Floating marine platform and the manufacturing thereof
Patent Information
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-04-10
- Publication Date
- 2023-10-16
Smart Images
Figure TWG2TA000930102_001 
Figure TWG2TA000930102_002 
Figure TWG2TA000930102_003
Abstract
Description
[Technical Field]
[0001] This invention relates to a floating offshore platform and a method for manufacturing the same. [Previous Technology]
[0002] Background of the Invention
[0003] The present invention relates to a method for manufacturing a floating offshore platform, the floating offshore platform comprising a central column, a plurality of peripheral columns surrounding the central column, and an outrigger extending radially from the central column, which connects the peripheral columns to the central column.
[0004] Floating offshore platforms can, for example, be used to support offshore wind turbines used for power generation. As wind turbines become larger, economies of scale dictate that the largest wind turbines will be used in megawatt-class wind farms. To support these very large wind turbines, these floating offshore platforms are also becoming increasingly larger. [Summary of the Invention]
[0005] Summary of the Invention
[0006] In the conventional approach, floating offshore platforms can be made from prefabricated components, which are then welded together at a final assembly site. The welding process requires adjustments to the length of the components, which may cause slight eccentricity when internal loads are transferred to these structural elements. This process is time-consuming due to the time required for final adjustments and welding, including inspection, final repairs, and coating repair around the welds.
[0007] In an alternative configuration, the floating offshore platform is constructed from prefabricated components bolted together at the final assembly site. This process is similar to current wind turbine manufacturing and assembly methods, where components such as tower sections, nacelles, and blades are fitted with flanged connectors and bolted together at the final assembly site. Due to the geometry of the floating offshore platform, these flanges must be aligned with extremely high precision to be joined together. A typical required tolerance is 1 mm, while a tolerance of approximately 5 mm is typically assumed for conventional large steel structures. Achieving the required high precision is very complex and costly, as the tighter tolerances can only be achieved using high-precision dimensional marking tools that perform laser-based measurements, at increased cost. Furthermore, the thermal expansion or contraction of these components can affect their assembly capability unless corrected for in the dimensional surveys that estimate the thermal expansion or contraction. This can lead to components not fitting correctly to each other, or an additional risk of misalignment in internal load transfer.
[0008] Floating offshore platforms are manufactured in large shipyards and then towed to wind farm sites. However, such large shipyards are rare and may be located far from wind farm sites. Long-distance transportation of large floating offshore platforms is very expensive and time-consuming. The offshore wind power industry increasingly demands that such floating offshore platforms be manufactured efficiently and simultaneously become larger. Therefore, developing very large wind farms using known strategies may not be economical.
[0009] One object of the present invention is to provide a method for manufacturing a floating offshore platform that remains efficient as the size of the floating offshore platform increases with the size of the wind turbine to be supported.
[0010] The present invention provides a method for manufacturing a floating offshore platform by means of a support, wherein the floating offshore platform includes a central column, a plurality of peripheral columns surrounding the central column, and outriggers extending radially from the central column, which connect the peripheral columns to the central column. The central column includes a central column perimeter wall, and an upper central column mounting member and a lower central column mounting member spaced apart from each other and connected to the central column perimeter wall. Each of the peripheral columns includes a peripheral column perimeter wall, and an upper peripheral column mounting member and a lower peripheral column mounting member spaced apart from each other and connected to the peripheral column perimeter wall. Each of the outriggers includes an outrigger structure connected to an upper inner outrigger mounting member aligned with the upper central column mounting member, a lower inner outrigger mounting member aligned with the lower central column mounting member, an upper outer outrigger mounting member aligned with the upper peripheral column mounting member, and a lower outer outrigger mounting member aligned with the lower peripheral column mounting member. The bearings include an inner extended support bearing, an outer extended support bearing, a central column bearing, and a peripheral column bearing. The inner extended support bearing includes an inner extended support bearing spacer connected to an upper inner extended support bearing interface and a lower inner extended support bearing interface. The outer extended support bearing includes an outer extended support bearing spacer connected to an upper outer extended support bearing interface and a lower outer extended support bearing interface. The central column bearing includes a central column bearing spacer connected to an upper central column bearing interface and a lower central column bearing