CN112992465B

CN112992465B - Superconducting magnet and magnetic resonance imaging system

Info

Publication number: CN112992465B
Application number: CN201911283106.6A
Authority: CN
Inventors: 邹利军
Original assignee: Shanghai United Imaging Healthcare Co Ltd
Current assignee: Shanghai United Imaging Healthcare Co Ltd
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2023-03-14
Anticipated expiration: 2039-12-13
Also published as: CN112992465A

Abstract

The application provides a superconducting magnet and a magnetic resonance imaging system. The first cavity is communicated with the second cavity and can surround to form an independent cavity. The cooling medium is filled in the independent cavity, and the outer coil and the inner coil can be completely soaked, so that all parts of the magnet coil assembly can be uniformly cooled, and a good problem gradient is kept. In addition, the superconducting magnet can avoid the problem of thermal disturbance influence caused by the fact that the coil or the coil framework is directly cooled by the traditional superconducting magnet through a refrigerator. The size and the shape of the first cavity and the second cavity can be set according to actual requirements, extra space for accommodating the outer coil and the inner coil can be reduced, and all parts of the magnet coil group can be soaked. Therefore, the consumption of the cooling medium can be obviously reduced through the first cavity and the second cavity, the situation that a large amount of cooling medium is injected to soak the superconducting coil is avoided, and the cost is reduced.

Description

Superconducting magnet and magnetic resonance imaging system

Technical Field

The present application relates to the field of medical equipment technology, and in particular, to a superconducting magnet and a magnetic resonance imaging system.

Background

With the development of biomedical engineering and medical imaging, magnetic resonance imaging (mri) is used as another important medical diagnostic technique after the relay computer tomography technique, and plays an increasingly important role in medical diagnosis. In the magnetic resonance imaging device, the superconducting magnet provides a main magnetic field, so that the coil can keep a low-temperature superconducting state, and the quality of magnetic resonance imaging is greatly influenced.

Because liquid helium is expensive, the manufacturing cost of the superconducting magnet is greatly influenced, and more magnets adopt a refrigerator to directly cool a superconducting coil or a coil skeleton. However, such design often fails to uniformly cool all parts of the coil, thereby limiting the use of mr application sequences and affecting the quality of mr imaging.

Disclosure of Invention

In view of this, it is necessary to provide a superconducting magnet capable of cooling all coils, coil joints, and superconducting switches, in order to solve the problem that all parts of the coil cannot be uniformly cooled in the superconducting magnet directly cooled by a refrigerator.

The application provides a superconducting magnet which comprises a magnet coil group, a low-temperature container, a first cavity and a second cavity. The magnet coil assembly comprises an outer coil and an inner coil.

The low-temperature container surrounds and forms an accommodating space. The first cavity is arranged in the accommodating space. The inner coil is arranged in the first cavity. The second cavity is arranged in the accommodating space. The outer coil is arranged in the second cavity. The first cavity is communicated with the second cavity. The first cavity and the second cavity are filled with cooling medium.

In one embodiment, the superconducting magnet further comprises a third cavity. The third cavity is arranged in the accommodating space. The third cavity is communicated with the first cavity. The third cavity is communicated with the second cavity.

In one embodiment, the superconducting magnet further comprises an inner former. The inner coil frame is arranged in the accommodating space. The inner coil is arranged on the inner coil frame. The middle coil frame is arranged in the accommodating space. The middle coil frame is arranged on one side, far away from the central shaft, of the inner coil frame. The first cylindrical sealing cylinder is arranged in the accommodating space. The first cylindrical sealing cylinder is arranged on one side, close to the central shaft, of the inner coil frame. The two annular plates are disposed between the first cylindrical sealing cylinder and the intermediate bobbin. The intermediate coil former, the first cylindrical sealing cylinder and the two annular plates surround to form the first cavity.

In one embodiment, the superconducting magnet further comprises an intermediate former, a first cylindrical sealing barrel and two annular plates. The middle coil frame is arranged in the accommodating space. The first cylindrical sealing cylinder is arranged in the accommodating space. The first cylindrical sealing cylinder is arranged on one side, close to the central shaft, of the middle coil frame. The two annular plates are arranged between the first cylindrical sealing barrel and the intermediate coil frame, the first cylindrical sealing barrel and the two annular plates surround to form the first cavity. The inner coil is disposed on the intermediate bobbin or the first cylindrical sealing cylinder.

