Vertical test platform, system and method for multi-temperature regions of liquid helium and superfluid helium

Abstract

The present invention relates to the technical field of accelerators, and provides a vertical test platform, system and method for multi-temperature regions of liquid helium and superfluid helium. The platform includes a vertical test distribution valve box with a valve box cold shield, a vertical test dewar with a dewar cold shield, a displacement pump group, a vacuum acquisition device, a cold shield inlet gas pipeline, a cold shield return gas pipeline, a supercritical helium inlet gas pipeline and a helium vapor return gas pipeline. The output of the cold shield inlet gas pipeline is communicated with the valve box cold shield and the dewar cold shield, and the output of the supercritical helium inlet gas pipeline is communicated with the vertical test dewar; the input of the cold shield return gas pipeline is communicated with the valve box cold shield and the dewar cold shield, and the input of the helium vapor return gas pipeline is communicated with the vertical test dewar; by setting cryogenic valves, pressure sensors and temperature sensors on the cold shield inlet gas pipeline, the cold shield return gas pipeline, the supercritical helium inlet gas pipeline and the helium vapor return gas pipeline, the performance parameters of the superconducting cavity at 4.5K and 2K temperature regions can be obtained, providing support for the design and manufacture of superconducting cavities related to superconducting accelerators.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerators, and in particular, to a vertical test platform, system and method for multi-temperature regions of liquid helium and superfluid helium. Background Art

[0002] With the development of large-scale superconducting accelerator technology, as a core device of particle accelerators, superconducting cavities need to be vertically tested to obtain the unloaded quality factor Q 0 and the accelerating field gradient E acc , so as to verify their design indicators, thereby being able to verify whether the current design meets the expected performance requirements, and also providing valuable data support for subsequent design and manufacturing.

[0003] In the prior art, there are many types of superconducting accelerator design cavities, and it is necessary to vertically test each superconducting cavity of different cavity types one by one. There are differences in the vertical test environment and tests for superconducting cavities of different cavity types. Therefore, for superconducting cavities of different cavity types, developing a vertical test platform to achieve multi-temperature regions, strong operation similarity, and highly reliable completion of vertical test experimental research is an important issue that the industry urgently needs to solve at present. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a vertical test platform, system and method for multi-temperature regions of liquid helium and superfluid helium, which can obtain the performance parameters of superconducting cavities at 4.5K and 2K temperature regions, and provide data support for the design, manufacture and processing of superconducting cavities related to superconducting accelerators.

[0005] The present invention provides a vertical test platform for multi-temperature regions of liquid helium and superfluid helium, including:

[0006] A vertical test distribution valve box, the vertical test distribution valve box having a valve box cold shield;

[0007] A vertical test dewar, the vertical test dewar having a dewar cold shield;

[0008] The pipeline assembly is arranged in the vertical test distribution valve box. The pipeline assembly includes a cold shield inlet pipeline, a cold shield return pipeline, a supercritical helium inlet pipeline, and a helium vapor return pipeline. Low-temperature valves, pressure sensors, and temperature sensors are provided on the cold shield inlet pipeline, the cold shield return pipeline, the supercritical helium inlet pipeline, and the helium vapor return pipeline. The input ends of the cold shield inlet pipeline and the supercritical helium inlet pipeline are both connected to the distribution and transmission system. The output end of the cold shield inlet pipeline is connected to the valve box cold shield and the Dewar cold shield. The output end of the supercritical helium inlet pipeline is connected to the inner cavity of the vertical test Dewar. The output ends of the cold shield return pipeline and the helium vapor return pipeline are both connected to the distribution and transmission system. The input end of the cold shield return pipeline is connected to the valve box cold shield and the Dewar cold shield. The input end of the helium vapor return pipeline is connected to the inner cavity of the vertical test Dewar. A negative pressure heat exchanger is provided on the supercritical helium inlet pipeline and the helium vapor return pipeline. A safety relief device is connected to the cold shield inlet pipeline and the cold shield return pipeline. A negative pressure protection and safety relief integrated device is connected to the helium vapor return pipeline;

[0009] A displacement pump set is connected to the cold shield return pipeline and the helium vapor return pipeline;

[0010] A vacuum acquisition device is connected to the vertical test distribution valve box and the vertical test Dewar.

[0011] According to a vertical test platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention, the supercritical helium inlet pipeline includes:

[0012] A first inlet pipeline. The input end of the first inlet pipeline is connected to the 4.5K supply gas pipeline of the distribution and transmission system. The output end of the first inlet pipeline is connected to the inner cavity of the vertical test Dewar. The negative pressure heat exchanger is arranged on the first inlet pipeline;

[0013] A second inlet pipeline. The input end of the second inlet pipeline is connected to the first inlet pipeline and is located on the corresponding inlet side of the negative pressure heat exchanger. The output end of the second inlet pipeline is connected to the inner cavity of the vertical test Dewar.

[0014] According to a vertical test platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention, the cold shield return pipeline has two output branches. One output branch is connected to the cold shield return gas pipeline of the distribution and transmission system through a low-temperature valve, and the other output branch is connected to the cooling return gas pipeline through a low-temperature valve;

[0015] The helium vapor return pipeline has two output branches. One output branch is connected to the 2K return pipeline of the distribution and transfer system through a cryogenic valve, and the other output branch is connected to the cooling return pipeline through a cryogenic valve. The cooling return pipeline is connected to the cooling return pipeline of the distribution and transfer system.

[0016] According to a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention, a first temperature mixing device is provided in the cold shield inlet pipeline, and the first temperature mixing device is connected to the rewarming gas supply pipeline of the distribution and transfer system through a normal temperature valve;

[0017] A second temperature mixing device is provided in the second inlet pipeline, and the second temperature mixing device is connected to the rewarming gas supply pipeline of the distribution and transfer system through a normal temperature valve.

[0018] According to a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention, the safety relief device includes a safety valve and a rupture disk.

[0019] According to a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention, the negative pressure protection and safety relief integrated device includes a negative pressure protection shell, a first-stage safety valve, a second-stage safety valve, and a rupture disk;

[0020] The negative pressure protection shell is respectively connected to the low-pressure branch of the distribution and transfer system, the displacement pump group, and the recovery and purification system; the first-stage safety valve is arranged on the negative pressure protection shell and connected to the helium vapor return pipeline, and the second-stage safety valve and the rupture disk are sequentially connected to the negative pressure protection shell, and the second-stage safety valve and the rupture disk are connected to the atmosphere.

[0021] According to a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention, a check valve is arranged between the first-stage safety valve and the helium vapor return pipeline.

[0022] According to a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention, the vertical test dewar is provided with a heater and / or a liquid level gauge.

[0023] The present invention also provides a vertical test system for multi-temperature regions of liquid helium and superfluid helium, including a helium gas storage system, a refrigerator system, a distribution and transfer system, a superfluid helium acquisition system, and the vertical test platform for multi-temperature regions of liquid helium and superfluid helium according to any one of the above.

[0024] The present invention also provides a method for using a vertical test system for multi-temperature regions of liquid helium and superfluid helium, including the following steps:

[0025] Step S1: Use a vacuum acquisition device to evacuate the interlayers of the vertical test distribution valve box and the vertical test dewar to bring the interlayers of the vertical test distribution valve box and the vertical test dewar to a preset vacuum state;

[0026] Step S2: Open the displacement pump set, the normal temperature valve connected to the displacement pump set, the low-temperature valves of the cold shield inlet pipeline, the cold shield return pipeline, the supercritical helium inlet pipeline, the helium vapor return pipeline, and the low-temperature valve connected to the cooling return pipeline to evacuate the distribution transmission system, the pipeline components, and the negative pressure protection and safety relief integrated device; when the value of the pressure sensor is lower than the first preset pressure value, close the displacement pump set;

[0027] Step S3: The refrigeration system fills the negative pressure protection shell of the pipeline components and the negative pressure protection and safety relief integrated device with 300K helium through the distribution transmission system; when the value of the pressure sensor reaches the second preset pressure value, stop filling with 300K helium and let it stand for the first predetermined time;

[0028] Step S4: Repeat Step S2 and Step S3 multiple times;

[0029] Step S5: Open the low-temperature valves of the cold shield inlet pipeline and the cold shield return pipeline, and the refrigeration system cools the valve box cold shield of the vertical test distribution valve box and the dewar cold shield of the vertical test dewar through the distribution transmission system;

[0030] Step S6: Open the low-temperature valves of the supercritical helium inlet pipeline and the helium vapor return pipeline, and the refrigeration system passes 4.5K liquid helium into the vertical test dewar through the 4.5K gas supply pipeline and the supercritical helium inlet pipeline of the distribution transmission system; the gas in the vertical test dewar enters the refrigeration system through the helium vapor return pipeline and the cooling return pipeline of the distribution transmission system;

[0031] Step S7: When the liquid volume of the 4.5K liquid helium in the vertical test dewar reaches the first required value, conduct a vertical test of the superconducting cavity at 4.5K temperature;

[0032] Step S8: Open the superfluid helium acquisition system, close the low-temperature valve of the output branch connecting the helium vapor return pipeline and the cooling return pipeline, open the low-temperature valve of the output branch connecting the helium vapor return pipeline and the 2K return pipeline, and obtain 2K superfluid helium in the vertical test dewar; when the liquid volume of the 4.5K liquid helium in the vertical test dewar reaches the second required value, conduct a vertical test of the superconducting cavity at 2K temperature.

