CN204415681U - Semi-submersible lng floating blower foundation and floating blower fan - Google Patents

Abstract

The utility model provides a semi-submersible floating fan foundation and a floating fan, comprising: at least three uprights; a upright connection structure connected to the lower end of each upright respectively so that the uprights and the upright connection structure are integrated; supporting uprights, Set in the center of the foundation of the floating wind turbine, it is used to support the tower, nacelle, blades and wind turbines of the wind turbine, wherein the cross-sectional area of each column increases upward at a predetermined position below the water surface. The floating wind turbine includes: the foundation of the semi-submersible floating wind turbine; the tower installed on the support column of the foundation of the semi-submersible floating wind turbine; the nacelle installed on the top of the tower; the wind turbine and the blades installed in the nacelle Front end. By applying the above-mentioned semi-submersible floating fan foundation, the structure and motion performance of the floating fan are improved, and the production cost and installation cost are reduced.

Description

Semi-submersible floating wind turbine foundation and floating wind turbine

technical field

The utility model relates to the field of offshore wind power generators, in particular to a semi-submersible floating fan foundation with improved structure and a floating fan with the semi-submersible floating fan foundation.

Background technique

In the deep sea area above 50 meters, there are more and better wind resources that can be developed and utilized, and the market prospect is also broader. To develop deep-sea wind farms in these sea areas, it will not be advantageous to fix the various through-pile structures on the seabed that are commonly used in offshore wind farms, because: as the water depth increases, the cost of fixed foundations rises linearly; fixed offshore wind turbines The cost of construction and operation and maintenance is higher than that of floating type. Therefore, in order to enable the construction of offshore wind farms to develop into deep sea areas, it is necessary to develop economical and practical floating wind turbines. Therefore, how to develop a floating fan base with excellent motion characteristics, compact structure, economical and practical has become the most critical issue in the development of floating fans.

The loads borne by the floating wind turbine foundation applied in the field of offshore wind power are different from the mobile platforms in traditional offshore oil engineering, because the floating offshore wind turbine foundation not only bears the joint action of wind, wave and current, but also bears the towering structure of the wind turbine. The resulting gyroscopic effect, the overturning moment Mx, My and the torque Mz around the vertical axis, the whole fan will produce six degrees of freedom of violent motion, including the axial movement of the X, Y and Z axes and the swing around the axis, which It brings great challenges to the pitch and yaw control system of the wind turbine, which will affect the normal operation of the wind turbine, affect the power generation, and even endanger the safety of the entire system structure.

Therefore, it is necessary to develop a floating wind turbine foundation that can keep the wind turbine running smoothly.

Utility model content

The purpose of the utility model is to provide a semi-submersible floating fan foundation with improved structure and a floating fan with the semi-submersible floating fan foundation.

Another object of the utility model is to provide a semi-submersible floating fan foundation with improved motion performance and a floating fan with the semi-submersible floating fan foundation.

Another object of the present utility model is to provide a semi-submersible floating fan foundation with reduced production and installation costs and a floating fan with the semi-submersible floating fan foundation.

In order to achieve the above purpose, a semi-submersible floating fan foundation is provided, including: at least three columns; a column connecting structure, which is connected to the lower end of each column, so that the column and the column connecting structure are integrated; supporting columns, set In the center of the foundation of the floating wind turbine, the tower, nacelle, blades and wind turbines are used to support the wind turbine, wherein the cross-sectional area of each column becomes larger upward at a predetermined position below the water surface.

The cross-sectional area of the column may change abruptly at the predetermined position.

The cross-sectional area of the column may gradually increase upward from the predetermined position.

The uprights may have the same cross section below the predetermined position.

The bottom end of the column can be provided with a heave plate.

The outer side surface of the column may be inclined towards the outer side of the floating fan foundation with respect to the vertical direction.

The outer side of the column may be inclined outwardly by 5 degrees to 10 degrees relative to the vertical direction.

The inner side surfaces of the posts may remain vertical.

Each column and the supporting column can be connected to each other through straight struts and diagonal struts.

The column connection structure may be a bottom pontoon or a truss structure.

A ballast water regulating system may be provided at the bottom of the column and in the bottom buoyancy tank.

