Moisture-proof halogen-free low-smoke flame-retardant B1-level fire-resistant medium-voltage power cable

Abstract

A moisture-proof halogen-free low-smoke flame-retardant B1-level fireproof medium-voltage power cable comprises a conductor, a conductor shielding layer is arranged outside the conductor, an insulating layer is arranged outside the conductor shielding layer, and a first fireproof layer is arranged outside the insulating shielding layer; a high-flame-retardant low-smoke halogen-free ceramic fire-resistant polyolefin fire-proof oxygen-isolating layer is arranged outside the first fire-proof layer, a second fire-proof layer is arranged outside the fire-proof oxygen-isolating layer, and the second fire-proof layer is formed by wrapping a plurality of layers of non-combustible ceramic silica gel belts; a moisture-proof shielding layer is arranged outside the second fireproof layer and is formed by overlapping and wrapping an aluminum-plastic composite belt; and a sheath layer made of a 90 DEG C irradiation crosslinking halogen-free low-smoke flame-retardant B1-level polyolefin material is arranged outside the moisture-proof shielding layer. The cable is simple in structure, small in outer diameter, round in appearance, soft in use, environment-friendly, economical, waterproof and moistureproof, and the cable is good in fireproof performance, physical and mechanical performance, electrical performance, environment-friendly, safe, halogen-free, low-smoke, highly flame-retardant, waterproof and moistureproof, and the like.

Description

Technical Field

[0001] The utility model belongs to the technical field of medium-voltage cables, in particular to a moisture-proof, halogen-free, low-smoke, flame-retardant, B1-level fire-resistant medium-voltage power cable. Background Art

[0002] With the continued growth of global electricity demand and the increasing complexity of power systems, the frequent occurrence of fires in power systems has become a significant safety hazard. This is particularly true in critical areas such as power plants and substations, where densely laid cables are located. A fire can not only damage equipment but also trigger large-scale power outages, seriously impacting normal social operations and public safety. Therefore, the use of fire-resistant cables to ensure uninterrupted power supply to critical circuits under extreme conditions, such as fire, has become a crucial measure for safeguarding the safety and stability of power systems. Medium-voltage fire-resistant cables, as a key link connecting high-voltage and low-voltage power grids, are becoming increasingly important.

[0003] Currently, medium-voltage fire-resistant cable technology is continuously evolving to meet the demands of power system upgrades and the increasing scale of industrial equipment. Technically, medium-voltage fire-resistant cables are being developed with features such as high-temperature tolerance, high-voltage carrying capacity, and large-section designs, aiming to improve operational stability and safety under extreme conditions. Furthermore, with growing environmental awareness, the development and application of low-smoke, halogen-free, fire-resistant cables and cables with high flame retardancy ratings are gaining increasing attention to reduce environmental pollution and the risk of casualties in fires.

[0004] Although existing medium-voltage fire-resistant cable technology has made some progress in improving safety and environmental protection, it still has several significant drawbacks. In particular, in specific application scenarios such as high-rise buildings, low-voltage fire-resistant cables are difficult to meet power supply needs due to voltage drop issues. Traditional medium-voltage fire-resistant cables often ignore moisture resistance and emit high levels of smoke and toxic gases in the event of a fire. Their flame retardancy is not sufficient to meet higher safety standards. Therefore, the market urgently needs a fire-resistant power cable that can meet medium-voltage power supply needs while also having excellent moisture resistance, low smoke and halogen-free properties, and a high flame retardancy rating (such as B1 grade) to comprehensively improve the safety and reliability of the power system. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a moisture-proof, halogen-free, low-smoke, flame-retardant, B1-level fire-resistant medium-voltage power cable.

