WO2013040871A1

WO2013040871A1 - Pre-stressed concrete floating platform for supporting offshore wind turbine and marine energy generator

Info

Publication number: WO2013040871A1
Application number: PCT/CN2012/071136
Authority: WO
Inventors: 黄灿光; 陈立强
Original assignee: Huang Canguang; Chen Liqiang
Priority date: 2011-09-22
Filing date: 2012-02-14
Publication date: 2013-03-28

Abstract

A semi-submersible floating platform comprises at least three hollow cylinder concrete floating tubes (1). The floating tubes are connected through a transverse frame structure, to form a structure with a plane being a triangle, quadrangle, or a polygon. The floating platform is made of pre-stressed concrete and/or pre-stressed lightweight concrete and/or pre-stressed fiber concrete. On each platform, a horizontal axial wind turbine and/or at least one vertical axial wind turbine (41) is mounted, and optionally, a solar energy (49) and/or wave energy generator is mounted. Also disclosed is a construction and installation method of a pre-stressed concrete floating platform for supporting offshore wind turbine. Compared with the steel floating platform, the concrete floating platform has greatly reduced cost, a low structure gravity center, and higher structure stability. The platform construction and installation method is similar to the mature segmental precast pre-stressed concrete bridge segment assembly construction method. The platform is applied to offshore wind and electricity and ocean green energy source development in which the depth of water is 25 meters or 100 meters or even deeper.

Description

Prestressed concrete floating platform supporting offshore wind turbines and marine energy generators

Cross-reference to related applications

This application claims that the application number is CN. 2011102849315, the application date is September 22, 2011, the priority of the Chinese patent application entitled "suspended prestressed concrete support structure and foundation for offshore wind power and wave power generation". The entire benefit of the above-identified application is hereby incorporated by reference in its entirety herein in its entirety in its entirety in its entirety in its entirety.

Technical field

The invention relates to a concrete semi-submersible floating platform supporting offshore wind power and wave energy and solar power generator, in particular to a floating type made of prestressed concrete or prestressed lightweight concrete or prestressed fiber concrete or the above combination Platforms, and how they are constructed and constructed.

Background technique

The offshore wind turbine support structure and foundation currently used in shallow water areas are mainly pile foundation or gravity foundation. The 30- to 50-meter medium-deep water area uses the truss type jacket (Jacket) foundation. The use of a bottom-fixed foundation in the deep water zone (60 m deep or deeper) is too expensive, so a new type of foundation needs to be found. Based on the semi-submersible concept, the existing technology includes the European Blue H Group (Blue) H Group) Tension Leg Floating Platform (Tensioned Legs) Platform) and the world's No. 1 wind turbine manufacturer Vestas of Denmark and PRINCIPLE POWER INC) Offshore wind power steel floating platform built in Europe in November 2011 WindFloat (triangular steel pontoon). All of these offshore wind power floating platforms are currently made of steel. Each steel floating platform supports approximately 2 megawatts of offshore wind turbines. The application of a 5 MW or greater MW offshore wind turbine will also increase the wind load by several times compared to a 2 MW offshore wind turbine. The wind load at 100 meters above the water surface is quite large at the bottom of the fan tower generated on the surface of the three fan blades of the 5 MW wind turbine. The large size of the fan also means that the quality of the cabin is heavier. When combined with a lighter steel floating platform, the center of gravity of the structure is too high to achieve adequate structural stability. The use of a prestressed concrete floating platform reduces the center of gravity of the entire system and improves stability.

Summary of the invention

The present invention provides a floating platform made of prestressed concrete or prestressed lightweight concrete or prestressed fiber reinforced concrete. The floating platform includes at least three semi-submersible suspended hollow cylinders (hereinafter referred to as pontoons), each of which is connected to each other by a plurality of frame structures, and the pontoons are connected by a lateral frame structure to form a planar triangular or quadrilateral or polygonal structure. Each floating platform is equipped with a horizontal axis fan and / or at least one vertical axis fan and optionally solar and / or wave energy generators. Each floating platform includes at least three pontoons to form a platform structure having a triangular or quadrilateral shape or a polygonal shape as a basic unit, and based on the basic unit, it is also possible to select and construct more complicated interconnected at least three floating platforms for offshore wind power. Field to increase the stability of multi-platform systems against wind and waves. In the symmetrical design, the fan tower is placed at the center of gravity of the floating platform; the asymmetric design, the fan tower is placed at the non-center of gravity of the plane of the floating platform.

