CN109297018B

CN109297018B - Low nitrogen gas combustor

Info

Publication number: CN109297018B
Application number: CN201710607922.2A
Authority: CN
Inventors: 刘博�; 郑延庆; 曾天掌; 刘浪; 程博
Original assignee: Fuzhou Huaxia Blue Sky Information Technology Co ltd
Current assignee: Fuzhou Huaxia Blue Sky Information Technology Co ltd
Priority date: 2017-07-24
Filing date: 2017-07-24
Publication date: 2024-03-26
Anticipated expiration: 2037-07-24
Also published as: CN109297018A

Abstract

A low nitrogen gas burner comprises a cylinder, a swirl disk, a natural gas channel mechanism and a combustion air channel mechanism. The wall of the throat of the cylinder is provided with a plurality of smoke internal circulation holes. The natural gas channel mechanism comprises a plurality of peripheral pipelines, a plurality of transition area pipelines and a central pipeline, and the combustion air channel mechanism comprises a middle layer air channel and an outer layer air channel. Combustion air from the middle layer air channel is mixed with natural gas sprayed out from the central spray hole to form a central combustion area; part of combustion air from the outer air channel is mixed with natural gas sprayed out of the spray hole of the transition area pipeline to form a transition combustion area; the other part of combustion air from the outer air channel is mixed with natural gas sprayed out from the spray holes of the peripheral pipeline to form a peripheral combustion area; part of the burnt flue gas can enter the cylinder body through the flue gas internal circulation holes.

Description

Low nitrogen gas combustor

Technical Field

The invention relates to the technical field of clean combustion of natural gas, in particular to a self-contained smoke internal circulation type low NOx burner structure.

Background

NOx is an important component of atmospheric pollutants and is also one of the important factors in causing haze and acid rain. Along with the continuous improvement of environmental protection requirements at present, the limit on the emission amount of NOx is also becoming stricter,

natural gas burners are based on natural gas, which can reduce NOx emissions, and have been developed in recent years. The natural gas burner has the advantages of cleanness, high efficiency, safety, simplicity and convenience and the like.

Specifically, the natural gas burner achieves the aim of converting chemical energy into heat energy by mixing and burning natural gas and air. Through reasonable combustor structural design, can make natural gas and air misce bene, on the basis of guaranteeing high-efficient burning, reduce the production in local high temperature zone to inhibit the formation of NOx in the combustion process, reach low NOx's emission. For example, CN 105135432a adopts a structure of an inner and an outer fuel guns to adjust the distribution of fuel and air in the combustion area, reduce the formation of a high temperature area, and reduce the emission of NOx.

The mixing of the fuel and the air before entering the combustion zone has a great influence on the combustion effect, however, the mixing of the natural gas and the air sprayed by the fuel gun is limited in time and space before entering the combustion zone, which can lead to poor mixing effect of the natural gas and the air in the zone, uneven concentration and temperature distribution in the combustion zone and increased generation amount of NOx.

Therefore, there is still much room for improvement in NOx emissions from natural gas burners, and there are many technological means to reduce pollutant emissions yet to be developed. There remains a need for a more rational and efficient design of ultra low NOx emissions burner configurations to effectively reduce combustion and control pollutant emissions.

Disclosure of Invention

It is a primary object of the present invention to overcome at least one of the above-mentioned drawbacks of the prior art by providing a low nitrogen gas burner to solve the problem of poor mixing of natural gas and air in existing natural gas burners to organize combustion and reduce the generation and emission of pollutants.

In order to achieve the above object, the present invention provides a low nitrogen gas burner, which comprises a cylinder, a swirl disk, a natural gas channel mechanism and a combustion air channel mechanism.

One end of the cylinder body is provided with a throat, and the wall part of the throat is provided with a plurality of smoke internal circulation holes. The cyclone disc comprises a cyclone inner ring, a cyclone outer ring and cyclone blades, the cyclone disc is centrally positioned in the cylinder and is coaxial with the cylinder, and the cyclone blades are arranged between the cyclone inner ring and the cyclone outer ring.