interface. The peripheral column bearing includes a peripheral column bearing spacer connected to an upper peripheral column bearing interface and a lower peripheral column bearing interface. The method includes the following steps: At a first temperature and a first position, a first pair is formed using the inner extended support bearing and the central column bearing, wherein the interface of the upper inner extended support bearing is aligned with the interface of the upper central column bearing, and the interface of the lower inner extended support bearing is aligned with the interface of the lower central column bearing. At a second temperature and a second position, a second pair is formed using the outer extended support bearing and the peripheral column bearing, wherein the interface of the upper outer extended support bearing is aligned with the interface of the upper peripheral column bearing, and the interface of the lower outer extended support bearing is aligned with the interface of the lower peripheral column bearing. At a third temperature and at a third position, at least one of the cantilever brackets is manufactured using the inner cantilever bracket bearing and the outer cantilever bracket bearing, during which the interface of the upper inner cantilever bracket bearing is aligned with the upper inner cantilever bracket mounting member, the interface of the lower inner cantilever bracket bearing is aligned with the lower inner cantilever bracket mounting member, the interface of the upper outer cantilever bracket bearing is aligned with the upper outer cantilever bracket mounting member, and the interface of the lower outer cantilever bracket bearing is aligned with the lower outer cantilever bracket mounting member. At a fourth temperature and at a fourth position, at least one peripheral column is manufactured using the peripheral column bearing.During this process, the upper peripheral column bearing interface is aligned with the upper peripheral column mounting component, and the lower peripheral column bearing interface is aligned with the lower peripheral column mounting component. At a fifth temperature and a fifth position, the central column is manufactured using the central column bearing. During this process, the upper central column bearing interface is aligned with the upper central column mounting component, and the lower central column bearing interface is aligned with the lower central column mounting component. Finally, at a sixth temperature and a sixth position, the floating offshore platform is assembled.
[0011] The method of the present invention uses an inner extendable support seat and an outer extendable support seat to manufacture the extendable support, uses a central column support seat to manufacture the central column, and uses a peripheral column support seat to manufacture the peripheral column. The inner extendable support seat and the central column support seat are paired before becoming the first pair at the first position at a first temperature, and the outer extendable support seat and the peripheral column support seat are paired before becoming the second pair at the second position at a second temperature. After pairing, the seats are separated and used to manufacture the extendable support at the third position at a third temperature, and to manufacture the central column and the peripheral column respectively at the fourth position at a fourth temperature and at the fifth position at a fifth temperature.
[0012] At the third, fourth, and fifth positions, the cantilever supports, peripheral columns, and central column can be constructed according to the tolerances commonly used in the steel construction industry, while using the mating bearings according to the invention. At the sixth position, the floating offshore platform is assembled at the sixth temperature. At the third position, any thermal expansion or contraction of the material will have the same dimensional effect on the external cantilever support bearings and the internal cantilever support bearings, as well as the assembly of the cantilever support to be manufactured. At the fourth position, any thermal expansion or contraction of the steel will have the same dimensional effect on the peripheral column bearings and the assembly of the peripheral column to be manufactured. At the fifth position, any thermal expansion or contraction of the steel will have the same dimensional effect on the central column bearings and the assembly of the central column to be manufactured. In this way, it is ensured that the cantilever support is perfectly connected to the central column and the peripheral columns at the sixth position. This allows the central column, peripheral columns, and cantilever support manufactured in different factories to be assembled in another factory. The ability to select such factories to enable the manufacturing operation to be carried out effectively.
[0013] The selected workshops may use various dimensional control tools. Ultimately, the workshops must use the bearings to ensure compliance with the required tolerance levels at the interfaces, practically the interface planes. To achieve strict tolerances, the workshops may use the bearings as part of their manufacturing sequence to properly assemble and weld the end connections to the columns or overhangs. Alternatively or otherwise, in particular, the workshops may use the bearings solely for the assembly and adjustment of the subassemblies and remove them for final welding. If welding is expected to cause deformation, such deformation should be considered during the assembly and welding process to ensure that the bearings still fit the components after welding.
