Coal-pulverizing burner for power generation

Abstract

The utility model discloses a kind of flow coal powder combustors for power generation, it is related to the technical field of coal powder combustor.The utility model includes primary air pipe and secondary air box, the inlet of the primary air pipe is provided with elbow, the spout of the primary air pipe is hinged with two groups of expansion cone plate, two groups of expansion cone plate are V-shaped, elastic member is arranged between two groups of expansion cone plate, the inner wall of the spout of the primary air pipe is opened with two groups of ladder guide grooves, two groups of ladder guide grooves are respectively with two groups of expansion cone plate corresponding design, the inside of the primary air pipe is provided with adjustable wave baffle.The utility model is equipped with adjustable wave baffle, and the space of upper thick coal powder cavity and lower light coal powder cavity is changed using adjustable wave baffle telescoping, when coal powder granularity increases, adjustable wave baffle contracts, the space of upper thick coal powder cavity increases, the space of lower light coal powder cavity reduces, give thick coal powder more spacious transmission space, and wave height difference increases, promote dynamic change, guarantee combustion efficiency.

Description

Technical Field

[0001] This invention relates to the field of pulverized coal burner technology, and more specifically to a pulverized coal burner for power generation. Background Technology

[0002] A direct-flow burner consists of a set of rectangular or circular nozzles, and the primary and secondary air jets emitted are non-rotating direct-flow jets. Direct-flow burners can be arranged at the four corners of the furnace, the top of the furnace, or the arched part in the middle of the furnace, thus forming a tangential combustion mode at the four corners, a W-flame combustion mode, and a U-flame combustion mode.

[0003] The utility model patent (publication number: CN205957166U) discloses a nozzle device for a lean coal DC burner, including a nozzle head, an air inlet pipe, a burner shell, and an inlet elbow. The primary air pipe and the nozzle head are both located inside the burner shell. One end of the primary air pipe is connected to the nozzle head, and the other end is connected to the inlet elbow. A corrugated diffuser cone is installed inside the inlet elbow. The two diffuser vanes of the corrugated diffuser cone are arc-shaped with an arc of π / 12 to π / 6.

[0004] The patent and existing technologies have the following technical problems in practical use:

[0005] 1. The diffuser cones are all fixed. Fixed V-type diffuser cone burners have poor adaptability to different types of pulverized coal. When the pulverized coal particle size is large, the too small injection angle makes the pulverized coal too concentrated and difficult to disperse fully, affecting the combustion effect. When the pulverized coal particle size is small, the too large injection angle will cause the pulverized coal to diffuse excessively, resulting in incomplete combustion, reduced combustion efficiency and emission problems.

[0006] 2. In existing DC burners, when pulverized coal passes through the bend, centrifugal force will cause the formation of concentrated and diluted pulverized coal areas inside the primary air duct. When the pulverized coal particle size is large, it tends to shift towards the outer wall of the duct, forming a relatively concentrated concentrated pulverized coal area. This results in a high concentration of concentrated pulverized coal inside the duct, which easily leads to pulverized coal deposition inside the duct. Poor uniformity of pulverized coal delivery will also affect combustion efficiency. Summary of the Invention

[0007] The purpose of this invention is to provide a pulverized coal burner for power generation in order to solve the above problems.

[0008] To achieve the above objectives, the present invention specifically adopts the following technical solution:

[0009] A pulverized coal burner for power generation includes a primary air duct and a secondary air box. The inlet of the primary air duct is provided with an elbow. Two sets of expanding cone plates are hinged at the nozzle of the primary air duct. The two sets of expanding cone plates are V-shaped and an elastic element is provided between the two sets of expanding cone plates. The inner wall of the nozzle of the primary air duct is provided with two sets of stepped guide grooves, which are designed to correspond to the two sets of expanding cone plates respectively.

