Exploring the performance of the thermal management system in a FCV based on real vehicle testing under different driving conditions

Effective thermal management is essential for improving energy conversion efficiency in fuel cell vehicles (FCVs). This study conducted real-vehicle tests under various speeds (30–110 km/h) and ambient temperatures (25 °C and 40 °C) to evaluate the heat load characteristics and thermal management performance of a commercial FCV. A comprehensive analysis was carried out on heat load distribution, coolant flow rate, heat exchanger effectiveness, and thermal coupling among different cooling loops, aiming to identify opportunities for system efficiency improvement. The results show: (1) The total heat load of FCV peaked at 50.71 kW, with the fuel cell stack contributing up to 82.39 %, suggesting its cooling demand should be prioritized. (2) In the high-temperature loop, radiator effectiveness (22.2 %–98.48 %) and fuel cell efficiency (46.5 %–54.0 %) both declined with increasing speed and ambient temperature, potentially increasing energy demand. (3) In the low-temperature loop, the motor branch received only 57.81 % of coolant flow despite carrying 69.45 % of the heat load, indicating flow-load mismatch, which may increase energy consumption. (4) The cooling demand and performance of the refrigeration loop are minimally affected by vehicle speed, suggesting the potential for simplified control strategies. (5) Thermal coupling was observed between heat exchangers of different cooling loops, resulting in a maximum increase of 10.7 °C in the inlet air temperature of the high-temperature radiator, which weakened its heat rejection capability and reduced system efficiency. This study analyzed the heat load characteristics and cooling performance of an FCV, and proposed improvement measures based on experimental results to support energy management optimization.