Dry and cold magnet cooling system and magnetic resonance imaging equipment

Abstract

The utility model relates to the technical field of dry and cold magnets, in particular to a dry and cold magnet cooling system and magnetic resonance imaging equipment with the same. The dry cold magnet cooling system comprises a first cold head used for cooling a shielding layer and a second cold head used for cooling a superconducting coil. The heat exchanger exchanges heat with the first cold head and the second cold head at the same time through a heat exchange pipe system; wherein the heat exchange pipe system comprises a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline and the second heat exchange pipeline are connected with the sleeve assembly and the heat exchanger respectively, the first heat exchange pipeline exchanges heat with the second cold head, and the second heat exchange pipeline exchanges heat with the first cold head; and one end of the thermal link is connected with the heat exchanger, and the other end of the thermal link is connected with a superconducting coil. The heat exchange pipe system exchanges heat with the first cold head and the second cold head at the same time, so that the cooling time of an existing dry cold magnet cooling system can be shortened, and the cooling efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of dry-cooled magnets, in particular to a dry-cooled magnet cooling system and a magnetic resonance imaging device equipped with the same. Background Art

[0002] A dry-cool magnet is a magnet that does not require immersion in liquid helium. The cooling system of a dry-cool magnet mainly relies on the circulation of helium gas to transfer the cooling capacity of the cold head to cool the superconducting coil and its supporting structure. The slow flow of helium leads to natural convection, but the convective heat transfer efficiency is low, and the maximum cooling capacity that can be transferred by gas convection is limited by the cooling power of the second-stage cold head. Therefore, the existing dry-cool magnet cooling system has a long cooling time and low cooling efficiency. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a dry cooling magnet cooling system and a magnetic resonance imaging device equipped therewith, which can solve the problems of long cooling time and low cooling efficiency of the existing dry cooling magnet cooling system.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the utility model provides a dry cooling magnet cooling system, comprising:

[0005] a first cold head for cooling the shielding layer and a second cold head for cooling the superconducting coil;

[0006] A heat exchanger, exchanging heat with the first cold head and the second cold head simultaneously through a heat exchange piping system; wherein the heat exchange piping system includes a first heat exchange piping and a second heat exchange piping, the first heat exchange piping and the second heat exchange piping are respectively connected to the sleeve assembly and the heat exchanger, the first heat exchange piping exchanges heat with the second cold head, and the second heat exchange piping exchanges heat with the first cold head;

[0007] A thermal link, one end of which is connected to the heat exchanger, and the other end of which is connected to the superconducting coil.

[0008] In one embodiment of the utility model, a convection component is further included, which is arranged in the second heat exchange pipeline of the heat exchange pipeline system, and the convection component is configured to drive the gas in the second heat exchange pipeline to circulate between the heat exchanger and the sleeve assembly.

[0009] In one embodiment of the utility model, the convection component includes a first one-way valve and a driving element. The first one-way valve is movably arranged in the second heat exchange pipeline of the heat exchange pipeline system, and the driving element is used to drive the first one-way valve to reciprocate along the length direction of the second heat exchange pipeline.

[0010] In one embodiment of the utility model, the convection component further includes a second one-way valve, which is fixedly installed in the second heat exchange pipeline, and the opening direction of the second one-way valve is the same as that of the first one-way valve.

[0011] In an embodiment of the utility model, the driving element includes a motor and a connecting rod, one end of the connecting rod is connected to the motor, and the other end of the connecting rod is connected to the first one-way valve.

[0012] In one embodiment of the utility model, the convection component includes a fan or a pressure pump.

[0013] In one embodiment of the utility model, the first cold head and the second cold head are arranged inside the sleeve assembly, the first cold head is located above the second cold head, and a cavity for gas flow is formed between the first cold head, the second cold head and the sleeve assembly.

[0014] In one embodiment of the utility model, the sleeve assembly includes a first sleeve, a second sleeve and a heat-conducting component, the first sleeve is connected to the second sleeve through the heat-conducting component, and the first sleeve is located above the second sleeve.

[0015] In one embodiment of the utility model, the first cold head is contactingly arranged above the heat-conducting component, the heat-conducting component and the first cold head divide the sleeve into two spaces, and a channel connecting the upper and lower spaces is provided between the heat-conducting component or the first cold head or both.

[0016] In one embodiment of the utility model, the first heat exchange pipeline includes a first supply pipe and a first return pipe, one end of the first supply pipe and the first return pipe are respectively connected to the inner cavity of the second sleeve, and the other end is respectively connected to the heat exchanger.

