Novel high-performance non-armored fireproof medium-voltage cable

Abstract

The utility model provides a novel high-performance non-armored fire-resistant medium-voltage cable. The novel high-performance non-armored fire-resistant medium-voltage cable comprises a wire core, a shielding layer group wrapping the periphery of the wire core, an inner isolation layer wrapping the periphery of the shielding layer group, a flame-retardant layer group wrapping the periphery of the inner isolation layer, and an outer sheath layer wrapping the periphery of the flame-retardant layer group. The flame-retardant layer group is composed of a first flame-retardant belt, an outer isolating layer and a second flame-retardant belt in sequence, the first flame-retardant belt wraps the periphery of the inner isolating layer, the outer isolating layer wraps the first flame-retardant belt, and the second flame-retardant belt wraps the outer isolating layer. Through the cooperation of the shielding layer group and the inner isolation layer, the anti-interference capability of the cable is significantly improved, and the radial mechanical strength is enhanced; the flame-retardant layer group adopts a gradient structure of a double-flame-retardant belt sandwich outer isolation layer, and the three layers cooperatively construct a three-dimensional fireproof barrier. And the outer sheath layer is made of a flexible ultraviolet aging resistant material and has excellent wear resistance and bending performance. The device has the advantages of simple structure, excellent comprehensive performance, convenience in construction, controllable cost and convenience in popularization and implementation.

Description

Technical Field

[0001] This application belongs to the field of new cable production technology, specifically relating to a new type of high-performance unarmored fire-resistant medium-voltage cable. Background Technology

[0002] In existing technologies, unarmored fire-resistant medium-voltage cables play a crucial role in power transmission, effectively ensuring the safety and reliability of circuits under extreme conditions such as fires. However, some shortcomings still exist in the unarmored fire-resistant medium-voltage cables currently on the market.

[0003] In existing technologies, unarmored fire-resistant medium-voltage cables typically employ a multi-layered structure, including a conductor, insulation layer, fire-resistant layer, and sheath. While these cables exhibit excellent fire resistance, their mechanical and bending properties are relatively poor. For example, traditional unarmored cables usually require a thick insulation layer to achieve fire resistance, resulting in a heavier cable and a larger bending radius, typically at least 20 times the cable diameter, which is detrimental to transportation and installation. Furthermore, the outer sheath is easily burned under fire conditions, and the inner fire-resistant layer may fail due to lack of protection when exposed to harsh environments such as water spray and vibration.

[0004] Furthermore, while existing unarmored fire-resistant medium-voltage cables can withstand a U0 voltage without breakdown during the entire test duration of 750–800°C, 120 minutes of fire supply, and 15 minutes of cooling, their fire resistance performance is no longer sufficient for more demanding applications.

[0005] Meanwhile, the fire-resistant layer of existing unarmored cables mostly uses mineral composite materials or intumescent insulation layers. Although these materials have certain fire resistance properties, in practical applications, due to their lack of mechanical strength and impact resistance, they are difficult to maintain safe power supply for a long time in dynamic environments.

[0006] Therefore, improvements are urgently needed to enhance the mechanical properties, fire resistance, and ease of construction of unarmored fire-resistant medium-voltage cables in order to meet the higher performance requirements of modern power systems. Utility Model Content

[0007] To address the technical problem that traditional unarmored fire-resistant medium-voltage cables in the prior art still have shortcomings in mechanical properties, fire resistance, and ease of construction, making it difficult to meet the performance requirements of modern power systems, this application proposes a new type of high-performance unarmored fire-resistant medium-voltage cable.

[0008] This application adopts the following scheme: a novel high-performance unarmored fire-resistant medium-voltage cable, comprising a conductor, a shielding layer group covering the outer periphery of the conductor, an inner isolation layer covering the outer periphery of the shielding layer group, a flame-retardant layer group covering the outer periphery of the inner isolation layer, and an outer sheath layer covering the outer periphery of the flame-retardant layer group. The flame-retardant layer group includes a first flame-retardant strip wrapped around the outer periphery of the inner isolation layer, an outer isolation layer covering the first flame-retardant strip, and a second flame-retardant strip covering the outer isolation layer.

