Sealing performance test device and method for superconducting motor refrigerant transmission seal

Abstract

The application discloses a kind of sealing performance test device and method of superconducting motor refrigerant transmission seal, test device includes inner cavity component, outer cavity component and plugging piece, inner cavity component one end has first air vent, the other end has movable interface, the inner cavity component outer wall in movable interface one end is formed with inner diameter radial stop; Outer cavity component is coaxially arranged in inner cavity component, outer cavity component one end close to movable interface has second air vent, outer cavity component inner wall is formed with the outer diameter radial stop corresponding with inner diameter radial stop, the inner ring and outer ring of the seal to be tested are respectively sealed to be connected with inner diameter radial stop and outer diameter radial stop, the outer wall of outer cavity component located at the both sides of seal is formed with pressure measuring port and the outer wall close to the side of first air vent is formed with exhaust port;Plugging piece is detachably arranged at the movable interface.The application solves the technical problems that the existing superconducting motor refrigerant transmission sealing performance test device has long cooling time and complex debugging process.

Description

Technical Field

[0001] This invention relates to the field of superconducting motor technology, and specifically to a testing device and method for the sealing performance of a superconducting motor refrigerant transmission seal. Background Technology

[0002] In superconducting motors, the refrigerant transfer device serves as a transition between the stationary refrigeration unit and the rotor, transferring the refrigerant from the stationary refrigeration unit to the rotating rotor. The refrigerant transfer device must possess excellent sealing performance, high transfer efficiency, high pressure resistance, and low heat leakage. Its performance directly impacts the overall performance of the superconducting motor, making it a critical component. Therefore, to design and manufacture high-performance refrigerant transfer devices, a testing apparatus for accurately measuring the sealing performance of its sealing components is essential.

[0003] To measure its sealing performance, test devices for measuring leakage rate at low temperatures have been designed, such as the Chinese invention patent application "A device and method for measuring the transmission performance of refrigerant transport components for superconducting motors" published under publication number CN112649041A. However, the above-mentioned technology uses an indirect testing method with heating, which involves a relatively complex measurement and calculation process. It has shortcomings such as excessively long test cooling time, complex debugging process, and single measurement object, resulting in an excessively long design verification cycle and affecting the overall design progress of superconducting motors. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, this invention proposes a sealing performance testing device and method for refrigerant transmission seals in superconducting motors, thereby solving the technical problems of excessively long cooling time, complex debugging process, and low accuracy in existing superconducting motor refrigerant transmission sealing performance testing devices.

[0005] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a sealing performance testing device for a superconducting motor refrigerant transmission seal, comprising:

[0007] An inner cavity assembly has a first vent at one end and a movable interface at the other end, with an inner radial stop formed on the outer wall of the inner cavity assembly at the movable interface end.

[0008] An outer cavity assembly is coaxially disposed within the inner cavity assembly. The outer cavity assembly has a second vent at one end near the movable interface. The inner wall of the outer cavity assembly forms an outer radial stop corresponding to the inner radial stop. The inner ring and outer ring of the seal to be tested are respectively sealed and connected to the inner radial stop and the outer radial stop. The outer walls of the outer cavity assembly on both sides of the seal have pressure testing ports, and the outer wall near the first vent has an exhaust port.

[0009] A sealing element, which is detachably installed at the active interface.

[0010] In some embodiments, the inner cavity assembly includes an inner shaft and an inner shaft fixing member. The inner shaft is disposed in the outer cavity assembly and fixed to the outer cavity assembly by the inner shaft fixing member fixed to one end of the inner shaft. A first venting cavity is formed inside the inner shaft. The first vent and the movable interface are respectively opened at both ends of the first venting cavity. The inner radial stop is disposed on the outer wall of the end of the inner shaft where the movable interface is opened.

[0011] In some embodiments, the inner cavity assembly further includes an inner shaft connecting tube, one end of which is connected to the first vent, and the other end of which is connected to an external air supply device.

[0012] In some embodiments, the sealing element is bolted to the movable interface.

[0013] In some embodiments, the outer cavity assembly includes an outer shaft and an outer shaft fixing member. A second venting cavity is formed inside the outer shaft, and an inner shaft is disposed in the second venting cavity. The outer shaft fixing member is fixed to one end of the outer shaft. The outer shaft is coaxially connected to the inner shaft fixing member through the outer shaft fixing member. The second vent, the pressure measuring port, and the exhaust port are all opened on the outer shaft.

