High-strength, pressure-resistant, anti-corrosion and waterproof ultra-high-voltage power cable

Abstract

The utility model discloses a high-strength pressure-resistant anti-corrosion waterproof ultrahigh-voltage power cable, which comprises a conductor, a semi-conductive wrapping tape is wrapped outside the conductor, a conductor shielding layer, an insulating layer and an insulating shielding layer are jointly extruded outside the semi-conductive wrapping tape, and a semi-conductive buffer water-blocking tape is wrapped outside the insulating shielding layer. A quick-setting liquid rubber waterproof layer is coated outside the semi-conductive buffer water-blocking tape, an anti-impact mixed-line woven reinforcing layer is arranged outside the quick-setting liquid rubber waterproof layer, a butyl rubber water-blocking pressure-reducing layer is arranged outside the anti-impact mixed-line woven reinforcing layer, a semi-conductive buffer water-blocking composite tape is arranged outside the butyl rubber water-blocking pressure-reducing layer, and the semi-conductive buffer water-blocking composite tape is arranged outside the semi-conductive buffer water-blocking composite tape. An FEP sheath layer is extruded outside the semi-conductive buffer water-blocking composite belt, and an acrylic acid anti-corrosion paint anti-corrosion layer is arranged outside the FEP sheath layer. According to the utility model, the mechanical performance, tensile performance, flexibility, waterproof performance, corrosion resistance and the like of the cable are improved, the mechanical strength and electrical characteristics of the cable are guaranteed, the service life is prolonged, and the market demand is better satisfied.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of power cable, specifically relates to a high strength pressure -resisting corrosion -resisting waterproof type superhigh voltage power cable. BACKGROUND

[0002] In recent years, with the development of China's power grid construction and the acceleration of urbanization process, the demand for 110kV, 220kV and above high voltage grade power cable grows rapidly, and becomes the focus of investment for some powerful cable enterprises. By the end of 2023, the national power grid 66kV and above power cable in operation line is 14595 turns, and the line length is 27874km, with an annual growth of about 12%. In addition, with the rapid development of China's offshore wind power, the demand for high voltage cable presents a "blowout" state, with more than 2000km of new 66kV and above high voltage cable demand every year.

[0003] Superhigh voltage cable needs to be used in special occasions, such as the connection between coastal islands and inland, offshore oil exploration platform, seabed or water bottom power and optical signal transmission of offshore wind power field, so the cable should have excellent waterproof performance, and also have corrosion resistance and impact resistance; The existing cable commonly adopts the structure of single water blocking belt, when the cable is damaged and the damage penetrates to the conductor, the water blocking belt in the conductor gap is not enough to prevent seawater from penetrating along the conductor longitudinally, and after the cable absorbs moisture, it will occur "water tree aging" under the action of electromagnetic field, or "ablation" phenomenon occurs at the water blocking belt, which will eventually lead to cable breakdown, making the whole cable scrap, which is high in maintenance cost, long in maintenance time, large in power loss, and poor in corrosion resistance;

[0004] In addition, the cable needs to be erected and dragged for a long distance, which is easy to be subjected to slight impact force, prone to cable core structure deformation, wire core shielding layer fracture, unstable shielding effect, greatly affecting the electrical characteristics, short service life and poor durability; And after production, it is wound outside the cable shaft, which will be squeezed and bent and damaged, and the external protective sleeve will also be bent and damaged in subsequent use;

[0005] Because the voltage in high voltage and superhigh voltage cable is very high, the electric field generated is very strong, which is easy to interfere with the outside world;

[0006] In summary, the tensile property, waterproof property, corrosion resistance and flexibility of the existing superhigh voltage power cable need to be improved, so it is necessary to research and develop high strength pressure -resisting corrosion -resisting waterproof type superhigh voltage power cable to improve the mechanical property and waterproof property of the existing superhigh voltage power cable. Utility model content

[0007] In order to overcome the shortcomings of the existing technology, this utility model provides a high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable with excellent mechanical strength, impact resistance, bending resistance, water blocking performance, and corrosion resistance, which greatly improves the reliability and service life of the cable.

