装配压力对燃料电池扩散层影响的研究

Effect of Assembly Force on Gas Diffusion Layer for Proton Exchange Membrane Fuel Cell

通过建立三维多流道质子交换膜燃料电池模型,对装配压力和流道重合度影响下气体扩散层产生的弹性形变进行研究。研究结果表明,随着装配压力的增加,脊部下方的气体扩散层会发生不同程度形变,而流道下方则基本不发生形变。当流道重合度不为100%时,气体扩散层的形变会产生了一定程度的偏移,并使流道下方气体扩散层最大厚度超过其初始厚度,在流道中产生"堆积"现象,而且这种现象随着装配压力的增加而越来越严重。最终导致气体扩散层内部多孔结构发生变化,从而引起孔隙率、渗透率等传输参数的变化,给燃料电池水热管理带来新的问题。

A three-dimensional multi-flow channel proton exchange membrane fuel cell（PEMFC） model has been developed to investigate the deformation of gas diffusion layer（GDL） with different assembly force and different contact ratio of channel. The results indicate that the GDL under the land part changes significantly while the central region under the flow channel almost has no deformation with increasing assembly force. When the contact ratio of channel is not 100%, the deformation of GDL is not symmetrical due to the shear stress, and the thickness of GDL under the flow channel even exceeds its initial thickness, which produces the phenomenon of ＂embossment＂ in the flow channel. And with the increasing of assembly force, this phenomenon is more obviously. Finally, the porous structure of gas diffusion layer changes and thus the transport parameters such as porosity and permeability begin to change, which will bring new problems for water and thermal management of PEMFC.