Adjusting device for secondary air bellow of opposed firing coal-fired boiler

Abstract

The utility model provides an adjusting device for a secondary air bellow of an opposed firing coal-fired boiler. The adjusting device comprises two main air ducts, two lateral air ducts, two groups of first shunting assemblies, two groups of second shunting assemblies, a front wall body and a rear wall body, the input end of each main air duct communicates with the air pre-heater, and the output end of each main air duct outputs secondary air to the front wall body and the rear wall body. Each lateral air duct comprises a forward air duct and a backward air duct, the forward air duct is communicated with the main air duct and the front wall body, and the backward air duct is communicated with the front wall body and the rear wall body; each group of first shunting assemblies divides each main air duct into a plurality of sub air ducts; and each group of the second shunting assemblies is used for shunting the secondary air output by each main air duct. According to the air pre-heater, through the first flow dividing assembly arranged in the main air duct and the second air flow assembly arranged in the lateral air duct, the air volumes of secondary air flowing into the front wall body and the rear wall body of the air pre-heater are equal, and insufficient combustion in the rear wall body is avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of thermal power generation, and in particular relates to a regulating device for a secondary air box of a hedging coal-fired boiler. Background Art

[0002] Pulverized coal boilers, a core component of thermal power generation, typically use either direct current or swirl burners to burn coal. Direct current burners have a nearly square furnace cross-section and typically employ a "square-cut circle" combustion method. Swirl burners have a rectangular furnace cross-section and typically employ a "counter-compression" combustion method, including front-to-back wall counter-compression and W-shaped flames.

[0003] A boiler with counterfired front and rear walls features three layers of burners on each of the front and rear walls of the furnace. The number of burners on each layer is determined by the boiler's capacity. This method enhances the agitation and mixing of the pulverized coal airflow, increasing the fullness of the airflow within the furnace. This results in a more uniform distribution of heat load and flue gas temperature across the width of the furnace, helping to reduce left-right flue gas temperature deviations at the furnace outlet.

[0004] The stability of boiler combustion is closely linked to air distribution control, with secondary air, in particular, having the greatest impact on combustion. Uneven secondary air distribution can easily lead to a range of problems, including localized furnace oxygen deficiency, flame deflection, water-wall overheating, and high-temperature corrosion. Currently, the secondary air systems of opposed-fired boilers generally utilize large bellows, which suffer from a lack of air volume control and inflexible adjustment mechanisms, resulting in uneven air volume distribution across burners. Utility Model Content

[0005] In order to solve the problems of lack of air volume control means and inflexible adjustment mechanism in the secondary air system of the impulsive combustion boiler described in the background art, the present utility model proposes the following technical solutions:

[0006] A regulating device for hedging the secondary air box of a coal-fired boiler, comprising: two main air ducts, two side air ducts, two groups of first diversion components, two groups of second diversion components, a front wall and a rear wall; the input end of each of the main air ducts is connected to the air preheater, and the output end of each of the main air ducts outputs secondary air to the front wall and the rear wall; each of the side air ducts comprises a forward air duct and a rear air duct, the forward air duct connects the main air duct and the front wall, and the rear air duct connects the front wall and the rear wall; each group of the first diversion components is fixedly arranged in the corresponding main air duct to divide the output end of each main air duct into multiple sub-air ducts; each group of the second diversion components is fixedly arranged in the corresponding side air duct to divert the secondary air output by each main air duct; in the cross section of each of the main air ducts, the end face of each group of the first diversion components and the end face of the corresponding second diversion component are perpendicular to each other.

[0007] The front wall comprises a first left guide channel, a first right guide channel (52) and multiple layers of first burners; the vertical portion of the first left guide channel is connected to one side of the first burner on each layer, and the horizontal portion of the first left guide channel is connected to one of the main air ducts and one of the forward air ducts; the vertical portion of the first right guide channel (52) is connected to the other side of the first burner on each layer, and the horizontal portion of the first right guide channel (52) is connected to the other side of the main air duct and the other side of the forward air duct.

[0008] Furthermore, the rear wall includes a second left guide channel, a second right guide channel and multiple layers of second burners; the vertical portion of the second left guide channel is respectively connected to one side of the second burner on each layer, and the horizontal portion of the second left guide channel is connected to one of the rear air ducts; the vertical portion of the second right guide channel is respectively connected to the other side of the second burner on each layer, and the horizontal portion of the second right guide channel is connected to the other one of the rear air ducts.

[0009] Furthermore, each group of the first diversion components includes a first part and a second part; the first part is bent and extended, and the first part is fixed in the inner cavity of one of the main air ducts; the second part and the first part are arranged equidistantly to evenly divide the output end of the main air duct into three sub-air ducts.

