A testing device and testing method for superconducting joints

Abstract

The application relates to the technical field of superconducting detection, and discloses a testing device and a testing method for a superconducting joint. The testing device comprises a testing Dewar, two electrode assemblies, a cooling structure, a signal leading structure and a supporting structure. The testing Dewar comprises a first half shell and a second half shell which are sealingly assembled to wrap the superconducting joint. The two electrode assemblies respectively extend into the interior of the testing Dewar and are connected with the two ends of the superconducting joint in a one-to-one correspondence, and are used for supplying power to the superconducting joint. The cooling structure comprises an electrode cooling helium pipe and a joint cooling helium pipe. The electrode cooling helium pipe is coiled outside the two electrode assemblies and is led out from the two ends of the testing Dewar. The joint cooling helium pipe is in communication with a liquid cooling inlet pipe of the superconducting joint. The signal leading structure penetrates the testing Dewar and is internally provided with a plurality of signal lines which are used for transmitting temperature signals or potential signals. The supporting structure is connected with the bottom of the testing Dewar.

Description

Technical Field

[0001] This invention relates to the technical field of superconducting testing, and in particular to a testing device and method for superconducting joints. Background Technology

[0002] As one of the core components of future clean energy, the stable operation of the superconducting magnet system in a large magnetic confinement fusion reactor directly determines the overall safety and reliability of the reactor. The superconducting joint, a key component connecting the cryogenic superconducting busbar in the superconducting magnet system, typically connects to tens of meters of cryogenic superconducting busbar at both ends. Because the superconducting joint is fixed after installation and integration, its final operational performance can only be tested during the actual operation of the entire fusion reactor.

[0003] If problems with low-temperature current carrying capacity, such as poor connection performance and insufficient stability, are found in the superconducting joint during formal operation, the subsequent maintenance or replacement work will be extremely difficult due to the special low-temperature and confined space environment in which the superconducting joint is located, and the fact that the joint surface has undergone complex insulation treatment. This will not only lead to the shutdown and maintenance of the fusion reactor, causing huge economic losses, but may also affect the long-term operational safety of the reactor and restrict the industrial application of large magnetic confinement fusion reactors.

[0004] Therefore, there is an urgent need for a solution that can test the cryogenic current-carrying performance of superconducting joints after installation and integration but before formal operation. Summary of the Invention

[0005] The technical problem to be solved by this invention is: how to test the low-temperature current-carrying performance of a superconducting connector after installation and integration and before its formal operation.

[0006] To address the aforementioned technical problems, this invention provides a testing device and method for superconducting joints.

[0007] A first aspect of the present invention provides a testing device for a superconducting connector, comprising: a test Dewar, the test Dewar including a first half-shell and a second half-shell sealed together, the first half-shell and the second half-shell enclosing the superconducting connector; two electrode assemblies, the two electrode assemblies extending into the interior of the test Dewar and connected one-to-one with the two ends of the superconducting connector, the two electrode assemblies being used to supply power to the superconducting connector; a cooling structure, the cooling structure including an electrode cooling helium tube and a connector cooling helium tube, the electrode cooling helium tube being coiled around the outside of the two electrode assemblies, and both ends of the electrode cooling helium tube extending out from the test Dewar, the connector cooling helium tube being connected to the liquid cooling inlet pipe of the superconducting connector; a signal lead-out structure, the signal lead-out structure penetrating the test Dewar, the signal lead-out structure having a plurality of signal lines passing through it, the signal lines being used to transmit temperature signals or potential signals; and a support structure, the support structure being connected to the bottom of the test Dewar and used to support the test Dewar.

[0008] In one embodiment, the testing apparatus further includes a cold screen and a connecting rod. The cold screen is disposed inside the test Dewar, one end of the connecting rod is connected to the inner wall of the test Dewar, and the other end of the connecting rod is connected to the outer wall of the cold screen. The cold screen is used to cover the superconducting connector, the cooling structure, and the portion of the electrode assembly that is coiled around the electrode cooling helium tube.

