Connecting structure of aluminum core submarine cable and connecting method thereof

Abstract

The invention provides a connecting structure of an aluminum core submarine cable and a connecting method thereof, and relates to the technical field of cables. The connecting structure of the aluminum core submarine cable comprises a submarine cable single body which comprises at least one cable core and a wrapping structure wrapping the cable core, the cable core comprises a conductor and a protective structure wrapping the conductor, and the conductor is provided with a connecting part exposed outside the wrapping structure and the protective structure; the two axial sides of the connecting pipe are provided with crimping parts, and a welding opening is formed between the crimping parts on the two sides; wherein the connecting part of one submarine cable single body is arranged in one crimping part in a penetrating manner, the connecting part or other conductive parts of the other submarine cable single body are arranged in the other crimping part in a penetrating manner, and the connecting part or other conductive parts are connected with the corresponding crimping part in a crimping manner; the welding opening is filled with a welding material, and the connecting part or other conductive parts are welded to the connecting pipe through the welding material. The connecting structure of the aluminum core submarine cable provided by the invention is firm in connection, and can meet the requirements of high voltage, large current, deepwater environment and high tension.

Description

Technical Field

[0001] The present application relates to the field of cable technology, and in particular to a connection structure of an aluminum core submarine cable and a connection method thereof. Background Art

[0002] With the rapid development of offshore wind power, the market demand for submarine cables has increased significantly. Traditional copper-core submarine cables have increased in cost due to rising copper prices, while aluminum-core submarine cables have become an attractive alternative due to their lower material cost and lightweight characteristics.

[0003] Due to the limitation of the total length of submarine cables and production equipment, it is usually necessary to connect multiple submarine cables. At present, the connection technology of aluminum core submarine cables mainly includes crimping, welding and bolting. However, in the actual production process, aluminum core submarine cables are prone to poor contact, increased resistance, insufficient mechanical strength and other phenomena at the connection, which makes it difficult to meet the needs of deep sea and high load applications. Summary of the invention

[0004] In view of the above problems, the embodiment of the present application provides a connection structure of an aluminum core submarine cable and a connection method thereof. The connection structure of the aluminum core submarine cable has a firm connection and can adapt to the requirements of high voltage, high current, deep water environment and high tension.

[0005] In order to achieve the above objectives, the embodiments of the present application provide the following technical solutions:

[0006] One aspect of the present application provides a connection structure of an aluminum core submarine cable, wherein the submarine cable monomer comprises at least one cable core and a coating structure coated on the outside of the cable core, wherein the cable core comprises a conductor and a protective structure coated on the outside of the conductor, and the conductor has a connection portion exposed outside the coating structure and the protective structure; wherein the conductor comprises a plurality of twisted and wound monofilaments, and the monofilaments are made of aluminum or aluminum alloy; and a connecting tube, wherein both axial sides are crimping portions, and a welding opening is provided between the crimping portions on both sides.

[0007] Among them, the connecting part of a submarine cable monomer is passed through one crimping part, and the connecting part or other conductive part of another submarine cable monomer is passed through the other crimping part, and the connecting part or other conductive part is crimped with the corresponding crimping part; the welding opening is filled with welding material, and the connecting part or other conductive part is welded to the connecting pipe through the welding material.

[0008] In a possible implementation manner, the end surface of the connecting portion is a welding surface, and the end surface of the connecting portion is a bevel.

[0009] In a possible implementation manner, a port on one side of the welding opening corresponding to the connecting portion is an inclined port, and an inclination direction of the inclined port is consistent with an inclination direction of an end face of the connecting portion.

[0010] In a possible implementation manner, along the circumference of the connecting pipe, the opening width of the welding opening gradually increases from the cut-off ends at both ends of the welding opening to the middle area of ​​the welding opening.

[0011] In a possible implementation manner, the protective structure includes an insulating layer, a water-blocking layer, and a non-metallic sheath which are sequentially arranged from the inside to the outside.

[0012] In a possible implementation, the covering structure includes an armor inner cushion layer, an armor layer, and an armor outer layer, which are sequentially arranged from the inside to the outside.

[0013] In a possible implementation, the submarine cable monomer includes more than two cable cores, and a filling structure is filled between adjacent cable cores.

[0014] Another aspect of the present application provides a method for connecting an aluminum core submarine cable, comprising: starting from the end of a submarine cable monomer, removing a preset length of a coating structure of the submarine cable monomer and a protective structure of a cable core to expose a connection portion of a conductor of the cable core.

