Performance assessment of multi-stage thermoelectric generators on hypersonic vehicles at a large temperature difference

Thermoelectric generator (TEG) is one of the most promising electricity generation technologies, which converts temperature difference directly into electrical energy. Considering the large temperature difference caused by the special thermal environment of hypersonic vehicles, it is quite a potential application for the thermoelectric technology. In this article, a power generation scheme suitable for hypersonic vehicles has been proposed, which is based on the multi-stage thermoelectric generator. The hot fuel heated by aerodynamic heat or combustion heat dissipation, rather than the high-temperature and high-speed air flow is applied as the heat source of thermoelectric module. An optimal TEG model considering the flow in both heat source and cold source has been developed to predict the thermoelectric performance under a large temperature difference condition. The maximum conversion efficiency of 18.38% is obtained benefiting from the application of advanced thermoelectric materials. Besides, the influences of the geometry and operating parameters on maximum power output and corresponding conversion efficiency have been investigated. The results indicate that the cascade utilization of large temperature difference through multi-stage structure improves the thermoelectric performance of TEGs greatly. Both the maximum power output and the corresponding conversion efficiency increase with the inlet temperature of the heat source. This research provides a new method of the power generation on hypersonic vehicles. (C) 2017 Elsevier Ltd. All rights reserved.