WO2019223144A1

WO2019223144A1 - Low-nitrogen oxide gas burner and flame adjustment method therefor

Info

Publication number: WO2019223144A1
Application number: PCT/CN2018/102076
Authority: WO
Inventors: 代森伟; 任传波; 孙仁权
Original assignee: 安德森热能科技（苏州）有限责任公司
Priority date: 2018-05-21
Filing date: 2018-08-24
Publication date: 2019-11-28
Also published as: CN110513680A; CN110513680B

Abstract

A low-nitrogen oxide (NOx) gas burner, comprising: a main pipe body (1) and an inner core pipe (2). Under conditions of a constant amount of gas intake, the size of a gap between an inner core pipe (2) head and the main pipe body (1) is changed by means of a first position adjustment mechanism (4), thereby changing the total size of an outlet of the burner, thus changing the flow rate and controlling flame length. Under conditions of a constant flow rate, the amount of gas distributed to the inner core pipe (2) and the main pipe body (1) inner cavity is changed by means of a gas distribution adjustment mechanism, thus adjusting the position of the focus of heat energy in the flame. The appropriate flame length can be rapidly adjusted and lower NOx emissions produced. The position of the focus of heat energy released in the flame can also be conveniently adjusted, improving radiation transmittance.

Description

Low nitrogen oxide gas burner and flame regulating method thereof

Technical field

The invention relates to a gas burner, in particular to a low nitrogen oxide gas burner and a flame regulating method thereof.

Background technique

Glass furnaces in industrial kilns, especially regenerators, have extremely high combustion temperatures, usually in the range of 1300-1650 ° C. Due to the high temperature of the furnace and flame, a large amount of NOx emissions are generated. In order to solve the increasingly stringent emission restrictions, many development technologies have suppressed the formation of nitrogen oxides by modifying the air-fuel ratio, including oxygen-enriched air classification, but such technological transformation investment is very large and the use cost is high.

At present, jet flames are also used to generate lower NOx emissions than traditional ones. The burner body is equipped with a manual speed adjustment mechanism. By changing the area of the flame outlet, the flow velocity is changed to control the flame length. However, after the flame length adjustment is stable, the change of the concentrated release position of the flame heat energy cannot be achieved.

Summary of the Invention

In order to overcome the above-mentioned shortcomings of the prior art, an object of the present invention is to provide a low nitrogen oxide gas burner and a flame adjusting method thereof. In the following content of this application, "NOx" is equivalent to "nitrogen oxide".

In order to achieve the above objective, the technical solution adopted by the present invention to solve its technical problems is:

A low nitrogen oxide gas burner includes:

A main body with a gas inlet on its body;

An inner core tube, which is penetrated through the inner cavity of the main pipe, the head of the inner core pipe is correspondingly provided in the head region of the main pipe, and the head of the inner core pipe is a tapered surface;

A first position adjusting mechanism for adjusting an axial position of the inner core tube relative to the main body to change a gap between the inner core tube head and the main body;

The gas distribution adjustment mechanism is used to adjust the ratio of gas distribution to the inner cavity of the inner core tube and the inner cavity of the main pipe.

Compared with the prior art, the present invention changes the size of the gap between the head of the inner core tube and the main body through the first position adjustment mechanism under the condition of a certain amount of gas intake air, that is, changes the total outlet size of the burner. In order to change the flow velocity and control the length of the jet flame; adjust the ratio of the gas distribution to the inner cavity of the core tube and the main cavity of the main body through the gas distribution adjustment mechanism to achieve the adjustment of the position of the thermal energy concentrated in the stream flame; the jet flame of the appropriate length can be adjusted quickly It produces lower NOx emissions, and at the same time, it is convenient to adjust the position of concentrated release of thermal energy in the jet flame, which improves the radiation transmittance.

Further, the gas distribution adjustment mechanism includes:

An outer core tube that is inserted through the inner cavity of the main tube and is sleeved on the outer periphery of the inner core tube. The head of the outer core tube is provided in the inner cavity of the main tube and away from the head of the main body. A first opening, a first gas control portion extending from the inner cavity of the main pipe, the first gas control portion can partially block the opening of the first opening; the tube body of the inner core tube is provided with a communicating inner core tube; Cavity and the second opening of the inner cavity of the outer core tube;

A second position adjustment mechanism for adjusting an axial position of the outer core tube relative to the main body to change an opening area where the first opening exposes the first gas control portion;

Part of the gas entering from the gas inlet to the main body cavity is ejected from the main body cavity opening through the main body cavity, and the other part enters the inner cavity of the inner core tube through the first opening and the second opening through the inner core tube head. Squirting from the opening.