A plurality of rectification holes can be formed on the heave plate.

The heave plate can be connected with the column through the inclined connecting rod.

The floating wind turbine foundation may be anchored to the seabed by catenary mooring cables.

The floating wind turbine foundation can be anchored to the seabed by catenary mooring cables, wherein the upper ends of the mooring cables can be connected to the heave plates.

The bottom pontoon may have a Y-shape.

According to another aspect of the present utility model, a floating fan is provided, including: the foundation of the semi-submersible floating fan as described above; a tower mounted on the support column of the foundation of the semi-submersible floating fan; At the top of the tower; wind turbines and blades, mounted at the front end of the nacelle.

The utility model can not only reduce the weight by at least 20% compared with the traditional semi-submersible platform structure by using the column with variable cross-section, but also realize the wet towing installation of the whole floating fan, avoiding the use of expensive large-scale sea transport ships and installation ships.

When the variable cross-section semi-submersible floating fan foundation proposed by the utility model is used in medium-depth sea areas, the comprehensive indicators of motion performance, economy, installation, operation and maintenance are better than jacket foundations. For example, for 6MW fans, the amount of steel used by the foundation is comparable to that of conduits. The base of the rack is lowered by about 15%.

The installation of the heave plate at the bottom of the column proposed by the utility model can provide greater additional damping and additional mass, reduce the base movement range, meet the power generation requirements of the normal operation of the fan, and increase the power generation; moreover, in the comprehensively adopted variable In the case of cross-sectional columns and heave plates, compared with traditional semi-submersible platforms, the overall structural cost can be reduced by about 30%.

According to the utility model, the base of the semi-submersible floating fan is easy to process and manufacture. It can be built in a general dock or on the berth, and the whole machine can be assembled at the shore wharf. The large-scale floating crane required for conventional offshore hoisting brings convenience to the installation of offshore wind turbines and greatly saves transportation and installation costs.

For the floating fan based on the semi-submersible floating fan according to the utility model, when a large part needs to be replaced or when a typhoon strikes, the cable can be uncabled, and only an ordinary tugboat can be towed back to the port as a whole for part replacement or It is sheltered from the wind, has good maneuverability, saves the high cost of large floating cranes and transport ships, and avoids the harm caused by typhoons to the unit.

Description of drawings

Through the following description in conjunction with the accompanying drawings, the above-mentioned and other purposes and characteristics of the present utility model will become more clear, wherein:

Fig. 1 is a perspective view of a floating fan applied with a semi-submersible floating fan foundation according to an embodiment of the present invention;

2 is a perspective view of a semi-submersible floating wind turbine foundation and its mooring system according to an embodiment of the present invention;

Fig. 3 is a perspective view of a semi-submersible floating wind turbine foundation according to an embodiment of the present invention.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1 , a floating wind turbine or a floating wind turbine 100 according to an embodiment of the present invention includes a floating wind turbine foundation 10 , mooring cables 20 , a tower 30 , a nacelle 40 , a wind turbine 50 and blades 60 . In the embodiment according to the present utility model, the floating wind turbine foundation 10 is a semi-submersible floating wind turbine foundation. The main body of the wind turbine is supported, that is, the tower 30, the nacelle 40, the wind turbine 50, the blades 60, and the like. Since the floating wind turbine foundation 10 is able to move with sea waves, it is anchored to the seabed by mooring cables 20 . Preferably, the mooring line 20 is a catenary mooring line.

As shown in FIGS. 1 to 3 , a support column 11 is provided at the center of the floating wind turbine foundation 10 , and the support column 11 is connected to the tower 30 to support the nacelle 40 , the wind turbine 50 and the blades 60 mounted on the top of the tower 30 . As shown in FIG. 1 , the fan has three blades 60 , and the rotor of the generator set 50 interacts with the stator through the rotation of the blades 60 , so as to convert wind energy into electrical energy. In accompanying drawing 1, although it is shown that the fan has three blades, the present invention is not limited to three, and the fan may also have 2 or more blades.

The specific structure of the semi-submersible floating wind turbine foundation 10 according to the embodiment of the present invention will be described in detail below with reference to the accompanying drawings 2-3.