[0009] In one embodiment, a liquid nitrogen cooling tube for the cold screen is coiled between the outer wall of the cold screen and the test Dewar, with both ends of the liquid nitrogen cooling tube extending from the test Dewar.

[0010] In one embodiment, the test Dewar is equipped with a liquid helium cooling flange and a liquid nitrogen cooling flange. The electrode cooling helium tube and the connector cooling helium tube are both connected to the external liquid helium system through the liquid helium cooling flange, and the cold screen liquid nitrogen cooling tube is connected to the external liquid nitrogen system through the liquid nitrogen cooling flange.

[0011] In one embodiment, a helium-cooled vacuum partition is provided inside the liquid helium cooling flange, and a nitrogen-cooled vacuum partition is provided inside the liquid nitrogen cooling flange. The helium-cooled vacuum partition is used to fill the gap between the liquid helium cooling flange and the pipeline, and the nitrogen-cooled vacuum partition is used to fill the gap between the liquid nitrogen cooling flange and the pipeline.

[0012] In one embodiment, the connecting rod, the helium-cooled vacuum partition, and the nitrogen-cooled vacuum partition are all made of G10 material.

[0013] In one embodiment, the test Dewar is provided with a vacuum pump assembly connecting flange and an electronic vacuum gauge flange. The vacuum pump assembly connecting flange is used to connect the test Dewar to an external vacuum pump assembly, and the electronic vacuum gauge flange is used to connect an electronic vacuum gauge, which is used to measure the vacuum level of the test Dewar.

[0014] In one embodiment, the electrode assembly includes an electrode clamp and a copper electrode, the electrode clamp being used to clamp and fix the superconducting connector and the copper electrode.

[0015] In one embodiment, the signal output structure includes a jet flange and a signal line vacuum jet connector. The jet flange is fixed to the test Dewar, and the signal line vacuum jet connector extends from the test Dewar through the jet flange. Several signal lines are connected to the signal line vacuum jet connector, which is used to transmit temperature signals or potential signals to external devices.

[0016] A second aspect of the present invention provides a testing method for a superconducting connector, comprising: S1, assembling a test Dewar onto the superconducting connector and adjusting the position of the support structure to adapt the test Dewar to the position of the superconducting connector; S2, installing an electrode cooling helium tube and a connector cooling helium tube, and connecting the electrode cooling helium tube and the connector cooling helium tube to an external liquid helium system respectively; S3, installing an electrode assembly and a signal lead-out structure; S4, activating the external liquid helium system to bring the superconducting connector to a preset temperature, while actively cooling the electrode assembly to establish a low-temperature superconducting environment; S5, applying a preset current to the electrode assembly and collecting test data to analyze the low-temperature current-carrying performance and stability of the superconducting connector; S6, after the test is completed, disassembling the test system and sealing the pipeline to restore the superconducting connector to its original state.

[0017] The testing device and method for superconducting joints according to embodiments of the present invention have the following advantages compared with the prior art: This invention uses a split-type test Dewar shroud to house the superconducting connector, eliminating the need to disassemble the connector. Combined with a liquid helium pipeline, it creates a cryogenic, current-carrying, and signal-detecting environment in the area of ​​the superconducting connector under test. This allows the superconducting connector to achieve a superconducting state and complete current-carrying operation within this created test area. The performance of the superconducting connector in the superconducting operating state is then tested. This on-site construction transforms the testing of the superconducting connector performance, which would otherwise be impossible to conduct in advance, into an on-site online test.

