Deep denitration combustion method for tangential boiler

Abstract

The invention discloses a deep denitration combustion method for a tangential boiler. The hearth of the tangential boiler comprises a main combustion zone, a reduction zone and a burning-out zone; fuel coal is fed into the main combustion zone of the hearth for combustion through primary air in one or more layers of primary air nozzles; one or more layers of secondary air is introduced through secondary air nozzles in the main combustion zone; and one or more layers of burning-out air is introduced through burning-out air nozzles in the burning-out zone. The deep denitration combustion method is characterized in that an excess air coefficient in the main combustion zone ranges from 0.5 to 1.05, and the fuel coal is subjected to low oxygen combustion; an excess air coefficient in the burning-out zone ranges from 1.05 to 1.3, and the fuel coal is subjected to oxygen-enriched combustion; an amidogen reduction inhibitor is sprayed in through one or more layers of reduction inhibitor nozzles in the hearth below the burning-out air on the uppermost layer; the reduction inhibitor nozzles on the same layer are located on the same plane; and nitric oxides in smoke are reduced in a high-temperature environment in the furnace, and generation of new nitric oxides is inhibited. By adopting the deep denitration combustion method, a nitric oxide emission value at the outlet of the hearth can be obviously lowered, and ultra-low emission is realized; strict temperature windows and analysts are not needed; denitration cost is greatly lowered; combustion efficiency can also be ensured; economic benefit is obvious; and the deep denitration combustion method has wide applicability.

Description

Technical field [0001] The invention relates to a combustion method for denitration in a tangential boiler. Background technique [0002] A tangential boiler is a four-corner arrangement of burners, and coal is injected to form a tangential combustion method; the coal emits nitrogen oxides (NOx) pollutants during the combustion process, which can cause photochemical smog pollution, which will affect the human respiratory system and The survival of animals and plants will cause serious harm. my country’s latest "Emission Standard of Air Pollutants for Thermal Power Plants" (GB 13223-2011) stipulates that from January 1, 2015, all coal-fired boilers nitrogen oxides (in NO 2 Calculated) The emission limit is 100mg / Nm 3 (For the W-shaped flame furnace, the existing circulating fluidized bed thermal power boiler and the thermal power boiler completed and put into operation before December 31, 2003, the limit is 200 mg / Nm 3 ). [0003] At present, the denitration technologies that are m...

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Problems solved by technology

And because it is arranged after the exhaust air, if too much ammonia is injected, it will also cause ammonia to escape, so the requirements for the working conditions of the boiler are relatively high, and the scope of application is limited

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