In one embodiment, the superconducting magnet further comprises an outer former and a second cylindrical sealing barrel. The outer coil frame is arranged in the accommodating space. The outer coil is arranged on the outer coil frame. The outer coil former is arranged on one side, far away from the central shaft, of the middle coil former. The second cylindrical sealing cylinder is arranged in the accommodating space. The second cylindrical sealing cylinder is arranged on one side, away from the middle coil former, of the outer coil former. And the second cylindrical sealing cylinder is connected with the outer coil frame in a sealing manner. The outer coil frame and the second cylindrical sealing barrel are surrounded to form the second cavity.

In one embodiment, the superconducting magnet further comprises a refrigeration device. The refrigerating device is arranged on one side of the low-temperature container far away from the accommodating space. The refrigerating device is connected with the first cavity in a sealing mode. The refrigerating device is used for condensing and refluxing the cooling medium.

In one embodiment, the first cavity, the second cavity, and the third cavity enclose a cooling cavity. And the cooling cavity and the inner wall of the low-temperature container surround to form an outer cavity. The refrigerating device is connected with the first cavity through a third pipeline. The superconducting magnet further comprises an exhaust pipeline and a control valve. The exhaust pipeline is arranged on the third pipeline and is used for being communicated with the outer cavity. The control valve is arranged in the exhaust pipeline.

In one embodiment, the superconducting magnet further comprises a refrigeration device. The refrigerating device is arranged on one side of the low-temperature container far away from the accommodating space. The refrigerating device is connected with the first cavity. And an opening is arranged at the connecting position of the refrigerating device and the first cavity.

In one embodiment, the present application provides a magnetic resonance imaging system including a cryogenic vessel, at least one first cavity, at least one second cavity, and a refrigeration device. The low-temperature container is provided with an accommodating space. At least one first cavity is disposed within the cryogenic container. And a superconducting coil is fixed in the first cavity. At least one second cavity is arranged in the low-temperature container and located on the outer periphery side of the first cavity, a superconducting coil is fixed in the second cavity, and the second cavity is communicated with the first cavity. The refrigerating device is arranged on the low-temperature container and is thermally coupled with at least one cavity in the accommodating space of the low-temperature container. The refrigeration of the refrigeration device is extremely deep into the accommodating space of the low-temperature container, and the refrigeration electrode is thermally coupled with the first cavity.

In one embodiment, the superconducting magnet further comprises at least one former. At least one coil former is disposed inside the cryogenic vessel for fixing the superconducting coils. And the bobbin forms a portion of the first or second cavity. And a gap is formed between the first cavity or the second cavity and the superconducting coil, and a cooling medium is filled in the gap.

The superconducting magnet provided by the embodiment of the application. The first cavity is communicated with the second cavity to form an independent cavity. The independent cavity is filled with cooling medium, the outer coil and the inner coil can be completely soaked, so that all parts of the magnet coil group can be uniformly cooled, and good problem gradient is kept. Therefore, all parts of the magnet coil group can be uniformly cooled through the superconducting magnet, and the problem of thermal disturbance influence caused by the fact that the coil or the coil framework is directly cooled through a refrigerator in the conventional superconducting magnet is solved.

Meanwhile, the size and the shape of the first cavity and the second cavity can be set according to actual requirements, so that the accommodating space of the outer coil and the extra space outside the inner coil can be reduced, and all parts of the magnet coil group can be soaked. Therefore, the consumption of the cooling medium can be obviously reduced through the first cavity and the second cavity, the situation that a large amount of cooling medium is injected to soak the superconducting coil is avoided, and the cost is reduced. Therefore, the superconducting magnet can adjust the amount of the cooling medium according to actual requirements by controlling the volumes of the first cavity and the second cavity, and high-level soaking can be realized through less filling amount of the cooling medium. Therefore, the superconducting magnet not only achieves the aim of low liquid helium, but also does not limit the use requirements of a magnetic resonance sequence and the like.

Drawings

Fig. 1 is a schematic partial cross-sectional structure view of a superconducting magnet provided herein;

FIG. 2 is a schematic diagram illustrating a partial cross-sectional view of an exhaust line and control valve of a superconducting magnet in one embodiment provided herein;

fig. 3 is a schematic partial sectional view of an end-to-end communication cooling cavity of a superconducting magnet according to an embodiment provided in the present application;

FIG. 4 is a schematic diagram illustrating an open-ended partial cross-sectional configuration of a third conduit in an embodiment of the present disclosure.

