中间换热器对地表水源热泵机组COP影响的模拟研究

Study on the Impact of Isolation Heat Exchangers on the COP of Surface Water Heat Pump Units by Simulation Method

为了定量评价中间换热器对地表水源热泵机组能效的影响,建立了反映机组负荷率,冷凝器及蒸发器进水温度等影响因素的螺杆式热泵机组变工况模型及中间换热器模型,提出了热泵机组变工况模型与中间换热器模型的耦合求解方法。以某酒店为研究对象进行了模拟。结果表明:制冷工况下,采用中间换热器后的热泵机组COP平均降低1.8%。制热工况下,采用中间换热器后的热泵机组COP平均降低0.84%。在进行间接式地表水源热泵系统设计时,应考虑两种工况下机组COP降低幅度的差异性。

In order to quantitatively evaluate the influence of isolation heat exchangers on the COP of surface water source heat pump units,a transient condition model of screw heat pump units considering the load rate,inlet temperatures of condenser and evaporator and a model of isolation heat exchangers are established,and the coupling solution method of the heat pump unit model and the isolation heat exchanger model is proposed.The simulation was conducted using a hotel as a case.The results show that the COP of the heat pump unit is reduced by 1.8%averagely due to the existence of isolation heat exchangers in cooling mode,and that is reduced by 0.84%averagely due to the isolation heat exchangers in heating mode.The difference of the reduction of COP between the cooling and heating mode should be considered during the design of indirect surface water source heat pump systems.