First and Second Law Analysis of Cascade Refrigeration System Using Refrigerant Pair R744-R1234ze(E)

Abstract

— The performance of a two stage cascade refrigeration system using environment friendly refrigerant pair R744 in low temperature cycle and R1234ze(E) in high temperature cycle has been examined by mathematical simulation in EES ( Engineering Equation Solver). The operating parameters considered in this study are evaporator temperature and condenser temperature. The results shows that with increase in condenser temperature, total exergy loss is increasing and total COP is decreasing. The similar effect has been seen with increase with evaporator temperature but rate of increase of total exergy loss and rate of decrease of total COP with evaporator temperature is low.