JP7430859B1 - Floating offshore wind power generation system - Google Patents

Abstract

[Problem] To provide a floating offshore wind power generation system suitable for sea areas with a sea depth of 50 to 100 meters or more, taking into consideration the increase in the scale of wind power generation devices. [Solution] Two wind power generators 1 are mounted on one polygonal floating body 10, and one of the polygonal vertices of the polygonal floating body 10 is fixed end floating fixed from an anchor on the seabed. , and the other vertices follow the leeward side as the movable end floating portion 4 which is a free end. Power connection equipment will be installed at the fixed end floating section. A vertical bulkhead plate is installed on the support column 2 for supporting the wind power generation device to reduce the interference of turbulence in the wake of the wind power generation propeller 11, and furthermore, the adjacent propeller 11 is rotated in forward and reverse directions to reduce the turbulence in the wake of the propeller. suppress. [Selection diagram] Figure 1

Description

The present invention relates to a floating power generation device applied to offshore wind power generation. Specifically, two wind power generators are mounted balanced on each end of one floating body (the so-called Yajirobe style), which reduces the weight of the device and allows it to be used at depths of about 50 to 100 meters underwater. This is a floating offshore power generation system configured to suit the requirements of the project.

Traditionally, Japan's electricity demand has relied on large-capacity power sources such as hydropower, thermal power, and nuclear power, but Japan's hydropower sources have already been developed in suitable locations due to the natural topography, and nuclear power generation has problems with social consensus. Therefore, the use of natural energy has become an important issue in reducing the CO ₂ concentration in the global environment.
Offshore wind power generation is expected to serve as a large-capacity power source in the development of natural energy. However, since the cost of power generation is two to three times that of thermal power generation, reducing the cost has become an urgent issue.

In Japan, the territorial sea with a continental shelf depth of less than 200 m along the coast of the Japanese archipelago is 455,000 ^km2 , which is 1.2 times the land area of Japan, which is 377,900 ^km2 , but the exclusive economic zone (EEZ) of 4,480,000 ^km2 is 11.9 times larger. Offshore wind power generation equipment is expected. However, in the coastal areas of the Japanese archipelago, there are few shallow waters on the continental shelf, making it difficult to develop large-scale seabed-mounted wind power generation systems. become.

Overseas, bed-mounted wind power generation equipment installed in shallow sea areas at a depth of 20 to 40 m is popular, but there are few shallow sea areas in the coastal areas around the Japanese archipelago, and bed-mounted wind power generation equipment installed in sea areas with a depth of 50 m or more is common. Since the cost is high, there is a need to reduce the cost of offshore floating wind power generators. As prior art related to floating offshore wind power generators, there are inventions described in the following patent documents.

Japanese Patent Application Publication No. 2010-216273 JP 2017-8807 Publication Special Publication No. 2005-5042057 Japanese Patent Application Publication No. 2004-2511397 Special table 2017-5215977 publication

Among the prior art documents mentioned above, the features of the invention described in each patent document are described below.
(Patent Document 1)
The invention described in Patent Document 1 relates to a "foundation structure of a floating offshore wind power generation device," and in order to install one wind power generation device offshore, a cylindrical floating body floating on the ocean is used as the basic structure, and the cylindrical floating body is the center. In this method, an auxiliary cylindrical floating body is arranged and connected to the outer periphery as a countermeasure against rocking.
On the other hand, in the offshore wind power generation system according to the present application, two power generation devices are installed in one set of floating bodies, so the configuration is fundamentally different.
(Patent Document 2)
The invention described in Patent Document 2 relates to a "floating offshore wind power generation device," which is a system in which a floating section for a power generating device that supports an offshore power generating device is connected to a moored floating section fixed on the ocean and installed on the ocean. be.
On the other hand, in the offshore wind power generation system according to the present application, the floating body for the power generation device and the tethered floating body part have an integral structure, so their structures are fundamentally different.
(Patent Document 3)
The invention described in Patent Document 3 relates to a "floating offshore wind power generation facility," which has a floating body that supports a wind power generator, a one-point mooring mechanism, etc., and has three semi-submersible column members on the floating body. are arranged on a plane so that their apexes form a triangle, and one of the column members is moored to the one-point mooring mechanism.
On the other hand, the offshore wind power generation system according to the present application is configured such that the shape of the floating body does not matter; if the shape of the floating body is a polygon in plan view, one point of the apex of the floating body is fixed end floating. The other apexes constituting the floating body have an integrated structure as a movable end floating part that becomes the free end on the leeward side, and two wind power generators are mounted on one set of the floating body, The basic structure is different.
(Patent Document 4)
The invention described in Patent Document 4 relates to a "floating floating wind power generation device." This system is one in which one wind power generation device is mounted at the center of a ring-shaped floating body, and the wind direction is controlled using the center of the ring as a fixed point. The tail is used to follow wind direction.
On the other hand, in the offshore wind power generation system according to the present application, the shape of the floating body is not limited, and if a polygonal floating body is adopted as the floating body, one point of the outer periphery of a polygon such as a triangle or a quadrangle. This is a fixed end floating part on the windward side. Furthermore, in addition to the function of following the wind direction, the vertical tail has the function of a bulkhead plate that prevents interference with adjacent propellers from turbulence in the trailing region of the propeller, which is different in technical configuration from the invention described in Document 4. There is.
(Patent Document 5)
The invention described in Patent Document 5 relates to a "raft for wind power generation/rotating semi-submersible wind power generation and its construction method", and the method is a triangular raft with three wind power generators mounted at each apex. be.
On the other hand, in the offshore wind power generation system according to the present application, a support column (tower part) for the wind power generation device is erected on a floating body having a triangular shape in plan view, and two wind power generation devices are installed on this support column. , the basic structure is different.

