A superconducting cable non-welded sealing end and installation method

Abstract

The present invention discloses a superconducting cable solderless sealed end and an installation method, relating to the technical field of cables. The sealed end includes an outer pipe fastening sleeve, an inner pipe fastening sleeve is arranged inside the outer pipe fastening sleeve, a second pipe fitting for hermetically connecting an outer corrugated pipe and a first pipe fitting for connecting an inner corrugated pipe are respectively arranged inside the outer pipe fastening sleeve and the inner pipe fastening sleeve, a crimping end for integrally connecting a support body and a cable core body is arranged inside the inner pipe fastening sleeve, and a traction end for traction of the superconducting cable is connected to one side of the crimping end. Through the mutual cooperation among the outer pipe fastening sleeve and the inner pipe fastening sleeve provided by the present invention, the second pipe fitting of the outer corrugated pipe for hermetic connection, the first pipe fitting for connecting the inner corrugated pipe, the crimping end and the traction end arranged on one side of the crimping end, the outer and inner corrugated pipes, the overall cable core and the support body can be fixed respectively, and relative displacement is not likely to occur during traction, and the superconducting cable is not easily damaged.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and specifically to a superconducting cable non-welded sealed end and an installation method thereof. Background Art

[0002] Superconducting cables have many advantages such as low loss, high efficiency, large capacity, small floor space, and environmental friendliness, and are being competitively developed by various countries. They have great application advantages in future smart grids. Figure 1 As the basic structure of a superconducting cable, from the inside to the outside, a support body 91 and a hierarchical structure 92 (conductor layer, insulation layer, shielding layer, and protective layer) form the cable core of the superconducting cable. An inner corrugated pipe 93 is sleeved outside the cable core, and there is a certain space between the cable core and the inner corrugated pipe to ensure the flow of liquid nitrogen. An outer corrugated pipe 94 is sleeved outside the inner corrugated pipe 93, and there is still a certain space (vacuum interlayer) between the two to prevent heat leakage. A layer of PE sheath 95 is tightly extruded outside the outer corrugated pipe 94 to prevent the outer corrugated pipe from being corroded due to long-term exposure.

[0003] Currently, the common method for towing a superconducting cable is to make an arc-shaped cover with a towing hook or a closed-end sleeve at one end by imitating the towing head or waterproof towing head of an ordinary power cable, and only weld or flange-connect and seal it with the outer corrugated pipe. Towing the towing hook outside this arc-shaped cover or sleeve can achieve the coiling operation of the superconducting cable on the reel. The towing connection device invented in Patent 93N11021246091 "Towing Connection Device for Superconducting Cables" is a towing connection device invented according to the above method.

[0004] Since the structures of ordinary power cables and superconducting cables are completely different, there is a space between the cable core, inner corrugated pipe, and outer corrugated pipe of the superconducting cable, rather than a tight fit. Therefore, when towing the outer corrugated pipe alone, relative displacement will inevitably occur, resulting in external force damage to the cable, especially the cable core of the superconducting cable. Although it is an integral structure, since it is wound in multiple layers, relative displacement is also likely to occur between the support body, conductor layer, insulation layer, and shielding layer, and the forces are not synchronized. Once the conductor layer is subjected to a large force or bent, it is extremely easy to damage the superconducting cable. In addition, the insulation layer of the cable core is made of pplp material and is prone to moisture absorption, resulting in a significant reduction in insulation performance. The existing method is to weld and seal the towing end with the outer corrugated pipe, which is likely to cause the cable core of the superconducting cable to overheat or drop welding slag to ignite the insulation layer. When it is officially used, a relatively long section of the cable needs to be cut off, resulting in serious waste and high costs. Therefore, the present invention proposes a new type of superconducting cable non-welded sealed end and a usage method. Summary of the Invention

[0005] The purpose of the present invention is to provide a superconducting cable non-welded sealed end and an installation method thereof to solve the problems raised in the above background art.

[0006] To achieve the above object, the present invention provides the following technical solution: a superconducting cable non-welded sealing end head, the sealing end head includes an outer tube fastening sleeve, an inner tube fastening sleeve is arranged inside the outer tube fastening sleeve, and a second pipe fitting and a first pipe fitting for sealingly connecting an outer corrugated pipe and an inner corrugated pipe are respectively arranged inside the outer tube fastening sleeve and the inner tube fastening sleeve. A crimping end for connecting the support body and the cable core body as a whole is arranged inside the inner tube fastening sleeve, and a traction end for pulling the superconducting cable is connected to one side of the crimping end.

