Vertical test platform, system and method for multiple temperature zones of liquid helium and superfluid helium

Abstract

The invention relates to the technical field of accelerators, and provides a vertical test platform, system and method for multiple temperature zones of liquid helium and superfluid helium. The platform comprises a vertical test distribution valve box with a valve box cold screen, a vertical test Dewar with a Dewar cold screen, a displacement pump set, vacuum acquisition equipment, a cold screen air inlet pipeline, a cold screen air return pipeline, a supercritical helium inlet pipeline and a helium steam return pipeline, and the output of the cold screen air inlet pipeline is communicated with the valve box cold screen and the Dewar cold screen. The output of the supercritical helium inlet pipeline is communicated with the vertical test Dewar; the input of the cold screen air return pipeline is communicated with the valve box cold screen and the Dewar cold screen, and the input of the helium steam air return pipeline is communicated with the vertical test Dewar; by arranging a low-temperature valve, a pressure sensor and a temperature sensor on the cold screen air inlet pipeline, the cold screen air return pipeline, the supercritical helium air inlet pipeline and the helium steam air return pipeline, performance parameters of the superconducting cavity in 4.5 K and 2K temperature zones can be obtained, and support is provided for design and manufacturing of the superconducting cavity related to the superconducting accelerator.

Description

Technical Field

[0001] The present invention relates to the field of accelerator technology, and in particular to a vertical testing platform, system and method for multi-temperature zones of liquid helium and superfluid helium. Background Art

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

[0003] In the prior art, there are many types of superconducting accelerators, and vertical tests need to be performed on superconducting cavities of different types one by one. Superconducting cavities of different types have different vertical test environments and tests. Therefore, it is an important issue that the industry needs to solve urgently to develop a vertical test platform for superconducting cavities of different types, realize multi-temperature zones, strong operational similarity, and highly reliable vertical test experimental research. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a vertical testing platform, system and method for liquid helium and superfluid helium in multiple temperature zones, which can obtain the performance parameters of superconducting cavities in the 4.5K and 2K temperature zones, and provide data support for the design, manufacture and processing of superconducting cavities related to superconducting accelerators.

[0005] The present invention provides a vertical testing platform for multi-temperature zones of liquid helium and superfluid helium, comprising: 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 is connected to the vertical test distribution valve box and the vertical test Dewar.

[0006] According to a vertical testing platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention, 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 line of the distribution and transmission system, the output end of the first air inlet pipeline 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, the input end of which 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 which is communicated with the inner cavity of the vertical test dewar.

[0007] According to a vertical test platform for liquid helium and superfluid helium multi-temperature zones provided by the present invention, the cold shield return air pipeline has two output branches, one of which is connected to the cold shield return air pipeline of the distribution and transmission system through a cryogenic valve, and the other output branch is connected to the cooling return air pipeline through a cryogenic 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.

[0008] According to a vertical test platform for liquid helium and superfluid helium multi-temperature zones provided by the present invention, 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 and 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.

[0009] According to a vertical testing platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention, the safety relief device includes a safety valve and a bursting disc.

[0010] According to a vertical testing platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention, 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.

[0011] According to a vertical test platform for liquid helium and superfluid helium in multiple temperature zones provided by the present invention, a one-way valve is provided between the primary safety valve and the helium steam return line.

[0012] According to a vertical test platform for multi-temperature zones 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.

[0013] The present invention also provides a vertical testing system for multiple temperature zones of liquid helium and superfluid helium, comprising a helium storage system, a refrigerator system, a distribution and transmission system, a superfluid helium acquisition system, and a vertical testing platform for multiple temperature zones of liquid helium and superfluid helium as described in any one of the above.

[0014] The present invention also provides a method for using a vertical testing system for liquid helium and superfluid helium in multiple temperature zones, comprising the following steps: 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 assembly 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.

[0015] The vertical test platform for multi-temperature zones of liquid helium and superfluid helium provided by the present invention has a pipeline assembly arranged in a vertical test distribution valve box, and low-temperature valves, pressure sensors and temperature sensors are arranged on a cold shield air inlet pipeline, a cold shield air return pipeline, a supercritical helium air inlet pipeline and a helium steam air return pipeline. The platform can provide a stable low-temperature environment for a superconducting cavity in the 4.5K and 2K temperature zones according to the design requirements of the superconducting cavity, and can accurately obtain vertical tests of the superconducting cavity in the 4.5K and 2K temperature zones, obtain 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

[0016] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a structural schematic diagram of a vertical testing system for multi-temperature zones of liquid helium and superfluid helium provided by the present invention.

[0018] Figure 2 It is a structural schematic diagram of a vertical testing platform for liquid helium and superfluid helium multi-temperature zones provided by the present invention.

[0019] Figure 3 It is a partial structural schematic diagram of a vertical testing system for liquid helium and superfluid helium multi-temperature zones provided by the present invention.

[0020] Figure 4 yes Figure 2 Schematic diagram of the local enlarged structure at point A in the middle.

[0021] Figure 5 yes Figure 2 Schematic diagram of the local enlarged structure at point B in the middle.

[0022] Figure 6 yes Figure 2 Schematic diagram of the local enlarged structure at point C in the middle.

[0023] Figure 7 yes Figure 3 Schematic diagram of the local enlarged structure at point D in the middle.

