Halogen-free low-smoke flame-retardant medium-voltage power cable with high mechanical property

Abstract

The utility model relates to the technical field of power cables, and discloses a halogen-free low-smoke flame-retardant medium-voltage power cable with high mechanical performance, which comprises a plurality of wires, conductor shielding layers are fixedly connected to the outer walls of the plurality of wires, insulating layers are fixedly connected to the outer walls of the plurality of conductor shielding layers, and the insulating layers are fixedly connected to the outer walls of the plurality of conductors. The outer walls of the plurality of insulating layers are fixedly connected with insulating shielding layers, the outer walls of the plurality of insulating shielding layers are fixedly connected with metal shielding layers, the outer walls of the plurality of metal shielding layers are fixedly connected with the same flame-retardant filling layer, and the outer wall of the flame-retardant filling layer is fixedly connected with a flame-retardant wrapping tape layer. According to the utility model, the conductor shielding layer prevents partial discharge, the insulating layer isolates current, the insulation shielding layer delays insulation aging, the metal shielding layer shields interference, the filling layer and the belting layer stabilize the structure and block fire, the armor layer enhances mechanical strength, and the flame-retardant crusting layer delays combustion, thereby ensuring safe and stable power transmission of the cable.

Description

Technical Field

[0001] This utility model relates to the field of power cable technology, and in particular to a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable. Background Technology

[0002] High-performance halogen-free, low-smoke, flame-retardant medium-voltage power cables possess high strength, hardness, and tensile strength, enabling them to withstand significant external forces without easily deforming or breaking. During installation, they can withstand certain tensile and compressive forces, and in the operating environment, they can resist mechanical damage caused by vibration and impact, ensuring that the cables maintain good electrical performance and structural integrity during long-term use.

[0003] In low-smoke flame-retardant medium-voltage power cables, the performance of flame-retardant materials gradually declines over time and due to environmental factors, resulting in reduced flame-retardant efficiency and difficulty in maintaining stable flame-retardant effects over the long term. Existing technologies select polymer materials with good aging resistance as the cable matrix or sheath material and add anti-aging agents to effectively inhibit the aging and degradation of materials during long-term use, maintain the overall performance of the cable, and thus maintain the flame-retardant effect. However, in actual use, although aging-resistant materials can maintain good flame-retardant performance under normal operating conditions, their flame-retardant efficiency will be affected under extreme conditions such as ultra-high temperatures, ultra-strong external impacts, or prolonged exposure to harsh chemical environments, failing to provide sufficient protection. Utility Model Content

[0004] To overcome the above deficiencies, this utility model provides a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable, aiming to improve the problem that in some extreme conditions, such as ultra-high temperature, ultra-strong external impact, or long-term exposure to harsh chemical environments, the flame-retardant efficiency is still affected, and sufficient protection cannot be provided.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable includes multiple conductors. Each conductor has a conductor shielding layer fixedly connected to its outer wall. Each conductor shielding layer has an insulation layer fixedly connected to its outer wall. Each insulation layer has an insulating shielding layer fixedly connected to its outer wall. Each insulating shielding layer has a metal shielding layer fixedly connected to its outer wall. Each metal shielding layer has a single flame-retardant filling layer fixedly connected to its outer wall. A flame-retardant wrapping layer is fixedly connected to the outer wall of the flame-retardant wrapping layer. An isolation sleeve is fixedly connected to the outer wall of the isolation sleeve. An armor layer is fixedly connected to the outer wall of the armor layer. A flame-retardant shell layer is fixedly connected to the outer wall of the flame-retardant shell layer. An outer sheath is fixedly connected to the outer wall of the flame-retardant shell layer.

[0007] As a further description of the above technical solution:

[0008] A fixing ring is slidably connected to the middle of the outer wall of the outer sheath, and the inner diameter of the fixing ring is larger than the outer diameter of the outer sheath.

[0009] As a further description of the above technical solution:

[0010] A fixing ring is slidably connected to the middle of the outer wall of the outer sheath, and the inner diameter of the fixing ring is larger than the outer diameter of the outer sheath.

[0011] As a further description of the above technical solution:

[0012] A tie rod is fixedly connected to the top of the fixing block, and the top of the tie rod has a smooth design.

