JP7569003B2 - Pillar-shaped float, pillar-shaped float erection system, and pillar-shaped float erection method - Google Patents

Description

The present invention relates to a columnar float that constitutes a floating offshore wind power generation facility, and more specifically, to a columnar float into which seawater can be poured using the siphon effect, and a system and method for erecting the columnar float.

Although electricity consumption in Japan temporarily began to decline due to the impact of the global financial crisis in 2008, it has been increasing continuously since the oil shock of 1973, expanding 2.6-fold between fiscal 1973 and 2007. The reasons for this include the spread of so-called home appliances such as air conditioners and electric carpets as living standards improve, and the spread of office automation (OA) equipment and communication devices as the number of office buildings increases.

Until now, this enormous demand for electricity has mainly been met by power generation using so-called fossil fuels such as oil and coal. However, in recent years, attention has been focused on the depletion of fossil fuels and environmental issues associated with global warming, and power generation methods have gradually changed in response. As a result, while around 1973, as mentioned above, power generation using oil and coal accounted for about 90% of all power generation, by 2010 this proportion had fallen to 66%. Instead, nuclear power generation has increased, accounting for just over 10% of the total (2010). Nuclear power generation has a significant effect on reducing greenhouse gas emissions compared to conventional power generation methods, and can provide electricity at low cost, making it a major contributor to Japan's electricity demand.

Furthermore, power generation methods using renewable energy sources are being adopted because they can reduce greenhouse gas emissions. Renewable energy is literally energy that can be reproduced, such as solar, wind, geothermal, small and medium-sized hydroelectric power, and woody biomass. Since they reduce greenhouse gas emissions and can be produced domestically, they are seen as a promising source of low-carbon energy.

Among renewable energies, wind power generation has the advantage of high conversion efficiency of electrical energy. In general, the conversion efficiency of solar power generation is about 20%, woody biomass power generation is about 20%, and geothermal power generation is 10-20%, while wind power generation is said to be 20-40%, so it can convert energy into electricity more efficiently than other power generation methods. Another advantage of wind power generation is that, unlike solar power generation, it can generate electricity both day and night. Due to these characteristics, wind power generation is already widely used as a major power generation method in Europe, and in Japan, as part of the "energy mix" initiative, the goal is for wind power to account for 1.7% of the power source mix by 2030.

Wind power generation can be broadly divided into onshore and offshore wind power generation depending on where it is installed, with onshore wind power generation being easier to install than offshore wind power generation, and therefore having the advantage of being able to keep costs down. On the other hand, offshore wind power generation does not have the noise problems that onshore wind power generation faces, and it also avoids the risk of damage from falling over, and above all has the advantage of being able to obtain greater wind power stably than on land. Japan, which has the sixth largest exclusive economic zone in the world, is an ideal location for offshore wind power generation, and is thought to have the potential to become a promising producer of renewable energy in the future.

Different types of offshore wind turbines are used depending on the installation location, with fixed-bottom offshore wind turbines being suitable for sea areas shallower than 50 meters, and floating offshore wind turbines being suitable for sea areas deeper than 50 meters. Of these, floating offshore wind turbines use floats that float on seawater, and generate electricity by installing a power generation mechanism on the float connected by mooring lines. Floating types include pontoon types (barge type), semi-submersible types, spar types (column type), and tension leg platforms (TLPs), and in offshore areas far from land where large wind power is expected to be obtained, column types tend to be mainly used.

Figure 9 is a side view showing a typical columnar offshore wind power generation facility. As shown in this figure, a columnar offshore wind power generation facility is composed of a columnar float (spar float) that is floated in the sea, and a tower, rotor, nacelle, etc. that are installed on top of it. The tower is a structure that supports the rotor and nacelle, and the columnar float functions as the foundation of the tower. The rotor, which is made up of blades and a hub, converts wind into power, and the nacelle, which includes a gearbox, generator, transformer, etc., converts the power into electricity, which is transmitted to land via an undersea cable. Note that columnar floats are generally moored by the weight of a catenary-shaped mooring rope.

The main body of the columnar float is a long body whose axial dimension (hereinafter referred to as "column axis") is larger than its cross-sectional dimension, and has a hollow tubular shape. As shown in FIG. 9, the columnar float is in a state where its column axis direction is approximately vertical (including vertical) (hereinafter referred to as "upright state") during operation. Normally, this columnar float is manufactured on land, such as in a dry dock, and therefore needs to be transported by sea to the operation site (wind farm: WF). Although there are some examples of columnar floats being transported in an upright state in some places, such as Northern Europe, in Japan, where the water around land is shallow, the columnar float is transported with its column axis direction approximately horizontal.

Therefore, to put the columnar float into an operational state, it is necessary to rotate the columnar float from a nearly horizontal state to an upright state (hereinafter referred to as "standing up"). Note that wind farms are not suitable locations for erecting columnar floats because they are expected to be subject to considerable wind force, and so they are erected in a pre-selected calm area of the ocean. In addition, the tower, rotor, nacelle, etc. are manufactured separately from the columnar float and transported to the wind farm, where they are installed on the erected columnar float using a crane ship or the like. The structure, which is largely completed as an offshore wind power generation facility, is then transported to the wind farm in the operational state (i.e., with the columnar float in an upright position).

Conventionally, to erect a columnar float, as shown in Patent Document 1, ballast water (e.g., seawater) is pumped into the main body of the columnar float to erect it.