The natural gas channel mechanism comprises a plurality of peripheral pipelines, a plurality of transition area pipelines and a central pipeline, wherein the peripheral pipelines are arranged around the cylinder body, and jet holes of the peripheral pipelines are positioned outside the cylinder body and close to the throat; the central pipeline penetrates through the rotational flow inner ring and comprises a central natural gas gun, a natural gas chamber and a central injection hole, the natural gas chamber is arranged at one end, close to the throat, of the central natural gas gun, and the central injection hole is communicated with the central natural gas gun through the natural gas chamber; a plurality of transition zone ducts are disposed about the central duct with one end of the transition zone ducts passing through the swirl vanes.

The combustion air passage means comprises a middle air passage and an outer air passage, the area between the central duct and the transition area duct being defined as the middle air passage and the area between the peripheral duct and the transition area duct being defined as the outer air passage.

Wherein, combustion air from the middle layer air channel is mixed with natural gas sprayed out from the central spray hole to form a central combustion area; part of combustion air from the outer air channel is mixed with natural gas sprayed out of the spray hole of the transition area pipeline to form a transition combustion area; the other part of combustion air from the outer air channel is mixed with natural gas sprayed out from the spray holes of the peripheral pipeline to form a peripheral combustion area; part of the burnt flue gas can enter the cylinder body through the flue gas internal circulation holes.

Compared with the prior art, the invention has the beneficial effects that: the low-nitrogen gas burner provided by the invention forms a high-efficiency and reliable combustion field at the downstream of the burner by the combined action of the inner and outer natural gas distribution modes, the corresponding two-layer combustion air distribution modes and the internal smoke circulation, and the natural gas is reasonably and uniformly distributed, so that the range of a local high-temperature area is effectively reduced by utilizing the internal smoke circulation holes, and the generation of NOx is inhibited.

Drawings

Various objects, features and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the invention, when taken in conjunction with the accompanying drawings. The drawings are merely exemplary illustrations of the invention and are not necessarily drawn to scale. In the drawings, like reference numerals refer to the same or similar parts throughout. Wherein:

fig. 1 is a schematic structural view of the low nitrogen gas burner of the present invention.

Fig. 2 is a perspective cross-sectional view of the low nitrogen gas burner of the present invention.

Fig. 3 is an enlarged view of a portion of fig. 1, showing the internal circulation path of the flue gas.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus detailed descriptions thereof will be omitted.

Relative terms, such as "lower" or "bottom" and "upper" or "top," may be used in embodiments to describe the relative relationship of one component of an icon to another component. It will be appreciated that if the device of the icon is flipped upside down, the components recited on the "lower" side will become components on the "upper" side. In addition, when a layer is "on" another layer or substrate, it may mean "directly on" the other layer or substrate, or on the other layer or substrate, or sandwiching the other layer between the other layers or substrates.

The invention provides a low nitrogen gas burner which can be a boiler or any one of a combustion device. As shown in fig. 1 to 3, the low nitrogen gas burner includes a cylinder 10, a swirl disk 20, a natural gas passage mechanism, and a combustion air passage mechanism.

One end of the cylinder 10 is provided with a throat 11, and a wall part 12 of the throat 11 is provided with a plurality of smoke internal circulation holes 13. The swirl disk 20 comprises a swirl inner ring 21, a swirl outer ring 22 and swirl vanes 23, the swirl disk 20 is centrally positioned in the cylinder 10 and is coaxial with the cylinder 10, and the swirl vanes 23 are arranged between the swirl inner ring 21 and the swirl outer ring 22.

