Novel high-current-carrying-capacity halogen-free low-smoke flame-retardant waterproof high-voltage cable

Abstract

The utility model provides a novel high-current-carrying-capacity halogen-free low-smoke flame-retardant waterproof high-voltage cable, which comprises a conductor, an insulating layer, a buffer layer, a metal shielding layer, a waterproof layer and a cooling layer, and is characterized in that the surface of the conductor is tightly coated with the insulating layer to form an insulating integrated structure; the buffer layer surrounds the insulating layer and is arranged between the insulating layer and the metal shielding layer; the waterproof layer wraps the surface of the shielding layer and is arranged between the shielding layer and the cooling layer; according to the utility model, the halogen-free low-smoke flame-retardant polyolefin material is utilized, so that the cable has excellent chemical corrosion resistance and halogen-free low-smoke flame-retardant performance, the environmental protection property and the safety are improved, and the water-blocking layer and the cooling layer are arranged, so that the cable is moistureproof, and meanwhile, the cable can be used as a power cable. The cable operation temperature is effectively reduced, the current-carrying capacity is greatly improved, the cost is reduced, the danger caused by overhigh temperature when the cable is short-circuited is reduced, and the cable is simple in production process, easy to store for a long time, environment-friendly, pollution-free and convenient to produce, transport and construct.

Description

Technical Field

[0001] The utility model relates to the technical field of cables, in particular to a novel high-current-carrying halogen-free, low-smoke, flame-retardant and waterproof high-voltage cable. Background Art

[0002] At present, most companies produce high-voltage cables with aluminum sheath + conventional plastic outer sheath structure to achieve flame retardant and waterproof functions. The structure process is relatively simple, mainly composed of conductor, insulation, buffer layer, metal aluminum sheath, and outer sheath. However, during the use of cables, the heat causes a significant reduction in current carrying capacity, which leads to the need to increase the conductor cross-section, resulting in increased costs and low conductor utilization efficiency.

[0003] At present, domestic high-voltage cables only have flame retardant performance requirements, and do not involve halogen-free and low-smoke flame retardant performance. Ordinary flame retardant high-voltage cables will release a lot of smoke when burning, which seriously endangers personal safety. Therefore, it is very important for 64 / 110kV high-voltage cables to use high-current carrying halogen-free and low-smoke flame retardant structures. Utility Model Content

[0004] The purpose of the utility model is to propose a cable structure with excellent flame retardant performance, high safety and simple process. To achieve the above purpose, the utility model proposes a new type of high current carrying capacity halogen-free low smoke flame retardant waterproof high voltage cable, including a conductor, an insulating layer, a buffer layer, a shielding layer, a water blocking layer and a cooling layer:

[0005] The insulating layer is tightly coated on the surface of the conductor to form an insulating integrated structure;

[0006] The buffer layer surrounds the insulating layer and is disposed between the insulating layer and the shielding layer;

[0007] The water blocking layer is coated on the surface of the shielding layer and is arranged between the shielding layer and the cooling layer;

[0008] A jacket is installed outside the cooling layer.

[0009] Furthermore, the conductor is a round, compacted, water-blocking conductor structure made of oxygen-free copper rods, wherein each layer of monofilaments in the conductor structure is longitudinally wrapped with a first water-blocking tape, and water-blocking yarn is plugged in the gap; a second water-blocking tape is wrapped around the conductor, and the second water-blocking tape is a semiconductor water-blocking binding tape. The conductor structure shown effectively ensures that the conductor surface is smooth, free of oil stains, and free of burrs and sharp edges that damage the insulation.

[0010] Furthermore, an inner shield and an outer shield are respectively provided on the inner and outer sides of the insulating layer. The insulating layer adopts a cross-linked polyethylene extrusion coating structure, which has the characteristics of high temperature resistance, strong insulation performance, non-melting, chemical corrosion resistance, high mechanical strength, and environmental protection. The cross-linked polyethylene together with the inner and outer shields are extruded at high pressure at the same time and tightly coated on the surface of the conductor to form an integrated insulating structure.

[0011] Furthermore, the average coating thickness of the insulating layer is not less than the nominal value, the thickness at the thinnest point is not less than 90% of the nominal thickness, the eccentricity is not greater than 10%, and the extruded surface is smooth without sharp corners, particles, burns, abrasions, etc.

