Refrigerating system and maintenance method thereof

Abstract

The embodiment of the invention relates to a refrigerating system and a maintenance method thereof. The refrigerating system comprises a refrigerating machine with a cold head, a cold head container and a refrigerating cavity defined by a shell. A first flange is arranged in the circumferential direction of the cold head, a second flange is arranged at the opening part of the cold head container, the cold head is arranged in the cold head container from the opening part of the cold head container, the first flange and the second flange are detachably and hermetically connected, and the cold head is sealed in the cold head container; an opening communicated with the refrigeration cavity is formed in the shell, the cold head container is arranged on the opening of the shell through a second flange, so that the cold head container extends into the refrigeration cavity, and the outer wall of the second flange and the opening of the shell are sealed, so that the internal space of the cold head container is sealed and isolated from the refrigeration cavity; when the cold head is installed in the cold head container, the end face of the cold head is connected with the cold head container so as to conduct cold to a cooling target object in the refrigeration cavity.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration and heating systems, and in particular to a refrigeration system and a maintenance method thereof. Background Art

[0002] At present, magnetron CZ single crystal superconducting magnets are widely used in solar cells, integrated circuits, semiconductors and other industries, and are one of the key production equipment. For superconducting magnets, there are three main cooling methods. The first is full immersion in liquid helium; the second is immersion in a small amount of liquid helium; the third is conduction cooling. No matter which cooling method is used, a refrigerator is required for cooling. As a key component of superconducting magnets, refrigerators need to regularly maintain pistons, and the piston maintenance cycle is about 10,000 hours. For the first two types of superconducting magnets cooled by liquid helium immersion, the refrigerator can be maintained by plugging and unplugging, and the maintenance time is short. However, the first two cooling methods require the use of liquid helium. First, liquid helium is a non-renewable resource and is expensive. Secondly, the operation of superconducting magnets using liquid helium is cumbersome, and once quenched, there will be certain safety hazards. Therefore, superconducting magnets that do not require the use of liquid helium and use conduction cooling are becoming more and more popular. However, for conduction-cooled superconducting magnets, the control of refrigerator maintenance hours is particularly critical. At present, conduction-cooled superconducting magnets mainly connect the refrigerator directly to the superconducting magnet cavity for cold transfer. In this way, when maintaining the refrigerator piston, it is impossible to perform maintenance by plugging and unplugging, because forced plugging and unplugging at low temperatures will cause ice inside the magnet, causing irreversible damage to the magnet. The entire magnet needs to be restored to room temperature and the vacuum environment inside the magnet needs to be destroyed. After maintenance at room temperature, the vacuum environment needs to be re-established and then cooled. The entire maintenance process takes a long time, about 30 days, which seriously affects production efficiency.

[0003] Therefore, how to simplify the maintenance of the refrigeration system and save maintenance time is an urgent problem to be solved. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a heat exchange system based on eddy current technology to solve at least one problem existing in the background technology.

[0005] In a first aspect, an embodiment of the present application provides a refrigeration system, the refrigeration system comprising: a refrigerator having a cold head, a cold head container, and a refrigeration chamber surrounded by a shell;

[0006] A first flange is arranged around the cold head, a second flange is arranged at the opening of the cold head container, the cold head is loaded into the cold head container from the opening of the cold head container, the first flange and the second flange are detachably sealed and connected, and the cold head is sealed in the cold head container;

[0007] The shell is provided with an opening connected to the refrigeration chamber, the cold head container is seated in the opening of the shell through the second flange, so that the cold head container extends into the refrigeration chamber, and the outer wall of the second flange and the opening of the shell form a seal, so that the internal space of the cold head container is sealed and isolated from the refrigeration chamber;

[0008] When the cold head is installed in the cold head container, the end surface of the cold head is connected to the cold head container to conduct cold to the cooling target in the refrigeration chamber.

[0009] In combination with the embodiments of the first aspect, in some embodiments, the refrigerator comprises: a refrigerator drive unit, a piston, and a refrigeration cylinder as the cold head, wherein the piston is driven by the refrigerator drive unit to move axially in the refrigeration cylinder to cool; the cold head end surface comprises the bottom end surface of the refrigeration cylinder;

[0010] The first flange is arranged at the open end of the refrigeration cylinder, and the first flange is sealedly connected to the refrigerator drive unit to seal the piston in the refrigeration cylinder;

[0011] The cold head container includes a cold conduction block;

[0012] The cooling block at least includes a cooling surface for conducting cooling from the bottom end of the refrigeration cylinder to the cooling target object.

[0013] In combination with the embodiments of the first aspect, in some embodiments, the refrigeration cylinder includes a primary cylindrical cylinder and a secondary cylindrical cylinder that are interconnected, the first flange is disposed at a first end of the primary cylindrical cylinder, the second end of the primary cylindrical cylinder is connected to the first end of the secondary cylindrical cylinder, and a radial cross-sectional area of ​​the secondary cylindrical cylinder is smaller than a radial cross-sectional area of ​​the primary cylindrical cylinder;

[0014] The bottom end surface of the refrigeration cylinder includes a first end surface outside the connection portion between the second end surface of the first-stage cylindrical cylinder and the second-stage cylindrical cylinder, and a second end surface of the second end of the second-stage cylindrical cylinder;

[0015] The cold head container comprises a first cylindrical container and a second cylindrical container, which are respectively adapted to the first cylindrical cylinder and the second cylindrical cylinder; the second flange is arranged at the first end of the first cylindrical container;

[0016] The cooling block comprises: a first cooling block between the second end of the first cylindrical container and the first end of the second cylindrical container; and a second cooling block disposed at the second end of the second cylindrical container;

[0017] The first cooling block at least comprises a first cooling surface for conducting cooling from the first end surface.

