Abstract:

The effect of the flow field structure on the transport and transfer of water electrolysis reaction substances within a proton exchange membrane electrolysis cell (PEMEC) was investigated. Through the simulation software COMSOL modelling, the ratio of the PEMEC flow channel width to the flow channel ridge width (γ) and the number of flow channels (λ) were varied to study the effects of the changes of γ and λ on the performance of the PEMEC with the flow channel width fixed at 1 mm. The results show that the electrolyte current density is highest at γ = 1, which is 6.9% higher than that of the cell with γ = 2 and 13.8% higher than that of γ = 3. When λ is increased, the PEMEC performance changes considerably. When γ = 1 is fixed and λ is changed, it is found that the increase in the number of flow channels increases the PEMEC flow channel pressure drop, which is beneficial to the uniform distribution of current density and oxygen, thus promoting the PEMEC performance improvement and current density increase. However, an increase in the number of flow channels also leads to an increase in flow resistance, which affects oxygen discharge.

Key words: proton exchange membrane electrolysis cell (PEMEC), software COMSOL simulation, ridge width ratio, current density, pressure drop