A novel thermal management system with a heat-peak regulator for fuel cell vehicles

Abstract

Thermal management of fuel cell vehicles is posing a constant challenge due to the growing installed power of the fuel cell stack and consequent heat-overloaded situations of the radiator. Based on the “time-dependent” idea that considers the fluctuated heat generation and the intermittent heat peak during the journey, a novel thermal management system that employs a heat-peak regulator is proposed in the present work. The heat-peak regulator is a thermal accumulator filled with phase-change material that separately exchanges heat with the fuel cell coolant and the air conditioner refrigerant. It temporarily receives the excess heat that cannot be released out by the radiator when the heat peak occurs; later on, when the heat peak is gone, the heat is transferred to the refrigerant to remove it from the condenser. The system simulations based on the developed thermal models demonstrate that, the thermal runaway of the fuel cell stack can be eliminated or effectively weakened by this novel thermal management system, relying on the amount of the phase-change material filling the heat-peak regulator. In the present study, the 135 s and 250 s thermal runaway durations can be shortened to 0 s and 105 s, respectively, in the standardized New European Driving Cycle and World-wide Harmonized Light Duty Test Cycle under 38 °C summer weather, and the maximum temperature for the latter can be reduced from 89 °C to 83 °C. This work can make a significant contribution towards the solution of thermal management problems of the fuel cell vehicles.