Superconducting magnet structure and magnetic resonance imaging equipment

Abstract

The present invention discloses a superconducting magnet structure and magnetic resonance imaging equipment, belonging to the field of superconducting magnet technology. The superconducting magnet structure includes a vacuum cylinder, a cooling liquid tank, a cold screen, and a cold head cavity. The cooling liquid tank, the cold screen, and the cold head cavity are all placed in a storage space inside the vacuum cylinder. The cooling liquid tank is used to accommodate cooling liquid for cooling the superconducting coil. The cold screen is arranged circumferentially around the cooling liquid tank. A plurality of first conductors are arranged circumferentially on the cold screen. A second conductor capable of abutting the cold head is arranged in the cold head cavity. The second conductor and at least one first conductor are thermally connected. The first conductor on the cold screen is thermally connected to the second conductor in the cold head cavity. Through direct contact, cooling is more sufficient, reducing the volatilization of liquid ammonia in the superconducting magnet structure. Further, single cold head refrigeration can be achieved, simplifying the entire superconducting magnet structure, reducing manufacturing costs, and reducing the pressure inside the structure, making the overall structure safer.

Description

Technical Field

[0001] The present invention relates to the field of superconducting magnet technology, and in particular to a superconducting magnet structure and a magnetic resonance imaging device. Background Art

[0002] Superconducting magnet structures include superconducting magnets, which are magnets made of superconducting coils. Superconducting coils operate without resistance at low temperatures, offering significant advantages and are widely used in industry, scientific research, and healthcare.

[0003] To keep the superconducting coils in a low-temperature environment, superconducting magnet structures use cold shields to cool the superconducting coils. To improve the temperature uniformity of the cold shield, existing superconducting magnet structures use dual cold heads symmetrically arranged on either side of the cold shield. This results in a complex structure, high cooling costs, and limited improvement in cold shield temperature uniformity. Summary of the Invention

[0004] An object of the present invention is to provide a superconducting magnet structure having a compact structure, low cost and uniform cold shield temperature.

[0005] To achieve this object, the present invention adopts the following technical solutions:

[0006] A superconducting magnet structure includes a vacuum cylinder having an accommodating space, and further includes:

[0007] A coolant tank, the coolant tank being used to contain coolant for cooling the superconducting coil;

[0008] A cold screen is arranged around the circumference of the coolant tank, and a plurality of first conductors are arranged on the cold screen along the circumference;

[0009] A cold head cavity is provided with a second conductor capable of abutting against the cold head, and the second conductor is thermally connected to at least one of the first conductors.

[0010] Preferably, the superconducting magnet structure further includes a power cord, one end of which is electrically connected to the superconducting coil, and the other end of which passes through the cold head cavity, and the power cord abuts against the second conductor.

[0011] Preferably, the superconducting magnet structure further includes a signal line, which passes through the cold head cavity and abuts against the second conductor.

[0012] Preferably, the first conductor is a copper rib.

[0013] Preferably, the second conductor is a copper block.

[0014] Preferably, the second conductor and the first conductor are connected by thermal conduction via a copper tape.

[0015] Preferably, the superconducting magnet structure further includes a service cavity, one end of which is connected to the coolant tank, and the other end of which passes through the vacuum cylinder.

[0016] Preferably, a platform is provided on the vacuum cylinder, and the cold head cavity and the service cavity are both provided on the platform.

[0017] Preferably, the coolant tank is a liquid helium tank, and the coolant is liquid helium.

[0018] Another object of the present invention is to provide a magnetic resonance imaging device having high operating stability, high safety and low manufacturing cost.

[0019] To achieve this object, the present invention adopts the following technical solutions:

[0020] A magnetic resonance imaging device comprises the above-mentioned superconducting magnet structure.

