阅读说明：本技术 一种带有肋片异径燃气自旋预混多用途燃烧器 (Multi-purpose burner with fins and different-diameter gas self-rotating premixing function ) 是由 惠世恩 龚彦豪 牛艳青 王登辉 李帅飞 姚启 赵梦娇 雷雨 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种带有肋片异径燃气自旋预混多用途燃烧器,包括燃烧器外二次风套筒外围由预燃室壳体围成的预燃室。预燃室壳体外侧套有燃尽风套筒,预燃室壳体尾部端面沿预燃室出口轴线周向对称开设有外扩式燃尽风喷口。外二次风套筒出口处和燃尽风套筒通道内设置有轴向旋流叶片。本发明作为燃气燃烧器投用时,内、外二次风均为高速射流,燃气在大尺度湍动条件下与空气以及烟气在炉膛内弥散混合,有效降低NO<Sub>x</Sub>生成量。当作为煤粉燃烧器投用时,预燃室壳体尾部端面开设的外扩式喷口在与燃尽风轴向旋流叶片的共同作用下,使喷出的燃尽风围绕预燃室出口轴线形成外扩式高速旋转射流,进入炉膛的气粉混合物在MILD燃烧条件下进行燃烧,NO<Sub>x</Sub>生成量显著降低。(The invention discloses a rib-type reducing gas spinning premixing multipurpose combustor, which comprises a precombustion chamber, wherein the periphery of a secondary air sleeve outside the combustor is surrounded by a precombustion chamber shell. The outer side of the precombustion chamber shell is sleeved with an over-fire air sleeve, and the tail end face of the precombustion chamber shell is symmetrically provided with outward-expanding over-fire air nozzles along the circumferential direction of the outlet axis of the precombustion chamber. Axial swirl blades are arranged at the outlet of the outer secondary air sleeve and in the channel of the over-fire air sleeve. When the invention is used as a gas burner, the inner part,The outer secondary air is high-speed jet flow, and the fuel gas is dispersed and mixed with air and flue gas in the hearth under the condition of large-scale turbulence, so that NO is effectively reduced x The amount of production. When the jet type pulverized coal burner is used as a pulverized coal burner, the outward-expanding nozzle arranged on the tail end face of the precombustion chamber shell and the axial swirl vane of the overfire air jointly act to enable the ejected overfire air to form outward-expanding high-speed rotating jet flow around the outlet axis of the precombustion chamber, and a gas-powder mixture entering a hearth is combusted under the MILD combustion condition, NO is not used, and the jet type pulverized coal burner is not used as a pulverized coal burner x The production amount is remarkably reduced.)

1. The utility model provides a have fin reducing gas spin and premix multipurpose combustor which characterized in that includes:

the precombustion chamber (6), the precombustion chamber (6) is enclosed by the precombustion chamber casing (5), and connect in the periphery of the outer overgrate air sleeve (4); a gas sleeve (18), an air diversion sleeve (11), a gas combustion-supporting air sleeve (2), a primary air sleeve (3), a refractory cement isolation belt (17), an inner secondary air sleeve (16) and an outer secondary air sleeve (4) are sequentially sleeved at an inlet of the precombustion chamber (6) from inside to outside;

the pre-combustion chamber comprises a pre-combustion chamber shell (5), an over-fire air sleeve (7) is sleeved on the outer side of the pre-combustion chamber shell (5), and a plurality of over-fire air nozzles (9) are symmetrically arranged on the tail end face of the pre-combustion chamber shell (5) along the circumferential direction of the outlet axis of the pre-combustion chamber (6);

the gas sleeve (18), the gas sleeve (18) is provided with a plurality of gas premixing nozzles (13) and a plurality of gas non-premixing nozzles (10);

the pipeline of the gas premixing nozzle (13) is embedded in an annular channel formed by the air distribution sleeve (11) and the gas combustion-supporting air sleeve (2) through a rotational flow rib (14); and an annular channel between the gas premixing nozzle (13) and the outlet of the gas combustion air sleeve (2) is a gas premixing channel (12).

