Polypropylene insulated high-voltage cable with high-water-resistance structure

Abstract

The utility model discloses a polypropylene insulation high-voltage cable with a high water-blocking structure. The high-voltage cable comprises a conductor, a semi-conductive water-blocking shielding tape, a first semi-conductive polypropylene shielding layer, a polypropylene insulating layer, a second semi-conductive polypropylene shielding layer, a first semi-conductive water-blocking buffer tape, a copper wire shielding layer, a second semi-conductive water-blocking buffer tape, a metal sheath layer and a non-metal outer sheath layer. According to the utility model, the outer side of the semi-conductive water-blocking shielding tape is of a three-layer co-extrusion structure, the first semi-conductive polypropylene shielding layer and the second semi-conductive polypropylene shielding layer are made of ultra-smooth semi-conductive polypropylene materials, an electric field can be better homogenized, the polypropylene insulating layer is made of polypropylene insulating materials, the insulating performance is excellent, and the service life of the cable is prolonged. The polypropylene material is used as the insulating layer of the high-voltage cable, so that the following problems can be solved: crosslinking is not needed in the production process, energy is saved, the production speed of polypropylene insulation is far higher than that of crosslinked polyethylene insulation, a degassing process is not needed, and the production time is saved.

Description

Technical Field

[0001] The utility model relates to a high-voltage cable, in particular to a novel polypropylene insulated high-water-resistance structure high-voltage cable. Background Art

[0002] Power cables are used to transmit and distribute electric energy. They are commonly used in urban underground power grids, power station lead-out lines, internal power supply for industrial and mining enterprises, and underwater transmission lines across rivers and seas. The proportion of cables in power lines is gradually increasing. High-voltage power cables are cable products used to transmit and distribute high-power electric energy in the trunk lines of power systems, including power cables of various voltage levels from 66 to 500 kV and various insulations.

[0003] At present, most of the high-voltage power cables installed worldwide are cross-linked polyethylene insulated cables (commonly known as "cross-linked cables"), which are cables made by coating the metal conductor with a cross-linked polyethylene insulation layer. Cross-linked polyethylene is widely used in the insulation of high-voltage cables for its excellent electrical and mechanical properties.

[0004] In the actual production and manufacturing process of cables, cross-linked cables (also known as XLPE cables) use heating methods to transform the polyethylene molecules that constitute the main insulation layer of the cable from a linear molecular structure to a main network molecular structure, that is, the thermoplastic polyethylene is transformed into a thermosetting cross-linked polyethylene, thereby improving its heat resistance and mechanical properties, reducing its shrinkage, and preventing it from melting after being heated.

[0005] Although cross-linked polyethylene has many outstanding advantages as an insulating material, and some excellent products have been developed after years of efforts, cross-linked cables use cross-linked polyethylene insulation materials, and cross-linked polyethylene insulation materials have their own thermosetting characteristics, which leads to many defects in cross-linked cables: cross-linking is required during production, and high-temperature and high-pressure vulcanization pipelines are required, which consumes a lot of energy and will produce harmful gases and substances such as cross-linking by-products; the production speed is slow, and a degassing process is required after production is completed, which consumes a lot of energy and takes 7-12 days for degassing, which is a long time; the material cannot be recycled and reused after molding. Utility Model Content

[0006] In view of the many problems existing in the above-mentioned use of cross-linked polyethylene insulation, the utility model provides a polypropylene insulated high-voltage cable with a high water-resistance structure. The production process does not require cross-linking or high-temperature and high-pressure vulcanization pipelines, which saves energy, improves production efficiency, and is more environmentally friendly.

[0007] In order to achieve the above-mentioned purpose, the utility model provides a polypropylene insulated high-voltage cable with a high water-resistance structure, which comprises, from the inside to the outside, a conductor, a semiconductive water-resistance shielding tape, a first semiconductive polypropylene shielding layer, a polypropylene insulation layer, a second semiconductive polypropylene shielding layer, a first semiconductive water-resistance buffer tape, a copper wire shielding layer, a second semiconductive water-resistance buffer tape, a metal sheath layer and a non-metallic outer sheath layer, wherein the conductor is formed by twisting copper monofilaments, a water-resistance tape is longitudinally wrapped between each layer of conductor, and the first semiconductive polypropylene shielding layer, the polypropylene insulation layer and the second semiconductive polypropylene shielding layer are a three-layer co-extruded structure.

[0008] Preferably, the metal sheath layer comprises a lead sheath layer and an asphalt coating located outside the lead sheath layer.

[0009] Preferably, the metal sheath layer is a longitudinally wrapped aluminum-plastic composite tape.

[0010] Preferably, the non-metallic outer sheath layer is a polyethylene or polyvinyl chloride outer sheath layer.

[0011] Preferably, a semiconductive layer or a graphite coating is extruded on the outside of the non-metallic outer sheath layer.

[0012] Furthermore, an inner sheath layer, an aluminum wire armor layer and a third semiconducting water-resistant buffer zone are provided between the metal sheath layer and the non-metallic outer sheath layer.

