CN210356706U

CN210356706U - Differential rectification system of flue gas suitable for SCR deNOx systems

Info

Publication number: CN210356706U
Application number: CN201920380663.9U
Authority: CN
Inventors: 谭厚科; 王晓青; 张健; 周静
Original assignee: Xi'an Green Power Technology Co ltd
Current assignee: Xi'an Green Power Technology Co ltd
Priority date: 2019-03-22
Filing date: 2019-03-22
Publication date: 2020-04-21
Anticipated expiration: 2029-03-22

Abstract

The utility model provides a differential rectification system of flue gas suitable for SCR deNOx systems, including spraying ammonia grid, spraying ammonia grid is last to have a plurality of branch pipe ways, its characterized in that, along the length direction of branch pipe way, all be provided with two rows of tubules on every branch pipe way, two rows of tubules staggered arrangement, and the contained angle is 30-60 °; the system also comprises two guide plates which are positioned behind the ammonia injection grid. The utility model discloses a system, in spouting the ammonia system, flue gas and ammonia misce bene degree obtain guaranteeing, and flue gas velocity distribution is more even in reactor catalyst layer.

Description

Differential rectification system of flue gas suitable for SCR deNOx systems

Technical Field

The utility model relates to a SCR flue fairing, concretely relates to differential fairing of flue gas suitable for SCR deNOx systems.

Background

The flue gas velocity field and component concentration field distribution of the flue gas inlet of the existing domestic SCR denitration equipment are uneven, and the change of the flow field caused by load change and the like causes NOx/NH₃The uniformity changes, which causes the problems of high smoke concentration, catalyst abrasion and the like, and the problems also cause the concentration of nitrogen oxides at the outlet of the SCR reactor to be uneven.

The flow guide plate is added in front of AIG (ammonia injection grid) to eliminate the speed deviation of smoke, but the concentration deviation of smoke components (mainly referring to NH)₃Non-uniform mixing with NOx) are difficult to eliminate with this device and therefore the flue length between the AIG and the catalyst must be long enough to ensure adequate flue gas diffusion, dilution and mixing time. However, the flue of the existing system is short, and NH can not be enabled₃Mixing with NOx sufficiently to make NH entering the catalyst₃the/NOx (mass ratio) uniformity cannot be guaranteed.

Disclosure of Invention

Not enough to prior art exists, the utility model aims to provide a differential rectification system of flue gas suitable for SCR deNOx systems solves the regional uneven and regional uneven problem of cross-section velocity distribution of SCR of the regional concentration distribution of ammonia that spouts.

In order to solve the technical problem, the utility model discloses a following technical scheme realizes:

a flue gas differential rectification system suitable for an SCR denitration system comprises an ammonia injection grid, wherein the ammonia injection grid is provided with a plurality of branch pipe pipelines, and the flue gas differential rectification system is characterized in that two rows of small pipes are arranged on each branch pipe pipeline along the length direction of the branch pipe pipeline, are arranged in a staggered mode, and have an included angle of 30-60 degrees; the system also comprises two guide plates which are positioned behind the ammonia injection grid.

In addition, the system also comprises a static mixer, wherein the static mixer comprises an ammonia injection pipe, a transverse matrix flat plate and a plurality of longitudinal matrix flat plates, a plurality of injection holes are processed on the pipe wall of the ammonia injection pipe along the axis of the ammonia injection pipe, adjacent injection holes are separated by the longitudinal matrix flat plates, the longitudinal matrix flat plates are connected into a whole through the transverse matrix flat plates, and the transverse matrix flat plates are parallel to the axis of the ammonia injection pipe; and a wing piece is arranged above each injection hole and fixed on the transverse base flat plate.

Preferably, an upper group of fins and a lower group of fins are arranged above each spray hole, and projections of the two groups of fins on a horizontal plane where the spray holes are located cover the spray holes.

In the present system, the shape of the fins includes rectangular, triangular, trapezoidal, oval, or polygonal.

Preferably, the ammonia injection grid is arranged into 2 rows and 14 columns of partitions.

Preferably, the small tubes are uniformly densely distributed in the flue, and 27 small tubes are arranged per square meter.

When the SCR flue gas guiding plate is used, the two guiding plates are respectively arranged at the corner of the SCR flue and the violent contraction position of the section of the SCR flue.

Compared with the prior art, the utility model, following technological effect has:

the utility model discloses a device, ammonia cigarette mist takes place first vortex through the AIG of design earlier, carries out preliminary mixing, and the static mixer of design is got into again afterwards, forms differential rectification effect, and ammonia cigarette mist further mixes, and the flue gas obtains guaranteeing with ammonia misce bene degree. Simultaneously, through another rationally arranged guide plate for flue gas velocity distribution is more even in reactor catalyst layer, and denitration entry cross-section velocity deviation is less than 15% behind the guide plate arrangement, and catalyst surface layer air current incident angle is less than 10%, and system's pressure drop is less than 1200pa, and speed distribution, incident angle, system's pressure drop isoparametric all satisfy relevant performance index after optimizing, can make SCR deNOx systems's ammonia injection volume reduce under the two aspects combined action.

Drawings

FIG. 1 is a layout view of a differential flue gas rectifier.

FIG. 2 is a schematic view of an Ammonia Injection Grid (AIG).

FIG. 3 is a schematic view of the AIG manifold and tubule arrangement.

FIG. 4 is a schematic view of a static mixer.

The meaning of each reference number in the figures is:

1-ammonia injection grid, 2-branch pipe, 3-small pipe, 4-guide plate, 5-static mixer, 6-ammonia injection pipe, 7-transverse matrix flat plate, 8-longitudinal matrix flat plate, 9-injection hole, 10-fin.

