Research And Application Of The Monitoring And Controlling System For Flue Gas Desulphurization System In Thermal Power Plant

This paper which based on modern control theory, focuses on the research of the monitoring and controlling system of the flue gas desulfuration (FGD) system for the Power Plant. The key points of this paper include the design of hardware and software of the system, and the realization of automatic control function. The system has the advantage of advanced design, easy expansion, and transplantion,highly safety, reliability and so on.Staring from both the practical conditions of the FGD system, and the advanced technologies and experiences domestically and abroad, the monitoring and controlling system adopts a total distributed control system (DCS) constituted by a programmable logic controller (PLC) and a computer (PC). PLC is used to collect data and perform automatic control, while PC is adopted to monitor the operation process and analyze data by communicating with PLC. This system enables the control system to be operating safely, reliably and economically, and brings conveniences to the operator.This paper also involves software development of PLC and PC. The software for PLC programmed on the Conductor Platform, constituted of Logic block, Calculate block, Control block and Adjust block which can successfully detects signals and controls the loops of system, has the advantages of modularization and structurization. Correspondingly, the software for PC developed by PMC proves to be effective and friendly to operators, which can realize many functions such as process display, list display of operation parameters, alarming, history querying, automatic creation of worksheet, and trend monitor, etc.The design of automatic control loops for the FGD system is also included in this paper. The system uses intelligent PID controller to design all automatic control loops, and performs the adjustment of PID parameters. In actual operation of Chongqing Shennan SP. Huayingshan Power Plant, the indexes of the FGD system all reach design demand. System works reliably, and have fine control effect.