[0008] To achieve the above objectives, this utility model provides a high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable, comprising a conductor, a semi-conductive wrapping tape wrapped around the conductor, a conductor shielding layer, an insulation layer, and an insulation shielding layer extruded together on the outside of the semi-conductive wrapping tape, a semi-conductive water-resistant tape wrapped around the insulation shielding layer, a quick-curing liquid rubber waterproof layer coated on the outside of the semi-conductive water-resistant tape, an impact-resistant braided reinforcing layer outside the quick-curing liquid rubber waterproof layer, a butyl rubber water-blocking and pressure-reducing layer outside the impact-resistant braided reinforcing layer, a semi-conductive buffer water-blocking composite tape outside the butyl rubber water-blocking and pressure-reducing layer, an FEP sheath layer extruded on the outside of the semi-conductive buffer water-blocking composite tape, and an acrylic anti-corrosion paint anti-corrosion layer outside the FEP sheath layer.

[0009] Furthermore, the conductor is a Class 2 stranded copper conductor conforming to the GB / T3956-2008 standard.

[0010] Furthermore, the conductor shielding layer is formed by extrusion of an ultra-clean, ultra-smooth cross-linked graphene composite highly semiconductive inner shielding material with a volume resistivity of less than 20 Ω·cm at 20°C.

[0011] Furthermore, the insulation layer is extruded from ultra-clean insulation material used in ultra-high voltage cables.

[0012] Furthermore, the insulating shielding layer is extruded from an ultra-clean, ultra-smooth cross-linked graphene composite highly semi-conductive outer shielding material with a volume resistivity of less than 20 Ω·cm at 20°C.

[0013] Furthermore, the impact-resistant mixed-yarn braided reinforcing layer is woven from PBO fiber filaments with a diameter of 1-2 mm and Kevlar filaments with a diameter of 1-2 mm.

[0014] Furthermore, the butyl rubber water-blocking and pressure-reducing layer is a multi-layer overlapping and wrapping structure of butyl rubber tape, with the overlap rate of the butyl rubber tape being two-thirds of the width of the butyl rubber tape.

[0015] Furthermore, the semi-conductive buffer water-blocking composite tape includes a water-blocking tape, a semi-conductive tape, and a metal wire cloth tape, with the metal wire cloth tape attached to one side of the water-blocking tape and the semi-conductive tape attached to the other side of the water-blocking tape.

[0016] Furthermore, the water-blocking tape is made of highly absorbent cotton obtained by graft copolymerization of acrylic acid, acrylamide, and maleic anhydride.

[0017] Furthermore, the semiconductive strip includes a glass fiber layer and a uniformly electrically conductive compound adhesive layer coated on both sides of the glass fiber layer.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] 1. The inner and outer shielding layers of this cable both use graphene, which has excellent conductivity, as a conductive filler. This makes the volume resistivity, surface resistance, mechanical properties, and thermal stability of these materials superior to existing products, greatly improving the effect of homogenizing the electric field of the cable and preventing partial discharge, thereby improving the reliability and lifespan of the cable.

[0020] 2. The insulation layer of this cable is extruded using ultra-clean insulation material for ultra-high voltage cables. This solves the problem that most LDPE resins have a wide molecular weight distribution, unstable fluidity, and high impurity content. The presence of impurities can easily cause local concentration of electric field in the cable insulation, thereby leading to electrical tree breakdown and reducing the service life of the cable.

[0021] 3. The cable uses an improved impact-resistant mixed-wire braided reinforcement layer, in which the rigidity of PBO fiber is combined with the flexibility of Kevlar wire, which improves the mechanical strength, impact resistance and bending resistance of the cable. When the cable is impacted or pulled during cable laying and use, it effectively inhibits the damage to the inner layer of the cable caused by external forces, protects the mechanical strength and electrical characteristics of the cable, increases safety and reliability, extends service life and improves durability.

[0022] 4. The butyl rubber water-blocking and pressure-reducing layer in this cable is a multi-layer overlapping and wrapping structure of butyl rubber tape. The butyl rubber tape has high bonding strength and tensile strength, good elasticity and elongation performance, strong adaptability to interface deformation and cracking, and excellent chemical resistance, weather resistance and corrosion resistance. It also greatly improves the cable's tensile strength, chemical resistance, weather resistance and corrosion resistance.

