Underwater flow turbine using automatic blade pitch positioning

Abstract

The present invention relates to a method for recovering the forward power of underwater or surface water flows, wind speeds and waves involved in renewable energy sources through a pumping system and converting their kinetic energy into electrical or potential energy by using a constant flow vertical axis turbine with automatic turbine blade pitch positioning. The energy in the form of coast surfing waves is also a source of energy that can be recovered in an available form.

Description

Technical Field

[0001] The present invention relates to a method of recovering the forward momentum of underwater or surface currents, wind speed and waves involved in renewable energy through a pumping system using a constant flow vertical axis turbine with automatic turbine blade pitch positioning and converting their kinetic energy into electrical or potential energy. Energy in the form of coastal surf waves is also a source of energy that can be recovered in a useful form.

[0002] By generating a rotational motion within the working principle of the system, the use of which can drive a set of permanent magnets surrounded by a conductor and induce a voltage / current therein or pump a liquid to a higher plane, thus creating a potential energy recovery system. Background Art

[0003] There are approximately 1,000 designs of ocean energy conversion devices, and nearly all of them use the principle of buoyancy. The heaving motion obtained by passing waves is converted into pure direct electricity or used to pump liquid to higher levels.

[0004] There appear to be no devices that extract the kinetic energy available to traveling waves or use the wave velocity in their design.

[0005] The International Renewable Energy Agency (IRENA) lists the types of hydrodynamic tidal current conversion systems in its 2014 Marine Energy Report, page 19, section 3.2, and most of these devices use

[0006] 1. Horizontal axis axial flow turbine

[0007] 2. Vertical cross-flow turbine

[0008] In the first case above, the blades rotate about a horizontal axis, much like a wind turbine, and these systems require significant sea depth to accommodate the diameter of the turbine, and the turbine needs to be placed within the ocean current. The incoming flow passes over the turbine blades parallel to their axis, and the rotation is based on the airfoil geometry which causes lift and therefore rotation.

[0009] In the second case above, the incoming flow causes the blades to rotate about the vertical axis of the turbine. This again uses the airfoil geometry of the blades to generate lift which causes torque, thereby creating rotation about the vertical axis. This again would require the turbine to be placed in deep water along the ocean current.

[0010] US Patent No. 7,279,803 Bl describes an axial flow turbine in which the flow is parallel to the axis of rotation.

[0011] European patent number EP 1467092A3 describes a blade pitch mechanism, but it relates to an axial underwater current turbine.

[0012] US Patent No. 2015 / 0035279 Al describes a wave energy conversion system that uses the buoyancy principle in its energy conversion mechanism.

[0013] US Patent No. 7911074B2 describes a conical auger turbine for converting hydrokinetic energy into electrical energy. The rotation of the turbine is in a horizontal plane and has a rolling profile causing the rotation. The blade profile is complex in the construction of the turbine, like the helical rotor of the helical rotor pump of the mixer's 'auger'.

[0014] US Patent No. 4,184,212 also describes a helical rotor apparatus and its use in producing hydrogen for other uses.

[0015] US Patent No. 8624417 B2 describes a system in which a turbine is placed in a container and seawater is introduced into the container using the wave angle.

[0016] Australian patent number 2017100917 describes a system in which the turbine blades present different angles of attack to the traveling medium, creating differential areas on the other side of opposite quadrants. However, the blade areas presented around the central blade support shaft are symmetrical, and in this way, the rotational torque around the blade axis itself will be the same and no rotational torque will be generated. The application also describes a system in which the blades are fixed around the blade shaft with equal areas and rotated by means of an actuator. Therefore, the actuator force will also need to compensate for the forces acting on the lower half of the blade area. In another form, a set of hinges holds the blades that rotate freely on a shaft that is provided with a plurality of pins and limits the rotational movement of the hinged blades. The present invention involves a plurality of moving parts, namely hinges, which are directly exposed to the environment and are thus more prone to failure.

