Novel environment-friendly aluminum alloy core waterproof power cable for railway system and manufacturing method thereof

Abstract

The invention relates to the technical field of wires and cables, in particular to a novel environment-friendly aluminum alloy core waterproof power cable for a railway system and a manufacturing method thereof. Comprising special-shaped structure aluminum alloy conductors for electric conduction, an insulating layer, a water-blocking filler, a water-blocking wrapping tape, a water-blocking lining layer, a metal water-blocking layer, a water-blocking isolation sleeve, a galvanized steel wire armor, an external water-blocking tape, a water-blocking sheath and an internal water-blocking tape. The inner water-blocking tape is arranged on the outer side of the aluminum alloy conductor of the special-shaped structure, the insulating layer is arranged on the outer side of the inner water-blocking tape, the water-blocking filler and the water-blocking wrapping tape are arranged on the outer side of the insulating layer, the water-blocking lining layer is arranged on the outer side of the water-blocking wrapping tape, and the metal water-blocking layer is arranged on the outer side of the water-blocking lining layer. Compared with a cable adopting a traditional structure, the cable is smaller in outer diameter, lower in cost than a traditional copper core product, and capable of preventing the problems that insulation resistance is reduced due to poor water permeability during operation, operation faults of a railway electrical system are caused by breakdown of an insulating layer, and traffic transportation is affected.

Description

Technical Field

[0001] The invention relates to the technical field of electric wires and cables, in particular to a novel environmentally friendly aluminum alloy core waterproof power cable for a railway system and a manufacturing method thereof. Background Art

[0002] Aluminum alloy core waterproof power cable for railway system is a cable designed for railway system. It uses aluminum alloy material as conductor to replace traditional copper conductor, thus reducing cost and improving mechanical properties of cable. The traditional railway system power cable process structure usually adopts copper conductor twisting, extruded cross-linked polyethylene insulation, extruded polyvinyl chloride isolation sleeve after cabling, double-layer galvanized steel belt for armor layer, polyvinyl chloride material for sheath, and finally finished product inspection. The cable with this structure is expensive, and tested by the American ASTM E96 standard, the water permeability of polyvinyl chloride material is as high as 47.6, the water permeability of polyethylene material is 9.1, the water permeability of cross-linked polyethylene is 6.2, and the water permeability of metal materials such as aluminum and lead is 0. The test results show that polyvinyl chloride material cannot meet the insulation and sheath requirements of cables with long-term wading needs. The insulation resistance of such cable products will decrease due to poor water permeability during operation, and eventually the railway electrical system will fail due to the breakdown of the insulation layer, affecting transportation and causing great losses. Therefore, in view of the above problems, a new environmentally friendly aluminum alloy core railway system waterproof power cable and a manufacturing method thereof are proposed. Summary of the invention

[0003] The purpose of the present invention is to provide a novel environmentally friendly aluminum alloy core waterproof power cable for railway system and a manufacturing method thereof, so as to solve the problem that the conventional railway system power cable process structure usually adopts copper conductor twisting, extruded cross-linked polyethylene insulation, extruded polyvinyl chloride isolation sleeve after cabling, double-layer galvanized steel belt for armor layer, polyvinyl chloride material for sheath, and finally finished product inspection. The cable with this structure has high cost, and according to the test of American ASTM E96 standard, the water permeability of polyvinyl chloride material is as high as 47.6, the water permeability of polyethylene material is 9.1, the water permeability of cross-linked polyethylene is 6.2, and the water permeability of metal materials such as aluminum and lead is 0. The test results show that polyvinyl chloride material cannot meet the insulation and sheath requirements of cables with long-term wading requirements. During the operation of such cable products, the insulation resistance will decrease due to poor water permeability, and finally the railway electrical system will fail due to the breakdown of the insulation layer, which will affect transportation and cause great losses.

