Abstract:

A three-dimensional non-isothermal numerical model was developed for proton exchange membrane fuel cells (PEMFCs) with conventional and interdigitated flow fields.The heat and mass transfers and the electrochemical reactions of reactant gases in fuel cells were included in the model.The investigation was concentrated on the electro-osmotic drag and the diffusion effects of liquid water in the membrane, and the species transport in porous media.The effects of transport limit of oxygen and water transport in the membrane on the cell performance were analyzed and discussed.The results indicated that the interdigitated design of flow channel enhanced the mass transport of gases in porous media and improved the output performance of fuel cell.However, the reduction of water at the interface of cathode catalyst layer could deteriorate the hydration degree of membrane, which required more effective water management to keep the membrane from dehydration.

摘要：

针对常规流场和交指型流场的质子交换膜燃料电池提出了三维非等温数学模型。模型详细考虑了电池内部的传热、传质和电化学反应，重点考察了多孔介质内的组分传递和膜内水的电渗和扩散作用，对氧气传递限制和膜内水迁移对电池性能的影响进行了分析和讨论。结果表明，流道的交指型设计加强了气体在多孔介质内的质量传递，提高了电池的输出性能，但相应地，阴极催化层界面水分的减少也使得膜的水合程度降低，这就需要更有效的水管理来防止膜脱水。