Experimental study of the refrigeration cycle performance for the R744/R290 mixtures

A new binary mixture of R744 and R290 as an alternative natural refrigerant to R13 was first presented in this paper. Its environmental performance is friendly. It has an ODP of zero and GWP smaller than 20. Experimental studies for this mixture and R13 were performed on a cascade refrigeration system only with modification to capillary in low-temperature circuit. COP and refrigeration capacity of this binary mixture were higher than those of R13, at the same time, condensing pressure, evaporating pressure, compression ratio, and discharge temperature were also higher than that of R13 when the high-temperature circuit of cascade refrigeration system was kept invariable. The new binary mixture of R744 and R290 is considered as a promising alternative refrigerant to R13 when the evaporator temperature is higher than 201 K.