Flue gas side flow adjusting device of air preheater

Abstract

The invention discloses a flue gas side flow adjusting device of an air preheater, and belongs to the technical field of flow adjusting devices of air preheaters. Two partition wall plates are symmetrically arranged, one ends of the two partition wall plates are fixedly connected with the inner side of an air preheater shell plate, the other ends of the two partition wall plates are fixedly connected with the inner side of a front connecting plate, a support is fixed to the outer side of the air preheater shell plate, and a motor and a gearbox are fixed to the support. The output end of the motor is connected with the input end of the gearbox, the two ends of an output shaft of the gearbox are each provided with a driving chain wheel, two driven chain wheels are installed on the outer side face of the front connecting plate, and the two driving chain wheels and the two driven chain wheels are in transmission connection through two chains. A fixed wind shield is fixed between the two partition wall plates close to the inner side of the air preheater shell plate, a plurality of movable wind shields are sequentially distributed between the two partition wall plates, and wind shield rails are arranged on the two partition wall plates. The problem that the air preheater is prone to dust accumulation is solved.

Description

Technical Field

[0001] The invention relates to a flue gas side flow regulating device for an air preheater, belonging to the technical field of flow regulating devices for air preheaters. Background Art

[0002] The boiler air preheater of the generator set is designed and manufactured according to the full load of the boiler, that is, it is designed according to the maximum flue gas and air flow that the air preheater can pass. Now, according to the needs of the electricity market, the power generation of thermal power plants needs to be controlled, which is now called "peak shaving". In detail, peak shaving means that a 1000MW unit cannot always run at 1000MW. It can be 1000MW or 300MW. Now the peak shaving is required to reach 20%, that is, the minimum power generation is 200MW. Peak shaving has an impact on the boiler air preheater. The most obvious is the ash blockage of the air preheater. Of course, there are other reasons for the ash blockage, but the main reason is caused by peak shaving.

[0003] When the boiler load is reduced, that is, the total amount of flue gas generated by boiler combustion and the amount of air required for boiler combustion are reduced, but the air preheater flow area is fixed, so the flow rate of flue gas through the air preheater is reduced. The air preheater is designed according to the maximum flue gas and air flow that the air preheater can pass. The average flue gas flow rate is 12m / s, and the air flow rate is 18m / s~20m / s. When the flue gas volume decreases by 40%, the flue gas flow rate drops from 12m / s to 4.8m / s, and the air flow rate is also decreasing. There is ash in the flue gas. When the flue gas flow rate decreases, the ash is easily deposited on the heat exchange elements in the air preheater. It is a consensus that ash is not easy to accumulate when the flow rate is fast.

[0004] How to solve the problem that the boiler air preheater is prone to dust accumulation due to peak load regulation is a problem that technicians in this field need to solve. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned prior art and further provide a flow regulating device on the flue gas side of an air preheater.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A flow regulating device for the flue gas side of an air preheater comprises: an air preheater, and also comprises a plurality of flow regulating units, each of which has a trapezoidal plane, and the plurality of flow regulating units are arranged on the flue gas side of the air preheater; each flow regulating unit comprises a motor, a gearbox, two active sprockets, two passive sprockets, two chains, a fixed windshield, a plurality of movable windshields, a windshield track, a lower track, bolts, a push-pull plate, an extended push plate, a retracted pull plate, two bulkhead plates, wheels, a front connecting plate, a bracket, an upper track and a block; the two bulkhead plates are symmetrically arranged, one end of the two bulkhead plates is fixedly connected to the inner side of the air preheater shell plate, the other end of the two bulkhead plates is fixedly connected to the inner side of the front connecting plate, the bracket is fixed to the outer side of the air preheater shell plate, the motor and the gearbox are fixed to the bracket, the output end of the motor is connected to the input end of the gearbox, a driving sprocket is respectively installed at both ends of the output shaft of the gearbox, two passive sprockets are installed on the outer side of the front connecting plate, and the two active sprockets and the two passive sprockets are connected. They are connected by two chains respectively. A fixed windshield is fixed between the two bulkhead plates close to the inner side of the air preheater shell plate. Several movable windshields are distributed in sequence between the two bulkhead plates. Step-shaped windshield tracks are fixed on the two bulkhead plates. A stopper is fixed at the front end of each windshield track. The two chains are fixedly connected to the frontmost movable windshield by bolts. Except for the frontmost movable windshield, the front ends of the other movable windshields are fixed with push-pull plates. Except for the last movable windshield, the other movable windshields are fixed with push-pull plates. An extended push plate is fixed to the rear end of the wind shield, a retracted pull plate is fixed to the front end of the front movable wind shield, four wheels are installed at the bottom of each movable wind shield, and except for the last movable wind shield, two upper tracks are installed at the top of each movable wind shield, and the wheels and upper tracks between two adjacent movable wind shields up and down (or front and back) are in a rolling connection, two lower tracks are symmetrically fixed between the air preheater shell plate and the front connecting plate, and the wheels under the front movable wind shield are only rollingly connected to the lower tracks.

