An integrated maintenance and helium make-up device for a superconducting magnet system

Abstract

This invention discloses an integrated maintenance and helium replenishment device for a superconducting magnet system, relating to the field of cryogenic superconducting magnet system technology. The device includes a Dewar shell top plate, at least one quick-change mechanism for a cryostat, and at least one safe helium replenishment mechanism. By integrating at least one quick-change mechanism and at least one safe helium replenishment mechanism onto the same Dewar shell top plate and arranging them at intervals along the circumference, it replaces the traditional dispersed and independent installation method, significantly improving the utilization rate of the Dewar top space. Simultaneously, each cooling component is independently thermally connected to the cold shield. When the cold head of one quick-change mechanism fails, the remaining quick-change mechanisms can still maintain the low temperature of the cold shield, achieving redundancy backup capability. Furthermore, the safe helium replenishment mechanism is connected to the helium chamber through an installation cylinder and uses a heating box, airflow control components, and a gas duct to heat and control the helium replenishment gas flow.

Description

Technical Field

[0001] This invention relates to the field of cryogenic superconducting magnet system technology, and in particular to an integrated maintenance and helium replenishment device for a superconducting magnet system. Background Technology

[0002] In cryogenic superconducting magnet systems, to maintain the required cryogenic operating environment for the superconducting coils, a single-stage cold head is typically used to cool the cold shield, while a multi-stage cold head is used to cool both the cold shield and the liquid helium chamber. Simultaneously, liquid helium needs to be periodically replenished into the liquid helium chamber immersing the superconducting coils through a helium replenishment port to compensate for liquid helium evaporation losses during long-term operation. In existing technologies, the refrigerator's mounting interface and the helium replenishment port are usually independent and distributed on the Dewar shell. For the refrigerator interface, traditional solutions often use rigid bolts to directly fix the refrigerator cold head to the cold shield end plate. This connection method requires rewarming, degassing, or even destructive disassembly for replacement in case of refrigerator failure, resulting in maintenance cycles exceeding one week. For the helium replenishment port, in traditional solutions, the release of cryogenic helium when the plug is opened can easily cause water vapor to condense into ice, clogging the helium replenishment tube and affecting the continuity of helium replenishment. While some improvements have been implemented to address these individual problems, most of these improvements are limited to optimizing the individual interface itself.

[0003] In existing technologies, the aforementioned improvement schemes still follow the traditional layout of installing the refrigerator interface and the helium replenishment port independently. In practical engineering applications, this independent and decentralized layout suffers from limited space on top of the Dewar shell, requiring multiple independent installation interfaces to reserve their own maintenance and operation areas, resulting in a loose overall structure and low space utilization. Furthermore, when the system needs to be configured with multiple refrigerators, the lack of collaborative design between the refrigerator modules makes it difficult for other refrigerators to maintain the system's low temperature in the event of a single refrigerator failure, and it is also difficult to achieve functional coupling with the helium replenishment operation. Summary of the Invention

[0004] This invention provides an integrated maintenance and helium replenishment device for superconducting magnet systems, which can solve the problems of low top space utilization, lack of redundancy backup capability, and difficulty in collaborative work between modules caused by the independent and dispersed layout of the refrigerator interface and helium replenishment port in the existing superconducting magnet system.

[0005] An integrated maintenance and helium replenishment device for a superconducting magnet system includes a Dewar shell top plate, at least one quick-change mechanism for a refrigerator, and at least one safe helium replenishment mechanism. The Dewar shell top plate is fixedly installed on top of the superconducting magnet Dewar. At least one quick-change mechanism for a refrigerator is installed on the Dewar shell top plate. At least one safe helium replenishment mechanism is installed on the Dewar shell top plate. The quick-change mechanism for a refrigerator includes a vacuum isolation flange, a bellows, and a cooling conductor. The vacuum isolation flange is sealed to the Dewar shell top plate, and the bellows is sleeved on the cooling conductor of the refrigerator. The outer side and lower end of the head are connected to the cooling conductor, which is used for thermal connection with the cold screen located inside the superconducting magnet Dewar; the safe helium replenishment mechanism includes a mounting cylinder, a heating box, and an airflow control assembly. The mounting cylinder passes through the top plate of the Dewar shell and its lower end is connected to the helium cavity inside the superconducting magnet Dewar. The heating box is connected to the inside of the mounting cylinder through a gas guide pipe. The airflow control assembly is used to control the opening and closing of the gas guide pipe; at least one of the quick-change mechanisms for the refrigerator and at least one of the safe helium replenishment mechanisms are arranged at intervals along the circumferential direction on the top plate of the Dewar shell.

