A dynamic sealing device and method for high-temperature and high-pressure gas system

Abstract

The present invention discloses a dynamic sealing device and method for a high-temperature and high-pressure gas system, belonging to the field of dynamic sealing structure technology. The dynamic sealing device for a high-temperature and high-pressure gas system includes a connecting pipe, a transition pipe, a slip-on nut, a sealing assembly, and a compression piece. The transition pipe is connected to both ends of the connecting pipe by a slip-on nut. At the same time, the slip-on nut drives the compression piece to compress the sealing assembly to seal the connection portion between the connecting pipe and the transition pipe, so that the transition pipe and the connecting pipe form a dynamic sealing connection. The transition pipe can move axially, deflect radially, and rotate around the axis of the connecting pipe to adapt to the thermal expansion deformation caused by the high-temperature gas. Furthermore, by providing a heat insulation layer on the inner wall of the transition pipe and the connecting pipe, the device can be applied to a higher temperature gas transportation environment. The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention has a simple and compact structure, a relatively light overall weight, is easy to disassemble and assemble, and is convenient for maintenance. It can work normally under an environment of 2000°C and 10MPa.

Description

Technical Field

[0001] The present invention belongs to the technical field of dynamic sealing structures, and in particular relates to a dynamic sealing device and method for a high-temperature and high-pressure fuel gas system. Background Art

[0002] In the field of solid-state attitude control, to improve overall system performance and achieve greater impulse and thrust, high-energy solid propellants are required to generate combustion gases. These gases typically reach temperatures of 1000°C to 2000°C. These gases are then transported through pipelines to exhaust devices such as nozzles or thrusters to generate the required attitude control power. High-temperature combustion gas pipelines experience significant temperature fluctuations during operation, which can induce significant thermal stresses within the pipelines. Due to the typically complex pipeline structure, these thermal stresses are multi-dimensional, including axial, radial, and bending stresses. Without stress relief measures, these thermal stresses can lead to overstress failure. A common method for compensating for thermal deformation is bellows, but due to the limited temperature and pressure resistance of the bellows material, their maximum operating temperature does not exceed 1000°C, making them unsuitable for applications at higher temperatures and hindering further increases in combustion gas temperature. Therefore, reliably transporting these higher-temperature gases to the exhaust devices is a key factor in improving system performance. Summary of the Invention

[0003] In response to one or more of the above-mentioned defects or improvement needs in the prior art, the present invention provides a dynamic sealing device and method for a high-temperature and high-pressure gas system, which can be adjusted in the axial and radial directions and can also rotate around the axis. It can compensate for thermal expansion in all directions during gas transportation and can adapt to gas transportation at temperatures exceeding 1000°C.

[0004] To achieve the above object, the present invention provides a dynamic sealing device for a high-temperature and high-pressure gas system, which includes a connecting pipe, a transfer pipe, a slip-on nut, a sealing assembly and a pressing member;

[0005] The connecting pipe is composed of a first pipe body and a second pipe body, wherein the first pipe body and the second pipe body are both provided with a large diameter section and a small diameter section, and the ends of the two small diameter sections are butted together to form the connecting pipe which is provided with a large diameter section, a small diameter section and a large diameter section in sequence along the axis;

[0006] One end of the transfer tube is sequentially provided with a coaxial first-order hole and a second-order hole, the diameter of the first-order hole is larger than the outer diameter of the large-diameter section, the outer diameter of the large-diameter section is larger than the diameter of the second-order hole, the first-order hole is sleeved on the outside of the large-diameter section, and a sealing assembly and a pressing member are provided between the first-order hole and the large-diameter section;

[0007] The slipper nut includes a first connecting portion parallel to the axis and a second connecting portion perpendicular to the first connecting portion, wherein the inner diameter of the second connecting portion is larger than the outer diameter of the small diameter section and smaller than the outer diameter of the large diameter section, the second connecting portion is sleeved on the small diameter section, the inner side of the first connecting portion can be threadedly connected to the outer side of the first-step hole, and drives the second connecting portion to push the pressing member to press the sealing assembly, and a certain reserved space is set between the second connecting portion and the side surface opposite to the large diameter section;

[0008] The inner wall surface and end surface of the connecting pipe and the inner wall surface of the transfer pipe are all provided with a heat insulation layer to block the high-temperature gas.

[0009] As a further improvement of the present invention, a sealing groove is opened in the first-step hole, and the sealing assembly and the clamping member are installed between the inner wall of the sealing groove and the outer wall of the large diameter section. The clamping member can press the sealing assembly to the bottom of the sealing groove.

