110 kv polypropylene insulated polyethylene sheathed longitudinal water blocking and flame retardant class a power cable

Abstract

The utility model relates to power cable technical field, more particularly to 110kV polypropylene insulation polyethylene sheath longitudinal water resistance and flame retardant A type power cable, include: conductor, the conductor includes multilayer twisted conductor, insulating layer, extruding in the outer wall of conductor, semiconductive water resistance wrapping layer, the outer wall of insulating layer is covered, wrinkle aluminium jacket layer, the outer wall of semiconductive water resistance wrapping layer is covered, the utility model discloses polypropylene insulation power cable adopts multilayer twisted conductor, and the inner layer is circular twisted conductor, and the outer layer adopts fan -shaped strand block twisted conductor, and sets up layered water -resisting belt structure, and through independent layered water -resisting structure can promote water -resisting performance, guarantees the stability of twisted simultaneously, and high filling rate, reduces the power loss caused by skin effect, sets up semiconductive water resistance wrapping layer between wrinkle aluminium jacket layer and insulating layer, makes the cable satisfy the demand of water resistance and flame retardant.

Description

Technical Field

[0001] This utility model relates to the field of power cable technology, specifically to a 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable. Background Technology

[0002] Traditional 110kV power cables mostly use cross-linked polyethylene (XLPE) as insulation material. Although this material has stable electrical properties, the cross-linking process is energy-intensive, inefficient, and has a long production cycle (requiring degassing). Furthermore, various additives in XLPE precipitate out during cross-linking vulcanization, forming cross-linking byproducts. Some of these byproducts are directly released into the air with nitrogen gas. Currently, the collected cross-linking byproducts can only be incinerated or buried, causing serious pollution to the environment and groundwater. In addition, as a typical thermosetting material, XLPE has high recycling costs and extremely low utilization rates.

[0003] Polypropylene (PP) has excellent electrical properties, including high electrical strength and volume resistivity. As a thermoplastic material, it does not require cross-linking and degassing during cable production. Compared with XLPE, it has lower energy consumption, shorter production cycle, and can significantly reduce carbon emissions, showing great potential in environmental protection. Therefore, there is a potential market demand for 110kV polypropylene insulated power cables, and there is an urgent need for a polypropylene insulated power cable with comprehensive water-blocking and flame-retardant properties. Summary of the Invention

[0004] To address the technical problems existing in current power cables, this utility model proposes a 110kV polypropylene insulated, polyethylene sheathed, longitudinally water-blocking and flame-retardant Class A power cable, comprising:

[0005] Conductor, said conductor comprising multilayer stranded conductor;

[0006] An insulating layer is extruded onto the outer wall of the conductor;

[0007] A semiconducting resistive water-wound cladding is wrapped around the outer wall of the insulating layer;

[0008] A wrinkled aluminum sheath covers the outer wall of the semiconducting resistive water-wound sheath.

[0009] A polyethylene sheath layer is extruded onto the outer wall of the corrugated aluminum sheath layer;

[0010] The multilayer stranded conductor includes a circular conductor stranded structure and a fan-shaped strand stranded structure. Semiconductor resistive water wrapping tape is wrapped between every two layers of circular conductor stranded structure. Water-blocking structure is filled between each fan-shaped strand. Semiconductor resistive water wrapping tape is wrapped around the outside of each fan-shaped strand stranded structure.

[0011] The circular conductor stranded structure includes a first stranded structure and a second stranded structure. The outer wall of the first stranded structure is wrapped with a first semiconducting resistive water wrapping layer, and the outer wall of the second stranded structure is wrapped with a second semiconducting resistive water wrapping layer.

[0012] Preferably, both the first and second semiconducting resistive water-blocking tape wrapping layers are single-sided water-blocking tapes, with the water-blocking side facing the outside of the cable.

[0013] Preferably, the fan-shaped strand twisted structure includes a third layer twisted structure and a fourth layer twisted structure. Both the third layer twisted structure and the fourth layer twisted structure include multiple fan-shaped strands. Adjacent fan-shaped strands are filled with double-sided water-blocking tape. The outer layer of the third layer twisted structure and the fourth layer twisted structure is provided with a third semi-conductive water-blocking tape wrapping layer.