[0010] The primary air duct is equipped with an adjustable corrugated baffle, which divides the primary air duct into an upper concentrated pulverized coal cavity and a lower dilute pulverized coal cavity. The adjustable corrugated baffle can be expanded and retracted. When retracted, the space of the concentrated pulverized coal cavity on the adjustable corrugated baffle increases and the space of the lower dilute pulverized coal cavity decreases. Two sets of transmission guide plates are hinged to one end of the adjustable corrugated baffle near the expanding cone plate. A limit post is provided at the end of the transmission guide plate near the expanding cone plate, and the limit post is inserted into the stepped guide groove.

[0011] Furthermore, the elastic element is a concave spring sheet.

[0012] Furthermore, the adjustable wave baffle is composed of a fixed inner rod, multiple sets of movable inner rods, and two sets of outer thin plates. The fixed inner rod and the movable inner rod are welded between the two sets of outer thin plates. The multiple sets of movable inner rods can be brought together towards the fixed inner rod. A fixed rod and a guide are fixedly installed inside the primary air duct. A guide roller is rotatably installed inside the guide. The two sets of outer thin plates are bent towards the fixed rod through the gap between the guide and the guide roller. A tension spring is provided between the fixed rod and the outer thin plate. A hinge is provided on the outer side of the movable inner rod closest to the expansion cone plate. The two sets of transmission guide plates are simultaneously hinged to the hinge.

[0013] Furthermore, the outer thin plate is welded to the transmission guide plate.

[0014] Furthermore, an inner frame is provided between the fixed inner rod and the movable inner rod, and between adjacent movable inner rods. The inner frame is composed of multiple horizontally parallel elastic bars, and a support bar is provided longitudinally in the middle of the multiple horizontally parallel elastic bars.

[0015] Furthermore, a guide opening is provided through the inner wall of the primary air duct, and a sealing slide is slidably connected inside the guide opening. The sealing slide has an H-shaped design, and an adjusting nut is provided on the outer side of the sealing slide. An adjusting motor is fixedly installed on the outer side of the primary air duct, close to the inlet of the primary air duct. An adjusting shaft is fixedly installed on the output end of the adjusting motor, and multiple sets of adjusting threads are provided on the outer side of the adjusting shaft. The adjusting nut is threadedly connected to the adjusting threads.

[0016] Furthermore, the thread pitch of the multiple sets of adjusting threads is the same.

[0017] Furthermore, the thread pitch of the multiple sets of adjusting threads decreases sequentially from the outside to the inside, and the thread pitch of the outer side is twice the thread pitch of the adjacent inner side.

[0018] Furthermore, the guide port is located in the lower pulverized coal cavity, and the sealing slide is connected to the movable inner rod via an extension rod.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. The present invention adopts an adjustable corrugated baffle, which makes the inner bottom of the concentrated coal powder cavity have a corrugated design. This allows the coal powder to form an irregular flow path along the bottom of the pipe during the transportation process. Compared with the flat bottom of the pipe, the corrugated shape makes the coal powder flow more dynamic and avoids the coal powder from stagnating at the bottom of the pipe. During the flow, the coal powder will "jump" or roll along the bottom of the corrugated shape with the undulation of the wave, thereby reducing the coal powder from staying in one position for a long time and reducing the possibility of settling.

[0021] 2. This invention employs an adjustable corrugated baffle. The expansion and contraction of the adjustable corrugated baffle changes the space between the upper concentrated pulverized coal cavity and the lower dilute pulverized coal cavity. As the particle size of the pulverized coal increases, the adjustable corrugated baffle contracts, increasing the space of the upper concentrated pulverized coal cavity and decreasing the space of the lower dilute pulverized coal cavity, providing a wider transmission space for the concentrated pulverized coal. Furthermore, the increased wave height difference enhances dynamic changes, enabling more efficient transportation of the concentrated pulverized coal and ensuring combustion efficiency.