[0018] The second cooling block at least includes a second cooling surface for conducting cooling from the second end surface.

[0019] In combination with the embodiments of the first aspect, in some embodiments, the first cooling block is sealedly connected to the second end of the first cylindrical container, the first cooling block is sealedly connected to the first end of the second cylindrical container, and the second cooling block is sealedly connected to the second end of the second cylindrical container, so that the cold head container is airtight.

[0020] In combination with the embodiment of the first aspect, in some embodiments, a first indium layer is provided between the first end surface and the first cold conducting surface.

[0021] and / or

[0022] A second indium layer is disposed between the second end surface and the second cold conducting surface.

[0023] In combination with the embodiments of the first aspect, in some embodiments, the first indium layer is composed of indium sheets, and / or the second indium layer is composed of indium wires.

[0024] In combination with the embodiments of the first aspect, in some embodiments, the first cooling block is connected to conduct cooling to the first cooling target object through a first flexible cooling belt;

[0025] The second cooling block is connected to conduct cooling to the second cooling target object through a second flexible cooling belt.

[0026] In combination with the embodiment of the first aspect, in some embodiments, the first flange has an annular boss extending along the axis direction of the cold head;

[0027] The second flange has an annular groove matched with the boss;

[0028] The end surface of the boss and the bottom surface of the groove cooperate to form the sealing surface of the sealed connection, and / or the outer side surface of the boss and the inner side surface of the groove cooperate to form the sealing surface.

[0029] In combination with the embodiments of the first aspect, in some embodiments, a sealing ring is provided between the outer side surface of the boss and the inner side surface of the groove.

[0030] In combination with the embodiments of the first aspect, in some embodiments, the first flange has a first annular disk extending radially along the cold head;

[0031] The second flange has a second annular disk extending radially along the cold head;

[0032] The first annular disk and the second annular disk are connected by bolts, so that the first flange is sealed and connected to the second flange.

[0033] In a second aspect, an embodiment of the present application provides a refrigeration system maintenance method, which is applied to the refrigeration system according to any one of claims 1 to 7, and the method comprises:

[0034] The sealing connection between the first flange and the second flange is opened, and the refrigerator is moved a predetermined distance in the opposite direction of the cold head installation to the cold head container, so that the cold head end surface is disconnected from the cold head container and the cold head is at least partially located in the cold head container.

[0035] In combination with the embodiments of the second aspect, in some embodiments, the refrigerator includes: a refrigerator drive unit, a piston and a refrigeration cylinder as the cold head, wherein the piston is driven by the refrigerator drive unit to move axially in the refrigeration cylinder to cool; the cold head end surface includes the bottom end surface of the refrigeration cylinder; the first flange is arranged at the open end of the cylinder, and the first flange is sealed and connected to the refrigerator drive unit to seal the piston in the refrigeration cylinder; the cold head container includes a cooling block; the cooling block at least includes a cooling surface for conducting cooling from the bottom end surface of the refrigeration cylinder to the cooling target;

[0036] The method further comprises:

[0037] Separating the refrigerator drive unit and the first flange, and moving the assembly consisting of the refrigerator drive unit and the piston in the reverse installation direction of the piston to move the piston out of the refrigeration cylinder;

[0038] The piston is maintained.

[0039] In conjunction with the embodiment of the second aspect, in some embodiments, the method further includes:

[0040] Filling the refrigeration cylinder with gas at a first predetermined temperature to raise the temperature in the refrigeration cylinder to a second predetermined temperature;

[0041] Assembling the assembly for completing piston maintenance with the refrigeration cylinder along the installation direction of the piston, so that the piston moves into the refrigeration cylinder;

[0042] Sealingly connecting the refrigerator drive unit and the first flange;

[0043] The refrigerator is pushed, and the end surface of the cold head is connected to the cold head container;

[0044] The first flange and the second flange are sealed and connected.

[0045] A refrigeration system and maintenance method thereof provided in an embodiment of the present application, the refrigeration system comprises: a refrigerator having a cold head, a cold head container and a refrigeration chamber surrounded by a shell; a first flange is arranged around the cold head, a second flange is arranged at the opening of the cold head container, the cold head is loaded into the cold head container from the opening of the cold head container, the first flange and the second flange are detachably sealed and connected, and the cold head is sealed in the cold head container; an opening connected to the refrigeration chamber is arranged on the shell, the cold head container is seated at the opening of the shell through the second flange, so that the cold head container extends into the refrigeration chamber, the outer wall of the second flange and the opening of the shell form a seal, so that the internal space of the cold head container is sealed and isolated from the refrigeration chamber; when the cold head is installed in the cold head container, the end face of the cold head is connected to the cold head container to conduct cold to the cooling target in the refrigeration chamber. When the cold head container is seated in the refrigeration chamber, the cold head container seals and isolates the inside of the refrigeration chamber from the external environment, and the vacuum state of the refrigeration chamber can be always maintained when the cold head is maintained. The cold head container isolates the cold head from the refrigeration chamber. When the cold head needs maintenance, the cold conduction connection between the cold head and the cold head container can be disconnected at a low temperature. The cold head container isolates the external environment from the refrigeration chamber, reducing the impact of the external environment on the target cooling object during cold head maintenance and improving maintenance efficiency.

[0046] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0048] Figure 1 A schematic diagram of the composition structure of a refrigeration system provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of another refrigeration system structure provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of the composition structure of another refrigeration system provided in an embodiment of the present application;

[0051] Figure 4 A schematic diagram of a refrigeration system maintenance method provided in an embodiment of the present application;

[0052] Figure 5 A schematic diagram of the composition structure of another refrigeration system provided in an embodiment of the present application;

[0053] Figure 6 A schematic diagram of the composition structure of another refrigeration system provided in an embodiment of the present application;

[0054] Figure 7 A schematic diagram of the composition structure of another refrigeration system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0055] The exemplary embodiments disclosed in the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the specific embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope disclosed in the present application to those skilled in the art.