[0023] 5. The cable is equipped with a multi-layer water-blocking structure consisting of a semi-conductive buffer water-blocking tape, a quick-curing liquid rubber waterproof layer, a butyl rubber water-blocking and pressure-reducing layer, and a semi-conductive buffer water-blocking composite tape from the inside out. This greatly enhances the water-blocking performance of the cable. It can inhibit and slow down the growth of water trees and prevent water from spreading longitudinally inside the cable. At the same time, for water that seeps in due to external damage, the water-blocking layer can quickly block the water and prevent it from spreading longitudinally into the cable.

[0024] 6. Metal wire tape also serves as a shield. Because the voltage inside high-voltage and ultra-high-voltage cables is very high, the electric field they generate is very strong. The shielding layer formed by the metal wire tape can effectively prevent high-voltage and ultra-high-voltage cables from interfering with the outside world. Furthermore, during normal operation, the metal wire tape can be used as a channel for capacitive current. Additionally, when a short circuit occurs in the system, the metal wire tape can also serve as a channel for short-circuit current.

[0025] 7. The cable's outer sheath uses an FEP sheath layer, giving the cable excellent chemical stability, a low coefficient of friction, superior electrical insulation, and resistance to stress cracking. FEP material has a melting point of 304℃ and exhibits a low dielectric constant over a wide temperature and frequency range, maintaining good performance within a broad temperature range of -200℃ to +200℃. It is resistant to chemicals, including strong acids, strong alkalis, and organic solvents. This chemical resistance allows FEP to remain stable in many extreme environments, thus improving the cable's corrosion resistance. It also gives the cable high mechanical strength and stiffness, enabling it to withstand greater tensile and compressive forces. Furthermore, an acrylic anti-corrosion paint layer is applied outside the FEP sheath layer, providing excellent water resistance, chemical resistance, weather resistance, and salt spray resistance, effectively preventing cable corrosion and making it suitable for use in harsh environments, thus increasing the cable's service life. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] Figure 2 This is a front view of the present invention;

[0028] Figure 3 This is a schematic diagram of the impact-resistant mixed-yarn braided reinforcing layer structure of this utility model;

[0029] Figure 4 This is a schematic diagram of the semi-conductive buffer water-blocking composite tape structure of this utility model. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0031] like Figures 1-2As shown, this utility model provides a high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable, including a conductor 1, which is wrapped with a semi-conductive wrapping tape 2. A conductor shielding layer 3, an insulation layer 4, and an insulation shielding layer 5 are extruded together on the outside of the semi-conductive wrapping tape 2. A semi-conductive buffer water-blocking tape 6 is wrapped around the insulation shielding layer 5. It has strong hygroscopicity, high expansion rate, low resistivity, and good heat resistance. It can not only block water, but also buffer and weaken the electric field strength, and has a mechanical buffering effect, reducing the damage to the cable during operation and greatly improving the safety of cable operation.

[0032] The semi-conductive buffer water-blocking strip 6 is coated with a quick-setting liquid rubber waterproof layer 7, which is a high-molecular polymer elastic waterproof material that can form a good "skin-like" non-toxic and harmless water-based waterproof and anti-corrosion layer. It also has very strong adhesion and is not easy to fall off. After film formation, the average elongation at break can reach more than 12 times and the recovery rate can reach more than 92%. Together with the semi-conductive buffer water-blocking strip 6, it forms a double-layer waterproof and corrosion-resistant structure, which greatly increases the waterproof and corrosion-resistant performance of the cable.

[0033] An impact-resistant mixed-wire braided reinforcing layer 8 is provided outside the quick-curing liquid rubber waterproof layer 7. A butyl rubber water-blocking and pressure-reducing layer 9 is provided outside the impact-resistant mixed-wire braided reinforcing layer 8. A semi-conductive buffer water-blocking composite tape 10 is provided outside the butyl rubber water-blocking and pressure-reducing layer 9. An FEP sheath layer 11 is extruded outside the semi-conductive buffer water-blocking composite tape 10. This gives the cable excellent chemical stability, low coefficient of friction, excellent electrical insulation, and resistance to stress cracking. The FEP material has a crystallization melting point of 304℃, exhibits a low dielectric constant over a wide temperature and frequency range, and has a wide temperature range of -200℃ to +200℃. It maintains good performance within a wide range; it is resistant to almost all common chemicals, including strong acids, strong alkalis and organic solvents. This chemical resistance allows FEP to remain stable in many extreme environments, thereby improving the cable's corrosion resistance. It also gives the cable high mechanical strength and stiffness, enabling it to withstand greater tensile and compressive forces. In addition, an acrylic anti-corrosion paint layer 12 is provided outside the FEP sheath layer 11, which has good water resistance, chemical resistance, weather resistance and salt spray resistance, effectively preventing the cable from being corroded. It is suitable for use in harsh environments and increases the cable's service life.

