Computational Investigation of Impingement Cooling of Thermoelectric Generators

Abstract

Designs of heat exchangers are quite often disconnected from the performance of thermoelectric generators (TEG). In the present work, the TEG and the heat exchanger are modeled in a coupled manner in a computational fluid dynamics environment (OpenFOAM). To this purpose, the previously developed OpenFOAM solver, tegFOAM, is extended by incorporating temperature dependent material properties in TEG, and conjugate heat transfer. In the TEG domain, the heat conduction and electric fields are solved in a coupled manner, whereas the convective heat transfer on the cooling side is coupled with the heat conduction in TEG. The implementation with respect to the temperature dependent material properties of TEG is validated by comparisons with experimental and computational results of other authors. For validating the applied prediction procedure for the convective cooling, a configuration out of the literature is investigated, which resembles a typical TEG cooling arrangement quite closely, where a single laminar slot jet is impinging onto a linear array of discrete heat sources. Subsequently, the complete, coupled model is applied to predict the performance of a TEG consisting of 16 elements.