Improving Water Management and Performance of an Air-Cooled Fuel Cell System Using Pressurized Air for Aviation Applications

Abstract

Air-cooled fuel cell systems feature a light-weight and simple design and are thus recognized as a suitable technology for drone and aviation applications. As compared to liquid-cooled fuel cell systems, however, they suffer from low specific power per unit volume and unstable performance due to severe electrolyte dehydration and nonuniform profiles of current density and temperature inside a fuel cell stack. Here, we present a high-pressure air-cooled fuel cell system in which atmospheric air is pre-compressed by a compressor and then fed into the fuel cell stack. To minimize the compressor power consumption, the system is designed to recirculate the exhaust air from the fuel cell stack. A three-dimensional two-phase fuel cell model is implemented with a high-pressure air-cooled fuel cell system mainly consisting of an air-cooled fuel cell stack, compressor, air chamber and duct, and heat exchanger and is used to predict superior fuel cell performances under various high-pressure conditions. Simulation results show that the fuel cell operation at 2 atm allows an increase of up to two times the stack power and 1.5 times the net system power compared to a 1-atm fuel cell operation.