82%, and 3.83-8.08% respectively. Also, the miscibility of R134a and LPG blend with mineral oil discovered good. The R134a and LPG refrigerant mixture proposed in this study perform superior to R134a from component-wise exergy and energy analyses under similar experimental conditions.

  3. Experimental investigation of a direct driven radial compressor for domestic heat pumps

    Energy Technology Data Exchange (ETDEWEB)

    Schiffmann, J. [Fischer Engineering Solutions AG, Birkenweg 3, CH-3360 Herzogenbuchsee (Switzerland); Favrat, D. [Ecole Polytechnique Federale de Lausanne, EPFL STI IGM LENI, Station 9, CH-1015 Lausanne (Switzerland)

    2009-12-15

    The presence of oil in domestic heat pumps is an obstacle toward higher efficiency, particularly for enhanced surface evaporators and for advanced concepts based on two-stage cycles. Very compact direct driven radial compressors supported on oil-free bearings represent a promising alternative. This paper presents the derivation of the specifications, the choice for an appropriate refrigerant fluid and the design of a proof of concept prototype with the various tradeoffs between the impeller characteristics to follow the seasonal heat demand, the bearing and rotordynamics for a stable operation. Heat pump simulation results, the design of the impeller as well as the layout of the experimental facility and first experimental results are presented. An impeller with a tip diameter of 20 mm has been tested at rotational speeds of up to 210 krpm reaching pressure ratios in excess of 3.3 and efficiencies above 78%. The refrigerant chosen for this first experimental approach is HFC 134a. (author)

  4. 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, ...

  5. Correlation of refrigerant mass flow rate through adiabatic capillary tubes using mixture refrigerant carbondioxide and ethane for low temperature applications

    Science.gov (United States)

    Nasruddin, Syaka, Darwin R. B.; Alhamid, M. Idrus

    2012-06-01

    Various binary mixtures of carbon dioxide and hydrocarbons, especially propane or ethane, as alternative natural refrigerants to Chlorofluorocarbons (CFCs) or Hydro fluorocarbons (HFCs) are presented in this paper. Their environmental performance is friendly, with an ozone depletion potential (ODP) of zero and Global-warming potential (GWP) smaller than 20. The capillary tube performance for the alternative refrigerant HFC HCand mixed refrigerants have been widely studied. However, studies that discuss the performance of the capillary tube to a mixture of natural refrigerants, in particular a mixture of azeotrope carbon dioxide and ethane is still undeveloped. A method of empirical correlation to determine the mass flow rate and pipe length has an important role in the design of the capillary tube for industrial refrigeration. Based on the variables that effect the rate of mass flow of refrigerant in the capillary tube, the Buckingham Pi theorem formulated eight non-dimensional parameters to be developed into an empirical equations correlation. Furthermore, non-linear regression analysis used to determine the co-efficiency and exponent of this empirical correlation based on experimental verification of the results database.

  6. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere,1 mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel.

  7. Simulator for design absorption refrigeration system; Simulador para projeto de ciclos de refrigeracao por absorcao

    Energy Technology Data Exchange (ETDEWEB)

    Morejon, C.F.M.; Brum, N. de C. [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia. Programa de Engenharia Mecanica]. E-mails: Camilo_freddy@hotmail.com; Nisio@serv.com.ufrj.br

    2000-07-01

    This work presents a development of a thermal fluid dynamics model and a solution of a steady state absorption refrigeration cycle, with ammonia water as the working fluid. Analytical thermodynamics models expressing the enthalpy in function of pressure, temperature and composition (h=f(P,T,x)), are used with the aim to design all of the cycle devices, moved by any type of energy such as solar, natural gas, steam or electrical energy (Morejon and Hackenberg, 1978). The development of the analysis is carried out by the application of thermal fluid dynamics concepts together with a detailed study of the heat and mass transfer in the different cycle stages. The thermodynamic cycle model, obtained from equation of state for ammonia - water mixtures (Ziegker and Trepp, 1984), is represented by the relation h - x (enthalpy-composition) for different pressures and temperatures. The obtained models are used to implement computational codes in MAPLE-V facilitating the design and simulation of refrigeration system. This study can be applied in the systems of air conditioning and refrigeration chambers design. (author)

  8. Using waste heat of ship as energy source for an absorption refrigeration system

    International Nuclear Information System (INIS)

    Salmi, Waltteri; Vanttola, Juha; Elg, Mia; Kuosa, Maunu; Lahdelma, Risto

    2017-01-01

    Highlights: • A steady-state thermodynamic model is developed for absorption refrigeration in a ship. • Operation profile of B.Delta37 bulk carrier is used as an initial data. • Suitability of water-LiBr and ammonia-water working pairs were validated. • Coefficient of performance (COP) was studied in ISO and tropical conditions. • Estimated energy savings were 47 and 95 tons of fuel every year. - Abstract: This work presents a steady-state thermodynamic model for absorption refrigeration cycles with water-LiBr and ammonia-water working pairs for purpose of application on a ship. The coefficient of performance was studied with different generator and evaporator temperatures in ISO and tropical conditions. Absorption refrigeration systems were examined using exhaust gases, jacket water, and scavenge air as energy sources. Optimal generator temperatures for different refrigerant temperatures were found using different waste heat sources and for the absorption cycle itself. Critical temperature values (where the refrigeration power drops to zero) were defined. All of these values were used in order to evaluate the cooling power and energy production possibilities in a bulk carrier. The process data of exhaust gases and cooling water flows in two different climate conditions (ISO and tropical) and operation profiles of a B. Delta37 bulk carrier were used as initial data in the study. With the case ship data, a theoretical potential of saving of 70% of the electricity used in accommodation (AC use) compressor in ISO conditions and 61% in tropical conditions was recognized. Those estimates enable between 47 and 95 tons of annual fuel savings, respectively. Moreover, jacket water heat recovery with a water-LiBr system has the potential to provide 2.2–4.0 times more cooling power than required during sea-time operations in ISO conditions, depending on the main engine load.

  9. 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

  10. 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.

  11. A comparative study of different heat exchange systems in a thermoelectric refrigerator and their influence on the efficiency

    International Nuclear Information System (INIS)

    Astrain, D.; Aranguren, P.; Martínez, A.; Rodríguez, A.; Pérez, M.G.

    2016-01-01

    Highlights: • Total efficiency optimisation of a thermoelectric refrigerator. • Experimental study of three different types of heat exchangers for thermoelectrics. • Influence of the occupancy ratio in thermal resistance. • Important decrease in the electric consumption of a thermoelectric refrigerator. - Abstract: Thermoelectric refrigeration (TEC) exhibits several advantages compared to vapour-compression, since this technology presents accurate temperature control systems and higher levels of compactness, robustness and noiselessness. However, its low efficiency is acting as a deterrent for it to spread in the refrigeration market. One of the factors determining the efficiency of a thermoelectric refrigerator is the temperature difference between the hot and cold sides of the thermoelectric modules (TEMs). This is dependent on the thermal resistances of the heat exchangers used. This paper discusses the results of an experimental study of different types of heat exchangers for the thermoelectric module hot side: a water–air system comprising a cold plate, pump and fan coil; a finned heat sink with fan; a heat pipe with fan. Expressions of thermal resistance have been obtained for these three types as a function of the air and water mass flows and the number of TEMs per unit of surface area of heat exchanger (occupancy ratio, δ), as well as expressions of the power consumed by the fans and the pump. Finally, a computational study has been carried out on a thermoelectric refrigerator of 15 m"3 of interior volume, in order to obtain the influence of the heat exchanger studied, on the total consumption of the refrigerator and its efficiency. The results have demonstrated that relevant improvements can be made in TEC efficiency by the proper optimisation of the heat exchangers.

  12. Control Methods for Energy Management of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan

    is decreased as the method does not need an explicit model of the system and, at the same time, the desired load following performance is attained. Recent research findings indicate that the refrigeration system commonly employed in food transportation can account for 40% of the total greenhouse gas emissions...... from the corresponding vehicle engines. Finally, the problem of optimization of a hybrid transport refrigeration system is addressed here. The hybrid refrigeration system is made by the integration of conventional refrigeration technology with thermal energy storage devices....

  13. Comparative gross domestic production and electricity consumption per capita in the context of nuclear power prospect

    International Nuclear Information System (INIS)

    Ridzuan Abdul Mutalib; Maragatham Kumar; Nik Arlina Nik Ali; Abi Muttaqin Jalal Bayar; Aisya Raihan Abdul Kadir; Muhammed Zulfakar Zolkaffly; Azlinda Aziz; Jamal Khaer Ibrahim

    2008-08-01

    Malaysia, based on its economic and industrial growth level should be able to absorb nuclear technology and capacity in implementing a nuclear power programme. Malaysia Gross Domestic Production (GDP) and electricity consumption (kWh per capita is higher compared with other developing countries, which have already announced their plans to implement nuclear power programme. Furthermore, Asia reliance on nuclear power plants to meet growing energy needs in the near future is also significantly increasing. This paper presents the comparative GDP and kWh per capita in Asia and globally in the context of nuclear power prospect in Malaysia. (Author)

  14. Prediction of thermodynamic properties of refrigerants using data mining

    International Nuclear Information System (INIS)

    Kuecueksille, Ecir Ugur; Selbas, Resat; Sencan, Arzu

    2011-01-01

    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.

  15. Exergy analysis of refrigerators for large scale cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Loehlein, K [Sulzer Cryogenics, Winterthur (Switzerland); Fukano, T [Nippon Sanso Corp., Kawasaki (Japan)

    1993-01-01

    Facilities with superconducting magnets require cooling capacity at different temperature levels and of different types (refrigeration or liquefaction). The bigger the demand for refrigeration, the more investment for improved efficiency of the refrigeration plant is justified and desired. Refrigeration cycles are built with discrete components like expansion turbines, cold compressors, etc. Therefore the exergetic efficiency for producing refrigeration on a distinct temperature level is significantly dependent on the 'thermodynamic arrangement' of these components. Among a variety of possibilities, limited by the range of applicability of the components, one has to choose the best design for higher efficiency on every level. Some influences are being quantified and aspects are given for a optimal integration of the refrigerator into the whole cooling system. (orig.).

  16. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Special Design and Operating Requirements § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene...

  17. Simulation of the Energy Saver refrigeration system

    International Nuclear Information System (INIS)

    Barton, H.R. Jr.; Nicholls, J.E.; Mulholland, G.T.

    1981-10-01

    The helium refrigeration for the Energy Saver is supplied by a Central Helium Liquefier and 24 Satellite Refrigerators installed over a 1-1/4 square mile area. An interactive, software simulator has been developed to calculate the refrigeration available from the cryogenic system over a wide range of operating conditions. The refrigeration system simulator incorporates models of the components which have been developed to quantitatively describe changes in system performance. The simulator output is presented in a real-time display which has been used to search for the optimal operating conditions of the Satellite-Central system, to examine the effect of an extended range of operating parameters and to identify equipment modifications which would improve the system performance

  18. 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

  19. 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.

  20. Basics of Low-temperature Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, A [Linde AG, Munich (Germany)

    2014-07-01

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

  1. Evaluation of Virtual Refrigerant Mass Flow Sensors

    OpenAIRE

    Kim, Woohyun; Braun, James E.

    2012-01-01

    Refrigerant mass flow rate is an important measurement for monitoring equipment performance and enabling fault detection and diagnostics. However, a traditional mass flow meter is expensive to purchase and install. A virtual refrigerant mass flow sensor (VRMF) uses a mathematical model to estimate flow rate using low-cost measurements and can potentially be implemented at low cost. This study evaluates three VRMFs for estimating refrigerant mass flow rate. The first model uses a compressor ma...

  2. Compatibility of refrigerants and lubricants with elastomers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, G.R.; Seiple, R.H.; Taikum, Orawan

    1994-01-01

    The information contained in this report is designed to assist the air-conditioning and refrigeration industry in the selection of suitable elastomeric gasket and seal materials that will prove useful in various refrigerant and refrigeration lubricant environments. In part I of the program the swell behavior in the test fluids has been determined using weight and in situ diameter measurements for the refrigerants and weight, diameter and thickness measurements for the lubricants. Weight and diameter measurements are repeated after 2 and 24 hours for samples removed fro the refrigerant test fluids and 24 hours after removal from the lubricants. Part II of the testing program includes the evaluation of tensile strength, hardness, weight, and dimensional changes after immersion aging in refrigerant/lubricant mixtures of selected elastomer formulations at elevated temperature and pressure.

  3. Simulation of an air conditioning absorption refrigeration system in a co-generation process combining a proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pilatowsky, I.; Gamboa, S.A.; Rivera, W. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Romero, R.J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas - UAEM, Cuernavaca, Morelos (Mexico); Isaza, C.A. [Universidad Pontificia Bolivariana, Medellin (Colombia). Instituto de Energia y Termodinamica; Sebastian, P.J. [Centro de Investigacion en Energia - UNAM, Temixco, Morelos (Mexico); Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico); Moreira, J. [Cuerpo Academico de Energia y Sustentabilidad-UP Chiapas, Tuxtla Gutierrez, Chiapas (Mexico)

    2007-10-15

    In this work, a computer simulation program was developed to determine the optimum operating conditions of an air conditioning system during the co-generation process. A 1 kW PEMFC was considered in this study with a chemical/electrical theoretical efficiency of 40% and a thermal efficiency of 30% applying an electrical load of 100%. A refrigeration-absorption cycle (RAC) operating with monomethylamine-water solutions (MMA-WS), with low vapor generation temperatures (up to 80 C) is proposed in this work. The computer simulation was based on the refrigeration production capacity at the maximum power capacity of the PEMFC. Heat losses between the fuel cell and the absorption air conditioning system at standard operating conditions were considered to be negligible. The results showed the feasibility of using PEMFC for cooling, increasing the total efficiency of the fuel cell system. (author)

  4. A rotary permanent magnet magnetic refrigerator based on AMR cycle

    International Nuclear Information System (INIS)

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

    2016-01-01

    Magnetic refrigeration is an emerging, environment-friendly technology based on a magnetic solid that acts as a refrigerant by magneto-caloric effect (MCE). The reference cycle for magnetic refrigeration is AMR (Active Magnetic Regenerative refrigeration). In order to demonstrate the potential of magnetic refrigeration to provide useful cooling in the near room temperature range, a novel Rotary Permanent Magnet Magnetic Refrigerator (RPMMR) is described in this paper. Gadolinium has been selected as magnetic refrigerant and demineralized water has been employed as regenerating fluid. The total mass of gadolinium (1.20 kg), shaped as packed bed spheres, is housed in 8 regenerators. A magnetic system, based on a double U configuration of permanent magnets, provides a magnetic flux density of 1.25 T with an air gap of 43 mm. A rotary vane pump forces the regenerating fluid through the regenerators. The operational principle of the magnetic refrigerator and initial experimental results are reported and analyzed.

  5. Technical support document: Energy efficiency standards for consumer products: Refrigerators, refrigerator-freezers, and freezers including draft environmental assessment, regulatory impact analysis

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The Energy Policy and Conservation Act (P.L. 94-163), as amended by the National Appliance Energy Conservation Act of 1987 (P.L. 100-12) and by the National Appliance Energy Conservation Amendments of 1988 (P.L. 100-357), and by the Energy Policy Act of 1992 (P.L. 102-486), provides energy conservation standards for 12 of the 13 types of consumer products` covered by the Act, and authorizes the Secretary of Energy to prescribe amended or new energy standards for each type (or class) of covered product. The assessment of the proposed standards for refrigerators, refrigerator-freezers, and freezers presented in this document is designed to evaluate their economic impacts according to the criteria in the Act. It includes an engineering analysis of the cost and performance of design options to improve the efficiency of the products; forecasts of the number and average efficiency of products sold, the amount of energy the products will consume, and their prices and operating expenses; a determination of change in investment, revenues, and costs to manufacturers of the products; a calculation of the costs and benefits to consumers, electric utilities, and the nation as a whole; and an assessment of the environmental impacts of the proposed standards.

  6. Electricity demand in Tunisia

    International Nuclear Information System (INIS)

    Gam, Imen; Ben Rejeb, Jaleleddine

    2012-01-01

    This paper examines the global electricity demand in Tunisia as a function of gross domestic product in constant price, the degree of urbanization, the average annual temperature, and the real electricity price per Kwh. This demand will be examined employing annual data over a period spanning almost thirty one years from 1976 to 2006. A long run relationship between the variables under consideration is determined using the Vector Autoregressive Regression. The empirical results suggest that the electricity demand in Tunisia is sensitive to its past value, any changes in gross domestic product and electricity price. The electricity price effects have a negative impact on long-run electricity consumption. However, the gross domestic product and the past value of electricity consumption have a positive effect. Moreover, the causality test reveals a unidirectional relationship between price and electricity consumption. Our empirical findings are effective to policy makers to maintain the electricity consumption in Tunisia by using the appropriate strategy. - Highlights: ► This paper examined the electricity demand in Tunisia in the long-run. ► The empirical analysis revealed that in the long-run the electricity demand is affected by changes in its past value, GDP in constant price and real electricity price. ► There is a unidirectional relationship between price and electricity consumption, that is to say, that the electricity price causes the consumption. ► Those results suggest that a pricing policy can be an effective instrument to rationalize the electricity consumption in Tunisia in the long-run.

  7. 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.

  8. Performance analysis of a combined organic Rankine cycle and vapor compression cycle for power and refrigeration cogeneration

    International Nuclear Information System (INIS)

    Kim, Kyoung Hoon; Perez-Blanco, Horacio

    2015-01-01

    A thermodynamic analysis of cogeneration of power and refrigeration activated by low-grade sensible energy is presented in this work. An organic Rankine cycle (ORC) for power production and a vapor compression cycle (VCC) for refrigeration using the same working fluid are linked in the analysis, including the limiting case of cold production without net electricity production. We investigate the effects of key parameters on system performance such as net power production, refrigeration, and thermal and exergy efficiencies. Characteristic indexes proportional to the cost of heat exchangers or of turbines, such as total number of transfer units (NTU tot ), size parameter (SP) and isentropic volumetric flow ratio (VFR) are also examined. Three important system parameters are selected, namely turbine inlet temperature, turbine inlet pressure, and the flow division ratio. The analysis is conducted for several different working fluids. For a few special cases, isobutane is used for a sensitivity analysis due to its relatively high efficiencies. Our results show that the system has the potential to effectively use low grade thermal sources. System performance depends both on the adopted parameters and working fluid. - Highlights: • Waste heat utilization can reduce emissions of carbon dioxide. • The ORC/VCC cycle can deliver power and/or refrigeration using waste heat. • Efficiencies and size parameters are used for cycle evaluation. • The cycle performance is studied for eight suitable refrigerants. Isobutane is used for a sensitivity analysis. • The work shows that the isobutene cycle is quite promising.

  9. 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.

  10. A feasibility analysis of replacing the standard ammonia refrigeration device with the cascade NH3/CO2 refrigeration device in the food industry

    Directory of Open Access Journals (Sweden)

    Jankovich Dennis

    2015-01-01

    Full Text Available The thermodynamic analysis demonstrates the feasibility of replacing the standard ammonia refrigeration device with the cascade NH3/CO2 refrigeration device in the food industry. The main reason for replacement is to reduce the total amount of ammonia in spaces like deep-freezing chambers, daily chambers, working rooms and technical passageways. An ammonia-contaminated area is hazardous to human health and the safety of food products. Therefore the preferred reduced amount of ammonia is accumulated in the Central Refrigeration Engine Room, where the cascade NH3/CO2 device is installed as well. Furthermore, the analysis discusses and compares two left Carnot¢s refrigeration cycles, one for the standard ammonia device and the other for the cascade NH3/CO2 device. Both cycles are processes with two-stage compression and two-stage throttling. The thermodynamic analysis demonstrates that the selected refrigeration cycle is the most cost-effective process because it provides the best numerical values for the total refrigeration factor with respect to the observed refrigeration cycle. The chief analyzed influential parameters of the cascade device are: total refrigeration load, total reactive power, mean temperature of the heat exchanger, evaporating and condensing temperature of the low-temperature part.

