Application of Nano-Fluids to Heat Transfer Enhancement in Double-WalledReactor

摘要

Efficiently cooling of a reactor for an exothermic reaction can lead the efficiency to be increased, while reduces the size of the rector. In the present research, aqueous Nano-fluid of Al2O3 and CuO are used as heat transfer media flowing inside the reactor jacket to improve the heat transfer performance of a reacting system. Experiments have been performed to investigate the role of Nano-fluid in cooling of an exothermic reaction. The experimental facility provides conditions to control the generated heat during the reaction. Convective heat transfer coefficient and pressure drop of alumina/water and CuO/water Nano-fluids were experimentally measured. Nano-fluids were using two-step method at mass concentrations of 0.1-0.4%. The reactor is a stainless steel-made annular type, which is cooled by Nano-fluid flowing inside the annular section. For longer stability of Nano-fluids, surfactant and sonication were implemented. Results showed that by increasing the concentration of Nano-fluid and Reynolds number, the heat transfer coefficient increased. For CuO Nano-fluid, rate of enhancement for the convective heat transfer coefficient was 13% at 0.3% in comparison with the base fluid. While for aluminum Oxide at wt. %=0.4, the enhancement rate was 11.7%. Utilizing the Nano-fluid instead of traditional coolants, (e.g., water) resulted in a small penalty for the pressure drop. Higher level of pressure drop was registered for alumina Nano-fluid at wt%=0.4, which was 12% more than that of reported for the distilled water?