PEM燃料电池毛细压力流道拓展模型

A Capillary Extended Channel Model of PEM Fuel Cells

多孔电极与流道内的水淹现象是制约质子交换膜(PEM)燃料电池性能提高的关键难题。传统的宏观两相模型普遍存在液态水饱和度预测值偏低的不足,而流道内气液两相雾状流的假设则是低估水淹程度的一个主要原因。本文提出了反映流道壁面浸润差异性的毛细压力流道拓展模型,并对低气速下燃料电池内的传热传质进行了模拟。计算结果表明,该模型克服了原有模型对饱和度预测值偏低的不足,不仅反映了液相水分布的贴壁效应,同时还可以考虑流道壁面差异的影响。

Water flooding in porous electrodes and gas channels is the main issue hampering the performance of Proton Exchange Membrane（PEM） fuel cells.Since most traditional numerical models are based on＂Mist-flow＂assumption,which will greatly underestimate the liquid saturation within the cell,it is of vital importance to develop a model accounting for liquid evolution in gas channels. In light of that,we propose a capillary extended channel model and carry out a series of simulations focusing on heat and mass transport within the cell under low gas velocities.It can be drawn from the results that this model can not only overcome the setback of underestimation in liquid saturation of traditional models,but also can account for the effects of different wettability of channel walls.