  11. Ecological optimization for generalized irreversible Carnot refrigerators

    International Nuclear Information System (INIS)

    Chen Lingen; Zhu Xiaoqin; Sun Fengrui; Wu Chih

    2005-01-01

    The optimal ecological performance of a Newton's law generalized irreversible Carnot refrigerator with the losses of heat resistance, heat leakage and internal irreversibility is derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the exergy output rate and exergy loss rate (entropy production rate) of the refrigerator. Numerical examples are given to show the effects of heat leakage and internal irreversibility on the optimal performance of generalized irreversible refrigerators

  12. Revamping and Expanding Domestic Electricity Supply. Law draft adopted by the National Assembly; Projet de Loi relatif a la Modernisation et au Developpement du Service Public de l'Electricite adopte par l'Assemblee Nationale

    Energy Technology Data Exchange (ETDEWEB)

    National Assembly [ed.] [Assemblee Nationale, Paris (France)

    1999-03-02

    This document presents the draft of the law regarding the revamping and expanding the domestic electricity supply, adopted by the French National Assembly. The first Title devoted to the definition of the domestic electricity supply contains 5 articles. The second Title deals with the production of electricity in the articles 6 through 12. Title three concerns the transport and electricity distribution issue exposed in articles 13 through 21 and three chapters titled: - Chap. 1, Transport of electricity; - Chap. 2, Distribution of electricity; - Chap.3, Safety and security of the grids. The Title four concerns with the access to domestic electricity grids exposed in the articles 22 to 24. The fifth Title settles in articles 25 to 27 the issue of the dissociation and transparency of accounting. The articles 28 through 41 treat under Title six the problems of Regulation. The Object of Electricity Authority of France is stipulated in the Title seven containing only the article 42. Social issues are stipulated in Title eight containing two articles, the first one being a completion to Chapter III of the Title seven in the Labour Law, titled 'Electricity and Gas Industries'. Finally, the Title nine comprising articles 45 to 52 deals with Diverse and Transient Provisions. The law draft was debated in public session in Paris on 2 March and signed by the President Laurent Fabius.

  13. 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.

  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. 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...

  16. Evaporation of new refrigerants on tubes with improved surfaces; Evaporation de nouveaux refrigerants sur des tubes a surface amelioree

    Energy Technology Data Exchange (ETDEWEB)

    Kattan, N.; Favrat, D.; Thome, J. R.; Nidegger, E.; Zuercher, O. [Ecole Polytechnique Federale, Lab. d` Energetique Industrielle (LENI), Lausanne (Switzerland)

    1995-07-15

    The substitution of old refrigerants in refrigeration systems, heat pumps and organic Rankine cycles for heat recovery, request a good knowledge of heat transfer properties of substitute fluids. The test measurements in LENI test facility (concentric tubes with water flowing in a counter-current flow) with new refrigerants like HFC134a, HCFC123, R-404A, R-402A, have established a new data bank with new refrigerants, a comparison with old refrigerants like CFC11, CFC12 CFC/HCFC502 and with existent correlations. Correlations were programmed to calculate and compare heat transfer coefficient during the tests. To develop a new correlation based on flow regimes, a high speed Sony video tape camera is used to observe and identify flow patterns. Important images are captured, digitalized, stored for later analysis and sent to a color plotter. Several flow pattern maps were programmed and compared to flow regimes observed on the test rig. Local flow boiling heat transfer coefficients were measured for HFC134a and HCFC123 evaporating inside a microfin tube. In addition, microfin heat transfer augmentation relative to plain tube test data was investigated. The presence of oil in the evaporator has an effect on heat transfer coefficient. Local flow boiling heat transfer coefficients were measured for refrigerant HFC134a-oil ester (Mobil EAL Arctic 68). A new thermodynamic approach for modeling mixtures of refrigerants and lubricating oils is developed. A very high accuracy, straight vibrating tube type of density flowmeter is used to measure oil concentrations of flowing HFC134a-oil mixtures. (author) 28 figs., 25 refs.

  17. Efficiency analysis of alternative refrigerants for ejector cooling cycles

    International Nuclear Information System (INIS)

    Gil, Bartosz; Kasperski, Jacek

    2015-01-01

    Highlights: • Advantages of using alternative refrigerants as ejector refrigerants were presumed. • Computer software basing on theoretical model of Huang et al. (1999) was prepared. • Optimal temperature range of primary vapor for each working fluid was calculated. - Abstract: Computer software, basing on the theoretical model of Huang et al. with thermodynamic properties of selected refrigerants, was prepared. Investigation was focused on alternative refrigerants that belong to two groups of substances: common solvents (acetone, benzene, cyclopentane, cyclohexane and toluene) and non-flammable synthetic refrigerants applied in Organic Rankine Cycle (ORC) (R236ea, R236fa, R245ca, R245fa, R365mfc and RC318). Refrigerants were selected to detect a possibility to use them in ejector cooling system powered by a high-temperature heat source. A series of calculations were carried out for the generator temperature between 70 and 200 °C, with assumed temperatures of evaporation 10 °C and condensation 40 °C. Investigation revealed that there is no single refrigerant that ensures efficient operation of the system in the investigated temperature range of primary vapor. Each substance has its own maximum entrainment ratio and COP at its individual temperature of the optimum. The use of non-flammable synthetic refrigerants allows obtaining higher COP in the low primary vapor temperature range. R236fa was the most beneficial among the non-flammable synthetic refrigerants tested. The use of organic solvents can be justified only for high values of motive steam temperature. Among the solvents, the highest values of entrainment ratio and COP throughout the range of motive temperature were noted for cyclopentane. Toluene was found to be an unattractive refrigerant from the ejector cooling point of view

  18. 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.

  19. Controlled environment laboratory for the energy certification of refrigeration and air conditioning systems; Laboratorio de ambiente controlado para la certificacion energetica de sistemas de refrigeracion y aire acondicionado

    Energy Technology Data Exchange (ETDEWEB)

    Ambriz, Juan Jose; Romero Paredes, Hernando; Dorantes, Ruben [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)

    1999-07-01

    In this paper the general characteristics of the Controlled Environment Laboratory (CELAB) are described and some of the possible tests that could be performed in this device to evaluate the energy efficiency in air conditioning systems, domestic refrigeration and industrial refrigeration, as well as tests to evaluate the hydrothermal comfort in national populations, are presented. [Spanish] En este trabajo se describen las caracteristicas generales del Laboratorio de Ambiente Controlado (LAB), y se presentan algunas de las posibles pruebas que podran ser desarrolladas en este dispositivo para evaluar la eficiencia energetica en sistemas de aire acondicionado, refrigeracion domestica y refrigeracion industrial, asi como para pruebas para evaluar el confort hidrotermico en poblaciones nacionales.

  20. Possibility of using adsorption refrigeration unit in district heating network

    Directory of Open Access Journals (Sweden)

    Grzebielec Andrzej

    2015-09-01

    Full Text Available Adsorption refrigeration systems are able to work with heat sources of temperature starting with 50 °C. The aim of the article is to determine whether in terms of technical and economic issues adsorption refrigeration equipment can work as elements that produce cold using hot water from the district heating network. For this purpose, examined was the work of the adsorption air conditioning equipment cooperating with drycooler, and the opportunities offered by the district heating network in Warsaw during the summer. It turns out that the efficiency of the adsorption device from the economic perspective is not sufficient for production of cold even during the transitional period. The main problem is not the low temperature of the water supply, but the large difference between the coefficients of performance, COPs, of adsorption device and a traditional compressor air conditioning unit. When outside air temperature is 25 °C, the COP of the compressor type reaches a value of 4.49, whereas that of the adsorption device in the same conditions is 0.14. The ratio of the COPs is 32. At the same time ratio between the price of 1 kWh of electric power and 1 kWh of heat is only 2.85. Adsorption refrigeration equipment to be able to compete with compressor devices, should feature COPads efficiency to be greater than 1.52. At such a low driving temperature and even changing the drycooler into the evaporative cooler it is not currently possible to achieve.

  1. Classification of refrigerants; Classification des fluides frigorigenes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This document was made from the US standard ANSI/ASHRAE 34 published in 2001 and entitled 'designation and safety classification of refrigerants'. This classification allows to clearly organize in an international way the overall refrigerants used in the world thanks to a codification of the refrigerants in correspondence with their chemical composition. This note explains this codification: prefix, suffixes (hydrocarbons and derived fluids, azeotropic and non-azeotropic mixtures, various organic compounds, non-organic compounds), safety classification (toxicity, flammability, case of mixtures). (J.S.)

  2. Thermodynamic performance analysis of a vapor compression–absorption cascaded refrigeration system

    International Nuclear Information System (INIS)

    Jain, Vaibhav; Kachhwaha, S.S.; Sachdeva, Gulshan

    2013-01-01

    Highlights: • Study includes first and second law analysis with alternatives refrigerants. • Power consumption in cascaded system is 61% less than vapor compression system. • COP of compression system is improved by 155% with cascaded absorption system. • Condenser is more sensitive to external fluid temperature as compare to evaporator. - Abstract: In the present study, a thermodynamic model for cascaded vapor compression–absorption system (CVCAS) has been developed which consists of a vapor compression refrigeration system (VCRS) coupled with single effect vapor absorption refrigeration system (VARS). Based on first and second laws, a comparative performance analysis of CVCAS and an independent VCRS has been carried out for a design capacity of 66.67 kW. The results show that the electric power consumption in CVCAS is reduced by 61% and COP of compression section is improved by 155% with respect to the corresponding values pertaining to a conventional VCRS. However there is a trade-off between these parameters and the rational efficiency which is found to decrease to half of that for a VCRS. The effect of various operating parameters, i.e., superheating, subcooling, cooling capacity, inlet temperature and the product of effectiveness and heat capacitance of external fluids are extensively studied on the COP, total irreversibility and rational efficiency of the CVCAS. Besides, the performance of environment friendly refrigerants such as R410A, R407C and R134A is found to be almost at par with that of R22. Hence, all the alternative refrigerants selected herein can serve as potential substitutes for R22. Furthermore, it has been found that reducing the irreversibility rate of the condenser by one unit due to decrease in condenser temperature depicted approximately 3.8 times greater reduction in the total irreversibility rate of the CVCAS, whereas unit reduction in the evaporator’s irreversibility rate due to increase in evaporator temperature reduced

  3. Optimizing the Thermoacoustic Pulse Tube Refrigerator Performances

    Directory of Open Access Journals (Sweden)

    E. V. Blagin

    2014-01-01

    Full Text Available The article deals with research and optimization of the thermoacoustic pulse tube refrigerator to reach a cryogenic temperature level. The refrigerator is considered as a thermoacoustic converter based on the modified Stirling cycle with helium working fluid. A sound pressure generator runs as a compressor. Plant model comprises an inner heat exchanger, a regenerative heat exchanger, a pulse tube, hot and cold heat exchangers at its ends, an inertial tube with the throttle, and a reservoir. A model to calculate the pulse tube thermoacoustic refrigerator using the DeltaEC software package has been developed to be a basis for calculation techniques of the pulse tube refrigerator. Momentum, continuity, and energy equations for helium refrigerant are solved according to calculation algorithm taking into account the porosity of regenerator and heat exchangers. Optimization of the main geometric parameters resulted in decreasing temperature of cold heat exchanger by 41,7 K. After optimization this value became equal to 115,01 K. The following parameters have been optimized: diameters of the feeding and pulse tube and heat exchangers, regenerator, lengths of the regenerator and pulse and inertial tubes, as well as initial pressure. Besides, global minimum of temperatures has been searched at a point of local minima corresponding to the optimal values of abovementioned parameters. A global-local minima difference is 0,1%. Optimized geometric and working parameters of the thermoacoustic pulse tube refrigerator are presented.

  4. Computer modeling of commercial refrigerated warehouse facilities

    International Nuclear Information System (INIS)

    Nicoulin, C.V.; Jacobs, P.C.; Tory, S.

    1997-01-01

    The use of computer models to simulate the energy performance of large commercial refrigeration systems typically found in food processing facilities is an area of engineering practice that has seen little development to date. Current techniques employed in predicting energy consumption by such systems have focused on temperature bin methods of analysis. Existing simulation tools such as DOE2 are designed to model commercial buildings and grocery store refrigeration systems. The HVAC and Refrigeration system performance models in these simulations tools model equipment common to commercial buildings and groceries, and respond to energy-efficiency measures likely to be applied to these building types. The applicability of traditional building energy simulation tools to model refrigerated warehouse performance and analyze energy-saving options is limited. The paper will present the results of modeling work undertaken to evaluate energy savings resulting from incentives offered by a California utility to its Refrigerated Warehouse Program participants. The TRNSYS general-purpose transient simulation model was used to predict facility performance and estimate program savings. Custom TRNSYS components were developed to address modeling issues specific to refrigerated warehouse systems, including warehouse loading door infiltration calculations, an evaporator model, single-state and multi-stage compressor models, evaporative condenser models, and defrost energy requirements. The main focus of the paper will be on the modeling approach. The results from the computer simulations, along with overall program impact evaluation results, will also be presented

  5. New possibilities for non-CFC refrigeration

    International Nuclear Information System (INIS)

    Lorentzen, G.; Pettersen, J.

    1992-01-01

    There is a widespread belief that the only viable refrigerants in most applications are new fluorocarbon chemicals. This trend will eventually result in emissions of several hundred thousand tons of new chemicals to the atmosphere each year, involving potential risk of unforeseen environmental effects. A number of other options exist, or may be developed. By using substances which already have a natural role in our ecosystems, some uncertainty related to the critical issue of our future environment can be avoided. By development and practical testing of a laboratory prototype it has been documented that carbon dioxide is a viable refrigerant in automobile air conditioners, completely solving all environmental problems associated with such systems. General use of CO 2 as a refrigerant may provide a number of advantages in the present situation, both from an environmental and practical point of view. It is our considered opinion that the old carbon dioxide offers a key to the complete solution of the environmental problems in many areas of refrigeration usage. 19 refs., 8 figs., 5 tabs

  6. Reduction of the waste from domestic production of the orange

    International Nuclear Information System (INIS)

    Husain, K. A. M.

    2010-10-01

    The research subject is (reduction of the waste from domestic production of orange) we find there is a lot of wastage after harvest, because the process of packaging, loading, transportation, and store is not adequate. The purpose of this research is to solve this problem of wastage by following a number of steps after harvesting and pre-harvest process. This process is called COLD CHAIN. Cold chain is: cold store in production place, cold vehicles for transportation, cold room in the market, cold car for distribution, cold and freezer refrigerator home. After adopting the cold chain we achieved the following results: orange wastage is reduced, the orange quality improved. (Author)

  7. Feasibility study of wind-generated electricity for rural applications in southwestern Ohio

    Science.gov (United States)

    Kohring, G. W.

    The parameters associated with domestic production of wind generated electricity for direct use by small farms and rural homes in the southwestern Ohio region are discussed. The project involves direct utility interfaced electricity generation from a horizontal axis, down-wind, fixed pitch, wind powered induction generator system. Goals of the project are to determine: the ability to produce useful amounts of domestic wind generated electricity in the southwestern Ohio region; economic justification for domestic wind generated electrical production; and the potential of domestic wind generated electricity for reducing dependence on non-renewable energy resources in the southwestern Ohio region.

  8. 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...... in the supermarket. The first approach to solve this problem is to design an overall control system which coordinates the compressor capacity and the current refrigeration load. The drawback of this approach is the complexity of the single controller. The solution is investigated in the first part of the report...

  9. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere, mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel. We find that implementing HFC refrigerant transition and energy efficiency improvement policies in parallel for room air conditioning, roughly doubles the benefit of either policy implemented separately. We estimate that shifting the 2030 world stock of room air conditioners from the low efficiency technology using high-GWP refrigerants to higher efficiency technology and low-GWP refrigerants in parallel would save between 340-790 gigawatts (GW) of peak load globally, which is roughly equivalent to avoiding 680-1550 peak power plants of 500MW each. This would save 0.85 GT/year annually in China equivalent to over 8 Three Gorges dams and over 0.32 GT/year annually in India equivalent to roughly twice India’s 100GW solar mission target. While there is some uncertainty associated with

  10. Design feasibility of an intermittent domestic energy store

    Energy Technology Data Exchange (ETDEWEB)

    Tahat, M.A. [Jordan Univ. of Sceince and Technology, Irbid (Jordan). Dept. of Mechanical Engineering; Babus`Haq, R.F.; O`Callaghan, P.W.; Probert, S.D. [Cranfield Univ., Bedford (United Kingdom). Dept. of Applied Energy

    1995-09-01

    In recent years, energy storage has been recognised as a potentially significant means by which primary energy consumption can be reduced in domestic, commercial and industrial processes. An intermittent domestic thermochemical heat pump, with a 5 kW{sub e} electric power output when employed as an energy store, is proposed. Different design options have been considered and their economic feasibilities evaluated. (author)

  11. Energy efficient refrigeration and flexible power consumption in a smart grid

    Energy Technology Data Exchange (ETDEWEB)

    Gybel Hovgaard, T.; Larsen, Lars F.S. (Danfoss Refrigeration and A/C Controls, Nordborg (Denmark)); Halvgaard, R.; Bagterp Joergensen, J. (Technical Univ. of Denmark (DTU). DTU Informatics, Kgs. Lyngby (Denmark))

    2011-05-15

    Refrigeration and heating systems consume substantial amounts of energy worldwide. However, due to the thermal capacity there is a potential for storing 'coldness' or heat in the system. This feature allows for implementation of different load shifting and shedding strategies in order to optimize the operation energywise, but without compromising the original cooling and indoor climate quality. In this work we investigate the potential of such a strategy and its ability to significantly lower the cost related to operating systems such as supermarket refrigeration and heat pumps for residential houses. With modern Economic Model Predictive Control (MPC) methods we make use of weather forecasts and predictions of varying electricity prices to apply more load to the system when the thermodynamic cycle is most efficient, and to consume larger shares of the electricity when the demand and thereby the prices are low. The ability to adjust power consumption according to the demands on the power grid is a highly wanted feature in a future Smart Grid. Efficient utilization of greater amounts of renewable energy calls for solutions to control the power consumption such that it increases when an energy surplus is available and decreases when there is a shortage. This should happen almost instantly to accommodate intermittent energy sources as e.g. wind turbines. We expect our power management solution to render systems with thermal storage capabilities suitable for flexible power consumption. The aggregation of several units will contribute significantly to the shedding of total electricity demand. Using small case studies we demonstrate the potential for utilizing daily variations to deliver a power efficient cooling or heating and for the implementation of Virtual Power Plants in Smart Grid scenarios. (Author)

  12. RESEARCH OF REFRIGERATION SYSTEMS FAILURES IN POLISH FISHING VESSELS

    Directory of Open Access Journals (Sweden)

    Waldemar KOSTRZEWA

    2013-07-01

    Full Text Available Temperature is a basic climatic parameter deciding about the quality change of fishing products. Time, after which qualitative changes of caught fish don’t exceed established, acceptable range, is above all the temperature function. Temperature reduction by refrigeration system of the cargo hold is a basic technical method, which allows extend transport time. Failures of refrigeration systems in fishing vessels have a negative impact on the environment in relation to harmful refrigerants emission. The paper presents the statistical analysis of failures occurred in the refrigeration systems of Polish fishing vessels in 2007‐2011 years. Analysis results described in the paper can be a base to draw up guidelines, both for designers as well as operators of the marine refrigeration systems.

