Design And Implementation Of AAO Bioreactor Control System Based On PLC

AAO bioreactor plays an important role in the sewage treatment process of urban sewage treatment plant.Realizing the industrial process automation of the part of AAO bioreactor can reduce the production and operation costs of sewage treatment plant,and is conducive to the efficient reuse of water resources,which has important practical significance.The work and innovation of this paper are accomplished by investigating the project of expanding capacity and upgrading bidding of a sewage treatment plant in Rizhao City,Shandong Province.The process flow of AAO biological reaction pool in sewage treatment plant is introduced.The design and development of automatic control system and monitoring subsystem in AAO system are elaborated in detail.The design and test of PLC software and hardware for automatic control mode are introduced.System integration based on PROFIBUS fieldbus.This paper investigates the current domestic and foreign sewage treatment control system and the sewage treatment process of AO biological reaction tank,and studies the automatic control and monitoring subsystem in the project of expanding capacity and upgrading bid of the sewage treatment plant.Traditional automatic control system is difficult to meet the production requirements of sewage treatment plants.The design of automatic control system in this paper chooses S7-300,a highly reliable programmable controller produced by SIEMENS Company of Germany,and ForceControl of three-dimensional force control company as configuration software.Through EtherNet network based on TCP/IP protocol,the lower control system and upper monitoring subsystem are realized.Interconnection.The upper computer displays real-timemonitoring signals of on-line instruments and hardware transmitted from the scene,and receives operation instructions from central control room operators.The upper monitoring subsystem provides user login,real-time process flow chart,instrument hardware parameter setting,real-time analog data curve,historical analog data curve,event recording,screen switching,alarm and report processing and printing interface for display and operation functions.Real-time data transmission of on-line instruments is one of the key links of the whole automatic control system in AAO bioreactor.Design PLC as DP master station,new standard controller SC1000 as DP slave station,connect SC1000 to PROFIBUS-DP interface integrated on CPU,realize the integration of PROFIBUS field bus,and greatly reduce the efficiency and cost of real-time data transmission of online instruments.Finally,the AAO system is tested.As the result of this paper,the control system of the AO bioreactor based on PLC has been designed and implemented.It can not only meet the requirements of the process,but also save energy and environmental protection,achieve sustainable development,and achieve the desired goal.