Large-length ultrahigh-pressure submarine cable seabed efficient installation and construction method and device thereof

Abstract

The invention discloses a seabed efficient installation construction method and device for a large-length ultrahigh-pressure submarine cable, and belongs to the technical field of seabed submarine cable installation construction. S2, routing sea sweeping; s3, laying the starting end of the submarine cable on the side of the offshore wind turbine generator; s4, putting a burying machine; s5, laying and burying submarine cables; s6, recycling the burying machine; and S7, laying the submarine cable terminal at the offshore booster station side. According to the method, routing sea sweeping is carried out before construction, weather conditions are concerned, construction obstacles are removed in advance, smooth construction can be ensured, the construction period is ensured, and the construction efficiency is improved. During laying construction of the starting end of the submarine cable on the side of the offshore wind turbine generator, the barb type submarine cable protection sleeve is additionally arranged at the submarine cable inlet in the wall of the tower drum, a good protection effect on the submarine cable is achieved, and particularly, the traction head and the barb type submarine cable protection sleeve are connected in a self-breaking screw connection mode; the barb type submarine cable protection sleeve is installed on a construction ship in advance, the barb type submarine cable protection sleeve is automatically clamped into a submarine cable inlet, and therefore the problems that the installation time is long and the labor intensity is large when a diver carries out underwater installation are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine cable installation and construction, and in particular to a method and a device for efficiently installing and constructing a long-length ultra-high voltage submarine cable on the seabed. Background Art

[0002] At present, the following problems exist in the installation and construction of submarine cables between offshore booster stations and onshore switch stations: First, during construction, construction is often stopped due to emergencies, so the construction efficiency is low; second, the bottom side of the offshore wind turbine is impacted by seawater, and the submarine cable will shake, causing the tension of the submarine cable to increase, especially the submarine cable at the entrance of the submarine cable on the wall of the wind turbine tower is easily damaged; third, the bottom side of the offshore booster station is impacted by seawater, and scour pits are easily formed near the pile foundation of the offshore booster station, which often washes out the end of the J-tube, causing the submarine cable at this location to be suspended in the air, and then with the back-and-forth movement of the ocean current, the submarine cable will shake, causing the tension of the submarine cable to increase, resulting in damage to the submarine cable. Summary of the invention

[0003] The object of the present invention is to provide a method and a device for efficiently installing a long-length ultra-high voltage submarine cable on the seabed, which can ensure smooth construction.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for efficiently installing a long-length ultra-high voltage submarine cable on the seabed comprises the following steps: S1. Transfer and cable connection: The submarine cables of different specifications in the submarine cable factory are transferred and connected to the electric cable drum of the construction ship. The submarine cables of different specifications are laid separately on the electric cable drum in a concentric circle from bottom to top. During construction, the construction sequence can be temporarily changed according to the actual situation on site, and there is no need to repeatedly lay the cable. This solves the problem of large submarine cable projects in wind farms, numerous submarine cable models and specifications, and the fixed submarine cable construction sequence caused by the cable connection sequence.

[0005] S2. Route sweeping: Use the sweeping tool at the stern of the anchor boat to sweep the sea back and forth along the designed route of the submarine cable between the coastal booster station and the offshore wind turbine. When obstacles are found on the sea surface and the seabed, they are thoroughly cleared before the construction of the submarine cable; S3. Laying of the starting end of the submarine cable on the offshore wind turbine side; S4. Place the embedding machine: First, pass the submarine cable through the cable guide cage and place it in the belly of the embedding machine. Use a crane to lift the embedding machine and suspend it on the water surface. Connect the high-pressure water pump and the water supply hose of the embedding machine. Then, gently put the embedding machine and the submarine cable into the water, keeping the embedding machine level. S5. Burying the submarine cable: Bury the submarine cable in the seabed using a burying machine; S6. Recovering the embedding machine: using the crane on the construction ship to lift the embedding machine onto the construction ship; S7. Laying of submarine cable terminals on the offshore booster station side.

[0006] Furthermore, in step S1, the specific method of connecting the submarine cable is as follows: S1.1. Before the cable is connected, the performance of the submarine cable shall be tested in the submarine cable factory; S1.2. Berth the construction vessel at the submarine cable factory pier, adjust and fix the ship's position so that the center of the construction vessel's cable drum is aligned with the center of the submarine cable manufacturer's cable rack; S1.3. Transport the submarine cable along the trestle to the construction ship. The staff will tie a steel rope net on the cable head, pass the cable head through the cable rack on the construction ship, and then pull it into the electric cable drum. Before winding, leave 5m of the cable head in the electric cable drum to facilitate the cable testing. S1.4, start the electric turntable to rotate and reel in the cable; S1.5. After the transfer and cable connection is completed, remove the steel rope mesh on the cable head and re-test the performance of the cable to confirm that all performance indicators meet the engineering design requirements.

