The Research And Design Of Intelligent Monitor & Control System For The Traveling Grate Grate Bed Temperature Field

Traveling grate-kiln pellet method has been the preferred method of pelletizing due to its advantages such as raw material adaptable,high quality,waste heat utilization,and less pollution.As the core thermal equipment,traveling grate works in the high-low temperature circumstance(normal temperature to 1050℃).Because of the complex thermal expansion and alternate thermal stress,traveling grate is short lifetime and low reliability.To construct the intelligent control system of the traveling grate grate-bed temperature field can not only reduce temperature changing and improve the pellet quality but also reduce energy consumption and prolong the service life of traveling grate. Traveling grate grate-bed temperature field is a large inertial,time delays, no-linear,distributed parameter and time-varying controlled system,so it's difficult to insure precision and stability of temperature control using classical PID controller.Therefore,this dissertation is elaborated from the following four aspects of traveling grate bed temperature field.1.Study on control model of grate-bed temperature field Stage one and two of preheating temperature field control model has been established using system identification and parameter estimation. The simulation and the field test have showed that the models are able to reflect accurately temperature field.Many suggestions for the drying stage of traveling grate are presented in this dissertation.2.Study on intelligent control method for temperature fieldThree kinds of Fuzzy-PID controller are presented in this dissertation based on the dynamic character of fuzzy control and the static character of PID control.They are simulated via combining fuzzy logic toolbox with Simulink.The simulation result shows that they have better characters both in dynamic and static than general PID controller.The whole control system adopts compound control method which includes feed-forward control and feedback control.This control method overcomes the weakness of PID control and avoids system vibration, which achieves the real-time and stably control for the traveling grate bed temperature.3.Design of the intelligent monitor and control systemConsidering the characters of 240 million ton traveling grate,this dissertation adopts industrial personal computer(IPC) and programmable logic controller(PLC) to construct the control system.The function of IPC is to show,store and print the temperature data and give alarms through running the configuration software(MCGS).S7-300 PLC takes charge of data collection,data processing and intelligent control,which uses step7 to program.Because the traveling grate is big,this dissertation adopts ET200M to collect data.And using transducer to adjust the blast volume can save energy and accurate control.4.Experimental verification for the intelligent control methodIn order to verify the effect of the controller,this dissertation designs the experimental program that is similar with the traveling grate using AE2000A instrument.The result shows that the effect of the intelligent controller is perfect,which can provide some references for traveling grate bed temperature field control system project implementation.In this dissertation,the mathematical modeling,fuzzy-pid control, automatic control and inverter technology have been explored and trialed in the application of traveling grate grate-bed temperature field monitering.This not only has a considerable reference value academically, but also has a very practical application in the real project.