PIV Experimental Research and Numerical Simulation of the Pigging Process

The initial running speed of the pig during gas–liquid two-phase pipeline pigging can significantly influence the velocities of both gas and liquid phases within the pipeline. However, due to the complexity and limited understanding of these velocity variations, developing an effective operational plan for pigging becomes challenging. To enhance pigging efficiency and effectively seal the pig, it is crucial to monitor the velocity variations in the gas–liquid phase within the pipeline. In this study, an experimental platform was established to facilitate precise observation of these variations. Particle image velocimetry (PIV) technology was employed for a comprehensive understanding of gas–liquid two-phase velocities during pig operation in the pipeline. The experimental results demonstrated that increasing both the velocity and the initial liquid level height of the pig resulted in a corresponding augmentation of velocity fluctuation range. Specifically, at a holdup rate of 30%, there was a 10% reduction in the maximum liquid-phase velocity, while at a holdup rate of 25%, this reduction amounted to 16% compared to the pigging velocity.