Method for intelligently controlling pressure difference of cement raw meal vertical mill

Abstract

The invention discloses a method for intelligently controlling the pressure difference of a cement raw meal vertical mill. In the method, internal pressure difference of the mill is taken as a major controlled variable, external circulating current is taken as an auxiliary controlled variable, a feeding amount is taken as a major control variable, and a water spray amount is taken as an auxiliarycontrol variable. The method comprises the following steps of: judging a current production condition according to the internal pressure difference of the mill and external circulating current information with a production rule method; and under the normal working condition, controlling the internal pressure difference of the mill by adopting GPC-PID (Generalized Predictive Control-Proportion Integration Differentiation). In the method, a mathematic model for describing the change of the pressure difference along with the feeding amount can be established only by using input and output data of a process without analyzing the complex material milling process of the raw meal vertical mill, the identifying process is simple, and online identification is available; the method has certain adaptability to the change of the production condition; and the advantages of multistep prediction, rolling optimization and feedback correction of a GPC algorithm as well as the advantages of easiness and high robustness of a PID algorithm are fully utilized, so that the labor intensity of field operating personnel is lowered greatly.

Description

technical field [0001] The invention relates to the field of cement production process control, in particular to an intelligent control method for the pressure difference of a cement raw material vertical mill. Background technique [0002] Vertical roller mill (referred to as vertical mill) is the key raw material grinding equipment in the new dry process cement production process, which is responsible for grinding and drying materials. Therefore, effective control of the pressure difference inside the vertical mill and the temperature of the gas exiting the mill is crucial to the stable operation of the entire raw meal production line. [0003] Cement raw meal grinding process such as figure 1 shown. After limestone, iron powder, sandstone and clay are batched by the batching station, they are sent to the mill by the belt conveyor. The material is crushed and ground by the relative movement between the grinding disc and the grinding roller. The hot air flow sent from t...

AI Technical Summary

Problems solved by technology

Studies have shown that when the ratio of the lag time to the time constant of the process is greater than 3, it is difficult for PID control to obtain a good control effect

Manual adjustment not only increases the labor intensity of the operator, but also the control effect of the pressure difference is not stable enough, often fluctuates, and it is difficult to meet the process requirements

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