A Universal Correlation Development for Film-Wise Condensation in the Presence of Non-Condensable Gases on Vertical Walls under Turbulent Free Convection

Accurate prediction of steam condensation in the presence of non-condensable gases is essential for accident analysis in nuclear reactor containments. This study uses the steam-air mixture to illustrate the effect of the mixture's compressibility in analyzing steam condensation. Then, a consolidated database of steam condensation on vertical walls was established, and seven typical empirical and semi-empirical correlations were evaluated. Based on heat and mass transfer analogy and curve fitting, a new universal correlation for predicting steam condensation on vertical walls in the presence of non-condensable gases, including binary and ternary mixtures, under turbulent free convection is established, and this correlation can well handle the transition from binary to ternary mixtures using the same formula. More than 90% of predicted results compared with 1027 data points are within the +/- 25% error band, and the mean absolute error is 10.6%. The similarity of helium and hydrogen in analyzing steam condensation is discussed.