[0056] In the following description, a large number of specific details are given to provide a more thorough understanding of the present application. However, it is obvious to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features known in the art are not described; that is, all features of the actual embodiments are not described here, and well-known functions and structures are not described in detail.

[0057] In the drawings, the sizes of layers, regions, elements and their relative sizes may be exaggerated for clarity. Like reference numerals denote like elements throughout.

[0058] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there is no intervening element or layer. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as the second element, component, region, layer or part. And when the second element, component, region, layer or part is discussed, it does not indicate that the present application necessarily has the first element, component, region, layer or part.

[0059] Spatially relative terms such as "under", "beneath", "below", "under", "above", "above", etc., may be used here for convenience of description to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, the spatial relationship terms are intended to also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is turned over, then the elements or features described as "under other elements" or "under it" or "under it" will be oriented as "on" other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0060] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0061] In order to thoroughly understand the present application, detailed steps and detailed structures will be presented in the following description to illustrate the technical solution of the present application. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0062] A refrigeration system provided by an embodiment of the present application is described in detail below with reference to the accompanying drawings.

[0063] Specifically, Figure 1 As shown, a refrigeration system 1 provided in an embodiment of the present application comprises: a refrigerator 10 having a cold head 11, a cold head container 20 and a refrigeration chamber (not shown) surrounded by a shell;

[0064] The first flange 30 is disposed around the cold head 11, and the opening of the cold head container 20 is disposed with a second flange 40. The cold head 11 is loaded into the cold head container 20 from the opening of the cold head container 20. The first flange 30 and the second flange 40 are detachably sealed and connected to seal the cold head 11 inside the cold head container 20.

[0065] The shell is provided with an opening connected to the refrigeration chamber, and the cold head container 20 is seated in the opening of the shell through the second flange 40, so that the cold head container 20 extends into the refrigeration chamber, and the outer wall of the second flange 40 forms a seal with the opening of the shell, so that the internal space of the cold head container 20 is sealed and isolated from the refrigeration chamber;

[0066] When the cold head 11 is installed in the cold head container 20 , the end surface of the cold head 11 is connected to the cold head container 20 to conduct cold to the cooling target 50 in the refrigeration chamber.

[0067] In a possible implementation, the refrigerator 10 may be a device that implements refrigeration based on the principle of high-pressure gas expansion. For example, the refrigerator 10 may be a GM refrigerator.

[0068] The cold head 11 is used to receive the cold energy from the cold end heat exchanger and transfer the cold energy to the cooling target 50 .

[0069] For example, the cold head 11 may be a refrigeration cylinder of a GM refrigerator.

[0070] The refrigeration chamber may be used to place the cooling target 50 to isolate the cooling target 50 from the external environment, thereby reducing heat exchange between the cooling target 50 and the external environment.

[0071] For example, cooling target 50 may include a superconducting magnet.

[0072] In a possible implementation, the cold head container 20 may be a cylindrical container with one end open and the other end closed. The cold head 11 may enter the cold head container 20 from the opening. The end surface of the cold head 11 may be connected to the bottom of the cold head container 20 to achieve cooling.

[0073] It can be understood that the connection between the components in this embodiment may include direct contact, or may include an intermediate layer provided between the components.

[0074] In a possible implementation, the connection between the end surface of the cold head 11 and the bottom of the cold head container 20 may include one of the following: the end surface of the cold head 11 is in direct contact with the bottom of the cold head container 20; a heat transfer body is provided between the end surface of the cold head 11 and the bottom of the cold head container 20. The heat transfer body may fit the end surface of the cold head 11 and the cold head container 20 to enhance the heat conduction performance between the end surface of the cold head 11 and the bottom of the cold head container 20. For example, the heat transfer body may be made of indium.

[0075] In a possible implementation, there is a predetermined gap between the cold head side wall and the cold head container 20. The predetermined gap between the cold head side wall and the cold head container 20 can facilitate the cold head 11 to be inserted into the cold head container 20.

[0076] In a possible implementation, there is no gap between the cold head side wall and the cold head container 20. The cold head side wall and the inner wall of the cold head container 20 may be in contact with each other to conduct cold from the cold head 11 to the cold head container 20.

[0077] Here, the shell of the refrigeration chamber may be provided with an opening, and the opening of the cold head container 20 is provided with a second flange 40, through which the cold head container 20 is seated on the shell of the refrigeration chamber, so that the body of the cold head container 20 extends into the refrigeration chamber.

[0078] In a possible implementation, the cold head container 20 may be made of non-magnetic austenitic stainless steel, and the second flange 40 may be made of non-magnetic austenitic stainless steel.

[0079] In a possible implementation, the outer wall of the cold head container 20 is sealed to the inner wall of the second flange 40. For example, the outer wall of the cold head container 20 and the inner wall of the second flange 40 are welded together by sealed argon arc welding.

[0080] In a possible implementation, a third flange 80 is disposed around the opening of the shell of the refrigeration chamber. One side of the second flange 40 is connected to the first flange 30 , and the other side of the second flange 40 is connected to the third flange 80 .

[0081] In a possible implementation, the second flange 40 has a second annular disk extending radially along the cold head 11. The third flange 80 has a third annular disk extending radially along the cold head 11. The second annular disk and the third annular disk are sealed and connected.

[0082] In a possible implementation manner, a sealing ring is disposed between the second annular disk and the third annular disk.