Description of the reference numerals

The superconducting magnet comprises a superconducting magnet 100, a magnet coil group 10, an outer coil 110, an inner coil 120, a cryogenic container 80, a first cavity 33, a second cavity 43, a containing space 810, a third cavity 50, an inner coil frame 230, an intermediate coil frame 220, a first cylindrical sealing cylinder 320, an annular plate 310, an outer coil frame 210, a second cylindrical sealing cylinder 410, a refrigerating device 90, a refrigerating pole 60, a cooling cavity 70, an outer cavity 73, a third pipeline 610, an exhaust pipeline 710, a control valve 720, a fourth pipeline 740 and an opening 630.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is further described in detail below by way of embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" as used herein includes both direct and indirect connections (couplings), unless otherwise specified. In the description of the present application, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be considered as limiting the present application.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "above," and "over" a second feature may be directly on or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

The present application proposes a superconducting magnet 100. The superconducting magnet 100 includes a cryogenic vessel 80, at least one first cavity 33, at least one second cavity 43, and a cooling device 90. The low temperature container 80 has an accommodating space 810. At least one first cavity 33 is disposed within the cryogenic container 80. A superconducting coil is fixed in the first cavity 33. The superconducting coils comprise a set of magnet coils 10. The magnet coil assembly 10 includes an outer coil 110 and an inner coil 120. At least one second cavity 43 is provided in the low temperature container 80 and located on the outer circumferential side of the first cavity 33. A superconducting coil is fixed in the second cavity 43, and the second cavity 43 is communicated with the first cavity 33. The refrigerating device 90 is disposed on the low temperature container 80 and connected to at least one cavity in the accommodating space 810 of the low temperature container 80. The refrigeration pole 60 of the refrigeration device 90 extends into the accommodating space 810 of the low-temperature container 80, and the refrigeration pole 60 is thermally coupled to the first cavity 33. It will be appreciated that the "cold plate" 60 of the embodiments of the present application may also be referred to as a "cold head", such as a secondary cold head of a refrigerator.

In one embodiment, superconducting magnet 100 further includes at least one former disposed inside cryogenic vessel 80 for securing a superconducting coil, and the former forms a portion of first or

second cavity

33, 43, with a gap formed between first or

second cavity

33, 43 and the superconducting coil, the gap being filled with a cooling medium. Compared with the prior art that the cooling medium is filled in the accommodating space of the whole low-temperature container, the cooling medium is filled in the gap formed between the first cavity 33 or the second cavity 43 and the superconducting coil, and the volume of the required cooling medium is obviously reduced.

Referring to fig. 1, an embodiment of the present application provides a superconducting magnet 100. The superconducting magnet 100 includes a magnet coil assembly 10, a cryogenic vessel 80, a first cavity 33, and a second cavity 43. The magnet coil assembly 10 includes an outer coil 110 and an inner coil 120, and the outer coil 110 is disposed on the outer peripheral side of the inner coil 120. The inner coil 120 may also be referred to as a "field coil," which includes coils at the ends and an inner coil disposed between the coils at the ends. The outer coil 110, which may also be referred to as a "shield coil," is typically provided with a diameter greater than that of the inner coil 120 for confining external stray fields. The low temperature container 80 surrounds and forms a receiving space 810. The first cavity 33 is disposed in the accommodating space 810. The inner coil 120 is disposed in the first cavity 33. The second cavity 43 is disposed in the accommodating space 810. The outer coil 110 is disposed in the second cavity 43. The first cavity 33 and the second cavity 43 are in communication. The first cavity 33 and the second cavity 43 are filled with a cooling medium.

The outer coil 110, the inner coil 120, and the low temperature container 80 are coaxially assembled and fixed, and are symmetrical with respect to the central axis of the low temperature container 80. The first cavity 33 is communicated with the second cavity 43, and can be enclosed to form an independent cavity. The cooling medium is filled in the independent cavity, so that the outer coil 110 and the inner coil 120 can be completely immersed, all parts of the magnet coil assembly 10 can be uniformly cooled, and a good cooling effect is kept. Therefore, all parts of the magnet coil assembly 10 can be uniformly cooled by the superconducting magnet 100, and the problem of thermal disturbance influence caused by the fact that the conventional superconducting magnet directly cools the coil or the coil skeleton through a refrigerator is avoided.

Meanwhile, the size and shape of the first cavity 33 and the second cavity 43 may be set according to actual requirements, so that an additional space for accommodating the outer coil 110 and the inner coil 120 may be reduced, and all parts of the magnet coil assembly 10 may be immersed. Therefore, the consumption of the cooling medium can be reduced significantly by the first cavity 33 and the second cavity 43, and the injection of a large amount of cooling medium to soak the superconducting coil is avoided, thereby reducing the cost. Therefore, the superconducting magnet 100 can adjust the amount of the cooling medium according to actual requirements by controlling the volumes of the first cavity 33 and the second cavity 43, and thus high-level soaking can be realized by a small amount of the cooling medium. Therefore, the superconducting magnet 100 not only achieves the target of low liquid helium, but also does not limit the use requirements of a magnetic resonance sequence and the like.

