CN219497395U - 27.5kV single-phase alternating-current flame-retardant waterproof environment-friendly electrified railway power cable - Google Patents

Abstract

The utility model discloses a 27.5kV single-phase alternating-current flame-retardant waterproof environment-friendly electrified railway power cable, which comprises an insulating wire core, a comprehensive metal shielding layer, a comprehensive waterproof layer, a comprehensive flame-retardant layer and an outer coating layer from inside to outside; the insulated wire core sequentially comprises a conductor, a conductor shielding layer, a plastic insulating layer and an insulating shielding layer from inside to outside, and the insulated wire core has the advantages of better flame retardance, waterproofness, animal biting prevention, environmental protection performance and safety and reliability.

Description

27.5kV single-phase alternating-current flame-retardant waterproof environment-friendly electrified railway power cable

Technical Field

The utility model relates to a power cable, in particular to a 27.5kV single-phase alternating-current flame-retardant waterproof environment-friendly electrified railway power cable.

Background

With the rapid development of large-scale passenger special line construction in China, the 27.5kV special cable for the electrified railway is more and more commonly used due to the influence of topography and environmental factors, the technical standard of the 27.5kV special cable for the electrified railway is GB/T28427-2012 < 27.5kV single-phase alternating-current crosslinked polyethylene insulated cable and accessories >, the standard flame-retardant characteristic requirement is only of flame-retardant C type, the requirements of an artificial weather aging test, the requirements of an animal biting test, the low-temperature performance are only conventional-15 ℃, the longitudinal water blocking requirements, the non-metallic material corrosiveness requirements and the like, various environmental conditions on the electrified railway site are hardly met, and the threat is generated to the safe and reliable operation of a cable line.

The metal shielding layer of the cable definitely adopts a combination form of sparse winding copper wire shielding and counter-binding copper wire or copper strip, and when the cable is electrified and heated, the shielding copper wire of the cable has a function on the insulation outer shielding due to the effect of the self weight of the cable, so that the insulation outer shielding is locally thinned and deformed, the service life of the cable is influenced, and the main method for reducing the problem generally comprises the following steps: 1) The thickness of the insulating outer screen is thickened in production. 2) And overlapping and wrapping the semiconductive tape in the shielding copper wire for buffering.

Disclosure of Invention

Aiming at the problems of flame retardance and water resistance of the existing 27.5kV single-phase alternating-current electrified railway power cable, the utility model aims to provide the 27.5kV single-phase alternating-current flame retardance and water resistance environment-friendly electrified railway power cable which has good flame retardance, waterproofness, animal biting prevention, environment-friendly performance and safety reliability, and can effectively overcome the problems existing in the prior art.

In order to achieve the purpose, the 27.5kV single-phase alternating-current flame-retardant waterproof environment-friendly electrified railway power cable comprises an insulating wire core, a comprehensive metal shielding layer, a comprehensive waterproof layer, a comprehensive flame-retardant layer and an outer coating layer from inside to outside; the insulated wire core sequentially comprises a conductor, a conductor shielding layer, a plastic insulating layer and an insulating shielding layer from inside to outside.

In a preferred embodiment of the present utility model, the conductor is a layered compacted and stranded type 2 single wire stranded round compacted conductor, and the material of the conductor can be copper, aluminum alloy or the like.

In a preferred embodiment of the present utility model, the plastic insulating layer is extruded from a plastic insulating material, which may be crosslinked polyethylene or polypropylene.

In a preferred embodiment of the utility model, the comprehensive metal shielding layer comprises an aluminum foil layer, a shielding copper wire layer and an anti-bundling copper tape layer from inside to outside.

In a preferred embodiment of the utility model, the comprehensive waterproof layer comprises a waterproof layer and a radial waterproof layer from inside to outside, the waterproof layer is formed by overlapping and wrapping a semiconductive waterproof tape on the comprehensive shielding layer, and the radial waterproof layer is formed by tightly wrapping and extruding a polyethylene sheath material on the waterproof layer.