[0083] In a possible implementation, the opening on the shell of the refrigeration chamber is circumferentially sealed to the third flange 80 .

[0084] In practical applications, the refrigerator 10 conducts cold energy to the cold head container 20 through the cold head 11. The cold head container 20 conducts cold energy to the target coolant by conduction. The refrigeration chamber can reduce the heat exchange between the target coolant in the refrigeration chamber and the external environment by vacuuming, thereby improving the refrigeration effect.

[0085] When the cold head container 20 is placed in the refrigeration chamber, the cold head container 20 seals and isolates the inside of the refrigeration chamber from the external environment, and can always maintain the vacuum state of the refrigeration chamber when the cold head 11 is maintained. The cold head container 20 isolates the cold head 11 from the refrigeration chamber. When the cold head 11 needs maintenance, the cold head 11 and the cold head container 20 can be disconnected from the cold conduction connection at a low temperature. The cold head container 20 isolates the external environment from the refrigeration chamber, reducing the impact of the external environment on the target cooling object when the cold head 11 is maintained, and improving the maintenance efficiency.

[0086] In some embodiments, the refrigerator 10 includes: a refrigerator drive unit 12, a piston 13 and a refrigeration cylinder (the reference numeral 11 in the figure is the refrigeration cylinder) as the cold head 11, wherein the piston 13 is driven by the refrigerator drive unit 12 to move axially in the refrigeration cylinder for refrigeration; the end surface of the cold head 11 includes the bottom end surface of the refrigeration cylinder;

[0087] The first flange 30 is disposed at the open end of the refrigeration cylinder, and the first flange 30 is sealedly connected to the refrigerator drive unit 12 to seal the piston 13 in the refrigeration cylinder;

[0088] The cold head container 20 includes a cold conduction block 21;

[0089] The cooling block 21 at least includes a cooling surface for conducting cooling from the bottom end of the refrigeration cylinder to the cooling target 50 .

[0090] The refrigerator driving unit 12 is at least used to drive the piston 13 to move in the refrigeration cylinder to provide refrigeration. The refrigerator driving unit 12 is connected to the piston 13 .

[0091] The open end of the refrigeration cylinder is provided with a first flange 30. On one hand, the first flange 30 is sealedly connected to the second flange 40; on the other hand, the first flange 30 is sealedly connected to the refrigerator drive unit 12 to seal the piston 13 in the refrigeration cylinder.

[0092] In a possible implementation, the first flange 30 and the refrigeration cylinder are an integral structure.

[0093] In a possible implementation, after the first flange 30 is disconnected from the second flange 40 , the refrigerator 10 and the first flange 30 can be moved as a whole.

[0094] In a possible implementation, the first flange 30 is detachably sealed and connected to the refrigerator drive unit 12. After the first flange 30 is disconnected from the refrigerator drive unit 12, the refrigerator drive unit 12 and the piston 13 can move as a whole, so that the piston 13 can be removed from the refrigeration cylinder.

[0095] The cooling block 21 can be made of a metal material with good heat conduction performance such as copper. The cooling block 21 can be connected to the cylinder of the cold head container 20 by sealing brazing or the like.

[0096] In a possible implementation, the cold head container 20 can be made of a metal cylinder with two ends open and a cold conduction block 21, and the cold conduction block 21 is welded to one end of the metal cylinder by sealing brazing as the bottom of the cold head container 20. After the cold head 11 is installed in the cold head container 20, the bottom end surface of the cold head 11 contacts the bottom surface of the cold head container 20 formed by the cold conduction block 21 at the bottom for cooling.

[0097] In a possible implementation, the cooling block 21 may transfer cold energy to the cooling target 50 by conduction.

[0098] During maintenance of the cold head 11, the cold head 11 can be moved in the opposite direction of installation so that the end face of the cold head 11 is disconnected from the cold conduction block 21 at the bottom. The cold head container 20 isolates the external environment and the refrigeration chamber, thereby reducing the impact of the external environment on the target cooling object during maintenance of the cold head 11 and improving maintenance efficiency.

[0099] In some embodiments, Figure 2 and Figure 3 As shown, the refrigeration cylinder includes a first-stage cylindrical cylinder 111 and a second-stage cylindrical cylinder 112 which are connected to each other, the first flange 30 is arranged at the first end of the first-stage cylindrical cylinder 111, the second end of the first-stage cylindrical cylinder 111 is connected to the first end of the second-stage cylindrical cylinder 112, and the radial cross-sectional area of ​​the second-stage cylindrical cylinder 112 is smaller than the radial cross-sectional area of ​​the first-stage cylindrical cylinder 111;

[0100] The bottom end surface of the refrigeration cylinder includes a first end surface 1111 outside the connection portion between the second end surface of the first cylindrical cylinder 111 and the second cylindrical cylinder 112, and a second end surface 1121 of the second end of the second cylindrical cylinder 112;

[0101] The cold head container 20 includes a first cylindrical container 201 and a second cylindrical container 202, which are respectively adapted to the first cylindrical cylinder 111 and the second cylindrical cylinder 112; the second flange 40 is disposed at the first end of the first cylindrical container 201;

[0102] The cooling block 21 includes: a first cooling block 211 between the second end of the first cylindrical container 201 and the first end of the second cylindrical container 202; and a second cooling block 212 disposed at the second end of the second cylindrical container 202;

[0103] The first cooling block 211 at least includes a first cooling surface 2111 for conducting cooling from the first end surface 1111.

[0104] The second cooling block 212 at least includes a second cooling surface 2121 for conducting cooling from the second end surface 1121 .