[0033] The vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention can provide a stable low-temperature environment for a superconducting cavity at 4.5K and 2K temperature regions by arranging pipeline components in a vertical test distribution valve box, and low-temperature valves, pressure sensors and temperature sensors are arranged on the cold shield inlet pipeline, the cold shield return pipeline, the supercritical helium inlet pipeline and the helium vapor return pipeline. Furthermore, it can accurately obtain the vertical test of the superconducting cavity at 4.5K and 2K temperature regions, obtain the superconducting cavity performance parameters of the superconducting cavity, and provide data support for the design, manufacture and processing of superconducting cavities related to superconducting accelerators. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0035] Figure 1 is a schematic structural diagram of a vertical test system for multi-temperature regions of liquid helium and superfluid helium provided by the present invention.

[0036] Figure 2 is a schematic structural diagram of a vertical test platform for multi-temperature regions of liquid helium and superfluid helium provided by the present invention.

[0037] Figure 3 is a partial structural schematic diagram of a vertical test system for multi-temperature regions of liquid helium and superfluid helium provided by the present invention.

[0038] Figure 4 is Figure 2 a partial enlarged structural schematic diagram at position A in

[0039] Figure 5 is Figure 2 a partial enlarged structural schematic diagram at position B in

[0040] Figure 6 is Figure 2 a partial enlarged structural schematic diagram at position C in

[0041] Figure 7 is Figure 3 a partial enlarged structural schematic diagram at position D in

[0042] Reference numerals:

[0043] 100, vertical test platform;

[0044] 110, vertical test distribution valve box; 111, valve box vacuum cover; 112, valve box cold shield;

[0045] 120. Vertical test dewar; 121. Dewar inner wall; 122. Dewar outer wall; 123. Dewar cold shield;

[0046] 131. Cold shield inlet pipeline; 132. Cold shield return pipeline; 133. Supercritical helium inlet pipeline; 134. Helium vapor return pipeline; 135. Rewarming supply pipeline; 136. Cooling return pipeline;

[0047] 140. Negative pressure heat exchanger;

[0048] CV01. First cryogenic valve; CV02. Second cryogenic valve; CV03. Third cryogenic valve; CV04. Fourth cryogenic valve; CV05. Fifth cryogenic valve; CV06. Sixth cryogenic valve; CV07. Seventh cryogenic valve; CV08. Eighth cryogenic valve; CV09. Ninth cryogenic valve; CV10. Tenth cryogenic valve; CV11. Eleventh cryogenic valve; CV12. Twelfth cryogenic valve; CV13. Thirteenth cryogenic valve;

[0049] P1. First pressure sensor; P2. Second pressure sensor; P3. Third pressure sensor; P4. Fourth pressure sensor; P5. Fifth pressure sensor; P6. Sixth pressure sensor; P7. Seventh pressure sensor; P8. Eighth pressure sensor; P9. Ninth pressure sensor;

[0050] T1. First temperature sensor; T2. Second temperature sensor; T3. Third temperature sensor; T4. Fourth temperature sensor; T5. Fifth temperature sensor; T6. Sixth temperature sensor; T7. Seventh temperature sensor; T8. Eighth temperature sensor; T9. Ninth temperature sensor;

[0051] WV01. First normal temperature valve; WV02. Second normal temperature valve; WV03. Third normal temperature valve; WV04. Fourth normal temperature valve; WV05. Fifth normal temperature valve; WV06. Sixth normal temperature valve;

[0052] SV01. First safety valve; BP01. First bursting disc;

[0053] SV02-1. First-stage second safety valve; SV02-2. Second-stage second safety valve; BP02. Second bursting disc; SVG01. First negative pressure protection shell;

[0054] SV03-1. First-stage third safety valve; SV03-2. Second-stage third safety valve; BP03. Third bursting disc; SVG02. Second negative pressure protection shell;

[0055] SV04. Fourth safety valve; BP04. Fourth bursting disc;

[0056] Mix1, the first temperature mixing device; Mix2, the second temperature mixing device; VN01, the first one-way valve; VN02, the second one-way valve; VN03, the third one-way valve; PV01, the switch valve;

[0057] VS01, the first vacuum silicon; Pump3, the displacement pump unit; BV01, the first gate valve; BV02, the second gate valve; Pump1, the first vacuum pump unit; Pump2, the second vacuum pump unit; VS02, the second vacuum silicon; HT01, the fluid contact type DC power heater; HT02, the solid contact type DC power heater; LT01, the 4.5 K liquid helium level gauge; LT02, the 2 K superfluid helium level gauge;

[0058] VT01, the first sensor; VT02, the second sensor;

[0059] 200, the distribution and transfer system; 210, the multi-channel transfer pipeline; 211, the cold shield gas supply pipeline; 212, the cold shield gas return pipeline; 213, the 4.5K gas supply pipeline; 214, the 2K gas return pipeline; 220, the normal temperature pipeline; 221, the cooling gas return pipeline; 222, the rewarming gas supply pipeline; 230, the low-pressure branch;

[0060] 300, the helium storage system;

[0061] 400, the refrigerator system; 410, the compressor; 420, the oil removal and drying component; 430, the refrigerator cold box;

[0062] 500, the superfluid helium acquisition system; 510, the 2K gas heater; 520, the superfluid helium decompression and cooling pump unit;

[0063] 600, the recovery and purification system. Detailed implementation manners

[0064] The following further describes in detail the implementation manners of the present invention in conjunction with the accompanying drawings and embodiments. The following embodiments are used to illustrate the present invention, but cannot be used to limit the scope of the present invention.

[0065] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0066] In the description of the embodiments of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0067] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature has a lower horizontal height than the second feature.

[0068] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0069] An embodiment of the first aspect of the present invention provides a vertical test platform for multi-temperature zones of liquid helium and superfluid helium, as Figure 1 and Figure 2 shown. The vertical test platform includes a vertical test distribution valve box 110, a vertical test dewar 120, a pipeline assembly, a displacement pump group Pump3, and a vacuum acquisition device.

[0070] As Figures 4 to 6As shown in the figure, the vertical test distribution valve box 110 has a valve box cold shield 112; the vertical test dewar 120 has a dewar cold shield 123; the pipeline assembly is arranged in the vertical test distribution valve box 110, and the pipeline assembly includes a cold shield inlet pipeline 131, a cold shield return pipeline 132, a supercritical helium inlet pipeline 133 and a helium vapor return pipeline 134. Low-temperature valves, pressure sensors and temperature sensors are arranged on the cold shield inlet pipeline 131, the cold shield return pipeline 132, the supercritical helium inlet pipeline 133 and the helium vapor return pipeline 134. The input ends of the cold shield inlet pipeline 131 and the supercritical helium inlet pipeline 133 are both connected to the distribution and transmission system 200. The output end of the cold shield inlet pipeline 131 is connected to the valve box cold shield 112 and the dewar cold shield 123. The output end of the supercritical helium inlet pipeline 133 is connected to the inner cavity of the vertical test dewar 120; the output ends of the cold shield return pipeline 132 and the helium vapor return pipeline 134 are both connected to the distribution and transmission system 200. The input end of the cold shield return pipeline 132 is connected to the valve box cold shield 112 and the dewar cold shield 123. The input end of the helium vapor return pipeline 134 is connected to the inner cavity of the vertical test dewar 120; a negative pressure heat exchanger 140 is arranged on the supercritical helium inlet pipeline 133 and the helium vapor return pipeline 134; safety relief devices are connected to the cold shield inlet pipeline 131 and the cold shield return pipeline 132, and a negative pressure protection and safety relief integrated device is connected to the helium vapor return pipeline 134. The negative pressure protection and safety relief integrated device is located outside the vertical test distribution valve box 110; the replacement pump group Pump3 is connected to the cold shield return pipeline 132 and the helium vapor return pipeline 134; the vacuum acquisition device is connected to the vertical test distribution valve box 110 and the vertical test dewar 120. It should be noted here that the low temperature in the low-temperature valve is 2 - 300K.

