Performance Evaluation of Ecofriendly Refrigerants in the Low Temperature Circuit in Terms of First Law and Second Law Efficiency of Three Stages Cascade Vapour Compression Refrigeration of Biomedical Applications

Biomedical preservation requires storing biological specimens like stem cells blood and organs, at a storage temperature below -95oC. ,Hence, the main aim of the current research is to conduct a thermodynamic energy and exergy analysis to determine the thermal performance of three stages / four stages cascade refrigeration systems in the high temperature condenser temperature of 70oC using R1234ze and R1234yf in high temperature circuit and varying evaporator temperature (-20 oC to 10oC) in High temperature circuit, Varying evaporator temperature in first intermediate evaporator temperature (-70oC to -90oC) circuit using R134a and R410a as ecofriendly refrigerants is investigated. For low temperature evaporator temperature( -145oC to -100 oC) using hydrocarbons (R290, R600 and R600a) , R404a and other refrigerants in low temperature evaporator circuit on system performances (i.e. overall system coefficient of performance, (first law efficiency), exergetic efficiency (second law efficiency) and system exergy destruction ratio (EDR) is investigated in three stages /four stages cascade refrigeration systems are shown in this paper