Analysis of a 50 kWe indirect methanol proton exchange membrane fuel cell (PEMFC) system for transportation application

Abstract

Steady state and dynamic models of proton exchange membrane fuel cell (PEMFC) or solid polymer fuel cell (SPFC) systems have been developed for transport and stationary applications. This paper reports the results of a steady state analysis of a methanol-fuelled PEMFC vehicle with a maximum (electrical) power output of 50 kW. The model incorporates a methanol steam reformer, gas clean-up unit, fuel cell stack, compressor, expander, battery pack, and heat exchangers as well as electrical power handling, motor, gearbox, and final drive. Results are given for the reformer as a function of steam-carbon ratio and reformer temperature. A degree of optimization of the system was conducted by (a) the addition of preheat to the reformer and burner reactants and (b) the addition of condensers for the fuel cell exhaust gases. The effect of operating pressure was also investigated. It was concluded that only by proper thermal integration could the target electrical system efficiency of better than 45 per cent at rated power be achieved.