A high voltage special-shaped conductor power cable

Abstract

The present invention relates to the technical field of power cables, and proposes a high-voltage special-shaped conductor power cable, which includes a special-shaped conductor, a semi-conductive layer, an inner shielding layer, an insulating layer, an outer shielding layer, a water-blocking layer, an aluminum jacket, an asphalt layer, an outer sheath layer and a conductive layer from the inside to the outside. The raw materials of the outer sheath layer include the following components by mass: 100 parts of polyethylene, 5 to 10 parts of a compatibilizer, 60 to 70 parts of a flame-retardant reinforcing agent, 0.5 to 1 part of an antioxidant, and 1 to 2 parts of a lubricant. The flame-retardant reinforcing agent includes glass microspheres and magnesium oxide whiskers in a mass ratio of 1:9 to 9:1. Through the above technical solution, the problems of poor flame retardancy and low mechanical strength of high-voltage special-shaped conductor power cables in the related art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of power cables, and in particular to a high-voltage special-shaped conductor power cable. Background Art

[0002] Special-shaped conductor power cables are power cables designed with special-shaped conductors. They have a more compact structure. Because of the special conductor structure, the outer diameter of the conductor is smaller while maintaining the same cross-sectional area, so that the power cable itself has a low resistivity and good conductivity. In addition, special-shaped conductor power cables also have good surface smoothness and creep resistance. These advantages can ensure the stable operation of the power system and make it widely used in various fields.

[0003] With the rapid development of the national economy, the demand for power infrastructure in various places is increasing. In order to reduce energy consumption in the transmission and distribution process, the voltage level of the cable is getting higher and higher, and the demand for high-voltage special-shaped conductor power cables is increasing. When people use high-voltage special-shaped conductor power cables, they are most concerned about safety. The flame retardancy and mechanical strength of the power cable itself are important parameters that reflect the safety. Compared with other performance, the flame retardancy and mechanical strength of high-voltage special-shaped conductor power cables on the market need to be further improved. Summary of the invention

[0004] The present invention provides a high-voltage special-shaped conductor power cable, which solves the problems of poor flame retardancy and low mechanical strength of the high-voltage special-shaped conductor power cable in the related art.

[0005] The technical solution of the present invention is as follows:

[0006] A high-voltage special-shaped conductor power cable comprises, from inside to outside, a special-shaped conductor, a semi-conductive layer, an inner shielding layer, an insulating layer, an outer shielding layer, a water-blocking layer, an aluminum sheath, an asphalt layer, an outer sheath layer and a conductive layer. The raw materials of the outer sheath layer comprise the following components in parts by mass: 100 parts of polyethylene, 5 to 10 parts of a compatibilizer, 60 to 70 parts of a flame-retardant reinforcing agent, 0.5 to 1 part of an antioxidant, and 1 to 2 parts of a lubricant. The flame-retardant reinforcing agent comprises glass microspheres and magnesium oxide whiskers in a mass ratio of 1:9 to 9:1.

[0007] As a further technical solution, the glass microspheres are modified glass microspheres, the magnesium oxide whiskers are modified magnesium oxide whiskers, and the modifiers of the modified glass microspheres and the modified magnesium oxide whiskers are each independently a saturated fatty acid.

[0008] The present invention modifies glass microspheres and magnesium oxide whiskers with saturated fatty acids respectively, thereby further improving the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0009] As a further technical solution, the modifier of the modified glass microspheres is a saturated fatty acid having 18 to 26 carbon atoms, and the modifier of the modified magnesium oxide whiskers is a saturated fatty acid having 10 to 18 carbon atoms.

[0010] In the present invention, the saturated fatty acid having 18 to 26 carbon atoms may be, for example, octadecanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, and hexacosanoic acid; the saturated fatty acid having 10 to 18 carbon atoms may be, for example, decanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, and octadecanoic acid.

[0011] The present invention limits the modifier of the modified glass microspheres to a saturated fatty acid having 18 to 26 carbon atoms, and the modifier of the modified magnesium oxide whisker to a saturated fatty acid having 10 to 18 carbon atoms, thereby further improving the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0012] As a further technical solution, the modifier of the modified glass microspheres is behenic acid, and the modifier of the modified magnesium oxide whiskers is tetradecanoic acid.

