Numerical Investigation of Flow Channel Design and Tapered Slope Effects on PEM Fuel Cell Performance

Abstract

High-power proton exchange membrane (PEM) fuel cell vehicles are important for the realization of carbon neutrality in transportation. However, it is difficult to maintain enough fuel supply and quick water removal capacity at a high current density where reactant gas transportation and water concentration are directly affected by flow channel configurations. This study aims to investigate the tapered slope effects of a flow channel on fuel cell performance using a 3-D CFD model. The positive, negative, zero and hybrid tapered slopes are proposed to illustrate the fuel cell voltage, reactant gas and water vapor concentration in the flow channels. Among them, the flow channel with a positive tapered slope performs better, especially at a high current density. Then, the positive tapered slope effects are discussed, including different tapered slopes, inlet depths and widths of flow channels. The results show that the larger the tapered slope, the smaller the depth and width, and the better the fuel cell performs; the corresponding current densities are increased by a maximum of 6.53%, 12.72% and 61.13%. The outcomes stated above provide a key direction for flow channel design that can particularly achieve higher fuel cell power density at high current densities.

Key findings

• ▸A positive tapered slope performs better than other configurations, especially at high current densities.
• ▸Larger tapered slopes result in smaller flow channel depths and widths, leading to improved fuel cell performance.
• ▸The maximum current density increases by 6.53%, 12.72%, and 61.13% with larger tapered slopes.

Keywords

Identifiers

DOI

10.3390/su141811167

Journal

Sustainability

Year

2022