[0009] In some feasible embodiments, the flame-retardant layer assembly further includes a mica tape extruded between the outer insulating layer and the second flame-retardant strip.

[0010] In some feasible embodiments, the inner insulating layer is made of any one of ceramicized silicone tape, ethylene propylene rubber, polytetrafluoroethylene, or polystyrene.

[0011] In some feasible embodiments, the materials of the first flame-retardant strip and the second flame-retardant strip are both selected from glass fiber, cross-linked polyethylene, and magnesium oxide.

[0012] In some feasible embodiments, the outer insulating layer is made of any one of ceramicized polyolefin, ceramicized silicone, or fireproof putty.

[0013] In some feasible embodiments, the shielding layer group includes a first shielding layer covering the outer periphery of the wire core, an insulating layer covering the outer periphery of the first shielding layer, a second shielding layer covering the outer periphery of the insulating layer, and a third shielding layer covering the outer periphery of the second shielding layer.

[0014] In some feasible embodiments, the material of the first shielding layer is selected from any one of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and graphene;

[0015] The material of the second shielding layer is selected from either ethylene-butyl acrylate copolymer or conductive carbon black;

[0016] The material of the third shielding layer is selected from any one of copper foil, aluminum foil, tin-plated copper, and stainless steel.

[0017] In some feasible embodiments, the thickness of the first shielding layer is greater than the thickness of the second shielding layer, and the thickness of the second shielding layer is greater than the thickness of the third shielding layer.

[0018] In some feasible embodiments, both the insulating layer and the outer sheath are made of polyvinyl chloride or cross-linked polyethylene.

[0019] In some feasible embodiments, the core is formed by twisting one or more strands of a complex conductor structure, and the number of the complex conductor structures is defined as Z, wherein Z satisfies the following relationship: 1≤Z≤5.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] This application provides a novel high-performance unarmored fire-resistant medium-voltage cable, comprising a conductor, a shielding layer assembly covering the outer periphery of the conductor, an inner insulating layer covering the outer periphery of the shielding layer assembly, a flame-retardant layer assembly covering the outer periphery of the inner insulating layer, and an outer sheath covering the outer periphery of the flame-retardant layer assembly. The flame-retardant layer assembly consists of a first flame-retardant strip, an outer insulating layer, and a second flame-retardant strip, sequentially arranged. The first flame-retardant strip wraps around the outer periphery of the inner insulating layer, the outer insulating layer covers the first flame-retardant strip, and the second flame-retardant strip covers the outer insulating layer. Through the cooperation of the shielding layer assembly and the inner insulating layer, the cable's anti-interference capability is significantly improved, and its radial mechanical strength is enhanced. The flame-retardant layer assembly adopts a gradient structure with a double flame-retardant strip sandwiching the outer insulating layer, and the three components work together to construct a three-dimensional fire barrier. The outer sheath layer uses a flexible, UV-resistant material, possessing both excellent abrasion resistance and bending performance. It has the advantages of simple structure, superior comprehensive performance, convenient construction, controllable cost, and ease of promotion and implementation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the cross-sectional structure of a novel high-performance unarmored fire-resistant medium-voltage cable in single-core state according to this application;

[0023] Figure 2 This is a schematic diagram of the cross-sectional structure of a novel high-performance unarmored fire-resistant medium-voltage cable in a multi-core state, as described in this application.

[0024] Figure 3 This is a schematic diagram of the cross-sectional structure of the stranded conductor structure of this application;

[0025] Figure 4 This application Figure 3 A magnified view of a section at point A in the middle;

[0026] Figure 5 This is a structural schematic diagram of the strengthening unit of this application. Detailed Implementation

[0027] Combination Figure 1-5The content shown further illustrates the technical solution provided in this application: a novel high-performance unarmored fire-resistant medium-voltage cable, comprising a conductor 1, a shielding layer group 2 covering the outer periphery of the conductor 1, an inner isolation layer 3 covering the outer periphery of the shielding layer group 2, a flame-retardant layer group 4 covering the outer periphery of the inner isolation layer 3, and an outer sheath layer 5 covering the outer periphery of the flame-retardant layer group 4. The flame-retardant layer group 4 includes a first flame-retardant strip 40 wrapped around the outer periphery of the inner isolation layer 3, an outer isolation layer 41 covering the first flame-retardant strip 40, and a second flame-retardant strip 42 covering the outer isolation layer 41.