[0014] Preferably, the insulating layer comprises a three-layer co-extruded inner shielding layer, a polypropylene insulating layer, and an outer shielding layer. The thickness of the inner shielding layer is 1.2 mm, with a minimum thickness of 0.8 mm, and the thickness of the outer shielding layer is 1.0 mm, with a minimum thickness of 0.7 mm.

[0015] Preferably, the semiconducting resistive water wrapping layer includes a semiconducting resistive water tape wrapping structure, the wrapping overlap rate of the semiconducting resistive water tape is 45~50%, and the number of wrapping layers is two.

[0016] Preferably, a mica and silicone rubber composite tape wrapping layer is provided between the inner semiconducting resistive water tape wrapping structure and the outer semiconducting resistive water tape wrapping structure.

[0017] Preferably, the wrinkled aluminum sheath includes a longitudinally wrapped structure of wrinkled aluminum strips, the surface of the wrinkled aluminum strips is coated with an epoxy zinc-rich primer layer and a polyurethane topcoat layer, and the surface of the wrinkled aluminum sheath is coated with an asphalt coating.

[0018] Preferably, the polyethylene sheath layer comprises a Class A flame-retardant polyethylene sheath layer. Particularly preferred is that the surface of the flame-retardant polyethylene sheath layer is provided with a graphite coating, which fills the micropores on the surface of the polyethylene sheath and prevents moisture from penetrating longitudinally.

[0019] Compared with existing technologies, the significant advantages of the 110kV polypropylene insulated, polyethylene sheathed, longitudinally water-blocking and flame-retardant Class A power cable proposed in this utility model are as follows:

[0020] This utility model proposes a 110kV polypropylene insulated, polyethylene sheathed, longitudinally water-blocking and flame-retardant Class A power cable. It employs multi-layer stranded conductors, with an inner layer of circular stranded conductors and an outer layer of fan-shaped stranded conductors. A layered water-blocking tape structure is incorporated, which enhances water-blocking performance while ensuring stranding stability and high filler ratio, reducing power loss caused by the skin effect. A semi-conductive water-resistant wrapping layer is placed between the corrugated aluminum sheath and the insulation layer. This provides elastic filling and longitudinal water blocking, while also improving the cable's flame-retardant performance, thus meeting both water-blocking and flame-retardant requirements. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of a 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable as shown in this utility model.

[0022] Figure 2 This is a schematic diagram of the cross-sectional structure of a 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable as shown in this utility model. Detailed Implementation

[0023] To better understand the technical content of this utility model, specific embodiments are provided below in conjunction with the accompanying drawings.

[0024] Combination Figure 1 and Figure 2 As shown, the 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable of this utility model embodiment includes a conductor 10, an insulation layer 20, a semi-conductive water-blocking wrapping layer 30, a corrugated aluminum sheath layer 40, and a polyethylene sheath layer 50.

[0025] Combination Figure 1 and Figure 2 As shown, conductor 10 includes a multilayer stranded conductor. The multilayer stranded conductor includes a circular conductor stranded structure and a sector stranded structure. Semiconductor resistive water wrapping tape is wrapped between every two layers of circular conductor stranded structure. A water-blocking structure is filled between each sector strand. Semiconductor resistive water wrapping tape is wrapped around the outside of each layer of sector stranded structure.

[0026] By layering the conductors and setting layered water-blocking strips between each layer, the water-blocking performance can be improved through layered water blocking. In addition, the circular stranded conductors in the inner layer can ensure the stability of the stranding, and the fan-shaped conductors in the outer layer can improve the fill rate and reduce the power loss caused by the skin effect.

[0027] Furthermore, the circular conductor stranded structure includes a first stranded structure 11 and a second stranded structure 12. The outer wall of the first stranded structure 11 is wrapped with a first semiconducting resistive water wrapping layer 15, and the outer wall of the second stranded structure 12 is wrapped with a second semiconducting resistive water wrapping layer 16.

[0028] In an optional embodiment, both the first semiconducting resistive water tape wrapping layer 15 and the second semiconducting resistive water tape wrapping layer 16 are single-sided water-blocking tapes, with the water-blocking side facing the outside of the cable.

[0029] In this way, the water-blocking effect of each layer of water-blocking strip is independent. Even if one layer of water-blocking strip fails, the other water-blocking strips can still effectively block water penetration, avoiding the performance degradation of a single water-blocking strip due to long-term moisture absorption.