[0013] The invention adopts behenic acid modified glass microspheres and tetradic acid modified magnesium oxide whiskers, thereby further improving the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0014] As a further technical solution, the mass ratio of the modified glass microspheres to the modified magnesium oxide whiskers is 1:0.5-3.

[0015] The present invention limits the mass ratio of the modified glass microspheres to the modified magnesium oxide whiskers to 1:0.5-3, thereby further improving the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0016] As a further technical solution, the raw materials of the modified glass microspheres include a modifier and glass microspheres in a mass ratio of 1 to 5:100, and the raw materials of the modified magnesium oxide whiskers include a modifier and magnesium oxide whiskers in a mass ratio of 1 to 5:100.

[0017] As a further technical solution, the preparation method of the modified glass microspheres includes the following steps: after the modifier and the solvent are evenly mixed, they are further mixed with the glass microspheres, and dried to obtain modified glass microspheres; the preparation method of the modified magnesium oxide whiskers includes the following steps: after the modifier and the solvent are evenly mixed, they are further mixed with the magnesium oxide whiskers, and dried to obtain modified magnesium oxide whiskers.

[0018] As a further technical solution, the semi-conductive layer is a semi-conductive nylon tape.

[0019] As a further technical solution, the insulating layer is a cross-linked polyethylene insulating layer.

[0020] As a further technical solution, the compatibilizer may be any one or more compatibilizers in the art, for example, it may be one or both of maleic anhydride grafted polyethylene and maleic anhydride grafted polypropylene, preferably maleic anhydride grafted polyethylene.

[0021] As a further technical solution, the antioxidant may be any one or more antioxidants in the art, for example, it may be one or two of antioxidant 1010 and antioxidant 168.

[0022] As a further technical solution, the lubricant includes a mixture of one or both of methyl silicone oil and polyethylene wax and silicone powder.

[0023] The working principle and beneficial effects of the present invention are:

[0024] The present invention provides a high-voltage special-shaped conductor power cable, which comprises, from the inside to the outside, a special-shaped conductor, a semi-conductive layer, an inner shielding layer, an insulating layer, an outer shielding layer, a water-blocking layer, an aluminum jacket layer, an asphalt layer, an outer sheath layer and a conductive layer. Polyethylene, a compatibilizer, a flame-retardant reinforcing agent, an antioxidant and a lubricant are used as raw materials for the outer sheath layer. Glass microbeads and magnesium oxide whiskers are compounded as flame-retardant reinforcing agents to improve the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable. DETAILED DESCRIPTION

[0025] 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.

[0026] The parameters of the raw materials in the following examples and comparative examples are as follows:

[0027] The polyethylene is composed of HDPE DMDA-8008H and LLDPE DMDA8007 in a mass ratio of 70:30;

[0028] The compatibilizer is maleic anhydride grafted polyethylene GR202;

[0029] The glass beads are 400 mesh solid glass beads;

[0030] The MgO content in the magnesium oxide whisker is ≥99%, the diameter is 0.1~1.0μm, and the length is 5~100μm.

[0031] A high-voltage special-shaped conductor power cable comprises, from inside to outside, a special-shaped conductor, a semi-conductive nylon wrapping tape, a semi-conductive inner shielding layer, a cross-linked polyethylene insulation layer, a semi-conductive outer shielding layer, a semi-conductive buffer water-blocking tape, a corrugated aluminum sheath, asphalt, an outer sheath and a conductive layer. The raw materials of the outer sheath and the method of processing the outer sheath to the asphalt surface are as follows:

[0032] Example 1

[0033] S1, raw materials: 100 parts of polyethylene, 5 parts of compatibilizer, 6 parts of glass microspheres, 54 parts of magnesium oxide whiskers, 10100.5 parts of antioxidant, 0.5 parts of methyl silicone oil, and 0.5 parts of silicone powder;

[0034] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0035] Example 2

[0036] S1, raw materials: polyethylene 100 parts, compatibilizer 10 parts, glass microspheres 7 parts, magnesium oxide whiskers 63 parts, antioxidant 10100.5 parts, antioxidant 168 0.5 parts, polyethylene wax 1 part, silicone powder 1 part;

[0037] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0038] Example 3

[0039] S0, dissolving 3 parts of stearic acid in 500 parts of chloroform, adding 100 parts of glass microspheres, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified glass microspheres; dissolving 3 parts of stearic acid in 500 parts of chloroform, adding 100 parts of magnesium oxide whiskers, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified magnesium oxide whiskers;

