Double expansion joint based on circulating fluidized bed boiler

Abstract

The utility model discloses a double expansion joint based on a circulating fluidized bed boiler, which comprises a metal expansion joint, both ends of the metal expansion joint are connected with end plates, the outer side of the metal expansion joint is provided with a middle piece, the middle piece is connected to one side of each end plate, and the middle piece is connected with the end plates through bolts. A wear-resistant coating is arranged between the metal expansion joint and the middleware, the wear-resistant coating is uniformly smeared on the surface of the metal expansion joint, a heat preservation quilt is arranged between the middleware and the wear-resistant coating, the heat preservation quilt is laid on the wear-resistant coating, and a non-metal expansion joint is arranged on the outer side of the metal expansion joint. The non-metal expansion joint is connected to the outer side of the middleware, due to the double-expansion-joint structural design of the expansion joint, the problem that a single expansion joint is cracked due to excessive deformation is solved, the reliability of the expansion joint is remarkably improved, the service life of the expansion joint is remarkably prolonged, the frequency of equipment maintenance and replacement is reduced, and the operation cost is reduced.

Description

Technical Field

[0001] The utility model relates to the field of boiler expansion joints, in particular to a double expansion joint based on a circulating fluidized bed boiler. Background Art

[0002] Circulating fluidized bed boilers (CFBs) are a highly efficient, low-pollution, clean combustion technology widely used in numerous sectors, including power generation, heating, and chemical engineering. By burning fuels (such as coal and biomass) in a fluidized state, they achieve excellent combustion efficiency and pollutant emission control. Their combustion process offers advantages such as wide fuel adaptability, high combustion efficiency, a wide load adjustment range, and low nitrogen oxide emissions, making them a key component of modern energy technology.

[0003] In the existing technology, the outlet of the secondary superheater adopts a metal corrugated expansion joint. As the unit starts and stops for peak regulation, very high requirements are placed on the metal expansion joint. Frequent stretching will cause fatigue cracks. At the same time, the erosion and wear of soot will cause further damage to the metal expansion joint and a sharp reduction in its service life.

[0004] Therefore, it is necessary to propose a double expansion joint based on a circulating fluidized bed boiler to solve the above problems. Utility Model Content

[0005] The purpose of the utility model is to provide a double expansion joint based on a circulating fluidized bed boiler to solve the problem that as the unit starts and stops to adjust the peak, high requirements are placed on the metal expansion joint, frequent stretching will cause fatigue cracks, and at the same time, the erosion and wear of soot will cause the metal expansion joint to be damaged further and its service life will be sharply reduced.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A double expansion joint based on a circulating fluidized bed boiler includes a metal expansion joint, both ends of the metal expansion joint are connected to end plates, two middle pieces are provided on the outside of the metal expansion joint, the two middle pieces are respectively connected to one side of the end plate, and the middle pieces and the end plates are fixedly connected by bolts, a wear-resistant coating is provided between the metal expansion joint and the middle pieces, the wear-resistant coating is evenly applied to the surface of the metal expansion joint, a thermal insulation blanket is provided between the middle piece and the wear-resistant coating, the thermal insulation blanket is applied on the wear-resistant coating, the middle piece and the thermal insulation blanket are tightly fitted, and a non-metallic expansion joint is provided on the outside of the metal expansion joint, and the non-metallic expansion joint is connected to the outside of the middle piece.

[0008] Preferably, an intermediate plate is connected to the middle position of the outer side of the metal expansion joint, and the other ends of the two intermediate pieces are respectively connected to the two sides of the intermediate plate.

[0009] Preferably, three pull rods are installed on the end plate, nuts are threadedly installed on the ends of the pull rods, and the pull rods are passed through the middle plate.

[0010] Preferably, the metal expansion joint is connected to a bellows, the metal expansion joint is connected to a through pipe, and the non-metallic expansion joint is made of a non-metallic composite material.

[0011] Preferably, the two end plates are connected to flanges on their sides away from each other, and a sealing gasket is provided between the end plates and the flanges, and the sealing gasket is fixedly mounted on the flanges.

[0012] Preferably, the flange is connected to an end pipe, and the end pipe is fixedly connected to the flange by bolts.