In a preferred embodiment of the utility model, the comprehensive flame retardant layer comprises a flame retardant oxygen isolation layer, an inner heat insulation protective layer, a nonmagnetic wire armor layer and an outer heat insulation protective layer from inside to outside.

In a preferred embodiment of the utility model, the flame-retardant oxygen-insulating layer is formed by extruding fireproof mud on a radial waterproof layer. The inner heat-insulating protective layer and the outer heat-insulating protective layer are formed by overlapping and wrapping heat-insulating protective belts.

In a preferred embodiment of the utility model, the outer coating is extruded from a halogen-free low smoke flame retardant sheath material.

The beneficial effects of the utility model are as follows:

the 27.5kV single-phase alternating-current electrified railway power cable provided by the utility model has better flame retardance, waterproof property, animal biting prevention, environmental protection performance and safety reliability, and can effectively overcome the problems existing in the prior art.

Drawings

The utility model is further described below with reference to the drawings and the detailed description.

Fig. 1 is a cross-sectional illustration of a 27.5kV single-phase ac electrified railway power cable in an example of the utility model.

Description of the embodiments

The utility model is further described with reference to the following detailed drawings in order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the implementation of the utility model easy to understand.

Referring to the drawings, an example of the 27.5kV single-phase alternating-current electrified railway power cable structure provided by the utility model is shown.

As can be seen from the figure, the 27.5kV single-phase ac electrified railway power cable provided in this example is formed by matching an insulated wire core 100, an integrated metal shielding layer 200, an integrated waterproof layer 300, an integrated flame retardant layer 400, and an outer protective layer 500 from inside to outside.

In some embodiments of the present example, the insulated wire core 100 specifically includes a conductor 110, and a conductor shielding layer 120, a plastic insulating layer 130, and an insulating shielding layer 140 are sequentially coated on the periphery of the conductor 110 from inside to outside.

The conductor 110 is preferably a type 2 single wire stranded round compacted conductor.

Further, the material of the conductor 110 is copper or aluminum alloy.

Meanwhile, the conductor shielding layer 120, the plastic insulating layer 130 and the insulating shielding layer 140 are particularly preferably co-extruded on the conductor 110 through three layers, so that the insulating structure is stable, and the insulation of the conductor 110 can be ensured.

In some embodiments of the present example, the integrated metal shield 200 includes, from inside to outside, an aluminum foil layer 210, a shield copper wire layer 220, and a counter-tie copper strip layer 230.

Specifically, the aluminum foil layer 210 is formed by overlapping and wrapping aluminum foil on the insulated wire core 100, the shielding copper wire layer 220 is formed by sparse winding copper wires on the aluminum foil layer 210, the anti-bundling copper tape layer 230 is formed by wrapping soft copper tape gaps on the shielding copper wire layer 220, the aluminum foil layer 210 mainly reduces the action of the shielding copper wire layer 220 on the insulated shielding layer 140 when the cable is electrified and heated, and the aluminum foil layer 210 and the anti-bundling copper tape layer 230 are fully contacted and connected with the shielding copper wire layer 220 to jointly bear short-circuit current.

The integrated metal shielding layer 200 is adopted to cover the insulated wire core 100, is used for homogenizing an electric field and shielding external electromagnetic interference, and meets the functional requirement of bearing large short-circuit current by changing the number of copper wires and the diameter of a single wire of the shielding copper wire layer 220.

The comprehensive waterproof layer 300 comprises a waterproof layer 310 and a radial waterproof layer 320 from inside to outside, wherein the waterproof layer 310 is formed by overlapping and wrapping a semiconductive waterproof tape on the anti-binding copper tape layer 230, and the radial waterproof layer 320 is formed by tightly wrapping a polyethylene sheath material and extruding the polyethylene sheath material on the waterproof layer 310.

In some embodiments of the present example, the radial waterproof layer 320 is tightly extruded onto the composite metal shielding layer 200, in particular from polyethylene sheathing material, but does not adhere.