[0004] To achieve the above object, the present invention provides the following technical solutions: A novel environmentally friendly aluminum alloy core waterproof power cable for railway system and a manufacturing method thereof, comprising a special-shaped aluminum alloy conductor for conducting electricity, an insulating layer, a water-blocking filling, a water-blocking tape, a water-blocking lining layer, a metal water-blocking layer, a water-blocking isolation sleeve, a galvanized steel wire armor, an external water-blocking tape, a water-blocking sheath and an internal water-blocking tape; the external side of the special-shaped aluminum alloy conductor is provided with an internal water-blocking tape, the external side of the internal water-blocking tape is provided with an insulating layer, the external side of the insulating layer is provided with a water-blocking filling and a water-blocking tape, the external side of the water-blocking tape is provided with a water-blocking lining layer, the external side of the water-blocking lining layer is provided with a metal water-blocking layer, the external side of the metal water-blocking layer is wound with a water-blocking isolation sleeve, the external side of the water-blocking isolation sleeve is provided with a galvanized steel wire armor, the external side of the galvanized steel wire armor is provided with an external water-blocking tape, and the external side of the external water-blocking tape is provided with a water-blocking sheath; the vertical section of the special-shaped aluminum alloy conductor is fan-shaped, and the special-shaped aluminum alloy conductor is formed by twisting a plurality of aluminum alloy conductive wires with fan-shaped vertical sections.

[0005] As a further optimization of the present invention, the insulating layer is cross-linked polyethylene, and the cross-linked polyethylene is cross-linked by high-energy electron accelerator radiation to transform the original molecular structure from a linear structure to a network structure.

[0006] As a further optimized content of the present invention, wherein: the water-blocking filling is a water-blocking yarn, and the water-blocking filling is evenly distributed on the outside of the insulating layer and the inside of the water-blocking tape.

[0007] As a further optimized content of the present invention, the metal water-blocking layer is a composite material of aluminum strip and plastic composite strip, the metal water-blocking layer is longitudinally wrapped around the outer surface of the water-blocking lining layer, and the overlapping width of the metal water-blocking layer at the wrapping point is 15% of the width of the metal water-blocking layer.

[0008] As a further optimized content of the present invention, wherein: the metal water-blocking layer is tightly attached to the outer surface of the water-blocking lining layer through high-temperature baking, and the overlapping parts of the metal water-blocking layer are tightly attached.

[0009] As a further optimization of the present invention, the wrapping direction of the galvanized steel wire armor is left-handed, and the total gap between the galvanized steel wire wrapping inside the galvanized steel wire armor is less than the wire diameter of one steel wire.

[0010] As a further optimized content of the present invention, the water-blocking lining layer, the water-blocking isolation sleeve and the water-blocking protective sleeve are made of high-density polyethylene.

[0011] As a further optimized content of the present invention, the following steps are included: Step 1: Prepare a special-shaped aluminum alloy conductor. Use a specially designed wire drawing die to change the traditional round monofilament into a fan-shaped monofilament, and then twist multiple fan-shaped monofilaments to increase the filling factor of the conductor after twisting and reduce the gap area between the conductor monofilaments. Step 2: Use high-energy electron accelerator to irradiate cross-linked polyethylene, so that the molecular structure of polyethylene changes from linear to mesh structure, supports the insulation layer, and covers the outside of the internal water-blocking tape; The prepared multiple special-shaped aluminum alloy conductors are independently coated by internal water-blocking tapes; Water-blocking yarn and multi-layer water-blocking tape are used as the water-blocking filling and water-blocking wrapping tape of the cable, which are covered on the outside of the insulation layer; Step 3: coating the outer surface of the water-blocking tape with a water-blocking lining layer, and coating the outer surface of the water-blocking lining layer with a metal water-blocking layer; Step 4: Wrap the metal water-blocking layer formed by the aluminum tape and the plastic composite tape longitudinally on the surface of the water-blocking lining layer in a spiral wrapping manner, with the overlap rate of the spiral wrapping being not less than 15%, and then bake at a high temperature to make the overlap closely fit; Then the water-blocking isolation sleeve is coated on the outer surface of the metal water-blocking layer; Step 5: Use galvanized steel wire as the armor layer of the cable to form a galvanized steel wire armor; Step 6: The outer surface of the galvanized steel wire armor is covered with an external water-blocking tape and a water-blocking sheath in sequence to form a new environmentally friendly aluminum alloy core waterproof power cable for railway systems; Step 7: Conduct finished product inspection to ensure that the cable meets the performance requirements of railway system power cables.