The three-float triangular floating platform of the present invention is disposed at a plane of gravity of the floating platform, and supports the fan tower and the fan through the connecting beam or the frame rod.

Another four-floating pontoon combination of the present invention forms a flat-shaped floating platform, and the frame members of the pontoons are connected along the sides of the square. The frame structure is composed of a hollow or solid beam or a combination of the two. . The square floating platform is made more stable by prestressed cables placed on the square diagonal. The size of the pontoon used to support the horizontal axis fan is larger. The remaining three floats support three vertical axis fans.

The third type of five-float square floating platform of the present invention is provided by four satellite buoys at four corner points of a planar square, and the fifth buoy is disposed at the center of gravity of the plane square. The frame structure connects the center buoy with four satellite buoys along a square diagonal. The five-float square floating platform is more stable by connecting four satellite buoys along the four sides of the square by prestressed cables.

In order to reduce the harm caused by the maintenance personnel's movement between the buoys, the top beam of each buoy can use a hollow rod with a larger plane to facilitate the maintenance personnel to walk between the buoys. In order to increase the buoyancy of the platform, hollow bars can also be applied to the bottom beams of the pontoons.

In order to reduce the corrosion of the steel fan tower, in particular to reduce the corrosion of the connection between the wind turbine tower and the pontoon, it is preferable to provide (for example, pouring) a combination of a short reinforced concrete tower and a long steel wind turbine tower, the short concrete tower There is a certain height above the splash zone, for example about 10 meters.

In a preferred aspect of the invention, the platform is further provided with means for sinking the platform in an emergency, for example, when the mooring chain of the platform breaks to allow the platform to float freely on the surface of the water, in order to avoid public Hazard, the device will sink the platform. Conversely, the device is capable of floating the platform. Each pontoon is provided with a waterproof machine room and control room and air chamber. The water pump is installed in the machine room and connected to the inlet and outlet at the lowest point of the air chamber by connecting with the pipe, and communicates with the seawater at the lower part of the pontoon. By controlling the valve, water is forced from the sea into the air chamber and water is forced from the air chamber into the sea. The vent pipe opening is placed at the top of the fan tower and is also opened or closed by controlling the valve. When the vent is opened, the water entering during the sinking operation can vent the air in the air chamber. When half potential is in the sea, the valve will close. It is necessary to move the valve above the water surface before the platform rises, so that air can be pressed into the air chamber to replace the water. If the vent pipe opening is above the water surface after sinking, simply open the valve to allow air to enter the air chamber. The pump's power source comes from the maintenance vessel, which has electrode ports at the mooring buoy, such as at the 1/3, 2/3 height of the tower or at the top of the tower to facilitate service personnel to connect these ports. Since the hollow beam is used to connect the pontoon, the hollow beam is also used as the air chamber, so that the pressed water will surround the floating body, so that even if the pumping operation is performed for one pontoon, the entire platform will not be seriously inclined.

In another alternative application of the invention, the wave energy generator is supported by a tie bar at the top of the floating platform. The floating platform can also be installed with the application number No. A high power variable wing ocean wave energy generator as described in Chinese Patent Application No. 201120134135.1 and No. 201120038156.0. The high-power variable-wing ocean wave energy generator is horizontally arranged to capture wave energy in real time through the generator during up and down movement of the wave.

Yet another alternative application of the invention is that the solar generator is mounted above the wave energy generator and covers the central portion of the platform on the roof of the steel frame.

DRAWINGS

The present invention will be further described below in conjunction with the accompanying drawings and embodiments, in which:

1 is a plan view showing a floating platform of a prestressed (lightweight) concrete three-floating offshore fan according to an embodiment of the present invention;

Figure 2 is a front elevational view of the floating platform of the three-float offshore fan of Figure 1;

Figure 3 is the three-buoy offshore fan floating platform of Figure 1 combined with the application number No. A schematic plan view of a wave energy generator described in Chinese Patent Application No. 201120134135.1 and No. 201120038156.0;

4 is a plan view showing a floating platform of a three-buoy offshore wind turbine according to another embodiment of the present invention;

Figure 5 is a front elevational view of the floating platform of the three-buoy offshore fan of Figure 4 in another embodiment of the present invention;

Figure 6 is a perspective view of the floating platform of the three-buoy offshore fan of Figure 4 in another embodiment of the present invention;

7 is a plan view showing a floating platform of a four-buoy offshore wind turbine according to an embodiment of the present invention;

