Abstract: The estimation method of total mole of gas phase in front of high pressure heat exchanger and the calculation formula of crystallization temperature of ammonium chloride are given. The laboratory corrosion evaluation of ammonium chloride solution and its corrosion under scale is carried out. The effects of temperature, concentration and flow rate on the corrosion of ammonium chloride are studied. The countermeasures of ammonium chloride deposition in high-pressure heat exchanger of hydrogenation reaction effluent system are put forward: the engineering design concept should be changed from standard based design to risk-based design, and various influencing factors should be fully considered. According to the calculation results of ammonium chloride crystallization temperature, the deposition position of ammonium chloride is controlled. The selection principle and operation precautions of intermittent water injection and continuous water injection are described. For intermittent water injection, monitoring and operation scheme should be formulated before operation to avoid potential corrosion risk; For continuous water injection, 15%~25% liquid water must be kept at the injection point, and the nozzle or static mixer must be installed to ensure the washing effect. 825 alloy is recommended to improve the reliability of the equipment.

Key words: reaction effluent, high pressure heat exchanger, ammonium chloride, crystallization temperature, corrosion, water injection

摘要： 给出了加氢反应流出物系统高压换热器气相总摩尔数估算方法及氯化铵结晶温度的计算公式;对氯化铵溶液及其垢下腐蚀进行了实验室腐蚀评价,分析了温度、浓度、流速等对氯化铵腐蚀的影响。提出了加氢反应流出物系统高压换热器氯化铵沉积的对策:工程设计理念应由基于标准规范的设计向基于标准规范和风险防控的设计转变,需充分考虑各种影响因素;根据氯化铵结晶温度的计算结果,控制氯化铵沉积部位。阐述了间断注水和连续注水的选择原则和操作注意事项:对于间断注水,应制定好监测和操作方案后再实施操作,避免潜在的腐蚀风险;对于连续注水必须保证注入点存在15%～25%的液态水,同时安装喷头或静态混合器,保证洗涤效果。选材方面推荐选用825合金,大幅度提高设备可靠性。

关键词: 反应流出物, 高压换热器, 氯化铵, 结晶温度, 腐蚀, 注水