Low-temperature container of superconducting magnet and superconducting magnet

Abstract

The utility model provides a superconducting magnet low-temperature container and a superconducting magnet, the superconducting magnet low-temperature container comprises a cooling container and a discharge assembly, the cooling container is provided with an accommodating space, and the accommodating space can accommodate a superconducting coil and a coolant thermally coupled with the superconducting coil; the discharge assembly is arranged on the outer side of the cooling container and comprises an exhaust pipeline, the exhaust pipeline is connected with a discharge port of the cooling container, and a control valve and a rupture disk safety device are arranged on the exhaust pipeline; the control valve is a magnetic control device, and the coolant in the containing space can escape to the outside through the discharge port, the rupture disk safety device and the control valve in sequence. According to the low-temperature container of the superconducting magnet, when the superconducting coil is quenched to cause blasting of the rupture disk safety device, the magnetic field of the quenched superconducting coil is attenuated after releasing for a period of time, and when the helium pressure is lower than the opening pressure of the control valve, the control valve is closed; helium cannot be continuously discharged through the pipeline where the rupture disk safety device is located.

Description

Technical Field

[0001] The present application belongs to the technical field of superconducting magnets, and in particular, relates to a low-temperature container of a superconducting magnet and a superconducting magnet. Background Art

[0002] At present, on the pressure vessels of most superconducting magnets, see Figure 1 , usually a safety valve 126 and a bursting disc safety device 122 are provided at the same time. When the superconducting magnet quenches (loses superconductivity), the safety valve 126 opens before the bursting disc safety device 122 and releases high-pressure helium, that is, the opening pressure of the safety valve 126 is lower than the bursting pressure of the bursting disc safety device 122, so that frequent replacement of the bursting disc safety device 122 can be avoided. However, even so, the bursting disc safety device 122 will inevitably burst due to high current quench in many cases. At this time, the pressure vessel is equivalent to being connected to the atmosphere. If a new bursting disc safety device 122 cannot be replaced in time, the liquid helium in the magnet will evaporate quickly and be lost, resulting in a substantial increase in the quench cost. If the liquid helium in the magnet completely evaporates and the superconducting coil warms up, it needs to be cooled again, which sometimes even affects the superconducting performance of the coil, which is often unacceptable.

[0003] To solve the above problems, the existing technology usually connects a safety valve in series behind the passage of the bursting disc. When the timeout is exceeded, the pressure of the magnet rises rapidly until the bursting disc bursts. Then the safety valve behind the passage of the bursting disc is opened to continuously release helium. When the pressure inside the pressure vessel drops below the opening pressure of the series safety valve, the safety valve is closed, that is, the passage of the bursting disc is closed to prevent the continuous loss of liquid helium. However, this series safety valve will produce a back pressure effect on the bursting disc, resulting in fluctuations in the bursting pressure of the bursting disc, which may prevent it from bursting normally under the design pressure conditions, affecting safety. Utility Model Content

[0004] The purpose of the embodiments of the present application is to provide a low-temperature container for a superconducting magnet and a superconducting magnet, so as to solve the technical problem in the prior art that a safety valve is connected in series behind the passage of the bursting disc, and the back pressure generated by the safety valve on the bursting disc after the superconducting magnet is excited may cause the bursting disc to fail to explode normally under the design pressure conditions.

[0005] To achieve the above purpose, the technical solution adopted in this application is:

[0006] A first aspect of the present application provides a cryogenic container for a superconducting magnet, comprising:

[0007] A cooling container having an accommodation space capable of accommodating the superconducting coil and a coolant thermally coupled to the superconducting coil;

[0008] A discharge assembly is arranged outside the cooling container, the discharge assembly comprises an exhaust pipeline, the exhaust pipeline is connected to the discharge port of the cooling container, and a control valve and a bursting disc safety device are arranged on the exhaust pipeline;

[0009] The control valve is a magnetic control device, and the coolant in the accommodating space can escape to the outside through the discharge port, the bursting disc safety device and the control valve in sequence.

[0010] After the superconducting coil is excited, a magnetic field is generated. Since the control valve is a magnetic control device, the control valve can be in an open state under the magnetic field environment of the superconducting coil, so that the control valve will not have an impact on the back pressure of the bursting disc safety device; when the superconducting coil "quenches" and causes the bursting disc safety device to explode, after a period of discharge, the magnetic field of the superconducting coil after the quench has decayed, and the control valve is in a non-magnetic field environment. When the helium pressure is lower than the opening pressure of the control valve, the control valve is closed, that is, the rear pipeline of the bursting disc safety device is closed, and helium will not continue to be discharged through the pipeline where the bursting disc safety device is located.

[0011] In some implementations, the control valve and the bursting disc safety device are arranged in series, and the bursting disc safety device is located on a side close to the cooling container.