[0006] The present invention provides an integrated maintenance and helium replenishment device for a superconducting magnet system, which, compared with the prior art, has, but is not limited to, the following beneficial effects: The integrated maintenance and helium replenishment device for this superconducting magnet system integrates at least one quick-change mechanism for a cryostat and at least one safe helium replenishment mechanism, which are installed together on the same Dewar shell top plate and spaced apart along the circumference. This replaces the traditional decentralized and independent installation method, significantly improving the utilization of the Dewar top space. At the same time, each cooling component is independently thermally connected to the cold shield. When the cold head of the cryostat corresponding to one quick-change mechanism fails, the remaining quick-change mechanisms can still maintain the low temperature of the cold shield, achieving redundancy backup capability. In addition, the safe helium replenishment mechanism is connected to the helium chamber through the mounting cylinder and uses a heating box, airflow control components, and gas duct to heat and control the helium replenishment gas flow.

[0007] Furthermore, the quick-change mechanism for the refrigeration unit also includes a flexible cooling belt, and the cooling component is flexibly heat-conductingly connected to the cold shield via the flexible cooling belt.

[0008] Furthermore, the quick-change mechanism for the refrigeration unit also includes an elastic pre-tightening component, which is disposed on the side of the cooling guide component facing away from the refrigeration unit's cold head, and is used to apply a pre-tightening force toward the refrigeration unit's cold head to the cooling guide component.

[0009] Furthermore, the elastic preload assembly includes no fewer than eight compression springs, each of which is evenly distributed along the circumference of the cooling guide.

[0010] Furthermore, the safety helium replenishment mechanism also includes a helium replenishment tube and a stopper assembly, wherein the helium replenishment tube is disposed inside the mounting cylinder and the stopper assembly is disposed at the upper port of the helium replenishment tube.

[0011] Furthermore, the safety helium replenishment mechanism also includes a linkage mechanism, one end of which is connected to the plug assembly and the other end of which is connected to the airflow control assembly, so that when the plug assembly is disengaged from the helium replenishment tube, the airflow control assembly is triggered to open the gas delivery tube.

[0012] Furthermore, the safety helium replenishment mechanism also includes an airflow guide hood, which is fitted outside the mounting cylinder and located below the heating box, and the airflow guide hood is connected to the air outlet of the heating box.

[0013] Furthermore, an annular rotating air box is rotatably connected to the air outlet of the heating box, and multiple inclined discharge holes with the same inclination direction are provided through the inner side wall of the rotating air box. Multiple guide vanes are provided on the outer circumferential side of the airflow guide shroud.

[0014] Furthermore, the helium replenishment fitting includes a first helium replenishment tube and a second helium replenishment tube, the length of the first helium replenishment tube being greater than the length of the second helium replenishment tube; the plug assembly includes a plug body, the bottom of the plug body being provided with a long rod, and the long rod being provided with multiple cryogenic baffles axially upward.

[0015] Furthermore, it also includes a central controller, which is electrically connected to the status detection sensors of each refrigeration unit's quick-change mechanism and the heating element in the heating box of the safety helium replenishment mechanism. Attached Figure Description

[0016] Figure 1 A schematic diagram of the integrated maintenance and helium replenishment device for a superconducting magnet system according to an embodiment of the present invention; Figure 2 Cross-sectional view of an integrated maintenance and helium replenishment device for a superconducting magnet system according to an embodiment of the present invention. Figure 1 ; Figure 3 Cross-sectional view of an integrated maintenance and helium replenishment device for a superconducting magnet system according to an embodiment of the present invention. Figure 2 ; Figure 4 for Figure 1 A schematic diagram of the quick-change mechanism for the refrigeration unit; Figure 5 for Figure 1 Cross-sectional view of the quick-change mechanism for the refrigeration unit; Figure 6 for Figure 1 A schematic diagram of the structure of the safe helium replenishment mechanism; Figure 7 for Figure 1Cross-sectional view of the central safety helium replenishment mechanism; Figure 8 for Figure 7 A schematic diagram of the airflow guide shroud.

