Buoyancy adjustment method for deep-submersible wind power installation vessel

Abstract

The present invention discloses a buoyancy adjustment method for a deep-submersible wind power installation vessel, wherein the deep-submersible wind power installation vessel includes a floating body, an upper deck is provided on the floating body, a crane is provided on the upper deck, wherein the floating body includes a lower floating body, four columns are provided on the lower floating body, and n buoys are evenly distributed around the central axis of the lower floating body on the periphery of the lower floating body, where n is greater than or equal to 3; the adjustment method combines the calculation formula of the center of parallel force system to find the horizontal position of the center of gravity of the ship after the crane is installed on the deck, establishes n equilibrium equation expressions through the equilibrium equation of any spatial force system, and then solves the size of the buoyancy of the n buoys, further solves the water level of ballast water in the n buoys through the buoyancy calculation formula, and finally injects corresponding water level into the ballast tanks in the n buoys to achieve the balance of the overturning moment generated during the floating and sinking process of the ship, so as to improve the stability of the hull.

Description

Technical Field

[0001] The present invention relates to the field of deep-submersible marine engineering equipment, and more particularly to a buoyancy adjustment method for a deep-submersible wind power installation vessel. Background Art

[0002] Offshore wind turbine installation crane platforms (vessels), with their strong wind and wave resistance, large deck area, high variable deck load capacity, large payload capacity, wide water depth range, and multiple cabins, are the ideal carriers for ultra-large cranes. Offshore wind turbine installation crane platforms (vessels) typically perform multiple operating conditions, including maneuvering, lifting operations, and storm-proofing. These specialized operational requirements place high demands on the design of their buoyancy adjustment systems.

[0003] During vessel operations, the vessel's sinking and surfacing, as well as the compressed air deballasting system, are core systems for platform buoyancy control. The vessel's buoyancy control system is crucial. During offshore wind turbine installation crane platforms (vessels), they must maintain uniform buoyancy during buoyancy operations. After landing, free surface corrections are required to balance the capsizing moment and improve stability.

[0004] For example, the "bottom-seated water platform and its water transportation and installation method" disclosed in CN108252286B discloses that when a side or a corner of the upper platform is not level during the installation process at sea, the level of the upper platform can be adjusted by raising the cylinder segment structure. The method is: the raising and lowering mechanisms of the four raising cylinder segment structures simultaneously lift the steel cylinder to a certain set pressure (the purpose is to make the set pressures received by the four buoyancy cylinder structures basically the same), and the raising and lowering mechanisms that need to be raised for the levelness of a certain side or a certain corner continue to pressurize and raise until the upper flange surfaces of the four raising steel cylinders are basically level, and the pressures received by the four buoyancy cylinder structures are basically the same. The raising cylinder segment structure in this technical solution is relatively bulky and complex, and cannot meet the requirements of quickly and accurately adjusting the balance of the platform.

[0005] Another example is the “Ballasting system and ballasting method for a semi-submersible lifting platform” disclosed in CN107685838A, which discloses a method for overcoming the overturning moment to adjust the balance when a semi-submersible lifting platform loses balance. When there is a downward overturning moment on one side of the platform, the ballast water in the high-level ballast tank of the column on that side of the platform is discharged by gravity, and water is injected into the low-level ballast tank of the column on the other side of the platform to restore the platform to a balanced state; when there is an upward overturning moment on one side of the platform, water is injected into the low-level ballast tank of the column on that side of the platform, and the ballast water in the high-level ballast tank of the column on the other side of the platform is discharged to restore the platform to a balanced state. It adjusts the balance of the platform by discharging the ballast water in the high-level ballast tank and injecting water into the low-level ballast tank to overcome the overturning moment. However, it does not accurately disclose the specific amount of ballast water that needs to be discharged from the high-level ballast tank and the specific amount of ballast water that needs to be injected into the low-level ballast tank, nor does it disclose the relationship between the displacement and the injection volume. In other words, it does not disclose the buoyancy adjustment system that can accurately adjust the balance of the platform. Therefore, it is impossible to accurately adjust the sinking and balance of the platform to adapt to different working conditions, which is not conducive to the subsequent manufacture of offshore wind power installation crane platforms (ships) and improvement of the performance of offshore wind power installation crane platforms (ships). Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a buoyancy adjustment method for a deep-submersible wind power installation vessel which improves the stability of the vessel.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is: a buoyancy adjustment method for a deep-submersible wind power installation vessel, wherein the deep-submersible wind power installation vessel includes a lower floating body, at least four columns, and an operating platform;

[0008] The lower buoy is annular, with a moon pool running through the middle. The lower buoy is a closed hollow shell. A fixed ballast block is set at the bottom of the lower buoy. Columns are evenly arranged on the edge of the lower buoy, and a working platform is erected on the columns. A crane is installed on the working platform.

