SNCR denitration lance device

Abstract

This invention discloses an SNCR denitrification spray gun device, comprising a main pipe shell with several sets of nozzles on its side wall and a liquid inlet at the top. The reducing agent solution enters the main pipe shell through the inlet and exits from the nozzles. A flow regulating baffle is installed at each nozzle, hinged to the inner wall of the main pipe shell. The baffle can rotate up and down relative to the hinge point, and the liquid flow rate at the nozzle is adjusted by changing the angle between the baffle and the inner wall of the main pipe shell. A partition wall is also provided inside the main pipe shell, with one or more flow balancing holes. This invention employs a baffle-type precise single-nozzle adjustment method, which can meet the requirements of different NOx concentration distributions in different areas, achieving precise ammonia injection, significantly improving the economic efficiency of denitrification, and meeting environmental protection requirements.

Description

Technical Field

[0001] This invention relates to an in-furnace SNCR denitrification spray gun device for power plant boilers, particularly a high-efficiency and energy-saving denitrification process for large circulating fluidized bed boilers under full-load conditions. Background Technology

[0002] Ultra-low emission standards have long been a key focus and challenge for power plants, with the main difficulties being: 1. Development constraints. With the rapid development of power plant boilers with "large capacity and high parameters," the combustion situation inside the furnace is becoming increasingly complex. Many power plants adopt a combined in-furnace desulfurization and denitrification control method, resulting in extremely large fluctuations in the NOx concentration of the original flue gas; 2. Poor denitrification economics. Currently, the horizontal flue height of power plant boilers is approximately 6-10m, and the uneven distribution of flue gas component concentrations across a large cross-section makes local denitrification difficult. To meet environmental protection requirements, the amount of reducing agent solution injected must be increased, leading to a sharp increase in denitrification costs; 3. Defects in the injection system. The flue gas velocity inside the horizontal flue is extremely high, and the current mainstream external wall reducing agent solution injection system lacks sufficient jet stiffness, failing to meet the adequate denitrification requirements in the central area of ​​the flue gas cross-section. Based on the above, this patent proposes an SNCR denitrification spray gun device to solve the above problems. Summary of the Invention

[0003] The purpose of this invention is to address the problems existing in the prior art by providing an SNCR denitrification spray gun device.

[0004] This invention is achieved through the following technical solution:

[0005] This invention provides an SNCR denitrification spray gun device, including a main pipe shell; the side wall of the main pipe shell is provided with a plurality of spray nozzles, and the top of the main pipe shell is provided with a liquid inlet, through which the reducing agent solution enters the interior of the main pipe shell and is sprayed out from the spray nozzles; a flow regulating baffle is provided at the spray nozzle, the flow regulating baffle is hinged to the inner wall of the main pipe shell, and the flow regulating baffle can be flipped up and down relative to the hinge point, so as to adjust the liquid flow rate at the spray nozzle by changing the angle between the flow regulating baffle and the inner wall of the main pipe shell.

[0006] Furthermore, the angle of the flow regulating baffle is adjusted by a control mechanism; the control mechanism is a flow control linkage, one side of the flow regulating baffle is hinged to the inner wall of the main pipe shell, and the other side is hinged to the flow control linkage; the flow control linkage is vertically distributed.

[0007] Furthermore, the nozzles and flow regulating baffles are arranged in one or more columns, with the lateral distance between two adjacent columns being equal; in each column, the longitudinal distance between two adjacent nozzles / flow regulating baffles is equal.

[0008] Furthermore, the number of flow control links is the same as the number of rows of nozzles; the flow control links are simultaneously hinged to the flow regulating baffles at the same row of nozzles, and simultaneously control the angle change of the flow regulating baffles at the same row of nozzles.

[0009] Furthermore, a partition wall is provided inside the main pipe shell, which divides the main pipe shell into two or more cavities, and one or more flow balancing holes are provided on the partition wall.

[0010] Furthermore, the number of flow balance holes is one less than the number of nozzles in a single column, and they are located 200-400 mm above each nozzle in the height direction, with a hole diameter that is one-fifth of the diameter of the main pipe shell.