[0028] This application provides a novel high-performance unarmored fire-resistant medium-voltage cable, comprising a conductor, a shielding layer assembly covering the outer periphery of the conductor, an inner insulating layer covering the outer periphery of the shielding layer assembly, a flame-retardant layer assembly covering the outer periphery of the inner insulating layer, and an outer sheath covering the outer periphery of the flame-retardant layer assembly. The flame-retardant layer assembly consists of a first flame-retardant strip, an outer insulating layer, and a second flame-retardant strip, sequentially arranged. The first flame-retardant strip wraps around the outer periphery of the inner insulating layer, the outer insulating layer covers the first flame-retardant strip, and the second flame-retardant strip covers the outer insulating layer. Through the cooperation of the shielding layer assembly and the inner insulating layer, the cable's anti-interference capability is significantly improved, and its radial mechanical strength is enhanced. The flame-retardant layer assembly adopts a gradient structure with a double flame-retardant strip sandwiching the outer insulating layer, and the three components work together to construct a three-dimensional fire barrier. The outer sheath layer uses a flexible, UV-resistant material, possessing both excellent abrasion resistance and bending performance. It has the advantages of simple structure, superior comprehensive performance, convenient construction, controllable cost, and ease of promotion and implementation.

[0029] In this embodiment, the flame-retardant layer group 4 further includes a mica strip 6 extruded between the outer isolation layer 41 and the second flame-retardant strip 42.

[0030] In this embodiment, the inner isolation layer 3 is made of any one of ceramicized silicone tape, ethylene propylene rubber, polytetrafluoroethylene, or polystyrene.

[0031] In actual implementation, the inner isolation layer 3 is made of ceramicized silicone tape.

[0032] In actual implementation, ceramicized silicone tape is a commonly used material in this field (see URL A below), and will not be elaborated here.

[0033] Website A: http: / / www.wave-vector.com / productDe_62.html.

[0034] In this embodiment, the materials of the first flame-retardant strip 40 and the second flame-retardant strip 42 are all selected from glass fiber, cross-linked polyethylene, and magnesium oxide.

[0035] In actual implementation, both the first flame-retardant strip 40 and the second flame-retardant strip 42 are made of glass fiber.

[0036] In this embodiment, the outer isolation layer 41 is made of any one of ceramicized polyolefin, ceramicized silicone, or fireproof putty.

[0037] In actual implementation, the outer isolation layer 41 is made of ceramicized polyolefin.

[0038] In actual implementation, ceramicized polyolefins are commonly used materials in this field (see URL B below), and will not be elaborated here.

[0039] Website B: https: / / www.keter.com.cn / product / 229.html

[0040] In this embodiment, the shielding layer group 2 includes a first shielding layer 20 covering the outer periphery of the wire core 1, an insulating layer 21 covering the outer periphery of the first shielding layer 20, a second shielding layer 22 covering the outer periphery of the insulating layer 21, and a third shielding layer 23 covering the outer periphery of the second shielding layer 22.

[0041] In this embodiment, the material of the first shielding layer 20 is selected from any one of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and graphene.

[0042] In actual implementation, the material of the first shielding layer 20 is ethylene-vinyl acetate copolymer.

[0043] The material of the second shielding layer 22 is selected from either ethylene-butyl acrylate copolymer or conductive carbon black;

[0044] In actual implementation, the material of the second shielding layer 22 is ethylene-butyl acrylate copolymer.

[0045] The material of the third shielding layer 23 is selected from any one of copper foil, aluminum foil, tin-plated copper, and stainless steel.

