SCR denitration system ammonia spraying optimization method based on weight valve regulation and control

Abstract

The invention discloses an SCR denitration system ammonia spraying optimization method based on weight valve regulation and control. The method is divided into four steps: measurement of flue gas flow field characteristics, analysis of flue gas flow field regional flow characteristics, determination of ammonia spraying weight valves and pertinence adjustment of opening degrees of the ammonia spraying valves. The method comprises the particular steps: firstly, measuring the flue gas flow field characteristics of a flue transverse section in front of an ammonia spraying grille of an SCR denitration system under a condition of constant load; then combining with a distribution condition of spray nozzles of the ammonia spraying grille, and analyzing flue gas flow field regional flow continuous distribution characteristics matched with the ammonia spraying spay nozzle distribution; according to the flue gas flow field regional flow characteristics under various load conditions, obtaining the weights of the ammonia spraying valves; and finally, adjusting the opening degrees of all the valves according to the valve weight difference, simultaneously, with the help of a flue gas analyzer, measuring the NOx outlet concentration on an outlet section of the SCR denitration system, and timely feeding back the adjustment effect of the opening degrees of the ammonia spraying valves. The method can ensure good ammonia nitrogen mixing equivalent ratio, effectively improves the denitration efficiency, decreases the ammonia escape and reduces the ammonia amount.

Description

technical field [0001] The invention relates to an optimization method for ammonia injection in an SCR denitrification system based on weight valve regulation, and belongs to the technical field of air pollutant control of coal-fired boilers. Background technique [0002] Air pollutants nitrogen oxides (NO x ) is one of the main sources of air pollution. It is an important cause of environmental problems such as acid rain, photochemical smog, smog, and ozone layer holes. In recent years, the state has imposed NO x The regulation of emissions has been continuously strengthened. Selective catalytic reduction (SCR) flue gas denitrification technology has become the most widely used flue gas denitration technology for coal-fired boilers at home and abroad due to its advantages of high technology maturity, high denitrification rate, good reliability and low secondary pollution. The denitrification efficiency of the SCR flue gas denitrification reaction directly depends on the N...

AI Technical Summary

Problems solved by technology

[0006] Technical problem: In order to solve the shortcomings of the current ammonia injection control technology for SCR denitrification systems, the present invention discloses an optimization method for ammonia injection in SCR denitrification systems based on weight valve regulation, which realizes the flue control of each ammonia injection port based on boiler load fluctuations The precise matching of the distribution characteristics of the flow field in the watershed and the required amount of ammonia injection can effectively solve the problems of poor mixing uniformity of ammonia nitrogen equivalent, high ammonia injection amount, excessive ammonia escape, and low denitrification efficiency caused by the current uniform ammonia injection.

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