Purge Strategy for PEM Fuel Cells Considering Economy and Durability

In this paper, a dynamic model is developed based on the phase change of water to predict the accumulation of impurities under different operating conditions. Based on the goal of improving the durability of the stack, a liquid water accumulation index is proposed. The stack purge interval is selected based on the liquid water accumulation index. In addition, the cost of purging hydrogen was introduced to calculate the energy utilization of the purging process. The simulation results show that the proposed model with rate of nitrogen below a certain threshold is considerably more effective in stopping the purge duration as compared to the voltage dropping purge stopping strategy, effectively improving the economy of purging.