Steel-cored aluminum stranded cable with polyethylene insulation

Abstract

The application discloses a kind of steel-cored aluminium stranded conductor polyethylene insulated overhead cable, belong to cable technical field, this steel-cored aluminium stranded conductor polyethylene insulated overhead cable, including outer sheath, the inner side of outer sheath is provided with outer layer protection mechanism, and the outer side of outer layer protection mechanism is provided with anti-freezing mechanism, the inside of outer layer protection mechanism is evenly provided with seven columns strip hollow air bag along outer sheath axial direction, and adjacent two column strip hollow air bag is staggered distribution, the inner side of outer layer protection mechanism is provided with inner layer protection mechanism.The application is provided with anti-freezing mechanism on rubber layer, and make that strip heat conduction piece is located at the bottom position of overhead cable outer sheath inner side, only through carbon fiber heating wire cooperation strip heat conduction piece icing treatment is carried out to hang ice located at the bottom of outer sheath outer side, neither too much increase the self weight of overhead cable, can realize the effect of heating and deicing to overhead cable outer side.

Description

Technical Field

[0001] This invention belongs to the field of cable technology, specifically relating to a steel-cored aluminum stranded polyethylene insulated overhead cable. Background Technology

[0002] Because overhead cables need to withstand tension and transmit current, they must have good mechanical and electrical properties. Taking the most common steel-cored aluminum stranded overhead cable as an example, the steel strand has high mechanical strength and poor conductivity, so it mainly bears mechanical loads. The aluminum strand has lower mechanical properties and good conductivity, so it mainly transmits electrical energy. Also, due to the skin effect of alternating current, the current tends to concentrate on the surface of the conductor. Therefore, the steel strand is arranged inside and the aluminum strand is arranged outside.

[0003] In practical applications of steel-cored aluminum stranded polyethylene insulated overhead cables, traditional overhead cable structures are prone to excessive sag when facing large spans or their own weight. This not only affects the aesthetics of the line but may also pose safety hazards. Furthermore, in cold weather, the bottom outer side of the steel-cored aluminum stranded polyethylene insulated overhead cable often gradually accumulates ice. As the weight of the ice increases, it greatly increases the cable's load, making it highly susceptible to breakage. Although existing overhead cables are equipped with heating structures, they often completely wrap the cable to ensure the effect of heating and de-icing, which greatly increases the cable's own load. At the same time, the outer side of existing steel-cored aluminum stranded polyethylene insulated overhead cables is very prone to the adhesion of a large amount of water droplets, which not only increases the cable's load in rainy weather but also increases the amount of ice accumulation on the overhead cable in freezing rain. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a steel-cored aluminum stranded polyethylene insulated overhead cable.

[0005] The technical solution adopted to solve the above-mentioned technical problems is: a steel-cored aluminum stranded polyethylene insulated overhead cable, including an outer sheath, an outer protective mechanism provided on the inner side of the outer sheath, and an anti-freezing mechanism provided on the outer side of the outer protective mechanism, seven rows of strip-shaped air bladders uniformly arranged along the axial direction of the outer sheath inside the outer protective mechanism, and adjacent rows of strip-shaped air bladders are staggered, an inner protective mechanism is provided on the inner side of the outer protective mechanism, a cable core body is provided on the inner side of the inner protective mechanism, and an anti-adhesion mechanism is provided on the outer side of the outer sheath.

[0006] Furthermore, the outer protective mechanism includes a rubber layer located inside the outer sheath, with eight sets of reinforcing steel wires evenly arranged inside the rubber layer along the axial direction of the outer sheath. A limit mechanism is provided on the inner side of the outer sheath and the outer side of the rubber layer, and the strip-shaped air bladder is located inside the rubber layer.

[0007] The above technical solution utilizes reinforcing steel wires to further improve the axial tensile strength of the entire cable. The rubber layer is equipped with seven rows of staggered strip-shaped air pockets, forming a honeycomb-like support structure. When the cable is subjected to gravity and sags, the structure of the strip-shaped air pockets can provide radial support.

