Research On The Control System Of Oil Extraction Joint Station Based On PLC

Because of the corrosion by internal medium at work, the wall thickness of the storage tank’s shell will continue thinning and certain local corrosion defects may occur, which will weaken the strength of the tank. What’s more, this case will pose grave threats to people’s life and property safety, also to the environment our live.In order to study the stress state of the working tank which was corroded, this paper based to GB150 designed a liquid ammonia tank with a capacity of 4.5 cubic meters firstly. Then for analyzing the stress distribution of the integral and local corrosion and assessing the security of the tank, the text set up the whole and local finite element model which are in different corrosion condition. According to this results of analysis the paper predicted remaining life of the tank. There has five parts in the contents of the analysis and they are following. The first part is the stress analysis and stress evaluation of the tank’s global structural which hasn’t been corroded. The second describes variation distribution of stress and displacement of the whole structure which is subjected to uniform corrosion and the security assessment of the tank like the former. In the third part, the content is the analysis and stress evaluation of the tank’s opening and nozzle structure which hasn’t been corroded while in the fourth part that is subjected to ammonia uniform corrosion. At last, the paper built storage tank structure with two corrosion defects and analyzed its variation distribution of stress and displacement in different defects size.In this article, finite element analysis software-ANSYS-is used to establish model, impose work load and make simulation analysis. The follow is the main conclusion obtained by summary on data and graphics. The maximum stress of the tank which is in different corrosion condition appeared on the webs of the support, while the head in the bottom has more complex stress distribution. The maximum stress in opening and nozzle structure occurred in the inner wall surface of nozzle. The linearization analysis of the dangerous section shows that the tank with uniform corrosion run safely during the design life. So does the structure of opening and nozzle region. The weakening effect of corrosion pit at head in the bottom of storage tank on the strength of the tank increases with the increasing depth of the defect.