化工学报2013，Vol.64Issue(4)：1424-1430,7.DOI:10.3969/j.issn.0438-1157.2013.04.041
PEMFC阴极扩散层结构特性对水淹影响的数值分析
Numerical analysis on effect of diffusion layer characteristics on water flooding in PEMFC cathode
摘要
Abstract
GDL (gas diffusion layer) is one of the critical components of a fuel cell and its basic functions are to provide channels for diffusion of gas from fluid to catalyst layer and for drain of liquid water from catalyst layer to fluid. In order to meet service conditions, the understanding for structure-performance of GDL is very essential, such as key parameters structure, porosity, hydrophobicity, hydrophilicity, gas permeability, transport properties, water management and their roles. A mathematics model of ID and two-phase was built for GDL in cathode of proton exchange membrane fuel cell (PEMFC). A direct numerical procedure was applied for combined equations of the model and Leverett's and Fick's laws to analyze the profiles of liquid water saturation and oxygen concentration across the gas diffusion layer. The effect of GDL characteristics, such as porosity, thickness, contact angle and absolute permeability was discussed. The results show that its hydrophobicity is helpful for removal of liquid water. The effect of contact tangle on liquid water saturation and oxygen mass transfer becomes less and GDL porosity and thickness has little effect on liquid water saturation at the hydrophobic condition, but porosity and thickness of GDL play an important role in oxygen transfer. For practical use, both GDL porosity and thickness increase, there is no significant difference for limiting current density. Tafel slope and limiting current density predicted by the model agree well with the experimental observation from literatures.关键词
阴极扩散层/水淹/液体饱和度/极限电流密度/PEMFCKey words
cathode GDL/ water flooding/ liquid water saturation/ limiting current density/ PEMFC分类
信息技术与安全科学引用本文复制引用
李英,周勤文,周晓慧..PEMFC阴极扩散层结构特性对水淹影响的数值分析[J].化工学报,2013,64(4):1424-1430,7.基金项目
国家自然科学基金项目(20906007). （20906007）
