Study On Wear Rules And Replacement Strategy Of Dredging Pipelines

In industrial production,one of the most common material loss is abrasion.In recent years,with the domestic and international port construction,channel upgrading and related development about river and lake,dredging engineering amount rapidly grows in a high speed.The most typical and representative projects in this area includes,China's South China Sea "blowing sand fill reef" project,Caofeidian port construction project,Yangtze River golden waterway repairs,Reclamation works of Dalian Zhoushuizi International Airport.Dredger has been widely applied in the dredging project with three basic types of work,such as cutter digging,mud pump pumping and pipeline transportation.One of the most significant process of the dredger work is pipeline mud transportation.A common reason for pipeline disable is abrasion of pipeline.Thus,it directly brings negative effects about operation of the dredger safely and efficiently,which finally decreases economic benefits.Once the pipeline is damaged,mud leakage can lead to pollution to the environment.Therefore,the study of pipeline-abrasion law,to explore the pipeline replacement strategy,to ensure the safe and reliable operation of dredger is of great significance.Based on the project commissioned by the Yangtze River Waterway Bureau,this paper aims to predict the distribution law and characteristics of erosion and erosion under the erosion condition by numerical simulation,and compare the actual ship data and put forward the pipeline maintenance and replacement strategy.The main research contents are as follows:(1)First of all,through the analysis of the law of motion in the solid-liquid two-phase flow,the mechanism of pipeline abrasion is analyzed,and then the mathematical model of continuous phase model,turbulence kinetic model and erosion wear calculation is established.(2)Model and mesh the horizontal straight pipe and 90° elbow pipe by solidworks and ICEM.Then,the parameters of the study and the boundary conditions were selected.The erosion and abrasion analysis is carried out by Fluent.From the water velocity,the slurry concentration,Size and erosion angle of the four factors affecting the pipeline under the pipeline slurry wear changes.The conclusion is that the dredger pipe wear is generally concentrated in the middle and lower part of the pipeline,in which the lower part is the most serious wear and tear.The increase of slurry flow rate,slurry concentration and particle size will increase the erosion wear.(3)According to the screening of the actual ship abrasion data,the rationality and correctness of the simulation experiment is verified.The conclusion is that the slurry concentration,velocity and size have important influence on the wear of the pipeline.Furthermore,The prediction method of pipe erosion and wear is further proposed,which predicts the erosion rate of pipeline and puts forward some reasonable suggestions on the correct strategy of pipeline replacement.