Heat Management in Thermoelectric Power Generators

TL;DR

This paper challenges conventional heat management in thermoelectric generators by demonstrating that controlled heat loss can enhance efficiency and power output, depending on the Biot number, which guides insulation strategies.

Contribution

It introduces a modified Biot number as a criterion for optimal heat loss management, showing that strategic heat leakage can improve thermoelectric performance.

Findings

For Bi<1, sidewall cooling improves efficiency.

For Bi>1, sidewall cooling reduces efficiency.

Controlled heat loss can be beneficial for thermoelectric power generation.

Abstract

Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show that if Bi<1, cooling from sidewalls increases the efficiency, while for Bi>1, it lowers the conversion efficiency.