Surface effects of ribbon heaters on critical heat flux in nanofluid pool boiling

    Authors

    D. M. Vazquez;R. Kumar

    Comments

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    Abbreviated Journal Title

    Int. Commun. Heat Mass Transf.

    Keywords

    Critical heat flux; Nanofluid; Pool boiling; Deposition; Concentration; NANO-FLUIDS; CHF; WATER; THIN; Thermodynamics; Mechanics

    Abstract

    This paper deals with a study of enhanced critical heat flux (CHF) and burnout heat flux (BHF) in pool boiling of water with suspended silica nanoparticles using Nichrome wires and ribbons. Previously the current authors and other researchers have reported three-digit percentage increase in critical heat flux in silica nanofluids. This study investigates the effect of various heater surface dimensions, cross-sectional shapes as well as surface modifications on pool boiling heat transfer characteristics of water and water-based nanofluids. Our data suggest that the CHF and BHF decrease as heater surface area increases. For concentrations from 0.1 vol% to 2 vol%, the deposition of the particles on the wire allows high heat transfer through inter-agglomerate pores, resulting in a nearly 3-fold increase in burnout heat flux at very low concentrations. The nanoparticle deposition plays a major role through variation in porosity. The CHF enhancement is non-monotonic with respect to concentration. As the concentration is increased, the CHF and BHF decrease prior to increasing again at higher concentrations. Results show a maximum of 270% CHF enhancement for ribbon-type heaters. The surface morphology of the heater was investigated using SEM and EDS analyses, and it was inferred that the 2 vol% concentration deposition coating had higher porosity and rate of deposition compared with 0.2 vol% case. (C) 2012 Elsevier Ltd. All rights reserved.

    Journal Title

    International Communications in Heat and Mass Transfer

    Volume

    41

    Publication Date

    1-1-2013

    Document Type

    Article

    Language

    English

    First Page

    1

    Last Page

    9

    WOS Identifier

    WOS:000315066200001

    ISSN

    0735-1933

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