[0034] In this embodiment, conductor 1 is a type 2 stranded copper conductor conforming to the GB / T3956-2008 standard.

[0035] In this embodiment, the conductor shielding layer 3 is formed by extruding an ultra-clean, ultra-smooth cross-linked graphene composite high semiconductivity inner shielding material with a volume resistivity of less than 20 Ω·cm at 20°C; the insulating shielding layer 5 is formed by extruding an ultra-clean, ultra-smooth cross-linked graphene composite high semiconductivity outer shielding material with a volume resistivity of less than 20 Ω·cm at 20°C; both the inner and outer shielding materials use graphene with excellent conductivity as conductive filler, which makes the volume resistivity, surface resistance, mechanical properties and thermal stability of these materials better than existing products, greatly improving the effect of homogenizing the electric field of the cable, preventing partial discharge, and improving the reliability and life of the cable operation.

[0036] In this embodiment, the insulation layer 4 is extruded from ultra-clean insulation material for ultra-high voltage cables, which solves the problem that most LDPE resins have a wide molecular weight distribution, unstable fluidity, and high impurity content. The presence of impurities can easily cause local concentration of electric field in the cable insulation, thereby causing electrical tree breakdown and reducing the service life of the cable.

[0037] like Figure 3 As shown, in this embodiment, the impact-resistant braided reinforcing layer 8 is woven from PBO fiber filaments with a longitudinal diameter of 1-2 mm and Kevlar wire with a transverse diameter of 1-2 mm. The PBO fiber filaments have excellent strength, modulus, heat resistance, and flame retardancy. In particular, the strength of PBO fiber not only exceeds that of steel fiber but also surpasses that of carbon fiber. In addition, PBO fiber has excellent impact resistance, abrasion resistance, and dimensional stability, and is lightweight and flexible, which greatly improves the weight of the cable. Furthermore, the rigidity of PBO fiber filaments combined with the flexibility of Kevlar wire improves the mechanical strength, impact resistance, and bending resistance of the cable. When the cable is impacted or pulled during cable laying and use, it effectively suppresses the damage to the inner layer of the cable caused by external forces, protects the mechanical strength and electrical characteristics of the cable, increases safety and reliability, extends service life, and improves durability.

[0038] In this embodiment, the butyl rubber water-blocking and pressure-reducing layer 9 is a multi-layer overlapping and wrapping structure of butyl rubber tape, with the overlap rate of the butyl rubber tape being two-thirds of the width of the butyl rubber tape. The butyl rubber tape has high bonding strength and tensile strength, good elasticity and elongation performance, strong adaptability to interface deformation and cracking, and excellent chemical resistance, weather resistance and corrosion resistance. It also greatly improves the cable's tensile strength, chemical resistance, weather resistance and corrosion resistance.

[0039] like Figure 4As shown, in this embodiment, the semi-conductive buffer water-blocking composite tape 10 includes a water-blocking tape 101, a semi-conductive tape 102, and a metal wire cloth tape 103. The metal wire cloth tape is attached to one side of the water-blocking tape, and the semi-conductive tape is attached to the other side. The water-blocking tape is made of highly absorbent cotton obtained by graft copolymerization of acrylic acid, acrylamide, and maleic anhydride, which can inhibit and slow down the growth of water trees and prevent water from spreading longitudinally inside the cable. Simultaneously, for water that seeps in due to external damage, the water-blocking layer can quickly block the water, preventing it from spreading longitudinally into the cable. It not only serves as a water-absorbing and water-blocking material for the cable but also as a slow-release layer. It expands rapidly when exposed to water, effectively preventing water from seeping into the cable. This expansion also compensates for thermal expansion of the insulation and alleviates the compression of the cable insulation core due to lateral pressure. This allows the composite tape to meet the requirements of AC / DC medium voltage (6kV, 10kV, 15kV, ...). The water-blocking and slow-release requirements of cables such as 35kV, high voltage (66kV, 110kV, 220kV), ultra-high voltage (330kV, 500kV), polyethylene insulation (XLPE), and modified polypropylene (PP).

