Performance analysis of Alwater nanofluid with cationic chitosan dispersant

Abstract

This study aimed to investigate the effect of the cationic chitosan dispersant on the thermal conductivity, dispersion, and the suspension of 15 nm Alwater nanofluid. The study employed two-step method to mix the Alpowder, deionized water, and dispersant to conduct an experiment of the settling properties and thermal conductivity of nanofluid in a stable environment, analyzing the adhesion of nanofluid to copper pipe walls in practical operations. The results indicated that 1.0 wt.% Alwater nanofluid with 0.05 wt.% cationic chitosan dispersant increased its thermal conductivity up to 4.1% and 12.6% compared with nanofluid with deionized water at the temperature of 15°C and 55°C. At the flow ratio of 2 L/min, the overall heat conductivity improved by 8.3% and 17.4%, respectively, under 60 W and 150 W heating power. The solution performed better in dispersion and suspension than that in the original sample with no cationic chitosan dispersant. The cationic chitosan dispersant, as a result, was proved to improve the dispersion and suspension of nanofluid. It also helped to reduce the frequency of nanoparticles sticking to the pipe wall, increasing the practicability of nanofluid. © 2013 T. Y. Chen et al.