CN115762857A - Cable and preparation method thereof - Google Patents
Cable and preparation method thereof Download PDFInfo
- Publication number
- CN115762857A CN115762857A CN202211531343.1A CN202211531343A CN115762857A CN 115762857 A CN115762857 A CN 115762857A CN 202211531343 A CN202211531343 A CN 202211531343A CN 115762857 A CN115762857 A CN 115762857A
- Authority
- CN
- China
- Prior art keywords
- antioxidant
- cable
- layer
- parts
- insulating layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A30/00—Adapting or protecting infrastructure or their operation
- Y02A30/14—Extreme weather resilient electric power supply systems, e.g. strengthening power lines or underground power cables
Landscapes
- Insulated Conductors (AREA)
Abstract
The invention provides a cable and a preparation method thereof. The cable at least comprises a conductor, an inner shielding layer, an insulating layer and an outer shielding layer; the inner shielding layer is arranged outside the conductor in a covering mode, the insulating layer is arranged outside the inner shielding layer in a covering mode, and the outer shielding layer is arranged outside the insulating layer in a covering mode; wherein the insulating layer comprises the following components in parts by mass: 100 parts of polypropylene; 3-5 parts of a first antioxidant; the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant 330, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is (3-7): (1-3): (1-4). The cable has excellent electrical insulation performance (can be applied to the voltage class of 66kV and above) and mechanical performance.
Description
Technical Field
The invention relates to a cable and a preparation method thereof, and belongs to the technical field of materials and cables.
Background
At present, a cross-linked polyethylene material is often used as an insulating material for an insulated power cable, but the cross-linked polyethylene material is difficult to recycle and can only be incinerated or smashed for landfill, so that energy waste and environmental pollution are easily caused, more and more cable manufacturers aim at a polypropylene insulating material, but the existing polypropylene insulating material still cannot completely meet the use requirements of the power cable due to the defects of low use voltage, poor mechanical performance and the like.
Disclosure of Invention
The invention provides a cable which has excellent electrical insulation performance (can be applied to the voltage class of 66kV and above) and mechanical performance.
The invention provides a preparation method of a cable, which can be used for preparing the cable, has a simple preparation process, is convenient to operate and is suitable for wide popularization and application.
The invention provides a cable, which at least comprises a conductor, an inner shielding layer, an insulating layer and an outer shielding layer;
the inner shielding layer is arranged outside the conductor in a coated mode, the insulating layer is arranged outside the inner shielding layer in a coated mode, and the outer shielding layer is arranged outside the insulating layer in a coated mode;
wherein the insulating layer comprises the following components in parts by mass:
100 parts of polypropylene;
3-5 parts of a first antioxidant;
the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant 330, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is (3-7): (1-3): (1-4).
The cable as described above, wherein the insulating layer further comprises, in parts by mass: 2-5 parts of an elastomer;
the elastomer is selected from at least one of BR, SBR, EPR, EVA, EPMD, POE and SEBS.
The cable as described above, wherein the elastomer is selected from the group consisting of EPMD, EVA and SBR, and the mass part ratio of the EPMD, EVA and SBR is (3-6): (1-3): (1-4).
The cable as described above, wherein the inner shield layer and/or the outer shield layer include, in parts by mass:
100 parts of polypropylene;
2-5 parts of carbon black.
The cable as described above, wherein the inner shield layer and/or the outer shield layer further comprises, in parts by mass:
2-6 parts of a second antioxidant;
2-5 parts of a copper inhibitor.
The cable as described above, wherein the second antioxidant consists of antioxidant 1010 and antioxidant 330;
the copper resisting agent is a copper resisting agent 1024.
The cable as described above, wherein in the inner shield layer and/or the outer shield layer, the mass ratio of the antioxidant 1010, the antioxidant 330 and the copper inhibitor 1024 is (1-5): (1-5): (1-4).
The invention also provides a preparation method of the cable, which comprises the following steps:
and sequentially coating an inner shielding layer, an insulating layer and an outer shielding layer on the outer part of the conductor by using a three-layer co-extrusion machine head to obtain the cable.
The preparation method as described above, wherein the extrusion temperature of the insulating layer is 155-255 ℃; and/or the presence of a gas in the gas,
the extrusion temperature of the inner shielding layer and/or the outer shielding layer is 155-255 ℃; and/or the presence of a gas in the gas,
the ratio of the screw rotation speed to the linear speed of the extruder is 8-12.
The manufacturing method as described above, wherein the cable is sequentially subjected to air cooling treatment and water cooling treatment.
The cable has excellent electrical insulating performance (capable of being applied to voltage classes of 66kV and above) and mechanical performance because the insulating layer in the cable comprises the first antioxidant with specific content and specific composition.
