Design of a Novel Multidimensional Forced-Convections Flow Channel with Both Blockages and Under-Rib Channels for PEMFC

Abstract

The bipolar plate flow channels are critical to the operation of proton exchange membrane fuel cells (PEMFC). The appearance of a water flood phenomenon at the cathode flow channel affects mass transport capacity and output performance in the fuel cell. Based on the conventional parallel flow field (CPFF), multidimensional design is carried out to improve the comprehensive performance of the flow field. Auxiliary blockage flow fields (ABFF), auxiliary multiblockages flow fields (AMBFF), and auxiliary multiblockages tilt flow fields (AMBTFF) are proposed to overcome the previous concerns in this study. The mass transport of novel flow fields is studied based on fuel cell and electrolysis modules at CFD software FLUENT. The results indicate that multidimensional forced-convections formed in the cathode channel effectively promote both the entry of reactants and the removal of water, particularly in the under-rib region of AMBTFF. Therefore, the oxygen mass distribution in the cell is more uniform, which has a positive effect on the current density distribution, especially at the downstream. The current density in the AMBTFF is 11.1% more than that in CPFF. Moreover, the more stable operation of AMBTFF is confirmed due to the more uniform temperature distribution and the minimal increase of pressure drop. Proton exchange membrane fuel cells are devices that generate electricity through electrochemical reactions of clean fuels, with high efficiency, strong reliability, and zero pollution. It is widely used in equipment such as automobiles, ships, and portable power sources. Bipolar plates account for a significant proportion of the weight and cost of fuel cells, undertaking tasks such as fluid distribution, cooling, and heat dissipation. The flow field design of bipolar plate directly affects the heat and mass transfer capability and fuel cell output performance. The traditional flow field of proton exchange membrane fuel cells suffers from issues such inadequate mass transfer, internal flooding of the catalytic layer, and excessive temperature while operating at high current density. Novel multidimensional flow fields are proposed by this manuscript, which can improve the performance of proton exchange membrane fuel cells and further optimize material transport and drainage capabilities. The result can provide as new inspiration for proton exchange membrane fuel cell flow field design.