MC8 series ultra-low temperature vacuum jacketed valve

Abstract

The application discloses an MC8 series ultralow-temperature vacuum jacketed valve and belongs to the technical field of valve sealing, which comprises a reducing tee, a valve body assembly, a valve clapper assembly, a support assembly, a jacketed assembly and a bellows assembly, the jacketed assembly is arranged outside the reducing tee, the valve body assembly is arranged inside the reducing tee, the valve clapper assembly is arranged in the valve body assembly, the bellows assembly is connected with the jacketed assembly, and the support assembly is arranged on the upside of the bellows assembly, and the application can be used for low-temperature medium at-253 DEG C, such as liquid hydrogen and liquid helium, wherein the vacuum bellows, the lengthened body, the multilayer heat insulation coating, the inner bellows and the connecting rod body form a vacuum jacketed structure with four layers of radiation shielding, heat transfer is reduced, the interlayer between the lengthened body and the jacketed pipe is vacuumized, convection heat transfer is reduced, the probability of gas molecule collision is reduced, the vacuum degree is controlled to be higher than 10 ‑2 Pa, convection heat transfer is reduced, and cold loss is extremely low.

Description

Technical Field

[0001] This invention relates to the field of valve sealing technology, specifically to an MC8 series cryogenic vacuum jacketed valve. Background Technology

[0002] Liquid hydrogen, as a highly efficient and storable clean energy source, shows broad development prospects in all aspects of the industrial chain. However, due to its flammable, explosive, and cryogenic characteristics—exploding when its volume content in air reaches 18%—and its extremely low liquid temperature of -253°C, it readily vaporizes and can expand to hundreds of times its liquid volume, causing significant damage to containers and valves containing liquid hydrogen. Furthermore, hydrogen molecules have extremely strong diffusion capabilities, able to pass through even the smallest gaps and some metals. Therefore, the selection and design of valves for cryogenic liquid hydrogen applications place higher demands on their design and selection.

[0003] Although the domestic materials and designs meet the low-temperature requirements, the pressure-bearing and sealing performance of the components still needs to be improved. Reducing heat loss at low temperatures has become a key aspect of the research and development and production of cryogenic valves. To this end, an MC8 series of ultra-low temperature vacuum jacketed valves has been proposed. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one object of the present invention is to provide an MC8 series cryogenic vacuum jacket valve.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An MC8 series cryogenic vacuum jacketed valve includes: a reducing tee, a valve body assembly, a valve disc assembly, a support assembly, a jacket assembly, and a bellows assembly. The jacket assembly is disposed outside the reducing tee, the valve body assembly is disposed inside the reducing tee, the valve disc assembly is disposed inside the valve body assembly, the bellows assembly is connected to the jacket assembly, and the support assembly is disposed on the upper side of the bellows assembly.

[0007] The jacket assembly includes a jacketed connector, which is connected to the interior of a reducing tee. An extension body is provided inside the jacketed connector, and multiple first connecting shafts are provided inside the extension body. Multiple V-shaped guide rings are connected to the outside of the first connecting shafts. A second connecting shaft is installed at one end of the first connecting shaft, and a third connecting shaft is installed at the other end.

[0008] The bellows assembly includes a vacuum bellows, which is connected to the end of the jacketed connector away from the reducing tee. An upper flange is installed at the other end of the vacuum bellows. A middle valve stem is installed on the third connecting shaft. An inner bellows is installed on the middle valve stem. An inner connecting flange is installed at the end of the inner bellows away from the middle valve stem.

[0009] The jacket assembly is used to create a high vacuum to reduce convective heat transfer.

[0010] Bellows assemblies are used to absorb minor deformations caused by welding and low temperatures when deformation is caused by temperature gradients, thereby eliminating thermal stress.

[0011] In one or more embodiments of the present invention, a connecting rod body is installed on the middle valve stem, a valve cover is provided on the upper flange, an inner connecting flange is installed at the connection between the valve cover and the upper flange, and metal spiral wound gaskets for sealing are provided on the upper and lower sides of the inner connecting flange.

