500kV high-voltage deepwater submarine power cable

Abstract

The invention discloses a 500kV high-pressure deepwater submarine power cable, which comprises a body, the inner layer of the body comprises at least one core wire unit (1), the outer layer of the core wire unit (1) comprises a composite pipe layer (1.1), the composite pipe layer (1.1) comprises a copper pipe (1.1. 1) and a steel pipe (1.1. 2), the copper pipe (1.1. 1) is connected with the steel pipe (1.1. 2), the steel pipe (1.1. 2) is arranged on the outer layer of the copper pipe (1.1. 1), and the copper pipe (1.1. 1) is connected with the steel pipe (1.1. 2). The outer layer of the composite pipe layer (1.1) is provided with a core wire sheath layer (1.2) made of a PE material. The invention provides a 500kV high-pressure deepwater submarine power cable which has stronger mechanical strength protection and is suitable for the water depth of below 1500m.

Description

Technical Field

[0001] The present invention relates to the field of submarine cables, and more specifically to a 500 kV high-voltage deep-sea submarine power cable. Background Art

[0002] As an energy link connecting land and sea and crossing national boundaries, submarine power cables are not only carriers of technological innovation but also key supports for the modernization of the national energy system and international cooperation. With the large-scale development of deep-sea mineral resources, far-reaching offshore wind power resources, and deep-sea oil and gas, etc., the demand for electricity use in the far-reaching sea has been greatly increased, thus increasing the high-reliability requirements for the 500 kV high-voltage deep-sea submarine power cable, which is an essential core equipment for deep-sea energy development.

[0003] Traditional 500 kV submarine cables use steel wire armor for mechanical strength protection. However, as the water depth increases to below 1500 meters, the traditional steel wire armor is prone to various failure problems under the action of marine environmental loads and tensions during service, and its strength can no longer meet the requirements of deep-sea applications. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a 500 kV high-voltage deep-sea submarine power cable that can have stronger mechanical strength protection and is applicable to water depths below 1500 meters.

[0005] The technical solution adopted by the present invention to solve the above problems is: a 500 kV high-voltage deep-sea submarine power cable, including a body. The inner layer of the body includes at least one core wire unit. The outer layer of the core wire unit includes a composite pipe layer. The composite pipe layer includes a copper pipe and a steel pipe. The copper pipe and the steel pipe are connected and arranged, and the steel pipe is arranged on the outer layer of the copper pipe. The outer layer of the composite pipe layer is provided with a core wire sheath layer made of PE material.

[0006] Compared with the prior art, the advantages of the present invention are as follows: First, the traditional deep - sea submarine power cable adopts a steel wire armor layer structure for the mechanical strength protection structure, and this steel wire armor layer structure is arranged on the outer layer of the deep - sea submarine power cable to provide overall protection for the submarine cable. However, the submarine cable of the present invention adds the design of a composite pipe layer, and uses the composite pipe layer to protect each core wire unit. Among them, the protection strength is more concentrated, the protection diameter of the composite pipe layer is smaller, it has a stronger anti - deformation ability, and its metal characteristics can effectively improve the anti - tension characteristics of the deep - sea submarine power cable, effectively reducing the geometric deformation effect caused by wind, wave, and current under the harsh conditions of the deep sea, greatly improving the adaptability of the 500kV high - voltage deep - sea submarine power cable in the deep - sea dynamic area; Second, in the deep - sea high - pressure and harsh environment, the tightness between steel wires in the steel wire armor layer is easily damaged, thus unable to meet the long - term use requirements of the deep - sea harsh environment. The composite pipe layer adopts an integral structure, has strong integrity, has no problem of loose tightness distribution, and is more adaptable to the deep - sea environment; Third, the structure of the copper pipe has good seawater corrosion resistance; Fourth, the composite pipe layer can effectively protect the electric unit from transmitting electricity, and the inner copper pipe can play an effective shielding role, reducing the circulation caused by the composite pipe layer, being able to effectively improve the cable ampacity, and having a strong short - time overload capacity, providing a high - quality transmission environment for the 500kV high - voltage submarine cable; Fifth, the composite pipe layer can be recycled and reused.

