WO2011031132A1

WO2011031132A1 - Floating power station with submerged paddlewheel

Info

Publication number: WO2011031132A1
Application number: PCT/NL2009/000179
Authority: WO
Inventors: Hugo Krop
Original assignee: Hugo Krop
Priority date: 2009-09-14
Filing date: 2009-09-14
Publication date: 2011-03-17

Abstract

A floating power station is proposed, utilising horizontally moving water streams, unidirectionally or bidirectionally, with the following characteristics: An airtight cylindrical center part of the paddlewheel from which the blades project radially, bars any water turbulence inside the rotor by employing a hollow and closed cylindrical drum around the virtual or existing axis of the rotor, A semi open tunnel provides a half closed duct around the blades, which encapsulates water flow at the bottom part of the wheel, barring counter flow, leaving the top part of the circular arrangement of blades around the wheel open to accommodate the accelerated flow of water. One or two floating and vertically free moving cylindrical drums provided with rims or small blades to adopt a circular motion by the streaming flow of water (and thereby reducing drag) can be added to the floating platform parallel to the main rotor in order to suppress the turbulences and counter currents (e.g. the effect of strong winds) at the top part of the horizontal water stream, adding an accelerating effect to the water by means of a narrowing duct.

Description

Floating power station with submerged paddlewheel

A power station utilising the energy of flowing water in a(n almost) horizontal natural flow is proposed, leaving the sea or river bed free as it floats above it, moving freely vertically along the supports that anchor its position parallel to the water surface.

Tidal streams near lowlands and rivers crossing lowlands (in most parts of the world) rarely exceed the speed of 1,5 metres a second. The surface layer of these streams usually shows turbulence and sometimes multidirectional counter currents.

Such velocities are usually insufficient to provide an opportunity for means to generate power for remote utilization, unless further infrastructure is utilized such as dams or weirs.

Attempts to utilize a horizontal (no head) water flow with submerged paddlewheels to generate power are known from (a.o.) the PCT patent publication WO 03/029646 and the UK patent publication GB 2 408778. The power generating rotors are fully or mostly submerged and utilize a part of the water flow, which drives only the top part of the rotor, accommodating for changing flow directions (bidirectional).

A narrowing guide channel provides a means of increasing the velocity of the water stream at the position where the kinetic energy of the water stream is transferred to the paddlewheel. The kinetic power of the rotor or rotors is transferred to a power generator through a cog-wheel or set of gears as utilized by wind generators.

Wheel movement is relatively slow, rotation speed is to be increased by a type of gearing to drive a generator or pump, by direct or hydraulic transfer of rotational movement to the generator.

An improvement to existing and known art can be made by adding the following characteristics to the floating power station:

Closing the core part of the paddlewheel off to water turbulences by employing a airtight cylindrical drum around the (virtual or existing) axis of the wheel, from which blades or paddles project radially. This drum can be vacuumized or filled with air or a lightweight pure gas (other than air containing oxygen), reducing oxidation and the growth of algae on the inside, reducing the overall weight (under water) of this rotor.

Furthermore, by providing a half closed duct around the blades, which encapsulates water flow in a tunnel at the bottom part of the wheel, leaving the top part of the circular arrangement of blades around the wheel open to accommodate the accelerated flow of water. The water flow will keep this encapsulated water in motion in whatever direction it is flowing by means of suction and motion, thereby reducing possible drag at the bottom part of the encapsulated wheel while it is being driven by the accelerated flow at the top. Flexible blades will adopt a curvature more advantageous to transfer of water pressure. Additionally, a floating, vertically free moving cylindrical drum, provided with rims or small blades to adopt a circular motion by the streaming flow of water, reducing drag, can be added upstream parallel to the main rotor in order to suppress the turbulences and counter currents (e.g. as the effect of strong winds) at the top part of the horizontal water stream. This drum can be lifted to be able to let floating objects (e.g. ice) pass.

Another function of this drum is to guide the water flow into a narrowing duct, adding to the function of the narrowing duct formed by the converging water inlet.

When using a power station utilizing bidirectional water streams (as e.g. the result of tides) two of these floating cylindrical drum should be used (instead of one), one opposite the other parallel to the main rotor, as shown in the drawing of the proposed model (FIG 1 and 2).

The floating abilities of the station platform can be adjusted by pumping water in or out the 4 flotation compartments of the station platform. Explanation of drawings FIG 1 and FIG 2.

A = driving and power generating main paddlewheel type rotor in a semicircular half closed casing

B = surface part of natural water flow to be compressed and accelerated

C = main part of natural water flow to be compressed and accelerated

D = part of natural water flow accommodating the passage of sea life

E = floating drums, vertical movement allowed, can be lifted up

F = flow narrowing duct, airtight and vacuum or gas filled or foam filled

G = generator and gear housing

H = separate flotation chambers of floating station, floating level adjustable

I = part of narrowing duct that may be built of lighter material, e.g. suspended framed fabric

J = traverse beam, rod or cable to further ensure structural integrity

Claims

1. floating power station, generating power by means of a (geared) drive, hydraulic drive or pneumatic drive, utilizing the kinetic energy of a mainly horizontal water stream, provided with the means to accelerate a natural water stream through a narrowing duct, mostly effective at the position of a submerged power generating rotor consisting of an airtight cylindrical drum or set of drums with radially extending blades.

2. floating power station as in claim 1, adjustable to the surface of a water

stream or its support structure by pumping water in or out opposite flotation chambers.

3. power station as in claim 1 and/or 2, whereby the rotor and its blades are

encapsulated by a semicircular tunnel at the position where the blades would be counterproductive when turning round (if not encapsulated) in the opposite direction of the main water flow.

4. power station as in claim 1 and/or 2 and/or 3, whereby floating drums, vertically free moving and/or vertically liftable, in a parallel position to the main driving rotor, can be employed in order to suppress turbulence and crossing counter currents, at the same time adding to the effect of a narrowing tunnel accelerating the water speed.

5. power station as in claim 1 and/or 2, 3, or 4 where the cylinders and/or the airtight space under the tunnel and/or duct ( space F) are vacuumized or filled with a gas or filled with foam or foamy material to exclude oxygen and reduce weight under water.

6. power station as in claim 1 and/or 2, 3, 4 or 5 whereby the rotor blades are made of a flexible material, such as (but not restricted to) a fabric used for sails as e.g. Dacron or Kevlar, movably fixed to frames, which adopt a curvature (in both directions) as a result of water pressure providing a curved (convex) profile that is more efficient than a flat blade or paddle in transferring water pressure to the blades of the rotor.