Heat transfer behavior of silica nanoparticles experiment in pool boiling

    Authors

    D. Milanova;R. Kumar

    Comments

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    Abbreviated Journal Title

    J. Heat Transf.-Trans. ASME

    Keywords

    nanofluids; pool boiling; CHF; surface charge; THERMAL-CONDUCTIVITY; NANOFLUIDS; FLUIDS; WATER; FLUX; Thermodynamics; Engineering, Mechanical

    Abstract

    The heat transfer characteristics of silica (SiO(2)) nanofluids at 0.5 vol % concentration and particle sizes of 10 nm and 20 nm in pool boiling with a suspended heating Nichrome wire have been analyzed. The influence of acidity on heat transfer has been studied. The pH value of the nanosuspensions is important from the point of view that it determines the stability of the particles and their mutual interactions toward the suspended heated wire. When there is no particle deposition on the wire, the nanofluid increases critical heat flux (CHF) by about 50% within the uncertainty limits regardless of pH of the base fluid or particle size. The extent of oxidation on the wire impacts CHF and is influenced by the chemical composition of nanofluids in buffer solutions. The boiling regime is further extended to higher heat flux when there is agglomeration on the wire. This agglomeration allows high heat transfer through interagglomerate pores, resulting in a nearly threefold increase in burnout heat flux. This deposition occurs for the charged 10 nm silica particle. The chemical composition, oxidation, and packing of the particles within the deposition on the wire are shown to be the reasons for the extension of the boiling regime and the net enhancement of the burnout heat flux.

    Journal Title

    Journal of Heat Transfer-Transactions of the Asme

    Volume

    130

    Issue/Number

    4

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    6

    WOS Identifier

    WOS:000255110800002

    ISSN

    0022-1481

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