阅读说明：本技术 一种掺烧氨气的四角切圆煤粉锅炉系统及掺氨燃烧方法 (Ammonia-doped four-corner tangential pulverized coal boiler system and ammonia-doped combustion method ) 是由 韩志江 陈文强 李月华 闫凯 于 2021-08-03 设计创作，主要内容包括：本发明提供了一种掺烧氨气的四角切圆煤粉锅炉系统及掺氨燃烧方法,涉及燃料燃烧技术领域,包括设置在锅炉上的氨气/煤粉燃烧部和氨气燃尽区；氨气/煤粉燃烧部包括煤粉燃烧区和氨气/煤粉燃烧区,氨气/煤粉燃烧区包括角上氨气/煤粉燃烧器和墙上氨气燃烧器；当氨气掺烧比例逐渐增大时,先投入墙上氨气燃烧器,后投入角上氨气/煤粉燃烧器；先投入上层的角上氨气/煤粉燃烧器和/或墙上氨气燃烧器,后投入下层的角上氨气/煤粉燃烧器和/或墙上氨气燃烧器；本发明通过控制煤粉燃烧区中煤粉处于非完全燃烧状态,为上层的氨气/煤粉燃烧区进行氨气燃烧时提供CO,使氨气更易于燃烧,在氨气燃尽区的上方设置SOFA区和SNCR脱硝设备,可降低NOx的排放。(The invention provides an ammonia-doped tangential firing pulverized coal boiler system and an ammonia-doped firing method, which relate to the technical field of fuel firing and comprise an ammonia/pulverized coal firing part and an ammonia burnout area which are arranged on a boiler; the ammonia/coal powder combustion part comprises a coal powder combustion area and an ammonia/coal powder combustion area, and the ammonia/coal powder combustion area comprises an ammonia/coal powder burner on the corner and an ammonia burner on the wall; when the ammonia blending combustion proportion is gradually increased, firstly putting the ammonia burner on the wall, and then putting the ammonia/pulverized coal burner on the corner; firstly putting the ammonia gas/pulverized coal burner on the upper corner and/or the ammonia gas burner on the wall, and then putting the ammonia gas/pulverized coal burner on the lower corner and/or the ammonia gas burner on the wall; according to the invention, the pulverized coal in the pulverized coal combustion area is controlled to be in a non-complete combustion state, CO is provided for the upper ammonia gas/pulverized coal combustion area during ammonia gas combustion, so that the ammonia gas is easier to combust, and the SOFA area and the SNCR denitration equipment are arranged above the ammonia gas burnout area, so that the emission of NOx can be reduced.)

1. A four-corner tangential pulverized coal boiler system doped with ammonia gas is characterized by comprising an ammonia gas/pulverized coal combustion part (1) and an ammonia gas burnout area (2) which are sequentially arranged on a boiler from bottom to top;

the ammonia/coal powder combustion part (1) comprises a coal powder combustion area (6) and an ammonia/coal powder combustion area (5), and the coal powder combustion area (6) is positioned below the ammonia/coal powder combustion area (5);

the ammonia/pulverized coal combustion area (5) comprises an ammonia/pulverized coal burner (5-1) arranged on a corner of a boiler wall and a wall ammonia burner (5-2) arranged on the boiler wall.

2. The ammonia-doped tangential firing pulverized coal fired boiler system as defined in claim 1, wherein the number of the ammonia/pulverized coal fired sections (1) is two or more, and the installation height of the ammonia/pulverized coal burners (5-1) on the boiler at the corners is the same as the installation height of the ammonia burners (5-2) on the boiler at the walls.

3. The ammonia gas doped tangential firing pulverized coal boiler system as defined in claim 1, wherein a SOFA area (3) is arranged above the ammonia gas burnout area (2), an SNCR denitration device (4) for denitration is arranged above the SOFA area (3), and pulverized coal burners (5-3) are arranged on the ammonia gas burnout area (2) and the pulverized coal combustion area (6) on the boiler.

4. The ammonia gas doped tangential firing pulverized coal boiler system as defined in claim 2, wherein the ammonia gas/pulverized coal burner (5-1) at the corner comprises a fuel channel (5-11), a plasma igniter (5-14), a first sleeve (5-15) and a second sleeve (5-16), the fuel channel (5-11) is a hollow cylindrical structure with two open ends, one end of the fuel channel is connected with the primary air duct (5-12), and the other end of the fuel channel is connected with the boiler;

the first sleeve (5-15) and the second sleeve (5-16) are fixedly arranged inside the fuel channel (5-11), the second sleeve (5-16) is fixedly arranged on one side, close to the boiler, in the fuel channel (5-11), the first sleeve (5-15) is fixedly arranged at one end, far away from the boiler, of the second sleeve (5-16), the first sleeve (5-15) and the second sleeve (5-16) are in hollow cylindrical structures with two open ends, the outer diameter of the first sleeve (5-15) is smaller than the inner diameter of the second sleeve (5-16), the first sleeve (5-15) is connected with a first combustion improver pipeline (5-17), and the second sleeve (5-16) is connected with a second combustion improver pipeline (5-18), the ignition end of the plasma igniter (5-14) is communicated into the first sleeve (5-15), and the fuel channel (5-11) is connected with the ammonia gas pipeline (5-13).

