CN113077935B

CN113077935B - Superconducting cable refrigeration medium spiral transmission structure and superconducting cable

Info

Publication number: CN113077935B
Application number: CN202110316560.8A
Authority: CN
Inventors: 于是乎; 赵伟; 郑晓光; 杨翠茹; 何衍和; 魏俊涛
Original assignee: Electric Power Research Institute of Guangdong Power Grid Co Ltd
Current assignee: Electric Power Research Institute of Guangdong Power Grid Co Ltd
Priority date: 2021-03-23
Filing date: 2021-03-23
Publication date: 2022-05-20
Anticipated expiration: 2041-03-23
Also published as: CN113077935A

Abstract

The invention discloses a spiral transmission structure of a superconducting cable refrigeration medium and a superconducting cable, comprising: a refrigeration inner tube and a refrigeration outer tube; the diameter of the refrigerating inner pipe is smaller than that of the refrigerating outer pipe, the refrigerating inner pipe penetrates through the refrigerating outer pipe, and the superconducting tape is connected to the outer surface of the refrigerating inner pipe; the inner wall of the refrigeration inner pipe is provided with a first raised thread structure, the inner wall of the refrigeration outer pipe is provided with a second raised thread structure, and refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe are respectively spirally transmitted through the first thread structure and the second thread structure. The invention enables the refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe to be spirally transmitted through the raised thread structures arranged on the inner walls of the refrigeration inner pipe and the refrigeration outer pipe, thereby avoiding the problem of lower refrigeration effect caused by different temperatures of all parts of the refrigeration media.

Description

Superconducting cable refrigeration medium spiral transmission structure and superconducting cable

Technical Field

The invention relates to the technical field of superconducting cables, in particular to a spiral transmission structure of a refrigeration medium of a superconducting cable and the superconducting cable.

Background

Superconducting materials are materials that exhibit a resistance equal to zero and a property of repelling magnetic lines of force at a certain low temperature, which varies depending on the material, and are referred to as critical temperatures. The superconducting cable is designed and manufactured by utilizing the characteristics that a superconducting material becomes a superconducting state at the critical temperature, the resistance disappears, the loss is extremely low, the current density is high, and the superconducting cable can bear large current. The transmission capacity of the cable far exceeds that of an oil-filled cable and is also larger than that of a low-temperature cable, and the transmission capacity can reach more than 10000MVA, so that the cable is a novel cable which is being researched and developed vigorously. Since the critical temperature of superconductors is generally below 20K, superconducting cables typically operate in 4.2K of liquid helium.

As shown in fig. 1, patent document CN1530967A discloses a thermal insulation superconducting cable having a double-layer cooling passage structure and a cooling method thereof, which provides a cooling effect to upper and lower surfaces of a superconducting tape through the double-layer cooling passage structure, thereby ensuring that the inner superconducting tape operates below a critical temperature.

In order to avoid the superconducting cable quenching caused by the reduction of the refrigeration effect of the refrigeration medium, a plurality of refrigeration medium replacement supply stations are generally arranged along the superconducting cable, and the refrigeration medium passing through a certain transmission distance is recovered and a new refrigeration medium is input. The refrigeration medium in the cooling channel structure provided by the patent document is relatively stable in the transmission process, and the refrigeration effect of the upper layer and the lower layer of the refrigeration medium, which are in contact with the pipeline, can be gradually reduced under the heat exchange effect, so that the replacement and supply stations of the refrigeration medium needing to be arranged are relatively dense, and the cost is overhigh.

Disclosure of Invention

The purpose of the invention is: the spiral transmission structure of the refrigeration medium of the superconducting cable and the superconducting cable can solve the problems that the refrigeration structure and the winding mode of the superconducting cable still have insufficient refrigeration effect, a magnetic field coil is large, and the requirement on a joint structure is complex.