[0040] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 6 parts of modified glass microspheres, 54 parts of modified magnesium oxide whiskers, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0041] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0042] Example 4

[0043] S0, dissolving 3 parts of n-decanoic acid in 500 parts of chloroform, adding 100 parts of glass microspheres, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified glass microspheres; dissolving 3 parts of n-decanoic acid in 500 parts of chloroform, adding 100 parts of magnesium oxide whiskers, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified magnesium oxide whiskers;

[0044] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 6 parts of modified glass microspheres, 54 parts of modified magnesium oxide whiskers, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0045] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0046] Example 5

[0047] S0, dissolving 3 parts of n-decanoic acid in 500 parts of chloroform, adding 100 parts of glass microspheres, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified glass microspheres; dissolving 3 parts of stearic acid in 500 parts of chloroform, adding 100 parts of magnesium oxide whiskers, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified magnesium oxide whiskers;

[0048] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 6 parts of modified glass microspheres, 54 parts of modified magnesium oxide whiskers, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0049] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0050] Example 6

[0051] S0, dissolving 3 parts of stearic acid in 500 parts of chloroform, adding 100 parts of glass microspheres, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified glass microspheres; dissolving 3 parts of n-decanoic acid in 500 parts of chloroform, adding 100 parts of magnesium oxide whiskers, modifying at 45°C for 30 minutes, filtering, and drying to obtain modified magnesium oxide whiskers;

[0052] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 6 parts of modified glass microspheres, 54 parts of modified magnesium oxide whiskers, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0053] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0054] Example 7

[0055] The only difference from Example 6 is that stearic acid is replaced by an equal amount of behenic acid.

[0056] Example 8

[0057] The only difference from Example 6 is that stearic acid is replaced by an equal amount of cerotic acid.

[0058] Example 9

[0059] The only difference from Example 7 is that n-decanoic acid is replaced by an equal amount of myristic acid.

[0060] Example 10

[0061] The only difference from Example 7 is that n-decanoic acid is replaced by an equal amount of stearic acid.

[0062] Embodiment 11

[0063] The only difference from Example 9 is: 15 parts of modified glass microspheres and 45 parts of modified magnesium oxide whiskers.

[0064] Example 12

[0065] The only difference from Example 9 is: 25 parts of modified glass microspheres and 35 parts of modified magnesium oxide whiskers.

[0066] Embodiment 13

[0067] The only difference from Example 9 is: 40 parts of modified glass microspheres and 20 parts of modified magnesium oxide whiskers.

[0068] Embodiment 14

[0069] The only difference from Example 9 is: 54 parts of modified glass microspheres and 6 parts of modified magnesium oxide whiskers.

[0070] Comparative Example 1

[0071] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 60 parts of glass beads, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0072] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0073] Comparative Example 2

[0074] S1, raw materials: 100 parts of polyethylene, 10 parts of compatibilizer, 60 parts of magnesium oxide whiskers, 0.5 parts of antioxidant 1010, 0.5 parts of antioxidant 168, 1 part of polyethylene wax, 1 part of silicone powder;

[0075] S2. After mixing the above raw materials evenly, transfer them to an extruder and melt extrude them on the asphalt surface.

[0076] After the outer sheath raw materials of Examples 1 to 14 and Comparative Examples 1 to 2 were mixed and uniformly melt-extruded to form the test samples, the tensile strength was tested with reference to the test method in GB / T 1040.1-2018 "Determination of tensile properties of plastics Part 1: General", wherein the test speed was 300 mm / min, and the test result was the average value of 5 samples; the oxygen index test was performed with reference to Method B in GB / T 2406.2-2009 "Determination of combustion behavior of plastics by oxygen index method Part 2: Room temperature test", and the test results are recorded in Table 1.

[0077] Table 1 Mechanical strength and flame retardancy of outer sheath

[0078]

[0079] It can be seen from Table 1 that the outer sheath provided by the present invention has a tensile strength of more than 16.7 MPa and an oxygen index of more than 27.3%, and has good mechanical strength and flame retardancy, thereby improving the mechanical strength and flame retardancy of the high-voltage special-shaped conductor power cable.

