Numerical Simulation Research Of Erosion Wear For Coal Water Slurry Pipeline Transportation

In the process of preparation and transportation of coal water slurry,with high solid concentration and complicated mediurn components,and always works under severe operating conditions as high temperature and high pressure,coal water slurry has complex flow characteristics.Coal water slurry pipeline transportation is a typical solid-liquid two-phase flow process,pulverized coal particles flow with the coal slurry process will erosion wear the pipeline and cause great potential hazard to pipeline operation safety,especially for those typical pipes fittings erosion wear failure is more likely to occur,such as elbow,reducer,tee pipe,etc.In this paper,major study objects are 90° elbows,reducers and tee pipes in pipeline from tank to gasifier for coal water slurry exported by booster pump.The three-dimensional numerical simulation is used for the study of 90° elbow,reducer and tee pipes by computational fluid dynamics(CFD)numerical simulation methods.Firstly,the theory of erosion wear of coal water slurry is introduced detailed in the character and classification of coal water slurry,erosion wear mechanism and erosion influencing factors.Secondly,the disperse phase simulation theory of erosion is studied,and the basic control equations are established in sequence,the standard k-? turbulence model and the disperse phase random orbit model is chosed to study the particle trajectory,and the corrosion and deposition model as the erosion wear rate model.Standard wall surface function method and the bounce-back recovery and the rebound recovery equation coefficient are selected as the wall surface treatment and particle collision wall after particle collision wall,select the QUICK discrete format and pressure-based solver as a control equation discretization and solution method.Thirdly,according to the actual plant data,successively build the geometric model,mesh model grid,set the boundary condition,solve operation and simulation operation,and verify the validity of the grid and the model.Calculated by Fluent and simulate the maximum erosion rate and the distribution of erosion wear of coal-water slurry pipeline tunder different work conditions in this paper.The erosion wear law of coal water slurry pipeline is analyzed and studied,and establishes the prediction method of erosion wear of coal water slurry pipeline.Through this method analysis and research the influences of various factors(pipe diameter,bending diameter ratio,bending angle,diameter of the coal particles,density of the coal particles,mass flow of the coal particles,inlet velocity)on the erosion wear.And put forward the reasonable precautionary measures of pipe erosion wear,which provides the theoretical basis for pipe design,process calculation and wall thickness monitoring of pipeline system,and provides some theoretical guidance for practical application of engineering.