2. The multi-purpose burner with rib reducing gas spinning premixing of claim 1 characterized in that the gas sleeve (18) is provided with a gas inlet (19) on its side; a gas combustion-supporting air inlet (1) is arranged on the side surface of the gas combustion-supporting air sleeve (2).

3. The multi-purpose burner with fins and different diameters for gas spinning premixing as claimed in claim 1 or 2, characterized in that the gas sleeve (18) is provided with 8 different diameter gas premixing nozzles (13) with oval cross-sections along the circumference of the axis, the circumferential positioning angle of the gas premixing nozzle (13) pipeline relative to the gas sleeve (18) is theta, theta is more than or equal to 30 degrees and less than or equal to 60 degrees, so that the ejected gas forms a rotating jet around the axis of the gas sleeve (18) to be mixed with gas combustion air in the gas premixing channel (12).

4. The multi-purpose burner with the rib and the different diameter for the gas spinning premixing as recited in claim 1 or 2, characterized in that two swirl ribs (14) are symmetrically connected to the periphery of each pipe of the gas premixing nozzle (13), the swirl angle of the ribs is the same as the circumferential positioning angle of the pipe of the gas premixing nozzle (13) relative to the gas sleeve (18), and the pipe of the gas premixing nozzle (13) is embedded in the annular channel formed by the air distribution sleeve (11) and the gas combustion air sleeve (2) through the swirl ribs (14).

5. The multi-purpose burner with fins and different diameters for gas spinning and premixing as claimed in claim 1, characterized in that the outlet of the outer secondary air sleeve (4) is provided with outer secondary air axial swirl vanes (15), the swirl angle of the outer secondary air axial swirl vanes (15) is η, η is 50 degrees or more and 70 degrees or less, and the outer secondary air enters the precombustion chamber (6) in a rotating jet mode.

6. The rib-type reducing gas spinning premixing multipurpose burner as claimed in claim 1, characterized in that an overfire air axial swirl vane (8) is arranged in the passage of the overfire air sleeve (7), the swirl angle of the overfire air axial swirl vane (8) is delta, delta is more than or equal to 50 degrees and less than or equal to 70 degrees, and the overfire air enters the furnace chamber through the overfire air nozzle (9) in a rotating jet manner.

7. The multi-purpose burner with the rib-type reducing gas spinning premixing function as claimed in claim 1, wherein 8 outward-expanding type over-fire air nozzles (9) are symmetrically arranged on the end surface of the tail portion of the precombustion chamber shell (5) along the circumferential direction of the outlet axis of the precombustion chamber (6), the expansion angle of the nozzles is 20-30 degrees, and under the combined action of the over-fire air axial swirl vanes (8), the ejected over-fire air forms outward-expanding type high-speed rotating jet flow around the outlet axis of the precombustion chamber (6).

[ technical field ] A method for producing a semiconductor device

The invention belongs to the technical field of heat energy and power engineering, and relates to a cyclone burner, in particular to a ribbed reducing gas spinning premixing multipurpose burner for enhancing the adaptability of the burner to the types of fuels and reducing NO in the fuel combustion process_xAnd (4) generating.

[ background of the invention ]

Fossil energy will be the subject of consumption of energy for a long period of time in the future. In recent years, the proportion of natural gas consumption to the total energy consumption has increased year by year. Fossil fuel combustion is Nitrogen Oxides (NO)_x) Main source of (3), NO_xIs one of the main reasons of photochemical smog, acid rain and haze weather, and seriously harms the atmospheric environment and human health.