[0017] Explanation of reference numerals in the attached figures: 1. Dewar outer shell top plate; 2. Superconducting magnet Dewar; 3. Quick-change mechanism for the refrigerator; 31. Vacuum isolation flange; 32. Bellows; 33. Cooling conductor; 34. Flexible cooling strip; 35. Elastic pre-tightening assembly; 351. Compression spring; 4. Cold shield; 5. Safety helium replenishment mechanism; 51. Mounting cylinder; 52. Helium replenishment fittings; 521. First helium replenishment tube; 522. Second helium replenishment tube; 53. Plug assembly; 531. Plug body; 532. 533. Long rod; 54. Low temperature baffle; 55. Heating box; 56. Heating element; 57. Airflow control assembly; 58. Drive rod; 59. Drive cylinder; 50. Rotary disk; 50. Linkage mechanism; 51. Lifting plate; 52. Return spring; 53. Threaded sleeve; 54. Air guide pipe; 55. Airflow guide hood; 56. Guide vane; 57. Rotary air box; 58. Inclined discharge hole; 59. Refrigeration unit cold head; 50. Main controller. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms, indicating that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or primary / secondary relationship. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. It should also be noted that...

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] like Figure 1-6As shown in the figure, an integrated maintenance and helium replenishment device for a superconducting magnet system provided by an embodiment of the present invention includes a Dewar shell top plate 1, at least one quick-change mechanism for a refrigerator 3, and at least one safe helium replenishment mechanism 5; the Dewar shell top plate 1 is fixedly installed on the top of the superconducting magnet Dewar 2; at least one quick-change mechanism for a refrigerator 3 is installed on the Dewar shell top plate 1; at least one safe helium replenishment mechanism 5 is installed on the Dewar shell top plate 1; the quick-change mechanism for a refrigerator 3 includes a vacuum isolation flange 31, a bellows 32, and a cooling conductor 33, the vacuum isolation flange 31 is sealed to the Dewar shell top plate 1, and the bellows 32 is fitted with a... Located outside the cold head 6 of the refrigerator and connected at its lower end to the cooling conductor 33, the cooling conductor 33 is used for thermal connection with the cold screen 4 located inside the superconducting magnet Dewar 2; the safety helium replenishment mechanism 5 includes an installation cylinder 51, a heating box 54 and an airflow control component 56. The installation cylinder 51 passes through the top plate 1 of the Dewar shell and its lower end is connected to the helium cavity inside the superconducting magnet Dewar 2. The heating box 54 is connected to the interior of the installation cylinder 51 through a gas guide pipe 58. The airflow control component 56 is used to control the opening and closing of the gas guide pipe 58; at least one refrigerator quick-change mechanism 3 and at least one safety helium replenishment mechanism 5 are arranged at intervals along the circumferential direction on the top plate 1 of the Dewar shell.

[0024] In this embodiment, by integrating at least one quick-change mechanism 3 for refrigerators and at least one safe helium replenishment mechanism 5 onto the same Dewar shell top plate 1 and arranging them at intervals along the circumference, the traditional dispersed and independent installation method is replaced, which significantly improves the utilization rate of the top space of the Dewar and solves the problem of structural looseness caused by independent and dispersed layout. At the same time, each quick-change mechanism 3 for refrigerators includes a vacuum isolation flange 31, a bellows 32 and a cold conductive component 33. Each cold conductive component 33 is independently thermally connected to the cold screen 4. When the cold head 6 of the refrigerator corresponding to one quick-change mechanism 3 fails, the remaining quick-change mechanisms 3 for refrigerators can still maintain the low temperature of the cold screen 4, realizing redundancy backup capability and solving the defect of system shutdown caused by single point failure. In addition, the safe helium replenishment mechanism 5 is connected to the helium cavity through the mounting cylinder 51 and uses the heating box 54, the airflow control component 56 and the gas guide pipe 58 to heat and control the helium replenishment gas flow.

