Turbulent burner based on large-proportion blending burning of lignite and application of turbulent burner

Abstract

The invention relates to the technical field of boiler combustors, and discloses a cyclone combustor based on large-proportion blending combustion of lignite. The primary air pipe is arranged on the peripheral side of the central air pipe in a sleeving mode and connected with a pulverized coal inlet elbow, the pulverized coal inlet elbow is connected with an eccentric pipe, and the axis of the eccentric pipe is located on the rear side of the axis of the pulverized coal inlet elbow; and the secondary air pipe is sleeved on the outer side of the central air pipe. In addition, the invention further discloses application of the cyclone burner based on large-proportion lignite blending combustion. Primary air pulverized coal airflow from a coal mill is accelerated through an eccentric pipe in front of a burner elbow, and due to the action of centrifugal force, about 50% of primary air and about 15% of pulverized coal enter a hearth through a waste steam nozzle. And the remaining primary air and pulverized coal enter the hearth through the primary air nozzle. The pulverized coal is ignited through inner secondary air, and then the pulverized coal is fully combusted through a large amount of outer secondary air. By the adoption of the air distribution mode, stable combustion of the hearth is guaranteed, and generation of NOx is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of boiler burners, in particular to a swirl burner based on large-proportion blending of lignite and applications thereof. Background Art

[0003] Research shows that the primary air rate of a power plant boiler burner can reach about 40% during actual operation. The higher the primary air rate, the higher the fuel-type NOx emissions. The larger the primary air rate, the smaller the corresponding secondary air rate. At the same time, in order to make the secondary air rate and the primary air rate match appropriately and organize combustion reasonably, it is impossible to separate more burnout air and achieve deep graded combustion. In view of this, excessively high primary air rate is the main reason for high NOx emissions.

[0004] In view of this, how to change the current situation that the primary air rate of the power plant boiler burner is too high has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0005] The present invention aims to provide a swirl burner based on large-proportion brown coal blending and application thereof, so as to overcome the above-mentioned shortcomings.

[0006] In order to achieve the above object, the first aspect of the present invention provides a swirl burner based on large proportion of lignite blending, comprising:

[0007] Central air duct;

[0008] a primary air duct sleeved on the peripheral side of the central air duct, the primary air duct being connected to a pulverized coal inlet elbow, the pulverized coal inlet elbow being connected to an eccentric pipe, the axis of the eccentric pipe being located at the rear side of the axis of the pulverized coal inlet elbow; and

[0009] A secondary air duct is sleeved on the outside of the central air duct.

[0010] Furthermore, the secondary air duct includes an inner secondary air duct and an outer secondary air duct which are arranged in sequence from the inside to the outside, and the inner secondary air duct and the outer secondary air duct are both sleeved on the circumference of the primary air duct.

[0011] Furthermore, an inner secondary air box is connected to the outer side of the primary air duct, a secondary air cyclone is provided at the opening of the inner secondary air box, the opening of the inner secondary air box is communicated with the inner secondary air duct, and the inner secondary air box is provided with an air inlet.

[0012] Furthermore, an adjusting damper for adjusting the size of the air inlet is provided on the peripheral side of the inner secondary air box.

[0013] Furthermore, it also includes a damper adjustment mechanism, and the damper adjustment mechanism includes:

[0014] A bellows panel fixedly connected to the outer side wall of the primary air duct;

[0015] A first guide sleeve fixedly connected to the bellows panel; and

[0016] A first adjusting rod slides through the first guide sleeve, the first adjusting rod is arranged along the axis direction of the central air duct, one end of the first adjusting rod is fixedly connected to the adjusting damper, and the other end of the first adjusting rod is connected to a first handle.

[0017] Furthermore, it also includes:

[0018] A second guide sleeve fixedly connected to the bellows panel; and

[0019] A second adjusting rod slides through the second guide sleeve, one end of the second adjusting rod passes through the inner secondary air box and is connected to an air adjusting ring, the air adjusting ring is located at the rear side of the secondary air cyclone, and the other end of the second adjusting rod is connected to a second handle.

[0020] Furthermore, the air outlets of the inner secondary air duct and the outer secondary air duct are both provided with flaring, and the flaring angles of the inner secondary air duct and the outer secondary air duct are 0° to 30°.

[0021] Furthermore, a plurality of combustion stabilizing teeth evenly distributed along the circumferential direction are provided at the air outlet of the central air duct, and a combustion stabilizing ring is provided at the air outlet of the primary air duct.

[0022] Furthermore, a wear-resistant layer is installed on the outer wall of the central air duct, and a wear-resistant layer is provided on the inner wall of the primary air duct and the inner wall of the pulverized coal inlet elbow.

