Low-temperature valve box for superfluid helium low-temperature system and testing system and method of low-temperature valve box

Abstract

The invention relates to the technical field of accelerators, and provides a low-temperature valve box for a superfluid helium low-temperature system and a testing system and method.The valve box comprises a strain measurement assembly, a low-temperature valve box body, a liquid helium storage tank, a supporting assembly, a helium cold shield pipeline and a superfluid helium preparation pipeline, and the two ends of the helium cold shield pipeline and the two ends of the superfluid helium preparation pipeline are both installed on the supporting assembly; the helium cold shield pipeline and the superfluid helium preparation pipeline are respectively provided with a low-temperature valve, a pressure sensor and a temperature sensor; an inlet of the liquid helium storage tank is communicated with the superfluid helium preparation pipeline, an outlet of the liquid helium storage tank is connected with a storage tank gas return pipeline, the storage tank gas return pipeline is provided with a pressure sensor and installed on the supporting assembly, and the liquid helium storage tank is provided with a liquid level meter; the strain measurement assembly is arranged on the supporting assembly, and the heat leakage load of the low-temperature valve box in the 2K-300K working temperature area and the mechanical load-temperature response characteristic of the supporting assembly can be obtained through a liquid level meter on the liquid helium storage tank, a temperature sensor on the pipeline and the strain measurement assembly on the supporting assembly.

Description

Technical Field

[0001] The present invention relates to the technical field of accelerators, and particularly relates to a cryogenic valve box for a superfluid helium cryogenic system, and a test system and method therefor. Background Art

[0002] With the development of science and technology, especially the requirements in frontier scientific fields such as particle physics experiments and nuclear fusion research, higher requirements are put forward for large-scale superfluid helium cryogenic refrigeration systems that can provide extremely low temperature environments. These systems usually use high-purity (>99.999%) helium gas as the working medium, and achieve a low temperature environment below 2K through means such as throttling and pressure reduction. Due to their low cryogenic limit, they are usually used in superconducting accelerator technology to provide a stable low temperature environment for cold masses such as superconducting cavities and superconducting magnets, which are the core equipment.

[0003] Currently, the cryogenic transmission pipelines of large superconducting accelerators are relatively long. In multi-channel pipelines, the working pressures and temperatures of each cryogenic pipeline are different. During the long-distance transmission of cryogenic helium medium, the heat leakage index of the cryogenic pipeline and the mechanical strength of the support components need to be strictly controlled. Under the existing technology, the heat leakage at 80K - 300K under normal pressure has been measured, but the test results lack the heat leakage index of the cryogenic valve box at 2K - 300K under the working state. Moreover, there is currently a lack of relevant research on the measurement of the mechanical properties of the support components in the cryogenic distribution system. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a cryogenic valve box for a superfluid helium cryogenic system, and a test system and method therefor, which can obtain the heat leakage load of the cryogenic valve box and the mechanical load of the support components in the working temperature range of 2K - 300K, providing reliable data support for subsequent design, processing and manufacturing.

[0005] The present invention provides a cryogenic valve box for a superfluid helium cryogenic system, comprising: A cryogenic valve box body, one side of the cryogenic valve box body has a convex part protruding outward, and the cryogenic valve box body has a cryogenic valve box cold shield; A support component, located inside the cryogenic valve box body and arranged on the convex part; A first pipeline assembly, including a helium cold shield pipeline and a superfluid helium preparation pipeline. Both ends of the helium cold shield pipeline and both ends of the superfluid helium preparation pipeline are installed on the support component, and the helium cold shield pipeline is communicated with the cryogenic valve box cold shield. The helium cold shield pipeline and the superfluid helium preparation pipeline are both provided with cryogenic valves, pressure sensors and temperature sensors; A liquid helium storage tank, the inlet end of which is connected to the superfluid helium preparation pipeline through a storage tank inlet pipeline. A cryogenic valve is provided on the storage tank inlet pipeline. The outlet end of the liquid helium storage tank is connected to a storage tank return gas pipeline. A pressure sensor is provided on the storage tank return gas pipeline. The storage tank return gas pipeline is installed on the support assembly. A liquid level gauge is provided on the liquid helium storage tank; A cryogenic valve box vacuum acquisition device, connected to the cryogenic valve box body; A strain measurement assembly is provided on the support assembly, and the strain measurement assembly is used to measure the mechanical load of the support assembly.

[0006] According to a cryogenic valve box for a superfluid helium cryogenic system provided by the present invention, a flowmeter is provided on the superfluid helium preparation pipeline; The input end of the storage tank inlet pipeline is located on the outlet side of the flowmeter. The storage tank inlet pipeline has two output branches, and each output branch is provided with the cryogenic valve and a temperature sensor.

[0007] According to a cryogenic valve box for a superfluid helium cryogenic system provided by the present invention, a temperature sensor and / or a heater are provided on the liquid helium storage tank.

[0008] According to a cryogenic valve box for a superfluid helium cryogenic system provided by the present invention, safety relief devices are connected to both the helium cold shield pipeline and the superfluid helium preparation pipeline. The safety relief device includes a connecting pipeline, a safety valve and a bursting disc provided on the connecting pipeline. The connecting pipeline is communicated with a recovery and purification system, and the connecting pipeline is communicated with a displacement pump group through a normal temperature valve.

[0009] According to a cryogenic valve box for a superfluid helium cryogenic system provided by the present invention, a negative pressure protection and safety relief integrated device is connected to the storage tank return gas pipeline. 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 bursting disc; The negative pressure protection shell is used to communicate 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 provided on the negative pressure protection shell and is connected to the storage tank return gas pipeline. The second-stage safety valve and the bursting disc are sequentially communicated with the negative pressure protection shell, and the second-stage safety valve and the bursting disc are communicated with the atmosphere.

[0010] The present invention also provides a cryogenic valve box multi-temperature zone heat load and stress test system, including a refrigeration supply system, a distribution and transmission system and the cryogenic valve box for a superfluid helium cryogenic system according to any one of the above. The refrigeration supply system is connected to the support assembly through the distribution and transmission system. The refrigeration supply system, the distribution and transmission system and the first pipeline assembly are communicated to form a closed-loop circuit.

[0011] A low-temperature valve box multi-temperature zone heat load and stress test system provided by the present invention further includes a transfer and transition multi-channel pipeline, and the transfer and transition multi-channel pipeline includes: A transfer cold shield supply pipe, the input end of the transfer cold shield supply pipe is connected to the distribution and transmission system, and the output end of the transfer cold shield supply pipe is connected to the input end of the helium cold shield pipeline; A transfer cold shield return pipe, the input end of the transfer cold shield return pipe is connected to the output end of the helium cold shield pipeline, and the output end of the transfer cold shield return pipe is connected to the distribution and transmission system; A transfer 4.5K supply pipe, the input end of the transfer 4.5K supply pipe is connected to the distribution and transmission system, and the output end of the transfer 4.5K supply pipe is connected to the input end of the superfluid helium preparation pipeline; A transfer 2K return pipe, the input end of the transfer 2K return pipe is connected to the output end of the storage tank return pipeline, and the output end of the transfer 2K return pipe is connected to the distribution and transmission system; A coupler return pipe, the input end of the coupler return pipe is connected to the output end of the superfluid helium preparation pipeline, and the output end of the coupler return pipe is connected to the transfer 2K return pipe; Temperature sensors are provided on the transfer cold shield supply pipe, the transfer cold shield return pipe, the transfer 4.5K supply pipe, the transfer 2K return pipe, and the coupler return pipe.

[0012] In a low-temperature valve box multi-temperature zone heat load and stress test system provided by the present invention, a flow meter is provided on the transfer cold shield return pipe and / or the transfer 2K return pipe.

[0013] A low-temperature valve box multi-temperature zone heat load and stress test system provided by the present invention, the distribution and transmission system includes: A distribution and transmission component, including a cold shield supply pipeline, a cold shield return pipeline, a 4.5K intake pipeline, a 2K return pipeline, and a cooling return pipeline connected to the refrigeration supply system; The main distribution valve box includes a distribution valve box body, a distribution valve box vacuum acquisition device, and a second pipeline assembly disposed within the distribution valve box body. The second pipeline assembly includes a cold shield inlet pipeline, a cold shield return pipeline, a helium inlet pipeline, and a helium return pipeline. Low-temperature valves, pressure sensors, and temperature sensors are provided on the cold shield inlet pipeline, the cold shield return pipeline, the helium inlet pipeline, and the helium return pipeline. The cold shield supply pipeline is connected to the transfer cold shield supply pipeline through the cold shield inlet pipeline. The 4.5K inlet pipeline is connected to the transfer 4.5K supply pipeline through the helium inlet pipeline. The input end of the cold shield return pipeline is connected to the transfer cold shield return pipeline. The cold shield return pipeline has two output branches. One output branch is connected to the cold shield return pipeline through a low-temperature valve, and the other output branch is connected to the cooling return pipeline through a low-temperature valve. The input end of the helium return pipeline is connected to the transfer 2K return pipeline. The helium return pipeline has two output branches. One output branch is connected to the 2K return pipeline through a low-temperature valve, and the other output branch is connected to the cooling return pipeline through a low-temperature valve.

[0014] The present invention also provides a method for using a low-temperature valve box multi-temperature zone heat load and stress test system, including the following steps: Step S1: Use the low-temperature valve box vacuum acquisition device to evacuate the interlayer of the low-temperature valve box body and the interlayer of the distribution valve box body, so that the interlayer of the low-temperature valve box body and the interlayer of the distribution valve box body reach a preset vacuum state. Step S2: Open the low-temperature valves of the first pipeline assembly and the low-temperature valves of the distribution transmission system, and open the displacement pump group and the normal-temperature valves connected to the displacement pump group to evacuate the distribution transmission system and the first pipeline assembly. Step S3: Close the displacement pump group, open the switch valve on the rewarming supply pipeline of the distribution transmission system, and fill the pipeline with helium gas at 300K until it reaches a slightly positive pressure, and then let it stand for a certain period of time to complete one gas replacement process in the pipeline. Step S4: Open the low-temperature valves of the helium cold shield pipeline, and the refrigeration supply system supplies low-temperature gas to the helium cold shield pipeline through the distribution transmission system to cool the low-temperature valve box body. Step S5: Open the low-temperature valves of the superfluid helium preparation pipeline and the low-temperature valves of the storage tank inlet pipeline, and the refrigeration supply system supplies low-temperature gas to the superfluid helium preparation pipeline through the distribution transmission system. Step S6: When the liquid level measurement value of the liquid level gauge reaches the first threshold, close the low-temperature valves of the superfluid helium preparation pipeline and the low-temperature valves of the storage tank inlet pipeline, and obtain a plurality of first liquid level measurement values measured by the liquid level gauge within the first preset time period. Step S7: Obtain the heat leakage of the liquid helium storage tank based on the plurality of first liquid level measurement values. Step S8: Obtain the measurement data of the strain measurement component on the support component, and obtain the mechanical load of the support component based on the measurement data. Step S9: Open the superfluid helium acquisition system of the refrigeration supply system. After the liquid helium storage tank obtains 2K superfluid helium, obtain the heat leakage of the liquid helium storage tank based on the liquid level measurement value of the liquid level gauge, obtain the pipeline heat leakage based on the temperature sensor on the pipeline, and obtain the mechanical load of the support component based on the measurement data of the strain measurement component on the support component.