Although there is no fundamental difference in the power generating equipment such as propellers, generators, hubs, etc. for wind power generation in offshore wind power generation equipment, there are the following issues in installing the equipment offshore.
(Assignment 1)
For offshore wind power generation, if the sea depth is within 30 to 40 meters, the bottom part of the wind power generator's columnar tower is placed on the seabed, and the columnar tower part is protruded above the sea surface and installed at the top of the tower. This method is popular overseas. However, when the sea depth exceeds 30 to 40 meters, the cost of the submarine-based system becomes high.

(Assignment 2)
The problem with floating offshore power generation systems is preventing the floating structure from shaking during strong winds. If the floating body is a single cylindrical semi-submersible floating body (spar type) as a countermeasure against rocking, the restoring force of the rocking motion can be increased by installing the weight of the submersible part deep under the sea. The depth of the weight part from the sea surface is 1.3 to 1.5 times the height of the power generation device above the sea surface.For example, when installing one 5MW class power generation device, the depth is about 120 meters.

The present invention provides a floating offshore wind power generation system suitable for sea areas with a sea depth of 50 to 100 meters or more, taking into consideration the scale-up of wind power generation devices. Note that the numeral at the end of the term is a common numeral throughout the explanation to be described later, and is added for reference.

As a solution to the above-mentioned problem, the present invention installs two offshore wind power generators on a set of floating bodies, and simultaneously achieves measures against rocking that take into account the floating area of the floating body and sea depth, and cost reduction. Regarding a possible floating offshore wind power generation system.
The invention according to claim 1 provides a plurality of floating parts (3, 4, 4) having buoyancy at positions that are the vertices of a polygon in plan view on the ocean , and each of these floating parts (3, 4, 4). ) are connected by connecting members (5) to form a polygonal floating body (10),
The support column (2) is mounted on the polygonal floating body (10) by connecting the legs of the support column (2) formed as a tower body to the polygonal floating body (10).・Integrate the support column (2) and the polygonal floating body (10) by erecting it,
A columnar part for supporting the wind power generator (1, 1) is provided on the upper part of the support column (2), and the columnar part includes a pair of cantilever support parts (21A, 21B) extending in the left-right direction, One wind power generation device (1, 1) each (two in total) is installed on these pair of cantilever support parts (21A, 21B),
A pair of left and right wind power generator tension cables (22, 22) that bear the vertical load of the wind power generator (1, 1) are installed between the support column (2) and the cantilever support part (21A, 21B). and tie it down,
Among the plurality of floating parts (3, 4, 4), the fixed end floating part (3), which is one of the apexes, is held at approximately a predetermined position on the sea , and the other apexes are connected to the movable end floating parts (4, 4). By doing so, the fixed end floating section (3) is positioned on the windward side, while the movable end floating section (4, 4) follows the windward end as a free end on the leeward side. ) It is characterized by eliminating the need for individual wind direction control.

