CN113339794B

CN113339794B - Low nitrogen burner

Info

Publication number: CN113339794B
Application number: CN202110546470.8A
Authority: CN
Inventors: 刘旋坤; 张扬; 王雨果; 张杨鑫; 冯娜娜; 蔡晋; 王志宁
Original assignee: Shanxi Research Institute for Clean Energy of Tsinghua University
Current assignee: Shanxi Research Institute for Clean Energy of Tsinghua University
Priority date: 2021-05-19
Filing date: 2021-05-19
Publication date: 2023-06-27
Anticipated expiration: 2041-05-19
Also published as: CN113339794A

Abstract

An embodiment of the present invention proposes a low nitrogen burner comprising: a housing having a receiving cavity; the air box plate is arranged in the accommodating cavity so as to divide the accommodating cavity into an air box cavity and a mounting cavity, the mounting cavity comprises a first opening, and the first opening and the air box plate are oppositely arranged in a first direction; a plurality of combustion tubes mounted on the fan case plate, the plurality of combustion tubes extending in a first direction; the flame spray head pipe comprises a first air pipe and a first gas pipe, the first air pipe and the first gas pipe extend along a first direction, the first air pipe is arranged on the air box plate, the first air pipe is sleeved on the first gas pipe, the first air pipe and the first gas pipe define a first air channel, and the first gas pipe comprises a straight section and a divergent section; and the ignition device is arranged on the fan box plate. Therefore, the low-nitrogen combustor provided by the embodiment of the invention has the advantages of high combustion stability and sufficient combustion.

Description

Low nitrogen burner

Technical Field

The invention relates to the field of combustors, in particular to a low-nitrogen combustor.

Background

The gas combustion device is widely used in the industrial field as an important heat energy conversion high-efficiency combustion device. The gas fuel mainly comprises natural gas, coal gas, desorption gas and the like, pollutants generated after combustion are mainly nitrogen oxides, and sulfur dioxide is also generated when the fuel contains sulfide. The formation of nitrogen oxides is closely related to the design of the burner. At present, the NOx emission requirements of the gas-fired boiler in China are becoming stricter, and the emission of nitrogen oxides is required to be not higher than 30mg/Nm3 (converted to the concentration of the discharged smoke O2 of 3.5%), which provides a new challenge for the combustion technology of the gas fuel.

In the prior art, particularly in the diffusion type combustion technology, the unstable phenomenon of combustion is easy to occur, even the flameout condition occurs, the emission of nitrogen oxides can not meet the existing standard, and the safety problem is easy to occur, and meanwhile, each combustion pipeline is required to be additionally provided with an air supply pipeline, so that the gas combustion device is arranged in a relatively messy way, and the installation is complicated.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems in the related art to some extent. To this end, embodiments of the present invention provide a low nitrogen combustor.

According to an embodiment of the present invention, a low nitrogen burner includes:

a housing having a receiving cavity;

the air box plate is arranged in the accommodating cavity so as to divide the accommodating cavity into an air box cavity and a mounting cavity, the mounting cavity comprises a first opening, and the first opening and the air box plate are oppositely arranged in a first direction;

a plurality of combustion pipes mounted on the fan case plate, the plurality of combustion pipes extending in the first direction;

the flame spray head pipe comprises a first air pipe and a first gas pipe, the first air pipe and the first gas pipe extend along the first direction, the first air pipe is installed on the air box plate, the first air pipe is sleeved on the first gas pipe, the first air pipe and the first gas pipe define a first air channel, the first gas pipe comprises a straight section and a divergent section, the divergent section is far away from the air box cavity relative to the straight section, the area of the cross section of the divergent section increases along the direction away from the air box cavity in the first direction, the area of the annular cross section between the divergent section and the first air pipe decreases along the direction away from the air box cavity in the first direction, and the divergent section is provided with an air inlet hole communicated with the first air channel; and

and the ignition device is adjacent to the flame spray nozzle pipe and is arranged on the fan box plate.