[0008] Furthermore, the antifreeze mechanism includes a strip-shaped groove on the outside of the rubber layer, and a strip-shaped heat-conducting sheet adapted to it is provided inside the strip-shaped groove. The side of the strip-shaped heat-conducting sheet and the strip-shaped groove that are close to each other are provided with carbon fiber heating wires. The strip-shaped heat-conducting sheet is located at the bottom of the outer side of the outer sheath.

[0009] The above technical solution utilizes carbon fiber heating wires to heat the strip-shaped heat-conducting sheet, which then targets and melts the ice buildup at the bottom of the outer sheath. This method achieves the effect of heating and de-icing the outer side of the overhead cable without excessively increasing its own load.

[0010] Furthermore, the cross-section of the strip-shaped heat-conducting sheet is arc-shaped, and the side of the strip-shaped heat-conducting sheet and the strip-shaped groove that are close to each other are provided with a placement groove that cooperates with the carbon fiber heating wire.

[0011] Through the above technical solution, the arc-shaped strip heat-conducting sheet combined with the strip groove helps to make the strip heat-conducting sheet fit more tightly between the outer sheath and the rubber layer, thereby ensuring the heating effect of the strip heat-conducting sheet at the bottom of the outer side of the outer sheath. The placement groove also helps to improve the heating effect of the carbon fiber heating wire on the strip heat-conducting sheet.

[0012] Furthermore, the inner protective mechanism includes a shielding layer located inside the rubber layer, a flame-retardant layer disposed inside the shielding layer, a cross-linked polyethylene layer disposed inside the flame-retardant layer, and an insulating layer disposed inside the cross-linked polyethylene layer.

[0013] Through the above technical solutions, the shielding layer can suppress electromagnetic interference and reduce signal attenuation, making it suitable for communication or power cables. The flame-retardant layer can prevent the spread of flames and improve the safety of the cable in fire scenarios. The cross-linked polyethylene layer and the insulation layer provide high insulation strength, reduce the risk of leakage, and ensure the reliability of power transmission.

[0014] Furthermore, the cable core body includes a first aluminum stranded wire layer located inside the insulation layer, a second aluminum stranded wire layer disposed inside the first aluminum stranded wire layer, and a steel core disposed inside the second aluminum stranded wire layer. A conductor wrapping tape that wraps around the steel core is disposed inside the insulation layer.

[0015] Through the above technical solution, the first aluminum stranded wire layer and the second aluminum stranded wire layer are used for the daily power transmission of the cable, while the steel core helps to improve the axial tensile strength of the entire overhead cable, and the conductor wrapping helps to separate the first aluminum stranded wire layer from the insulation layer.

[0016] Furthermore, the anti-adhesion mechanism includes a first protrusion and a second protrusion. The first protrusion and the second protrusion are evenly arranged on the outer side of the outer sheath along the axial direction of the outer sheath, and the first protrusion and the second protrusion are spaced apart. The height of the first protrusion is higher than that of the second protrusion. The first protrusion and the second protrusion are located on the outer side of the outer sheath near the strip-shaped heat-conducting sheet.

[0017] Through the above technical solution, the height of the first and second protrusions alternates periodically in a "high-low-high" pattern. The height difference creates a "gradient flow guiding" effect. The water flow velocity at the high protrusion is accelerated due to the large drop, while the water flow velocity at the low protrusion is slowed down. This change in flow velocity disrupts the surface tension of the water droplets, promoting their splitting or accelerating their detachment, thereby reducing the amount of water droplets adhering to the overhead cable. In addition, the first and second protrusions can also indicate the location of the strip heat-conducting sheet, making it easy to ensure that the strip heat-conducting sheet faces downwards when installing steel-cored aluminum stranded polyethylene insulated overhead cables, thus guaranteeing the heating and de-icing effect of the strip heat-conducting sheet.

[0018] Furthermore, a hydrophobic layer is provided on the outer side of both the first and second protrusions, and the first and second protrusions are hollow structures.

[0019] Through the above technical solution, the hydrophobic layer on the outer side of the first and second protrusions helps to improve the adhesion of waterproof beads to the overhead cable, and the hollow structure of the first and second protrusions can further reduce the self-load of the entire overhead cable.

