Absolute pressure valve and superconducting magnet system

Abstract

The utility model discloses an absolute pressure valve and a superconducting magnet system, the absolute pressure valve comprises a shell and a piston, the shell is internally provided with a first chamber and a second chamber, and the shell is provided with an air inlet hole and an air outlet hole which are communicated with the second chamber; the piston is movably arranged in the shell, and at least part of the piston can extend into the second cavity to close or open the air inlet hole; wherein the first cavity is provided with a pressure substance for providing pressure for the piston so as to drive the piston to close the air inlet hole, and the shell is provided with a vent hole which is communicated with the first cavity and used for exhausting or inflating the first cavity. According to the absolute pressure valve disclosed by the utility model, the pressure substance is arranged in the first cavity isolated from the external environment, so that the pressure applied to the piston by the pressure substance cannot be influenced even if the external pressure is changed, and the absolute pressure valve can ensure that the emission of helium in the superconducting magnet is not influenced by the change of the environmental pressure; and a constant-pressure exhaust function is realized.

Description

Technical Field

[0001] The utility model relates to the field of pressure relief devices, and more particularly to an absolute pressure valve and a superconducting magnet system. Background Art

[0002] The pressure relief device is an important component necessary for superconducting magnets. A superconducting magnet is a device that uses liquid helium as a refrigerant to achieve superconducting operation at low temperatures. Therefore, a large amount of liquid helium gas is used during operation. Once a problem, emergency, or special operating condition occurs, the pressure of the magnet will increase. When the pressure changes, we need a pressure relief device to release the unnecessary pressure to ensure safety.

[0003] During the transportation of superconducting magnets, the refrigerators are usually in a shutdown state. The heat leakage into the magnet cannot be taken away by the refrigerator. This heat leakage will inevitably cause the evaporation of the stored liquid helium in the liquid helium cavity inside the superconducting magnet, resulting in an increase in the pressure inside the superconducting magnet. Therefore, there will be helium gas leakage during transportation.

[0004] In related technologies, the pressure relief device uses a one-way valve, and the one-way valve discharges gas through the pressure difference between the inside of the superconducting magnet and the external environment. During land transportation, if passing through high-altitude areas, due to the change in air pressure, a large amount of abnormal exhaust will occur inside the superconducting magnet, resulting in over-relief. During air transportation, due to the pressure change or sudden loss of pressure in the cargo aircraft cabin, the helium gas discharge inside the superconducting magnet will also increase.

[0005] In summary, an absolute pressure valve device is needed to ensure that the helium gas discharge inside the superconducting magnet is not affected by changes in environmental pressure, such as high altitude and air transportation, and to achieve the function of constant pressure exhaust. Summary of the Utility Model

[0006] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides an absolute pressure valve, which can ensure that the helium gas discharge inside the superconducting magnet is not affected by changes in environmental pressure and achieve the function of constant pressure exhaust.

[0007] The utility model also provides a superconducting magnet system having the above absolute pressure valve.

[0008] The absolute pressure valve according to the first aspect of the present utility model includes: a housing having a first chamber and a second chamber therein, and an air inlet hole and an air vent hole communicating with the second chamber are provided on the housing; a piston movably disposed in the housing and at least partially extendable into the second chamber to close or open the air inlet hole; wherein, a pressure substance for providing pressure to the piston is disposed in the first chamber to drive the piston to close the air inlet hole, and a vent hole communicating with the first chamber and used for evacuating or inflating the first chamber is provided on the housing.

[0009] According to the absolute pressure valve of the present utility model, since the pressure substance is disposed in the first chamber isolated from the external environment, even if the external pressure changes, it will not affect the pressure exerted by the pressure substance on the piston, enabling the absolute pressure valve to ensure that the helium gas discharge inside the superconducting magnet is not affected by the change of the environmental pressure and realizing the function of constant pressure exhaust. After the pressure inside the superconducting magnet system reaches a certain value, the absolute pressure valve automatically opens to release the pressure to protect the safety of the superconducting magnet system; when the pressure drops to the specified pressure, the absolute pressure valve can automatically close again to reduce the loss of helium gas in the superconducting magnet system. It can achieve both safety and unattended automatic control, effectively realizing the stability, high efficiency and safety of the release and closing functions.