[0009] A level gauge is installed at the bottom of the lower buoy to measure the platform's submerged depth. Around the center axis of the lower buoy, n buoys are evenly distributed, with n ≥ 3. The buoys are equipped with ballast tanks that can hold ballast water for ballast removal. A spray system is installed in the lower buoy to flush out bottom sediment when the platform is floating to overcome the suction force of the platform's bottoming.

[0010] The specific steps of the buoyancy adjustment method are as follows:

[0011] Step 1: Measure the diameter D of the buoy in m, the thickness t in m, the height H in m, and the density ρ1 in kg / m3. The water level of the ballast water in the buoy i is recorded as h. i, in m, the density of the ballast water is ρ2, in kg / m3, and the buoyancy of buoy i is F i , in N, measure the horizontal distance L from the center of the deck to the center of the crane base, in m, measure the horizontal distance between the centers of n pontoons, and record the horizontal distance between pontoon j and pontoon i as L ji , the unit is m, where 1≤i≤n, 1≤j≤n-1, i≠j;

[0012] Step 2: Find the horizontal position of the center of gravity of the ship after the crane is installed on the deck through the calculation equation group (1) of the parallel force system center; the calculation equation group (1) of the parallel force system center is as follows:

[0013]

[0014] Wherein, G1 is the horizontal position of the center of gravity of the hull without the crane installed, i.e., the geometric center of the deck; G2 is the horizontal position of the center of gravity of the crane, i.e., the geometric center of the crane base; G0 is the horizontal position of the center of gravity of the hull after the crane is installed; L1 is the horizontal distance from G1 to G0, in meters; L2 is the horizontal distance from G2 to G0, in meters;

[0015] Step 3: Measure the horizontal distance between the center of each buoy and the center of gravity position G0 of the hull after the crane is installed calculated in step 2, where the horizontal distance between buoy j and the center of gravity position G0 of the hull after the crane is installed is L j0 , the unit is m, where 1≤j≤n-1;

[0016] Step 4: Calculate the buoyancy of each buoy; establish n equilibrium equations (2) through the equilibrium equations of any spatial force system, and then solve the buoyancy of the n buoys; the equilibrium equations (2) for the buoyancy of the n buoys are as follows:

[0017]

[0018] Step 5: Use the buoyancy calculation formula to calculate the required ballast water level in the n buoys; the buoyancy calculation formula is as follows:

[0019]

[0020] The water level heights of the n buoys are:

[0021]

[0022] Step 6: Fill the ballast tanks in the n buoys with water until the corresponding water levels are reached to balance the overturning moment.

[0023] The beneficial effects of the present invention are as follows: The present invention provides a buoyancy adjustment calculation method. By combining the calculation formula for the center of parallel force system, the horizontal position of the ship's center of gravity after the crane is installed on the deck is determined. N equilibrium equations are established using the equilibrium equations of arbitrary spatial force systems. The buoyancy of the n buoys is then solved. The buoyancy calculation formula is further used to determine the ballast water levels within the n buoys. Finally, the ballast water tanks within the n buoys are filled to a corresponding level to balance the capsizing moment generated during the ship's ascent and descent, thereby improving the stability of the hull. This results in a precise buoyancy adjustment calculation system that overcomes the shortcomings of the prior art and enables accurate adjustment of the platform's buoyancy and balance. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Attachment Figure 1 Side view of a deep-submersible wind turbine installation vessel.

[0025] Attachment Figure 2 A schematic diagram of a floating body with 8 pontoons.

[0026] Attachment Figure 3 A schematic diagram of a floating body with three pontoons.

[0027] Attachment Figure 4 Schematic diagram of the structure of a single buoy.

[0028] Attachment Figure 5 This is the gravity center analysis diagram of the hull.

[0029] Attachment Figure 6 This is a force analysis diagram of the hull with 8 pontoons.

[0030] Attachment Figure 7 This is a force analysis diagram of the hull with three pontoons.

[0031] Attachment Figure 8 Schematic diagram of a floating body with n buoys.

[0032] Attachment Figure 9 This is the force analysis diagram of the hull with n buoys. DETAILED DESCRIPTION

[0033] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0034] Specific embodiment 1: Figure 1 As shown, the deep-submersible wind power installation vessel includes a lower floating body 51, a column 31, and an operating platform 21.