[0012] That is, the control valve is arranged in the pipeline on the rear side of the closed bursting disc safety device, and the control valve is opened when the superconducting coil is in the superconducting state, so that the control valve will not have the influence of back pressure on the bursting disc.

[0013] In some implementations, a control valve includes a valve body of elastically driven pressure control and a magnetic portion, wherein the magnetic portion is disposed on a valve core of the valve body.

[0014] The control valve has a simple structure. By arranging a magnetic part on the valve core, the control valve can be opened in the presence of a magnetic field, and the control valve can be closed under the action of its own elastic force in the absence of a magnetic field.

[0015] In some implementations, the magnetic portion is a permanent magnetic material, and the magnetic portion can move under the action of an external magnetic field to control the conduction state of the control valve.

[0016] When the control valve can be automatically opened when the superconducting magnet generates a magnetic field environment, the structure is simple and the reliability is good.

[0017] In some implementations, the magnetic part is an energized coil, and the discharge assembly also includes a switching power supply and a magnetic field sensing device. The switching power supply, the magnetic field sensing device and the magnetic part are electrically connected. The magnetic field sensing device is used to connect the circuit between the switching power supply and the magnetic part when a magnetic field is detected, thereby driving the control valve to operate to control the control valve to be in a conducting state.

[0018] When the control valve can be automatically opened when the superconducting magnet generates a magnetic field environment, the structure is simple, the reliability is good, and precise control can be achieved.

[0019] In some implementations, the control valve further includes a preload adjustment structure for adjusting the opening pressure of the control valve.

[0020] The preload force of the control valve is adjusted by the preload force adjustment structure, so that the control valve can be opened under different magnetic field environments, so as to make reasonable adjustments according to actual needs.

[0021] In some implementations, the cryogenic container further includes a service tower, which is disposed on the cooling container and is connected to the accommodating space to form a discharge port.

[0022] The service tower is provided with a discharge assembly, and may also be provided with a refrigerator for a superconducting magnet, etc.

[0023] In some implementations, the exhaust pipeline forms more than one first discharge branch, and the first discharge branch is provided with a control valve and a bursting disc safety device.

[0024] The exhaust pipeline forms more than one first discharge branch. A reasonable number of first discharge branches can be set according to actual conditions to meet the usage requirements in different scenarios.

[0025] In some implementations, the exhaust pipeline further includes a second discharge branch, on which a safety valve is disposed; and the first discharge branch and the second discharge branch are connected in parallel.

[0026] By providing a second discharge branch and a safety valve, the probability of bursting disc explosion is reduced, thus saving costs.

[0027] A second aspect of the present application provides a superconducting magnet, comprising a cryogenic container for the superconducting magnet provided by any of the above technical solutions.

[0028] Through the above technical solution, since the superconducting magnet includes the above-mentioned cryogenic container, it at least has all the beneficial effects of the cryogenic container, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0030] Figure 1 It is a cross-sectional schematic diagram of an existing superconducting magnet;

[0031] Figure 2 A cross-sectional view of a superconducting magnet provided in an embodiment of the present application Figure 1 ;

[0032] Figure 3 A cross-sectional view of a superconducting magnet provided in an embodiment of the present application Figure 2 ;

[0033] Figure 4 A cross-sectional schematic diagram of a control valve provided in an embodiment of the present application;

[0034] Figure 5 A schematic diagram of a discharge assembly provided in an embodiment of the present application (the control valve is in a closed state);

[0035] Figure 6 A schematic diagram of a discharge assembly provided in an embodiment of the present application (the control valve is in an open state);

[0036] Figure 7 A schematic diagram of a discharge assembly provided in accordance with another embodiment of the present application.

[0037] Among them, the reference numerals in the figure are:

[0038] 1- cryogenic container; 2- superconducting coil; 3- cryogenic container assembly; 4- refrigerator; 5- heating device;

[0039] 11-cooling container; 12-discharge assembly; 13-service tower;

[0040] 111- discharge port;

[0041] 121-exhaust pipeline; 122-bursting disc safety device; 123-control valve; 124-power supply; 125-magnetic field induction device; 126-safety valve;

[0042] 1211-first discharge branch; 1212-second discharge branch; 1213-air inlet; 1214-exhaust outlet;

[0043] 1231-magnetic part; 1232-valve core; 1233-adjusting screw; 1234-nut; 1235-valve body; 1236-elastic part; 1237-sealing part; 1238-sealing surface; 1239-dust cover. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, but cannot be understood as limiting the present application.

[0045] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "top", "bottom", "inside", "outside", "up", "down", "left", "right", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply 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.

[0046] In order to clearly describe the technical solution of the present application, the words "first", "second" and the like are used to distinguish the same or similar items with substantially the same functions and effects. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not necessarily limit the difference.