In order to achieve the above object, the present invention provides a spiral transmission structure of a refrigeration medium of a superconducting cable, comprising: a refrigeration inner tube and a refrigeration outer tube;

the diameter of the refrigerating inner pipe is smaller than that of the refrigerating outer pipe, the refrigerating inner pipe penetrates through the refrigerating outer pipe, and the outer surface of the refrigerating inner pipe is used for being connected with a superconducting tape;

the inner wall of the refrigeration inner pipe is provided with a first raised thread structure, the inner wall of the refrigeration outer pipe is provided with a second raised thread structure, and refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe are respectively spirally transmitted through the first thread structure and the second thread structure.

Further, the first thread structure and the second thread structure are a plurality of thread lines or a plurality of thread line segments arranged at intervals.

Further, the helix angle of the thread line or thread segment is: 60 to 80.

Further, the height of the thread line or thread segment is: 1mm to 3 mm.

Further, still include the insulating layer, the insulating layer sets up in the surface of refrigeration outer tube.

Further, the first thread formation and the second thread formation have opposite helical directions.

Further, the transmission directions of the refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe are different.

Further, the superconducting tape is spirally wound on the outer surface of the inner cooling pipe, and the spiral angle of the superconducting tape is the same as that of the second thread structure.

Further, the refrigeration medium includes liquid nitrogen and liquid helium.

The invention also provides a superconducting cable, which comprises the superconducting cable refrigeration medium spiral transmission structure in any embodiment.

Further, the direction of the spiral of the second thread structure is the same as the direction of the spiral of the superconducting tape.

Further, the width of the overlapping portion between the adjacent superconducting tapes is not more than 15% of the width of the superconducting tapes.

Compared with the prior art, the spiral transmission structure of the superconducting cable refrigeration medium and the superconducting cable thereof have the advantages that:

according to the invention, the spiral transmission of the refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe is realized through the raised thread structures arranged on the inner walls of the refrigeration inner pipe and the refrigeration outer pipe, so that the problem of low refrigeration effect caused by different temperatures of all parts of the refrigeration media is avoided, and the alternating current loss of the high-temperature superconducting cable can be reduced by winding the superconducting strips in an overlapping manner.

Drawings

FIG. 1 is a schematic view of the flow of a refrigerant medium through a prior art cooling channel structure;

FIG. 2 is a schematic diagram of a spiral transmission structure of a refrigerant according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view of a refrigeration inner tube according to one embodiment of the present invention;

fig. 4 is a cross-sectional view of a refrigeration outer tube in accordance with certain embodiments of the present invention;

FIG. 5 is a schematic view illustrating a winding method of a superconducting tape according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of a spiral transmission structure of a refrigerant according to an embodiment of the present invention;

fig. 7 is a schematic diagram of a spiral transmission structure of a refrigerant according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

As shown in fig. 2, the present embodiment provides a spiral transmission structure for a refrigeration medium of a superconducting cable, including: a refrigerating inner tube 1 and a refrigerating outer tube 2. The diameter of the refrigerating inner pipe 1 is smaller than that of the refrigerating outer pipe 2, the refrigerating inner pipe 1 penetrates through the refrigerating outer pipe 2, the superconducting tapes 3 are spirally wound on the outer surface of the refrigerating inner pipe 1, and the adjacent superconducting tapes are partially overlapped. In order to avoid loss of cooling capacity, the outer surface of the outer cooling pipe 2 is provided with a thermal insulation layer 4.

It should be noted that, in one embodiment of the present invention, the refrigeration medium includes, but is not limited to, liquid nitrogen and liquid helium, and the present invention is not limited thereto.

As shown in fig. 3 and 4, in one embodiment of the present invention, a first screw structure 11 protruding from the inner wall of the inner refrigeration pipe 1 is provided, a second screw structure 21 protruding from the inner wall of the outer refrigeration pipe 2 is provided, and the first screw structure 11 and the second screw structure 21 are used to screw the refrigeration mediums in the inner refrigeration pipe 1 and the outer refrigeration pipe 2, respectively.

The first thread structure 11 and the second thread structure 21 may be a plurality of thread lines or a plurality of spaced thread line segments, which is not limited by the present invention. Considering that the thread structure provides a certain resistance to the transport of the cooling medium, the present embodiment provides a helix angle of the thread or thread segment of 60 ° to 80 °, and a height of the thread or thread segment of 1mm to 3 mm.

