Study On Water Carrying Of Diesel Oil In Inclined Pipes Based On Large Eddy Simulation

With the continuous laying of refined oil pipelines,the problem of internal corrosion caused by the accumulated water in pipes has also increased.The accumulated water in the pipe not only affects the efficiency of pipe transportation,but also threatens the transportation safety of the refined oil.This article takes the diesel carrying water flow in inclined pipelines as the research object,and explores the numerical simulation method of simulated diesel carrying water flow.With this method,the law of diesel carrying water is studied.In order to obtain the true phase distribution characteristics and flow patterns of diesel carrying water,the experimental images of water-carrying experiments in inclined pipes based on Froude's similarity criterion were collected.A set of phase-distribution identification and flow pattern recognition methods for oil-water two-phase flow,including grayscale,grayscale adjustment,median filter,and edge detection,have been established.According to this method,the flow patterns of experimental conditions were divided into SW,SW&MI,DW/O&O and VFD W/O.In order to explore a numerical simulation method suitable for studying the flow of diesel-carrying water,the VOF model was coupled with the numerical simulation of Reynolds-averaged method and large eddy simulation method.Comparing the difference between the two simulation results and the real flow,it is considered that the large eddy simulation method can better identify the vortex structure of the diesel water-carrying process than the Reynolds average method,and the simulated results are more consistent with the real flow..Based on the conclusion of the study,a numerical simulation method for simulation of diesel-carrying water flow was established.Finally,using the established numerical simulation method to carry out parametric study of diesel carrying water in inclined pipelines.The influence of parameters such as flow rate,inclination angle and initial water phase content on oil carrying capacity was studied.The study concluded that:(1)The flow instability of the stratified flow between oil and water is related to the shear rate and inclination;(2)The higher the inlet oil speed,the higher the water carrying efficiency of diesel oil.(3)The change of inclination angle changes the flow pattern,and the flow pattern resulting from the change of inclination angle has smooth wavy stratified flow,wavy flow,and dispersed flow.In addition,as the angle increases,the water carrying efficiency first increases and then decreases.(4)The initial water phase content will affect the flow pattern,and the water carrying rate will increase with the increase of the initial water phase content.Through the above studies,a numerical simulation method suitable for simulation of diesel carrying water flow has been established.Based on this method,the critical water-carrying flow rate with different dip angles can be obtained.Through Froude's similarity criterion,it can be returned to the actual project,guiding the actual project...