5. The ammonia gas doped tangential firing pulverized coal boiler system as defined in claim 2, wherein the ammonia gas/pulverized coal burner (5-1) at the corner comprises a fuel channel (5-11), a plasma igniter (5-14), a first sleeve (5-15), a second sleeve (5-16), a primary ammonia gas pipeline (5-21), a secondary ammonia gas pipeline (5-22) and a tertiary ammonia gas pipeline (5-23), the fuel channel (5-11) is a hollow cylindrical structure with openings at two ends, one end is connected with the primary air pipeline (5-12), and the other end is connected with the boiler;

the first sleeve (5-15) and the second sleeve (5-16) are fixedly arranged inside the fuel channel (5-11), the second sleeve (5-16) is fixedly arranged at one side of the fuel channel (5-11) close to the boiler, the first sleeve (5-15) is fixedly arranged at one end of the second sleeve (5-16) far away from the boiler, the first sleeve (5-15) and the second sleeve (5-16) are in the shape of hollow cylindrical structures with two open ends, the outer diameter of the first sleeve (5-15) is smaller than the inner diameter of the second sleeve (5-16), the ignition end of the plasma igniter (5-14) is communicated into the first sleeve (5-15), and the fuel channel (5-11) is connected with the combustion improver pipeline (5-20).

6. An ammonia-doped corner-tangent-circle pulverized coal boiler system as claimed in claim 5, characterized in that said first sleeve (5-15) is connected to said primary ammonia conduit (5-21), the nozzle of said primary ammonia conduit (5-21) is located inside said first sleeve (5-15), the nozzle of said secondary ammonia conduit (5-22) is located in the gap between said first sleeve (5-15) and said second sleeve (5-16), and the nozzle of said tertiary ammonia conduit (5-23) is located in the gap between said second sleeve (5-16) and said fuel channel (5-11).

7. An ammonia-doped corner-tangent-circle pulverized-coal boiler system as claimed in any one of claims 4 to 6, characterized in that a peripheral air duct (5-19) is provided at one end of the fuel passage (5-11) outside and close to the boiler, said peripheral air duct (5-19) being connected to the boiler.

8. The ammonia-doped tangential firing pulverized coal boiler system as claimed in claim 4, wherein the combustion improver in the first combustion improver pipeline (5-17) and the second combustion improver pipeline (5-18) is oxygen-enriched air, wherein the volume proportion of oxygen is 25% -35%.

9. The ammonia-doped tangential firing pulverized coal fired boiler system as defined in claim 5 or 6, wherein the combustion improver in the combustion improver pipeline (5-20) is oxygen-enriched air, wherein the volume ratio of oxygen is 25% -35%.

10. The method for carrying out ammonia-doped combustion by using the ammonia-doped tangential firing pulverized coal boiler system as defined in any one of claims 1 to 6 and 8, wherein when the ammonia gas doping proportion is 0-20%, all or part of the wall ammonia gas burners (5-2) are opened for ammonia gas combustion, and the corner ammonia gas/pulverized coal burners (5-1) are opened for pulverized coal combustion;

and when the ammonia gas blending combustion ratio is 20-60%, opening all or part of the corner ammonia gas/pulverized coal burners (5-1) to perform ammonia gas combustion.

Technical Field

The invention belongs to the technical field of fuel combustion, and particularly relates to an ammonia-doped corner tangential pulverized coal boiler system and an ammonia-doped combustion method.

Background

In recent years, the global economy trend of ' low carbon ' is increasingly strengthened, and each main economy in the world is successively added with ' Paris ' agreement ', and corresponding carbon emission reduction targets and plans are formulated. As the second major economic body in the world, China sets up a carbon emission peak reaching action scheme before 2030 years, strives for reaching a peak value before 2030 years, and realizes carbon neutralization before 2060 years. The utilization of 'zero carbon' fuel instead of traditional fossil fuel is one of the effective carbon emission reduction modes.

The coal powder combustion technology is widely applied, the research on the combustion characteristic and the NOx emission characteristic is tested by long-term engineering practice at home and abroad, and the relevant technology is mature, but the problem of reducing the carbon emission of the coal powder combustion technology needs to be considered when the coal powder combustion technology faces the trend of low carbonization. Ammonia gas (NH)₃) Is a good carrier of hydrogen energy compared with hydrogen gas (H)₂) The main advantages of ammonia are high hydrogen content and high volumetric energy density, which are even higher per unit volume than liquid hydrogen. Meanwhile, the fuel is easy to liquefy, convenient to store and transport, high in safety and the like due to the mature production process, is considered to be a more potential clean fuel, and can be effectively used as a carrier of hydrogen and energy. However, there are two very significant problems associated with its direct combustion as a fuel: poor combustion characteristics and high NOx emissions.