  13. Leaktightness of the plant is enviromental protection. Reduction of CFC emissions from refrigeration systems and equipment during operation, maintenance, and disposal. Anlagendichtheit ist Umweltschonung. Verringerung der FCKW-Emissionen aus kaeltetechnischen Anlagen und Geraeten bei Betrieb, Wartung und Entsorgung

    Energy Technology Data Exchange (ETDEWEB)

    Lotz, H

    1991-02-01

    As from 1993, the European domestic market requires a unique standardization for the field of the European Community, especially in the field of refrigeration. In this area, an information about the status (middle of 1990) of the CEN standardization is given. The following subjects are discussed: (1) Density of refrigerating devices and plants: Proper design, specifications for pressure safety and safety facilities, proper design, specifications for the density of devices, pipelines, values and connections, identification, documentation as well as maintenance and repair; sanitation: Technology of sanitation and transportation. (BWI).

  14. Prediction of thermophysical properties of mixed refrigerants using artificial neural network

    International Nuclear Information System (INIS)

    Sencan, Arzu; Koese, Ismail Ilke; Selbas, Resat

    2011-01-01

    The determination of thermophysical properties of the refrigerants is very important for thermodynamic analysis of vapor compression refrigeration systems. In this paper, an artificial neural network (ANN) is proposed to determine properties as heat conduction coefficient, dynamic viscosity, kinematic viscosity, thermal diffusivity, density, specific heat capacity of refrigerants. Five alternative refrigerants are considered: R413A, R417A, R422A, R422D and R423A. The training and validation were performed with good accuracy. The thermophysical properties of the refrigerants are formulated using artificial neural network (ANN) methodology. Liquid and vapor thermophysical properties of refrigerants with new formulation obtained from ANN can be easily estimated. The method proposed offers more flexibility and therefore thermodynamic analysis of vapor compression refrigeration systems is fairly simplified.

  15. Condensation of nano-refrigerant inside a horizontal tube

    Science.gov (United States)

    Darzi, Milad; Sadoughi, M. K.; Sheikholeslami, M.

    2018-05-01

    In this paper, condensing pressure drop of refrigerant-based nanofluid inside a tube is studied. Isobutene was selected as the base fluid while CuO nanoparticles were utilized to prepare nano-refrigerant. However, for the feasibility of nanoparticle dispersion into the refrigerant, Polyester oil (POE) was utilized as lubricant oil and added to the pure refrigerant by 1% mass fraction. Various values of mass flux, vapor quality, concentration of nanoparticle are investigated. Results indicate that adding nanoparticles leads to enhance frictional pressure drop. Nanoparticles caused larger pressure drop penalty at relatively lower vapor qualities which may be attributed to the existing condensation flow pattern such that annular flow is less influenced by nanoparticles compared to intermittent flow regime.

  16. Simulated performance of biomass gasification based combined power and refrigeration plant for community scale application

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S., E-mail: suman.mech09@gmail.com [Department of Mechanical Engineering, NIT, Agarpara, Kolkata – 700109, West Bengal (India); Mondal, P., E-mail: mondal.pradip87@gmail.com; Ghosh, S., E-mail: sudipghosh.becollege@gmail.com [Department of Mechanical Engineering, IIEST, Shibpur, Howrah – 711103, West Bengal (India)

    2016-07-12

    Thermal performance analysis and sizing of a biomass gasification based combined power and refrigeration plant (CPR) is reported in this study. The plant is capable of producing 100 kWe of electrical output while simultaneously producing a refrigeration effect, varying from 28-68 ton of refrigeration (TR). The topping gas turbine cycle is an indirectly heated all-air cycle. A combustor heat exchanger duplex (CHX) unit burns producer gas and transfer heat to air. This arrangement avoids complex gas cleaning requirements for the biomass-derived producer gas. The exhaust air of the topping GT is utilized to run a bottoming ammonia absorption refrigeration (AAR) cycle via a heat recovery steam generator (HRSG), steam produced in the HRSG supplying heat to the generator of the refrigeration cycle. Effects of major operating parameters like topping cycle pressure ratio (r{sub p}) and turbine inlet temperature (TIT) on the energetic performance of the plant are studied. Energetic performance of the plant is evaluated via energy efficiency, required biomass consumption and fuel energy savings ratio (FESR). The FESR calculation method is significant for indicating the savings in fuel of a combined power and process heat plant instead of separate plants for power and process heat. The study reveals that, topping cycle attains maximum power efficiency of 30%in pressure ratio range of 8-10. Up to a certain value of pressure ratio the required air flow rate through the GT unit decreases with increase in pressure ratio and then increases with further increase in pressure ratio. The capacity of refrigeration of the AAR unit initially decreases up to a certain value of topping GT cycle pressure ratio and then increases with further increase in pressure ratio. The FESR is found to be maximized at a pressure ratio of 9 (when TIT=1100°C), the maximum value being 53%. The FESR is higher for higher TIT. The heat exchanger sizing is also influenced by the topping cycle pressure ratio

  17. Performance of a Throttle Cycle Refrigerator with Nitrogen-Hydrocarbon and Argon-Hydrocarbon Mixtures

    Science.gov (United States)

    Venkatarathnam, G.; Senthil Kumar, P.; Srinivasa Murthy, S.

    2004-06-01

    Throttle cycle refrigerators are a class of vapor compression refrigerators that can provide refrigeration at cryogenic temperatures and operate with refrigerant mixtures. The performance of our prototype refrigerators with nitrogen-hydrocarbon, nitrogen-hydrocarbon-helium and argon-hydrocarbon refrigerant mixtures is presented in this paper.

  18. 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.

  19. 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.

  20. Development of the Optimum Operation Scheduling Model of Domestic Electric Appliances for the Supply-Demand Adjustment in a Power System

    Science.gov (United States)

    Ikegami, Takashi; Iwafune, Yumiko; Ogimoto, Kazuhiko

    The high penetration of variable renewable generation such as Photovoltaic (PV) systems will cause the issue of supply-demand imbalance in a whole power system. The activation of the residential power usage, storage and generation by sophisticated scheduling and control using the Home Energy Management System (HEMS) will be needed to balance power supply and demand in the near future. In order to evaluate the applicability of the HEMS as a distributed controller for local and system-wide supply-demand balances, we developed an optimum operation scheduling model of domestic electric appliances using the mixed integer linear programming. Applying this model to several houses with dynamic electricity prices reflecting the power balance of the total power system, it was found that the adequate changes in electricity prices bring about the shift of residential power usages to control the amount of the reverse power flow due to excess PV generation.

  1. Thermodynamic investigation of a booster-assisted ejector refrigeration system

    International Nuclear Information System (INIS)

    Zhao, Hongxia; Zhang, Ke; Wang, Lei; Han, Jitian

    2016-01-01

    Highlights: • COP based on thermal input increases with booster outlet pressure. • Both entrainment ratio and area ratio increase with booster outlet pressure. • COP based on work is larger than compressor-based refrigeration system. • An optimum booster outlet pressure obtains maximum COP based on work. • Exergy destruction occurs mainly in ejector, condenser, evaporator and generator. - Abstract: In order to improve performance of ejector refrigeration system, a booster is added before an ejector to enhance secondary flow pressure, which is called a booster assisted refrigeration system. Based on mass, momentum and energy conservation, a 1D model of ejector for optimal performance prediction was presented and validated with experimental data. A detailed study of working characteristics of the booster assisted ejector refrigeration system was carried out and compared against conventional ejector refrigeration system and compressor based refrigeration system, on the basis of first and second laws of thermodynamics. Effects of booster outlet pressure on COP_t_h based on thermal energy and COP_w based on work input, and also on entrainment ratio and area ratio of ejector were studied. The exergy destruction rates were also computed and analyzed for components of the booster-assisted ejector refrigeration system. Ways to reduce exergy destruction were discussed.

  2. Theoretical research on the performance of the transcritical ejector refrigeration cycle with various refrigerants

    International Nuclear Information System (INIS)

    Wang, F.; Li, D.Y.; Zhou, Y.

    2015-01-01

    The transcritical ejector refrigeration cycle (TERC), which has shown an attractive alternative to the ejector refrigeration systems, can better match large variable-temperature heat sources and yields higher COP. In this paper, in order to find a proper working fluid for the TERC, the performance of the TERC with CO_2 and various working fluids with low critical temperatures including R1270, R32, R143a, R125 and R115 are studied and compared. A thermodynamic model for ejector is set up to simulate the ejector by introducing the real properties of refrigerants. The results indicate that R1270 has the highest COP at the same heat source condition and medium working pressures, and is one of environment-friendly working fluids, hence R1270 is the most proper one. The COP of the transcritical cycle is higher than that of the subcritical cycle, and The effective performance coefficient COP_m of the transcritical cycle is also better. When the heater outlet temperature is increased, its system COP_m improves, but its system COP almost does not change. - Highlights: • A thermodynamic model is used to simulate the ejector with real properties. • The performance of the TERC with various refrigerants is compared. • The environment-friendly working fluid of R1270 shows the most proper one. • The COP of the transcritical cycle is higher than that of the subcritical cycle.

  3. The market for absorption refrigeration in Spain; Der Markt fuer Absorptionskaeltetechnik in Spanien

    Energy Technology Data Exchange (ETDEWEB)

    Paramo, M. [Enagas, Madrid (Spain)

    1996-12-31

    Due to the Spanish climate (hot summers throughout large parts of the country) the household and small consumers sector in this country has a substantial requirement for cold production. Today most industrial and commercial buildings here such as office blocks, shopping centres, hospitals, hotel etc. are equipped with air conditioning plants. Usually these are based on compression refrigeration plants. Beyond this air conditioning plants are now also beginning to become popular in one-family houses and flats, especially in southern and western Spain and along the Mediterranean coast. In most cases these plants, too, work with compression refrigeration, though it is not uncommon to find steam-based refrigeration systems. Both these types of system are driven by electricity. In the industrial sector, too, the market for refrigeration shows a very wide spectrum across a large variety of branches. (orig./HW) [Deutsch] In Spaniens HuK-Sektor (Haushalte und Kleinverbraucher) besteht aufgrund der herrschenden klimatischen Bedingungen (sehr warme Sommer in weiten Teilen des Landes) ein erheblicher Bedarf an der Erzeugung von Kaelte. Die meisten Industrie- und gewerblichen Gebaeude, wie Buerokomplexe, Einkaufszentren, Krankenhaeuser, Hotels, usw. sind mittlerweile mit Klimaanlagen ausgeruestet. Im allgemeinen handelt es sich hierbei um Kompressionskaelteanlagen. Vornehmlich in Sued- und Zentralspanien sowie an der Mittelmeerkueste haben Klimaanlagen inzwischen aber auch verstaerkt in Einfamilienhaeusern und Wohnungen Einzug gehalten. Vorwiegend sind Kompressionskaelteanlagen im Einsatz; haeufig sind aber auch Systeme anzutreffen, die auf Wasserdampfbasis arbeiten. Energietraeger ist bei beiden Systemen Strom. Der Markt fuer Kaelteerzeugung ist auch im industriellen Bereich sehr breitgefaechert und umfasst eine Vielzahl von Branchen. Der Loewenanteil entfaellt jedoch auf die Nahrungsmittelindustrie. (orig./HW)

  4. Refrigeration plants for the SSCL

    International Nuclear Information System (INIS)

    McAshan, M.; Ganni, V.; Than, R.; Niehaus, T.

    1991-03-01

    The basic requirements and operating features of the collider cryogenic system have already been described in other publications. The general arrangement of the refrigeration plant and its subsystems is presented, and the issue of how to provide redundancy in the cryogenic system is addressed, and some of the basic features of the refrigeration plants are described. The collider cryogenic system design is not final yet, and this report only reflects the direction and current status of the cryogenic system design

  5. 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

  6. Cryogen-free dilution refrigerators

    International Nuclear Information System (INIS)

    Uhlig, K

    2012-01-01

    We review briefly our first cryogen-free dilution refrigerator (CF-DR) which was precooled by a GM cryocooler. We then show how today's dry DRs with pulse tube precooling have developed. A few examples of commercial DRs are explained and noteworthy features pointed out. Thereby we describe the general advantages of cryogen-free DRs, but also show where improvements are still desirable. At present, our dry DR has a base temperature of 10 mK and a cooling capacity of 700 μW at a mixing chamber temperature of 100 mK. In our cryostat, in most recent work, an additional refrigeration loop was added to the dilution circuit. This 4 He circuit has a lowest temperature of about 1 K and a refrigeration capacity of up to 100 mW at temperatures slightly above 1 K; the dilution circuit and the 4 He circuit can be run separately or together. The purpose of this additional loop is to increase the cooling capacity for experiments where the cooling power of the still of the DR is not sufficient to cool cold amplifiers and cables, e.g. in studies on superconducting quantum circuits or astrophysical applications.

  7. Cryogen-free dilution refrigerators

    Science.gov (United States)

    Uhlig, K.

    2012-12-01

    We review briefly our first cryogen-free dilution refrigerator (CF-DR) which was precooled by a GM cryocooler. We then show how today's dry DRs with pulse tube precooling have developed. A few examples of commercial DRs are explained and noteworthy features pointed out. Thereby we describe the general advantages of cryogen-free DRs, but also show where improvements are still desirable. At present, our dry DR has a base temperature of 10 mK and a cooling capacity of 700 μW at a mixing chamber temperature of 100 mK. In our cryostat, in most recent work, an additional refrigeration loop was added to the dilution circuit. This 4He circuit has a lowest temperature of about 1 K and a refrigeration capacity of up to 100 mW at temperatures slightly above 1 K; the dilution circuit and the 4He circuit can be run separately or together. The purpose of this additional loop is to increase the cooling capacity for experiments where the cooling power of the still of the DR is not sufficient to cool cold amplifiers and cables, e.g. in studies on superconducting quantum circuits or astrophysical applications.

  8. [Continuous improvement of portable domestic pelvic floor neuromuscular electrical stimulation on the pelvic floor function of patients with urinary incontinence].

    Science.gov (United States)

    Sun, Zhijing; Zhu, Lan; Lang, Jinghe; Wang, Wei; Shi, Honghui; Pang, Hongxia; Shi, Xinwen

    2015-12-01

    To evaluate continuous improvement of portable domestic pelvic floor neuromuscular electrical stimulation on the pelvic floor function of patients with stress urinary incontinence after short-term pelvic floor electrophysiological treatment in hospital. Totally 60 women with stress urinary incontinence were recruited for this randomized controlled trial. The control group including a total of 30 patients, only received 4 weeks pelvic floor electrophysiological treatment in the hospital. Family consolidation treatment group (experimental group) including 30 patients, after 4-week treatment in hospital, received 12-week of pelvic floor neuromuscular electrical stimulation using portable electrical stimulator at home under the guidance of doctors. In post-treatment 6 months and 9 months, 1-hour pad test was measured for urine leakage, pelvic floor electrical physiological parameters were assessed, and subjective improvement of symptoms of urinary incontinence were evaluated. All these data were analysed to compare the effect of the two groups. In 9 months after treatment, average change of urine leakage, the control group and experiment group were (75±24)% versus (99±3)%, the difference was statistically significant (Pcontinuous improvement of pelvic floor function.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sezgen, O.; Koomey, J.G.

    1995-12-01

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

  10. 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.

  11. Magnetic refrigeration--towards room-temperature applications

    International Nuclear Information System (INIS)

    Brueck, E.; Tegus, O.; Li, X.W.; Boer, F.R. de; Buschow, K.H.J.

    2003-01-01

    Modern society relies very much on readily available cooling. Magnetic refrigeration based on the magneto-caloric effect (MCE) has become a promising competitive technology for the conventional gas-compression/expansion technique in use today. Recently, there have been two breakthroughs in magnetic-refrigeration research: one is that American scientists demonstrated the world's first room-temperature, permanent-magnet, magnetic refrigerator; the other one is that we discovered a new class of magnetic refrigerant materials for room-temperature applications. The new materials are manganese-iron-phosphorus-arsenic (MnFe(P,As)) compounds. This new material has important advantages over existing magnetic coolants: it exhibits a huge MCE, which is larger than that of Gd metal; and its operating temperature can be tuned from about 150 to about 335 K by adjusting the P/As ratio. Here we report on further improvement of the materials by increasing the Mn content. The large entropy change is attributed to a field-induced first-order phase transition enhancing the effect of the applied magnetic field. Addition of Mn reduces the thermal hysteresis, which is intrinsic to the first-order transition. This implies that already moderate applied magnetic fields of below 2 T may suffice

  12. Feasibility study of a refrigeration system powered by natural gas; Estudo de viabilidade de um sistema de refrigeracao acionado a gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Costa Filho, Manoel Antonio da Fonseca [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Faculdade de Engenharia; Biruel Filho, Jose [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    This paper presents a technical, financial and environmental feasibility study, and market analysis, of a 50-TR chiller with vapor compression (mechanical) cycle powered by internal combustion engine. This type of equipment allows natural gas usage for medium-and-low-capacity refrigeration applications, for which there are not competitive commercial equipment based on absorption refrigeration cycle. The technical feasibility is not questionable because it is the association of two remarkably mature technologies and also because such equipment are common in Europe and USA. The natural gas powered equipment operation costs are lower than electricity powered ones, due to lower energy cost, while acquisition, installation and maintenance costs show the opposite. The Net Present Value is positive. The financial feasibility depends directly on the combination of prices of natural gas and electricity, as well as equipment energy efficiencies. The environmental analysis points to the use of electric-driven equipment, which avoids urban area emissions, reinforced by the hydroelectric generation, renewable, used in Brazil. This study had financial support from PETROBRAS/RedeGasEnergia. (author)

  13. Contribution to magnetic refrigeration study at liquid helium study

    International Nuclear Information System (INIS)

    Lacaze, A.

    1985-10-01

    An experimental prototype of magnetic refrigerator operates, following a Carnot cycle, with gallium gadolinium garnet, from liquid helium at 4.2 0 K. Analysis of the cyle and heat exchanges allowed to improve performance up to get more than 50% of Carnot yield at 1.8 0 K and nearly 80% at 2.1 0 K. Operation conditions of a regenerator refrigerator between 4 and 20 0 K are studied. The association of a magnetic refrigerator and a gas refrigerator is analyzed. Among different ways to realize the magnetic stage, an active regenerator cycle is chosen. An experimental device is described [fr

  14. Analysis of a combined Rankine-vapour-compression refrigeration cycle

    International Nuclear Information System (INIS)

    Aphornratana, Satha; Sriveerakul, Thanarath

    2010-01-01

    This paper describes a theoretical analysis of a heat-powered refrigeration cycle, a combined Rankine-vapour-compression refrigeration cycle. This refrigeration cycle combines an Organic Rankine Cycle and a vapour-compression cycle. The cycle can be powered by low grade thermal energy as low as 60 deg. C and can produce cooling temperature as low as -10 deg. C. In the analysis, two combined Rankine-vapour-compression refrigeration cycles were investigated: the system with R22 and the system with R134a. Calculated COP values between 0.1 and 0.6 of both the systems were found.

