1. A thermal performance test platform of a self-circulation low-temperature heat pipe is characterized by comprising a rotary bracket (1), a double-screen cryostat (7), a cold source and a current lead (15);

the rotating support (1) is connected with the double-screen cryostat (7) and is used for supporting the double-screen cryostat (7) and driving the double-screen cryostat (7) to rotate;

the double-screen cryostat (7) comprises a vacuum chamber (17), a normal-temperature flange (8) is arranged at the top of the vacuum chamber (17), an external cold screen (9) is arranged inside the vacuum chamber (17), and a top flange (10) of the external cold screen (9) is installed on the normal-temperature flange (8) through a support piece (11);

the normal temperature end of the current lead (15) is arranged on the normal temperature flange (8), and the low temperature end of the current lead (15) is arranged on the top flange (10); the low-temperature end of the current lead (15) is connected with one end of the superconducting segment (16) through the top flange (10), and the other end of the superconducting segment (16) is used for being connected with a tested device;

the normal temperature end of the cold source is connected with a normal temperature flange (8), and the primary refrigeration part of the cold source is connected with a top flange (10) through a plurality of cold guide structures (20).

2. The thermal performance test platform of the self-circulation low-temperature heat pipe as claimed in claim 1, wherein an inner cold screen (12) is arranged inside the outer cold screen (9), a top flange (13) of the inner cold screen (12) is mounted on the top flange (10) through a support (14), and a low-temperature end of the cold source is directly and rigidly connected with the top flange (13) of the inner cold screen (12); the other end of the superconducting segment (16) extends into the internal cooling screen (12) through a top flange (13) of the internal cooling screen (12) and is used for being connected with tested equipment in the internal cooling screen (12).

3. The thermal performance test platform of the self-circulation low-temperature heat pipe as claimed in claim 1, wherein a damping spring is arranged between the normal temperature end of the cold source and the normal temperature flange (8); and the primary refrigeration part of the cold source is in non-contact sealing connection with the top flange (10) through a connecting piece.

4. The thermal performance testing platform of the self-circulation low-temperature heat pipe according to claim 1, 2 or 3, wherein the rotating bracket comprises a driving motor, a gearbox, a supporting frame, a rotating shaft and a bearing fixed supporting leg; the bottom of support frame is equipped with a plurality ofly bearing fixed stay, the top of support frame be equipped with be used for with double screen cryostat connects the rotation axis, driving motor warp the gearbox with the rotation axis is connected.

5. The thermal performance test platform of the self-circulation low-temperature heat pipe according to claim 1, 2 or 3, wherein the normal temperature end of the current lead (15) is a copper cable, and the low temperature end of the current lead (15) is a high-temperature superconducting cable.

6. The platform for testing the thermal performance of the self-circulating low-temperature heat pipe according to claim 1, 2 or 3, wherein the low-temperature end of the current lead (15) is connected with the superconducting segment (16) through solid ceramic aluminum nitride arranged on the top flange (10), so that the top flange (10) is thermally connected with and electrically insulated from the current lead.

7. The thermal performance testing platform of the self-circulating low-temperature heat pipe according to claim 1, 2 or 3, wherein the cold conduction structure (20) is a multi-pair claw type cold conduction structure; the cylinder body of the outer cold shield (9) is connected with the top flange (10) through a plurality of pairs of long soft body high-thermal conductivity braided belts.

8. The thermal performance testing platform of the self-circulating low-temperature heat pipe according to claim 7, wherein a plurality of heating sheets are arranged on the top flange (10) for adjusting the temperature range of the external cold shield.

9. The thermal performance test platform of the self-circulation low-temperature heat pipe according to claim 1, wherein the external cold shield (9) is a 40K aluminum shield; the internal cooling screen (12) is a 4K copper screen.

10. The thermal performance testing platform of the self-circulation low-temperature heat pipe according to claim 1, wherein the current lead (15) is wrapped with a plurality of layers of insulating glue on the outer side.

Background

Superconducting magnets are important devices for high performance electronic accelerators, which behave as conventional conductors when at room temperature, with electrical resistance present inside the magnet. When the superconducting magnet is cooled to a temperature below 9K, the superconducting magnet enters a superconducting state, the internal resistance of the magnet is zero, high current of 600A or 2kA can be passed, and the heat generation amount is lower than 1W. In order to maintain the superconducting state of the superconducting magnet, the superconducting magnet is placed inside a cryostat, the outer surface of the cryostat is at room temperature, the contact part with the superconducting magnet is at a low temperature of less than 9K, and the cryostat can maintain the superconducting magnet to operate in a low-temperature environment for a long time.

