Transient optimization of a segmented variable area leg geometry-based solar thermoelectric generator

Abstract

Research on thermoelectric (TE) pin segmentation has been explored in this paper. A very few scholars have improved the TE generator (TEG) performance by using tapered segmented pins. Further, the time dependent quantities have been neglected in the available literature. The errors of using steady-state assumptions in TEG analysis have also been shown by previous experimental studies. The true transient behavior of a tapered segmented pin TEG exposed to transient real-time solar flux has not yet been studied. Thus, the transient optimization of a tapered segmented pin TEG is conducted using ANSYS 2020 R2 commercial software. The optimized parameters are the solar concentration ratio, convective film coefficient, leg height and area. The key result of this study is that at 12 h, the power density and energy efficiency of the segmented TEG improves by 237.5% and 88.89%, respectively, when tapered TE pins are used. Also, for the proposed TEG, increasing the leg height from 1 mm to 5 mm reduces its power densities by 68.18% while increasing its energy efficiency by 127.63%. Thus, for maximum power densities and energy efficiencies, a leg height of 3 mm is selected as the optimum. Finally, for high temperature application, lead-telluride is preferred to bismuth-telluride in the cold segment.