Isolated medium-voltage fire-resistant cable

Abstract

The utility model relates to an isolation type medium-voltage fire-resistant cable, which comprises a temperature measurement optical cable, an insulation wire core group, a liquid cooling pipe, a wrapping layer, a fireproof layer and an outer sheath layer, the liquid cooling pipe is arranged in the gap between the two adjacent insulated wire cores in the insulated wire core group and the wrapping layer, so that when the temperature of the medium-voltage fire-resistant cable exceeds 45 DEG C, the medium-voltage fire-resistant cable can be cooled through the liquid cooling pipe, and the transmission efficiency of the medium-voltage fire-resistant cable is guaranteed; when a fire disaster occurs, the cable can be cooled through the liquid cooling pipe, and meanwhile, a certain fire extinguishing effect is also achieved, so that more time is provided for fire-fighting escape; the fireproof layer and the fireproof layer are made of ceramic polyolefin materials, when a fire disaster occurs and a certain temperature is reached, a layer of compact ceramic armor body can be formed, and the liquid cooling pipe is matched to play a role in heat insulation and cooling, so that the medium-voltage fire-resistant cable is effectively protected, and the service life of the medium-voltage fire-resistant cable is prolonged. And the insulating performance of the insulating wire cores is prevented from being damaged due to over-high temperature.

Description

Technical Field

[0001] The utility model relates to the field of medium-voltage fire-resistant cables, and particularly to an isolated medium-voltage fire-resistant cable. Background Art

[0002] The statements herein only provide background art related to the utility model and do not necessarily constitute prior art.

[0003] With the rapid development of the economy, the society's safety requirements for the power grid protection system are also continuously increasing. As the transmission cables in high-rise and large-scale high-rise buildings, the laying quantity and workload of medium-voltage fire-resistant cables are huge, making the performance requirements for medium-voltage fire-resistant cables more and more stringent.

[0004] The fire resistance of medium-voltage fire-resistant cables has always been a target of much attention and research. Fire-resistant cables are mostly used in the power supply circuits of emergency power supplies and are required to work properly during a fire. However, when ordinary medium-voltage fire-resistant cables are directly burned by flames, only the fire-resistant materials in the insulation layer are relied on for heat insulation and flame retardancy, which causes the insulation layer to be quickly burned through, making the medium-voltage fire-resistant cable unable to operate and be used, and ultimately resulting in the failure of the entire power distribution system. At the same time, due to the limited flame retardancy ability of medium-voltage fire-resistant cables, they can only supply power within a limited time after a fire and cannot provide enough time for escape. Summary of the Utility Model

[0005] The technical problem to be solved by the utility model is to provide an isolated medium-voltage fire-resistant cable. The liquid cooling pipes provided can cool down the medium-voltage fire-resistant cable and can play a certain role in heat resistance and fire extinguishing during a fire. At the same time, the fire-resistant layer and the fireproof layer adopt a ceramized polyolefin material, which will form a ceramized hard shell structure when reaching a certain temperature, thereby insulating and cooling the medium-voltage fire-resistant cable and improving the fire resistance performance of the medium-voltage fire-resistant cable.

[0006] The purpose of the utility model is to provide an isolated medium-voltage fire-resistant cable, which includes a temperature-measuring optical cable, an insulated conductor core group, liquid cooling pipes, a wrapping layer, a fireproof layer and an outer sheath layer. The insulated conductor core group includes three insulated conductor cores, and the three insulated conductor cores are arranged around the temperature-measuring optical cable, surrounding the temperature-measuring optical cable in the middle. The temperature-measuring optical cable, the insulated conductor core group and the liquid cooling pipes form the cable core of the medium-voltage fire-resistant cable. The outer side of the cable core is sequentially wrapped with a wrapping layer, a fireproof layer and an outer sheath layer. A gap is formed between adjacent two insulated conductor cores and the wrapping layer, and the liquid cooling pipes are arranged in the gap.

[0007] As a further technical solution, a copper conductor is arranged at the central position of the insulated conductor core, and the outer side of the copper conductor is sequentially wrapped with a conductor semi-conductive shielding layer, an insulating layer, an insulating semi-conductive shielding layer, a metal tape shielding layer and a fire-resistant layer.

[0008] As a further technical solution, the conductor semi-conductive shielding layer is a cross-linked semi-conductive shielding material, the insulating layer is a peroxide cross-linked polyethylene insulating material, and the insulating semi-conductive shielding layer is a cross-linked peelable semi-conductive shielding material.

[0009] As a further technical solution, the metal tape shielding layer is a copper tape shielding winding structure.

[0010] As a further technical solution, the liquid cooling tube is of a fan-shaped structure and is made of PP material.

