The effect of separator thickness on defect detection inside Polymer Electrolyte Fuel Cell (PEFC) stack was investigated. The authors have been developing a method to detect the defects inside PEFC by measuring the magnetic field around the operating PEFC and performing inverse analysis. In the experiments conducted so far, a separator thickness of 12 mm was used. However, practical fuel cell stacks employ thinner separators. Therefore, the applicability of this defect detection method to practical stacks was examined through numerical simulations. Specifically, the magnetic flux density around the stacks with different separator thicknesses was calculated by 3-dimensional electrical field and static magnetic field analysis. and the feasibility of defect detection under these conditions was evaluated. The results revealed that as the separator thickness decreases, the difference in magnetic flux density due to the presence or absence of defects decreases. The results of inverse problem analysis using these magnetic flux densities indicate that it becomes difficult to identify defect locations by the current analysis method as the separator thickness is thinner than 12 mm.
ABE et al. (Wed,) studied this question.