JP 2012-201217 A

Figure 10 is a step diagram showing the conventional procedure for erecting a columnar float. With reference to this figure, the conventional procedure for erecting a columnar float will be described. First, as shown in Figure 10(a), the columnar float manufactured in a dry dock or the like is transported by a tugboat to the sea in a preselected calm area. When the columnar float is transported to the target calm area, seawater is injected into the main body using a pump as shown in Figure 10(b). Since a concrete or other weight is provided at the bottom of the columnar float, the columnar float is in a slightly sunken inclined state before the start of seawater injection. Therefore, as the seawater injection progresses, the inclination angle (the intersection angle between the horizontal plane and the column axis direction of the columnar float) becomes larger as shown in Figure 10(c), and finally the columnar float becomes upright as shown in Figure 10(d). Then, seawater injection is further advanced from the state shown in Figure 10(d) to sink the columnar float until the planned draft is obtained.

When carrying out various offshore construction projects, attention must always be paid to tides and waves, and since it cannot be expected that the sea surface will remain stable for an extended period of time, efforts are made to complete each process as quickly as possible. Of course, it is also desirable to complete the work of erecting a columnar floating structure in a short period of time, and it is not uncommon for the construction period to be planned to be a few days (for example, 1-2 days).

However, the columnar floats that make up the floating offshore wind power generation facility have a considerable diameter and axial length, and therefore a considerable amount of seawater must be pumped in to sink the columnar float down to the designed draft. In other words, a considerable number of pumps are required to pump a large amount of seawater in a short period of time. Furthermore, as can be seen from Figure 10(d), the required head is high immediately after the columnar float becomes upright (before it reaches the designed draft), and pumps with a relatively large output must be prepared.

For example, when a columnar floater with a diameter of about 10 m and a total length of about 120 m is submerged to the designed draft, 17,000 ^m3 of seawater will be injected. The draft immediately after the columnar floater is upright is about 60 m, so a large-scale pump (for example, with a discharge rate of ³ m3/min) that can pump seawater to a height of 60 m (120 m - 60 m) or more is required. If the water injection construction is planned for one day, and the construction time per day is six hours, 17 pumps with a discharge rate of 3 ^m3 /min must be prepared.

Thus, the conventional technology of using pumps to inject seawater into the main body of a columnar floating structure requires the preparation of many large pumps. Moreover, the barges on which the pumps are mounted and the power equipment to operate the pumps are large, and a considerable number of workers are required to control the pumps. In other words, the costs of the pumps and barges (rent and fuel, etc.) and labor costs are high, and conventional water injection construction requires a considerable budget. In addition, the use of many pumps naturally requires a large number of hoses to be handled, making the tasks of arranging, controlling, and removing the hoses extremely complicated and difficult, and safety was also a concern.

The objective of the present invention is to solve the problems inherent in the prior art, namely to provide a columnar floating body that can be erected more easily and at lower cost than conventional methods, as well as a system and method for erecting the columnar floating body.

The present invention was developed with a focus on the use of the siphon effect to inject seawater into the columnar body of a columnar float, and is based on a completely new idea.

The columnar floating body of the present invention constitutes a floating offshore wind power generation facility, and comprises a hollow columnar body with a weight attached to the bottom, and a connecting pipe with a water intake and a water inlet. The water intake is located on the outside of the columnar body, and the water inlet is located on the inside of the columnar body near the bottom, and the columnar body floats on the sea surface in a tilted, sideways state with part of the bottom side submerged below the seawater level. When the water intake is located in seawater, the connecting pipe is filled with water, and the water inlet is located below the seawater level, seawater flowing in from the water intake is injected into the columnar body through the water inlet by a siphon effect.

The columnar floating body of the present invention may also be configured such that the connecting pipes include a water intake pipe, a water injection pipe, and an upper relay pipe. The water intake pipe is provided with a water intake port, the water injection pipe is provided with a water injection port, and the water intake pipe and the water injection pipe are connected by the upper relay pipe. In this case, the water intake pipe, which is approximately parallel (including parallel) to the column axis direction of the columnar body, is placed on the outside of the columnar body, and seawater flowing in from the water intake port rises inside the water intake pipe, passes through the upper relay pipe, and flows down inside the water injection pipe.

The columnar floating body of the present invention can also have the water intake pipe disposed inside the columnar body. In this case, a portion of the water intake pipe on the water intake side is formed as a curved pipe, and this curved pipe penetrates the columnar body, so that the water intake is disposed outside the columnar body.

The columnar floating body of the present invention may also be configured such that the connecting pipe includes a middle bypass pipe. The middle bypass pipe connects the water intake pipe and the water injection pipe, and is positioned so that it is lower than the upper relay pipe when a predetermined amount of seawater is injected and the columnar body is in an upright position. When the height of the upper relay pipe from the seawater surface exceeds the limit height for siphon action (e.g., 10 m), the seawater that rises in the water intake pipe flows down the water injection pipe via the middle bypass pipe.

The columnar floating body of the present invention may be provided with a check valve in the connecting pipe near the water intake. This check valve can prevent backflow of seawater from the water intake pipe to the water intake.

The columnar floating body of the present invention can also be designed so that the water intake is positioned in seawater even when the columnar body is in an upright position.

The columnar floating body of the present invention may further include an air valve that controls the flow of air into and out of the connecting pipe. This air valve is arranged so that it is located in the air inside the columnar body even when a predetermined amount of seawater is poured in and the columnar body reaches the planned height.

The columnar float erection system of the present invention erects the columnar float of the present invention in an upright state with seawater, and is a system equipped with an air valve control means and a water injection means. The air valve control means is a means for controlling the air valve by remote operation by an operator, and the water injection means is a means for injecting seawater into the connecting pipe by remote operation by the operator. When the operator operates the water injection means with the columnar body lying on its side, seawater is injected into the connecting pipe while removing the air from the air connecting pipe (when the air valve is open). When the operator closes the air valve by the air valve control means with the connecting pipe filled with water, seawater flowing in from the water intake is injected into the columnar body through the water injection port by the siphon action. When the operator opens the air valve by the air valve control means, the injection of water into the columnar body by the siphon action is stopped.