[0071] The vertical test platform for liquid helium and superfluid helium multi-temperature zones provided by the embodiment of the present invention can provide a stable low-temperature environment for the superconducting cavity in the 4.5K and 2K temperature zones according to the design requirements of the superconducting cavity by arranging a pipeline assembly in the vertical test distribution valve box 110, and low-temperature valves, pressure sensors and temperature sensors are arranged on the cold shield inlet pipeline 131, the cold shield return pipeline 132, the supercritical helium inlet pipeline 133 and the helium vapor return pipeline 134. Furthermore, the vertical test of the superconducting cavity in the 4.5K and 2K temperature zones can be accurately obtained, and the superconducting cavity performance parameters of the superconducting cavity can be obtained, providing data support for the design, manufacture and processing of superconducting cavities related to superconducting accelerators.

[0072] In an embodiment of the present invention, the vacuum acquisition device includes a vertical test distribution valve box vacuum acquisition device and a vertical test dewar vacuum acquisition device. The vertical test distribution valve box vacuum acquisition device is connected to the vertical test distribution valve box 110, and the vertical test dewar vacuum acquisition device is connected to the vertical test dewar 120.

[0073] Specifically, such asFigure 5 As shown, the vertical test distribution valve box vacuum acquisition device includes a first gate valve BV01 connected to the top of the vertical test distribution valve box 110, and a first vacuum pump group Pump1 located on the ground foundation. The first gate valve BV01 is flange-connected to the first vacuum pump group Pump1. The first vacuum pump group Pump1 includes a primary mechanical pump and a secondary molecular pump.

[0074] As Figure 6 shown, the vertical test dewar vacuum acquisition device includes a second gate valve BV02 connected to the top cover plate of the vertical test dewar 120, and a second vacuum pump group Pump2 located on the bottom foundation. The second gate valve BV02 is flange-connected to the second vacuum pump group Pump2. The second vacuum pump group Pump2 includes a primary mechanical pump and a secondary molecular pump.

[0075] In an embodiment of the present invention, as Figure 5 shown, the vertical test distribution valve box 110 has a double-layer structure, specifically including a valve box vacuum cover 111 and a valve box cold shield 112 disposed within the valve box vacuum cover 111. The valve box cold shield 112 is used to reduce the radiative heat leakage of the internal cold fluid to the ambient temperature; a valve box vacuum interlayer is formed between the valve box vacuum cover 111 and the valve box cold shield 112, and the vertical test distribution valve box vacuum acquisition device is used to evacuate the valve box vacuum interlayer.

[0076] The valve box vacuum interlayer is provided with a first vacuum gauge VS01, which is electrically connected to a vacuum monitor. The first vacuum gauge VS01 is used to detect the vacuum state of the internal interlayer of the vertical test distribution valve box 110 (i.e., the valve box vacuum interlayer).

[0077] Furthermore, an eighth temperature sensor T8 is arranged on the valve box cold shield 112, and the eighth temperature sensor T8 is used to judge the cooling state of the valve box cold shield 112; preferably, the number of the eighth temperature sensors T8 can be multiple. In this embodiment, the valve box vacuum cover 111 and the valve box cold shield 112 have a hexahedron structure. The valve box vacuum cover 111 has six panels, and the valve box cold shield 112 has six cold shield surfaces that cooperate with the six panels. The number of the eighth temperature sensors T8 is six, which are respectively arranged on the six cold shield surfaces.

[0078] In an embodiment of the present invention, as Figure 6As shown, the vertical test dewar 120 includes a dewar inner wall 121 and a dewar outer wall 122. A dewar vacuum interlayer is formed between the dewar inner wall 121 and the dewar outer wall 122. A dewar cold shield 123 is arranged in the dewar vacuum interlayer. The dewar cold shield 123 is used to reduce the radiative heat leakage of the internal cold fluid to the ambient temperature; the vertical test dewar vacuum acquisition device is used to evacuate the dewar vacuum interlayer. The dewar vacuum interlayer is provided with a second vacuum silicon VS02, and the second vacuum silicon VS02 is electrically connected to a vacuum monitor. The second vacuum silicon VS02 is used to detect the vacuum state of the internal interlayer of the vertical test dewar 120.

[0079] Further, the vertical test dewar 120 is provided with a liquid level gauge; specifically, the dewar inner wall 121 is arranged at the side and bottom of the dewar outer wall 122, so that an inner container is formed between the top of the dewar inner wall 121 and the dewar outer wall 122. At a position close to the inner wall of the inner container of the vertical test dewar 120, a 4.5 K liquid helium level gauge LT01 and a 2 K superfluid helium level gauge LT02 are arranged. The liquid level gauges are vertically inserted into the inner container of the vertical test dewar 120 and are used to collect the liquid levels of 4.5 K liquid helium and 2 K superfluid helium, and maintain the designed highest accuracy in their respective applicable temperature ranges.

[0080] The vertical test dewar 120 is also provided with a VT sensor to obtain the unloaded quality factor Q 0 and the accelerating field gradient E acc through the measurement data of the VT sensor; in this embodiment, the VT sensor includes a first sensor VT01 and a second sensor VT02 arranged on the top cover of the vertical test dewar 120.

[0081] Further, an opening is provided at the top of the vertical test dewar 120. After being welded to the pressure lead-out pipe, the top cover of the vertical test dewar 120 is connected to a high-precision positive pressure sensor and a high-precision negative pressure sensor to collect the internal pressure of the vertical test dewar 120 according to different pressure ranges.

[0082] In an embodiment of the present invention, the vertical test dewar 120 is provided with a heater; optionally, the inner container of the vertical test dewar 120 is provided with a fluid-contact DC power heater HT01; further, a solid-contact DC power heater HT02 is arranged on the dewar inner wall 121.

[0083] Optionally, a ninth temperature sensor T9 is arranged in the vertical test dewar 120 to judge the temperature data in the vertical test dewar 120; preferably, a plurality of ninth temperature sensors T9 are arranged along the height direction of the dewar inner wall 121. In this embodiment, the ninth temperature sensor T9 is arranged on the dewar inner wall 121 and is close to the solid-contact DC power heater HT02.

[0084] In an embodiment of the present invention, asFigure 1 , Figure 3 , Figure 5 and Figure 7 As shown in Figure 1 , Figure 3 , Figure 5 and Figure 7 , the input end of the cold shield inlet pipeline 131 is connected to the cold shield supply pipeline 211 of the distribution and transmission system 200, the output end of the cold shield inlet pipeline 131 is connected to the Dewar cold shield 123, the cold shield inlet pipeline 131 is connected to the valve box cold shield 112, and an eighth cryogenic valve CV08, a sixth pressure sensor P6 and a fifth temperature sensor T5 are arranged on the cold shield inlet pipeline 131. Among them, the eighth cryogenic valve CV08, the sixth pressure sensor P6 and the fifth temperature sensor T5 are arranged in sequence along the flow direction of the helium medium; the sixth pressure sensor P6 is a high-precision positive pressure sensor, the fifth temperature sensor T5 is a high-precision temperature sensor, and the high-precision temperature sensor has two sensors, one for standby and one for use.

[0085] The input end of the cold shield return pipeline 132 is connected to the Dewar cold shield 123, the output end of the cold shield return pipeline 132 is connected to the cold shield return pipeline 212 of the distribution and transmission system 200, the cold shield return pipeline 132 is connected to the valve box cold shield 112, and a thirteenth cryogenic valve CV13, a fifth pressure sensor P5 and a sixth temperature sensor T6 are arranged on the cold shield return pipeline 132; among them, the fifth pressure sensor P5, the sixth temperature sensor T6 and the thirteenth cryogenic valve CV13 are arranged in sequence along the flow direction of the helium medium, the fifth pressure sensor P5 is a high-precision positive pressure sensor, the sixth temperature sensor T6 is a high-precision temperature sensor, and the high-precision temperature sensor has two sensors, one for standby and one for use.

[0086] It can be understood that the vertical test distribution valve box 110 sends about 50 K helium gas from the refrigerator system 400 into the valve box cold shield 112 and the Dewar cold shield 123 through the eighth cryogenic valve CV08. After the return gas cooled by the valve box cold shield 112 and the Dewar cold shield 123 passes through the thirteenth cryogenic valve CV13, it returns to the refrigerator system 400 to cool down the valve box cold shield 112 and the Dewar cold shield 123.

