A concentrated device adjustable swirl burner adapted to multi-coal combustion

Abstract

The application provides an adjustable concentrated device swirl burner suitable for multi-coal combustion, and relates to the technical field of swirl burners.The adjustable concentrated device swirl burner comprises a primary air pipe, and a concentrated device is arranged in the primary air pipe.The concentrated device comprises a fixed concentrated device, an adjustable concentrated device and a driving assembly.The fixed concentrated device is arranged in the primary air pipe, and the adjustable concentrated device is arranged in the primary air pipe.The outer side wall of the adjustable concentrated device is arranged at intervals with the inner side wall of the primary air pipe, and the side of the adjustable concentrated device close to the coal powder inlet is provided with a first flow guide inclined surface.The driving assembly is arranged in the primary air pipe and is drivingly connected with the adjustable concentrated device, and the driving assembly is used for driving the adjustable concentrated device to be close to or away from the fixed concentrated device.The adjustable concentrated device swirl burner cancels the traditional central air pipe, and the position of the concentrated device can be adjusted, so that the position of the concentrated device can be adjusted according to different coal, the coal powder concentration effect is adjusted, the coal quality adaptability is improved, the stable combustion capacity can be adjusted, and the NOx emission can be controlled.

Description

Technical Field

[0001] This invention relates to the field of swirl burner technology, and more specifically, to an adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types. Background Technology

[0002] As a vital guarantee for technological development and people's lives in today's society, the power system relies heavily on coal-fired power as the "ballast" for stable power production and supply in my country. Coal-fired power remains a crucial pillar of the power system. The development direction for coal-fired power generation is towards efficient, flexible, and low-pollution power generation technologies that achieve high efficiency, low nitrogen oxide (NOx) emissions, anti-slagging, anti-high-temperature corrosion, strong low-load stable combustion capability, and good adaptability to different coal types while burning coal.

[0003] Pulverized coal cyclone burners are widely used in power plant boilers and are core equipment in the combustion system. They mainly consist of a cyclone separator, nozzles, air ducts, fuel nozzles, shell, and connecting components. During operation, the rotating airflow forms a recirculation zone, which can entrain high-temperature flue gas from the furnace, heating the pulverized coal airflow and promoting fuel ignition and combustion. However, they generally suffer from problems such as poor adaptability to different coal types (difficult to adapt to different coal types), severe wear of the central air duct in some burners, and excessive NOx emissions.

[0004] In the design of swirl burners, the central duct primarily serves to adjust the flame center position, but this function is not particularly effective in practical applications. Pulverized coal concentrators utilize a blunt structure at the center of the primary air duct to separate the pulverized primary air flow into two streams of pulverized coal, one rich and one light, which facilitates ignition and flame propagation, enhancing combustion stability. However, with the continuous changes in coal types during power plant operation, conventional fixed pulverized coal concentrators can no longer meet combustion demands. Therefore, developing a new type of swirl pulverized coal burner to adapt to these requirements is particularly important. Summary of the Invention

[0005] The purpose of this invention is to provide an adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types. It eliminates the traditional central air duct and adopts an adjustable concentration device. The relative positions of the adjustable concentration device and the fixed concentration device can be adjusted according to different coal types, thereby adjusting the coal powder concentration effect, increasing coal quality adaptability, and achieving adjustable stable combustion capacity and controllable NOx emissions.

[0006] The technical solution adopted in this invention is as follows:

[0007] This application provides an adjustable swirl burner for a thickening device adapted to the combustion of multiple coal types. It includes a primary air duct, one end of which is a combustion end. The primary air duct is connected to a pulverized coal inlet, and a thickening device is installed inside the primary air duct. The thickening device includes:

[0008] A fixed concentrator is located inside the primary air duct, with its outer wall spaced apart from the inner wall of the primary air duct.

[0009] An adjustable concentrator is movably installed inside the primary air duct. The adjustable concentrator is coaxial with the fixed concentrator and is located on the side of the fixed concentrator away from the combustion end. The outer wall of the adjustable concentrator is spaced apart from the inner wall of the primary air duct, and the side of the adjustable concentrator near the pulverized coal inlet has a first guide slope.

[0010] The drive assembly is located in the primary air duct and is connected to the adjustable concentrator drive. The drive assembly is used to drive the adjustable concentrator closer to or further away from the fixed concentrator.

[0011] Furthermore, in some embodiments of the present invention, the adjustable concentration device has a second guide slope on the side near the fixed concentration device, and the second guide slope and the first guide slope form a first plane.

[0012] Furthermore, in some embodiments of the present invention, the fixed concentration device has a third flow guide slope on the side near the adjustable concentration device.

