CN114974796A

CN114974796A - Superconducting coil embedded in inner skeleton and manufacturing method and system thereof

Info

Publication number: CN114974796A
Application number: CN202210611753.0A
Authority: CN
Inventors: 王亚伟; 薛文博; 翁昉倞; 李建威
Original assignee: Shanghai Jiaotong University
Current assignee: Shanghai Jiaotong University
Priority date: 2022-05-31
Filing date: 2022-05-31
Publication date: 2022-08-30
Anticipated expiration: 2042-05-31
Also published as: CN114974796B

Abstract

The invention provides a superconducting coil embedded in an inner skeleton and a manufacturing method and a system thereof, wherein the superconducting coil comprises: a lower skeleton, an inner skeleton and an upper skeleton; the center of the lower framework is provided with a central bulge which provides central support for the coil; a plurality of annular grooves are formed around the lower framework and matched with the inner framework; an annular bulge is arranged on one circle of the periphery of the upper framework to provide mechanical support for the wound coil; along the height direction, the following are sequentially from top to bottom: an upper framework, an inner framework and a lower framework; along the radius direction, from inside to outside are: the central bulge of the lower framework, the inner framework and the annular bulge of the upper framework; on the basis of the lower framework, the inner framework is embedded into the groove of the lower framework, and the upper framework is stacked on the lower framework. The inner skeleton which is tightly contacted with the superconducting tape is embedded in the winding process, so that reliable mechanical support can be provided for the superconducting tape; when the superconducting coil has a quench fault, the inner skeleton can also play a role in shunting and heat conduction, and the stability of the superconducting coil is greatly improved.

Description

Superconducting coil embedded in inner skeleton and manufacturing method and system thereof

Technical Field

The invention relates to the technical field of coil manufacturing, in particular to a superconducting coil embedded into an inner framework and a manufacturing method and system thereof.

Background

The superconductor can keep zero resistance characteristic only in a superconducting state, and when any parameter of the temperature, the magnetic field and the current of the superconductor exceeds a critical value, the superconductor suddenly loses the superconducting characteristic and enters a resistive normal state from the superconducting state, which is called as quench. The quenching process of the superconductor generates a large amount of heat, once the quenching occurs, if the quenching is not found in time, effective protection measures are taken, and the superconductor can be irreversibly damaged.

The high-temperature superconducting tape is a coated conductor produced by a multi-layer laminating packaging method by using a vacuum coating technology, and is shown in figure 1. When the temperature is lower than the critical temperature, the superconducting tape exhibits zero resistance characteristics, and can transmit a large current with almost no loss. By means of the characteristic of large carrying capacity of the high-temperature superconducting tape, the superconducting magnet wound by the high-temperature superconducting tape can generate a strong magnetic field and has small loss, so that the superconducting tape is widely applied to environments requiring the strong magnetic field, such as superconducting motors, magnetic levitation and the like.

The high temperature superconducting coil is a coil wound by a high temperature superconducting tape or a high temperature superconducting cable, and its geometry includes both a pancake coil and a solenoid coil, as shown in fig. 2.

The superconducting tape itself is weak in mechanical properties and is easily damaged upon bending. When a superconducting magnet consisting of superconducting coils works, due to the fact that background magnetic field is strong, working current is large, and a superconducting strip is acted by large ampere force, the strip can be deformed, and can be damaged seriously, and irreversible damage is caused to the whole magnet. In addition, when the temperature is changed to the low-temperature environment from the normal temperature, the superconducting tape and the coil framework have different thermal expansion coefficients, so that the tape can be tightened or loosened, and even the serious consequences of magnet deformation and tape snapping can be caused. Therefore, how to reinforce the superconducting strip while ensuring the compactness of the coil structure and preventing the superconducting strip from deforming due to expansion and contraction and ampere force in a strong magnetic field becomes a key problem of the application of the superconducting coil in a strong field magnet.

Patent document CN103065756B (application number: CN201310023794.9) discloses a bayonet type metal superconducting magnet skeleton and a manufacturing method thereof, the superconducting magnet skeleton is formed by sandwiching a plurality of annular metal single skeletons which are mutually overlapped by an upper pressing plate and a lower pressing plate, and is separated into a plurality of superconducting coil winding cake areas by an intermediate insulating partition plate; each annular metal monomer framework is provided with one or more openings, the openings are linear bayonets or self-locking bayonets, and insulating materials are filled and fixed in the gaps of the openings so that the metal monomer framework becomes a non-fully-conductive whole circular framework; a partition plate groove is formed in the side face of the partial annular metal monomer framework, and the insulating partition plate is clamped in the partition plate groove; and a plurality of layers of copper belts with insulating outer skins are wound on the inner wall of the metal monomer framework of each winding area.

