A superconducting beam line and fabrication process

Abstract

The application provides a high-heat-dissipation, high-flexibility and high-isotropy superconducting bundled wire which is composed of a buckle center framework, superconducting tapes and an external protective sleeve. The buckle center framework is used in the technical scheme, the unit buckle rings in the buckle center framework are buckled to each other through buckling and have a movable allowance between each other, so that the buckle center framework can be bent without plastic deformation of the metal framework, strain accumulation of the superconducting tapes caused by bending is avoided, and the limit bending radius is small. The gap on the wall of the buckle center framework can accelerate the cooling efficiency of the bundled wire during pre-cooling of the cooling medium, and allows the cooling medium to flow in the radial and axial directions during formal operation of the bundled wire, so that the heat exchange efficiency of the superconducting tapes is increased.

Description

Technical Field

[0001] This invention belongs to the field of superconducting wire bundle technology, specifically relating to a superconducting bundled wire with high heat dissipation, high flexibility, and high isotropy. Background Technology

[0002] Superconducting conductors offer advantages over conventional conductors, including higher current density, lower heat generation, and lower AC losses, making them highly promising for energy storage in superconducting coil magnets. Due to the limited current-carrying capacity of a single superconducting tape, multiple tapes need to be connected in parallel. Because of the different parallel connection methods for superconducting tapes, many superconducting bundled wires with different structures have emerged in recent years. Examples include the Roebel bundled wire and the TSTC bundled wire. Roebel uses superconducting tapes cut into trapezoidal shapes, which are then stacked and connected in parallel after being transposed; the TSTC bundled wire uses superconducting tapes directly stacked in parallel and then twisted together.

[0003] The current drawbacks of several superconducting bundled wire configurations include insufficient limiting bending radius, which prevents adequate bending margin during the winding of superconducting coil magnets, leading to a decline in critical current. Furthermore, the pre-cooling efficiency of these configurations is relatively low, resulting in prolonged pre-cooling times. Therefore, their pre-cooling efficiency needs further improvement. During actual operation, the cooling medium in these configurations can only flow axially, resulting in low heat transfer efficiency of the superconducting tape. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by proposing a novel superconducting bundled wire with a small ultimate bending radius, high pre-cooling efficiency, and the ability for the cooling medium to flow simultaneously in the axial and radial directions during operation, resulting in high heat exchange efficiency for the superconducting tape.

[0005] Includes a snap-fit ​​central frame, superconducting tape, and external protective sleeve;

[0006] The snap-fit ​​central skeleton is composed of several snap-fit ​​rings connected together, which is used to support the winding of superconducting tape;

[0007] The unit buckle ring of the buckle center frame has an S-shaped cross-section. Depending on the distance from the central axis of the bundle line, the S-shaped structure is divided into a short side and a high side, which are connected by a connecting ramp.

[0008] The superconducting tape is used for current carrying;

[0009] The superconducting tape has two adjacent layers wound in opposite directions, and the bundled lines have an axisymmetric structure.

[0010] The external protective sleeve is used to protect the superconducting tape and serves as a channel for liquid nitrogen flow.

[0011] Based on the above scheme, the connecting ramp angle is the axial angle between the ramp and the unit buckle ring, and the ramp angle is between 30 and 90 degrees.

[0012] Based on the above scheme, the lower and higher sides of two adjacent unit buckle rings cooperate with each other: the higher side is locked on the outside of the lower side, and several unit buckle rings are connected together to form a buckle center skeleton with a certain length.

[0013] Based on the above scheme, the connection method between adjacent unit buckle rings is a deformable connection.

[0014] Based on the above scheme, the buckle center frame is a hollow tube structure, and the diameter of the hollow tube is adjustable.

[0015] Based on the above scheme, a fabrication process for superconducting bundled wires is provided, including the following steps:

[0016] Create the central frame of the snap fastener;

[0017] Superconducting tape is wound around the central skeleton of the buckle;

[0018] Put an outer protective cover on the outermost layer;

[0019] Pre-cooling is achieved by introducing cold nitrogen gas into the central tube of the snap-fit.

[0020] After pre-cooling, liquid nitrogen is introduced to complete the overall cooling of the superconducting coil magnet.