[0010] As a further improvement of the present invention, the compression degree of the sealing assembly is controlled by controlling the dimension of the compression member in a direction parallel to the axis.

[0011] As a further improvement of the present invention, a limiting portion is provided on the side of the pressing member away from the axis, and the limiting portion can abut against the end face of the first-step hole to limit its maximum pressing degree on the sealing assembly.

[0012] As a further improvement of the present invention, the sealing assembly is composed of sealing rings and gaskets spaced apart in pairs, and both ends of the sealing assembly are gaskets.

[0013] As a further improvement of the present invention, the gasket is made of brass material, and the sealing ring is made of flexible graphite material.

[0014] As a further improvement of the present invention, the connecting pipe and the transfer pipe are made of high-temperature resistant materials, and / or the thermal insulation layer is made of carbon phenolic-high silica composite winding pipe material.

[0015] As a further improvement of the present invention, the thickness of the thermal insulation layer is between 2 mm and 5 mm.

[0016] As a further improvement of the present invention, the difference between the inner diameter of the second connecting portion and the outer diameter of the small diameter section is between 0.2 and 1.0 mm;

[0017] and / or,

[0018] The reserved spacing is between 1mm and 4mm;

[0019] and / or,

[0020] The inner diameter of the large diameter section is equal to the diameter of the second-order hole.

[0021] Another aspect of the present invention provides a dynamic sealing method for a high-temperature and high-pressure gas system, comprising the following steps:

[0022] The second connecting parts of the two slipper nuts are respectively sleeved on the small diameter sections of the first tube body and the second tube body, and the openings of the first connecting parts of the slipper nuts are aligned with the openings of the corresponding large diameter sections;

[0023] butt-join the small-diameter sections of the first tube body and the second tube body to form a complete connecting tube;

[0024] Adhere the heat insulation layer to the inner wall surface and end surface of the connecting pipe and the inner wall surface of the transfer pipe;

[0025] Install the sealing assembly and the pressing piece into the first-stage hole of the transfer tube in sequence;

[0026] Insert the large diameter section into the first-stage hole where the sealing assembly and the pressing piece are installed, and screw the slip-on nut so that the inner side of the first connecting portion of the slip-on nut is threadedly connected with the outer side of the first connecting portion, while the second connecting portion of the slip-on nut pushes the pressing piece to press the sealing assembly;

[0027] The ends of the two transfer tubes that are separated from each other are respectively connected to the inlet and outlet of the gas transportation pipeline.

[0028] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0029] In general, the above technical solutions conceived by the present invention have the following beneficial effects compared with the prior art:

[0030] (1) The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention comprises a connecting pipe, a transition pipe, a slip-on nut, a sealing assembly, and a compression piece. The transition pipe is connected to both ends of the connecting pipe by a slip-on nut. At the same time, the slip-on nut drives the compression piece to compress the sealing assembly to seal the connection between the connecting pipe and the transition pipe, so that the transition pipe and the connecting pipe form a dynamic sealing connection. The transition pipe can move axially, deflect radially, and rotate around the axis of the connecting pipe to adapt to the thermal expansion deformation caused by the high-temperature gas. Furthermore, by providing a heat insulation layer on the inner wall of the transition pipe and the connecting pipe, the device can be applied to a gas transportation environment with a higher temperature. The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention has a simple and compact structure, a relatively light overall weight, is easy to disassemble and assemble, and is convenient for maintenance. Its maximum operating temperature can exceed 1000°C, and it can operate normally under an environment of 2000°C and 10MPa.

[0031] (2) The dynamic sealing device for high-temperature and high-pressure gas systems of the present invention improves the adaptability of the device to the operating temperature by optimizing the materials of the transfer tube and the connecting tube, as well as the material of the thermal insulation layer, so as to adapt to higher temperature gas transportation conditions.

[0032] (3) The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention is configured to have a sealing assembly consisting of a sealing ring and a gasket spaced apart in pairs, with both ends of the sealing assembly being provided with the gasket. The gasket can reduce the loss rate of the sealing ring, and the sealing assembly formed by the two sealing rings spaced apart in pairs can not only achieve a sealing effect but also increase the service life.

