Peripheral injection internal circulation low-nitrogen burner

Abstract

The utility model discloses a peripheral injection internal circulation low-nitrogen burner which is structurally characterized in that an air guide cylinder and an air channel shell are coaxially sleeved to form an annular air channel, the head end of the annular air channel is fixed through a first baffle to form a peripheral gas chamber, and an air grading contraction section and a mixing section are arranged at the tail end of the annular air channel; the second baffle plate is provided with an annular peripheral injection opening which is connected with a peripheral gas injection pipe, and the tail end of the injection pipe is sequentially connected with a receiving section, a conical mixing section with a fire gathering cover and an annular entrainment hole; the central gas pipe penetrates through the guide cylinder, branch pipes are arranged at the graded contraction section, and gas holes are formed in the branch pipes and the pipe ends; a flame stabilizing disc is arranged in the air grading mixing section and provided with a spinning disk, a central gas main pipe hole, branch pipe preformed holes and circumferential air holes. According to the burner, gas mixing is promoted through air classification and multi-stage injection, and generation of nitric oxide is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of burners, in particular to a peripheral injection internal circulation low-nitrogen burner. Background Art

[0002] Most of the existing burners use staged combustion technology, rich and thin combustion, and diffusion combustion, which are difficult to balance the temperature value and NOx content, and can only play a certain role in reducing nitrogen. At the same time, the unreasonable design of the air-fuel ratio leads to local high temperature or incomplete combustion, which can lead to unstable combustion and relatively high pollutant emissions in severe cases. In order to ensure the full combustion of the fuel, most designers generally adopt a design method in which the fuel and air are better mixed, but this method has a higher combustion temperature and leads to higher nitrogen oxide emissions. In order to ensure the full combustion of the fuel and further reduce nitrogen, a reasonable fuel staging method is added to organize the combustion and ensure the stability of the combustion. Therefore, how to combine multiple technologies such as fuel staging, air analysis, and flue gas internal circulation to design a low-nitrogen, high-performance burner with full combustion of the fuel is a problem that needs to be solved by engineering and technical personnel. Utility Model Content

[0003] The utility model aims to solve the problems of high nitrogen oxide emission, insufficient combustion utilization and unstable flame of common boiler gas burners by providing a peripheral injection internal circulation low nitrogen burner in view of the deficiencies of the prior art.

[0004] The utility model provides a peripheral injection internal circulation low nitrogen burner, comprising: an air guide tube, one end of the air guide tube is coaxially arranged in the air channel inside the air channel shell, a central gas pipe is coaxially arranged inside the air guide tube, a first baffle is arranged between one end of the air guide tube and the inner wall of the air channel shell, and a second baffle is directly arranged between the end of the air channel shell and the outside of the air guide tube; a peripheral gas chamber is located between the first baffle and the second baffle; the peripheral gas pipe is connected to the peripheral gas opening of the air channel shell and communicates with the peripheral gas chamber; The second baffle is provided with a plurality of peripheral ejection openings distributed in a circular shape on the periphery of the air guide tube, a plurality of peripheral gas ejection pipes are provided on the periphery of the air guide tube, one end of the peripheral gas ejection pipe is connected to the peripheral ejection opening, and a peripheral gas ejection nozzle is provided on the other end of the peripheral gas ejection pipe; a peripheral ejector receiving section is coaxially provided at the end of the peripheral gas ejection nozzle, a peripheral ejector mixing section is connected to the end of the peripheral ejector receiving section, a fire hood is connected to the outside of the peripheral ejector mixing section, and a plurality of peripheral ejection suction holes are provided at the rear end of the peripheral ejector mixing section;

[0005] An air graded contraction section is arranged inside the other end of the air guide tube, and the end of the air graded contraction section is connected to the air graded mixing section; a central gas main pipe reserved hole is arranged on the part of the central gas pipe in the air graded contraction section, the central gas main pipe reserved hole is connected to the central gas branch pipe, a central gas branch pipe hole is arranged on the side of the end of the central gas branch pipe, and a central gas branch pipe cover is arranged at the end of the central gas branch pipe; a central gas main pipe hole is arranged on the side of the end of the central gas pipe, and a central gas main pipe cover is arranged at the end of the central gas pipe; a flame stabilizing disk is installed between the air graded mixing section and the central gas pipe, and a central gas main pipe port, a plurality of flame stabilizing disk air holes, a central gas branch pipe reserved hole and a swirl sheet are arranged on the flame stabilizing disk, the central gas branch pipe passes through the central gas branch pipe reserved hole, and the central gas pipe passes through the central gas main pipe port.