[0025] Specifically, each of the quick-change mechanisms 3 for the refrigeration units includes a vacuum isolation flange 31, a bellows 32, and a cooling conductor 33. Each cooling conductor 33 is independently and thermally connected to the cold screen 4, forming a redundant backup architecture for multiple refrigeration units. Traditional conductive cooling superconducting magnet cold heads are difficult to maintain and operate, and have poor assembly and maintainability. However, in this invention, when the cold head 6 of one of the quick-change mechanisms 3 fails, the other quick-change mechanisms 3 can still maintain the low temperature of the cold screen 4, achieving refrigeration unit replacement without shutting down the system. This eliminates the need for destructive disassembly, reheating, or demagnetization of the Dewar system, significantly reducing the maintenance cycle of more than a week required by traditional solutions, and significantly reducing system downtime and maintenance costs. At the same time, the vacuum isolation flange 31 is sealed to the top plate 1 of the Dewar shell, and the bellows 32 is sleeved on the refrigeration unit. The outer side of the cold head 6 ensures that the vacuum state of the cavity where the cold screen 4 is located is not disrupted when the cold head 6 is disassembled and replaced, thus solving the problem of system-wide vacuum disruption caused by the rigid connection of the refrigerator in the prior art. In addition, the safety helium replenishment mechanism 5 is connected to the helium cavity through the mounting cylinder 51. It uses the heating box 54, the airflow control component 56 and the gas guide pipe 58 to heat and control the helium replenishment airflow. Since it shares the same Dewar shell top plate 1 with at least one refrigerator quick replacement mechanism 3 and is arranged at intervals, the three form an integrated collaborative platform. When the helium replenishment operation is started, the heating box 54 works and generates an additional heat load. This heat load is transferred to the cold screen 4 area through the mounting cylinder 51 and the Dewar shell top plate 1. The refrigerator cold head 6, which is in normal operation, can bear this part of the heat load and maintain the temperature stability of the cold screen 4.

[0026] like Figure 4 and Figure 5 As shown, the quick-change mechanism 3 for the refrigeration unit also includes a flexible cooling belt 34, and the cooling component 33 is flexibly heat-conductingly connected to the cold screen 4 through the flexible cooling belt 34.

[0027] In this embodiment, the flexible cooling guide strip 34 is made of multiple high-purity copper laminated strips or braided strips, distributed circumferentially along the cooling guide component 33. It has good bending deformation capability. When the cooling guide component 33 adaptively adjusts its posture to match the end face of the refrigeration unit cold head 6 under the drive of the elastic pre-tightening component 35, the angular deflection, parallelism error and horizontal positional offset generated by the cooling guide component 33 can be absorbed by the flexible deformation of the flexible cooling guide strip 34. This avoids the introduction of additional assembly stress to the refrigeration unit cold head 6 or cold screen 4 due to the forced rigid connection. At the same time, the flexible cooling guide strip 34 maintains a sufficient heat conduction cross-sectional area to ensure that the cold energy is efficiently transferred from the cooling guide component 33 to the cold screen 4. Thus, under the premise of achieving planar adaptive adjustment and gapless fit of the cooling guide component 33, the independent cooling performance of each refrigeration unit quick replacement mechanism 3 in the multi-refrigeration unit redundant architecture is not affected by assembly deviation.

[0028] like Figure 4 and Figure 5As shown, the quick-change mechanism 3 for the refrigeration unit also includes an elastic pre-tightening component 35, which is disposed on the side of the cooling guide 33 facing away from the refrigeration unit cold head 6, and is used to apply a pre-tightening force toward the refrigeration unit cold head 6 to the cooling guide 33.

