Swirl burner, boiler and combustion method

Abstract

The present invention discloses a swirl burner, a boiler and a combustion method. The swirl burner includes: a primary air duct for outputting primary air; an inner secondary air duct sleeved outside the primary air duct for outputting inner secondary air; a partition pipe sleeved between the inner secondary air duct and the primary air duct for separating the passing inner secondary air into inner secondary air inner side air flowing through the flow channel between the partition pipe and the primary air duct and inner secondary air outer side air flowing through the flow channel between the partition pipe and the inner secondary air duct; an adjusting device including a driving part and a plurality of blades with adjustable inclination angles arranged between the partition pipe and the primary air duct, the plurality of blades being circumferentially distributed along the primary air duct, and the driving part being used for driving the plurality of blades to rotate around their respective rotation axes to adjust the inclination angles.

Description

Technical Field

[0001] The present invention relates to the field of pulverized coal combustion, and particularly to a swirl burner, a boiler, and a combustion method. Background Art

[0002] In the power generation share of China's power industry, most of it is thermal power generation. In thermal power generation, pulverized coal is often used to burn in the furnace of the boiler, and a swirl burner is often used during boiler combustion. The swirl burner is composed of various air ducts with nozzles, mainly including a primary air duct for transporting primary air (i.e., an air flow carrying pulverized coal, also known as a pulverized coal air flow), a secondary air duct for transporting secondary air, an ignition device for igniting the primary air, etc. When the primary air, secondary air, etc. pass through the swirler in the burner, they rotate and form a rotating jet when ejected from the nozzle. The rotating jet can form a high-temperature flue gas recirculation zone, and the size of the high-temperature flue gas recirculation zone directly affects the ignition and combustion of pulverized coal.

[0003] In order to pursue economic benefits, existing thermal power plants use a wide variety of coal types with uneven quality. For example, there is coal with high volatile content and coal with low volatile content. The existing swirl burners have limited adjustment degrees for the combustion processes of different types of coal and cannot adjust a suitable combustion process when burning different coal types. Summary of the Invention

[0004] The purpose of the present invention is to provide a swirl burner that can adapt to the combustion of primary air of various coals and adjust a suitable combustion process. The present invention also provides a boiler and a combustion method using the swirl burner.

[0005] The first aspect of the present invention discloses a swirl burner, including:

[0006] A primary air duct for outputting primary air;

[0007] An inner secondary air duct sleeved outside the primary air duct for outputting inner secondary air;

[0008] A partition pipe sleeved between the inner secondary air duct and the primary air duct for separating the passing inner secondary air into inner secondary air inner side wind flowing through the flow channel between the partition pipe and the primary air duct and inner secondary air outer side wind flowing through the flow channel between the partition pipe and the inner secondary air duct;

[0009] An adjusting device, including a driving part and a plurality of blades with adjustable inclination angles arranged between the partition pipe and the primary air duct. The plurality of blades are circumferentially distributed along the primary air duct, and the driving part is used to drive the plurality of blades to rotate around their respective rotation axes to adjust the inclination angles.

[0010] In some embodiments, the adjusting device further includes a plurality of rotating shafts fixedly connected to the plurality of vanes one by one. The driving part includes an annular body sleeved outside the primary air duct and a plurality of link mechanisms corresponding to the plurality of vanes one by one. One end of the link mechanism is connected to the annular body, and the other end of the link mechanism is fixedly connected to the rotating shaft of the corresponding vane. The driving part is configured to drive the rotating shafts of the plurality of link mechanisms to rotate the corresponding vanes by moving the annular body, so as to adjust the inclination angle of the corresponding vanes.

[0011] In some embodiments, the link mechanism includes a first rod and a second rod. The first end of the first rod is hinged to the annular body, the second end of the first rod is hinged to the first end of the second rod, and the second end of the second rod is fixedly connected to the rotating shaft of the vane corresponding to the link mechanism.

[0012] In some embodiments, the rotating shafts of the plurality of vanes are hinged to the partition pipe, and the annular body is sleeved outside the partition pipe.

