Conference Year



Pressure Drop of Steam, Air Cooled Condenser, Inclination, Flattened Tube


This paper presents the experimental study of the inclination effect on condensation pressure drop in a large-scale flattened tube used in an Air-Cooled Condenser (ACC) for steam. Slightly-superheated steam with mass flux of 6.8 kg m-2 s-1 was condensed inside a 10.7 m long, flattened half-tube with inclination angle varied from horizontal to 13.2Ëš. A uniform velocity profile of 2.03 ± 0.12 m s-1 was imposed on the air side to extract heat from the steam. Initial two-phase pressure drop measurements and flow visualization showed a reduction of pressure drop due to improvement in the gravity-assisted drainage of condensate inside the tube, although improvement was only seen at an early stage of inclination. To create a visualization window, the tube was cut in half, and thus a model that accounts for the differences in tube material and size between the real, full, flattened condenser tube and test tube was developed and validated in the single-phase flow scenario. This model enables the prediction of pressure drop under different inclination configurations in the actual ACC in power plants by using the experimental results obtained in this study. Heat transfer results are presented in a companion paper.Â