[0022] 3. The present invention, through the setting of the transmission guide plate, allows the adjustable wave baffle to move while adjusting, and the transmission guide plate to move the limiting column in the stepped guide groove. The limiting column first slides a distance along the outer surface of the expanding cone plate and then moves away from the expanding cone plate. At this time, the setting of the internal elastic element of the expanding cone plate allows the angle of the expanding cone plate to change synchronously, so that the cavity adjustment and the expanding cone plate angle adjustment are coordinated. The DC burner can better adapt to different coal powder particle sizes and has a good combustion effect. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 1 ;

[0024] Figure 2 This is a schematic diagram of the three-dimensional structure of the present invention. Figure 2 ;

[0025] Figure 3 This is a schematic cross-sectional view of the overall structure of the present invention;

[0026] Figure 4 This is a schematic cross-sectional view of the primary air duct structure of the present invention;

[0027] Figure 5 This is a schematic diagram of the adjustable wave baffle structure of the present invention;

[0028] Figure 6 This is an exploded view of the adjustable wave baffle of the present invention;

[0029] Figure 7 This is a schematic diagram of the internal skeleton structure of the present invention;

[0030] Figure 8 This is a schematic diagram of the guide component structure of the present invention.

[0031] Reference numerals in the attached diagram: 1. Primary air duct; 11. Guide port; 12. Stepped guide groove; 13. Adjusting motor; 14. Adjusting shaft; 2. Secondary air box; 3. Expanding cone plate; 31. Concave spring; 4. Fixed inner rod; 5. Movable inner rod; 51. Sealing slide; 52. Adjusting nut; 53. Hinge; 6. Inner frame; 7. Outer thin plate; 8. Transmission guide plate; 81. Limiting post; 9. Fixed rod; 91. Tension spring; 10. Guide component; 101. Guide roller. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] Example 1, as Figures 1-8 As shown, a pulverized coal burner for power generation includes a primary air duct 1 and a secondary air box 2. The inlet of the primary air duct 1 is provided with an elbow. Two sets of expanding cone plates 3 are hinged at the nozzle of the primary air duct 1. The two sets of expanding cone plates 3 are V-shaped. An elastic element is provided between the two sets of expanding cone plates 3. Two sets of stepped guide grooves 12 are opened on the inner wall of the nozzle of the primary air duct 1. The two sets of stepped guide grooves 12 are designed to correspond to the two sets of expanding cone plates 3 respectively.

[0034] An adjustable corrugated baffle is installed inside the primary air duct 1. The adjustable corrugated baffle divides the primary air duct 1 into an upper concentrated pulverized coal cavity and a lower dilute pulverized coal cavity. The adjustable corrugated baffle can be expanded and retracted. When retracted, the space of the concentrated pulverized coal cavity on the adjustable corrugated baffle increases and the space of the lower dilute pulverized coal cavity decreases. Two sets of transmission guide plates 8 are hinged to one end of the adjustable corrugated baffle near the expanding cone plate 3. A limit post 81 is provided at one end of the transmission guide plate 8 near the expanding cone plate 3. The limit post 81 is inserted into the stepped guide groove 12.

[0035] Powdered coal enters through a bend. Under centrifugal force, the coal powder tends to shift towards the outer wall of the pipe, forming a relatively concentrated area of ​​concentrated coal powder. This results in an upper concentrated coal powder cavity and a lower diluted coal powder cavity. Through the design of an adjustable corrugated baffle, the inner bottom of the upper concentrated coal powder cavity is corrugated, which allows the coal powder to form an irregular flow path along the bottom of the pipe during transportation. Compared with a flat pipe bottom, the corrugated shape makes the coal powder flow more dynamic and avoids the coal powder from stagnating at the bottom of the pipe. During the flow, the coal powder will "jump" or roll along the bottom of the corrugated shape with the undulation of the wave, thereby reducing the coal powder from staying in one position for a long time and reducing the possibility of settling.

