CN113339794A

CN113339794A - Low-nitrogen burner

Info

Publication number: CN113339794A
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: 2021-09-03
Anticipated expiration: 2041-05-19
Also published as: CN113339794B

Abstract

An embodiment of the present invention provides a low-nitrogen combustor including: a housing having an accommodating chamber; the air box plate is arranged in the containing cavity so as to divide the containing 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 header plate, the plurality of combustion pipes extending in a first direction; the flame nozzle 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 mounted 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 gradually-expanding section; and the ignition device is arranged on the wind box plate. Therefore, the low-nitrogen combustor has the advantages of being high in combustion stability and sufficient in 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, gas condensate and the like, pollutants generated after combustion are mainly nitrogen oxides, and sulfur dioxide is also generated when the fuel contains sulfur compounds. The formation of nitrogen oxides is closely related to the design of the combustor. At present, the NOx emission requirement of gas boilers in China is increasingly strict, and the nitrogen oxide emission is mostly required to be not higher than 30mg/Nm3 (converted to the concentration of 3.5 percent of exhaust gas O2), which provides a new challenge for the combustion technology of gas fuels.

Among the prior art, especially diffusion formula combustion technology, the unstable phenomenon of burning easily appears, appears flameout condition even and appears, and nitrogen oxide discharges and can not satisfy current standard, and the safety problem easily appears, and simultaneously, every burning pipeline need set up the gas supply line in addition to it is comparatively mixed and disorderly to arrange cloth in the feasible gas combustion device, and the installation is loaded down with trivial details.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the technical problems in the related art. To this end, embodiments of the present invention propose a low-nitrogen burner.

The low-nitrogen combustor comprises the following components:

a housing having a receiving cavity;

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

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

the flame nozzle 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, a first air channel is defined by the first air pipe and the first gas pipe, the first gas pipe comprises a straight section and a gradually-expanding section, the gradually-expanding section is far away from the air box cavity relative to the straight section, the area of the cross section of the gradually-expanding section is increased along the direction far away from the air box cavity in the first direction, the area of the annular cross section between the gradually-expanding section and the first air pipe is decreased along the direction far away from the air box cavity in the first direction, and an air inlet communicated with the first air channel is formed in the gradually-expanding section; and

an ignition device adjacent to the flame burner tube, the ignition device mounted on the windbox plate.

Therefore, the low-nitrogen combustor has the advantages of being high in combustion stability and sufficient in combustion.

In some embodiments, each of the combustion tubes includes a second fuel 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 fuel gas tube so that air in the second air tube is mixed with fuel gas in the second fuel gas tube, each of the second fuel gas tubes communicating with the first fuel gas tube through a connection tube.

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

In some embodiments, a porous media is disposed within the second fuel tube adjacent the outlet of the second air tube.

In some embodiments, the second gas pipe is provided with a plurality of rows of metal combustion meshes, the plurality of rows of metal combustion meshes are staggered, and the plurality of rows of metal combustion meshes are perpendicular to the cross section of the second gas pipe.

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

In some embodiments, the air inlet hole is located in the middle of the divergent section in the first direction, the air inlet hole is multiple, and the air inlet holes are uniformly distributed along the circumferential direction of the divergent section.

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

In some embodiments, a swirl vane is disposed on an outlet of the first air passage, the swirl vane being remote from the bellows chamber relative to the air inlet.

In some embodiments, each of the combustion pipes includes a second gas pipe and a second air pipe, the second air pipe being mounted on the air box plate, an outlet of the second air pipe cooperating with an outlet of the second gas pipe so that air in the second air pipe is mixed with gas in the second gas pipe, each of a portion of the plurality of second gas pipes communicating with the first gas pipe through a connection pipe, and each of remaining portions of the plurality of second gas pipes communicating with at least one of the portion of the plurality of second gas pipes through a connection pipe.

Drawings

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

FIG. 2 is a schematic illustration of a side view of a low-nitrogen burner in accordance with an embodiment of the 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 with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

A low-nitrogen combustor 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 combustor 100 according to the embodiment of the present invention includes a case 10, a windbox plate 11, a plurality of combustion pipes 20, a flame spray pipe 30, and an ignition device 40.