Figure 8 is a front elevational view of the floating platform of the four-buoy offshore fan of Figure 7;

Figure 9 is a perspective view of the floating platform of the four-float offshore fan of Figure 7;

10 is a plan view showing a floating platform of a four-buoy offshore wind turbine according to another embodiment of the present invention;

Figure 11 is a front elevational view of the floating platform of the four-buoy offshore fan of Figure 10;

Figure 12 is a perspective view of the floating platform of the four-buoy offshore fan of Figure 10;

Figure 13 is a plan view showing a floating platform of a five-float offshore wind turbine according to an embodiment of the present invention;

Figure 14 is a front elevational view of the floating platform of the five-float offshore fan of Figure 13;

Figure 15 is a perspective view of the floating platform of the five buoy offshore fan of Figure 13;

Figure 16 shows the construction method and sequence of the three-floating fan floating platform;

Figure 17 shows the construction method and sequence of the three-floating fan floating platform;

Figure 18 shows the construction method and sequence of the three-floating fan floating platform;

Figure 19 shows the construction method and sequence of the three-floating fan floating platform;

Figure 20 shows the construction method and sequence of the three-floating fan floating platform;

Figure 21 shows a conventional design plane of an application example of a five-float floating platform;

Figure 22 is a cross-sectional view showing the application example of the five-float floating platform of Figure 21 taken along the line 1-1;

Figure 23 is a cross-sectional view showing the application example of the five-float floating platform of Figure 22 taken along the direction 2-2;

Figure 24 is a cross-sectional view showing the application example of the five-buoy floating platform of Figure 22 taken along the 3-3 direction;

Figure 25 is a cross-sectional view showing the application example of the five-float floating platform of Figure 22 taken along the 4-4 direction;

Figure 26 is a cross-sectional view showing the application example of the five-float floating platform of Figure 22 taken along the 5-5 direction;

Figure 27 is a cross-sectional view showing the application example of the five-float floating platform of Figure 22 taken along the 6-6 direction;

Figure 28 shows a particular connection of the center pontoon in the application example setup of the five pontoon floating platform of Figure 21.

Drawing number:

1. pontoon

3. Top beam 4. Diagonal rod

5. Fan tower 6. Mooring anchor chain

7. Seabed 8. Water level

9. Foot beam for fan support 10. Damping plate

11. Fan to pontoon connection 12. Strut to fan connection

13. Prestressed anchor

17. Work platform 18. Open the door to the pontoon

19. Guardrail 20. Concrete tower

21. Wave energy generator 22. Wave energy generator support beam

25. Float reinforcement ring beam 26. Machine and control room

28. Air chamber 30. Buoy prestressed anchor block

31. Center buoy (for direct support of the fan) 32. Conical base of the buoy

33. Conical base of the pontoon

35. Stable cable (top) 36. Stable cable (bottom)

37. Support 38. Prestressed steel cable

41. Vertical axis fan 42. Vertical axis fan

43. Cross baffle 44. Door of the air room

45. Door entrance 46. Partition

47. Internal passage

49. Solar panels 50. Solar panel support

51. Guide piles for building platforms

52. Positioning steel trusses - pillars supported on the guiding piles, and space trusses

53. Floats constructed by segment prefabricated units

54. Damping plate with guide pile opening

55. Sling from space truss to support the pontoon

56. Segmentation of the frame structure

57. Prefabricated assembly frame structure

58. Filling the damper plate opening

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The offshore wind turbine floating platform of the present invention will be described in detail in conjunction with the preferred embodiments. Although the exemplary embodiments have been described in detail, for the sake of clarity, those skilled in the art that the present invention is not critical are not shown. The main material of the floating platform of the present invention refers to prestressed concrete or prestressed lightweight concrete or prestressed fiber concrete or a combination of the three. In addition, the various prestressed concrete materials shown above are used as examples only, and are not intended to limit the invention, as long as other materials capable of implementing the invention (eg, novel composite materials) may be employed without departing from the scope of the invention. Instead of the various prestressed concrete materials listed above. The pontoon in the present invention refers to a hollow cylinder or a hollow polygonal cylinder.

In addition, it should be understood that the prestressed concrete floating platform of the present invention is not limited to the precise embodiments described below, as those skilled in the art can change and improve without departing from the spirit and scope of the protection. For example, elements and/or features depicted in different embodiments may be combined and/or substituted for each other, as long as the hollow cylinder and the hollow polygonal cylinder are interchangeable without departing from the scope of the disclosure.