In one embodiment, the superconducting magnet 100 further comprises a third cavity 50. The third cavity 50 is disposed in the accommodating space 810. The third cavity 50 communicates with the first cavity 33. The third cavity 50 communicates with the second cavity 43.

The coil superconducting joints, the superconducting switches, the cryogenic electronics, and the like of the superconducting magnet 100 are disposed in the third chamber 50. Meanwhile, a cooling chamber 70 communicating with each other is formed by the third chamber 50, the second chamber 43 and the first chamber 33. The magnet coil assembly 10, the coil joints, the superconducting switch and the like can be accommodated through the cooling cavity 70, so that the whole superconducting coil can be soaked by a cooling medium, and a good problem gradient is maintained. Meanwhile, the sizes and shapes of the third cavity 50, the second cavity 43 and the first cavity 33 may be set according to actual requirements, so that the total volume may be different from 10L to 300L. The third cavity 50, the second cavity 43, and the first cavity 33 may reduce an additional space for accommodating the outer coil 110 and the inner coil 120, and the entire superconducting coil may be immersed.

Therefore, the third cavity 50, the second cavity 43 and the first cavity 33 can significantly reduce the consumption of the cooling medium, thereby avoiding the injection of a large amount of cooling medium to soak the superconducting coil and reducing the cost. Therefore, the superconducting magnet 100 can adjust the amount of the cooling medium used according to actual requirements by controlling the volumes of the third cavity 50, the second cavity 43 and the first cavity 33, and thus high-level immersion can be realized by a small amount of the cooling medium. Therefore, the superconducting magnet 100 not only achieves the target of low liquid helium, but also does not limit the use requirements of a magnetic resonance sequence and the like.

In one embodiment, the superconducting magnet 100 further comprises an intermediate former 220, an inner former 230, a first cylindrical sealing sleeve 320, and two annular plates 310. The inner bobbin 230 is disposed in the accommodating space 810. The inner coil 120 is disposed on the inner coil frame 230. The middle bobbin 220 is disposed in the accommodating space 810. The middle bobbin 220 is disposed on a side of the inner bobbin 230 away from the central axis. The first cylindrical sealing cylinder 320 is disposed in the accommodating space 810. The first cylindrical sealing cylinder 320 is disposed on a side of the inner bobbin 230 close to the central axis. The two annular plates 310 are disposed between the first cylindrical sealing cylinder 320 and the intermediate bobbin 220. The middle bobbin 220, the first cylindrical sealing cylinder 320 and the two annular plates 310 surround to form the first cavity 33.

The inner coil 120 is formed by winding a superconducting wire around a mold having a predetermined size, and injecting resin. And then sequentially assembled to the inner cylindrical surface of the inner bobbin 230 through the outer cylindrical surface of the coil thereof. Meanwhile, a very tight and stable connection is formed between the inner coil 120 and the inner coil former 230 by pouring resin paste between the superconducting wire and the inner coil former 230, or the like. The two annular plates 310 are disposed at both ends of the middle bobbin 220. Meanwhile, the first cylindrical sealing cylinder 320 is also connected to the two annular plates 310, and the intermediate bobbin 220, the first cylindrical sealing cylinder 320 and the two annular plates 310 surround to form the first cavity 33. At this time, the first cavity 33 may accommodate the entire inner coil assembly, a tab connection line of the coil, and the like. Therefore, when the first cavity 33 is filled with the cooling medium, the entire inner coil assembly can be immersed, and uniform cooling can be achieved.

The middle coil former 220 and the inner coil former 230 may be made of metal materials, such as aluminum alloy or stainless steel, and may be tightly processed, and facilitate assembly, welding and sealing of the components. Alternatively, the intermediate bobbin 220 and the inner bobbin 230 may be made of epoxy resin, and the components may be connected by bonding. Meanwhile, on the premise of ensuring the structural strength, the size and thickness of the first cylindrical sealing cylinder 320 and the two annular plates 310 may be set to be thinner so as to reduce the gap between the first cylindrical sealing cylinder and the low temperature vessel 80 and the inner coil 120, thereby saving the cost.