The method for erecting a columnar float of the present invention is a method for erecting the columnar float of the present invention in an upright state with seawater, and is a method including a process of injecting water into the pipe and a process of injecting water into the main body. In this process, seawater is injected into the connecting pipe while removing the air from the connecting pipe with the columnar body laid on its side. In the process of injecting water into the main body, the connecting pipe is filled with water to utilize the siphon effect, and seawater flowing in from the water intake is injected into the columnar body through the water inlet.

The method for erecting a columnar floating body of the present invention can also be a method further comprising a water injection stopping step. In this water injection stopping step, the air valve is opened when the columnar body in an upright state is positioned at the planned height by the water injection step into the body. In this case, in the water injection step into the pipe, the air valve is opened to inject seawater into the connecting pipe while removing the air from the connecting pipe, and when the connecting pipe is filled with water, the air valve is closed. In the water injection stopping step, air is sent into the connecting pipe by opening the air valve, and the injection of water into the columnar body by the siphon effect is stopped.

The columnar floating body erection method of the present invention can also be a method further comprising a water intake pipe removal process and an opening sealing process. In this water intake pipe removal process, the water intake pipe arranged on the outside of the columnar body is removed after the columnar body is brought to the planned height by the water injection process inside the body. In the opening sealing process, the opening of the columnar body that is created after the water intake pipe is removed is sealed with a sealing material.

The pillar-type floating body, the pillar-type floating body erection system, and the pillar-type floating body erection method of the present invention have the following effects.
(1) There is no need to use a large-scale, high-capacity pump to inject seawater into the main body of the columnar floating body, which reduces the costs and labor costs associated with pumps, barges, and other equipment. In other words, the construction costs for water injection can be significantly reduced compared to conventional technologies.
(2) Since water is injected using the siphon effect, complex control is not required, and work interruptions due to malfunctions in electrical equipment or other unforeseen circumstances can be reduced, meaning that the entire process can be carried out smoothly.
(3) Since there is no need to handle a large number of pumps and hoses, workability and safety are improved compared to conventional techniques.

FIG. 2 is a step diagram showing each stage of erecting the column-shaped floating body of the present invention. FIG. 2 is a side view showing a schematic diagram of the pillar-shaped floating body of the present invention. FIG. FIG. 2 is a side view showing a schematic diagram of the columnar floating body of the present invention in which a water intake pipe is arranged on the inside of the columnar body. FIG. 2 is a side view showing a schematic diagram of a pillar-shaped floating body of the present invention provided with a middle-stage bypass pipe. 1A is a side view diagrammatically showing the direct-type column-type floating body 200 laid on its side, and FIG. 1B is a side view diagrammatically showing the direct-type column-type floating body 200 in an upright state. FIG. 1 is a block diagram showing the main configuration of the column-type floating body erection system of the present invention. FIG. 2 is a flow chart showing the main steps of the method for erecting a column-shaped floating body of the present invention. FIG. 1 is a side view showing a schematic diagram of a spar-type offshore wind power generation facility. FIG. 1 is a step diagram showing the conventional procedure for erecting a column-shaped floating body.

An example of an embodiment of the columnar float (spar float), columnar float erection system, and columnar float erection method of the present invention will be described with reference to the drawings. The columnar float of the present invention can be particularly preferably implemented when used as part of a floating offshore wind power generation facility, and the columnar float erection system and columnar float erection method of the present invention can be particularly preferably implemented when erecting the columnar float of the present invention.

1. Overall Overview First, an overview of the present invention will be described with reference to Fig. 1. Fig. 1 is a step diagram showing each step of erecting a columnar type floating body 100 of the present invention. The columnar type floating body 100 of the present invention is composed of a columnar body 110, a connecting pipe 120, and a weight 130, and if the inside is hollow (if seawater is not poured in) as shown in Fig. 1(a), it floats on the sea in a sideways state. However, since the weight 130 is provided at the bottom of the columnar body 110, the column axis direction is not horizontal, and the bottom side is inclined so that it floats on the sea.

In FIG. 1(a), the water intake 121E at one end of the communicating pipe 120 is located in seawater (under seawater), and the water inlet 122E at the other end of the communicating pipe 120 is located below the seawater level. When the communicating pipe 120 is filled with water in this state, seawater flows in from the water intake 121E and through the communicating pipe 120 due to the siphon principle, and is injected into the columnar body 110 from the water inlet 122E.

As described above, the hollow columnar body 110 is inclined so that the bottom side sinks, and as seawater is poured in, the inclination angle (the intersection angle between the horizontal plane and the column axis direction of the columnar body 110) increases as shown in FIG. 1(b), meaning that the columnar float 100 rotates (counterclockwise in the figure) on a substantially vertical (including vertical) plane, meaning that the columnar float 100 gradually stands upright. Then, when a predetermined amount of seawater is poured into the columnar body 110, it stands upright in an "upright state" in which the column axis direction is substantially vertical (including vertical) as shown in FIG. 1(c). For convenience, the state when the columnar body 110 finishes rotating (i.e., immediately after it becomes upright) is referred to as the "initial upright state". As shown in Figures 1(c) and 1(d), the space (hollow portion) within the columnar floating body 100 where seawater does not accumulate (i.e., there is no seawater) is referred to as the "air space."