The main differences between the patent and the invention are that: the object of the present invention is to provide a superconducting magnet, which is a stacked structure of a plurality of superconducting coils, and a single coil in the superconducting magnet. The core content of the patent is different, the open-loop coil metal framework is fastened in a bayonet mode, and the core content of the invention is that the coil structure is reinforced by inserting the annular inner framework to share the stress on a part of the superconducting strip. The invention can not only improve the mechanical strength of the coil, but also conduct heat and shunt in time when the coil loses overtime, thereby improving the electrical and thermal properties of the coil, which is not possessed by the published patent.

Patent document CN106504849A (application number: CN201611156310.8) discloses a high-temperature superconducting coil former, which includes three coil formers, namely a first coil former, a second coil former and a third coil former, arranged in sequence from inside to outside; each coil rack comprises a coil rack body for winding a coil, and an upper flange and a lower flange are respectively arranged at two ends of the coil rack body; the upper flange is provided with two lead-out grooves which are used for leading out interfaces of the coils; the high-temperature superconducting coil framework further comprises two insulating plates, wherein an electrode is fixed on each insulating plate and used for welding the interface of the coil.

The main differences between the patent and the invention are that: the patent is directed to a series structure of a plurality of coils, and the present invention is directed to a bobbin structure of a single coil, i.e., a "bobbin body" referred to in the patent publication. The invention is to embed the ring-shaped inner frame during the coil winding process, and the coil frame body in the patent is not processed similarly. The core content is different, the core content of the patent is a combined structure of three coil formers, when a certain coil fails, the coil can be in short circuit, and the remaining two coils are used for continuing working; the core content of the invention is that the inner skeleton is embedded in the winding process to provide a support structure for the superconducting tape, and the superconducting tape can also play roles of shunting and heat conduction, which is completely different from the published patent.

Patent document CN107248444A (application No.: CN201710298939.4) discloses an encapsulated non-insulated superconducting coil comprising: the wire coil comprises a wire coil body (1) and a filling and encapsulating structure (2). The filling and encapsulating structure (2) partially or wholly encapsulates the outside of the wire coil body and partially or wholly fills the inter-turn gap of the wire coil body (1). The material used to fill the encapsulating structure is one or any of a variety of non-insulating materials.

The main differences between the patent and the invention are that: the core content of the patent is different, and the wound coil is subjected to solder pouring and packaging to form an encapsulated coil structure, so that the electrical, mechanical and thermal properties of the superconducting coil are improved; in the process of winding the coil, the invention provides support for the strip by embedding the annular inner framework and optimizes the performance of the coil. The coils of this patent need to be filled with encapsulating material after winding, during which the coil tape is heated again, with the risk of damage to the superconducting tape. The coil is formed after being wound, and no extra encapsulation is needed.

Disclosure of Invention

In view of the shortcomings in the prior art, it is an object of the present invention to provide a superconducting coil embedded in an inner former, and a method and system for manufacturing the same.

According to the present invention, there is provided an endoskeleton-embedded superconducting coil, comprising: a lower skeleton, an inner skeleton and an upper skeleton;

a central bulge is arranged in the center of the lower framework to provide central support for the coil;

a plurality of annular grooves are formed around the lower framework and matched with the inner framework;

an annular bulge is arranged on one circle of the periphery of the upper framework to provide mechanical support for the wound coil;

along the height direction, the following are sequentially from top to bottom: an upper framework, an inner framework and a lower framework;

along the radius direction, from inside to outside are: the central bulge of the lower framework, the inner framework and the annular bulge of the upper framework;

on the basis of the lower framework, the inner framework is embedded into the groove of the lower framework, and the upper framework is stacked on the lower framework.

Preferably, the lower framework is provided with a threaded hole for assembling with the upper framework;

the upper framework is of a disc shape, and threaded holes are formed in the upper framework and used for being assembled with the lower framework.

Preferably, the inner frame is a ring-shaped structure, the width of the inner frame is slightly larger than the width of the strip, and an opening with a preset angle is formed in the inner frame to provide a channel for winding the strip.

Preferably, the annular bulge is provided with an opening of 20-30 degrees, so as to provide a path for winding the strip.