[0014] In some embodiments, the outer cavity assembly further includes an outer shaft connecting pipe, one end of which is connected to the second vent, and the other end of which is connected to an external air supply device.

[0015] In some embodiments, the seal includes a matching inner seal and an outer seal, the inner seal being interference-fitted with the inner cavity assembly via the inner radial stop, and the outer seal being interference-fitted with the outer cavity assembly via the outer radial stop.

[0016] In some embodiments, a differential pressure measuring instrument is further included, wherein two interfaces of the differential pressure measuring instrument are respectively connected to the two pressure measuring ports.

[0017] In some embodiments, a gas flow meter is further included, which is respectively disposed at the exhaust port and the first vent.

[0018] Secondly, the present invention provides a method for testing the sealing performance of a superconducting motor refrigerant transfer seal, which is implemented based on the sealing performance testing device for a superconducting motor refrigerant transfer seal provided in the first aspect of the present invention. The testing method includes a pressure drop test process and a leakage test process, wherein:

[0019] The pressure drop test process includes:

[0020] Install the sealing component at the active interface;

[0021] Normal temperature gas is introduced into the outer cavity assembly through the second vent.

[0022] The pressure drop performance of a seal is evaluated by measuring the pressure difference at two pressure gauges.

[0023] The leakage test process includes:

[0024] Remove the sealing component from the active interface and seal the two pressure test ports;

[0025] Normal temperature gas is introduced into the inner cavity assembly through the first vent;

[0026] The leakage performance of the seal is evaluated by measuring the gas flow rate through the first vent and the exhaust port.

[0027] Compared with existing technologies, the present invention provides a sealing performance testing device and method for a superconducting motor refrigerant transfer sealing component. This device can perform pressure drop tests on the sealing component under conditions where the interior of the internal cavity assembly is sealed with a sealing component, and leakage tests under conditions where the internal cavity assembly is opened by removing the sealing component and simultaneously sealing the pressure measuring port. This allows the testing device of the present invention to simultaneously perform both pressure drop and leakage tests through its ingenious structural design. It has the advantages of simple structure and ease of manufacturing; moreover, the testing process is simple and accurate, which can greatly shorten the design cycle and improve the design accuracy of superconducting motor refrigerant transfer devices, playing an important auxiliary role in the design and manufacturing of superconducting motors. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the experimental device described in this invention;

[0029] Figure 2 This is an exploded view of the experimental apparatus described in this invention;

[0030] Figure 3 This is a gas flow diagram of the test device described in this invention during a pressure drop test;

[0031] Figure 4 This is a gas flow diagram of the test device described in this invention during a leak test;

[0032] Figure 5 This is a flowchart of the test method described in this invention.

[0033] The annotations in the attached figures are explained as follows:

[0034] 100. Inner cavity assembly; 101. First vent; 102. Movable interface; 110. Inner shaft; 111. First vent cavity; 120. Inner shaft fixing piece; 130. Inner shaft connecting pipe.

[0035] 200, outer cavity assembly; 201, second vent; 202, pressure measuring port; 203, exhaust port; 210, outer shaft; 211, second vent cavity; 220, outer shaft fixing component; 230, outer shaft connecting pipe.

[0036] 300. Sealing components;

[0037] 400. Seal; 410. Inner seal; 420. Outer seal. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] To address the technical problems of existing testing devices for the sealing performance of refrigerant transfer in superconducting motors, such as excessively long cooling times, complex debugging processes, and low accuracy, this invention proposes a testing device and method for the sealing performance of refrigerant transfer seals in superconducting motors. This testing device can perform nitrogen (or air) pressure drop tests on the seals at room temperature. By reversing the air inlet and blocking or opening certain channels, nitrogen (or air) leakage tests on the seals at room temperature can be performed. Furthermore, the installation position of the seals is designed with axial and radial positioning, allowing for the disassembly and replacement of different seal combinations, and enabling the measurement of pressure drop and leakage of different seals.

