The Influence of Suspension and Deposition on Pool Boiling Heat Transfer of Nanofluids: Experiment and Engineering Model Study

Abstract

Applications including heat exchangers, high power electronic components, and nuclear reactors now require heat transfer technologies that can achieve both high efficiency and compact footprints. Because nanofluids have advantageous heat transfer properties, they have a greater potential to replace conventional coolants. However, predicting nanofluid boiling heat transfer is still difficult. In order to compare the coupled effects of suspended and deposited nanoparticles with the single effect of deposited nanoparticles, the researchers conducted boiling heat transfer experiments. The findings demonstrated that suspended nanoparticles made the surface less wettable, while the deposited nanoparticles increased the wettability. The number of active nucleate sites and the frequency of bubble detachment increase due to the suspension and deposition of nanoparticles, whereas the diameter of the bubble decreases. Based on the experimental data, predictive models for boiling heat transfer and bubble behavior were proposed, with a range of mass concentrations from 0.001% to 0.005% and heat flux between 60 and 130 kW/m2. Less than 30% was found to be the error margin between the experimental data and the predictive equations. It was discovered that the influence of deposited nanoparticles on boiling heat transfer was usually dominant, according to the predictions made by the proposed theoretical models.

Keywords: Suspension, deposition, bubble behavior, predictive model, contact angle