CN115143463A - Hierarchical flue gas inner loop low NOx burner - Google Patents

Hierarchical flue gas inner loop low NOx burner Download PDF

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Publication number
CN115143463A
CN115143463A CN202210801813.5A CN202210801813A CN115143463A CN 115143463 A CN115143463 A CN 115143463A CN 202210801813 A CN202210801813 A CN 202210801813A CN 115143463 A CN115143463 A CN 115143463A
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CN
China
Prior art keywords
gas
air
peripheral
branch pipe
flue gas
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Pending
Application number
CN202210801813.5A
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Chinese (zh)
Inventor
刘永才
王绥德
张龙
黄世峰
高鲁斌
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Shenzhen Jiayuntong Electronics Co Ltd
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Shenzhen Jiayuntong Electronics Co Ltd
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Priority to CN202210801813.5A priority Critical patent/CN115143463A/en
Publication of CN115143463A publication Critical patent/CN115143463A/en
Pending legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
    • F23D14/04—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner
    • F23D14/08—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone induction type, e.g. Bunsen burner with axial outlets at the burner head
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/26—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid with provision for a retention flame
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/48—Nozzles
    • F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/62—Mixing devices; Mixing tubes
    • F23D14/64—Mixing devices; Mixing tubes with injectors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/70—Baffles or like flow-disturbing devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
    • F23D14/78—Cooling burner parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
    • F23D14/82—Preventing flashback or blowback
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/007—Mixing tubes, air supply regulation

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)

Abstract

The invention relates to the technical field of low-nitrogen burners, in particular to a graded flue gas internal circulation low-nitrogen burner which comprises a peripheral air pipe and a main fuel gas pipeline; the peripheral air pipe is sleeved outside the main gas pipeline and is coaxially arranged with the main gas pipeline; the peripheral air tube comprises an air tube contraction port arranged at the end part; and an air injection section is sleeved at the downstream of the peripheral air pipe. According to the invention, the peripheral branch pipe gas side spray holes, the oblique gas branch pipe body and the swirl vanes are arranged, so that the mixing of air and gas is enhanced, the mixing is more uniform, the combustion efficiency is improved, and the thermal efficiency of the boiler is increased. Through being provided with slant gas branch pipe body and whirl blade, the stability of flame has been ensured to the stable flame of spiral-flow type to guaranteed the reliable and stable work of combustor, reduced the danger of tempering, improved the security in the combustor use.

