Dynamic sealing device and method for high-temperature and high-pressure gas system

Abstract

The invention discloses a dynamic sealing device and method for a high-temperature and high-pressure gas system, and belongs to the technical field of dynamic sealing structures. The dynamic sealing device for the high-temperature and high-pressure fuel gas system comprises a connecting pipe, adapter pipes, loop nuts, a sealing assembly and a pressing piece, the adapter pipes are connected to the two ends of the connecting pipe through the loop nuts, and meanwhile the loop nuts drive the pressing piece to press the sealing assembly to seal the connecting portion of the connecting pipe and the adapter pipes. The adapter pipe and the connecting pipe form dynamic sealing connection, and the adapter pipe can move in the axial direction of the connecting pipe, deflect in the radial direction and rotate around the axis so as to adapt to thermal expansion deformation caused by high-temperature fuel gas. Furthermore, heat insulation layers are arranged on the inner walls of the adapter pipe and the connecting pipe, so that the device can be suitable for a higher-temperature fuel gas transportation environment. The dynamic sealing device for the high-temperature and high-pressure fuel gas system is simple and compact in structure, light in overall mass, convenient to disassemble and assemble, convenient to maintain and capable of normally working under the environment of 2000 DEG C and 10 MPa.

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 attitude control, in order to improve the overall performance of the system and obtain greater impulse and thrust, high-energy solid propellants are needed to generate combustion gas. The combustion gas temperature can usually reach 1000℃~2000℃. The combustion gas is transported to exhaust devices such as nozzles or thrusters through pipelines to generate the required attitude control power. The temperature of the high-temperature combustion gas transmission pipeline changes greatly during operation. The temperature change will form a large thermal stress on the pipeline. Since the pipeline structure is usually complex, the direction of thermal stress on the pipeline is multi-dimensional, with both axial stress and radial stress, as well as bending stress. If stress release measures are not taken for the thermal stress of the pipeline, it will cause overstress damage to the pipeline. The commonly used thermal deformation compensation method is bellows, but it is limited by the limited temperature and pressure resistance of the bellows material. Its maximum operating temperature does not exceed 1000℃, which is difficult to adapt to higher temperature applications, making it difficult to further increase the gas temperature. Therefore, how to reliably transport higher temperature combustion gas to the exhaust device has become one of the key factors in improving the working performance of the system. 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 the thermal expansion in all directions during the gas transportation process and can adapt to the gas transportation at a temperature 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 piece; The connecting pipe is composed of a first pipe body and a second pipe body, 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 sequentially a large diameter section, a small diameter section and a large diameter section along the axis; One end of the conversion tube is provided with a coaxial first-order hole and a second-order hole in sequence, 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 outer side 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 slip-on nut comprises a first connection portion parallel to the axis and a second connection portion perpendicular to the first connection portion, the inner diameter of the second connection 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 connection portion is sleeved on the small diameter section, the inner side of the first connection portion can be threadedly connected to the outer side of the first-stage hole, and drives the second connection portion to push the pressing member to press the sealing assembly, and a certain reserved spacing is set between the second connection portion and the side surface opposite to the large diameter section; The inner wall surface and end surface of the connecting tube and the inner wall surface of the conversion tube are all provided with a heat insulation layer to block the high-temperature combustion gas.

[0005] As a further improvement of the present invention, a sealing groove is opened in the first-order 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 against the bottom of the sealing groove.

[0006] 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 axial line.

[0007] 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 surface of the first-step hole to limit its maximum pressing degree on the sealing assembly.

[0008] 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.

[0009] 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.

[0010] As a further improvement of the present invention, the connecting tube and the conversion tube are made of high temperature resistant material, and / or the heat insulation layer is made of carbon phenolic-high silica composite winding tube material.

[0011] As a further improvement of the present invention, the thickness of the thermal insulation layer is between 2 mm and 5 mm.

[0012] 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; and / or, The reserved spacing is between 1 mm and 4 mm; and / or, The inner diameter of the large diameter section is equal to the diameter of the second-order hole.

