High-pressure heat exchanger sealing device with secondary leakage prevention function
By designing a sealing device with secondary leakage prevention function in high-pressure heat exchangers, including flange connection, Ω ring seal assembly, arc sealing ring and tight-draining unit, combined with real-time pressure monitoring and DSC alarm system, the Ω ring is solved The sealing structure is leaked due to corrosion and welding defects, achieving higher seal reliability and safe production.
Patent Information
- Application Number
- CN202421129709.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-22
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-22
AI Technical Summary
The sealing structure of Ω ring high-voltage heat exchanger leaks due to corrosion and welding defects, and is difficult to effectively monitor, which poses safety hazards and production losses.
A high-pressure heat exchanger sealing device with secondary anti-leakage function is designed, including a flange connection mechanism, an Ω ring sealing assembly, an arc sealing ring and a tight-distance unit, forming four sealing barriers and equipped with a real-time pressure monitoring unit. and DSC alarm system to realize online monitoring and decompression tightly.
It enhances the seal reliability of high-pressure heat exchangers, reduces leakage risks, monitors and discharges leaked media in a timely manner, avoids further corrosion and production losses, and ensures safe production.
Smart Images
Figure CN222255437U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of heat exchangers, in particular to a high-pressure heat exchanger sealing device with a secondary anti-leakage function. Background Art
[0002] The high-pressure heat exchanger (Ω ring high-pressure heat exchanger) of the residue hydrocracking unit has the following heat exchange media: vacuum residue oil (tube side), hot high-fraction gas (shell side). The Ω ring sealing structure is a typical welding sealing structure. Due to the special connection form of the Ω ring sealing structure, the reliability of the sealing of the high-pressure and high-temperature heat exchanger is guaranteed. The main bolts have a smaller pre-tightening and sealing load, which reduces the size and weight of the equipment flange and main bolts. Therefore, compared with the threaded locking ring sealing structure, the Ω ring sealing structure has the advantages of simple structure, convenient disassembly and maintenance, reliable sealing, wide range of pressure and temperature applications, and low cost. Its disadvantage is that the residual liquid in the Ω ring cavity is difficult to remove, which can easily cause corrosion to the Ω ring.
[0003] The maintenance cycle of high-pressure heat exchangers is generally 6-8 years, and the overhaul cycle of hydrocracking units is 3-4 years. If leakage occurs during operation, it will seriously threaten the safety of personnel and facilities. If the unit is shut down, it will lead to a reduction in production of the entire plant, and the economic impact is immeasurable. However, in practice, it was found that a leak occurred at the gas phase Ω ring one year after the original start-up. The leaking part was the shell side, and the leaking medium was the hot high-fraction gas of the reaction product, with a pressure of 17MPa and a temperature of 360℃ entering the heat exchanger. If the leak here is not discovered and handled in time, it will cause serious production safety accidents such as fire and explosion, which will pose a huge safety hazard and seriously affect the long-term stable operation of the unit.
[0004] Analysis shows that the short-term leakage of the Ω-ring sealing structure is caused by corrosion and welding defects. Due to the particularity of the Ω-ring cavity weld structure of the Ω-shaped sealing ring, no other effective flaw detection methods can be used except PT (surface non-destructive testing), and the water pressure test cannot be performed in the Ω-ring cavity. If the main sealing C-ring fails, the sulfur-containing medium enters the Ω-ring cavity with pore defects, and the leakage probability will be greatly increased. The same type of equipment in some domestic refining and chemical enterprises also has the above leakage problems, and can only be shut down for treatment in serious cases. In order to effectively monitor the operating status of the Ω-ring sealing structure and reduce the leakage probability of this part, a high-pressure heat exchanger sealing device with secondary anti-leakage function is specially designed based on actual production and operation experience. The problem of external leakage of the Ω-ring sealing structure caused by corrosion or welding defects is solved, and the equipment can be monitored and operated by online monitoring means after leakage occurs, reducing production losses. Utility Model Content
[0005] In view of the above-mentioned shortcomings of the prior art, in order to solve the leakage problem of the tube box weld and the Ω ring cavity weld of the Ω ring high-pressure heat exchanger, eliminate the leakage hidden dangers, reduce the safety production risk, and improve the stable operation rate of the device.