The cable preparation method of the invention can prepare the cable with excellent electrical insulating property and mechanical property.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the related art, the drawings used in the description of the embodiments of the present invention or the related art are briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
Fig. 1 is a schematic cross-sectional view of a cable according to some embodiments of the present invention.
Description of reference numerals:
1: a conductor;
2: an inner shield layer;
3: an insulating layer;
4: an outer shield layer;
5: a buffer layer;
6, a metal sheath;
7: an outer sheath.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Fig. 1 is a schematic cross-sectional view of a cable according to some embodiments of the present invention. As shown in fig. 1, in some embodiments of the present invention, a cable includes at least a conductor 1, an inner shield layer 2, an insulation layer 3, and an outer shield layer 4;
the inner shielding layer 2 is arranged outside the conductor 1 in a coating mode, the insulating layer 3 is arranged outside the inner shielding layer 2 in a coating mode, and the outer shielding layer 4 is arranged outside the insulating layer 3 in a coating mode;
wherein, the insulating layer 3 comprises the following components in parts by mass:
100 parts of polypropylene;
3-5 parts of a first antioxidant;
the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant 330, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is (3-7): (1-3): (1-4).
In the present invention, the covering setting means that the covering material is completely covered on the axially extending outer part of the material to be covered, the inner shielding layer material is used as the covering material, the conductor 1 is used as the material to be covered, and the exemplary description is given by way of example, and the covering setting of the inner shielding layer 2 on the outer part of the conductor 1 means that the inner shielding layer material is completely covered on the axially extending outer part of the conductor 1, so that the inner shielding layer 2 is formed on the outer part of the conductor 1. The specific manner of the wrapping arrangement is not particularly limited, and in some reverse embodiments, the wrapping arrangement may be implemented in a wrapping manner, and in other embodiments, the wrapping arrangement may be implemented in a sleeving manner.
It can be understood that the cable of the present invention comprises a conductor 1, an inner shielding layer 2, an insulating layer 3 and an outer shielding layer 4 in sequence from the cable core to the outside. The conductor 1 is not particularly limited, and the material and the size of the conductor 1 can be determined according to actual requirements, for example, the conductor 1 can be copper or aluminum, and the outer diameter of the conductor 1 can be 18-74mm; the inner shielding layer 2 and the outer shielding layer 4 are used for realizing the electrostatic shielding effect, and in the invention, the thickness of the inner shielding layer 2 and/or the thickness of the outer shielding layer 4 can be selected according to actual needs, for example, the thickness of the inner shielding layer 2 can be 1.2-3mm, and the thickness of the outer shielding layer 4 can be 0.8-2.1mm; the insulating layer 3 functions as electrical insulation.
The insulating layer 3 comprises 100 parts by mass of polypropylene and 3-5 parts by mass of a first antioxidant, wherein the polypropylene is a base material of the insulating layer 3, and the first antioxidant is used for improving the thermal breakdown electrical strength, the light aging performance and the heat aging performance of the insulating layer 3.
Compared with the single antioxidant, the first antioxidant can greatly reduce the decomposition degree of a polypropylene (PP) molecular chain, improve the melting peak temperature of the PP molecular chain, and improve the thermal breakdown electric strength, the light aging resistance and the heat aging resistance of the insulating layer 3.
Illustratively, adding 1 part by mass of antioxidant 1010 to 100 parts by mass of polypropylene results in an insulation layer having an oxidation induction period of 30min, whereas adding 2 parts by mass or more of antioxidant 1010 to 100 parts by mass of polypropylene results in an insulation layer 3 having an oxidation induction period that is substantially constant, indicating that a single antioxidant has a limited improvement in the aging resistance of the insulation layer 3;
adding 1 part by mass of antioxidant 1010 and 1 part by mass of antioxidant 168 into 100 parts by mass of polypropylene to form an insulating layer 3 with an oxidation induction period of 36min, and adding 1 part by mass of antioxidant 1010 and 2 parts by mass or more antioxidant 168 into 100 parts by mass of polypropylene to form an insulating layer 3 with an oxidation induction period that is basically unchanged, which indicates that compared with a single antioxidant, the addition of two antioxidants can further alleviate the auto-oxidation degradation Process of Polypropylene (PP) molecular chains to a certain extent and improve the aging resistance of the insulating layer 3, but the improvement performance is still limited;
and 3-5 parts by mass of a first antioxidant is added into 100 parts by mass of polypropylene, the first antioxidant comprises 5 parts by mass of antioxidant 1010, 2 parts by mass of antioxidant 168 and 3 parts by mass of antioxidant 330, and the oxidation induction period of the formed insulating layer 3 is 90min, which shows that the first antioxidant with a specific composition can greatly improve the aging resistance of the insulating layer 3, and further can improve the mechanical properties of the insulating layer 3.
The first antioxidant of the invention can also improve the mechanical properties of the insulating layer 3, thereby improving the mechanical properties of the cable.
