Enhanced performance and a multi-criteria evaluation of a proton exchange membrane fuel cell with natural water-drop flow channels

A water-drop flow channel is proposed and focuses on improving oxygen transfer characteristics and reducing flow channel pressure drop in PEMFC. In this study, a three-dimensional multi-physics model is established to study effects of the water-drop flow channel. Four types of water-drop flow channel are designed by changing the water-drop unit spacing. Results show that applying the newly-designed flow channel to the cathode side alone is sufficient to enhance the fuel cell performance. The oxygen content in the diffusion zone of fuel cell with water-drop flow channels is increased, and the liquid water content on the cathode side is reduced. Type 1 flow channel achieves the highest peak power density by increasing 15.49% compared with the flat-flow channel, and the pressure drop is reduced by 37.69%. Type 1 shape of the water-drop streamline is further geometrically simplified. Finally, based on the entropy weight TOPSIS method, a multi-criteria evaluation is performed on all flow channel types. Results show that the simplified flow channel is closest to the ideal solution. Besides, the structural simplification is reasonable and the water-drop flow channel is feasible in manufacturing. This study provides an insight for enhancing the mass transfer, facilitating water removal and reducing the pressure drop of fuel cells by referring to the nature-inspired design.