Improved performance of the thermoelectric generator by combining vapor chambers and circular fins

To enhance the output performance of thermoelectric generators, this paper proposes a design that integrates vapor chambers (VCs) with circular fins, in which circular fins enhance the convective heat transfer between VCs and the exhaust, while VCs compensate for the uneven temperature distribution caused by circular fins. Besides, a numerical model is developed to optimize the number nfin and width wfin of circular fins, targeting maximum net power. Results show that: (1) The integration of circular fins and VCs increases the output power of the system. Maximum output power and efficiency are achieved at nfin = 12 and wfin = 2.25 mm (2) With the increase of exhaust mass flow rate mex, an increase in nfin and a decrease in wfin are required to achieve maximum net power. (3) Compared with the conventional structure, the proposed thermoelectric generator achieves the maximum improvements of 224.22 % and 211.08 % in output power and net power, respectively. (4) Increasing the thermal conductivity of VCs alleviates the effect of temperature drop, with the temperature uniformity coefficient surpassing 0.98 for all mex values (15 g/s to 40 g/s) at the thermal conductivity of above 8000 W m−1 K−1. This paper offers a new design conception for thermoelectric generators.