Low-nitrogen combustor with plasma staged combustion reinforcement

Abstract

The application discloses a low-nitrogen combustor for plasma staged combustion and relates to the technical field of combustors.The combustor comprises a combustor shell, a primary combustion cylinder, a secondary combustion cylinder and a plasma generator.The combustor shell is externally sleeved with a secondary air box.The primary combustion cylinder and the secondary combustion cylinder are respectively provided with a first impingement type thick-thin block and a second impingement type thick-thin block.The combustor shell is provided with a separation assembly.The combustor shell is provided with an adjusting assembly.The primary combustion cylinder and the secondary air box are provided with a secondary sweeping assembly.The separation assembly comprises a first separation plate and a second separation plate.The first separation plate comprises a straight line part and an arc part.The tail end of the first separation plate is hingedly connected with the second separation plate.The first separation plate and the second separation plate are fixedly arranged in the combustor shell through the adjusting assembly.The first separation plate is provided with a through hole.The position of the separation assembly can be adjusted, the ignition effect of the pulverized coal is improved, and the coking in the primary combustion cylinder can be effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of burner technology, and in particular to a low-NOx burner with plasma staged enhanced combustion. Background Technology

[0002] Plasma combustion technology refers to a combustion technology that uses direct current air plasma as an ignition source to achieve cold start-up of boilers without the need for any oil. Plasma has the property of promoting combustion. The plasma combustion system mainly includes a combustion system, an air-coal system, a plasma generator, an electrical system, a plasma air system, and a plasma cooling water system.

[0003] Chinese utility model patent CN210688203U discloses a radio frequency plasma pulverized coal ignition burner, including a burner body. The burner body includes a curved section, a burner elbow, and a straight pipe section connected in sequence. A plasma mounting tube is provided inside the burner elbow, and a primary cylinder is provided inside the straight pipe section. The primary cylinder is connected to the plasma mounting tube. Several radio frequency plasma generators are axially and evenly installed inside the plasma mounting tube, and both the primary cylinder and the radio frequency plasma generators are coaxially arranged with the burner elbow. A cooling water protection pipe and a cable protection pipe are provided between the burner elbow and the plasma mounting tube.

[0004] The above-mentioned patent has the following shortcomings in use: 1. Although a pulverized coal baffle is provided at the air inlet to adjust the pulverized coal accumulation position, it cannot be adjusted and its effect is not good under different conditions. For example, when the primary air velocity is high or the pulverized coal particles are large, the pulverized coal will be closer to the pulverized coal baffle under the centrifugal force at the bend. In this case, the pulverized coal baffle should be set close to the axis of the combustion chamber. When the primary air box is small or the pulverized coal particles are light, the pulverized coal will be slightly farther away from the pulverized coal baffle at the accumulation position. In this case, the pulverized coal baffle should be finely adjusted upwards towards the axis of the combustion chamber. 2. It is prone to coking. When the primary air is blown out from the end of the internal combustion chamber, due to the increased flow radius, it is easy to form a vortex at the end of the combustion chamber, which in turn rolls up the molten pulverized coal and debris to the inner wall of the combustion chamber, and then cokes on the inner wall. Summary of the Invention

[0005] The purpose of this invention is to provide a low-NOx burner with plasma staged enhanced combustion to solve the technical problems of the inability to adjust the air-coal baffle and the easy coking in the combustion chamber in the prior art.

[0006] This invention provides a low-NOx burner for plasma-enhanced staged combustion, comprising a burner shell, a primary combustion chamber, a secondary combustion chamber, and a plasma generator. A secondary air box is fitted around the burner shell. A first impingement-type concentration block and a second impingement-type concentration block are respectively installed inside the primary and secondary combustion chambers. A separation component for separating pulverized coal concentration is provided inside the burner shell. An adjustment component for controlling the separation component is also provided on the burner shell. A secondary purging component is provided between the primary combustion chamber and the secondary air box. The separation component includes a first separation plate and a second separation plate. The first separation plate includes a straight portion and an arc-shaped portion. The straight portion is vertically positioned within the vertical portion of the burner shell, and the arc of the arc-shaped portion is the same as the arc at the corner of the burner shell. The second separation plate is horizontally positioned within the horizontal portion of the burner shell. The end of the first separation plate is hinged to the second separation plate, and both the first and second separation plates are fixedly positioned inside the burner shell by the adjustment component. The first separation plate has a through hole for the center of the plasma generator to pass through.

