Enhancement of the thermoelectric generator performance by varying thermoelectric n/p couple spacing

Enhancing the TEG performance by varying the n/p couple spacing ( S ) is studied at constant hot side temperature and heat flux boundary conditions. Thus, the values of S have varied in the range of 0.25 to 1.5 mm. Semiconductor materials, including silicon–germanium (SiGe) and bismuth telluride (Bi 2 Te 3 ), are adopted. To estimate the performance, a three-dimensional TE model is developed and numerically simulated. The predicted results are validated using the available experimental data. Results show that the performance of TEG is significantly impacted by lowering the n/p couple spacing S. At S = 0.25 mm and 1.5 mm using the SiGe, the output power is 140.60 ± ± 0.11% W and 44.33 ± ± 3% W, respectively, and the corresponding efficiency is 22.66 ± ± 1.8% and 12.27 ± ± 0.8% at hot side temperature ( T h ) of 1027 °C. The reverse tendency occurs when the heat flow is constant. At the heat flow of Q " = 225 kW m −2 , where S = 0.25 mm and 1.5 mm, the SiGe material produces output powers of 14.10 ± ± 0.8W and 50.97 ± ± 3 W, respectively, with corresponding efficiencies of 6.32 ± ± 0.5% and 22.83 ± ± 1.8%. Additionally, adopting the S = 0.25 mm design for SiGe makes the proposed TEG module approximately 38.69% more compact compared to the conventional TEG system, while delivering the same power output under constant hot side temperature ( T h ) conditions. Under constant heat flux conditions, the S = 1.5 mm design for SiGe results in a 42.02% reduction in the required semiconductor material.