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Sample records for adsorption refrigerator powered

  1. Structure optimization and performance experiments of a solar-powered finned-tube adsorption refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • New-structure finned-tube adsorption bed for enhancing heat and mass transfer. • Temperatures on different parts of the adsorption tubes differ little. • Maximum COP of 0.122 and maximum daily ice-making of 6.5 kg are achieved by experiments. • Cooling efficiency of system with valve control higher than that without valve control. - Abstract: A large-diameter aluminum-alloy finned-tube absorbent bed collector was designed and optimized by enhancing the heat and mass transfer in the collector. The collection efficiency of the adsorbent bed collector was between 31.64% and 42.7%, and the temperature distribution in the absorbent bed was relatively uniform, beneficial to adsorption/desorption of the adsorbate in the absorbent bed. A solar-powered solid adsorption refrigeration system with the finned-tube absorbent bed collector was built. Some experiments corresponding to the adsorption/desorption process with and without a valve control were conducted in four typical weather conditions: sunny with clear sky, sunny with partly cloudy sky, cloudy sky and overcast sky. Activated carbon–methanol was utilized as the working pair for adsorption refrigeration in the experiments. The experiments achieved the maximum COP of 0.122 and the maximum daily ice-making of 6.5 kg. Under the weather conditions of sunny with clear sky, sunny with partly cloudy sky, and cloudy sky, ice-making phenomenon were observed. Even in the overcast-sky weather condition, the cooling efficiency of the system still reached 0.039 when the total solar radiation was 11.51 MJ. The cooling efficiency of the solar-powered adsorption refrigeration system with a valve control in the adsorption/desorption process was significantly higher than that without a valve control

  2. Study of a new solar adsorption refrigerator powered by a parabolic trough collector

    Energy Technology Data Exchange (ETDEWEB)

    El Fadar, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco); Mimet, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco)], E-mail: mimet@fst.ac.ma; Azzabakh, A. [Energetic Laboratory, Sciences Faculty, BP 2121, 93000 Tetouan, Abdelmalek Essaadi University (Morocco); Perez-Garcia, M. [Dpto. de Fisica Aplicada - Universidad de Almeria (Spain); Castaing, J. [Laboratoire Thermique, Energetique et Procedes (LaTEP), Avenue de l' Universite, BP 1155, 64013 Pau Cedex (France)

    2009-04-15

    This paper presents the study of solar adsorption cooling machine, where the reactor is heated by a parabolic trough collector (PTC) and is coupled with a heat pipe (HP). This reactor contains a porous medium constituted of activated carbon, reacting by adsorption with ammonia. We have developed a model, based on the equilibrium equations of the refrigerant, adsorption isotherms, heat and mass transfer within the adsorbent bed and energy balance in the hybrid system components. From real climatic data, the model computes the performances of the machine. In comparison with other systems powered by flat plate or evacuated tube collectors, the predicted results, have illustrated the ability of the proposed system to achieve a high performance due to high efficiency of PTC, and high flux density of heat pipe.

  3. Thermodynamic analysis and theoretical study of a continuous operation solar-powered adsorption refrigeration system

    International Nuclear Information System (INIS)

    Due to the intermittent nature of the solar radiation, the day-long continuous production of cold is a challenge for solar-driven adsorption cooling systems. In the present study, a developed solar-powered adsorption cooling system is introduced. The proposed system is able to produce cold continuously along the 24-h of the day. The theoretical thermodynamic operating cycle of the system is based on adsorption at constant temperature. Both the cooling system operating procedure as well as the theoretical thermodynamic cycle are described and explained. Moreover, a steady state differential thermodynamic analysis is performed for all components and processes of the introduced system. The analysis is based on the energy conservation principle and the equilibrium dynamics of the adsorption and desorption processes. The Dubinin–Astakhov adsorption equilibrium equation is used in this analysis. Furthermore, the thermodynamic properties of the refrigerant are calculated from its equation of state. The case studied represents a water chiller which uses activated carbon–methanol as the working pair. The chiller is found to produce a daily mass of 2.63 kg cold water at 0 °C from water at 25 °C per kg of adsorbent. Moreover, the proposed system attains a cooling coefficient of performance of 0.66. - Highlights: • A new continuous operation solar-driven adsorption refrigeration system is introduced. • The theoretical thermodynamic cycle is presented and explained. • A complete thermodynamic analysis is performed for all components and processes of the system. • Activated carbon–methanol is used as the working pair in the case study

  4. Experimental study on solar-powered adsorption refrigeration cycle with activated alumina and activated carbon as adsorbent

    Directory of Open Access Journals (Sweden)

    Himsar Ambarita

    2016-03-01

    Full Text Available Typical adsorbent applied in solar-powered adsorption refrigeration cycle is activated carbon. It is known that activated alumina shows a higher adsorption capacity when it is tested in the laboratory using a constant radiation heat flux. In this study, solar-powered adsorption refrigeration cycle with generator filled by different adsorbents has been tested by exposing to solar radiation in Medan city of Indonesia. The generator is heated using a flat-plate type solar collector with a dimension of 0.5 m×0.5 m. Four cases experiments of solar-powered adsorption cycle were carried out, they are with generator filled by 100% activated alumina (named as 100AA, by a mixed of 75% activated alumina and 25% activated carbon (75AA, by a mixed of 25% activated alumina and 75% activated carbon (25AA, and filled by 100% activated carbon. Each case was tested for three days. The temperature and pressure history and the performance have been presented and analyzed. The results show that the average COP of 100AA, 75AA, 25AA, and 100AC is 0.054, 0.056, 0.06, and 0.074, respectively. The main conclusion can be drawn is that for Indonesian condition and flat-plate type solar collector the pair of activated carbon and methanol is the better than activated alumina.

  5. Adsorption refrigeration-green cooling driven by low grade thermal energy

    Institute of Scientific and Technical Information of China (English)

    WANG Ruzhu; WANG Liwei

    2005-01-01

    As a type of environmental benign refrigeration technology powered by low grade thermal energy, adsorption refrigeration have aroused more and more attention in recent years. In this paper, the research frontiers of adsorption refrigeration, including adsorbent, adsorption theory, heat recovery process, technology of adsorber, the research achievements, and the development achievements, are summarized. Typical systems for adsorption refrigeration research facing to applications in the recent years are presented. Future applications of adsorption refrigeration are analysed.

  6. 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

  7. Efficient adsorption refrigerators integrated with heat pipes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.Z. [Institute of Refrigeration and Cryogenics, School of Mechanical Engineering, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2008-03-15

    Several novel ideas to use heat pipes in adsorption water chiller or ice maker are presented in this paper. Experimental results have shown that the adsorption refrigerators are very efficient. The first example of such systems is a small scale silica gel-water adsorption water chiller with cooling power rated as 10 kW; the system could be powered by 60-100 C hot water, a cooling COP = 0.4 has been achieved when driven by 85 C hot water. This adsorption chiller has been used for solar powered air conditioner and also as the chiller for CCHP system. The second example is a silica gel-water adsorption room air conditioner powered by 80 C hot water. The system is very compact and is suggested for potential applications of micro CCHP system based on fuel cells. The system has a COP of over 0.3 and cooling power of about 1 kW. The third example is the use of split heat pipes to heat or cool the adsorber for making ice in fishing boats. The application of these technologies avoids the corrosion of adsorber at the heating phase by exhausted gases and at the cooling phase by seawater, and also has the advantage of high heat transfer performance. With such arrangement and careful considerations of the arrangement of wicks in heat pipes, and also the use of composite adsorbent (calcium chloride and activated carbon)-ammonia adsorption pair, the system test has shown the specific refrigeration power for more than 730 W/kg at -15 C. (author)

  8. Dynamic analysis of the CTAR (constant temperature adsorption refrigeration) cycle

    International Nuclear Information System (INIS)

    The basic SAR (solar-driven adsorption refrigeration) machine is an intermittent cold production system. Recently, the CO-SAR (continuous operation solar-powered adsorption refrigeration) system is developed. The CO-SAR machine is based on the theoretical CTAR (constant temperature adsorption refrigeration) cycle in which the adsorption process takes place at a constant temperature that equals the ambient temperature. Practically, there should be a temperature gradient between the adsorption bed and the surrounding atmosphere to provide a driving potential for heat transfer. In the present study, the dynamic analysis of the CTAR cycle is developed. This analysis provides a comparison between the theoretical and the dynamic operation of the CTAR cycle. The developed dynamic model is based on the D-A adsorption equilibrium equation and the energy and mass balances in the adsorption reactor. Results obtained from the present work demonstrate that, the idealization of the constant temperature adsorption process in the theoretical CTAR cycle is not far from the real situation and can be approached. Furthermore, enhancing the heat transfer between the adsorption bed and the ambient during the bed pre-cooling process helps accelerating the heat rejection process from the adsorption reactor and therefore approaching the isothermal process. - Highlights: • The dynamic analysis of the CTAR (constant temperature adsorption refrigeration) cycle is developed. • The CTAR theoretical and dynamic cycles are compared. • The dynamic cycle approaches the ideal one by enhancing the bed precooling

  9. Study on intermittent refrigeration phenomenon for solar solid adsorption refrigeration

    International Nuclear Information System (INIS)

    A valveless solar solid adsorption ice maker has been used for carrying out experiments under real solar radiation intensity conditions. Different performance variations of the solar ice maker are obtained under the effect of sky cloudy cover. The experimental results indicated that the performance of the solar ice maker was severely affected by the sky cloudy cover, and no ice would be obtained if cloudy conditions prevailed for intervals exceeding 3 h. A heat and mass transfer model validated by the experiments has been used to analyze intermittent refrigeration phenomenon of solar solid adsorption refrigeration. The performance variation due to the effecting of sky cloudy cover has also been demonstrated by simulated results. The analysis of both experimental and simulated results has provided an objective climate resource choice which could be available now in applications to solar solid refrigeration, it also has made a scientific analysis method for solar solid adsorption ice maker application

  10. Continuously operating dilution refrigerator with adsorption pumps

    International Nuclear Information System (INIS)

    The main parts and performance of two versions of the continuously operating dilution refrigerator with an adsorption pumping system dedicated to physical investigations at ultralow temperatures are described. Compared to conventional dilution refrigerators these versions are more compact, economic and more vibration proof. This type of dilution refrigerator allows a single shot operation to be realized. The minimum temperature reached in a single continuous heat exchanger refrigerator is 18 mK for a continuous operation and 5 - 8 mK for a single shot are. On addition of four discrete heat exchangers, the minimum temperature for continuous operation reduces down to 8 mK

  11. Solar powered adsorption refrigerator with CPC collection system: Collector design and experimental test

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Manuel I.; Rodriguez, Luis R. [Departamento de Fisica, Universidad de Burgos, Avda. Cantabria s/n, 09006 Burgos (Spain)

    2007-09-15

    Solar adsorption cooling systems are usually based on the flat plate collector, whereas little attention has been paid to concentrating collectors. Compound parabolic concentrators (CPC) are a versatile class of solar collectors that can be adapted to a large variety of applications and geometries. This work presents a CPC collector whose tubular receiver contains the sorption bed and where only a portion of the receiver is exposed to sunlight. Geometric characteristics of the proposed CPC, such as the profile, the length and the height of the reflective sheet are given. A prototype of a solar adsorption chiller using this type of collector and the activated carbon-methanol working pair is described, and typical experimental results are reported. In particular, the measured solar COP ranges from 0.078 to 0.096. (author)

  12. Influence of power source type on energy effectiveness and environmental impact of cooling system with adsorption refrigerator

    International Nuclear Information System (INIS)

    Highlights: • Sustainability development in industrial energy systems was studied. • Solar energy and waste heat for feeding of adsorption refrigerator were used. • Primary energy savings for cooling systems were examined. • Greenhouse gasses savings with renewable and non-renewable sources were estimated. - Abstract: In the paper the method for energy and ecological evaluation of refrigeration system based on the adsorption machine is presented. The energy effectiveness is calculated on the level of the primary energy consumption. The method for ecological evaluation is also discussed. In the ecological evaluation the influence on greenhouse gasses (GHG) is taken into account and the ecological effects are expressed as equivalent CO2 emission. The authors compare the effectiveness of a refrigerator existing in an example Polish food factory supplied with heat from a boiler house fired with natural gas, a cogeneration system and solar collectors. In the last case the climatic conditions and detailed solar radiation data for Poland have been used. The authors demonstrated that the application of cogeneration or renewable energy sources (RES) for the cooling system can lead to energy savings and ecological benefits. To measure the energy effects the authors introduced the following indices: (PES) – Primary Energy Savings and (GHGS) – Greenhouse Gasses Savings. The results of the mentioned indices for different configuration of heating systems are calculated and presented in the paper

  13. Solar Powered Refrigeration System

    Science.gov (United States)

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

    2002-01-01

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

  14. 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.

  15. Effect of Adsorbent Diameter on the Performance of Adsorption Refrigeration

    Institute of Scientific and Technical Information of China (English)

    黄宏宇; 何兆红; 袁浩然; 小林敬幸; 赵丹丹; 窪田光宏; 郭华芳

    2014-01-01

    Adsorbents are important components in adsorption refrigeration. The diameter of an adsorbent can af-fect the heat and mass transfer of an adsorber. The effect of particle diameter on effective thermal conductivity was investigated. The heat transfer coefficient of the refrigerant and the void rate of the adsorbent layer can also affect the effective thermal conductivity of adsorbents. The performance of mass transfer in the adsorber is better when pressure drop decreases. Pressure drop decreases with increasing permeability. The permeability of the adsorbent layer can be improved with increasing adsorbent diameter. The effect of adsorbent diameter on refrigeration output power was experimentally studied. Output power initially increases and then decreases with increasing diameter under different cycle time conditions. Output power increases with decreasing cycle time under similar diameters.

  16. Performance Prediction of Solar Adsorption Refrigeration System by Ann

    OpenAIRE

    Baiju, V.; C. Muraleedharan

    2012-01-01

    This paper proposes a new approach for the performance analysis of a single-stage solar adsorption refrigeration system with activated carbon-R134a as working pair. Use of artificial neural network has been proposed to determine the performance parameters of the system, namely, coefficient of performance, specific cooling power, adsorbent bed (thermal compressor) discharge temperature, and solar cooling coefficient of performance. The ANN used in the performance prediction was made in MATLAB ...

  17. 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.

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

    OpenAIRE

    Grzebielec Andrzej; Rusowicz Artur; Jaworski Maciej; Laskowski Rafał

    2015-01-01

    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 W...

  19. Regulating Power from Supermarket Refrigeration

    DEFF Research Database (Denmark)

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

    2014-01-01

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

  20. A study of the effects of collector and environment parameters on the performance of a solar powered solid adsorption refrigerator

    International Nuclear Information System (INIS)

    Based on the heat and mass transfer model validated by experiment, the performance of the plate solar ice-maker is analyzed systemically with the opinion of two-type characteristic parameters, which includes parametric effects of adsorbent bed of solar ice-maker and outer parameters referring to circumstance. A large number of simulations were undertaken to test the performance of the refrigerator for various collector design parameters and environmental parameters. These works are beneficial to further study the optimization design of a solar cooling system. (Author)

  1. Solar-Powered Refrigeration System

    Science.gov (United States)

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

    2001-01-01

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

  2. Investigation of adsorption performance deterioration in silica gel–water adsorption refrigeration

    International Nuclear Information System (INIS)

    Highlights: ► Adsorption deterioration of silica gel in refrigeration systems is verified. ► Possible factors to cause such deterioration are analyzed. ► Specific surface area, silanol content and adsorption capacity are tested. ► The pollution is the primary factor to decline the adsorption capacity. ► Deteriorated samples are partly restored after being processed by acid solution. - Abstract: Silica gel acts as a key role in adsorption refrigeration systems. The adsorption deterioration must greatly impact the performance of the silica gel–water adsorption refrigeration system. In order to investigate the adsorption deterioration of silica gel, many different silica gel samples were prepared according to the application surroundings of silica gel in adsorption refrigeration systems after the likely factors to cause such deterioration were analyzed. The specific surface area, silanol content, adsorption capacity and pore size distribution of those samples were tested and the corresponding adsorption isotherms were achieved. In terms of the experimental data comparisons, it could be found that there are many factors to affect the adsorption performance of silica gel, but the pollution was the primary one to decline the adsorption capacity. In addition, the adsorption performance of the deteriorated samples after being processed by acid solution was explored in order to find the possible methods to restore its adsorption performance.

  3. Adsorption Refrigeration Performance of Shaped MIL-101-Water Working Pair

    Institute of Scientific and Technical Information of China (English)

    芮征球; 李全国; 崔群; 王海燕; 陈海军; 姚虎卿

    2014-01-01

    A new metal-organic framework of MIL-101 was synthesized by hydrothermal method and the powder prepared was pressed into a desired shape. The effects of molding on specific surface area and pore structure were investigated using a nitrogen adsorption method. The water adsorption isotherms were obtained by high vacuum gravimetric method, the desorption temperature of water on shaped MIL-101 was measured by thermo gravimetric analyzer, and the adsorption refrigeration performance of shaped MIL-101-water working pair was studied on the simulation device of adsorption refrigeration cycle system. The results indicate that an apparent hysteresis loop ap-pears in the nitrogen adsorption/desorption isotherms when the forming pressure is 10 MPa. The equilibrium ad-sorption capacity of water is up to 0.95 kg·kg-1 at the forming pressure of 3 MPa (MIL-101-3). The desorption peak temperature of water on MIL-101-3 is 82 °C, which is 7 °C lower than that of silica gel, and the desorption temperature is no more than 100 °C. At the evaporation temperature of 10 °C, the refrigeration capacity of MIL-101-3-water is 1059 kJ·kg-1, which is 2.24 times higher than that of silica gel-water working pair. Thus MIL-101-water working pair presents an excellent adsorption refrigeration performance.

  4. Experimental analysis of an adsorption refrigerator with mass and heat-pipe heat recovery process

    International Nuclear Information System (INIS)

    Highlights: ► We develop one heat pipe type adsorption refrigerator. ► New compound adsorbent of CaCl2/activated carbon–ammonia can work more effectively. ► Combined mass recovery-heat pipe heat recovery can improve adsorption performance. ► Combined mass recovery-heat pipe heat recovery can reduce cycle time. - Abstract: A heat pipe type adsorption refrigerator system is proposed and investigated, which can be powered by solar energy or waste heat of engine. The study assesses the performance of compound adsorbent (CaCl2 and activated carbon)–ammonia adsorption refrigeration cycle with different orifice sets and different mass and heat recovery processes by experimental prototype machine. Specific cooling power (SCP) and coefficient of performance (COP) were calculated with experimental data to analyze the influences of operating condition. The results show that the jaw opening of the hand needle nozzle can influence the adsorption performance obviously and the thermostatic expansion valve (TEV) is effective in the intermediate cycle time in the adsorption refrigeration system. The SCP of the cycle with the mass-heat recovery together (combined recovery process) is superior to that of the conventional cycles with mass recovery or heat recovery independently.

  5. REVIEW: USE of COMPOSITE ADSORBENTS in ADSORPTION REFRIGERATION

    Directory of Open Access Journals (Sweden)

    Satishchandra V. Joshi

    2012-01-01

    Full Text Available The urbanization across the world has resulted in increased demand for refrigeration and air conditioning. The main disadvantage with the conventional method i.e. vapor compression system is environment pollution. Another problem faced during urbanization is energy crisis. The adsorption refrigeration system is one of the solutions to this problem. The advantages of this system are environment friendly, less noise, use of waste heat or solar energy. But the disadvantage with adsorption system is low coefficient of performance (COP and bulkiness. Researchers across the world are working on this issue to make adsorption system a viable alternative to the compression systems. Since the last two decades considerable work is being done on the use of composite adsorbents to improve the heat and mass transfer performance. This kind of adsorbent is usually obtained by the combination of a chemical adsorbents and physical adsorbents.

  6. A study on multifunction heat pipe type high efficient adsorption refrigerator using compound adsorbent-ammonia

    Institute of Scientific and Technical Information of China (English)

    LU Zisheng; WANG Ruzhu; WANG Liwei; CHEN Chuanjuan

    2006-01-01

    A multifunction heat pipe adsorption refrigerator is designed, which uses solidified compound adsorbent of CaCl2 and activated carbon as adsorbent. Two work conditions, ice-maker driven by the exhaust heat from diesel engine and air-condi- tioning powered by solar energy, are studied. SCP (specific cooling power) and COP (coefficient of per- formance) for different conditions are analyzed. The optimum average SCP and COP for the refrigerator powered by waste heat of diesel engine are 770.4 W/kg and 0.39 at about -20℃ evaporating tem- perature. The optimum average SCP and COP for the refrigerator powered by solar energy are 524.2 W/kg and 0.27 at about 5.6℃ evaporating tempera- ture.

  7. PERFORMANCE STUDY OF A TWO STAGE SOLAR ADSORPTION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    BAIJU. V

    2011-07-01

    Full Text Available The present study deals with the performance of a two stage solar adsorption refrigeration system with activated carbon-methanol pair investigated experimentally. Such a system was fabricated and tested under the conditions of National Institute of Technology Calicut, Kerala, India. The system consists of a parabolic solar concentrator,two water tanks, two adsorbent beds, condenser, expansion device, evaporator and accumulator. In this particular system the second water tank is act as a sensible heat storage device so that the system can be used during night time also. The system has been designed for heating 50 litres of water from 25oC to 90oC as well ascooling 10 litres of water from 30oC to 10oC within one hour. The performance parameters such as specific cooling power (SCP, coefficient of performance, solar COP and exergetic efficiency are studied. The dependency between the exergetic efficiency and cycle COP with the driving heat source temperature is also studied. The optimum heat source temperature for this system is determined as 72.4oC. The results show that the system has better performance during night time as compared to the day time. The system has a mean cycle COP of 0.196 during day time and 0.335 for night time. The mean SCP values during day time and night time are 47.83 and 68.2, respectively. The experimental results also demonstrate that the refrigerator has cooling capacity of 47 to 78 W during day time and 57.6 W to 104.4W during night time.

  8. Keeping Cool With Solar-Powered Refrigeration

    Science.gov (United States)

    2003-01-01

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

  9. PERFORMANCE STUDY OF A TWO STAGE SOLAR ADSORPTION REFRIGERATION SYSTEM

    OpenAIRE

    BAIJU. V; Muraleedharan, C.

    2011-01-01

    The present study deals with the performance of a two stage solar adsorption refrigeration system with activated carbon-methanol pair investigated experimentally. Such a system was fabricated and tested under the conditions of National Institute of Technology Calicut, Kerala, India. The system consists of a parabolic solar concentrator,two water tanks, two adsorbent beds, condenser, expansion device, evaporator and accumulator. In this particular system the second water tank is act as a sensi...

  10. The Applie d Research of Dual-effect Solid-adsorption Type Refrigeration Technology for Use in a Centralized Refrigeration System at a Thermal Power Plant%双效固体吸附制冷技术在热电厂集中 供冷中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李中华; 王如竹

    2001-01-01

    采用双效固体吸附式制冷技术开发了热电厂新型集中供冷系 统。该系统结构简单、性能可靠、投资低、耗电少、无污染。不但可为全厂提供空调用冷, 而且可大幅度提高电厂机组热经济性,具有显著的节能与环保效果。%An innovative centralized refrigeration system was developed for a thermal power plant through the use of a dual-effect solid-adsorption type refrigeration te ch nology. The system features a simple structural design, reliable performance, lo w investment outlay, low power consumption and absence of pollutants. With the h elp of this system it is not only possible to supply cooling energy for the air - conditioning of the thermal power plant as a whole, but also greatly enhance the thermal efficiency of the power plant. Moreover, it also contributes to signifi cant energy savings and a pollution-free environment.

  11. Adsorption performances and refrigeration application of adsorption working pair of CaCl2-NH3

    Institute of Scientific and Technical Information of China (English)

    WANG; Liwei; WANG; Ruzhu; WU; Jingyi; WANG; Kai

    2004-01-01

    The adsorption performance of CaCl2-NH3 is studied under the condition of different expansion spaces for adsorbent, andthe relationships between adsorption performance of CaCl2-NH3 and the phenomena of swelling and agglomeration during adsorption are researched. It is found that the performance stability is related to the ratio of expansion space to the volume of adsorbent ras, and the performance attenuation is serious in the case of large ras. Severe adsorption hysteresis exists in the process of adsorption and desorption at the same evaporating and condensing temperatures, which is related to the stability constant of chemical reaction. This phenomenon cannot be explained by the theory of physical adsorption. Moderate agglomeration will be beneficial to the formation of ammoniate complex; the magnitude of expansion space will affect adsorption performance. Analysis shows that the activated energy needed in the process of adsorption for the sample with ras of 2:1 is less than that for the sample with ras of 3:1.The refrigeration performance of CaCl2-NH3 is predicted from experiments. The cooling capacity of one adsorption cycle is about 945.4 kJ/kg for the adsorbent with an ras of 2:1 at the evaporating temperature of 0℃.

  12. Simulation study of a combined adsorption refrigeration system

    International Nuclear Information System (INIS)

    In this study, we have divided combined ADRS into four types based on different arrangements of two working pairs, Zeolite 13x/CaCl2-water and Silica gel (RD type)–water, to analyze the performance of combined ADRS. After validating mathematical models with available experimental data, ADRS is simulated by using Simulink–Matlab software to achieve optimum times for various processes. The results of simulation show that the cooling capacity of the system with Zeolite 13x/CaCl2-water is more than the other types. The results have shown that the arrangement of adsorbents affects cooling capacity of combined ADRS significantly. In Type A, Zeolite 13x/CaCl2-water has been used as an adsorbent for both top and bottom cycles. This type not only has more cooling capacity than the other types, but also the effect of hot water temperature on cooling capacity of this type is less than the others. Furthermore, a sensitivity analysis has been done to determine the importance of each parameter on ADRS system because the cooling capacity and the COP are influenced by many constant parameters. - Highlights: • Development of a thermodynamic model for a combined adsorption refrigeration system. • Zeolite 13X/CaCl2 is considered as a new adsorbent in a combined adsorption refrigeration system. • Zeolite 13X/CaCl2-water are more advantageous than the other working pairs

  13. Experimental study of a novel CaCl{sub 2}/expanded graphite-NH{sub 3} adsorption refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.L.; Xia, Z.Z.; Wu, J.Y.; Li, J.; Wang, R.Z.; Wang, L.W. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200030 (China)

    2010-01-15

    A novel CaCl{sub 2}/expanded graphite-NH{sub 3} adsorption refrigerator is developed and tested. Only three valves are installed in this refrigerator and they all work at the same positive pressure condition, so the operating reliability of the refrigerator is greatly improved. The experimental results show that the refrigerating power Q{sub CP}, COP, SCP, electricity COP{sub El}, and volume refrigerating density Q{sub CP-V} of the refrigerator are 11.4 kW, 0.27, 422.2 W/kg, 32.6 and 57 kW/m{sup 3}, respectively, under the following conditions: the temperature of heating vapor is from 120 C to 140.3 C, the cooling water temperature is 25 C, the evaporation temperature is -15 C, the heating/cooling time is 25 min including 45 s mass recovery time. The SCP and volume refrigerating density of this refrigerator are about 1.8 times and 1.5 times that of the maximum of the former test results by other researchers. (author)

  14. Performance Evaluation of a Solar Adsorption Refrigeration System with a Wing Type Compound Parabolic Concentrator

    OpenAIRE

    Muhammad Umair; Atsushi Akisawa; Yuki Ueda

    2014-01-01

    Simulation study of a solar adsorption refrigeration system using a wing type compound parabolic concentrator (CPC) is presented. The system consists of the wing type collector set at optimum angles, adsorption bed, a condenser and a refrigerator. The wing type collector captures the solar energy efficiently in the morning and afternoon and provides the effective temperature for a longer period of time compared to that achieved by a linear collector. The objectives of the study were to evalua...

  15. Design improvements for a collector/generator/adsorber of a solid adsorption solar refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Ogueke, N.V.; Anyanwu, E.E. [Mechanical Engineering Department, Federal University of Technology, P.M.B. 1526, Owerri (Nigeria)

    2008-11-15

    A study of the effects of different collector design parameters on the performances of a solar powered solid adsorption refrigerator is presented. The refrigerator uses activated carbon/methanol as the adsorbent/refrigerant pair. The study was undertaken using a computer simulation program developed from a transient analysis of the system. The parameters tested are the collector plate emissivity/absorptivity combination, adsorbent packing density, tube spacing, outer tube outside diameter, adsorbent thermal conductivity, heat transfer coefficient at adsorbent/tube interface, and adsorbent tube/collector plate materials combination. Two performance indicators namely, condensate yield and coefficient of performance (COP) were used in the study as figures of merit. A multiple regression technique was used to correlate the performance indicators with the collector parameters through a quadratic relation. Consequently an objective function, suitable for selecting optimal values of the parameters is defined, subject to specified constraints. Selecting the COP as the preferred indicator parameter, optimization was then carried out. Improvements in the ranges of 29-38% for COP and 26-35% for condensate yield were obtained with optimal choices of tube spacing, adsorbent packing density and collector plate/adsorbent tube material combinations. (author)

  16. Optimization of solar adsorption refrigeration system using experimental and statistical techniques

    International Nuclear Information System (INIS)

    This paper presents the design of new prototype of a solar adsorption refrigeration unit with certain specifications and requirements to be used as an air conditioning and refrigeration unit suitable to be used in remote areas. The new device uses activated carbon (used as adsorbents) with methanol (as adsorbate) forming an adsorbent-adsorbate pairs. Experimental data with statistical technique are used in this paper to get the optimum design parameters of the solar adsorption refrigeration system with an acceptable result of COP (coefficient of performance) and cooling production. The minimum temperature obtained for the refrigerator was 9 deg. C while the ambient temperature was 26 deg. C. The effective refrigeration started at 21:10 and the temperature decreased gradually until it reached 9 deg. C at 01:30 next day then it increased above the minimum temperature. The gross cycle coefficient of performance, COPa = 0.688 from the thermodynamic calculations.

  17. Research on the chemical adsorption precursor state of CaCl2-NH3 for adsorption refrigeration

    Institute of Scientific and Technical Information of China (English)

    WANG; Liwei; WANG; Ruzhu; WU; Jingyi; WANG; Kai

    2005-01-01

    As a type of chemical adsorption working pair, the physical adsorption occurs first for CaCl2-NH3 because the effective reaction distance for van der Waals force is longer than that for chemical reaction force, and this physical adsorption state is named the precursor state of chemical adsorption. In order to get the different precursor states of CaCl2-NH3, the different distances between NH3 gas and Ca2+ are realized by the control of different phenomena of swelling and agglomeration in the process of adsorption. When the serious swelling exists while the agglomeration does not exist in the process of adsorption, experimental results show that the activated energy consumed by adsorption reaction increases for the reason of longer distance between Ca2+ and NH3, and at the same time the performance attenuation occurs in the repeated adsorption cycles. When the agglomeration occurs in the process of adsorption, the activated energy for the transition from precursor state to chemical adsorption decreases because the distance between NH3 gas and Ca2+ is shortened by the limited expansion space of adsorbent, and at the same time the performance attenuation does not occur. The adsorption refrigeration isobars are researched by the precursor state of chemical adsorption; results also show that the precursor state is a key factor for isobaric adsorption performance while the distribution of Ca2+ does not influence the permeation of NH3 gas in adsorbent.

  18. Modelling of a chemisorption refrigeration and power cogeneration system

    International Nuclear Information System (INIS)

    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. Review of solid adsorption solar refrigeration II: An overview of the principles and theory

    International Nuclear Information System (INIS)

    A review of the basic principles and theories of solid adsorption solar refrigeration is presented. The cycle performance thermodynamics is also reviewed, and the criteria for selection of adsorbent/adsorbent pairs are reported. The practically realised solar adsorption cooling systems were categorized by their adsorbate operating pressure ranges as low and high pressure systems, and their pertinent design features are given. Adsorption equilibrium models that account for the adsorption properties of a pair of adsorbent/adsorbate and act as state equations in analytical models of the machine are reported

  20. Acoustic recovery of lost power in pulse tube refrigerators

    International Nuclear Information System (INIS)

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

  1. 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...

  2. Heat transfer design in adsorption refrigeration systems for efficient use of low-grade thermal energy

    International Nuclear Information System (INIS)

    Adsorption refrigeration and heat pump systems have been considered as important means for the efficient use of low-grade thermal energy of 60-150 oC. Sorption systems are merely thermodynamic systems based on heat exchangers, and therefore a good design to optimize heat and mass transfer with reaction or sorption processes is very important, for which the notable technique is the use of expanded graphite to improve both heat and mass transfer in the chemisorption beds. Studies have also shown the need to enhance the heat transfer in adsorption bed by matching with the efficient heat transfer of thermal fluids. Heat pipes and good thermal loop design coupled with adsorption beds could yield higher thermal performance of a sorption system. A novel design with passive evaporation, known as rising film evaporation coupled with a gravity heat pipe was introduced for high cooling output. It has also been shown that the performance of traditional heat and mass recovery in the sorption systems is limited, and novel arrangement of thermal fluid and refrigerant may improve the performance of sorption systems. Based upon the above researches, various sorption systems have been developed, and high performances have been reached. -- Highlights: →Heat transfer design in adsorption refrigeration systems is researched. →Solidified adsorbent is an effective way to improve the heat transfer. →Heat pipe and rising film evaporation could generate high cooling output. With efficient design two adsorption systems are developed. →Double way and double effect cycle is introduced.

  3. Review paper on solar-powered air-conditioning through adsorption route

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, B.; Chatterjee, P.K. [Thermal Engineering Group, Central Mechanical Engineering Research Institute, Durgapur 713209 (India); Sarkar, J.P. [Chemical Engineering Department, National Institute of Technology, Durgapur 713209 (India)

    2010-10-15

    Solar-power based sorption refrigeration systems do not suffer from the problem of greenhouse gas emission and release of ozone layer depleting substances as in the case of conventional vapour compression refrigeration system. Absorption based systems are already commercially available while adsorption based systems are still in research and development stage. Progress and development of solar-powered adsorption cooling systems have been described in this paper. Factors preventing commercialization of this system have been discussed in detail. The state of the ongoing research, to make the system more efficient and cost effective, has been presented. (author)

  4. Neon turbo-Brayton cycle refrigerator for HTS power machines

    Science.gov (United States)

    Hirai, Hirokazu; Hirokawa, M.; Yoshida, Shigeru; Nara, N.; Ozaki, S.; Hayashi, H.; Okamoto, H.; Shiohara, Y.

    2012-06-01

    We developed a prototype turbo-Brayton refrigerator whose working fluid is neon gas. The refrigerator is designed for a HTS (High Temperature Superconducting) power transformer and its cooling power is more than 2 kW at 65 K. The refrigerator has a turboexpander and a turbo-compressor, which utilize magnetic bearings. These rotational machines have no rubbing parts and no oil-components. Those make a long maintenance interval of the refrigerator. The refrigerator is very compact because our newly developed turbo-compressor is volumetrically smaller than a displacement type compressor in same operating specification. Another feature of the refrigerator is a wide range operation capability for various heat-loads. Cooling power is controlled by the input-power of the turbo-compressor instead of the conventional method of using an electric heater. The rotational speed of the compressor motor is adjusted by an inverter. This system is expected to be more efficient. We show design details, specification and cooling test results of the new refrigerator in this paper.

  5. Experimental Investigation on Adsorption Capacity of a Variety of Activated Carbon/Refrigerant Pairs

    Directory of Open Access Journals (Sweden)

    Ahmed N. Shmroukh

    2015-04-01

    Full Text Available This study aims to develop a device with minimum heat and mass transfer limitations between adsorbent and adsorbate, and subsequently to obtain practically applicable adsorption capacity data. Also, 5 kW adsorption chillers (evaporators, condensers and adsorbers are designed based on the experimental output data of the whole tested pairs. A finned-tube heat exchanger was employed and installed at the center adsorber, and each employed adsorbent was immobilized on its surfaces by using an adhesive agent. A variety of pairs: are activated carbon powder (ACP/R-134a, ACP/R-407c, ACP/R-507A, activated carbon granules (ACG/R-507A, ACG /R-407c and ACG /R-134a, were examined at different adsorption temperatures of 25, 30, 35 and 50°C. It was found that, at the adsorption temperature of 25°C the maximum adsorption capacity was 0.8352 kg kg-1 for ACP/R-134a, while at the adsorption temperature of 50°C the maximum adsorption capacity was 0.3207 kg kg-1 for ACP/R- 134a. Therefore, the ACP/R-134a pair is highly recommended to be employed as adsorption refrigeration working pair because of its higher maximum adsorption capacity higher than the other examined pairs.

  6. Adsorption refrigeration-An efficient way to make good use of waste heat and solar energy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, R.Z.; Oliveira, R.G. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Huashan Rd., Shanghai 200030 (China)

    2006-07-01

    This paper presents the achievements gained in solid sorption refrigeration prototypes since the end of the l970s, when interest in sorption systems was renewed. The applications included are ice making and air conditioning. The latter includes not only cooling and heating, but also dehumidification by desiccant systems. The prototypes presented were designed to use waste heat or solar energy as the main heat source. The waste heat could be from diesel engines or from power plants, in combined cooling, heating and power systems (CCHP). The current technology of adsorption solar-powered icemakers allows a daily ice production of between 4 and 7kgm{sup -2} of solar collector, with a solar coefficient of performance (COP) between 0.10 and 0.16. The silica gel-water chillers studied can be powered by hot water warmer than 55{sup o}C. The COP is usually around 0.2-0.6, and in some commercially produced machines, it can be up to 0.7. The utilization of such chillers in CCHP systems, hospitals, buildings and grain depots are discussed. Despite their advantages, solid sorption systems still present some drawbacks such as low specific cooling power (SCP) and COP. Thus, some techniques to overcome these problems are also contemplated, together with the perspectives for their broad commercialisation. Among these techniques, a special attention was devoted to innovative adsorbent materials, to advanced cycles and to heat pipes, which are suitable devices not only to improve the heat transfer but also can help to avoid corrosion in the adsorbers. Recent experiments performed by the research group of the authors with machines that employ composite adsorbent material and heat pipes showed that it is possible to achieve a SCP of 770Wkg{sup -1} of salt and COP of 0.39 at evaporation temperatures of -20{sup o}C and generation temperature of 115{sup o}C. (author)

  7. Performance investigation of a waste heat driven pressurized adsorption refrigeration cycle

    Science.gov (United States)

    Habib, K.

    2015-12-01

    This article presents performance investigation of a waste heat driven two bed pressurised adsorption refrigeration system. In this study, highly porous activated carbon (AC) of type Maxsorb III has been selected as adsorbent while n-butane, R-134a, R410a, R507a and carbon dioxide (CO2) are chosen as refrigerants. All the five refrigerants work at above atmospheric pressure. Among the five pairs studied, the best pairs will be identified which will be used to provide sufficient cooling capacity for a driving heat source temperature above 60°C. Results indicate that for a driving source temperature above 60°C, AC-R410a pair provides highest cooling capacity while AC-CO2 pairs works better when the heat source temperature falls below 60°C.

  8. Experimental Study On Thermal Wave Type Adsorption Refrigeration System Working On A Pair Of Activated Carbon And Methanol

    OpenAIRE

    Grzebielec Andrzej; Rusowicz Artur; Laskowski Rafał

    2015-01-01

    The aim of the study was to examine the efficiency of the thermal wave type adsorption refrigerating equipment working on a pair of activated carbon and methanol. Adsorption units can work in trigeneration systems and in applications driven by waste heat. They can be built also as a part of hybrid sorption-compressor systems, and they are very popular in solar refrigeration systems and energy storage units. The device examined in this study operates in a special mode called thermal wave. This...

  9. Transient analysis and performance prediction of a solid adsorption solar refrigerator

    International Nuclear Information System (INIS)

    The transient analysis and performance prediction of a solid adsorption solar refrigerator, using activated carbon/methanol adsorbent/adsorbate pair are presented. The mathematical model is based on the thermodynamics of the adsorption process, heat transfer in the collector plate/tube arrangement, and heat and mass transfers within the adsorbent/adsorbate pair. Its numerical model developed from finite element transformation of the resulting equations computes the collector plate and tube temperatures to within 5 deg. C. The condensate yield and coefficient of performance, COP, were predicted to within 5% and 9%, respectively. The resulting evaporator water temperature was also predicted to within 5 deg. C. Thus the model is considered a useful design tool for the refrigerator to avoid costly experimentation

  10. An innovative ecological hybrid refrigeration cycle for high power refrigeration facility

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2015-09-01

    Full Text Available Searching for new refrigerants is one of the most significant scientific problems in refrigeration. There are ecological refrigerants commonly known: H2O and CO2. H2O and CO2 known as natural refrigerants, but they have problems:a high freezing point of H2O and a low triple point of CO2. These problems can be solved by the application of a hybrid sorption-compression refrigeration cycle. The cycle combines the application possibility of H2O in the high temperature sorption stage and the low temperature application of CO2 in the compression stage. This solution gives significant energy savings in comparison with the two-stage compressor cycle and with the one-stage transcritical CO2 cycle. Besides, the sorption cycle may be powered by low temperature waste heat or renewable heat. This is an original idea of the authors. In the paper an analysis of the possible extension of this solution for high capacity industrial refrigeration is presented. The estimated energy savings as well as TEWI (Total Equivalent Warming Impact index for ecological gains are calculated.

