PEMFC密封胶接触压力的均匀性研究及改善方法

Study on Uniformity of Contact Pressure of PEMFCs Sealant and Its Improvement Method

针对质子交换膜燃料电池密封胶接触压力分布均匀性的问题,采用Fujifilm公司的压力膜测试了4个单电池片数不同的电堆的密封胶接触压力分布,利用MATLAB中搭建的平台对测试结果可视化;并基于Mooney-Rivilin超弹性材料本构模型建立了密封胶平面和电堆截面的有限元模型;利用有限元模型,设计了带圆弧和圆环的密封胶平面结构参数;并给出了沿集成力方向利于接触压力均匀分布的不同层密封胶初始厚度修正值的计算方法.结果表明:单电池平面内密封胶接触压力的最大差值为1.2MPa;沿集成力方向,靠近端板处的密封胶接触压力较中间层数的大,且层数越多的电堆,处于同一层数的双极板与密封胶的接触压力越小;在接触面积一样时,加圆弧结构的密封胶在平面内的接触压力标准差比原来结构的标准差小41%,加圆环的比原来结构小30%;对于不同层数电堆,密封胶初始厚度修正后的接触压力值均在最佳值附近.

Aiming at improving the uniformity of sealant′s contact pressure distribution for the proton exchange membrane fuel cells,the contact pressure distribution in the four stacks with different layers was tested using a Fujifilm pressure membrane.The test results were visualized by using the platform built in Matlab.Based on the Mooney-Rivilin super-elastic material constitutive model,finite element models of the sealant plane and the stack cross section were established,which were used to design the sealant structure with arcs and rings.Equations for correcting the initial sealant thickness were given in which the uniformity of contact pressure along the integrated force was improved.The results show that the maximum difference in the contact pressure of the sealant in the plane is 1.2 MPa.Along the integrated force,the contact pressure near the end plate is greater than that in the intermediate layers and the more layer results in the lower contact pressure at the same layer.When the contact area is the same,the standard deviation of sealant pressure in plane with the arc structure is 41%less than that of the original structure,and the ring is 30%less than the original structure.For different layers of the stack,the contact pressure after correcting the initial thickness of the sealant maintains around the best.This study can provide a kind of sealing structure that maintains the consistent performance in the fuel cell stack.