A superconducting coil structure with stepped end armored conductor layers

Abstract

The present invention discloses an end-stepped armored conductor layer superconducting coil structure. It belongs to the field of superconducting conductor layer coils, and includes coil windings, insulation, helium inlet and outlet, special-shaped transition bend outlet ends, outlet end annular locking mechanism and connector terminals. The coil windings provide a magnetic field, and include inner sub-coil windings and outer sub-coil windings. The coil windings form end steps through different turns, and the other end is flat to ensure that the flow channels are of equal length. The helium inlet and outlet are used to circulate liquid helium so that the conductor maintains a low-temperature superconducting state. The insulation consists of inter-turn insulation and inter-layer insulation. The special-shaped transition bend outlet ends are used to lead the conductor upward from the winding. The connector terminals are used to connect the sub-coils in series and connect the power supply. The outlet end annular locking mechanism plays the role of fixing the special-shaped transition bend outlet ends and locking the windings.

Description

Technical Field

[0001] The invention relates to the technical field of superconducting conductor layer coils, in particular to an end-stepped armored conductor layer superconducting coil structure. Background Art

[0002] Armored conductor layer superconducting coils are an application in superconducting electromagnetic technology, especially in achieving the generation of strong magnetic fields. They are widely used in many fields, including magnetic resonance imaging (MRI), particle accelerators and magnetic confinement nuclear fusion reactors. The superconducting materials commonly used in armored conductor layer superconducting coils are low-temperature superconducting materials such as niobium titanium (NbTi) and niobium tin (Nb3Sn). After reaching the low-temperature superconducting state, these materials can carry extremely high-density currents, generate strong magnetic fields, and have very low energy loss.

[0003] In nuclear fusion research, a strong and stable magnetic field is the key to achieving magnetic confinement fusion; in particle physics research, a high-intensity magnetic field is a necessary condition for the normal operation of particle accelerators; in the field of high-performance high-magnetic field devices, armored conductor layer superconducting coils produce a magnetic field intensity far greater than that of conventional magnets, and their magnetic fields have high stability, which is crucial for scientific research that requires precise control of experimental conditions. In the existing technology, there are no superconducting coils with high field strength and high uniformity magnetic fields that meet engineering requirements. Summary of the invention

[0004] The purpose of the present invention is to propose an end-stepped armored conductor layer superconducting coil for providing a high-field strength and high-uniformity magnetic field that meets specific engineering requirements.

[0005] The technical solution of the present invention is as follows: an end-stepped armored conductor layer superconducting coil structure, including coil windings, insulation, helium inlet and outlet, special-shaped transition bend outlet head, outlet head annular locking mechanism and connector terminals;

[0006] The coil winding provides a magnetic field, and includes an inner sub-coil winding and an outer sub-coil winding;

[0007] Insulation includes turn-to-turn insulation and interlayer insulation. Turn-to-turn insulation is used to insulate the conductors between turns of the coil; interlayer insulation is used to adjust the radial dimensions of the coil during winding.

[0008] The helium inlet and outlet are used to circulate liquid helium to keep the conductor in a low-temperature superconducting state;

[0009] The special-shaped transition bent lead is used to lead the conductor vertically upward from the coil winding;

[0010] The annular locking mechanism of the outlet is used to fix the outlet of the special-shaped transition bend;

[0011] The connector terminal is used to connect to a power source to energize the superconducting coil; and is used to connect the inner sub-coil winding and the outer sub-coil winding.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] The end of the layered superconducting coil with stepped armored conductor of the present invention is stepped due to the different turns of the coil winding from the inside to the outside, so that the end can provide a magnetic field that meets the needs of specific projects; the transition section between the layers of the coil winding is composed of a small arc section and a straight section, so that the helium inlet and outlet are welded on the straight section, thereby ensuring the structural stability of the helium inlet and outlet, and the helium inlet and outlet are configured in a specific layer of the coil winding to ensure that the liquid helium flow channel is of equal length; the terminal is led out through the special-shaped transition bend, and the annular locking mechanism of the wire head is welded on the inner and outer sides of the special-shaped transition bend and the previous turn of the conductor armor, thereby offsetting the conductor rebound force in the layered coil winding, reducing the multi-axis stress amplitude of the special-shaped transition bend under electromagnetic conditions, and maintaining the stability of the coil structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is an overall front view of the armored conductor layer superconducting coil of the present invention;

[0015] Figure 2 This is an overall axial view of the armored conductor layer superconducting coil of the present invention;

[0016] Figure 3 It is a top view of the transition section between layers of the layered superconducting coil conductor;

[0017] Figure 4 This is a front view of the helium inlet and outlet structure;

[0018] Figure 5 It is a view of the special-shaped transition bend outlet and the outlet ring locking mechanism axis.