The housing 10 has a receiving cavity. The bellows plate 11 is provided in the accommodation chamber so as to divide the accommodation chamber into a bellows chamber 12 and a mounting chamber 13. The mounting chamber 13 includes a first opening 14, and the first opening 14 is disposed opposite to the wind box plate 11 in the 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 windbox plate 11, each burner tube 20 extending in a first direction. For example, each of the combustion pipes 20 extends in the left-right direction, and the injection direction of the combustion pipe 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 installed on the air box plate 11, the first air pipe 31 is sleeved on the first fuel gas pipe 32, the first air pipe 31 and the first fuel gas pipe 32 define a first air channel 41, and an outlet of the first air channel 41 and an outlet of the first fuel gas pipe 32 extend out of the installation 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 spray tube 30.

The first gas pipe 32 includes a straight section 33 and a diverging section 34, the diverging section 34 being remote from the bellows chamber 12 relative to the straight section 33. For example, the straight section 33 is located on the left side of the diverging section 34, and the outlet of the diverging section 34 constitutes the outlet of the first gas pipe 32. The cross-sectional area of the diverging section 34 increases in a first direction away from the bellows chamber 12. For example, the divergent section 34 is a flared pipe section extending in the left-right direction, the left end of the divergent section 34 is connected to the straight section 33, and the right side of the divergent section 34 is a larger diameter end. The cross-sectional area of the diverging section 34 increases rightward, the space within the diverging section 34 increases rightward, and the pressure within the diverging section 34 decreases rightward. In contrast, the area of the annular cross section (cross section of a portion of the first air passage 41) between the divergent 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 part of the first air passage 41) between the divergent section 34 and the first air pipe 31 decreases rightward. The pressure of the space between the divergent section 34 and the first air pipe 31 increases rightward. The outlet of the first air duct 31 and the diverging section 34 define the outlet of the first air passage 41, and the area of the cross section of the outlet of the first air passage 41 is the minimum of the area of the cross section of the first air passage 41.

The divergent section 34 is provided with an air inlet hole 35 communicated with the first air passage 41, so that the first air passage 41 is communicated with the first gas pipe 32, that is, the air inlet hole 35 can mix the air and the gas in the flame spray nozzle pipe 30. The ignition device 40 is adjacent to the flame spray tube 30, the ignition device 40 is mounted on the windbox plate 11, and the ignition device 40 is used for igniting the partial combustion tube 20 and the flame spray tube 30.

The low-nitrogen burner 100 according to the embodiment of the invention enables the first gas pipe 32 to communicate with the first air passage 41 by providing the divergent section 34, and providing the intake port 35 communicating with the first air passage 41 on the divergent section 34. The pressure in the divergent section 34 in the direction toward the outlet is reduced, and the pressure in the direction toward the outlet of the first air passage 41 is increased, so that a part of air in the first air passage 41 enters the divergent section 34 from the air inlet hole 35 to be mixed with the gas in the divergent section 34 to obtain a mixed gas, and the mixed gas in the divergent section 34 is ejected from the outlet of the divergent section 34 (the first gas pipe 32) and then is ignited by the ignition device 40. So that the flame nozzle tube 30 can ignite a plurality of the combustion tubes 20, and thus all the combustion tubes 20 in the low-nitrogen burner 100 can be ignited, thereby preventing the occurrence of flameout of the combustion tubes 20 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 minimum value of the area of the cross section of the first air channel 41, therefore, the air coming out of the outlet of the first air channel 41 can form a certain distance of annular airflow at the outlet of the first air channel 41, and the annular airflow rectifies the air at the outlet of the first gas pipe 32, so that the annular airflow protects the mixed gas coming out of the outlet of the first gas pipe 32, and the gas coming out of the outlet of the first gas pipe 32 is blown out or askew without being influenced by airflows in other directions within a certain distance. The annular airflow prevents the flame nozzle pipe 30 from being blown out or tilted within a certain distance, further ensuring the combustion stability of the low-nitrogen burner 100.

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

As shown in FIG. 1, in some embodiments, each combustion tube 20 includes a second fuel tube 21 and a second air tube 22. A second air tube 22 is mounted on the windbox plate 11, the inlet of the second air tube 22 communicating with the windbox chamber 12. The outlet of the second air pipe 22 is fitted 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 connected with a 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 the space of the installation cavity 13 can be saved, and the installation of the combustion pipe 20 can be facilitated. The outlet of the second gas pipe 21 extends out of the first opening 14 to facilitate the diffusion and combustion of the mixed gas.

As shown in fig. 1, in some embodiments, a porous medium 23 is disposed in the second fuel pipe 21, the porous medium 23 is adjacent to the outlet of the second air pipe 22, and the fuel gas in the second fuel 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 coming out of the combustion pipe 20 can be sufficiently combusted.