[0017] The present invention aims to overcome these disadvantages and proposes a novel turbine design.

[0018] Variation of the blade angle of attack is an essential feature of the invention and a means of providing different areas exposed to directional currents, and is achieved by rotating the blade so that it presents a very small impact area to waves on one side whilst maximising the area in the opposite quadrant.

[0019] The rotation of the blade itself is achieved by presenting a differential area across the blade support shaft. The blade area around the blade's own axis is asymmetric, with one segment having a larger area around the blade support shaft axis than the other segment, so that a differential load acts on the blade itself, causing the blade to rotate along its own axis.

[0020] One quadrant of the blade then projects the full blade area, while the blade in the other quadrant presents a much smaller area, and the kinetic energy difference ensures that the rotational motion is maintained.

[0021] Therefore, two sets of differential areas are required to generate rotation along the main vertical axis, which in turn rotates the permanent magnet generator via multiple or one step-up gearboxes.

[0022] The entire assembly is provided with suitable mechanical seals to allow it to operate underwater.

[0023] In another form of the invention, a flow accelerator is mounted in front of the water turbine and it is intended to accelerate the fluid flow towards the blades.

[0024] For example, the power of the water turbine (500) is controlled by the basic equation P = 1 / 2 × Rho × A × V3

[0025] in:

[0026] aP: power, watts

[0027] b.Rho: fluid density: kg / m 3

[0028] cA: blade area: m 2

[0029] dV: fluid velocity: m / s

[0030] It can be easily seen that, at constant density, power varies directly with area and with speed as a cube. Therefore, to increase power, either blade area or speed can be increased. In view of the fact that power is a cubic function of speed, the present invention aims to increase the speed entering the 'flow enhancer' but gradually reduce the flow area so that the forward speed is increased with a smaller area.

[0031] Conventional underwater wind turbines mimic the geometry of wind turbines and, in order to increase power, require large diameter shrouds, which are largely impractical and require deep water installation sites. With respect to the present invention as presented herein, shallow water bodies are sufficient to install the flow enhancer. DETAILED DESCRIPTION

[0032] Now refer to Figure 1

[0033] Figure 1 An embodiment of the invention is represented and is a cross-sectional assembly view showing the key features of the device.

[0034] The water current turbine (500) comprises a main housing (1) containing a permanent magnet generator (12), which is connected to a step-up gearbox (9) via an intermediate shaft (10) and is centralized with a support head (11). The planetary gearbox (9) is connected to another step-up gearbox (6) via an intermediate shaft (7). The output shaft of the step-up gearbox (6) is equipped with a secondary shaft (4) and a main shaft (3), and is connected to a thrust block (5) supporting the generated load.

[0035] The main shaft (3) is connected to a torque disc (19) which holds components for supporting the blades (15).

[0036] Now refer to Figure 2 and Figure 3

[0037] Figure 2 Plan and front section views showing the major rotating components.

[0038] Attached to the torque plate (19) are a plurality of bearing housings (22) which support the blade support shafts (16) which in turn rigidly hold the blades (15) in place.

[0039] The torque transfer stud (17) is fixed to the blade support shaft (16) and allows a predetermined rotation angle of the blade support shaft (16). The torque transfer stud (17) rests in front of a torque transfer block (18) which is fixed to a torque disc (19). A blade shaft seal (23) is shown.

[0040] The direction of water flow (100) is shown.

[0041] Now refer to Figure 4

[0042] This figure shows a front cross-sectional view of another preferred embodiment of the present invention.

[0043] Here, a floating body (201) houses a permanent magnet motor (12) and a gearbox (6), and the assembly floats on a body of water (such as a river or tidal current).

[0044] The bearing thrust block (5) supports the main shaft (3), on which a torque wrench (19) as well as a blade support shaft (16) and blades (15) are provided.

[0045] Now refer to Figure 5

[0046] The figure shows a plan view of a preferred embodiment of the present invention equipped with a flow accelerator (300).