[0015] The connecting part of one submarine cable unit is screwed into one crimping part of the connecting tube, and the connecting part of another submarine cable unit or other conductive parts are screwed into another crimping part of the connecting tube.

[0016] Crimping is performed on the crimping portion to which the connection portion or other conductive parts are attached.

[0017] By adopting the welding process, the welding opening of the connecting pipe is filled with welding material to weld the connecting part or other conductive parts in the connecting pipe.

[0018] In a possible implementation manner, before the connecting portion of the submarine cable monomer is screwed into the connecting pipe, the method further includes: cutting the end face of the connecting portion into a bevel; and welding the end face of the connecting portion.

[0019] In a possible implementation manner, before the welding material is filled into the welding opening of the connecting pipe, the method further includes: arranging a cooling assembly on the outer periphery of the connecting pipe.

[0020] The present application provides a connection structure and a connection method of an aluminum core submarine cable, wherein the connection structure of the aluminum core submarine cable includes a submarine cable monomer and a connecting tube. The submarine cable monomer includes at least one cable core, and a coating structure is arranged outside the cable core. The cable core includes a conductor and a protective structure coated on the outside of the conductor, and the conductor is formed by twisting and winding a plurality of monofilaments, and the monofilaments are made of aluminum or aluminum alloy. Among them, the conductor has a connection portion exposed outside the coating structure and the protective structure, and the connection portion is used to connect with the connecting tube. The connecting tube is provided with a crimping portion on both axial sides, and a welding opening is provided between the crimping portions on both sides. When connecting the aluminum core submarine cable, first, the connection portion of a submarine cable monomer is screwed into a crimping portion of the connecting tube, and the connection portion of another submarine cable monomer or other conductive parts is screwed into another crimping portion of the connecting tube, and the connection portion of the submarine cable monomer and the crimping portion of the connecting tube, or other conductive parts and the crimping portion of the connecting tube are tightly combined together through the crimping process. Then, the connection portion of the submarine cable monomer or other conductive parts are welded to the connecting tube by filling the welding material in the welding opening. In this way, two submarine cable monomers or submarine cable monomers and other conductive parts are connected together by a connection method combining crimping and welding, and the connection method is simple and easy to operate. In addition, the connection of the aluminum core submarine cable is firm and reliable, and the aluminum core submarine cable can adapt to the requirements of high voltage, high current, deep water environment and high tension. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 A schematic diagram of the structure of the connection structure of the aluminum core submarine cable provided in an embodiment of the present application;

[0023] Figure 2 A schematic cross-sectional view of a submarine cable monomer provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of the structure of two submarine cable monomers connected in an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the structure of a single submarine cable unit connected to other conductive parts provided in an embodiment of the present application;

[0026] Figure 5 A flowchart of the steps of the connection method of the aluminum core submarine cable provided in an embodiment of the present application.

[0027] Description of reference numerals:

[0028] 100-submarine cable monomer; 200-connecting pipe; 300-conductive part; 400-cooling assembly; 500-thermocouple;

[0029] 110-cable core; 120-cladding structure; 130-filling structure; 140-optical fiber unit; 210-crimping portion; 220-welding opening;

[0030] 111-conductor; 112-protection structure; 113-connecting part; 121-armor inner cushion layer; 122-armor layer; 123-armor outer layer; 124-tape layer;

[0031] 1111-monofilament; 1121-insulating layer; 1122-water blocking layer; 1123-non-metallic sheath; 1124-metal shielding layer; 1125-conductor shielding layer; 1126-insulating shielding layer;

[0032] 11221-longitudinal water blocking layer; 11222-radial water blocking layer;

[0033] a-first longitudinal water-blocking layer; b-second longitudinal water-blocking layer. DETAILED DESCRIPTION

[0034] As mentioned in the background technology, the development of renewable energy and the surge in demand for intercontinental data communications have driven the construction of offshore wind farms and international Internet infrastructure, which has led to a continuous increase in demand for submarine cables. The copper core submarine cables commonly used at present are becoming more and more expensive due to the continuous rise in copper prices. In contrast, aluminum materials are cheaper and have a lower density, making aluminum core submarine cables lighter, easier to install and maintain, and showing a broad market space.

[0035] When production equipment is limited or the submarine cable laying journey is long, it is necessary to connect two sections of cable. At present, the commonly used connection methods for aluminum core cables include crimping, welding and bolting. Among them, crimping is the most commonly used connection method. By pressing the end of the aluminum core cable into the connecting tube, the aluminum core cable and the connecting tube are firmly connected. Welding is to connect the aluminum core cable with another aluminum core cable or conductive part by welding. Bolted connection uses bolts to apply strong pressure on the part of the aluminum core cable to make the aluminum core cable tightly pressed together to achieve connection.