[0015] The cryogenic valve box and its test system for the superfluid helium cryogenic system provided by the present invention can provide a stable cryogenic environment in the temperature range of 2K to 300K by arranging a helium-cooled shield pipeline and a superfluid helium preparation pipeline in the cryogenic valve box body, and arranging cryogenic valves, pressure sensors, and temperature sensors on both the helium-cooled shield pipeline and the superfluid helium preparation pipeline. Thus, through the liquid level gauge on the liquid helium storage tank, the temperature sensor on the pipeline, and the strain measurement component on the support component, the heat leakage load of the cryogenic valve box and the mechanical load of the support component in the working temperature range of 2K to 300K can be obtained, and valuable data support can be provided for subsequent design, processing, and manufacturing, so as to improve the robustness of the superconducting system in different operating environments. Description of the Drawings

[0016] 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 use in 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, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic structural diagram of the multi-temperature zone heat load and stress test system provided by the present invention.

[0018] Figure 2 It is a schematic structural diagram at the cryogenic valve box for the superfluid helium cryogenic system provided by the present invention.

[0019] Figure 3 It is a schematic structural diagram of the refrigeration supply system provided by the present invention.

[0020] Figure 4 It is a schematic structural diagram of the distribution and transmission system provided by the present invention.

[0021] Figure 5 It is a schematic connection diagram of the cryogenic valve box and the main distribution valve box provided by the present invention.

[0022] Figure 6 It is a schematic installation position diagram of the stress measurement unit on the support component in the cryogenic valve box provided by the present invention.

[0023] Figure 7 One of the schematic structural diagrams of the transfer and transition multi-channel pipeline provided by the present invention.

[0024] Figure 8 Another schematic structural diagram of the transfer and transition multi-channel pipeline provided by the present invention.

[0025] Figure 9 Schematic installation diagram of the temperature sensor provided by the present invention. Detailed implementation manners

[0026] 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.

[0027] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is 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 on 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.

[0028] 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 "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 situations.

[0029] In the embodiments of the present invention, unless otherwise clearly specified 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" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0030] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" 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 expressions 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.

[0031] The following will describe Figures 1-9 the cryogenic valve box and test system for a superfluid helium cryogenic system of the present invention.

[0032] An embodiment of the first aspect of the present invention provides a cryogenic valve box for a superfluid helium cryogenic system, as Figure 1 and Figure 2 shown. The cryogenic valve box includes a strain measurement component, a cryogenic valve box body 110, a cryogenic valve box vacuum acquisition device, and a first pipeline component, a liquid helium storage tank 130, and a support component 140 arranged in the cryogenic valve box body 110. The cryogenic valve box body 110 has a cryogenic valve box cold shield 112, and one side of the cryogenic valve box body 110 has a convex portion protruding outward; the support component 140 is located in the cryogenic valve box body 110 and is arranged on the convex portion; the first pipeline component includes a helium cold shield pipeline 121 and a superfluid helium preparation pipeline 122. Both ends of the helium cold shield pipeline 121 and both ends of the superfluid helium preparation pipeline 122 pass through the support component 140, and the helium cold shield pipeline 121 is communicated with the cryogenic valve box cold shield 112. The helium cold shield pipeline 121 and the superfluid helium preparation pipeline 122 are both provided with cryogenic valves, pressure sensors, and temperature sensors; the inlet end of the liquid helium storage tank 130 is communicated with the superfluid helium preparation pipeline 122 through a storage tank inlet pipeline 123. The storage tank inlet pipeline 123 is provided with a cryogenic valve. The outlet end of the liquid helium storage tank 130 is connected with a storage tank return gas pipeline 124. The storage tank return gas pipeline 124 is provided with a pressure sensor. The storage tank return gas pipeline 124 passes through the support component 140. The liquid helium storage tank 130 is provided with a liquid level gauge; the cryogenic valve box vacuum acquisition device is connected to the cryogenic valve box body 110; the strain measurement component is arranged on the support component 140, and the strain measurement component is used to measure the mechanical load of the support component 140.

[0033] It is understandable that the low-temperature valve box vacuum acquisition device evacuates the interlayer of the low-temperature valve box body 110 and the interlayer of the distribution valve box body 240. The refrigeration supply system supplies low-temperature helium gas to the helium cooling screen pipeline 121 to cool down the low-temperature valve box cooling screen 112; then, the refrigeration supply system passes low-temperature helium gas into the superfluid helium preparation pipeline 122 and enters the liquid helium storage tank 130 through the storage tank inlet pipeline 123 to cool down the pipeline and the liquid helium storage tank. When the liquid level measurement value of the liquid level gauge on the liquid helium storage tank 130 reaches the first threshold, the low-temperature valves of the superfluid helium preparation pipeline 122 and the low-temperature valves of the storage tank inlet pipeline 123 are closed, and multiple first liquid level measurement values measured by the liquid level gauge within the first preset time period are obtained. Based on the multiple first liquid level measurement values, the heat leakage of the liquid helium storage tank 130 can be obtained; during the cooling process, the measurement data of the strain measurement component on the support assembly 140 is simultaneously obtained, and based on the measurement data, the heat load and stress value of the support assembly 140 can be obtained, so that the heat leakage load of the low-temperature valve box 100 and the mechanical load-temperature response characteristics of the support assembly 140 within the working temperature range of 4.5K to 300K can be obtained, providing valuable data support for subsequent design, processing, and manufacturing.

[0034] It should be noted that by opening the superfluid helium acquisition system 500, 2K superfluid helium is stored in the liquid helium storage tank 130, so that the heat leakage load of the low-temperature valve box 100 and the mechanical load of the support assembly 140 within the working temperature range of 2K to 300K can be obtained.

[0035] It should be noted that the function of the superfluid helium preparation pipeline 122 is that supercritical helium gas at 4.5K@3.5bar becomes liquid helium at 4.5K@1.3bar after passing through the throttle valve and is stored in the liquid helium storage tank 130. Due to thermal interference, the liquid helium in the liquid helium storage tank 130 evaporates into helium gas and returns from the storage tank return gas pipeline 124; when preparing superfluid helium at 2K@0.03bar, supercritical helium gas at 4.5K@3.5bar passes through the throttle valve to become superfluid helium at 2K@0.03bar, and the superfluid helium pressure reduction and cooling pump group 520 sucks away the 2K steam from the storage tank return gas pipeline 124.

[0036] The low-temperature valve box for the superfluid helium low-temperature system provided by the embodiment of the present invention can provide a stable low-temperature environment in the temperature range of 2K to 300K by arranging the helium cooling screen pipeline 121 and the superfluid helium preparation pipeline 122 in the low-temperature valve box body and setting low-temperature valves, pressure sensors, and temperature sensors on both the helium cooling screen pipeline 121 and the superfluid helium preparation pipeline 122. Thus, the heat leakage load of the low-temperature valve box 100 and the mechanical load of the support assembly 140 within the working temperature range of 2K to 300K can be obtained through the liquid level gauge on the liquid helium storage tank 130, the temperature sensors on the pipeline, and the strain measurement component on the support assembly 140, and further provide valuable data support for subsequent design, processing, and manufacturing to improve the robustness of the superconducting system in different operating environments.

[0037] As Figure 2 shown, in an embodiment of the present invention, the cryogenic valve box body 110 has a cuboid structure, and one side thereof protrudes outward to form a convex portion in a tubular structure, and the support assembly 140 is welded to the convex portion.

[0038] The cryogenic valve box body 110 has a double-layer structure, specifically including a cryogenic valve box vacuum jacket 111 and a cryogenic valve box cold shield 112 disposed within the cryogenic valve box vacuum jacket 111. The cryogenic valve box cold shield 112 is used to reduce the radiative heat leakage of the internal cold fluid to the ambient temperature; a cryogenic distribution vacuum interlayer is formed between the cryogenic valve box vacuum jacket 111 and the cryogenic valve box cold shield 112, and a second vacuum silicon VS02 is disposed in the cryogenic distribution vacuum interlayer. The second vacuum silicon VS02 is electrically connected to a vacuum monitor, and the second vacuum silicon VS02 is used to detect the vacuum state of the internal interlayer of the cryogenic valve box body 110.

[0039] Optionally, the cryogenic valve box cold shield 112 includes a cold shield plate and coiled pipes. The cold shield plate is concentric with the cryogenic valve box vacuum jacket 111 as a whole. Coiled pipes are attached to the cold shield plate, and the coiled pipes are communicated with a helium cold shield pipeline 121 for cooling the cold shield plate with a cold helium gas medium. Preferably, the coiled pipes and the cold shield plate are tightly attached together with buckles to reduce the contact thermal resistance.

[0040] Furthermore, as Figure 2 shown, a sixteenth temperature sensor T16 is arranged on the cryogenic valve box cold shield 112. The sixteenth temperature sensor T16 is used to judge the cooling state of the cryogenic valve box cold shield 112; preferably, the number of the sixteenth temperature sensors T16 can be multiple. In this embodiment, the cryogenic valve box vacuum jacket 111 and the cryogenic valve box cold shield 112 have a hexahedron structure. The cryogenic valve box vacuum jacket 111 has six panels, and the cryogenic valve box cold shield 112 has six cold shield surfaces that cooperate with the six panels. The number of the sixteenth temperature sensors T16 is six, and they are respectively arranged on the six cold shield surfaces.

[0041] In an embodiment of the present invention, as Figure 2 shown, the cryogenic valve box vacuum acquisition device includes a second gate valve BV02 connected to the top cover plate of the cryogenic valve box body 110, and a second vacuum pump group Pump2 located at the bottom foundation. The second gate valve BV02 is connected to the second vacuum pump group Pump2 through a flange. The second vacuum pump group Pump2 includes a first-stage fore-vacuum mechanical pump and a second-stage molecular pump.

