The Experts below are selected from a list of 106827 Experts worldwide ranked by ideXlab platform
Lin Wang - One of the best experts on this subject based on the ideXlab platform.
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Performance Analysis of Solar-Assisted Refrigeration Cycle
Applied Mechanics and Materials, 2012Co-Authors: Lin Wang, Shuang Ping DuanAbstract:Energy-conservation and environmental protection are keys to sustainable development of domestic economy. The solar-assisted cascade Refrigeration cycle system is developed. The system consists of electricity-driven vapor compression Refrigeration system and solar-driven vapor absorption Refrigeration system. The vapor compression Refrigeration system is connected in series with vapor absorption Refrigeration system. Refrigerant and solution reservoirs are designed to store potential to keep the system operating continuously without sunlight. The results indicate that the system obtains pretty higher COP as compared with the conventional vapor compression Refrigeration system. COP of the new-type vapor compression Refrigeration system increases as sunlight becomes intense.
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study on solar assisted cascade Refrigeration system
Energy Procedia, 2012Co-Authors: Lin WangAbstract:Abstract Energy-conservation and environmental protection are keys to sustainable development of domestic economy. The solar-assisted cascade Refrigeration system is developed. The system consists of electricity-driven vapor compression Refrigeration system and solar-driven vapor absorption Refrigeration system. The vapor compression Refrigeration system is connected in series with vapor absorption Refrigeration system. Refrigerant and solution reservoirs are designed to store potential to keep the system operating continuously without sunlight. The results indicate that the system obtains pretty higher COP as compared with the conventional vapor compression Refrigeration system. COP of the new-type vapor compression Refrigeration system increases as sunlight becomes intense.
Damola S Adelekan - One of the best experts on this subject based on the ideXlab platform.
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Exergy analysis of vapor compression Refrigeration system using R450A as a replacement of R134a
Journal of Thermal Analysis and Calorimetry, 2019Co-Authors: Jatinder Gill, Olayinka S. Ohunakin, Jagdev Singh, Damola S AdelekanAbstract:This paper experimentally investigated exergetic performance analysis of vapor compression Refrigeration system using R450a as a replacement for R134a at different evaporator and condenser temperatures within controlled environmental conditions. The exergetic performance analysis of the vapor compression Refrigeration system with test parameters including efficiency defects in the components, total irreversibility, and exergy efficiency of the Refrigeration system was performed. Findings showed that the total irreversibility and exergy efficiency of the vapor compression Refrigeration system using R450A refrigerant were lower and higher than R134a by about 15.25–27.32% and 10.07–130.93%, respectively. However, the efficiency defect in the condenser, compressor, and evaporator of the R450A Refrigeration system was lower than R134a by about 16.99–26.08%, 5.03–20.11%, and 1.85–15.85%, respectively. Conversely, efficiency defect in the capillary tube of the R450A Refrigeration system was higher than R134a by about 14.66–78.97% under similar operating conditions. Overall, it was found that the most efficient component was the evaporator, and the least efficient component was the compressor for both refrigerants.
F R De Boer - One of the best experts on this subject based on the ideXlab platform.
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transition metal based magnetic refrigerants for room temperature applications
Nature, 2002Co-Authors: O Tegus, E Bruck, K H J Buschow, F R De BoerAbstract:Magnetic Refrigeration techniques based on the magnetocaloric effect (MCE) have recently been demonstrated as a promising alternative to conventional vapour-cycle Refrigeration1. In a material displaying the MCE, the alignment of randomly oriented magnetic moments by an external magnetic field results in heating. This heat can then be removed from the MCE material to the ambient atmosphere by heat transfer. If the magnetic field is subsequently turned off, the magnetic moments randomize again, which leads to cooling of the material below the ambient temperature. Here we report the discovery of a large magnetic entropy change in MnFeP0.45As0.55, a material that has a Curie temperature of about 300 K and which allows magnetic Refrigeration at room temperature. The magnetic entropy changes reach values of 14.5 J K-1 kg-1 and 18 J K-1 kg-1 for field changes of 2 T and 5 T, respectively. The so-called giant-MCE material Gd5Ge2Si2 (ref. 2) displays similar entropy changes, but can only be used below room temperature. The refrigerant capacity of our material is also significantly greater than that of Gd (ref. 3). The large entropy change is attributed to a field-induced first-order phase transition enhancing the effect of the applied magnetic field.
Peixue Jiang - One of the best experts on this subject based on the ideXlab platform.