[0087] In an embodiment of the present invention, the supercritical helium inlet pipeline 133 includes a first inlet pipeline and a second inlet pipeline; the input end of the first inlet pipeline is connected to the 4.5K supply pipeline 213 of the distribution and transmission system 200, the output end of the first inlet pipeline is connected to the inner cavity of the vertical test Dewar 120, the input end of the second inlet pipeline is connected to the first inlet pipeline and is located on the corresponding inlet side of the negative pressure heat exchanger 140, and the output end of the second inlet pipeline is connected to the inner cavity of the vertical test Dewar 120.

[0088] Specifically, a third pressure sensor P3, a third temperature sensor T3, a fourth temperature sensor T4, a fourth pressure sensor P4, and a sixth cryogenic valve CV06 are provided on the first intake pipeline. The third pressure sensor P3, the third temperature sensor T3, the fourth temperature sensor T4, the fourth pressure sensor P4, and the sixth cryogenic valve CV06 are arranged in sequence along the flow direction of the helium medium. The negative pressure heat exchanger 140 is connected between the third temperature sensor T3 and the fourth temperature sensor T4. The input end of the second intake pipeline is connected between the third pressure sensor P3 and the third temperature sensor T3. A seventh cryogenic valve CV07, a seventh pressure sensor P7, and a seventh temperature sensor T7 are provided on the second intake pipeline. The seventh cryogenic valve CV07, the seventh pressure sensor P7, and the seventh temperature sensor T7 are arranged in sequence along the flow direction of the helium medium.

[0089] It can be understood that the supercritical helium gas from the refrigerator system at 4.5K @ 3.5 bar enters the vertical test distribution valve box 110 through the input end of the first intake pipeline and then is divided into two branches to enter the vertical test dewar 120. One of the branches does not pass through the negative pressure heat exchanger 140 and directly flows into the vertical test dewar 120 after passing through the seventh cryogenic valve CV07. The other branch flows through the negative pressure heat exchanger 140 and then flows into the vertical test dewar 120 after passing through the sixth cryogenic valve CV06. It should be noted that in the 2K mode, the negative pressure heat exchanger 140 cooperates with the sixth cryogenic valve CV06 and the superfluid helium acquisition system to complete throttling and pressure reduction.

[0090] In an embodiment of the present invention, a first temperature mixer Mix1 is provided on the cold shield intake pipeline 131. The first temperature mixer Mix1 is located between the eighth cryogenic valve CV08 and the sixth pressure sensor P6. The first temperature mixer Mix1 is communicated with the rewarming gas supply pipeline 222 of the distribution and transmission system 200 through the rewarming gas supply pipeline 135. A fifth normal temperature valve WV05 is provided on the rewarming gas supply pipeline 135. A second temperature mixer Mix2 is provided on the second intake pipeline. The second temperature mixer Mix2 is arranged between the seventh cryogenic valve CV07 and the seventh pressure sensor P7. The second temperature mixer Mix2 is communicated with the rewarming gas supply pipeline 135 through the sixth normal temperature valve WV06. Among them, the sixth normal temperature valve WV06 and the fifth normal temperature valve WV05 are in parallel.

[0091] It can be understood that the high-pressure gas from the refrigeration system 400 is transmitted through the rewarming supply gas pipeline 222, enters the first mixing temperature device Mix1 through the fifth normal-temperature valve WV05, mixes with the helium gas from the eighth low-temperature valve CV08, and then enters the dewar cold shield 123 of the vertical test dewar 120. The high-pressure gas from the refrigeration system 400 enters the second mixing temperature device Mix2 after passing through the sixth normal-temperature valve WV06, mixes with the incoming helium gas from the seventh low-temperature valve CV07, and then enters the vertical test dewar 120. Among them, a ninth pressure sensor P9 is provided on the rewarming supply gas pipeline 135, and the ninth pressure sensor P9 is a high-precision positive pressure sensor. Preferably, a third one-way valve VN03 is provided between the sixth normal-temperature valve WV06 and the second mixing temperature device Mix2, and the third one-way valve VN03 can effectively eliminate the measurement influence of the 4.5K thermoacoustic oscillation on the seventh pressure sensor P7.

[0092] Furthermore, a first pressure sensor P1, a first temperature sensor T1, a second temperature sensor T2, a second pressure sensor P2, and a ninth low-temperature valve CV09 are provided on the helium vapor return pipeline 134, and the ninth low-temperature valve CV09, the second pressure sensor P2, the second temperature sensor T2, the first temperature sensor T1, and the first pressure sensor P1 are arranged in sequence along the flowing direction of the helium medium.

[0093] In an embodiment of the present invention, the negative-pressure heat exchanger 140 is located inside the vertical test distribution valve box 110. The first input port and the first output port of the negative-pressure heat exchanger 140 are connected in series to the supercritical helium inlet pipeline 133, and the second input port and the second output port of the negative-pressure heat exchanger 140 are connected in series to the helium vapor return pipeline 134. Specifically, the first input port and the first output port of the negative-pressure heat exchanger 140 are connected in series between the third temperature sensor T3 and the fourth temperature sensor T4, and the second input port and the second output port of the negative-pressure heat exchanger 140 are connected in series between the second temperature sensor T2 and the first temperature sensor T1.

[0094] Furthermore, high-precision pressure sensors and high-precision temperature sensors are provided on both the input side and the output side of the two circuits of the negative-pressure heat exchanger 140. Preferably, the high-precision pressure sensors are high-precision positive pressure sensors and high-precision negative pressure sensors, and the high-precision temperature sensors are one for standby and one for use.

[0095] Specifically, the first temperature sensor T1, the second temperature sensor T2, the third temperature sensor T3, the fourth temperature sensor T4, and the seventh temperature sensor T7 are all high-precision temperature sensors and one for standby and one for use; the first pressure sensor P1 and the second pressure sensor P2 are both high-precision positive pressure sensors and high-precision negative pressure sensors; the third pressure sensor P3, the fourth pressure sensor P4, and the seventh pressure sensor P7 are all high-precision positive pressure sensors.

[0096] In an embodiment of the present invention, the helium vapor return pipeline 134 has two output branches. One output branch is communicated with the cooling return pipeline 221 of the distribution and transmission system 200 through the eleventh cryogenic valve CV11, and the other output branch is communicated with the 2K return pipeline 214 of the distribution and transmission system 200 through the tenth cryogenic valve CV10.

[0097] Furthermore, the cold shield return pipeline 132 is provided with a thirteenth cryogenic valve CV13. The cold shield return pipeline 132 on the inlet side of the thirteenth cryogenic valve CV13 is communicated with the cooling return pipeline 221 of the distribution and transmission system 200 through the twelfth cryogenic valve CV12.

[0098] It can be understood that the cold shield return pipeline 132 also has two output branches. One output branch is communicated with the cooling return pipeline 221 of the distribution and transmission system 200 through the twelfth cryogenic valve CV12, and the other output branch is communicated with the cold shield return pipeline 212 of the distribution and transmission system 200 through the thirteenth cryogenic valve CV13.

[0099] Optionally, the output pipelines of the eleventh cryogenic valve CV11 and the twelfth cryogenic valve CV12 are connected within the vertical test distribution valve box 110 and are communicated with the cooling return pipeline 221 of the distribution and transmission system 200 through the cooling return pipeline 136. Preferably, an eighth pressure sensor P8 located within the vertical test distribution valve box 110 is provided on the cooling return pipeline 136; the eighth pressure sensor P8 is a high-precision positive pressure sensor.

[0100] It can be understood that the thirteenth cryogenic valve CV13 and the twelfth cryogenic valve CV12 are in parallel, the twelfth cryogenic valve CV12 and the eleventh cryogenic valve CV11 are in parallel, and the eleventh cryogenic valve CV11 and the tenth cryogenic valve CV10 are in parallel, which can form all the return circuits for different working conditions, so as to realize the vertical test of the superconducting cavity at different working conditions, in the 4.5K and 2K temperature regions; the saturated helium gas at 4.5K or 2K in the vertical test dewar 120 returns to the refrigerator system 400 after passing through the eleventh cryogenic valve CV11 or the tenth cryogenic valve CV10.

[0101] In this embodiment, the sixth cryogenic valve CV06 to the thirteenth cryogenic valve CV13 are all pneumatic valves. Among them, the sixth cryogenic valve CV06 and the seventh cryogenic valve CV07 are pneumatic Joule-Thomson throttle valves (J-T valves), and the eighth cryogenic valve CV08 to the thirteenth cryogenic valve CV13 are all pneumatic regulating valves.

[0102] In an embodiment of the present invention, the safety relief device includes a protection pipeline and a safety valve and a rupture disc provided on the protection pipeline.