At present, most of research on ammonia gas combustion is concentrated on an internal combustion engine and a pulverized coal cyclone burner, and the technology development for blending and burning ammonia gas in a four-corner tangential pulverized coal boiler is less, and the technology development for blending and burning ammonia gas in a large proportion is less and less, so that the provision of the four-corner tangential pulverized coal boiler system for blending and burning ammonia gas and the ammonia-blending combustion method are very important.

Disclosure of Invention

The invention aims to provide an ammonia-doped tangential firing pulverized coal boiler system and an ammonia-doped combustion method, which aim to solve the problems in the background technology.

In order to solve the technical problem, the invention provides an ammonia-doped tangential pulverized coal boiler system, which comprises an ammonia/pulverized coal combustion part and an ammonia burnout area, wherein the ammonia/pulverized coal combustion part and the ammonia burnout area are sequentially arranged on a boiler from bottom to top;

the ammonia/coal powder combustion part comprises a coal powder combustion area and an ammonia/coal powder combustion area, and the coal powder combustion area is positioned below the ammonia/coal powder combustion area;

the ammonia/pulverized coal combustion area comprises an ammonia/pulverized coal burner arranged on a corner of a boiler wall and a wall ammonia burner arranged on the boiler wall.

The laminar flame combustion speed of ammonia gas is low, and experimental research shows that CO and H₂When the gas and the ammonia gas are combusted together, the combustion speed of the laminar flame of the ammonia gas can be effectively improved, so that the ammonia gas is easier to combust. Therefore, the pulverized coal combustion area is arranged below the ammonia/pulverized coal combustion area, so that the pulverized coal combustion area is in a lean combustion state, the purpose is to provide CO for the ammonia/pulverized coal combustion area at the upper layer when ammonia combustion is carried out, the combustion of ammonia is promoted, a large amount of heat is provided for the ammonia combustion at the upper layer, and the combustion of ammonia is facilitated when the temperature of a hearth is higher.

The upper part of the boiler is provided with an ammonia burnout zone, which aims to ensure the complete combustion of ammonia.

The invention mainly describes the parts for realizing ammonia-doped combustion in the four-corner tangential pulverized coal boiler, does not describe other related accessories on the boiler too much, and is common knowledge in the field.

Furthermore, the number of the ammonia/pulverized coal combustion parts is more than two, and the installation height of the ammonia/pulverized coal burner on the boiler at the corner is the same as the installation height of the ammonia burner on the boiler on the wall.

The guard burning zone is arranged on the furnace wall of the ammonia gas spraying place, if the heights of the guard burning zone are different, the arrangement area of the guard burning zone is too large, when the mixed burning amount of ammonia gas is small, most of the area where the guard burning zone is arranged is pulverized coal burning, the temperature of a hearth is too high, the generation amount of thermal NOx is more, and therefore the installation height of the ammonia gas/pulverized coal burner on the boiler at a corner is the same as the installation height of the ammonia gas burner on the boiler on the wall.

The arrangement of the plurality of ammonia/pulverized coal combustion parts aims to prevent the ammonia from being burnt difficultly due to the fact that the temperature of a hearth is locally too low when the ammonia is intensively mixed and burnt in a large proportion.

The wall ammonia gas burner is used for ammonia gas combustion quantity when less, so a plasma igniter is not needed, the combustion improver is high-temperature secondary air, ammonia gas and secondary air are mixed and then put into a hearth, the wall ammonia gas burner is not limited to be arranged in the middle of a hearth wall, but also can be arranged at other positions, but the two wall ammonia gas burners on opposite surfaces are in central symmetry relation, and an included angle between the wall ammonia gas burner and the hearth wall can adopt a vertical hearth wall as required, or along the rotating direction of a coal powder tangent circle, or against the rotating direction of the coal powder tangent circle.

When ammonia is combusted in the corner ammonia/pulverized coal burner and/or the wall ammonia burner, it is first heated to the same temperature as the combustion improver and then mixed with the combustion improver.

Furthermore, a SOFA area is arranged above the ammonia burnout area, SNCR denitration equipment for denitration is arranged above the SOFA area, and pulverized coal burners are arranged on the ammonia burnout area and the pulverized coal combustion area on the boiler.

An SNCR denitration device is arranged at the upper part of the hearth, and the purpose is to reduce NOx.

The SOFA area is a separated over-fire air area, and the main combustion area of the combustor is in a lean combustion state by means of graded air supply, so that the flame temperature is reduced, the generation of thermal NOx can be reduced, and meanwhile, the sufficient combustion of coal powder can be ensured.

Further, the ammonia gas/pulverized coal burner on the corner comprises a fuel channel, a plasma igniter, a first sleeve and a second sleeve, wherein the fuel channel is of a hollow cylindrical structure with two open ends, one end of the fuel channel is connected with a primary air pipeline, and the other end of the fuel channel is connected with a boiler;

the utility model discloses a plasma igniter, including first sleeve, second sleeve, first sleeve and second combustion improver pipeline connection, first sleeve with the equal fixed mounting of second sleeve in the inside of fuel passageway one side fixed mounting who is close to the boiler in the fuel passageway the second sleeve one end fixed mounting that the boiler was kept away from to the second sleeve the first sleeve, first sleeve with the telescopic shape of second is both ends open-ended hollow cylindric structure, first telescopic external diameter is less than the telescopic internal diameter of second, first sleeve and first combustion improver pipeline connection, the second sleeve is connected with the second combustion improver pipeline, the ignition end of plasma igniter lets in first telescopic inside, fuel passageway and ammonia pipe connection.

