基于工艺仿真的焦炭塔开工线腐蚀分析与防护

Analysis and Protection for Corrosion in the Line on the Top of Coke Drum based on Process Simulation

以天津石化炼油厂2~#延迟焦化装置焦炭塔顶开工线腐蚀失效案例为研究对象,通过工艺过程仿真计算,研究开工线管道内腐蚀性介质物性组成及相态变化规律,明确开工线管道腐蚀机理主要为NH_4Cl盐结晶沉积垢下腐蚀和湿H_2S腐蚀。通过分析铵盐结晶腐蚀产生的条件,提出产生NH_4Cl结晶的切焦水中临界Cl^-含量。针对开工线系统腐蚀机理,提出增强伴热,加强保温,增设管道温度在线监测系统等腐蚀防护措施。

The corrosion failure case of the line on the top of the coke drum of2#delayed coking unit in Tianjin petrochemical refinery is studied.The research studies physical properties and phase behavior changes of corrosive medium in the line system based on process simulation analysis.The corrosion failure is mainly caused by under deposit corrosion of NH4Cl salts and the corrosion of wet H2S in the system.For the corrosion failure mechanism,corresponding protective measures and optimized schemes are put forward.