[0042] In an embodiment of the present invention, the liquid helium storage tank 130 can adopt a slightly positive pressure liquid helium storage tank, and the slightly positive pressure liquid helium storage tank can be a storage tank capable of storing 4.5 K@1.3 bar liquid helium and 2 K@0.03 bar supercritical helium.

[0043] Optionally, there are two liquid level gauges for the liquid helium storage tank 130, namely the 4.5 K liquid helium level gauge LT01 and the 2 K superfluid helium level gauge LT02. The 4.5 K liquid helium level gauge LT01 and the 2 K superfluid helium level gauge LT02 are vertically inserted into the slightly positive pressure liquid helium storage tank. According to their different working environments, they measure the liquid levels of 4.5 K liquid helium and 2 K superfluid helium, and the 4.5 K liquid helium level gauge LT01 and the 2 K superfluid helium level gauge LT02 maintain the highest design accuracy within their respective applicable temperature ranges, that is, the 4.5 K liquid helium level gauge LT01 has higher accuracy at 4.5 K liquid helium, and the 2 K superfluid helium level gauge LT02 has higher accuracy at 2 K superfluid helium.

[0044] Furthermore, the liquid helium storage tank 130 is provided with temperature sensors; specifically, the liquid helium storage tank 130 is provided with an eighteenth temperature sensor T18 installed at the bottom, and the eighteenth temperature sensor T18 is a high-precision temperature sensor.

[0045] In this embodiment, the top of the liquid helium storage tank 130 has three openings. Two of the openings are connected to the storage tank inlet pipeline 123, and the other opening is connected to the storage tank return gas pipeline 124. A pressure extraction pipe is welded on the storage tank return gas pipeline 124, and the pressure extraction pipe is connected to an eleventh pressure sensor P11. The eleventh pressure sensor P11 includes a high-precision positive pressure sensor and a high-precision negative pressure sensor and is one for standby. According to different pressure ranges, it collects the internal pressure of the liquid helium storage tank 130; among them, when the eleventh pressure sensor P11 is a high-precision positive pressure sensor, it measures the pressure in the liquid helium state; when the eleventh pressure sensor P11 is a high-precision negative pressure sensor, it measures the pressure in the superfluid helium state.

[0046] In an embodiment of the present invention, the liquid helium storage tank 130 is provided with a heater, and the heater can be a fluid-contact DC power heater EH01 provided inside the liquid helium storage tank 130.

[0047] In an embodiment of the present invention, a seventh pressure sensor P7, a seventh temperature sensor T7, an eighth pressure sensor P8, an eighth temperature sensor T8, and a twelfth cryogenic valve CV12 are provided on the helium cold shield pipeline 121. The eighth pressure sensor P8 and the eighth temperature sensor T8 are located on the inlet side of the helium cold shield pipeline 121, the seventh pressure sensor P7 and the seventh temperature sensor T7 are located on the outlet side of the helium cold shield pipeline 121, and the twelfth cryogenic valve CV12 is located between the seventh temperature sensor T7 and the eighth temperature sensor T8.

[0048] A ninth pressure sensor P9, a ninth temperature sensor T9, a tenth pressure sensor P10, a tenth temperature sensor T10 and a thirteenth cryogenic valve CV13 are provided on the superfluid helium preparation pipeline 122. The ninth pressure sensor P9 and the ninth temperature sensor T9 are located on the inlet side of the superfluid helium preparation pipeline 122, the tenth pressure sensor P10 and the tenth temperature sensor T10 are located on the outlet side of the superfluid helium preparation pipeline 122, and the thirteenth cryogenic valve CV13 is located between the ninth temperature sensor T9 and the tenth temperature sensor T10.

[0049] Among them, the seventh temperature sensor T7, the eighth temperature sensor T8, the ninth temperature sensor T9, and the tenth temperature sensor T10 are high-precision temperature sensors. The high-precision temperature sensor has two sensors, one for standby; the seventh pressure sensor P7, the eighth pressure sensor P8, the ninth pressure sensor P9, and the tenth pressure sensor P10 are high-precision positive pressure sensors.

[0050] Optionally, a flowmeter is provided on the superfluid helium preparation pipeline 122. The flowmeter is a mass flowmeter, which is denoted as the first flowmeter FL01. The first flowmeter FL01 is a cryogenic flowmeter. The first flowmeter FL01 is located between the ninth temperature sensor T9 and the thirteenth cryogenic valve CV13. The input end of the storage tank inlet pipeline 123 is connected to the pipeline between the first flowmeter FL01 and the thirteenth cryogenic valve CV13. The storage tank inlet pipeline 123 has two output branches, and each output branch is provided with a cryogenic valve and a temperature sensor; specifically, one output branch of the storage tank inlet pipeline 123 is provided with a fourteenth cryogenic valve CV14 and a fifth temperature sensor T5, and the other output branch is provided with a fifteenth cryogenic valve CV15 and a sixth temperature sensor T6; among them, the fifth temperature sensor T5 and the sixth temperature sensor T6 are high-precision temperature sensors. The high-precision temperature sensor has two sensors, one for standby. Preferably, the fifth temperature sensor T5 and the sixth temperature sensor T6 are close to the inlet of the liquid helium storage tank 130 to avoid errors caused by the throttling effect. The fifth temperature sensor T5 and the sixth temperature sensor T6 can effectively judge the state of the helium reaching the slightly positive pressure liquid helium storage tank.

[0051] It can be understood that the refrigeration supply system sends 4.5 K supercritical helium gas into the superfluid helium preparation pipeline 122. After the 4.5 K supercritical helium gas flows through the first flowmeter FL01, it is divided into two branch pipelines, and the two branch pipelines are respectively connected to the fourteenth cryogenic valve CV14 and the fifteenth cryogenic valve CV15. The 4.5 K high-pressure helium gas is throttled into 4.5 K @ 1.3 bar liquid helium and stored in the slightly positive pressure liquid helium storage tank.

[0052] The refrigeration supply system allows helium gas at 50 K@4 bar to flow into the input end of the helium cold shield pipeline 121, pass through the coiled pipes attached to the cold shield plate, and is controlled by the twelfth cryogenic valve CV12. The value of the seventh temperature sensor T7 is continuously monitored within the design requirements. Finally, the helium gas returns to the refrigeration supply system via the output end of the helium cold shield pipeline 121.

[0053] In one embodiment of the present invention, as Figure 2 shown, the safety relief device includes a connecting pipeline, as well as a safety valve and a rupture disc provided on the connecting pipeline.

[0054] Specifically, the superfluid helium preparation pipeline 122 is connected to a first safety relief device. The first safety relief device includes a third connecting pipeline, as well as a third safety valve SV03 and a third rupture disc BP03 provided on the third connecting pipeline. One end of the third connecting pipeline communicates with the pipeline between the tenth temperature sensor T10 and the thirteenth cryogenic valve CV13. The other end of the third connecting pipeline communicates with the recovery and purification system 600. The third safety valve SV03 and the third rupture disc BP03 are located outside the cryogenic valve box body 110. The third connecting pipeline is connected to the displacement pump group Pump3 through the sixth normal temperature valve WV06; among them, the third rupture disc BP03 is connected to the atmosphere.

[0055] The helium cold shield pipeline 121 is connected to a second safety relief device. The second safety relief device includes a fifth connecting pipeline, as well as a fifth safety valve SV05 and a fifth rupture disc BP05 provided on the fifth connecting pipeline. One end of the fifth connecting pipeline communicates with the pipeline between the seventh temperature sensor T7 and the twelfth cryogenic valve CV12. The other end of the fifth connecting pipeline communicates with the recovery and purification system 600. The fifth safety valve SV05 and the fifth rupture disc BP05 are located outside the cryogenic valve box body 110. The fifth connecting pipeline is connected to the displacement pump group Pump3 through the eighth normal temperature valve WV08; among them, the fifth rupture disc BP05 is connected to the atmosphere.

[0056] Furthermore, the superfluid helium preparation pipeline 122 is connected to a third safety relief device. The third safety relief device includes a sixth connecting pipeline, as well as a sixth safety valve SV06 and a sixth rupture disc BP06 provided on the sixth connecting pipeline. One end of the sixth connecting pipeline communicates with the pipeline between the ninth temperature sensor T9 and the first flowmeter FL01. The other end of the sixth connecting pipeline communicates with the recovery and purification system 600. The sixth safety valve SV06 and the sixth rupture disc BP06 are located outside the cryogenic valve box body 110; among them, the sixth rupture disc BP06 is connected to the atmosphere. Preferably, a second one-way valve VN02 is provided at the end of the sixth connecting pipeline connecting to the superfluid helium preparation pipeline 122. The second one-way valve VN02 prevents the abnormal opening of the sixth safety valve SV06 and the sixth rupture disc BP06 caused by the pressure oscillation due to the thermoacoustic oscillation effect.

[0057] In one embodiment of the present invention, a negative pressure protection and safety relief integrated device is connected to the storage tank return gas pipeline 124. 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 bursting disc; the negative pressure protection shell is respectively communicated with the low-pressure branch 230 of the distribution and transmission system 200, the displacement pump group Pump3, and the recovery and purification system 600; the first-stage safety valve is arranged inside the negative pressure protection shell and is connected to the storage tank return gas pipeline 124, and the second-stage safety valve and the bursting disc are sequentially communicated with the negative pressure protection shell, and the second-stage safety valve is communicated with the atmosphere.

[0058] Specifically, a first negative pressure protection and safety relief integrated device is connected to the storage tank return gas pipeline 124. The first negative pressure protection and safety relief integrated device includes a fourth connection pipeline, a first negative pressure protection shell, a first-stage fourth safety valve SV04-1 (i.e., the first-stage safety valve), a second-stage fourth safety valve SV04-2 (i.e., the second-stage safety valve), and a fourth bursting disc BP04. One end of the fourth connection pipeline is communicated with the storage tank return gas pipeline 124, and the other end of the fourth connection pipeline is connected to the first-stage fourth safety valve SV04-1. The first-stage fourth safety valve SV04-1 is integrated in the first negative pressure protection shell. The first negative pressure protection shell is communicated with the recovery and purification system 600. The displacement gas outlet of the first negative pressure protection shell is connected to the displacement pump group Pump3 through a ninth normal temperature valve WV09. The air inlet of the first negative pressure protection shell is communicated with the low-pressure branch 230 of the refrigeration supply system. The exhaust port of the first negative pressure protection shell is connected with a second-stage fourth safety valve SV04-2 and a fourth bursting disc BP04 arranged in sequence, and the second-stage fourth safety valve SV04-2 and the fourth bursting disc BP04 are communicated with the atmosphere.