[0021] Beneficial effects of the present invention:

[0022] The present invention provides a superconducting magnet structure, which includes a vacuum cylinder, a cooling liquid tank, a cold shield, and a cold head cavity. The cooling liquid tank, the cold shield, and the cold head cavity are all placed in a storage space within the vacuum cylinder. The cooling liquid tank is used to accommodate cooling liquid for cooling superconducting coils. The cold shield is arranged circumferentially around the cooling liquid tank. A plurality of first conductors are arranged circumferentially on the cold shield. A second conductor capable of abutting the cold head is arranged in the cold head cavity. The second conductor and at least one first conductor are thermally connected. The first conductor on the cold shield is thermally connected to the second conductor in the cold head cavity through direct contact, which makes cooling more sufficient and reduces the volatilization of liquid ammonia in the superconducting magnet structure. Furthermore, a single cold head can be used for refrigeration, simplifying the entire superconducting magnet structure, reducing manufacturing costs, and reducing the pressure inside the structure, making the overall structure safer.

[0023] This embodiment also provides a magnetic resonance imaging device, which improves working safety and working stability and reduces manufacturing costs by using the above-mentioned superconducting magnet structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the superconducting magnet structure provided by the present invention;

[0025] Figure 2 yes Figure 1 A partial enlarged view of part A.

[0026] Figure 3 It is a structural schematic diagram of the cold head cavity and service cavity of the superconducting magnet structure provided by the present invention.

[0027] In the picture:

[0028] 1. Vacuum cylinder; 2. Coolant tank; 3. Cold shield; 4. First conductor; 5. Cold head cavity; 6. Second conductor; 7. Copper tape; 8. Power cord; 9. Signal line; 10. Service cavity. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be noted that the terms "center," "up," "down," "left," "right," "vertical," "horizontal," "inside," and "outside" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0032] This embodiment provides a superconducting magnet structure, such as Figure 1 As shown, the superconducting magnet structure includes a vacuum cylinder 1, a cooling liquid tank 2, a superconducting coil (not shown), a cold shield 3, and a cold head cavity 5. The vacuum cylinder 1 is a cylindrical structure made of non-magnetic material, such as stainless steel. In this embodiment, the vacuum cylinder 1 is a cylindrical structure made of non-magnetic material. An accommodating space is provided within the vacuum cylinder 1, and the cooling liquid tank 2, superconducting coil, cold shield 3, and cold head cavity 5 are all placed within the accommodating space.

[0033] The coolant tank 2 is used to contain the coolant, and the superconducting coil is placed in the coolant tank 2, and at least part of the superconducting coil is immersed in the coolant. Optionally, the coolant tank 2 is a liquid helium tank, and the coolant is liquid helium. Liquid helium can provide a low-temperature environment for the superconducting coil, for example, at a liquid helium temperature of 4.2K (-269°C) at an absolute temperature, so that the superconducting coil placed in the liquid helium can maintain its superconducting properties. Of course, in other embodiments, the coolant and coolant tank 2 that can provide a low-temperature environment for the superconducting coil and do not affect the normal operation of the superconducting coil are also applicable to the superconducting magnet structure in this embodiment. Further optionally, the liquid helium tank is a cylindrical structure arranged coaxially with the vacuum cylinder 1.

[0034] The cold shield 3 is mainly used to reduce the radiation heat leakage from the indoor heat to the superconducting coil, such as Figure 1 As shown, the cold shield 3 is an annular structure, which is sleeved on the outer side of the coolant tank 2 along the circumference of the coolant tank 2. Optionally, in this embodiment, the cold shield 3 is an annular structure.

[0035] like Figure 1 and Figure 2 As shown, multiple first conductors 4 are distributed circumferentially on the cold shield 3, preferably evenly distributed. The first conductors 4 are strip-shaped structures made of a metal with good thermal conductivity. The cross-sectional shape of the strips can be regular or irregular, such as circular, square, or elliptical, depending on the requirements. Optionally, the first conductors 4 are copper ribs, each connected to the inner wall of the cold shield 3 parallel to the central axis of the cold shield 3. The multiple copper ribs are evenly distributed on the inner wall of the cold shield 3 and arranged in a circular array centered on the central axis of the cold shield 3. Copper has excellent thermal conductivity at low temperatures. By evenly distributing multiple copper ribs on the cold shield 3, the temperature of the cold shield 3 can be more uniform. Of course, in other embodiments, other metals with good thermal conductivity can also be used to form the first conductors 4, which will not be discussed here.