[0007] Preferably, an inner tube pressure cavity is formed between the crimping end and the inner tube fastening sleeve, and a vacuum pressure cavity is formed between the outer tube fastening sleeve and the inner tube fastening sleeve.

[0008] Preferably, the first pipe fitting and the second pipe fitting have the same structure. The first pipe fitting and the second pipe fitting both include sealing corrugations, and positioning convex heads are fixedly connected to the sealing corrugations.

[0009] Preferably, sealing installation parts adapted to the sealing corrugations and a plurality of positioning concave holes for fixing the positioning convex heads are formed on both the outer tube fastening sleeve and the inner tube fastening sleeve.

[0010] Preferably, the crimping end includes a first crimping part for connecting the support body. One end of the first crimping part is fixedly connected with a threaded head, and the other end is fixedly connected with a second crimping part for connecting the cable core body as a whole. The second crimping part is communicated with the first crimping part.

[0011] Preferably, a threaded groove adapted to the threaded head is formed on one side of the traction end, a traction hole is formed on the other side, and a spring is movably connected to the traction end.

[0012] Preferably, a pressure cavity air passage is formed on the traction end, and a first airtight valve is arranged at one end of the pressure cavity air passage for extracting gas from the inner tube pressure cavity or injecting gas into the inner tube pressure cavity.

[0013] Preferably, a vacuum cavity air hole is formed on the outer tube fastening sleeve, and a second airtight valve is arranged at one end of the vacuum cavity air hole for extracting gas from the vacuum pressure cavity or injecting gas into the vacuum pressure cavity.

[0014] Preferably, a third sealing track is formed inside the outer tube fastening sleeve, an inner tube sealing track is formed on the traction end, a second sealing track adapted to the third sealing track is formed inside the inner tube fastening sleeve, and a first sealing track adapted to the inner tube sealing track is formed inside the inner tube fastening sleeve.

[0015] A method for installing a sealing end head, which is used for installing a superconducting cable non-welded sealing end head, includes the following steps:

[0016] S1: Crimp the end of the support body and the first crimping part, and crimp the end of the entire cable core and the second crimping part;

[0017] S2: Screw the traction end and the crimping end together;

[0018] S3: Position and combine the first pipe fitting and the inner pipe fastening sleeve, pass the inner pipe fastening sleeve through the completed traction end and crimping end, and rotate the inner pipe fastening sleeve to tightly connect it with the inner corrugated pipe;

[0019] S4: Position and combine the outer pipe fastening sleeve of the second pipe fitting, pass the outer pipe fastening sleeve through the inner pipe fastening sleeve, and rotate the outer pipe fastening sleeve to tightly connect it with the outer corrugated pipe;

[0020] S5: Evacuate the gas in the inner pipe pressure chamber and the vacuum pressure chamber respectively through the first airtight valve and the second airtight valve, and choose whether to fill nitrogen after evacuating the air.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] For this superconducting cable's non-welded sealed end head, through the provided outer pipe fastening sleeve and inner pipe fastening sleeve, the second pipe fitting for sealing and connecting the outer corrugated pipe and the first pipe fitting for connecting the inner corrugated pipe, the crimping end, and the traction end arranged on one side of the crimping end cooperate with each other, which can respectively fix the inner and outer corrugated pipes, the entire cable core, and the support body. During traction, relative displacement is not likely to occur, the forces are not out of sync, the conductor layer is not likely to be overstressed or bent, the superconducting cable is not easily damaged, and the method of filling nitrogen in the inner pipe pressure chamber and the vacuum pressure chamber is adopted to reduce the possibility of the insulating layer getting damp, replacing the welding method. Therefore, the situation of the cable overheating during welding or the insulating layer being ignited by falling welding slag will not occur.

