Traction head for laying high-temperature superconducting cables

Abstract

The present invention discloses a traction head for laying high-temperature superconducting cables, wherein the high-temperature superconducting cable comprises a vacuum insulation layer and an insulating core, and a gap is provided between the inner tube of the vacuum insulation layer and the insulating core for maintaining the circulation of liquid nitrogen; the traction head comprises an outer sleeve, a pull ring and a tension spring; one end of the outer sleeve is connected to the vacuum insulation layer, and the other end is connected to the pull ring; the tension spring is arranged in the outer sleeve, one end is relatively fixed to the outer sleeve, and the other end is connected to the lining core of the insulating core. The present invention can well reduce the relative movement between the insulating core and the metal sleeve of the high-temperature superconducting cable, and solve the defect that the metal sleeve and the insulating core cannot be pulled synchronously during laying due to the gap between the metal sleeve and the insulating core.

Description

Technical Field

[0001] The invention relates to the technical field of superconducting cable laying, in particular to a traction head used for high-temperature superconducting cable laying. Background Art

[0002] High-temperature superconducting cable is a power cable that uses superconducting materials that experience resistance loss at ultra-low temperatures, i.e., superconducting state, as conductors. Its normal operating temperature is the liquid nitrogen temperature range (77K).

[0003] Since superconducting cables differ from conventional cables not only in insulation materials and conductors, but also because they operate at low temperatures, namely liquid nitrogen temperatures, the cables must have a vacuum insulation layer structure, which is usually composed of a metal sheath formed by a steel wire braid and a metal bellows, and a vacuum between the metal sheath and the insulating core to maintain a low-temperature environment for the insulating core.

[0004] There must be a certain gap between the inner tube of the vacuum insulation layer and the insulated core of the cable to maintain the circulation of liquid nitrogen, so that the insulated core and the metal sleeve can slide.

[0005] The special structure of the high-temperature superconducting cable results in that when the traction head pulls the insulated core alone, the insulated core will move while the metal sheath and the outer sheath do not move accordingly. When the mesh sheath is used to pull the outer sheath alone, the metal sheath and the outer sheath of the cable will move while the insulated core of the cable will not move accordingly, which brings many inconveniences to the laying of high-temperature superconducting cables.

[0006] Therefore, how to solve the defect that the metal sheath and the insulating core cannot be pulled synchronously during laying due to the gap has become a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0007] In view of the above-mentioned defects of the prior art, the present invention provides a traction head for laying high-temperature superconducting cables, the purpose of which is to solve the defect that synchronous traction cannot be performed during laying due to the gap between the metal sheath and the insulating core.

[0008] To achieve the above object, the present invention discloses a traction head for laying a high-temperature superconducting cable, wherein the high-temperature superconducting cable comprises a vacuum insulation layer and an insulating core, and a gap for maintaining liquid nitrogen circulation is provided between an inner tube of the vacuum insulation layer and the insulating core; the traction head comprises an outer sleeve, a pull ring and a tension spring;

[0009] One end of the outer sleeve is connected to the vacuum insulation layer, and the other end is connected to the pull ring;

[0010] The tension spring is arranged in the outer sleeve, one end of which is relatively fixed to the outer sleeve, and the other end of which is connected to the liner of the insulating core.

[0011] Preferably, a traction head flange is provided at one end of the outer sleeve connected to the pull ring; the traction head flange is fixedly connected to the outer sleeve, the pull ring and the tension spring.

[0012] More preferably, a threaded connecting rod is provided between the traction head flange and the tension spring; one end of the threaded connecting rod is fixed to the traction head flange, and the other end is fixed to the tension spring.

[0013] More preferably, one end of the threaded connecting rod passes through the inner hole of the traction head flange to pass through the end of the vacuum insulation layer to be towed, and is constrained to the traction head flange by setting a nut.

[0014] Preferably, the tension spring is connected to the liner core via a metal crimping tube and a connecting ring;

[0015] One end of the metal crimping tube is fixed to the liner core, and the other end is fixedly connected to the tension spring via the connecting ring.

[0016] Preferably, the vacuum insulation layer is a double-layer structure, including an outer steel wire braided layer and an inner metal bellows;

[0017] The vacuum insulation layer is also covered with an outer protective layer.

[0018] More preferably, two cable end flanges are provided between the outer sleeve and the vacuum insulation layer;

[0019] One of the cable end flanges is fixed to the metal bellows and the steel wire braided layer of the high-temperature superconducting cable by welding; the other cable end flange is connected to the outer sleeve;

[0020] A rubber gasket is arranged between the two cable end flanges and is fastened with bolts.

[0021] Preferably, the structure of the outer sleeve is the same as the corresponding part of the high-temperature superconducting cable.

[0022] Beneficial effects of the present invention:

[0023] The present invention can well reduce the relative movement between the insulating core and the metal sheath of the high-temperature superconducting cable, and solve the defect that the metal sheath and the insulating core cannot be pulled synchronously during laying due to the gap between them.

[0024] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1A schematic structural diagram of an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0026] Example

[0027] like Figure 1 As shown, a traction head for laying a high-temperature superconducting cable, the high-temperature superconducting cable comprises a vacuum insulation layer and an insulating core 1, and a gap for maintaining liquid nitrogen circulation is provided between the inner tube of the vacuum insulation layer and the insulating core 1; the traction head comprises an outer sleeve 15, a pull ring 2 and a tension spring 3;

[0028] One end of the outer sleeve 15 is connected to the vacuum insulation layer, and the other end is connected to the pull ring 2;

[0029] The tension spring 3 is arranged in the outer sleeve 15 , one end of which is relatively fixed to the outer sleeve 15 , and the other end of which is connected to the liner 4 of the insulating core 1 .