[0013] As a further description of the above technical solution:

[0014] The fixed ring is fixedly connected to both the front and rear sides of the fixed ring, and the two movable rings are both designed symmetrically.

[0015] As a further description of the above technical solution:

[0016] All of the aforementioned conductors are designed with equal spacing, and all of the aforementioned conductor shielding layers are designed with multiple layers.

[0017] As a further description of the above technical solution:

[0018] The metal shielding layer is a copper strip wrapped structure, and the flame-retardant filling layer is a high-temperature flame-retardant filling rope.

[0019] As a further description of the above technical solution:

[0020] The flame-retardant wrapping layer is a halogen-free, low-smoke flame-retardant wrapping layer, and the armor layer is a steel strip wrapping or a loosely wound steel wire structure.

[0021] This utility model has the following beneficial effects:

[0022] In this invention, the conductor shielding layer is made of semi-conductive material, creating a uniform electric field to prevent partial discharge; the insulation layer isolates current and prevents leakage; the insulating shielding layer eliminates charge accumulation and slows down insulation aging; the copper strip or copper wire braided metal shielding layer shields interference and conducts fault current; the filling layer and wrapping layer stabilize the structure and block fire; the armor layer enhances mechanical strength; the flame-retardant shell layer slows down combustion; and the outer sheath protects against environmental damage, thereby ensuring safe and stable power transmission of the cable. Attached Figure Description

[0023] Figure 1 This is a perspective view of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable according to the present invention.

[0024] Figure 2 This is a front view of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable according to this utility model.

[0025] Figure 3 This is a right view of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable according to this utility model.

[0026] Figure 4 This is a schematic diagram of the conductor structure of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable according to this utility model.

[0027] Figure 5 This is an exploded view of the fixing ring of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable according to this utility model.

[0028] Legend:

[0029] 1. Wire; 2. Conductor shielding layer; 3. Insulation layer; 4. Insulation shielding layer; 5. Metal shielding layer; 6. Flame-retardant filling layer; 7. Flame-retardant wrapping layer; 8. Isolation sleeve; 9. Armoring layer; 10. Flame-retardant shell layer; 11. Outer sheath; 12. Fixing ring; 13. Fixing block; 14. Pull rod; 15. Moving ring. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0031] Reference Figure 1 , Figure 2 and Figure 4This utility model provides an embodiment of a high-mechanical-performance halogen-free, low-smoke, flame-retardant medium-voltage power cable, comprising multiple conductors 1. Each conductor 1 has a conductor shielding layer 2 fixedly connected to its outer wall. The conductor shielding layer 2 can uniformly distribute the electric field around the conductors 1, avoiding local electric field concentration, thereby improving the stability and safety of cable operation. Each conductor shielding layer 2 has an insulation layer 3 fixedly connected to its outer wall. The insulation layer 3 can effectively isolate the conductors, prevent current leakage, and ensure the reliability of power transmission. Each insulation layer 3 has an insulation shielding layer 4 fixedly connected to its outer wall. The insulation shielding layer 4 can eliminate charge accumulation on the surface of the insulation layer 3, further uniformize the electric field, and protect the insulation layer 3. Each insulation shielding layer 4 has a metal shielding layer 5 fixedly connected to its outer wall. The metal shielding layer 5 can shield electromagnetic interference and also acts as a short-circuit current path when the cable fails, improving cable safety. Each metal shielding layer 5 has a single flame-retardant filling layer 6 fixedly connected to its outer wall. The flame-retardant filling layer 6 can fill the internal voids of the cable. The flame-retardant filling layer 6 enhances the stability of the cable structure and also has a flame-retardant effect, preventing the spread of flames. A flame-retardant wrapping layer 7 is fixedly connected to the outer wall of the flame-retardant filling layer 6. The flame-retardant wrapping layer 7 further enhances the flame-retardant performance of the cable and also plays a role in wrapping and fixing the internal structure. An isolation sleeve 8 is fixedly connected to the outer wall of the flame-retardant wrapping layer 7. The isolation sleeve 8 can isolate the flame-retardant wrapping layer 7 from the armor layer 9, preventing the armor layer 9 from damaging the internal structure. An armor layer 9 is fixedly connected to the outer wall of the isolation sleeve 8. The armor layer 9 can enhance the mechanical strength of the cable, giving it good compressive, tensile, and impact resistance, protecting the internal structure from external force damage. A flame-retardant shell layer 10 is fixedly connected to the outer wall of the armor layer 9. The flame-retardant shell layer 10 forms a shell when the cable is burning, preventing the flame from burning further and improving the flame-retardant ability of the cable. An outer sheath 11 is fixedly connected to the outer wall of the flame-retardant shell layer 10. The outer sheath 11 can protect all internal structures of the cable from the effects of external environment such as moisture, corrosion, and mechanical damage, extending the service life of the cable.

