Reciprocating stirring type SCR reactor flue gas flow equalizing device and working method thereof

Abstract

The invention discloses a reciprocating stirring type SCR reactor flue gas flow equalizing device and a working method thereof. The reciprocating stirring type SCR reactor flue gas flow equalizing device structurally comprises a spoiler, a reciprocating motion mechanism, a motor, a guide groove, a rectifier and the like. Rotation of the motor is converted into linear reciprocating motion through the reciprocating motion mechanism to drive the spoiler to reciprocate along the left-right direction of the flue; a disturbance perpendicular to the flowing direction of flue gas is applied to the flue gas in the flue through the spoiler, stirring and mixing of the flue gas are achieved, a temperature field, a flow field and components are enabled to be more uniform, the flow field is reintegratedthrough the rectifier arranged on the downstream, and it is guaranteed that the flow field of the flue gas entering the SCR reactor is uniform and stable.

Description

technical field [0001] The invention relates to a flue gas equalizing device for an SCR reactor, in particular to a reciprocating stirring type SCR reactor flue gas equalizing device. Background technique [0002] Selective catalytic reduction technology (SCR for short) is a denitrification technology widely used in thermal power units at present. Its technical principle is to inject ammonia (NH 3 ), under the action of catalyst and in the presence of oxygen, NH 3 It preferentially reacts with nitrogen oxides (NOx) in flue gas to generate nitrogen and water. [0003] However, for large-scale thermal power units, the flue width is large, especially for boilers with opposed combustion and W-shaped flame combustion. The gas often has a biased flow, which can easily lead to the problem that after the flue gas enters the reactor, there is relatively little ammonia liquid in some areas and insufficient reaction, and in some areas, there is relatively too much ammonia liquid, res...

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Problems solved by technology

[0003] However, for large-scale thermal power units, the flue width is large, especially for boilers with opposed combustion and W-shaped flame combustion. The gas often has a biased flow, which can easily lead to the problem of relatively little ammonia liquid in some areas and insufficient reaction after the flue gas enters the reactor, and relatively large ammonia liquid in some areas, resulting in large ammonia escape.

To ensure the safety of downstream equipment, reducing the amount of ammonia injection will make it difficult to completely eliminate NOx in the flue gas, and the denitrification rate will decrease; and if the injection amount of ammonia liquid is increased to ensure the denitrification effect, it will cause a lot of waste, and the escaped ammonia It has a great impact on downstream equipment such as air preheaters, and will cause secondary pollution to the environment

[0004] At present, there are two main ideas to solve this problem. One is to adjust the amount of ammonia injection at different positions to adapt to the deflection of the flow field. However, this method is difficult, and the deflection of the flow field varies under different working conditions. Similarly, it is basically impossible to adjust the ammonia injection grid in real time according to the working conditions; the second idea is to use a flow equalizer to improve the uniformity of the flow field before entering the SCR reactor. Currently, more flow equalizers are used Devices include static mixers, deflectors, disc mixers, etc., with different effects, but generally speaking, there is a contradiction, that is, the equipment with good flow equalization effect has high resistance, and the equipment with small resistance has poor flow equalization effect.

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