[0006] The utility model provides a high-pressure heat exchanger sealing device with a secondary anti-leakage function, comprising: a flange connection mechanism, the flange connection mechanism comprising a shell side flange and a tube box side flange, the shell side flange and the tube box side flange are connected by bolts;
[0007] The Ω-ring sealing assembly includes an Ω-shaped sealing ring, which is coaxially arranged between the shell side flange and the pipe box side flange;
[0008] The arc-shaped sealing ring is sleeved outside the Ω-shaped sealing ring and is located between the shell side flange and the tube box side flange. The opposite ends of the arc-shaped sealing ring are respectively sealed and matched with the shell side flange and the tube box side flange, so that a closed cavity is formed between the arc-shaped sealing ring, the Ω-shaped sealing ring, the shell side flange and the tube box side flange;
[0009] The close-packed unit comprises a pressure relief line and a valve assembly, wherein the valve assembly is arranged on the pressure relief line, one end of the pressure relief line is connected with the closed cavity, and the other end is located outside the closed cavity and connected with the close-packed outlet.
[0010] In one embodiment of the utility model, a real-time pressure monitoring unit is also included. The real-time pressure monitoring unit includes a pressure pipeline and a remote pressure gauge. One end of the pressure pipeline is connected to the closed cavity, and the other end of the pressure pipeline is located outside the closed cavity and is provided with a remote pressure gauge.
[0011] In one embodiment of the present invention, the remote pressure gauge is connected to the DSC alarm system.
[0012] In one embodiment of the utility model, one end of the pressure-leading pipeline and the pressure-relief pipeline are welded through a branch pipe and an arc-shaped sealing ring, the connection point between the pressure-leading pipeline and the closed cavity corresponds to the top of the high-pressure heat exchanger, and the connection point between the pressure-relief pipeline and the closed cavity corresponds to the bottom of the high-pressure heat exchanger.
[0013] In one embodiment of the utility model, the valve assembly of the close-packed unit includes a pressure-reducing regulating valve, a switching valve group and a shower valve. The switching valve group includes a first hand valve and a second hand valve. The pressure-reducing regulating valve and the shower valve are respectively arranged on the pressure relief pipeline between the first hand valve and the second hand valve.
[0014] In one embodiment of the utility model, the Ω-shaped sealing ring includes a pair of annular gaskets, the longitudinal cross-section of the radial inner end of each annular gasket is a rectangular surface, and the longitudinal cross-section of the radial outer end is an arc surface, the radial inner ends of the pair of annular gaskets correspond to each other, and the radial outer ends of the pair of annular gaskets are aligned and connected to form an Ω ring cavity.
[0015] In one embodiment of the utility model, each annular gasket is a metal gasket, and the radial inner ends of a pair of annular gaskets correspond to each other and fit together to form an inner annular ring. A pair of axial end faces of the inner annular ring are respectively welded to the flange sealing surfaces of the shell side flange and the pipe box side flange, and the radial outer ends of a pair of annular gaskets are matched and the outer edges are welded together to form an Ω ring cavity.
[0016] In one embodiment of the utility model, a pair of fitting surfaces corresponding to the radial inner ends of a pair of annular gaskets are a pair of sealing surfaces, one of the sealing surfaces is provided with a wire sealing groove, and a sealing ring is arranged in the wire sealing groove.
[0017] In an embodiment of the present invention, the sealing ring is a C-shaped sealing ring.
[0018] In one embodiment of the present invention, the shell side flange and the shell side shell, as well as the tube box side flange and the tube box shell are all welded with 30° flanges.
[0019] Beneficial effects of the utility model:
[0020] The utility model discloses a high-pressure heat exchanger sealing device with a secondary anti-leakage function, comprising a flange connection mechanism, an omega ring sealing assembly, an arc-shaped sealing ring and a close-packed unit. The flange connection mechanism comprises a shell side flange and a tube box side flange, and the shell side flange and the tube box side flange are connected by bolts. The omega ring sealing assembly comprises an omega-shaped sealing ring and a sealing ring, and the omega-shaped sealing ring is coaxially arranged between the shell side flange and the tube box side flange. The arc-shaped sealing ring sleeve is arranged outside the omega-shaped sealing ring, and the opposite ends of the arc-shaped sealing ring are respectively sealed and matched with the shell side flange and the tube box side flange, so that a closed cavity is formed between the arc-shaped sealing ring, the omega-shaped sealing ring, the shell side flange and the tube box side flange. The close-packed unit comprises a pressure relief pipeline, and a pressure reducing regulating valve, a switch valve group and a shower valve arranged on the pressure relief pipeline. One end of the pressure relief pipeline is connected to the closed cavity, and the other end is located outside the closed cavity and connected to the close-packed outlet. A sealing structure with four sealing barriers is formed, with a pair of sealing surfaces as the first seal, a sealing ring as the second seal, an Ω ring cavity as the third seal, and an arc-shaped sealing ring as the fourth seal. The reliability of the high-pressure heat exchanger seal is enhanced and the risk of leakage is reduced. At the same time, after the Ω ring cavity of the Ω-shaped sealing ring leaks due to corrosion or welding defects, the leaked medium can condense in the closed cavity and be discharged through the close-packed unit in real time to avoid further corrosion of the equipment and potential safety hazards. Therefore, the utility model solves the problem of external leakage of the Ω ring sealing structure caused by corrosion or welding defects, and after leakage occurs, the operation can be monitored through the real-time pressure monitoring unit, that is, online monitoring technology, to reduce production losses.
