Discharge System

Abstract

To efficiently pump up sea water from a region deeper than a surface layer by efficiently using a flow of the sea water.SOLUTION: A water discharge system includes a floating body 21, an intake pipe 3, and a water turbine 22 in a vertical axis method. The water turbine 22 is attached to the floating body 21 and positioned under the sea level. The water turbine 22 is rotated only in one of periphery directions with a central axis J1 facing a vertical direction as center. The water turbine 22 is provided with a water turbine channel 223. The water turbine channel 223 is connected to the intake pipe 3. The water turbine channel 223 includes a discharge port 224 on an end unit at the outside in a radial direction. Sea water in the water turbine channel 223 is discharged from the discharge port 224 by centrifugal force and the sea water near the water intake port is conducted into the water wheel channel 223 through the intake pipe 3 as well by having the water turbine 22 rotated by a flow of the sea water in the water discharge system. Thus, the sea water from a region deeper than a surface layer is capable of being efficiently pumped up by efficient use of the flow of the sea water.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a discharge system. [Background technology]

[0002] Conventionally, ocean fertilization devices have been proposed that pump seawater rich in nutrients from deeper areas and spread it to the surface, with the aim of eutrophicating surface seawater and creating new fishing grounds.

[0003] For example, the deep-sea water pumping and diffusion device in Patent Document 1 includes a submersible float that floats below the surface of the euphotic zone and an upwelling pipe that extends from the submersible float to the seabed. In this pumping and diffusion device, an impeller installed inside the submersible float is rotated by a steam turbine device to pump up deep-sea water, suck in surface water, and discharge a mixture of deep and surface water.

[0004] The ocean fertilization device in Patent Document 2 comprises a float moored to the sea surface and a deep-sea water intake pipe extending from the float to the seabed. In this ocean fertilization device, a watertight electric motor rotates an impeller installed inside the float to pump up deep-sea water, suck in surface water, and discharge mixed water of deep and surface water. The electric motor is driven by electricity obtained by generating electricity using an internal combustion engine or the like installed inside the float.

[0005] The deep-sea water pumping device of Patent Document 3 includes a deep-sea water pumping unit suspended in the sea from a float, a hose extending from the deep-sea water pumping unit to the seabed, and an outer screw attached to the outside of the deep-sea water pumping unit. In this deep-sea water pumping device, the outer screw is rotated by the tidal current, which rotates an inner screw installed inside the deep-sea water pumping unit, thereby pumping up deep sea water. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-27748 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-370690 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-90619 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, in the pumping and diffusion device of Patent Document 1, it is proposed to generate steam for the steam turbine device that rotates the impeller by utilizing energy due to the temperature difference between surface water and the pumped-up deep water (so-called ocean thermal energy). Also, in the ocean fertilization device of Patent Document 2, it is proposed to obtain electricity for the electric motor that rotates the impeller by ocean thermal energy conversion, wind power generation, etc.

[0008] However, in order to utilize ocean thermal energy, it is first necessary to pump up deep-sea water, which requires an internal combustion engine to drive a steam turbine device that rotates an impeller and an electric motor. Furthermore, when using wind power generation, wind power must be converted into electricity, which must then be converted into kinetic energy that rotates an impeller, resulting in low energy utilization efficiency and making it difficult to ensure a stable energy supply. Therefore, an internal combustion engine to drive a steam turbine device that rotates an impeller and an electric motor is still required.

[0009] On the other hand, Patent Document 3 describes that deep-sea water can be pumped up without using an electric pump by using tidal currents to rotate the outer and inner screws. However, the outer screw is a horizontal-axis propeller, and when the tidal currents around the propeller reverse due to tides, the propeller also rotates in the opposite direction. Therefore, the propeller has poor ability to follow changes in the water flow around the propeller, which may result in low pumping efficiency of deep-sea water. Furthermore, because the water flow around the propeller due to waves (i.e., the movement of particles that make up the waves (orbital motion)) reverses between the crests and troughs of the waves, it is difficult to use the wave-driven seawater flow to pump up deep-sea water with this propeller. This also may result in low pumping efficiency of deep-sea water.