[0007] Furthermore, the adjustment assembly includes a limiting rod, a main adjusting rod, and a secondary adjusting rod. The lower end of the limiting rod is fixedly connected to the first partition plate, and the other end of the limiting rod passes through the burner housing and is slidably connected to it. An adjusting block is sleeved on the end of the limiting rod located outside the burner housing. The lower end of the main adjusting rod is rotatably connected to the burner housing. The upper part of the main adjusting rod is provided with a first thread, and the upper part of the main adjusting rod is threadedly engaged with the adjusting block through the first thread. The secondary adjusting rod includes a lower connecting part and an upper threaded part. The lower end of the connecting part is hinged to the second partition plate, and the upper end of the connecting part passes through the burner housing and is slidably engaged with it. The threaded part is threadedly engaged with the adjusting block.

[0008] Furthermore, the plasma generator has a ring in the middle, the ring is located at the through hole, and baffles are provided at both the upper and lower ends of the ring.

[0009] Furthermore, one end of each baffle is rotatably connected to a ring via a torsion spring.

[0010] Furthermore, one end of each of the baffles is fixedly connected to the ring sleeve via a spring.

[0011] Furthermore, the secondary purging assembly includes a connecting cavity disposed inside the first impact-type concentrate block, and the first impact-type concentrate block has a plurality of circumferentially distributed blow heads on the side facing the end of the first combustion cylinder, and a connecting pipe is provided between the connecting cavity and the secondary air box.

[0012] Furthermore, the blowing direction of the blower head is parallel to the axis of the first combustion cylinder.

[0013] Furthermore, the blower head is a unidirectional blower.

[0014] Furthermore, a control valve is provided at one end of the connecting pipe located inside the secondary air box.

[0015] Furthermore, both the first and second partition plates have arc-shaped cross-sections.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] (1) The present invention can adjust the position of the first partition plate and the second partition plate by adjusting the component, so that the coal powder in the middle always enters the interior along the axis of the first stage combustion tube, and the coal powder is more fully ignited and the effect is better. In addition, when cold air is blown after the work is completed, the angle of the second partition plate relative to the first partition plate can also be adjusted by adjusting the component to guide the airflow to the side wall of the first stage combustion tube and improve the blowing effect.

[0018] (2) By rotating the secondary adjustment rod connected to the second partition plate, the angle between the second partition plate and the first partition plate can be changed, and after the work is completed, the purging air is guided to purge the inner wall of the first-stage combustion tube.

[0019] (3) During the ignition process, when air is supplied to the secondary air box, air is supplied to the primary combustion chamber through the connecting pipe. The blowing can alleviate the eddy currents in the primary combustion chamber and prevent coking caused by the eddy currents. Similarly, after the work is completed, the inner wall of the primary combustion chamber can be purged by the blower to prevent coking. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a front view of the present invention;

[0022] Figure 2 This is a top view of the present invention;

[0023] Figure 3 for Figure 2 Sectional view along line AA;

[0024] Figure 4 for Figure 3 Enlarged view of point B in the middle;

[0025] Figure 5 for Figure 3 Enlarged view of point C in the middle;

[0026] Figure 6 This is a partial cross-sectional view of the present invention.

