Experimental and Simulation Studies of R134a-R404a Cascade Refrigeration System

Abstract - A single stage refrigeration system is in-efficient while operating at temperatures below -300C. Hence for low temperatures a cascade refrigeration system is used. The present work consists of experimental and simulation studies of a R134a-R404a cascade refrigeration system. Experiments are carried out on a developed system to obtain its performance by varying evaporating temperature with an heater input load. Further mathematical modelling of system is done and system is simulated and validated with experimental results. Parametric study is done, at various temperatures, by varying the UA values of heat exchanger. It is observed that the performance of the cascade condenser, a shell and coil type, has significant impact on the system. The performance of the system is evaluated by at various heat transfer areas of the cascade condenser. The system of is then simulated by replacing the shell and coil type heat exchanger with a plate heat exchanger. It is observed that the system shows much better performance with use of Plate Heat Exchanger.