[0013] The technical effects and advantages of this utility model are:

[0014] 1. The double expansion joint structure design, with the internal metal expansion joint and the external non-metallic expansion joint working in coordination, greatly enhances the ability to compensate for thermal expansion and contraction of the pipeline. Under the complex working conditions of the circulating fluidized bed boiler, it can effectively cope with frequent and large temperature changes, avoiding the problem of single expansion joints being torn due to excessive deformation, significantly improving the reliability and service life of the expansion joint, reducing the frequency of equipment maintenance and replacement, and lowering operating costs.

[0015] 2. The wear-resistant coating reduces the wear of the metal expansion joint caused by soot erosion and extends its service life; the thermal insulation blanket not only helps maintain the thermal efficiency of the system, but also stabilizes the working temperature environment of the expansion joint, reduces the stress caused by temperature changes, and improves the ability of the entire expansion joint to operate stably and long-term in harsh environments;

[0016] 3. Metal expansion joints, non-metallic expansion joints, wear-resistant coatings, thermal insulation blankets, sealing gaskets and other components together constitute a strict sealing system. During the operation of the boiler, it effectively prevents soot and other solid particles from leaking from the expansion joints. This not only avoids environmental pollution, protects the surrounding environment and the health of operators, but also reduces the damage caused by soot leakage to other equipment, thereby improving the operational stability and reliability of the entire boiler system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model is a schematic diagram of a double expansion joint structure based on a circulating fluidized bed boiler.

[0018] Figure 2 It is a schematic diagram of the internal structure of the utility model.

[0019] Figure 3 This is a schematic diagram of the bellows structure of the utility model.

[0020] Figure 4 It is a schematic structural diagram of the right view of the utility model.

[0021] In the figure: 1. Metal expansion joint; 2. End plate; 3. Intermediate piece; 4. Wear-resistant coating; 5. Insulation blanket; 6. Non-metallic expansion joint; 7. Intermediate plate; 8. Tie rod; 9. Nut; 10. Bellows; 11. Flange; 12. Sealing gasket; 13. End pipe. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] The utility model provides Figure 1-Figure 4 A double expansion joint based on a circulating fluidized bed boiler is shown, comprising a metal expansion joint 1, both ends of which are connected to end plates 2, two intermediate pieces 3 being provided on the outside of the metal expansion joint 1, the two intermediate pieces 3 being respectively connected to one side of the end plates 2, and the intermediate pieces 3 being fixedly connected to the end plates 2 by bolts, a wear-resistant coating 4 being provided between the metal expansion joint 1 and the intermediate pieces 3, the wear-resistant coating 4 being evenly applied to the surface of the metal expansion joint 1, a thermal insulation blanket 5 being provided between the intermediate piece 3 and the wear-resistant coating 4, the thermal insulation blanket 5 being applied on the wear-resistant coating 4, the intermediate piece 3 being tightly fitted to the thermal insulation blanket 5, a non-metallic expansion joint 6 being provided on the outside of the metal expansion joint 1, the non-metallic expansion joint 6 being connected to the outside of the intermediate piece 3;

[0024] When the circulating fluidized bed boiler is in operation, the temperature of the medium in the piping system changes, causing the connected pipes to expand and contract due to heat. The metal expansion joint 1 located inside plays a role first. Its own structure can freely expand and contract within a certain range to absorb the axial, lateral or angular displacement of the pipe. The non-metallic expansion joint 6 has a certain degree of flexibility and deformability due to the use of non-metallic composite materials. During the deformation of the metal expansion joint 1, the non-metallic expansion joint 6 can adjust its shape accordingly with the displacement of the metal expansion joint 1, further compensating for the large deformation of the piping system caused by thermal expansion and contraction, ensuring that the entire connection part always maintains a good sealing state, and preventing leakage due to excessive displacement;

[0025] During operation, especially in a circulating fluidized bed boiler environment, the metal expansion joint 1 is subject to erosion and wear from solid particles such as soot. Placing the wear-resistant coating 4 near the metal expansion joint 1 directly protects the surface of the metal expansion joint 1, reducing the scratching and wear on the metal surface caused by the high-speed flow of soot particles, thereby extending the service life of the metal expansion joint 1. The presence of the wear-resistant coating 4 can improve the surface roughness and adhesion of the metal expansion joint 1, providing a better foundation for the installation of the insulation blanket 5. It can make the insulation blanket 5 more firmly attached to the metal expansion joint 1, preventing the insulation blanket 5 from falling off or shifting due to factors such as vibration and thermal expansion and contraction during long-term operation, thereby ensuring the durability of the insulation effect.