[0014] In one embodiment, the bearing interfaces are aligned with and adjacent to the mounting components of the floating offshore platform.
[0015] In one embodiment, the bearing interfaces are aligned with and installed onto the mounting components of the floating offshore platform, thereby ensuring the correct position of the floating offshore platform.
[0016] In one embodiment, the bearing interfaces and the mounting members include mounting flanges that abut against each other and are screwed together.
[0017] In one embodiment, the bearing interfaces are aligned with the mounting components of the floating offshore platform with a tolerance of less than 1 mm.
[0018] In one embodiment, at least one of the first temperature, second temperature, third temperature, fourth temperature, fifth temperature and sixth temperature is different from the other temperature.
[0019] In one embodiment, at least one of the first, second, third, fourth, fifth and sixth positions is more than 100 kilometers away from the other positions.
[0020] In one embodiment, the floating offshore platform includes structural members spanning between each adjacent pair of peripheral columns, wherein the method includes the step of installing the structural members after installing the outriggers between the central column and the peripheral columns, wherein the structural members are pre-tensioned.
[0021] The aspects and features described and shown in the specification can be applied individually where possible. These individual aspects, especially those aspects and features described in the appended claim, can serve as the subject matter of a divisional patent application.
Implementation Method
[0023] Figure 1 shows a floating offshore platform 1, in this example supporting a wind turbine 300 to form a floating wind turbine 5. The wind turbine 300 has a vertical tower 301 and a nacelle 302 located on top of the tower 301, the nacelle 302 having an internal generator driven by a wind turbine rotor 303. The wind turbine rotor 303 has a hub 304 connected to the generator, and in this example, three blades 305 extending from the hub 304. The wind turbine 300 is capable of generating more than 1 megawatt (MW) of electricity, currently reaching approximately 10 to 12 MW. For a +10 MW wind turbine, the base diameter of the tower 301 can be between 5 meters and 10 meters. The length of the three blades 305 can each exceed 100 meters. An example is the 12 MW Haliade X wind turbine from General Electrics. Other wind turbine designs, such as vertical axis wind turbines, can also be supported by this floating offshore platform 1.
[0024] Figure 2 shows the offshore platform 1 without wind turbine 300 and without access roads, railings and installation facilities to illustrate some of the manufacturing steps of its structural components.
[0025] As shown in Figures 2 and 5B, the offshore platform 1 includes a central column 10 made of steel. The central column 10 has a vertically cylindrical upper peripheral wall section 11, which is closed by a top wall 17 and, in this embodiment, merges downwards with a vertically cylindrical lower peripheral wall section 13 via a flared or conically widened intermediate peripheral wall section 12. The bottom of the lower peripheral wall section 13 is closed by a bottom wall 14 to define an inner chamber 16. The central column 10 has a diameter at the upper peripheral wall section 11 that is approximately equal to the bottom diameter of the tower 301, and this diameter increases towards the bottom or keel of the central column 10 via the conically widened intermediate peripheral wall section 12. The central column 10 may have a foot (not shown) below the base wall section 13, which has a larger diameter to provide additional volume. When the foot is filled with air, it helps to support the weight of the wind turbine 300. When the base is filled with water, it helps to provide stability for the floating wind turbine 5.
[0026] In this example, the offshore platform 1 includes three vertical cylindrical stabilizing columns or peripheral columns 30 made of steel. These peripheral columns 30 are arranged radially around the central column 10 at 120-degree intervals. Each peripheral column 30 includes a vertical cylindrical peripheral wall 31, closed at its upper side by a top wall 32 to form an inner cavity 34 open at its bottom side. Each peripheral column 30 includes a horizontally extending skirt 33 surrounding the bottom edge of the cylindrical peripheral wall 31.
