3D multiphysics modeling and design optimization of a 25-layer Z-type SOFC stack

To address the performance and reliability requirements for high-power solid oxide fuel cell (SOFC) stacks, a three-dimensional coupled flow-thermal-electrochemical numerical model has been established to optimize a 25-layer Z-type SOFC stack design, The synergistic effects of Z-type inlet/outlet manifold layout and air flow distributing geometry over single-cell on the flow, temperature, and pressure distribution characteristics are systematically investigated. Preliminary results indicate that for a 25-layer medium-scale stack with a 2in1out configuration, the Z-type structure combined with a hybrid configuration of 7 square air flow channels and ribs could ensure good distributing qualities of both flow and oxygen within the stack. This provides critical structural design guidance for constructing high-performance, high-reliability modular high-power SOFC systems. The results show that without increasing the length of the current collection path, the contact area of the rib airway and cathode of the Z-type SOFC stack using square ribs increased by 17% (5 square) and 22.7% (7 square) respectively, and the optimized oxygen distribution range increased. The optimized structure demonstrates overall velocity enhancement, with maximum velocity increases of 2.2 m/s (7 square) and 3.4 m/s (5 square)，and verifies the effectiveness of structural adjustment in enhancing the uniformity of the flow field.