[0011] Furthermore, when the main pipe shell has a cylindrical structure, the flow regulating baffle is an arc-shaped plate structure with a width of one-third to one-half of the radius of the main pipe shell; when the main pipe shell has a cuboid structure, the flow regulating baffle is a rectangular plate structure with a width of one-third to one-half of the side length of the main pipe shell.

[0012] Furthermore, the main pipe shell is vertically suspended in the upper part of the horizontal flue, and the distance between the lower end of the main pipe shell and the bottom of the horizontal flue is 1500mm.

[0013] Furthermore, the main tube housing is mounted on the horizontal flue via a fixing plate; the fixing plate is detachably and fixedly mounted on the top of the horizontal flue; the fixing plate has a threaded hole at its center, and correspondingly, the upper outer wall of the main tube housing has an external thread that matches the threaded hole, and the main tube housing is threadedly connected to the fixing plate.

[0014] Furthermore, the fixing plate is fixedly connected to the horizontal flue by bolts and nuts.

[0015] The beneficial effects of this invention are:

[0016] (1) Overall, the present invention can flexibly address the problems that arise during the denitrification process in power plant boilers, and has the characteristics of simple and convenient system, high safety factor, low accident rate and wide applicability.

[0017] (2) The horizontal flue suspended injection position adopted in this invention can ensure that the reducing agent and the flue gas flow are in full contact, increase the reaction contact area, enhance the reaction activity, and efficiently remove nitrogen oxides.

[0018] (3) The present invention adopts a baffle-type precise single nozzle precise adjustment method, which can meet the requirements of different NOx concentration distribution in different regions, achieve precise ammonia injection, and significantly improve the denitrification economy. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the SNCR denitrification spray gun device in this invention;

[0020] Figure 2 and Figure 3 This is a schematic diagram showing the arrangement of the SNCR denitrification spray gun device in this invention;

[0021] Figure 4 and Figure 5 This is a schematic diagram of a multi-stage spray gun arrangement.

[0022] Figure 6 Schematic diagram of the mounting device for the main pipe shell;

[0023] The labels in the attached diagram are:

[0024] 1. Main pipe shell; 2. Flow control linkage; 3. Partition wall; 4. Flow balance hole; 5. Flow regulating baffle; 6. Nozzle; 7. Online nitrogen oxide concentration measuring point; 8. Fixing plate; 9. Bolt and nut fasteners; 10. Horizontal flue. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] Reference Figures 1-3 This invention provides an SNCR denitrification spray gun device, including a main pipe housing 1 (made of 316 stainless steel); the side wall of the main pipe housing 1 is provided with several sets of nozzles 6 (the nozzles 6 are perpendicular to the main pipe housing 1), and the top of the main pipe housing 1 is provided with a liquid inlet. A flow regulating baffle 5 (made of 316 stainless steel) is provided 200-500mm below the nozzles 6. The flow regulating baffle 5 is hinged to the inner wall of the main pipe housing 1, and the flow regulating baffle 5 can be rotated up and down relative to the hinge point, with an adjustable angle range of 0-90°.

[0028] When the main pipe shell 1 has a cylindrical structure, the flow regulating baffle 5 has an arc-shaped plate structure with a width of one-third to one-half of the radius of the main pipe shell 1. When the main pipe shell 1 has a cuboid structure, the flow regulating baffle 5 has a rectangular plate structure with a width of one-third to one-half of the side length of the main pipe shell 1.

[0029] Specifically, if the width of the horizontal flue does not exceed 4000mm, only one set of SNCR high-efficiency denitrification spray guns needs to be installed in the center direction of the horizontal flue width; if the width of the horizontal flue exceeds 4000mm, two sets of SNCR high-efficiency denitrification spray guns need to be installed at equal intervals along the width direction of the horizontal flue. Each nozzle is responsible for a height of 2000mm. When the horizontal flue height does not exceed 6000mm, three layers of nozzles are arranged; when the horizontal flue height exceeds 6000mm, four layers of nozzles are arranged. The jet velocity at nozzle 6 should ideally reach 10–20 m / s.