[0012] In one or more embodiments of the present invention, a pressure cap is installed on the valve cover, a base plate is installed on the outside of the valve cover, the valve cover is fixed to the pressure cap and the base plate by a locking nut, a pressure sleeve is installed at the bottom of the pressure cap inside the valve cover, an upper packing is installed below the pressure sleeve, a plurality of middle packings are installed on the outside of the upper packings away from the pressure sleeve, a lower packing is installed on the outside of the middle packings, a packing pad is installed at the bottom of the lower packings, and the connecting rod penetrates through the outside of the pressure cap.

[0013] In one or more embodiments of the present invention, the support assembly includes two pillars, one end of which is symmetrically mounted on a base plate, and the other end of which is bolted to a support plate. One end of the connecting rod is fitted with an upper valve stem, and a connecting sleeve is fitted to the outside of the upper valve stem. A positioning piece is bolted to the bottom of the connecting sleeve, and the outside of the positioning piece is clearance-fitted with the pillar.

[0014] In one or more embodiments of the present invention, the end of the upper valve stem away from the connecting sleeve passes through the outside of the bracket plate via a valve stem nut and is equipped with a handwheel.

[0015] In one or more embodiments of the present invention, the valve body assembly includes a valve body, which is welded to one end of an extension body. The valve body has a flow channel inside, and transition pipes are installed at both ends of the valve body. End caps are installed at both ends of the reducing tee, and the transition pipes penetrate the outside of the end caps.

[0016] In one or more embodiments of the present invention, the connector assembly includes a DC channel, which is opened on the upper flange. A ferrule is installed inside the DC channel. A connecting nut is installed at one end of the ferrule through a connector. A sealing head is installed at one end of the ferrule, and one end of the sealing head is installed on the connecting nut.

[0017] In one or more embodiments of the present invention, the valve disc assembly includes a lower valve stem, the lower valve stem being mounted on a second connecting shaft, a valve disc being mounted on the end of the lower valve stem away from the second connecting shaft via a valve disc cover, a sealing ring being mounted on the outside of the valve disc, and a gasket being mounted on the bottom of the sealing ring.

[0018] Compared with the prior art, the beneficial effects of the present invention are:

[0019] This invention can be used for cryogenic media such as liquid hydrogen and liquid helium at -253°C. The vacuum bellows, extended body, multi-layer insulation, inner bellows, and connecting rod form a four-layer radiation-shielded vacuum jacket structure, reducing heat transfer. By evacuating the interlayer between the extended body and the jacket connecting pipe, convective heat transfer is reduced, decreasing the probability of gas molecule collisions. The vacuum level is controlled at 10... -2 Above Pa, it reduces convective heat transfer and has extremely low cooling loss;

[0020] In this invention, by setting an inner bellows, the packing seal can achieve a helium detection rate of 100 ppmv at low temperatures, preventing liquid hydrogen leakage and air ingress that could cause frost formation or explosion on the bellows. By setting a vacuum bellows, the deformation of the inner and outer shells caused by temperature changes is balanced and eliminated, reducing heat leakage at low temperatures, while keeping the internal medium temperature from rising and isolating it from the external environment and the heat transfer between it and the upper operating part of the upper valve stem. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the internal structure of the MC8 series cryogenic vacuum jacketed valve of the present invention;

[0022] Figure 2 This is a schematic diagram of the external three-dimensional structure of the MC8 series cryogenic vacuum jacketed valve of the present invention;

[0023] Figure 3 This is a schematic diagram of the left-side structure of the MC8 series cryogenic vacuum jacketed valve of the present invention;

[0024] Figure 4 This invention relates to the MC8 series cryogenic vacuum jacketed valve. Figure 1 An enlarged structural diagram of region C in the diagram;

[0025] Figure 5 This invention relates to the MC8 series cryogenic vacuum jacketed valve. Figure 1 A magnified structural diagram of region D in the diagram;

[0026] Figure 6 This invention relates to the MC8 series cryogenic vacuum jacketed valve. Figure 1 An enlarged structural diagram of region A in the diagram;

[0027] Figure 7 This invention relates to the MC8 series cryogenic vacuum jacketed valve. Figure 1 A magnified structural diagram of region B in the diagram.

