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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

ESTIMATION OF LOCAL CONCENTRATIONS AND VISUALIZATION OF BOILING BEHAVIORS AT HIGH HEAT FLUXES IN SATURATED POOL BOILING OF 2-PROPANOL/WATER MIXTURES

Get access (open in a dialog) DOI: 10.1615/IHTC16.bae.022954
pages 1161-1168

要約

To examine the mechanism of CHF enhancement with binary mixtures, this paper measured local temperatures close to a heating surface at high heat fluxes in pool boiling of a 3 mol% 2-propanol/water mixture on an upward-facing surface, and determined the local concentration of 2-propanol based on the assumption that low peak values in temperature fluctuations correspond to local saturation temperatures of the mixture. The estimated concentration of 2-propanol decreases steeply toward the heating surface. The boiling behaviors of the 3 mol% 2-propanol/water mixture were observed from the back of a transparent surface using a total reflection technique. It was found that the boiling behaviors beneath vapor masses at high heat fluxes are quite different for water and for the mixture. For water boiling, dry areas spread widely across the heating surface, however with the boiling of the 2-propanol/water mixture, dry areas are localized in isolated tiny spots and repeat cycles of generation and disappearance with very high frequency.