[0033] (4) The dynamic sealing method for high-temperature and high-pressure gas systems of the present invention adapts to the thermal expansion deformation caused by high-temperature gas through axial movement, radial deflection and rotation of the transfer tube. It is applicable to various working conditions. By bonding a thermal insulation layer on the inner wall of the transfer tube and the connecting pipe, it can adapt to gas transportation at a temperature exceeding 1000°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 It is a cross-sectional view of a dynamic sealing device for a high-temperature and high-pressure gas system according to an embodiment of the present invention.

[0036] In all the drawings, the same figure marks represent the same technical features, specifically: 1. Connecting pipe; 11. First tube body; 12. Second tube body; 13. Large diameter section; 14. Small diameter section; 2. Adapter tube; 21. First-step hole; 211. Sealing groove; 22. Second-step hole; 3. Loose nut; 31. First connecting part; 32. Second connecting part; 4. Sealing assembly; 41. Sealing ring; 42. Gasket; 5. Pressing piece; 51. Limiting part; 6. Thermal insulation layer. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0040] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0041] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] Example:

[0043] See also Figure 1 The dynamic sealing device for a high-temperature and high-pressure gas system in a preferred embodiment of the present invention includes a connecting pipe 1, a transfer pipe 2, a slip-on nut 3, a sealing assembly 4 and a pressing member 5.

[0044] The connecting pipe 1 is composed of a first pipe body 11 and a second pipe body 12. The first pipe body 11 and the second pipe body 12 are both provided with a large diameter section 13 and a small diameter section 14. The ends of the two small diameter sections 14 are butted together to form the connecting pipe 1 which is composed of a large diameter section 13, a small diameter section 14 and a large diameter section 13 in sequence along the axis.

[0045] One end of the transfer tube 2 is provided with a coaxial first-step hole 21 and a second-step hole 22 in sequence. The diameter of the first-step hole 21 is larger than the outer diameter of the large-diameter section 13, and the outer diameter of the large-diameter section 13 is larger than the diameter of the second-step hole 22. The first-step hole 21 is sleeved on the outside of the large-diameter section 13, and a sealing assembly 4 and a pressing part 5 are provided between the first-step hole 21 and the large-diameter section 13.

[0046] In this embodiment, the diameter of the first-step hole 21 at the end of the adapter tube 2 is larger than the outer diameter of the large-diameter section 13, and the outer diameter of the large-diameter section 13 is larger than the diameter of the second-step hole 22. Therefore, the first-step hole 21 is arranged outside the large-diameter section 13 of the connecting tube 1 and limits the axial displacement of the adapter tube 2 close to the connecting tube 1. That is, the adapter tube 2 can move axially at most to the bottom of the first-step hole 21 and abut against the end face of the large-diameter section 13, so as to prevent the sealing assembly 4 from falling off from the large-diameter section 13 and causing sealing failure.

[0047] Furthermore, the slip-on nut 3 includes a first connecting portion 31 parallel to the axis and a second connecting portion 32 perpendicular to the first connecting portion 31, the inner diameter of the second connecting portion 32 is larger than the outer diameter of the small diameter section 14 and smaller than the outer diameter of the large diameter section 13, the second connecting portion 32 is sleeved on the small diameter section 14, the inner side of the first connecting portion 31 can be threadedly connected to the outer side of the first-step hole 21, and drive the second connecting portion 32 to push the clamping member 5 to tighten the sealing assembly 4, and a certain reserved distance is set between the second connecting portion 32 and the side opposite to the large diameter section 13.

[0048] In this embodiment, the second connecting portion 32 of the slipper nut 3 can be respectively sleeved onto the two small-diameter sections 14 before the first and second tube bodies 11, 12 are joined to form the integral connecting tube 1. The first connecting portion 31 of the slipper nut 3 is threadedly connected to the outer side of the first-step hole 21 of the transition tube 2, clamping the sidewall of the first-step hole 21 and the sealing assembly 4 against the large-diameter section 13, thereby dynamically sealing the transition tube 2 against the end of the connecting tube 1. Furthermore, the inner diameter of the second connecting portion 32 of the slipper nut 3 is limited to be larger than the outer diameter of the small-diameter section 14 and smaller than the outer diameter of the large-diameter section 13, allowing the second connecting portion of the slipper nut 3 to be sleeved onto the outer side of the small-diameter section 14 without separating from the small-diameter section 14. This prevents the transition tube 2 from separating from the connecting tube 1 and limits its axial displacement away from the connecting tube 1. Specifically, the transition tube 2 can only move axially to the point where the second connecting portion 32 abuts the side opposite the large-diameter section 13. In addition, since the inner diameter of the second connecting portion 32 of the slipper nut 3 is larger than the outer diameter of the small diameter section 14 , the adapter tube 2 can deflect in the radial direction and can also drive the slipper nut 3 to rotate around the axis of the connecting tube 1 .