Further, another design mode of the ammonia gas/pulverized coal burner on the corner is that the burner comprises a fuel channel, a plasma igniter, a first sleeve, a second sleeve, a primary ammonia gas pipeline, a secondary ammonia gas pipeline and a tertiary ammonia gas pipeline, wherein the fuel channel is of a hollow cylindrical structure with two open ends, one end of the fuel channel is connected with a primary air pipeline, and the other end of the fuel channel is connected with a boiler;

the utility model discloses a plasma igniter, including first sleeve, second sleeve, combustion improver pipeline, first sleeve with the equal fixed mounting of second sleeve in the inside of fuel passage one side fixed mounting who is close to the boiler in the fuel passage the second sleeve one end fixed mounting that the boiler was kept away from to the second sleeve the first sleeve, first sleeve with the telescopic shape of second is both ends open-ended hollow cylindric structure, first sleeve's external diameter is less than the telescopic internal diameter of second, the ignition end of plasma igniter lets in first telescopic inside, fuel passage and combustion improver pipeline connection.

Further, the first sleeve is connected with the primary ammonia pipeline, a nozzle of the primary ammonia pipeline is located inside the first sleeve, a nozzle of the secondary ammonia pipeline is located in a gap between the first sleeve and the second sleeve, and a nozzle of the tertiary ammonia pipeline is located in a gap between the second sleeve and the fuel channel.

Further, a peripheral air duct is provided outside the fuel passage and near one end of the boiler, and the peripheral air duct is connected to the boiler.

Furthermore, the combustion improver in the first combustion improver pipeline and the second combustion improver pipeline is oxygen-enriched air, and the volume ratio of oxygen is 25-35%.

Furthermore, the combustion improver in the combustion improver pipeline is oxygen-enriched air, wherein the volume ratio of oxygen is 25-35%.

The method for carrying out ammonia-doped combustion by using the pulverized coal boiler system for doping and combusting ammonia gas with tangential circles at four corners comprises the steps of opening all or part of wall ammonia gas burners for ammonia gas combustion when the ammonia gas doping and combusting ratio is 0-20%, and opening the ammonia gas/pulverized coal burners at the corners for pulverized coal combustion;

and when the ammonia gas blending combustion ratio is 20-60%, opening all or part of the corner ammonia gas/pulverized coal burners to perform ammonia gas combustion.

The blending proportion of the ammonia gas is calculated according to the lower calorific value generated by fuel combustion.

Has the advantages that:

(1) the invention provides an ammonia-doped tangential firing pulverized coal boiler system, which comprises an ammonia/pulverized coal combustion part and an ammonia burnout area which are sequentially arranged on a boiler from bottom to top; the ammonia/coal powder combustion part comprises a coal powder combustion area and an ammonia/coal powder combustion area, and the ammonia/coal powder combustion area comprises an ammonia/coal powder burner arranged on the corner of the wall corner of the boiler and a wall ammonia burner arranged on the wall surface of the boiler; the pulverized coal is controlled to be in a non-complete combustion state in the pulverized coal combustion area, more CO is provided for the ammonia/pulverized coal combustion area on the upper layer when ammonia is combusted, the ammonia is easier to combust, a burning prevention belt is laid on a furnace wall where the ammonia/pulverized coal combustion area of the boiler is located, the temperature of a combustion area is guaranteed, the ammonia burnout area is arranged on the upper part of the boiler, the complete combustion of the ammonia is guaranteed, the SOFA area is arranged above the ammonia burnout area, the generation of thermal NOx can be reduced, and the emission of NOx in a hearth can be reduced by arranging the SNCR denitration equipment.

(2) According to the ammonia-doped tangential firing pulverized coal boiler system, the arrangement of the plurality of ammonia/pulverized coal combustion parts can prevent ammonia from being difficult to combust due to the fact that the temperature of a hearth is locally too low when ammonia is intensively combusted in a large proportion, the pulverized coal combustion area is arranged below the ammonia/pulverized coal combustion area, the pulverized coal combustion area is controlled to be in a lean combustion state, CO can be provided for the ammonia/pulverized coal combustion area at the upper layer when ammonia is combusted, the combustion of ammonia is promoted, meanwhile, a large amount of heat is provided for the ammonia combustion at the upper layer, and the combustion of ammonia is facilitated when the temperature of the hearth is high.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

FIG. 1 is a schematic structural diagram of an ammonia-doped tangential firing pulverized coal boiler system;

FIG. 2 is a schematic diagram of the arrangement of the corner ammonia/pulverized coal burners and the wall ammonia burners in the ammonia/pulverized coal combustion zone of a boiler according to the present invention;