[0040] Please see Figure 1 and Figure 2 As shown, the first aspect of the present invention provides a sealing performance testing device for a superconducting motor refrigerant transmission seal, comprising an inner cavity assembly 100, an outer cavity assembly 200, and a sealing member 300. One end of the inner cavity assembly 100 has a first vent 101, and the other end has a movable interface 102. An inner radial stop and an outer radial stop are respectively formed on the outer wall of the inner cavity assembly 100 at one end of the movable interface 102 and on the inner wall of the outer cavity assembly 200 at the corresponding position. The inner ring and outer ring of the sealing member 400 are respectively sealed to the inner radial stop and the outer radial stop. The end of the outer cavity assembly 200 near the movable interface 102 has a second vent 201. Pressure measuring ports 202 are formed on the outer walls of the outer cavity assembly 200 on both sides of the sealing member 400, and an exhaust port 203 is formed on the outer wall near the first vent 101. The sealing member 300 is detachably disposed at the movable interface 102.

[0041] In this invention, when the sealing member 300 seals the internal space of the inner cavity assembly 100, that is, when the sealing member 300 is installed in the movable interface 102, the sealing performance of the sealing member 400 can be obtained by introducing room temperature gas into the second vent 201 and measuring the pressure difference between the two pressure measuring ports 202. The larger the measured pressure difference value, the worse the sealing performance of the sealing member 400 is, and the more gas passes through the sealing member 400. After the pressure drop test is completed, the sealing member 300 is removed from the movable interface 102, and the two pressure measuring ports 202 are sealed at the same time. Then, gas is introduced into the inner cavity assembly 100 through the first vent 101. By measuring the gas flow rate of the first vent 101 and the exhaust port 203 and calculating the percentage of the gas flow rate at the exhaust port 203 to the gas flow rate at the first vent 101, the leakage rate of the sealing member 400 can be obtained, and the leakage performance of the sealing member 400 can be evaluated. As can be seen, the present invention can conduct two modes of testing with a single device, simplifying the testing process, greatly shortening the design cycle of the superconducting motor refrigerant transfer device and improving accuracy; moreover, the testing device of the present invention has a simple structure and is easy to process and manufacture, which plays an important auxiliary role in the design and manufacturing of superconducting motors.

[0042] It is understood that this invention uses room temperature gas measurement to test the sealing performance of the refrigerant transfer device, compares the test results with simulation results, and corrects the simulation method. Due to the similarity of gas flow characteristics, the same simulation method is also applicable at low temperatures. In the pressure drop test, this invention utilizes a detachable structure to compare and select the sealing component with better sealing performance. Subsequently, it switches to a leakage rate test to measure the leakage rate of the selected sealing component, compares it with the simulation results under different operating conditions, and corrects the simulation method. After obtaining an accurate simulation calculation method, this method is used to calculate the leakage rate of cryogenic helium in the refrigerant coupling device. Finally, the final solution is tested and verified in a cryogenic measurement device.

[0043] The following provides a detailed description of the components and working principle of the sealing performance testing device for the superconducting motor refrigerant transmission seal described in this invention.

[0044] In one embodiment, the inner cavity assembly 100 includes an inner shaft 110, an inner shaft fixing member 120, and an inner shaft connecting tube 130. The inner shaft 110 is disposed in the outer cavity assembly 200, specifically in the second vent chamber 211 of the outer shaft 210. The inner shaft fixing member 120 is disposed at one end of the inner shaft 110. After the inner shaft 110 is inserted into the second vent chamber 211 of the outer shaft 210, it is fixedly connected to the outer shaft fixing member 220 through the inner shaft fixing member 120. A first vent chamber 111 is formed inside the inner shaft 110. A first vent 101 and a movable interface 102 are respectively opened at both ends of the first vent chamber 111. An inner radial stop is disposed on the outer wall of the end of the inner shaft 110 where the movable interface 102 is located, for positioning the inner sealing member 410 of the sealing member 400. One end of the inner shaft connecting tube 130 is connected to the first vent 101, and the other end is connected to an external air supply device.

[0045] In one embodiment, the outer cavity assembly 200 includes an outer shaft 210, an outer shaft fixing member 220, and an outer shaft connecting pipe 230. A second vent chamber 211 is formed inside the outer shaft 210, and an inner shaft 110 is disposed within this second vent chamber 211. The outer shaft fixing member 220 is fixed to one end of the outer shaft 210. The outer shaft 210 is coaxially connected to the inner shaft fixing member 130 via the outer shaft fixing member 230. A second vent 201 is located at the end of the outer shaft 210 away from the outer shaft fixing member 220. Two pressure measuring ports 202 are located on the outer wall of the outer shaft 210, on the inner and outer sides of the seal 400, for measuring the gas pressure on the inner and outer sides of the seal 400. An exhaust port 203 is located on the outer wall of the outer shaft 210. One end of the outer shaft connecting pipe 230 is connected to the second vent 201, and the other end is connected to an external air supply device.