[0036] However, due to the poor creep resistance of aluminum, crimping can easily cause the aluminum core cable connector to loosen under high voltage and current changes. Although welding can provide a strong connection, it requires professional equipment and may damage the conductor surface. Bolt connectors are expensive, have strict processing requirements, and have low mechanical strength. They are difficult to apply to submarine cables with large water depths and high loads, which limits the widespread application of aluminum core submarine cables.

[0037] In view of this, an embodiment of the present application provides a connection structure of an aluminum core submarine cable and a connection method thereof, wherein the connection structure of the aluminum core submarine cable includes a submarine cable monomer and a connecting tube. The submarine cable monomer includes at least one cable core, and a coating structure is arranged outside the cable core. The cable core includes a conductor and a protective structure coated on the outside of the conductor, and the conductor is formed by twisting and winding a plurality of monofilaments, and the monofilaments are made of aluminum or aluminum alloy. Among them, the conductor has a connection portion exposed outside the coating structure and the protective structure, and the connection portion is used to connect with the connecting tube. The connecting tube is provided with a crimping portion on both axial sides, and a welding opening is provided between the crimping portions on both sides. When connecting the aluminum core submarine cable, first, the connection portion of a submarine cable monomer is screwed into a crimping portion of the connecting tube, and the connection portion of another submarine cable monomer or other conductive parts is screwed into another crimping portion of the connecting tube, and the connection portion of the submarine cable monomer and the crimping portion of the connecting tube, or the other conductive parts and the crimping portion of the connecting tube are tightly combined together through the crimping process. Then, the connection portion of the submarine cable monomer or other conductive parts are welded to the connecting tube by filling the welding material in the welding opening. In this way, two submarine cable monomers or submarine cable monomers and other conductive parts are connected together by a connection method combining crimping and welding, and the connection method is simple and easy to operate. In addition, the connection of the aluminum core submarine cable is firm and reliable, and the aluminum core submarine cable can adapt to the requirements of high voltage, high current, deep water environment and high tension.

[0038] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application.

[0039] Figure 1 This is a schematic diagram of the structure of the connection structure of the aluminum core submarine cable provided in the embodiment of the present application. Figure 1 As shown, an embodiment of the present application provides a connection structure of an aluminum core submarine cable. The connection structure of the aluminum core submarine cable includes a submarine cable monomer 100 and a connecting tube 200. When the distance to be covered exceeds the length limit of a single submarine cable monomer 100, two submarine cable monomers 100 can be connected through a connecting tube 200 to extend the transmission distance of the aluminum core submarine cable. Alternatively, in the event that the submarine cable monomer 100 is damaged or other submarine cable monomers 100 need to be replaced, the damaged portion of the submarine cable monomer 100 can be cut off, and a new submarine cable monomer 100 can be connected through the connecting tube 200, avoiding the need to replace the entire submarine cable, which is beneficial to cost saving and ensuring the stability of communication or power transmission.

[0040] Figure 2A schematic cross-sectional view of a submarine cable monomer provided in an embodiment of the present application. The submarine cable monomer 100 includes a cable core 110, and the cable core 110 includes a conductor 111, and the conductor 111 is formed by twisting and winding a plurality of monofilaments 1111. The conductor 111 is a main conductive element and can be used to transmit current. The conductor in the embodiment of the present application is an aluminum conductor or an aluminum alloy conductor. Compared with the currently commonly used copper conductor, the price of aluminum conductor is lower, which can effectively reduce the manufacturing cost of the submarine cable monomer 100; and the density of aluminum is lower, which is conducive to reducing the weight of the submarine cable monomer 100 and facilitating the installation and maintenance of the submarine cable monomer 100; in addition, since aluminum materials are easy to process and manufacture, the cable core 110 is made of aluminum conductor, and the manufacturing process is relatively simple, which effectively improves production efficiency.

[0041] Continue to refer to Figure 2 As shown, the internal gap of the conductor 111 may be filled with a water-blocking material (not shown in the figure). Exemplarily, the water-blocking material may be an insulating or semi-conductive water-blocking adhesive structure, and the water-blocking material may play a role of longitudinal water blocking.

[0042] In addition, the cable core 110 further includes a protective structure 112 covering the conductor 111 .

[0043] The protection structure 112 includes an insulating layer 1121 , a water-blocking layer 1122 , and a non-metallic sheath 1123 which are sequentially arranged from the inside to the outside.

