Distortion-resistant flame-retardant medium-voltage power cable

Abstract

The utility model discloses an anti-distortion flame-retardant medium-voltage power cable, which comprises a cable core, the cable core comprises a filling layer and a wire core, the cable core is internally provided with support frames, the support frames are equidistantly arranged along the wire core, the cable core is externally provided with a mica wrapping layer, the mica wrapping layer is externally provided with an inner lining layer, and the inner lining layer is internally provided with a flame-retardant layer. The medium-voltage power cable is characterized in that a lining layer is arranged outside the cable core, a composite flame-retardant layer is arranged outside the lining layer, an elastic layer is arranged outside the composite flame-retardant layer, an armor layer is arranged outside the elastic layer, an outer sheath is arranged outside the armor layer, and the outer sheath and the armor layer are formed through extrusion. The structure strength of the cable core can be increased, the cable core is prevented from being twisted together when being subjected to external force, the elasticity of the cable is increased by the elastic layer, the cable core is better protected when the power cable is twisted, the cable core is prevented from being damaged due to cable twisting, and the service life of the power cable is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of power cables, in particular to a twist-resistant flame-retardant medium-voltage power cable. Background Art

[0002] A cable is a conductor made of one or more mutually insulated conductors and an outer insulating protective layer. It is laid underground, in the air, etc. Cables generally consist of three parts: a conductor, an insulating layer, and a protective layer. There are usually two types of cables: power cables and control cables. Power cables are mainly used for the transmission and distribution of electric energy; control cables are mainly used for measurement, protection, and control lines. Power cables are cable products used to transmit and distribute high-power electric energy in the trunk lines of power systems. They include power cables with various voltage levels and various insulation levels from 1 to 500 kV and above. The basic structure of power cables consists of four parts: a core, an insulating layer, a shielding layer, and a protective layer. They are commonly used in urban underground power grids, power station lead-out lines, internal power supplies for industrial and mining enterprises, and underwater transmission lines across rivers and seas.

[0003] The Chinese patent publication number is CN208422489U, and the authorization announcement date is January 22, 2019. It is a twist-resistant cable, including multiple cable cores and a packaging tape layer wrapped around the multiple cable cores, the outer side of the packaging tape layer is wrapped with a steel tape layer, and the outer side of the steel tape layer is wrapped with a sheath layer; each cable core is wrapped with an insulation layer; multiple cable cores are twisted to form a cable main core, and the gap between the cable main core and the packaging tape layer is filled with silicone; multiple plastic strips are provided in the packaging tape layer; multiple plastic bird-proof sheaths are provided on the outer side of the sheath layer, and the bird-proof sheaths are sleeve-shaped and sleeved on the sheath layer. The sheath layer is provided with an annular slide corresponding to each bird-proof sheath, and the bird-proof sheaths can be rotatably placed in the annular slide groove. The cable main core of the utility model has a small twisting amplitude, which reduces damage to the cable main core; after twisting, it quickly rebounds in the absence of external force and returns to its original state, reducing damage to the cable main core caused by twisting; it prevents birds from damaging the cable, and the device has a simple structure and a long service life.

[0004] Existing power cables have insufficient resistance to twisting and tensile stress. External forces acting on the cables often act vertically, causing excessive concentration of forces on the internal conductors. This may cause the metal conductors in the cable core to twist and deform. Long-term exposure to twisting and stretching will shorten the service life of the cable and make it unable to meet usage requirements. Utility Model Content

[0005] The purpose of the utility model is to provide a torsion-resistant flame-retardant medium-voltage power cable to solve the problem raised in the above background technology that the torsion resistance and tensile strength of the existing power cables are insufficient, the external forces acting on the cables are mostly vertical, the forces acting on the internal wires are too concentrated, and the metal conductors in the cable core may be twisted and deformed. Long-term torsion and stretching will shorten the service life of the cable and cannot meet the use requirements.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a torsion-resistant flame-retardant medium-voltage power cable, comprising a cable core, the cable core comprising a filling layer and a wire core, a support frame being arranged inside the cable core, and the support frame being arranged in a cross shape, the support frame being arranged equidistantly along the wire core, a mica sheath being arranged outside the mica sheath, an inner lining being arranged outside the mica sheath, and the inner lining being bonded to the mica sheath, a composite flame-retardant layer being arranged outside the inner lining, and the composite flame-retardant layer being bonded to the inner lining, an elastic layer being arranged outside the composite flame-retardant layer, and the elastic layer being bonded to the composite flame-retardant layer, an armor layer being arranged outside the elastic layer, and the armor layer being bonded to the elastic layer, an outer sheath being arranged outside the armor layer, and the outer sheath and the armor layer being bonded to the elastic layer.

[0007] Preferably, the wire core includes a conductor, an inner insulation layer, a shielding layer and an outer insulation layer, and the conductor is formed by twisting multiple metal wires, the inner insulation layer is arranged on the outside of the conductor, the shielding layer is arranged on the outside of the inner insulation layer, and the outer insulation layer is arranged on the outside of the shielding layer, and the inner insulation layer, the shielding layer and the outer insulation layer are extruded in sequence on the outside of the conductor.