[0027] The offshore platform 1 includes three outriggers 50 extending radially between the central column 10 and the peripheral columns 30. These outriggers 50 are made of steel and, in this example, consist of an upper tubular member 51 and a lower tubular member 52 extending parallel to each other, interconnected by diagonal tie rods 53. Alternatively, at least one of the upper tubular member 51 and the lower tubular member 52 may be diagonally opposite to the other. Alternatively, the upper tubular member 51 and the lower tubular member 52 may be separate components, not interconnected by tie rods. As best shown in Figure 3B, the extension brackets 50 include an upper external extension bracket mount 54 at the end of the upper tubular member 51, having an upper external extension bracket mount flange 64; and an upper internal extension bracket mount 55, having an upper internal extension bracket mount flange 65; and at the end of the lower tubular member 52, a lower external extension bracket mount 56, having a lower external extension bracket mount flange 66; and a lower internal extension bracket mount 57, having a lower internal extension bracket mount flange 67.
[0028] As shown in Figures 2 and 5B, the central column 10 includes three upper central column mounts 20 and three lower central column mounts 25 for the outriggers 50. Each of the upper central column mounts 20 includes a tubular section 21 welded to the upper peripheral wall section 11 and an upper central column mounting flange 22 located at its end side. Each of the lower central column mounts 25 includes a tubular section 26 welded to the lower peripheral wall section 13 and a lower central column mounting flange 27 located at its end side. The upper inner outrigger mounting flange 55 is aligned with and screwed against the upper central column mounting flange 22, and the lower inner outrigger mounting flange 57 is aligned with and screwed against the lower central column mounting flange 27.
[0029] As shown in Figures 2 and 4B, each of the peripheral posts 30 includes an upper peripheral post mounting member 35 and a lower peripheral post mounting member 38. The upper peripheral post mounting member 35 includes a tubular section 36 welded to the upper side of the peripheral wall 31, and an upper peripheral post mounting flange 37 located at its end side. The lower peripheral post mounting member 38 includes a tubular section 39 welded to the lower side of the peripheral wall 31, and a lower peripheral post mounting flange 40 located at its end side. The upper external extension bracket mounting flange 54 is aligned with and screwed to the upper peripheral post mounting flange 37, and the lower external extension bracket mounting flange 56 is aligned with and screwed to the lower peripheral post mounting flange 40.
[0030] The offshore platform 1 includes three pre-tensioned, slender upper structural members or steel tendons 60, having the same length and interconnected with the upper ends of the peripheral columns 30, and three pre-tensioned, slender lower structural members or steel tendons 65, having the same length and interconnected with the lower ends of the peripheral columns 30 at the skirts 33. The steel tendons 60 and 65 are embodied in steel pipes. Due to the pre-tensioning in the steel tendons 60 and 65 and the compressive forces induced in the overhanging supports 50, the entire offshore platform 1 needs to be constructed within strict tolerances to prevent eccentricity in the internal load transfer.
[0031] The central column 10 has a base diameter of up to 20 meters. The central column 10 and the peripheral columns 30 typically have a total height of 20-30 meters, approximately 24 meters in this example. The peripheral columns 30 have a diameter between 6 and 12 meters. The steel tendons 60 and 65 each have a length of 60-90 meters, approximately 73 meters in this example.
[0032] Figures 3A and 3B show the two stages of manufacturing the outriggers 50 of the offshore platform 1 by means of an external outrigger support 120 and an internal outrigger support 140.
[0033] The external extension support 120 is made of steel and includes a spacer tube 121, an upper external extension support interface 122, and a lower external extension support interface 125. The upper external extension support interface 122 includes a tubular section 123 welded to the upper side of the spacer tube 121, and an upper external extension support mounting flange 124 located at its end side. The lower external extension support interface 125 includes a tubular section 126 welded to the lower side of the spacer tube 121, and a lower external extension support mounting flange 127. The external extension support 120 includes several feet 130 located on the spacer tube 121, and the tubular sections 123 and 126 hold the upper external extension support mounting flange 124 and the lower external extension support mounting flange 127 at clearly defined positions and heights.