[0018] Simultaneously, liquid helium is introduced into both the electrode cooling helium tube and the connector cooling helium tube, enabling synchronous cooling of the electrode assembly and the superconducting connector. This reduces the temperature difference between the electrode assembly and the superconductor, preventing the electrode assembly from carrying away the superconductor's cooling capacity. Combined with the test Dewar, this significantly reduces liquid helium loss, achieving efficient cooling while enabling on-site testing. Furthermore, the support structure reduces the stress on the superconducting connector, and the test signal is extracted through the signal extraction structure. Attached Figure Description

[0019] Figure 1 This is an exemplary assembly diagram of a testing device for a superconducting connector, as shown in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the internal structure of a testing device for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the cold screen structure of a testing device for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0022] Figure 4 This is a cross-sectional schematic diagram of a testing device for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0023] Figure 5This is a schematic diagram of the structure of an electrode cooling helium tube for a test device for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the structure of a liquid nitrogen cooling tube for a testing device for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0025] Figure 7 This is a schematic flowchart illustrating a testing method for a superconducting connector, as exemplarily shown in an embodiment of the present invention.

[0026] Figure label: 1. Test Dewar, 2. Electrode assembly, 3. Cooling structure, 4. Signal lead-out structure, 5. Support structure, 6. Cold shield, 7. Connecting rod, 8. Electronic vacuum gauge, 9. Signal line vacuum connector, 10. Superconducting connector, 11. First half-shell, 12. Second half-shell, 13. Liquid helium cooling flange, 14. Liquid nitrogen cooling flange, 15. Vacuum pump assembly connecting flange, 16. Electronic vacuum gauge flange, 17. Connecting flange, 21. Electrode clamp, 22. Copper electrode, 31. Electrode cooling helium tube, 32. Connector cooling helium tube, 41. Signal line, 61. Cold shield liquid nitrogen cooling tube, 131. Helium-cooled vacuum isolation, 141. Nitrogen-cooled vacuum isolation, 311. Electrode liquid helium inlet, 312. Electrode liquid helium outlet, 611. Liquid nitrogen cooling tube inlet, 612. Liquid nitrogen cooling tube outlet. Detailed Implementation

[0027] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0028] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various structures, these structures should not be limited to these terms. These terms are only used to distinguish structures of the same type from each other. For example, a first structure may also be referred to as a second structure without departing from the scope of this invention, and similarly, a second structure may also be referred to as a first structure. Depending on the context, the word "if" as used herein can be interpreted as "when," "when," or "in response to determination."

[0029] Nuclear energy is a type of clean energy with great development potential. Large magnetic confinement fusion reactors are one of the core components. Large magnetic confinement fusion reactors have a large current carrying capacity and are highly dependent on superconducting systems. The stable operation of the superconducting magnet system directly determines the overall safety and reliability of large magnetic confinement fusion reactors.

[0030] The superconducting joint is a key component connecting the cryogenic superconducting busbar. The superconducting busbar is quite long, and after installation, the superconducting joint forms an integral fixed assembly with the superconducting busbar. Testing the superconducting performance requires cryogenic conditions. Since the superconducting joint is located on the busbar and cannot be tested independently, it can only be tested when the entire fusion reactor is in operation.

[0031] However, if problems such as poor connection performance and insufficient stability are found in the superconducting joint during actual operation, the subsequent maintenance or replacement work will be extremely difficult due to the special low temperature and confined space environment in which the superconducting joint is located, and the fact that the joint surface has been subjected to complex insulation treatment. This will not only lead to the shutdown and maintenance of the fusion reactor, causing huge economic losses, but may also affect the long-term operational safety of the reactor and restrict the industrial application of large magnetic confinement fusion reactors.

[0032] In order to test the performance of the superconducting joint 10 before confirming its operation, such as Figure 1 As shown, the present invention provides a testing device for a superconducting connector 10, comprising: a test dewar 1, two electrode assemblies 2, a cooling structure 3, a signal output structure 4, and a support structure 5.

[0033] The test Dewar 1 comprises a sealed first half-shell 11 and a second half-shell 12, which enclose the superconducting connector 10. Two electrode assemblies 2 extend into the interior of the test Dewar 1 and are connected to the two ends of the superconducting connector 10 respectively. The two electrode assemblies 2 are used to supply power to the superconducting connector 10. Figure 5 As shown, the cooling structure 3 includes an electrode cooling helium tube 31 and a connector cooling helium tube 32. The electrode cooling helium tube 31 is coiled around the outside of the two electrode assemblies 2, and both ends of the electrode cooling helium tube 31 extend from the test Dewar 1. The connector cooling helium tube 32 is connected to the liquid cooling inlet pipe of the superconducting connector 10. A signal output structure 4 penetrates the test Dewar 1, and several signal lines 41 are threaded inside the signal output structure 4. The signal lines 41 are used to transmit temperature signals or potential signals. The support structure 5 is connected to the bottom of the test Dewar 1 and is used to support the test Dewar 1.