[0008] The movable wind shield of the present invention moves forward or backward along the center direction of the air preheater driven by the chain to adjust the flow of the air preheater, that is, the area through which the smoke passes through the air preheater can be increased or decreased, so that the time (flow rate) for the smoke to pass through the heat transfer element remains unchanged, ensuring that the air preheater can operate within the range of different load smoke volumes and solving the problem of easy dust accumulation in the air preheater due to peak load regulation of the boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the overall structure of the flue gas side flow regulating device of the air preheater of the present invention.

[0010] Figure 2This is a schematic diagram of the main structure of a unit of the air preheater flue gas side flow regulating device of the present invention.

[0011] Figure 3 for Figure 2 A-direction view.

[0012] Figure 4 for Figure 2 Enlarged view of point B.

[0013] Figure 5 Schematic diagram of the position of the wind deflector track and the stopper.

[0014] Figure 6 A top view of the movable wind deflector.

[0015] Figure 7 This is a bottom view of the movable wind deflector.

[0016] Figure 8 for Figure 6 C-direction view.

[0017] Fig. 9 A schematic diagram of the chain structure.

[0018] Fig.10 This is a schematic diagram of the working principle of the flow control device on the flue gas side of the air preheater.

[0019] The reference numerals in the figure are: 1 for the motor, 2 for the gearbox, 3 for the driving sprocket, 4 for the driven sprocket, 5 for the chain (lock chain), 6 for the shell plate of the air preheater (of the air preheater 11), 7 for the fixed wind shield, 8 for the movable wind shield, 9 for the wind shield track, 10 for the lower track, 11 for the air preheater, 12 for the air side of the air preheater, 13 for the flue gas side of the air preheater, 14 for the heat transfer element, 15 for the bolt, 16 for the push-pull plate, 17 for the extended push plate, 18 for the retracted pull plate, 19 for the partition wall, 20 for the wheel, 21 for the front connecting plate, 22 for the bracket, 23 for the upper track, 24 for the block, Q for the frontmost movable wind shield, and H for the rearmost movable wind shield. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method is given, but the protection scope of the present invention is not limited to the following embodiments.

[0021] like Figures 1 to 10As shown, a flue gas flow regulating device for an air preheater of the present embodiment is composed of an air preheater 11 and a plurality of flow regulating units, each of which has a trapezoidal plane, and the plurality of flow regulating units are arranged on the flue gas side of the air preheater 11; each flow regulating unit is composed of a motor 1, a gearbox 2, two active sprockets 3, two passive sprockets 4, two chains 5, a fixed windshield 7, a plurality of movable windshields 8, a windshield track 9, a lower track 10, bolts 15, a push-pull plate 16, an extended push plate 17, a retracted pull plate 18, two bulkhead plates 19, wheels 20, and a front connecting plate 2 1, a bracket 22, an upper track 23 and a stopper 24; the two bulkhead plates 19 are symmetrically arranged, one end of the two bulkhead plates 19 is fixedly connected to the inner side of the air preheater shell plate 6, and the other end of the two bulkhead plates 19 is fixedly connected to the inner side of the front connecting plate 21, the bracket 22 is fixed to the outer side of the air preheater shell plate 6, the motor 1 and the gearbox 2 are fixed to the bracket 22, the output end of the motor 1 is connected to the input end of the gearbox 2, and a driving sprocket 3 is installed at both ends of the output shaft of the gearbox 2, and two passive sprockets 4 are installed on the outer side of the front connecting plate 21. The two driving sprockets 3 and the two The passive sprockets 4 are connected by two chains 5 respectively. A fixed windshield 7 is fixed between the two bulkhead plates 19 close to the inner side of the air preheater shell plate 6. A plurality of movable windshields 8 are sequentially distributed between the two bulkhead plates 19. Stepped windshield rails 9 are fixed on the two bulkhead plates 19. A stopper 24 is fixed at the front end of each windshield rail 9. The two chains 5 are fixedly connected to the frontmost movable windshield 8 by bolts 15. Except for the frontmost movable windshield 8, the front ends of the other movable windshields 8 are fixed with push-pull plates 16. Except for the rearmost movable windshield 8, the other movable windshields 8 are fixed with push-pull plates 16. An extended push plate 17 is fixed to the rear end of the movable wind shield 8, a retracted pull plate 18 is fixed to the front end of the front movable wind shield 8, four wheels 20 are installed at the lower part of each movable wind shield 8, and except for the rearmost movable wind shield 8, two upper tracks 23 are installed at the upper part of each movable wind shield 8. The wheels 20 and the upper tracks 23 between two adjacent movable wind shields 8 above and below (or front and back) are in a rolling connection relationship, and two lower tracks 10 are symmetrically fixed between the air preheater shell plate 6 and the front connecting plate 21, and the wheels 20 under the frontmost movable wind shield 8 are only rollingly connected to the lower tracks 10.

[0022] Working process:

[0023] Normally, when the boiler has no peak-shaving task (i.e., the boiler is running at full load), all the movable wind shields 8 are hidden under the fixed wind shield 7 close to the inner side of the air preheater shell plate 6, and the bottommost movable wind shield 8 (i.e., the frontmost movable wind shield 8, also marked as Q) bears the weight of all the movable wind shields 8.