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hybrid vapor compression Refrigeration system with an integrated ejector cooling cycle
International Journal of Refrigeration-revue Internationale Du Froid, 2012Co-Authors: Peixue JiangAbstract:Abstract A Refrigeration system was developed which combines a basic vapor compression Refrigeration cycle with an ejector cooling cycle. The ejector cooling cycle is driven by the waste heat from the condenser in the vapor compression Refrigeration cycle. The additional cooling capacity from the ejector cycle is directly input into the evaporator of the vapor compression Refrigeration cycle. The governing equations are derived based on energy and mass conservation in each component including the compressor, ejector, generator, booster and heat exchangers. The system performance is first analyzed for the on-design conditions. The results show that the COP is improved by 9.1% for R22 system. The system is then compared with a basic Refrigeration system for variations of five important variables. The system analysis shows that this Refrigeration system can effectively improve the COP by the ejector cycle with the refrigerant which has high compressor discharge temperature.
Milan N. Šarevski - One of the best experts on this subject based on the ideXlab platform.
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Ejector Refrigeration/Heat Pump Systems
Water (R718) Turbo Compressor and Ejector Refrigeration Heat Pump Technology, 2020Co-Authors: Milan N. Šarevski, Vasko N. ŠarevskiAbstract:A comprehensive review of the investigations of ejector Refrigeration/heat pump cycles is presented in this chapter. Thermal and performance characteristics of simple and combined ejector Refrigeration systems, heat pumps, cogenerative, and polygenerative systems are investigated in conditions where low-temperature heat (solar energy, waste heat, geothermal energy) is used. The ejector systems are technically and economically viable and competitive in comparison with conventional Refrigeration systems. Viability of implementation of two-phase ejectors in compressor Refrigeration systems for reduction of the throttling losses depends on the refrigerant thermodynamic properties, Refrigeration cycle operating conditions as well on the degree to which the two-phase ejector flow field has been optimally designed. The experiences and results of these investigations are valuable for creating the concepts and developmental strategies for novel Refrigeration cycles with two-phase ejectors. A novel water (R718) two-phase ejector Refrigeration cycle is proposed and its thermal and performance characteristics are estimated.
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Chapter 1 – Introductory Concepts
Water (R718) Turbo Compressor and Ejector Refrigeration Heat Pump Technology, 2020Co-Authors: Milan N. ŠarevskiAbstract:This chapter introduces the subjects of the book, namely water turbo compressor Refrigeration and heat pump systems, water ejector Refrigeration and heat pump systems, and combined compressor–ejector Refrigeration and heat pump systems. Brief descriptions of each chapter are provided. A history of waterbased turbo compressor and ejector Refrigeration and heat pump techology is provided, as well as a look forward at future potential of these systems.
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Water (R718) Turbo Compressor Refrigeration/Heat Pump Systems
Water (R718) Turbo Compressor and Ejector Refrigeration Heat Pump Technology, 2020Co-Authors: Milan N. Šarevski, Vasko N. ŠarevskiAbstract:R718 centrifugal Refrigeration/heat pump systems are investigated to determine optimal schematic structure, to estimate performance characteristics, and to provide possibilities for wider application in the field of air-conditioning. Deep vacuum operating conditions, low specific volumetric cooling capacity, small molecular mass, and high isentropic exponent of the water are peculiarities which determine the main parameters of centrifugal compressors and the range of rational application of R718 Refrigeration/heat pump systems. High impeller peripheral speed, high Mach number, low Reynolds number, large dimensions, and high superheating at the compressor discharge are the features of R718 centrifugal Refrigeration compressors. A two-stage centrifugal compressor and, respectively, two-stage Refrigeration cycle are optimal technical solutions for Refrigeration systems in the field of air-conditioning applications. Direct flash evaporation and condensation provide simplicity and the possibility of achieving a high COP. A comparison shows that R718 centrifugal Refrigeration systems are competitive with traditional Refrigeration systems.
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Chapter 6 – Ejector Refrigeration/Heat Pump Systems
Water (R718) Turbo Compressor and Ejector Refrigeration Heat Pump Technology, 2016Co-Authors: Milan N. Šarevski, Vasko N. ŠarevskiAbstract:A comprehensive review of the investigations of ejector Refrigeration/heat pump cycles is presented in this chapter. Thermal and performance characteristics of simple and combined ejector Refrigeration systems, heat pumps, cogenerative, and polygenerative systems are investigated in conditions where low-temperature heat (solar energy, waste heat, geothermal energy) is used. The ejector systems are technically and economically viable and competitive in comparison with conventional Refrigeration systems. Viability of implementation of two-phase ejectors in compressor Refrigeration systems for reduction of the throttling losses depends on the refrigerant thermodynamic properties, Refrigeration cycle operating conditions as well on the degree to which the two-phase ejector flow field has been optimally designed. The experiences and results of these investigations are valuable for creating the concepts and developmental strategies for novel Refrigeration cycles with two-phase ejectors. A novel water (R718) two-phase ejector Refrigeration cycle is proposed and its thermal and performance characteristics are estimated.