[0007] As an improvement of the present invention, the copper pipe and the steel pipe are processed and formed by the hot - rolling process of stacking copper plates and steel plates. Through this improvement, when forming the composite pipe layer, the tight fit between the copper pipe and the steel pipe is ensured, and there is no gap and no air between the two, thus better ensuring the stability of the composite pipe layer when used in the deep - sea area and being not easily deformed.

[0008] As an improvement of the present invention, in the hot - rolling process of stacking and coating copper plates and steel plates, alloying elements of silicon and manganese are added to achieve solid - solution strengthening, and it is ensured that the PREN value is not less than 30 and not more than 40. Through this improvement, silicon can not only increase the solid - solution strengthening effect but also improve the yield strength of the steel plate, and in addition to further improving the yield strength of the steel plate, manganese can also improve the toughness of the steel plate, reduce the brittle transition temperature of the steel, so that the elongation rate of the composite pipe layer reaches 30% in the tensile test, and the setting of the PREN value not less than 30 and not more than 40 can make the pitting corrosion resistance of the material better, being more suitable for the complex and harsh application environment of the deep sea.

[0009] As an improvement of the present invention, the composite tube layer is formed by longitudinal connection welding. The welding shielding gas is 98% Ar and 2% N2. Through this improvement, in general welding, Ar is usually selected as the shielding gas, but it is not the best choice for the welding of the composite tube layer used in deep - sea submarine power cables. When the purity of argon is ≥98%, it can ensure that the arc is concentrated, making the arc have better stability, reducing spatter, and improving the weld forming quality. At the same time, pure Ar as the shielding gas cannot supplement the nitrogen lost due to welding, thus affecting the yield strength, corrosion resistance, etc. of the composite tube layer. If the best welding performance is to be obtained, nitrogen elements need to be added to the shielding gas, and adding 2% N2 of the shielding gas content is the most suitable amount, which can timely supplement the nitrogen element lost at the welding point and prevent the massive precipitation of austenite.

[0010] As an improvement of the present invention, during the welding process, plasma welding is carried out first, then tungsten - inert - gas welding, and the welding temperature is controlled within 150°C - 200°C by means of multiple weldings. Through this improvement, plasma welding has the characteristics of high energy density and strong penetration, and can quickly complete the root welding, improving the welding efficiency. Moreover, plasma welding can achieve single - side welding with double - side formation, with concentrated input and small welding deformation, which is beneficial to ensuring the dimensional accuracy of the workpiece and providing a good foundation for subsequent welding. Tungsten - inert - gas welding can achieve double - side formation under the action of the shielding gas, ensuring the integrity and uniformity of welding, thus ensuring the welding quality, especially the surface quality of welding, reducing the subsequent grinding and finishing processes, and lowering the cost. The technological steps of multiple weldings and temperature control can not only prevent the influence of welding overheating on deformation, etc., but also promote the grain refinement in the heat - affected zone, improving the toughness and fatigue resistance of the welded joint. By controlling the welding temperature, the residual stress of the welded joint can be reduced, and the stability and service life of the structure can be improved.

[0011] As an improvement of the present invention, there are several uniformly distributed and embrittled welding points at the welding points. Through this improvement, in the deep - sea environment, the external of the submarine cable bears huge water pressure. By embrittling the solder joints, the solder joints can crack under a specific pressure, allowing seawater to enter the internal of the submarine cable, so as to achieve internal and external pressure balance and avoid the damage of the submarine cable due to excessive external pressure. The embrittlement of the solder joints is a controllable failure mechanism, which can avoid the catastrophic failure of the overall structure of the submarine cable under extreme pressure, thus extending the service life of the submarine cable.

[0012] As an improvement of the present invention, a cushion layer is provided inside the inner layer of the composite pipe layer. Through this improvement, since the composite pipe layer is formed by bending and wrapping a composite plate and then welded and fixed, the design of the cushion layer can ensure that the inner layer structure of the core wire unit will not be damaged during the bending and wrapping process of the composite plate. At the same time, it can ensure the tight fit of the composite pipe layer during wrapping without leaving any gap space, effectively avoiding differential pressure deformation in deep sea areas.

