WO2022036888A1 - B1-level 35kv looped network cable for urban rail transit traction power supply system - Google Patents

Abstract

A B1-level 35kV looped network cable for an urban rail transit traction power supply system, relating to the field of power supply circuits. The B1-level 35kV looped network cable for the urban rail transit traction power supply system comprises a cable core assembly (100), and a high-flame-retardant fireproof layer (210) and a copper-zinc alloy layer (220) that cover the cable core assembly (100). According to the B1-level 35kV looped network cable for the urban rail transit traction power supply system can solve the problem of heat release during cable combustion and improve the rat bite prevention capacity.

Description

A kind of urban rail transit traction power supply system B Class 1 35kV ring network cable

This application claims the priority of the patent application with the application number 202010834277.X filed with the State Intellectual Property Office of China on August 18, 2020.

technical field

The invention relates to the field of power supply cables, in particular to a B ₁ -level 35kV ring network cable for traction power supply systems of urban rail transit.

Background technique

The ring network cable used in the traction power supply system of rail transit mainly includes the outgoing cable from the main substation to the traction substation and the connecting cable between the traction substations.

In the related art, although the ring network cable has the characteristics of flame retardant, when the cable burns under fire conditions, it will still cause heat release hazards to the outside world, and the anti-rat bite performance of the cable is limited.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a B ₁ -level 35kV ring network cable for urban rail transit traction power supply system, which can improve the heat release problem when the ring network cable is burned, and can improve the ability to prevent rodent bites.

Embodiments of the present invention are implemented as follows:

In a first aspect, an embodiment of the present invention provides a B ₁ -level 35kV ring network cable for an urban rail transit traction power supply system, including a cable core assembly, a high flame-retardant fireproof layer and a copper-zinc alloy layer coated on the outside of the cable core assembly.

In an optional embodiment, a high flame retardant fireproof layer is sandwiched between the cable core assembly and the copper-zinc alloy layer.

In an alternative embodiment, the high flame retardant fire protection layer is made of a ceramified polyolefin material.

In an optional embodiment, the class B ₁ 35kV ring network cable for the urban rail transit traction power supply system further includes a polymer protective layer, and the polymer protective layer is the highest level of the B ₁ class 35kV ring network cable for the urban rail transit traction power supply system. outer layer.

In an alternative embodiment, the cable core assembly includes a conductor and a set of protective layers overlying the conductor.

In an optional embodiment, the protective layer group includes a conductor shielding layer, a cross-linked polyethylene insulating layer, and an insulating shielding layer that are sequentially coated on the outside of the conductor, and the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the insulating shielding layer. outside.

In an optional embodiment, the protective layer group further includes a semiconducting resistive water tape covered by the insulating shielding layer, and both the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the outer side of the semiconducting resistive water tape.

In an optional embodiment, the protective layer group further includes a copper wire shielding layer covered with a semiconducting resistance water tape, and both the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the outer side of the copper wire shielding layer.

In an optional embodiment, the protective layer group further includes a flame-retardant wrapping tape layer covered by the copper wire shielding layer, and the high flame-retardant fire-retardant layer and the copper-zinc alloy layer are both distributed on the outer side of the flame-retardant wrapping tape layer. .

In an optional embodiment, the protective layer group further includes a waterproof layer covered by a flame retardant wrapping tape layer, and both the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the outer side of the waterproof layer.

In an optional embodiment, in parts by weight, the raw materials for preparing the polymer protective layer include: 30-50 parts of ethylene-vinyl acetate copolymer resin, 40-70 parts of polyolefin elastomer, 5-15 parts of compatibilizer , 10-30 parts of composite reinforcing agent, 1-5 parts of composite lubricant, 10-20 parts of ceramic zinc borate, 40-80 parts of ultra-fine composite flame retardant, 1-5 parts of antioxidant, 1-3 parts of Dicumyl peroxide, 1-3 parts of triallyl isocyanurate, 0.5-2 parts of ultraviolet absorber, 1-5 parts of environmental protection termite agent, 1-5 parts of environmental protection rodent agent.

In an optional embodiment, the ultra-fine composite flame retardant includes magnesium hydroxide and aluminum hydroxide.

