Joint optimization of leg configuration and fin structure in a two-stage segmented thermoelectric generator for enhanced 3E performance

Abstract

Existing research typically optimizes either the thermoelectric leg configuration or the fin structure independently, often neglecting the potential interactions between the two. This study proposes a novel two-stage segmented thermoelectric generator, examining the interplay between thermoelectric legs and fin structure and their impact on energy, exergy, and economic (3E) performance. Using the Taguchi method and Grey Relational Analysis, a joint optimization of thermoelectric legs and fin structure was conducted. The results reveal a significant interaction effect between the leg structure and fin thickness. The optimal leg structure is contingent on the fin thickness, and vice versa. When the area ratio between the upper and lower leg sections is 0.5, the optimal fin thickness is 1 mm; when the area ratio increases to 1, the optimal fin thickness decreases to 0.5 mm. However, the optimal fin spacing is not influenced by the leg structure. The optimized two-stage segmented thermoelectric generator exhibits superior 3E performance, with net power, exergy efficiency, and levelized energy cost reaching 19.36 W, 12.14 %, and 25.5 W/$, respectively. These values represent improvements of 32.3 %, 34.4 %, and 100.7 % over conventional two-stage thermoelectric generators. This study provides crucial design guidance for the joint optimization of fin and thermoelectric semiconductor structures.