[0049] In actual use, the two transfer tubes 2 in the dynamic sealing device for high-temperature and high-pressure gas systems of the present invention are respectively connected to the inlet and outlet of the gas transportation pipeline. The transfer tubes 2 can adapt to the thermal expansion deformation caused by the high-temperature gas through axial movement, radial deflection and rotation.

[0050] The dynamic sealing device for high-temperature, high-pressure gas systems of the present invention is adjustable in both the axial and radial directions and can also rotate about its axis, compensating for thermal expansion in all directions during gas transportation and adapting to various operating conditions. Furthermore, the dynamic sealing device for high-temperature, high-pressure gas systems of the present invention has a simple and compact structure, weighing less than 430g, making it easy to disassemble and assemble, and facilitates maintenance.

[0051] For example, as the adapter tube 2 moves axially and radially and rotates, the contact surface between the sealing assembly 4 and the large diameter section 13 and / or the first-step hole 21 is constantly frictionally worn. As a consumable, the sealing assembly 4 needs to be regularly inspected and replaced. At this time, unscrew the threaded connection between the slip-on nut 3 and the adapter tube 2, remove the adapter tube 2 from the connecting pipe 1, and then remove the sealing assembly 4 and reinstall a new sealing assembly 4.

[0052] Further preferably, the inner wall surface and end surface of the connecting pipe 1 and the inner wall surface of the transfer pipe 2 are provided with a thermal insulation layer 6 to block the high-temperature gas to adapt to higher temperature gas transportation conditions. The maximum operating temperature can exceed 1000°C. The dynamic sealing device for high-temperature and high-pressure gas system of the present invention can work normally under 2000°C and 10MPa environment.

[0053] Preferably, the connecting pipe 1 and the transition pipe 2 are made of high-temperature resistant materials. For example, the connecting pipe 1 and the transition pipe 2 are made of 310S heat-resistant stainless steel, which has an austenite crystal structure and can withstand a high temperature of 800°C.

[0054] Preferably, the thermal insulation layer 6 is made of carbon phenolic-high silica composite winding tube material to isolate high-temperature gas; further, the thermal insulation layer 6 is bonded to the inner wall surface of the transfer tube 2 and the connecting tube 1 using D03 (L) single-component room-temperature curing organic silicone adhesive.

[0055] Preferably, the thickness of the thermal insulation layer 6 is between 2 mm and 5 mm, which can be calculated according to heat transfer theory based on gas temperature, gas flow, working time, working pressure, thermal stress parameters of the connecting pipe 1 and the transfer pipe 2, etc.

[0056] Preferably, the difference between the inner diameter of the second connecting portion 32 and the outer diameter of the small diameter section 14 is between 0.2 and 1.0 mm, which is used for radial adjustment of the gas pipeline. The difference can be calculated based on heat transfer theory based on parameters such as the total length of the pipeline, the pipeline expansion coefficient, and the operating temperature.

[0057] Preferably, the reserved spacing between the second connecting portion 32 and the side opposite to the large diameter section 13 is between 1 mm and 4 mm, which is used for axial adjustment of the gas pipeline. The specific spacing can be calculated based on heat transfer theory according to parameters such as the total length of the pipeline, the pipeline line expansion coefficient, and the operating temperature.

[0058] Preferably, the inner diameter of the large diameter section 13 is equal to the diameter of the second-order hole 22, that is, the diameters of the transfer tube 2 and the connecting tube are opposite, and the inner walls of the two can be aligned when they are connected to form a smooth gas channel.

[0059] Preferably, a sealing groove 211 is opened in the first-step hole 21, and the sealing assembly 4 and the clamping member 5 are installed between the inner wall of the sealing groove 211 and the outer wall of the large diameter section 13, and the clamping member 5 can press the sealing assembly 4 to the bottom of the sealing groove 211.

[0060] In this embodiment, the clamping piece 5 and the sealing assembly 4 are clamped between the slip-on nut 3 and the adapter tube 2. The clamping piece 5, the sealing assembly 4, the slip-on nut 3 and the adapter tube 2 form a whole and can move axially, deflect radially and rotate together.

[0061] Preferably, the degree of compression of the sealing assembly 4 is controlled by controlling the dimension of the compression member 5 in a direction parallel to the axis, that is, when the length of the compression member 5 in a direction parallel to the axis is larger, the sealing assembly 4 can be compressed more tightly.

