In order to enhance the performance of the automobile waste heat recovery system, a novel two-stage automobile thermoelectric generator with a cascade configuration along the temperature gradient of exhaust gas was designed. The corresponding integrated one-dimensional numerical model considering temperature-dependent thermoelectric materials was developed to predict the performance accurately. The impedance matching condition for the maximum output power was derived for the novel two-stage automobile thermoelectric generator. The developed model was demonstrated through comparisons with the reported experimental data and simulation results. The results indicated significant discrepancies in output power, conversion efficiency, and the temperature difference between the cold/hot sides of thermocouples for single-stage and two-stage configurations. The designed thermoelectric generator with the two-stage configuration could capture the temperature change along the flow direction of exhaust gas and obtain better performance by adjusting the length of the two-stage module. Compared to the traditional single-stage thermoelectric generator, the designed two-stage configuration could achieve the output power increments by 13.5% under the same working conditions. The effects of working conditions (exhaust gas temperature and mass flow rate) and TEG geometry size on the output power are studied. This work could provide some guidance on the design and performance enhancement of automobile thermoelectric generators.

为提高汽车余热回收系统的性能，设计了一种沿废气温度梯度串联配置的新型两级汽车热电发电机。开发了考虑温度相关热电材料的相应集成一维数值模型以准确预测性能。推导出了新型两级汽车热电发电机最大输出功率的阻抗匹配条件。通过与报告的实验数据和模拟结果进行比较，证明了开发的模型。结果表明，单级和两级配置在输出功率、转换效率和热电偶冷/热侧之间的温差方面存在显着差异。设计的两级配置热电发电机可以捕捉沿废气流动方向的温度变化，并通过调整两级模块的长度来获得更好的性能。与传统的单级热电发电机相比，设计的两级配置在相同工作条件下可实现输出功率增量13.5%。研究了工作条件（废气温度和质量流量）和 TEG 几何尺寸对输出功率的影响。这项工作可以为汽车热电发电机的设计和性能提升提供一些指导。