PERFORMANCE EVALUATION OF A LARGE CAPACITY WATER-WATER HEAT PUMP USING PROPANE AS REFRIGERANT

The use of natural refrigerants has become of increasing concern in recent years due to the high GWP and ODP of commonly used CFCs, HCFCs and HFCs. The use of hydrocarbons can be considered as potential long term solution in heat pump applications. Propane is highly flammable and potentially explosive, however; with proper safety measures in place it can be a suitable candidate for residential heat pump as it has a negligible ODP and a low GWP (3). This study presents the analysis of experimental data obtained from tests on a 45 kW heating capacity water-water heat pump. The unit is tested in heating mode, i.e. production of hot water for space heating with the possibility of simultaneous-generation of domestic hot water. The performance evaluation is carried out at system level, based on the two key parameters: heating capacity ((Q) over dit(h)) and the heating COP (COP1). A map of the heat pump performance under different working conditions is developed. Simulations using the modelling software IMST-ART are performed and compared to the experimental results. The results of this study were developed in the framework of the FP7 European project 'Next Generation of Heat Pumps working with Natural fluids' (NxtHPG).