The beneficial effects of the B1 _- level 35kV ring network cable for the urban rail transit traction power supply system in the embodiment of the present invention include: the B1 _- level 35kV ring network cable for the urban rail transit traction power supply system provided by the embodiment of the present invention includes a cable core assembly and a package The high flame retardant fireproof layer and the copper-zinc alloy layer covering the outside of the cable core assembly; among them, the high flame retardant fireproof layer can absorb a lot of heat when it encounters flame burning, so as to avoid the burning of the ring network cable in the event of fire to the outside world. On the one hand, the copper-zinc alloy layer can help the high flame-retardant fire-retardant layer to play a role of flame retardant and fire prevention, thereby reducing the heat-releasing hazard, and can also use the smooth and hard nature of the copper-zinc alloy layer to prevent rat bite hazards.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation of the scope, and for those of ordinary skill in the art, other related drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic cross-sectional structure diagram of a B ₁ -level 35kV ring network cable used in an urban rail transit traction power supply system in an embodiment of the present invention;

FIG. 2 is a flow chart of the preparation process of the B ₁ -level 35kV ring network cable for the traction power supply system of the urban rail transit in the embodiment of the present invention.

Icon: 010-B1 class 35kV ring network cable for urban rail transit traction power supply system; 100-Cable core assembly; 210-High flame retardant fireproof layer; 220-Copper-zinc alloy layer; 230-Polymer protective layer; 110-Conductor; 120-protective layer group; 121-conductor shielding layer; 122-cross-linked polyethylene insulating layer; 123-insulating shielding layer; 124-semiconductor resistance water tape; 125-copper wire shielding layer; ; 127 - Waterproof layer.

detailed description

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "inside", "outside", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or is usually placed when the product of the invention is used. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "arrangement" and "connection" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, or It can be connected in one piece; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Example 1

Please refer to FIG. 1 , this embodiment provides a B ₁ -level 35kV ring network cable 010 for an urban rail transit traction power supply system, which can be used indoors, outdoors, underground, tunnels, cable trays or cable trenches that are often soaked in water, Substation cable interlayer and other places, especially for rail transit traction power supply system, such as: the outgoing cable from the main substation to the traction substation and the connection cable between the traction substations, etc.

_The grade B 35kV ring network cable 010 for urban rail transit traction power supply system includes a cable core assembly 100; further, the cable core assembly 100 includes a conductor 110 and a protective layer group 120 wrapped around the conductor 110, wherein the conductor 110 is used for Conductive, the protective layer group 120 has the functions of shielding and waterproofing.

It should be noted that the above-mentioned conductor 110 can be selected according to needs, for example, it can be a copper conductor; further, the second type of twisted and compressed copper conductor specified in the GB/T3956-2008 standard can be used, and the conductor 110 has a smooth surface and no damage to insulation. burrs, sharp edges, and raised or broken single lines are not specifically limited here.

The protective layer group 120 includes a conductor shielding layer 121 , a cross-linked polyethylene insulating layer 122 (XLPE insulating layer) and an insulating shielding layer 123 which are sequentially wrapped around the conductor 110 .

Optionally, the conductor shielding layer 121 can use a 35kV inner shielding material, and the performance should meet the requirements of the GB/T12706.3-2008 standard.

Optionally, the cross-linked polyethylene insulating layer 122 (XLPE insulating layer) can be made of 35kV chemically cross-linked insulating material, and the performance should meet the requirements of the GB/T12706.3-2008 standard.

Optionally, the insulating shielding layer 123 can use a 35kV non-peelable semi-conductive outer shielding material, and the performance should meet the requirements of the GB/T12706.3-2008 standard.

The protective layer group 120 further includes a semiconducting resistive water tape 124 covered by the insulating shielding layer 123 , and a copper wire shielding layer 125 covered by the semiconducting resistive water tape 124 .

It should be noted that the semiconducting resistance water tape 124 can be wrapped around the insulating shielding layer 123 as a buffer layer for copper wire shielding. It should be further noted that the semiconducting resistance water tape 124 wrapped around the insulating shielding layer 123 may be one layer, two layers, three layers, etc., which is not specifically limited here; that is, the insulating shielding layer 123 may be a single layer The wrapping semiconducting resistive water tape 124 may also be a multilayer wrapping semiconducting resistive water tape 124 .

Optionally, the copper wire shielding layer 125 may adopt a copper wire sparsely wound structure. It should be noted that the size of the copper wire shielding cross-sectional area can be determined according to the system fault short-circuit current.

