Research on the Thermal Balance Test Method of Fuel Cell Electric Vehicles

Fuel cell electric vehicles (FCEVs) are gaining increasing interest due to contributions to zero emissions and carbon neutrality. Thermal management of FCEVs is essential for fuel cell lifespan and vehicle driving performance, but there is a lack of specialized thermal balance test standards for FCEVs. Considering differences in heat generating mechanism between FCEVs and internal combustion engine vehicles (ICEVs), current thermal balance method for ICEVs should be amended to suit for FCHVs. This study discussed thermal balance performance of ICEV and FCHVs under various regulated test conditions based on thermal balance tests in wind tunnel of two FCEVs and an ICEV. FCEVs reported overheat risk during low-speed climbing test due to continuous large power output from fuel cell (FC). Frequent power source switches between FC and battery were observed under dual constrains of fuel cell temperature and battery state of charge (SOC). Significant temperature exceedance of ICEV occurred during flameout and soaking test due to heat accumulation after flameout. Duration time to reach thermal balance state for FCEVs was longer than ICEV due to deterioration in thermal exchange efficiency resulted from inconspicuous temperature difference between FC and coolant. Several modifications including extended test duration time and integration of test conditions were proposed to develop thermal balance test condition sequence for FCEVs. Graded verification system was recommended to comprehensively judge thermal management performance of FCEVs. Such proposal was expected to support the formulation of FCEVs thermal balance test standard and guide improvements of vehicle thermal management performance.