[0010] The present invention has been made in consideration of the above-mentioned problems, and has as its object to efficiently pump up seawater in an area deeper than the surface layer by efficiently utilizing the flow of seawater. [Means for solving the problem]

[0011] The invention described in claim 1 is a discharge system comprising a floating body moored by mooring lines and floating on the sea surface, a water intake pipe extending downward from the floating body and having a water intake at its lower end, and a vertical axis water turbine attached to the floating body, located below the sea surface, and rotating in only one circumferential direction around a central axis facing up and down, wherein the water turbine has a water turbine channel connected to the water intake pipe and having an outlet at its radially outer end, and when the water turbine rotates due to the flow of seawater, seawater in the water turbine channel is discharged from the outlet by centrifugal force, and seawater near the water intake is guided into the water turbine channel via the water intake pipe.

[0012] The invention described in claim 2 is the discharge system described in claim 1, wherein the floating body is columnar with the central axis as the center, and the water turbine is provided on the side of the floating body.

[0013] The invention described in claim 3 is a discharge system described in claim 2, wherein the water turbine is a propeller-type water turbine having a plurality of blades that each protrude radially outward from the side of the floating body and are arranged circumferentially.

[0014] A fourth aspect of the present invention is the discharge system according to the third aspect, wherein each of the plurality of blades has a radially central portion curved to be convex toward the rotation direction of the water turbine.

[0015] The invention described in claim 5 is a discharge system described in claim 3 or 4, wherein the turbine flow path is provided inside each of the plurality of blades, and the discharge outlet is provided on the end edge of each of the plurality of blades.

[0016] The invention described in claim 6 is a discharge system described in any one of claims 1 to 5, wherein at least the portion of the floating body above the sea surface is independent of the rotation of the water turbine.

[0017] The invention described in claim 7 is the discharge system described in claim 6, wherein the entire floating body is independent of the rotation of the water turbine.

[0018] The invention described in claim 8 is a discharge system described in any one of claims 1 to 7, further comprising a power generation device that generates electricity by utilizing the flow of seawater around the floating body, and a pump that is driven by the electricity generated by the power generation device and assists in the upward movement of seawater in the water intake pipe. [Effects of the Invention]

[0019] In the present invention, the flow of seawater can be efficiently utilized to efficiently pump up seawater from areas deeper than the surface layer. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a side view of a discharge system according to one embodiment. [Figure 2]FIG. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 10 is a plan view of a floating body equipped with another water turbine. DETAILED DESCRIPTION OF THE INVENTION

[0021] Fig. 1 is a side view showing the configuration of a release system 1 according to one embodiment of the present invention. The release system 1 is a floating ocean fertilization device that is moored in an area of ​​the sea such as a fishing ground and that uses deep seawater (so-called deep ocean water) that is rich in nutrients from an area deeper than the surface layer to eutrophicate the surface layer. The release system 1 can be used as a floating fish reef with an ocean fertilization function.

[0022] The discharge system 1 includes a floating body 2 and a water intake pipe 3. The floating body 2 is a structure floating on the sea surface 91 while spaced above the seabed 92. The floating body 2 is moored to the seabed 92 by a mooring line 41. In the example shown in FIG. 1 , the floating body 2 is a substantially columnar structure extending vertically through the sea surface 91, and is connected via the mooring line 41 to a mooring base 42 installed on the seabed 92.

[0023] The mooring base 42 is, for example, a sinker (i.e., a weight) or an anchor (i.e., an anchor with holding power) that is sunk into the seabed 92. Alternatively, the mooring base 42 may be a fixed structure that is pre-installed on the seabed 92. The mooring base 42 does not necessarily have to be directly fixed to the seabed 92, but may be an object that is indirectly fixed to the seabed 92 in the sea via, for example, another structure fixed to the seabed 92.

[0024] The mooring line 41 is a substantially linear member that connects the floating body 2 and the mooring base 42. The mooring line 41 is, for example, a mooring rope, a mooring chain, or a mooring chain connected to a mooring rope. The mooring rope is, for example, a rope made of synthetic fiber or metal including wire. In FIG. 1, the mooring line 41 is shown as a line for convenience of illustration. In the example shown in FIG. 1, the floating body 2 is moored at one point to the mooring base 42 by one mooring line 41 connected to the lower end of the floating body 2. Note that the floating body 2 may be moored at multiple points.

[0025] The intake pipe 3 is a substantially cylindrical member that extends downward from the lower end of the floating body 2 toward the seabed 92, and is also called a riser pipe. A water intake port 31 that takes in deep seawater is provided at the lower end of the intake pipe 3. The intake pipe 3 is mainly made of steel. The vertical length of the intake pipe 3 is, for example, 100 m to 1000 m. The diameter (i.e., outer diameter) of the intake pipe 3 is, for example, 0.25 m to 1.5 m. The material, length, and diameter of the intake pipe 3 may be changed in various ways.

