High-temperature furnace flue pipe with inclined plate type sliding structure

Abstract

The application provides a high-temperature furnace flue pipe with a slope plate type sliding structure, and relates to the technical field of boilers.The flue pipe is connected with a boiler furnace through a sliding structure.The sliding structure comprises two end plates which are parallel to each other and are arranged in a slope manner.A through hole is formed on each of the two end plates to form a channel for conveying medium.The through hole on one end plate is connected with the flue pipe, and the through hole on the other end plate is connected with the boiler furnace.The sliding structure with the slope plate type end plates can greatly improve the thrust required to be borne by the sliding structure, greatly improve the stress condition of the contact part of the sliding structure, and promote smooth sliding of the sliding structure.Meanwhile, the sliding structure can reduce or eliminate the deformation and displacement of the flue pipe caused by the thrust, thereby maintaining and enhancing the overall stability of the flue pipe, prolonging the service life of the pulverizing system, and ensuring the safety, economy and stability of the boiler operation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of boiler, and particularly relates to a high-temperature furnace flue pipe with inclined plate type sliding structure. BACKGROUND

[0002] The boiler burning lignite usually adopts a pulverizing system of fan mill + furnace flue type, wherein the furnace flue is huge in volume, with a diameter of 2 to 4 meters, and is used as a conveying passage of lignite drying medium, extending from the furnace extraction port to the inlet of the fan mill, with a long pipeline along the path and a relatively tortuous path. Since there is a considerable thermal expansion difference between the furnace flue and the boiler body, an important device for absorbing the expansion difference, i.e. a sliding structure device, is arranged at the interface between the two, i.e. the furnace flue extraction port. The sliding structure is applied in many boiler projects at home and abroad, but there is a common problem of poor sliding during operation. Part of the reason is caused by poor installation quality, and part of the reason is caused by the structure problem of the sliding structure itself.

[0003] A typical sliding structure is composed of two mutually parallel end plates, and the two end plates are vertically placed and perpendicular to the horizontal plane. The two end plates do not directly contact each other to minimize the contact area and friction force therebetween, but a maximum and minimum limiting device is used to control the gap between the two plates. The gap edge is sealed by a high-temperature-resistant composite material to achieve a certain sealing property. The vertical expansion amount Z in the three-dimensional expansion difference is absorbed by the relative sliding between the two end plates of the sliding structure. There are two components in the horizontal direction, one is the component X perpendicular to the water-cooled wall pipe wall, and the other is the component Y parallel to the water-cooled wall pipe wall. Y can be absorbed in the form of a clamping plate slot, and X is solved by pushing the furnace flue outward by the boiler body during operation. When the typical vertical sliding structure absorbs the expansion in the X direction, the boiler body needs to push the huge and heavy furnace flue a certain distance in the outward direction of the furnace by the thermal expansion force, so there is a large pushing force between the two. The pushing force is transmitted by the specific components inside the sliding structure. Due to the huge pushing force, the stress inside the sliding structure is huge, there is a huge pressure and friction force in the slidable components, and the structural parts have a certain deformation, thereby causing poor sliding during operation. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a high-temperature furnace flue pipe with inclined plate type sliding structure, which can maintain or enhance the operation stability of the lignite-fired boiler and prolong the service life of the pulverizing system, to solve the problems in the background art.

[0005] To achieve the above object, the application provides a high-temperature furnace flue pipe with a sliding structure of inclined plate, wherein the flue pipe is connected with a boiler furnace through the sliding structure, and the sliding structure comprises two end plates which are parallel to each other and are arranged obliquely, a through hole is formed on each of the two end plates to form a channel for conveying medium, the through hole on one end plate is connected with the flue pipe, and the through hole on the other end plate is connected with the boiler furnace.

[0006] The through holes on the two end plates are communicated to form a conveying channel for lignite drying medium (usually flue gas or hot air).

[0007] Further, the through hole on one end plate is welded and fixed with the end of the flue pipe, and the other end plate is fastened on a rigid beam on one side of the boiler furnace by means of bolts or pins.

[0008] Further, the two end plates are a first end plate and a second end plate, respectively, the size of the first end plate is smaller than that of the second end plate for the purpose of sealing, the through hole on the first end plate is connected with the flue pipe, the through hole on the second end plate is connected with the boiler furnace, a gap is left between the first end plate and the second end plate, the mutual sliding between the two expansion bodies (the boiler furnace and the flue pipe) is realized through the two end plates, and the edge of the first end plate is sealed by a high-temperature-resistant plug.

