Theoretical and experimental investigation of a heat pump system using new generation refrigerant fluids with low GWP ratio

In this study, a small capacity water-to-water heat pump system was designed and manufactured. The heat pump system has been designed for R134a refrigerant. R134a and as low GWP ratio new generation refrigerants R134a / R1234yf (75/25), R513A, R134a / R1234yf (25/75) and R1234yf have experimentally investigated in the heat pump system. Refrigerants were tested in the heat pump system for three different evaporator temperatures (-10 oC, -5 oC, 0 oC) and constant condenser temperature (35 oC). In the study, using experimental data, energy, exergy and environmental impact analyzes were made and compared for each refrigerant. Life cycle climate performance (LCCP), environmental analysis and enviroeconomic analysis methods were used for the environmental impact analysis. It has been observed that the heat pump (COPHP) and the total system (COPsystem) of energy performance coefficient increase as the evaporator temperature increases. It was observed that the heat pump energy performance coefficient and the energy performance coefficient of the whole system was the highest refrigerant R134a/R1234yf (75/25) at -10 oC, -5 oC and 0 oC evaporator temperatures. The most exergy destruction occurred in the compressor for all refrigerants at -10 oC, -5 oC and 0 oC evaporator temperatures and then the most exergy destruction occurred in the evaporator. The least exergy destruction for all refrigerants occurred at the expansion valve and condenser. Although the heat pump test system is designed for R134a, the exergy efficiencies of R134a / R1234yf (75/25), R513A, R134a / R1234yf (25/75) and R1234yf refrigerants have generally been found to be higher or almost similar to R134a. Therefore, according to the second law of thermodynamics, it has been concluded that R134a / R1234yf (75/25), R513A, R134a / R1234yf (25/75) and R1234yf refrigerants can be used in systems operating with R134a without any changes. As a result, R134a / R1234yf (75/25), R513A, R134a / R1234yf (25/75) and R1234yf refrigerants can be used as alternative refrigerants in systems operating with R134a according to the results of energy, exergy and environmental impact analysis.