Experimental Study of the Effect of Inclination Angle on the Heat Transfer Characteristics of Steam Condensation in the Vertical Tube

Abstract The purpose of the experiment was to investigate the effect of inclination angle on steam condensation heat transfer characteristics for downward flow in a vertical tube at different mass fluxes. The inlet pressure of saturated steam was 0.2 MPa and the mass fluxes ranged from 20 to 60 kg·m−2·s−1. The experiment was conducted at a range of inclination angles between 0° to 25°. The results showed that with the variation of inclination angle, the flow patterns in the tube at the outlet of the condensate tube mainly showed three kinds of type, namely, annular wavy flow, semi-annular wavy flow and stratified wavy flow. Moreover, the heat transfer coefficient increased with the increase of the inclination angle, and the influence of the inclination angle on the heat transfer coefficient decreased with the increase of the mass fluxes. The effect of the inclination angle on the heat transfer coefficient increased as the vapor quality decreased. Comparing the heat transfer coefficients measured experimentally with the calculated values of the correlation equation of Shah (2016), the results showed that the precision of the predicted values of the relational equation of Shah for the heat transfer coefficients of condensation in the inclined tube was good enough.