Abstract:

The hydrogenated type sour water treatment unit of a certain refinery enterprise was completed and put into operation in August 2020, with a design scale of 120 t/h. In December of the same year, it was discovered that there was internal leakage in the E106 tube bundle of the secondary condenser of the side line system, and 15 tubes were blocked before being put back into use. In February of the following year, there was another internal leakage in the tube bundle, and the tube bundle was replaced with an upgraded material of 06Cr19Ni10. During this period, it was found that the outlet pipeline at the bottom of the condenser shell side and the discharge line at the bottom of the downstream knockout tank V107 had significantly reduced thickness, the material was upgraded to 06Cr19Ni10 at an appropriate time. Analysis shown that the main types of corrosion are ammonium thiohydride aqueous solution corrosion and erosion corrosion, especially in the high flow velocity areas on the outer side of the elbow and near the outlet of the condenser shell where have the most severe erosion corrosion. The main reasons for corrosion are that the operating load of the siding system far exceeds the design capacity, the ammonia nitrogen concentration exceeds the design value for a long time, and improper operation. By upgrading materials and optimizing operating loads in a targeted manner, the corrosion situation was significantly alleviated and controlled.

Key words:

摘要：

某炼化企业加氢型酸性水处理装置于2020年8月建成开工投用，设计规模为120 t/h。同年12月发现侧线系统二级冷凝器E106管束内漏，堵管15根后重新投用。次年1月再次发生管束内漏，进行了管束更换，材质升级为06Cr19Ni10。在此期间检测发现，该冷凝器壳程底部出口管线以及下游分液罐V107底部排液线减薄明显，择机将材质升级为06Cr19Ni10。分析发现，腐蚀主要为NH₄HS水溶液腐蚀+冲刷腐蚀，尤其是在弯头外侧和冷凝器壳程出口附近高流速部位，冲刷腐蚀最为严重。腐蚀的主要原因是侧线系统运行负荷远远超出设计能力、氨氮浓度长期超出设计值和操作不当等。最终，通过针对性地升级材质和优化运行负荷，腐蚀情况得到明显缓解和控制。

关键词: 酸性水汽提装置, 侧线系统, 腐蚀, 换热器, 管道, 流速, NH₄HS, 材质