[0029] In this embodiment, the pre-tightening force of the elastic pre-tightening component 35 ensures that the upper surface of the cooling guide 33 and the lower end face of the refrigeration unit cold head 6 are always in close contact. Even if the cold screen 4 has flatness or perpendicularity deviations during processing and assembly due to its large area structure, the elastic pre-tightening component 35 can adaptively compensate for the assembly gaps at different positions through the difference in compression stroke, forcibly pressing the upper surface of the cooling guide 33 against the lower end face of the refrigeration unit cold head 6. This eliminates the microscopic cooling gaps caused by poor contact in traditional rigid connections, ensuring that the contact surface of the refrigeration unit cold head 6 transferring cold energy to the cooling guide 33 maintains a low thermal resistance and high-efficiency heat conduction state. Thus, in a multi-refrigeration unit redundant architecture, the independent cooling performance of each refrigeration unit quick-change mechanism 3 is stable and reliable.

[0030] like Figure 4 and Figure 5 As shown, the elastic preload assembly 35 includes no fewer than eight compression springs 351, each compression spring 351 being evenly distributed along the circumference of the cooling guide 33.

[0031] In this embodiment, when the refrigeration unit cold head 6 is pressed down for installation, each compression spring 351 is simultaneously compressed and generates an upward reaction force evenly distributed circumferentially, so that a uniform surface contact pressure is formed between the upper surface of the cooling guide 33 and the lower end face of the refrigeration unit cold head 6, avoiding uneven loading or poor local fit caused by a single point or a few springs; at the same time, no less than eight evenly distributed springs can more precisely compensate for the flatness deviation and perpendicularity deviation of the cold screen 4 caused by processing and assembly. Each compression spring 351 adaptively fills the micro-assembly gap at different positions through its own independent compression stroke difference, fundamentally eliminating the cooling air gap caused by poor fit in traditional rigid connections, ensuring that the cooling capacity transfer from the refrigeration unit cold head 6 to the cooling guide 33 maintains extremely low thermal resistance on the entire contact surface.

[0032] like Figure 6 and Figure 7 As shown, the safety helium replenishment mechanism 5 also includes a helium replenishment tube 52 and a stopper assembly 53. The helium replenishment tube 52 is disposed inside the mounting cylinder 51, and the stopper assembly 53 is disposed at the upper port of the helium replenishment tube 52.

[0033] In this embodiment, the helium replenishment tube 52 provides a directional channel for liquid helium injection. The plug assembly 53 seals the upper port of the helium replenishment tube 52 when not replenishing helium, preventing the continuous ejection of cryogenic helium from the helium chamber and the entry of external humid air into the helium replenishment tube 52. This effectively reduces the risk of cold loss and water vapor condensation in the helium replenishment port area. When helium replenishment is required, the plug assembly 53 can be opened to quickly connect the helium replenishment channel. The operation is convenient and the seal is reliable, providing stable initial sealing conditions for the heat curtain generated by the heating box 54, ensuring the safety and continuity of the helium replenishment operation.

[0034] The heating box 54 contains a heating element 55, which can be configured as an electric heating wire, heating rod, or heating film, among other optional forms.

[0035] like Figure 6 and Figure 7 As shown, the safety helium replenishment mechanism 5 also includes a linkage mechanism 57. One end of the linkage mechanism 57 is connected to the plug assembly 53, and the other end of the linkage mechanism 57 is connected to the airflow control component 56, so that when the plug assembly 53 is disengaged from the helium replenishment tube 52, the airflow control component 56 is triggered to open the gas duct 58.

[0036] In this embodiment, the linkage mechanism 57 achieves mechanical synchronous linkage between the opening of the plug assembly 53 and the connection of the gas guide tube 58. When the operator pulls out the plug assembly 53 to prepare for helium replenishment, the linkage mechanism 57 immediately drives the airflow control component 56 to open the gas guide tube 58, allowing the cryogenic helium gas surging out of the helium chamber due to the positive pressure in the mounting cylinder 51 to automatically enter the heating box 54 for heating. No additional electrical control or manual operation steps are required, resulting in rapid response and high reliability. Conversely, when the plug assembly 53 resets and closes the helium replenishment tube 52, the linkage mechanism 57 synchronously triggers the airflow control component 56 to close the gas guide tube 58, cutting off the path of cryogenic helium gas into the heating box 54 and avoiding unnecessary helium emissions and energy waste. Thus, the automatic following of the protective airflow opening and closing and the plug movement is achieved throughout the helium replenishment operation, significantly improving the convenience and safety of the helium replenishment operation.

