Rotary vane type SNCR (Selective Non-catalytic Reduction) denitration mixing system for pulverized coal boiler and working method thereof

Abstract

The invention discloses a rotary vane type SNCR (Selective Non-catalytic Reduction) denitration mixing system for a pulverized coal boiler and a working method thereof and belongs to the technical field of SNCR. A rotary vane mixer composed of a plurality of rotary vanes with the swirling number less than 0.6 is arranged in a horizontal flue, so that flue gas flow which is mixed with reducing agents which are sprayed out from a first reducing agent spraying point and a second reducing agent spraying point passes through the rotary vane mixer to form weak rotational flow, so that the mixing between flue gas and the reducing agents is enhanced, the contact probability between reducing agent liquid drops and molecules including NOx and the like in the flue gas is improved; the whole retentiontime of the flue gas is prolonged and the time for staying in an optimal denitration temperature region is prolonged; the SNCR denitration efficiency is improved and the denitration specific gravityof an SCR (Selective Catalytic Reduction) reactor of the pulverized coal boiler is reduced; the volume of a catalyst is reduced and the denitration operation cost is reduced; meanwhile, the system cabbe used for reducing the escaping of the reducing agents and is beneficial to ash coke on a follow-up tail heating area.

Description

Technical field [0001] The invention belongs to the technical field of pulverized coal stove SNCR, and specifically relates to a rotary vane type SNCR denitration mixing system for a pulverized coal stove and a working method thereof. Background technique [0002] Among the air pollutants emitted by coal-fired power generation, NOx is a major air pollutant. NOx and hydrocarbons can cause photochemical pollution under the action of strong light. NOx emitted into the atmosphere is the main cause of acid rain. Seriously endanger the ecological environment. At present, about 65% of NOx in the country is produced by coal combustion. Therefore, power station boilers and industrial boilers, which are the main coal-burning equipment, have become the focus of attention in the future to control NOx emissions. [0003] In general, the methods of controlling NOx emissions are mainly divided into the following three aspects: pre-combustion control, during-combustion control and post-combustion...

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