As shown in FIGS. 2 to 3 , the floating wind turbine foundation 10 includes three uprights 12 and a bottom buoyancy tank 13 connecting the uprights 12 . The bottom buoyancy tank 13 has a Y-shape, that is, the three protruding ends of the bottom buoyancy tank 13 are respectively connected with the lower end of each column 12, so that the upright column 12 and the bottom buoyancy tank 13 form an integrated structure. In the center of the bottom buoyancy tank 13 (that is, the center of the entire floating fan foundation 10 ) is provided with a support column 11 for supporting the main body of the fan. The support column 11 has a cylindrical shape, and its top end is connected to the bottom end of the tower frame 30 through a flange. In addition to supporting the tower 30 and the main body of the wind turbine (namely, the nacelle 40, the generator set 50 and the blades 60), the support column 11 can also place electrical cabinets inside it, increasing the layout space. The cross-sectional shape of the support column 11 is not limited to a circle, and a square shape may also be adopted.

The floating wind turbine foundation 10 also includes a plurality of struts connecting the uprights 12 and supporting the uprights 11 . The plurality of struts include straight struts 14 and diagonal struts 15 . As shown in Fig. 2 and Fig. 3, between each column 12 and support column 11, connect by a straight strut 14 and a diagonal brace 15, wherein, straight strut 14 is connected with the upper end of column 12 and support column 11 between the upper ends of the upper ends, and the diagonal struts 15 are obliquely connected between the upper end of the support column 11 and the lower end of the column 11, so as to strengthen the connection structure of the column 11, the support column 14 and the bottom pontoon tank 13.

Although the bottom pontoon tank 13 is shown as the column connection structure in the embodiment, the utility model is not limited thereto, and a truss structure may also be used instead of the bottom pontoon tank. However, relatively speaking, adopting the bottom buoyancy box as the column connection structure has the following advantages in addition to the structural effect: since the Y-shaped bottom buoyancy box 13 is located at a depth below the water surface in the working state, the wave action is greatly reduced. force. In addition, in the embodiment according to the present utility model, each protruding end of the Y-shaped bottom pontoon tank 13 has a rectangular longitudinal section, which effectively increases the heaving, rolling, pitching and yaw of the entire floating foundation 10. Additional damping and additional mass, so as to achieve the purpose of reducing the range of motion of the entire floating fan. When assembling on the shore, the bottom buoyancy tank 13 provides buoyancy to support the whole floating wind turbine, so that the draft of the foundation is relatively shallow and meets the requirements of shallow draft in the port; under the design draft, the bottom buoyancy tank 13 is filled with ballast water, which reduces the The center of gravity of the entire foundation improves stability and seakeeping.

In order to reduce the destructive effect caused by the impact of waves on the floating foundation 10, the cross section of the column 12 and the longitudinal section of the bottom pontoon 13 preferably have rounded corners.

The floating fan foundation 10 may also include a heave plate 16 installed at the bottom of each column 12 and connected to the lower end of the column 12 through an inclined connecting rod 17 . Each heave plate 16 may have a circular shape.

A plurality of rectification holes are formed on the heave plate 16 . The porosity of the heave plate can be determined by computational fluid analysis software or model tests. The structural size of the heave plate 16 and the inclined connecting rod 17 can be determined according to the meteorological and hydrological conditions of the target sea area, combined with the actual operating conditions of the wind turbine, and the dynamic analysis of the whole machine is carried out to obtain the load for structural strength analysis to determine the size. The main function of the heave plate 10 is to increase the additional damping and additional mass of the heave/pitch, thereby reducing the motion range of the floating foundation 10, and the rectification holes on it effectively improve the fluid flow conditions near the heave plate, further Added additional damping.

However, the present invention is not limited thereto, and the shape of the heave plate 16 is not limited to a circle, and a polygonal shape can also be used, and rectifying holes are selectively provided according to needs.

Where there is a heave plate 16, mooring cables 20 may be connected to the heave plate 16 to anchor the entire wind turbine. The mooring lines 16 may be formed using various suitable materials, such as steel pipes, polyurethane, steel cables, anchor chains, combinations of these materials, and the like. If no heave plate 16 is provided, the mooring lines 20 may be connected to the outer edge of the lower end of the upright 12 . Preferably, each column can be connected with two mooring cables 20 to keep the whole floating wind turbine anchored stably.