[0080] Compared with Comparative Examples 1-2, the tensile strength and oxygen index of the outer sheath obtained by adding glass microspheres and magnesium oxide whiskers in Example 1 are higher than those of Comparative Examples 1-2, indicating that the glass microspheres and magnesium oxide whiskers are compounded as flame-retardant reinforcing agents to improve the flame retardancy and mechanical strength of high-voltage special-shaped conductor power cables.

[0081] The tensile strength and oxygen index of the outer sheath obtained in Examples 3 to 10 are higher than those in Example 1, indicating that the glass microspheres and magnesium oxide whiskers are modified with saturated fatty acids, respectively, which further improves the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0082] The tensile strength and oxygen index of the outer sheath obtained in Example 6 are higher than those in Examples 3 to 5, indicating that the modifier of the modified glass microspheres is a saturated fatty acid with a carbon number of 18 to 26, and the modifier of the modified magnesium oxide whiskers is a saturated fatty acid with a carbon number of 10 to 18, which further improves the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0083] The tensile strength and oxygen index of the outer sheath obtained in Example 9 are higher than those in Examples 6 to 8 and Example 10, indicating that the use of behenic acid-modified glass microspheres and tetradecanoic acid-modified magnesium oxide whiskers further improves the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0084] The tensile strength and oxygen index of the outer sheath obtained in Examples 11 to 13 are higher than those in Example 9 and Example 14, indicating that the mass ratio of the modified glass microspheres to the modified magnesium oxide whiskers is 1:0.5 to 3, which further improves the flame retardancy and mechanical strength of the high-voltage special-shaped conductor power cable.

[0085] 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. A high-voltage special-shaped conductor power cable, comprising, from inside to outside, a special-shaped conductor, a semi-conductive layer, an inner shielding layer, an insulating layer, an outer shielding layer, a water-blocking layer, an aluminum jacket layer, an asphalt layer, an outer sheath layer and a conductive layer, characterized in that: The raw materials of the outer sheath layer include the following components in parts by mass: 100 parts of polyethylene, 5-10 parts of a compatibilizer, 60-70 parts of a flame retardant reinforcing agent, 0.5-1 part of an antioxidant, and 1-2 parts of a lubricant, wherein the flame retardant reinforcing agent includes glass microspheres and magnesium oxide whiskers in a mass ratio of 1:9-9:1; The glass microspheres are modified glass microspheres, and the magnesium oxide whiskers are modified magnesium oxide whiskers; The modifier of the modified glass microspheres is a saturated fatty acid with 18 to 26 carbon atoms, and the modifier of the modified magnesium oxide whiskers is a saturated fatty acid with 10 to 18 carbon atoms.

2. A high voltage special-shaped conductor power cable according to claim 1, characterized in that: The modifier of the modified glass microspheres is behenic acid, and the modifier of the modified magnesium oxide whiskers is tetradecanoic acid.

3. A high voltage special-shaped conductor power cable according to claim 2, characterized in that: The mass ratio of the modified glass microspheres to the modified magnesium oxide whiskers is 1:0.5-3.

4. A high voltage special-shaped conductor power cable according to claim 1, characterized in that: The raw materials of the modified glass microspheres include a modifier and glass microspheres in a mass ratio of 1 to 5:100, and the raw materials of the modified magnesium oxide whiskers include a modifier and magnesium oxide whiskers in a mass ratio of 1 to 5:

100.

5. A high voltage special-shaped conductor power cable according to claim 4, characterized in that: The preparation method of the modified glass microspheres comprises the following steps: after the modifier and the solvent are evenly mixed, the modifier and the glass microspheres are further mixed, and the mixture is dried to obtain the modified glass microspheres; the preparation method of the modified magnesium oxide whiskers comprises the following steps: after the modifier and the solvent are evenly mixed, the modifier and the magnesium oxide whiskers are further mixed, and the mixture is dried to obtain the modified magnesium oxide whiskers.

6. A high voltage special-shaped conductor power cable according to claim 1, characterized in that: The semi-conductive layer is a semi-conductive nylon tape.

7. A high voltage special-shaped conductor power cable according to claim 1, characterized in that: The insulating layer is a cross-linked polyethylene insulating layer.

8. A high voltage special-shaped conductor power cable according to claim 1, characterized in that: The lubricant comprises a mixture of one or both of methyl silicone oil and polyethylene wax and silicone powder.

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