Water-blocking and rat-proof high performance medium voltage power cable

Abstract

The utility model relates to wire and cable technical field, more particularly to water -resistant rat -proof high -performance medium -voltage power cable, include: the core, including the copper conductor of many twisted, insulating layer, extruding in the outer wall of conductor core, inner water -resistant layer, cladding in the outer wall of insulating layer, shielding layer, cladding in the outer wall of inner water -resistant layer, outer water -resistant layer, cladding in the outer wall of shielding layer, elastic sheath layer, extruding in the outer wall of outer water -resistant layer. The position of the armor layer is set at the position of the outer diameter of the cable, and the armor layer is designed by using the longitudinal cladding of the aluminum plastic composite belt, so that the outer diameter of the armor layer is improved, and the smooth surface of the armor layer is not conducive to the force of rodents, which can effectively prevent biting, and also realizes the radial waterproof of the outermost layer. The inner layer of the armor layer is provided with an elastic layer, which can improve the bending performance of the cable. The water -resistant structure is arranged on the inner and outer layers of the shielding layer, which realizes longitudinal and radial protection.

Description

Technical Field

[0001] This utility model relates to the field of wire and cable technology, and more specifically to a water-blocking and rodent-proof high-performance medium-voltage power cable. Background Technology

[0002] Medium-voltage power cables play a crucial role in power transmission systems and are widely used in urban power grids, industrial plants, mines, and other locations. With economic development and technological advancements, the performance requirements for medium-voltage power cables are becoming increasingly stringent. In practical applications, medium-voltage power cables often need to be buried underground or laid in humid environments. Underground moisture levels are very high, and the cables may also be susceptible to damage from rodents and other animals, leading to damage to the cable insulation. Therefore, water resistance and rodent prevention are two critical aspects.

[0003] Traditional armored cables rely on embedded metal layers (such as steel strips) to enhance mechanical protection. However, the armor layers of small-diameter cables (outer diameter < 40mm) are difficult to effectively resist the bite damage of rodents due to their small outer diameter. Simply increasing the thickness of the metal layer leads to an increase in cable hardness, a decrease in flexibility, and a significant increase in cost. Summary of the Invention

[0004] To address the technical problems existing in rodent-proof medium-voltage power cables in the prior art, this utility model proposes a water-blocking and rodent-proof high-performance medium-voltage power cable, comprising: The conductor core consists of multiple stranded copper conductors; An insulating layer is extruded onto the outer wall of the conductor core; An inner water-blocking layer covers the outer wall of the insulating layer; A shielding layer, covering the outer wall of the inner water-blocking layer; An outer water-blocking layer covers the outer wall of the shielding layer; An elastic sheath layer is extruded onto the outer wall of the outer water-blocking layer; An armor layer, covering the outer wall of the elastic sheath layer; The outer sheath layer is extruded onto the outer wall of the armor layer; The armor layer includes a longitudinally wrapped aluminum-plastic composite strip, which includes a strip body, a first PE film located on a first side of the strip body, and a second PE film located on a second side of the strip body. The distance between the armor layer and the shielding layer is greater than the distance between the armor layer and the outer sheath layer.

[0005] Preferably, the thickness of the armor layer is 0.3~0.5mm.

[0006] Preferably, the thickness of the first PE film and the second PE film is greater than or equal to 0.1 mm.

[0007] Preferably, the longitudinal overlap rate of the belt is greater than 25%.

[0008] Preferably, the outer sheath layer includes a polyurethane sheath layer, and the thickness of the polyurethane sheath layer is 1.0~1.5mm.

[0009] Preferably, the elastic sheath layer comprises a thermoplastic elastomer sheath layer, and the thickness of the elastic sheath layer is 2.5~3mm.

[0010] Preferably, the shielding layer includes an inner shielding layer and an outer shielding layer, the inner shielding layer includes a copper strip shielding layer, and the outer shielding layer includes a copper wire braided shielding layer.

[0011] Preferably, the inner water-blocking layer includes a double-layer water-blocking tape wrapping layer, and the outer water-blocking layer includes an expanding water-blocking tape wrapping layer.

[0012] Preferably, the insulating layer includes a conductor shielding layer, a cross-linked polyethylene insulating layer, and an insulating shielding layer.

[0013] Preferably, the conductor core comprises multiple stranded oxygen-free copper conductors.