In order to maintain the superconducting magnet at a temperature below 9K, good heat exchange equipment is required to establish heat exchange between the superconducting magnet and the cold source, and to cool the superconducting magnet, which may weigh several tons, in its superconducting state. The low-temperature heat pipe in the liquid helium temperature zone is used as efficient heat exchange equipment, the working temperature zone is 3K-5K, one end of the low-temperature heat pipe is connected with a cold source, the other end of the low-temperature heat pipe is connected with the cold conducting end of the superconducting magnet, the low temperature of the cold source can be quickly transferred to the superconducting magnet, heat generated by the superconducting magnet can also be quickly transferred to the cold source, and then the superconducting magnet is maintained in an environment with the temperature below 9K. The thermal performance of the liquid helium temperature zone low-temperature heat pipe is closely related to the material, the design structure and the magnetic field environment. At present, the working temperature area of the low-temperature heat pipe is above 80K, the thermal performance test is carried out by adopting liquid nitrogen, the test requirement below the extremely low temperature of 60K can not be met, the limit of the extremely low temperature is met, and the actual test is less.

Disclosure of Invention

The invention develops a thermal performance testing platform of a self-circulation low-temperature heat pipe, and aims to solve the problems that the long-time and extremely low-temperature testing requirement below 9K temperature cannot be met at present, and the tests with multiple sizes, different installation angles and current leads cannot be met. The invention can be used for the thermal performance test of the self-circulation low-temperature heat pipe in the extremely low-temperature environment and different installation angles for a long time at the temperature below 9K.

The technical scheme adopted by the invention is as follows:

a thermal performance test platform of a self-circulation low-temperature heat pipe is characterized by comprising a rotary bracket 1, a double-screen cryostat 7, a cold source and a current lead 15;

the rotating bracket 1 is connected with the double-screen cryostat 7 and is used for supporting the double-screen cryostat 7 and driving the double-screen cryostat 7 to rotate;

the double-screen cryostat 7 comprises a vacuum chamber 17, a normal temperature flange 8 is arranged at the top of the vacuum chamber 17, an external cold screen 9 is arranged inside the vacuum chamber 17, and a top flange 10 of the external cold screen 9 is arranged on the normal temperature flange 8 through a support piece 11;

the normal temperature end of the current lead 15 is arranged on the normal temperature flange 8, and the low temperature end of the current lead 15 is arranged on the top flange 10; the low-temperature end of the current lead 15 is connected with one end of the superconducting segment 16 through the top flange 10, and the other end of the superconducting segment 16 is used for being connected with a tested device;

the normal temperature end of the cold source is connected with the normal temperature flange 8, and the first-stage refrigeration part of the cold source is connected with the top flange 10 through a plurality of cold guide structures 20.

Further, an inner cold screen 12 is arranged inside the outer cold screen 9, a top flange 13 of the inner cold screen 12 is mounted on the top flange 10 through a support member 14, and the low-temperature end of the cold source is directly and hard connected with the top flange 13 of the inner cold screen 12; the other end of the superconducting segment 16 extends into the inner cold screen 12 through the top flange 13 of the inner cold screen 12 and is used for connecting with the tested device in the inner cold screen 12.

Further, a damping spring is arranged between the normal temperature end of the cold source and the normal temperature flange 8; and the primary refrigeration part of the cold source is in non-contact sealing connection with the top flange 10 through a connecting piece.

Furthermore, the rotating support comprises a driving motor, a gearbox, a support frame, a rotating shaft and a bearing fixed supporting leg; the bottom of support frame is equipped with a plurality ofly bearing fixed stay, the top of support frame be equipped with be used for with double screen cryostat connects the rotation axis, driving motor warp the gearbox with the rotation axis is connected.

Further, the normal temperature end of the current lead 15 is a copper cable, and the low temperature end of the current lead 15 is a high temperature superconducting cable.

Further, the low temperature end of the current lead 15 is connected with the superconducting segment 16 through solid ceramic aluminum nitride arranged on the top flange 10, so that the top flange 10 and the current lead are thermally connected and electrically insulated.

Further, the cold guide structure 20 is a multi-pair claw type cold guide structure; the cylinder body of the outer cold shield 9 is connected with the top flange 10 through a plurality of pairs of long soft body braided belts with high thermal conductivity.

Further, a plurality of heating sheets are arranged on the top flange 10 for adjusting the temperature range of the outer cold shield.

Further, the external cold shield 9 is a 40K aluminum shield; the internal cooling shield 12 is a 4K copper shield.

Further, the current lead 15 is wrapped with a plurality of layers of insulating glue.