The protective layer group 120 further includes a flame retardant wrapping tape layer 126 covered by the copper wire shielding layer 125 ; wrapping the flame retardant wrapping tape around the copper wire shielding layer 125 can protect the inner layer from being burned by flames.

It should be noted that the number of layers of flame retardant wrapping tapes wrapped around the copper wire shielding layer 125 may be one layer, two layers, three layers, etc., which is not specifically limited here; It can be a single-layer wrapping flame-retardant wrapping tape, or a multi-layer wrapping flame-retardant wrapping tape.

The protective layer group 120 further includes a waterproof layer 127 covered by the flame-retardant wrapping tape layer 126 . Specifically, the waterproof layer 127 may be an aluminum-plastic waterproof layer 127 .

Optionally, the aluminum-plastic waterproof layer 127 may adopt a longitudinally-wrapped aluminum-plastic composite tape structure.

_The B1 level 35kV ring network cable 010 for the urban rail transit traction power supply system in this embodiment further includes a high flame-retardant fireproof layer 210 and a copper-zinc alloy layer 220 that are coated on the outside of the cable core assembly 100 . Among them, the high flame-retardant fireproof layer 210 can absorb a large amount of heat when it encounters flame burning, so as to avoid the danger of heat release to the outside world caused by the burning of the B ₁ class 35kV ring network cable 010 for the traction power supply system of urban rail transit in the event of fire. On the one hand, the copper-zinc alloy layer 220 can assist the highly flame-retardant and fire-resistant layer 210 to play a flame-retardant and fire-resistant role, thereby reducing heat release hazards, and can also use the smooth and hard properties of the copper-zinc alloy layer 220 to prevent rat bite hazards.

Further, the high flame retardant fireproof layer 210 is sandwiched between the cable core assembly 100 and the copper-zinc alloy layer 220, so that the copper-zinc alloy layer 220 located outside the high flame-retardant fireproof layer 210 can be used to prevent the high flame-retardant fireproof layer 220. The layer 210 is directly burned by the flame, so as to ensure that the high flame-retardant fire _- proof layer 210 can fully exert its ability to absorb a large amount of fire in the event of an open flame such as a fire. The effect of heat can effectively improve the harm of heat release to the outside world when the B ₁ -level 35kV ring network cable 010 is burned for the traction power supply system of urban rail transit.

It should be noted that the high flame retardant fireproof layer 210 is sandwiched between the cable core assembly 100 and the copper-zinc alloy layer 220, and the high flame retardant fireproof layer 210 can also be located outside the aluminum-plastic waterproof layer 127, and the aluminum-plastic composite layer is longitudinally wrapped. The aluminum-plastic waterproof layer 127 with structure can be combined with the extruded high flame-retardant fireproof layer 210 to form the aluminum-plastic comprehensive waterproof layer 127 to realize the radial waterproof feature, so as to further ensure the B ₁ class 35kV ring network for the traction power supply system of urban rail transit. Water resistance of cable 010.

Optionally, the high flame retardant fireproof layer 210 can be made of ceramicized polyolefin (high thermal insulation ceramicized polyolefin) material, a large amount of ceramic powder is added to the material, the combustion calorific value is low, and the flame at about 550 ° C is made. The closed porous ceramic structure generated by porcelainization under ablation can have a good thermal insulation effect. At the same time, the low-temperature porcelain reaction process absorbs a large amount of heat, which effectively reduces the temperature of the insulating materials such as the insulating shielding layer 123 of the cable core assembly 100, and effectively reduces the B ₁ class 35kV ring network cable 010 used in the urban rail transit traction power supply system. Heat release rate and total heat release. That is to say, using the ceramicized polyolefin material can prevent the flame from burning through the high flame-retardant fireproof layer 210 on the one hand, and protect the cable core assembly 100; The leakage channel of the decomposed gas prevents the leakage of the internal gas from damaging the integrity of the outer sheath; when the outer sheath is burned by the flame, the propagation distance of the flame and the heat release of the outer sheath are controlled.

Optionally, the copper-zinc alloy layer 220 can be wrapped around the outside of the high flame-retardant fireproof layer 210 by using a copper-zinc alloy strip with a higher hardness. The hard alloy material prevents rats from chewing on the cable core.