[0026] FIG. 2 is a side view showing the float 2 of the discharge system 1. FIG. 3 is a plan view of the float 2. FIG. 4 is a cross-sectional view of the float 2 taken at position IV-IV in FIG. 2. FIG. 5 is a longitudinal cross-sectional view of the float 2 taken at position VV in FIG. 4. A portion of the water intake pipe 3 is also shown in FIGS. 2 and 5. In addition, in FIGS. 4 and 5, to make the drawings easier to understand, only the seawater inside the float 2 is marked with diagonal lines, and the cross section of the float 2 is not marked with diagonal lines.

[0027] The float 2 comprises a float main body 21 and a water turbine 22. The float main body 21 is a substantially columnar structure extending in the vertical direction through the sea surface 91 (see FIG. 1). In the example shown in FIG. 2, the float main body 21 is a substantially cylindrical structure extending in the vertical direction around a central axis J1. The central axis J1 is an imaginary straight line extending in the vertical direction. The float main body 21 is mainly formed of steel. The vertical length of the float main body 21 is, for example, 4 m to 10 m. The diameter of the float main body 21 is, for example, 3 m to 7 m. The vertical length of the portion of the float main body 21 protruding above the sea surface 91 (i.e., freeboard) is, for example, 0.5 m to 4 m. The size and shape of the float main body 21 are not limited to the above example and may be modified in various ways.

[0028] The above-mentioned water intake pipe 3 is attached, for example, to approximately the center in the radial direction (hereinafter also simply referred to as the "radial direction") about the central axis J1 at the lower end of the floating body main body 21. Also, the mooring line 41 (see FIG. 1) is connected, for example, to a part of the circumferential direction (hereinafter also simply referred to as the "circumferential direction") about the central axis J1 at the radial outer end of the lower end of the floating body main body 21.

[0029] The water turbine 22 is attached to the floating body main body 21 below the sea surface 91. In the example shown in FIG. 2, the water turbine 22 is provided on the side of the floating body main body 21 (i.e., the approximately cylindrical side surface on the radially outer side) above the water intake pipe 3 and the mooring line 41 (see FIG. 1). The water turbine 22 is rotatable along the side of the floating body main body 21 around a central axis J1 facing in the up-down direction. In other words, the water turbine 22 is a vertical axis type water turbine rotatably attached to the floating body main body 21. The water turbine 22 is mainly made of steel.

[0030] The water turbine 22 rotates in only one circumferential direction due to the force acting from the seawater flowing around the floating body 21. In the example shown in FIG. 3, the water turbine 22 rotates only clockwise in a plan view, and does not rotate counterclockwise, regardless of the direction of the seawater flowing around the floating body 21. The flow of seawater around the floating body 21 includes "ocean currents" such as the Kuroshio Current, which always flow in approximately the same direction, "tidal currents (also called tidal currents)" that occur with the ebb and flow of the tide, "wind-driven currents" that occur due to wind blowing on the sea, and seawater flow caused by waves. The direction of tidal currents changes to approximately the opposite direction, usually twice a day, due to repeated low and high tides. The direction of wind-driven currents changes depending on the direction of the wind blowing on the sea. The wave-driven seawater flow (i.e., the movement of particles that make up the wave (orbital motion)) is opposite when the floating body 2 is located at a wave crest and when it is located at a wave trough. As described above, the water turbine 22 is of the vertical axis type, and therefore continues to rotate in the same direction by efficiently utilizing the energy of the seawater flow, regardless of changes in the direction of the seawater flow around the floating body main body 21.

[0031] The water turbine 22 is a vertical-axis propeller-type water turbine including a boss portion 221 and multiple blades 222. The boss portion 221 is a substantially cylindrical portion extending substantially vertically around a central axis J1 and is rotatably attached to the side surface of the floating body main body 21. The multiple blades 222 are connected to the outer surface of the boss portion 221 and extend radially outward from the outer surface. In other words, the multiple blades 222 of the water turbine 22 each protrude radially outward from the side surface of the floating body main body 21. Each of the multiple blades 222 is a substantially plate-shaped member extending substantially parallel in the vertical direction. The multiple blades 222 are arranged circumferentially at substantially equal angular intervals. In the example shown in FIG. 3, four blades 222 are arranged circumferentially at approximately 90° intervals. The number of the multiple blades 222 is not limited to four and may be changed as appropriate. Furthermore, each blade 222 does not necessarily need to extend substantially parallel to the vertical direction, but may extend at an angle relative to the vertical direction.