The invention according to claim 2 is, in the above-mentioned item 1, a vertical partition plate (23) is attached to the support column (2) for supporting the wind power generator (1, 1), and the vertical partition plate (23) allows the adjacent In addition to providing a function to avoid interference due to wake turbulence of the wind power generation propellers (11, 11) of the two wind power generation devices (1, 1), and positioning the fixed end floating part (3) to the windward side. and a wind direction followability improvement function that causes the wind power generation propellers (11, 11) of the wind power generation device (1, 1) to directly face the wind.
At the same time, the wind power generation propellers (11, 11) in the wind power generation device (1, 1) are each controlled to rotate in forward and reverse directions to suppress interference of wake turbulence with adjacent propellers (11, 11). .

According to the invention recited in claim 1 of the present application, in floating offshore wind power generation, two wind power generation devices are mounted on one set of floating bodies (10) in a balanced manner like a so-called toy Yajirobei. Therefore, it can be applied even at sea depths of 50 to 100 meters or more, has excellent mechanical balance, and can improve stability at sea.
Further, according to the invention described in claims 2 and 3, the fixed end floating part (3), which is one point of the apex installed by the anchor from the seabed of the floating body (10), is connected to the power cable lead-in part. In addition, power interconnection equipment (transformers and switches) for two wind power generators can be installed as a power transmission end from the ocean to the land area.
Furthermore, according to the inventions described in claims 2 and 3, wind direction control equipment for each wind power generation device is not required, which can contribute to reducing initial costs and running costs.

1 is a diagram illustrating a first embodiment of an offshore wind power generation system according to the present invention, and is an elevational view seen from a direction perpendicular to the wind direction. Similarly, it is a diagram showing the first embodiment of the offshore wind power generation system according to the present invention, and is an elevational view viewed parallel to the wind direction. Similarly, it is a diagram showing the first embodiment of the offshore wind power generation system according to the present invention, and is a plan view thereof. Similarly, it is a diagram showing main parts of the first embodiment of the offshore wind power generation system according to the present invention, and is a sectional view showing a state in which the fixed end floating section is installed in the sea. Similarly, it is a diagram showing main parts of the first embodiment of the offshore wind power generation system according to the present invention, and is a sectional view taken along the line XX' of the offshore wind power generation system in FIG. 4. Similarly, it is a diagram showing the main parts of the first embodiment of the offshore wind power generation system according to the present invention, and is a plan view of the movable end floating section. FIG. 2 is a diagram showing a second embodiment of the offshore wind power generation system according to the present invention, and is an elevational view seen from a direction perpendicular to the wind direction.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The offshore wind power generation system according to the present invention will be described in detail below with reference to the accompanying drawings.
(First example)
The characteristics of the offshore wind power generation system according to the first embodiment are that a polygonal floating body 10 having a polygonal shape in plan view is used as the “floating body”, two wind power generation devices are mounted on the polygonal floating body 10, and One point among the vertices of the polygonal floating object 10 is connected to the seabed via a fixed end anchor connection chain (34) and a fixed end anchor submarine anchor anchor part (35), thereby being held at approximately a predetermined position on the sea. The fixed end floating part 3 is configured as a fixed end floating part 3, and the other vertices are configured as movable end floating parts 4, which are free ends that follow the leeward side depending on the wind direction.

Figure 1 is an elevational view of the offshore wind power generation system of the first embodiment, viewed from a direction perpendicular to the wind direction, Figure 2 is an elevational view viewed from a direction parallel to the wind direction, and Figure 3 is a plan view. It is a diagram. As shown in these figures, the offshore wind power generation system of this embodiment includes a fixed end floating section 3 and a movable end floating section 4, 4 each having buoyancy, and these floating sections 3, 4, 4. By connecting them with the connecting members 5, 5, 5, a polygonal floating body 10 having a triangular shape in plan view is constructed, as shown in FIG.

Although the connecting members 5, 5, 5 in this embodiment are submerged members, they are not limited to this, and it is also possible to use floating members that float on water. The movable end floating parts 4, 4 are provided with a floating body underwater part 51 and a floating body underwater weight part 52 at their lower positions, and by improving the stability of the movable end floating parts 4, 4, the influence of waves etc. is reduced. are doing.

As shown in FIGS. 1 to 3, a polygonal floating body 10 comprising a fixed end floating section 3, movable end floating sections 4, 4, and connecting members 5, 5, 5 includes a wind power generator. A support column 2, which is a cross-shaped tower body, is mounted and erected. This wind power generation device support column 2 is a tower-shaped support column formed by combining truss members, and the central vertical column has a pair of cantilever support portions (wind power generation device support) extending in the left and right direction. beams) 21A and 21B are provided. At the ends of these pair of cantilever supports 21A and 21B, wind power generators 1 and 1 each with the same power output are installed to achieve balance, creating a so-called toy Yajirobee. As a result of applying this principle, it contributes to improved stability.

