Numerical Investigation of the Effect of Thermal Interface Material on Thermoelectric Generator Performance

Abstract

Thermal interface materials are mostly applied in microelectronics, power electronics and LED lighting fields. Another important area of application of thermal interface materials, although less researched, is thermoelectric generators. Thermoelectric generators basically provide electricity production with temperature difference and its application in waste heat recovery is getting more attention day by day. In this study, different from the studies in the literature, numerical calculations were made by considering the effect of thermal interface materials on the performance of thermoelectric generator. Numerical results were compared with experimental results obtained from the literature. Thermal greases with different heat conduction coefficients (2 W/m·K, 2.5 W/m·K and 3 W/m·K) and thickness (0.1 mm, 0.2 mm, 0.5 mm, 0.75 mm and 1 mm) were examined at different hot surface temperatures (75°C, 80°C, 85°C, 90°C, 95°C) as working parameters and the effect of these parameters on thermoelectric module performance was investigated. When the results were examined, it was determined that the experimental and numerical results were in good agreement at 0.5 mm thermal grease thickness. At this thickness, the maximum open circuit voltage, voltage at load, current, power output values occurred at hot surface temperature of 95°C and a thermal conductivity coefficient of 3 W/m·K. Under these conditions, the maximum open circuit voltage and power output were experimentally at 4.60 V and 0.84 W, respectively, while numerically at 4.32 V and 1.23 W. In all analyzes, the increase in temperature difference and the increase of thermal grease heat transfer coefficient increased the power output of the thermoelectric module, while the increase in thermal grease thickness decreased the power output. © 2022, TUBITAK. All rights reserved.