[0044] Among them, the insulating layer 1121 is used to isolate the high voltage electrode from the ground electrode, and its quality directly determines the long-term operating reliability of the submarine cable in the power system of the corresponding voltage level. Therefore, the insulating layer 1121 needs to have excellent electrical properties, heat resistance, anti-aging properties and other characteristics. Exemplarily, the insulating layer 1121 can adopt an extruded cross-linked polyethylene structure.

[0045] The water blocking layer 1122 may include a longitudinal water blocking layer 11221 and a radial water blocking layer 11222 arranged in sequence from the inside to the outside. The longitudinal water blocking layer 11221 may be a wrapped semi-conductive water-resistant tape structure, which may be used to prevent longitudinal water penetration and ensure the product performance of the submarine cable during operation and salvage and repair. The radial water blocking layer 11222 is used to further achieve radial water blocking requirements. Exemplarily, the radial water blocking layer 11222 may be an aluminum-plastic composite tape structure, the thickness of the aluminum tape is about 0.5 mm, and the cable core 110 is coated in a longitudinal manner.

[0046] In addition, the longitudinal water-blocking layer 11221 may be provided with two layers, which are defined as a first longitudinal water-blocking layer a and a second longitudinal water-blocking layer b from the inside to the outside. A metal shielding layer 1124 may be provided between the first longitudinal water-blocking layer a and the second longitudinal water-blocking layer b, and the metal shielding layer 1124 may play the role of short-circuit current discharge, mechanical protection, and electric field shielding. The metal shielding layer 1124 may serve as a low-voltage electrode of the working electric field, providing a path for capacitive current and fault current.

[0047] The metal shielding layer 1124 can be wound around the outside of the first longitudinal water-blocking layer a by means of an aluminum monofilament winding structure, and then an aluminum tape is sparsely wound around the outside of the aluminum monofilament to tighten and fix the aluminum monofilament winding structure. The surface coverage of the aluminum monofilament winding is greater than 97%, the number of aluminum monofilaments can be calculated based on the short-circuit current and the coverage, and the outer diameter of the aluminum monofilament is not less than 1.2 mm. In this way, sufficient mechanical protection can be provided for the insulating layer 1121.

[0048] Of course, in order to meet the longitudinal and radial water blocking requirements at great water depths, the gaps between the first longitudinal water blocking layer a and the second longitudinal water blocking layer b, as well as the gaps in the metal shielding layer 1124, may also be filled with semiconducting water-repellent glue.

[0049] The non-metallic sheath 1123 mainly plays the role of mechanical protection, anti-electrochemical corrosion, electrical insulation protection, moisture and water resistance for the submarine cable monomer 100. Therefore, the non-metallic sheath 1123 needs to have good chemical resistance, water resistance, and thermal aging resistance. Exemplarily, the non-metallic sheath 1123 can be an extruded semi-conductive polyethylene structure, or it can also be an insulating polyethylene structure, which is not specifically limited in this embodiment.

[0050] In addition, in order to form a stable and smooth dielectric surface between the conductor 111 and the insulating layer 1121, and to ensure that the insulating layer 1121 is protected from the influence of the internal and external structures, a semi-conductive shielding material may be extruded on the outer surface of the conductor 111 to form a conductor shielding layer 1125. The conductor shielding layer 1125 may make the dielectric interface of the conductor 111 toward the insulating layer 1121 as smooth as possible, which is beneficial to improving the electric field distribution on the metal electrode surface and improving the dielectric strength of the insulating surface.

[0051] Similarly, a semi-conductive shielding material may be extruded on the surface of the insulating layer 1121 to form an insulating shielding layer 1126 to ensure that the dielectric surface between the insulating layer 1121 and the metal shielding layer 1124 is stable and smooth.

[0052] Combination Figure 1 and Figure 2As shown, the submarine cable monomer 100 further includes a coating structure 120, which is coated on the outside of the cable core 110. The coating structure 120 includes an armor inner cushion layer 121, an armor layer 122 and an armor outer layer 123 which are sequentially arranged from the inside to the outside.

[0053] The armor inner cushion layer 121 can be used to bind the cable core 110 and can play a role in buffering and protecting the cable core 110. For example, the armor inner cushion layer 121 can be formed by winding a relatively soft polypropylene rope with good chemical resistance and wear resistance.

