Abstract：

The annual energy consumption characteristics of a typical ultra-low energy single residential building are analysed.Based on the TRNSYS platform,a solar PVT supplementary underground pipe ground-source heat pump system suitable for the building is established,and its annual operating characteristics and system production capacity are simulated and analysed.The simulation results show that the average heating power of the system during the heating season is 16.8 kW,and the average heating COP is 5.1.The average cooling power of the system during the cooling season is 15.3 kW,and the average cooling COP is 5.9.Under spring and autumn conditions,the average supplementary heat power of the PVT system is 16.0 kW and 15.7 kW,respectively,increasing the soil temperature by 2.0 ℃ and 1.0 ℃,respectively.After ten years of operation,the soil temperature only decreases by 0.6 ℃,which is 86.0% lower than that of the conventional ground-source heat pump systems.Therefore,this system has significant advantages in maintaining soil temperature balance.The annual power generation of the PVT system is 11.1 MWh,the net power consumption of the building is 12.3 MWh,and the comprehensive energy consumption index (standard coal) of the building is 3.98 kg/(m2·a),which is much lower than the design index of ultra-low energy buildings.

Keywords:solar photovoltaic and photothermal integration; PVT supplementary underground pipe ground-source heat pump; combined cooling,heating and power; ultra-low energy residential building; renewable energy; soil temperature