Therefore, the low-nitrogen combustor provided by the embodiment of the invention has the advantages of high combustion stability and sufficient combustion.

In some embodiments, each of the burner tubes includes a second gas tube and a second air tube, the second air tube being mounted on the air box plate, an outlet of the second air tube cooperating with an outlet of the second gas tube so that air within the second air tube mixes with gas within the second gas tube, each of the second gas tubes communicating with the first gas tube through a connecting tube.

In some embodiments, the second gas pipe is located in the installation cavity, the second gas pipe is sleeved on the second gas pipe, and an outlet of the second gas pipe extends out of the first opening.

In some embodiments, a porous medium is disposed within the second fuel pipe, the porous medium being adjacent to an outlet of the second air pipe.

In some embodiments, a plurality of rows of metal burning wires are arranged in the second gas pipe, the metal burning wires are staggered, and the metal burning wires are perpendicular to the section of the second gas pipe.

In some embodiments, the second gas pipe is located in the mounting cavity, and the second air pipe is sleeved on the second gas pipe.

In some embodiments, the air inlet holes are located in the middle of the diverging section in the first direction, and the plurality of air inlet holes are uniformly distributed along the circumferential direction of the diverging section.

In some embodiments, a sealing plate is disposed at an end of the first gas pipe adjacent to the diverging section, and a plurality of through holes penetrating the sealing plate along the first direction are formed in the sealing plate, and a plurality of through holes form an outlet of the first gas pipe.

In some embodiments, swirl vanes are provided on the outlet of the first air passage, the swirl vanes being remote from the bellows chamber relative to the inlet aperture.

In some embodiments, each of the burner tubes includes a second gas tube and a second air tube, the second air tube being mounted on the air box plate, an outlet of the second air tube cooperating with an outlet of the second gas tube such that air within the second air tube mixes with fuel within the second gas tube, each of a portion of the plurality of second gas tubes communicating with the first gas tube through a connecting tube, each of the remaining portion of the plurality of second gas tubes communicating with at least one of the plurality of second gas tubes through a connecting tube.

Drawings

FIG. 1 is a schematic view of a low nitrogen combustor according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a side view of a low nitrogen combustor in accordance with an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.

A low nitrogen burner 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings. As shown in fig. 1 and 2, the low nitrogen burner 100 according to the embodiment of the present invention includes a housing 10, a fan case plate 11, a plurality of burner pipes 20, a flame shower pipe 30, and an ignition device 40.

The housing 10 has a receiving chamber. The bellows plate 11 is provided in the housing chamber so as to divide the housing chamber into a bellows chamber 12 and a mounting chamber 13. The mounting cavity 13 comprises a first opening 14, the first opening 14 being arranged opposite the bellows plate 11 in a first direction. The first direction may be a left-right direction, as indicated by arrow a in fig. 1. For example, the first opening 14 is on the right side of the bellows plate 11.

A plurality of burner tubes 20 are mounted on the bellows plate 11, each burner tube 20 extending in a first direction. For example, each of the combustion tubes 20 extends in the left-right direction, and the injection direction of the combustion tube 20 is rightward.

The flame spray pipe 30 includes a first air pipe 31 and a first gas pipe 32, and the first air pipe 31 and the first gas pipe 32 extend in a first direction. For example, the first air pipe 31 and the first gas pipe 32 extend in the left-right direction. The first air pipe 31 is mounted on the air box plate 11, the first air pipe 31 is sleeved on the first gas pipe 32, the first air pipe 31 and the first gas pipe 32 define a first air passage 41, and an outlet of the first air passage 41 and an outlet of the first gas pipe 32 extend out of the mounting cavity 13 from the first opening 14. The inlet of the first air tube 31 opens into the bellows chamber 12, and air from the bellows chamber 12 enters the first air passage 41 to supply air required for combustion to the flame nozzle pipe 30.