The method for manufacturing the superconducting coil embedded into the inner skeleton comprises the following steps:

step 1: fixing one end of the strip on a central convex part of the lower framework, and then starting winding along the opposite direction;

and 2, step: when the outer diameter of a coil in winding is equal to the inner diameter of a groove of a lower framework, vertically inserting an annular inner framework into the groove along the normal direction of the surface of the lower framework to enable a wound superconducting strip to be tightly attached to the inner side of the inner framework, then winding the strip on the outer side of the inner framework from the inner side of the inner framework through an opening, and continuously winding the strip along the outer side;

and step 3: returning to the step 2 to continue to execute, inserting an annular inner framework at the corresponding groove when the number of turns is preset for each winding until the winding is finished;

and 4, step 4: and assembling with the coil upper framework to form a finished coil.

Preferably, the distance between the grooves is adjusted as required, the narrower the distance between the grooves is, the more the inner frameworks are inserted during winding, and the fewer the turns of the strip material between the adjacent inner frameworks are.

Preferably, the inner framework material is a metal material or an insulating material, and the electrical conductivity and the thermal conductivity of the metal material meet preset requirements;

and a liquid guide groove is formed in the inner framework and used for enabling a refrigerant to circulate in the coil, so that the refrigeration effect is improved.

The superconducting coil manufacturing system embedded into the inner skeleton provided by the invention comprises the following components:

module M1: fixing one end of the strip on a central convex part of the lower framework, and then starting winding along the opposite direction;

module M2: when the outer diameter of a coil in winding is equal to the inner diameter of a groove of a lower framework, vertically inserting an annular inner framework into the groove along the normal direction of the surface of the lower framework to enable a wound superconducting strip to be tightly attached to the inner side of the inner framework, then winding the strip on the outer side of the inner framework from the inner side of the inner framework through an opening, and continuously winding the strip along the outer side;

module M3: returning to the module M2 to continue to operate, and inserting an annular inner framework at the corresponding groove when winding the preset number of turns until the winding is finished;

module M4: and assembling with the coil upper framework to form a finished coil.

Compared with the prior art, the invention has the following beneficial effects:

(1) according to the superconducting coil process embedded into the inner framework, provided by the invention, the inner framework not only can provide mechanical support for a superconducting strip, but also can play a role in heat conduction and shunting, so that the mechanical, electrical and thermal properties of the superconducting coil can be obviously improved, and the application prospect of the superconducting coil in a strong-field magnet is expanded;

(2) in the process of winding the coil, an annular metal inner framework is inserted every several turns of the coil, and the inner framework can be embedded into the lower framework of the coil and is tightly contacted with the superconducting strip, so that mechanical support is provided for the strip;

(3) the metal inner framework has better electrical conductivity and thermal conductivity, so that the inner framework can also play a role in shunting when a quench fault occurs, can timely conduct heat generated on the superconducting tape, greatly improves the robustness of the superconducting coil, and has great value for promoting the industrial application of the high-temperature superconducting coil.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic view showing a structure of a high temperature superconducting tape;

FIG. 2 is a schematic of the geometry of a high temperature superconducting coil; FIG. 2a is a pancake coil and FIG. 2b is a solenoid coil;

FIG. 3 is a schematic diagram of a bobbin structure; FIG. 3a is a schematic view of the lower frame structure; FIG. 3b is a schematic illustration of the inner frame structure; FIG. 3c is a schematic view of the upper skeleton structure;

FIG. 4 illustrates the assembly between bobbin assemblies;

fig. 5 is a schematic diagram of a winding process of a superconducting coil.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

Example (b):

the superconducting coil proposed by the present invention is composed of 3 parts, including: a lower frame 100, an inner frame 200, and an upper frame 300. Fig. 3 is a schematic view of the bobbin, and fig. 4 is a schematic view of an assembly manner between the bobbins. Along the height direction, the following are sequentially from top to bottom: upper frame 300, inner frame 200, lower frame 100. The lower frame 100 is used as a base, the inner frame 200 is inserted into the groove 102 of the lower frame 100, and the upper frame 300 is stacked on the lower frame 100. Along the radius direction, from inside to outside are: a central bulge 101 of the lower framework, an inner framework 200 and an annular bulge 301 of the upper framework.