[0047] In this application, unless otherwise clearly specified and limited, the terms "connected", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0048] In this application, "and / or" is only a description of the association relationship of associated objects, indicating that there can be three relationships; for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0049] It should be noted that, in this application, words such as "in one embodiment", "exemplarily", "for example", etc. are used to indicate examples, illustrations or descriptions. Any embodiment or design described in this application as "in one embodiment", "exemplarily", "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "in one embodiment", "exemplarily", "for example", etc. is intended to present related concepts in a specific way.

[0050] The cryogenic container of the superconducting magnet provided in this embodiment is described in detail below with reference to the accompanying drawings.

[0051] A cryogenic container 1 for a superconducting magnet comprises a cooling container 11 and a discharge assembly 12, wherein the cooling container 11 has a containing space, the containing space can contain a superconducting coil 2 and a coolant thermally coupled to the superconducting coil 2; the discharge assembly 12 is arranged on the outside of the cooling container 11, the discharge assembly 12 comprises an exhaust pipeline 121, the exhaust pipeline 121 is connected to a discharge port 111 of the cooling container 11, and a control valve 123 and a bursting disc safety device 122 are arranged on the exhaust pipeline 121; the control valve 123 is a magnetic control device, and the coolant in the containing space can escape to the outside through the discharge port 111, the bursting disc safety device 122 and the control valve 123 in sequence.

[0052] In this embodiment, the coolant in the accommodating space can escape to the outside through the discharge port 111 , the bursting disc safety device 122 and the control valve 123 in sequence, that is, the control valve 123 is arranged at the rear side of the pipeline of the bursting disc safety device 122 .

[0053] After the superconducting coil 2 is excited, the superconducting coil 2 has a constant current and can generate a strong magnetic field. In this embodiment, by setting the control valve 123 as a magnetic control device, the superconducting coil 2 generates a magnetic field when it is in a superconducting state, and the control valve 123 can be in an open state. The operation of the control valve 123 is as follows:

[0054] (1) Normal working state of superconducting magnet

[0055] The superconducting coil 2 has a constant current and can generate a strong magnetic field. The control valve 123 is in an open state. Since the control valve 123 is in an open state, the control valve 123 will not generate a back pressure effect on the bursting disc safety device 122, thereby avoiding the situation in the prior art where a safety valve is connected in series behind the passage of the bursting disc. After the superconducting magnet is excited, the back pressure generated by the safety valve on the bursting disc may cause the bursting disc to fail to explode normally under the design pressure conditions.

[0056] (2) The superconducting coil 2 is in a "quenched" state.

[0057] When the superconducting coil 2 of the superconducting magnet "quenches", that is, when the superconducting coil 2 loses its superconducting properties, the inductive energy stored in the superconducting coil 2 is released instantly, heating the liquid helium inside the cryogenic container 1 to cause it to vaporize rapidly, and the pressure inside the superconducting magnet continues to increase. When the helium pressure further increases to the bursting pressure of the bursting disc safety device 122, the bursting disc safety device 122 explodes, and at this time, the high-pressure gas is discharged to the external environment through the bursting disc safety device 122 and the control valve 123 at the same time.

[0058] After a period of discharge, the magnetic field of the superconducting coil 2 has decayed completely after the quenching, and the control valve 123 is in a non-magnetic field environment. When the helium pressure is lower than the opening pressure of the control valve 123, the control valve 123 is closed, that is, the rear pipeline of the bursting disc safety device 122 is closed, and the helium will not continue to be discharged through the pipeline where the bursting disc safety device 122 is located.

[0059] The discharge assembly 12 provided in this embodiment is preferably, but not limited to, applied to superconducting magnets, and is also applicable to the fields of chemical engineering, machinery, etc., such as certain equipment or systems that are sensitive to magnetic fields.

[0060] Specifically, when the superconducting coil 2 has just been magnetized, the magnetic field generated by the superconducting coil 2 is called a full magnetic field, and the control valve 123 can be opened only under the full magnetic field state, or the control valve 123 is still in an open state under a non-full magnetic field (the superconducting coil 2 loses superconductivity, causing the magnetic field to attenuate).

[0061] In this embodiment, a suitable control valve 123 can be selected so that the control valve 123 opens under different magnetic field environments, or the opening pressure of the control valve 123 can be changed by adjusting the control valve 123 so that the control valve 123 can open under different magnetic field environments.

[0062] In one embodiment, the control valve 123 and the bursting disc safety device 122 are arranged in series, and the bursting disc safety device 122 is located on a side close to the cooling container 11 .

[0063] See also Figure 2 and Figure 3 , showing the control valve 123 and the bursting disc safety device 122. In this embodiment, the control valve 123 is arranged at the rear side of the bursting disc safety device 122 pipeline, and the structure of the discharge assembly 12 is simplified.

[0064] In one embodiment, the control valve 123 includes a valve body of elastically driven pressure control and a magnetic portion 1231 , wherein the magnetic portion 1231 is disposed on a valve core 1232 of the valve body.