The MILD (model or Intense Low Oxygen combustion) combustion technology can effectively control the generation of NOx, and is rapidly developed in recent years. The fuel adaptability of the MILD combustion technology is strong, and the MILD can be widely applied to solid, liquid and gaseous fuels; the flame formed by the combustion mode is in a dispersion shape, the combustion area is large, the peak temperature is low, the heat flow distribution is uniform, the oxygen concentration close to the burner area is obviously lower than that of the traditional combustion mode, and the NO is inhibited_xAnd high combustion efficiency can be ensured while the fuel is generated. By rational organization of the burners, MILD is burned and emptiedGas fractionation with two low NO_xThe combustion technology is coupled and applied to the combustion of natural gas and coal powder, so that the synergistic denitration effect is exerted, and NO is further reduced_xAnd (5) discharging.

[ summary of the invention ]

The present invention is directed to overcoming the above-mentioned deficiencies in the prior art and providing a method for enhancing the flexibility of a burner to fuel types and reducing NO during combustion of fuels_xThe generated rib-containing reducing gas spinning premixing multipurpose combustor can switch combustion organization modes to adapt to the combustion conditions of natural gas and pulverized coal respectively, and the requirement of strong fuel variety adaptability of the combustor is met. Meanwhile, through the reasonable organization of the burner, MILD combustion and air classification are carried out_xThe combustion technology is coupled and applied to the combustion of natural gas and coal powder, so that the synergistic denitration effect is exerted, and NO is further reduced_xAnd (5) discharging.

In order to achieve the purpose, the invention adopts the technical scheme that:

the utility model provides a have fin reducing gas spin to mix multipurpose combustor in advance, includes:

the precombustion chamber is surrounded by a precombustion chamber shell and is connected with the periphery of the outer secondary air sleeve; a gas sleeve, an air distribution sleeve, a gas combustion-supporting air sleeve, a primary air sleeve, a refractory cement isolation zone, an inner secondary air sleeve and an outer secondary air sleeve are sequentially sleeved at the inlet of the precombustion chamber from inside to outside;

the pre-combustion chamber comprises a pre-combustion chamber shell, wherein a burnout air sleeve is sleeved on the outer side of the pre-combustion chamber shell, and a plurality of burnout air nozzles are symmetrically arranged on the end surface of the tail part of the pre-combustion chamber shell along the axial line of an outlet of the pre-combustion chamber in the circumferential direction;

the gas sleeve is provided with a plurality of gas premixing nozzles and a plurality of gas non-premixing nozzles;

the gas premixing nozzle pipeline is embedded in an annular channel formed by the air distribution sleeve and the gas combustion-supporting air sleeve through a rotational flow fin; and an annular channel between the gas premixing nozzle and the outlet of the gas combustion-supporting air sleeve is a gas premixing channel.

The invention further improves the following steps:

a gas inlet is formed in the side surface of the gas sleeve; the side surface of the gas combustion-supporting air sleeve is provided with a gas combustion-supporting air inlet.

The gas sleeve is provided with 8 reducing gas premixing nozzles with oval cross sections along the circumferential direction of the axis, the circumferential positioning angle of a gas premixing nozzle pipeline relative to the gas sleeve is theta, theta is more than or equal to 30 degrees and less than or equal to 60 degrees, and the sprayed gas forms rotary jet flow around the axis of the gas sleeve and is mixed with gas combustion-supporting air in a gas premixing channel.

The periphery of each pipeline of the gas premixing nozzle is symmetrically connected with two sets of swirl fins, the swirl angle of each swirl fin is the same as the circumferential positioning angle of the gas premixing nozzle pipeline relative to the gas sleeve, and the gas premixing nozzle pipeline is embedded in an annular channel formed by the air distribution sleeve and the gas combustion-supporting air sleeve through the swirl fins.

An outer secondary air axial swirl blade is arranged at the outlet of the outer secondary air sleeve, the swirl angle of the outer secondary air axial swirl blade is η, the swirl angle is equal to or larger than 50 degrees and equal to or larger than η degrees and equal to or smaller than 70 degrees, and the outer secondary air enters the precombustion chamber in a rotary jet mode.

The axial swirl blades of the over-fire air are arranged in the over-fire air sleeve channel, the swirl angle of the axial swirl blades of the over-fire air is delta, delta is more than or equal to 50 degrees and less than or equal to 70 degrees, and the over-fire air enters the hearth through the over-fire air nozzle in a rotary jet mode.