It should be noted that the number of layers of the copper-zinc alloy layer 220 wrapped around the high flame retardant fireproof layer 210 may be one, two or three layers, etc., which is not specifically limited here; that is, the high flame retardant fireproof layer A single-layer copper-zinc alloy layer 220 can be wrapped outside the 210, or at least two copper-zinc alloy layers 220 can be overlapped and wrapped.

The B1 _- level 35kV ring network cable 010 for the urban rail transit traction power supply system in this embodiment further includes a polymer protective layer 230, and the polymer protection layer 230 is the most important part of the B1 _- level 35kV ring network cable 010 for the urban rail transit traction power supply system. Outer layer; further, the polymer protective layer 230 is coated on the outside of the copper-zinc alloy layer 220, which has the functions of anti-rat, anti-term and anti-ultraviolet. This setting makes the B ₁ -level 35kV ring network cable 010 for urban rail transit traction power supply system simultaneously waterproof, fireproof, rodent-proof, termite-proof and UV-proof to meet more diverse needs.

Optionally, the polymer protective layer 230 may be a low calorific value, halogen-free, low-smoke flame retardant polyolefin sheath material, and an efficient and environmentally friendly anti-mouse and termite agent is added to the polymer.

Further, in parts by weight, the raw materials for preparing the polymer protective layer 230 include:

Among them, the content of vinyl acetate (VA) in ethylene-vinyl acetate copolymer resin (EVA) is roughly 35-45%; EVA-g-MA is maleic anhydride modified EVA, and the purpose is to promote coupling agent and dispersion agent, so that the ultra-fine composite flame retardant is dispersed more uniformly in the resin.

The above-mentioned ultra-fine composite flame retardants are ultra-fine magnesium hydroxide and aluminum hydroxide, and the use of ultra-fine composite flame retardants can make the dispersion in the resin better and more uniform. The weight ratio of magnesium hydroxide to aluminum hydroxide may be 1:1-1.5.

It should be noted that ceramized zinc borate generates zinc oxide during the combustion process to promote the formation of char-forming agent, and in the flame retardant system of magnesium hydroxide and aluminum hydroxide, it can promote char-forming and form ceramization, that is, it can be dehydrated and carbonized to form a certain The thickness and strength of the carbon layer block combustion, effectively play the role of smoke suppression, flame retardant, and anti dripping. And the ceramicized zinc borate/aluminum hydroxide/magnesium hydroxide has a synergistic effect and has excellent flame retardant performance, so as to further improve the flame retardant performance of B ₁ class 35kV ring network cable 010 for urban rail transit traction power supply system.

The above-mentioned composite reinforcing agent includes at least one of carbon black, white carbon black, acetylene carbon black and diatomaceous earth, and further, the composite reinforcing agent includes carbon black, white carbon black, acetylene carbon black and diatomaceous earth. any two.

The above-mentioned composite lubricant can be selected from at least one of zinc stearate and hydroxy silicone oil; further, the composite lubricant can be selected from zinc stearate and hydroxy silicone oil, and the weight ratio of the two can be 1:0.5-1.5.

The above-mentioned antioxidants generally select hindered phenolic antioxidants, which can be any at least one such as antioxidant 1076, antioxidant 264 and antioxidant 1010, which are not specifically limited here; Stabilizer, can be any at least one such as 2-hydroxy-4-methoxy benzophenone and 2-hydroxy-4-n-octyloxy benzophenone, which is not specifically limited here; Select any at least one of capsaicin, capsaicin and trans-capsaicin, etc., which is not specifically limited here; the environmental protection termite agent generally selects any at least one such as chlorpyrifos and carbamate, which is not specifically limited here.

Optionally, the preparation method of the polymer protective layer 230 includes: weighing and mixing each raw material, transferring it to a twin-screw extruder for extrusion, the temperature is 120-180° C., the screw speed is 60-600 rpm, and then Pelletize at 120-140°C.

In this embodiment, the preparation method of the polymer protective layer 230 is as follows: 30 parts of ethylene-vinyl acetate copolymer resin, 40 parts of polyolefin elastomer, 5 parts of compatibilizer, 10 parts of composite reinforcing agent, 1 part of composite lubricant 10 parts of ceramic zinc borate, 40 parts of ultra-fine composite flame retardant, 1 part of antioxidant, 1 part of dicumyl peroxide, 1 part of triallyl isocyanurate, 0.5 part of ultraviolet absorber 1 part of environmental protection termite agent, 1 part of environmental protection rodent agent are mixed, transferred to a twin-screw extruder for extrusion, the temperature is 120 ° C, the screw speed is 60 rpm, and then pelletized at 120 ° C.