[0024] Reference numerals: 100. Vertical test platform; 110. Vertical test distribution valve box; 111. Valve box vacuum cover; 112. Valve box cold screen; 120. Vertical test dewar; 121. Dewar inner wall; 122. Dewar outer wall; 123. Dewar cooling shield; 131. Cold screen air inlet pipeline; 132. Cold screen air return pipeline; 133. Supercritical helium air inlet pipeline; 134. Helium steam air return pipeline; 135. Rewarming air supply pipeline; 136. Cooling air return pipeline; 140. Negative pressure heat exchanger; CV01, the first cryogenic valve; CV02, the second cryogenic valve; CV03, the third cryogenic valve; CV04, the fourth cryogenic valve; CV05, the fifth cryogenic valve; CV06, the sixth cryogenic valve; CV07, the seventh cryogenic valve; CV08, the eighth cryogenic valve; CV09, the ninth cryogenic valve; CV10, the tenth cryogenic valve; CV11, the eleventh cryogenic valve; CV12, the twelfth cryogenic valve; CV13, the thirteenth cryogenic valve; 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; 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; WV01, the first normal temperature valve; WV02, the second normal temperature valve; WV03, the third normal temperature valve; WV04, the fourth normal temperature valve; WV05, the fifth normal temperature valve; WV06, the sixth normal temperature valve; SV01, first safety valve; BP01, first bursting disc; SV02-1, first-level second safety valve; SV02-2, second-level second safety valve; BP02, second bursting disc; SVG01, first negative pressure protection shell; SV03-1, first-level third safety valve; SV03-2, second-level third safety valve; BP03, third bursting disc; SVG02, second negative pressure protection shell; SV04, the fourth safety valve; BP04, the fourth bursting disc; Mix1, first temperature mixer; Mix2, second temperature mixer; VN01, first check valve; VN02, second check valve; VN03, third check valve; PV01, switch valve; VS01, first vacuum silicon; Pump3, displacement pump group; BV01, first gate valve; BV02, second gate valve; Pump1, first vacuum pump group; Pump2, second vacuum pump group; VS02, second vacuum silicon; HT01, fluid contact DC power heater; HT02, solid contact DC power heater; LT01, 4.5 K liquid helium level gauge; LT02, 2 K superfluid helium level gauge; VT01, the first sensor; VT02, the second sensor; 200, distribution and transmission system; 210, multi-channel transmission pipeline; 211, cold screen air supply pipeline; 212, cold screen air return pipeline; 213, 4.5K air supply pipeline; 214, 2K air return pipeline; 220, normal temperature pipeline; 221, cooling air return pipeline; 222, rewarming air supply pipeline; 230, low pressure branch; 300. Helium storage system; 400, refrigeration system; 410, compressor; 420, degreasing and drying component; 430, refrigeration box; 500. Superfluid helium acquisition system; 510. 2K gas heater; 520. Superfluid helium decompression and cooling pump group; 600. Recovery and purification system. DETAILED DESCRIPTION

[0025] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0026] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0027] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" 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 a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0028] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0029] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0030] The embodiment of the first aspect of the present invention provides a vertical testing platform for multi-temperature zones of liquid helium and superfluid helium, such as Figure 1 and Figure 2 As shown, the vertical test platform includes a vertical test distribution valve box 110, a vertical test dewar 120, a pipeline assembly, a replacement pump group Pump3 and a vacuum acquisition device.

[0031] like Figures 4 to 6As shown, 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 air intake pipeline 131, a cold shield air return pipeline 132, a supercritical helium air intake pipeline 133 and a helium steam air return pipeline 134, and the cold shield air intake pipeline 131, the cold shield air return pipeline 132, the supercritical helium air intake pipeline 133 and the helium steam air return pipeline 134 are all provided with low-temperature valves, pressure sensors and temperature sensors, the input end of the cold shield air intake pipeline 131 and the input end of the supercritical helium air intake pipeline 133 are both connected to the distribution and transmission system 200, the output end of the cold shield air intake pipeline 131 is connected to the valve box cold shield 112 and the dewar cold shield 123, and the output end of the supercritical helium air intake pipeline 133 is connected to the inner cavity of the vertical test dewar 120; the cold shield air return pipeline 132 The output end of the air pipeline 132 and the output end of the helium steam return pipeline 134 are both connected to the distribution and transmission system 200, the input end of the cold screen return pipeline 132 is connected to the valve box cold screen 112 and the dewar cold screen 123, and the input end of the helium steam return pipeline 134 is connected to the inner cavity of the vertical test dewar 120; the supercritical helium intake pipeline 133 and the helium steam return pipeline 134 are provided with a negative pressure heat exchanger 140; the cold screen intake pipeline 131 and the cold screen return pipeline 132 are connected to a safety relief device, and the helium steam return pipeline 134 is connected to a negative pressure protection and safety relief integrated device, which is located outside the vertical test distribution valve box 110; the replacement pump group Pump3 is connected to the cold screen return pipeline 132 and the helium steam return pipeline 134; the vacuum acquisition equipment 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 cryogenic valve is 2-300K.

[0032] The vertical test platform for multi-temperature zones of liquid helium and superfluid helium provided in the embodiment of the present invention has a pipeline assembly arranged in the vertical test distribution valve box 110, and low-temperature valves, pressure sensors and temperature sensors are arranged on the cold shield air inlet pipeline 131, the cold shield air return pipeline 132, the supercritical helium air inlet pipeline 133 and the helium steam air return pipeline 134. According to the design requirements of the superconducting cavity, a stable low-temperature environment of the superconducting cavity in the 4.5K and 2K temperature zones can be provided, so that 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, so as to provide data support for the design, manufacture and processing of superconducting cavities related to superconducting accelerators.

[0033] In one 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.

[0034] Specifically, Figure 5 As shown, the vertical test distribution valve box vacuum obtaining equipment 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 connected to the first vacuum pump group Pump1 through a flange. The first vacuum pump group Pump1 includes a primary mechanical pump and a secondary molecular pump.

[0035] like Figure 6 As shown, the vertical test dewar vacuum obtaining equipment 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 connected to the second vacuum pump group Pump2 through a flange, and the second vacuum pump group Pump2 includes a primary mechanical pump and a secondary molecular pump.

