Advanced Radiator Design with Water Spray Injection to Enhance the Cooling Performance in FCEV

The thermal management system in fuel cell electric vehicles (FCEV) is characterized by a particularly high complexity. In addition to the optimization of the vehicle’s energy efficiency, the realization of high cooling performances for the fuel cell during demanding operating conditions is a main challenge. This paper investigates an advanced fuel cell cooling concept with water injection assisted radiator design, by analyzing its performance capabilities and energy requirements within the framework of an FCEV complete vehicle co-simulation. To provide a benchmark, the complete vehicle co-simulation is initially developed for a state-of-the-art fuel cell electric passenger car. By extending thermo-hydraulic fluid circuits in the thermal management software KULI with mathematical-physical models in MATLAB/Simulink as well as by using advanced modelling methodologies for the fuel cell, powertrain and vehicle cabin, the effects of a wide range of operating conditions on the FCEV characteristics are investigated with a high level of detail. The analyzed advanced cooling concept integrates water spray injection upstream of the stack coolant radiator to use the evaporative cooling effect. For analysis, this design is likewise modelled extensively and integrated into the benchmark overall vehicle simulation. Results from the comparison with the benchmark setup prove the suitability of water injection assisted radiator design to extend the allowable operating range of an FCEV, especially up to high ambient temperatures and demanding driving scenarios. These insights provide the basis for ongoing research and testing.