[0014] Compared with existing technologies, the water-blocking and rodent-proof high-performance medium-voltage power cable proposed in this utility model has an armor layer positioned closer to the outer diameter of the cable and employs a longitudinal wrapping design of aluminum-plastic composite tape, which increases the outer diameter of the armor layer. Simultaneously, its smooth surface makes it difficult for rodents to grip, effectively preventing biting and achieving radial waterproofing of the outermost layer. An elastic layer is provided within the armor layer to improve the cable's bending performance and reduce stress on the armor layer. Water-blocking structures are set in both the inner and outer layers of the shielding layer; the inner water-blocking tape achieves radial water blocking, while the outer expanding water-blocking tape enables dynamic self-healing, achieving both longitudinal and radial protection. Attached Figure Description

[0015] 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: Figure 1 This is a schematic diagram of the structure of the water-blocking and rodent-proof high-performance medium-voltage power cable shown in this utility model; Figure 2 This is a schematic diagram of the cross-sectional structure of the water-blocking and rodent-proof high-performance medium-voltage power cable shown in this utility model; Figure 3 This is a schematic diagram of the structure of the armor layer shown in this utility model; Figure 4This is a structural diagram showing the location of the armor layer in the prior art; Figure 5 This is a structural schematic diagram showing the location of the armor layer as indicated in this utility model. Detailed Implementation

[0016] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0017] Combination Figure 1 and Figure 2 As shown, this utility model proposes a water-blocking and rodent-proof high-performance medium-voltage power cable, including a conductor core 1, an insulation layer 2, an inner water-blocking layer 3, a shielding layer 4, an outer water-blocking layer 5, an elastic sheath layer 6, an armor layer 7, and an outer sheath layer 8.

[0018] The conductor core 1 comprises multiple stranded copper conductors. The copper conductors are preferably oxygen-free copper conductors, and a multi-layer stranded design is used to improve flexibility.

[0019] Furthermore, the insulation layer 2 is extruded onto the outer wall of the conductor core 1. The insulation layer 2 includes a conductor shielding layer 21, a cross-linked polyethylene insulation layer 22, and an insulation shielding layer 23.

[0020] Specifically, the conductor shielding layer is made of semi-conductive cross-linked polyethylene or ethylene propylene rubber with a thickness of 0.5~1.0mm, which can uniformly distribute the electric field on the conductor surface and avoid partial discharge. The cross-linked polyethylene insulation layer 22 has good heat resistance and mechanical strength, which can meet the application requirements. The insulation shielding layer 23 is made of semi-conductive cross-linked polyethylene with a thickness of 0.5~1.0mm, which is used to uniformly distribute the electric field on the surface of the insulation layer.

[0021] Furthermore, the inner water-blocking layer 3 covers the outer wall of the insulating layer 2, and the inner water-blocking layer 3 includes a double-layer water-blocking tape wrapping layer.

[0022] Optionally, the inner water-blocking layer 3 is a multi-layer wrapped water-blocking tape. The water-blocking tape uses a polyester non-woven fabric substrate and a water-absorbing resin coating. The number of wrapping layers of the water-blocking tape is more than two, and the overlap rate of each layer is more than 50%.

[0023] In this way, when the water-blocking tape comes into contact with water, the water-absorbing resin can expand rapidly, filling the tiny gaps between the shielding layer 4 and the insulation layer 2, preventing water from penetrating longitudinally along the cable core. At the same time, the non-woven fabric substrate can smooth the surface of the insulation shielding layer, reducing the electric field concentration at the contact point of the shielding layer 4.

[0024] Furthermore, the shielding layer 4 covers the outer wall of the inner water-blocking layer 3.

[0025] Optionally, the shielding layer 4 includes an inner shielding layer 41 and an outer shielding layer 42. The inner shielding layer 41 includes a copper strip shielding layer, and the outer shielding layer 42 includes a copper wire braided shielding layer.

[0026] Thus, the shielding layer adopts a copper strip wrapping + copper wire braiding shielding method, which can enhance the short-circuit current carrying capacity.

[0027] Furthermore, the outer water-blocking layer 5 covers the outer wall of the shielding layer 4.

[0028] Optionally, the outer water-blocking layer 5 is wrapped with an expansion water-blocking tape. The expansion water-blocking tape uses a butyl rubber matrix and highly expandable water-absorbing particles coated on the surface. The wrapping overlap rate of the expansion water-blocking tape is about 30%. When the cable is damaged, the expansion water-blocking tape absorbs water and expands to form a gel-like barrier, which automatically seals the cracks. At the same time, the expansion water-blocking tape can also absorb the deformation stress of the metal shielding layer.

[0029] Furthermore, the elastic sheath layer 6 is extruded onto the outer wall of the outer water-blocking layer 5. The elastic sheath layer 6 includes a thermoplastic elastomer sheath layer, and the thickness of the elastic sheath layer 6 is 2.5~3mm.

[0030] Thus, the elastic sheath layer 6 has high elasticity, which can buffer external mechanical impacts and is used to isolate the armor layer 7 and the shielding layer. It can prevent the deformation of the armor layer 7 from causing damage to the inner cable core, and at the same time improve the bending performance of the cable.

[0031] Furthermore, the armor layer 7 covers the outer wall of the elastic sheath layer 6, and the outer sheath layer 8 is extruded onto the outer wall of the armor layer 7.

[0032] The distance between the armor layer 7 and the shielding layer 4 is greater than the distance between the armor layer 7 and the outer sheath layer 8.

