The Study Electrical Control System Of The Sewage Treatment Station Of Beijing Changping Line Subway Depot

With the development of society and economy, the standards of living are continuingto improve, expanding capacity and scope of the human transformation of the ecologicalenvironment, it prominently need to focus on the problem of environmental protection.Sewage treatment is one of the most important parts in the environmental protection. Withthe rapid development of computer technology and our sewage treatment works, thedemands are continually increasing for the automatic degree of the sewage treatmentprocess and the use of advanced control technology and equipment to monitor the sewagetreatment process is necessary. When compared to the other foreign countries, the sewagetreatment industry in China is relatively backward. Therefore, the study of sewageautomated processing control system which is based on the computer-controll technologyhas an important practical significance.This paper describes the research of current situation and development trend ofChinese sewage treatment automatic control systems, and the process of sewagetreatment.Combined with the actual conditions of our country and sewage treatmentplants, an overall structure of the automatic control systems for sewage treatment isdesigned. What’s more, the control loop network selection in the overall structure isanalyzed and designed.According to the process characteristics and control requirements of sewagetreatment and depot sewage, the main control program flowcharts and the backwashdecision-making flowcharts are designed by PLC. The electrical control equipment:according to waste water treatment requirements, designing of the electrical controlequipment and automatic control line. Including: equipment start and stop control, statusindication, fault handling, and signal acquisition.The program development of PLC: drawing up the control requirements ofsubsystems, programming the subsystems firstly and then debugging the program of all.After one year’s commissioning and operation, the system is running stable. Thequality of depot treated sewage water is stable and has reached the national standard. Thedesign reduces the cost of sewage treatment and achieves a pre-design requirement.