On calculation of heat exchange for condensation in horizontal tubes

Abstract

A method is proposed for determining the intensity of condensation from the value of the equivalent force applied to the condensate film. The asymmetry of film flow along the perimeter of a horizontal tube and the dependence of the characteristic size of the calculation expressions on regime parameters of the condensing flow are demonstrated. Heat exchange devices using condensation within horizontal tubes are found in many branches of industry. Despite this fact, the heat liberation conditions for such devices have not been studied sufficiently. An analysis of available data [i] shows that for one and the same range of condensing flow regime parameters the calculation expressions presented produce qualitative and quantitative divergences in the principles of heat exchange. The most significant divergences occur in calculated heat liberation coefficients in the range of moderate and low motion velocities and with complete condensation of the vapor. The absence of reliable engineering and theoretical computation equations is retarding the wide use of efficient horizontal heat exchange apparatus.