As shown in fig. 1, in some embodiments, a plurality of rows of the metal combustion meshes 24 are provided in the second gas pipe 21, the plurality of rows of the metal combustion meshes 24 are staggered, and the plurality of rows of the metal combustion meshes 24 are perpendicular to the cross section of the second gas pipe 21. Multiple rows of wire mesh screens 24 are spaced from the outlet of the second air tube 22 relative to the porous media 23. The multi-row metal combustion wire nets 24 further increase the mixing effect of air and fuel gas, so that the mixed gas is more fully combusted, and the mixed gas can be combusted on the surfaces of the multi-row metal combustion wire nets 24, and the backfire is reduced.

In some embodiments, the second air pipe 22 is sleeved on the second fuel pipe 21, so that the 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 extends from the first opening 14 out of the mounting chamber 13 to facilitate 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 the air inlet holes 35 are multiple, and the multiple 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 divergent section 34 more uniformly, and the mixing of the air and the gas is facilitated.

As shown in fig. 1 and 2, in some embodiments, an end of the first gas pipe 32 adjacent to the diverging section 34 is provided with a closing plate 38, the closing plate 38 is provided with a plurality of through holes 39 extending therethrough in the first direction, and the plurality of through holes 39 constitute an outlet of the first gas pipe 32. The closing plate 38 increases the ejection pressure at the outlet of the diverging section 34, so that the flame ejection distance of the first gas pipe 32 (flame nozzle pipe 30) is longer to meet the combustion requirement.

As shown in fig. 1 and 2, in some embodiments, the outlet of the first air passage 41 is provided with a swirl vane 36, and the swirl vane 36 is away from the bellows chamber 12 with respect to the air intake hole 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 combustion tube 20 includes a second fuel tube 21 and a second air tube 22. A second air tube 22 is mounted on the windbox plate 11, the inlet of the second air tube 22 communicating with the windbox chamber 12. The outlet of the second air pipe 22 is fitted 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 part 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 is communicated 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 part of the first group of gas pipes through the connection pipe 37. Therefore, the combustion pipe 20 is not required to be connected with a gas supply pipeline, 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.

In some embodiments, the flame spray tube 30 is located at the center of the receiving cavity, so that the flame spray tube 30 can uniformly ignite the plurality of combustion tubes 20, and the low-nitrogen burner 100 can be stable in combustion.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.

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

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; may be mechanically coupled, may be electrically coupled or may be in communication with each other; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the present disclosure, the terms "one embodiment," "some embodiments," "an example," "a specific example," or "some examples" and the like mean that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the terms used above are not necessarily intended to refer 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, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A low-nitrogen burner, comprising:

a housing having a receiving cavity;

2. The low-nitrogen burner of claim 1, wherein each of the combustion tubes includes a second fuel 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 fuel gas tube so that air in the second air tube is mixed with fuel gas in the second fuel gas tube, each of the second fuel gas tubes communicating with the first fuel gas tube through a connection tube.

3. The low-nitrogen burner of claim 2, wherein the second fuel pipe is located in the mounting cavity, the second fuel pipe is sleeved on the second air pipe, and an outlet of the second fuel pipe extends out of the first opening.

4. The low-nitrogen burner of claim 3, wherein a porous medium is provided in the second fuel pipe, the porous medium being adjacent to the outlet of the second air pipe.

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

6. The low-nitrogen burner of claim 2, wherein the second fuel pipe is located in the mounting cavity, and the second air pipe is sleeved on the second fuel pipe.

7. The low-nitrogen burner of claim 1, wherein the air inlet hole is located in the middle of the divergent section in the first direction, and the air inlet hole is provided in plurality, and the plurality of air inlet holes are uniformly distributed along the circumferential direction of the divergent section.

8. The low-nitrogen burner of claim 1, wherein a sealing plate is provided at an end of the first gas pipe adjacent to the diverging section, the sealing plate having a plurality of through holes extending therethrough in the first direction, the plurality of through holes constituting outlets of the first gas pipe.

9. The low-nitrogen burner of claim 1, wherein a swirl vane is provided on an outlet of the first air passage, the swirl vane being distant from the bellows chamber with respect to the intake hole.

10. The low-nitrogen burner of claim 1, wherein each of the combustion tubes includes a second fuel 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 fuel gas tube so that air in the second air tube is mixed with gas in the second fuel gas tube, each of a portion of the plurality of second fuel gas tubes communicating with the first fuel gas tube through a connection tube, each of remaining portions of the plurality of second fuel gas tubes communicating with at least one of the portion of the plurality of second fuel gas tubes through a connection tube.