摘要
以某石化重整装置开裂碱洗塔为研究对象,分析氢气-碱液两相耦合腐蚀机理和碱洗塔失效原因。采用CFD技术,仿真模拟碱洗塔内部氢气-碱液流动流场,计算两相介质速度和动压力分布,并结合失效材料的化学成分、拉伸力学性能试验及塔内壁表面腐蚀产物分析,确定碱洗塔失效的原因是流动加速腐蚀,即潮湿含HCl的氢气与碱洗塔壁面接触,由于碱液流动存在不均衡性,HCl未与碱液中和而是与壁面发生腐蚀反应。同时,在高速氢气的作用下,腐蚀产物膜发生剥落,从而加速塔体壁面的减薄,最终在内压作用下发生开裂。该研究结果可为类似工艺装置与工况特点的在役承压设备避免相似损伤失效模式提供参考。
By using the cracked caustic wash tower of a petrochemical reforming unit as the research object,the corrosion mechanism of hydrogen-alkali liquid two-phase coupling and the failure causes of the caustic wash tower.Using CFD technology,the flow field of hydrogen-alkali liquid inside the caustic wash tower was simulated.The velocity and dynamic pressure distribution of the two-phase medium were calculated.Based on the analysis of the chemical composition,tensile mechanical properties,and corrosion products on the inner wall surface of the failed material,it is determined that the cause for the failure of the caustic wash tower is flow accelerated corrosion,that is,the wet hydrogen containing HCl comes into contact with the wall surface of the caustic wash tower.Due to the uneven flow of alkali solution,HCl did not neutralize the alkaline solution but underwent a corrosion reaction with the wall material.At the same time,under the action of high-speed hydrogen gas,the corrosion product film peels off,accelerating the thinning of the tower wall and ultimately cracking under internal pressure.The research results provide a reference for in-service pressure equipment with similar process equipment and operating conditions to avoid similar damage failure modes.
作者
蒋良雄
JIANG Liangxiong(Sinopec Yangzi Petrochemical Co.,Ltd.,Nanjing 210048,China)
出处
《压力容器》
北大核心
2023年第4期67-73,86,共8页
Pressure Vessel Technology
基金
国家自然科学基金项目(U1909216,51876194,52176048)。
关键词
碱洗塔
氢气
腐蚀
冲刷
流场
alkali washing tower
hydrogen
corrosion
scouring
flow field