[0017] In an embodiment of the utility model, the heat-conducting component is provided with an internal flow channel, and the second heat exchange pipeline is connected to the internal flow channel.

[0018] In one embodiment of the utility model, the second heat exchange pipeline includes a second supply pipe and a second return pipe, both ends of the internal flow channel respectively pass through to the outside of the heat-conducting component, one end of the second supply pipe and the second return pipe are respectively connected to the two ends of the internal flow channel, and the other ends of the second supply pipe and the second return pipe are respectively connected to the heat exchanger.

[0019] In one embodiment of the utility model, the second heat exchange pipeline includes a first supply pipe and a second return pipe, one end of the internal flow channel passes through to the outside of the heat-conducting component, and the other end is connected to the inner cavity of the second sleeve; one end of the second return pipe is connected to the heat exchanger, and the other end is connected to the internal flow channel, one end of the first supply pipe is connected to the inner cavity of the second sleeve, and the other end is connected to the heat exchanger.

[0020] In one embodiment of the utility model, the second heat exchange pipeline is communicated with the inner cavity of the first sleeve.

[0021] In an embodiment of the present invention, the first cold head is connected to the shielding layer through a thermal connector.

[0022] In one embodiment of the utility model, the heat exchange pipe system includes an auxiliary pipe, one end of the auxiliary pipe is connected to the heat exchanger, and the other end is open upward and is provided with a safety valve.

[0023] An embodiment of the present invention further provides a magnetic resonance imaging device having any of the above-mentioned dry cooling magnet cooling systems.

[0024] The utility model exchanges heat with the first cold head for cooling the shielding layer and the second cold head for cooling the superconducting coil at the same time through the heat exchange pipe system, making full use of the residual cooling capacity of the first cold head, accelerating the cooling rate of the magnet and reducing the cooling time;

[0025] One end of the first heat exchange pipeline is connected to the second sleeve to achieve heat exchange with the second cold head, so as to utilize the cooling capacity of the second cold head, and the superconducting coil is cooled by heat exchange between the first heat exchange pipeline and the heat exchanger;

[0026] One end of the second heat exchange pipeline is connected to the heat conductive component or the first sleeve to achieve heat exchange with the first cold head, so as to utilize the cooling capacity of the first cold head, and the superconducting coil is cooled by heat exchange between the second heat exchange pipeline and the heat exchanger;

[0027] By setting auxiliary pipes and safety valves, a pressure relief channel is realized in the dry cooling magnet cooling system;

[0028] The convection components are arranged to form forced convection heat exchange in the helium circulation pipeline, thereby improving the convection heat exchange efficiency in the entire helium circulation;

[0029] Therefore, the dry-cooling magnet cooling system proposed by the utility model can solve the problems of long cooling time and low cooling efficiency of the existing dry-cooling magnet cooling system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1It is a structural schematic diagram of a dry cooling magnet cooling system in the prior art;

[0031] Figure 2 This is a schematic structural diagram of the first dry cooling magnet cooling system provided by the utility model;

[0032] Figure 3 A schematic diagram of the structure of the heat-conducting component provided by the utility model;

[0033] Figure 4 A schematic diagram of the structure of an internal flow channel provided by the utility model;

[0034] Figure 5 A schematic diagram of the structure of a second dry cooling magnet cooling system provided by the utility model;

[0035] Figure 6 A schematic structural diagram of a third dry cooling magnet cooling system provided by the utility model;

[0036] Figure 7 A schematic structural diagram of a fourth dry cooling magnet cooling system provided by the utility model;

[0037] In the figure: 1, first cold head; 2, second cold head; 3, heat exchanger; 4, superconducting coil; 5, heat link; 6, heat exchange pipe system; 61, first supply pipe; 62, first return pipe; 62, second supply pipe; 64, second return pipe; 7, sleeve assembly; 71, first sleeve; 72, second sleeve; 73, heat conductive component; 8, recessed cavity; 9, flange; 10, auxiliary pipe; 11, safety valve; 12, first one-way valve; 13, motor; 14, connecting rod; 15, second one-way valve; 16, fan. DETAILED DESCRIPTION

[0038] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0039] It should be noted that the illustrations provided in the following embodiments are only used to schematically illustrate the basic concept of the present invention, and thus the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0040] First, the technical background of this embodiment is briefly introduced. Figure 1 The figure is a schematic diagram of the structure of the dry cooling magnet cooling system in the prior art, which includes: a second cold head 2, a heat exchanger 3, a heat link 5 and a heat exchange pipe system 6, through which heat exchange can be performed with the second cold head 2, one end of the heat link 5 is connected to the heat exchanger 3, and the other end is connected to the superconducting coil 4.

