Cement decomposing furnace temperature control method based on constraint smith GPC

Abstract

The invention relates to a cement decomposing furnace temperature control method based on constraint smith GPC, which includes variable selection, model recognition, optimizing computation, constraint processing and feedforward compensation; the variable selection includes that: coal powder flow is selected as a control variable, raw flow is selected as the feedforward variable and the decomposing furnace temperature is selected as the controlled variable; the model recognition includes that: the model recognizer based on least square method and retardation time estimation time is adopted to obtain a pulse transfer function model; the optimizing computation includes that: the future output state is predicated and the reference track w of the output value is also set; a secondary performance index controller is adopted for the rolling optimization, the control increment Delta u of the current time is computed to obtain control action value u through addition; the constraint processing includes that: the control variable and controlled variable are respectively performed with constraint amplitude limiting processing; the feedforward compensation includes that: the dynamic compensation principle is utilized to compute the current time t added to the feedforward control action value ud. The invention has simple recognition process, less adjustable parameters, good tracking performance, strong robustness, effectively refrains the disturbance influence caused by raw material flow and prevents saltus step of the system variable.

Description

technical field [0001] The invention relates to the field of cement production process control, in particular to a cement decomposition furnace temperature control method based on constrained Smith generalized predictive control. Background technique [0002] The cement calciner is the key equipment in the production process of new dry process cement. It undertakes the task of decomposing most of the carbonates in the raw meal. The stable operation of the material production line is very important. [0003] The structure of the calciner is as figure 1 shown. In the calciner, pulverized coal, tertiary air, preheated raw material and high-temperature flue gas from the rotary kiln are sprayed to achieve full mixing of gas and materials to complete combustion and decomposition. In this process, a large number of exothermic and endothermic reactions occurred among the wind, coal and raw materials, showing complex nonlinear dynamic characteristics; The calciner is far away, so...

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 0.3, it is difficult for PID control to obtain a good control effect

Although its improvement can be better than ordinary PID control, it does not fundamentally solve the adverse effects of large lag

The intelligent

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