[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the utility model, and together with the specification, are used to explain the principles of the utility model. Obviously, the drawings described below are only some embodiments of the utility model, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.
[0023] In the attached picture:
[0024] Figure 1 This is a structural schematic diagram of a high-pressure heat exchanger sealing device with a secondary anti-leakage function in one embodiment of the utility model;
[0025] Figure 2 for Figure 1 Enlarged view of point A.
[0026] Among them: shell side flange 11, pipe box side flange 12, bolts 13, Ω-shaped sealing ring 21, a pair of sealing surfaces 211, Ω ring cavity 212, a pair of axial end faces 213, annular gasket 214, radial inner end 215, radial outer end 216, wire sealing groove 217, sealing ring 22, arc-shaped sealing ring 3, closed cavity 4, pressure relief pipeline 51, pressure reducing regulating valve 52, drainage valve 53, tight discharge outlet 54, pressure leading pipeline 55, remote pressure gauge 56, first hand valve 57, second hand valve 58, shell side shell 6, pipe box shell 7. DETAILED DESCRIPTION
[0027] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific implementation schemes, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or under the conditions recommended by the manufacturers.
[0028] See also Figure 1 to Figure 2. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change in the proportion relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the utility model, should still fall within the scope of the technical content disclosed by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the utility model without substantially changing the technical content.
[0029] See also Figure 1-2 In one embodiment of the utility model, the utility model provides a high-pressure heat exchanger sealing device with a secondary anti-leakage function. The high-pressure heat exchanger can be, for example, a high-pressure heat exchanger of a residue hydrocracking unit. The high-pressure heat exchanger sealing device includes a flange connection mechanism, an Ω-ring sealing assembly, an arc-shaped sealing ring 3, and a close-packed unit. The flange connection mechanism includes a shell side flange 11 and a pipe box side flange 12, and the shell side flange 11 and the pipe box side flange 12 are connected by bolts 13. The Ω-ring sealing assembly includes an Ω-shaped sealing ring 21 and a sealing ring 22, and the Ω-shaped sealing ring 21 is coaxially arranged between the shell side flange 11 and the pipe box side flange 12. The arc-shaped sealing ring 3 is sleeved outside the Ω-shaped sealing ring 21 and is located between the shell side flange 11 and the pipe box side flange 12. The opposite ends of the arc-shaped sealing ring 3 are respectively sealed and matched with the shell side flange 11 and the pipe box side flange 12, so that a closed cavity 4 is formed between the arc-shaped sealing ring 3, the Ω-shaped sealing ring 21, the shell side flange 11 and the pipe box side flange 12. The close-discharge unit includes a pressure relief pipeline 51 and a valve assembly, and the valve assembly is arranged on the pressure relief pipeline 51. One end of the pressure relief pipeline 51 is connected to the closed cavity 4, and the other end is located outside the closed cavity 4 and connected to the close-discharge outlet 54.
[0030] Therefore, in the high-pressure heat exchanger sealing device of the utility model, an arc-shaped sealing ring 3 is provided on the outer sleeve of the Ω-shaped sealing ring 21. The Ω-ring cavity 212 of the Ω-shaped sealing ring 21 is designed based on the principle of small tube bearing high pressure, and a positive use effect is obtained in the sealing structure of the high-pressure heat exchanger. The arc of the arc-shaped sealing ring 3 is generally set at 30° to 40°, so that in the high-temperature and high-pressure use environment, there is a "margin" of change as the environment changes. The arc-shaped sealing ring 3 is sleeved outside the Ω-shaped sealing ring 21, so that a closed cavity 4 is formed between the arc-shaped sealing ring 3, the Ω-shaped sealing ring 21, the shell side flange 11 and the tube box side flange 12. The reliability of the high-pressure and high-temperature heat exchanger seal is further enhanced and the risk of leakage is reduced. At the same time, when the Ω-shaped sealing ring 21 leaks due to corrosion or welding defects, the leaked medium enters the closed cavity 4. The leaked medium can be the hot high-pressure gas of the reaction product, whose pressure is 17MPa, and the temperature of the high-pressure heat exchanger is 360℃ high-temperature gas. The leaked medium can be condensed in the closed chamber 4 and discharged in real time through the close-packed units to avoid further corrosion of the equipment and potential safety hazards.