[0041] Specifically, the superconducting coil 4 of the current dry-cooled magnet is not immersed in liquid helium, and the superconducting coil 4 is cooled by the second cold head 2 through the helium circulation of the sleeve assembly 7 and the heat exchanger 3 .

[0042] The helium in the second cold head 2 is cooled, and the temperature difference between it and the helium in the heater exchanger causes a density difference. The high-density cold helium flows downward into the heat exchanger 3 through the pipeline of the heat exchange pipe system 6. The cold energy of the second cold head 2 carried by the cold helium is transferred to the superconducting coil 4 through the heat link 5, and then becomes low-density hot helium. The hot helium rises to the second cold head 2 through the pipeline of the heat exchange pipe system 6, which generates a natural convection cycle of the helium.

[0043] In the current cooling scheme, the cold head in the existing dry-cooled magnet cooling system refers to the GM compression refrigerator, which provides continuous closed-cycle refrigeration at a specific temperature. For the 4K cold head, it is generally a two-stage refrigeration, which can be achieved through the first cold head 1 and the second cold head 2. The first cold head 1 is connected to the 50K shielding layer and is used to cool the shielding layer. The refrigeration temperature can reach 25K-50K. The second cold head 2 is in contact with helium and is used to cool the superconducting coil 4, which can reach 3.5K-5K; the second cold head 2 can liquefy the helium to ensure zero volatilization of liquid helium.

[0044] The first cold head is connected to the 50K shielding layer through a thermal connector, which can be a copper braid, an aluminum plate, etc. After the first cold head 1 cools the 50K shielding layer to a stable temperature, only a small cooling capacity is required to maintain thermal balance. Usually in the cooling process of the existing magnet, since the cooling capacity of the first cold head 1 is much greater than the heat load to be cooled, a large amount of residual cold will cool the first cold head itself, and the temperature of the first cold head 1 will continue to drop.

[0045] Furthermore, the cooling capacity of the first cold head 1 is much higher than that of the second cold head 2 . The cooling capacity of the cold head is related to its working temperature. A decrease in the temperature of the cold head will reduce its cooling capacity.

[0046] In order to solve the problems of long cooling time and low cooling efficiency of dry-cooled magnet cooling systems in the prior art, the utility model proposes a dry-cooled magnet cooling system, which simultaneously exchanges heat with a first cold head 1 and a second cold head 2 through a heat exchange pipe system 6, and helium can cool the superconducting coil 4 through the first cold head 1. The remaining cooling capacity of the first cold head 1 can be used to cool the superconducting coil 4 to speed up the cooling speed of the entire magnet, and more heat load is transferred to the first cold head 1, which can increase the working temperature of the first cold head 1, thereby increasing the cooling capacity of the first cold head 1, thereby further improving the heat transfer performance of the entire cycle; in addition, since the cooling capacity of the first cold head 1 is much higher than that of the second cold head 2, the cooling speed of the superconducting coil 4 will be greatly improved.

[0047] Example 1

[0048] See also Figure 2 As shown, this embodiment proposes a dry cooling magnet cooling system, including a first cold head 1, a second cold head 2, a sleeve assembly 7, a heat exchanger 3, a thermal link 5 and a heat exchange pipe system 6; through the heat exchange pipe system 6, heat exchange can be performed with the first cold head 1 and the second cold head 2 at the same time, one end of the thermal link 5 is connected to the heat exchanger 3, and the other end is connected to the superconducting coil 4.

[0049] The first cold head 1 is connected to the 50K shielding layer and is used to cool the shielding layer, and the cooling temperature can reach 25K-50K. The second cold head 2 is in contact with helium and is used to cool the superconducting coil 4, which can reach 3.5K-5K. When the helium is heat exchanged using the second cold head 2, the helium may be liquefied into liquid helium, which is collectively referred to as helium below. The state of the helium during actual operation is not limited here.

[0050] In this embodiment, the heat exchange pipe system 6 is connected to the first cold head 1 and the second cold head 2 respectively, so as to utilize the cooling capacity of the first cold head 1 and the second cold head 2, make full use of the remaining cooling capacity of the first cold head stage, and accelerate the cooling rate of the magnet; and more heat load is transferred to the first cold head 1, which can increase the working temperature of the first cold head 1, thereby increasing the cooling capacity of the first cold head 1.