As shown in FIG. 1 and FIG. 2, the basic three pontoon configuration has three pontoons having a diameter of 8 meters to 10 meters, respectively disposed at the vertices of the triangles, and connected to each other through the frame structure to form a triangular-shaped division structure. The triangular division structure referred to herein refers to a single triangular structure which is a constituent unit of the combined structure, and other structures described below may include two or more triangular division structures. The tower of the horizontal axis fan is erected on a substrate of the platform supported by a frame of beams and rods and located at the center of gravity of the platform. A vertical axis fan is erected on each pontoon as an optional setting. There are two mooring anchor chains on each pontoon that extend to the sea floor for anchoring.

The platform shown in Figure 3 incorporates a wave energy generator. The wave energy generator is No. A wave energy generator described in Chinese Patent Application No. 201120134135.1 and No. 201120038156.0.

As shown in Figure 4-6, in the eccentric plane is a triangular three pontoon, the pontoon 31 supporting the fan tower is larger (diameter 12 to 14 meters), and the other two pontoons are smaller (8 to 10 meters in diameter) ). A concrete frame structure or truss is used to join the buoys to form a triangular structure. It is necessary to provide a shorter reinforcing rod at a quarter of the distance from the pontoon. The three pontoon floating platform can support one horizontal axis fan and two vertical axis fans. Each pontoon is provided with two mooring anchor chains extending from the pontoon to the sea floor for anchoring.

Figures 7-9 show that the triangular structure is a four pontoon setting. It consists of a larger central pontoon (12m to 14m in diameter) and a smaller satellite pontoon (8m to 10m in diameter). Among them, the center buoy is placed at the center of gravity of the platform, and is connected to the satellite buoy by a Y-shaped frame structure with an angle of 120°. In order to complete the triangular division structure, a steel cable is used to connect the satellite buoys. A horizontal axis fan is mounted on the center pontoon and a vertical axis fan is mounted on each satellite pontoon. Each pontoon is provided with two mooring anchor chains extending from the pontoon to the sea floor for anchoring.

As shown in Figure 10-12, the four pontoon structure has four pontoons, respectively disposed at the vertices of the rectangle, and connected by a frame structure to form a rectangular structure with a prestressed cable connection between each pair of diagonal pontoons. . The tower of the horizontal axis fan is erected on one of the pontoons. As an optional setting, at least one of the remaining floats is provided. The pontoons with horizontal axis fans are larger in size (12 to 14 meters in diameter) and the other pontoons are smaller (8 to 10 meters in diameter). Each pontoon is provided with two mooring anchor chains extending from the pontoon to the sea floor for anchoring.

As shown in Figure 13-15, the five pontoon structure has a central pontoon (12m to 14m in diameter) and four satellite pontoons (8m to 10m in diameter) at the center of gravity of the platform. Wherein, four satellite buoys are respectively arranged at the vertices of the rectangle, and are connected to the central buoy along the diagonal of the rectangle through the frame structure. The prestressed cable connects the adjacent two floats along the sides of the rectangle to complete the triangle division. The tower of the horizontal axis fan is erected on the center pontoon. As an optional setting, at least one of the remaining pontoons is provided with a vertical axis fan. The pontoon that supports the horizontal axis fan is larger than the other pontoons to carry heavier horizontal axis fans. Each pontoon is provided with two mooring anchor chains extending from the pontoon to the sea floor for anchoring.

16-20 illustrate a method of constructing a floating platform, which will be described in detail below.

As shown in Fig. 21, taking the embodiment of the five buoy platform as an example, the floating platform is used to support a solar generator installed on the roof structure covering the central area of the platform. Solar panels are mounted on the ceiling. Although the solar panels need to be placed at an optimal angle relative to the sun, the floating platform tends to rotate away from the optimal angle, so it is impractical to fix the solar panels so that they do not tilt. Therefore, the solar panel is horizontally set in this step so that it is independent of the rotation of the platform.

21-28 show a preferred embodiment, which will be described in detail below.