Because two thread structures are adopted in the embodiment, if the spiral directions of the two thread structures are the same, the superconducting cable can be caused to displace under the spiral action of the cooling medium in the working process, so that the spiral directions of the first thread structure 11 and the second thread structure 21 are arranged in the embodiment to be opposite, the forces of the two spirals are mutually offset, slight vibration is generated at the same time, the cooling medium is fully cooled under the spiral and vibration actions, and the replacement and supply of the cooling medium along the line can be reduced.

The transmission directions of the refrigeration media in the refrigeration inner pipe 1 and the refrigeration outer pipe 2 can be the same or different, and the transmission directions are different in the embodiment, so that the convection is generated inside and outside, and the refrigeration effect is more sufficient.

As shown in fig. 5, the superconducting tapes 3 are spirally wound on the outer surface of the refrigerating inner tube 1 with an overlap portion between the adjacent superconducting tapes, and the width of the overlap portion is not more than 15% of the width of the superconducting tape. The spiral angle of the superconducting tape 3 is the same as that of the second thread structure, so that the impact effect of the medium flow on the superconducting tape 3 is reduced.

The superconducting tapes 3 are wound in an overlapping mode to reduce the alternating current loss of the high-temperature superconducting cable, and on the basis, the refrigerating inner pipe 1 can be made of a superconducting material to increase the current density.

In another embodiment of the present invention, as shown in fig. 6, a plurality of parallel inner refrigerant tubes 1 are disposed in an outer refrigerant tube 2 to realize, for example, three-phase current transmission.

In another embodiment of the present invention, as shown in fig. 7, a refrigerating inner pipe 2 is further provided inside a refrigerating inner pipe 2, and thus circulation is performed, for example, transmission of three-phase current is also possible.

Compared with the prior art, the spiral transmission structure of the superconducting cable refrigeration medium and the superconducting cable thereof provided by the invention have the following beneficial effects:

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A spiral transmission structure of a refrigeration medium of a superconducting cable is characterized by comprising: a refrigeration inner tube and a refrigeration outer tube;

the inner wall of the refrigeration inner pipe is provided with a first raised thread structure, the inner wall of the refrigeration outer pipe is provided with a second raised thread structure, refrigeration media in the refrigeration inner pipe and the refrigeration outer pipe are respectively spirally transmitted through the first thread structure and the second thread structure, and the spiral directions of the first thread structure and the second thread structure are opposite.

2. A spiral transmission structure for superconducting cable cooling medium according to claim 1, wherein the first and second thread structures are a plurality of thread lines or a plurality of thread line segments arranged at intervals.

3. A superconducting cable refrigeration medium spiral transmission structure according to claim 2, wherein a helix angle of the thread line or the thread line segment is 60 ° to 80 °.

4. A superconducting cable cooling medium spiral transmission structure according to claim 2, wherein the height of the thread line or the thread line segment is 1mm to 3 mm.

5. The spiral transmission structure of a superconducting cable cooling medium according to claim 1, further comprising a heat insulating layer provided on an outer surface of the cooling outer tube.

6. A spiral transmission structure of a superconducting cable cooling medium according to claim 1, wherein the cooling medium in the cooling inner tube and the cooling outer tube is transmitted in different directions.

7. A spiral transmission structure of a superconducting cable refrigerating medium according to claim 1, wherein the superconducting tape is spirally wound on an outer surface of the refrigerating inner pipe, and a spiral angle of the superconducting tape is the same as that of the second screw structure.

8. A superconducting cable cooling medium spiral transport structure according to claim 1, wherein the cooling medium includes liquid nitrogen and liquid helium.

9. A superconducting cable comprising the superconducting cable refrigeration medium spiral transmission structure of any one of claims 1 to 8.

10. The superconducting cable of claim 9, wherein a spiral direction of the second thread structure is the same as a spiral direction of the superconducting tape.

11. The superconducting cable of claim 9, wherein the width of the overlapping portion between adjacent superconducting tapes is not more than 15% of the width of the superconducting tapes.