Pressure sensor helium protection structure applied to superfluid helium negative pressure pipeline

Abstract

The utility model relates to the technical field of low-temperature engineering, in particular to a pressure sensor helium protection structure applied to a superfluid helium negative pressure pipeline, which comprises a sealed container, and a pressure sensor on the superfluid helium negative pressure pipeline is positioned in the sealed container. A superfluid helium negative pressure pipeline connected with the pressure sensor enters the sealed container and is in sealed connection with the sealed container, the sealed container is provided with a gas inlet pipeline, and the helium source provides micro-positive pressure helium for the sealed container through the gas inlet pipeline; the pressure sensor on the superflow helium negative pressure pipeline is arranged in the sealed container, and the container is filled with micro-positive pressure helium, so that the structure can ensure that external air cannot be leaked into a negative pressure pipeline system through the pressure sensor under any condition, and the safety of the system is ensured. Therefore, external air is prevented from entering the superflow helium negative pressure pipeline when the system is shut down or micro leakage occurs at the interface of the pressure sensor, so that the pollution of the whole system is prevented.

Description

Technical Field

[0001] The utility model relates to the technical field of cryogenic engineering, and particularly relates to a helium protection structure for a pressure sensor applied to a superfluid helium negative pressure pipeline. Background Art

[0002] With the rapid development of modern science and technology, large-scale scientific projects such as particle accelerators and controlled nuclear fusion devices are advancing at an unprecedented speed. These cutting-edge scientific and technological devices not only require superconducting magnets and superconducting accelerating cavities to achieve stronger magnetic field intensities and higher acceleration gradients, but also pose more stringent requirements on the helium cryogenic system that provides cooling for them. Traditionally, the helium cryogenic system mainly operates in the liquid helium temperature range of 4.2K. However, in order to further explore the properties of substances at lower temperatures, especially to reach the superfluid helium temperature range of 2K, a negative pressure environment must be introduced into the pipeline system to maintain this extremely low temperature state.

[0003] At present, the existing ultra-low temperature cold boxes mainly reach the liquid helium temperature range of 4.2K. The connection structures between the pressure sensors arranged on their pipelines and the pipelines are mainly threaded and metal-sealed ferrule joints. The sealing effects of these two connection structures are not good and there is a possibility of leakage. However, in the pipelines in this temperature range, it is a positive pressure environment. When the internal pressure of the system is greater than the external pressure, it is not easy for external air to enter the internal system. However, in a negative pressure pipeline, when the system stops or there is a micro-leakage at the temperature sensor interface, external air is likely to enter the cryogenic system, causing pollution to the entire system. Content of the Utility Model

[0004] Aiming at the deficiencies of the prior art, the utility model provides a helium protection structure for a pressure sensor applied to a superfluid helium negative pressure pipeline, aiming to solve the problem that when the system stops or there is a micro-leakage at the temperature sensor interface in a negative pressure pipeline, external air is likely to enter the cryogenic system, causing pollution to the entire system.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions: it includes a sealed container. The pressure sensor on the superfluid helium negative pressure pipeline is located inside the sealed container. The superfluid helium negative pressure pipeline connected to the pressure sensor enters the sealed container and is hermetically connected to the sealed container. The sealed container has an air inlet pipeline, and a helium gas source provides slightly positive pressure helium gas to the sealed container through the air inlet pipeline.

[0006] Furthermore, it also includes a pressure control valve arranged on the air inlet pipeline. The pressure control valve can control the pressure of the helium gas provided by the helium gas source and control the pressure of the helium gas entering the sealed container to be slightly positive pressure.

[0007] Further, it also includes a pressure gauge arranged on the intake pipeline, and the pressure gauge is arranged between the pressure control valve and the sealed container for measuring and displaying the pressure value of the slightly positive-pressure helium gas introduced into the sealed container.