[0059] It can be understood that the sixth normal temperature valve WV06, the seventh normal temperature valve WV07, and the eighth normal temperature valve WV08 on the helium cold shield pipeline 121, the superfluid helium preparation pipeline 122, and the storage tank return gas pipeline 124 are connected to the displacement pump group Pump3 and are used to displace the helium environment in the internal pipeline of the cryogenic valve box 100, and the ninth normal temperature valve WV09 is used to displace the internal environment of the first negative pressure protection shell.

[0060] It should be noted that the first-stage fourth safety valve SV04-1 led out from the return gas pipeline 124 of the storage tank is encapsulated in the first negative pressure protection shell, and the 300 K@1.05 bar slightly positive pressure helium gas coming from the low-pressure line of the refrigeration supply system is sent to the first negative pressure protection shell in real time. Even if the first-stage fourth safety valve SV04-1 leaks, the slightly positive pressure helium environment in the first negative pressure protection shell can prevent air pollution in the entire refrigeration system. In addition, when sudden overpressure occurs due to water and power outages and accidents in the refrigeration supply system, the first-stage fourth safety valve SV04-1 can jump in time to send helium gas to the recovery and purification system 600. When the pressure is too high and the first-stage fourth safety valve SV04-1 cannot relieve the pressure in time, the fourth rupture disc BP04 can burst to relieve the pressure in time.

[0061] An embodiment of the second aspect of the present invention provides a multi-temperature zone heat load and stress test system, as Figures 1 to 4 shown. The system includes a refrigeration supply system, a distribution and transmission system 200, and the cryogenic valve box 100 for the superfluid helium cryogenic system provided in any of the above embodiments; the refrigeration supply system is connected to the support assembly 140 through the distribution and transmission system 200, and the refrigeration supply system, the distribution and transmission system 200, and the first pipeline assembly are connected to form a closed-loop circuit.

[0062] It can be understood that the refrigeration supply system can provide specific pressure, temperature, and flow rate through the distribution and transmission system 200 to test the thermodynamic performance of the cryogenic valve box 100; the test system can provide different required cooling rates, combined with specific pressure, temperature, and flow rate, to obtain the mechanical performance of the key support components of the cryogenic valve box 100 and the accurate heat leakage data of the cryogenic pipeline; the test system can realize rapid repeated temperature reduction by controlling the pressure and flow rate to obtain the fatigue data of materials at different cooling rates, which helps to provide key data for the cooling rate of large scientific cryogenic systems; after the cryogenic valve box 100 obtains the above key data, it can be coupled with the refrigeration supply system for research to provide key strategies for dealing with different cooling requirements.

[0063] Specifically, the test system further includes a recovery and purification system 600. The refrigeration supply system includes a helium storage system 300, a refrigeration machine system 400, and a superfluid helium acquisition system 500. The helium storage system 300 is connected to the refrigeration machine system 400, the refrigeration machine system 400 is connected to the cryogenic valve box 100 through the distribution and transmission system 200, the cryogenic valve box 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 end of the refrigeration machine system 400, and the cryogenic valve box 100 is connected to the refrigeration machine system 400 through the recovery and purification system 600.

[0064] Optionally, the helium storage system 300 is a high-pressure storage tank container, and the helium storage system 300 contains the necessary helium for the operation of the entire system, for example, high-purity helium with an absolute pressure of 8 to 10 bar is stored therein.

[0065] The helium storage system 300 is connected to the refrigerator system 400 through the pipelines of the high-pressure circuit and the low-pressure circuit. In order to adjust the pressure state of the refrigerator system 400 and ensure that it has the necessary helium reserve, the helium storage system 300 can perform the operation of charging or depressurizing the high-pressure circuit and the low-pressure circuit of the refrigerator system. In this way, the pressure stability of the refrigerator system 400 during operation can be maintained, ensuring its normal operation while meeting the requirements of helium reserve.

[0066] The multi-temperature zone heat load and stress testing system provided in the embodiment of the present invention provides a closed loop for large-scale helium cryogenic cycle testing for the cryogenic valve box 100 through a helium storage system, a refrigerator system, a distribution and transmission system, a transfer transition multi-channel pipeline, a superfluid helium acquisition system, and a recovery and purification system. It can provide a pressure range from normal pressure to 13 bar, and a variety of pressure intervals and multi-temperature zone research conditions in the temperature range of 2K to 300K according to the design requirements of the cryogenic valve box, and can collect data in real time through a strain measurement component to provide multi-physical field experimental data of the cryogenic valve box under the design conditions, provide high-precision research data for the entire large-scale helium cryogenic cycle refrigeration system it serves, and provide data support for the design of similar structures.

[0067] like Figure 3 As shown, the refrigerator system 400 is a Kraut cycle refrigeration liquefaction device composed 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, oil removal and drying components 420, and refrigerator cold box 430, wherein the helium compressor can compress low-pressure helium of 1.05 bar to 13 bar to provide the original pressure head, and the oil removal and drying component 420 removes the lubricating oil mist in the high-pressure helium, and a small amount of H2O, N2, H2 and C x H y The molecules are removed and dried before being sent to the refrigerator cold box 430 to complete the Kraut cycle. The refrigerator cold box 430 includes various levels of heat exchangers, turbines, throttle valves and other equipment to expand and cool the high-pressure helium at 300 K@13 bar to supercritical helium at 4.5 K@3.5 bar.

[0068] The superfluid helium acquisition system 500 is a set of decompression and cooling equipment, including a 2K gas heater 510 and a superfluid helium decompression and cooling pump set 520; among them, the 2K gas heater 510 is an 18kW AC heater, which is used to heat the future 2K gas to above 250K to ensure the normal operation of the superfluid helium decompression and cooling pump set 520; the superfluid helium decompression and cooling pump set 520 includes four sets of 8 pump sets, and each set of pump sets includes a primary mechanical pump and a secondary fore pump, which can provide a decompression capacity of 2g / s at 2K@3000Pa under the rated power.

[0069] The recovery and purification system 600 is a device for recovering and purifying helium. When the system encounters a water or power outage or the internal pressure of the pipeline suddenly exceeds the pressure, the safety valve jumps, and the helium is sent into the recovery and purification system, and further sent to the helium storage system.

[0070] In an embodiment of the present invention, as Figure 1 and Figure 2 shown, the test system further includes a transfer and transition multi-channel pipeline 700. The distribution and transmission system 200 is connected to the cryogenic valve box 100 through the transfer and transition multi-channel pipeline 700 to form a closed loop.

[0071] Specifically, the transfer and transition multi-channel pipeline 700 includes a transfer cold shield supply pipe 710, a transfer cold shield return pipe 720, a transfer 4.5K supply pipe 730, a transfer 2K return pipe 740, and a coupler return pipe 750; the input end of the transfer cold shield supply pipe 710 is connected to the distribution and transmission system 200, and the output end of the transfer cold shield supply pipe 710 is connected to the input end of the helium cold shield pipeline 121; the input end of the transfer cold shield return pipe 720 is connected to the output end of the helium cold shield pipeline 121, and the output end of the transfer cold shield return pipe 720 is connected to the distribution and transmission system 200; the input end of the transfer 4.5K supply pipe 730 is connected to the distribution and transmission system 200, and the output end of the transfer 4.5K supply pipe 730 is connected to the input end of the superfluid helium preparation pipeline 122; the input end of the transfer 2K return pipe 740 is connected to the output end of the storage tank return pipeline 124, and the output end of the transfer 2K return pipe 740 is connected to the distribution and transmission system 200; the input end of the coupler return pipe 750 is connected to the output end of the superfluid helium preparation pipeline 122, and the output end of the coupler return pipe 750 is connected to the transfer 2K return pipe 740; temperature sensors are provided on the transfer cold shield supply pipe 710, the transfer cold shield return pipe 720, the transfer 4.5K supply pipe 730, and the transfer 2K return pipe 740.

[0072] Furthermore, a flowmeter is provided on the transfer cold shield return pipe 720 and / or the transfer 2K return pipe 740.

[0073] For example, a twelfth temperature sensor T12 is provided on the transfer cold shield gas supply pipe 710, an eleventh temperature sensor T11 and a second flowmeter FL02 are provided on the transfer cold shield gas return pipe 720, a thirteenth temperature sensor T13 is provided on the transfer 4.5K gas supply pipe 730, a fifteenth temperature sensor T15 and a third flowmeter FL03 are provided on the transfer 2K gas return pipe 740, a fourteenth temperature sensor T14 is provided on the coupler gas return pipe 750, and the coupler gas return pipe 750 is connected to the pipeline between the fifteenth temperature sensor T15 and the third flowmeter FL03. Among them, the eleventh temperature sensor T11, the twelfth temperature sensor T12, the thirteenth temperature sensor T13, the fourteenth temperature sensor T14, and the fifteenth temperature sensor T15 are all high-precision temperature sensors. The high-precision temperature sensor has two sensors, one for standby; the second flowmeter FL02 and the third flowmeter FL03 are Venturi flowmeters.

[0074] In an embodiment of the present invention, as Figure 4 shown, the distribution and transmission system 200 includes a distribution and transmission component 210 and a main distribution valve box; as Figure 5 shown, the main distribution valve box is connected to the refrigeration system 400 through a multi-channel pipeline, and undertakes the flow distribution, pressure regulation and return gas closed-loop of all low-temperature gas supply.

[0075] The distribution and transmission component 210 includes a multi-channel transmission pipeline connected to the refrigeration supply system, a normal temperature pipeline 220 and a low-pressure branch. The multi-channel transmission pipeline includes a cold shield gas supply pipeline 211, a cold shield gas return pipeline 212, a 4.5K intake pipeline 213, and a 2K return pipeline 214. The normal temperature pipeline 220 includes a cooling return gas pipeline 221.

[0076] The main distribution valve box includes a distribution valve box body 240, a distribution valve box vacuum acquisition device, and a second pipeline assembly disposed within the distribution valve box body 240. The second pipeline assembly includes a cold shield inlet pipeline 243, a cold shield return pipeline 244, a helium inlet pipeline 245, and a helium return pipeline 246. Low-temperature valves, pressure sensors, and temperature sensors are provided on the cold shield inlet pipeline 243, the cold shield return pipeline 244, the helium inlet pipeline 245, and the helium return pipeline 246; the cold shield gas supply pipeline 211 is connected to the transfer cold shield gas supply pipe 710 through the cold shield inlet pipeline 243; the 4.5K inlet pipeline 213 is connected to the transfer 4.5K gas supply pipe 730 through the helium inlet pipeline 245; the input end of the cold shield return pipeline 244 is connected to the transfer cold shield return pipe 720, and the cold shield return pipeline 244 has two output branches. One output branch is connected to the cold shield return pipeline 212 through a low-temperature valve, and the other output branch is connected to the temperature reduction return pipeline 221 through a low-temperature valve; the input end of the helium return pipeline 246 is connected to the transfer 2K return pipe 740, and the helium return pipeline 246 has two output branches. One output branch is connected to the 2K return pipeline 214 through a low-temperature valve, and the other output branch is connected to the temperature reduction return pipeline 221 through a low-temperature valve.