[0036] It should be noted that this invention requires the use of an existing online particle size analyzer to monitor coal powder particle size in real time. The Winner7303 online particle size analyzer is preferred. This device can collect samples on-site using a coal powder sampler. After the sampler extracts the coal powder sample, it is transferred to the testing host via a ceramic pipeline. The host tests and analyzes the coal powder sample, and then controls the expansion and contraction of the adjustable corrugated baffle based on the analysis results. When the coal powder particle size is large, the adjustable corrugated baffle contracts, increasing the upper cavity space for concentrated coal powder and decreasing the lower cavity space for less concentrated coal powder, providing a wider transmission space for the concentrated coal powder. The increased wave height difference enhances dynamic changes, enabling more efficient transport of the concentrated coal powder and more uniform spraying, ensuring combustion efficiency. Simultaneously, the contraction of the adjustable corrugated baffle drives the transmission guide plate 8 to move, which in turn drives the limiting post 81 in the stepped guide groove 12. The stepped guide trough 12 is composed of multiple sets of inclined grooves. These grooves, from top to bottom, are parallel to the outer surface of the expanding cone plate 3 at different angles. Therefore, the limiting post 81 first slides a distance along the outer surface of the expanding cone plate 3, and then enters the next inclined groove. At this time, under the action of the elastic element, the two sets of expanding cone plates 3 unfold, increasing the angle. The expanding cone plates 3 then press against the limiting post 81 again. Because the adjustable corrugated baffle has a large deformation, while the expanding cone plate 3 changes angle only slightly, the transmission guide plate 8 needs a long moving distance, but it cannot cause a large angle change in the expanding cone plate 3. Therefore, the stepped guide trough 12 allows the deformation of the adjustable corrugated baffle to coordinate with the angle adjustment of the expanding cone plate 3, improving the consistency of the device while reducing the difficulty of adjusting the angle of the expanding cone plate 3 under high-temperature conditions. This allows for better adaptation to coal powder of different particle sizes, resulting in better combustion. It should be noted that the transmission guide plate 8 is oscillating, thus allowing the limiting post 81 to slide stably along the inclined groove of the stepped guide trough 12.

[0037] When the coal powder particle size is small, the adjustable corrugated baffle extends, the downward concave part of the adjustable corrugated baffle decreases, the upper dense coal powder cavity space decreases, the lower light coal powder cavity space increases, ensuring the flow stability of the lower light coal powder cavity, and at the same time the expansion cone plate 3 decreases.

[0038] The angle of the expanding cone plate 3 increases the coal powder so that it can be fully dispersed and burned evenly; when the coal powder particle size is small, the angle of the expanding cone plate 3 decreases so that the coal powder will not diffuse excessively and burn completely.

[0039] Example 2, based on the above examples, further includes an elastic element using a concave spring sheet 31. This design makes the backflow zone stronger, achieving a stable ignition effect, while also sealing and blocking the space between the expansion cone plates 3 to prevent flue gas from flowing back into the pipe.

[0040] Example 3, based on the above examples, further includes an adjustable wave baffle composed of a fixed inner rod 4, multiple sets of movable inner rods 5, and two sets of outer thin plates 7. The fixed inner rod 4 and the movable inner rods 5 are welded between the two sets of outer thin plates 7. The multiple sets of movable inner rods 5 can be brought together towards the fixed inner rod 4. A fixed rod 9 and a guide member 10 are fixedly installed inside the primary air duct 1. A guide roller 101 is rotatably installed inside the guide member 10. The two sets of outer thin plates 7 are bent towards the fixed rod 9 through the gap between the guide member 10 and the guide roller 101. A tension spring 91 is provided between the fixed rod 9 and the outer thin plate 7. A hinge member 53 is provided on the outer side of the movable inner rod 5 closest to the expanding cone plate 3. The two sets of transmission guide plates 8 are simultaneously hinged to the hinge member 53.