[0047] The floating body (201) houses an accelerator (300) and the accelerator is intended to increase the velocity of the flow (100) so that the flow rate at the blades (15) is increased.

[0048] Now refer to Figure 6

[0049] The figure shows the arrangement of a magnetic coupling arrangement.

[0050] The permanent magnet (52) is placed on the main shaft (3) and placed to the torque plate drive collar (51) and supported by an independent thrust bearing (53). The containment shell (50) is placed between the permanent magnet (52) on the drive collar (51) and the permanent magnet (52) on the main shaft (3).

[0051] When the torque plate (19) is subjected to a rotational torque, the magnetic attraction flux between the permanent magnets (52) on the main shaft (3) and the permanent magnets (52) on the drive collar (51) drives the main shaft (3).

[0052] refer to Figure 7

[0053] The figure shows the flow enhancer (69) in plan and side elevation.

[0054] The flow enhancer (69) is made of a material suitable for the corrosiveness of the offshore marine environment and may also be suitably painted or coated to provide protection.

[0055] The inlet (60) allows a volume of fluid to enter the flow enhancer (6) and the fluid leaves the flow enhancer (69) via the outlet (61). The flow inlet is accelerated through the length of the flow enhancer (69) due to its reduced cross-sectional area.

[0056] The flow enhancer (69) comprises a top plate (62) and a bottom plate (63), which in a certain embodiment of the invention may be the top deck (12) of the hull (1). The side covers are provided by the LHS side plates (66) and the RHS side plates (65) and thus form a closed volume.

[0057] A slot (67) is cut into the RHS side panel (65) and is provided with a rubber or flexible rubber curtain (68).

[0058] In another embodiment of the present invention, the RHS side plate (65) is not provided with grooves (67) nor with rubber curtains (68), and the CFITG (5) is positioned further aft so that the blades (118) do not intersect the flow enhancer (69).

[0059] Now refer to Figure 8 , Fig. 9 and Fig.10

[0060] A floating hull (501) intended to float on a body of water (550) is equipped with two water current turbines (500).

[0061] Hydraulic actuators (502), typically four, fixed to the floating hull (501) are intended to lower the platform (503) into the body of water (550) to interact with the flow.

[0062] Fig. 9 shows the front elevation of an embodiment of the invention, and Fig.10 The platform (503) is shown lowered by means of hydraulic actuators (502).

[0063] The floating hull (501) is conventionally moored using standard mooring chains and anchors.

[0064] Brief operating principle

[0065] like Figure 2 As shown in FIG. 1 , the water flow ( 100 ) impacts the blades ( 15 ) on both sides of the main shaft ( 3 ).

[0066] like Figure 3 As shown, the area of ​​the blade (15) above the centerline axis of the blade support shaft (16) is greater than the area below it. This area difference results in different loads on both sides of the blade support shaft (16). This causes the blade support shaft (16) to rotate in a counterclockwise direction. The torque transfer stud (17) also rotates with the blade support shaft (16) and stops when it hits the torque disc (19) and the torque transfer block (18). The blade (15) is in a vertical plane and carries the load imposed by the water flow (100).

[0067] At the same time, on the other side of the main shaft (3), given the position of the torque transfer stud (17) and the differential area presented by the blade (15) to the same water flow (100) direction, the blade (15) is rotated in a clockwise direction together with the blade support shaft (16), and the torque transfer stud is now reversed and therefore the blade (15) on this side presents a much narrower area to the water flow (100).

[0068] Therefore, the differential force now generated on both sides of the main shaft (3) causes the overall rotation of the main shaft (3) along its central axis.

[0069] Since this rotation now rotates the blade (15), the new position rotates the blade (15) so that the blade presents a vertical surface to the water flow (100), so the differential torque is maintained and the rotation is continuous relative to the water flow (100).

