NUCLEATE POOL BOILING HEAT-TRANSFER IN BINARY-MIXTURES

Experimental studies have been made for heat transfer during nucleate pool boiling on a horizontal platinum wire in nonazeotropic binary mix tures of R12+R113, R134a+R113, R22+R113 and R22+R11 at a pressure from 2 to 8 bar and at a heat flux up to 1.0 x 10(5) W/M2 . The substances employed were chosen such that the components of a given mixture have a large difference in saturation temperatures. A correlation was deri ved by improving Thome's correlation, predicting the heat transfer coe fficients for the mixtures within an accuracy of +/- 25 percent. It is also shown that the correlation can be applicable for mixtures with a small difference in saturation temperatures within an accuracy of +/- 20 percent. The heat transfer coefficients for the mixtures are small er than that for the single components over the entire concentration r ange. The heat transfer coefficients for the mixtures depend on the sy stem pressures and heat fluxes at a lesser extent than that for the si ngle components.