摘要
基于数值重建的碳纸气体扩散层(GDL)三维微结构,采用格子玻尔兹曼方法(LBM)模拟了质子交换膜燃料电池(PEMFC)GDL内的气液两相流,详细研究了聚四氟乙烯(PTFE)含量及分布对GDL内两相输运的影响。计算结果发现:PTFE非均匀分布(靠近气流通道侧含量更多)时GDL内更容易积水;PTFE含量较多时GDL内积累的液态水含量较少。基于计算结果推导了气液两相相对渗透率,分析发现:PTFE含量及分布对气相相对渗透率影响较小;液相饱和度小于0.8时,PTFE含量较低时液相相对渗透率较高,而当液相饱和度大于0.8时,PTFE含量较高时液相相对渗透率较高;与PTFE非均匀分布时相比,PTFE均匀分布时液相相对渗透率较高。
The lattice Boltzmann method is employed to simulate the liquid-gas flow in the gas diffusion layer（GDL） in proton exchange membrane fuel cell（PEMFC）.Based on the computer generated 3 dimensional GDL,the impact of polytetrafluoroethylene（PTFE） content and distribution on liquid-gas flow in GDL is studied in detail.The results show liquid water is easier to be stuck and to accumulate inside the GDL when PTFE is non-uniformly distributedin the GDL（i.e.,withmore PTFE neighboring to the GC）;the liquid saturation diminishes with the increase of PTFE content in GDL when PTFE is uniformly distributed.Based on the resultsof simulated two-phase flow,the relative permeability（Kr） of each phase is derived at different phase saturations.The gas relative permeability（Krg） is less influenced by the PTFE content and distribution comparing to the liquid relative permeability（Krl）;the Krl is larger in the GDL of lower PTFE content when the liquid saturation is lower than 0.8,but when the liquid saturation is higher than 0.8,it is smaller compared with that in the GDL with higher PTFE content;in addition,the Krl is lager in the GDL with PTFE uniformly distributed.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2016年第7期1475-1483,共9页
Journal of Engineering Thermophysics
基金
广东省自然科学基金重大基础培育项目(No.2015A030308019)
广州市科技计划项目(No.2014J4100217)
