Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

Pool Boiling Heat Transfer from a Horizontal Wire to Aqueous Surfactant Solutions

Get access (open in a dialog) DOI: 10.1615/IHTC10.4770
pages 177-182

Abstrakt

The pool boiling behavior of aqueous surfactant solutions has been investigated under atmospheric pressure conditions. An electrically heated horizontal platinum wire of diameter 0.0254 cm and 15.24 cm in length served both as the heating element in the saturated liquid pool and as the resistance thermometer. Deionized water was the solvent for each solution. Two surfactants, sodium lauryl sulfate (SLS) and polyoxyethylene sorbitan monooleate (Tween-80), were selected for these studies. Three concentrations of each surfactant were studied.
For each solution the steady shear viscosity and the surface tension were measured. These fluids behaved as Newtonian fluids with all relevant transport and thermodynamic properties except surface tension being the same as those of water. The surface tension values of the aqueous surfactant solutions were as much as 26 percent lower than those found for deionized water, with the concentration of the surfactants being the controlling factor. In general, the boiling process did not affect the values of the surface tension or the viscosity of these aqueous surfactant solutions.
The boiling heat transfer coefficients of the SLS solutions were slightly higher than the values found for deionized water alone at heat fluxes below 10 W/cm2. For heat fluxes above 10 W/cm2 , there is no statistical difference between the boiling performance of the SLS solutions and that of deionized water. The boiling performance of the Tween-80 solutions was inferior to the performance found for deionized water at heat fluxes below 20 W/cm2. For heat fluxes above 20 W/cm2 the heat transfer coefficients found for Tween-80 solutions were about the same as the values found for deionized water. In general, the boiling performance of the aqueous surfactant solutions with substantially reduced surface tension did not differ from that found for water alone. These findings call into question the correlation equations of Rohsenow, Nishikawa and Kutateladze, all of which predict substantial increases in heat transfer for the low surface tension solutions.