Description

Hierarchical flue gas inner loop low NOx burner
Technical Field
The invention relates to the technical field of low-nitrogen combustors, in particular to a graded flue gas internal circulation low-nitrogen combustor.
Background
During the operation of the heating furnace, a large amount of flue gas emission is generated, wherein NOx, CO and the like bring atmospheric pollution, and the flue gas has adverse effects on the environment and the human health and influences the sustainable development of the society. The emission limit of pollutants in the flue gas is becoming stricter at home and abroad. No matter the strict restriction of national policy or the harm caused by air pollution, a burner with more energy-saving and environment-friendly design is needed to solve the contradiction between development and environment protection.
The authorization notice number is CN211575107U, multiple gas classification inside and outside is adopted, peripheral gas and air are premixed, the structure is favorable for reducing NOx, but the structure is complex, and peripheral premixed flame is difficult to control. Thus, there remains a need for a more rational and efficient staged, flue gas internal circulation combustion, low NOx burner configuration to organize combustion and control pollutant emissions.
In the low NOx technology of the combustor, the risk of backfire explosion and difficulty in control exists in premixed combustion, and energy is not enough saved; the external circulation of the flue gas also has the factors of unstable flame and increased cost, which is not favorable for the long-term stable operation of the heating furnace. Therefore, the technology of staged combustion, flue gas internal circulation and the like is adopted, and the method is a more reasonable technical means.
Disclosure of Invention
The invention aims to provide a graded flue gas internal circulation low-nitrogen combustor, which aims to solve the problems that in the low-NOx technology of the combustor proposed in the background technology, the premixed combustion has the dangers of backfire explosion and difficulty in control and is not enough in energy conservation; the flue gas external circulation also has the factors of unstable flame and increased cost, which is not favorable for the long-term stable operation of the heating furnace.
In order to achieve the purpose, the invention provides the following technical scheme: a classified flue gas internal circulation low-nitrogen combustor comprises a peripheral air pipe and a main fuel gas pipeline; the peripheral air pipe is sleeved outside the main gas pipeline and is coaxially arranged with the main gas pipeline; the peripheral air tube comprises an air tube contraction port arranged at the end part; an air injection section is sleeved at the downstream of the peripheral air pipe; the air injection section is provided with an air expansion port;
the gas pipeline comprises a main gas pipeline and an air splitter, wherein the main gas pipeline is sequentially provided with peripheral gas branch pipes which are uniformly installed, the main gas pipeline is sequentially provided with oblique gas branch pipes which are uniformly installed, the end part of the main gas pipeline is uniformly provided with radial jet holes, the contraction port of the air pipe contraction port is not sealed, and a channel exists between the air pipe contraction port and the air splitter.
Preferably, a coaxially arranged air splitter is arranged between the peripheral air pipe and the main gas pipeline; and a flame stabilizing disc is arranged at the end part of the air splitter, is positioned between the inclined gas branch pipe body and the radial jet hole, and is provided with a swirl vane and an inclined gas branch pipe hole.
Preferably, the inclined gas branch pipe hole is a gas outlet of the inclined gas branch pipe body;
preferably, a peripheral gas branch pipe is annularly arranged on one side of the main gas pipeline, one end of the peripheral gas branch pipe penetrates through the air expansion port, the penetrating part of the end of the peripheral gas branch pipe bends towards the central shaft, peripheral branch pipe gas side spray holes are distributed in the center of the end part of the peripheral gas branch pipe, and peripheral branch pipe center gas spray holes are formed in the center of the end part of the peripheral gas branch pipe.
Preferably, the peripheral gas branch pipe and the oblique gas branch pipe body are arranged in a crossed mode.
Preferably, the number of the swirl vanes is 4 to 10.
Preferably, the swirl angle of the swirl vanes is 20 to 60 °.
Preferably, the number of radial injection holes is 4 to 12.
Preferably, the gas ventilation area of the gas side spray holes of the peripheral branch pipe accounts for 70-90%.
Compared with the prior art, the invention has the beneficial effects that:
1. through being provided with peripheral branch pipe gas side orifice, slant gas branch pipe body and whirl blade, strengthen the mixture of air and gas, make the mixture more even, improve combustion efficiency, increase boiler thermal efficiency. By arranging the oblique gas branch pipe body and the rotational flow blades, the rotational flow type stable flame ensures the stability of the flame, thereby ensuring the reliable and stable work of the burner, reducing the risk of tempering and improving the safety of the burner in the use process; the length of flame is reduced, and the flame is prevented from scouring the bottom plate of the boiler. Through the mutual shearing and flame transfer effect between whirl effect and the multistage flame region, make the burning of gas mixture more stable, adopt the flue gas inner loop, further reduce nitrogen oxide and discharge.
2. Through being provided with the air expansion mouth, peripheral air forms the entrainment effect behind the air expansion mouth through, makes the flue gas of low reaches draw the mouth to get into the combustor once more from air pipe shrinkage mouth and air draw and draw between the section and draw and participate in and mix and the burning, because the shrink effect of air pipe shrinkage mouth, the increase of air flow rate has formed the negative pressure and has drawn the effect of penetrating, and the backward flow effect of flue gas is more obvious, because cooling, the inhibiting action of flue gas make combustion flame temperature drop, has reduced nitrogen oxide's formation.
Drawings
FIG. 1 is an exploded perspective view of the present invention;
FIG. 2 is a schematic perspective view of the present invention;
FIG. 3 is a partial cross-sectional structural schematic of the present invention;
fig. 4 is a schematic top view of the present invention.
In the figure: 110-peripheral air pipe, 120-main gas pipeline, 121-radial spray holes, 122-oblique gas branch pipe body, 123-swirl vanes, 124-flame stabilizing disc, 125-oblique gas branch pipe hole, 130-air pipe contraction hole, 140-air injection section, 150-air expansion hole, 160-peripheral gas branch pipe, 161-peripheral branch pipe central gas spray holes, 162-peripheral branch pipe gas side spray holes and 170-air splitter.
Detailed Description
The invention will be further described with reference to the accompanying drawings, but the scope of the invention is not limited to the following.
Example one