[0065] The magnetic part 1231 interacts with the magnetic field generated by the superconducting coil 2. When the magnetic part 1231 is acted upon by the magnetic field, it needs to overcome the elastic force of the control valve 123 itself, that is, when the magnetic force on the magnetic part 1231 is greater than the elastic force, the valve core 1232 opens and the control valve 123 is in the on state; when the magnetic force on the magnetic part 1231 is less than the elastic force, the valve core 1232 does not open and the control valve 123 is in the off state.

[0066] In addition, by selecting appropriate parameters such as materials and shapes, and arranging appropriate orientations, when the superconducting coil 2 generates a magnetic field, the direction in which the magnetic force on the magnetic part 1231 is applied in the magnetic field is the same as the direction in which the valve core 1232 opens, so that the control valve 123 can automatically "open" under the action of the magnetic field environment.

[0067] The control valve 123 provided in this embodiment has a simple structure, and the switching state of the control valve 123 can be controlled by the interaction between the magnetic part 1231 and the magnetic field generated by the superconducting coil 2 .

[0068] In one embodiment, the magnetic portion 1231 is made of a permanent magnetic material, and the magnetic portion 1231 can move under the action of an external magnetic field to control the conduction state of the control valve 123 .

[0069] See also Figure 4 , schematically shows the magnetic part 1231 disposed in the valve core 1232. The magnetic material is a material that can respond to a magnetic field in some way. When the superconducting magnet generates a magnetic field, the magnetic part 1231 can be subjected to a magnetic force in the magnetic field.

[0070] In this embodiment, when the superconducting coil 2 generates a magnetic field environment, the control valve 123 can be automatically opened, the structure is simple, the reliability is good, and no additional control signal or drive device is required.

[0071] In this embodiment, the following three situations are included: first, the entire valve core 1232 is made of magnetic material, that is, the entire valve core 1232 serves as the magnetic part 1231; second, the valve core 1232 is not made of magnetic material, and the magnetic part 1231 is installed on the valve core 1232; third, the valve core 1232 and the magnetic part 1231 are both made of magnetic material, but there are differences in the specific materials.

[0072] In the example where the entire valve core 1232 is used as the magnetic part 1231, when the superconducting coil 2 generates a magnetic field, the entire valve core 1232 may be subjected to magnetic force in the magnetic field. At this time, the material of the valve core 1232 may be ferromagnetic materials such as carbon steel, silicon steel, and magnetic steel.

[0073] In the example where the valve core 1232 and the magnetic part 1231 are made of different materials, the magnetic part 1231 can be provided to be detachably connected to the valve core 1232, such as by snap-fitting or threaded connection, or the magnetic part 1231 can be provided to be non-detachably connected to the valve core 1232, such as by welding.

[0074] In the example where the valve core 1232 and the magnetic portion 1231 are made of different materials, the material of the magnetic portion 1231 may be a ferromagnetic material such as carbon steel, silicon steel, or magnetic steel.

[0075] In one embodiment, the magnetic part 1231 is an energized coil, and the discharge assembly 12 further includes a switching power supply 124 and a magnetic field sensing device 125. The switching power supply 124, the magnetic field sensing device 125 and the magnetic part 1231 are electrically connected. The magnetic field sensing device 125 is used to connect the circuit between the switching power supply 124 and the magnetic part 1231 when a magnetic field is detected, thereby driving the control valve 123 to operate to control the control valve 123 to be in a conducting state.

[0076] See also Figure 7 , schematically shows a switching power supply 124 and a magnetic field sensor 125. The magnetic field sensor 125 detects the magnetic field or the magnetic field strength to control the on / off state of the circuit between the switching power supply 124 and the magnetic part 1231.

[0077] The magnetic part 1231 is a coil with power. When current flows into the magnetic part 1231 , the magnetic part 1231 can generate a magnetic field. The magnetic field generated by the magnetic part 1231 interacts with the magnetic field generated by the superconducting coil 2 to generate a magnetic force acting on the magnetic part 1231 .

[0078] In this embodiment, when the superconducting magnet generates a magnetic field environment, the control valve 123 can be automatically opened, the structure is simple, the reliability is good, and precise control can be achieved.

[0079] Exemplarily, the magnetic field sensing device 125 includes a magnetic field sensor, a controller, and a switch. The magnetic field sensor is a device that can convert various magnetic fields and their changing quantities into electrical signals for output. When the magnetic field sensor detects a magnetic field signal, the magnetic field sensor transmits the signal to the controller, which analyzes the signal. The controller can control the on and off state of the switch. When the controller controls the switch to be turned on, the circuit between the switching power supply 124 and the magnetic part 1231 can be in a conducting state.

