ES2549830A1 - Water column oscillator converter, with float, low inertia and double-turn rotary mechanical energy accumulator mounted on the transmitter train. - Google Patents

Abstract

Water column oscillator converter, with float, low inertia, which is not affected by the level of the tide, to be built on the coast or in a floating structure anchored near the coast. To achieve maximum energy use, taking into account the high period of the waves and the short time that the water level is at its maximum, a low inertia design is made with double-rotating rotary mechanical accumulators (ARDG) and accelerator of upward movement.

Description

OBJECT OF THE INVENTION

The object of the invention is an energy converter of sea waves into electrical energy, comprising a guided float that moves linearly vertically in an alternative manner, matched according to the rhythm of the waves at their location, and whose work is not It is affected by the level of the tide. The structure of the converter will preferably be mounted fixed on the coast. To achieve maximum energy utilization, looking for the maximum upward vertical displacement of the float, transferring energy in the shortest possible time, it is designed with low inertia elements from the float to the first mechanical double-rotating rotary energy accumulator (ARDG). Optionally, to improve its efficiency, an upward motion accelerator can be mounted that pulls the float assembly vertically upward along its entire length, decreasing the time of the ascending path and increasing that of the descending path.

SECTOR OF THE INVENTION

Renewable energy sources. Harnessing the energy of the seas. Clean energies.

BACKGROUND OF THE INVENTION

In the current state of the art there are many devices designed to take advantage of marine energy also known as energy from the seas or oceans. Some take advantage of the energy of the tides (tidal wave), others the energy of the oceanic thermal gradients (OTEe), others the osmotic energy (from the salinity gradients), others the marine wind energy (produced by the marine winds), others the energy of the marine currents and finally others, like the one that the invention proposes, that take advantage of the energy of the waves also known as wave or wave energy.

As for the location with respect to the coast, some are mounted in deep waters, far from the coast; others in shallow waters, near the coast and others are mounted on the rocks on the coast.

The energy associated with the waves varies from one area to another. It is greater between the 30 ° and 60 ° parallels of both hemispheres. On the Galician and Cantabrian coast, the average value exceeds 40 kW per m of wavefront.

The first patents for wave exploitation date back to 1799 in France (Girard and son), and in Great Britain in 1833. Today they exceed one thousand.

In the process of converting wave energy into useful energy with float converters, a primary conversion can be distinguished:

• from the movement of the waves (with a period in volume at 10 s) a float moves in a vertical direction (with a velocity around 2 mis)

and a secondary school, usually with one of these proposals:

•

the float drives the piston of an air compressor, which is sent to a pressure vessel or,

•

the float drives the plunger of a pump that pumps liquid to an elevated tank or a pressure tank that will subsequently be turbinated to drive an electric generator, or,

•

Directly activate the translator of a linear generator. This solution, today, is unsatisfactory.

With regard to float converters, in all current designs the energy use is reduced because all floating displacement energy cannot be transferred in the short time available.

DESCRIPTION OF THE INVENTION

The wave converter that the invention proposes constitutes an important technological advance in that it allows to increase the energy use of this renewable and non-emitting pollution resource.

The object of the invention is a wave energy converter in electric energy, with float on the oscillating water column and a low inertia mechanical interface to the first double-turn rotary accumulator (ARDG).

The period of the waves is about 10 seconds. When the wave reaches the coast an elevation of the level of water that drives the float upwards is caused, but the time that the water lasts near its upper level is very short and during that time the transfer of energy to the water must take place. accumulator. The way in which this invention approaches the reduction of the time of this process is to achieve the conversion with a design of very low inertia and for this the masses in linear displacement are made with very little mass and the masses with rotary movement with very low moment of inertia.

The description of the invention will be made with the help of Figures 1 and 5.

In the intermission between two consecutive wave crests the float is at its lowest point. When the wave reaches the converter there is an increase in the level in the water column in which the float is located (marked with 1). There will therefore be a vertical upward thrust. The flexible cable (3), hooked on the bottom of the float, will be subjected to traction all the way to the hook knot piece (5). The only section of cable that is left with hardly any tension is the section marked with (13). During the upward travel of the float, the hitch knot (5) will also move upward, in unison with the float. The chain (6) steers practically vertically through the pinion (7) to the wheel (8) that transmits the rotation torque through the mechanical rectifier (20) ("ratchet") to the coupling node (5). the cogwheel (21). This wheel is geared with the pinion (29) that transmits the movement of inlet rotation, through the axle (28), to the ARDG accumulator (24) which has on its outside a cogwheel (25) that meshes with a pinion ( 26) doing a multiplication of angular velocity. In the design of Figure 5, two other stages of energy accumulation - speed multiplication, marks (30) to (37) are added. The exit of the third stage

(37) is transmitted through the coupling (38) to an electric generator (39), such as a dynamo, an induction generator, a synchronous alternator or, preferably, a double-powered induction generator (DFIG) providing energy mains electricity (40)

Note that in conventional spiral mechanical mechanical accumulators, as in the case, for example, of the "rope" of the clocks, the spring is produced by rotating the shaft in one direction, compressing, and the return of energy is produced by rotating the axis in the opposite direction, decompressing. In the ARDG accumulator, the shaft rotates only when energy is transferred to the spring, and when it does not remain still; and the stored energy output is transferred, not through the axis, but through the crown gear.

