Multi-objective optimization of a hybrid PVT assisted ground source and air source heat pump system for large space buildings using transient metamodel

The ground source heat pump (GSHP) system is widely employed as a clean, efficient and economical renewable energy technology for HVAC and hot water supply. In cold zone of China, however, the building heating load is much larger than that of cooling load, which may cause significant soil temperature drop and GSHP performance deterioration. To solve this problem, a novel PVT assisted GSHP and ASHP system (PVT-GA) for gymnasium was proposed in this research. Using transient FEDformer as metamodel, NSGAII was employed for multi-objective optimization of grid power consumption, CO 2 emission, and LCC. Six systems with different configuration were compared. Results show that the optimal PVT-GA system has best performance. Compared with the original system, it reduces the grid power requirement by 70.80%, CO 2 emission by 70.53%, and LCC by 54.57%. The system also could improve the PV array power generated efficiency by 14.81%. Furthermore, the average soil temperature of PVT-GA system could stable at 15.88 °C, and the COP of GSHP and whole system also could keep stable at a high level with 5.365 kW/kW and 6.296 kW/kW. This research offers a solution to soil thermal imbalance problem in GSHP system and efficiency attenuation issue of PV caused by overheating. • A novel PVT assisted GSHP and ASHP (PVT-GA) system for gymnasium was proposed. • The LTSF FEDformer metamodel and NSGAII optimization model were employed for system optimization. • The method could balance soil temperature of GSHP, improve photovoltaic efficiency, and system COP. • Energy consumption, LCC and CO 2 emission were significantly reduced by PVT-GA system.