How floating platforms work

In an embodiment of the invention, the working principle of the floating platform is based on the stability of the platform, with a minimum of three structures that are not in the same straight line. The conventional material for making a float is steel. It can be made of prestressed concrete or prestressed lightweight concrete as long as it is properly designed. The hollow cylindrical shell is suspended in water and will be subjected to loads of water pressure and wave pressure. The static pressure at a depth of 10 meters is 100 kN/m2. Equivalent to the load generated by the wheels of heavy trucks. This pressure will produce a large bending moment if loaded onto the plate, but in a hollow cylindrical housing, the hydrostatic pressure mainly causes the circumferential pressure. Concrete performs better in terms of pressure, and steel plates perform poorly in terms of stress. Therefore, for the steel plate, it is necessary to pay attention to the compression buckling instability, and it is necessary to use multiple stiffeners for reinforcement. For a cylindrical shell with a diameter of 12 m, the static pressure is 100 kN/m2. If the wall thickness of the prestressed (lightweight) concrete hollow cylindrical shell is 300 mm, the pressure strength generated on the casing is 4N/mm2. This value is perfectly acceptable for prestressed (lightweight) concrete structures.

Although the prestressed (lightweight) concrete structure is heavy, it will increase the mooring load and size, but the heavier structure will reduce the center of gravity of the entire structure. A lower center of gravity will contribute to the stability of the platform. The base of the platform should be at least 0.7 times the height of the tower, making the platform more stable and limiting bumps (rotation of the tower in the direction of the wind) and turning (rotation of the tower perpendicular to the direction of the wind). A mooring chain attached to the satellite pontoon provides a significant recovery torque to limit off-angle motion (rotational motion about the axis of the tower).

The material damping of prestressed (lightweight) concrete is higher than that of steel, which will help to reduce the vibration of the structure and improve the fatigue resistance of the structural part. The damper plate provided at the bottom of the pontoon and the thickening treatment of the concrete surface will further improve the damping coefficient of the entire structure, thereby contributing to the improvement of the dynamic stability of the platform.

Maintenance and safety measurements

For some cross-sea bridges, the design life of prestressed (lightweight) concrete structures is typically 100 years or more, while the life of offshore wind turbines is approximately 25 years. The basic maintenance cost of the prestressed (lightweight) concrete structure during the life of the first installed fan is almost zero. As the structure with the least maintenance cost, it will also be serviced in the next 25 years of the second wind turbine. As long as a certain level of daily inspection and maintenance is carried out, it can also be serviced during the service life of the third and fourth fans. Routine maintenance is mainly for mechanical and electronic components of offshore wind turbines and floating platforms.

One of the pontoons is provided with a berthing facility with a ladder leading to the top of the pontoon, and maintenance personnel can enter the machine and control room and eventually reach the top of the tower. Safety guardrails and safety rails are provided on the top surface of the beam as safety accessories to facilitate maintenance personnel to walk between the floats or, as an alternative, to enlarge the beams so that their internal space acts as a passage between the floats.

All access doors are waterproof. The machine and control room should have facilities that allow maintenance personnel to stay and communicate for a short period of time during remote maintenance or in inclement weather.

Sensors are installed in the air chamber and in the beam to detect flooding in any direction. Sensors for monitoring structural performance, including the state of concrete integrity, should be installed for structural health monitoring.

Risk assessment

The risks are classified according to the results of the accident. The first level of risk is that the floating platform is disconnected from the mooring chain and drifts away from the original anchor point. The second level of risk is an impact with the ship. The third level of risk is that the blades and towers are damaged in inclement weather. Other risks are the impact on navigation, shipping and fisheries, which can be handled in the usual way. For the first level of risk, two mooring anchor chains are used on each pontoon for redundant setup. The first cable is tighter than the second cable, so the second cable has a larger capacity. Therefore, when the first cable is broken, a second cable having a larger capacity will be put into use. The last way to prevent it from harming the public is to sink the platform to the bottom of the sea. If the depth of the seabed is less than 100 meters, the fan hub is still above the water surface, so that the fan can be recovered for maintenance.

For the second level of risk, enough warnings can be placed around the fan, and the fan should be painted in a bright color to warn the vessel. A similar accident may also be caused by a floating vessel that loses power, so the suspended concrete structure needs to be placed to withstand the impact of the vessel so that it can only cause local damage.

Floating platform installation method:

The invention also provides a prestressed (lightweight) concrete floating platform installation method for a floating wind farm. Suspended offshore wind farms include multiple floating platforms moored in open seas.

The construction began with the casting of these prestressed (lightweight) concrete floating platforms. Casting can be carried out in a conventional manner on land conditions on a dry dock. The method presented here (Figs. 16-20) is not done in the dry dock, but in the dock or port side segment prefabrication method to build the floating platform, so this novel method is called prestressed (lightweight) concrete float Platform section construction "wet method".