[0010] In some embodiments, the pressure substance is an elastic member and is supported between the housing and the piston; the first chamber is configured as a vacuum chamber through the vent hole.

[0011] In some embodiments, the elastic member is a spring, and the spring can be any one of a compression spring, a torsion spring, a coil spring, a gas spring, a torsion spring, a wave spring, a butterfly spring or an elastic bellows.

[0012] In some embodiments, the pressure substance is a pressure gas, and the pressure gas is injected into the first chamber through the vent hole.

[0013] In some embodiments, the absolute pressure valve further includes: a sealing plug disposed in the housing, the first chamber and the second chamber are separated on both sides of the sealing plug, and the piston penetrates through the sealing plug along the arrangement direction of the first chamber and the second chamber and is movable relative to the sealing plug along the penetration direction.

[0014] In some embodiments, one end of the piston away from the second chamber has a mounting table protruding towards the first chamber, and the pressure substance is a spring and is sleeved on the mounting table.

[0015] In some embodiments, the pressure substance is a pressure gas, and the pressure gas is injected into the first chamber through the ventilation hole. One end of the piston away from the second chamber has a receiving groove recessed in the direction of the second chamber, and the receiving groove communicates with the first chamber.

[0016] In some embodiments, the piston includes a piston shaft and a sealing boss. The piston shaft passes through the sealing plug, and the first end of the piston shaft extends into the second chamber. The sealing boss is disposed around the first end and is blocked in the second chamber by the sealing plug. The air inlet hole is disposed opposite to the first end, and a first sealing ring is disposed on the housing around the air inlet hole. When the first end closes the air inlet hole, the sealing boss is in sealing cooperation with the first sealing ring.

[0017] In some embodiments, a second sealing ring is disposed at a position of the sealing plug around the piston shaft. The second sealing ring is in sealing cooperation with the outer peripheral surface of the piston shaft. In the axial direction, the acting force of the second sealing ring on the piston shaft is the same as the acting force of the first sealing ring on the piston shaft.

[0018] The superconducting magnet system according to the second aspect of the present invention includes an absolute pressure valve according to the first aspect of the present invention.

[0019] According to the superconducting magnet system of the embodiment of the present invention, by providing the absolute pressure valve of the first aspect, the helium gas discharge inside the superconducting magnet is not affected by the change of the ambient pressure, and the function of constant pressure exhaust is realized.

[0020] The additional aspects and advantages of the present invention will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of the present invention. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of an absolute pressure valve according to an embodiment of the present invention;

[0022] Figure 2 is a schematic structural diagram of an absolute pressure valve according to another embodiment of the present invention.

[0023] Reference Signs:

[0024] Absolute pressure valve 100;

[0025] Housing 1; First chamber 11; Second chamber 12; Air inlet hole 13; Air discharge hole 14; Ventilation hole 15; Housing body 1a; Sealing flange 1b;

[0026] Piston 2; Piston shaft 2a; Mounting table 21; Receiving groove 22; Sealing boss 2b;

[0027] Pressure substance 3; elastic member 3a;

[0028] Sealing plug 4;

[0029] First sealing ring 5;

[0030] Second sealing ring 6. Specific implementation manner

[0031] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are intended to explain the present utility model, and should not be construed as limiting the present utility model.

[0032] The following disclosure provides many different embodiments or examples for implementing different structures of the present utility model. To simplify the disclosure of the present utility model, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present utility model. In addition, the present utility model may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed. In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the applicability of other processes and / or the use of other materials.

[0033] The absolute pressure valve 100 according to the embodiment of the present utility model will be described below with reference to the drawings.