[0009] The first end plate and the second end plate are both planar plates, the gap between the two end plates is controlled within a designed range by means of a limiting device, so as to reduce the contact area between the two end plates, and further reduce the friction and transfer the acting force between the two end plates.

[0010] The two end plates slide relatively in parallel during the operation of the boiler, but the first end plate does not exceed the edge of the second end plate at all times through the structural design; the high-temperature-resistant plug arranged at the edge of the first end plate is used for sealing the gap between the two end plates and plays a sealing role.

[0011] Further, the included angle between the end plate and the vertical direction is α, the arctangent value of the ratio of the horizontal expansion amount to the vertical expansion amount required to be absorbed by the sliding structure during the operation of the boiler is β, and the difference between α and β is within ±5°.

[0012] The relationship between α and β is β = arctan (the horizontal expansion amount required to be absorbed by the sliding structure / the vertical expansion amount required to be absorbed by the sliding structure), and |α-β|≤5°.

[0013] By setting the two parallel end plates originally arranged vertically to be arranged obliquely, and the value of the oblique angle of the end plates being determined according to the ratio of the vertical expansion amount to the horizontal expansion amount required to be absorbed by the sliding structure, the oblique plate type sliding structure can simultaneously absorb the vertical expansion amount Z and the component X in the horizontal direction perpendicular to the water cooling wall pipe wall. The traditional structure does not have the function of absorbing the component X in the horizontal direction perpendicular to the water cooling wall pipe wall. Therefore, the component X no longer needs to be absorbed by pushing the flue gas pipeline outward by the boiler body. Thus, the required thrust borne by the sliding structure can be greatly improved, and the stress condition of the contact part of the sliding structure is greatly improved, thereby facilitating smooth sliding of the sliding structure.

[0014] Further, the gap plug is a high-temperature-resistant inorganic fiber rope.

[0015] Beneficial effects:

[0016] The high-temperature flue gas pipeline provided by the application is configured with an oblique plate type sliding structure, and is usually applied in a lignite-fired boiler system. The flue gas pipeline is connected with the boiler furnace through the sliding structure. The sliding structure comprises two end plates arranged in parallel and obliquely. A through hole is formed on each of the two end plates to form a channel for conveying lignite drying medium. The through hole on one end plate is connected with the flue gas pipeline, and the through hole on the other end plate is connected with the boiler furnace. The edge of one end plate is sealed with a high-temperature-resistant gap plug from the other end plate. The oblique angle of the end plates is determined according to the ratio of the horizontal expansion amount to the vertical expansion amount required to be absorbed by the sliding structure. The sliding structure arranged obliquely absorbs the comprehensive thermal expansion caused during the operation of the boiler, thereby reducing or eliminating the thrust transmitted from the boiler furnace to the flue gas pipeline during the operation, greatly improving the stress condition of the contact part of the sliding structure, and facilitating smooth sliding of the sliding structure. Meanwhile, the deformation and displacement of the flue gas pipeline caused by the thrust can be reduced or eliminated, thereby maintaining and enhancing the overall stability of the flue gas pipeline, prolonging the service life of the pulverizing system, and providing protection for the safety, economy and stability of the boiler operation.

[0017] The concept, specific structure and technical effects of the application will be further described below with reference to the accompanying drawings, so as to fully understand the purpose, features and effects of the application. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The high-temperature flue gas pipeline structure provided by the application is configured with an oblique plate type sliding structure.

[0019] Figure 2 The schematic diagram of the comprehensive expansion direction in the embodiment is shown.

[0020] The reference signs are as follows:

[0021] 1. Sliding structure; 2. End plate; 3. Furnace flue; 4. Seam plug; 5. Furnace flue outlet. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0023] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. The dimensions and thicknesses of each component shown in the drawings are arbitrary, and the present invention does not limit the dimensions and thicknesses of each component. To make the illustrations clearer, the thickness of some components has been appropriately exaggerated in the drawings.

[0024] Embodiments:

[0025] like Figures 1-2 As shown, in a preferred embodiment, a high-temperature flue gas duct with an inclined sliding structure is provided. The flue gas duct 3 is connected to the boiler furnace through the sliding structure 1. The sliding structure 1 is located at the flue gas outlet 5. The sliding structure 1 includes two parallel and inclined end plates 2. Each end plate 2 has a through hole to form a channel for conveying lignite drying medium. The through hole on one end plate 2 is welded and fixed to the end of the flue gas duct 3. The other end plate 2 is fastened to a rigid beam on one side of the boiler furnace with bolts or pins.

