Chain Grate-rotary Kiln Coal Preparation System Energy-saving Design And Automatic Coal Injection Control Algorithm Research

At present,the domestic and international market competition is becomingincreasingly fierce and the price of energy is more and more high, so the profits of theenterprise space is more and more small. In this context, saving energy and reducingconsumption, improving the quality of the products is the route one method must betaken that the enterprise can survival and development. Iron ore pellet is anindispensable metallurgical raw material in the production of iron and steel, China’sannual need tons of pellets used in steel production, the main production equipment aspellet chain grate-rotary kiln device in the production need to consume a largeamount of coal as fuel, is the major energy-consuming equipment in pellet production.Therefore, How to make use of waste heat resource of the system and control theamount of pulverized coal injection blow to reduce the coal consumption, improve thepellet quality and reduce the cost is the key of pellet production.In this paper the research mainly around the grate-kiln system of energy-saving,emission reduction and products quality improvement. Firstly, aiming at the status ofheat resources wasted serious, this paper analysis the chain grate machine-rotary kilnhot workers system and system heat balance in-depth, through calculation analysis,put forward a kind of grate-kiln system waste heat recovery methods that part of thehot exhaust gas waste heat utilization method of the rotary kiln for pulverized coalpreparation system dry, reduce coal link energy consumption, and proposes theimplementation of waste heat recovery system. Secondly, aiming at the status of lowlevels of coal powder injection control system of rotary kiln, coal-intensive roastingtemperature fluctuations, unstable product quality, kiln ring formation in a serioussituation, this paper proposed a rotary kiln automatic injection control algorithm toreduce coal consumption, improve the quality of products. During the rotary kilnroasting, calcination temperature has features of large delay, nonlinear and manydisturbance factors, it is difficult to use conventional control methods determine theexact amount of pulverized coal injection, this article therefore decided to introducethe intelligent control technology to rotary kiln in pulverized coal injection control,proposed a combination of model-based control and feedback control of complexcontrol algorithms to achieve the automatic injection of pulverized coal. The controlalgorithm is composed by coal powder injection amount prediction model based onPCA-RBF neural network and feedback control model based on Nonlinear-PID. Thealgorithm through PCA-RBF control model determines the initial amount ofpulverized coal injection, and adjusts the quantity of coal injection by Nonlinear-PIDfeedback controller based on rotary kiln hood temperature. The simulation resultsshow that, the algorithm can improve the accuracy of pulverized coal injection control, stability of rotary kiln calcination temperature, reduce coal consumption and improvethe quality of the products.