[0034] The absolute pressure valve 100 according to the embodiment of the present utility model is used for a superconducting magnet system. The superconducting magnet system is a device that uses liquid helium as a refrigerant to achieve superconducting operation at low temperatures. When problems, emergencies, or special operating conditions occur, the liquid helium inside the superconducting magnet system vaporizes, causing the pressure inside the superconducting magnet system to rise. The absolute pressure valve 100 can release the pressure in a timely manner to ensure safety.

[0035] According to the absolute pressure valve 100 of the embodiment of the present utility model, as Figure 1 shown, the absolute pressure valve 100 includes: a housing 1 and a piston 2. The housing 1 has a first chamber 11 and a second chamber 12. An air inlet hole 13 and an air release hole 14 communicating with the second chamber 12 are provided on the housing 1. The piston 2 is movably arranged in the housing 1 and at least partially extends into the second chamber 12 to close or open the air inlet hole 13. Among them, a pressure substance 3 for providing pressure to the piston 2 is arranged in the first chamber 11 to drive the piston 2 to close the air inlet hole 13. An air vent hole 15 communicating with the first chamber 11 and used for evacuating or inflating the first chamber 11 is provided on the housing 1.

[0036] The housing 1 is the main body of the absolute pressure valve 100, which can play a role in supporting and protecting. The piston 2 is movably arranged in the housing 1. The housing 1 has a first chamber 11 and a second chamber 12. The first chamber 11 and the second chamber 12 are isolated from each other. The second chamber 12 is used for pressure release. The piston 2 is at least partially arranged in the second chamber 12, and the piston 2 is used to control pressure release.

[0037] The movement of the piston 2 can switch the opening and closing of the air inlet hole 13. During normal operation, the piston 2 closes the air inlet hole 13. The air inlet hole 13 is isolated from the second chamber 12, preventing helium from flowing out of the air inlet hole 13 and improving the reliability of the operation. When pressure release is required, the piston 2 opens the air inlet hole 13. The air inlet hole 13 is communicated with the second chamber 12. Helium flows into the second chamber 12 through the air inlet hole 13 and is discharged from the air vent hole 14 through the second chamber 12, thus completing pressure release. When the pressure release is completed, the piston 2 closes the air inlet hole 13. The air inlet hole 13 is isolated from the second chamber 12, preventing helium from continuing to flow out through the air inlet hole 13.

[0038] The pressure medium 3 arranged in the first chamber 11 provides pressure to the piston 2, so that the piston 2 has a pre-tightening force to close the air inlet hole 13. The normal state of the piston 2 is to close the air inlet hole 13. When the pressure inside the superconducting magnet system rises to be greater than the pressure exerted by the pressure medium 3 on the piston 2, the piston 2 is driven to move and open the air inlet hole 13, and helium can be vented out through the air inlet hole 13. When the pressure inside the superconducting magnet system drops to be less than the pressure exerted by the pressure medium 3 on the piston 2, the piston 2 is driven to move and close the air inlet hole 13 again.

[0039] That is to say, whether to control the absolute pressure valve 100 to release pressure depends on the magnitude of the pressure provided by the pressure medium 3 to the piston 2 and the magnitude of the pressure inside the superconducting magnet system.

[0040] In the embodiment of the present utility model, the pressure medium 3 is arranged in the first chamber 11. The housing 1 is provided with a vent hole 15 communicated with the first chamber 11, and the first chamber 11 can be evacuated or inflated through the vent hole 15. Thus, the first chamber 11 is isolated from the external environment. When pressure release is not carried out, the first chamber 11 maintains a stable environment at a constant pressure. Therefore, the pressure medium 3 in the first chamber 11 is not affected by the external environmental pressure, and the pressure medium 3 stably exerts a fixed pressure on the piston 2.

[0041] In the related art, a pressure relief device uses a one-way valve, and the one-way valve discharges gas through the pressure difference between the inside of the superconducting magnet and the external environment. During land transportation, if passing through high-altitude areas, due to the change in air pressure, a large amount of abnormal exhaust will occur inside the superconducting magnet, resulting in over-discharge. During air transportation, due to the change in pressure or sudden loss of pressure in the cargo plane cabin, the helium gas discharge amount inside the superconducting magnet will also increase.