[0054] The armor layer 122 can be formed by twisting and twisting light and high-strength metal wires. For example, the armor layer 122 can be formed by twisting and twisting one or two layers of aluminum alloy wires. The armor layer 122 can provide mechanical protection for the laying and operation of the submarine cable monomer 100, and can also play a role in short-circuit leakage, which is conducive to ensuring the long-term and reliable operation of the submarine cable monomer 100. The armor layer 122 can also be coated with an anti-corrosion layer such as asphalt to prevent seawater corrosion.

[0055] The armored outer layer 123 can play a role of buffering and protection during the production and construction of the submarine cable monomer 100 and can also serve as a submarine cable identification function. For example, the armored outer layer 123 can also be formed by winding a polypropylene rope.

[0056] In addition, continue to refer to Figure 2 As shown, the submarine cable monomer 100 may also include an optical fiber unit 140. During the cabling process of the submarine cable monomer 100, the optical fiber unit 140 is integrated into the structure of the submarine cable monomer 100, and can transmit a large amount of data with extremely high bandwidth and low latency. In addition, the optical fiber unit 140 can also monitor the temperature and strain of the submarine cable in real time. In addition, the optical fiber unit 140 can also identify and locate the fault point of the submarine cable monomer 100 by measuring the reflection and loss of the optical signal. It is conducive to the rapid maintenance of the submarine cable monomer 100, reducing downtime and improving production efficiency.

[0057] In a possible implementation, the submarine cable monomer 100 may include multiple cable cores 110. When the submarine cable monomer 100 includes more than two cable cores 110, a filling structure 130 is filled between adjacent cable cores 110, and the filling structure 130 can ensure the roundness of the submarine cable monomer 100 after cabling. At the same time, the filling structure 130 can also protect the optical fiber unit 140 from being squeezed.

[0058] In addition, when the submarine cable monomer 100 includes a plurality of cable cores 110, the submarine cable monomer 100 may further include a tape layer 124, and the tape layer 124 is used to bundle the submarine cable monomer 100 after cabling.

[0059] It should be noted that when the distance to be covered exceeds the length limit of a single submarine cable monomer 100, it is often necessary to connect two submarine cable monomers 100 through a connecting tube 200 to extend the transmission distance of the aluminum core submarine cable.

[0060] In order to achieve the connection of the submarine cable monomer 100 in the connecting tube 200 , the conductor 111 needs to have a section exposed outside the coating structure 120 and the protective structure 112 , and this section is defined as the connecting portion 113 .

[0061] In addition, crimping portions 210 are provided at both axial ends of the connection pipe 200 , and a welding opening 220 is provided between the crimping portions 210 on both sides.

[0062] When the submarine cable monomer 100 is connected to the connecting tube 200, the connecting portion 113 of the submarine cable monomer 100 is first screwed into the crimping portion 210 of the connecting tube 200, and then the connecting portion 113 and the crimping portion 210 are tightly combined together through a crimping process.

[0063] Figure 3 This is a schematic diagram of the structure of two submarine cable monomers connected. Figure 3 As shown, when two submarine cable monomers 100 need to be connected together, firstly, the connecting portion 113 of one submarine cable monomer 100 is inserted into the crimping portion 210 on one side of the connecting tube 200, and the connecting portion 113 of another submarine cable monomer 100 is inserted into the crimping portion 210 on the other side of the connecting tube 200, and the connecting portions 113 and the crimping portions 210 on both sides are respectively crimped to be tightly combined together. Then, the welding material is filled in the welding opening 220 of the connecting tube 200, and the connecting portions 113 of the two submarine cable monomers 100 are respectively welded to the connecting tube 200. In this way, the connection of the two submarine cable monomers 100 is completed.

[0064] Of course, the connection structure of the aluminum core submarine cable is not limited to connecting two submarine cable monomers 100 together, but can also be connecting one submarine cable monomer 100 with other conductive parts. Figure 4 This is a schematic diagram of the structure of a single submarine cable monomer 100 connected to a conductive member 300 provided in an embodiment of the present application. Figure 4 As shown, the connection structure of the aluminum core submarine cable may also include a conductive member 300, the conductive member 300 is screwed into the crimping portion 210 on one side of the connecting tube 200, and the conductive member 300 and the crimping portion 210 are combined together by crimping, a submarine cable monomer 100 is screwed into the crimping portion 210 on the other side of the connecting tube 200, and the submarine cable monomer 100 and the crimping portion 210 are also crimped together. Then, the welding material is filled at the welding opening 220 of the connecting tube 200, and the connecting portion 113 of the submarine cable monomer 100 and the connecting tube 200 as well as the conductive member 300 and the connecting tube 200 are welded together.