[0037] Specifically, the airflow control assembly 56 includes a drive rod 561, a drive cylinder 562, and a rotating disk 563. The lower end of the drive rod 561 is connected to the rotating disk 563, which is rotatably disposed inside the air duct 58. The drive cylinder 562 is sleeved on the drive rod 561, and its upper end is threadedly connected to the drive rod 561. The drive cylinder 562 is fixed to the linkage mechanism 57. When the plug assembly 53 disengages from the helium replenishment tube 52, the linkage mechanism 57 drives the drive cylinder 562 to move upward or downward. The drive cylinder 562 converts linear motion into rotational motion of the drive rod 561 through its threaded engagement with the drive rod 561, thereby driving the rotating disk 563 to rotate precisely within the air duct 58. When the plug assembly 53 is reset, the linkage mechanism 57 drives the drive cylinder 562 to move in the opposite direction, causing the rotating disk 563 to rotate in the opposite direction to close the air duct 58. The threaded transmission airflow control assembly 56 has a compact structure and can achieve high torque and high precision motion conversion within the limited space of the installation cylinder 51. The self-locking characteristic of the threaded engagement ensures that the rotating disk 563 can stably maintain its current position in the open or closed state, avoiding accidental deflection due to airflow impact or vibration. At the same time, the purely mechanical linkage control does not require additional electrical components or controllers, and has timely response and high reliability, effectively ensuring the synchronous opening and closing of the protective airflow during helium replenishment operations.

[0038] The linkage mechanism 57 includes a lifting plate 571, a return spring 572, and a threaded sleeve 573. The end of the lifting plate 571 is connected to the drive cylinder 562, and the bottom of the lifting plate 571 is connected to the top plate 1 of the Dewar outer shell via the return spring 572. The threaded sleeve 573 is located above the lifting plate 571 and is threadedly connected to the helium replenishment tube 52. When the operator loosens the threaded sleeve 573 to move it upward along the helium replenishment tube 52, the threaded sleeve 573 pushes against the lifting plate 571, overcoming the elastic force of the return spring 572 and rising. The lifting plate 571 drives the drive cylinder 562 to move upward synchronously, thereby triggering the airflow control component 56 to open the air duct 58 through the threaded engagement between the drive cylinder 562 and the drive rod 561, thus achieving the plug. The mechanical linkage between component opening and protective gas flow initiation: When helium replenishment is completed and the threaded sleeve 573 is tightened, the threaded sleeve 573 presses down on the lifting plate 571, and the return spring 572 assists in providing downward restoring force, causing the lifting plate 571 to drive the drive cylinder 562 to move down and reset, thereby closing the gas duct 58; This linkage mechanism 57 precisely couples the thread tightening operation of the helium replenishment pipe 52 with the opening and closing of the gas flow channel through pure mechanical transmission, without the need for additional electrical control or sensors. It has a compact structure and reliable operation. At the same time, the return spring 572 ensures that the gas duct 58 remains closed when not replenishing helium, avoiding the waste of cold energy and safety hazards caused by continuous leakage of cryogenic helium, and significantly improving the convenience of helium replenishment operation and system safety.

[0039] like Figure 7 and Figure 8As shown, the safety helium replenishment mechanism 5 also includes an airflow guide hood 59, which is sleeved on the outside of the mounting cylinder 51 and located below the heating box 54. The airflow guide hood 59 is connected to the air outlet of the heating box 54.

[0040] In this embodiment, the airflow guide shroud 59 provides a directional flow channel for the heated helium. After the heating box 54 heats the low-temperature helium, the hot helium enters the airflow guide shroud 59 from the outlet. Under the constraint of the airflow guide shroud 59, it flows upward along the outer wall of the mounting cylinder 51, forming a uniform and continuous hot helium curtain. This curtain surrounds the helium replenishment port, effectively isolating the external humid air from direct contact with the helium replenishment port, preventing water vapor from condensing into ice on the inner wall of the helium replenishment pipe 52 and the mounting cylinder 51. At the same time, the positive pressure environment of the hot helium curtain further blocks the intrusion of external moisture, thereby ensuring the continuity and safety of long-term helium replenishment operations and avoiding the risk of equipment failure caused by icing blocking the helium replenishment channel.