[0051] The second cold head 2 may be a fin structure, or some metal porous media may be placed in the heat exchanger 3 to increase the heat transfer area of ​​the helium, thereby shortening the cooling time.

[0052] Specifically, the sleeve assembly 7 includes a first sleeve 71, a second sleeve 72 and a heat-conducting component 73, the first sleeve 71 and the second sleeve 72 are connected through the heat-conducting component 73, the first sleeve 71 is located above the second sleeve 72, and a closed space is formed inside the sleeve assembly 7; wherein the heat-conducting component 73 can be a copper block.

[0053] It should be noted that the first sleeve 71 and the second sleeve 72 are hollow structures, and the first sleeve 71 and the second sleeve 72 can be in the shape of a cylinder, a rectangular parallelepiped, etc.; the heat-conducting component 73 is a hollow structure, and the heat-conducting component 73 can be in the shape of a rectangular parallelepiped, a cylinder, etc.

[0054] In this embodiment, the first cold head 1 and the second cold head 2 are arranged in the hollow structure of the sleeve assembly 7, and a cavity for gas flow is formed between the first cold head 1 and the second cold head 2 and the sleeve assembly 7.

[0055] Specifically, the first cold head 1 is arranged in contact with the top of the heat-conducting component 73, and the first cold head 1 is located above the second cold head 2. The heat-conducting component 73 and the first cold head 1 divide the sleeve into two semi-enclosed spaces: a first space and a second space. The first space and the second space are connected by a heat-conducting component to form a closed space. The heat-conducting component 73 or the first cold head 1 or a channel connecting the upper and lower spaces is provided between the two.

[0056] See also Figure 3 As shown, the upper surface of the heat-conducting component 73 may be provided with a recessed cavity 8 connecting the upper and lower spaces. When the heat-conducting component 73 contacts the first cold head 1 , the helium in the first space flows into the second space through the recessed cavity 8 of the heat-conducting component 73 .

[0057] In an optional embodiment of the utility model, the first space is composed of a first sleeve 71, a first cold head 1 and a heat-conducting component, and the second space is composed of a second sleeve 72, a second cold head 2 and a heat-conducting component 73. The first sleeve 71 and the second sleeve 72 are semi-enclosed structures.

[0058] In another optional embodiment of the utility model, the first space is composed of a flange 9 , a first sleeve 71 , a first cold head 1 and a heat-conducting component, and the flange 9 is arranged above the first sleeve 71 .

[0059] See also Figure 2 As shown, the heat exchange piping system 6 includes a first heat exchange pipeline and a second heat exchange pipeline, the first heat exchange pipeline and the second heat exchange pipeline are respectively connected to the sleeve assembly 7 and the heat exchanger 3, the first heat exchange pipeline exchanges heat with the second cold head 2, and the second heat exchange pipeline exchanges heat with the first cold head.

[0060] The heat-conducting component 73 is provided with an internal flow channel, and the second heat exchange pipeline is connected to the internal flow channel, so as to realize cooling of the superconducting coil 4 by utilizing the cooling capacity of the first cold head.

[0061] Specifically, the first heat exchange pipeline includes a first supply pipe 61 and a first return pipe 62. One end of the first supply pipe 61 and the first return pipe 62 are respectively connected to the inner cavity of the second sleeve 72 (i.e., the second space), and the other end is respectively connected to the heat exchanger 3 to achieve cooling of the superconducting coil 4 by utilizing the cooling capacity of the second cold head 2.

[0062] In this embodiment, the second heat exchange pipeline includes a second supply pipe 63 and a second return pipe 64, and both ends of the internal flow channel are respectively connected to the outside of the heat conductive component 73, one end of the second supply pipe 63 and the second return pipe 64 are respectively connected to the two ends of the internal flow channel, and the other ends of the second supply pipe 63 and the second return pipe 64 are respectively connected to the heat exchanger 3.

[0063] See also Figure 4 As shown, the side of the heat-conducting component 73 that contacts the cavity where the helium flows is called the inner wall, and the side of the heat-conducting component 73 that does not contact the cavity where the helium flows is called the outer wall; the two ends of the internal flow channel are located on the outer wall of the heat-conducting component 73 without overlapping, and the internal flow channel is a closed space. The shape of the internal flow channel can be a cylinder, a cuboid or an irregular curved shape, and the shape of the internal flow channel is not specifically limited here.

