中文摘要：

本文根据直接甲醇燃料电池（DMFCs）阴极运行工况特性，考虑一个简单的一维模型，分析水蒸气饱和凝结成水的条件，从而得到电池阴极从单相流动到两相流动的临界电流值。分析结果表明：阴极气体进口速度增大使临界电流密度增大；临界电流随阴极气体进口相对湿度的增加而线性下降；临界电流随流道变长而减小；电池运行温度高有利于提高电池的临界电流。

英文摘要：

A simple, one-dimension numerical simulation approach is presented to evaluation Director Methanol Fuel Cells （DMFCs）. The model is applied to simulate the cathode phase change threshold current density of a DMFC. Considering the water generation rate, water transport process and condensation of the fuel cell air cathode, a threshold current density can be identified. The simulative results reveal that： when the air velocity at he cathode inlet is increased, the threshold current density is increased, too; when the relative humidity of gas at the inlet is increase, the threshold current density is linearly decreased; longer cathode length and lower operating temperature correspond with lower threshold current density.