  15. Food Safety Practices Linked with Proper Refrigerator Temperatures in Retail Delis.

    Science.gov (United States)

    Brown, Laura G; Hoover, Edward Rickamer; Faw, Brenda V; Hedeen, Nicole K; Nicholas, David; Wong, Melissa R; Shepherd, Craig; Gallagher, Daniel L; Kause, Janell R

    2018-05-01

    Listeria monocytogenes (L. monocytogenes) causes the third highest number of foodborne illness deaths annually. L. monocytogenes contamination of sliced deli meats at the retail level is a significant contributing factor to L. monocytogenes illness. The Centers for Disease Control and Prevention's Environmental Health Specialists Network (EHS-Net) conducted a study to learn more about retail delis' practices concerning L. monocytogenes growth and cross-contamination prevention. This article presents data from this study on the frequency with which retail deli refrigerator temperatures exceed 41°F, the Food and Drug Administration (FDA)-recommended maximum temperature for ready-to-eat food requiring time and temperature control for safety (TCS) (such as retail deli meat). This provision was designed to control bacterial growth in TCS foods. This article also presents data on deli and staff characteristics related to the frequency with which retail delis refrigerator temperatures exceed 41°F. Data from observations of 445 refrigerators in 245 delis showed that in 17.1% of delis, at least one refrigerator was >41°F. We also found that refrigeration temperatures reported in this study were lower than those reported in a related 2007 study. Delis with more than one refrigerator, that lacked refrigerator temperature recording, and had a manager who had never been food safety certified had greater odds of having a refrigerator temperature >41°F. The data from this study suggest that retail temperature control is improving over time. They also identify a food safety gap: some delis have refrigerator temperatures that exceed 41°F. We also found that two food safety interventions were related to better refrigerated storage practices: kitchen manager certification and recording refrigerated storage temperatures. Regulatory food safety programs and the retail industry may wish to consider encouraging or requiring kitchen manager certification and recording refrigerated

  16. Applications of magnetic refrigeration and its assessment. A feasibility study - Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-04-15

    Magnetic refrigeration has the potential to replace conventional refrigeration systems - with often problematic refrigerants - in several niche markets or even some main markets of the refrigeration domain. Based on this insight the Swiss Federal Office of Energy has asked a division of the University of Applied Sciences of Western Switzerland (HEIG-VD) in Yverdon-les-Bains to list all possible refrigeration technologies and to evaluate the potential of magnetic refrigeration for these specific applications. The HEIG-VD researchers have developed a calculation tool to determine the coefficient of performance (COP) value and the exergy efficiency as a function of the magnetic field strength and the rotation frequency of a rotary type of magnetic refrigerator. The considered machine design is based on a patent, which was deposited by these scientists. Based on this work, it is found that especially two applications are very interesting for a closer investigation: the household refrigerator without a freezing compartment and the central chilling unit, which may be of large size. In the domains of refrigeration, where magnetic refrigeration could be successfully applied, the costs for magnetic refrigeration machines would be a little higher than those of the conventional ones. On the other hand the study shows possibilities how the magnetic refrigeration machines could reach higher COP values than those of the corresponding gas compression/expansion machines. Therefore, for magnetic refrigeration one may assume lower costs of operation. For large systems - as e.g. chiller units - it should be studied, if superconducting magnets could be economically applied. (author)

  17. Electricity use and load management in electricity heated one-family houses from customer and utility perspective; Effekten av effekten - Elanvaendning och laststyrning i elvaermda smaahus ur kund- och foeretagsperspektiv

    Energy Technology Data Exchange (ETDEWEB)

    Sernhed, Kerstin

    2004-11-01

    Until recently, the increase in electricity demand and peak power demand has been met by expansion of the electricity production. Today, due to the deregulation of the electricity market, the production capacity is decreasing. Therefore, there is a national interest in finding solutions to peak problems also on the demand side. In the studies described here (Study 1 and 2) ten households in electrically heated houses were examined. In 1999 the utility equipped their customers with a remote metering system (CustCom) that has an in-built load control component. In Study 1, the load pattern of ten households was examined by using energy diaries combined with frequent meter readings (every five minutes) of the load demand for heating, hot water service and domestic electricity use. Household members kept energy diaries over a four-day period in January 2004, noting time, activities and the use of household appliances that run on electricity. The analysis showed that the use of heat-producing household appliances, e.g. sauna, washing machine and dryer, appliances used for cooking, dishwasher and extra electric heaters, contribute to the household's highest peaks. Turning on the sauna and at the same time using the shower equates to a peak load of 7-9 kW. This, in addition to the use of electricity for heating and lighting along alongside electricity use for refrigerators and freezers, results in some households reaching their main fuse level (roughly 13,8 kW for a main fuse of 20 A). This means that the domestic use of electricity makes up a considerable part of the highest peak loads in a household, but the highest peaks occur together with the use of electricity for heating and hot water. In the second study, Study 2, the households participated in a load control experiment, in which the utility was able to turn on and switch off the heating and hot water systems remotely, using the CustCom system. Heating and water heaters were switched off for periods of 1

  18. 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

  19. 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.

  20. Data mining techniques for thermophysical properties of refrigerants

    International Nuclear Information System (INIS)

    Kuecueksille, Ecir Ugur; Selbas, Resat; Sencan, Arzu

    2009-01-01

    This study presents ten modeling techniques within data mining process for the prediction of thermophysical properties of refrigerants (R134a, R404a, R407c and R410a). These are linear regression (LR), multi layer perception (MLP), pace regression (PR), simple linear regression (SLR), sequential minimal optimization (SMO), KStar, additive regression (AR), M5 model tree, decision table (DT), M5'Rules models. Relations depending on temperature and pressure were carried out for the determination of thermophysical properties as the specific heat capacity, viscosity, heat conduction coefficient, density of the refrigerants. Obtained model results for every refrigerant were compared and the best model was investigated. Results indicate that use of derived formulations from these techniques will facilitate design and optimize of heat exchangers which is component of especially vapor compression refrigeration system

  1. Thermoelectric Devices: Solid-State Refrigerators and Electrical Generators in the Classroom

    Science.gov (United States)

    Winder, Edmund J.; Ellis, Arthur B.; Lisensky, George C.

    1996-10-01

    Thermoelectric devices are solid-state devices that convert thermal energy from a temperature gradient into electrical energy (the Seebeck effect) or convert electrical energy into a temperature gradient (the Peltier effect). The first application is used most notably in spacecraft power generation systems (for example, in Voyager I and II) and in thermocouples for temperature measurement, while the second application is largely used in specialized cooling applications. Both applications can be demonstrated in the lecture hall to illustrate thermodynamic principles in a compelling manner. They also provide insight into the workings of a high-tech system that is achieving more widespread consumer use. The most visible consumer use of thermoelectric devices utilizing the Peltier effect is in portable electric food coolers/warmers that plug into an automobile cigarette lighter. Conventional cooling systems such as those used in refrigerators utilize a compressor and a working fluid to transfer heat. Thermal energy is absorbed and released as the working fluid undergoes expansion and compression and changes phase from liquid to vapor and back, respectively (1). Semiconductor thermoelectric coolers (also known as Peltier coolers) offer several advantages over conventional systems. They are entirely solid-state devices, with no moving parts; this makes them rugged, reliable, and quiet. They use no ozone-depleting chlorofluorocarbons, potentially offering a more environmentally responsible alternative to conventional refrigeration. They can be extremely compact, much more so than compressor-based systems. Precise temperature control (screws have to be removed to access the thermoelectric module. The module comes equipped with finned aluminum heat sinks attached to both sides; one of these has to be detached in order to remove the module from the lid. The heat sink is then reattached to the module, as shown in Figure 1. Figure 1. Thermoelectric module with attached heat

  2. 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...

  3. 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.

  4. Water, a Refrigerant (L`eau, un Frigorigène)

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    In the light of the ongoing discussions about the availability and the future of synthetic or natural refrigerants "water" is the most attractive fluid for chillers and icemakers because of the low energy demand, the intrinsic safety and the low costs both for the fluid itself and for the install......In the light of the ongoing discussions about the availability and the future of synthetic or natural refrigerants "water" is the most attractive fluid for chillers and icemakers because of the low energy demand, the intrinsic safety and the low costs both for the fluid itself...... since many years any refrigerant with OPD and GWP, Denmark has put up a law in 2001 which includes hefty taxes on HFC. This tax is added to the price of refrigerants and lies between 17 and 44 EURO/kg for the common fluids. The goal of taxation is clear: To make GWP refrigerants unattractive because...... of their price. In conjunction with tax comes a phase-out scenario which shall be effective from 2006. The options for "natural" refrigerants without ODP and GWP are limited to five fluids which are ammonia (toxic), carbon dioxide (very high pressures), hydrocarbons (flammable), air (relatively low efficiencies...

  5. A cryogenic axial-centrifugal compressor for superfluid helium refrigeration

    CERN Document Server

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

    1997-01-01

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

  6. 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 simulation s * vapor–liquid equilibrium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.853, year: 2010

  7. 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...

  8. A decentralized control method for direct smart grid control of refrigeration systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Izadi-Zamanabadi, Roozbeh; Rasmussen, Henrik

    2013-01-01

    . No model information is required in this method. The temperature limits/constraints are respected. A novel adaptive saturation filter is also proposed to increase the system flexibility in storing and delivering the energy. The proposed control strategy is applied to a simulation benchmark that fairly......A decentralized control method is proposed to govern the electrical power consumption of supermarket refrigeration systems (SRS) for demand-side management in the smart grid. The control structure is designed in a supervisory level to provide desired set-points for distributed level controllers...

  9. Industrial applications of refrigeration. General considerations; Applications industrielles du froid. Generalites

    Energy Technology Data Exchange (ETDEWEB)

    Marvillet, Ch. [Ecole Centrale de Lyon, 69 - Ecully (France); Groupement pour la Recherche sur les Echangeurs Thermiques, GRETh (France)

    2001-10-01

    The refrigeration process consists in the lowering of the temperature of a product or of a process below the ambient temperature. Thus, the refrigeration process implies a heat absorption process for the production of coldness. Two ways of coldness production are considered: the mechanical refrigeration using compression or absorption cycle machineries, and the cryogenic refrigeration which requires the use of industrial fluids like liquid nitrogen, helium or CO{sub 2}. This article presents the different functions of refrigeration in industrial processes and the effects of temperature on inert or living matter (influence of temperature on the physical properties, thermodynamic state, and physico-chemical transformations of solids, bodies and substances, influence of temperature on the transformation processes of food products, mechanical refrigeration and mastery of fermentation). (J.S.)

  10. Improvement of two-stage GM refrigerator performance using a hybrid regenerator

    International Nuclear Information System (INIS)

    Ke, G.; Makuuchi, H.; Hashimoto, T.; Onishi, A.; Li, R.; Satoh, T.; Kanazawa, Y.

    1994-01-01

    To improve the performance of two-stage GM refrigerators, a hybrid regenerator with magnetic materials of Er 3 Ni and ErNi 0.9 Co 0.1 was used in the 2nd stage regenerator because of its large heat exchange capacity. The largest refrigeration capacity achieved with the hybrid regenerator was 0.95W at helium liquefied temperature of 4.2K. This capacity is 15.9% greater than the 0.82W refrigerator with only Er 3 Ni as the 2nd regenerator material. Use of the hybrid regenerator not only increases the refrigeration capacity at 4.2K, but also allows the 4K GM refrigerator to be used with large 1st stage refrigeration capacity, thus making it more practical

  11. Automated modelling of complex refrigeration cycles through topological structure analysis

    International Nuclear Information System (INIS)

    Belman-Flores, J.M.; Riesco-Avila, J.M.; Gallegos-Munoz, A.; Navarro-Esbri, J.; Aceves, S.M.

    2009-01-01

    We have developed a computational method for analysis of refrigeration cycles. The method is well suited for automated analysis of complex refrigeration systems. The refrigerator is specified through a description of flows representing thermodynamic sates at system locations; components that modify the thermodynamic state of a flow; and controls that specify flow characteristics at selected points in the diagram. A system of equations is then established for the refrigerator, based on mass, energy and momentum balances for each of the system components. Controls specify the values of certain system variables, thereby reducing the number of unknowns. It is found that the system of equations for the refrigerator may contain a number of redundant or duplicate equations, and therefore further equations are necessary for a full characterization. The number of additional equations is related to the number of loops in the cycle, and this is calculated by a matrix-based topological method. The methodology is demonstrated through an analysis of a two-stage refrigeration cycle.

  12. Carnot type magnetic refrigeration below 4.2 K - computer simulation

    International Nuclear Information System (INIS)

    Hashimoto, T.; Numazawa, T.; Maro, T.

    1984-01-01

    Cooling devices based on a utilization of the Carnot type magnetic refrigeration cycle are usually selected for the temperature range from 20 K to 1.8 K. However, the refrigeration power in the case of such devices is frequently limited by the heat transfer coefficient between the heat source and the magnetic working substance. Thus, in a magnetic refrigerator studied by Delpuech et al. (1981), the refrigeration power is mainly restricted by the heat transfer coefficient in the isothermal magnetization process at 4.2 K. The present investigation is concerned with the development of a method for achieving high refrigeration power on the basis of a study utilizing computer simulation. One of two methods considered for enhancing refrigeration power is related to the change in the magnetic field, while the other method involves an enlargement of the effective area of gadolinium-gallium-garnet (GGG) with the aid of deep grooves in the surface. 6 references

  13. Refrigerator retirement and replacement programs : lessons learned and application to an Ontario wide program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-05-15

    The best practices in refrigerator retirement programs in North America were identified in an effort to develop a concept for an Ontario-wide provincial refrigerator retirement program. The report focused on describing refrigerator retirement programs, namely those programs that focused on getting rid of old secondary refrigerators. The report excluded refrigerator replacement programs, which encourage householders to retire their refrigerators early and replace them with an energy star refrigerator. However, it was noted that in several regions, both replacement and retirement programs are offered at the same time. The report provided background information on energy use by refrigerators as well as refrigerator retirement and replacement programs. Types of refrigerator retirement and replacement programs and the environmental benefits of these programs were also described. The report also addressed the potential energy impact of an Ontario-wide refrigerator retirement program as well as consumer incentive and bounties initiatives to encourage households to retire units. Other topics covered in the report included the design of typical refrigerator retirement and replacement programs; collection and recycling of retired refrigerators; reported costs of refrigerator retirement and replacement programs; as well as marketing and advertising. The role of retailers and manufacturers and reported lessons learned from refrigerator retirement and replacement were also presented. 14 refs., 6 tabs., 6 appendices.

  14. Experimental investigation on heating performance of heat pump for electric vehicles at −20 °C ambient temperature

    International Nuclear Information System (INIS)

    Qin, Fei; Xue, Qingfeng; Albarracin Velez, Giovanny Marcelo; Zhang, Guiying; Zou, Huiming; Tian, Changqing

    2015-01-01

    Highlights: • An ASHP system with refrigerant injection for EVs is designed, for cold regions. • The heat performances of the system are tested at −20 °C ambient temperature. • The system cycle process with refrigerant injection are analyzed on lgP-H diagrams. • The effects of refrigerant injection, dryness, and in-car inlet state are discussed. • The new system can improve heating and own better application prospect. - Abstract: Since the performance of conventional air source heat pump (ASHP) for electric vehicles (EVs) is apt to decline sharply in low ambient temperature, it will consume more electricity of the cell, and affect driving mileage in cold regions. Aiming at developing high efficiency heating system for EVs in cold regions, an ASHP system applying refrigerant injection for EVs is designed, as well as the test bench is built to investigate its performance. According to the operation condition of EVs, heating performances are tested on different in-car inlet air temperature and various fresh air ratios under −20 °C ambient temperature. The system cycle process with refrigerant injection, as well as the influences of refrigerant injection and dryness are also analyzed and discussed. The results show that the heating capacity of the ASHP with refrigerant injection can be increased up to 31%, and in comparison with the conventional heat pump system its heating performance is better when in-car inlet temperature is above −10 °C. Therefore, ASHP with refrigerant injection has great potentiality to be applied for the EVs in cold regions

  15. The estimation of energy efficiency for hybrid refrigeration system

    International Nuclear Information System (INIS)

    Gazda, Wiesław; Kozioł, Joachim

    2013-01-01

    Highlights: ► We present the experimental setup and the model of the hybrid cooling system. ► We examine impact of the operating parameters of the hybrid cooling system on the energy efficiency indicators. ► A comparison of the final and the primary energy use for a combination of the cooling systems is carried out. ► We explain the relationship between the COP and PER values for the analysed cooling systems. -- Abstract: The concept of the air blast-cryogenic freezing method (ABCF) is based on an innovative hybrid refrigeration system with one common cooling space. The hybrid cooling system consists of a vapor compression refrigeration system and a cryogenic refrigeration system. The prototype experimental setup for this method on the laboratory scale is discussed. The application of the results of experimental investigations and the theoretical–empirical model makes it possible to calculate the cooling capacity as well as the final and primary energy use in the hybrid system. The energetic analysis has been carried out for the operating modes of the refrigerating systems for the required temperatures inside the cooling chamber of −5 °C, −10 °C and −15 °C. For the estimation of the energy efficiency the coefficient of performance COP and the primary energy ratio PER for the hybrid refrigeration system are proposed. A comparison of these coefficients for the vapor compression refrigeration and the cryogenic refrigeration system has also been presented.

  16. 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 shell......-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....

  17. 49 CFR 176.93 - Vehicles having refrigerating or heating equipment.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Vehicles having refrigerating or heating equipment... Transported on Board Ferry Vessels § 176.93 Vehicles having refrigerating or heating equipment. (a) A transport vehicle fitted with refrigerating or heating equipment using a flammable liquid or Division 2.1...

  18. 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.

  19. A parasitic magnetic refrigerator for cooling superconducting magnet

    International Nuclear Information System (INIS)

    Nakagome, H.; Takahashi, M.; Ogiwara, H.

    1988-01-01

    The application of magnetic refrigeration principle at a liquid helium temperature (4.2K) is very useful for cooling a superconducting magnet for its potential of high efficiency. The magnetic refrigerator equipped with 14 pieces of GGG (gadolinium-gallium-garnet) single crystal unit (30mm in diameter 10mm in length) in the rotating disk operates along the gradient of the magnetic field produced by a racetrack superconducting magnet, whose maximum magnetic field is 4.5 Tesla and the minimum field is 1.1 Tesla. The final goal of their program is to liquefy gaseous helium evaporated from a liquid helium vessel of the racetrack superconducting magnet by the rotating magnetic refrigerator which operates by using the magnetic field of the superconducting magnet. A 0.12W refrigeration power in the 0.72rpm operation has been achieved under condition of 4.2K to 11.5K operation. The helium evaporation rate of this magnet system is estimated as the order of 10mW, and the achieved refrigeration power of 0.12W at 4.2K is sufficient for cooling the superconducting magnet

  20. 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 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...

  1. Modelling refrigerant distribution in microchannel evaporators

    DEFF Research Database (Denmark)

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

    2009-01-01

    of the refrigerant distribution is carried out for two channels in parallel and for two different cases. In the first case maldistribution of the inlet quality into the channels is considered, and in the second case a non-uniform airflow on the secondary side is considered. In both cases the total mixed superheat...... 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...

  2. Load leveling on industrial refrigeration systems

    Science.gov (United States)

    Bierenbaum, H. S.; Kraus, A. D.

    1982-01-01

    A computer model was constructed of a brewery with a 2000 horsepower compressor/refrigeration system. The various conservation and load management options were simulated using the validated model. The savings available for implementing the most promising options were verified by trials in the brewery. Result show that an optimized methodology for implementing load leveling and energy conservation consisted of: (1) adjusting (or tuning) refrigeration systems controller variables to minimize unnecessary compressor starts, (2) The primary refrigeration system operating parameters, compressor suction pressure, and discharge pressure are carefully controlled (modulated) to satisfy product quality constraints (as well as in-process material cooling rates and temperature levels) and energy evaluating the energy cost savings associated with reject heat recovery, and (4) a decision is made to implement the reject heat recovery system based on a cost/benefits analysis.