Further, between the part where the wind power generators 1, 1 are supported and the upper end of the columnar part , wind power generator tension cables 22, 22 as stabilizing members are stretched and secured. It is now possible to install the two wind power generators 1, 1 without losing their weight balance while reinforcing the installation parts. That is, the wind power generator tension cables 22, 22, which are stabilizing members, bear a part of the vertical load of the wind power generators 1, 1, and thus have a function of improving the dynamic balance of the entire system.

In this embodiment, metal wire ropes are used for the wind power generator tension cables 22, 22 in consideration of reducing wind resistance, but other applicable members include wire ropes with adjustable tension. It is also possible to use steel materials with corrosion resistance and wind resistance that are suitable for use at sea, such as steel bars with buckles.

Furthermore, as shown in FIGS. 2 and 3, the lower ends of the support column 2 formed in a tower shape are connected to the fixed end floating section 3 of the polygonal floating body 10, the movable end floating section 4, It is installed and supported on 4. As a result, the support column 2 is integrated with the polygonal floating body 10, resulting in a structure with improved robustness and rigidity, ensuring wave resistance and wind resistance.

Each of the wind power generation propellers 11, 11 in the wind power generation devices 1, 1 is controlled to rotate in forward and reverse directions during power generation, and interference of wake turbulence on the adjacent propellers 11, 11 is suppressed. There is.

FIG. 4 is a sectional view showing how the fixed end floating section 3 is installed in the sea, and FIG. 5 is a plan sectional view of the fixed end floating section 3.
As shown in FIG. 4, the fixed end floating section 3 includes a fixed end rotating floating section 31 and a fixed end stationary floating section 32 that have buoyancy. The upper end of the anchor 34 is attached, and the lower end thereof is connected to a fixed-end anchor submarine fixing part 35 installed on the seabed, thereby holding the fixed-end floating part 3 at a fixed position on the ocean.
As shown in FIG. 5, the fixed end rotating floating section 31 is fitted onto the upper part of the fixed end stationary floating section 32 from above via the fixed end rotating shaft bearing 33. It is rotatably provided relative to 32.

Further, in FIG. 4, a twistable electric wire 62 is inserted vertically into the inside of the fixed end stationary floating section 32 of the fixed end floating section 3, and is connected to the power cable 6 via the power cable head 61 at the lower end. There is. The power cable 6 serves as a power transmission line for the power generated by the wind power generator and is connected to a power transmission facility on land.
Furthermore, a power linking facility 36 is installed in the fixed end floating section 3 to collectively transmit the output of the two wind power generators to the outside.

The twistable electric wire 62 is twisted depending on the wind direction, but in order to eliminate the twist, as shown in FIG. The restoring underwater propulsion screw 41 rotates the fixed end floating section 3 and the movable end floating sections 4, 4 in a direction opposite to the twisting direction of the power cable 62, thereby eliminating the twisting. In other words, the underwater propulsion screw 41 for torsion restoration is capable of forward and reverse rotation, and during operation, the polygonal floating body 10 consisting of the fixed end floating section 3 and the movable end floating section 4, 4 is rotated in the twisting direction of the power cable 62. The twist is restored by rotating it in the opposite direction.

An example of a practical design of a floating offshore wind power generation system configured in this way will be shown. The design example below uses 2.5MW x 2 units = 5MW class floating offshore power generation equipment.

Offshore power generation equipment/Rated output 2.5MW x 2 units = 5MW
・Floating body configuration Polygonal floating body: Circular floating body (fixed end and movable end floating part ~ triangular arrangement
Connecting member: Side length 50m, underwater truss structure, columnar tower body (wind power generation equipment support column)
Upper part: Floating body steel hollow cylindrical structure, power generation equipment installed at both ends of horizontal beams with cross configuration Lower part: Steel truss structure, vertical bulkhead plates installed, rated wind speed 12 m/s, cut-in wind speed 3.5 m/s, cut-out wind speed 25m/sec・Rotor diameter 90m
・3 propeller blades ・Propeller arrangement downwind (generator installed on the leeward side)
・Generator drive method Direct drive (directly connected to propeller shaft)
・Generator type: Horizontal axis permanent magnet excitation synchronous generator

(Second example)
A second embodiment of the offshore wind power generation system according to the present invention is configured as follows. The offshore wind power generation system according to the second embodiment differs from the first embodiment in that a single cylindrical (spar type) floating body 7 is used as the "floating body".
In the following description, members similar to those in the first embodiment described above are given the same reference numerals, and detailed description thereof will be omitted.

