Thermodynamic modelling of a water-to-water heat pump using propane as refrigerant

The aim of this paper is to develop a thermodynamic model for a water-to-water heat pump using propane as refrigerant. This model is based on the thermodynamic principals and heat transfer fundamental laws. The performances of the heat pump have been looked at as function of the water temperatures at the entry of the evaporator and the condenser. The results show that the cooling and heating COP of the system increase slightly when increasing the evaporator water inlet temperature and decrease when increasing the condenser inlet water temperature. However, in cooling mode, the exergy efficiency decreases when increasing the inlet water temperatures to evaporator and condenser, while, in heating mode, it increases. Furthermore, it is shown that the exergy efficiency in the cooling mode does not produce the same behaviour as that of the COP.