Use of R290/R170 in Lieu of R22/R23 in Cascade Refrigeration Cycles 1.0.0

ABSTRACT

R22/R23 have been predominantly used in cascade refrigeration cycles. Even though the ODP of R22 is not as high as CFCs, it still will be phased out following the Montreal Protocol and its amendments because of the chlorine atoms. Hydrocarbons, such as R170 and R290 are natural working fluids. Thermodynamic analysis on the cascade refrigeration cycle adopted R290/R170 under the evaporation temperature from -80 to -55 and the condensation temperature from 30 to 40 are processed. System performances, such as the maximum COP, the cascade evaporating temperature, the ratio of refrigerants flow rate between high and low temperature circuits and their variations are compared with that of the R22/R23 under the same conditions. Results show that the performances of the two cascade refrigeration cycle are approximately the same. So the R290/R170 can be used as the substituting refrigerants to R22/R23 in the cascade refrigeration cycle.