[0036] In one embodiment of the present invention, Figure 5 As shown, the vertical test distribution valve box 110 is a double-layer structure, specifically including a valve box vacuum cover 111 and a valve box cold screen 112 arranged in the valve box vacuum cover 111, the valve box cold screen 112 is used to reduce the radiation 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 screen 112, and the vertical test distribution valve box vacuum acquisition equipment is used to evacuate the valve box vacuum interlayer.

[0037] The valve box vacuum interlayer is provided with a first vacuum silicon VS01, which is electrically connected to a vacuum monitor and is used to detect the vacuum state of the inner interlayer (ie, the valve box vacuum interlayer) of the vertical test distribution valve box 110.

[0038] Furthermore, an eighth temperature sensor T8 is arranged on the valve box cold screen 112, and the eighth temperature sensor T8 is used to determine the cooling state of the valve box cold screen 112; preferably, the number of the eighth temperature sensor T8 can be multiple. In this embodiment, the valve box vacuum cover 111 and the valve box cold screen 112 are hexahedral structures, the valve box vacuum cover 111 has six panels, and the valve box cold screen 112 has six cold screen surfaces matching the six panels. The number of the eighth temperature sensors T8 is six, which are respectively arranged on the six cold screen surfaces.

[0039] In one embodiment of the present invention, 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, and the Dewar cold shield 123 is used to reduce the radiation heat leakage of the internal cold fluid to the ambient temperature; the vertical test Dewar vacuum acquisition equipment is used to evacuate the Dewar vacuum interlayer, and the Dewar vacuum interlayer is provided with a second vacuum silicon VS02, the second vacuum silicon VS02 is electrically connected to the vacuum monitor, and the second vacuum silicon VS02 is used to detect the vacuum state of the internal interlayer of the vertical test Dewar 120.

[0040] Furthermore, the vertical test dewar 120 is provided with a liquid level gauge; specifically, the side and bottom of the dewar outer wall 122 are arranged with a dewar inner wall 121, so that an inner tank is surrounded by the top of the dewar inner wall 121 and the dewar outer wall 122, and the vertical test dewar 120 is provided with a 4.5 K liquid helium level gauge LT01 and a 2 K superfluid helium level gauge LT02 at a position close to the inner wall of the inner tank. The level gauges are vertically inserted into the inner tank of the vertical test dewar 120 to collect the liquid levels of 4.5 K liquid helium and 2 K superfluid helium, and they maintain the highest design accuracy in their respective applicable temperature ranges.

[0041] The vertical test dewar 120 is also provided with a VT sensor to obtain the no-load quality factor Q through the measurement data of the VT sensor. 0 and the accelerating field gradient E acc ; In this embodiment, the VT sensor includes a first sensor VT01 and a second sensor VT02 which are arranged on the top cover of the vertical test dewar 120.

[0042] Furthermore, an opening is provided at the top of the vertical test dewar 120. After being welded to the pressure outlet 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.

[0043] In one embodiment of the present invention, the vertical test dewar 120 is provided with a heater; optionally, the inner liner of the vertical test dewar 120 is provided with a fluid contact type DC power heater HT01; further, a solid contact type DC power heater HT02 is arranged on the inner wall 121 of the dewar.

[0044] Optionally, a ninth temperature sensor T9 is provided in the vertical test dewar 120 for determining 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.

[0045] In one embodiment of the present invention, Figure 1 , Figure 3 , Figure 5 and Figure 7 As shown, the input end of the cold screen air intake pipeline 131 is connected to the cold screen air supply line 211 of the distribution and transmission system 200, the output end of the cold screen air intake pipeline 131 is connected to the Dewar cold screen 123, the cold screen air intake pipeline 131 is connected to the valve box cold screen 112, and the cold screen air intake pipeline 131 is provided with an eighth cryogenic valve CV08, a sixth pressure sensor P6 and a fifth temperature sensor T5, wherein 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 backup and the other for use.

[0046] The input end of the cold screen return air pipeline 132 is connected to the Dewar cold screen 123, the output end of the cold screen return air pipeline 132 is connected to the cold screen return air pipeline 212 of the distribution and transmission system 200, the cold screen return air pipeline 132 is connected to the valve box cold screen 112, and the cold screen return air pipeline 132 is provided with a thirteenth cryogenic valve CV13, a fifth pressure sensor P5 and a sixth temperature sensor T6; wherein, 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 backup and the other for use.

[0047] It can be understood that the vertical test distribution valve box 110 delivers about 50 K helium from the refrigerator system 400 into the valve box cold screen 112 and the Dewar cold screen 123 via the eighth cryogenic valve CV08, and the return gas after the valve box cold screen 112 and the Dewar cold screen 123 are cooled and reduced returns to the refrigerator system 400 after passing through the thirteenth cryogenic valve CV13 to cool the valve box cold screen 112 and the Dewar cold screen 123.

[0048] In one 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 gas supply line 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 at the inlet side corresponding to 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.

[0049] Specifically, the first air intake pipeline is provided with 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, 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, and 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 air intake pipeline is connected between the third pressure sensor P3 and the third temperature sensor T3, the second air intake pipeline is provided with a seventh cryogenic valve CV07, a seventh pressure sensor P7 and a seventh temperature sensor T7, 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.

[0050] It can be understood that after the supercritical helium gas at 4.5K @ 3.5 bar from the refrigerator system enters the vertical test distribution valve box 110 through the input end of the first air inlet pipeline, it is divided into two branches and enters the vertical test dewar 120, one of which 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, and 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 decompression.