[0007] Furthermore, in step S1.4, the speed of the cable connection is controlled within 600 m / h.

[0008] Furthermore, in step S2, the anchor boat stern sea sweeping tool used is a 900HP anchor boat stern sea sweeping tool.

[0009] Furthermore, in step S3, the specific method for laying the starting end of the submarine cable on the offshore wind turbine side is as follows: S3.1. When the construction vessel sails towards the offshore wind turbine and reaches the predetermined position near the wind turbine tower, the construction vessel is positioned on the axis of the submarine cable laying route using the mooring positioning system on the construction vessel; S3.2. Accurately measure the laying length of the starting end of the submarine cable; S3.3. Use heat shrink caps to seal the cable heads on the construction ship and wrap them with waterproof tape; S3.4. Pull the cable heads out of the electric cable drum on the construction ship through the back-twist frame and into the sea through the water inlet on the side of the ship. When the cable heads are pulled out of the deck of the construction ship, set a traction head on the cable heads, connect the traction head with one end of the steel wire rope, and pass the other end of the steel wire rope through the cable entrance on the wall of the wind turbine tower, go around the pulley on the gantry at the top of the wind turbine tower, and connect with the winch on the construction ship; S3.5. Start the winch to pull the submarine cable head. At the same time, the cable laying machine on the construction ship lays the submarine cable until the submarine cable head passes through the submarine cable entrance on the wall of the wind turbine tower and moves upward to the top of the wind turbine tower, leaving enough submarine cable length and design margin; S3.6. Finally, fix the submarine cable on the tower of the offshore wind turbine to complete the laying of the starting end of the submarine cable on the offshore wind turbine side.

[0010] Further, in step S3.4, the specific method of setting the traction head on the submarine cable head is as follows: install a traction net on the submarine cable head, use the traction net to pull the submarine cable head into the barbed submarine cable protective cover, connect the traction head and the traction net, and at the same time connect the traction head and the barbed submarine cable protective cover through self-breaking screws.

[0011] Further, in step S3.5, the winch is started, and the traction force is not greater than the self-breaking force of the self-breaking screw. During the process of pulling the submarine cable head, the barbed submarine cable protective cover moves with the submarine cable until the barbed submarine cable protective cover is inserted into the submarine cable entrance on the wall of the wind turbine tower and stuck in the submarine cable entrance and cannot move. Under the continuous action of the winch, the traction force gradually increases. When the traction force is greater than the self-breaking force of the self-breaking screw, the self-breaking screw is broken, the traction head is separated from the barbed submarine cable protective cover, and the traction head pulls the submarine cable head upward in the wind turbine tower through the traction net to the top of the wind turbine tower.

[0012] Furthermore, in step S5, the specific method for burying the submarine cable is as follows: the anchor boat sets the traction anchor on the seabed in front of the construction ship according to the DGPS positioning in advance along the cable burying route; a traction winch is provided on the construction ship, one end of the traction wire on the traction winch is tied to the traction anchor in the sea, the traction winch is started, the traction wire drives the construction ship to move, the construction ship drives the burying machine to move, and the high-pressure water pump on the construction ship is started, the high-pressure water pump sucks in seawater, and the water hose supplies water to the hydraulic plow of the burying machine, the hydraulic plow cuts the seabed soil into a groove along the submarine cable burying path through hydraulic jetting, and the submarine cable is placed in the groove, and the sled at the rear of the burying machine smoothes the groove to bury the submarine cable.

[0013] Furthermore, in step S6, the method for recovering the embedding machine is as follows: when the submarine cable is laid to the predetermined position near the offshore booster station, the traction winch and the high-pressure water pump are turned off, and the anchor boat assists the construction ship, and uses DGPS navigation positioning to drop four positioning anchors to the predetermined position to fix the construction ship; the crane on the construction ship is started, and under the monitoring of the monitoring system, the embedding machine is slowly lifted off the mud surface, and the cable guide cage installed on the traction steel cable is gradually removed. During the lifting of the embedding machine and the submarine cable out of the water, the submarine cable should maintain a certain tension to prevent the submarine cable from suddenly loosening and twisting; the crane lifts the embedding machine and suspends it above the water surface, keeping the belly opening of the embedding machine and the submarine cable at the same height, and taking the submarine cable out of the embedding machine; finally, the embedding machine is lifted onto the construction ship.

[0014] Furthermore, the construction working conditions are as follows: wind conditions of level 6, sea conditions of level 3 and below, and visibility greater than 1 km.

[0015] Furthermore, when the construction vessel is carrying out burial operations, the area within 800 meters in front of the construction vessel and 300 meters behind the construction vessel is a restricted navigation zone.

