Pluggable bendable current lead of superconducting magnet
By adopting the plug-in and unpluggable bending current lead design, the problems of temperature increase, thermal imbalance, stress concentration and maintenance difficulties in traditional magnet excitation current leads in 4K low-temperature environments are solved, achieving more effective heat dissipation and reducing electromagnetic interference and maintenance costs.
Patent Information
- Application Number
- CN202510364003.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-26
- Publication Date
- 2025-07-01
AI Technical Summary
Traditional magnet excitation current leads may cause local temperature to rise in 4K low-temperature environments, increasing the usage and cost of liquid helium; if the thermal design of the contact points between the lead and the superconducting coil is unreasonable, it may cause the risk of local thermal imbalance and failure; material shrinkage in low-temperature environments may lead to the concentration of stress between the lead and the surrounding structure, and long-term operation will cause the joint to loosen and crack; if the lead is built-in, it will not be able to undergo rapid repairs once a fault occurs, and the entire superconducting magnet needs to be dismantled, which will be huge; the manufacturing cost is high, and high-performance lead strips and precision thermal design are required.
The plug-in and unpluggable bending current lead design includes conductive plugs, lower conductive copper tubes, flexible braided copper wires, upper conductive copper tubes, bending joints and sleeves. The bending function is achieved through brazing and rivet connections, and maintenance costs are reduced through modular design.
It realizes more effective heat dissipation in 4K low-temperature environments, reducing liquid helium usage and cost; reducing electromagnetic interference and improving the normal operation stability of the equipment; the modular design makes maintenance costs low, and repairs can be done without dismantling magnets in the event of failure, reducing maintenance time and cost.
Smart Images
Figure CN120236847A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of current leads, and in particular to a pluggable and bendable current lead for a superconducting magnet. Background Art
[0002] Superconducting magnets are widely used in medical, high-energy physics, scientific research and other fields. They are indispensable equipment and play a vital role in social development. The interior of a superconducting magnet is an electromagnetic coil wound with superconducting wire and immersed in liquid helium, and the temperature of the coil is kept at 4.2K by a refrigerator to ensure that the magnet coil is in a superconducting state (i.e., 0 resistance). The magnet needs to reach a given magnetic field strength during work. To achieve this magnetic field, it is necessary to load current into the magnet coil for excitation so that the magnet reaches the magnetic field strength required for work. Therefore, the magnet excitation current lead is indispensable.
[0003] Most of the traditional magnet excitation current leads are integrated inside the magnet, which has many disadvantages: 1. The current leads will generate Joule heat when transmitting current, which may cause local temperature rise in a 4K low-temperature environment, increase the use of liquid helium, and thus increase costs; 2. If the thermal design of the contact point between the lead and the superconducting coil is unreasonable, it may cause the risk of local thermal imbalance, and then cause quenching; 3. Material shrinkage in a low-temperature environment may cause stress concentration between the lead and the surrounding structure, and long-term operation may cause the joints to loosen and crack; 4. After the lead is built in, once a fault occurs, it will not be able to be repaired quickly, and the entire superconducting magnet needs to be disassembled, resulting in huge losses; 5. The manufacturing cost is high, requiring high-performance lead strips and precise thermal design. Summary of the invention
[0004] In order to make up for the above shortcomings, the present invention provides a pluggable and bendable current lead for a superconducting magnet, which aims to improve the existing technology that may cause local temperature rise in a 4K low-temperature environment, increase the use of liquid helium, and thus increase the cost; if the thermal design of the contact point between the lead and the superconducting coil is unreasonable, it may cause the risk of local thermal imbalance and then cause quenching; material shrinkage in a low-temperature environment may cause stress concentration between the lead and the surrounding structure, and long-term operation will cause the joints to loosen and crack; after the lead is built-in, once a fault occurs, it will not be able to be quickly repaired, and the entire superconducting magnet needs to be disassembled, resulting in huge losses; the manufacturing cost is high, and high-performance lead strips and precise thermal design are required.