[0051] In one embodiment of the present invention, the cold screen air intake pipeline 131 is provided with a first temperature mixer Mix1, the first temperature mixer Mix1 is located between the eighth low-temperature valve CV08 and the sixth pressure sensor P6, the first temperature mixer Mix1 is connected to the rewarming air supply line 222 of the distribution and transmission system 200 through the rewarming air supply pipeline 135, and the rewarming air supply pipeline 135 is provided with a fifth normal temperature valve WV05; the second air intake pipeline is provided with a second temperature mixer Mix2, the second temperature mixer Mix2 is arranged between the seventh low-temperature valve CV07 and the seventh pressure sensor P7, the second temperature mixer Mix2 is connected to the rewarming air supply pipeline 135 through the sixth normal temperature valve WV06, wherein the sixth normal temperature valve WV06 and the fifth normal temperature valve WV05 are connected in parallel.

[0052] It can be understood that the high-pressure gas from the refrigerator system 400 is transmitted through the rewarming gas supply pipeline 222, and enters the first temperature mixer Mix1 through the fifth normal temperature valve WV05, and enters the dewar cold shield 123 of the vertical test dewar 120 after mixing with the helium from the eighth low temperature valve CV08. The high-pressure gas from the refrigerator system 400 enters the second temperature mixer Mix2 after passing through the sixth normal temperature valve WV06, and enters the vertical test dewar 120 after mixing with the incoming helium from the seventh low temperature valve CV07; wherein, the rewarming gas supply pipeline 135 is provided with a ninth pressure sensor P9, 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 temperature mixer Mix2, and the third one-way valve VN03 can effectively eliminate the influence of the 4.5K thermoacoustic oscillation on the measurement of the seventh pressure sensor P7.

[0053] Furthermore, the helium steam return pipeline 134 is provided with a first pressure sensor P1, a first temperature sensor T1, a second temperature sensor T2, a second pressure sensor P2 and a ninth cryogenic valve CV09. The ninth cryogenic 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 flow direction of the helium medium.

[0054] In one embodiment of the present invention, the negative pressure heat exchanger 140 is located inside the vertical test distribution valve box 110, and the first input port and the first output port of the negative pressure heat exchanger 140 are serially connected to the supercritical helium intake pipeline 133, and the second input port and the second output port of the negative pressure heat exchanger 140 are serially connected to the helium steam return pipeline 134. Specifically, the first input port and the first output port of the negative pressure heat exchanger 140 are serially connected 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 serially connected between the second temperature sensor T2 and the first temperature sensor T1.

[0055] Furthermore, high-precision pressure sensors and high-precision temperature sensors are provided on the input and output sides 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 used as a backup.

[0056] 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 is used as a backup; 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.

[0057] In one embodiment of the present invention, the helium vapor return gas pipeline 134 has two output branches, one of which is connected to the cooling return gas pipeline 221 of the distribution and transmission system 200 through the eleventh cryogenic valve CV11, and the other output branch is connected to the 2K return gas pipeline 214 of the distribution and transmission system 200 through the tenth cryogenic valve CV10.

[0058] Furthermore, the cold screen return air pipeline 132 is provided with a thirteenth cryogenic valve CV13, and the cold screen return air pipeline 132 on the inlet side of the thirteenth cryogenic valve CV13 is connected to the cooling return air pipeline 221 of the distribution and transmission system 200 through the twelfth cryogenic valve CV12.

[0059] It can be understood that the cold shield return air pipeline 132 also has two output branches, one of which is connected to the cooling return air pipeline 221 of the distribution and transmission system 200 through the twelfth low-temperature valve CV12, and the other output branch is connected to the cold shield return air pipeline 212 of the distribution and transmission system 200 through the thirteenth low-temperature valve CV13.

[0060] Optionally, the output pipeline of the eleventh cryogenic valve CV11 and the output pipeline of the twelfth cryogenic valve CV12 are connected in the vertical test distribution valve box 110, and are connected to the cooling return gas pipeline 221 of the distribution transmission system 200 through the cooling return gas pipeline 136. Preferably, the cooling return gas pipeline 136 is provided with an eighth pressure sensor P8 located in the vertical test distribution valve box 110; the eighth pressure sensor P8 is a high-precision positive pressure sensor.

[0061] It can be understood that the thirteenth cryogenic valve CV13 and the twelfth cryogenic valve CV12 are connected in parallel, the twelfth cryogenic valve CV12 and the eleventh cryogenic valve CV11 are connected in parallel, and the eleventh cryogenic valve CV11 and the tenth cryogenic valve CV10 are connected in parallel, which can constitute all loops for returning gas under different working conditions, thereby realizing vertical testing of superconducting cavities under different working conditions, 4.5K and 2K temperature zones; the saturated helium 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.

[0062] In this embodiment, the sixth cryogenic valve CV06 to the thirteenth cryogenic valve CV13 are all pneumatic valves, wherein the sixth cryogenic valve CV06 and the seventh cryogenic valve CV07 are pneumatic Joule-Thomson throttle valves (JT valves), and the eighth cryogenic valve CV08 to the thirteenth cryogenic valve CV13 are all pneumatic regulating valves.

[0063] In one embodiment of the present invention, the safety relief device includes a protection pipeline and a safety valve and a bursting disc arranged in the protection pipeline.

[0064] Specifically, the cold screen return air pipeline 132 is connected to a first safety relief device, which includes a first connecting pipeline and a first safety valve SV01 and a first bursting piece BP01 arranged on the first connecting pipeline. The input end of the first connecting pipeline is connected to the cold screen return air pipeline 132 and is located between the fifth pressure sensor P5 and the sixth temperature sensor T6. The output end of the first connecting pipeline is connected to the recovery and purification system 600. The first safety valve SV01 and the first bursting piece BP01 are located outside the vertical test distribution valve box 110; wherein, the first safety valve SV01 is connected to the recovery and purification system 600, and the first bursting piece BP01 is connected to the atmosphere.

