Device for replacing supporting bearing of air preheater of boiler of thermal power plant

Abstract

The utility model relates to the technical field of thermal power plant boiler equipment, in particular to a thermal power plant boiler air preheater supporting bearing replacing device which comprises a tray, the tray is fixedly connected to a hollow shaft and arranged above an upper cover of a bearing box, four jacks are connected between the bottom face of the tray and the top face of a cold end supporting truss bottom plate, and the four jacks are arranged on the tray. The air preheater is stable in structure and convenient to use, the existing structure of the air preheater does not need to be damaged, the problem that hot air leaks out to hurt people does not need to be considered, and the air preheater is high in practicability and high in practicability. Maintenance personnel do not enter the air pre-heater to be in direct contact with harmful smoke of a boiler hearth, limited space operation does not exist, the personal safety problem of the maintenance personnel is solved, meanwhile, safe and stable operation of the boiler is achieved, economic losses caused by replacement of a supporting bearing of the air pre-heater and forced stop of the boiler are avoided, and the air pre-heater air pre-heater supporting device has popularization value.

Description

Technical Field

[0001] The utility model relates to the technical field of boiler equipment in thermal power plants, in particular to a device for replacing supporting bearings of air preheaters of thermal power plant boilers. Background Art

[0002] Boiler air preheater is a flue gas tail end heat exchange device commonly used in thermal power plant boilers in the prior art. This device can use the flue gas heat at the tail end of the boiler to heat the air sent into the boiler furnace, so that the air temperature increases, the boiler exhaust temperature decreases, and the boiler exhaust loss is reduced. At the same time, the air is sent into the boiler after being heated, so that the fuel in the furnace ignites quickly, thereby reducing mechanical and chemical incomplete combustion losses and improving boiler efficiency. In addition, the increase in air temperature can increase the furnace temperature accordingly, which can quickly ignite the fuel, improve or strengthen combustion, and ensure boiler combustion stability under low load.

[0003] For example, the Ljungberg air preheater model of a coal-fired boiler of a 2×320MW unit is 28-VI (T) -SMR, which adopts a three-compartment vertical main axis arrangement, and the flue gas and air exchange heat in a countercurrent manner. Each coal-fired boiler is equipped with two air preheaters.

[0004] In the prior art, when an air preheater support bearing fails and needs to be replaced, maintenance personnel must enter the air preheater to perform related operations related to the replacement of the support bearing after the boiler stops running and the air preheater is completely cooled.

[0005] During this period, maintenance personnel are in direct contact with harmful flue gases in the boiler furnace and work in a confined space, posing a hidden danger to personal safety. At the same time, due to the replacement of the air preheater support bearings, the boiler will be forced to stop operating for a long time, causing huge economic losses to the company.

[0006] The prior art patent application number is 2018209403270 and the patent name is the fully automatic jacking system for online replacement of air preheater support bearings. The patent discloses an online replacement device for air preheater support bearings, including a cold end center truss, a support bearing, an end shaft sealing device, a rotor center tube, a rotating shaft, a cold end static sealing sleeve, an air preheater and an ejection device. The cold end center truss is a sealed cylindrical structure. The cold end center truss includes a front support plate, a top plate, a bottom plate and a rear support plate. The front support plate, the top plate, the rear support plate and the bottom plate are connected end to end in a rectangular hollow structure, which solves the problem that when the cooling bearing of the existing air preheater is damaged, personnel need to enter the equipment to place a jack and shut down the equipment for replacement, which affects the normal production operation and safety factor of the power plant.

[0007] However, the above-mentioned prior art requires cutting the outer box of the air preheater and adding a static sealing sleeve at the cold end to prevent hot air from escaping and injuring people. It is also necessary to set a rectangular hollow structure on the cold end center truss 1. The rectangular hollow structure occupies the already limited operating space around the support bearing, which is not conducive to personnel operation. The above-mentioned prior art has a complex structure, is difficult to set up, and occupies a large operating space. Utility Model Content

[0008] The purpose of the utility model is to provide a device for replacing the supporting bearing of the air preheater of a boiler in a thermal power plant. The device does not need to destroy the air preheater, has a simple arrangement, reserves operating space for personnel, and is safe and stable to use. It not only solves the personal safety problem of maintenance personnel, but also realizes the safe and stable operation of the boiler, avoiding the economic loss caused by the forced shutdown of the boiler due to the replacement of the supporting bearing of the air preheater.