[0030] In addition, to determine the denitrification effect under the same reduction dosage, a NOx concentration emission measuring point was installed horizontally in the center cylinder of the separator outlet.

[0031] In application, the high-pressure reducing agent solution enters the interior of the main pipe shell 1 through the inlet and is sprayed out from the nozzle 6, entering the horizontal flue to carry out a good denitrification reaction with the flue gas. At the same time, according to the nitrogen oxide concentration measured at the online measuring point 7, the angle between the flow regulating baffle 5 and the inner wall of the main pipe shell 1 is changed, that is, the angle and distance between the flow regulating baffle 5 and the nozzle 6 are adjusted to regulate the liquid flow rate of the nozzle 6, so as to adapt to different concentrations of nitrogen oxides and avoid the flow rate of the nozzle 6 being too large or too small, which would waste the reducing agent and affect economic benefits, or the reducing agent being insufficient and affecting the nitrogen oxide elimination effect.

[0032] Example 2

[0033] The main structure of this embodiment is the same as that of embodiment 1, except that this embodiment defines a control mechanism for the flow regulating baffle.

[0034] Specifically, refer to Figure 1 In this embodiment, the flow regulating baffle 5 is adjusted in angle by a control mechanism. Specifically, the control mechanism is a flow control link 2. One side of the flow regulating baffle 5 is hinged to the inner wall of the mother pipe housing 1, and the other side is hinged to the flow control link 2. The flow control link 2 is vertically distributed.

[0035] In this embodiment, the nozzles 6 and flow regulating baffles 5 are distributed in two columns. Each nozzle 6 is responsible for a flue gas flow area with a height of 2000mm. The two columns are symmetrically arranged on both sides of the main pipe shell 1, and the two columns of nozzles 6 are located on the same horizontal line and perpendicular to the flue gas flow direction. In each column, the longitudinal distance between two adjacent nozzles 6 / flow regulating baffles 5 is equal. In this embodiment, the number of flow control linkages 2 is the same as the number of columns of nozzles 6. The flow control linkages 2 are simultaneously hinged to the flow regulating baffles 5 at the same column of nozzles 6, which can simultaneously control the angle change of the flow regulating baffles 5 in the same column.

[0036] In other embodiments of the present invention, the arrangement can also be a three-column arrangement. When the arrangement is a three-column arrangement, the three columns are evenly arranged with an included angle of 120°, and the middle column is perpendicular to the flue gas flow direction.

[0037] In application, online nitrogen oxide concentration measuring points 7 are set inside the flue, and their positions and numbers can be set according to requirements. In this embodiment, two sets of online nitrogen oxide concentration measuring points 7 can be set, which can be used to measure the nitrogen oxide concentration in the regions on both sides of the main pipe shell 1. When the nitrogen oxide concentrations on both sides are different, the flow control linkage 2 at the corresponding position is driven according to the measured data. The flow control linkage 2 simultaneously drives the flow regulating baffle 5 at the same longitudinal nozzle 6 to rotate, thereby adjusting the flow rate of the nozzle 6 in the corresponding region to adapt to the changes in nitrogen oxide concentration in the corresponding region and achieve efficient denitrification.

[0038] This embodiment is applicable to the efficient elimination of nitrogen oxides when the concentration of nitrogen oxides is uneven in different regions.

[0039] Example 3

[0040] The main structure of this embodiment is the same as that of embodiment 1, except that this embodiment defines a control mechanism for the flow regulating baffle.

[0041] Specifically, in this embodiment, the flow regulating baffle 5 is adjusted in angle by a control mechanism. Specifically, the control mechanism is the flow control link 2. One side of the flow regulating baffle 5 is hinged to the inner wall of the main pipe housing 1, and the other side is hinged to the flow control link 2. The flow control link 2 is vertically distributed.

[0042] In this embodiment, each set of flow regulating baffles 5 is equipped with a flow control linkage 2, which can individually control the flow rate of reducing agent at each nozzle 6.