The natural gas channel mechanism comprises a plurality of peripheral pipelines 31, a plurality of transition area pipelines 32 and a central pipeline 33, wherein the peripheral pipelines 31 are arranged around the cylinder 10, and jet holes 311 of the peripheral pipelines 31 are positioned outside the cylinder 10 and near the throat 11; the central pipeline 33 is arranged in the cyclone inner ring 21 in a penetrating way, the central pipeline 33 comprises a central natural gas gun 331, a natural gas chamber 332 and a central injection hole 333, the natural gas chamber 332 is arranged at one end of the central natural gas gun 331 close to the throat 11, and the central injection hole 333 is communicated with the central natural gas gun 331 through the natural gas chamber 332; a plurality of transition zone ducts 32 are disposed around the central duct 33 with one end of the transition zone duct 32 passing through the swirl vanes 23.

The combustion air passage means comprises a middle air passage 41 and an outer air passage 42, the area between the central duct 33 and the transition area duct 32 being defined as middle air passage 41, and the area between the peripheral duct 31 and the transition area duct 32 being defined as outer air passage 42.

Wherein the combustion air from the middle air passage 41 is mixed with the natural gas ejected from the central ejection hole 333 to form a central combustion area; part of the combustion air from the outer air passage 42 is mixed with natural gas ejected from the ejection holes 321 of the transition region duct 32 to form a transition combustion region; another part of the combustion air from the outer air passage 42 is mixed with the natural gas ejected from the ejection holes 311 of the peripheral duct 31 to form a peripheral combustion area; part of the high-temperature flue gas after combustion can enter the cylinder 10 through the flue gas inner circulation holes 13 and is sucked into the combustion air channel mechanism, so that the oxygen content of a combustion area is reduced, the local combustion temperature is reduced, and the shape and the range of flame downstream of the burner are controlled through higher air flow speed.

During operation of the low nitrogen gas burner, combustion air entering the cartridge 10 is split into two parts, entering the middle air passage 41 and the outer air passage 42, respectively. Wherein, the combustion air entering the middle layer air channel 41 forms strong swirl air through the action of the swirl disk 20, and natural gas sprayed by the concentric spray holes 333 is mixed to form a stable central combustion area; part of the combustion air entering the outer air passage 42 is mixed with the natural gas sprayed from the spraying holes 321 of the transition area pipeline 32 to form a middle transition combustion area; the natural gas jets ejected from the ejection holes 311 of the outermost peripheral duct 31 are uniformly distributed in the radial direction and mixed with another portion of combustion air from the outer air passage 42 to form a peripheral combustion zone.

Thus, the overall combustion zone is divided into a central combustion zone for fuel-rich combustion, a transitional combustion zone for fuel-lean combustion, and a peripheral combustion zone. Inhibiting NOx production by the localized rich fuel; the transitional combustion zone and the peripheral combustion zone are lean premixed gases, the combustion temperature is low, and the effect of reducing NOx emission is achieved.

In addition, as the smoke internal circulation hole 13 is formed at the throat 11, the pressure outside the hole is larger than the pressure in the hole, so that external smoke can be sucked into the cylinder 10, the smoke can enter a combustion area, the local temperature of combustion is reduced, and the thick-thin combustion is realized. The effect of reducing NOx emissions is achieved by controlling the shape and extent of the flame downstream of the burner with a higher gas flow rate.

In this embodiment, the barrel 10 includes a body 14, the body 14 is connected with the wall 12 of the throat 11, the wall 12 of the throat 11 is retracted toward the barrel 10 compared with the body 14, and the peripheral pipe 31 is disposed through the body 14, so that a part of the peripheral pipe 31 is located inside the barrel 10, and another part is located outside the barrel 10. Wherein one end of the peripheral pipe 31 provided with the injection holes 311 is inclined toward the inside of the cylinder 10, thereby injecting natural gas to the cylinder 10 to be rapidly and uniformly mixed with the natural gas.