[0012] Furthermore, the buffer layer adopts a semi-conductive buffer water-blocking tape wrapping structure to ensure that the insulating layer and the shielding layer maintain good electrical contact; the buffer layer wraps the third buffer water-blocking tape evenly around the surface of the insulating layer; the third buffer water-blocking tape is a semi-conductive buffer water-blocking tape; when wrapping, moisture should be avoided on the surface, the wrapping direction is right, and the overlap is 45-50%, so as to ensure the tightness of the wrapping tape and the stability of the structure.

[0013] Furthermore, the shielding layer is a metal shielding layer with a sparsely wound copper wire structure, which is convenient for grounding the short-circuit current when a cable fails; the copper wire is evenly wound on the surface of the buffer layer in a sparsely wound manner, and the sparse winding pitch is 9 to 12 times to ensure uniform spacing and structural stability of the copper wires; copper tape is used to reverse the surface of the sparsely wound copper wire, and a fourth buffer water-blocking tape is wrapped around the outer surface of the metal shielding layer, and the fourth buffer water-blocking tape is a semi-conductive buffer water-blocking tape.

[0014] Furthermore, the water-blocking layer adopts an aluminum-plastic composite tape longitudinally wrapped structure, and the aluminum-plastic composite tape is evenly wrapped on the surface of the shielding layer in a longitudinally wrapped manner to ensure that external water vapor and moisture will not enter the cable to cause copper wire oxidation and affect electrical performance. When wrapping, ensure that the longitudinal wrapping joints are firmly bonded and have good water-blocking performance.

[0015] Furthermore, the cooling layer is a circulating water cooling layer, and the cooling thin hoses are evenly arranged and evenly coated on the surface of the water blocking layer. When using thin hoses for coating, it is necessary to ensure that the thin hoses are evenly arranged and each thin hose is not damaged. During use, cooling circulating water is passed into the thin hoses in the cooling layer, thereby reducing the operating temperature of the cable, increasing the current carrying capacity, and effectively achieving cooling when the cable is short-circuited. At the same time, the cross-section of the copper wire in the shielding layer can also be greatly reduced.

[0016] Furthermore, the diameter of the thin hose is 4 mm.

[0017] Furthermore, the sheath adopts an extruded tube covering structure, and the sheath structure formed by extruding and stretching a halogen-free, low-smoke, flame-retardant polyolefin material is shrink-wrapped on the surface of the cooling layer, so that it has the advantages of chemical corrosion resistance, halogen-free, low-smoke, flame-retardant properties, prevention of fire spreading over a long distance when a fire occurs, and no smoke or less smoke generated during combustion.

[0018] Furthermore, the average coating thickness of the sheath is not less than the nominal value, the thickness at the thinnest point is not less than 90% of the nominal thickness, and the extruded surface is smooth without sharp corners, particles, burns, scratches and the like.

[0019] Furthermore, the outer surface of the sheath is coated with graphite to form a graphite conductive layer.

[0020] The specific steps of the production process of the utility model high-voltage cable are as follows:

[0021] Step 1: Prepare the conductor - use copper rods to draw and twist the conductor. In the conductor structure, each layer of monofilament is longitudinally wrapped with a first water-blocking tape and plugged with water-blocking yarn, and the conductor is wrapped with a second water-blocking tape.

[0022] Step 2: Prepare the insulation layer - extrude the cross-linked polyethylene together with the inner shield and the outer shield at high pressure at the same time, and tightly coat the conductor surface to form an insulation layer, wherein the average coating thickness is not less than the nominal value, the thinnest point thickness is not less than 90% of the nominal thickness, and the eccentricity is not more than 10%. The extruded surface should be smooth, without sharp corners, particles, burns, scratches, etc.

[0023] Step 3: Prepare the buffer layer - Wrap the third buffer water-blocking tape evenly on the surface of the insulation layer to form a buffer layer. When wrapping, avoid moisture on the surface. The wrapping direction is right, with an overlap of 45-50%, to ensure that the tape is tight and the structure is stable.

[0024] Step 4: Prepare a metal shielding layer - evenly wind the copper wire on the surface of the buffer layer in a sparse winding manner to form a metal shielding layer, wherein the sparse winding direction is left, and the sparse winding pitch is 9 to 12 times to ensure that the spacing of the copper wires is uniform and the structure is stable. In addition to the sparse winding of the copper wire, copper tape is used to reversely tie it, and a layer of fourth buffer water-blocking tape is wrapped around the outside of the metal shielding layer 7.

