Numerical simulation of a multi-tube automotive thermoelectric generator for heat transfer and power generation performance

To improve the performance of automotive exhaust thermoelectric generators, a numerical evaluation of automotive exhaust gas thermoelectric generators with multi-tube heat exchangers is carried out in this paper. The influence of complex flow states in corrugated tubes with different geometric structures on the device's heat transfer and power generation is analyzed. The calculation considers different mass flow rates of exhaust gas, heat transfer efficiency and entropy change based on power generation output and power generation efficiency. The results show that the increase of the height-diameter ratio of the corrugated tube is beneficial to the strength of the fluid such as the secondary flow. The rise in distance of the corrugated ring is encouraged to increase the influence range of the fluid such as the secondary flow. When the exhaust gas flow rate is 10–30 g/s, these changes can enhance the heat transfer and heat transfer efficiency compared with the smooth tube, but at the same time, the frictional resistance inside the tube will also increase. The power generation efficiency is increased to 1.2–2 times, and the maximum output power is 120W, which provides data support for optimising thermoelectric generators.