[0077] Specifically, one end of the cold shield gas supply pipeline 211 is 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 inlet pipeline 243, the output end of the cold shield inlet pipeline 243 is connected to the input end of the transfer cold shield gas supply pipe 710, and a seventh low-temperature valve CV07, a third temperature sensor T3, and a third pressure sensor P3 located within the distribution valve box body 240 are provided on the cold shield inlet pipeline 243. The seventh low-temperature valve CV07, the third temperature sensor T3, and the third pressure sensor P3 are arranged in sequence along the flow direction of the helium medium.

[0078] One end of the 4.5K inlet pipeline 213 is connected to the refrigerator cold box 430, the other end of the 4.5K inlet pipeline 213 is connected to the input end of the helium inlet pipeline 245, the output end of the helium inlet pipeline 245 is connected to the input end of the transfer 4.5K gas supply pipe 730. The helium inlet pipeline 245 is a 4.5K inlet pipeline, and a sixth low-temperature valve CV06, a second temperature sensor T2, and a second pressure sensor P2 are provided on the 4.5K inlet pipeline. The sixth low-temperature valve CV06, the second temperature sensor T2, and the second pressure sensor P2 are arranged in sequence along the flow direction of the helium medium.

[0079] Furthermore, the normal-temperature pipeline 220 further includes a rewarming gas supply pipeline 222 connected to the cold box 430 of the refrigerator. A first mixer Mix1 is also provided on the 4.5K gas inlet pipeline. The first mixer Mix1 is located between the sixth cryogenic valve CV06 and the second temperature sensor T2. The first mixer Mix1 is connected to the rewarming gas supply pipeline 222 through the rewarming gas supply pipeline, and the rewarming gas supply pipeline is provided with a second normal-temperature valve WV02.

[0080] A second mixer Mix2 is also provided on the cold shield gas inlet pipeline 243. The second mixer Mix2 is located between the seventh cryogenic valve CV07 and the third temperature sensor T3. The second mixer Mix2 is connected to the rewarming gas supply pipeline through the first normal-temperature valve WV01, wherein the first normal-temperature valve WV01 and the second normal-temperature valve WV02 are in parallel. Preferably, a sixth pressure sensor P6 is provided on the rewarming gas supply pipeline, and the sixth pressure sensor P6 is a high-precision positive pressure sensor.

[0081] Furthermore, a first check valve VN01 is provided on the pipeline between the first mixer Mix1 and the second normal-temperature valve WV02. The first check valve VN01 can prevent gas from flowing back and can prevent thermoacoustic oscillations below the 4.5K temperature region, which can ensure that the system will not accidentally trigger the safety valve and rupture disc under unexpected pressure conditions, thereby avoiding unnecessary activation of the safety valve and rupture disc caused by incorrect pressure and ensuring the stable and safe operation of the system.

[0082] Optionally, one end of the cold shield gas return pipeline 212 is connected to the cold box 430 of the refrigerator, and the other end of the cold shield gas return pipeline 212 is connected to the output end of the cold shield gas return pipeline 244. The cold shield gas return pipeline 244 is provided with an eighth cryogenic valve CV08, a fourth temperature sensor T4, and a fourth pressure sensor P4 located in the distribution valve box body 240. The fourth pressure sensor P4, the fourth temperature sensor T4, and the eighth cryogenic valve CV08 are arranged in sequence along the flow direction of the helium medium; the pipeline between the eighth cryogenic valve CV08 and the fourth temperature sensor T4 is connected to the cooling gas return pipeline 221 through a ninth cryogenic valve CV09, that is, the cold shield gas return pipeline 244 has two output branches, one of which is connected to the cold shield gas return pipeline 212 through the eighth cryogenic valve CV08, and the other output branch is connected to the cooling gas return pipeline 221 through the ninth cryogenic valve CV09.

[0083] One end of the 2K return gas pipeline 214 is connected to the superfluid helium acquisition system 500, and the other end of the 2K return gas pipeline 214 is connected to the output end of the helium return gas pipeline 246. The input end of the helium return gas pipeline 246 is connected to the output end of the transfer 2K return gas pipe 740. An eleventh cryogenic valve CV11, a first temperature sensor T1, and a first pressure sensor P1 are provided on the helium return gas pipeline 246. The first pressure sensor P1, the first temperature sensor T1, and the eleventh cryogenic valve CV11 are arranged in sequence along the flow direction of the helium medium. The pipeline between the first temperature sensor T1 and the eleventh cryogenic valve CV11 is connected to the cooling return gas pipeline 221 through a tenth cryogenic valve CV10. That is, the helium return gas pipeline 246 has two output branches. One output branch is connected to the 2K return gas pipeline 214 through the eleventh cryogenic valve CV11, and the other output branch is connected to the cooling return gas pipeline 221 through the tenth cryogenic valve CV10.

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

[0085] It can be understood that the refrigerator system 400 sends supercritical helium gas at 4.5 K@3.5 bar into the distribution valve box body 240 through the 4.5K intake pipeline 213. After passing through the sixth cryogenic valve CV06 and the first mixer Mix1, the supercritical helium gas at 4.5K@3.5 bar is sent into the transfer 4.5K supply pipe 730, and then sent into the superfluid helium preparation pipeline 122 in the cryogenic valve box 100.

[0086] The refrigerator system 400 sends helium gas at 50 K@4 bar into the distribution valve box body 240 through the cold shield supply pipeline 211. After passing through the seventh cryogenic valve CV07 and the second mixer Mix2, the 50K helium gas is sent into the transfer cold shield supply pipe 710, and then sent into the cryogenic valve box 100.

[0087] The helium gas returning from the helium cold shield pipeline 121 in the cryogenic valve box 100 returns to the refrigerator system 400 through the transfer cold shield return pipe 720 and the eighth cryogenic valve CV08, and the helium gas returning from the helium cold shield pipeline 121 in the cryogenic valve box 100 returns to the refrigerator system 400 through the transfer cold shield return pipe 720 and the ninth cryogenic valve CV09; the 4.5K helium gas returning from the superfluid helium preparation pipeline 122 and the storage tank return pipeline 124 in the cryogenic valve box 100 returns to the refrigerator system 400 through the tenth cryogenic valve CV10 and the cooling return gas pipeline 221; and when the superfluid helium acquisition system 500 is opened, the 2K return gas can return to the refrigerator system 400 via the eleventh cryogenic valve CV11 and the 2K return gas pipeline 214.

[0088] Optionally, the output pipelines of the ninth cryogenic valve CV09 and the tenth cryogenic valve CV10 are connected within the distribution valve box body 240 and communicate with the cooling return gas pipeline 221 through the cooling return gas pipeline 247. Preferably, a fifth pressure sensor P5 located within the distribution valve box body 240 is provided on the cooling return gas pipeline 247; the fifth pressure sensor P5 is a high-precision positive pressure sensor.

[0089] It can be understood that the eighth cryogenic valve CV08 and the ninth cryogenic valve CV09 are in parallel, the tenth cryogenic valve CV10 and the eleventh cryogenic valve CV11 are in parallel, and the ninth cryogenic valve CV09 and the tenth cryogenic valve CV10 are in parallel, which can form all the circuits for gas return under different working conditions, so as to realize the cryogenic test environment at different working conditions, in the 4.5K and 2K temperature zones; the saturated helium gas at 4.5K or 2K in the cryogenic valve box 100 returns to the refrigerator system 400 via the tenth cryogenic valve CV10 or the eleventh cryogenic valve CV11.

[0090] In this embodiment, the first temperature sensor T1, the second temperature sensor T2, the third temperature sensor T3, and the fourth temperature sensor T4 are all high-precision temperature sensors, and the high-precision temperature sensor has two sensors with one in reserve; the first pressure sensor P1 is a high-precision positive pressure sensor and a high-precision negative pressure sensor with one in reserve; the second pressure sensor P2, the third pressure sensor P3, and the fourth pressure sensor P4 are high-precision positive pressure sensors.

[0091] Further, a first cryogenic valve CV01 is provided at one end of the 4.5K intake pipeline 213 close to the refrigerator cold box 430, a second cryogenic valve CV02 is provided at one end of the cold shield gas supply pipeline 211 close to the refrigerator cold box 430, a third cryogenic valve CV03 is provided at one end of the cold shield gas return 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, a fifth cryogenic valve CV05 is provided at one end of the low-pressure branch 230 close to the refrigerator cold box 430, and a switching valve PV01 is provided at one end of the rewarming gas supply pipeline 222 close to the refrigerator cold box 430.

[0092] In an embodiment of the present invention, as Figure 4As shown, the helium return pipeline 246 is connected to a second negative pressure protection and safety relief integrated device. The second negative pressure protection and safety relief integrated device includes a first connection pipeline, a second negative pressure protection shell, a first-stage first safety valve SV01-1 (i.e., the first-stage safety valve), a second-stage first safety valve SV01-2 (i.e., the second-stage safety valve), and a first rupture disc BP01. One end of the first connection pipeline communicates with the inlet side of the first pressure sensor P1, and the other end of the first connection pipeline is connected to the first-stage first safety valve SV01-1. The first-stage first safety valve SV01-1 is integrated in the second negative pressure protection shell, and the second negative pressure protection shell communicates with the recovery and purification system 600. The replacement gas outlet of the second negative pressure protection shell is connected to the replacement pump group Pump3 through the fifth normal temperature valve WV05. The inlet of the second negative pressure protection shell communicates with the low-pressure branch 230 of the refrigeration supply system. The exhaust port of the second negative pressure protection shell is connected with the second-stage first safety valve SV01-2 and the first rupture disc BP01 arranged in sequence, and the second-stage first safety valve SV01-2 and the first rupture disc BP01 communicate with the atmosphere.

[0093] The cold shield return pipeline 244 is connected to a fourth safety relief device. The fourth safety relief device includes a second connection pipeline and a second safety valve SV02 and a second rupture disc BP02 arranged on the second connection pipeline. One end of the second connection pipeline communicates with the inlet side of the fourth pressure sensor P4, and the other end of the second connection pipeline communicates with the recovery and purification system 600. The second safety valve SV02 and the second rupture disc BP02 are located outside the distribution valve box body 240, and the second connection pipeline communicates with the replacement pump group Pump3 through the fourth normal temperature valve WV04.