  3. Thermal investigations of a room temperature magnetic refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Smaili, Arezki; Chiba, Younes [Ecole Nationale Polytechnique d' Alger (Algeria)], email: arezki.smaili@enp.edu.dz

    2011-07-01

    Magnetic refrigeration is a concept based on the magnetocaloric effect that some materials exhibit when the external magnetic field changes. The aim of this paper is to assess the performance of a numerical model in predicting parameters of an active magnetic regenerator refrigerator. Numerical simulations were conducted to perform a thermal analysis on an active magnetic regenerator refrigerator operating near room temperature with and without applied cooling load. Curves of temperature span, cooling capacity and thermal efficiency as functions of the operating conditions were drawn and are presented in this paper. Results showed that at fixed frequency Ql versus mf has an optimum and COP was increased with cycle frequency values. This study demonstrated that the proposed numerical model could be used to predict parameters of an active magnetic regenerator refrigerator as it provides consistent results.

  4. 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...... there is a possibility for optimizing the power consumption by utilizing load shifting strategies. This paper describes the dynamics and the modeling of a vapor compression refrigeration system needed for sufficiently realistic estimation of the power consumption and its minimization. This leads to a non-convex function...... 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...

  5. Helium refrigeration system for BNL colliding beam accelerator

    International Nuclear Information System (INIS)

    Brown, D.P.; Farah, Y.; Gibbs, R.J.; Schlafke, A.P.; Schneider, W.J.; Sondericker, J.H.; Wu, K.C.

    1983-01-01

    A Helium Refrigeration System which will supply the cooling required for the Colliding Beam Accelerator at Brookhaven National Laboratory is under construction. Testing of the compressor system is scheduled for late 1983 and will be followed by refrigerator acceptance tests in 1984. The refrigerator has a design capacity of 24.8 kW at a temperature level near 4K while simultaneously producing 55 kW for heat shield loads at 55K. When completed, the helium refrigerator will be the world's largest. Twenty-five oil-injected screw compressors with an installed total of 23,250 horsepower will supply the gas required. One of the unique features of the cycle is the application of three centrifugal compressors used at liquid helium temperature to produce the low temperatures (2.5K) and high flow rates (4154 g/s) required for this service

  6. 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.

  7. Displacer Diameter Effect in Displacer Pulse Tube Refrigerator

    Science.gov (United States)

    Zhu, Shaowei

    2017-12-01

    Gas driving displacer pulse tube refrigerators are one of the work recovery type of pulse tube refrigerators whose theoretical efficiency is the same as Stirling refrigerators'. Its cooling power is from the displacement of the displacer. Displace diameter, rod diameter and pressure drop of the regenerator influence the displacement, which are investigated by numerical simulation. It is shown that the displacement ratio of the displacer over the piston is almost not affected by the displacer diameter at the same rod diameter ratio, or displacer with different diameters almost has the same performance.

  8. Refrigeration Performance and Entropy Generation Analysis for Reciprocating Magnetic Refrigerator with Gd Plates

    Directory of Open Access Journals (Sweden)

    Yonghua You

    2018-06-01

    Full Text Available In the current work, a novel 2D numerical model of stationary grids was developed for reciprocating magnetic refrigerators, with Gd plates, in which the magneto-caloric properties, derived from the Weiss molecular field theory, were adopted for the built-in energy source of the magneto-caloric effect. The numerical simulation was conducted under the conditions of different structural and operational parameters, and the effects of the relative fluid displacement (φ on the specific refrigeration capacity (qref and the Coefficient of Performance (COP were obtained. Besides the variations of entropy, the generation rate and number were studied and the contours of the local entropy generation rate are presented for discussion. From the current work, it is found that with an increase in φ, both the qref and COP followed the convex variation trend, while the entropy generation number (Ns varied concavely. As for the current cases, the maximal qref and COP were equal to 151.2 kW/m3 and 9.11, respectively, while the lowest Ns was the value of 2.4 × 10−4 K−1. However, the optimal φ for the largest qref and COP, and for the lowest Ns, were inconsistent, thus, some compromises need be made in the optimization of magnetic refrigerators.

  9. 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.

  10. Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

    Directory of Open Access Journals (Sweden)

    Mishra Shubham

    2016-12-01

    Full Text Available Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%, which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle. Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

  11. Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

    Science.gov (United States)

    Mishra, Shubham; Sarkar, Jahar

    2016-12-01

    Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene) is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP) for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%), which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle). Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

  12. 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...... and the methods are evaluated with respect to energy efficiency....

  13. Advanced exergoeconomic analysis of the multistage mixed refrigerant systems

    International Nuclear Information System (INIS)

    Mehrpooya, Mehdi; Ansarinasab, Hojat

    2015-01-01

    Highlights: • Advanced exergoeconomic analysis is performed for mixed refrigerant systems. • Cost of investment is divided into avoidable/unavoidable and endogenous/exogenous. • Results show that interactions between the components is not considerable. - Abstract: Advanced exergoeconomic analysis is applied on three multi stage mixed refrigerant liquefaction processes. They are propane precooled mixed refrigerant, dual mixed refrigerant and mixed fluid cascade. Cost of investment and exergy destruction for the components with high inefficiencies are divided into avoidable/unavoidable and endogenous/exogenous parts. According to the avoidable exergy destruction cost in propane precooled mixed refrigerant process, C-2 compressor with 455.5 ($/h), in dual mixed refrigerant process, C-1 compressor with 510.8 ($/h) and in mixed fluid cascade process, C-2/1 compressor with 338.8 ($/h) should be considered first. A comparison between the conventional and advanced exergoeconomic analysis is done by three important parameters: Exergy efficiency, exergoeconomic factor and total costs. Results show that interactions between the process components are not considerable because cost of investment and exergy destruction in most of them are endogenous. Exergy destruction cost of the compressors is avoidable while heat exchangers and air coolers destruction cost are unavoidable. Investment cost of heat exchangers and air coolers are avoidable while compressor’s are unavoidable

  14. Cryo-refrigerators for CNS applications

    International Nuclear Information System (INIS)

    Clausen, J.; Lesser, J.; Sebastianutto, R.

    2001-01-01

    Cryo-refrigeration plants for cold neutron sources belong to the field of auxiliary plants or utility facilities of the reactor. In general, they are classified as non-nuclear and serve to dissipate the heat generated in the liquid hydrogen or deuterium from moderating the neutrons of the cold neutron source. Cryo-refrigeration plants for the temperature range of 20 K supply either refrigeration at constant temperature by means of evaporating the cryogenic coolant (usually hydrogen) or, as usual with cold sources, in a specific temperature range by means of warming-up the cryogenic coolant (usually helium) in the moderator or heat exchanger (condensation or subcooling of the deuterium). The operator's requirements to a refrigeration plant are, first of all, that the plant adjusts itself - at low-maintenance or maintenance-free - to the various operation modes at best thermodynamic efficiencies and that it offers as much operating convenience and operating safety as possible. Additional requirements are short times for cool-down, capacity adjustment, stand-by operation in order to avoid poisoning of the cold source and further operational requirements. However, these requirements are limited by mechanics, thermodynamics and financial means. For this reason, for each application a technical solution must be found which is optimally adapted to the competing requirements and which is based on a standard product of the manufacturer, if possible. The operator's different requirements have to be taken in account with regard to the design of the plant and choice of the components; economic aspects in addition also have to be considered. Wherever possible, proven standard components should be used. (orig.)

  15. 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.

  16. Research for Actively Reducing Infrared Radiation by Thermoelectric Refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hoon; Kim, Kyomin; Kim, Woochul [Yonsei Univ., Seoul (Korea, Republic of)

    2017-03-15

    We introduced a technology for reducing infrared radiation through the active cooling of hot surfaces by using a thermoelectric refrigerator. Certain surfaces were heated by aerodynamic heating, and the heat generation processes are proposed here. We calculated the temperatures and radiations from surfaces, while using thermoelectric refrigerators to cool the surfaces. The results showed that the contrast between the radiations of certain surfaces and the ambient environments can be removed using thermoelectric refrigerators.

  17. Inventory of refrigeration training in Quebec given within the framework of the intervention program of Natural Resources Canada's CETC-Varennes and the AEE of Ressources naturelles du Quebec; Inventaire de la formation en refrigeration au Quebec dans le cadre du programme d'intervention initie par le CTEC-Varennes de ressources naturelles Canada et l'AEE de ressources naturelles du Quebec

    Energy Technology Data Exchange (ETDEWEB)

    Garant, G.J. [Association des Arenas du Quebec Inc., Montreal, PQ (Canada)

    2004-03-01

    This paper relates information concerning vocational courses in refrigeration in Quebec, with reference to the newly formed National Committee on Vocational and Technical Educational Programs. The aim of the paper was to collect data on the availability of refrigeration courses. A description of course outlines was provided, with reference to requirements in high school and at the college level. Requirement details for additional courses in heating and electricity refrigeration were also provided. The status of diplomas was also discussed, with reference to employment opportunities in management and analysis upon completion of the Diploma of Collegial Studies, which requires additional courses in energy conservation. Opportunities in the labour market were reviewed, as well as information on privately run courses. Particular reference was made concerning the Canadian Energy Technology Centre (CETC) as a leading research facility for refrigeration concepts and design. It was noted that very few courses on refrigeration technology are offered at the university level, and that currently only one distance education course on refrigeration has been recognized. As a result of this investigation, the Quebec Arena Association has determined that development of new courses is a priority, especially given that only the CETC currently offers courses on refrigeration for arenas and curling rinks. New courses should focus on arena and rink refrigeration technologies, with particular reference to new technologies and developments in energy efficiency. tabs., figs.

  18. Studying the Variable Refrigerant Volume (VRV) System and Determining the Root Cause of its Problem in Building 37, Malaysian Nuclear Agency

    International Nuclear Information System (INIS)

    Suhafizudin Zainal Anuar; Mohamad Suhaimi Yahaya; Jusnan Hasim; Suhilah Mohd Ali; Mohd Khafidz Shamsuddin

    2015-01-01

    Variable Refrigerant Volume (VRV) system is one of the Heating, Ventilation and Air Conditioning (HVAC) type in the building. VRV system is a multi-split type air conditioner that uses variable refrigerant flow control to provide customers with the ability to maintain individual zone control in each room and floor of a building. VRV used in Building 37 is made by Mitsubishi Heavy Industries that was completely installed in 2011 with two pipes system format. The objectives of this study are to understand the Variable Refrigerant Volume (VRV) system and also to study the root cause of its problem in Building 37, Agensi Nuklear Malaysia. The result of the study study suggests poor workmanship during installation process and insufficient electrical grounding are suspected as the causes of on-going and repeating problems occurred. Hence, Bahagian Kejuruteraan (BKJ) has worked out with the service contractor to identify the main problem and leaking area before proceeding with repair and commissioning activities. (author)

  19. The UK-DALE dataset, domestic appliance-level electricity demand and whole-house demand from five UK homes.

    Science.gov (United States)

    Kelly, Jack; Knottenbelt, William

    2015-01-01

    Many countries are rolling out smart electricity meters. These measure a home's total power demand. However, research into consumer behaviour suggests that consumers are best able to improve their energy efficiency when provided with itemised, appliance-by-appliance consumption information. Energy disaggregation is a computational technique for estimating appliance-by-appliance energy consumption from a whole-house meter signal. To conduct research on disaggregation algorithms, researchers require data describing not just the aggregate demand per building but also the 'ground truth' demand of individual appliances. In this context, we present UK-DALE: an open-access dataset from the UK recording Domestic Appliance-Level Electricity at a sample rate of 16 kHz for the whole-house and at 1/6 Hz for individual appliances. This is the first open access UK dataset at this temporal resolution. We recorded from five houses, one of which was recorded for 655 days, the longest duration we are aware of for any energy dataset at this sample rate. We also describe the low-cost, open-source, wireless system we built for collecting our dataset.

  20. Probabilistic Model for Listeria monocytogenes Growth during Distribution, Retail Storage, and Domestic Storage of Pasteurized Milk ▿

    Science.gov (United States)

    Koutsoumanis, Konstantinos; Pavlis, Athanasios; Nychas, George-John E.; Xanthiakos, Konstantinos

    2010-01-01

    A survey on the time-temperature conditions of pasteurized milk in Greece during transportation to retail, retail storage, and domestic storage and handling was performed. The data derived from the survey were described with appropriate probability distributions and introduced into a growth model of Listeria monocytogenes in pasteurized milk which was appropriately modified for taking into account strain variability. Based on the above components, a probabilistic model was applied to evaluate the growth of L. monocytogenes during the chill chain of pasteurized milk using a Monte Carlo simulation. The model predicted that, in 44.8% of the milk cartons released in the market, the pathogen will grow until the time of consumption. For these products the estimated mean total growth of L. monocytogenes during transportation, retail storage, and domestic storage was 0.93 log CFU, with 95th and 99th percentiles of 2.68 and 4.01 log CFU, respectively. Although based on EU regulation 2073/2005 pasteurized milk produced in Greece belongs to the category of products that do not allow the growth of L. monocytogenes due to a shelf life (defined by law) of 5 days, the above results show that this shelf life limit cannot prevent L. monocytogenes from growing under the current chill chain conditions. The predicted percentage of milk cartons—initially contaminated with 1 cell/1-liter carton—in which the pathogen exceeds the safety criterion of 100 cells/ml at the time of consumption was 0.14%. The probabilistic model was used for an importance analysis of the chill chain factors, using rank order correlation, while selected intervention and shelf life increase scenarios were evaluated. The results showed that simple interventions, such as excluding the door shelf from the domestic storage of pasteurized milk, can effectively reduce the growth of the pathogen. The door shelf was found to be the warmest position in domestic refrigerators, and it was most frequently used by the

  1. 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...... control is to let an optimization procedure take over the task of operating the refrigeration system and thereby replace the role of the operator in the traditional control structure. In the context of refrigeration systems, the idea is to divide the optimizing control structure into two parts: A part...... optimizing the steady state operation "set-point optimizing control" and a part optimizing dynamic behaviour of the system "dynamical optimizing control". A novel approach for set-point optimization will be presented. The general idea is to use a prediction of the steady state, for computation of the cost...

  2. 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 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...

  3. Domestic Hot Water Production with Ground Source Heat Pump in Apartment Buildings

    Directory of Open Access Journals (Sweden)

    Jukka Yrjölä

    2015-08-01

    Full Text Available Producing domestic hot water (DHW with a ground source heat pump (GSHP is challenging due to the high temperature (HT of DHW. There are many studies proving the better performance of cascade heat pumps compared to single-stage heat pumps when the difference between the condensing and the evaporation temperature is large. In this system approach study, different GSHP arrangements are described and computationally compared. A two-stage heat pump arrangement is introduced in which water tanks of the heating system are utilized for warming up the DHW in two stages. It is shown that the electricity consumption with this two-stage system is approximately 31% less than with the single-stage heat pump and 12% less than with the cascade system. Further, both low temperature (LT and HT heat pumps can run alone, which is not common in cascade or other two-stage heat pumps. This is advantageous because the high loads of the space heating and DHW production are not simultaneous. Proper insulation of the DHW and recirculation pipe network is essential, and drying towel rails or other heating coils should be avoided when aiming for a high efficiency. The refrigerants in the calculations are R407C for the LT heat pump and R134a for the HT heat pump. Investment costs are excluded from calculations.

  4. Theoretical analysis of ejector refrigeration system performance under overall modes

    International Nuclear Information System (INIS)

    Chen, Weixiong; Shi, Chaoyin; Zhang, Shuangping; Chen, Huiqiang; Chong, Daotong; Yan, Junjie

    2017-01-01

    Highlights: • Real gas theoretical model is used to get ejector performance at critical/sub-critical modes. • The model has a better accuracy against the experiment results compared to ideal gas model. • The overall performances of two refrigerants are analyzed based on the parameter analysis. - Abstract: The ejector refrigeration integrated in the air-conditioning system is a promising technology, because it could be driven by the low grade energy. In the present study, a theoretical calculation based on the real gas property is put forward to estimate the ejector refrigeration system performance under overall modes (critical/sub-critical modes). The experimental data from literature are applied to validate the proposed model. The findings show that the proposed model has higher accuracy compared to the model using the ideal gas law, especially when the ejector operates at sub-critical mode. Then, the performances of the ejector refrigeration circle using different refrigerants are analyzed. R290 and R134a are selected as typical refrigerants by considering the aspects of COP, environmental impact, safety and economy. Finally, the ejector refrigeration performance is investigated under variable operation conditions with R290 and R134a as refrigerants. The results show that the R290 ejector circle has higher COP under critical mode and could operate at low evaporator temperature. However, the performance would decrease rapidly at high condenser temperature. The performance of R134a ejector circle is the opposite, with relatively lower COP, and higher COP at high condenser temperature compared to R290.

  5. Role of CCTs in the evolving domestic electricity market

    Energy Technology Data Exchange (ETDEWEB)

    Grahame, T.J. [Dept. of Energy, Washington, DC (United States). Office of Coal and Power Systems

    1997-12-31

    The paper summarizes the key points and issues in the role of clean coal technologies in the domestic marketplace. Then suggested solutions to bringing precommercial CCTs to the market are presented. Finally, the outlook for possible actions by government and the private sector are briefly discussed.

  6. Food irradiation combined with refrigeration in food industrial plants

    International Nuclear Information System (INIS)

    Boisseau, P.

    1991-01-01

    Food irradiation and refrigeration are both physical treatments used for food preservation. The complementarity of their effects on food is the best reason for their combination. Irradiation is essentially used for disinfestation and refrigeration to protect food against non microbial degradations. Refrigeration and irradiation could be combined for shelf life extension of fresh fruits and vegetables or reduction of microflora in animal products, without loss of quality. Freezing must be combined with ionizing treatments if high doses are necessary as it is the case with destruction of pathogens in meat or food sterilization. Some examples of combination of refrigeration and irradiation are routinely applied in some industrial plants in France but it is expected that more and more combined treatments will be used thanks to research

  7. 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.

  8. Electricity energy outlook in Malaysia

    International Nuclear Information System (INIS)

    Tan, C S; Leong, Y P; Maragatham, K

    2013-01-01

    Population and income growth are the key drivers behind the growing demand for energy. Demand for electricity in Malaysia is always growing in tandem with its Gross Domestic Product (GDP) growth. The growth for electricity in Malaysia forecasted by Economic Planning Unit (EPU) has shown an increase of 3.52% in 2012 compared to 3.48% in 2011. This growth has been driven by strong demand growth from commercial and domestic sectors. The share of electricity consumption to total energy consumption has increased from 17.4% in 2007 to 21.7% in 2012. The total electricity production was reported at 122.12TWh in 2012, where gas is still the major fuel source contributing to 52.7% of the total generation fuel mix of electricity followed by Coal, 38.9%, hydro, 7.3%, oil, 1% and others, 0.2%. This paper aims to discuss the energy outlook particularly the electricity production and ways toward greener environment in electricity production in Malaysia

  9. Electricity energy outlook in Malaysia

    Science.gov (United States)

    Tan, C. S.; Maragatham, K.; Leong, Y. P.

