Optimizing geometry of linear thermoelectric generators for enhanced performance

Abstract

Thermoelectric conversion technology enables the direct transformation of thermal energy into electrical energy. Thermoelectric generator (TEG) based on this technology offer numerous advantages and have been widely utilized. Conventional TEGs tend to develop significant thermal stress concentration on the hot side during operation, thereby shortening TEG lifespan. Recent studies have proposed linear TEG structures that partially relieve stress concentrations but have very limited heat transfer efficiency. Moreover, the impact of thermoelectric leg geometry on the performance of linear TEGs has not been fully investigated. In this study, a novel linear TEG structure is proposed, based on the existing linear design. Numerical simulations indicate that the proposed structure reduces thermal stress and deformation by 54.3 % and 18.6 %, respectively, and increases the maximum output power to 119.17 mW, representing a 6.59 % improvement. The results also reveal that stress and deformation are primarily concentrated along the edges of the thermoelectric legs. Based on this observation, eight leg geometries were designed and analyzed to further optimize performance. The thermal stress and distortion of the optimized configuration are further reduced to 62.96 % and 19.11 % respectively. Among these, the cylindrical leg design demonstrated the highest conversion efficiency. Finally, cross-validation confirmed the effectiveness and robustness of the geometric optimization strategy for linear TEG structure.