Illustratively, mechanical property tests were performed on cables made according to the invention before the aging resistance test, with PP insulation having an elongation at break of more than 800% and a tensile strength of more than 42.4N/mm 2 (ii) a The cable of the invention is put in an air box for aging testAfter the test (the temperature of an air box is 150 ℃, the time of an aging test is 240 hours), the breaking elongation of the cable is more than 780 percent, and the tensile strength is more than 40.4N/mm 2 It is demonstrated that the cable of the present invention has excellent mechanical properties.
The first antioxidant can also play a role in heterogeneous nucleation, increases the point number of crystal nuclei in a PP molecular chain, ensures that spherulites formed by PP are small and perfect, ensures that the distribution size of crystals is more uniform, and improves the electrical insulation performance of the insulating layer 3.
Illustratively, when the thickness of the insulating layer 3 is 0.2mm, the insulating layer 3 of the present invention may have an electrical insulation strength of 150kV/mm at 20 ℃ and an electrical insulation strength of 120kV/mm at 90 ℃ and an electrical insulation strength of 110kV/mm at 105 ℃; in the prior art, the electric insulation strength of a polyethylene insulation layer (XLPE) at 20 ℃ can reach 130kV/mm, the electric insulation strength at 90 ℃ can reach 70kV/mm, and the electric insulation strength at 105 ℃ can reach 20kV/mm, which shows that the insulation layer 3 with a specific composition has more excellent electric insulation performance.
In addition, taking the cable with the limited voltage of 500kV as an example, the cable system is formed by the 500kV cable, a through joint, an insulating joint, a full-sealing plugging dry GIS long terminal, a full-sealing plugging dry GIS short terminal, a composite sleeve type outdoor terminal and a porcelain sleeve type outdoor terminal, the temperature of a conductor is increased to 125 ℃ from 95 ℃ in a thermal cycle voltage test of a type test, the cable is subjected to 30 thermal cycles, and 725kV (2.5U) is applied to the cable 0 ) The insulation layer does not break down, indicating that the cable has excellent electrical insulation properties.
The method comprises the steps of carrying out gradual lightning impulse test on a 500kV cable, pressurizing from 1550kV, and pressurizing 150kV step by step each time until the voltage is 3050kV, wherein the voltage is positive and negative for 10 times, the insulation is not broken down, and then the voltage is 870kV (3U) 0 ) And 30min, insulation is not broken down.
The melting point of the insulating layer 3 of the invention is 160 ℃, the conductor temperature is 125 ℃ in a 500kV cable type test, and 30 thermal cycle voltage tests (2.5U) are completed 0 ) After the test, the lightning impacts are 1800kV, the times of each lightning impact are respectively 10, and the insulation is not broken down and the flashover is not causedThen withstand voltage of 3U 0 30min, the insulation did not break down, no discharge beyond the claimed sensitivity.
In addition, since the insulating layer 3 of the present invention has more excellent insulation, the thickness of the insulating layer 3 of the present invention can be thinner than that of the existing polyethylene insulating layer (XLPE) when satisfying the same insulation requirement, and the thinner thickness helps to reduce the outer diameter of the cable, save installation space, and reduce engineering cost.
Illustratively, an insulating layer 3 of 6-8mm thick may be applied at 66kV, an insulating layer 3 of 10-12mm thick may be applied at 110kV, an insulating layer 3 of 16-19mm thick may be applied at 220kV, an insulating layer 3 of 20-24mm thick may be applied at 330kV, an insulating layer 3 of 25-28mm thick may be applied at 500kV, an insulating layer 3 of 29-35mm thick may be applied at 640kV, and an insulating layer 3 of 36-40mm thick may be applied at 750 kV.
It is worth mentioning that the cable of the invention has high insulation temperature resistance (working temperature is from 90 ℃ to 120 ℃), the current-carrying capacity can be improved by 26%, and the cable has excellent transmission capacity. And because the insulating layer 3 is mainly PP, PP has the advantages of recoverability, low carbon and environmental protection.
In some embodiments of the present invention, the insulating layer 3 further includes, in parts by mass: 2-5 parts of an elastomer;
the elastomer is at least one selected from BR, SBR, EPR, EVA, EPMD, POE and SEBS.
In the present invention, when the insulating layer 3 further includes an elastomer, the elastomer can improve the toughness of the insulating layer 3, improve the low temperature resistance of the insulating layer 3, and further improve the toughness and the low temperature resistance of the cable.
Further, when the elastomer is selected from EPMD, EVA and SBR, and the mass ratio of the EPMD, the EVA and the SBR is (3-6): (1-3): (1-4), the elastomer has a synergistic effect, and the toughness and low temperature resistance of the insulating layer 3 can be maximally improved.