[0046] In one embodiment, the inner shaft fixing member 120 and the outer shaft fixing member 220 are mating flange structures.

[0047] In one embodiment, the sealing element 300 and the movable interface 102 are detachably connected by bolts.

[0048] In one embodiment, the test apparatus further includes a differential pressure measuring instrument and a gas flow meter. The two interfaces of the differential pressure measuring instrument are respectively connected to the two pressure measuring ports 202. The gas flow meter is respectively disposed at the exhaust port 203 and the first vent 101.

[0049] In one embodiment, the seal 400 includes a matching inner seal 410 and an outer seal 420, the inner seal 410 being press-fitted with the outer wall of the inner shaft 110 of the inner cavity assembly 100 via the inner radial stop, and the outer seal 420 being press-fitted with the inner wall of the outer periphery 210 of the outer cavity assembly 200 via the outer radial stop.

[0050] It should be noted that the inner seal 410 represents several sealing structures with the same inner diameter but different outer ring structures, and the outer seal 420 represents several sealing structures with the same outer diameter but different inner ring structures. The outer ring structures and inner ring structures of the inner seal 410 and outer seal 420 of the same seal 400 are compatible structures. There can be multiple such compatible structures. Therefore, the test device of the present invention can measure the sealing performance of seals 400 with different combinations of sealing structures. Compared with existing test devices, it has a wider range of applications.

[0051] The working principle of the experimental device provided by the present invention is as follows:

[0052] 1. Pressure drop test procedure:

[0053] like Figure 3 As shown, during the pressure drop test, the sealing component 300 is installed in the movable interface 102, and the pressure measuring port 202 and the exhaust port 203 are in the open state. The two ends of the differential pressure measuring instrument are connected to the two pressure measuring ports 202 respectively. Then, room temperature gas is introduced into the second vent chamber 211 through the second vent 201. Since the first vent chamber 111 is blocked by the sealing component 300, the gas flows to the sealing component 400 around the sealing component 300. At this time, the sealing performance of the sealing component 400 can be evaluated by measuring the pressure difference of the gas inside and outside the sealing component 400 through the differential pressure measuring instrument. The larger the pressure difference, the worse the sealing performance of the sealing component 400.

[0054] 2. Leakage test procedure:

[0055] like Figure 4 As shown, during the leakage test, the sealing component 300 is removed from the active interface 102, and the two pressure measuring ports 202 are blocked. Then, room temperature gas is introduced into the first vent chamber 111 through the first vent port 101. Since the sealing component 300 has been removed, the gas flows from the first vent chamber 111 to the second vent chamber 211. At this time, the total flow rate of the gas entering the first vent chamber 111 and the flow rate of the gas flowing out of the exhaust port 203 are measured by a gas flow meter. The percentage of the flow rate of the gas flowing out of the exhaust port 203 to the total flow rate of the gas in the first vent chamber 111 is calculated, which is the leakage rate of the sealing component 400. The larger this value is, the worse the leakage performance of the sealing component 400.

[0056] Secondly, such as Figure 5As shown, the present invention also provides a method for testing the sealing performance of a superconducting motor refrigerant transfer seal, which is implemented based on the sealing performance testing device for the superconducting motor refrigerant transfer seal described in the first aspect of the present invention. The testing method includes a pressure drop test process and a leakage test process, wherein...

[0057] The pressure drop test process includes:

[0058] Install the sealing component 300 at the movable interface 102;

[0059] Normal temperature gas is introduced into the outer cavity assembly 200 through the second vent 201;

[0060] The pressure drop performance of the seal is evaluated by measuring the pressure difference at the two pressure gauges 202.

[0061] The leakage test process includes:

[0062] Remove the sealing component 300 from the active interface 102 and seal the two pressure test ports 202;

[0063] Normal temperature gas is introduced into the inner cavity assembly 100 through the first vent 101;

[0064] The leakage performance of the seal is evaluated by measuring the gas flow rate through the first vent 101 and the exhaust port 203.

