Dewar structure with temperature compensation for low-temperature superconducting equipment and low-temperature superconducting magnet

Abstract

The invention relates to the technical field of low-temperature superconducting equipment, and discloses a Dewar structure with temperature compensation for low-temperature superconducting equipment and a low-temperature superconducting magnet. The Dewar structure comprises an outer Dewar, an inner Dewar, a supporting rod, connecting lugs, connecting pressing blocks, a first connecting piece and a second connecting piece, the connecting lugs are arranged at the four corners of the inner Dewar and pressed through the connecting pressing blocks, and the connecting lugs and the connecting pressing blocks are fixed through cooperation of the first connecting piece and the second connecting piece arranged on the inner Dewar. The supporting rods penetrate through the connecting lugs at the four corners of the inner Dewar to fix the inner Dewar in the outer Dewar, and the connecting faces of the connecting lugs and the connecting pressing blocks are wedge-shaped faces. Therefore, the cold shrinkage stress generated by the large-size metal inner Dewar due to temperature reduction can be reduced. Moreover, after the temperature of the inner Dewar flask is stable, the connecting lugs and the inner Dewar flask can still keep a compressed state, and the inner Dewar flask can be stably fixed in the outer Dewar flask.

Description

Technical Field

[0001] The present invention relates to the technical field of low-temperature superconducting equipment, and in particular to a Dewar structure with temperature compensation and a low-temperature superconducting magnet of the low-temperature superconducting equipment. Background Art

[0002] Superconducting equipment uses superconducting wires wound into coils. When powered on, it interacts with the ground module to generate a huge magnetic field. In addition, the magnetic properties generated by superconducting magnets are stable, the spatially distributed magnetic field has a high uniformity, and the magnetic field of the required shape can be obtained. It is small in size and light in weight, so it is increasingly widely used. It has an important practical role and great application prospects in the fields of electrical engineering, transportation, medical treatment, military and science.

[0003] Superconducting coils require an extremely low temperature operating environment during operation, generally controlled in the 4K to 100K temperature range, to avoid the occurrence of quenching. Therefore, superconducting coils are usually loaded in a double-layer dewar structure, with the inner and outer dewars connected by a support structure. In addition, superconducting magnets will generate dynamic loads during operation, and the inner dewar needs to be stably fixed in the center position by a support structure to prevent vibration. Therefore, the inner dewar support structure of the superconducting magnet needs to have good structural stability to avoid the occurrence of quenching.

[0004] Prior art 1 proposes a temperature compensation support structure, in which the low-temperature Dewar is fixed in an external container by four sets of connecting bolts, and each set of bolts uses a plurality of butterfly gaskets as buffer elements to offset the shrinkage deformation caused by the temperature drop. This solution is simpler than the traditional Dewar container, is easy to install and disassemble, and can compensate for the deformation caused by temperature.

[0005] However, the temperature compensation of the cryogenic dewar structure of this scheme is mainly provided by the stroke of the butterfly gasket, and the amount of deformation that can be compensated is limited. After repeated use, the butterfly gasket needs to be inspected and replaced regularly. And because the butterfly gasket is an elastic element, the dewar cannot be stably fixed when subjected to vibration load.

[0006] Prior art 2 proposes a support device, in which the support structure mainly realizes temperature compensation through three sets of ball joint structures, and pull rods are respectively arranged in the X, Y, and Z directions, and the two ends of the pull rods are fixed by ball joints. This solution offsets the shrinkage deformation caused by the temperature drop through the rotation of the ball joint. Compared with the traditional support structure, this solution can convert the shear loads such as the circumferential shrinkage force and electromagnetic force of the magnet into axial tension and compression loads, thereby improving the reliability of the magnet structure.

[0007] However, this solution changes the loading method of the support component through a spherical hinge and cannot compensate for the displacement load generated during the cold shrinkage of the large-sized inner dewar. At the same time, due to the good rotational freedom of the spherical hinge, the inner dewar and the coil will also vibrate when the magnet moves. For a cryogenic superconducting magnet that bears dynamic loads and has a large size, the existing two forms of support structures and dewar structures cannot meet the usage requirements. Summary of the Invention

[0008] The present invention provides a dewar structure with temperature compensation for a cryogenic superconducting device and a cryogenic superconducting magnet, which can solve the technical problems in the prior art.

[0009] The present invention provides a dewar structure with temperature compensation for a cryogenic superconducting device. The dewar structure includes an outer dewar, an inner dewar, support rods, connecting lugs, connecting blocks, a first connecting member, and a second connecting member. The connecting lugs are arranged at the four corners of the inner dewar and are pressed tightly by the connecting blocks. The connecting lugs and the connecting blocks are fixed through the cooperation of the first connecting member and the second connecting member arranged on the inner dewar. The support rods pass through the connecting lugs at the four corners of the inner dewar to fix the inner dewar in the outer dewar. The connecting surface between the connecting lugs and the connecting blocks is a wedge surface.