[0031] In one embodiment of the utility model, a real-time pressure monitoring unit is also included. The real-time pressure monitoring unit includes a pressure pipeline 55 and a remote pressure gauge 56. One end of the pressure pipeline 55 is connected to the closed chamber 4, and the other end of the pressure pipeline 55 is located outside the closed chamber 4 and is provided with a remote pressure gauge 56. The remote pressure gauge 56 is connected to the DSC alarm system. The remote pressure gauge 56 monitors the pressure in the closed chamber 4 in real time, and the DSC alarm system sets an alarm according to the pressure threshold.
[0032] One end of the pressure-inducing pipeline 55 and the pressure-relief pipeline 51 are welded through the branch platform and the arc-shaped sealing ring 3, and the penetration point of the pressure-relief pipeline 51 and the closed chamber 4 corresponds to the bottom of the high-pressure heat exchanger, that is, the lower end of the closed chamber 4, and the penetration point of the pressure-inducing pipeline 55 and the closed chamber 4 corresponds to the top of the high-pressure heat exchanger, that is, the upper end of the closed chamber 4. The valve assembly of the close-packed unit includes a pressure-reducing regulating valve 52, a switch valve group and a drainage valve 53. The switch valve group includes a first hand valve 57 and a second hand valve 58. The pressure-reducing regulating valve 52 and the drainage valve 53 are respectively arranged on the pressure-relief pipeline 51 between the first hand valve 57 and the second hand valve 58. The drainage valve 53 is arranged at the lowest point of the pressure-relief pipeline 51 to drain the residual liquid in the pressure-relief pipeline 51. The first hand valve 57 and the second hand valve 58 control the opening of the net pressure-relief pipeline 51. The pressure-reducing regulating valve 52 can adjust the pressure of the close-packed outlet 54 to a suitable value. Therefore, the close-packing unit not only has the function of reducing the pressure of the medium leaking into the closed chamber 4 , but also can remotely monitor the pressure in the closed chamber 4 .
[0033] In one embodiment of the utility model, the Ω-shaped sealing ring 21 includes a pair of annular gaskets 214, the longitudinal section of the radial inner end 215 of each annular gasket 214 is a rectangular surface, and the longitudinal section of the radial outer end 216 is an arc surface, the radial inner ends 215 of the pair of annular gaskets 214 are correspondingly fitted, and the radial outer ends 216 of the pair of annular gaskets 214 are matched and connected to form an Ω ring cavity 212. Each annular gasket 214 is a metal gasket, and the radial inner ends 215 of the pair of annular gaskets 214 are correspondingly fitted to form an inner annular ring, and a pair of axial end faces 213 of the inner annular ring are respectively welded to the flange sealing surfaces of the shell side flange 11 and the tube box side flange 12, and the radial outer ends 216 of the pair of annular gaskets 214 are matched, and the outer edges are welded together to form the Ω ring cavity 212. The radial inner ends 216 of the pair of annular gaskets 214 are correspondingly attached to a pair of sealing surfaces 211, one of which is provided with a wire sealing groove 217, and the sealing ring 22 is arranged in the wire sealing groove 217. The sealing ring 22 is a C-shaped sealing ring.
[0034] In one embodiment of the present invention, the shell side flange 11 and the shell side shell 6, as well as the tube box side flange 12 and the tube box shell 7 are all welded by 30° flanges. The shell side flange 11 and the tube box side flange 12 are made of 321 or 347 stainless steel.
[0035] In summary, the utility model is a high-pressure heat exchanger sealing device with a secondary anti-leakage function, in which a pair of sealing surfaces 211 are set as the first seal, the sealing ring 22 is set as the second seal, the Ω ring cavity 212 is set as the third seal, and the arc-shaped sealing ring 3 is set as the fourth seal. The four sealing barriers formed further enhance the reliability of the high-pressure and high-temperature heat exchanger seal and reduce the risk of leakage. The close-packing unit decompresses and packs the medium leaking into the closed chamber 4, and the real-time pressure monitoring unit can remotely monitor the pressure in the closed chamber 4 in real time. When the monitoring reaches or exceeds the set pressure threshold, the DSC alarm system alarms. By using the high-pressure heat exchanger sealing device of the utility model for the residue hydrocracking unit, the unplanned shutdown of the unit is effectively avoided, and it has the function of remote pressure monitoring, and at the same time has a decompression and close-packing design, with double safety guarantees. The design has a simple structure, is easy to operate and is practical.