As shown in FIGS. 1 to 3 , the column 12 is a square column with variable cross-section. The specific structure of the column 12 will be described in detail below.

According to an embodiment of the present invention, the cross-sectional area of the column 12 increases upward from a predetermined position at the lower part thereof. That is to say, the cross-sectional area of the portion of the column 12 above the predetermined position is greater than the cross-sectional area of the portion of the column 12 below the predetermined position. As shown in FIGS. 2 and 3 , the cross-sectional area of the column 12 according to the embodiment of the present invention gradually increases upward from the predetermined position, while the cross-sectional area of the portion of the column 12 below the predetermined position remains unchanged. Since the floating foundation of the present invention is a semi-submersible floating foundation, the lower part of the column 12 will be submerged in the water in the working state. The predetermined position is set at a certain position below the water surface in the lower part of the column 12 . In this way, the column 12 with variable cross-section can increase the stability and seakeeping performance of the floating foundation in a free-floating state.

Preferably, the predetermined position may be at a depth of about 10 meters underwater.

Preferably, the inner side of the column 12 (specifically, the side of the column 12 facing the central support column 11 is the inner side) is kept vertical, and the outer side is inclined 5-20° from a predetermined position under water to form a uniform transition of a conical surface To the top of the upright column 12, preferably, the outer side is inclined 5-10° from a predetermined position under water. Due to the outward inclination of the column 12, the larger the horizontal/pitch angle of the floating fan foundation 10 is, the larger the area of the waterline surface is, the larger the distance from the center of the area to the rotation axis is, and the larger the area moment is, the greater the restoring force provided. big. At the same time, the section size of the part below the water surface is small, and the size of the bottom buoyancy tank 13 connected thereto will also be reduced, which effectively reduces the structure size and weight, improves the structure utilization rate, and reduces the manufacturing cost.

The variable cross-section square column 12, the central circular support column 11 and the bottom floating tank 13 are connected by struts 14 and 15. On the one hand, it ensures that the upper fan load is reasonably distributed and transmitted to the floating foundation 10. On the other hand, it ensures that the entire floating The overall strength of the underlying structure.

The entire floating foundation 10 can be designed with a draft of about 10-20m, and a ballast water adjustment system is installed at the bottom of each column 12 and inside the bottom buoyancy tank 13 to adjust the draft of the towed and in-position working conditions, so as to realize the overall towed sail. The entire foundation has obvious structural cost and installation and operation cost advantages, and has excellent motion performance, which meets the motion requirements of the wind turbine under normal power generation conditions. Under extreme sea conditions that occur once in 50 years, the motion range does not exceed 5°, and the horizontal displacement does not exceed the water depth. 10% of.

In the absence of the bottom buoyancy tank 13, the ballast water regulating system can only be provided at the bottom of the column 12. Ballast water conditioning systems can use seawater, sand or a combination of these for ballasting.

In the above embodiments, all components are connected together by welding, and the middle circular support column 11 is connected to the upper tower 30, which needs to be reasonably strengthened in accordance with the operating conditions of the wind turbine and the analysis of the structural strength under extreme sea conditions. The interior of the variable cross-section column 12 and the bottom buoyancy tank 13 needs to be reasonably strengthened to withstand hydrostatic pressure and wave pressure loads. Under the premise of frequency, fan 1P and 3P frequency range, the basic hydrodynamic performance can be optimized through aerodynamic-hydraulic-control-structure dynamic analysis software, hydrodynamic software or model test to obtain the optimal structural size.

Although not shown, guardrails can also be provided on the top of the variable-section column 12, and equipment such as windlasses can be arranged. At the same time, it is convenient for maintenance. The channel of the middle support column 11 enters the fan for maintenance.

In the above embodiment, the increase of the cross-sectional area is achieved by the outside of the column 12 being inclined outward from the predetermined position, but the utility model is not limited thereto, for example, the column 12 may also have a cross-sectional area at the predetermined position change in area. By changing the cross-sectional area of the column 12 at a predetermined position, a stepped structure can be formed at this position, which is similar to installing a heave plate at a predetermined position of the column 12, thereby increasing the heave/pitch of the floating fan Additional damping and additional mass.