[0103] Specifically, a first safety relief device is connected to the cold screen return gas pipeline 132. The first safety relief device includes a first connection pipeline, a first safety valve SV01 and a first rupture disc BP01 provided on the first connection pipeline. The input end of the first connection pipeline is communicated with the cold screen return gas pipeline 132 and is located between the fifth pressure sensor P5 and the sixth temperature sensor T6. The output end of the first connection pipeline is communicated with the recovery and purification system 600. The first safety valve SV01 and the first rupture disc BP01 are located outside the vertical test distribution valve box 110. Among them, the first safety valve SV01 is connected to the recovery and purification system 600, and the first rupture disc BP01 is connected to the atmosphere.

[0104] A second safety relief device is connected to the cold screen inlet gas pipeline 131. The second safety relief device includes a fourth connection pipeline, a fourth safety valve SV04 and a fourth rupture disc BP04 provided on the fourth connection pipeline. The input end of the fourth connection pipeline is communicated with the cold screen inlet gas pipeline 131 and is located on the inlet side of the eighth low-temperature valve CV08. The output end of the fourth connection pipeline is communicated with the recovery and purification system 600. The fourth safety valve SV04 and the fourth rupture disc BP04 are located outside the vertical test distribution valve box 110. Among them, the fourth safety valve SV04 is connected to the recovery and purification system 600, and the fourth rupture disc BP04 is connected to the atmosphere.

[0105] In an embodiment of the present invention, the negative pressure protection and safety relief integrated device includes a negative pressure protection shell, a first-stage safety valve, a second-stage safety valve and a rupture disc. The negative pressure protection shell is communicated with the low-pressure branch of the distribution and transmission system, the displacement pump group and the recovery and purification system respectively. The first-stage safety valve is arranged on the negative pressure protection shell and is connected to the helium vapor return gas pipeline. The second-stage safety valve and the rupture disc are sequentially communicated with the negative pressure protection shell. Among them, both the second-stage safety valve and the rupture disc are communicated with the atmosphere. It should be noted here that the low pressure in the low-pressure branch is 1.05 - 1.3 bar.

[0106] Optionally, two negative pressure protection and safety relief integrated devices are connected to the helium vapor return gas pipeline 134, namely a first negative pressure protection and safety relief integrated device and a second negative pressure protection and safety relief integrated device. The first negative pressure protection and safety relief integrated device and the second negative pressure protection and safety relief integrated device are respectively connected to both sides of the negative pressure heat exchanger 140.

[0107] The first negative pressure protection and safety relief integrated device includes a second connection pipeline, a first negative pressure protection shell SVG01, a first-stage second safety valve SV02-1 (i.e., the first-stage safety valve), a second-stage second safety valve SV02-2 (i.e., the second-stage safety valve), and a second rupture disc BP02. The input end of the second connection pipeline is connected to the helium vapor return pipeline 134 and is located on the inlet side of the ninth cryogenic valve CV09. The output end of the second connection pipeline is connected to the first-stage second safety valve SV02-1, and the first-stage second safety valve SV02-1 is integrated within the first negative pressure protection shell SVG01. The first negative pressure protection shell SVG01 communicates with the recovery and purification system 600. The replacement gas outlet of the first negative pressure protection shell SVG01 is connected to the replacement pump set Pump3 through the fourth normal temperature valve WV04. The inlet of the first negative pressure protection shell SVG01 communicates with the low-pressure branch 230 of the distribution and transmission system 200. The exhaust port of the first negative pressure protection shell SVG01 is connected to the second-stage second safety valve SV02-2 and the second rupture disc BP02 arranged in sequence, and the second-stage second safety valve SV02-2 and the second rupture disc BP02 communicate with the atmosphere.

[0108] The second negative pressure protection and safety relief integrated device includes a third connection pipeline, a second negative pressure protection shell SVG02, a first-stage third safety valve SV03-1 (i.e., the first-stage safety valve), a second-stage third safety valve SV03-2 (i.e., the second-stage safety valve), and a third rupture disc BP03. The input end of the third connection pipeline is connected between the tenth cryogenic valve CV10 and the first pressure sensor P1. The output end of the third connection pipeline is connected to the first-stage third safety valve SV03-1, and the first-stage third safety valve SV03-1 is located within the second negative pressure protection shell SVG02. The second negative pressure protection shell SVG02 communicates with the recovery and purification system 600. The replacement gas outlet of the second negative pressure protection shell SVG02 is connected to the replacement pump set Pump3 through the third normal temperature valve WV03. The inlet of the second negative pressure protection shell SVG02 communicates with the low-pressure branch 230 of the distribution and transmission system 200. The exhaust port of the second negative pressure protection shell SVG02 is connected to the second-stage third safety valve SV03-2 and the third rupture disc BP03 arranged in sequence, and the second-stage third safety valve SV03-2 and the third rupture disc BP03 communicate with the atmosphere.

[0109] Furthermore, a check valve is provided between the first-stage safety valve and the helium vapor return pipeline 134.

[0110] Specifically, a first check valve VN01 located within the vertical test distribution valve box 110 is provided at the input end of the second connection pipeline, and a second check valve VN02 located within the vertical test distribution valve box 110 is provided at the input end of the third connection pipeline; the first check valve VN01 and the second check valve VN02 can prevent thermoacoustic oscillations below the 4.5K temperature range and avoid the operation of the safety valve and the rupture disc due to incorrect pressure fluctuations.

[0111] Optionally, the third connection pipeline is connected to the displacement pump group Pump3 through the first normal-temperature valve WV01, and the first connection pipeline is connected to the displacement pump group Pump3 through the second normal-temperature valve WV02. It should be noted that the first normal-temperature valve WV01, the second normal-temperature valve WV02, the third normal-temperature valve WV03, and the fourth normal-temperature valve WV04 are all connected to the displacement pump group Pump3 and are used to evacuate the gas environment inside the displacement pipeline.

[0112] In this embodiment, the first normal-temperature valve WV01 to the sixth normal-temperature valve WV06 are all normal-temperature pneumatic valves.

[0113] As Figures 1 to 7 shown, an embodiment of the present invention further provides a vertical test system for multi-temperature zones of liquid helium and superfluid helium. The test system includes a helium storage system 300, a refrigerator system 400, a distribution and transmission system 200, a superfluid helium acquisition system 500, and the vertical test platform 100 for multi-temperature zones of liquid helium and superfluid helium according to any one of the above embodiments.

[0114] Optionally, the test system further includes a recovery and purification system 600. The helium storage system 300 is communicated with the refrigerator system 400. The refrigerator system 400 is communicated with the vertical test platform 100 through the distribution and transmission system 200. The vertical test platform 100 is communicated with the superfluid helium acquisition system 500 through the distribution and transmission system 200. The superfluid helium acquisition system 500 is communicated with the input of the refrigerator system 400. The vertical test platform 100 is communicated with the refrigerator system 400 through the recovery and purification system 600.

[0115] In this embodiment, the helium storage system 300 is a high-pressure gas storage tank operating in parallel. The helium storage system 300 contains the necessary helium for the operation of the entire system. For example, the helium storage system 300 includes 8 high-purity helium storage tanks, and the inside thereof has high-pressure high-purity helium with a purity greater than 99.999% and a pressure of about 8 bar.

[0116] The helium storage system 300 is connected to both the high-pressure and low-pressure circuits of the refrigerator system 400 by pipelines. The helium storage system 300 can perform high and low pressure stamping or pressure relief on the refrigerator system 400 to maintain the stable operation of the refrigerator system 400.

[0117] The refrigeration system 400 is a Claude cycle refrigeration liquefaction device composed of a compressor 410, an oil removal and drying assembly 420, and a refrigeration cold box 430. Specifically, the refrigeration system 400 includes a set of helium compressors 410, an oil removal and drying assembly 420, and a refrigeration cold box 430. Among them, the helium compressor 410 can compress low-pressure helium gas at 1.05 bar to 13 bar to provide the original head. After the oil removal and drying assembly 420 removes oil and dries the incoming high-pressure helium gas, it is sent into the refrigeration cold box 430 to complete the Claude cycle. The refrigeration cold box 430 expands and cools the high-pressure helium gas at 300 K@13 bar to supercritical helium at 4.5 K@3.5 bar.

[0118] The superfluid helium acquisition system 500 integrates a 2K gas heater 510 and a superfluid helium pressure reduction and temperature reduction pump group 520. Among them, the superfluid helium pressure reduction and temperature reduction pump group 520 includes four sets of pump groups, and each set of pump groups includes a first-stage mechanical pump and a second-stage fore pump, which can provide a pressure reduction capacity of 2 g / s at 2K@3000 Pa under the rated power. The maximum power of the 2K gas heater 510 is 18 kW, which is used to heat the 2K gas to near room temperature and then send it into the superfluid helium pressure reduction and temperature reduction pump group 520 for pressure reduction.