[0005] To achieve the above object, the present invention adopts the following technical solutions: A pluggable and bendable current lead for a superconducting magnet. The conductive plug includes a conductive plug, a lower conductive copper tube, a flexible braided copper wire, and an upper conductive copper tube, which are connected in sequence and fixed by brazing. The lower bending joint and the upper bending joint are connected by rivets and sleeved outside the flexible braided copper wire to achieve the bending of the device of the present invention. A spacer is placed inside the lower sleeve and fastened to the conductive plug, the lower conductive copper tube, and the lower bending joint by a number of screws. A spacer is placed inside the upper sleeve and fastened to the upper conductive copper tube and the upper bending joint by a number of fixing screws. The positioning sleeve is installed outside the upper sleeve. The excitation power supply connection block is installed at a specified position on the upper conductive copper tube and fastened by a locking screw. The exhaust interface is connected to the top of the upper conductive copper tube by internal and external threads.
[0006] As a further description of the above technical solution:
[0007] The conductive plug has a circular structure and has a corresponding number of tension release grooves along the axial direction to facilitate plugging and unplugging during operation. Its material is beryllium bronze, which has high strength and hardness, good electrical conductivity, corrosion resistance, non-magnetism, and cold resistance.
[0008] As a further description of the above technical solution:
[0009] The lower conductive copper tube and the upper conductive copper tube are both provided with ventilation holes on their tube walls. They are made of T2 pure copper, which has good electrical conductivity and corrosion resistance. The upper end of the upper conductive copper tube is machined with external threads for connecting the exhaust interface.
[0010] As a further description of the above technical solution:
[0011] The flexible braided copper wire is made of T2 pure copper and is used to connect the lower conductive copper tube and the upper conductive copper tube. Due to the flexibility of the braided wire, a bending structure can be achieved.
[0012] As a further description of the above technical solution:
[0013] The lower bending joint and the upper bending joint are made of SUS304 material and have through holes at their axial centers for the flexible braided copper wire to pass through. The lower bending joint and the upper bending joint are connected by rivets and achieve the bending function.
[0014] As a further description of the above technical solution:
[0015] The lower sleeve, the upper sleeve, and the spacer are all provided with a corresponding number of screw holes in the radial direction. They are made of GFRP material, which has high strength, light weight, and good insulation performance.
[0016] As a further description of the above technical solution:
[0017] The described excitation power supply connection block is installed at the designated position on the upper conductive copper pipe and fastened by locking screws. It is made of T2 pure copper to ensure excellent electrical conductivity.
[0018] As a further description of the above technical solution:
[0019] The material of the described exhaust interface is PTFE, which has good high and low temperature resistance and insulation performance. One end is a KF standard interface, and the other end is provided with an internal thread for connecting to the external thread at the upper end of the upper conductive copper pipe.
[0020] The present invention has the following beneficial effects:
[0021] In the present invention, the structure is simple and the manufacturing cost is low; the plug-and-play structure design is adopted, which is convenient for installation and disassembly and saves time; it is easier to dissipate heat, which can reduce the risk of overheating of the lead wires; the external placement can effectively reduce the electromagnetic interference generated by the current leads during the excitation of the magnet; the modular design, low maintenance cost, and no need to disassemble the magnet in case of failure, greatly reduce the maintenance cost and time. The bendable design can meet the requirements of the use space to a greater extent. The present invention has been verified by repeated experiments and fully meets the relevant technical indicators of the superconducting magnet excitation requirements, greatly improving the stability and success rate of the superconducting magnet excitation. Brief Description of the Drawings
[0022] Figure 1 It is a vertical bending state cross-sectional view of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention;
[0023] Figure 2 It is a straightening state cross-sectional view of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention;
[0024] Figure 3 It is a front view and a top view of the bending state of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention;
[0025] Figure 4 It is a front view and a top view of the straightening state of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention;
[0026] Figure 5 It is a schematic diagram of the use state of the bending state of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention;
[0027] Figure 6 It is a schematic diagram of the use state of the straightening state of a plug-and-play bendable current lead for a superconducting magnet proposed by the present invention.