[0034] The internal extended support bracket 140 is made of steel and includes a spacer tube 141, an upper internal extended support bracket interface 142, and a lower internal extended support bracket interface 145. The upper internal extended support bracket interface 142 includes a tubular section 143 welded to the upper side of the spacer tube 141, and an upper internal extended support bracket mounting flange 144 located at its end side. The lower internal extended support bracket interface 145 includes a tubular section 146 welded to the lower side of the spacer tube 141, and a lower internal extended support bracket mounting flange 147. The internal extended support bracket 140 includes several feet 150 located on the spacer tube 141, and the tubular sections 143 and 146 hold the upper internal extended support bracket mounting flange 144 and the lower internal extended support bracket mounting flange 147 at clearly defined positions and heights.
[0035] During the manufacture of the extended bracket 50, the upper external extended bracket mounting flange 64 is aligned with and temporarily installed or screwed to the upper external extended bracket support mounting flange 124, and the lower external extended bracket mounting flange 66 is aligned with and temporarily installed or screwed to the lower external extended bracket support mounting flange 127. The upper internal extended bracket mounting flange 65 is aligned with and temporarily installed or screwed to the upper internal extended bracket support mounting flange 144, and the lower internal extended bracket mounting flange 67 is aligned with and temporarily installed or screwed to the lower internal extended bracket support mounting flange 147. All operations are performed within a tolerance of less than 1 mm. The external cantilever support 120 and the internal cantilever support 140 are mutually positioned according to the final exact positions of the cantilever support mounting flanges 64, 65, 66, and 67, the upper tubular member 51, and the lower tubular member 52, and the diagonal tie rods 53 are positioned therein. They are also supported at a precise height by a plurality of tubular supports 131 with a tolerance of less than 1 mm. Finally, the cantilever support mounting flanges 64, 65, 66, and 67 are welded against the ends of the tubular members 51 and 52.
[0036] Figures 4A and 4B show a two-stage process for manufacturing the peripheral columns 30 of the offshore platform 1 of Figure 2 using peripheral column bearings 160. The peripheral column bearing 160 includes a spacer tube 161, an upper peripheral column bearing interface 162, and a lower peripheral column bearing interface 165. The upper peripheral column bearing interface 162 includes a tubular section 163 welded to the upper side of the spacer tube 161, and an upper peripheral column bearing mounting flange 164 located at its end side. The lower peripheral column bearing interface 165 includes a tubular section 166 welded to the lower side of the spacer tube 161, and a lower peripheral column bearing mounting flange 167 located at its end side. The peripheral column support 160 includes a top support 170 and a top seat 171 located at its end, an intermediate support 178 and an intermediate seat 179 therewith, and a bottom support 175 and a bottom seat 176 therewith.
[0037] During the manufacture of the peripheral columns 30, the skirt 33 is welded to the bottom edge of the peripheral wall 31. The upper peripheral column mounting flange 37 is aligned with and temporarily installed or screwed to the upper peripheral column bearing mounting flange 164, and the lower peripheral column mounting flange 40 is aligned with and temporarily installed or screwed to the lower peripheral column bearing mounting flange 167. All operations are performed within a tolerance of less than 1 mm. The peripheral column bearing 160 is positioned and temporarily installed against the peripheral wall 31 by means of the top seat 171, the middle seat 179 and the bottom seat 176. The top seat 171 is coupled to a lug 41 located on the peripheral wall 33, and the middle seat 179 and the bottom seat 176 are screwed against the peripheral wall 33 within a tolerance of less than 1 mm. The tubular segments 36 and 39 are positioned and their ends are individually welded to the upper peripheral post mounting flange 37 and the peripheral wall 33, and to the lower peripheral post mounting flange 40 and the peripheral wall 33.
[0038] Figures 5A and 5B show the two stages of manufacturing the central column 10 of the offshore platform 1 of Figure 2 using a central column bearing 180. The central column bearing 180 includes a spacer tube 181, an upper central column bearing interface 182, and a lower central column bearing interface 185. The upper central column bearing interface 182 includes a tubular section 183 welded to the upper side of the spacer tube 181, and an upper central column bearing mounting flange 184 located at its end side. The lower central column bearing interface 185 includes a tubular section 186 welded to the lower side of the spacer tube 181, and a lower central column bearing mounting flange 187 located at its end side. The central column support 180 includes a top support 190 and a top seat 191 located at its end, an intermediate support 198 with an intermediate seat 199 thereon, and a bottom support 195 with a bottom seat 196 thereon.
