Vertical measurement Dewar with low heat leakage

Abstract

The invention relates to a vertical measurement Dewar with low heat leakage. Comprising an outer cylinder, an inner cylinder, a flange plate and a cold shield, the inner cylinder body is coaxially arranged in the outer cylinder body, the top of the inner cylinder body is connected with the top of the outer cylinder body through the flange plate, and the inner cylinder body is used for containing low-temperature liquid; the cold shield is arranged between the inner barrel and the outer barrel, and the top end of the cold shield is in sealed connection with the outer wall of the inner barrel in a preset height range through a partition assembly; the preset height range is located between the flange plate and the highest liquid level of the low-temperature liquid, and the temperature of the inner barrel at the connecting position is larger than that of the cold screen; the bottom end face of the flange plate is vertically connected with a plurality of hanging rods, the upper portions of the hanging rods are provided with a plurality of layers of radiation baffles, the bottom ends of the hanging rods are connected with an object to be measured, and the object to be measured is soaked in the low-temperature liquid. The device is low in heat leakage, and can provide a low-temperature environment for a to-be-measured object.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure vessels, in particular to a low heat leakage vertical measurement dewar. Background Art

[0002] Superconductors exhibit zero resistance and complete diamagnetism below their critical temperature and critical magnetic field. To test their performance, they must be cooled below this critical temperature. During testing, the superconducting magnet under test is immersed in liquid helium. A cryostat provides the necessary low-temperature environment for the superconducting magnet and cavity, forming a complete testing setup along with related cryogenic equipment. Therefore, the temperature within the cryostat directly impacts the test results.

[0003] However, the existing vertical test dewar has high heat leakage, which leads to high temperature inside the dewar, affecting the test effect of the superconducting magnet or superconducting cavity test equipment.

[0004] Therefore, there is an urgent need to provide a low heat leakage vertical measurement dewar to solve the above technical problems. Summary of the Invention

[0005] The embodiment of the present invention provides a low heat leakage vertical measurement dewar, which has low heat leakage and can provide a low temperature environment for an object to be measured.

[0006] One embodiment of the present invention provides a low heat leakage vertical detection dewar, comprising:

[0007] Outer cylinder, inner cylinder, flange and cold shield;

[0008] The inner cylinder is coaxially arranged inside the outer cylinder, the tops of the inner cylinder and the outer cylinder are connected via the flange, and the inner cylinder is used to contain cryogenic liquid;

[0009] The cold shield is disposed between the inner cylinder and the outer cylinder, and the top end of the cold shield is sealedly connected to the outer wall of the inner cylinder within a preset height range through a partition assembly; the preset height range is located between the flange and the highest liquid level of the cryogenic liquid, and the temperature of the inner cylinder at the connection position is greater than the temperature of the cold shield;

[0010] The bottom end surface of the flange is vertically connected to a plurality of suspension rods, the upper portion of the suspension rods is provided with a multi-layer radiation baffle, the bottom end of the suspension rod is connected to an object to be tested, and the object to be tested is immersed in the cryogenic liquid.

[0011] In one possible design, the partition assembly includes: a support reinforcement ring, a copper plate, and a cold shield connecting ring, wherein the cross-sections of the support reinforcement ring and the cold shield connecting ring are both L-shaped;

[0012] One end face of the cold screen connecting ring is sealed with the inner wall of the cold screen, and the copper plate and one end face of the support reinforcement ring are arranged in sequence on the other end face, and the end face of the cold screen connecting ring, the copper plate and the end face of the support reinforcement ring are fixedly connected by bolts; the other end face of the support reinforcement ring is sealed with the outer wall of the inner cylinder.

[0013] In a possible design, the partition assembly further includes a copper sheet disposed between the copper plate and the end face of the cold shield connecting ring.

[0014] In a possible design, the thickness of the copper sheet is no more than 1 mm.

[0015] In a possible design, the thickness of the copper plate is not less than 5 mm.

[0016] In a possible design, the support reinforcement ring and the copper plate are fastened by rivets at the non-bolt fastening portion.

[0017] In a possible design, each layer of the radiation baffle is provided with a plurality of first through holes, wherein the diameter of the first through holes is larger than the diameter of the suspension rod;

[0018] Each radiation baffle is sleeved on a suspension rod through a corresponding first through hole. Each layer of radiation baffle is separated by a polyfluoroethylene sleeve. The polyfluoroethylene sleeve at the bottom layer is locked on the corresponding suspension rod through a locking ring.

