Theoretical performances of various refrigerant–absorbent pairs in a vapor-absorption refrigeration cycle by the use of equations of state

2005 ◽  
Vol 80 (4) ◽  
pp. 383-399 ◽  
Author(s):  
A. Yokozeki
Keyword(s):  
Equations Of State ◽  
Refrigeration Cycle ◽  
Absorption Refrigeration ◽  
Vapor Absorption ◽  
Vapor Absorption Refrigeration

Performance Analysis of Solar-Assisted Refrigeration Cycle

2012 ◽  
Vol 170-173 ◽  
pp. 2504-2507
Author(s):  
Lin Wang ◽  
Shuang Ping Duan ◽  
Xiao Long Cui
Keyword(s):  
Refrigeration Cycle ◽  
Vapor Compression ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Cycle System ◽  
Vapor Absorption ◽  
In Series ◽  
Vapor Compression Refrigeration ◽  
Absorption Refrigeration System ◽  
Vapor Absorption Refrigeration

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.

EXERGY ANALYSIS OF A LiBr–H2O VAPOR ABSORPTION REFRIGERATION PLANT: A CASE STUDY

2014 ◽  
Vol 22 (02) ◽  
pp. 1450010 ◽  
Author(s):  
SANJEEV ANAND ◽  
ANKUSH GUPTA ◽  
SUDHIR KUMAR TYAGI
Keyword(s):  
Performance Optimization ◽  
Exergy Analysis ◽  
Heat Rate ◽  
Exergy Efficiency ◽  
Exergy Loss ◽  
Absorption Refrigeration ◽  
Actual System ◽  
Evaporator Temperature ◽  
Vapor Absorption ◽  
Vapor Absorption Refrigeration

This communication presents the energy and exergy analysis of an actual double effect steam powered LiBr – H 2 O vapor absorption refrigeration plant. Exergy loss, COP, exergy efficiency and heat rate for each component of the system are calculated. The effect of generator as well as evaporator temperature on the COP and exergy efficiency is evaluated and it is found that the irreversibility rate is highest in the generator while it is found to be the lowest in the case of absorber and condenser. It is also found that the COP of the system increases with the increase in the evaporator temperature while it is found to be reverse in case of exergy efficiency. Results revealed that average exergy loss is highest in the generator as compared to other components. The results obtained are helpful for designers to bring changes in the actual system for performance optimization and less wastage of energy. The study clearly explain the operational and maintenance problems in the machine and point out the areas of energy wastage which the operational engineer should look into for the optimum operation of the plant.

Space Cooling Using the Concept of Nanofluids-Based Direct Absorption Solar Collectors

2012 ◽  
Author(s):  
Vivek Vishwakarma ◽  
Nitin Singhal ◽  
Vikrant Khullar ◽  
Himanshu Tyagi ◽  
Robert A. Taylor ◽  
...  
Keyword(s):  
Solar Collector ◽  
Air Conditioning ◽  
Thermal Storage ◽  
Temperate Climate ◽  
Absorption Refrigeration ◽  
Direct Absorption ◽  
Parabolic Trough ◽  
Space Cooling ◽  
Vapor Absorption ◽  
Vapor Absorption Refrigeration

A solar-energy based vapor absorption refrigeration system is potentially an excellent alternative air-conditioning system. However, there are several research challenges to ensure sufficient efficiency and reliability for ensuring widespread implementation. Integration of a parabolic trough solar collector utilizing a mixture of nanoparticles and water with a vapor absorption system has the potential to significantly enhance the efficiency of the system. Such a system makes use of the superior thermo-physical properties of the nanofluid compared to the base fluid. Moreover, the direct absorption phenomenon of solar radiation through interaction with the participating medium (nanofluid) results in a higher temperature rise of the medium in conjunction with higher operating efficiencies as well. At the same time there are certain challenges that need to be identified and addressed in the implementation of this novel concept. For instance, to make it reliable, the system further needs to be integrated with a thermal storage system which facilitates air-conditioning even during non-sunshine hours. Integration of vapor absorption refrigeration technology, parabolic trough with water-nanoparticles mixture as the absorbing medium and a thermal storage facility is the uniqueness of this design which under certain conditions and locations may prove to be an efficient and reliable substitute to the conventional electrical air-conditioning systems. In this particular study a space cooling application for approximately 100 Tons of refrigeration is studied. Hourly variation in sunlight as well as seasonal changes for temperate climate conditions is considered. Parameters such as the cooling load of the space, and waste heat produced by electronics are evaluated. The cooling system driven by the nanofluid-based concentrated parabolic solar collector is mathematical modeled and then the optimization is done by varying the nanoparticle size and volume fraction in order to obtain the best result for collector outlet temperature, thermal efficiency and optical efficiency.

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