Abstract

One of the major challenges of the future automotive development is to achieve the required reductions of the CO₂ emissions. Therefore, it is necessary to investigate all potential technologies for efficiency improvement. In a combustion engine, about 2/3 of the chemical energy of the fuel is dissipated as waste heat. Due to its high temperature level, the waste heat in the exhaust gas is very promising for the technology of thermoelectric generators (TEG). In this work the methodology for a holistic TEG optimization for automotive vehicle applications will be presented. Thereby, all system interactions between the vehicle and the TEG are modelled and the CO₂ reduction can be optimized within the vehicle system. Moreover the costs are calculated for each TEG design, and the method realizes an optimization of the cost–benefit ratio in a direct way. The optimization method is applied with a highly integrated TEG design, which has been developed to be compact and lightweight. Through the combination of improvements in TEG design and system optimization, a gravimetric power density of 267 W/kg and a volumetric power density of 478 W/dm^3 could be achieved. These power densities are about 900% and 700%, respectively, higher than the state of the art. The optimization method was applied exemplarily to a conventional vehicle (Volkswagen Golf VII) and a hybrid vehicle (Opel Ampera/Chevrolet Volt). As a result, reductions in consumption and CO₂ emissions of up to 2.2% for the conventional and 3.4% for the hybrid vehicle could be achieved within the worldwide harmonized light duty driving test cycle. The cost–benefit optimum is 81.3 €/(g/km) for the conventional vehicle and 54.8 €/(g/km) for the hybrid vehicle in charge sustaining mode.

中文翻译：

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汽车应用热电发电机的整体开发

摘要

未来汽车发展的主要挑战之一是实现所需的CO ₂排放量减少。因此，有必要研究所有可能的技术以提高效率。在内燃机中，燃料的化学能的约2/3作为废热消散。由于其高温水平，废气中的废热对于热电发电机（TEG）技术非常有前途。在这项工作中，将介绍用于汽车应用的整体TEG优化的方法。从而，对车辆和TEG之间的所有系统交互进行了建模，并确定了CO ₂可以在车辆系统内优化减排。此外，为每个TEG设计计算成本，该方法直接实现了成本效益比的优化。该优化方法与高度集成的TEG设计一起应用，该设计已开发为紧凑且轻巧。通过将TEG设计和系统优化方面的改进相结合，可以获得267 W / kg的重量功率密度和478 W / dm ^ 3的体积功率密度。这些功率密度分别比现有技术高约900％和700％。该优化方法示例性地应用于常规车辆（大众高尔夫VII）和混合动力车辆（欧宝Ampera /雪佛兰Volt）。结果，减少了消耗和CO ₂在全球统一的轻载驾驶测试周期内，传统汽车和混合动力汽车的排放量最高可达2.2％。在充电维持模式下，常规车辆的成本效益最佳值为81.3欧元/（g / km），混合动力车辆为54.8欧元/（g / km）。