With the above-mentioned preferred solution, when the gas intake is constant, the size of the gap between the inner core tube head and the main body is changed by the first position adjustment mechanism, that is, the total outlet size of the burner is changed, thereby changing the flow rate. To control the length of the jet of flame; under the condition of a constant flow rate, the second position adjustment mechanism is used to change the amount of gas that enters the inner tube and the main cavity of the main pipe, thereby adjusting the position of the thermal energy concentrated in the stream of flame; Quickly adjust the jet flame of the appropriate length to generate lower NOx emissions, and at the same time, it can easily adjust the position of concentrated release of thermal energy in the jet flame, which improves the radiation transmittance.

Further, the head of the outer core tube is a tapered surface, and a second air control portion extends from the inner cavity of the main tube, and the gap between the second air control portion and the head of the outer core tube is constructed from the main tube head. A gas passage spouted from the opening.

With the above preferred solution, as the second position adjustment mechanism drives the axial movement of the outer core tube relative to the main body, when the flow port of the first gas control section is enlarged / reduced, the flow port of the second gas control section is simultaneously reduced / Enlarged, the first air control unit and the second air control unit simultaneously adjust the flow distribution into the inner core tube and the main body lumen respectively, reducing the adjustment stroke of the second position adjustment mechanism, and the volume configuration of each tube body is more Small, the response speed of flow distribution adjustment is significantly improved.

Further, the opening area of all the first openings on the outer core tube is 2-3 times the opening area of all the second openings on the inner core tube.

By adopting the above-mentioned preferred scheme, it is ensured that the adjustment range of the concentrated thermal energy is more reasonable, and the accuracy of the concentrated thermal energy adjustment can be improved.

Further, the first position adjusting mechanism includes a bracket fixed to the main body, a first screw rod mounted on the bracket through a bearing, and a first screw nut fixed to the inner core tube. The first screw rod The end is provided with a turning handle or a control motor.

Further, the second position adjusting mechanism includes a second screw rod mounted on the main body through a bearing and a second screw rod nut fixed to the outer core tube. The end of the second screw rod is provided with a rotating handle or Control the motor.

With the above-mentioned preferred solution, debugging can be performed on the spot by turning the handle; the control motor can also be connected to an electric control unit to achieve remote control, which greatly reduces the difficulty of field operation.

Further, the gas distribution adjusting mechanism includes a first gas control ring and a second gas control ring which are sleeved side by side between the main body and the inner core tube, and the first gas control ring is provided with a first blocking portion. And a first hollow part, the second air control ring is provided with a second blocking part and a second hollow part; an inner core tube provided on the inner side of the first air control ring and the second air control ring is connected to The gas inlet of the inner cavity of the inner tube; by adjusting the relative angle of the first gas control ring and the second gas control ring to change the opening size of the gas circulation port formed by the two, thereby realizing the adjustment of the gas distribution to the inner cavity of the inner tube and the main pipe Proportion of body cavity.

Further, the first gas control ring is fixed on the inner wall of the main pipe, and the second gas control ring is sleeved on the inner core tube and can rotate as the inner core tube rotates; the tail end of the inner core tube further includes An angle adjusting mechanism for adjusting the rotation angle of the inner core tube.

With the above-mentioned preferred solution, the overlapping area of the first and second barriers is changed by adjusting the relative angle of the first and second gas-control rings, that is, changing the first and second gas-control rings The size of the opening of the gas circulation port formed by the gas ring, so as to adjust the proportion of gas distributed to the inner cavity of the inner core tube and the inner cavity of the main pipe, and adjust the concentrated position of the flame thermal energy; the adjustment operation using the angle adjustment mechanism is more intuitive and convenient, and the adjustment precision ; For different applications, component parameter adjustment is more convenient and manufacturability is stronger.

Further, the inner cavity of the head of the main pipe body includes a conical conical surface, a cylindrical surface, and an expanded conical surface which are arranged in order from the inside to the outside.