[0013] As an improvement of the present invention, the outer layer of the body includes an armor layer woven from carbon fiber reinforced polymer. Through this improvement, when the water depth exceeds 1500 meters, the armor strength of steel wires far fails to meet the usage requirements. The composite material CRPC (Carbon Fiber Ropes Reinforced Polymer Composite) made of synthetic carbon fiber not only meets the usage requirements of submarine cables for deep sea resource development but also greatly optimizes the manufacturing cost of submarine cables, significantly enhancing the core competitiveness of the submarine cable industry segment in the international market; the composite material of carbon fiber is mainly composed of carbon fiber reinforced polymer CFRP. This material has the characteristics of lightweight, high strength, and high stiffness. Compared with the weight of steel wire armor, it is reduced by 50%, and the cost can be directly reduced by 30%. The weaving process can make the armor layer more integral, ensuring the structural strength and structural stability of the armor layer.

[0014] As an improvement of the present invention, the armor layer includes a number of right-handed armor fiber filaments, a number of left-handed armor fiber filaments, and a circumferentially wound core fiber filament. The number of right-handed armor fiber filaments is equal to that of the left-handed armor fiber filaments, and the diameters of the right-handed armor fiber filaments, the left-handed armor fiber filaments, and the circumferentially wound core fiber filament are the same. A number of right-handed armor fiber filaments and a number of left-handed armor fiber filaments are arranged in an interleaved and interlocking manner, and the right-handed armor fiber filaments and the left-handed armor fiber filaments form a plurality of interleaved and interlocking points. The circumferentially wound core fiber filament is arranged along the interleaved and interlocking points. Through the improvement, by this braiding method, the right-handed armor fiber filaments, the left-handed armor fiber filaments, and the circumferentially wound core fiber filament can be interlocked with each other, with uniform tension distribution, protecting the anti-tensile characteristics of the deep-sea submarine power cable to the greatest extent. Moreover, the three fiber filaments will form a stable triangular structure with the edges being the fiber filaments and the angles being the interleaved and interlocking points. Any one of the fiber filaments will be superimposed on the other two fiber filaments at the corresponding interleaved and interlocking points. The circumferentially wound core fiber filament, as a connecting fiber filament, connects and shapes each right-handed armor fiber filament and each left-handed armor fiber filament, further enhancing the integrity of the armor layer. However, each triangle is an independent stable structure due to the interlocking of the interleaved and interlocking points. When damaged by impact, local damage will not cause the spread of damage and will stop at the interleaved and interlocking points, thus not causing continuous damage and being unlikely to cause the loosening of the armor layer. At the same time, the armor layer is composed of the superposition of three fiber filaments, which has a certain thickness and can effectively play a buffering role against the impact of the seabed rock formation and hard objects. On the other hand, the fiber filaments are smooth and flat, reducing the erosion and corrosion of seawater and marine organisms. While protecting the ecological environment, it maximally extends the service life of the submarine cable and protects the reliable operation of the submarine cable under extremely complex sea conditions.

[0015] As an improvement of the present invention, the angle between any two of the circumferentially wound core fiber filament, the right-handed armor fiber filament, and the left-handed armor fiber filament is 60°. Through this improvement, the triangle formed by the circumferentially wound core fiber filament, the right-handed armor fiber filament, and the left-handed armor fiber filament is an equilateral triangle, with more uniform distribution and the best stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall cross-sectional structure of the present invention.

[0017] Figure 2 is a schematic diagram of the cross-sectional structure of the core wire unit of the present invention.

[0018] Figure 3 is the armor layer of the present invention at Figure 1 an enlarged schematic diagram of the cross-section.

[0019] Figure 4 is an enlarged schematic diagram of the cross-section of the armor layer of the present invention at another cross-section.

[0020] Figure 5 It is a schematic diagram of the interlaced braided structure of the forward-spinning armor fiber filaments and the reverse-spinning armor fiber filaments of the present invention.

[0021] Figure 6 It is a schematic diagram of the interlaced braided structure of the forward-spinning armor fiber yarn, the reverse-spinning armor fiber yarn, and the circumferential core-wound fiber yarn of the present invention.

