Analysis of assembly and thermal stress in kW scaled SOFC stacks

• Published in: International communications in heat and mass transfer Vol. 163; p. 108702
• Main Authors: Zhou, Ruidong, Cai, Weiqiang, Sun, Kaihua, Liu, Fangzheng, Yuan, Jinliang
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2025
• Subjects: Assembly load; Computational fluid dynamics (CFD); Homogenization method; Solid oxide fuel cell (SOFC) stack; Thermal stress; Thermal stress; Homogenization method; Solid oxide fuel cell (SOFC) stack; Computational fluid dynamics (CFD); Assembly load
• ISSN: 0735-1933
• DOI: 10.1016/j.icheatmasstransfer.2025.108702

A full-scaled and -structured model is developed and applied for a 36-cell stack of anode-supported solid oxide fuel cell (SOFC), by utilizing a homogenization method for flow channels/ribs with the objective of evaluating assembly and thermal stress. When the thermal stress is only considered, the maximum stress within the PEN (the so-called electrolyte sandwiched by electrodes) is observed in the electrolyte layer near the middle cell, manifesting as tensile stress. Upon simultaneous consideration of the assembly load and thermal stress, the maximum stress is found at the anode of the top-end cell characterized as the compressive one which is approximately 1.7 times bigger comparing with the case when only thermal stress is considered. Furthermore, the scale of the combined stress within the stack increases under the assembly load and thermal stress, while the internal distribution of these tensile and compressive stresses is subject to a redistribution. Due to edge effects, the extent of the stress distribution imparted by the assembly load attenuates from the top- and bottom-end cells towards those in the middle. The variation trend of the stress under different inlet flow ratios exhibits similarities when comparing the superposition of assembly load and thermal stress. This study underscores the significant impact of both mechanical and thermal loads on the performance of SOFC stacks, aiming to offer valuable insights for the development of a more efficient and stable energy conversion system.