Medium-voltage 35kV high-flame-retardant B1-level cable for rail transit

Abstract

The utility model belongs to the field of rail transit medium-voltage cables, and provides a rail transit medium-voltage 35kV high-flame-retardant B1-level cable, which comprises an electric unit and an insulating unit, and the insulating unit wraps the electric unit in the center of a cable core; a semi-conductive water-blocking tape wrapping layer is wrapped outside the insulation unit, and the semi-conductive water-blocking tape wrapping layer is arranged between the insulation unit and the copper wire sparse winding shielding layer; the copper wire sparsely-wound shielding layer adopts a copper wire shielding and outer copper strip sparsely-wound structure; the copper wire sparse winding shielding layer is located between the semi-conductive water-blocking tape wrapping layer and the heat insulation layer; the heat insulation layer is formed by overlapping and wrapping ceramic silicone rubber composite tapes, and when the cable is burnt, a ceramic hard shell structure is formed. The cable provided by the utility model has the advantages of strong overload capacity, radial water resistance, rat resistance, ultraviolet light resistance, B1-class flame retardance and the like, and can fully meet the harsh use working conditions of indoor and outdoor scenes of rail transit.

Description

Technical Field

[0001] The utility model belongs to the field of medium-voltage cables for rail transit, and in particular relates to a medium-voltage 35kV high flame-retardant B1-level cable for rail transit. Background Art

[0002] The statements in this section merely provide background technical information related to the present invention and do not necessarily constitute prior art.

[0003] With the rapid development of the economy, my country's high-speed rail and subway rail transit are constantly expanding, underground facilities are constantly expanding and improving, and more and more medium-voltage cables are being used in rail transit power distribution systems, and cable laying is becoming more and more intensive. Fires caused by aging cable sheaths and unstable cable performance also occur frequently. At the same time, once a fire occurs, the safe and reliable operation of rail transit equipment also requires the protection of wires and cables. Therefore, how to reduce the probability of fire and ensure the normal operation of the circuit within a period of time after the fire occurs, puts forward very high requirements on the flame retardant performance of medium-voltage power cables.

[0004] The selection of wires and cables in rail transit not only affects the normal use of electrical equipment and the cost of the project, but more importantly, it affects the safety of electrical use and even the personal safety of people in transportation facilities. The selection of highly flame-retardant and fire-resistant power cables is important for the safe operation of rail transit facilities. However, the ordinary flame-retardant cables on the market currently only require the carbonization height of bundled combustion, which is quite different from the actual scene of fire. Utility Model Content

[0005] In order to solve the above problems, the utility model proposes a rail transit medium voltage 35kV high flame retardant B1 grade cable, the cable electrical unit conductor structure adopts 2 types of compacted copper conductors, the insulation layer adopts three-layer co-extrusion, the conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, the insulation layer adopts 35kV peroxide cross-linked polyethylene insulation material, the insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material, the outer periphery of the insulating core is, from the inside to the outside, a semi-conductive water-repellent tape wrapping layer, a copper wire sparsely wound shielding layer, a heat insulation layer, a corrugated aluminum sheath layer, a fireproof layer, a flame-retardant tape wrapping layer and an outer sheath layer; rail transit medium voltage 35kV B1 grade high flame retardant cable is mainly used as connecting cable between power transmission and components of rail power transmission and distribution system. This cable is suitable for 35kV power grid system. The working environment temperature meets the requirements of -40℃~+90℃ and the maximum temperature of short-circuit conductor is 250℃. The underground cables meet the requirements of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof radial waterproof and other properties. The above-ground cables meet the requirements of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof and UV-proof and other properties.

[0006] According to some embodiments, the utility model provides a rail transit medium voltage 35kV high flame retardant B1 class cable, which adopts the following technical solution:

[0007] A rail transit medium-voltage high flame-retardant B1-level cable, comprising an electrical unit and an insulating unit, wherein the insulating unit wraps the electrical unit around the center of the cable core;

[0008] The insulating unit is wrapped with a semi-conductive water-tight tape wrapping layer, and the semi-conductive water-tight tape wrapping layer is between the insulating unit and the copper wire sparsely wound shielding layer;

[0009] The copper wire sparsely wound shielding layer adopts a copper wire shielding plus an outer copper tape sparsely wound structure; the copper wire sparsely wound shielding layer is located between the semi-conductive resistance water tape wrapping layer and the thermal insulation layer;

[0010] The heat insulation layer is wrapped with ceramic silicone rubber composite tape in an overlapping manner, and a ceramic hard shell structure is formed when the cable burns.

[0011] Furthermore, the electrical unit adopts Class 2 compressed circular copper conductors, the copper conductors are formed by twisting and compressing a plurality of copper monofilaments, and the electrical unit is used for power transmission of the cable.