[0016] Further, in step S7, the specific method for laying the submarine cable terminal on the offshore booster station side is as follows: the cable laying machine on the construction ship pulls the submarine cable through the untwisting frame, and places the submarine cable drum unwound from the electric cable drum on the deck of the construction ship; when the unwound submarine cable reaches the laying length of the submarine cable terminal, the submarine cable is cut on the construction ship; a heat shrink cap is used to seal the submarine cable head formed after cutting and a waterproof tape is wrapped around it, and a center clamp and a bending limiter are installed at a predetermined position of the submarine cable; a diver underwater checks the J-tube inlet on the offshore booster station. If the J-tube inlet has been silted up, an air sludge suction device is used to remove the J Suction out enough space at the entrance of the J-tube; the diver passes one end of the wire rope on the winch on the construction ship through the lower end of the J-tube, and the wire rope passes through the upper end of the J-tube and passes around the pulley on the gantry of the booster station and then connects with the submarine cable head on the construction ship; start the winch, and move the submarine cable head through the J-tube and upward to the offshore booster station. At this time, the guide cone on one side of the center clamp is inserted into and stuck in the lower end of the J-tube, the lower section of the bend limiter is located on the seabed, and the bend limiter is in a static free bending state; finally, fix the submarine cable to the bracket of the offshore booster station to complete the laying of the submarine cable terminal on the offshore booster station side.

[0017] Furthermore, in step S7, the submarine cable unwound from the electric cable drum is placed on the deck of the construction vessel in an 8-shaped coil.

[0018] A device used in a method for efficiently installing and constructing a long-length ultra-high voltage submarine cable on the seabed comprises a burying machine, wherein the burying machine is an HLA-4 submarine cable mechanical burying machine.

[0019] A device used in a method for efficiently installing and constructing a long ultra-high voltage submarine cable on the seabed comprises a center clamp, wherein the center clamp adopts a Haversian structure.

[0020] A device used in a method for efficiently installing and constructing a long-length ultra-high voltage submarine cable on the seabed comprises a bending limiter, wherein the bending limiter adopts a Haversian structure.

[0021] The beneficial effects of the present invention are: The present invention performs route sweeping and pays attention to weather conditions before construction, and removes construction obstacles in advance, which can ensure smooth construction, thereby guaranteeing the construction period and improving construction efficiency.

[0022] The present invention adds a barbed cable protective sleeve at the cable entrance on the wall of the wind turbine tower during the laying of the submarine cable at the beginning of the offshore wind turbine side, which plays a good protective role for the submarine cable, especially the self-breaking screw connection between the traction head and the barbed cable protective sleeve, the barbed cable protective sleeve is pre-installed on the construction ship, and when the barbed cable protective sleeve moves with the submarine cable to the cable entrance on the wall of the wind turbine tower, the barbed cable protective sleeve is automatically stuck to the cable entrance, and the barbs on the cable protective sleeve can prevent the cable protective sleeve from falling out of the cable entrance, thereby solving the problem of long installation time and high labor intensity caused by underwater installation by divers, thereby improving construction efficiency.

[0023] In the submarine cable laying process of the offshore booster station, the present invention installs a center clamp and a bending limiter on the submarine cable at the entrance of the J-tube to prevent the submarine cable from excessive bending, thereby effectively avoiding damage to the submarine cable.

[0024] The present invention transfers and connects submarine cables of different specifications in the submarine cable factory to the electric cable drum of the construction ship in the process of transferring and connecting cables. The submarine cables of different specifications are separately coiled from bottom to top on the electric cable drum in a concentric circle manner. During construction, the construction sequence can be temporarily changed according to the actual situation on site, and there is no need to repeatedly turn the cable. The present invention solves the problem that the amount of submarine cable engineering in the wind farm area is large, the types and specifications of submarine cables are numerous, and the construction sequence of the submarine cables is fixed due to the sequence of connecting cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of the method for efficiently installing and constructing a long-length ultra-high voltage submarine cable under the sea according to the present invention; Figure 2 This is a construction status diagram of laying the starting end of the submarine cable on the side of the offshore wind turbine unit of the present invention; Figure 3 This is a state diagram of the present invention after the traction head and the barbed type submarine cable protective cover are installed during the laying of the starting end of the submarine cable on the side of the offshore wind turbine; Figure 4 This is a state diagram of the traction head and the barbed submarine cable protective cover being separated after the self-breaking screw of the present invention is broken; Figure 5 It is a state diagram of the process of laying submarine cable in the present invention; Figure 6 This is a state diagram of the submarine cable laying and installation of the terminal offshore booster station of the present invention; Figure 7 This is a state diagram after the center clamp and the bending limiter of the present invention are installed.

