Superconducting switch with sealing cylinder
By introducing a sealed cylinder and a high-pressure helium condensate immersion design into the superconducting switch, combined with an inductive coil and a thermally conductive connecting column, the contradiction between cooling and heat insulation of the superconducting switch in the conductive cooling superconducting magnet system is resolved, achieving efficient cooling and stable operation.
Patent Information
- Application Number
- CN202511656405.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-12
- Publication Date
- 2026-02-13
AI Technical Summary
In conductive cooling superconducting magnet systems, superconducting switches are easily affected by external disturbances, causing them to transition from the superconducting state to the normal state. Furthermore, there are contradictions in the thermal connection design, making it difficult to simultaneously ensure good cooling and thermal insulation requirements.
Design a superconducting switch with a sealed cylinder filled with high-pressure helium. The superconducting switch is located at the bottom of the sealed cylinder. The superconducting switch is immersed in liquid helium by condensing the high-pressure helium. Combined with the design of a non-inductive coil and a heat-conducting connecting column, it can achieve all-round cooling and heat dissipation.
This technology achieves efficient cooling and thermal disturbance suppression of superconducting switches, maintains the stability of the superconducting state, simplifies the power supply structure, and enhances anti-interference capabilities by adjusting thermal conductivity to control heat transfer.
Smart Images
Figure CN121531932A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of superconducting technology, and particularly relates to a superconducting switch with a sealing cylinder. BACKGROUND
[0002] In the late 1990s, due to the breakthrough of small refrigeration machine technology and the emergence of high-temperature superconducting current leads, the conduction-cooled superconducting magnet technology has developed rapidly and gradually has the potential to replace the liquid helium immersed superconducting magnet. Unlike the traditional liquid helium immersed superconducting magnet system, the conduction-cooled superconducting magnet does not use liquid helium for cooling, but uses a refrigerator as a cold source to cool the superconducting magnet through solid connection. At present, the conduction-cooled superconducting magnet is mainly used to provide a stable magnetic field of tens of thousands of gauss to hundreds of thousands of gauss. After the conduction-cooled superconducting magnet is fully charged, it generally needs to be operated in a persistent current mode by forming a closed loop circuit with a superconducting switch and a superconducting coil, so that the superconducting magnet can obtain a very high stability of the magnetic field, and the influence of external noise on the superconducting magnet system can be reduced, and the reliability of the magnet operation can be improved. It can be seen that in the application of the conduction-cooled superconducting magnet, the superconducting switch is an important component.
[0003] The superconducting switch generally uses the transition of the superconducting state-normal state of the superconducting material to make the superconducting switch change from a non-resistance state to a resistance state, so as to achieve the purpose of making the circuit change from being conductive to being disconnected; and correspondingly, the transition of the normal state-superconducting state of the superconducting material is used to realize the conduction of the circuit. The transition of the superconducting state-normal state and the normal state-superconducting state of the superconducting switch is generally achieved by changing the temperature or background magnetic field of the superconducting material to realize the transition between the superconducting state and the normal state, and the two kinds of superconducting switches are respectively called temperature-controlled superconducting switches and magnetic-controlled superconducting switches. Among them, the temperature-controlled superconducting switch has a relatively simple structure and is most widely used in practical applications.
[0004] In the conduction-cooled superconducting magnet system, the superconducting magnet and the superconducting switch are both cooled by the refrigerator, and the refrigeration power of the refrigerator is limited. For example, the refrigeration power of the SHI-SRDK415D type refrigerator is 35W at 50K for the primary cold head, and only 1.5W at 4.2K for the secondary cold head. Therefore, there are contradictory factors in the thermal connection between the superconducting switch and the superconducting magnet: on the one hand, good thermal connection is needed to ensure that the superconducting switch can be fully cooled to achieve the superconducting state; but on the other hand, when the heating wire heats the superconducting switch to make it work in the normal state, it is hoped that there is thermal insulation between the superconducting switch and the superconducting magnet to ensure that the conduction heat from the superconducting switch to the superconducting magnet is as small as possible, so as not to cause the superconducting magnet to overheat and lose superconductivity. Therefore, the heat conduction connection between the superconducting switch and the superconducting magnet will be limited, which will lead to the fact that the cooling effect of each part of the superconducting coil on the superconducting switch is not completely the same. When external disturbances cause local heat to be generated in the superconducting switch and difficult to be quickly taken away through conduction cooling, the heat accumulation will make the superconducting switch in the superconducting state change to the normal state. SUMMARY
[0005] In order to overcome the defect that the existing conduction-cooled superconducting switch is easily converted from superconducting state to normal state by external disturbance, the application provides a superconducting switch with a sealed cylinder. When the heating wire is not heated, the superconducting switch is in superconducting state, and the high-pressure helium gas in the sealed cylinder is condensed into liquid helium to immerse the superconducting switch at the bottom of the sealed cylinder, so as to fully cool each part of the superconducting switch and timely take away local heat.
