Dynamic Performance Assessment of a PEMFC-Assisted Ground Source Heat Pump System with Cascade Waste Heat Recovery in Severe Cold Regions

Ground source heat pump systems are prone to long-term ground thermal imbalance in severe cold regions because seasonal heat extraction considerably exceeds summer heat rejection. To address this issue, this study proposes a proton exchange membrane fuel cell-assisted ground source heat pump system with cascade waste heat recovery for a heating-dominated industrial building in Changchun, Northeast China. A TRNSYS-based dynamic simulation model was developed by coupling the building load, PEMFC stack, vertical ground heat exchanger, water-source heat pump, thermal storage tank, battery storage, circulation pumps, and coordinated control modules. The recovered PEMFC waste heat was preferentially used for space heating and thermal storage and was further allocated for ground-side thermal compensation when required. Annual and ten-year simulations were conducted to evaluate the effects of PEMFC integration on ground-side temperature, soil thermal balance, heat pump power consumption, and seasonal coefficient of performance. The simulated annual heating and cooling demands were 516,721 and 99,538 kWh, respectively, confirming the strongly heating-dominated load profile of the case building. Compared with the reference GSHP system, the PEMFC-assisted system reduced the annual soil temperature drop from 1.24 °C to 0.37 °C. Over ten years, the final average soil temperature increased from 7.29 °C to 9.95 °C, corresponding to a 52.1% reduction in cumulative soil temperature decline. In addition, the winter heat pump power range decreased from 15.76–39.94 kW to 12.33–28.90 kW, while the average heating-season COP increased from 4.68 to 5.21. These results demonstrate that PEMFC waste heat recovery can serve not only as an auxiliary heating source but also as an active ground thermal compensation mechanism, thereby improving the long-term thermal sustainability and operational performance of GSHP systems in severe cold regions.