Developed And Researched Of Monitoring And Controlling System For Demonstration Project Based On Comprehensive Utilization Of Seawater

In recent years, with reducing of potassium resources on land,it’s important to develop a new kind of mention potassium imperative.70% of the earth is covered by oceans.And seawater is rich in potassium resources.Therefore,making full use of the potassium resources in seawater is of great significance. The Caofeidian Industrial Zone in Hebei is located in the heart of the Bohai Bay,which has the advantage of a unique natural environment. The demonstrating project of extracting potassium from seawater in Industrial Zone plays an important role in the large-scale development and utilization of desalination,which uses the skill of the natural zeolite extracting potassium from seawater and makes full use of the seawater of Caofeidian Industrial Zone.The background of this paper is demonstration project based on comprehensive utilization from seawater in Caofeidian,Hebei province. Automatic control system is composed by IPC,PLC,relation instrument,industrial ethernet and field-bus technology, based on production process and equipment characteristics of extracting potassium nitrate from seawater. The main content of the system includes four sections. The first section is to select patten of IPC,PLC, executive device and detection instrument. The second section is to construct netword enviroment with industrial ethernet and Profibus-DP. The third section is to write the structured application with SIMATIC STEP7 V5.4. The last section to achieve the HMI configuration and parameter self-tuning fuzzy-PID control algorithm of simulation flowcharts,remote operating interface,alarming,report form windows,user security management applying Kingview6.52 on the upper computers.Based on the object of potassium density during the process of potassium accumulation from seawater with the characteristic of a pure delay and nonlinear system,it is difficult to build accurate mathematical model and to meet the requirement of crafts with traditional PID control algorithm. Therefore, the self-tuning parameters fuzzy-PID control strategy is enforced by the configuration software, which is combined with traditional PID control and fuzzy control. In addition, the feasibility and advantages of control scheme is simulated by MATLAB.