Research And Design Of Claus Sulfur Recovery Control System

Environment has been deteriorated with the rapid development of economy and the acceleration of industrialization in China,which leaded energy consumption increased dramatically.This task of achieving sustainable development to achieve efficiently use of energy and reduce pollution extending in all aspects of industrial production.Recently,the sulfur reclaiming section has become an important environmental protection process in industrial production because of the development of numerous greatly natural gas resources in the world.Moreover,the Claus sulfur reclaiming process is the mainstream process in industrial sulfur reclaiming.The automatic control system has been optimized by Claus to reclaim sulfur,improve the level and stability of system automation,ensure the safe operation of the system,increase the sulfur reclaiming rate,and reduce the emission of polluting gases,which is important for social and environmental.The research backdrop in this paper had been ascertained.It is a sulfur in natural gas reclaiming,which based on the key of Claus process analyzing control objectives of the automatic control of sulfur reclaiming and designed a set of automatic control strategy in Jingbian County,Shaanxi Province,China.It was achieved by the Siemens S7-400 PLC control system finally.The main researching work in this paper as follows:(1)Analysis of Factors Affecting Sulfur RecoveryBy analyzing the working principle,process of technical and control index of the three-stage Claus sulfur reclaimed ratio,we were researched the main factors influencing the sulfur recovery rate are: acid gas flow rate,H2S/SO2 ratio,main combustion chamber temperature,airspeed,acid gas components,etc.Among them,acid gas flow,wind/gas ratio and main combustion chamber temperature are the key to the control of Claus sulfur reclaimed.(2)Mathematical model of sulfur recovery processAnalyzed the mechanism of the controlled object is in depth,used a comprehensive of mechanism and experimental testing methods,was established for sulphur reclaiming controlled,which including the acid gas flow controlsystem model,the main combustion temperature control system model,and the windwithgas ratio model.The mathematical model of the control system lays a theoretical foundation for the design of the controller after the sequence.(3)Design and Simulation of Control Scheme for Sulfur Recovery ProcessIn order to stabilize the acid gas flow in the Claus sulfur recovery process,We had designed control scheme to solve the problem of an acid gas flow-pressure cascade for the influence of frequent fluctuations of the acid gas supply pressure on the amount of acid gas entering the main combustion chamber;The problem of the frequent influence of the H2 S volume in the main combustion rear part is to design a temperature-flow cascade control scheme for the main combustion chamber,and We had designed a fuzzy controller that is designed to replace the manual automatic adjustment of the acid gas flow ratio coefficient at the rear of the main combustion chamber to adapt to the working conditions.In order to obtain a good H2S/SO2 ratio,We had designed a ratio of wind/gas cascade control scheme was designed.According to the object parameter time-varying problem,We had designed the fuzzy controller that was designed to automatically adjust the parameters of each major PID controller to obtain good control,Performance and simulation of each controller.(4)Realization of Kraus Sulfur reclaiming Automatic Control SystemI/O point statistics,hardware configuration,control cabinet design,network construction,and HMI interface developed besmenting Siemens Step7+Wincc is a software development platform in this project,which integrated MATLAB software and OPC communication technology to realize the application of control algorithms.As rusult,Claus Sulfur Reclaiming DCS Control System had been Developed in this thesis.The natural gas sulfur reclaiming of automatic control system designing section that is base on scheme of demand in my actual projection,the development of the project's DCS control system has been completed in this paper,it was applied to the high standard requirements for automatic sulfur control,based on the actual needs of the actual project that achieved sulfur reclaiming improving.The system has been delivered to customers who feedback system is easy to operate,safe and stable,and has deeply controlaccuracy.It has certain reference significance for the design of Claus sulfur reclaiming automatic control system.