[0105] Here, the refrigerator 10 may adopt a two-stage cylinder design to improve the refrigeration efficiency. The two-stage cylinder can enable the refrigerator 10 to reach a lower temperature and provide a larger cooling capacity.

[0106] In one possible implementation, the two-stage cylinder can provide different refrigeration temperatures.

[0107] In a possible implementation, the refrigeration temperature provided by the first-stage cylindrical cylinder 111 is higher than the refrigeration temperature provided by the second-stage cylindrical cylinder 112 .

[0108] In a possible implementation, the first cylindrical container 201 and the second cylindrical container 202 may be made of non-magnetic austenitic stainless steel with a wall thickness of 0.3-1.0 mm.

[0109] In one possible implementation, the cooling target 50 includes: a first cooling target and a second cooling target; the first cooling block 211 is connected to the first flexible cooling belt 91 to conduct cooling to the first cooling target; the second cooling block 212 is connected to the second flexible cooling belt 92 to conduct cooling to the second cooling target.

[0110] Here, the first cooling target may include a cryogenic refrigeration chamber, and the second cooling target may include a superconducting magnet disposed in the cryogenic refrigeration chamber. The shell of the refrigeration chamber and the shell of the cryogenic refrigeration chamber form two-level isolation between the superconducting magnet and the external environment, thereby reducing heat exchange between the superconducting magnet and the external environment.

[0111] In a possible implementation, the first cooling block 211 conducts cooling to the shell of the cryogenic refrigeration chamber through the first flexible cooling belt 91, and the second cooling block 212 conducts cooling to the superconducting magnet through the second flexible cooling belt 92. The temperature of the environment around the superconducting magnet can be lowered by conducting cooling to the shell of the cryogenic refrigeration chamber, and the superconducting magnet can be operated at a suitable superconducting temperature by conducting cooling to the superconducting magnet.

[0112] Exemplarily, the first cooling block 211 can provide a temperature of 50K (Kelvin temperature), and the first cooling block 211 can provide a temperature of 4K (Kelvin temperature).

[0113] In some embodiments, the first cooling block 211 is sealedly connected to the second end of the first cylindrical container 201, the first cooling block 211 is sealedly connected to the first end of the second cylindrical container 202, and the second cooling block 212 is sealedly connected to the second end of the second cylindrical container 202, so that the cold head container 20 is airtight.

[0114] like Figure 2 and Figure 3As shown, the first cooling block 211 can be connected to the first cylindrical container 201 and the second cylindrical container 202 by sealing brazing. The first cooling block 211 can be connected to the cylinder of the second cylindrical container 202 by sealing brazing, and serves as the bottom of the second cylindrical container 202.

[0115] The through primary cylindrical cylinder 111 and the secondary cylindrical cylinder 112 are respectively adapted to the first cylindrical container 201 and the second cylindrical container 202. The piston 13 includes a primary piston 131 and a secondary piston 132 respectively adapted to the primary cylindrical cylinder 111 and the secondary cylindrical cylinder 112. The primary piston 131 and the secondary piston 132 are connected.

[0116] Since the radial cross-sectional area of ​​the secondary cylindrical cylinder 112 is smaller than the radial cross-sectional area of ​​the primary cylindrical cylinder 111, the first end surface 1111 of the bottom of the primary cylindrical cylinder 111, except for the connection portion with the secondary cylindrical cylinder 112, conducts cold energy in combination with the first cold conduction surface 2111 of the first cold conduction block 211. The second end surface 1121 of the bottom of the secondary cylindrical cylinder 112 conducts cold energy in combination with the second cold conduction surface 2121 of the second cold conduction block 212.

[0117] During maintenance of the cold head 11, the cold head 11 can be moved in the opposite direction of the installation direction, so that the first end face 1111 and the first cold conducting surface 2111 are separated, and the second end face 1121 and the second cold conducting surface 2121 are separated, and the cold head container 20 isolates the external environment and the refrigeration chamber, thereby reducing the impact of the external environment on the target cooling object during maintenance of the cold head 11 and improving maintenance efficiency.

[0118] In some embodiments, a first indium layer 60 is disposed between the first end surface 1111 and the first cold conducting surface 2111, and / or

[0119] A second indium layer 70 is disposed between the second end surface 1121 and the second cold conducting surface 2121 .

[0120] Since indium has good thermal conductivity and ductility, a first indium layer 60 may be provided between the first end face 1111 and the first cold conducting surface 2111, and a second indium layer 70 may be provided between the second end face 1121 and the second cold conducting surface 2121. The indium layer may fill the gap between the first end face 1111 and the first cold conducting surface 2111, or between the second end face 1121 and the second cold conducting surface to improve the conduction effect.

[0121] In some embodiments, the first indium layer 60 is formed of an indium sheet, and / or the second indium layer 70 is formed of an indium wire.

[0122] The weight of the refrigerator 10 borne by the first end surface 1111 and the first cold conducting surface 2111 is greater than the weight of the refrigerator 10 borne by the second end surface 1121 and the second cold conducting surface 2121. Therefore, the first end surface 1111 and the first cold conducting surface 2111 can be made of indium sheets, so that the gap between the first end surface 1111 and the first cold conducting surface 2111 can be better filled.

[0123] After being compressed, the indium filament between the second end surface 1121 and the second cold conducting surface 2121 can flow easily and fill the gap between the second end surface 1121 and the second cold conducting surface 2121 , thereby improving the conduction performance between the second end surface 1121 and the second cold conducting surface 2121 .

[0124] In some embodiments, the first flange 30 has an annular boss extending along the axial direction of the cold head 11;

[0125] The second flange 40 has an annular groove that cooperates with the boss;

[0126] The end surface of the boss and the bottom surface of the groove cooperate to form the sealing surface of the sealed connection, and / or the outer side surface of the boss and the inner side surface of the groove cooperate to form the sealing surface.

