Cascade refrigeration systems are used for very low temperature applications where the desired temperatures are in range of -30 °C to -80 °C. The objective of this project is to design and develop a two stage cascade refrigeration system using R404 and R22 as refrigerants. R404and R22 are selected for this study as the high temperature and low temperature refrigerant respectively. The design of major components including the cascade condenser, the tube in tube heat exchanger and the LTC evaporator is carried out. A fully instrumented experimental facility has been created to carry out detailed experimentation on two stage cascade systems. Air cooled condenser of split window air conditioner is taken as the 1 1TC condenser. The cascade condenser is designed as a flooded shell and tube heat exchanger, while LTC evaporator is a fin and tube type heat exchanger. The LTC evaporator and cascade condenser are hydraulically tested at pressures of 120 bar. The instrumentation is connected to a data acquisition system for continuous recording and monitoring of data.
Keywords: Cascade, compressor, condenser, evaporator, tube in tube heat exchanger accumulator, Drier filter.