FIG. 3 is a schematic view showing an alternative arrangement of the corner ammonia/pulverized coal burners and the wall ammonia burners in the ammonia/pulverized coal combustion zone of the boiler according to the present invention;

FIG. 4 is a schematic view of the configuration of an ammonia/pulverized coal burner in a middle corner of an embodiment;

FIG. 5 is a schematic view showing the structure of an ammonia gas/pulverized coal burner in the middle corner of the second embodiment;

description of the drawings:

1. an ammonia/pulverized coal combustion part; 2. an ammonia burnout zone; 3. a SOFA region; 4. SNCR denitration equipment; 5. an ammonia/coal powder combustion zone; 6. a pulverized coal combustion zone; 5-1, ammonia gas/pulverized coal burner on the corner; 5-11, fuel channel; 5-12, primary air pipeline; 5-13 parts of ammonia gas pipeline; 5-14, plasma igniter; 5-15, a first sleeve; 5-16, a second sleeve; 5-17, a first oxidant conduit; 5-18, a second oxidant conduit; 5-19, perimeter air ducts; 5-20 parts of combustion improver pipeline; 5-21, a primary ammonia pipeline; 5-22, a secondary ammonia pipeline; 5-23, a three-stage ammonia pipeline; 5-2, a wall ammonia gas burner; 5-3, pulverized coal burner;

the dashed lines in the drawings are additional lines added to better describe the structure of the present application and do not actually exist.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.

In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views. The size and thickness of each component shown in the drawings are arbitrarily illustrated, and the present invention is not limited to the size and thickness of each component. The thickness of the components may be exaggerated where appropriate in the figures to improve clarity.

Example 1:

as shown in fig. 1 and 2, in a preferred embodiment, an ammonia-doped tangential firing pulverized coal boiler system is provided, which comprises an ammonia/pulverized coal combustion part 1 and an ammonia burnout zone 2, which are sequentially arranged on a boiler from bottom to top;

the ammonia/coal powder combustion part 1 comprises a coal powder combustion area 6 and an ammonia/coal powder combustion area 5, and the coal powder combustion area 6 is positioned below the ammonia/coal powder combustion area 5;

the ammonia/pulverized coal combustion area 5 comprises an ammonia/pulverized coal burner 5-1 arranged on a corner of a boiler wall and an ammonia burner 5-2 arranged on a wall of the boiler wall.

The laminar flame combustion speed of ammonia gas is low, and experimental research shows that CO and H₂When the gas and the ammonia gas are combusted together, the combustion speed of the laminar flame of the ammonia gas can be effectively improved, so that the ammonia gas is easier to combust. Therefore, the pulverized coal combustion area 6 is arranged below the ammonia/pulverized coal combustion area 5, and the pulverized coal combustion area 6 is controlled to be in a lean combustion state, so that CO is provided for the ammonia/pulverized coal combustion area 5 at the upper layer when ammonia is combusted, the combustion of ammonia is promoted, a large amount of heat is provided for the ammonia combustion at the upper layer, and the combustion of ammonia is facilitated when the temperature of a hearth is higher.

An ammonia burnout zone 2 is arranged at the upper part of the boiler, and aims to ensure the complete combustion of ammonia.

The invention mainly describes components for realizing ammonia-doped combustion in a four-corner tangential pulverized coal boiler, does not describe other related accessories on the boiler too much, is common knowledge in the field, and in addition, the boiler is divided into different areas in order to clearly describe the technical scheme of the application.

In the embodiment, the number of the ammonia/pulverized coal combustion parts 1 is two, each ammonia/pulverized coal combustion part 1 comprises four ammonia/pulverized coal burners 5-1 arranged on corners of a boiler wall and four ammonia burners 5-2 arranged on walls of the boiler wall, the four ammonia/pulverized coal burners 5-1 on the corners are respectively positioned on four corners of the ammonia/pulverized coal combustion area 5 of the boiler, the four ammonia burners 5-2 on the walls are respectively positioned on the middle positions of the front, the rear, the left and the right walls of the ammonia/pulverized coal combustion area 5 of the boiler, the installation height of the ammonia gas/pulverized coal burner 5-1 on the corner of each ammonia gas/pulverized coal combustion area 5 on the boiler is the same as the installation height of the ammonia gas burner 5-2 on the wall on the boiler.

The guard burning zone is arranged on the furnace wall of the ammonia gas spraying place, if the heights of the guard burning zone are different, the arrangement area of the guard burning zone is too large, when the ammonia gas mixed burning amount is small, most of the area where the guard burning zone is arranged is pulverized coal burning, the temperature of a hearth is too high, the generation amount of thermal NOx is large, and therefore the installation height of the ammonia gas/pulverized coal burner 5-1 on a corner on a boiler is the same as the installation height of the ammonia gas burner 5-2 on the wall on the boiler. .

The arrangement of the plurality of ammonia/pulverized coal combustion parts 1 aims to prevent the ammonia from being burnt difficultly due to the fact that the temperature of a hearth is locally too low when the ammonia is intensively mixed and burnt in a large proportion.