[0027] Figure label:

[0028] 1. Burner housing; 2. Primary combustion chamber; 3. Secondary combustion chamber; 4. Plasma generator; 5. Secondary air box; 6. First impingement concentrate / decomposer block; 7. Second impingement concentrate / decomposer block; 8. Separation assembly; 81. First separator plate; 82. Second separator plate; 83. Through hole; 9. Secondary purging assembly; 91. Connecting cavity; 92. Blower head; 93. Connecting pipe; 10. Adjustment assembly; 101. Limiting rod; 102. Main adjusting rod; 103. Secondary adjusting rod; 104. Adjusting block; 105. First thread; 106. Connecting part; 107. Threaded part; 11. Ring sleeve; 12. Baffle plate; 13. Control valve. Detailed Implementation

[0029] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] The components of the embodiments of the invention described and shown in the accompanying drawings can typically be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0031] Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] The following is combined Figures 1 to 6 As shown, this embodiment of the invention provides a low-NOx burner with plasma-enhanced staged combustion, including a burner shell 1, a primary combustion chamber 2, a secondary combustion chamber 3, and a plasma generator 4. A secondary air box 5 is fitted outside the burner shell 1. A first impingement type concentration block 6 and a second impingement type concentration block 7 are respectively installed inside the primary combustion chamber 2 and the secondary combustion chamber 3. A separation component 8 for separating pulverized coal concentration is provided inside the burner shell 1. An adjustment component 10 for controlling the separation component 8 is also provided on the burner shell 1. A secondary purging component 9 is provided between the primary combustion chamber 2 and the secondary air box 5. The partition assembly 8 includes a first partition plate 81 and a second partition plate 82. The first partition plate 81 includes a straight portion and an arc-shaped portion. The straight portion is vertically disposed within the vertical portion of the burner housing 1, and the arc of the arc-shaped portion is the same as the arc at the corner of the burner housing 1. The second partition plate 82 is horizontally disposed within the horizontal portion of the burner housing 1. The end of the first partition plate 81 is hinged to the second partition plate 82, and both the first partition plate 81 and the second partition plate 82 are fixedly disposed within the burner housing 1 by the adjusting assembly 10. The first partition plate 81 is provided with a through hole 83 for the middle part of the plasma generator 4 to pass through.

[0035] During operation, primary air and pulverized coal are mixed and enter the burner housing 1 from one end. The pulverized coal is first separated into layers by the separating assembly 8, the first separating plate 81, and the second separating plate 82. The coal in the middle layer enters the primary combustion chamber 2 and is ignited by the plasma generator 4. The upper layer of coal enters the secondary combustion chamber 3 from the outside of the primary combustion chamber 2 for secondary ignition. However, variations in primary air velocity and pulverized coal quality can cause slight deviations in the pulverized coal concentration. While this doesn't necessarily affect the burner's function, it can impact performance and, in severe cases, cause coking inside the burner. In such cases, the positions of the first separating plate 81 and the second separating plate 82 can be adjusted using the adjusting assembly 10 to ensure that the coal in the middle always enters the primary combustion chamber 2 along its axis, resulting in more complete ignition and better performance. Furthermore, after operation, during cold air purging, the angle of the second separating plate 82 relative to the first separating plate 81 can be adjusted using the adjusting assembly 10 to guide the airflow towards the side wall of the primary combustion chamber 2, improving the purging effect.

[0036] Specifically, the adjustment assembly 10 includes a limiting rod 101, a main adjusting rod 102, and a secondary adjusting rod 103. The lower end of the limiting rod 101 is fixedly connected to the first partition plate 81, and the other end of the limiting rod 101 passes through the burner housing 1 and is slidably connected thereto. An adjusting block 104 is sleeved on the end of the limiting rod 101 located outside the burner housing 1. The lower end of the main adjusting rod 102 is rotatably connected to the burner housing 1. The upper part of the main adjusting rod 102 is provided with a first thread 105. The upper part of the main adjusting rod 102 is threadedly engaged with the adjusting block 104 through the first thread 105. The secondary adjusting rod 103 includes a lower connecting part 106 and an upper threaded part 107. The lower end of the connecting part 106 is hinged to the second partition plate 82, and the upper end of the connecting part 106 passes through the burner housing 1 and is slidably engaged thereto. The threaded part 107 is threadedly engaged with the adjusting block 104. Rotating the secondary adjusting rod 103, which is connected to the second partition plate 82, changes the angle between the second partition plate 82 and the first partition plate 81. This is mainly used to guide the purging air to purge various parts of the inner wall of the first-stage combustion chamber 2 after the work is completed. Simultaneously, to ensure that the up-and-down movement of the secondary adjusting rod 103 can change the angle of the second partition plate 82, the hinge between the first partition plate 81 and the second partition plate 82 should be relatively loose, meaning the second partition plate 82 can be finely adjusted along the axial direction of the first-stage combustion chamber 2. When the limiting rod 101 and the secondary adjusting rod 103 are stationary, rotating the main adjusting rod 102 moves the adjusting block 104, thereby causing the limiting rod 101 and the secondary adjusting rod 103 to move synchronously, thus synchronously adjusting the positions of the first partition plate 81 and the second partition plate 82 without changing the angle between them.