[0042] However, the absolute pressure valve 100 of the embodiment of the present invention sets the pressure substance 3 in the first chamber 11 isolated from the external environment. Even if the external pressure changes, it will not affect the pressure exerted by the pressure substance 3 on the piston 2, so that the absolute pressure valve 100 can ensure that the helium gas discharge inside the superconducting magnet is not affected by the change of the environmental pressure, and realizes the function of constant-pressure exhaust.

[0043] Optionally, the first chamber 11 can be evacuated through the vent hole 15, so that the first chamber 11 is constructed as a vacuum chamber. The pressure substance 3 will not be affected by pressure in the first chamber 11, and the pressure exerted by the pressure substance 3 on the piston 2 is stable and unchanged. Alternatively, optionally, the first chamber 11 can be inflated through the vent hole 15. The air pressure in the first chamber 11 is stable and not affected by the external environmental air pressure, and the pressure exerted by the pressure substance 3 on the piston 2 is stable and unchanged.

[0044] According to the absolute pressure valve 100 of the embodiment of the present invention, by setting the pressure substance 3 in the first chamber 11 isolated from the external environment, even if the external pressure changes, it will not affect the pressure exerted by the pressure substance 3 on the piston 2, so that the absolute pressure valve 100 can ensure that the helium gas discharge inside the superconducting magnet is not affected by the change of the environmental pressure, and realizes the function of constant-pressure exhaust. After the pressure inside the superconducting magnet system reaches a certain value, the absolute pressure valve 100 automatically opens to release the pressure to protect the safety of the superconducting magnet system; when the pressure drops to the specified pressure, the absolute pressure valve 100 can automatically close to reduce the loss of helium gas in the superconducting magnet system. It can not only achieve safety but also realize unattended automatic control, effectively realizing the stability, high efficiency and safety of the discharge and closing functions.

[0045] In some embodiments of the present invention, as Figure 1 shown, the pressure substance 3 is an elastic member 3a and is supported between the housing 1 and the piston 2. The first chamber 11 is constructed as a vacuum chamber through the vent hole 15.

[0046] The first chamber 11 is a vacuum chamber, and there is no air pressure acting on the elastic member 3a or the piston 2 in the first chamber 11, so that the piston 2 is only subjected to the elastic force from the elastic member 3a, and the change of the external pressure will not affect the pressure exerted by the elastic member 3a on the piston 2, realizing the function of constant-pressure exhaust.

[0047] And when the movement of the piston 2 affects the volume of the first chamber 11, since the first chamber 11 is a vacuum chamber, the volume change of the first chamber 11 will not generate additional pressure, making the pressure applied to the piston 2 more stable and consistent.

[0048] It should be noted that when the piston 2 is pushed up and the spring is stretched or compressed, the elastic force exerted by the spring will change. However, the elastic force exerted by the spring length when the spring drives the piston 2 to close the air inlet 13 always remains unchanged. Therefore, it can be regarded that the elastic member 3a exerts a stable elastic force on the piston 2.

[0049] The working process of the absolute pressure valve 100 in some embodiments of the present invention will be briefly described below.

[0050] Set the opening pressure and closing pressure of the air inlet 13 as F0, and the magnitude of the elastic force exerted by the elastic member 3a on the piston 2 is F0. It can be understood that the elastic force here refers to the elastic force exerted by the spring length of the elastic member 3a in the normal working state when driving the piston 2 to close the air inlet 13.

[0051] The pressure inside the superconducting magnet is P, and the pressure-receiving area is S. Therefore, the force exerted on the piston 2 inside the superconducting magnet is F = P * S. When the pressure F inside the superconducting magnet is lower than F0, the piston 2 closes the air inlet 13; when the pressure inside the superconducting magnet increases and the pressure F is greater than F0, the piston 2 is driven to open the air inlet 13.

