ABSTRACT
The condensation inside tubes is generally classified according to the tube orientation: condensation inside vertical tube and inside horizontal tube. In a vertical tube, an annular condensate film forms on the tube surface, whereas in a horizontal tube, the flow direction is perpendicular to the gravity and makes the two-phase flow of vapor and condensate more complicated. Cavallini and Zecchin presented a dimensionless correlation for forced convective condensation of pure saturated vapor inside tubes based on a simple hydrodynamic model of the annular flow pattern and on the momentum and heat transfer analogy. During the condensation of zeotropic binary vapor mixture in tubes, the compositions as well as the temperatures in the vapor and liquid phases change along the length of the tube. The mass fraction of more volatile component in the vapor core increases, and the temperature of the bulk vapor mixture decreases along the flow direction.