Referring to FIG. 2 , the preparation process of the B ₁ -level 35kV ring network cable 010 for the urban rail transit traction power supply system of the present embodiment includes: using a three-layer co-extrusion process to sequentially coat the conductor shielding layer 121 on the outside of the conductor 110, cross-linking The polyethylene insulating layer 122 and the insulating shielding layer 123; then the semiconducting resistance water tape 124 covered by the insulating shielding layer 123; then the copper wire shielding layer 125 covered by the semiconducting resistance water tape 124; then the copper wire The flame retardant wrapping tape layer 126 covered by the shielding layer 125; then the waterproof layer 127 and the high flame retardant fireproof layer 210 are sequentially wrapped outside the flame retardant wrapping tape layer 126; The copper-zinc alloy layer 220 is clad; finally, the copper-zinc alloy layer 220 is covered with a polymer protective layer 230; after that, the finished product inspection is performed.

The test results of the B ₁ -level 35kV ring network cable 010 used in the urban rail transit traction power supply system of this embodiment are as follows:

1. The DC resistance of conductor 110 of B ₁ 35kV ring network cable 010 for urban rail transit traction power supply system at 20°C meets the requirements of GB/T 3956-2008.

2. Flame retardant performance of B ₁ grade 35kV ring network cable 010 for urban rail transit traction power supply system: measured according to the test method specified in GB 31247-2014, and the measured results meet the B ₁ grade classification criterion; burning dripping objects / The particle level meets d ₀ level, that is, there is no burning droplets/particles within 1200s; the flue gas toxicity level meets t ₀ level, that is, ZA level ₂ ; the corrosiveness level meets a ₁ level, that is, the electrical conductivity ≤ 2.5μs/mm , PH≥4.3.

3. Radial water blocking performance of B ₁ class 35kV ring network cable 010 for urban rail transit traction power supply system: After soaking the B ₁ class 35kV ring network cable 010 sample in water for 72 hours, the insulation layer was removed After the outer composite layer, visually observe that the outer surface of the insulating layer is dry.

4. The anti-rat performance of B ₁ class 35kV ring network cable 010 for urban rail transit traction power supply system: according to the regulations of JB/T 10696.10-2011, the rat gnawing test is carried out, and the protection level reaches "significant", that is, the protection rate is ≥ 0.9 , no dents or light dents.

5. Anti-termite performance of class B ₁ 35kV ring network cable 010 for urban rail transit traction power supply system: Termite test was conducted in accordance with the provisions of JB/T 10696.9-2011 "Experimental Colony Method", and the decay level reached level 1, that is, no tooth marks. .

6. Anti-ultraviolet performance of class B ₁ 35kV ring network cable 010 for urban rail transit traction power supply system: perform artificial weather resistance aging test (xenon lamp method) in accordance with the provisions of GB/T 12527-2008, after 42 days of aging, protect the The rate of change in tensile strength and the rate of change in elongation at break conform to the standard.

Example 2

Example 2 is similar to Example 1, the difference lies in the specific preparation method of the polymer protective layer, the preparation method of the polymer protective layer 230 in Example 2 is: 50 parts of ethylene-vinyl acetate copolymer resin, 70 parts of poly Olefin elastomer, 15 parts of compatibilizer, 30 parts of composite reinforcing agent, 5 parts of composite lubricant, 20 parts of ceramic zinc borate, 80 parts of ultrafine composite flame retardant, 5 parts of antioxidant, 3 parts of peroxide Dicumylbenzene, 3 parts of triallyl isocyanurate, 2 parts of ultraviolet absorber, 5 parts of environmental protection termite repellant, 5 parts of environmental protection rodent repellant were mixed, transferred to a twin-screw extruder for extrusion, The temperature is 180°C, the screw speed is 600 rpm, and the pellets are formed at 140°C.

Among them, the ethylene-vinyl acetate copolymer resin contains 40% VA; the ultra-fine composite flame retardant includes aluminum hydroxide and magnesium hydroxide in a weight ratio of 1:1; the composite reinforcing agent includes a weight ratio of 1:1.5 carbon black and white carbon black; composite lubricants include zinc stearate, hydroxy silicone oil in a weight ratio of 1:1.5; antioxidants include antioxidant 1076; UV absorbers include 2-hydroxy-4-methoxydiol Benzophenone; environmentally friendly rodent repellents include capsaicin; environmentally friendly termite control agents include chlorpyrifos.

