Experimental and computational investigation of vertical upflow condensation in a circular tube

Abstract

This study explores the condensation of FC-72 in vertical upflow both experimentally and computationally. An axisymmetric 2-D computational model is used to predict variations of void fraction, condensation heat transfer coefficient, wall temperature and temperature profile across the liquid film. The computed results are shown to effectively capture the observed complex flow characteristics during flooding and climbing film conditions, including the annular film’s interfacial waviness, formation of liquid ligaments along the film’s interface, and breakup of liquid masses from these ligaments that are either re-deposited onto the film or entrained in the vapor core before moving towards the centerline. The model also shows good agreement with measured spatially averaged condensation heat transfer coefficients and wall temperatures. The predicted temperature profiles across the flow area successfully capture an appreciable temperature gradient at the liquid–vapor interface and saturation temperature in the vapor core.