[0011] As a further technical solution, the temperature measurement optical cable is sequentially provided with a temperature measurement optical fiber, a stainless steel spiral steel pipe, a fiber layer, a stainless steel wire braided layer, and an outer sheath from inside to outside.

[0012] As a further technical solution, the copper conductor is a Class 2 compacted copper conductor and is of a compacted circular structure.

[0013] As a further technical solution, the fireproof layer and the fire-resistant layer are made of ceramized polyolefin material, and the fire-resistant layer is of an extruded structure.

[0014] As a further technical solution, the wrapping layer uses a low-smoke and halogen-free flame-retardant tape.

[0015] As a further technical solution, the outer sheath layer uses a low-smoke and halogen-free flame-retardant polyolefin sheath material.

[0016] Advantages of the above one or more technical solutions:

[0017] (1) In this embodiment, by arranging the liquid cooling tube in the gap formed by two adjacent insulating wire cores and the wrapping layer, when the temperature of the medium-voltage fire-resistant cable is higher than 45 °C, the liquid cooling tube can cool down the medium-voltage fire-resistant cable to ensure the transmission efficiency of the medium-voltage fire-resistant cable; when a fire occurs, the liquid cooling tube can also cool down the cable, and at the same time, it also plays a certain role in extinguishing the fire, thereby providing more time for fire escape.

[0018] (2) In this embodiment, the ceramized polyolefin material is used in the fireproof layer and the fire-resistant layer. When a fire occurs and reaches a certain temperature, a dense ceramic-like armor can be formed, which cooperates with the liquid cooling tube to play a role in heat insulation and cooling, thereby effectively protecting the medium-voltage fire-resistant cable and preventing the insulating wire core from damaging its insulation performance due to excessive temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings forming a part of this application are used to provide a further understanding of this application. For ease of understanding, the proportions between the structures of various parts have been adjusted. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation to this application.

[0020] Figure 1 It is the internal structure diagram of an isolated medium-voltage fire-resistant cable of the present utility model.

[0021] Figure 2 It is the internal structure diagram of the temperature-measuring optical cable in an isolated medium-voltage fire-resistant cable of the present utility model.

[0022] Among them, 1. Temperature-measuring optical cable, 2. Insulated conductor group, 3. Insulated conductor, 4. Liquid cooling pipe, 5. Wrapping layer, 6. Fireproof layer, 7. Outer sheath layer, 8. Copper conductor, 9. Conductor semiconductive shielding layer, 10. Insulation layer, 11. Insulation semiconductive shielding layer, 12. Metal tape shielding layer, 13. Fire-resistant layer, 14. Temperature-measuring optical fiber, 15. Stainless steel spiral steel pipe, 16. Fiber layer, 17. Stainless steel wire braided layer, 18. Outer sheath. Specific embodiments

[0023] The following combines the attached Figure 1-2 drawings to clearly and completely describe the technical solutions in the embodiments of the present utility model.

[0024] Embodiment 1

[0025] Referring to Figure 1 a kind of isolated medium-voltage fire-resistant cable includes a temperature-measuring optical cable 1, an insulated conductor group 2, a liquid cooling pipe 4, a wrapping layer 5, a fireproof layer 6 and an outer sheath layer 7.

[0026] Referring to Figure 2 the temperature-measuring optical cable 1 is jointly composed of a tight-sheath ATF-100 type temperature-measuring optical fiber 14, a stainless steel spiral steel pipe 15, a fiber layer 16 made of kevlar material, a stainless steel wire braided layer 17 and an outer sheath 18. The temperature-measuring optical fiber 14 is coated by the stainless steel spiral steel pipe 15, and the temperature-measuring optical cable 1 can monitor the temperature of the medium-voltage fire-resistant cable.

[0027] Specifically, the tight-buffered ATF-100 temperature-measuring optical fiber 14 in the temperature-measuring optical cable 1 is located at the center of the optical cable, has excellent heat conduction characteristics, and can meet the real-time transmission of information when the temperature of the optical cable changes; the stainless steel spiral steel pipe 15 is located between the tight-buffered ATF-100 temperature-measuring optical fiber 14 and the kevlar fiber layer 16, and has the functions of protecting the inner-layer optical fiber and enhancing the compressive mechanical properties; the kevlar fiber layer 16 is located between the stainless steel spiral steel pipe 15 and the stainless steel wire braid layer 17, and has the functions of enhancing the physical strength of the optical cable, improving its thermal stability, reducing erosion and wear, etc.; and the stainless steel wire braid layer 17 is located between the kevlar fiber layer 16 and the outer sheath 18, and has the functions of mechanical protection, bearing the longitudinal breaking force and magnetic field shielding, etc., to ensure the stable operation of the temperature-measuring optical cable 1 in various environments and the accuracy of the signal; the outer sheath 18 is located on the outermost side of the optical cable, and the outer sheath 18 is made of a low-smoke, halogen-free flame-retardant polyolefin sheath material, and has the functions of flame retardancy and protecting the cable core from erosion, etc.