[0035] The lower buoyancy body 51 is an annular single-shell, single-bottom structure. It is a closed hollow shell with a moonpool extending vertically through the middle of the lower buoyancy body 51. This increases the platform's heave damping, reduces the platform's heave motion, and improves the overall structural stability of the platform. A level gauge is located at the bottom of the lower buoyancy body for measuring the platform's submergence depth. N buoys 41 are evenly distributed around the circumference of the lower buoyancy body 51 around its central axis, with n ≥ 3. The buoys 41 contain ballast tanks that can hold ballast water for ballast removal. Fixed ballast blocks are located at the bottom of the lower buoyancy body 51 to lower the center of gravity of the bottom-seated mobile offshore platform and improve its stability. A spray system is also located within the lower buoyancy body 51 to flush out bottom sediment when the platform rises to overcome the suction force of the platform's bottoming.

[0036] At least four columns 31 are provided, and the columns 31 are evenly arranged on the edge of the lower floating body 51. The cross-section of the columns 31 gradually transitions from square to circular from the bottom to the top. This arrangement helps the columns 31 to generate viscous damping, has good wave resistance, and increases the stability of the platform. At the same time, during operation, the platform dives to the draft of the columns, and the waterline is circular. Compared with the square waterline, the platform's ability to resist overturning and horizontal sliding is increased; at the same time, the main part of the column has a circular cross-section, no edges, less stress concentration, and helps to extend the life of the column.

[0037] A work platform 21 is erected on the columns 31 . The work platform 21 is used for arranging deck equipment and performing installation operations. A crane 11 is provided on the work platform 21 .

[0038] Top view of floating body Figure 2 As shown, the calculation steps of the installation ship adjustment buoyancy are as follows.

[0039] Step 1: Measure the diameter D of the buoy in m, the thickness t in m, the height H in m, and the density ρ1 in kg / m3. The water level of the ballast water in the buoy i is recorded as h. i , in m, the density of the ballast water is ρ2, in kg / m3, and the buoyancy of buoy i is F i , the unit is N, then the structural diagram of the buoy is as follows Figure 5 As shown, measure the horizontal distance L from the center of the deck to the center of the crane base, in meters, and measure the horizontal distance between the centers of the eight pontoons. The horizontal distance between pontoon j and pontoon i is L ji , the unit is m, where 1≤i≤8, 1≤j≤7, i≠j;

[0040] Step 2: Calculate the horizontal position of the center of gravity. Use the equations (1) to calculate the center of gravity of the parallel force system to find the horizontal position of the center of gravity of the ship after the crane is installed on the deck. Figure 6As shown, the calculation equations for the center of the parallel force system (1) are as follows:

[0041] Wherein, G1 is the horizontal position of the center of gravity of the hull without the crane installed, i.e., the geometric center of the deck; G2 is the horizontal position of the center of gravity of the crane, i.e., the geometric center of the crane base; G0 is the horizontal position of the center of gravity of the hull after the crane is installed; L1 is the horizontal distance from G1 to G0, in meters; L2 is the horizontal distance from G2 to G0, in meters;

[0042] Step 3: Measure the horizontal distance between the center of each buoy and the center of gravity position G0 of the hull after the crane is installed calculated in step 2, where the horizontal distance between buoy j and the center of gravity position G0 of the hull after the crane is installed is L j0 , where 1≤j≤7.

[0043] Step 4: Calculate the buoyancy of each buoy. Establish 8 equilibrium equations (2) through the equilibrium equation of any force system in space, and then solve the buoyancy of the 8 buoys. The buoyancy distribution of the 8 buoys is as follows: Figure 7 As shown, the equilibrium equations (2) are as follows:

[0044]

[0045] Step 5: Use the buoyancy calculation formula to calculate the water level of the ballast water in the 8 buoys.

[0046] The buoyancy calculation formula is as follows:

[0047]

[0048] The water level heights of the 8 buoys are:

[0049]

[0050] Step 6: Fill the ballast tanks in the eight buoys with water until the corresponding water levels are reached to balance the capsizing moment and improve the stability of the hull.

[0051] Specific embodiment 2: Take three buoys as an example, the top view of the buoy is as follows Figure 3 As shown, the calculation method for adjusting the buoyancy of the installation ship is as follows:

[0052] Step 1: Measure the diameter D of the buoy in m, the thickness t in m, the height H in m, and the density ρ1 in kg / m3. The water level of the ballast water in the buoy i is recorded as h. i , in m, the density of the ballast water is ρ2, in kg / m3, and the buoyancy of buoy i is F i , the unit is N, then the structural diagram of the buoy is as follows Figure 4 As shown, measure the horizontal distance L from the center of the deck to the center of the crane base, in meters, and measure the horizontal distance between the centers of the three pontoons. The horizontal distance between pontoon j and pontoon i is L ji , the unit is m, where 1≤i≤3, 1≤j≤2, i≠j;

[0053] Step 2: Calculate the horizontal position of the center of gravity. Use the calculation formula of the center of parallel force system to find the horizontal position of the center of gravity of the ship after the crane is installed on the deck. Figure 5 As shown, the calculation formula for the center of the parallel force system is as follows:

[0054] Wherein, G1 is the horizontal position of the center of gravity of the hull without the crane installed, i.e., the geometric center of the deck; G2 is the horizontal position of the center of gravity of the crane, i.e., the geometric center of the crane base; G0 is the horizontal position of the center of gravity of the hull after the crane is installed; L1 is the horizontal distance from G1 to G0; and L2 is the horizontal distance from G2 to G0.

