A comparative performance analysis of thermoelectric generators with a novel leg geometries

Abstract

Thermoelectric (TE) devices utilize the Seebeck effect to produce electricity from waste heat. The optimization of TE leg geometry and its structure has lately drawn more attention to improving TE power generators. This study uses the finite element method to examine thermoelectric generators' thermal reliability and performance (TEGs) for novel TE leg designs. New leg shapes, such as a cross-vertical and butterfly, are introduced and contrasted with the squared (conventional) leg and other leg shapes, such as trapezoidal, cross-horizontal, I-shaped, X-shaped, and Y-shaped. The design of the main geometric parameters, including structure, height, volume, and surface area of the thermoelectric leg, is discussed in detail. As the TE leg has a larger heated surface area, the results demonstrate that the cross-vertical and butterfly legs perform 39.2% and 30.4%, respectively, higher than the squared (conventional) shape. However, the square-shaped leg shows the least thermal stress compared to other designs, especially at high thermal gradients. For low-temperature gradients (Th < 100 °C), the new TE leg designs of the cross-vertical and butterfly structures exhibit thermal stresses below the yield stress of bismuth telluride, indicating that their use is suitable for upcoming low-temperature gradient thermoelectric system applications.