Further, the length of the cylindrical surface is 20-150 mm, and the included angle between the generatrix of the externally tapered surface and the axis of the main body is 3-15 °.

Further, the length of the tapered surface of the head of the inner core tube is 10-50 mm, and the included angle between the tapered surface bus bar and the axis of the inner core tube is 5-30 °.

Further, the rotation adjustment angle of the inner core ranges from 0 to 30 degrees and 0 to 90 degrees.

By adopting the above-mentioned preferred scheme, the closing cone surface can make the gas spray out at high speed and provide high-speed heat flow, so that the air atmosphere of the heated kiln can be disturbed at high speed, thereby generating a uniform temperature field. The cylindrical surface makes the spray airflow more stable. Cooperate with the tapered surface of the inner core tube head to achieve stable adjustment of the flow rate; the included angle of the externally tapered surface is controlled at 3-15 °, and the included angle of the tapered surface of the inner core tube head is 5-30 ° Jet flames are smoother.

A flame regulating method for a low nitrogen oxide (NOx) gas burner, using the above low nitrogen oxide (NOx) gas burner, includes the following steps:

Step 1: adjust the axial position of the inner core tube relative to the main body through a first position adjusting mechanism to change the gap between the inner core tube head and the main body to achieve adjustment of the flame length;

In step 2, the gas flows into the inner cavity of the main pipe and the inner cavity of the inner core pipe are adjusted by the gas distribution adjustment mechanism to realize the centralized adjustment of the flame thermal energy.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly explain the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor.

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

2 is a schematic structural diagram of another embodiment of the present invention;

3 is a schematic structural diagram of another embodiment of the present invention;

4 is a schematic structural diagram of another embodiment of the present invention;

5 is a schematic structural diagram of another embodiment of the present invention;

FIG. 6 is a schematic structural diagram of another embodiment of the present invention.

Names of corresponding parts indicated by numbers and letters in the figure:

1- main body; 11- gas inlet; 12- first air control part; 13- second air control part; 14- closing cone surface; 15- cylindrical surface; 16- outward tensioning cone surface; 2- inner core Tube; 21-second opening; 22-gas inlet; 23-long rib; 3-outer core tube; 31-first opening; 4-first position adjustment mechanism; 41-bracket; 42-section One screw; 43-first screw nut; 44-rotation handle; 45-control motor; 5-second position adjustment mechanism; 51-second screw; 52-second screw nut; 53-rotation handle; 54-control motor; 61-first air control ring; 611-first blocking portion; 612-first hollow portion; 62-second air control ring; 621-second blocking portion; 622-second hollow portion ; 623-card slot; 7- angle adjustment mechanism.

Detailed ways

In the following, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in Figure 1, a low and low nitrogen oxide gas burner includes:

The main body 1 is provided with a gas inlet 11 on the pipe body;

The inner core tube 2 is penetrated through the inner cavity of the main body 1, the head of the inner core tube 2 is correspondingly provided in the head region of the main body 1, and the head of the inner core tube 2 is a tapered surface;

The outer core tube 3 is inserted through the inner cavity of the main body 1 and is sleeved on the outer periphery of the inner core tube 2. The head of the outer core tube 3 is provided in the inner cavity of the main body 1 and away from the head of the main body 1. The body of the tube 3 is provided with a first opening 31, and the first cavity of the main body 1 extends out of the first gas control portion 12, the first gas control portion 12 can partially block the opening of the first opening 31; The pipe body is provided with a second opening 21 that connects the inner cavity of the inner core tube 2 and the inner cavity of the outer core tube 3;

A first position adjusting mechanism 4 for adjusting the axial position of the inner core tube 2 relative to the main body 1 to change the gap between the head of the inner core tube 2 and the main body 1;

A second position adjusting mechanism 5 for adjusting the axial position of the outer core tube 3 relative to the main body to change the opening area of the first opening 31 exposed from the first gas control part 12;

A part of the gas entering from the gas inlet 11 into the inner cavity of the main pipe 1 is ejected from the opening of the main pipe 1 through the inner cavity of the main pipe 1, and the other part enters the inner core through the first opening 31 and the second opening 21 The inner cavity of the tube 2 is ejected from the opening of the head of the inner core tube 2.