[0019] In the figure,

[0020] 1-coil winding, 2-insulation, 3-helium inlet and outlet, 4-special-shaped transition bend outlet, 5-outlet ring locking mechanism, 6-connector terminal;

[0021] 101-inner sub-coil winding, 102-outer sub-coil winding;

[0022] 201-turn insulation, 202-layer insulation;

[0023] 501-inner connecting plate, 502-outer connecting plate, 503-long connecting section. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other. To achieve the above-mentioned purpose, the present invention adopts the following technical scheme.

[0025] like Figure 1 , Figure 2 As shown, the present invention discloses an end-stepped armored conductor layer superconducting coil structure, comprising a coil winding 1, insulation 2, a helium inlet and outlet 3, a special-shaped transition bend outlet head 4, an outlet head annular locking mechanism 5, and a connector terminal 6.

[0026] The coil winding 1 includes twelve layers of conductors. The coil winding 1 is composed of an inner sub-coil winding 101 and an outer sub-coil winding 102. The end is stepped from the inside to the outside through different numbers of turns. The inner sub-coil winding 101 and the outer sub-coil winding 102 each have six layers of conductors. The inner sub-coil winding 101 is six layers from the innermost layer to the outermost layer, and the outer sub-coil winding 102 is from the seventh layer to the twelfth layer. The single-layer conductors of the coil winding 1 are closely adjacent in a spiral shape. Since it is formed by continuous winding, after the single-layer conductor is wound, the starting point of the winding of the next layer of conductor is the winding completion point of the previous layer of conductor, and then the winding is carried out in the opposite direction of the winding direction of the previous layer of conductor. The inner sub-coil winding 101 and the outer sub-coil winding 102 are connected by the connector terminal 6. A single sub-coil winding has six layers from the inside to the outside. The cross-layer segment between layers is tangent to the large arc segment of the wound conductor through a straight line segment, and then tangent to the large arc segment of the next layer of conductor through a tangent small arc segment, thereby completing the transition between layers.

[0027] The insulation 2 includes inter-turn insulation 201 and inter-layer insulation 202, wherein the inter-turn insulation 201 is formed by wrapping a glass ribbon, and the thickness of the inter-turn insulation 201 around the conductor is 0.9 mm. The inter-layer insulation 202 is located between the layers of the coil winding 1 conductor, and its width is determined according to the number of turns of each layer of the coil winding 1, and its thickness is about 1 mm. The specific value is determined according to the required adjustment amount of the radius size of each layer of the coil winding 1.

[0028] like Figure 3 , Figure 4 As shown, due to the limitation of the narrow surface size of the conductor, the helium inlet and outlet 3 is designed to be in a runway shape, thereby increasing the flow rate of liquid helium. Before the transition straight line segments between the conductor layers from the second layer to the third layer and from the fourth layer to the fifth layer of each sub-coil winding of the coil winding 1 are wound, the helium inlet and outlet 3 are opened and welded.

[0029] like Figure 5As shown, the special-shaped transition bend outlet terminal 4 is located at the innermost and outermost ends of the inner sub-coil winding 101 and the outer sub-coil winding 102 of the coil winding 1, that is, the innermost layer of the inner sub-coil winding 101 is provided with a special-shaped transition bend outlet terminal 4; the outermost layer of the inner sub-coil winding 101 is provided with a special-shaped transition bend outlet terminal 4; the innermost layer of the outer sub-coil winding 102 is provided with a special-shaped transition bend outlet terminal 4; the outermost layer of the outer sub-coil winding 102 is provided with a special-shaped transition bend outlet terminal 4, which is in the shape of a 90-degree arc leading out from the end of the coil winding 1, and on the basis of the 90-degree arc, an arc bending is performed that is consistent with the inner diameter of the conductor on the same layer, thereby forming a special-shaped transition bend shape, and the special-shaped transition bend outlet terminal 4 is led out vertically upward, and each special-shaped transition bend outlet terminal 4 is parallel, and the terminal height is consistent.