[0020] Furthermore, both the first and second protrusions are quadrangular pyramidal structures, the distance between the first and second protrusions is 8-15mm, the height difference between the first and second protrusions is 30%-50%, and the cone angle of the first and second protrusions is 45°-60°.

[0021] The above technical solution helps to ensure that the first and second protrusions can better remove water droplets attached to the bottom of the outer side of the outer sheath, reducing the load on the entire overhead cable in rainy or freezing weather.

[0022] Furthermore, the limiting mechanism includes several sets of annular rubber protrusions evenly distributed on the inner side of the outer sheath, and several sets of annular grooves adapted to the annular rubber protrusions are evenly formed on the outer side of the rubber layer and the strip heat-conducting sheet.

[0023] Through the above technical solution, the annular rubber protrusion on the inner side of the outer sheath cooperates with the annular groove of the rubber layer and the strip heat-conducting sheet to play a limiting role, preventing the strip heat-conducting sheet from shifting when the cable is bent or vibrated, and ensuring the continuity and reliability of the antifreeze function.

[0024] The beneficial effects of the present invention are as follows: (1) The present invention forms a support structure similar to a "honeycomb" by uniformly setting seven rows of staggered strip-shaped air pockets inside the rubber layer. When the cable sags under gravity, the structure of the strip-shaped air pockets can provide radial support force, offset part of the gravity load, reduce the cable sag, and improve the mechanical stability during overhead laying. The staggered distribution of adjacent strip-shaped air pockets can avoid stress concentration. The interlocking structure enhances the overall compressive strength, which is especially suitable for large-span overhead scenarios and reduces the risk of line breakage due to excessive sag. The eight sets of reinforcing steel wires set in the rubber layer are distributed along the axial direction, forming a "rigid-flexible combination" with the strip-shaped air pockets. The composite support system strengthens the steel wire and steel core to provide high tensile strength, and the strip-shaped air bladder absorbs vibration stress through elastic deformation. The combination of the two can improve the cable's tensile and bending resistance and extend its service life; (2) This invention sets an antifreeze mechanism on the rubber layer and places the strip-shaped heat-conducting plate at the bottom of the inner side of the outer sheath of the overhead cable. Only the carbon fiber heating wire and the strip-shaped heat-conducting plate are used to specifically de-ice the ice hanging at the bottom of the outer side of the outer sheath. This will not increase the load of the overhead cable too much, and can also achieve heating and de-icing of the outer side of the overhead cable. Effect; (3) By setting an anti-adhesion mechanism at the bottom of the outer side of the outer sheath, the height of the anti-adhesion mechanism alternates periodically in the pattern of "high-low-high". The height difference forms a "gradient flow guide" effect. The water flow speed at the high protrusion is accelerated due to the large drop, while the water flow speed at the low protrusion is slowed down. The change in flow velocity destroys the surface tension of the water droplets, promotes their splitting or accelerates their detachment, thereby reducing the amount of water droplets adhering to the overhead cable. It can also further reduce the amount of ice hanging on the overhead cable in freezing rain weather. In addition, with the anti-freezing mechanism, it can further reduce the amount of ice hanging on the outer side of the outer sheath and the anti-adhesion mechanism. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural diagram of the internal structure of the present invention;

[0026] Figure 2 This is a three-dimensional cross-sectional schematic diagram of the present invention;

[0027] Figure 3 This is a schematic diagram of the longitudinal section of the rubber layer of the present invention;

[0028] Figure 4 This is a three-dimensional schematic diagram of the rubber layer after the inner and outer layers of the present invention are separated;

[0029] Figure 5This is a three-dimensional schematic diagram of the connection between the rubber layer and the strip heat-conducting sheet of the present invention;

[0030] Figure 6 This is a schematic cross-sectional view of the rubber layer of the present invention;

[0031] Figure 7 This is a schematic diagram of the inner protective mechanism of the present invention;

[0032] Figure 8 This is a three-dimensional schematic diagram of the cable core body of the present invention;

[0033] Figure 9 This is a schematic diagram of the anti-adhesion mechanism of the present invention on the outer sheath;

[0034] Figure 10 This is a first-view structural diagram of the anti-adhesion mechanism of the present invention;

[0035] Figure 11 This is a second-view structural diagram of the anti-adhesion mechanism of the present invention;

[0036] Figure 12 This is the present invention. Figure 2 Enlarged view of point A.