The semiconductive buffer water-blocking layer 210 and the water-blocking layer 310 expand rapidly when meeting water or moisture, fill up the gap between the insulating shielding layer 140 and the radial waterproof layer 320, have radial and longitudinal water-blocking effects, and can effectively prevent water or moisture outside the cable from entering the cable when the outer protective layer of the cable is damaged, so that the insulating performance of the cable is not reduced.

The radial waterproof layer 320 in this example is a compact plastic sleeve structure, and is substantially non-absorbent after encountering water, so that external moisture and humidity can be effectively prevented from radially entering the inside of the integrated metal shielding layer 200, corrosion of the flame-retardant oxygen-barrier layer 410 to the integrated metal shielding layer 200 can be prevented, and the radial waterproof performance is good.

As a further preferable scheme, the outer surface of the radial waterproof layer 320 is further provided with a plurality of uniformly distributed sawtooth protrusions, chamfering is needed at concave angles of the top convex corners and the bottom ends of the sawtooth, the radial waterproof layer 320 is convenient to extrude, the sawtooth height is about 80% of the effective thickness of the radial waterproof layer 320, the sawtooth width is equal to the groove width, and the width is 1.5-3 times of the sawtooth height. Therefore, the heat conduction performance of the radial waterproof layer 320 is good, heat can be absorbed and transferred to the comprehensive metal shielding layer 200 when the cable burns, the degree of insulation burning can be effectively reduced, the temperature of the external environment is reduced to rise too fast when the cable burns, and therefore the cable has good flame retardant performance.

In some embodiments of the present example, the composite flame retardant layer 400 includes, from inside to outside, a flame retardant oxygen barrier layer 410, an inner insulation shield layer 42, a non-magnetic wire armor layer, and an outer insulation shield layer 44.

In some embodiments of the present example, the flame retardant oxygen barrier layer 410 is formed by extrusion of fire clay over the radial waterproof layer 320.

The flame-retardant oxygen-insulating layer 410 and the radial waterproof layer 320 are crossed and matched, so that the flame-retardant oxygen-insulating layer 410 is stable in structure and uniform in thickness, and the thickness outside the sawtooth surface of the radial waterproof layer 320 is very thin, when the cable is bent, the cable is mainly stressed by the insulating core 100 and the radial waterproof layer 320 of the cable, and the flame-retardant oxygen-insulating layer 410 is smaller in stress, so that the whole cable is not hardened due to the structure of the flame-retardant oxygen-insulating layer 410, and the bending performance of the cable is not influenced.

As an example, the fireproof mud in this example is specifically formed by mixing liquid sodium silicate with inorganic mineral powder, wherein the inorganic mineral powder can be one or two of magnesium hydroxide or aluminum hydroxide, and the structure is harder and has a certain external force resistance effect; the flame-retardant oxygen-insulating layer 410 covers the whole outer surface of the radial waterproof layer 320, so that the radial waterproof layer 320 can be effectively protected from being damaged when the flame-retardant oxygen-insulating layer 410 is acted by external force, water can be separated out when the cable burns, and the flame-retardant oxygen-insulating layer has obvious effect on cooling the cable core; furthermore, as the main component of the structure is inorganic mineral substances, the structure becomes a hard shell after burning, has better effects of flame retardance, oxygen isolation, heat insulation and fire prevention, and can effectively slow down the burning degree of the insulated wire core 100.

In some embodiments of the present example, the inner heat-insulating protective layer 42 and the outer heat-insulating protective layer 44 are formed by overlapping wrapped heat-insulating protective strips, and the heat-insulating protective strips may be one or two of glass fiber strips or halogen-free low-smoke high-flame-retardant strips, so that the effect of the thermal expansion of the radial waterproof layer 320 on the flame-retardant oxygen-insulating layer 410 can be reduced, the flame-retardant oxygen-insulating layer 410 can be effectively protected from being damaged, and the formation of the honeycomb hard shell structure of the flame-retardant oxygen-insulating layer 41 during combustion can be better ensured and cannot be damaged; the heat insulation protective layer 42 can also block dust after combustible materials in the flame-retardant oxygen-insulating layer 41 are burnt out and cannot fall off, external heat transfer to the inside of the cable can be reduced, the inner heat insulation protective layer 42, the nonmagnetic wire armor layer 430 and the outer heat insulation protective layer 44 form a firewall of the cable, and the flame-retardant oxygen-insulating layer has better flame-retardant and mechanical protection effects, and the direction of the nonmagnetic wire armor is opposite to the wrapping direction of the heat insulation protective belt.