[0023] Compared with the prior art, the swirl burner based on large proportion of lignite blending and its application in the present invention has the following advantages:

[0024] The primary air and pulverized coal flow from the coal mill is accelerated through the eccentric tube in front of the burner elbow. Due to the centrifugal force, about 50% of the primary air and about 15% of the pulverized coal enter the furnace through the exhaust steam nozzle. The remaining primary air and pulverized coal enter the furnace through the primary air nozzle. The pulverized coal is first ignited by the internal secondary air, and then fully burned by a large amount of external secondary air. The secondary air itself has a swirl strength, which can entrain high-temperature flue gas and provide sufficient ignition heat for the pulverized coal, igniting it and burning it stably. This air distribution method not only ensures stable combustion in the furnace, but also reduces the generation of NOx.

[0025] The second aspect of the present invention provides an application of a swirl burner based on large-proportion brown coal blending, which can be applied in the field of thermal power generation.

[0026] The application of the swirl burner based on large proportion of lignite blending is the same as the advantages of the swirl burner based on large proportion of lignite blending over the prior art, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 This is a schematic diagram of the overall structure of the swirl burner based on large-proportion blending of lignite according to the present invention;

[0029] Figure 2 It is a cross-sectional view of a swirl burner based on large proportion of lignite blending according to the present invention.

[0030] Figure numerals: 1. central air duct; 2. primary air duct; 3. pulverized coal inlet elbow; 4. eccentric pipe; 5. inner secondary air duct; 6. outer secondary air duct; 7. inner secondary air box; 8. secondary air cyclone; 9. air inlet; 10. adjusting damper; 11. bellows panel; 12. first guide sleeve; 13. first adjusting rod; 14. first handle; 15. second guide sleeve; 16. second adjusting rod; 17. second handle; 18. air adjusting ring; 19. combustion stabilizing teeth; 20. combustion stabilizing ring. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] Reference Figure 1-2The present invention provides a first aspect, which provides a swirl burner based on large-proportion brown coal blending, including a central air duct 1, a primary air duct 2 and a secondary air duct. Among them, the central air duct 1 is the core part of the burner, responsible for evenly distributing the air into the combustion chamber; the primary air duct 2 and the coal powder inlet elbow 3 ensure that the coal powder can evenly enter the combustion chamber and mix with the air to achieve effective combustion. The design of the eccentric tube 4 helps to optimize the mixing of coal powder and air. The secondary air duct is sleeved on the outside of the central air duct 1, and is divided into an inner secondary air duct 5 and an outer secondary air duct 6, which further promote the mixing of air and coal powder and help control the shape and temperature of the flame.

[0034] The primary air and pulverized coal flow from the coal mill is accelerated through the eccentric tube 4 in front of the burner elbow. Due to the centrifugal force, about 50% of the primary air and about 15% of the pulverized coal enter the furnace through the exhaust steam nozzle. The remaining primary air and pulverized coal enter the furnace through the primary air nozzle. The pulverized coal is first ignited by the internal secondary air, and then fully burned by a large amount of external secondary air. The secondary air itself has a swirl strength, through which the high-temperature flue gas can be entrained, providing sufficient ignition heat for the pulverized coal, igniting it and burning it stably. This air distribution method not only ensures the stable combustion of the furnace, but also reduces the generation of NOx.

[0035] Preferably, the secondary air duct includes an inner secondary air duct 5 and an outer secondary air duct 6 which are arranged in sequence from the inside to the outside, and the inner secondary air duct 5 and the outer secondary air duct 6 are both sleeved on the circumference of the primary air duct 2 .

[0036] The present invention adopts an air control device to maintain the balance of air volume between the burners in operation and the reasonable distribution of the secondary air volume inside and outside a single burner.

[0037] Furthermore, the outer side of the primary air duct 2 is connected to an inner secondary air box 7, and a secondary air cyclone 8 is provided at the opening of the inner secondary air box 7. The opening of the inner secondary air box 7 is communicated with the inner secondary air duct 5, and the inner secondary air box 7 is provided with an air inlet 9.

[0038] In order to adjust the size of the air inlet 9 , an adjusting damper 10 for adjusting the size of the air inlet 9 is provided on the peripheral side of the inner secondary air box 7 .

[0039] In addition, the device also includes a damper adjustment mechanism, which includes: a bellows panel 11 fixedly connected to the outer side wall of the primary air duct 2; a first guide sleeve 12 fixedly connected to the bellows panel 11; and a first adjustment rod 13 slidingly passing through the first guide sleeve 12, and the first adjustment rod 13 is arranged along the axis direction of the central air duct 1. One end of the first adjustment rod 13 is fixedly connected to the damper 10, and the other end of the first adjustment rod 13 is connected to a first handle 14.

[0040] In addition, there are the following components: a second guide sleeve 15 fixedly connected to the air box panel 11; and a second adjustment rod 16 slidingly passing through the second guide sleeve 15, one end of the second adjustment rod 16 passing through the inner secondary air box 7 is connected to an air adjustment ring 18. The air adjustment ring 18 is located at the rear side of the secondary air cyclone 8, and the other end of the second adjustment rod 16 is connected to a second handle 17.