[0013] Furthermore, in some embodiments of the present invention, the fixed concentration device has a fourth guide slope on the side near the combustion end, and a second plane is formed between the third guide slope and the fourth guide slope.

[0014] Furthermore, in some embodiments of the present invention, the driving component includes:

[0015] A central bluff body is slidably disposed in the primary air duct along the axial direction of the primary air duct, with at least a portion of the central bluff body located inside the primary air duct, and an adjustable concentration device is fixedly sleeved on the outer wall of the central bluff body.

[0016] Furthermore, in some embodiments of the present invention, the fixed concentration device has a through hole that extends through the fixed concentration device along the axial direction of the primary air duct, a central blunt body passes through the through hole, and the outer wall of the central blunt body is spaced apart from the inner wall of the fixed concentration device.

[0017] Furthermore, in some embodiments of the present invention, the end of the central blunt body near the combustion end is a pointed tip.

[0018] Furthermore, in some embodiments of the present invention, the central blunt body slidably passes through the primary air duct, and a seal is provided between the central blunt body and the primary air duct; the seal is fixed to the primary air duct, and the central blunt body slidably passes through the seal.

[0019] Furthermore, in some embodiments of the present invention, the drive assembly further includes an actuator connected to the central bluff body, the actuator being used to drive the central bluff body to slide along the primary air duct.

[0020] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0021] This application eliminates the traditional central duct and adopts an adjustable-position concentration device. The relative positions of the adjustable and fixed concentration devices can be adjusted according to different coal types, thereby adjusting the coal powder concentration effect, increasing coal quality adaptability, and achieving adjustable stable combustion capacity and controllable NOx emissions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the internal structure of a swirl burner provided in an embodiment of the present invention;

[0024] Figure 2 A partial structural diagram of the fixed concentration device and the adjustable concentration device provided in an embodiment of the present invention after they are brought close together;

[0025] Figure 3 This is a partial structural diagram of the fixed concentration device and the adjustable concentration device provided in an embodiment of the present invention after they are moved away from each other.

[0026] icon:

[0027] 10-Primary air duct; 11-Pulverized coal inlet; 12-Seal; 13-Inner secondary air duct; 14-Inner secondary air regulating device; 15-Outer secondary air duct; 16-Outer secondary air regulating device; 17-Connecting rod;

[0028] 20 - Fixed concentration device; 21 - Through hole; 22 - Third guide slope; 23 - Fourth guide slope; 24 - Second plane;

[0029] 30 - Adjustable concentration device; 31 - First guide slope; 32 - Second guide slope; 33 - First plane;

[0030] 40 - Drive component; 41 - Central blunt body; 42 - Actuator. Detailed Implementation

[0031] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0032] Example

[0033] Please refer to Figures 1-3This embodiment provides an adjustable swirl burner for a concentrator adapted to the combustion of multiple coal types. It includes a primary air duct 10, one end of which is the combustion end. The primary air duct 10 is connected to a pulverized coal inlet 11, and a concentrator is installed inside the primary air duct 10. The primary air duct 10 in this embodiment is an existing product. The pulverized coal inlet 11 is used to transport pulverized coal into the primary air duct 10, where it is burned at the combustion end. An existing inner secondary air duct 13 can be correspondingly installed on the outside of the primary air duct 10, and the inner secondary air duct 13 is adjusted by an existing inner secondary air regulating device 14. An existing outer secondary air duct 15 can be correspondingly installed on the outside of the inner secondary air duct 13, and the outer secondary air duct 15 is adjusted by an existing outer secondary air regulating device 16. The concentrator divides the pulverized coal-containing primary airflow into two streams of pulverized coal airflow, which is beneficial for the ignition and flame propagation of the pulverized coal airflow and enhances combustion stability.

[0034] The concentration device of this application includes a fixed concentration device 20, an adjustable concentration device 30, and a drive assembly 40. The fixed concentration device 20 is located inside the primary air duct 10 and is coaxial with the primary air duct 10. The outer wall of the fixed concentration device 20 is spaced apart from the inner wall of the primary air duct 10. The outer wall of the fixed concentration device 20 and the inner wall of the primary air duct 10 are fixedly connected by a plurality of spaced connecting rods 17. The coal powder airflow can flow through the gap between the outer wall of the fixed concentration device 20 and the inner wall of the primary air duct 10.

