Theoretical study of low-GWP refrigerants in high-temperature heat pump systems

Abstract

Abstract In this paper, the thermal performance of three low-global warming potential refrigerants R1224yd(Z), R1223zd(E) and R1336mzz(Z) were studied to replace R245fa in the high-temperature heat pump system. The results showed that the heating capacity of R1224yd(Z), R1223zd(E) and R1336mzz(Z) was 6, 12 and 88% less than that of R245fa, respectively. The coefficient of performance (COP) of R1224yd(Z) and R1223zd(E) was 2 and 1% higher than that of R245fa, respectively. However, the COP of R1336mzz(Z) was 5% less than that of R245fa. The difference in compressor discharge temperature between R1224yd(Z), R1223zd (E), R1336mzz(Z) and R245fa was about ±5°C. R1224yd(Z) is the best refrigerant to replace R245fa. R1223zd(E) is the second. R1336mzz(Z) cannot be directly replaced unless the original system is modified.