Mathematical models of different parts of water source heat pump system are established separately. Engineering Equation Solver(EES) is used to simulate the model of the system and investigate effects of initial parameters on system performance. 然后对水源热泵机组的各个部分分别建立了数学模型,并使用EngineeringEquationSolver软件对其进行了模拟,探讨了各参数对于机组性能的影响。