[0030] like Figure 5 As shown, the outlet head annular locking mechanism 5 is welded at the special-shaped transition bend and the narrow surface of the previous conductor armor. In order to prevent welding deformation during welding, the weld is segmented and alternating, thereby reducing the stress effect during welding cooling. The outlet head annular locking mechanism 5 component welded on the inner side of the special-shaped transition bend is the inner connecting plate 501, which is mainly used to fix the outlet head 4 of the special-shaped transition bend and reduce the multi-axial stress amplitude of the outlet lead-out section. The outlet head annular locking mechanism 5 component welded on the outer side of the special-shaped transition bend is the outer connecting plate 502, and the outlet head annular locking mechanism 5 component welded on the narrow surface of the previous conductor armor is the long strip connecting section 503, and its weld is also segmented and alternating. The radius of the inner connecting plate 501, the outer connecting plate 502 and the long strip connecting section 503 is consistent with the conductor radius of the layer where they are located. The conductor rebound force in the coil winding 1 is offset by locking the long strip connecting section 503, thereby ensuring the structural stability of the coil.

[0031] The connector terminal 6 is located at the lead-out terminal of the special-shaped transition bend lead end 4. The connector terminal 6 is a box-type connector terminal, which is made by welding a stainless steel plate and an oxygen-free copper composite plate. After the sub-coil windings are assembled, the connector terminals 6 outside the inner sub-coil winding 101 and the connector terminals 6 inside the outer sub-coil winding 102 are overlapped to form a double connector. The connector terminals 6 inside the inner sub-coil winding 101 and the connector terminals 6 outside the outer sub-coil winding 102 are used to connect to the power supply to energize the armored conductor layer superconducting coil.

[0032] The coil winding 1 includes an inner sub-coil winding 101 and an outer sub-coil winding 102. The coil winding 1 has twelve layers of conductors, and a single sub-coil winding has six layers of conductors. The armored superconducting conductor is composed of a Nb3Sn superconducting cable and an external stainless steel armor. The cross section of the conductor is rectangular, with a length of 24.6 mm and a width of 14.8 mm. The four corners are rounded with R4.5 mm. The armor material is 316LN stainless steel with a thickness of 2.5 mm. The inside of the armor is a high-performance Nb3Sn superconducting cable. Due to the different number of turns of each layer of the conductor, the upper end of the coil winding is stepped. The armor is a hollow structure with a rectangular cross section, and the inside of the armor cross section is a Nb3Sn superconducting cable.

[0033] The insulation 2 includes turn-to-turn insulation 201 and interlayer insulation 202, both of which are made of high-temperature resistant carbon-removing glass fiber tape. Before the coil is wound, the turn-to-turn insulation 201 is spirally wrapped on the armored conductor in three and a half layers. During the coil winding process, the interlayer insulation 202 is laid between the layers of the coil. If arc discharge occurs in the superconducting coil, heat will be generated, thereby destroying the superconducting state and causing serious damage. The turn-to-turn insulation 201 and the interlayer insulation 202 can effectively prevent this from happening.

[0034] The helium inlet and outlet 3 are located on the narrow surface of the conductor armor at the transition straight section from the second layer to the third layer and the transition straight section from the fourth layer to the fifth layer of the sub-coil winding. Due to the size limitation of the conductor armor, the shape of the helium inlet and outlet 3 is a runway shape.

[0035] The special-shaped transition bend outlet terminal 4 is located at the ends of the innermost and outermost layers of the coil winding, and is the conductor starting section and ending section of the armored conductor layer superconducting coil. The special-shaped transition bend is consistent with the radius of the conductor of the layer where it is located, and the outlet terminal is led vertically upward. A joint terminal 6 is welded at the terminal of the special-shaped transition bend outlet terminal 4.

[0036] The outlet head annular locking mechanism 5 is welded on the inner and outer sides of the narrow side of the armor of the special-shaped transition bend conductor and the narrow side of the armor of the previous turn conductor. The outlet head annular locking mechanism 5 is consistent with the radius of the conductor in the layer where it is located.