[0019] In a possible design, the radial edge of each radiation baffle is provided with aluminum foil tape, so that the gap between the radiation baffle and the inner cylinder is filled with the aluminum foil tape.

[0020] In a possible design, the radiation shield is further provided with a plurality of second through holes for connecting wires to pass through.

[0021] In a possible design, a circular disk riveted with rivets is provided around each of the second through holes, and the diameter of the circular disk is larger than the diameter of the second through hole;

[0022] The circular disk can rotate around the rivet. When no connecting wire passes through the second through hole, the circular disk is rotated so as to cover the second through hole.

[0023] An embodiment of the present invention provides a low-heat-leakage vertical-sensing dewar. By connecting the top of the cold shield to the inner cylinder wall between the flange cover and the highest liquid level, rather than connecting the top of the cold shield to the flange cover, heat leakage from the cold shield can be reduced. Furthermore, the inner cylinder temperature at the connection point between the cold shield and the inner cylinder is higher than the cold shield temperature, which can be transferred to the inner cylinder, further reducing heat leakage from the inner cylinder. Thus, the vertical-sensing dewar provided by this application has low heat leakage and can provide a relatively low-temperature environment for the object being measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic diagram of the overall structure of a low heat leakage vertical measurement dewar provided by one embodiment of the present invention;

[0026] Figure 2 for Figure 1 A schematic diagram of the partially enlarged structure of the partition assembly at point A in the middle;

[0027] Figure 3 A schematic cross-sectional view of each layer of radiation baffles and suspension rods provided in one embodiment of the present invention;

[0028] Figure 4 for Figure 3 A partial enlarged view of point B in the middle;

[0029] Figure 5 A schematic diagram of the three-dimensional structure of radiation barriers and suspension rods at each layer provided in one embodiment of the present invention;

[0030] Figure 6 A schematic diagram of a disc not covering the second through hole provided by an embodiment of the present invention;

[0031] Figure 7 This is a schematic diagram of a circular disc covering a second through hole provided by an embodiment of the present invention.

[0032] Reference numerals:

[0033] 1-Outer cylinder;

[0034] 2-Inner cylinder;

[0035] 3- flange;

[0036] 4-Cold screen;

[0037] 5- Partition assembly;

[0038] 51-support reinforcement ring; 52-copper plate; 53-cold shield connecting ring; 54-copper sheet; 55-bolt; 56-rivet;

[0039] 6- boom;

[0040] 7-Radiation baffle;

[0041] 71-second through hole; 72-disc;

[0042] 8-PTFE casing;

[0043] 9-Aluminum foil tape;

[0044] 10-Locking ring

[0045] 11-Connecting wire. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0047] As mentioned above, the existing vertical dewar has a high heat leakage, mainly due to the fact that the cold shield (4) is directly connected to the flange cover and the heat leakage between the radiation partitions is large. Based on the above reasons, the inventors have proposed a new vertical dewar to reduce heat leakage.

[0048] like Figure 1 As shown, an embodiment of the present invention provides a low heat leakage vertical detection dewar, comprising:

[0049] Outer cylinder 1, inner cylinder 2, flange 3 and cold shield 4;

[0050] The inner cylinder 2 is coaxially arranged inside the outer cylinder 1. The tops of the inner cylinder 2 and the outer cylinder 1 are connected by a flange 3. The inner cylinder 2 is used to contain cryogenic liquid.

[0051] The cold shield 4 is arranged between the inner cylinder 2 and the outer cylinder 1. The top of the cold shield 4 is sealedly connected to the outer wall of the inner cylinder 2 within a preset height range through the partition assembly 5. The preset height range is between the flange 3 and the highest liquid level of the cryogenic liquid. The temperature of the inner cylinder 2 at the connection position is higher than the temperature of the cold shield 4.

[0052] The bottom end surface of the flange 3 is vertically connected to a plurality of suspension rods 6 , the upper portion of the suspension rods 6 is provided with a multi-layer radiation baffle 7 , the bottom end of the suspension rods 6 is connected to an object to be tested, and the object to be tested is immersed in the cryogenic liquid.