[0021] The beneficial effects of this invention are:

[0022] The superconducting bundled wire skeleton of this invention is a snap-fit ​​central skeleton. The snap-fit ​​rings within this central skeleton are not rigidly connected but rather interlocked, allowing for some flexibility. Therefore, bending can be achieved without plastic deformation of the metal skeleton, preventing strain accumulation that could impair the current-carrying capacity of the superconducting tape during bending, resulting in a small ultimate bending radius. The gaps in the snap-fit ​​central skeleton walls allow the cooling medium to accelerate the pre-cooling efficiency of the bundled wire during pre-cooling and permit simultaneous radial and axial flow of the cooling medium during normal operation, increasing the heat transfer efficiency of the superconducting tape. Attached Figure Description

[0023] The present invention includes the following figures:

[0024] Figure 1 This is a schematic diagram of a superconducting bundled wire with high heat dissipation, high flexibility, and high isotropy;

[0025] Figure 2 A schematic diagram of the unit snap rings that make up the central frame of the snap fastener;

[0026] Figure 3 A side view of the unit buckle ring that makes up the central frame of the buckle;

[0027] Figure 4 A schematic cross-sectional view of the unit snap ring that makes up the central skeleton of the snap fastener;

[0028] Figure 5 This is a schematic diagram of the overall frame of the buckle center;

[0029] Figure 6 This is a cross-sectional schematic diagram of the central frame of the snap fastener;

[0030] Figure 7 This is a schematic diagram of the bent state of the central frame of the buckle;

[0031] Figure 8 A schematic diagram of the superconducting bundled wire after the superconducting tape is wound on the central skeleton of the snap fastener.

[0032] In the diagram: 1. Snap-on central skeleton, 2. Superconducting tape, 3. External protective sleeve, 4. Low side, 5. High side, 6. Connecting ramp, 7. Distance. Detailed Implementation

[0033] To make the objectives, advantages, and features of the present invention more apparent, the following description is provided in conjunction with the appendix. Figure 1-8 The present invention will be further described in detail below with reference to specific embodiments.

[0034] like Figure 1 As shown, the superconducting bundled wire with high heat dissipation, high flexibility, and high isotropy consists of a snap-fit ​​central skeleton 1, a superconducting strip 2, and an outer protective sleeve 3.

[0035] The snap-fit ​​central skeleton 1 is composed of several unit snap-fit ​​rings connected together. It is made of metal materials, such as stainless steel, aluminum, and copper, and serves to support the superconducting tape radially along the bundle line. Its shape includes, but is not limited to, circles, squares, and ellipses. It primarily supports the winding of the superconducting tape and has excellent bending performance: due to its special snap-fit ​​structure, it can be bent with only a small force.

[0036] The superconducting tape 2 serves as a current-carrying material and is the current channel for the superconducting bundled wire. The two adjacent layers of the superconducting tape are wound in opposite directions, and the bundled wire has an axisymmetric structure. Therefore, a superconducting bundled wire with high heat dissipation, high flexibility, and high isotropy has excellent anisotropy.

[0037] The inner diameter of the outer protective sleeve 3 is slightly larger than the outer diameter of the bundled wire after the superconducting tape is wound. Its main function is to protect the superconducting tape, and it also serves as a liquid nitrogen flow channel, allowing the superconducting tape to be completely immersed in liquid nitrogen. Its outer shape includes, but is not limited to, circular, square, and elliptical shapes.

[0038] like Figure 2 , 3 As shown in Figure 4, the unit snap ring that makes up the central frame of the snap fastener has an S-shaped cross-section. Depending on the distance from the central axis of the bundle line, the S-shaped structure can be divided into a lower side 4 and a higher side 5, which are connected by a connecting ramp 6. The ramp angle of the connecting ramp 6 can be adjusted according to requirements.

[0039] The slope angle is the angle between the slope and the axial direction of the unit snap ring, and the slope angle is generally between 30 and 90 degrees. By adjusting the slope angle, the axial distance 7 between the lower side 4 and the higher side 5 of the unit snap ring can be adjusted.

[0040] like Figure 5 , 6 As shown, the lower side 4 and the higher side 5 of two adjacent unit buckle rings cooperate with each other: the higher side 5 is locked on the outside of the lower side 4, and several unit buckle rings are connected together to form a buckle central skeleton with a certain length.

[0041] The unit snap rings are not rigidly connected to each other, and there is a relative margin of movement between them. Therefore, bending them does not require plastic deformation of the metal; only a small external force is needed. Also, because there is no rigid connection between adjacent unit snap rings, gaseous or liquid media can flow bidirectionally through the gaps between the unit snap rings, both inside and outside the snap ring central frame.

[0042] The central frame of the buckle is a hollow tube structure, and the diameter of the hollow tube can be adjusted according to requirements, generally greater than or equal to 2mm. The wall thickness of the hollow tube can also be controlled by adjusting the size of the "S" in the unit buckle ring, and the wall thickness of the hollow tube is generally greater than or equal to 0.5mm.