Illustratively, when the elastomer is an elastomer, the mass ratio of the EPMD, the EVA and the SBR is 5:2:3, the low-temperature impact test temperature of the insulating layer 3 can reach-80 ℃, which shows that the elastomer of the invention can improve the low-temperature resistance of the insulating layer 3.
In addition, under the environment of-40 ℃ to-30 ℃, taking a 500kV cable as an example, the cable is subjected to 3 bending tests under the condition that the outer diameter of the cable with the bending radius being 20 times, then partial discharge and voltage tests are carried out, and the cable is subjected to 3U 0 (870 kV) no discharge exceeding the claimed sensitivity was detected, 3U 0 (870 kV) and no insulation breakdown at 60min, which shows that the cable of the invention has excellent electrical insulation, mechanical property and low temperature resistance.
In some embodiments of the present invention, the inner shield layer 2 and/or the outer shield layer 4 comprise, in parts by mass:
100 parts of polypropylene;
2-5 parts of carbon black.
It is to be understood that the inner shield layer 2 of the present invention may include the above-described specific composition, the outer shield layer 4 of the present invention may include the above-described specific composition, and both the inner shield layer 2 and the outer shield layer 4 of the present invention may include the above-described specific composition.
In the present invention, when the inner shield layer 2 and/or the outer shield layer 4 both include the above-mentioned specific components, the inner shield layer 2 and/or the outer shield layer 4 have an excellent electrostatic magnetic shielding effect, and can improve the overall performance of the cable.
In some embodiments of the present invention, the inner shield layer 2 and/or the outer shield layer 4 further include, in parts by mass:
2-6 parts of a second antioxidant;
2-5 parts of a copper inhibitor.
It is understood that the inner shield layer 2 of the present invention may further include the second antioxidant and the copper resistant agent in the above-mentioned parts by mass, the outer shield layer 4 of the present invention may further include the second antioxidant and the copper resistant agent in the above-mentioned parts by mass, and both the inner shield layer 2 and the outer shield layer 4 of the present invention may include the second antioxidant and the copper resistant agent in the above-mentioned parts by mass.
In the present invention, when the inner shield layer 2 and/or the outer shield layer 4 further include the second antioxidant and the copper inhibitor in the above-mentioned parts by mass, the inner shield layer 2 and/or the outer shield layer 4 can have excellent oxidation resistance and mechanical properties.
Further, when the second antioxidant consists of antioxidant 1010 and antioxidant 330;
when the copper-resistant agent is 1024, the inner shield layer 2 and/or the outer shield layer 4 have more excellent oxidation resistance and mechanical properties, and the thermal aging resistance of the insulating layer 3 is also improved.
Particularly, in the inner shield layer 2 and/or the outer shield layer 4, the mass ratio of the antioxidant 1010 to the antioxidant 330 to the copper inhibitor 1024 is (1-5): (1-5): (1-4), the inner shield layer 2 and/or the outer shield layer 4 have more excellent oxidation resistance and mechanical properties.
In a specific embodiment, in the inner shield layer 2 and/or the outer shield layer 4, the mass ratio of the antioxidant 1010 to the antioxidant 330 to the copper inhibitor 1024 is 3.
It will be appreciated that, as shown in fig. 1, the cable of the invention may also comprise a buffer layer 5, a metal sheath 6 and an outer sheath 7; the buffer layer 5 is arranged outside the outer shielding layer 4 in a coated mode, the metal sheath 6 is arranged outside the buffer layer 5 in a coated mode, and the outer sheath 7 is arranged outside the metal sheath 6 in a coated mode. The buffer layer 5, the metal sheath 6 and the outer sheath 7 in the invention can be the buffer layer 5, the metal sheath 6 and the outer sheath 7 which are commonly used in the field.
In the present invention, the buffer layer 5 may be a buffer layer 5 commonly used in the art, for example, the material of the buffer layer 5 may be a low volume resistivity buffer zone, the volume resistivity of which is not more than 3 Ω. M, the surface resistance of which is not more than 50 Ω, and the thickness of the buffer layer 5 may be 1.5-2.5mm;
the metal sheath 6 can be at least one of a corrugated aluminum sheath, a smooth aluminum sheath, a corrugated copper sheath, a smooth copper sheath, a lead sheath and a non-magnetic stainless steel sheath, when the metal sheath 6 is the corrugated aluminum sheath or the smooth aluminum sheath, the thickness of the metal sheath 6 is 1.6-4.5mm, when the metal sheath 6 is the corrugated copper sheath or the smooth copper sheath, the thickness of the metal sheath 6 is 0.8-2.2mm, when the metal sheath 6 is the lead sheath, the thickness of the metal sheath 6 is 2.5-5mm, and when the metal sheath 6 is the non-magnetic stainless steel sheath, the thickness of the metal sheath 6 is 0.8-2.2mm;
the outer sheath 7 can be made of PE or PVC, the PE can be low-smoke halogen-free flame-retardant PE, and when the thickness of the outer sheath 7 is 3.5-4mm, the outer sheath can be suitable for 66kV voltage; when the thickness of the outer sheath 7 is 4-5.5mm, the voltage of 110kV can be applied; when the thickness of the outer sheath 7 is 5.5-6.5mm, the voltage of 220kV can be applied; when the thickness of the outer sheath 7 is 6-7mm, the voltage of 330kV can be applied; when the thickness of the outer sheath 7 is 7-8mm, the voltage of 500kV can be applied; when the thickness of the outer sheath 7 is 7.5-8.5mm, the voltage can be suitable for 640 kV; when the outer sheath 7 has a thickness of 750kV, it can be applied.