[0028] In the diagram: 1. Valve body; 2. Valve disc; 201. Washer; 202. Sealing ring; 203. Lower valve stem; 204. Valve disc cover; 3. First connecting shaft; 301. Second connecting shaft; 302. Third connecting shaft; 4. Spiral wound metal gasket; 5. Vacuum bellows; 6. Valve cover; 7. Packing gasket; 8. Upper packing; 801. Middle packing; 802. Lower packing; 9. Pressure sleeve; 10. Pressure gland; 11. Support; 12. Locking nut; 13. Upper valve stem; 14. 15. Connecting sleeve; 16. Positioning plate; 17. Support plate; 18. Valve stem nut; 19. Handwheel; 20. Reducing tee; 21. Transition pipe; 22. Extension body; 23. V-shaped guide ring; 24. Base plate; 25. Connecting nut; 26. Connecting head; 27. Compression fitting; 28. Sealing head; 29. ​​Jacketed connecting pipe; 20. End cap; 20. Upper flange; 21. Inner bellows; 22. Inner connecting flange; 33. Middle valve stem; 34. Connecting rod body. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] Please see Figures 1-7 The present invention provides a technical solution:

[0031] An MC8 series cryogenic vacuum jacketed valve includes: a reducing tee 19, a valve body assembly, a valve disc assembly, a support assembly, a jacket assembly, and a bellows assembly. The jacket assembly is disposed on the reducing tee 19, the valve body assembly is disposed inside the reducing tee 19, the valve disc assembly is disposed inside the valve body assembly, the bellows assembly is connected to the jacket assembly, and the support assembly is disposed on the upper side of the bellows assembly.

[0032] The jacket assembly includes a jacket connector 25, which is connected to the interior of the reducing tee 19. An extension body 21 is provided inside the jacket connector 25. Multiple first connecting shafts 3 are provided inside the extension body 21. Multiple V-shaped guide rings 22 are connected to the outside of the first connecting shafts 3. A second connecting shaft 301 is installed at one end of the first connecting shaft 3, and a third connecting shaft 302 is installed at the other end.

[0033] The bellows assembly includes a vacuum bellows 5, which is connected to the end of the jacketed pipe 25 away from the reducing tee 19. The other end of the vacuum bellows 5 is fitted with an upper flange 27. A middle valve stem 30 is mounted on the third connecting shaft 302. An inner bellows 28 is mounted on the middle valve stem 30. An inner connecting flange 29 is mounted on the end of the inner bellows 28 away from the middle valve stem 30.

[0034] The jacket assembly is used to create a high vacuum to reduce convective heat transfer.

[0035] The bellows assembly is used to absorb minor deformations caused by welding and low temperature through the vacuum bellows 5 and the inner bellows 28 after deformation is caused by temperature gradient, thereby eliminating thermal stress.

[0036] Furthermore, the interior of the jacketed connector 25 and the exterior of the extended body 21 are both polished to reduce radiative heat transfer. The vacuum bellows 5, extended body 21, inner bellows 28, and connecting rod 31 form a four-layer radiation-shielded vacuum jacket structure. During installation, the gap between the vacuum bellows 5 and the jacketed connector 25 and the extended body 21 is evacuated to a vacuum state to reduce the probability of gas molecule collisions, and the vacuum degree is controlled at 10. -2 Above Pa, it reduces convective heat transfer and has extremely low cooling loss;

[0037] The V-shaped guide ring 22 is made of multi-layer PCTFE, which can keep the connecting rod 31 always aligned and divide the low-temperature medium in the vapor space into several independent non-flowing spaces, blocking the convective heat transfer channels. At the same time, since PCTFE is a high-performance plastic, it still has a certain degree of elasticity at a low temperature of -253℃. Therefore, it can adjust the changes in the fit clearance caused by the slight deformation of the metal at low temperature, avoiding the problem that the guide fit design under normal temperature conditions cannot meet the low-temperature working conditions.

