Design Of Drying Control System For Lignite Drum Based On S7-200-PLC

Lignite coal drying control system based on S7-200-PLC is designed.Lignite is a common fuel with large gap,high moisture content,low calorific value,high volatilization and humic acid.As for lignite,because of its high volatility,it is easy to fire and explode.In addition,because of the high water content,the traditional hot air drying method has great loss,and the drying efficiency is low.In order to develop a more safe,reliable,efficient and low energy dehydration technology,the design is based on S7-200 series PLC applied to lignite drum drying system.The specific design method is given.At the same time,the burning calorific value of lignite is greatly improved and the content of sulfur is reduced.The design main controller adopts Siemens S7-200-PLC,PLC through the network to connect to the upper control of industrial computer to complete the automatic monitoring system,considering energy saving and drying process requirements,drum drying machine,induced draft fan driven by converter,other equipment drive motor are less than 20 kw,adopting direct start way,combustion furnace and hot flue gas temperature signals from sensors and gathering,site set up on-site operation box used for equipment maintenance and debugging,on the basis of lignite drying process of PLC control program and the equipment electrical schematic diagram,a complete electric control design of the lignite drying system.The design to specify the lignite drying system based on S7-200-PLC ladder diagram of the software design method,and lists the specific program,including the program demonstrates the specific process simulation,the system design is simple,reliable and easy to implement,versatility,with minimal cost to achieve the lignite drying of high efficiency,low energy consumption of the equipment.