[0013] In some embodiments, the plurality of vanes are at the same position in the axial direction of the primary air duct. The working surface of the vane for the inner secondary air flowing inside is a plane. The plurality of vanes have a flush state. When the driving part drives the plurality of vanes to rotate to the flush state, the plurality of vanes are connected to each other to form an annular plate, and the working surfaces of the plurality of vanes are flush with each other to form an annular surface.

[0014] In some embodiments, it further includes:

[0015] An outer secondary air duct, sleeved outside the inner secondary air duct, for outputting outer secondary air. The partition pipe is configured to lead the outer secondary air on the inner secondary air side to be mixed with the outer secondary air.

[0016] In some embodiments, the partition pipe includes a straight pipe section sleeved outside the primary air duct and a gradually expanding pipe section located downstream of the straight pipe section along the flow direction of the outer secondary air on the inner secondary air side.

[0017] In some embodiments, the swirl burner includes a concentration-dilution separation device disposed in the primary air duct. The concentration-dilution separation device is used to separate the primary air into a concentrated primary air located radially outside and a diluted primary air located radially inside in the primary air duct.

[0018] The second aspect of the present invention discloses a boiler including the swirl burner described above.

[0019] The third aspect of the present invention discloses a combustion method using the swirl burner described above, including:

[0020] Introduce primary air into the primary air duct;

[0021] Introduce inner secondary air into the inner secondary air duct, and use the partition pipe to divide the inner secondary air into inner secondary air inner side air and inner secondary air outer side air;

[0022] When the pulverized coal in the primary air is changed to pulverized coal with low volatile content, use the driving part to drive the plurality of blades to adjust the inclination angle to increase the swirl intensity of the inner secondary air inner side air and reduce the flow rate ratio of the inner secondary air inner side air in the inner secondary air;

[0023] When the pulverized coal in the primary air is changed to pulverized coal with high volatile content, use the driving part to drive the plurality of blades to adjust the inclination angle to reduce the swirl intensity of the inner secondary air inner side air and increase the flow rate ratio of the inner secondary air inner side air in the inner secondary air.

[0024] In some embodiments, the swirl burner further includes an outer secondary air duct for outputting outer secondary air. The outer secondary air duct is sleeved outside the inner secondary air duct. The partition pipe is configured to lead the outer side air of the inner secondary air to be mixed with the outer secondary air. The combustion method further includes introducing outer secondary air into the outer secondary air duct.

[0025] Based on the swirl burner provided by the present invention, by arranging a partition pipe and an adjusting device in the inner secondary air duct, when burning the primary air of pulverized coal with lower volatile content, the driving part can be used to drive the plurality of blades to rotate around their respective rotation axes, adjust and increase the swirl intensity of the inner secondary air inner side air and at the same time reduce the flow rate ratio of the inner secondary air inner side air, so as to increase the size of the high-temperature flue gas recirculation zone between the inner secondary air inner side air and the primary air, advance the ignition point position of the primary air, strengthen the combustion of the pulverized coal air flow, make the volatile matter of the pulverized coal air flow precipitate earlier, postpone the mixing point of the secondary air and the primary air, and reduce the generation amount of NOx (nitrogen oxides). When burning the primary air of coal with higher volatile content, the driving part can be used to drive the plurality of blades to rotate around their respective rotation axes, adjust and reduce the swirl intensity of the inner secondary air inner side air and increase the flow rate ratio of the inner secondary air inner side air, make the position of the high-temperature flue gas recirculation zone away from the burner nozzle, postpone the ignition point of the primary air, reduce the initial ignition intensity, reduce problems such as burning and slagging of the burner nozzle, and at the same time increase the air volume of the inner secondary air inner side air, make the mixing point of the secondary air and the primary air advance, and improve the combustion efficiency of the coal with high volatile content.

[0026] The boiler and combustion method applying the swirl burner of the present invention also have corresponding beneficial effects.