[0055] Step 3: Measure the horizontal distance between the center of each buoy and the center of gravity position G0 of the hull after the crane is installed calculated in step 2, where the horizontal distance between buoy j and the center of gravity position G0 of the hull after the crane is installed is L j0 , where 1≤j≤2.

[0056] Step 4: Calculate the buoyancy of each buoy. Establish three equilibrium equations through the equilibrium equation of any spatial force system, namely formula (2), and then solve the buoyancy of the three buoys. The buoyancy distribution of the three buoys is as follows: Figure 7 As shown, the equilibrium equation expression, formula (2), is as follows:

[0057]

[0058] Step 5: Use the buoyancy calculation formula to calculate the ballast water level in the three buoys. The buoyancy calculation formula is as follows:

[0059]

[0060] The water level heights of the three buoys are:

[0061]

[0062] Step 6: Fill the ballast tanks in the three buoys with water until the corresponding water levels are reached to balance the capsizing moment and improve the stability of the hull.

[0063] The present invention provides a detailed description of a specific embodiment, which can be extended to the buoyancy regulation of a deep-submersible wind power installation vessel with any number of buoys. Figure 8 A top view of a floating body with n buoys; Figure 9 This is a force analysis diagram of a ship with n buoys.)

[0064] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some embodiments of its application, and are not intended to limit the present invention. It should be noted that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A buoyancy adjustment method for a deep-submersible wind power installation vessel, wherein: The deep-submersible wind turbine installation vessel includes a lower buoy, at least four columns, and an operating platform; The lower buoy is annular, with a moon pool running through the middle. The lower buoy is a closed hollow shell. A fixed ballast block is set at the bottom of the lower buoy. Columns are evenly arranged on the edge of the lower buoy, and a working platform is erected on the columns. A crane is installed on the working platform. A level gauge is installed at the bottom of the lower buoy to measure the platform's submerged depth. Around the center axis of the lower buoy, n buoys are evenly distributed, with n ≥ 3. The buoys are equipped with ballast tanks that can hold ballast water for ballast removal. A spray system is installed in the lower buoy to flush out bottom sediment when the platform is floating to overcome the suction force of the platform's bottoming. The specific steps of the buoyancy adjustment method are as follows: Step 1: Measure the diameter D of the buoy in m, the thickness t in m, the height H in m, and the density ρ1 in kg / m3. The water level of the ballast water in the buoy i is recorded as h. i , in m, the density of the ballast water is ρ2, in kg / m3, and the buoyancy of buoy i is F i , in N, measure the horizontal distance L from the center of the deck to the center of the crane base, in m, measure the horizontal distance between the centers of n pontoons, and record the horizontal distance between pontoon j and pontoon i as L ji , the unit is m, where 1≤i≤n, 1≤j≤n-1, i≠j; Step 2: Find the horizontal position of the center of gravity of the ship after the crane is installed on the deck through the calculation equation group (1) of the parallel force system center; the calculation equation group (1) of the parallel force system center is as follows: Wherein, G1 is the horizontal position of the center of gravity of the hull without the crane installed, i.e., the geometric center of the deck; G2 is the horizontal position of the center of gravity of the crane, i.e., the geometric center of the crane base; G0 is the horizontal position of the center of gravity of the hull after the crane is installed; L1 is the horizontal distance from G1 to G0, in meters; L2 is the horizontal distance from G2 to G0, in meters; Step 3: Measure the horizontal distance between the center of each buoy and the center of gravity position G0 of the hull after the crane is installed calculated in step 2, where the horizontal distance between buoy j and the center of gravity position G0 of the hull after the crane is installed is L j0 , the unit is m, where 1≤j≤n-1; Step 4: Calculate the buoyancy of each buoy; establish n equilibrium equations (2) through the equilibrium equations of any spatial force system, and then solve the buoyancy of the n buoys; the equilibrium equations (2) for the buoyancy of the n buoys are as follows: Step 5: Use the buoyancy calculation formula to calculate the required ballast water level in the n buoys; the buoyancy calculation formula is as follows: The water level heights of the n buoys are: Step 6: Fill the ballast tanks in the n buoys with water until the corresponding water levels are reached to balance the overturning moment.

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