The following detailed description of the present invention will be made with reference to the accompanying drawings.

Detailed Description

The following embodiments of the present invention are given, and it should be noted that the present invention is not limited to the following embodiments, and all the equivalent transformations made on the basis of the technical solution of the present application all fall into the protection scope of the present invention.

Example 1:

as shown in fig. 1 to 4, the present embodiment provides a flue gas differential rectification system suitable for an SCR denitration system, which includes an ammonia injection grid 1, a static mixer, and two baffles. The structure of the guide plate is conventional, the difference lies in that two guide plates 4 are arranged at the rear of the ammonia injection grid 1 and are respectively arranged at the corner of the SCR flue and the violent contraction position of the section of the SCR flue, the speed deviation of the section of the denitration inlet after the arrangement of the guide plates 4 is less than 15%, the airflow incidence angle of the surface layer of the catalyst is less than 10%, the system pressure drop is less than 1200pa, and the optimized speed distribution, incidence angle, system pressure drop and other parameters all meet the related performance indexes. The ammonia injection grid 1 of the system is provided with 2 x 14 partitions, the ammonia injection grid 1 is provided with a plurality of branch pipe pipelines 2 for introducing ammonia gas, each branch pipe pipeline 2 is provided with two rows of small pipes 3 along the length direction of the branch pipe pipeline 2, the small pipes 3 form nozzles for injecting ammonia, the two rows of small pipes 3 are arranged in a staggered mode, the included angle is 30-60 degrees, the small pipes are uniformly and densely distributed in a flue, 27 small pipes are arranged per square meter, the ammonia injection grid and the small pipes are made of 304L stainless steel, and particularly at 60 degrees, the ammonia gas sprayed out of the small pipes 3 and the smoke gas vertically upwards from bottom to top can form a good rectification effect; the static mixer comprises an ammonia injection pipe 6, a transverse matrix flat plate 7 and a plurality of longitudinal matrix flat plates 8, wherein a plurality of injection holes 9 are processed on the pipe wall of the ammonia injection pipe 6 along the axis of the ammonia injection pipe 6, the adjacent injection holes 9 are separated by the longitudinal matrix flat plates 8, the longitudinal matrix flat plates 8 are connected into a whole through the transverse matrix flat plate 7, and the transverse matrix flat plate 7 is parallel to the axis of the ammonia injection pipe 6; above each injection opening 9, a wing piece 10 is arranged, which wing piece 10 is fastened to the transverse base plate 7. Especially, two sets of wing pieces 10 about every injection hole 9 top is provided with, and the projection of two sets of wing pieces 10 in the horizontal plane of injection hole 9 place all covers injection hole 9, can effectively change the ammonia disturbance route, and this kind of structural design can form fine differential vortex effect, and very ammonia cigarette intensive mixing. The shape of the fin 10 includes, but is not limited to, a rectangle, a triangle, a trapezoid, an ellipse, or a polygon, with respect to the projection of the fin 5 on the horizontal plane where the injection hole 4 is located, which can cover the injection hole.

The utility model discloses a system, ammonia cigarette mist takes place first vortex through the AIG of design earlier, carries out preliminary mixing, and the static mixer of design is got into again afterwards, forms differential rectification effect, and ammonia cigarette mist further mixes, and the flue gas obtains guaranteeing with ammonia misce bene degree. Simultaneously, through two rationally arranged guide plates for flue gas velocity distribution is more even in reactor catalyst layer, can make SCR deNOx systems's the ammonia volume of spouting reduce under the two aspects combined action.

Claims

1. A flue gas differential rectification system suitable for an SCR denitration system comprises an ammonia injection grid (1), wherein a plurality of branch pipe pipelines (2) are arranged on the ammonia injection grid, and the system is characterized in that two rows of small pipes (3) are arranged on each branch pipe pipeline (2) along the length direction of the branch pipe pipelines (2), the two rows of small pipes (3) are arranged in a staggered mode, and the included angle is 30-60 degrees; the system also comprises two guide plates (4), and the two guide plates (4) are positioned behind the ammonia injection grid (1).

2. The system according to claim 1, characterized in that it further comprises a static mixer (5) comprising the ammonia injection pipe (6), a transverse base plate (7) and a plurality of longitudinal base plates (8), wherein a plurality of injection holes (9) are formed in the wall of the ammonia injection pipe (6) along the axis of the ammonia injection pipe (6), adjacent injection holes (9) are separated by the longitudinal base plates (8), the plurality of longitudinal base plates (8) are integrally connected by the transverse base plate (7), and the transverse base plate (7) is parallel to the axis of the ammonia injection pipe (6); a wing piece (10) is arranged above each jet hole (9), and the wing piece (10) is fixed on the transverse base flat plate (7).

3. A system according to claim 2, characterized in that two sets of upper and lower fins (10) are arranged above each spray opening (9), the projections of the two sets of fins (10) on the horizontal plane of the spray opening (9) covering the spray opening (9).

4. The system of claim 2, wherein the shape of the fins (10) comprises a rectangle, triangle, trapezoid, oval or polygon.

5. The system according to claim 1, characterized in that the ammonia injection grid (1) is arranged in 2 rows and 14 columns of sections.

6. The system according to claim 1, characterized in that the small tubes (3) are arranged uniformly and densely in the flue, and that 27 small tubes (3) are arranged per square meter.

7. The system according to claim 1, characterized in that two baffles (4) are arranged at the corners of the SCR flue and at the sharp constriction of the cross-section of the SCR flue, respectively.