[0027] Through the following detailed description of the exemplary embodiments of the present invention with reference to the drawings, other features and advantages of the present invention will become clear. Description of the Drawings

[0028] The accompanying drawings described herein are used to provide a further understanding of the present invention and form a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0029] Figure 1 is a schematic structural diagram of a swirl burner according to an embodiment of the present invention;

[0030] Figure 2 is Figure 1 a schematic structural diagram of the adjusting device of the shown swirl burner in one state;

[0031] Figure 3 is Figure 2 a schematic structural diagram of the adjusting device shown in another state. Detailed Embodiments

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0033] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that for the sake of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0034] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. can be used here to describe the spatial positional relationship of a device or feature shown in the figure with other devices or features. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation described in the figure for the device. For example, if the device in the attached drawing is inverted, the device described as "above or over other devices or structures" will then be positioned "below or under other devices or structures". Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0035] As Figures 1 to 3 shown, the swirl burner disclosed in this embodiment includes a primary air duct 1, an inner secondary air duct 21, a partition pipe 3, and an adjusting device 4.

[0036] The primary air duct 1 is used to output primary air. During boiler combustion, coal is ground into pulverized coal by a coal mill, and then forms primary air through mixing with air and is sent into the primary air duct 1. The primary air duct 1 outputs the primary air through a nozzle into the furnace of the boiler for combustion.

[0037] The inner secondary air duct 21 is sleeved outside the primary air duct 1 and is used to output inner secondary air; the inner secondary air duct 21 is used to output inner secondary air into the furnace. In the embodiment as Figure 1 shown, the secondary air duct includes an inner secondary air duct 21 and an outer secondary air duct 22, and the secondary air includes the inner secondary air output by the inner secondary air duct 21 and the outer secondary air output by the outer secondary air duct 22. In some embodiments not shown in the drawings, when the secondary air duct only includes the inner secondary air duct 21, the inner secondary air output by the inner secondary air duct 21 is the secondary air.

[0038] The partition pipe 3 is sleeved between the inner secondary air duct 21 and the primary air duct 1, and the partition pipe 3 is used to divide the passing inner secondary air into inner secondary air inner side air flowing through the flow channel between the partition pipe 3 and the primary air duct 1 and inner secondary air outer side air flowing through the flow channel between the partition pipe 3 and the inner secondary air duct 21.

[0039] As Figures 1 to 3 shown, the adjusting device 4 includes a driving part and a plurality of blades 41 with adjustable inclination angles arranged between the partition pipe 3 and the primary air duct 1. The plurality of blades 41 are circumferentially distributed along the primary air duct 1, and the driving part is used to drive the plurality of blades 41 to rotate around their respective rotation axes to adjust the inclination angle.

[0040] Due to the swirling burner of this embodiment, a partition pipe 3 is arranged in the inner secondary air duct 21 to divide the inner secondary air into the inner secondary air inner side air and the inner secondary air outer side air. Thus, the greater the flow resistance of the inner secondary air inner side air between the partition pipe 3 and the primary air duct 1, the smaller the flow rate ratio of the inner secondary air inner side air in the inner secondary air; the smaller the flow resistance of the inner secondary air inner side air between the partition pipe 3 and the primary air duct 1, the greater the flow rate ratio of the inner secondary air inner side air in the inner secondary air.

[0041] The driving part can adjust the inclination angles of multiple vanes 41. For example, Figure 2 as shown, when the inclination degree of the multiple vanes 41 relative to the cross-section of the partition pipe 3 is smaller, the flow-through area between the multiple vanes 41 is reduced, increasing the flow resistance of the inner secondary air inner side air, so that the swirl intensity of the inner secondary air inner side air can be increased and at the same time the flow rate ratio of the inner secondary air inner side air in the inner secondary air can be reduced. The driving part can also adjust the inclination angles of the multiple vanes 41. For example, as Figure 3 shown, when the inclination degree of the multiple vanes 41 relative to the cross-section of the partition pipe 3 is larger, the flow-through area between the multiple vanes 41 is increased, reducing the flow resistance of the inner secondary air inner side air, so as to reduce the swirl intensity of the inner secondary air inner side air and at the same time increase the flow rate ratio of the inner secondary air inner side air in the inner secondary air. That is, the adjustment of the inclination angles of the multiple vanes 41 by the adjustment device 4 will simultaneously produce two effects on the inner secondary air inner side air: adjusting the swirl intensity and changing the flow rate ratio.