  11. Exergy Assessment of Single Stage Solar Adsorption Refrigeration System Using ANN

    OpenAIRE

    Baiju, V.; C. Muraleedharan

    2012-01-01

    A new approach based on artificial intelligence is proposed here for the exergy assessment of solar adsorption refrigeration system working with activated carbon-methanol pair. Artificial neural network model is used for the prediction of exergy destruction and exergy efficiency of each component of the system. Pressure, temperature and solar insolation are used as input variables for developing the artificial neural network model. The back propagation algorithm with three different variants ...

  12. PREDICTION OF SOLAR ADSORPTION REFRIGERATION SYSTEM PERFORMANCE USING ANN BASED ON GENETIC LEARNING

    OpenAIRE

    Salah. Hanini; Maamar Laidi

    2012-01-01

    An adsorptive solar refrigerator performance was modelled using artificial neural networks (ANNs). This model takes into account the adsorbent bed, condenser and the evaporator characteristics as well as the working pair (Activated carbon /methanol) properties and the climate conditions. The supervised learning of the ANN is based on a genetic algorithm (GA) supported by an elitist strategy. Input, hidden and output layers model the topology of the ANN. The weights of the synapses and the bia...

  13. Experimental study on activated carbon-nitrogen pair in a prototype pressure swing adsorption refrigeration system

    Science.gov (United States)

    Anupam, Kumar; Palodkar, Avinash V.; Halder, G. N.

    2016-04-01

    Pressure swing adsorption of nitrogen onto granular activated carbon in the single-bed adsorber-desorber chamber has been studied at six different pressures 6-18 kgf/cm2 to evaluate their performance as an alternative refrigeration technique. Refrigerating effect showed a linear rise with an increase in the operating pressure. However, the heat of adsorption and COP exhibited initial rise with the increasing operating pressure but decreased later after reaching a maximum value. The COP initially increases with operating pressures however, with the further rise of operating pressure it steadily decreased. The highest average refrigeration, maximum heat of adsorption and optimum coefficient of performance was evaluated to be 415.38 W at 18 kgf/cm2, 92756.35 J at 15 kgf/cm2 and 1.32 at 12 kgf/cm2, respectively. The system successfully produced chilled water at 1.7 °C from ambient water at 28.2 °C.

  14. Thermal conductivities study of new types of compound adsorbents used in solar adsorption refrigeration

    International Nuclear Information System (INIS)

    In this paper, the thermal probe is firstly introduced and used in adsorption refrigeration to measure the working pair's thermal conductivities. Different types of compound adsorbents were prepared, and the thermal conductivities of all the types were measured with different adsorption capacities. Experimental results demonstrate that: with the same adsorption capacity, the conductivities of the compound adsorbents increase with the quantity of sodium silicate (Na2SiO3) content. The conductivities of the compound adsorbents increase sharply when the sodium silicate content is between 0% and 7.5% and increase slowly when the content is 7.5-20%. For 13x zeolite and compound adsorbents Z3 and Z4, their thermal conductivities increase as a quadratic polynomial with their adsorption capacities. The conductivities increase more than 158.2% when the adsorption capacities increase from 0% to 25%. The thermal conductivities of compound adsorbent Z3 and Z4 are 0.183 and 0.199 W (m K)-1, respectively, and increase about 65.4% and 80.1%, respectively, compared with the 13x zeolite. With these test results, the compound adsorbent Z4 is used for making an adsorption bed, and the experimental coefficient of performance (COP) of the solar cooling tube is about 0.26.

  15. Dry Dilution Refrigerator with High Cooling Power

    Science.gov (United States)

    Uhlig, K.

    2008-03-01

    We present the construction concept and cooling capacity measurements of a 3,4He dilution refrigerator (DR), which was pre-cooled by a commercial pulse tube refrigerator (PTR). No cryogens are needed for the operation of this type of cryostat. The condensation of the helium mash was done in an integrated Joule-Thomson circuit, which was part of the dilution unit. The composition of the dilution unit was standard, but its components (still, heat exchangers, mixing chamber) were designed for high 3He flow. For thermometry, calibrated RuO chip resistance thermometers were available. In order to condense the mixture before an experiment, the fridge was operated like a Joule-Thomson liquefier with a relatively high inlet pressure (4 bar), where the liquid fraction of the circulating 3,4He mixture was accumulated in the dilution unit. The condensation took about 2 hours, and after 2 more hours of running, the temperature of the mixing chamber approached its minimum temperature of 10 mK. The maximum flow rate of the fridge was 1 mmol/s, and the refrigeration capacity of the mixing chamber was 700 μW at 100 mK. High cooling capacity, ease of operation and reliability distinguish this type of milli-Kelvin cooler.

  16. Performance study of unglazed cylindrical solar collector for adsorption refrigeration system

    Science.gov (United States)

    Mahesh, A.; Kaushik, S. C.; Kumaraguru, A. K.

    2013-12-01

    In the present communication, the unglazed cylindrical solar adsorber module is suggested for refrigeration and theoretical models for the heat and mass transfer in the cylindrical adsorber with heat balance equations in the collector components have been developed. It has been found that, both the SCP and COPsolar raises with increasing the evaporation temperature and drop off with the increase of the condensation temperature. The COPsolar increased from 0.15 to 0.52 with the increase of the total solar energy absorbed by the collector while the COPcycle varied in the range of 0.57-0.73. The efficiency of unglazed solar collector varied from 36 to 44 %. The cost of current unglazed adsorption refrigeration system is compared with the glazed system, and it is 33 to 50 % less than the cost of glazed system.

  17. SOLAR REFRIGERATING UNIT WITH AN ADSORPTION REACTOR AND EVACUATED TUBE COLLECTORS

    Directory of Open Access Journals (Sweden)

    M.E. Vieira

    1997-09-01

    Full Text Available This work presents the principles of operation of a solar refrigerator with the following basic components: a reactor, a set of evacuated tube solar collectors, a condenser, a heat exchanger, and an evaporator. During the heating phase, solar radiation is collected and transferred to the reactor for desorption by a vapor thermal siphon loop. During the cooling phase, heat from the reactor is released to the ambient by a second water vapor loop. Ambient data collected daily during a period of 18 years were divided into hourly values and used to simulate the temperatures of the reactor, which uses salt impregnated with graphite and ammonia, during the adsorption / desorption processes. The results show that the refrigerator operates well in Fortaleza and that better results are expected for the countryside of the state of Ceara. It is concluded that only a high efficiency collector set can be used in the system

  18. Carbon-ammonia pairs for adsorption refrigeration applications: ice making, air conditioning and heat pumping

    Energy Technology Data Exchange (ETDEWEB)

    Tamainot-Telto, Z.; Metcalf, S.J.; Critoph, R.E.; Zhong, Y.; Thorpe, R. [School of Engineering, University of Warwick, Gibbet Hall Road, Coventry CV4 7AL (United Kingdom)

    2009-09-15

    A thermodynamic cycle model is used to select an optimum adsorbent-refrigerant pair in respect of a chosen figure of merit that could be the cooling production (MJ m{sup -3}), the heating production (MJ m{sup -3}) or the coefficient of performance (COP). This model is based mainly on the adsorption equilibrium equations of the adsorbent-refrigerant pair and heat flows. The simulation results of 26 various activated carbon-ammonia pairs for three cycles (single bed, two-bed and infinite number of beds) are presented at typical conditions for ice making, air conditioning and heat pumping applications. The driving temperature varies from 80 C to 200 C. The carbon absorbents investigated are mainly coconut shell and coal based types in multiple forms: monolithic, granular, compacted granular, fibre, compacted fibre, cloth, compacted cloth and powder. Considering a two-bed cycle, the best thermal performances based on power density are obtained with the monolithic carbon KOH-AC, with a driving temperature of 100 C; the cooling production is about 66 MJ m{sup -3} (COP = 0.45) and 151 MJ m{sup -3} (COP = 0.61) for ice making and air conditioning respectively; the heating production is about 236 MJ m{sup -3} (COP = 1.50). (author) [French] Un modele du cycle thermodynamique est utilise pour selectionner le meilleur couple adsorbant-ammoniac sur la base de la production frigorifique (MJ m{sup -3}), la production de chaleur (MJ m{sup -3}) ou bien le coefficient de performance (COP). Ce modele est essentiellement base sur les equations d'etat de l'adsorption (adsorbant-ammoniac). Les resultats de simulation de 26 differents couples charbon actif-ammoniac sont presentes pour des conditions typiques de fabrication de la glace, de climatisation et de pompe a chaleur. La temperature de generation varie de 80 C a 200 C. Les simulations sont effectuees pour trois types de cycle: lit unique, deux-lits et un nombre infini de lits. Les charbons actifs etudies sont

  19. Heat Transfer Analysis of a Flat-plate Solar Collector Running a Solid Adsorption Refrigerator

    Directory of Open Access Journals (Sweden)

    S. Thiao

    2014-05-01

    Full Text Available Adsorption solar cooling appears to have prospect in the tropical countries. The present study is a theoretical investigation of the performance of a solar adsorption refrigerator using a flat-plate solar collector. The values of glass cover and absorber plate temperatures obtained from numerical solutions of heat balance equations are used to predict the solar coefficient of performance of the solar refrigerator. The simulation technique takes into account the variations of ambient temperature and solar radiation along the day. The effects of optical parameters of the glass cover such as absorption and transmission coefficients on glass cover and absorber plate temperatures and consequently on the coefficient of performance are analyzed. As a result, it is found that the absorber plate temperature is less to the absorption coefficient than the cover glass temperature. Also the thermal radiation exchange has more effect on the cover glass temperature. The higher values of COP are obtained between 11 and 13 h during the morning when the temperatures of the absorber plate and the ambient temperatures increase. Moreover the COP increases with the coefficient of transmission of the glass cover but the main parameter acting on the variations of the COP remains the temperature of the evaporator.

  20. Performance Evaluation of a Solar Adsorption Refrigeration System with a Wing Type Compound Parabolic Concentrator

    Directory of Open Access Journals (Sweden)

    Muhammad Umair

    2014-03-01

    Full Text Available Simulation study of a solar adsorption refrigeration system using a wing type compound parabolic concentrator (CPC is presented. The system consists of the wing type collector set at optimum angles, adsorption bed, a condenser and a refrigerator. The wing type collector captures the solar energy efficiently in the morning and afternoon and provides the effective temperature for a longer period of time compared to that achieved by a linear collector. The objectives of the study were to evaluate the system behavior, the effect of wing length, and to compare the performance of the systems with wing type and linear CPCs. A detailed dynamic simulation model was developed based on mass and energy balance equations. The simulation results show that the system performance with wing type CPC increases by up to 6% in the summer and up to 2% in the winter, compared to the performance with a linear CPC having same collector length. The ice production also increases up to 13% in the summer with the wing type CPC. This shows that the wing type CPC is helpful to increase the performance of the system compared to the linear CPC with the same collector length and without the need for tracking.

  1. Performance studies on mechanical + adsorption hybrid compression refrigeration cycles with HFC 134a

    Energy Technology Data Exchange (ETDEWEB)

    Banker, N.D.; Dutta, P.; Srinivasan, K. [Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560 012 (India); Prasad, M. [Thermal Systems Division, ISRO Satellite Centre, Bangalore 560 017 (India)

    2008-12-15

    This paper presents the results of an investigation on the efficacy of hybrid compression process for refrigerant HFC 134a in cooling applications. The conventional mechanical compression is supplemented by thermal compression using a string of adsorption compressors. Activated carbon is the adsorbent for the thermal compression segment. The alternatives of bottoming either mechanical or thermal compression stages are investigated. It is shown that almost 40% energy saving is realizable by carrying out a part of the compression in a thermal compressor compared to the case when the entire compression is carried out in a single-stage mechanical compressor. The hybrid compression is feasible even when low grade heat is available. Some performance indictors are defined and evaluated for various configurations. (author)

  2. PREDICTION OF SOLAR ADSORPTION REFRIGERATION SYSTEM PERFORMANCE USING ANN BASED ON GENETIC LEARNING

    Directory of Open Access Journals (Sweden)

    Salah. Hanini

    2012-08-01

    Full Text Available An adsorptive solar refrigerator performance was modelled using artificial neural networks (ANNs. This model takes into account the adsorbent bed, condenser and the evaporator characteristics as well as the working pair (Activated carbon /methanol properties and the climate conditions. The supervised learning of the ANN is based on a genetic algorithm (GA supported by an elitist strategy. Input, hidden and output layers model the topology of the ANN. The weights of the synapses and the biases for hidden and output nodes are used as design variables in the ANN learning process. The mean relative error between experimental (extracted from literature and simulated results are used to monitor the learning process. The optimal ANN obtained after learning is tested. This approach of ANN learning based on GA presents low mean relative errors in learning and testingphases.

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

    International Nuclear Information System (INIS)

    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)

  4. Solar refrigeration: evaluation of technical options and design of a solar-generator-adsorber for a novel adsorption refrigerator

    OpenAIRE

    Tabassum, Salim Abid

    1989-01-01

    Various technical options for developing a solar operated refrigerator have been discussed. Their suitability for being used as a vaccine store for the conditions specified by the World Health (EPI) Organization Expanded Programme on Immunization 4have been evaluated. A model to predict the performance of a photovoltaic refrigerator have been developed and used to identify factors which influence its performance. It was concluded that it can be more competitive in a...

  5. 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.

  6. An innovative ecological hybrid refrigeration cycle for high power refrigeration facility

    OpenAIRE

    Cyklis Piotr; Janisz Karina

    2015-01-01

    Searching for new refrigerants is one of the most significant scientific problems in refrigeration. There are ecological refrigerants commonly known: H2O and CO2. H2O and CO2 known as natural refrigerants, but they have problems:a high freezing point of H2O and a low triple point of CO2. These problems can be solved by the application of a hybrid sorption-compression refrigeration cycle. The cycle combines the application possibility of H2O in the high temperature sorption stage and the low t...

  7. Analysis of engineering cycles power, refrigerating and gas liquefaction plant

    CERN Document Server

    Haywood, R W

    1991-01-01

    Extensively revised, updated and expanded, the fourth edition of this popular text provides a rigorous analytical treatment of modern energy conversion plant. Notable for both its theoretical and practical treatment of conventional and nuclear power plant, and its studies of refrigerating and gas-liquefaction plant. This fourth edition now includes material on topics of increasing concern in the fields of energy 'saving' and reduction of environmental pollution. This increased coverage deals specifically with the following areas: CHP (cogeneration) plant, studies of both gas and coal burning p

  8. Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair

    OpenAIRE

    Marlinda, Marlinda; Uyun, Aep Saepul; Miyazaki, Takahiko; Ueda, Yuki; Akisawa, Atsushi

    2010-01-01

    A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP) as compared to that of the conventional single-stage cycle for driving temperatures between 100 °C and 150 °...

  9. Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair

    OpenAIRE

    Atsushi Akisawa; Takahiko Miyazaki; Yuki Ueda; Marlinda; Aep Saepul Uyun

    2010-01-01

    A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP) as compared to that of the conventional single-stage cycle for driving temperatures between 100 °C and 150 ...

  10. THERMODYNAMIC ANALYSIS AND SIMULATION OF A NEW COMBINED POWER AND REFRIGERATION CYCLE USING ARTIFICIAL NEURAL NETWORK

    OpenAIRE

    Hossein Rezvantalab; Seyyed Abdolreza Fazeli; Farshad Kowsary

    2011-01-01

    In this study, a new combined power and refrigeration cycle is proposed, which combines the Rankine and absorption refrigeration cycles. Using a binary ammonia-water mixture as the working fluid, this combined cycle produces both power and refrigeration output simultaneously by employing only one external heat source. In order to achieve the highest possible exergy efficiency, a secondary turbine is inserted to expand the hot weak solution leaving the boiler. Moreover, an artificial neural ne...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-06-20

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

  12. Experimental Investigation of a Three-Bed Adsorption Refrigeration Chiller Employing an Advanced Mass Recovery Cycle

    OpenAIRE

    Atsushi Akisawa; Yuki Ueda; Aep Saepul Uyun; Takahiko Miyazaki

    2009-01-01

    The performance of an advanced three-bed adsorption chiller with a mass recovery cycle has been experimentally investigated in the present study. The temperature and pressure of various components of the chiller were monitored to observe the dynamic behaviour of the chiller. The performances in terms of the coefficient of performance (COP) and specific cooling power (SCP) were compared with a conventional single stage. The results show that the proposed cycle produces COP and SCP values super...

  13. Combined Refrigeration Cycle for Thermal Power Plant Using Low Grade Waste Steam

    Directory of Open Access Journals (Sweden)

    Satish Maurya*,

    2014-02-01

    Full Text Available Now a days, In most of the thermal power plant, where low-pressure steam is being exhausted to the atmosphere as a waste steam. This waste heat could be use to operate many small preheating or cooling equipments or small scale plants. There are many refrigeration systems present for refrigeration and air condition purpose. Such as air refrigeration, vapour compression, vapour absorption etc. In this paper we have presented the concept of combined vapour absorption and vapour compression refrigeration system. We present about the idea discuss here that how a vapour absorption and vapour compression can be used together as one complete working refrigeration plant. By using such concept of refrigeration we can improve the co-efficient of performance of whole plant by minimizing the input. We can also named the system as waste heat recovery refrigeration system.

  14. Application genetic algorithms for load management in refrigerated warehouses with wind power penetration

    DEFF Research Database (Denmark)

    Zong, Yi; Cronin, Tom; Gehrke, Oliver;

    2009-01-01

    Wind energy is produced at random times, whereas the energy consumption pattern shows distinct demand peaks during day-time and low levels during the night. The use of a refrigerated warehouse as a giant battery for wind energy is a new possibility that is being studied for wind energy integration...... as well as a way to store electricity produced during night-time by wind turbines. The controller for load management in a refrigerated warehouse with wind power penetration by GA-based is introduced in this paper. The objective function is to minimize the energy consumption for operating the...... refrigerated warehouse. It can be seen that the GA-based control strategy achieves feasible results for operating the temperature in refrigerated warehouse. Balancing the wind power production with refrigerated warehouse load management promises to be a clean and cost effective method. For refrigerated...

  15. Competition between Radiative Power and Dissipation Power in the Refrigeration Process in Oxide Multifilms

    International Nuclear Information System (INIS)

    The maximum refrigeration power dependence on the doping density in the p-BaTiO3/BaTiO3/SrTiO3/BaTiO3/n-BaTiO3 system and in the p-AlGaAs/AlGaAs/GaAs/AlGaAs/n-AlGaAs system is obtained respectively based on the opto-thermionic refrigeration model. The results show that the maximum refrigeration power in the p-BaTiO3/BaTiO3/SrTiO3/BaTiO3/n-BaTiO3 system increases dramatically with the increase of doping density from 1.0 × 1018 cm−3 to 5.0 × 1019 cm−3 while that in the p-AlGaAs/AlGaAs/GaAs/AlGaAs/n-AlGaAs system is nearly a constant. It is found that the different Auger coefficients and the competition between radiative power and dissipation power lead to the different behavior of the maximum refrigeration power dependence on the doping density of the two systems. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  16. Combined Refrigeration Cycle for Thermal Power Plant Using Low Grade Waste Steam

    OpenAIRE

    Satish Maurya*,; Dharmendra Patel

    2014-01-01

    Now a days, In most of the thermal power plant, where low-pressure steam is being exhausted to the atmosphere as a waste steam. This waste heat could be use to operate many small preheating or cooling equipments or small scale plants. There are many refrigeration systems present for refrigeration and air condition purpose. Such as air refrigeration, vapour compression, vapour absorption etc. In this paper we have presented the concept of combined vapour absorption and vapour compression refri...

  17. Experimental Investigation of a Three-Bed Adsorption Refrigeration Chiller Employing an Advanced Mass Recovery Cycle

    Directory of Open Access Journals (Sweden)

    Atsushi Akisawa

    2009-07-01

    Full Text Available The performance of an advanced three-bed adsorption chiller with a mass recovery cycle has been experimentally investigated in the present study. The temperature and pressure of various components of the chiller were monitored to observe the dynamic behaviour of the chiller. The performances in terms of the coefficient of performance (COP and specific cooling power (SCP were compared with a conventional single stage. The results show that the proposed cycle produces COP and SCP values superior to those of the conventional single stage cycle for heat source temperature below 75 °C.

  18. Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair

    Directory of Open Access Journals (Sweden)

    Atsushi Akisawa

    2010-10-01

    Full Text Available A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP as compared to that of the conventional single-stage cycle for driving temperatures between 100 °C and 150 °C in which the average cycle chilled water temperature is fixed at 9 °C. Moreover, the COP of the double-effect cycle is more than twice that of the single-stage cycle when the temperature reaches 130 °C. It is also observed that the adsorbent mass ratio of the high temperature cycle (HTC to the low temperature cycle (LTC affects the performance of the double-effect adsorption refrigeration cycle.

  19. THERMODYNAMIC ANALYSIS AND SIMULATION OF A NEW COMBINED POWER AND REFRIGERATION CYCLE USING ARTIFICIAL NEURAL NETWORK

    Directory of Open Access Journals (Sweden)

    Hossein Rezvantalab

    2011-01-01

    Full Text Available In this study, a new combined power and refrigeration cycle is proposed, which combines the Rankine and absorption refrigeration cycles. Using a binary ammonia-water mixture as the working fluid, this combined cycle produces both power and refrigeration output simultaneously by employing only one external heat source. In order to achieve the highest possible exergy efficiency, a secondary turbine is inserted to expand the hot weak solution leaving the boiler. Moreover, an artificial neural network (ANN is used to simulate the thermodynamic properties and the relationship between the input thermodynamic variables on the cycle performance. It is shown that turbine inlet pressure, as well as heat source and refrigeration temperatures have significant effects on the net power output, refrigeration output and exergy efficiency of the combined cycle. In addition, the results of ANN are in excellent agreement with the mathematical simulation and cover a wider range for evaluation of cycle performance.

  20. Design and performance characteristics of solar adsorption refrigeration system using parabolic trough collector: Experimental and statistical optimization technique

    International Nuclear Information System (INIS)

    Highlights: • The successes of using olive waste/methanol as an adsorbent/adsorbate pair. • The experimental gross cycle coefficient of performance obtained was COPa = 0.75. • Optimization showed expanding adsorbent mass to a certain range increases the COP. • The statistical optimization led to optimum tank volume between 0.2 and 0.3 m3. • Increasing the collector area to a certain range increased the COP. - Abstract: The current work demonstrates a developed model of a solar adsorption refrigeration system with specific requirements and specifications. The recent scheme can be employed as a refrigerator and cooler unit suitable for remote areas. The unit runs through a parabolic trough solar collector (PTC) and uses olive waste as adsorbent with methanol as adsorbate. Cooling production, COP (coefficient of performance, and COPa (cycle gross coefficient of performance) were used to assess the system performance. The system’s design optimum parameters in this study were arrived to through statistical and experimental methods. The lowest temperature attained in the refrigerated space was 4 °C and the equivalent ambient temperature was 27 °C. The temperature started to decrease steadily at 20:30 – when the actual cooling started – until it reached 4 °C at 01:30 in the next day when it rose again. The highest COPa obtained was 0.75

  1. The present and future of residential refrigeration, power generation and energy storage

    International Nuclear Information System (INIS)

    Based upon the fast development of energy efficiency, energy safety and use of renewable and sustainable energy, various energy systems related to residential refrigeration, power generation and storage have been developing. Some of them are in large scale application, while others are still under development. Current status of residential refrigeration, power generation and energy storage technologies have been briefly summarized in this paper. Also, future residential refrigeration, power generation and energy storage technologies are highlighted, and some roadmaps are discussed. -- Highlights: ▸ Current status and future development of residential refrigeration have been briefly summarized and discussed. ▸ Current status and future development of power generation have been briefly summarized and discussed. ▸ Current status and future development of energy storage have been briefly summarized and discussed

  2. Experimental Study On Thermal Wave Type Adsorption Refrigeration System Working On A Pair Of Activated Carbon And Methanol

    Directory of Open Access Journals (Sweden)

    Grzebielec Andrzej

    2015-12-01

    Full Text Available The aim of the study was to examine the efficiency of the thermal wave type adsorption refrigerating equipment working on a pair of activated carbon and methanol. Adsorption units can work in trigeneration systems and in applications driven by waste heat. They can be built also as a part of hybrid sorption-compressor systems, and they are very popular in solar refrigeration systems and energy storage units. The device examined in this study operates in a special mode called thermal wave. This mode allows to achieve higher efficiency rates than the normal mode of operation, as a significant contributor to transport heat from one to the other adsorber. To carry out the experiment a test bench was built, consisting of two cylindrical adsorbers filled with activated carbon, condenser, evaporator, oil heater and two oil coolers. Thermal oil circulation was responsible for providing and receiving heat from adsorbers. In order to perform the correct action a special control algorithm device was developed and implemented to keep the temperature in the evaporator at a preset level. The experimental results show the operating parameters changes in both adsorbers. Obtained COP (coefficient of performance for the cycle was 0.13.

  3. Combined Cycle for Power Generation and Refrigeration Using Low Temperature Heat Sources

    OpenAIRE

    Vijay Chauhan; P. Anil Kishan; Sateesh Gedupudi

    2014-01-01

    A combined refrigeration and power cycle, which uses ammonia-water as the working fluid, is proposed by combining Rankine and vapour absorption cycles with an advantage of varying refrigeration capacity to power output ratio. The study investigates the usage of low temperature heat sources for the cycle operation. Results of parametric analysis are presented, which show the scope for optimization. Results of thermodynamic optimization of the cycle for second law efficiency performed using gen...

  4. Design and dynamic behaviour of a cold storage system combined with a solar powered thermoacoustic refrigerator

    International Nuclear Information System (INIS)

    A heat powered thermoacoustic refrigerator consists in a thermoacoustic engine that produces acoustic work utilizing heat, coupled to a thermoacoustic cooler that converts this acoustic energy into cooling effect. These machines have already proved their capability in laboratory or in space refrigeration. Previous studies have also demonstrated the possibility of using concentrated solar energy as thermal energy sources for low power heat driven thermoacoustic refrigerators. As other solar refrigeration systems, even if the cooling demand generally increases with the intensity of the solar radiation, one of the major difficulties is to insure a frigorific power supply when there is no, or low, solar radiation. The aim of this work is to study a kW scale solar thermoacoustic refrigerator capable to reach temperatures of the industrial refrigeration domain. This refrigerator is combined with a latent cold storage in order to guarantee a sufficient cooling capacity to face to refrigeration loads in spite of the production fluctuations. A description of the studied prototype is done and the model developed to describe the transient behaviour of the main components of this machine is introduced. The results obtained with a simulation of one week with real solar radiations are presented and the behaviour and the energetic performances of the entire system are analysed. Finally the impact of the sizing of the cold storage system is discussed. With the best storage design, the system is capable to supply a cooling power of 400 W at a temperature equal or lower than −20 °C with an average Coefficient Of Performance of the solar thermoacoustic refrigerator equal to 21%

  5. Parametric analysis for a new combined power and ejector-absorption refrigeration cycle

    International Nuclear Information System (INIS)

    A new combined power and ejector-absorption refrigeration cycle is proposed, which combines the Rankine cycle and the ejector-absorption refrigeration cycle, and could produce both power output and refrigeration output simultaneously. This combined cycle, which originates from the cycle proposed by authors previously, introduces an ejector between the rectifier and the condenser, and provides a performance improvement without greatly increasing the complexity of the system. A parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the cycle performance. It is shown that heat source temperature, condenser temperature, evaporator 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. It is evident that the ejector can improve the performance of the combined cycle proposed by authors previously.

  6. Performance analysis of a novel power/refrigerating combined-system driven by the low-grade waste heat using different refrigerants

    International Nuclear Information System (INIS)

    In this paper, a novel power/refrigerating combined-system driven by the low-grade waste heat of the flue gas was introduced. It coupled a transcritical organic Rankine cycle with a vapor compression refrigeration cycle. In order to understand basic characteristics of this novel combined-system, a detailed performance analysis was performed. Results show that the turbine inlet pressure, flue gas inlet temperature and condensation temperature are three important parameters influencing system performance. During the increase of the turbine inlet pressure, the refrigeration capacity and the exergy efficiency exhibit the maximum values. However, with the increase of the flue gas inlet temperature and the decrease of the condensation temperature, both the refrigeration capacity and the exergy efficiency corresponding to the optimal turbine inlet pressure increase. The use of regenerator can improve the system performance and reduce the optimal turbine inlet pressure. Under partial refrigeration load, there is a linear relationship between the electricity output and the refrigeration capacity at a fixed work output from the turbine. The total irreversible loss decreases and the exergy efficiency increases with the decrease of the power ratio. Finally, after screening and comparing various potential working fluids, R134a is recommended as the working fluid of this novel combined-system. - Highlights: • A novel power/refrigerating combined-system using three refrigerants is proposed. • Performance analysis on this combined-system is performed based on thermodynamics. • Variations of refrigeration capacity and efficiency with main parameters are given. • After screening different refrigerants, R134a is recommended as the working fluid

  7. Theoretical Models for the Cooling Power and Base Temperature of Dilution Refrigerators

    CERN Document Server

    Wikus, Patrick

    2010-01-01

    He-3/He-4 dilution refrigerators are widely used for applications requiring continuous cooling at temperatures below approximately 300 mK. Despite of the popularity of these devices in low temperature physics, the thermodynamic relations underlying the cooling mechanism of He-3/He-4 refrigerators are very often incorrectly used. Several thermodynamic models of dilution refrigeration have been published in the past, sometimes contradicting each other. These models are reviewed and compared with each other over a range of different He-3 flow rates. In addition, a new numerical method for the calculation of a dilution refrigerator's cooling power at arbitrary flow rates is presented. This method has been developed at CERN's Central Cryogenic Laboratory. It can be extended to include many effects that cannot easily be accounted for by any of the other models, including the degradation of heat exchanger performance due to the limited number of step heat exchanger elements, which can be considerable for some design...

  8. Improved Regenerative Sorbent-Compressor Refrigerator

    Science.gov (United States)

    Jones, Jack A.

    1992-01-01

    Conceptual regenerative sorbent-compressor refrigerator attains regeneration efficiency and, therefore, overall power efficiency and performance greater than conventional refrigerators. Includes two fluid loops. In one, CH2FCF3 (R134a) ciculates by physical adsorption and desorption in four activated-charcoal sorption compressors. In other, liquid or gas coolant circulated by pump. Wave of regenerative heating and cooling propagates cyclically like peristatic wave among sorption compressors and associated heat exchangers. Powered by electricity, oil, gas, solar heat, or waste heat. Used as air conditioners, refrigerators, and heat pumps in industrial, home, and automotive applications.

  9. Application of waste heat powered absorption refrigeration system to the LNG recovery process

    Energy Technology Data Exchange (ETDEWEB)

    Kalinowski, Paul; Hwang, Yunho; Radermacher, Reinhard [Center for Environmental Energy Engineering, Department of Mechanical Engineering, University of Maryland, College Park, MD 20742 (United States); Al Hashimi, Saleh; Rodgers, Peter [The Petroleum Institute, Abu Dhabi (United Arab Emirates)

    2009-06-15

    The recovery process of the liquefied natural gas requires low temperature cooling, which is typically provided by the vapor compression refrigeration systems. The usage of an absorption refrigeration system powered by waste heat from the electric power generating gas turbine could provide the necessary cooling at reduced overall energy consumption. In this study, a potential replacement of propane chillers with absorption refrigeration systems was theoretically analyzed. From the analysis, it was found that recovering waste heat from a 9 megawatts (MW) electricity generation process could provide 5.2 MW waste heat produced additional cooling to the LNG plant and save 1.9 MW of electricity consumption. Application of the integrated cooling, heating, and power is an excellent energy saving option for the oil and gas industry. (author)

  10. Qualification testing of solar photovoltaic powered refrigerator freezers for medical use in remote geographic locations

    Science.gov (United States)

    Kaszeta, W. J.

    1982-01-01

    One of the primary obstacles to the application of vaccination in developing countries is the lack of refrigerated storage. Vaccines exposed to elevated temperatures suffer a permanent loss of potency. Photovoltaic (PV) powered refrigerator/freezer (R/F) units could surmount the problem of refrigeration in remote areas where no reliable commercial power supply is available. The performance measurements of two different models of PV powered R/F units for medical use are presented. Qualification testing consisted of four major procedures: no-load pull down, ice making, steady-state (maintenance), and holdover. Both R/F units met the major World Health Organization (WHO) requirements. However, the testing performed does not provide complete characterization of the two units; such information could be derived only from further extensive test procedures.

  11. Dynamic modeling of adsorption refrigerators for systm simulation; Dynamische Modellierung von Adsorptionskaelteanlagen fuer Systemsimulation

    Energy Technology Data Exchange (ETDEWEB)

    Dalibard, Antoine; Eicker, Ursula [Hochschule fuer Technik Stuttgart (Germany). Zentrum fuer nachhaltige Energietechnik; Ziegler, Felix [Technische Univ. Berlin (Germany). Inst. fuer Energietechnik, KT2

    2012-07-01

    The present paper deals with the dynamic modelling of two beds adsorption chillers with a special focus on the heat and mass recovery processes. A physical model able to calculate different heat recovery processes as well as mass recovery has been developed and implemented in the transient simulation environment TRNSYS. The main parameters required by the model and the modelling approach used are presented. Several concepts of heat recovery are presented and discussed. Also the concept of mass recovery is described. The model parameters have been adjusted to fit measurement data of an existing large capacity adsorption chiller (350 kW). This fitted model has been used to investigate the influence of the different heat recovery concepts on the chiller performance in steady state conditions. Depending on the concepts, the thermal COP can be increased by 10 to 30% in comparison with a cycle without heat recovery. Using mass recovery allows to increase the thermal COP by more than 10% and the cooling capacity by 2.5%. Combining both heat and mass recovery results in 35% COP improvement without reducing the cooling capacity. Comparing to other existing models, the model presents some advantages. It can simulate different heat recovery schemes and includes the possibility to calculate mass recovery between the two chambers. This model can be used for two beds adsorption chillers using different working pairs as silica-gel/water. Additionally, the model can be used for system simulation in order to investigate the influence of the transient behaviour of adsorption chillers on other components like cooling towers, solar collectors, buildings.. Further works will focus on the control optimization of adsorption chiller(s) at part load conditions. Also the primary energy savings potential of solar cooling systems equipped with adsorption chillers by using advanced controls will be investigated.

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

    Science.gov (United States)

    Chattopadhyay, S.; Mondal, P.; Ghosh, S.

    2016-07-01

    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 (rp) 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 and GT-TIT.

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

    DEFF Research Database (Denmark)

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

    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, the......, and novel incorporation of the evaporation temperature set-point into optimization problem, the convex optimization problem is formulated within the MPC scheme. The method is applied to a simulation benchmark of large-scale refrigeration systems including several medium and low temperature cold...

  14. Simulation of chip-size electrocaloric refrigerator with high cooling-power density

    Science.gov (United States)

    Gu, Haiming; Craven, Brent; Qian, Xiaoshi; Li, Xinyu; Cheng, Ailan; Zhang, Q. M.

    2013-03-01

    The large electrocaloric effect that found in ferroelectric polymers creates unique opportunity for developing high performance chip scale solid state refrigerator. This letter presents a finite volume simulation study and shows that by employing solid state regenerators and the micro-heat pumping mechanism used in the thermoacoustic cooling, a compact Electrocaloric Oscillatory Refrigeration (ECOR) device can be realized. The simulation results demonstrate that a 1 cm-long ECOR device can provide 9 W/cm3 volumetric cooling power density at 20 K temperature span. By tuning the device parameters in the model, the ECOR can reach more than 50% of the Carnot efficiency.

  15. Performance analysis of solar powered absorption refrigeration system

    Science.gov (United States)

    Abu-Ein, Suleiman Qaseem; Fayyad, Sayel M.; Momani, Waleed; Al-Bousoul, Mamdouh

    2009-12-01

    The present work provides a detailed thermodynamic analysis of a 10 kW solar absorption refrigeration system using ammonia-water mixtures as a working medium. This analysis includes both first law and second law of thermodynamics. The coefficient of performance (COP), exergetic coefficient of performance (ECOP) and the exergy losses (Δ E) through each component of the system at different operating conditions are obtained. The minimum and maximum values of COP and ECOP were found to be at 110 and 200°C generator temperatures respectively. About 40% of the system exergy losses were found to be in the generator. The maximum exergy losses in the absorber occur at generator temperature of 130°C for all evaporator temperatures. A computer simulation model is developed to carry out the calculations and to obtain the results of the present study.

  16. Evaluation of the Super Efficient Refrigerator Program (SERP) in the Bonneville Power Administration service territory

    Energy Technology Data Exchange (ETDEWEB)

    Lee, A.D.; Conger, R.L.

    1996-06-01

    The Super Efficient Refrigerator Program (SERP) is a collaborative utility program intended to transform the market for energy-efficient and environmentally friendly refrigerators. it is one of the first examples of large-scale {open_quotes}market transformation{close_quotes} energy efficiency program. This report documents the evaluation of SERP ({open_quotes}the Program{close_quotes}) in the Bonneville Power Administration`s (Bonneville`s) service territory. Pacific Northwest National Laboratory (PNNL) conducted this evaluation for Bonneville. This study includes the process evaluation, preliminary impact evaluation, and market transformation assessment. It is based on site visits and interviews with refrigerator dealers and manufacturers, industry data, and Bonneville information. Results from this study are compared with those from a parallel study that examines the Program across the 24 participating utilities.

  17. Exergy analysis, parametric analysis and optimization for a novel combined power and ejector refrigeration cycle

    International Nuclear Information System (INIS)

    A new combined power and refrigeration cycle is proposed, which combines the Rankine cycle and the ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. It can be driven by the flue gas of gas turbine or engine, solar energy, geothermal energy and industrial waste heats. An exergy analysis is performed to guide the thermodynamic improvement for this cycle. And a parametric analysis is conducted to evaluate the effects of the key thermodynamic parameters on the performance of the combined cycle. In addition, a parameter optimization is achieved by means of genetic algorithm to reach the maximum exergy efficiency. The results show that the biggest exergy loss due to the irreversibility occurs in heat addition processes, and the ejector causes the next largest exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output, refrigeration output and exergy efficiency of the combined cycle. The optimized exergy efficiency is 27.10% under the given condition.

  18. A rocket-borne He-3 refrigerator

    Science.gov (United States)

    Duband, L.; Alsop, D.; Lange, A.; Kittel, P.

    1990-01-01

    A self-contained, recyclable He-3 refrigerator suitable for use in space has been developed. The refrigerator is compact, has no moving parts, and requires only electrical connections and thermal contact in order to operate from a 2 K cold stage. A charcoal adsorption pump is used to efficiently condense and cool the He-3. Sintered copper confines the He-3 to the evaporator in zero-gravity and, in fact, allows the refrigerator to operate upside-down in the laboratory. Mounted on a 2 K cold stage, the refrigerator provides 100 microwatts of cooling power at 346 mK, with a 7 hour hold time. On a 1.5 K cold stage, the lowest temperature achieved is 277 mK. The refrigerator has been vibration tested at 7.5 G amplitude from 30 to 400 Hz and 15 G amplitude from 400 to 2000 Hz.

  19. Effects of low-E shields on the performance and power use of a refrigerated display case

    Energy Technology Data Exchange (ETDEWEB)

    Faramarzi, R.T.; Woodworth-Szleper, M.L.

    1999-07-01

    This paper discusses a test to evaluate the impact of low-emissivity aluminum shields on the power use and thermal performance of a multi-deck display case typically used in supermarkets for storing dairy products. The refrigerating system's critical temperature and pressure points were tracked during the test, and the readings were then utilized to quantify various heat transfer and power-related parameters of the refrigeration cycle. It was found that using shields for extended hours of operation provides the most reduction in refrigeration load and power use.

  20. Effect of high entropy magnetic regenerator materials on power of the GM refrigerator

    International Nuclear Information System (INIS)

    In previous work the authors have proved that heavy rare earth compounds with low magnetic transition temperature Tc are very useful as regenerator materials in low temperature range. Applying the magnetic material Er3Ni particles to the 2nd regenerator of the GM refrigerator, they were able to reach the 2 K range but could not obtain high refrigeration power at 4.2 K. This is thought to be due to the temperature dependence of the magnetic specific heat. They present here a method by which high refrigeration power is obtained at low temperature. The simplest means of obtaining high power is with a hybrid structure regenerator which is composed of two kinds of magnetic materials, high Tc and low Tc materials. Computer simulation and experiments were carried out to verify the superiority of the hybrid regenerator. The authors succeeded experimentally in obtaining the high power of ∼ 1.1 watt at 4.2 K. They will report other detailed results and discuss developing way of the magnetic regenerator in future

  1. Measurements of satellite refrigerator compressor power consumption and efficiency

    International Nuclear Information System (INIS)

    Each of the thirty compressors installed around the ring and at switchyard is an oil-injected, two-stage, Mycom screw compressor, driven by either a 350 hp or 400 hp motor. The reader is referred to TM1198 by John Satti for a detailed description of these compressors and the associated equipment. Since the power consumed by these compressors is a major operating expense for our accelerator, we were interested in measuring the power consumption and efficiency of our compressors. Two compressors were studied in detail - one having a GE 350 hp motor (F0 No. 2) and one a new GE 400 hp high efficiency motor (F0 No. 1). Data were taken for each compressor with the high stage always fully loaded. These data and values calculated from the data are tabulated

  2. Using solar-powered refrigeration for vaccine storage where other sources of reliable electricity are inadequate or costly.

