3D stack-up assembly tolerance analysis for sealing optimization of PEMFCs

Abstract

As elastic rubber seals are in contact with rigid metal bipolar plates (BPPs), multi-layer stack seals are critical to PEMFC safety. The precision of rigid-flexible seals is significantly affected by assembly errors. To reveal the transformation mechanism from BPPs manufacturing tolerances to PEMFC sealing, this study adopted semi-analytical modeling and numerical simulation. A deviation transfer model with three parameters (deviation size |r→|, deviation direction φr, rotation angle θr) was constructed on the basis of manufacturing tolerances to evaluate BPPs deviation. Numerical simulations were further conducted to obtain rubber-metal contact status. The effect of varying deviations on leakage was also investigated. It is found that: 1) φr causes various sealing behaviors in various sealing zones; 2) θr slightly affects leakage rates; 3) |r→| is crucial for optimizing the BPPs tolerance. The proposed method investigates the effect of 3D stack-up assembly errors on sealing performance and provides a theoretical foundation for the tolerance design and optimization of PEMFCs.