Establishing And Application Of Corrosion Monitoring System In 1Mt/a Ethylene Unit

The corrosion medium of raw materials and reaction product of Ethylene unit in the process of production,such as sulfur and acid,not only can cause corrosion of ethylene plant itself,but also will cause corrosion of varying degrees to the downstream unit,which seriously affect unit operation safely.In the production practice,usually after corrosion problems occurring,the protection measures were taken to solve the problem,which was passive.And corrosion damage may cause equipment corrosion failure,leading to unit stop,or cause the production safety accidents such as fire,explosion.Therefore,in order to predict the corrosion trend of the unit timely,and prevent the corrosion further development effectively,a set of timely and accurately corrosion monitoring system was established from point of view of the corrosion monitoring technology integration and engineering application.In this paper,the main conclusions are as follows:1.The corrosion harm of the unit was evaluated from corrosion parts of in the ethylene unit,corrosion parts of the same domestic ethylene unit,corrosive medium analysis,and the corrosion analysis of the RBI,HAZOP,and LEC,the results prove that the corrosion parts mainly concentrated in ethylene section,cooling section,compression section,lkaline cleaning section,and gasoline hydrogenation section.2.The damage degree of corrosive medium and its flow were analyzed on the technology materials in ethylene unit,and flow chart of the corrosive section was drawn up on ethylene unit.3.Acording to the technology characteristic,corrosion features of technology materials,and applicable characteristic of corrosion monitoring technology and installation requirements,the monitoring scheme of ethylene unit were drawn up,such as corrosion medium monitoring scheme,corrosion piece monitoring scheme,on-line corrosion probe monitoring scheme,ultrasonic thickness monitoring scheme,corrosion examinition scheme,etc.In the end,the corrosion monitoring system was formed.4.The practical result proves that the corrosion monitoring system obtained the good effect of monitoring,because the corrosion trend or corrosion of equipment and pipeline of some system were monitored successively,such as technology water system,dilution steam system,compressor system,ect.5.In order to save a mount of corrosion monitoring data,a software was developed on the basis of web mode,which named corrosion data management system of ethylene project in Du Shanzi petrochemical industry.This software achieve the goal of type-in,browse,query,generating charts,abnormal alarm,data verifying,etc.