[0010] Furthermore, the bending parts of the first part and the second part are both arc-shaped.

[0011] Furthermore, each group of the second diversion components includes a third part and a fourth part; the third part and the fourth part are respectively fixed at the connection between one of the forward air ducts and the main air duct, the third part is bent and extended, and the third part and the fourth part are arranged equidistantly to divide the output end of the forward air duct into a plurality of sub-channels matching the front wall.

[0012] Furthermore, wind shields are provided at both ends of the first burners on each layer and at both ends of the second burners on each layer.

[0013] Furthermore, an air duct resistance regulator is provided in the output end of each of the backward air ducts.

[0014] Furthermore, the arrangement direction of the sub-air ducts of the main air duct in the cross section of the main air duct output end is perpendicular to the arrangement direction of the sub-channels in the forward air duct in the cross section of the forward air duct input end.

[0015] Beneficial effect: The utility model makes the secondary air volume flowing into the front wall and the rear wall of the air preheater equal through the first diversion component set in the main air duct and the second air flow component set in the lateral air duct, thereby avoiding insufficient combustion in the rear wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of a regulating device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model, wherein the first diverter assembly and the second diverter assembly are blocked;

[0017] Figure 2 This is a schematic diagram of the internal structure of a regulating device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model;

[0018] Figure 3 Schematic diagram of the internal structure of a regulating device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model from a top side view;

[0019] Figure 4 This is a side view schematic diagram of the internal structure of a regulating device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the utility model;

[0020] Figure 5 This is a schematic diagram of the internal structure of a first burner or a second burner according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of this application more clear, the present invention will be described in further detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] It should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this patent and simplifying the description, 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 cannot be understood as a limitation on this patent.

[0023] Figure 1 This is a structural schematic diagram of an adjustment device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model, wherein the first diversion component and the second diversion component are blocked.

[0024] Reference Figure 1According to an embodiment of the utility model, a regulating device for hedging the secondary air box of a coal-fired boiler includes: two main air ducts 1, two lateral air ducts 2, two groups of first diversion components 3, two groups of second diversion components 4, a front wall 5 and a rear wall 6. The input end of each main air duct 1 is connected to the air preheater, and the output end of each main air duct 1 outputs secondary air to the front wall 5 and the rear wall 6. Each lateral air duct 2 includes a forward air duct 21 and a rear air duct 22, the forward air duct 21 connects the main air duct 1 and the front wall 5, and the rear air duct 22 connects the front wall 5 and the rear wall 6. Each group of first diversion components 3 is fixedly arranged in the corresponding main air duct 1 to divide the output end of each main air duct 1 into multiple sub-air ducts. Each group of second diversion components 4 is fixedly arranged in the corresponding lateral air duct 2 to divert the secondary air output by each main air duct 1. In the cross section of each main air duct 1 , the end surface of each group of first flow diverter components 3 and the end surface of the corresponding second flow diverter component 4 are perpendicular to each other.

[0025] Figure 2 This is a schematic diagram of the internal structure of a main view of an adjustment device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model.

[0026] Refer to Figure 1 and Figure 2 Specifically, the front wall 5 includes: a first left guide channel 51, a first right guide channel 52, and a multi-layer first burner 53. The first left guide channel 51 is generally cross-shaped, and is provided with a vertical cavity and a horizontal cavity interconnected therein (i.e., the vertical portion and the horizontal portion of the first left guide channel 51). The first right guide channel 52 is generally cross-shaped, and is provided with a vertical cavity and a horizontal cavity interconnected therein (i.e., the vertical portion and the horizontal portion of the first right guide channel 52).

[0027] The vertical cavity of the first left guide channel 51 is connected to one side of each layer of the first burner 53, and the other end of each layer of the first burner 53 is connected to one side of the vertical cavity of the first right guide channel 52. The horizontal cavity of the first left guide channel 51 is connected to one of the forward air ducts 21 and one of the backward air ducts 22, respectively. The horizontal cavity of the first right guide channel 52 is connected to the other side of the forward air duct 21 and the other side of the backward air duct 22.

[0028] Figure 3 The figure is a schematic diagram of the internal structure of a regulating device for hedging a secondary air box of a coal-fired boiler from a top side view according to an embodiment of the present utility model.