[0032] The radial size of each blade 222 (i.e., the radial distance between the connection portion of blade 222 with boss portion 221 and the radial outer end of blade 222 in plan view) is, for example, 1 m to 2 m. The vertical size of each blade 222 (i.e., the height of blade 222) is, for example, 2 m to 3 m.

[0033] It is preferable that the connection portion of each blade 222 with the boss portion 221 be located forward in the rotation direction (i.e., clockwise direction) of the water turbine 22 in plan view relative to the edge of each blade 222 (i.e., the free edge opposite the connection portion). It is also preferable that each blade 222 be curved in a substantially arc shape so that the radial center portion of each blade 222 is convex in the rotation direction of the water turbine 22 in plan view. In other words, it is preferable that the connection portion of each blade 222 with the boss portion 221 and the radial center portion of each blade 222 be located forward in the rotation direction of the water turbine 22 relative to the straight line connecting the edge of each blade 222 and the central axis J1 in plan view.

[0034] In the water turbine 22, the size and shape of the plurality of blades 222 are preferably approximately the same. This simplifies the manufacture of the water turbine 22. Note that the size and shape of each blade 222 are not limited to the above example and may be changed in various ways. Furthermore, the size and / or shape of the plurality of blades 222 do not necessarily have to be the same and may be different.

[0035] The upper end of the water turbine 22 is located, for example, 3 to 5 m below the sea surface 91. Preferably, at least a portion of the floating body 21 above the sea surface 91 is independent of the rotation of the water turbine 22 and does not follow the rotation of the water turbine 22 caused by the flow of seawater acting on the water turbine 22. This allows a vessel or the like approaching the floating body 2 to easily come alongside the upper part of the floating body 21, which is barely rotating, without coming into contact with the rotating water turbine 22. More preferably, the entire floating body 21 is independent of the rotation of the water turbine 22 and does not follow the rotation of the water turbine 22 caused by the flow of seawater acting on the water turbine 22. This also makes the mooring line 41 and the water intake pipe 3 connected to the lower part of the floating body 21 independent of the rotation of the water turbine 22. This facilitates mooring of the floating body 2 to the seabed 92 and simplifies the connection structure between the floating body 21 and the water intake pipe 3.

[0036] In the float 2 illustrated in FIG. 5, a substantially cylindrical recess 211 (hereinafter also referred to as the "main body recess 211") extending substantially in the vertical direction around the central axis J1 is provided on the side surface of the float main body 21. The diameter of the side surface of the float main body 21 in the region where the main body recess 211 is provided (hereinafter also referred to as the "recess side surface 212") is smaller than the diameter of the side surface of the float main body 21 above the main body recess 211 and the diameter of the side surface of the float main body 21 below the main body recess 211. A boss portion 221 is fitted into the main body recess 211. The diameter of the inner surface of the boss portion 221 is larger than the diameter of the recess side surface 212. Therefore, a substantially cylindrical gap (hereinafter also referred to as the "outer buffer space 214") extending substantially in the vertical direction around the central axis J1 is formed between the inner surface of the boss portion 221 and the recess side surface 212 of the float main body 21.

[0037] The diameter of the inner surface of the boss portion 221 is smaller than the diameter of the side surface of the portion of the floating body main body 21 above the main body recess 211 and the diameter of the side surface of the portion of the floating body main body 21 below the main body recess 211. The upper end surface and the lower end surface of the boss portion 221 are respectively opposed to the upper surface and the lower surface of the main body recess 211 of the floating body main body 21 in the up-down direction. Bearings 213 are provided between the upper end surface of the boss portion 221 and the upper surface of the main body recess 211, and between the lower end surface of the boss portion 221 and the lower surface of the main body recess 211, and the water turbine 22 is rotatably supported on the floating body main body 21 via the bearings 213. The gap between the upper end surface of the boss portion 221 and the upper surface of the main body recess 211, and the gap between the lower end surface of the boss portion 221 and the lower surface of the main body recess 211 are watertight sealed. As a result, the outer buffer space 214 is isolated from the space around the boss portion 221 and the floating body main body 21, and the intrusion of surface seawater into the outer buffer space 214 is prevented.