[0039] During the manufacture of the central column 10, the upper peripheral wall section 11 and the lower peripheral wall section 13 are welded to the intermediate peripheral wall section 12. For each position of the three outrigger brackets 50, the upper central column mounting flange 22 is aligned with and temporarily installed or screwed to the upper central column bearing mounting flange 184, and the lower central column mounting flange 27 is aligned with and temporarily installed or screwed to the lower intermediate column bearing mounting flange 187. All operations are performed within a tolerance of less than 1 mm. The central column support 180 is positioned and temporarily mounted against the upper peripheral wall section 11 and the lower peripheral wall section 13 by the top seat 191, the intermediate seat 199, and the bottom seat 196. The top seat 191 is coupled to a lug 42 located on the top wall 17, and the intermediate seat 199 and the bottom seat 196 are screwed against the upper peripheral wall section 11 and the lower peripheral wall section 13 with a tolerance of less than 1 mm. The tubular sections 21 and 26 are positioned and their ends are individually welded against the upper central column mounting flange 22 and the upper peripheral wall section 11, and against the lower central column mounting flange 27 and the lower peripheral wall section 11.
[0040] Figure 6A shows the center column bearing 180, which precisely matches the inner external support bearing 140 to form a first mating pair. The upper center column bearing mounting flange 184 is aligned with the upper inner external support bearing mounting flange 144, and the lower center column bearing mounting flange 187 is aligned with the lower inner external support bearing mounting flange 147, wherein the offset of these peripheral adjacent surfaces covers a first offset D1 equal to the length difference between the upper tubular member 51 and the lower tubular member 52 starting from the conically widened intermediate peripheral wall segment 12. The first distance H1 between the centerlines of the upper center column bearing mounting flange 184 and the lower center column bearing mounting flange 187 is equal to the second distance H2 between the centerlines of the upper inner external support bearing mounting flange 144 and the lower inner external support bearing mounting flange 147, all operations being performed with a tolerance of less than 1 mm.
[0041] During the manufacture of the central column bearing 180 and the inner external support bearing 140, the upper central column bearing mounting flange 184 and the upper inner external support bearing mounting flange 144 are aligned with each other and temporarily screwed or installed, and the lower central column bearing mounting flange 187 and the lower inner external support bearing mounting flange 147 are aligned with each other and temporarily screwed or installed. The centerlines are made to be at equal distances of a first distance H1 and a second distance H2, and the mating surfaces are made parallel to each other and at the first offset D1. Thereafter, the equally spaced tubes 141, 181 and the tubular segments 143, 146, 183, 186 are positioned within a tolerance of less than 1 mm, and these components are welded together.
[0042] Figure 6B shows that the peripheral column bearing 160 is precisely matched with the external cantilever support bearing 120 to form a second matching pair. The upper external cantilever support bearing mounting flange 124 is aligned with the upper peripheral column bearing mounting flange 164, and the lower external cantilever support bearing mounting flange 127 is aligned with the lower peripheral column bearing mounting flange 167, wherein the peripheral adjacent surfaces are located in the same vertical plane V. The third distance H3 between the center lines of the upper external cantilever support bearing mounting flange 124 and the lower external cantilever support bearing mounting flange 127 is equal to the fourth distance H4 between the center lines of the upper peripheral column bearing mounting flange 164 and the lower peripheral column bearing mounting flange 167, within a tolerance of less than 1 mm.
[0043] During the manufacture of the peripheral column bearing 160 and the external extension bracket bearing 120, the upper external extension bracket bearing mounting flange 124 and the upper peripheral column bearing mounting flange 164 are aligned with each other and temporarily screwed or installed, and the lower external extension bracket bearing mounting flange 127 and the lower peripheral column bearing bearing mounting flange 167 are aligned with each other and temporarily screwed or installed. The centerlines are positioned at equal third distances H3 and fourth distances H4, and the mating surfaces are located in the same vertical plane V. Subsequently, the spacer tubes 121, 161 and the tubular segments 123, 126, 163, 166 are positioned within a tolerance of less than 1 mm, and these components are welded together.