And a burning guarding belt is arranged on the furnace wall where the ammonia gas/coal powder burning part 1 is positioned.

An ammonia/coal powder combustion area 5 is provided with ammonia/coal powder burners 5-1 at four corners and four wall ammonia burners 5-2, when the ammonia gas burner 5-2 on the wall is used for the ammonia gas combustion, so when the combustion amount is less, a plasma igniter is not needed, the combustion improver is high-temperature overgrate air, the ammonia gas and the overgrate air are mixed and then put into a hearth, the mixture is not only arranged in the middle of the hearth wall, but also can be arranged at other positions, but the two wall ammonia burners 5-2 on opposite surfaces are in central symmetry, and an included angle between the wall ammonia burner 5-2 and the hearth wall can be vertical to the hearth wall as required, or along the rotation direction of the coal powder tangent circle, or against the rotation direction of the coal powder tangent circle.

As shown in FIG. 2, in this example, the wall ammonia gas burner 5-2 is arranged at the middle position of the furnace wall, and the included angle between the wall ammonia gas burner 5-2 and the furnace wall is 90 degrees.

When ammonia is combusted in the corner ammonia/pulverized coal burner 5-1 and/or the wall ammonia burner 5-2, it is first heated to the same temperature as the combustion improver and then mixed with the combustion improver.

An SOFA area 3 is arranged above the ammonia burnout area 2, an SNCR denitration device 4 for denitration is arranged above the SOFA area 3, and pulverized coal burners 5-3 are arranged on the ammonia burnout area 2 and the pulverized coal combustion area 6 on the boiler.

The ammonia burnout zone 2 and the pulverized coal burners 5-3 on the pulverized coal combustion zone 6 are positioned on four corners of a boiler, wherein the pulverized coal burners 5-3 on the pulverized coal combustion zone 6 can be arranged in multiple stages on the corners of the boiler along the height direction of the boiler, each stage comprises four pulverized coal burners 5-3, in the embodiment, the pulverized coal burners 5-3 in the pulverized coal combustion zone 6 on the upper part of the boiler are designed into one stage, namely four pulverized coal burners 5-3 respectively positioned on the corners of the boiler are arranged, and the pulverized coal burners 5-3 in the pulverized coal combustion zone 6 on the lower part of the boiler are designed into two stages, namely eight pulverized coal burners 5-3 respectively positioned on the corners of the boiler are arranged.

An SNCR denitration device is arranged at the upper part of the hearth, and the purpose is to reduce NOx.

The SOFA area 3 is a separated over-fire air area, and the main combustion area of the combustor is in a lean combustion state by means of graded air supply, so that the flame temperature is reduced, the generation of thermal NOx can be reduced, and meanwhile, the sufficient combustion of coal powder can be ensured.

In this embodiment, as shown in fig. 4, in this embodiment, the ammonia gas/pulverized coal burner 5-1 at the corner is designed to have a structure including a fuel channel 5-11, a plasma igniter 5-14, a first sleeve 5-15 and a second sleeve 5-16, where the fuel channel 5-11 is a hollow cylindrical structure with two open ends, one end of the fuel channel is connected to the primary air duct 5-12, and the other end of the fuel channel is connected to the boiler; the fuel passages 5 to 11 are L-shaped.

The first sleeve 5-15 and the second sleeve 5-16 are both fixedly arranged inside the fuel channel 5-11, the second sleeve 5-16 is fixedly arranged on one side of the fuel channel 5-11 close to the boiler, the first sleeve 5-15 is fixedly arranged on one end of the second sleeve 5-16 far away from the boiler, the first sleeve 5-15 and the second sleeve 5-16 are in hollow cylindrical structures with two open ends, the outer diameter of the first sleeve 5-15 is smaller than the inner diameter of the second sleeve 5-16, the first sleeve 5-15 is connected with a first oxidant pipeline 5-17, the second sleeve 5-16 is connected with a second oxidant pipeline 5-18, the ignition end of the plasma igniter 5-14 is communicated with the inside of the first sleeve 5-15, the fuel channel 5-11 is connected with an ammonia gas pipeline 5-13.

The ammonia in the ammonia pipeline 5-13 is sprayed from one end of the first sleeve 5-15 far away from the boiler, then is mixed with the combustion improver sprayed from the first combustion improver pipeline 5-17, and is ignited by the plasma igniter 5-14 to complete the first-stage combustion; ammonia gas entering from the gap between the first sleeve 5-15 and the second sleeve 5-16 is supplemented into the second sleeve 5-16 and mixed with combustion improver sprayed from the second combustion improver pipeline 5-18 to complete second-stage combustion; and finally, the ammonia gas entering from the gap between the fuel channel 5-11 and the second sleeve 5-16 is supplemented into the hearth and mixed with the combustion improver sprayed from the peripheral air pipeline 5-19 to finish the third-stage combustion.

Outside the fuel channels 5-11 and near one end of the boiler, a peripheral air duct 5-19 is arranged, which peripheral air duct 5-19 is connected to the boiler.

