Authors: Tetsuya Mori | Kohei Yamazaki | Masaya Sasaki | Masashi Kishimoto | Hiroshi Iwai | Minoru Suzuki
Source: ECS Meeting Abstracts (article, 2025-11-24)
Field: Materials Science — Materials Chemistry

Development of Simulation Methods for Solid Oxide Fuel Cell Stacks Considering Thermal Interactions with Surrounding Components From a practical perspective, it is essential to incorporate thermal interaction with surrounding components, as it significantly influences solid oxide fuel cell (SOFC) stack behavior. Computational fluid dynamics (CFD) analysis is widely used in the design and analysis of SOFC stacks. However, CFD simulations for the entire stack require extensive computational resources, and few studies have considered peripheral components. One approach to reducing the computational load is developing a surrogate model of an SOFC stack using proper orthogonal decomposition (POD). POD is a technique for extracting dominant eigenmodes from multidimensional data, enabling efficient simulations by reconstructing a reduced-order model using only the most significant modes. Sato et al. [1] applied POD to an unsteady electrochemical potential analysis of an SOFC and developed a surrogate model. In our previous study [2], a detailed three-dimensional CFD analysis of an SOFC stack was conducted, and a surrogate model was developed utilizing POD [3] based on the results. This surrogate model provides computational results equivalent to full CFD analysis while significantly reducing computation time. In this study, a method for simulating the thermal interactions between the stack and peripheral components such as heat exchangers and reformers is developed using this approach within a CFD framework. The analysis object is a system in which an anode-supported planar SOFC stack is adjacent to a planar heat exchanger, with both components exhibiting thermal interactions, as shown in Figure 1. The heat exchanger operates in a counter-flow configuration, where air is supplied from the top, heated, and then directed into the air inlet manifold of the stack. In contrast, the hot post-reactor air from the stack enters from the bottom of the heat exchanger and is discharged from the top. The surface highlighted in red in Figure 1(b) is in direct contact with the stack. The stack consists of 21 cells, each comprising a Ni-YSZ anode layer, a YSZ electrolyte layer, and an LSCF cathode layer, as illustrated in Figure 1(d). Each cell has a square shape with an active area of 10 × 10 cm 2 . A CFD simulation was performed under different air supply temperatures for the heat exchanger and varying SOFC stack voltages, and based on the obtained data such as temperature distribution (see Figure 2(a)), a surrogate model of the SOFC stack was developed using POD [3]. The region enclosed by the dotted line in Figure 2(a) corresponds to the area modeled by the surrogate model. Figure 2(b) shows the schematic view of the coupled analysis, in which the heat exchanger is solved using CFD, while the SOFC stack is computed with a surrogate model. Coupled analysis provided the temperature distribution in the heat exchanger (see Figure 2(c)), temperature distribution at the electrode surface of the SOFC stack (see Figure 2(d)), and current density distribution (see Figure 2(e)). While a full CFD simulation of the entire SOFC stack and heat exchanger required approximately 10 hours to complete, the proposed surrogate model approach achieves convergence in under one minute, demonstrating a substantial reduction in computational time. Overall, a method for efficiently analyzing thermal interactions between an SOFC stack and surrounding components by coupling a surrogate model with CFD analysis. While this study focused on a heat exchanger as the surrounding component, the proposed method is applicable to multiple peripheral elements, including reformers. Acknowledgement This research was conducted as part of a collaborative project funded by the Daigas Group. We extend our gratitude to Professor Kenjiro Terada (Tohoku University), Associate Professor Mayu Muramatsu (Keio University), and Dr. Masami Sato (Mechanical Design Co., Ltd.) for their guidance and advice on surrogate modeling. References [1] Masami Sato, et al., “Development of surrogate model of electro-chemical potential analysis using proper orthogonal decomposition,” JSME M&amp;M Materials Mechanics Conference (2021). [2] Masaya Sasaki, et al., ”Development of 3D surrogate model of SOFC stacks and assessment of stack compactness,” JSME Thermal Engineering Conference, F34 (2024). [3] K. Beggs, "POD-RBF: A Python Package for Surrogate Modeling using Proper Orthogonal Decomposition and Radial Basis Functions," [Online]. Available: *https://pypi.org/project/pod-rbf/* (Accessed: February 4, 2025). Figure 1 Figure 2 Stack (abstract data type) ; Computational fluid dynamics ; Solid oxide fuel cell ; Heat exchanger ; Thermal ; Planar ; Computation ; Reduction (mathematics) Advancements in Solid Oxide Fuel Cells ; Modeling and Simulation Systems ; Model Reduction and Neural Networks