[0035] The adjustable concentrator 30 is movably disposed inside the primary air duct 10. The adjustable concentrator 30 is coaxial with the fixed concentrator 20 and is located on the side of the fixed concentrator 20 away from the combustion end. The outer wall of the adjustable concentrator 30 is spaced apart from the inner wall of the primary air duct 10. The adjustable concentrator 30 has a first guide slope 31 on the side near the pulverized coal inlet 11. The first guide slope 31 can guide the airflow entering the primary air duct 10 and separate the pulverized coal particles in the pulverized coal airflow outward. Most of the pulverized coal is closer to the inner wall of the primary air duct 10 when it separates outward due to its large weight. Therefore, after being diverted by the first guide slope 31 of the adjustable concentrator 30, the pulverized coal concentration near the inner wall of the primary air duct 10 is greater, and the pulverized coal concentration near the outer wall of the adjustable concentrator 30 is smaller. This makes the airflow into two pulverized coal airflows of different concentrations.

[0036] The drive assembly 40 is located in the primary air duct 10 and is connected to the adjustable concentrator 30. The drive assembly 40 is used to drive the adjustable concentrator 30 closer to or further away from the fixed concentrator 20. When the adjustable concentrator 30 approaches the fixed concentrator 20, as... Figure 2 As shown, at this time, the distance between the adjustable concentration device 30 and the combustion end of the primary air duct 10 is shortened, which helps to form an external concentrated and internal light coal powder airflow at the combustion end.

[0037] When the adjustable concentration device 30 is moved away from the fixed concentration device 20, such as Figure 3 As shown, although the pulverized coal airflow will first be diverted through the adjustable concentrator 30, after diversion, due to the greater distance from the fixed concentrator 20, as the pulverized coal airflow continues to flow, most of the pulverized coal particles will collide with the inner wall of the primary air duct 10 and bounce back. Therefore, when the adjustable concentrator 30 moves away from the fixed concentrator 20, the distance between the adjustable concentrator 30 and the combustion end of the primary air duct 10 increases. Although the pulverized coal airflow is still distributed with a richer outer layer and a less rich inner layer, compared to the pulverized coal airflow after the adjustable concentrator 30 is close to the fixed concentrator 20, the pulverized coal content near the inner wall of the primary air duct 10 will decrease. Therefore, it helps to weaken the situation of a richer outer layer and a less rich inner layer of pulverized coal and strengthen the central combustion.

[0038] Therefore, in practical use:

[0039] For coal types with low volatile matter, the adjustable concentrator 30 can be moved axially outward, that is, the adjustable concentrator 30 is moved away from the fixed concentrator 20, which weakens the external concentration and internal dilutes, strengthens the central combustion, and achieves stable combustion.

[0040] For high volatile coal types, the adjustable thickener 30 can be moved axially inward, that is, the adjustable thickener 30 can be moved closer to the fixed thickener 20 to enhance the concentration of coal outside and the light concentration inside, thereby reducing NOx emissions.

[0041] When the load is high and the furnace temperature is high, the combustion reaction is fast. The adjustable concentration device 30 can be moved axially inward to reduce the air-coal mixing in the early stage of combustion, thereby obtaining a lower oxygen concentration and lower NOx generation. It can also reduce the heat load at the burner nozzle, thereby reducing burn-off and coking problems at the burner nozzle.

[0042] When the load is low and the furnace temperature is low, a more concentrated central pulverized coal is required. The adjustable concentration device 30 can be moved axially outward to enhance central combustion, which is more conducive to combustion stability and meets lower peak-shaving requirements.

[0043] Therefore, the swirl burner provided in this application eliminates the traditional central air duct and adopts an adjustable position concentration device. The relative position of the adjustable concentration device 30 and the fixed concentration device 20 can be adjusted according to different coal types, thereby adjusting the coal powder concentration effect, increasing coal quality adaptability, and achieving adjustable stable combustion capacity and controllable NOx emissions.

[0044] Furthermore, in existing technologies, a central duct is installed within the primary air duct 10. This central duct primarily alters the pulverized coal airflow dynamic field at the burner outlet by adjusting the central air volume, thereby changing the flame center. This application utilizes an adjustable concentrator 30 and a fixed concentrator 20 in conjunction to change the concentrator ratio and the central outlet velocity of the burner, thus altering the pulverized coal airflow dynamic field at the burner outlet and consequently changing the flame center. When the adjustable concentrator 30 moves outward, the pulverized coal concentration ratio decreases, the outlet velocity in the central part of the burner decreases, and the flame center moves closer to the burner, achieving better stable combustion. When the adjustable concentrator 30 moves inward, the pulverized coal concentration ratio increases, the outlet velocity in the central part of the burner increases, and the flame center moves further away from the burner, achieving better reduction of nitrogen oxides and reducing the risk of burner burnout. Therefore, through the design of this application, the function of the original central duct in adjusting the combustion flame center can be replaced by the adjustable concentrator 30, eliminating the need for the existing central duct and avoiding wear and burnout of the nozzles.