[0030] In an optional embodiment, the fan-shaped strand twisted structure includes a third layer twisted structure 13 and a fourth layer twisted structure 14. Both the third layer twisted structure 13 and the fourth layer twisted structure 14 include multiple fan-shaped strands. Adjacent fan-shaped strands are filled with double-sided water-blocking tape 17. The outer layer of the third layer twisted structure 13 and the fourth layer twisted structure 14 is provided with a third semi-conductive water-blocking tape wrapping layer 18.

[0031] Thus, by placing the double-sided water-blocking strip between the fan-shaped strands, the moisture between the strands can be absorbed, preventing water vapor from passing between the two layers of fan-shaped twisted structure. At the same time, it can buffer mechanical stress and prevent conductor deformation from damaging the water-blocking structure.

[0032] Furthermore, the insulating layer 20 is extruded onto the outer wall of the conductor 10.

[0033] Optionally, the insulation layer 20 includes a three-layer co-extruded inner shielding layer 21, a polypropylene insulation layer 22, and an outer shielding layer 23. The thickness of the inner shielding layer 21 is 1.2 mm, with a minimum thickness of 0.8 mm, and the thickness of the outer shielding layer is 1.0 mm, with a minimum thickness of 0.7 mm.

[0034] Among them, the polypropylene insulation layer 22 is a ceramicized polypropylene insulation layer. After polypropylene decomposes at high temperature, it can form a porous ceramic skeleton, which improves the flame retardancy of the cable.

[0035] Furthermore, a semiconducting resistive water wrapping layer 30 covers the outer wall of the insulating layer 20. The semiconducting resistive water wrapping layer 30 includes a semiconducting resistive water tape wrapping structure, with a wrapping overlap rate of 45-50% and two wrapping layers. A corrugated aluminum sheath layer 40 covers the outer wall of the semiconducting resistive water wrapping layer 30.

[0036] A semi-conductive resistive water wrapping layer 30 is provided between the corrugated aluminum sheath 40 and the insulating layer 20. This can average the electric field between the insulating layer 20 and the corrugated aluminum sheath 40. At the same time, the two layers of semi-conductive wrapping structure act as elastic fillers, which can reduce the pressure of the corrugated aluminum sheath 40 on the surface of the insulating layer 20, and also act as a water barrier between the corrugated aluminum sheath 40 and the insulating layer 20.

[0037] Furthermore, a composite wrapping structure of mica tape and silicone rubber tape is wrapped between the inner and outer semi-conductive resistive water tape wrapping layers. The mica tape and silicone rubber tape are bonded together before being wrapped to form the wrapping layer. The silicone rubber-mica composite tape improves the flame retardant performance of the cable. Furthermore, the corrugated aluminum sheath 40 provides longitudinal waterproofing and fire resistance, preventing open flames from penetrating the corrugated aluminum sheath 40 and affecting the internal structure of the cable.

[0038] Furthermore, the wrinkled aluminum sheath 40 includes a longitudinally wrapped structure of wrinkled aluminum strips, and the surface of the wrinkled aluminum strips is coated with an epoxy zinc-rich primer layer and a polyurethane topcoat layer.

[0039] Thus, by coating the surface of the corrugated aluminum strip with an epoxy zinc-rich primer layer, the zinc particles preferentially form micro-batteries with the aluminum substrate, and the oxidation corrosion of aluminum is delayed through the sacrificial anode mechanism, the life of the corrugated aluminum strip can be extended. The formation of a dense protective film on the surface of the aluminum strip by epoxy resin can improve the moisture resistance and further improve the corrosion resistance, which can meet the requirements for use in water vapor environments.

[0040] Furthermore, the surface of the corrugated aluminum sleeve 40 is coated with an asphalt coating. The asphalt coating can penetrate into the gaps of the corrugated aluminum sleeve 40, effectively preventing moisture from seeping in along the gaps.

[0041] Preferably, the polyethylene sheath layer 50 is extruded onto the outer wall of the corrugated aluminum sheath layer 40. The polyethylene sheath layer 50 includes a flame-retardant polyethylene sheath layer, and the surface of the flame-retardant polyethylene sheath layer is provided with a graphite coating. The flame-retardant polyethylene sheath layer is made of Class A flame-retardant polyethylene.

[0042] The graphite coating on the surface fills the micropores of the polyethylene sheath, preventing moisture from penetrating vertically and making it suitable for high humidity environments.