The thermal performance test platform of the self-circulation low-temperature heat pipe comprises a rotary support, a double-screen cryostat, a 4K cold source and a current lead. The rotary bracket is used as a support and a fixing frame of the double-screen cryostat and is used as a 0-90-degree continuously-rotating platform of the double-screen cryostat; the double-screen cryostat is a heat insulation barrier and an operation space of the self-circulation low-temperature heat pipe; the 4K cold source provides and maintains the temperature below 9K for the self-circulation low-temperature heat pipe; the current lead provides current input for the superconducting magnet so as to meet the test requirements of the self-circulation liquid helium low-temperature heat pipe under the low-temperature environments with different sizes and operation conditions.

The rotary bracket is used as a double-screen cryostat supporting device, has the overall dimension height of 900mm, and the bottom occupied area of a rectangular area with the length and width of 600x400mm, and is provided with a motor-driven rotary mechanism which can realize continuous automatic rotation of 0-90 degrees. The whole size height of double-screen cryostat is 1200mm, and the shared region in bottom is the circular region that the diameter is 800mm, and the essential element from inside to outside has 4K copper screen, 40K aluminium screen and outer vacuum barrel top flange. The 4K cold source is a low-temperature refrigerator, can provide 4K temperature for a long time, mainly includes cold head, outside compressor, metal collapsible tube and cooling water set constitution. The current lead provides power for the superconducting magnet installed in the double-screen cryostat, and is composed of a normal-temperature copper cable and a high-temperature superconducting cable which are connected with a direct-current power supply through outer terminals.

The double-screen cryostat of the invention is provided with two cold screens and a vacuum chamber in the vacuum chamber, wherein the temperature of the inner cold screen is 4K, and the temperature of the outer cold screen is 40K.

The whole double-screen cryostat of the invention is connected with an external bracket through a rotary supporting point on a vacuum chamber cylinder.

The invention adopts a constant-speed servo motor as rotating power, realizes speed reduction through a reduction gearbox, realizes rotation of a vacuum chamber of the double-screen cryostat and slow angle change, and determines the rotating angle of the vacuum chamber of the double-screen cryostat through setting the rotating angle and a positioner.

The upper flange of the vacuum chamber is provided with a cold head interface, a self-circulation heat pipe gas injection interface, two current lead insulator interfaces, a temperature sensor measuring line interface, a vacuum safety valve, a vacuumizing interface and a pressure sensor leading-out interface; the vacuumizing interface is connected with an external vacuum pump set through a pipeline; the cold head is connected with an external compressor through a metal hose; the temperature sensor measuring line interface is connected with an external temperature tester through a signal line; the pressure sensor interface is connected with a device for measuring pressure through a pipeline.

The current lead wire and the current lead wire heat insulation sub-interface of the vacuum chamber are in a movable sealing structure.

The external cold shield and the cold shield flange are in flexible connection through the flexible copper strip.

The outer cold shield flange is in hard connection with the primary cold head of the low-temperature refrigerator through a copper plate.

The invention has the advantages that:

the invention adopts a split structure, is convenient to disassemble and assemble the heat pipe in the self-circulation liquid helium temperature region, and is convenient to disassemble the cold shield. The outer cold screen top flange is connected with a cold source through 8 pairs of claw type cold guide structures, the outer cold screen cylinder body is connected with the outer cold screen top flange through 8 pairs of long soft body high-thermal-conductivity braid (RRR 100), so that the cylinder body and the top flange of the outer cold screen are guaranteed to be at the same temperature, then the outer cold screen top flange is triangularly provided with heating sheets, the temperature range of the outer cold screen is adjusted, the outer cold screen can meet the temperature test of a 90K-40K cross-temperature area, meanwhile, the 8 pairs of long soft body high-thermal-conductivity braid is movably connected with the outer cold screen top flange, and the outer cold screen top flange is convenient to disassemble. The inner cooling screen adopts the overall square design, the material is a copper material with high heat conductivity and RRR (remote resistance ratio) of 100, the inner cooling screen top flange is directly and hard connected with a cold source, the inner cooling screen top flange is provided with a heater in a triangular arrangement form, the extremely low temperature environment adjustment of 4K-10K is realized, and the vacuum chamber measures and guarantees to be stabilized at 10 ℃ for a long time^-5Vacuum environment of Pa magnitude. The driving motor outputs power to the gearbox through the set rotating angle, the gearbox converts mechanical energy of the driving motor into rotating power to be output to the rotating shaft, the rotating shaft is connected with the double-screen cryostat, angular kinetic energy of the rotating shaft is output to the double-screen cryostat, and the double-screen cryostat is driven to rotate, so that tests of different angles and rotating speeds are realized. The vacuum chamber can realize the full-automatic stable rotation of 0-90 degrees, and the rotation of the cryostat to the set angle can be realized by setting any angle of 0-90 degrees on the programmed control program. In the rotating process of the thermostat, the rotating angle of the low-temperature thermostat can be displayed in real time through displacement detectors arranged on the bracket and the thermostat, and then the tested angle is fed back to a control program, so that the low-temperature thermostat rotates to a set angle at the uniform speed of 0.05m/s, and the measured piece is prevented from being influenced in the rotating process of the low-temperature thermostatMechanical stability. When the rotation angle of the cryostat exceeds the set angle plus 0.01 degrees, the control program sends out an instruction to disconnect the connection between the driving motor and the gearbox, and the automatic protection and self-locking of the over-angle are realized.