[0065] The cold screen air inlet pipeline 131 is connected to a second safety relief device, which includes a fourth connecting pipeline and a fourth safety valve SV04 and a fourth bursting disc BP04 arranged on the fourth connecting pipeline. The input end of the fourth connecting pipeline is connected to the cold screen air inlet pipeline 131 and is located on the inlet side of the eighth low-temperature valve CV08. The output end of the fourth connecting pipeline is connected to the recovery and purification system 600. The fourth safety valve SV04 and the fourth bursting disc BP04 are located outside the vertical test distribution valve box 110; wherein, the fourth safety valve SV04 is connected to the recovery and purification system 600, and the fourth bursting disc BP04 is connected to the atmosphere.

[0066] In one embodiment of the present invention, the negative pressure protection and safety discharge integrated device includes 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 displacement pump group and the recovery and purification system respectively; the primary safety valve is arranged in the negative pressure protection shell and connected to the helium steam return gas pipeline, and the secondary safety valve and the bursting disc are connected to the negative pressure protection shell in turn; wherein the secondary safety valve and the bursting disc are both connected to the atmosphere. It should be noted here that the low pressure in the low pressure branch is 1.05-1.3 bar.

[0067] Optionally, the helium steam return pipeline 134 is connected to two negative pressure protection and safety relief integrated devices, 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.

[0068] The first negative pressure protection and safety relief integrated device includes a second connecting pipeline, a first negative pressure protection shell SVG01, a first-level second safety valve SV02-1 (i.e., a first-level safety valve), a second-level second safety valve SV02-2 (i.e., a second-level safety valve) and a second bursting disc BP02. The input end of the second connecting pipeline is connected to the helium steam return gas pipeline 134 and is located at the inlet side of the ninth cryogenic valve CV09. The output end of the second connecting pipeline is connected to the first-level second safety valve SV02-1, and the first-level second safety valve SV02-1 is integrated in the first negative pressure protection shell SVG. 01, the first negative pressure protection shell SVG01 is connected with the recovery and purification system 600, the replacement outlet of the first negative pressure protection shell SVG01 is connected to the replacement pump group Pump3 through the fourth normal temperature valve WV04, the air inlet of the first negative pressure protection shell SVG01 is connected with the low-pressure branch 230 of the distribution and transmission system 200, and the exhaust port of the first negative pressure protection shell SVG01 is connected with the secondary second safety valve SV02-2 and the second bursting disc BP02 which are arranged in sequence, and the secondary second safety valve SV02-2 and the second bursting disc BP02 are connected with the atmosphere.

[0069] The second negative pressure protection and safety relief integrated device includes a third connecting pipeline, a second negative pressure protection shell SVG02, a first-level third safety valve SV03-1 (i.e., a first-level safety valve), a second-level third safety valve SV03-2 (i.e., a second-level safety valve) and a third bursting disc BP03. The input end of the third connecting pipeline is connected between the tenth cryogenic valve CV10 and the first pressure sensor P1, and the output end of the third connecting pipeline is connected to the first-level third safety valve SV03-1, and the first-level third safety valve SV03-1 is located in the second negative pressure protection shell SVG02. The second negative pressure protection shell SVG02 is connected to the recovery and purification system 600, the replacement outlet of the second negative pressure protection shell SVG02 is connected to the replacement pump group Pump3 through the third normal temperature valve WV03, the air inlet of the second negative pressure protection shell SVG02 is connected to the low-pressure branch 230 of the distribution and transmission system 200, and the exhaust port of the second negative pressure protection shell SVG02 is connected to the secondary third safety valve SV03-2 and the third bursting disc BP03 which are arranged in sequence, and the secondary third safety valve SV03-2 and the third bursting disc BP03 are connected to the atmosphere.

[0070] Furthermore, a one-way valve is provided between the primary safety valve and the helium steam return pipeline 134 .

[0071] Specifically, the input end of the second connecting pipeline is provided with a first one-way valve VN01 located in the vertical test distribution valve box 110, and the input end of the third connecting pipeline is provided with a second one-way valve VN02 located in the vertical test distribution valve box 110; the first one-way valve VN01 and the second one-way valve VN02 can prevent thermal acoustic shock below the 4.5K temperature zone, and avoid the safety valve and bursting disc from working due to erroneous pressure fluctuations.

[0072] Optionally, the third connecting pipeline is connected to the replacement pump group Pump3 through the first normal temperature valve WV01, and the first connecting pipeline is connected to the replacement 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 replacement pump group Pump3, and are used to evacuate the gas environment inside the replacement pipeline.

[0073] In this embodiment, the first normal temperature valve WV01 to the sixth normal temperature valve WV06 are all normal temperature pneumatic valves. like Figures 1 to 7 As shown, an embodiment of the present invention further provides a vertical testing system for multiple temperature zones of liquid helium and superfluid helium, the testing system comprising a helium storage system 300, a refrigerator system 400, a distribution and transmission system 200, a superfluid helium acquisition system 500 and the vertical testing platform 100 for multiple temperature zones of liquid helium and superfluid helium as described in any of the above embodiments.

[0074] Optionally, the test system also includes a recovery and purification system 600, the helium storage system 300 is connected to the refrigerator system 400, the refrigerator system 400 is connected to the vertical test platform 100 through the distribution and transmission system 200, the vertical test platform 100 is connected to the superfluid helium acquisition system 500 through the distribution and transmission system 200, the superfluid helium acquisition system 500 is connected to the input of the refrigerator system 400, and the vertical test platform 100 is connected to the refrigerator system 400 through the recovery and purification system 600.

[0075] In this embodiment, the helium storage system 300 is a high-pressure gas storage tank working 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, which contain high-pressure high-purity helium with a purity greater than 99.999% maintained at about 8 bar.

[0076] The helium storage system 300 is connected to the high-pressure circuit and the low-pressure circuit 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.

