Prediction of two-phase flow boiling heat transfer coefficient of refrigerants in minichannel multiport tubes.

Abstract

In this study, we demonstrate the prediction method for two-phase flow boiling heat transfer coefficient of R410A inside various minichannel multiport tubes. The experimental data were conducted in four tube types with the hydraulic diameters of 0.96 mm, 1.07 mm, 1.14 mm and 1.16 mm, and the aspect ratio from 1.6 to 2.5. The data were collected under the heat fluxes of 3 and 6 kW/m2, the mass flux ranging from 50 to 500 kg/m-2 s-1, the vapor quality up to 1.0 and the saturation temperature of 6 oC. The effect of the heat flux, mass flux, vapor quality and the geometry on heat transfer coefficient are analyzed. The comparison with several heat transfer coefficient correlations was also established. Finally, a new heat transfer coefficient correlation was proposed including the effect of aspect ratio. The validation with present data and the data in open literature shows a good prediction of new correlation.