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

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.

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