[0077] The refrigerator system 400 is a Kraut cycle refrigeration liquefaction device consisting of a compressor 410, an oil removal and drying component 420, and a refrigerator cold box 430; specifically, the refrigerator system 400 includes a set of helium compressors 410, oil removal and drying components 420 and refrigerator cold box 430, wherein the helium compressor 410 can compress low-pressure helium of 1.05 bar to 13 bar, providing the original pressure head, and the oil removal and drying component 420 deoils and dries the incoming high-pressure helium, and then sends it to the refrigerator cold box 430 to complete the Kraut cycle, and the refrigerator cold box 430 expands the high-pressure helium of 300 K@13 bar and cools it to supercritical helium of 4.5 K@3.5 bar.

[0078] The superfluid helium acquisition system 500 integrates a 2K gas heater 510 and a superfluid helium decompression and cooling pump set 520; wherein, the superfluid helium decompression and cooling pump set 520 includes four pump sets, each of which includes a first-stage mechanical pump and a second-stage fore pump, and can provide a decompression capacity of 2g / s at 2K@3000Pa at rated power. The maximum power of the 2K gas heater 510 is 18kW, which is used to heat the 2K gas to near room temperature and then send it into the superfluid helium decompression and cooling pump set 520 for decompression.

[0079] The recovery and purification system 600 is a set of equipment for recovering and purifying helium. In the event of power outages, water outages, or the tripping of safety valves and bursting discs, the helium is recovered and purified and sent back to the helium storage system 300.

[0080] The distribution and transmission system 200 connects the refrigerator system 400 and the vertical test distribution valve box 110 to receive the closed loop circulation of all low-temperature and room-temperature helium gases.

[0081] In one 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 air supply pipeline 211, a cold shield air return pipeline 212, a 4.5K air supply pipeline 213 and a 2K air return pipeline 214; the normal temperature pipeline 220 includes a cooling return air pipeline 221 and a rewarming air supply pipeline 222.

[0082] 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 are connected to the refrigerator 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, and the other end of the 4.5K gas supply pipeline 213 is connected to the input end of the supercritical helium gas inlet pipeline 133; the input end of the 2K gas return pipeline 214 is connected to the output end of the helium steam gas 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.

[0083] One end of the cooling return air pipeline 221 is connected to the refrigerator cold box 430, and the other end of the cooling return air pipeline 221 is connected to the cooling return air pipeline 136; one end of the rewarming air supply pipeline 222 is connected to the pipeline between the oil removal and drying component 420 and the refrigerator cold box 430, and the other end of the rewarming air supply pipeline 222 is connected to the rewarming air supply pipeline 135.

[0084] One end of the low-pressure branch 230 is communicated with the refrigerator cold box 430, and the other end of the low-pressure branch 230 is communicated with the negative pressure protection shell.

[0085] Specifically, a first cryogenic valve CV01 is provided at one end of the 4.5K gas supply pipeline 213 close to the refrigerator cold box 430, a second cryogenic valve CV02 is provided at one end of the cold screen gas supply pipeline 211 close to the refrigerator cold box 430, a third cryogenic valve CV03 is provided at one end of the cold screen return gas pipeline 212 close to the refrigerator cold box 430, a fourth cryogenic valve CV04 is provided at one end of the cooling return gas pipeline 221 close to the refrigerator cold box 430, and a fifth cryogenic valve CV05 is provided at one end of the low-pressure branch 230 close to the refrigerator cold box 430; a switch valve PV01 is provided at one end of the rewarming gas supply pipeline 222 close to the refrigerator cold box 430.

[0086] The refrigerator system 400 delivers supercritical helium at 4.5 K@3 bar into the vertical test dewar 120 through the 4.5 K gas supply line 213 and the supercritical helium inlet line 133; returns the return gas in the vertical test dewar 120 to the refrigerator system 400 through the helium steam return gas line 134 and the cooling return gas line 221; in the 2K mode, the 2K gas in the vertical test dewar 120 is delivered to the superfluid helium acquisition system 500 through the 2K return gas line 214 and the helium steam return gas line 134, and is returned to the refrigerator system 400 through the superfluid helium acquisition system 500.

[0087] The refrigerator system 400 delivers 50K@7 bar low-temperature helium into the valve box cold shield 112 and the Dewar cold shield 123 through the cold shield air supply pipeline 211 and the cold shield air inlet pipeline 131, and delivers 75K@6bar cold shield return air back to the refrigerator system 400 through the cold shield return air pipeline 132 and the cold shield return air pipeline 212. The cold shield return air can also be delivered back to the refrigerator system 400 through the cold shield return air pipeline 132 and the cooling return air pipeline 221.

[0088] The refrigerator system 400 delivers 300K@4bar high-pressure helium through the rewarming gas supply pipeline 135 into the first temperature mixer Mix1 through the fifth normal temperature valve WV05, and into the second temperature mixer Mix2 through the sixth normal temperature valve WV06 and the third one-way valve VN03.

[0089] The refrigerator system 400 delivers 300K@1.05bar room temperature helium into the negative pressure protection and safety relief integrated device through the low pressure branch 230, maintains a slightly positive pressure environment in the negative pressure protection and safety relief integrated device, and prevents air from invading the refrigerator system 400 through the safety valve.

[0090] 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 withdrawn 2K gas is heated to room temperature and then sent back to the refrigerator system 400.

[0091] Optionally, the test system also includes a control integration system, which is electrically connected to all temperature sensors, positive pressure sensors, negative pressure sensors, 4.5 K liquid helium level gauge LT01, 2 K superfluid helium level gauge LT02, fluid contact DC power heater HT01, solid contact DC power heater HT02, cryogenic valves, flow meters, normal temperature valves, plug valves, vertical test distribution valve box vacuum acquisition equipment, vertical test Dewar vacuum acquisition equipment, displacement pump group Pump3, sensors and controllers for superconducting cavity vertical testing, and the control integration system includes automatic control of the controller and data acquisition units for various sensors.