The beneficial effect of adopting the above technical solution is: when the gas intake amount is constant, the first position adjustment mechanism 4 is used to change the gap between the head of the inner core tube 2 and the main body 1, that is, the total The size of the outlet changes the flow rate and controls the length of the flame jet. Under a certain flow rate, the second position adjustment mechanism 5 is used to change the amount of gas that enters the inner cavity of the core tube 2 and the main body 1 respectively, and then the thermal energy Focus on the adjustment of the position in the stream flame; it can quickly adjust the jet flame of the appropriate length to produce lower NOx emissions, and at the same time, it can easily adjust the position of the concentrated release of thermal energy in the jet flame, improving the radiation transmission rate.

As shown in FIG. 1, in other embodiments of the present invention, the head of the outer core tube 3 is a tapered surface, and the second air control portion 13 extends from the inner cavity of the main body 1. The gap of the head of the core pipe 3 forms a gas passage which is ejected from the opening of the head of the main pipe 1. The beneficial effect of adopting the above technical solution is that as the second position adjustment mechanism 5 drives the axial movement of the outer core tube 3 with respect to the main body 1, when the flow opening exposed by the first gas control portion 12 is enlarged / reduced, the second control The flow port of the gas part 13 is simultaneously reduced / expanded. The first gas control part 12 and the second gas control part 13 adjust the flow distribution into the inner tube 2 and the main cavity 1 of the main body 1 simultaneously, reducing the second In the adjustment stroke of the position adjustment mechanism 5, the volume configuration of each pipe body is smaller, and the response speed of the flow distribution adjustment is significantly improved.

In other embodiments of the present invention, the opening areas of all the first openings 31 on the outer core tube 3 are 2-3 times the opening areas of all the second openings 21 on the inner core tube 2. The beneficial effects of adopting the above technical solution are: ensuring that the adjustment range of the concentrated thermal energy is more reasonable, and the accuracy of the centralized thermal energy adjustment can be improved.

As shown in FIG. 3, in other embodiments of the present invention, the inner cavity of the head of the main pipe 1 includes a closing cone surface 14, a cylindrical surface 15, and an expanded cone surface 16 which are arranged in order from the inside to the outside; the length of the cylindrical surface 15 L2 is 20-150mm, the included angle β between the generatrix of the externally tapered surface 16 and the axis of the main body is 3-15 °; the length L1 of the cone surface of the inner core tube 2 is 10-50mm, and the generatrix The included angle α formed by the core tube axis is 5-30 °. The beneficial effect of adopting the above technical solution is that the closing cone surface 14 enables high-speed gas ejection, provides high-speed heat flow, and causes the air atmosphere of the heated kiln to be disturbed at high speed, thereby generating a uniform temperature field; the cylindrical surface 15 enables ejection. The airflow is more stable, and the flow rate can be adjusted stably in cooperation with the tapered surface of the inner core tube 2. The included angle β of the externally tapered surface 16 is controlled at 3-15 °, and the included angle of the tapered surface of the inner core tube 2 is α. It is 5-30 °, which makes the jet flame more smooth and improves the adhesion of the flame root. The adjustable length of the flame can be increased by 20% -30%.

As shown in FIGS. 1 and 2, in other embodiments of the present invention, the first position adjustment mechanism 4 includes a bracket 41 fixed to the main body 1, a first screw rod 42 mounted on the bracket 41 through a bearing, and A first lead screw nut 43 to which the inner core tube 2 is fixed, and an end of the first lead screw 42 is provided with a rotation handle 44 or a control motor 45; the second position adjusting mechanism 5 includes a second wire mounted on the main body 1 through a bearing The rod 51 and a second screw nut 52 fixed to the outer core tube 3 are provided with a rotation handle 53 or a control motor 54 at an end of the second screw rod 51. The beneficial effect of adopting the above technical solution is that debugging can be performed on the spot by turning the handle 44/53; the control motor 45/54 can also be connected to the electric control unit to realize remote control, which greatly reduces the difficulty of field operation.

As shown in FIG. 4, in other embodiments of the present invention, a low-NOx gas burner includes:

The main body 1 is provided with a gas inlet 11 on the pipe body;

The gas distribution adjustment mechanism is used to adjust the ratio of gas distribution to the inner cavity of the inner core pipe 2 and the inner cavity of the main pipe 1.