[0008] Further, it also includes an intake valve arranged on the intake pipeline. The helium gas source is connected to the intake valve through a pipeline, and the helium gas source transports helium gas to the intake pipeline through the intake valve.

[0009] Further, the sealed container also includes an exhaust pipeline, and a safety valve is arranged on the exhaust pipeline to discharge helium gas in time when the pressure in the container exceeds the limit.

[0010] Further, the sealed container includes a container body and a first flange. One end of the container body is integrally formed with a second flange that is hermetically connected to the first flange. A sealing member is arranged between the first flange and the second flange, and the sealing member is hermetically connected to the first flange and the second flange. The superfluid helium negative-pressure pipeline sequentially passes through the first flange and the sealing member and enters the sealed container, and the sealing member is in sealing contact with the superfluid helium negative-pressure pipeline.

[0011] Further, the sealing member is a transition sealing disk arranged between the first flange and the second flange.

[0012] Further, O-ring seals are arranged between the transition sealing disk and both the first flange and the second flange.

[0013] Further, the sealed container also includes an end cover that is detachably arranged on the container body and is hermetically connected to the container body.

[0014] Further, an aviation plug is arranged on the sealed container, and the pressure sensor in the sealed container is electrically connected to an external controller through the aviation plug.

[0015] A pressure sensor helium protection structure and its control method applied to a superfluid helium negative-pressure pipeline described in the present utility model have the beneficial effects that by placing the pressure sensor on the superfluid helium negative-pressure pipeline in a sealed container and filling the inside of the container with slightly positive-pressure helium gas, this structure can ensure that under any circumstances, external air cannot leak into the negative-pressure pipeline system through the pressure sensor, which avoids external air entering the superfluid helium negative-pressure pipeline when the system is shut down or there is a slight leak at the pressure sensor interface, thereby preventing the pollution of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a three-dimensional view of an embodiment of the pressure sensor helium protection structure of the present utility model;

[0017] Figure 2 is a plan view of an embodiment of the pressure sensor helium protection structure of the present utility model.

[0018] Explanation of the reference numerals: 1. Container body; 11. Air inlet pipeline; 111. Air inlet valve; 112. Pressure control valve; 113. Pressure gauge; 12. Exhaust pipeline; 121. Safety valve; 13. First flange; 14. Second flange; 15. Transition sealing disk; 16. End cover; 17. Aviation plug; 2. Pressure sensor; 3. Superfluid helium negative pressure pipeline. DETAILED DESCRIPTION

[0019] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions and illustrations therein are essentially for illustrative purposes rather than for limiting the present invention.

[0020] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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 present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0021] In order to further illustrate the principle and structure of the present utility model, the preferred embodiments of the present utility model are now described in detail with reference to the accompanying drawings.

[0022] like Figure 1 As shown, an embodiment of the utility model provides a helium protection structure for a pressure sensor 2 applied to a superfluid helium negative pressure pipeline 3, comprising: a sealed container, the pressure sensor 2 on the superfluid helium negative pressure pipeline 3 is located in the sealed container, the superfluid helium negative pressure pipeline 3 connected to the pressure sensor 2 enters the sealed container and is sealedly connected to the sealed container; the sealed container has an air inlet pipeline 11, an external helium source is connected to the air inlet pipeline 11, and slightly positive pressure helium is provided to the sealed container through the air inlet pipeline 11.

[0023] The sealed container provides a fully enclosed environment, completely isolating the pressure sensor 2 from the external environment. An external helium gas source supplies slightly positive-pressure helium gas into the sealed container, filling the sealed chamber with helium gas. The slightly positive-pressure helium gas can increase the internal pressure of the container, making it slightly higher than the external environment, effectively preventing the entry of external air and improving the sealing effect of the sealed container. Moreover, helium gas can form a protective layer around the pressure sensor 2. When there is a slight leak at the temperature sensor interface, it can ensure that the air entering the superfluid helium negative-pressure pipeline 3 is helium gas, avoiding the entry of external air into the system.