The center of the coil lower bobbin 100 is provided with a central bulge 101 for providing central support for the coil. A plurality of annular grooves 102 are formed in the periphery of the lower framework 100 and can be matched with the inner framework 200, and when the outer diameter of a coil in winding is equal to the inner diameter of the grooves 102, the annular metal inner framework 200 is embedded into the grooves 102 to fix the wound strip. An inner frame 200 is inserted every time a groove is reached during the winding process until each groove 102 is embedded in the inner frame. The distance between the grooves 102 can be adjusted as required, and the narrower the distance between the grooves 102 is, the more the inner frames 200 are inserted during winding, and the fewer the number of turns of the strip between the adjacent inner frames. The lower frame 100 is provided with a screw hole 103 for assembling with the upper frame 300.

The coil bobbin 200 is a ring structure with a width slightly larger than the width of the strip, and has an opening 201 with a certain angle for providing a channel for the strip to be wound. The material of the inner frame 200 may be a good conductor such as copper and silver, an insulating material, or a combination of multiple layers of materials such as copper and stainless steel.

The upper framework 300 of the coil is in a disc shape, and an annular bulge 301 is arranged on one circle of the periphery of the upper framework, so that mechanical support can be provided for the wound coil. The annular projection 301 is provided with an opening 302 of 20-30 degrees, which provides a path for the wound strip. The upper frame 300 is provided with a screw hole 303 for assembling with the lower frame 100. The lower framework and the upper framework of the coil can be made of metals such as copper, silver and the like, and can also be made of insulating materials with better mechanical properties such as epoxy resin and the like.

The winding mode of the superconducting coil containing the metal inner framework is as follows:

1) the strip is first fixed at one end to the central raised portion 101 of the lower frame 100 and then winding is started in the opposite direction (counterclockwise in fig. 3).

2) Whenever the outer diameter of the coil being wound is equal to the inner diameter of the groove 102 of the lower bobbin, the annular inner bobbin 200 is inserted vertically into the groove 102 in the direction of the normal line of the surface of the lower bobbin 1 so that the superconducting tape 104 already wound is closely attached to the inner side of the inner bobbin 2. The tape 104 is then passed through the opening 201 from the inside of the inner frame 200, wound around the outside of the inner frame 200, and wound around the outside, as shown in fig. 5.

3) And (3) repeating the step (2), and inserting an annular inner framework 200 at the corresponding groove 102 every few turns of winding until the winding is finished. The wound coil has a plurality of inner skeleton structures distributed on both sides of the superconducting tape 104 to provide support for the tape.

4) And finally assembled with the coil upper bobbin 300 to form a finished coil.

The assembly method comprises the following steps:

(1) the assembly is carried out through the arranged threaded

holes

103 and 303;

(2) the lower surface of the annular protrusion 301 of the upper bobbin 300 is adhered to the lower bobbin 200 by a connecting member, such as a double-sided insulating tape.

The inner skeleton can be made of copper, silver or other metal materials with better electric conductivity and thermal conductivity.

The inner frame may also be made of an insulating material such as epoxy resin.

The inner skeleton may be a single layer or a combination of layers of materials, such as copper and stainless steel.

The inner frame can be provided with a liquid guide groove, so that the refrigerant can conveniently circulate in the coil, and the refrigeration effect is further improved.

According to the superconducting coil process embedded into the inner framework, the metal inner framework is in close contact with the superconducting tape in terms of mechanical property, so that reliable mechanical support can be provided for the superconducting tape, and the superconducting tape is prevented from being deformed under the action of ampere force in a strong magnetic field; in the aspect of electrical performance, the inner framework has electrical conductivity, when the superconducting coil has a quench fault, the working current can be automatically shunted to the inner framework, the current on the superconducting tape is reduced in time, and the tape is prevented from being damaged by overcurrent; in the aspect of thermal property, the thermal conductivity of the inner framework is better, the heat generated on the superconducting tape can be conducted in time, and the local over-high temperature of the coil is prevented. In a preferable scheme, the inner framework is provided with a liquid guide groove, and a refrigerant can circularly flow through the liquid guide groove, so that the refrigeration effect of the superconducting coil is further improved.

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", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present application.

Those skilled in the art will appreciate that, in addition to implementing the systems, apparatus, and various modules thereof provided by the present invention in purely computer readable program code, the same procedures can be implemented entirely by logically programming method steps such that the systems, apparatus, and various modules thereof are provided in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system, the device and the modules thereof provided by the present invention can be considered as a hardware component, and the modules included in the system, the device and the modules thereof for implementing various programs can also be considered as structures in the hardware component; modules for performing various functions may also be considered to be both software programs for performing the methods and structures within hardware components.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.

