Ammonia injection grid device for graded combined SCR denitrification

Abstract

The present invention discloses a hierarchical combined SCR denitrification ammonia spraying grid device. The device may include: a main pipe, each primary ammonia spraying grid is respectively connected to the main pipe, each primary ammonia spraying grid is connected to a plurality of secondary ammonia spraying grids, and a plurality of nozzles include a first nozzle provided on the primary ammonia spraying grid and a second nozzle provided on the secondary ammonia spraying grid, and the first nozzle and the second nozzle have different spraying directions. The present invention can make the distribution of the first nozzle and the second nozzle more uniform through the multiple primary ammonia spraying grids and the multiple secondary ammonia spraying grids, and because the spraying directions of the first nozzle and the second nozzle are different, when spraying ammonia, the mixing of ammonia and flue gas is more sufficient, thereby improving the denitrification effect.

Description

Technical Field

[0001] The present invention relates to the technical field of denitration, and more specifically, to a hierarchical combined SCR denitration ammonia injection grid device. Background Art

[0002] In common flue gas denitrification devices, static mixers are often set up to enhance the diffusion of ammonia and the uniformity of mixing with flue gas, to enhance disturbance, or to add spoiler elements at the nozzle position for disturbance. The disadvantage of this type of disturbance method is that the static mixer needs to be at a certain distance from the ammonia spray grid to achieve a disturbance effect, so it is often subject to the limitation of installation space. Adding spoiler elements at the nozzle position requires the installation of special spoilers on each nozzle, which increases the probability of nozzle damage and wear. The spoilers are also prone to coking, damage or falling off, resulting in a lack of spoiler effect. Secondly, the direction of the ammonia spray holes in common flue gas denitrification devices is mostly one-dimensional, facing upward, downward or at an angle to the direction of flue gas flow. The ammonia and flue gas flow field is single, and the spoiler effect is poor. In addition, the structure of the ammonia spray grid is mostly one-dimensional, which cannot enhance the disturbance of the flue gas.

[0003] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0004] The purpose of the present invention is to provide a hierarchical combined SCR denitration ammonia injection grid device to enhance the mixing of ammonia and flue gas.

[0005] To achieve the above object, the present invention proposes a hierarchical combined SCR denitrification ammonia spraying grid device, comprising a plurality of ammonia spraying units, wherein the plurality of ammonia spraying units are used to be arranged in a flue, and each ammonia spraying unit comprises:

[0006] director;

[0007] A plurality of primary ammonia injection grids, each of which is connected to the main pipe, and each of which is connected to a plurality of secondary ammonia injection grids;

[0008] A plurality of nozzles, the plurality of nozzles comprising a first nozzle disposed on the primary ammonia injection grid and a second nozzle disposed on the secondary ammonia injection grid;

[0009] The jetting directions of the first nozzle and the second nozzle are different.

[0010] Optionally, the secondary ammonia injection grid is connected to the primary ammonia injection grid through a connecting pipe, the primary ammonia injection grid and the secondary ammonia injection grid are parallel to the main pipe, the multiple primary ammonia injection grids are located in the same plane, and the multiple secondary ammonia injection grids are located in the same plane.

[0011] Optionally, the angle between the connecting pipe and the direction of smoke flow in the flue is in the range of 30 degrees to 60 degrees.

[0012] Optionally, the jetting direction of the first nozzle is the same as or opposite to the flow direction of the smoke in the flue, and the jetting direction of the second nozzle is the same as or opposite to the flow direction of the smoke in the flue.

[0013] Optionally, there are multiple first nozzles, and the jetting directions of the multiple first nozzles are parallel to each other and perpendicular to the plane where the primary ammonia injection grid is located;

[0014] There are multiple second nozzles, and the jetting directions of the multiple second nozzles are parallel to each other and perpendicular to the plane where the secondary ammonia injection grid is located.

[0015] Optionally, the first nozzle and the second nozzle each include an air inlet pipe, a connector, a contraction section, a throat, and a diffusion section that are sequentially connected;

[0016] The air inlet pipe of the first nozzle is connected to the primary ammonia injection grid, and the air inlet pipe of the second nozzle is connected to the secondary ammonia injection grid.