[0064] The second heat exchange pipeline forms a separate and complete gas flow channel between the heat-conducting component 73 and the heat exchanger 3 through the second supply pipe 63 and the second return pipe 64. It is not in direct contact with the helium in the first space and the second space, but in contact with the heat-conducting component 73, thereby realizing the utilization of the cooling capacity of the second cold head 2 and cooling the helium in the second return pipe 64, thereby improving the cooling efficiency; the cooled helium is transmitted to the heat exchanger 3 through the second supply pipe 63, and the heat exchanger 3 transfers the cold to the superconducting coil 4 through the thermal link 5.

[0065] In this embodiment, the dry cooling magnet cooling system further includes an auxiliary pipe 10 and a safety valve 11 as a reserved pressure relief channel.

[0066] In an actual application scenario, when the magnet needs to be quickly restored to room temperature for inspection, after the cold head is turned off, the heat transferred from the room temperature end will be quickly transferred to the cold head, and the heat at the cold head end can be quickly transferred to the magnet, accelerating the heating process of the magnet; the cooling process after the inspection is similar to the above process.

[0067] Example 2

[0068] See also Figure 5-Figure 7As shown, in this embodiment, the second heat exchange pipeline includes a first supply pipe 61 and a second return pipe 64, one end of the internal flow channel is connected to the outer side of the heat-conducting component 73, and the other end is connected to the inner cavity of the second sleeve 72; one end of the second return pipe 64 is connected to the heat exchanger 3, and the other end is connected to the internal flow channel, one end of the first supply pipe 61 is connected to the inner cavity of the second sleeve 72, and the other end is connected to the heat exchanger 3.

[0069] Among them, the side of the heat-conducting component 73 that contacts the cavity where the helium flows is called the inner wall, and the side of the heat-conducting component 73 that does not contact the cavity where the helium flows is called the outer wall; one end of the internal flow channel is located on the outer wall of the heat-conducting component 73, and the other end is located on the inner wall of the heat-conducting component 73; the internal flow channel is connected to the inner cavity of the second sleeve 72 (i.e., the second space), first contacts the heat-conducting component 73, and uses the cooling capacity of the first cold head 1 to achieve hot helium cooling; then enters the second space, and uses the cooling capacity of the second cold head 2 to achieve hot helium cooling; finally, the cooled helium is transmitted to the heat exchanger 3 with the help of the first heat exchange pipeline, and the heat exchanger 3 transfers the cold to the superconducting coil 4 through the thermal link 5.

[0070] In this embodiment, by first performing heat exchange with the heat-conducting component 73 and the first cold head 1, and then performing heat exchange with the second cold head 2 in the second space, the design of the gas flow channel is more convenient, and the helium can completely absorb the cooling capacity of the two-stage cold heads, thereby improving the cooling effect.

[0071] Example 3

[0072] In this embodiment, the second heat exchange pipeline is connected to the inner cavity (ie, the first space) of the first sleeve 71 .

[0073] In an optional embodiment of the utility model, the second heat exchange pipeline includes a second supply pipe 63 and a second return pipe 64, one end of the second supply pipe 63 and the second return pipe 64 are respectively connected to the inner cavity of the first sleeve 71, and the other end of the second supply pipe 63 and the second return pipe 64 are respectively connected to the heat exchanger 3.

[0074] Specifically, the hot helium in the second return pipe 64 flows into the first space corresponding to the first sleeve 71, and can perform heat exchange with the hot helium through the first cold head 1, and the cooled helium is transmitted to the heat exchanger 3 through the second supply pipe 63, or the helium flows into the second space through the first space, performs heat exchange through the second cold head 2, and then the cooled helium is transmitted to the heat exchanger 3 through the first supply pipe 61, and the heat exchanger 3 transfers the cold to the superconducting coil 4 through the thermal link 5.

[0075] In another optional embodiment of the utility model, the second heat exchange pipeline includes a first supply pipe 61 and a second return pipe 64, one end of the second return pipe 64 is connected to the heat exchanger 3, and the other end is connected to the inner cavity of the first sleeve 71, one end of the first supply pipe 61 is connected to the inner cavity of the second sleeve 72, and the other end is connected to the heat exchanger 3.

[0076] Specifically, the hot helium in the second return pipe 64 flows into the first space corresponding to the first sleeve 71, and the helium flows into the second space through the first space. After heat exchange through the second cold head 2, the cooled helium is transmitted to the heat exchanger 3 through the first supply pipe 61, and the heat exchanger 3 then transfers the cold to the superconducting coil 4 through the thermal link 5.

