Thermodynamic analysis of absorption refrigeration system (ARS)

Absorption refrigeration system (ARS) continuously shows a growing interest in many applications due to cheap energy consumption and environmental friendly system. Typically, ARS system uses ammonia-water mixture where ammonia as refrigerant and water as absorbent. The system also consist hydrogen a...

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Bibliographic Details
Main Author: Hau, Ong Boon
Format: Undergraduates Project Papers
Language:English
Published: 2010
Subjects:
Online Access:http://umpir.ump.edu.my/id/eprint/3261/
http://umpir.ump.edu.my/id/eprint/3261/1/CD5839_Ong_Boon_Hau.pdf
Description
Summary:Absorption refrigeration system (ARS) continuously shows a growing interest in many applications due to cheap energy consumption and environmental friendly system. Typically, ARS system uses ammonia-water mixture where ammonia as refrigerant and water as absorbent. The system also consist hydrogen as auxiliary inert gas. While in this research, it is operated by using liquefied petroleum gas (LPG) and electricity as sources of heat. From the various publications recently, despite the ARS system attract many interests, it is still need to further analyze system’s thermodynamic for better process understanding and improvement. Hence, the purpose of this research are to investigate thermodynamically the Coefficient of Performance (COP), Carnot Coefficient or heat transfer rate (COPC), Efficiency Ratio (δ) and exergy loss of each component in the system. Temperature surrounding is important data in this research are measured to determine all of the thermodynamic analysis highlighted using published equations. From the results, it is found that the ARS using LPG is higher of about 18 percent compared to electricity where surrounding temperature is the lowest which is during morning condition. Electricity supplied to the ARS in the case at 5 for the thermostat reading. The result of COPC is basically follow COP’s results in all cases. For efficiency ratio (δ), which a comparative efficiency between COP and COPC show that the higher the value, the better process performance or the closer to the ideal value. Finally, exergy loss for both heat sources found to be highest value of 283185.2 kJ/g at evaporator as compared to other equipment in the ARS system. In conclusion, the higher COP and COPC can be obtained in the system is by using LPG as a heat source instead of using the electricity with the thermostat in the morning condition. This is because the LPG provides direct heating to the boiler and less resistance occurs during the process as compared to electricity and also due to the fact that thermal load are low during morning condition. As a result, cooling effect from ARS is better for the lower surrounding temperature. Exegy loss is found to be higher in evaporator by using LPG instead of electricity. It is recommended that renewable energy such as biomass and solar energy as a heat sources to the ARS system. This is because this energy is already available and can be utilised for better thermodynamic efficiency of any ARS application. Besides that, costing and economic analysis need to be addressed in order to make a quantitatively measure the energy saving and cost reduction.