Preparation and vacuum sealing method of low-heat-leakage helium tank

Abstract

The invention discloses a low-heat-leakage helium tank preparation and vacuum sealing method, and relates to the technical field of low-temperature liquid, and the method comprises the following steps: S1, uniformly winding a glass tape fully coated with room-temperature cured epoxy resin at the bottom of a threaded end of a G10 cylinder, uniformly winding the glass tape to an oblique angle step along a thread, and sealing the glass tape to obtain a G10 cylinder; s2, the glass tape is coated with room-temperature curing epoxy resin, the stainless steel cylinder is connected to the G10 cylinder along the threads, and the room-temperature curing epoxy resin mixed with glass fiber chippings is poured into a gap between the stainless steel cylinder and the G10 cylinder till the gap is in a full-filling state; the annular outer diameter of the sealing reinforcing ring is the same as the maximum outer diameter of the nested part of the stainless steel cylinder body; according to the preparation and vacuum sealing method of the low-heat-leakage helium tank, the G10 cylinder is introduced into the helium tank structure, the insulating material has excellent heat insulation performance and mechanical strength under the low-temperature condition, heat leakage of the helium tank is greatly reduced, and loss of liquid helium is effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of cryogenic liquids, and in particular to a method for preparing a low-leakage thermal helium tank and vacuum sealing the same. Background Art

[0002] Superconducting materials are widely used in high-field magnets, superconducting energy storage, large particle colliders, superconducting magnetic resonance and other fields due to their excellent properties such as high current density and high upper critical field under low temperature conditions. However, the critical temperature of traditional superconducting materials generally does not exceed 23K, so superconducting materials need to be immersed in liquid hydrogen or liquid helium to achieve the superconducting state. Since the temperature of liquid hydrogen is higher than that of liquid helium and it is explosive, liquid helium has become the preferred coolant for cooling superconducting magnets due to its lower temperature and safety.

[0003] In addition to the field of superconductivity, liquid helium has also been widely used in fields that require ultra-low temperature environments, such as large scientific instruments, semiconductor production, and medical equipment. Liquid helium is usually stored in a liquid helium dewar, but due to the extremely low temperature, low latent heat, and strong volatility of liquid helium, the long-term storage of liquid helium has always been a technical problem. Therefore, when designing a liquid helium dewar, sealing performance becomes a key consideration, which directly affects the storage efficiency and use cost of liquid helium. Chinese patent application number CN221035234 U discloses a liquid helium container, which partially solves the inconvenience of movement and stability caused by the large temperature difference between the outer wall of the liquid helium container and the air. However, the liquid helium container does not fully consider the problem of sealing performance. If the sealing performance of the container is insufficient, the liquid helium will exchange heat with the external environment through the container, resulting in rapid volatilization of the liquid helium, resulting in a waste of resources. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing a low-leakage hot helium tank and its vacuum sealing, so as to solve the problems existing in the prior art.

[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing a low-leakage thermal helium tank and its vacuum sealing, the method comprising: S1. Evenly wind a glass ribbon coated with room temperature curing epoxy resin around the bottom of the threaded end of the G10 cylinder, and evenly wind the glass ribbon along the thread to the bevel step; S2. Coat room temperature curing epoxy resin on the glass ribbon, connect the stainless steel cylinder to the G10 cylinder along the thread, and pour room temperature curing epoxy resin mixed with glass fiber scraps into the gap between the stainless steel cylinder and the G10 cylinder until it is filled; S3. Insert a sealing reinforcement ring from the other end of the G10 cylinder. The outer diameter of the sealing reinforcement ring is the same as the maximum outer diameter of the stainless steel cylinder at the nesting point. S4. Wrap a glass ribbon coated with room temperature curing epoxy resin around the joint between the sealing reinforcement ring and the stainless steel cylinder, and pour room temperature curing epoxy resin mixed with glass fiber chips into the gap between the sealing reinforcement ring and the G10 cylinder; S5. Allow the room temperature curing epoxy resin to completely cure by standing for more than 12 hours, thereby achieving vacuum sealing of the low leakage thermal helium tank.

[0006] Preferably, the G10 cylinder is made of insulating structural material of low-temperature superconducting magnets.

[0007] Preferably, the glass ribbon is made of alkali-free aluminoborosilicate glass fiber.

[0008] Preferably, the room temperature curing epoxy resin is subjected to a vacuum treatment before use, with a vacuum degree of 7.2×10²Pa to remove internal bubbles and improve the sealing effect.