[0092] The vertical testing system for multiple temperature zones of liquid helium and superfluid helium provided in the embodiment of the present invention can couple the experimental platform into the superfluid helium cryogenic system, provide multiple temperature zones, multiple cooling rates, multiple liquid level targets, and an experimental platform system with independent load cooling and reheating that is different from other existing systems. At the same time, it includes a control integration system that can access the functions of PLC automatic control, automatic sensor data acquisition, and hardware controller control.

[0093] An embodiment of the present invention further provides a method for using a vertical testing system for multi-temperature zones of liquid helium and superfluid helium, the method comprising the following steps: Step S1, vacuuming the interlayer of the vertical test distribution valve box 110 and the interlayer of the vertical test dewar 120 by a vacuum acquisition device, so that the interlayer of the vertical test distribution valve box 110 and the vertical test dewar 120 reaches a preset vacuum state.

[0094] Step S2, open the replacement pump group Pump3, the normal temperature valve connected to the replacement pump group Pump3, the low-temperature valves on the cold screen air inlet pipeline 131, the cold screen air return pipeline 132, the supercritical helium air inlet pipeline 133, the helium steam air return pipeline 134, and the low-temperature valve connected to the cooling return pipeline 136, so as to evacuate the negative pressure protection shell of the distribution transmission system 200, the pipeline assembly 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 replacement pump group Pump3.

[0095] In step S3, the refrigerator system 400 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 200. When the value of the pressure sensor reaches the second preset pressure value, the injection of 300K helium is stopped and the system is left to stand for a first predetermined time.

[0096] Step S4, repeating steps S2 and S3 multiple times.

[0097] Step S5, open the low-temperature valves on the cold screen air inlet pipeline 131 and the cold screen air return pipeline 132, open the second low-temperature valve CV02 and the third low-temperature valve CV03, and the refrigeration system 400 cools down the valve box cold screen 112 of the vertical test distribution valve box 110 and the dewar cold screen 123 of the vertical test dewar 120 through the distribution transmission system 200.

[0098] 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, and the refrigerator system 400 introduces 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 refrigerator system 400 through the helium vapor return pipeline 134 and the cooling return pipeline 221 of the distribution and transmission system 200.

[0099] Step S7, vertically testing the amount of 4.5K liquid helium in the Dewar 120 to reach a first required value, and performing a vertical test of the superconducting cavity in a 4.5K temperature range.

[0100] Step S8, open the superfluid helium acquisition system 500, close the cryogenic valve of the output branch connecting the helium vapor return gas pipeline 134 and the cooling return gas pipeline 136, open the cryogenic valve of the output branch connecting the helium vapor return gas pipeline 134 and the 2K return gas pipeline 214, that is, close the eleventh cryogenic valve CV11, open the tenth cryogenic valve CV10, obtain 2K superfluid helium in the vertical test dewar 120, and when the liquid amount of 4.5K liquid helium in the vertical test dewar 120 reaches the second required value, perform the superconducting cavity vertical test in the 2K temperature zone.

[0101] In a specific embodiment of the present invention, the method of use comprises the following steps: Step S1, evacuate the interlayer of the vertical test distribution valve box 110 and the interlayer of the vertical test dewar 120 by using a vacuum acquisition device to make the interlayer of the vertical test distribution valve box 110 and the interlayer of the vertical test dewar 120 reach a preset vacuum state.

[0102] Specifically, close all valves except the first gate valve BV01 and the second gate valve BV02, activate the first vacuum pump group Pump1 of the vertical test distribution valve box vacuum acquisition equipment and the second vacuum pump group Pump2 of the vertical test Dewar vacuum acquisition equipment, and simultaneously observe the feedback data of the first vacuum silicon VS01 located on 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 of the valve box vacuum interlayer of the vertical test distribution valve box 110 and the Dewar vacuum interlayer of the vertical test Dewar 120 maintain a vacuum state of the order of 1×10-4Pa during the experimental period.

[0103] 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 (i.e., the first normal temperature valve WV01 to the fourth normal temperature valve WV04) except the switch valve connected to the first temperature mixer Mix1 and the second temperature mixer Mix2, the fifth normal temperature valve WV05, and the sixth normal temperature valve WV06, open the replacement pump group Pump3, evacuate the multi-channel transmission pipeline 210, the normal temperature pipeline 220 and the low-pressure branch 230, and each pipeline connected to the distribution transmission system 200 in the vertical test distribution valve box 110, and monitor the first pressure sensor P1 to the eighth pressure sensor P8 on each pipeline. According to the feedback data, when the maximum value of the values ​​from the first pressure sensor P1 to the eighth pressure sensor P8 is lower than 100Pa, close the replacement pump group Pump3 and the first normal temperature valve WV01 to the fourth normal temperature valve WV04; then open the switch valve, the fifth normal temperature valve WV05 and the sixth normal temperature valve WV06, and slowly inject 300K helium into the pipeline. When the maximum value of the values ​​from the first pressure sensor P1 to the eighth pressure sensor P8 reaches 1.5bar, close the switch valve, 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 to fully diffuse into each pipeline, completing a gas replacement process in the pipeline.

[0104] Step S3: repeat step S2 multiple times to ensure the replacement effect.

[0105] For example, 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 may also be four times, six times or more times.

[0106] Step S4, open the second cryogenic valve CV02 and the third cryogenic valve CV03, open the eighth cryogenic valve CV08 and the twelfth cryogenic valve CV12, and maintain the opening of the twelfth cryogenic valve CV12 at more than 90%, gradually increase the opening of the twelfth cryogenic valve CV12, 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 to 75K, open and slowly and gradually increase the opening of the thirteenth cryogenic valve CV13, and slowly close the twelfth cryogenic valve CV12 to improve cold recovery.