[0023] For this superconducting cable's non-welded sealed end head, through the first sealing track 43 and the inner pipe sealing track 25, the inner pipe fastening sleeve 4 can be tightly connected with the traction end 2, reducing the loss of liquid nitrogen filled into the inner pipe pressure chamber 7. The mutual cooperation between the second sealing track 44 and the third sealing track 63 makes the connection between the inner pipe fastening sleeve 4 and the outer pipe fastening sleeve 6 tighter, reducing the entry of external gas into the vacuum pressure chamber 8. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the superconducting cable of the present invention;

[0025] Figure 2 It is a three-dimensional split structural diagram of the sealed end head of the present invention;

[0026] Figure 3 It is a plane cross-sectional view of the sealed end head of the present invention;

[0027] Figure 4Cross-sectional view of the crimping end of the present invention;

[0028] Figure 5 Cross-sectional view of the traction end of the present invention;

[0029] Figure 6 Planar cross-sectional view of the first pipe fitting (or the second pipe fitting) of the present invention;

[0030] Figure 7 Cross-sectional view of the inner pipe fastening sleeve of the present invention;

[0031] Figure 8 Cross-sectional view of the outer pipe fastening sleeve of the present invention;

[0032] Figure 9 For the present invention Figure 8 Enlarged structural schematic diagram of part A in;

[0033] Figure 10 For the present invention Figure 3 Enlarged structural schematic diagram of part B in;

[0034] Figure 11 Planar cross-sectional view of the traction head of the prior art.

[0035] In the figure: 1. Crimping end; 11. Threaded head; 12. First crimping part; 13. Second crimping part; 2. Traction end; 21. Threaded groove; 22. Spring; 23. Pressure chamber air passage; 24. First airtight valve; 25. Inner pipe sealing track; 26. Traction hole; 3. First pipe fitting; 31. Sealing corrugation; 32. Positioning convex head; 4. Inner pipe fastening sleeve; 41. Sealing installation part; 42. Positioning concave hole; 43. First sealing track; 44. Second sealing track; 5. Second pipe fitting; 6. Outer pipe fastening sleeve; 63. Third sealing track; 64. Vacuum chamber air hole; 65. Second airtight valve; 7. Inner pipe pressure chamber; 8. Vacuum pressure chamber; 91. Support body; 92. Hierarchical structure; 93. Inner corrugated pipe; 94. Outer corrugated pipe; 95. PE sheath. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0037] It should be noted that in the description of the present invention, the orientation or positional relationships indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0038] In addition, it should be understood that for the convenience of description, the dimensions of the various components shown in the drawings are not drawn according to the actual proportional relationships. For example, the thickness or width of some layers may be exaggerated relative to other layers.

[0039] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined or described in one drawing, it will not be necessary to further specifically discuss and describe it in the description of the subsequent drawings.

[0040] As Figures 1-3 shown, the present invention provides a technical solution: a superconducting cable non-welded sealed end and an installation method. The sealed end includes an outer tube fastening sleeve 6. An inner tube fastening sleeve 4 is arranged inside the outer tube fastening sleeve 6. Second pipe fittings 5 and first pipe fittings 3 for sealing and connecting an outer corrugated pipe 94 and an inner corrugated pipe 93 are respectively arranged inside the outer tube fastening sleeve 6 and the inner tube fastening sleeve 4. A crimping end 1 for connecting the support body 91 and the cable core body as a whole is arranged inside the inner tube fastening sleeve 4. A traction end 2 for pulling the superconducting cable is connected to one side of the crimping end 1. It should be noted that an inner tube pressure chamber 7 is formed between the crimping end 1 and the inner tube fastening sleeve 4, and a vacuum pressure chamber 8 is formed between the outer tube fastening sleeve 6 and the inner tube fastening sleeve 4.

[0041] As Figure 6 shown, the first pipe fitting 3 and the second pipe fitting 5 have the same structure. Both the first pipe fitting 3 and the second pipe fitting 5 include a sealing corrugation 31, and positioning convex heads 32 are fixedly connected to the sealing corrugation 31. It should be noted that the sealing corrugation 31 formed on the first pipe fitting 3 is adapted to the inner corrugated pipe 93, and the sealing corrugation 31 formed on the second pipe fitting 5 is adapted to the outer corrugated pipe 94.

[0042] As Figure 7 shown, sealing installation parts 41 adapted to the sealing corrugation 31 and a plurality of positioning concave holes 42 for fixing the positioning convex heads 32 are formed on both the outer tube fastening sleeve 6 and the inner tube fastening sleeve 4. It should be noted that the function of the positioning convex heads 32 and the positioning concave holes 42 is to prevent the first pipe fitting 3 from rotating inside the inner tube fastening sleeve 4 and prevent the second pipe fitting 5 from rotating inside the outer tube fastening sleeve 6.