[0041] The air outlets of the inner secondary air duct 5 and the outer secondary air duct 6 are both provided with expansion ports, and the expansion angles of the inner secondary air duct 5 and the outer secondary air duct 6 are 10° to 30°.

[0042] A plurality of combustion stabilizing teeth 19 evenly distributed along the circumferential direction are provided at the air outlet of the central air duct 1 , and a combustion stabilizing ring 20 is provided at the air outlet of the primary air duct 2 .

[0043] Optionally, a wear-resistant layer is installed on the outer wall of the central air duct 1, and a wear-resistant layer is installed on the inner wall of the primary air duct 2 and the inner wall of the pulverized coal inlet elbow 3.

[0044] The present invention provides a second aspect that provides an application of a swirl burner based on the large proportion of lignite blended combustion. The swirl burner based on the large proportion of lignite blended combustion can be applied in the field of thermal power generation.

[0045] The application of the swirl burner based on large proportion of lignite blending is the same as the advantages of the swirl burner based on large proportion of lignite blending over the prior art, which will not be repeated here.

[0046] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0047] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. Based on the large proportion of lignite blending swirl burner, it is characterized by: include: Central air duct (1); a primary air duct (2) sleeved on the peripheral side of the central air duct (1), the primary air duct (2) being connected to a coal powder inlet elbow (3), the coal powder inlet elbow (3) being connected to an eccentric tube (4), the axis of the eccentric tube (4) being located at the rear side of the axis of the coal powder inlet elbow (3); and A secondary air duct is sleeved on the outside of the central air duct (1).

2. The swirl burner based on large proportion of lignite blending according to claim 1 is characterized in that: The secondary air duct comprises an inner secondary air duct (5) and an outer secondary air duct (6) which are arranged in sequence from the inside to the outside, and the inner secondary air duct (5) and the outer secondary air duct (6) are both sleeved on the circumference of the primary air duct (2).

3. The swirl burner based on large proportion of lignite blending according to claim 2 is characterized in that: The outer side of the primary air duct (2) is connected to an inner secondary air box (7), a secondary air cyclone (8) is provided at the opening of the inner secondary air box (7), the opening of the inner secondary air box (7) is connected to the inner secondary air duct (5), and the inner secondary air box (7) is provided with an air inlet (9).

4. The swirl burner based on large proportion of lignite blending according to claim 3 is characterized in that: An adjusting damper (10) for adjusting the size of the air inlet (9) is arranged on the peripheral side of the inner secondary air box (7).

5. The swirl burner based on large proportion of lignite blending according to claim 4 is characterized in that: It also includes a damper adjustment mechanism, the damper adjustment mechanism comprising: A bellows panel (11) fixedly connected to the outer side wall of the primary air duct (2); a first guide sleeve (12) fixedly connected to the bellows panel (11); and A first adjusting rod (13) is slidably passed through the first guide sleeve (12), the first adjusting rod (13) is arranged along the axial direction of the central air duct (1), one end of the first adjusting rod (13) is fixedly connected to the adjusting damper (10), and the other end of the first adjusting rod (13) is connected to a first handle (14).

6. The swirl burner based on large proportion of lignite blending according to claim 5 is characterized in that: Also includes: A second guide sleeve (15) fixedly connected to the bellows panel (11); as well as A second adjusting rod (16) is slidably passed through the second guide sleeve (15), one end of the second adjusting rod (16) passes through the inner secondary air box (7) and is connected to an air adjusting ring (18), the air adjusting ring (18) is located at the rear side of the secondary air cyclone (8), and the other end of the second adjusting rod (16) is connected to a second handle (17).

7. The swirl burner based on large proportion of brown coal blending according to claim 6 is characterized in that: The air outlets of the inner secondary air duct (5) and the outer secondary air duct (6) are both provided with expansion ports, and the expansion angles of the inner secondary air duct (5) and the outer secondary air duct (6) are in the range of 10° to 30°.

8. The swirl burner based on large proportion of lignite blending according to claim 1 is characterized in that: A plurality of combustion stabilizing teeth (19) evenly distributed along the circumferential direction are provided at the air outlet of the central air duct (1), and a combustion stabilizing ring (20) is provided at the air outlet of the primary air duct (2).

9. The swirl burner based on large proportion of brown coal blending according to claim 1 is characterized in that: The outer wall of the central air duct (1) is provided with a wear-resistant layer, and the inner wall of the primary air duct (2) and the inner wall of the pulverized coal inlet elbow (3) are both provided with a wear-resistant layer.

10. Application of the swirl burner based on large proportion of lignite blending as claimed in any one of claims 1 to 9 in the field of thermal power generation.

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