Effect of Flow Channel Blockage on the Scale-Up of Proton Exchange Membrane Fuel Cells

Optimizing flow field structure can effectively improve the performance of Proton Exchange Membrane Fuel Cell (PEMFC). Adding the block in the flow channel is one of the approaches. In this work, the enhanced transport characteristic of the block is re-examined, and its effect on the performance of the fuel cell scale-up is further revealed. The models of single-channel fuel cells with different lengths L and blockage ratio beta are developed. Results show that the best cell performance exhibits when beta = 100% due to the combined effect of the block and upstream zone. The convection appears below the block, and higher upstream pressure is induced, both of which increase the oxygen concentration at the catalyst layer. Besides, results indicate that the performance of the scaled-up fuel cell with blockage increases at a slower rate. Combined with the pump power, it is found that the addition of the block with beta = 100% is indeed beneficial for the fuel cell scale-up. The findings of different blockage effects on different-sized cells provide guidelines for the flow field design.