[0038] 4 and 5, the outer buffer space 214 is connected to the inner buffer space 216 via a plurality of connecting channels 215 extending radially inside the floating body main body 21. The inner buffer space 216 is a space located radially inward of the outer buffer space 214 and the plurality of connecting channels 215. The inner buffer space 216 is, for example, a substantially cylindrical space extending substantially vertically about the central axis J1, and is located above the water intake pipe 3. The lower end of the inner buffer space 216 is connected to the upper end of the water intake pipe 3, and the inner buffer space 216, the plurality of connecting channels 215, and the outer buffer space 214 are filled with deep seawater taken in from the water intake port 31 (see FIG. 1) of the water intake pipe 3.

[0039] A turbine flow path 223 is provided inside each blade 222 of the turbine 22. The turbine flow path 223 extends along the front and rear side surfaces of the blade 222 in the rotational direction from the end edge (i.e., the free end edge) of the blade 222 to the connection part with the boss part 221 of the blade 222. The turbine flow path 223 extends, for example, from the upper end to the lower end of the blade 222. The turbine flow path 223 penetrates the boss part 221 at its radially inner end and connects to the outer buffer space 214. The turbine flow path 223 is connected to the intake pipe 3 via the outer buffer space 214, multiple connecting flow paths 215, and the inner buffer space 216, and the turbine flow path 223 is also filled with deep seawater taken in from the intake port 31 of the intake pipe 3 (see FIG. 1 ).

[0040] The turbine channel 223 opens at the edge of the blade 222 toward the outside of the blade 222 (i.e., toward the outside of the floating body 2). In the following description, the opening provided at the edge of the blade 222 is also referred to as the "discharge port 224." The discharge port 224 is located at the radially outer end of the turbine channel 223, and is also located at the radially outer end of the turbine 22. The discharge port 224 is, for example, a substantially slit-shaped opening extending in the up-down direction from the upper end to the lower end of the edge of the blade 222. The shape of the discharge port 224 may be changed as appropriate. For example, the edge of the blade 222 may be provided with multiple circular or other discharge ports arranged in the up-down direction. The turbine channel 223 is not open on the surface of the blade 222 except for the discharge port 224 (for example, at the upper end or lower end of the blade 222).

[0041] In the discharge system 1, when the water turbine 22 rotates due to the flow of seawater around the floating body main body 21, deep seawater in the water turbine channel 223 of each blade 222 is discharged radially outward from the discharge port 224 by centrifugal force. In parallel with the discharge of deep seawater from each discharge port 224, deep seawater flows from the outer buffer space 214 into each water turbine channel 223, and deep seawater flows into the outer buffer space 214 from the inner buffer space 216 via multiple connecting channels 215. Furthermore, deep seawater taken in from the water intake 31 flows into the inner buffer space 216 via the water intake pipe 3. In other words, when the water turbine 22 rotates on the floating body 2, deep seawater is discharged from each discharge port 224, and deep seawater near the water intake 31 is pumped up via the water intake pipe 3 and led into the water turbine channel 223.

[0042] In the discharge system 1 of this embodiment, it is preferable that a pump for pumping up deep seawater through the intake pipe 3 and a power generation device (e.g., a generator such as a diesel engine that uses fuel oil) for driving the pump are not provided.

[0043] In the discharge system 1, deep seawater (i.e., seawater rich in nutrients) radially discharged from the outlets 224 of the multiple blades 222 around the floating body 2 is dispersed over a wide area in the surface layer as a density current. This causes the surface layer to become eutrophic, and new fishing grounds are formed. In the above explanation, the seawater discharged from each outlet 224 is only deep seawater pumped up by the intake pipe 3, but this is not limited to this. For example, deep seawater pumped up by the intake pipe 3 and surface seawater taken in from around the floating body main body 21 may be mixed inside the floating body main body 21 (e.g., the internal buffer space 216) to form mixed seawater, and the mixed seawater may be discharged from each outlet 224.

[0044] In the discharge system 1, the turbine channel 223 does not necessarily have to be provided inside the blades 222 of the turbine 22. Furthermore, the vertical-axis turbine 22 provided on the floating body 2 is not limited to a propeller type, and may have other structures, such as a cross-flow type, a Saponius type, a Darrieus type, or a gyromill type. For example, on the upper surface of a substantially cylindrical cross-flow turbine extending substantially vertically about the central axis J1, a plurality of pipelines (e.g., substantially circular tubular metal pipes) extending radially outward from the central axis J1 may be provided, and each of the plurality of pipelines may serve as the turbine channel 223. In this case, the radially inner end of each pipeline is connected to the intake pipe 3 via the above-mentioned inner buffer space 216 or the like, and the radially outer end of each pipeline serves as the discharge port 224 provided at the radially outer end of the turbine 22.