[0044] According to the present invention, at a first position L1 having a first temperature, the central column bearing 180 and the inner extension bracket bearing 140 are manufactured as a matching first pair as shown in FIG. 6A, wherein all components have previously been subjected to the first temperature. At a second position L2 having a second temperature, the peripheral column bearing 160 and the outer extension bracket bearing 120 are manufactured as a matching second pair as shown in FIG. 6B, wherein all components have previously been subjected to the second temperature. At a third position L3 having a third temperature, the extension brackets 50 are manufactured by the outer extension bracket bearing 120 and the inner extension bracket bearing 140, as shown in FIG. 3A and 3B, wherein the extension brackets 50, the outer extension bracket bearing 120, and the inner extension bracket bearing 140 have all previously been subjected to the third temperature. At a fourth position L4 with a fourth temperature, the peripheral columns 30 are manufactured using the peripheral column bearing 160, wherein each peripheral column 30 and the peripheral column bearing 160 has previously been subjected to the third temperature. At a fifth position L5 with a fifth temperature, the central column 10 is manufactured using the central column bearing 180, wherein both the central column 10 and the central column bearing 180 have previously been subjected to the fifth temperature. At a sixth position L6 with a sixth temperature, the offshore platform 1 is assembled, wherein all components have previously been subjected to the sixth temperature. The third position L3, the fourth position L4, the fifth position L5, and the sixth position L6 may be located away from the first position L1 and the second position L2. The third temperature, the fourth temperature, the fifth temperature, and the sixth temperature may be different from each other and may be different from the first temperature and the second temperature.
[0045] In the third position L3, any thermal expansion or contraction of the steel will have the same dimensional effect on the assembly of the outer cantilever support 120, the inner cantilever support 140, and the cantilever support 50 to be manufactured. In the fourth position L4, any thermal expansion or contraction of the steel will have the same dimensional effect on the assembly of the peripheral column support 160 and the peripheral column 30 to be manufactured. In the fifth position L5, any thermal expansion or contraction of the steel will have the same dimensional effect on the assembly of the central column support 180 and the central column 10 to be manufactured. According to the invention, the supports 120, 140, 160, and 180 are respectively paired at a first position L1 having a first temperature and a second position L2 having a second temperature, thereby ensuring that the cantilever supports 50 are perfectly connected to the central column 10 and the peripheral columns 30 in the sixth position L6.
[0046] In practice, the first location L1 and the second location L2 are located in the same construction site, while the third location L3, the fourth location L4, the fifth location L5, and the sixth location L6 are construction sites in different countries, and at least one of them is more than 100 kilometers away from the others. These construction sites are selected based on production costs and capacity. For example, the sixth location L6 is an assembly site located near the offshore location where the floating wind turbine 5 will be taken to sea and anchored.
[0047] It should be understood that the above description is intended to illustrate the operation of the preferred embodiments and is not intended to limit the scope of the invention. From the above discussion, those skilled in the art will understand that many variations are still included within the scope of the invention. [Simplified Explanation of the Diagram]
[0022] The invention will be illustrated based on an exemplary embodiment shown in the accompanying drawings, wherein: Figure 1 is an isometric view of a floating offshore platform supporting a wind turbine; Figure 2 is an isometric view of only relevant portions of the floating offshore platform, illustrating some steps in manufacturing those relevant portions; Figures 3A and 3B are an isometric view and a top view of two stages of manufacturing the outriggers of the floating offshore platform of Figure 2 using outrigger support seats; Figures 4A and 4B are isometric views of two stages of manufacturing the peripheral columns of the floating offshore platform of Figure 2 using a peripheral column support seat; Figures 5A and 5B are isometric views of two stages of manufacturing the central column of the floating offshore platform of Figure 2 using a central column support seat; and Figures 6A and 6B respectively show the mating pairs of the central column support seat and the matching outrigger support seat, and the mating pairs of the peripheral column support seat and the matching outrigger support seat.