    Science.gov (United States)

    McCarney, Steve; Robertson, Joanie; Arnaud, Juliette; Lorenson, Kristina; Lloyd, John

    2013-12-01

    Large areas of many developing countries have no grid electricity. This is a serious challenge that threatens the continuity of the vaccine cold chain. The main alternatives to electrically powered refrigerators available for many years--kerosene- and gas-driven refrigerators--are plagued by problems with gas supply interruptions, low efficiency, poor temperature control, and frequent maintenance needs. There are currently no kerosene- or gas-driven refrigerators that qualify under the minimum standards established by the World Health Organization (WHO) Performance, Quality, and Safety (PQS) system. Solar refrigeration was a promising development in the early 1980s, providing an alternative to absorption technology to meet cold chain needs in remote areas. Devices generally had strong laboratory performance data; however, experience in the field over the years has been mixed. Traditional solar refrigerators relied on relatively expensive battery systems, which have demonstrated short lives compared to the refrigerator. There are now alternatives to the battery-based systems and a clear understanding that solar refrigerator systems need to be designed, installed, and maintained by technicians with the necessary knowledge and training. Thus, the technology is now poised to be the refrigeration method of choice for the cold chain in areas with no electricity or extremely unreliable electricity (less than 4h per average day) and sufficient sunlight. This paper highlights some lessons learned with solar-powered refrigeration, and discusses some critical factors for successful introduction of solar units into immunization programs in the future including: •Sustainable financing mechanisms and incentives for health workers and technicians are in place to support long-term maintenance, repair, and replacement parts. •System design is carried out by qualified solar refrigerator professionals taking into account the conditions at installation sites. •Installation and

  3. Weather Effect on the Solar Adsorption Air-conditioning System using Activated Carbon Fiber/Ethanol as Pair of Refrigeration: A Case Study of Malaysia

    OpenAIRE

    Alkhair M. Abdul Majeed; M.Y. Suliman; Sopian, K.

    2014-01-01

    This study indicates the simulation analysis of the solar adsorption cycle using the activated carbon fiber/ethanol as the pair of refrigeration in Malaysia. The heat source used was evacuated tube collectors. The cycle is used for the purpose of air-conditioning for two temperature levels, where the cooling load can be 7°C. TRNSYS simulation software was used to model the system with the weather data of Malaysia. The results showed that the weather has a high effect on the performance of the...

  4. Weather Effect on the Solar Adsorption Air-conditioning System using Activated Carbon Fiber/Ethanol as Pair of Refrigeration: A Case Study of Malaysia

    Directory of Open Access Journals (Sweden)

    Alkhair M. Abdul Majeed

    2014-02-01

    Full Text Available This study indicates the simulation analysis of the solar adsorption cycle using the activated carbon fiber/ethanol as the pair of refrigeration in Malaysia. The heat source used was evacuated tube collectors. The cycle is used for the purpose of air-conditioning for two temperature levels, where the cooling load can be 7°C. TRNSYS simulation software was used to model the system with the weather data of Malaysia. The results showed that the weather has a high effect on the performance of the cycle. Both the cooling capacity and the COP were calculated in this study.

  5. High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

    Directory of Open Access Journals (Sweden)

    Yuki Ueda

    2009-11-01

    Full Text Available This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coefficient of performance (COP and the specific cooling power (SCP, are compared with conventional cascading-without-mass-recovery and single-stage cycles. The paper also presents the effect of the adsorbent mass on performance. The results show that the proposed cycle with mass recovery produces as high of a COP as the COP that is produced by the conventional cascading cycle. However, it produces a lower SCP than that of the single-stage cycle.

  6. Refrigerating engineering

    International Nuclear Information System (INIS)

    This book gives a description of refrigerating engineering with introduction of refrigerating, abnormal refrigerating cycle and air compression refrigerator, refrigerant and simple steam compression refrigerating cycle, under-cooling cycle, plank cycle, multi-compression cycle, calculation for compressor and practice process of steam compression refrigerating, heat conduction, heat convection, heat radiation, compressor like booster, oil separator, gas purger, an vaporizer and the low-tension side device, operation of refrigerator, steam blast refrigerator, absorption refrigeration machine and application of refrigerating.

  7. Remote monitoring system for stand-alone photovoltaic power plants: The case study of a PV-powered outdoor refrigerator

    International Nuclear Information System (INIS)

    Highlights: • The paper is about an monitoring system for remote stand-alone PV systems. • The proposed system is based on a web application. • Daily reports allows off-line post-processing for efficiency and reliability evaluations. • Experimental measurements refer to a photovoltaic-powered outdoor refrigerator. - Abstract: This paper describes a monitoring architecture for stand-alone photovoltaic (SAPV) systems. For the proposed system a web application has been adopted, thus allowing an on-line monitoring and control of remote installations. Moreover, daily reports are elaborated and sent to the system operator. These data can be analysed off-line to calculate both energy performances indices and statistical values. Historical data analysis is useful not only to optimize the operation of the system but also to design a retrofit of the SAPV system. To check the effectiveness of the proposed remote monitoring system, the performance of a photovoltaic-powered outdoor refrigerator has been evaluated. In case of temperature-sensitive application, such as vaccines or perishable goods storage, critical operating conditions have been detected. Experimental measurements executed on a prototype, adapted for outdoor operation with a horizontal PV module, show that the refrigerator works adequately in the given place (Catania-Italy), where typical Mediterranean climate is present, if an additional vertical PV module is adopted

  8. The development of high cooling power and low ultimate temperature superfluid Stirling refrigerators

    Science.gov (United States)

    Patel, Ashok B.

    The superfluid Stirling refrigerator (SSR) is a recuperative Stirling cycle refrigerator which provides cooling to below 2 K by using a liquid 3He-4He mixture as the working fluid. In 1990, Kotsubo and Swift demonstrated the first SSR, and by 1995, Brisson and Swift had developed an experimental prototype capable of reaching a low temperature of 296 mK. The goal of this thesis was to improve these capabilities by developing a better understanding of the SSR and building SSR's with higher cooling powers and lower ultimate temperatures. This thesis contains four main parts. In the first part, a numerical analysis demonstrates that the optimal design and ultimate performance of a recuperative Stirling refrigerator is fundamentally different from that of a standard regenerative Stirling refrigerator due to a mass flow imbalance within the recuperator. The analysis also shows that high efficiency recuperators remain a key to SSR performance. Due to a quantum effect called Kapitza resistance, the only realistic and economical method of creating higher efficiency recuperators for use with an SSR is to construct the heat exchangers from very thin (12 μm - 25 μm thick) plastic films. The second part of this thesis involves the design and construction of these recuperators. This research resulted in Kapton heat exchangers which are leaktight to superfluid helium and capable of surviving repeated thermal cycling. In the third part of this thesis, two different single stage SSR's are operated to test whether the plastic recuperators would actually improve SSR performance. Operating from a high temperature of 1.0 K and with 1.5% and 3.0% 3He-4He mixtures, these SSR's achieved a low temperature of 291 mK and delivered net cooling powers of 3705 μW at 750 mK, 977 μW at 500 mK, and 409 μW at 400 mK. Finally, this thesis describes the operation of three versions of a two stage SSR. Unfortunately, due to experimental difficulties, the merits of a two stage SSR were not

  9. Technical and Economical Demands on 25K - 77K Refrigerators for Future HTS — Series Products in Power Engineering

    Science.gov (United States)

    Gromoll, B.

    2004-06-01

    For the future high temperature superconductivity, HTS, series products new refrigerators are essential. Demands are made on these which are only partly fulfilled by refrigerators available in the market today. This refers to cooling power, initial cost and in particular reliability. Without proper refrigeration techniques it will be almost impossible to bring HTS products to the market. Based on the experiences made by the construction and operation of HTS prototypes within our company, like the 400 kW motor, 1.2 MVA current limiter and 1 MVA traction-transformer provided with refrigerators which are available in the market today, criteria have been established to identify the future technical and economical requirements. These criteria apply to efficiency, maintainability, operation flexibility, feasibility of integration and performance/cost ratio. For the temperature range of 20 K to 77 K cooling with Gifford-McMahon, Pulse Tube, Stirling and Mixture-Cascade refrigerators are applicable. The development potential of these processes are compared for the different applications in future series products. Presented are the necessary steps towards reliable and economic refrigerators from the viewpoint of an equipment manufacturer. These are essential for a market entry in the year 2008.

  10. New York Power Authority/New York City Housing Authority refrigerator replacement program, first program year evaluation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, L.F.; Lewis, G. [Synertech Systems Corp., Syracuse, NY (United States); Pratt, R.G.; Miller, J. [Pacific Northwest National Lab., Richland, WA (United States)

    1997-08-01

    Acting as an energy services provider, the New York Power Authority (NYPA) has initiated a long-term project through which 20,000 refrigerators per year will be replaced with the most energy-efficient units possible in apartments managed by the New York City Housing Authority (NYCHA). Using bulk purchasing as an incentive to appliance manufacturers to produce energy-efficient refrigerators suitable for use in apartments, replaced in the first year of the program, which ended in December 1996. These units, kWh per year. Savings were determined by field testing and laboratory testing of 220 existing refrigerators and 56 newly-installed units. In the next program year, a 15.0-cubic-foot Maytag refrigerator, newly-designed in response to bulk purchasing incentives, is being installed. The new unit has a label rating of 437 kWh per year, 31 percent better than 1993 energy standards. Old refrigerators removed from apartments are {open_quotes}demanufactured{close_quotes} in an environmentally-appropriate way and both metals and refrigerants are recovered for reuse.

  11. Thermoelectric refrigerator

    Science.gov (United States)

    Park, Brian V. (Inventor); Smith, Jr., Malcolm C. (Inventor); McGrath, Ralph D. (Inventor); Gilley, Michael D. (Inventor); Criscuolo, Lance (Inventor); Nelson, John L. (Inventor)

    1996-01-01

    A refrigerator is provided which combines the benefits of superinsulation materials with thermoelectric devices and phase change materials to provide an environmentally benign system that is energy efficient and can maintain relatively uniform temperatures for extended periods of time with relatively low electrical power requirements. The refrigerator includes a thermoelectric assembly having a thermoelectric device with a hot sink and a cold sink. The superinsulation materials include a plurality of vacuum panels. The refrigerator is formed from an enclosed structure having a door. The vacuum panels may be contained within the walls of the enclosed structure and the door. By mounting the thermoelectric assembly on the door, the manufacturer of the enclosed structure is simplified and the overall R rating of the refrigerator increased. Also an electrical motor and propellers may be mounted on the door to assist in the circulation of air to improve the efficiency of the cold sink and the hot sink. A propeller and/or impeller is preferably mounted within the refrigerator to assist in establishing the desired air circulation flow path.

  12. Modelling and Assessment of the Capabilities of a Supermarket Refrigeration System for the Provision of Regulating Power

    DEFF Research Database (Denmark)

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

    is found to have time constants at 10 and 0.12 hours, indicating the potential for the system to provide exibility in both the long- and short-term. Direct- and indirect-control architectures are employed to simulate the demand response attainable from the refrigeration system. A number of complexities......This report presents an analysis of the demand response capabilities of a supermarket refrigeration system, with a particular focus on the suitability of this resource for participation in the regulating power market. An ARMAX model of the system is identified from experimental data, and the model...

  13. Experimental results and thermodynamic analysis of a natural gas small scale cogeneration plant for power and refrigeration purposes

    International Nuclear Information System (INIS)

    In this work, experimental results are reported for a small scale cogeneration plant for power and refrigeration purposes. The plant includes a natural gas microturbine and an ammonia/water absorption chiller fired by steam. The system was tested under different turbine loads, steam pressures and chiller outlet temperatures. An evaluation based on the 1st and 2nd Laws of Thermodynamics was also performed. For the ambient temperature around 24 °C and microturbine at full load, the plant is able to provide 19 kW of saturated steam at 5.3 bar (161 °C), corresponding to 9.2 kW of refrigeration at −5 °C (COP = 0.44). From a 2nd law point-of-view, it was found that there is an optimal chiller outlet temperature that maximizes the chiller exergetic efficiency. As expected, the microturbine presented the highest irreversibilities, followed by the absorption chiller and the HRSG. In order to reduce the plant exergy destruction, it is recommended a new design for the HRSG and a new insulation for the exhaust pipe. -- Highlights: • A small scale cogeneration plant for power and refrigeration is proposed and analyzed. • The plant is based on a microturbine and a modified absorption chiller. • The plant is analysed based on 1st and 2nd laws of thermodynamics. • Experimental results are found for different power and refrigeration conditions. • The plant proved to be technically feasible

  14. High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

    OpenAIRE

    Yuki Ueda; Atsushi Akisawa; Aep Saepul Uyun; Takahiko Miyazaki

    2009-01-01

    This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coef...

  15. Exergoeconomic analysis and multi-objective optimization of an ejector refrigeration cycle powered by an internal combustion (HCCI) engine

    International Nuclear Information System (INIS)

    Highlights: • Ejector refrigeration systems powered by HCCI engine is proposed. • A new two-dimensional model is developed for the ejector. • Multi-objective optimization is performed for the proposed system. • Pareto frontier is plotted for multi-objective optimization. - Abstract: Ejector refrigeration systems powered by low-grade heat sources have been an attractive research subject for a lot of researchers. In the present work the waste heat from exhaust gases of a HCCI (homogeneous charge compression ignition) engine is utilized to drive the ejector refrigeration system. Considering the frictional effects on the ejector wall, a new two-dimensional model is developed for the ejector. Energy, exergy and exergoeconomic analysis performed for the proposed system using the MATLAB software. In addition, considering the exergy efficiency and the product unit cost of the system as objective functions, a multi-objective optimization is performed for the system to find the optimum design variables including the generator, condenser and evaporator temperatures. The product unit cost is minimized while the exergy efficiency is maximized using the genetic algorithm. The optimization results are obtained as a set of optimal points and the Pareto frontier is plotted for multi-objective optimization. The results of the optimization show that ejector refrigeration cycle is operating at optimum state based on exergy efficiency and product unit cost when generator, condenser and evaporator work at 94.54 °C, 33.44 °C and 0.03 °C, respectively

  16. Exergy analysis and parametric optimization of three power and fresh water cogeneration systems using refrigeration chillers

    International Nuclear Information System (INIS)

    Three power and fresh water cogeneration systems that combine a GT (gas turbine) power plant and a RO (reverse osmosis) desalination system were compared based on the exergy viewpoint. In the first system, the GT and RO systems were coupled mechanically to form a base system. In the second and third systems, a VCR (vapor-compression refrigeration) cycle and a single-effect ACWater–LiBr (water/lithium bromide absorption chiller) were used, respectively, to cool the compressor inlet air and preheat the RO intake seawater via waste heat recovery in the VCR condenser and ACWater–LiBr absorber. A parametric analysis-based exergy was conducted to evaluate the effects of the key thermodynamic parameters including the compressor inlet air temperature and the fuel-mass flow rate on the system exergy efficiency. Parameter optimization was achieved using a GA (genetic algorithm) to reach the maximum exergy efficiency, where the thermodynamic improvement potentials of the systems were identified. The optimum values of performance for the three cogeneration systems were compared under the same conditions. The results showed that the cogeneration system with the AC is the best system among the three systems, since it can increase exergy and energy efficiencies as well as net power generation by 3.79%, 4.21%, and 38%, respectively, compared to the base system. - Highlights: • Development of a thermodynamic model of power and fresh water cogeneration systems. • Model determines the thermodynamic properties, energy and exergy efficiencies, and net power generation. • Parametric analysis of the cogeneration systems to investigate the effects of decision variables on the system exergy efficiency. • Optimization using a GA (genetic algorithm) to maximize system exergy efficiency. • Exergy analysis of the cogeneration systems to guide the thermodynamic improvement

  17. When to defrost a refrigerator, and when to remove the scale from the heat exchanger of a power plant

    Science.gov (United States)

    Bejan, Adrian; Vargas, Jose V. C.; Lim, Jong S.

    1995-02-01

    This paper demonstrates the existence of an optimal on/off sequence for operating a household refrigerator that accumulates ice on its evaporator coils. Experimentally it is shown that the rate of ice formation is constant in time. The optimal (intermittent) regime of operation determined in this paper minimizes the power required by the refrigerator, maintains the prescribed temperature of the cold space, and removes intermittently the ice layer. The second part of the paper proves that a similar strategy can be used for dealing with fouling in heat exchangers, i.e. for maximizing the power output of a power plant that is diminished by the formation of scale on its heat exchanger surfaces.

  18. Some comments about the comparison between a conventional and a solar powered absorption refrigeration system

    International Nuclear Information System (INIS)

    Two statements about the performance of solar refrigeration systems are discussed. First, concepts of efficiency and coefficient of performance are studied. Second, the influence of inflation and rise of fuel prices are considered, in relation to the comparison between solar and conventional refrigeration systems. (author)

  19. Model predictive control technologies for efficient and flexible power consumption in refrigeration systems

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Larsen, Lars F. S.; Edlund, Kristian;

    2012-01-01

    Considerable amounts of energy are consumed in supermarket refrigeration systems worldwide. Due to the thermal capacity of refrigerated goods and the rather simplistic control most commonly applied, there is a potential for distributing the system load over time in a more cost-optimal way. In thi...

  20. Modeling of a thermal adsorber powered by solar energy for refrigeration applications

    International Nuclear Information System (INIS)

    In this paper, we introduce a dynamic model of a thermal adsorber powered by solar energy. The system operates with silica gel (as an adsorbent) and water (as a refrigerant). The Finite Difference approximation was used; the obtained numerical model was then incorporated in a MATLAB code in order to solve the system of algebraic equations modeling heat and mass transfers. The real ambient temperature and solar radiation variations relative to a typical summer day in Fez (Morocco) are taken into account. The system is characterized by its simple design and can reach a SCOP (Solar Coefficient of Performance) of 0.15 under a condenser and evaporator temperatures of 27 °C and 5 °C respectively. Consequently, this installation can be an attractive solution to meet positive cooling needs (medicine and food storage) in off-grid electricity regions. It can be also proposed in humanitarian actions in Africa. - Highlights: • Numerical simulation of an adsorber powered by solar energy is investigated. • The proposed system can provide cooling in off-electricity regions. • The system SCOP can reach a value of 0.15 under Morocco climate during summer

  1. Solar-powered cooling system

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  2. Solar photovoltaic powered refrigerators/freezers for medical use in remote geographic locations

    Science.gov (United States)

    Darkazalli, G.; Hein, G. F.

    1983-01-01

    One of the obstacles preventing widespread immunication against disease is the virtual absence of reliable, low maintenance refrigeration systems for storage of vaccines in remote geographic locations. A system which consists of a solar photovoltaic cell array and an integrated refrigerator/freezer-energy storage unit is discussed herein. The array converts solar radiation into direct current (DC) electricity with no moving parts and no intermediate steps. A detailed description of the refrigeration system, its design and an analysis thereof, performance test procedures, and test results are presented. A system schematic is also provided.

  3. A thermodynamic analysis of a solar-powered jet refrigeration system

    Science.gov (United States)

    Lansing, F. L.; Chai, V. W.

    1980-01-01

    The article describes and analyzes a method of using solar energy to drive a jet refrigeration system. A new technique is presented in the form of a performance nomogram combining the energy and momentum equations to determine the performance characteristics. A numerical example, using water as the working fluid, is given to illustrate the nomogram procedure. The resulting coefficient of performance was found comparable with other refrigeration systems such as the solar-absorption system or the solar-Rankine turbocompressor system.

  4. Thermodynamic analysis of a combined reheat regenerative thermal power plant and water–LiBr vapor absorption refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • Thermodynamic analysis of a combined power-absorption cooling system is provided. • Effect of important operating parameters on combined cycle performance is studied. • Compares performance of combined cycle with power cycle without absorption system. • Gives quantitative comparison of power cycle performance with and without water heater. • Analysis on vapor power and water–LiBr absorption refrigeration system is not available. - Abstract: Detail thermodynamic analysis of a combined reheat regenerative steam turbine (ST) based power cycle and water–LiBr vapor absorption refrigeration system (VARS) is presented in this study. The power cycle uses one open and one closed water heater (CWH) for purpose of feed water heating. A parametric analysis is performed to investigate the effects of boiler pressure, fuel flow rate, VARS evaporator cooling load and operating temperatures on performance of the topping power cycle and bottoming VARS. Further a performance comparison of the combined power and cooling plant is made with the power plant (without VARS) to quantify the performance variation due to VARS integration. Comparative performance analysis is also provided for the power plant (without VARS) with and without the CWH in the plant. The analysis indicates that the fuel flow rate and boiler pressure affects only the power cycle performance while the evaporator cooling load and VARS components’ operating temperature has its combined effect both on the power and the cooling system, the evaporator cooling load is the most crucial among them. A sensitive analysis shows that the power and efficiency of the topping cycle change very little with VARS operating temperatures. VARS coefficient of performance is more sensitive to the change in condenser and absorber temperature compared to change in generator and evaporator temperature

  5. Upgrading of refrigeration units in nuclear power plant: An optimized approach to do justice to governmental restrictions

    International Nuclear Information System (INIS)

    Stringent regulations to reduce the use of chlorofluorocarbons (CFC) and halogenated chlorofluorocarbons (HCFC) have been set into force by many European countries. A ban for new plants containing HCFCs in 2005 and a total ban of HCFCs in 2020 are discussed within the European Community. Siemens-KWU and Sulzer Escher Wyss have developed a well-proofed procedure to solve the CFC problem for existing refrigeration systems in nuclear power plants. The new refrigerants are fluorinated hydrocarbons and for the centrifugal water chiller R134a is best suited. Prior to the market introduction toxicity, short and long term health effects, inflammability and stability of R134a have been investigated. The mechanical examination included wear, corrosion, lubrication and resistance to decomposition. A well-proven procedure was established which ensures the owner of the plant and the supplier best results

  6. Upgrading of refrigeration units in nuclear power plant: An optimized approach to do justice to governmental restrictions

    Energy Technology Data Exchange (ETDEWEB)

    Gregor, Klaus [Siemens-KWU, Erlangen (Germany); Reinhart, Anton [Sulzer Escher Wyss, Lindau (Germany)

    1998-07-01

    Stringent regulations to reduce the use of chlorofluorocarbons (CFC) and halogenated chlorofluorocarbons (HCFC) have been set into force by many European countries. A ban for new plants containing HCFCs in 2005 and a total ban of HCFCs in 2020 are discussed within the European Community. Siemens-KWU and Sulzer Escher Wyss have developed a well-proofed procedure to solve the CFC problem for existing refrigeration systems in nuclear power plants. The new refrigerants are fluorinated hydrocarbons and for the centrifugal water chiller R134a is best suited. Prior to the market introduction toxicity, short and long term health effects, inflammability and stability of R134a have been investigated. The mechanical examination included wear, corrosion, lubrication and resistance to decomposition. A well-proven procedure was established which ensures the owner of the plant and the supplier best results.

  7. Experimental study on ejector refrigeration system powered by low grade heat

    International Nuclear Information System (INIS)

    An ejector refrigeration system has been designed and constructed to operate with hot water. Such a refrigeration system, designed for low pressure refrigerants, can be operated using energy sources such as solar energy, geothermal energy and waste heat. In this study, the effects of the main operating parameters on system performance were experimentally investigated using R-11 as the working fluid and keeping constant the position of the primary nozzle end at the inlet plane of the mixing chamber section of the ejector. The experimental study was performed over a range of vapor generator temperatures from about 90 to 102 oC, evaporator temperatures from 0 to 16 oC and condenser pressures from 114 to 143 kPa, and a COP up to 0.25 was obtained. It was seen that if higher cooling capacity and also lower evaporator temperature are desired from the system, the vapor generator temperature should be increased considerably

  8. Design of oil-free simple turbo type 65 K/6 KW helium and neon mixture gas refrigerator for high temperature superconducting power cable cooling

    Science.gov (United States)

    Saji, N.; Asakura, H.; Yoshinaga, S.; Ishizawa, T.; Miyake, A.; Obata, M.; Nagaya, S.

    2002-05-01

    For the requirement of HTS facility cooling, we propose oil-free simple turbo-type refrigerator. The working gas is a helium and neon mixture. Two single-stage turbo compressors and two expansion turbines are applied to the cycle. The rotor consists of the compressor impeller, turbine impeller and driving motor, and is supported by foil type gas bearing. The refrigerator requires two rotating machines with excellent reliability and compactness, and the motor power required is 72.5 kW for a refrigeration load of 6 kW. For the cooling of power cable, sub-cooled pressurized liquid nitrogen and a circulation pump must be provided. If the estimated distance between inter-cooling stations is quite long, for example 5 km, plural refrigerators may be set up on one cooling station.

  9. Prospects in magnetic refrigeration

    International Nuclear Information System (INIS)

    Cryogenic applications extend over the whole range of power types: from small power types with infra-red detection. Satellite communication, cryopumping and the medical applications of superconductors to the large power types with cryogenic alternators and superconductor magnets for fusion. The question actually arises wether magnetic refrigeration cycles can have higher reliability and higher efficiency than classical gas refrigerating machines. Before discussing the state of the art, we will point out some general thermodynamic conditions that have to be respected for magnetic cycles as for gas cycles. Magnetic Carnot cycle refrigerators are now capable of pumping heat efficiently when all the cycle is executed in liquid helium temperature range

  10. Optimal refrigerator.

    Science.gov (United States)

    Allahverdyan, Armen E; Hovhannisyan, Karen; Mahler, Guenter

    2010-05-01

    We study a refrigerator model which consists of two n -level systems interacting via a pulsed external field. Each system couples to its own thermal bath at temperatures T h and T c, respectively (θ ≡ T c/T h Carnot efficiency [formula: see text]. The lower bound is reached in the equilibrium limit θ → 1. The Carnot bound is reached (for a finite power and a finite amount of heat transferred per cycle) for ln n > 1. If the above maximization is constrained by assuming homogeneous energy spectra for both systems, the efficiency is bounded from above by ζ CA and converges to it for n > 1. PMID:20866207

  11. 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...

  12. Oxygen chemisorption compressor study for cryogenic J-T refrigeration

    Science.gov (United States)

    Jones, Jack A.; Blue, Gary D.

    1987-01-01

    Over twenty potentially reversible heat-powered oxide reactions have been studied and/or tested to determine their potential use as thermochemical oxygen compressors for cryogenic J-T LO2 refrigerators. One gas-solid compound family, Pr(1-n)Ce(n)O(x), proved to be completely reversible with fast kinetics for all pressure ranges tested below 650 C. With a heat-powered charcoal/methane physical adsorption upper stage and a Pr(1-n)Ce(n)O(x) chemisorption lower stage, temperatures should be attainable in the 55-80 K range for less power and over five times less weight than for charcoal/nitrogen sorption refrigeration systems. Total system power requirements with a hydride chemisorption lower stage (10 K to 7 K minimum) are about three times less than any mechanical refrigerator, and spacecraft refrigeration weights are about twenty times less. Due to the lack of wear-related moving parts in sorption refrigerators, life expectancy is at least ten years, and there essentially no vibration.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-09-01

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

  14. 2013 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    These proceedings cover the following main topics: cryoengineering - superconduction / energy storage; cryoapplications in biology and medicine; metrology; adsorption processes; condensation/evaporation; working fluids / simulation; ice production; plants and compressors; expansion and ejectors or recooling; use of cooling (passenger car air conditioning, supermarket); refrigerants; plant efficiency; emissions and legislation; air conditioning and use of heat pumps; air quality and control; building technology and block-type thermal power stations.

  15. Ionic Refrigerator

    Science.gov (United States)

    Richter, R.

    1984-01-01

    With no moving parts, proposed refrigerator has long life. Thermal energy of refrigeration process transported by hydrogen ions that go through three phase changes in absorbing heat and three phase changes in dissipating heat.

  16. Energy Efficient Refrigeration and Flexible Power Consumption in a Smart Grid

    OpenAIRE

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

    2011-01-01

    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...

  17. Recent Progress in Power Refrigeration below 2 K for Superconducting Accelerators

    CERN Document Server

    Claudet, Serge

    2005-01-01

    As a result of technico-economical optimization and quest for increased performance, 2 K cryogenics is now present in large accelerator projects using superconducting magnets or acceleration cavities. Consequently, large cryogenic systems producing refrigeration capacity below 2 K in the kW range and with high efficiency over a large dynamic range are needed. After CEBAF and SNS, this is the case for the Large Hadron Collider (LHC) project at CERN for which eight 2.4 kW @ 1.8 K refrigeration units are needed to cool each a 3.3 km long sector of high-field magnets. Combining cold hydrodynamic compressors in series with warm volumetric compressors, complete pre-series units as well as sets of series cold compressors have been intensively tested and validated from two different industrial suppliers. After recalling the possible 2 K refrigeration cycles and their comparative merits, this paper describes the specific features of the LHC system and presents the achieved performance with emphasis on the progress in...

  18. Study on cyclic characteristics of the solar-powered adsorption cooling system

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    According to the typical variable heat source of solar energy and the unsteady adsorption process of adsorption chiller,the research of cyclic transient characteristics of the solar-powered adsorption cooling system is presented in this work.A mathematic model of the whole system including the model of adsorption chiller,which reveals the transient operation process of the solar-powered adsorption cooling system,is developed and verified by experimental data.On the basis of the simulated results,the transient characteristics and the overall performance of the system,not only in the traditional open cycle mode but also in closed cycle mode,are both analyzed theoretically.Furthermore,the influence of parameters matching of components configuration and operation process on the cyclic characteristics of the system,such as the solar collector area,the water tank capacity and the chiller startup temperature,are discussed.The research in this work may play a very important role in optimizing the system cyclic process and improving the system adaptability especially under the condition of variable heat source.

  19. Study on cyclic characteristics of the solar-powered adsorption cooling system

    Institute of Scientific and Technical Information of China (English)

    WU JingYi; LI Sheng; HU YanFei

    2009-01-01

    According to the typical variable heat source of solar energy and the unsteady adsorption process of adsorption chiller, the research of cyclic transient characteristics of the solar-powered adsorption cooling system is presented in this work. A mathematic model of the whole system including the model of adsorption chiller, which reveals the transient operation process of the solar-powered adsorption cooling system, is developed and verified by experimental data. On the basis of the simulated results, the transient characteristics and the overall performance of the system, not only in the traditional open cycle mode but also in closed cycle mode, are both analyzed theoretically. Furthermore, the influence of pa-rameters matching of components configuration and operation process on the cyclic characteristics of the system, such as the solar collector area, the water tank capacity and the chiller startup temperature, are discussed. The research in this work may play a very important role in optimizing the system cyclic process and improving the system adaptability especially under the condition of variable heat source.

  20. 家用电控冰箱待机功耗方案探讨%Discussion on the Stand-by Power Consumption Scheme of Household Eclectic Refrigerator

    Institute of Scientific and Technical Information of China (English)

    侯丽丽

    2015-01-01

    本文针对目前市场上最常见的两种电控冰箱定频冰箱和变频冰箱,根据其不同的负载和运行特点,在电源管理上给出了不同的降低待机功耗的解决方案.%Aiming at the common types of electric refrigerators in the market, that is, refrigerator with constant-fre-quency and refrigerator with inverter; and according to their different characteristics of load and operation, the solutions of lowering the stand-by power consumption are presented respectively from the perspective of power management.

  1. Solar-powered cooling systems: Technical and economic analysis on industrial refrigeration and air-conditioning applications

    Energy Technology Data Exchange (ETDEWEB)

    Desideri, Umberto; Proietti, Stefania; Sdringola, Paolo [Department of Industrial Engineering, University of Perugia, Via G. Duranti 67 - 06125 Perugia (Italy)

    2009-09-15

    In the last years, the growing demand for air conditioning has caused a significant increase in demand for primary energy resources. Solar-powered cooling is one of the technologies which allows to obtain, by using the renewable solar source, an important energy saving compared to traditional air conditioning plants. The paper describes different technical installations for solar cooling, their way of operation, advantages and limits. The objective of the present study has been to analyze the technical and economic feasibility of solar absorption cooling systems, designed for two different application fields: industrial refrigeration and air conditioning. The possibility to replace or integrate the existing plants is studied, by considering the refrigeration requirements of a company, which works in meat manufacturing, and the heating and cooling demands of a hotel located in a tourist town in Italy. In the first case, the system comprises an absorption chiller coupled to solar flat plate collectors, whereas the second application is about a hybrid trigeneration plant, known as thermo-solar trigeneration; this option allows having greater operational flexibility at sites with demand for energy in the form of heating as well as cooling, for example in a hotel. In this way the authors could compare different results obtained by a technical and economic experimental analysis based on existing users and evaluate the advantages and disadvantages in order to suggest the best solution for the two studied cases. (author)

  2. Computer Based Thermodynamic Properties of Ammonia-Water Mixture for the Analysis of Power and Refrigeration Cycles

    Directory of Open Access Journals (Sweden)

    Kausik Sadhukhan

    2012-06-01

    Full Text Available The thermodynamic analysis and optimization of combined power and refrigeration cycle as well as the improved vapour absorption refrigeration system necessitate the development of computer based thermodynamic properties of ammonia-water mixture. In this work, a computer code has been developed for the thermodynamic properties of ammonia water mixture for different pressures, temperatures and ammonia mass fraction concentration. This has been achieved by using some exact thermodynamic relations and some co-relations available in the literature. The computed results have been compared with the published experimental data and the agreement is found to be of good accuracy. The errors in the computed results for different thermodynamic properties are slightly more at comparatively high pressure and temperature. The maximum error is found to be with saturated liquid mixture entropy and its value is also less then 3.8% even at a high pressure of 34.47 bar.

  3. Exergy analysis of gas turbine trigeneration system for combined production of power heat and refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Khaliq, Abdul [Department of Mechanical Engineering, Faculty of Engineering and Technology, Jamia Millia Islamia, New Delhi 110025 (India)

    2009-05-15

    A conceptual trigeneration system is proposed based on the conventional gas turbine cycle for the high temperature heat addition while adopting the heat recovery steam generator for process heat and vapor absorption refrigeration for the cold production. Combined first and second law approach is applied and computational analysis is performed to investigate the effects of overall pressure ratio, turbine inlet temperature, pressure drop in combustor and heat recovery steam generator, and evaporator temperature on the exergy destruction in each component, first law efficiency, electrical to thermal energy ratio, and second law efficiency of the system. Thermodynamic analysis indicates that exergy destruction in combustion chamber and HRSG is significantly affected by the pressure ratio and turbine inlet temperature, and not at all affected by pressure drop and evaporator temperature. The process heat pressure and evaporator temperature causes significant exergy destruction in various components of vapor absorption refrigeration cycle and HRSG. It also indicates that maximum exergy is destroyed during the combustion and steam generation process; which represents over 80% of the total exergy destruction in the overall system. The first law efficiency, electrical to thermal energy ratio and second law efficiency of the trigeneration, cogeneration, and gas turbine cycle significantly varies with the change in overall pressure ratio and turbine inlet temperature, but the change in pressure drop, process heat pressure, and evaporator temperature shows small variations in these parameters. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems. (author)

  4. Potential application of solar powered adsorption cooling systems in the Middle East

    International Nuclear Information System (INIS)

    Highlights: • Theoretical investigation of adsorption chiller driven by solar CPC is presented. • The study is performed using the climate conditions of the Middle East region. • Two system configurations (with/without hot water buffer storage) are proposed. • Temporal history of solar CPC, sorption reactors, evaporator and condenser are predicted. • Cyclic and average daily cooling capacity, cycle COP and solar COP are studied. - Abstract: This paper presents a theoretical investigation on the performance of solar powered silica gel/water based adsorption cooling system working under climate conditions of the Middle East region. Actual solar data of Cairo and Aswan located, respectively, in the north and south of Egypt and the coastal city Jeddah on the Red Sea in Saudi Arabia are used in this study. Dynamic behavior of adsorption chillers driven by compound parabolic solar collector is presented. Two system configurations have been considered herein; (i) adsorption chiller is directly connected to the solar collectors, (ii) hot water buffer storage is installed between adsorption chiller and solar collectors. Temporal history of solar collector, sorption reactors, evaporator and condenser has been predicted. System performance in terms of cooling capacity, daily average cooling capacity, cycle COP and solar COP has been estimated. Results show that the maximum cyclic cooling capacity of the system working under Cairo and Jeddah climate conditions reaches about 14.8 kW and about 15.8 kW for Aswan climate conditions

  5. Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.; Welch, M.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and water heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.

  6. Experimental investigation of the ecological hybrid refrigeration cycle

    Science.gov (United States)

    Cyklis, Piotr; Kantor, Ryszard; Ryncarz, Tomasz; Górski, Bogusław; Duda, Roman

    2014-09-01

    The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2 compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2 compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

  7. Experimental investigation of the ecological hybrid refrigeration cycle

    Directory of Open Access Journals (Sweden)

    Cyklis Piotr

    2014-09-01

    Full Text Available The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used to cool down the CO2 compression cycle condenser. The adsorption process is powered with a low temperature renewable heat source as solar collectors or other waste heat source. The refrigeration system integrating adsorption and compression system has been designed and constructed in the Laboratory of Thermodynamics and Thermal Machine Measurements of Cracow University of Technology. The heat source for adsorption system consists of 16 tube tulbular collectors. The CO2 compression low temperature cycle is based on two parallel compressors with frequency inverter. Energy efficiency and TEWI of this hybrid system is quite promising in comparison with the compression only systems.

  8. Study of a gas-liquid ejector and its application to a solar-powered bi-ejector refrigeration system

    International Nuclear Information System (INIS)

    A new configuration of a bi-ejector refrigeration system is presented. The system incorporates two ejectors. The purpose of one is to suck refrigerant vapour from the evaporator and discharge to the condenser; the other acts as a jet pump to pump liquid refrigerant from the condenser to the generator. An analysis model for the bi-ejector refrigeration system and a one-dimensional flow model for the gas-liquid ejector were established. The performances of the gas-liquid ejector and the refrigeration cycle were studied using numerical modelling. The results show that the performances of ejectors and system depend a great deal on the refrigerants as well as on operation conditions

  9. Study on Use of Fuel-Cell Auxiliary Power Units in Refrigerator Cars Employed for Delivery to Convenience Store

    Science.gov (United States)

    Katayama, Noboru; Kamiyama, Hideyuki; Kogoshi, Sumio; Kudo, Yusuke; Fukada, Takafumi; Ogawa, Makoto

    The use of fuel-cell auxiliary power units (FC-APU) in refrigerator cars employed delivery to for convenience store delivery has been studied. The delivery pattern is assumed to be a typical pattern that includes driving between convenience stores or between a delivery center and a convenience store, unloading, driver's lunch break. The M15 driving mode, which simulates the driving condition in urban areas, is used as the driving mode in the delivery pattern. The FC-APU system includes a proton-exchange membrane fuel cell (PEFC) module, an inverter, and DC/DC converter. Bench tests of the FC-APU are performed to determine the hydrogen fuel consumption rate and the energy efficiency; these values depend on the output power of the PEFC module. The calculated relationship between the output power and fuel consumption rate of a current used system, which consists of an alternator and a secondary battery, are used to estimate the energy efficiency of the current used system. On the basis of the measurement data in this study and the results for the model proposed by Brodric et al. [C. J. Brodrick et al., Trans. Res. D, vol 7, pp. 303 (2002)], the payback period is calculated. The results indicate that the payback period would be 2.1 years when the FC-APU operates at a load of 70%.

  10. Experiment Study and Application Analysis of Adsorption Refrigeration 0 f Solar Cooling Tube%新型太阳能冷管吸附制冷的实验研究

    Institute of Scientific and Technical Information of China (English)

    王彦禹; 倪诚明

    2015-01-01

    根据固体吸附式制冷原理,利用太阳光作为热源,对一种新型太阳能冷管的制冷性能进行试验研究。该冷管冷凝器采用薄壁不锈钢材料,利用沸石分子筛—水作为吸附工质对。实验结果表明:在太阳辐射强度为21.01~22.90MJ/m2,室外环境温度最高为31℃时,该太阳能冷管的单支制冷量大约为145kJ,制冷温度为11℃,制冷系数约为0.118。%According to the principle of the solid adsorption refrigeration, a new type of solar cooling tube, which used the sun light as a heat source and zeolite molecular sieve/water as working pair, was made and studied in this research.The condenser was made of thin-wall stainless steel materials.The experiment results showed that: When the solar radiation intensity was between 21.01-22.90MJ/m2 and the highest environment temperature was 31℃, refrigeration capacity of the single cooling tube was 145kJ.Besides its condensation temperature was about 11℃and the refrigeration coefficient was about 0.118.

  11. Solid state magnetic refrigerator

    International Nuclear Information System (INIS)

    Highlights: ► One proposes a magnetic refrigerator not requiring the use of fluids. ► Materials whose thermal conductivities depend on an applied magnetic field are used. ► Numerical simulations show that the coefficient of performance attained reaches 1.5. ► The device can be triggered from cooler to heat source by varying the frequency. - Abstract: The viability and operation of a fully solid state magnetic refrigeration system with envisaged applications on chip, sensor and device cooling is here tested using numerical simulations. The proposed system relies on the combined use of materials displaying the magnetocaloric effect and of materials whose thermal conductivities are controlled by an external magnetic field. This allows the switching of the heat flow direction in sync with the temperature variation of the magnetocaloric material, removing the necessity to use fluids which has for long hindered the implementation of magnetic refrigeration. We have found the optimum operating conditions of the proposed refrigerator, for which a cooling power density of ∼2.75 W cm−2 was obtained for an operating temperature of ∼296 K, using Gadolinium as the magnetocaloric material and an applied magnetic field of 1 T. The coefficient of performance (COP) achieved by this refrigerator was found to be COP ∼1.5, making it a viable alternative to thermoelectric refrigeration.