[0046] In actual implementation, the material of the third shielding layer 23 is copper foil.

[0047] In this embodiment, the thickness of the first shielding layer 20 is greater than the thickness of the second shielding layer 22, and the thickness of the second shielding layer 22 is greater than the thickness of the third shielding layer 23.

[0048] In this embodiment, the insulating layer 21 and the outer sheath layer 5 are both made of polyvinyl chloride or cross-linked polyethylene.

[0049] In this embodiment, the core 1 is formed by twisting one or more stranded conductor structures X together. The number of stranded conductor structures X is defined as Z, and Z satisfies the following relationship: 1≤Z≤5.

[0050] In actual implementation, the stranded conductor structure is formed by stranding a conductor body A1 and one or more reinforcing layers A2 covering the outer periphery of the conductor body A1. Each reinforcing layer A2 includes multiple reinforcing units A3 spaced around the axis of the conductor body A1 on the outer periphery of the conductor body A1, and connecting units A4 between adjacent reinforcing units A3. The number of reinforcing layers A2 is defined as N, and N satisfies the following relationship: 1≤N<5.

[0051] In actual implementation, N=3.

[0052] In this embodiment, the conductor body A1 is formed by twisting together multiple conductor single wires A10. The number of conductor single wires A10 is defined as M, and M satisfies the following relationship: 3 < M < 25.

[0053] In actual implementation, M=19.

[0054] In this embodiment, the reinforcing unit A3 is made of the same material as the conductor monofilament A10.

[0055] In this embodiment, the conductor monofilament A10 is made of any one of the following materials: T1 copper, T2 copper, 1050 aluminum, 1060 aluminum, tin-plated copper, or nickel-plated copper.

[0056] In actual implementation, the conductor single wire A10 is made of T1 copper.

[0057] In actual implementation, using T1 copper as the conductor monofilament material can significantly improve the conductor's conductivity, mechanical strength, and durability, while reducing production costs and maintenance difficulty, demonstrating significant technical advantages and practical application value.

[0058] In actual implementation, the reinforcing unit A3 is made of the same material as the conductor monofilament A10. This can effectively improve the conductivity of the conductor structure and prevent electrochemical reactions between the reinforcing layer and the conductor body.

[0059] In this embodiment, the twisting direction of the multiple conductor filaments A10 is defined as A, and the twisting direction of the conductor body A1 and one or more reinforcing layers A2 is defined as B, where A and B are the same.

[0060] In this embodiment, the pitch ratio of the multiple conductor wires A10 during the stranding process is selected as 15-20;

[0061] The pitch ratio of the conductor body A1 and one or more reinforcing layers A2 during the stranding process is selected to be 12-18.

[0062] In actual implementation, the pitch ratio of the multiple conductor wires A10 during the stranding process is selected as 18.

[0063] In actual implementation, the pitch ratio of the conductor body A1 and one or more reinforcing layers A2 during the stranding process is selected as 16.

[0064] In this embodiment, the connecting unit A4 includes connecting grooves A40 that are staggered on both sides of the reinforcing unit A3, and connecting protrusions A41 that are staggered on both sides of the reinforcing unit A3. The connecting protrusions A41 between two adjacent reinforcing units A3 can be matched and extended into the connecting grooves A40 so that the two reinforcing units A3 can be connected.

[0065] In this embodiment, the cross-sectional shape of the connecting groove A40 is semi-circular, and the shape of the connecting protrusion A41 matches the shape of the connecting groove A40.

[0066] In this embodiment, multiple reinforcing units A3 are arranged in a spiral pattern around the axis of the conductor body A1 and on the outer periphery of the conductor body A1.

[0067] In actual implementation, one or more interlocking reinforcing layers are set around the conductor body, which can effectively improve the structural stability of the conductor body and solve the overturning problem inherent in conventional conductor structures.

[0068] Furthermore, by setting one or more interlocking reinforcing layers around the conductor body, the conductor structure provided in this application does not involve any type of compression during stranding, thus preventing conductor hardening and increased conductor resistance, resulting in superior conductivity under the same cross-sectional conditions. The conductor structure has a smooth surface, eliminating conductor tip discharge and effectively improving cable lifespan.

