Design optimization of split fins in heat pipe-based thermoelectric generators

In this study, a novel split fin for automobile thermoelectric generators (ATEGs) is developed. Compared to plate fins, the split fin's larger heat transfer area significantly improves heat absorption performance. Additionally, a hybrid numerical model is developed to predict ATEG's performance and its accuracy is experimentally validated. The standard uncertainties of the measuring instruments used in the experiment are 0.23 % K, 0.12 % V, and 2.89 % m/s. Based on this model, the effects of the splitting angle (α) and vent height (h) on the ATEG's performance are investigated in detail. The results show that increasing α and decreasing h can improve ATEG's output power, but this also significantly increases back pressure loss. With net power as the optimization metric, the fin's optimal structural parameters are determined to be α = 22.5° and h = 24 mm, resulting in a net output of 95.68 W for the ATEG. In addition, the split fin is incorporated into a novel ATEG with heat pipes, which markedly enhances both the temperature and temperature uniformity of the heat exchanger and heat pipe. Compared to the plate fin, the split fin increases the net power and output power of the novel ATEG by 18.32 % and 22.61 %, respectively. The results of this research provide guidance for designing novel fins to enhance the ATEG's performance.