[0022] As shown in the figure: 1. Core wire unit, 1.1. Composite pipe layer, 1.1.1. Copper tube, 1.1.2. Steel tube, 1.2. Core wire sheath layer, 1.3. Cushion layer, 2. Filling support frame, 3. Water-blocking glue, 4. Rubber-coated cloth tape, 5. Inner lining layer, 6. Armor layer, 6.1. Forward-rotating armor fiber filament, 6.2. Reverse-rotating armor fiber filament, 6.3. Circumferentially wound core fiber filament, 7. PE outer sheath layer, 8. Salt water blocking tape layer. DETAILED DESCRIPTION

[0023] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0024] like Figure 1-2 As shown, a 500Kv high-voltage deep-water submarine power cable comprises a body, the inner layer of the body comprises three core wire units 1, the outer layer of the core wire unit 1 comprises a composite tube layer 1.1, the composite tube layer 1.1 comprises a copper tube 1.1.1 and a steel tube 1.1.2, the copper tube 1.1.1 is connected to the steel tube 1.1.2, and the steel tube 1.1.2 is arranged on the outer layer of the copper tube 1.1.1, and the outer layer of the composite tube layer 1.1 is provided with a core wire sheath layer 1.2 made of PE material.

[0025] The copper tube 1.1.1 and the steel tube 1.1.2 are formed by a hot rolling process of superimposing copper plates and steel plates. In the hot rolling process of superimposing copper plates and steel plates, alloy elements of silicon and manganese are added to achieve solid solution strengthening, and the PREN value is guaranteed to be not less than 30 and not more than 40. The PREN value Pitting Resistance Equivalent Number is an indicator used to evaluate the pitting resistance of stainless steel and other corrosion-resistant alloys. The composite pipe layer is formed by longitudinal connection welding. The welding shielding gas is 98% Ar and 2% N2. Plasma welding is performed first, and then tungsten inert gas welding is performed. The welding temperature is controlled within 150°C-200°C by multiple welding processes. The welding points include several evenly distributed and brittle welding points.

[0026] The inner layer of the composite pipe layer 1.1 is provided with a cushion layer 1.3.

[0027] like Figures 3-6As shown, the outer layer of the body includes an armor layer 6, which is woven from carbon fiber reinforced polymer. The armor layer 6 includes a number of right-handed armor filaments 6.1, a number of left-handed armor filaments 6.2, and a circumferential core fiber filament 6.3. The number of right-handed armor filaments 6.1 is equal to that of the left-handed armor filaments 6.2, and the right-handed armor filaments 6.1, the left-handed armor filaments 6.2, and the circumferential core fiber filament 6.3 have the same wire diameter. As Figure 5 shown, a number of right-handed armor filaments 6.1 and a number of left-handed armor filaments 6.2 are arranged in an alternating and interlocking manner, forming a plurality of alternating and interlocking points. The alternating and interlocking arrangement of the right-handed armor filaments 6.1 and the left-handed armor filaments 6.2 ensures the uniformity and comprehensiveness of the distribution of the armor layer. Then, the circumferential core fiber filament 6.3 is arranged in an alternating and interlocking manner along the alternating and interlocking points, which can connect each alternating and interlocking point and ensure the integral continuity of the number of right-handed armor filaments 6.1 and the number of left-handed armor filaments 6.2, so as to ensure the overall stability of the armor layer 6. The angle between any two of the circumferential core fiber filament 6.3, the right-handed armor filaments 6.1, and the left-handed armor filaments 6.2 is 60°. Among them, the circumferential core fiber filament 6.3 is also arranged in a spiral winding manner during actual winding, but its pitch is smaller than the wire diameter of two circumferential core fiber filaments 6.3, and its inclination angle is extremely small, making the circumferential core fiber filament 6.3 close to the setting method of winding around the circumference for one circle. Therefore, it simplifies Figure 1 , Figure 3 , Figure 4The actual pattern of the circumferentially core-wound fiber filaments 6.3, and then the right-handed armored fiber filaments 6.1 and the left-handed armored fiber filaments 6.2 are correspondingly inclined during winding based on the winding inclination angle of the circumferentially core-wound fiber filaments 6.3, so as to ensure that the basic engagement points of the circumferentially core-wound fiber filaments 6.3, the right-handed armored fiber filaments 6.1, and the left-handed armored fiber filaments 6.2 become the three corners of an equilateral triangle. Through this braiding method, the right-handed armored fiber filaments 6.1, the left-handed armored fiber filaments 6.2, and the circumferentially core-wound fiber filaments 6.3 can be engaged with each other, with uniform tension distribution, protecting the anti-tensile characteristics of the deep-sea submarine power cable to the greatest extent. Moreover, the three fiber filaments will form a stable triangular structure with the edges and the staggered engagement points as the corners. Any one of the fiber filaments will be superimposed on the other two fiber filaments above the corresponding staggered engagement points. The circumferentially core-wound fiber filaments, as connecting fiber filaments, connect and shape each right-handed armored fiber filament and each left-handed armored fiber filament, further enhancing the integrity of the armored layer. However, each triangle is an independent stable structure due to the engagement of the staggered engagement points. When damaged by impact, local damage will not cause the spread of damage and will stop at the staggered engagement points, thus not causing continuous damage and not easily causing the loosening of the armored layer. At the same time, the armored layer is composed of the superposition of three fiber filaments, which has a certain thickness and can effectively play a buffering role against impacts from the seabed rock formations and hard objects. On the other hand, the fiber filaments are smooth and flat, reducing the erosion and corrosion of seawater and marine organisms. While protecting the ecological environment, it maximally extends the service life of the submarine cable and protects the reliable operation of the submarine cable under extremely complex sea conditions.

