Cold head mounting structure and cooling device

Abstract

The utility model relates to a cold head mounting structure and a cooling device. The cold head installation structure comprises a cold head cavity and an elastic heat conduction mechanism. The cold head cavity is provided with a sealing end, the sealing end is used for separating the cold head cavity from the refrigerant bin, and a cold head is arranged in the cold head cavity. The elastic heat conduction mechanism comprises an elastic piece and a transition heat conduction piece, the transition heat conduction piece is connected with the inner wall of the cold head cavity through the elastic piece, and the transition heat conduction piece is used for abutting against the cold head so that the cold head can keep thermal contact with the inner wall of the cold head cavity. The cold head cavity and the refrigerant bin body are separated by the sealing end, so that the cold head can be directly taken out from the cold head cavity during maintenance, and liquid helium cannot be leaked from the cold head cavity. In addition, the elastic heat conduction mechanism comprises an elastic piece and a transition heat conduction piece, when the cold head stretches into the cold head cavity, due to the elastic effect of the elastic piece, the cold head can make thermal contact with the transition heat conduction piece all the time in the working period, and then the refrigeration efficiency of the cold head is guaranteed.

Description

Technical Field

[0001] The present application relates to the field of magnetic resonance imaging technology, and in particular to a cold head mounting structure and a cooling device. Background Art

[0002] In superconducting magnetic resonance imaging (MRI), most magnets achieve superconductivity by immersing the superconducting coils in liquid helium. This liquid helium superconducting magnet system features a cryogen chamber containing the liquid helium. Liquid helium is injected into the chamber to control the ambient temperature of the superconducting coils, generating a highly stable, high-strength magnetic field. The magnet utilizes a multi-layer vacuum insulation structure. However, due to various factors, such as structural support and the connectivity of current leads, it is impossible to completely prevent heat conduction. Therefore, the liquid helium evaporates and dissipates the introduced heat to maintain a temperature of 4.2K. To minimize evaporation of the liquid helium, superconducting nuclear magnetic resonance (NMR) instruments are typically equipped with a refrigeration system to provide cooling and reduce evaporation.

[0003] In related technologies, the refrigeration system includes three parts: a cold head, a compressor, and a water-cooling unit. The cold head is a refrigeration component that provides two levels of low temperature, 50K and 4K, for the superconducting magnet. The first level is used to maintain a low temperature of 50K cold shield to reduce the radiation heat transfer between the liquid helium temperature and the room temperature. The second level is used to liquefy helium into liquid helium. The cold head is generally arranged in a cold head cavity connected to the refrigerant tank.

[0004] However, due to the limited life of the cold head, it generally needs to be maintained once every 10,000 hours. During maintenance, the cold head needs to be removed. At this time, the helium in the refrigerant tank will be discharged through the cold head cavity, resulting in the loss of a large amount of liquid helium and the risk of frostbite to the operator. Utility Model Content

[0005] Based on this, it is necessary to provide a cold head installation structure and a cooling device to address the problem of helium leakage in the cold head cavity during cold head maintenance.

[0006] A cold head mounting structure is applicable to a magnetic resonance cooling device, wherein the magnetic resonance cooling device comprises an outer container, a refrigerant tank disposed inside the outer container, and a cold head at least partially disposed on the outer container. The cold head mounting structure comprises:

[0007] A cold head cavity having a sealed end, the sealed end being used to isolate the cold head cavity from the refrigerant chamber, and a cold head being arranged in the cold head cavity; and

[0008] The elastic heat-conducting mechanism includes an elastic member and a transition heat-conducting member. The transition heat-conducting member is connected to the inner wall of the cold head cavity through the elastic member. The transition heat-conducting member is used to abut against the cold head so that the cold head maintains thermal contact with the inner wall of the cold head cavity.

[0009] In one embodiment, the cold head cavity includes a primary cavity and a secondary cavity that are interconnected, and the primary cavity and / or the secondary cavity are in thermal contact with the cold head through the elastic heat conductive mechanism.

[0010] In one embodiment, the primary cavity is in thermal contact with the primary cold head on the cold head through the elastic heat-conducting mechanism, and the secondary cavity is in direct thermal contact with the secondary cold head on the cold head.

[0011] In one embodiment, the diameter of the primary cavity is greater than the diameter of the secondary cavity, so that a step surface is formed between the primary cavity and the secondary cavity, and the elastic heat-conducting mechanism is arranged on the step surface.

