An Intelligent Monitor And Control System For The Kiln Proceses

The kiln is widely used in industrial production. In this paper, we had a comprehensive research on kiln production process control system, and designed a set of intelligent monitor and control system with advanced control technologies.According to the technical flow and characters of cement rotary kiln, the control system was divided into locale layer, middle control layer, and system management layer according to the IPC & PLC & Profibus-DP field-bus scheme. The local layer realized the local data acquisition, control local instrument and execute machine. The middle control layer was constructed by a S7-300 PLC, which realize the basic logical function and the special control algorithm. The system manager and monitor layer is consisted by an IPC, which acquire production process data by communication with PLC. It realized remote monitor and control by displaying technological flow and warning interface.In system design, firing system of kiln is a multi-variant coupling non-linear system, which is the difficulty of system control. According to the autonomous and compensatory theory, the paper proposed the scheme which divided the system into temperature, air-coal ratio and negative pressure loops. In the loop we use front feed to dispose the main disturbance and construct front feed and back feed control system. Considering the big delay, non-linear and time-variable characters of kiln, intelligent technology was introduced in temperature control loop and air-coal ratio control loop. The FUZZY-PID parameter self-adaptive controller and FUZZY self-optimization controller was designed to optimize the system control scheme.In order to improve the veracity of design, and find the best parameters and structure, the advanced LSM with instrumental variable is introduced in modeling for temperature control loop and air-coal ratio control loop. The models were simulated in MATLAB with P1D control and FUZZY control;the results show that the improved control method is better than PID control method in control veracity and robustness.