Study of the geometry and structure of a thermoelectric leg with variable material properties and side heat dissipation based on thermodynamic, economic, and environmental analysis

Thermoelectric generator (TEG) without moving parts, refrigerants, and direct carbon emissions is the most promising way to reduce carbon dioxide. The economy and thermal efficiency of TEG are seriously inhibited by geometry and structure, while existing studies have not investigated the effect of geometric and structure on output characteristics when the model considers the effect of side leg dissipation and variable properties. This paper proposes a one-dimensional model considering the effect of Peltier heat, conductive heat, Joule heat, Thomson heat, side leg dissipation, and temperature dependence for variable and conventional geometric and structures for 8 different materials. The effects of operation parameters, geometry parameters, and structures on thermodynamic, economic, and environmental performances are studied. The higher hot source temperature and shorter leg length benefit comprehensive performance. Increasing side leg dissipation decreases efficiency. When the fin parameter (L(heP/λA)0.5) is below a specific value, increasing side leg dissipation can promote the output power, economic and environmental performance. Compared to the traditional structure, the output power and efficiency of new configurations are increased by 1.01–3.59 and 1.03–4.57 times, respectively; The cost and CO2 emission reduce by 1.0–72.1% for low hot source temperature and figure of merit (ZT) material.