Further, the material of the nonmagnetic wire armor 430 is one of aluminum or aluminum alloy or stainless steel.

In some embodiments, the outer coating 5 in this example is formed by extruding a halogen-free low smoke flame retardant sheath material over the outer thermal insulation protective layer 4.

The coating 5 thus formed has a smaller heat release, better flame retardance and better mechanical and physical properties.

In some embodiments of the present example, the conductor shielding layer 120, the plastic insulating layer 130, the insulating shielding layer 140, the semiconductive buffer water-resistant layer 210, the water-resistant layer 310, the radial waterproof layer 320, the flame retardant oxygen-resistant layer 410, the inner heat insulation protection layer 420, the outer heat insulation protection layer 440, the outer coating layer 500, and the like are all halogen-free low smoke materials, so that the present application also has better environmental protection performance.

In addition, in the 27.5kV single-phase alternating current electrified railway power cable provided by the example, the flame-retardant oxygen-isolation layer 410, the inner heat-insulating protective layer 420, the nonmagnetic wire armor layer 430, the outer heat-insulating protective layer 440 and the outer coating layer 500 are all made of flame-retardant materials, so that the cable has better flame retardant performance.

The foregoing has shown and described the basic principles, principal features and advantages of the utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims. The scope of the utility model is defined by the appended claims and equivalents thereof.

Claims (5)

1. A27.5 kV single-phase alternating current flame-retardant waterproof environment-friendly electrified railway power cable is characterized in that: the power cable comprises an insulating wire core, a comprehensive metal shielding layer, a comprehensive waterproof layer, a comprehensive flame-retardant layer and an outer coating layer from inside to outside; the insulated wire core sequentially comprises a conductor, a conductor shielding layer, a plastic insulating layer and an insulating shielding layer from inside to outside; the comprehensive metal shielding layer comprises an aluminum foil layer, a shielding copper wire layer and an anti-binding copper tape layer from inside to outside, and the comprehensive flame-retardant layer comprises a flame-retardant oxygen-isolating layer, an inner heat-insulating protective layer, a nonmagnetic metal wire armor layer and an outer heat-insulating protective layer from inside to outside.

2. The 27.5kV single-phase ac flame-retardant waterproof environmentally friendly electrified railway power cable according to claim 1, wherein: the conductor is a layered compressed stranded type 2 single wire stranded round compressed conductor.

3. The 27.5kV single-phase ac flame-retardant waterproof environmentally friendly electrified railway power cable according to claim 1, wherein: the comprehensive waterproof layer comprises a waterproof layer and a radial waterproof layer from inside to outside, the waterproof layer is formed by overlapping and wrapping a semiconductive waterproof tape on the comprehensive shielding layer, and the radial waterproof layer is formed by tightly wrapping and extruding a polyethylene sheath material on the waterproof layer.

4. The 27.5kV single-phase ac flame-retardant waterproof environmentally friendly electrified railway power cable according to claim 1, wherein: the flame-retardant oxygen-insulating layer is formed by extruding fireproof mud on a radial waterproof layer, and the inner heat-insulating protective layer and the outer heat-insulating protective layer are formed by overlapping wrapped heat-insulating protective belts.

5. The 27.5kV single-phase ac flame-retardant waterproof environmentally friendly electrified railway power cable according to claim 1, wherein: the outer coating is formed by extruding and packing halogen-free low-smoke flame-retardant sheath materials.