[0025] Step 5: Prepare the water-blocking layer - evenly wrap the aluminum-plastic composite tape on the surface of the metal shielding layer in a longitudinal manner to form a water-blocking layer. During the preparation process, ensure that the longitudinal seams are firmly bonded and have good water-blocking properties.

[0026] Step 6: Prepare a circulating water cooling layer - evenly arrange 4mm cooling thin hoses and cover the surface of the water blocking layer to form a circulating water cooling layer; during the arrangement process, ensure that the arrangement is uniform and that each thin hose is not damaged.

[0027] Step 7: Prepare the sheath - extrude and stretch the halogen-free, low-smoke, flame-retardant polyolefin material to form a sheath structure, and shrink-wrap it on the surface of the circulating water cooling layer to form a sheath; during the coating process, the average thickness of the extruded package shall not be less than the nominal value, and the thickness at the thinnest point shall not be less than 90% of the nominal thickness. The extruded surface shall be smooth without sharp corners, particles, burns, abrasions, etc.

[0028] Step 8: Graphite Coating - Graphite is coated on the outer surface of the sheath as a conductive layer.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] 1. The utility model adds a water-blocking layer and a cooling layer to the existing cable structure, and introduces cooling circulating water during operation, which not only ensures that external water vapor and moisture will not enter the cable, avoiding copper wire oxidation and affecting electrical performance, but also effectively reduces the cable operating temperature, greatly increases the current carrying capacity, reduces costs, and reduces the danger caused by excessive temperature when the cable is short-circuited.

[0031] 2. The utility model uses halogen-free, low-smoke, flame-retardant polyolefin material to form a sheath structure, which makes it have excellent chemical corrosion resistance and halogen-free, low-smoke, flame-retardant properties. When burning, it can effectively avoid the generation of excessive smoke; in the event of a fire, it can also effectively prevent the fire from spreading over a long distance, greatly improving environmental protection and safety.

[0032] 3. The production process of the utility model is simple and easy to operate, easy to store for a long time, non-toxic, odorless, pollution-free, and does not require the use of a large amount of expensive professional equipment. While reducing the weight of the equipment, it reduces the production cost and is also convenient for production, transportation and construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the overall planar structure of a new type of high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to an embodiment of the utility model. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be further described below.

[0035] This embodiment provides a novel high current carrying capacity halogen-free low smoke flame retardant waterproof high voltage cable, including a conductor 1, an insulating layer 5, a buffer layer 7, a metal shielding layer 8, a water blocking layer 10 and a cooling layer 11. Figure 1As shown, the insulating layer 5 is tightly coated on the surface of the conductor 1 to form an insulating integrated structure; the buffer layer 7 surrounds the insulating layer 5 and is arranged between the insulating layer 5 and the metal shielding layer 8; the water-blocking layer 10 is coated on the surface of the metal shielding layer 8 and is arranged between the metal shielding layer 8 and the cooling layer 11; a sheath 12 is also installed outside the cooling layer 11, and the outer surface of the sheath 11 is coated with graphite 13 as a conductive layer.

[0036] Among them, the water-blocking conductor 1 adopts a circular compressed water-blocking conductor structure, which is made of oxygen-free copper rods drawn and twisted. Its surface is smooth, free of oil stains, burrs and sharp edges that damage the insulation. Each layer of monofilament in the conductor structure is longitudinally wrapped with a first water-blocking tape, and a second water-blocking tape 2 is wrapped around the conductor 1. The second water-blocking tape 2 is a semiconductor water-blocking binding tape. Water-blocking yarn 3 is also plugged in the gap of the conductor 1. The insulating layer 5 tightly wrapped on the surface of the water-blocking conductor 1 adopts a cross-linked polyethylene material extrusion coating structure, which has the characteristics of high temperature resistance, strong insulation performance, non-melting, chemical corrosion resistance, high mechanical strength, and environmental protection; Figure 1 As shown, the inner and outer sides of the insulating layer 5 are respectively provided with an inner shield 4 and an outer shield 6. The cross-linked polyethylene material together with the inner shield 4 and the outer shield 6 are extruded at high pressure at the same time and tightly coated on the surface of the water-blocking conductor 1 to form an insulating integrated structure. During this coating process, the average coating thickness is not less than the nominal value, the thickness at the thinnest point is not less than 90% of the nominal thickness, the eccentricity is not greater than 10%, and the extruded surface is smooth without sharp corners, particles, burns, scratches, etc.