[0077] Example 4

[0078] If the gas circulation relies solely on natural convection, the flow rate will be very slow and the convective heat transfer efficiency will not be high. Forced convection can be achieved by driving the opening and closing of the one-way valve by a motor, thereby improving the convective heat transfer efficiency of the entire gas cooling cycle; and the rapid flow of helium will also transfer more heat from the superconducting coil 4 to the cold head, so that the temperature of the cold head will not drop rapidly, thereby maintaining a high cooling capacity.

[0079] See also Figure 6 As shown, this embodiment proposes a dry cooling magnet cooling system, including a first cold head 1, a second cold head 2, a sleeve assembly 7, a heat exchanger 3, a thermal link 5, a heat exchange pipe system 6 and a convection component; through the heat exchange pipe system 6, heat exchange can be performed with the first cold head 1 and the second cold head 2 at the same time, one end of the thermal link 5 is connected to the heat exchanger 3, and the other end is connected to the superconducting coil 4, the convection component is arranged in the heat exchange pipe system 6, and the convection component is assembled to be able to drive the gas in the heat exchange pipe system 6 to circulate between the heat exchanger and the sleeve assembly 7.

[0080] Specifically, when the pipes of the heat exchange piping system 6 are relatively thin, relatively long, the convection assembly includes a first one-way valve 12 and a driving element, wherein the first one-way valve is movably arranged in the pipes of the heat exchange piping system 6, and the driving element is used to drive the first one-way valve 12 to reciprocate along the length direction of the pipe.

[0081] The driving element includes a motor 13 and a connecting rod 14 , one end of the connecting rod 14 is connected to the motor 13 , and the other end of the connecting rod 14 is connected to the first one-way valve 12 .

[0082] Specifically, the convection component can be arranged in the first heat exchange pipeline or the second heat exchange pipeline. Taking the second return pipe arranged in the second heat exchange pipeline as an example, the pipeline formed by the convection component and the second return pipe is a T-shaped pipeline. The pipeline corresponding to the convection component forms a direct current pipeline (the pipeline in the direction of movement of the one-way valve) and a right-angle pipeline (the pipeline in the direction of movement of the non-one-way valve) with the pipeline of the original second return pipe respectively. The direct current pipeline in the second return pipe can also be used as an auxiliary pipeline for pressure relief when there is no motor working.

[0083] In this embodiment, the helium in the heat exchange pipe system 6 can flow from the heat exchanger 3 to the reflux pipe, and the helium in the reflux pipe flows through the internal flow channel, the first space or the second space and then flows into the supply pipe, and then flows into the heat exchanger 3 through the supply pipe, and circulates according to the above-mentioned flow direction of the helium.

[0084] Furthermore, the first one-way valve 12 is in a relatively thin, relatively thin and relatively long pipe, and the motor 13 drives the first one-way valve 12 to reciprocate along the length direction of the pipe through the connecting rod 14 when it is working. In the initial state, the gas pressure at each location in the helium circulation pipe is equal, and the one-way valve is in a closed state. When the first one-way valve 12 moves upward, the gas pressure at the upper end of the first one-way valve 12 is greater than the gas pressure at the lower end, and the first one-way valve 12 is closed and promotes the flow of helium; when the first one-way valve 12 moves downward, the gas pressure at the lower end of the first one-way valve 12 is greater than the gas pressure at the lower end, and the first one-way valve 12 is opened due to the resistance of the helium at the lower end, and the helium flows upward through the one-way valve; and then, under the action of the up and down reciprocating motion of the first one-way valve 12, forced convection heat exchange is formed in the helium circulation pipe, thereby improving the convection heat transfer efficiency of the entire gas cooling cycle.

[0085] In an actual application scenario, after the temperature of the superconducting coil 4 is lower than that of the first cold head 1 , the temperature of the first cold head 1 cannot be further reduced, so the motor 13 needs to be turned off to prevent the first cold head 1 from increasing the heat load of the superconducting coil 4 .

[0086] Furthermore, the motor 13 can be made into a tooling and connected to the connecting rod 14 in a detachable manner. When the motor 13 is not needed to work, the outlet of the connecting rod 14 can be sealed by a pipe flange; by designing the motor 13 as a detachable module or tooling, it can be connected to the cooling system when needed and disassembled when not needed, so as to achieve flexible use and control of the motor 13; when the motor 13 is not needed, it can be removed from the system to avoid it from generating heat load on the cooling system, ensuring that the cooling effect of the first cold head 1 will not be affected by the heat load of the motor 13, which helps to improve the efficiency and performance of the cooling system.

