INVESTIGATION OF IRREVERSIBILITIES IN THE COMPRESSION PROCESS FOR ALTERNATIVE REFRIGERANTS IN A VAPOR COMPRESSION REFRIGERATION CYCLE

摘要

Irreversibility analyses during compression process are presented for some refrigerants namely, R290, R134a, R12, R22, and R152a in a vapor compression refrigeration cycle. The effects of evaporator temperature, condenser temperature and isentropic efficiency on the irreversibility rates and exergetic efficiencies of the refrigerants under study are investigated By the means of a computer code that simulates a vapor compression cycle including subcooling and superheating. For all the refrigerants in this study, the irreversibility in the compression process decreased as the evaporator temperature and isentropic efficiency increased and it increased with the increasing values of the condenser temperatures. Exergetic efficiency of the compressor increased as the isentropic efficiency of the compressor increased while it decreased with the increasing values of evaporator temperatures. In the case of increasing evaporator and condenser temperatures, and isentropic efficiency values, R22 and R152a approximately show the same and lowest values of compressor irreversibility while R290 has the lowest values. The compressor irreversibilities and compressor exergetic efficiencies of R12 and R134a placed in the moderate range in the case of increasing evaporator and condenser temperatures, and isentropic efficiency values.