A converter like the one described could be built with a fixed structure on the coast (on shore), this would be the most reasonable option for a high power plant, but for units of smaller power, floating units could be mounted anchored near the coast.

The converter that the invention proposes is a device -preferably-fixed for coastal location (Onshore), for wave use (WEC, Wave Energy Converter) from the oscillation of the water column (OWC, Oscillating Water Column) with float in vertical oscillation, to take advantage of the potential energy of the wave, proportional to the displaced water and the path.

That is why, in order to obtain a good energy use, the converter that the present invention proposes is designed to:

• from the linear, intermittent and alternative movement of the float, through a low-inertia mechanical interface to the first spiral rotary accumulator, helped with an accelerator of upward movement, and through

several stages of accumulation and multiplication of speed, obtain a rotating, unidirectional and constant movement, appropriate to drive an electric generator.

It will be explained below, with a simplified model, the advantage of mounting an accumulator in the transmitter train, following the float.

Figure 7 on the left shows the action of the float, which is located on the crest of the wave, acting through the mast directly on the elastic energy accumulator. In figure 7 right there is no elastic accumulator.

Nomenclature:

a: mast acceleration.

MF: mass of the float and mast assembly.

Fw: Archimedes thrust.

1: moment of inertia of the drum with respect to its axis of rotation.

r: drum radius.

P: weight that the drum should raise.

g: acceleration of gravity.

If the radius on the outer end of the spiral, the point on which the mast acts, is equal to the radius of the drum, r, the acceleration to which the float-mast assembly is subjected will be expressed by:

R - (P + M .g)

a = W F Mf

In the case of the right figure 7, where the mast acts directly on the end of the drum radius, the acceleration will be worth:

a = Fw - (P + MF · g) M + pi + JI2

F

I g I r

\ I

Since in the second case the denominator is greater, the acceleration will be smaller.

In conclusion, for the design with the accumulator placed immediately after the mast, the acceleration is not diminished by the masses that are located after the accumulator, thus allowing the transfer of energy in a short period of time. In addition, the mass of the float can be very small, it can be a balloon if the design shown in Figure 1 is chosen. This is one of the design advantages that the invention proposes compared to the designs of the known converters. In addition, the effects of acceleration losses caused by viscous resistances must be considered in converters that include fluids.

BRIEF DESCRIPTION OF THE DRAWINGS

To complete the description that is being made and in order to help a better understanding of the features of the invention, a descriptive and non-limiting set of figures is attached as an integral part thereof.

4 alternatives for secondary wave conversion are shown, Figures 1,2,3 Y4; the train of transformation and accumulation, figure 5, and a detail of an ARDG accumulator that can also have a spin speed multiplier effect, figure 6.

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Figure 1 shows the profile of the wave energy converter in electric energy, with float on the oscillating water column and a low inertia mechanical interface to the first rotary accumulator.

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Figure 2 is analogous to Figure 1. It is an alternative to the previous design.

The float has a piece of "mast" at the top, longer than the tidal oscillation. From the upper end of the mast the effort is transmitted to the quadrilateral formed by the flexible cable.

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Figure 3 is analogous to Figure 2 but with a mast of greater length than the counterweight 42 pulls through the sheave 41

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Figure 4 is analogous to Figure 3, but now the accelerator of the movement in the upward movement instead of being a counterweight is replaced by a spiral spring that pulls up the float-mast assembly, to accelerate the upward movement in all its route.

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Figure 5 represents the train from the gearwheel marked 8 to the electric generator.

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Figure 6 represents one of the possibilities for the constitution of the double-inertia double-rotating rotary energy accumulator with the possibility of multiplication of rotation speed (ARDG). The shaft 28 and the outer crown 25 always rotate in the same direction. In spring 23 accumulation occurs, in the form of elastic energy.

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Figure 7 represents the advantage for float acceleration, when the accumulator is first actuated.

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Figure 8 represents an example of a floating WEC-QWC-FLI converter.

DESCRIPTION OF A PREFERRED EMBODIMENT

The particular embodiment shown in Figure 4 will be described. A fixed structure is mounted on a coast area beaten by the waves that allows the free vertical displacement of the float, light and preferably of corrosion-resistant material. To avoid collisions between guides and float, some wheels are mounted on all sides. The mast is mounted on the upper face of the float. Inside the float a light metal structure can be mounted that adequately transmits the forces to the base of the mast and can also be filled with expanded polyurethane foam.

For the weight to be reduced, the mast should be hollow. As a material, aluminum can be a good option. The hook knot can be a reinforcement piece welded to the mast.