[0008] Preferably, the composite flame retardant layer includes a first flame retardant layer and a second flame retardant layer, and the second flame retardant layer is arranged outside the first flame retardant layer.

[0009] Preferably, the outer sheath is provided with reinforcing ribs, six of which are provided and integrated with the outer sheath, and the six reinforcing ribs are equidistantly arranged inside the outer sheath.

[0010] Preferably, protruding blocks are provided on both the inner and outer sides of the armor layer, and the protruding blocks are integrated with the armor layer, and the protruding blocks are inlaid with the elastic layer and the outer sheath.

[0011] Preferably, the outer wall of the outer sheath is coated with a wear-resistant coating.

[0012] Preferably, there are four cores, and the four cores are equidistantly arranged around the support frame, the filling layer is arranged in the gap between the four cores and the support frame, and the mica sheath is spirally wound and connected on the outside of the cable core.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model device is provided with a support frame, an elastic layer and reinforcing ribs. The support frame limits the laid wire core and can increase the structural strength of the cable core, preventing the wire core from being twisted together when subjected to external force, thereby improving the anti-twisting effect of the power cable. The elastic layer adopts thermoplastic elastomer, which is a new type of polymer material that exhibits rubber elasticity at room temperature and plastic processing characteristics at high temperature. It better protects the cable core when the power cable is twisted. The reinforcing ribs increase the structural strength of the outer sheath and improve the anti-twisting performance of the cable.

[0015] The utility model device is provided with a composite flame retardant layer, and the composite flame retardant layer is composed of a double-layer structure of a first flame retardant layer and a second flame retardant layer. The first flame retardant layer is made of flame retardant polyolefin, which is a polymer material with excellent fire retardant properties and contains flame retardants. It can slow down the combustion rate during combustion, has high thermal stability, is not easily deformed or degraded by heat, and reduces the incidence of fire accidents. The second flame retardant layer is made of flame retardant polyvinyl chloride, which can maintain stable performance at high temperatures, is not easily deformed or degraded, can protect the inside of the cable from damage in a fire, slow down the spread of flames, and increase the service life of the power cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 For the utility model Figure 1 A partial enlarged view of area A;

[0018] Figure 3 This is a cross-sectional view of the cable core of the present utility model;

[0019] Figure 4 This is a structural diagram of the connection between the support frame and the wire core of the utility model;

[0020] Figure 5 This is a structural diagram of the composite flame retardant layer of the present utility model;

[0021] Figure 6 This is a diagram showing the connection relationship between the armor layer, elastic layer and outer sheath of the utility model.

[0022] In the figure: 1. Cable core; 2. Filling layer; 3. Wire core; 4. Support frame; 5. Inner lining layer; 6. Composite flame retardant layer; 7. Elastic layer; 8. Outer sheath; 9. Reinforcement ribs; 10. Mica wrapping layer; 11. Armor layer; 12. Conductor; 13. Inner insulation layer; 14. Shielding layer; 15. Outer insulation layer; 16. First flame retardant layer; 17. Second flame retardant layer; 18. Wear-resistant coating; 19. Raised block. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0024] See also Figure 1-6 The utility model provides an embodiment: a twist-resistant flame-retardant medium-voltage power cable, comprising a cable core 1, the cable core 1 comprising a filling layer 2 and a core 3, a support frame 4 is provided inside the cable core 1, and the support frame 4 is arranged in a cross shape, the support frame 4 is arranged equidistantly along the core 3, a mica wrapping layer 10 is provided on the outside of the cable core 1, four cores 3 are provided, and the four cores 3 are arranged equidistantly around the support frame 4, the filling layer 2 is provided in the gap between the four cores 3 and the support frame 4, the mica wrapping Layer 10 is spirally wound and connected on the outside of the cable core 1. The inner lining layer 5 is provided on the outside of the mica sheathing layer 10, and the inner lining layer 5 is bonded to the mica sheathing layer 10. The outer surface of the inner lining layer 5 is provided with a composite flame retardant layer 6, and the composite flame retardant layer 6 is bonded to the inner lining layer 5. The outer surface of the composite flame retardant layer 6 is provided with an elastic layer 7, and the elastic layer 7 is bonded to the composite flame retardant layer 6. The outer surface of the elastic layer 7 is provided with an armor layer 11, and the armor layer 11 is bonded to the elastic layer 7. The outer surface of the armor layer 11 is provided with The outer sheath 8 is formed by extrusion between the outer sheath 8 and the armor layer 11. The core 3 includes a conductor 12, an inner insulating layer 13, a shielding layer 14 and an outer insulating layer 15. The conductor 12 is formed by twisting multiple metal wires. The inner insulating layer 13 is arranged on the outside of the conductor 12, the shielding layer 14 is arranged on the outside of the inner insulating layer 13, and the outer insulating layer 15 is arranged on the outside of the shielding layer 14. The inner insulating layer 13, the shielding layer 14 and the outer insulating layer 15 are extruded in sequence on the outside of the conductor 12. The anti-twisting performance of the cable is improved by increasing the thickness of the outer protective layer of the cable. The support frame 4 limits the laid core 3 and can increase the structural strength of the cable core 1, preventing the core 3 from being twisted into a piece when subjected to external force. The elastic layer 7 adopts thermoplastic elastomer, which is a new type of polymer material that exhibits rubber elasticity at room temperature and plastic processing characteristics at high temperature. The buffering performance of the power cable is improved, the cable core is better protected when subjected to external force, and the use effect of the power cable is improved.

