Air distribution coupled combustion method and system for reducing NOx emissions

Abstract

The invention discloses an air distribution coupling burning method and an air distribution coupling burning system for reducing NOX exhaust, and aims at tangential burning boilers and hedging burning boilers. The coal firing amount of burners at each layer and distribution of secondary air sent into a hearth are adjusted, so under the premise of maintaining a low NOx reduction area and an unchanged excess air coefficient in a burning up area, influence on tail burning up can be reduced as much as possible while whole coal powder particles can burn under the excess air coefficient as low as possible; after adjusting is performed according to the invention, coal firing amount jetted by burners at each layer is gradually reduced from low to high along the height direction of the hearth and represents an upright pagoda structure, the coal powder fineness of certain coal mill outlets can be adjusted when necessary, but area excess air coefficients of all burning layers are approximately gradually increased from low to high and represent the upright pagoda structure, and the burning mode is also called as the upright pagoda coal controlling and reversed pagoda air distribution coupling burning mode.

Description

technical field [0001] The present invention relates to the technical field of power plant boilers, more specifically, relates to a method for reducing NO X Air distribution coupling combustion method and system for emission. Background technique [0002] With the rapid development of the national economy, the demand for electricity in society continues to grow. At present, electricity production is still dominated by coal-fired units, and the combustion of coal is usually accompanied by SO X , NO X , small particles and other pollutants. for NO X There are quite high standards for emissions, and many power plants are stepping up the implementation of low NO X Combustion and tail flue gas denitrification transformation to meet the requirements of emission standards. [0003] At present, the main combustion zone of domestic tangential combustion boilers or opposed combustion boilers usually adopts the method of equal coal control and equal air distribution. For details,...

AI Technical Summary

Problems solved by technology

In addition, in a reducing atmosphere, if the excess air ratio is further reduced, the NO x A continuous reduction in emissions, for example from about 0.8 to about 0.7 can make NO x Emissions are reduced by about 10-20%, but this may affect the burnout of the tail

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