Aluminum alloy medium-voltage power cable

Abstract

The invention relates to the technical field of power cables, and provides an aluminum alloy medium-voltage power cable which sequentially comprises a conductor, an insulating layer, an armor layer and a sheath layer from inside to outside, and the sheath layer is prepared from the following raw materials in parts by weight: 50-60 parts of metallocene polyethylene, 15-20 parts of ethylene-acrylic acid copolymer, 10-15 parts of filler, 5-8 parts of plasticizer, 1-2 parts of antioxidant and 5-10 parts of flame retardant; the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5 wt%-15 wt%. According to the technical scheme, the problems of low tensile strength and low elongation at break of the aluminum alloy medium-voltage power cable in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power cables, and in particular to an aluminum alloy medium-voltage power cable. Background Art

[0002] Aluminum alloy medium voltage power cable is a cable suitable for medium voltage power transmission that uses aluminum alloy as the conductor material. It is widely used in urban power grid transformation, industrial plant power supply and other fields. However, it still has some defects in terms of mechanical performance stability. In some application scenarios that need to withstand large tensile forces or mechanical stresses, such as long-distance overhead laying or laying in complex terrain, aluminum alloy cables may deform, break and other problems. During long-term operation, with changes in ambient temperature and repeated external forces, the mechanical properties of aluminum alloy cables may gradually decay, which not only affects the stability and reliability of power transmission, but also affects the installation and maintenance of cables, increasing construction difficulty and cost. Therefore, it is necessary to develop an aluminum alloy medium voltage power cable with high tensile strength and elongation at break. Summary of the invention

[0003] The present invention provides an aluminum alloy medium-voltage power cable, which solves the problems of low tensile strength and low elongation at break of the aluminum alloy medium-voltage power cable in the related art.

[0004] The technical solution of the present invention is as follows: The present invention provides an aluminum alloy medium-voltage power cable, which comprises, from the inside to the outside, a conductor, an insulating layer, an armor layer and a sheath layer, wherein the sheath layer comprises the following component raw materials in parts by weight: 50-60 parts of metallocene polyethylene, 15-20 parts of ethylene-acrylic acid copolymer, 10-15 parts of filler, 5-8 parts of plasticizer, 1-2 parts of antioxidant, and 5-10 parts of flame retardant; The acrylic acid content of the ethylene-acrylic acid copolymer is 7.5 wt % to 15 wt %.

[0005] As a further technical solution, the material of the conductor is aluminum alloy.

[0006] As a further technical solution, the insulating layer is a cross-linked polyethylene insulating layer.

[0007] As a further technical solution, the material of the armor layer is steel strip.

[0008] As a further technical solution, the acrylic acid content of the ethylene-acrylic acid copolymer is 9.5wt%~11wt%.

[0009] As a further technical solution, the filler includes one or more of aramid fiber, carbon fiber, and glass fiber.

[0010] As a further technical solution, the carbon fiber is a modified carbon fiber, the modifier of the modified carbon fiber is an aminopyridine ene compound, and the mass ratio of the modifier to the carbon fiber is 1-2:20.

[0011] In the present invention, aminopyridine olefin compounds are used to modify carbon fibers, thereby enhancing the interfacial bonding strength between the carbon fibers and the metallocene polyethylene matrix and the armor layer, promoting effective and uniform dispersion of stress, and enhancing the tensile strength and elongation at break of the aluminum alloy medium-voltage power cable.

[0012] As a further technical solution, the aminopyridine alkene compound includes one or more of 2-(2-phenylvinyl)-3-aminopyridine, 3-(2-amino-3-pyridyl)ethyl acrylate, and 3-(4-aminopyridin-3-yl)ethyl acrylate.

[0013] As a further technical solution, the preparation method of the modified carbon fiber comprises the following steps: dissolving the modifier in a solvent, adding the pretreated carbon fiber, ultrasonically impregnating, filtering and drying to obtain the modified carbon fiber.

[0014] As a further technical solution, at least one of the following technical features is also included: The plasticizer includes one or more of dioctyl phthalate, dibutyl phthalate, and dioctyl adipate; The antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076; The flame retardant includes one or both of magnesium hydroxide and aluminum hydroxide.

[0015] The present invention also provides a method for preparing an aluminum alloy medium-voltage power cable, comprising the following steps: S1, mixing the raw materials of the sheath layer uniformly, and extruding to obtain a sheath layer; S2. Wrap the insulation layer, armor layer and sheath layer around the conductor in sequence to obtain a cable.

[0016] As a further technical solution, the extrusion temperature is 150-180°C.