[0053] In this embodiment, by connecting the top of the cold shield 4 to the wall of the inner cylinder 2 between the flange cover and the highest liquid level, rather than connecting the top of the cold shield 4 to the flange cover, heat leakage from the cold shield 4 can be reduced. Furthermore, the temperature of the inner cylinder 2 at the connection point between the cold shield 4 and the inner cylinder 2 is higher than that of the cold shield 4, which can transfer the temperature of the cold shield 4 to the inner cylinder 2, further reducing heat leakage from the inner cylinder 2. Thus, the vertical measurement dewar provided by this application has low heat leakage and can provide a relatively low temperature environment for the object to be measured.

[0054] It should be noted that the temperature distribution of the inner cylinder 2 between the flange cover and the highest liquid level is obtained through simulation calculations. Furthermore, the cryogenic liquid may be, for example, 4K liquid helium. This application does not specifically limit the type and temperature of the cryogenic medium. The measured object may be, for example, a superconducting magnet or superconducting cavity.

[0055] In some embodiments, the partition assembly 5 includes: a support reinforcement ring 51, a copper plate 52, and a cold shield connecting ring 53, wherein the cross sections of the support reinforcement ring 51 and the cold shield connecting ring 53 are both L-shaped;

[0056] One end face of the cold shield connecting ring 53 is sealed with the inner wall of the cold shield 4, and the copper plate 52 and one end face of the support reinforcement ring 51 are arranged in sequence on the other end face, and the end face of the cold shield connecting ring 53, the copper plate 52 and the end face of the support reinforcement ring 51 are fixedly connected by bolts 55; the other end face of the support reinforcement ring 51 is sealed with the outer wall of the inner cylinder 2.

[0057] In this embodiment, the provision of a partition assembly 5 reduces heat leakage from the inner cylinder 2. Furthermore, the copper plate 52 is preferably thick, for example, not less than 5 mm, to enhance structural stability. Furthermore, the end faces of the cold shield 4 and the cold shield connecting ring 53 can also be secured with bolts 55 or rivets 56 to enhance heat transfer.

[0058] In some embodiments, the partition assembly 5 further includes a copper sheet 54 disposed between the copper plate 52 and the end surface of the cold shield connecting ring 53 .

[0059] In this embodiment, a gap may exist between the copper plate 52 and the end surface of the cold shield connecting ring 53, which could affect heat conduction. Therefore, adding a thin copper sheet 54 between the copper plate 52 and the end surface of the cold shield connecting ring 53 effectively fills the gap and improves heat transfer. Furthermore, the thickness of the copper sheet 54 is no greater than 1 mm, preferably 0.5 mm.

[0060] In some embodiments, the support reinforcement ring 51 and the copper plate 52 are riveted together at the non-bolt fastening portion by rivets 56 .

[0061] In this embodiment, by providing rivets 56 in the above-mentioned area, the thick copper plate 52 and the support reinforcement ring 51 can be fully contacted to ensure the heat transfer effect.

[0062] It should be noted that the support reinforcement ring 51 and the cold shield connection ring 53 are preferably made of materials with good thermal conductivity, which is not specifically limited here.

[0063] In some embodiments, each layer of radiation barrier 7 is provided with a plurality of first through holes, and the diameter of the first through holes is larger than the diameter of the suspension rod 6;

[0064] Each radiation baffle 7 is sleeved on a suspension rod 6 through the corresponding first through hole. Each layer of radiation baffle 7 is separated by a polytetrafluoroethylene sleeve 8. The polytetrafluoroethylene sleeve 8 on the bottom layer is locked on the corresponding suspension rod 6 by a locking ring 10.

[0065] In this embodiment, the diameter of the first through hole is larger than the diameter of the suspension rod 6, so that the suspension rod 6 does not contact the radiation baffle 7, reducing heat transfer to the outside along the suspension rod 6 and reducing heat leakage loss. The locking ring 10 can prevent the heat insulation baffle from falling off.

[0066] In some embodiments, the radial edge of each radiation baffle 7 is provided with aluminum foil tape 9 to fill the gap between the radiation baffle 7 and the inner cylinder 2 through the aluminum foil tape 9 to reduce heat leakage.

[0067] In some embodiments, the radiation shield 7 is further provided with a plurality of second through holes 71 for the connection wires 11 to pass through.