Drawings

FIG. 1 is an overall elevational view of the present invention;

FIG. 2 is a top view of the present invention;

FIG. 3 is a left side view of the present invention;

FIG. 4 is a cross-sectional view of the present invention;

fig. 5 is a view showing the structure of claw type cold conduction.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

As shown in fig. 1 to 5, a thermal performance testing platform of a self-circulation low-temperature heat pipe comprises a rotating support 1, wherein the rotating support 1 is respectively provided with a driving motor 2, a gearbox 3, a support frame 4, a rotating shaft 5 and a bearing fixed supporting leg 6, and is connected with a double-screen cryostat 7 through the rotating shaft 5 (the rotating shaft 5 is connected with the side wall of the double-screen cryostat 7, namely the rotating shaft 5 is divided into two sections, the left shaft does not rotate, and the right shaft rotates to drive the thermostat 7 to rotate). The top of double screen cryostat 7 is equipped with normal atmospheric temperature flange 8, and the inside of double screen cryostat 7 is equipped with outer cold screen 9, and it is 40K aluminium screen, and the top flange 10 of outer cold screen 9 passes through support piece 11 to be installed on normal atmospheric temperature flange 8, and the inside of outer cold screen 9 is equipped with interior cold screen 12, and it is 4K copper screen, and the top flange 13 of interior cold screen 12 passes through support piece 14 to be installed on the top flange 10 of outer cold screen 9. The normal temperature end part of the current lead 15 is arranged on the normal temperature flange 8, the low temperature end part of the current lead 15 is arranged on the top flange 10 of the outer cold screen 9, and in order to prevent current breakdown, 2 layers of insulating glue are wrapped on the normal temperature part and the low temperature part of the current lead 15. One end of the superconducting segment 16 of the current lead 15 is connected with the top flange 10 of the outer cold screen 9, and the other end is used for being connected with a tested device (such as a low-temperature heat pipe to be tested) positioned in the inner cold screen. The connection between the low-temperature end of the current lead 15 and the superconducting segment 16 and the top flange 10 is realized by solid ceramic aluminum nitride, so that the top flange 10 and the current lead are thermally connected and electrically insulated. The outer cylinder wall of the vacuum chamber 17 of the double-screen cryostat 7 is provided with a vacuum sealing valve 18 and a vacuum pumping port 19. The upper end of the claw type cold guide structure 20 is connected with the primary cold source, and the lower end is connected with the top flange 10 of the outer cold screen 9.

When equipment testing is only required to be carried out in a 40K-60K temperature area, the internal cooling screen 12, the top flange 13 and the supporting piece 14 can be removed, and the tested equipment is directly tested in the external cooling screen 9.

The driving motor 2 outputs power to the gearbox 3 through the set rotating angle, the gearbox 3 converts the mechanical energy of the driving motor 2 into rotating power to be output to the rotating shaft 5, the rotating shaft 5 is connected with the double-screen cryostat 7, the angular kinetic energy of the rotating shaft 5 is output to the double-screen cryostat 7, and the double-screen cryostat 7 is driven to rotate, so that the tests of different angles and rotating speeds are realized. The current lead 15 is composed of a normal temperature copper cable and a high temperature superconducting cable, and is connected with a direct current power supply by mounting the normal temperature end part of the current lead 15 on a normal temperature flange 8, so that external current is transmitted to the high temperature superconducting cable for current transmission, and full-automatic and stable rotation of 0-90 degrees is realized.

The vacuum chamber 17 of the dual-screen cryostat 7 provides a cool down and test insulating environment for the 40K aluminum screen 9 and the 4K copper screen 12, and the rotating rack 1 provides mechanical support for long duration cryogenic testing. The upper end and the lower end of a measured piece in the double-screen cryostat 7 are provided with a temperature detector, a pressure measuring device and a heating device.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.