8 outer expanding type over-fire air nozzles are symmetrically arranged on the end face of the tail part of the precombustion chamber shell along the circumferential direction of the axis of the precombustion chamber outlet, the expansion angle of the nozzles is 20-30 degrees, and under the combined action of the nozzles and the axial swirl blades of the over-fire air, the ejected over-fire air forms an outer expanding type high-speed rotating jet flow around the axis of the precombustion chamber outlet.

Compared with the prior art, the invention has the following beneficial effects:

the invention relates to a rib-type reducing gas self-rotating premixing multipurpose burner. When the air-fuel combustor is used as a gas combustor, the primary air channel and the over-fire air channel are closed; the gas premixing nozzle enables the sprayed gas to form rotary jet flow around the axis of the gas sleeve, and the rotary jet flow is quickly mixed with gas combustion air in the gas premixing channel; from non-premixed jets of gasThe fuel gas and the combustion air are subjected to non-premixed combustion in the precombustion chamber; the inner secondary air is high-speed direct current jet flow (65-100 m/s), the outer secondary air is high-speed rotating jet flow (65-100 m/s), the inner secondary air and the outer secondary air suck a large amount of high-temperature flue gas from the jet flow boundary to flow back, the precombustion chamber and the main combustion area are enabled to present reducing atmosphere, the fuel gas is subjected to strong disturbance and is mixed with air and flue gas in a dispersion mode in the hearth, combustion is carried out under the MILD combustion condition, and NO is effectively reduced_xThe amount of production. When the burner is put into operation as a pulverized coal burner, the gas channel and the gas combustion air channel are closed; the primary air-powder mixture enters the precombustion chamber through volute diversion in a rotary jet mode to quickly release volatile components, the inner secondary air appropriately supplements oxygen to enable the volatile components to be combusted in a partial mode to improve the ignition stability of the coal powder, and then coal powder particles entering a hearth are dispersed and distributed in the hearth under the drive of the self rotary jet, the outer secondary air and the rotary jet of over-fire air; simultaneously, the outer formula of expanding after-combustion wind spout that sets up of precombustion chamber casing afterbody terminal surface under the combined action with the axial whirl blade of after-combustion wind, make the blowout after-combustion wind form outer formula high-speed rotatory efflux (65 ~ 100m/s) of expanding around precombustion chamber export axis, the length and the width at efflux boundary have been prolonged, the increase of recirculation zone area, a large amount of high temperature flue gas is inhaled the backward flow by the entrainment, make buggy main combustion zone present reducing atmosphere, the gas-powder mixture that gets into furnace burns under MILD combustion conditions, NO is_xThe production amount is remarkably reduced.

Furthermore, the gas premixing nozzle pipeline is embedded in an annular channel formed by the air distribution sleeve and the gas combustion-supporting air sleeve through the rotational flow fins, and the annular channel formed by the air distribution sleeve and the gas combustion-supporting air sleeve is divided into a plurality of gas combustion-supporting air axial rotational flow channels by the gas premixing nozzle pipeline and the rotational flow fins; part of the gas combustion-supporting air forms rotary jet flow around the axis of the gas sleeve after being guided through the gas combustion-supporting air axial rotational flow channel, and is quickly mixed with the gas in the gas premixing channel for premixed combustion, so that NO is further reduced_xAnd (4) generating.

[ description of the drawings ]

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a cross-sectional view taken along the line A-A of the present invention;

FIG. 3 is a cross-sectional view taken along the line B-B of the present invention;

FIG. 4 is a right side view of the present invention;

FIG. 5 is a schematic view of the structure of the gas sleeve and swirl fins of the present invention;

FIG. 6 is a partial cross-sectional view of the gas premix nozzle conduit and swirl fins of the present invention.