[0017] Optionally, the diffusion section and the contraction section are both conical, the diffusion section includes an annular side wall and a bottom wall connected to the bottom of the annular side wall, and the annular side wall and the bottom wall are provided with a first exhaust hole.

[0018] Optionally, the connecting member includes a plurality of connecting rods, one end of each connecting rod is connected to the contraction section, and the other end of each connecting rod is connected to the air intake pipe.

[0019] Optionally, each of the first-level ammonia injection grids is symmetrically connected to four second-level ammonia injection grids via the connecting pipe.

[0020] Optionally, a plurality of the ammonia injection units are arranged in pairs in the flue along the flue gas flow direction, and the main pipe is close to the outer wall of the flue.

[0021] The beneficial effects of the present invention are as follows: the distribution of the first nozzle and the second nozzle can be more uniform through multiple primary ammonia spraying grids and multiple secondary ammonia spraying grids, and since the first nozzle and the second nozzle have different spraying directions, when spraying ammonia, the ammonia and the flue gas are mixed more fully, thereby improving the denitrification effect.

[0022] The device of the present invention has other characteristics and advantages, which will be obvious from the drawings incorporated herein and the following detailed description, or will be described in detail in the drawings incorporated herein and the following detailed description, which together are used to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which like reference numerals generally represent like components.

[0024] Figure 1 A schematic structural diagram of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown.

[0025] Figure 2 A schematic structural diagram of a first nozzle and a second nozzle of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown.

[0026] Figure 3 A schematic structural diagram of a nozzle of a staged combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown.

[0027] Figure 4 A schematic structural diagram of a diffuser gas outlet end of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown.

[0028] In the figure: 1-main pipe, 2-first-stage ammonia injection grid, 3-second-stage ammonia injection grid, 4-connecting pipe, 5-first-stage nozzle, 6-second-stage nozzle, 7-diffuser section, 8-throat, 9-contraction section, 10-connecting piece, 11-first exhaust hole. DETAILED DESCRIPTION

[0029] The present invention will be described in more detail below with reference to the accompanying drawings. Although preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0030] A hierarchical combined SCR denitration ammonia spraying grid device according to the present invention is characterized in that it comprises a plurality of ammonia spraying units, the plurality of ammonia spraying units are used to be arranged in a flue, and each ammonia spraying unit comprises:

[0031] director;

[0032] Multiple primary ammonia injection grids, each of which is connected to a main pipe, and each of which is connected to multiple secondary ammonia injection grids;

[0033] A plurality of nozzles, the plurality of nozzles comprising a first nozzle disposed on the primary ammonia injection grid and a second nozzle disposed on the secondary ammonia injection grid;

[0034] The jetting directions of the first nozzle and the second nozzle are different.

[0035] Ammonia is transported to the primary ammonia injection grid and the secondary ammonia injection grid through the main pipe. Multiple primary ammonia injection grids and multiple secondary ammonia injection grids can make the distribution of the first nozzle and the second nozzle more uniform. In addition, since the first nozzle and the second nozzle have different injection directions, ammonia and flue gas are more fully mixed when spraying ammonia, thereby improving the denitrification effect.

[0036] Figure 1 The structure diagram of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the structure of a first nozzle and a second nozzle of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown. Figure 3 The schematic diagram of the structure of the nozzle of a hierarchical combined SCR denitration ammonia injection grid device according to one embodiment of the present invention is shown. Figure 4 A schematic structural diagram of a diffuser gas outlet end of a hierarchical combined SCR denitration ammonia injection grid device according to an embodiment of the present invention is shown.

[0037] Example

[0038] like Figures 1 to 4 As shown, a hierarchical combined SCR denitration ammonia spraying grid device of this embodiment includes a plurality of ammonia spraying units, which are arranged in the flue, and each ammonia spraying unit includes:

[0039] Supervisor 1;

[0040] A plurality of primary ammonia injection grids 2, each of which is connected to the main pipe 1, and each of which is connected to a plurality of secondary ammonia injection grids 3;

[0041] A plurality of nozzles, the plurality of nozzles comprising a first nozzle 5 provided on the primary ammonia injection grid 2 and a second nozzle 6 provided on the secondary ammonia injection grid 3;

[0042] The jetting directions of the first nozzle 5 and the second nozzle 6 are different.