[0037] Specifically, the plasma generator 4 has a ring 11 in the middle, which is located at the through hole 83. Both the upper and lower ends of the ring 11 are provided with baffles 12. The two baffles 12 can block the excess part of the through hole 83 to avoid causing turbulence to the primary airflow.

[0038] Specifically, one end of each baffle 12 is rotatably connected to the ring 11 via a torsion spring. The baffle 12 is used to close the excess part of the through hole 83. Therefore, it is best if the baffle 12 is close to the first partition plate 81. Here, the baffle 12 is made of elastic material and will always rotate toward one side of the first partition plate 81 under the action of the torsion spring, so that the baffle 12 is in close contact with the first partition plate 81, which can better ensure the stability of the primary air supply inside the burner shell 1.

[0039] Specifically, one end of each baffle 12 is fixedly connected to the ring 11 via a spring sheet; the baffle 12 is used to close the excess part of the through hole 83, so it is best if the baffle 12 is close to the first partition plate 81. Here, the baffle 12 is made of elastic material, and under the elastic action of the spring sheet, it will always rotate toward one side of the first partition plate 81, so that the baffle 12 is in close contact with the first partition plate 81, which can better ensure the stability of the primary air supply inside the burner shell 1.

[0040] Specifically, the secondary purging assembly 9 includes a connecting cavity 91 disposed inside the first impact-type concentrate block 6. The first impact-type concentrate block 6 has several circumferentially distributed blowers 92 on the side facing the end of the first combustion chamber. A connecting pipe 93 connects the connecting cavity 91 and the secondary air box 5. During ignition, when air is supplied to the secondary air box 5, air is supplied to the primary combustion chamber 2 through the connecting pipe 93. This blowing helps alleviate eddies within the primary combustion chamber 2, further preventing coking caused by eddies. Similarly, after the operation is complete, the blowers 92 can be used to purge the inner wall of the primary combustion chamber 2 to prevent coking.

[0041] In this invention, the second impact-type concentration block 7 can also be designed with the same internal structure as the first impact-type concentration block 6, depending on the specific circumstances.

[0042] Specifically, the blowing direction of the blower head 92 is parallel to the axis of the first combustion cylinder, and the direction of the air blown out by the blower head 92 is the same as the direction of the air entering the first-stage combustion cylinder 2, so as to avoid affecting the airflow on the inner wall of the first-stage combustion cylinder 2.

[0043] Specifically, the blower head 92 is a one-way blower to avoid the reverse flow of airflow affecting the airflow inside the first-stage combustion chamber 2.

[0044] Specifically, a control valve 13 is provided at one end of the connecting pipe 93 located inside the secondary air box 5 to control the opening and closing of the connecting pipe 93. Since the secondary air box 5 delivers cold air, the temperature of the control valve 13 can be prevented from becoming too high, thus reducing the impact of high temperature on the control valve 13.