[0107] Step S5, after the value of the sixth temperature sensor T6 stabilizes to 75K, open the first cryogenic valve CV01 and the fourth cryogenic valve CV04, which are controlled by the control integrated system to maintain stable operation of the system; at the same time, close the eleventh cryogenic valve CV11, open the tenth cryogenic valve CV10, and then open the seventh cryogenic valve CV07, the supercritical helium of 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 cryogenic valve CV07, and the opening of the seventh cryogenic valve CV07 is gradually and slowly increased, and the liquid helium of 4.5K@1.3 bar is prepared in the vertical test dewar 120, and flows through the negative pressure heat exchanger 140 with a small opening assignment, and then flows into the sixth cryogenic valve CV06 of the vertical test dewar 120, so as to cool the negative pressure heat exchanger 140.

[0108] Step S6, controlling the opening of the seventh cryogenic valve CV07 by controlling the integrated system so that the value of the 4.5 K liquid helium level gauge LT01 in the vertical test dewar 120 is 80%. At the same time, limiting the opening of the seventh cryogenic valve CV07 to a minimum opening of 10% to prevent overpressure in the pipeline, which may cause the bursting disc to burst and the safety valve to trip. At the same time, controlling the integrated system to control the output of the fluid contact DC power heater HT01 so that the value of the 4.5 K liquid helium level gauge LT01 is 90%, so as to prevent the refrigeration system 400 from outputting too much cold and excessive liquid helium from overflowing into the return gas pipeline.

[0109] Step S7, according to the requirements of the superconducting cavity vertical test, the control integrated system controls the value of the 4.5 K liquid helium level gauge LT01 to reach the required value and maintain the required time interval, and then conducts the superconducting cavity vertical test in the 4.5K temperature range. The required data of the first sensor VT01 and the second sensor VT02 are transmitted back to the control integrated system.

[0110] Step S8, turning on the 2K gas heater 510 of the superfluid helium acquisition system 500 and preheating for a second predetermined time, so that the temperature of the helium entering the superfluid helium decompression and cooling pump group 520 reaches above 270K.

[0111] It can be understood that the temperature of the helium entering the superfluid helium decompression and cooling pump group 520 is 270-300K, and the 2K gas heater is preheated for 10 minutes to fully heat the 2K gas heater 510.

[0112] Step S9, after the value of the 4.5 K liquid helium level gauge LT01 reaches 80%, the superfluid helium decompression and cooling pump group 520 and the 2K gas heater 510 in the superfluid helium acquisition system 500 are turned on, the seventh cryogenic valve CV07 is gradually closed, the eleventh cryogenic valve CV11 is closed, and the tenth cryogenic valve CV10 leading to the superfluid helium acquisition system 500 is slowly opened to monitor that the temperature of the helium entering the superfluid helium decompression and cooling pump group 520 is not less than 260 K. The sixth cryogenic valve CV06 that flows through the negative pressure heat exchanger 140 and then flows into the vertical test dewar 120 is gradually increased, and throttling and decompression are started to obtain 2K @ 0.03 bar superfluid helium.

[0113] Step S10, when the state of liquid helium in the vertical test dewar 120 changes from 4.5K @ 1.3 bar to superfluid helium of 2K @ 0.03bar, according to the requirements of the superconducting cavity vertical test, the gas flow passes through the negative pressure heat exchanger 140 and the sixth cryogenic valve CV06 and then flows into the vertical test dewar 120, and the value of the 2K superfluid helium level gauge LT02 is controlled to reach the required value and maintained at the required time interval to perform the 2K test.

[0114] Similarly, the minimum opening of the sixth cryogenic valve CV06 is limited to 10% to prevent overpressure in the pipeline, which may cause the bursting disc to explode and the safety valve to trip. At the same time, the output of the fluid contact DC power heater HT01 is controlled to make the value of the 2K superfluid helium level gauge 90% to prevent the refrigerator system 400 from outputting too much cold and excessive liquid helium from overflowing into the return air pipeline. After completing the above operations, the required time interval is maintained to carry out the superconducting cavity vertical test in the 2K temperature zone, and the required data of the first sensor VT01 and the second sensor VT02 are transmitted back to the control integrated system.

[0115] 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 the vertical test distribution valve box 110 and the vertical test Dewar 120 from delivering cold.

[0116] Step S12, turn on the fluid contact type DC power heater HT01, set it to about 80% of the full power, wait until the value of the 4.5 K liquid helium level gauge LT01 is 0, and then turn off the fluid contact type DC power heater HT01.

[0117] 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 arranged 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.

[0118] Step S14, open the switch valve PV01, the fifth normal temperature valve WV05 and the sixth normal temperature valve WV06 on the rewarming return air pipeline, input 300K normal temperature to the vertical test distribution valve box 110 and the vertical test Dewar 120, and accelerate the rewarming speed.

[0119] Step S15, when the values ​​of the first temperature sensor T1 to the ninth temperature sensor T9 of the vertical test distribution valve box 110 and the vertical test dewar 120 are close to normal temperature, close 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.

[0120] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 is connected to the vertical test distribution valve box and 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 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 line of the distribution and transmission system, the output end of the first air inlet pipeline 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, the input end of which 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 which is communicated with the inner cavity of the vertical test dewar.

3. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to claim 2, 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.

4. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to claim 2, 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.

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

6. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to any one of claims 1 to 4, 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.

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

8. The vertical testing platform for multi-temperature zones of liquid helium and superfluid helium according to any one of claims 1 to 4, characterized in that: The vertical test dewar is provided with a heater and / or a liquid level gauge.

9. 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 described in any one of claims 1 to 8.

10. A method for using a vertical testing system for multi-temperature zones of liquid helium and superfluid helium, 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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