[0028] Legend Explanation:
[0029] 1. Conductive plug; 2. Lower conductive copper tube; 3. Flexible braided copper wire; 4. Upper conductive copper tube; 5. Excitation power supply connection block; 6. Lower sleeve; 7. Upper sleeve; 8. Spacer sleeve; 9. Fixing screw; 10. Lower bending joint; 11. Upper bending joint; 12. Rivet; 13. Locking screw; 14. Exhaust interface; 15. Positioning sleeve. Specific embodiments
[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0031] Referring to Figure 1 and Figure 2 , an embodiment provided by the present invention: a pluggable and bendable current lead for a superconducting magnet, including a conductive plug 1, the conductive plug 1, the lower conductive copper tube 2, the flexible braided copper wire 3, and the upper conductive copper tube 4 are connected in sequence and fixed by brazing. The lower bending joint 10 and the upper bending joint 11 are connected by a rivet 12 and sleeved outside the flexible braided copper wire 3 to realize the bending of the device of the present invention. A spacer sleeve 8 and the conductive plug 1, the lower conductive copper tube 2, and the lower bending joint 10 are placed inside the lower sleeve 6 and fastened by a plurality of fixing screws 9. A spacer sleeve 8 and the upper conductive copper tube 4 and the upper bending joint 11 are placed inside the upper sleeve 7 and fastened by a plurality of fixing screws 9. The positioning sleeve 15 is installed outside the upper sleeve 7. The excitation power supply connection block 5 is installed at a specified position on the upper conductive copper tube 4 and fastened by a locking screw 13. The exhaust interface 14 is connected to the top of the upper conductive copper tube 4 by internal and external threads. The lower bending joint 10 and the upper bending joint 11 are made of SUS304 material, and a through hole is provided at the axial center for the flexible braided copper wire 3 to pass through. The lower bending joint 10 and the upper bending joint 11 are connected by a rivet 12 and realize the bending function;
[0032] Specifically, the conductive plug 1, the lower conductive copper tube 2, the flexible braided copper wire 3, and the upper conductive copper tube 4 are connected in sequence and then fixed by brazing. The lower bending joint 10 and the upper bending joint 11 are connected by a rivet 12 and sleeved outside the flexible braided copper wire 3, so that the device can be bent. A spacer 8 is placed inside the lower sleeve 6, and then it is fixed tightly to the conductive plug 1, the lower conductive copper tube 2, and the lower bending joint 10 with a fixing screw 9. A spacer 8 is also placed inside the upper sleeve 7, and then it is fixed tightly to the upper conductive copper tube 4 and the upper bending joint 11 with a fixing screw 9. The positioning sleeve 15 is sleeved outside the upper sleeve 7. The excitation power supply connection block 5 is installed at a specified position on the upper conductive copper tube 4 and fixed with a locking screw 13. The exhaust interface 14 and the top end of the upper conductive copper tube 4 are connected by internal and external threads. Both the lower bending joint 10 and the upper bending joint 11 are made of SUS304 material and have through holes in the middle to allow the flexible braided copper wire 3 to pass through. The lower bending joint 10 and the upper bending joint 11 are connected by a rivet 12 to achieve the bending function.
[0033] Refer to Figure 2 , Figure 4 and Figure 5 , the conductive plug 1 has a circular structure and has a corresponding number of tension release grooves along the axial direction to facilitate plugging and unplugging during operation. Its material is beryllium bronze, which has high strength and hardness, good electrical conductivity, corrosion resistance, non-magnetism, and cold resistance. The lower conductive copper tube 2 and the upper conductive copper tube 4 have ventilation holes on their tube walls and are made of T2 pure copper, which has good electrical conductivity and corrosion resistance. The upper end of the upper conductive copper tube 4 is machined with external threads to connect to the exhaust interface 14. The flexible braided copper wire 3 is made of T2 pure copper and is used to connect the lower conductive copper tube 2 and the upper conductive copper tube 4. Due to the flexibility of the braided wire, a bending structure can be achieved;
[0034] Specifically, this conductive plug 1 is circular and has some grooves in the middle to facilitate plugging and unplugging. It is made of beryllium bronze, which is high in strength, hard, good in conductivity, corrosion-resistant, non-magnetic, and cold-resistant. Both the lower and upper conductive copper tubes 2 and 4 have ventilation holes and are made of T2 pure copper, which is good in conductivity and corrosion-resistant. The upper conductive copper tube 4 has threads on it to connect to the exhaust interface 14. The flexible braided copper wire 3 is also made of T2 pure copper and connects the lower and upper conductive copper tubes 2 and 4. Because it is flexible, it can be bent.
