Experimental Investigation of Heat Transfer Enhancement using Nanofluids in a Heat Exchanger

Abstract

Heat exchangers are used in thermal systems like power stations, refrigerators, automobile cooling and electronic thermal management. The thermal performance of conventional heat transfer fluids, however, is constrained by the low thermal conductivity of water, ethylene glycol and oil. Colloidal suspension of nanoparticles (1 100 nm) in base fluids known as nanofluids have become potential alternatives because they possess improved thermal conductivity and convective heat transfer properties. In this research work, the heat transfer enhancement capacity of nanofluids is experimentally studied by a heat exchanger of laboratory scale. Nanoparticles of metal oxides were suspended in a base fluid with the different volume concentrations and the experiments performed in controlled flow conditions. The Nusselt number, heat transfer coefficient, pressure drop, and thermal performance factor were taken into consideration. These findings indicate that the performance of heat transfer can be increased with the concentration of nanoparticles, albeit with a moderate increase in pressure drop.Although improvements are foreseen, such practical drawbacks as nanoparticle agglomeration, long-term stability, enhanced pumping energy, and economic viability are critical issues in the high-level application. Future studies ought to concentrate on the optimization of nanoparticle size and shape, enhancing dispersion stability with surfactants or surface modification methods, performing long-term durability examination, and generating predictive correlations of large scale uses. Cost-effective and sustainable nanofluid preparations will be necessary to commercialization.