Optimal performance and modeling study of air-cooled proton exchange membrane fuel cell with various bipolar plate structure

The multi-physical field distribution inside an air-cooled proton exchange membrane fuel cell exhibits a very complex coupling relationship. Change of the stack structure directly affects the balance of multi-physical fields inside the cell. In this paper, we compare the effects of different stack structures and fan operating conditions on the multi-physical field distribution patterns of water, heat, mass and electricity inside the cell by building three-dimensional numerical models of rectangular and toroidal electric stacks. The results show that the overall uniformity of the distribution of each physical field inside the toroidal stack is better than that of the rectangular stack. Also, water inside the toroidal stack is more likely to accumulate at locations near the cathode outlet. When the fan-to-air ratio is increased from 5% to 40%, the local aggregation of water gradually disappears, and the rest of the physical fields and the cell output are further improved. The results of this study are useful for the design of air-cooled stack structures and related operation strategies.