[0006] Furthermore, the number of the peripheral gas ejection pipes is 3 to 6.

[0007] Furthermore, the number of receiving sections of the peripheral ejector is 3 to 6.

[0008] Furthermore, the number of peripheral ejector mixing sections is 3 to 6.

[0009] Furthermore, the number of central gas branch pipes is 3 to 6.

[0010] Furthermore, the number of the peripheral ejection and suction holes is 4 to 12.

[0011] Furthermore, the flame stabilizing disk has 6 to 20 air holes.

[0012] Furthermore, the angle of the swirl blade is 20°-60°.

[0013] The utility model has the following beneficial effects: the utility model provides a peripheral injection internal circulation low-nitrogen burner, which adds a peripheral gas injection pipe and a peripheral gas injection nozzle on the periphery, and the injected gas is mixed with the flue gas refluxed in the combustion chamber and sprayed into the furnace for peripheral combustion, thereby reducing the flame temperature and reducing the generation of nitrogen oxides. Air-injected flue gas internal circulation and peripheral injection mixing section suction holes are provided, and a flame stabilizing disk 29 and a swirl plate 28 device are provided in the air-injected mixing section to increase the suction of the rear-end flue gas, reduce the combustion temperature, and reduce the production of nitrogen oxides. Air staging, gas staging and a flame stabilizing disk are provided, and a plurality of flame stabilizing disk air holes are provided in the flame stabilizing disk, so that the central flame is more stable while reducing the temperature of the swirl plate and increasing the service life of the swirl plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is a schematic diagram of the structure of the peripheral injection internal circulation low nitrogen burner of the utility model;

[0016] Figure 2 This is a schematic diagram of the internal structure of the peripheral injection internal circulation low nitrogen burner of the utility model;

[0017] Figure 3 This is a front view of the peripheral injection internal circulation low nitrogen burner of the utility model;

[0018] Figure 4 It is a right side view of the peripheral injection internal circulation low nitrogen burner of the utility model.

[0019] Illustrations: 1-air channel; 2-central gas pipe; 3-first baffle; 4-peripheral gas chamber; 5-air guide tube; 6-peripheral gas pipe; 7-air channel shell; 8-peripheral gas opening; 9-peripheral ejector opening; 10-second baffle; 11-peripheral gas ejector pipe; 12-peripheral gas ejector nozzle; 13-peripheral ejector receiving section; 14-peripheral ejector mixing section; 15-air classification and contraction section; 16-central gas main pipe reserved hole; 17-central gas main pipe opening; 18-fire hood; 19-central gas main pipe hole; 20-central gas branch pipe; 21-central gas branch pipe hole; 22-flame stabilizing disk air hole; 23-central gas branch pipe cover; 24-peripheral ejector suction hole; 25-central gas main pipe cover; 26-central gas branch pipe reserved hole; 27-air classification and mixing section; 28-swirl plate; 29-flame stabilizing disk. DETAILED DESCRIPTION

[0020] It should be noted that, in the absence of conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present utility model will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those of ordinary skill in the art to which the present application belongs.

[0021] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0022] Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in a variety of different forms and should not be interpreted as being limited to the embodiments described herein. It should be understood that these embodiments are provided to make the disclosure of the present application thorough and complete, and to fully convey the concepts of these exemplary embodiments to those of ordinary skill in the art. In the accompanying drawings, for clarity, the thickness of the layers and regions is enlarged, and the same reference numerals are used to represent the same devices, so their description will be omitted.

[0023] See also Figures 1 to 4 The embodiment of the utility model provides a peripheral injection internal circulation low nitrogen burner, comprising: an air channel 1, a central gas pipe 2, and an air guide tube 5. One end of the air guide tube 5 is coaxially arranged in the air channel 1 inside the air channel housing 7, the central gas pipe 2 is coaxially arranged inside the air guide tube 5, and a first baffle 3 is arranged between one end of the air guide tube 5 and the inner wall of the air channel housing 7, and the central opening of the first baffle 3 is welded to the air guide tube 5. The first baffle 3 separates the peripheral gas from the air.

