Verified PEMFC heavy-duty long-haul truck vehicle model with thermal management limitations of conventional cooling systems

Artikel i vetenskaplig tidskrift, 2025

In the challenge to decarbonize heavy-duty long-haul vehicles, low-temperature proton exchange membrane fuel cell propulsion offers advantages like high efficiencies, power densities and fast refueling although challenges regarding lifetime, cost and thermal management remain. Therefore, a generic 44 t truck vehicle model with conventional cooling system has been developed in Siemens Simcenter Amesim and verified against input data from Volvo Trucks to identify its thermal limitations. Accurate identification of heat rejection limitations of conventional cooling systems enables the development of improved cooling solutions for existing vehicle platforms. The resulting model runs on average 5.8 times faster than real time and reveals severe vehicle performance losses already at 20 °C ambient temperature. A fuel cell net power derating of 46 % is required to prevent overheating at reduced velocities in a hill climb driving scenario at beginning of life conditions since the radiator can only provide about 40 % of the full load heat rejection. The model endeavors to be a representative HD truck simulation and includes details that can affect vehicle operation like braking resistors to substitute engine braking, fuel cell power-ramp rates, altitude as well as power derating of the fuel cells, traction battery and electric machines. The modular vehicle model presented here can be used as a platform for investigations of enhanced fuel cell models, degradation, improved thermal management solutions or design and control strategy studies. We present a detailed heavy-duty fuel cell truck vehicle modelling approach, its verification and results from the VECTO Long-haul and two hill climb driving cycles.