Trade-off working fluid selection for heat pumps

Abstract

Nowadays heat pump systems are used to recover the heat from waste water from different sources and produce hot water for household and communal purposes. In this research comparative thermodynamic analysis of performance for a water-to-water single-stage vapor compression heat pump using several HCs, HCFCs and HFCs which belong to refrigerants of different generations is presented. A multi-criteria approach for optimal selection of refrigerants was used as scientific tool. Results of theoretical experiments of vapor compression heat pump system with the evaporator temperature range 0…25°C and condenser temperature 60°C and 83°C showed that the COP of R1234ze was higher than that of R600a, R152b by about 6.7…17.3%, 8.25…20.5%, and 1.7…14.4%, respectively, at condenser temperature 60 °C; however results are different if at condenser temperature is 83°C: the average COP of R600a was higher than that of R1234ze and R152b by about 7.7…14.7%, 9.3…15.8%, and 7.5…15.6%, respectively. COP displays a positive correlation with the evaporator temperature as well as a negative correlation with the condenser temperature. The complete analysis of all factors, including environmental safety, indicates that R1234ze and R600a refrigerants should be preferred as the working fluids for using in the water-to-water single-stage vapor compression heat pump for the hot water supply and heating purposes in industrial applications.