The intermediate bobbin 220, the inner bobbin 230, and the first cylindrical sealing cylinder 320 are cylindrical structures that are symmetrical about a central axis. When the two annular plates 310 are respectively connected with the middle coil former 220 and the first cylindrical sealing cylinder 320 in a sealing manner, two ends of the two annular plates are connected in a sealing manner, so that the problem that the corners of the traditional superconducting magnet are difficult to weld is solved. Meanwhile, the two end parts are hermetically connected, so that the stress between the two end parts is uniform, and the problem of obvious stress concentration caused by the connection of the traditional superconducting magnet is solved. In addition, the intermediate bobbin 220, the inner bobbin 230, the two annular plates 310, and the first cylindrical sealing cylinder 320 are conveniently assembled and mounted by the structure and the connection manner therebetween.

In one embodiment, a plurality of connectors 250 are disposed between the inner bobbin 230 and the middle bobbin 220.

The inner bobbin 230 and the middle bobbin 220 are fixedly connected by the plurality of connectors 250, and have sufficient strength to resist the electromagnetic force applied to the coil. Meanwhile, the plurality of connection members 250 are uniformly dispersed between the inner bobbin 230 and the middle bobbin 220 so as to be axially and radially engaged, thereby ensuring the uniformity of the magnetic field of the entire magnet. The plurality of connectors 250 may be made of a material capable of resisting the shrink interference.

Meanwhile, when the plurality of connection members 250 are disposed on the middle bobbin 220, a certain distance is formed between the connection members and the welding portions at both ends of the middle bobbin 220, so as to reduce the influence caused by welding deformation and assembly error.

In one embodiment, the superconducting magnet 100 further comprises an intermediate former 220, a first cylindrical sealing sleeve 320, and two annular plates 310. The middle bobbin 220 is disposed in the accommodating space 810. The first cylindrical sealing cylinder 320 is disposed in the accommodating space 810. The first cylindrical sealing cylinder 320 is disposed on one side of the middle bobbin 220 close to the central axis. The two annular plates 310 are disposed between the first cylindrical sealing cylinder 320 and the middle bobbin 220, the first cylindrical sealing cylinder 320 and the two annular plates 310 surround to form the first cavity 33. The inner coil 120 is disposed on the middle bobbin 220 or the first cylindrical sealing cylinder 320.

In this embodiment, superconducting magnet 100 may not include inner former 230. The inner coil 120 may be directly disposed on the middle bobbin 220 or the first cylindrical sealing cylinder 320. At this time, the assembly surface between the inner coil 120 and the intermediate bobbin 220 or the first cylindrical sealing cylinder 320 may be an outer cylindrical surface or an inner cylindrical surface, so that the space of the inner bobbin may be fully utilized, and the cost may be saved.

In one embodiment, the superconducting magnet 100 further comprises an outer former 210 and a second cylindrical sealing barrel 410. The outer bobbin 210 is disposed in the accommodating space 810. The outer coil 110 is disposed on the outer bobbin 210. The outer bobbin 210 is disposed on a side of the middle bobbin 220 away from the central axis. The second cylindrical sealing cylinder 410 is disposed in the accommodating space 810. The second cylindrical sealing cylinder 410 is disposed on a side of the outer bobbin 210 away from the middle bobbin 220. And the second cylindrical sealing cylinder 410 is sealingly connected with the outer bobbin 210. The outer bobbin 210 and the second cylindrical sealing cylinder 410 surround to form the second cavity 43.

The outer coil 110 is disposed in the outer bobbin 210, and the second cylindrical sealing cylinder 410 is disposed on the outer layer of the outer coil 110. The cross section of the outer bobbin 210 is groove-shaped, the outer coil 110 is disposed in the groove, and the outer bobbin 210 is connected to the second cylindrical sealing cylinder 410 through two wire groove flanges 420. The second cylindrical sealing cylinder 410, the two-spool flange 420 and the outer bobbin 210 surround the second cavity 43. At this time, the second cavity 43 may accommodate the entire outer coil group, the joint connection wires of the coils, and the like. Therefore, when the second cavity 43 is filled with the cooling medium, the whole outer coil assembly can be soaked, and uniform cooling is realized.

The outer coil frame 210 and the second cylindrical sealing cylinder 410 may be made of metal materials, such as aluminum alloy or stainless steel, and can be tightly processed, and the assembly, welding and sealing of each component are facilitated. Alternatively, the outer bobbin 210 and the second cylindrical sealing cylinder 410 may be made of epoxy resin, and the components may be connected by bonding. Meanwhile, on the premise of ensuring the structural strength, the size and thickness of the second cylindrical sealing cylinder 410 may be set to be thinner so as to reduce the gap with the outer coil 110, thereby saving the cost. The outer coil former 210 is connected with the second cylindrical sealing barrel 410 through two wire groove flanges 420, so that the problem that the corners of a traditional superconducting magnet are difficult to weld is solved, and the superconducting magnet is convenient to assemble and install.