[0017] The working principle and beneficial effects of the present invention are: In the present invention, metallocene polyethylene is used as a matrix in the sheath layer of the aluminum alloy medium-voltage power cable, and ethylene-acrylic acid copolymer is added to improve the bonding strength between the sheath layer and the armor layer. By limiting the acrylic acid content of the ethylene-acrylic acid copolymer, the compatibility of the ethylene-acrylic acid copolymer and the metallocene polyethylene matrix is ​​improved, and the fluidity of the sheath layer system is improved, thereby improving the tensile strength and elongation at break of the aluminum alloy medium-voltage power cable. DETAILED DESCRIPTION

[0018] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the following examples and comparative examples: The conductor material is aluminum alloy; Insulation layer: cross-linked polyethylene insulation layer; Armor layer: steel belt; Metallocene polyethylene: Model CB1001, specific gravity 0.912g / cm 3 The manufacturer is Shenzhen Wansuyuan Rubber and Plastic Co., Ltd.

[0020] Example 1 A method for preparing an aluminum alloy medium-voltage power cable comprises the following steps: S1, weigh 50 parts of metallocene polyethylene, 15 parts of ethylene-acrylic acid copolymer, 10 parts of carbon fiber, 5 parts of dioctyl phthalate, 1 part of antioxidant 1010, and 5 parts of magnesium hydroxide, mix them evenly, extrude them at 150° C. to obtain a sheath layer, wherein the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5wt%; S2. Wrap the insulation layer, armor layer and sheath layer around the conductor in sequence to obtain a cable.

[0021] Example 2 A method for preparing an aluminum alloy medium-voltage power cable comprises the following steps: S1, weigh 55 parts of metallocene polyethylene, 18 parts of ethylene-acrylic acid copolymer, 12 parts of carbon fiber, 6 parts of dioctyl phthalate, 1.5 parts of antioxidant 168, and 8 parts of magnesium hydroxide, mix them evenly, extrude them at 170° C. to obtain a sheath layer, wherein the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5wt%; S2. Wrap the insulation layer, armor layer and sheath layer around the conductor in sequence to obtain a cable.

[0022] Example 3 A method for preparing an aluminum alloy medium-voltage power cable comprises the following steps: S1, weigh 60 parts of metallocene polyethylene, 20 parts of ethylene-acrylic acid copolymer, 15 parts of carbon fiber, 8 parts of dioctyl adipate, 2 parts of antioxidant 1076, and 10 parts of aluminum hydroxide, mix them evenly, extrude them at 180° C. to obtain a sheath layer, wherein the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5wt%; S2. Wrap the insulation layer, armor layer and sheath layer around the conductor in sequence to obtain a cable.

[0023] Example 4 Compared with Example 1, Example 4 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 9.5 wt %.

[0024] Example 5 Compared with Example 1, Example 5 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 10 wt %.

[0025] Example 6 Compared with Example 1, Example 6 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 11 wt %.

[0026] Example 7 Compared with Example 1, Example 7 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 15 wt %.

[0027] Example 8 The preparation method of modified carbon fiber comprises the following steps: dissolving 2 parts of 2-(2-phenylvinyl)-3-aminopyridine in 400 parts of dimethyl sulfoxide, soaking 20 parts of carbon fiber in 200 parts of nitric acid solution (concentration is 65wt%), soaking at 50°C for 2h, rinsing with water to neutrality, drying to obtain pretreated carbon fiber, adding the pretreated carbon fiber to a mixed solution of 2-(2-phenylvinyl)-3-aminopyridine and dimethyl sulfoxide, ultrasonically immersing in a water bath at 50°C for 2h, filtering and drying to obtain the modified carbon fiber.

[0028] Compared with Example 5, the difference of Example 8 is that the carbon fiber is replaced by an equal amount of modified carbon fiber obtained by the above preparation method.

[0029] Example 9 Compared with Example 8, Example 9 is different in that 2-(2-phenylvinyl)-3-aminopyridine is replaced with an equal amount of ethyl 3-(2-amino-3-pyridyl)acrylate.

[0030] Example 10 Compared with Example 8, the difference in Example 10 is that the amount of 2-(2-phenylvinyl)-3-aminopyridine added is 1 part.

[0031] Comparative Example 1 Compared with Example 1, Comparative Example 1 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 6 wt %.

[0032] Comparative Example 2 Compared with Example 1, Comparative Example 2 is different in that the acrylic acid content of the ethylene-acrylic acid copolymer is 20 wt %.