Referring to fig. 1-4, an embodiment of the present invention is shown: a staged flue gas internal circulation low-nitrogen burner comprises a peripheral air pipe 110 and a main fuel gas pipeline 120; the peripheral air pipe 110 is sleeved outside the main gas pipeline 120 and is coaxially arranged with the main gas pipeline 120; the peripheral air tube 110 includes an end-mounted air tube constriction 130; an air injection section 140 is sleeved at the downstream of the peripheral air pipe 110; the air injection section 140 has an air expansion opening 150.
Further, peripheral gas branch pipes 160 which are uniformly installed are sequentially installed on the main gas pipeline 120, oblique gas branch pipe bodies 122 which are uniformly installed on the main gas pipeline 120, and radial injection holes 121 are uniformly formed in the end portion of the main gas pipeline 120; a coaxially arranged air splitter 170 is installed between the peripheral air pipe 110 and the main gas pipe 120; the constriction of the air duct constriction 130 is not closed, and a passage exists between the air duct constriction 130 and the air splitter 170; a flame stabilizing disc 124 is mounted at the end of the air splitter 170, the flame stabilizing disc 124 is positioned between the inclined gas branch pipe body 122 and the radial injection hole 121, and is provided with swirl vanes 123 and inclined gas branch pipe holes 125; the oblique gas manifold hole 125 is a gas outlet of the oblique gas manifold body 122; a peripheral gas branch pipe 160 is annularly arranged on one side of the main gas pipeline 120, one end of the peripheral gas branch pipe 160 penetrates through the air expansion port 150, the penetrating end of the peripheral gas branch pipe is bent towards the central axis and is distributed with peripheral branch pipe gas side spray holes 162, and the end center of the peripheral gas branch pipe 160 is provided with a peripheral branch pipe central gas spray hole 161; the peripheral gas branch pipe 160 and the oblique gas branch pipe body 122 are arranged in a cross manner; the peripheral air duct 110, the air splitter 170, is used for the passage of air therethrough to guide air to the boiler furnace, and the main gas duct 120 is used for the passage of gas into the burner to guide gas to the boiler furnace. The air enters the burner and is divided into two portions. One part of the air passes through the air splitter 170 and forms primary air after passing through the swirl blades 123 of the flame stabilizing disc 124; another portion of the air enters the air injection section 140 through the passage between the peripheral air tube 110 and the air splitter 170 and exits the burner at the passage between the air injection section 140 and the air splitter 170 to form secondary air. The gas enters the main gas duct 120 and is divided into three portions.
Furthermore, the gas ventilation area of the gas side spray holes 162 of the peripheral branch pipe accounts for 70-90%; because the gas side spray holes 162 of the peripheral branch pipe are provided with a plurality of rows of small holes, the mixing of gas and air is promoted, and the combustion is more sufficient.
Example two
Compared with the first embodiment, please refer to fig. 2, the number of the swirl vanes 123 is 4-10. Because the air flows through the swirl vanes 123 to generate a swirl effect and convolutes a part of secondary air, the air is excessive and is oxygen-enriched combustion, and in addition, because of the swirl entrainment effect, heat exchange is formed between the primary flame area and the secondary flame area, and the combustion stability is ensured.
Further, the swirl angle of the swirl vanes 123 is 20 ° to 60 °.
Further, the number of the radial injection holes 121 is 4 to 12.
The working principle is as follows: the peripheral air duct 110, the air splitter 170, is used for the passage of air therethrough to guide air to the boiler furnace, and the main gas duct 120 is used for the passage of gas into the burner to guide gas to the boiler furnace. The air enters the burner and is divided into two portions. One part of the air passes through the air splitter 170 and forms primary air after passing through the swirl blades 123 of the flame stabilizing disc 124; another portion of the air enters the air injection section 140 through the passage between the peripheral air tube 110 and the air splitter 170 and exits the burner at the passage between the air injection section 140 and the air splitter 170 to form secondary air. The fuel gas enters the main fuel gas duct 120 and is divided into three portions.
The first part of fuel gas is radially sprayed out through the radial spray holes 121, and is mixed with part of primary air and then is combusted near the central axis of the boiler hearth to form a primary flame area, the air amount of the primary flame area is small, and oxygen-deficient combustion is formed;
the second part of the fuel gas passes through the inclined fuel gas branch pipe body 122 and then is sprayed out from the inclined fuel gas branch pipe hole 125 in an inclined mode, the second part of the fuel gas is mixed with part of the primary air to form a secondary flame area, the air flows through the swirl vanes 123 to generate a swirl effect, and a part of the secondary air is convoluted, so that the air is excessive and is in oxygen-enriched combustion, and in addition, due to the swirl entrainment effect, heat exchange is formed between the primary flame area and the secondary flame area, and the combustion stability is ensured;
the third part of the fuel gas is sprayed out after passing through the peripheral branch pipe fuel gas side spray holes 162 behind the peripheral fuel gas branch pipe 160 and the peripheral branch pipe central fuel gas spray holes 161. The fuel gas sprayed from the central fuel gas spray holes 161 of the peripheral branch pipes is obliquely sprayed towards the central axis and is mixed with part of secondary air, the part of mixed gas is further mixed with the mixed gas in the secondary flame area in a cross way, a tertiary flame area is formed by the downstream development, and the part of the mixed gas is excessive in air and is oxygen-enriched combustion; the gas sprayed from the gas side spray holes 162 of the peripheral branch pipe is sprayed outwards and is mixed with part of the secondary air to form a four-stage combustion area at the outermost periphery, and the gas side spray holes 162 of the peripheral branch pipe are provided with a plurality of rows of small holes, so that the mixing of the gas and the air is promoted, and the combustion is more sufficient.
Peripheral air forms the entrainment effect after flowing through air expansion opening 150 for the flue gas of low reaches draws the mouth to get into the combustor again and participate in mixing and burning from the drawing mouth that forms between air pipe constriction 130 and the air section of drawing 140, because the shrink effect of air pipe constriction 130, air flow rate increase has formed the negative pressure and has drawn the effect of spouting, and the backward flow effect of flue gas is more obvious, because the cooling of flue gas, inhibiting action, make the combustion flame temperature drop, has reduced nitrogen oxide's formation.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims (9)