Meanwhile, when the second cylindrical sealing cylinder 410 is welded to the two-coil groove flange 420, a certain distance is left between the second cylindrical sealing cylinder and the outer coil 110, so that the influence caused by welding deformation and assembly error is reduced.

In one embodiment, the outer bobbin 210 and the middle bobbin 220 are connected by a bracket 240.

The bracket 240 is disposed between the outer bobbin 210 and the middle bobbin 220. The support 240, the outer bobbin 210, and the middle bobbin 220 are coaxially disposed and are symmetrical. The outer bobbin 210 and the middle bobbin 220 are fixedly connected by a bracket 240, and the strength is sufficient to resist the electromagnetic force applied to the coil. The holder 240, the outer bobbin 210, and the middle bobbin 220 are coaxially disposed and symmetrical so as to be axially and radially fitted to ensure magnetic field uniformity throughout the magnet. The material of the bracket 240 may be a material capable of resisting the shrink interference.

In one embodiment, a first port 510 is disposed between the first cavity 33 and the third cavity 50 for communicating the two cavities. And, the first interface 510 is used as a routing channel of the superconducting connection line of the inner coil 120.

The third cavity 50 is communicated with the second cavity 43 through a first pipeline 440. And a second port 520 is provided at a position where the third chamber 50 is connected to the first pipe 440, for communicating the third chamber 50 with the second chamber 43. Meanwhile, the first pipe 440 may serve as a routing path of the superconducting connection line of the outer coil former 210, and is configured to accommodate the superconducting connection line of the outer coil former 210. At this time, when the first cavity 33, the second cavity 43, the third cavity 50, and the connecting pipes therebetween are filled with the cooling medium, all of the coils, the coil joints, the superconducting switches, the low-temperature electronic devices, and the like can be immersed, so that uniform cooling can be achieved.

In one embodiment, the third cavity 50 is disposed on a side of the middle bobbin 220 away from the central axis, and may occupy less of the accommodating space 810. Meanwhile, the third cavity 50 is disposed at a position where the overall magnetic field is weak, so that the influence on the overall magnetic field can be avoided.

In one embodiment, the superconducting magnet 100 further comprises a cooling device 90. The refrigerating apparatus 90 is disposed on a side of the low temperature container 80 far from the accommodating space 810. The refrigerating device 90 is hermetically connected with the first cavity 33. The refrigerating device 90 is used for condensing and refluxing the cooling medium.

The refrigeration device 90 is a refrigerator. The refrigeration pole 60 of the refrigerator is communicated with the first cavity 33 through a third pipeline 610 and a third interface 620 to form a cooling medium condensation return channel. The refrigeration pole 60, the first cavity 33, the second cavity 43, and the third cavity 50 of the refrigerator form the sealed cooling cavity 70 through a plurality of interfaces and pipes. When part of the cooling medium is vaporized to a gas during normal operation, it rises to the top and is condensed back by the cold plate 60. When quench occurs, the cooling medium in the cooling cavity 70 absorbs the quench heat and rapidly vaporizes into hot gas, generating a pressure of several megapascals. After quenching, the refrigerant pole 60 continuously condenses the medium gas, gradually reflows, and finally reaches an initial state.

Referring to fig. 2, in one embodiment, the first cavity 33, the second cavity 43 and the third cavity 50 surround to form a cooling cavity 70. The cooling chamber 70 and the inner wall of the cryogenic vessel 80 enclose an outer chamber 73. The refrigerating device 90 is connected to the first chamber 33 through a third pipeline 610. Superconducting magnet 100 also includes an exhaust line 710 and a control valve 720. The exhaust line 710 is disposed in the third line 610 and is configured to communicate with the outer chamber 73. The control valve 720 is disposed in the exhaust line 710.

Wherein the communication between the cooling chamber 70 and the outer chamber 73 is achieved through the exhaust duct 710 and the third duct 610. Meanwhile, the opening pressure of the control valve 720 is set to be higher than the pressure of the cooling medium gas during normal operation, so that the cooling medium gas in the cooling chamber 70 can be released in advance when the magnet loses time. Due to the large volume of the outer chamber 73, the pressure of the cooling medium gas is now borne by the low-temperature container 80 through the exhaust line 710 and the control valve 720, so that the pressure in the cooling chamber 70 is significantly lower than the quench pressure when the exhaust line 710 and the control valve 720 are not provided.

Referring to fig. 3, in one embodiment, superconducting magnet 100 further includes a fourth conduit 740. One end of the fourth pipe 740 is connected to the third pipe 610. The other end of the fourth pipe 740 is connected to the second cavity 43.