The beneficial effect of adopting the above technical solution is: when the gas intake amount is constant, the first position adjustment mechanism 4 is used to change the gap between the head of the inner core tube 2 and the main body 1, that is, the total The size of the outlet, so as to change the flow rate and control the length of the jet of flames; adjust the proportion of gas distributed to the inner cavity of the inner core tube 2 and the main cavity 1 through the gas distribution adjustment mechanism to achieve the adjustment of the position of the thermal energy concentrated in the stream; Quickly adjust the jet flame of the appropriate length to generate lower low nitrogen oxide (NOx) emissions, and at the same time, it can easily adjust the position of concentrated release of thermal energy in the jet flame, which improves the radiation transmittance.

As shown in FIG. 4-6, in other embodiments of the present invention, the gas distribution adjustment mechanism includes a first gas control ring 61 and a second gas control ring which are arranged side by side between the main body 1 and the inner core tube 2. Air ring 62. The first air control ring 61 is provided with a first blocking portion 611 and a first hollow portion 612. The second air control ring 62 is provided with a second blocking portion 621 and a second hollow portion 622. An inner gas tube 2 on the inner side of a gas control ring 61 and a second gas control ring 62 is provided with a gas sub-inlet 22 connected to the inner cavity of the inner core tube; by adjusting the first gas control ring 61 and the second gas control ring 62, The relative angle is used to change the opening size of the gas circulation port formed by the two, so as to adjust the proportion of gas distributed to the inner cavity of the inner core tube 2 and the inner cavity of the main body 1.

As shown in FIGS. 4-6, in other embodiments of the present invention, the first gas control ring 61 is fixed on the inner wall of the main body 1, the second gas control ring 62 is sleeved on the inner core tube 2, and the second gas control ring The ring groove 623 cooperates with the long rib 23 on the inner core tube; when the inner core tube 2 moves in the axial direction, the position of the second gas control ring 62 remains unchanged; when the inner core tube 2 rotates, the second The air control ring 62 rotates with the inner core tube; the tail end of the inner core tube 2 further includes an angle adjusting mechanism 7 for adjusting the rotation angle of the inner core tube. The beneficial effect of adopting the above technical solution is: by adjusting the relative angle of the first gas control ring 61 and the second gas control ring 62, the overlapping area of the first barrier portion 611 and the second barrier portion 621 is changed, that is, the first The opening size of the gas circulation port formed by the gas control ring 61 and the second gas control ring 62, so as to adjust the proportion of gas distributed to the inner cavity of the inner core tube 2 and the inner cavity of the main body 1 to achieve the adjustment of the concentrated position of the flame thermal energy; The adjustment operation of the angle adjustment mechanism 7 is more intuitive and convenient, and the adjustment accuracy is high; for different applications, the adjustment of component parameters is more convenient and the manufacturability is stronger.

A flame regulating method for a low-low-nitrogen-oxide (NOx) gas burner, using the above-mentioned low-low-nitrogen-oxide gas burner, includes the following steps:

The beneficial effect of adopting the above technical solution is that, under the condition that the gas intake amount is constant, the size of the gap between the inner core tube head and the main body is changed by the first position adjustment mechanism, that is, the total outlet size of the burner is changed. In order to change the flow velocity and control the length of the jet flame; adjust the ratio of the gas distribution to the inner cavity of the core tube and the main cavity of the main body through the gas distribution adjustment mechanism to achieve the adjustment of the position of the thermal energy concentrated in the stream flame; the jet flame of the appropriate length can be adjusted quickly The result is lower low nitrogen oxide (NOx) emissions, and at the same time, it is convenient to adjust the position of concentrated release of thermal energy in the jet flame, which improves the radiation transmittance.

The above embodiments are only for explaining the technical concept and characteristics of the present invention, and the purpose thereof is to enable those of ordinary skill in the art to understand and implement the content of the present invention, but not to limit the protection scope of the present invention. All equivalent changes or modifications should be covered by the protection scope of the present invention.