[0052] Therefore, whether the absolute pressure valve 100 of the embodiment of the present invention is opened or not is independent of the atmospheric pressure, realizing the function of opening and closing at absolute pressure.

[0053] According to the absolute pressure valve 100 of the embodiment of the present invention, by replacing the elastic member 3a with different elastic forces, the pressure for opening or closing the absolute pressure valve 100 can be changed, which can improve the application range of the absolute pressure valve 100.

[0054] In some embodiments of the present invention, as Figure 1 shown, the elastic member 3a is a spring, and the structure of the spring is simple and can save the manufacturing cost of the absolute pressure valve 100.

[0055] The spring is any one of a compression spring, a torsion spring, a coil spring, a gas spring, a torsion bar spring, a wave spring, a disc spring or an elastic bellows.

[0056] In some other embodiments of the present invention, as Figure 2 shown, the pressure medium 3 is a pressure gas, and the pressure gas is injected into the first chamber 11 through the vent hole 15.

[0057] The first chamber 11 is filled with pressurized gas, and the pressurized gas provides pressure to the piston 2 to drive the piston 2 to close the air inlet hole 13. The first chamber 11 is isolated from the external environment, and the change of the external pressure will not affect the pressure exerted by the pressurized gas on the piston 2, realizing the function of constant-pressure exhaust.

[0058] It should be noted that when the piston 2 moves and causes a change in the volume of the first chamber 11, the pressure exerted by the pressurized gas will change. However, the pressure exerted by the pressurized gas when the piston 2 closes the air inlet hole 13 always remains unchanged. Therefore, it can be regarded that a stable pressure of a certain magnitude is exerted on the piston 2 by the pressurized gas.

[0059] The working process of the absolute pressure valve 100 in some embodiments of the present invention is briefly described below.

[0060] The opening pressure and closing pressure of the air inlet hole 13 are set to F0, and the magnitude of the pressure exerted by the pressurized gas on the piston 2 is F0. It can be understood that the pressure here refers to the pressure exerted by the pressurized gas that drives the piston 2 to close the air inlet hole 13 when the absolute pressure valve 100 is in the normal working state and the first chamber 11 is in the normal size state.

[0061] The pressure inside the superconducting magnet is P, and the pressure-receiving area is S. Therefore, the force on the piston 2 inside the superconducting magnet is F = P * S. When the pressure F inside the superconducting magnet is lower than F0, the piston 2 closes the air inlet hole 13; when the pressure inside the superconducting magnet increases and the pressure F is greater than F0, the piston 2 is driven to open the air inlet hole 13.

[0062] Therefore, whether the absolute pressure valve 100 of the embodiment of the present invention is opened or not has nothing to do with the atmospheric pressure, realizing the function of opening and closing at absolute pressure.

[0063] According to the absolute pressure valve 100 of the embodiment of the present invention, by filling the first chamber 11 with pressurized gas of different pressures, the pressure for opening or closing the absolute pressure valve 100 can be changed, and the application range of the absolute pressure valve 100 can be improved.

[0064] In still some other embodiments of the present invention, the pressure substance 3 includes an elastic member 3a and pressurized gas. The elastic member 3a is supported between the housing 1 and the piston 2, and the pressurized gas is injected into the first chamber 11 through the ventilation hole 15.

[0065] The first chamber 11 is filled with pressurized gas, and the pressurized gas provides pressure to the piston 2. At the same time, the elastic force of the elastic member 3a acts on the piston 2. The first chamber 11 is isolated from the external environment, and the change of the external pressure will not affect the pressures exerted on the piston 2 by the pressurized gas and the elastic member 3a, realizing the function of constant-pressure exhaust.

[0066] In some embodiments of the present invention, such as Figure 1As shown, the absolute pressure valve 100 further includes a sealing plug 4. The sealing plug 4 is arranged inside the housing 1. The first chamber 11 and the second chamber 12 are separated on both sides of the sealing plug 4. The piston 2 passes through the sealing plug 4 along the arrangement direction of the first chamber 11 and the second chamber 12, and is movable relative to the sealing plug 4 along the passing direction.

