The Application of DCS in Peripheral Coal-Bearing Sewage Treatment System of a Power Plant

摘要

Coal-bearing sewage treatment system is one of peripheral auxiliary systems in power plants. Wash-water in coal-carrying system is treated up to the water quality standard for living water sources. Worked coal slime is transported to coal yard. Currently, control systems of main equipment and system in power plants are mainly used DCS. But in peripheral auxiliary systems, many subsets are mainly used the analog meter system or program control system, and the production efficiency is much more reduced. The DCS for coal-bearing sewage treatment is designed in this study. The DCS consists of three layers; they are upper, middle and lower layer respectively. The lower layer, is composed of data acquisition module, RS-485 communication module and control signal output module. It accomplishes on-site monitoring and communicates with the middle layer Industrial control computer in middle layer performs remote monitoring, and forms TCP/IP network with PC in upper layer. The upper PC accomplishes the task of data supervision and Web release. Users can browse data and can also participate in the management of system. Monitoring program is programmed with SCADA (Supervisory Control and Data Acquisition) software, and a small expert system is constructed on run rulers and operation experience. It is laborsaving, as the real-time treatment and control is adopted. Antijamming technique is adopted in software and hardware. The system has many merits such as less investment, reliable function, and convenient upgrade. Moreover, abundant system information of running and analyzing can also be acquired, which have important value in process control field.