Claims

A low nitrogen oxide gas burner, comprising:

A main body with a gas inlet on its body;

An inner core tube, which is penetrated through the inner cavity of the main pipe, the head of the inner core pipe is correspondingly provided in the head region of the main pipe, and the head of the inner core pipe is a tapered surface;

A first position adjusting mechanism for adjusting an axial position of the inner core tube relative to the main body to change a gap between the inner core tube head and the main body;

The gas distribution adjustment mechanism is used to adjust the ratio of gas distribution to the inner cavity of the inner core tube and the inner cavity of the main pipe.
The low-NOx gas burner according to claim 1, wherein the gas distribution adjustment mechanism comprises:

An outer core tube that is inserted through the inner cavity of the main tube and is sleeved on the outer periphery of the inner core tube. The head of the outer core tube is provided in the inner cavity of the main tube and away from the head of the main body. A first opening, a first gas control portion extending from the inner cavity of the main pipe, the first gas control portion can partially block the opening of the first opening; the tube body of the inner core tube is provided with a communicating inner core tube; Cavity and the second opening of the inner cavity of the outer core tube;

A second position adjustment mechanism for adjusting an axial position of the outer core tube relative to the main body to change an opening area where the first opening exposes the first gas control portion;

Part of the gas entering from the gas inlet to the main body cavity is ejected from the main body cavity opening through the main body cavity, and the other part enters the inner cavity of the inner core tube through the first opening and the second opening through the inner core tube head. Squirting from the opening.
The low-NOx gas burner according to claim 2, wherein the head of the outer core tube is a tapered surface, and a second gas control portion extends from the inner cavity of the main pipe, and the second control The gap between the gas part and the head of the outer core tube forms a gas passage ejected from the opening of the head of the main body.
The low-NOx gas burner according to claim 3, wherein the opening area of all the first openings on the outer core tube is 2- to the opening area of all the second openings on the inner core tube. 3 times.
The low-NOx gas burner according to claim 2, wherein the first position adjustment mechanism comprises a bracket fixed to the main body, a first screw rod mounted on the bracket through a bearing, and an inner core. A first lead screw nut fixed with a tube, the end of the first lead screw is provided with a rotation handle or a control motor; the second position adjustment mechanism includes a second lead screw mounted on the main body through a bearing, and an outer core A second screw nut that is fixed in a tube, and the end of the second screw is provided with a rotating handle or a control motor.
The low-NOx gas burner according to claim 1, wherein the gas distribution adjusting mechanism comprises a first gas control ring and a second gas control ring which are sleeved side by side between the main body and the inner core tube. A first baffle portion and a first hollow portion are provided on the first gas control ring, and a second baffle portion and a second hollow portion are provided on the second gas control ring; The inner core tube on the inner side of the second gas control ring is provided with a gas inlet that communicates with the inner cavity of the inner core tube; the gas circulation port formed by the first gas control ring and the second gas control ring is changed by adjusting the relative angle between the first gas control ring and the second gas control ring The size of the opening is adjusted to achieve the ratio of gas distribution to the inner cavity of the inner tube and the inner cavity of the main pipe.
The low-NOx gas burner according to claim 6, wherein the first gas control ring is fixed on the inner wall of the main pipe, and the second gas control ring is sleeved on the inner core tube and can follow the inner tube. The core tube rotates and rotates; the tail end of the inner core tube further includes an angle adjustment mechanism for adjusting the rotation angle of the inner core tube, and the adjustment angle ranges from 0 to 30 degrees and 0 to 90 degrees.
The low-NOx gas burner according to claim 1, wherein the inner cavity of the head portion of the main body includes a closing cone surface, a cylindrical surface, and an expanding cone surface arranged in order from the inside to the outside, and the cylindrical surface The length of the tapered surface of the inner core tube is 10-50mm. The length of the tapered surface of the inner core tube is 10-50mm. The included angle formed by the inner tube axis is 5-30 °.
A flame regulating method for a low nitrogen oxide gas burner, characterized in that the low nitrogen oxide gas burner according to any one of claims 1 to 8 is used, comprising the following steps:

Step 1: adjust the axial position of the inner core tube relative to the main body through a first position adjusting mechanism to change the gap between the inner core tube head and the main body to achieve adjustment of the flame length;

In step 2, the gas flows into the inner cavity of the main pipe and the inner cavity of the inner core pipe are adjusted by the gas distribution adjustment mechanism to realize the centralized adjustment of the flame thermal energy.