[0042] The swirling burner of this embodiment divides the inner secondary air into the inner secondary air inner side air and the inner secondary air outer side air by arranging the partition pipe 3 and the adjustment device 4 in the inner secondary air duct 21, and the adjustment device can simultaneously adjust the swirl intensity of the inner secondary air inner side air and the flow rate ratio of the inner secondary air inner side air in the inner secondary air. When burning pulverized coal airflow for, for example, low-volatile coal, the driving part drives the multiple vanes to rotate around their respective rotation axes, increasing the swirl intensity of the inner secondary air inner side air and at the same time reducing the flow rate of the inner secondary air inner side air. The increase in the swirl intensity of the inner secondary air inner side air will increase the size of the high-temperature flue gas recirculation zone between the inner secondary air inner side air and the primary air, and reducing the flow rate of the inner secondary air inner side air can also increase the length of the high-temperature flue gas recirculation zone between the inner secondary air inner side air and the primary air. Thus, the adjustment device can have an obvious adjustment effect on the size of the high-temperature flue gas recirculation zone. For the combustion of low-volatile coal, the high-temperature flue gas recirculation zone is closer to the burner nozzle, which can advance the ignition point of the primary air. The increase in the swirl intensity will increase the turbulence degree at the outlet of the burner nozzle, strengthening the combustion of the pulverized coal airflow. The increase in the high-temperature flue gas recirculation zone will cause the volatile matter of the pulverized coal airflow to be released earlier, delaying the mixing point of the secondary air and the primary air and reducing the generation amount of NOx (nitrogen oxides).

[0043] When burning, for example, high-volatile coal or low-ash-melting-point coal, the driving part can drive multiple vanes to rotate around their respective rotation axes, reduce the swirl intensity of the inner secondary air on the inner side and at the same time increase the flow rate ratio of the inner secondary air on the inner side, move the position of the high-temperature flue gas recirculation zone away from the burner nozzle, delay the ignition point of the primary air, reduce the initial ignition intensity, and reduce problems such as burner nozzle burnout and slagging. At the same time, increasing the air volume of the inner secondary air on the inner side can advance the mixing point of the secondary air and the primary air and improve the combustion efficiency of high-volatile coal.

[0044] The swirl burner of this embodiment has a strong adjustment function, good adjustment effect, and wide adjustment range, and can adapt to the combustion of various coals.

[0045] In some embodiments, such as Figure 2 and Figure 3 shown, the adjusting device includes a plurality of rotating shafts 412 fixedly connected to the plurality of vanes 41 one by one. The driving part includes an annular body 42 sleeved outside the primary air duct 1 and a plurality of link mechanisms 43 corresponding to the plurality of vanes 41 one by one. One end of the link mechanism 43 is connected to the annular body 42, and the other end of the link mechanism 43 is fixedly connected to the rotating shaft 412 of the corresponding vane 41. The driving part is configured to drive the rotating shafts 412 of the plurality of vanes 41 to rotate by moving the annular body 42 to adjust the inclination angle of the corresponding vane 41.

[0046] In this embodiment, by driving the annular body 42 to move along the axial direction of the swirl burner, the rotating shafts 412 of the respective vanes 41 can be rotated through the link mechanism, thereby simultaneously adjusting the inclination angles of the respective vanes 41. The adjustment method is simple, and the setting of the annular body 42 is also beneficial to reducing the interference with the flow of the inner secondary air in the inner secondary air duct 21.