[0043] In application, online nitrogen oxide concentration measuring points 7 can be set at different locations and heights in different areas to measure nitrogen oxide concentrations at different levels. When the nitrogen oxide concentration is uneven, the flow control linkage 2 at the corresponding location is driven based on the measured data. The flow control linkage 2 drives the flow regulating baffle 5 at the corresponding nozzle 6 to rotate, thereby adjusting the flow rate at the nozzle 6 and achieving efficient denitrification. In other embodiments of the present invention, the control mechanism of the flow regulating baffle can also be set as a drive motor to achieve the same technical effect.

[0044] This embodiment is applicable to the efficient elimination of nitrogen oxides when the concentration of nitrogen oxides is uneven in different regions and at different altitudes.

[0045] Example 4

[0046] The main structure of this embodiment is the same as that of embodiment 1, except that:

[0047] Reference Figures 4-5 In this embodiment, a partition wall 3 (arranged at an angle parallel to the flue gas flow direction) is also provided inside the main pipe shell 1. The partition wall 3 is made of 316 stainless steel and is welded to the inner wall of the main pipe shell 1, dividing the main pipe shell 1 into two or more cavities. To ensure a good flow equalization effect, one or more flow balancing holes 4 are provided on the partition wall 3.

[0048] In this embodiment, the number of flow balance holes 4 is one less than the number of nozzles 6 in a single column, and they are located 200-400 mm above each nozzle 6 in the height direction, with a hole diameter that is one-fifth of the diameter of the main pipe shell 1.

[0049] Example 5

[0050] The main structure of this embodiment is the same as that of embodiment 1, except that the height of the mother tube shell 1 can be adjusted as needed.

[0051] Specifically, refer to Figure 6 In this embodiment, the main pipe shell 1 is vertically suspended in the upper part of the horizontal flue. In order to achieve a good denitrification effect, when the thickness of the ash layer at the bottom of the horizontal flue changes, it is necessary to adjust the distance between the main pipe shell 1 and the bottom of the horizontal flue to meet the denitrification efficiency requirements.

[0052] In this embodiment, the height of the main pipe housing 1 is adjusted by the fixing plate 8. Specifically, the main pipe housing 1 is installed on the horizontal flue by the fixing plate 8. The fixing plate 8 is detachably fixed to the top of the horizontal flue by bolts and nuts 9. The fixing plate 8 has a threaded hole in its center. Correspondingly, the upper outer wall of the main pipe housing 1 has an external thread that matches the threaded hole. The main pipe housing 1 is threadedly connected to the fixing plate 8. Auxiliary components are also fixedly installed on the outer wall of the main pipe housing 1.

[0053] In application, the main pipe housing 1 is threadedly connected to the fixing plate 8. The main pipe housing 1 is vertically inserted into the horizontal flue, and the fixing plate 8 is fixedly connected to the top of the horizontal flue. When it is necessary to adjust the height of the main pipe housing 1, the main pipe housing 1 is manually or automatically rotated at a certain angle (360°) through the auxiliary parts. After rotating to the appropriate position, it is stopped so that the main pipe housing 1 is away from the ash layer at the bottom of the horizontal flue.

[0054] After the application of this device is completed, the unit is shut down. The bolt and nut fasteners 9 are removed, and the main tube shell 1 and the fixing plate 8 can be completely removed for cleaning and replacement of parts. Finally, the sealing cover is sealed and connected to the top opening of the horizontal flue.

[0055] The principle and application process of this invention:

[0056] Taking a spray gun with two vertical rows and four layers of nozzles as an example, the precise ammonia injection control strategy is as follows: In the initial operating condition, all flow regulating baffles 5 are arranged vertically at 0°, forming a parallel pipe assembly structure. Based on the real-time measurement results of NOx concentration at the measuring points in the horizontal flue, the initial NOx emission concentration in each area is determined. If the NOx concentration distribution is uniform, the state remains unchanged; if the NOx concentration distribution is uneven, the reducing agent flow rate of the spray gun corresponding to the high concentration area needs to be adjusted, i.e., automatically increasing the angle of the corresponding regulating baffle, up to a maximum of 90°; after adjustment, observe the NOx emission measuring point parameters. If the value decreases while the total reducing agent flow rate remains unchanged, the state remains unchanged; otherwise, based on the existing conditions, adjust the linkage height to increase the distance between the baffle and the corresponding spray gun, thereby weakening the constraint of the baffle on flow distribution and further increasing the flow regulation margin.