[0026] By using an inclined sliding structure, the overall thermal expansion caused by boiler operation is absorbed, thereby reducing or eliminating the thrust transmitted from the boiler furnace to the flue gas duct during operation. This greatly improves the stress condition at the contact points of the sliding structure, thus promoting smooth sliding of the sliding structure.

[0027] The two end plates 2 are the first end plate and the second end plate, respectively. To facilitate sealing, the size of the first end plate is smaller than that of the second end plate. The through hole on the first end plate is connected to the flue gas pipe 3, and the through hole on the second end plate is connected to the boiler furnace. A limiting device is used between the first end plate and the second end plate to leave a gap between them. The two end plates 2 enable mutual sliding between the boiler furnace and the flue gas pipe 3. The edge of the first end plate and the second end plate are sealed by a slit plug 4. The slit plug 4 is made of high-temperature resistant inorganic fiber rope.

[0028] Define the angle between end plate 2 and the vertical direction as α, such as Figure 2As shown, the difference between a and β is within the range of ±5°, and when the difference between a and β is controlled within the range of ±5°, the sliding structure 1 can maximize the improvement of the thrust required to be borne inside the sliding structure 1.

[0029] The overall arrangement of the lignite boiler is divided into two arrangement forms of tower type and π type. The boiler flue pipe of the tower type is a whole one-section type, that is, no expansion joint compensator is arranged in the middle.

[0030] When the boiler flue pipe is a whole one-section type, the furnace extraction port usually adopts a sliding structure. In a typical sliding structure, two end plates are in a vertical state, the thrust of the furnace expansion is transmitted to the boiler flue pipe by the minimum gap limiting device of the sliding structure, and then the whole boiler flue pipe is inclined outward, and there is a large pressure transmission between the two end plates in this process. This is an important reason for the poor sliding.

[0031] The present patent improves this structure to a inclined plate type sliding structure, and the two end plates are arranged in an inclined manner, and the inclined direction is consistent with the expansion direction of the furnace extraction port as much as possible. In this way, the pressure between the two end plates can be greatly reduced, which greatly guarantees the smooth sliding. The ideal state is that the inclination angle of the sliding device is consistent with the expansion direction of the boiler flue pipe system, but in reality, it is difficult to achieve the ideal state due to manufacturing errors, installation errors and other reasons. Therefore, the inclination angle is controlled within ±5° of the expansion direction. Because if the angle deviation exceeds this angle, the two end plates of the inclined plate type sliding structure will be extruded or excessively far away, which will cause the problems of force transmission or too large sealing gap between each other, and the advantages of the inclined plate type sliding structure are lost.

Claims

1. A high temperature furnace flue duct configured with a tilting plate sliding structure, characterized by, The flue gas pipeline (3) is connected with the boiler furnace through the sliding structure (1), the sliding structure (1) comprises two end plates (2) which are parallel to each other and are arranged obliquely, a through hole is formed on each of the two end plates (2) to form a channel for conveying medium, the through hole on one end plate (2) is connected with the flue gas pipeline (3), and the through hole on the other end plate (2) is connected with the boiler furnace; The two end plates (2) are respectively a first end plate and a second end plate, the size of the first end plate is smaller than that of the second end plate, the through hole on the first end plate is connected with the flue gas pipeline (3), the through hole on the second end plate is connected with the boiler furnace, a gap is left between the first end plate and the second end plate, and the edge of the first end plate is sealed from the second end plate through the joint plug (4); The included angle between the end plate (2) and the vertical direction is α, the inverse tangent value of the ratio of the horizontal expansion amount to the vertical expansion amount required by the sliding structure (1) to absorb during the operation of the boiler is β, and the difference between α and β is within ±5°.

2. The high temperature furnace flue duct configured with a tilting plate type sliding structure according to claim 1, wherein The joint plug (4) is an inorganic fiber rope.

3. The high temperature furnace flue duct configured with a tilting plate type sliding structure according to claim 1, wherein The first end plate and the second end plate are both planar plates, the gap between the two end plates is controlled within a design range through a limiting device, so that the contact area between the two end plates is reduced, thereby reducing friction and transmitting the acting force between the two end plates.

4. The high temperature furnace flue duct configured with a tilting plate type sliding structure according to claim 1, wherein The two end plates slide relatively parallel to each other during the operation of the boiler, but through structural design, the first end plate does not exceed the edge of the second end plate at all times.

5. The high temperature furnace flue duct configured with a tilting plate type sliding structure according to claim 1, wherein The through hole on one end plate (2) is welded and fixed with the end of the flue gas pipeline, and the other end plate (2) is fastened on the rigid beam on one side of the boiler furnace by bolts or pins.

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