[0033] Combination Figure 4 As shown, in the prior art, a steel wire armor layer 20 is provided outside the cable core 10, and a sheath 30 is provided outside the steel wire armor layer 20. The ratio of the outer diameter D2 of the armor layer to the outer diameter D1 of the cable sheath is D2 / D1. Because the sheath 30 is thick, the ratio of D2 / D1 is relatively small. Figure 5 As shown, in this application, the outer diameter of the cable core 10 is D2, the outer diameter of the armor layer 7 is D3, and the outer diameter of the outer sheath is D1. Obviously, in this application, the diameter position of the armor layer 7 has been enlarged, D3 / D1>D2 / D1.

[0034] Thus, by increasing the outer diameter of the armor layer 7 in small-diameter cables (below 40mm), the difficulty for rodents to gnaw on them can be increased. It is preferable to control the outer diameter of the armor layer 7 to be above 35mm. Without significantly increasing the cost, the rodent-proof and mechanical impact-resistant capabilities of small-diameter cables can be significantly improved.

[0035] Combination Figure 3As shown, the armor layer 7 includes a longitudinally wrapped aluminum-plastic composite belt, which includes a belt body 71, a first PE film 72 located on the first side of the belt body 71, and a second PE film 73 located on the second side of the belt body 71.

[0036] Preferably, the thickness of the armor layer 7 is 0.3~0.5mm, and the thickness of the first PE film 72 and the second PE film 73 is greater than or equal to 0.1mm.

[0037] Among them, the longitudinal overlap rate of the belt 71 is greater than 25%.

[0038] Thus, through the longitudinal wrapping of the belt 71 and the sealing of the PE film, a water barrier can be formed, and the large-diameter smooth surface prevents rodents from biting and exerting force, thus achieving the effect of preventing biting.

[0039] Furthermore, the outer sheath layer 8 includes a polyurethane sheath layer with a thickness of 1.0~1.5mm.

[0040] Optionally, the polyurethane sheath layer can be made of nano-reinforced modified polyurethane, with a hardness of 95~98 Shore A. Increasing the hardness can improve wear resistance and resistance to biting.

[0041] In conjunction with the above embodiments, the armor layer is positioned at a location greater than the cable's outer diameter, and an aluminum-plastic composite tape longitudinal wrapping design is adopted to increase the outer diameter of the armor layer. At the same time, its smooth surface makes it difficult for rodents to grip, effectively preventing biting. It also achieves radial waterproofing of the outermost layer. An elastic layer is set in the inner layer of the armor layer to improve the cable's bending performance and reduce the stress on the armor layer. Water-blocking structures are set in the inner and outer layers of the shielding layer, respectively. The inner water-blocking tape can achieve radial water blocking, and the outer expansion water-blocking tape can achieve dynamic self-healing, achieving longitudinal and radial protection.

[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 water-blocking and rodent-proof high-performance medium-voltage power cable, characterized in that, include: The conductor core (1) comprises multiple stranded copper conductors; The insulating layer (2) is extruded onto the outer wall of the conductor core (1); An inner water-blocking layer (3) covers the outer wall of the insulating layer (2); A shielding layer (4) covers the outer wall of the inner water-blocking layer (3); An outer water-blocking layer (5) covers the outer wall of the shielding layer (4); An elastic sheath layer (6) is extruded onto the outer wall of the outer water-blocking layer (5); The armor layer (7) covers the outer wall of the elastic sheath layer (6); The outer sheath layer (8) is extruded onto the outer wall of the armor layer (7); The armor layer (7) includes a longitudinally wrapped aluminum-plastic composite belt, which includes a belt body (71), a first PE film (72) located on the first side of the belt body (71), and a second PE film (73) located on the second side of the belt body (71). Furthermore, the distance between the armor layer (7) and the shielding layer (4) is greater than the distance between the armor layer (7) and the outer sheath layer (8).

2. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The thickness of the armor layer (7) is 0.3~0.5mm.

3. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The thickness of the first PE film (72) and the second PE film (73) is greater than or equal to 0.1 mm.

4. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The longitudinal overlap rate of the belt (71) is greater than 25%.

5. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The outer sheath layer (8) includes a polyurethane sheath layer with a thickness of 1.0~1.5mm.

6. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The elastic sheath layer (6) includes a thermoplastic elastomer sheath layer, and the thickness of the elastic sheath layer (6) is 2.5~3mm.

7. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The shielding layer (4) includes an inner shielding layer (41) and an outer shielding layer (42). The inner shielding layer (41) includes a copper strip shielding layer, and the outer shielding layer (42) includes a copper wire braided shielding layer.

8. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The inner water-blocking layer (3) includes a double-layer water-blocking band wrapping layer, and the outer water-blocking layer (5) includes an expansion water-blocking band wrapping layer.

9. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The insulating layer (2) includes a conductor shielding layer (21), a cross-linked polyethylene insulating layer (22), and an insulating shielding layer (23).

10. The water-blocking and rodent-proof high-performance medium-voltage power cable according to claim 1, characterized in that, The conductor core (1) comprises multiple stranded oxygen-free copper conductors.

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