[0024] A second baffle 10 is directly provided at the end of the air channel shell 7 and the outside of the air guide tube 5; the peripheral gas chamber 4 is located between the first baffle 3 and the second baffle 10; the peripheral gas pipe 6 is welded to the peripheral gas opening 8 of the air channel shell 7 and is connected to the peripheral gas chamber 4, so that the peripheral gas flows into the peripheral gas chamber 4, and the second baffle 10 is used to separate the gas and the internal smoke.

[0025] The second baffle 10 is provided with a plurality of peripheral ejection openings 9 distributed in a circular shape on the periphery of the air guide tube 5. The periphery of the air guide tube 5 is provided with a plurality of peripheral gas ejection pipes 11. In this embodiment, there are 3 to 6 peripheral gas ejection pipes 11. One end of the peripheral gas ejection pipe 11 is welded to the peripheral ejection opening 9, and the other end of the peripheral gas ejection pipe 11 is provided with a peripheral gas ejection nozzle 12; the end of the peripheral gas ejection nozzle 12 is coaxially provided with a peripheral ejector receiving section 13. In this embodiment, there are 3 to 6 peripheral ejector receiving sections 13. The end of the peripheral ejector receiving section 13 is connected to a peripheral ejector mixing section 14. In this embodiment, there are 3 to 6 peripheral ejector mixing sections 14. A fire hood 18 is connected to the outside of the peripheral ejector mixing section 14, and a plurality of peripheral ejection entrainment holes 24 are provided at the rear end of the peripheral ejector mixing section 14. In this embodiment, there are 4 to 12 peripheral ejection entrainment holes 24. The gas in the peripheral gas chamber 4 is sprayed into the peripheral ejector receiving section 13 at high speed through the peripheral gas ejector nozzle 12, and then is fully mixed with the reflux flue gas in the furnace and part of the classified air in the peripheral ejector mixing section 14. At the same time, the flue gas is entrained through the peripheral ejector entrainment holes 24 to reduce the combustion temperature and the emission of nitrogen oxides.

[0026] An air grading contraction section 15 is provided on the inner side of the other end of the air guide tube 5, and the end of the air grading contraction section 15 is connected to the air grading mixing section 27. The air inside the air guide tube 5 is graded in the air grading contraction section 15, a part of which enters the air grading mixing section 27, and a part of which is combined with the peripheral fuel gas and smoke.

[0027] The central gas pipe 2 is provided with a central gas main reserved hole 16 in the air classification contraction section 15, and a central gas branch pipe 20 is welded to the central gas main reserved hole 16. In this embodiment, there are 3 to 6 central gas branch pipes 20. A central gas branch pipe hole 21 is provided on the side of the end of the central gas branch pipe 20, and a central gas branch pipe cover 23 is provided at the end of the central gas branch pipe 20; a central gas main pipe hole 19 is provided on the side of the end of the central gas pipe 2, and a central gas main pipe cover 25 is provided at the end of the central gas pipe 2; the central gas branch pipe 20 grades the central fuel, and a part of it is injected into the gas through the central gas branch pipe hole 21, and the other part is injected into the gas through the central gas main pipe hole 19. In this way, the gas is injected in multiple stages, the mixing degree of gas and air is improved, and the combustion is more stable and sufficient.

[0028] A flame stabilizing plate 29 is installed between the air classification mixing section 27 and the central gas pipe 2. The flame stabilizing plate 29 is provided with a central gas main port 17, a plurality of flame stabilizing plate air holes 22, a central gas branch pipe reserved hole 26 and a swirl plate 28. In this embodiment, the flame stabilizing plate air holes 22 are 6 to 20. The angle of the swirl plate 28 is 20° to 60°.

[0029] The central gas branch pipe 20 passes through the central gas branch pipe reserved hole 26, and the central gas pipe 2 passes through the central gas main port 17 to ensure that the gas and air are fully mixed so that the central flame burns stably. The flame stabilizing plate air hole 22 is used to inject central air and reduce the temperature on the flame stabilizing plate to prevent the swirl sheet 28 in the flame stabilizing plate from burning. The swirl sheet 28 can stabilize the central flame and increase the stability of the flame.