[0009] Preferably, when the stainless steel cylinder is threadedly connected to the G10 cylinder, the room temperature curing epoxy resin is squeezed out from the thread into the provided overflow groove to form a primary seal.

[0010] Preferably, the sealing reinforcement ring enhances the overall sealing performance and low-temperature mechanical strength of the helium tank by multiple sealing with the stainless steel cylinder and the G10 cylinder.

[0011] Preferably, the outer diameter of the sealing reinforcement ring is the same as the maximum outer diameter of the stainless steel cylinder at the nesting point to ensure the sealing consistency after installation.

[0012] Preferably, the glass ribbon wrapped around the joint between the sealing reinforcement ring and the stainless steel cylinder has a width of 25 mm and a thickness of about 0.5 mm.

[0013] Preferably, glass fiber crumbs are mixed into the room temperature curing epoxy resin poured into the gap between the sealing reinforcement ring and the G10 cylinder, and are slightly stirred after pouring to prevent bubble formation.

[0014] Preferably, the sealing performance of the low-leakage hot helium tank is verified by a helium mass spectrometer leak detector, and the vacuum degree during the leak detection reaches 3.9 Pa, and the background leakage rate is about 2.1 Pa·m³ / s.

[0015] It can be seen from the above technical solution that the present invention has the following beneficial effects: The low-leakage heat helium tank preparation and vacuum sealing method thereof, by introducing a G10 cylinder into the helium tank structure, this insulating material has excellent insulation performance and mechanical strength under low temperature conditions, and compared with traditional stainless steel materials, it greatly reduces the heat leakage of the helium tank and effectively reduces the loss of liquid helium. Glass ribbons and glass fiber scraps coated with room temperature curing epoxy resin are used to achieve multiple seals in the connection area between the G10 cylinder and the stainless steel cylinder and the installation position of the sealing reinforcement ring. The multiple sealing design ensures the vacuum sealing performance of the helium tank and improves the low temperature strength of the structure. The room temperature curing epoxy resin is vacuumed before use to effectively remove internal bubbles, further improve the stability of the sealing performance, and avoid sealing defects caused by bubbles. The design of the sealing reinforcement ring matches the outer diameter of the stainless steel cylinder to ensure the integrity of the sealing structure after installation and avoid sealing failure caused by inconsistent dimensions. During the sealing process, the epoxy resin overflow groove is set to effectively accommodate excess epoxy resin, ensure the integrity of the initial seal at the threaded connection, and simplify the construction process. The G10 material and glass fiber products used in the present invention have low temperature resistance and high strength characteristics , ensuring the stability and reliability of the helium tank in an extremely low temperature environment. Through multiple sealing designs and leak detection verifications, it is confirmed that the sealing performance of the helium tank in a vacuum environment reaches 3.9Pa vacuum, and the background leakage rate is about 2.1Pa·m³ / s, without obvious fluctuations, meeting the stringent requirements for liquid helium storage and application. By improving the helium tank structure and sealing method, the volatilization loss of liquid helium is greatly reduced, providing reliable technical support for the efficient storage of liquid helium, which is suitable for the superconducting field and other low-temperature liquid storage scenarios. Compared with traditional designs, the present invention improves the insulation performance and service life of the helium tank by improving materials and optimizing the sealing process, reducing liquid helium consumption and operating costs, and bringing economic benefits to users. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of the method of the present invention; Figure 2 It is a schematic diagram of the overall structure of the present invention; Figure 3 This is a schematic diagram of the sealing area of ​​the present invention; Figure 4 This is a schematic diagram of the G10 cylinder structure of the present invention; Figure 5 This is a schematic diagram of the sealing process of the present invention; Figure 6 It is a schematic diagram of sealing completion of the present invention.

