Research of structure and performance on passive cooling heat sink in TEG waste heat recovery system based on topology optimization

This study employs topology optimization techniques to enhance the structural design and performance of passive cooling heat sinks within thermoelectric generator (TEG) waste heat recovery systems. The topology optimization model aims to minimize the temperature on the heat sink's bottom surface and different fin structures are obtained by altering the Grashof number (Gr). The results show that, at low Gr numbers, fins are elongated and multi-branched, enhancing thermal conduction. Conversely, at high Gr numbers, fins are shorter with fewer branches, relying mainly on natural convection. Topology optimization markedly improves the thermoelectric performance of heat sinks. Compared to conventional straight-fin designs, the optimized heat sink increases the temperature differential by 8.8 %, boosts system output power by 20.1 %, and enhances thermoelectric conversion efficiency by 10.7 %, all while reducing material usage by 55.1 %. The study reveals that different heat sink configurations significantly affect heat transfer and fluid flow within TEG systems. Topology-optimized heat sinks exhibit superior temperature distribution and flow field optimization, though they may introduce increased local resistance.