[0041] Furthermore, the outer thin plate 7 is welded onto the transmission guide plate 8 to improve sealing, and the outer thin plate 7 has a certain elasticity so as not to affect the swing of the transmission guide plate 8.

[0042] Furthermore, an inner frame 6 is provided between the fixed inner rod 4 and the movable inner rod 5, and between adjacent movable inner rods 5. The inner frame 6 is composed of multiple horizontally parallel elastic bars, and a support bar is provided longitudinally in the middle of the multiple horizontally parallel elastic bars.

[0043] This embodiment provides a specific adjustable corrugated baffle structure. When retracted, the movable inner rod 5 is simultaneously brought together with the fixed inner rod 4, and adjacent movable inner rods 5 are also brought together. The outer thin plate 7 is recessed downwards, increasing the cavity space of the upper concentrated coal powder while increasing the wave height difference of the adjustable corrugated baffle. At the same time, it is necessary to ensure that the overall separation length of the adjustable corrugated baffle remains unchanged. Therefore, by setting the double-layer outer thin plate 7, the outer thin plate 7 can be bent and stored inside, storing the extension length inside. Under the action of the guide member 10 and the guide roller 101, the extension and contraction are stable, thus ensuring that the separation length of the adjustable corrugated baffle remains unchanged when it extends and contracts, resulting in a good adjustment effect.

[0044] Furthermore, the inner frame 6 ensures that the outer thin plate 7 will not deform due to wind force after being recessed, thus ensuring stable coal powder transportation.

[0045] Example 4, based on the above examples, further includes a guide opening 11 through the inner wall of the primary air duct 1, a sealing slide 51 slidably connected inside the guide opening 11, the sealing slide 51 having an H-shaped design, an adjusting nut 52 provided on the outer side of the sealing slide 51, an adjusting motor 13 fixedly installed on the outer side of the primary air duct 1, the adjusting motor 13 being close to the inlet of the primary air duct 1, an adjusting shaft 14 fixedly installed at the output end of the adjusting motor 13, multiple sets of adjusting threads being provided on the outer side of the adjusting shaft 14, and the adjusting nut 52 being threadedly connected to the adjusting threads.

[0046] This embodiment is an adjustable wave baffle adjustment drive structure. By controlling the adjustment motor 13 to be energized, the adjustment motor 13 drives multiple sets of adjustment nuts 52 to move synchronously through the adjustment thread. The multiple sets of adjustment nuts 52 drive multiple sets of movable inner rods 5 to move closer to or away from the fixed inner rod 4 simultaneously through the sealing slide 51.

[0047] Example 5, based on the above examples, further includes multiple sets of adjusting threads with the same thread pitch.

[0048] Through the design of this embodiment, during adjustment, adjacent waves can be made different, which can better increase the mutual disturbance between pulverized coal and airflow, so that the pulverized coal maintains a higher fluidity and suspension state in the pipeline. It should be noted that the adjustment threads on both sides of the fixed inner rod 4 have opposite rotation directions.

[0049] Example 6, based on the above examples, further includes multiple sets of adjusting threads with the thread pitch decreasing sequentially from the outside to the inside, and the outer thread pitch being twice the adjacent inner thread pitch.

[0050] With the design of this embodiment, the waves are uniform and consistent during adjustment, which can better ensure the stability of the flow and facilitate control. It should be noted that the adjustment threads on both sides of the fixed inner rod 4 have opposite rotation directions.

[0051] Example 7, based on the above examples, further includes a guide port 11 located in the lower pulverized coal cavity, and a sealing slide 51 connected to the movable inner rod 5 via an extension rod.

[0052] By setting the guide port 11 and the sealing slide 51 in the lower light coal powder cavity through this embodiment, the impact on the overall coal powder ejection is reduced.

