Research On The Dynamical Behavior And Control Strategy Of Milling System

Now the ball mill pulverizing system is used widely in large-and-medium scale power plant in China. And the scale is to have an extending trend according to its present development. The tube mill is a typical MIMO system with long time delay and time changing apparently. It has the characteristics of simple lagging, great inertia and non-linearity. The mathematical model is hard to be established and changed slowly with the elapse of time. Because of the serious coupling among three outputs, if we use the traditional PID control system, the control system is difficult to put into use efficiently. And the control result is not satisfying. It is difficult to keep the pulverized system in safe condition and in low energy consumption in the same time. So, the research for boiler mill system's controlling method and the improvement of the existing ball mill pulverizing system, are one of the focuses in the field of heat engine control.This paper focuses on the main problems in the operation control for ball mill pulverizing system, proposes the dynamic mathematical model for the steel ball mill pulverizing system, and simulates the dynamic character of the system, and analyzes the dynamic responses of the system's outputs and the coupling for the mill system's dynamic procedures under different conditions. So this paper gives a thorough research work in the characteristics of the system, and dynamic two model of ball mill pulverizing system. According to each subsystem's character, proposes the ordinary PID controller and the fuzzy controller and analyzes the two control methods' own advantages and disadvantages and the existing problems.Against these characteristics of PID and fuzzy controllers, this paper proposes an intelligent PID control system and a Fuzzy-PID control system. The practical application results show that the two novel control system has many good features such as good real-time performance and effective ability of suppressing disturbances etc, and perfect result can be gotten..The PI controlling system with the ability of intelligent logic judging method, can decide to choose perfect controlling operations, according to the height of coal in the ball mill, entrance pressure and the exit temperature error, which can avoid to operate wrongly because of the inter-inference of different control. The Fussy-PID control system integrates the advantages of fuzzy control and routine control. As a result, the system can be efficient in dynamic and static control even without accurate mathematical model. Theabove two complex control method can make good use of routine controlling system, with little improving work on the spot. So, it is worth popularizing in the future.