Performance Prediction and Analysis of Solar-Assisted Ground-Source Heat Pump Systems in Typical Rural Areas, China

The increasingly severe energy crisis and associated environmental issues pose new challenges for the efficient and rational utilization of renewable energy. The solar-assisted ground-source heat pump (SAGSHP) system is a novel heating system that effectively combines the advantages of both solar and geothermal energy. In this study, an SAGSHP system was established through TRNSYS simulation software to provide winter heating and year-round domestic hot water for a residential building. By varying the area of solar collectors (A) and the number (n) and the depth (H) of the borehole heat exchangers (BHEs), the system operational performance, including the system energy consumption, ground temperature attenuation, and heat pump efficiency, was investigated. A comparison with a single ground-source heat pump (GSHP) system was also conducted. After 20 years of operation, the parameter optimization resulted in a reduction of approximately 60 MWh and 70 MWh in system energy consumption, equivalent to saving 7.37 t and 8.60 t of standard coal, respectively. At the same time, the total costs over 20 years can be reduced by 48.20% and 33.77%, respectively. The proposed design method and simulation results can serve as the reference for designing and analyzing the performance of the SAGSHP system.