Effect of Inclination on Hold-Up and Frictional Pressure Drop in Inclined Annular Two-Phase Up-Flow.

Abstract

Gas-liquid two-phase flow in an inclined tube is frequently encountered in various kinds of pipelines transporting thermal energy using steam and water as a thermal medium. However, fundamental experimental data on annular two-phase flow in an inclined pipeline are very few compared with those on two-phase flow in a vertical pipeline. In this paper, experimental data on hold-up, frictional pressure drop of an annular two-phase flow and flow pattern in an inclined tube of 26 mm diameter are presented and the effects of the inclination angle are examined. The inclination angles measured from the horizontal were 0, 15, 30, 45° and 60°. Superficial velocities of air and water ranged from 10 m/s to 50 m/s and from 0.006 m/s to 0.20 m/s, respectively. As a result, it was clarified that the transition jG from froth to annular flow decreases as the inclination angle increases, the L-M curve for frictional pressure drop can be applied to the case of large inclination angle, the distribution of probability density function has exhibits a unique shape for each flow pattern independent of the inclination angle, and the relation between two-phase friction multiplier and hold-up varies with the inclination angle.