[0045] like Figures 1-3 As shown, in some embodiments, the adjustable concentrator 30 has a second guide slope 32 on the side near the fixed concentrator 20, and a first plane 33 is formed between the second guide slope 32 and the first guide slope 31. The second guide slope 32 can prevent the airflow from forming vortices at the end of the adjustable concentrator 30 near the combustion end. The formation of vortices will affect the conveying of pulverized coal and is not conducive to the combustion of the pulverized coal airflow.

[0046] like Figures 1-3 As shown, in some embodiments, the fixed concentrator 20 has a third guide slope 22 on the side near the adjustable concentrator 30. The drive assembly 40 includes a central blunt body 41, which is slidably disposed in the primary air duct 10 along the axial direction of the primary air duct 10. The central blunt body 41 is at least partially located inside the primary air duct 10, and the adjustable concentrator 30 is fixedly sleeved on the outer wall of the central blunt body 41. The fixed concentrator 20 has a through hole 21 extending through the fixed concentrator 20 along the axial direction of the primary air duct 10. The central blunt body 41 passes through the through hole 21, and the outer wall of the central blunt body 41 is spaced apart from the inner wall of the fixed concentrator 20.

[0047] By setting a central blunt body 41, the position of the adjustable concentrator 30 can be adjusted by driving the central blunt body 41 to slide along the axial direction of the primary air duct 10. Moreover, by setting a third guide slope 22, the outer wall of the central blunt body 41 is spaced apart from the inner wall of the fixed concentrator 20. Therefore, after the gas is diverted by the adjustable concentrator 30, the gas with a high coal powder content is close to the inner wall of the primary air duct 10. Therefore, after being guided by the third guide slope 22, this part of the gas can flow away through the gap between the outer wall of the fixed concentrator 20 and the inner wall of the primary air duct 10. The gas with a low coal powder content is close to the outer wall of the adjustable concentrator 30. Therefore, this part of the gas can flow away through the gap between the inner wall of the fixed concentrator 20 and the outer wall of the central blunt body 41.

[0048] Furthermore, the closer the distance between the adjustable thickener 30 and the fixed thickener 20, the higher the coal powder concentration on the outer side of the airflow after the fixed thickener 20 is diverted. This is because the closer the distance, the faster the airflow can be diverted by the third guide slope 22 of the fixed thickener 20 after being diverted by the adjustable thickener 30. Conversely, the farther the distance between the adjustable thickener 30 and the fixed thickener 20, the lower the coal powder concentration on the outer side of the airflow after being diverted by the fixed thickener 20. This is because the farther the distance, the more coal powder particles will bounce off the inner wall of the primary duct 10 after being diverted by the adjustable thickener 30. Therefore, before the airflow reaches the fixed thickener 20 and is diverted by the third guide slope 22, the coal powder content on the inner side of the airflow will increase, resulting in a weakened effect of a concentrated outer and diluted inner coal powder airflow.

[0049] like Figures 1-3 As shown, in some embodiments, the fixed concentrator 20 has a fourth guide slope 23 on the side near the combustion end, and a second plane 24 is formed between the third guide slope 22 and the fourth guide slope 23. The fourth guide slope 23 can prevent the airflow from forming vortices at the end of the fixed concentrator 20 near the combustion end. The formation of vortices will affect the conveying of pulverized coal and is not conducive to the combustion of the pulverized coal airflow.

[0050] In this embodiment, the adjustable concentration device 30 is annular with a cylindrical center and frustum shapes on both sides. The fixed concentration device 20 is also annular with a cylindrical center and frustum shapes on both sides.

[0051] like Figures 1-3 As shown, in some embodiments, the end of the central blunt body 41 near the combustion end is a pointed tip. The pointed tip can make the end of the central blunt body 41 near the combustion end a slope, preventing the airflow from forming vortices at the end of the central blunt body 41 near the combustion end. Vortices would affect the conveying of pulverized coal and would be detrimental to the combustion of the pulverized coal airflow.

[0052] like Figure 1As shown, in some embodiments, the central blunt body 41 slidably passes through the primary air duct 10, and a sealing element 12 is provided between the central blunt body 41 and the primary air duct 10; the sealing element 12 is fixed to the primary air duct 10, and the central blunt body 41 slidably passes through the sealing element 12. In this embodiment, the sealing element 12 can be a high-temperature resistant sealing ring, so that the connection between the central blunt body 41 and the primary air duct 10 can be slidably sealed by the sealing element 12 to prevent the coal powder airflow from overflowing.

