本文采用三维孔隙网络模型从孔隙尺度上对质子交换膜燃料电池气体扩散层中水分蒸发的干燥过程进行了模拟,并考虑了阴极流道的影响。计算结果表明毛细力在气体扩散层的干燥过程中起主要作用,气相从阴极流道底部开始,以沿气体扩散层厚度方向侵入为先,直到到达气体扩散层底部,随后气相才向流道肩部水平延伸侵入。蒸发速率随气体扩散层中水饱和度的变化可分为陡降、缓降、持平、再缓降四个阶段。
A pore network model was used in this paper to simulate the drying process in the gas diffusion layer(GDL) of proton exchange membrane fuel cell(PEMFC) with the influence from current collector.The simulation results revealed that capillary force dominate the drying process in GDL and the land of current collector hinders the drying in the pores underneath the land.The drying rate with respect to water saturation can be characterized by four periods:rapid drop period, slow drop period,constant rate and further falling periods.