[0009] The air preheater of the prior art is provided with a hollow shaft at the bottom, a bearing is connected to the lower end of the hollow shaft, the lower end of the bearing is connected to the bearing box, a bearing box cover is sleeved on the hollow shaft, the bearing box cover is connected to the top of the bearing box, the bottom end of the bearing box is connected to the bottom plate of the cold end supporting truss, a washer is connected between the bottom plate of the cold end supporting truss and the bearing box, and a lifting ear is provided on the outer wall of the bearing box. The utility model provides a supporting bearing replacement device for a boiler air preheater in a thermal power plant, comprising a tray, the tray is fixedly connected to the hollow shaft, the tray is arranged above the bearing box cover, a jack is connected between the bottom surface of the tray and the top surface of the cold end supporting truss bottom plate, four jacks are provided, the four jacks are evenly distributed on the circumference with the axis of the hollow shaft as the center, and the four jacks are arranged on the bearing box cover and the outer side of the bearing box.

[0010] Furthermore, a supporting column is connected between the bottom surface of the pallet and the top surface of the bottom plate of the cold end supporting truss. There are four supporting columns, which are respectively arranged on the sides of four jacks. The top ends of the supporting columns are connected to the bottom surface of the pallet, and the bottom ends of the supporting columns are connected to the top surface of the bottom plate of the cold end supporting truss.

[0011] Furthermore, the tray is a circular ring with a through hole in the center, the through hole in the center of the tray is welded to the outer wall of the hollow shaft, a vertical rib plate is fixedly connected to the top surface of the tray, the side walls of the vertical rib plate are attached to the outer wall of the hollow shaft, the bottom wall of the vertical rib plate is welded to the top surface of the tray, and a plurality of vertical rib plates are provided, and the plurality of vertical rib plates are evenly distributed around the circumference with the axis of the hollow shaft as the center.

[0012] Furthermore, the number of the plurality of vertical rib plates is greater than or equal to the number of jacks, and the upper ends of the jacks are connected to the bottom surface of the tray below the vertical rib plates.

[0013] Furthermore, the vertical rib plate is a right triangle, and one of the two right-angled sides of the vertical rib plate is fitted on the outer wall of the hollow shaft and the other is welded to the top surface of the tray.

[0014] Furthermore, a symmetrical groove is provided on the surface where the vertical rib plate is welded to the tray, and the height deviation between two adjacent vertical rib plates is ≤0.5 mm.

[0015] Furthermore, the tray comprises two semicircular rings butted together, and a single-sided V-shaped groove is provided on the welding surface of the two semicircular rings, and the single-sided V-shaped groove is directed downward.

[0016] Furthermore, the bottom end of the supporting column is welded to the top surface of the bottom plate of the cold end supporting truss.

[0017] Furthermore, the material of the pallet is Q235A; the material of the rib plate is Q235A; and the material of the supporting column is 15CrMoG.

[0018] The beneficial effects of the utility model are as follows: the utility model has a stable structure and is easy to use. There is no need to destroy the existing structure of the air preheater. Only a tray needs to be welded on the outer wall of the hollow shaft 1. There is no need to consider the problem of hot air escaping and injuring people. It occupies a small space and reserves working space for the loading and unloading of the bearing box. The existing jacking method below the rotor center tube inside the air preheater is moved to the outside of the air preheater. When replacing the supporting bearings, maintenance personnel no longer need to enter the air preheater and directly contact the harmful flue gas in the boiler furnace, and there is no confined space operation. It not only solves the personal safety problem of the maintenance personnel, but also realizes the safe and stable operation of the boiler, and avoids the huge economic benefit loss caused by the forced shutdown of the boiler due to the replacement of the air preheater supporting bearings. The utility model has promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the utility model;

[0020] Figure 2 It is a top view of the tray of the utility model.

[0021] In the figure: 1. hollow shaft; 2. vertical rib plate; 3. tray; 4. jack; 5. supporting column; 6. bearing box upper cover; 7. bearing box; 8. lifting lug; 9. shim; 10. cold end supporting truss bottom plate. DETAILED DESCRIPTION