[0043] Specifically, the secondary ammonia spraying grid 3 is connected to the primary ammonia spraying grid 2 through the connecting pipe 4, the primary ammonia spraying grid 2 and the secondary ammonia spraying grid 3 are parallel to the main pipe 1, multiple primary ammonia spraying grids 2 are located in the same plane, multiple secondary ammonia spraying grids 3 are located in the same plane, the primary ammonia spraying grid 2 is located in the same plane, which can make the ammonia spraying airflow of the second nozzle 6 more uniform when spraying ammonia, and multiple secondary ammonia spraying grids 3 are located in the same plane, which can make the second nozzle 6 spray ammonia more uniform, and the plane where the primary ammonia spraying grid 2 is located is not the same plane where the secondary ammonia spraying grid 3 is located. In addition, the primary ammonia spraying grid 2 and the secondary ammonia spraying grid 3 are parallel to the main pipe 1, and the secondary ammonia spraying grid 3 and the primary ammonia spraying grid 2 are staggered, and the secondary ammonia spraying grid 3 can act as a static mixer, and the pipelines of the primary ammonia spraying grid 2 and the secondary ammonia spraying grid 3 are more uniformly distributed in the flue, which is convenient for maintenance and overhaul.

[0044] Specifically, a stop valve is provided on the connecting pipe 4, and the angle between the connecting pipe 4 and the direction of smoke flow in the flue is in the range of 30 to 60 degrees. The angle between the connecting pipe 4 and the direction of smoke flow in the flue is in the range of 30 to 60 degrees, which can balance the length of the connecting pipe 4 and the distance between the primary ammonia injection grid 2 and the secondary ammonia injection grid 3, so that the distribution of the primary ammonia injection grid 2 and the secondary ammonia injection grid 3 can better mix ammonia with the flue gas. The connecting pipe 4 is provided with a stop valve with an adjustable flow rate, which can increase the adjustability of the local ammonia distribution and prevent excessive local ammonia injection from causing uneven ammonia distribution and excessive ammonia escape, causing environmental pollution.

[0045] Specifically, the jet direction of the first nozzle 5 is the same as the flue gas flow direction in the flue, and the jet direction of the second nozzle 6 is opposite to the flue gas flow direction in the flue. The ammonia is first evenly collected in multiple main pipes 1, and then passes to the first-level ammonia spray grid 2 by static pressure, and is sprayed downward through the first nozzle 5 of the first-level ammonia spray grid 2. The ammonia collected in the first-level ammonia spray grid 2 further enters the second-level ammonia spray grid 3 through the connecting pipe 4, and is sprayed upward through the second nozzle 6 on the second-level ammonia spray grid 3. The jet direction of the nozzle on the first-level ammonia spray grid 2 is opposite to that of the nozzle on the second-level ammonia spray grid 3, which can increase the disturbance effect of local flue gas and ammonia.

[0046] Specifically, there are multiple first nozzles 5, and the jet directions of the multiple first nozzles 5 are vertically arranged relative to the primary ammonia injection grid 2 and parallel to each other. There are multiple second nozzles 6, and the jet directions of the multiple second nozzles 6 are vertically arranged relative to the secondary ammonia injection grid 3 and parallel to each other.

[0047] Specifically, the first nozzle 5 and the second nozzle 6 each include an air inlet pipe, a connector 10, a contraction section 9, a throat 8, and a diffusion section 7 that are connected in sequence;

[0048] The air inlet pipe of the first nozzle 5 is connected to the primary ammonia injection grid 2, and the air inlet pipe of the second nozzle 6 is connected to the secondary ammonia injection grid 3. The air inlet pipe, the connecting piece 10, the contraction section 9, the throat 8, and the diffusion section 7 form a Venturi mixing nozzle to enhance the turbulent mixing of the flue gas and ammonia.

