Flexible fire resistant medium voltage power cable with corrugated armour

Abstract

The utility model provides a flexible fireproof medium voltage power cable with corrugated armor, including cable core and wrapping layer, armor layer and outer sheath, cable core framework includes "Y" shape's isolation framework and sets up in the wrapping layer of isolation framework end part's cladding framework, cladding framework structure is the elastic sheet material of deformable, when wrapping layer is wrapped in cladding framework and the outside of guide core, cladding framework deformation presents arc, and cladding is in the outside of guide core, through adopting the cable core framework design with "Y" shape isolation framework and the deformable "W" shape cladding framework, makes cladding framework smooth deformation and even cladding in the outside of guide core under the action of wrapping layer, forms stable support structure with filling layer, effectively avoided the risk that corrugated armor layer produced concentrated stress under external pressure and damaged cable core by puncturing inner liner, kept excellent radial flexibility, mechanical protection ability and electrical performance of cable, ensured power supply safety and long -term operation reliability.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to a flexible fireproof medium-voltage power cable with corrugated armor. Background Technology

[0002] Corrugated armored medium-voltage power cables are a critical type of medium-voltage power distribution line. Their most prominent feature is the use of corrugated aluminum or steel tape as the armor layer. This corrugated structure provides extremely high radial mechanical strength while giving the cable excellent flexibility, enabling it to effectively resist soil pressure, mechanical compression, and rodent bites during direct burial, and facilitating bending and laying in tunnels and ducts. The armor layer also serves as a good grounding wire and electromagnetic shielding layer; in particular, the non-magnetic aluminum armor avoids eddy current losses, ensuring the cable's current carrying capacity. Internally, the cable employs a phase-separated shielding structure, with each insulated core having an independent metallic shielding layer, effectively balancing the electric field and diverting fault currents to ensure power supply safety.

[0003] When the cable is subjected to external radial pressure, the raised parts of the rigid corrugated armor will generate significant inward stress. Although there is an inner lining layer between the cable core and the armor layer, its thickness is limited and its mechanical strength is insufficient. Under long-term or instantaneous heavy pressure, the crests of the corrugated armor are very likely to puncture or wear the inner lining layer and come into direct contact with the inner cable core. This may not only damage the insulation and shielding layers of the cable core and affect electrical performance, but also cause friction between the armor edge and the cable core when the cable is bent. Under long-term operation, this may lead to insulation breakdown and short-circuit faults. Utility Model Content

[0004] This utility model proposes a flexible fireproof medium-voltage power cable with corrugated armor, comprising:

[0005] Three sets of conductors are located on the outside of the cable core skeleton;

[0006] A filler layer is used to fill the space between the conductor core and the cable core skeleton;

[0007] The wrapping layer is wrapped around the outside of the cable core skeleton and the filler layer;

[0008] An armor layer, wrapped around the outside of the wrapping layer;

[0009] The outer sheath is extruded onto the outside of the armor layer;

[0010] The cable core skeleton includes a "Y"-shaped isolation skeleton and a covering skeleton disposed at the end of the isolation skeleton. The covering skeleton is constructed as a deformable elastic sheet. Before deformation, the distance between two adjacent covering skeletons is greater than or equal to the conductor wire diameter. After the wrapping layer is wrapped around the outside of the covering skeleton and the conductor, the covering skeleton deforms into an arc shape and wraps around the outside of the conductor.

[0011] Preferably, the covering skeleton includes a recess at the connection with the isolation skeleton and protrusions at both ends of the recess. The recess and protrusions are constructed in a "W" shape, and when the covering skeleton is deformed by the wrapping layer, the recess and protrusions form an arc shape.

[0012] Preferably, the "Y"-shaped isolation frame includes three isolation strips distributed symmetrically in a central manner.

[0013] Preferably, the cable core skeleton comprises a polyethylene or polypropylene skeleton.

[0014] Preferably, the filling layer includes a filling strip pre-bonded to the inner side of the cable core skeleton, the filling strip including a plastic foam filling strip.

[0015] Preferably, the filler strip is disposed on the inner side of the isolation skeleton and the covering skeleton, and forms a guide core cavity for mounting the guide core.

[0016] Preferably, the conductor core includes multiple stranded wires and a three-layer co-extruded insulation layer covering the outside of the wires, with a shielding layer wrapped around the outside of the insulation layer.

[0017] Preferably, the wrapping layer is formed by wrapping with non-woven fabric tape or polyester tape.

[0018] Preferably, the armor layer comprises corrugated aluminum strip or corrugated steel strip.

[0019] Preferably, the outer sheath comprises a polyvinyl chloride or polyethylene sheath.

