Sealing connection structure of rich-resistance tube bundle and tube plate and heat exchanger

Abstract

The embodiment of the invention provides a sealing connection structure for a rich-resistance tube bundle and a tube plate and a heat exchanger. The sealing connection structure comprises an outer sleeve, an inner core, a tube hole sealing ring, a water side sealing ring and an annular sealing ring. The inner tube wall of the outer sleeve is provided with internal threads, and one end is connected with the tube hole of the tube plate; the outer wall of the inner core is provided with external threads matched with the internal threads of the outer sleeve, one end of the inner core is provided with a conical portion matched with the pipe hole, the inner core is provided with a through hole penetrating through the inner core, the inner wall of the through hole is provided with an annular sealing groove, and the inner wall of the end, away from the conical portion, of the through hole is provided with an end face groove. The pipe hole sealing ring is arranged between the end surface of the conical part and the inner wall of the pipe hole; the water side sealing ring is embedded in the end face groove, and the annular sealing ring is embedded in the annular sealing groove. When the inner core is screwed into the outer sleeve in a rotating mode, the conical portion of the inner core is connected with the pipe hole sealing ring in a pressing mode, the extending end of the rich-resistance pipe is connected with the water side sealing ring in a pressing mode, and the annular sealing ring is tightly attached to the outer wall of the rich-resistance pipe.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of heat exchanger sealing connection technology, specifically relating to a sealing connection structure between a Funai tube bundle and a tube sheet, and a heat exchanger. Background Technology

[0002] Furein tubes, as a high-performance, corrosion-resistant, and high-temperature-resistant material, are widely used in heat exchangers in industries such as chemical, power, and metallurgy. Their excellent corrosion resistance and heat resistance can meet the heat exchange requirements under harsh operating conditions. However, Furein tubes have significant limitations in terms of material properties: First, Furein tubes cannot be connected to tube sheets using traditional welding methods, as the high temperatures of welding will damage their material structure and lead to performance failure; second, Furein tubes are relatively brittle and prone to cracking under stress, and are extremely sensitive to structural stress concentration, making conventional rigid connection structures prone to tube breakage; third, during heat exchanger operation, Furein tubes may leak due to factors such as media corrosion and fatigue, requiring convenient disassembly and replacement solutions, while existing sealing structures are mostly one-time connections, which are difficult to disassemble and have high maintenance costs.

[0003] Existing connection methods between FUNI tubes and tube sheets mainly include expansion joints and packing seals, but both have significant drawbacks. Expansion joints rely on an interference fit between the tube body and the tube bore to achieve a seal, which easily leads to stress concentration and cracking of the FUNI tubes. Packing seals have poor sealing reliability; after long-term operation, the packing is prone to aging and failure, resulting in leakage of flue gas, air, or water-side media, affecting the heat exchanger's operating efficiency and safety. Furthermore, existing structures cannot achieve multiple sealing protections, cannot meet the high sealing requirements of operating conditions, and are inconvenient to disassemble. After a FUNI tube leaks, it is difficult to replace it quickly, severely impacting equipment maintenance efficiency.

[0004] Therefore, considering the material characteristics and usage requirements of FUNI pipe, there is an urgent need to design a sealing connection structure that requires no welding, avoids stress concentration, provides reliable sealing, and is easy to disassemble and replace, in order to solve the problems of sealing failure, maintenance difficulties, and easy damage to FUNI pipe in the existing technology. Summary of the Invention

[0005] The embodiments disclosed herein aim to at least solve one of the technical problems existing in the prior art, and provide a sealing connection structure between a funnel tube bundle and a tube sheet and a heat exchanger.

[0006] A first aspect of the embodiments of this disclosure provides a sealing connection structure between a funnel bundle and a tube sheet, comprising: Outer tube, inner core, pipe hole sealing ring, water-side sealing ring and annular sealing ring; The inner wall of the outer sleeve is provided with internal threads, and one end of it is connected to the tube hole of the tube sheet. The outer wall of the inner core has an external thread that matches the internal thread of the outer sleeve. One end of the inner core has a conical portion that matches the pipe hole for installation. The inner core has a through hole that penetrates its interior. An annular sealing groove is formed on the inner wall of the through hole. An end face groove is formed on the inner wall of the end of the through hole away from the conical portion. The pipe hole sealing ring is disposed between the end face of the conical portion and the inner wall of the pipe hole; the water side sealing ring is embedded in the groove of the end face, and the annular sealing ring is embedded in the annular sealing groove; When the inner core is rotated and screwed into the outer tube, the conical part of the inner core is pressed against the pipe hole sealing ring, the protruding end of the Funai tube is pressed against the water side sealing ring, and the annular sealing ring is tightly fitted to the outer wall of the Funai tube.