[0094] In an embodiment of the present invention, the distribution valve box body 240 is a double-layer structure, specifically including a distribution valve box vacuum cover 241 and a distribution valve box cold shield 242 arranged inside the distribution valve box vacuum cover 241. The distribution valve box cold shield 242 is used to reduce the radiative heat leakage of the internal cold fluid to the ambient temperature; a distribution vacuum interlayer is formed between the distribution valve box vacuum cover 241 and the distribution valve box cold shield 242, and a first vacuum silicon VS01 is arranged in the distribution vacuum interlayer. The first vacuum silicon VS01 is electrically connected to the vacuum monitor, and the first vacuum silicon VS01 is used to detect the vacuum state of the internal interlayer of the distribution valve box body 240.

[0095] Optionally, the distribution valve box cold shield 242 can adopt the same structure as the low-temperature valve box cold shield 112, including a cold shield plate and a coiled pipe. The cold shield plate is concentric with the distribution valve box vacuum cover as a whole, and the coiled pipe is attached to the cold shield plate. The coiled pipe communicates with the cold shield inlet pipeline 243 and the cold shield return pipeline 244, and is used to cool the cold shield plate with cold helium gas medium.

[0096] Further, a seventeenth temperature sensor 17 is arranged on the cold shield 242 of the distribution valve box, and the seventeenth temperature sensor 17 is used to judge the cooling state of the cold shield 242 of the distribution valve box; preferably, the number of the seventeenth temperature sensors 17 can be multiple. In this embodiment, the distribution valve box vacuum cover 241 and the cold shield 242 of the distribution valve box are hexahedron structures. The distribution valve box vacuum cover 241 has six panels, and the cold shield 242 of the distribution valve box has six cold shield surfaces that cooperate with the six panels. The number of the seventeenth temperature sensors is six, which are respectively arranged on the six cold shield surfaces.

[0097] In an embodiment of the present invention, the distribution valve box vacuum acquisition device includes a first gate valve BV01 connected to the top cover plate of the distribution valve box body 240, and a first vacuum pump group Pump1 located at the bottom 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 first-stage fore vacuum pump and a second-stage molecular pump.

[0098] In an embodiment of the present invention, the test system further includes a control integration system. The control integration system is electrically connected to all temperature sensors, high-precision positive pressure sensors, high-precision negative pressure sensors, 4.5 K liquid helium level gauge LT01, 2 K superfluid helium level gauge LT02, fluid contact type DC power heater EH01, cryogenic valves, flow meters, normal temperature valves, gate valves, cryogenic valve box vacuum acquisition devices, distribution valve box vacuum acquisition devices, displacement pump group Pump3, strain measurement components and controllers. The control integration system includes the automatic control of the controller and the data acquisition unit of various sensors. Among them, the thirteenth cryogenic valve CV13, the fourteenth cryogenic valve CV14 and the fifth cryogenic valve CV15 are pneumatic Joule-Thomson throttle valves (J-T valves), and the remaining cryogenic valves are cryogenic pneumatic valves; the normal temperature valves are normal temperature pneumatic valves.

[0099] In an embodiment of the present invention, as Figure 6 shown, the support assembly 140 is used for fixing the first pipeline assembly in the cryogenic valve box 100. The strain measurement component on the support assembly 140 includes multiple temperature sensors and multiple strain gauges. The number of strain gauges is equal to the number of temperature sensors on the support assembly 140, and the positions correspond one by one; taking one strain gauge and one temperature sensor as a strain measurement unit 141, then the strain measurement component includes multiple strain measurement units 141. In this embodiment, the strain measurement unit 141 is a high-fidelity strain measurement sensor, and each high-fidelity strain measurement sensor includes a 3-axis strain gauge and a high-precision temperature sensor.

[0100] In an embodiment of the present invention, as Figure 7As shown, the transfer and transition multi-channel pipeline 700 is used to connect the main distribution valve box and the cryogenic valve box 100. The transfer and transition multi-channel pipeline 700 has a transfer vacuum chamber 705. The first side of the transfer vacuum chamber 705 has a main distribution connection flange 701, and the main distribution connection flange 701 is used to connect with the main distribution valve box; a perforating tooling 704 is arranged on the main distribution connection flange 701, and the perforating tooling 704 is a pressure inlet and outlet pipe perforating tooling for a Venturi flowmeter. A vacuum connector 702 is arranged on the first side of the transfer vacuum chamber 705. Through this vacuum connector 702, the signal of the cryogenic valve box 100 can be led out to the atmosphere side, and then a connector plug is used for quick insertion for data sampling; an installation cavity is formed inside the transfer vacuum chamber 705, and the transfer cryogenic pipelines 703 (transfer cold shield supply pipe 710, transfer cold shield return pipe 720, transfer 4.5K supply pipe 730, transfer 2K return pipe 740, coupler return pipe 750) in the transfer and transition multi-channel pipeline 700 pass through the installation cavity; a cryogenic connection flange 707 is arranged on the second side of the transfer vacuum chamber 705, and the cryogenic connection flange 707 is used to connect with the cryogenic valve box 100; a corrugated pipe 706 is also arranged at the connection position between the cryogenic connection flange 707 and the cryogenic valve box 100, and the corrugated pipe 706 can be disconnected from the cryogenic connection flange 707 at any time to facilitate the maintenance of internal sensors at any time.

[0101] As Figure 8 shown, the transfer and transition multi-channel pipeline 700 further includes a transfer cold shield 708 arranged on the periphery of the transfer cryogenic pipeline 703. G10 anchor bolts 709 are arranged on the transfer cold shield 708 and are in point contact with the transfer vacuum chamber 705 to reduce conductive heat leakage.

[0102] As Figure 9 shown, Figure 9 is a schematic diagram of the installation of a temperature sensor. Taking the eleventh temperature sensor T11 as an example, a sensor adiabatic cold shield 810 is installed on the transfer cold shield return pipe 720. The eleventh temperature sensor T11 is arranged on the sensor adiabatic cold shield 810 and is fixed by a fastening bolt 802. After being installed according to this method, the temperature sensor can be conveniently disassembled and reused, and effectively isolates the influence of thermal radiation on the high-precision temperature sensor.

[0103] An embodiment of the third aspect of the present invention provides a usage method of a multi-temperature zone heat load and stress test system, and this method includes the following steps: Step S1: Use a cryogenic valve box vacuum acquisition device to evacuate the interlayer of the cryogenic valve box body 110 and the interlayer of the distribution valve box body 240, so that the interlayers of the cryogenic valve box body 110 and the distribution valve box body 240 reach a preset vacuum state.

[0104] Step S2: Open the cryogenic valve of the first pipeline assembly and the cryogenic valve of the distribution and transfer system 200. Open the displacement pump set Pump3 and the normal temperature valve connected to the displacement pump set Pump3 to evacuate the distribution and transfer system 200 and the first pipeline assembly.

[0105] Step S3: Close the displacement pump set Pump3 and the normal temperature valve thereon. Then open the switch valve PV01 on the rewarming gas supply pipeline 222 and the corresponding normal temperature valve, and slowly fill helium gas at 300K into the above pipeline until slightly positive pressure is reached, and then let it stand for a certain period of time to complete one gas replacement process in the pipeline. Step S4: Open the cryogenic valve of the helium cold shield pipeline 121. The refrigeration supply system supplies cryogenic gas to the helium cold shield pipeline 121 through the distribution and transfer system 200 to cool down the cryogenic valve box body 110.

[0106] Step S5: Open the cryogenic valve of the superfluid helium preparation pipeline 122 and the cryogenic valve of the storage tank inlet pipeline 123. The refrigeration supply system supplies cryogenic gas to the superfluid helium preparation pipeline 122 through the distribution and transfer system 200.

[0107] Step S6: When the liquid level measurement value of the liquid level gauge reaches the first threshold, close the cryogenic valve of the superfluid helium preparation pipeline 122 and the cryogenic valve of the storage tank inlet pipeline 123, and obtain multiple first liquid level measurement values measured by the liquid level gauge within the first preset time period.

[0108] Step S7: Obtain the heat leakage of the liquid helium storage tank 130 based on the multiple first liquid level measurement values.

[0109] It can be understood that the heat leakage of the liquid helium storage tank 130 can be obtained through the change of the liquid level of the liquid helium in the liquid helium storage tank 130.

[0110] Step S8: Obtain the measurement data of the strain measurement component on the support component 140, and obtain the mechanical load of the support component 140 based on the measurement data.

[0111] Step S9: Open the superfluid helium acquisition system 500 of the refrigeration supply system. After the liquid helium storage tank 130 acquires 2K superfluid helium, obtain the heat leakage of the liquid helium storage tank 120 based on the liquid level measurement value of the liquid level gauge, obtain the pipeline heat leakage based on the temperature sensor on the pipeline, and obtain the mechanical load of the support component 140 based on the measurement data of the strain measurement component on the support component 140.

[0112] It can be understood that the measurement data of the strain measurement component includes temperature data and stress data. The thermal load of the support component 140 under different rail temperature regions can be obtained through the temperature data, and the stress value of the support component 140 can be obtained through the stress data, and then the fatigue performance of the component material can be evaluated.

[0113] In a specific embodiment of the present invention, the method of use comprises the following steps: Step S1, vacuum the interlayer of the cryogenic valve box body 110 by using a cryogenic valve box vacuum acquisition device, and vacuum the interlayer of the distribution valve box body 240 by using a distribution valve box vacuum acquisition device, so that the cryogenic valve box body 110 and the distribution valve box body 240 reach a preset vacuum state.

[0114] Specifically, all low-temperature valves and normal-temperature valves except the first gate valve BV01 and the second gate valve BV02 are closed, and the low-temperature valve box vacuum acquisition device and the distribution valve box vacuum acquisition device are activated; that is, the mechanical pump in the first vacuum pump group Pump1 and the mechanical pump in the second vacuum pump group Pump2 are activated, and the feedback data of the first vacuum silicon VS01 and the second vacuum silicon VS02 are observed at the same time. When the feedback data of the first vacuum silicon VS01 and the second vacuum silicon VS02 reach about 100Pa, the molecular pump in the mechanical pump of the first vacuum pump group Pump1 and the molecular pump in the second vacuum pump group Pump2 are activated. During the test phase, the mechanical pump and the molecular pump are kept in the normally open state, and the vacuum degree in the vacuum cover 111 of the low-temperature valve box and the vacuum cover 241 of the distribution valve box is maintained at 1×10 -4 Pa level.