[0062] Preferably, a limiting portion 51 is provided on the side of the pressing member 5 away from the axis, and the limiting portion 51 can abut against the end surface of the first-step hole 21 to limit its maximum pressing degree on the sealing assembly 4.

[0063] In this preferred embodiment, the limiting portion 51 can press the sealing assembly 4 tighter and tighter before abutting against the end surface of the first-step hole 21 until the limiting portion 51 abuts against the end surface of the first-step hole 21 and the degree of compression of the sealing assembly 4 reaches the maximum.

[0064] Preferably, the sealing assembly 4 is composed of sealing rings 41 and gaskets 42 spaced apart in pairs, and both ends of the sealing assembly 4 are provided with gaskets 42. The gaskets 42 can reduce the loss rate of the sealing ring 41. The sealing assembly 4 formed by the two spaced apart in pairs can not only achieve a sealing effect, but also improve the service life.

[0065] For example, the gasket 42 is made of brass material, and the sealing ring 41 is made of flexible graphite material. The maximum compression amount of the sealing assembly 4 formed by the combination of the two can reach 50%.

[0066] In actual use, the present invention also provides a dynamic sealing method for a high-temperature and high-pressure gas system, comprising the following steps:

[0067] The second connecting parts 32 of the two slipper nuts 3 are respectively sleeved on the small diameter sections 14 of the first tube body 11 and the second tube body 12, and the openings of the first connecting parts 31 of the slipper nuts 3 are aligned with the openings of the corresponding large diameter sections 13;

[0068] The first tube body 11 and the small diameter section 14 of the second tube body 12 are butt-connected to form an integral connecting tube 1;

[0069] Bonding the heat insulation layer 6 to the inner wall surface and end surface of the connecting pipe 1 and the inner wall surface of the transfer pipe 2;

[0070] Install the sealing assembly 4 and the pressing member 5 into the first-stage hole 21 of the transfer tube 2 in sequence;

[0071] Insert the large-diameter section 13 into the first-step hole 21 in which the sealing assembly 4 and the pressing member 5 are installed, and screw the slip-on nut 3 so that the inner side of the first connecting portion 31 of the slip-on nut 3 is threadedly connected with the outer side of the first-step hole 21. At the same time, the second connecting portion 32 of the slip-on nut 3 pushes the pressing member 5 to press the sealing assembly 4.

[0072] The ends of the two transfer tubes 2 that are separated from each other are respectively connected to the inlet and outlet of the gas transportation pipeline.

[0073] In the dynamic sealing method of this embodiment, the above steps are not necessarily performed in sequence. For example, the thermal insulation layer 6 can also be bonded to the inner walls and ends of the first tube body 11 and the second tube body 12 before the first tube body 11 and the second tube body 12 are connected; in addition, the sealing assembly 4 and the clamping member 5 can also be first sleeved on the outside of the large diameter section 13 and then inserted into the first-step hole 21 together with the large diameter section 13.

[0074] The dynamic sealing method for high-temperature and high-pressure gas systems of the present invention adapts to the thermal expansion deformation caused by high-temperature gas through axial movement, radial deflection and rotation of the transfer tube 2. It is applicable to various working conditions. By bonding an insulation layer on the inner wall of the transfer tube and the connecting pipe, it can adapt to gas transportation with a temperature exceeding 1000°C.

[0075] The present invention relates to a dynamic sealing device for a high-temperature, high-pressure gas system, comprising a connecting pipe 1, a transition pipe 2, a slip-on nut 3, a sealing assembly 4, and a compression member 5. The transition pipe 2 is connected to both ends of the connecting pipe 1 via the slip-on nut 3. The slip-on nut 3 simultaneously drives the compression member 5 to compress the sealing assembly 4 and seal the connection between the connecting pipe 1 and the transition pipe 2, thereby forming a dynamic seal connection between the transition pipe 2 and the connecting pipe 1. The transition pipe 2 can move axially along the connecting pipe 1, deflect radially, and rotate about its axis to accommodate thermal expansion deformation caused by the high-temperature gas. Furthermore, by providing a thermal insulation layer 6 on the inner walls of the transition pipe 2 and the connecting pipe 1, the device is suitable for use in gas transportation environments at higher temperatures. The present invention relates to a dynamic sealing device for a high-temperature, high-pressure gas system, having a simple and compact structure, a relatively light overall weight, and easy assembly and disassembly, thereby facilitating maintenance. Its maximum operating temperature can exceed 1000°C and it can operate normally in an environment of 2000°C and 10 MPa.