[0022] like Figure 1-Figure 2As shown, a hollow shaft 1 is provided at the bottom of the air preheater, a bearing is connected to the lower end of the hollow shaft 1, the lower end of the bearing is connected to the bearing box 7, a bearing box cover 6 is sleeved on the hollow shaft 1, the bearing box cover 6 is connected to the top of the bearing box 7, the bottom end of the bearing box 7 is connected to the cold end support truss bottom plate 10, a washer 9 is connected between the cold end support truss bottom plate 10 and the bearing box 7, and a lifting ear 8 is provided on the outer wall of the bearing box 7. The utility model is a thermal power plant boiler air preheater support bearing replacement device includes a tray 3, the tray 3 is fixedly connected to the hollow shaft 1, the tray 3 is arranged above the bearing box cover 6, the tray 3 is a circular ring with a through hole in the center, and the tray 3 is provided with a through hole welding It is connected to the outer wall of the hollow shaft 1, and a vertical rib plate 2 is fixedly connected to the top surface of the pallet 3. The side walls of the vertical rib plate 2 are fitted on the outer wall of the hollow shaft 1, and the bottom wall of the vertical rib plate 2 is welded to the top surface of the pallet 3. There are multiple vertical rib plates 2, and the multiple vertical rib plates 2 are evenly distributed around the circumference of the axis of the hollow shaft 1. A jack 4 is connected between the bottom surface of the pallet 3 and the top surface of the cold end support truss bottom plate 10. There are four jacks 4, and the four jacks 4 are evenly distributed around the circumference of the axis of the hollow shaft 1. The four jacks 4 are all arranged on the outer side of the bearing box cover 6 and the bearing box 7. The number of the multiple vertical rib plates 2 is greater than or equal to the number of jacks 4, and the upper ends of the jacks 4 are connected to the bottom surface of the pallet 3 below the vertical rib plates 2.

[0023] Furthermore, a supporting column 5 is connected between the bottom surface of the pallet 3 and the top surface of the cold end supporting truss bottom plate 10. Four supporting columns 5 are provided, and the four supporting columns 5 are respectively arranged on the sides of the four jacks 4. The top end of the supporting column 5 is connected to the bottom surface of the pallet 3, and the bottom end of the supporting column 5 is connected to the top surface of the cold end supporting truss bottom plate 10.

[0024] The vertical rib plate 2 is a right triangle, and one of the two right-angled sides of the vertical rib plate 2 is attached to the outer wall of the hollow shaft 1 and the other is welded to the top surface of the tray 3. Symmetrical grooves are provided on the surface where the vertical rib plate 2 and the tray 3 are welded, and the height deviation of two adjacent vertical rib plates 2 is ≤0.5mm.

[0025] The tray 3 is composed of two semicircular rings butted together, and a single-sided V-shaped groove is arranged on the butt-welding surface of the two semicircular rings, and the single-sided V-shaped groove is directed downward.

[0026] The bottom end of the supporting column 5 is welded to the top surface of the cold end supporting truss bottom plate 10.

[0027] The material of the tray 3 is Q235A; the material of the rib plate 2 is Q235A; the material of the supporting column 5 is 15CrMoG.

[0028] The tray 3 is welded to the outer wall of the hollow shaft 1. There is no need to cut the hollow shaft 1, and the air preheater structure is not damaged. There is no need to consider the problem of hot air escaping and injuring people. There is no need to set up a sealing structure separately. The vertical rib plate 2 strengthens the strength of the tray 3. The tray 3 is composed of two semicircular rings connected together, which is convenient for setting up and installing. A single-sided V-shaped groove is provided on the welding surface of the two semicircular rings, and the single-sided V-shaped groove is facing downward, so that it can withstand a large upward force and maintain the rigidity of the tray.

[0029] The bottom surface of the rib plate 2 is firmly welded to the tray 3, and welding is not allowed between the rib plate 2 and the fitting surface of the hollow shaft 1, thereby reducing the welding stress of the air preheater hollow shaft and preventing the hollow shaft from deforming.

[0030] The installation of the four jacks 4 may be performed by an inverted installation method, which does not affect the passage for the bearing seat to be moved out and in.

[0031] The material of the supporting column 5 is 15CrMoG steel pipe, which can bear a large vertical load.

[0032] When the utility model is in use, the triangular rib plates are symmetrically and evenly welded on the hollow shaft 1 to ensure that the height deviation of adjacent ribs is no more than 0.5mm. The butt-welded tray 3 is horizontally welded to the bottom of the triangular rib plate 2 and leveled. Four 100-ton screw jacks 4 are invertedly arranged between the tray 3 and the bottom plate 10 of the cold end support truss of the air preheater. At the same time, a scale for observing the jacking height is arranged at the four jacks 4 to achieve an observation basis during synchronous jacking. When the jacking height of the four jacks 4 reaches the rated value, the four supporting columns 5 are supported beside the four jacks, and the lower end points of the supporting columns 5 are welded to the bottom plate 10 of the cold end support truss. Remove the bolts connecting the upper cover 6 and the bearing box 7 to separate the upper cover 6 and the bearing box 7, push the upper cover 6 along the hollow shaft upward to the lower part of the tray 3 and fix it, use the hand chain hoist to pull on the lifting lug 8 of the bearing box, suspend the bearing box 7, remove the shim 9 and other limiting devices, and then drop the bearing box 7 onto the base surface of the cold end support truss bottom plate 10, and remove the fall chain. Pull out the bearing box 7 horizontally through the sliding guide rail or other devices docked on the cold end support truss bottom plate 10 to complete the replacement of the support bearing.