  12. Performance Analysis of Waste Heat Driven Pressurized Adsorption Chiller

    KAUST Repository

    LOH, Wai Soong

    2010-01-01

    This article presents the transient modeling and performance of waste heat driven pressurized adsorption chillers for refrigeration at subzero applications. This innovative adsorption chiller employs pitch-based activated carbon of type Maxsorb III (adsorbent) with refrigerant R134a as the adsorbent-adsorbate pair. It consists of an evaporator, a condenser and two adsorber/desorber beds, and it utilizes a low-grade heat source to power the batch-operated cycle. The ranges of heat source temperatures are between 55 to 90°C whilst the cooling water temperature needed to reject heat is at 30°C. A parametric analysis is presented in the study where the effects of inlet temperature, adsorption/desorption cycle time and switching time on the system performance are reported in terms of cooling capacity and coefficient of performance. © 2010 by JSME.

  13. Application of a compact sorption generator to solar refrigeration: Case study of Dakar (Senegal)

    International Nuclear Information System (INIS)

    The feasibility of applying a low cost plate heat exchanger solid sorption reactor to solar powered refrigeration is investigated by using a validated reactor model. The proposed system is targeted at ice-making in developing countries for food preservation. The adsorption refrigeration machine modelled employs the active carbon-ammonia working pair in both two-bed and four-bed regenerative systems. Driving heat is provided from standard flat plate and evacuated tube solar collectors. The capital cost of a one-off machine with four regenerative beds which could produce up to 1000 kg of ice per day in Dakar (Senegal) is estimated at Euro 68,000.

  14. A class of internally irreversible refrigeration cycles

    Science.gov (United States)

    Ait-Ali, Mohand A.

    1996-03-01

    A Carnot-like irreversible refrigeration cycle is modelled with two isothermal and two non-adiabatic, irreversible processes. The generic source of internal irreversibility, measured by the Clausius inequality, is a general irreversibility term which could include any heat leaks into the Joule - Thompson expansion valve, the evaporator and compressor cold boxes. This cycle is optimized first for maximum refrigeration power and maximum refrigeration load, then for maximum coefficient of performance. Its performances are compared with those of the endoreversible refrigeration cycle, based on a propane stage of a classical cascade liquefaction cycle example. Both cycle models achieve optimum power and maximum refrigeration load at nearly the same refrigeration temperature, but only the coefficient of performance of the irreversible refrigeration cycle reaches a maximum. Moreover, its prediction of heat conductance allocation between evaporator and condenser appears to be not only more conservative, but also more realistic for actual design considerations of refrigeration cycles.

  15. 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.

  16. Energy Efficient Refrigeration and Flexible Power Consumption in a Smart Grid

    DEFF Research Database (Denmark)

    Hovgaard, Tobias Gybel; Halvgaard, Rasmus; Larsen, Lars F.S.;

    2011-01-01

    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...

  17. Recent Refrigeration Cycle Technologies for Household Refrigerators

    Science.gov (United States)

    Nagatomo, Shigemi

    The household refrigerator is one of the most important and the biggest energy-consuming home appliances. This paper summarize recent refrigeration cycle developments in the field of domestic household refrigerators based on a survey of publications.

  18. Helium-3 refrigerator employing capillary confinement of liquid cryogen

    Energy Technology Data Exchange (ETDEWEB)

    Ennis, D.J.; Kittel, P.; Brooks, W.; Miller, A.; Spivak, A.L.

    1983-12-01

    A condensation refrigerator suitable for operation in a zero gravity space environment was constructed. The condensed liquid refrigerant is confined by surface tension inside a porous metal matrix. Helium-4 and helium-3 gases were condensed and held in a copper matrix. Evaporative cooling of confined liquid helium-4 resulted in a temperature of 1.4K. Using a zeolite adsorption pump external to the cryostat, a temperature of 0.6 K was achieved through evaporative cooling of liquid helium-3. The amount of time required for complete evaporation of a controlled mass of liquid helium-4 contained in the copper matrix was measured as a function of the applied background power. For heating powers below 18 mW the measured times are consistent with the normal boiling of the confined volume of liquid refrigerant. At background powers above 18 mW the rapid rise in the temperature of the copper matrix the signature of the absence of confined liquid occurs in a time a factor of two shorter than that expected on the basis of an extrapolation of the low power data.

  19. Normalized Thermodynamic Model for Intermittent Energy Systems and Application to Solar-Powered Adsorption Cooling Systems

    Directory of Open Access Journals (Sweden)

    Bilgin Kaftanoglu

    2011-07-01

    Full Text Available

    A new normalized model is developed to quantify and explore trends in coincidence of supply and demand in generic intermittent energy systems as key design and operating parameters are varied. This novel model is applied to seasonal-transient simulations for a solar-thermal powered adsorption system with and without heat recovery to investigate the coincidence between the solar-supplied cooling power and cooling load in terms of seasonal solar and loss fractions. Additionally, the system's basic performance trends are investigated as a number of parameters are varied. Results for the conditions explored include the following. The solar fraction increases and the loss fraction decreases with increases in storage capacity, and both fractions decrease with increases in maximum bed temperature. The required evacuated tube collector area is smaller than the flat plate collector area while the required mass of adsorbent is independent of collector and adsorption cycle types. Simulation results also show the effects of operating conditions and several design parameters on the system's COP.


  20. Modeling and simulation of a solar powered two bed adsorption air conditioning system

    International Nuclear Information System (INIS)

    A simple lumped parameter model is established to investigate the performance of a solar powered adsorption air conditioning system driven by flat-type solar collectors with three different configurations of glazes: (i) single glazed cover; (ii) double glazed cover and (iii) transparent insulation material (TIM) cover. The dynamic performance of a continuous adsorption cycle using a double adsorber along with heat recovery is measured in terms of the temperature histories, gross solar coefficient of performance and specific cooling power. Also, the influences of some important design and operational parameters on the performance of the system are studied. It is found that the chosen three types of collector configurations make no big difference on the performance, but the adsorbent mass and lumped capacitance have significant effects on the system performance as well as on the system size. Simulation results indicate that the effect of overall heat transfer coefficient is not predominant if the cycle duration is longer. Also, there exists an optimum time to initiate the heating of the adsorbent bed in a day's operation

  1. Refrigeration Showcases

    Science.gov (United States)

    1997-01-01

    Through the Technology Affiliates Program at the Jet Propulsion Laboratory (JPL), valuable modifications were made to refrigerator displays built by Displaymor Manufacturing Company, Inc. By working with JPL, Displaymor could address stiffer requirements that ensure the freshness of foods. The application of the space technology meant that the small business would be able to continue to market its cases without incurring expenses that could threaten the viability of the business, and the future of several dozen jobs. Research and development improvements in air flow distribution and refrigeration coil technology contributed greatly to certifying Displaymor's showcases given the new federal regulations. These modifications resulted in a refrigerator case that will keep foods cooler, longer. Such changes maintained the openness of the display, critical to customer visibility and accessibility, impulse buying, and cross-merchandising.

  2. Thermodynamic and heat transfer analyses for R1234yf and R1234ze(E) as drop-in replacements for R134a in a small power refrigerating system

    International Nuclear Information System (INIS)

    In this paper we present two different analyses of R1234yf and R1234ze(E) as drop-in replacements for R134a in a small power refrigeration system. The first analysis is based on equal evaporation and condensation temperatures before and after the refrigerant replacement. The second analysis is carried out for equal cooling medium conditions in the condenser, so that the transport properties and the heat transfer features in the condenser are considered for the three refrigerants. In order to perform the analyses, a simulation model was developed, that takes into account specific data, characteristics and dimensions of the main components of a small power refrigeration system. The model was validated with experimental data for R134a and later used to predict the behavior with R1234yf and R1234ze(E). Results show that different conclusions may be drawn if the drop-in analysis is carried out for equal condensation temperatures or for equal temperatures of the cooling medium in the condenser, as well as that these results are affected by the condenser design. In general, R1234yf seems as an adequate drop-in refrigerant for R134a, but R1234ze(E) may perform better when an overridden compressor can be used to match the refrigerating system cooling power. - Highlights: • Low GWP refrigerants R1234yf and R1234ze(E) are potential replacements for R134a. • Refrigerating system mathematical model to predict drop-in performance. • Drop-in analysis for the same evaporation and condensation temperatures. • Drop-in analysis for the same cooling medium temperatures. • Refrigerant heat transfer features have a great impact on the drop-in performance

  3. Magnetocaloric effect and refrigeration cooling power in amorphous Gd7Ru3 alloys

    Directory of Open Access Journals (Sweden)

    Pramod Kumar

    2015-07-01

    Full Text Available In this paper, we report the magnetic, heat capacity and magneto-caloric effect (MCE of amorphous Gd7Ru3 compound. Both, temperature dependent magnetization and heat capacity data reveals that two transitions at 58 K and 34 K. MCE has been calculated in terms of isothermal entropy change (ΔSM and adiabatic temperature change (ΔTad using the heat capacity data in different fields. The maximum values of ΔSM and ΔTad are 21 Jmol−1K−1 and 5 K respectively, for field change of 50 kOe whereas relative cooling power (RCP is ∼735 J/kg for the same field change.

  4. Analysis of a combined power and refrigeration cycle by the exergy method

    International Nuclear Information System (INIS)

    The exergy analysis method was applied in order to evaluate the new combined cycle proposed by Goswami [Solar thermal technology: present status and ideas for the future. Energy Sources 1998;20:137-45], using Hasan-Goswami-Vijayaraghavan parameters. This new combined cycle was proposed to produce both power and cooling simultaneously with only one heat source and using ammonia-water mixture as the working fluid. The simulation of the cycle was carried out in the process simulator ASPEN Plus. The Redlich-Kwong-Soave equation of state was used to calculate the thermodynamic properties. The cycle was simulated as a reversible as well as an irreversible process to clearly show the effect of the irreversibilities in each component of the cycle. At the irreversible process two cases were considered, changing the environmental temperature. However, in order to know the performance of the new cycle at different conditions of operation, the second irreversible case was analyzed varying the rectification temperatures, the isentropic efficiency of the turbine and the return temperature of the chilled water. Exergy effectiveness values of ∼53% and ∼51% were obtained for the irreversible cycles; with heat input requirements at temperatures of 125 and 150 deg. C. Solar collectors or waste heat are suggested as heat sources to operate the cycle

  5. 固体吸附式空调/热泵在火电厂中的应用研究%STUDY ON APPLYING SOLID-ADSORPTION AIR CONDITIONING / HEAT PUMP IN THERMAL POWER PLANT

    Institute of Scientific and Technical Information of China (English)

    李中华; 王如竹; 刘建军; 柳正军; 刘洪文

    2001-01-01

    采用新型固体吸附式制冷技术开发了电站锅炉排污热回收系统。该系统可直接回收排污热进行空调制冷,并对电厂热力系统进行热泵供热,不但节约大量空调用电,而且提高了机组热经济性,具有显著的节能效果。%A heat recovery system of discharged waste water from boilers in thermal power plant was developed. The recovered heat can be used to drive solid-adsorption refrigerator for air conditioning and supply heat to heat-pump for thermal system, reducing greatly the electricity consumption of air conditioning, improving thermal efficiency of generating units, resulting in obvious energy-saving effect.

  6. Brownian refrigerator.

    Science.gov (United States)

    Van den Broeck, C; Kawai, R

    2006-06-01

    Onsager symmetry implies that a Brownian motor, driven by a temperature gradient, will also perform a refrigerator function upon loading. We analytically calculate the corresponding heat flow for an exactly solvable microscopic model and compare it with molecular dynamics simulations. PMID:16803223

  7. Supercooling Refrigerator

    Science.gov (United States)

    1986-01-01

    A Goddard/Philips research project resulted in a refrigeration system which works without seals, lubricants or bearings. The system, originally developed to cool satellite-based scientific instruments, has an extensive range of potential spinoffs. It is called the Stirling Cycle Cryogenic Cooler and eliminates friction by using electronically controlled linear magnetic bearings. Mechanical failure, contamination are eliminated.

  8. Optimal refrigerator

    OpenAIRE

    Allahverdyan, Armen E.; Hovhannisyan, Karen; Mahler, Guenter

    2010-01-01

    We study a refrigerator model which consists of two $n$-level systems interacting via a pulsed external field. Each system couples to its own thermal bath at temperatures $T_h$ and $T_c$, respectively ($\\theta\\equiv T_c/T_h

  9. Refrigeration Servicing.

    Science.gov (United States)

    Hamilton, Donald L.; And Others

    This self-study course is designed to familiarize Marine enlisted personnel with the services required to be performed on refrigeration equipment. The course contains four study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work…

  10. Dynamic considerations for composite metal-rubber laminate acoustic power coupling bellows with application to thermoacoustic refrigeration

    Science.gov (United States)

    Smith, Robert William

    Many electrically driven thermoacoustic refrigerators have employed corrugated metal bellows to couple work from an electro-mechanical transducer to the working fluid typically. An alternative bellows structure to mediate this power transfer is proposed: a laminated hollow cylinder comprised of alternating layers of rubber and metal 'hoop-stack'. Fatigue and visoelastic power dissipation in the rubber are critical considerations; strain energy density plays a role in both. Optimal aspect ratios for a rectangle corss-section in the rubber, for given values of bellows axial strain and oscillatory pressure loads are discussed. Comparisons of tearing energies estimated from known load cases and those obtained by finite element analysis for candidate dimensions are presented. The metal layers of bellows are subject to an out-of-plane buckling instability for the case of external pressure loading; failure of this type was experimentally observed. The proposed structure also exhibits column instability when subject to internal pressure, as do metal bellows. For hoop-stack bellows, shear deflection cannot be ignored and this leads to column instability for both internal and external pressures, the latter being analogous to the case of tension buckling of a beam. During prototype bellows testing, transverse modes of vibration are believed to have been excited parametrically as a consequence of the oscillatory pressures. Some operating frequencies of interest in this study lie above the cut-on frequency at which Timoshenko beam theory (TBT) predicts multiple phase speeds; it is shown that TBT fails to accurately predict both mode shapes and resonance frequencies in this regime. TBT is also shown to predict multiple phase speeds in the presence of axial tension, or external pressures, at magnitudes of interest in this study, over the entire frequency spectrum. For modes below cut-on absent a pressure differential (or equivalently, axial load) TBT predicts decreasing resonance

  11. The Modification of the Valves of a Refrigeration Piston Compressor due to the Refrigerant Change

    Directory of Open Access Journals (Sweden)

    Li Liansheng

    2003-03-01

    Full Text Available Compressor and refrigerant play key roles in a refrigeration system. Owing to the de-mands of environment protection, the CFCs and HCFCs refrigerants will be phased out in a short time, and new refrigerants such as R600, R134a and R407C will be used. As the new refrigerant is selected, the motion regularity of the valves will be changed. The motion regularity of the ring valves of a 2-stage refrigerating piston compressor is simulated, and the calculations are done respectively with refrigerants R717 (ammonia, R22 and R134a. The results show that refrigerants and working conditions of a compressor have a direct effect on the motion of the ring valves. Comparing the original design parameters of the ring valves with the modified ones, the former are effective for the HCFC refrigerants, the latter have perfect motion of the valves for the new refrigerants, and the refrigeration system performance parameters, such as input power, the refrigerating quantity and the COP value, are also better. Service life test of the compressor system using the ring valves has been done for R717. The compressor using the modified ring valves has a life exceeding 8000 hours. Hence, the valve design should consider the influences of the refrigerant.

  12. Hybrid Vapor Compression Adsorption System: Thermal Storage Using Hybrid Vapor Compression Adsorption System

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-04

    HEATS Project: UTRC is developing a new climate-control system for EVs that uses a hybrid vapor compression adsorption system with thermal energy storage. The targeted, closed system will use energy during the battery-charging step to recharge the thermal storage, and it will use minimal power to provide cooling or heating to the cabin during a drive cycle. The team will use a unique approach of absorbing a refrigerant on a metal salt, which will create a lightweight, high-energy-density refrigerant. This unique working pair can operate indefinitely as a traditional vapor compression heat pump using electrical energy, if desired. The project will deliver a hot-and-cold battery that provides comfort to the passengers using minimal power, substantially extending the driving range of EVs.

  13. Statistical fractal adsorption isotherms, linear energy relations, and power-law trapping-time distributions in porous media

    International Nuclear Information System (INIS)

    Drazer and Zanette [Phys. Rev. E 60, 5858 (1999)] have reported on interesting experiments which show that trapping-time distributions in porous media obey a scaling law of the negative power-law type. Unfortunately, their theoretical interpretation of the experimental data has physical and mathematical inconsistencies and errors. Drazer and Zanette assume the existence of a distribution of local adsorption isotherms for which the random parameter is not a thermodynamic function, but a kinetic parameter, the trapping time. Moreover, they mistakenly identify the reciprocal value of a rate coefficient with the instantaneous (fluctuating) value of the trapping time. Their approach leads to mathematically inconsistent probability densities for the trapping times, which they find to be non-normalizable. We suggest a different theory, which is physically and mathematically consistent. We start with the classical patch approximation, which assumes the existence of a distribution of adsorption heats, and introduce two linear energy relationships between the activation energies of the adsorption and desorption processes and the adsorption heat. If the distribution of the adsorption heat obeys the exponential law of Zeldovich and Roghinsky, then both the adsorption isotherm and the probability density of trapping times can be evaluated analytically in terms of the incomplete beta and gamma functions, respectively. Our probability density of the trapping times is mathematically consistent; that is, it is non-negative and normalized to unity. For large times it has a long tail which obeys a scaling law of the negative power-law type, which is consistent with the experimental data of Drazer and Zanette. By using their data we can evaluate the numerical values of the proportionality coefficients in the linear energy relations. The theory suggests that experimental study of the temperature dependence of the fractal exponents helps to elucidate the mechanism of the adsorption

  14. 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)

  15. Fluorescent refrigeration

    Science.gov (United States)

    Epstein, Richard I.; Edwards, Bradley C.; Buchwald, Melvin I.; Gosnell, Timothy R.

    1995-01-01

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

  16. Cooling with solar heat. Absorption refrigerator; Mit Sonnenwaerme kuehlen. Absorptionskaeltemaschine

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2009-04-15

    Absorption and adsorption techniques make it possible to provide cold water at a typical air conditioning level by means of solar heat. Often, absorption refrigerators using lithium bromide dissolved in water as absorption agent and water as refrigerant are used for this purpose. (orig.)

  17. Air leakage in refrigerated vans. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    The Air Leakage in Refrigerated Vans Project was initiated by the Department of Energy to assess the impact of air leakage on fuel consumption of highway transport refrigeration equipment. The project, conducted from September of 1977 to December of 1978 collected air leakage data on refrigerated trailers, containers and truck bodies. A Prototype Air Leakage Test Set was developed, designed and constructed to take measurements, and a total of 92 representative vehicles were examined. The results of the study indicate that air leakage causes a 25% increase in the average refrigeration load. However, the majority of transport refrigeration units are equipped with control systems that require the power to be supplied continuously, so that the potential reduction in fuel consumption that can be expected by reduced air leakage is limited. Alternative control techniques and power sources for the control and operation of refrigeration unit components other than the compressor could reduce fuel consumption by approximately 60%.

  18. Study on Jet-Compression Hybrid Refrigeration Cycle Driven by Heat and Power%热-电驱动喷射压缩复合制冷循环特性研究

    Institute of Scientific and Technical Information of China (English)

    王林; 谈莹莹; 梁坤峰; 安方涛; 陈宁

    2014-01-01

    Autocascade refrigeration can achieve lower refrigeration temperature easily,but it totally consumes high grade energy and its COP is low.Jet refrigeration can achieve the refrigeration effect by utilizing low grade heat sources.However,its refrigeration temperature is high.In order to utilize low grade heat to the domain of cryogenic freezing,jet/compression hybrid refrigeration cycle with mixed refrigerants driven by low grade heat and power was presented.The new cycle contributes to improving the efficiency of refrigeration significantly and achieving lower refrigeration temperature.On a basis of its mathematical model,the influences of compression ratio of the ejector and compressor on mechanical and thermal coefficient of performance(COPme/COPth) were analyzed.The results indicate that refrigeration efficiency of the hybrid refrigeration cycle is much higher than that of the traditional autocascade refrigeration cycle.%自复叠制冷循环具有获得制冷温度低优点,但其完全消耗的是高品位电能或机械能;喷射制冷具有利用低品位低温热源(60~100℃)制取冷量、且制冷温度较高时制冷效率高等优点,但难以获得较低制冷温度.因此,为了实现低品位热在低温冷冻领域高效利用并节省高品位电能,本文提出一种由低品位低温热源与电能联合驱动的混合工质喷射/压缩复合制冷循环.建立组成新循环各部件热力学数学模型,分析喷射器压缩比和压缩机压缩比对复合式制冷循环的热性能系数和机械性能系数影响,并与传统的自复叠制冷循环特性进行比较分析.研究表明,低品位热源与电能联合驱动喷射/压缩复合制冷循环较传统自复叠制冷循环可显著提高制冷效率并获得更低制冷温度.

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

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

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

  20. Candidate chemical systems for air cooled, solar powered, absorption air conditioner design. Part II. Solid absorbents, high latent heat refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Biermann, W. J.

    1978-04-01

    Work done in attempting to qualify absorption refrigeration systems based on refrigerants with intermediate latent heats of vaporization is summarized. In practice, these comprise methanol, ammonia, and methylamine. A wide variety of organic substances, salts, and mixtures were evaluated in as systematic a manner as possible. Several systems of interest are described. The system, LiClO/sub 3/--LiBr--H/sub 2/O, is a good back up system to our first choice of an antifreeze additive system, and thermodynamically promising but subject to some inconvenient materials limitations. The system, LiBr/ZnBr/sub 2/--methanol, is thermodynamically promising but requires additional kinetic qualification. Chemical stability of the system, LiCNS--ammonia/methylamine with various other third components, does not appear to be adequate for a long-lived system.

  1. Refrigeration and Food Safety

    Science.gov (United States)

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

  2. Simulation of an adsorption solar cooling system

    International Nuclear Information System (INIS)

    A more realistic theoretical simulation model for a tubular solar adsorption refrigerating system using activated carbon-methanol (AC/M) pair has been introduced. The mathematical model represents the heat and mass transfer inside the adsorption bed, the condenser, and the evaporator. The simulation technique takes into account the variations of ambient temperature and solar radiation along the day. Furthermore, the local pressure, and local thermal conductivity variations in space and time inside the tubular reactor are investigated as well. A C++ computer program is written to solve the proposed numerical model using the finite difference method. The developed program covers the operations of all the system components along the cycle time. The performance of the tubular reactor, the condenser, and the evaporator has been discussed. Time allocation chart and switching operations for the solar refrigeration system processes are illustrated as well. The case studied has a 1 m2 surface area solar flat plate collector integrated with a 20 stainless steel tubes containing the AC/M pair and each tube has a 5 cm outer diameter. In addition, the condenser pressure is set to 54.2 kpa. It has been found that, the solar coefficient of performance and the specific cooling power of the system are 0.211 and 2.326 respectively. In addition, the pressure distribution inside the adsorption bed has been found nearly uniform and varying only with time. Furthermore, the AC/M thermal conductivity is shown to be constant in both space and time.

  3. The Quantum Absorption Refrigerator

    CERN Document Server

    Levy, Amikam

    2011-01-01

    A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified, the cooling power Jc vanishes as Jc proportional to Tc^{alpha}, when Tc approaches the absolute zero, where alpha = 2 for a bath with flat spectral density and alpha = 3 for an Ohmic spectral density.

  4. Performance Evaluation of a Continuous Operation Adsorption Chiller Powered by Solar Energy Using Silica Gel and Water as the Working Pair

    OpenAIRE

    Hassan Zohair Hassan

    2014-01-01

    In the present study, dynamic analysis and performance evaluation of a solar-powered continuous operation adsorption chiller are introduced. The adsorption chiller uses silica gel and water as the working pair. The developed mathematical model represents the heat and mass transfer within the reactor coupled with the energy balance of the collector plate and the glass cover. Moreover, a non-equilibrium adsorption kinetic model is taken into account by using the linear driving force equation. T...

  5. Analysis of Combined Power and Refrigeration Generation Using the Carbon Dioxide Thermodynamic Cycle to Recover the Waste Heat of an Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Shunsen Wang

    2014-01-01

    Full Text Available A novel thermodynamic system is proposed to recover the waste heat of an internal combustion engine (ICE by integrating the transcritical carbon dioxide (CO2 refrigeration cycle with the supercritical CO2 power cycle, and eight kinds of integration schemes are developed. The key parameters of the system are optimized through a genetic algorithm to achieve optimum matching with different variables and schemes, as well as the maximum net power output (Wnet. The results indicate that replacing a single-turbine scheme with a double-turbine scheme can significantly enhance the net power output (Wnet and lower the inlet pressure of the power turbine (P4. With the same exhaust parameters of ICE, the maximum Wnet of the double-turbines scheme is 40%–50% higher than that of the single-turbine scheme. Replacing a single-stage compression scheme with a double-stage compression scheme can also lower the value of P4, while it could not always significantly enhance the value of Wnet. Except for the power consumption of air conditioning, the net power output of this thermodynamic system can reach up to 13%–35% of the engine power when it is used to recover the exhaust heat of internal combustion engines.

  6. Magnon-driven quantum dot refrigerators

    Science.gov (United States)

    Wang, Yuan; Huang, Chuankun; Liao, Tianjun; Chen, Jincan

    2015-12-01

    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.

  7. Rotary magnetic refrigerator for superfluid helium production

    International Nuclear Information System (INIS)

    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%

  8. A rotating magnetic refrigerator for helium liquefaction

    International Nuclear Information System (INIS)

    This paper presents the first experimental result of a new rotating magnetic refrigerator which uses gadolinium-gallium-garnet (GGG) single crystal as the magnetic material. The refrigerator mainly consists of a rotating disc with 8 pieces of GGG (20 mm in diameter and 10 mm in length), superconducting DC magnets, a heat absorber, a liquid helium reservoir, and a driving motor. The refrigerator operates the reversed Carnot cycle, and a 0.1 W refrigeration power in the 2.87 rpm operation has been achieved under 4.2 K to 8.2 K operation

  9. REACH. Refrigeration Units.

    Science.gov (United States)

    Snow, Rufus; And Others

    As a part of the REACH (Refrigeration, Electro-Mechanical, Air-Conditioning, Heating) electromechanical cluster, this student manual contains individualized instructional units in the area of refrigeration. The instructional units focus on refrigeration fundamentals, tubing and pipe, refrigerants, troubleshooting, window air conditioning, and…

  10. Stirling Refrigerator

    Science.gov (United States)

    Kagawa, Noboru

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

  11. 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.

  12. Alternative Refrigerants: A Review

    OpenAIRE

    S.K. Kalla*; , J.A. Usmani

    2014-01-01

    During the last decade, substantial research activities have been undertaken regarding refrigeration cycles and systems with particular emphasis on the replacement of refrigerants like R134a by refrigerants like hydrocarbons which have negligible GWP (Global Warming Potential).Besides using eco-friendly refrigerants, thrust has been given upon devising methods to increase the efficiency of the refrigeration cycle/system, which will also contribute to reducing emission of GHG(G...

  13. 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.

  14. 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.

  15. 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.

  16. Research and Development of a Small-Scale Adsorption Cooling System

    Science.gov (United States)

    Gupta, Yeshpal

    The world is grappling with two serious issues related to energy and climate change. The use of solar energy is receiving much attention due to its potential as one of the solutions. Air conditioning is particularly attractive as a solar energy application because of the near coincidence of peak cooling loads with the available solar power. Recently, researchers have started serious discussions of using adsorptive processes for refrigeration and heat pumps. There is some success for the >100 ton adsorption systems but none exists in the solar-powered heat pump systems, an hourly building load simulation was developed for a single-family house in the Phoenix metropolitan area. Thermal as well as economic performance comparison was conducted for adsorption, absorption, and solar photovoltaic (PV) powered vapor compression systems for a range of solar collector area and storage capacity. The results showed that for a small collector area, solar PV is more cost-effective whereas adsorption is better than absorption for larger collector area. The optimum solar collector area and the storage size were determined for each type of solar system. As part of this dissertation work, a small-scale proof-of-concept prototype of the adsorption system was assembled using some novel heat transfer enhancement strategies. Activated carbon and butane was chosen as the adsorbent-refrigerant pair. It was found that a COP of 0.12 and a cooling capacity of 89.6 W can be achieved.

  17. Swiss energy research program on heat-pumps, combined heat and power and refrigeration for 2008-2011; Energieforschungsprogramm. Waermepumpen, Waerme-Kraft-Kopplung, Kaelte fuer die Jahre 2008-2011

    Energy Technology Data Exchange (ETDEWEB)

    Kopp, T. [Hochschule fuer Technik HSR, Rapperswil (Switzerland); Eckmanns, A. [Swiss Federal Office of Energy (OFEN), Berne (Switzerland)

    2009-07-15

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at the research programme on heat-pumps, combined heat and power and refrigeration for the years 2008 - 2011. Work proposed for the years 2008 - 2011 involves the following topics: Improvement of components and the thermodynamic cycles of heat pumps and refrigeration plants as well as the improvements in the efficiency of cogeneration plants and the reduction of emission of pollutants. Also, the overall optimisation of total systems is to be examined. Highly-efficient systems for sanitary hot water production are to be looked at, as are miniaturisation and new solutions for the installation of heating and cooling systems with heat pumps. Also the development of environmental-friendly working fluids for heat pumps and refrigeration plants is planned. Pilot and demonstration projects are also to be supported in all areas.

  18. Re-engineering of refrigeration system of Heavy Water Plant Tuticorin

    International Nuclear Information System (INIS)

    Refrigeration system - a typical vapour compression system - normally an energy intensive process provides a good scope for energy conservation. After a detailed study of our refrigeration system, we have re-engineered our entire refrigeration system which has resulted in a tremendous power saving of 10300 units per day. This paper deals with the modifications implemented in HWP, Tuticorin in the refrigeration network. (author)

  19. Experimental investigation on activated carbon-ethanol pair for solar powered adsorption cooling applications

    Energy Technology Data Exchange (ETDEWEB)

    El-Sharkawy, I.I. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580 (Japan); Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, El-Mansoura (Egypt); Saha, B.B.; Koyama, S. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-koen 6-1, Kasuga-shi, Fukuoka 816-8580 (Japan); He, J.; Ng, K.C.; Yap, C. [Department of Mechanical Engineering, National University of Singapore, 10 Kent Ridge Crescent (Singapore)

    2008-12-15

    Adsorption equilibrium uptake of ethanol onto a highly porous activated carbon based adsorbent, namely Maxsorb III, has been experimentally investigated using a thermo-gravimetric analyzer (TGA) unit over adsorption temperatures ranging from 20 to 60 C. The Dubinin-Astakhov (D-A) equation has been used to correlate the experimental data. Isosteric heat of adsorption is also estimated by using the Clausius-Clapeyron equation. Employing a thermodynamically equilibrium model, the performance of the ideal adsorption cooling cycle has also been studied and compared to that of activated carbon fiber (ACF)-ethanol pair. Experimental results show that Maxsorb III can adsorb up to 1.2 kg of ethanol per kilogram of adsorbent. Theoretical calculations show that, the Maxsorb III-ethanol adsorption cycle can achieve a specific cooling effect of about 420 kJ kg{sup -1} at an evaporator temperature of 7 C along with a heat source of temperature 80 C and thus the pair is recommended for solar cooling applications. (author)

  20. The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

    Energy Technology Data Exchange (ETDEWEB)

    Romero Paredes, H.; Ambriz, J.J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

    1995-12-31

    Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

  1. Permanent magnet array for the magnetic refrigerator

    Science.gov (United States)

    Lee, S. J.; Kenkel, J. M.; Pecharsky, V. K.; Jiles, D. C.

    2002-05-01

    Recent research into the development of magnetic refrigeration (MR) operating at room temperature has shown that it can provide a reliable, energy-efficient cooling system. To enhance the cooling power of the magnetic refrigerator, it is required to use a magnetic refrigerant material with large magnetocaloric effect (MCE) at the appropriate temperature. Most advanced magnetic refrigerant materials show largest MCE at high applied magnetic fields generated by a superconducting magnet. For application of MCE to air conditioners or household refrigerators, it is essential to develop a permanent magnet array to form a compact, strong, and energy-efficient magnetic field generator. Generating a magnetic field well above the remanence of a permanent magnet material is hard to achieve through conventional designs. A permanent magnet array based on a hollow cylindrical flux source is found to provide an appropriate geometry and magnetic field strength for MR applications.

  2. 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.

  3. Removal of Radionuclides from Waste Water at Fukushima Daiichi Nuclear Power Plant: Desalination and Adsorption Methods - 13126

    Energy Technology Data Exchange (ETDEWEB)

    Kani, Yuko; Kamosida, Mamoru; Watanabe, Daisuke [Hitachi Research Laboratory, Hitachi, Ltd., 7-2-1 Omika-cho, Hitachi, Ibaraki, 319-1221 (Japan); Asano, Takashi; Tamata, Shin [Hitachi Works, Hitachi-GE Nuclear Energy, Ltd. (Japan)

    2013-07-01

    Waste water containing high levels of radionuclides due to the Fukushima Daiichi Nuclear Power Plant accident, has been treated by the adsorption removal and reverse-osmosis (RO) desalination to allow water re-use for cooling the reactors. Radionuclides in the waste water are collected in the adsorbent medium and the RO concentrate (RO brine) in the water treatment system currently operated at the Fukushima Daiichi site. In this paper, we have studied the behavior of radionuclides in the presently applied RO desalination system and the removal of radionuclides in possible additional adsorption systems for the Fukushima Daiichi waste water treatment. Regarding the RO desalination system, decontamination factors (DFs) of the elements present in the waste water were obtained by lab-scale testing using an RO unit and simulated waste water with non-radioactive elements. The results of the lab-scale testing using representative elements showed that the DF for each element depended on its hydrated ionic radius: the larger the hydrated ionic radius of the element, the higher its DF is. Thus, the DF of each element in the waste water could be estimated based on its hydrated ionic radius. For the adsorption system to remove radionuclides more effectively, we studied adsorption behavior of typical elements, such as radioactive cesium and strontium, by various kinds of adsorbents using batch and column testing. We used batch testing to measure distribution coefficients (K{sub d}s) for cesium and strontium onto adsorbents under different brine concentrations that simulated waste water conditions at the Fukushima Daiichi site. For cesium adsorbents, K{sub d}s with different dependency on the brine concentration were observed based on the mechanism of cesium adsorption. As for strontium, K{sub d}s decreased as the brine concentration increased for any adsorbents which adsorbed strontium by intercalation and by ion exchange. The adsorbent titanium oxide had higher K{sub d}s and it

  4. Removal of Radionuclides from Waste Water at Fukushima Daiichi Nuclear Power Plant: Desalination and Adsorption Methods - 13126

    International Nuclear Information System (INIS)

    Waste water containing high levels of radionuclides due to the Fukushima Daiichi Nuclear Power Plant accident, has been treated by the adsorption removal and reverse-osmosis (RO) desalination to allow water re-use for cooling the reactors. Radionuclides in the waste water are collected in the adsorbent medium and the RO concentrate (RO brine) in the water treatment system currently operated at the Fukushima Daiichi site. In this paper, we have studied the behavior of radionuclides in the presently applied RO desalination system and the removal of radionuclides in possible additional adsorption systems for the Fukushima Daiichi waste water treatment. Regarding the RO desalination system, decontamination factors (DFs) of the elements present in the waste water were obtained by lab-scale testing using an RO unit and simulated waste water with non-radioactive elements. The results of the lab-scale testing using representative elements showed that the DF for each element depended on its hydrated ionic radius: the larger the hydrated ionic radius of the element, the higher its DF is. Thus, the DF of each element in the waste water could be estimated based on its hydrated ionic radius. For the adsorption system to remove radionuclides more effectively, we studied adsorption behavior of typical elements, such as radioactive cesium and strontium, by various kinds of adsorbents using batch and column testing. We used batch testing to measure distribution coefficients (Kds) for cesium and strontium onto adsorbents under different brine concentrations that simulated waste water conditions at the Fukushima Daiichi site. For cesium adsorbents, Kds with different dependency on the brine concentration were observed based on the mechanism of cesium adsorption. As for strontium, Kds decreased as the brine concentration increased for any adsorbents which adsorbed strontium by intercalation and by ion exchange. The adsorbent titanium oxide had higher Kds and it was used for the column

  5. Quantum absorption refrigerator.

    Science.gov (United States)

    Levy, Amikam; Kosloff, Ronnie

    2012-02-17

    A quantum absorption refrigerator driven by noise is studied with the purpose of determining the limitations of cooling to absolute zero. The model consists of a working medium coupled simultaneously to hot, cold, and noise baths. Explicit expressions for the cooling power are obtained for Gaussian and Poisson white noise. The quantum model is consistent with the first and second laws of thermodynamics. The third law is quantified; the cooling power J(c) vanishes as J(c) ∝ T(c)(α), when T(c)→0, where α=d+1 for dissipation by emission and absorption of quanta described by a linear coupling to a thermal bosonic field, where d is the dimension of the bath. PMID:22401189

  6. Exergy based parametric analysis of a combined reheat regenerative thermal power plant and water–LiBr vapor absorption refrigeration system

    International Nuclear Information System (INIS)

    Highlights: • Exergy analysis of a combined power–absorption cooling system is provided. • Exergetic efficiency of the power cycle and absorption cooling system are calculated. • Irreversibility in each component and total system irreversibility are calculated. • Effect of operating parameters on exergetic performance and irreversibility is analyzed. • Optimum operating parameters are identified based on energy and exergy based results. - Abstract: In this paper, exergy analysis of a combined reheat regenerative steam turbine (ST) based power cycle and water–LiBr vapor absorption refrigeration system (VARS) is presented. Exergetic efficiency of the power cycle and VARS, energy utilization factor (EUF) of the combined system (CS) and irreversibility in each system component are calculated. The effect of fuel flow rate, boiler pressure, cooling capacity and VARS components’ temperature on performance, component and total system irreversibility is analyzed. The second law based results indicate optimum performance at 150 bar boiler pressure and VARS generator, condenser, evaporator and absorber temperature of 80 °C, 37.5 °C, 15 °C and 35 °C respectively. The present exergy based results conform well to the first law based results obtained in a previous analysis done on the same combined system. Irreversibility distribution among various power cycle components shows the highest irreversibility in the cooling tower. Irreversibility of the exhaust flue gas leaving the boiler and the boiler are the next major contributors. Among the VARS components, exergy destruction in the generator is the highest followed by irreversibility contribution of the absorber, condenser and the evaporator

  7. Anomalous Brownian refrigerator

    Science.gov (United States)

    Rana, Shubhashis; Pal, P. S.; Saha, Arnab; Jayannavar, A. M.

    2016-02-01

    We present a detailed study of a Brownian particle driven by Carnot-type refrigerating protocol operating between two thermal baths. Both the underdamped as well as the overdamped limits are investigated. The particle is in a harmonic potential with time-periodic strength that drives the system cyclically between the baths. Each cycle consists of two isothermal steps at different temperatures and two adiabatic steps connecting them. Besides working as a stochastic refrigerator, it is shown analytically that in the quasistatic regime the system can also act as stochastic heater, depending on the bath temperatures. Interestingly, in non-quasistatic regime, our system can even work as a stochastic heat engine for certain range of cycle time and bath temperatures. We show that the operation of this engine is not reliable. The fluctuations of stochastic efficiency/coefficient of performance (COP) dominate their mean values. Their distributions show power law tails, however the exponents are not universal. Our study reveals that microscopic machines are not the microscopic equivalent of the macroscopic machines that we come across in our daily life. We find that there is no one to one correspondence between the performance of our system under engine protocol and its reverse.

  8. Magnetic refrigeration materials

    Institute of Scientific and Technical Information of China (English)

    戴闻; 沈保根; 高政祥

    2001-01-01

    Magnetic refrigeration has drawn much attention because of its greater efficiency and higher reliability than the traditional gas-cycle refrigeration technology. Recently, a kind of new materials with a giant magnetocaloric effect in the subroom temperature range, Gd5 (Six Ge1- x)4, was discovered, which boosts the search for high-performance magnetic refrigerants. However, the intermetallic compounds Gd5 (SixGe1 - x )4 belong to the first order transition materials; their performance in practical magnetic refrigeration cycles remains controversial. In this paper the developing tendency of the refrigerants are discussed on the basis of our work.

  9. Pattern Formation and a Clustering Transition in Power-Law Sequential Adsorption

    OpenAIRE

    Biham, Ofer; Malcai, Ofer; Lidar, Daniel A.; Avnir, David

    1999-01-01

    A new model that describes adsorption and clustering of particles on a surface is introduced. A {\\it clustering} transition is found which separates between a phase of weakly correlated particle distributions and a phase of strongly correlated distributions in which the particles form localized fractal clusters. The order parameter of the transition is identified and the fractal nature of both phases is examined. The model is relevant to a large class of clustering phenomena such as aggregati...

  10. Optimized heat exchanger unit in a thermoacoustic refrigerator

    Science.gov (United States)

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

    2012-06-01

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

  11. Improvement of a thermoelectric and vapour compression hybrid refrigerator

    International Nuclear Information System (INIS)

    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.

  12. Electronic Refrigeration at the Quantum Limit

    OpenAIRE

    Timofeev, Andrey V.; Helle, Meri; Meschke, Matthias; Möttönen, Mikko; Pekola, Jukka P.

    2009-01-01

    We demonstrate quantum limited electronic refrigeration of a metallic island in a low temperature micro-circuit. We show that matching the impedance of the circuit enables refrigeration at a distance, of about 50 um in our case, through superconducting leads with a cooling power determined by the quantum of thermal conductance. In a reference sample with a mismatched circuit this effect is absent. Our results are consistent with the concept of electromagnetic heat transport. We observe and an...