[0029] Refer to Figure 1 and Figure 3Furthermore, the structures of the front wall 5 and the rear wall 6 are similar. Specifically, the rear wall 6 includes: a second left guide channel 61, a second right guide channel 62, and multiple layers of second burners 63. The second left guide channel 61 is cross-shaped as a whole, and is provided with a vertical cavity and a horizontal cavity that are interconnected (i.e., the vertical portion and the horizontal portion of the second left guide channel 61). The second right guide channel 62 is cross-shaped as a whole, and is provided with a vertical cavity and a horizontal cavity that are interconnected (i.e., the vertical portion and the horizontal portion of the second right guide channel 62). The vertical cavity of the second left guide channel 61 is respectively connected to one side of each layer of the second burner 63, and the other end of each layer of the second burner 63 is respectively connected to one side of the vertical cavity of the second right guide channel 62. The horizontal cavity of the second left guide channel 61 is connected to one of the rearward air ducts 22, and the horizontal cavity of the second right guide channel 62 is connected to the other of the rearward air ducts 22.

[0030] Continue to refer to Figure 2 , further, each group of first diversion components 3 includes a first part 31 and a second part 32, and each group of second diversion components 4 includes a third part 41 and a fourth part 42. The first part 31 and the second part 32 are respectively fixed in the cavity of one of the main air ducts 1, and the first part 31 and the second part 32 are arranged at intervals, and the first part 31 and the second part 32 are equidistant. The first part 31 bends and extends along the main air duct 1, and the bent part of the first part 31 is an arc. The second part 32 is fixed between the first part 31 and the inner wall of the main air duct 1, and the bent part of the second part 32 is an arc with the same diameter as the first part 31. Under the action of the first part 31 and the second part 32, the output end of each main air duct 1 is equally divided into three sub-air ducts, and the secondary air flowing in from the air preheater is divided into three equal flows of secondary air after being output from the main air duct 1 and input into the forward air duct 21.

[0031] Continue to refer to Figure 3 Specifically, each group of second diversion components 4 includes: a third part 41 and a fourth part 42. The third part 41 and the fourth part 42 are respectively fixed at the connection between one of the forward air ducts 21 and one of the main air ducts 1. The third part 41 and the fourth part 42 are arranged at intervals, and the third part 41 bends and extends along the forward air duct 21. The third part 41 and the fourth part 42 are equidistant, and the bend of the third part 41 and the bend of the fourth part 42 are both arc-shaped, and the arcs of the third part 41 and the fourth part 42 have the same diameter. Under the action of the third part 41 and the fourth part 42, the secondary air input from the main air duct 1 to the forward air duct 21 is further diverted, thereby ensuring that the secondary air flowing into each first burner 53 is equal. Furthermore, on the cross section of the output end of the main air duct 1, the sub-air ducts of the main air duct 1 are arranged in a direction from top to bottom, and on the cross section of the input end of the forward air duct 21, the sub-channels of the forward air duct 21 are arranged in a direction from left to right.

[0032] Figure 4 The figure is a side view schematic diagram of the internal structure of an adjusting device for hedging a secondary air box of a coal-fired boiler according to an embodiment of the present utility model.

[0033] Reference Figure 4 Furthermore, in order to prevent the difference in the amount of secondary air flowing between the front wall 5 and the rear wall 6 from being too large, an air duct resistance regulator 8 is provided in the second left guide channel 61 and the second right guide channel 62, respectively. The secondary air output from the lateral air duct 2 adjusts the secondary air entering the rear wall 6 due to the blocking effect of the air duct resistance regulator 8, thereby reducing the air volume difference between the front wall 5 and the rear wall 6. The air duct resistance regulator 8 can adjust the size of the longitudinal cross-sectional area of ​​the rear air duct 22 according to the different loads of the unit through structures such as electric baffles, so as to achieve the effect of regulating the air volume entering the rear wall 6. The air duct resistance regulator 8 is already a mature product at present, and its structure will not be described in detail here.

[0034] Figure 5 This is a schematic diagram of the internal structure of a first burner or a second burner according to an embodiment of the present utility model.

[0035] Reference Figure 5 Preferably, in this embodiment, each first burner 53 and each second burner 63 is provided with a windshield 7 at both ends. Each windshield 7 is U-shaped as a whole, which can block and reflux the secondary air. When each first burner 53 and each second burner 63 receives the secondary air output from the lateral air duct 2, the windshield 7 refluxes part of the secondary air to the lateral channel, and partially flows into the middle of the corresponding first burner 53 or second burner 63, thereby solving the problem of low flow at the ends of the first burner 53 and the second burner 63 and high flow in the middle.

[0036] In summary, the present invention utilizes a first flow divider assembly within the main air duct and a second flow assembly within the lateral air duct to ensure that the amount of secondary air flowing from the air preheater into the front and rear walls is equal, thus preventing incomplete combustion within the rear wall. Furthermore, the provision of windshields evenly distributes the secondary air flow to each first burner and each second burner, preventing the problem of excessively high flow in the center and low flow on either side.