The construction of the section "wet method" includes the following steps:

1. A prefabricated portion 53 is prepared in which a segment matching prefabrication is performed between the two planes using a shear key, which is a common method in bridge construction. At the dock/port, the guide pile 51 for controlling the position of the pontoon penetrates into the seabed. These guide piles have mechanisms for supporting the drop-in positioning steel frame to secure the level and position of the float.

2. Transport the pontoon section to the port side and use a pre-stressed epoxy joint. The pontoon 53 constructed by the segment prefabrication unit includes a damper plate 54 provided with a guide pile opening, and the pontoon 53 constructed by the segment prefabrication unit is hoisted to the guide pile 51 by means of a floating crane. As a result, the positioning steel truss 52 (the column supported on the guiding pile 51 and the space truss) is also lowered and fixed on the guiding pile 51.

3. The pontoon 53 constructed by the segment prefabrication unit is then hoisted from the positioning steel truss 52 to a position by the sling 55 and fixed at this position, so that the connection of the prefabricated frame structure 57 portion and the construction of the segment prefabricated unit are constructed. The construction of the pontoon 53 is carried out under dry conditions on the water.

4. At the same time, the frame structure segment 56 is also transported to the port side. A floating crane is used, hoisted and placed in the corresponding connection position of the pontoon 53, and then the pre-stressed and anchored joints are used to connect and fix the joint.

5. Continue operation until all of the frame structure segments 56 are installed, and then build the fan tower foundation support 57.

6. The floating platform is completed. The floating platform is free after the locking device is removed and the positioning steel truss 52 is removed.

7. Fill the opening of the damper plate 54 while the mooring in the sea is ready.

8. After the completed floating platform is free, it can be suspended and dragged to the offshore wind farm installation sea area.

9. Offshore construction installations include mooring anchor chains and mooring systems for towing embedded anchors.

10. Installation of wind turbine towers and offshore wind turbines at sea and optional installation of solar and/or waves

Can generator.

11. Repeat the above steps for the next platform.

Socioeconomic and environmental advantages and economic benefits

The socioeconomic and environmental advantages of embodiments of the present invention are set forth below. Wind farms supported by floating platforms made of pre-stressed (lightweight) concrete can significantly reduce the cost of offshore wind farms, thereby eliminating barriers to implementation. It opens up opportunities to develop wind energy in intermediate water depths and deep waters (water depths of 20 to 100 meters or more). For countries without steel mills, wind energy can be obtained from offshore wind farms, breaking the monopoly of some big countries and further To promote the application of offshore wind farms, the floating platform can also develop marine pastures and wave energy and ocean solar energy, saving energy and reducing emissions and ocean and island economic benefits.

Since it is located in the middle water depth or deep water area, further away from the shore, there will be less negative impact, such as noise. In addition, the platform is semi-submersible and therefore has less impact on fisheries. Moreover, offshore wind farms can be developed as eco-tourism sites.

Applications

The prestressed (lightweight) concrete five pontoon platform has a central pontoon with a center pontometer diameter of 12 m, a height of 21 m, a wall thickness of 0.3 m to 0.4 m, and a top plate of 0.5 m and a bottom plate of 0.4 to 0.75 m. The bottom plate extends beyond the damper plate having a diameter of 18 m.

A 10 m short length concrete tower was cast on the center pontoon. A leg is provided at the top for anchoring the steel tower foundation to which the anchor is pre-installed. A safety work platform is placed on top of the concrete tower. For a 5 MW fan, it weighs more than 200 tons and the rotor has a diameter of 120 meters, at which point the tower has a height of 90 meters. Together with the steel tower, the total weight of the fan will be between 700 and 1000 tons.

The four satellite buoys are 8 meters in diameter and 23 meters in height, respectively placed at the apex of the rectangle of 70.7x70.7m, ie the diagonal length is 100 meters. The wall thickness of the pontoon is 0.3 to 0.4 meters at the bottom. The top plate has a thickness of 0.3 m to 0.5 m and the bottom plate is 0.3 m to 0.6 m. The bottom plate extends outward to form a damper plate having a diameter of 18 meters.

The diagonal length between the center buoy and the satellite buoy is 50 meters. A pre-stressed (lightweight) concrete frame is used to connect each of the two floats. The top and bottom beams are 3mx3m hollow components, allowing maintenance personnel to move within the hollow area of the top beam and the hollow section of the bottom beam to accommodate air to provide additional buoyancy.

