Experimental and simulation study on R134a/RE170/R152a mixture as R134a replacement in a moderately-high temperature heat pump

A novel ternary mixed refrigerant was proposed in this study, and its optimal ratio was determined. The newly proposed refrigerant was termed RDR-a. Experiments were performed to compare the system performance of RDR-a and R134a for applications in the moderately high-temperature heat pump (MHTHP) system. As indicated by the results of this study, RDR-a achieved a lower cost, and it exhibited the capability of applying to the system of R134a directly. Besides, RDR-a achieved a GWP of 61.79% lower than R134a. Moreover, the coefficient of performance (COP) of RDR-a and R134a was elevated by 0.071/celcius and 0.037/celcius, respectively, with the inlet temperature of chilled water. Moreover, the COP of RDR-a and R134a declined by 0.09/celcius and 0.037/celcius, respectively, with the outlet temperature of cooling water. The COP of RDR-a and R134a tended to be first increased and then decreased with the rise of the charge amount, and RDR-a achieved an optimal charge amount that only accounted for 80.95% of that of R134a. Furthermore, RDR-a achieved a COP of 4.94%, 10.01% and 20.52% higher than that of R134a, respectively, as the inlet temperature of chilled water, the outlet temperature of cooling water and the charge amount of the refrigerant varied. The heating capacity of RDR-a was examined to be 13.61%, 19.14%, and 29.47% higher than that of R134a, respectively.