Zoning-regulating double-layer ammonia injection grid applied to selective catalytic reduction denitrification device for industrial flue gas

Abstract

The invention relates to the technical field of selective catalytic reduction denitrification of industrial flue gas, in particular to a zoning-regulating double-layer ammonia injection grid applied to a selective catalytic reduction denitrification device for industrial flue gas. In order to solve the problems that the ammonia distribution on a flue section of the conventional ammonia injection grid is quite non-uniform, which affects the denitrifying efficiency and increases the escape rate of ammonia, and the like, the zoning-regulating double-layer ammonia injection grid applied to the selective catalytic reduction denitrification device for the industrial flue gas divides the flue section into two equal subzones; the ammonia injection function of one subzone (1/2 of the flue section area) is realized by an upper ammonia injection grid and the ammonia injection function of the other subzone is realized by a lower ammonia injection grid; and according to the distribution rules of the flow rates of the flue gas in the two flue section subzones and different concentrations of NOx in the flue gas, the ammonia injection amount of each subzone is regulated and controlled by an ammonia injection regulating valve, so that the ammonia injection amount is adjustable on different zones of the flue section, the uniform mixing effect of the ammonia and nitrogen oxides in the flue gas is optimized, the denitrifying efficiency is improved, and the escape rate of the ammonia is effectively reduced. The uniform zoning-regulating double-layer ammonia injection grid applied to a selective catalytic reduction denitrification device for industrial flue gas has a good uniform mixing effect of the nitrogen oxides in the flue gas and the ammonia, improves the denitrifying efficiency, effectively reduces the escape rate of the ammonia, and is applicable to NOx selective catalytic reduction denitrification devices in coal burning, metallurgy, chemical industry and other industries.

Description

technical field [0001] The invention relates to the technical field of selective catalytic reduction and denitrification of industrial flue gas, in particular to a double-layer ammonia injection grid with partition adjustment function used in a selective catalytic reduction and denitrification device. Background technique [0002] Selective catalytic reduction (SCR) has the characteristics of mature technology, high removal efficiency, stable operation, and no secondary pollutants in the removal of nitrogen oxides (NOx). Currently, it is used in large and medium-sized power stations, metallurgy, and chemical industries It is widely used in the purification treatment of industrial flue gas containing nitrogen oxides. [0003] In the selective catalytic reduction method, ammonia water or liquid ammonia is generally used as the reducing agent, which is mixed with air and sprayed into the front flue of the denitration reactor. The design and adoption of a reasonable ammonia inj...

AI Technical Summary

Problems solved by technology

This design method and arrangement make the ammonia injection volume of each ammonia injection hole on each ammonia injection pipe vary greatly, resulting in extremely uneven distribution of ammonia on the flue section, and the uneven distribution of flue gas velocity on the flue section performance, which seriously affects the improvement of denitrification efficiency and increases the ammonia slip rate

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