The first gas pipe 32 comprises a straight section 33 and a diverging section 34, the diverging section 34 being remote from the windbox chamber 12 relative to the straight section 33. For example, the straight section 33 is located to the left of the diverging section 34, the outlet of the diverging section 34 constituting the outlet of the first gas pipe 32. The cross-sectional area of the diverging section 34 increases in a first direction in a direction away from the bellows chamber 12. For example, the diverging section 34 is a horn-shaped pipe section in the left-right direction, the left end of the diverging section 34 is connected to the straight section 33, and the right side of the diverging section 34 is an end with a larger caliber. The area of the cross-section of the diverging section 34 increases to the right, the space within the diverging section 34 increases to the right, and the pressure within the diverging section 34 decreases to the right. In contrast, the area of the annular cross section (the cross section of a portion of the first air passage 41) between the diverging section 34 and the first air tube 31 decreases in the first direction in a direction away from the bellows chamber 12. For example, the area of the annular cross section (the cross section of a portion of the first air passage 41) between the diverging section 34 and the first air tube 31 decreases rightward. The pressure of the space between the diverging section 34 and the first air tube 31 increases rightward. The outlet of the first air duct 31 and the diverging section 34 define an outlet of the first air passage 41, the area of the cross-section of the outlet of the first air passage 41 being the smallest of the areas of the cross-section of the first air passage 41.

The diverging section 34 is provided with an air inlet 35 communicating with the first air passage 41, so that the first air passage 41 communicates with the first gas pipe 32, i.e. the air inlet 35 can mix air and gas in the flame nozzle pipe 30. An ignition device 40 is mounted on the fan case plate 11 adjacent to the flame burner pipe 30, the ignition device 40 being used to ignite the partial combustion pipe 20 and the flame burner pipe 30.

The low nitrogen burner 100 according to the embodiment of the present invention is provided with the diverging section 34, and the diverging section 34 is provided with the air inlet hole 35 communicated with the first air passage 41, so that the first gas pipe 32 is communicated with the first air passage 41. The pressure in the diverging section 34 in the direction towards the outlet is reduced, and the pressure in the first air passage 41 in the direction towards the outlet is increased, so that a part of air in the first air passage 41 enters the diverging section 34 from the air inlet 35 to be mixed with the fuel gas in the diverging section 34 to obtain mixed gas, and the mixed gas in the diverging section 34 is sprayed out from the outlet of the diverging section 34 (the first fuel gas pipe 32) and is ignited by the ignition device 40. So that the flame spray head pipe 30 can ignite the plurality of combustion pipes 20, thereby enabling all the combustion pipes 20 in the low-nitrogen burner 100 to be ignited, and preventing the combustion pipes 20 from flameout and insufficient fuel combustion.

The remaining portion of the air in the first air passage 41 is ejected from the outlet of the first air passage 41. The area of the cross section of the outlet of the first air channel 41 is the smallest value of the area of the cross section of the first air channel 41, so that the air exiting from the outlet of the first air channel 41 can form an annular air flow with a certain distance at the outlet of the first air channel 41, the annular air flow rectifies the air exiting from the outlet of the first gas pipe 32, so that the annular air flow protects the mixed gas exiting from the outlet of the first gas pipe 32, and the gas exiting from the outlet of the first gas pipe 32 is not blown out or blown out in a certain distance from the air flow with other directions. The annular air flow prevents the flame spray pipe 30 from being blown out or askew within a certain distance, further ensuring the stability of the combustion of the low nitrogen burner 100.

Therefore, the low nitrogen burner 100 according to the embodiment of the present invention has the advantages of high combustion stability and sufficient combustion.

