燃料电池在机械应力下的工作参数分布

针对质子交换膜燃料电池在机械应力下的气-液两相流进行数学模拟研究，建立了一个二维质子交换膜燃料电池非等温两相流多物理场稳态模型. 该模型综合考虑了固体力学、电化学、传热传质以及气液两相流的物理因素，研究了质子交换膜燃料电池在机械应力作用下的两相流分布.计算结果显示：在机械应力作用下，燃料电池肋板下方的多孔介质应力明显大于流道下方的应力，且在肋板和流道交界处下方的气体扩散层会产生明显的应力集中现象；随着电流密度的增加，阴极相对湿度逐渐增加，但阳极相对湿度会减小；液态水仅在阴极产生且主要在肋板下方的多孔介质内形成，其在阴极的饱和度随电流密度的增加而不断增加.

Working Parameters Distribution of Fuel Cell under Mechanical Stress

The mathematical simulation of gas-liquid two-phase flow of the proton exchange membrane (PEM) fuel cell under mechanical stress was studied. In this study, a two-dimensional, non-isothermal two-phase flow Multiphysics steady-state model of PEM fuel cells was established. The model comprehensively considered the solid mechanics, electrochemistry, heat and mass transfer and gas-liquid two-phase flow. The two-phase flow distribution of PEM fuel cells under mechanical stress was studied. The computational results showed that the stress of the porous medium under ribs was significantly greater than the stress under the flow channel. Stress concentration obviously occurred at the junction of the ribs and the flow channel. Liquid water was only condensed at the cathode and mainly formed in the porous medium under the ribs. As the current density increased, the cathode relative humidity gradually increased, however, the relative humidity of the anode decreased. Cathode liquid water saturation increased when current density increased.