[0036] Furthermore, to enhance the connection strength and thermal conductivity between the cold shield 3 and the copper ribs, in this embodiment, the copper ribs are configured as cylindrical or cylindrical structures with arc-shaped surfaces, thereby increasing the contact and connection area between the copper ribs and the cold shield 3. The cold shield 3 and the copper ribs can be connected by welding. In other embodiments, multiple copper ribs can be evenly distributed on the outer surface of the cold shield 3; alternatively, multiple copper ribs can be evenly distributed on both the inner and outer surfaces of the cold shield 3. Alternatively, multiple copper ribs can be cross-welded on the surface of the cold shield 3 to form a mesh structure, further enhancing the temperature uniformity of the cold shield 3.

[0037] The cold head cavity 5 is mainly used to connect the cold head of the refrigerator and the cold shield 3. Existing refrigerators can be used for the superconducting magnet structure in this embodiment, and the specific structure of the refrigerator and the cold head will not be described here. In this embodiment, since multiple copper ribs are provided on the cold shield 3, multiple copper ribs are used to conduct heat on the cold shield 3. Therefore, compared with the prior art, which requires two cold head cavities 5 and two cold heads for cooling, in this embodiment, only one cold head cavity 5 is required, and one cold head can make the temperature of the cold shield 3 more uniform. The reduction in the number of cold head cavities 5 and cold heads greatly simplifies the structure of the superconducting magnet structure and reduces the manufacturing cost of the superconducting magnet structure.

[0038] Specifically, a second conductor 6 is disposed within the cold head cavity 5. The second conductor 6 is thermally connected to the first conductor 4 through direct contact, ensuring more efficient cooling and reducing the volatilization of liquid ammonia from the superconducting magnet structure. The second conductor 6 is a block-shaped structure made of a material with good thermal conductivity. In this embodiment, the second conductor 6 is a copper block, which is placed within the cold head cavity 5. The thermal connection specifically refers to a conductive structure made of a material with good thermal conductivity, such as a strip-shaped conductive tape, connected between the first conductor 4 and the second conductor 6. In this embodiment, a copper tape 7 is disposed between the first conductor 4 and the second conductor 6. One end of the copper tape 7 is connected to the copper block, and the other end is connected to a copper rib. Optionally, the copper tape 7 and the copper block, and the copper tape 7 and the copper rib, are connected by welding. This reduces the contact thermal resistance at the joints, improves the cooling efficiency of the cold head on the cold shield 3, and further helps to reduce the temperature of the cold shield 3.

[0039] like Figure 3 As shown, the superconducting magnet structure also includes a service cavity 10, which is a communication channel for connecting the inside and outside of the superconducting magnet structure. In the prior art, the common functions of the service cavity 10 are to serve as a lead-out path for the power line 8, a lead-out path for the signal line 9, an infusion port path, and an exhaust path.

[0040] A power supply system for a superconducting magnet (not shown) placed in a room-temperature environment supplies power to the superconducting magnet within the superconducting environment via power cord 8. Power cord 8 is a relatively thick copper or stainless steel wire that charges the superconducting coils. In this embodiment, one end of power cord 8 is electrically connected to the superconducting coils, while the other end passes through the cold head cavity 5 and over the copper block. This arrangement ensures smooth passage through the service cavity 10, reducing the helium discharge resistance in the event of a quench in the superconducting magnet structure, thereby rapidly reducing the peak pressure of the superconducting magnet structure.

[0041] Signal lines 9 carry electrical wiring for detectors and controllers within the superconducting magnet system. In this embodiment, they also pass through the cold head cavity 5. This arrangement allows the service cavity 10 to function solely as a fluid inlet and exhaust passageway, ensuring smoother access to the service cavity 10. This further reduces helium discharge resistance in the event of a quench in the superconducting magnet structure, lowering internal pressure and improving overall safety.

