Numerical simulation and test on vortex drainage of hilly-terrain wet gas pipelines

In order to solve the safety issues caused by ground occupation of pipelines with corrosion defects, a new type of vortex tool was designed and manufactured in order to remove the liquid loading in hilly-terrain wet gas pipelines. The effects of the inlet conditions of different gas and liquid superficial velocities on the drainage effectiveness of the vortex tool were analyzed by means of Fluent numerical simulation and test, and the working efficiency of the vortex tool was evaluated. It is shown that after the vortex tool is installed, the liquid backflow and bottom liquid loading in the up-dip pipe is relieved to some extent, annular flow is maintained in the up-dip pipe and the liquid holdup is reduced. The drainage and depressurization capacity of the vortex tool depends on the gas and liquid superficial velocity and the pipe inclination angle. When the inclination angle is constant, the drainage and depressurization capacity of the vortex tool increases with the increase of gas superficial velocity. When the inlet condition of gas and liquid superficial velocity is constant, the smaller the pipe inclination angle is (0°-45°), the better the drainage and depressurization efficiency of the vortex tool is. The research results provide theory basis for guiding the site application of vortex drainage technology.