Exergy analysis of a fuel cell power system for transportation applications

An exergy analysis of a solid polymer fuel cell power system for transportation applications is reported. The analysis was completed by implementing the fundamental governing second law equations derived for the system into a fuel cell performance model developed previously. The model analyzes all components of the system including the fuel cell stack and the air compression, hydrogen supply, and cooling subsystems. From the analysis, it was determined that the largest destruction of exergy within the system occurs inside the fuel cell stack. Other important sources of exergy destruction include irreversibilities within the hydrogen ejector and the air compressor, and the exergy associated with the heat rejected from the radiator. The results may aid efforts to optimize fuel cell systems.