[0007] Optionally, the shape of the conical portion is adapted to the shape of the tube hole, and the cone angle of the conical portion is 15°-30°.

[0008] Optionally, the groove depth of the end face groove is 8mm-46mm.

[0009] Optionally, a plurality of annular sealing grooves are provided at intervals along the axial direction of the through hole; The annular sealing ring is at least one in number, and the material of the annular sealing ring includes modified polytetrafluoroethylene.

[0010] Optionally, the inner core is provided with an injection hole communicating with the tube hole; the sealing connection structure further includes a set screw disposed at the opening of the injection hole.

[0011] Optionally, the internal thread of the outer sleeve and the external thread of the inner core are both fine threads with a thread profile angle of 60°.

[0012] Optionally, the inner core is provided with a wrench groove for screwing and disassembling.

[0013] Optionally, the inner wall of the tube hole is provided with a wear-resistant coating, and the surface of the conical part is provided with a polishing layer.

[0014] Optionally, the thickness of the water-side sealing ring is 2mm-4mm; when the inner core is screwed to the working position, the compression deformation of the water-side sealing ring under the axial clamping force at the end of the funnel pipe is controlled within the range of 30% to 50%.

[0015] A second aspect of the embodiments of this disclosure provides a heat exchanger including a tube sheet, Furniture tubes, and the aforementioned sealing connection structure between the Furniture tube bundle and the tube sheet, wherein the Furniture tube bundle is sealed and fixed to the tube sheet through the sealing connection structure.

[0016] The beneficial effects of the embodiments of this disclosure include: 1. Multiple sealing design ensures tight sealing: The flue gas / air side is sealed by the pipe hole sealing ring, and the water side sealing ring and the annular sealing ring of the inner core through hole form a multi-stage water side seal, which effectively prevents media leakage and is suitable for high sealing requirements.

[0017] 2. Adapts to the material characteristics of FUNI tubing: No welding connection is required; sealing is achieved through threaded tightening, avoiding damage to the FUNI tubing material caused by the high temperatures of welding. Precise matching of the FUNI tubing extension length and inner core structure dimensions ensures uniform stress on the FUNI tubing during the sealing and tightening process, preventing brittle fracture caused by stress concentration.

[0018] 3. Quick disassembly and maintenance: The threaded connection structure, combined with the wrench groove design at the rear of the inner core, allows for quick disassembly of the inner core. This enables timely replacement in case of leakage in the Funai pipe, reducing maintenance costs and improving equipment operation and maintenance efficiency.

[0019] 4. Strong structural stability: The outer tube is concentrically welded to the tube sheet, the inner core and the outer tube threads are precisely matched, the conical part fits tightly with the conical hole inside the tube hole, the overall structure is evenly stressed and has a long service life. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of a sealing connection structure between a tube bundle and a tube sheet according to an embodiment of the present disclosure. Figure 2 This is a cross-sectional structural schematic diagram of a sealing connection structure between a tube bundle and a tube sheet according to an embodiment of the present disclosure; Figure 3 This is a cross-sectional schematic diagram of a sealing connection structure between a tube bundle and a tube sheet according to another embodiment of this disclosure.

[0021] In the diagram, 1 is the tube sheet; 2 is the outer tube; 3 is the inner core; 4 is the FUNI tube; 5 is the tube hole sealing ring; 6 is the water-side sealing ring; 7 is the annular sealing ring; 8 is the injection hole; 9 is the set screw; 101 is the tube hole; 301 is the conical part; 302 is the through hole; 303 is the annular sealing groove; 304 is the end face groove; and 305 is the wrench groove. Detailed Implementation

[0022] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] The embodiments of this application will be further described in detail below with reference to the accompanying drawings and examples. The detailed descriptions and accompanying drawings of the following embodiments are used to exemplarily illustrate the principles of this application, but should not be used to limit the scope of this application; that is, this application is not limited to the described embodiments. In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicating orientation or positional relationships are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not strictly vertical, but within the allowable error range. "Parallel" is not strictly parallel, but within the allowable error range.

[0024] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application depending on the specific circumstances.

[0025] like Figure 1-3 As shown, this application provides a sealing connection structure between a funnel tube bundle and a tube sheet, including an outer tube 2, an inner core 3, a tube hole sealing ring 5, a water-side sealing ring 6, and an annular sealing ring 7.