[0013] Furthermore, the inner sheath layer is an MDPE (medium density polyethylene) inner sheath layer.

[0014] Through the above technical solution, the utility model achieves the following beneficial effects:

[0015] 1. In the utility model, the outer side of the semiconductive water-resistant shielding tape is a three-layer co-extrusion structure. The first semiconductive polypropylene shielding layer and the second semiconductive polypropylene shielding layer are both made of ultra-smooth semiconductive polypropylene materials, which can better homogenize the electric field. The polypropylene insulation layer uses polypropylene insulation materials with excellent insulation performance. Due to the material properties, the use of polypropylene materials as the insulation layer of high-voltage cables can solve the following problems: 1) No cross-linking is required during the production process, and no high-temperature and high-pressure vulcanization pipelines are required, which saves energy; 2) Since high-temperature and high-pressure cross-linking is not required, the production speed of polypropylene insulation is much higher than that of cross-linked polyethylene insulation; 3) Compared with polyethylene insulated high-voltage cables, polypropylene insulated high-voltage cables do not require a degassing process, so production time is saved; 4) Polypropylene materials can be recycled and reused, which is more environmentally friendly.

[0016] 2. In the utility model, the water-blocking tape is longitudinally wrapped between each layer of the conductor, which can effectively prevent water from flowing along the conductor to the inside of the cable; the multi-layer semiconductor water-blocking buffer tape can greatly improve the water-blocking performance of the cable; the metal sheath layer can provide a channel for the fault current, and at the same time, the metal sheath layer has excellent waterproof performance and provides radial water-blocking performance for the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural schematic diagram of an implementation of the polypropylene insulated high water resistance structure high voltage cable of the utility model;

[0018] Figure 2 It is a structural schematic diagram of another embodiment of the polypropylene insulated high water resistance structure high voltage cable of the utility model;

[0019] Figure 3 It is a structural schematic diagram of the third implementation mode of the polypropylene insulated high water resistance structure high voltage cable described in the utility model.

[0020] Description of Reference Numerals

[0021] 1 conductor, 2 semiconductive water-resistant shielding tape, 3 first semiconductive polypropylene shielding layer, 4 polypropylene insulation layer, 5 second semiconductive polypropylene shielding layer, 6 first semiconductive water-resistant buffer tape, 7 copper wire shielding layer, 8 second semiconductive water-resistant buffer tape, 9 metal sheath layer, 10 non-metallic outer sheath layer, 11 inner sheath layer, 12 aluminum wire armor layer, 13 third semiconductive water-resistant buffer tape. DETAILED DESCRIPTION

[0022] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0023] First of all, it should be noted that in the following description, some directional words involved in order to clearly illustrate the technical solution of the utility model, such as "outer", "inner", etc., all have meanings by analogy with the normal directions of components in the cable. For example, the position pointing to the conductor is the inner part, and the position opposite to it is the outer part. This is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it cannot be understood as a limitation on the utility model.

[0024] In addition, the terms "first", "second" and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more of the said features.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Example 1

[0027] like Figure 1-Figure 2 As shown, the polypropylene insulated high water-resistance structure high-voltage cable of the utility model includes, from inside to outside, a conductor 1, a semiconductive water-resistant shielding tape 2, a first semiconductive polypropylene shielding layer 3, a polypropylene insulation layer 4, a second semiconductive polypropylene shielding layer 5, a first semiconductive water-resistant buffer tape 6, a copper wire shielding layer 7, a second semiconductive water-resistant buffer tape 8, a metal sheath layer 9 and a non-metallic outer sheath layer 10. The conductor 1 is formed by twisting copper monofilaments, and a water-resistant tape is longitudinally wrapped between each layer of conductors. The first semiconductive polypropylene shielding layer 3, the polypropylene insulation layer 4, and the second semiconductive polypropylene shielding layer 5 are a three-layer co-extruded structure.

[0028] The utility model uses polypropylene insulation material. Due to the material characteristics, using polypropylene material as the insulation layer of the high-voltage cable can solve the following problems:

[0029] 1) No cross-linking is required during the production process, and no high-temperature and high-pressure vulcanization pipeline is required, which saves energy;

[0030] 2) Since high temperature and high pressure cross-linking is not required, the production speed of polypropylene insulation is much higher than that of cross-linked polyethylene insulation;

[0031] 3) Compared with polyethylene insulated high-voltage cables, polypropylene insulated high-voltage cables do not require a degassing process, thus saving another 7-12 days of production time;

[0032] 4) Polypropylene materials can be recycled and reused, which is more beneficial to the environment.

[0033] In the above technical solution, the conductor 1 is made of copper monofilaments twisted together, 800mm 2 The conductors with cross-sections and below adopt circular compact structure (such as Figure 1 shown), 800mm 2 The cross section above adopts a split conductor structure (such as Figure 2 The water-blocking tape is wrapped longitudinally between each layer of the conductor, which can effectively prevent water from flowing into the cable along the conductor 1. The copper conductor is wrapped with a semi-conductive water-blocking tape 2.

