Design And Realization Of Low Temperature Multi-Effect Distillation Seawater Desalination Monitoring System

With the increase of global population and the development of economy,the demand for freshwater resources is also increasing,the shortage of freshwater resources has become one of the major bottlenecks that affect the human survival and economic sustainable development.Seawater desalination is one of the most effective ways to solve the shortage of fresh water resources,among them,the low temperature multi-effect distillation(LT-MED)is characterized by low operating temperature,low risk of scaling and corrosion,low requirement for pretreatment of seawater,efficient use of low-grade heat source,high thermal efficiency,high quality of the product water and high flexibility of system operation,so it becomes one of the mainstream technologies of desalination.In this paper,the "12th Five-Year" 50t/d MED pilot plant(Wudi,Shandong)is selected as the research background,to study the design and implementation of LT-MED monitoring and control system.First of all,the working principle and technological process of LT-MED seawater desalination is introduced,and the general situation of the "12th Five-Year" 50t/d MED pilot plant.According to the complexity of the temperature control process of the main body of sea water desalination,nonlinear,time-varying and other characteristics,a LT-MED seawater desalination temperature controller is designed,which is based on linear active disturbance rejection control(LADRC),the simulation results show that the controller has good control effect,and it realizes the stability and accuracy of seawater desalination temperature control,which provides a guarantee for the stable and efficient operation of the system.Secondly,according to the disadvantages of the seawater desalination on-site monitoring unit,such as low real-time,poor reliability,unable to effectively share resources and other issues,this paper compares and analyzes the different remote monitoring technologies and wireless communication methods,and it combines with the actual situation and demand analysis in the field of the LT-MED seawater desalination,a LT-MED seawater desalination remote monitoring system model is established in this paper,which is based on B/S and GPRS wireless communication.The real-time data,which is collected by PLC in the field,is sent to the remote server by GPRS wireless communication,and it enables staff to remotely monitor desalination equipment.At the same time,a B/S mode is adopted in the system,it make the users can run in any browser Web parameter remote monitoring equipment,the front page is implemented using the new Ajax technology and jQuery network front-end,which improve the system performance,and provides a more friendly Web experience for users.Finally,according to the control requirements of the on-site process,the realization of the hardware equipment is confirmed,including the selection,circuit design,wiring and so on,and the entire remote monitoring system is debugged,which can remotely monitor the equipment operation status of the LT-MED seawater desalination system,what's more,whichcan save a lot of human and material costs,and it has important theoretical value and practical significance to reduce the system cost and energy consumption of desalination of LT-MED seawater desalination.