[0030] It can be seen from the above embodiments that the peripheral injection internal circulation low nitrogen burner of the utility model applies fuel staging, air staging, flue gas internal circulation, premixed combustion technology, gas injection technology and concentrated and lean combustion technology to the design of forced draft burners. Under the multiple effects of air staging, gas staging and gas injection, two flames are formed, namely the central flame and the peripheral diffusion flame. Complete combustion is achieved under the optimal excess air coefficient, so that the generation of nitrogen oxides is very low. Due to the swirl plates on the flame stabilizing disk and the suction holes in the mixing section of the peripheral injection tube, the entrainment of flue gas is increased, the temperature of the central flame and the peripheral diffusion flame is reduced, and the generation of nitrogen oxides is reduced as a whole, achieving an ultra-low nitrogen effect.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example.

[0033] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A peripheral injection internal circulation low nitrogen burner, characterized in that: include: An air guide tube (5), one end of the air guide tube (5) is coaxially arranged in an air channel (1) inside an air channel shell (7), a central gas pipe (2) is coaxially arranged inside the air guide tube (5), a first baffle (3) is arranged between one end of the air guide tube (5) and the inner wall of the air channel shell (7), and a second baffle (10) is directly arranged between the end of the air channel shell (7) and the outside of the air guide tube (5); a peripheral gas chamber (4) is located between the first baffle (3) and the second baffle (10); a peripheral gas pipe (6) is connected to a peripheral gas opening (8) of the air channel shell (7) and communicates with the peripheral gas chamber (4); a plurality of gas pipes (6) are arranged on the second baffle (10) Peripheral ejection openings (9) are circularly distributed on the periphery of the air guide tube (5); a plurality of peripheral gas ejection pipes (11) are arranged on the periphery of the air guide tube (5); one end of the peripheral gas ejection pipe (11) is connected to the peripheral ejection opening (9); the other end of the peripheral gas ejection pipe (11) is provided with a peripheral gas ejection nozzle (12); a peripheral ejector receiving section (13) is coaxially arranged at the end of the peripheral gas ejection nozzle (12); the end of the peripheral ejector receiving section (13) is connected to a peripheral ejector mixing section (14); a fire hood (18) is connected to the outside of the peripheral ejector mixing section (14); a plurality of peripheral ejection entrainment holes (24) are arranged at the rear end of the peripheral ejector mixing section (14); An air classification contraction section (15) is arranged inside the other end of the air guide tube (5), and the end of the air classification contraction section (15) is connected to the air classification mixing section (27); a central gas main pipe reserved hole (16) is arranged on the part of the central gas pipe (2) in the air classification contraction section (15), and the central gas main pipe reserved hole (16) is connected to the central gas branch pipe (20), and a central gas branch pipe hole (21) is arranged on the side of the end of the central gas branch pipe (20), and a central gas branch pipe cover (23) is arranged at the end of the central gas branch pipe (20); the central gas pipe ( 2) a central gas main pipe hole (19) is arranged on the side of the end, and a central gas main pipe cover (25) is arranged on the end of the central gas pipe (2); a flame stabilizing disk (29) is installed between the air classification mixing section (27) and the central gas pipe (2), and the flame stabilizing disk (29) is provided with a central gas main pipe port (17), a plurality of flame stabilizing disk air holes (22), a central gas branch pipe reserved hole (26) and a swirl plate (28); the central gas branch pipe (20) passes through the central gas branch pipe reserved hole (26), and the central gas pipe (2) passes through the central gas main pipe port (17).

2. A peripheral injection internal circulation low nitrogen burner as claimed in claim 1, characterized in that: The number of the peripheral gas ejection pipes (11) is 3 to 6.

3. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the peripheral ejector receiving sections (13) is 3 to 6.

4. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The number of peripheral ejector mixing sections (14) is 3 to 6.

5. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The number of central gas branch pipes (20) is 3 to 6.

6. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the peripheral ejection and suction holes (24) is 4 to 12.

7. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The number of the flame stabilizing plate air holes (22) is 6 to 20.

8. The peripheral injection internal circulation low nitrogen burner according to claim 1, characterized in that: The angle of the swirl blade (28) is 20°-60°.

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