燃料电池弹性体密封特性的若干影响因素

Some influence factors on seal property of an elastomer in fuel cells

针对燃料电池的橡胶弹性体密封问题,采用有限元法和Moony-Revlin超弹性本构模型首先分析了带摩擦光滑结构表面的橡胶弹性体密封特性,然后分析了密封槽侧壁反力、温度和表面粗糙度对燃料电池橡胶弹性体密封特性的影响,并给出了有关密封设计的经验公式。分析结果表明,临界密封压力只与橡胶圈的压缩量和密封面摩擦系数有关,与橡胶圈截面半径无关。密封夹紧力与橡胶圈半径成正比。在橡胶圈压缩量、半径和摩擦系数确定的情况下,两种橡胶圈在密封临界状态的夹紧力之比仅仅与橡胶硬度有关。温度变化和表面粗糙度对密封特性的影响非常显著,在密封设计过程中必须考虑这些因素的影响。

Focusing on elastomer seal problems in fuel cells, finite element meth od and Moony-Revlin hyperelastic constitutive model were used to firstly analyze the seal property of a smooth structure surface with friction. Then, the effect s of sidewall reaction force, temperature and surface roughness on the seal beha vior were studied. Some useful empirical equations were provided. The present st udy shows that there is a critical seal pressure which is only related to the co mpression ratio and the friction coefficient, but does not depend on the radius of the elastomer ring. However, the clamping force for seal is proportional to t he radius. If the compression ratio, radius and friction coefficient are unchang ed, the ratio of the clamping forces of two elastic materials is only dependent on the elastomer hardness. The effect of temperature and surface roughness on th e seal property is very large and has to be considered very carefully.