Claims
1. A method for manufacturing a floating offshore platform using a support, wherein the floating offshore platform includes a central column, a plurality of peripheral columns surrounding the central column, and radially extending outriggers connecting the peripheral columns to the central column, wherein the central column includes a central column perimeter wall, and an upper central column mount and a lower central column mount spaced apart from each other and connected to the central column perimeter wall, wherein each of the peripheral columns includes a peripheral column perimeter wall, and an upper peripheral column mount and a lower peripheral column mount spaced apart from each other and connected to the peripheral column perimeter wall, wherein each of the outriggers includes an outrigger structure connected to an upper inner outrigger mount aligned with the upper central column mount, a lower inner outrigger mount aligned with the lower central column mount, an upper outer outrigger mount aligned with the upper peripheral column mount, and a lower outer outrigger mount aligned with the lower peripheral column mount. The bearings include an inner extended support bearing, an outer extended support bearing, a central column bearing, and a peripheral column bearing. The inner extended support bearing includes an inner extended support bearing spacer connected to an upper inner extended support bearing interface and a lower inner extended support bearing interface. The outer extended support bearing includes an outer extended support bearing spacer connected to an upper outer extended support bearing interface and a lower outer extended support bearing interface. The central column bearing includes a central column bearing spacer connected to an upper central column bearing interface and a lower central column bearing interface. The peripheral column bearing includes a peripheral column bearing spacer connected to an upper peripheral column bearing interface and a lower peripheral column bearing interface. The method includes the following steps: At a first temperature and a first position, a first pair is formed using the inner extended support bearing and the central column bearing, wherein the interface of the upper inner extended support bearing is aligned with the interface of the upper central column bearing, and the interface of the lower inner extended support bearing is aligned with the interface of the lower central column bearing. At a second temperature and a second position, a second pair is formed using the outer extended support bearing and the peripheral column bearing, wherein the interface of the upper outer extended support bearing is aligned with the interface of the upper peripheral column bearing, and the interface of the lower outer extended support bearing is aligned with the interface of the lower peripheral column bearing. At a third temperature and at a third position, at least one of the extended supports is manufactured using the inner extended support bearing and the outer extended support bearing, during which the interface of the upper inner extended support bearing is aligned with the upper inner extended support mounting member, and the interface of the lower inner extended support bearing is aligned with the lower inner extended support mounting member, and the interface of the upper outer extended support bearing is aligned with the upper outer extended support mounting member, and the interface of the lower outer extended support bearing is aligned with the lower outer extended support mounting member. At a fourth temperature and at a fourth position, at least one peripheral column is manufactured using the peripheral column bearing, during which the interface of the upper peripheral column bearing is aligned with the upper peripheral column mounting member.The lower peripheral column bearing interface is aligned with the lower peripheral column mounting component. At a fifth temperature and a fifth position, the central column is manufactured using the central column bearing, during which the upper central column bearing interface is aligned with the upper central column mounting component, and the lower central column bearing interface is aligned with the lower central column mounting component. Finally, at a sixth temperature and a sixth position, the floating offshore platform is assembled.
2. The method of claim 1, wherein the bearing interfaces are aligned and adjacent to the mounting components of the floating offshore platform.
3. The method of claim 1, wherein the bearing interfaces are aligned with and installed onto the mounting components of the floating offshore platform.
4. The method of claim 3, wherein the bearing interfaces and the mounting members include mounting flanges that abut against each other and are screwed together.
5. The method of claim 1, wherein the bearing interfaces are aligned with the mounting components of the floating offshore platform with a tolerance of less than 1 mm.
6. The method of claim 1, wherein at least one of the first temperature, second temperature, third temperature, fourth temperature, fifth temperature and sixth temperature is different from the other temperature.
7. The method of claim 1, wherein at least one of the first, second, third, fourth, fifth and sixth positions is more than 100 kilometers away from the other positions.
8. The method of claim 1, wherein the floating offshore platform includes structural members spanning between each adjacent pair of peripheral columns, wherein the method includes the step of installing the structural members after installing the overhanging supports between the central column and the peripheral columns, wherein the structural members are pre-tensioned.