[0024] By placing the pressure sensor 2 on the superfluid helium negative-pressure pipeline 3 inside the sealed container and filling the inside of the container with slightly positive-pressure helium gas, this structure can ensure that under any circumstances, external air cannot leak into the negative-pressure pipeline system through the pressure sensor 2. This avoids the entry of external air into the superfluid helium negative-pressure pipeline 3 when the system is shut down or there is a slight leak at the pressure sensor 2 interface, thus preventing the contamination of the entire system.

[0025] Furthermore, the above-mentioned sealed container includes a container body 1 and a first flange 13. The container body 1 is a hollow columnar structure. The first flange 13 is hermetically connected to the lower end of the container body 1. The lower end of the container body 1 is integrally formed with a second flange 14 adapted to the first flange 13. The first flange 13 and the second flange 14 are hermetically connected and fixed by bolts.

[0026] The above-mentioned first flange 13 is provided with through holes corresponding to the pipeline (superfluid helium negative-pressure pipeline 3) connected to the pressure sensor 2. The pipeline connected to the pressure sensor 2 can pass through the through holes upward from the bottom of the sealed container and enter the sealed container.

[0027] Furthermore, in order to enhance the sealing between the sealed container and the pipeline and prevent the helium gas in the sealed container from leaking outwards, a sealing member is also provided. The sealing member is arranged between the first flange 13 and the second flange 14 and is hermetically connected to the first flange 13 and the second flange 14. The pipeline needs to pass through the first flange 13 and the sealing member in sequence when entering the sealed container. The sealing member is in sealing contact with the pipeline to improve the sealing performance of the sealed container.

[0028] Specifically, the sealing member is a transition sealing disk 15 arranged between the first flange 13 and the second flange 14. The transition sealing disk 15 is made of rubber or silica gel material. The transition sealing disk 15 is provided with through holes that can closely fit the pipeline. After the pipeline passes through the transition sealing disk 15, the inner wall of the through hole of the transition sealing disk 15 closely fits the pipeline, thereby enhancing the sealing performance of the sealed container.

[0029] Furthermore, O-ring seals are provided between the transition sealing disk 15 and the first flange 13 and the second flange 14 respectively, so as to realize the sealed connection between the transition sealing disk 15 and the first flange 13 and the second flange 14.

[0030] Furthermore, the sealed container further includes a flange-equipped end cover 16 detachably arranged at the upper end of the container body 1. The end cover 16 is hermetically connected to the container body 1. The detachable end cover 16 facilitates the installation or removal of the pressure sensor 2 and also facilitates the internal wiring of the sealed container.

[0031] Furthermore, an aviation plug 17 is provided on the sealed container. The pressure sensor 2 inside the sealed container is electrically connected to the aviation plug 17. The aviation plug 17 facilitates leading out the control wire of the pressure sensor 2 to the outside and facilitates the electrical connection between the pressure sensor 2 and an external controller.

[0032] Furthermore, in order to control the helium pressure provided by the helium source and maintain the safety of the system, a pressure control valve 112 is further provided on the intake pipeline 11. The pressure control valve 112 can accurately regulate the flow rate and pressure of the slightly positive-pressure helium gas entering the sealed container, ensuring that the helium gas inside the container remains in a suitable slightly positive-pressure state. This is to protect the superfluid helium negative-pressure pipeline 3 and prevent external air from entering the sealed chamber through possible leakage points, avoiding the superfluid helium negative-pressure pipeline 3 from sucking in external air.

[0033] Furthermore, a pressure gauge 113 is further provided on the intake pipeline 11. The pressure gauge 113 is arranged between the pressure control valve 112 and the sealed container. The pressure gauge 113 measures and displays the pressure value of the slightly positive-pressure helium gas accessing the sealed container. Operators can intuitively understand the pressure situation inside the helium protection container through the pressure gauge 113, ensuring that the helium gas remains in a suitable slightly positive-pressure state to effectively isolate external air.