[0037] While the foregoing description describes certain embodiments of the invention, other embodiments are within the scope of the following claims.

[0038] Throughout this specification, the terms "exemplary," "example," and the like are used to mean "serving as an example, instance, or illustration" and do not imply "preferred" or "advantageous" over other embodiments. The detailed description includes specific details for the purpose of providing an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0039] The above describes in detail the optional implementation methods of the embodiments of the present invention in conjunction with the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details of the above implementation methods. Within the technical concept of the embodiments of the present invention, the technical solutions of the embodiments of the present invention can be modified in a variety of simple ways, and these simple modifications all fall within the scope of protection of the embodiments of the present invention.

[0040] The foregoing description of this specification is provided to enable any person skilled in the art to implement or use the present disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is intended to be consistent with the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A regulating device for hedging the secondary air box of a coal-fired boiler, characterized in that: include: Two main air ducts (1), two lateral air ducts (2), two groups of first flow diversion components (3), two groups of second flow diversion components (4), a front wall (5) and a rear wall (6); the input end of each main air duct (1) is connected to an air preheater, and the output end of each main air duct (1) outputs secondary air to the front wall (5) and the rear wall (6); each lateral air duct (2) includes a forward air duct (21) and a rear air duct (22), the forward air duct (21) is connected to the main air duct (1) and the front wall (5), and the rear air duct (22) is connected to the front wall (5). 2) connecting the front wall (5) and the rear wall (6); each group of the first diversion components (3) is fixedly arranged in the corresponding main air duct (1) to divide the output end of each main air duct (1) into multiple sub-air ducts; each group of the second diversion components (4) is fixedly arranged in the corresponding lateral air duct (2) to divert the secondary air output from each main air duct (1); on the cross section of each main air duct (1), the end face of each group of the first diversion components (3) and the end face of the corresponding second diversion components (4) are perpendicular to each other.

2. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 1, characterized in that: The front wall (5) includes a first left guide channel (51), a first right guide channel (52) and multiple layers of first burners (53); the vertical portion of the first left guide channel (51) is connected to one side of the first burner (53) on each layer, and the horizontal portion of the first left guide channel (51) is connected to one of the main air ducts (1) and one of the forward air ducts (21); the vertical portion of the first right guide channel (52) is connected to the other side of the first burner (53) on each layer, and the horizontal portion of the first right guide channel (52) is connected to the other side of the main air duct (1) and the other side of the forward air duct (21).

3. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 2, characterized in that: The rear wall (6) includes a second left guide channel (61), a second right guide channel (62) and multiple layers of second burners (63); the vertical portion of the second left guide channel (61) is respectively connected to one side of the second burner (63) of each layer, and the horizontal portion of the second left guide channel (61) is connected to one of the rear air ducts (22); the vertical portion of the second right guide channel (62) is respectively connected to the other side of the second burner (63) of each layer, and the horizontal portion of the second right guide channel (62) is connected to the other side of the rear air duct (22).

4. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 3, characterized in that: Each group of the first flow diversion components (3) comprises a first part (31) and a second part (32); the first part (31) is bent and extended, and the first part (31) is fixed in the inner cavity of one of the main air ducts (1); the second part (32) and the first part (31) are arranged at equal distances to evenly divide the output end of the main air duct (1) into three sub-air ducts.

5. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 4, characterized in that: The bending parts of the first part (31) and the second part (32) are both arc-shaped.

6. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 5, characterized in that: Each group of the second flow diversion components (4) includes a third part (41) and a fourth part (42); the third part (41) and the fourth part (42) are respectively fixedly arranged at the connection between one of the forward air ducts (21) and the main air duct (1), the third part (41) is bent and extended, and the third part (41) and the fourth part (42) are arranged at equal distances to divide the output end of the forward air duct (21) into a plurality of sub-channels matching the front wall (5).

7. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 4, characterized in that: Wind shields (7) are respectively provided at both ends of the first burner (53) of each layer and at both ends of the second burner (63) of each layer.

8. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 4, characterized in that: An air duct resistance regulator (8) is provided in the output end of each of the backward air ducts (22).

9. The regulating device for hedging the secondary air box of a coal-fired boiler according to claim 4, characterized in that: The arrangement direction of the sub-air ducts of the main air duct (1) in the cross section of the output end of the main air duct (1) is perpendicular to the arrangement direction of the sub-channels in the forward air duct (21) in the cross section of the input end of the forward air duct (21).

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