[0045] As described above, the discharge system 1 comprises the floating body 21, the water intake pipe 3, and the vertical-axis water turbine 22. The floating body 21 is moored by a mooring line 41 and floats on the sea surface 91. The water intake pipe 3 extends downward from the floating body 21. The water intake pipe 3 has a water intake port 31 at its lower end. The water turbine 22 is attached to the floating body 21 and located below the sea surface 91. The water turbine 22 rotates in only one circumferential direction around a central axis J1 facing up and down. The water turbine 22 is provided with a water turbine channel 223. The water turbine channel 223 is connected to the water intake pipe 3. The water turbine channel 223 has a discharge port 224 at its radially outer end. In the discharge system 1, the flow of seawater causes the turbine 22 to rotate, causing the seawater in the turbine flow path 223 to be discharged from the discharge port 224 by centrifugal force, and the seawater near the intake port 31 to be guided into the turbine flow path 223 via the intake pipe 3.

[0046] In this way, the discharge system 1 is provided with a vertical axis water turbine 22 that rotates in only one circumferential direction by utilizing the flow of seawater, regardless of the direction of the flow of seawater around the floating body main body 21. This allows the water turbine 22 to rotate by efficiently utilizing the flow of seawater even if the direction of the flow of seawater changes. Specifically, the discharge system 1 can efficiently utilize not only ocean currents that flow in approximately the same direction, but also tidal currents, wind currents, and seawater flows caused by waves, whose flow direction changes, to rotate the water turbine 22.

[0047] Furthermore, in the discharge system 1, the centrifugal force generated by the rotation of the water turbine 22 can be used to discharge seawater in the turbine channel 223 around the floating body 2, and nutrient-rich seawater (i.e., deep seawater) in a region deeper than the surface can be efficiently pumped up and supplied to the turbine channel 223. Therefore, a pump for pumping seawater through the intake pipe 3, a power generation device for driving the pump, and the like can be omitted from the discharge system 1, thereby simplifying the configuration and maintenance of the discharge system 1. Furthermore, even if the pump and power generation device are provided, the amount of fuel oil and the like used to drive the power generation device can be reduced. As a result, the costs required for manufacturing and / or operating the discharge system 1 can be reduced.

[0048] As described above, the floating body main body 21 is preferably columnar about the central axis J1, and the water turbine 22 is provided on the side of the floating body main body 21. This allows the water turbine 22 to be located near the sea surface 91 while preventing the float 2 from becoming too large. As a result, nutrient-rich deep seawater can be dispersed into the surrounding area from the outlet 224 of the water turbine 22 located near the sea surface 91, thereby effectively realizing eutrophication of the surface layer.

[0049] As described above, the water turbine 22 is preferably a propeller-type water turbine having a plurality of blades 222 arranged circumferentially and each protruding radially outward from the side surface of the floating body 21. This allows the flow of seawater around the floating body 21 to be efficiently used to rotate the water turbine 22. As a result, deep seawater can be efficiently pumped up.

[0050] As described above, it is preferable that each of the plurality of blades 222 is curved so that the radial center portion is convex toward the rotation direction of the water turbine 22. This allows the flow of seawater around the floating body main body 21 to be more efficiently used to rotate the water turbine 22. As a result, deep seawater can be pumped up more efficiently.

[0051] As described above, the turbine flow path 223 is preferably provided inside each of the plurality of blades 222. The discharge port 224 is preferably provided on the edge of each of the plurality of blades 222. This allows the turbine 22 to be made smaller than when the turbine flow path 223 is provided outside the blades 222. As a result, the floating body 2 and the discharge system 1 can be made smaller.

[0052] As described above, in the discharge system 1, it is preferable that at least the portion of the floating body main body 21 above the sea surface 91 is independent of the rotation of the water turbine 22. This makes it easier for ships and the like to come alongside the floating body main body 21 and for workers to board the floating body main body 21. Furthermore, in the discharge system 1, it is even more preferable that the entire floating body main body 21 is independent of the rotation of the water turbine 22. This makes it easier to moor the floating body 2 to the seabed 92 as described above, and also simplifies the connection structure between the floating body main body 21 and the water intake pipe 3, etc.