[0006] In order to achieve the above purpose, the application adopts the following technical scheme:
[0007] A superconducting switch with a sealed cylinder is composed of a superconducting switch body, an upper condensing plate and a stainless steel straight cylinder.
[0008] The superconducting switch body is placed at the bottom of the stainless steel straight cylinder, and the lower flange of the superconducting switch body is sealingly welded with the lower end of the stainless steel straight cylinder.
[0009] The upper condensing plate is located at the upper part of the stainless steel straight cylinder and is sealingly welded with the upper end of the stainless steel straight cylinder.
[0010] The stainless steel straight cylinder, the lower flange of the superconducting switch body and the upper condensing plate jointly form the sealed cylinder.
[0011] The sealed cylinder is filled with 10-15 atmospheres of helium gas, and the helium gas is condensed into liquid helium by the upper condensing plate and flows to the bottom of the sealed cylinder to immerse the superconducting switch body to achieve overall cooling and local heat removal.
[0012] In the above technical scheme, the superconducting switch body comprises:
[0013] The coil framework is made of red copper material and is a cylinder with flanges at both ends, and the diameter of the lower end flange is larger than that of the upper end flange.
[0014] The superconducting coil and the heating wire coil are both wound on the coil framework, and the superconducting coil is located inside the heating wire coil; the superconducting coil and the heating wire coil are both non-inductive coils, and are wound by double winding method to eliminate inductive effect.
[0015] In the above technical scheme, the double winding method of the non-inductive coil comprises: fixing the midpoint of the winding wire to the end of the coil framework, and winding the two wires synchronously, so that the input end and the output end are led out in the same direction.
[0016] In the above technical solution, the upper condensing plate is made of red copper material, the middle region of the upper condensing plate extends a heat-conducting connecting column, the upper end of the heat-conducting connecting column is provided with a fixed flange for connecting the superconducting magnet, the cross-sectional area of the heat-conducting connecting column is adjustable to control the heat conduction between the superconducting switch and the superconducting magnet, and a copper pipe is inserted into the upper condensing plate to inject high-pressure helium gas into the sealed cylinder and realize sealing by flattening the upper end of the copper pipe.
[0017] In the above technical solution, the cross-sectional area of the heat-conducting connecting column is designed as a stepwise adjustable structure to adapt to different heat conduction requirements.
[0018] In the above technical solution, the superconducting coil inlet and outlet wire passes through the upper condensing plate through a ceramic block and is insulated from the upper condensing plate, and the inlet and outlet wire and the ceramic block are sealed and welded by sintering.
[0019] In the above technical solution, the heating wire coil inlet wire is connected with the inlet wire of the superconducting coil, and the outlet wire is directly connected with the inner wall of the stainless steel straight cylinder; the positive electrode of the external power supply is connected with the inlet wire of the superconducting coil inlet and outlet wire, and the negative electrode is connected with the outer wall of the stainless steel straight cylinder to simplify the power supply structure.
[0020] In the above technical solution, the helium gas pressure in the sealed cylinder is 12 atmospheres to balance the condensation efficiency and thermal stability.
[0021] In the above technical solution, the inner wall of the stainless steel straight cylinder is polished to improve the flow efficiency of liquid helium.
[0022] In the above technical solution, the vacuum electron beam welding is used for the welding of the lower flange of the superconducting switch body and the stainless steel straight cylinder to ensure the sealing property.
[0023] Beneficial effects:
[0024] 1. Efficient cooling and thermal disturbance suppression:
[0025] The high-pressure helium gas in the sealed cylinder is condensed into liquid helium to soak the superconducting switch body, realizing all-around cooling and timely leading away of local heat to avoid instability of the superconducting state caused by thermal disturbance.
[0026] 2. Simplified power supply and structure optimization:
[0027] The power supply of the heating wire coil is realized through the shared inlet wire and the cylinder wall conductive path, without the need of additional threading holes, thus simplifying the structure and improving the sealing reliability.
[0028] 3. Precise regulation of heat conduction:
[0029] By adjusting the cross-sectional area of the heat-conducting connecting column, the heat conduction between the superconducting switch and the magnet is dynamically controlled to balance the cooling efficiency and heating isolation requirements.