[0115] Step S2, maintain the first cryogenic valve CV01 to the fifth cryogenic valve CV05 and the switch valve PV01 in a closed state, open the sixth cryogenic valve CV06 to the fifteenth cryogenic valve CV15, and the third normal temperature valve WV03 to the ninth normal temperature valve WV09, open the replacement pump group Pump3, evacuate the distribution transmission component 210, the normal temperature pipeline 220, the low-pressure branch 230 of the refrigerator system 400, the transfer transition multi-channel pipeline 700, and the pipelines in the cryogenic valve box 100 and the main distribution valve box connected to the above pipelines, monitor the pressure sensors of the first pressure sensor P1 to the fifth pressure sensor P5 and the seventh pressure sensor P7 to the eleventh pressure sensor P11, and wait until the first pressure sensor P1 to the fifth pressure sensor P5 and the seventh pressure sensor P7 to the eleventh pressure sensor P11 are When the maximum value of the value of the pressure sensor P11 is lower than 100Pa, close the replacement pump group Pump3 and the third normal temperature valve WV03 to the seventh normal temperature valve WV07, then open the switch valve PV01, open the first normal temperature valve WV01 and the second normal temperature valve WV02 with a small opening, maintain the pressure of the sixth pressure sensor P6 below 1.5bar, slowly rush 300K helium into the above-mentioned pipeline, pay attention to the maximum value of the values ​​of the first pressure sensor P1 to the fifth pressure sensor P5 and the seventh pressure sensor P7 to the eleventh pressure sensor P11, when it reaches 1.5bar, close the switch valve PV01 and the first normal temperature valve WV01 and the second normal temperature valve WV02, let it stand for about 15 minutes, so that the helium can fully diffuse into each pipeline, and complete a gas replacement process in the pipeline.

[0116] Step S3: Repeat the above step S2 multiple times to ensure the replacement effect.

[0117] 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.

[0118] Step S4, open the seventh cryogenic valve CV07, the ninth cryogenic valve CV09 and the twelfth cryogenic valve CV12, maintain their opening degrees above 90%, open and slowly increase the opening degree of the twelfth cryogenic valve CV12 to cool the cryogenic valve box cold screen 112 and the distribution valve box cold screen 242, monitor the value of the fourth temperature sensor T4, and when it stabilizes to 75K, open and slowly increase the eighth cryogenic valve CV08, and slowly close the ninth cryogenic valve CV09 to improve cold recovery.

[0119] Step S5. After the value of the fourth temperature sensor T4 stabilizes at 75 K, open the first low-temperature valve CV01, which is controlled by the control integration system to maintain the stable operation of the system. Immediately afterwards, open the sixth low-temperature valve CV06 and the tenth low-temperature valve CV10, and maintain their opening degrees above 90%. Adjust the opening degree of the fourteenth low-temperature valve CV14 through the control integration system so that the liquid level in the slightly positive-pressure liquid helium storage tank is 50%. After the value of the 4.5 K liquid helium level gauge LT01 is greater than 40%, the control integration system controls the opening degree of the fifteenth low-temperature valve CV15 so that the liquid level in the slightly positive-pressure liquid helium storage tank is 80%. Further, the minimum opening degrees of the fourteenth low-temperature valve CV14 and the fifteenth low-temperature valve CV15 are set to 10% to prevent overpressure in the 4.5 K gas supply pipeline and the 4.5 K pipeline in the low-temperature valve box 100, resulting in the bursting of the rupture disk and the activation of the safety valve. At the same time, the control integration system controls the output of the fluid-contact DC power heater EH01 so that the value of the 4.5 K 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 transfer 2K return gas pipe 740.

[0120] Further, the control integration system controls the opening degree of the thirteenth low-temperature valve CV13 so that the value of the tenth temperature sensor T10 is about 4.5 K to prevent overheating of this pipeline and transfer heat to the transfer 2K return gas pipe 740 and the transfer 4.5K gas supply pipe 730, resulting in excessive heat load.

[0121] Step S6. After the value of the 4.5 K liquid helium level gauge LT01 (the liquid helium level in the liquid helium storage tank 130) reaches 80%, close the first low-temperature valve CV01, the sixth low-temperature valve CV06, the fourteenth low-temperature valve CV14, and the fifteenth low-temperature valve CV15. Record the value of the 4.5 K liquid helium level gauge LT01 and continue for several hours. The change in the value of the 4.5 K liquid helium level gauge LT01 represents the heat leakage of the slightly positive-pressure liquid helium storage tank.

[0122] Further, the heat leakage of the slightly positive-pressure liquid helium storage tank is calculated by formula (1).

[0123] (1) Where, is the heat leakage of the slightly positive-pressure liquid helium storage tank, with the unit of watt (W); is the density of liquid helium, with the unit of kilogram per cubic meter (kg / m 3 ); is the cross-sectional area of the slightly positive-pressure liquid helium storage tank, with the unit of square meter (m 2 ); Record the time of the numerical change of the 4.5 K liquid helium level gauge after closing the first cryogenic valve, the sixth cryogenic valve, the fourteenth cryogenic valve, and the fifteenth cryogenic valve, with the unit being seconds (s). For the 4.5 K liquid helium level gauge within the attenuation value, with the unit being meters (m). is the latent heat of vaporization of liquid helium, with the unit being joules per kilogram (J / kg).

[0124] Furthermore, the pressure sensor lead-out pipe at the outlet of the liquid helium storage tank 130 has experienced changes from low temperature to 300 K, and its heat leakage can be calculated according to formulas (2) - (3).

[0125] (3) Among them, formula (2) is the thermal conductivity of 316L (austenitic stainless steel) given by the National Institute of Standards and Technology (NIST), with the unit being watts per meter kelvin (W / m·K); formula (3) is the heat leakage calculation formula for the pressure sensor lead-out pipe of the pipeline in different temperature regions. Among them, is the heat leakage of the pressure lead-out pipe in the temperature range from T to 300 K, is the cross-sectional area of the pressure lead-out pipe, with the unit being square meters (m 2 ), is the length of the pressure lead-out pipe, with the unit being meters (m).

[0126] Furthermore, at a certain position of the valve stem sleeve of the cryogenic valve in the cryogenic valve box body, a cold anchor is arranged and connected to the transfer cold shield gas supply pipe to provide 70K thermal shielding protection for the cryogenic valve. The valve stem sleeve of the cryogenic valve is 316L. The heat leakage caused by the cryogenic valve in the cryogenic valve box body is calculated by formula (4), where, is the heat leakage of the cryogenic valve in the temperature range from T to 70K, is the cross-sectional area of the valve stem sleeve of the cryogenic valve, with the unit being square meters (m 2 ), is the length of the valve stem sleeve of the cryogenic valve, with the unit being meters (m).

[0127] (4) Step S7: After completing the above Step S6, execute Step S5 again. When the value of the 4.5 K liquid helium level gauge is greater than 50%, record the values of the temperature sensors, pressure sensors, and flow meters on each cryogenic pipeline of the transfer and transition multi-channel pipeline and on each cryogenic pipeline inside the cryogenic valve box. According to the values of the pressure sensors and temperature sensors, the enthalpy value (h) of helium can be queried in the HEPAKE software, and the heat leakage of each cryogenic pipeline can be calculated according to formula (5).

[0128] (5) where is the heat leakage of the cryogenic pipeline at a temperature of in the 4.5 K temperature range, is the flow rate through the cryogenic pipeline at a temperature of in the 4.5 K temperature range, is the enthalpy difference between the two temperature measurement points at both ends of the cryogenic pipeline at a temperature of in the 4.5 K temperature range.

[0129] Step S8: The strain measurement component on the support assembly includes multiple temperature sensors. In the above Step S7, record the signals of the temperature sensors on the support assembly, and the heat load of the support assembly in the 4.5 K temperature range can be obtained from formula (6).

[0130] (6) where is the heat load of the support assembly in the 4.5 K temperature range, with the unit of watt (W); is the average thermal conductivity of the material between the temperature sensors calculated from formula (2), is the serial number of the temperature sensor on the support assembly, and the subscript represents the physical quantity in the characteristic temperature range is the distance between two adjacent temperature sensors on the support assembly.

[0131] Step S9: 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 270 K.

[0132] It can be understood that by opening the 2K gas heater 510 of the superfluid helium acquisition system 500, controlling the integrated system to control the temperature of the helium gas entering the superfluid helium decompression and cooling pump group 520 to be 270 - 300 K, and preheating the 2K gas heater for 10 minutes to fully heat the 2K gas heater 510.

[0133] Step S10: Turn on the superfluid helium decompression and cooling pump set 520, close the tenth cryogenic valve CV10, and slowly open the eleventh cryogenic valve CV11. Further, the initial opening of the eleventh cryogenic valve CV11 is 2%. Monitor that the helium temperature entering the superfluid helium decompression and cooling pump set 520 is not lower than 260K, and gradually increase the opening of the eleventh cryogenic valve CV11.

[0134] Step S11: When the value of the 2K superfluid helium level gauge tends to be stable, record the values of the temperature sensors, pressure sensors, and flow meters on each cryogenic pipeline of the transfer and transition multi-channel pipeline 700 and on each cryogenic pipeline in the cryogenic valve box body 110. According to the values of the pressure sensors and temperature sensors, the enthalpy value (h) of helium can be queried in the HEPAKE software, and the heat leakage of each cryogenic pipeline can be calculated according to formula (7).

[0135] (7) where, is the heat leakage of the cryogenic pipeline at a temperature of in the 2K temperature range, is the flow rate through the cryogenic pipeline at a temperature of in the 2K temperature range, is the enthalpy difference between the two ends of the temperature measurement points of the cryogenic pipeline at a temperature of in the 2K temperature range.

[0136] Step S12: In the above step S11, record the signals of the temperature sensors on the support assembly, and the heat load of the support at 2K can be obtained from formula (8).

[0137] (8) where, is the heat load of the support system at 2K, with the unit of watt (W); is the average thermal conductivity of the material between the temperature sensors calculated from formula (2), is the serial number of the temperature sensor on the support assembly, and the subscript represents the physical quantity in the characteristic temperature range

[0138] is the distance between two adjacent temperature sensors on the support assembly.

[0138] Step S13: The strain measurement assembly on the support assembly 140 further includes a plurality of strain gauges. The number of strain gauges is equal to the number of temperature sensors on the support assembly 140, and their positions correspond one by one. Temperature sensors are arranged around the strain gauges. Taking one strain gauge and one temperature sensor as a strain measurement unit 141, the strain measurement assembly includes a plurality of strain measurement units 141, where the temperature sensors are high-precision temperature sensors.