FIG. 7 is a diagram showing the offshore wind power generation system of the second embodiment, and is an elevational view viewed from a direction perpendicular to the wind direction.
The offshore wind power generation system shown in the figure includes a single cylindrical floating body 7 and a cross-shaped wind power generation device support column 2 that is erected and supported by the single cylindrical floating body 7. The floating body 7 and the wind power generator support column 2 have the strength to support the two wind power generators 1, 1.
Further, the single cylindrical floating body 7 is provided with a floating body underwater part 71 and a floating body underwater weight part 72 at a lower position.
Although spar-type floating bodies have a simple structure, are easy to manufacture, and are inexpensive, they are somewhat unsuitable for installation in shallow waters; Select the optimal floating object considering output etc.

In the first and second embodiments to which the present invention is applied, two wind power generators 1 and 1 are used, so for example, a 5MW class power generator requires a 2.5MW class power generator. Two devices will be installed. On the other hand, when installing one large power generation device, the wind turbine becomes larger and the rotor diameter of the blades increases, which increases the weight, and the propeller support structure connected to the generator main shaft of the power generation device is cantilevered. This poses problems regarding the strength of the main shaft of the generator, but since it can be made smaller by using two generators, it is possible to avoid excessively increasing the size of the equipment itself. .

As described above, according to the offshore wind power generation system of the present invention, the floating body can be used in various forms of offshore wind power generation, such as TLP type, semi-sub type, and barge type floating bodies.

In the floating offshore wind power generation system of the present invention, two wind power generators are installed for one floating body in a so-called Yajirobe-shaped arrangement to achieve weight balance, and at the same time take measures against rocking in mid-deep sea areas and reduce costs. reduction is achieved. The present invention has applicability in the electric power business field. Further, since the present invention does not care about the shape of the floating body on the ocean, it can be applied to various types of offshore wind power generation systems.

Explanation of component numbers constituting the offshore wind power generation device group 1: Wind power generation device 10: Polygonal floating body 11: Wind power generation propeller 2: Wind power generation device support columns 21A, 21B: Cantilever support part (wind power generation device support beam) )
22: Wind power generator tension cable (stabilizing member)
23: Support column attached vertical bulkhead plate 3: Fixed end floating section 31: Fixed end rotating floating section 32: Fixed end stationary floating section 33: Fixed end rotating shaft bearing 34: Fixed end anchor connecting chain 35: Fixed end anchor submarine anchor anchor Part 36: Power connection equipment 4: Movable end floating section
41: Underwater propulsion screw for twist recovery 5: Connecting member 51: Floating body underwater part 52: Floating body underwater weight part 6: Power cable 61: Power cable head 62: Twistable electric wire 7: Single cylindrical floating body 71: Floating body underwater part
72: Floating underwater weight part

Claims (2)

A polygonal floating body is formed by providing a plurality of floating parts with buoyancy at the vertices of a polygon in plan view on the ocean , and connecting these floating parts with respective connecting members,
By connecting the legs of a support column formed as a tower body to the polygonal floating body, the support column is mounted and erected on the polygonal floating body, and the support column and the polygon are connected to each other. Integrate with the square floating body,
A columnar part for supporting the wind power generation device is provided on the upper part of the support column, and the columnar part is provided with a pair of cantilever support parts extending in the left-right direction, and the wind power generation device is mounted on these pair of cantilever support parts. In addition to installing one of each (total of two),
A pair of left and right wind power generation device tension cables that bear the vertical load of the wind power generation device are installed and secured between the support column and the cantilever support part,
Among the plurality of floating parts, the fixed end floating part, which is one point at the apex, is held at a substantially predetermined position on the sea , and by setting the other apexes as movable end floating parts, the fixed end floating part is positioned to the windward side. An offshore wind power generation system characterized in that the movable end floating section follows the movable end as a free end to the leeward side, thereby eliminating the need for individual wind direction control of the wind power generation device. A vertical partition plate is attached to the support column for supporting the wind power generation device , and the vertical partition plate provides a function of avoiding interference due to wake disturbance of wind power generation propellers of two adjacent wind power generation devices, and Also, a fixed end floating part is positioned on the windward side to provide a wind direction followability improvement function that allows the wind power generation propeller of the wind power generation device to directly face the wind,
2. The offshore wind power generation system according to claim 1, wherein the wind power generation propellers in the wind power generation device are each controlled to rotate in forward and reverse directions to suppress interference of wake turbulence with adjacent propellers.

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