The second aspect of the present invention provides a preparation method of the cable, including the following steps:
and (3) sequentially coating the inner shielding layer 2, the insulating layer 3 and the outer shielding layer 4 outside the conductor 1 by using a three-layer co-extrusion machine head to obtain the PP insulated cable core.
Specifically, a conductor 1, an inner shielding layer material, an insulating layer material (the insulating layer material comprises 100 parts of polypropylene, 3-5 parts of a first antioxidant, the first antioxidant comprises antioxidant 1010, antioxidant 168 and antioxidant 330, the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is ((3-7): 1-3): 1-4)) and the outer shielding layer material are all placed at corresponding positions in an extruder, and a three-layer co-extruder head is used for sequentially coating the inner shielding layer 2, the insulating layer 3 and the outer shielding layer 4 on the outer portion of the conductor 1, so that the cable disclosed by the invention is obtained.
The preparation method of the cable can be used for preparing the cable, is simple and is suitable for wide popularization and application.
In the invention, the melting temperature of the insulating layer 3 comprising the specific components is 190-210 ℃, the extrusion temperature of the insulating layer 3 can be 155-255 ℃, so that the extrusion performance of the insulating layer 3 is improved, and further the comprehensive performance (ageing resistance, mechanical performance and the like) of the insulating layer 3 is improved.
In the present invention, when the inner shield layer 2 and/or the outer shield layer 4 includes polypropylene, carbon black, a second antioxidant and a copper inhibitor having a specific composition, the melting temperature of the inner shield layer and/or the outer shield layer is 180 to 210 ℃, and the extrusion temperature of the inner shield layer 2 and/or the outer shield layer 4 can be 155 to 255 ℃, so as to improve the extrusion performance of the inner shield layer 2 and/or the outer shield layer 4, and further improve the comprehensive performance (aging resistance, mechanical properties) of the inner shield layer 2 and/or the outer shield layer 4.
And the extrusion temperature of the insulating layer 3 and the extrusion temperatures of the inner shielding layer 2 and the outer shielding layer 4 can also ensure that the interface between the insulating layer 3 and the inner shielding layer 2 is smooth, the interface between the insulating layer 3 and the outer shielding layer 4 is smooth, and the electrical insulation strength of the cable is improved.
In the invention, when the 66kV-110kV wire core is extruded, a 330-mesh filter screen is selected for the extrusion of the insulating layer material, and a 110-mesh filter screen is selected for the extrusion of the inner shielding layer material and/or the outer shielding layer material; when the 220kV-330kV wire core is extruded, a filter screen with 430 meshes is selected for the extrusion of the insulating layer material, and a filter screen with 210 meshes is selected for the extrusion of the inner shielding layer material and/or the outer shielding layer material; when the 500kV-750kV wire core is extruded, a 530-mesh filter screen is selected for the extrusion of the insulating layer material, and a 310-mesh filter screen is selected for the extrusion of the inner shielding layer material and/or the outer shielding layer material. According to the invention, the filter screen is used for filtering the insulating layer material, the inner shielding layer material and the outer shielding layer material, so that the extrusion performance of the insulating layer 3, the inner shielding layer 2 and the outer shielding layer 4 can be improved, the purity of the insulating layer material during extrusion is improved, the extrusion pressure is increased, the extrusion colloid of the inner shielding layer 2 and/or the outer shielding layer 4 is smooth and well plasticized, the smoothness of the interface between the inner shielding layer 2 and/or the outer shielding layer 4 and the insulating layer 3 is enhanced, and the protrusion size of the interface is smaller than 10 mu m.
In some embodiments, the insulation layer material is filtered by a 530-mesh screen, 150 tons of insulation layer material is placed in an extruder head, the extrusion temperature is 155-255 ℃, the machine can be continuously started for 17 days, the extrusion pressure of the insulation layer 3 is uniform and stable (the extrusion pressure is increased by not more than 5%), and 100 tons of XLPE material is placed in an extruder, the machine can be continuously started for 10 days, which shows that the insulation layer material of the invention has excellent scorch resistance in the extruder.