1. A classified flue gas internal circulation low-nitrogen combustor is characterized by comprising a peripheral air pipe (110) and a main fuel gas pipeline (120); the peripheral air pipe (110) is sleeved outside the main gas pipeline (120) and is coaxially arranged with the main gas pipeline (120); the peripheral air tube (110) includes an air tube constriction (130) mounted at an end thereof; an air injection section (140) is sleeved at the downstream of the peripheral air pipe (110); an air expansion opening (150) is formed in the end of the air injection section (140);
peripheral gas branch pipes (160) which are uniformly installed are sequentially installed on the main gas pipeline (120), oblique gas branch pipe bodies (122) which are uniformly installed on the main gas pipeline (120) are sequentially installed, and radial injection holes (121) are uniformly formed in the end portion of the main gas pipeline (120); an air flow divider (170) which is coaxially arranged is installed between the peripheral air pipe (110) and the main fuel gas pipeline (120), the contraction opening of the air pipe contraction opening (130) is not closed, and a channel exists between the air pipe contraction opening (130) and the air flow divider (170).
2. The staged flue gas internal circulation low-nitrogen combustor according to claim 1, wherein: and a flame stabilizing disc (124) is arranged at the end part of the air splitter (170), the flame stabilizing disc (124) is positioned between the inclined gas branch pipe body (122) and the radial injection hole (121), and a swirl vane (123) and an inclined gas branch pipe hole (124) are arranged on the flame stabilizing disc.
3. The staged flue gas internal recycle low-nitrogen combustor according to claim 2, wherein: the inclined gas branch pipe hole (124) is a gas outlet of the inclined gas branch pipe body (122).
4. The staged flue gas internal circulation low-nitrogen combustor according to claim 1, wherein: one side of the main gas pipeline (120) is annularly provided with a peripheral gas branch pipe (160), one end of the peripheral gas branch pipe (160) penetrates through the air expansion opening (150), the penetrating part of the end of the peripheral gas branch pipe bends towards the central shaft and is distributed with peripheral branch pipe gas side spray holes (162), and the end center of the peripheral gas branch pipe (160) is provided with a peripheral branch pipe central gas spray hole (161).
5. The staged flue gas internal recycle low-nitrogen combustor according to claim 4, wherein: the peripheral gas branch pipe (160) and the oblique gas branch pipe body (122) are arranged in a crossed mode.
6. The staged flue gas internal recycle low-nitrogen combustor according to claim 2, wherein: the number of the swirl vanes (123) is 4-10.
7. The staged flue gas internal recycle low-nitrogen combustor according to claim 2, wherein: the rotational flow angle of the rotational flow blade (123) is 20-60 degrees.
8. The staged flue gas internal recycle low-nitrogen combustor according to claim 1, wherein: the number of the radial injection holes (121) is 4 to 12.
9. The staged flue gas internal recycle low-nitrogen combustor according to claim 4, wherein: the gas ventilation area of the gas side spray holes (162) of the peripheral branch pipe accounts for 70-90%.
CN202210801813.5A 2022-07-07 2022-07-07 Hierarchical flue gas inner loop low NOx burner Pending CN115143463A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210801813.5A CN115143463A (en) 2022-07-07 2022-07-07 Hierarchical flue gas inner loop low NOx burner

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210801813.5A CN115143463A (en) 2022-07-07 2022-07-07 Hierarchical flue gas inner loop low NOx burner

Publications (1)

Publication Number Publication Date
CN115143463A true CN115143463A (en) 2022-10-04

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ID=83411679

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Application Number Title Priority Date Filing Date
CN202210801813.5A Pending CN115143463A (en) 2022-07-07 2022-07-07 Hierarchical flue gas inner loop low NOx burner

Country Status (1)

Country Link
CN (1) CN115143463A (en)

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