[0037] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, and it should be clear that the present invention is not limited to the scope of the specific embodiments, for those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. An end-stepped armored conductor layer superconducting coil structure, characterized in that: include: Coil winding (1), insulation (2), helium inlet and outlet (3), special-shaped transition bend outlet terminal (4), outlet terminal annular locking mechanism (5) and connector terminal (6); The coil winding (1) provides a magnetic field, and comprises an inner sub-coil winding (101) and an outer sub-coil winding (102); The insulation (2) includes inter-turn insulation (201) and inter-layer insulation (202), wherein the inter-turn insulation (201) is used for insulation between conductors between turns of the coil, and the inter-layer insulation (202) is used for adjusting the radial dimension of the coil during winding; The helium inlet and outlet (3) are used to circulate liquid helium so that the conductor maintains a low-temperature superconducting state; The special-shaped transition bent lead (4) is used to lead the conductor vertically upward from the coil winding (1); The outlet wire head annular locking mechanism (5) is used to fix the special-shaped transition bend outlet wire head (4); The connector terminal (6) is used to connect to a power source to energize the superconducting coil, and is used to connect the inner sub-coil winding (101) and the outer sub-coil winding (102); The inner sub-coil winding (101) and the outer sub-coil winding (102) each have six layers from the inside to the outside. The inter-layer segment between the layers is tangent to the large arc segment of the wound conductor through a straight line segment, and then tangent to the large arc segment of the next layer of conductor through a tangent small arc segment, thereby completing the inter-layer transition. The coil winding (1) forms a stepped end shape through different numbers of turns in each layer. The helium inlet and outlet (3) are arranged before the conductor layer transition straight section from the second layer to the third layer and from the fourth layer to the fifth layer of each sub-coil winding, ensuring that the liquid helium flow channels are of equal length. The helium inlet and outlet (3) are in the shape of a runway and are distributed on a single side of the coil winding (1) and on the conductor narrow surface of the interlayer straight section transition section.

2. The end-stepped armored conductor layer superconducting coil structure according to claim 1, characterized in that: The materials of the inter-turn insulation (201) and the inter-layer insulation (202) are both high temperature resistant carbon-removed glass fiber tapes; before the coil is wound, the inter-turn insulation (201) is spirally wrapped around the armored conductor in a three-layer semi-lapped manner, so that when the coil is energized, the adjacent conductors between turns are isolated, thereby avoiding short circuits between the conductors between turns of the coil; During the coil winding process, interlayer insulation (202) is laid between layers of the coil to adjust the radial dimension of the coil during the coil winding process.

3. The end-stepped armored conductor layer superconducting coil structure according to claim 2, characterized in that: The special-shaped transition bend wire ends (4) are all distributed on a single side of the coil winding (1).

4. The end-stepped armored conductor layer superconducting coil structure according to claim 3, characterized in that: The helium inlet and outlet (3) are both distributed on a single side of the coil winding (1), and are both on one side of the stepped end of the coil winding (1), while the other end of the coil winding (1) is flat.

5. The end-stepped armored conductor layer superconducting coil structure according to claim 4, characterized in that: The annular locking mechanism (5) of the outlet wire is welded to the special-shaped transition bend and the narrow surface of the conductor armor, and is used to fix the special-shaped transition bend outlet wire (4) to offset the conductor rebound force in the layered coil winding.

6. The end-stepped armored conductor layer superconducting coil structure according to claim 5, characterized in that: The weld seam of the annular locking mechanism (5) of the outlet is of segmented alternating type. The component of the annular locking mechanism (5) of the outlet welded on the inner side surface of the special-shaped transition bend is an inner connecting plate (501) for fixing the outlet (4) of the special-shaped transition bend. The component of the annular locking mechanism (5) of the outlet welded on the outer side surface of the special-shaped transition bend is an outer connecting plate (502). The component of the annular locking mechanism (5) of the outlet welded on the narrow surface of the armor of the previous conductor turn is a long strip connecting section (503). The radii of the inner connecting plate (501), the outer connecting plate (502) and the long strip connecting section (503) are consistent with the radii of the conductors in the layer where they are located. The long strip connecting section (503) is locked to offset the conductor rebound force in the coil winding (1).

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