    2013-06-01

    Population and income growth are the key drivers behind the growing demand for energy. Demand for electricity in Malaysia is always growing in tandem with its Gross Domestic Product (GDP) growth. The growth for electricity in Malaysia forecasted by Economic Planning Unit (EPU) has shown an increase of 3.52% in 2012 compared to 3.48% in 2011. This growth has been driven by strong demand growth from commercial and domestic sectors. The share of electricity consumption to total energy consumption has increased from 17.4% in 2007 to 21.7% in 2012. The total electricity production was reported at 122.12TWh in 2012, where gas is still the major fuel source contributing to 52.7% of the total generation fuel mix of electricity followed by Coal, 38.9%, hydro, 7.3%, oil, 1% and others, 0.2%. This paper aims to discuss the energy outlook particularly the electricity production and ways toward greener environment in electricity production in Malaysia

  10. Potential benefits of saturation cycle with two-phase refrigerant injection

    International Nuclear Information System (INIS)

    Lee, Hoseong; Hwang, Yunho; Radermacher, Reinhard; Chun, Ho-Hwan

    2013-01-01

    In this paper, a saturation cycle is proposed to enhance a vapor compression cycle performance by reducing thermodynamic losses associated with single phase gas compression and isenthalpic expansion. In order to approach the saturation cycle, a two-phase refrigerant injection technique is applied to the multi-stage cycle. This multi-stage cycle with different options is modeled, and its performance is evaluated under ASHRAE standard operating conditions for air conditioning systems. Moreover, the two-phase refrigerant injection cycle is compared with the typical vapor injection cycle which is utilizing the internal heat exchanger or the flash tank. Low GWP refrigerants are applied to this two-phase refrigerant injection cycle. In terms of the COP and its improvement, R123 has a higher potential than any other refrigerants in the multi-stage cycle. Lastly, practical ideas realizing the saturation cycle are discussed such as multi-stage phase separator, phase separator with helical structure inside, and injection location of the compressor. -- Highlights: • A saturation cycle is proposed to enhance the vapor compression cycle performance. • Two-phase refrigerant injection technique is applied to the multi-stage cycle. • Modeling results of the proposed cycle show the significant performance improvement. • Low GWP refrigerants are applied and R123 shows the highest performance. • New parameters, α and ε, are used to show the potential of the saturation cycle

  11. 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.

  12. 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.

  13. Data-Driven Predictive Direct Load Control of Refrigeration Systems

    DEFF Research Database (Denmark)

    Shafiei, Seyed Ehsan; Knudsen, Torben; Wisniewski, Rafal

    2015-01-01

    A predictive control using subspace identification is applied for the smart grid integration of refrigeration systems under a direct load control scheme. A realistic demand response scenario based on regulation of the electrical power consumption is considered. A receding horizon optimal control...... is proposed to fulfil two important objectives: to secure high coefficient of performance and to participate in power consumption management. Moreover, a new method for design of input signals for system identification is put forward. The control method is fully data driven without an explicit use of model...... against real data. The performance improvement results in a 22% reduction in the energy consumption. A comparative simulation is accomplished showing the superiority of the method over the existing approaches in terms of the load following performance....

  14. Thermoeconomic model of a commercial transcritical booster refrigeration system

    DEFF Research Database (Denmark)

    Ommen, Torben Schmidt; Elmegaard, Brian

    2011-01-01

    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...... of exergy for cooling. Second law analysis is needed to illustrate the characteristics of the plant at different load rates, according to the alternating load profile and corresponding to outdoor conditions. With the detailed model, different uses of the analysis are possible, including thermoeconomic...

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

    Science.gov (United States)

    DeVault, Robert C.; Biermann, Wendell J.

    1993-01-01

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

  16. Current fluctuations in quantum absorption refrigerators

    Science.gov (United States)

    Segal, Dvira

    2018-05-01

    Absorption refrigerators transfer thermal energy from a cold bath to a hot bath without input power by utilizing heat from an additional "work" reservoir. Particularly interesting is a three-level design for a quantum absorption refrigerator, which can be optimized to reach the maximal (Carnot) cooling efficiency. Previous studies of three-level chillers focused on the behavior of the averaged cooling current. Here, we go beyond that and study the full counting statistics of heat exchange in a three-level chiller model. We explain how to obtain the complete cumulant generating function of the refrigerator in a steady state, then derive a partial cumulant generating function, which yields closed-form expressions for both the averaged cooling current and its noise. Our analytical results and simulations are beneficial for the design of nanoscale engines and cooling systems far from equilibrium, with their performance optimized according to different criteria, efficiency, power, fluctuations, and dissipation.

  17. Cooling devices and methods for use with electric submersible pumps

    Science.gov (United States)

    Jankowski, Todd A; Hill, Dallas D

    2014-12-02

    Cooling devices for use with electric submersible pump motors include a refrigerator attached to the end of the electric submersible pump motor with the evaporator heat exchanger accepting all or a portion of the heat load from the motor. The cooling device can be a self-contained bolt-on unit, so that minimal design changes to existing motors are required.

  18. Giant electrical power factor in single-walled chiral carbon nanotube

    International Nuclear Information System (INIS)

    Mensah, S.Y.; Allotey, F.K.A.; Mensah, N.G.; Nkrumah, G.

    2001-10-01

    Using the semiclassical approach we studied the thermoelectrical properties of single-walled chiral carbon nanotubes (SWNTs). We predict a giant electrical power factor and hence proposed the use of carbon nanotubes as thermoelements for refrigeration. (author)

  19. Refrigerator Optimal Scheduling to Minimise the Cost of Operation

    Directory of Open Access Journals (Sweden)

    Bálint Roland

    2016-12-01

    Full Text Available The cost optimal scheduling of a household refrigerator is presented in this work. The fundamental approach is the model predictive control methodology applied to the piecewise affine model of the refrigerator.

  20. Advanced Supermarket Refrigeration/Heat Recovery Systems. Country Report, Denmark

    DEFF Research Database (Denmark)

    Knudsen, Hans-Jørgen Høgaard; Christensen, K. G.

    Annex 26 is the first international project under the IEA Heat Pump Programme that links refrigeration and heat pump technology. Recovering heat from advanced supermarket refrigeration systems for space and water heating seems obvious and is beneficial for owners and operators. Because the great...... number of supermarkets that offer frozen and chilled food and further growth of this sector may be expected, the amount of energy used for refrigeration is enormous and will likely increase in the near future. Annex 26 analysed several advanced supermarket refrigeration systems and came to remarkable...... conclusions as far energy conservation and TEWI reduction is concerned. The conclusion justify that advanced supermarket systems with heat recovery should receive great attention and support. And there is still further research needed in several areas. The Annex also included a thorough system analyses...

  1. Second law analysis of the transcritical CO2 refrigeration cycle

    International Nuclear Information System (INIS)

    Fartaj, Amir; Ting, David S.-K.; Yang, Wendy W.

    2004-01-01

    Because of the global warming impact of HFCs, the use of natural refrigerants has received worldwide attention. Efficient use of refrigerants is of pressing concern to the present automotive and HVAC industries. The natural refrigerant, carbon dioxide (CO 2 ), exhibits promise for use in automotive air conditioning systems, in particular the transcritical CO 2 refrigeration cycle. The objective of this work is to identify the main factors that affect CO 2 system performance. A second law of thermodynamic analysis on the entire CO 2 refrigeration cycle is conducted so that the effectiveness of the components of the system can be deduced and ranked, allowing future efforts to focus on improving the components that have the highest potential for advancement. The analysis reveals that the compressor and the gas cooler exhibit the largest non-idealities within the system, and hence, efforts should be focused on improving these components

  2. On subcooler design for integrated two-temperature supermarket refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Liang [Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200240 (China); Zhang, Chun-Lu [College of Mechanical Engineering, Tongji University, No. 4800, Cao An Highway, Shanghai 201804 (China)

    2011-01-15

    The energy saving opportunity of supermarket refrigeration systems using subcooler between the medium-temperature (MT) refrigeration system and the low-temperature (LT) refrigeration system has been identified in the previous work. This paper presents a model-based comprehensive analysis on the subcooler design. The optimal subcooling control is discussed as well. With optimal subcooler size and subcooling control, the maximum energy savings of integrated two-temperature supermarket refrigeration system using R404A or R134a as working fluid can achieve 27% or 20%, respectively. The load ratio of MT to LT system and the operating conditions have considerable impact on the energy savings. (author)

  3. Second-law-based analysis of vapor-compression refrigeration cycles: Analytical equations for COP and new insights into features of refrigerants

    International Nuclear Information System (INIS)

    Ma, Weiwu; Fang, Song; Su, Bo; Xue, Xinpei; Li, Min

    2017-01-01

    Highlights: • Second-law analysis leads to analytical COP formulas for refrigeration cycles. • Relative errors of the analytical equations are smaller than ±5.0%. • The analytical expressions characterize the influence of refrigerants. • Global entropy analysis elucidates the impact of cycle processes on COP. - Abstract: This article reports a second-law-based analysis of the vapor-compression refrigeration cycle, which leads to a set of explicit theoretical formulas for the coefficient of performance (COP). These analytical expressions provide a fast and accurate approach to computer simulations of the vapor-compression cycle without recourse to thermodynamic diagrams or equations of state. The second-law-based analysis yields specific expressions for the entropy generations of irreversible processes, enabling us to evaluate the thermodynamic features of the refrigerant and to elucidate the thermodynamic mechanisms behind the effects of the cycle processes, including superheat, subcooling, and throttling processes. In particular, these processes can interact, therefore this paper presents a global entropy generation analysis for evaluating the impact of the interacted processes on COP.

  4. Helium dilution refrigerator

    International Nuclear Information System (INIS)

    1973-01-01

    A new system of continuous heat exchange for a helium dilution refrigerator is proposed. The 3 He effluent tube is concurrent with the affluent mixed helium tube in a vertical downward direction. Heat exchange efficiency is enhanced by placing in series a number of elements with an enlarged surface area

  5. Evaluation of refrigerating and air-conditioning technologies in heat cascading systems under the carbon dioxide emissions constraint: the proposal of the energy cascade balance table

    International Nuclear Information System (INIS)

    Shimazaki, Yoichi

    2003-01-01

    The aim of this study was to evaluate the refrigerating and air-conditioning technologies in cases of introducing both heat cascading systems and thermal recycling systems in industries located around urban areas. It is necessary to introduce heat cascading systems in the industrial sector in Japan to reduce carbon dioxide emissions. The concept of heat cascading is the multi-stage use of thermal energy by temperature level. This paper introduces three energy policies for introducing the heat cascading systems. The author develops an energy cascade model based on linear programming so as to minimize the total system costs with carbon taxes. Five cases are investigated. Carbon dioxide emission constraints result in the enhancement of heat cascading, where high temperature heat is supplied for process heating while low temperature heat is shifted to refrigeration. It was found that increasing the amount of garbage combustion waste heat could reduce electric power for the turbo compression refrigerator by promoting waste heat driven ammonia absorption refrigerator. In addition, this study proposes an energy cascade balance table with respect to the temperature level

  6. Technology Application of Environmental Friendly Refrigeration (Green Refrigeration) on Cold Storage for Fishery Industry

    Science.gov (United States)

    Rasta, IM; Susila, IDM; Subagia, IWA

    2018-01-01

    The application of refrigeration technology to postharvest fishery products is an very important. Moreover, Indonesia is a tropical region with relatively high temperatures. Fish storage age can be prolonged with a decrease in temperature. Frozen fish can even be stored for several months. Fish freezing means preparing fish for storage in low-temperature cold storage. The working fluid used in cold storage to cool low-temperature chambers and throw heat into high-temperature environments is refrigerant. So far refrigerant used in cold storage is Hydrochloroflourocarbons (HCFC) that is R-22. Chlor is a gas that causes ODP (Ozone Depleting Potential), while Flour is a gas that causes GWP (Global Warming Potential). Government policy began in 2015 to implement Hydrochloroflourocarbons Phase-Out Management Plan. Hydrocarbon (HC) is an alternative substitute for R-22. HC-22 (propane ≥ 99.5%) has several advantages, among others: environmentally friendly, indicated by a zero ODP value, and GWP = 3 (negligible), thermophysical property and good heat transfer characteristics, vapor phase density Which is low, and good solubility with mineral lubricants. The use of HC-22 in cold storage is less than R-22. From the analysis results obtained, cold storage system using HC-22 has better performance and energy consumption is more efficient than the R-22.

  7. Competitiveness Level of Photovoltaic Solar Systems in Ouagadougou (Burkina Faso: Study Based on the Domestic Electric Meters Calibration

    Directory of Open Access Journals (Sweden)

    Konan Lambert Amani

    2016-01-01

    Full Text Available The mean cost price of electricity in Burkina Faso at the end of the last quarter of 2012 was 158 FCFA/kWh for a country where more than 46% of the population lives below the national poverty threshold. To look for solution to that problem, the resort to photovoltaic solar energy is justified for that country. The purpose of this study is to promote the integration of both technical and economical surveys in solar energy preliminary projects in Ouagadougou. To reach that, investigations were carried out in some households and attention was paid from the calibration of the domestic electric meters. Energy demands collected within each household allow us to design a corresponding solar kit through optimization rules. An estimate was edited and financial viability study for each household was also carried out thereafter. In this study, only households using the national electricity network calibration meter on their disadvantage favorably answered to all financial indicators and appear as the only one that could profit from such project. This work is helpful to note that photovoltaic solar energy still stays at a primitive level of competitiveness compared to conventional energy resources for small systems in Ouagadougou.

  8. CFD investigations on supersonic ejectors for refrigeration applications

    International Nuclear Information System (INIS)

    Bartosiewicz, Y.; Aidoun, Z.; Mercadier, Y.

    2004-01-01

    This paper presents numerical results of a supersonic ejector for refrigeration applications. One of the interesting features is that the current model is based on the NIST properties for the R142b refrigerant: to the authors knowledge, it is the first paper dealing with a local CFD model which takes into account shock-boundary layer interactions in a real refrigerant. The numerical results put demonstrate the crucial role of the secondary nozzle for the mixing rate performance. In addition, these results point out the need of an extensive validation of the turbulence model, especially in the modeling of the off-design mode. (author)

  9. FUZZY THERMOECONOMIC APPROACH TO NANOFLUID SELECTION IN VAPOR COMPRESSION REFRIGERATION CYCLE

    Directory of Open Access Journals (Sweden)

    D. Kuleshov

    2014-06-01

    Full Text Available The working fluid selection in the vapour compression refrigeration cycles has been studied as a fuzzy thermoeconomic optimization problem. Three criteria: thermodynamic (COP Coefficient Of Performance, economic (LCC Life Cycle Cost, and ecologic (GWP – Global Warming Potential are chosen as target functions. The decision variables X as an information characteristics of desired refrigerant are presented by its critical parameters and normal boiling temperature. Local criteria are expressed via thermodynamic properties restored from information characteristics of refrigerant X, as well as life cycle costs are calculated by the standard economic relationships. GWP values are taken from the refrigerant database. Class of substances under consideration is presented by the natural refrigerant R600a embedded with nanostructured materials.

  10. Policy options to reduce consumer waste to zero: comparing product stewardship and extended producer responsibility for refrigerator waste.

    Science.gov (United States)

    Nicol, Scott; Thompson, Shirley

    2007-06-01

    Today, over-consumption, pollution and resource depletion threaten sustainability. Waste management policies frequently fail to reduce consumption, prevent pollution, conserve resources and foster sustainable products. However, waste policies are changing to focus on lifecycle impacts of products from the cradle to the grave by extending the responsibilities of stakeholders to post-consumer management. Product stewardship and extended producer responsibility are two policies in use, with radically different results when compared for one consumer product, refrigerators. North America has enacted product stewardship policies that fail to require producers to take physical or financial responsibility for recycling or for environmentally sound disposal, so that releases of ozone depleting substances routinely occur, which contribute to the expanding the ozone hole. Conversely, Europe's Waste Electrical and Electronic Equipment (WEEE) Directive requires extended producer responsibility, whereby producers collect and manage their own post-consumer waste products. WEEE has resulted in high recycling rates of greater than 85%, reduced emissions of ozone-depleting substances and other toxins, greener production methods, such as replacing greenhouse gas refrigerants with environmentally friendly hydrocarbons and more reuse of refrigerators in the EU in comparison with North America.

  11. Control Methods Utilizing Energy Optimizing Schemes in Refrigeration Systems

    DEFF Research Database (Denmark)

    Larsen, L.S; Thybo, C.; Stoustrup, Jakob

    2003-01-01

    The potential energy savings in refrigeration systems using energy optimal control has been proved to be substantial. This however requires an intelligent control that drives the refrigeration systems towards the energy optimal state. This paper proposes an approach for a control, which drives th...... the condenser pressure towards an optimal state. The objective of this is to present a feasible method that can be used for energy optimizing control. A simulation model of a simple refrigeration system will be used as basis for testing the control method....

  12. Chilling Prospect: Climate Change Effects of Mismanaged Refrigerants in China.

    Science.gov (United States)

    Duan, Huabo; Miller, T Reed; Liu, Gang; Zeng, Xianlai; Yu, Keli; Huang, Qifei; Zuo, Jian; Qin, Yufei; Li, Jinhui

    2018-06-05

    The global community has responded to the dual threats of ozone depletion and climate change from refrigerant emissions (e.g., chlorofluorocarbons, CFCs, and hydrofluorocarbons, HFCs) in refrigerators and air conditioners (RACs) by agreeing to phase out the production of the most damaging chemicals and replacing them with substitutes. Since these refrigerants are "banked" in products during their service life, they will continue to impact our environment for decades to come if they are released due to mismanagement at the end of life. Addressing such long-term impacts of refrigerants requires a dynamic understanding of the RACs' life cycle, which was largely overlooked in previous studies. Based on field surveys and a dynamic model, we reveal the lingering ozone depletion potential (ODP) and significant global warming potential (GWP) of scrap refrigerants in China, the world's largest producer (62%) and consumer (46%) of RACs in 2015, which comes almost entirely from air conditioners rather than refrigerators. If the use and waste management of RACs continue with the current trend, the total GWP of scrap refrigerants in China will peak by 2025 at a level of 135.2 ± 18.9 Mt CO 2 e (equal to approximately 1.2% ± 0.2% of China's total greenhouse gas emissions or the national total of either The Netherlands and Czech Republic in 2015). Our results imply an urgent need for improving the recycling and waste management of RACs in China.

  13. Cycle performance of alternative refrigerants for domestic air-conditioning system based on a small finned tube heat exchanger

    International Nuclear Information System (INIS)

    Cheng, Song; Wang, Shuangfeng; Liu, Zhongmin

    2014-01-01

    In order to find alternative refrigerants which exhibit both favorable cycle performance and environmental friendliness, R32 and R290 were utilized to contrast to R22 and R410A as substitutes in the present study. The experiments were conducted with a 5 mm finned tube heat exchanger based on the enthalpy method in a small split household air conditioner. The results showed that in nominal cooling conditions, the COP R of R32 and R290 were 26.8% and 20.4% higher than R22, 7.3% and 2.1% higher than R410A. And in nominal heating conditions, the COP HR of R32 and R290 were both 11.0% higher than R22, 5.3% higher than R410A. The systems with R290 and R32 have similar capacities to that with R22 and R410A in heating mode, but a relatively huge difference of capacities in cooling mode. In consideration of charge amount, R290 could be considered as the most superior alternative refrigerant in air conditioners with the small finned tube heat exchanger. - Highlights: •Comparisons are made in the air conditioner system based on 5 mm tube fin heat exchanger. •The R22 system has a similar performance to others in heating mode while a huge difference in cooling mode. •The optimal charge of R290 is reduced with nearly no decline in the capacity and COP. •SLHX is attached to the system of R290 and successfully promote safety and capacity. •Heat loads are taken into account to evaluate the advantages and disadvantages of R290 and R32

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-05-28

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

  15. Quantum refrigerators and the third law of thermodynamics.

    Science.gov (United States)

    Levy, Amikam; Alicki, Robert; Kosloff, Ronnie

    2012-06-01

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

  16. Dynamic investigation of the diffusion absorption refrigeration system NH3-H2O-H2

    Directory of Open Access Journals (Sweden)

    Mohamed Izzedine Serge Adjibade

    2017-09-01

    Full Text Available This paper reports on a numerical and experimental study of a diffusion absorption refrigerator. The performance of the system is examined by computer simulation using MATLAB software and Engineering Equations Solver. A dynamic model is developed for each component of the system and solved numerically in order to predict the transient state of the diffusion absorption refrigeration. The experiment set included 0.04 m3 commercial absorption diffusion refrigerator working with the ammonia-water-hydrogen (NH3-H2O-H2 solution. The transient numerical results were validated with the experimental data. The investigations are focused on the dynamic profile of the temperature of each component. The results obtained agree with the experiment; the relative error between numerical and experimental models doesn’t exceed 15% for all temperatures of each component. The increase of the average ambient temperature from 23.04 °C to 32.56 °C causes an increase of the condensation temperature from 29.46 °C to 37.51 °C, and the best evaporation temperature obtained was 3 °C, with an ambient temperature of 23.04 °C. The results show that a minimum starting temperature of 152 °C and 63.8 W electric power are required to initiate the decrease of evaporation temperature.

