Control method for unbypassed booster fan of desulphurization system

Abstract

The invention discloses a control method for an unbypassed booster fan of a desulphurization system. The control method for the unbypassed booster fan of the desulphurization system comprises the following working conditions: when a unit normally runs, an opening command of a moving blade of the booster fan jointly consists of a regulatory signal of a proportion integration differentiation (PID) regulator and a feedforward signal formed by opening of a stationary blade of a induced-draft fan or the total blast volume of a boiler, wherein the feedforward signal serves as input by the opening of the stationary blade of the induced-draft fan or the total blast volume of the boiler and is obtained through an object transfer function which corresponds to the opening of the stationary blade of the induced-draft fan or the total blast volume of the boiler; when runback (RB) is caused to the unit when equipment trips abnormally, the opening command of the moving blade of the booster fan jointly consists of the regulatory signal of the PID regulator and a control signal formed by the abnormally tripping equipment, wherein the control signal serves as input by current unit load and is obtained through an object transfer function which corresponds to the abnormally tripping equipment. Therefore, the control problem of the booster fan of the desulphurization system when the RB occurs on the unit is solved, so that the inlet pressure of the system can be controlled to be within a proper range by the booster fan when the RB occurs on the unit, and the unit cannot trip due to the fact that the pressure fluctuation is high.

Description

technical field [0001] The invention relates to the field of thermal power generation, in particular to a control method for a booster fan of a desulfurization system without a bypass. Background technique [0002] The resistance of the desulfurization system is mainly composed of four parts: absorption tower, flue gas heat exchanger, demister and flue resistance. According to the research on the desulfurization system of most 600MW units of Guohua Electric Power, under the full load of the boiler, the resistance of the absorption tower is 1200Pa, the resistance of the demister is 200Pa, the resistance of the flue gas heat exchanger is 580Pa, and the resistance of the flue gas is 500Pa. The actual resistance loss is about 2480Pa, and the flue resistance increases nearly 4 times. Because the desulfurization system and the boiler air and smoke system are designed separately, the output of the induced draft fan cannot meet the needs of this working condition. According to the ...

AI Technical Summary

Problems solved by technology

[0007] The embodiment of the present invention proposes a control method for the booster fan of the desulfurization system without bypass, which solves the control problem of the desulfurization booster fan during the rapid load reduction (RB) of the unit, and makes the booster fan during the rapid load reduction (RB) of the unit It can control the inlet pressure of the system in an appropriate range, and will not cause the unit to trip due to large pressure fluctuations

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