Example 3

Example 3 is similar to Example 1, the difference lies in the specific preparation method of the polymer protective layer. The preparation method of the polymer protective layer 230 in Example 3 is: 40 parts of ethylene-vinyl acetate copolymer resin, 50 parts of poly Olefin elastomer, 10 parts of compatibilizer, 20 parts of composite reinforcing agent, 3 parts of composite lubricant, 15 parts of ceramic zinc borate, 70 parts of ultrafine composite flame retardant, 3 parts of antioxidant, 2 parts of peroxide Dicumylbenzene, 2 parts of triallyl isocyanurate, 1 part of ultraviolet absorber, 3 parts of environmentally friendly termite repellant, and 3 parts of environmentally friendly rodent repellant were mixed and transferred to a twin-screw extruder for extrusion. The temperature is 150°C, the screw speed is 200 rpm, and the pellets are formed at 130°C.

Among them, the ethylene-vinyl acetate copolymer resin contains 35% VA; the ultrafine composite flame retardant includes aluminum hydroxide and magnesium hydroxide in a weight ratio of 1:1.5; the composite reinforcing agent includes a weight ratio of 1:1 acetylene carbon black or diatomaceous earth; the composite lubricant includes zinc stearate and hydroxy silicone oil in a weight ratio of 1:0.5; the antioxidant includes antioxidant 264; the ultraviolet absorber includes 2-hydroxy-4-n-octyloxy benzophenone; environmentally friendly rodent repellants include capsaicin and trans-capsaicin; environmentally friendly termite inhibitors include carbamates.

Example 4

Example 4 is similar to Example 1, the difference lies in the specific preparation method of the polymer protective layer. The preparation method of the polymer protective layer 230 in Example 4 is: 40 parts of ethylene-vinyl acetate copolymer resin, 50 parts of poly Olefin elastomer, 12 parts of compatibilizer, 16 parts of composite reinforcing agent, 4 parts of composite lubricant, 12 parts of ceramic zinc borate, 56 parts of ultrafine composite flame retardant, 2 parts of antioxidant, 3 parts of peroxide Dicumyl benzene, 1 part of triallyl isocyanurate, 0.8 part of ultraviolet absorber, 4 parts of environmental protection termite agent, and 3 parts of environmental protection rodent repellant were mixed and transferred to a twin-screw extruder for extrusion. The temperature is 170°C, the screw speed is 400 rpm, and the pellets are formed at 125°C.

Among them, the ethylene-vinyl acetate copolymer resin contains 45% VA; the ultra-fine composite flame retardant includes aluminum hydroxide and magnesium hydroxide in a weight ratio of 1:1.2; the composite reinforcing agent includes a weight ratio of 1:1.5 of carbon black and diatomaceous earth; the composite lubricant includes zinc stearate and hydroxy silicone oil in a weight ratio of 1:0.8; the antioxidant includes antioxidant 1010; the ultraviolet absorber includes 2-hydroxy-4-methoxydiol Benzophenone and 2-hydroxy-4-n-octyloxybenzophenone; environmental rodent repellents include trans-capsaicin; environmental termite repellents include chlorpyrifos and carbamates.

Example 5

Example 5 is similar to Example 1, the difference lies in the specific preparation method of the polymer protective layer, the preparation method of the polymer protective layer 230 in Example 5 is: 35 parts of ethylene-vinyl acetate copolymer resin, 55 parts of poly Olefin elastomer, 8 parts of compatibilizer, 22 parts of composite reinforcing agent, 3 parts of composite lubricant, 16 parts of ceramic zinc borate, 65 parts of ultrafine composite flame retardant, 2 parts of antioxidant, 1 part of peroxide Dicumylbenzene, 3 parts of triallyl isocyanurate, 1 part of ultraviolet absorber, 2 parts of environmental protection termite repellant, 5 parts of environmental protection rodent repellant were mixed, transferred to a twin-screw extruder for extrusion, The temperature is 140°C, the screw speed is 100 rpm, and then the pellets are formed at 135°C.