[0026] In the figure: 1. Construction ship; 2. Offshore wind turbine; 3. Tower; 4. Wire rope; 5. Cable entrance; 6. Gantry; 7. Pulley; 8. Winch; 9. Traction head; 10. Cable head; 11. Traction net; 12. Barbed cable protection cover; 13. Self-breaking screw; 14. Cable; 15. Barb; 16. Traction winch; 17. Traction wire; 18. Traction anchor; 19. Burying machine; 20. High-pressure water pump; 21. Water hose; 22. Hydraulic plow; 23. Guard ship; 24. Cable laying machine; 25. Offshore booster station; 26. J-tube; 27. Booster station gantry; 28. Pulley; 29. ​​Center clamp; 30. Bending limiter; 31. Guide cone; 32. Conical ring; 33. Connecting shaft. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features therein can be combined with each other without conflict.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper surface", "lower surface", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "forward", "reverse", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0029] like Figure 1 As shown, a method for efficient submarine installation and construction of a long-length ultra-high voltage submarine cable is provided. The following steps are involved: S1. Cable connection: The submarine cables of different specifications from the submarine cable factory are transferred and connected to the electric cable drum of the construction ship. The submarine cables of different specifications are laid separately on the electric cable drum in a concentric circle from bottom to top. During construction, the construction sequence can be temporarily changed according to the actual situation on site, and there is no need to repeatedly lay the cable.

[0030] The specific method of submarine cable splicing is as follows: S1.1. Before connecting the cables, the performance of the submarine cables shall be tested in the submarine cable factory.

[0031] S1.2. Berth the construction vessel at the submarine cable factory wharf, adjust and fix the ship's position so that the center of the construction vessel's cable drum is aligned with the center of the submarine cable manufacturer's cable rack.

[0032] S1.3. Transport the submarine cable along the trestle to the construction ship. The staff will tie a steel rope net on the cable head, pass the cable head through the cable transmission rack on the construction ship, and then pull it into the electric cable drum. Before winding, reserve 5m of the cable head in the electric cable drum to facilitate the cable testing.

[0033] S1.4. Start the electric turntable to rotate and reel in the cable. The speed of connecting and splicing the cables should be controlled within 600m / h.

[0034] S1.5. After the transfer and cable connection is completed, the steel rope mesh is removed and the performance of the submarine cable is re-tested to confirm that all performance indicators meet the engineering design requirements.

[0035] S2, route sweeping: The 900HP anchor boat stern-mounted sweeping tool is used to sweep the sea back and forth along the designed route of the submarine cable between the coastal booster station and the offshore wind turbine. When obstacles such as aquaculture cages, piles, fishing nets, buoys on the sea surface and remaining nets, ropes, cables, piles and sunken ships on the seabed are found, they are thoroughly cleaned before the construction of the submarine cable.

[0036] S3. Laying of the starting end of the submarine cable on the offshore wind turbine side: like Figure 2 , 3 As shown in Figure 4, the specific method for laying the starting end of the submarine cable on the side of the offshore wind turbine is as follows: S3.1. The construction ship 1 sails towards the offshore wind turbine 2. When it reaches the predetermined position near the tower 3 of the wind turbine 2, the construction ship is positioned on the axis of the submarine cable laying route by using the anchoring positioning system on the construction ship 1; S3.2. The laying length of the starting end of the submarine cable is accurately measured; S3.3. The submarine cable head 10 is sealed with a heat shrink cap on the construction ship and wrapped with waterproof tape; S3.4. The submarine cable head is pulled out from the electric cable drum on the construction ship through the back-twisting frame and enters the sea through the water trough on the side of the ship. When the submarine cable head is pulled out of the deck of the construction ship, the submarine cable head 1 A traction head 9 is arranged on 0, and the traction head 9 is connected to one end of the wire rope 4. The other end of the wire rope 4 passes through the submarine cable entrance 5 on the wall 3 of the wind turbine tower, goes around the pulley 7 on the gantry 6 at the top of the wind turbine tower, and is connected to the winch 8 on the construction ship 1; S3.5, start the winch 8 to pull the submarine cable head, and at the same time, the cable laying machine on the construction ship lays the submarine cable until the submarine cable head passes through the submarine cable entrance on the wall of the wind turbine tower and moves upward to the top of the wind turbine tower, leaving enough submarine cable length and design margin; S3.6, finally fix the submarine cable on the tower of the offshore wind turbine, and complete the laying of the starting end of the submarine cable on the offshore wind turbine side.

[0037] In step S3.4, the specific method of setting the traction head on the submarine cable head is as follows: install the traction net 11 on the submarine cable head 10, use the traction net 11 to pull the submarine cable head 10 into the barbed submarine cable protective cover 12, connect the traction head 9 and the traction net 11, and connect the traction head 9 and the barbed submarine cable protective cover 12 by the self-breaking screw 13. Barbs 15 are provided on the periphery of the barbed submarine cable protective cover 12.