[0030] The principle of the present invention is as follows:

[0031] The tension spring 3 should be selected according to Hooke's law in combination with the tension during the cable laying process and the acceptable displacement, including the wire diameter, length and outer diameter. When the relative displacement between the vacuum insulation layer and the insulating core 1 becomes larger, the tension spring 3 is stretched, the tension of the tension spring 3 increases, and part of the tension on the vacuum insulation layer is transferred to the insulating core 1. As the displacement between the vacuum insulation layer and the insulating core 1 increases, the tension on the tension spring 3 increases. According to Hooke's law, before the tension spring 3 fails, the greater the deformation, the greater the tension, and the greater the proportion of the insulation core 1 sharing.

[0032] Through the above structure, the tension applied to the tension spring 3 is borne by the insulating core 1, so the relative movement between the vacuum insulation layer and the insulating core 1 can be well reduced.

[0033] In some embodiments, preferably, a traction head flange 5 is provided at one end of the outer sleeve 15 connected to the pull ring 2 ; the traction head flange 5 is fixedly connected to the outer sleeve 15 , the pull ring 2 and the tension spring 3 .

[0034] In some embodiments, a threaded connecting rod 7 is provided between the traction head flange 5 and the tension spring 3 ; one end of the threaded connecting rod 7 is fixed to the traction head flange 5 , and the other end is fixed to the tension spring 3 .

[0035] In some embodiments, one end of the threaded connecting rod 7 passes through the inner hole of the traction head flange 5 at the end of the vacuum insulation layer to be towed, and is constrained to the traction head flange 5 by setting a nut 8.

[0036] In some embodiments, the tension spring 3 and the liner core 4 are connected via a metal crimping tube 9 and a connecting ring 10;

[0037] One end of the metal crimping tube 9 is fixed to the liner core 4 , and the other end is fixedly connected to the tension spring 3 via a connecting ring 10 .

[0038] In some embodiments, the vacuum insulation layer is a double-layer structure, including an outer steel wire braided layer 11 and an inner metal bellows 12;

[0039] The vacuum insulation layer is also covered with an outer protective layer 6.

[0040] In some embodiments, two cable end flanges 13 are provided between the outer sleeve 15 and the vacuum insulation layer;

[0041] One cable end flange 13 is fixed to the metal bellows 12 and the steel wire braided layer 11 of the high-temperature superconducting cable by welding; the other cable end flange 13 is connected to the outer sleeve 15;

[0042] A rubber gasket is provided between the two cable end flanges 13 and is fastened with bolts 14 .

[0043] Considering the complicated manufacturing process of superconducting cables, the traction device is installed by the cable manufacturer before leaving the factory, and the cables are subjected to external forces during transportation. In some embodiments, the structure of the outer sleeve 15 is the same as the corresponding part of the high-temperature superconducting cable.

[0044] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A traction head for laying a high-temperature superconducting cable, wherein the high-temperature superconducting cable comprises a vacuum insulation layer and an insulating core (1), and a gap for maintaining liquid nitrogen circulation is provided between an inner tube of the vacuum insulation layer and the insulating core (1); characterized in that: The traction head comprises an outer sleeve (15), a pull ring (2) and a tension spring (3); One end of the outer sleeve (15) is connected to the vacuum insulation layer, and the other end is connected to the pull ring (2); The tension spring (3) is arranged in the outer sleeve (15), one end of which is relatively fixed to the outer sleeve (15), and the other end of which is connected to the liner (4) of the insulating wire core (1); The vacuum insulation layer is a double-layer structure, comprising an outer steel wire braided layer (11) and an inner metal bellows (12); The vacuum insulation layer is also covered with an outer protective layer (6); Two cable end flanges (13) are provided between the outer sleeve (15) and the vacuum insulation layer; One of the cable end flanges (13) is fixed to the metal corrugated tube (12) and the steel wire braided layer (11) of the high-temperature superconducting cable by welding; and another of the cable end flanges (13) is connected to the outer sleeve (15); A rubber gasket is provided between the two cable end flanges (13) and is fastened with bolts (14); A traction head flange (5) is provided at one end of the outer sleeve (15) connected to the pull ring (2); the traction head flange (5) is fixedly connected to the outer sleeve (15), the pull ring (2) and the tension spring (3); The tension spring (3) is connected to the liner core (4) via a metal crimping tube (9) and a connecting ring (10); one end of the metal crimping tube (9) is fixed to the liner core (4), and the other end is fixedly connected to the tension spring (3) via the connecting ring (10).

2. The traction head for laying high-temperature superconducting cables according to claim 1, characterized in that: A threaded connecting rod (7) is provided between the traction head flange (5) and the tension spring (3); one end of the threaded connecting rod (7) is fixed to the traction head flange (5), and the other end is fixed to the tension spring (3).

3. The traction head for laying high-temperature superconducting cables according to claim 2, characterized in that: One end of the threaded connecting rod (7) passes through the inner hole of the traction head flange (5) to pass through the end of the vacuum insulation layer to be towed, and is constrained by the traction head flange (5) by providing a nut (8).

4. The traction head for laying high-temperature superconducting cables according to claim 1, characterized in that: The structure of the outer sleeve (15) is the same as the corresponding part of the high-temperature superconducting cable.

Images