High-temperature superconducting current lead structure based on helium cooling and feeding through the coil box

Abstract

The present invention discloses a high-temperature superconducting current lead structure based on helium refrigeration and feeding through a coil box body, comprising a current lead, wherein superconducting slots are provided on both the front and rear sides of the current lead, a helium tube clamping slot is provided at one end of the top of the current lead, and a helium tube is clamped in the helium tube clamping slot. The present invention is applicable to the technical field of superconducting magnets. The superconducting slots of the current lead are fed through the coil box, and after the superconducting tape and the copper rod are brazed, the sealing performance requirements of the coil box body can be met; after the sealing copper tube and the current lead are brazed with indium tin solder, a sealing effect is achieved; the sealing copper tube and the sealing stainless steel tube are brazed with silver-based solder to achieve sealing; the sealing steel tube and the Dewar connecting flange are connected by an insulator, which not only achieves a sealing effect but also insulates the box body and the current lead; through the multi-pass sealing structure, the insulated feedthrough of the current lead is achieved, thereby achieving sealed current flow for the high-temperature superconducting magnet.

Description

Technical Field

[0001] The invention belongs to the technical field of superconducting magnets, and in particular is a high-temperature superconducting current lead structure based on helium refrigeration and feeding through a coil box. Background Art

[0002] Superconducting magnets are an important component of the high-temperature superconducting tokamak device. In order to obtain a higher magnetic field, it is necessary to design a higher current magnet to maintain the normal operation of the tokamak device. At the same time, it also places higher requirements on the current leads to achieve higher current flow without causing additional heat loss. In addition, the coils are often sealed in a box, and current transmission feedthrough is necessary, and the current feedthrough also needs to be insulated from the dewar. At present, there are no current leads on the market that can meet the design requirements. Therefore, it is urgent to design a current lead that can achieve high current flow based on helium refrigeration, realize insulated current lead feedthrough, and then realize sealed current flow for the high-temperature superconducting magnet. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a high-temperature superconducting current lead structure based on helium refrigeration and feeding through a coil box.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A high-temperature superconducting current lead structure based on helium refrigeration and feeding through a coil box body comprises a current lead, wherein superconducting slots are provided on both the front and rear sides of the current lead, and a helium tube clamping slot is provided at one end of the top of the current lead, in which a helium tube is clamped.

[0006] Preferably, the superconducting slot adopts a square slot structure.

[0007] Preferably, the helium tube slot adopts a U-shaped slot structure, and the helium tube is fixed in the helium tube slot by indium tin brazing.

[0008] Preferably, the helium tube is arranged in the coil box body, the current lead is located outside the coil box body and is sheathed with a sealed copper tube, the outer side of the sealed copper tube is sheathed with a Dewar connecting flange, and the side of the Dewar connecting flange close to the coil box body is successively sheathed with an insulator and a sealed steel tube.

[0009] Preferably, several superconducting tapes are embedded in the superconducting slots, and the several superconducting tapes are arranged vertically. The outer sides of the superconducting tapes are limited by copper tapes. The superconducting tapes, current leads and sealing copper tubes are impregnated with vacuum solder to form an integrated structure.

[0010] Preferably, the sealing copper tube and the sealing steel tube are brazed and sealed by silver-based solder, and the Dewar link flange and the sealing steel tube are connected by an insulator.

[0011] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0012] In the present invention, the current lead superconducting slot is fed into the coil box, and after the superconducting tape and the copper rod are brazed, the sealing performance requirements of the coil box body can be met; after the sealing copper tube and the current lead are brazed with indium tin solder, a sealing effect is achieved; the sealing copper tube and the sealing steel tube are brazed with silver-based solder to achieve sealing, and the sealing steel tube and the Dewar connecting flange are connected by an insulator, which not only achieves the sealing effect but also can insulate the box body and the current lead; through the multi-channel sealing structure, the current lead is insulated and fed through, thereby achieving sealed flow for the high-temperature superconducting magnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Is a schematic diagram of the overall structure of the present invention;

[0014] Figure 2 It is a cross-sectional view of the current lead in the present invention.

[0015] Reference numerals: 1. current lead; 11. superconducting slot; 12. helium tube slot; 13. helium tube; 2. Dewar connecting flange; 3. insulator; 4. sealing steel tube; 5. sealing copper tube. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are described in detail below.

[0017] The "ranges" disclosed herein are defined in the form of lower and upper limits. A given range is defined by selecting a lower limit and an upper limit, and the selected lower and upper limits define the boundaries of the particular range. Ranges defined in this manner can be inclusive or exclusive and can be combined arbitrarily, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range of 10 to 50 is listed for a particular parameter, it is understood that ranges of 10 to 40 and 20 to 50 are also contemplated. Furthermore, if the minimum range values ​​listed are 1 and 2, and if the maximum range values ​​listed are 3, 4, and 5, then the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" is an abbreviation for any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 to 5" are listed herein, and "0 to 5" is simply an abbreviation for these numerical combinations.

[0018] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0019] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0020] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or may include steps (b) and (a) performed sequentially. For example, the method may further include step (c), indicating that step (c) may be added to the method in any order, for example, the method may include steps (a), (b) and (c), or may include steps (a), (c) and (b), or may include steps (c), (a) and (b), etc.

[0021] Unless otherwise specified, the terms "include" and "comprising" used in this application may be open-ended or closed-ended. For example, "include" and "comprising" may mean that other components not listed may also be included or that only the listed components are included.

[0022] Unless otherwise specified, the reaction is carried out at room temperature and pressure.

[0023] Unless otherwise specified, all parts or percentages are by weight.

[0024] In the present invention, all substances used are known substances and can be purchased or synthesized by known methods.

