Volume design of the heat storage tank of solar assisted water-source heat pump space heating system

The paper presents a method to design the volume of the heat storage tank of the solar assisted water-source heat pump space heating (SAWHPSH) system. With the area of the solar thermal collector calculated according to the China national design code for solar heating system, the space heating load and the solar radiation are considered simultaneously in this method. The design method of the volume of the solar heat storage tank is elaborated afterwards. In order to show the advantage of this design method, TRNSYS software was used to simulate the same SAWHPSH case project with the volume of the heat storage tank designed by both the method brought out in the paper and the one described in the China national design code. Performances of the system designed by the two different methods are investigated and the results show that the SAWHPSH system with the heat storage tank volume designed by the method presented in the paper has a higher average system COP.