[0057] Specifically, tests were conducted using this invention patent on a subcritical circulating fluidized bed boiler. Environmental assessment results showed that when the original flue gas nitrogen oxide concentration was approximately 200 mg / m³... 3 At that time, the concentration of nitrogen oxides in the clean flue gas is less than 30 mg / m³. 3 It achieves ultra-low emission standards, and the advanced PLC-controlled precise ammonia injection adjustment reduces the ammonia-nitrogen ratio from 7:1 to 3.5:1, greatly saving the production costs of power generation companies.

[0058] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions that fall within the scope of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An SNCR denitrification spray gun device, characterized in that, Including the mother tube shell (1); The mother tube housing (1) has several sets of nozzles (6) on its side wall and a liquid inlet on its top. The reducing agent solution enters the mother tube housing (1) through the liquid inlet and is sprayed out from the nozzles (6). A flow regulating baffle (5) is provided at the nozzle (6). The flow regulating baffle (5) is hinged to the inner wall of the mother pipe shell (1). The flow regulating baffle (5) can be flipped up and down relative to the hinge point. By changing the angle between the flow regulating baffle (5) and the inner wall of the mother pipe shell (1), the liquid flow of the nozzle (6) can be adjusted. The flow regulating baffle (5) is adjusted in angle by a control mechanism; the control mechanism is a flow control link (2), one side of the flow regulating baffle (5) is hinged to the inner wall of the mother pipe shell (1), and the other side is hinged to the flow control link (2); the flow control link (2) is vertically distributed; The main pipe housing (1) is also provided with a partition wall (3), which divides the main pipe housing (1) into two or more cavities. The partition wall (3) is provided with one or more flow balance holes (4). The number of flow control links (2) is the same as the number of columns of nozzles (6); the flow control links (2) are simultaneously hinged to the flow regulating baffles (5) at the same column of nozzles (6), and simultaneously control the angle change of the flow regulating baffles (5) at the same column.

2. The SNCR denitrification spray gun device according to claim 1, characterized in that, The nozzles (6) and flow regulating baffles (5) are arranged in one or more columns, and the lateral distance between two adjacent columns is equal; in each column, the longitudinal distance between two adjacent nozzles (6) is equal, and the longitudinal distance between two adjacent flow regulating baffles (5) is equal.

3. The SNCR denitrification spray gun device according to claim 1, characterized in that, The number of flow balance holes (4) is one less than the number of nozzles (6) in a single column, and they are located 200-400 mm above each nozzle (6) in the height direction, with a hole diameter that is one-fifth of the diameter of the main tube shell (1).

4. The SNCR denitrification spray gun device according to claim 1, characterized in that, When the main pipe shell (1) has a cylindrical structure, the flow regulating baffle (5) has an arc-shaped plate structure with a width of one-third to one-half of the radius of the main pipe shell (1); When the main pipe shell (1) has a cuboid structure, the flow regulating baffle (5) has a rectangular plate structure with a width of one-third to one-half of the side length of the main pipe shell (1).

5. The SNCR denitrification spray gun device according to claim 1, characterized in that, The main pipe shell (1) is vertically suspended in the upper part of the horizontal flue, and the distance between the lower end of the main pipe shell (1) and the bottom of the horizontal flue is 1500mm.

6. The SNCR denitrification spray gun device according to claim 1, characterized in that, The main pipe shell (1) is installed on the horizontal flue via a fixing plate (8); The fixing plate (8) is detachably and fixedly installed on the top of the horizontal flue; The center of the fixing plate (8) is provided with a threaded hole, and the upper outer wall of the mother tube shell (1) is provided with an external thread that matches the threaded hole. The mother tube shell (1) is threadedly connected to the fixing plate (8).

7. The SNCR denitrification spray gun device according to claim 6, characterized in that, The fixing plate (8) is fixedly connected to the horizontal flue by bolts and nuts.

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