[0026] An intermediate plate 7 is connected to the middle position of the outer side of the metal expansion joint 1, and the other ends of the two intermediate pieces 3 are connected to both sides of the intermediate plate 7 respectively;

[0027] Three tie rods 8 are installed on the end plate 2. The ends of the tie rods 8 are all threaded with nuts 9. The tie rods 8 are passed through the middle plate 7.

[0028] When the metal expansion joint 1 is subjected to the pressure, vibration and stress caused by thermal expansion and contraction of the pipeline system during operation, the pull rod 8 can connect the two end plates 2 to form a stable frame structure. Through the tightening action of the nut 9, the pull rod 8 applies a certain pre-tightening force to the end plates 2, so that the end plates 2 maintain a relatively fixed position relationship, preventing the end 2 from excessive deformation or displacement when subjected to force.

[0029] The expansion joint 1 is connected to a bellows 10, the expansion joint 1 is connected to a through pipe, and the non-metallic expansion joint 6 is made of a non-metallic composite material;

[0030] The through pipe connects different components in the metal expansion joint 1 , and it can make the structure of the metal expansion joint 1 more continuous and complete, ensuring the smooth flow of the medium in the metal expansion joint 1 .

[0031] The two end plates 2 are connected to flanges 11 on their sides away from each other. A sealing gasket 12 is provided between the end plates 2 and the flanges 11. The sealing gasket 12 is fixedly mounted on the flanges 11.

[0032] The flange 11 is connected to an end pipe 13, and the end pipe 13 is fixedly connected to the flange 11 by bolts;

[0033] The end pipe 13 can introduce the medium in the pipeline into the metal expansion joint 1 and transmit the force borne by the metal expansion joint 1 to the pipeline system. During operation, the flow of the medium in the pipeline will generate pressure, impact force, etc. These forces are transmitted to the various components of the metal expansion joint 1 through the end pipe 13. At the same time, the reaction force generated by the metal expansion joint 1 when compensating for deformation will also be transmitted back to the pipeline system through the end pipe 13.

[0034] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions merely illustrate the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed for the present invention is defined by the appended claims and their equivalents.

Claims

1. A double expansion joint based on a circulating fluidized bed boiler, comprising a metal expansion joint (1), characterized in that: Both ends of the metal expansion joint (1) are connected to end plates (2), two middle pieces (3) are provided on the outside of the metal expansion joint (1), the two middle pieces (3) are respectively connected to one side of the end plate (2), and the middle pieces (3) and the end plate (2) are fixedly connected by bolts, a wear-resistant coating (4) is provided between the metal expansion joint (1) and the middle piece (3), the wear-resistant coating (4) is evenly applied on the surface of the metal expansion joint (1), a thermal insulation blanket (5) is provided between the middle piece (3) and the wear-resistant coating (4), the thermal insulation blanket (5) is applied on the wear-resistant coating (4), the middle piece (3) and the thermal insulation blanket (5) are tightly fitted, and a non-metallic expansion joint (6) is provided on the outside of the metal expansion joint (1), and the non-metallic expansion joint (6) is connected to the outside of the middle piece (3).

2. The double expansion joint for a circulating fluidized bed boiler according to claim 1, characterized in that: An intermediate plate (7) is connected to the middle position of the outer side of the metal expansion joint (1), and the other ends of the two intermediate components (3) are respectively connected to the two sides of the intermediate plate (7).

3. The double expansion joint for a circulating fluidized bed boiler according to claim 1, characterized in that: Three pull rods (8) are installed on the end plate (2), and nuts (9) are threadedly installed on the ends of the pull rods (8). The pull rods (8) are passed through the middle plate (7).

4. The double expansion joint for a circulating fluidized bed boiler according to claim 1, characterized in that: The metal expansion joint (1) is connected to a bellows (10), the metal expansion joint (1) is connected to a through pipe, and the non-metallic expansion joint (6) is made of a non-metallic composite material.

5. The double expansion joint for a circulating fluidized bed boiler according to claim 1, characterized in that: The two end plates (2) are both connected to flanges (11) on the sides away from each other, and a sealing gasket (12) is provided between the end plates (2) and the flanges (11), and the sealing gasket (12) is fixedly mounted on the flanges (11).

6. The double expansion joint for a circulating fluidized bed boiler according to claim 5, characterized in that: The flange (11) is connected to an end pipe (13), and the end pipe (13) is fixedly connected to the flange (11) by bolts.

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