[0070] When submerged operation is contemplated, a mechanical seal (13) is provided to prevent the external environment from entering the secondary housing (2) and the primary housing (1).

[0071] In other preferred embodiments of the present invention, a single gearbox (6) may be used.

[0072] In another embodiment of the present invention, the permanent magnet generator (12) is placed onto the floating body (201) together with the gearbox (6). This arrangement will ensure that these components are not in an underwater environment and no mechanical seals are required to prevent liquid infiltration.

[0073] In another embodiment of the present invention, in order to completely eliminate the use of a mechanical seal (13), the use of a magnetic coupling is utilized to transmit the rotational torque of the torque plate (19) to the main shaft (3).

[0074] All materials in contact with water or seawater are made of corrosion-resistant alloys.

[0075] In the event that the torque transfer stud (17) strikes the torque disc (19), a rubber pad or similar material may be used to absorb any impact and reduce noise. A plurality of such torque transfer studs (17) may be used along the blade support shaft (16).

[0076] The differential torque along the blade support shaft (16) and the differential torque generated on the opposite side of the main shaft (3) assists the operation of the turbine.

[0077] In another embodiment of the present invention, the permanent magnet generator (12) can be replaced by a pump, so that if the water body is a river, the river water itself can be pumped to where it is needed.

[0078] In another embodiment of the present invention, the permanent magnet generator (12) can be replaced by a conventional excitation generator.

Claims

1. An underwater water current turbine for generating electricity using water current, essentially comprising: a blade support shaft, the blade support shaft including blades, the blades being fixed such that the blade positions provide different areas around a longitudinal axis of the blade support shaft; The blade shaft is fixed to at least two bearing housings, wherein the bearing housings are fixed to a torque plate; a minimum of two torque transmitting studs secured to the portion, said blade support shaft being secured between said bearing housing; at least two torque transfer blocks fixed to the torque plate; A minimum of three of said blade support shafts are positioned around the area of ​​said torque disc; A housing assembly, wherein the housing assembly includes a plurality of gear boxes and a generator; a main shaft having a first end connected to the gearbox and a second end connected to the torque plate; Said main shaft provided with a collar for transferring thrust to the thrust bearing is fixed to a thrust collar; A seal spool housing a mechanical seal is secured to the thrust plate.

2. A water current turbine for generating electricity from water current as claimed in claim 1, but wherein the housing is not underwater and is secured to a floating body, and wherein the housing assembly is horizontal.

3. As described in claims 1 and 2, the mechanical seal is replaced by a permanent magnet, which is fixed to the main shaft and to the drive collar, wherein the drive collar is first fixed to the thrust bearing and the second end of the drive collar is fixed to the torque plate, and a containment shell is placed between the main shaft and the drive collar.

4. A renewable energy device as claimed in claim 1 and claim 2, but wherein the permanent magnet or externally excited generator and gearbox are suitable for underwater / submersible applications.

5. A renewable energy device as claimed in claim 1, claim 2 and claim 3, wherein the blades are inflated or deflated by an external or internal medium to achieve shape change.

6. As claimed in claims 1, 2 and 3, but wherein the floating body is provided with a flow accelerator.

7. As claimed in claim 4, wherein the accelerator is provided with a groove formed on the accelerator side and the groove is covered with a rubber curtain.

8. As claimed in claim 5, two water current turbines are fixed to a platform, placed on both sides of a floating hull, wherein the floating hull is provided with at least two hydraulic actuators, wherein one end of the hydraulic actuator is fixed to the floating hull and the second end is fixed to the platform.

9. A renewable energy device as claimed in claim 1, claim 2, claim 3 and claim 4, but wherein a plurality of assemblies comprise blades.

10. A renewable energy device as claimed in claim 1, claim 2, claim 3, claim 4 and claim 5, but wherein the number of blades depends on the assembly.

11. A renewable energy device as claimed in the preceding claims but wherein one side of the blades is completely elevated / not exposed to the incoming flow or waves.

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