[0017] In the figure: 1. stainless steel cylinder; 101. stainless steel upper cylinder; 102. stainless steel lower cylinder; 2. G10 cylinder; 3. flange; 4. sealing reinforcement ring; 5. sealing area; 6. primary sealing area; 7. room temperature curing epoxy resin overflow groove; 8. secondary sealing area; 9. tertiary sealing area; 10. quaternary sealing area; 11. angled step. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] like Figure 1 As shown, a method for preparing a low-leakage thermal helium tank and vacuum sealing thereof, the method comprising: A glass ribbon coated with room temperature curing epoxy resin is evenly wound around the bottom of the threaded end of the G10 cylinder 2, and the glass ribbon is evenly wound along the thread to the bevel step 11; Coat the glass ribbon with room temperature curing epoxy resin, connect the stainless steel cylinder 1 to the G10 cylinder 2 along the thread, and pour the room temperature curing epoxy resin mixed with glass fiber scraps into the gap between the stainless steel cylinder 1 and the G10 cylinder 2 until it is filled; Insert the sealing reinforcement ring 4 from the other end of the G10 cylinder 2, the outer diameter of the sealing reinforcement ring is the same as the maximum outer diameter of the stainless steel cylinder 1 at the nesting point; A glass ribbon coated with room temperature curing epoxy resin is wound around the joint between the sealing reinforcement ring 4 and the stainless steel cylinder 1, and room temperature curing epoxy resin mixed with glass fiber scraps is poured into the gap between the sealing reinforcement ring 4 and the G10 cylinder 2; Allow to stand for more than 12 hours to allow the room temperature curing epoxy resin to fully cure, thereby achieving vacuum sealing of the low leakage thermal helium tank.

[0020] The present invention minimizes heat leakage and gas penetration by adopting a multi-level, multi-material combination vacuum sealing technology. After curing, the epoxy resin forms a high-strength, high-sealing filling layer, which is combined with the glass ribbon to enhance the interface bonding force and avoid the thermal expansion mismatch caused by the temperature difference. The threaded connection between the stainless steel cylinder 1 and the G10 cylinder 2 provides a preliminary mechanical seal, and the epoxy resin is filled to further prevent gas leakage in the tiny gap. The sealing reinforcement ring 4 cooperates with the multi-layer epoxy resin structure to form a superimposed sealing effect, ensuring the mechanical strength and low heat leakage performance of the overall structure. In addition, the glass fiber crumbs are mixed when the epoxy resin is poured to improve the viscosity and uniformity of the filling material, effectively avoid the generation of bubbles and enhance the crack resistance of the cured layer. The present invention significantly reduces heat leakage: the use of multiple sealing technologies reduces the heat loss of the helium tank, greatly prolongs the operating time of the low-temperature superconducting magnet, and saves helium resources. Improve the sealing reliability: the multi-layer structure design enables the seal to show excellent stability and durability in a low-temperature environment, avoiding sealing failure caused by temperature fluctuations. Improve overall strength: The seal reinforcement ring provides additional mechanical support at key locations, optimizes the seal system's ability to resist deformation, and improves structural rigidity in a vacuum environment. Reduce manufacturing complexity: The present invention avoids the complex high-temperature curing process by using room-temperature curing epoxy resin, making the operation simple and efficient.

[0021] The G10 cylinder 2 uses the insulating structural material of low-temperature superconducting magnets to ensure excellent insulation performance and mechanical stability under low temperature conditions. The G10 material is made of glass fiber reinforced epoxy resin, which has high strength, low thermal conductivity and good dielectric properties. It can still maintain an extremely low thermal expansion coefficient at low temperatures, thereby avoiding stress concentration caused by temperature differences. As an insulating material, G10 can also prevent current leakage and improve the safety of superconducting magnet operation. G10 still exhibits excellent mechanical strength and dimensional stability at liquid helium temperature, effectively avoiding thermal stress damage. As an insulating material dedicated to low-temperature superconducting magnets, G10 has excellent dielectric constant and high voltage resistance. Even under long-term operation and repeated temperature cycles, the G10 material still maintains reliable performance, thereby extending the service life of the helium tank.

[0022] Glass ribbon is made of alkali-free aluminoborosilicate glass fiber, which has excellent mechanical strength and low temperature resistance. With its unique chemical composition and manufacturing process, alkali-free aluminoborosilicate glass fiber shows high flexibility and mechanical strength in low temperature environment. The amorphous structure of this material can effectively resist crack propagation and prevent material fracture caused by stress concentration. In addition, its good compatibility with epoxy resin ensures a stable interface bonding during the curing process, enhancing the overall sealing effect.

[0023] The room temperature curing epoxy resin is vacuumed before use with a vacuum degree of 7.2×10²Pa to remove internal bubbles and improve the sealing effect. The sealing performance of epoxy resin is easily reduced due to the presence of internal bubbles during the curing process. Through vacuum treatment, the bubbles and dissolved gases in the epoxy resin can be discharged, thereby reducing the porosity in the cured material and significantly improving the sealing quality. Vacuum treatment also enhances the fluidity of the epoxy resin, making it easier to penetrate into the gaps and ensuring that every interface can be evenly covered. After removing the bubbles in the epoxy resin, its cured layer is denser, significantly reducing the risk of micro-leakage. Vacuum treatment improves the viscosity control ability of the epoxy resin and ensures a uniform thickness of the sealing layer. There are no bubbles in the sealing area to avoid local stress concentration and seal damage caused by bubble rupture.