[0065] The conductive member 300 may be a sensor or monitoring device, and the submarine cable monomer 100 is connected thereto to collect marine environment data. Alternatively, the conductive member 300 may also be a substation or other power equipment, and the submarine cable monomer 100 is connected thereto to transmit the power generated by the wind farm to the land power grid. The specific form of the conductive member 300 is not limited in this embodiment.

[0066] It should be noted that, when welding, it is usually necessary to first weld each single wire 1111 in the conductor 111 together. Therefore, in order to increase the welding area between the single wires 1111 during welding, the end face of the connecting portion 113 can be cut into an inclined surface, so that the welding between the single wires 1111 can be more secure. In addition, the side port corresponding to the welding opening 220 and the connecting tube 200 can be set as an inclined port, and the inclined direction of the inclined port is consistent with the inclined direction of the end face of the connecting portion 113. In this way, the contact area between the conductor 111 and the welding material can be increased during welding, so that the welding strength is higher.

[0067] In addition, since the welding port is set as an inclined port, the opening width of the welding opening 220 gradually increases from the cut-off ends at both ends of the welding opening 220 to the middle area of ​​the welding opening 220 along the circumference of the connecting pipe 200, wherein the cut-off ends are the cut-off parts at both ends of the welding opening 220 in the circumferential direction, and the middle part of the welding opening 220 is the top of the longitudinal section, that is, along the circumferential direction, the welding opening 220 is a shape with a large middle and small ends. In this way, during welding, since the opening gradually expands from the bottom to the top on the longitudinal section of the crimping portion 210, the accumulation of solder gradually increases, which can increase the welding strength. In addition, due to the setting of the inclined end face, the welding opening 220 can be made larger, the welding material can be more easily entered into the welding opening 220, and the filling is dense, which is convenient for welding operation.

[0068] Figure 5 A flowchart of the steps of the connection method of the aluminum core submarine cable provided in the embodiment of the present application. Figure 5 As shown, the embodiment of the present application also provides a connection method of an aluminum core submarine cable, the connection method comprising the following steps:

[0069] S100, starting from the end of the submarine cable monomer, removing a preset length of the coating structure of the submarine cable monomer and the protective structure of the cable core to expose the connection part of the cable core.

[0070] Before connecting the submarine cable monomer 100, it is first necessary to determine the length of the connecting portion 113 of the submarine cable monomer 100 according to the voltage level of the submarine cable monomer 100 and the length of the connecting tube 200. Specifically, the length of the crimping portion 210 of the connecting tube 200 is defined as d. In order to ensure that the subsequent conductor 111 can be better restored to the outer diameter of the body, a preset length can be reserved when removing the coating structure 120 of the submarine cable monomer 100. Exemplarily, starting from the end of the submarine cable monomer 100, the coating structure 120 and the protective structure 112 of the submarine cable monomer 100 with a length of (d+15) cm can be removed to expose the connecting portion 113 of this part of the cable core 110.

[0071] After that, the water-blocking material of the conductor 111 at the location of the connection portion 113 is processed. After cleaning the water-blocking material of the conductor 111, each monofilament 1111 is ultrasonically cleaned using alcohol or acetone to remove residues and impurities on the surface of the monofilament 1111 and ensure the cleanliness of the surface of the monofilament 1111.

[0072] After cleaning, a high temperature resistant semi-conductive paste is applied to each monofilament 1111. In addition, a throat clamp is used to tighten the monofilament 1111 at the connection portion 113. The use of the throat clamp can ensure the stability of the monofilament 1111 during the connection process and prevent the monofilament 1111 from loosening. The 15 cm portion reserved in the connection portion 113 is cut off to ensure that the difference between the outer diameter of the conductor 111 after restoration and the outer diameter of the body is less than 0.2 mm.

[0073] In a possible implementation, in order to facilitate the subsequent connection work, the end surface of the connection part 113 can be surface treated. First, the end of the connection part 113 is cut into a certain tapered angle. Exemplarily, starting from the end of the connection part 113, the end can be cut at a distance of 1 to 2 cm from the end of the connection part 113, so that the end of the connection part 113 forms an inclined plane with an angle of -75 to -65° with the horizontal direction. In this way, the area of ​​the welding part of the connection part 113 can be increased in the subsequent welding process, so that the welding is more firm and reliable. After cutting, the end can be cleaned with alcohol or acetone to remove the residue that may be generated during the cutting process.

[0074] Afterwards, the aluminum monofilaments 1111 at the ends of the connection parts 113 are welded together, and illustratively, argon arc welding can be used to weld them together along the inclined surface of the ends of the connection parts 113. After welding, the ends of the connection parts 113 can be carefully polished using tools such as an angle grinder or a file to remove welding slag on the surface of the ends of the connection parts 113.