[0043] like Figure 7 As shown, after bending the central frame of the snap-fit ​​mechanism, the distance 7 on the inner side of the bend decreases, while the distance 7 on the outer side of the bend increases. Before the distance 7 on the inner side of the bend decreases to 0, there is still a relative margin of movement between the unit snap-fit ​​rings, and only a small force is needed to bend the central frame of the snap-fit ​​mechanism. Therefore, we can determine the ramp angle based on the bending radius required by the superconducting magnet coil, thereby obtaining a suitable distance 7.

[0044] like Figure 8 As shown, the superconducting tape is spirally and tightly wound onto the central frame of the clip, with the winding angle generally between 20 and 70 degrees; the number of superconducting tape strands wound in each layer is greater than or equal to one; the winding direction of the superconducting tape between adjacent layers is opposite.

[0045] The following section will introduce the overall fabrication process of a high-heat-dissipation, high-flexibility, and high-isotropy superconducting bundled wire:

[0046] First, a snap-fit ​​central skeleton 1 is fabricated using methods such as 3D printing. Then, superconducting tape is wound around the snap-fit ​​central skeleton 1. The number of superconducting tapes is determined by the current carrying capacity of the bundled wire. The winding angle and the gap between the superconducting tapes are calculated by inversely deducing the bending radius of the superconducting coil magnet. Finally, an outer protective sleeve is applied to the outermost layer by pulling. Next, a pre-fabricated superconducting bundled wire with high heat dissipation, high flexibility, and high isotropy is used to wind the superconducting coil magnet. After winding, the superconducting bundled wire is cooled. Directly introducing liquid nitrogen for cooling would cause stress concentration due to thermal expansion and contraction, damaging the superconducting tape. Therefore, the superconducting bundled wire is pre-cooled by introducing cold nitrogen gas into the snap-fit ​​central tube. Because there are gaps in the wall of the snap-fit ​​central tube, the cold nitrogen gas can flow out through these gaps to pre-cool the superconducting tape, increasing cooling efficiency without causing thermal stress damage to the superconducting tape. The non-rigid connection structure between the snap-fit ​​rings in the snap-fit ​​central skeleton of this invention makes the snap-fit ​​central skeleton more flexible. This not only gives the superconducting bundled wire good bending performance, but the gaps in its walls also accelerate the cooling efficiency of the superconducting bundled wire. After pre-cooling, liquid nitrogen is introduced to complete the overall cooling of the superconducting coil magnet. The gaps in the snap-fit ​​central tube wall allow liquid nitrogen to flow radially along the bundled wire, compared to the conventional bundled wire which only flows axially. This increases the heat transfer efficiency of the superconducting tape, allowing heat to be carried away in time when the superconducting cable coil magnet heats up locally, and also reduces the risk of quench propagation.

[0047] The above embodiments are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art can make various changes and modifications without departing from the essence and scope of this invention. Therefore, all equivalent technical solutions also fall within the scope of this invention, and the patent protection scope of this invention should be defined by the claims. Content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A superconducting bundled wire, characterized in that, It includes a snap-fit ​​central skeleton (1), a superconducting tape (2), and an external protective sleeve (3); The snap-fit ​​center frame (1) is composed of several snap-fit ​​rings connected together, and is used to support the winding of superconducting strips; The unit buckle ring of the buckle center skeleton (1) has an S-shaped cross-section. According to the distance from the central axis of the bundle line, the S-shaped structure is divided into a short side (4) and a high side (5). The short side (4) and the high side (5) are connected by a connecting ramp (6). The superconducting tape (2) is used for current carrying; the two adjacent layers of the superconducting tape are wound in opposite directions, and the bundled lines have an axisymmetric structure; The external protective sleeve (3) is used to protect the superconducting tape and serves as a liquid nitrogen flow channel; The lower side (4) and the higher side (5) of two adjacent unit buckle rings cooperate with each other: the higher side (5) is locked on the outside of the lower side (4), and several unit buckle rings are connected together to form a buckle center skeleton with a certain length. The connection between adjacent unit buckle rings is a deformable connection; The buckle center frame (1) is a hollow tube structure, and the diameter of the hollow tube is adjustable; There are gaps between the unit buckle rings.

2. The superconducting bundled wire according to claim 1, characterized in that, The angle of the connecting ramp (6) is the axial angle between the ramp and the unit buckle ring, and the ramp angle is between 30 and 90 degrees.

3. A fabrication process for a superconducting bundled wire, used to fabricate the superconducting bundled wire as described in any one of claims 1-2, characterized in that, Includes the following steps: Create the central frame of the snap fastener; Superconducting tape is wound around the central skeleton of the buckle; Put an outer protective cover on the outermost layer; Pre-cooling is achieved by introducing cold nitrogen gas into the central tube of the snap-fit. After pre-cooling, liquid nitrogen is introduced to complete the overall cooling of the superconducting coil magnet.

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