Abstract：

Deduces a mathematical model reflecting the relationship between the coefficient of performance(COP) of watersource heat pump units and the water temperatures on evaporator side and condenser side through analysing the influence of the water temperatures of the two sides on the COP under constant temperature difference and variant working conditions. This model is verified by the confirmation of the production data provided by a manufacturer and comparison with other models.

Keywords:watersource heat pump, variant working condition, COP, mathematical model, evaporator side, condenser side, water temperature