Investigation on cell-to-cell variations within methane-rich internal reforming solid oxide fuel cell (SOFC) stacks

Cell-to-cell uniformity is critical for maintaining the performance and durability of solid oxide fuel cell (SOFC) stacks. This study numerically investigates cell-to-cell variations in a 9-cell methane-rich internal reforming SOFC stack, focusing on the impacts of manifold configuration, backpressure, and fuel composition on thermal and electrochemical uniformity. Among the six configurations evaluated, the 3-in-2-out manifold achieved the best thermal uniformity, reducing the maximum stack temperature difference by 50.7 %. Under methane-rich conditions, increasing backpressure improved power output by 34.6 % but also intensified thermal gradients and voltage non-uniformity due to aggravated downstream fuel starvation. In contrast, stacks operating with hydrogen-rich fuel exhibited greater sensitivity to pressurization, resulting in more severe cell-to-cell variations due to the lack of buffering effects from internal reforming. Furthermore, under a constant volumetric fuel flow rate, reducing methane content initially improved thermal uniformity near the inlet but ultimately led to significant downstream fuel depletion and voltage loss. Within the scope of this study, maintaining a methane content above 12 % was found to support more stable and uniform stack operation. These findings highlight the trade-offs between performance, thermal behavior, and cell-to-cell consistency, offering practical guidance for the design and operation of high-power SOFC stacks.     «

Cell-to-cell uniformity is critical for maintaining the performance and durability of solid oxide fuel cell (SOFC) stacks. This study numerically investigates cell-to-cell variations in a 9-cell methane-rich internal reforming SOFC stack, focusing on the impacts of manifold configuration, backpressure, and fuel composition on thermal and electrochemical uniformity. Among the six configurations evaluated, the 3-in-2-out manifold achieved the best thermal uniformity, reducing the maximum s...     »