[0037] Reference numerals: 1. Outer sheath; 2. Outer protective mechanism; 201. Rubber layer; 202. Reinforcing steel wire; 3. Anti-freeze mechanism; 301. Strip groove; 302. Strip heat-conducting sheet; 303. Carbon fiber heating wire; 4. Strip-shaped air bladder; 5. Inner protective mechanism; 501. Shielding layer; 502. Flame-retardant layer; 503. Cross-linked polyethylene layer; 504. Insulation layer; 6. Cable core body; 601. First aluminum stranded wire layer; 602. Second aluminum stranded wire layer; 603. Steel core; 7. Anti-adhesion mechanism; 701. First protrusion; 702. Second protrusion; 8. Limiting mechanism; 801. Annular groove; 802. Annular rubber protrusion; 9. Conductor wrapping tape. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0039] like Figures 1-8 and Figure 12As shown, this embodiment of a steel-cored aluminum stranded polyethylene insulated overhead cable includes an outer sheath 1. An outer protection mechanism 2 is provided inside the outer sheath 1. Seven rows of strip-shaped air bladders 4 are evenly arranged along the axial direction of the outer sheath 1 inside the outer protection mechanism 2, with adjacent rows of air bladders 4 staggered. An inner protection mechanism 5 is provided inside the outer protection mechanism 2, and a cable core body 6 is provided inside the inner protection mechanism 5. The outer protection mechanism 2 includes a rubber layer 201 located inside the outer sheath 1. Eight sets of reinforcing steel wires 202 are evenly arranged along the axial direction of the outer sheath 1 inside the rubber layer 201. A limiting mechanism 8 is provided on both the inner side of the outer sheath 1 and the outer side of the rubber layer 201. The strip-shaped air bladders 4 are located inside the rubber layer 201. The inner protective mechanism 5 includes a shielding layer 501 located inside the rubber layer 201. A flame-retardant layer 502 is disposed inside the shielding layer 501, a cross-linked polyethylene layer 503 is disposed inside the flame-retardant layer 502, and an insulation layer 504 is disposed inside the cross-linked polyethylene layer 503. The cable core body 6 includes a first aluminum stranded wire layer 601 located inside the insulation layer 504, a second aluminum stranded wire layer 602 disposed inside the first aluminum stranded wire layer 601, and a steel core 603 disposed inside the second aluminum stranded wire layer 602. A conductor wrapping tape 9 is disposed inside the insulation layer 504, enclosing the steel core 603. The reinforcing steel wire 202 further improves the axial tensile strength of the entire cable, while the seven rows of staggered strip-shaped air pockets 4 form a honeycomb-like structure. The supporting structure provides radial support when the cable sags under gravity. The structure of the strip-shaped air bladder 4 can offset part of the gravity load. Combined with the steel core 603, it can effectively improve the stability of the entire overhead cable structure in the overhead state, which can also ensure the stability of the power transmission of the first aluminum stranded layer 601 and the second aluminum stranded layer 602. The shielding layer 501, flame retardant layer 502, cross-linked polyethylene layer 503 and insulation layer 504 can also provide good protection for the first aluminum stranded layer 601 and the second aluminum stranded layer 602.

[0040] like Figures 4-6As shown, the outer protective mechanism 2 of this embodiment is provided with an antifreeze mechanism 3 on its outer side. The antifreeze mechanism 3 includes a strip-shaped groove 301 located on the outer side of the rubber layer 201. A strip-shaped heat-conducting sheet 302 adapted to it is provided inside the strip-shaped groove 301. A carbon fiber heating wire 303 is provided on the side of the strip-shaped heat-conducting sheet 302 and the side of the strip-shaped groove 301 that are close to each other. The strip-shaped heat-conducting sheet 302 is located at the bottom position of the outer side of the outer sheath 1. The cross-section of the strip-shaped heat-conducting sheet 302 is arc-shaped. A placement groove that cooperates with the carbon fiber heating wire 303 is provided on the side of the strip-shaped heat-conducting sheet 302 and the side of the strip-shaped groove 301 that are close to each other. By placing the strip-shaped heat-conducting sheet 302 at the bottom position of the inner side of the outer sheath 1, the ice hanging at the bottom of the outer side of the outer sheath 1 can be de-iced by the carbon fiber heating wire 303 in conjunction with the strip-shaped heat-conducting sheet 302. This will not increase the load on the overhead cable, but will also achieve the effect of heating and de-icing the outer side of the overhead cable.