[0127] In order to improve the sealing performance of the first flange 30 and the second flange 40, the contact surface between the first flange 30 and the second flange 40 may be increased. Figure 1 and Figure 3 As shown, the annular boss is matched with the annular groove, the end surface of the boss and the bottom surface of the groove cooperate to form a sealing surface and / or the outer side surface of the boss and the inner side surface of the groove cooperate to form a sealing surface.

[0128] In some embodiments, a sealing ring is provided between the outer side surface of the boss and the inner side surface of the groove.

[0129] In this embodiment, the sealing ring can be made of elastic material, such as rubber, silicone and the like.

[0130] In some embodiments, the first flange 30 has a first annular disk extending radially along the cold head 11;

[0131] The second flange 40 has a second annular disk extending radially along the cold head 11;

[0132] The first annular disk and the second annular disk are connected by bolts, so that the first flange 30 and the second flange 40 are sealed and connected.

[0133] Here, the first annular disk is provided with a through hole, and the second annular disk is provided with a screw hole. The bolt penetrates the through hole and is locked in cooperation with the screw hole.

[0134] like Figure 4As shown, this embodiment provides a maintenance method for a refrigeration system 1, which is applied to any of the refrigeration systems 1 described above, and the method includes:

[0135] Step 401: Open the sealed connection between the first flange 30 and the second flange 40, move the refrigerator 10 a predetermined distance in the opposite direction of the cold head 11 installed in the cold head container 20, so that the end face of the cold head 11 is disconnected from the cold head container 20, and the cold head 11 is at least partially located in the cold head container 20.

[0136] The specific structural composition of the refrigeration system 1 is as shown in any of the above embodiments, and will not be repeated here.

[0137] This embodiment uses Figure 2 and Figure 3 The maintenance method of the refrigeration system 1 is described by taking the two-stage cylinder refrigerator shown in the figure as an example.

[0138] Figure 5 FIG. 1 is a schematic diagram showing a state where the cold head 11 is installed in the cold head container 20. Figure 6 As shown, when performing maintenance on the refrigeration system 1 (such as maintaining the cold head 11), the connecting screws between the first flange 30 and the second flange 40 can be loosened, and the refrigerator 10 can be lifted as a whole by a predetermined distance (such as 3-5 mm) to separate the first end face 1111 of the first-stage refrigeration cylinder from the first cold conduction surface 2111, and to separate the second end face 1121 of the second-stage refrigeration cylinder from the second cold conduction surface 2121, so as to separate the cold head 11 from the cold mass.

[0139] Due to the presence of the cold head container 20, the refrigeration chamber is isolated from the external environment, thereby reducing heat conduction, reducing the icing caused by the contact between the superconducting magnet and the external environment, and reducing damage to the superconducting magnet.

[0140] When the cold head container 20 is placed in the refrigeration chamber, the cold head container 20 seals and isolates the inside of the refrigeration chamber from the external environment, and the vacuum state of the refrigeration chamber can be maintained at all times when the cold head 11 is maintained. The cold head container 20 isolates the cold head 11 from the refrigeration chamber. When the cold head 11 is maintained, the cold head 11 and the cold head container 20 can be disconnected from the cold conduction connection at a low temperature. The cold head container 20 isolates the external environment from the refrigeration chamber, reducing the impact of the external environment on the target cooling object when the cold head 11 is maintained, and improving the maintenance efficiency.

[0141] In some embodiments, the refrigerator 10 includes: a refrigerator drive unit 12, a piston 13 and a refrigeration cylinder as the cold head 11, wherein the piston 13 is driven by the refrigerator drive unit 12 to move axially in the refrigeration cylinder for refrigeration; the end surface of the cold head 11 includes the end surface of the bottom end of the refrigeration cylinder; the first flange 30 is arranged at the open end of the cylinder, and the first flange 30 is sealed and connected with the refrigerator drive unit 12 to seal the piston 13 in the refrigeration cylinder; the cold head container 20 includes a cooling block 21; the cooling block 21 at least includes a cooling surface for conducting cooling from the end surface of the bottom end of the refrigeration cylinder to the cooling target 50;

[0142] The method further comprises:

[0143] Separate the refrigerator drive unit 12 and the first flange 30, and move the assembly consisting of the refrigerator drive unit 12 and the piston 13 in the reverse installation direction of the piston 13 to move the piston 13 out of the refrigeration cylinder;

[0144] The piston 13 is maintained.

[0145] like Figure 7 As shown, after the refrigerator 10 is lifted, the refrigerator drive unit 12 and the first flange 30 can be separated. Since the refrigerator drive unit 12 is connected to the piston 13, the assembly consisting of the refrigerator drive unit 12 and the piston 13 can be removed from the refrigeration cylinder.

[0146] Here, the piston 13 in the refrigeration cylinder is moved out, and the refrigeration cylinder is in direct contact with the external environment. Since the refrigeration cylinder is lifted by a predetermined distance, the air between the refrigeration cylinder and the cold head container 20 forms an insulating layer, thereby reducing the heat exchange between the cold head container 20 and the external environment, thereby reducing the loss of cold energy in the refrigeration chamber.

[0147] The screw fasteners on the main structure of the refrigerator 10 can be loosened to loosen the piston 13 of the refrigerator 10 and the cylinder of the refrigerator 10, and the piston 13 of the refrigerator 10 can be taken out.

[0148] In a possible implementation, maintaining the piston 13 includes one of the following: repairing the piston 13; replacing the piston 13.