[0012] In one embodiment, a primary heat conductor is provided on the step surface, one end of the elastic member away from the transition heat conductor is connected to the primary heat conductor, and the transition heat conductor and the primary heat conductor are connected via the first heat conducting belt.

[0013] In one embodiment, the sealing end is located at an end of the secondary cavity away from the primary cavity, and a secondary heat conductive member is provided on the sealing end, and the secondary heat conductive member is used to directly make thermal contact with the secondary cold head.

[0014] In one embodiment, the secondary cavity is in thermal contact with the secondary cold head on the cold head through the elastic heat-conducting mechanism, and the primary cavity is in direct thermal contact with the primary cold head on the cold head.

[0015] In one embodiment, the sealing end is located at an end of the secondary cavity away from the primary cavity, and a secondary heat conducting member is provided on the sealing end;

[0016] One end of the elastic member away from the transition heat conductive member is connected to the secondary heat conductive member, the transition heat conductive member and the secondary heat conductive member are connected via a first heat conductive belt, and the transition heat conductive member is used for thermal contact with the secondary cold head.

[0017] In one embodiment, the cold head mounting structure includes a cold head flange, the cold head is connected to the cold head flange, and the cold head flange is connected to the cold head cavity through an adjusting nut.

[0018] A magnetic resonance cooling device comprises a cold head and a cold head mounting structure, wherein the cold head is used to extend into the cold head cavity.

[0019] The above-mentioned cold head installation structure and cooling device are characterized by a cold head disposed within a cold head cavity. The sealed end of the cold head cavity is configured to extend into the refrigerant tank, thereby maintaining the temperature of the refrigerant tank at 4.2K. Simultaneously, the sealed end isolates the cold head cavity from the refrigerant tank, allowing the cold head to be removed directly from the cold head cavity during maintenance without causing leakage of liquid helium from the cold head cavity. Furthermore, the elastic heat-conducting mechanism includes an elastic member and a transition heat-conducting member. When the cold head is inserted into the cold head cavity, the elastic action of the elastic member ensures that the cold head remains in thermal contact with the transition heat-conducting member during operation, thereby ensuring the cold head's cooling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of a cooling device in one embodiment.

[0021] Figure 2 Schematic diagram of the structure in which a cold head is installed in a cold head cavity in one embodiment.

[0022] Figure 3 for Figure 2 Schematic diagram of the structure of the intercooler cavity.

[0023] Figure 4 Schematic diagram of the structure in which a cold head is installed in a cold head cavity in another embodiment.

[0024] Figure 5 for Figure 4 Schematic diagram of the structure of the intercooler cavity.

[0025] Figure numerals: 100, cold head cavity; 110, primary cavity; 120, secondary cavity; 130, primary heat conductive part; 140, secondary heat conductive part; 150, sealing end; 200, cold head; 210, primary cold head; 220, secondary cold head; 230, cold conductive seat; 240, cold head flange; 300, elastic heat conductive mechanism; 310, elastic part; 320, transition heat conductive part; 330, first thermal conductive belt; 410, outer container; 420, cold screen; 430, superconducting coil; 440, refrigerant tank; 450, second thermal conductive belt. DETAILED DESCRIPTION

[0026] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0027] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0028] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0029] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0030] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions, this may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is described as being "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is described as being "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0031] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0032] See Figure 1-Figure 5 A cold head mounting structure provided in one embodiment of the present application is suitable for use in a magnetic resonance cooling device. The magnetic resonance cooling device comprises an outer container 410, a refrigerant tank 440 disposed within the outer container 410, and a cold head 200 at least partially disposed on the outer container 410. The cold head mounting structure includes a cold head cavity 100 and an elastic heat-conducting mechanism 300. The cold head cavity 100 has a sealed end 150, which is configured to extend into the refrigerant tank 440 to isolate the cold head cavity 100 from the refrigerant tank 440. The cold head 200 is disposed within the cold head cavity 100. The elastic heat-conducting mechanism 300 includes an elastic member 310 and a transitional heat-conducting member 320. The transitional heat-conducting member 320 is connected to the inner wall of the cold head cavity 100 via the elastic member 310. The transitional heat-conducting member 320 is configured to abut against the cold head 200 to maintain thermal contact between the cold head 200 and the inner wall of the cold head cavity 100.