[0030] 4. Strong anti-interference capability:
[0031] The inductive coil design eliminates the inductive reactance effect, and combined with liquid helium immersion cooling, it enables the superconducting switch to maintain stable operation under strong electromagnetic disturbances. Attached Figure Description
[0032] Figure 1 This is a schematic diagram of the superconducting switch structure according to an embodiment of the present invention.
[0033] In the diagram: 1-Superconducting switch body, 2-Superconducting coil, 3-Heating wire coil, 4-Coil frame, 5-Superconducting coil inlet and outlet wires, 6-Heating wire coil inlet and outlet wires, 7-Stainless steel cylinder, 8-Ceramic block, 9-Upper condenser plate, 10-Copper tube, 11-Heat-conducting connecting column, 12-Fixing flange. Detailed Implementation
[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. However, the following embodiments are only for explaining the present invention, and the scope of protection of the present invention should include all the contents of the claims. Moreover, through the description of the following embodiments, those skilled in the art can fully implement all the contents of the claims of the present invention.
[0035] Example
[0036] As attached Figure 1 As shown, the superconducting switch of the present invention comprises a superconducting switch body 1, an upper condenser plate 9, and a stainless steel cylinder 7. The superconducting switch body 1 is placed at the bottom of the stainless steel cylinder 7, and the lower flange of the superconducting switch body 1 is sealed and welded to the lower end of the stainless steel cylinder 7. The upper condenser plate 9 is located at the upper part of the stainless steel cylinder 7 and is sealed and welded to the upper end of the stainless steel cylinder 7. The stainless steel cylinder 7, the lower flange of the superconducting switch body 1, and the upper condenser plate 9 form a sealed cylinder. The sealed cylinder is filled with helium gas at 10-15 atmospheres. The helium gas is condensed into liquid helium by the upper condenser plate 9 and flows to the bottom of the sealed cylinder to immerse the superconducting switch body 1, thereby fully cooling all parts of the superconducting switch body 1 and removing local heat in a timely manner.
[0037] The superconducting switch body 1 of this invention consists of a coil frame 4, a superconducting coil 2, and a heating wire coil 3. The coil frame 4 is a cylinder made of copper with flanges at both ends, and the diameter of the lower flange is larger than that of the upper flange. The superconducting coil 2 and the heating wire coil 3 are both wound on the coil frame 4, with the superconducting coil 2 located inside the heating wire coil 3. Both the superconducting coil 2 and the heating wire coil 3 are inductive coils. An inductive coil is a coil with an inductance coefficient of zero or close to zero, the purpose of which is to utilize only its impedance effect to eliminate its inductive reactance effect on the circuit. The inductive coil can be wound using a double-winding method, where the wires used for winding are joined together at the midpoint, and the midpoint is fixed at a certain position at the end of the superconducting switch frame. Then, the two strands are wound simultaneously, and after winding, the input and output ends of the coil are led out simultaneously.
[0038] The upper condensing plate 9 is made of red copper, and a heat-conducting connecting column 11 is extended from the middle region of the upper condensing plate 9. The upper end of the heat-conducting connecting column 11 is provided with a fixing flange 12 for fixing connection with the superconducting magnet. The heat conduction between the superconducting switch and the superconducting magnet can be adjusted by adjusting the sectional area of the heat-conducting connecting column 11. A copper pipe 10 is inserted into the upper condensing plate 9. The high-pressure helium gas is injected into the sealed cylinder through the copper pipe 10, and then the upper end of the copper pipe 10 is flattened to realize the sealing of the copper pipe 10.
[0039] In order to realize the electrical connection between the superconducting coil 2 and the superconducting magnet, the superconducting coil inlet and outlet wire 5 passes through the upper condensing plate 9 through a ceramic block 8 and is insulated from the upper condensing plate 9. The superconducting coil inlet and outlet wire 5 and the ceramic block 8 are sintered to achieve sealed welding.
[0040] In order to realize the power supply of the heating wire coil 3 from the external power supply, the inlet wire of the heating wire coil inlet and outlet wire 6 is connected with the inlet wire of the superconducting coil inlet and outlet wire 5, and the outlet wire of the heating wire coil inlet and outlet wire 6 is directly connected to the inner wall of the stainless steel straight cylinder 7. The positive electrode of the power supply for supplying power to the heating wire coil 3 from the external power supply is connected to the inlet wire of the superconducting coil inlet and outlet wire 5, and the negative electrode is connected to the outer wall of the stainless steel straight cylinder 7. In this way, the heating wire coil inlet and outlet wire 6 does not need to pass through the upper condensing plate 9, which simplifies the structure of the superconducting switch.