[0049] Specifically, the diffusion section 7 and the contraction section 9 are both conical, and the diffusion section 7 includes an annular side wall and a bottom wall connected to the bottom of the annular side wall. The annular side wall and the bottom wall are provided with a first exhaust hole 11, and the first exhaust hole 11 is used to enhance the mixing of ammonia gas with the flue gas during exhaust.

[0050] Specifically, the connecting member 10 includes a plurality of connecting rods, one end of the connecting rod is connected to the contraction section 9, and the other end of the connecting rod is connected to the air intake pipe.

[0051] Specifically, each primary ammonia injection grid 2 is symmetrically connected to four secondary ammonia injection grids 3 via a connecting pipe 4 .

[0052] Specifically, a plurality of ammonia spraying units are arranged in pairs in the flue along the flue gas flow direction, and the main pipe 1 of the ammonia spraying unit is close to the outer wall of the flue, which can enhance the mixing and turbulence of the flue gas and ammonia.

[0053] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A hierarchical combined SCR denitrification ammonia injection grid device, characterized in that: It comprises a plurality of ammonia injection units, which are used to be arranged in the flue, and each ammonia injection unit comprises: director; A plurality of primary ammonia injection grids, each of which is connected to the main pipe, and each of which is connected to a plurality of secondary ammonia injection grids; A plurality of nozzles, the plurality of nozzles comprising a first nozzle disposed on the primary ammonia injection grid and a second nozzle disposed on the secondary ammonia injection grid; Wherein, the jetting directions of the first nozzle and the second nozzle are different; The secondary ammonia injection grid is connected to the primary ammonia injection grid through a connecting pipe, the primary ammonia injection grid and the secondary ammonia injection grid are parallel to the main pipe, the multiple primary ammonia injection grids are located in the same plane, and the multiple secondary ammonia injection grids are located in the same plane; The angle between the connecting pipe and the direction of smoke flow in the flue is in the range of 30 degrees to 60 degrees.

2. The hierarchical combined SCR denitration ammonia injection grid device according to claim 1, characterized in that: The jetting direction of the first nozzle is the same as or opposite to the flow direction of the smoke in the smoke duct, and the jetting direction of the second nozzle is the same as or opposite to the flow direction of the smoke in the smoke duct.

3. The hierarchical combined SCR denitration ammonia injection grid device according to claim 1, characterized in that: There are multiple first nozzles, and the jetting directions of the multiple first nozzles are parallel to each other and perpendicular to the plane where the primary ammonia injection grid is located; There are multiple second nozzles, and the jetting directions of the multiple second nozzles are parallel to each other and perpendicular to the plane where the secondary ammonia injection grid is located.

4. The hierarchical combined SCR denitration ammonia injection grid device according to claim 1, characterized in that: The first nozzle and the second nozzle each include an air inlet pipe, a connector, a contraction section, a throat, and a diffusion section that are sequentially connected; The air inlet pipe of the first nozzle is connected to the primary ammonia injection grid, and the air inlet pipe of the second nozzle is connected to the secondary ammonia injection grid.

5. The hierarchical combined SCR denitration ammonia injection grid device according to claim 4, characterized in that: The diffusion section and the contraction section are both conical, and the diffusion section includes an annular side wall and a bottom wall connected to the bottom of the annular side wall, and the annular side wall and the bottom wall are provided with a first exhaust hole.

6. The hierarchical combined SCR denitration ammonia injection grid device according to claim 4, characterized in that: The connecting member includes a plurality of connecting rods, one end of each connecting rod is connected to the contraction section, and the other end of each connecting rod is connected to the air inlet pipe.

7. The hierarchical combined SCR denitration ammonia injection grid device according to claim 1, characterized in that: Each of the first-level ammonia injection grids is symmetrically connected to four second-level ammonia injection grids through the connecting pipe.

8. The hierarchical combined SCR denitration ammonia injection grid device according to claim 1, characterized in that: A plurality of ammonia spraying units are arranged in pairs in the flue along the flue gas flow direction in the flue, and the main pipe is close to the outer wall of the flue.

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