[0033] In this embodiment, the cold head 200 is disposed within the cold head cavity 100. The sealed end 150 of the cold head cavity 100 is configured to extend into the refrigerant tank 440 to maintain the temperature of the refrigerant tank 440 at 4.2K. Simultaneously, the sealed end 150 isolates the cold head cavity 100 from the refrigerant tank 440. During maintenance, the cold head 200 can be directly removed from the cold head cavity 100 without causing liquid helium to leak from the cold head cavity 100. Furthermore, the elastic heat-conducting mechanism 300 includes an elastic member 310 and a transition heat-conducting member 320. When the cold head 200 extends into the cold head cavity 100, the elastic action of the elastic member 310 allows the cold head 200 to always abut against the transition heat-conducting member 320 within the cold head cavity 100 during operation, thereby ensuring efficient heat transfer between the cold head 200 and the sidewalls of the cold head cavity 100.

[0034] The elastic member 310 may be a spring or a spring. The refrigerant tank body 440 may be a liquid helium tank body or a liquid nitrogen tank body. Preferably, the refrigerant tank body 440 is a liquid helium tank body for storing liquid helium.

[0035] See Figure 1-Figure 4In some embodiments, the cold head cavity 100 includes a primary cavity 110 and a secondary cavity 120 that are interconnected, and the primary cavity 110 and / or the secondary cavity 120 are in thermal contact with the cold head 200 through an elastic heat conducting mechanism 300 .

[0036] The cold head cavity 100 includes a primary cavity 110 and a secondary cavity 120 that are interconnected. The cold head 200 has a primary cold head 210 and a secondary cold head 220 that are connected in sequence. When in use, the primary cold head 210 extends into the primary cavity 110 to be in thermal contact with the primary cavity 110. The outer wall of the primary cavity 110 is connected to the cold shield 420 through the second thermal conductive tape 450, that is, the primary cold head 210 can cool the cold shield 420 to maintain the temperature of the cold shield 420 at 50K, so as to reduce the radiation heat transfer between the liquid helium temperature and room temperature. The secondary cold head 220 extends into the secondary cavity 120 to be in thermal contact with the secondary cavity 120. The end of the secondary cavity 120 away from the primary cavity 110 extends into the refrigerant tank body 440, or is flush with the refrigerant tank body 440, that is, the secondary cold head 220 is used to cool the refrigerant tank body 440 to maintain the temperature of the refrigerant tank body 440 at 4.2K.

[0037] Among them, because the first-level cold head 210 and the second-level cold head 220 need to maintain thermal contact with the cold head cavity 100 at the same time, the manufacturing and installation precision requirements of the cold head 200 and the cold head cavity 100 are relatively high, resulting in increased manufacturing costs. The present application provides an elastic heat-conducting mechanism 300, so that the first-level cavity 110 and / or the second-level cavity 120 are in thermal contact with the cold head 200 through the elastic heat-conducting mechanism 300, thereby effectively reducing the manufacturing and installation precision requirements of the cold head 200 and the cold head cavity 100, while reducing costs and ensuring the cooling efficiency of the cold head 200.

[0038] In some embodiments, the cold head mounting structure includes a cold head flange 240 , the cold head 200 is connected to the cold head flange 240 , and the cold head flange 240 is connected to the cold head cavity 100 via adjusting bolts.

[0039] In this embodiment, the cold head flange 240 is mounted at the opening of the cold head cavity 100 via adjusting bolts. A sealing ring is provided between the cold head flange 240 and the cold head cavity 100 to seal the cold head cavity 100. The cold head is fixed to the cold head flange 240. By turning the adjusting bolts, the cold head flange 240 can move the cold head 200 up and down, thereby compressing the elastic member 310 and ensuring that the transition heat conducting member 320 abuts against the cold head 200.

[0040] See Figure 2 and Figure 3In some embodiments, the primary cavity 110 is in thermal contact with the primary cold head 210 on the cold head 200 through the elastic heat conducting mechanism 300 , and the secondary cavity 120 is in direct thermal contact with the secondary cold head 220 on the cold head 200 .

[0041] In this embodiment, the elastic heat-conducting mechanism 300 is arranged in the primary cavity 110. When installing the cold head 200, after inserting the cold head 200 into the cold head cavity 100, the adjusting bolt on the cold head flange 240 is rotated until the secondary cold head 220 is in direct contact with the secondary cavity 120. At this time, due to the setting of the elastic part 310, the primary cold head 210 can also be in thermal contact with the transition heat-conducting part 320, thereby ensuring the effective conduction of temperature between the primary cold head 210 and the primary cavity 110.