[0041] like Figure 7 and Figure 8 As shown, an annular rotating air box 510 is rotatably connected to the air outlet of the heating box 54. Multiple inclined discharge holes 5101 with the same inclined direction are provided through the inner side wall of the rotating air box 510. Multiple guide vanes 591 are provided on the outer circumferential side of the airflow guide cover 59.

[0042] In this embodiment, when heated helium enters the rotating gas box 510 from the outlet of the heating box 54 and is ejected through the inclined discharge hole 5101, the airflow reaction force drives the rotating gas box 510 to rotate automatically, so that the hot helium is evenly distributed circumferentially in a rotating jet manner, forming a rotating upward airflow with more comprehensive coverage and no blind spots. At the same time, multiple guide vanes 591 arranged circumferentially on the outer wall of the airflow guide cover 59 forcefully rectify and guide the upward airflow, dividing the hot helium that may be in a rotating diffusion state into multiple air jets that flow in an orderly manner along the axis, suppressing circumferential turbulence and radial diffusion, so that the hot helium is pushed vertically upward along the outer wall of the mounting cylinder 51 in a more concentrated and higher flow direction, thereby forming a dense hot gas curtain with uniform thickness, complete coverage, and not easily blown away by the external airflow around the helium replenishment port, which significantly improves the forming efficiency and anti-icing stability of the hot gas barrier.

[0043] like Figure 6 and Figure 7 As shown, the helium replenishment tube 52 includes a first helium replenishment tube 521 and a second helium replenishment tube 522, the length of the first helium replenishment tube 521 is greater than the length of the second helium replenishment tube 522; the plug assembly 53 includes a plug body 531, a long rod 532 is provided at the bottom of the plug body 531, and multiple cryogenic baffles 533 are provided axially on the long rod 532.

[0044] In this embodiment, the dual-tube structure provides flexible options for helium replenishment. When liquid helium loss is significant and rapid replenishment is required, opening the first helium replenishment tube 521 allows liquid helium to be directly injected into the depth of the helium cavity, avoiding dripping, splashing, and evaporation losses. When a small amount of fine replenishment is needed, opening the shorter second helium replenishment tube 522 facilitates precise control of the replenishment volume, preventing overfilling. At the same time, the amount of residual cryogenic helium in the shorter tube is small, and the jet intensity is weak when it is opened, further reducing the risk of local cryogenic temperature and water vapor condensation at the helium replenishment port. When the plug assembly 53 is pulled away from the upper port of the helium replenishment tube 52, the cryogenic helium driven by positive pressure in the helium cavity jets upward along the helium replenishment tube 52, colliding sequentially with multiple cryogenic baffles 533. The multi-stage baffles disperse the concentrated jet into a dispersed turbulent flow, effectively reducing the helium ejection velocity and the concentration of cold energy per unit area, weakening the cryogenic impact intensity in the helium replenishment port area, and providing buffer time for the establishment of a thermal curtain, thereby significantly improving the safety and reliability of the helium replenishment operation.

[0045] like Figure 1 As shown, it also includes a main controller 7, which is electrically connected to the status detection sensors of each refrigerator quick-change mechanism 3 and the heating element in the heating box 54 of the safety helium replenishment mechanism 5.

[0046] In this embodiment, when the main controller 7 detects a fault in any of the quick-change mechanisms 3 of the refrigeration unit through the status detection sensor, it automatically maintains at least one other quick-change mechanism 3 of the refrigeration unit to continue operating, ensuring that the low temperature state of the cold screen 4 is not affected by a single point of failure, and at the same time issues a replaceable prompt signal, so that the operator can replace the faulty module online without stopping the machine.

[0047] Specifically, the condition monitoring sensor can be a temperature sensor to detect changes in the temperature of the cold head, cold screen, or cold finger. When the temperature rises abnormally, it can be inferred that the refrigeration unit's efficiency has decreased or that a malfunction has occurred. Commonly used sensors include platinum resistance temperature sensors, silicon diode temperature sensors, and Cernox temperature sensors, which have advantages in resisting magnetic interference in strong magnetic field environments.