As shown in fig. 1, in some embodiments, each burner tube 20 includes a second gas tube 21 and a second air tube 22. A second air tube 22 is mounted to the bellows plate 11, and an inlet of the second air tube 22 communicates with the bellows chamber 12. The outlet of the second air pipe 22 cooperates with the outlet of the second gas pipe 21 so that the air in the second air pipe is mixed with the gas in the second gas pipe. The inlet of the first gas pipe 32 is connected to a gas supply pipe, and each of the second gas pipes 21 is communicated with the first gas pipe 32 through a connection pipe 37. Each second gas pipe 21 can be filled with the required gas through the connecting pipe 37 without being connected with a gas supply pipeline, so that the gas supply mode is more convenient, a plurality of gas supply pipelines are not required to be added, and the pipeline structure is simplified.

As shown in fig. 1, in some embodiments, the second gas pipe 21 is located in the installation cavity 13, and the second gas pipe 21 is sleeved on the second air pipe 22, so that space of the installation cavity 13 can be saved, and installation of the combustion pipe 20 is facilitated. The outlet of the second gas pipe 21 protrudes out of the first opening 14 to facilitate the diffusion and combustion of the mixed gas.

As shown in fig. 1, in some embodiments, the second gas pipe 21 is provided with a porous medium 23, the porous medium 23 is adjacent to the outlet of the second air pipe 22, and the gas in the second gas pipe 21 and the air in the second air pipe 22 enter the porous medium 23 to meet and can be uniformly mixed to obtain a mixed gas, so that the mixed gas exiting from the combustion pipe 20 is fully combusted.

As shown in fig. 1, in some embodiments, a plurality of rows of metal combustion wires 24 are provided in the second gas pipe 21, the plurality of rows of metal combustion wires 24 being staggered, the plurality of rows of metal combustion wires 24 being perpendicular to the cross section of the second gas pipe 21. The rows of wire mesh 24 are spaced apart from the outlet of the second air tube 22 with respect to the porous medium 23. The multiple row wire mesh 24 further increases the mixing effect of air and gas so that the mixed gas burns more sufficiently, and the mixed gas can burn on the surface of the multiple row wire mesh 24, reducing flashback.

In some embodiments, the second air pipe 22 is sleeved on the second gas pipe 21, so that space of the installation cavity 13 can be saved, and the installation of the combustion pipe 20 is facilitated. The outlet of the second air tube 22 protrudes from the first opening 14 into the mounting chamber 13 to facilitate the diffusion and combustion of the mixed gas.

In some embodiments, the air inlet holes 35 are located in the middle of the diverging section 34 in the first direction, and there are a plurality of air inlet holes 35, and a plurality of air inlet holes 35 are uniformly distributed along the circumference of the diverging section 34. So that the air in the first air passage 41 can enter the diverging section 34 more uniformly, facilitating the mixing of air and gas.

As shown in fig. 1 and 2, in some embodiments, a sealing plate 38 is disposed at an end of the first gas pipe 32 adjacent to the diverging section 34, and a plurality of through holes 39 extending therethrough in the first direction are disposed on the sealing plate 38, the plurality of through holes 39 forming an outlet of the first gas pipe 32. The sealing plate 38 may increase the discharge pressure at the outlet of the diverging section 34 to provide a greater flame throw distance from the first gas pipe 32 (flame burner pipe 30) to meet combustion needs.

As shown in fig. 1 and 2, in some embodiments, swirl vanes 36 are provided on the outlet of the first air passage 41, the swirl vanes 36 being remote from the bellows chamber 12 relative to the inlet holes 35. The swirl vanes 36 may cause the air exiting the outlet of the first air passage 41 to rotate, facilitating the formation of an annular air flow.

In some embodiments, each burner tube 20 includes a second gas tube 21 and a second air tube 22. A second air tube 22 is mounted to the bellows plate 11, and an inlet of the second air tube 22 communicates with the bellows chamber 12. The outlet of the second air pipe 22 cooperates with the outlet of the second gas pipe 21 so that the air in the second air pipe is mixed with the gas in the second gas pipe. Each of a portion of the plurality of second gas pipes 21 communicates with the first gas pipe 32 through a connection pipe 37. Each of the remaining portions of the plurality of second gas pipes 21 communicates with at least one of a portion of the plurality of second gas pipes 21 through a connection pipe 37. For example, the plurality of second gas pipes 21 are divided into a first group of gas pipes each of which communicates with the first gas pipe 32 through a connection pipe 37 and a second group of gas pipes each of which communicates with at least one of a portion of the first group of gas pipes through a connection pipe 37. Therefore, the combustion tube 20 does not need to be connected with a gas supply pipeline, the gas supply mode is more convenient, a plurality of gas supply pipelines do not need to be added, and the pipeline structure is simplified.