[0042] Furthermore, the diameter of the primary cavity 110 is greater than the diameter of the secondary cavity 120 , so that a step surface is formed between the primary cavity 110 and the secondary cavity 120 , and the elastic heat-conducting mechanism 300 is disposed on the step surface.

[0043] In this embodiment, the transition heat conductive member 320 is an annular structure, and the transition heat conductive member 320 is supported on the step surface by multiple elastic members 310. The cold head 200 includes a cold conductive seat 230 and a first-level cold head 210 and a second-level cold head 220 that are sequentially arranged outside the cold conductive seat 230. When the second-level cold head 220 is in direct contact with the second-level cavity 120, the first-level cold head 210 squeezes the elastic member 310 through the transition heat conductive member 320 to ensure close contact between the first-level cold head 210 and the transition heat conductive member 320, thereby ensuring the cooling efficiency of the first-level cold head 210.

[0044] Specifically, a primary heat conductor 130 is provided on the step surface, and one end of the elastic member 310 away from the transition heat conductor 320 is connected to the primary heat conductor 130 . The transition heat conductor 320 and the primary heat conductor 130 are connected via a first heat conducting belt 330 .

[0045] In this embodiment, the transitional heat conducting member 320 and the primary heat conducting member 130 are made of copper or aluminum, and the first heat conducting tape 330 can be an elastic or flexible copper tape. The first heat conducting tape 330 can adapt to the extension or contraction of the elastic member 310. The first heat conducting tape 330 connects the transitional heat conducting member 320 and the primary heat conducting member 130 to increase the heat transfer efficiency between them, thereby ensuring the cooling efficiency of the primary cold head 210.

[0046] In some embodiments, the sealing end 150 is located at one end of the secondary cavity 120 away from the primary cavity 110 . A secondary heat conducting member 140 is provided on the sealing end 150 . The secondary heat conducting member 140 is used to directly make thermal contact with the secondary cold head 220 .

[0047] In this embodiment, the secondary heat conductor 140 is made of copper and is sealed to the secondary cavity 120 to form a sealed end 150. When installing the cold head 200, after inserting the cold head 200 into the cold head cavity 100, turn the adjustment bolt on the cold head flange 240 until the secondary cold head 220 is in direct contact with the secondary heat conductor 140.

[0048] See Figure 4 and Figure 5 In some other embodiments, the secondary cavity 120 is in thermal contact with the secondary cold head 220 on the cold head 200 through the elastic heat conducting mechanism 300 , and the primary cavity 110 is in direct thermal contact with the primary cold head 210 on the cold head 200 .

[0049] In this embodiment, the elastic heat-conducting mechanism 300 is arranged in the secondary cavity 120. When installing the cold head 200, after inserting the cold head 200 into the cold head cavity 100, the adjusting bolt on the cold head flange 240 is rotated until the first-level cold head 210 is in direct contact with the first-level cavity 110. At this time, due to the setting of the elastic part 310, the second-level cold head 220 can also be in thermal contact with the transition heat-conducting part 320, thereby ensuring the effective conduction of temperature between the second-level cold head 220 and the second-level cavity 120.

[0050] Furthermore, the sealing end 150 is located at one end of the secondary cavity 120 away from the primary cavity 110, and a secondary heat conductor 140 is provided on the sealing end 150; the end of the elastic member 310 away from the transition heat conductor 320 is connected to the secondary heat conductor 140, and the transition heat conductor 320 is connected to the secondary heat conductor 140 through the first heat conductor belt 330, and the transition heat conductor 320 is used for thermal contact with the secondary cold head 220.

[0051] Specifically, the transition heat conductive member 320 is supported on the secondary heat conductive member 140 by a plurality of elastic members 310. When the cold head 200 is installed, the secondary cold head 220 can squeeze the elastic member 310 through the transition heat conductive member 320. Under the action of the elastic member 310, the secondary cold head 220 can be in close contact with the transition heat conductive member 320, thereby ensuring the cooling efficiency of the secondary cold head 220.

[0052] An embodiment of the present application further provides a magnetic resonance cooling device, including a cold head 200 and a cold head mounting structure, wherein the cold head 200 is configured to extend into the cold head cavity 100 .