[0040] In addition, the metal wire tape also serves as a shield. Because the voltage inside high-voltage and ultra-high-voltage cables is very high, the electric field they generate is very strong. The shielding layer formed by the metal wire tape can effectively prevent high-voltage and ultra-high-voltage cables from interfering with the outside world. Furthermore, during normal operation, the metal wire tape can be used as a channel for capacitive current. Moreover, when a short circuit occurs in the system, the metal wire tape can also serve as a channel for short-circuit current.

[0041] Secondly, the semiconducting tape includes a glass fiber layer and a uniformly electrically conductive compound adhesive layer coated on both sides of the glass fiber layer. This can eliminate the air gap between the cable insulation layer and the external shielding layer, preventing insulation breakdown caused by air gap discharge. It can also improve the electric field distribution, reduce losses, and prevent partial discharge.

[0042] In summary, through the above improvements, this utility model solves some of the shortcomings of existing cables, greatly improves the mechanical properties, tensile strength, flexibility, waterproof performance, and corrosion resistance of the cables, ensures the mechanical strength and electrical characteristics of the cables, increases safety and reliability, extends service life, improves durability, and better meets market demands.

[0043] There are many specific applications of this utility model. The above description is only a preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this utility model, and these improvements should also be considered within the protection scope of this utility model.

Claims

1. A high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable, characterized in that: The device includes a conductor, which is wrapped with a semi-conductive wrapping tape. A conductor shielding layer, an insulation layer, and an insulating shielding layer are extruded together on the outside of the semi-conductive wrapping tape. A semi-conductive buffer water-blocking tape is wrapped around the insulating shielding layer. A quick-setting liquid rubber waterproof layer is coated on the outside of the semi-conductive buffer water-blocking tape. An impact-resistant mixed-wire braided reinforcement layer is provided on the outside of the quick-setting liquid rubber waterproof layer. A butyl rubber water-blocking and pressure-reducing layer is provided on the outside of the impact-resistant mixed-wire braided reinforcement layer. A semi-conductive buffer water-blocking composite tape is provided on the outside of the butyl rubber water-blocking and pressure-reducing layer. An FEP sheath layer is extruded on the outside of the semi-conductive buffer water-blocking composite tape. An acrylic anti-corrosion paint anti-corrosion layer is provided on the outside of the FEP sheath layer.

2. The high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The conductor used is a Class 2 stranded copper conductor conforming to the GB / T3956-2008 standard.

3. The high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The conductor shielding layer is formed by extrusion of an ultra-clean, ultra-smooth cross-linked graphene composite highly semiconductive inner shielding material with a volume resistivity of less than 20 Ω·cm at 20℃.

4. The high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The insulation layer is extruded from ultra-clean insulating material used in ultra-high voltage cables.

5. A high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The insulating shielding layer is extruded from an ultra-clean, ultra-smooth cross-linked graphene composite high semiconducting outer shielding material with a volume resistivity of less than 20 Ω·cm at 20℃.

6. The high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The impact-resistant mixed-thread braided reinforcing layer is made of PBO fiber filaments with a longitudinal diameter of 1-2 mm and Kevlar yarn with a transverse diameter of 1-2 mm.

7. A high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The butyl rubber water-blocking and pressure-reducing layer is a multi-layer overlapping and wrapping structure of butyl rubber tape, with the overlap rate of the butyl rubber tape being two-thirds of the width of the butyl rubber tape.

8. A high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 1, characterized in that: The semi-conductive buffer water-blocking composite tape includes a water-blocking tape, a semi-conductive tape, and a metal wire cloth tape. The metal wire cloth tape is attached to one side of the water-blocking tape, and the semi-conductive tape is attached to the other side of the water-blocking tape.

9. A high-strength, pressure-resistant, corrosion-resistant, and waterproof ultra-high voltage power cable according to claim 8, characterized in that: The semiconductive strip includes a glass fiber layer and a uniformly electrically conductive compound adhesive layer coated on both sides of the glass fiber layer.

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