Investigation on performance of deep borehole heat exchanger heating system coupled air source heat pump with different allocation ratios

The coupled heating system of deep geothermal heat pumps and air-source heat pumps has received extensive attention due to the complementary advantages of the two clean energy sources. However, in the coupled system, the load proportions borne by the geothermal part and the air-source part need to be reasonably designed. This study is based on buildings that use the geothermal heat pump coupled with an air source heat pump system for heating. The dynamic thermal load of the buildings is simulated using DEST, and five different load allocation ratios from 0.5 to 0.9 (the proportion of load borne by the geothermal heat pump) are given. The long-term operation parameters of the geothermal heat pump system are simulated using OpenGeoSys, and the variation laws of power consumption and total cost during the long-term operation of the coupled system are obtained. In summary, the load allocation ratio of the geothermal part should be above 0.7 to achieve the optimal balance between economy and energy conservation.