The combustion improver in the first combustion improver pipeline 5-17, the second combustion improver pipeline 5-18 and the peripheral air pipeline 5-19 is oxygen-enriched air, wherein the volume ratio of oxygen is 25-35%.

As shown in fig. 4, an end portion of the first sleeve 5-15 close to the boiler is located inside an end of the second sleeve 5-16 remote from the boiler;

the method for carrying out ammonia-doped combustion by utilizing the ammonia-doped tangential coal powder boiler system comprises the steps of opening all or part of the wall ammonia gas burner 5-2 to carry out ammonia gas combustion when the ammonia gas doping combustion proportion is 0-20%, closing the ammonia gas pipeline 5-13, the first combustion improver pipeline 5-17 and the second combustion improver pipeline 5-18 of the ammonia gas/coal powder burner 5-1 at the corner, opening the primary air pipeline 5-12 and the peripheral air pipeline 5-19, and igniting by using the plasma igniter 5-14 to carry out coal powder combustion;

and when the ammonia gas blending combustion ratio is 20-60%, opening all or part of the ammonia gas pipeline 5-13, the first combustion improver pipeline 5-17, the second combustion improver pipeline 5-18 and the peripheral air pipeline 5-19 of the ammonia gas/pulverized coal burner 5-1 at the corner for ammonia gas combustion.

In the figure 4, the ammonia-removing pipeline 5-13, the first combustion improver pipeline 5-17 and the second combustion improver pipeline 5-18 are shown, and the rest is the structure of a direct-flow burner of a conventional thermal power boiler, wherein the direct-flow burner comprises a plasma igniter 5-14, a first sleeve 5-15, a second sleeve 5-16, a primary air pipeline 5-12 and a peripheral air pipeline 5-19.

When the ammonia gas/pulverized coal burner 5-1 at the corner burns pulverized coal, opening the primary air pipeline 5-12, introducing primary air and pulverized coal, and closing the ammonia gas pipeline 5-13, the first combustion improver pipeline 5-17 and the second combustion improver pipeline 5-18; when the ammonia gas/pulverized coal burner 5-1 at the corner burns ammonia gas, the primary air pipeline 5-12 is closed, the ammonia gas pipeline 5-13, the first combustion improver pipeline 5-17, the second combustion improver pipeline 5-18 and the peripheral air pipeline 5-19 are opened, and the combustion improver is used by peripheral air.

Also, in this embodiment, the angular ammonia/pulverized coal burner 5-1 cannot perform ammonia combustion and pulverized coal combustion at the same time. When the ammonia gas and the coal powder are combusted, the plasma igniters 5-14 are used for ignition and combustion.

The mode of ammonia injection combustion of the ammonia gas/pulverized coal burner 5-1 on the corner is that the ammonia gas enters the first sleeve 5-15 through the ammonia gas pipeline 5-13 and is mixed with the combustion improver in the first combustion improver pipeline 5-17 in the first sleeve 5-15, the overall air coefficient of the position is 1.1-1.5, ignition and combustion of the ammonia gas in the first sleeve 5-15 can be promoted by utilizing a high-temperature fire core generated by plasma and the oxygen-enriched condition of the combustion improver at the temperature of 4000-10000 ℃, and meanwhile, a certain amount of combustion improver is supplemented in the second sleeve 5-16 to promote stable combustion of the ammonia gas.

When the ammonia gas/pulverized coal burner 5-1 at the corner burns pulverized coal, the whole air coefficient in the primary air pipeline 5-12 is controlled to be less than 1, the generation of a large amount of NOx can be inhibited, and the residual air enters a hearth through afterburning air and secondary air.

The wall ammonia gas burner 5-2 and the corner ammonia gas/pulverized coal burner 5-1 are specifically put into the wall ammonia gas burner 5-2 firstly and then the corner ammonia gas/pulverized coal burner 5-1 in priority when the ammonia gas blending proportion is gradually increased; when a plurality of ammonia/pulverized coal combustion parts 1 are arranged, firstly, the ammonia/pulverized coal burner 5-1 on the upper layer corner and/or the ammonia burner 5-2 on the wall are/is put into the ammonia/pulverized coal burner 5-1 on the lower layer corner and/or the ammonia burner 5-2 on the wall.

When the ammonia gas blending combustion proportion is 20-60%, the priority is that the ammonia gas/pulverized coal burner 5-1 on the upper layer corner and/or the ammonia gas burner 5-2 on the wall are firstly put into, and then the ammonia gas/pulverized coal burner 5-1 on the lower layer corner and/or the ammonia gas burner 5-2 on the wall are put into; however, the upper corner ammonia gas/pulverized coal burner 5-1 and/or the wall ammonia gas burner 5-2 are not required to be put into use when being put into use, and the lower corner ammonia gas/pulverized coal burner 5-1 and/or the wall ammonia gas burner 5-2 are/is required to be put into use, for example, in special cases, the lower corner ammonia gas burner 5-2 is put into use first, and then the upper corner ammonia gas/pulverized coal burner 5-1 is put into use.

The blending proportion of the ammonia gas is calculated according to the lower calorific value generated by fuel combustion.