[0033] The sheath layers of the aluminum alloy medium voltage power cables prepared in Examples 1 to 10 and Comparative Examples 1 to 2 were tested according to the following method: 1. Tensile strength: According to GB / T 31840.2-2015 "Rated voltage 1kA (U m =1.2kV) to 35kA (U m =40.5kV) Aluminum alloy core extruded insulation power cable Part 2: Rated voltage 6kA (U m =7.2kV) to 30kA (U m =36kV) Cable》 to test the tensile strength of the sample.

[0034] 2. Elongation at break: According to GB / T 31840.2-2015 "Rated voltage 1kA (U m =1.2kV) to 35kA (U m =40.5kV) Aluminum alloy core extruded insulation power cable Part 2: Rated voltage 6kA (U m =7.2kV) to 30kA (U m =36kV) cable》, and test the elongation at break of the test sample.

[0035] The test results are shown in the following table: Table 1 Performance test results of the sheath layer of the aluminum alloy medium voltage power cables prepared in Examples 1 to 10 and Comparative Examples 1 to 2

[0036] Compared with Examples 1 to 7, the acrylic acid content of the ethylene-acrylic acid copolymer in Comparative Example 1 is 6wt%, and the acrylic acid content of the ethylene-acrylic acid copolymer in Comparative Example 2 is 20wt%. As a result, the tensile strength and elongation at break of Examples 1 to 7 are better than those of Comparative Examples 1 and 2, indicating that when the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5wt% to 15wt%, the tensile strength and elongation at break of the aluminum alloy medium voltage power cable can be improved. In Examples 1 and 4 to 7, ethylene-acrylic acid copolymers with different acrylic acid contents are added. As a result, the tensile strength and elongation at break of Examples 4 to 6 are better than those of Examples 1 and 7, indicating that when the acrylic acid content of the ethylene-acrylic acid copolymer is 9.5wt% to 11wt%, and preferably 10wt%, the tensile strength and elongation at break of the obtained aluminum alloy medium voltage power cable are better.

[0037] Compared with Example 5, Examples 8 to 10 added modified carbon fibers. As a result, the tensile strength and elongation at break of Examples 8 to 10 were better than those of Example 5, indicating that the addition of modified carbon fibers can improve the tensile strength and elongation at break of aluminum alloy medium-voltage power cables.

[0038] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An aluminum alloy medium voltage power cable, characterized in that: From the inside to the outside, it includes a conductor, an insulating layer, an armor layer and a sheath layer in sequence. The sheath layer includes the following component raw materials in parts by weight: 50-60 parts of metallocene polyethylene, 15-20 parts of ethylene-acrylic acid copolymer, 10-15 parts of filler, 5-8 parts of plasticizer, 1-2 parts of antioxidant, and 5-10 parts of flame retardant; the acrylic acid content of the ethylene-acrylic acid copolymer is 7.5wt%-15wt%.

2. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: The conductor is made of aluminum alloy.

3. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: The insulating layer is a cross-linked polyethylene insulating layer.

4. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: The material of the armor layer is steel strip.

5. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: The acrylic acid content of the ethylene-acrylic acid copolymer is 9.5 wt % to 11 wt %.

6. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: The filler includes one or more of aramid fiber, carbon fiber and glass fiber.

7. An aluminum alloy medium voltage power cable according to any one of claims 1 to 6, characterized in that: The carbon fiber is a modified carbon fiber, the modifier of the modified carbon fiber is an aminopyridine olefin compound, and the mass ratio of the modifier to the carbon fiber is 1 to 2:

20.

8. The aluminum alloy medium voltage power cable according to claim 7, characterized in that: The aminopyridine alkene compound includes one or more of 2-(2-phenylvinyl)-3-aminopyridine, 3-(2-amino-3-pyridyl)ethyl acrylate, and 3-(4-aminopyridin-3-yl)ethyl acrylate.

9. The aluminum alloy medium voltage power cable according to claim 7, characterized in that: The preparation method of the modified carbon fiber comprises the following steps: dissolving a modifier in a solvent, adding the pretreated carbon fiber, ultrasonically impregnating, filtering and drying to obtain the modified carbon fiber.

10. The aluminum alloy medium voltage power cable according to claim 1, characterized in that: Also includes at least one of the following technical features: The plasticizer includes one or more of dioctyl phthalate, dibutyl phthalate, and dioctyl adipate; The antioxidant includes one or more of antioxidant 1010, antioxidant 168, and antioxidant 1076; The flame retardant includes one or both of magnesium hydroxide and aluminum hydroxide.

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