[0038] In step S3.5, the winch 8 is started, and the traction force is not greater than the self-breaking force of the self-breaking screw. During the pulling process of the submarine cable head, the barbed submarine cable protective cover 12 moves with the submarine cable 14 until the barbed submarine cable protective cover 12 is inserted into the submarine cable entrance 5 on the wall of the wind turbine tower and is stuck in the submarine cable entrance 5 and cannot move. Under the continuous action of the winch 8, the traction force gradually increases. When the traction force is greater than the self-breaking force of the self-breaking screw 13, the self-breaking screw 13 is broken, and the traction head 9 is separated from the barbed submarine cable protective cover 12. The traction head 9 pulls the submarine cable head 10 in the wind turbine tower 3 through the traction net 11 and moves upward to the top of the wind turbine tower.

[0039] During the construction process, if the barbed cable protective cover 12 cannot enter the cable entrance 5 on the wall 3 of the wind turbine tower and reach the designed position, the following measures are taken: the diver goes into the water to check the reason why the barbed cable protective cover 12 is stuck and the actual position of the barbed device, and transmits the information to the construction ship and the wind turbine pulling team. According to the feedback information received, the wind turbine pulling team appropriately puts back the wire rope for a certain distance, and the construction ship adjusts the ship's position to adjust the position of the barbed cable protective cover 12 to a suitable position. After confirmation by the diver, the wind turbine pulling team restarts the pulling of the barbed device, and the construction ship loosens the wire rope appropriately according to the diver's instructions, so that the barbed cable protective cover 12 enters the cable entrance 5. If the above steps still cannot enter the designated position, the construction ship will recycle the barbed cable protective cover 12 to the deck, inspect the barbed cable protective cover 12, and check whether the barbed cable protective cover 12 is damaged. If it is not damaged, the ship readjusts its position for pulling; if it is damaged, a new barbed submarine cable protective cover 12 is replaced.

[0040] S4. Launching the burying machine: first pass the submarine cable through the cable guide cage and then place it in the belly of the burying machine, use a crane to lift the burying machine and suspend it on the water surface, connect the high-pressure water pump and the water supply hose of the burying machine; then slowly put the burying machine together with the submarine cable into the water, keeping the burying machine level during the process; the burying machine used is the HLA-4 submarine cable mechanical burying machine.

[0041] S5. Laying and burying submarine cables: The submarine cable is buried in the seabed using a laying machine. The construction conditions are as follows: wind conditions of level 6, sea conditions of level 3 and below, and visibility greater than 1 km.

[0042] like Figure 5 As shown, the specific method of burying the submarine cable is as follows: the anchor boat sets the traction anchor on the seabed in front of the construction ship 1 according to the DGPS positioning in advance along the cable burying route. The construction ship 1 is provided with a traction winch 16. One end of the traction wire 17 on the traction winch 16 is tied to the traction anchor 18 in the sea. The traction winch 16 is started, and the traction wire 17 drives the construction ship 1 to move. The construction ship 1 drives the burying machine 19 to move, and the high-pressure water pump 20 on the construction ship 1 is started. The high-pressure water pump 20 sucks seawater and supplies water to the hydraulic plow 22 of the burying machine 19 through the water hose 21. The hydraulic plow 22 cuts the seabed soil into a groove along the submarine cable burying path through hydraulic jetting, and places the submarine cable 14 in the groove. The sled at the rear of the burying machine 19 smoothes the groove to bury the submarine cable 14. When the construction vessel 1 is performing burial operations, the area 800 meters in front of the construction vessel and 300 meters behind the construction vessel is a prohibited navigation area. Therefore, a warning vessel 23 is provided in front of and behind the construction vessel 1.

[0043] In this embodiment, there are two anchor boats and traction winches, and the length of the traction wire rope thrown out at one time is 1 km. The two anchor boats and two traction winches throw the traction wire rope forward alternately and uninterruptedly, avoiding the disadvantage that the cable laying ship needs to wait for one traction winch to throw the traction wire, ensuring the uninterrupted construction of submarine cable laying and improving work efficiency.

[0044] The working parameters of the burying machine are as follows: submarine cable diameter: 20mm~280mm; burying depth: 0.5m~4.0m; pulling speed: 3m~10m / min; operating water depth: 1.8m~50m; water flow resistance: 6 knots; operating towing force: 8t; ground breaking shear force: 24Kpa. The weight of the burying machine is 19t; the overall dimensions are: length×width×height is 18m×6m×5m.

