A spiral fin tube and its assembly structure with a smoke baffle plate

Abstract

The present invention relates to a spiral fin tube and an assembly structure thereof with a smoke baffle plate, belonging to the technical field of power station boilers. The present invention comprises a furnace tube, a fin coiled along the axial direction of the furnace tube in the middle of the furnace tube, the fin being fixed to the outer wall of the furnace tube by welding, and a plurality of circles of movable fins at both ends of the fin that can extend and slide along the furnace tube under the action of external force. In the assembly structure of the spiral fin tube and the smoke baffle plate, the movable fins at both ends of the spiral fin tube form an elastic contact with the smoke baffle plate, and the fins are pressed against the smoke baffle plate by the elastic force and cover the tube hole, and the spiral fin tube and the smoke baffle plate form a sealing structure at the tube hole. Therefore, the present invention effectively avoids smoke leakage and greatly improves the utilization efficiency of waste heat of smoke; at the same time, the movable fins can form an elastic support for the smoke baffle plate, effectively preventing the smoke baffle plate from vibrating when flushed by smoke.

Description

Technical Field

[0001] The invention relates to a spiral fin tube and an assembly structure thereof with a smoke baffle plate, belonging to the technical field of power station boilers. Background Art

[0002] The spiral fin tube is a heating surface tube with fins on the outer wall. The fins coiled in the middle of the spiral fin tube are used to expand the heating area to improve the heat exchange efficiency of the spiral fin tube. The two ends of the spiral fin tube are left with light pipes for connecting the header. In order to ensure that as much flue gas as possible exchanges heat with the heating surface fins and prevent the formation of a smoke corridor in the area where the light pipe is located, which causes smoke loss, it is necessary to install a smoke baffle on the spiral fin tube screen to avoid smoke loss. Figure 1 As shown, the flue gas baffle plate 4 is arranged at the junction of the light tube 112 and the fin 12 on the spiral fin tube, and the light tube 112 passes through the tube hole 41 on the flue gas baffle plate 4 and is connected to the header 2, and the light tube 112 and the fin 12 are separated on both sides of the flue gas baffle plate 4. In order to avoid the flue gas baffle plate 4 from thermal expansion and lateral shearing of the light tube 112 when the waste heat boiler is running, the diameter of the tube hole 41 must be larger than the outer diameter of the light tube 112, that is, a certain gap must be left between the tube hole 41 and the light tube 112. Due to the existence of the above gap, high-temperature flue gas will inevitably leak at the tube hole 41. Although the amount of smoke leakage at a single tube hole 41 is relatively limited, in the case of a small amount accumulating into a large amount (taking a 9F grade waste heat boiler as an example, there are more than 10,000 spiral fin tubes on the heating surface of the fin tube, and correspondingly there are more than 20,000 tube holes matching the spiral fin tubes), such leakage is still an invisible killer that affects the efficient utilization of flue gas and waste heat in the waste heat boiler. Summary of the invention

[0003] The present invention mainly aims to solve the technical defect of the prior art that smoke leakage is easily caused by the gap between the spiral fin tube and the smoke baffle plate, and provide a spiral fin tube that can form a sealing fit with the smoke baffle plate to avoid smoke leakage.

[0004] The present invention solves the above technical problems mainly through the following technical solutions: the present invention includes a furnace tube, and a fin spirally coiled around the middle of the furnace tube along the axial direction of the furnace tube, characterized in that the middle of the fin is fixed to the outer wall of the furnace tube by welding, and both ends of the fin are provided with movable fins that can extend and slide along the furnace tube under the action of external force.

[0005] Preferably, the number of movable fins is no less than 5.

[0006] Preferably, the welding is high frequency resistance welding.

[0007] Preferably, the fin has teeth on one side away from the outer wall of the furnace tube.

[0008] Therefore, the present invention has a simple and reasonable structure and has the following advantages:

[0009] In the present invention, movable fins are arranged at both ends of the fins. Since the movable fins are only coiled around the spiral fin tube but not welded and fixed to the tube wall, the movable fins can extend and slide along the axial direction of the spiral fin tube under the action of external force.

[0010] When the present invention is assembled with the smoke baffle plate, before the smoke baffle plate is positioned and fixed, the smoke baffle plate is pushed toward the fin direction to a position in contact with the movable fin, and the smoke baffle plate is continuously pushed until the movable fin produces elastic contraction, at which time the smoke baffle plate is positioned and fixed by the positioning piece. The movable fin has a certain elastic tension after being pressed, which is equivalent to an elastic piece. The movable fin presses the smoke baffle plate and seals the pipe hole under the action of the elastic force.