[0024] When the stainless steel cylinder 1 is threadedly connected to the G10 cylinder 2, the room temperature curing epoxy resin is squeezed out from the thread into the overflow groove 7 to form a primary seal. During the threaded connection process, the epoxy resin is evenly distributed in the thread gap as a sealing medium. When the stainless steel cylinder 1 and the G10 cylinder 2 are tightened, the epoxy resin is pressed into the gap as the thread torque increases, and some excess epoxy resin is squeezed into the overflow groove 7. The overflow groove not only collects excess epoxy resin, but also provides external support for the primary seal after it solidifies. After solidification, the epoxy resin in the overflow groove becomes an additional sealing barrier, enhancing the stability of the primary seal. Excess epoxy resin is effectively collected to avoid waste, while increasing the reliability of the sealing structure. A dedicated overflow groove is set to control the extrusion range of the epoxy resin and keep other components clean.

[0025] The sealing reinforcement ring 4 enhances the overall sealing performance and low-temperature mechanical strength of the helium tank by multiple sealing with the stainless steel cylinder 1 and the G10 cylinder 2. As the core supporting component of the connection area, the sealing reinforcement ring 4 forms a superimposed sealing structure through reasonable nesting and epoxy resin bonding. Multi-layer sealing ensures that even in extremely low temperature or high pressure environments, when any sealing layer fails, other sealing layers can still provide protection. At the same time, as a mechanical support component, the sealing reinforcement ring 4 evenly distributes the stress of the sealing area 5 to prevent sealing failure caused by local deformation. Through multiple sealing designs, the reliability and durability of the overall sealing system of the helium tank are greatly improved. The sealing reinforcement ring 4 maintains high mechanical strength in extremely low temperature environments to ensure the stability of the helium tank. The multiple sealing structure disperses the stress concentration at the joints and extends the service life of the seal.

[0026] The outer diameter of the sealing reinforcement ring 4 is the same as the maximum outer diameter of the nesting area of ​​the stainless steel cylinder 1 to ensure the consistency of the seal after installation. The outer diameter of the sealing reinforcement ring 4 is consistent with the maximum outer diameter of the nesting area of ​​the stainless steel cylinder 1, which can provide precise mechanical fit. Such a design can ensure that there will be no loosening or displacement during the installation process, while forming a seamless nesting connection between the sealing reinforcement ring and the surrounding components to avoid uneven gaps or stress concentration at the interface. By precisely controlling the outer diameter size, the fit and airtightness of each sealing link are ensured. Sealing reinforcement rings with consistent outer diameters can remain stable in low temperature environments and will not cause sealing failure due to thermal expansion and contraction. Standardized size design reduces tolerance requirements during production and assembly, and improves manufacturing efficiency.

[0027] The width of the glass ribbon wrapped around the joint between the sealing reinforcement ring 4 and the stainless steel cylinder 1 is 25 mm, and the thickness of the wrapping is about 0.5 mm. The 25 mm wide glass ribbon can cover a larger area of ​​the joint area and effectively disperse the stress at the joint. The wrapping thickness of about 0.5 mm can provide sufficient sealing layer strength while maintaining good adhesion and flexibility, and avoid uneven curing of epoxy resin caused by excessive thickness. Such a configuration ensures the stability of the sealing area when subjected to external forces. The width and thickness design of the glass ribbon optimizes the sealing effect at the joint and prevents gas leakage. Appropriate thickness and width can improve the shear strength and tensile strength of the joint and reduce the risk of deformation. Standardized ribbon width and thickness facilitate large-scale production and quality control.

[0028] Glass fiber crumbs are mixed into the room temperature curing epoxy resin poured into the gap between the sealing reinforcement ring 4 and the G10 cylinder 2, and are slightly stirred after pouring to prevent bubble formation. The epoxy resin mixed with glass fiber crumbs has higher viscosity and filling capacity, and can provide additional support and bonding effects during the curing process. Slight stirring avoids sealing defects caused by bubble rupture or uneven curing by evenly distributing the glass fiber crumbs and expelling bubbles. The addition of glass fiber crumbs improves the strength and toughness of the epoxy resin, while reducing the shrinkage effect during the curing process. Slight stirring can significantly reduce the bubble generation rate and improve the density and stability of the sealing area. By improving the bonding force and mechanical strength, the service life of the helium tank is significantly extended.

