Experimental Investigation of the Performance of an R1270/CO2 Cascade Refrigerant System

Abstract Herein, we proposed a cascade refrigerant system with R1270 and carbon dioxide refrigerants. The natural refrigerant R1270 was adopted in the high-temperature circuit to replace NH3 and R290. A prototype cascade refrigerant system with two semi-hermetic piston compressors was manufactured, and its performance was investigated experimentally. The results establish R1270 as a good alternative in the high-temperature circuit of the cascade refrigerant system. Moreover, with a constant condensation and evaporation temperature of cascade system, as the R1270 evaporation temperature was decreased (from −7 °C to −19 °C), the coefficient of performance(COP) of the cascade system increased. The isentropic efficiency of R1270 compressor decreased from 78.5% to 74.7% when the R1270 evaporation temperature increased from −19 °C to −7 °C.