[0053] like Figures 1-3 As shown, in some embodiments, the drive assembly 40 further includes an actuator 42 connected to the central blunt body 41. The actuator 42 drives the central blunt body 41 to slide along the primary air duct 10. In this embodiment, the actuator 42 can be an existing electric push rod. During use, the cylinder of the electric push rod is fixedly installed, and the telescopic end of the electric push rod is connected to the central blunt body 41. The electric push rod can be extended and shortened by electric control, which facilitates the adjustment of the position of the adjustable concentration device 30 by driving the central blunt body 41 to slide along the primary air duct 10, making operation convenient.

[0054] Furthermore, unless otherwise explicitly specified or limited, the terms "installation" and "connection" in this application embodiment should be interpreted broadly. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. The terms "upper," "lower," "left," "right," "inner," "outer," and "side," etc., are merely for reference to the direction in the accompanying drawings or the usual placement of the product during use. They are only for clearly describing this application and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limitations on this application. The terms "first," "second," etc., are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance; "multiple" refers to at least two. In this application embodiment, the limitations on relative positional relationships such as parallel, perpendicular, and aligned are all relative to the current technological level and are not absolutely strict limitations. Slight deviations are allowed; approximations of parallel, perpendicular, and aligned are all acceptable. For example, "A and B are parallel" means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 degrees and 10 degrees.

[0055] The above are only some embodiments and implementation methods of this application. The protection scope of this application is not limited thereto. In the absence of conflict, the embodiments and features in the embodiments of this application can be combined with each other. Any combination of features in different embodiments is also within the protection scope of this application. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the protection scope of this application.

Claims

1. An adjustable swirl burner for a thickening device adapted to the combustion of multiple coal types, comprising a primary air duct (10), one end of which is a combustion end, the primary air duct (10) being connected to a pulverized coal inlet (11), and a thickening device being provided inside the primary air duct (10); characterized in that, The concentration device includes: A fixed concentration device (20) is provided inside the primary air duct (10), and the outer wall of the fixed concentration device (20) is spaced apart from the inner wall of the primary air duct (10). An adjustable concentrator (30) is movably disposed inside the primary air duct (10). The adjustable concentrator (30) is coaxial with the fixed concentrator (20). The adjustable concentrator (30) is located on the side of the fixed concentrator (20) away from the combustion end. The outer wall of the adjustable concentrator (30) is spaced apart from the inner wall of the primary air duct (10). The adjustable concentrator (30) has a first guide slope (31) on the side near the pulverized coal inlet (11). A drive assembly (40) is provided in the primary air duct (10) and is driven to the adjustable concentrator (30). The drive assembly (40) is used to drive the adjustable concentrator (30) to move closer to or further away from the fixed concentrator (20). The adjustable concentrator (30) has a second guide slope (32) on the side near the fixed concentrator (20), and the second guide slope (32) and the first guide slope (31) form a first plane (33); the fixed concentrator (20) has a third guide slope (22) on the side near the adjustable concentrator (30); the fixed concentrator (20) has a fourth guide slope (23) on the side near the combustion end, and the third guide slope (22) and the fourth guide slope (23) form a second plane (24).

2. The adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types according to claim 1, characterized in that, The driving component (40) includes: A central blunt body (41) is slidably disposed in the primary air duct (10) along the axial direction of the primary air duct (10). The central blunt body (41) is at least partially located inside the primary air duct (10). The adjustable concentration device (30) is fixedly sleeved on the outer wall of the central blunt body (41).

3. The adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types according to claim 2, characterized in that, The fixed concentration device (20) has a through hole (21) that extends through the primary air duct (10) along the axial direction of the fixed concentration device (20). The central blunt body (41) passes through the through hole (21), and the outer wall of the central blunt body (41) is spaced apart from the inner wall of the fixed concentration device (20).

4. The adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types according to claim 2, characterized in that, The central blunt body (41) has a pointed end near the combustion end.

5. The adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types according to claim 2, characterized in that, The central blunt body (41) can slide through the primary air duct (10), and a sealing element (12) is provided between the central blunt body (41) and the primary air duct (10); the sealing element (12) is fixed to the primary air duct (10), and the central blunt body (41) can slide through the sealing element (12).

6. The adjustable swirl burner for a concentration device adapted to the combustion of multiple coal types according to claim 2, characterized in that, The drive assembly (40) further includes an actuator (42) connected to the central blunt body (41) and the actuator (42) is used to drive the central blunt body (41) to slide along the primary air duct (10).

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