Tubular solid oxide fuel cells (TSOFCs) generate high-grade waste heat during operation, but the existing waste heat recovery technologies designed for flat solid oxide fuel cells cannot be directly applied to TSOFC due to the geometry mismatch. To efficient harvest the waste heat, a new geometry-matching hybrid system including TSOFC and annular thermoelectric generator (ATEG) is synergistically integrated to evaluate the performance upper limit. A mathematical model is formulated and verified to describe the hybrid system by considering various thermodynamic-electrochemical irreversible effects. Key performance indicators are established to assess the potential performance. Calculations show that the peak power density and corresponding efficiency of the proposed system are enhanced by 20.39 % and 13.89 %, respectively, compared to a standalone TSOFC. Furthermore, the exergy destruction rate is reduced by 7.04 %. Extensive sensitivity analyses indicate that higher operating temperatures enhance the system’s performance, while larger electrode tortuosity negatively affects it. Additionally, various optimization paths of ATEG are explored to improve the system performance, including considerations such as the number of thermocouples, leg radial width, leg thickness, or annular shape parameter. The three-objective optimization yields an efficient design solution for the entire system, offering valuable insights for its design and operation.

中文翻译：

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基于管状固体氧化物燃料电池和环形热电发电机的混合动力系统性能预测与操纵策略


管状固体氧化物燃料电池 （TSOFC） 在运行过程中会产生高品位的余热，但由于几何不匹配，现有的扁平固体氧化物燃料电池设计的余热回收技术无法直接应用于 TSOFC。为了有效地收集废热，包括 TSOFC 和环形热电发电机 （ATEG） 在内的新型几何匹配混合动力系统被协同集成，以评估性能上限。通过考虑各种热力学-电化学不可逆效应，制定并验证了描述混合系统的数学模型。建立关键绩效指标以评估潜在绩效。计算表明，与独立的 TSOFC 相比，所提出的系统的峰值功率密度和相应的效率分别提高了 20.39 % 和 13.89 %。此外，用能破坏率降低了 7.04 %。广泛的敏感性分析表明，较高的工作温度会增强系统的性能，而较大的电极弯曲会对其产生负面影响。此外，还探索了 ATEG 的各种优化路径以提高系统性能，包括热电偶数量、腿径向宽度、腿厚度或环形形状参数等考虑因素。三目标优化为整个系统提供了高效的设计解决方案，为其设计和运行提供了有价值的见解。