Advanced air supply system topologies for fuel cells in aircraft applications

Abstract

Proton exchange membrane fuel cells hold great promise as a power source for future low-emission aircraft. However, the reduced ambient pressure at high altitudes poses challenges for the reactant air supply to the fuel cells. We introduce several advanced topologies for the fuel cell’s air supply and analyze them with a thermodynamic model, which uniquely accounts for interactions with the stack, humidifier, and thermal management system. The results show that the optimal topology depends on the aircraft type. For the propulsion of regional aircraft, an added turbine stage can reduce the mass of the fuel cell system and tank by 4.5 %; whereas for auxiliary power in larger aircraft, two-stage compression enables a 10.9 % efficiency gain during cruise. These findings underscore the importance of tailored air supply solutions for fuel cell systems and provide a pathway towards improving their performance in aircraft applications.