In this embodiment, the barrel 10 further includes a guide plate 15 which is attached to the outer edge of the wall portion 12 of the throat 11 and expands obliquely toward the outside of the barrel 10. Wherein the angle of inclination of the guide plate 15 may range from 20 deg. -45 deg.. As shown in fig. 3, the flared wall 12 makes the throat 11 bell-mouthed, part of the flue gas is sucked in the cylinder after being discharged, part of the flue gas enters the transitional combustion zone in the cylinder through the flue gas inner circulation hole 13, and part of the flue gas is guided to the peripheral pipeline 31 by the guide plate 15 and enters the peripheral combustion zone. Therefore, the guide plate 15 and the smoke internal circulation holes 13 are matched, so that the smoke internal circulation can be formed, the range of a local high-temperature area is effectively reduced, and the generation of NOx is inhibited.

In this embodiment, the natural gas channel mechanism further includes a plurality of L-shaped branch pipes 34, which includes an axial tube 341 and a radial tube 342 connected perpendicularly to each other, the axial tube 341 surrounds the outer circumference of the cylinder 10, the radial tube 342 extends into the cylinder 10 through the flue gas inner circulation hole 13, the projection of the radial tube 342 along the axial direction is at least partially located within the projection range of the swirl disk 20, and one end of the radial tube 342 extending into the cylinder 10 has a radial injection hole 343.

Wherein the outer circumference of the radial pipe 342 extending into the cylinder 10 is provided with a plurality of circumferential injection holes 344, which are mixed with the combustion air from the middle air passage 41 and the natural gas injected from the central injection holes 333 to form the central combustion zone.

Wherein, the projection of at least one circumferential injection hole 344 along the axial direction is located in the projection range of the swirl disk 20, and is mixed with the combustion air from the middle layer air channel 41 and the natural gas injected from the central injection hole 333 to form the central combustion area; at least one circumferential injection hole 344 is located in the outer air passage 42 that mixes with a portion of the combustion air from the outer air passage 42 and natural gas injected from the injection holes 321 of the transition zone duct 32 to form a transition combustion zone.

Accordingly, the combustion air is divided into two stages and the natural gas is divided into three stages by the natural gas passage means and the combustion air passage means. Natural gas can be injected into the center through the center pipe 33, and simultaneously, the radial injection holes 343 of the L-shaped branch pipes 34 can inject the natural gas above the swirl disk 20, and one end of the transition region pipe 32 passing through the swirl vanes 23 is inclined toward the inside of the cylinder, so that the natural gas is also injected above the swirl disk 20, and three natural gas are mixed with the swirl combustion air. The outer layer fuel is directly injected into the outer layer combustion air, so that the reasonable speed distribution at the outlet of the burner and the uniform mixing of the fuel gas and the combustion air are ensured, the combusted flue gas enters the combustion area through the flue gas internal circulation, and the combustion area is reasonably controlled, thereby ensuring the combustion stability and the good NOx emission reduction effect.

In this embodiment, the L-shaped branch pipes 34 are equally spaced around the cylinder 10, and the same number of peripheral pipes 31 are provided between adjacent L-shaped branch pipes 34, and the extension line of the radial pipe 342 of each L-shaped branch pipe 34 passes through the axis of the cylinder 10. The number of the circulating holes 13 in the flue gas is 6-12, the number of the peripheral pipelines 31 is 6-24, and each 5 peripheral pipelines 31 are arranged with an L-shaped branch pipe 34.

In this embodiment, the angle of the swirl vanes 23 may be 25 ° -60 °, and the number of swirl vanes 23 may be 6-12.

In summary, the low-nitrogen gas burner of the invention forms a high-efficiency and reliable combustion field at the downstream of the burner by the combined action of the inner and outer natural gas distribution modes, the corresponding two-layer combustion air distribution modes and the internal smoke circulation, and the natural gas is reasonably and uniformly distributed, so that the range of a local high-temperature area is effectively reduced by using the internal smoke circulation holes 13, and the generation of NOx is inhibited.

While the invention has been described with reference to several exemplary embodiments, it is to be understood that the terminology used is intended to be in the nature of words of description and of limitation. As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the meets and bounds of the claims, or equivalences of such meets and bounds are therefore intended to be embraced by the appended claims.