Even after the columnar body 110 is initially set in an upright state, water injection due to the siphon effect continues, so the columnar float 100 continues to sink in the sea while remaining in an upright state. Then, as shown in FIG. 1(d), when the columnar float is sunk to the height of the planned draft, air is sent into the connecting pipe 120 to eliminate the siphon state, i.e., seawater injection into the columnar body 110 is stopped. For convenience, the state in which the columnar float 100 is sunk to the height of the planned draft is referred to as the "planned height state."

2. Pillar-type float Next, the pillar-type float 100 of the present invention will be described in detail with reference to the drawings. The pillar-type float erection system of the present invention is a system for erecting the pillar-type float 100 of the present invention, and the pillar-type float erection method of the present invention is a method for erecting the pillar-type float 100 of the present invention. Therefore, the pillar-type float 100 of the present invention will be described first, and then the pillar-type float erection system of the present invention and the pillar-type float erection method of the present invention will be described in detail.

Figure 2 is a side view showing a schematic diagram of the columnar type floating body 100 of the present invention. As shown in this figure, the columnar type floating body 100 of the present invention is composed of a columnar body 110, a connecting pipe 120, and a weight 130, and can also be composed of a first air opening and closing valve 140, a check valve 150, a diameter reducing body 160, a connecting body 170, and a second air opening and closing valve 180. Below, each of the main elements that make up the columnar type floating body 100 will be explained.

(Columnar body)
As shown in FIG. 2, the column body 110 is an elongated body whose axial dimension is larger than its cross-sectional dimension, and is hollow inside, i.e., its external shape is generally tubular. The column body 110 is a so-called open-bottomed tube, with one end (the lower end in the figure) closed and the other end (the upper end in the figure) open. A weight 130 is installed at the bottom of the column body 110. This weight 130 is made of a material with a large unit weight, for example, concrete or steel. The weight per unit length in the column axial direction is larger in the section where the weight 130 is installed than in other sections of the column body 110 (sections where the weight 130 is not installed). The column body 110 can be a cylindrical column with a circular cross section, or a rectangular column with a polygonal cross section.

(Communicating pipe)
3 is a side view showing the communication pipe 120. The communication pipe 120 is a pipe that allows seawater outside the column body 110 to flow into the column body 110, and has a water intake port 121E at one end (the lower right end in the figure) and a water inlet port 122E at the other end (the lower left end in the figure). The communication pipe 120 can be composed of a water intake pipe 121 provided with the water intake port 121E, a water inlet pipe 122 provided with the water inlet port 122E, and an upper relay pipe 123 that connects the water intake pipe 121 and the water inlet pipe 122. In this case, as shown in FIG. 2, the water intake pipe 121 and the water inlet pipe 122 are preferably arranged roughly along the column axis direction of the column body 110, and the upper relay pipe 123 is preferably arranged roughly perpendicular to the column axis direction of the column body 110. When arranged in this manner, for example, when the column main body 110 is in an upright position, the water intake pipe 121 and the water injection pipe 122 are oriented in an approximately vertical (including vertical) direction, and the upper relay pipe 123 is oriented in an approximately horizontal (including horizontal) direction above the main body 110.

As mentioned above, when the water intake 121E is located in the seawater and the water inlet 122E is located below the seawater level, and in this state the connecting pipe 120 is filled with water, seawater flows into the columnar body 110 by siphon action. In other words, in order to inject seawater into the columnar body 110 from a state in which it is laid down on its side as shown in FIG. 1(a), the water inlet 122E should be located on the inside of the pipe of the columnar body 110 near the bottom (i.e., near the weight 130). Due to the effect of the weight 130, a part of the bottom side of the columnar body 110 sinks below the seawater level, and as a result, the water inlet 122E located near the weight 130 can also be located below the seawater level.

The water intake 121E through which seawater flows in is naturally arranged on the outside of the pipe of the columnar body 110 since it comes into contact with seawater. In addition, since water needs to be continuously injected until the columnar float 100 reaches the planned height state (FIG. 1(d)), in other words, the water intake 121E needs to be located in seawater even when the columnar float 100 reaches the planned height state, it is preferable to arrange the water intake 121E as close to the bottom of the columnar body 110 as possible (a relatively low position of the columnar body 110 in the upright state). For example, in FIG. 2, the water intake 121E is arranged at approximately the same position (height) as the water inlet 122E, but farther from the bottom than the water inlet 122E (i.e., a higher position). Of course, as long as the water intake 121E can be located in the seawater even when the columnar floating body 100 is at the planned height, it can be located anywhere, such as near the middle of the columnar body 110 (i.e., at a position significantly higher than the water inlet 122E), not limited to near the water inlet 122E.

As shown in Figures 2 and 3, a check valve 150 may be installed near the intake port 121E of the intake pipe 121. This check valve 150 can prevent backflow of seawater from inside the intake pipe 121 to the intake port 121E. In particular, backflow of seawater is likely to occur in the early stages of the siphoning process, and providing a check valve 150 is preferable because it prevents this initial backflow and allows smooth water injection to continue.

To inject water by siphon action, the inside of the communicating pipe 120 needs to be forcibly filled with water. For this purpose, a means for pumping water (seawater) (e.g., a pump) and an inlet for the pressurized water (seawater) to flow into the communicating pipe 120 are provided. Note that the inlet provided in the communicating pipe 120 needs to be closed when injecting water by siphon action, so it is advisable to provide an opening/closing valve (opening/closing valve) that can control the open and closed states.