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

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, VAN

    2003-05-19

    has its own refrigeration unit; low-charge direct expansion--similar to conventional multiplex refrigeration systems but with improved controls to limit charge. Means to integrate store HVAC systems for space heating/cooling with the refrigeration system have been investigated as well. One approach is to use heat pumps to recover refrigeration waste heat and raise it to a sufficient level to provide for store heating needs. Another involves use of combined heating and power (CHP) or combined cooling, heating, and power (CCHP) systems to integrate the refrigeration, HVAC, and power services in stores. Other methods including direct recovery of refrigeration reject heat for space and water heating have also been examined.

  14. Adsorption cold storage system with zeolite-water working pair used for locomotive air conditioning

    International Nuclear Information System (INIS)

    Adsorption cold storage has lately attracted attention for its large storage capacity and zero cold energy loss during the storing process. Thermodynamic and experimental studies on the cold storage capacity and the cold discharging process, in which the adsorber is either air cooled or adiabatic, have been presented. An adsorption cold storage system with zeolite-water working pair has been developed, and some operating results are summarized. This system is used for providing air conditioning for the driver's cab of an internal combustion locomotive. Unlike a normal adsorption air conditioner, the system starts running with the adsorption process, during which the cold energy stored is discharged, and ends running with the generation process. The adsorbent temperature decreases during the cold storing period between two runs. The refrigeration power output for the whole running cycle is about 4.1 kW. It appears that such a system is quite energetically efficient and is comparatively suitable for providing discontinuous refrigeration capacity when powered by low grade thermal energy, such as industrial exhausted heat or solar energy

  15. About Solar Refrigeration

    Directory of Open Access Journals (Sweden)

    Laura Coroiu

    2008-05-01

    Full Text Available This paper has the purpose to unfold the results of all researches which proved before that the solar energy constitutes itself as an ideal resource for heating application that necessitate lower temperature,e.g. the heating of a certain space or the preparation ofthe domestic hot water. The refrigeration systems, which are based on the nontoxic refrigerants for the environment, offer a sustained advantage when compared to the other types of the refrigerants. But, whichever might be the case, the use of the energy associated to the operation of the refrigeration system and with the impact that it has upon the environment, as well as the association with its production and distribution, have often a bigger importance than the selection of the refrigerant. In order to minimize the impact which the operation of the refrigeration systems exerts upon the environment, it is recommended that there should be checked all thepossibilities of using a pure source of energy.

  16. Effect of process parameters on power requirements of vacuum swing adsorption technology for CO2 capture from flue gas

    International Nuclear Information System (INIS)

    This study focuses on the effects of process and operating parameters - feed gas temperature, evacuation pressure and feed concentration - on the performance of carbon dioxide vacuum swing adsorption (CO2VSA) processes for CO2 capture from gas, especially as it affects power consumption. To obtain reliable data on the VSA process, experimental work was conducted on a purposely built three bed CO2VSA pilot plant using commercial 13X zeolite. Both 6 step and 9 step cycles were used to determine the influences of temperature, evacuation pressure and feed concentration on process performance (recovery, purity, power and corresponding capture cost). A simple economic model for CO2 capture was developed and employed herein. Through experiments and analysis, it is found that the feed gas temperature, evacuation pressure and feed concentration have significant effects on power consumption and CO2 capture cost. Our data demonstrate that the CO2VSA process has good recovery (>70%), purity (>90%) and low power cost (4-10 kW/TPDc) when operating with 40 C feed gas provided relatively deep vacuum is used. Enhanced performance is obtained when higher feed gas concentration is fed to the plant, as expected. Our data indicates large potential for application of CO2VSA to CO2 capture from flue gas. (author)

  17. Refrigerator Based on Chemisorption

    Science.gov (United States)

    Jones, Jack A.

    1987-01-01

    Reversible chemical reaction generates pressurized oxygen for cooling. Concept for cryogenic refrigerator based on chemical absorption of oxygen by praseodymium/cerium oxide (PCO) compound. Refrigerator produces cryogenic liquid for cooling infrared sensors. Also used for liquefying air and separating oxygen from nitrogen in air. In chemisorption refrigerator, PCO alternately absorbs and desorbs oxygen depending on whether cooled or heated. One pair of compressors accepts oxygen while others releases it. Compressed oxygen liquefied when precooked and expanded.

  18. About Solar Refrigeration

    OpenAIRE

    Laura Coroiu; Helga Silaghi; Adriana Grava; Pantea, M.

    2008-01-01

    This paper has the purpose to unfold the results of all researches which proved before that the solar energy constitutes itself as an ideal resource for heating application that necessitate lower temperature,e.g. the heating of a certain space or the preparation ofthe domestic hot water. The refrigeration systems, which are based on the nontoxic refrigerants for the environment, offer a sustained advantage when compared to the other types of the refrigerants. But, whichever might be the case,...

  19. 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.

  20. 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.

  1. 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.

  2. Experimental investigation of the ecological hybrid refrigeration cycle

    OpenAIRE

    Cyklis Piotr; Kantor Ryszard; Ryncarz Tomasz; Górski Bogusław; Duda Roman

    2014-01-01

    The requirements for environmentally friendly refrigerants promote application of CO2 and water as working fluids. However there are two problems related to that, namely high temperature limit for CO2 in condenser due to the low critical temperature, and low temperature limit for water being the result of high triple point temperature. This can be avoided by application of the hybrid adsorption-compression system, where water is the working fluid in the adsorption high temperature cycle used ...

  3. A compact rotating dilution refrigerator

    CERN Document Server

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

    2013-01-01

    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 0.001 rad/s up to angular velocities in excess of 2.5 rad/s. The behavior of a high-Q mechanical resonator during rapid changes in rotation has also been investigated.

  4. 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 (4)He. 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. PMID:24182127

  5. Modeling of In-vehicle Magnetic refrigeration

    OpenAIRE

    Olsen, Ulrik Lund; Bahl, Christian; Engelbrecht, Kurt; Nielsen, Kaspar Kirstein; Tasaki, Y.; Takahashi, H.; Y. Yasuda

    2012-01-01

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

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

    International Nuclear Information System (INIS)

    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

  7. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats

    Institute of Scientific and Technical Information of China (English)

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-GaG12 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217 W·kg-1 and 0.404.

  8. 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.

  9. Study of Solar Driven Silica gel-Water based Adsorption Chiller

    Science.gov (United States)

    Habib, K.; Assadi, M. K.; Zainudin, M. H. B.

    2015-09-01

    In this study, a dynamic behaviour of a solar powered single stage four bed adsorption chiller has been analysed designed for Malaysian climate. Silica gel and water have been used as adsorbent-refrigerant pair. A simulation program has been developed for modeling and performance evaluation of the chiller using the meteorological data of Kuala Lumpur. The optimum cooling capacity and coefficient of performance (COP) are calculated in terms of adsorption/desorption cycle time and regeneration temperature. Results indicate that the chiller is feasible even when low temperature heat source is available. Results also show that the adsorption cycle can achieve a cooling capacity of 14 kW when the heat source temperature is about 85°C.

  10. The leiden dilution refrigerator

    International Nuclear Information System (INIS)

    In march 1971, the author constructed the first version of a new type of 3He-4He dilution refrigerator through which, in contrast with the conventional dilution refrigerator, 4He instead of 3He is circulated. It is possible to keep the 4He circulation entirely at low temperatures, by using the fountain effect in superfluid 4He. The most important advantage of this refrigerator is that the precooling of nearly pure 3He simply takes place in one (spiralled or straight) capillary through which both liquid helium phases flow in opposite directions, driven by the force of gravity. Heat exchangers with their often complicated technical constructions are avoided. The lowest temperature that can be achieved in the refrigerator is about 5 mK. In this thesis, experiments with and a thermodynamic analysis of this refrigerator are described

  11. ARTI Refrigerant Database

    Energy Technology Data Exchange (ETDEWEB)

    Calm, J.M.

    1992-04-30

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

  12. 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

  13. Cogeneration in breweries analysis and simulation of systems for simultaneous generation of power, heat and refrigeration using natural gas; Sistemas de refrigeracao a partir da cogeracao: analise e simulacao de propostas para o caso de cervejarias utilizando gas natural

    Energy Technology Data Exchange (ETDEWEB)

    Gallego, Antonio Garrido

    1998-07-01

    The present work analyses some proposals of cogeneration systems for the simultaneous generation of power, heat and refrigeration in a brewery. The requirements of steam, refrigeration and electricity, as well as the production of beer in a plant of the Antarctica Company, located in Jaguariuna - SP were collected monthly for the year of 1997. Three conceptions of systems using two gas turbines with heat recovery steam generator were then proposed to meet the surveyed demand. The proposals differ in the refrigeration system: the first one uses a traditional ammonia compression system while the second uses an ammonia absorption system, the third proposal is a combination of the compression and absorption systems. These proposals are compared to the present configuration which purchases electricity from the Public Utility for power and refrigeration (using an ammonia compression)system, and fuel oil to generate steam for process heat. The technical, economical and environmental feasibility of the proposals, as well as of the present configuration are discussed on the basis of mass balances, energy balances (first law of Thermodynamics), exergy fluxes (second law analysis), operational and capital cost, based on simulation of the performance of each configuration proposed to meet the monthly electricity, steam and refrigeration requirements for the referred plant. The turbines were chosen so as to meet the peek energy demand of the plant and two cases were simulated for each proposal: turbine operational meets only the demand of the plant and turbine operates at full load, selling electricity for the Public utility. Results obtained show that the current operational costs are higher than any of the proposals presented. The high capital costs of the proposals, though,make them less interesting financially. The simulation of the case of excess electricity to the Public Utility is very attractive, considering the cost of natural gas 3,38 U$/M btu and the fare of 40 U

  14. Cryogen-free dilution refrigerators

    International Nuclear Information System (INIS)

    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.

  15. Adsorption of mercury in coal-fired power plants gypsum slurry on TiO2/chitosan composite material

    Science.gov (United States)

    Gao, P.; Gao, B. B.; Gao, J. Q.; Zhang, K.; Chen, Y. J.; Yang, Y. P.; Chen, H. W.

    2016-07-01

    In this study, a simple method was used to prepare a chitosan adsorbent to mix with KI and TiO2. Gravimetric analysis (TG), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the samples before and after adsorption of Hg2+. A mercury adsorption experiment was also conducted in the gypsum slurry. The results show that using hydrobromic acid as a solvent of adsorbent resulted in a better adsorption effect than using acetic acid alone. Also, the sample (CS-KI/TiO2-HBr) had a maximum mercury adsorption capacity when the pH=5 and the t=50°C. The characterization experiments showed that the thermal stability of composite materials declined and the TiO2 uniformly dispersed in the surface of the samples with a lamellar structure, generating a lot of cracks and recesses that increased the reactive sites. Furthermore, when the TiO2 reacted with CS, it resulted in Ti-C, Ti-O and Ti-N bonds. The Br- can prevent the growth of TiO2 crystal grains and strengthen the ability of I- to remove mercury. The adsorption isotherm and kinetic results indicated that the adsorption behaviour of CS-KI/TiO2-HBr as it removes Hg2+ is an inhomogeneous multilayer adsorption process. The surface adsorption and intraparticle diffusion effects are both important in the Hg2+ adsorption process.

  16. Assessment of pressure swing adsorption as CO2 capture technology in coal-fired power plants

    OpenAIRE

    Riboldi, Luca

    2016-01-01

    Coal-based power generation is responsible for a significant share of CO2 emissions on a global scale. Technologies to drastically reduce coal carbon footprint are critical for meeting mitigation targets. Absorption, whether chemical or physical depending on the process framework, is commonly regarded as the most mature technology in this context. Nevertheless, absorption suffers from some drawbacks, such as high energy requirements and corrosion of process equipment. Adsorptio...

  17. NREL's Energy-Saving Technology for Air Conditioning Cuts Peak Power Loads Without Using Harmful Refrigerants (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-07-01

    This fact sheet describes how the DEVAP air conditioner was invented, explains how the technology works, and why it won an R&D 100 Award. Desiccant-enhanced evaporative (DEVAP) air-conditioning will provide superior comfort for commercial buildings in any climate at a small fraction of the electricity costs of conventional air-conditioning equipment, releasing far less carbon dioxide and cutting costly peak electrical demand by an estimated 80%. Air conditioning currently consumes about 15% of the electricity generated in the United States and is a major contributor to peak electrical demand on hot summer days, which can lead to escalating power costs, brownouts, and rolling blackouts. DEVAP employs an innovative combination of air-cooling technologies to reduce energy use by up to 81%. DEVAP also shifts most of the energy needs to thermal energy sources, reducing annual electricity use by up to 90%. In doing so, DEVAP is estimated to cut peak electrical demand by nearly 80% in all climates. Widespread use of this cooling cycle would dramatically cut peak electrical loads throughout the country, saving billions of dollars in investments and operating costs for our nation's electrical utilities. Water is already used as a refrigerant in evaporative coolers, a common and widely used energy-saving technology for arid regions. The technology cools incoming hot, dry air by evaporating water into it. The energy absorbed by the water as it evaporates, known as the latent heat of vaporization, cools the air while humidifying it. However, evaporative coolers only function when the air is dry, and they deliver humid air that can lower the comfort level for building occupants. And even many dry climates like Phoenix, Arizona, have a humid season when evaporative cooling won't work well. DEVAP extends the applicability of evaporative cooling by first using a liquid desiccant-a water-absorbing material-to dry the air. The dry air is then passed to an indirect

  18. 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. PMID:24689798

  19. Performance Evaluation of a Continuous Operation Adsorption Chiller Powered by Solar Energy Using Silica Gel and Water as the Working Pair

    Directory of Open Access Journals (Sweden)

    Hassan Zohair Hassan

    2014-10-01

    Full Text Available In the present study, dynamic analysis and performance evaluation of a solar-powered continuous operation adsorption chiller are introduced. The adsorption chiller uses silica gel and water as the working pair. The developed mathematical model represents the heat and mass transfer within the reactor coupled with the energy balance of the collector plate and the glass cover. Moreover, a non-equilibrium adsorption kinetic model is taken into account by using the linear driving force equation. The variation of solar radiation, wind speed, and atmospheric temperature along a complete cycle are considered for a more realistic simulation. Based on the case studied  and the baseline parameters, the chiller is found to acquire a coefficient of performance of 0.402. The average thermal efficiency of the solar collector is estimated to be 62.96% and the average total efficiency  approaches a value of 50.91%. Other performance parameters obtained are 363.8 W and 1.82 W/kg for the cooling capacity and the specific cooling power of the chiller, respectively. Furthermore, every 1 kg of silica gel inside the adsorption reactor produces a daily chilled water mass of 3 kg at a temperature of 10 ◦C. In addition, the cooling system harnesses 25.35% of the total available solar radiation and converts it to a cooling effect.

  20. Joule Thomson refrigerator

    Science.gov (United States)

    Chan, Chung K. (Inventor); Gatewood, John R. (Inventor)

    1988-01-01

    A bi-directional Joule Thomson refrigerator is described, which is of simple construction at the cold end of the refrigerator. Compressed gas flowing in either direction through the Joule Thomson expander valve and becoming liquid, is captured in a container in direct continuous contact with the heat load. The Joule Thomson valve is responsive to the temperature of the working fluid near the valve, to vary the flow resistance through the valve so as to maintain a generally constant flow mass between the time that the refrigerator is first turned on and the fluid is warm, and the time when the refrigerator is near its coldest temperature and the fluid is cold. The valve is operated by differences in thermal coefficients of expansion of materials to squeeze and release a small tube which acts as the expander valve.

  1. 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}.

  2. A miniaturized plastic dilution refrigerator

    International Nuclear Information System (INIS)

    We have built and tested a miniaturized dilution refrigerator, completely contained (still, heat exchanger and mixing chamber) inside a plastic (PVC) tube of 10 mm diameter and 170 mm length. With a 25 cm2 CuNi heat exchanger, it reached temperatures below 50 mK, for circulation rates below 70 μmol/s. The cooling power at 100 mK and 63 μmol/s was 45 μW. The experimental space could accommodate samples up to 6 mm in diameter. (author)

  3. The new SMC dilution refrigerator

    International Nuclear Information System (INIS)

    The dilution refrigerator for the SMC twin solid polarized target at CERN is by far the largest one in operation. The 2.5 liter, 1.5 m long target is loaded horizontally into the cold mixing chamber. A cooling power of 400 mW at 300 mK temperature is available for dynamic nuclear polarization. Proton and deuteron targets are polarized to ±94% and ±47%, respectively. The base temperature of 30 mK enables rotation of the polarization vector without losses. copyright 1995 American Institute of Physics

  4. High temperature refrigerator

    Science.gov (United States)

    Steyert, Jr., William A.

    1978-01-01

    A high temperature magnetic refrigerator 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 said 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.

  5. 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.

  6. 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

  7. Analysis of a magnetic refrigerator

    International Nuclear Information System (INIS)

    A magnetic refrigerator consists of heat exchangers and beds of magnetic materials. The analysis considered a system that operates near room temperature in a magnetic field between 1 and 7.5 T and uses 3 kg of gadolinium (Gd) spheres, packed in two magnetocaloric beds. Different heat transfer fluids (water, ammonia, and R-134a) were used. The beds were periodically magnetized and demagnetized and the fluid flows were arranged to meet the cycle requirements. A sensitivity analysis was performed. Findings indicate that the higher the magnetic field, the higher the cooling power for the same temperature span. It was also observed that the cooling power decreases with increase in the temperature span for various magnetic fields. The ratio of COPactual to the COPCarnot decreases with an increase in the temperature span. These trends as well as magnitudes of cooling power and coefficient performance were compared with experimental measurements and found to be in reasonably good agreement. - Research highlights: → Coefficient of performance and cooling capacity of a magnetic refrigerator. → System analysis using heat transfer to and from the working fluid. → Development of the eight valve system for continuous operation.

  8. Power distribution system protection and electrical apparatus selection of refrigeration unit%制冷机组配电系统的保护及电器选择

    Institute of Scientific and Technical Information of China (English)

    李俊

    2012-01-01

    The low voltage electrical apparatus is one of important parts in refrigeration unit. The characteristics and the protection settings of compressor motor, the selection principles and the selectivity between low voltage electrical apparatus in refrigeration unit are described. The detailed selection and verification process of electrical apparatus are discussed through example.%低压电器是制冷机组的重要组成部分之一.本文详细描述压缩机电机的特性和保护设置、制冷机组常用低压电器的选择原则以及级间选择性,通过实例阐述电器的选择及校验过程.

  9. Waste Heat Recapture from Supermarket Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A [ORNL

    2011-11-01

    The objective of this project was to determine the potential energy savings associated with improved utilization of waste heat from supermarket refrigeration systems. Existing and advanced strategies for waste heat recovery in supermarkets were analyzed, including options from advanced sources such as combined heat and power (CHP), micro-turbines and fuel cells.

  10. 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 the...

  11. Modeling of In-vehicle Magnetic refrigeration

    DEFF Research Database (Denmark)

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

    2012-01-01

    A high-performance magnetic refrigeration device is considered as a potential technology for in-vehicle air conditioners in electric vehicles. The high power consumption of a conventional air conditioner in an electric vehicle has considerable impacts on cruising distance. For this purpose the...

  12. High-efficient thermochemical sorption refrigeration driven by low-grade thermal energy

    Institute of Scientific and Technical Information of China (English)

    LI TingXian; WANG RuZhu; WANG LiWei

    2009-01-01

    Thermochemical sorption refrigeration powered by low-grade thermal energy is one of the en ergy-saving and environment friendly green refrigeration technologies. The operation principle of sorption refrigeration system is based on the thermal effects of reversible physicochemical reaction processes between sorbents and refrigerants. This paper presents the developing study on the differ ent thermochemical sorption refrigeration cycles, and some representative high-efficient thermo chemical sorption refrigeration cycles were evaluated and analyzed based on the conventional single-effect sorption cycle. These advanced sorption refrigeration cycles mainly include the heat and mass recovery sorption cycle, double-effect sorption cycle, multi-effect sorption cycle, combined douhie-way sorption cycle, and double-effect and double-way sorption cycle with internal heat recovery.Moreover, the developing tendency of the thermochemical sorption refrigeration is also predicted in this paper.

  13. Progress of helium refrigeration system for Wendelstein 7-X

    International Nuclear Information System (INIS)

    The helium refrigerator for the fusion experiment Wendelstein 7-X is required for cooling the superconducting coils, casings, supports and divertor cryo-vacuum pumps at 3.4 K in peak power and 3.9 K in standard operating modes. The refrigerator supplied by Linde Kryotechnik AG has an equivalent refrigeration power of 7 kW at 4.5 K. In the meantime the corresponding hardwares are installed and the commissioning is approaching towards completion. The preparations for the acceptance tests have begun. (author)

  14. Short Time Cycles of Purely Quantum Refrigerators

    CERN Document Server

    Feldmann, Tova

    2012-01-01

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

  15. Ethanol adsorption onto carbonaceous and composite adsorbents for adsorptive cooling system

    International Nuclear Information System (INIS)

    The aim of the present paper is the experimental characterization of adsorbent materials suitable for practical applications in adsorption refrigeration systems, employing ethanol as refrigerant. Different commercial activated carbons as well as a properly synthesized porous composite, composed of LiBr inside a silica gel host matrix, have been tested. A complete thermo-physical characterization, comprising nitrogen physi-sorption, specific heat and thermo-gravimetric equilibrium curves of ethanol adsorption over the sorbents, has been carried out. The equilibrium data have been fitted by means of the Dubinin – Astakhov equation. On the basis of the experimental data, a thermodynamic evaluation of the achievable performance of each adsorbent pair has been estimated by calculating the maximum COP (Coefficient of Performance) under typical working boundary conditions for refrigeration and air conditioning applications. The innovative composite material shows the highest thermodynamic performances of 0.64–0.72 for both tested working conditions. Nevertheless, the best carbonaceous material reaches COP value comparable with the synthesized composite. The results have demonstrated the potential of the chosen adsorbents for utilization in adsorption cooling systems. - Highlights: • We studied ethanol adsorption for adsorption cooling systems. • Commercial activated carbons and composite sorbent, LiBr/SiO2, are tested by complete thermo-physical characterization. • A thermodynamic evaluation has been carried out on each working pairs to estimate the performance of a refrigeration cycle

  16. Refrigeration system for W7-X

    International Nuclear Information System (INIS)

    The refrigeration system for the W7-X superconducting magnet and the divertor cryo-vacuum pumps is presented. In total, five main helium cooling circuits have to be supplied by the refrigerator-four for the magnet including auxiliary equipment like support structure, thermal shield and current leads, and one for the cryo-pumps. For the shields of the latter, an additional LN2-cooling circuit is required. The lowest operating temperature is 3.3 K. It will be provided by evacuating a sub-cooler bath using a cold or warm compressor. Three of the helium cooling circuits use altogether four identical cold circulators. Apart from the current leads which are supplied with the coolant from a LHe storage tank, the peak reserve power required is equal to 7 kW at 4.5 K entropy equivalent. However, this potential maximal demand occurs continuously for periods of only a few hours at most, and altogether for less than 1% of annual time. The refrigerator thus will be designed for 5 kW continuous power at 4.5 Kequiv. corresponding to 1.5 MW compressor connected rating. The reserve peak power will be covered, if necessary, by using the latent heat and vapour enthalpy of LHe from a storage tank. This supporting LHe stream is added to the phase separator and fed subsequently to the low pressure return stream at the cold end of the cold box. LN2-pre-cooling equipment of the cold box - which is installed for W7-X cool-down anyway - can also be used to increase refrigeration power. The LHe required for maintaining reserve refrigeration power as well as for running the current leads is generally produced overnight when W7-X is in idle current mode. (author)

  17. A Cooling System for an Automobile Based on Vapour Absorption Refrigeration Cycle Using Waste Heat of an Engine.

    OpenAIRE

    Satish K. Maurya; Saurabh Awasthi

    2014-01-01

    Now a days the air conditioning system of cars is mainly uses “Vapour Compression Refrigerant System” (VCRS) which absorbs and removes heat from the interior of the car that is the space to be cooled and rejects the heat to atmosphere. In vapour compression refrigerant system, the system utilizes power from engine shaft as the input power to drive the compressor of the refrigeration system, hence the engine has to produce extra work to run the compressor of the refrigerating s...

  18. The Vienna Nuclear Demagnetization Refrigerator

    International Nuclear Information System (INIS)

    A new nuclear demagnetization system coupled to a powerful dilution refrigerator and a vector magnet was successfully built and operated. Our aim was to construct a versatile, modular cryostat, with a large experimental space providing an excellent platform for various types of ultralow temperature measurements. A powerful dilution unit allows us to cool the mixing chamber down to 3 mK and to precool a massive copper (∼90 mol) nuclear stage in a field of 9 T to 8 mK in 100 h. After demagnetization the lowest temperature of the copper stage measured by a Pt thermometer was 50.9 μK in a field of 20 mT. The cryostat is integrated with a 8 T-4 T vector magnet system. The refrigerator is provided with a 50 mm central clear shot tube allowing the insertion of a top-loading probe to cool down samples for measurements inside the vector magnet bore in a reasonably short time of about 4 hours. The system will be used to study quantum critical behavior of heavy fermion compounds.

  19. Optimized Performance of One-Bed Adsorption Cooling System

    OpenAIRE

    Miyazaki, Takahiko; El-Sharkawy, Ibrahim I.; Saha, Bidyut Baran; Koyama, Shigeru

    2014-01-01

    Adsorption cooling system can be driven by solar energy or waste heat, so it will effectively reduce fossil fuel consumptions when total system is well-designed. On the other hand, the system tends to have a large size, which will be an obstacle to install adsorption cooling systems to small to medium scale cooling demands, such as automobiles, houses, or shops. The study was aiming at the reduction of system size of adsorption cooling systems for refrigeration and air-conditioning applicatio...

  20. Performance Analysis of Vapour Compression Refrigeration System Utilizing Different Refrigerant

    OpenAIRE

    Ashish Patidar 1; Amitesh Paul

    2014-01-01

    The performance of heat transfer is one of the most important research areas in the field of thermal engineering. There are a large number of refrigerants, which are used to transfer heat from low temperature reservoir to high temperature reservoir by using vapour compression refrigeration system. This paper presents a performance analysis of vapour compression refrigeration system with using refrigerants like R-134a & Blend of R-290(propane) (50%) and R-600a (50% Isobutane). ...

  1. 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.

  2. Removal and adsorption of radioactive cesium from contaminated soil caused by the Fukushima Daiichi Nuclear Power Station accident

    International Nuclear Information System (INIS)

    The removal and adsorption of radioactive cesium, 137Cs or 134Cs, from contaminated soil was investigated using various extractants: sodium hydroxide, hydrochloric acid, and sulfuric acid. In this experiment, a sand sample was used as contaminated soil. Although the radioactive cesium could not be removed from the soil by using sodium hydroxide, 64% of the removal efficiency was provided at room temperature when 10 M hydrochloric acid was used. Eighty percent of the radioactive cesium was removed by using 1 M sulfuric acid containing 0.1 M thiourea at 90℃. A more than 90% removal efficiency was obtained by increasing of the volume of sulfuric acid containing thiourea. The same result was obtained using custom-made radioactive cesium removal equipment. The adsorption of the radioactive cesium was also investigated. In an experiment of concerning adsorption, contaminated water containing radioactive cesium was prepared from a contaminated sand sample. More than 96% adsorption was obtained using zeolite (clinoptilolite). However, when commercial activated carbon was used, most the radioactive cesium was hardly removed. The influence of shaking time on the adsorption of radioactive cesium was investigated by a batch-system using zeolite. As a result, a shaking time of at least 5 min showed that the radioactive cesium was quantitatively adsorbed to zeolite. The adsorptive behavior of the radioactive cesium by a flow-system was also examined using zeolite. (author)

  3. Hey you! Shut the refrigerator door!

    Science.gov (United States)

    Fay, Sarah; Portenga, Angela

    1998-09-01

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

  4. 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.

  5. Design and experimental investigation of portable solar thermoelectric refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Abdul-Wahab, Sabah A.; Al-Habsi, Is' haq A.; Al-Rubai' ey' , Hilal S.; Al-Battashi, Abdulaziz K.; Al-Tamimi, Ali R.; Al-Mamari, Khamis H. [Sultan Qaboos University, College of Engineering, Mechanical and Industrial Engineering Department, P.O. Box 33, Al Khoud P.C. 123, Muscat (Oman); Elkamel, Ali; Chutani, Muhammad U. [Department of Chemical Engineering, University of Waterloo, 200 University Avenue Wes, Waterloo, Ontario (Canada); Al-Damkhi, Ali M. [Department of Environmental Sciences, College of Health Sciences, Public Authority for Applied Education and Training (PAAET) (Kuwait)

    2009-01-15

    The main objective of this study is to design and build an affordable solar thermoelectric refrigerator for the Bedouin people (e.g. deserts) living in remote parts of Oman where electricity is still not available. The refrigerator could be used to store perishable items and facilitate the transportation of medications as well as biological material that must be stored at low temperatures to maintain effectiveness. The design of the solar-powered refrigerator is based on the principles of a thermoelectric module (i.e., Peltier effect) to create a hot side and a cold side. The cold side of the thermoelectric module is utilized for refrigeration purposes; provide cooling to the refrigerator space. On the other hand, the heat from the hot side of the module is rejected to ambient surroundings by using heat sinks and fans. The designed solar thermoelectric refrigerator was experimentally tested for the cooling purpose. The results indicated that the temperature of the refrigeration was reduced from 27 C to 5 C in approximately 44 min. The coefficient of performance of the refrigerator (COP{sub R}) was calculated and found to be about 0.16. (author)

  6. 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....

  7. Continuous magnetic refrigeration in the superfluid helium range

    International Nuclear Information System (INIS)

    An experimental prototype magnetic refrigerator based on the well known adiabatic demagnetization principle is described. A continuous process is employed in which gadolinium garnet follows successive magnetization-demagnetization cycles between a hot liquid helium source at 4.2K and a cold superfluid helium source at T<= 2.16K. The performance achieved with the first version is as follows: - limiting temperature at zero utilizable power: 1.32K; - utilizable power of 1.2W at 1.8K with an efficiency of 45%. In a second version, it was possible to increase the efficiency to 64% for a utilizable power of 0.9W at 2.1K. Same general remarks are made on the possibility of extrapolating to a 300W refrigerator operating at 1.8K, on a continuous rotating magnetic refrigerator of a different design, and on efficiency comparisons between gas and magnetic refrigerators

  8. Magnetic refrigerator for hydrogen liquefaction

    OpenAIRE

    Matsumoto, Koichi; Kondo, T.; Yoshioka, S; Kamiya, K.; Numazawa, T.

    2009-01-01

    Magnetic refrigeration which is based on the magnetocaloric effect of solids has the potential to achieve high thermal efficiency for hydrogen liquefaction. We have been developing a magnetic refrigerator for hydrogen liquefaction which cools down hydrogen gas from liquid natural gas temperature and liquefies at 20 K. The magnetic liquefaction system consists of two magnetic refrigerators: Carnot magnetic refrigerator (CMR) and active magnetic regenerator (AMR) device. CMR with Carnot cycle s...

  9. A resorption cycle for the cogeneration of electricity and refrigeration

    International Nuclear Information System (INIS)

    Graphical abstract: A novel resorption cycle driven by low grade heat for cogeneration of electricity and refrigeration is studied. The cycle features in high exergy efficiency, very little or no ammonia liquid inside and simple structure. Highlights: ► A resorption cogeneration cycle for electricity and refrigeration is proposed. ► The cycle improved refrigeration COP by 10 times compared with Goswami cycle. ► The highest exergy efficiency of the cogeneration cycle is as high as 0.9. ► The cycle also features in safety and simple structure. - Abstract: This paper describes a novel resorption cycle driven by the low grade heat for the cogeneration of electricity and refrigeration, which is based on ammonia adsorption refrigeration technology. The presented cycle features a variable endothermic process which stands for higher adaptability if compared with the traditional Rankine cycle, very little or no ammonia liquid in the system which is a safety feature, solid adsorbents inside the beds, and simple structure for the fact of no rectifying equipment and circulation pumps required by the working fluids. This cycle can be utilised for the heat source with the temperature higher than 100 °C, and it has an electricity generation exergy efficiency of up to 0.69 and a refrigeration coefficient of performance (COP) of up to 0.77. If compared with the Goswami cycle, which is established based on the absorption Kalina cycle for the cogeneration of electricity and refrigeration, the novel resorption cycle kept the merit of the high exergy efficiency for electricity generation, meanwhile, it overcame the limitation of the low refrigeration coefficient of performance (COP) of Goswami cycle, and improved the COP by 10 times. The optimum overall exergy efficiency is as high as 0.9, which is 40–60% improved compared with the Goswami cycle under the same working conditions

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

    International Nuclear Information System (INIS)

    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

  11. 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.

  12. Exergy analysis of magnetic refrigeration

    OpenAIRE

    Lucia, Umberto

    2010-01-01

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

  13. 2013 German refrigeration and air conditioning meeting. Proceedings; Deutsche Kaelte- und Klimatagung 2013. Tagungsbericht

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-07-01

    These proceedings cover the following main topics: cryoengineering - superconduction / energy storage; cryoapplications in biology and medicine; metrology; adsorption processes; condensation/evaporation; working fluids / simulation; ice production; plants and compressors; expansion and ejectors or recooling; use of cooling (passenger car air conditioning, supermarket); refrigerants; plant efficiency; emissions and legislation; air conditioning and use of heat pumps; air quality and control; building technology and block-type thermal power stations. [German] Dieser Tagungsbericht enthaelt folgende Themenschwerpunkte: Kryotechnik - Supraleitung/Energiespeicher; Kryoanwendungen in der Biologie und Medizin; Messtechnik; Adsorptionsprozesse; Kondensation/Verdampfung; Arbeitsfluide/Simulation; Eiserzeugung; Anlagen und Verdichter; Expansion und Ejektoren bzw. Rueckkuehlung; Kaelteanwendung (PKW-Klimatisierung; Supermarkt); Kaeltemittel; Anlageneffizienz; Emissionen und Gesetzgebung; Klimatechnik und Waermepumpenanwendung; Luftqualitaet und Regelung; Gebaeudetechnik und BHKW.

  14. 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.

  15. Optimal thermal refrigerator

    OpenAIRE

    Allahverdyan, Armen E.; Hovhannisyan, Karen; Mahler, Guenter

    2009-01-01

    We study a refrigerator model which consists of two $n$-level systems interacting via a pulsed external field. Each system couples to its own thermal bath at temperatures $T_h$ and $T_c$, respectively ($\\theta\\equiv T_c/T_h

  16. Fundamentals of Refrigeration.

    Science.gov (United States)

    Sutliff, Ronald D.; And Others

    This self-study course is designed to familiarize Marine enlisted personnel with the principles of the refrigeration process. The course contains five study units. Each study unit begins with a general objective, which is a statement of what the student should learn from the unit. The study units are divided into numbered work units, each…

  17. Education in Helium Refrigeration

    International Nuclear Information System (INIS)

    On the one hand, at the end of the time I was active in helium refrigeration, I noticed that cryogenics was stepping into places where it was not yet used. For example, a conventional accelerator, operating at room temperature, was to be upgraded to reach higher particle energy. On the other hand, I was a little bit worried to let what I had so passionately learned during these years to be lost. Retirement made time available, and I came gradually to the idea to teach about what was my basic job. I thought also about other kinds of people who could be interested in such lessons: operators of refrigerators or liquefiers who, often by lack of time, did not get a proper introduction to their job when they started, young engineers who begin to work in cryogenics... and so on.Consequently, I have assembled a series of lessons about helium refrigeration. As the audiences have different levels of knowledge in the field of cryogenics, I looked for a way of teaching that is acceptable for all of them. The course is split into theory of heat exchangers, refrigeration cycles, technology and operation of main components, process control, and helium purity

  18. Efficiency analysis of alternative refrigerants for ejector cooling cycles

    International Nuclear Information System (INIS)

    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

  19. The design and control of mine refrigeration systems

    OpenAIRE

    Howes, Michael

    1992-01-01

    The research is directed towards modelling the chiller set, the heat rejection and the load subsystems of a complete mine refrigeration system and simulating the performance in order that the design can be optimised and the most cost effective control system determined. The refrigeration load profile for a mechanised mine is complex and primarily a function of surface climatic variations, the strongly cyclic sources of heat resulting from the operation of diesel powered mining equipment and t...

  20. Modeling and simulation of an activated carbon–CO2 four bed based adsorption cooling system

    International Nuclear Information System (INIS)

    Highlights: • A transient mathematical model of a 4-bed adsorption chiller is proposed. • The performances of the cyclic-steady-state system are presented for different heating and cooling water inlet temperatures. • The desorption pressure has a big influence in the performances. • With 80 kg of Maxsorb III, the CO2 based adsorption chiller produces 2 kW of cooling power and presents a COP of 0.1. - Abstract: In this study, a transient mathematical model of a 4-bed adsorption chiller using Maxsorb III as the adsorbent and CO2 as the refrigerant has been analyzed. The performances of the cyclic-steady-state system are presented for different heating and cooling water inlet temperatures. It is found that the desorption pressure has a big influence in the performances due to the low critical point of CO2 (Tc = 31 °C). With 80 kg of Maxsorb III, the CO2 based adsorption chiller produces 2 kW of cooling power and presents a COP of 0.1, at driving heat source temperature of 95 °C along with a cooling temperature of 27 °C and at optimum desorption pressure of 79 bar. The present thermal compression air-conditioning system could be driven with solar energy or waste heat from internal combustion engines and therefore is suitable for both residential and mobile air-conditioning applications

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

    International Nuclear Information System (INIS)

    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][BF4] (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][BF4] showed the best performance of COP. ► The effects of high viscosity ILs on the system performance are not significant.

  2. Determination of a Vapor Compression Refrigeration System Refrigerant Charge

    Institute of Scientific and Technical Information of China (English)

    YangChun-Xin; DangChao-Bin

    1995-01-01

    A physical model is established in this paper to describe the heat transfer and two phase flow of a refrigerant in the evaporator and condenser of a vapor compression refrigeration system.The model in then used to determine the refrigerant charge in vapor compression units.The model is used for a sensitivity analysis to determine the effect that varing design parameters on the refrigerant charge,The model is also used to evaluate the effect of refrigerant charge and the thermal physical properties on the refrigeration cycle,The predicted value of the refigerant charge and experimental data agree well The model and the method presented in this paper could be used to design vapour compression units such as domestic refrigeratirs and air conditioners.

  3. Design of Heat Pipe Type Adsorption Ice Maker for Fishing Boats%热管型船用吸附制冰机的设计

    Institute of Scientific and Technical Information of China (English)

    王丽伟; 王如竹; 夏再忠; 吴静怡

    2005-01-01

    A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6 kW, 217W·kg-1 and 0.404.

  4. Oxygen chemisorption cryogenic refrigerator

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    1987-01-01

    The present invention relates to a chemisorption compressor cryogenic refrigerator which employs oxygen to provide cooling at 60 to 100 K. The invention includes dual vessels containing an oxygen absorbent material, alternately heated and cooled to provide a continuous flow of high pressure oxygen, multiple heat exchangers for precooling the oxygen, a Joule-Thomson expansion valve system for expanding the oxygen to partially liquefy it and a liquid oxygen pressure vessel. The primary novelty is that, while it was believed that once oxygen combined with an element or compound the reaction could not reverse to release gaseous oxygen, in this case oxygen will indeed react in a reversible fashion with certain materials and will do so at temperatures and pressures which make it practical for incorporation into a cryogenic refrigeration system.

  5. Compact acoustic refrigerator

    Science.gov (United States)

    Bennett, Gloria A.

    1992-01-01

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

  6. International solar refrigeration system

    International Nuclear Information System (INIS)

    An intermittent solar refrigeration system using ammonia as refrigerant and water as absorbent, is fabricated and tested in the Center for Renewable Energy Research and Application. In this system, using solar flat plate collectors, ammonia is separated from the water-ammonia solution with quality 60%, during the day and its cooling effect happens during the night time. The system can be used in areas with high solar intensity in Iran. A comparison between the theoretical and experimental results shows that the average amount of coefficient of performance are close (COPthe=0.485, COPexp=0.432). This result represents the potent rol accessibility to temperature below 10deg C, while the ambient temperature is about 30deg C

  7. 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.

  8. Superfluid thermodynamic cycle refrigerator

    International Nuclear Information System (INIS)

    A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of 3He in a single phase 3He-4He solution. The 3He in superfluid 4He 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 3He at an initial concentration in superfluid 4He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of 4He while restricting passage of 3He. The 3He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K. 12 figs

  9. Reciprocating Magnetic Refrigerator

    Science.gov (United States)

    Johnson, D. L.

    1985-01-01

    Unit cools to 4 K by adiabatic demagnetization. Two porous matrices of paramagnetic material gadolinium/gallium/garnet held in long piston called displacer, machined out of Micarta (phenol formaldehyde polymer). Holes in side of displacer allow heat-exchange fluid to flow to and through matrices within. Piston seals on displacer prevent substantial mixing of fluid in two loops. Magnetic refrigerator provides continuous rather than "one-shot" cooling.

  10. Multilayer Thermionic Refrigeration

    Energy Technology Data Exchange (ETDEWEB)

    Mahan, G.D.

    1999-08-30

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

  11. Adsorption Chillers : uptake of Ethanol on Type RD Silica gel

    OpenAIRE

    Arnoldsson, Joel

    2012-01-01

    The adsorption cooling technology has the potential to replace all vapor compression based chillers in the future. So, in all over the world immense researches are going on in this field. The purpose of this report is to experimentally investigate whether ethanol could serve as a refrigerant in the technology. Compared to water it has freezing point below 0 °C (-114.1 °C) and can therefore in theory be used in refrigeration applications. The report begins with the theory regarding the adsorpt...