[0026] The inner wall of the outer sleeve 2 is provided with internal threads, one end of which is welded and fixed to the tube sheet 1, and the outer sleeve 2 and the tube hole 101 on the tube sheet 1 are concentrically arranged.

[0027] The inner core 3 has an external thread on its outer tube wall, which is adapted to the internal thread of the outer tube 2. The front end of the inner core 3 is a conical part 301, and the tube hole 101 of the tube plate 1 is an inner conical hole. The conical part 301 matches and fits the inner conical end face of the tube hole 101. The inner core 3 has a through hole 302 inside, and the inner wall of the through hole 302 has an annular sealing groove 303.

[0028] The pipe hole sealing ring 5 is disposed on the inner conical end face of the pipe hole 101, the water side sealing ring 6 is disposed in the end face groove 304 at the rear end of the inner core 3, and the annular sealing ring 7 is embedded in the annular sealing groove 303 of the through hole 302.

[0029] One end of the Funai tube 4 passes through the tube hole 101 of the tube plate 1 and extends out to a predetermined length. The structural dimensions of the Funai tube 4 of the predetermined length match the end face groove 304 at the rear end of the inner core 3. When the inner core 3 is rotated and screwed into the outer tube 2, the conical part 301 at the front end of the inner core 3 presses against the tube hole sealing ring 5, the extended end of the Funai tube 4 presses against the water side sealing ring 6, and the annular sealing ring 7 fits tightly against the outer wall of the Funai tube 4, forming a multi-layer seal.

[0030] In some embodiments, the cone angle of the conical portion 301 at the front end of the inner core 3 is 15°-30°, and the cone angle of the conical portion 301 is consistent with that of the tube hole 101, so as to ensure that the contact surface is evenly stressed and improve the sealing stability.

[0031] In some embodiments, the length of the Funai tube 4 extending out of the tube sheet 1 is 10mm-50mm depending on the tube diameter, and the groove depth of the end face groove 304 at the rear end of the inner core 3 is 8mm-46mm. Through precise size matching, when the water-side sealing ring 6 is pressed, the end of the Funai tube 4 is subjected to uniform force, avoiding stress concentration.

[0032] In some embodiments, at least one annular sealing ring 7 is provided, which is distributed at intervals along the axial direction of the through hole 302 of the inner core 3. The material of the annular sealing ring 7 is modified polytetrafluoroethylene, which has both temperature resistance and elasticity, further enhancing the water-side sealing effect.

[0033] In some embodiments, the inner core 3 has an injection hole 8 on the outer side of its rear end, which leads to the through hole 302 of the inner core 3. After installation, an injection gun is used to inject adhesive into the cavity between the water-side sealing ring 6 and the annular sealing ring 7 in the through hole 302. Then, the injection hole 8 is sealed with a set screw 9. When the water-side polytetrafluoroethylene sealing gasket leaks, the adhesive expands upon contact with water to form a seal, ensuring the reliability of the water-side seal.

[0034] In some embodiments, the outer sleeve 2 is welded to the tube sheet 1 by argon arc welding, and the weld joint is provided with a transition fillet to avoid stress concentration during welding and damage to the tube sheet 1, while improving the overall structural integrity.

[0035] In some embodiments, the internal thread of the outer sleeve 2 and the external thread of the inner core 3 are both fine threads with a thread profile angle of 60°. The fine thread has a small pitch, which provides better sealing performance. Furthermore, the inner core 3 is subjected to stable force during the tightening process, thus avoiding impact on the funnel tube 4.

[0036] In some embodiments, the rear end of the inner core 3 is provided with a hexagonal wrench groove 305 or a box wrench groove 305, which facilitates quick unscrewing and disassembly using conventional tools, thereby improving maintenance efficiency.

[0037] In some embodiments, the inner wall of the tube hole 101 of the tube sheet 1 is provided with a wear-resistant coating, and the surface of the front conical part 301 of the inner core 3 is provided with a polishing layer to reduce friction and wear on the mating surface and extend the service life of the structure.

[0038] In some embodiments, the thickness of the water-side sealing ring 6 is 2mm-4mm, and the compression is controlled at 30%-50% to ensure a tight seal while avoiding excessive compression that could damage the end of the funnel 4.

[0039] According to a second aspect of the present invention, a heat exchanger is provided, comprising a tube sheet 1, a Furniture tube 4, and a sealing connection structure between the Furniture tube 4 bundle and the tube sheet 1 as described in any one of the above, wherein the Furniture tube 4 bundle is sealed and fixed to the tube sheet 1 through the sealing connection structure to achieve reliable isolation between the flue gas / air side and the water side.