Wherein, 1-a gas combustion air inlet; 2-gas combustion air sleeve; 3-primary air sleeve; 4-outer secondary air sleeve; 5-a prechamber housing; 6-precombustion chamber; 7-an over-fire air sleeve; 8-over-fire air axial swirl blades; 9-over-fire air nozzle; 10-gas non-premixing nozzle; 11-air diverter sleeve; 12-a gas premixing channel; 13-gas premixing spout; 14-swirl fins; 15-outer secondary air axial swirl vanes; 16-inner overfire air sleeve; 17-refractory cement barrier zone; 18-a gas sleeve; 19-gas inlet.

[ detailed description ] embodiments

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1-6, the multi-purpose burner with rib reducing gas spinning premixing comprises an outer secondary air sleeve 4 of the burner, wherein the periphery of the outer secondary air sleeve 4 is connected with a precombustion chamber 6 surrounded by a precombustion chamber shell 5, and a gas sleeve 18, an air diversion sleeve 11, a gas combustion-supporting air sleeve 2, a primary air sleeve 3, a refractory cement isolation belt 17, an inner secondary air sleeve 16 and the outer secondary air sleeve 4 are sequentially sleeved at an inlet of the precombustion chamber 6 from inside to outside.

The outer side of the precombustion chamber shell 5 is sleeved with an over-fire air sleeve 7, the end surface of the tail part of the precombustion chamber shell 5 is symmetrically provided with a plurality of outward-expanding over-fire air nozzles 9 along the circumferential direction of the outlet axis of the precombustion chamber 6, the expansion angle of the nozzles is 20-30 degrees, and under the combined action of the over-fire air nozzles and the axial swirl vanes 8, the ejected over-fire air forms outward-expanding high-speed rotating jet flow around the outlet axis of the precombustion chamber 6.

A gas inlet 19 is formed in the side surface of the gas sleeve 18; the gas sleeve 18 is circumferentially provided with a plurality of reducing gas premixing nozzles 13 with oval cross sections along the axis, the circumferential positioning angle of the pipeline of the gas premixing nozzles 13 relative to the gas sleeve 18 is theta, and theta is more than or equal to 30 degrees and less than or equal to 60 degrees; two sets of swirl fins 14 are symmetrically connected to the periphery of each pipeline of the gas premixing nozzle 13, the swirl angle of the fins is the same as the circumferential positioning angle of the pipeline of the gas premixing nozzle 13 relative to the gas sleeve 18, and the pipeline of the gas premixing nozzle 13 is embedded in an annular channel formed by the air distribution sleeve 11 and the gas combustion-supporting air sleeve 2 through the swirl fins 14; an annular channel between the gas premixing nozzle 13 and the outlet of the gas combustion air sleeve 2 is a gas premixing channel 12; meanwhile, the gas sleeve 18 is circumferentially provided with a plurality of gas non-premixing nozzles 10 along the axis, and the gas non-premixing nozzles 10 are positioned on the outlet end face of the gas sleeve 18.

The annular channel formed by the air distribution sleeve 11 and the gas combustion-supporting air sleeve 2 is divided into a plurality of gas combustion-supporting air axial rotational flow channels by the gas premixing nozzle 13 pipeline and the rotational flow ribs 14; part of the gas combustion-supporting air forms rotary jet flow around the axis of the gas sleeve 18 after being guided by the gas combustion-supporting air axial rotational flow channel.

A gas combustion-supporting air inlet 1 is formed in the side surface of the gas combustion-supporting air sleeve 2; the primary air inlet sends the mixture of the pulverized coal and the air which form rotational flow through the volute into the primary air sleeve 3; the mixture of the pulverized coal and the air flows in an annular channel between the primary air sleeve 3 and the gas combustion air sleeve 2, and forms a rotary jet flow at the outlet of the primary air sleeve 3.

