Transient heat transfer during steam film condensation on a horizontal tube

The results of experimental studies of heat transfer that takes place under conditions of film condensation of the steam of Refrigerant-12 in a horizontal tube when the saturation temperature varies in time in the condenser are discussed. The rate of change of the heat-transfer coefficient was found to correspond to calculations made within the framework of the quasi-steady-state approximation according to Nusselt theory. It was proportional to the absolute value of the heat-transfer coefficient, to the rate of change of the saturation temperature, and inversely proportional to the temperature head.