基于MEMS技术的微型DMFC阳极流场结构的设计与研究

Design and Investigation on Anodic Flow Field Structure of Micro Direct Methanol Fuel Cell Based on MEMS Technology

流场结构对微型直接甲醇燃料电池(μDMFC)的性能有着重要的影响,尤其表现在影响燃料供应和温度分布上。本文运用计算流体动力学(CFD)的方法,分析和比较了双蛇形和平行流场结构中流速、温度等分布情况。模拟结果表明双蛇形流场结构比平行流场结构显示出更优的流速分布和更均匀的温度分布。采用微机电系统(MEMS)技术,在N型单晶硅片上制作出流场结构,并组装成电池进行测试。实验结果表明:当温度为25℃,进口流速为0.01 m s-1时,由双蛇形流场结构制作的单电池功率密度达到了34.2 mWcm-2。

Flow field structure is very important for the performance of the micro direct methanol fuel cell （μDMFC）, which may determine the distribution of fluid flow and temperature. In this study, flow velocity and temperature distributions of double serpentine and parallel flow fields were simulated by a computational fluid dynamical （CFD） method. Simulated results indicate that the double serpentine flow field structure shows better flow velocity distribution and more uniform temperature distribution. Further experimental investigation also was carried out by fabricating flow field structure on N - type silicon wafers based on MEMS technology. At a temperature of 25 %, the maximum power density of the DMFC with double serpentine flow field structure reached 34.2mWcm - 2 when the inlet flow velocity is 0.01 m s^-1.