Sensitivity analysis and optimisation of a vehicular PEMFC power system

Abstract

Proton exchange membrane fuel cell (PEMFC) systems are emerging as a promising technological solution for automotive applications. The present work is devoted to performance’s analysis of a power generation system integrating a PEMFC and its auxiliaries designed for vehicle applications. A thermodynamic model for the system behaviour is discussed and validated. A focus was made on the change of operating temperature and pressure, while highlighting a trade-off between the provided net power the overall efficiency of the system. It is found that, operating the PEMFC under 1.2 atm pressure and a temperature of 368.15 K results in significant auxiliary power consumption, representing 20.6% of the PEMFC overall power. This accordingly yields to a decrease in the system’s overall net power and efficiency. It is also shown that increasing the operating pressure from 1.2 to 4 atm, keeping the temperature at 348.15 K results in a relative decrease of 16.09% in the system’s net power, inducing therefore a slight decay of 48.61–40.78% on the overall efficiency. The NSGA-II algorithm was used to generate the optimal Pareto front, including the trade-off target points. The optimal operating conditions for three optimal cases were selected by means of the TOPSIS method. The configuration favouring the system net power rather than its overall efficiency is believed to be the most appropriate, with a 9.05% improvement in comparison with a selected baseline case. However, the optimisation-based improvement induced a slight decrease of 2.48% on the system overall efficiency.