  12. 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.

  13. Working pairs for resorption refrigerator

    International Nuclear Information System (INIS)

    The performances of three chemisorption working pairs operating under the resorption cycle were studied gravimetrically by comparing the desorbed and adsorbed mass of refrigerant in different operation conditions. All pairs used NH3 as refrigerant and MnCl2 in the main reactor, but each one used a different salt for the cooling effect production in the secondary reactor. These salts were NH4Cl or NaBr or BaCl2. The experimental results indicated that the degree of conversion in reaction between the NH3 and BaCl2 was inferior to 25% during cooling production at 0 oC or below, whereas the reactions with the other salts had conversions of at least 80%. When the systems operated with heat source temperature for the main reactor at 155 oC, heat sink temperature for both reactors at 30 oC, and cooling effect production temperature at 0 oC the coefficient of performance (COP) of the system using NH4Cl and the system using NaBr were similar and around 0.30; however, the former system had a specific cooling power (SCP) 5% higher than that of the latter system. Because the reaction in the system with NH4Cl was practically halted in a period much shorter than that used in the experiments, it is possible to expect that if the period of the cooling period was shortened, the difference between the SCP of those systems would be much higher. - Highlights: → The comparison of three different working pairs operating under resorption cycle was conducted. → The three working pairs were NH4Cl/MnCl2, NaBr/MnCl2, BaCl2/MnCl2, respectively. → The mass of refrigerant reacted in different situations were measured and compared. → Among the LTS studied, NH4Cl is the most suitable to be used in a resorption machine at 0 or below 0 oC.

  14. The optimization of Stirling refrigerator and Stirling heat engine

    Science.gov (United States)

    Zhu, Xin-Mei

    2007-03-01

    The optimization of an irreversible Stirling refrigerator or a Stirling heat engine is an important research subject for a long time. Taking into account of the influence of mixed thermal resistance and regeneration loss in the performance study, we have derived the optimal relation of both of them. For Stirling refrigerator, we have deduced the optimal relation between the thermal resistance coefficient and the efficiency. To the Stirling heat engine, we have deduced the optimal relation between the power output and the efficiency. The conclusions obtained mirror the observed performance of the Stirling refrigerator or the Stirling heat engine quite well. Thus, the results may provide a new theoretical guidance to the optimal design and the selection of optimal operating condition of the Stirling refrigerator or the Stirling heat engine.

  15. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Performance evaluation of integrated trigeneration and CO2 refrigeration systems

    International Nuclear Information System (INIS)

    Food retailing is one of the most energy intensive sectors of the food cold chain. Its environmental impacts are significant not only because of the indirect effect from CO2 emissions at the power stations but also due to the direct effect arising from refrigerant leakage to the atmosphere. The overall energy efficiency of supermarkets can be increased by integrating the operation of CO2 refrigeration and trigeneration systems. This paper compares three alternative schemes in a medium size supermarket. Experimental results and simulation studies have shown that the best scheme for energy and GHG emissions savings is the one where the cooling produced by the trigeneration system is used to condense the CO2 fluid in the refrigeration system to ensure subcritical operation throughout the year. It is shown that this system can produce 30% energy savings and over 40% greenhouse gas emissions savings over conventional refrigeration and indoor environment control systems in supermarkets.

  17. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    International Nuclear Information System (INIS)

    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)

  18. Improving Control in a Joule-Thomson Refrigerator

    Science.gov (United States)

    Borders, James; Pearson, David; Prina, Mauro

    2005-01-01

    A report discusses a modified design of a Joule-Thomson (JT) refrigerator under development to be incorporated into scientific instrumentation aboard a spacecraft. In most other JT refrigerators (including common household refrigerators), the temperature of the evaporator (the cold stage) is kept within a desired narrow range by turning a compressor on and off as needed. This mode of control is inadequate for the present refrigerator because a JT-refrigerator compressor performs poorly when the flow from its evaporator varies substantially, and this refrigerator is required to maintain adequate cooling power. The proposed design modifications include changes in the arrangement of heat exchangers, addition of a clamp that would afford a controlled heat leak from a warmer to a cooler stage to smooth out temperature fluctuations in the cooler stage, and incorporation of a proportional + integral + derivative (PID) control system that would regulate the heat leak to maintain the temperature of the evaporator within a desired narrow range while keeping the amount of liquid in the evaporator within a very narrow range in order to optimize the performance of the compressor. Novelty lies in combining the temperature- and cooling-power-regulating controls into a single control system.

  19. 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...

  20. Refrigerator-freezer energy testing with alternative refrigerants

    Science.gov (United States)

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

    1989-07-01

    As a result of the Montreal Protocol that limits the production of ozone-depleting refrigerants, manufacturers are searching for alternatives to replace the R12 that is presently used in residential refrigerator-freezers. Before an alternative can be selected, several issues must be resolved. Among these are energy impacts, system compatibility, cost, and availability. In an effort to determine the energy impacts of some of the alternatives, energy consumption tests were performed in accordance with section 8 of the Association of Home Appliance Manufacturers (AHAM) standard for household refrigerators and household freezers. The results are presented for an 18 cubic foot (0.51 cubic meter), top-mount refrigerator-freezer with a static condenser using the following refrigerants: R12, R500, R12/Dimethyl-ether (DME), R22/R142b, and R134a. Conclusions from the AHAM test are that R500 and R12 /DME have a reduced energy consumption relative to R12 when replaced in the test unit with no modifications to the refrigeration system. Run times were slightly lower than R12 for both refrigerants indicating a higher capacity. While the R134a and R22/R142b results were less promising, changes to the refrigeration system, such as a different capillary tube or compressor, may improve performance.

  1. Space-borne He-3 refrigerator

    Science.gov (United States)

    Duband, L.; Hui, L.; Lange, A.

    1990-01-01

    A space-compatible He-3 refrigerator is being developed for cooling the bolometric detectors of the Far Infrared Photometer (FIRP) in the Infrared Telescope in Space (IRTS). The refrigerator is self-contained and compact, and can be recycled in zero gravity with low power dissipation (20 mW or less). A laboratory prototype that contains 2 STP cu dm of He-3 has been successfully cycled upside-down, i.e., against gravity, thus proving the feasibility of the cycle in zero gravity. Sintered copper confines the He-3 to the evaporator during the low temperature phase. Temperatures as low as 280 mK have been achieved with this configuration. Other types of porous material which have lower mass density are currently under investigation.

  2. Materials and device concepts for electrocaloric refrigeration

    Science.gov (United States)

    Suchaneck, G.; Gerlach, G.

    2015-09-01

    Electrocaloric (EC) materials provide a solid-state cooling technology without polluting liquid refrigerants and noisy mechanical parts. Currently, basic research in this field is mainly focused on materials with a first-order phase transition exhibiting a large polarization change in a narrow temperature region near the phase transition point (Curie temperature) and, thus, a large EC effect. In this contribution, device operation above Curie temperature will be discussed. In this case, the polarization change originates from the temperature coefficient of the dielectric permittivity. To optimize material properties for EC refrigerator applications, we adapt the modified Curie-Weiss law describing a large class of ferroelectrics with a diffuse phase transition. Device performance will be evaluated based on the expected cooling power in dependence on thermodynamic cycle time, total thermal resistance and EC material thickness.

  3. Theoretical research of a silica gel-water adsorption chiller in a micro combined cooling, heating and power (CCHP) system

    Energy Technology Data Exchange (ETDEWEB)

    Li, S.; Wu, J.Y. [Shanghai Jiao Tong University, Institute of Refrigeration and Cryogenics, Dongchuan Road 800, Shanghai 200240 (China)

    2009-06-15

    A novel micro CCHP system, which is based on a two bed silica gel-water adsorption chiller, is constructed in this work. To reveal the chiller characteristic in this system, a transient model of the adsorption chiller is developed. According to the comparison of the simulated results and experimental data, the presented model shows a good performance in predicting the chiller performance, with both stable and variable heat source temperature. With the analysis of simulated results, it is found that the cooling capacity and the coefficient of performance (COP) of the chiller are influenced significantly by the average value and variation rate of electric load, as well as the average value of cooling load. The water tank also shows a great effect on the chiller performance. To get better performance of the chiller, the water tank should be adopted when the electric load is low or its variation rate is positive, and should not be utilized when the electric load is high or its variation rate is negative. A 500 L water tank is recommended in order to get better performance and acceptable start-up time. Furthermore, to get better performance as well as higher security, a cold accumulator should be adopted. (author)

  4. Self-supporting refrigerated truck

    NARCIS (Netherlands)

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

    1997-01-01

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

  5. Energy optimisation of domestic refrigerators

    DEFF Research Database (Denmark)

    Jakobsen, Arne; Rasmussen, Bjarne D.

    1998-01-01

    using a variable speed compressor for controlling the capacity of the refrigeration system.2) Introducing a variable speed fan for enhancing the heat transfer in the evaporator.It was the aim of the project to reduce the energy consumption of a standard refrigerator, available on the market today, by 50 %....

  6. Energy Efficiency of Refrigeration Systems

    OpenAIRE

    Arnemann, Michael

    2012-01-01

    Energy efficiency plays an important role in the development and operation of refrigeration systems. The method of the VDMA 24247-2 2 “Energy efficiency of refrigeration systems – Requirements for the system design and the components” were recently published. The method will be described within this paper, with the focus on the graphical interpretation.

  7. Magnetic refrigerator for hydrogen liquefaction

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-01

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

  8. Magnetic refrigerator for hydrogen liquefaction

    International Nuclear Information System (INIS)

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

  9. Design study of 1.8 K 200 W helium refrigeration system

    International Nuclear Information System (INIS)

    The superconducting RF cavities of the superconducting proton linac will be cooled by superfluid helium below 2.0 K. The cooling test of the superconducting RF cavities will be required about 200 W of cooling power at 1.8 K. Refrigeration using superfluid helium is required a helium refrigeration system cooling down to 1.8 K. A cold compressor is a key component for the system. IHI carried out 1.8 K 200 W helium refrigeration system design for cooling test of the superconducting RF cavities. The preliminary design study of the 1.8 K 200 W helium refrigeration system is presented. (author)

  10. A review of magnetic refrigerator and heat pump prototypes built before the year 2010

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Bingfeng; Liu, Min [School of Energy and Power Engineering, Xi' an Jiaotong University, 28, Xianning West Road, Xi' an 710049 (China); Egolf, Peter W.; Kitanovski, Andrej [University of Applied Sciences of Western Switzerland, Institute of Thermal Sciences, CH-1401 Yverdon-les-Bains (Switzerland)

    2010-09-15

    Magnetic refrigeration, heating and power conversion technologies are interesting alternatives to the conventional refrigeration, heat pumping and different conventional energy conversion technologies. At present they all show a realistic potential to enter conventional markets, respectively to be applied in a few years. In this review paper, mainly magnetic refrigeration and magnetic heating are addressed and from these two technologies the main part is dedicated to magnetic refrigeration at room temperature. This article covers the demand of giving a complete list and description of existing magnetic heating and cooling prototypes up to the year 2010. Forty-one machines, their components and operation principles are presented in detail. (author)

  11. A Tiltable Single-Shot Miniature Dilution Refrigerator for Astrophysical Applications

    CERN Document Server

    Melhuish, Simon J; Piccirillo, Lucio

    2012-01-01

    We present a 3He / 4He dilution refrigerator designed for cooling astronomical mm-wave telescope receivers to around 100 mK. Used in combination with a Gi?fford-McMahon closed-cycle refrigerator, 4He and 3He sorption-pumped refrigerators, our cryogen-free system is capable of achieving 2 microW cooling power at 87 mK. A receiver attached directly to the telescope optics is required to rotate with respect to the downward direction. This scenario, of variable tilt, has proved difficult for typical dilution refrigerators, but our design has a geometry chosen to allow tilt to 45 degrees and beyond.

  12. Performance test of a helium refrigerator for the cryogenic hydrogen system in J-PARC

    CERN Document Server

    Tatsumoto, H; Kato, T; Ohtsu, K; Hasegawa, S; Maekawa, F; Futakawa, M

    2009-01-01

    In J-PARC, a cryogenic hydrogen system, which plays a role in providing supercritical hydrogen with a pressure of 1.5 MPa and a temperature of 20 K to three moderators, has been designed. The performance test of the helium refrigeration system that is a part of the cryogenic hydrogen system was conducted independently. The helium refrigeration system was cooled down to 18 K within 4.5 hours, and the refrigerator power of 6.45 kW at 15.6 K was confirmed. The performance test results verified that the helium refrigerator satisfied the performance requirements.

  13. An alternative method to estimate refrigeration system inventory

    International Nuclear Information System (INIS)

    Refrigeration system performance is directly related to the refrigerant mass charge in the equipment. This means that there is an optimum fluid amount that requires less power usage and contributes indirectly to a reduction in greenhouse gas output. Another important factor in fluid charge optimization is that it protects against compressor failure. The best approach for predicting refrigeration system inventory is to find the distribution of refrigerant mass in the evaporator and condenser. This work presents an alternative method for estimation of the refrigeration system inventory based on the first law of thermodynamics and the void fraction correlation of Hughmark. The average error of this alternative method was 5.1% and 7.2% for the first and second experimental validations, respectively, whereas the classical method of Otaki produced an error of 10%. Additionally, a convergence study and a sensitivity test were carried out. This alternative method is especially relevant for unusual heat exchanger geometries, when the external heat transfer coefficient is difficult to obtain from the literature. -- Highlights: ► We create an alternative method to determine the refrigerant charge inventory. ► We carried out experimental validations of this new method. ► We performed a convergence test and sensitivity test to verify the accuracy of the method. ► The results show that the new method generates excellent results. ► The new method has a relevant application in cases of uncommon external geometry

  14. THERMODYNAMIC ANALYSIS OF REFRIGERANT MIXTURES IN VAPOR COMPRESSION REFRIGERATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Erol ARCAKLIOĞLU

    2003-02-01

    Full Text Available In this study, performance analysis of vapor-compression refrigeration system with suction/liquid line heat exchanger has been realized with the calculations of the coefficient of performance, and volumetric refrigeration capacity values using different refrigerant mixtures. Refrigerants R12, R22, and R502 of CFCs, R134a, R152a, R125, R143a, and R32 of HFCs, R600a, and R290 of HCs, and their binary, ternary, and mixtures of different mass ratios have been used as working fluids. In order to decrease global pollution due to CFCs in accordance with Montreal Protocol in 1987, it is considered to use the refrigerant mixtures of HFCs, and HCs instead of CFCs (R12, R22, and R502. For this reason, the performance comparison of the new mixtures with CFC refrigerants has been done in the frame of this study. To compare the performance values, constant temperature method has been used. Thermodynamic properties of refrigerants that were used in the performance calculations have been taken from REFPROP 6.01. For this aim, new software has written in FORTRAN programing language using sub-programs of REFPROP, and all related calculations of performance have been achieved by this software.

  15. Thermodynamical analysis of a double acting reciprocating magnetic refrigerator

    International Nuclear Information System (INIS)

    Methods of adiabatic demagnetization were limited until very recently to one-shot operations or to power levels below 1 mW. This paper describes the results of a reciprocating magnetic refrigerator operating between 1.8 K and 4.2 K, with a useful power greater than 1 watt. In this type of machine there are various problems associated with heat transfer between magnetic substance and heat sources and inside the substance itself. The refrigerator described here overcomes some of these problems and achieves good efficiency

  16. Refrigeration and Air Conditioning Mechanic: Apprenticeship Course Outline. Apprenticeship and Industry Training. 1411.2

    Science.gov (United States)

    Alberta Advanced Education and Technology, 2011

    2011-01-01

    The graduate of the Refrigeration and Air Conditioning Mechanic apprenticeship training is a journeyman who will: (1) supervise, train and coach apprentices; (2) use and maintain hand and power tools to the standards of competency and safety required in the trade; (3) have a thorough knowledge of the principle components of refrigeration systems,…

  17. Performance of an irreversible quantum refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    He Ji-Zhou; Ouyang Wei-Pin; Wu Xin

    2006-01-01

    A new model of a quantum refrigeration cycle composed of two adiabatic and two isomagnetic field processes is established. The working substance in the cycle consists of many non-interacting spin-1/2 systems. The performance of the cycle is investigated, based on the quantum master equation and semi-group approach. The general expressions of several important performance parameters, such as the coefficient of performance, cooling rate, and power input, are given. It is found that the coefficient of performance of this cycle is in the closest analogy to that of the classical Carnot cycle. Furthermore, at high temperatures the optimal relations of the cooling rate and the maximum cooling rate are analysed in detail. Some performance characteristic curves of the cycle are plotted, such as the cooling rate versus the maximum ratio between high and low "temperatures" of the working substances, the maximum cooling rate versus the ratio between high and low "magnetic fields" and the "temperature" ratio between high and low reservoirs. The obtained results are further generalized and discussed, so that they may be directly applied to describing the performance of the quantum refrigerator using spin-J systems as the working substance. Finally, the optimum characteristics of the quantum Carnot and Ericsson refrigeration cycles are derived by analogy.

  18. 46 CFR 154.1720 - Indirect refrigeration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Indirect refrigeration. 154.1720 Section 154.1720... § 154.1720 Indirect refrigeration. A refrigeration system that is used to cool acetaldehyde, ethylene oxide, or methyl bromide, must be an indirect refrigeration system that does not use vapor compression....

  19. APEX Refrigeration Company Limited: Brand Identity Project

    OpenAIRE

    Dee, Peter

    2004-01-01

    APEX Refrigeration offers Refrigeration, Air Conditioning and Catering services across Ireland. Apex Refrigeration required a clean, bold and modern logo using cool colours and imagery. Peter Dee - Strategic Design and Marketing Consultant, was responsible for the design and development of the brand identity for the APEX Refrigeration Company which was used on business cards, letterhead, vehicle livery and e-Commerce website.

  20. Effect of surface microstructure and wettability on plasma protein adsorption to ZnO thin films prepared at different RF powers

    Energy Technology Data Exchange (ETDEWEB)

    Huang Zhanyun; Chen Min; Chen Dihu [State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou 510275 (China); Pan Shirong, E-mail: stscdh@mail.sysu.edu.c [Artificial Heart Lab, the 1st Affiliate Hospital of Sun Yat-Sen University, Guangzhou 510080 (China)

    2010-10-01

    In this paper, the adsorption behavior of plasma proteins on the surface of ZnO thin films prepared by radio frequency (RF) sputtering under different sputtering powers was studied. The microstructures and surface properties of the ZnO thin films were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible optical absorption spectroscopy and contact angle techniques. The results show that the ZnO thin films have better orientation of the (0 0 2) peak with increasing RF power, especially at around 160 W, and the optical band gap of the ZnO films varies from 3.2 to 3.4 eV. The contact angle test carried out by the sessile drop technique denoted a hydrophobic surface of the ZnO films, and the surface energy and adhesive work of the ZnO thin films decreased with increasing sputtering power. The amounts of human fibrinogen (HFG) and human serum albumin (HSA) adsorbing on the ZnO films and reference samples were determined by using enzyme-linked immunosorbent assay (ELISA). The results show that fewer plasma proteins and a smaller HFG/HSA ratio adsorb on the ZnO thin films' surface.

  1. Magnetic Refrigeration and the Magnetocaloric Effect

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  2. Cryogenic refrigeration apparatus

    Science.gov (United States)

    Crunkleton, James A.

    1992-01-01

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

  3. Characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption

    Science.gov (United States)

    Lu, Y.; Rostam-Abadi, M.; Chang, R.; Richardson, C.; Paradis, J.

    2007-01-01

    Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB-PC ashes) and three cyclone utility boilers burning either Powder River Basin (PRB) coals or PRB blends,(PRB-CYC ashes). As-received fly ash samples were mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury content, and Brunauer-Emmett-Teller (BET)-N2 surface areas of as-received fly ashes and their size fractions were measured. In addition, UBC particles were examined by scanning electron microscopy, high-resolution transmission microscopy, and thermogravimetry to obtain information on their surface morphology, structure, and oxidation reactivity. It was found that the UBC particles contained amorphous carbon, ribbon-shaped graphitic carbon, and highly ordered graphite structures. The mercury contents of the UBCs (Hg/UBC, in ppm) in raw ash samples were comparable to those of the UBC-enriched samples, indicating that mercury was mainly adsorbed on the UBC in fly ash. The UBC content decreased with a decreasing particle size range for all nine ashes. There was no correlation between the mercury and UBC contents of different size fractions of as-received ashes. The mercury content of the UBCs in each size fraction, however, generally increased with a decreasing particle size for the nine ashes. The mercury contents and surface areas of the UBCs in the PRB-CYC ashes were about 8 and 3 times higher than UBCs in the EB-PC ashes, respectively. It appeared that both the particle size and surface area of UBC could contribute to mercury capture. The particle size of the UBC in PRB-CYC ash and thus the external mass transfer was found to be the major factor impacting the mercury adsorption. Both the particle size and surface reactivity of the UBC in EB-PC ash, which generally had a lower carbon oxidation reactivity than the PRB

  4. Design and cost-benefit analysis of a mini thermo-acoustic refrigerator driver

    OpenAIRE

    Livvarcin, Omer.

    2000-01-01

    A miniature thermoacoustic refrigerator is being developed for the purpose of cooling integrated circuits below their failure temperature when used in hot environments. This thesis describes the development of an electrically powered acoustic driver that powers the thermoacoustic refrigerator. The driver utilizes a flexural tri-laminar piezoelectric disk to generate one to two Watts of acoustic power at 4 kHz in 15 bar of He-Kr gas mixture. This thesis also provides a cost analysis of the min...

  5. Early construction and operation of the highly contaminated water treatment system in Fukushima Daiichi Nuclear Power Station (3). A unique simulation code to evaluate time-dependent Cs adsorption/desorption behavior in column system

    International Nuclear Information System (INIS)

    A simulation code was developed to evaluate the performance of the cesium adsorption instrument operating in Fukushima Daiichi Nuclear Power Station. Since contaminated water contains seawater whose salinity is not constant, a new model was introduced to the conventional zeolite column simulation code to deal with the variable salinity of the seawater. Another feature of the cesium adsorption instrument is that it consists of several columns arranged in both series and parallel. The spent columns are replaced in a unique manner using a merry-go-round system. The code is designed by taking those factors into account. Consequently, it enables the evaluation of the performance characteristics of the cesium adsorption instrument, such as the time history of the decontamination factor, the cesium adsorption amount in each column, and the axial distribution of the adsorbed cesium in the spent columns. The simulation is conducted for different operation patterns and its results are given to Tokyo Electric Power Company (TEPCO) to support the optimization of the operation schedule. The code is also used to investigate the cause of some events that actually occurred in the operation of the cesium adsorption instrument. (author)

  6. 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, ...

  7. Quantum Refrigerator and the III-law of Thermodynamics

    CERN Document Server

    Levy, Amikam; Kosloff, Ronnie

    2012-01-01

    The rate of temperature decrease of a cooled quantum bath is studied as its temperature is reduced to the absolute zero. The III-law of thermodynamics is then quantified dynamically by evaluating the characteristic exponent {\\zeta} of the cooling process dT(t)/dt \\sim -T^{\\zeta} when approaching the absolute zero, T \\rightarrow 0. A continuous model of a quantum refrigerator is employed consisting of a working medium composed either by two coupled harmonic oscillators or two coupled 2-level systems. The refrigerator is a nonlinear device merging three currents from three heat baths: a cold bath to be cooled, a hot bath as an entropy sink, and a driving bath which is the source of cooling power. A heat driven refrigerator (absorption refrigerator) is compared to a power driven refrigerator. When optimized both cases lead to the same exponent {\\zeta}, showing a lack of dependence on the form of the working medium and the characteristics of the drivers. The characteristic exponent is therefore determined by the ...

  8. Experimental results on a low-temperature magnetic refrigerator

    International Nuclear Information System (INIS)

    A Carnot-cycle magnetic refrigerator has been designed, built, and tested in the temperature range of about 4 K to about 15 K. Gadolinium gallium garnet in the rim of a wheel is the refrigerant. The wheel rim rotates through a gap between two superconducting Helmholtz coils that produce a magnetic field of up to 6 T. Helium gas is used as the heat-transfer fluid in the hot and cold regions of the wheel. The refrigerator performance has been measured in an open-cycle flow system because no suitable low-temperature helium gas pumps were available for closed loop circulation of helium gas. Over one watt of cooling power with a temperature span of several degrees was achieved. At low frequencies the cooling power and temperature changes of the refrigerator match the entropytemperature data used in the design. Problems associated with friction and gas mixing limit the performance at frequencies above about 0.1 Hz. Separate friction measurements suggest that gas flow control is the dominant problem that needs to be solved before significant improvement in refrigerator operation can be expected. The present measured efficiency is about 20% of Carnot if the drive motor efficiency is ignored. With friction and other losses in the drive motor mechanism, the overall efficiency is about 1% of Carnot

  9. Adsorption characteristics and heat of adsorption measurements of R-134a on activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Bidyut B. [Mechanical Engineering Department, National University of Singapore, 10 Kent Ridge Crescent (Singapore); Habib, Khairul; Koyama, Shigeru [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga-shi, Fukuoka 816-8580 (Japan); El-Sharkawy, Ibrahim I. [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasuga-koen, Kasuga-shi, Fukuoka 816-8580 (Japan); Mechanical Power Engineering Department, Faculty of Engineering, Mansoura University, El-Mansoura (Egypt)

    2009-11-15

    This paper presents adsorption isotherms of R-134a (HFC-134a) on highly porous pitch based activated carbon (Maxsorb III) in the temperature range of 5-70 C and pressures up to 12 bar, using desorption method. The experimental data have been fitted with the Dubinin-Astakhov (D-A) isotherm equation. The adsorption isotherms of R-134a on Maxsorb III obtained from the present study are compared with the adsorption isotherm results of R-134a on similar type of adsorbents obtained by other researchers and they are found to be fairly consistent. The isosteric heat of adsorption of the assorted adsorbent-refrigerant pair has also been extracted from the present experimental data. (author)

  10. Adsorption properties of a natural zeolite-water pair for use in adsorption cooling cycles

    Energy Technology Data Exchange (ETDEWEB)

    Solmus, ismail; Yamali, Cemil; Baker, Derek; Caglar, Ahmet [Department of Mechanical Engineering, Middle East Technical University, 06531 Ankara (Turkey); Kaftanoglu, Bilgin [Department of Manufacturing Engineering, Atilim University, 06836 Ankara (Turkey)

    2010-06-15

    The equilibrium adsorption capacity of water on a natural zeolite has been experimentally determined at different zeolite temperatures and water vapor pressures for use in an adsorption cooling system. The Dubinin-Astakhov adsorption equilibrium model is fitted to experimental data with an acceptable error limit. Separate correlations are obtained for adsorption and desorption processes as well as a single correlation to model both processes. The isosteric heat of adsorption of water on zeolite has been calculated using the Clausius-Clapeyron equation as a function of adsorption capacity. The cyclic adsorption capacity swing for different condenser, evaporator and adsorbent temperatures is compared with that for the following adsorbent-refrigerant pairs: activated carbon-methanol; silica gel-water; and, zeolite 13X-water. Experimental results show that the maximum adsorption capacity of natural zeolite is nearly 0.12 kg{sub w}/kg{sub ad} for zeolite temperatures and water vapor pressures in the range 40-150 C and 0.87-7.38 kPa. (author)

  11. Study On Energy Conservation And Carbon Dioxide Emission Reduction Of Commercial Display Refrigerator Of Supermarket Utilizing The Exhaust Heat From The Novel Environment-Friendly Dispersed Power

    OpenAIRE

    Shikano, Tatsuya; Bae, Sangchul; Katsuta, Masafumi; Anamizu, Tomohiro

    2014-01-01

    Since the nuclear disaster was caused by the Great East Japan Earthquake in 2011, Japanese energy generation system has been expected to prioritize safety and trustworthiness. To meet this requirement, distributed power supply systems, such as gas engine, fuel cell, photovoltaic system, and solar heat, are considered to be one of solutions. By producing electricity, these systems generate thermal energy as a byproduct, and by using exhaust heat as thermal energy, we can help to minimize the C...

  12. High Efficiency Refrigeration Process Project

    Data.gov (United States)

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

  13. Thermal Power Of The TS-300B Refrigerator in the Aspects of Statistical Research / Moc Cieplna Chłodziarki TS-300B W Aspekcie Badań Statystycznych

    Science.gov (United States)

    Nowak, Bernard; Łuczak, Rafał

    2015-09-01

    The article discusses the improvement of thermal working conditions in underground mine workings, using local refrigeration systems. It considers the efficiency of air cooling with direct action air compression refrigerator of the TS-300B type. As a result of a failure to meet the required operating conditions of the aforementioned air cooling system, frequently there are discrepancies between the predicted (and thus the expected) effects of its work and the reality. Therefore, to improve the operating efficiency of this system, in terms of effective use of the evaporator cooling capacity, quality criteria were developed, which are easy in practical application. They were obtained in the form of statistical models, describing the effect of independent variables, i.e. the parameters of the inlet air to the evaporator (temperature, humidity and volumetric flow rate), as well as the parameters of the water cooling the condenser (temperature and volumetric flow rate), on the thermal power of air cooler, treated as the dependent variable. Statistical equations describing the performance of the analyzed air cooling system were determined, based on the linear and nonlinear multiple regression. The obtained functions were modified by changing the values of the coefficients in the case of linear regression, and of the coefficients and exponents in the case of non-linear regression, with the independent variables. As a result, functions were obtained, which were more convenient in practical applications. Using classical statistics methods, the quality of fitting the regression function to the experimental data was evaluated. Also, the values of the evaporator thermal power of the refrigerator, which were obtained on the basis of the measured air parameters, were compared with the calculated ones, by using the obtained regression functions. These statistical models were built on the basis of the results of measurements in different operating conditions of the TS-300B

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-01

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

  15. Analysis of the use of adsorption processes in trigeneration systems

    Science.gov (United States)

    Grzebielec, Andrzej; Rusowicz, Artur

    2013-12-01

    The trigeneration systems for production of cold use sorption refrigeration machines: absorption and adsorption types. Absorption systems are characterized namely by better cooling coefficient of performance, while the adsorptive systems are characterized by the ability to operate at lower temperatures. The driving heat source temperature can be as low as 60-70 °C. Such temperature of the driving heat source allows to use them in district heating systems. The article focuses on the presentation of the research results on the adsorption devices designed to work in trigeneration systems.

  16. 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.

  17. Four-level refrigerator driven by photons.

    Science.gov (United States)

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

    2015-05-01

    We propose a quantum absorption refrigerator driven by photons. The model uses a four-level system as its working substance and couples simultaneously to hot, cold, and solar heat reservoirs. Explicit expressions for the cooling power Q̇(c) and coefficient of performance (COP) η(COP) are derived, with the purpose of revealing and optimizing the performance of the device. Our model runs most efficiently under the tight coupling condition, and it is consistent with the third law of thermodynamics in the limit T→0. PMID:26066099

  18. Four-level refrigerator driven by photons

    Science.gov (United States)

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

    2015-05-01

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

  19. Radio-frequency single-electron refrigerator.

    Science.gov (United States)

    Pekola, Jukka P; Giazotto, Francesco; Saira, Olli-Pentti

    2007-01-19

    We propose a cyclic refrigeration principle based on mesoscopic electron transport. Synchronous sequential tunneling of electrons in a Coulomb-blockaded device, a normal metal-superconductor single-electron box, results in a cooling power of approximately k(B)T x f at temperature T over a wide range of cycle frequencies f. Electrostatic work, done by the gate voltage source, removes heat from the Coulomb island with an efficiency of approximately k(B)T/Delta, where Delta is the superconducting gap parameter. The performance is not affected significantly by nonidealities, for instance by offset charges. We propose ways of characterizing the system and of its practical implementation. PMID:17358719

  20. Rare Earths and Magnetic Refrigeration

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Magnetic refrigeration is a revolutionary, efficient, environmentally friendly cooling technology, which is on the threshold of commercialization. The magnetic rare earth materials are utilized as the magnetic refrigerants in most cooling devices, and for many cooling application the Nd2Fe14B permanent magnets are employed as the source of the magnetic field. The status of the near room temperature magnetic cooling was reviewed.

  1. Application of solar refrigeration technology

    OpenAIRE

    Liu, Yang

    2015-01-01

    With the continuous progress and development, people's living standards increase. Air conditioners, refrigerators and other electrical products are more popular in average families. In summer, people enjoy the fresh air, while electricity costs are staggering. Can I create non-consumption of energy, but also can bring achieve cooling? The answer is yes, now researchers are developing a device using solar energy to refrigeration, to be put on the market, the device not only consumes energy but...

  2. Night Wind - Deliverable D.3.2 main simulation report; Grid architecture for wind power production with energy storage through load shifting in refrigerated warehouses

    Energy Technology Data Exchange (ETDEWEB)

    Cronin, Tom; Bindner, Henrik; Zong, Yi

    2008-11-15

    This report represents Deliverable D.3.2 of Work Package 3 in the Night Wind project. The aim of this Work Package was to simulate a cold store (or number of cold stores) within a power system where there is a high degree of wind power penetration. The Night Wind Control System, developed as part of Work Package 5, was to be integrated into the simulations so that the wind power could be 'stored' in the cold store with maximum benefit to the electrical network, utility or cold store owner. To this end, the following have been accomplished: 1) The Night Wind concept has been described in terms of demand side management. 2) Input requirements and data have been specified and collected. Measured data from the existing cold store facility of Partner Logistics has been analysed. 3) Component models for the simulations (including the cold store model itself) have been developed for the simulation platform, IPSYS. 4) The Night Wind Control System (NWCS) from Work Package 5 has been developed so that it finishes computations within two minutes. 5) Controllers including the NWCS) have been operated with the cold store model within IPSYS. 6) Simulations have been performed with the cold store model and an increasing penetration of wind power. This report presents the results of the work undertaken in Work Package 3 which would have benefited from the additional time requested at the project meeting in March 2008, however, this extension of time was not granted. Nevertheless, the work that was possible is considered significantly complete, although it is acknowledged that there has been a delay in the presentation of this report. It should be noted that it was not possible to address the new aspects of Task 3.7 'Verification of simulation results' as there was no implementation of the night wind concept at the demonstration site (Task 7). Verification of the simulation of the present system has, naturally, been carried out and described in this report. (ln)

  3. Combined heat and power generation with exhaust-heated two-stage absorption refrigerator. Performance of a pilot installation with a refrigeration capacity of 350 kW; Kraft-Waerme-Kaelte-Kopplung mit Abgas-Beheizter zweistufiger Absorptionskaeltemaschine. Betriebserfahrungen einer Pilotinstallation mit 350 kW Kaelteleistung

    Energy Technology Data Exchange (ETDEWEB)

    Plura, S.; Baumeister, D.; Koeberle, T.; Radspieler, M.; Schweigler, C. [Bayerisches Zentrum fuer Angewandte Energieforschung e.V. (ZAE Bayern), Garching (Germany)

    2007-07-01

    A new system concept for higher efficiency of cogeneration systems is developed in which a cogeneration unit is combined with a two-stage absorption refrigerator, and the waste heat of the cogeneration unit is directly passed on into the regenerator of the absorption refrigerator. The higher temperature level of the waste heat makes it possible to use a two-stage absorption cycle for higher energy efficiency. For simultaneous utilisation of low-temperature heat, the two-stage cycle is combined with a one-stage cycle for additional heat supply at a lower temperature level so that the exhaust of a typical cogeneration unit will be cooled to about 120 degC. At the same time, further waste heat of the cogeneration unit will be transferred to the heat pump via a hot water circuit. This concept with a combined single-stage and two-stage absorption circuit is referred to as a double-effect/single-effect circuit. The new system is used for energy supply in a spa, where the two-stage absorption refrigerator cools the water used for swimming pool cleaning with a refrigerating capacity of 350 kW and provides low-temperature heat for swimming pool heating with a capacity of 700 kW. (orig.)

  4. Load management for refrigeration systems: Potentials and barriers

    Energy Technology Data Exchange (ETDEWEB)

    Grein, Arne, E-mail: a.grein@tu-berlin.de [University of Technology Berlin, Institute for Energy Technology, Department of Energy Systems, Einsteinufer 25 (TA8), 10587 Berlin (Germany); Pehnt, Martin [Institute for Energy and Environmental Research Heidelberg (ifeu), Wilckensstr. 3, 69120 Heidelberg (Germany)

    2011-09-15

    As a strategy to deal with the increasing intermittent input of renewable energy sources in Germany, the adaptation of power consumption is complementary to power-plant regulation, grid expansion and physical energy storage. One demand sector that promises strong returns for load management efforts is cooling and refrigeration. In these processes, thermal inertia provides a temporal buffer for shifting and adjusting the power consumption of cooling systems. We have conducted an empirical investigation to obtain a detailed and time-resolved bottom-up analysis of load management for refrigeration systems in the city of Mannheim, Germany. We have extrapolated our results to general conditions in Germany. Several barriers inhibit the rapid adoption of load management strategies for cooling systems, including informational barriers, strict compliance with legal cooling requirements, liability issues, lack of technical experience, an inadequate rate of return and organizational barriers. Small commercial applications of refrigeration in the food-retailing and cold storage in hotels and restaurants are particularly promising starting points for intelligent load management. When our results are applied to Germany, suitable sectors for load management have theoretical and achievable potential values of 4.2 and 2.8 GW, respectively, amounting to about 4-6% of the maximum power demand in Germany. - Highlights: > Potential and barriers for implementation of load shifting for refrigeration. > Empirical investigation for time-resolved bottom-up analysis in Mannheim, Germany. > Suitable sectors and further recommendations for introducing load management.> Extrapolation of results from local to national level.

  5. Performance of an auto refrigerant cascade refrigerator operating in liquid refrigerant supply (LRS) mode with different cascade heat exchangers

    Science.gov (United States)

    Gurudath Nayak, H.; Venkatarathnam, G.

    2010-11-01

    Auto refrigerant cascade (ARC) refrigerators operating with zeotropic mixtures provide refrigeration at temperatures less than 173 K (-100 °C) using a single compressor. Different authors have suggested different cascade heat exchangers for ARC refrigerators. There is no study in literature that suggests at what temperature ranges one, two or three cascade heat exchangers are necessary. In this paper the performance of an ARC refrigerator operating in the liquid refrigerant supply mode and operating with optimized hydrocarbon mixtures and different cascade heat exchangers is studied. The optimum number of cascade heat exchangers (stages) to be used for different operating temperatures is suggested.

  6. Optimal performance of a thermoelectric refrigerator

    International Nuclear Information System (INIS)

    The optimal performance of a thermoelectric device used as a refrigerator is discussed by using the rate of refrigeration and the coefficient of performance of the refrigerator under the influence of three main irreversibilities which are heat conduction, heat leak, and Joule heat. The coefficient of performance and the operating current of the refrigerator at the maximum rate of refrigeration and the operating current of the refrigerator at the maximum coefficient of performance. The reasonable ranges of the coefficient of performance, the rate of refrigeration, and the operating current for the refrigerator are determined. The results obtained here have more instructive meaning than those of non-equilibrium thermodynamics for the optimal design and operation of practical thermoelectric refrigerators. copyright 1995 American Institute of Physics

  7. Recent developments on domestic refrigerator -- a review

    Energy Technology Data Exchange (ETDEWEB)

    Tiwari, A.; Gupta, R.C.

    2011-07-01

    This review paper represents the recent developments in domestic refrigerator. Refrigerator performance is increased by using different refrigerants. Basic components have been optimized to enhance the COP of refrigerator. Eco friendly refrigerants like R-404a,R-407c,R-410a,R-152a are developed which provide almost the same performance as R-12 and R-134a. This review paper also presents the experimental and theoretical studies of the HFC, HC and mixture of both HC and HFC refrigerants. With the help of these studies, we observe that the HC, HFC and their mixture are best alternative for halogenated refrigerant like R-12, R-22, R-717 etc. HC, HFC and their mixture refrigerants provide less Ozone Depletion Potential and Global Warming Potential than the halogenated refrigerant and better miscibility with mineral oil and POE oil.

  8. Model based control of refrigeration systems

    Energy Technology Data Exchange (ETDEWEB)

    Sloth Larsen, L.F.