[0069] This application provides a novel high-performance unarmored fire-resistant medium-voltage cable, comprising a conductor, a shielding layer assembly covering the outer periphery of the conductor, an inner insulating layer covering the outer periphery of the shielding layer assembly, a flame-retardant layer assembly covering the outer periphery of the inner insulating layer, and an outer sheath covering the outer periphery of the flame-retardant layer assembly. The flame-retardant layer assembly consists of a first flame-retardant strip, an outer insulating layer, and a second flame-retardant strip, sequentially arranged. The first flame-retardant strip wraps around the outer periphery of the inner insulating layer, the outer insulating layer covers the first flame-retardant strip, and the second flame-retardant strip covers the outer insulating layer. Through the cooperation of the shielding layer assembly and the inner insulating layer, the cable's anti-interference capability is significantly improved, and its radial mechanical strength is enhanced. The flame-retardant layer assembly adopts a gradient structure with a double flame-retardant strip sandwiching the outer insulating layer, and the three components work together to construct a three-dimensional fire barrier. The outer sheath layer uses a flexible, UV-resistant material, possessing both excellent abrasion resistance and bending performance. It has the advantages of simple structure, superior comprehensive performance, convenient construction, controllable cost, and ease of promotion and implementation.

[0070] The embodiments provided by this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A novel high-performance unarmored fire-resistant medium-voltage cable, characterized in that, It includes a wire core (1), a shielding layer group (2) covering the outer periphery of the wire core (1), an inner isolation layer (3) covering the outer periphery of the shielding layer group (2), a flame retardant layer group (4) covering the outer periphery of the inner isolation layer (3), and an outer sheath layer (5) covering the outer periphery of the flame retardant layer group (4). The flame retardant layer group (4) includes a first flame retardant strip (40) wrapped around the outer periphery of the inner isolation layer (3), an outer isolation layer (41) covering the first flame retardant strip (40), and a second flame retardant strip (42) covering the outer isolation layer (41).

2. The novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The flame-retardant layer group (4) also includes a mica tape (6) extruded between the outer insulating layer (41) and the second flame-retardant tape (42).

3. The novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The inner isolation layer (3) is made of any one of ceramicized silicone tape, ethylene propylene rubber, polytetrafluoroethylene, or polystyrene.

4. The novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The materials of the first flame-retardant strip (40) and the second flame-retardant strip (42) are both selected from glass fiber, cross-linked polyethylene, and magnesium oxide.

5. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The outer isolation layer (41) is made of any one of ceramicized polyolefin, ceramicized silicone, or fireproof putty.

6. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The shielding layer group (2) includes a first shielding layer (20) covering the outer periphery of the wire core (1), an insulating layer (21) covering the outer periphery of the first shielding layer (20), a second shielding layer (22) covering the outer periphery of the insulating layer (21), and a third shielding layer (23) covering the outer periphery of the second shielding layer (22).

7. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 6, characterized in that, The material of the first shielding layer (20) is selected from any one of ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and graphene; The material of the second shielding layer (22) is selected from either ethylene-butyl acrylate copolymer or conductive carbon black; The material of the third shielding layer (23) is selected from any one of copper foil, aluminum foil, tin-plated copper, and stainless steel.

8. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 6, characterized in that, The thickness of the first shielding layer (20) is greater than the thickness of the second shielding layer (22), and the thickness of the second shielding layer (22) is greater than the thickness of the third shielding layer (23).

9. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 6, characterized in that, The insulating layer (21) and the outer sheath layer (5) are both made of polyvinyl chloride or cross-linked polyethylene.

10. A novel high-performance unarmored fire-resistant medium-voltage cable according to claim 1, characterized in that, The core (1) is formed by twisting one or more strands of twisted conductor structure (X), and the number of the stranded conductor structure (X) is defined as Z, which satisfies the following relationship: 1≤Z≤5.

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