考虑装配偏差的质子交换膜燃料电池密封结构失效数值研究

Numerical Study on Sealing Structure Failure of Proton Exchange Membrane Fuel Cells Considering Assembly Deviation

质子交换膜燃料电池(PEMFC)的密封结构组件在装配过程中不可避免地存在错位偏差,影响电堆的性能和安全性。为研究装配过程中密封构件几何结构和材料参数对密封结构失效的影响,建立PEMFC装配过程中的密封结构数值模型,采用滑移距离和滑移角为评判密封结构失效指标,讨论垫片的硬度、尺寸和膜电极(MEA)框架厚度、材料弹性模量对密封结构失效的影响。结果表明:滑移距离和滑移角随着垫片硬度、垫片厚度的增大而增大,随着垫片宽度、MEA框架厚度和材料弹性模量的增大均减小,这表明密封构件的几何参数和材料参数对密封结构的稳定性具有重大影响;选择硬度和厚度较小、宽度较大的密封垫片,较厚和弹性模量较大的MEA框架可以降低错位偏差对密封结构的影响,扩大结构容许的装配误差范围。研究结果有利于对密封结构失效的理解,也可用于指导PEMFC装配工艺的设计。

The sealing structure components of proton exchange membrane fuel cells(PEMFCs)inevitably have misalignment deviations during assembly,which affect the performance and safe operation of the stack.To study the influence of the geometry and material parameters of the sealing components on the failure of the sealing structure during the assembly process of PEMFCs,a numerical model of the sealing structure in the assembly process was established.The slip distance and slip angle were used as the failure indicators to judge the sealing structure,and the influences of the gasket hardness and size,the thickness and material elastic modulus of membrane electrode(MEA)on the failure of the sealing structure were discussed.The results show that the slip distance and slip angle increase with the increase of gasket hardness and thickness,and decrease with the increase of gasket width,MEA frame thickness and material elastic modulus,which indicates that the geometric and material parameters of the sealing component in PEMFC have a significant impact on the stability of the sealing structure.The selection of sealing gaskets with smaller hardness and thickness,and larger width,as well as MEA frames with larger thickness and higher elastic modulus,can reduce the impact of misalignment deviation on the sealing structure and expand the allowable assembly error range of the structure.This research is beneficial to the understanding of seal structure failure,and can also be used to guide the design of PEMFC assembly processes.