[0041] When the heating wire coil 3 is powered, the heating wire coil 3 generates heat to raise the temperature of the entire superconducting switch body 1; when the temperature of the superconducting switch body 1 is higher than the critical temperature of the superconducting coil (i.e. the temperature at which the superconducting coil changes from a superconducting state to a normal state), the superconducting switch body 1 changes from a superconducting state to a normal state. At this time, the liquid helium in the sealed cylinder will all be gasified into high-pressure helium gas. Thus, the heat transfer of the superconducting switch to the superconducting magnet through the channel composed of the high-pressure helium gas and the upper condensing plate is effectively reduced.
[0042] When the heating wire coil is not powered, the helium gas in the sealed cylinder will gradually be condensed into liquid helium by the upper condensing plate and flow to the bottom of the sealed cylinder, thereby soaking the superconducting switch body and fully cooling each part of the superconducting switch body and timely removing the local heat.
[0043] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.
Claims
1. A superconducting switch with a sealed cylinder, characterized in that, It consists of a superconducting switch body (1), an upper condenser plate (9) and a stainless steel cylinder (7); The superconducting switch body (1) is placed at the bottom of the stainless steel cylinder (7), and the lower flange of the superconducting switch body (1) is sealed and welded to the lower end of the stainless steel cylinder (7). The upper condenser plate (9) is located on the upper part of the stainless steel cylinder (7) and is sealed and welded to the upper end of the stainless steel cylinder (7); The stainless steel straight cylinder (7), the lower flange of the superconducting switch body (1) and the upper condenser plate (9) together form a sealing cylinder; The sealed cylinder is filled with helium gas at 10-15 atmospheres. The helium gas is condensed into liquid helium by the upper condenser plate (9) and flows to the bottom of the sealed cylinder to soak the superconducting switch body (1) to achieve overall cooling and local heat dissipation.
2. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The superconducting switch body (1) includes: The coil frame (4) is made of copper and has flanges at both ends. The diameter of the lower flange is larger than that of the upper flange. The superconducting coil (2) and the heating wire coil (3) are both wound on the coil frame (4), and the superconducting coil (2) is located inside the heating wire coil (3); Both the superconducting coil (2) and the heating wire coil (3) are inductive coils, and are wound using a double-winding method to eliminate the inductive reactance effect.
3. A superconducting switch with a sealed cylinder according to claim 2, characterized in that, The double-winding method of the non-inductive coil includes: fixing the midpoint of the winding wire to the end of the coil frame (4), winding the two wires synchronously, so that the input end and the output end are led out in the same direction.
4. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The upper condenser plate (9) is made of copper. A heat-conducting connecting column (11) extends from the middle area of the upper condenser plate (9). A fixed flange (12) is provided at the upper end of the heat-conducting connecting column (11) for connecting the superconducting magnet. The cross-sectional area of the thermally conductive connecting post (11) is adjustable to control the thermal conductivity between the superconducting switch and the superconducting magnet; A copper tube (10) is inserted into the upper condenser plate (9) to inject high-pressure helium into the sealing cylinder and to achieve sealing by flattening the upper end of the copper tube (10).
5. A superconducting switch with a sealed cylinder according to claim 4, characterized in that, The cross-sectional area of the thermally conductive connecting column (11) is designed as a stepped adjustable structure to adapt to different thermal conductivity requirements.
6. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The input and output lines of the superconducting coil (2) pass through the ceramic block (8) and exit the upper condenser plate (9), and are insulated from the upper condenser plate (9); the input and output lines and the ceramic block (8) are sealed and welded by sintering.
7. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The inlet wire of the heating wire coil (3) is connected to the inlet wire of the superconducting coil (2), and its outlet wire is directly connected to the inner wall of the stainless steel cylinder (7); the positive terminal of the external power supply is connected to the inlet wire of the superconducting coil (2), and the negative terminal is connected to the outer wall of the stainless steel cylinder (7) to simplify the power supply structure.
8. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The helium pressure inside the sealed cylinder is 12 atmospheres to balance condensation efficiency and thermal stability.
9. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The inner wall of the stainless steel straight cylinder (7) is polished to improve the efficiency of liquid helium flow.
10. A superconducting switch with a sealed cylinder according to claim 1, characterized in that, The welding of the lower flange of the superconducting switch body (1) to the stainless steel cylinder (7) is carried out by vacuum electron beam welding to ensure sealing.