[0011] Therefore, the present invention can form a sealed fit with the smoke baffle plate, solving the technical problem in the prior art of smoke leakage caused by the assembly gap between the spiral fin tube and the smoke baffle plate.

[0012] In the preferred embodiment of the present invention, the movable fins have no less than 5 sections, which can ensure that the movable fins have good elasticity and rigidity. On the one hand, the movable fins can form a tight fit with the smoke baffle at the tube hole under the action of elastic force, achieving a better sealing effect; on the other hand, the movable fins can form a good elastic support for the smoke baffle, effectively preventing the smoke baffle from vibrating when it is washed by smoke.

[0013] In a preferred embodiment of the present invention, the side of the fin away from the outside of the furnace tube is provided with teeth. The fin with teeth can be processed by a steel strip through a press. The fin is wound around the furnace tube by a winding device and fixed to the tube wall by high-frequency resistance welding. The winding and welding are completed simultaneously. Therefore, the present invention has the advantages of simple structure, convenient manufacturing, high production efficiency and low manufacturing cost.

[0014] The present invention can also solve the above-mentioned technical problems through the following technical solutions: the present invention includes a smoke barrier plate and a spiral fin tube. The smoke barrier plate is arranged at the junction of the light tube and the fin on the spiral fin tube and is positioned and fixed by a positioning piece. The light tube passes through the tube hole on the smoke barrier plate and is connected to the header. The positioning piece is fixedly connected to the light tube. It is characterized in that the spiral fin tube is any one of the spiral fin tubes described in claims 1-5, and the movable fins elastically press the smoke barrier plate and seal the tube hole.

[0015] Preferably, the positioning member and the furnace tube are detachably connected.

[0016] Therefore, the present invention has a simple and reasonable structure and has the following advantages:

[0017] In the present invention, the heating surface adopts a spiral fin tube provided with movable fins. Since the movable fins have a certain elasticity, even if the number of spiral fin tubes is extremely large, when installing the smoke baffle plate, by pushing the smoke baffle plate in the direction of the fins, the movable fins can be tightly attached to the smoke baffle plate and seal the tube holes under the action of elastic force.

[0018] Therefore, the present invention solves the technical problems existing in the prior art, effectively avoids smoke leakage at the pipe holes, and further realizes efficient utilization of the waste heat of the waste heat boiler flue gas.

[0019] In a preferred embodiment of the present invention, the positioning member and the light pipe are detachably connected, which can facilitate the installation and removal of the positioning member and the smoke baffle. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 It is a schematic diagram of the assembly structure of the spiral fin tube and the smoke baffle plate in the prior art;

[0021] Attached Figure 2 is a schematic diagram of a preferred embodiment of the present invention;

[0022] Attached Figure 3 It is a schematic diagram of the assembly structure of the spiral fin tube and the smoke baffle plate in the present invention;

[0023] Attached Figure 4 It is a schematic cross-sectional view of the fin in the present invention.

[0024] Explanation of the reference numerals: 1. spiral fin tube; 11. furnace tube; 112. bare tube; 12. fin; 121. movable fin; 1201. tooth plate; 2. header; 3. positioning member; 4. flue gas baffle; 41. tube hole. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0026] Embodiment 1: As attached Figure 2 , Attachment Figure 4 As shown, the present invention comprises a furnace tube 11, both ends of the furnace tube 11 are light tubes 112, and the middle part of the furnace tube 11 is coiled with fins 12;

[0027] The fin 12 is spirally wound around the outer wall of the furnace tube 11, the middle part of the fin 12 is fixedly connected to the outer wall of the furnace tube 11 by high-frequency resistance welding, and a tooth piece 1201 is processed on the side of the fin 12 away from the outer wall of the furnace tube 11;

[0028] There are five movable fins 121 at both ends of the fin 12. The movable fins 121 can be extended and slid along the axial direction of the furnace tube 11 under the action of external force.