[0053] In the discharge system 1, as shown in FIG. 6, a pump 51 may be provided inside the floating body main body 21, and the pumping up of deep seawater by the rotation of the water turbine 22 (i.e., the upward movement of seawater in the water intake pipe 3) may be assisted by the pump 51. The pump 51 may be, for example, an axial flow pump, and is disposed in the internal buffer space 216. The pump 51 is not used under normal conditions (i.e., when the pumping flow rate of deep seawater by the rotation of the water turbine 22 is equal to or greater than a predetermined flow rate), but is driven to assist the pumping up of deep seawater when the flow of seawater around the floating body 21 weakens and the pumping flow rate becomes insufficient. The type and arrangement of the pump 51 are not particularly limited and may be selected as appropriate.

[0054] The pump 51 is driven by electricity generated by a power generation device 52 provided in the floating body main body 21. In the example shown in FIG. 6 , the power generation device 52 is arranged inside the floating body main body 21 and is mechanically connected to the water turbine 22 via gears, shafts, etc. (not shown). The power generation device 52 converts the rotational energy of the water turbine 22, which is generated by the flow of seawater around the floating body main body 21, into electrical energy. In other words, the power generation device 52 generates electricity by utilizing the flow of seawater around the floating body main body 21. The electricity generated by the power generation device 52 is stored in a storage battery 53 arranged inside the floating body main body 21. When the pumping flow rate of deep seawater due to the rotation of the water turbine 22 falls below the predetermined flow rate, the electricity stored in the storage battery 53 is supplied to the pump 51, which drives the pump 51 and assists in pumping up the deep seawater.

[0055] As described above, it is preferable that the discharge system 1 further includes a power generation device 52 that generates electricity using the flow of seawater around the floating body 21, and a pump 51 that is driven by the electricity generated by the power generation device 52 and assists in the upward movement of seawater in the water intake pipe 3. This makes it possible to suppress or prevent a shortage in the pumping flow rate of deep seawater even when the flow of seawater around the floating body 21 weakens. It is also preferable that the power generation device 52 generates electricity using the rotation of the water turbine 22. This simplifies the configuration related to the power generation.

[0056] It is preferable that power generation by the power generation device 52 is performed only when the pumping flow rate of deep seawater due to the rotation of the water turbine 22 is equal to or greater than a predetermined threshold value that is greater than the predetermined flow rate, and is stopped when the flow rate is less than the threshold value. As a result, when the seawater flow around the floating body main body 21 is relatively weak, the seawater flow can be used only for pumping deep seawater, not for power generation. As a result, a shortage of the pumping flow rate of deep seawater can be effectively prevented.

[0057] The power generation device 52 does not necessarily have to generate power using the rotation of the water turbine 22. For example, a power-generating water turbine other than the water turbine 22 may be attached to the floating body 21, and the rotational energy of the power-generating water turbine due to the flow of seawater around the floating body 21 may be converted into electrical energy by the power generation device 52. Furthermore, the power generation device 52 may generate power using other renewable energy instead of or in addition to the flow of seawater around the floating body 21. Examples of such other renewable energy that can be used include solar power, wind power, and / or the temperature difference between surface seawater and deep seawater (so-called ocean temperature difference). Even in these cases, a shortage in the pumping flow rate of deep seawater can be suppressed or prevented in a manner similar to that described above.

[0058] The discharge system 1 described above can be modified in various ways.

[0059] For example, in the water turbine 22, it is not necessary to provide the turbine flow path 223 and the discharge port 224 in all of the blades 222, and the turbine flow path 223 and the discharge port 224 may be provided in only some of the multiple blades 222. Furthermore, the discharge port 224 does not necessarily have to be provided at the edge of the blade 222, as long as it is located at the radially outer end of the turbine flow path 223 provided inside the blade 222, and may be provided in a portion other than the edge of the blade 222 (for example, a portion radially inward from the edge on the side surface on the front and / or rear side in the rotation direction of the blade 222). In the water turbine 22, the turbine flow path 223 does not necessarily have to be provided inside the blade 222, and may be provided outside the blade 222. For example, a conduit (for example, a substantially cylindrical metal pipe) extending along the upper edge of the blade 222 may be attached to the upper end of the blade 222, and the conduit may be used as the turbine flow path 223. In this case, the radially outer end opening of the conduit becomes the discharge port 224.

[0060] The water turbine 22 does not necessarily have to be attached to the side of the floating body 21, but may be attached to another part of the floating body 21. For example, the water turbine 22 may be attached to the lower end of the floating body 21 and disposed below the floating body 21 so as to surround the water intake pipe 3.