[0047] The rotating shafts 412 of the respective vanes 41 can be hinged to the partition pipe 3, and the axial position of the rotating shaft 412 relative to the partition pipe 3 is fixed. At this time, the annular body 42 can be sleeved inside or outside the partition pipe 3, and the inclination angles of the respective vanes 41 are changed by the axial movement of the annular body 42 relative to the partition pipe 3. As Figure 2 shown is the state when the inclination degree of the respective vanes 41 relative to the partition pipe 3 is relatively small, Figure 3 is the state after the annular body 42 moves to increase the inclination degree of the respective vanes 41 relative to the partition pipe 3. In the embodiment shown in Figure 1 the annular body 42 is sleeved outside the partition pipe 3, the rotating shaft 412 extends out of the partition pipe 3, and the link mechanism is fixedly connected to the top end of the rotating shaft 412. This setting can reduce the influence of the annular body and the link mechanism on the flow channel of the inner secondary air on the inner side. In some embodiments not shown in the drawings, the rotating shaft 412 can also be hinged to the primary air duct 1.

[0048] In some embodiments, the link mechanism 43 includes a first rod 431 and a second rod 432. The first end of the first rod 431 is hinged to the annular body 42, the second end of the first rod 431 is hinged to the first end of the second rod 432, and the second end of the second rod 432 is fixedly connected to the rotating shaft 412 of the corresponding blade 41 of the link mechanism 43.

[0049] In some embodiments, as Figures 1 to 3 shown, the positions of the plurality of blades 41 in the axial direction of the primary air duct 1 are the same. As Figure 2 and Figure 3 shown, the working surface of the blade 41 for the inner secondary air flowing inside is a plane. The plurality of blades 41 are in a flush state. When the driving part drives the plurality of blades 41 to rotate to the flush state, the plurality of blades 41 are connected to each other to form an annular plate, and the working surfaces of the plurality of blades 41 are flush with each other to form an annular surface. The working surface of the blade 41 refers to the surface impacted by the inner secondary air on the blade 41. In the embodiment as Figure 2 shown, when the inner secondary air flows through the adjusting device from the annular body 42 to the blade 41, the working surface of the blade 41, that is, the windward surface 413 of the blade 41, which is also the suction surface of the blade 41, and the other surface of the blade 41, that is, the leeward surface 411, which is also the pressure surface 411. Since the working surface is a plane, the blade 41 of this embodiment is easier to process and manufacture. Since the plurality of blades 41 are connected to each other to form an annular plate, the working surfaces of the plurality of blades 41 are flush and connected to form an annular surface. The plurality of blades 41 of this embodiment can be integrally processed from a whole plate and then separated into a plurality of blades 41, which is easier to process and manufacture. In addition, when the working surface of each blade 41 is parallel to the axis direction, the working surface can minimize the interference with the axial flow of the inner secondary air.

[0050] In some embodiments, as Figure 1 shown, the swirl burner further includes an outer secondary air duct 22.

[0051] The outer secondary air duct 22 is sleeved outside the inner secondary air duct 21 and is used to output the outer secondary air. The partition pipe 3 is configured to lead out the outer secondary air outside the inner secondary air to be mixed with the outer secondary air. The outer secondary air duct 22 is provided to divide the secondary air into the inner secondary air and the outer secondary air. The outer secondary air is used for the later burnout of the primary air. Leading out the outer secondary air outside the inner secondary air to be mixed with the outer secondary air, when the adjusting device increases the swirl intensity of the inner secondary air and reduces the flow rate ratio of the inner secondary air, due to the mixing of the outer secondary air outside the inner secondary air, the flow rate of the outer secondary air will increase. When the swirl burner is applied to furnace combustion, the outlet air flow of the swirl burner will also penetrate deeper into the furnace, so as to be able to entrain higher temperature flue gas and promote the burnout of the primary air in the later stage.

[0052] In some embodiments, the swirl burner includes a concentration-dilution separation device 7 disposed in the primary air duct. The concentration-dilution separation device is used to separate the primary air into concentrated primary air located radially outside and diluted primary air located radially inside in the primary air duct 1. As Figure 1 shown, the concentration-dilution separation device is a cone body located in the middle of the primary air duct 1. The diameter of the cone body first increases and then decreases along the flow direction of the primary air. When the primary air impacts the surface of the cone body, the pulverized coal begins to accumulate towards the wall side of the primary air duct 1. When flowing to the diameter reduction section of the cone body, due to inertia, the diluted primary air will flow along the surface of the cone body towards the middle of the primary air duct 1, and the concentrated primary air will remain on the radially outer side in the primary air duct 1, so that the primary air is separated into concentrated and diluted air.

