An intelligent control method for main steam pressure of supercritical or ultra-supercritical unit boiler

Abstract

The invention discloses an intelligent control method for a main steam pressure of a supercritical (ultra-supercritical) unit boiler. The method comprises adjustment of variables required by a boiler master controller and adjustment of a main steam pressure set value, wherein during the adjustment of the variables required by the boiler master controller, the main steam pressure set value and a feed-forward quantity are controlled and adjusted according to an actual main steam pressure variation rate; and during the adjustment of the main steam pressure set value, a pressure adjustment sliding pressure curve of the main steam pressure is acquired at first, a positive constraint value and a negative constraint value are determined for the adjustment sliding pressure curve of the main steam pressure so as to form a pressure set value constraint face used for the adjustment, control rules of the pressure set value inside and outside the constraint face are then established, and whether the boiler master controller adjusts the main steam pressure is determined according to the control rules. In a conventional main steam pressure control system, the method disclosed by the invention has the advantages that random errors existing in actual adjustment courses are overcome; the main steam pressure under rapid AGC load variation is adjusted stably; a load response rate of a supercritical unit is increased effectively; and safety and economic efficiency of unit running are improved.

Description

technical field [0001] The invention belongs to the technical field of industrial process control, and in particular relates to an intelligent control method for the main steam pressure of a supercritical or ultra-supercritical unit boiler, which is a generalized intelligent control of the main steam pressure of an ultra (super) critical unit operating on the basis of a sliding pressure constraint surface method. Background technique [0002] At present, the ultra (ultra) critical unit adopts the variable pressure once-through boiler. The once-through boiler-steam turbine is a complex and multi-variable controlled object. The main steam pressure is an important output of the system and one of the most important parameters of the thermal system. The main feature of super (super) critical unit is that it has strong nonlinearity. In the case of satisfying the rapid load change, the main steam pressure is prone to large fluctuations. The fluctuation of pressure will cause a seri...

AI Technical Summary

Problems solved by technology

Due to the large hysteresis and nonlinear characteristics of ultra (super) critical units, this conventional control strategy has poor anti-disturbance ability in the normal adjustment process, and may cause unnecessary disturbances due to the mismatch of various parameters of the unit

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