[0043] As Figure 4As shown in the figure, the crimping end 1 includes a first crimping portion 12 for connecting to the support body 91. One end of the first crimping portion 12 is fixedly connected to a threaded head 11, and the other end is fixedly connected to a second crimping portion 13 for connecting to the overall cable core. The second crimping portion 13 communicates with the first crimping portion 12. It should be noted that a hydraulic device is used to crimp the crimping end 1 to the end of the cable core and the support body 91.

[0044] As Figure 5 shown in the figure, one side of the traction end 2 is provided with a threaded groove 21 adapted to the threaded head 11, and the other side is provided with a traction hole 26. A spring 22 is movably connected to the traction end 2. It should be noted that the function of the spring 22 is to provide a buffering effect to prevent excessive pulling force from damaging the inner tube fastening sleeve 4.

[0045] As a specific embodiment, a pressure chamber air passage 23 is provided on the traction end 2. One end of the pressure chamber air passage 23 is provided with a first airtight valve 24 for extracting gas from or injecting gas into the inner tube pressure chamber 7.

[0046] As Figures 8-9 shown in the figure, a vacuum chamber air hole 64 is provided on the outer tube fastening sleeve 6. One end of the vacuum chamber air hole 64 is provided with a second airtight valve 65 for extracting gas from or injecting gas into the vacuum pressure chamber 8.

[0047] As Figure 3 and Figure 10 shown in the figure, a third sealing track 63 is provided inside the outer tube fastening sleeve 6, an inner tube sealing track 25 is provided on the traction end 2, a second sealing track 44 adapted to the third sealing track 63 is provided inside the inner tube fastening sleeve 4, and a first sealing track 43 adapted to the inner tube sealing track 25 is provided inside the inner tube fastening sleeve 4. It should be noted that the first sealing track 43 and the inner tube sealing track 25 can tightly connect the inner tube fastening sleeve 4 and the traction end 2, reducing the loss of liquid nitrogen filled into the inner tube pressure chamber 7. The mutual cooperation between the second sealing track 44 and the third sealing track 63 makes the connection between the inner tube fastening sleeve 4 and the outer tube fastening sleeve 6 tighter, reducing the entry of external gas into the vacuum pressure chamber 8. It should be noted that both the vacuum pressure chamber 8 and the inner tube pressure chamber 7 can be evacuated and pressurized according to actual needs.

[0048] A method for installing a sealing end head is as follows:

[0049] S1: Crimp the end of the support body 91 and the first crimping portion 12, and crimp the end of the overall cable core and the second crimping portion 13;

[0050] S2: Screw the traction end 2 onto the crimping end 1;

[0051] S3: Positionally combine the first pipe fitting 3 with the inner pipe fastening sleeve 4. Pass the inner pipe fastening sleeve 4 through the completed traction end 2 and the crimping end 1, and rotate the inner pipe fastening sleeve 4 to tightly connect it with the inner corrugated pipe 93.

[0052] S4: Positionally combine the outer pipe fastening sleeve 6 of the second pipe fitting 5. Pass the outer pipe fastening sleeve 6 through the inner pipe fastening sleeve 4, and rotate the outer pipe fastening sleeve 6 to tightly connect it with the outer corrugated pipe 94.

[0053] S5: Evacuate the gases in the inner pipe pressure chamber 7 and the vacuum pressure chamber 8 respectively through the first airtight valve 24 and the second airtight valve 65. After evacuating the air, choose whether to fill with nitrogen.

[0054] Specifically, first strip a certain length of the superconducting cable PE sheath 95, the outer corrugated pipe 94, the inner corrugated pipe 93, and the cable support 91 respectively, and then install the sealing end according to the above installation steps. It should be noted that the sealing corrugation 31 in the first pipe fitting 3 has the same wave pitch as the corrugation of the superconducting cable inner corrugated pipe 93, but the corrugation taper end is reduced by 2° compared to the inlet, and it can be tightly sleeved on the outer surface of the inner corrugated pipe 93 (the setting of the second pipe fitting 5 is the same as that of the first pipe fitting 3).