[0149] In some embodiments, the method further comprises:

[0150] Filling the refrigeration cylinder with gas at a first predetermined temperature to raise the temperature in the refrigeration cylinder to a second predetermined temperature;

[0151] Assemble the assembly for completing the maintenance of the piston 13 with the refrigeration cylinder along the installation direction of the piston 13, so that the piston 13 moves into the refrigeration cylinder;

[0152] Sealingly connecting the refrigerator driving unit 12 and the first flange 30;

[0153] The refrigerator 10 is pushed, and the end surface of the cold head 11 is connected to the cold head container 20;

[0154] The first flange 30 and the second flange 40 are sealed and connected.

[0155] Specifically, a dedicated heating device may be used to inject gas of a first predetermined temperature into the cylinder of the refrigerator 10 to raise the temperature of the refrigerator cylinder of the refrigerator 10 to a second predetermined temperature (such as room temperature).

[0156] In a possible implementation, the piston 13 that has been maintained can be reinstalled into the refrigeration cylinder by utilizing the thermal expansion state of the refrigeration cylinder.

[0157] After the piston 13 is reinstalled into the refrigeration cylinder, the first flange 30 and the refrigerator drive unit 12 can be sealed, so that the piston 13 is sealed in the refrigeration cylinder. Then the cold head 11 is installed in the cold head container 20, and the first flange 30 and the second flange 40 are sealed.

[0158] In this way, during the entire maintenance process, the refrigeration chamber is always isolated from the external environment, and there is no need to return the refrigeration chamber to room temperature and then cool it down, thereby saving maintenance time and cost of the refrigeration system 1.

[0159] Here, the above-mentioned embodiment is described with reference to specific examples.

[0160] This example provides a cold head container 20 for a conduction-cooled superconducting magnet and a method of using the cold head container 20, which enables maintenance of the refrigerator piston 13 under low temperature and vacuum conditions, thereby significantly reducing maintenance time.

[0161] The technical solution adopted in this example is: a cold head container 20 for conduction cooling superconducting magnets and its use method, the cold head container 20 includes a room temperature end flange (i.e., the second flange 40), the room temperature end flange is non-magnetic austenitic stainless steel; a primary straight tube (i.e., the first cylindrical container 201), the primary straight tube is a non-magnetic austenitic stainless steel thin-walled tube, the wall thickness is controlled at 0.3-1.0mm; a primary cold conduction block (i.e., the first cold conduction block 211), the primary cold conduction block is high-purity copper; a secondary straight tube (i.e., the second cylindrical container 202), the secondary straight tube is a non-magnetic austenitic stainless steel thin-walled tube, the wall thickness is controlled at 0.3-1.0mm; a secondary cold conduction block (i.e., the second cold conduction block 212), the secondary cold conduction block is high-purity copper. Among them, the room temperature end flange and the primary straight tube are welded together by sealed argon arc welding, the primary straight tube and the primary cold conduction block are sealed brazed, the primary cold conduction block and the secondary straight tube are sealed brazed, and the secondary straight tube and the secondary cold conduction block are sealed brazed. The cold head container 20 is used in conjunction with a refrigerator, and a sealing ring is arranged between the refrigerator (refrigerator flange, i.e., the first flange 30) and the cold head container 20 flange to form a sealed cavity. Inside the cold head container 20, the first level of the refrigerator (i.e., the first level cylindrical cylinder 111) and the first level cold conduction block of the cold head container 20 are crimped with indium sheets for cooling; the second level of the refrigerator (i.e., the second level cylindrical cylinder 112) and the second level cold conduction block of the cold head container 20 are crimped with indium wires for cooling. Outside the cold head container 20, a sealing ring is arranged on the room temperature end flange of the cold head container 20 and the room temperature end flange of the superconducting magnet (i.e., the third flange 80) and connected by screws. The first level cold conduction block and the second level cold conduction block of the cold head container 20 are respectively connected to the 50K cold mass and 4K cold mass of the superconducting magnet through flexible cold conduction belts for cold transfer.

[0162] The main purpose of this example is to maintain the piston 13 of the refrigerator at low temperature, thereby reducing maintenance time and improving production efficiency. When the piston 13 of the refrigerator needs maintenance, the operation steps are as follows:

[0163] Step 1: Loosen the connecting screws between the refrigerator flange (first flange 30) and the cold head container 20 flange (second flange 40), and lift the refrigerator as a whole by 3-5 mm, in order to separate the first and second stages of the refrigerator (first-stage cylindrical cylinder 111, second-stage cylindrical cylinder 112) from the cold mass;

[0164] Step 2: Loosen the screw fasteners on the refrigerator body structure to loosen the refrigerator piston 13 from the refrigerator cylinder (refrigeration cylinder), and take out the refrigerator piston 13;

[0165] The third step is to use a dedicated heating device to blow hot air into the refrigerator cylinder to quickly raise the refrigerator cylinder temperature to normal temperature;

[0166] Step 4: When the temperature of the refrigerator cylinder rises to room temperature, quickly insert the prepared new piston 13 into the cylinder to fix the refrigerator body fastener;

[0167] Step 5: Use special tooling to press the refrigerator back, lock the connecting screws between the refrigerator flange and the cold head container 20 flange, and start cooling.

[0168] It should be noted that the heat exchange system embodiment based on eddy current technology and the control method embodiment of the heat exchange system based on eddy current technology provided in the present application belong to the same concept; the technical features in the technical solutions recorded in each embodiment can be combined arbitrarily without conflict.

[0169] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present application that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present application and do not limit the scope of protection of the patent of this application.

