基于VOF模型的PEMFC蛇形流道气液两相流动模拟

Simulation of Gas-Liquid Two-Phase Flow in PEMFC Serpentine Channel Based on VOF Model

摘要: 水管理是质子交换膜燃料电池(proton exchange membrane fuel cell, PEMFC)中需要解决的关键问题之一，本文建立了三维两相的数学模型，利用VOF方法研究蛇形流道内液态水的输运。分析了挡板形状对流道内气液两相流的影响，结果表明，波浪形挡板更有利于液态水的输运，相比于传统的蛇形通道，液态水具有更快的传输速率；还进一步分析了波浪形挡板通道内壁面接触角和液滴大小及数量对液态水输运的影响，结果表明，气体扩散层(GDL)壁面和通道底面接触角为150˚，流道侧壁面接触角为70˚时，除水效果最佳，可以使液滴脱离GDL，防止液滴堵塞，有利于反应物向GDL内扩散。

Abstract: Water management is one of the key issues to be solved in proton exchange membrane fuel cells (PEMFCs), a three-dimensional two-phase mathematical model was established, and the VOF method was used to study the transport of liquid water in the serpentine channel. The influence of the baffle shape on the gas-liquid two-phase flow in the channel is analyzed, and the results show that the wave-shaped baffle is more conducive to the transmission of liquid water, and the liquid water has a faster transmission rate than the traditional serpentine channel; the influence of the contact angle of the inner wall of the wave-shaped baffle channel and the size and number of droplets on the transport of liquid water was further analyzed. The results show that when the contact angle between the wall surface of the gas diffusion layer (GDL) and the bottom surface of the channel is 150˚, and the contact angle of the sidewall surface of the flow channel is 70˚; the water removal effect is the best, and it can make the droplets detach from the GDL, prevent the droplets from clogging the GDL, and facilitate the diffusion of the reactants into the GDL.