Additive-Manufactured Topology-Optimized Heat Sinks for Enhancing Thermoelectric Generator Conversion Efficiency

Abstract

Thermoelectric generators (TEGs) are gaining attention as a promising technology for waste heat recovery due to their ability to directly convert heat into electricity. However, their relatively low conversion efficiency limits widespread adoption. While efficient thermal management of TEGs is crucial to achieve high conversion efficiencies, less attention has been paid to this aspect compared to materials development. Efficient TEGs require efficient heat dissipation on the cold side of TEGs, demanding careful heat sink design. In this study, a topology optimization model was developed to design air-cooled heat sinks for TEG applications. The optimized heat sink was fabricated using additive manufacturing, and its performance was experimentally validated. When this topology-optimized (TO) heat sink is used for a commercial TEG, its output power and conversion efficiency are increased by 44.7% and 21.3%, respectively, compared to the case where the conventional rectangular-fin heat sink is used. This improved conversion efficiency is equivalent to a 27% increase in the device thermoelectric figure of merit (ZT). Numerical simulations revealed that the TO heat sink enhances temperature uniformity on the cold side of the TEG, further contributing to performance gains. These findings highlight the effectiveness of heat sink topology optimization in enhancing TEG conversion efficiency.

Keywords: Thermoelectric generator, Topology optimization, air-cooled heat sink, Additive manufacturing, forced convection