[0045] S6. Recovering the Burying Machine: The crane on the construction ship is used to lift the embedding machine onto the construction ship. The method for recovering the embedding machine is as follows: when the submarine cable is laid to the predetermined position near the offshore booster station, the traction winch and the high-pressure water pump are turned off, and the anchor boat assists the construction ship to use DGPS navigation positioning to drop four positioning anchors to the predetermined position to fix the construction ship; the crane on the construction ship is started, and under the monitoring of the monitoring system, the embedding machine is slowly lifted off the mud surface, and the cable guide cage installed on the traction steel cable is gradually removed. During the lifting of the embedding machine and the submarine cable out of the water, the submarine cable should maintain a certain tension to prevent the submarine cable from suddenly loosening and twisting; the crane lifts the embedding machine and suspends it above the water surface, keeping the belly opening of the embedding machine and the submarine cable at the same height, and taking the submarine cable out of the embedding machine; finally, the embedding machine is lifted onto the construction ship.

[0046] S7. Laying of submarine cable terminals at offshore booster station side: like Figure 6As shown, the cable laying machine 24 on the construction ship 1 pulls the submarine cable through the untwisting frame, and the submarine cable unwound from the electric cable drum is placed on the deck of the construction ship in an 8-shaped coil; when the unwound submarine cable reaches the laying length of the submarine cable terminal, the submarine cable is cut on the construction ship 1; a heat shrink cap is used to seal the submarine cable head formed after cutting and a waterproof tape is wrapped around it, and a center clamp 29 and a bending limiter 30 are installed at a predetermined position of the submarine cable; a diver checks the inlet of the J-tube 26 on the offshore booster station 25 underwater. If the inlet of the J-tube 26 has been silted up, an air sludge suction device is used to flush out enough space at the inlet position of the J-tube; the diver inserts one end of the wire rope 4 on the winch 8 on the construction ship 1 into the bottom of the J-tube , the wire rope passes through the upper mouth of the J-tube and bypasses the pulley 28 on the booster station gantry 27 and is connected to the submarine cable head on the construction ship 1; start the winch 8 and adjust the traction speed according to the on-site conditions until the submarine cable head passes through the J-tube and moves upward to the offshore booster station 25, leaving enough design margin for the submarine cable. At this time, the guide cone 31 on one side of the center clamp 29 is inserted and stuck in the lower mouth of the J-tube 26, and the lower section of the bending limiter 30 is located on the seabed. The bending limiter 30 is in a static free bending state, which can effectively protect the submarine cable and ensure its bending radius to avoid damage to the submarine cable caused by excessive bending; finally, fix the submarine cable on the bracket of the offshore booster station to complete the laying of the submarine cable terminal on the offshore booster station side.

[0047] like Figure 7 As shown, in the submarine cable laying process of the terminal offshore booster station, the installation method of the center clamp and the bending limiter is as follows: 1) Determine the installation position of the center clamp on the submarine cable according to the position of the J-tube on the booster station side and the required submarine cable margin, and mark it on the submarine cable; 2) Install the middle clamp 29 at the marked position. The middle clamp 29 is a Haversian structure. After the two halves of the middle clamp are held around the submarine cable and aligned, tighten the bolts. The torque range of the bolts is 70-80 N·m. 3) Install the tapered rings 32 on both sides of the middle fixture 29, and make sure that the angles of the tapered rings are correct; 4) Install the guide cone 31 on the side of the intermediate clamp 29 on the submarine cable that is closer to the submarine cable head, and tighten the bolts. The torque range of the tightening bolts is 70-80N·m, and connect the guide cone and the intermediate clamp with screws; 5) Install the connecting shaft 33 on the other side of the middle fixture 29, hold the submarine cable, and tighten the bolts; sacrificial anode cathodic protection blocks are provided on both sides of the middle fixture, and the sacrificial anode cathodic protection blocks are used to ensure that the central fixture will not be corroded for 25 years; 6) Install the bend limiter 30 on the submarine cable. The bend limiter is a Haversian structure. After the two halves of the bend limiter hug the submarine cable 14 and align them, tighten the bolts. The torque of tightening the bolts is 150-200N·m, and the bend limiter 30 is connected to the connecting shaft 33. In the submarine cable laying process of the offshore booster station, the present invention installs a center clamp and a bend limiter on the submarine cable at the entrance of the J-tube to prevent excessive bending of the submarine cable, which can effectively avoid damage to the submarine cable. The bend limiter is made of materials such as polyurethane with high hardness, high strength, and seawater corrosion resistance. The material density is small, which meets the requirement of no additional weight on the submarine cable underwater, and the tensile strength is not less than 40MPa. The bend limiter can withstand 8t lateral pressure, and the product service life is not less than 30 years.

[0048] A device used in a method for efficiently installing and constructing a long-length ultra-high voltage submarine cable on the seabed comprises a burying machine, wherein the burying machine is an HLA-4 submarine cable mechanical burying machine.