In addition, while water (seawater) is flowing into the communicating pipe 120, it is necessary to send the air inside the communicating pipe 120 to the outside, while when pouring water by siphon action, it is necessary to block the inflow of air into the communicating pipe 120 from the outside. For this reason, it is advisable to provide a first air on-off valve 140 (on-off valve) in part of the communicating pipe 120. This first air on-off valve 140 can control the open and closed states, and when in the open state, it can send the air inside the communicating pipe 120 to the outside, and when in the closed state, it can block the inflow of air into the communicating pipe 120 from the outside.

When the columnar float 100 reaches the planned height, the water injection by the siphon action is stopped. At this time, if the first air valve 140 is provided on the communication pipe 120, the first air valve 140 can be opened to send air from the outside into the communication pipe 120 and eliminate the siphon state. The first air valve 140 can be controlled by remote control by an operator, or can be operated directly by an operator. In the case where the operator directly operates the first air valve 140, the first air valve 140 should be provided so that it is located in the air inside the columnar body 110 even when the columnar float 100 reaches the planned height. This allows the first air valve 140 to be operated by normal air work without the need for diver work.

The water intake pipe 121 constituting the communication pipe 120 can be arranged on the outside of the columnar body 110 as shown in FIG. 2, or on the inside of the columnar body 110 as shown in FIG. 4. When the water intake pipe 121 is arranged on the outside of the columnar body 110 (FIG. 2), the upper relay pipe 123 may be passed through the columnar body 110. On the other hand, when the water intake pipe 121 is arranged on the inside of the columnar body 110 (FIG. 4), a part of the water intake pipe 121 on the water intake port 121E side may be formed as a curved pipe, and this curved pipe part may be passed through the columnar body 110 to place the water intake port 121E on the outside of the pipe. Furthermore, the water injection pipe 122 may also be arranged on the outside of the columnar body 110 together with the communication pipe 120. In this case, a portion of the water injection pipe 122 on the water injection port 122E side can be formed as a curved pipe, and the curved pipe portion can be passed through the columnar body 110 to position the water injection port 122E on the inside of the pipe.

According to the siphon principle, the liquid can be raised, so to speak, but it cannot be raised beyond the height at which atmospheric pressure can push the liquid in the tube (hereinafter referred to as the "limit height"). This limit height varies depending on the specific gravity of the liquid, and is 760 mm for mercury and 10 m for water. Here, depending on the axial length (length in the column axis direction) of the columnar float 100, the height difference between the seawater level and the upper relay pipe 123 may exceed the limit height when it is initially in an upright state (Figure 1 (c)). For example, in Figure 5, the upper relay pipe 123 is located at a position beyond the limit height from the seawater level, so part of the pipe is in a vacuum state and water is not poured into the columnar body 110.

In cases where the upper relay pipe 123 is expected to exceed the limit height above sea level, it is advisable to provide a middle bypass pipe 124 as shown in Figure 5. This middle bypass pipe 124 is a pipe that relays between the middle of the water intake pipe 121 and the middle of the water injection pipe 122, and is arranged so that it is lower than the upper relay pipe 123 when the columnar body 110 is in an upright state, and is also arranged so that it is below the limit height above sea level when it is initially in an upright state. In this way, when the height of the upper relay pipe 123 exceeds the limit height above sea level, the seawater that has risen inside the water intake pipe 121 can flow down inside the water injection pipe 122 via the middle bypass pipe 124.

(Reduced diameter body and connecting body)
The diameter reducing body 160 is connected to the tower (FIG. 9) that supports the rotor and the nacelle, and is, so to speak, an adjustment section for changing the diameter of the column body 110 from the large diameter to the small diameter of the tower. For this reason, as shown in FIG. 2 and FIG. 4, the diameter reducing body 160 is provided on the upper end side of the column body 110 in the upright state, and is made into a truncated cone shape (i.e., a tapered shape) whose cross-sectional area decreases from the column body 110 toward the outside in the column axis direction (upward in the figure). The connecting body 170 is a member that is connected to the tower, and is made into a columnar shape with a small diameter adjusted by the diameter reducing body 160.

Meanwhile, while water is being poured into the columnar body 110, the opening of the columnar body 110 on the connector 170 side may be closed by a lid. In this case, air cannot be sent out when water is poured into the columnar body 110. Therefore, it is recommended to provide a second air valve 180 (opening and closing valve) for exhausting air from the columnar body 110 to the outside. This second air valve 180 can control the open and closed states, and when it is in the open state, it can send air from the columnar body 110 to the outside, and when it is in the closed state, it can block the inflow and outflow of air between the outside and the columnar body 110. The second air valve 180 should be installed so that it is on the upper side when the columnar floating body 100 is laid down on its side so that the water intake pipe 121 (water intake port 121E) is on the lower side as shown in FIG. 1(a).

(Modification)
So far, we have described the pillar-type float 100 that can inject seawater into the pillar-shaped body 110 by utilizing the siphon action. Here, we will describe a pillar-type float that can directly inject seawater into the pillar-shaped body 110 without utilizing the siphon action (hereinafter, for convenience, referred to as a "direct type pillar-type float 200") with reference to Fig. 6. Fig. 6(a) shows the direct type pillar-type float 200 laid down on its side, and Fig. 6(b) shows the direct type pillar-type float 200 in an upright state.

As shown in FIG. 6, the direct columnar float 200, like the columnar float 100, is configured to include a columnar body 210 and a weight 230, and can also be configured to include a diameter reducing body 250, a connecting body 260, and a second air opening and closing valve 270. However, unlike the columnar float 100, it does not have a connecting pipe 120, but instead has a direct water inlet 220 and a valve opening control means 240.