[0012] Furthermore, the insulating unit is extruded by three-layer co-extrusion, and includes a conductor semi-conductive shielding layer, an insulating layer and an insulating semi-conductive shielding layer from the inside to the outside.

[0013] Furthermore, the heat insulation layer is located between the corrugated aluminum sheath layer and the copper wire sparsely wound shielding layer, and the corrugated aluminum sheath layer adopts an argon arc welding corrugated aluminum sheath.

[0014] Furthermore, the corrugated aluminum sheath is located between the heat insulation layer and the fireproof layer.

[0015] Furthermore, the fireproof layer is made of a mixture of materials such as magnesium hydroxide, and the fireproof layer is located between the corrugated aluminum sheath and the flame-retardant tape wrapping layer.

[0016] Furthermore, the flame retardant tape wrapping layer adopts low-smoke halogen-free flame retardant tape to cover the fireproof layer to prevent dripping from being generated during the combustion process.

[0017] Furthermore, the flame retardant tape is wrapped around the sheath with an outer sheath layer, the outer sheath layer is made of B1 grade low heat release low smoke halogen-free flame retardant polyolefin sheath material, and the outer sheath layer is located at the outermost layer of the cable.

[0018] Furthermore, the conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, and the insulating layer adopts 35kV peroxide cross-linked polyethylene insulating material.

[0019] Furthermore, the insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material.

[0020] Compared with the prior art, the beneficial effects of the utility model are:

[0021] The utility model cable adds a fireproof layer and a heat-insulating layer structure to the product structure. The two-layer structure can form a dense ceramic armor when burning or reaching a certain temperature, which fully plays the role of heat insulation and cooling. At the same time, the structure will form a dense armor when burning or reaching a certain high temperature. It has the characteristics of self-extinguishing and no flame extension, no melting, no dripping, and no falling off when burning horizontally. The higher the temperature and the longer the time, the harder the armor after burning. The residue is inorganic, which fully plays the role of heat insulation and cooling, and can ensure that the insulation core will not be damaged due to excessive temperature, reducing or losing insulation performance. The cable also meets the characteristics of flame retardancy, fire blocking, heat insulation, heat dissipation, and cooling, ensuring the integrity of the insulation core structure inside the cable, and can pass the medium-voltage flame retardancy and fire resistance test, which can fully meet the harsh operating conditions of indoor and outdoor scenes of rail transit.

[0022] The high flame retardant B1-level cable mentioned in the utility model not only meets the carbonization height of bundled combustion of ordinary flame retardant cables, but also meets the requirements of low heat release, smoke production characteristics, low toxicity and other indicators under the actual fire situation. This product is suitable for public places and special places with high fire protection requirements such as rail transit and tunnels. It can not only meet the normal use of buildings but also ensure the safety of people and property, and also meet the principles of building electrical energy saving and reasonable cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0024] Figure 1 This is a structural diagram of a rail transit medium voltage 35kV high flame retardant B1 grade cable of the utility model;

[0025] In the figure, copper conductor 1, conductor semi-conductive shielding layer 2, insulating layer 3, insulating semi-conductive shielding layer 4, semiconductor water-blocking tape wrapping layer 5, copper wire sparsely wound shielding layer 6, thermal insulation layer 7, corrugated aluminum sheath layer 8, fireproof layer 9, flame retardant tape wrapping layer 10, and outer sheath layer 11. DETAILED DESCRIPTION

[0026] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0027] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0028] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the utility model. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0029] In the present utility model, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present utility model can be determined according to specific circumstances, and they cannot be understood as limitations on the present utility model.

[0030] Embodiment 1

[0031] This embodiment provides a rail transit medium voltage 35kV high flame retardant B1 class cable, including an electrical unit and an insulating unit, wherein the insulating unit wraps the electrical unit around the center of the cable core;

[0032] The insulating unit is wrapped with a semi-conductive water-tight tape wrapping layer, and the semi-conductive water-tight tape wrapping layer is between the insulating unit and the copper wire sparsely wound shielding layer;

[0033] The copper wire sparsely wound shielding layer adopts a copper wire shielding plus an outer copper tape sparsely wound structure; the copper wire sparsely wound shielding layer is located between the semi-conductive resistance water tape wrapping layer and the thermal insulation layer;

[0034] The heat insulation layer is wrapped with ceramic silicone rubber composite tape in an overlapping manner, and a ceramic hard shell structure is formed when the cable burns.

[0035] The electric unit copper conductor is formed by twisting and pressing a plurality of copper monofilaments, and the electric unit is used for power transmission of the cable.

[0036] The insulating unit is extruded by three-layer co-extrusion, and includes a conductor semi-conductive shielding layer, an insulating layer and an insulating semi-conductive shielding layer from the inside to the outside.