[0043] In conjunction with the above embodiments, the polypropylene insulated power cable proposed in this utility model adopts a multi-layer stranded conductor, with an inner layer of circular stranded conductor and an outer layer of fan-shaped stranded conductor. It also features a layered water-blocking tape structure. The independent layered water-blocking structure can improve water-blocking performance, while ensuring the stability of stranding and a high filler ratio, reducing power loss caused by the skin effect. A semi-conductive water-resistant wrapping layer is set between the corrugated aluminum sheath layer and the insulation layer, which not only serves as an elastic filler but also achieves longitudinal water-blocking effect. At the same time, it improves the flame-retardant performance of the cable, enabling the cable to meet the requirements of water blocking and flame retardancy.

[0044] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Those skilled in the art to which this invention pertains can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this invention shall be determined by the claims.

Claims

1. A 110kV polypropylene insulated, polyethylene sheathed, longitudinally water-blocking and flame-retardant Class A power cable, characterized in that, include: Conductor (10), said conductor (10) comprising a multilayer stranded conductor; An insulating layer (20) is extruded onto the outer wall of the conductor (10); A semiconducting resistive water-wound cladding (30) covers the outer wall of the insulating layer (20); A wrinkled aluminum sheath (40) covers the outer wall of the semiconducting resistive water-wound sheath (30); A polyethylene sheath layer (50) is extruded onto the outer wall of the corrugated aluminum sheath layer (40); The multilayer stranded conductor includes a circular conductor stranded structure and a fan-shaped strand stranded structure. Semiconductor resistive water wrapping tape is wrapped between every two layers of circular conductor stranded structure. Water-blocking structure is filled between each fan-shaped strand. Semiconductor resistive water wrapping tape is wrapped around the outside of each fan-shaped strand stranded structure. The circular conductor stranded structure includes a first stranded structure (11) and a second stranded structure (12). The outer wall of the first stranded structure (11) is wrapped with a first semiconducting resistive water tape wrapping layer (15), and the outer wall of the second stranded structure (12) is wrapped with a second semiconducting resistive water tape wrapping layer (16). Both the first semiconducting resistive water-blocking tape wrapping layer (15) and the second semiconducting resistive water-blocking tape wrapping layer (16) are single-sided water-blocking tapes with the water-blocking side facing the outside of the cable.

2. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 1, characterized in that, The fan-shaped strand twisted structure includes a third layer twisted structure (13) and a fourth layer twisted structure (14). Both the third layer twisted structure (13) and the fourth layer twisted structure (14) include multiple fan-shaped strands, and double-sided water-blocking strips (17) are filled between adjacent fan-shaped strands.

3. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 2, characterized in that, The outer layer of the third layer stranded structure (13) and the fourth layer stranded structure (14) is provided with a third semi-conductive resistive water tape wrapping layer (18).

4. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 1, characterized in that, The insulation layer (20) includes a three-layer co-extruded inner shielding layer (21), a polypropylene insulation layer (22), and an outer shielding layer (23). The thickness of the inner shielding layer (21) is 1.2 mm, with a minimum thickness of 0.8 mm. The thickness of the outer shielding layer is 1.0 mm, with a minimum thickness of 0.7 mm.

5. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 1, characterized in that, The semiconducting resistive water wrapping layer (30) includes a semiconducting resistive water tape wrapping structure, wherein the wrapping overlap rate of the semiconducting resistive water tape is 45~50%, and the number of wrapping layers is two.

6. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 5, characterized in that, A mica and silicone rubber composite tape wrapping layer is provided between the inner and outer semiconducting resistive water tape wrapping structures.

7. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 1, characterized in that, The wrinkled aluminum sheath (40) includes a longitudinally wrapped structure of wrinkled aluminum strips.

8. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 7, characterized in that, The surface of the wrinkled aluminum strip is coated with an epoxy zinc-rich primer layer and a polyurethane topcoat layer, and the surface of the wrinkled aluminum sleeve (40) is coated with an asphalt coating.

9. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 1, characterized in that, The polyethylene sheath layer (50) includes a Class A flame-retardant polyethylene sheath layer.

10. The 110kV polypropylene insulated polyethylene sheathed longitudinal water-blocking and flame-retardant Class A power cable according to claim 9, characterized in that, The surface of the flame-retardant polyethylene sheath layer is coated with a graphite coating that fills the micropores on the surface of the polyethylene sheath, preventing moisture from penetrating longitudinally.

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