Explicitly Accounting for the Heat Sink Strengths in the Thermal Matching of Thermoelectric Devices. A Unified Practical Approach

Abstract

Thermal matching of thermoelectric generators (TEGs) to their heat sinks is well known to be a critical issue in the development of efficient harvesters. It is slightly less obvious that the development of suitable novel materials would possibly take advantage of their contextualization to prospective scenarios of deployment. In this communication a novel unified analysis of the heat equation is proposed. The thermal system was embedded into a thermostat while the heat source was taken as a part of the system itself, also explicitly accounting for the heat dissipation. A continual transition of thermal matching conditions from those predicted under Dirichlet boundary conditions (BCs) to those obtained under Neumann BCs was found, depending on the strength of the heat source and on the thermal resistances of the circuit branches. In all cases it was found that, independently of the thermal or thermoelectric circuit geometry, no single material may provide optimal TEG power density for any heat source strength and branch resistance.