SECOND LAW ANALYSIS OF DIFFERENT REFRIGERANTS IN A TWO STAGE VAPOR COMPRESSION CYCLE

In this study, the second law analysis has been made by means of the program developed using the software program EES (EES-V9.172-3D) in a two stage vapor-compression refrigeration cycle for the refrigerants such as R600 (butane), R290 (propane), R152a (HFC) and R141b (HCFC) as refrigerants. It has been assumed that superheating and subcooling occur in the system and the calculations have been made accordingly. Irreversibilities occurring in the components of the cycle including compressors, evaporator, condenser, expansion valve and flash tank have been examined for different evaporator and condenser temperatures. As the condenser temperatures were increased, the irreversibilities of the components increased while they decreased with the increase of evaporator temperatures. The minimum irreversibility values occurred in the flash tank for all the refrigerants under the study. Furthermore, at the increasing values of evaporator temperatures, the total irreversibility of the refrigeration system decreased, but it increased with the condenser temperature. The total lowest irreversibility values are obtained by using R141b as a refrigerant in the refrigeration system for the increasing values of the condenser and evaporator temperature