A method for adjusting and optimizing scr ammonia injection based on the requirement of full-load precise denitrification

Abstract

The invention discloses a method for adjusting and optimizing SCR ammonia injection based on full-load precise denitrification requirements, comprising the following steps: using the change rate of boiler flue gas volume, denitrification SCR inlet NOx, and denitrification SCR outlet NOx parameters as a feedforward signal to obtain Output the basic value of the ammonia injection flow rate; use the ammonia injection flow rate as the adjustment value to eliminate the anti-interference caused by the ammonia injection adjustment door opening as the adjustment value; establish an adjustment and correction loop based on the real-time value of the NOx at the SCR outlet to adjust the ammonia injection rate. eliminate the deviation between SCR outlet NOx and net flue gas NOx; provide judgment basis for ammonia injection flow measurement failure or SCR catalyst activity decline; add parameter shielding and circuit cut-off functions during SCR system calibration and net flue gas calibration to maintain Normal operation of the regulation loop during calibration. This method uses the original measuring points of the SCR system of the power plant boiler, introduces key functions such as the correction of the misalignment of the ammonia injection flow, the correction of the measurement deviation of NOx at the SCR outlet and the NOx of the net flue gas, and adds automatic judgment and non-disturbance switching during the calibration process of the NOx meter. Strategy.

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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