[0041] like Figures 9-11 As shown, in this embodiment, an anti-adhesion mechanism 7 is provided on the outer side of the outer sheath 1. The anti-adhesion mechanism 7 includes a first protrusion 701 and a second protrusion 702. The first protrusion 701 and the second protrusion 702 are evenly distributed on the outer side of the outer sheath 1 along the axial direction of the outer sheath 1, and the first protrusion 701 and the second protrusion 702 are spaced apart. The height of the first protrusion 701 is higher than that of the second protrusion 702. The first protrusion 701 and the second protrusion 702 are located on the outer side of the outer sheath 1 near the strip-shaped heat-conducting plate 302. A hydrophobic layer is provided on the outer side of both the first protrusion 701 and the second protrusion 702. The first protrusion 701 and the second protrusion 702 are hollow structures. Both the first protrusion 701 and the second protrusion 702 are square pyramidal structures. The distance between the first protrusion 701 and the second protrusion 702 is 8-15mm, the height difference between the first protrusion 701 and the second protrusion 702 is 30%-50%, and the cone angle of the first protrusion 701 and the second protrusion 702 is 45°-60°. By setting the first protrusion 701 and the second protrusion 702 in a periodic alternation of "high-low-high", the height difference forms a "gradient flow guiding" effect. The water flow velocity at the high protrusion is accelerated due to the large drop, while the water flow velocity at the low protrusion is slowed down. The change in flow velocity disrupts the surface tension of the water droplets, promotes their splitting or accelerates their detachment, thereby reducing the amount of water droplets adhering to the overhead cable. The hollow structure of the first protrusion 701 and the second protrusion 702 can also effectively reduce the load of the entire overhead cable.

[0042] like Figures 5-6 and Figure 9As shown, the limiting mechanism 8 in this embodiment includes several sets of annular rubber protrusions 802 evenly distributed on the inner side of the outer sheath 1. Several sets of annular grooves 801 adapted to the annular rubber protrusions 802 are evenly opened on the outer side of the rubber layer 201 and the strip heat-conducting sheet 302. The annular rubber protrusions 802 on the inner side of the outer sheath 1 cooperate with the annular grooves 801 of the rubber layer 201 and the strip heat-conducting sheet 302 to play a limiting role, preventing the strip heat-conducting sheet 302 from shifting when the cable is bent or vibrated, and ensuring the continuity and reliability of the antifreeze function.

[0043] The working principle of this embodiment is as follows: When ice and snow accumulate on the overhead cable or birds trample it, the seven rows of strip-shaped air bladders 4 in the rubber layer 201 absorb energy through deformation, thus buffering the radial compressive stress generated by the ice and snow accumulation or birds trampling on the overhead cable. When it is raining, rainwater falls on the outside of the outer sheath 1 and gradually flows towards the bottom of the outer side of the outer sheath 1. The water droplets are split apart by the alternately distributed first protrusion 701 and second protrusion 702. The split water droplets gradually merge at the tips of the first protrusion 701 and the second protrusion 702. When the gravity acting on the water droplets at the tips of the first protrusion 701 and the second protrusion 702 is greater than the adhesion force between the water droplets and the surfaces of the first protrusion 701 and the second protrusion 702, the water droplets will quickly leave the bottom of the outer sheath 1. When the bottom of the surface of the outer sheath 1 is covered with ice due to rain or snow, the bottom of the outer side of the outer sheath 1 is heated by the carbon fiber heating wire 303 in conjunction with the strip heat-conducting plate 302, so that the contact area between the outer sheath 1, the first protrusion 701 and the second protrusion 702 and the ice gradually melts, and the ice leaves the overhead cable.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention.