A refractory cement isolation belt 17 is arranged between the inner secondary air sleeve 16 and the primary air sleeve 3, an outer secondary air axial swirl blade 15 is arranged at an outlet of the outer secondary air sleeve 4, the swirl angle of the blade is η, and is not less than 50 degrees and not more than η degrees, an over-fire air axial swirl blade 8 is arranged in a channel of the over-fire air sleeve 7, the swirl angle of the blade is delta, and the delta is not less than 50 degrees and not more than 70 degrees.

The natural gas flows in the gas sleeve 18 and is sprayed out from the gas premixing nozzle 13 and the gas non-premixing nozzle 10; the gas combustion-supporting air flows in the gas combustion-supporting air sleeve 2; the mixture of the pulverized coal and the air is fed from the primary air inlet and flows in an annular channel between the primary air sleeve 3 and the fuel gas combustion-supporting air sleeve 2; the inner secondary air flows in an annular channel between the inner secondary air sleeve 16 and the refractory cement isolation belt 17; the outer secondary air flows in an annular channel between the outer secondary air sleeve 4 and the inner secondary air sleeve 16; the overfire air flows in an annular passage between the overfire air sleeve 7 and the outer surface of the prechamber housing 5.

The principle of the invention is as follows:

when the gas premixing nozzle is used as a gas burner, the gas premixing nozzle enables the sprayed gas to form rotary jet flow around the axis of a gas sleeve, and the rotary jet flow is quickly mixed with gas combustion-supporting air in a gas premixing channel; and the gas sprayed from the gas non-premixing nozzle is subjected to non-premixed combustion with combustion air in the precombustion chamber. The gas premixing nozzle pipeline and the swirl fins divide an annular channel formed by the air distribution sleeve and the gas combustion air sleeve into 8 paths of gas combustion air axial swirl channels; part of the gas combustion-supporting air forms rotary jet flow around the axis of the gas sleeve after being guided through the gas combustion-supporting air axial rotational flow channel, and is quickly mixed with the gas in the gas premixing channel for premixed combustion, so that NO is reduced_xThe amount of production. The inner secondary air is high-speed direct current jet flow (65-100 m/s), the outer secondary air is high-speed rotating jet flow (65-100 m/s), the inner secondary air and the outer secondary air suck a large amount of high-temperature flue gas from the jet flow boundary to flow back, the precombustion chamber and the main combustion area are enabled to present reducing atmosphere, the fuel gas is subjected to strong disturbance and is mixed with air and flue gas in a dispersion mode in the hearth, combustion is carried out under the MILD combustion condition, and NO is effectively reduced_xThe amount of production.

When the pulverized coal burner is used as a pulverized coal burner, the rotary jet flow of primary air and external secondary air forms a backflow area in the precombustion chamber, high-temperature smoke is sucked in an entrainment mode to backflow to heat pulverized coal in the precombustion chamber, the pulverized coal is heated in the precombustion chamber and quickly decomposed to release a large amount of volatile components, and the volatile components are combusted in different parts to provide heat for the precombustion chamber. Under the reducing atmosphere with the excess air coefficient less than 1, the nitrogen-containing compounds in the volatile components are reduced into N through a series of reactions in the precombustion chamber₂So that NO is_xThe amount of production decreases. Meanwhile, the content of oxygen in the high-temperature flue gas flowing back into the precombustion chamber is lower, so that the oxygen concentration in the precombustion chamber is further reduced, and NO is inhibited_xAnd (4) generating.

In order to ensure a low oxygen environment in the precombustion chamber, it is required to:

(primary air volume (coal powder) + internal secondary air volume + external secondary air volume)/total air volume calculated by theory required by coal powder combustion is less than 0.6.

I.e. the total air excess factor in the prechamber is less than 0.6.

According to the external expansion type over-fire air nozzle arranged on the tail end face of the precombustion chamber shell, under the combined action of the external expansion type over-fire air nozzle and the over-fire air axial swirl blades, the ejected over-fire air forms external expansion type high-speed rotating jet flow (65-100 m/s) around the axis of the outlet of the precombustion chamber, the length and the width of a jet flow boundary are prolonged, the area of a backflow area is increased, a large amount of high-temperature flue gas is sucked and flows back in a curling manner, and a main combustion area of pulverized coal presents reducing atmosphere; the coal powder particles entering the hearth are dispersed and distributed in the hearth under the driving of the self-rotating jet flow, the outer secondary air and the rotating jet flow of the over-fire air, the gas-powder mixture in the hearth is combusted under the MILD combustion condition, and NO is added_xThe production amount is remarkably reduced.