[0067] The piston 2 moves inside the housing 1 along the axial direction of the piston. The piston 2 and the sealing plug 4 are hermetically connected to each other to isolate the first chamber 11 and the second chamber 12 located on both sides of the sealing plug 4 from each other. The first chamber 11 and the second chamber 12 are respectively located at both axial ends of the piston 2, and the piston 2 can move axially relative to the sealing plug 4.

[0068] The pressure substance 3 arranged in the first chamber 11 provides pressure to the piston 2, applying a pressure to the piston 2 with a tendency to move from the first chamber 11 to the second chamber 12, and the piston 2 closes the air inlet hole 13. When the pressure inside the superconducting magnet system rises to be greater than the pressure applied by the pressure substance 3 to the piston 2, the piston 2 is driven to move from the second chamber 12 to the first chamber 11 direction, and the piston 2 moves to open the air inlet hole 13, and helium can be released from the air inlet hole 13. When the pressure inside the superconducting magnet system drops to be less than the pressure applied by the pressure substance 3 to the piston 2, the piston 2 is driven to move from the first chamber 11 to the second chamber 12 direction to close the air inlet hole 13 again.

[0069] In some embodiments of the present invention, as Figure 1 shown, one end of the piston 2 away from the second chamber 12 has a mounting platform 21 protruding towards the first chamber 11, and the pressure substance 3 is a spring and is sleeved on the mounting platform 21.

[0070] When the piston 2 closes the air inlet hole 13, at least part of the mounting platform 21 is located inside the first chamber 11. The spring is sleeved on the mounting platform 21, which can improve the mounting stability of the spring, and the mounting platform 21 can also play a guiding role in the deformation of the spring, reduce the situation of spring deformation, and improve the working reliability of the absolute pressure valve 100.

[0071] In some other embodiments of the present invention, the pressure substance 3 is a pressure gas. As Figure 2 shown, the pressure gas is injected into the first chamber 11 through the ventilation hole 15. One end of the piston 2 away from the second chamber 12 has a receiving groove 22 recessed towards the second chamber 12, and the receiving groove 22 communicates with the first chamber 11.

[0072] When the pressure inside the superconducting magnet system rises to be greater than the pressure exerted by the pressure medium 3 on the piston 2, the piston 2 is driven to move from the second chamber 12 towards the first chamber 11, and at least a part of the end of the piston 2 facing the first chamber 11 will enter the first chamber 11. It can be understood that since the first chamber is isolated from the external environment, the piston occupying the space of the first chamber will cause the volume of the first chamber to decrease, and then the pressure exerted by the pressurized gas on the piston will increase, resulting in a large change in the force on the piston. The piston is prone to reciprocating motion and increased wear.

[0073] Therefore, in the embodiment of the present utility model, the absolute pressure valve 100 is provided with a receiving groove 22 at the end of the piston 2 facing the first chamber 11, which can reduce the space occupied by the piston 2 in the first chamber 11, reduce the influence on the volume of the first chamber 11, make the pressure exerted by the pressurized gas on the piston 2 more stable, and is beneficial to reducing the wear of the piston 2.

[0074] And by providing the receiving groove 22, the volume of the piston 2 can also be reduced, saving the manufacturing cost of the piston 2.

[0075] In some embodiments of the present utility model, as Figure 1 shown, the piston 2 includes a piston shaft 2a and a sealing boss 2b. The piston shaft 2a passes through the sealing plug 4, and the first end of the piston shaft 2a extends into the second chamber 12. The sealing boss 2b is arranged around the first end and is blocked in the second chamber 12 by the sealing plug 4 to limit the extreme position of the piston shaft 2a moving along the direction from the second chamber 12 to the first chamber 11 and prevent the piston shaft 2a from detaching from the sealing plug 4 along the direction from the second chamber 12 to the first chamber 11. The air inlet hole 13 is arranged opposite to the first end, and a first sealing ring 5 is arranged on the housing 1 around the air inlet hole 13. When the first end closes the air inlet hole 13, the sealing boss 2b is in sealing cooperation with the first sealing ring 5.

