Optimum Performance Analysis of a Hybrid Cascade Refrigeration System Using Alternative Refrigerants

This research article deals with a Hybrid cascade refrigeration system (HCRS) comprising of vapor absorption refrigeration system (VARS) at the top or high temperature stage and vapor compression refrigeration system (VCRS) at the bottom or low temperature stage in a two-stage cascade refrigeration system using a mathematical model for energy and exergy analysis. The theoretical analysis is carried out taking H2O-LiBr solution in VARS and R134a, R32, R1234yf in VCRS as refrigerants. The three refrigerants (R134a, R32 and R1234yf) in this study are selected because these refrigerants have been recommended as future alternative refrigerants due to their zero ODP and low GWP properties. It has been found that the optimum generator temperature of HCRS is same for all the three eco-friendly refrigerants at which maximum coefficient of performance (COP) and maximum exergetic efficiency occurs. Further it is observed that the performance of the system considered in the study is better with R134a in comparison to R32 and R1234yf as refrigerants in the VCRS and R32 exhibits better result when compared with R1234yf.