[0012] Compared with the prior art, the present invention has the following beneficial effects: 1. The product of the present invention is light in weight and low in cost. It has a smaller outer diameter than cables with traditional structures and a lower cost than traditional copper core products. In addition, it can prevent the insulation resistance from decreasing due to poor water permeability, which may cause the railway electrical system to fail due to insulation layer breakdown and affect transportation. 2. In the present invention, the cable has a good rodent-proof effect, which can avoid the impact of power outages caused by rodent infestation and the cost pressure caused by frequent cable replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the water-blocking isolation sleeve of the present invention.

[0014] In the figure: 1. Special-shaped aluminum alloy conductor; 2. Insulation layer; 3. Water-blocking filling; 4. Water-blocking tape; 5. Water-blocking lining layer; 6. Metal water-blocking layer; 7. Water-blocking isolation sleeve; 8. Galvanized steel wire armor; 9. External water-blocking tape; 10. Water-blocking sheath; 11. Internal water-blocking tape. DETAILED DESCRIPTION

[0015] See also Figure 1-2 , the present invention provides a technical solution: A novel environmentally friendly aluminum alloy core waterproof power cable for railway system and a manufacturing method thereof, comprising a special-shaped aluminum alloy conductor 1 for conducting electricity, an insulating layer 2, a water-blocking filling 3, a water-blocking tape 4, a water-blocking inner lining 5, a metal water-blocking layer 6, a water-blocking isolation sleeve 7, a galvanized steel wire armor 8, an external water-blocking tape 9, a water-blocking sheath 10 and an internal water-blocking tape 11; an internal water-blocking tape 11 is arranged on the outer side of the special-shaped aluminum alloy conductor 1, an insulating layer 2 is arranged on the outer side of the internal water-blocking tape 11, a water-blocking filling 3 and a water-blocking tape 4 are arranged on the outer side of the insulating layer 2, a water-blocking inner lining 5 is arranged on the outer side of the water-blocking tape 4, a metal water-blocking layer 6 is arranged on the outer side of the water-blocking inner lining 5, and a metal water-blocking layer 6 is arranged on the outer side of the metal water-blocking layer 6 It is wound with a water-blocking isolation sleeve 7, a galvanized steel wire armor 8 is arranged on the outside of the water-blocking isolation sleeve 7, an external water-blocking tape 9 is arranged on the outside of the galvanized steel wire armor 8, and a water-blocking sheath 10 is arranged on the outside of the external water-blocking tape 9; the vertical section of the special-shaped aluminum alloy conductor 1 is fan-shaped, and the special-shaped aluminum alloy conductor 1 is twisted with multiple aluminum alloy conductive wires with fan-shaped vertical sections. Under the premise of ensuring that the cable meets the current carrying capacity required by the design, a specially designed wire drawing die is used to change the traditional conductor structure from a round monofilament to a fan-shaped monofilament to improve the filling coefficient of the conductor after twisting. After the process is improved, the gap area between the conductor monofilaments is reduced, and the conductor diameter and actual cross-sectional area after twisting are smaller than those of traditional products. Cable products using this structure can save 40-60% of the cost compared to traditional copper core cables. It can not only ensure that the cable has good electrical properties, mechanical and physical properties and environmental performance, but also play a cost reduction effect.