[0032] Specifically, the conductor 1 is made of high-purity oxygen-free copper or aluminum to ensure good conductivity. A conductor shielding layer 2 is fixedly connected to the outer wall of the conductor 1. The conductor shielding layer 2 is made of semi-conductive material, which can uniformly distribute the electric field around the conductor 1, avoid local electric field concentration, thereby improving the stability and safety of cable operation and effectively preventing damage to the cable caused by partial discharge.

[0033] Multiple conductor shielding layers 2 are covered with an insulation layer 3. The insulation layer 3 is made of high-performance cross-linked polyethylene insulation material, which can effectively isolate conductors, prevent current leakage, ensure the reliability of power transmission, and ensure that the cable can stably transmit power in a medium-voltage environment. The outer wall of the insulation layer 3 is provided with an insulation shielding layer 4, which is also composed of semi-conductive material. The insulation shielding layer 4 can eliminate the charge accumulation on the surface of the insulation layer 3, further homogenize the electric field, protect the insulation layer 3, and avoid accelerated aging of the insulation layer due to uneven charge distribution. The outer walls of the multiple insulation shielding layers 4 are connected to a metal shielding layer 5. The metal shielding layer 5 is made of copper strip or copper wire braid, which can shield electromagnetic interference, ensure the normal operation of surrounding electronic equipment, and at the same time act as a short-circuit current channel when the cable fails, improving the safety of the cable and facilitating fault detection and repair.

[0034] Multiple metal shielding layers 5 are wrapped with flame-retardant filling layers 6. The flame-retardant filling layer 6 uses halogen-free flame-retardant material, which fills the internal gaps of the cable, enhances the cable's structural stability, and maintains its good shape during laying and use. It also has a flame-retardant effect, preventing the spread of flames. The outer wall of the flame-retardant filling layer 6 is a flame-retardant wrapping layer 7, which is made of halogen-free flame-retardant tape. This further enhances the cable's flame-retardant performance and also acts as a binding and fixing element for the internal structure, preventing displacement of the layers during cable bending and stretching. An isolation sleeve 8, made of rubber or plastic, is installed on the outer wall of the flame-retardant wrapping layer 7. This sleeve isolates the flame-retardant wrapping layer 7 from the armor layer 9, preventing damage to the internal structure from the armor layer 9 and avoiding damage to the internal insulation structure due to friction from the metal material of the armor layer. The outer wall of the isolation sleeve 8 is covered with the armor layer 9, which uses steel tape or wire armor. This enhances the cable's mechanical strength, giving it good resistance to compression, tension, and impact, protecting the internal structure. Unaffected by external forces and suitable for complex laying environments, the outer wall of the armor layer 9 is connected to the flame-retardant shell layer 10. The flame-retardant shell layer 10 forms a shell when the cable is burning, preventing further combustion of the flame, improving the flame-retardant ability of the cable, and effectively delaying the spread of fire. The outer wall of the flame-retardant shell layer 10 is covered with the outer sheath 11, which is made of halogen-free, low-smoke flame-retardant polyolefin material. By combining nano-level flame retardants such as magnesium hydroxide / aluminum hydroxide nanoparticles with the polyolefin substrate, the flame-retardant efficiency is improved by more than 30%, while avoiding the negative impact of traditional flame retardants on mechanical properties. The material has a tensile strength ≥15.0MPa, an elongation at break ≥360%, and an oxygen index ≥29. At the same time, a segmented cooling method is adopted during the extrusion process to reduce stress concentration caused during production, so as to prevent stress cracking of the cable outer sheath 11. It can protect all internal structures of the cable from the effects of external environment such as moisture, corrosion, and mechanical damage, extend the service life of the cable, and ensure long-term stable operation of the cable in harsh environments.