[0028] Refer to Figure 1 , the temperature-measuring optical cable 1 is arranged at the center of the medium-voltage fire-resistant cable; and the insulated conductor group 2 includes three insulated conductors 3, and the three insulated conductors 3 in the insulated conductor group 2 are arranged around the temperature-measuring optical cable 1, surrounding the temperature-measuring optical cable 1 in the middle. In this embodiment, the number of the insulated conductors 3 is 3, and the 3 insulated conductors 3 are arranged around the temperature-measuring optical cable 1, and at the same time, the insulated conductors 3 can fix the temperature-measuring optical cable 1 at the central position. The number of the insulated conductors 3 here can meet the power transmission requirements of the medium-voltage fire-resistant cable, and at the same time, the temperature-measuring optical cable 1 can evenly monitor the temperature around the fire-resistant cable at the central position; the monitoring referred to here is the function possessed by the ATF-100 temperature-measuring optical fiber 14 in the temperature-measuring optical cable 1 itself.

[0029] In this embodiment, a liquid-cooling pipe 4 is also arranged in the medium-voltage fire-resistant cable, and the temperature-measuring optical cable 1, the insulated conductor group 2 and the liquid-cooling pipe 4 form the cable core of the medium-voltage fire-resistant cable. Specifically, the liquid-cooling pipe 4 is made of PP material. Based on the excellent impact resistance and heat resistance of the PP material itself, setting it inside the cable can adapt to the bending of the cable, avoid the breakage of the liquid-cooling pipe 4, and at the same time can improve the fire resistance of the cable itself.

[0030] When the temperature of the medium-voltage fire-resistant cable is higher than 45°C, coolant or normal temperature water can be transported through the liquid cooling pipe 4, and the cable can be cooled by absorbing heat, thereby reducing the temperature of the cable, so as to ensure the current-carrying capacity transmission efficiency of the medium-voltage fire-resistant cable. When a fire occurs but does not cause damage to the liquid cooling pipe 4, the same method can be used for cooling, so as to delay the damage of the fire to the medium-voltage fire-resistant cable; when the liquid cooling pipe 4 is damaged, the internal coolant or normal temperature water can extinguish the fire around the cable, play a role in controlling the fire, delay the damage of the fire to the fire-resistant cable, and thus provide more time for fire escape.

[0031] In addition, the liquid cooling pipe 4 can cooperate with the temperature-measuring optical cable 1 at the same time, so as to accurately judge the time for the liquid cooling pipe 4 to transport coolant or normal temperature water; and the liquid cooling pipe 4 can be connected to the water supply system set in scenarios such as high-rise and large high-rise buildings to provide normal temperature water and so on.

[0032] A wrapping layer 5, a fireproof layer 6 and an outer sheath layer 7 are wrapped outside the cable core. Specifically, the wrapping layer 5 uses a low-smoke and halogen-free flame-retardant tape to wrap the entire cable core, improving the fire-resistant performance of the cable core. The fireproof layer 6 uses a ceramized polyolefin material, which has fireproof and heat-insulating functions; when burning or reaching a certain temperature, it can form a dense ceramic-like armor, and fully play the role of heat insulation and cooling by absorbing heat, so as to reduce the heat received by the cable core, thereby protecting the internal structure of the cable. At the same time, the outer sheath layer 7 is made of a low-smoke and halogen-free flame-retardant polyolefin sheath material; in this embodiment, it is specifically a 90°C low-smoke and halogen-free flame-retardant polyolefin sheath material. This material does not emit halogen acid gas when burning, and the release amount of toxic and corrosive gases is extremely small, and the generated smoke concentration is relatively low, meeting technical indicators such as low-smoke, halogen-free, low-toxicity and light transmittance; and this material also has the characteristic that it is not easy to fall off when encountering fire and forming a shell.

[0033] In addition, the structure of the liquid cooling pipe 4 is a fan-shaped structure, and it is arranged in the gap formed between two adjacent insulating wire cores 3 and the wrapping layer 5. Through the above settings, the fan-shaped structure of the liquid cooling pipe 4 just matches the spatial structure between the two insulating wire cores 3 and the wrapping layer 5, thereby expanding the occupied area of the liquid cooling pipe 4, improving the cooling performance of the liquid cooling pipe 4, and also being able to support the medium-voltage heat-resistant cable.

