Design And Application Of Control System For Water Ultrafiltration Process Based On PLC

China is a country with extremely poor freshwater resources.However,at present,there are still many problems in China,such as low utilization rate of water resources,large amount of waste,serious pollution and so on,which makes the serious shortage of water resources even more serious.In view of this serious problem,it is an effective way to develop water reuse technology vigorously.Compared with developed countries,China's reclaimed water reuse technology started relatively late.Although some achievements have been made in recent 10 years,the whole industry still lags behind developed countries due to lack of funds and backward technology.Firstly,the technological process of domestic and foreign reclaimed water reuse system is studied,and various reclaimed water reuse systems are compared.The advantages of Ultrafiltration Membrane Reclaimed Water reuse system are pointed out,and the future technological development trend is analyzed.The technological process of ultrafiltration membrane water reuse system was analyzed and studied,and the working principle and steps of the system were clarified.According to the research,a process automatic control system for the UF membrane water reuse system is proposed and designed.The control mode of "host computer + PLC + HMI" is adopted to realize the functions of automatic control,data acquisition,report printing and quality control of the UF membrane water reuse system.This control system not only makes the whole production process to the degree of automation,but also can carry out real-time monitoring of each process in production,ensuring the stable and efficient operation of the system.The control system uses S7300 PLC controller as the core,and controls the controlled objects to act according to the process flow through PLC.According to the process flow,a set of automatic control program is compiled,which has the functions of automatic water production,regular cleaning of ultrafiltration membrane group,fault alarm and so on.According to the working characteristics of ultrafiltration membrane group,PID control algorithm is introduced to ensure that the ultrafiltration membrane system works in a stable state.According to the working characteristics of ultrafiltration membrane,a set of automatic control system is designed and completed,which realizes the full automation of production process,and the system runs steadily,has high reliability and high production efficiency.It has certain reference value for the design and implementation of medium water reuse system.