[0040] The technical advantages of this invention are as follows: 1. Multiple sealing design ensures tight sealing: The flue gas / air side is sealed by the pipe hole sealing ring, and the water side sealing ring and the annular sealing ring of the inner core through hole form a multi-stage water side seal, which effectively prevents media leakage and is suitable for high sealing requirements.

[0041] 2. Adapts to the material characteristics of FUNI tubing: No welding connection is required; sealing is achieved through threaded tightening, avoiding damage to the FUNI tubing material caused by the high temperatures of welding. Precise matching of the FUNI tubing extension length and inner core structure dimensions ensures uniform stress on the FUNI tubing during the sealing and tightening process, preventing brittle fracture caused by stress concentration.

[0042] 3. Quick disassembly and maintenance: The threaded connection structure, combined with the wrench groove design at the rear of the inner core, allows for quick disassembly of the inner core. This enables timely replacement in case of leakage in the Funai pipe, reducing maintenance costs and improving equipment operation and maintenance efficiency.

[0043] 4. Strong structural stability: The outer tube is concentrically welded to the tube sheet, the inner core and the outer tube threads are precisely matched, the conical part fits tightly with the inner conical hole of the tube hole, the overall structure is evenly stressed and has a long service life.

[0044] For a specific example, see Figure 1 This invention provides a sealing connection structure between the FUNI tube bundle and the tube sheet, which is adapted to the material characteristics of FUNI tubes to achieve reliable sealing and convenient maintenance.

[0045] Specifically, the sealing connection structure includes an outer sleeve 2, an inner core 3, a pipe hole sealing ring 5, a water-side sealing ring 6, and an annular sealing ring 7.

[0046] The outer sleeve 2 has an internal thread, and one end of it is welded to the tube sheet 1 by argon arc welding. The weld joint is provided with a transition fillet. The outer sleeve 2 and the tube hole 101 (inner conical hole) on the tube sheet 1 are concentrically set to ensure assembly coaxiality.

[0047] The inner core 3 has an external thread that matches the internal thread of the outer sleeve 2. Both use fine threads with a thread angle of 60° to improve sealing performance and smooth tightening. The front end of the inner core 3 is a conical part 301 with a cone angle of 20°, which matches the cone angle of the tube hole 101 (inner conical hole) of the tube sheet 1, achieving a tight fit. The inner core 3 has a through hole 302 inside, and the inner wall of the through hole 302 has three annular sealing grooves 303, which are spaced apart along the axial direction.

[0048] The inner core 3 has an injection hole 8 on the outer side of its rear end, which leads to the through hole 302 of the inner core 3. After installation, use an injection gun to apply expansion adhesive to the cavity between the water-side sealing ring 6 and the annular sealing ring 7 inside the through hole 302, and then use the set screw 9 to seal the injection hole 8. When the water-side sealing ring 6 leaks, the expansion adhesive expands upon contact with water to form a seal, ensuring reliable water-side sealing.

[0049] The tube hole sealing ring 5 is disposed on the inner conical end face of the tube hole 101 of the tube sheet 1 to seal the leakage of flue gas or air inside the heat exchanger. The water side sealing ring 6 is disposed in the end face groove 304 at the rear end of the inner core 3, and the end face groove 304 has a depth of 4mm. The annular sealing ring 7 is embedded in the annular sealing groove 303 of the through hole 302 of the inner core 3, and is made of modified polytetrafluoroethylene, which has both temperature resistance and elasticity.

[0050] One end of the Funai tube 4 passes through the tube hole 101 of the tube plate 1 and extends 8mm (preset length). This extension length matches the size of the end face groove 304 at the rear end of the inner core 3. The rear end of the inner core 3 is provided with a hexagonal wrench groove for easy tool tightening.

[0051] During assembly, the Funai tube 4 is passed through the tube hole 101 of the tube plate 1, ensuring an extension length of 8mm. A tube hole sealing ring 5 is placed on the inner conical end face of the tube hole 101. A water-side sealing ring 6 is placed in the end face groove 304 of the inner core 3, and an annular sealing ring 7 is embedded in the annular sealing groove 303. The inner core 3 is aligned with the outer tube 2, and the wrench groove 305 of the inner core 3 is tightened using a hex wrench, gradually screwing the inner core 3 into the inner thread of the outer tube 2. As the inner core 3 is screwed in, the front conical part 301 gradually fits into the inner conical hole of the tube plate 1, pressing the tube hole sealing ring 5 to achieve a primary seal on the flue gas / air side.

