微型直接甲醇燃料电池流场板内多相流动分析

Multiphase flow analysis in the flow field of a micro direct methanol fuel cell

针对微型直接甲醇燃料电池,运用多孔介质理论建立了微型直接甲醇燃料电池流场板内含电化学反应的、毛细力驱动下的微通道内多相流动的传输模型;计算并分析了流场板内微通道尺寸、功率密度等重要参数对毛细力驱动下微通道中多相流动的传输特性的影响,以及流场板内微通道尺寸对电池性能的影响。结果表明:微通道内液相饱和度随通道宽度和高度的增加而增大,随节距和电池功率密度的增加而减小;电池的功率密度随微通道高度和宽度的增加而增大,随节距和长度的增加而减小。

The multiphase flow driven by the capillary pressure in the anode flow field of a micro direct methanol fuel cell （μDMFC） is modeled based on the porous media theory. The electrochemical reaction at the anode is taken into account in this model. Parametric studies of the channel size and the power density are carried out to assess the effects on the transport characteristics of the multiphase flow driven by the capillary pressure in micro channels. In addition, the effects of the channel size on the cell performance are discussed. The results show that the liquid saturation in micro channels increases with the increase of the width and height of the channel, but decreases with the increase of the channel pitch and the power density. The cell performance is improved with the increase of the channel width and height. A larger channel pitch and length lead to a lower power density.