High-tension high-strength composite superconducting wire and preparation method thereof

Abstract

The invention provides a high-tension high-strength composite superconducting wire and a preparation method thereof, the wire comprises a basalt fiber wire core, the outer edge of the basalt fiber wire core is wrapped with a copper or aluminum metal layer, and the metal layer is externally plated with a graphene layer or doped with graphene. The surface of a basalt fiber wire core is wrapped with a metal layer, the basalt fiber wire core is pulled in the vertical direction to rapidly pass through a metal plating area and a cooling area upwards, and after high-temperature liquid metal is attached to the surface of the basalt fiber wire core, the high-temperature liquid metal enters the cooling area to be rapidly cooled and solidified into the metal layer wrapping the surface of the basalt fiber wire core. And finally, coating the graphene layer on the surface of the metal layer. According to the invention, the insulated basalt fiber is used as the wire core, the metal layer at the outer edge of the basalt fiber is used for transmitting electric energy, the overall weight is one tenth of that of a traditional copper core cable, the tensioning force is large, heat dissipation is fast, the use number of towers can be greatly reduced during long-distance laying, and the laying cost of a power grid is reduced.

Description

Technical Field

[0001] The invention relates to the field of power cables, in particular to a high-tension high-strength composite superconducting wire and a preparation method thereof. Background Art

[0002] The use of power cables has a history of more than 100 years. In 1879, American inventor TA Edison wrapped jute around a copper rod and inserted it into an iron pipe, and then filled it with an asphalt mixture to make a cable. He laid this cable in New York, pioneering underground power transmission. The following year, the British Callender invented asphalt-impregnated paper insulated power cable. In 1889, the British SZ Ferranti laid a 10 kV oil-impregnated paper insulated cable between London and Deptford. In 1908, the UK built a 20 kV cable network. Power cables are being used more and more widely. In 1911, Germany laid a 60 kV high-voltage cable, starting the development of high-voltage cables. In 1913, German M. Hochstadt developed a phase-shielded cable, which improved the electric field distribution inside the cable and eliminated the tangent stress on the insulation surface, becoming a milestone in the development of power cables. In 1952, Sweden laid a 380 kV ultra-high voltage cable in a northern power plant, realizing the application of ultra-high voltage cables. By the 1980s, 1100 kV and 1200 kV ultra-high voltage power cables had been produced.

[0003] my country's current electricity price is $0.08 per kilowatt-hour, making it one of the countries with the lowest electricity prices in the world. Due to abundant natural resources, the main factor restricting electricity prices is the loss of high-voltage cables during transmission. The components of high-voltage cables from the inside to the outside include: conductor, insulation, inner sheath, filler (armor), and outer insulation. Due to the excellent conductivity of copper conductors, more and more projects use copper core power cables as the main trunk of the power supply system. The external armor structure is usually made of twisted pair wires made of cold-drawn steel wire and multiple strands of steel bars. Existing high-voltage cables have the following defects: 1. The tension force is insufficient and the weight is high. In order to avoid excessive deflection of the cable bridge, the span between two power towers is usually 100-300m. For long-distance power transmission, a large number of towers need to be laid, which is costly.

[0004] 2. Both copper wire and steel stranded wire expand and contract due to heat. When laying cables, a certain amount of reserve must be made based on the degree of thermal expansion and contraction, resulting in waste of materials.

[0005] 3. It generates a lot of heat when powered on, resulting in large energy loss.

[0006] If the above defects can be solved, electricity prices can be further reduced, electricity exports can be realized, and global power grid construction can be achieved.

[0007] Basalt fiber has the characteristics of high strength, high modulus, high and low temperature resistance, chemical corrosion resistance, UV resistance, low moisture absorption, sound insulation, heat insulation, excellent environmental resistance, etc. It can be widely used in civil engineering, transportation, energy and environmental protection, automobiles and ships, aerospace, petrochemicals, weapons and equipment, etc. Basalt fiber is made of volcanic rock, which is the only pure natural non-synthetic raw material among all high-tech fibers; its production process is short and almost no "three wastes" are produced. The energy consumption is the lowest among all high-tech fibers (the energy consumption of basalt fiber is 1 / 16 of that of carbon fiber). It is a typical resource-saving and environmentally friendly green high-tech fiber.

[0008] In the prior art, there are examples of applying basalt fiber in cables. Usually, basalt fiber is used to replace steel strands as armor layers, thereby reducing the weight of the cable, and the internal core is still made of copper. Summary of the invention

[0009] In order to solve the problems of the prior art, the present invention provides a high-tensile force and high-strength composite superconducting wire and a preparation device and method thereof. Insulated basalt fiber is used as the wire core, and the metal layer on the outer edge of the basalt fiber is used to transmit electrical energy. The overall weight is one tenth of that of a traditional copper core cable. The tensile force is large, the heat dissipation is fast, and the number of poles and towers used can be greatly reduced when laid over long distances, thereby reducing the laying cost of the power grid.

[0010] The invention provides a high-tensile force and high-strength composite superconducting wire, comprising a basalt fiber core, the outer edge of the basalt fiber core is wrapped with a copper or aluminum metal layer, the metal layer is plated with a graphene layer or the metal layer is doped with graphene.

[0011] The present invention also provides a method for preparing a high-tensile force and high-strength composite superconducting wire, comprising the following steps: 1) Preparation of basalt fiber core; 2) Wrapping a metal layer on the surface of the basalt fiber core: Pull the basalt fiber core in the vertical direction, so that it quickly passes through the metal plating area and the cooling area. After the high-temperature liquid metal is coated on the surface of the basalt fiber core, it enters the cooling area and is rapidly cooled and solidified into a metal layer wrapped on the surface of the basalt fiber core; 3) coating a graphene layer on the surface of the metal layer or forming a metal and graphene doped layer on the surface of the metal layer.

[0012] 3. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 2, characterized in that: the basalt fiber core in step 1) is prepared by a vertical gravity tensioning method.

[0013] The preparation device used in step 2) includes several layers of vertically distributed processing areas, a coaxial processing channel is opened in the center of the processing area, and a traction device vertically pulls the basalt fiber core through the processing channels of each processing area in turn to complete the processing; the processing area includes a high-temperature coating area and a low-temperature cooling area, the high-temperature coating area is a cavity with a processing channel opened in the center, and high-temperature liquid metal is passed into the cavity.

[0014] Further improvement, the process of wrapping the metal layer on the surface of the basalt fiber core in step 2) is as follows: 2.1) Clamp the basalt fiber core and make it pass through the high-temperature coating area and the low-temperature cooling area from the bottom and enter the traction device; 2.2) Liquid metal is injected into the cavity of the high-temperature coating zone, and coolant is introduced into the low-temperature cooling zone. At the same time, the traction device pulls the basalt fiber core to rise rapidly; 2.3) The liquid metal in the cavity is discharged before the lower end of the basalt fiber core approaches the high-temperature coating area, and the parts at both ends that are not wrapped with the metal layer are cut off.

[0015] Further improvement, the liquid metal described in step 2.2) is liquid aluminum or liquid copper.

[0016] Further improvement, the coolant in step 2.2) is circulating cooling water or liquid nitrogen.

[0017] Further improvement, the process of coating the graphene layer in step 3) adopts physical coating method or chemical vapor deposition method. The specific method of forming the metal and graphene doping layer on the surface of the metal layer is to grow metal-doped graphene on the surface of the metal layer by plasma chemical vapor deposition method using carbon precursor, metal precursor and group VI precursor.

[0018] The beneficial effects of the present invention are: 1. Using insulated basalt fiber as the core, and using the metal layer on the outer edge of the basalt fiber to transmit electrical energy, it subverts the structural form of traditional cables.

[0019] 2. Since basalt fiber is light in weight and has high hardness and tensile strength, it does not require an additional armor layer. The overall weight of the cable is one-tenth of that of traditional copper-core cables, and its expansion resistance is improved tenfold. During the laying of a power grid over the same distance, the number of poles and towers required is only one-tenth of that of conventional copper-core cables, which greatly reduces the cost of laying the power grid, is conducive to exporting my country's high-quality and low-cost electricity to the world, and realizing the laying of a global power grid.

[0020] 3. The thermal expansion and contraction coefficient of steel strand is usually 1.2×10 -5 / ℃, the thermal expansion coefficient of basalt fiber is 6.5~8.0×10 -6 / ℃, the thermal expansion coefficient of basalt fiber is much lower than that of existing conductors and is almost unaffected by daily temperature changes. There is no need to make a large amount of provision for thermal expansion and contraction, thus saving materials.

[0021] 4. The graphene layer has the ability to achieve superconductivity. The conductivity test shows that when the copper foil on the surface of the basalt fiber is covered with graphene, the conductivity of the composite material is significantly improved, reaching 59.32×10 6 S・m -1 , 7.83% higher than the original copper foil and 4.46% higher than the annealed copper foil. The Hall effect test system measured and found that annealing would reduce the carrier density of the copper foil, but when graphene grew on the surface of the annealed copper foil, the carrier density first increased sharply, and then gradually decreased as the graphene completely covered the copper foil surface; at the same time, the carrier mobility increased with the extension of the graphene growth time. DETAILED DESCRIPTION

[0022] 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.

[0023] The invention provides a high-tensile force and high-strength composite superconducting wire, comprising a basalt fiber core, the outer edge of the basalt fiber core is wrapped with a copper or aluminum metal layer, the metal layer is plated with a graphene layer or the metal layer is doped with graphene.

[0024] The present invention also provides a method for preparing a high-tensile force and high-strength composite superconducting wire, comprising the following steps: 1) The basalt fiber core was prepared by vertical gravity tensioning method.

[0025] 2) Wrapping a metal layer on the surface of the basalt fiber core: Pull the basalt fiber core in the vertical direction, so that it quickly passes through the metal plating area and the cooling area upward. After the high-temperature liquid metal is coated on the surface of the basalt fiber core, it enters the cooling zone and is rapidly cooled and solidified into a metal layer wrapped on the surface of the basalt fiber core.

[0026] The equipment used is as follows: it includes several layers of vertically distributed processing areas, a coaxial processing channel is opened in the center of the processing area, and a traction device vertically pulls the basalt fiber core through the processing channels of each processing area in turn to complete the processing; the processing area includes a high-temperature coating area and a low-temperature cooling area, the high-temperature coating area is a cavity with a processing channel opened in the center, and high-temperature liquid metal is passed into the cavity.

[0027] The specific preparation process is as follows: 2.1) Clamp the basalt fiber core and make it pass through the high-temperature coating area and the low-temperature cooling area from the bottom and enter the traction device; 2.2) Liquid metal (copper or aluminum) is injected into the cavity of the high-temperature coating zone, and coolant (circulating cooling water or liquid nitrogen) is introduced into the low-temperature cooling zone. At the same time, the traction device pulls the basalt fiber core to rise rapidly; 2.3) The liquid metal in the cavity is discharged before the lower end of the basalt fiber core approaches the high-temperature coating area, and the parts at both ends that are not wrapped with the metal layer are cut off.

[0028] 3) A graphene layer is coated on the surface of the metal layer by physical coating or chemical vapor deposition, or a metal-doped graphene is grown on the surface of the metal layer by plasma chemical vapor deposition using a carbon precursor, a metal precursor and a Group VI precursor.

[0029] The conductivity test shows that when the copper foil on the surface of basalt fiber is covered with graphene, the conductivity of the composite material is significantly improved to 59.32×10 6 S・m -1 , 7.83% higher than the original copper foil and 4.46% higher than the annealed copper foil. The Hall effect test system measured and found that annealing would reduce the carrier density of the copper foil, but when graphene grew on the surface of the annealed copper foil, the carrier density first increased sharply, and then gradually decreased as the graphene completely covered the copper foil surface; at the same time, the carrier mobility increased with the extension of the graphene growth time.

[0030] The basalt fiber in this application can also be replaced by ceramic carbon fiber. The melting point of ceramic carbon fiber is generally above 2000 degrees Celsius. Compared with basalt fiber, it has higher high temperature resistance, the metal plating stage is easier than basalt fiber, and the tension force is also higher than basalt fiber. However, it is expensive. One kilogram of ceramic carbon fiber costs about 50,000 yuan. At the current cost, it can only be used in laboratories and cannot be used for large-scale power grid laying.

[0031] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field within the technical scope disclosed by the present invention, for ordinary technicians in the technical field, can easily think of changes or replacements, without departing from the principle of the present invention, should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A high-tensile force and high-strength composite superconducting wire, characterized in that: The utility model comprises a basalt fiber core, the outer edge of the basalt fiber core is wrapped with a copper or aluminum metal layer, the metal layer is plated with a graphene layer or the metal layer is doped with graphene.

2. A method for preparing a high-tensile-force and high-strength composite superconducting wire, characterized in that The following steps are involved: 1) Preparation of basalt fiber core; 2) Wrapping a metal layer on the surface of the basalt fiber core: Pull the basalt fiber core in the vertical direction, so that it quickly passes through the metal plating area and the cooling area. After the high-temperature liquid metal is coated on the surface of the basalt fiber core, it enters the cooling area and is rapidly cooled and solidified into a metal layer wrapped on the surface of the basalt fiber core; 3) coating a graphene layer on the surface of the metal layer or forming a metal and graphene doped layer on the surface of the metal layer.

3. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 2, characterized in that: The basalt fiber core described in step 1) is prepared by a vertical gravity tensioning method.

4. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 2, characterized in that: The preparation device used in step 2) includes several layers of vertically distributed processing areas, a coaxial processing channel is opened in the center of the processing area, and a traction device vertically pulls the basalt fiber core through the processing channels of each processing area in turn to complete the processing; the processing area includes a high-temperature coating area and a low-temperature cooling area, the high-temperature coating area is a cavity with a processing channel opened in the center, and high-temperature liquid metal is passed into the cavity.

5. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 4, characterized in that: The process of wrapping the metal layer on the surface of the basalt fiber core in step 2) is as follows: 2.1) Clamp the basalt fiber core and make it pass through the high-temperature coating area and the low-temperature cooling area from the bottom and enter the traction device; 2.2) Liquid metal is injected into the cavity of the high-temperature coating zone, and coolant is introduced into the low-temperature cooling zone. At the same time, the traction device pulls the basalt fiber core to rise rapidly; 2.3) The liquid metal in the cavity is discharged before the lower end of the basalt fiber core approaches the high-temperature coating area, and the parts at both ends that are not wrapped with the metal layer are cut off.

6. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 5, characterized in that: The liquid metal described in step 2.2) is liquid aluminum or liquid copper.

7. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 5, characterized in that: The coolant in step 2.2) is circulating cooling water or liquid nitrogen.

8. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 2, characterized in that: The graphene layer coating process described in step 3) adopts a physical coating method or a chemical vapor deposition method.

9. The method for preparing a high-tensile force and high-strength composite superconducting wire according to claim 2, characterized in that: Step 3) The specific method of forming the metal and graphene doped layer on the surface of the metal layer is to grow metal-doped graphene on the surface of the metal layer by plasma chemical vapor deposition using a carbon precursor, a metal precursor and a Group VI precursor.