[0013] Another aspect of the present invention provides a dynamic sealing method for a high-temperature and high-pressure gas system, comprising the following steps: The second connection parts of the two slip-on 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 connection parts of the slip-on nuts are all oriented in the same direction as the openings of the corresponding large diameter sections; The small diameter sections of the first pipe body and the second pipe body are butt-jointed to form a complete connecting pipe; Bonding 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 equipped with the sealing assembly and the pressing piece, and screw the slip-on nut so that the inner side of the first connection part of the slip-on nut is threadedly connected with the outer side of the first connection part, and at the same time, the second connection part of the slip-on nut pushes the pressing piece to press the sealing assembly; The ends of the two transfer tubes which are separated from each other are respectively connected to the inlet and outlet of the gas transportation pipeline.

[0014] The above-mentioned improved technical features can be combined with each other as long as they do not conflict with each other.

[0015] In general, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects: (1) The dynamic sealing device for 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 pressing 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 pressing piece to press 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 along the axial direction of the connecting pipe, deflect radially and rotate around the axis to adapt to the thermal expansion deformation caused by the high-temperature gas. Further, by arranging 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 high-temperature and high-pressure gas system of the present invention has a simple and compact structure, a light overall weight, is easy to disassemble and assemble, and is easy to maintain. Its maximum working temperature can exceed 1000°C, and it can work normally under an environment of 2000°C and 10MPa.

[0016] (2) The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention improves the adaptability of the device to the operating temperature by optimizing the materials of the conversion 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.

[0017] (3) The dynamic sealing device for a high-temperature and high-pressure gas system of the present invention is configured such that the sealing assembly is composed of a sealing ring and a gasket spaced apart in pairs, and both ends of the sealing assembly are provided with the gasket. The gasket can reduce the wear rate of the sealing ring. 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.

[0018] (4) The dynamic sealing method for a high-temperature and high-pressure gas system of the present invention adapts to the thermal expansion deformation caused by high-temperature gas through axial movement, radial deflection and rotation of the conversion tube, and is applicable to a variety of working conditions. By bonding a heat insulation layer on the inner wall of the conversion tube and the connecting tube, it can adapt to the transportation of gas at a temperature exceeding 1000°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. 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.

[0020] Figure 1 It is a cross-sectional view of a dynamic sealing device for a high-temperature and high-pressure gas system in an embodiment of the present invention.

[0021] 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. slip-on nut; 31. first connecting part; 32. second connecting part; 4. sealing assembly; 41. sealing ring; 42. gasket; 5. clamping piece; 51. limiting part; 6. thermal insulation layer. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain 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 can be combined with each other as long as they do not conflict with each other.

[0023] 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 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, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0025] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0027] Example: 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.

[0028] 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. One end of the transfer tube 2 is provided with a coaxial first-order hole 21 and a second-order hole 22 in sequence, the diameter of the first-order hole 21 is larger than the outer diameter of the large diameter section 13, the outer diameter of the large diameter section 13 is larger than the diameter of the second-order hole 22, the first-order hole 21 is sleeved on the outside of the large diameter section 13, and a sealing assembly 4 and a clamping member 5 are provided between the first-order hole 21 and the large diameter section 13.

[0029] 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, so that the first-step hole 21 is sleeved on the outside of the large-diameter section 13 of the connecting tube 1 and limits the displacement of the adapter tube 2 axially 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.

[0030] 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 piece 5 to clamp the sealing assembly 4, and a certain reserved spacing is set between the second connecting portion 32 and the side opposite to the large diameter section 13.