The direct water inlet 220 is an opening that can be changed between an open state and a closed state. When in the open state, seawater can flow into the columnar body 210, and when in the closed state, seawater is blocked from flowing into the columnar body 210. The opening control means 240 is a means that can control the direct water inlet 220 to either an open state or a closed state. For example, the opening control means 240 shown in FIG. 6 is composed of an operating rod 241 and a transmission shaft 242, and the operator operates the operating rod 241 to operate the transmission shaft 242, thereby opening or closing the direct water inlet 220. The opening control means 240 is not limited to a mechanical control type as shown in FIG. 6, but can also be a type that controls the state of the direct water inlet 220 by an electrical signal.

In FIG. 6(a), the direct water inlet 220 is open, and seawater is injecting into the columnar body 210 through the direct water inlet 220. As with the columnar float 100, the direct columnar float 200, which is hollow inside, is inclined so that the bottom side sinks due to the effect of the weight 230, so as the injection of seawater progresses, the angle of inclination increases and the direct columnar float 200 gradually rises up. Then, when a predetermined amount of seawater is injected into the columnar body 210, the direct columnar float 200 rises upright as shown in FIG. 6(b). Even after the direct columnar float 200 is initially in an upright state, the direct water inlet 220 is open, and therefore the direct injection of seawater continues, so the direct columnar float 200 continues to sink in the sea while remaining in an upright state. Then, when the direct columnar floating body 200 reaches the planned height, the operator operates the opening control means 240 to close the direct water inlet 220 and stop the injection of seawater into the columnar body 110.

3. Pillar-type floating body erection system Next, the pillar-type floating body erection system of the present invention will be described in detail with reference to Fig. 7. The pillar-type floating body erection system of the present invention is a system for erecting the pillar-type floating body 100 described so far, and therefore, we will avoid overlapping explanations with those described for the pillar-type floating body 100 and only explain the contents unique to the pillar-type floating body erection system of the present invention. In other words, the contents not described here are the same as those described in "2. Pillar-type floating body".

Figure 7 is a block diagram showing the main components of the columnar floating body erection system 300 of the present invention. As shown in this figure, the columnar floating body erection system 300 is configured to include a water injection means 310 and a first air on/off valve control means 320, and can also be configured to include a second air on/off valve control means 330. Below, we will explain each of the main elements that make up the columnar floating body erection system 300.

(Water injection means)
As described above, in order to inject water by the siphon effect, it is necessary to forcibly fill the communicating pipe 120 with water. The water injection means 310 is a means for forcibly filling the communicating pipe 120 with water, and is configured to include a water injection control means 311 and a water injection pump 312. The water injection pump 312 is a means for pumping water (seawater) into the communicating pipe 120, and a conventionally used submersible pump or the like can be used. On the other hand, the water injection control means 311 is a means for controlling the pumping of water by the water injection pump 312, and can be remotely operated by an operator. That is, the water injection control means 311 is installed at a location away from the water injection pump 312 (for example, on the sea), and when an operator operates the water injection control means 311, the water injection pump 312 installed underwater pumps water into the communicating pipe 120 or stops pumping water.

(Air valve control means)
The first air valve control means 320 is a means for controlling the first air valve 140 provided in a part of the communication pipe 120, and can be remotely operated by an operator. That is, the first air valve control means 320 is installed in a place away from the first air valve 140 (for example, on the sea), and the first air valve 140 is opened or closed by the operator operating the first air valve control means 320. When the first air valve 140 is opened, air in the pipe can be sent out while water (seawater) is flowing into the communication pipe 120, and when the first air valve 140 is closed, the inflow of air from the outside into the communication pipe 120 can be blocked.

The second air valve control means 330 is a means for controlling the second air valve 180, and can be remotely operated by an operator. That is, the second air valve control means 330 is installed in a location away from the second air valve 180 (e.g., at sea), and the operator operates the second air valve control means 330 to open or close the second air valve 180. When the second air valve 180 is in the open state, it can send air out from inside the valve to the outside, for example, when pouring water into the columnar body 110, and when it is in the closed state, it can block the flow of air in and out of the columnar body 110 with the outside.

4. Column-shaped floating body erection method Next, the column-shaped floating body erection method of the present invention will be described in detail with reference to Fig. 8. Note that the column-shaped floating body erection method of the present invention is a method for erecting the column-shaped floating body 100 described so far, and therefore, explanations that overlap with the contents described in the column-shaped floating body 100 and the column-shaped floating body erection system 300 will be avoided, and only the contents unique to the column-shaped floating body erection method of the present invention will be described. In other words, the contents not described here are the same as those described in "2. Column-shaped floating body" and "3. Column-shaped floating body erection system".

Figure 8 is a flow diagram showing the main steps of the pillar-shaped float erection method of the present invention. In this figure, the steps directly related to the pillar-shaped float erection method of the present invention are surrounded by a solid line frame, and the other steps are surrounded by a dashed line frame. As shown in this figure, first, the pillar-shaped float 100 is manufactured in a dry dock or the like (Step 401 in Figure 8). Then, aiming for a time when the environment is good, such as the tide level and tidal current, the pillar-shaped float 100 in a horizontally laid state is towed by a tugboat to a calm area selected in advance (Step 402 in Figure 8), and the pillar-shaped float 100 is temporarily moored at the site (Step 403 in Figure 8). At this time, the pillar-shaped float 100 is temporarily moored in a horizontally laid state, and floats on the sea surface in a state inclined so that a part of the bottom side of the pillar-shaped body 110 sinks below the seawater surface due to the effect of the weight 130.

When the columnar float 100 is temporarily moored in a calm area, the first air valve 140 is opened and the connecting pipe 120 is forcibly filled with water (Step 404 in FIG. 8). At this time, the first air valve control means 320 of the columnar float erection system 300 of the present invention is used to open the first air valve 140, and the water injection means 310 is used to pump water (seawater) into the connecting pipe 120.