[0036] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.
Claims
1. A high-pressure heat exchanger sealing device with secondary anti-leakage function, characterized in that: include: A flange connection mechanism, the flange connection mechanism comprising a shell side flange (11) and a tube box side flange (12), the shell side flange (11) and the tube box side flange (12) being connected by bolts (13); An Ω-ring sealing assembly, the Ω-ring sealing assembly comprising an Ω-shaped sealing ring (21), the Ω-shaped sealing ring (21) being coaxially arranged between the shell side flange (11) and the pipe box side flange (12); An arc-shaped sealing ring (3), the arc-shaped sealing ring (3) being sleeved outside the Ω-shaped sealing ring (21) and being located between the shell-side flange (11) and the tube-box side flange (12), and the opposite ends of the arc-shaped sealing ring (3) being respectively sealed and matched with the shell-side flange (11) and the tube-box side flange (12), so that a closed cavity (4) is formed between the arc-shaped sealing ring (3), the Ω-shaped sealing ring (21), the shell-side flange (11) and the tube-box side flange (12); A close-packed unit, the close-packed unit comprising a pressure relief pipeline (51) and a valve assembly, the valve assembly being arranged on the pressure relief pipeline (51), one end of the pressure relief pipeline (51) being connected to the closed chamber (4), and the other end being located outside the closed chamber (4) and connected to a close-packed outlet (54).
2. The high pressure heat exchanger sealing device according to claim 1, characterized in that: The device also comprises a real-time pressure monitoring unit, which comprises a pressure-conducting pipeline (55) and a remote pressure gauge (56). One end of the pressure-conducting pipeline (55) is connected to the closed chamber (4), and the other end of the pressure-conducting pipeline (55) is located outside the closed chamber (4) and is provided with the remote pressure gauge (56).
3. The high pressure heat exchanger sealing device according to claim 2, characterized in that: The remote pressure gauge (56) is connected to the DSC alarm system.
4. The high pressure heat exchanger sealing device according to claim 3, characterized in that: One end of the pressure-conducting pipeline (55) and the pressure-relief pipeline (51) are both welded via a branch pipe platform and the arc-shaped sealing ring (3); the connecting point between the pressure-conducting pipeline (55) and the closed chamber (4) corresponds to the top of the high-pressure heat exchanger, and the connecting point between the pressure-relief pipeline (51) and the closed chamber (4) corresponds to the bottom of the high-pressure heat exchanger.
5. The high pressure heat exchanger sealing device according to claim 4, characterized in that: The valve assembly of the close-packed unit comprises a pressure reducing regulating valve (52), a switch valve group and a shower valve (53); the switch valve group comprises a first hand valve (57) and a second hand valve (58); the pressure reducing regulating valve (52) and the shower valve (53) are respectively arranged on the pressure relief pipeline (51) between the first hand valve (57) and the second hand valve (58).
6. The high pressure heat exchanger sealing device according to claim 1, characterized in that: The Ω-shaped sealing ring (21) comprises a pair of annular gaskets (214); the longitudinal cross-section of the radial inner end (215) of each annular gasket (214) is a rectangular surface, and the longitudinal cross-section of the radial outer end (216) is an arc surface; the radial inner ends (215) of the pair of annular gaskets (214) are correspondingly fitted, and the radial outer ends (216) of the pair of annular gaskets (214) are aligned and connected to form an Ω ring cavity (212).
7. The high pressure heat exchanger sealing device according to claim 6, characterized in that: Each of the annular gaskets (214) is a metal gasket. The radial inner ends (215) of a pair of the annular gaskets (214) are correspondingly fitted to form an inner annular ring. A pair of axial end faces (213) of the inner annular ring are respectively welded to the flange sealing surfaces of the shell side flange (11) and the tube box side flange (12). The radial outer ends (216) of a pair of the annular gaskets (214) are fitted together, and the outer edges are welded together to form the Ω annular cavity (212).
8. The high pressure heat exchanger sealing device according to claim 7, characterized in that: A pair of correspondingly fitted surfaces of the radial inner ends (215) of a pair of annular gaskets (214) form a pair of sealing surfaces (211), one of the sealing surfaces being provided with a wire sealing groove (217), and a sealing ring (22) being arranged in the wire sealing groove (217).
9. The high pressure heat exchanger sealing device according to claim 8, characterized in that: The sealing ring (22) is a C-shaped sealing ring.
10. The high pressure heat exchanger sealing device according to claim 1, characterized in that: The shell side flange (11) and the shell side casing (6), as well as the tube box side flange (12) and the tube box casing (7) are all welded by 30° flanges.