[0034] This invention allows for assembly of the superconducting connector 10 after it is put into operation but before insulation and other processing steps. It uses a split-type test Dewar 1 (first half-shell 11 and second half-shell 12) to cover the connector 10, enabling assembly without disassembling the connector 10. Furthermore, a liquid helium pipeline is used to create a cryogenic, current-carrying, and signal-detecting environment in the area of ​​the superconducting connector 10 under test. This allows the connector 10 to achieve a superconducting state and complete current-carrying operation within this created test area. The performance of the superconducting connector 10 in its superconducting operating state is then tested. This on-site construction method transforms a test that would normally require insulation and other processes before formal production into an on-site, online test.

[0035] The test can be conducted on-site thanks to the simultaneous introduction of liquid helium into the electrode cooling helium tube 31 and the connector cooling helium tube 32, which allows the electrode assembly 2 and the superconducting connector 10 to be cooled synchronously. While achieving a low-temperature superconducting environment, the temperature difference between the electrode assembly 2 and the superconductor is reduced, preventing the electrode assembly 2 from taking away the coolness of the superconductor. Combined with the test Dewar 1, the loss of liquid helium is greatly reduced.

[0036] Furthermore, the support structure 5 can appropriately reduce the stress on the superconducting connector 10. The test signal is led out through the signal lead-out structure 4, eliminating the need to place the signal processing equipment in the test environment. This reduces the impact of the operating heat of the signal processing equipment on the test environment and further reduces the stress on the superconducting connector 10.

[0037] It is understood that, in one embodiment of the present invention, a support structure 5 with adjustable height and angle can be used to match the position of the superconducting connector 10. By adjusting the height vertically, it can accommodate superconducting connectors 10 of different sizes and heights. By adaptively adjusting the tilt angle, interference between the test Dewar and the superconducting connector can be avoided as much as possible. Reducing interference not only improves the adaptability of the device but also reduces the loss of cold energy.

[0038] In an exemplary assembly method, a sealing ring can be provided on the mating surface of the first half-shell 11 and the second half-shell 12, and the sealing assembly is achieved by fastening with a flanged sealing flange and bolt assembly.

[0039] In an exemplary connection structure, the connector cooling helium tube 32 can be connected to the existing piping of the superconducting connector 10 via a tee.

[0040] Furthermore, to further stabilize the testing environment and make it closer to the carrying capacity of a live, operational environment, in one embodiment of the present invention, as follows: Figure 2 and Figure 3 The test apparatus shown also includes a cold screen 6 and a connecting rod 7. The cold screen 6 is located inside the test Dewar 1. One end of the connecting rod 7 is connected to the inner wall of the test Dewar 1, and the other end of the connecting rod 7 is connected to the outer wall of the cold screen 6. The cold screen 6 is used to cover the superconducting connector 10, the cooling structure 3, and the part of the electrode assembly 2 that is coiled around the electrode cooling helium tube 31.

[0041] Understandable Figure 2The test Dewar 1 and the cold screen 6 are shown in cross-section, while other structures retain their complete appearance to highlight the assembly relationship of the internal structures. As can be seen in the figure, the electrode liquid helium inlet pipe 311 and the electrode liquid helium outlet pipe 312 are located outside the test Dewar 1. Due to the long length of the superconducting connector 10 and its connected busbar, the electrode cooling helium pipe 31 cannot be directly fitted onto the electrode assembly 2. Therefore, in this invention, the electrode cooling helium pipe 31 enters the test Dewar 1 through the electrode liquid helium inlet pipe 311, coils around the two electrode assemblies 2, and then exits from the test Dewar 1 through the electrode liquid helium outlet pipe 312.