Among them, the ethylene-vinyl acetate copolymer resin contains 41% VA; the ultra-fine composite flame retardant includes aluminum hydroxide and magnesium hydroxide in a weight ratio of 1:1.1; the composite reinforcing agent includes a weight ratio of 1:1 : 1:1 carbon black, white carbon black, acetylene carbon black and diatomaceous earth; composite lubricants include hydroxy silicone oil; antioxidants include antioxidant 1076, antioxidant 264 and antioxidant 1010; UV absorbers include 2-Hydroxy-4-methoxybenzophenone; environment-friendly rodent repellents include capsaicin; environment-friendly termite repellents include chlorpyrifos.

To sum up, the class B ₁ 35kV ring network cable 010 for the urban rail transit traction power supply system provided by the present invention can utilize the high flame retardant fireproof layer 210 to absorb a large amount of heat when encountering flame burning, so as to avoid urban rail transit traction power supply. The system uses B ₁ class 35kV ring network cable 010 to burn in the event of fire, which will cause heat release to the outside world. On the one hand, the copper-zinc alloy layer 220 can assist the high flame-retardant fire-retardant layer 210 to play the role of flame-retardant and fire-proof, thereby reducing the risk of fire. The heat release hazard can also be prevented by the smooth and hard nature of the copper-zinc alloy layer 220 to prevent rat bite hazard.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A class B ₁ 35kV ring network cable for urban rail transit traction power supply system is characterized in that it includes a cable core assembly, a high flame retardant fireproof layer and a copper-zinc alloy layer coated on the outside of the cable core assembly.
2. The class B ₁ 35kV ring network cable for urban rail transit traction power supply system according to claim 1, wherein the high flame retardant fireproof layer is sandwiched between the cable core assembly and the copper-zinc alloy layer .
3. The B ₁ grade 35kV ring network cable for urban rail transit traction power supply system according to claim 1, characterized in that, the high flame retardant fireproof layer is made of ceramicized polyolefin material.
4. The B1-level 35kV ring network cable for urban rail transit traction power supply system according to claim ₁ , characterized in that, the B1 _- level 35kV ring network cable for urban rail transit traction power supply system further comprises a polymer protective layer, so the The polymer protective layer is the outermost layer of the B ₁ -level 35kV ring network cable used in the urban rail transit traction power supply system.
5. The B ₁ grade 35kV ring network cable for urban rail transit traction power supply system according to claim 4, characterized in that, in parts by weight, the preparation raw materials of the polymer protective layer include: 30-50 parts of ethylene-vinyl acetate Copolymer resin, 40-70 parts of polyolefin elastomer, 5-15 parts of compatibilizer, 10-30 parts of composite reinforcing agent, 1-5 parts of composite lubricant, 10-20 parts of ceramic zinc borate, 40-80 parts parts of ultra-fine composite flame retardant, 1-5 parts of antioxidant, 1-3 parts of dicumyl peroxide, 1-3 parts of triallyl isocyanurate, 0.5-2 parts of ultraviolet absorber, 1-5 parts of environmental protection termite agent, 1-5 parts of environmental protection rodent agent.
6. The B ₁ -level 35kV ring network cable for urban rail transit traction power supply system according to claim 5, wherein the ultra-fine composite flame retardant comprises magnesium hydroxide and aluminum hydroxide.
7. The B ₁ -level 35kV ring network cable for urban rail transit traction power supply system according to claim 1, characterized in that, the cable core assembly includes a conductor and a protective layer group wrapped around the conductor.
8. The B1 _- level 35kV ring network cable for urban rail transit traction power supply system according to claim 7, wherein the protective layer group comprises a conductor shielding layer and a cross-linked polyethylene insulating layer that are sequentially wrapped outside the conductor. and an insulating shielding layer, and both the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the outer side of the insulating shielding layer.
9. The B ₁ -level 35kV ring network cable for urban rail transit traction power supply system according to claim 8, characterized in that, the protective layer group further comprises semiconducting resistance water tape and copper wire which are sequentially wrapped outside the insulating shielding layer. A wire shielding layer, and the high flame retardant fireproof layer and the copper-zinc alloy layer are both distributed on the outer side of the copper wire shielding layer.
10. The B ₁ -level 35kV ring network cable for the traction power supply system of urban rail transit according to claim 9, wherein the protective layer group further comprises a flame retardant wrapping tape layer sequentially wrapped outside the copper wire shielding layer and a waterproof layer, and both the high flame retardant fireproof layer and the copper-zinc alloy layer are distributed on the outer side of the waterproof layer.

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