Simulation and experimental study on the performance of a solar-powered PVT electric-thermal hybrid air-water-soil three-source heat pump system

To address the performance degradation of a standalone ASHP, this study developed a multi-source coupled system integrating photovoltaic-thermal (PVT), ASHP, water source heat pump (WSHP), and ground source heat pump (GSHP). Using Aspen Plus, the perturbation characteristics of parameters such as refrigerant flow rate and heat source/load temperatures on system performance were quantitatively analyzed. Sensitivity analysis indicates that the ASHP system is highly sensitive to ambient temperature fluctuation. At 0 °C, the pressure ratio rapidly climbs to approximately 9.0, while the coefficient of performance (COP) remains low; by contrast, water-source heat pumps based on PVT technology achieve good instantaneous efficiency as the evaporation temperature rises to 15–35 °C thanks to solar assistance. The GSHP leverages the stability of ground temperature to ensure reliable all-weather operation. By incorporating flow resistance and an ambient heat loss coefficient of 18%, the simulation error in the COP was reduced to 3.2%, thereby validating the accuracy of the model. The environmental assessment confirmed that all three heat pump types offer significant potential for reducing emissions. Under same operating conditions, WSHP mode achieves 20–30% greater CO 2 emission reductions than ASHP, thanks to the auxiliary role played by the PVT system. This research demonstrates a pathway for low-carbon heating in severe cold regions, that is utilizing the PVT-WSHP to enhance efficiency during the day and relying on the GSHP to guarantee operation stability at night.