[0055] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A superconducting cable solderless sealed end, characterized in that: The sealed end includes an outer pipe fastening sleeve (6), an inner pipe fastening sleeve (4) is arranged inside the outer pipe fastening sleeve (6), a second pipe fitting (5) and a first pipe fitting (3) for sealing and connecting an outer corrugated pipe (94) and an inner corrugated pipe (93) are respectively arranged inside the outer pipe fastening sleeve (6) and the inner pipe fastening sleeve (4), a crimping end (1) for connecting the support body (91) and the cable core body as a whole is arranged inside the inner pipe fastening sleeve (4), and a traction end (2) for traction of the superconducting cable is connected to one side of the crimping end (1); An inner pipe pressure chamber (7) is formed between the crimping end (1) and the inner pipe fastening sleeve (4), and a vacuum pressure chamber (8) is formed between the outer pipe fastening sleeve (6) and the inner pipe fastening sleeve (4); The first pipe fitting (3) and the second pipe fitting (5) have the same structure. The first pipe fitting (3) and the second pipe fitting (5) both include a sealing corrugation (31), and positioning convex heads (32) are fixedly connected to the sealing corrugations (31); Sealing installation parts (41) adapted to the sealing corrugations (31) and a plurality of positioning concave holes (42) for fixing the positioning convex heads (32) are formed on both the outer pipe fastening sleeve (6) and the inner pipe fastening sleeve (4).

2. A superconducting cable non-welded sealing end according to claim 1, characterized in that: The crimping end (1) includes a first crimping part (12) for connecting the support body (91). A threaded head (11) is fixedly connected to one end of the first crimping part (12), and a second crimping part (13) for connecting the cable core body as a whole is fixedly connected to the other end. The second crimping part (13) communicates with the first crimping part (12).

3. A superconducting cable solderless sealed end according to claim 2, characterized in that: A threaded groove (21) adapted to the threaded head (11) is formed on one side of the traction end (2), a traction hole (26) is formed on the other side, and a spring (22) is movably connected to the traction end (2).

4. The superconducting cable non-welded sealed end according to claim 3, characterized in that: A pressure chamber air duct (23) is formed on the traction end (2). A first airtight valve (24) is arranged at one end of the pressure chamber air duct (23) for extracting gas from the inner pipe pressure chamber (7) or injecting gas into the inner pipe pressure chamber (7).

5. A superconducting cable solderless sealed end according to claim 4, characterized in that: A vacuum chamber air hole (64) is formed on the outer pipe fastening sleeve (6). A second airtight valve (65) is arranged at one end of the vacuum chamber air hole (64) for extracting gas from the vacuum pressure chamber (8) or injecting gas into the vacuum pressure chamber (8).

6. The superconducting cable solderless sealed end according to claim 5, characterized in that: A third sealing track (63) is formed inside the outer pipe fastening sleeve (6), an inner pipe sealing track (25) is formed on the traction end (2), a second sealing track (44) adapted to the third sealing track (63) is formed inside the inner pipe fastening sleeve (4), and a first sealing track (43) adapted to the inner pipe sealing track (25) is formed inside the inner pipe fastening sleeve (4).

7. A method for installing a sealed end, which is used to install the superconducting cable solderless sealed end described in claim 6, characterized in that: Including the following steps: S1: Crimp the end of the support body (91) and the first crimping part (12), and crimp the end of the cable core body as a whole and the second crimping part (13); S2: Screw the traction end (2) onto the crimping end (1); S3: Positionally combine the first pipe fitting (3) with the inner pipe fastening sleeve (4), pass the inner pipe fastening sleeve (4) through the completed traction end (2) and the crimping end (1), and rotate the inner pipe fastening sleeve (4) to tightly connect it with the inner corrugated pipe (93); S4: Positionally combine the second pipe fitting (5) with the outer pipe fastening sleeve (6), pass the outer pipe fastening sleeve (6) through the inner pipe fastening sleeve (4), and rotate the outer pipe fastening sleeve (6) to tightly connect it with the outer corrugated pipe (94); S5: Evacuate the gases in the inner pipe pressure chamber (7) and the vacuum pressure chamber (8) respectively through the first airtight valve (24) and the second airtight valve (65), and choose whether to fill with nitrogen after evacuating the air.

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