基于FLUENT天然气集输管道直角弯管磨损分析

Wear Analysis at Right Angle Elbow of Nature Gas Gathering and Transportation Pipeline Based on Fluent

应用Fluent软件对直角弯管磨损情况进行数值模拟,研究天然气集输过程中有浮升力和无浮升力条件下不同颗粒直径、不同气流流速条件对弯管磨损的影响,研究结果表明:无浮升力和有浮升力条件下,随着粒径增大,弯管壁面的1.5 s累计最大冲蚀量先减小后逐渐增大,粒径小于50μm的微小颗粒对管壁的冲蚀磨损程度较小。有浮升力条件下,管道壁面的1.5 s累计冲蚀量有所增大,这是由于颗粒在浮升力作用下更多地碰撞弯管壁面。无浮升力和有浮升力条件下,随着粒径增大,弯管壁面的1.5s累计最大沉积量先快速下降而后缓慢增加。有浮升力的条件下,颗粒运动对壁面的沉积效应有所缓解,随着粒径的不断增大,浮升力对管壁的沉积影响逐渐变小。较小粒径的颗粒受浮升力影响在管道沉积方面表现更为敏感。无浮升力和有浮升力条件下,随着气流入口流速的不断增大,弯管壁面的1.5 s累计最大冲蚀量逐渐增大。有浮升力条件下,当入口流速增大时,增大的浮升力导致颗粒跳跃增多,浮升力作用增强了颗粒对弯管壁面的冲蚀破坏。无浮升力和有浮升力条件下,随着气流入口流速的不断增大,弯管壁面的1.5 s累计最大沉积量呈现先减小后逐渐增大的趋势。有浮升力条件下,入口流速增大时,边界层内速度梯度使颗粒旋转而产生更大的浮升力,致使颗粒的沉积量减少。但随着入口流速的继续增大,边界层厚度逐渐变薄,,浮升力的影响作用减小,颗粒沉积量增大。合理控制入口流速能够有效减少管道磨损。

Fluent software is used to simulate the wear of right angle elbow,and the effects of different particle sizes and different airflow velocities on the elbow wear during the process of natural gas gathering and transportation under the conditions of buoyancy lift and no buoyancy lift are studied.The results show that under the conditions of no buoyancy lift and buoyancy lift,with the increase of particle size,the 1.5 s cumulative maximum erosion on elbow wall first decreases and then gradually increases,and the erosion wear degree of small particles with a particle size less than 50μm on the pipe wall is small.Under the condition of buoyancy lift,the 1.5 S cumulative erosion of the pipe wall increases,which is due to particles collide with the elbow wall more under the action of buoyancy lift.Under the condition of no buoyancy lift and buoyancy lift,with the increase of particle size,the 1.5 s cumulative maximum deposition on the elbow wall first decreases rapidly and then increases slowly.Under the condition of buoyancy lift,the effect of particle movement on wall deposition is alleviated,and with the continuous increase of particle size,the effect of buoyancy lift on the deposition of pipe wall gradually becomes smaller.The smaller size particles are more sensitive to pipeline deposition due to buoyancy lift.Under the condition of no buoyancy lift and buoyancy lift,with the continuous increase of the air inlet velocity,the 1.5 s cumulative maximum erosion on elbow wall gradually increases.Under the condition of buoyancy lift,when the inlet velocity increases,the increased buoyancy lift leads to the particle to jump more,and the effect of buoyancy lift enhances the erosion damage of particles to the elbow wall.Under the conditions of no buoyancy lift and buoyancy lift,with the continuous increase of the air inlet flow velocity,the 1.5 s cumulative maximum deposition on the elbow wall shows a trend of first decreasing and then gradually increasing.U nder the condition of buoyancy lift,when the inlet velocity increases,the velocity gradient in the boundary layer will cause the particles to rotate and generate greater buoyancy lift,resulting a decrease of the amount of particle deposited.However,with the continuous increase of inlet velocity,the thickness of boundary layer gradually becomes thinner,the effct of buoyancy lift decreases and the amount of particle deposition increases.Reasonable control of inlet velocity can effectively reduce pipeline wear.