[0031] In this embodiment, the second connection part 32 of the slipper nut 3 can be respectively sleeved on the two small diameter sections 14 before the first tube body 11 and the second tube body 12 are butt-jointed to form the integral connecting tube 1. The first connection part 31 of the slipper nut 3 is threadedly connected with the outer side of the first-step hole 21 of the transition tube 2, and the side wall of the first-step hole 21 and the sealing assembly 4 are clamped on the large diameter section 13, so that the transition tube 2 is dynamically sealed at the end of the connecting tube 1. Further, the inner diameter of the second connection part 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, so that the second connection part of the slipper nut 3 can be sleeved on the outer side of the small diameter section 14 and will not be separated from the small diameter section 14, so as to prevent the transition tube 2 from being separated from the connecting tube 1 and limit the displacement of the transition tube 2 away from the connecting tube 1 in the axial direction, that is, the transition tube 2 can move in the axial direction at most to the side opposite to the large diameter section 13 where the second connection part 32 abuts. In addition, since the inner diameter of the second connecting portion 32 of the slip-on nut 3 is larger than the outer diameter of the small-diameter section 14 , the adapter tube 2 can deflect in the radial direction to a certain extent and can also drive the slip-on nut 3 to rotate around the axis of the connecting tube 1 .

[0032] In actual use, the two transfer tubes 2 in the dynamic sealing device for the high-temperature and high-pressure gas system 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. The dynamic sealing device for high-temperature and high-pressure gas systems of the present invention can be adjusted in the axial and radial directions, and can also rotate around the axis, and can compensate for the thermal expansion in all directions during the gas transportation process, and adapt to various working conditions. In addition, the dynamic sealing device for high-temperature and high-pressure gas systems of the present invention has a simple and compact structure, and the overall mass can be as low as 430g or less, and is easy to disassemble and assemble, and is easy to maintain.

[0033] For example, as the adapter tube 2 moves axially and radially and rotates, the contact surfaces between the sealing assembly 4 and the large diameter section 13 and / or the first-step hole 21 are constantly worn out by friction. 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.

[0034] Further preferably, the inner wall surface and end surface of the connecting pipe 1 and the inner wall surface of the transfer tube 2 are provided with a heat insulation layer 6 to block the high-temperature fuel gas to adapt to higher temperature fuel gas transportation conditions. The maximum operating temperature can exceed 1000°C. The dynamic sealing device for high-temperature and high-pressure fuel gas system of the present invention can work normally under 2000°C and 10MPa environment.

[0035] Preferably, the connecting pipe 1 and the transition pipe 2 are made of high temperature resistant materials. Exemplarily, 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.

[0036] Preferably, the thermal insulation layer 6 is made of carbon phenolic-high silica composite winding tube material to isolate high-temperature fuel gas; further, the thermal insulation layer 6 is bonded to the inner wall surfaces of the transfer tube 2 and the connecting tube 1 using D03 (L) single-component room-temperature curing organic silicone adhesive.

[0037] 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.

[0038] 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 according to parameters such as the total length of the pipeline, the expansion coefficient of the pipeline line, and the operating temperature.

[0039] 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. It can be specifically calculated according to heat transfer theory based on parameters such as the total length of the pipeline, the expansion coefficient of the pipeline line, and the operating temperature.

[0040] 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 passage.

[0041] Preferably, a sealing groove 211 is opened in the first-step hole 21, and the sealing assembly 4 and the clamping piece 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 piece 5 can press the sealing assembly 4 to the bottom of the sealing groove 211.

[0042] 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.

[0043] Preferably, the compression degree of the sealing assembly 4 is controlled by controlling the dimension of the compression member 5 in a direction parallel to the axial line, that is, when the length of the compression member 5 in a direction parallel to the axial line is larger, the sealing assembly 4 can be compressed more tightly.

[0044] Preferably, a limiting portion 51 is provided on a side of the pressing member 5 away from the axis, and the limiting portion 51 can abut against an end surface of the first-step hole 21 to limit its maximum pressing degree on the sealing assembly 4 .

[0045] 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 sealing assembly 4 is pressed to the maximum.

[0046] 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 the gaskets 42. The gaskets 42 can reduce the wear rate of the sealing rings 41. The sealing assembly 4 formed by the two spaced apart in pairs can not only achieve a sealing effect, but also increase the service life.

[0047] Exemplarily, 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%.