[0034] At the same time, the liquid cooling pipe 4 can isolate the insulating wire core 3 and the wrapping layer 5 to a certain extent. When the external temperature is too high or a fire occurs, the liquid cooling pipe 4 plays a certain isolation role, thereby effectively protecting the insulating wire core 3.

[0035] In this embodiment, a copper conductor 8 is arranged at the center position of the insulating wire core 3, and a conductor semi-conductive shielding layer 9, an insulating layer 10, an insulating semi-conductive shielding layer 11, a metal tape shielding layer 12 and a fire-resistant layer 13 are sequentially wrapped outside the copper conductor 8.

[0036] Specifically, the copper conductor 8 is a Class 2 compacted copper conductor, which forms a circular structure by means of stranding and compacting, and is used for power transmission of medium-voltage fire-resistant cables. By adjusting the number of the insulated cores 3, the performance requirements of the medium-voltage fire-resistant cables are met. At the same time, the conductor semi-conductive shielding layer 9, the insulating layer 10, and the insulating semi-conductive shielding layer 11 are formed by three-layer co-extrusion technology. The conductor semi-conductive shielding layer 9 is a cross-linked semi-conductive shielding material, the insulating layer 10 is a peroxide cross-linked polyethylene insulating material, and the insulating semi-conductive shielding layer 11 is a cross-linked peelable semi-conductive shielding material. Through the above settings, the insulation eccentricity is controlled within a range of less than 8%, ensuring the electrical and mechanical properties of the insulated core 3.

[0037] The metal tape shielding layer 12 is a copper tape shielding winding structure, and the copper tape overlapping rate is not less than 15%, further improving the anti-interference ability of the insulated core 3. At the same time, the fire-resistant layer 13 is made of ceramized polyolefin material and is an extrusion structure, which is the same as the material used for the fireproof layer 6 and plays the same role.

[0038] Although the specific implementation manners of the present invention are described above in conjunction with the accompanying drawings, it is not a limitation to the protection scope of the present invention. Those skilled in the art should understand that based on the technical solutions of the present invention, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present invention.

Claims

1. An isolated medium voltage fire-resistant cable, characterized in that: It includes a temperature measuring optical cable, an insulating core group, a liquid cooling tube, a wrapping layer, a fireproof layer and an outer sheath layer, wherein the insulating core group includes three insulating cores, and the three insulating cores are arranged around the temperature measuring optical cable to surround the temperature measuring optical cable in the middle; the temperature measuring optical cable, the insulating core group and the liquid cooling tube constitute the cable core of the medium-voltage fire-resistant cable, and the outer side of the cable core is wrapped with a wrapping layer, a fireproof layer and an outer sheath layer in sequence; a gap is formed between two adjacent insulating cores and the wrapping layer, and the liquid cooling tube is arranged in the gap.

2. An isolated medium voltage fire-resistant cable according to claim 1, characterized in that: A copper conductor is arranged at the center of the insulating core, and the outer side of the copper conductor is wrapped with a conductor semi-conductive shielding layer, an insulating layer, an insulating semi-conductive shielding layer, a metal tape shielding layer and a fire-resistant layer in sequence.

3. An isolated medium voltage fire-resistant cable as claimed in claim 2, characterized in that: The conductor semiconductive shielding layer is a cross-linked semiconductive shielding material, the insulating layer is a peroxide cross-linked polyethylene insulating material, and the insulating semiconductive shielding layer is a cross-linked strippable semiconductive shielding material.

4. An isolated medium voltage fire-resistant cable as claimed in claim 2, characterized in that: The metal tape shielding layer is a copper tape shielding wrapping structure.

5. An isolated medium voltage fire-resistant cable as claimed in claim 1, characterized in that: The liquid cooling tube is a fan-shaped structure and is made of PP material.

6. An isolated medium voltage fire-resistant cable as claimed in claim 1, characterized in that: The temperature measuring optical cable is provided with a temperature measuring optical fiber, a stainless steel spiral steel pipe, a fiber layer, a stainless steel wire braided layer and an outer sheath in sequence from the inside to the outside.

7. An isolated medium voltage fire-resistant cable as claimed in claim 2, characterized in that: The copper conductor is a second-class compacted copper conductor and has a compacted circular structure.

8. An isolated medium voltage fire-resistant cable as claimed in claim 1, characterized in that: The fireproof layer and the fire-resistant layer are made of ceramic polyolefin material, and the fire-resistant layer is an extruded structure.

9. An isolated medium voltage fire-resistant cable according to claim 1, characterized in that: The wrapping layer adopts low-smoke halogen-free flame-retardant wrapping tape.

10. An isolated medium voltage fire-resistant cable according to claim 1, characterized in that: The outer sheath layer is made of low-smoke, halogen-free, flame-retardant polyolefin sheath material.

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