Research On Electrical And Control System Of Seawater Desalination Project By Reverse Osmosis

The short supply of fresh water is more and more serious,and it reflects the development of our society.The seawater desalination can make fresh water without limit.The application of this technology is mature today.The technology of seawater reverse osmosis(SWRO)has made some breakthrough on some of equipment such as membrane,pump,energy recovery device for many years' practice and development.Because of the magnificent technology and economy,SWRO will be one of the most important technologies of seawater desalination.The paper is based on seawater desalination system of a thermal power plant.According to the characteristics of SWRO process,the design of electrical and control system has been researched in this paper.The research contents are as following:(1)The processes of the system are researched,which includes Coagulation and sedimentation,Ultra-filtration,Seawater Reverse Osmosis and Chemical Cleaning System.The details of every system are summarized.(2)The seawater desalination electric system is designed.The application of automatic dual power supply switching technology can improve the power reliability.It can avoid the interruption of power supply.The application of variable frequency technology can reduce the system operation consumption,save the operation cost,and enhance the advantage of seawater reverse osmosis system.(3)The seawater desalination control system is designed.Centralized control is used in this system.It can achieve the continuous monitoring of the seawater desalination system.The adopting of hot standby redundant controller improves the automaticity of the control system,and reduces workload for the operator.The PLC programming software is Unity Pro.Adequate to process control requirements,the program is optimized to guarantee the system stability.(4)The seawater desalination monitoring system is designed.The software of HMI pictures configuration is InTouch.It can show the performing data directly and also can store the data and give alarms.The maintenance is more simple and effective with this software.(5)The research and site operation show that the electrical and control system reaches the advanced level.It can fully meet the design requirements.The system runs well after it was put into operation.The work of this paper is significant of improving the power reliability,saving operation cost,improving the automaticity,and advances the application of SWRO technology.