Pool-Boiling Heat Transfer Characteristics of Al_2O_3-Water Nanofluids on a Horizontal Cylindrical Heating Surface

摘要

This research involved conducting an experiment on pool boiling characteristics of Al_2O_3-water nanofluid. The experimental concentration ranged between 0.00005 and 0.03 %vol. The pressure used was at 1 and 2 arm. The boiling surface was a horizontal copper cylinder with a diameter of 28.5 mm, a length of 90 mm, and surface roughness of 3.14μm. The main purpose of this research was to study the effect of the nanofiuid's concentration and pressure on the heat transfer coefficient and on heat flux, by comparing with water. Calibration of the experimental apparatus with water revealed that the experimental results corresponded to the prediction by Rohsenow's equation. Results from the experiment on pool boiling of nanofluids indicated that the heat transfer coefficient of Al_2O_3-water nanofluid was lower than that of water and tended to decrease when the concentration was higher.