In some embodiments, the flame tip tube 30 is centrally located within the receiving cavity so that the flame tip tube 30 can uniformly ignite the plurality of combustion tubes 20, resulting in stable combustion of the low-nitrogen burner 100.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; may be mechanically connected, may be electrically connected or may be in communication with each other; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

For purposes of this disclosure, the terms "one embodiment," "some embodiments," "example," "a particular example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims

1. A low nitrogen combustor, comprising:

a housing having a receiving cavity;

the flame spray head pipe comprises a first air pipe and a first gas pipe, the first air pipe and the first gas pipe extend along the first direction, the first air pipe is installed on the bellows plate, the first air pipe is sleeved on the first gas pipe, the first air pipe and the first gas pipe define a first air channel, an outlet of the first air channel and an outlet of the first gas pipe extend out of a first opening to form an installation cavity, the first gas pipe comprises a flat section and a divergent section, the divergent section is far away from the bellows cavity relative to the flat section, the area of the cross section of the divergent section increases along the direction away from the bellows cavity in the first direction, the area of the annular cross section between the divergent section and the first air pipe decreases along the direction away from the bellows cavity in the first direction, and an air inlet hole communicated with the first air channel is formed in the divergent section; and

2. The low nitrogen burner of claim 1, wherein each of said burner tubes includes a second gas tube and a second air tube, said second air tube being mounted to said bellows plate, an outlet of said second air tube cooperating with an outlet of said second gas tube such that air within said second air tube mixes with gas within said second gas tube, each of said second gas tubes communicating with said first gas tube through a connecting tube.

3. The low nitrogen burner of claim 2, wherein the second gas tube is positioned within the mounting cavity, the second gas tube being sleeved on the second air tube, an outlet of the second gas tube extending out of the first opening.

4. A low nitrogen burner according to claim 3, wherein a porous medium is provided in said second gas pipe, said porous medium being adjacent to the outlet of said second air pipe.

5. The low nitrogen burner of claim 4, wherein a plurality of rows of metal combustion wire mesh are arranged in the second gas pipe, the plurality of rows of metal combustion wire mesh are arranged in a staggered manner, and the plurality of rows of metal combustion wire mesh are perpendicular to the section of the second gas pipe.

6. The low nitrogen burner of claim 2, wherein said second gas tube is positioned within said mounting cavity and said second air tube is sleeved on said second gas tube.

7. The low nitrogen burner of claim 1, wherein said inlet holes are located in the middle of said diverging section in said first direction, a plurality of said inlet holes being uniformly distributed along the circumference of said diverging section.

8. The low nitrogen burner of claim 1, wherein said first gas tube has a sealing plate adjacent one end of said diverging section, said sealing plate having a plurality of through holes therethrough in said first direction, a plurality of said through holes forming an outlet of said first gas tube.

9. The low nitrogen burner of claim 1, wherein swirl vanes are provided on the outlet of the first air passage, the swirl vanes being remote from the bellows chamber relative to the inlet aperture.

10. The low nitrogen burner of claim 1, wherein each of said burner tubes includes a second gas tube and a second air tube, said second air tube being mounted on said bellows plate, an outlet of said second air tube cooperating with an outlet of said second gas tube such that air within said second air tube mixes with gas within said second gas tube, each of a portion of a plurality of said second gas tubes communicating with said first gas tube through a connecting tube, each of the remaining portions of a plurality of said second gas tubes communicating with at least one of a plurality of said second gas tubes through a connecting tube.