[0038] The middle section of the valve stem 30 has a hollow structure, which reduces the heat conduction of the metal material.

[0039] The valve disc 2 seal adopts a metal-embedded PCTFE structure, which is an unconventional metal hard seal structure. It utilizes the elastic deformation that PCTFE can maintain at low temperatures and avoids the problem of the sealing surface deforming and failing to seal due to the grain expansion caused by the phase transformation of metal materials at low temperatures during the transformation of austenite to martensite.

[0040] By setting the inner bellows 28, a bubble-level seal can be achieved during use, preventing liquid hydrogen leakage and air ingress that could cause frost formation or explosion on the bellows. By setting the vacuum bellows 5, the deformation of the inner and outer shells caused by temperature changes is balanced and eliminated. By setting the extended body 21, the length is increased while meeting the requirements of strength and rigidity, reducing axial and radial heat leakage and reducing the cross-sectional area. The material used is 316 stainless steel. At the same time, the lower valve stem 203, the first connecting shaft 3, the connecting rod body 31, and the upper valve stem 13 are set to increase the contact thermal resistance.

[0041] Specifically, a connecting rod body 31 is installed on the middle valve stem 30, a valve cover 6 is provided on the upper flange 27, an inner connecting flange 29 is installed at the connection between the valve cover 6 and the upper flange 27, and metal spiral wound gaskets 4 for sealing are provided on the upper and lower sides of the inner connecting flange 29.

[0042] Specifically, a pressure cap 10 is installed on the valve cover 6, and a base plate 23 is installed on the outside of the valve cover 6. The valve cover 6 is fixed to the pressure cap 10 and the base plate 23 by locking nuts 12. A pressure sleeve 9 is installed at the bottom of the pressure cap 10 inside the valve cover 6. An upper packing 8 is installed below the pressure sleeve 9. Multiple middle packings 801 are installed on the outside of the upper packing 8 away from the pressure sleeve 9. A lower packing 802 is installed on the outside of the middle packings 801. A packing pad 7 is installed at the bottom of the lower packing 802. The connecting rod 31 passes through the outside of the pressure cap 10.

[0043] Among them, the upper packing 8, the middle packing 801 and the lower packing 802 are made of PTFE material, which helps to prevent the sealing effect from decreasing after the elasticity of the packing decays, prevents the medium from leaking from the top and causing accidents, and also has a lubricating effect.

[0044] Specifically, the support assembly includes two pillars 11. One end of each pillar 11 is symmetrically mounted on the base plate 23. The other end of each pillar 11 is bolted to a support plate 16. One end of the connecting rod 31 is fitted with an upper valve stem 13. A connecting sleeve 14 is mounted on the outside of the upper valve stem 13. A positioning piece 15 is bolted to the bottom of the connecting sleeve 14. The outside of the positioning piece 15 is clearance-fitted with the pillar 11.

[0045] The valve stem is divided into an upper valve stem 13 and a lower valve stem 203, which reduces the heat conduction of the mechanical mechanism of this application.

[0046] Specifically, the end of the upper valve stem 13 away from the connecting sleeve 14 passes through the valve stem nut 17 and extends to the outside of the bracket plate 16, and is equipped with a handwheel 18.

[0047] The handwheel 18 is fixedly connected to the upper valve stem 13 by bolts, and the handwheel 18 is equipped with a handle to facilitate the operator to turn it and apply force.

[0048] Specifically, the valve body assembly includes a valve body 1, which is welded to one end of an extension body 21. The valve body 1 has a flow channel inside, and transition pipes 20 are installed at both ends of the valve body 1. End caps 26 are installed at both ends of the reducing tee 19, and the transition pipes 20 penetrate the outside of the end caps 26.

