Thermo-economic, exergetic and mechanical analysis of thermoelectric generator with hollow leg structure; impact of leg cross-section shape and hollow-to-filled area ratio

Abstract

Filled square cross-section shape is the common conventional structure for n-type and p-type legs of thermoelectric generators. However, other cross-section shapes with hollow structure can significantly increase the output power of thermoelectric generator. However, mechanical strength and economic considerations may still remain as the significant challenges and factors. Hence, in this research, different hollow cross-section leg shapes are investigated for thermoelectric generator from all thermal, economic, exergetic and mechanical viewpoints simultaneously through a 3D validated numerical simulation. Output voltage/power, energy-efficiency, exergy efficiency, Von-Mises stress, and the dollar/watt value are calculated for all mentioned structures and optimum conditions are identified. As a sample result, the triangular shape leg is able to generate up to 100% more power and better conversion/exergy efficiency (compared to the rectangular) at maximum input heat flux while mechanically less reliable design. Many other remarkable and interesting findings are provided in this manuscript.