[0053] The magnetic resonance cooling device also includes an outer container 410, a cold shield 420, a superconducting coil 430, a refrigerant tank 440, and a second heat-conducting tape 450. The cold head cavity 100 is welded to the outer container 410, and the cold head 200 is placed within the cold head cavity 100. The primary heat-conducting element 130 of the cold head cavity 100 is connected to the cold shield 420 via the second heat-conducting tape 450, maintaining the temperature of the cold shield 420 at 50K to reduce radiative heat transfer between the liquid helium temperature and room temperature. The superconducting coil 430 is immersed in the refrigerant tank 440, and the sealed end 150 of the cold head cavity 100 (i.e., the secondary heat-conducting element 140) extends into the refrigerant tank 440 to maintain the temperature of the liquid helium in the refrigerant tank 440 at 4.2K. The outer container 410 and the refrigerant tank 440 each have a double-layer high-vacuum shell, which blocks convective heat transfer between the superconducting coil 430 and the interior of the container.

[0054] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0055] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A cold head mounting structure, suitable for a magnetic resonance cooling device, the magnetic resonance cooling device comprising an outer container (410), a refrigerant tank (440) disposed inside the outer container (410), and a cold head (200) at least partially disposed on the outer container (410), characterized in that: The cold head mounting structure includes: A cold head cavity (100) has a sealed end (150), the sealed end (150) is used to block the cold head cavity (100) from the refrigerant chamber (440), and the cold head (200) is arranged in the cold head cavity (100); The elastic heat-conducting mechanism (300) comprises an elastic member (310) and a transition heat-conducting member (320), wherein the transition heat-conducting member (320) is connected to the inner wall of the cold head cavity (100) through the elastic member (310), and the transition heat-conducting member (320) is used to abut against the cold head (200) so that the cold head (200) maintains thermal contact with the inner wall of the cold head cavity (100).

2. The cold head mounting structure according to claim 1, wherein: The cold head cavity (100) comprises a primary cavity (110) and a secondary cavity (120) that are interconnected, and the primary cavity (110) and / or the secondary cavity (120) are in thermal contact with the cold head (200) via the elastic heat conduction mechanism (300).

3. The cold head mounting structure according to claim 2, characterized in that: The primary cavity (110) is in thermal contact with the primary cold head (210) on the cold head (200) via the elastic heat-conducting mechanism (300), and the secondary cavity (120) is in direct thermal contact with the secondary cold head (220) on the cold head (200).

4. The cold head mounting structure according to claim 3, characterized in that: The diameter of the primary cavity (110) is greater than the diameter of the secondary cavity (120), so that a step surface is formed between the primary cavity (110) and the secondary cavity (120), and the elastic heat-conducting mechanism (300) is arranged on the step surface.

5. The cold head mounting structure according to claim 4, characterized in that: A primary heat conducting member (130) is provided on the step surface, one end of the elastic member (310) away from the transition heat conducting member (320) is connected to the primary heat conducting member (130), and the transition heat conducting member (320) and the primary heat conducting member (130) are connected via a first heat conducting belt (330).

6. The cold head mounting structure according to claim 3, characterized in that: The sealing end (150) is located at one end of the secondary cavity (120) away from the primary cavity (110), and a secondary heat conducting member (140) is provided on the sealing end (150), and the secondary heat conducting member (140) is used to directly make thermal contact with the secondary cold head (220).

7. The cold head mounting structure according to claim 2, wherein: The secondary cavity (120) is in thermal contact with the secondary cold head (220) on the cold head (200) through the elastic heat-conducting mechanism (300), and the primary cavity (110) is in direct thermal contact with the primary cold head (210) on the cold head (200).

8. The cold head mounting structure according to claim 7, characterized in that: The sealing end (150) is located at an end of the secondary cavity (120) away from the primary cavity (110), and a secondary heat conducting member (140) is provided on the sealing end (150); One end of the elastic member (310) away from the transition heat conductive member (320) is connected to the secondary heat conductive member (140), the transition heat conductive member (320) and the secondary heat conductive member (140) are connected via a first heat conductive belt (330), and the transition heat conductive member (320) is used for thermal contact with the secondary cold head (220).

9. The cold head mounting structure according to claim 1, wherein: The cold head mounting structure comprises a cold head flange (240), the cold head (200) is connected to the cold head flange (240), and the cold head flange (240) is connected to the cold head cavity (100) via an adjusting bolt.

10. A cooling device, characterized in that: It comprises a cold head (200) and the cold head mounting structure according to any one of claims 1 to 9, wherein the cold head (200) is used to extend into the cold head cavity (100).

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