[0024] When the boiler needs to be peak-loaded, the motor 1 is powered (forward rotation), and the two chains 5 drive the frontmost movable windshield 8 to move forward (toward the center of the air preheater), and the topmost movable windshield 8 (i.e., the last movable windshield 8, also marked as H) also moves forward, and the left and right sides of the movable windshield 8 immediately slide into the corresponding windshield tracks 9 on both sides. When the front end of the movable windshield 8 hits the block 24, it stops moving forward, and then the next movable windshield 8 slides into the corresponding windshield tracks 9 on both sides, and so on, until the frontmost movable windshield 8 moves to the peak-loaded setting position, at which time the cross-sectional area of ​​the flue gas side of the air preheater is reduced, which plays a role in regulating the flow of the air preheater. When the flue gas comes, the windshield tracks 9 on both sides are responsible for lifting the movable windshield 8.

[0025] When the boiler exits the peak load regulation, the motor 1 is powered (reverse), and the two chains 5 drive the frontmost movable windshield 8 to retreat (towards the opposite direction of the center of the air preheater circle), and the retracted pull plate 18 on the frontmost (first) movable windshield 8 retreats and hits the lower part of the push-pull plate 16 at the front end of the upper (second) movable windshield 8, driving this (second) movable windshield 8 to retreat together, and at this time, the wheel 20 of the upper movable windshield 8 is rollingly connected with the upper track 23 of the lower movable windshield 8. And so on, until all the movable windshields 8 are hidden under the fixed windshield 7 close to the inner side of the air preheater shell plate 6.

[0026] If there are changes in the boiler peak load, you can refer to the above steps.

[0027] Two adjacent flow regulating units share a partition plate 19 .

[0028] The number of the movable wind shielding plates 8 is 4 to 10.

[0029] The fixing or fixed connection described in the above embodiments are all welding or bolt connections.

[0030] The flow regulating device on the air side of the air preheater may refer to the flow regulating device on the flue gas side of the above embodiment.

[0031] The above are only preferred specific embodiments of the present invention, which are all different implementations based on the overall concept of the present invention, and the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A flue gas flow regulating device for an air preheater, comprising an air preheater (11), characterized in that: It also includes a plurality of flow regulating units, each of which has a trapezoidal plane, and the plurality of flow regulating units are arranged on the flue gas side of the air preheater (11); each flow regulating unit includes a motor (1), a gearbox (2), two active sprockets (3), two passive sprockets (4), two chains (5), a fixed windshield (7), a plurality of movable windshields (8), a windshield track (9), a lower track (10), bolts (15), a push-pull plate (16), an extended push plate (17), a retracted pull plate (18), two bulkhead plates (19), wheels (20), a front connecting plate (21), a bracket (22), an upper track (23) and a stopper (24); The two bulkhead plates (19) are symmetrically arranged, one end of the two bulkhead plates (19) is fixedly connected to the inner side of the air preheater shell plate (6), and the other end of the two bulkhead plates (19) is fixedly connected to the inner side of the front connecting plate (21). The bracket (22) is fixed to the outer side of the air preheater shell plate (6). The motor (1) and the gearbox (2) are fixed to the bracket (22). The output end of the motor (1) is connected to the input end of the gearbox (2). A driving sprocket (3) is respectively installed at both ends of the output shaft of the gearbox (2). Two passive sprockets (4) are installed on the outer side of the front connecting plate (21). Two driving sprockets (3) and two passive sprockets (4) are respectively connected between the two driving sprockets (3) and the two passive sprockets (4). The air preheater shell (6) is connected to the air preheater shell by a chain (5). A fixed windshield (7) is fixed between two bulkhead plates (19) close to the inner side of the air preheater shell plate (6). A plurality of movable windshields (8) are sequentially distributed between the two bulkhead plates (19). Stepped windshield rails (9) are fixed on the two bulkhead plates (19). A stopper (24) is fixed at the front end of each windshield rail (9). The two chains (5) are fixedly connected to the frontmost movable windshield (8) by bolts (15). Except for the frontmost movable windshield (8), the front ends of the other movable windshields (8) are fixed with push-pull plates (16). Except for the rearmost movable windshield (8), the other movable windshields ( An extended push plate (17) is fixed on the rear end of each movable wind shield (8), a retracted pull plate (18) is fixed on the front end of the front movable wind shield (8), four wheels (20) are installed on the lower part of each movable wind shield (8), and two upper tracks (23) are installed on the upper part of each movable wind shield (8) except the rearmost movable wind shield (8), and the wheels (20) and the upper tracks (23) between the two upper and lower adjacent movable wind shields (8) are in a rolling connection relationship, and two lower tracks (10) are symmetrically fixed between the air preheater shell plate (6) and the front connecting plate (21), and the wheels (20) under the frontmost movable wind shield (8) are only in rolling connection with the lower tracks (10).

2. The air preheater flue gas side flow control device according to claim 1, characterized in that: Two adjacent flow regulating units share a partition wall plate (19).

3. The air preheater flue gas side flow control device according to claim 1, characterized in that: The number of the movable wind shielding plates (8) is 4 to 10.

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