[0049] The flow channel and the valve disc assembly are set at 90°. When the valve disc assembly is in contact with the flow channel, the medium can be cut off. The transition pipe 20 passes through the outside of the end cap 26 and provides a limiting function for the valve body 1. One end of the transition pipe 20 located outside the reducing tee 19 is connected to the external pipeline.

[0050] Specifically, the connector assembly includes a DC channel, which is opened on the upper flange 27. A ferrule 2402 is installed inside the DC channel. A connecting nut 24 is installed on one end of the ferrule 2402 through a connector 2401. A sealing head 2403 is installed on one end of the ferrule 2402. One end of the sealing head 2403 is installed on the connecting nut 24.

[0051] Among them, the ferrule 2402 is a hollow tube, the connector 2401 is fixed at the connection between the connecting nut 24 and the ferrule 2402, and the sealing head 2403 is spherical at one end in contact with the ferrule 2402, and the other end passes through the connecting nut 24 and extends to the outside.

[0052] Specifically, the valve disc assembly includes a lower valve stem 203, which is mounted on the second connecting shaft 301. A valve disc 2 is mounted on the end of the lower valve stem 203 away from the second connecting shaft 301 through a valve disc cover 204. A sealing ring 202 is mounted on the outside of the valve disc 2, and a gasket 201 is mounted on the bottom of the sealing ring 202.

[0053] The valve disc assembly moves up and down inside the first connecting shaft 3. The valve disc 2 uses a conical seal. The sealing ring 202 and the gasket 201 are made of reinforced PCTFE to reduce the cross-sectional size of the valve stem, reduce heat leakage, and make the valve more airtight under operating force.

[0054] Based on the above technical solution, the working steps of this solution are summarized as follows: After the transition pipe 20 is connected to the pipeline, when the medium being transported is liquid hydrogen at -253℃ and the jacketed pipe 25 is at room temperature, the valve assembly rises and the medium begins to flow. The medium rises with the first connecting shaft 3 and comes into contact with the inner bellows 28. By setting the upper packing 8, the middle packing 801 and the lower packing 802, leakage at the upper part of the medium is prevented. By setting the vacuum bellows 5, the deformation of the inner and outer shells caused by temperature changes is balanced and eliminated.

[0055] Furthermore, the heat transfer pathways are mainly divided into axial transfer and radial transfer. Axial transfer mainly refers to the heat transfer from the transition pipe 20 to the valve body 1, and then along the extension body 21 to the top of the valve stem 13. Specifically, it can be divided into axial transfer through the outer pipe of the jacketed connector 25, axial transfer through the inner rod of the upper valve stem 13, and convective transfer through the steam space outside the upper valve stem 13. Radial transfer mainly refers to the heat transfer of the medium through the inner wall of the first connecting shaft 3 to the vacuum insulation coating layer on the outer wall of the extension body 21, and then the heat transfer process is completed through the inner bellows 28 and the vacuum bellows 5.

