摘要
目的分析液相流动、颗粒、管道结构参数对固液两相流弯管冲蚀的影响,设计一种弯管防蚀减磨防护方案。方法通过循环管路试验分析流速、颗粒粒径和颗粒形状对弯管冲蚀率的影响,并通过数值模拟探讨渐扩式防护方案对固液两相流在弯管段流场分布的影响。结果采用失重法分析试验结果,在含砂(质量分数2.5%,砂粒直径20~40目)的X80钢管结构下,冲蚀后贴片的质量损失率达到6.85%。经分析,试验贴片表面的主要损伤特征为弯头外拱壁的冲蚀率高于内拱壁,两侧壁面的质量损失率介于内外壁之间。采用数值模拟渐扩管(3∶4、3∶5、1∶2)对冲蚀的影响,在高流速(2.5 m/s)时,扩径比为1∶2渐扩管的冲蚀率下降了约30%,效果最为明显;在流体流速低于0.5 m/s时,粒径为200μm的颗粒沉积增大了弯管外壁的局部磨损。尖角颗粒和球形颗粒对壁面的冲蚀效果不同,模拟的壁面冲击力有明显区别。结论弯管段是典型的三维螺旋流动,在弯管段外拱壁的壁面附近为流动的高压低速区,内拱壁面附近流动为低压高速区。在冲蚀–腐蚀交互的过程中,管道外拱壁的局部损伤主要是因多次受到固体颗粒的冲击而积累的冲刷和磨损作用,内拱壁的损伤机理以腐蚀增重作用更为显著,而固体颗粒受到流体沿管壁方向轴对称的二次流剪切作用,对管道两侧壁面的损伤主要贡献了犁削和磨蚀作用,颗粒形状也影响了壁面损伤机制。防护方案是弯管段采用渐扩段圆管。数值试验表明,在颗粒粒径和流速一定时,采用特定比例的渐扩弯管段降低了流体通过弯管时的流速和湍流强度,能够达到减小冲蚀率的效果。
The work aims to analyze the effects of fluid parameters,sand parameters,and pipeline structure on the erosion of solid-liquid two-phase flow elbows,and design an anti-corrosion and wear-reduction protection scheme for elbows.The effects of flow velocity,particle size and particle shape on the erosion rate of the elbow were analyzed through the circulating pipeline test method,and the effects of the gradual expansion protection scheme on the flow field of the elbow were explored through numerical simulation.According to the test results of the mass loss rate method,under the X80 steel pipe structure with a mass flow rate of 2.5%and a sand diameter of 20-40 mesh,the mass loss rate of the patch after erosion was 6.85%.After analysis,the main damage characteristics of the test patch surface were summarized as:the erosion rate of the outer wall of the elbow was higher than that of the inner wall,and the mass loss rate of the two side walls was between the two.The effects of 3∶4,3∶5 and 1∶2 gradual expansion pipe on erosion were studied by numerical simulation.The erosion rate of 1∶2 gradual expansion pipe decreased by about 30%at a high flow rate of 2.5 m/s,and the effect was the most obvious;When the fluid flow rate was lower than 0.5 m/s,the deposition of particles with a particle size of 200μm increased the local wear of the outer wall of the elbow.Sharp particles and spherical particles had different erosion effects on the wall,and the simulated wall impact was obviously different.The flow in the elbow section is a typical three-dimensional spiral flow.The area near the outer wall of the pipe in the elbow section is a high-pressure and low-velocity area,while the additional flow on the inner side wall is a low-pressure and high-speed area.In the process of erosion-corrosion interaction,the local damage mechanism of the outer wall surface of the pipeline is mainly due to the accumulation of erosion and abrasion caused by repeated impacts of solid particles,and the damage mechanism of the inner wall surfac
作者
白莉
商鹏程
刘强
董祥伟
BAI Li;SHANG Peng-cheng;LIU Qiang;DONG Xiang-wei(China University of Petroleum,Shandong Qingdao 266580,China;CSSC Huangpu Wenchong Shipbuilding Company Limited,Guangzhou 510000,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2022年第10期218-225,292,共9页
Surface Technology
基金
山东省自然科学基金(ZR2021MA039)。
关键词
海底管道
冲蚀
防护方案
弯管
固体颗粒
固液两相流
submarine pipeline
erosion
protection scheme
elbow
solid particles
two phase flow