[0034] Furthermore, an intake valve 111 is further provided on the intake pipeline 11. The helium source is connected to the intake valve 111 through a pipeline. The helium source transports helium gas to the intake pipeline 11 through the intake valve 111. Operators can quickly adjust and maintain the pressure environment inside the sealed container by opening or closing the intake valve 111.

[0035] Furthermore, in addition to the intake pipeline 11, the sealed container further includes an exhaust pipeline 12. The exhaust pipeline 12 is mainly used to discharge excess helium gas when the internal pressure of the sealed container exceeds the set safety value. By timely discharging the overpressure gas, the exhaust pipeline 12 helps to maintain the stability of the internal pressure of the system and ensure the safe operation of the equipment within the specified pressure range.

[0036] In order to achieve the purpose that when the internal pressure of the exhaust pipe 12 in the sealed container exceeds the set safety value, the redundant helium gas is discharged, a safety valve 121 is provided on the exhaust pipe 12. When the pressure in the sealed container exceeds the set safety threshold, the safety valve 121 will automatically open to release part of the helium gas to reduce the pressure. The safety valve 121 can respond quickly without manual intervention, effectively prevent the occurrence of overpressure accidents, and ensure the stable operation and safety of the system.

[0037] The above is only a preferred embodiment of the present invention, and does not impose any limitation on the technical scope of the present invention. Therefore, any minor modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A helium protection structure for a pressure sensor applied to a superfluid helium negative pressure pipeline, characterized in that, Comprising: A sealed container, a pressure sensor on the superfluid helium negative pressure pipeline is located inside the sealed container, and the superfluid helium negative pressure pipeline connected to the pressure sensor enters the sealed container and is sealedly connected to the sealed container; the sealed container has an air inlet pipeline, and a helium gas source provides helium gas with a slightly positive pressure to the sealed container through the air inlet pipeline.

2. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline according to claim 1, wherein, It further comprises a pressure control valve arranged on the air inlet pipeline, and the pressure control valve can control the pressure of the helium gas provided by the helium gas source to control the pressure of the helium gas entering the sealed container to be slightly positive pressure.

3. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline according to claim 2, characterized in that It further comprises a pressure gauge arranged on the air inlet pipeline, and the pressure gauge is arranged between the pressure control valve and the sealed container for measuring and displaying the pressure value of the slightly positive pressure helium gas accessing the sealed container.

4. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline as described in claim 3, wherein, It further comprises an air inlet valve arranged on the air inlet pipeline, the helium gas source is pipeline-connected to the air inlet valve, and the helium gas source transports helium gas to the air inlet pipeline through the air inlet valve.

5. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline as described in claim 1, wherein The sealed container further comprises an exhaust pipeline, and a safety valve is arranged on the exhaust pipeline to timely discharge helium gas when the container is overpressured.

6. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline as described in claim 1, characterized in that, The sealed container comprises a container body and a first flange, a second flange hermetically connected to the first flange is integrally formed at one end of the container body, a sealing member is arranged between the first flange and the second flange, the sealing member is hermetically connected to the first flange and the second flange, the superfluid helium negative pressure pipeline sequentially passes through the first flange and the sealing member and enters the sealed container, and the sealing member is in sealed contact with the superfluid helium negative pressure pipeline.

7. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline according to claim 6, characterized in that, The sealing member is a transition sealing disc arranged between the first flange and the second flange.

8. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline as described in claim 7, characterized in that, O-ring seals are arranged between the transition sealing disc and both the first flange and the second flange.

9. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline according to claim 6, wherein The sealed container further comprises an end cover detachably arranged on the container body and hermetically connected to the container body.

10. The helium protection structure of the pressure sensor applied to the superfluid helium negative pressure pipeline according to claim 1, characterized in that, An aviation plug is arranged on the sealed container, and the pressure sensor inside the sealed container is electrically connected to an external controller through the aviation plug.

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