气体扩散层分层设计对PEMFC电堆性能影响研究

Research on Effect of Gas Diffusion Layer Layered Design on the Performance of PEMFC Stack

为了改善电堆不同电池单元之间的温度、反应物等的均匀性从而改善电堆性能和提升寿命,本文提出了一种在电堆不同电池单元气体扩散层设置不同的梯度孔隙率的改进方案。通过建立包含5层单电池的三维、非等温、单相的短电堆模型进行分析,研究发现孔隙率为0.4-0.5-0.6-0.5-0.4的方案可以最大程度改善边缘层和中间层单电池之间温度、氧气浓度、水浓度、膜电流密度等的差值,即提高电堆内部均匀性,且在缺气工况条件下亦是如此。

In order to improve the uniformity of temperature and reactants between different cells in the stack,thus improving the stack performance and extending the stack life,an improved scheme of setting different gradient porosity in gas diffusion layers of different cell units in the stack is proposed in this paper.A three-dimensional,non-isothermal,single-phase short stack model with five layers of cell units is established for analysis.It is found that the scheme with porosity of 0.4-0.5-0.6-0.5-0.4 can minimize the difference of temperature,oxygen,water molar concentration,membrane current density between the edge layer and the intermediate layer cell unit;thereby improve the internal uniformity of the stack,which is also the same trend under the operating conditions of gas shortage.