Research On Mathematical Model For Intelligent Control Of Rotary Kiln

Active lime is the most important flux of slag, desulphurization anddephosphorization on converter steelmaking. Using active lime insteelmaking can shorten the smelting time and prolong the life time of furnace.Its quality and production is the important precondition of steelmaking, highquality and yield. At present, rotary kiln is the main calcination device ofactive lime at home and abroad, and the highest calcination temperature ofrotary kiln is about1350℃. After the respective process of preheater, rotarykiln and cooler, limestone becomes active lime. The calcination process ofrotary kiln is complex thermal reaction, in which there existed parametersinfluenced by each other, disturbance factors and the feature of lag,time-varying, large inertia, nonlinear and difficulty of establishing a precisemathematical model and so on. Therefore, the intelligent control of rotary kilncancination is the problem to be solved.In the paper, the basic structure and production process of the rotary kilnwas introduced. After detailed study of the working principle of rotary kiln,the main parameters of rotary kiln control, the activity of lime, coaling, feedquantity, air quantity, rotating speed and temperature and so on, were found,which contributed to the establishment of control model and the developmentof intelligent control system.Approach of linguistic equation, including LE-based steady state modeland multilevel adaptive MISO type of LE controller, are the basis ofsecondary control model, which is composed of stabilizing controller,feedforward model and constraint handing. We introduce constant-coefficientincrement model and attempt to establish variable-coefficient incrementmodel after improved disadvantage of rotary kiln of control ofconstant-coefficient increment model.In order to compute incrementalcoefficient of variable-coefficient increment model, we compute material balance and heat balance. And we correct model coefficient using thermalinfrared imaging data of head kiln.Finally, the general design and modules of the intelligent control systemof rotary kiln was designed. In the pseudocolor image processing, we try outsome transform function and give code and experiment results. In themanagement of database, reflection class and OCCI interface were introduced,and an instance of database was shown. In the process of alarm system,CWave class was introduced. At last, several interfaces of intelligent controlsystem were shown.