[0053] In some embodiments, the swirl burner further includes a first swirler 211 and a second swirler 221. The inner secondary air fed into the inner secondary air duct 21 first passes through the swirl of the first swirler 211 and then enters the inner secondary air duct. The outer secondary air fed into the outer secondary air duct 22 first passes through the swirl of the second swirler 221 and then enters the outer secondary air duct 22.

[0054] In some embodiments, the swirl burner further includes a plurality of flame stabilizer teeth 5 located at the outlet of the primary air duct 1. The plurality of flame stabilizer teeth 5 are evenly arranged along the circumferential direction of the primary air duct 1.

[0055] In some embodiments, the partition pipe 3 includes a straight pipe section 31 sleeved outside the primary air duct 1 and a gradually expanding pipe section 32 located downstream of the straight pipe section along the flow direction of the outer air of the inner secondary air. The length L of the straight pipe section 1 is 100 - 1000 mm. The angle of the gradually expanding pipe section relative to the axis of the partition pipe 3 is 10 - 55 degrees.

[0056] In some embodiments, the swirl burner further includes an ignition device for initially igniting the primary air. The ignition device includes a central air duct 61 located at the center and an oil gun 62 located in the central air duct 61. The oil gun 62 is supplied with oil, and the central air duct 61 is supplied with central air to provide oxygen for the ignition of the oil. The oil gun 62 ignites the oil to initially ignite the primary air.

[0057] In some embodiments, a boiler is also disclosed, including the above-mentioned swirl burner.

[0058] In some embodiments, a combustion method using the above-mentioned swirl burner is also disclosed, including:

[0059] Feeding primary air into the primary air duct 1;

[0060] Feeding inner secondary air into the inner secondary air duct 21, and using the partition pipe 3 to divide the inner secondary air into inner secondary air inner side air and inner secondary air outer side air;

[0061] When the pulverized coal of the primary air is changed to pulverized coal with a lower volatile content, the driving part is used to drive a plurality of blades 41 to adjust the inclination angle so as to increase the swirl intensity of the inner secondary air on the inner side and reduce the flow rate ratio of the inner secondary air on the inner side;

[0062] When the pulverized coal of the primary air is changed to pulverized coal with a higher volatile content, the driving part is used to drive a plurality of blades 41 to adjust the inclination angle so as to decrease the swirl intensity of the inner secondary air on the inner side and increase the flow rate ratio of the inner secondary air on the inner side.

[0063] In some embodiments, the swirl burner further includes an outer secondary air duct 22 for outputting outer secondary air. The outer secondary air duct 22 is sleeved outside the inner secondary air duct 21. The combustion method further includes using a partition pipe 3 to lead out the outer secondary air on the inner side of the inner secondary air to be mixed with the outer secondary air.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that it is still possible to modify the specific implementation manners of the present invention or make equivalent replacements for some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A tangential combustion burner, characterized in that, Comprising: A primary air duct (1) for outputting primary air; An inner secondary air duct (21) sleeved outside the primary air duct (1) for outputting inner secondary air; A partition duct (3) sleeved between the inner secondary air duct (21) and the primary air duct (1) for separating the passing inner secondary air into inner secondary air inner side air flowing through the flow passage between the partition duct (3) and the primary air duct (1) and inner secondary air outer side air flowing through the flow passage between the partition duct (3) and the inner secondary air duct (21); An adjusting device (4) comprising a driving part and a plurality of vanes (41) with adjustable inclination angles arranged between the partition duct (3) and the primary air duct (1), the plurality of vanes (41) being circumferentially distributed along the primary air duct (1), the driving part being configured to drive the plurality of vanes (41) to rotate around their respective rotation axes to adjust the inclination angles, the adjusting device further comprising a plurality of rotating shafts (412) fixedly connected to the plurality of vanes (41) one by one, the driving part comprising an annular body (42) sleeved outside the primary air duct (1) and a plurality of link mechanisms (43) corresponding to the plurality of vanes (41) one by one, one end of the link mechanism (43) being connected to the annular body (42), and the other end of the link mechanism (43) being fixedly connected to the rotating shaft (412) connected to the corresponding vane (41), the driving part being configured to drive the rotating shafts (412) connected to the plurality of link mechanisms (43) to rotate the corresponding vanes (41) through the movement of the annular body (42) so as to adjust the inclination angles of the corresponding vanes (41).