[0042] A cold shield 6 is used to cover the superconducting connector 10, the cooling structure 3, and the part of the electrode assembly 2 that is coiled around the electrode cooling helium tube 31. Even if there is a cold gas leak in these structures cooled by liquid helium, the heat will leak to the cold shield 6 first. Since the cold shield 6 and the test Dewar 1 are arranged at intervals, and the cold shield 6 is also cooled by liquid nitrogen, the low temperature difference reduces the rate of heat exchange, thus further reducing the possibility of heat leakage to the outside.

[0043] In addition, the connection between the cold shield 6 and the test Dewar 1 is achieved by using a connecting rod 7, rather than a large-area connection, which can effectively reduce heat leakage.

[0044] In a further embodiment, the cold screen 6 can be wrapped with 30 layers of multi-layer insulation material to further reduce heat leakage.

[0045] It is understandable that, in order to further improve the stability of the testing environment and reduce heat leakage, in one embodiment of the present invention, such as Figure 4 As shown, the test Dewar 1 is equipped with a vacuum pump assembly connecting flange 15 and an electronic vacuum gauge flange 16. The vacuum pump assembly connecting flange 15 is used to connect the test Dewar 1 to an external vacuum pump assembly, and the electronic vacuum gauge flange 16 is used to connect an electronic vacuum gauge 8. The electronic vacuum gauge 8 is used to measure the vacuum level of the test Dewar 1.

[0046] After the test Dewar 1 is evacuated, a vacuum environment is formed inside the test Dewar 1, reducing the amount of gaseous media such as air, thereby reducing the heat exchange efficiency. Therefore, the probability of heat leakage between the superconducting connector 10 and the cold screen 6, and between the cold screen 6 and the test Dewar 1, is greatly reduced, which can make the superconducting connector 10 maintain a relatively stable superconducting state for a long time.

[0047] like Figure 3 and Figure 6 As shown, in another embodiment of the present invention, a liquid nitrogen cooling tube 61 is also coiled between the outer wall of the cold screen 6 and the test Dewar 1, with both ends of the liquid nitrogen cooling tube 61 extending from the test Dewar 1.

[0048] Understandable Figure 3The test Dewar 1, which is covered on the outside, is hidden, while the internal structure such as the cold screen 6 is retained. The assembly relationship between the cold screen 6 and the cold screen liquid nitrogen cooling pipe 61 coiled on it can be clearly seen. For ease of understanding, the inlet end of the cold screen liquid nitrogen cooling pipe 61 is marked as liquid nitrogen cooling pipe inlet 611, and the outlet end is marked as liquid nitrogen cooling pipe outlet 612. Both ends pass through the test Dewar 1 to reach the outside to connect to the external liquid nitrogen system.

[0049] By winding the liquid nitrogen cooling pipe 61 around the outer wall of the cold screen 6 and introducing liquid nitrogen into the pipe, another cooling measure is provided, which can "supplement the cooling" of the test environment where the superconducting connector 10 is located, and further improve the stability of the test environment.

[0050] It is understood that, in order to reduce the heat exchange rate, the nitrogen-cooled and helium-cooled related pipes in this invention can be installed in different holes of the test Dewar 1 to reduce the possibility of contact.

[0051] As in one embodiment, such as Figures 1-4 As shown in any of the attached figures, the test Dewar 1 is equipped with a liquid helium cooling flange 13 and a liquid nitrogen cooling flange 14. The electrode cooling helium tube 31 and the connector cooling helium tube 32 are both connected to the external liquid helium system through the liquid helium cooling flange 13, and the cold screen liquid nitrogen cooling tube 61 is connected to the external liquid nitrogen system through the liquid nitrogen cooling flange 14.

[0052] Flange structures can improve the structural strength of the connection between the pipe and the test Dewar 1. In this invention, flange structures can be used between the electrode assembly 2 and each pipe and the test Dewar 1. These flange structures can be further made of ceramic insulating material to reduce the impact of leakage current.