[0080] Exemplarily, the magnetic portion 1231 is detachably mounted on the valve core 1232 , such as by snap-fitting, etc.; or, the magnetic portion 1231 is non-detachably mounted on the valve core 1232 , such as by bonding, etc.

[0081] Exemplarily, the valve core 1232 is made of non-magnetic material, or the valve core 1232 is made of magnetic material.

[0082] Preferably, the number of the magnetic parts 1231 is more than one. For example, there are two magnetic parts 1231, and the two magnetic parts 1231 are arranged on the valve core 1232, and the two magnetic parts 1231 are connected in series or in parallel with the switching power supply 124.

[0083] In one embodiment, the control valve 123 further includes a preload adjustment structure for adjusting the opening pressure of the control valve.

[0084] The preload force of the control valve 123 is adjusted by the preload force adjustment structure, so that the control valve 123 can be opened under different magnetic field environments, so as to make reasonable adjustments according to actual needs.

[0085] The structure of the control valve 123 can be as follows: the valve body includes a valve body 1235, an elastic member 1236 and a sealing member 1237, the valve core 1232 is arranged in the valve body 1235, the elastic member 1236 connects the valve core 1232 and the valve body 1235, the valve core 1232 is provided with a sealing member 1237, and the valve body 1235 is provided with a valve body inlet and a valve body outlet, when the sealing member 1237 is squeezed on the sealing surface 1238 of the valve body 1235 under the action of the elastic member 1236, there is no conduction between the valve body inlet and the valve body outlet.

[0086] See also Figure 4 , is a cross-sectional schematic diagram of the control valve 123. The figure schematically shows the valve body 1235, the valve core 1232, the elastic member 1236 and the sealing member 1237.

[0087] The control valve 123 has a simple structure and is a typical pressure control valve, and its opening pressure value is related to the preload force of the elastic member 1236 and the area of ​​the valve core bearing surface. The valve core bearing surface refers to the surface that acts on the valve core 1232 when the fluid enters through the valve body inlet.

[0088] If the pressure for opening the control valve 123 is P1, when the differential pressure between the valve body outlet and the valve body inlet is less than P1, the gas pressure on the valve core 1232 cannot overcome the elastic force of the elastic member 1236, and the valve core 1232 is closed; when the differential pressure between the valve body outlet and the valve body inlet is greater than P1, the gas pressure on the valve core 1232 overcomes the elastic force of the elastic member 1236, the valve core 1232 leaves the sealing surface 1238, and the valve core 1232 opens.

[0089] When the magnetic part 1231 is acted upon by magnetism, it needs to overcome the preload force of the elastic part 1236, that is, when the magnetic force acted upon by the magnetic part 1231 is greater than the preload force of the elastic part 1236, the valve core 1232 opens; when the magnetic force acted upon by the magnetic part 1231 is less than the preload force of the elastic part 1236, the valve core 1232 does not open. In other words, when the magnetic field environment in which the control valve 123 is located is relatively small, although the magnetic part 1231 is acted upon by magnetism, the valve core 1232 may still be in a closed state.

[0090] The preload force of the elastic member 1236 is adjusted by the preload force adjustment structure, so that the control valve 123 can be opened in different magnetic field environments. For example, the preload force of the elastic member 1236 is adjusted so that the control valve 123 can be opened only in a full magnetic field state, or the preload force of the elastic member 1236 is adjusted so that the control valve 123 can still be opened in a non-full magnetic field.

[0091] For example, the preload force of the elastic member 1236 is adjusted by the preload force adjustment structure so that the pressure for opening the control valve 123 is P1, and then the preload force of the elastic member 1236 is adjusted by the preload force adjustment structure so that the pressure for opening the control valve 123 is P2, wherein P2>P1.

[0092] In one embodiment, the preload force adjustment structure includes an adjustment screw 1233 and a nut 1234 . The nut 1234 is disposed outside the valve body 1235 . The adjustment screw 1233 is inserted into the nut 1234 and passes through the valve body 1235 to be connected to the elastic member 1236 .

[0093] See also Figure 4 , showing the adjusting screw 1233 and the nut 1234. Figure 4 In the figure, the nut 1234 is fixed on the top of the valve body 1235, the adjusting screw 1233 is inserted into the nut 1234 and passes through the valve body 1235 to be connected with one end of the elastic member 1236, and the other end of the elastic member 1236 is connected with the valve core 1232, that is, the elastic member 1236 is squeezed between the adjusting screw 1233 and the valve core 1232.

[0094] When it is necessary to increase the opening pressure of the control valve 123, the adjusting screw 1233 is rotated so that the adjusting screw 1233 is screwed inwardly into the valve body 1235 for a certain length. At this time, the elastic member 1236 is further compressed, and the elastic force of the elastic member 1236 on the valve core 1232 increases, thereby increasing the pressure for opening the valve core 1232 and increasing the opening pressure of the control valve 123; when it is necessary to reduce the opening pressure of the control valve 123, the adjusting screw 1233 is rotated so that the adjusting screw 1233 is screwed outwardly from the valve body 1235 for a certain length. At this time, the compression of the elastic member 1236 is reduced, and the elastic force of the elastic member 1236 on the valve core 1232 is reduced, thereby reducing the pressure for opening the valve core 1232 and reducing the opening pressure of the control valve 123.