The working process of the invention is as follows:

when the air-fuel combustor is used as a gas combustor, the primary air channel and the over-fire air channel are closed. Gas combustion-supporting air, inner secondary air and outer secondary air are fed in through a gas combustion-supporting air inlet 1, an inner secondary air inlet and an outer secondary air inlet, the gas combustion-supporting air flows in a gas combustion-supporting air sleeve 2, the inner secondary air flows in an annular channel between an inner secondary air sleeve 16 and a refractory cement isolation belt 17, the outer secondary air flows in an annular channel between an outer secondary air sleeve 4 and an inner secondary air sleeve 16, the gas combustion-supporting air, the inner secondary air and the outer secondary air enter a precombustion chamber 6, and the precombustion chamber 6 is purged for more than 1 minute.

The high-energy igniter and the oil gun or the gas gun are sent to a specified ignition position through the ignition propeller to be ignited. Gas combustion-supporting air, inner secondary air and outer secondary air are fed in through a gas combustion-supporting air inlet 1, an inner secondary air inlet and an outer secondary air inlet, the gas combustion-supporting air flows in a gas combustion-supporting air sleeve 2, the inner secondary air flows in an annular channel between an inner secondary air sleeve 16 and a refractory cement isolation belt 17, the outer secondary air flows in an annular channel between an outer secondary air sleeve 4 and an inner secondary air sleeve 16, and the gas combustion-supporting air, the inner secondary air and the outer secondary air enter a precombustion chamber 6. An outer secondary air axial swirl vane 15 is arranged at the outlet of the outer secondary air sleeve 4, and the outer secondary air enters the precombustion chamber 6 in a rotary jet mode.

Natural gas is fed from a gas inlet 19, and the natural gas is sprayed out from the gas premixing nozzle 13 and the gas non-premixing nozzle 10 through the gas sleeve 18. The gas premixing nozzle 13 enables the sprayed gas to form rotary jet flow around the axis of the gas sleeve 18, and the rotary jet flow is rapidly mixed with gas combustion air in the gas premixing channel 12; the gas ejected from the gas non-premixing nozzle 10 is non-premixed with the combustion air in the precombustion chamber 6. The annular channel formed by the air distribution sleeve 11 and the gas combustion air sleeve 2 is divided into 8 paths of gas combustion air axial rotational flow channels by the gas premixing nozzle 13 pipeline and the rotational flow ribs 14; part of the gas combustion-supporting air forms rotary jet flow around the axis of the gas sleeve 18 after being guided by the gas combustion-supporting air axial rotational flow channel, and is quickly mixed with the gas in the gas premixing channel 12 for premixed combustion, so that NO is reduced_xThe amount of production. After entering the prechamber 6, the gas is ignited by the flame produced by the oil or gas gun outlet. The inner secondary air is high-speed direct current jet flow (65-100 m/s), the outer secondary air is high-speed rotating jet flow (65-100 m/s), the inner secondary air and the outer secondary air suck a large amount of high-temperature flue gas from the jet flow boundary to flow back, the precombustion chamber 6 and the main combustion area are enabled to present reducing atmosphere, the fuel gas is subjected to strong disturbance and is mixed with the air and the flue gas in a dispersion mode in the hearth, combustion is carried out under the MILD combustion condition, and NO is effectively reduced_xThe amount of production.

After the gas in the pre-combustion chamber 6 is stably combusted, the high-energy igniter and the oil gun or the gas gun are withdrawn through the ignition propeller. Meanwhile, the infrared flame monitoring device monitors the combustion flame state in real time through the peeping device, and when fire extinguishment occurs, an alarm is given out, the input of fuel gas is stopped in time, and purging and ignition operations are executed again.