[0053] After setting up the flange structure, the Dewar 1 was tested and found to have a reasonable improvement in structural strength compared to a standalone cylindrical shell.

[0054] In one embodiment of the present invention, such as Figure 4 As shown, a helium-cooled vacuum partition 131 may be provided inside the liquid helium cooling flange 13, and a nitrogen-cooled vacuum partition 141 may be provided inside the liquid nitrogen cooling flange 14. The helium-cooled vacuum partition 131 is used to fill the gap between the liquid helium cooling flange 13 and the pipeline, and the nitrogen-cooled vacuum partition 141 is used to fill the gap between the liquid nitrogen cooling flange 14 and the pipeline.

[0055] Using helium-cooled vacuum partition 131 and nitrogen-cooled vacuum partition 141 to fill the gaps can not only reduce gaps and improve the vacuum effect, but also achieve heat insulation and reduce heat leakage from the helium-cooled pipes and nitrogen-cooled pipes to the test Dewar 1.

[0056] Specifically, in one embodiment of the present invention, the connecting rod 7, the helium-cooled vacuum partition 131, and the nitrogen-cooled vacuum partition 141 are all made of G10 material.

[0057] G10 material is a rigid laminate made of glass fiber cloth and epoxy resin under high temperature and pressure. It belongs to high-strength insulating composite materials, has high dielectric strength, is stable in high-frequency and high-voltage environments, and has excellent insulation capabilities. It also features low thermal conductivity, lightweight, and low-temperature resistance, which aligns with the testing requirements of the superconducting connector 10 in this invention.

[0058] In one embodiment of the present invention, such as Figure 2 The electrode assembly 2 in this invention may include an electrode clamp 21 and a copper electrode 22. The electrode clamp 21 is used to clamp and fix the superconducting connector 10 and the copper electrode 22.

[0059] The copper electrode 22 and the superconducting connector 10 are connected by a clamping method, which allows for fast assembly and stable connection performance.

[0060] To accommodate the vacuum structure, in one embodiment of the present invention, the signal lead-out structure 4 may include a jet flange 17 and a signal line vacuum jet connector 9. The jet flange 17 is fixed on the test Dewar 1, and the signal line vacuum jet connector 9 extends from the test Dewar 1 through the jet flange 17. Several signal lines 41 are connected to the signal line vacuum jet connector 9, which is used to transmit temperature signals or potential signals to external devices.

[0061] Compared to directly leading the signal line 41 to the outside of the test Dewar 1, using the signal line vacuum connector 9 can achieve a certain degree of sealing performance while conducting electrical signals inside and outside. Moreover, compared to the signal line 41 alone, the signal line vacuum connector 9 has a certain structural strength and will not easily break or leak electricity, making it safer. In addition, most signal line vacuum connectors 9 have built-in signal shielding structures, which can reduce the influence of the test Dewar 1 and other structures on the electrical signal and ensure measurement accuracy.

[0062] If the number of terminals of the signal line vacuum connector 9 used is greater than the number of current signal lines 41, then when adding test items and signal lines 41 in the future, rapid expansion can be achieved without changing the specifications, and without affecting the test environment.

[0063] Correspondingly, such as Figure 7 As shown, the present invention also provides a testing method for a superconducting connector 10, the testing method including: S1. Assemble the test Dewar 1 to the superconducting connector 10 and adjust the position of the support structure 5 to make the test Dewar 1 and the superconducting connector 10 fit together.

[0064] S2. Install electrode cooling helium tube 31 and connector cooling helium tube 32, and connect electrode cooling helium tube 31 and connector cooling helium tube 32 to the external liquid helium system respectively.

[0065] S3, Install electrode assembly 2 and signal lead-out structure 4.

[0066] S4. Start the external liquid helium system to bring the superconducting connector 10 to the preset temperature, and at the same time actively cool the electrode assembly 2 to establish a low-temperature superconducting environment.

