Experimental and Numerical Study on the Effect of Interfacial Heat Transfer on Performance of Thermoelectric Generators

Abstract

The application of thermoelectric generator (TEG) systems in waste heat recovery has attracted more and more attention. In this work, the effect of interfacial heat transfer on the performance of TEG module was experimentally and numerically investigated. Three kinds of thermal greases with thermal conductivities of 2.0, 2.5, and 3.0 W/(m∙K) were used as thermal interface materials (TIMs) to improve interfacial heat transfer at different external pressures ranging from 0.1 to 0.4 MPa. The open-circuit voltage, output power, and thermal interfacial resistance were measured at different experimental conditions. It was found that the performance of the TEG module can be greatly improved by using thermal greases as TIMs. The open-circuit voltages increased from 1.73 to either 3.07, 3.4, or 3.57 V with k = 2.0, 2.5, and 3.0 W/(m∙K) thermal greases respectively used as TIMs when the temperature difference was 60 °C and external pressure was 0.1 MPa. However, the performance of the TEG was slightly affected by external pressure when thermal greases used as TIMs. The open-circuit voltages were 3.07, 3.13, 3.17, and 3.20 V at external pressures of 0.1, 0.2, 0.3, and 0.4 MPa when the temperature difference ΔT = 60 °C and k = 2.0 W/(m∙K) thermal greases were used as TIMs.