Claims

1. A steel-cored aluminum stranded wire polyethylene insulated overhead cable, comprising an outer sheath (1), characterized in that: The outer sheath (1) is provided with an outer protection mechanism (2) on its inner side, and an antifreeze mechanism (3) is provided on the outer side of the outer protection mechanism (2). The outer protection mechanism (2) is provided with seven rows of strip-shaped air bladders (4) evenly arranged along the axial direction of the outer sheath (1) inside, and the adjacent rows of strip-shaped air bladders (4) are staggered. The outer protection mechanism (2) is provided with an inner protection mechanism (5) on its inner side, and the inner protection mechanism (5) is provided with a cable core body (6) on its inner side. The outer sheath (1) is provided with an anti-adhesion mechanism (7) on its outer side. The outer protective mechanism (2) includes a rubber layer (201) located inside the outer sheath (1). Eight sets of reinforcing steel wires (202) are uniformly arranged inside the rubber layer (201) along the axial direction of the outer sheath (1). A limit mechanism (8) is provided on the inner side of the outer sheath (1) and the outer side of the rubber layer (201). The strip-shaped air bladder (4) is located inside the rubber layer (201). The antifreeze mechanism (3) includes a strip groove (301) located on the outside of the rubber layer (201). The inside of the strip groove (301) is provided with a strip heat-conducting sheet (302) that is compatible with it. The side of the strip heat-conducting sheet (302) and the strip groove (301) that are close to each other are provided with a carbon fiber heating wire (303). The strip heat-conducting sheet (302) is located at the bottom of the outer side of the outer sheath (1). The anti-adhesion mechanism (7) includes a first protrusion (701) and a second protrusion (702). The outer side of the outer sheath (1) is uniformly provided with the first protrusion (701) and the second protrusion (702) along the axial direction of the outer sheath (1). The first protrusion (701) and the second protrusion (702) are distributed at intervals. The height of the first protrusion (701) is higher than that of the second protrusion (702). The first protrusion (701) and the second protrusion (702) are located on the outer side of the outer sheath (1) near the strip heat-conducting plate (302).

2. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 1, characterized in that, The cross-section of the strip heat-conducting sheet (302) is arc-shaped, and the side of the strip heat-conducting sheet (302) and the strip groove (301) that are close to each other are provided with a placement groove that cooperates with the carbon fiber heating wire (303).

3. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 1, characterized in that, The inner protective mechanism (5) includes a shielding layer (501) located inside the rubber layer (201), a flame-retardant layer (502) is provided inside the shielding layer (501), a cross-linked polyethylene layer (503) is provided inside the flame-retardant layer (502), and an insulating layer (504) is provided inside the cross-linked polyethylene layer (503).

4. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 3, characterized in that, The cable core body (6) includes a first aluminum stranded wire layer (601) located inside the insulation layer (504), a second aluminum stranded wire layer (602) is provided inside the first aluminum stranded wire layer (601), and a steel core (603) is provided inside the second aluminum stranded wire layer (602). A conductor wrapping tape (9) is provided inside the insulation layer (504) to wrap the steel core (603).

5. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 1, characterized in that, The first protrusion (701) and the second protrusion (702) are both provided with a hydrophobic layer on their outer sides, and the first protrusion (701) and the second protrusion (702) are hollow structures.

6. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 1, characterized in that, The first protrusion (701) and the second protrusion (702) are both square pyramid structures. The distance between the first protrusion (701) and the second protrusion (702) is 8-15mm. The height difference between the first protrusion (701) and the second protrusion (702) is 30%-50%. The cone angle of the first protrusion (701) and the second protrusion (702) is 45°-60°.

7. The steel-cored aluminum stranded polyethylene insulated overhead cable according to claim 1, characterized in that, The limiting mechanism (8) includes several sets of annular rubber protrusions (802) evenly distributed inside the outer sheath (1), and several sets of annular grooves (801) adapted to the annular rubber protrusions (802) are evenly opened on the outer side of the rubber layer (201) and the strip heat-conducting sheet (302).

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