[0075] S200, screwing a connecting portion of a submarine cable unit into a crimping portion of a connecting tube, and screwing a connecting portion or other conductive member of another submarine cable unit into another crimping portion of the connecting tube.

[0076] Prepare the connecting tube 200 , screw the connecting portion 113 of one submarine cable unit 100 into one crimping portion 210 of the connecting tube 200 , and screw the connecting portion 113 of another submarine cable unit 100 into the other crimping portion 210 of the connecting tube 200 .

[0077] It can be understood that when the submarine cable monomer 100 is connected to other conductive parts 300, at this time, the connecting part 113 of one submarine cable monomer 100 is screwed into one crimping part 210 of the connecting tube 200, and the other conductive parts 300 are screwed into the crimping part 210 on the other side of the connecting tube 200.

[0078] Exemplarily, a high temperature resistant semi-conductive paste may be coated on the inner wall of the crimping portion 210 , so that the contact resistance between the connecting portion 113 and the crimping portion 210 may be effectively reduced and the conductivity thereof may be increased.

[0079] S300, crimping a crimping portion on which a connecting portion or other conductive parts are installed.

[0080] After the connection part 113 or other conductive member 300 is screwed into the crimping part 210, the crimping part 210 with the connection part 113 or other conductive member 300 installed is crimped so that the connection part 113 and the crimping part 210 can be tightly combined together, or the other conductive member 300 and the crimping part 210 can be tightly combined together. Exemplarily, during crimping, the four side walls of the crimping part 210 can be crimped once each, the crimping width can be set to 50mm to 60mm, and the compression rate can be controlled at 13% to 16%.

[0081] S400, using a welding process, filling a welding material into a welding opening of the connecting pipe to weld the connecting part or other conductive parts into the connecting pipe.

[0082] After the connection part 113 or other conductive member 300 is crimped together with the crimping part 210 , welding material is filled into the welding opening 220 of the connection pipe 200 to weld the connection pipe 200 and weld the connection part 113 or other conductive member 300 into the connection pipe 200 .

[0083] For example, the welding material can be aluminum alloy welding wire, and the aluminum alloy welding wire is melted by argon arc welding for welding and filling. Appropriate welding parameters should be used during the welding process. For example, the welding current can be controlled at 150-220A to avoid common problems such as cold welding and pores.

[0084] It should be noted that, since the side port corresponding to the welding opening 220 and the connecting portion 113 is set as an inclined port, the opening gradually expands from the bottom to the top in the longitudinal section, and the welding material accumulation gradually increases. Therefore, when welding, welding can be carried out in sequence from the inside to the outside and from the bottom to the top to ensure the integrity of the weld. In addition, by welding from the bottom to the top, the effect of gravity can be used to make the molten solder fill the weld better. The welding strength can be effectively increased.

[0085] After welding is completed, a local resistance test is required for the welding part, and it is ensured that the resistance of the welding part does not exceed the resistance of the conductor 111 body to ensure the efficiency and safety of current transmission. After the resistance test is qualified, the welding part is polished with an appropriate grinding tool such as a grinding wheel or a polishing machine to make the welding surface smooth and eliminate possible burrs or irregular sharp parts.

[0086] During the welding process, especially when welding at high current or for a long time, a large amount of heat is generated. Therefore, in a possible embodiment, after the crimping work of the connecting portion 113 or other conductive member 300 and the crimping portion 210 is completed, and before the welding material is filled into the welding opening 220 of the connecting pipe 200, a cooling assembly 400 (see Figure 1 The cooling assembly 400 can effectively absorb the heat generated during the welding process, prevent the welding part from overheating, and thus reduce thermal deformation and stress concentration.

[0087] For example, a copper bar cooling system may be installed on the outer periphery of the connecting pipe 200, and the temperature of the copper bar cooling water may be set to 5°C.

[0088] In addition, a thermocouple 500 (see Figure 1 As shown), and connect it to the temperature monitoring system to realize real-time temperature monitoring and alarm functions of the welding part. Exemplarily, two thermocouples 500 can be respectively arranged on both sides of the connection structure of the aluminum core submarine cable. The thermocouple 500 is arranged at one end of the connection part 113 away from the welding opening 220, and the two thermocouples on each side can be symmetrically arranged along the radial direction of the cable monomer 100. In addition, the temperature threshold of the thermocouple 500 can be set to 130°C. Once the temperature exceeds this limit, the system will immediately issue an alarm, and the welding operation will be suspended at this time to prevent the submarine cable monomer 100 from being damaged due to overheating. When the temperature drops below 50°C, the welding work can be resumed again.

