Heat transfer and flow modes of phases in laminar film vapour condensation inside a horizontal tube

Abstract

By using the gradient method for heat transfer investigation, local heat transfer coefficients are determined for laminar film vapour condensation inside a horizontal tube. A study is made of the effect of vapour velocity, condensate inflow, and transverse mass flux on the intensity of the process. The occurrence of a pronounced asymmetry in the local heat transfer coefficients around the tube perimeter is noted, the decrease of which is promoted by an increase in vapour velocity and local heat flux. The flow modes of phases in the case of incomplete vapour condensation in a tube are identified ; the need to take into account the condensate film thickness and the transverse mass flux effect when constructing the map of the modes is noted. A correlation is suggested to calculate local and mean-integral heat transfer coefficients for laminar film condensation.