[0045] Specifically, the cross-sections of the first partition plate 81 and the second partition plate 82 are both arc-shaped. In addition to gathering coal powder in the vertical direction at a certain position for conveying, the first partition plate 81 and the second partition plate 82 can also gather coal powder on both sides towards the middle.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-NOx burner with plasma-enhanced staged combustion, comprising a burner shell (1), a primary combustion chamber (2), a secondary combustion chamber (3), and a plasma generator (4), wherein a secondary air box (5) is fitted outside the burner shell (1), and a first impingement enrichment block (6) and a second impingement enrichment block (7) are respectively provided inside the primary combustion chamber (2) and the secondary combustion chamber (3), characterized in that: The burner housing (1) is provided with a separation component (8) for separating the coal powder concentration. The burner housing (1) is also provided with an adjustment component (10) for controlling the separation component (8). A secondary purging component (9) is provided between the primary combustion tube (2) and the secondary air box (5). The partition assembly (8) includes a first partition plate (81) and a second partition plate (82). The first partition plate (81) includes a straight section and an arc section. The straight section is vertically arranged in the vertical section of the burner housing (1). The arc of the arc section is the same as the arc at the corner of the burner housing (1). The second partition plate (82) is horizontally arranged in the horizontal section of the burner housing (1). The end of the first partition plate (81) is hinged to the second partition plate (82). Both the first partition plate (81) and the second partition plate (82) are fixedly arranged in the burner housing (1) by the adjustment assembly (10). The first partition plate (81) is provided with a through hole (83) for the plasma generator (4) to pass through. The adjustment assembly (10) includes a limiting rod (101), a main adjusting rod (102), and a secondary adjusting rod (103). The lower end of the limiting rod (101) is fixedly connected to the first partition plate (81), and the other end of the limiting rod (101) passes through the burner housing (1) and is slidably connected to it. An adjusting block (104) is sleeved on one end of the limiting rod (101) located outside the burner housing (1). The lower end of the main adjusting rod (102) is rotatably connected to the burner housing (1). The upper part of the main adjusting rod (102) is provided with a first thread (105). The upper part of the main adjusting rod (102) is threadedly engaged with the adjusting block (104) through the first thread (105). The secondary adjusting rod (103) includes a lower connecting part (106) and an upper threaded part (107). The lower end of the connecting part (106) is hinged to the second partition plate (82). The upper end of the connecting part (106) penetrates the burner housing (1) and slides with it. The threaded part (107) is threadedly engaged with the adjusting block (104).

2. The low-NOx burner with plasma staged enhanced combustion according to claim 1, characterized in that: The plasma generator (4) has a ring (11) in the middle, which is located at the through hole (83). Both the upper and lower ends of the ring (11) are provided with baffles (12).

3. The low-NOx burner with plasma staged enhanced combustion according to claim 2, characterized in that: One end of each of the baffles (12) is rotatably connected to the ring sleeve (11) via a torsion spring.

4. The low-NOx burner with plasma staged enhanced combustion according to claim 2, characterized in that: One end of each of the baffles (12) is fixedly connected to the ring (11) by a spring.

5. The low-NOx burner with plasma staged enhanced combustion according to claim 1, characterized in that: The secondary purging assembly (9) includes a connecting cavity (91) disposed inside the first impact-type concentrate block (6). The first impact-type concentrate block (6) is provided with a plurality of circumferentially distributed blow heads (92) on the side facing the end of the first combustion tube. A connecting pipe (93) is provided between the connecting cavity (91) and the secondary air box (5).

6. The low-NOx burner with plasma staged enhanced combustion according to claim 5, characterized in that: The blowing direction of the blower head (92) is parallel to the axis of the first combustion cylinder.

7. The low-NOx burner with plasma staged enhanced combustion according to claim 5, characterized in that: The blower head (92) is for unidirectional airflow.

8. The low-NOx burner with plasma staged enhanced combustion according to claim 5, characterized in that: The connecting pipe (93) is equipped with a control valve (13) at one end inside the secondary air box (5).

9. The low-NOx burner with plasma staged enhanced combustion according to claim 1, characterized in that: The cross-sections of the first partition plate (81) and the second partition plate (82) are both arc-shaped.

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