[0037] In this embodiment, the buffer layer 7 adopts a semi-conductive buffer water-blocking tape wrapping structure, and the third buffer water-blocking tape is evenly wrapped on the surface of the insulating layer 5 in a wrapping manner to ensure that the insulating layer 5 maintains good electrical contact with the metal shielding layer 8; the third buffer water-blocking tape is a semi-conductive buffer water-blocking tape, and when wrapping, it is necessary to avoid moisture on its surface, and the wrapping direction is right-handed, with an overlap of 45-50%, so as to ensure the tightness of the wrapping tape and the stability of the structure. The above-mentioned metal shielding layer 7 is composed of sparsely wound copper wires, which is convenient for short-circuit current grounding when the cable fails. In this embodiment, the copper wire is evenly wound on the surface of the buffer layer 7 in a sparsely wound manner, the sparsely wound direction is left-handed, and the sparsely wound pitch is 9-12 times, which is used to ensure the uniform spacing and structural stability of the copper wires. In addition, the copper wire is used to reversely tie the surface of the sparsely wound copper wire, and the outer surface of the metal shielding layer 7 is wrapped with a fourth buffer water-blocking tape 9, which is also a semi-conductive buffer water-blocking tape.

[0038] In this embodiment, Figure 1 As shown, the water-blocking layer 10 uses an aluminum-plastic composite tape to evenly wrap the surface of the metal shielding layer 8 in a longitudinal manner, mainly to prevent external water vapor and moisture from entering the cable, causing copper wire oxidation or affecting electrical performance.

[0039] In this embodiment, the circulating water cooling layer 11 realizes the cooling function by evenly covering the surface of the water blocking layer 9 with 4 mm thin hoses in a uniform arrangement. During operation, cooling circulating water is passed into the 4 mm thin hoses in the circulating water cooling layer 11, and the operating temperature of the cable is reduced by the temperature transfer of the cooling circulating water, thereby increasing the current carrying capacity. When the cable is short-circuited, the temperature can also be effectively reduced, and at the same time, the cross-section of the copper wire in the metal shielding layer 7 can also be greatly reduced.

[0040] In this embodiment, the sheath 12 adopts an extruded tube coating structure. The halogen-free low-smoke flame-retardant polyolefin material is extruded and stretched to form a sheath structure, and then shrink-coated on the surface of the cooling layer 11. The average coating thickness is not less than the nominal value, and the thickness at the thinnest point is not less than 90% of the nominal thickness. The extruded surface must be smooth without sharp corners, particles, burns, scratches, etc. Figure 1 As shown, the outer surface of the sheath 12 is coated with graphite 13 to form a graphite conductive layer.

[0041] The preparation process of the novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable in this embodiment is simple and easy to operate, and the specific steps are as follows:

[0042] Step 1: Prepare conductor 1 - use copper rods to draw and twist conductor 1, in the structure of conductor 1, each layer of monofilament is longitudinally wrapped with a first water-blocking tape, and the conductor is wrapped with a second water-blocking tape 2, i.e., a semi-conductive water-blocking binding tape, and the gap of conductor 1 is plugged with water-blocking yarn 3;

[0043] Step 2: Prepare the insulating layer 5 - extrude the cross-linked polyethylene together with the inner shield 4 and the outer shield 6 at high pressure at the same time, and tightly coat the surface of the conductor 1 to form the insulating layer 5, wherein the average coating thickness is not less than the nominal value, the thinnest point thickness is not less than 90% of the nominal thickness, and the eccentricity is not greater than 10%. The extruded surface should be smooth, without sharp corners, particles, burns, scratches, etc.;

[0044] Step 3: Prepare the buffer layer 7 - evenly wrap the third buffer water-blocking tape on the surface of the insulating layer 5 in a wrapping manner to form a buffer layer 7. When wrapping, avoid moisture on the surface. The wrapping direction is right, with an overlap of 45-50%, to ensure that the wrapping tape is tight and the structure is stable;

[0045] Step 4: Prepare the metal shielding layer 8 - The copper wire is evenly wound on the surface of the buffer layer 7 in a sparse winding manner to form the metal shielding layer 8, wherein the sparse winding direction is left-handed, and the sparse winding pitch is 9 to 12 times to ensure that the spacing of the copper wires is uniform and the structure is stable. In addition to the sparse winding of the copper wire, a copper tape is used to reversely tie it, and a fourth buffer water-blocking tape 9 is wrapped around the outside of the metal shielding layer 8;

[0046] Step 5: Prepare the water-blocking layer 10 - The aluminum-plastic composite tape is evenly coated on the surface of the metal shielding layer 8 in a longitudinal manner to form the water-blocking layer 10. During the preparation process, it is ensured that the longitudinal seams are firmly bonded and have good water-blocking properties.