During the upward movement of the float, the chain (6) is subjected to traction, with a very high tension (depending on the volume of the float can be of the order of several tons) and will rotate the wheel (8) in a dextrogiroidal direction. As can be seen in Figure 5, the mechanical rectifier will transmit the torque to the wheel (21) that is engaged with the pinion (29) that drives the shaft (28) of the first double-turn rotary accumulator (24). For each revolution of the wheel (8), the axle (28) will have turned several revolutions, for example 6. The wheel (21) must be carefully designed so that its moment of inertia is reduced. The pinion (21) with its axis (28) will rotate in a levógiro direction and flexing the spiral metal strip will accumulate mechanical energy. The container cylinder of the spring can rotate and by means of the fixed toothed crown on its outside it will transmit the rotation to the pinion to which it is engaged. For every 6 revolutions of the shaft (28), the pinion (26) and the shaft (27) will have rotated, for example, 60 revolutions. With two more stages of accumulation-multiplication, the electric generator will have rotated, for each revolution of the wheel (21), 6000 revolutions.

To facilitate the upward movement of the float and reduce the rise time, an upward movement accelerator can be mounted that pulls the float assembly vertically upward during the upward travel, for example with a rotary accumulator, marked with (44) in the figure 4, whose axle is attached to the wheel (43) on which the chain is mounted, marked with (45), which pulls the mast up.

During the downward travel of the float, the chain (6) will lose almost all tension and the chain will move on the wheel (8) thanks to the counterweight (9). This levographic rotation of the wheel (8) will not be transmitted until the wheel marked with (21) in figure 5 thanks to the interposition of the mechanical rectifier marked with (20) in figure 5. The effect of the rotary accumulator (44) during the downward run is that it will slow down the float's descent.

During the downward travel of the float, the chain (12) will be tensioned and rotate the wheel (11) in a dextrogiroidal direction. As can be seen in Figure 5, the wheel (11) will transmit the movement to the wheel (21) through the mechanical rectifier (22). For each revolution of the wheel (11), the wheel (21) will have turned, for example, 1.5 revolutions and the process will continue in the same way as explained for the upward travel of the float.

5 It is not considered necessary to make this description more extensive so that any person skilled in the art understands the scope of the invention and the advantages derived therefrom.

The terms in which this report has been described must always be taken in a broad and non-limiting sense.

Claims (8)

1.-Double-rotating rotary energy accumulator (ARDG) comprising an energy input shaft, receiving the mechanical input energy with unidirectional, continuous or impulse rotation, and on said axis an end of the elastic accumulator element, strapping, is fixed metallic or of another material, in spiral, and the other end of the spiral fixed to the inner face of the cylinder that contains it; the outside of said cylinder mounts a circular, concentric, toothed crown and with the rotation of the whole assembly in the same direction of rotation as the axis, transmits the movement with a continuous and constant rotation to a pinion, through gear or by means of chain or belt drive. 2.-Wave-type water column waveform converter, with float, to be mounted on the coast, or near the coast by floating structure, comprising a float that moves vertically alternately, upward-downward stroke, following the movement of the surface of the water and mechanically transferring energy from the float through the mast-chain-sprocket-spin-speed multiplier mechanism to one or more ARDG accumulators according to claim 1, for each run. 3.-Wave water column waveform converter, with float, to be mounted on the coast, or near the coast by floating structure, which comprises a float that moves vertically alternately, upward-downward stroke, following the movement of the surface of the water and mechanically transferring energy from the float through the flexible cable mechanism working with traction-chain-cogwheel-spin-rectifier-speed multiplier to one or more ARDG accumulators according to claim 1, for each run . 4. Waveform converter according to claim 2 comprising an upward motion accelerator, constituted by a counterweight, which vertically pulls up the float assembly along its entire length. 5. Waveform converter according to claim 2 comprising an upward motion accelerator, consisting of an energy accumulator by means of a spiral strap, which vertically pulls up the float assembly along its entire length. 6. Waveform converter according to claim 3 comprising an accelerator of upward movement, constituted by a counterweight, which vertically pulls up the float assembly along its entire length. 7. Waveform converter according to claim 3 comprising an upward motion accelerator, consisting of an energy accumulator by means of a spiral strap, which vertically pulls up the float assembly along its entire length. 8.-Waveform oscillating water column converter, with float, to be mounted on the coast, or near the coast by floating structure, comprising a float that moves vertically alternately, upward-downward stroke, following the movement of the surface of the water and that mechanically transfers the energy from the float through the mast-chain-cogwheel-spin-speed multiplier mechanism to a first ARDG accumulator according to claim 1, for each run; the output of this first ARDG accumulator is 10 applies, by means of a speed multiplier, to a second ARDG accumulator; the output of this second accumulator is applied, by another speed multiplier, to a third ARDG accumulator or to the input shaft of a rotating electric generator; The output of the third ARDG accumulator is applied, by another speed multiplier, to the input shaft of a rotating electric generator.