[0076] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dynamic sealing device for a high-temperature and high-pressure gas system, characterized in that: Including connecting pipe, transfer pipe, slip-on nut, sealing assembly and compression piece; The connecting pipe is composed of a first pipe body and a second pipe body, wherein the first pipe body and the second pipe body are both provided with a large diameter section and a small diameter section, and the ends of the two small diameter sections are butted together to form the connecting pipe which is provided with a large diameter section, a small diameter section and a large diameter section in sequence along the axis; One end of the transfer tube is sequentially provided with a coaxial first-order hole and a second-order hole, the diameter of the first-order hole is larger than the outer diameter of the large-diameter section, the outer diameter of the large-diameter section is larger than the diameter of the second-order hole, the first-order hole is sleeved on the outside of the large-diameter section, and a sealing assembly and a pressing member are provided between the first-order hole and the large-diameter section; The slipper nut includes a first connecting portion parallel to the axis and a second connecting portion perpendicular to the first connecting portion, wherein the inner diameter of the second connecting portion is larger than the outer diameter of the small diameter section and smaller than the outer diameter of the large diameter section, the second connecting portion is sleeved on the small diameter section, the inner side of the first connecting portion can be threadedly connected to the outer side of the first-step hole, and drives the second connecting portion to push the pressing member to press the sealing assembly, and a certain reserved space is set between the second connecting portion and the side surface opposite to the large diameter section; The inner wall surface and end surface of the connecting pipe and the inner wall surface of the transfer pipe are all provided with a heat insulation layer to block the high-temperature gas.

2. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 1, characterized in that: A sealing groove is provided in the first-stage hole. The sealing assembly and the pressing member are installed between the inner wall of the sealing groove and the outer wall of the large-diameter section. The pressing member can press the sealing assembly against the bottom of the sealing groove.

3. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 2, characterized in that: The compression degree of the sealing assembly is controlled by controlling the dimension of the compression member in a direction parallel to the axis.

4. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 2, characterized in that: A limiting portion is provided on the side of the pressing member away from the axis, and the limiting portion can abut against the end surface of the first-step hole to limit the maximum degree of compression of the sealing assembly.

5. The dynamic sealing device for a high-temperature and high-pressure gas system according to any one of claims 1 to 4, characterized in that: The sealing assembly is composed of sealing rings and gaskets spaced apart in pairs, and both ends of the sealing assembly are provided with the gaskets.

6. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 5, characterized in that: The gasket is made of brass material, and the sealing ring is made of flexible graphite material.

7. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 1, characterized in that: The connecting pipe and the transfer pipe are made of high-temperature resistant materials, and / or the heat insulation layer is made of carbon phenolic-high silica composite winding pipe material.

8. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 1, characterized in that: The thickness of the heat insulation layer is between 2 mm and 5 mm.

9. The dynamic sealing device for a high-temperature and high-pressure gas system according to claim 1, characterized in that: The difference between the inner diameter of the second connecting portion and the outer diameter of the small-diameter section is between 0.2 and 1.0 mm; and / or, The reserved spacing is between 1mm and 4mm; and / or, The inner diameter of the large diameter section is equal to the diameter of the second-order hole.

10. A dynamic sealing method for a high-temperature and high-pressure gas system, characterized in that: The method is implemented by applying the dynamic sealing device for a high-temperature and high-pressure gas system according to any one of claims 1 to 9, comprising the following steps: The second connecting parts of the two slipper nuts are respectively sleeved on the small diameter sections of the first tube body and the second tube body, and the openings of the first connecting parts of the slipper nuts are aligned with the openings of the corresponding large diameter sections; butt-join the small-diameter sections of the first tube body and the second tube body to form a complete connecting tube; Adhere the heat insulation layer to the inner wall surface and end surface of the connecting pipe and the inner wall surface of the transfer pipe; Install the sealing assembly and the pressing piece into the first-stage hole of the transfer tube in sequence; Insert the large diameter section into the first-stage hole where the sealing assembly and the pressing piece are installed, and screw the slip-on nut so that the inner side of the first connecting portion of the slip-on nut is threadedly connected with the outer side of the first connecting portion, while the second connecting portion of the slip-on nut pushes the pressing piece to press the sealing assembly; The ends of the two transfer tubes that are separated from each other are respectively connected to the inlet and outlet of the gas transportation pipeline.

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