Claims

1. A low nitrogen gas burner comprising:

one end of the cylinder is provided with a throat, and the wall part of the throat is provided with a plurality of smoke internal circulation holes;

the cyclone disc comprises a cyclone inner ring, a cyclone outer ring and cyclone blades, the cyclone disc is centrally positioned in the cylinder and is coaxial with the cylinder, and the cyclone blades are arranged between the cyclone inner ring and the cyclone outer ring;

the natural gas channel mechanism comprises a plurality of peripheral pipelines, a plurality of transition area pipelines and a central pipeline, wherein the peripheral pipelines are arranged around the cylinder body, and jet holes of the peripheral pipelines are positioned outside the cylinder body and close to the throat; the central pipeline penetrates through the rotational flow inner ring and comprises a central natural gas gun, a natural gas chamber and a central injection hole, the natural gas chamber is arranged at one end, close to the throat, of the central natural gas gun, and the central injection hole is communicated with the central natural gas gun through the natural gas chamber; the plurality of transition area pipelines are arranged around the central pipeline, and one end of each transition area pipeline passes through the cyclone blade; and

The combustion air channel mechanism comprises a middle layer air channel and an outer layer air channel, wherein the area between the central pipeline and the transition area pipeline is defined as a middle layer air channel, and the area between the peripheral pipeline and the transition area pipeline is defined as an outer layer air channel;

2. The low nitrogen gas burner of claim 1, wherein the barrel includes a body connected to a wall of the throat, the wall of the throat being inwardly retracted toward the barrel as compared to the body, the peripheral conduit passing through the body such that a portion of the peripheral conduit is located within the barrel.

3. The low nitrogen gas burner of claim 2, wherein the barrel further comprises a deflector connected to an outer edge of the wall of the throat and expanding obliquely toward the outside of the barrel.

4. A low nitrogen gas burner as recited in claim 3 wherein the deflector has an inclination angle in the range of 20 ° -45 °.

5. The low nitrogen gas burner of claim 1, wherein the natural gas channeling means further comprises a plurality of L-shaped branch pipes including an axial pipe and a radial pipe connected to each other perpendicularly, the axial pipe surrounding the outer circumference of the cylinder, the radial pipe extending into the inside of the cylinder through the flue gas inner circulation hole, and a projection of the radial pipe in the axial direction being at least partially within a projection range of the swirl disk, an end of the radial pipe extending into the inside of the cylinder having a radial injection hole.

6. The low nitrogen gas burner of claim 5, wherein the outer circumference of the radial tube extending into the cylinder is provided with a plurality of circumferential injection holes which are mixed with combustion air from the middle air passage and natural gas injected from the central injection holes to form the central combustion zone.

7. The low nitrogen gas burner of claim 6, wherein the projection of the at least one circumferential jet hole in the axial direction is within the projection of the swirl disk, which mixes with combustion air from the middle air passage and natural gas ejected from the central jet hole to form the central combustion zone; at least one circumferential jet orifice is located in the outer air passage and is mixed with a portion of combustion air from the outer air passage and natural gas from the jet orifice of the transition zone duct to form a transition combustion zone.

8. The low nitrogen gas burner of claim 5, wherein the L-shaped branch pipes are equally spaced around the barrel with the same number of peripheral tubes between adjacent L-shaped branch pipes, the extension of the radial tube of each L-shaped branch pipe passing through the axis of the barrel.

9. The low nitrogen gas burner of claim 1, wherein the number of circulation holes in the flue gas is 6-12 and the number of peripheral pipes is 6-24.

10. The low nitrogen gas burner of claim 1, wherein an end of the peripheral pipe provided with the injection hole is inclined toward the inside of the cylinder.

11. The low nitrogen gas burner of claim 1 wherein the end of the transition zone conduit passing through the swirl vanes is inclined toward the interior of the barrel.

12. The low nitrogen gas burner of claim 1, wherein the angle of the swirl vanes is 25 ° -60 °, the number of swirl vanes being 6-12.