[0089] Finally, the connection structure of the aluminum core submarine cable of this embodiment was subjected to 200 thermal cycle tests. The results showed that the temperature at the connection of the submarine cable monomer 100 was lower than the body temperature of the submarine cable monomer 100, and there was no poor contact or increased resistance, avoiding the overheating of the connecting pipe 200. In addition, in the tensile test of the conductor 111 connection, its tensile strength reached or exceeded 75MPa. These test results show that the connection structure of the aluminum core submarine cable of the embodiment of the present application has excellent reliability and stability in ensuring electrical and mechanical properties.

[0090] The various embodiments or implementation methods in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referenced to each other.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A connection structure of an aluminum core submarine cable, characterized in that: include: A submarine cable monomer (100) comprises at least one cable core (110) and a coating structure (120) coated outside the cable core (110), wherein the cable core (110) comprises a conductor (111) and a protective structure (112) coated outside the conductor (111), and the conductor (111) has a connection portion exposed outside the coating structure (120) and the protective structure (112); wherein the conductor (111) comprises a plurality of twisted and wound monofilaments (1111), and the monofilaments (1111) are made of aluminum or an aluminum alloy; The connecting pipe (200) has crimping parts (210) on both axial sides, and a welding opening is provided between the crimping parts (210) on both sides; The connecting portion (113) of one submarine cable monomer (100) is inserted into one of the crimping portions (210), and the connecting portion (113) of another submarine cable monomer (100) or other conductive member is inserted into another of the crimping portions (210), and the connecting portion (113) or the other conductive member is crimped to the corresponding crimping portion (210); the welding opening (220) is filled with welding material, and the connecting portion (113) or the other conductive member is welded to the connecting tube (200) through the welding material.

2. The connection structure according to claim 1, characterized in that: The end surface of the connecting portion (113) is a welding surface, and the end surface of the connecting portion (113) is an inclined surface.

3. The connection structure according to claim 2, characterized in that: A port on one side of the welding opening (220) corresponding to the connecting portion (113) is an inclined port, and the inclination direction of the inclined port is consistent with the inclination direction of the end surface of the connecting portion (113).

4. The connection structure according to claim 3, characterized in that: Along the circumference of the connecting pipe (200), from the cut-off ends at both ends of the welding opening (220) to the middle area of ​​the welding opening (220), the opening width of the welding opening (220) gradually increases.

5. The connection structure according to any one of claims 1 to 4, characterized in that: The protective structure (112) comprises an insulating layer (1121), a water-blocking layer (1122) and a non-metallic sheath (1123) which are arranged in sequence from the inside to the outside.

6. The connection structure according to any one of claims 1 to 4, characterized in that: The covering structure (120) comprises an armored inner cushion layer (121), an armored layer (122) and an armored outer layer (123) which are arranged in sequence from the inside to the outside.

7. The connection structure according to any one of claims 1 to 4, characterized in that: The submarine cable monomer (100) comprises more than two cable cores (110), and a filling structure (130) is filled between adjacent cable cores (110).

8. A method for connecting an aluminum core submarine cable, applied to the connection structure according to any one of claims 1 to 7, characterized in that: The connection method includes: Starting from the end of the submarine cable monomer (100), a predetermined length of the coating structure (120) of the submarine cable monomer (100) and the protective structure (112) of the cable core (110) are removed to expose the connection portion (113) of the conductor (111) of the cable core (110); Screw the connection part (113) of one submarine cable monomer (100) into a crimping part (210) of the connecting tube (200), and screw the connection part (113) of another submarine cable monomer (100) or other conductive member into another crimping part (210) of the connecting tube (200); Crimping the crimping portion (210) on which the connecting portion (113) or other conductive member is installed; A welding process is adopted to fill the welding opening of the connecting pipe (200) with welding material, so as to weld the connecting portion (113) or other conductive parts inside the connecting pipe (200).

9. The connection method according to claim 8, characterized in that: Before the connecting portion (113) of the submarine cable monomer (100) is screwed into the connecting pipe (200), the method further comprises: Cutting the end surface of the connecting portion (113) into a bevel; The end surface of the connecting portion (113) is welded.

10. The connection method according to claim 8, characterized in that: Before the welding opening (220) of the connecting pipe (200) is filled with welding material, the method further comprises: A cooling component is arranged on the outer periphery of the connecting pipe (200).

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