In some embodiments of the present invention, when the ratio of the screw speed to the linear speed of the extruder is 8 to 12, the optimal extrusion performance can be achieved, so that the extrusion pressure fluctuation of the insulating layer, the inner shielding layer and the outer shielding layer is within 10 bar.
According to the invention, the insulating layer material, the inner shielding layer material and the outer shielding layer material which are specially composed are extruded under the specific process conditions (extrusion temperature, linear speed and screw rotation speed), the insulating layer material, the inner shielding layer material and the outer shielding layer material have good flowability, the formed eccentricity of the insulating layer 3, the inner shielding layer 2 and the outer shielding layer 4 is easy to control, the adsorption between the inner shielding layer 2 and the conductor 1 is strong, the adsorption between the insulating layer 3 and the inner shielding layer 2 is strong, and the adsorption between the outer shielding layer 4 and the insulating layer 3 is strong. In some embodiments, the maximum extrusion thickness of the insulating layer 3 may be 40mm, and the eccentricity of the insulating layer 3 may be controlled within 3%.
In some embodiments of the present invention, the method for preparing the cable further comprises sequentially performing an air cooling treatment and a water cooling treatment on the cable.
According to the invention, the cable formed by extrusion has a certain temperature, and can be subjected to air cooling treatment and water cooling treatment in sequence, and the matching of the air cooling treatment and the water cooling treatment can improve the cooling efficiency, save the cooling cost, gradually reduce the temperature of the cable, eliminate the stress of the insulating layer 3, the inner shielding layer 2 and the outer shielding layer 4 more uniformly, reduce the partial discharge condition of the cable and improve the insulating property of the cable.
In some embodiments, the gas cooling process may be performed using a nitrogen recycle cooling system. Can improve current vertical VCV production line of XLPE, increase first section nitrogen gas circulative cooling system between first section vulcanizes pipe and steam balance tank, carry out circulative cooling through high-pressure circulation fan and plate heat exchanger to nitrogen gas, and then realize carrying out air cooling to the cable and handle, the cable after air cooling handles can carry out the water-cooling.
In the invention, the insulation performance of the cable can be further improved by adjusting the temperature difference between the air cooling treatment and the water cooling treatment. Is as an exampleThe extruded 500kV cable is sequentially subjected to air cooling treatment and water cooling treatment, and when the temperature of the water cooling treatment is 120 ℃ lower than that of the air cooling treatment, the temperature is 1.5U 0 (U 0 290V) is 30pC, insulation breakdown; when the temperature of the water cooling treatment is 100 ℃ lower than that of the air cooling treatment, the temperature is 1.5U 0 (U 0 290V) is 24pC, insulation breakdown; when the temperature of the water cooling treatment is 70 ℃ lower than that of the air cooling treatment, 1.5U 0 (U 0 290V) is 13pC, discharge exists, and insulation is breakdown; when the temperature of the water cooling treatment was 40 ℃ lower than that of the air cooling treatment, discharge exceeding the background was not detected at 1.5U0 (U0: 290V), and insulation was not broken down. It can be shown that the cable has more excellent electrical insulation performance when the water cooling temperature is 40 c lower than the air cooling temperature.
The present invention will be further described with reference to specific examples.
Example 1
As shown in fig. 1, the cable of the present example was prepared by a method comprising the steps of:
sequentially coating an inner shielding layer 2, an insulating layer 3 and an outer shielding layer 4 outside a conductor 1 by using a three-layer co-extrusion machine head, and sequentially coating a buffer layer 5, a metal sheath 6 and an outer sheath 7 outside the outer shielding layer 4 to obtain a cable;
the insulating layer 3 is heated and extruded in seven zones, the temperature of the first zone is 168 ℃, the temperature of the second zone is 178 ℃, the temperature of the third zone is 185 ℃, the temperature of the fourth zone is 190 ℃, the temperature of the fifth zone is 200 ℃, the temperature of the sixth zone is 200 ℃, the temperature of the seventh zone is 200 ℃ (extrusion temperature), the inner shielding layer and the outer shielding layer are heated and extruded in four zones, the temperature of the first zone is 160 ℃, the temperature of the second zone is 170 ℃, the temperature of the third zone is 180 ℃, and the temperature of the fourth zone is 200 ℃ (extrusion temperature);
the ratio of the screw rotation speed to the linear speed of the extruder is 10;
sequentially carrying out air cooling treatment and water cooling treatment on the obtained cable, wherein the air cooling treatment is nitrogen cooling treatment, the temperature of the air cooling treatment is 75 ℃, and the temperature of the water cooling treatment is 40 ℃;
the cable of the present embodiment includes: the cable comprises a conductor 1, an inner shielding layer 2, an insulating layer 3, an outer shielding layer 4, a buffer layer 5, a metal sheath 6 and an outer sheath 7;