[0028] As Figure 2 shown, the core wire unit 1 includes a conductor, a conductor lining layer, an insulating layer, and an insulating shielding layer from the inside to the outside, and then there are the cushion layer 1.3, the composite pipe layer 1.1, and the core wire sheath layer 1.2.

[0029] The three core wire units 1 are arranged circumferentially. The circumferential gaps between adjacent two core wire units 1 are filled with a filling support frame 2 so that the outer sides of the three core wire units 1 are joined together to form a circle. The inner sides of the three core wire units 1 and the connection parts between the core wire units 1 and the filling support frame 2 are filled with a water-blocking glue 3. The filling support frame 2 is made of a solid structure or a hollow structure with strengthened structure, and it is necessary to ensure that the filling support frame 2 is not easily deformed and is suitable for deep-sea areas.

[0030] The outer layers of the core wire unit 1 and the filling support frame 2 are shaped by winding with a coated adhesive tape 4. The outer layer of the coated adhesive tape 4 is successively provided with a lining layer 5 and a salt-blocking tape layer 8 from the inside to the outside. The armored layer 6 is formed on the outer layer of the salt-blocking tape layer 8. A PE outer sheath layer 7 is also provided on the outer layer of the armored layer 6. The PE outer sheath layer 7 is formed by extrusion molding to ensure the integrity of the protection area of the PE outer sheath layer and achieve a more effective anti-permeation and anti-corrosion effect.

[0031] In the design of deep - sea submarine power cables, internally, by designing the composite pipe layer 1.1 on the core unit 1, the protection intensity of the core unit 1 is more concentrated, the protection diameter of the composite pipe layer 1.1 is smaller, it has stronger anti - deformation ability, and its metal characteristics can effectively improve the anti - tension characteristics of the submarine cable. It can effectively reduce the geometric deformation caused by wind, waves and currents under harsh deep - sea conditions, and greatly improve the adaptability of the submarine cable in deep - sea dynamic areas; externally, through the design of the armor layer 6 woven by carbon fiber - reinforced polymer, in addition to the characteristics of lightweight, high strength and high stiffness of carbon fiber - reinforced polymer, it also has the characteristics of high impact resistance and anti - deformation. When local damage occurs, it is not easy to cause the diffusion effect of damage. In the reciprocating impact of ocean currents, it can also maintain good structural stability, ensuring the use safety and stability of deep - sea submarine power cables and having high adaptability in harsh deep - sea environments. At the same time, in the composite pipe layer 1.1, the design of the copper pipe 1.1.1 can be used. In addition to ensuring the seawater corrosion resistance of the core unit 1, it can effectively protect the power transmission of the electrical unit. The inner - layer copper pipe 1.1.1 can play an effective shielding role, reducing the circulating current caused by the composite pipe layer 1.1, effectively improving the current - carrying capacity of the submarine cable, and having a strong short - time overload capacity.