Figure 21 shows a top plan view of the five pontoon settings. The platform comprises a central pontoon 31 having a diameter of 12 meters and a height of 21 meters and four satellite pontoons 1 having a diameter of 8 meters and a height of 23 meters. The solar panel 49 is mounted on the top panel and is supported by beams (3, 22).

Figure 22 shows a schematic cross-sectional view of the platform. The pontoon includes two waterproof portions: a machine and control room 26 and an air chamber 28. The beam 3 is a 3 m by 3 m hollow structure, and the diagonal bar 4 is H-shaped. The beam 3 serves as an internal passage 47 between the floats. The sill 2 is used as part of the air chamber 28 to increase buoyancy. A short concrete tower 20 is cast onto the pontoon to raise the height of the steel tower 5 away from the splash zone.

FIG. 23 shows that four impellers 21 are supported on the top beam 3 and the sub-frame 22. The prestressed cable 35 further stabilizes the platform by triangular division. The blade turbine 21 is No. in the application number. It is described in Chinese Patent Application No. 201120134135.1 and No. 201120038156.0.

Figure 24 shows a portion through the top beam 3, specifically showing the central pontoon 31 and the transverse partition 43 in the satellite pontoon 1 and the partition 46 at the concrete truss node. The partition has an opening in the center 45 for internal access.

Fig. 25 shows the connection details of the center inner pontoon 31. The sill 2 is connected to the pontoon by a prestressed cable 38 and by an anchor 13 that passes through the pontoon prestressed anchor block 30. The walls of the pontoon are reinforced by a reinforced ring beam 25 having a depth of 2.0 meters.

Figure 26 shows the connection details of the pontoon inside the satellite. The joining is accomplished by combining the concrete anchor block 30, the prestressed cable 38, the anchor 13 and the reinforcing ring beam 25.

Figure 27 shows a schematic cross-sectional view of a concrete truss.

Figure 28 shows the connection of the beam (2, 3) to the central pontoon using a prestressing method. The prestressed cable 38 is installed in the beam and pulled from the inside of the pontoon, and the anchoring tension of each beam end is balanced by the reinforcing ring beam 25 and the plate 43. The top beam 3 serves as an internal passage 47 in which a manhole is placed and a hatch 45 is provided. The sill 2 serves as part of the air chamber 28 and has an open passage 44 in the pontoon wall. The short concrete tower 20 is about 10 meters and is poured on top of the pontoon. The steel tower is anchored to the concrete short tower by the anchor 11, and the working platform 17 and the guardrail 19 are provided. The damper plate 10 has a diameter of about 18 meters and can be installed as a stiffener of the beam at the bottom of the pontoon or at the bottom beam. The mooring anchor chain 6 is attached to the pontoon. The solar panel 49 is mounted on a top panel that is supported by the sub-frame 50 on the top rail.

Claims

A semi-submersible floating platform, characterized by comprising:

a plurality of vertically arranged semi-submersible floating buoys (1), the buoys (1) being hollow cylinders, and the buoys being connected to each other and disposed in water;

a plurality of frame structures for connecting the buoys to form a plane having a triangular or quadrilateral or polygonal structure;

a plurality of steel cables (38) for connecting the buoys;

a plurality of mooring anchor chains (6) and anchors (13) connected to the floating platform, disposed in the water to limit the position of the floating platform; wherein

Each of the floating platforms includes at least three pontoons (1) and a plurality of frames for connecting the pontoons (1);

