PEM fuel cell heat recovery for preheating inlet air in standalone solar-hydrogen systems for telecommunication applications: An exergy analysis

In this paper, a theoretical model of a PEMFC with heat recovery system (PEMFC-HR) for preheating its inlet air to mitigate the performance degradation, when the fuel cell operates in an extreme cold environment, is proposed and evaluated by using exergy analysis. In this modeling study, HOMER and TRNSYS software tools are used to simulate the yearly load profile of a PEMFC in the context of a standalone hybrid solar-hydrogen system (hybridized with batteries) for telecommunication application in cold climate conditions. A dynamic theoretical model of the PEMFC-HR is then built in MATLAB environment to simulate and investigate the impacts of input parameters on the performance of such system. Furthermore, by using a high effectiveness heat exchanger (HE), the inlet air temperature of the PEMFC can be increased from sub-zero to well above the freezing point temperature. The impacts of the various ambient temperatures and fuel cell power on the exergetic efficiency of PEMFC-HR are then theoretically investigated and compared with the PEMFC coupled with an external electric heater (PEMFC-EH). Based on a case study for Eureka, Canada, the modeling results showed that approximately equivalent to 30% of the electrical energy, generated annually by the PEMFC, can be saved by replacing the PEMFC-EH arrangement with a PEMFC-HR system.