[0048] 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: The second connection 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 connection parts 31 of the slipper nuts 3 are all in the same direction as the openings of the corresponding large diameter sections 13; 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; 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; Install the sealing assembly 4 and the pressing piece 5 into the first-stage hole 21 of the transfer tube 2 in sequence; Insert the large diameter section 13 into the first-step hole 21 equipped with the sealing assembly 4 and the pressing piece 5, and screw the slip-on nut 3 so that the inner side of the first connection portion 31 of the slip-on nut 3 is threadedly connected with the outer side of the first-step hole 21, and at the same time, the second connection portion 32 of the slip-on nut 3 pushes the pressing piece 5 to press the sealing assembly 4; 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.

[0049] 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 piece 5 can also be firstly 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.

[0050] 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 conversion tube, and is suitable for a variety of working conditions. By bonding a thermal insulation layer on the inner wall of the conversion tube and the connecting tube, it can adapt to gas transportation with a temperature exceeding 1000°C.

[0051] The dynamic sealing device for high-temperature and high-pressure gas system of the present invention comprises a connecting pipe 1, a transition pipe 2, a slip-on nut 3, a sealing assembly 4 and a pressing piece 5. The transition pipe 2 is connected to both ends of the connecting pipe 1 by the slip-on nut 3. At the same time, the slip-on nut 3 drives the pressing piece 5 to press the sealing assembly 4 to seal the connection part between the connecting pipe 1 and the transition pipe 2, so that the transition pipe 2 forms a dynamic sealing connection with the connecting pipe 1. The transition pipe 2 can move along the axial direction of the connecting pipe 1, deflect radially and rotate around the axis to adapt to the thermal expansion deformation caused by the high-temperature gas; further, by arranging a heat insulation layer 6 on the inner wall of the transition pipe 2 and the connecting pipe 1, the device can be applied to a higher temperature gas transportation environment. The dynamic sealing device for high-temperature and high-pressure gas system of the present invention has a simple and compact structure, a light overall weight, is easy to disassemble and assemble, and is easy to maintain. Its maximum working temperature can exceed 1000°C, and it can work normally under an environment of 2000°C and 10MPa.

[0052] It will be easily understood by those skilled in the art that the above description is only 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 protection scope of the present invention.

Claims

1. A dynamic sealing device for a high-temperature and high-pressure gas system, characterized in that: It includes a connecting pipe, a transfer pipe, a slip-on nut, a sealing assembly and a pressing piece; The connecting pipe is composed of a first pipe body and a second pipe body, 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 sequentially a large diameter section, a small diameter section and a large diameter section along the axis; One end of the conversion tube is provided with a coaxial first-order hole and a second-order hole in sequence, 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 outer side 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 slip-on nut comprises a first connection portion parallel to the axis and a second connection portion perpendicular to the first connection portion, the inner diameter of the second connection 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 connection portion is sleeved on the small diameter section, the inner side of the first connection portion can be threadedly connected to the outer side of the first-step hole, and drives the second connection portion to push the pressing member to press the sealing assembly, and a certain reserved spacing is set between the second connection portion and the side surface opposite to the large diameter section; The inner wall surface and end surface of the connecting tube and the inner wall surface of the conversion tube are all provided with a heat insulation layer to block the high-temperature combustion 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, and 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 axial line.

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 pressing on 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 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 tube and the conversion tube are made of high temperature resistant materials, and / or the heat insulation layer is made of carbon phenolic-high silica composite winding tube 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 1 mm and 4 mm; 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 steps include: The second connection parts of the two slip-on 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 connection parts of the slip-on nuts are all oriented in the same direction as the openings of the corresponding large diameter sections; The small diameter sections of the first pipe body and the second pipe body are butt-jointed to form a complete connecting pipe; Bonding 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 equipped with the sealing assembly and the pressing piece, and screw the slip-on nut so that the inner side of the first connection part of the slip-on nut is threadedly connected with the outer side of the first connection part, and at the same time, the second connection part of the slip-on nut pushes the pressing piece to press the sealing assembly; The ends of the two transfer tubes which are separated from each other are respectively connected to the inlet and outlet of the gas transportation pipeline.

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