[0119] The recovery and purification system 600 is a device for recovering and purifying helium gas. In the face of power failure, water supply interruption accidents, and when the safety valve and rupture disc are activated, the helium gas is recovered, purified, and sent back to the helium gas storage system 300.

[0120] The distribution and transmission system 200 is connected to the refrigeration system 400 and the vertical test distribution valve box 110, and undertakes the closed-loop circulation of all low-temperature and normal-temperature helium gas.

[0121] In an embodiment of the present invention, the distribution and transmission system 200 includes a multi-channel transmission pipeline 210, a normal-temperature pipeline 220, and a low-pressure branch 230. The multi-channel transmission pipeline 210 includes a cold shield gas supply pipeline 211, a cold shield gas return pipeline 212, a 4.5K gas supply pipeline 213, and a 2K gas return pipeline 214. The normal-temperature pipeline 220 includes a temperature reduction gas return pipeline 221 and a rewarming gas supply pipeline 222.

[0122] Among them, one end of the cold shield gas supply pipeline 211, the cold shield gas return pipeline 212, and the 4.5K gas supply pipeline 213 is connected to the refrigeration cold box 430. The other end of the cold shield gas supply pipeline 211 is connected to the input end of the cold shield gas inlet pipeline 131. The other end of the cold shield gas return pipeline 212 is connected to the output end of the cold shield gas return pipeline 132. The other end of the 4.5K gas supply pipeline 213 is connected to the input end of the supercritical helium inlet pipeline 133. The input end of the 2K gas return pipeline 214 is connected to the output end of the helium vapor return pipeline 134, and the output end of the 2K gas return pipeline 214 is connected to the 2K gas heater 510 of the superfluid helium acquisition system 500.

[0123] One end of the cooling return gas pipeline 221 is communicated with the cold box 430 of the refrigerator, and the other end of the cooling return gas pipeline 221 is communicated with the cooling return gas pipeline 136; one end of the reheating supply gas pipeline 222 is communicated with the pipeline between the oil removal and drying assembly 420 and the cold box 430 of the refrigerator, and the other end of the reheating supply gas pipeline 222 is communicated with the reheating supply gas pipeline 135.

[0124] One end of the low-pressure path branch 230 is communicated with the cold box 430 of the refrigerator, and the other end of the low-pressure path branch 230 is communicated with the negative pressure protection shell.

[0125] Specifically, a first cryogenic valve CV01 is arranged at one end of the 4.5K supply gas pipeline 213 close to the cold box 430 of the refrigerator, a second cryogenic valve CV02 is arranged at one end of the cold shield supply gas pipeline 211 close to the cold box 430 of the refrigerator, a third cryogenic valve CV03 is arranged at one end of the cold shield return gas pipeline 212 close to the cold box 430 of the refrigerator, a fourth cryogenic valve CV04 is arranged at one end of the cooling return gas pipeline 221 close to the cold box 430 of the refrigerator, and a fifth cryogenic valve CV05 is arranged at one end of the low-pressure path branch 230 close to the cold box 430 of the refrigerator; a switching valve PV01 is arranged at one end of the reheating supply gas pipeline 222 close to the cold box 430 of the refrigerator.

[0126] The refrigerator system 400 sends supercritical helium gas at 4.5 K@3 bar into the vertical test dewar 120 through the 4.5K supply gas pipeline 213 and the supercritical helium inlet pipeline 133; the return gas in the vertical test dewar 120 is sent back to the refrigerator system 400 through the helium vapor return pipeline 134 and the cooling return gas pipeline 221; in the 2K mode, the 2K gas in the vertical test dewar 120 is sent into the superfluid helium acquisition system 500 through the 2K return gas pipeline 214 and the helium vapor return pipeline 134, and is sent back to the refrigerator system 400 through the superfluid helium acquisition system 500.

[0127] The refrigerator system 400 sends low-temperature helium gas at 50K@7 bar into the valve box cold shield 112 and the dewar cold shield 123 through the cold shield supply gas pipeline 211 and the cold shield inlet pipeline 131, and sends the cold shield return gas at 75K@6 bar back to the refrigerator system 400 through the cold shield return pipeline 132 and the cold shield return gas pipeline 212, or the cold shield return gas can also be sent back to the refrigerator system 400 through the cold shield return pipeline 132 and the cooling return gas pipeline 221.

[0128] The refrigerator system 400 sends high-pressure helium gas at 300K@4 bar into the first mixing heater Mix1 through the reheating supply gas pipeline 135 and the fifth normal-temperature valve WV05, and into the second mixing heater Mix2 through the sixth normal-temperature valve WV06 and the third one-way valve VN03.

[0129] The refrigeration system 400 sends the normal-temperature helium gas at 300K@1.05bar into the negative-pressure protection and safety relief integrated device through the low-pressure branch 230, maintaining a slightly positive pressure environment inside the negative-pressure protection and safety relief integrated device to prevent air from invading the refrigeration system 400 through the safety valve.

[0130] The superfluid helium acquisition system 500 is connected to the 2K return gas pipeline 214. After the superfluid helium acquisition system 500 is turned on, the liquid helium in the vertical test dewar 120 is prepared into superfluid helium, and the pumped-back 2K gas is heated to normal temperature and then sent back to the refrigeration system 400.

[0131] Optionally, the test system further includes a control integration system, which is electrically connected to all temperature sensors, positive pressure sensors, negative pressure sensors, 4.5K liquid helium level gauge LT01, 2K superfluid helium level gauge LT02, fluid-contact DC power heater HT01, solid-contact DC power heater HT02, cryogenic valves, flow meters, normal-temperature valves, gate valves, vertical test distribution valve box vacuum acquisition equipment, vertical test dewar vacuum acquisition equipment, displacement pump group Pump3, sensors and controllers for the vertical test of superconducting cavities. The control integration system includes the automatic control of the controller and the data acquisition unit of various sensors.

[0132] The vertical test system for multi-temperature regions of liquid helium and superfluid helium provided by the embodiment of the present invention can couple the experimental platform into the superfluid helium cryogenic system, providing an experimental platform system with multi-temperature regions, multi-cooling rates, multi-liquid level targets, and load-independent cooling and warming different from other existing systems. At the same time, it includes a control integration system that can access functions such as PLC automatic control, automatic sensor data acquisition, and hardware controller control.

[0133] The embodiment of the present invention also provides a method for using a vertical test system for multi-temperature regions of liquid helium and superfluid helium, and the method includes the following steps:

[0134] Step S1, evacuate the interlayer of the vertical test distribution valve box 110 and the interlayer of the vertical test dewar 120 through the vacuum acquisition equipment so that the interlayers of the vertical test distribution valve box 110 and the vertical test dewar 120 reach the preset vacuum state.

[0135] Step S2, open the displacement pump group Pump3, the normal-temperature valve connected to the displacement pump group Pump3, the cryogenic valves on the cold shield inlet gas pipeline 131, the cold shield return gas pipeline 132, the supercritical helium inlet gas pipeline 133, the helium vapor return gas pipeline 134, and the cryogenic valve connected to the cooling return gas pipeline 136 to evacuate the distribution and transmission system 200, the pipeline components, and the negative-pressure protection shell of the negative-pressure protection and safety relief integrated device; when the value of the pressure sensor is lower than the first preset pressure value, close the displacement pump group Pump3.

[0136] Step S3: The refrigeration system 400 fills the negative pressure protection shell of the pipeline assembly and the integrated device for negative pressure protection and safety relief with 300K helium through the distribution and transmission system 200. When the value of the pressure sensor reaches the second preset pressure value, stop filling the 300K helium and let it stand for the first predetermined time.

[0137] Step S4: Repeat Step S2 and Step S3 multiple times.

[0138] Step S5: Open the cryogenic valves on the cold shield inlet pipeline 131 and the cold shield return pipeline 132, open the second cryogenic valve CV02 and the third cryogenic valve CV03. The refrigeration system 400 cools the valve box cold shield 112 of the vertical test distribution valve box 110 and the dewar cold shield 123 of the vertical test dewar 120 through the distribution and transmission system 200.

[0139] Step S6: Open the cryogenic valves on the supercritical helium inlet pipeline 133 and the helium vapor return pipeline 134, open the first cryogenic valve CV01 and the fourth cryogenic valve CV04. The refrigeration system 400 supplies 4.5K liquid helium into the vertical test dewar 120 through the 4.5K gas supply pipeline 213 of the distribution and transmission system 200 and the supercritical helium inlet pipeline 133. The gas in the vertical test dewar 120 enters the refrigeration system 400 through the helium vapor return pipeline 134 and the cooling return pipeline 221 of the distribution and transmission system 200.