[0052] At the same time, the extended end of the Funai pipe 4 contacts and gradually presses against the water-side sealing ring 6 at the rear end of the inner core 3. The compression of the water-side sealing ring 6 is controlled at 40%, achieving a first-level water-side seal. The annular sealing ring 7 inside the through hole 302 of the inner core 3 fits tightly against the outer wall of the Funai pipe 4, forming a second-level and third-level water-side seal, ensuring a tight seal on the water-side pipe hole.

[0053] When a leak is detected in the Furniture tube 4, the inner core 3 can be quickly disassembled by turning it in the opposite direction with a hex wrench. The damaged Furniture tube 4 can then be removed and replaced with a new tube. The inner core 3 can then be reassembled following the steps described above to complete the maintenance.

[0054] In some embodiments, the inner wall of the tube hole 101 of the tube sheet 1 is provided with a ceramic wear-resistant coating, and the surface of the front conical part 301 of the inner core 3 is polished with a roughness Ra≤0.8μm, which reduces the friction and wear of the mating surface and extends the service life of the structure.

[0055] In some embodiments, the number of annular sealing rings 7 can be adjusted to 1-3 according to sealing requirements, further enhancing the water-side sealing effect.

[0056] According to a second aspect of the present invention, a heat exchanger is provided, comprising a tube sheet 1, a Furniture tube bundle, and the aforementioned sealing connection structure. The Furniture tube bundle is sealed and fixed to the tube sheet 1 through the sealing connection structure, thereby achieving reliable isolation between the flue gas / air side and the water side. This heat exchanger is suitable for high-temperature corrosive conditions in the chemical and power industries.

[0057] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A sealing connection structure between a funnel tube bundle and a tube sheet, characterized in that, include: Outer tube, inner core, pipe hole sealing ring, water-side sealing ring and annular sealing ring; The inner wall of the outer sleeve is provided with internal threads, and one end of it is connected to the tube hole of the tube sheet. The outer wall of the inner core has an external thread that matches the internal thread of the outer sleeve. One end of the inner core has a conical portion that matches the pipe hole for installation. The inner core has a through hole that penetrates its interior. An annular sealing groove is formed on the inner wall of the through hole. An end face groove is formed on the inner wall of the end of the through hole away from the conical portion. The pipe hole sealing ring is disposed between the end face of the conical portion and the inner wall of the pipe hole; the water side sealing ring is embedded in the groove of the end face, and the annular sealing ring is embedded in the annular sealing groove; When the inner core is rotated and screwed into the outer tube, the conical part of the inner core is pressed against the pipe hole sealing ring, the protruding end of the Funai tube is pressed against the water side sealing ring, and the annular sealing ring is tightly fitted to the outer wall of the Funai tube.

2. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, The shape of the conical portion is adapted to the shape of the tube hole, and the cone angle of the conical portion is 15°-30°.

3. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, The groove depth of the end face is 8mm-46mm.

4. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, Multiple annular sealing grooves are provided at intervals along the axial direction of the through hole; The annular sealing ring is at least one in number, and the material of the annular sealing ring includes modified polytetrafluoroethylene.

5. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, The inner core is provided with an injection hole that communicates with the tube hole; the sealing connection structure also includes a set screw provided at the opening of the injection hole.

6. The sealing connection structure between the FUN tube bundle and the tube sheet according to claim 1, characterized in that, Both the internal thread of the outer sleeve and the external thread of the inner core are fine threads with a thread angle of 60°.

7. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, The inner core is provided with a wrench groove for screwing and disassembling.

8. The sealing connection structure between the tube bundle and the tube sheet according to claim 1, characterized in that, The inner wall of the tube hole is provided with a wear-resistant coating, and the surface of the conical part is provided with a polishing layer.

9. A sealing connection structure between a funnel tube bundle and a tube sheet according to claim 1, characterized in that, The thickness of the water-side sealing ring is 2mm-4mm; when the inner core is screwed to the working position, the compression deformation of the water-side sealing ring under the axial clamping force at the end of the funnel pipe is controlled within the range of 30% to 50%.

10. A heat exchanger, characterized in that, The invention includes a tube sheet, a Furniture tube, and a sealing connection structure between the Furniture tube bundle and the tube sheet as described in any one of claims 1-9, wherein the Furniture tube bundle is sealed and fixed to the tube sheet through the sealing connection structure.

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