[0139] When the cooling of the low-temperature valve box 100 starts, record the data of the strain gauge and the temperature sensor in a strain measurement unit 141 simultaneously, and the dynamic response curve of strain-temperature can be obtained; the strain gauge is a resistive strain gauge. When strain occurs, the resistance value of the strain gauge changes. The resistance is obtained through a quarter-bridge. According to formula (9), the strain value can be calculated, and according to formula (10), the stress value can be obtained. Based on the experimental values, the fatigue performance of the material of the support assembly 140 can be evaluated.

[0140] (9) (10) Among them, is the resistance difference, is the initial resistance, 1 is the sensitivity, is the strain value, is the elastic modulus, is the stress value, and the subscript represents the physical quantity in the characteristic temperature range under, is the strain gauge serial number, and j is the measured value of the strain gauge at different positions.

[0141] It should be noted that when the above step S4 starts to execute, connect the strain gauge to the collector, and set the zero point to zero to clear the initial error.

[0142] Step S14: After completing the above tests, open the tenth cryogenic valve CV10, close the eleventh cryogenic valve CV11, close the superfluid helium acquisition system 500, gradually close the first cryogenic valve CV01, gradually close the second cryogenic valve CV02, and stop inputting cold energy to the main distribution valve box and the low-temperature valve box 100.

[0143] Step S15: Open the fluid-contact DC power heater EH01, set it to about 80% of the full power, and wait until the value of the 4.5 K liquid helium level gauge LT01 is 0, then close the fluid-contact DC power heater EH01.

[0144] Step S16: When the minimum value of the first temperature sensor T1 to the fifteenth temperature sensor T15 reaches 70 K, open the switching valve PV01, the first normal-temperature valve WV01, and the second normal-temperature valve WV02, and input 300 K normal temperature to the distribution valve box body 240 and the low-temperature valve box body 110 to accelerate the rewarming speed.

[0145] Step S17: When the temperature sensors in the distribution valve box body 240 and the low-temperature valve box body 110 approach normal temperature, turn off the first vacuum pump group Pump1 connected to the distribution valve box body 240 and the second vacuum pump group Pump2 connected to the low-temperature valve box body 110.

[0146] 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 foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A cryogenic valve box for a superfluid helium cryogenic system, characterized in that: include: A low-temperature valve box body, wherein one side of the low-temperature valve box body has a convex portion convex outward, and the low-temperature valve box body has a low-temperature valve box cold shield; A support assembly is located in the cryogenic valve box body and is disposed on the convex portion; a first pipeline assembly, comprising a helium cold shield pipeline and a superfluid helium preparation pipeline, both ends of the helium cold shield pipeline and both ends of the superfluid helium preparation pipeline are installed on the support assembly, and the helium cold shield pipeline is connected to the low-temperature valve box cold shield, and both the helium cold shield pipeline and the superfluid helium preparation pipeline are provided with a low-temperature valve, a pressure sensor and a temperature sensor; A liquid helium storage tank, wherein the inlet end of the liquid helium storage tank is connected to the superfluid helium preparation pipeline through a storage tank inlet pipeline, the storage tank inlet pipeline is provided with a cryogenic valve, the outlet end of the liquid helium storage tank is connected to a storage tank return pipeline, the storage tank return pipeline is provided with a pressure sensor, the storage tank return pipeline is installed on the support assembly, and the liquid helium storage tank is provided with a liquid level meter; A cryogenic valve box vacuum acquisition device connected to the cryogenic valve box body; The strain measurement component is arranged on the support component, and the strain measurement component is used to measure the mechanical load of the support component.

2. The cryogenic valve box for a superfluid helium cryogenic system according to claim 1, characterized in that: The superfluid helium preparation pipeline is provided with a flow meter; The input end of the storage tank inlet pipeline is located at the outlet side of the flow meter. The storage tank inlet pipeline has two output branches, and each output branch is provided with the low-temperature valve and the temperature sensor.

3. The cryogenic valve box for a superfluid helium cryogenic system according to claim 1, characterized in that: The liquid helium storage tank is provided with a temperature sensor and / or a heater.

4. The cryogenic valve box for a superfluid helium cryogenic system according to any one of claims 1 to 3, characterized in that: The helium cooling shield pipeline and the superfluid helium preparation pipeline are both connected to a safety relief device, which includes a connecting pipeline and a safety valve and a bursting disc arranged on the connecting pipeline. The connecting pipeline is connected to a recovery and purification system, and the connecting pipeline is connected to a replacement pump group through a normal temperature valve.

5. The cryogenic valve box for a superfluid helium cryogenic system according to any one of claims 1 to 3, characterized in that: The tank return air pipeline is connected to a negative pressure protection and safety discharge integrated device, which includes a negative pressure protection shell, a primary safety valve, a secondary safety valve and a bursting disc; The negative pressure protection shell is used to be connected with 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 return air pipeline of the storage tank, the secondary safety valve and the bursting disc are connected with the negative pressure protection shell in sequence, and the secondary safety valve and the bursting disc are connected with the atmosphere.

6. A low temperature valve box multi-temperature zone heat load and stress testing system, characterized in that: It comprises a refrigeration supply system, a distribution and transmission system, and a cryogenic valve box for a superfluid helium cryogenic system according to any one of claims 1 to 5; the refrigeration supply system is connected to a support assembly through the distribution and transmission system, and the refrigeration supply system, the distribution and transmission system and the first pipeline assembly are connected to form a closed loop.

7. The cryogenic valve box multi-temperature zone heat load and stress testing system according to claim 6, characterized in that: Also included is a transfer transition multi-channel pipeline, the transfer transition multi-channel pipeline comprising: A switching cold shield air supply pipe, wherein the input end of the switching cold shield air supply pipe is connected to the distribution and transmission system, and the output end of the switching cold shield air supply pipe is connected to the input end of the helium cold shield pipeline; A transfer cold screen return pipe, wherein the input end of the transfer cold screen return pipe is connected to the output end of the helium cold screen pipeline, and the output end of the transfer cold screen return pipe is connected to the distribution and transmission system; A 4.5K gas supply pipe is connected, wherein the input end of the 4.5K gas supply pipe is connected to the distribution and transmission system, and the output end of the 4.5K gas supply pipe is connected to the input end of the superfluid helium preparation pipeline; A 2K air return pipe is connected, wherein the input end of the 2K air return pipe is connected to the output end of the tank air return pipeline, and the output end of the 2K air return pipe is connected to the distribution and transmission system; A coupler gas return pipe, wherein the input end of the coupler gas return pipe is connected to the output end of the superfluid helium preparation pipeline, and the output end of the coupler gas return pipe is connected to the switching 2K gas return pipe; The switching cold screen air supply pipe, the switching cold screen air return pipe, the switching 4.5K air supply pipe, the switching 2K air return pipe, and the coupler air return pipe are all provided with temperature sensors.

8. The cryogenic valve box multi-temperature zone heat load and stress testing system according to claim 7, characterized in that: The switching cold screen return air pipe and / or the switching 2K return air pipe are provided with a flow meter.

9. The cryogenic valve box multi-temperature zone heat load and stress testing system according to claim 7, characterized in that: The distribution transmission system comprises: A distribution and transmission assembly, including a cold screen air supply line, a cold screen air return line, a 4.5K air intake line, a 2K air return line, and a cooling air return line connected to the refrigeration supply system; The main distribution valve box includes a distribution valve box body, a distribution valve box vacuum acquisition device and a second pipeline assembly arranged in the distribution valve box body, wherein the second pipeline assembly includes a cold screen air intake pipeline, a cold screen air return pipeline, a helium air intake pipeline and a helium air return pipeline, and the cold screen air intake pipeline, the cold screen air return pipeline, the helium air intake pipeline and the helium air return pipeline are all provided with a cryogenic valve, a pressure sensor and a temperature sensor; the cold screen air supply line is connected to the switching cold screen air supply pipe through the cold screen air intake pipeline; the 4.5K air intake line is connected to the switching through the helium air intake pipeline 4.5K air supply pipe; the input end of the cold screen return air pipeline is connected to the switching cold screen return air pipe, and the cold screen return air pipeline has two output branches, one of which is connected to the cold screen return air line through a low-temperature valve, and the other is connected to the cooling return air line through a low-temperature valve; the input end of the helium return air pipeline is connected to the switching 2K return air pipe, and the helium return air pipeline has two output branches, one of which is connected to the 2K return air line through a low-temperature valve, and the other is connected to the cooling return air line through a low-temperature valve.

10. A method for using a low temperature valve box multi-temperature zone heat load and stress testing system, characterized in that: include: Step S1, vacuuming the interlayer of the cryogenic valve box body and the interlayer of the distribution valve box body by using a cryogenic valve box vacuum acquisition device, so that the interlayer of the cryogenic valve box body and the interlayer of the distribution valve box body reach a preset vacuum state; Step S2, opening the cryogenic valve of the first pipeline assembly and the cryogenic valve of the distribution and transmission system, opening the replacement pump group and the normal temperature valve connected to the replacement pump group, and evacuating the distribution and transmission system and the first pipeline assembly; Step S3, close the replacement pump group, open the switch valve on the rewarming gas supply pipeline of the distribution transmission system, flush 300K helium into the pipeline to a slight positive pressure, and then let it stand for a certain period of time to complete a gas replacement process in the pipeline; Step S4, opening the cryogenic valve of the helium cold shield pipeline, and the refrigeration supply system supplies cryogenic gas to the helium cold shield pipeline through the distribution transmission system to cool down the cryogenic valve box body; Step S5, opening the cryogenic valve of the superfluid helium preparation pipeline and the cryogenic valve of the storage tank inlet pipeline, and the refrigeration supply system supplies cryogenic gas to the superfluid helium preparation pipeline through the distribution transmission system; Step S6: when the liquid level measurement value of the liquid level meter reaches a first threshold, close the cryogenic valve of the superfluid helium preparation pipeline and the cryogenic valve of the storage tank inlet pipeline, and obtain a plurality of first liquid level measurement values ​​measured by the liquid level meter within a first preset time period; Step S7, obtaining the heat leakage of the liquid helium storage tank based on the multiple first liquid level measurement values; Step S8, obtaining measurement data of the strain measurement component on the support component, and obtaining the mechanical load of the support component based on the measurement data; Step S9, turn on the superfluid helium acquisition system of the refrigeration supply system. After the liquid helium storage tank acquires 2K superfluid helium, obtain the heat leakage of the liquid helium storage tank based on the liquid level measurement value of the liquid level meter, obtain the heat leakage of the pipeline based on the temperature sensor on the pipeline, and obtain the mechanical load of the support assembly based on the measurement data of the strain measurement assembly on the support assembly.

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