[0042] Furthermore, the superconducting magnet structure can be designed with lower design pressures in mind, allowing for the use of thinner materials. By reducing the design pressure of the entire superconducting magnet structure, the thickness of the material can be reduced while maintaining the same material thickness, which helps reduce heat transfer into the superconducting magnet structure, thereby achieving zero volatilization of liquid helium.

[0043] In summary, compared with the dual-cold-head refrigeration in the prior art, the superconducting magnet structure in this embodiment evenly distributes copper ribs with good thermal conductivity on the cold shield 3. Therefore, only a single cold head is required to achieve uniform temperature of the cold shield 3, thereby achieving the purpose of zero volatilization of liquid helium.

[0044] In addition, compared with the power line 8 and signal line 9 passed through the service cavity 10 in the prior art, the cooling path is: copper block in the cooling cavity - copper belt 7 - copper block in the service cavity 10 - power line 8 and signal line 9. In this embodiment, by shifting the passing position of the power line 8 and signal line 9 from the service cavity 10 to the cold head cavity 5, and making the line directly contact the copper block, the cooling path is changed to the copper block in the cooling cavity - power line 8 and signal line 9. This arrangement reduces the intermediate connection points, improves the adequacy of cooling, and reduces the heat entering the superconducting magnet structure through the power line 8 and signal line 9.

[0045] This embodiment also provides a magnetic resonance imaging device, which includes the above-mentioned superconducting magnet structure. Since the superconducting magnet structure is a key component of the magnetic resonance imaging device, and the superconducting magnet structure in this embodiment is connected by direct contact heat conduction, not only does it provide more efficient cooling and reduce the volatilization of liquid ammonia from the superconducting magnet structure, but it also achieves single cold head cooling, simplifies the entire superconducting magnet structure, reduces manufacturing costs, reduces internal pressure, and makes the overall structure safer. Therefore, the operating safety and stability of the magnetic resonance imaging device are greatly improved, and manufacturing costs are also reduced.

[0046] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A superconducting magnet structure, comprising a vacuum cylinder (1), wherein the vacuum cylinder (1) has an accommodating space and is characterized in that: The superconducting magnet structure further includes: A cooling liquid tank (2), the cooling liquid tank (2) being used to accommodate cooling liquid for cooling the superconducting coil; A cold screen (3), the cold screen (3) being arranged circumferentially around the coolant tank (2), and a plurality of first conductors (4) being arranged circumferentially on the cold screen (3); a cold head cavity (5), wherein a second conductor (6) capable of abutting the cold head is provided in the cold head cavity (5), and the second conductor (6) is thermally connected to at least one of the first conductors (4); The superconducting magnet structure further includes a power line (8), one end of the power line (8) is electrically connected to the superconducting coil, and the other end is arranged through the cold head cavity (5), and the power line (8) is in contact with the second conductor (6); The first conductor (4) is a copper rib.

2. The superconducting magnet structure according to claim 1, characterized in that The superconducting magnet structure further comprises a signal line (9), which is arranged through the cold head cavity (5) and abuts against the second conductor (6).

3. The superconducting magnet structure according to claim 1, characterized in that The second conductor (6) is a copper block.

4. The superconducting magnet structure according to claim 3, characterized in that: The second conductor (6) and the first conductor (4) are connected to each other by heat conduction via a copper strip (7).

5. The superconducting magnet structure according to claim 1, characterized in that The superconducting magnet structure further comprises a service cavity (10), one end of the service cavity (10) being in communication with the cooling liquid tank (2), and the other end of the service cavity (10) passing through the vacuum cylinder (1).

6. The superconducting magnet structure according to claim 5, characterized in that A platform is provided on the vacuum cylinder (1), and the cold head cavity (5) and the service cavity (10) are both provided on the platform.

7. The superconducting magnet structure according to any one of claims 1 to 6, characterized in that: The coolant tank (2) is a liquid helium tank, and the coolant is liquid helium.

8. A magnetic resonance imaging device, characterized in that The superconducting magnet structure comprises the superconducting magnet structure according to any one of claims 1 to 7.

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