[0087] Example 5

[0088] See also Figure 2 as well as Figure 4 As shown, when the length of the heat exchange pipe system 6 is limited, forced convection can be achieved by opening and closing two one-way valves driven by a motor.

[0089] In this embodiment, the convection component includes a first one-way valve 12, a second one-way valve 15 and a driving element. The first one-way valve 12 is movably arranged in the pipeline in the heat exchange piping system 6, and the second one-way valve 15 is fixedly installed in the pipeline. The opening direction of the second one-way valve 15 is the same as that of the first one-way valve 12. The driving element is used to drive the one-way valve to reciprocate along the length direction of the pipeline.

[0090] Specifically, see Figure 5 As shown, when the motor 13 is working, the connecting rod 14 drives the first one-way valve 12 to move away from the second one-way valve 15, and the volume between the first one-way valve 12 and the second one-way valve 15 increases, and the pressure decreases. The second one-way valve 15 will open due to the pressure difference at both ends, and the helium at one end of the second one-way valve 15 will flow up to the space between the first one-way valve 12 and the second one-way valve 15 until the pressure difference disappears and the second one-way valve 15 is closed.

[0091] When the first one-way valve 12 moves toward the direction approaching the second one-way valve 15, the volume between the first one-way valve 12 and the second one-way valve 15 decreases, the helium in the space between the first one-way valve 12 and the second one-way valve 15 is compressed, the pressure increases, the first one-way valve 12 opens, and the helium in the space flows upward until the pressure at both ends of the first one-way valve 12 is balanced, the first one-way valve 12 closes and moves away from the second one-way valve 15 again, at this time forced convection is formed in the gas circuit, thereby improving the convective heat transfer efficiency of the entire gas cooling cycle.

[0092] Example 6

[0093] In order to reduce the complexity of the forced convection device, this embodiment can use devices such as a pressure pump and a circulating fan to achieve forced gas convection.

[0094] See also Figure 7 As shown, the convection component includes a fan 16, and the fan 16 is a low-temperature circulation fan. The motor of the low-temperature circulation fan can operate in the low-temperature environment of the above-mentioned cooling system, and can provide a larger flow rate and pressure, so that the gas convection speed is faster; forced convection is achieved by the fan 16 to improve the convection heat transfer efficiency of the entire gas cooling cycle.

[0095] References throughout the specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. In addition, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the present invention.

[0096] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0097] In addition, unless otherwise explicitly indicated, any marking arrows in the drawings should be regarded as exemplary only and not limiting. In addition, unless otherwise indicated, the term "or" used herein is generally intended to mean "and / or". In the case where the term is not clear because it is anticipated that the ability to separate or combine is provided, the combination of components or steps will also be regarded as indicated.

[0098] As used in the description herein and throughout the claims that follow, "a", "an", and "the" include plural references unless otherwise indicated. Likewise, as used in the description herein and throughout the claims that follow, the meaning of "in" includes "in" and "on" unless otherwise indicated.

[0099] The above description of the illustrated embodiments of the present invention (including that described in the Abstract of the Specification) is not intended to be an exhaustive list or to limit the present invention to the precise form disclosed herein. Although specific embodiments of the present invention and examples of the present invention are described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the present invention as will be recognized and understood by those skilled in the art. As noted, these modifications may be made to the present invention in accordance with the above description of the embodiments described in the present invention, and these modifications will be within the spirit and scope of the present invention.

[0100] Systems and methods have been generally described herein as details that are helpful for understanding the present invention. In addition, various specific details have been given to provide an overall understanding of the embodiments of the present invention. However, those skilled in the relevant art will recognize that the embodiments of the present invention can be practiced without one or more specific details, or practiced using other devices, systems, accessories, methods, components, materials, parts, etc. In other cases, well-known structures, materials, and / or operations are not specifically shown or described in detail to avoid confusion with various aspects of the embodiments of the present invention.

Claims

1. A dry cooling magnet cooling system, characterized in that: include: a first cold head for cooling the shielding layer and a second cold head for cooling the superconducting coil; A heat exchanger, exchanging heat with the first cold head and the second cold head simultaneously through a heat exchange piping system; wherein the heat exchange piping system includes a first heat exchange piping and a second heat exchange piping, the first heat exchange piping and the second heat exchange piping are respectively connected to the sleeve assembly and the heat exchanger, the first heat exchange piping exchanges heat with the second cold head, and the second heat exchange piping exchanges heat with the first cold head; A thermal link, one end of which is connected to the heat exchanger, and the other end of which is connected to the superconducting coil.

