The Design And Research Of Chemical Industry Liquid-level Supervisory System

In recent years,our country petrochemical industry enterprise's automation and informationization level,regardless of in the equipment,the technical level,the function and the scale has larger development,Measurement and control devices continuously updates.And several thousands of DCS,PLC,PC and FCS have become the main control scheme in the large and middle scale petroleum and the chemical enterprise. The applications of these installments enable the corresponding production information integrated in the workshop,even in the factory level.The application of Field bus Control System is still in its infancy,and has made progress.However,the domestic investigation reveals that,the automatic management level of the chemical tank farm is generally low.It is urgent to transfer and update the chemical tank farm supervisory system.Applying DCS system to the oil tank farm supervisory system has many problems.The development of the redundant technology has further enhanced the system reliability.The appearance of new remote I/O module brings the hope to solve the difficult problem on the supervisory system's hardware structure.However,this product just comes out,and we lack the actual application experience which might profit form.Therefore,how to design a good supervisory system which is suit for the tank farm,advanced,high-efficient,multiple functional,becomes more and more urgent.And domestic and foreign engineers and technicians are committed to resolving this issue at present.This article starts from the research of field bus.Then it analyzes the tank farm's characteristic and intrinsic-safe and explosion-proof as well as the security standard. By comparising several schemes,wo choose fieldbus control schemeswhich takes Siemens S7-400HPLC as hypogyny computer.the article studies and designs the PLC redundant network including the data gathering system based on the remote distributed I/O.the same time we gather the liquid-level,temperature,flux,pressure etc parameters of tank farm and utilize Siemens Step7 V5.3 software of upper computers control these four main parameters Inaddition,the article researches Supervisory system configuration with the domestic popular configuration and software.we adopt Industry Ethernet to communicate upper PC and hypogyny PLC.we adopt PROFIBUS fieldbus to communicate hypogyny PLC and scene.According with testing result of system,various guild line all attain prearrange design demand and functions,which afford convenience for chemical industry liquidlevel supervisory control system's control and manage.