Degradation and performance recovery of 150 kW dual-stack proton exchange membrane fuel cell system for heavy-duty truck applications

The durability tests for a proton exchange membrane fuel cell (PEMFC) system comprised with dual stacks connected in series for an external power supply are rarely performed. A PEMFC system (150 kW) with dual stacks was researched under automotive proton exchange membrane fuel cell decay-accelerated test condition (DAC) with the aim of analyzing the mechanism of the effect of vertical arrangement on the stacks’ durability and proposing mitigation options. In addition, the ability of the hydrogen-air dual-chamber purge method to recover the system performance was also researched. The DAC test with 2000 h shows that the PEMFC stack located at the top of the system (called upper stack) has a higher output voltage and better single-cell voltage uniformity than the one located at the lower portion of the system (called lower stack), which is due to the non-uniform distribution of condensate in the hydrogen distribution manifolds between the substacks. Increasing the anode inlet temperature to 70 °C by a plate heat exchanger improves the voltage uniformity of the lower stack by 14.1 % and the minimum CVM voltage by 20 mV, narrowing the performance difference between stacks in the PEMFC system. In addition, the experimental results show that after performance degradation, the hydrogen-air dual chamber purge can improve the rated output voltage of the system as well as the voltage uniformity of the lower stack.