CRITICAL HEAT FLUX OF BINARY MIXTURES IN POOL BOILING

摘要

Critical heat flux (CHF) of five binary mixtures in pool boiling was measured with a horizontal platinum wire, 0.5mm in diameter, over the whole concentration range of the mixtures including their pure components. Test mixtures were methanol/water, ethanol/water, methanol/ethanol, ethanol/n-butanol, and methanol/benzene, each in the saturated state at atmospheric pressure. A total of 250 CHF data were obtained at the 53 concentrations of the five mixtures. Compared with CHF for a hypothetical pure fluid with equivalent properties as the mixtures, the experimented two aqueous mixtures reveal significant increases of CHF, while the other three organic mixtures show much the same level of CHF. Existing correlations for CHF were applied to the present results, but they were found of limited use. In correlating the data, a dimensionless Marangoni number was introduced to obtain an empirical correlation of CHF.