Converting chemical energy into electricity is done by an electrochemical device known as a fuel cell. Thermal stress is caused by high operating temperature, between 700 and 1,000°C, of solid oxide fuel cell (SOFC). Thermal stress is the main cause of crack initiation and crack propagation. This phenomenon may cause gas leakage, structure instability and cease operation of the SOFC before its lifetime. The aim of this study is to present a method that predicts the initiation of cracks in an anisotropic porous planar SOFC. The coupled governing nonlinear differential equations are solved numerically as for heat transfer, fluid flow, mass transfer, mass continuity, and momentum. An in‐house computer code which is based on computational fluid dynamics, computational structural mechanics and extended finite element method is utilized and developed. This code, according to Darcy and Navier–Stokes thermofluid model, determines the temperature and stress distribution. The results show that the highest thermal stress occurs at the upper corners of cathode and at the lower corners of the anode. The maximum temperature occurs at the middle of the electrolyte cathode and electrolyte anode, while the maximum pressure occurs at the middle of the upper and lower section of the anode and cathode. In addition, the thickness of the cathode electrode at the left side is increased by 1.5%. Finally, the crack initiation occurs at the left side between the upper and lower corners of the cathode.

中文翻译：

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平面固体氧化物燃料电池裂纹萌生检测的数值研究

通过称为燃料电池的电化学装置将化学能转化为电能。热应力是由固体氧化物燃料电池（SOFC）的700至1,000°C的高工作温度引起的。热应力是裂纹萌生和裂纹扩展的主要原因。这种现象可能会导致气体泄漏，结构不稳定并在SOFC使用寿命之前停止运行。这项研究的目的是提出一种预测各向异性多孔平面SOFC中裂纹萌生的方法。对耦合的控制非线性微分方程进行数值求解，例如传热，流体流动，传质，质量连续性和动量。利用并开发了基于计算流体动力学，计算结构力学和扩展有限元方法的内部计算机代码。根据Darcy和Navier-Stokes热流体模型，此代码确定温度和应力分布。结果表明，最高的热应力发生在阴极的上角和阳极的下角。最高温度发生在电解质阴极和电解质阳极的中间，而最高压力发生在阳极和阴极的上部和下部的中间。另外，左侧阴极的厚度增加了1.5％。最后，裂纹的萌生发生在阴极上下角之间的左侧。结果表明，最高的热应力发生在阴极的上角和阳极的下角。最高温度发生在电解质阴极和电解质阳极的中间，而最高压力发生在阳极和阴极的上部和下部的中间。另外，左侧阴极的厚度增加了1.5％。最后，裂纹的萌生发生在阴极上下角之间的左侧。结果表明，最高的热应力发生在阴极的上角和阳极的下角。最高温度发生在电解质阴极和电解质阳极的中间，而最高压力发生在阳极和阴极的上部和下部的中间。另外，左侧阴极的厚度增加了1.5％。最后，裂纹的萌生发生在阴极上下角之间的左侧。