The steel cable (38) is configured to connect the pontoon (1) to form a stable structure having a triangular division.
The floating platform according to claim 1, wherein the floating platform is supported with a horizontal axis fan that generates electricity under the action of wind.
The floating platform according to claim 1, wherein the floating platform is supported with a vertical axis fan (41) that generates electricity under the action of wind.
The floating platform according to claim 1, wherein the floating platform is supported by a wave energy generator.
The floating platform according to claim 1, characterized in that a solar generator (49) is connected to the floating platform.
The floating platform according to claim 1, wherein the frame structure of the joining pontoon comprises a top beam (3) and a bottom beam (2), a vertical short rod or a diagonal rod or a combination of both.
A floating platform according to claim 1, characterized in that the pontoon (1) and/or the frame structure are made of prestressed concrete.
A floating platform according to claim 1, characterized in that the pontoon (1) and/or the frame structure are made of prestressed lightweight concrete.
The floating platform according to claim 1, characterized in that the pontoon (1) and/or the frame structure are made of prestressed fiber concrete.
The floating platform according to claim 1, characterized in that the pontoon (1) and/or the frame structure are made of prestressed steel tube concrete.
A floating platform according to claim 1, characterized in that the pontoon (1) and/or the frame structure are made of a steel-concrete composite material.
A floating platform according to claim 6 wherein at least a portion of the bars of the frame structure are constructed of reinforced concrete and/or reinforced lightweight concrete.
A floating platform according to claim 1 wherein the vertical surface of the floating platform in contact with water is thickened to increase the friction between the surface and the water.
The floating platform according to claim 1, characterized in that the bottom of the pontoon (1) is provided with a damper plate (10) for increasing the damping coefficient of the platform and reducing the sway caused by the waves.
The floating platform according to claim 1, characterized in that each of said buoys (1) comprises a waterproof machine and control room (26) and an air chamber (28); wherein each float (1) is provided with a water pump For pressing water into the air chamber (28) to sink the platform, or to press water from the air chamber (28) to raise the platform; the buoy (1) is also provided with The snorkel is pumped to the top of the fan to allow air to enter and exit the air chamber (28), thereby enabling sinking or ascending the platform by controlling pumping operation.
The floating platform according to claim 15, wherein said air chamber (28) is filled with a lightweight packaging material and air for providing buoyancy, said lightweight packaging material comprising polyurethane and foam blocks for permanent suspension The platform.
A floating platform according to claim 6, wherein said top beam is of a hollow structure to enable maintenance personnel to use it as a passage between the pontoons (1).
The floating platform according to claim 6, wherein the top beam and/or the bottom beam are filled with a lightweight encapsulating material and air for providing buoyancy, and the lightweight packaging material comprises a polyurethane and a foam block for Suspend the platform permanently.
The floating platform according to claim 1, characterized in that the wind turbine tower (5) is supported on a central pontoon (31); wherein the central pontoon (31) is located at the center of gravity of the platform and passes through the frame The structure is connected to other floats, which are satellite floats.
The floating platform according to claim 1, wherein the fan tower (5) is supported on a connecting rod member; wherein the connecting rod member is located at a center of gravity of the platform and passes through a frame structure The buoys (1) are connected.
The floating platform according to claim 1, wherein said fan tower (5) is supported on one of said floats of said floating platform, said float being larger in size and passing through the size of the other floats The frame structure is connected to other floats.
A construction and installation method for a prestressed concrete floating platform supporting an offshore wind turbine, characterized in that it comprises:

Using a segment prefabrication method in the prefabrication yard or factory to match the pontoon segments (53) that make up the pontoon (1);

Dividing the frame structure connecting the platform to each buoy (1) into a frame structure segment (56);

Using the segment prefabrication method in the prefabrication field or the factory to match the casting of the frame structure segment, using the prestressed frame by frame segment to assemble the frame structure segment, and completing the entire prefabricated assembly frame structure (57);

The guide piles (51) are inserted at the sea side of the port side, and each of the pontoons (1) is provided with at least three guide piles (51), so that the steel truss (52) can be positioned to support the pontoon on the sea side of the port side (1) )installation;

Transporting the prefabricated buoy segment (53) to the port side;

Prestressing the pontoon segments (53) to complete the prefabrication of the entire pontoon;

Lifting the completed prefabricated assembly float to the position of the guide pile (51) by a floating crane, and lowering the positioning steel truss (52) to be fixed on the guide pile (51);

Adjusting the level and position of the buoy (1) and fixing with the positioning steel truss;

Transporting the entire prefabricated frame structure (57) to the port side;

Using a floating crane, the entire prefabricated assembled frame structure (57) is lowered to a joint position corresponding to each of the buoys (1), and the joint is connected and fixed by prestressing and anchoring;

Repeat the above steps to complete the segment construction method of the floating platform;

Removing the locking device and removing the positioning steel truss (52);

After the floating platform is free, it can be suspended and floated to the sea area where the offshore wind farm is installed;

Installation of mooring systems including mooring anchor chains and towed embedded anchors at sea;

Install wind turbine towers and offshore wind turbines at sea.
The construction and installation method of a prestressed concrete floating platform for supporting an offshore wind turbine according to claim 22, wherein the construction and installation method further comprises:

Install solar and/or wave energy generators at sea.