Research On Corrosion Of Dilution Steam Generator In Ethylene Plant

Since the ethylene plant of Lanzhou Petrochemical Company has been put into operation, the dilution steam generator has been frequently leaked.The leakage of dilution steam generator not only reduces the yield of dilution steam, affects the indicators of energy consumption and material consumption, but also the corrosion perforation of heat exchange tubes can make the quench oil leakage, enter the dilution steam system, coking the cracking furnace’s tubes, effecting the operation cycle, seriously, it may also affects the unit’s safe and stable operation. Therefore, it is essential to find out the reason of corrosion leakage of the dilution steam generator, and take appropriate measures to prevent the corrosion leakage,it is the key to ensure the stable operation of dilution steam system in ethylene plant.In this paper, The effect of dilution steam system in ethylene plant and the process flow of dilution steam generator and the structure of equipment are briefly introduced.Then the condition of the leakage fault of the diluted steam generator in Lanzhou Petrochemical Ethylene plant is been described,by communicating with ethylene plant in the same industry,the problems of partial dilution steam system and dilution steam generator are listed,on this basis,we find the reasons for the corrosion of the generator by appearance checking,chemical composition analysing and corrosion morphology detecting.In order to prevent corrosion of the dilution steam generator,According to the process corrosion environment in the production of the dilute steam generator,we do some corrosion simulation test in different phase(gas / liquid), different acid and alkali conditions,we aslo do some research and analysis of the corrosion characteristics of the technological medium,at last,we find ways to reduce the corrosion of the dilution steam generator.After the ethylene plant using the pH advanced control system and taking a series of anti-corrosion measures like optimizing the Injection volume of industrial additives and adding the magnesium block in the heat exchanger,we achieve good result on anti-corrosion of the dilution steam generator.