[0067] S5. Apply a preset current to electrode assembly 2 and collect test data to analyze the low-temperature current-carrying performance and stability of superconducting connector 10.

[0068] S6. After the test is completed, disassemble the test system and seal the pipeline, and restore the superconducting connector 10 to its original state.

[0069] Based on this, in a further embodiment, in step S2, the electrode cooling helium tube 31 and the connector cooling helium tube 32 are installed, and after the electrode cooling helium tube 31 and the connector cooling helium tube 32 are connected to the external liquid helium system respectively, the airtightness of each pipe connection is tested.

[0070] If a vacuum pump assembly is introduced, the test method between steps S3 and S4 also includes: starting the vacuum pump assembly to bring the interior of the test Dewar 1 to a preset vacuum level and maintain stability.

[0071] In one embodiment, if the testing device further includes a cold screen 6 and a connecting rod 7, then step S2 may further include: installing the cold screen liquid nitrogen cooling pipe 61 and connecting the cold screen liquid nitrogen cooling pipe 61 to an external liquid nitrogen system.

[0072] Correspondingly, step S4 also includes: first, starting the external liquid nitrogen system to bring the temperature inside the test Dewar 1 to the preset temperature, then starting the external liquid helium system to bring the superconducting connector 10 to the preset temperature, and simultaneously actively cooling the electrode assembly 2 to establish a low-temperature superconducting environment.

[0073] Understandably, if the test device needs to be removed, the detachable connection structure can be removed directly. To reduce leakage, the connection between the connector cooling helium tube 32 and the superconducting structure can be welded. Therefore, during disassembly, the connector cooling helium tube 32 can be cut and the welded joint can be sealed to restore the superconducting connector 10 to its original state.

[0074] It is understood that the testing method in this invention includes all the technical features of the testing device. Therefore, all embodiments of the testing device of this invention and their beneficial effects are applicable to the testing method in this invention, and this invention will not elaborate on them one by one.

[0075] In summary, this invention provides a testing device and method for a superconducting connector 10. The core of this invention lies in the integration of a split-type testing Dewar 1 structure with a helium-nitrogen cooling system. Through the efficient sealing of the helium-cooled pipes, nitrogen-cooled pipes, vacuum sealing structure, and flange materials, stable operation of the superconducting connector 10 in a low-temperature environment is achieved. The non-disassembly assembly method of the split-type testing Dewar 1, combined with the cold shield 6 and the coiled cold nitrogen pipe, effectively reduces heat leakage. Simultaneously, the vacuum insertion design of the signal lead-out structure 4 ensures the stability and sealing of signal transmission.

[0076] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A testing device for superconducting joints, characterized in that, include: Test Dewar (1), the test Dewar (1) includes a first half-shell (11) and a second half-shell (12) that are sealed together, the first half-shell (11) and the second half-shell (12) enclosing the superconducting connector (10). Two electrode assemblies (2) are inserted into the interior of the test Dewar (1) and connected to the two ends of the superconducting connector (10) respectively. The two electrode assemblies (2) are used to supply power to the superconducting connector (10). The cooling structure (3) includes an electrode cooling helium tube (31) and a connector cooling helium tube (32). The electrode cooling helium tube (31) is coiled around the outside of the two electrode assemblies (2), and both ends of the electrode cooling helium tube (31) are led out from the test Dewar (1). The connector cooling helium tube (32) is connected to the liquid cooling inlet of the superconducting connector (10). The electrode cooling helium tube (31) and the connector cooling helium tube (32) are used to simultaneously introduce liquid helium to cool the electrode assembly (2) and the superconducting connector (10) synchronously. The signal lead-out structure (4) penetrates the test Dewar (1), and a plurality of signal lines (41) are provided inside the signal lead-out structure (4). The signal lines (41) are used to transmit temperature signals or potential signals. A support structure (5) is connected to the bottom of the test Dewar (1) and is used to support the test Dewar (1).