[0037] The heat insulation layer is located between the corrugated aluminum sheath layer and the copper wire sparsely wound shielding layer. The corrugated aluminum sheath layer adopts an argon arc welding corrugated aluminum sheath. The corrugated aluminum sheath is located between the heat insulation layer and the fireproof layer.

[0038] The fireproof layer is made of a mixture of materials such as magnesium hydroxide, and is located between the corrugated aluminum sheath and the flame-retardant tape wrapping layer; the flame-retardant tape wrapping layer is made of low-smoke halogen-free flame-retardant tape, which covers the fireproof layer to prevent dripping during combustion.

[0039] The flame retardant tape wrapping layer is coated with an outer sheath layer, the outer sheath layer is made of B1 grade low heat release low smoke halogen-free flame retardant polyolefin sheath material, and the outer sheath layer is located at the outermost layer of the cable.

[0040] The conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, the insulating layer adopts 35kV peroxide cross-linked polyethylene insulating material, and the insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material.

[0041] The conductor structure of the cable electrical unit adopts Class 2 compacted round copper conductor, which is made of multiple copper monofilaments twisted and compacted. The insulation unit adopts three-layer co-extrusion. The conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, and the insulation layer adopts 35kV peroxide cross-linked polyethylene insulation material. The insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material. The outer periphery of the insulating core is, from the inside to the outside, a semi-conductive water-repellent tape wrapping layer, a copper wire sparsely wound shielding layer, a heat insulation layer, a corrugated aluminum sheath layer, a fireproof layer, a flame-retardant tape wrapping layer and an outer sheath layer; Rail transit medium voltage 35kV B1 grade high flame retardant cable is mainly used as connecting cable between power transmission and components of rail power transmission and distribution system. This cable is suitable for 35kV power grid system. The working environment temperature meets the requirements of -40℃~+90℃ and the maximum temperature of short-circuit conductor is 250℃. The underground cables meet the requirements of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof radial waterproof and other properties. The above-ground cables meet the requirements of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof and UV-proof and other properties.

[0042] like Figure 1 As shown, the cable is sequentially provided with an outer sheath layer 11, a flame retardant tape wrapping layer 10, a fireproof layer 9, a corrugated aluminum sheath layer 8, a heat insulation layer 7, a copper wire sparsely wound shielding layer 6, a semiconductor water-blocking tape wrapping layer 5, an insulating semi-conductive shielding layer 4, an insulating layer 3, a conductor semi-conductive shielding layer 2, and a copper conductor 1 is located at the center of the cable core;

[0043] The electrical unit is in the center of the cable core, that is, copper conductor 1. The electrical unit transmits energy for the entire power system. The conductor adopts the second type of compacted circular copper conductor structure. The conductor is required to be twisted regularly and compacted by a compacting die after twisting. The compaction coefficient is not less than 0.91, and the maximum DC resistance of the conductor at 20°C complies with the provisions of GB / T 3956-2008.

[0044] The electric unit is used for power transmission of the cable. This layer of the electric unit is the key structure for the electrical and power performance of the cable. The overall temperature resistance level of the electric unit can reach 90°C, meeting the short-term overload maximum temperature of 250°C.

[0045] The insulation unit uses three-layer co-extrusion. The conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, the insulation layer adopts 35kV peroxide cross-linked polyethylene insulation material, and the insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material. The insulation eccentricity is controlled to <8%, ensuring the superior electrical and mechanical properties of the insulating material.

[0046] The semi-conductor water-wound sheath is placed between the insulating unit and the copper wire sparsely wound shielding layer to prevent the copper wire shielding single wire from being embedded in the insulating core, thereby protecting the insulating core from damage.

[0047] The copper wire sparsely wound shielding layer adopts a copper wire shielding plus an outer copper tape sparsely wound structure. The metal shielding cross-sectional area meets the system short-circuit current requirement of 1000A / 3S. At the same time, the copper wire shielding resistance meets the maximum DC resistance of conductors with the same conductor cross-section and 20℃ in GB / T 3956-2008.

[0048] The thermal insulation layer is made of ceramic silicone rubber composite tape wrapped in overlapping layers. When the cable burns, a ceramic hard shell structure can be formed to protect the insulating core from heat damage.

[0049] The corrugated aluminum sheath layer adopts argon arc welding corrugated aluminum sheath, which meets the air tightness test, has radial waterproof, rat and ant proof properties, and protects the cable core from some mechanical damage caused by external forces.

[0050] The fireproof layer is made of a mixture of materials such as magnesium hydroxide, which has fireproof and heat-insulating functions. After burning, it can form a solid shell, reducing the heat of the cable core to protect the internal structure.

