Nanofluid-Enhanced Thermoelectric Generator Coupled with a Vortex-Generating Heat Exchanger for Optimized Energy Conversion

This study investigates the impact of nanofluids (TiO2, Fe3O4, Al2O3, and graphene) on thermoelectric power generation within a rectangular heat exchanger equipped with internal winglets. The integration of internal winglets in heat exchangers, alongside the use of nanofluids, is a recent strategy aimed at enhancing convective heat transfer. This numerical research analyzes fluid dynamics and temperature variations on both the cold and hot sides of the thermoelectric generator (TEG). Three different heat exchanger models are evaluated: the first model features a pair of winglets in both ducts; the second model only has winglets in the hot duct; and the third model does not include any winglets. The performance of the nanofluids is systematically compared with that of distilled water. The results show that the Al2O3 nanofluid produces the highest power output at 7.8461 watts, which is 1.5% greater than that of TiO2 and 1.22% higher than distilled water. Moreover, using Al2O3 in a heat exchanger with winglets in both ducts results in a 5% increase in power generation compared to a configuration without winglets and a 2% improvement over a model that has winglets only in the hot duct. This enhancement can be attributed to an increased heat transfer area and improved fluid mixing, which together facilitate more effective heat transfer to TEG.