Power Generation Efficiency of Thermoelectric Elements with a Trapezoidal Section

Abstract

This article proposes a method to improve the thermoelectric conversion efficiency by controlling the heat flow direction of a thermoelectric element (TE) with a trapezoidal section. A thermoelectric generator (TEG) generally consists of a rectangular parallelepiped element. In theory, the thermoelectromotive force E can be easily estimated from the Seebeck coefficient α and the temperature difference ΔT, namely, E = αΔT. Seebeck coefficient α and resistivity ρ are known to have temperature dependence. We fabricated a TEG with a trapezoidal section which modified temperature distribution by TE shapes. It also provided many high Seebeck coefficient regions. As a result, the output power of TEG with a trapezoidal section was increased by 63% due to heat flow directions. It was also increased by 10% higher than the rectangular parallelepiped TEG at 400°C.