  17. Superconductivity Program for electric power systems: 1994 annual PEER review. Volume 1, Meeting proceedings

    International Nuclear Information System (INIS)

    1994-01-01

    This is Volume I of information presented at the Annual Peer Review of the Superconductivity Program For Electric Power Systems. Topics include: Wire development; powder synthesis; characterization of superconducting materials; electric power applications; magnetic refrigerators; and motor cooling issues. Individual reports were processed separately for the database

  18. 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)

  19. A review of linear compressors for refrigeration

    OpenAIRE

    Liang, Kun

    2017-01-01

    Linear compressor has no crank mechanism compared with conventional reciprocating compressor. This allows higher efficiency, oil-free operation, lower cost and smaller size when linear compressors are used for vapour compression refrigeration (VCR) system. Typically, a linear compressor consists of a linear motor (connected to a piston) and suspension springs, operated at resonant frequency. This paper presents a review of linear compressors for refrigeration system. Different designs and mod...

  20. Research on sprout inhibition effect of refrigerated garlic by irradiation

    International Nuclear Information System (INIS)

    Zhang Xuan; He Jianzhong; Li Ruijun

    2005-01-01

    This paper researches the sprout inhibition effect by irradiation on refrigerated garlic. The results shows that, the garlic is still in the period of dormancy within 7 days after taken out from the refrigerated warehouse, and irradiation have a good sprout inhibition effect on it. The irradiation dose is 40-90 Gy, the same as that of the post harvest irradiation treatment on garlic. Refrigerate the Zhongmu Garlic (at -2 degree C-0 degree C) until the middle ten days of February the next year, place it at the room temperature (10 degree C-15 degree C) for 1-7 days after taking it out of the warehouse, then use 60 Co γ-ray to irradiate it until the absorbed dose reaches 40-90 Gy, the sprout inhibition effect can be realized. The test also indicates that the deposited time after taking out of the refrigerated warehouse is crucial to the sprout inhibition effect of refrigerated garlic by irradiation. (authors)

  1. A review on adsorption refrigeration technology and adsorption deterioration in physical adsorption systems

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.C.; Li, Y.H. [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Li, D.; Zhang, J.P. [College of Electromechanical Engineering, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China); Xia, Y.Z. [Laboratory of Fiber Materials and Modern Textile, the Growing Base for State Key Laboratory, Qingdao University, 308 Ningxia Road, Qingdao 266071 (China)

    2010-01-15

    As one kind of environmentally friendly refrigeration, the adsorption refrigeration has attracted many attentions in resent decades. This paper introduces the researches of adsorption refrigeration systems with the commonly used working pairs, advanced adsorption cycles, heat and mass transfer enhancement and attempts of adsorption refrigeration applications. Poor heat and mass transfer problem is a bottleneck to prevent the improvements of the adsorption refrigeration technique. Two ways to enhance the heat and mass transfer are discussed in this paper. The adsorption deterioration of adsorbent, another obstacle to physical adsorption refrigeration applications, is also pointed out. And the possible reasons and the possible methods are analyzed. (author)

  2. A review of emerging technologies for food refrigeration applications

    International Nuclear Information System (INIS)

    Tassou, S.A.; Lewis, J.S.; Ge, Y.T.; Hadawey, A.; Chaer, I.

    2010-01-01

    Refrigeration has become an essential part of the food chain. It is used in all stages of the chain, from food processing, to distribution, retail and final consumption in the home. The food industry employs both chilling and freezing processes where the food is cooled from ambient to temperatures above 0 deg. C in the former and between -18 deg. C and -35 deg. C in the latter to slow the physical, microbiological and chemical activities that cause deterioration in foods. In these processes mechanical refrigeration technologies are invariably employed that contribute significantly to the environmental impacts of the food sector both through direct and indirect greenhouse gas emissions. To reduce these emissions, research and development worldwide is aimed at both improving the performance of conventional systems and the development of new refrigeration technologies of potentially much lower environmental impacts. This paper provides a brief review of both current state of the art technologies and emerging refrigeration technologies that have the potential to reduce the environmental impacts of refrigeration in the food industry. The paper also highlights research and development needs to accelerate the development and adoption of these technologies by the food sector.

  3. Optimal Energy Consumption in Refrigeration Systems - Modelling and Non-Convex Optimisation

    DEFF Research Database (Denmark)

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

    2012-01-01

    Supermarket refrigeration consumes substantial amounts of energy. However, due to the thermal capacity of the refrigerated goods, parts of the cooling capacity delivered can be shifted in time without deteriorating the food quality. In this study, we develop a realistic model for the energy...... consumption in super market refrigeration systems. This model is used in a Nonlinear Model Predictive Controller (NMPC) to minimise the energy used by operation of a supermarket refrigeration system. The model is non-convex and we develop a computational efficient algorithm tailored to this problem...

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

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Larsen, Lars F. S.

    2011-01-01

    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......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...... 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...

  5. Modeling Supermarket Refrigeration Systems for Demand-Side Management

    Directory of Open Access Journals (Sweden)

    Jakob Stoustrup

    2013-02-01

    Full Text Available Modeling of supermarket refrigeration systems for supervisory control in the smart grid is presented in this paper. A modular modeling approach is proposed in which each module is modeled and identified separately. The focus of the work is on estimating the power consumption of the system while estimating the cold reservoir temperatures as well. The models developed for each module as well as for the overall integrated system are validated by real data collected from a supermarket in Denmark. The results show that the model is able to estimate the actual electrical power consumption with a high fidelity. Moreover a simulation benchmark is introduced based on the produced model for demand-side management in smart grid. Finally, a potential application of the proposed benchmark in direct control of the power/energy consumption is presented by a simple simulation example.

  6. Performance Assessment and Active System Monitoring for Refrigeration Systems

    DEFF Research Database (Denmark)

    Green, Torben

    to the refrigeration system, is to optimise the total cost of ownership, (TCO). However, directly measuring TCO provides some challenges. It can therefore be beneficial to divide TCO into performance criteria, which can be quantied and measured. For supermarket refrigeration systems the performance criteria can...... is measure by the switch frequency of the compressors in the refrigeration system. The reason is that excessive compressor switching will wear down the compressors too fast and thereby decrease the reliability of the system due to a higher demand for maintenance. The proposed performance function provides...

  7. Development of 18 K helium refrigeration system for CERN

    CERN Document Server

    CERN. Geneva

    2004-01-01

    The Conseil Europeen pour Ia Recherche Nucleaire (CERN) placed an order for a 1.8 K helium refrigeration system with IHI for the Large Hadron Collider project in 1999. IHI formed a consortium with Linde Kryotechnik AG (Switzerland), which has long experience with helium refrigeration systems. IHI designed and manufactured cold compressors based on leading technologies and expertise for turbo machinery. The cold compressor has the highest efficiency in the world. This paper describes the 1.8 K helium refrigeration system and performance test results at CERN. (5 refs).

  8. Dilution refrigeration with multiple mixing chambers

    International Nuclear Information System (INIS)

    Coops, G.M.

    1981-01-01

    A dilution refrigerator is an instrument to reach temperatures in the mK region in a continuous way. The temperature range can be extended and the cooling power can be enlarged by adding an extra mixing chamber. In this way we obtain a double mixing chamber system. In this thesis the theory of the multiple mixing chamber is presented and tested on its validity by comparison with the measurements. Measurements on a dilution refrigerator with a circulation rate up to 2.5 mmol/s are also reported. (Auth.)

  9. CO2LD: An innovation educational project for High Degree Professional Training in Refrigeration

    Directory of Open Access Journals (Sweden)

    Ramon Cabello Lopez

    2013-12-01

    Full Text Available Refrigeration is one of the technology sectors which has suffered most changes in the last twenty years, because of the negative impact of the fluids used in the refrigeration cycles, the refrigerants, due to their impact in the ozone layer and the promotion of the global warming. Due to the negative impacts of the fluids, the European Union has established several directives to restrict the use of refrigerant fluids, causing the need of adaptation of the sector to the new regulations. The adaptation of the refrigeration sector to the new regulations must be done by all agents involved, included the training and education of the future refrigeration technicians. To allow this, the project CO2LD has been developed to introduce the future technology in the High Degree Professional Training in Refrigeration. The objective of the project consisted on introducing more efficient and more sustainable refrigeration systems, R134a/CO2 cascade cycles, in the studies of High Degree Professional Training in Refrigeration, and create a collaborative framework among students, secondary-schools, refrigeration technicians, refrigeration companies and the University to facilitate the know-how transfer. This paper presents the objectives of the project, describes its development and analyses the main conclusions of it.

  10. Dynamics of gas bubble growth in oil-refrigerant mixtures under isothermal decompression

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Joao Paulo; Barbosa Junior, Jader R.; Prata, Alvaro T. [Federal University of Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. of Mechanical Engineering], Emails: jpdias@polo.ufsc.br, jrb@polo.ufsc.br, prata@polo.ufsc.br

    2010-07-01

    This paper proposes a numerical model to predict the growth of gaseous refrigerant bubbles in oil-refrigerant mixtures with high contents of oil subjected to isothermal decompression. The model considers an Elementary Cell (EC) in which a spherical bubble is surrounded by a concentric and spherical liquid layer containing a limited amount of dissolved liquid refrigerant. The pressure reduction in the EC generates a concentration gradient at the bubble interface and the refrigerant is transported to the bubble by molecular diffusion. After a sufficiently long period of time, the concentration gradient in the liquid layer and the bubble internal pressure reach equilibrium and the bubble stops growing, having attained its stable radius. The equations of momentum and chemical species conservation for the liquid layer, and the mass balance at the bubble interface are solved via a coupled finite difference procedure to determine the bubble internal pressure, the refrigerant radial concentration distribution and the bubble growth rate. Numerical results obtained for a mixture of ISO VG10 ester oil and refrigerant HFC-134a showed that bubble growth dynamics depends on model parameters like the initial bubble radius, initial refrigerant concentration in the liquid layer, decompression rate and EC temperature. Despite its simplicity, the model showed to be a potential tool to predict bubble growth and foaming which may result from important phenomena occurring inside refrigeration compressors such as lubrication of sliding parts and refrigerant degassing from the oil stored in oil sump during compressor start-up. (author)

  11. Parametric analysis and optimization for a combined power and refrigeration cycle

    International Nuclear Information System (INIS)

    Wang Jiangfeng; Dai Yiping; Gao Lin

    2008-01-01

    A combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the absorption refrigeration cycle. This combined cycle uses a binary ammonia-water mixture as the working fluid and produces both power output and refrigeration output simultaneously with only one heat source. A parametric analysis is conducted to evaluate the effects of thermodynamic parameters on the performance of the combined cycle. It is shown that heat source temperature, environment temperature, refrigeration temperature, turbine inlet pressure, turbine inlet temperature, and basic solution ammonia concentration have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. A parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The optimized exergy efficiency is 43.06% under the given condition

  12. Acoustic field characteristics and performance analysis of a looped travelling-wave thermoacoustic refrigerator

    International Nuclear Information System (INIS)

    Jin, T.; Yang, R.; Wang, Y.; Feng, Y.; Tang, K.

    2016-01-01

    Highlights: • Key issues for a highly efficient thermoacoustic conversion are analyzed. • A looped thermoacoustic refrigerator with one engine stage and one refrigerator stage is proposed. • Effective refrigeration powered by heat sources below 250 °C is demonstrated in the simulation. • Impact of cooling/heating temperatures on system performance is analyzed in view of acoustic field. - Abstract: This paper focuses on a looped travelling-wave thermoacoustic refrigerator powered by thermal energy. Based on a simplified model for the regenerator, key issues for a highly efficient thermoacoustic conversion, including both thermal-to-acoustic and heat-pumping processes, are summarized. A looped travelling-wave thermoacoustic refrigerator with one engine stage and one refrigerator stage is proposed, with emphasis on high normalized acoustic impedance, sufficient volumetric velocity and appropriate phase relation close to travelling wave in the regenerators of both engine and refrigerator. Simulation results indicate that for the ambient temperature of 30 °C, the looped travelling-wave thermoacoustic refrigerator can be powered by the heat at 210–250 °C to achieve the refrigeration at −3 °C with the overall coefficient of performance above 0.4 and the relative Carnot coefficient of performance over 13%. The characteristics of the acoustic field inside the loop configuration are analyzed in detail to reveal the operation mechanism of the looped travelling-wave thermoacoustic refrigerator. Additional analyses are conducted on the impact of the cooling and the heating temperatures, which are of great concern to the refrigeration applications and the utilization of low-grade thermal energy.

  13. Saving 50% of energy in air conditioning and refrigeration; 50% de ahorro de energia en aire acondicionado y refrigeracion

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez De la Fuente, Rodolfo Javier [Instituto para la Proteccion Ambiental de Nuevo Leon-CAINTRA, Nuevo Leon (Mexico); Bolado Tamez, Jaime Antonio [Industrias AlEn S. A. de C. V., Monterrey (Mexico)

    1998-12-31

    Due to the fact that the air conditioning systems represent up to 70% of the energy consumption in our buildings, to the constant raise of the electric tariffs and to the increment of temperatures in Nuevo Leon State, as well as the restrictions on the use of some refrigerant fluids because of its potential damage to the ozone layer (Montreal Protocol) and the preferential use of refrigerants with low global heating potential (Kioto Protocol). The Camara de la Industria de la Transformacion de Nuevo Leon (Nuevo Leon`s Transformation Industry Chamber) through the Instituto para la Proteccion Ambiental de Nuevo Leon (Nuevo Leon`s Institute for Environmental Protection), create the program ECO-REFRIGERATION whose three missions are: Increase the efficiency of air conditioning and refrigeration equipment, promote the substitution of refrigerants and extend the benefits of these projects to the community in general. [Espanol] Debido a que los sistemas de climatizacion representan hasta el 70% de consumo energetico en nuestros inmuebles, al constante incremento de las tarifas electricas, el incremento de las temperaturas en Nuevo Leon, asi como la restriccion del uso de algunos refrigerantes por su potencial de dano de la capa de ozono (Protocolo de Montreal) y el uso preferente de refrigerantes con bajo potencial de calentamiento global (Protocolo de Kioto), la Camara de la Industria de la Transformacion de Nuevo Leon a traves del Instituto para la Proteccion Ambiental de Nuevo Leon crean el Programa ECO-REFRIGERACION cuyas tres misiones son: Incrementar la eficiencia de los equipos de aire acondicionado y refrigeracion, promover la sustitucion de refrigerantes y extender los beneficios de este proyecto a la comunidad en general.

  14. Saving 50% of energy in air conditioning and refrigeration; 50% de ahorro de energia en aire acondicionado y refrigeracion

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez De la Fuente, Rodolfo Javier [Instituto para la Proteccion Ambiental de Nuevo Leon-CAINTRA, Nuevo Leon (Mexico); Bolado Tamez, Jaime Antonio [Industrias AlEn S. A. de C. V., Monterrey (Mexico)

    1999-12-31

    Due to the fact that the air conditioning systems represent up to 70% of the energy consumption in our buildings, to the constant raise of the electric tariffs and to the increment of temperatures in Nuevo Leon State, as well as the restrictions on the use of some refrigerant fluids because of its potential damage to the ozone layer (Montreal Protocol) and the preferential use of refrigerants with low global heating potential (Kioto Protocol). The Camara de la Industria de la Transformacion de Nuevo Leon (Nuevo Leon`s Transformation Industry Chamber) through the Instituto para la Proteccion Ambiental de Nuevo Leon (Nuevo Leon`s Institute for Environmental Protection), create the program ECO-REFRIGERATION whose three missions are: Increase the efficiency of air conditioning and refrigeration equipment, promote the substitution of refrigerants and extend the benefits of these projects to the community in general. [Espanol] Debido a que los sistemas de climatizacion representan hasta el 70% de consumo energetico en nuestros inmuebles, al constante incremento de las tarifas electricas, el incremento de las temperaturas en Nuevo Leon, asi como la restriccion del uso de algunos refrigerantes por su potencial de dano de la capa de ozono (Protocolo de Montreal) y el uso preferente de refrigerantes con bajo potencial de calentamiento global (Protocolo de Kioto), la Camara de la Industria de la Transformacion de Nuevo Leon a traves del Instituto para la Proteccion Ambiental de Nuevo Leon crean el Programa ECO-REFRIGERACION cuyas tres misiones son: Incrementar la eficiencia de los equipos de aire acondicionado y refrigeracion, promover la sustitucion de refrigerantes y extender los beneficios de este proyecto a la comunidad en general.

  15. 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.

  16. Growth strategies of electric utilities in context of deregulation and liberalization of electricity market

    Directory of Open Access Journals (Sweden)

    Maria Đogić

    2017-01-01

    Full Text Available This paper identifies the growth strategies adopted by the electric utilities sector in the context of changes resulting from the deregulation and liberalization of the electricity market. Strategies pursued by the electric utilities sector were rarely the subject of research in the field of strategic management despite the fact that electricity is an indispensable element of everyday life and the economy as a whole. Therefore, a case study of the largest incumbent electric utilities in the Republic of Croatia, Slovenia, Bosnia and Herzegovina, Serbia, Montenegro, and Macedonia has been conducted, and differences in the degree of market liberalization and core features of these companies have been noted. Research findings have shown that the degree of deregulation can affect the growth strategies of electric utilities. In those countries where the degree of deregulation is lower, electric utilities focus on the domestic market. On the other hand, a higher level of deregulation enables electric utilities to achieve their growth through diversification or innovation. Given the fact that the analyzed electric utilities are operating within relatively small economies, they cannot compete with electric utilities in developed countries, and, apart from international electricity trading, are mostly focused on their domestic markets.

  17. Electricity savings ``soon come'' to Jamaica -- Assessing the potential for air conditioning and refrigeration end-use DSM

    Energy Technology Data Exchange (ETDEWEB)

    Conlon, T.; Hamzawi, E.; Campbell, V.

    1998-07-01

    With the support of the Inter-American Development Bank, the Global Environment Facility of the World Bank, and the Rockefeller Foundation, the national electric utility in Jamaica (Jamaica Public Service Company) has begun an assessment of the technical, economic, and financial opportunities for achieving demand-side management (DSM) energy savings in the air conditioning and refrigeration end uses. The feasibility and cost effectiveness of specific measures is being assessed for both the residential and commercials segments. While structures as a traditional load-research-based market assessment, the project uses ethnographic data collection and analysis techniques and involves collaboration with local contractors. The skills of local experts are being taped to identify and interview the key market players, and to develop an understanding of the barriers to and opportunities for energy efficiency present in the evolving equipment markets. The paper outlines methods and presents preliminary case study results for the air conditioning market. The authors identify major groups of market players and dominant types of equipment, and provide an overview of market dynamics. The volume of sales passing through both formal and informal distribution channels is estimated and market barriers are identified. Based on the findings of the study, recommendations will be made for future program and policy initiatives designed to mitigate selected barriers in each of the supply chains.