[0035] Refer to Figure 3 and Figure 6, the lower casing 6, upper casing 7, and spacer 8 are each provided with a corresponding number of screw holes. They are made of GFRP material, which has high strength, light weight, and good insulation performance. The excitation power supply connection block 5 is installed at a specified position on the upper conductive copper tube 4 and fastened by locking screws 13. It is made of T2 pure copper to ensure excellent electrical conductivity. The exhaust interface 14 is made of PTFE, which has good high and low temperature resistance and insulation performance. One end is a KF standard interface, and the other end is provided with an internal thread for connecting to the external thread at the upper end of the upper conductive copper tube 4;
[0036] Specifically, this device has a lower casing 6, an upper casing 7, and a spacer 8, all of which have screw holes. These parts are made of GFRP material, which is high-strength, lightweight, and has good insulation. There is also an excitation power supply connection block 5, which is installed at a specific position on the upper conductive copper tube 4 and fixed with locking screws 13. This connection block is made of T2 pure copper and has excellent electrical conductivity. The material of the exhaust interface 14 is PTFE, which is resistant to high and low temperatures and has good insulation performance. One end of this interface is a KF standard interface, and the other end has an internal thread that can be connected to the external thread at the upper end of the upper conductive copper tube 4.
[0037] Working principle: This design features structural simplicity, which significantly reduces the manufacturing cost. By adopting a plug-and-play structural design, the installation and disassembly process of the entire device becomes extremely convenient. In addition, this design also has good heat dissipation performance, which can effectively reduce the potential risks caused by overheating of the leads. In terms of electromagnetic interference, through an externalized method, this design can effectively reduce the electromagnetic interference generated by the current leads during magnet excitation, thus ensuring the normal operation of the device. At the same time, the modular design greatly reduces the maintenance cost. When the device fails, it can be repaired without disassembling the magnet, which not only reduces the maintenance cost but also saves the time required for maintenance. This design also has the feature of being bendable, which can better meet the user's requirements for the use space. After repeated experimental verification, the present invention fully meets the relevant technical indicators required for superconducting magnet excitation, thus greatly improving the stability and success rate of superconducting magnet excitation.
[0038] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A superconducting magnet pluggable bendable current lead, comprising a conductive plug (1), characterized in that: The conductive plug (1), the lower conductive copper tube (2), the flexible braided copper wire (3), and the upper conductive copper tube (4) are connected in sequence and fixed by brazing. The lower bending joint (10) and the upper bending joint (11) are connected by rivets (12) and then sleeved on the outside of the flexible braided copper wire (3) to achieve bending of the device of the present invention. A spacer (8) is placed inside the lower sleeve (6) and is fastened with the conductive plug (1), the lower conductive copper tube (2), and the lower bending joint (10) by a plurality of fixing screws (9). A spacer (8) is placed inside the upper sleeve (7) and is fastened with the upper conductive copper tube (4) and the upper bending joint (11) by a plurality of fixing screws (9). A positioning sleeve (15) is installed outside the upper sleeve (7). An excitation power supply terminal block (5) is installed at a designated position of the upper conductive copper tube (4) and is fastened by a locking screw (13). An exhaust interface (14) is connected with the top of the upper conductive copper tube (4) by internal and external threads.
2. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The conductive plug (1) is a circular structure with a corresponding number of tension release grooves left along the axial direction to facilitate plugging and unplugging during operation. It is made of beryllium bronze, which has high strength and hardness, good conductivity, corrosion resistance, non-magneticity and cold resistance.
3. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The lower conductive copper tube (2) and the upper conductive copper tube (4) are both provided with ventilation holes on their walls and are made of T2 pure copper, which has good conductivity and corrosion resistance. The upper end of the upper conductive copper tube (4) is processed with an external thread for connecting to the exhaust interface (14).
4. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The flexible braided copper wire (3) is made of T2 pure copper and is used to connect the lower conductive copper tube (2) and the upper conductive copper tube (4). Due to the softness of the braided wire, a bending structure can be achieved.
5. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The lower bending joint (10) and the upper bending joint (11) are made of SUS304 material, and a through hole is provided in the axial center for the flexible braided copper wire (3) to pass through. The lower bending joint (10) and the upper bending joint (11) are connected by rivets (12) to achieve a bending function.
6. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The lower sleeve (6), the upper sleeve (7) and the spacer (8) are all provided with a corresponding number of screw holes in the radial direction and are made of GFRP material, which has high strength, light weight and good insulation performance.
7. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The excitation power supply terminal block (5) is installed at a designated position of the upper conductive copper tube (4) and is fastened by a locking screw (13). It is made of T2 pure copper to ensure excellent conductive performance.
8. The superconducting magnet pluggable bendable current lead according to claim 1, characterized in that: The exhaust interface (14) is made of PTFE, which has good high and low temperature resistance and insulation performance. One end is a KF standard interface, and the other end is provided with an internal thread for connecting to the external thread on the upper end of the upper conductive copper tube (4).