[0033] After the replacement of the supporting bearing is completed, the bearing box 7 is restored in reverse order, the shim 9 is reinstalled, the bearing box 7 is adjusted to the level, the limit device is restored, and the supporting column 5 and the jack 4 are removed.

[0034] The utility model realizes online replacement of the air preheater support bearing, which not only solves the personal safety problem of maintenance personnel, but also avoids the economic benefit loss caused by the boiler being forced to stop running due to the replacement of the air preheater support bearing. The utility model is easy to implement and saves enterprise costs.

Claims

1. A device for replacing bearings of a boiler air preheater in a thermal power plant, wherein a hollow shaft (1) is provided at the bottom of the air preheater, a bearing is connected to the lower end of the hollow shaft (1), the lower end of the bearing is connected to a bearing box (7), a bearing box upper cover (6) is sleeved on the hollow shaft (1), the bearing box upper cover (6) is connected to the top of the bearing box (7), the bottom end of the bearing box (7) is connected to the bottom plate (10) of the cold end support truss, a shim (9) is connected between the bottom plate (10) of the cold end support truss and the bearing box (7), and a lifting lug (8) is provided on the outer wall of the bearing box (7), characterized in that: The hollow shaft (1) is fixedly connected to a tray (3), the tray (3) being arranged above the bearing box upper cover (6), a jack (4) being connected between the bottom surface of the tray (3) and the top surface of the cold end support truss bottom plate (10), four jacks (4) being arranged, the four jacks (4) being evenly distributed around a circle with the axis of the hollow shaft (1) as the center, and the four jacks (4) being arranged on the outer side of the bearing box upper cover (6) and the bearing box (7).

2. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 1, characterized in that: A supporting column (5) is connected between the bottom surface of the tray (3) and the top surface of the cold end support truss bottom plate (10), and four supporting columns (5) are provided. The four supporting columns (5) are respectively arranged on the sides of four jacks (4), and the top ends of the supporting columns (5) are connected to the bottom surface of the tray (3), and the bottom ends of the supporting columns (5) are connected to the top surface of the cold end support truss bottom plate (10).

3. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 2, characterized in that: The tray (3) is a circular ring with a through hole at the center. The through hole at the center of the tray (3) is welded to the outer wall of the hollow shaft (1). A rib plate (2) is fixedly connected to the top surface of the tray (3). The side wall of the rib plate (2) is attached to the outer wall of the hollow shaft (1). The bottom wall of the rib plate (2) is welded to the top surface of the tray (3). A plurality of rib plates (2) are provided. The plurality of rib plates (2) are evenly distributed around a circle with the axis of the hollow shaft (1) as the center.

4. A device for replacing supporting bearings of air preheater of boiler in thermal power plant according to claim 3, characterized in that: The number of the plurality of vertical rib plates (2) is greater than or equal to the number of the jacks (4), and the upper ends of the jacks (4) are connected to the bottom surface of the tray (3) below the vertical rib plates (2).

5. A device for replacing supporting bearings of air preheater of boiler in thermal power plant according to claim 4, characterized in that: The vertical rib plate (2) is a right-angled triangle, and one of the two right-angled sides of the vertical rib plate (2) is fitted on the outer wall of the hollow shaft (1) and the other is welded to the top surface of the tray (3).

6. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 5, characterized in that: Symmetrical grooves are provided on the surface where the rib plate (2) is welded to the tray (3), and the height deviation of two adjacent rib plates (2) is ≤0.5 mm.

7. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 6, characterized in that: The tray (3) comprises two semicircular rings butted together, and a single-sided V-shaped groove is provided on the butt-welding surfaces of the two semicircular rings, with the single-sided V-shaped groove facing downward.

8. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 7, characterized in that: The bottom end of the supporting column (5) is welded to the top surface of the cold end supporting truss bottom plate (10).

9. The device for replacing the supporting bearing of the air preheater of a thermal power plant boiler according to claim 8, characterized in that: The material of the tray (3) is Q235A; the material of the rib plate (2) is Q235A; and the material of the supporting column (5) is 15CrMoG.

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