[0032] The above is only an illustration of the best embodiment of the present invention, but it should not be construed as a limitation of the claims. The present invention is not limited to the above - mentioned embodiments, and its specific structure is allowed to change. All changes made within the protection scope of the independent claims of the present invention are within the protection scope of the present invention.

Claims

1. A 500 kV high-voltage deep-sea submarine power cable, characterized in that: it includes a main body, the inner layer of the main body includes at least one core wire unit (1), the outer layer of the core wire unit (1) includes a composite pipe layer (1.1), the composite pipe layer (1.1) includes a copper pipe (1.1.1) and a steel pipe (1.1.2), the copper pipe (1.1.1) and the steel pipe (1.1.2) are connected and arranged, and the steel pipe (1.1.2) is arranged inside the copper pipe( The outer layer of (1.1.1), and a core wire sheath layer (1.2) made of PE material is provided on the outer layer of the composite pipe layer (1.1).

2. The 500 kV high-voltage deep-sea submarine power cable according to claim 1, wherein: The copper pipe (1.1.1) and the steel pipe (1.1.2) are processed and formed by the process of superimposing and wrapping a copper plate and a steel plate and hot rolling.

3. The 500 kV high-voltage deep-sea submarine power cable according to claim 2, wherein: In the process of superimposing and wrapping a copper plate and a steel plate and hot rolling, alloying elements of silicon and manganese are added to achieve solution strengthening, and the PREN value is ensured to be not less than 30 and not more than 40.

4. The 500 kV high-voltage deep-sea submarine power cable according to claim 3, characterized in that: The composite pipe layer is formed by longitudinal connection welding, and the welding shielding gas is 98% Ar and 2% N2.

5. The 500 kV high-voltage deep-sea submarine power cable according to claim 4, characterized in that: During the welding process, plasma welding is first carried out, then tungsten inert gas welding is carried out, and the welding temperature is controlled within 150°C - 200°C by means of multiple welding passes.

6. The 500 kV high-voltage deep-sea submarine power cable according to claim 5, characterized in that: The welding points include a number of uniformly distributed and embrittled welding points.

7. The 500 kV high-voltage deep-sea submarine power cable according to claim 1, characterized in that: A cushion layer (1.3) is provided on the inner layer of the composite pipe layer (1.1).

8. The 500 kV high-voltage deep-sea submarine power cable according to claim 1, wherein: The outer layer of the body includes an armor layer (6), and the armor layer (6) is woven with carbon fiber reinforced polymer.

9. The 500 kV high-voltage deep-sea submarine power cable according to claim 8, characterized in that: The armor layer (6) includes a number of right-handed armor fiber filaments (6.1), a number of left-handed armor fiber filaments (6.2) and a circumferential core winding fiber filament (6.3). The number of the right-handed armor fiber filaments (6.1) is equal to that of the left-handed armor fiber filaments (6.2), and the right-handed armor fiber filaments (6.1), the left-handed armor fiber filaments (6.2) and the circumferential core winding fiber filament (6.3) have the same wire diameter. A number of right-handed armor fiber filaments (6.1) and a number of left-handed armor fiber filaments (6.2) are arranged in an interleaved and meshed manner, and the right-handed armor fiber filaments (6.1) and the left-handed armor fiber filaments (6.2) form a plurality of interleaved and meshed points. The circumferential core winding fiber filament (6.3) is arranged along the interleaved and meshed points in an interleaved manner.

10. The 500 kV high-voltage deep-sea submarine power cable according to claim 9, wherein: The angle between any two of the circumferential core winding fiber filament (6.3), the right-handed armor fiber filament (6.1) and the left-handed armor fiber filament (6.2) is 60°.

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