[0010] Preferably, a clamping groove is arranged on the inner dewar, and the connecting lugs are arranged through the clamping groove.

[0011] Preferably, the first connecting member is a bolt, and the second connecting member is a nut, and the nut is welded on the inner dewar.

[0012] Preferably, the dewar structure further includes a gasket, which is arranged between the bolt and the nut.

[0013] Preferably, the gasket is a butterfly gasket.

[0014] Preferably, the connecting lugs and the connecting blocks are lubricated with grease.

[0015] Preferably, the materials of the outer dewar and the inner dewar are metals.

[0016] The present invention further provides a cryogenic superconducting magnet, which includes the above-mentioned dewar structure with temperature compensation for a cryogenic superconducting device.

[0017] Through the above technical solution, the inner dewar can be fixed in the outer dewar by using 4 support rods. The wedge structure is used for pressing at the connection between the connecting lugs and the inner dewar. When the inner dewar cools down and shrinks to generate displacement, it can slide through the wedge surface and finally be clamped in the wedge surface. Thus, the cold shrinkage stress generated due to the temperature reduction of the large-sized metal inner dewar can be reduced. Moreover, after the temperature of the inner dewar stabilizes, the connecting lugs and the inner dewar can still maintain a pressed state, and the inner dewar can be stably fixed in the outer dewar. In addition, the dewar structure has the advantage of simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings included herein are used to provide a further understanding of the embodiments of the present invention, which form a part of the specification, for illustrating the embodiments of the present invention, and for explaining the principles of the present invention together with the written description. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other drawings based on these drawings without creative efforts.

[0019] Figures 1A - 1D FIG. shows a schematic diagram of a Dewar structure with temperature compensation for a cryogenic superconducting device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0020] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and in no way serves as a limitation on the present invention and its application or use. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0021] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] Unless otherwise specifically stated, the relative arrangements, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific value should be interpreted as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters denote similar items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0023] FIG. 1 shows a schematic diagram of a Dewar structure with temperature compensation for a cryogenic superconducting device according to an embodiment of the present invention.

[0024] Among them, Figure 1A is the front view, Figure 1B is the partial enlarged view, Figure 1C is the partial cross-sectional view, Figure 1D is the orthographic isometric view.

[0025] As shown in FIG. 1, an embodiment of the present invention provides a Dewar structure with temperature compensation for a cryogenic superconducting device. Among them, the Dewar structure includes an outer Dewar 1, an inner Dewar 2, a support rod 3, a connecting ear piece 4, a connecting pressing block 5, a first connecting member 6, and a second connecting member 7. The connecting ear pieces 4 are arranged at the four corners of the inner Dewar 2 and are pressed tightly by the connecting pressing blocks 5. The connecting ear pieces 4 and the connecting pressing blocks 5 are fixed through the cooperation of the first connecting member 6 and the second connecting member 7 provided on the inner Dewar 2. The support rod 3 passes through the connecting ear pieces 4 at the four corners of the inner Dewar 2 to fix the inner Dewar 2 in the outer Dewar 1. The connecting surface between the connecting ear piece 4 and the connecting pressing block 5 is a wedge surface.

[0026] Through the above technical solution, the inner Dewar can be fixed in the outer Dewar by using 4 groups of support rods. A wedge structure is used for pressing at the connection between the connecting ear piece and the inner Dewar. When the temperature of the inner Dewar decreases and cold shrinkage displacement occurs, it can slide through the wedge surface and finally be clamped in the wedge surface. Thus, the cold shrinkage stress generated by the large-sized metal inner Dewar due to temperature reduction can be reduced. And, after the temperature of the inner Dewar stabilizes, the connecting ear piece and the inner Dewar can still maintain a pressed state, and the inner Dewar can be stably fixed in the outer Dewar. In addition, this Dewar structure has the advantage of simple structure.

[0027] According to an embodiment of the present invention, a card slot is provided on the inner Dewar 2, and the connecting ear piece 4 is arranged through the card slot.

[0028] By providing a card slot, it is convenient to position and install the connecting lug.

[0029] According to an embodiment of the present invention, the first connecting member 6 is a bolt, and the second connecting member 7 is a nut, and the nut is welded to the inner dewar 2.

[0030] According to an embodiment of the present invention, the dewar structure further includes a gasket 8 disposed between the bolt and the nut.

[0031] According to an embodiment of the present invention, the gasket 8 is a disc spring gasket.

[0032] The use of a disc spring gasket can buffer the vibration load generated in the transportation and working environments.

[0033] According to an embodiment of the present invention, the connecting lug 4 and the connecting block 5 are lubricated with grease.