[0140] Step S7: When the liquid volume of the 4.5K liquid helium in the vertical test dewar 120 reaches the first required value, conduct the vertical test of the superconducting cavity in the 4.5K temperature range.

[0141] Step S8: Open the superfluid helium acquisition system 500, close the cryogenic valve of the output branch connecting the helium vapor return pipeline 134 and the cooling return pipeline 136, open the cryogenic valve of the output branch connecting the helium vapor return pipeline 134 and the 2K return pipeline 214, that is, close the eleventh cryogenic valve CV11 and open the tenth cryogenic valve CV10. Obtain 2K superfluid helium in the vertical test dewar 120. When the liquid volume of the 4.5K liquid helium in the vertical test dewar 120 reaches the second required value, conduct the vertical test of the superconducting cavity in the 2K temperature range.

[0142] In a specific embodiment of the present invention, the usage method includes the following steps:

[0143] Step S1: Use a vacuum acquisition device to evacuate the interlayers of the vertical test distribution valve box 110 and the vertical test dewar 120 so that the interlayers of the vertical test distribution valve box 110 and the vertical test dewar 120 reach the preset vacuum state.

[0144] Specifically, close all valves except the first flap valve BV01 and the second flap valve BV02, activate the first vacuum pump group Pump1 of the vertical test distribution valve box vacuum acquisition device and the second vacuum pump group Pump2 of the vertical test dewar vacuum acquisition device. At the same time, observe the feedback data of the first vacuum silicon VS01 at the top of the vacuum chamber inside the vertical test distribution valve box 110 and the second vacuum silicon VS02 on the top cover of the vertical test dewar 120, so that the vacuum in the valve box vacuum interlayer of the vertical test distribution valve box 110 and the dewar vacuum interlayer of the vertical test dewar 120 maintains a vacuum state of the order of 1×10-4 Pa during the experimental period.

[0145] Step S2: Open the sixth cryogenic valve CV06 to the thirteenth cryogenic valve CV13 in the vertical test distribution valve box 110, and all normal temperature valves except the switching valves connected to the first temperature mixing device Mix1 and the second temperature mixing device Mix2, the fifth normal temperature valve WV05, and the sixth normal temperature valve WV06 (i.e., the first normal temperature valve WV01 to the fourth normal temperature valve WV04). Open the replacement pump group Pump3 to evacuate the multi-channel transmission pipeline 210, the normal temperature pipeline 220, the low-pressure branch 230, and each pipeline in the vertical test distribution valve box 110 connected to the distribution transmission system 200. Monitor the feedback data of the first pressure sensor P1 to the eighth pressure sensor P8 on each pipeline. When the maximum value among the values of the first pressure sensor P1 to the eighth pressure sensor P8 is lower than 100 Pa, close the replacement pump group Pump3 and the first normal temperature valve WV01 to the fourth normal temperature valve WV04; then open the switching valves, the fifth normal temperature valve WV05, and the sixth normal temperature valve WV06, and slowly fill helium gas at 300 K into the pipeline. When the maximum value among the values of the first pressure sensor P1 to the eighth pressure sensor P8 reaches 1.5 bar, close the switching valves, the fifth normal temperature valve WV05, and the sixth normal temperature valve WV06, and let it stand for about 15 minutes to allow the helium gas to fully diffuse into each pipeline, completing one gas replacement process inside the pipeline.

[0146] Step S3: Repeat Step S2 multiple times to ensure the replacement effect.

[0147] Exemplarily, in this embodiment, Step S2 is repeated five times to fully ensure the replacement effect; of course, the number of repetitions is not limited to five times, and can also be four times, six times, or more times.

[0148] Step S4: Open the second low-temperature valve CV02 and the third low-temperature valve CV03, open the eighth low-temperature valve CV08 and the twelfth low-temperature valve CV12, and maintain the opening of the twelfth low-temperature valve CV12 above 90%. Gradually increase the opening of the twelfth low-temperature valve CV12 to cool the valve box cold shield 112 of the vertical test distribution valve box 110 and the dewar cold shield 123 of the vertical test dewar 120. Obtain the value of the sixth temperature sensor T6. When the value of the sixth temperature sensor T6 stabilizes at 75K, open and slowly increase the opening of the thirteenth low-temperature valve CV13, and slowly close the twelfth low-temperature valve CV12 to improve cold recovery.

[0149] Step S5: After the value of the sixth temperature sensor T6 stabilizes at 75K, open the first low-temperature valve CV01 and the fourth low-temperature valve CV04. These valves are controlled by the control integration system to maintain the stable operation of the system. At the same time, close the eleventh low-temperature valve CV11, open the tenth low-temperature valve CV10, and then open the seventh low-temperature valve CV07. The supercritical helium at 4.5K @ 3.5 bar in the refrigerator cold box 430 does not pass through the negative pressure heat exchanger 140 and directly flows into the seventh low-temperature valve CV07. Gradually and slowly increase the opening of the seventh low-temperature valve CV07 to prepare liquid helium at 4.5K @ 1.3 bar in the vertical test dewar 120. Assign a small opening to the sixth low-temperature valve CV06 that flows through the negative pressure heat exchanger 140 and then into the vertical test dewar 120 to cool the negative pressure heat exchanger 140.

[0150] Step S6: Control the opening of the seventh low-temperature valve CV07 through the control integration system so that the value of the 4.5K liquid helium level gauge LT01 in the vertical test dewar 120 is 80%. At the same time, limit the opening of the seventh low-temperature valve CV07 to the lowest opening of 10% to prevent overpressure in the pipeline, causing the bursting disc to burst and the safety valve to operate. At the same time, the control integration system controls the output of the fluid contact DC power heater HT01 so that the value of the 4.5K liquid helium level gauge LT01 is 90% to prevent excessive cold output from the refrigerator system 400 and excessive overflow of liquid helium into the return pipeline.

[0151] Step S7: According to the requirements of the superconducting cavity vertical test, the control integration system controls the value of the 4.5K liquid helium level gauge LT01 to reach the required value and maintains the required time interval for the vertical test of the superconducting cavity in the 4.5K temperature range. The required data is transmitted back to the control integration system by the first sensor VT01 and the second sensor VT02.

[0152] Step S8: Open the 2K gas heater 510 of the superfluid helium acquisition system 500 and preheat for a second predetermined time so that the temperature of the helium gas entering the superfluid helium decompression and cooling pump group 520 reaches above 270K.

[0153] It is understandable that the temperature of the helium gas entering the superfluid helium decompression and cooling pump set 520 is 270 - 300K. Preheat the 2K gas heater for 10 minutes to fully heat the 2K gas heater 510.

[0154] Step S9: After the value of the 4.5K liquid helium level gauge LT01 reaches 80%, turn on the superfluid helium decompression and cooling pump set 520 and the 2K gas heater 510 in the superfluid helium acquisition system 500. Gradually close the seventh cryogenic valve CV07, close the eleventh cryogenic valve CV11, and slowly open the tenth cryogenic valve CV10 leading to the superfluid helium acquisition system 500. Monitor that the temperature of the helium gas entering the superfluid helium decompression and cooling pump set 520 is not lower than 260K. Gradually increase the sixth cryogenic valve CV06 through which the fluid flows into the vertical test dewar 120 after passing through the negative pressure heat exchanger 140, and start throttling and decompressing to obtain superfluid helium at 2K @ 0.03bar.

[0155] Step S10: When the state of the liquid helium in the vertical test dewar 120 changes from 4.5K @ 1.3 bar to superfluid helium at 2K @ 0.03bar, according to the requirements of the vertical test of the superconducting cavity, the gas flows through the negative pressure heat exchanger 140 and the sixth cryogenic valve CV06 and then into the vertical test dewar 120. Control the value of the 2K superfluid helium level gauge LT02 to reach the required value and maintain the required time interval for the 2K test.

[0156] Similarly, limit the minimum opening of the sixth cryogenic valve CV06 to 10% to prevent overpressure in the pipeline, causing the rupture disc to burst and the safety valve to operate. At the same time, control the output of the fluid contact type DC power heater HT01 so that the value of the 2K superfluid helium level gauge is 90%, preventing excessive cooling capacity output by the refrigerator system 400 and excessive overflow of liquid helium into the return pipeline. After completing the above operations, maintain the required time interval for the vertical test of the superconducting cavity in the 2K temperature range, and the required data is transmitted back to the control integration system by the first sensor VT01 and the second sensor VT02.