[0035] Reference Figure 1 , Figure 3 and Figure 5A fixed ring 12 is slidably connected to the middle of the outer wall of the outer sheath 11. The inner diameter of the fixed ring 12 is larger than the outer diameter of the outer sheath 11. The fixed ring 12 can slide back and forth on the outer wall of the outer sheath 11. A fixed block 13 is fixedly connected to the top of the fixed ring 12. The outer wall of the fixed block 13 is chamfered to prevent damage. A pull rod 14 is fixedly connected to the top of the fixed block 13. The top of the pull rod 14 is rounded. Pulling the pull rod 14 causes the fixed ring 12 to move back and forth. Movable rings 15 are fixedly connected to the front and rear sides of the fixed ring 12. The two movable rings 15 are symmetrically designed. When the fixed ring 12 moves, it drives the movable rings 15 to move back and forth, which can wipe away the dust on the surface of the outer sheath 11.

[0036] Specifically, a fixing ring 12 is slidably connected to the middle of the outer wall of the outer sheath 11. The inner diameter of the fixing ring 12 is larger than the outer diameter of the outer sheath 11, allowing it to slide freely back and forth along the outer sheath 11, facilitating cable maintenance. A fixing block 13 is fixedly connected to the top of the fixing ring 12, and its outer wall is chamfered to effectively prevent sharp edges from causing injury to operators or surrounding equipment, thus improving safety. The top of the fixing block 13 has a rounded top for easy gripping, allowing operators to flexibly control the fixing ring 12 by pulling the lever 14. The movable rings 15, which are symmetrically arranged on the front and rear sides of the fixed ring 12, are fixedly connected to the fixed ring 12. When the pull rod 14 is pulled to make the fixed ring 12 slide on the outer sheath 11, the movable rings 15 move synchronously and fit tightly against the surface of the outer sheath 11. This effectively wipes away the dust and impurities attached to the surface of the outer sheath 11, and can promptly remove dirt from the surface of the outer sheath. This prevents dust accumulation from affecting the heat dissipation performance of the cable, avoids accelerated aging of the outer sheath due to dust accumulation, and thus extends the service life of the cable and ensures long-term stable operation of the cable.

[0037] Reference Figure 1 , Figure 2 and Figure 4 Multiple conductors 1 are equidistant, multiple conductor shielding layers 2 are multi-layered, metal shielding layer 5 is a copper strip wrapping or copper wire loose winding structure, flame retardant filling layer 6 is a high temperature flame retardant filling rope, flame retardant wrapping layer 7 is a wrapping halogen-free low smoke flame retardant wrapping tape, armor layer 9 is a steel strip wrapping or steel wire loose winding structure.

[0038] Specifically, multiple conductors 1 are designed with equal spacing, which can effectively reduce electromagnetic interference between conductors and ensure stable current transmission. Multiple conductor shielding layers 2 have a multi-layer structure. Through the combination of different materials, the electric field distribution is further optimized and the insulation performance is improved. The metal shielding layer 5 adopts a copper tape wrapping or copper wire loose winding structure, which can efficiently shield electromagnetic interference and quickly conduct fault current. The flame-retardant filling layer 6 uses high-temperature flame-retardant filling rope, which provides reliable flame-retardant protection by filling the gaps inside the cable and enhancing the structural stability. The flame-retardant wrapping layer 7 uses a wrapping halogen-free low-smoke flame-retardant wrapping tape, which further enhances the flame-retardant effect and produces low smoke and non-toxicity when burning. The armor layer 9 adopts a steel tape wrapping or steel wire loose winding structure, which significantly enhances the mechanical strength of the cable and resists external mechanical damage.