[0095] The preload force adjustment structure provided in this embodiment has a simple structure and is simple and convenient for adjusting the preload force of the elastic member.

[0096] Preferably, see Figure 4 The control valve 123 further includes a dust cover 1239, which is disposed on the outside of the valve body 1235 and is detachably connected to the valve body 1235. The dust cover 1239 shields the nut 1234 and the end of the adjusting screw 1233 extending outside the valve body 1235 to prevent dust and protect the adjusting screw 1233 and the nut 1234. When the preload force of the elastic member 1236 needs to be adjusted, the dust cover 1239 is removed from the valve body 1235. After the preload force of the elastic member 1236 is adjusted, the dust cover 1239 is installed on the valve body 1235.

[0097] Preferably, a sealing ring is provided between the dust cover 1239 and the valve body 1235 , and the dust cover 1239 and the valve body 1235 are sealed together.

[0098] Preferably, the elastic member 1236 is a spring.

[0099] Preferably, see Figure 4 A receiving groove is provided on the valve core 1232 , and one end of the elastic member 1236 extends into the receiving groove on the valve core 1232 to facilitate the limiting of the elastic member 1236 .

[0100] In one embodiment, the cryogenic container further includes a service tower 13 , which is disposed on the cooling container 11 , and the service tower 13 is connected to the accommodating space to form a discharge port 111 .

[0101] See also Figure 2 , schematically showing the service tower 13. The service tower 13 is not only formed with a discharge port 111, but also can be installed with a refrigerator 4 of a superconducting magnet.

[0102] In one embodiment, the exhaust pipeline 121 forms more than one first discharge branch 1211 , and the first discharge branch 1211 is provided with a control valve 123 and a bursting disc safety device 122 .

[0103] In this embodiment, the exhaust pipe 121 only includes the first discharge branch 1211 (excluding the second discharge branch 1212 described below). Figure 3 , a first discharge branch 1211 is shown. A bursting disc safety device 122 and a control valve 123 are arranged on the first discharge branch 1211. Figure 3 In the figure, the control valve 123 is shown in an open state.

[0104] In this embodiment, the exhaust pipe 121 forms more than one first discharge branch 1211, that is, the number of the first discharge branch 1211 can be as follows: Figure 3 The diagram shows one, but it may also be two or more, and the first discharge branches 1211 are connected in parallel.

[0105] Preferably, the exhaust pipeline 121 forms an air inlet 1213 and an exhaust port 1214 , and each of the first discharge branches 1211 is connected to the air inlet 1213 , and each of the first discharge branches 1211 is connected to the exhaust port 1214 .

[0106] In one embodiment, the exhaust pipeline 121 forms more than one first discharge branch 1211, and the first discharge branch 1211 is provided with a control valve 123 and a bursting disc safety device 122; the exhaust pipeline 121 also includes a second discharge branch 1212, and the second discharge branch 1212 is provided with a safety valve 126, and the exhaust pressure value of the safety valve 126 is less than the bursting pressure value of the bursting disc safety device 122; the first discharge branch 1211 and the second discharge branch 1212 are connected in parallel.

[0107] See also Figure 2 , Figure 5 as well as Figure 6 , showing a first discharge branch 1211 and a second discharge branch 1212. Figure 2 The control valve 123 is shown in the open state.

[0108] The price of the bursting disc safety device 122 is expensive. After the bursting disc safety device 122 explodes, it cannot be used again. The number of uses and the number of replacements of the bursting disc safety device 122 often have a certain impact on the cost of the superconducting magnet. Therefore, the second discharge branch 1212 is provided in this embodiment, and the exhaust pressure value of the safety valve 126 on the second discharge branch 1212 is less than the explosion pressure value of the bursting disc safety device 122. When the pressure inside the superconducting magnet increases, the pressure inside the superconducting magnet can be reduced by exhausting the second discharge branch 1212 first, so as to reduce the probability of the bursting disc safety device 122 exploding and save costs.

[0109] Exemplarily, the opening pressure of the bursting disc safety device 122 is 0.03-0.1 MPa, and the opening pressure of the bursting disc safety device 122 is 0.1-0.5 MPa.

[0110] Exemplarily, the bursting disc safety device 122 is a commonly used spring-loaded pressure valve. When the pressure is low, the spring or other elastic components constrain the valve core to the valve body, and the passage is in a "closed" state. Once the pressure in the passage exceeds the restraining force of the elastic component, the valve core separates from the valve body, and the internal pressure gas escapes, that is, the passage is in an "open" state. When the pressure drops to the set pressure, the passage will be closed again.