[0006] The utility model is achieved in this way: a moisture-proof halogen-free, low-smoke, flame-retardant, B1-grade fire-resistant medium-voltage power cable comprises a conductor, characterized in that a conductor shielding layer is provided outside the conductor, the conductor shielding layer is composited by a semi-conductive shielding layer and a non-magnetic metal tape shielding, an insulating layer made of a 90°C irradiated cross-linked polyolefin material is provided outside the conductor shielding layer, a composite insulating shielding layer composed of a cross-linked semi-conductive material and a non-magnetic metal tape is provided outside the insulating shielding layer, a first fireproof layer is provided outside the insulating shielding layer, the first fireproof layer is wrapped with multiple layers of ceramic mica tape; a fireproof and oxygen-isolating layer of highly flame-retardant, low-smoke, halogen-free, ceramic fire-resistant polyolefin is provided outside the first fireproof layer, a second fireproof layer is provided outside the fireproof and oxygen-isolating layer, the second fireproof layer is wrapped with multiple layers of non-combustible ceramic silicone tape; a moisture-proof shielding layer is provided outside the second fireproof layer, the moisture-proof shielding layer is overlapped and wrapped with aluminum-plastic composite tape; a sheath layer of a 90°C irradiated cross-linked, halogen-free, low-smoke, flame-retardant, B1-grade polyolefin material is provided outside the moisture-proof shielding layer.

[0007] More preferably, the conductor has a nominal cross-section of 50 to 1600 mm 2 .

[0008] Further preferably, the conductor shielding layer has a thickness of 0.7-0.9 mm.

[0009] Further preferably, the insulating layer is made of 90° C. radiation cross-linked polyolefin material with a voltage level of 35 kV, and the insulation thickness is 9.3 to 10.5 mm.

[0010] Further preferably, the thickness of the insulating shielding layer is 0.7 to 0.9 mm.

[0011] Further preferably, the thickness of the fireproof layer is 0.8-2.0 mm.

[0012] More preferably, the thickness of the fireproof and oxygen-isolating layer is 1.2-2.0 mm.

[0013] Further preferably, the thickness of the second fireproof layer is 1.2-2.4 mm.

[0014] Further preferably, the thickness of the moisture-proof layer is 0.6 mm.

[0015] More preferably, the thickness of the sheath layer is 2.2-4.0 mm.

[0016] Advantages and technical effects of the utility model: The utility model cable achieves the following significant technical effects through a series of innovative structural and material designs:

[0017] 1. Medium voltage fire resistance: through structural and material design, the cable has super fire resistance, ensuring the electrical insulation performance of the medium voltage power cable while achieving the cable to maintain continuous power supply for 180 minutes in the event of a fire. At the same time, it can withstand the invasion of flames with a temperature of up to 1000°C, and has high fire resistance safety and reliability.

[0018] 2. Low smoke halogen-free B1 grade flame retardant cable has the following advantages: using halogen-free low smoke flame retardant B1 grade material, the cable releases low toxicity of gas when burning, low heat release, small flame spread range, small smoke production, and has environmental advantages.

[0019] 3. Composite shielding and moisture-proof design: The insulation has high working electric field strength, and the four-layer reinforced shielding design includes conductor, insulating semi-conductive shield, copper tape shield and aluminum-plastic composite tape. The cable has good shielding performance, small electric field radiation, easy manufacturing and installation, low dielectric loss and conductor loss, large current carrying capacity, and the aluminum-plastic composite tape wrapping makes the cable have excellent waterproof and moisture-proof properties.

[0020] 4. The insulation layer, shielding layer and sheath layer are all made of halogen-free, low-smoke flame-retardant materials to ensure that the cable as a whole has excellent halogen-free, low-smoke flame-retardant properties.

[0021] In summary, the cable of the utility model has achieved significant improvements in fire resistance, environmental protection and flame retardancy, shielding and moisture resistance, and overall safety performance, providing strong technical support for the safe, reliable and environmentally friendly operation of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram showing the cross-sectional structure of a moisture-proof, halogen-free, low-smoke, flame-retardant, B1-grade fire-resistant medium-voltage power cable of the present invention.