[0047] Step 6: Prepare the circulating water cooling layer 11 - arrange 4 mm cooling thin hoses evenly and cover the surface of the water blocking layer 10 to form a circulating water cooling layer; during the arrangement process, ensure that the arrangement is uniform and the thin hoses are not damaged.

[0048] Step 7: Prepare the sheath 12 - extrude and stretch the halogen-free, low-smoke, flame-retardant polyolefin material to form a sheath structure, and shrink-wrap it on the surface of the circulating water cooling layer 11 to form the sheath 12; during the coating process, the average thickness of the extruded package shall not be less than the nominal value, the thickness at the thinnest point shall not be less than 90% of the nominal thickness, and the extruded package surface shall be smooth without sharp corners, particles, burns, abrasions, etc.

[0049] Step 8: Coating with graphite 13 - Graphite 13 is coated on the outer surface of the sheath 12 as a conductive layer.

[0050] The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable of this embodiment has the characteristics of good flexibility, being non-toxic, odorless, pollution-free, less smoke when burning, being environmentally friendly, safe, and water-resistant, etc. The process is simple and the construction is convenient, and it can be stored for more than 35 years under natural indoor conditions, and can pass the Class C flame retardant standard specified in GB12666.5.

[0051] The above are only preferred embodiments of the present invention and do not limit the present invention in any way. Any technician in the relevant technical field, without departing from the scope of the technical solution of the present invention, may make any equivalent replacement or modification to the technical solution and technical content disclosed in the present invention, which shall be deemed as the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A new type of high current carrying capacity halogen-free low smoke flame retardant waterproof high voltage cable, characterized in that: Including conductor, insulation layer, buffer layer, shielding layer, water blocking layer and cooling layer: The insulating layer is tightly coated on the surface of the conductor to form an insulating integrated structure; The buffer layer surrounds the insulating layer and is disposed between the insulating layer and the shielding layer; The water blocking layer is coated on the surface of the shielding layer and is arranged between the shielding layer and the cooling layer; A jacket is installed outside the cooling layer.

2. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The conductor is a round compressed water-blocking conductor structure formed by drawing and twisting oxygen-free copper rods, wherein each layer of monofilament in the conductor structure is longitudinally wrapped with a first water-blocking tape; the gaps of the conductor structure are filled with water-blocking yarn, and the conductor is wrapped with a second water-blocking tape.

3. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The inner and outer sides of the insulating layer are respectively provided with an inner shield and an outer shield. The insulating layer adopts a cross-linked polyethylene extrusion coating structure. The cross-linked polyethylene together with the inner and outer shields are extruded at high pressure at the same time and tightly coated on the surface of the conductor to form an insulating integrated structure.

4. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 3 is characterized in that: The average coating thickness of the insulating layer is not less than the nominal value, the thickness at the thinnest point is not less than 90% of the nominal thickness, and the eccentricity is not greater than 10%.

5. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The buffer layer adopts a semi-conductive buffer water-blocking tape wrapping structure, and the third buffer water-blocking tape is evenly wound on the surface of the insulating layer in a wrapping manner.

6. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The shielding layer is a metal shielding layer with a sparsely wound copper wire structure. The copper wire is evenly wound on the surface of the buffer layer in a sparsely wound manner, and the sparse winding pitch is 9 to 12 times; the outside of the sparsely wound copper wire surface is reversely tied with a copper tape, and the outer surface of the metal shielding layer is wrapped with a fourth buffer water-blocking tape.

7. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The water-blocking layer adopts an aluminum-plastic composite tape longitudinally wrapped structure, and the aluminum-plastic composite tape is evenly wrapped on the surface of the shielding layer in a longitudinally wrapped manner.

8. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The cooling layer is a circulating water cooling layer, and the cooling thin hoses are evenly arranged and evenly covered on the surface of the water blocking layer.

9. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 1 is characterized in that: The sheath adopts an extruded tube covering structure, and the sheath structure is formed by extruding and stretching a halogen-free low-smoke flame-retardant polyolefin material, and is shrink-coated on the surface of the cooling layer.

10. The novel high current carrying capacity halogen-free, low smoke, flame retardant and waterproof high voltage cable according to claim 9, characterized in that: The outer surface of the sheath is coated with graphite to form a graphite conductive layer.

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