Design Of The Automatic Control System For Coal Transportation Of Chemical Plant

The fuel of chemical plant is coal. Coal transporting system is an importantauxiliary system of chemical plant. There are multiple types of equipment in coaltransporting system, the layout is dispersed, working status of each device isdifferent, and the start and stop are required in a certain order between theprocesses of devices. A reliable control system has important implications for thecoal system to work in normal operation.Coal transporting system of chemical plant is regarded as a research objectin this paper, in accordance with equipment protection and interlockingrelationships, automatic control of equipment for coal transporting system isrealized. A programmable controller is used to build into a distributed controlsystem and Siemens S7-400series are used to constitute the system hardware. Amaster station and four I/O sub-stations are consisted of the system.PROFIBUS-DP network is used to communicate with each PLC control systemand the host system. Ethernet is used to communicate with PLC systems and PCsystem.The coal subsystem and coal blending subsystem are included in coaltransporting system. Based on coal blending process, interlock conditions andinterlock control requirements, the control method of coal and coal blending aredescribed, the control system of coal and coal blending are designed. Dependingon the hardware requirements of the system to select the appropriate PLCmodule.An important equipment of ball mill pulverizing system is also associatedwith the coal transporting system. It is also an important goal of energy savingfor the plant. According to the working characteristics of the ball millpulverizing system and control requirements, the multi-variable fuzzy controlstrategy is brought forward, which employs a triple-input triple-outputmulti-variable fuzzy controller. The fuzzy variables, control rules and control table are determined, while the membership function and clarity of function areselected. The use of simulation software for fuzzy control algorithm is validated.Simulation results show that the algorithm can meet the control requirements.Configuration software is used to realize interactive features. Host computermonitoring system can view the real-time operating data of each device in coaltransporting system, change control mode, view historical data and otherfunctions.The control system enables the coal transporting system in the automaticoperation. It is able to meet the production safety, improvement of productionefficiency and economic benefits.