常减压塔顶空冷器出口集合管段腐蚀失效机制研究  

Study on corrosion failure mechanism of the collection pipeline at the outlet of the air cooler on the top of atmospheric-vacuum tower

作　　者：张建文[1] 赵红烨 王佳录 李彦 刘正伟 ZHANG Jianwen;ZHAO Hongye;WANG Jialu;LI Yan;LIU Zhengwei(Beijing University of Chemical Technology,Beijing 100029,China;Shanghai Petrochemical Co.,Ltd.,Shanghai 200042,China)

机构地区：[1]北京化工大学,北京100029 [2]上海石化有限责任公司,上海200042

出　　处：《能源化工》2020年第1期54-59,共6页Energy Chemical Industry

基　　金：国家科技支撑计划(2015BAK39B00)。

摘　　要：针对某石化厂常减压装置塔顶空冷器出口管道至集合处管段多次出现穿孔的问题,研究了腐蚀管段内部周向与轴向厚度的分布情况,同时采用X射线衍射、扫描电镜、X射线衍射能谱仪对管段腐蚀试样进行了检测,分析管段腐蚀的原因。结果表明:管道腐蚀是由H2S腐蚀、铵盐结晶垢下腐蚀的化学反应与冲刷腐蚀协同作用造成的。集合管段入口处腐蚀产物在管壁上的附着比较疏松,容易被流体冲刷,对管壁的保护作用较弱,在冲刷腐蚀协同的作用下,腐蚀较为严重;沿着流动方向,管壁上的腐蚀产物对壁面的吸附逐渐增强,腐蚀逐渐减弱。In order to solve the problems of many times perforations in the section from the outlet pipe of the overhead air cooler of the atmospheric and vacuum unit to the collection pipeline of a petrochemical plant, the distribution of the circumferential and axial thickness of the corroding pipeline section is studied. Meanwhile,X-ray diffraction, scanning electron microscope and EDS are used to detect the corrosion samples of the pipeline section, and the causes of the corrosion are analyzed. The results show that the corrosion of pipeline is caused by synergistic effect of the chemical reaction of H2S corrosion and ammonium salt crystal under-deposit corrosion and the erosion corrosion. The corrosion products at the inlet of the collection pipeline is loosely attached to the pipe wall, which is easy to be washed out by the fluid and has weak protective effect on the pipe wall. Under the synergistic effect of erosion corrosion, the corrosion is more serious. Along the flow direction, the adsorption of corrosion products on the pipe wall to the wall is gradually enhanced, and the corrosion is gradually weakened.

关 键 词：常减压塔 空冷器 集合管段 腐蚀 机制 

分 类 号：TQ051.5[化学工程]