[0025] In the present invention, the devices or equipment used are all conventional devices or equipment known in the art and are commercially available.

[0026] The following examples further illustrate the specific implementation of the HTS current lead structure based on helium refrigeration and feeding through the coil box of the present invention. The HTS current lead structure based on helium refrigeration and feeding through the coil box of the present invention is not limited to the description of the following examples.

[0027] Example 1:

[0028] Based on the high-temperature superconducting current lead structure of helium cooling and feeding through the coil box, such as Figure 1-2 As shown, it includes a current lead 1, with superconducting grooves 11 on both the front and rear sides of the current lead 1, a helium tube clamping groove 12 on one end of the top of the current lead 1, and a helium tube 13 clamped in the helium tube clamping groove 12.

[0029] In a possible implementation, the superconducting slot 11 adopts a square slot structure with a width of 4.5 mm and a depth of 7 mm.

[0030] In a possible implementation, the helium tube slot 12 adopts a U-shaped slot structure, the helium tube 13 is a copper tube with a diameter of 1 mm and a length of 6 mm, and the helium tube 13 is fixed in the helium tube slot 12 by indium tin brazing.

[0031] In one possible embodiment, the helium tube 13 is arranged in the coil box body, the current lead 1 is located outside the coil box body and is sleeved with a sealed copper tube 5, the outside of the sealed copper tube 5 is sleeved with a Dewar connecting flange 2, and the side of the Dewar connecting flange 2 close to the coil box body is sleeved with an insulator 3 and a sealed steel tube 4 in sequence.

[0032] In one possible embodiment, 120 superconducting tapes are embedded in the superconducting groove 11, and the 120 superconducting tapes are arranged vertically. The outside of the superconducting tape is limited by a copper tape with a thickness of 0.1 mm. The superconducting tape, the current lead 1 and the sealing copper tube 5 are impregnated with vacuum solder to form an integrated structure.

[0033] In a possible implementation, the sealing copper tube 5 and the sealing steel tube 4 are brazed and sealed by silver-based solder, and the Dewar connecting flange 2 and the sealing steel tube 4 are connected by an insulator 3 .

[0034] In one possible implementation, Figure 2 As shown, the current lead 1 is made of a solid copper rod with a diameter of 20 mm (material TU1), and its cross section is processed with three grooves: two square grooves with a width of 4.5 mm and a depth of 7 mm, and a U-shaped groove embedded in the cold helium tube; the area is divided as follows Figure 2 As shown in the figure, the helium tube 13 is a 6*1mm diameter copper tube, brazed with indium tin within the current lead slot. The two square slots in the current lead 1 contain 120 strands of superconducting tape (the tapes are arranged vertically, with 0.1mm thick copper tape used to limit the outermost slots). The tape, copper rod, and copper tube are impregnated into a single structure using a vacuum solder impregnation method. Current lead 1 can achieve a current greater than 100kA at 10K under a 2T background magnetic field, with an operating resistance of less than 3nΩ.

[0035] In a possible embodiment, the current lead feedthrough structure is detailed in the attached Figure 1The structure includes a current lead 1, a helium tube 13, a sealing copper tube 5, a sealing steel tube 4, an insulator 3, and a Dewar connecting flange 2. The left side is the inner side of the coil box, and the right side is the outer side of the coil box. The helium tube 13 is made of TU1 and is embedded in the helium tube slot 12. The helium tube slot 12 is a U-shaped structure, and it is cut off at the front end of the feed-through Dewar connecting flange 2, with a distance of 20mm. The current lead 1 superconducting slot 11 is fed into the coil box. After the superconducting tape and the copper rod are brazed, the sealing performance requirements of the coil box can be met. The sealing copper tube 5 and the current lead 1 are brazed with indium tin solder to play a sealing role. The sealing copper tube 5 and the sealing steel tube 4 are brazed with silver-based solder to achieve sealing. The sealing steel tube 4 and the Dewar connecting flange 2 are connected by the insulator 3, which not only achieves the sealing effect, but also insulates the box body from the current lead 1. The above multiple seals can meet the leakage rate of less than 10 -9 Pa.m 3 / s.

[0036] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box, characterized by: The invention comprises a current lead (1), wherein superconducting grooves (11) are provided on both the front and rear sides of the current lead (1), a helium tube clamping groove (12) is provided on one end of the top of the current lead (1), and a helium tube (13) is clamped in the helium tube clamping groove (12).

2. The high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box according to claim 1, characterized in that: The superconducting slot (11) adopts a square slot structure.

3. The high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box according to claim 1, characterized in that: The helium tube slot (12) adopts a U-shaped slot structure, and the helium tube (13) is fixed in the helium tube slot (12) by indium tin brazing.

4. The high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box according to claim 1, characterized in that: The helium tube (13) is arranged in the coil box body, the current lead (1) is located outside the coil box body and is sheathed with a sealed copper tube (5), the outer side of the sealed copper tube (5) is sheathed with a Dewar connecting flange (2), and the side of the Dewar connecting flange (2) close to the coil box body is sheathed with an insulator (3) and a sealed steel tube (4) in sequence.

5. The high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box according to claim 4, characterized in that: A plurality of superconducting tapes are embedded in the superconducting slot (11), and the plurality of superconducting tapes are arranged vertically. The outer sides of the superconducting tapes are limited by copper tapes. The superconducting tapes, the current lead (1) and the sealing copper tube (5) are impregnated with vacuum solder to form an integrated structure.

6. The high-temperature superconducting current lead structure based on helium refrigeration and feeding through the coil box according to claim 4, characterized in that: The sealing copper tube (5) and the sealing steel tube (4) are brazed and sealed by silver-based solder, and the Dewar connecting flange (2) and the sealing steel tube (4) are connected by an insulator (3).

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