Claims

1. A refrigeration system, characterized in that: The refrigeration system comprises: a refrigerator having a cold head, a cold head container and a refrigeration chamber surrounded by a shell; A first flange is arranged around the cold head, a second flange is arranged at the opening of the cold head container, the cold head is loaded into the cold head container from the opening of the cold head container, the first flange and the second flange are detachably sealed and connected, and the cold head is sealed in the cold head container; The shell is provided with an opening connected to the refrigeration chamber, the cold head container is seated in the opening of the shell through the second flange, so that the cold head container extends into the refrigeration chamber, and the outer wall of the second flange and the opening of the shell form a seal, so that the internal space of the cold head container is sealed and isolated from the refrigeration chamber; When the cold head is installed in the cold head container, the end surface of the cold head is connected to the cold head container to conduct cold to the cooling target in the refrigeration chamber.

2. The refrigeration system according to claim 1, characterized in that: The refrigerator comprises: a refrigerator drive unit, a piston and a refrigeration cylinder as the cold head, wherein the piston is driven by the refrigerator drive unit to move axially in the refrigeration cylinder to cool; the cold head end surface comprises the bottom end surface of the refrigeration cylinder; The first flange is arranged at the open end of the refrigeration cylinder, and the first flange is sealedly connected to the refrigerator drive unit to seal the piston in the refrigeration cylinder; The cold head container includes a cold conduction block; The cooling block at least includes a cooling surface for conducting cooling from the bottom end of the refrigeration cylinder to the cooling target object.

3. The refrigeration system according to claim 2, characterized in that: The refrigeration cylinder comprises a first-stage cylindrical cylinder and a second-stage cylindrical cylinder which are connected to each other, the first flange is arranged at the first end of the first-stage cylindrical cylinder, the second end of the first-stage cylindrical cylinder is connected to the first end of the second-stage cylindrical cylinder, and the radial cross-sectional area of ​​the second-stage cylindrical cylinder is smaller than the radial cross-sectional area of ​​the first-stage cylindrical cylinder; The bottom end surface of the refrigeration cylinder includes a first end surface outside the connection portion between the second end surface of the first-stage cylindrical cylinder and the second-stage cylindrical cylinder, and a second end surface of the second end of the second-stage cylindrical cylinder; The cold head container comprises a first cylindrical container and a second cylindrical container, which are respectively adapted to the first cylindrical cylinder and the second cylindrical cylinder; the second flange is arranged at the first end of the first cylindrical container; The cooling block comprises: a first cooling block between the second end of the first cylindrical container and the first end of the second cylindrical container; and a second cooling block disposed at the second end of the second cylindrical container; The first cooling block at least comprises a first cooling surface for conducting cooling from the first end surface; The second cooling block at least includes a second cooling surface for conducting cooling from the second end surface.

4. The refrigeration system according to claim 3, characterized in that: The first cooling block is sealed to the second end of the first cylindrical container, the first cooling block is sealed to the first end of the second cylindrical container, and the second cooling block is sealed to the second end of the second cylindrical container, so that the cold head container is airtight.

5. The refrigeration system according to claim 4, characterized in that: A first indium layer is provided between the first end surface and the first cold conducting surface. and / or A second indium layer is disposed between the second end surface and the second cold conducting surface.

6. The refrigeration system according to claim 5, characterized in that: The first indium layer is formed of an indium sheet, and / or the second indium layer is formed of an indium wire.

7. The refrigeration system according to claim 1, characterized in that: The first flange has an annular boss extending along the axis direction of the cold head; The second flange has an annular groove matched with the boss; The end surface of the boss and the bottom surface of the groove cooperate to form the sealing surface of the sealed connection, and / or the outer side surface of the boss and the inner side surface of the groove cooperate to form the sealing surface.

8. The refrigeration system according to claim 7, characterized in that: A sealing ring is arranged between the outer side surface of the boss and the inner side surface of the groove.

9. The refrigeration system according to claim 1, characterized in that: The first flange has a first annular disk extending radially along the cold head; The second flange has a second annular disk extending radially along the cold head; The first annular disk and the second annular disk are connected by bolts, so that the first flange is sealed and connected to the second flange.

10. A refrigeration system maintenance method, characterized in that: Applied to the refrigeration system according to any one of claims 1 to 9, the method comprises: The sealing connection between the first flange and the second flange is opened, and the refrigerator is moved a predetermined distance in the opposite direction of the cold head installation to the cold head container, so that the cold head end surface is disconnected from the cold head container and the cold head is at least partially located in the cold head container.

11. The refrigeration system maintenance method according to claim 10, characterized in that: The refrigerator comprises: a refrigerator drive unit, a piston and a refrigeration cylinder as the cold head, wherein the piston is driven by the refrigerator drive unit to move axially in the refrigeration cylinder to cool; the cold head end surface comprises the bottom end surface of the refrigeration cylinder; the first flange is arranged at the open end of the cylinder, and the first flange is sealedly connected with the refrigerator drive unit to seal the piston in the refrigeration cylinder; the cold head container comprises a cooling block; the cooling block at least comprises a cooling surface for conducting cooling from the bottom end surface of the refrigeration cylinder to the cooling target object; The method further comprises: Separating the refrigerator drive unit and the first flange, and moving the assembly consisting of the refrigerator drive unit and the piston in the reverse installation direction of the piston to move the piston out of the refrigeration cylinder; The piston is maintained.

12. The refrigeration system maintenance method according to claim 11, characterized in that: The method further comprises: Filling the refrigeration cylinder with gas at a first predetermined temperature to raise the temperature in the refrigeration cylinder to a second predetermined temperature; Assembling the assembly for completing piston maintenance with the refrigeration cylinder along the installation direction of the piston, so that the piston moves into the refrigeration cylinder; Sealingly connecting the refrigerator drive unit and the first flange; The refrigerator is pushed, and the end surface of the cold head is connected to the cold head container; The first flange and the second flange are sealed and connected.

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