the inner shielding layer 2 is arranged outside the conductor 1 in a covering mode, the insulating layer 3 is arranged outside the inner shielding layer 2 in a covering mode, the outer shielding layer 4 is arranged outside the insulating layer 3 in a covering mode, the buffer layer 5 is arranged outside the outer shielding layer 4 in a covering mode, the metal sheath 6 is arranged outside the buffer layer 5 in a covering mode, and the outer sheath 7 is arranged outside the metal sheath 6 in a covering mode;
the conductor 1 is made of copper, and the outer diameter of the conductor 1 is 60.7mm;
the inner shielding layer 2 and the outer shielding layer 4 comprise the following components in parts by mass: 100 parts of polypropylene; 4 parts of carbon black; the thickness of the inner shielding layer 2 is 2.7mm, and the thickness of the outer shielding layer 4 is 1.6mm;
the insulating layer 3 comprises the following components in parts by weight: 100 parts of polypropylene; 3 parts of a first antioxidant; 5 parts of an elastomer; the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant 330, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is 5:2:3; the elastomer is a mixture of EPMD, EVA and SBR, and the mass part ratio of EPMD, EVA and SBR is 5:2:3;
the thickness of the insulating layer 3 is 28mm;
the buffer layer 5 is made of a buffer belt with low volume resistivity, the volume resistivity is 3 omega-m, the surface resistance is 50 omega, and the thickness of the buffer layer is 2.3mm;
the metal sheath 6 is an aluminum sheath, and the thickness of the metal sheath is 3.3mm;
the outer sheath 7 is made of low-smoke halogen-free flame-retardant PE (ST 12), and the thickness of the outer sheath is 8mm.
Example 2
The cable of this example was prepared in substantially the same manner as in example 1, except that the composition of the insulating layer 3 was different.
The cable of this example is substantially the same as example 1 except that the elastomer in the insulating layer 3 is EPMD.
Example 3
The cable of this example was prepared in substantially the same manner as in example 1, except that the compositions of the inner shield layer 2 and the outer shield layer 4 were different.
The cable of this embodiment is substantially the same as that of embodiment 1, except that,
the inner shielding layer 2 and the outer shielding layer 4 further comprise the following components in parts by mass: 6 parts of a second antioxidant; 2 parts of a copper-resistant agent; the second antioxidant consists of an antioxidant 1010 and an antioxidant 330; the copper resisting agent is 1024; the mass ratio of the antioxidant 1010 to the antioxidant 330 to the copper resisting agent 1024 is 3:3:2.
example 4
The cable of this example was prepared in substantially the same manner as in example 1, except that:
the ratio of the screw speed to the line speed of the extruder was 7.
The cable of this example was prepared by the method described above.
Example 5
The cable of this example was prepared in substantially the same manner as in example 1, except that no air cooling treatment was included.
The cable of this example was prepared by the method described above.
Comparative example 1
The cable of this comparative example was prepared in substantially the same manner as in example 1, except that the composition of the insulating layer 3 was different.
The cable of this comparative example is substantially the same as example 1 except that the insulating layer 3 includes, in parts by mass: 100 parts of polypropylene; 3 parts of a first antioxidant; the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant BHT, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant BHT is 1:4:2.
comparative example 2
The cable of this comparative example was prepared in substantially the same manner as in example 1, except that the composition of the insulating layer 3 was different.
The cable of this comparative example is substantially the same as example 1 except that the insulating layer 3 includes, in parts by mass: 100 parts of polypropylene; and 1010 parts of antioxidant.
Performance testing
The cables of the examples and comparative examples were subjected to performance tests, the test results are shown in table 1;
1. electrical insulation performance
Reference is made to GB/T1408.1-2016 insulating material Electrical Strength test method part 1: power frequency test, the insulation layer in the cable was cut into 0.2mm samples.
2. Mechanical Properties
Reference is made to GB/T2951.11-2008 "general test methods for Cable and Cable insulation and sheath materials part 11: general test methods-thickness and physical dimension measurements-mechanical property tests.
3. Low temperature impact
Refer to GB/T5470 & lt & gt determination of brittle temperature by plastic impact method.
TABLE 1
As can be seen from example 1 and comparative examples 1 to 2 in table 1, inclusion of an antioxidant of a specific composition in the insulation layer can improve mechanical properties as well as electrical insulation properties of the cable.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A cable is characterized by at least comprising a conductor, an inner shielding layer, an insulating layer and an outer shielding layer;
the inner shielding layer is arranged outside the conductor in a coated mode, the insulating layer is arranged outside the inner shielding layer in a coated mode, and the outer shielding layer is arranged outside the insulating layer in a coated mode;
wherein the insulating layer comprises the following components in parts by mass:
100 parts of polypropylene;
3-5 parts of a first antioxidant;
the first antioxidant consists of an antioxidant 1010, an antioxidant 168 and an antioxidant 330, and the mass ratio of the antioxidant 1010 to the antioxidant 168 to the antioxidant 330 is (3-7): (1-3): (1-4).