When the communicating pipe 120 is filled with water, the water intake 121E is located in seawater (under seawater), and the water inlet 122E is located below the seawater level, water injection begins using the siphon principle (Step 405 in FIG. 8). More specifically, seawater flows in from the water intake 121E, through the communicating pipe 120, and is injected into the columnar body 110 from the water inlet 122E.

When water is poured into the columnar body 110 and the columnar floating body 100 finally reaches the planned height, the water injection by the siphon action is stopped (Step 406 in FIG. 8). For example, the first air valve 140 provided in the connecting pipe 120 may be opened to send air from the outside into the connecting pipe 120, thereby eliminating the siphon state and stopping the water injection. At this time, the first air valve 140 may be operated directly by the worker, or the first air valve 140 may be controlled by remote control by the operator. When remote control by the operator is used, the first air valve 140 may be opened using the first air valve control means 320 of the columnar floating body erection system 300 of the present invention.

When the columnar float 100 reaches the planned height, it is advisable to remove the water intake pipe 121 (Step 407 in FIG. 8). In particular, in the case where the water intake pipe 121 is arranged on the outside of the columnar body 110 (FIG. 2), it is desirable to remove the water intake pipe 121 because it is expected that the water intake pipe 121 may have an unexpected effect on the columnar float 100. The water intake pipe 121 can be removed by a diver, but if the water is considerably deep, it is advisable to use an underwater robot or an ROV (Remotely Operated Vehicle). In addition, if an opening remains in the columnar body 110 after the water intake pipe 121 is removed, the opening is sealed with a steel closing plate or the like (Step 408 in FIG. 8).

After the columnar float 100 is at the planned height, ballast material such as crushed stone is poured into the columnar body 110 and excess seawater is discharged from the columnar body 110 (Step 409 in Figure 8). After that, the tower, rotor, nacelle (Figure 9), etc. (hereinafter collectively referred to as the "upper body") are installed above the columnar float 100 to construct a completed body consisting of the upper body and the columnar float 100 (Step 410 in Figure 8), and temporarily moored in a calm area (Step 411 in Figure 8). Then, when the tide levels and currents are favorable, the completed structure is towed by a tugboat to the WF (Step 412 in Figure 8), where the completed columnar floating structure 100 is moored (Step 413 in Figure 8), and an undersea cable (Figure 9) is installed on the completed structure (Step 414 in Figure 8).

The columnar float, columnar float erection system, and columnar float erection method of the present invention can be particularly suitable for use in floating offshore wind power generation in sea areas 50 meters or deeper. The present invention makes it possible to install floating offshore wind power generation facilities at low cost and easily, which is expected to provide a more positive motivation for offshore wind power generation, and ultimately, considering the need to provide a stable supply of energy while reducing greenhouse gas emissions, the present invention can be said to be an invention that can be expected to not only be used industrially, but also to make a significant contribution to society.

100 Columnar type float of the present invention 110 Columnar body (of columnar type float) 120 Connecting pipe (of columnar type float) 121 Water intake pipe (of connecting pipe) 121E Water intake port (of connecting pipe) 122 Water injection pipe (of connecting pipe) 122E Water injection port (of connecting pipe) 123 Upper relay pipe (of connecting pipe) 124 Middle bypass pipe (of connecting pipe) 130 Weight (of columnar type float) 140 First air opening/closing valve (of columnar type float) 150 Check valve (of columnar type float) 160 Diameter reduction body (of columnar type float) 170 Connection body (of columnar type float) 180 Second air opening/closing valve (of columnar type float) 200 Direct type columnar type float of the present invention 210 Column body (of direct type column type float) 220 Direct water inlet (of direct type column type float) 230 Weight (of direct type column type float) 240 Opening control means (of direct type column type float) 241 Operating shaft (of opening control means) 242 Transmission shaft (of opening control means) 250 Diameter reduction body (of direct type column type float) 260 Connection body (of direct type column type float) 270 Second air opening/closing valve (of direct type column type float) 300 Column type float erection system of the present invention 310 Water injection means (of column type float erection system) 311 Water injection control means (of water injection means) 312 Water injection pump (of water injection means) 320 First air opening/closing valve control means (of column type float erection system) 330 Second air valve control means (for pillar-type floating body erection system)

Claims (10)