  18. Commercial refrigeration - An overview of current status

    OpenAIRE

    Mota Babiloni, Adrián; Navarro Esbri, Joaquin; BARRAGÁN CERVERA, ÁNGEL; Moles, Francisco; Peris, Bernardo; Verdú Martín, Gumersindo Jesús

    2015-01-01

    Commercial Refrigeration comprises food freezing and conservation in retail stores and supermarkets, so, it is one of the most relevant energy consumption sectors, and its relevance is increasing. This paper reviews the most recent developments in commercial refrigeration available in literature and presents a good amount of results provided these systems, covering some advantages and disadvantages in systems and working fluids. Latest researches are focused on energy savings to reduce CO2 in...

  19. Redesign 3 R Machine as a Refrigerant Waste Treatment Alternative in Environmental Rescue

    Science.gov (United States)

    Negara, I. P. S.; Arsawan, I. M.

    2018-01-01

    Cooling machine technologies really affect nowadays’ modern life, not only limited in enhancement of life quality and comfort, but it has also reached the essential things of humans’ life supporter (Arora, 2001). Cooling machine technologies have direct contribution toward environmental damage such as depletion of ozone layer and global warming through synthetic refrigerant waste and leakage (CFC and HFC) to environment. The refrigerant release to the environment is 60% of the service sector. Destructive characteristics of ozone possessed by CFC were first proposed by Rowland and Molina which were then supported by yard measurement. It is estimated that ozone layer damage occurs for about 3% every decade. The ozone layer located in the stratosphere is functioned to prevent ultraviolet-B ray from entering into earth surface. This Ultraviolet-B is suspected to be the cause of health problem for humans and disorder for plants on earth. As for the purpose of this research is to obtain a product design of refrigerant waste processing system (recovery and recycle refrigerant) as well as to acknowledge the work method (COP) of cooling machines that use CFC refrigerant (R-12) as the result of recovery and recycle compared to CFC refrigerant (R-12)/pure R134a. One method that can be used is by redesigning existing equipment namely 3R machine that cannot be used anymore thus it can be reused. This research will be conducted through modifying the existing 3R machine therefore it can be reused and be easily operated as well as doing the maintenance, after that the refrigerant as the result of recovery will be tried on a refrigeration system and a test of refrigeration system work method will be conducted by using the refrigerant recycle product which is obtained and compared with the work method of the one with pure refrigeration.The result has been achieved that the redesign product of refrigerant waste processing equipment can be reused and able to perform the recovery

  20. Report on the draft of the law No. 1253 concerning the Revamping and Expanding Domestic Electricity Supply. Volume I. General discussion and Examination of the articles; Rapport sur le projet de loi (no. 1253) relatif a la modernisation et au developpement du service public de l'electricite. Tome I. Discussion generale et Examen des articles

    Energy Technology Data Exchange (ETDEWEB)

    Bataille, Christian [Assemblee Nationale, Paris (France)

    1999-02-11

    This report on the draft of the law No. 1253 concerning the Revamping and Expanding Domestic Electricity Supply is composed of three parts. The first part contains the following three sections: I. The electricity, a commodity as others?; II. The stride towards liberalization; III. France and the opening of electricity market. In turn, the first section addresses the following two subjects: A. The 'classic' approach or recognizing the peculiarity of electricity; B. The European approach or the trend of trivializing the electricity. The second section addresses the subjects titled: A. A long and severe bargaining; B. Directive 96/92/CE of 19 December 1996, a new step in achieving a domestic market of electricity; C. The stage of implementation throughout the member states. The third section presents the current juridical framework and the main problems stipulated in the draft of the law concerning the Revamping and Expanding Domestic Electricity Supply. The second part of this report is devoted to the debates in the Commission of Production and Exchanges and contains the following three sections: I. Auditions; II. General discussion; III. The examination of the articles of the law concerning the Revamping and Expanding Domestic Electricity Supply.

  1. Contribution of domestic industry to the spanish nuclear program

    International Nuclear Information System (INIS)

    Palacios, L.

    1987-01-01

    The incorporation of nuclear energy to the spanish electricity supply system dates back to the 1960's, when the industrial infrastructure of the country was being modernized. The first round of Nuclear Power Plants was ordered on a turnkey basis from foreign established vendors and the participation of domestic suppliers of mechanical and electrical equipment was smaller than that of engineering, construction and erection companies. The 1960's and early 1970's witnessed a high rate of growth in electricity consumption. This fact plus the scarcity of domestic energy resources prompted an ambitious energy plan with a strong nuclear component. A second round of non-turnkey orders was placed by the Spanish utilities. Spanish industry, on the basis of a reliable market and the government guidelines to increase substantially the domestic participation, launched a determined effort to reorganize its activities to produce high quality, competitive components. The main thrust of this effort was directed to creating quality asurance systems, assimilating construction codes such as ASME Section III and realizing some investment in equipment and acquisition of manufacturing knowhow. Existing plants were largely used. A third round of plants was ordered during the 1970's for which full participation was targeted. During this phase this industrial infrastructure was completed with some new plants (for primary components and fuel fabrication) and a host of smaller, specialized firms for parts and services. The present situation is one of maturity in the design and manufacturing capacity for most components, with the exception of some raw materials and specialized items for which the economic threshold far exceeds the domestic needs... (author)

  2. Helium refrigerator for 'SULTAN'

    International Nuclear Information System (INIS)

    Arpagaus, M.; Erlach, H.; Quack, H.

    1984-01-01

    The authors describe the helium refrigerator designed for the SULTAN test facility. SULTAN (Supraleiter-Testanlage) is intended to serve for the developments and testing of high field superconducting magnets. These magnets are needed mainly for future applications in nuclear fusion. (Auth.)

  3. The UK-DALE dataset, domestic appliance-level electricity demand and whole-house demand from five UK homes

    Science.gov (United States)

    Kelly, Jack; Knottenbelt, William

    2015-03-01

    Many countries are rolling out smart electricity meters. These measure a home’s total power demand. However, research into consumer behaviour suggests that consumers are best able to improve their energy efficiency when provided with itemised, appliance-by-appliance consumption information. Energy disaggregation is a computational technique for estimating appliance-by-appliance energy consumption from a whole-house meter signal. To conduct research on disaggregation algorithms, researchers require data describing not just the aggregate demand per building but also the ‘ground truth’ demand of individual appliances. In this context, we present UK-DALE: an open-access dataset from the UK recording Domestic Appliance-Level Electricity at a sample rate of 16 kHz for the whole-house and at 1/6 Hz for individual appliances. This is the first open access UK dataset at this temporal resolution. We recorded from five houses, one of which was recorded for 655 days, the longest duration we are aware of for any energy dataset at this sample rate. We also describe the low-cost, open-source, wireless system we built for collecting our dataset.

  4. Exergy analysis of vapor compression refrigeration cycle with two-stage and intercooler

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, Bayram [Mehmet Akif Ersoy University, Bucak Emin Guelmez Vocational School, Bucak, Burdur (Turkey)

    2012-07-15

    In this study, exergy analyses of vapor compression refrigeration cycle with two-stage and intercooler using refrigerants R507, R407c, R404a were carried out. The necessary thermodynamic values for analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total irreversibility rate of the system in the different operating conditions for these refrigerants were investigated. The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were compared. (orig.)

  5. Automotive exhaust gas flow control for an ammonia–water absorption refrigeration system

    International Nuclear Information System (INIS)

    Rêgo, A.T.; Hanriot, S.M.; Oliveira, A.F.; Brito, P.; Rêgo, T.F.U.

    2014-01-01

    A considerable part of the energy generated by an automotive internal combustion engine is wasted as heat in the exhaust system. This wasted heat could be recovered and applied to power auxiliary systems in a vehicle, contributing to its overall energy efficiency. In the present work, the experimental analysis of an absorption refrigeration system was performed. The exhaust system of an automotive internal combustion engine was connected to the generator element of an absorption refrigeration system. The performance of the absorption refrigerator was evaluated as a function of the supplied heat. The use of a control strategy for the engine exhaust gas mass flow rate was implemented to optimize the system. Exhaust gas flow was controlled by step-motor actuated valves commanded by a microcontroller in which a proportional-integral control scheme was implemented. Information such as engine torque, speed, key temperatures in the absorption cycle, as well as internal temperatures of the refrigerator was measured in a transient regime. The results indicated that the refrigeration system exhibited better performance when the amount of input heat is controlled based on the temperature of the absorption cycle generator. It was possible to conclude that, by dynamically controlling the amount of input heat, the utilisation range of the absorption refrigeration system powered by exhaust gas heat could be expanded in order to incorporate high engine speed operating conditions. - Highlights: •An absorption refrigerator was driven by automotive exhaust gas heat. •A system for controlling the refrigeration system heat input was developed. •Excessive exhaust gas heat leads to ineffective operation of the refrigerator. •Control of refrigerator's generator temperature led to better performance. •The use of exhaust gas was possible for high engine speeds

  6. The experimental investigation of refrigerant distribution and leaking characteristics of R290 in split type household air conditioner

    International Nuclear Information System (INIS)

    Tang, Weier; He, Guogeng; Cai, Dehua; Zhu, Yihao; Zhang, Aoni; Tian, Qiqi

    2017-01-01

    Highlights: • A new quasi-liquid nitrogen method (QLNM) was proposed and firstly applied in experiments. • The R290 distribution was investigated by QLNM and the results proved the validation. • A solenoid valve was proposed to install near the capillary in STHAC in order to reduce risk factor. • R290 leaking rate was firstly measured by QLNM before and after the installation a solenoid valve. - Abstract: As a high-profile replacement for R22 split type household air conditioner (STHAC), R290 has several advantages in terms of thermodynamic properties, environmental characteristics, and cost. However, the obvious shortcoming of R290 is its flammability, which has a potential fire risk to the building. At present, the most important measure to ensure the safety of a R290 STHAC is to limit the refrigerant charge by domestic and international standards. But in fact, when the leakage of R290 occur from a STHAC, the distribution of R290 in STHAC, and the leaking rate also will seriously affect the safety of an R290 STHAC. In this study, a new quasi-liquid nitrogen method (QLNM) has been proposed in order to investigate the refrigerant distribution in R290 STHACs and the leaking rate under various conditions, and the experiments have been conducted. The experimental results of distribution proved the validation of the QLNM and showed that a large portion of the refrigerant distributed in the condenser when the air conditioner is on running stage and the refrigerant will migrate from the condenser to the evaporator when the air conditioner is on closed stage. Based on this, the installation of a solenoid valve near the capillary has been proposed. The comparison of experimental results of R290 leaking rate before and after the installation of a solenoid valve showed it will obviously reduce the leaking rate and thereby improve the safety of the R290 STHACs.

  7. Effects of hysteresis and Brayton cycle constraints on magnetocaloric refrigerant performance

    Science.gov (United States)

    Brown, T. D.; Buffington, T.; Shamberger, P. J.

    2018-05-01

    Despite promising proofs of concept, system-level implementation of magnetic refrigeration has been critically limited by history-dependent refrigerant losses that interact with governing thermodynamic cycles to adversely impact refrigeration performance. Future development demands a more detailed understanding of how hysteresis limits performance, and of how different types of cycles can mitigate these limitations, but without the extreme cost of experimental realization. Here, the utility of Brayton cycles for magnetic refrigeration is investigated via direct simulation, using a combined thermodynamic-hysteresis modeling framework to compute the path-dependent magnetization and entropy of a model alloy for a variety of feasible Brayton cycles between 0-1.5 T and 0-5 T. By simultaneously varying the model alloy's hysteresis properties and applying extensions of the thermodynamic laws to non-equilibrium systems, heat transfers and efficiencies are quantified throughout the space of hystereses and Brayton cycles and then compared with a previous investigation using Ericsson cycles. It is found that (1) hysteresis losses remain a critical obstacle to magnetic refrigeration implementation, with efficiencies >80% in the model system requiring hysteresis refrigerant transformation temperatures at the relevant fields; (3) for a given hysteresis and field constraint, Brayton and Ericsson-type cycles generate similar efficiencies; for a given temperature span, Ericsson cycles lift more heat per cycle, with the difference decreasing with the refrigerant heat capacity outside the phase transformation region.

  8. Modular Modelling and Simulation Approach - Applied to Refrigeration Systems

    DEFF Research Database (Denmark)

    Sørensen, Kresten Kjær; Stoustrup, Jakob

    2008-01-01

    This paper presents an approach to modelling and simulation of the thermal dynamics of a refrigeration system, specifically a reefer container. A modular approach is used and the objective is to increase the speed and flexibility of the developed simulation environment. The refrigeration system...

  9. Magnetic refrigeration down to 1.6 K for the future circular collider e$^+$e$^-$

    CERN Document Server

    Tkaczuk, Jakub; Millet, Francois; Rousset, Bernard; Duval, Jean Marc

    2017-01-01

    High-field superconducting rf cavities of the future circular collider e+e− may require a kW-range superfluid helium refrigeration down to 1.6 K. Magnetic refrigeration operating below 4.2 K can be an alternative to the compression/expansion helium refrigeration. A significant difference between this application and previous magnetic refrigerator studies is its large cooling power, up to 103 times larger than the other designs. Principles of magnetic refrigeration are described and various technical solutions are compared. A numerical model for the static magnetic refrigerator is presented, validated, and adapted to the needs of the positron-electron version of the future circular collider. A preliminary design of magnetic refrigerator suitable for low temperature, kW-range cooling is studied.

  10. 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.

  11. Superfluid thermodynamic cycle refrigerator

    Science.gov (United States)

    Swift, Gregory W.; Kotsubo, Vincent Y.

    1992-01-01

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

  12. Flammability Indices for Refrigerants

    Science.gov (United States)

    Kataoka, Osami

    This paper introduces a new index to classify flammable refrigerants. A question on flammability indices that ASHRAE employs arose from combustion test results of R152a and ammonia. Conventional methods of not only ASHRAE but also ISO and Japanese High-pressure gas safety law to classify the flammability of refrigerants are evaluated to show why these methods conflict with the test results. The key finding of this paper is that the ratio of stoichiometric concentration to LFL concentration (R factor) represents the test results most precisely. In addition, it has excellent correlation with other flammability parameters such as flame speed and pressure rise coefficient. Classification according to this index gives reasonable flammability order of substances including ammonia, R152a and carbon monoxide. Theoretical background why this index gives good correlation is also discussed as well as the insufficient part of this method.

  13. 2014 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte- und Klimatagung 2014. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The proceedings of the 2014 German refrigeration and air conditioning meeting contain contributions on the following topics: cryotechnology, fundamentals and materials for the refrigeration and heat pump technology, devices and components for the refrigeration and heat pump technology, applications of refrigeration technologies, air conditioning technology and heat pump applications, cryotechnology in biology and medicine, heat transfer and ventilation, guidelines and legal topics, refrigerant fluid - oil mixtures, control and surveillance, simulation and control, ambient air.

  14. A Cold Cycle Dilution Refrigerator for Space Applications, Phase I

    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....

  15. Domestic wastes: assault course

    International Nuclear Information System (INIS)

    Durand, C.; Bergey, J.L.

    1997-01-01

    In the management of domestic waste, some incoherencies persist. The tax on waste is always 20.6% instead of 5.5% for water or transport. The price of buying back electric power by Electricite de France is too low according to the appreciation of the cogeneration club. Regarding to the sell of stream to industrial, stream buyers are not always reliable, no enough guarantee are given by them to allow to cogeneration club to invest. (N.C.)

  16. Greenhouse gas emissions for refrigerant choices in room air conditioner units.

    Science.gov (United States)

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

    2012-12-04

    In this work, potential replacement refrigerants for window-mounted room air conditioners (RACs) in the U.S. have been evaluated using a greenhouse gas (GHG) emissions analysis. CO(2)-equivalent emissions for several hydrofluoroethers (HFEs) and other potential replacements were compared to the most widely used refrigerants today. Included in this comparison are pure refrigerants that make up a number of hydrofluorocarbon (HFC) mixtures, pure hydrocarbons, and historically used refrigerants such as propane and ammonia. GHG emissions from direct and indirect sources were considered in this thermodynamic analysis. Propylene, dimethyl ether, ammonia, R-152a, propane, and HFE-152a all performed effectively in a 1 ton window unit and produced slightly lower emissions than the currently used R-22 and R-134a. The results suggest that regulation of HFCs in this application would have some effect on reducing emissions since end-of-life emissions remain at 55% of total refrigerant charge despite EPA regulations that mandate 80% recovery. Even so, offsite emissions due to energy generation dominate over direct GHG emissions and all the refrigerants perform similarly in totals of indirect GHG emissions.

  17. Cogen-absorption plants for refrigeration purposes and turbine air inlet cooling

    Energy Technology Data Exchange (ETDEWEB)

    Langreck, Juergen [Colibri bv (Netherlands)

    2000-04-01

    Most cogeneration systems produce power and heat but with absorption refrigeration plants (ARP) the products are power and 'cold'. An ARP driven by heat from a turbine exhaust can provide the cooling for the inlet air with very low consumption of electricity, consequently there is a significant increase in power output from the cogeneration unit. Two different ARP systems are currently available but the author describes only the ammonia-water system, which can achieve temperatures down to -60 degrees C. The article discusses the principle behind ARP, the capital cost and returns on investment, how the cogeneration plant is linked to the ARP, ARP for turbine inlet air cooling, and the potential applications of cogeneration-ARP.

  18. Design of a large 2.0 k refrigerator for CEBAF

    International Nuclear Information System (INIS)

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

    1991-01-01

    The CEBAF refrigerator is designed to produce 4,620 watts of refrigeration at 2.0 K, another 180 watts at 2.14 K plus 4.5 K liquid and higher temperature cooling for shields. Several design features are described, including a modular concept for the 2 K and 4.5 K refrigerator sections and the use of multistage centrifugal cryogenic compressors to achieve the 2 K. The development program for the centrifugal cryogenic compressors is discussed. Some startup information is also provided

  19. Investigation of an experimental ejector refrigeration machine operating with refrigerant R245fa at design and off-design working conditions. Part 1. Theoretical analysis

    KAUST Repository

    Shestopalov, K.O.

    2015-07-01

    © 2015 Elsevier Ltd and IIR.All rights reserved. The ejector refrigeration machine (ERM) offers several advantages over other heat-driven refrigeration machine, including simplicity in design and operation, high reliability and low installation cost, which enable its wide application in the production of cooling. In this paper the theoretical analysis of ejector design and ejector refrigeration cycle performance is presented. It is shown that ERM performance characteristics depend strongly on the operating conditions, the efficiency of the ejector used, and the thermodynamic properties of the refrigerant used. A 1-D model for the prediction of the entrainment ratio ω, and an optimal design for ejectors with cylindrical and conical-cylindrical mixing chambers are presented in this paper. In order to increase ERM performance values, it is necessary first of all to improve the performance of the ejector.

  20. New class of microminiature Joule — Thomson refrigerator and vacuum package

    Science.gov (United States)

    Paugh, Robert L.

    1990-12-01

    Progress is reported on the development of a two-stage, fast cooldown Joule — Thomson refrigerator using nitrogen gas and a nitrogen — hydrocarbon gas mixture as the refrigerants. The refrigerator incorporates a microminiature Venturi pump to reduce the pressure of the exhaust of the main boiler to bring the operating temperature of the cold stage to < 70 K in as little as 10 s. The vacuum package for the refrigerator contains no organic materials and is designed to provide a ten year shelf life. Special glass strengthening techniques are being used to achieve cooler survival of acceleration tests of up to 100 000g.