Coupling performance of solar-ground source heat pump systems in severe cold zone

In order to solve the problem of soil heat imbalance caused by ground source heat pump system heating in severe cold zone, taking the solar-assisted ground source heat pump coupling system as the research object, analyses the energy supply performance of ground heat exchangers, the soil temperature variation characteristics after the system operating for one year and ten years respectively, and the relationship between the initial soil temperature and the collector area. Obtains the mathematical expression of the initial soil temperature and the optimal collector area per unit building area by fitting. Uses the annual cost method to compare the economy between the coupling system and the conventional coal-fired boiler heating system. The results show that when the coupling system is used for heating in winter and the temperature difference between the outlet of the hot water storage tank and the buried pipe is 10 ℃ to control the solar heating system for auxiliary heating, the average soil temperature increases by 0.09 ℃ and the soil heat balance rate is 101% after one year operation, and the average soil temperature increases by 0.35 ℃ and the soil heat balance rate is 104% after ten-year operation. The heating economy of the coupling system is better than that of the conventional coal-fired boiler heating system.