Design And Development Of Operation Monitoring And Fault Diagnosis Expert System In Sewage Treatment

Recently, domestic environmental pollution has been increasinglyaggravated, among which water pollution is particularly prominent. It isa serious constraint to the sustainable development of our society andeconomy. In consequence, governments at all levels put more and moreemphasis on prevention and control of water pollution. However, withincreasingly stringent effluent standards, the traditional sewagetreatment control system is unlikely to fulfill the important role ofdecreasing water pollution. As a result, it is quite significant to study anddevelop a sewage intelligent control system for the purpose of ensuringthe stable operation of the craft process and the water quality standards.Based on the background of industrial wastewater treatmentengineering in a industrial zone of zhuzhou city, this paper designed anddeveloped a set of sewage treatment operation monitoring and faultdiagnosis expert system, through giving insight into the sewage processcharacteristics and control requirements and combining with the latestdevelopment of intelligent control technology. The topic of this paper ismainly about some aspects as in follow:（1）Based on a thorough understanding of the technologicalprocess of the sewage treatment plant, an overall structure and functiondesign on supervisory control and data acquisition system(SCADA) wascarried out. The system consists of Schneider Premium series PLC,Vijeo Citect PC monitor and field detecting instrument etc. Ethernet ringtopology served for the system’s communication network and thesystem’s protocol was standard TCP/IP protocol. By monitoring therunning equipment on the spot, functions such as data acquisition,equipment control, parameter adjustment and all kinds of signal alarmetc. has been realized.（2）In order to perform the on-site data management in a betterway and to provide basis for the top’s decision-making, an uppermanagement system has been developed. This system can real-timelydisplay all process parameters value and equipment running time. Moreover, it also possesses functions such as historical data query aswell as automatic and manual report generation.（3）To troubleshoot problems for the operation and managementsystem of the wastewater treatment plant, this paper introduced theexpert system which uses modularized software design method.Independent knowledge base and inference engine were designed.Knowledge base modules use the representation method based on fuzzyproduction rules and inference engine module adopts the forwardinference methods based on conflict resolution and control strategy.Simulation tests showed that the system has a high diagnosticperformance. What’s more, it can perform functions such as automaticextraction of data’s abnormal symptoms, real-time display, and onlineand off-line fault diagnosis etc.After the debugging and commissioning on the entire system, theresults suggested a good effect as desired control was achieved. Thesystem is applicable to the production requirements of the sewagetreatment plant.