[0076] As Figure 1 shown, the cross-sectional area of the piston 2 at the sealing boss 2b is larger than the cross-sectional area of other parts of the piston 2. The first end of the piston 2 is provided with a sealing boss 2b and is used to close the air inlet hole 13. By providing the sealing boss 2b, the contact area between the piston 2 and the housing 1 can be increased, the area where the first sealing ring 5 can be arranged can be enlarged, and the selection and arrangement of the first sealing ring 5 are larger, which is beneficial to improving the sealing effect of the piston 2 on the air inlet hole 13.

[0077] Moreover, by providing the sealing boss 2b, it can also limit the position of the piston 2. The piston shaft 2a passes through the sealing plug 4, and the sealing boss 2b increases the cross-sectional area of the piston 2 at the first end, so that the first end of the piston 2 cannot pass through the sealing plug 4. Thus, the first end of the piston 2 can be restricted within the second chamber 12 to limit the movement of the piston 2. By providing the sealing boss 2b, the movement reliability of the piston 2 can be improved, preventing the piston 2 from disengaging from the second chamber 12 and enhancing the working reliability of the absolute pressure valve 100.

[0078] In some embodiments of the present invention, a second sealing ring 6 is provided at the position of the sealing plug 4 around the piston shaft 2a. The second sealing ring 6 is in sealing cooperation with the outer peripheral surface of the piston shaft 2a. In the axial direction, the acting force of the second sealing ring 6 on the piston shaft 2a is equal to the acting force of the first sealing ring 5 on the piston shaft 2a.

[0079] As Figure 1 shown, the second chamber 12 communicates with the external environment, and the atmospheric pressure of the external environment acts on the piston 2. There are acting forces in two directions in the axial direction of the piston 2, namely the acting force from the first chamber 11 to the second chamber 12 and the acting force from the second chamber 12 to the first chamber 11. By providing the first sealing ring 5 and the second sealing ring 6, it can prevent the atmospheric pressure from driving the piston 2 to move, enhancing the working reliability of the absolute pressure valve 100.

[0080] By designing the first sealing ring 5 and the second sealing ring 6 such that in the axial direction, the acting force of the second sealing ring 6 on the piston shaft 2a is equal to the acting force of the first sealing ring 5 on the piston shaft 2a, the piston 2 will not be driven to move by the atmospheric pressure. It can achieve that the atmospheric pressure does not generate an additional force on the piston 2, so that the external atmospheric disturbance does not affect the function of the absolute pressure valve 100, achieving the absolute pressure opening and discharging function.

[0081] In some embodiments of the present invention, the first sealing ring 5 and the second sealing ring 6 have the same size.

[0082] In some embodiments of the present invention, as Figure 1 shown, there are multiple second sealing rings 6, and the multiple second sealing rings 6 are arranged at intervals along the axial direction of the piston shaft 2a.

[0083] By providing two or more sealing structures, the mutual isolation between the first chamber 11 and the second chamber 12 is realized, thus achieving the absolute pressure opening and discharging function.

[0084] In some embodiments of the present utility model, the housing 1 includes a housing body 1a and a sealing flange 1b. The housing body 1a and the sealing flange 1b are fixedly connected, and a first chamber 11 and a second chamber 12 are defined between the housing body 1a and the sealing flange 1b. The sealing flange 1b is connected to the container of the superconducting magnet system, and an air inlet hole 13 is provided on the sealing flange 1b. The piston 2 abuts against the sealing flange 1b to close the air inlet hole 13. An air release hole 14 and a ventilation hole 15 are provided on the housing body 1a, and the sealing plug 4 is fixedly connected to the housing body 1a to divide the interior of the housing 1 into a first chamber 11 and a second chamber 12.

[0085] In some embodiments of the present utility model, after the ventilation hole 15 provided on the housing 1 is used for evacuating or inflating the first chamber 11, the ventilation hole 15 is sealed to isolate the first chamber 11 from the outside.