In the columnar floating structure that constitutes the floating offshore wind power generation facility,
A hollow columnar body having a weight attached to the bottom thereof;
A communication pipe provided with a water intake port and a water inlet;
an air valve for controlling the inflow and outflow of air into the communication pipe,
The water intake is disposed on the outside of the columnar body;
The water inlet is disposed inside the columnar body and adjacent to the bottom,
The columnar body floats on the sea surface in a slanted, sideways state such that a portion of the bottom side is submerged below the seawater level,
The air valve is provided so as to be located in an air space inside the columnar body when a predetermined amount of seawater is poured into the columnar body to reach a planned height,
When the water intake is located in seawater, the inside of the communication pipe is filled with water, the air valve is closed, and the water inlet is located below the seawater level, seawater flowing in from the water intake is injected into the columnar body through the water inlet by a siphon effect.
A column-shaped floating structure characterized by: the communicating pipe includes a water intake pipe provided with the water intake port, a water injection pipe provided with the water injection port, and an upper relay pipe connecting the water intake pipe and the water injection pipe;
The water intake pipe is parallel or approximately parallel to the column axis direction of the columnar body, and is disposed outside the columnar body;
The seawater flowing in from the water intake rises in the water intake pipe, passes through the upper relay pipe, and flows down in the water injection pipe.
2. The pillar-type floating structure according to claim 1 . In the columnar floating structure that constitutes the floating offshore wind power generation facility,
A hollow columnar body having a weight attached to the bottom thereof;
A communication pipe provided with a water intake port and a water inlet,
The water intake is disposed on the outside of the columnar body;
The water inlet is disposed inside the columnar body and adjacent to the bottom,
the communicating pipe includes a water intake pipe provided with the water intake port, a water injection pipe provided with the water injection port, and an upper relay pipe connecting the water intake pipe and the water injection pipe;
The water intake pipe is parallel or approximately parallel to the column axis direction of the columnar body, and is disposed inside the columnar body;
A part of the water intake pipe on the water intake port side is formed as a curved pipe, and the curved pipe penetrates the columnar body, so that the water intake port is disposed outside the columnar body;
The columnar body floats on the sea surface in a slanted, sideways state such that a portion of the bottom side is submerged below the seawater level,
When the water intake is located in seawater, the inside of the communicating pipe is filled with water, and the water inlet is located below the seawater level, seawater flowing in from the water intake is injected into the columnar body through the water inlet by a siphon effect,
The seawater flowing in from the water intake rises in the water intake pipe, passes through the upper relay pipe, and flows down in the water injection pipe.
A column-shaped floating structure characterized by: An air valve for controlling the inflow and outflow of air into the communication pipe is further provided,
The air valve is provided so as to be located in an air space inside the columnar body when a predetermined amount of seawater is poured into the columnar body to reach a planned height,
When the air valve is closed, seawater flowing in from the water intake port is injected into the columnar body through the water inlet by a siphon effect.
4. The pillar-type floating structure according to claim 3 . The communication pipe further includes a middle bypass pipe connecting the water intake pipe and the water injection pipe,
the middle bypass pipe is disposed so as to be lower than the upper relay pipe when a predetermined amount of seawater is poured and the columnar body is placed in an upright state;
When the height of the upper relay pipe from the seawater level exceeds the limit height for siphon action, the seawater rising in the water intake pipe flows down in the water injection pipe via the middle bypass pipe.
5. The pillar-type floating structure according to claim 2, wherein the pillar-type floating structure is a floating structure. A check valve is provided in the intake pipe near the intake port,
The check valve can prevent backflow of seawater from the water intake pipe to the water intake port.
The pillar-type floating structure according to any one of claims 2 to 5 . The water intake is arranged so as to be within the seawater even when a predetermined amount of seawater is poured and the columnar body is in an upright state.
7. The pillar-type floating structure according to claim 1, A system for erecting columnar floats that constitute a floating offshore wind power generation facility in an upright position in seawater,
The columnar floating body includes a hollow columnar body having a weight installed at its bottom, a communicating pipe provided with a water intake port disposed on the outside of the columnar body and a water inlet port disposed on the inside of the columnar body near the bottom, and an air valve for controlling the inflow and outflow of air into the communicating pipe,
The columnar body floating on the sea surface in a sideways state is inclined so that a part of the bottom side is submerged below the seawater level, the water intake is located in the seawater, and the water injection port is located below the seawater level,
an air valve control means for controlling the air valve by remote control by an operator;
and a water injection means for injecting seawater into the communication pipe by remote control by an operator.
With the columnar body laid on its side, an operator operates the water injection means to inject seawater into the communicating pipe while removing air from the communicating pipe whose air valve is opened.
When the operator closes the air valve using the air valve control means while the communication pipe is filled with water, seawater flowing in from the water intake port is injected into the columnar body through the water injection port by a siphon effect,
When an operator opens the air valve by the air valve control means, the injection of water into the columnar body by the siphon action is stopped.
A column-type floating structure erection system. A method for erecting a columnar floating body constituting a floating offshore wind power generation facility so that the floating body is in an upright position in seawater, comprising the steps of:
The columnar floating body includes a hollow columnar body having a weight installed at its bottom, a communicating pipe provided with a water intake port disposed on the outside of the columnar body and a water inlet port disposed inside the columnar body near the bottom, and an air valve for controlling the inflow and outflow of air into the communicating pipe,
The columnar body floating on the sea surface in a sideways state is inclined so that a part of the bottom side is submerged below the seawater level, the water intake is located in the seawater, and the water injection port is located below the seawater level,
a pipe water injection process in which, with the columnar body laid on its side, the air valve is opened to inject seawater into the communicating pipe while removing air from the communicating pipe;
a water injection process in which the inside of the connecting pipe is filled with water and the air valve is closed to utilize a siphon effect, thereby injecting seawater flowing in from the water intake into the columnar main body through the water injection port;
and a water injection stopping step of opening the air valve when the upright columnar body is placed at a planned height by the water injection step.
In the pipe water injection step, the air valve is opened to inject seawater into the communicating pipe while removing air from the communicating pipe, and when the communicating pipe is filled with water, the air valve is closed.
In the water injection stopping step, the air valve is opened to send air into the communication pipe, thereby stopping the injection of water into the columnar body by a siphon effect;
By pouring a predetermined amount of seawater into the columnar body, the columnar body is raised from a lying state to an upright state.
A method for erecting a column-shaped floating structure. the communicating pipe includes a water intake pipe provided with the water intake port, a water injection pipe provided with the water injection port, and an upper relay pipe connecting the water intake pipe and the water injection pipe;
The water intake pipe is parallel or approximately parallel to the column axis direction of the columnar body, and is disposed outside the columnar body;
a water intake pipe removal process for removing the water intake pipe after the upright columnar body is arranged at a planned height by the water injection process;
The opening of the columnar body generated after the intake pipe is removed is sealed with a sealing material.
The method for erecting a pillar-shaped floating structure according to claim 9 .

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