On this basis, the cross-sectional area of the part of the column 12 above the predetermined position can gradually increase or remain unchanged. Not only that, it is also possible to sequentially form two or more stepped structures at the lower part of the column 12, or additionally set up a multi-layer heave plate, which can increase the heave/pitch additional damping and additional mass of the floating fan , thereby improving the stability of the floating fan.

The way to increase the cross-sectional area of the column 12 is not limited to this, for example, the inner side (or inner side wall) and the outer side (or outer side wall) of the column 12 can be inclined inwardly and outwardly with respect to the vertical direction respectively, or the column 12 All of the side walls of the column slope outwardly with respect to the vertical passing through the center of the column.

In the embodiment of the present utility model, the variable section column of the present utility model is described by taking three variable section square columns 12 with rounded corners as an example, however, the utility model is not limited thereto, for example, the number of columns can be 4 or more; the cross-sectional shape of the column 11 is not limited to a roughly rectangular shape, for example, it can also be various suitable shapes such as a circle, an ellipse, a roughly square or a combination of the above shapes. Similarly, the shape of the bottom pontoon tank 13 is not limited thereto. For example, when there are 4 columns, the bottom pontoon tank 13 or the truss structure can be formed in a circular shape, and when there are 5 or more columns, the bottom pontoon tank or the truss structure can be formed in a radial pattern. The four pillars 13 can be respectively arranged at the corners of the bottom pontoon or truss structure; the longitudinal cross-sectional shapes of the respective extensions or connecting parts of the bottom pontoon 13 are not limited to roughly rectangular, and circular, elliptical, square, etc. can also be used. Various suitable shapes.

The structure of the semi-submersible floating fan foundation using the variable cross-section column and the floating fan with the floating fan foundation has been described above. According to the utility model, the variable cross-section semi-submersible floating foundation can adopt an all-steel structure. For wind power generators with different capacities, you can choose a port near the shore for assembly during construction, and then wet drag the whole to the installation site, and then Positioned by mooring without routine maintenance requirements.

It is clear from the above description that the semi-submersible floating wind turbine foundation according to the embodiment of the present invention has at least the following advantages:

(1) Because the utility model adopts the column with variable cross-section, the cross-sectional area of the water part is large, and it has a large waterline surface area moment, and the static stability and seakeeping performance are excellent during towage, avoiding the use of expensive large-scale offshore installation ships , which reduces the installation cost; not only that, the application of the variable cross-section column helps to effectively reduce the amount of steel used in the underwater part of the structure, improves the utilization rate of the structure, reduces the amount of steel used, and reduces the structural cost.

(2) Since the heave plate is arranged at the bottom of the column, the additional damping and additional mass are effectively increased, and the heave period is adjusted to avoid the period range of wave energy concentration (usually 3-20s), and the heave motion is reduced by at least 20%. ; At the same time, the additional mass and damping of the pan/pitch are increased, so that the entire foundation motion performance is better, and the swing angle is reduced by at least 15%. Since the overall pan/pitch and heave motion period of the floating fan is below 3s, avoid It avoids the 3-20s cycle range where the wave energy is concentrated, avoids the first-order frequency of the tower, and also avoids the 1P and 3P frequency ranges of the fan, effectively reducing the resonance response of the entire floating fan system and reducing the overall The limit load and fatigue load level of the machine ensure the safe and reliable operation of the fan; through the combination technology of the variable cross-section column and the heave plate, the lateral/pitch motion range of the entire floating fan system can be significantly reduced, reducing the incoming flow and The included angle of the impeller increases the power generation of the fan below the rated wind speed; in the case of comprehensively adopting the variable cross-section column and the heave plate, compared with the traditional semi-submersible platform, the overall structural cost can be reduced by about 30%;

(3) The variable cross-section semi-submersible floating fan foundation of the utility model has excellent motion performance, and is especially suitable for sea areas with a water depth of more than 30m. Convenience, good recyclability, installation and dismantling have little impact on the environment.

(4) The mooring system of the present invention can use polyurethane cables or steel cables, which reduces mooring costs and construction difficulties.