[0020] Compared with the prior art, the advantages of this utility model are:

[0021] This invention employs a cable core skeleton design with a "Y"-shaped isolation skeleton and a deformable "W"-shaped covering skeleton. Under the action of the wrapping layer, the covering skeleton deforms smoothly and evenly covers the outside of the conductor core, forming a stable support structure together with the filling layer. This effectively avoids the risk of the corrugated armor layer puncturing the inner lining and damaging the cable core due to concentrated stress generated under external pressure. At the same time, it maintains the cable's excellent radial flexibility, mechanical protection capability, and electrical performance, ensuring power supply safety and long-term operational reliability. Attached Figure Description

[0022] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0023] Figure 1 This is a schematic diagram of the hierarchical structure of a flexible fireproof medium-voltage power cable with corrugated armor, as shown in an embodiment of this utility model.

[0024] Figure 2 This is a schematic diagram of the cross-sectional structure of a flexible fireproof medium-voltage power cable with corrugated armor, as shown in an embodiment of this utility model.

[0025] Figure 3 This is a schematic cross-sectional view of the initial state of the cable core skeleton shown in the embodiment of this utility model;

[0026] Figure 4 This is a schematic diagram of the cross-sectional structure of the cable core skeleton after wrapping and extrusion according to an embodiment of this utility model;

[0027] 10. Conductor core; 20. Cable core skeleton; 200. Conductor core cavity; 21. Isolation skeleton; 22. Covering skeleton; 221. Recess; 222. Protrusion; 30. Filler layer; 31. Filler strip; 40. Wrapping layer; 50. Armor layer; 60. Outer sheath. Detailed Implementation

[0028] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0029] like Figures 1 to 4 As shown, this utility model provides a flexible fireproof medium-voltage power cable with corrugated armor, which aims to solve the problem that corrugated armor may puncture the internal cable core, while maintaining the cable's excellent flexibility and mechanical protection performance. The cable mainly includes a cable core and layers of wrapping layer 40, armor layer 50 and outer sheath 60 arranged on the outside of the cable core.

[0030] Among them, three sets of conductor cores 10 are centrally symmetrically distributed and set on the outside of the cable core skeleton 20. The cable core skeleton 20 is used to separate the conductor cores 10 and support the entire cable core. The filling layer 30 is filled between the conductor cores 10 and the cable core skeleton 20, and the filling layer 30 keeps the cable cross-section round.

[0031] The wrapping layer 40 is wrapped around the outside of the cable core skeleton 20 and the filler layer 30. The wrapping layer 40 is formed by wrapping with non-woven fabric tape or polyester tape. The armor layer 50 is wrapped around the outside of the wrapping layer 40 and mainly provides mechanical protection. The outer sheath 60 is extruded around the outside of the armor layer 50 and mainly provides weather resistance and corrosion protection.

[0032] Furthermore, the cable core skeleton 20 includes a "Y"-shaped isolation skeleton 21 and a covering skeleton 22 disposed at the end of the isolation skeleton 21. The "Y"-shaped isolation skeleton 21 includes three isolation strips distributed in a centrally symmetrical manner. The cable core skeleton 20 can be made of polyethylene or polypropylene skeleton to provide stable support for the cable core.

[0033] Preferably, the covering skeleton 22 is constructed as a deformable elastic sheet, and the distance between two adjacent covering skeletons 22 before deformation is greater than or equal to the wire diameter of the guide core 10, so that a guide core cavity 200 for mounting the guide core 10 is formed on the inner side of the covering skeleton 22.

[0034] Thus, in an unconstrained state, the spacing between two adjacent sheets of the deformable elastic sheet is greater than or equal to the diameter of the cable core, so as to facilitate the insertion of the cable core.

[0035] In a specific embodiment, the covering skeleton 22 includes a recess 221 at the connection with the isolation skeleton 21 and a protrusion 222 at both ends of the recess 221. The recess 221 and the protrusion 222 are constructed in a "W" shape. When the covering skeleton 22 is deformed by the wrapping layer 40, the recess 221 and the protrusion 222 form an arc shape. In the natural state, the recess 221 and the protrusion 222 together form a "W" shape, which makes the elastic sheet material have better elastic deformation ability.

[0036] like Figure 3 and Figure 4 As shown, when the cladding layer 40 wraps around the outer side of the cladding frame 22 and the conductor core 10, the cladding frame 22 deforms into an arc shape and wraps around the outer side of the conductor core 10. When subjected to pressure deformation after the cladding layer 40 wraps around the cladding frame 22, the entire sheet smoothly transitions into an arc shape, adhering to the outer surface of the cable core and providing uniform support.