    2005-11-15

    The subject for this Ph.D. thesis is model based control of refrigeration systems. Model based control covers a variety of different types of controls, that incorporates mathematical models. In this thesis the main subject therefore has been restricted to deal with system optimizing control. The optimizing control is divided into two layers, where the system oriented top layers deals with set-point optimizing control and the lower layer deals with dynamical optimizing control in the subsystems. The thesis has two main contributions, i.e. a novel approach for set-point optimization and a novel approach for desynchronization based on dynamical optimization. The focus in the development of the proposed set-point optimizing control has been on deriving a simple and general method, that with ease can be applied on various compositions of the same class of systems, such as refrigeration systems. The method is based on a set of parameter depended static equations describing the considered process. By adapting the parameters to the given process, predict the steady state and computing a steady state gradient of the cost function, the process can be driven continuously towards zero gradient, i.e. the optimum (if the cost function is convex). The method furthermore deals with system constrains by introducing barrier functions, hereby the best possible performance taking the given constrains in to account can be obtained, e.g. under extreme operational conditions. The proposed method has been applied on a test refrigeration system, placed at Aalborg University, for minimization of the energy consumption. Here it was proved that by using general static parameter depended system equations it was possible drive the set-points close to the optimum and thus reduce the power consumption with up to 20%. In the dynamical optimizing layer the idea is to optimize the operation of the subsystem or the groupings of subsystems, that limits the obtainable system performance. In systems

  9. Comportamento pós-colheita de caquis cv. Fuyu, através da atmosfera modificada passiva e da adsorção de etileno, armazenados sob refrigeração Postharvest behavior of persimmons cv. Fuyu through passive modified atmosphere and ethylene adsorption stored under refrigeration

    Directory of Open Access Journals (Sweden)

    Leandro Camargo Neves

    2006-12-01

    Full Text Available O trabalho foi realizado no Departamento de Ciência e Tecnologia Agroindustrial, da UFPel/Pelotas, com o objetivo de avaliar a utilização de embalagens de polietileno de baixa densidade (PEBD e do adsorvedor de etileno em caquis cv. Fuyu. Na safra de 2000-2001, os frutos foram armazenados a granel, em embalagens de PEBD de 0,022 mm contendo doze e 40 frutos e em embalagens de PEBD de 0,033 mm contendo doze frutos, sendo que apenas metade das embalagens possuía o sachê adsorvedor de etileno. De acordo com as variáveis analisadas (distúrbios fisiológicos, concentração/produção de CO2 e etileno, os frutos acondicionados nas embalagens de 0,022 mm contendo doze frutos, com e sem o adsorvedor, apresentavam-se em estádio menos avançado de amadurecimento e com qualidade superior aos demais tratamentos. Já na safra de 2001 - 2002, sob os mesmos parâmetros avaliados no ano anterior, foram testados o armazenamento a granel e o armazenamento em embalagens de PEBD de 0,022 mm, contendo doze, dezoito e 24 frutos, também com e sem a utilização de sachê adsorvedor de etileno. Após 90 dias de armazenamento refrigerado (AR, mais os cinco dias de simulação de comercialização, os frutos acondicionados nas embalagens de 0,022 mm, contendo doze e dezoito frutos, independentemente do sistema de adsorção de etileno, apresentaram os melhores resultados em todas as variáveis testadas.The experiments were carried out at the Science and Technology Agroindustry Department of UFPel/Pelotas, with the objective to improve the use of polyethylene packing of low density (PPLD and the adsorption of ethylene, in Fuyu persimmons. During the season of 00/01, the fruits were stored without packing, in 0,022 mm PPLD packing with capacity for 12 or 40 fruits and in 0,033 mm PPLD packing with capacity for 12 units. Except for the control treatment, all the other treatments were combined with (50% or without (50% ethylene absorption. According to the analyzed

  10. 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.

  11. An Adsorption Equilibria Model for Steady State Analysis

    KAUST Repository

    Ismail, Azhar Bin

    2016-02-29

    The investigation of adsorption isotherms is a prime factor in the ongoing development of adsorption cycles for a spectrum of advanced, thermally-driven engineering applications, including refrigeration, natural gas storage, and desalination processes. In this work, a novel semi-empirical mathematical model has been derived that significantly enhances the prediction of the steady state uptake in adsorbent surfaces. This model, a combination of classical Langmuir and a novel modern adsorption isotherm equation, allows for a higher degree of regression of both energetically homogenous and heterogeneous adsorbent surfaces compared to several isolated classical and modern isotherm models, and has the ability to regress isotherms for all six types under the IUPAC classification. Using a unified thermodynamic framework, a single asymmetrical energy distribution function (EDF) has also been proposed that directly relates the mathematical model to the adsorption isotherm types. This fits well with the statistical rate theory approach and offers mechanistic insights into adsorption isotherms.

  12. Modelling of a refrigerating system coupled with a refrigerated room

    Science.gov (United States)

    Wang, Hongwei

    1991-08-01

    The development of a set of comprehensive computer models to simulate and analyze both steady state and non steady state behavior of a refrigerating system coupled with a refrigerated room is described. The refrigerating system is a single stage vapor compression system consisting of four basic elements: a reciprocating piston compressor, a dry expansion evaporator (or cooler), a shell and tube watercooled condensor and a thermostatic expansion valve. To validate the computer models, a test plant on which steady state and dynamic measurements were carried out, was set up. Experiments to determine several empirical constants encountered in the models were done, and the simulation results were compared with a series of measurements within a wide range of operation conditions. The validated models were applied to the prediction of the air distributions in a cold store and the study of a system with different capacity control systems, proving the capability and reliability of the models.

  13. An autonomous dilution micro refrigerator

    International Nuclear Information System (INIS)

    In the dilution refrigerator3He circulates due to its condensation in a vessel with the temperature of 0.35-0.4K. The latter is cooled by the pumping of 3He from another bath by means of a sorption pump. A temperature 12 hours. The sample holder is placed in an upper part of the refrigerator and is connected with a mixer by a copper heat conductor. They are surrounded by screens at temperatures 0.4, 4.2 and ∼100K. The low temperature part is tied to the 0.4 K screen and centered by a polymer threads. A heat flux from the 0.4 K screen to the mixer is less than 0.1 μW. Inner volumes are filled with 0.2 mol of 4He, 0.1 mol of 3He and 0.05 mol of a mixture 40%3He+60%4He respectively. These gases remain all time inside the apparatus. The refrigerator is working when inserted in a 35 l transport cryostat with a liquid helium and operate during 5-6 days. The refrigerator is designed to cool down low temperature detectors or samples in experiments that do not require a high refrigerating capacity.

  14. An autonomous dilution micro refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, V S [P. L. Kapitza Institute for Physical Problems, Russian Academy of Sciences, ul. Kosygina 2, Moscow 117334 (Russian Federation)], E-mail: edelman@kapitza.ras.ru

    2009-02-01

    In the dilution refrigerator{sup 3}He circulates due to its condensation in a vessel with the temperature of 0.35-0.4K. The latter is cooled by the pumping of {sup 3}He from another bath by means of a sorption pump. A temperature <0.1 K is maintained for >12 hours. The sample holder is placed in an upper part of the refrigerator and is connected with a mixer by a copper heat conductor. They are surrounded by screens at temperatures 0.4, 4.2 and {approx}100K. The low temperature part is tied to the 0.4 K screen and centered by a polymer threads. A heat flux from the 0.4 K screen to the mixer is less than 0.1 {mu}W. Inner volumes are filled with 0.2 mol of {sup 4}He, 0.1 mol of {sup 3}He and 0.05 mol of a mixture 40%{sup 3}He+60%{sup 4}He respectively. These gases remain all time inside the apparatus. The refrigerator is working when inserted in a 35 l transport cryostat with a liquid helium and operate during 5-6 days. The refrigerator is designed to cool down low temperature detectors or samples in experiments that do not require a high refrigerating capacity.

  15. 10 CFR 431.62 - Definitions concerning commercial refrigerators, freezers and refrigerator-freezers.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial refrigerators, freezers and refrigerator-freezers. 431.62 Section 431.62 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY EFFICIENCY PROGRAM FOR CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Refrigerators, Freezers and Refrigerator-Freezers §...

  16. 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, ...

  17. Refrigeration system having dual suction port compressor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guolian

    2016-01-05

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

  18. Experimental Investigation on an Absorption Refrigerator Driven by Solar Cells

    OpenAIRE

    Zi-Jie Chien; Hung-Pin Cho; Ching-Song Jwo; Chao-Chun Chien; Sih-Li Chen; Yen-Lin Chen

    2013-01-01

    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 ambi...

  19. Performance of the Oxford miniature Stirling cycle refrigerator

    Science.gov (United States)

    Bradshaw, T. W.; Delderfield, J.; Werrett, S. T.; Davey, G.

    The 'Oxford Cryocooler' miniature Stirling cycle cooler, a 5-kg mass split-cycle refrigerator developed for use aboard spacecraft, had as its design performance goal the production of 0.5 W of cooling power at 80 K for 30 W of electrical input power. The goal has actually been exceeded, prompting the present discussion of the compressor power budget and displacer losses. Attention is given to graphs of the cold-end temperature vs. compressor input power and cooling power. The cooler is to be used on the Improved Stratospheric and Mesospheric Sounder experiment of the Upper Atmosphere Research Satellite.

  20. Automotive exhaust gas flow control for an ammonia–water absorption refrigeration system

    International Nuclear Information System (INIS)

    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

  1. Load forecasting for supermarket refrigeration

    DEFF Research Database (Denmark)

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

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

  2. Reduction of Thermal Energy Loss in Cyclic Operation of Refrigeration Cycle

    Science.gov (United States)

    Gommori, Masahiko; Kogure, Hiroshi; Hara, Toshitsugu

    Investigation of thermal energy loss in cyclic operation of refrigeration cycle in a refrigerator-freezer were made. The energy loss was found to consist of three parts ; hot gas-refrigerant entering loss, cooling lag loss, and evaporator superheat loss. Hot gas-refrigerant entering loss is occured when high temperature gaseous refrigerant in a condenser flows into an evaporator to heat up the refrigerant in it. Main results are as follows ; 1) Hot gas-refrigerant entering loss, which was the most dominant, was found to be from 7.6 to 12.3% (for reciprocationg compressor) and from 11.9 to 17.4% (for rotary compressor) of the cooling load, respectively. 2) The thermal energy loss was confirmed to be able to be reduced when hot gas-refrigerant was restricted to flow in the evaporator with control valves. It follows to reduce electrical power consumption by 10 and 15%, in the case of reciprocating compressor and of rotary compressor, respectively. 3) Cycle frequency was made to be optimized theoretically and experimentally in the case of with and without valves.

  3. A flexible numerical model to study an active magnetic refrigerator for near room temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Aprea, Ciro; Maiorino, Angelo [Department of Mechanical Engineering, University of Salerno, Via Ponte Don Melillo 1, 84084 Fisciano (Salerno) (Italy)

    2010-08-15

    Magnetic refrigeration is an emerging technology based on the magnetocaloric effect in solid-state refrigerants. This technology offers a smaller global environmental impact than the refrigeration obtained by means of the classical vapor compression machines operating with fluids such as HFCs. The Active Magnetic Regenerative Refrigeration (AMRR) is currently the most studied ant tested magnetic cycle. It combines the regenerative properties of a high specific heat solid porous matrix with the ability of performing thermo-magnetic cycles thanks to the magnetocaloric property of the refrigerant; while a fluid pulsing through the regenerator works as a heat transfer medium. An active magnetic regenerator can provide larger temperature spans making up for the local small temperature variation of the refrigerant. In the present paper, a practical model for predicting the performance and efficiency of an AMRR cycle has been developed. The model evaluates both the refrigerant properties and the entire cycle of an AMR operating in conformity with a Brayton regenerative cycle. The magnetocaloric material of choice is gadolinium, while the heat transfer medium is liquid water. With this model can be predicted the refrigeration capacity, the power consumption and consequently the Coefficient of Performance. The results show a greater COP when compared to a classical vapor compression plant working between the same temperature levels. (author)

  4. Development of a Low-Cost Refrigerator for Fruits and Vegetables Storage

    Directory of Open Access Journals (Sweden)

    M.O. Sunmonu

    2014-01-01

    Full Text Available A low cost refrigerator was developed and its performance evaluated by determining the cooling efficiency. The refrigerator consists of an evaporator, ccompressor, dryer, filter, fan, condenser, capillary tube and working fluid (R12 Gas. The main source of power is electricity. The refrigerator works on the basic principle of vapour compression refrigeration cycle and was designed to accommodate about 0.02 metric tonnes (20kg of any fresh fruits such as oranges, apples and mangoes. The capacity of the cooling chamber is 97370cm3. During the test period with fresh apples for a period of 9 hours constant supply of electricity. An average temperature of 3.640C and 26.890C were recorded for the refrigerator and the ambient respectively. Also an average relative humidity of 92.14% and 39.09% were recorded for the refrigerator and the ambient respectively. The average cooling efficiency of the refrigerator is 86.5%. The material cost for the refrigerator is about USD 97.

  5. A flexible numerical model to study an active magnetic refrigerator for near room temperature applications

    International Nuclear Information System (INIS)

    Magnetic refrigeration is an emerging technology based on the magnetocaloric effect in solid-state refrigerants. This technology offers a smaller global environmental impact than the refrigeration obtained by means of the classical vapor compression machines operating with fluids such as HFCs. The Active Magnetic Regenerative Refrigeration (AMRR) is currently the most studied ant tested magnetic cycle. It combines the regenerative properties of a high specific heat solid porous matrix with the ability of performing thermo-magnetic cycles thanks to the magnetocaloric property of the refrigerant; while a fluid pulsing through the regenerator works as a heat transfer medium. An active magnetic regenerator can provide larger temperature spans making up for the local small temperature variation of the refrigerant. In the present paper, a practical model for predicting the performance and efficiency of an AMRR cycle has been developed. The model evaluates both the refrigerant properties and the entire cycle of an AMR operating in conformity with a Brayton regenerative cycle. The magnetocaloric material of choice is gadolinium, while the heat transfer medium is liquid water. With this model can be predicted the refrigeration capacity, the power consumption and consequently the Coefficient of Performance. The results show a greater COP when compared to a classical vapor compression plant working between the same temperature levels.

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

    International Nuclear Information System (INIS)

    Highlights: • Application of supermarket energy control system model. • Heat recovery from CO2 refrigeration system in supermarket space conditioning. • Effect of pressure controls of CO2 refrigeration system on heat recovery potentials. • Control optimization of CO2 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 CO2 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. CO2 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-CO2 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 CO2 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

  7. Towards Less Refrigeration-dependent Home Practices

    OpenAIRE

    2011-01-01

    The thesis focuses on the energy intensity in the household food refrigeration, and it seeks to analyze the way refrigeration is perceived by Norwegians in a historical perspective. The practice theory is applied in the study to interpret how individuals, cultural contexts and people’s routinized practices have contributed to the changing household reliance on food refrigeration. The findings show that it is the household demands for energy services rather than the refrigerating technology it...

  8. Solar heat utilization for adsorption cooling device

    Directory of Open Access Journals (Sweden)

    Malcho Milan

    2012-04-01

    Full Text Available This article deals with possibility of solar system connection with adsorption cooling system. Waste heat from solar collectors in summer is possible to utilize in adsorption cooling systems, which desorption temperatures have to be lower than temperature of heat transport medium operation temperature. For verification of work of this system was constructed on the Department of power engineering on University of Zilina solar adsorption cooling device.

  9. Solar heat utilization for adsorption cooling device

    OpenAIRE

    Malcho Milan; Patsch Marek; Pilát Peter

    2012-01-01

    This article deals with possibility of solar system connection with adsorption cooling system. Waste heat from solar collectors in summer is possible to utilize in adsorption cooling systems, which desorption temperatures have to be lower than temperature of heat transport medium operation temperature. For verification of work of this system was constructed on the Department of power engineering on University of Zilina solar adsorption cooling device.

  10. Load forecasting of supermarket refrigeration

    DEFF Research Database (Denmark)

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

    2016-01-01

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

  11. Heat driven refrigeration cycle at low temperatures

    Institute of Scientific and Technical Information of China (English)

    HE Yijian; HONG Ronghua; CHEN Guangming

    2005-01-01

    Absorption refrigeration cycle can be driven by low-grade thermal energy, such as solar energy, geothermal energy and waste heat. It is beneficial to save energy and protect environment. However, the applications of traditional absorption refrigeration cycle are greatly restricted because they cannot achieve low refrigeration temperature. A new absorption refrigeration cycle is investigated in this paper, which is driven by low-grade energy and can get deep low refrigeration temperature. The mixture refrigerant R23+R134a and an absorbent DMF are used as its working fluid. The theoretical results indicate that the new cycle can achieve -62℃ refrigeration temperature when the generation temperature is only 160℃. This refrigeration temperature is much lower than that obtained by traditional absorption refrigeration cycle. Refrigeration temperature of -47.3℃ has been successfully achieved by experiment for this new cycle at the generation temperature of 157℃, which is the lowest temperature obtained by absorption refrigeration system reported in the literature up to now. The theoretical and experimental results prove that new cycle can achieve rather low refrigeration temperature.

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

    International Nuclear Information System (INIS)

    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)

  13. A Cooling System for an Automobile Based on Vapour Absorption Refrigeration Cycle Using Waste Heat of an Engine.

    Directory of Open Access Journals (Sweden)

    Satish K. Maurya

    2014-03-01

    Full Text Available Now a days the air conditioning system of cars is mainly uses “Vapour Compression Refrigerant System” (VCRS which absorbs and removes heat from the interior of the car that is the space to be cooled and rejects the heat to atmosphere. In vapour compression refrigerant system, the system utilizes power from engine shaft as the input power to drive the compressor of the refrigeration system, hence the engine has to produce extra work to run the compressor of the refrigerating system utilizing extra amount of fuel. This loss of power of the vehicle for refrigeration can be neglected by utilizing another refrigeration system i.e. a “Vapour Absorption Refrigerant System”. As well known thing about VAS that these machines required low grade energy for operation. Hence in such types of system, a physicochemical process replaces the mechanical process of the Vapour Compression Refrigerant System by using energy in the form of heat rather than mechanical work. This heat obtained from the exhaust of high power internal combustion engines.

  14. Adsorption and wetting.

    NARCIS (Netherlands)

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption

  15. High Efficiency, Low Emission Refrigeration System

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center; Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Building Technologies Research and Integration Center

    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

  16. Experimental research on LiBr refrigeration - Heat pump system applied in CCHP system

    International Nuclear Information System (INIS)

    A new heat recovery technique for a LiBr refrigeration-heat pump system applied in CCHP(Combined Cooling, Heating and Power system) system is proposed in this paper. The system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. Experimental research on the operating characteristics of the compound system is carried out and the obtained conclusions are as follows: The LiBr refrigeration-heat pump system is able to perform stably and flexibly. The heat pump system has a relative large coefficient of performance (COPP) which can be as high as 6.13. When the outlet temperature of the demineralized water is 67.8 oC, the CCHP system brings 26.6% decrease in primary energy rate consumption compared with the combined heat and power production system (CHP) plus electricity-driven refrigeration. It is suggested that heat pumps should be used in CCHP system to heat the demineralized water of the boiler by recovering the exhaust heat of the LiBr refrigeration system. - Highlights: → LiBr refrigeration-heat pump system applied in CCHP system is proposed. → This system can recover the heat of the LiBr refrigeration cooling water to heat the demineralized water of the boiler. → Using heat pump to recover exhaust heat can increase the energy efficiency of the whole CCHP.

  17. Control of the Tevatron Satellite Refrigeration system

    International Nuclear Information System (INIS)

    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

  18. Refrigerator COP with thermal storage

    International Nuclear Information System (INIS)

    Due to the extreme necessity to diversify renewable energy sources, the search for energy recycling methods through the utilization of thermal losses from equipment has become fundamental. Thus, these losses can be used as a new source of energy for water heating and storage in domestic hot water storage tanks (DHWST). For this reason, the construction of an experimental apparatus with a cylindrical thermal storage tank is proposed, in which the objective of the study will be a survey of the coefficient of performance concerning conventional and modified refrigerators, as well as to perform an analysis of hot water, through the thermal stratification technique using a refrigerator with a modified condenser. The collected thermal loss, as per the thermosyphon principle, will be stored as thermal energy. The results showed the full operation of the modified refrigeration system, which did not reveal significant alterations in thermodynamic behavior after the modifications made on the condenser. The dynamic behavior of the thermal distribution was observed through the thermal stratification effect and temperature evolution in terms of time, showing greater variability of the modified refrigerator generating more thermal comfort to users in addition to providing domestic hot water.

  19. 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.

  20. Low-temperature magnetic refrigerator

    International Nuclear Information System (INIS)

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

  1. Magnetic refrigerator for hydrogen liquefaction

    International Nuclear Information System (INIS)

    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.

  2. A dilution refrigerator using the pulse tube and GM hybrid cryocooler for neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Koike, Y.; Morii, Y. [Japan Atomic Energy Research Institute, Ibaraki (Japan) ; Igarashi, T.; Kubota, M. [University of Tokyo (Japan). Institute for Solid State Physics; Hiresaki, Y.; Tanida, K. [Susuki Shokan Company Ltd., Saitama (Japan)

    1999-07-01

    A liquid-He-free dilution refrigerator, 'mK Cryocooler', for neutron scattering research is constructed. It obtained the lowest sample temperature of 41mK in the neutron beam experiment. The mK Cryocooler has a pulse tube cryocooler as the 4 K stage and a Joule-Thomson type dilution refrigerator as the mK stage. The mK Cryocooler is a compact and movable refrigerator for neutron scattering research. The obtained cooling power at 100 mK was about 43 {mu}W when the lowest temperature was 49 mK. (author)

  3. Application of magnetic refrigeration and its assessment

    International Nuclear Information System (INIS)

    Magnetic refrigeration has the potential to replace conventional refrigeration-with often problematic refrigerants-in several niche markets or even some main markets of the refrigeration domain. Based on this insight, for the Swiss Federal Office of Energy a list of almost all existing refrigeration technologies was worked out. Then an evaluation how good magnetic refrigeration applies to each of these technologies was performed. For this purpose a calculation tool to determine the coefficient of performance (COP) and the exergy efficiency as a function of the magnetic field strength and the rotation frequency of a rotary-type magnetic refrigerator was developed. The evaluation clearly shows that some application domains are more ideal for a replacement of conventional refrigerators by their magnetic counterparts than others. In the pre-study, four good examples were chosen for a more comprehensive investigation and working out of more detailed results. In this article, the calculation method is briefly described. COP values and exergy efficiencies of one very suitable technology, namely the magnetic household refrigerator, are presented for different operation conditions. Summarizing, it is stated that magnetic refrigeration is a serious environmentally benign alternative to some conventional cooling, refrigeration and air-conditioning technologies

  4. Environment-friendly refrigeration - Switzerland moves forward

    International Nuclear Information System (INIS)

    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

  5. Development of a Battery-Free Solar Refrigerator

    Science.gov (United States)

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

    2000-01-01

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

  6. 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. Ele...... 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....

  7. Study of change of refrigerant R22 in chiller units by simulation in EcosimPro

    International Nuclear Information System (INIS)

    On January 1, 2010 is forbidden to hold any stock of virgin R22 refrigerant and it is also forbidden to use virgin R22 refrigerant for the service and maintenance of equipment under the new European Community Regulation 20137/2000. On January 1, 2015 and stock of R22, even if reclaimed or recycled, will be illegal to hold. In accordance with the European Community regulation, Cofrentes Nuclear Power Plant begins the R22 retrofit. (Author)

  8. Performance test of the HERA 3 x 6500 w helium refrigeration plant

    International Nuclear Information System (INIS)

    The HERA magnet system will be cooled by a helium liquefier-refrigerator. The design of the plant is described and the first results of some performance tests for refrigeration power at 4.4 K and between 40 K and 80 K and for liquefaction rates at 4.4 K with one coldbox system out of three are presented. Preliminary values for coldbox and compressor group efficiencies were calculated

  9. THE APPLICATION OF THE ADVANCED ENERGY STORAGE TECHNOLOGY IN THE SOLAR POWERED REFRIGERATION SYSTEM%溶液浓度差蓄能技术在太阳能蓄能制冷中的应用

    Institute of Scientific and Technical Information of China (English)

    黄晓东; 徐士鸣

    2012-01-01

    为了研究太阳能蓄能制冷过程中各工作参数随时间变化的关系,建立直接加热溶液的太阳集热器和蓄能制冷系统的动态数学模型,利用计算机进行动态数值模拟,得到太阳集热器与溶液储罐环路内工作溶液循环和蓄能制冷循环特性.%The dynamic mathematical models of the solar collector and the energy storage refrigeration system were established for researching the relationship of the working parameters with the time in the system. And then the op-eration characteristics of the solar powerd energy storage refrigeration system were obtained by computer numerical simulation.

  10. The Modification of the Valves of a Refrigeration Piston Compressor due to the Refrigerant Change

    OpenAIRE

    Li Liansheng; Zhao Yuanyang; Guo Bei; Shu Pengcheng

    2003-01-01

    Compressor and refrigerant play key roles in a refrigeration system. Owing to the de-mands of environment protection, the CFCs and HCFCs refrigerants will be phased out in a short time, and new refrigerants such as R600, R134a and R407C will be used. As the new refrigerant is selected, the motion regularity of the valves will be changed. The motion regularity of the ring valves of a 2-stage refrigerating piston compressor is simulated, and the calculations are done respectively with refrigera...

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

    CERN Document Server

    Bjørk, R; Bahl, C R H; Pryds, N

    2014-01-01

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

  12. A resorption refrigerator driven by low grade thermal energy

    International Nuclear Information System (INIS)

    Highlights: → A resorption refrigerator employing MnCl2-NH3 and NH4Cl-NH3 was designed and investigated. → The experiments were operated under different ambient temperatures from 20 to 35 oC. → The refrigerator provided simultaneously two cooling levels: at 0-6 oC and at -16 ∼ -14.5 oC. → With 3 h operation the total cooling capacity was 475 kJ per kg of NH4Cl salt. → The effective cooling production was 25-42% of the total cooling capacity. -- Abstract: A small refrigerator based on resorption technique, employed MnCl2 and NH4Cl as sorbent salts and ammonia as refrigerant, was presented for simultaneously cooling at 0-6 oC and freezing at -16 to -14.5 oC in this work. The cooling capacity of this device was investigated by measuring the mass amount of the ice generated during a certain period of 3 h operation, and the experiments were conducted at different ambient temperature ranging from 20 oC to 35 oC. The total cooling capacity was calculated 475 kJ per kg of NH4Cl salt, and the mean specific cooling power (SCP) was 43 W per kg of NH4Cl salt, the effective cooling production responsible for making ice accounted for 25-42% of the total cooling capacity depending on the different operating conditions studied in this work.

  13. 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 ostatní: NSERC(CA) OGP1041 Institutional research plan: CEZ:AV0Z40720504 Keywords : refrigerants * molecular simulations * vapor–liquid equilibrium Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.853, year: 2010

  14. Novel refrigerator development

    International Nuclear Information System (INIS)

    In Section 1, we describe how the creation of quasiparticles by current flow through a normal-insulator-superconductor (NIS) junction degrades the cooling performance of the junction. Degradation occurs due to the absorption of recombination phonons in the normal electrode and due to a reduction in the cooling power. In Section 2, we describe how vibrations from a pulse tube mechanical cooler affect X-ray measurements performed with a superconducting tunnel junction

  15. Three-terminal heat engine and refrigerator based on superlattices

    Science.gov (United States)

    Choi, Yunjin; Jordan, Andrew N.

    2015-11-01

    We propose a three-terminal heat engine based on semiconductor superlattices for energy harvesting. The periodicity of the superlattice structure creates an energy miniband, giving an energy window for allowed electron transport. We find that this device delivers a large power, nearly twice than the heat engine based on quantum wells, with a small reduction of efficiency. This engine also works as a refrigerator in a different regime of the system's parameters. The thermoelectric performance of the refrigerator is analyzed, including the cooling power and coefficient of performance in the optimized condition. We also calculate phonon heat current through the system and explore the reduction of phonon heat current compared to the bulk material. The direct phonon heat current is negligible at low temperatures, but dominates over the electronic at room temperature and we discuss ways to reduce it.

  16. Performance analysis of a solar photovoltaic operated domestic refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Modi, Anish; Chaudhuri, Anirban; Vijay, Bhavesh; Mathur, Jyotirmay [Mechanical Engineering Department, Malaviya National Institute of Technology (MNIT), Jaipur 302 017 (India)

    2009-12-15

    This paper describes the fabrication, experimentation and simulation stages of converting a 165 l domestic electric refrigerator to a solar powered one. A conventional domestic refrigerator was chosen for this purpose and was redesigned by adding battery bank, inverter and transformer, and powered by solar photovoltaic (SPV) panels. Various performance tests were carried out to study the performance of the system. The coefficient of performance (COP) was observed to decrease with time from morning to afternoon and a maximum COP of 2.102 was observed at 7 AM. Simulations regarding economic feasibility of the system for the climatic conditions of Jaipur city (India) were also carried out using RETScreen 4. It was observed that the system can only be economically viable with carbon trading option taken into account, and an initial subsidy or a reduction in the component costs - mainly SPV panels and battery bank. (author)

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

    Science.gov (United States)

    Komatsubara, Takeo; Sunaga, Takasi; Takahasi, Yasuki

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

  18. Rotational type of a gravitational ejector refrigerator - A system balance of the refrigerant analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kasperski, Jacek [Wroclaw University of Technology, Institute of Power Engineering and Fluid Mechanics, Wybrzeze Wyspianskiego 27, Wroclaw 50-370 (Poland)

    2010-01-15

    The existing ejector systems were analyzed depending on the way in which the refrigerant returns from the condenser to the generator and evaporator. The research focused on gravitational ejector refrigerator in which hydrostatic pressure of the refrigerant allows to equalize pressure differences between heat exchangers located on different levels. Using centrifugal acceleration instead of gravitational allows to decrease significantly the size of a refrigerator. The name roto-gravitational refrigerator was proposed for that kind of refrigerator. One of the problems of small, compact refrigerators is a little amount of refrigerant. Surrounding temperatures when different from typical may cause drying up of the refrigerant in the exchangers and lead to destabilizing the refrigerator's work. A mathematical analysis of thermal and flow processes occurring in the refrigerant has been conducted. A mathematical model of the refrigerant balance and its numerical solution has been proposed. The analysis of the refrigerator accelerating temperature influence on its work parameters has been conducted for exemplary calculations. (author)

  19. Available energy analysis of new tandem double-capillary tube refrigeration system for refrigerator-freezers

    Institute of Scientific and Technical Information of China (English)

    Maogang HE; Xinzhou SONG; Ying ZHANG; Jiantao ZHANG

    2008-01-01

    A new tandem double-capillary tube refri-geration system for refrigerator-freezers is proposed. A capillary tube was added between the two evaporators in the fresh and frozen food storage chests to raise the evaporation temperature of the refrigerating chamber, and reduce the heat exchange temperature difference and the available energy loss. Peng-Robinson (P-R) equation of state was adopted to calculate the thermodynamic properties of the refrigerants, and the available energy analysis of the vapor compression refrigeration cycle was programmed to calculate the thermodynamic perfor-mances of the new and the conventional refrigeration cycle of the refrigerator-freezer. The calculation results show that the available energy efficiency of the conven-tional refrigeration cycle of the refrigerator-freezer is 21.20% and 20.57%, respectively when the refrigerant is R12 and R134a, while that of the double-capillary tube refrigeration cycle of the refrigerator-freezer is 23.97% and 23.44%, respectively. By comparison, the available energy efficiency of the new refrigeration system increases by 13.07% and 13.95%, respectively.

  20. Load management for refrigeration systems: Potentials and barriers

    International Nuclear Information System (INIS)

    As a strategy to deal with the increasing intermittent input of renewable energy sources in Germany, the adaptation of power consumption is complementary to power-plant regulation, grid expansion and physical energy storage. One demand sector that promises strong returns for load management efforts is cooling and refrigeration. In these processes, thermal inertia provides a temporal buffer for shifting and adjusting the power consumption of cooling systems. We have conducted an empirical investigation to obtain a detailed and time-resolved bottom-up analysis of load management for refrigeration systems in the city of Mannheim, Germany. We have extrapolated our results to general conditions in Germany. Several barriers inhibit the rapid adoption of load management strategies for cooling systems, including informational barriers, strict compliance with legal cooling requirements, liability issues, lack of technical experience, an inadequate rate of return and organizational barriers. Small commercial applications of refrigeration in the food-retailing and cold storage in hotels and restaurants are particularly promising starting points for intelligent load management. When our results are applied to Germany, suitable sectors for load management have theoretical and achievable potential values of 4.2 and 2.8 GW, respectively, amounting to about 4-6% of the maximum power demand in Germany. - Highlights: → Potential and barriers for implementation of load shifting for refrigeration. → Empirical investigation for time-resolved bottom-up analysis in Mannheim, Germany. → Suitable sectors and further recommendations for introducing load management.→ Extrapolation of results from local to national level.

  1. Cooldown Measurements in a Standing Wave Thermoacoustic Refrigerator

    OpenAIRE

    Dhuley, R. C.; Atrey, M. D.

    2016-01-01

    Thermoacoustic Refrigerators (TARs) use acoustic power to generate cold temperatures. Apart from the operating frequency and the mean temperature of the working medium, the charging pressure and the dynamic pressure in the TAR govern its attainable cold temperature. The effect of charging pressure on the dynamic pressure in a loudspeaker driven gas filled standing wave column has been well understood. The present work aims to investigate the effect of charging pressure on the cold end tempera...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    A modular modeling approach of supermarket refrigeration systems (SRS) which is appropriate for smart grid control purposes is presented in this paper. Modeling and identification are performed by just knowing the system configuration and measured data disregarding the physical details. So, this...... regarding their power/energy consumptions in the future smart grids. Moreover, the developed model is validated by real data collected from a supermarket in Denmark. The utilization of the produced model is also illustrated by a simple simulation example....

  3. Quantum-enhanced absorption refrigerators.

    Science.gov (United States)

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

    2014-01-01

    Thermodynamics is a branch of science blessed by an unparalleled combination of generality of scope and formal simplicity. Based on few natural assumptions together with the four laws, it sets the boundaries between possible and impossible in macroscopic aggregates of matter. This triggered groundbreaking achievements in physics, chemistry and engineering over the last two centuries. Close analogues of those fundamental laws are now being established at the level of individual quantum systems, thus placing limits on the operation of quantum-mechanical devices. Here we study quantum absorption refrigerators, which are driven by heat rather than external work. We establish thermodynamic performance bounds for these machines and investigate their quantum origin. We also show how those bounds may be pushed beyond what is classically achievable, by suitably tailoring the environmental fluctuations via quantum reservoir engineering techniques. Such superefficient quantum-enhanced cooling realises a promising step towards the technological exploitation of autonomous quantum refrigerators. PMID:24492860

  4. CO2 as a refrigerant

    CERN Document Server

    2014-01-01

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

  5. 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…

  6. Monomer Adsorption-Desorption Processes

    Institute of Scientific and Technical Information of China (English)

    KE Jian-Hong; LIN Zhen-Quan; CHEN Xiao-Shuang

    2009-01-01

    We propose an adsorption-desorption model for a deposit growth system, in which the adsorption and desorption of particles coexist. By means of the generalized rate equation we investigate the cluster (island) size distribution in the dynamic equilibrium state. The results show that the evolution behaviour of the system depends crucially on the details of the rate kernels. The cluster size distribution can take the ecale-frse power-law form in some cases, while it grows exponentially with size in other cases.

  7. Suction muffler for refrigeration compressor

    Science.gov (United States)

    Nelson, Richard T.; Middleton, Marc G.

    1983-01-01

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

  8. A generalized magnetic refrigeration scheme

    OpenAIRE

    Tamura, Ryo; Ohno, Takahisa; Kitazawa, Hideaki

    2013-01-01

    We have investigated the magnetocaloric effects in antiferromagnets and compared them with those in ferromagnets using Monte Carlo simulations. In antiferromagnets, the magnetic entropy reaches a maximum value at a finite magnetic field when the temperature is fixed below the N\\'eel temperature. Using the fact, we proposed a protocol for applying magnetic fields to achieve the maximum efficiency for magnetic refrigeration in antiferromagnets. In particular, we found that at low temperatures, ...

  9. Hermetic compressor and block expansion valve in refrigeration performance

    Science.gov (United States)

    Santoso, Budi; Susilo, Didik Djoko; Tjahjana, D. D. D. P.

    2016-03-01

    Vehicle cabin in tropical countries requires the cooling during the day for comfort of passengers. Air conditioning machine is commonly driven by an internal combustion engine having a great power, which the conventional compressor is connected to crank shaft. The stage of research done is driving the hermetic compressor with an electric motor, and using block expansion valve. The HFC-134a was used as refrigerant working. The primary parameters observed during the experiment are pressure, temperature, and power consumption for different cooling capacities. The results show that the highest coefficient of performance (COP) and the electric power of system are 6.3 and 638 Watt, respectively.

  10. Adsorption and wetting.

    OpenAIRE

    Schlangen, L.J.M.

    1995-01-01

    Adsorption and wetting are related phenomena. In order to improve knowledge of both and their relations, experiments, thermodynamics and a theoretical interpretation have been connected, starring n-alkanes.Starting from the Gibbs adsorption equation thermodynamic relations between vapour adsorption and wetting are derived. The surface pressure of a film, formed by vapour adsorption on a solid surface, is calculated by integrating the vapour adsorption isotherm. The surface pressure at the sat...

  11. Thermodynamic optimization of irreversible refrigerators

    International Nuclear Information System (INIS)

    Highlights: • Dimensionless equation that links COP, entropy rate variation and heat exchange. • Maximum COP as function of parameter controlling thermal exchanges. • Application at irreversible vapor compression refrigerator based on literature data. • Results show the analysis is useful in diagnostic and designing of refrigerators. - Abstract: An irreversible inverse cycle, operating at steady state conditions with finite thermal capacity heat sources, is analyzed in order to obtain an expression for the coefficient of performance accounting for the Second Law. Some dimensionless parameters are proposed to link the entropy variation rate and the temperature differences at the heat exchangers to the cycle efficiency. A maximum for efficiency appears when a parameter depending only on the temperature of the inlet streams at each heat exchanger is used. The influence of dimensionless parameters and irreversibilities on the maximum cycle efficiency is analyzed. A graphical analysis, based on data from literature, is presented to show the use of this thermodynamic optimization criteria in design and verification process of refrigerators

  12. Simulation of a refrigerant evaporator

    Science.gov (United States)

    Vandermeer, Jakob Stefanus

    A computer model for the design and optimization of the compressor refrigeration cycle especially with respect to dynamic behavior was developed. A steady state version was also developed. The model describing the refrigerant is divided into the evaporation and superheating regions. A mechanism based on empirics corrects the model for the influence of transportation times in the evaporation region. The mass balance of the refrigerant in the superheat region is regarded as quasi-static, because of the small mass of the vapor. The energy balance accounts for a distributed model and is represented by the steady state solution of the partial differential equation which describes this area for the steady conditions. A correction for the dynamical effects was added to this solution, for all influencing parameters, according to the analytical dynamic solution for the case of the evaporation temperature as input parameter. The expansion device model was worked out for the usual type of device in combination with a dry evaporator, the thermostatic expansion valve. Validation tests are described.

  13. Continuous vapour adsorption cooling system with three adsorber beds

    International Nuclear Information System (INIS)

    In this paper, the design of a new solar operated adsorption cooling system with two identical small and one large adsorber beds, which is capable of producing cold continuously, has been proposed. In this system, cold energy is stored in the form of refrigerant in a separate refrigerant storage tank at ambient temperature. Silica gel–water is used as a working pair and system is driven by solar energy. The operating principle is described in details and its thermodynamic transient analysis is presented. Effect of COP and SCE for different adsorbent mass and adsorption/desorption time of smaller beds are discussed. Recommended mass and number of cycles of operation for smaller beds to attain continuous cooling with average COP and SCE of 0.63 and 337.5 kJ/kg, respectively are also discussed, at a generation, condenser and evaporator temperatures of 368 K, 303 K and 283 K, respectively. - Highlights: • A three-bed silica gel–water continuous adsorption cooling system is analyzed. • Cold energy is stored in the form of liquid refrigerant at ambient temperature. • The influence of mass of beds and cycle time on the system performance is discussed. • Sizing of the beds for a given cooling capacity is recommended

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-04-04

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

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

    OpenAIRE

    YAKAR, Gülay; KARABACAK, Rasim; Burçin DEDA ALTAN

    2005-01-01

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

  16. 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...

  17. 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 ...

  18. 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...

  19. 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.

  20. The Design and Performance Analysis of Refrigeration System Using R12 & R134a Refrigerants

    OpenAIRE

    K. Nagalakshmi; G. Marurhiprasad Yadav

    2014-01-01

    The design and performance analysis of refrigeration system using R12 & R134a refrigerants are presented in this report. The design calculations of the suitable and necessary refrigerator equipment and their results are also reported here. CFC-12 is the most widely used refrigerant. It serves both in residential and commercial applications, from small window units to large water chillers, and everything in between. Its particular combination of efficiency, capacity and pressur...

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

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Francis

    2014-06-30

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

  2. A versatile magnetic refrigeration test device

    OpenAIRE

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

    2008-01-01

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

  3. Ecological optimization for generalized irreversible Carnot refrigerators

    International Nuclear Information System (INIS)

    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

  4. 太阳能制冷讲座(4)太阳能吸附制冷技术(上)%Lectures on solar cooling 4 Solar-powered adsorption refrigeration technology pt.1

    Institute of Scientific and Technical Information of China (English)

    尹亚领; 代彦军; 王如竹

    2010-01-01

    阐述了太阳能吸附制冷技术的运行原理、性能参数和系统基本设计方法,介绍了太阳能吸附空调系统国内外工程应用情况,并对其应用前景进行了分析和总结.

  5. Lectures on solar cooling 5 Solar-powered adsorption refrigeration technology pt.2%太阳能制冷讲座(5)太阳能吸附制冷技术(下)

    Institute of Scientific and Technical Information of China (English)

    尹亚领; 代彦军; 王如竹

    2010-01-01

    @@ 五太阳能吸附空调研究及实例太阳能吸附制冷在过去的二三十年里开始被广泛研究.太阳能吸附制冷的实验研究也开始逐渐增多.1986年,Pons和Guillemiont使用6m2的集热器驱动吸附机制冰,在太阳辐射达到22MJ/(m2·d)时,每天可制得冰块30~35kg[11].

  6. ABOUT TEMPERATURE FIELD VISUALIZATION OF THE REFRIGERATING CHAMBER EVAPORATOR OF THE HOUSEHOLD REFRIGERATOR

    OpenAIRE

    Горін, О.М.; М.В. Дьомін; Кудрін, О.Б.; Бурдіян, О.М.

