Design And Implementation Of Monitor And Control System In Sewage Disposal

Along with rapid growth of global population and high-speed development of global economy, the global water condition deteriorates day by day. In order to go out "the water crisis" difficult situation, on the one hand we should call for save on water,rational utilize water resources,fully realize the comprehensive benefits of water resources,on the other hand, we must take some measures to treat the wastewater, enables it to achieve the emission standard, prevents surface and groundwater resources from pollution as well as the ecological environment from destroying.According to the process features and control requirements of Yuxi Yinhe chemical industry's wastewater disposal system, this paper puts forward a program of the wastewater disposal DCS which is based on OMRON PLC and Citect 6.0.Firstly, this paper introduces in detail the process flow of wastewater disposal. and designs the distributive control system in wastewater disposal plant based on 3-tiered architecture(Ethernet, Controller Link, Devicenet)of OMRON PLC.Secondly, according to control objective of each part and the features of actuator,this paper designs PLC program of each part of wastewater disposal process and emphasizes on studying PID control algorithm of dissolved oxygen in SBR craft.Upon the completion of the PLC control task, This system adopt sysmac way protocol to realize communication between upper computer and PLC.According PLC programmer,we design the monitor pictures based on citect6.0 which is software development platform.Through the monitor pictures we could monitor realtime parameter and get the realtime information. Monitor pictures includes general flow picture,control pictures of each part, trend pictures, alarm pictures and PID control picture. According the need and the necessity of building remote monitor of Yuxi Yinhe chemical industry's wastewater disposal system, this paper puts forward a program of remote monitor based on ODBC and WEB thchenology.Finally, concluded the main work of this paper, summarized the main contents of this paper, and pointed out the inadequacy existing in this system and areas for improvement.The whole DCS continued have been running for one year after production. It has a capacity to treat wastewater up to 12000m3/d, and ultimately realized the win-win situation of environmental protection and economic benefits.