[0029] When making the present invention, first place the furnace tube 11 and the steel strip with the tooth piece 1201 in the coiling device, and the steel strip and the furnace tube 11 are respectively connected to the positive and negative electrodes of the high-frequency resistance welding machine. When starting the coiling device, the high-frequency resistance welding machine is not powered on first, and the steel strip is coiled around the outer wall of the furnace tube 11 along the axial direction of the furnace tube 11 to form an "empty winding" effect. When the number of fins reaches 5 sections, the movable fin 121 at the starting end is completed; the coiling continues, and the high-frequency resistance welding machine is powered on at this time. The steel strip is fixed to the outer wall of the furnace tube 11 by high-frequency resistance welding while being coiled around the furnace tube 11; when the fin reaches the set number of sections, the coiling of the fin 12 fixed in the middle is completed; at this time, the high-frequency resistance welding machine is powered off, and the steel strip continues to coil, forming an "empty winding" effect again. When the movable fin 121 reaches 5 sections, the movable fin 121 at the end is also wound, and the coiling device is stopped at this time, and the steel strip is cut off at the last circle position of the fin 12, and the present invention is completed.

[0030] Embodiment 2: As attached Figure 3 As shown, the present invention comprises a smoke baffle plate 4, a spiral finned tube 1, the end of the spiral finned tube 1 is a light tube 112, the middle of the spiral finned tube 1 is coiled with fins 12, and the light tube 112 passes through the tube hole 41 on the smoke baffle plate 4 and is connected to the header 2;

[0031] The smoke baffle plate 4 is positioned and fixed at the junction of the light tube 112 and the fin 12 by the positioning member 3, and the smoke baffle plate 4 forms elastic contact with the movable fin 121; the light tube 112 and the header 2 are located on the outside of the smoke baffle plate 4, and the fin 12 is separated on the inside of the smoke baffle plate 4. The movable fin 121 is subjected to elastic force to press the smoke baffle plate 4 at the tube hole 41 and cover the tube hole 41;

[0032] The positioning members 3 are distributed on the smoke baffle plate 4 and are fixedly connected to the light pipe 112 in a detachable connection manner.

[0033] In the operation of the waste heat boiler of the present invention, when high-temperature flue gas flows through the fin heating surface of the spiral fin tube, the movable fin and the flue gas baffle plate form a sealed connection at the tube hole, so that no leakage of high-temperature flue gas occurs at the tube hole.

[0034] Therefore, the present invention improves the utilization efficiency of the waste heat of the flue gas of the waste heat boiler; at the same time, the smoke baffle plate and the movable fins form elastic contact, and the movable fins can provide elastic support for the smoke baffle plate, thereby effectively avoiding the vibration of the smoke baffle plate when being flushed by the flue gas, thereby ensuring the safe operation of the waste heat boiler.

[0035] Of course, the above drawings and embodiments are only used to explain and illustrate the present invention, and cannot be used as improper limitations of the present invention. Any technical solutions obtained by those skilled in the art making equivalent adjustments and changes based on the present invention fall within the protection scope of the present invention.

Claims

1. A spiral finned tube, comprising a furnace tube (11), a smoke baffle (4), a fin (12) spirally wound around the middle of the furnace tube (11) along the axial direction of the furnace tube (11), and smooth tubes (112) at both ends of the furnace tube (11), characterized in that: The middle part of the fin (12) is fixed to the outer wall of the furnace tube (11) by welding, and both ends of the fin (12) are provided with movable fins (121) which can be extended and slid along the furnace tube (11) under the action of external force; the smoke baffle plate (4) is arranged at the intersection of the light tube (112) and the fin (12) on the spiral fin tube (1) and is positioned and fixed by a positioning member (3); the movable fin (121) elastically presses the smoke baffle plate (4) and covers the tube hole (41) on the smoke baffle plate.

2. The spiral fin tube according to claim 1, characterized in that: The movable fins (121) have no less than 5 sections.

3. A spiral fin tube according to claim 1 or 2, characterized in that: The welding is high frequency resistance welding.

4. A spiral fin tube according to claim 1 or 2, characterized in that: The fin (12) has teeth (1201) on the side away from the furnace tube (11).

5. An assembly structure of a spiral fin tube and a smoke baffle, characterized in that: The spiral fin tube (1) is a spiral fin tube according to any one of claims 1 to 4, the light tube (112) passes through the tube hole (41) on the smoke baffle plate (4) to be connected to the header (2), and the positioning member (3) is fixedly connected to the light tube (112).

6. The assembly structure of a spiral fin tube and a smoke baffle plate according to claim 5, characterized in that: The positioning member (3) and the furnace tube (11) are detachably connected.

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