The two ends of the fourth pipeline 740 are respectively connected with the second cavity 43 and the third pipeline 610, so that the end-to-end connection is realized, and a closed and annular cooling cavity 70 is formed. Therefore, through the cooling cavity 70 formed by the end-to-end connection, liquid nitrogen can circularly flow in the closed cavity, and a better cooling effect is realized.

Referring to fig. 4, in one embodiment, superconducting magnet 100 further includes a cooling device 90. The refrigerating device 90 is disposed on a side of the low temperature container 80 far from the accommodating space 810. The refrigerating device 90 is connected to the first chamber 33. And an opening 630 is formed at the connection position of the refrigerating device 90 and the first cavity 33.

The third pipe 610 connecting the refrigerating apparatus 90 and the first chamber 33 is opened by the opening 630. At this time, the cooling chamber 70 is in communication with the outer chamber 73. Therefore, the cooling medium in the cooling chamber 70 can directly enter the outer chamber 73 (i.e. the accommodating space 810 of the low temperature container 80) after being vaporized. Meanwhile, the cooling medium is vaporized and condensed by the cold pole 60 and flows back through the third pipe 610. By the simple configuration of the opening 630, the quench pressure is low.

In one embodiment, when the cooling medium is liquid helium, the conventional low-liquid helium magnet is often transported for a long time when the magnet is sent to a field due to the small amount of liquid helium, a small amount of liquid helium is quickly evaporated, the temperature of the magnet is continuously increased until the magnet reaches a normal temperature state, and at this time, the magnet needs to be precooled again.

However, during transportation, more liquid helium is filled in the outer cavity 73 (the remaining cavity space in the cryogenic container 80) in the superconducting magnet 100 to meet the requirement of long-distance transportation. Meanwhile, during short-distance transportation, a small amount of liquid helium can be filled into the cooling cavity 70 through the liquid helium in the outer cavity 73.

In one embodiment, the outer chamber 73 (the remaining chamber in the cryogenic container 80) may also be filled with a quantity of a high thermal capacity medium, such as liquid nitrogen or water. Upon pre-cooling of the magnet, the medium is cooled to solid ice. When the magnet is transported, the high heat capacity medium can absorb more heat, thereby greatly prolonging the transportation time. When the magnet is quenched, the high-heat-capacity medium also absorbs heat generated by quenching of the magnet, so that the temperature rise of the coil is slowed down, and the cooling time of the magnet is shortened.

In one embodiment, the cryogenic vessel 80 includes an inner vessel 820, an intermediate thermal shield 830, and an outer vacuum vessel 840. The cryogenic vessel 80 is a cryostat and the inner vessel 820, the intermediate thermal shield 830 and the outer vacuum vessel 840 are coaxially arranged.

In one embodiment, a closed cooling chamber 70 is formed by the first chamber 33, the second chamber 43, the third chamber 50 and the connecting pipes. The cooling cavity 70 is filled with a cooling medium, and can uniformly cool all coils, coil superconducting joints, superconducting switches, low-temperature electronic devices and the like. Therefore, the low temperature vessel 80 includes the intermediate heat shield 830 and the outer vacuum vessel 840, and the inner vessel 820 may not be included, so that the low temperature vessel 80 has a simple structure and is cost-effective.

In an embodiment, a magnetic resonance imaging system comprises a superconducting magnet 100 as described in any of the above embodiments. All coils, coil superconducting joints, superconducting switches, low-temperature electronic devices and the like can be uniformly cooled through the superconducting magnet 100, so that the superconducting magnet 100 keeps good magnetic field stability, and the imaging quality of a magnetic resonance system is improved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent application shall be subject to the appended claims.

Claims

1. A superconducting magnet, comprising:

a magnet coil assembly (10) including an outer coil (110) and an inner coil (120);

the low-temperature container (80) surrounds and forms an accommodating space (810);

a first cavity (33) disposed in the accommodating space (810), the inner coil (120) being disposed in the first cavity (33);

the second cavity (43) is arranged in the accommodating space (810), and the outer coil (110) is arranged in the second cavity (43);

the first cavity (33) is communicated with the second cavity (43), and cooling media are filled in the first cavity (33) and the second cavity (43);

the outer coil (110) is arranged in an outer coil frame (210) with a groove-shaped section, a second cylindrical sealing cylinder (410) is arranged on the outer layer of the outer coil (110), the outer coil frame (210) is connected with the second cylindrical sealing cylinder (410) in a sealing mode, and the outer coil frame (210) and the second cylindrical sealing cylinder (410) are surrounded to form the second cavity (43);

the first cavity (33) and the second cavity (43) are both annular cavities, and the second cavity (43) is positioned on the outer peripheral side of the first cavity;

the third cavity (50) is arranged in the accommodating space (810) and is positioned between the first cavity (33) and the second cavity (43), and the third cavity (50) is communicated with the first cavity (33) and the second cavity (43) respectively.

