The automobile exhaust energy can be recovered by the thermoelectric module generator(TEG). Owing to the complex urban traffic, the exhaust gas’s temperature fluctuations are resulted, which means the unstable hot-end temperature of the TEG. By installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, it is possible to appropriately reduce the temperature fluctuation, but there is still a fluctuation of the TEG’s power output. Then by adding voltage filter circuit (VFC) after the TEG, the power output stability can be improved.
This research uses SHCM and VFC to improve the stability of the exhaust gas generation. Firstly, the three-dimensional heat transfer model of the exhaust pipe thermoelectric power generation system is established. The heat capacity materials with low thermal resistance and high heat capacity were selected as the research object based on previous research. Secondly, the fluctuation relationship of the exhaust temperature over time is established. Then, the effect of the VFC without SHCM method, the effect of the SHCM without VFC method and the effect of the SHCM with VFC method on the TEG power generation stability is analyzed.
The results show that, by installing SHCM before TEG, TEG hot-side temperature fluctuations can be reduced, while TEG power generation stability is improved. By adding VFC after TEG, the voltage through VFC tends to be stable and can be better used by vehicle’s circuit load. By adding SHCM and VFC simultaneously, the power generation stability of the exhaust gas power generation system can be significantly improved. SHCM storages the heat energy of exhaust gas, which makes TEG produce more electrical energy. But, VFC consumed some power generated by TEG. This shows that the VFC regulator needs consuming energy to stable voltage output, so that TEG net power generation has declined.