[0029] The sealing performance of the low-leakage thermal helium tank is verified by a helium mass spectrometer leak detector. The vacuum degree during leak detection reaches 3.9Pa, and the background leak rate is about 2.1Pa·m³ / s. The helium mass spectrometer leak detector evaluates the sealing performance by detecting the leakage of trace helium. The vacuum degree of 3.9Pa ensures the high sensitivity of the detection environment. The background leak rate of 2.1Pa·m³ / s represents the minimum detection limit of the detection system, which can accurately reflect the actual sealing effect of the helium tank. The use of a helium mass spectrometer leak detector can quickly and accurately judge the sealing quality and find tiny leaks. Through strict leak detection standards, it is ensured that each helium tank meets the design requirements. Leak detection verification can effectively improve the reliability and market competitiveness of products.

[0030] The low heat leakage helium tank has excellent mechanical properties and sealing properties, and can significantly reduce radiation heat transfer with the liquid helium outer dewar, thereby reducing the loss of liquid helium.

[0031] like Figure 2-Figure 6 As shown, the helium tank includes a stainless steel upper cylinder 101, a stainless steel lower cylinder 102, a G10 cylinder 2, a flange 3 and a sealing reinforcement ring 4. The stainless steel upper cylinder 101 and the stainless steel lower cylinder 102 are connected to the G10 cylinder 2 by threads; the sealing reinforcement ring 4 connects the stainless steel upper cylinder 101, the stainless steel lower cylinder 102 and the G10 cylinder 2 to achieve multiple sealing.

[0032] Compared with ordinary helium tanks, the low heat leakage helium tank has a G10 cylinder 2. Since the G10 material has better insulation and mechanical properties than stainless steel in low temperature environments, the helium tank of the present invention greatly reduces heat leakage compared with traditional stainless steel helium tanks.

[0033] Compared with ordinary helium tanks, the low heat leakage helium tank is added with glass ribbons and glass fiber scraps coated with room temperature curing epoxy resin. The glass ribbons and glass fiber scraps are made of alkali-free, aluminum borosilicate glass fibers, which have high heat resistance, low moisture absorption, softness, high tensile strength, and good insulation performance. In the present invention, the glass ribbons and glass fiber scraps coated with room temperature curing epoxy resin are added to the helium tank to improve the mechanical properties and sealing properties of the helium tank.

[0034] The room temperature curing epoxy resin for sealing is a high-performance instant-drying product with uniform black color distribution and no stratification. There are many specifications and types of room temperature curing epoxy resin products, and it has a good bonding effect on metals, rubbers, and plastics. The room temperature curing epoxy resin needs to be placed in a container and vacuumed (vacuum degree is about 7.2×10 2 Pa), so that the air and bubbles inside it can be discharged as much as possible.

[0035] The connection area between the stainless steel upper cylinder 101 , the stainless steel lower cylinder 102 and the G10 cylinder 2 is a sealing area, and this sealing area 5 can achieve multiple sealing of the stainless steel upper cylinder 101 , the stainless steel lower cylinder 102 and the G10 cylinder 2 .

[0036] Specifically, first, the glass ribbon coated with room temperature curing epoxy resin is evenly wrapped around the bottom of the G10 cylinder 2 threaded end; Specifically, the glass ribbon is evenly wound along the thread of the G10 cylinder 2 to the bevel step 11, and after the winding is completed, the glass ribbon is fully coated with room temperature curing epoxy resin.

[0037] Specifically, the stainless steel upper cylinder 101 is screwed onto the G10 cylinder 2 along the thread. After tightening, the room temperature curing epoxy resin mixed with glass fiber debris is poured into the gap between the stainless steel upper cylinder 101 and the G10 cylinder 2 until it is filled; at the same time, part of the room temperature curing epoxy resin on the glass ribbon at the thread is squeezed into the room temperature curing epoxy resin overflow groove 7.

[0038] Specifically, a sealing reinforcement ring 4 is inserted from the other end of the G10 cylinder 2, and the outer diameter of the ring is the same as the maximum outer diameter of the stainless steel upper cylinder 101 at the nesting point; during the insertion process, the sealing reinforcement ring 4 is aligned with the stainless steel upper cylinder 101.