[0025] See also Figure 1 、 Figure 2 and Figure 5The composite flame retardant layer 6 includes a first flame retardant layer 16 and a second flame retardant layer 17. The second flame retardant layer 17 is arranged on the outside of the first flame retardant layer 16. The first flame retardant layer 16 adopts flame retardant polyolefin. Flame retardant polyolefin is a polymer material with excellent fire retardant properties. It contains flame retardants and can slow down the combustion rate during combustion. It has high thermal stability and is not easily deformed or degraded by heat, thereby reducing the incidence of fire accidents. The second flame retardant layer 17 adopts flame retardant polyvinyl chloride, which can maintain stable performance at high temperatures, is not easily deformed or degraded, can protect the inside of the cable from damage in a fire, slow down the spread of flames, and increase the service life of the power cable.

[0026] See also Figure 1 and Figure 6 , the outer sheath 8 is provided with reinforcing ribs 9, there are six reinforcing ribs 9, and the reinforcing ribs 9 are integrated with the outer sheath 8, and the six reinforcing ribs 9 are equidistantly arranged inside the outer sheath 8, and raised blocks 19 are provided on both the inner and outer sides of the armor layer 11, and the raised blocks 19 are integrated with the armor layer 11, and the raised blocks 19 are inlaid with the elastic layer 7 and the outer sheath 8. The outer wall of the outer sheath 8 is coated with a wear-resistant coating 18, and the reinforcing ribs 9 increase the structural strength of the outer sheath 8 and improve the torsion resistance of the cable. The raised blocks 19 limit the assembled elastic layer 7 and the outer sheath 8 to prevent the outer protective layer from loosening when the cable is twisted. The wear-resistant coating 18 adopts polyurethane coating, which is a polymer material with good hardness and wear resistance. Compared with traditional polyurethane coatings, it has more superior performance, higher hardness, better weather resistance, heat resistance and chemical corrosion resistance.

[0027] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0028] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A twist-resistant flame-retardant medium-voltage power cable, comprising a cable core (1), characterized in that: The cable core (1) comprises a filling layer (2) and a wire core (3); a support frame (4) is provided inside the cable core (1), and the support frame (4) is arranged in a cross shape; the support frame (4) is arranged equidistantly along the wire core (3); a mica wrapping layer (10) is provided outside the cable core (1); an inner lining layer (5) is provided outside the mica wrapping layer (10), and the inner lining layer (5) is in contact with the mica wrapping layer (10); and the inner lining layer (5) is provided outside the inner lining layer (5). A composite flame retardant layer (6) is provided, and the composite flame retardant layer (6) is bonded to the inner lining layer (5); an elastic layer (7) is provided on the outside of the composite flame retardant layer (6), and the elastic layer (7) is bonded to the composite flame retardant layer (6); an armor layer (11) is provided on the outside of the elastic layer (7), and the armor layer (11) is bonded to the elastic layer (7); an outer sheath (8) is provided on the outside of the armor layer (11), and the outer sheath (8) and the armor layer (11) are formed by extrusion.

2. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: The wire core (3) comprises a conductor (12), an inner insulating layer (13), a shielding layer (14) and an outer insulating layer (15), and the conductor (12) is formed by twisting a plurality of metal wires, the inner insulating layer (13) is arranged outside the conductor (12), the shielding layer (14) is arranged outside the inner insulating layer (13), and the outer insulating layer (15) is arranged outside the shielding layer (14), and the inner insulating layer (13), the shielding layer (14) and the outer insulating layer (15) are sequentially extruded outside the conductor (12).

3. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: The composite flame retardant layer (6) comprises a first flame retardant layer (16) and a second flame retardant layer (17), wherein the second flame retardant layer (17) is arranged outside the first flame retardant layer (16).

4. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: The outer sheath (8) is provided with reinforcing ribs (9), six reinforcing ribs (9) are provided, and the reinforcing ribs (9) and the outer sheath (8) are provided as a whole, and the six reinforcing ribs (9) are provided at equal intervals inside the outer sheath (8).

5. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: Both inner and outer sides of the armor layer (11) are provided with raised blocks (19), and the raised blocks (19) and the armor layer (11) are integrated. The raised blocks (19) are embedded with the elastic layer (7) and the outer sheath (8).

6. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: The outer wall of the outer sheath (8) is coated with a wear-resistant coating (18).

7. The twist-resistant flame-retardant medium voltage power cable according to claim 1, characterized in that: Four cores (3) are provided, and the four cores (3) are arranged equidistantly around the support frame (4); the filling layer (2) is provided in the gaps between the four cores (3) and the support frame (4); and the mica wrapping layer (10) is spirally wound and connected on the outside of the cable core (1).

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