2. The superconducting magnet of claim 1, further comprising:

an inner coil frame (230) disposed in the accommodating space (810), the inner coil (120) being disposed on the inner coil frame (230);

the middle coil rack (220) is arranged in the accommodating space (810), and the middle coil rack (220) is arranged on one side, far away from the central axis, of the inner coil rack (230);

the first cylindrical sealing cylinder (320) is arranged in the accommodating space (810), and the first cylindrical sealing cylinder (320) is arranged on one side, close to the central shaft, of the inner coil frame (230);

two annular plates (310) disposed between the first cylindrical sealing cylinder (320) and the intermediate bobbin (220), the first cylindrical sealing cylinder (320), and the two annular plates (310) surrounding the first cavity (33).

3. The superconducting magnet of claim 1, further comprising:

the middle coil frame (220) is arranged in the accommodating space (810);

a first cylindrical sealing cylinder (320) disposed in the accommodating space (810), the first cylindrical sealing cylinder (320) being disposed on a side of the intermediate bobbin (220) close to a central axis;

two annular plates (310) disposed between the first cylindrical sealing cylinder (320) and the intermediate bobbin (220), the first cylindrical sealing cylinder (320), and the two annular plates (310) surrounding to form the first cavity (33);

the inner coil (120) is disposed on the intermediate bobbin (220) or the first cylindrical sealing cylinder (320).

4. The superconducting magnet of claim 2 or claim 3, further comprising:

the outer coil frame (210) is arranged in the accommodating space (810), the outer coil (110) is arranged on the outer coil frame (210), and the outer coil frame (210) is arranged on one side, away from the central shaft, of the middle coil frame (220);

the second cylindrical sealing cylinder (410) is arranged in the accommodating space (810), the second cylindrical sealing cylinder (410) is arranged on one side, away from the middle coil rack (220), of the outer coil rack (210), and the second cylindrical sealing cylinder (410) is connected with the outer coil rack (210) in a sealing mode;

the outer coil frame (210) and the second cylindrical sealing barrel (410) surround to form the second cavity (43).

5. The superconducting magnet of claim 2 or claim 3, further comprising:

the refrigerating device (90) is arranged on one side, far away from the accommodating space (810), of the low-temperature container (80), the refrigerating device (90) is connected with the first cavity (33) in a sealing mode, and the refrigerating device (90) is used for condensing and refluxing cooling media.

6. The superconducting magnet of claim 5, wherein the first cavity (33), the second cavity (43), and the third cavity (50) enclose to form a cooling cavity (70), the cooling cavity (70) encloses with an inner wall of the cryogenic vessel (80) to form an outer cavity (73), the refrigerating device (90) is connected with the first cavity (33) through a third conduit (610), the superconducting magnet further comprising:

-an exhaust line (710) arranged in said third line (610) for communicating with said outer chamber (73);

and the control valve (720) is arranged on the exhaust pipeline (710).

7. The superconducting magnet of claim 2 or claim 3, further comprising:

the refrigerating device (90) is arranged on one side, far away from the accommodating space (810), of the low-temperature container (80), the refrigerating device (90) is connected with the first cavity (33), and an opening (630) is formed in the position where the refrigerating device (90) is connected with the first cavity (33).

8. A magnetic resonance imaging system, comprising:

a low-temperature container (80) having an accommodating space (810);

at least one first cavity (33) arranged in the low-temperature container (80), wherein a superconducting coil is fixed in the first cavity (33);

at least one second cavity (43) which is arranged in the low-temperature container (80) and is positioned at the outer periphery side of the first cavity (33), a superconducting coil is fixed in the second cavity (43), and the second cavity (43) is communicated with the first cavity (33);

a refrigeration device (90) arranged on the cryogenic container (80) and thermally coupled with at least one cavity in the accommodating space (810) of the cryogenic container (80);

a refrigeration pole (60) of the refrigeration device (90) extends into the accommodating space (810) of the low-temperature container (80), and the refrigeration pole (60) is thermally coupled with the first cavity (33);

9. The magnetic resonance imaging system of claim 8, further comprising:

at least one coil former disposed inside the cryogenic vessel (80) for fixing the superconducting coil, and forming a part of the first cavity (33) or the second cavity (43), a gap being formed between the first cavity (33) or the second cavity (43) and the superconducting coil, the gap being filled with a cooling medium.