2. The testing apparatus according to claim 1, characterized in that, The testing device also includes a cold screen (6) and a connecting rod (7). The cold screen (6) is located inside the test Dewar (1). One end of the connecting rod (7) is connected to the inner wall of the test Dewar (1), and the other end of the connecting rod (7) is connected to the outer wall of the cold screen (6). The cold screen (6) is used to cover the superconducting connector (10), the cooling structure (3), and the portion of the electrode assembly (2) that is coiled around the electrode cooling helium tube (31).

3. The testing apparatus according to claim 2, characterized in that, A liquid nitrogen cooling tube (61) is also coiled between the outer wall of the cold screen (6) and the test Dewar (1), with both ends of the liquid nitrogen cooling tube (61) extending from the test Dewar (1).

4. The testing apparatus according to claim 3, characterized in that, The test Dewar (1) is equipped with a liquid helium cooling flange (13) and a liquid nitrogen cooling flange (14). The electrode cooling helium tube (31) and the connector cooling helium tube (32) are both connected to the external liquid helium system through the liquid helium cooling flange (13). The cold screen liquid nitrogen cooling tube (61) is connected to the external liquid nitrogen system through the liquid nitrogen cooling flange (14).

5. The testing apparatus according to claim 4, characterized in that, The liquid helium cooling flange (13) is provided with a helium-cooled vacuum partition (131), and the liquid nitrogen cooling flange (14) is provided with a nitrogen-cooled vacuum partition (141). The helium-cooled vacuum partition (131) is used to fill the gap between the liquid helium cooling flange (13) and the pipe, and the nitrogen-cooled vacuum partition (141) is used to fill the gap between the liquid nitrogen cooling flange (14) and the pipe.

6. The testing apparatus according to claim 5, characterized in that, The connecting rod (7), the helium-cooled vacuum partition (131), and the nitrogen-cooled vacuum partition (141) are all made of G10 material.

7. The testing apparatus according to claim 1, characterized in that, The test Dewar (1) is provided with a vacuum pump group connecting flange (15) and an electronic vacuum gauge flange (16). The vacuum pump group connecting flange (15) is used to connect the test Dewar (1) to an external vacuum pump group. The electronic vacuum gauge flange (16) is used to connect an electronic vacuum gauge (8). The electronic vacuum gauge (8) is used to measure the vacuum level of the test Dewar (1).

8. The testing apparatus according to claim 1, characterized in that, The electrode assembly (2) includes an electrode clamp (21) and a copper electrode (22), wherein the electrode clamp (21) is used to clamp and fix the superconducting connector (10) and the copper electrode (22).

9. The testing apparatus according to claim 1, characterized in that, The signal lead-out structure (4) includes a jet flange (17) and a signal line vacuum jet connector (9). The jet flange (17) is fixed on the test Dewar (1). The signal line vacuum jet connector (9) extends from the test Dewar (1) through the jet flange (17). Several signal lines (41) are connected to the signal line vacuum jet connector (9). The signal line vacuum jet connector (9) is used to transmit the temperature signal or the potential signal to an external device.

10. A testing method for superconducting joints, characterized in that, The testing apparatus for superconducting joints as described in any one of claims 1 to 9 includes: S1. Assemble the test Dewar (1) onto the superconducting connector (10) and adjust the position of the support structure (5) so that the test Dewar (1) and the superconducting connector (10) are matched. S2. Install the electrode cooling helium tube (31) and the connector cooling helium tube (32), and connect the electrode cooling helium tube (31) and the connector cooling helium tube (32) to the external liquid helium system respectively; S3, Install electrode assembly (2) and signal lead-out structure (4); S4. Start the external liquid helium system and simultaneously introduce liquid helium into the electrode cooling helium tube (31) and the connector cooling helium tube (32) to make the superconducting connector (10) reach the preset temperature, and at the same time actively cool the electrode assembly (2) to establish a low temperature superconducting environment. S5. Apply a preset current to the electrode assembly (2) and collect test data to analyze the low-temperature current carrying performance and stability of the superconducting connector (10); S6. After the test is completed, disassemble the test system and seal the pipeline to restore the superconducting connector (10) to its original state.

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