[0016] As a technical solution for further implementation of this solution, the insulating layer 2 is cross-linked polyethylene, and the cross-linked polyethylene is cross-linked by high-energy electron accelerator radiation to transform the original molecular structure from linear to mesh structure. After the polyethylene is cross-linked by high-energy electron accelerator radiation, the original molecular structure is transformed from linear to mesh structure, and the molecular gap is smaller, which improves the electrical insulation performance while also greatly improving the waterproof performance of the cable; As a technical solution further implemented in this solution, the water-blocking filling 3 is a water-blocking yarn, and the water-blocking filling 3 is evenly distributed on the outside of the insulating layer 2 and the inside of the water-blocking tape 4, which can effectively prevent water or moisture from penetrating into the cable through the cable end or the sheath surface, thereby playing a waterproof role; As a technical solution for further implementation of this solution, the metal water-blocking layer 6 is a composite material of an aluminum strip and a plastic composite strip. The metal water-blocking layer 6 is longitudinally wrapped on the outer surface of the water-blocking lining layer 5. The overlap width of the metal water-blocking layer 6 is 15% of the width of the metal water-blocking layer 6. The metal water-blocking layer 6 is tightly attached to the outer surface of the water-blocking lining layer 5 by high-temperature baking. The overlap of the metal water-blocking layer 6 is tightly fitted, which can not only ensure the original performance of the cable, but also play a waterproof role and ensure that the cable has good bending performance. As a technical solution for further implementation of this solution, the galvanized steel wire armor 8 is wrapped in the left direction, and the total gap of the galvanized steel wire wrapped inside the galvanized steel wire armor 8 is less than the wire diameter of one steel wire. The use of galvanized steel wire as the armor layer of the cable can fully ensure that the cable can withstand high-intensity external force impact, and protect the cable from damage to the cable insulation caused by accidental impact during construction or operation, affecting the power supply safety. The use of steel wire armor can also effectively improve the bending performance of the cable and play a good anti-rat function. As a technical solution for further implementation of this scheme, the water-blocking lining layer 5, the water-blocking isolation sleeve 7 and the water-blocking sheath 10 are made of high-density polyethylene. The molecular spacing of high-density polyethylene is small, and the water-blocking performance is better than other polymer materials. It can ensure the radial waterproof performance of the cable and ensure the normal operation of the power supply system.

[0017] As a technical solution for further implementing this plan, the following steps are included: Step 1: Prepare a special-shaped aluminum alloy conductor 1, change the traditional round monofilament into a fan-shaped monofilament through a specially designed wire drawing die, and then twist a plurality of fan-shaped monofilaments to increase the filling factor of the conductor after twisting and reduce the gap area between the conductor monofilaments; Step 2: Use a high-energy electron accelerator to irradiate cross-linked polyethylene, so that the molecular structure of the polyethylene changes from a linear structure to a mesh structure, supporting the insulating layer 2 and covering the outside of the internal water-blocking tape 11; The prepared plurality of special-shaped aluminum alloy conductors 1 are independently coated by an internal water-blocking tape 11; Water-blocking yarn and multi-layer water-blocking tape are selected as the water-blocking filling 3 and water-blocking wrapping tape 4 of the cable, which are coated on the outside of the insulating layer 2; Step 3: Covering the outer surface of the water-blocking tape 4 with the water-blocking lining layer 5, and covering the outer surface of the water-blocking lining layer 5 with the metal water-blocking layer 6; Step 4: Wrap the metal water-blocking layer 6 formed by the aluminum tape and the plastic composite tape longitudinally on the surface of the water-blocking lining layer 5 in a spiral wrapping manner, with the overlap rate of the spiral wrapping being not less than 15%, and then bake at a high temperature to make the overlapped parts closely fit; Then the water-blocking isolation sleeve 7 is coated on the outer surface of the metal water-blocking layer 6; Step 5: Using galvanized steel wire as the armor layer of the cable to form a galvanized steel wire armor 8; Step 6: The outer surface of the galvanized steel wire armor 8 is covered with an external water-blocking tape 9 and a water-blocking sheath 10 in sequence to make a new environmentally friendly aluminum alloy core waterproof power cable for railway systems; Step 7: Conduct finished product inspection to ensure that the cable meets the performance requirements of railway system power cables This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. New environmentally friendly aluminum alloy core waterproof power cable for railway system, characterized by: It comprises a special-shaped aluminum alloy conductor (1) for conducting electricity, an insulating layer (2), a water-blocking filling (3), a water-blocking tape (4), a water-blocking lining layer (5), a metal water-blocking layer (6), a water-blocking isolation sleeve (7), a galvanized steel wire armor (8), an external water-blocking tape (9), a water-blocking sheath (10), and an internal water-blocking tape (11); The outer side of the special-shaped aluminum alloy conductor (1) is provided with an internal water-blocking tape (11), the outer side of the internal water-blocking tape (11) is provided with an insulating layer (2), the outer side of the insulating layer (2) is provided with a water-blocking filler (3) and a water-blocking tape (4), the outer side of the water-blocking tape (4) is provided with a water-blocking inner lining layer (5), the outer side of the water-blocking inner lining layer (5) is provided with a metal water-blocking layer (6), the outer side of the metal water-blocking layer (6) is wrapped with a water-blocking isolation sleeve (7), the outer side of the water-blocking isolation sleeve (7) is provided with a galvanized steel wire armor (8), the outer side of the galvanized steel wire armor (8) is provided with an external water-blocking tape (9), and the outer side of the external water-blocking tape (9) is provided with a water-blocking sheath (10); The special-shaped aluminum alloy conductor (1) has a vertical cross-section that is fan-shaped, and the special-shaped aluminum alloy conductor (1) is formed by twisting a plurality of aluminum alloy conductive wires that have vertical cross-sections that are fan-shaped.

2. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The insulating layer (2) is cross-linked polyethylene, and the cross-linked polyethylene is cross-linked by high-energy electron accelerator radiation so that the original molecular structure is transformed from a linear structure to a network structure.

3. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The water-blocking filling (3) is a water-blocking yarn, and the water-blocking filling (3) is evenly distributed on the outside of the insulating layer (2) and on the inside of the water-blocking tape (4).

4. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The metal water-blocking layer (6) is a composite material of an aluminum strip and a plastic composite strip. The metal water-blocking layer (6) is longitudinally wrapped around the outer surface of the water-blocking lining layer (5). The overlap width of the metal water-blocking layer (6) at the wrapping portion is 15% of the width of the metal water-blocking layer (6).

5. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The metal water-blocking layer (6) is tightly attached to the outer surface of the water-blocking lining layer (5) by high-temperature baking, and the overlapping parts of the metal water-blocking layer (6) are tightly attached.

6. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The wrapping direction of the galvanized steel wire armor (8) is left-handed, and the total gap between the wrappings of the galvanized steel wires inside the galvanized steel wire armor (8) is less than the wire diameter of one steel wire.

7. The new environmentally friendly aluminum alloy core waterproof power cable for railway system according to claim 1 is characterized by: The water-blocking lining layer (5), the water-blocking isolation sleeve (7) and the water-blocking protective sleeve (10) are made of high-density polyethylene.

8. A method for manufacturing a novel environmentally friendly aluminum alloy core waterproof power cable for railway systems according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: preparing a special-shaped aluminum alloy conductor (1), converting a traditional round monofilament into a fan-shaped monofilament through a specially designed wire drawing die, and then twisting a plurality of fan-shaped monofilaments to increase the filling factor of the conductor after twisting and reduce the gap area between the conductor monofilaments; Step 2: Use a high-energy electron accelerator to irradiate cross-linked polyethylene, so that the molecular structure of the polyethylene changes from a linear structure to a mesh structure, supporting the insulating layer (2) and covering the outside of the internal water-blocking tape (11); Independently coating the prepared plurality of special-shaped aluminum alloy conductors (1) with an internal water-blocking tape (11); Water-blocking yarn and multi-layer water-blocking tape are selected as the water-blocking filling (3) and water-blocking wrapping tape (4) of the cable, and are wrapped around the outside of the insulation layer (2); Step three: coating the outer surface of the water-blocking tape (4) with a water-blocking inner lining layer (5), and coating the outer surface of the water-blocking inner lining layer (5) with a metal water-blocking layer (6); Step 4: Wrap the metal water-blocking layer (6) formed by the aluminum tape and the plastic composite tape longitudinally on the surface of the water-blocking lining layer (5) in a spiral wrapping manner, with the overlap rate of the spiral wrapping being not less than 15%, and then bake at a high temperature to make the overlapped parts closely fit; Then, the water-blocking isolation sleeve (7) is covered on the outer surface of the metal water-blocking layer (6); Step 5: Using galvanized steel wire as the armor layer of the cable to form a galvanized steel wire armor (8); Step 6: The outer surface of the galvanized steel wire armor (8) is covered with an external water-blocking tape (9) and a water-blocking sheath (10) in sequence to produce a new environmentally friendly aluminum alloy core waterproof power cable for railway systems; Step 7: Conduct finished product inspection to ensure that the cable meets the performance requirements of railway system power cables.

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