Optimization Control Of Dosing System For Reverse Osmosis Seawater Desalinatio

With the rapid growth of the global population and the rapid development of the economy,the problem of fresh water resources in the world is becoming more and more prominent.In some countries and regions,freshwater resources become the main bottlenecks restricting social progress and economic development.The shortage of freshwater resources has led people to look to desalination technology.Reverse osmosis desalination technology is the basic principle of reverse osmosis technology,the process contains a multi-level process,is a complex system engineering.According to the purpose of the process and equipment,the whole process of seawater desalination can be divided into multiple stages,usually divided into three parts: seawater pretreatment,reverse osmosis process and follow-up process.Reverse osmosis seawater desalination dosing control system is the core of the entire pretreatment process.The design and analysis of the dosing control system will help to optimize the dosing system and lay the foundation for the optimal design of the dosing control.In this paper,based on the analysis of seawater desalination water treatment process,taking the actual engineering as the background,the paper mainly studies the automatic control system of seawater desalination coagulation and sedimentation and its optimal control,designs the seawater desalination dosing automatic control system,Control algorithm,using PLC-based PID algorithm to achieve the automatic control of coagulant,fuzzy PID-based reverse osmosis desalination dosing system feedback optimization control and based on the predictor of the reverse osmosis desalination dosing system feedforward Optimize the control method,and make the dosing system in the actual project to achieve,including hardware configuration and software design.The control frame of the feedforward control and feedback control is put forward,and the control object of the dosing system is described,and the control object of the dosing system is described.Simplified as a nonlinear system with large hysteresis,which facilitates the design and analysis of the controller.Through the analysis of the basic principles of traditional PID control,fuzzy control and fuzzy PID control system,the control strategy of fuzzy PID control as the main feedback controller is determined.A feedback optimization method based on fuzzy PID dosing system is proposed.The design of feedforward optimization control for the large hysteresis of reverse osmosis seawater desalination system is carried out.Firstly,the main factors influencing the dosage of coagulant and the characteristics of the controlled water quality parameters are analyzed.The conclusion is that the dosing system is a system with large hysteresis uncertainties.Through the analysis of the basic principle of the feedforward control method,the feedforward control is the main means to solve the problem of time delay.At the same time,the predictor algorithm is proposed for the time-delay system,and the feedforward optimization control method of the dosing system based on the adaptive predictor is proposed.The simulation experiment is carried out according to the proposed control object model.The results show that the designed control method has a good effect.