[0023] In the figure, 1. conductor, 2. conductor shield, 3. insulation layer, 4. insulation shield layer, 5. first fireproof layer, 6. fireproof and oxygen-isolating layer, 7. second fireproof layer, 8. moisture-proof shield layer, 9. sheath layer. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] See also Figure 1A moisture-proof, halogen-free, low-smoke, flame-retardant, B1-grade fire-resistant medium-voltage 35kV power cable, comprising a conductor 1, a conductor shielding layer 2 provided outside the conductor, the conductor shielding layer being composed of a semi-conductive shielding layer and a non-magnetic metal tape shielding composite, an insulating layer 3 made of a 90°C irradiated cross-linked polyolefin material provided outside the conductor shielding layer, a composite insulating shielding layer 4 composed of a cross-linked semi-conductive material and a non-magnetic metal tape provided outside the insulating layer, the cross-linked semi-conductive material of the conductor shielding layer 2, the insulating layer 3 and the composite insulating shielding layer being produced by a three-layer co-extrusion process, the non-magnetic metal tape of the composite insulating shielding layer 4 being formed by overlapping and wrapping 0.12mm thick copper tape; a first fireproof layer 5 is provided outside the insulating shielding layer. The first fireproof layer is wrapped with multiple layers of ceramic mica tape to ensure that the wrapping is tight, flat and wrinkle-free; the first fireproof layer is provided with a fireproof and oxygen-insulating layer 6 of highly flame-retardant, low-smoke, halogen-free ceramic fire-resistant polyolefin. A semi-extrusion mold is used for production during extrusion to ensure the thickness and tightness of the protective layer. A second fireproof layer 7 is provided outside the fireproof and oxygen-insulating layer. The second fireproof layer is wrapped with multiple layers of non-combustible ceramic silicone tape to form an ultra-strong fireproof layer; a moisture-proof shielding layer 8 is provided outside the second fireproof layer, and the moisture-proof shielding layer is overlapped and wrapped with aluminum-plastic composite tape; the moisture-proof shielding layer is provided with a sheath layer 9 of 90°C irradiated cross-linked halogen-free, low-smoke, flame-retardant B1 grade polyolefin material. The material has excellent physical and mechanical properties, halogen-free, low-smoke, flame-retardant B1 performance, waterproof and moisture-proof properties, etc.

[0026] More preferably, the conductor has a nominal cross-section of 50 to 1600 mm 2 By selecting the nominal cross-section range that complies with the provisions of GB / T 3956-2008 Class 2 conductors, the utility model cable can not only carry higher currents and meet the medium-voltage power supply needs of large-scale industrial equipment and high-rise buildings, but also ensure the stability and efficiency of current transmission, reduce overheating and energy loss problems caused by too small a cross-section, and improve the overall operating performance and service life of the cable.

[0027] Furthermore, preferably, the conductor shielding layer has a thickness of 0.7-0.9 mm. This precise conductor shielding layer thickness design effectively isolates the conductor from direct contact with the external environment, reducing electromagnetic interference and signal attenuation. It also enhances the mechanical strength of the cable, protects the conductor from external damage, and ensures the continuity and stability of power transmission.

[0028] Furthermore, the insulation layer is preferably made of 90°C irradiated cross-linked polyolefin material with a 35kV voltage rating, with an insulation thickness of 9.3 to 10.5 mm. The use of high-performance 35kV irradiated cross-linked polyolefin material, combined with optimized insulation thickness, not only significantly improves the cable's heat resistance and insulation performance, but also ensures stable operation in extreme temperature conditions, effectively prevents short circuits and leakage, and enhances the cable's safety and reliability.

[0029] Furthermore, preferably, the thickness of the insulating shielding layer is 0.7 to 0.9 mm. A reasonable thickness of the insulating shielding layer further enhances the electrical performance and mechanical protection of the cable, effectively isolates the direct impact of external factors on the insulating layer, extends the service life of the cable, and improves the stability of the overall system.

[0030] Further preferably, the thickness of the first fireproof layer is 0.8-2.0 mm, and the thickness of the fireproof and oxygen-insulating layer is 1.2-2.0 mm. Through the double-layer fireproof design, namely the fireproof layer and the fireproof and oxygen-insulating layer, each with an appropriate thickness, the cable of the utility model can quickly form an effective barrier in the event of a fire, preventing the spread of fire while reducing the generation of toxic smoke and gas, providing valuable time for personnel evacuation and fire rescue, and greatly improving the fire safety and environmental performance of the cable.