[0048] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

Claims

1. An integrated maintenance and helium replenishment device for a superconducting magnet system, characterized in that, include: The top plate (1) of the Dewar shell is fixedly installed on the top of the superconducting magnet Dewar (2); At least one quick-change mechanism (3) for the refrigeration unit is installed on the top plate (1) of the Dewar housing; At least one safe helium replenishment mechanism (5) is installed on the top plate (1) of the Dewar shell; The quick-change mechanism (3) of the refrigerator includes a vacuum isolation flange (31), a bellows (32) and a cooling guide (33). The vacuum isolation flange (31) is sealed to the top plate (1) of the Dewar shell. The bellows (32) is sleeved on the outside of the refrigerator cold head (6) and its lower end is connected to the cooling guide (33). The cooling guide (33) is used to conduct heat to the cold screen (4) located inside the superconducting magnet Dewar (2). The safety helium replenishment mechanism (5) includes an installation cylinder (51), a heating box (54), and an airflow control component (56). The installation cylinder (51) passes through the top plate (1) of the Dewar shell and its lower end is connected to the helium cavity inside the superconducting magnet Dewar (2). The heating box (54) is connected to the interior of the installation cylinder (51) through a gas guide pipe (58). The airflow control component (56) is used to control the opening and closing of the gas guide pipe (58). At least one of the refrigeration quick-change mechanisms (3) and at least one of the safe helium replenishment mechanisms (5) are arranged circumferentially on the top plate (1) of the Dewar shell.

2. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 1, characterized in that, The quick-change mechanism (3) of the refrigeration unit also includes a flexible cooling belt (34), and the cooling component (33) is flexibly heat-conductingly connected to the cold screen (4) through the flexible cooling belt (34).

3. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 1, characterized in that, The quick-change mechanism (3) for the refrigeration unit also includes an elastic pre-tightening component (35), which is disposed on the side of the cooling guide (33) facing away from the refrigeration unit cold head (6) and is used to apply a pre-tightening force toward the refrigeration unit cold head (6) to the cooling guide (33).

4. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 3, characterized in that, The elastic preload assembly (35) includes no fewer than eight compression springs (351), each of which is evenly distributed along the circumference of the cooling conductor (33).

5. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 1, characterized in that, The safety helium replenishment mechanism (5) also includes a helium replenishment tube (52) and a plug assembly (53). The helium replenishment tube (52) is disposed inside the mounting cylinder (51), and the plug assembly (53) is disposed at the upper port of the helium replenishment tube (52).

6. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 5, characterized in that, The safety helium replenishment mechanism (5) also includes a linkage mechanism (57). One end of the linkage mechanism (57) is connected to the plug assembly (53), and the other end of the linkage mechanism (57) is connected to the airflow control component (56), so that when the plug assembly (53) is disengaged from the helium replenishment tube (52), the airflow control component (56) is triggered to open the gas pipe (58).

7. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 1, characterized in that, The safety helium replenishment mechanism (5) also includes an airflow guide hood (59), which is sleeved on the outside of the mounting cylinder (51) and located below the heating box (54). The airflow guide hood (59) is connected to the air outlet of the heating box (54).

8. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 7, characterized in that, The heating box (54) is rotatably connected to an annular rotating air box (510) at its air outlet. Multiple inclined discharge holes (5101) with the same inclination direction are provided through the inner side wall of the rotating air box (510). Multiple guide vanes (591) are provided on the outer circumferential side of the airflow guide cover (59).

9. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 5, characterized in that, The helium replenishment tube (52) includes a first helium replenishment tube (521) and a second helium replenishment tube (522), the length of the first helium replenishment tube (521) being greater than the length of the second helium replenishment tube (522); the plug assembly (53) includes a plug body (531), the bottom of the plug body (531) is provided with a long rod (532), and the long rod (532) is provided with multiple cryogenic baffles (533) axially.

10. The integrated maintenance and helium replenishment device for the superconducting magnet system as described in claim 1, characterized in that, It also includes a main controller (7), which is electrically connected to the status detection sensor of the quick replacement mechanism (3) of the refrigerator and the heating element in the heating box (54) of the safety helium replenishment mechanism (5).

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