Optimal Control Of PH Value In Flue Gas Desulfurization Process

As the level of China's industrial development continues to increase,its economic development has entered an unprecedented golden stage.At the same time as the rapid development of various industries in the country,the issue of environmental pollution has also attracted more and more people's attention.In order to control the discharge of air pollutants,flue gas emissions from chemical plants have become the focus of governance.At present,almost all chemical plants in China are building flue gas desulfurization and denitrification plants.There are many factors that affect the desulfurization effect.Desulfurization process is actually a neutralization process,the size of the PH value affects the absorption of sulfur dioxide,the formation of sulfate and product gypsum crystallization.Based on the analysis of flue gas desulphurization process system and the actual project as the background,this paper mainly studies the automatic control system and its optimal control in the PH value control process of desulphurization slurry,designs the automatic control system of PH value,optimizes the control algorithm of PH value control link.This article first analyzes the whole system of desulfurization process,introduces the basic process flow and chemical principle of flue gas desulfurization,compares the schemes of various desulfurization systems,determines the composition of flue gas desulfurization system,analyzes the influence of desulfurization efficiency The main factors and flue gas desulfurization system control system design,process background introduction for the PH value of desulfurization process laid the foundation for optimal control.Secondly,the PH control process of desulfurization slurry is analyzed in detail.The PH value control process is a typical nonlinear and time-lag system.Combined with the actual project application,introduced sodium hydroxide as absorbent PH value control process.On this basis,the mathematical model of slurry PH value control system was obtained.Because it is almost impossible to get an accurate mathematical model,this chapter uses an engineering approximation to make the model equivalent to a first-order inertial step that ignores higher-order dynamics.Further,this paper analyzes the control framework of PH value control in flue gas desulphurization process system,proposes a hybrid control framework of feedback control,at the same time describes the control object of PH value control system,The control object of the PH control system is simplified to a non-linear system with large hysteresis to facilitate the design and analysis of the controller.Through the analysis of the basic principle of traditional PID control,fuzzy control and fuzzy PID control system,the control strategy based on fuzzy PID control is determined as the main feedback controller.Finally,a feedback control method based on fuzzy PID for PH value control system is proposed.Finally,the optimization control design for the large lag of PH value control system is designed.The main factors influencing the PH value are analyzed,and the conclusion is drawn that the PH value control system is an uncertain system with large delay.Through the analysis of the basic principle of the control method,the predictive control is determined as the main means to solve the problem of time delay.At the same time,this paper analyzes the predictor algorithm commonly used in time-delay systems and proposes a predictive optimization control method based on adaptive predictor for the PH value control system.The control object model proposed in Chapter 4 is simulated and simulated Experimental verification,simulation results show that the design of the control method has been better.