Experimental Investigation on Pool Boiling Heat Transfer Performance Using Tungsten Oxide WO3 Nanomaterial-Based Water Nanofluids.

Mohammed Saad Kamel,Ferenc Lezsovits

doi:10.3390/ma13081922

Abstract

This study aims to experimentally investigate the pool boiling heat transfer coefficient behavior using tungsten oxide-based deionized water nanofluids and comparing them to deionized water as conventional fluid. The influence of different dilute volumetric concentrations (0.005%–0.05% Vol.) and applied heat fluxes were examined to see the effect of these parameters on the pool boiling heat transfer performance using nanofluids from a typical horizontal heated copper tube at atmospheric pressure conditions. Results demonstrated that the pool boiling heat transfer coefficient (PBHTC) for both deionized water and nanofluids increased with increasing the applied heat flux. The higher PBHTC enhancement ratio was 6.7% for a volume concentration of 0.01% Vol. at a low heat flux compared to the deionized water case. Moreover, the PBHTC for nanofluids was degraded compared to the deionized water case, and the maximum reduction ratio was about 15% for a volume concentration of 0.05% Vol. relative to the baseline case. The reduction in PBHTC was attributed to the deposition of tungsten oxide nanoflakes on the heating surface during the boiling process, which led to a decrease in the density of the nucleation sites.

Highlights

Boiling heat transfer is a significant heat transfer mode among other heat transfer modes due to the large heat quantity that could be removed by the latent heat of vaporization in small temperature differences
Results demonstrated that the pool boiling heat transfer coefficient increased with the presence of alumina nanofluid compared to base fluids and this improvement considerably improved with a higher volume fraction of nanoparticles
Prior to discussing our obtained results, the pool boiling apparatus and procedure should be validated to ensure the accuracy of the present results

Summary

Introduction

Boiling heat transfer is a significant heat transfer mode among other heat transfer modes due to the large heat quantity that could be removed by the latent heat of vaporization in small temperature differences. Intensifying heat transfer performance during the boiling process is essential for saving energy and keep those systems durable. Many efforts have been made to experimentally study the pool boiling heat transfer performance with various working fluids involving pure liquids [4,5], refrigerants [6,7], and mixtures liquids [8,9,10]. Other studies have been conducted by surface heating modifications to enhance the pool boiling heat transfer performance [11,12,13,14]. One of the alternative ways to improve the thermal conductivity of the working fluid is to use nanofluids, which were introduced in 1995 by Choi and his team [15].

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Conclusion