Claims

1. A superconducting coil embedded in an endoskeleton, comprising: a lower frame (100), an inner frame (200) and an upper frame (300);

a central bulge (101) is arranged in the center of the lower framework (100) and provides central support for the coil;

a plurality of annular grooves (102) are formed around the lower framework (100) and matched with the inner framework (200);

an annular bulge (301) is arranged on one circle of the periphery of the upper framework (300) to provide mechanical support for a wound coil;

along the height direction, the following are sequentially from top to bottom: an upper framework (300), an inner framework (200) and a lower framework (100);

along the radius direction, from inside to outside are: a central bulge (101) of the lower framework, an inner framework (200) and an annular bulge (301) of the upper framework;

based on the lower framework (100), the inner framework (200) is embedded in the groove (102) of the lower framework (100), and the lower surface of the annular bulge (301) on the upper framework (300) is attached to the upper surface of the lower framework (200).

2. The endoskeleton-embedded superconducting coil of claim 1, wherein the lower bobbin (100) is formed with a threaded hole (103) for fitting with an upper bobbin (300);

go up skeleton (300) and be the disc type, go up skeleton (300) and go up and open threaded hole (303) for with skeleton (100) assembly down.

3. The endoskeleton-embedded superconducting coil of claim 1, wherein the endoskeleton (200) is a ring-shaped structure having a width slightly greater than a width of the tape, and wherein a predetermined angle of the opening (201) is present to provide a passage for the wound tape.

4. The endoskeleton-embedded superconducting coil of claim 1, wherein the annular projection (301) has a 20-30 ° opening (302) to provide a path for a wound tape.

5. A method for manufacturing a superconducting coil embedded in an inner skeleton is characterized by comprising the following steps:

step 1: fixing one end of a strip on a central bulge (101) of a lower framework (100), and then starting winding along the opposite direction;

step 2: when the outer diameter of a coil in winding is equal to the inner diameter of a groove (102) of a lower framework, an annular inner framework (200) is vertically inserted into the groove (102) along the normal direction of the surface of the lower framework (100), so that a wound superconducting tape (104) is tightly attached to the inner side of the inner framework (200), then the tape passes through an opening (201) from the inner side of the inner framework (200), is wound on the outer side of the inner framework (200), and is continuously wound along the outer side;

and step 3: returning to the step 2 to continue to execute, inserting an annular inner framework (200) at the corresponding groove (102) every time when the preset number of turns is wound until the winding is finished;

and 4, step 4: and assembling with the coil upper framework (300) to form a finished coil.

6. The method for manufacturing a superconducting coil embedded in an inner frame as claimed in claim 5, wherein the distance between the grooves (102) is adjusted as required, and the narrower the distance between the grooves (102), the more the inner frames (200) are inserted during winding, the fewer the number of turns of the tape between the adjacent inner frames (200).

7. The method for manufacturing a superconducting coil embedded in an inner frame according to claim 5, wherein the inner frame material is a metal material or an insulating material, and the electrical conductivity and the thermal conductivity of the metal material meet preset requirements;

8. A system for fabricating a superconducting coil embedded in an inner former, comprising:

module M1: fixing one end of a strip on a central bulge (101) of a lower framework (100), and then starting winding along the opposite direction;

module M2: when the outer diameter of a coil in winding is equal to the inner diameter of a groove (102) of a lower framework, an annular inner framework (200) is vertically inserted into the groove (102) along the normal direction of the surface of the lower framework (100), so that a wound superconducting strip (104) is tightly attached to the inner side of the inner framework (200), then the strip passes through an opening (201) from the inner side of the inner framework (200), is wound on the outer side of the inner framework (200), and continues to be wound along the outer side;

module M3: returning to the module M2 to continue to operate, inserting an annular inner framework (200) at the corresponding groove (102) for each preset number of turns of winding until the winding is finished;

module M4: and assembling with the coil upper framework (300) to form a finished coil.

9. The system for manufacturing a superconducting coil embedded in an inner frame as claimed in claim 8, wherein the distance between the grooves (102) is adjusted as required, and the narrower the distance between the grooves (102), the more the inner frame (200) is inserted during winding, the fewer the number of turns of the tape between the adjacent inner frames (200).

10. The system for manufacturing a superconducting coil embedded in an inner frame according to claim 8, wherein the material of the inner frame is a metal material or an insulating material, and the electrical conductivity and the thermal conductivity of the metal material meet preset requirements;