[0034] The outer side of the semiconductive water-shielding tape 2 is a three-layer co-extruded structure, which is a first semiconductive polypropylene shielding layer 3, a polypropylene insulating layer 4, and a second semiconductive polypropylene shielding layer 5. The first semiconductive polypropylene shielding layer 3 and the second semiconductive polypropylene shielding layer 5 are both made of ultra-smooth semiconductive polypropylene materials, which can better homogenize the electric field. The polypropylene insulating layer 4 uses polypropylene insulating materials, which have excellent insulation properties, high production efficiency, and do not require a long degassing process.

[0035] The outer side of the second semi-conductive polypropylene shielding layer 5 is a first semi-conductive water-resistant buffer zone 6, which serves to protect the second semi-conductive polypropylene shielding layer 5 and provide longitudinal water-resistant performance for the high-voltage cable.

[0036] The outer side of the first semi-conductive water-resistant buffer zone 6 is a copper wire shielding layer 7, which serves to improve the tensile strength of the cable, and the copper wire can provide a channel for the faulty cable.

[0037] The outer side of the copper wire shielding layer 7 is a second semi-conductive water-blocking buffer zone 8, which provides a longitudinal water-blocking function for the cable.

[0038] The outer side of the second semi-conducting water-resistant buffer zone 8 is a metal sheath layer 9, which can provide a channel for the fault current. At the same time, the metal sheath layer 9 has excellent waterproof performance and provides radial water-blocking performance for the cable. As a preferred embodiment of the metal sheath layer 9 of the utility model, it can include a lead sheath layer and an asphalt coating located on the outer side of the lead sheath layer. The asphalt coating has the function of anti-corrosion and can make the lead sheath and the non-metallic outer sheath layer 10 tightly connected. The metal sheath layer 9 can also be a longitudinally wrapped aluminum-plastic composite belt, which can be a YL, YLY type aluminum-plastic composite belt, or an EL, ELE type aluminum-plastic composite belt.

[0039] The function of the non-metallic outer sheath layer 10 is to protect the internal layers of the cable from damage, and can be made of materials such as polyethylene or polyvinyl chloride.

[0040] The outer side of the non-metallic outer sheath layer 10 is an extruded semi-conductive layer or a graphite coating, which is used to facilitate line testing or maintenance work.

[0041] Example 2

[0042] like Figure 3 As shown, in this embodiment, based on the embodiment 1, an inner sheath layer 11, an aluminum wire armor layer 12 and a third semi-conductive water-resistant buffer zone 13 are further provided between the metal sheath layer 9 and the non-metallic outer sheath layer 10. The aluminum wire armor layer 12 is used to enhance the mechanical strength of the cable.

[0043] Preferably, the inner sheath layer 11 is an MDPE inner sheath layer.

[0044] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, and these simple modifications all belong to the protection scope of the present invention.

[0045] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present utility model will not further describe various possible combinations.

[0046] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A polypropylene insulated high water resistance structure high voltage cable, characterized in that: The invention comprises a conductor (1), a semiconductive water-blocking tape (2), a first semiconductive polypropylene shielding layer (3), a polypropylene insulating layer (4), a second semiconductive polypropylene shielding layer (5), a first semiconductive water-blocking buffer tape (6), a copper wire shielding layer (7), a second semiconductive water-blocking buffer tape (8), a metal sheath layer (9) and a non-metallic outer sheath layer (10) which are arranged in sequence from the inside to the outside. The conductor (1) is formed by twisting copper monofilaments, and a water-blocking tape is longitudinally wrapped between each layer of conductor. The first semiconductive polypropylene shielding layer (3), the polypropylene insulating layer (4) and the second semiconductive polypropylene shielding layer (5) are a three-layer co-extruded structure.

2. The polypropylene insulated high water resistance structure high voltage cable according to claim 1, characterized in that: The metal sheath layer (9) comprises a lead sheath layer and an asphalt coating located outside the lead sheath layer.

3. The polypropylene insulated high water resistance structure high voltage cable according to claim 1, characterized in that: The metal sheath layer (9) is a longitudinally wrapped aluminum-plastic composite tape.

4. The polypropylene insulated high water resistance structure high voltage cable according to claim 1, characterized in that: The non-metallic outer sheath layer (10) is a polyethylene or polyvinyl chloride outer sheath layer.

5. The polypropylene insulated high water resistance structure high voltage cable according to claim 1, characterized in that: The non-metallic outer sheath layer (10) is extruded with a semi-conductive layer or a graphite coating on the outside.

6. The polypropylene insulated high-water-resistance structure high-voltage cable according to any one of claims 1 to 5, characterized in that: An inner sheath layer (11), an aluminum wire armor layer (12) and a third semiconducting water-resistant buffer zone (13) are also provided between the metal sheath layer (9) and the non-metal outer sheath layer (10).

7. The polypropylene insulated high water resistance structure high voltage cable according to claim 6, characterized in that: The inner sheath layer (11) is an MDPE inner sheath layer.

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