[0037] Furthermore, the filler layer 30 includes a filler strip 31 pre-bonded and fixed to the inside of the cable core skeleton 20. The filler strip 31 includes a plastic foam filler strip. The filler strip 31 is disposed inside the isolation skeleton 21 and the covering skeleton 22. The filler strip 31 is disposed inside the “Y”-shaped isolation skeleton 21 and the covering skeleton 22, together forming a stable space for the installation of the conductor core 10, ensuring that the three conductor cores 10 maintain a precise symmetrical position inside the cable.

[0038] The conductor core 10 includes multiple stranded wires and three co-extruded insulation layers covering the outside of the wires. It can effectively balance the electric field distribution, prevent partial discharge, and ensure the long-term stability and high electrical strength of the insulation system. A shielding layer is wrapped around the outside of the insulation layer. The metal shielding layer wrapped around the outside of the insulation layer forms a complete capacitive current channel and can quickly conduct fault current to ensure power supply safety.

[0039] In an optional embodiment, the armor layer 50 includes a corrugated aluminum tape or a corrugated steel tape, the corrugated structure of which provides high-strength mechanical protection against external crushing, impact and rodent bites, while giving the cable the necessary radial flexibility to facilitate laying and installation.

[0040] In an optional embodiment, the outer sheath 60 includes a polyvinyl chloride or polyethylene sheath formed by extrusion of polyvinyl chloride or polyethylene material, which can provide continuous, sealed protection for the internal armor layer 50 and cable core structure, and give the cable excellent weather resistance.

[0041] In conjunction with the above embodiments, by adopting a cable core skeleton 20 design with a "Y"-shaped isolation skeleton 21 and a deformable "W"-shaped covering skeleton 22, the covering skeleton 22 is smoothly deformed and evenly covered on the outside of the conductor core 10 under the action of the wrapping layer 40. Together with the filling layer 30, it forms a stable support structure, effectively avoiding the risk of the corrugated armor layer 50 puncturing the inner liner and damaging the cable core due to concentrated stress generated under external pressure. At the same time, it maintains the cable's excellent radial flexibility, mechanical protection capability and electrical performance, ensuring power supply safety and long-term operational reliability.

[0042] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A flexible fire-resistant medium-voltage power cable with corrugated armor, characterized in that, include: Three sets of conductor cores (10) are set on the outside of the cable core skeleton (20); A filler layer (30) is filled between the conductor (10) and the cable core skeleton (20); The wrapping layer (40) wraps around the outside of the cable core skeleton (20) and the filling layer (30); An armor layer (50) is wrapped around the outside of the wrapping layer (40); The outer sheath (60) is extruded onto the outside of the armor layer (50); The cable core skeleton (20) includes a "Y"-shaped isolation skeleton (21) and a covering skeleton (22) disposed at the end of the isolation skeleton (21). The covering skeleton (22) is constructed as a deformable elastic sheet. Before deformation, the distance between two adjacent covering skeletons (22) is greater than or equal to the wire diameter of the conductor (10). When the wrapping layer (40) wraps around the outside of the covering skeleton (22) and the conductor (10), the covering skeleton (22) deforms into an arc shape and wraps around the outside of the conductor (10).

2. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The covering skeleton (22) includes a recess (221) at the connection with the isolation skeleton (21) and a protrusion (222) at both ends of the recess (221). The recess (221) and the protrusion (222) are constructed in a "W" shape, and when the covering skeleton (22) is deformed by the wrapping layer (40), the recess (221) and the protrusion (222) form an arc shape.

3. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The "Y"-shaped isolation frame (21) includes three isolation strips that are centrally symmetrically distributed.

4. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The cable core skeleton (20) includes a polyethylene or polypropylene skeleton.

5. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The filling layer (30) includes a filling strip (31) pre-bonded to the inside of the cable core skeleton (20), and the filling strip (31) includes a plastic foam filling strip.

6. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 5, characterized in that, The filler strip (31) is disposed on the inner side of the isolation skeleton (21) and the covering skeleton (22), and forms a guide core cavity (200) for mounting the guide core (10).

7. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The conductor core (10) includes multiple stranded wires and three co-extruded insulation layers covering the outside of the wires, with a shielding layer wrapped around the outside of the insulation layers.

8. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The wrapping layer (40) is formed by wrapping with non-woven fabric tape or polyester tape.

9. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The armor layer (50) comprises corrugated aluminum strip or corrugated steel strip.

10. The flexible fire-resistant medium-voltage power cable with corrugated armor according to claim 1, characterized in that, The outer sheath (60) includes a polyvinyl chloride or polyethylene sheath.

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