[0051] The flame retardant tape wrapping layer uses low-smoke halogen-free flame retardant tape to cover the fireproof layer to prevent dripping during the combustion process.

[0052] The outer sheath layer adopts B1 grade low heat release, low smoke, halogen-free and highly flame-retardant polyolefin sheath material. When this material burns, it releases no halogen acid gas, and the release of toxic and corrosive gases is extremely small. The smoke concentration generated is extremely low, which meets the light transmittance requirements. At the same time, it also has the characteristic of not easily falling off when encountering fire, which has a good heat insulation and cooling effect, meets the B1 grade low toxicity and low heat release combustion performance test requirements, and can meet the long-term stable operation of the cable in complex installation environments.

[0053] The utility model discloses a rail transit medium voltage 35kV high flame retardant B1 grade cable, comprising an electric unit and an insulating unit, wherein the electric unit is wrapped and located at the center of the cable core, the insulating unit is extruded by three-layer co-extrusion, the conductor semi-conductive shielding layer adopts a 35kV cross-linked semi-conductive shielding material, the insulating layer adopts a 35kV peroxide cross-linked polyethylene insulating material, the insulating semi-conductive shielding layer adopts a 35kV cross-linked strippable semi-conductive shielding material, and the outer periphery of the insulating core is sequentially provided with a semi-conductive water-wound wrapping layer, a copper wire sparsely wound shielding layer, a heat insulation layer, a corrugated aluminum sheath layer, a fireproof layer, a flame-retardant wrapping tape wrapping layer and an outer sheath layer from the inside to the outside; the rail transit medium voltage 35kV B1 grade high flame retardant cable is mainly used as connecting cable between power transmission and components of rail power transmission and distribution system. This cable is suitable for 35kV power grid system. The working environment temperature meets -40℃~+90℃, and the maximum temperature of short-circuit conductor is 250℃. The underground cable meets the properties of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof radial waterproof, etc. The ground cable meets the properties of low smoke and halogen-free, B1 type low toxicity and low heat release, rodent-proof and UV-proof, etc.

[0054] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

[0055] Although the above describes the specific implementation methods of the utility model in combination with the accompanying drawings, it is not intended to limit the scope of protection of the utility model. Technical personnel in the relevant field should understand that on the basis of the technical solution of the utility model, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the utility model.

Claims

1. A medium voltage 35kV high flame retardant B1 grade cable for rail transit, characterized in that: It comprises an electric unit and an insulating unit, wherein the insulating unit wraps the electric unit around the center of the cable core; The insulating unit is wrapped with a semi-conductive water-tight tape wrapping layer, and the semi-conductive water-tight tape wrapping layer is between the insulating unit and the copper wire sparsely wound shielding layer; The copper wire sparse winding shielding layer adopts a copper wire shielding plus an outer copper tape sparse winding structure; the copper wire sparse winding shielding layer is located between the semi-conductive resistance water tape wrapping layer and the thermal insulation layer; The heat insulation layer is wrapped with ceramic silicone rubber composite tape in an overlapping manner, and a ceramic hard shell structure is formed when the cable burns.

2. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 1, characterized in that: The electrical unit adopts Class 2 compressed round copper conductors, which are formed by twisting and compressing a plurality of copper monofilaments, and is used for power transmission of the cable.

3. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 1, characterized in that: The insulating unit is extruded by three-layer co-extrusion, and includes a conductor semi-conductive shielding layer, an insulating layer and an insulating semi-conductive shielding layer from the inside to the outside.

4. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 1, characterized in that: The heat insulation layer is located between the corrugated aluminum sheath layer and the copper wire sparsely wound shielding layer, and the corrugated aluminum sheath layer adopts an argon arc welding corrugated aluminum sheath.

5. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 4, characterized in that: The corrugated aluminum sheath is located between the heat insulation layer and the fireproof layer.

6. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 5, characterized in that: The fireproof layer is located between the corrugated aluminum sheath and the flame-retardant tape wrapping layer. The flame-retardant tape wrapping layer adopts low-smoke halogen-free flame-retardant tape to cover the fireproof layer to prevent dripping from being generated during the combustion process.

7. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 6, characterized in that: The flame retardant tape wrapping layer is coated with an outer sheath layer, the outer sheath layer is made of B1 grade low heat release low smoke halogen-free flame retardant polyolefin sheath material, and the outer sheath layer is located at the outermost layer of the cable.

8. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 3, characterized in that: The conductor semi-conductive shielding layer adopts 35kV cross-linked semi-conductive shielding material, and the insulating layer adopts 35kV peroxide cross-linked polyethylene insulating material.

9. A rail transit medium voltage 35kV high flame retardant B1 grade cable as claimed in claim 3, characterized in that: The insulating semi-conductive shielding layer adopts 35kV cross-linked strippable semi-conductive shielding material.

Images