Prediction of erosion life of coal water slurry pipeline based on grey prediction model

Solid-liquid two-phase flow is widely appeared in the coal chemical production process, two-phase solid-liquid flow erosion is a particular problem in the pipeline transportation system, and the potential for sudden system failure is extremely high and this has become a major hidden hazard for the safe production and stable operation of coal chemical plants. To reduce the production safety risk and ensure the safe and reliable operation of pipeline system, the study on the prediction of erosion life was a key part of the research on the integrity of coal chemical equipment. Taking a coal-water slurry vaporizer feed pipe of a coal chemical plant in Xinjiang as the research object, ANSYS 2012R1 software is applied to conduct numerical simulation analysis to determine the main location of the bend tube erosion and the erosion thinning in a short period of time, to provide the original sequence for the prediction model, and to establish GM(1, 1) model, unbiased GM(1, 1) model and gray Markov model respectively through gray prediction theory. The prediction of the erosion rate of the pipe bend was completed, and the service life and maintenance cycle of the pipe were derived by combining the “Assessment of corroded steel pipelines”. This showed that the erosion thinning was mainly concentrated in the axial direction of the bend about 70 degrees, and the maximum position of the erosion thinning did not move with the change of time under the same process conditions. The unbiased GM(1, 1) model and the Gray Markov model had significant advantages in medium and long-term prediction, and the Gray Markov model was more suitable for long-term prediction work. The service life of the coal-water slurry vaporizer feed transfer bend involved was about 570 days, and the amount of erosion thinning increased significantly after the bend was put into service for 450 days, which required regular monitoring and preventive maintenance of the key parts of the bend. © 2023 Chemical Industry Press. All rights reserved.