PEMFC碳纸气体扩散层内气液两相流格子Boltzmann模拟

Liquid-Gas Flow in Carbon-Paper Gas Diffusion Layer of Proton Exchange Membrane Fuel Cell: A Lattice Boltzmann Simulation Study

为了提高质子交换膜燃料电池(PEMFC)水管理,本文借助多相流格子Boltzmann模型(LBM)模拟分析了PEMFC碳纸气体扩散层(GDL)内的气液两相输运过程,主要研究了GDL疏水性对气液两相流的影响。结果表明:液态水流路径不仅受到GDL结构形态的影响,而且受到材料疏水性影响。液态水在疏水性弱的GDL中不仅容易沁入,而且容易在孔隙中达到饱和;相反,在疏水性较强的GDL中,液态水很难突破沁入小尺寸孔隙,而从孔径较大的孔隙流通,从而形成毛细力主导的指进流动。

To improve the water management of proton exchange membrane fuel cell （PEMFC）, the two-phase （liquid water and air） transport in the carbon-paper gas diffusion layer （GDL） of PEMFC was simulated and analyzed by using the pseudopotential multiphase lattice Boltzmann model （LBM）, which mainly focused on the effects of GDL hydrophobicity on the two-phase transport. The results encompass： for a GDL of lower hydrophobicity, liquid water is easier to seep into the pore space, and thus reach a higher liquid saturation level in the GDL; while for a GDL of higher hydrophobicity, the liquid water can hardly enter the pores of smaller size, but flows along the pathways connecting the pores of relatively larger size, leading to the formation of a capillary-fingering flow.