[0039] Specifically, a glass ribbon coated with room temperature curing epoxy resin is wound around the joint between the sealing reinforcement ring 4 and the stainless steel upper cylinder 101; the glass ribbon is 25 mm wide and about 0.5 mm thick; Specifically, a sufficient amount of room temperature curing epoxy resin mixed with glass fiber crumbs is poured into the gap between the sealing reinforcement ring 4 and the G10 cylinder 2, wherein the room temperature curing epoxy resin needs to be gently stirred to prevent air bubbles from entering and affecting the sealing performance; finally, it is left to stand for more than 12 hours to wait for the room temperature curing epoxy resin to solidify.

[0040] The helium tank after preparation and sealing of the present invention includes the process of infusing room temperature curing epoxy resin mixed with glass fiber scraps; The sealing area enables the sealing performance and mechanical properties of the helium tank at low temperatures to reach the optimal state.

[0041] The flange 3 is connected to the liquid helium external dewar through fittings.

[0042] The seal between the stainless steel lower cylinder 102 and the G10 cylinder 2 is the same as the seal between the stainless steel upper cylinder 101 and the G10 cylinder 2. Finally, the sealing performance of the helium tank is verified by connecting the test assembly to a helium mass spectrometer leak detector, turning on the leak detector, and waiting for the vacuum degree to reach 3.9 Pa. The background leak rate is about 2.1 Pa×m 3 / s, helium is sprayed along the joints of the test piece. During the leak detection, there is no obvious fluctuation in the leak rate at the leak detector, which indicates that the test piece can maintain the vacuum sealing requirement at room temperature.

[0043] The vacuum sealing method proposed in the present invention can significantly improve the sealing performance and low-temperature strength of the helium tank, and greatly reduce the heat leakage between the liquid helium and the external dewar, so as to reduce the loss of liquid helium.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a low-leakage thermal helium tank and its vacuum sealing, characterized in that: The method comprises: S1. Evenly wind a glass ribbon coated with room temperature curing epoxy resin around the bottom of the threaded end of the G10 cylinder, and evenly wind the glass ribbon along the thread to the bevel step; S2. Coat room temperature curing epoxy resin on the glass ribbon, connect the stainless steel cylinder to the G10 cylinder along the thread, and pour room temperature curing epoxy resin mixed with glass fiber scraps into the gap between the stainless steel cylinder and the G10 cylinder until it is filled; S3. Insert a sealing reinforcement ring from the other end of the G10 cylinder. The outer diameter of the sealing reinforcement ring is the same as the maximum outer diameter of the stainless steel cylinder at the nesting point. S4. Wrap a glass ribbon coated with room temperature curing epoxy resin around the joint between the sealing reinforcement ring and the stainless steel cylinder, and pour room temperature curing epoxy resin mixed with glass fiber chips into the gap between the sealing reinforcement ring and the G10 cylinder; S5. Allow the room temperature curing epoxy resin to completely cure by standing for more than 12 hours, thereby achieving vacuum sealing of the low leakage thermal helium tank.

2. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The G10 cylinder body is made of insulating structural material of low-temperature superconducting magnets.

3. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The glass ribbon is made of alkali-free aluminoborosilicate glass fiber.

4. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The room temperature curing epoxy resin is subjected to a vacuum treatment before use, with a vacuum degree of 7.2×10²Pa, so as to remove internal bubbles and improve the sealing effect.

5. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: When the stainless steel cylinder is threadedly connected with the G10 cylinder, the room temperature curing epoxy resin is squeezed out from the thread into the provided overflow groove to form a primary seal.

6. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The sealing reinforcement ring enhances the overall sealing performance and low-temperature mechanical strength of the helium tank by multiple sealing with the stainless steel cylinder and the G10 cylinder.

7. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The outer diameter of the sealing reinforcement ring is the same as the maximum outer diameter of the stainless steel cylinder at the nesting point to ensure the sealing consistency after installation.

8. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The glass ribbon wrapped around the joint between the sealing reinforcement ring and the stainless steel cylinder has a width of 25 mm and a thickness of about 0.5 mm.

9. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: Glass fiber chips are mixed into the room temperature curing epoxy resin poured into the gap between the sealing reinforcement ring and the G10 cylinder, and are slightly stirred after pouring to prevent the formation of bubbles.

10. A method for preparing a low-leakage thermal helium tank and vacuum sealing thereof according to claim 1, characterized in that: The sealing performance of the low-leakage hot helium tank is verified by a helium mass spectrometer leak detector, during which the vacuum degree reaches 3.9 Pa and the background leakage rate is about 2.1 Pa·m³ / s.

Images