(5) The utility model has obvious installation and construction advantages: when assembling the whole machine at the port port on the shore, by adjusting the ballast water in the three columns and the bottom floating tank, the draft of the foundation can meet the assembly requirements of the entire floating structure, At this time, the draft is relatively shallow (not more than 8 meters). After the assembly is completed, adjust the ballast water to a certain draft, wet drag the whole machine to the installation site, and open the valve connected to the inside of the bottom floating tank to fill in the ballast water, and then Connect the mooring cables, and then discharge the ballast water through the load adjustment system until the design draft. The whole operation is simple and convenient, and the cost is low; Stability requirements under various working conditions, such as towage and in-position working conditions, make it possible to facilitate offshore construction operations under various working conditions; the variable cross-section semi-submersible floating foundation in the utility model can also be used in docks or slipways It can be built on the ground without complicated high-altitude operations, and the assembly of the entire floating wind turbine can be completed by a land crane at the shore wharf, and then towed (wet towed) as a whole to the installation site and positioned by mooring. Therefore, the utility model has the characteristics of simple structure, convenient processing, low cost, and easy realization. As an important marine engineering equipment for developing deep-sea wind farms, the utility model is used to support the safe operation of large-capacity wind turbines above 5MW.

The present invention is not limited to the above-mentioned embodiments, and various variations and modifications can be made without departing from the scope of the present invention.

Claims (17)

1. A semi-submersible floating wind turbine foundation, comprising: At least three uprights; The column connection structure is respectively connected with the lower end of each column, so that the column and the column connection structure are integrated; The support column, set in the center of the foundation of the floating wind turbine, is used to support the tower, nacelle, blades and wind turbines of the wind turbine, It is characterized in that the cross-sectional area of each column increases upward at a predetermined position below the water surface. 2. The semi-submersible floating wind turbine foundation according to claim 1, wherein the cross-sectional area of the column changes abruptly at the predetermined position. 3. The semi-submersible floating wind turbine foundation according to claim 1 or 2, wherein the cross-sectional area of the column gradually increases upward from the predetermined position. 4. The semi-submersible floating wind turbine foundation according to claim 1, wherein the parts of the columns below the predetermined position have the same cross section. 5. The semi-submersible floating fan foundation according to claim 1, wherein a heave plate is arranged at the bottom of the column. 6. The semi-submersible floating fan foundation according to claim 3, wherein the outer surface of the column is inclined to the outside of the floating fan foundation relative to the vertical direction. 7 . The semi-submersible floating wind turbine foundation according to claim 6 , wherein the outer side of the column is inclined 5° to 10° outward relative to the vertical direction. 8. The semi-submersible floating wind turbine foundation according to claim 6, wherein the inner surface of the column remains vertical. 9. The semi-submersible floating wind turbine foundation according to claim 1, characterized in that, each column and the support column are connected to each other through straight braces and diagonal braces. 10. The semi-submersible floating wind turbine foundation according to claim 1, wherein the column connection structure is a bottom buoy box or a truss structure. 11. The semi-submersible floating wind turbine foundation according to claim 10, characterized in that a ballast water adjustment system is provided at the bottom of the column and in the bottom buoyancy tank. 12. The semi-submersible floating wind turbine foundation according to claim 5, wherein a plurality of rectification holes are formed on the heave plate. 13. The semi-submersible floating wind turbine foundation according to claim 5, wherein the heave plate is connected to the column through an inclined connecting rod. 14. The semi-submersible floating wind turbine foundation according to claim 1, wherein the floating wind turbine foundation is anchored to the seabed through catenary mooring cables. 15. The semi-submersible floating wind turbine foundation according to claim 5, wherein the floating wind turbine foundation is anchored to the seabed by a catenary mooring cable, wherein the upper end of the mooring cable is connected to the heave plate . 16. The semi-submersible floating wind turbine foundation of claim 10, wherein the bottom buoyancy tank has a Y-shape. 17. A floating fan, characterized in that it comprises: The semi-submersible floating fan foundation according to any one of claims 1 to 16; The tower is installed on the support column of the foundation of the semi-submersible floating fan; nacelle, mounted on top of the tower; Wind turbines and blades, installed at the front end of the nacelle.