Method for SCR ammonia injection adjustment optimization based on full-load accurate denitration requirements

Abstract

The invention discloses a method for SCR ammonia injection adjustment optimizationbased on full-load accurate denitration requirements. The method includes the following steps: acquiring a base valueof an ammonia injection flow by using change rates of a boiler feed gas amount, a denitration SCR inlet NOx parameter, a denitration SCR outlet NOx parameter as feedforward signals; with an ammonia injection flow rate as the adjustment amount, eliminating interference resistance caused by using an ammonia injection adjustment door opening degree as an adjustment amount; establishing an adjustmentcorrection circuit by using a real-time value of the SCR outlet NOx as an object and adjusting an ammonia injection amount; eliminating an offset between the SCR outlet NOx and the net flue gas NOx; providing a determination base for an ammonia injection flow measurement fault or SCR catalyst activity declining; and adding parameter shielding and loop removal functions for SCR system calibration and net flue gas calibration to keep the normal operation of the regulation loop during calibration. According to the disclosed method, with the original measurement points of the boiler SCR system ofthe power station, key functions such as ammonia injection flow misalignment correction, SCR outlet NOx and net flue gas NOx measurement deviation correction are introduced and automatic determinationand undisturbed switching strategies during the NOx meter calibration process are added.

Description

technical field [0001] The invention belongs to the technical field of coal-fired power generation, and specifically relates to an SCR ammonia injection adjustment and optimization method based on the requirement of full-load precise denitrification. Background technique [0002] Selective catalytic reduction technology (SCR) is a treatment process for NOx, that is, under the action of a catalyst, the reducing agent ammonia or urea is injected to reduce the NOx in the exhaust gas to N2 and H2O. Selective catalytic reduction technology (SCR) is also widely used in chemical boiler exhaust gas treatment to achieve effective denitrification of exhaust gas. [0003] The SCR technology in the prior art has the following problems: the large deviation between NOx and net flue gas NOx after SCR, the adjustment lag of the ammonia injection adjustment system, the excessive fluctuation of NOx during the process of changing working conditions or coal quality, etc., and it is not suitable...

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Problems solved by technology

[0003] The SCR technology in the prior art has the following problems: the large deviation between NOx and net flue gas NOx after SCR, the adjustment lag of the ammonia injection adjustment system, the excessive fluctuation of NOx during the process of changing working conditions or coal quality, etc., and it is not suitable for Requirements for ultra-low emission of units, full-load denitrification, deep peak regulation, etc.

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