[0111] In this embodiment, the exhaust pipe 121 forms more than one first discharge branch 1211, that is, the number of the first discharge branch 1211 can be as follows: Figure 5 and Figure 6 The diagram shows one, but it may also be two or more, and the first discharge branches 1211 are connected in parallel.

[0112] In this embodiment, the exhaust pipe 121 forms more than one second discharge branch 1212, that is, the number of the second discharge branch 1212 can be as follows: Figure 5 and Figure 6The diagram shows one, but it may also be two or more, and the second discharge branches 1212 are connected in parallel.

[0113] Exemplarily, the exhaust pipeline 121 forms an air inlet 1213 and an exhaust port 1214, the air inlet 1213 is connected to the discharge port 111 of the service tower 13 on the cooling container 11, each first discharge branch 1211 and each second discharge branch 1212 are connected to the air inlet 1213, and each first discharge branch 1211 and each second discharge branch 1212 are connected to the exhaust port 1214.

[0114] The cryogenic container 1 of the superconducting magnet provided in this embodiment includes the following two application scenarios according to different working states of the superconducting magnet:

[0115] (1) First working state (off state)

[0116] In the unexcited state such as during the transportation of the superconducting magnet, the superconducting coil 2 has no current, and the control valve 123 is in a field-free state. At this time, the valve core 1232 is not affected by the electromagnetic force, and the control valve 123 is in a closed state.

[0117] In this state, there is no electromagnetic energy storage in the superconducting magnet, and "quenching" will not occur, so there will be no sudden increase in pressure in the superconducting magnet. Under certain conditions, such as the shutdown or failure of the refrigerator 4, or the accidental damage of the vacuum interlayer of the superconducting magnet, etc., the internal pressure of the superconducting magnet gradually increases. When it reaches the opening pressure of the safety valve 126, the safety valve 126 opens, and the pressure medium in the superconducting magnet is discharged to the external environment through the second discharge branch 1212. Since the opening pressure of the safety valve 126 is less than the bursting pressure of the bursting disc safety device 122, and there is no pressure surge, the bursting disc safety device 122 will not explode. At this time, the closing of the control valve 123 will bring a certain back pressure to the bursting disc safety device 122, but since the bursting disc safety device 122 will not explode, this back pressure will not affect the safety of the superconducting magnet and the bursting disc safety device 122. See. Figure 5 , indicating that the control valve 123 is in a closed state, Figure 5 The arrow in the middle schematically illustrates the gas flow direction, and the high-pressure gas in the superconducting magnet is discharged to the external environment through the second discharge branch 1212.

[0118] (2) Second working state (open state)

[0119] After the superconducting magnet is excited on site, the superconducting coil 2 has a constant current and generates a strong magnetic field. At this time, the control valve 123 is opened under the action of electromagnetic force, and the control valve 123 does not generate back pressure on the bursting disc safety device 122 .

[0120] At this time, if the superconducting magnet quenches, the current of the superconducting coil 2 decays within a few seconds, the coil energy is rapidly released, the liquid helium is heated to make it vaporize rapidly, the pressure inside the magnet continues to rise, and when the helium pressure exceeds the opening pressure of the safety valve 126, the safety valve 126 opens, and the pressure medium is released through the second discharge branch 1212; if the magnet inductance is high and the quench occurs under high current, the helium pressure will further increase to the bursting pressure of the bursting disc safety device 122, causing the bursting disc safety device 122 to explode, and at this time, the high-pressure medium is simultaneously released to the external environment through the first discharge branch 1211. Figure 6 , indicating that the control valve 123 is in an open state, Figure 6 The arrow in the middle schematically illustrates the gas flow direction. The high-pressure gas in the superconducting magnet is discharged to the external environment through the second discharge branch 1212 and the first discharge branch 1211.

[0121] After a period of discharge, the internal pressure of the superconducting magnet continues to drop. When the helium pressure is lower than the opening pressure of the safety valve 126, the safety valve 126 is closed and the second discharge branch 1212 is cut off. Since the bursting disc safety device 122 is already in a burst state, the helium will continue to be discharged through the first discharge branch 1211. Since the magnetic field of the magnet has decayed after the quench, the control valve 123 is in a field-free environment. When the helium pressure is lower than the opening pressure of the control valve 123, the control valve 123 is closed, the first discharge branch 1211 is cut off, and the magnet stops discharging.

[0122] The superconducting magnet provided in this embodiment is described below with reference to the accompanying drawings.

[0123] See also Figure 2-Figure 3 This embodiment provides a superconducting magnet, including the low-temperature container 1 described in any of the above embodiments.