    2015-01-01

    Experimental researches of temperature distribution on the evaporator surface of the household DH-239 refrigerating appliance working at isobutane depending on a charge dose of refrigerating system are conducted. The received results can be used for microleaks diagnosing methods development during household refrigerating appliances operation. 

  7. Design Guidelines For a Thermoacoustic Refrigerator

    CERN Document Server

    Dhuley, Ram C

    2016-01-01

    Development of refrigerators based on Thermoacoustic technology is a novel solution to the present day need of cooling without causing environmental hazards. With added advantages of absence of moving parts and circulating refrigerants, these devices can attain very low temperatures maintaining a compact size. The present theoretical work is based on theory of linear thermoacoustics[1]. Under the short stack and invicid assumptions, an algorithm for design of a standing wave thermoacoustic refrigerator, with main focus on the stack, is described. A stack is designed for a given cooling requirement of the refrigerator and certain chosen operation parameters.

  8. Application of magnetic refrigeration and its assessment

    Science.gov (United States)

    Kitanovski, Andrej; Egolf, Peter W.

    2009-04-01

    Magnetic refrigeration has the potential to replace conventional refrigeration—with often problematic refrigerants—in several niche markets or even some main markets of the refrigeration domain. Based on this insight, for the Swiss Federal Office of Energy a list of almost all existing refrigeration technologies was worked out. Then an evaluation how good magnetic refrigeration applies to each of these technologies was performed. For this purpose a calculation tool to determine the coefficient of performance ( COP) and the exergy efficiency as a function of the magnetic field strength and the rotation frequency of a rotary-type magnetic refrigerator was developed. The evaluation clearly shows that some application domains are more ideal for a replacement of conventional refrigerators by their magnetic counterparts than others. In the pre-study, four good examples were chosen for a more comprehensive investigation and working out of more detailed results. In this article, the calculation method is briefly described. COP values and exergy efficiencies of one very suitable technology, namely the magnetic household refrigerator, are presented for different operation conditions. Summarizing, it is stated that magnetic refrigeration is a serious environmentally benign alternative to some conventional cooling, refrigeration and air-conditioning technologies.

  9. Development of a rotary magnetic refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Tusek, Jaka; Zupan, Samo; Sarlah, Alen; Prebil, Ivan; Poredos, Alojz [University of Ljubljana, Faculty of Mechanical Engineering, Askerceva c. 6, 1000 Ljubljana (Slovenia)

    2010-03-15

    A team of researchers have developed and built a prototype of a rotary magnetic refrigerator (MR). The principle of the operation of the presented magnetic refrigerator is based on the rotary movement of active magnetic regenerators (AMRs) with a magnetocaloric material and on the magnetic field generated by permanent magnets Nd-Fe-B. The first part of the paper presents the development and analysis of the structure for generating the magnetic field and the basic operational principle of the magnetic refrigerator concerned, and the second part gives a description of the development process for certain key elements of the complete magnetic refrigeration system. (author)

  10. Commissioning of the Tevatron Satellite Refrigeration system

    International Nuclear Information System (INIS)

    This chapter describes the cooling of the new Fermilab 6 km circumference superconducting proton accelerator by a 5000 L/h central helium liquefier (CHL) coupled with 24 satellite refrigerators (966W each). The Tevatron Satellite Refrigeration system includes a liquid helium/liquid nitrogen transfer line made up of twenty six-250 m long sections. Topics considered include transfer line operation, compressor system operation, satellite refrigeration operational experience, contamination, expansion engine efficiency, control loop stability, pressure drop, the magnet system operational experience, magnet cooldown, vacuum deficiencies, and magnet excitation. It is concluded that the satellite refrigerator concept has proven to be a reliable design for the Tevatron

  11. United States: refrigeration industry blows hot

    International Nuclear Information System (INIS)

    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

  12. Optimum performance analysis of an energy selective electron refrigerator affected by heat leaks

    Energy Technology Data Exchange (ETDEWEB)

    He Jizhou; Wang Xiaomin [Department of Physics, Nanchang University, Nanchang 330031 (China); Liang Hongni [CALIS Information Service Center of Jiangxi Province, Nanchang University, Nanchang 330031 (China)], E-mail: hjzhou@ncu.edu.cn

    2009-09-15

    An energy selective electron (ESE) refrigerator with heat leaks is established in a one-dimensional system. Based on the theory of electronic transport, the expressions of the heat flux into hot and cold electron reservoirs are derived. When the heat leaks between two electron reservoirs via phonons are taken into account, the cooling rate, coefficient of performance (COP) and input power are obtained. The performance characteristic curves such as the cooling rate versus the COP, the cooling rate and the COP versus the center position of the resonance energy level are plotted by numerical calculation. The influence of the center position and width of the resonance energy level on the performance of the ESE refrigerator is analyzed in detail. Lastly, the influence of heat leaks and average temperature on the performance of the ESE refrigerator is discussed. The results obtained here have theoretical significance for understanding the thermodynamic performance of the practical ESE refrigerator.

  13. Electric energy saving potential by substitution of domestic refrigerators in Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arroyo-Cabanas, F.G. [Posgrado en Ingenieria, Universidad Nacional Autonoma de Mexico, A. P. 20-364, Mexico, Distrito Federal, C.P. 05500 (Mexico); Programa de Energia, Universidad Autonoma de la Ciudad de Mexico, San Lorenzo 290, Col. Del Valle, Del. Benito Juarez, Mexico, Distrito Federal, C.P. 03100 (Mexico); Aguillon-Martinez, J.E. [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, A. P. 20-364, Mexico, Distrito Federal, C.P. 05500 (Mexico); Ambriz-Garcia, J.J. [Ingenieria en Recursos Energeticos, Universidad Autonoma Metropolitana, Av. San Rafael Atlixco 186, Col. Vicentina, C.P. 09340, Iztapalapa, Mexico, Distrito Federal (Mexico); Canizal, G. [Programa de Energia, Universidad Autonoma de la Ciudad de Mexico, San Lorenzo 290, Col. Del Valle, Del. Benito Juarez, Mexico, Distrito Federal, C.P. 03100 (Mexico)

    2009-11-15

    We evaluate the potential for electric power saving in Mexico that would follow the substitution of old, low efficiency domestic refrigerators with modern, high efficiency ones. Our results indicate that a total substitution of domestic refrigerators would save 4.7 TWh/year, which represents 33% of the annual total consumption of 14.1 TWh. Assuming an average daily use of 14 h for domestic refrigeration, 900 MW of electricity would be saved. An annual substitution of 20% over 5 years would save approximately 1 TWh a year and almost 180 MW would be released. It is recommended that this program of replacement should be supported by the Federal and State governments, beginning with the States (which have more direct influence), and with the oldest, least efficient refrigerators along the lines followed in programs that introduced fluorescent compact lamps. (author)

  14. Development and Evaluation of a Prototype Refrigerated Cooling Table for Conference Services

    Directory of Open Access Journals (Sweden)

    Abubakar Mohammed

    2012-05-01

    Full Text Available This paper presents the development and evaluation of a prototype refrigerated cooling table for conference services. The major components of the table are compressor, condenser, evaporator, capilary tube, thermostat and table metal wooden frame. The table uses vapour compression cycle based on the Evans-Perkins (reverseRankine cycle as its principle of operation. The evaporator has three cabinet ports. Plywood and square mild steel pipes are used for the construction of the table frame. The refrigerated cooling table successfully reduces temperature of beverages from 35°C to 15.5°C, 13°C and 11°C, when placed in a plastic, glass and stainlesssteel containers respectively. The refrigerated cooling table performs better when compared with a standard domestic refrigerator. The coefficient of performance using experimental values is 5.14 with a compressor power of 69.3W for three participants.

  15. Optimization of the performance characteristics in an irreversible regeneration magnetic Brayton refrigeration cycle

    Science.gov (United States)

    Wang, Hao; Wu, GuoXing

    2012-02-01

    A model of the irreversible regenerative Brayton refrigeration cycle working with paramagnetic materials is established, in which the regeneration problem in two constant-magnetic field processes and the irreversibility in two adiabatic processes are considered synthetically. Expressions for the COP, cooling rate, power input, the minimum ratio of the two magnetic fields, etc., are derived. It is found that the influence of the irreversibility and the regeneration on the main performance parameters of the magnetic Brayton refrigerator is remarkable. It is important that we have obtained several optimal criteria, which may provide some theoretical basis for the optimal design and operation of the Brayton refrigerator. The results obtained in the paper can provide some new theoretical information for the optimal design and performance improvement of real Brayton refrigerators.

  16. Performance characteristics and optimal analysis of a nanosized quantum dot photoelectric refrigerator.

    Science.gov (United States)

    Li, Cong; Zhang, Yanchao; Wang, Jianhui; He, Jizhou

    2013-12-01

    We study the thermodynamic performance of a nanosized photoelectric refrigerator consisting of three coupled single-level quantum dots embedded between two reservoirs at different temperatures. Based on the quantum master equation, we derive expressions for the cooling power and coefficient of performance (COP) of the refrigerator and plot the characteristic curves between the cooling power and the COP. We analyze the optimal performance parameters under conditions of maximum cooling power and maximum COP, and we discuss the influence of the energy level difference and the temperature ratio on the optimal performance parameters in detail. PMID:24483399

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

    International Nuclear Information System (INIS)

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-29

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

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

    Science.gov (United States)

    Gondrand, C.; Durand, F.; Delcayre, F.; Crispel, S.; Baguer, G. M. Gistau

    2014-01-01

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

  20. 1990 ASHRAE Handbook on refrigeration systems and applications

    International Nuclear Information System (INIS)

    This book covers refrigeration equipment or systems in a particular application, process, or cold storage facility and describes current designs for specific applications. Also covered are industrial applications of refrigeration and an introduction to low temperature refrigeration

  1. Refrigerant charge management in a heat pump water heater

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jie; Hampton, Justin W.

    2016-07-05

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

  2. ALTERNATIVE TECHNOLOGIES FOR REFRIGERATION AND AIR-CONDITIONING APPLICATIONS

    Science.gov (United States)

    The report gives results of an assessment of refrigeration technologies that are alternatives to vapor compression refrigeration for use in five application categories: domestic air conditioning, commercial air conditioning, mobile air conditioning, domestic refrigeration, and co...

  3. Dynamic Simulation of Household Refrigerators: Numerical Model and Experimental Comparison

    OpenAIRE

    Ablanque, Nicolas; Oliet, Carles; Rigola, Joaquim; Lehmkuhl, Oriol; Oliva, Assensi

    2014-01-01

    This work presents a dynamic model to simulate a whole household refrigeration unit taking into account both the refrigeration cycle itself and the refrigerated compartments network. The methodology implemented to achieve the transient simulation of the whole system combines a steady-state approach for the refrigerating cycle loop with a transient approach for the refrigerated compartments loop. Both loops are solved at each time step (the linking boundary conditions for the refrigerating cyc...

  4. Swiss provider of refrigerants opts for natural refrigerants; Traditioneller Kaeltemittelhaendler in der Schweiz setzt auf natuerliche Kaeltemittel

    Energy Technology Data Exchange (ETDEWEB)

    Knus, S.

    2005-10-01

    Friosol, a leading provider of synthetic refrigerant, now opts for natural refrigerants. Friosol has been on the market for more than 55 years, especially in Switzerland, and CFC refrigerants used to be their key line of business. (orig.)

  5. 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.

  6. Thermodynamic Heat Water by The Condenser of Refrigerator

    International Nuclear Information System (INIS)

    The present innovation relates to the coupling of a refrigerator to a cumulus to heat water and this, thanks to the heat yielded to the level of the condenser of the refrigerating system even. The heating of water is carried out thus without energy over consumption. The quantity of heat transferred by the water-cooled condenser is sufficient to raise the temperature of this latter with 60 degree at the end of five hours. This can satisfy completely or partially the requirements out of hot water of a family which can distribute its requirements out of hot water all along the day and the week. The quantity of heat recovered by water to heat rises with four multiples the power consumption by the compressor. The system thus makes it possible to save energy and to safeguard the environment

  7. Development of a novel refrigeration system for refrigerated trucks incorporating phase change material

    International Nuclear Information System (INIS)

    Highlights: ► A refrigeration system having low energy cost and producing no local greenhouse gas emission. ► A PCM is experimentally developed which is able to maintain the refrigerated truck at −18 °C. ► A TRNSYS model is developed to simulate the proposed refrigeration system. -- Abstract: An innovative refrigeration system incorporating phase change material (PCM) is proposed to maintain refrigerated trucks at the desired thermal conditions. The advantage of using PCM to maintain low temperatures is that a conventional refrigeration system does not have to be located on-board the vehicle. In addition, the system consumes less energy and produces much lower local greenhouse gas (GHG) emissions. The phase change thermal storage unit (PCTSU) is charged by a refrigeration unit located off the vehicle when stationary. The PCM is discharged and provides cooling when in service. A new PCM with a lower cost than currently available PCMs was developed, suitable for maintaining the refrigerated truck at a temperature of −18 °C. The PCM has a melting temperature of −26.7 °C and a latent heat of 154.4 kJ kg−1. A prototype system was constructed and test results proved that the proposed refrigeration system is feasible for mobile transport. An analysis shows that delivery of refrigerated products can be made with a PCM system having a weight comparable to that of an on board conventional refrigeration system with less than half of the energy cost.

  8. A multipurpose 3He refrigerator

    Science.gov (United States)

    Pizzo, L.; Dall'Oglio, G.; Martinis, L.; Sabbatini, L.

    2006-10-01

    We introduce a mini 3He refrigerator, operating at ˜300 mK starting from 4.2 K without pumping on the main 4He bath. The innovative idea is that the present one is suitable for a very fast operation; for its use, it is sufficient a storage 4He Dewar. In this way we drastically reduce the time required to cool it down, because there is no need for a classic cryostat. This prototype is particularly aimed for all those operations in which it is necessary to test a large number of samples that do not require long duration measurements at low temperature.

  9. Refrigeration and air-conditioning

    CERN Document Server

    Hundy, G H; Welch, T C

    2008-01-01

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

  10. Seven-effect absorption refrigeration

    Science.gov (United States)

    DeVault, Robert C.; Biermann, Wendell J.

    1989-01-01

    A seven-effect absorption refrigeration cycle is disclosed utilizing three absorption circuits. In addition, a heat exchanger is used for heating the generator of the low absorption circuit with heat rejected from the condenser and absorber of the medium absorption circuit. A heat exchanger is also provided for heating the generator of the medium absorption circuit with heat rejected from the condenser and absorber of the high absorption circuit. If desired, another heat exchanger can also be provided for heating the evaporator of the high absorption circuit with rejected heat from either the condenser or absorber of the low absorption circuit.

  11. Planar Joule-Thomson micro-refrigerator on silicon wafer

    International Nuclear Information System (INIS)

    The extension of technology of silicon microelectronics towards different fields of integrated circuitry has led to cryogenics micro-devices of Joule-Thomson type, where the cooling is obtained by gas expansion after passing through a drosel coil. In this work elements of modelling, design and technology of such a device are presented. The planar micro-refrigerator structure is based on a silicon wafer, on which the following elements are formed by micro-technology methods: admission collector, gas inlet channels, drosel, expansion chamber, passing opening, gas exhaust channels and outlet collector. These elements are covered with glass wafer and sealed at the exterior circuit by two inlet micro-tubes. The computation elements taken into account in designing the construction include: evaluation of component sizes, the calculation of dissipated power and of gas flow rate, the calculation of temperature jump, starting from a set of initial parameters as the pressure difference (ΔP), gas type, hot zone temperature (Th), refrigerating power (Pr), etc. The results of the calculation show that for ΔP = 150 bar, N2 gas and Th = 300 K, a cooling jump of over 200 K can be obtained in conditions of vacuum device functioning. At its placement in air the jump is reduces twice. Considerations of size scaling taken into account in calculation have shown that the refrigerating capacity decreases with increase of drosel coil cross section. The anisotropic silicon corrosion and electrostatic welding were new technological procedures used in constructing the micro-refrigerator. The model testing has confirmed the majority of the theoretical considerations taken as basis of design

  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 o...... controller and the methods are evaluated with respect to energy efficiency....

  13. Commercial Refrigeration Technology. Florida Vocational Program Guide.

    Science.gov (United States)

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    The program guide for commercial refrigeration technology courses in Florida identifies primary considerations for the organization, operation, and evaluation of a vocational education program. Following an occupational description for the job title for refrigeration mechanic, and its Dictionary of Occupational Titles code, are six sections…

  14. DESIGN AND OPTIMIZATION OF A REFRIGERATION SYSTEM

    Science.gov (United States)

    The paper discusses the design and optimization of a refrigeration system, using a mathematical model of a refrigeration system modified to allow its use with the optimization program. he model was developed using only algebraic equations so that it could be used with the optimiz...

  15. 21 CFR 1250.34 - Refrigeration equipment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Refrigeration equipment. 1250.34 Section 1250.34 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... SANITATION Food Service Sanitation on Land and Air Conveyances, and Vessels § 1250.34 Refrigeration...

  16. Entropy generation analysis of an adsorption cooling cycle

    KAUST Repository

    Thu, Kyaw

    2013-05-01

    This paper discusses the analysis of an adsorption (AD) chiller using system entropy generation as a thermodynamic framework for evaluating total dissipative losses that occurred in a batch-operated AD cycle. The study focuses on an adsorption cycle operating at heat source temperatures ranging from 60 to 85 °C, whilst the chilled water inlet temperature is fixed at 12.5 °C,-a temperature of chilled water deemed useful for dehumidification and cooling. The total entropy generation model examines the processes of key components of the AD chiller such as the heat and mass transfer, flushing and de-superheating of liquid refrigerant. The following key findings are observed: (i) The cycle entropy generation increases with the increase in the heat source temperature (10.8 to 46.2 W/K) and the largest share of entropy generation or rate of energy dissipation occurs at the adsorption process, (ii) the second highest energy rate dissipation is the desorption process, (iii) the remaining energy dissipation rates are the evaporation and condensation processes, respectively. Some of the noteworthy highlights from the study are the inevitable but significant dissipative losses found in switching processes of adsorption-desorption and vice versa, as well as the de-superheating of warm condensate that is refluxed at non-thermal equilibrium conditions from the condenser to the evaporator for the completion of the refrigeration cycle. © 2012 Elsevier Ltd. All rights reserved.

  17. He-H2 mixture and Er3NiHx packing for the refrigeration enhancement of pulse tube refrigerator

    Institute of Scientific and Technical Information of China (English)

    CHEN Guobang; TANG Ke; HUANG Yonghua; GAN Zhihua; BAO Rui

    2004-01-01

    The computation with the theory of modified Brayton Cycle indicates that higher cooling power and coefficient of performance for a pulse tube refrigerator can be achieved with He-H2 mixture as working gas than those with pure He in the temperature region of 30 K. In addition, it is found that Er3Ni, a regenerative material, is able to absorb H2 and produces Er3NiHx. The computation presents that the regenerative performance of Er3NiHx is better than that of Er3Ni due to its higher volume specific heat. Experimental results show that the pulse tube refrigeration performance in 30 K temperature region is enhanced greatly with He-H2mixture and Er3NiHx packing.

  18. Compatibility of refrigerants and lubricants with elastomers

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-10-01

    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 the availability of additional quantities of 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 hours and 24 hours for samples removed from the refrigerant test fluids and 24 hours after removal from the lubricants.

  19. 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.

  20. Dynamic simulation of a reverse Brayton refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Peng, N.; Xiong, L. Y.; Dong, B.; Liu, L. Q. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 (China); Lei, L. L.; Tang, J. C. [State Key Laboratory of Technologies in Space Cryogenic Propellants, Technical Institute of Physics and Chemistry, CAS, Beijing, 100190 China and Graduate University of Chinese Academy of Sciences, Beijing, 100190 (China)

    2014-01-29

    A test refrigerator based on the modified Reverse Brayton cycle has been developed in the Chinese Academy of Sciences recently. To study the behaviors of this test refrigerator, a dynamic simulation has been carried out. The numerical model comprises the typical components of the test refrigerator: compressor, valves, heat exchangers, expander and heater. This simulator is based on the oriented-object approach and each component is represented by a set of differential and algebraic equations. The control system of the test refrigerator is also simulated, which can be used to optimize the control strategies. This paper describes all the models and shows the simulation results. Comparisons between simulation results and experimental data are also presented. Experimental validation on the test refrigerator gives satisfactory results.

  1. Magnetic refrigeration study at CEA Grenoble

    International Nuclear Information System (INIS)

    Two kinds of applications are considered for magnetic refrigeration, first in the 1.80K range mainly for He II cooling of superconductors and second for He I refrigeration with precooling near 20 K. At He II temperatures, refrigeration by a Carnot cycle has been investigated and analysed. We give a survey of the results which demonstrate the capability of magnetic refrigeration to attain high thermodynamic efficiency. More interest is now devoted to He I cooling for which we compare magnetic refrigeration to the standard existing solutions. For temperatures higher than 10 K, we discuss the interest and the constraints of cycles with internal heat exchange. Analysis of various configurations is given to explain the choice of a new experiment being built

  2. Dynamic simulation of a reverse Brayton refrigerator

    International Nuclear Information System (INIS)

    A test refrigerator based on the modified Reverse Brayton cycle has been developed in the Chinese Academy of Sciences recently. To study the behaviors of this test refrigerator, a dynamic simulation has been carried out. The numerical model comprises the typical components of the test refrigerator: compressor, valves, heat exchangers, expander and heater. This simulator is based on the oriented-object approach and each component is represented by a set of differential and algebraic equations. The control system of the test refrigerator is also simulated, which can be used to optimize the control strategies. This paper describes all the models and shows the simulation results. Comparisons between simulation results and experimental data are also presented. Experimental validation on the test refrigerator gives satisfactory results

  3. Oil cooled, hermetic refrigerant compressor

    Science.gov (United States)

    English, William A.; Young, Robert R.

    1985-01-01

    A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump. By providing the oil cooling of the parts, the suction gas is not used for cooling purposes and accordingly increase in superheat is substantially avoided in the passage of the suction gas through the shell to the suction plenum 64.

  4. Estimates of Refrigerator Loads in Public Housing Based on Metered Consumption Data

    Energy Technology Data Exchange (ETDEWEB)

    Miller, JD; Pratt, RG

    1998-09-11

    The New York Power Authority (NYPA), the New York City Housing Authority (NYCHA), and the U.S. Departments of Housing and Urban Development (HUD) and Energy (DOE) have joined in a project to replace refrigerators in New York City public housing with new, highly energy-efficient models. This project laid the ground work for the Consortium for Energy Efficiency (CEE) and DOE to enable housing authorities throughout the United States to bulk-purchase energy-efficient appliances. DOE helped develop and plan the program through the ENERGY STAR@ Partnerships program conducted by its Pacific Nofiwest National Laboratory (PNNL). PNNL was subsequently asked to conduct the savings evahations for 1996 and 1997. PNNL designed the metering protocol and occupant survey, supplied and calibrated the metering equipment, and managed and analyzed the data. The 1996 metering study of refrigerator energy usage in New York City public housing (Pratt and Miller 1997) established the need and justification for a regression-model-based approach to an energy savings estimate. The need originated in logistical difficulties associated with sampling the population and pen?orming a stratified analysis. Commonly, refrigerators[a) with high representation in the population were missed in the sampling schedule, leaving significant holes in the sample and difficulties for the stratified anrdysis. The just{jfcation was found in the fact that strata (distinct groups of identical refrigerators) were not statistically distinct in terms of their label ratio (ratio of metered consumption to label rating). This finding suggested a general regression model could be used to represent the consumption of all refrigerators in the population. In 1996 a simple two-coefficient regression model, a function of only the refrigerator label rating, was developed and used to represent the existing population of refrigerators. A key concept used in the 1997 study grew from findings in a small number of apartments

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

    International Nuclear Information System (INIS)

    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.

  6. The performance characteristics of an irreversible quantum Otto harmonic refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, an irreversible quantum Otto refrigeration cycle working with harmonic systems is established. Base on Heisenberg quantum master equation, the equations of motion for the set of harmonic systems thermodynamic observables are derived. The simulated diagrams of the quantum Otto refrigeration cycle are plotted. The relationship between average power of friction, cooling rate, power input, and the time of adiabatic process is analyzed by using numerical calculation. Moreover, the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is discussed.

  7. The performance characteristics of an irreversible quantum Otto harmonic refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    HE JiZhou; HE Xian; TANG Wei

    2009-01-01

    In this paper,an irreversible quantum Otto refrigeration cycle working with harmonic systems is estab-lished.Base on Heisenberg quantum master equation,the equations of motion for the set of harmonic systems thermodynamic observables are derived.The simulated diagrams of the quantum Otto refrig-eration cycle are plotted.The relationship between average power of friction,cooling rate,power input,and the time of adiabatic process is analyzed by using numerical calculation.Moreover,the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is dis-cussed.

  8. Thermal coated heat exchangers as a fundament for compact and dynamic evaporator in adsorption chillers and adsorption storages; Thermisch-beschichtete Waermeuebertrager als Basis fuer kompakte und dynamische Verdampfer in Adsorptionskaelteanlagen und -speichern

    Energy Technology Data Exchange (ETDEWEB)

    Lanzerath, Franz; Steinhilber, Matthias; Bardow, Andre [RWTH Aachen Univ. (Germany). Lehrstuhl fuer Technische Thermodynamik

    2012-07-01

    The advantage of adsorption chillers in the utilization of waste heat or solar heat often is underestimated by the low power density of the plants. This especially is true for mobile applications where size and weight of a component are crucial criteria, or for storage applications that require high dynamics and thus low thermal mass. In this connection, in many cases, the evaporator is the limiting component, since adsorption place special demands on the heat exchanger: The heat coupling must occur in order to maximize the vapor pressure at low temperature differences, so that the adsorption does not shift adversely. In addition, the physical properties of the widely used natural water as a refrigerant are unfavorable at low temperatures and complicate the process of evaporation. Nevertheless, in order to achieve sufficient heat transfer, large areas and correspondingly heavy evaporators are required. Thus, optimized heat exchangers are used in modern evaporators. In addition to the known positive properties of structured surfaces (for example rib structure), the authors were able to demonstrate the potential of thermal coatings, recently. The thermal coating of simple straight tubes resulted in an improvement of heat transfer by a factor of eight. The combination of macroscopic rib structure and thermal coating facilitates further improvements. The authors of the contribution under consideration report on the advantages of the new heat exchangers when operating an adsorption chiller. Thus, the impact of water level and cycle time on the evaporator capacity and adsorption per amount of cold produced is analyzed quantitatively. The impact of the k-value on the evaporation temperature is shown. The results show that the water level in the evaporator has a large impact on the cooling capacity of the adsorption system. Therefore, the optimal operating point must be determined in order to fully exploit the potential of the heat exchanger. The strong level dependence is

  9. Investigation of radiotracer adsorption

    International Nuclear Information System (INIS)

    Results of laboratory investigation of adsorption of radiotracers in several soil materials are presented. Compounds were chosen which are applied in hydrogeology for tracer determination of underground water flow parameters. Adsorption values were measured as functions of the following parameters: solution concentration, adsorption duration, concentration of hydrogen ions and ion strength of the solution. The most interesting results are: a linear dependence of adsorption on the solution concentration (observed in a wide range of concentrations), and an extended period (several tens of minutes) necessary for the adsorption system to achieve a state approaching dynamic equilibrium. (author)

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

    International Nuclear Information System (INIS)

    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.

  11. Local stability analysis of a non-endoreversible refrigerator

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yuewu [College of Environmental Science and Engineering, Donghua University, Shanghai 201620 (China); Sun, Dexing [School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090 (China)

    2008-08-15

    The purpose of this paper is to present a local stability analysis of a non-endoreversible refrigerator operating at the minimum input power P for given cooling load R absorbed from the cold reservoir, in the isothermal couplings of the working fluid with the heat reservoirs T{sub H} and T{sub L}(T{sub H} > T{sub L}) through a couple of thermal conductors, both having the same heat conductance {alpha} and using I to describe internal dissipations of the working fluid. A non-endoreversible refrigerator system that is modeled by the differential equation may depend on the numerical values of certain parameters that appear in the equation. From the local stability analysis we find that a critical point of an almost linear system is a stable node. After a small perturbation the system state exponentially decays to steady-state with either of two relaxation times that are a function {alpha}, I, R, T{sub L} and the heat capacity C. We can exhibit qualitatively the behavior of solutions of the system by sketching its phase portrait. One eigenvector in a phase portrait is the non-zero constant vector, and the other is a function of {alpha}, I, R, T{sub H} and T{sub L}. Finally, we discuss the local stability and energetic properties of the non-endoreversible refrigerator. (author)

  12. Parametric optimum design of an irreversible spin quantum refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    Lin Bi-Hong; Chen Jin-Can

    2005-01-01

    The general performance characteristics of an irreversible quantum refrigeration cycle using many non-interacting spin-1/2 systems as the working substance and consisting of two adiabatic and two isomagnetic field processes are investigated, based on the quantum master equation and semi-group approach. Expressions for several important performance parameters such as the coefficient of performance, cooling rate and power input are derived. By using numerical solutions, the cooling rate of the refrigeration cycle subject to the finite cycle duration is optimized. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal region of the coefficient of performance and the optimal ranges of the temperatures of the working substance and the times spent on the two isomagnetic field processes are determined. Moreover, the optimal performance of the cycle in the high-temperature limit is also analysed in detail. The results obtained here are further generalized, so that they may be directly used to describe the performance of the quantum refrigeration cycle using spin-J systems as the working substance.

  13. Conception and simulation of an improved solar refrigeration unit

    International Nuclear Information System (INIS)

    If the solar energy possesses the advantage to be clean, 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)

  14. General performance characteristics and parametric optimum criteria of a nano-thermoelectric refrigerator with an external magnetic field

    International Nuclear Information System (INIS)

    In the paper, we describe a single-level quantum dot with an external magnetic field that works as a nano-thermoelectric refrigerator. Based on the model, the expressions for the cooling rate (R), the power input (P) and the coefficient of performance (ε) are derived. The effects of the magnetic field strength and the level energy on the performance of the refrigerator are revealed. The optimal performance characteristics of the refrigerator are analyzed by numerical calculation. Furthermore, the practical operating regions of the cycle are determined.

  15. Cryogen-free dilution refrigerator for bolometric search of neutrinoless double beta decay (0 ) in 124Sn

    Indian Academy of Sciences (India)

    V Singh; S Mathimalar; N Dokania; V Nanal; R G Pillay; S Ramakrishnan

    2013-10-01

    The feasibility study for searching neutrinoless double beta decay in 124Sn using cryogenic bolometer has been initiated. For this purpose, a custom-built cryogen-free dilution refrigerator, having a large cooling power of 1.4 mW at 120 mK, has been installed at TIFR, India. This paper describes the design, installation and performance of a cryogen-free dilution refrigerator (CFDR-1200). The performance of CFDR-1200 has been analysed using Takano’s model developed for conventional (wet) dilution refrigerators.

  16. 2015 German refrigeration and air conditioning meeting. Abstracts

    International Nuclear Information System (INIS)

    The volume contains the abstracts of the 2015 German refrigeration and air conditioning meeting in 5 chapters: cryo-technology, fundamentals of materials for refrigeration engineering and heat pump technology, facilities and components for the refrigeration and heat pump technology; application of refrigeration engineering; air conditioning technology and heat pump application.

  17. 46 CFR 58.20-15 - Installation of refrigerating machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Installation of refrigerating machinery. 58.20-15... AND AUXILIARY MACHINERY AND RELATED SYSTEMS Refrigeration Machinery § 58.20-15 Installation of refrigerating machinery. (a) Where refrigerating machines are installed in which anhydrous ammonia is used as...

  18. 46 CFR 151.40-11 - Refrigeration systems.

    Science.gov (United States)

    2010-10-01

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

  19. Instability of refrigeration system - A review

    International Nuclear Information System (INIS)

    It is essential to ensure the stability for the normal operation of refrigeration systems. This paper reviews the researches on the theory and solutions of the instability of refrigeration systems. The instability of refrigeration systems includes two aspects: the two-phase flow instability in refrigeration system, the instability on refrigeration system control characteristics. As an inherent characteristic of two-phase evaporating flow, several separate explanations for the formation of oscillation of mixture-vapor transition point in the evaporation process by different scholars had been given but there is no general explanation till now. The investigation of instability on refrigeration system control characteristics focused on both static and dynamic researches. The minimum stable signal line theory, as a very important finding for the static instability of the evaporator and thermal expansion valve control loop, presented the different result to other researches. Dynamic researches on simulation and frequency-domain analysis provided various means for forecast and validation with considerable precision while their application range was still confined. With the development of variable capacity compressor and electronic expansion valve, further researches should be carried out to analyze the instability of the variable capacity refrigeration system with considering the influence of parameter coupling and control algorithm.

  20. A resorption refrigerator driven by low grade thermal energy

    Energy Technology Data Exchange (ETDEWEB)

    Bao, H.S. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, R.Z., E-mail: rzwang@sjtu.edu.c [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China); Wang, L.W. [Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2011-06-15

    Highlights: {yields} A resorption refrigerator employing MnCl{sub 2}-NH{sub 3} and NH{sub 4}Cl-NH{sub 3} was designed and investigated. {yields} The experiments were operated under different ambient temperatures from 20 to 35 {sup o}C. {yields} The refrigerator provided simultaneously two cooling levels: at 0-6 {sup o}C and at -16 {approx} -14.5 {sup o}C. {yields} With 3 h operation the total cooling capacity was 475 kJ per kg of NH{sub 4}Cl salt. {yields} The effective cooling production was 25-42% of the total cooling capacity. -- Abstract: A small refrigerator based on resorption technique, employed MnCl{sub 2} and NH{sub 4}Cl as sorbent salts and ammonia as refrigerant, was presented for simultaneously cooling at 0-6 {sup o}C and freezing at -16 to -14.5 {sup o}C in this work. The cooling capacity of this device was investigated by measuring the mass amount of the ice generated during a certain period of 3 h operation, and the experiments were conducted at different ambient temperature ranging from 20 {sup o}C to 35 {sup o}C. The total cooling capacity was calculated 475 kJ per kg of NH{sub 4}Cl salt, and the mean specific cooling power (SCP) was 43 W per kg of NH{sub 4}Cl salt, the effective cooling production responsible for making ice accounted for 25-42% of the total cooling capacity depending on the different operating conditions studied in this work.

  1. Quantum-enhanced absorption refrigerators

    CERN Document Server

    Correa, Luis A; Alonso, Daniel; Adesso, Gerardo

    2014-01-01

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

  2. Quantum refrigerator driven by current noise

    CERN Document Server

    Chen, Yi-Xin

    2011-01-01

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

  3. A versatile magnetic refrigeration test device.

    Science.gov (United States)

    Bahl, C R H; Petersen, T F; Pryds, N; Smith, A

    2008-09-01

    A magnetic refrigeration test device has been built and tested. The device allows variation and control of many important experimental parameters, such as the type of heat transfer fluid, the movement of the heat transfer fluid, the timing of the refrigeration cycle, and the magnitude of the applied magnetic field. An advanced two-dimensional numerical model has previously been implemented in order to help in the optimization of the design of a refrigeration test device. Qualitative agreement between the results from model and the experimental results is demonstrated for each of the four different parameter variations mentioned above. PMID:19044427

  4. 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

  5. A versatile magnetic refrigeration test device

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  6. New refrigeration system using CO2 vapor-solid as refrigerant

    Institute of Scientific and Technical Information of China (English)

    Dongping HUANG; Guoliang DING; Hans QUACK

    2008-01-01

    A refrigerant must be in the vapor-liquid phase in a vapor-compression refrigeration system, therefore, CO2 cannot be used as a refrigerant for temperatures lower than -56℃ because solid CO2 will form under the triple point temperature of -56℃. A refrigeration system with CO2 vapor-solid particles as refrigerant is put forward, by which a temperature lower than the triple point is achieved. An adjustable nozzle, a sublimator, a high-pressure regulating valve and a low-pressure regulat-ing valve are used to replace the conventional evaporator. Theoretical cycle analysis of the refrigeration system shows that its COP can be 50% higher than that of the conventional one.

  7. SECONDARY FLUIDS USED IN INDIRECT REFRIGERATION SYSTEMS IN SWEDEN

    OpenAIRE

    Salom Munoz, Patrick Javier

    2015-01-01

    Interest in indirect (secondary) refrigeration systems has grown since the discovery of the negative effect of environmentally hazardous refrigerants and leakage problems from direct expansion systems. Among the positive effects of indirect systems are: decreased quantities of primary refrigerant, factory built units and confinement of refrigerant to the machine room. Ground source heat pumps, ice rink and indirect system solutions for supermarket refrigeration are examples where indirect ref...

  8. 2014 German refrigeration and air conditioning meeting. Proceedings

    International Nuclear Information System (INIS)

    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.

  9. Comparative Analysis of Various Condenser in Vapour Compression Refrigeration System

    OpenAIRE

    Patil Deepak P.

    2014-01-01

    The present work is to analyze performance of refrigeration system on three condensers viz. micro-channel, round tube and coil tube using R134a and R290 refrigerants. These three condensers are kept in parallel with other components of refrigerating unit while construction.The performance of refrigeration system is checked for each condenser at various cooling loads in the range from 175 W to 288 W.The performance of the condenser is measured for whole refrigeration unit in te...

  10. Health effects among refrigeration repair workers exposed to fluorocarbons.

    OpenAIRE

    Campbell, D D; Lockey, J E; Petajan, J; Gunter, B J; Rom, W N

    1986-01-01

    Refrigeration repair workers may be intermittently exposed to fluorocarbons and their thermal decomposition products. A case of peripheral neuropathy (distal axonopathy) in a commercial refrigeration repairman prompted an epidemiological investigation of the health of refrigeration repair workers. No additional cases of peripheral neuropathy were identified among the 27 refrigeration repair workers studied. A reference group of 14 non-refrigeration repair workers was also studied. No differen...

  11. Performance of a domestic refrigerator using TiO{sub 2}-R600a nano-refrigerant as working fluid

    Energy Technology Data Exchange (ETDEWEB)

    Shengshan Bi; Kai Guo; Zhigang Liu; Jiangtao Wu [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an Shaanxi 710049 (China)

    2011-01-15

    In this work, an experimental work was investigated on the nano-refrigerant. TiO{sub 2}-R600a nano-refrigerants were used in a domestic refrigerator without any system reconstruction. The refrigerator performance was then investigated using energy consumption test and freeze capacity test. The results indicate that TiO{sub 2}-R600a nano-refrigerants work normally and safely in the refrigerator. The refrigerator performance was better than the pure R600a system, with 9.6% less energy used with 0.5 g/L TiO{sub 2}-R600a nano-refrigerant. Thus, using TiO{sub 2}-R600a nano-refrigerant in domestic refrigerators is feasible. (author)

  12. Performance of a domestic refrigerator using TiO{sub 2}-R600a nano-refrigerant as working fluid

    Energy Technology Data Exchange (ETDEWEB)

    Bi Shengshan, E-mail: bss@mail.xjtu.edu.c [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an Shaanxi 710049 (China); Guo Kai; Liu Zhigang; Wu Jiangtao [State Key Laboratory of Multiphase Flow in Power Engineering, Xi' an Jiaotong University, Xi' an Shaanxi 710049 (China)

    2011-01-15

    In this work, an experimental work was investigated on the nano-refrigerant. TiO{sub 2}-R600a nano-refrigerants were used in a domestic refrigerator without any system reconstruction. The refrigerator performance was then investigated using energy consumption test and freeze capacity test. The results indicate that TiO{sub 2}-R600a nano-refrigerants work normally and safely in the refrigerator. The refrigerator performance was better than the pure R600a system, with 9.6% less energy used with 0.5 g/L TiO{sub 2}-R600a nano-refrigerant. Thus, using TiO{sub 2}-R600a nano-refrigerant in domestic refrigerators is feasible.

  13. Simulation of the Energy Saver refrigeration system

    International Nuclear Information System (INIS)

    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

  14. Intra-molecular refrigeration in enzymes

    CERN Document Server

    Briegel, Hans J

    2009-01-01

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

  15. Designing a magnet for magnetic refrigeration

    DEFF Research Database (Denmark)

    Bjørk, Rasmus

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

  16. Exergetic sustainability evaluation of irreversible Carnot refrigerator

    Science.gov (United States)

    Açıkkalp, Emin

    2015-10-01

    Purpose of this paper is to assess irreversible refrigeration cycle by using exergetic sustainability index. In literature, there is no application of exergetic sustainability index for the refrigerators and, indeed, this index has not been derived for refrigerators. In this study, exergetic sustainability indicator is presented for the refrigeration cycle and its relationships with other thermodynamics parameters including COP, exergy efficiency, cooling load, exergy destruction, ecological function and work input are investigated. Calculations are conducted for endoreversible and reversible cycles and then results obtained from the ecological function are compared. It is found that exergy efficiency, exergetic sustainable index reduce 47.595% and 59.689% and rising at the COP is 99.888% is obtained for endoreversible cycle. Similarly, exergy efficiency and exergetic sustainability index reduce 90.163% and 93.711% and rising of the COP is equal to 99.362%.

  17. 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.

  18. Intra-molecular refrigeration in enzymes

    OpenAIRE

    Briegel, H. J.; Popescu, S.

    2013-01-01

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

  19. ENERGY STAR Certified Commercial Refrigerators and Freezers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Commercial Refrigerators and Freezers that are...

  20. REFRIGERATION ESPECIALLY FOR VERY LOW TEMPERATURES

    Science.gov (United States)

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

    1960-09-13

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