When the burner is used as a pulverized coal burner, the gas channel and the gas combustion air channel are closed. And (2) feeding the inner secondary air and the outer secondary air through an inner secondary air inlet and an outer secondary air inlet, wherein the inner secondary air flows in an annular passage between the inner secondary air sleeve 16 and the refractory cement isolation belt 17, the outer secondary air flows in an annular passage between the outer secondary air sleeve 4 and the inner secondary air sleeve 16, and the inner secondary air and the outer secondary air enter the precombustion chamber 6 to purge the precombustion chamber 6 for more than 1 minute.

The high-energy igniter and the oil gun or the gas gun are sent to a specified ignition position through the ignition propeller to be ignited. The inner secondary air and the outer secondary air are fed in through an inner secondary air inlet and an outer secondary air inlet, the inner secondary air flows in an annular passage between the inner secondary air sleeve 16 and the refractory cement isolation belt 17, the outer secondary air flows in an annular passage between the outer secondary air sleeve 4 and the inner secondary air sleeve 16, and the inner secondary air and the outer secondary air enter the precombustion chamber 6. An outer secondary air axial swirl vane 15 is arranged at the outlet of the outer secondary air sleeve 4, and the outer secondary air enters the precombustion chamber 6 in a rotary jet mode.

The mixture of the pulverized coal and the air which forms rotational flow through the volute is sent into the primary air sleeve 3 through the primary air inlet, the mixture of the pulverized coal and the air flows in an annular channel between the primary air sleeve 3 and the fuel gas combustion air sleeve 2, and a rotary jet flow is formed at the outlet of the primary air sleeve 3. After entering the pre-combustion chamber 6, the pulverized coal is pyrolyzed to release volatile components, and the volatile components are ignited by flame generated by an outlet of an oil gun or a gas gun. Under the condition that the oxygen content carried by the primary air and the secondary air is insufficient, the precombustion chamber 6 presents a reducing atmosphere, and nitrogen-containing compounds generated by coal dust pyrolysis are reduced into N through a series of reactions₂So that NO is_xThe production amount is effectively reduced. The mixture formed by the unburned volatile components, the high-temperature flue gas and the pulverized coal particles is uniformly mixed in the rear half section of the precombustion chamber 6 and then enters the hearth for combustion.

Overfire air is fed in through an overfire air inlet and flows in an annular passage between the overfire air sleeve 7 and the outer surface of the prechamber housing 5. The end surface of the tail part of the precombustion chamber shell 5 is symmetrically provided with a plurality of outward-expanding type over-fire air nozzles 9 along the circumferential direction of the outlet axis of the precombustion chamber 6, the expansion angle of the nozzles is 20-30 degrees, and under the combined action of the nozzles and the over-fire air axial swirl vanes 8, the ejected over-fire air forms outward-expanding type high-speed rotating jet flow (65-100 m/s) around the outlet axis of the precombustion chamber 6, so that the jet flow boundary length is prolongedThe degree and the breadth are increased, the area of the backflow zone is increased, and a large amount of high-temperature flue gas is sucked and flows back in a curling manner, so that the main combustion zone of the pulverized coal presents reducing atmosphere; the coal powder particles entering the hearth are dispersed and distributed in the hearth under the driving of the self-rotating jet flow, the outer secondary air and the rotating jet flow of the over-fire air, the gas-powder mixture in the hearth is combusted under the MILD combustion condition, and NO is added_xThe production amount is remarkably reduced.

After the pulverized coal in the pre-combustion chamber 6 is stably ignited, the high-energy igniter and the oil gun or the gas gun are withdrawn through the ignition propeller. Meanwhile, the infrared flame monitoring device monitors the combustion flame state in real time through the fire peeping device, and when fire extinguishment occurs, an alarm is given out, the input of pulverized coal is stopped in time, and purging and ignition operations are executed again.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.