[0124] Exemplarily, the superconducting magnet further includes a superconducting coil 2, a cryogenic container assembly 3, a refrigerator 4, and a heating device 5, etc. The superconducting coil 2 is arranged in the cryogenic container 1, and a large amount of liquid helium is injected into the cryogenic container assembly 3 to soak the superconducting coil 2, so that the superconducting coil 2 maintains a superconducting state. A service tower 13 is arranged on the cryogenic container 1, and a discharge port 111 of the service tower 13 is connected to an exhaust pipeline 121, and a bursting disc safety device 122 and a control valve 123 are arranged on the exhaust pipeline 121.

[0125] The superconducting magnet uses liquid helium as a refrigerant. Under the joint action of the refrigerator 4 and the heating device 5, the pressure in the low-temperature container 1 is maintained at a slightly positive pressure state that is always slightly higher than the external atmospheric pressure. The helium will not escape from the magnet, and the external air will not "backflow" into the magnet. The magnet maintains zero volatility of liquid helium, and the pressure in the superconducting magnet is usually stable in the range of 0.001 to 0.01 MPa.

[0126] After the superconducting coil 2 is excited, a magnetic field is generated. Since the control valve 123 is a magnetic control device, the control valve 123 can be in an open state under the magnetic field environment of the superconducting coil 2, so that the control valve 123 will not have an impact on the back pressure of the bursting disc safety device 122; when the superconducting coil 2 "quenches" and causes the bursting disc safety device 122 to explode, after a period of discharge, the magnetic field of the superconducting coil 2 after the quench has decayed completely, and the control valve 123 is in a non-magnetic field environment. When the helium pressure is lower than the opening pressure of the control valve 123, the control valve 123 is closed, that is, the rear side pipeline of the bursting disc safety device 122 is closed, and the helium will not continue to be discharged through the pipeline where the bursting disc safety device 122 is located.

[0127] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A cryogenic container for a superconducting magnet, characterized in that: include: A cooling container (11) having an accommodation space capable of accommodating a superconducting coil (2) and a coolant thermally coupled to the superconducting coil (2); A discharge assembly (12) is arranged outside the cooling container (11), the discharge assembly (12) comprises an exhaust pipeline (121), the exhaust pipeline (121) is connected to the discharge port (111) of the cooling container (11), and a control valve (123) and a bursting disc safety device (122) are arranged on the exhaust pipeline (121); The control valve (123) is a magnetic control device, and the coolant in the accommodating space can escape to the outside through the discharge port (111), the bursting disc safety device (122) and the control valve (123) in sequence.

2. The cryogenic container of the superconducting magnet according to claim 1, characterized in that: The control valve (123) and the bursting disc safety device (122) are arranged in series, and the bursting disc safety device (122) is located on a side close to the cooling container (11).

3. The cryogenic container of the superconducting magnet according to claim 1, characterized in that: The control valve (123) comprises a valve body for elastically driven pressure control and a magnetic portion (1231), wherein the magnetic portion (1231) is arranged on a valve core (1232) of the valve body.

4. The cryogenic container of the superconducting magnet according to claim 3, characterized in that: The magnetic part (1231) is made of permanent magnetic material, and the magnetic part (1231) can move under the action of an external magnetic field to control the conduction state of the control valve (123).

5. The cryogenic container of the superconducting magnet according to claim 3, characterized in that: The magnetic part (1231) is an energized coil, and the discharge assembly (12) further comprises a switching power supply (124) and a magnetic field sensing device (125); the switching power supply (124), the magnetic field sensing device (125) and the magnetic part (1231) are electrically connected; the magnetic field sensing device (125) is used to connect the circuit between the switching power supply (124) and the magnetic part (1231) when a magnetic field is detected, thereby driving the control valve (123) to operate, so as to control the control valve (123) to be in a conducting state.

6. The cryogenic container of the superconducting magnet according to claim 3, characterized in that: The control valve (123) also includes a preload adjustment structure for adjusting the opening pressure of the control valve.

7. The cryogenic container of a superconducting magnet according to claim 1, characterized in that: The low-temperature container further comprises a service tower (13), wherein the service tower (13) is arranged on the cooling container (11), and the service tower (13) is connected to the accommodating space to form the discharge port (111).

8. A cryogenic container for a superconducting magnet according to any one of claims 1 to 7, characterized in that: The exhaust pipeline (121) forms more than one first discharge branch (1211), and the control valve (123) and the bursting disc safety device (122) are arranged on the first discharge branch (1211).

9. The cryogenic container of a superconducting magnet according to claim 8, characterized in that: The exhaust pipeline (121) further comprises a second discharge branch (1212), and a safety valve (126) is arranged on the second discharge branch (1212); the first discharge branch (1211) and the second discharge branch (1212) are connected in parallel.

10. A superconducting magnet, characterized in that: A cryogenic container (1) comprising the superconducting magnet according to any one of claims 1 to 9.

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