2. The swirl burner according to claim 1, characterized in that, The link mechanism (43) comprises a first rod (431) and a second rod (432), a first end of the first rod (431) being hinged to the annular body (42), a second end of the first rod (431) being hinged to a first end of the second rod (432), and a second end of the second rod (432) being fixedly connected to the rotating shaft (412) connected to the vane (41) corresponding to the link mechanism (43).

3. The swirl burner according to claim 2, characterized in that, The rotating shaft (412) is hinged to the partition duct (3), and the annular body (42) is sleeved outside the partition duct (3).

4. The swirl burner according to claim 2, characterized in that, The plurality of vanes (41) are at the same position in the axial direction of the primary air duct (1), the working surface of the vane (41) for the inner secondary air inner side air to flow through is a plane, the plurality of vanes (41) have a flush state, and when the driving part drives the plurality of vanes (41) to rotate to the flush state, the plurality of vanes (41) are connected to each other to form an annular plate, and the working surfaces of the plurality of vanes (41) are flush with each other to form an annular surface.

5. The swirl burner according to claim 1, characterized in that, Further comprising: An outer secondary air duct (22) sleeved outside the inner secondary air duct (21) for outputting outer secondary air, and the partition duct (3) is configured to lead out the inner secondary air outer side air to be mixed with the outer secondary air.

6. The swirl burner according to claim 5, characterized in that, The partition duct (3) comprises a straight pipe section (31) sleeved outside the primary air duct (1) and a gradually expanding pipe section (32) located downstream of the straight pipe section (31) along the flowing direction of the inner secondary air outer side air.

7. The swirl burner according to any one of claims 1 to 6, characterized in that, The swirl burner includes a concentration-dilution separation device (7) disposed in the primary air duct (1). The concentration-dilution separation device (7) is used to separate the primary air into concentrated primary air located on the outer side in the radial direction and diluted primary air located on the inner side in the radial direction in the primary air duct (1).

8. A boiler, characterized in that, It includes the swirl burner according to any one of claims 1 to 6.

9. A combustion method using a swirl burner as described in any one of claims 1 to 6, characterized in that, It includes: Introduce primary air into the primary air duct (1); Introduce inner secondary air into the inner secondary air duct (21), and use the partition pipe (3) to divide the inner secondary air into inner secondary air inner side air and inner secondary air outer side air; When the pulverized coal in the primary air is changed to pulverized coal with low volatile content, use the driving part to drive the plurality of blades (41) to adjust the inclination angle to increase the swirl intensity of the inner secondary air inner side air and reduce the flow rate ratio of the inner secondary air inner side air in the inner secondary air; When the pulverized coal in the primary air is changed to pulverized coal with high volatile content, use the driving part to drive the plurality of blades to adjust the inclination angle to reduce the swirl intensity of the inner secondary air inner side air and increase the flow rate ratio of the inner secondary air inner side air in the inner secondary air; 10. The combustion method of the swirl burner according to claim 9, characterized in that, The swirl burner further includes an outer secondary air duct (22) for outputting outer secondary air. The outer secondary air duct (22) is sleeved outside the inner secondary air duct (21). The partition pipe (3) is configured to lead the inner secondary air outer side air out to be mixed with the outer secondary air. The combustion method further includes introducing outer secondary air into the outer secondary air duct (22).

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