[0065] In summary, the sealing performance testing device and method for refrigerant transfer seals of superconducting motors provided by this invention, through ingenious structural design, enables a single device to simultaneously perform both pressure drop testing and leakage testing modes. It has the advantages of simple structure and ease of processing and manufacturing; moreover, the testing process is simple and accurate, which can greatly shorten the design cycle of superconducting motor refrigerant transfer devices and improve design accuracy, thus playing an important auxiliary role in the design and manufacturing of superconducting motors.

[0066] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A sealing performance testing device for a superconducting motor refrigerant transfer seal, characterized in that, include: An inner cavity assembly has a first vent at one end and a movable interface at the other end, with an inner radial stop formed on the outer wall of the inner cavity assembly at the movable interface end. An outer cavity assembly is coaxially disposed outside the inner cavity assembly. The outer cavity assembly has a second vent at one end near the movable interface. The inner wall of the outer cavity assembly forms an outer radial stop corresponding to the inner radial stop. The inner ring and outer ring of the seal to be tested are respectively sealed and connected to the inner radial stop and the outer radial stop. The outer wall of the outer cavity assembly forms a pressure measuring port and an exhaust port. The pressure measuring port is located on both sides of the seal, and the exhaust port is arranged near the first vent. A sealing element, which is detachably mounted at the movable interface; The differential pressure measuring instrument and the gas flow meter are respectively connected to the two pressure measuring ports through two interfaces of the differential pressure measuring instrument, and the gas flow meter is respectively installed at the exhaust port and the first vent.

2. The sealing performance testing device for the superconducting motor refrigerant transfer seal according to claim 1, characterized in that, The inner cavity assembly includes an inner shaft and an inner shaft fixing member. The inner shaft is disposed in the outer cavity assembly and is fixed to the outer cavity assembly by the inner shaft fixing member fixed to one end of the inner shaft. A first venting cavity is formed inside the inner shaft. The first vent and the movable interface are respectively opened at both ends of the first venting cavity. The inner radial stop is disposed on the outer wall of the end of the inner shaft where the movable interface is opened.

3. The sealing performance testing device for the superconducting motor refrigerant transfer seal according to claim 2, characterized in that, The inner cavity assembly also includes an inner shaft connecting tube, one end of which is connected to the first vent, and the other end of which is connected to an external air supply device.

4. The sealing performance testing device for the superconducting motor refrigerant transfer seal according to claim 3, characterized in that, The sealing component is bolted to the movable interface.

5. The sealing performance testing device for the superconducting motor refrigerant transmission seal according to claim 2, characterized in that, The outer cavity assembly includes an outer shaft and an outer shaft fixing member. A second venting cavity is formed inside the outer shaft, and the inner shaft is disposed in the second venting cavity. The outer shaft fixing member is fixed to one end of the outer shaft. The outer shaft is coaxially connected to the inner shaft fixing member through the outer shaft fixing member. The second vent, the pressure measuring port, and the exhaust port are all opened on the outer shaft.

6. The sealing performance testing device for the superconducting motor refrigerant transmission seal according to claim 5, characterized in that, The outer cavity assembly also includes an outer shaft connecting pipe, one end of which is connected to the second vent, and the other end of which is connected to an external air supply device.

7. The sealing performance testing device for the superconducting motor refrigerant transmission seal according to claim 1, characterized in that, The sealing element includes a matching inner sealing element and an outer sealing element. The inner sealing element is interference-fitted with the inner cavity assembly through the inner radial stop, and the outer sealing element is interference-fitted with the outer cavity assembly through the outer radial stop.

8. A method for testing the sealing performance of a superconducting motor refrigerant transfer seal, characterized in that, The sealing performance testing device for the superconducting motor refrigerant transfer seal as described in any one of claims 1-7 is used, and the testing method includes a pressure drop test process and a leakage test process, wherein... The pressure drop test process includes: Install the sealing component at the active interface; Normal temperature gas is introduced into the outer cavity assembly through the second vent. The pressure drop performance of a seal is evaluated by measuring the pressure difference at two pressure gauges. The leakage test process includes: Remove the sealing component from the active interface and seal the two pressure test ports; Normal temperature gas is introduced into the inner cavity assembly through the first vent; The leakage performance of the seal is evaluated by measuring the gas flow rate through the first vent and the exhaust port.

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