The air factor is defined as the ratio of the amount of air actually supplied to the amount of air theoretically required.

Example 2:

as shown in FIGS. 1 and 3, the main difference between this embodiment and embodiment 1 is that the wall ammonia gas burner 5-2 is disposed at a position other than the middle of the furnace wall, but the two wall ammonia gas burners 5-2 on the opposite surfaces are in a central symmetry relationship.

As shown in fig. 5, another design manner of the ammonia gas/pulverized coal burner 5-1 at the corner is that the burner comprises a fuel channel 5-11, a plasma igniter 5-14, a first sleeve 5-15, a second sleeve 5-16, a primary ammonia gas pipeline 5-21, a secondary ammonia gas pipeline 5-22 and a tertiary ammonia gas pipeline 5-23, wherein the fuel channel 5-11 is a hollow cylindrical structure with two open ends, one end of the fuel channel is connected with a primary air pipeline 5-12, and the other end of the fuel channel is connected with a boiler;

the first sleeve 5-15 and the second sleeve 5-16 are both fixedly installed inside the fuel channel 5-11, the second sleeve 5-16 is fixedly installed on one side, close to the boiler, inside the fuel channel 5-11, the first sleeve 5-15 is fixedly installed on one end, far away from the boiler, of the second sleeve 5-16, the first sleeve 5-15 and the second sleeve 5-16 are in hollow cylindrical structures with two open ends, the outer diameter of the first sleeve 5-15 is smaller than the inner diameter of the second sleeve 5-16, the ignition end of the plasma igniter 5-14 is communicated with the inside of the first sleeve 5-15, and the fuel channel 5-11 is connected with the oxidant pipeline 5-20.

The first sleeve 5-15 is connected with the primary ammonia gas pipeline 5-21, the nozzle of the primary ammonia gas pipeline 5-21 is positioned inside the first sleeve 5-15, the nozzle of the secondary ammonia gas pipeline 5-22 is positioned in the gap between the first sleeve 5-15 and the second sleeve 5-16, and the nozzle of the tertiary ammonia gas pipeline 5-23 is positioned in the gap between the second sleeve 5-16 and the fuel channel 5-11. The secondary ammonia gas pipeline 5-22 and the tertiary ammonia gas pipeline 5-23 both penetrate through the fuel channel 5-11.

Outside the fuel channels 5-11 and near one end of the boiler, a peripheral air duct 5-19 is arranged, which peripheral air duct 5-19 is connected to the boiler.

The combustion improver in the combustion improver pipeline 5-20 and the peripheral air pipeline 5-19 is oxygen-enriched air, wherein the volume ratio of oxygen is 25-35%.

The ammonia gas sprayed out of the primary ammonia gas pipeline 5-21 is sprayed into the first sleeve 5-15 to be mixed with the combustion improver sprayed out of the combustion improver pipeline 5-20, and the plasma igniter 5-14 is used for ignition to complete primary combustion; then, the ammonia gas sprayed out of the secondary ammonia gas pipeline 5-22 is mixed with a combustion improver in a second sleeve 5-16, and secondary combustion is completed by utilizing the primary flame; and finally, mixing the ammonia gas sprayed out of the three-stage ammonia gas pipelines 5-23 with a combustion improver sprayed out of the combustion-supporting pipeline, and finishing the third-stage combustion by using the second-stage flame.

In the embodiment, the combustion improver is intensively fed into the fuel channel 5-11 through the combustion improver pipeline 5-20, and ammonia gas is sprayed in three stages to realize three-stage combustion of the ammonia gas, while in the embodiment 1, the ammonia gas is intensively fed into the combustion channel through the ammonia gas pipeline, and the combustion improver is sprayed in three stages to realize three-stage combustion of the ammonia gas.

The method for carrying out ammonia-doped combustion by utilizing the ammonia-doped tangential coal powder boiler system comprises the steps of opening all or part of the ammonia gas burner 5-2 on the wall to carry out ammonia gas combustion when the ammonia gas doping combustion proportion is 0-20%, closing the combustion improver pipeline 5-20, the primary ammonia gas pipeline 5-21, the secondary ammonia gas pipeline 5-22 and the tertiary ammonia gas pipeline 5-23 of the ammonia gas/coal powder burner 5-1 on the corner, opening the primary air pipeline 5-12 and the peripheral air pipeline 5-19, and igniting by using the plasma igniter 5-14 to carry out coal powder combustion;

and when the ammonia gas blending combustion ratio is 20-60%, opening all or part of combustion improver pipelines 5-20, primary ammonia gas pipelines 5-21, secondary ammonia gas pipelines 5-22, tertiary ammonia gas pipelines 5-23 and peripheral air pipelines 5-19 of the ammonia gas/pulverized coal burner 5-1 at the corners for ammonia gas combustion, and closing the primary air pipelines 5-12.

The ammonia gas/pulverized coal burner 5-1 on the corner can not simultaneously carry out ammonia gas combustion and pulverized coal combustion. When the ammonia gas and the coal powder are combusted, the plasma igniters 5-14 are used for ignition and combustion.