2. The dry cooling magnet cooling system according to claim 1, characterized in that: It also includes a convection component, which is arranged in the second heat exchange pipeline of the heat exchange pipeline system, and the convection component is configured to drive the gas in the second heat exchange pipeline to circulate between the heat exchanger and the sleeve assembly.

3. The dry cooling magnet cooling system according to claim 2, characterized in that: The convection component includes a first one-way valve and a driving element. The first one-way valve is movably arranged in the second heat exchange pipeline of the heat exchange pipeline system. The driving element is used to drive the first one-way valve to reciprocate along the length direction of the second heat exchange pipeline.

4. The dry cooling magnet cooling system according to claim 3, characterized in that: The convection component also includes a second one-way valve, which is fixedly installed in the second heat exchange pipeline, and the opening direction of the second one-way valve is the same as that of the first one-way valve.

5. The dry cooling magnet cooling system according to claim 3, characterized in that: The driving element includes a motor and a connecting rod, one end of the connecting rod is connected to the motor, and the other end of the connecting rod is connected to the first one-way valve.

6. The dry cooling magnet cooling system according to claim 2, characterized in that: The convection component includes a fan or a pressure pump.

7. The dry cooling magnet cooling system according to claim 1, characterized in that: The first cold head and the second cold head are arranged inside the sleeve assembly, the first cold head is located above the second cold head, and a cavity for gas flow is formed between the first cold head, the second cold head and the sleeve assembly.

8. The dry cooling magnet cooling system according to claim 1, characterized in that: The sleeve assembly includes a first sleeve, a second sleeve and a heat-conducting component. The first sleeve is connected to the second sleeve through the heat-conducting component. The first sleeve is located above the second sleeve.

9. The dry cooling magnet cooling system according to claim 8, characterized in that: The first cold head is arranged above the heat-conducting component, the heat-conducting component and the first cold head divide the sleeve into two spaces, and a channel connecting the upper and lower spaces is provided between the heat-conducting component or the first cold head or both.

10. The dry cooling magnet cooling system according to claim 8, characterized in that: The first heat exchange pipeline includes a first supply pipe and a first return pipe. One end of the first supply pipe and the first return pipe are respectively communicated with the inner cavity of the second sleeve, and the other end is respectively connected to the heat exchanger.

11. The dry cooling magnet cooling system according to claim 8, characterized in that: The heat-conducting component is provided with an internal flow channel, and the second heat exchange pipeline is communicated with the internal flow channel.

12. The dry cooling magnet cooling system according to claim 11, characterized in that: It also includes a convection component, which is arranged in the second heat exchange pipeline of the heat exchange pipeline system. The convection component is equipped to drive the gas in the second heat exchange pipeline to circulate between the heat exchanger and the sleeve assembly. The second heat exchange pipeline includes a second supply pipe and a second return pipe. The two ends of the internal flow channel are respectively passed through to the outside of the heat conductive component. One end of the second supply pipe and the second return pipe are respectively connected to the two ends of the internal flow channel, and the other ends of the second supply pipe and the second return pipe are respectively connected to the heat exchanger. The convection component is arranged in the second return pipe.

13. The dry cooling magnet cooling system according to claim 11, characterized in that: It also includes a convection component, which is arranged in the second heat exchange pipeline of the heat exchange pipeline system. The convection component is equipped to drive the gas in the second heat exchange pipeline to circulate between the heat exchanger and the sleeve assembly. The second heat exchange pipeline includes a first supply pipe and a second return pipe. One end of the internal flow channel passes through the outside of the heat-conducting component, and the other end is connected to the inner cavity of the second sleeve; one end of the second return pipe is connected to the heat exchanger, and the other end is connected to the internal flow channel. One end of the first supply pipe is connected to the inner cavity of the second sleeve, and the other end is connected to the heat exchanger. The convection component is arranged in the second return pipe.

14. The dry cooling magnet cooling system according to claim 8, characterized in that: The second heat exchange pipeline is in communication with the inner cavity of the first sleeve.

15. The dry cooling magnet cooling system according to claim 1, characterized in that: The heat exchange pipe system comprises an auxiliary pipe, one end of which is connected to the heat exchanger, and the other end of which is open upward and provided with a safety valve.

16. A magnetic resonance imaging device, characterized in that: The dry cooling magnet cooling system comprises the dry cooling magnet cooling system according to any one of claims 1 to 15.

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