Leakage behaviors through small breaks in horizontal gas-liquid two-phase flow pipes

To reveal complex leakage behaviors during gas-liquid two phase flow, leaking experiments were conducted using air and water as the working media. The experimental pipeline had an inner diameter of 32 mm, a break size of 3 mm, and break orientations of 0°, 45°, 90°, 135°, and 180°. The experimental gas superficial velocities ranged from 3.5 m‧s-1 to 25.0 m‧s-1, and the liquid superficial velocity ranged from 0.052 m‧s-1 to 0.397 m‧s-1. The observed flow patterns included wavy flow, slug flow, and annular flow. The results show that the leakage volume of gas and liquid depends on influence zone sizes, which are mainly determined by break location, inlet flow pattern, and gas and liquid superficial velocity. Leakage behavior is approximately the same for 90◦, 135°, and 180° breaks. Under annular flow, the leakage gas volume is the largest and the leakage liquid volume has the widest distribution comparing to the other two flow patterns. The leakage gas volume for slug flow is in the middle. Correlations considering gas-liquid flow rate, pressure difference, and gas quality were derived, which was independent of flow pattern and break location. This correlation can be used for predicting leakage volume of two-phase gas-liquid flow through small breaks. © 2024 Zhejiang University. All rights reserved.