[0157] Step S11: After the test is completed, open the eleventh cryogenic valve CV11, close the tenth cryogenic valve CV10, turn off the superfluid helium acquisition system 500, gradually close the second cryogenic valve CV02 and the first cryogenic valve CV01 on the 4.5K gas supply pipeline of the refrigerator system 400, and stop supplying cold to the vertical test distribution valve box 110 and the vertical test dewar 120.

[0158] Step S12: Turn on the fluid contact type DC power heater HT01 and set it to about 80% of full power. Wait until the value of the 4.5K liquid helium level gauge LT01 is 0, and then turn off the fluid contact type DC power heater HT01.

[0159] Step S13: Turn on the solid-contact DC power heater HT02 and set it to about 80% of the full power. When the value of the ninth temperature sensor T9 disposed around the solid-contact DC power heater HT02 inside the vertical test dewar 120 reaches 70K, turn off the fluid-contact DC power heater HT01.

[0160] Step S14: Open the switch valve PV01, the fifth normal-temperature valve WV05 and the sixth normal-temperature valve WV06 on the rewarming return gas pipeline, and input 300K normal temperature into the vertical test distribution valve box 110 and the vertical test dewar 120 to accelerate the rewarming speed.

[0161] Step S15: Wait until the values of the first temperature sensor T1 of the vertical test distribution valve box 110 and the ninth temperature sensor T9 of the vertical test dewar 120 are close to normal temperature, and then turn off the first vacuum pump group Pump1 connected to the vertical test distribution valve box 110 and the second vacuum pump group Pump2 connected to the vertical test dewar 120.

[0162] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vertical testing platform for multi-temperature zones of liquid helium and superfluid helium, characterized in that: include: A vertical test distribution valve box having a valve box cold shield; A vertical test dewar, wherein the vertical test dewar has a dewar cold shield; A pipeline assembly is arranged in a vertical test distribution valve box, wherein the pipeline assembly includes a cold screen air intake pipeline, a cold screen air return pipeline, a supercritical helium air intake pipeline and a helium steam air return pipeline, wherein the cold screen air intake pipeline, the cold screen air return pipeline, the supercritical helium air intake pipeline and the helium steam air return pipeline are all provided with a cryogenic valve, a pressure sensor and a temperature sensor, wherein the input end of the cold screen air intake pipeline and the input end of the supercritical helium air intake pipeline are both connected to a distribution transmission system, the output end of the cold screen air intake pipeline is connected to the valve box cold screen and the Dewar cold screen, and the output end of the supercritical helium air intake pipeline is connected to the valve box cold screen and the Dewar cold screen. The vertical test dewar cavity is connected; the output end of the cold screen return air pipeline and the output end of the helium steam return air pipeline are both connected to the distribution and transmission system, the input end of the cold screen return air pipeline is connected to the valve box cold screen and the dewar cold screen, and the input end of the helium steam return air pipeline is connected to the vertical test dewar cavity; the supercritical helium intake pipeline and the helium steam return air pipeline are provided with a negative pressure heat exchanger; the cold screen intake pipeline and the cold screen return air pipeline are connected to a safety discharge device, and the helium steam return air pipeline is connected to a negative pressure protection and safety discharge integrated device; a replacement pump group, connected to the cold shield return air pipeline and the helium steam return air pipeline; A vacuum acquisition device connected to the vertical test distribution valve box and the vertical test Dewar; Wherein, the supercritical helium intake pipeline comprises: A first air inlet pipeline, wherein the input end of the first air inlet pipeline is connected to the 4.5K air supply pipeline of the distribution and transmission system, and the output end is connected to the inner cavity of the vertical test dewar, and the negative pressure heat exchanger is arranged on the first air inlet pipeline; A second air inlet pipeline, wherein the input end of the second air inlet pipeline is communicated with the first air inlet pipeline and is located at the inlet side corresponding to the negative pressure heat exchanger, and the output end of the second air inlet pipeline is communicated with the inner cavity of the vertical test dewar.

2. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to claim 1, characterized in that: The cold screen return air pipeline has two output branches, one of which is connected to the cold screen return air pipeline of the distribution and transmission system through a low-temperature valve, and the other output branch is connected to the cooling return air pipeline through a low-temperature valve; The helium steam return gas pipeline has two output branches, one of which is connected to the 2K return gas line of the distribution and transmission system through a low-temperature valve, and the other output branch is connected to the cooling return gas pipeline through a low-temperature valve, and the cooling return gas pipeline is connected to the cooling return gas line of the distribution and transmission system.

3. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to claim 1, characterized in that: The cold screen air inlet pipeline is provided with a first temperature mixer, and the first temperature mixer is connected to the re-temperature air supply pipeline of the distribution transmission system through a normal temperature valve; The second air inlet pipeline is provided with a second temperature mixer, and the second temperature mixer is connected to the re-temperature air supply pipeline of the distribution and transmission system through a normal temperature valve.

4. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to any one of claims 1 to 3, characterized in that: The safety relief device comprises a safety valve and a bursting disc.

5. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to any one of claims 1 to 3, characterized in that: The negative pressure protection and safety release integrated device comprises a negative pressure protection shell, a primary safety valve, a secondary safety valve and a bursting disc; The negative pressure protection shell is connected to the low-pressure branch of the distribution and transmission system, the replacement pump group and the recovery and purification system respectively; the primary safety valve is arranged in the negative pressure protection shell and is connected to the helium steam return gas pipeline, the secondary safety valve and the bursting disc are connected to the negative pressure protection shell in sequence, and the secondary safety valve and the bursting disc are connected to the atmosphere.

6. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to claim 5, characterized in that: A one-way valve is provided between the primary safety valve and the helium steam return pipeline.

7. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to any one of claims 1 to 3, characterized in that: The vertical test dewar is provided with a heater and / or a liquid level gauge.

8. A vertical testing system for multi-temperature zones of liquid helium and superfluid helium, characterized in that: It comprises a helium storage system, a refrigerator system, a distribution and transmission system, a superfluid helium acquisition system and a vertical testing platform for liquid helium and superfluid helium in multiple temperature zones as claimed in any one of claims 1 to 7.

9. A method for using the vertical testing system for multi-temperature zones of liquid helium and superfluid helium according to claim 8, characterized in that: include: Step S1, evacuating the interlayer of the vertical test distribution valve box and the interlayer of the vertical test dewar by a vacuum acquisition device, so that the interlayer of the vertical test distribution valve box and the vertical test dewar reaches a preset vacuum state; Step S2, open the replacement pump group, the normal temperature valve connected to the replacement pump group, the low temperature valves of the cold screen air inlet pipeline, the cold screen air return pipeline, the supercritical helium air inlet pipeline, the helium steam air return pipeline, and the low temperature valve connected to the cooling air return pipeline, so as to evacuate the distribution transmission system, the pipeline components and the negative pressure protection and safety discharge integrated device; when the value of the pressure sensor is lower than the first preset pressure value, close the replacement pump group; Step S3, the refrigerator system injects 300K helium into the pipeline assembly and the negative pressure protection shell of the negative pressure protection and safety relief integrated device through the distribution transmission system, and when the value of the pressure sensor reaches the second preset pressure value, stops injecting 300K helium and stands for a first preset time; Step S4, repeating steps S2 and S3 multiple times; Step S5, opening the low-temperature valves of the cold shield air inlet pipeline and the cold shield air return pipeline, and the refrigerator system cools down the valve box cold shield of the vertical test distribution valve box and the dewar cold shield of the vertical test dewar through the distribution transmission system; Step S6, opening the cryogenic valves of the supercritical helium inlet pipeline and the helium steam return pipeline, the refrigerator system introduces 4.5K liquid helium into the vertical test dewar through the 4.5K gas supply pipeline of the distribution and transmission system and the supercritical helium inlet pipeline, and the gas in the vertical test dewar enters the refrigerator system through the helium steam return pipeline and the cooling return pipeline of the distribution and transmission system; Step S7, vertically testing that the amount of 4.5K liquid helium in the Dewar reaches a first required value, and performing a superconducting cavity vertical test in a 4.5K temperature range; Step S8, open the superfluid helium acquisition system, close the cryogenic valve of the output branch connecting the helium vapor return gas pipeline and the cooling return gas pipeline, open the cryogenic valve of the output branch connecting the helium vapor return gas pipeline and the 2K return gas pipeline, obtain 2K superfluid helium in the vertical test Dewar, and when the liquid amount of 4.5K liquid helium in the vertical test Dewar reaches the second required value, perform the superconducting cavity vertical test in the 2K temperature zone.

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