[0053] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A pulverized coal burner for power generation, comprising a primary air duct (1) and a secondary air box (2), characterized in that, The inlet of the primary air duct (1) is provided with an elbow, and two sets of expanding cone plates (3) are hinged at the nozzle of the primary air duct (1). The two sets of expanding cone plates (3) are V-shaped, and an elastic element is provided between the two sets of expanding cone plates (3). Two sets of stepped guide grooves (12) are opened on the inner wall of the nozzle of the primary air duct (1). The two sets of stepped guide grooves (12) are designed to correspond to the two sets of expanding cone plates (3). The primary air duct (1) is equipped with an adjustable corrugated baffle. The adjustable corrugated baffle divides the primary air duct (1) into an upper concentrated coal powder cavity and a lower light coal powder cavity. The adjustable corrugated baffle can be expanded and retracted. When retracted, the space of the concentrated coal powder cavity on the adjustable corrugated baffle increases and the space of the lower light coal powder cavity decreases. Two sets of transmission guide plates (8) are hinged to one end of the adjustable corrugated baffle near the expansion cone plate (3). A limit post (81) is provided at one end of the transmission guide plate (8) near the expansion cone plate (3). The limit post (81) is inserted into the stepped guide groove (12).

2. The pulverized coal burner for power generation according to claim 1, characterized in that, The elastic element is a concave spring sheet (31).

3. A pulverized coal burner for power generation according to claim 1, characterized in that, The adjustable wave baffle is composed of a fixed inner rod (4), multiple sets of movable inner rods (5) and two sets of outer thin plates (7). The fixed inner rod (4) and movable inner rods (5) are welded between the two sets of outer thin plates (7). The multiple sets of movable inner rods (5) can be brought together with the fixed inner rod (4). The primary air duct (1) is fixedly installed with a fixed rod (9) and a guide (10). The guide roller (101) is rotatably installed inside the guide (10). The two sets of outer thin plates (7) bend towards the fixed rod (9) through the gap between the guide (10) and the guide roller (101). A tension spring (91) is provided between the fixed rod (9) and the outer thin plate (7). A hinge (53) is provided on the outside of the movable inner rod (5) closest to the expansion cone plate (3). The two sets of transmission guide plates (8) are simultaneously hinged on the hinge (53).

4. A pulverized coal burner for power generation according to claim 3, characterized in that, The outer thin plate (7) is welded onto the transmission guide plate (8).

5. A pulverized coal burner for power generation according to claim 4, characterized in that, An inner frame (6) is provided between the fixed inner rod (4) and the movable inner rod (5), and between adjacent movable inner rods (5). The inner frame (6) is composed of multiple horizontally parallel elastic bars, and a support bar is provided in the middle of the multiple horizontally parallel elastic bars.

6. A pulverized coal burner for power generation according to claim 5, characterized in that, The inner wall of the primary air duct (1) is provided with a guide opening (11). A sealing slide (51) is slidably connected inside the guide opening (11). The sealing slide (51) is H-shaped. An adjusting nut (52) is provided on the outer side of the sealing slide (51). An adjusting motor (13) is fixedly installed on the outer side of the primary air duct (1). The adjusting motor (13) is close to the inlet of the primary air duct (1). An adjusting shaft (14) is fixedly installed at the output end of the adjusting motor (13). Multiple sets of adjusting threads are opened on the outer side of the adjusting shaft (14). The adjusting nut (52) is threadedly connected to the adjusting threads.

7. A pulverized coal burner for power generation according to claim 6, characterized in that, The thread pitch of the multiple sets of adjusting threads is the same.

8. A pulverized coal burner for power generation according to claim 6, characterized in that, The thread pitch of the multiple sets of adjusting threads decreases sequentially from the outside to the inside, and the thread pitch of the outer side is twice the thread pitch of the adjacent inner side.

9. A pulverized coal burner for power generation according to any one of claims 6-8, characterized in that, The guide port (11) is located in the lower light coal powder cavity, and the sealing slide (51) is connected to the movable inner rod (5) through the extension rod.

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