[0068] In some embodiments, a disk 72 riveted with rivets 56 is provided around each second through hole 71 , and the diameter of the disk 72 is larger than the diameter of the second through hole 71 ;

[0069] The disk 72 can rotate around the rivet. When no connecting wire 11 passes through the second through hole 71 , the disk 72 is rotated so as to cover the second through hole 71 .

[0070] In the above embodiment, the disk 72 is provided to prevent heat from leaking outward along the second through hole 71 when the non-connecting wire 11 passes through.

[0071] It should be noted that, in this article, relational terms such as first and second are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device comprising the elements.

[0072] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is intended only to illustrate the technical solution of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A low heat leakage vertical measurement dewar, characterized in that: include: An outer cylinder (1), an inner cylinder (2), a flange (3) and a cold shield (4); The inner cylinder (2) is coaxially arranged inside the outer cylinder (1), the inner cylinder (2) and the top of the outer cylinder (1) are connected via the flange (3), and the inner cylinder (2) is used to contain cryogenic liquid; The cold shield (4) is arranged between the inner cylinder (2) and the outer cylinder (1), and the top end of the cold shield (4) is sealedly connected to the outer wall of the inner cylinder (2) within a preset height range through a partition assembly (5); the preset height range is located between the flange (3) and the highest liquid level of the cryogenic liquid, and the temperature of the inner cylinder (2) at the connection position is greater than the temperature of the cold shield (4); The bottom end surface of the flange (3) is vertically connected to a plurality of suspension rods (6), the upper portion of the suspension rods (6) is provided with a multi-layer radiation baffle (7), the bottom end of the suspension rod (6) is connected to an object to be measured, and the object to be measured is immersed in the low-temperature liquid.

2. The vertical measurement dewar according to claim 1, characterized in that: The partition assembly (5) comprises: a support reinforcement ring (51), a copper plate (52) and a cold shield connecting ring (53); the cross sections of the support reinforcement ring (51) and the cold shield connecting ring (53) are both L-shaped; One end face of the cold screen connecting ring (53) is sealedly connected to the inner wall of the cold screen (4), and the copper plate (52) and one end face of the support reinforcement ring (51) are sequentially arranged on the other end face, and the end face of the cold screen connecting ring (53), the copper plate (52) and the end face of the support reinforcement ring (51) are fixedly connected by bolts (55); the other end face of the support reinforcement ring (51) is sealedly connected to the outer wall of the inner cylinder (2).

3. The vertical measurement dewar according to claim 2, characterized in that: The thickness of the copper plate (52) is not less than 5 mm.

4. The vertical measurement dewar according to claim 2, characterized in that: The partition assembly (5) further comprises a copper sheet (54) which is arranged between the copper plate (52) and the end surface of the cold shield connecting ring (53).

5. The vertical measurement dewar according to claim 4, characterized in that: The thickness of the copper sheet (54) is no more than 1 mm.

6. The vertical measurement dewar according to claim 2, characterized in that: The support reinforcement ring (51) and the copper plate (52) are riveted together at the non-bolt fastening portion by means of rivets (56).

7. The vertical measurement dewar according to claim 1, characterized in that: Each layer of the radiation shield (7) is provided with a plurality of first through holes, wherein the diameter of the first through holes is larger than the diameter of the suspension rod (6); Each radiation baffle (7) is sleeved on a suspension rod (6) through a corresponding first through hole, and each layer of radiation baffle (7) is separated by a polytetrafluoroethylene sleeve (8), and the polytetrafluoroethylene sleeve (8) at the bottom layer is locked on the corresponding suspension rod (6) through a locking ring (10).

8. The vertical measurement dewar according to claim 7, characterized in that: Aluminum foil tape (9) is provided on the radial edge of each layer of radiation baffle (7) so as to fill the gap between the radiation baffle (7) and the inner cylinder (2) with the aluminum foil tape (9).

9. The vertical measurement dewar according to claim 7, characterized in that: The radiation shield (7) is also provided with a plurality of second through holes (71) for the connection wires (11) to pass through.

10. The vertical measurement dewar according to claim 9, characterized in that: A circular disk (72) riveted with rivets (56) is provided around each of the second through holes (71), and the diameter of the circular disk (72) is larger than the diameter of the second through hole (71); The circular disc (72) can rotate around the rivet (56). When no connecting wire (11) passes through the second through hole (71), the circular disc (72) is rotated to cover the second through hole (71).

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