Computational simulation and experimental evaluation on anodic flow field structures of micro direct methanol fuel cells

摘要

The flow field structures can have a large influence on both flow velocity and temperature distributions of the direct methanol fuel cells (DMFCs), thus proper flow field constructions are very important for the improvement in DMFC's performance. In this work, anodic flow velocity and temperature distributions based on four different designs, including double serpentine, parallel, helix and single serpentine, were simulated in three-dimensional models. Computational fluid dynamics (CFD) was used to investigate the effects of flow field structures on the DMFC's performance. Simulated results indicate that the double-serpentine flow field shows better flow velocity distribution and more uniform temperature distribution, which might lead to a better performance of the DMFC. Further experimental investigation on four types of flow fields also confirmed that the DMFC with double-serpentine flow field structure exhibits a maximal power density at a variety of inlet velocities, which is in good agreement with the simulated results. The maximum power density of the fabricated DMFC with double-serpentine flow field is ca. 34.2 mW cm~(-2) when the inlet flow velocity was 0.01 m s~(-1) at room temperature.