Comprehensive performance of pv/t-gchps under heating conditions

Abstract

In HSCW (Hot Summer and Cold Winter) climate zone of China, the building heat load is usually less than the cooling load which caused the problem of thermal accumulation of underground soil to damaged the COP of the heat pump system. PV/T-GCHPs (Photovoltaic/photothermal - Ground-coupled heat pump system) is a system that realizes the complementary utilization of geothermal energy and solar energy to solve the problem. The experimental platform of the system was designed and built, and the effect of the temperature of the outlet water from the ground buried pipes on the photoelectric efficiency of the PV panel was analyzed through experiments and simulations under the heating conditions of the PV/T-GCHPs system, and the heating performance coefficients of PV/T-GCHPs and GCHPs were compared. The results show that the PV plate temperature reaches the lowest when the heat pump load is 75% and the circulating water flow is 0.28 kg/s, when the outlet temperature of buried pipe is 8℃. The maximum photoelectric efficiency increased by 6.4% under above conditions, the average heating performance coefficient of PV/T-GCHPs is increased by 2.2% compared with GCHPs. The daily average comprehensive efficiency is 63.32%, the maximum comprehensive efficiency of the system is 74.67%. The maximum heat collection efficiency of PV/T collector is 48.33%. This paper hopes to provide a theoretical basis for the promotion of PV/T-GCHPs in HSCW climate zone of China.

Keywords

• PV/T-GCHPs
• Solar energy
• Geothermal energy
• Heat conduction
• Photoelectric efficiency
• Heating performance coefficient