[0039] Working Principle: A high-purity oxygen-free copper or aluminum conductor 1 serves as the current carrier, ensuring efficient power transmission thanks to its excellent conductivity. As current flows through conductor 1, the conductor shielding layer 2, made of semi-conductive material, provides a uniform electric field, preventing localized electric field concentration and damage to the cable from partial discharge, thus ensuring stable current transmission. The insulation layer 3, made of cross-linked polyethylene, isolates the conductor, preventing current leakage and ensuring reliable power transmission. The insulating shielding layer 4 further eliminates charge accumulation on the surface of the insulation layer 3, optimizes the electric field distribution, and slows down insulation aging. The metal shielding layer 5, woven from copper strips or wires, not only shields against electromagnetic interference but also protects the surrounding environment. When the equipment is running normally, it can also serve as a short-circuit current channel in case of cable faults, facilitating fault detection and repair. The halogen-free flame-retardant materials of the flame-retardant filling layer 6 and the flame-retardant wrapping layer 7 stabilize the internal structure when the cable is running normally and prevent the spread of flames when encountering a fire. The isolation sleeve 8 prevents the armor layer 9 from damaging the internal structure. The armor layer 9, made of steel strip or steel wire, enhances the mechanical strength of the cable and adapts to complex laying environments. The flame-retardant shell layer 10 forms a barrier layer during combustion, slowing down the fire. The outermost halogen-free low-smoke flame-retardant polyolefin outer sheath 11 isolates the cable from external moisture, corrosion and mechanical damage, providing comprehensive protection for the internal structure of the cable, ultimately achieving safe, stable and durable power transmission.

[0040] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A high mechanical performance halogen-free low smoke flame-retardant medium voltage power cable comprising a plurality of conductors (1), characterized in that: The outer wall of the plurality of wires (1) is fixedly connected with a conductor shielding layer (2), the outer wall of the plurality of conductor shielding layers (2) is fixedly connected with an insulation layer (3), the outer wall of the plurality of insulation layers (3) is fixedly connected with an insulation shielding layer (4), the outer wall of the plurality of insulation shielding layers (4) is fixedly connected with a metal shielding layer (5), the outer wall of the plurality of metal shielding layers (5) is fixedly connected with the same flame-retardant filling layer (6), the outer wall of the flame-retardant filling layer (6) is fixedly connected with a flame-retardant wrapping layer (7), the outer wall of the flame-retardant wrapping layer (7) is fixedly connected with an isolation sleeve (8), the outer wall of the isolation sleeve (8) is fixedly connected with an armored layer (9), the outer wall of the armored layer (9) is fixedly connected with a flame-retardant crust layer (10), and the outer wall of the flame-retardant crust layer (10) is fixedly connected with an outer sheath (11).

2. A halogen-free, low smoke, flame-retardant medium voltage power cable with high mechanical properties according to claim 1, characterized in that: The outer wall of the outer sheath (11) is slidably connected with a fixing ring (12) in the middle, and the inner diameter of the fixing ring (12) is greater than the outer diameter of the outer sheath (11).

3. A halogen-free, low smoke, flame-retardant medium voltage power cable with high mechanical properties according to claim 2, characterized in that: The top of the fixing ring (12) is fixedly connected with a fixing block (13), and the outer wall of the fixing block (13) is designed in a chamfered manner.

4. A halogen-free, low smoke, flame-retardant medium voltage power cable with high mechanical properties according to claim 3, characterized in that: The top of the fixing block (13) is fixedly connected with a pull rod (14), and the top of the pull rod (14) is designed in a round and smooth manner.

5. A halogen-free, low smoke, flame-retardant medium voltage power cable with high mechanical properties according to claim 2, characterized in that: The front and rear sides of the fixing ring (12) are fixedly connected with moving rings (15), and the two moving rings (15) are designed in a symmetrical manner.

6. A halogen-free, low smoke, flame-retardant medium voltage power cable with high mechanical properties according to claim 1, characterized in that: The plurality of wires (1) are designed at equal intervals, and the plurality of conductor shielding layers (2) are designed in multiple layers.

7. A halogen-free, low smoke, flame-retardant, medium voltage power cable with high mechanical properties according to claim 1, characterized in that: The metal shielding layer (5) is a copper tape wrapping structure, and the flame-retardant filling layer (6) is a high-temperature flame-retardant filling rope.

8. A halogen-free, low smoke, flame-retardant, medium voltage power cable with high mechanical properties according to claim 1, characterized in that: The flame-retardant wrapping layer (7) is a wrapping halogen-free low-smoke flame-retardant wrapping, and the armored layer (9) is a steel tape wrapping or steel wire sparse wrapping structure.

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