[0061] The shape and size of the floating body 21 are not limited to the above example and may be changed in various ways. Furthermore, the floating body 21 does not necessarily need to be independent of the rotation of the water turbine 22. For example, a part of the floating body 21 (for example, a part below the sea surface 91) or the entire floating body 21 may be configured to rotate together with the water turbine 22, which rotates due to the flow of seawater around the floating body 21.

[0062] The shape of the water turbine 22 is not limited to the above example and may be modified in various ways. For example, as shown in FIG. 7, a propeller-type water turbine 22a having blades 222a with a different shape from the blades 222 may be attached to the side of the floating body main body 21 instead of the water turbine 22. In the water turbine 22a, multiple blades 222a extend radially outward from the outer surface of a boss portion 221 with substantially the same shape as in the above example. In other words, the multiple blades 222a each protrude radially outward from the side of the floating body main body 21. In the example shown in FIG. 7, four blades 222a are arranged circumferentially at approximately 90° intervals. The multiple blades 222a have substantially the same size and shape. The number of multiple blades 222a is not limited to four and may be modified as appropriate.

[0063] Each blade 222a includes a first portion 225 and a second portion 226. The first portion 225 is a generally flat portion extending generally parallel to the up-down direction and extends generally linearly from the boss portion 221 along the radial direction in a plan view. The first portion 225 preferably extends generally parallel to the radial direction, but may extend in a direction inclined relative to the radial direction. The second portion 226 is a generally flat portion extending generally parallel to the up-down direction and is connected to a radially outer end of the first portion 225. In a plan view, the second portion 226 extends generally linearly from the radially outer end of the first portion 225 to the rear side in the rotation direction of the water turbine 22a. In a plan view, the angle formed between the first portion 225 and the second portion 226 of the blade 222a is, for example, approximately 90°. This angle may be changed in various ways. An outlet 224 similar to the above is provided at the end of the second portion 226 opposite to the first portion 225 (i.e., the edge of the blade 222a), and when the water turbine 22a rotates, deep seawater in a water turbine flow path (not shown) provided inside each blade 222a is discharged to the surrounding area from the outlet 224 by centrifugal force. In the discharge system 1, even when the water turbine 22a is provided instead of the water turbine 22 (see Figure 3), the flow of seawater around the floating body main body 21 can be efficiently used to rotate the water turbine 22a, in approximately the same manner as above.

[0064] The configurations in the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0065] 1. Discharge System 3 Water intake pipe 21 Floating body 22,22a water wheel 31 Water Intake 41 Mooring line 51 Pump 52 Power generating equipment 91 sea level 222,222a Feather 223 Water turbine channel 224 Discharge port J1 center axis

Claims

1. A discharge system comprising: a floating body moored by a mooring line and floating on the sea surface; a water intake pipe extending downward from the floating body and having a water intake port at its lower end; a vertical axis type water turbine attached to the floating body, positioned below the sea surface, and rotating in only one circumferential direction around a central axis facing up and down; Equipped with The water turbine is provided with a water turbine flow path that is connected to the water intake pipe and has a discharge port at an end portion on the outer side in the radial direction, A discharge system characterized in that, when the turbine rotates due to the flow of seawater, the seawater in the turbine flow path is discharged from the outlet by centrifugal force, and the seawater near the intake port is guided into the turbine flow path through the intake pipe.

2. The discharge system according to claim 1, The floating body has a columnar shape centered on the central axis, A discharge system characterized in that the water turbine is provided on the side of the floating body.

3. The discharge system according to claim 2, A discharge system characterized in that the water turbine is a propeller-type water turbine having a plurality of blades that each protrude radially outward from the side of the floating body and are arranged circumferentially.

4. The discharge system according to claim 3, A discharge system characterized in that each of the plurality of blades has a radial center portion curved so as to be convex toward the rotation direction of the water turbine.

5. The discharge system according to claim 3 or 4, The turbine flow path is provided inside each of the plurality of blades, The discharge system is characterized in that the discharge outlet is provided on an end edge of each of the plurality of blades.

6. The discharge system according to any one of claims 1 to 5, A discharge system characterized in that at least a portion of the floating body above the sea surface is independent of the rotation of the water turbine.

7. The discharge system according to claim 6, A discharge system characterized in that the entire floating body is independent of the rotation of the water turbine.

8. 8. The discharge system according to claim 1, a power generation device that generates power by utilizing the flow of seawater around the floating body; a pump driven by the power generated by the power generation device to assist the upward movement of seawater in the water intake pipe; The discharge system further comprises:

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