[0049] A device used in a method for efficiently installing and constructing a long ultra-high voltage submarine cable on the seabed comprises a center clamp, wherein the center clamp adopts a Haversian structure.

[0050] A device used in a method for efficiently installing and constructing a long-length ultra-high voltage submarine cable on the seabed comprises a bending limiter, wherein the bending limiter adopts a Haversian structure.

[0051] In addition, those skilled in the art may combine and combine the different embodiments or examples and the features of the different embodiments or examples described in this specification without contradiction. Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Those skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A method for efficient submarine installation of a long-length ultra-high voltage submarine cable, characterized in that: The following steps are involved: S1. Transfer and splice: Transfer and splice submarine cables of different specifications from the submarine cable factory to the electric cable drum of the construction ship. Submarine cables of different specifications are separately coiled from bottom to top in a concentric circle on the electric cable drum; S2. Route sweeping: Use the sweeping tool at the stern of the anchor boat to sweep the sea back and forth along the designed route of the submarine cable between the coastal booster station and the offshore wind turbine. When obstacles are found on the sea surface and the seabed, they are thoroughly cleared before the construction of the submarine cable; S3. Laying of the starting end of the submarine cable on the offshore wind turbine side; S4. Place the embedding machine: First, pass the submarine cable through the cable guide cage and place it in the belly of the embedding machine. Use a crane to lift the embedding machine and suspend it on the water surface. Connect the high-pressure water pump and the water supply hose of the embedding machine. Then, gently put the embedding machine and the submarine cable into the water, keeping the embedding machine level. S5. Burying the submarine cable: Bury the submarine cable in the seabed using a burying machine; S6. Recovering the embedding machine: using the crane on the construction ship to lift the embedding machine onto the construction ship; S7. Laying of submarine cable terminals on the offshore booster station side.

2. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S1, the specific method of connecting the submarine cable is as follows: S1.

1. Before the cable is connected, the performance of the submarine cable shall be tested in the submarine cable factory; S1.

2. Berth the construction vessel at the submarine cable factory pier, adjust and fix the ship's position so that the center of the construction vessel's cable drum is aligned with the center of the submarine cable manufacturer's cable rack; S1.

3. Transport the submarine cable along the trestle to the construction ship. The staff will tie a steel rope net on the cable head, pass the cable head through the cable rack on the construction ship, and then pull it into the electric cable drum. Before winding, leave 5m of the cable head in the electric cable drum to facilitate the cable testing. S1.4, start the electric turntable to rotate and retract the cable; S1.

5. After the transfer and cable connection is completed, remove the steel rope mesh on the cable head and re-test the performance of the cable to confirm that all performance indicators meet the engineering design requirements.

3. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 2 is characterized in that: In step S1.4, the speed of the transfer and cable connection is controlled within 600m / h.

4. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S2, the mooring boat stern sea sweeping tool used is a 900HP mooring boat stern sea sweeping tool.

5. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S3, the specific method for laying the starting end of the submarine cable on the offshore wind turbine side is as follows: S3.

1. When the construction vessel sails towards the offshore wind turbine and reaches the predetermined position near the wind turbine tower, the construction vessel is positioned on the axis of the submarine cable laying route using the mooring positioning system on the construction vessel; S3.

2. Accurately measure the laying length of the starting end of the submarine cable; S3.

3. Use heat shrink caps to seal the cable heads on the construction ship and wrap them with waterproof tape; S3.

4. Pull the cable heads out of the electric cable drum on the construction ship through the back-twist frame and into the sea through the water inlet on the side of the ship. When the cable heads are pulled out of the deck of the construction ship, set a traction head on the cable heads, connect the traction head with one end of the steel wire rope, and pass the other end of the steel wire rope through the cable entrance on the wall of the wind turbine tower, go around the pulley on the gantry at the top of the wind turbine tower, and connect with the winch on the construction ship; S3.

5. Start the winch to pull the submarine cable head. At the same time, the cable laying machine on the construction ship lays the submarine cable until the submarine cable head passes through the submarine cable entrance on the wall of the wind turbine tower and moves upward to the top of the wind turbine tower, leaving enough submarine cable length and design margin; S3.

6. Finally, fix the submarine cable on the tower of the offshore wind turbine to complete the laying of the starting end of the submarine cable on the offshore wind turbine side.

6. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 5, characterized in that: In step S3.4, the specific method of setting the traction head on the submarine cable head is as follows: install a traction net on the submarine cable head, use the traction net to pull the submarine cable head into the barbed submarine cable protective cover, connect the traction head and the traction net, and connect the traction head and the barbed submarine cable protective cover through self-breaking screws.

7. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 5 is characterized in that: In step S3.5, the winch is started, and the traction force is not greater than the self-breaking force of the self-breaking screw. During the process of pulling the submarine cable head, the barbed submarine cable protective cover moves with the submarine cable until the barbed submarine cable protective cover is inserted into the submarine cable entrance on the wall of the wind turbine tower and stuck in the submarine cable entrance and cannot move. Under the continuous action of the winch, the traction force gradually increases. When the traction force is greater than the self-breaking force of the self-breaking screw, the self-breaking screw is broken, the traction head is separated from the barbed submarine cable protective cover, and the traction head pulls the submarine cable head upward in the wind turbine tower through the traction net to the top of the wind turbine tower.

8. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S5, the specific method for burying the submarine cable is as follows: the anchor boat sets the traction anchor on the seabed in front of the construction ship according to the DGPS positioning in advance along the cable burying route; the construction ship is provided with a traction winch, one end of the traction wire on the traction winch is tied to the traction anchor in the sea, the traction winch is started, the traction wire drives the construction ship to move, the construction ship drives the burying machine to move, and the high-pressure water pump on the construction ship is started, the high-pressure water pump sucks in seawater, and the water supply hose supplies water to the hydraulic plow of the burying machine, the hydraulic plow cuts the seabed soil into a groove along the submarine cable burying path through hydraulic jetting, and the submarine cable is placed in the groove, and the sled at the rear of the burying machine smoothes the groove to bury the submarine cable.

9. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S6, the method for recovering the embedding machine is as follows: when the submarine cable is laid to the predetermined position near the offshore booster station, the traction winch and the high-pressure water pump are turned off, and the anchor boat assists the construction ship to use DGPS navigation positioning to drop four positioning anchors to the predetermined position to fix the construction ship; start the crane on the construction ship, and under the monitoring of the monitoring system, slowly lift the embedding machine away from the mud surface, and gradually remove the cable guide cage installed on the traction steel cable. During the lifting of the embedding machine and the submarine cable out of the water, the submarine cable should maintain a certain tension to prevent the submarine cable from suddenly loosening and twisting; the crane lifts the embedding machine and suspends it above the water surface, keeping the belly opening of the embedding machine and the submarine cable at the same height, and taking the submarine cable out of the embedding machine; finally, lift the embedding machine onto the construction ship.

10. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: The construction working conditions are as follows: wind conditions of level 6, sea conditions of level 3 and below, and visibility greater than 1 km.

11. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1 is characterized in that: In step S5, when the construction vessel is performing burial operations, the area 800 meters in front of the construction vessel and 300 meters behind the construction vessel is a prohibited navigation area.

12. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 1, characterized in that: In step S7, the specific method for laying the submarine cable terminal on the offshore booster station side is as follows: the cable laying machine on the construction ship pulls the submarine cable through the untwisting frame, and places the submarine cable drum unwound from the electric cable drum on the deck of the construction ship; when the unwound submarine cable reaches the laying length of the submarine cable terminal, the submarine cable is cut on the construction ship; a heat shrink cap is used to seal the submarine cable head formed after cutting and a waterproof tape is wrapped around it, and a center clamp and a bending limiter are installed at a predetermined position of the submarine cable; a diver underwater checks the J-tube inlet on the offshore booster station. If the J-tube inlet has been silted up, an air sludge suction device is used to remove the J-tube inlet. Suction out enough space at the mouth of the J-tube; the diver passes one end of the wire rope on the winch on the construction ship through the lower mouth of the J-tube, and the wire rope passes through the upper mouth of the J-tube and passes around the pulley on the gantry of the booster station and then connects with the submarine cable head on the construction ship; start the winch, pass the submarine cable head through the J-tube and move it upward to the offshore booster station. At this time, the guide cone on one side of the center clamp is inserted and stuck in the lower mouth of the J-tube, the lower section of the bend limiter is located on the seabed, and the bend limiter is in a static free bending state; finally, fix the submarine cable to the bracket of the offshore booster station to complete the laying of the submarine cable terminal on the offshore booster station side.

13. The method for efficient submarine installation of a long-length ultra-high voltage submarine cable according to claim 12, characterized in that: The submarine cable unwound from the electric cable drum is placed in an 8-shaped coil on the deck of the construction vessel.

14. A device used in the method for efficiently installing a long-length ultra-high voltage submarine cable under the sea as claimed in any one of claims 1 to 13, characterized in that: The utility model comprises a burying machine, wherein the burying machine adopts an HLA-4 submarine cable mechanical burying machine.

15. A device used in the method for efficiently installing a long-length ultra-high voltage submarine cable under the sea according to claim 14, characterized in that: The utility model comprises a central clamp, wherein the central clamp adopts a Haversian structure central clamp.

16. A device used in the method for efficiently installing a long-length ultra-high voltage submarine cable under the sea according to claim 14, characterized in that: The invention comprises a bending limiter, wherein the bending limiter adopts a bending limiter with a Haversian structure.

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