2. The cable of claim 1, wherein the insulation layer further comprises, in parts by mass: 2-5 parts of an elastomer;
the elastomer is selected from at least one of BR, SBR, EPR, EVA, EPMD, POE and SEBS.
3. The cable according to claim 2, wherein the elastomer is selected from the group consisting of EPMD, EVA and SBR, and the mass ratio of EPMD, EVA and SBR is (3-6): (1-3): (1-4).
4. A cable according to any one of claims 1 to 3, wherein the inner and/or outer shield comprises, in parts by mass:
100 parts of polypropylene;
2-5 parts of carbon black.
5. The cable according to claim 4, wherein the inner shield layer and/or the outer shield layer further comprises, in parts by mass:
2-6 parts of a second antioxidant;
2-5 parts of a copper inhibitor.
6. The cable of claim 5, wherein the second antioxidant consists of antioxidant 1010 and antioxidant 330;
the copper resistant agent is a copper resistant agent 1024.
7. The cable of claim 6, wherein the mass ratio of the antioxidant 1010, the antioxidant 330 and the copper inhibitor 1024 in the inner shield layer and/or the outer shield layer is (1-5): (1-5): (1-4).
8. A method for preparing a cable according to any one of claims 1 to 7, comprising the steps of:
and sequentially coating an inner shielding layer, an insulating layer and an outer shielding layer outside the conductor by using a three-layer co-extrusion machine head to obtain the cable.
9. The method of claim 8, wherein the insulating layer has an extrusion temperature of 155 to 255 ℃; and/or the presence of a gas in the atmosphere,
the extrusion temperature of the inner shielding layer and/or the outer shielding layer is 155-255 ℃; and/or the presence of a gas in the gas,
the ratio of the screw rotation speed to the linear speed of the extruder is 8-12.
10. The production method according to claim 8 or 9, wherein the cable is subjected to air cooling treatment and water cooling treatment in this order.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211531343.1A CN115762857A (en) | 2022-12-01 | 2022-12-01 | Cable and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211531343.1A CN115762857A (en) | 2022-12-01 | 2022-12-01 | Cable and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115762857A true CN115762857A (en) | 2023-03-07 |
Family
ID=85342426
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211531343.1A Pending CN115762857A (en) | 2022-12-01 | 2022-12-01 | Cable and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115762857A (en) |
-
2022
- 2022-12-01 CN CN202211531343.1A patent/CN115762857A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4363842A (en) | Elastomeric pre-stretched tubes for providing electrical stress control | |
| KR102005113B1 (en) | A insulation composition and an electric cable including the same | |
| CN102290155B (en) | Design method for insulation thickness of high-voltage cross-linked polyethylene direct current (DC) cable | |
| KR102664628B1 (en) | Semiconductive shielding composition | |
| CN103739930A (en) | Halogen-free flame-retardant heat-shrinkable busbar casing and preparation method thereof | |
| EP0035271B1 (en) | Elastomeric composition for providing electrical stress control | |
| CA2339541A1 (en) | An electric dc-cable with an insulation system comprising an extruded polyethylene composition and a method for manufacturing such cable | |
| CN103467839A (en) | Electric stress control heat shrink tube and manufacturing method thereof | |
| CN115762857A (en) | Cable and preparation method thereof | |
| CN204884602U (en) | Crosslinked polyethylene insulating material's cable for overhead insulated cable that contains graphite alkene | |
| CN216596986U (en) | Modified polypropylene insulation cable for rail transit | |
| CN109942933A (en) | A kind of direct current cables Insulation Material and preparation method thereof inhibiting space charge | |
| CN117059328A (en) | Power cable manufacturing method based on low-smoke halogen-free flame-retardant polyolefin sheath material | |
| CN103824642B (en) | There is the flexible power cable of resistance to humid-ageing exposure | |
| CN111524640A (en) | Insulated overhead cable | |
| CN109438807B (en) | Insulating material and preparation method and application thereof | |
| CN113698723A (en) | Polypropylene-based thermoplastic semiconductive shielding material for environment-friendly cable and preparation method thereof | |
| CN112029290A (en) | High-temperature vulcanized silicone rubber insulating material for composite insulator and preparation thereof | |
| CN111253755A (en) | High-mechanical-property insulating silicone rubber material and preparation method thereof | |
| CN113628782B (en) | Medium-voltage power flexible cable for wind power generation | |
| CN216596985U (en) | Modified polypropylene insulated wire core | |
| CN103724790A (en) | Conductor semiconducting shielding material applicable to four co-extrusion continuous vulcanization sets | |
| KR20130089217A (en) | Insulated electric wire | |
| CN218866736U (en) | Aluminum alloy conductor twin-core double-steel-tape armored photovoltaic cable | |
| CN213424623U (en) | Winding cable and transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |