Aluminum alloy core for photovoltaic power generation and radial water-blocking high-voltage cable thereof

Abstract

The invention discloses an aluminum alloy core for photovoltaic power generation and a radial water-blocking high-voltage cable thereof, and relates to the technical field of cables, and the cable comprises a cable core, an isolation layer, an interlocking armor layer, an aluminum plastic bonding waterproof layer and an outer sheath layer which are arranged from inside to outside; wherein the cable core comprises a cable core which is composed of an aluminum alloy core, a conductor shielding layer, an insulating layer, an insulating shielding layer and a composite shielding structure in sequence from inside to outside, and the conductor shielding layer, the insulating layer and the insulating shielding layer are wrapped outside an aluminum alloy core conductor by a three-layer co-extrusion process; the isolating layer is a hydrophobic polyethylene layer which wraps the outer side of the cable core in the radial direction, and water blocking yarn is filled between the cable core and the isolating layer. The aluminum alloy core has good tensile strength and elongation and can keep low resistivity, and the overall structure of the radial water-blocking high-voltage cable has a good water-blocking effect.

Description

Technical Field

[0001] The invention relates to the technical field of cables, and in particular to an aluminum alloy core for photovoltaic power generation and a radial water-blocking high-voltage cable thereof. Background Art

[0002] At present, most traditional cables use round single-wire stranded conductors. The filling factor of the stranded conductor is 0.75, and the filling factor reaches 0.82-0.92 after compression. As a result, the outer diameter of the conductor is too large, which increases the amount of insulation, filling, armor and sheath materials, thereby increasing production costs and failing to achieve environmental protection. In addition, the tensile strength of aluminum alloy wires is low. If steel core is added to form steel core aluminum stranded wire, this will increase the weight of the wires and cables, increase the resistivity, and reduce the corrosion resistance, resulting in increased pole load, increased line loss, and shortened service life.

[0003] In addition, when laying cables, they often need to cross roads, bridges, culverts, etc. Due to weather, geography and other reasons, a lot of water often accumulates around the cables. When the water seeps into the cables, it is easy to form water trees, which will seriously reduce the electrical performance of the cables and eventually cause cable breakdown, affecting the safe and stable operation of the power grid, causing corrosion of metal layers such as steel and copper belts, reducing insulation performance, and causing single-phase or three-phase faults, or even explosions and injuries. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide an aluminum alloy core for photovoltaic power generation and a radial water-blocking high-voltage cable thereof, which has good tensile strength and elongation, can also maintain a low resistivity, and has a good water-blocking effect.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] The present invention provides a radial water-blocking high-voltage cable for photovoltaic power generation, which comprises a cable core, an isolation layer, an interlocking armor layer, an aluminum-plastic bonding waterproof layer and an outer sheath layer arranged from inside to outside;

[0007] The cable core includes an aluminum alloy core, a conductor shielding layer, an insulating layer, an insulating shielding layer, and a composite shielding structure from the inside to the outside. The conductor shielding layer, the insulating layer, and the insulating shielding layer are coated on the outside of the aluminum alloy core conductor by a three-layer co-extrusion process.

[0008] The isolation layer is a hydrophobic polyethylene layer radially coated on the outside of the cable core, and water-blocking yarn is filled between the cable core and the isolation layer.

[0009] Preferably, the aluminum-plastic adhesive waterproof layer is formed by bonding a longitudinally wrapped double-sided plastic-coated aluminum tape and a polyethylene outer sheath, the double-sided plastic-coated aluminum tape has a nominal thickness of at least 0.20 mm, and the bare aluminum tape has a nominal thickness of not less than 0.15 mm;

[0010] The double-sided plastic-coated aluminum tape is completely and longitudinally wrapped outside the cable core, the longitudinal overlapping width is not less than 6mm, and the longitudinal overlapping width is not less than 20% of the circumference of the longitudinally wrapped wire core.

[0011] Preferably, the cable core is formed by twisting three cable cores.

[0012] Preferably, the composite shielding structure is a double-layer composite structure of soft fine copper wire layer and soft copper tape;

[0013] Among them, the soft fine copper wire layer is made of 0.51mm soft fine copper wire and is evenly wound around the insulating shielding layer of the cable core, and the soft copper tape is overlapped and spirally wrapped outside the soft fine copper wire layer; the number of the soft fine copper wires is determined according to the shielding cross-sectional area, and the shielding cross-sectional area is determined according to the cable fault current.

[0014] The present invention also provides an aluminum alloy core for photovoltaic power generation, which is applied to the above-mentioned radial water-blocking high-voltage cable for photovoltaic power generation. The chemical composition mass ratio of the aluminum alloy core is as follows:

[0015] Iron 0.50-0.60%, boron 0.04-0.06%, silicon 0.10%, copper 0.10-0.15%, magnesium 0.01%, zinc 0.01-0.05%, cerium 0.020-0.025%, lanthanum 0.010-0.015%, and the balance is aluminum and inevitable impurities.

[0016] Furthermore, the mass percentage of aluminum in the chemical composition of the aluminum alloy core is 99.06-99.11%.

[0017] Furthermore, the chemical composition mass ratio of the aluminum alloy core is: 0.60% iron, 0.04% boron, 0.10% silicon, 0.15% copper, 0.01% magnesium, 0.01% zinc, 99.06% aluminum, 0.020% cerium, and 0.010% lanthanum.

[0018] Furthermore, the aluminum alloy core is firstly melted and rolled into an aluminum alloy rod through aluminum ingot, and then the aluminum alloy rod is drawn into a special-shaped aluminum alloy single wire, and finally the special-shaped aluminum alloy single wire is twisted into a cable core.

[0019] Furthermore, the special-shaped aluminum alloy single wire is twisted into a circular structure through multiple strands of tight compression, and each layer is twisted in forward and reverse directions.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] On the one hand, the cable of the present invention is provided with a cable core, a waterproof isolation layer, an interlocking armor layer, an aluminum-plastic bonding waterproof layer and an outer sheath layer from the inside to the outside. Since the isolation layer is radially coated on the cable core of the cable with hydrophobic polyethylene and is locked by the interlocking armor layer, from an axial point of view, it is like a metal tube sleeved outside the cable core, blocking the external water from entering the cable core. In addition, the cable core is also filled with water-blocking yarn, which can make the interlocking armor layer, the waterproof isolation layer and the water-blocking yarn tighter, serving as an inner waterproof layer; and in terms of longitudinal waterproofness, the present invention also uses a tightly wrapped aluminum-plastic bonding waterproof layer and an outer sheath layer as an outer waterproof layer, so that the present invention has good waterproofness in both longitudinal and radial directions through the cooperation of the inner waterproof layer and the outer waterproof layer.

[0022] On the other hand, the aluminum alloy core of the cable in the present invention has good tensile strength, resistivity, etc., and has excellent performance. It also uses special-shaped aluminum alloy single wires twisted into a cable core conductor with a smaller outer diameter, which is beneficial to reducing the cable production cost and reducing the amount of materials used in the subsequent processes to cover the previous processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the cross-sectional structure of the present invention;

[0024] Figure numerals: 10, aluminum alloy core, 21, conductor shielding layer, 22, insulation layer, 23, insulation shielding layer, 30, composite shielding structure, 31, soft copper tape, 32, soft fine copper wire layer, 40, interlocking armor layer, 50, aluminum-plastic bonding waterproof layer, 60, outer sheath layer, 70, isolation layer, 80 water-blocking yarn. DETAILED DESCRIPTION

[0025] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0026] Example 1

[0027] The present invention provides a radial water-blocking high-voltage cable for photovoltaic power generation, which comprises a cable core, an isolation layer 70, an interlocking armor layer 40, an aluminum-plastic bonding waterproof layer 50 and an outer sheath layer 60 arranged from inside to outside;

[0028] The cable core includes a cable core 100 which is composed of an aluminum alloy core 10, a conductor shielding layer 21, an insulating layer 22, an insulating shielding layer 23, and a composite shielding structure 30 from inside to outside. The conductor shielding layer 21, the insulating layer 22, and the insulating shielding layer 23 are coated on the outside of the aluminum alloy core conductor 10 by a three-layer co-extrusion process;

[0029] The isolation layer 70 is a hydrophobic polyethylene layer radially coated on the outside of the cable core, and a water-blocking yarn 80 is filled between the cable core and the isolation layer 70 .

[0030] It is worth noting that since the isolation layer is radially covered on the cable core of the cable with a hydrophobic polyethylene sheath and is locked by the interlocking armor layer 40, from an axial point of view, it is like a metal tube sleeved outside the cable core, blocking external water from entering the cable core. In addition, the cable core is also filled with water-blocking yarn 80, which can make the interlocking armor layer 40, the waterproof isolation layer 70 and the water-blocking yarn 80 closer, and together serve as an inner waterproof layer, achieving a good radial water-blocking effect.

[0031] In order to better achieve the longitudinal waterproof effect of this embodiment, the aluminum-plastic bonding waterproof layer 50 is formed by bonding a longitudinally wrapped double-sided plastic-coated aluminum tape and a polyethylene outer sheath. The aluminum-plastic bonding waterproof layer 50 and the outer sheath layer 60 together constitute the outer waterproof layer in this embodiment. The nominal thickness of the double-sided plastic-coated aluminum tape is at least 0.20 mm, and the nominal thickness of the bare aluminum tape is not less than 0.15 mm.

[0032] The double-sided plastic-coated aluminum tape is completely and longitudinally wrapped outside the cable core, the longitudinal overlapping width is not less than 6mm, and the longitudinal overlapping width is not less than 20% of the circumference of the longitudinally wrapped wire core.

[0033] Therefore, this embodiment has good waterproof properties in both longitudinal and radial directions through the cooperation between the inner waterproof layer and the outer waterproof layer.

[0034] In this embodiment, the cable core is formed by twisting three cable cores 100. The water-blocking yarn 80 is filled in the twisting gap and between the cable core 100 and the isolation layer 70, which can not only support and buffer the cable core 100 and the isolation layer 70, but also have good water-blocking properties.

[0035] In this embodiment, the composite shielding structure 30 is a double-layer composite structure of a soft fine copper wire layer 32 and a soft copper tape 31;

[0036] Among them, the soft fine copper wire layer 32 uses 0.51mm soft fine copper wires to be equally spaced and wound around the insulating shielding layer 23 of the cable core, and the soft copper tape 31 is overlapped and spirally wrapped around the soft fine copper wire layer 32; the number of the soft fine copper wires is determined according to the shielding cross-sectional area, and the shielding cross-sectional area is determined according to the cable fault current.

[0037] Example 2

[0038] The present invention also provides an aluminum alloy core for photovoltaic power generation, which is applied to the above-mentioned radial water-blocking high-voltage cable for photovoltaic power generation. The chemical composition mass ratio of the aluminum alloy core is as follows:

[0039] Iron 0.60%, boron 0.04%, silicon 0.10%, copper 0.15%, magnesium 0.01%, zinc 0.01%, aluminum 99.06%, cerium 0.020%, lanthanum 0.010%.

[0040] In this embodiment, the aluminum alloy core 10 is firstly melted and rolled into an aluminum alloy rod through aluminum ingot, and then the aluminum alloy rod is drawn into a special-shaped aluminum alloy single wire, and finally the special-shaped aluminum alloy single wire is twisted into a cable core.

[0041] In this embodiment, the special-shaped aluminum alloy single wire is twisted into a circular structure through multiple strands, and each layer is twisted in the forward and reverse directions.

[0042] The aluminum alloy rod material prepared based on the chemical composition mass ratio in the above-mentioned embodiment 2 has a resistivity of 0.028260Ω·mm 2 / m, tensile strength 155Mpa, elongation 10%;

[0043] The aluminum alloy rod is drawn into a single conductor wire with the following properties: tensile strength 125Mpa, elongation 14%, repeated bending times 30 times, yield strength 116N / mm 2 .

[0044] It is worth noting that in this embodiment, a special-shaped aluminum alloy single wire is drawn from an aluminum alloy rod, and then a special-shaped aluminum alloy single-twisted synthetic cable is made of an aluminum alloy core 10 conductor. With this process structure, the outer diameter of the conductor is smaller than that of the existing round aluminum alloy single-wire conductor, which reduces the diameter of the finished cable, increases the bending radius of the cable, and facilitates the installation and laying of the cable.

[0045] It should be noted that reducing the outer diameter of the conductor is more conducive to reducing the production cost of the cable, because the conductor has a small outer diameter and a small circumference, which reduces the weight of the materials used in the subsequent process to cover the previous process, such as the chemical cross-linking material used in the insulation layer 22, the soft fine copper wire layer 32 and the soft copper tape 31 used in the composite shielding structure 30, the interlocking armor layer 40 used in the armoring process, and the aluminum-plastic adhesive waterproof layer 50 and the flame-retardant and wear-resistant outer sheath layer 60 used for subsequent water blocking. The reduction in material usage not only reduces the cost of the cable, but also saves social resources, while achieving both economic and social benefits.

[0046] Example 3

[0047] The difference from the above-mentioned embodiment 2 is that, in this embodiment, the chemical composition mass ratio of the aluminum alloy core is: iron 0.55%, boron 0.06%, silicon 0.10%, copper 0.10%, magnesium 0.01%, zinc 0.03%, aluminum 99.11%, cerium 0.025%, and lanthanum 0.015%.

[0048] The aluminum alloy rod material prepared based on the chemical composition mass ratio in the above-mentioned embodiment 3 has a resistivity of 0.029160Ω·mm 2 / m, tensile strength 135Mpa, elongation 5%;

[0049] The aluminum alloy rod is drawn into a single conductor wire with the following properties: tensile strength 110Mpa, elongation 11%, repeated bending times 26 times, yield strength 102N / mm 2 .

[0050] Example 4

[0051] The difference from the above-mentioned embodiment 1 is that, in this embodiment, the chemical composition mass ratio of the aluminum alloy core is: iron 0.50%, boron 0.04%, silicon 0.10%, copper 0.15%, magnesium 0.01%, zinc 0.05%, aluminum 99.11%, cerium 0.025%, and lanthanum 0.015%.

[0052] The aluminum alloy rod material prepared based on the chemical composition mass ratio in the above-mentioned embodiment 4 has a resistivity of 0.029510Ω·mm 2 / m, tensile strength 125Mpa, elongation 3%;

[0053] The aluminum alloy rod is drawn into a single conductor wire with the following properties: tensile strength 105Mpa, elongation 8%, repeated bending times 20 times, yield strength 88N / mm 2 .

[0054] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A radial water-blocking high-voltage cable for photovoltaic power generation, characterized in that: It includes a cable core, an isolation layer, an interlocking armor layer, an aluminum-plastic bonding waterproof layer and an outer sheath layer arranged from the inside to the outside; The cable core includes an aluminum alloy core, a conductor shielding layer, an insulating layer, an insulating shielding layer, and a composite shielding structure from the inside to the outside. The conductor shielding layer, the insulating layer, and the insulating shielding layer are coated on the outside of the aluminum alloy core conductor by a three-layer co-extrusion process. The isolation layer is a hydrophobic polyethylene layer radially coated on the outside of the cable core, and water-blocking yarn is filled between the cable core and the isolation layer.

2. The radial water-blocking high-voltage cable for photovoltaic power generation according to claim 1, characterized in that: The aluminum-plastic bonding waterproof layer is formed by bonding a longitudinally wrapped double-sided plastic-coated aluminum tape and a polyethylene outer sheath, wherein the nominal thickness of the double-sided plastic-coated aluminum tape is at least 0.20 mm, and the nominal thickness of the bare aluminum tape is not less than 0.15 mm; The double-sided plastic-coated aluminum tape is completely and longitudinally wrapped outside the cable core, the longitudinal overlapping width is not less than 6mm, and the longitudinal overlapping width is not less than 20% of the circumference of the longitudinally wrapped wire core.

3. The radial water-blocking high-voltage cable for photovoltaic power generation according to claim 1, characterized in that: The cable core is formed by twisting three cable cores.

4. The radial water-blocking high-voltage cable for photovoltaic power generation according to claim 1, characterized in that: The composite shielding structure is a double-layer composite structure of soft fine copper wire layer and soft copper tape; Among them, the soft fine copper wire layer is made of 0.51mm soft fine copper wire and is evenly wound around the insulating shielding layer of the cable core, and the soft copper tape is overlapped and spirally wrapped outside the soft fine copper wire layer; the number of the soft fine copper wires is determined according to the shielding cross-sectional area, and the shielding cross-sectional area is determined according to the cable fault current.

5. An aluminum alloy core for photovoltaic power generation, applied to the radial water-blocking high-voltage cable for photovoltaic power generation according to claim 1, characterized in that: The chemical composition mass ratio of the aluminum alloy core is as follows: Iron 0.50-0.60%, boron 0.04-0.06%, silicon 0.10%, copper 0.10-0.15%, magnesium 0.01%, zinc 0.01-0.05%, cerium 0.020-0.025%, lanthanum 0.010-0.015%, and the balance is aluminum and inevitable impurities.

6. The aluminum alloy core for photovoltaic power generation according to claim 5, characterized in that: The mass percentage of aluminum in the chemical composition of the aluminum alloy core is 99.06-99.11%.

7. The aluminum alloy core for photovoltaic power generation according to claim 6, characterized in that: The aluminum alloy core has the following chemical composition ratios by mass: 0.60% iron, 0.04% boron, 0.10% silicon, 0.15% copper, 0.01% magnesium, 0.01% zinc, 99.06% aluminum, 0.020% cerium, and 0.010% lanthanum.

8. The aluminum alloy core for photovoltaic power generation according to claim 6, characterized in that: The aluminum alloy core is firstly melted and rolled into an aluminum alloy rod through aluminum ingot, and then the aluminum alloy rod is drawn into a special-shaped aluminum alloy single wire, and finally the special-shaped aluminum alloy single wire is twisted into a cable core.

9. The aluminum alloy core for photovoltaic power generation according to claim 8, characterized in that: The special-shaped aluminum alloy single wire is twisted into a circular structure through multiple strands of tight compression, and each layer is twisted in the forward and reverse directions.

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