气流流速对PEMFC流道水管理影响的数值模拟研究

Numerical simulation study on the influence of airflow velocity on water management of PEMFC flow channel

水管理是影响质子交换膜燃料电池(PEMFC)工作性能以及工作效率的关键技术。借助ANSYS建立一个以两相流为基础的流体体积函数(VOF)模型,通过计算水滴在不同入口速度下的流道里的运动状态来研究气流速度对于水管理的影响。结果表明,流速较低时,液滴容易在流道内坍塌,易造成液态水累积,阻塞阴极多孔电极,降低电池的工作效率。随着速度慢慢增大,液滴的形变会先减小,但是当风速过大时,液滴会逐渐破碎,破碎后的小液滴可能会滞留在流道内,从而造成电池工作效率降低。

Water management is a key technology to affect the working performance and efficiency of proton exchange membrane fuel cell(PEMFC).With the help of ANSYS,a two-phase flow based volume of fluid(VOF)model is established to study the effect of airflow velocity on water management by calculating the motion state of water droplets in different inlet velocities.The results show that the droplet collapses easily in the flow channel when the flow velocity is small,which can easily cause liquid water accumulation,block the cathode porous electrode and reduce the working efficiency of the battery.With the increase of the velocity,the deformation of the droplet will decrease first,but when the wind speed is too large,the droplet will gradually break.The broken droplets may remain in the flow channel,resulting in reduced battery efficiency.