[0034] According to an embodiment of the present invention, the materials of the outer dewar 1 and the inner dewar 2 are metals.

[0035] An embodiment of the present invention further provides a cryogenic superconducting magnet, which includes the temperature-compensated dewar structure of the cryogenic superconducting device described in the above embodiment.

[0036] The following describes the temperature-compensated dewar structure of the cryogenic superconducting device according to the present invention with reference to examples.

[0037] Continuing to refer to FIG. 1, the four corners of the inner dewar 2 are fixed in the outer dewar 1 by support rods 3. The support rods 3 pass through the connecting lugs 4. The connecting surface between the connecting lugs 4 and the connecting blocks 5 is a wedge surface and is fixed using two sets of bolts 6, nuts 7 and disc spring gaskets 8. The nut of the bolt 7 is welded to the inner dewar 2. A card slot is provided on the inner dewar 2 for positioning and installing the connecting lugs. After the lugs are positioned, two connecting blocks can be used to clamp each connecting lug, and there is a certain gap between the connecting block and the connecting lug. Finally, it is fixed using a disc spring gasket and a nut, and the disc spring gasket remains in the free height state. During the assembly process, the connecting lugs 4 and the connecting blocks 5 can be lubricated with grease to reduce the friction coefficient.

[0038] During the cooling process of the inner dewar, due to the cold shrinkage stress contracting towards the center of the structure, relative sliding occurs between the connecting lugs at the four corners and the connecting pressure blocks. When the temperature of the inner dewar reaches a steady state, the wedge-shaped structures of the connecting lugs and the connecting pressure blocks will be locked. This enables the cold shrinkage stress of the inner dewar to be released through the connecting structure (connecting lugs and connecting pressure blocks), and the cold shrinkage stress borne by the support rods is significantly reduced. The vibration loads generated during transportation and the working environment will be buffered by the disc spring washers. The stability of the magnet structure with the above-mentioned dewar structure is relatively high. The inner dewar is always stably fixed within the outer dewar. Moreover, since the cold shrinkage load of the inner dewar is released, the support member (support rod) can bear a greater load, which can further increase the operating load of the superconducting magnet.

[0039] As can be seen from the above embodiments, the dewar structure with temperature compensation of the cryogenic superconducting device described in the present invention has at least the following advantages compared with the prior art: the cold shrinkage load can be released through displacement, and the cold shrinkage stress borne by the support structure can be eliminated to a great extent. At the same time, after the temperature stabilizes, due to the limitation of the wedge-shaped structure, the support structure can fix the inner dewar well, and no additional vibration is generated during the movement of the magnet, meeting the requirements of magnet operation. In addition, the force transmission structure is simple, easy to install, and has high reliability, facilitating the application and operation in practice.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary instructions, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the protection scope of the present invention; the orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0041] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above" etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the figure of the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will be positioned as "below other devices or structures" or "under other devices or structures" afterwards. Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding explanations are made for the spatial relative descriptions used here.

[0042] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A Dewar structure with temperature compensation for a low-temperature superconducting device, characterized in that, The Dewar structure includes an outer Dewar (1), an inner Dewar (2), a support rod (3), a connecting lug (4), a connecting pressing block (5), a first connecting member (6) and a second connecting member (7). The connecting lugs (4) are arranged at the four corners of the inner Dewar (2) and are pressed tightly by the connecting pressing blocks (5). The connecting lugs (4) and the connecting pressing blocks (5) are fixed through the cooperation of the first connecting member (6) and the second connecting member (7) arranged on the inner Dewar (2). The support rod (3) passes through the connecting lugs (4) at the four corners of the inner Dewar (2) to fix the inner Dewar (2) in the outer Dewar (1). The connecting surface between the connecting lug (4) and the connecting pressing block (5) is a wedge surface.

2. The Dewar structure according to claim 1, wherein The inner Dewar (2) is provided with a card slot, and the connecting lug (4) is arranged through the card slot.

3. The Dewar structure according to claim 2, characterized in that, The first connecting member (6) is a bolt, and the second connecting member (7) is a nut, and the nut is welded on the inner Dewar (2).

4. The Dewar structure according to claim 1, wherein The Dewar structure further includes a gasket (8), which is arranged between the bolt and the nut.

5. The Dewar structure according to claim 4, characterized in that, The gasket (8) is a butterfly gasket.

6. The Dewar structure according to claim 4, wherein The connecting lug (4) and the connecting pressing block (5) are lubricated with grease.

7. The Dewar structure according to claim 6, characterized in that, The materials of the outer Dewar (1) and the inner Dewar (2) are metals.

8. A low-temperature superconducting magnet, characterized in that, A Dewar structure with temperature compensation including the cryogenic superconducting device according to any one of claims 1-7.

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