[0086] Next, the superconducting magnet system according to the second aspect embodiments of the present utility model will be described.

[0087] The superconducting magnet system according to the embodiments of the present utility model includes the absolute pressure valve 100 according to the first aspect embodiments of the present utility model.

[0088] The superconducting magnet system according to the embodiments of the present utility model, by providing the absolute pressure valve 100 of the first aspect of the present utility model, enables the helium gas discharge inside the superconducting magnet system not to be affected by the change of the ambient pressure, and realizes the function of constant pressure exhaust.

[0089] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present utility model 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 thus should not be construed as a limitation to the present utility model.

[0090] 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 specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, "a plurality" means two or more unless otherwise specifically defined.

[0091] In the present utility model, unless otherwise clearly defined and limited, terms such as "installation", "connection", "linkage", "fixation", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral one; it may be a mechanical connection, an electrical connection, or a communication connection; it may be a direct connection, or an indirect connection through an intermediate medium, and it may be the internal connection between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0092] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may mean 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", "beneath" and "underneath" the second feature may mean 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.

[0093] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. means 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 present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described 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.

[0094] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. An absolute pressure valve, characterized in that: include: A shell, wherein the shell has a first chamber and a second chamber, and the shell is provided with an air inlet and an air outlet communicating with the second chamber; a piston, the piston being movably disposed in the housing and at least partially extending into the second chamber to close or open the air inlet; The first chamber is provided with a pressure material for providing pressure to the piston so as to drive the piston to close the air inlet hole, and the outer shell is provided with an air vent which is connected with the first chamber and is used to evacuate or inflate the first chamber.

2. The absolute pressure valve according to claim 1, characterized in that: The pressure material is an elastic member and is supported between the housing and the piston; the first chamber is configured as a vacuum chamber through a vent hole.

3. The absolute pressure valve according to claim 2, characterized in that: The elastic member is a spring, and the spring is any one of a compression spring, a torsion spring, a coil spring, a gas spring, a torque spring, a wave spring, a butterfly spring or an elastic bellows.

4. The absolute pressure valve according to claim 1, characterized in that: The pressure substance is a pressure gas, and the pressure gas is injected into the first chamber through the vent hole.

5. The absolute pressure valve according to claim 1, characterized in that: Also includes: A sealing plug is arranged in the shell, the first chamber and the second chamber are separated on both sides of the sealing plug, and the piston is penetrated in the sealing plug along the arrangement direction of the first chamber and the second chamber so as to be movable relative to the sealing plug along the penetration direction.

6. The absolute pressure valve according to claim 5, characterized in that: One end of the piston away from the second chamber has a mounting platform protruding toward the first chamber, and the pressure material is a spring and is sleeved on the mounting platform.

7. The absolute pressure valve according to claim 5, characterized in that: The pressure material is pressurized gas, which is injected into the first chamber through the vent hole. The end of the piston away from the second chamber has a receiving groove recessed toward the second chamber, and the receiving groove is connected to the first chamber.

8. The absolute pressure valve according to any one of claims 5 to 7, characterized in that: The piston comprises a piston shaft and a sealing boss, wherein the piston shaft is inserted into the sealing plug, and a first end of the piston shaft extends into the second chamber, and the sealing boss is arranged around the first end and is blocked by the sealing plug in the second chamber; The air inlet hole is arranged opposite to the first end, and the housing is provided with a first sealing ring arranged around the air inlet hole. When the air inlet hole is closed by the first end, the sealing boss is sealed and matched with the first sealing ring.

9. The absolute pressure valve according to claim 8, characterized in that: A second sealing ring is arranged around the piston shaft of the sealing plug. The second sealing ring is sealed with the outer peripheral surface of the piston shaft. In the axial direction, the force exerted by the second sealing ring on the piston shaft is consistent with the force exerted by the first sealing ring on the piston shaft.

10. A superconducting magnet system, characterized in that: Comprising the absolute pressure valve according to any one of claims 1-9.

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