[0056] All parts not described in this invention are the same as or can be implemented using existing technology. Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An MC8 series cryogenic vacuum jacketed valve, comprising: Reducing tee (19), valve body assembly, valve disc assembly, bracket assembly, jacket assembly, bellows assembly; The jacket assembly is located outside the reducing tee (19), the valve body assembly is located inside the reducing tee (19), the valve disc assembly is located inside the valve body assembly, the bellows assembly is connected to the jacket assembly, and the support assembly is located on the upper side of the bellows assembly. The jacket assembly is characterized in that it includes a jacket connector (25), which is connected to the interior of a reducing tee (19), and an extension body (21) is provided inside the jacket connector (25). The interior of the extended body (21) is equipped with multiple V-shaped guide rings (22) made of multilayer polytrifluoroethylene (PCTFE) through multiple first connecting shafts (3). Multiple non-flowing independent spaces are formed between the V-shaped guide rings (22) and the inner wall of the extended body (21) to block convective heat transfer. A second connecting shaft (301) for connecting the valve disc assembly is installed at one end of the multiple first connecting shafts (3), and a third connecting shaft (302) is installed at the other end. The bellows assembly includes a vacuum bellows (5) and an inner bellows (28); one end of the vacuum bellows (5) is connected to the end of the jacketed pipe (25) away from the reducing tee (19), and the other end is fitted with an upper flange (27) to form a static compensation structure for absorbing thermal deformation of the inner and outer shells; a middle valve stem (30) is mounted on the third connecting shaft (302), the inner bellows (28) is sleeved and mounted on the middle valve stem (30), and an inner connecting flange (29) is mounted on the end of the inner bellows (28) away from the middle valve stem (30), and the inner connecting flange (29) is fixed to the upper flange (27); The valve assembly includes a lower valve stem (203), which is mounted on the second connecting shaft (301). A valve disc (2) is mounted on the end of the lower valve stem (203) away from the second connecting shaft (301) through a valve disc cover (204). A sealing ring (202) is mounted on the outside of the valve disc (2), and a gasket (201) is also mounted on the bottom of the sealing ring (202). Both the sealing ring (202) and the gasket (201) are made of reinforced PCTFE material. The jacket assembly is used to draw a high vacuum to reduce convective heat transfer; the bellows assembly is used to absorb the slight deformation caused by welding and low temperature through the vacuum bellows (5) and the inner bellows (28) after deformation is caused by temperature gradient, thereby eliminating thermal stress.

2. The MC8 series cryogenic vacuum jacketed valve according to claim 1, characterized in that: A connecting rod body (31) is also installed on the middle valve stem (30), and a valve cover (6) is provided on the upper flange (27). The inner connecting flange (29) is installed at the connection between the valve cover (6) and the upper flange (27). Metal spiral wound gaskets (4) for sealing are provided on the upper and lower sides of the inner connecting flange (29).

3. The MC8 series cryogenic vacuum jacketed valve according to claim 2, characterized in that: A pressure cap (10) is installed on the valve cover (6). A base plate (23) is installed on the outside of the valve cover (6). The valve cover (6) is fixed to the pressure cap (10) and the base plate (23) by a locking nut (12). A pressure sleeve (9) is installed at the bottom of the pressure cap (10) inside the valve cover (6). An upper packing (8) is installed below the pressure sleeve (9). Multiple middle packings (801) are installed on the outside of the upper packing (8) away from the pressure sleeve (9). A lower packing (802) is installed on the outside of the middle packings (801). A packing pad (7) is installed at the bottom of the lower packing (802). The connecting rod (31) passes through the outside of the pressure cap (10).

4. The MC8 series cryogenic vacuum jacketed valve according to claim 2, characterized in that: The support assembly includes two pillars (11), one end of which is symmetrically mounted on the base plate (23), and the other end of which is bolted to a support plate (16). One end of the connecting rod (31) is fitted with an upper valve stem (13), and a connecting sleeve (14) is mounted on the outside of the upper valve stem (13). A positioning piece (15) is bolted to the bottom of the connecting sleeve (14), and the outside of the positioning piece (15) is clearance-fitted with the pillar (11).

5. The MC8 series cryogenic vacuum jacketed valve according to claim 4, characterized in that: The upper valve stem (13) is located away from the connecting sleeve (14) and passes through the outside of the bracket plate (16) via the valve stem nut (17), and is equipped with a handwheel (18).

6. The MC8 series cryogenic vacuum jacketed valve according to claim 1, characterized in that: The valve body assembly includes a valve body (1), which is welded to one end of an extension body (21). The valve body (1) has a flow channel inside. Both ends of the valve body (1) are equipped with transition pipes (20). Both ends of the reducing tee (19) are equipped with end caps (26). The transition pipes (20) penetrate the outside of the end caps (26).

7. The MC8 series cryogenic vacuum jacketed valve according to claim 1, characterized in that: It also includes a connector assembly, which includes a DC channel that is opened on the upper flange (27). A ferrule (2402) is installed inside the DC channel. A connecting nut (24) is installed on one end of the ferrule (2402) through a connector (2401). A sealing head (2403) is installed on one end of the ferrule (2402). One end of the sealing head (2403) is installed on the connecting nut (24).

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