[0031] Furthermore, the thickness of the second fireproof layer is preferably 1.2-2.4 mm. Increasing the thickness of the second fireproof layer further enhances the fireproof isolation capability of the cable, ensuring that the cable structure remains intact even in prolonged combustion or high-temperature environments, effectively protecting the internal conductors and insulation layer from damage, and ensuring the continuous power supply capability of the power system.

[0032] Further preferably, the thickness of the moisture-proof layer is 0.6 mm. The specially designed moisture-proof layer, with its moderate thickness, effectively prevents the intrusion of water and moisture, avoids the insulation performance degradation and corrosion problems of the cable caused by a humid environment, is particularly suitable for applications in special environments such as humid or underwater, and improves the adaptability and durability of the cable.

[0033] Further preferably, the thickness of the sheath layer is 2.2 to 4.0 mm. As the outermost protective layer of the cable, the rational design of the thickness of the sheath layer not only enhances the mechanical strength and wear resistance of the cable, but also provides good UV resistance and aging resistance, ensuring the long-term stable operation of the cable in various harsh environments, extending its service life and reducing maintenance costs.

[0034] In summary, through the fine optimization of the structure and material thickness of each layer, the cable of the utility model not only meets the high requirements of medium-voltage power supply, but also achieves comprehensive improvement in fire protection, moisture resistance, insulation, mechanical protection, etc., providing a solid guarantee for the safe and reliable operation of the power system.

[0035] In summary, the utility model has the advantages of simple structure, small outer diameter, round appearance, soft use, environmental protection and saving, waterproof and moisture-proof, and the cable has good fire resistance, physical and mechanical properties, electrical properties, environmental protection and safety, halogen-free, low smoke, high flame retardant, waterproof and moisture-proof, etc.

[0036] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable, comprising a conductor, characterized in that: A conductor shielding layer is provided outside the conductor, and the conductor shielding layer is composed of a semi-conductive shielding layer and a non-magnetic metal tape shielding composite. An insulating layer made of 90°C irradiated cross-linked polyolefin material is provided outside the conductor shielding layer. A composite insulating shielding layer composed of a cross-linked semi-conductive material and a non-magnetic metal tape is provided outside the insulating shielding layer. A first fireproof layer is provided outside the insulating shielding layer, and the first fireproof layer is wrapped with multiple layers of ceramic mica tape; a fireproof and oxygen-isolating layer of highly flame-retardant, low-smoke, halogen-free ceramic fire-resistant polyolefin is provided outside the first fireproof layer, and a second fireproof layer is provided outside the fireproof and oxygen-isolating layer, and the second fireproof layer is wrapped with multiple layers of non-combustible ceramic silicone tape; a moisture-proof shielding layer is provided outside the second fireproof layer, and the moisture-proof shielding layer is wrapped with overlapping aluminum-plastic composite tapes; a sheath layer of 90°C irradiated cross-linked, halogen-free, low-smoke, flame-retardant B1 grade polyolefin material is provided outside the moisture-proof shielding layer.

2. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The nominal cross-section of the conductor is 50 to 1600 mm 2 .

3. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The conductor shielding layer has a thickness of 0.7-0.9 mm.

4. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The insulating layer is made of 90° C. radiation cross-linked polyolefin material with a voltage level of 35 kV, and the insulating thickness is 9.3 to 10.5 mm.

5. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the insulating shielding layer is 0.7-0.9 mm.

6. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the fireproof layer is 0.8-2.0 mm.

7. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the fireproof and oxygen-isolating layer is 1.2-2.0 mm.

8. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the second fireproof layer is 1.2-2.4 mm.

9. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the moisture-proof layer is 0.6 mm.

10. The moisture-proof, halogen-free, low-smoke, flame-retardant, Class B1, fire-resistant medium-voltage power cable according to claim 1, characterized in that: The thickness of the sheath layer is 2.2-4.0 mm.

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