Development and Optimization of a TEG-system for the Waste Heat Usage in Railway Vehicles

The fuel consumption of diesel electric locomotives is the crucial factor for the vehicle's life cycle costs (LCC) and its CO2 emissions. Assuming that most components in railway vehicles are technically quite mature, innovative solutions like thermoelectric generators (TEG) need to be considered. This work shows the development and optimization of high power TEG for diesel electric locomotives, complying with the challenges of low LCC, high power density and sufficient thermo-mechanical stability. Therefore, a flexible and double-sided bondable Bi2Te3 based module is introduced and optimized with regard to the power density and mechanical strength. The module is virtually integrated into a waste heat exchanger which is also geometrically optimized to achieve a high power output without exceeding a maximum exhaust gas back pressure. The introduced optimization process finds a mechanical durable module with increased power density for the particular application, although the results of the TEG analysis show, that the system efficiency is still low but increasable by certain changes in the system design.