Vapor Absorption Vs Vapor Compression Refrigeration

 

There are some aspects in which vapor absorption refrigeration system is different from that of vapor compression. The main principle is the same for the two systems. But there are differences between power consumption COP, mechanical parts etc.

Comparison between vapor absorption and vapor compression refrigeration systems

S.no	Aspect	Vapor Absorption System	Vapor Compression System
1	Quality of the Energy Input	Low grade energy sources are more than capable of running a vapor absorption system. These sources can be waste heat from furnaces, exhauststeam etc. Solar power can also be used for running it.	Vapor compression system needs high grade energy. It needs electrical or mechanical energy for operating compressor which is an essential part of VC refrigeration system.
2	Moving part in the system	The only moving part of Vapor absorption refrigeration system is the pump.	In Vapor compression the moving part is the compressor which operated by electric motoror engine .
3	Effect of Evaporatorpressure	Very little effect is seen in the refrigeration capacity with the lowering evaporatorpressure.	The refrigerating effect or refrigeration capacity decreases with the lowering evaporatorpressure.
4	Workability at Load varying load	Load Variation does not have any effect on the performance of the vapor absorption system	Vapor compression system does not work well at partial load. The performance is very poor.
5	Evaporatorexit	In vapor absorption system, if the liquid refrigerant leaves the evaporator, the refrigerating effect is reduced but the system functions well without any problem.	Liquid refrigerant entering compressor is not desirable in Vapor compression system. It could damagethe compressor. So the refrigerant is superheated before leaving the evaporator.
6	Lowest temperature	When water is used as refrigeration the temperature attained is above 0 degreeCelsius	-150 degree Celsius or even lower can be achieved with the cascading system.
7	Coefficientof Performance	The COP of absorption refrigeration system is poor.	The COP of Vapor compression system is very good.
8	Capacity	Capacity above 1000 TR is easily achievable.	It is difficult to capacity above 1000 TR with single compression system.
9	Refrigerant	Ammonia or water can be used as refrigerant with a proper absorber.	Hydrocarbons, Chlorofluorocarbons and Hydrochlorofluorocarbons are used as refrigerations.