Research On Temperature Modeling And Control Of Tunnel Kiln

Tunnel kiln is a kind of high temperature equipment which is used for refractory products production, and the control level of the temperature directly affects the production and quality of refractory products. Therefore, the temperature control strategy plays an important part in the tunnel kiln control system. How to design the temperature control strategy for tunnel kiln which can meet technical requirements, improve product quality, reduce energy consumption and reduce pollution is of great importance.In order to study the temperature control strategy of the tunnel kiln, the temperature model is established at first. Because tunnel kiln is very complicated, it is difficult to establish an accurate mathematical model. According to the characteristics of the tunnel kiln, the second-order plus lag time model of the tunnel kiln is identified by using genetic algorithm based on the data from the field, and the temperature model is proved to be effective.Tunnel kiln is a complicated object which has some characteristics such as big inertia, large time delay and nonlinearity. Therefore, in this paper, the ideas of predictive functional control are introduced in the tunnel kiln temperature control system. The temperature model of the tunnel kiln belongs to CARMA model, so predictive functional control algorithm based on CARMA model is deduced at first, and then the predictive functional controller is designed. Simulation results show that, when the model is matched, the dynamic response of predictive functional control is fast, process output is smooth, overshoot is of small amount and anti-interference ability is strong. However, the control performance is not ideal on the condition of model mismatch.Various interference factors exist in the actual production process and the output of the prediction model is not in full compliance with the actual output. In view of the phenomenon of model mismatch in the predictive functional control, using fuzzy inference to compensate the controlled quantity is put forward in this paper. The predictive functional controller based on fuzzy compensation of the tunnel kiln is designed. Simulation results show that, in the case of model mismatch, the predictive functional controller with fuzzy compensation can effectively overcome the negative influence of model mismatch. The system has higher control precision, faster tracking speed, less adjusting time, smaller overshoot, stronger anti-interference performance and greater robustness, so it can meet the requirements of the tunnel kiln temperature control.