RO130432A2 - Submerged wave-energy collector - Google Patents

Abstract

The invention relates to a submerged wave-energy collector able to convert wave energy into useful mechanic work, which can be exploited either as such, or within an assembly of several devices, in this case having also the effect of significantly reducing waves amplitude and energy, hence, the aggressive effect thereof. According to the invention, the collector comprises a resilient tight cover of a box (4), which is made of two parts, i.e. a grate (5) providing it with rigidity and resiliency and an elastic membrane (6) wrapping the grate (5) and ensuring its tightness, the air cushion enclosed by the tight box (4) providing additional resiliency to the cover, while the vertical back-and-forth movement of the resilient cover is transmitted to a rod (7) of a piston which slides inside a cylinder (8) provided with a suction valve wherethrough the working fluid within a pipe (9) is absorbed and a delivery valve wherethrough the working fluid is pumped into a pipe (10).

Description

ENERGY VALUE SUBMERS SENSOR

The invention relates to a simple device, capable of transforming the wave energy into a useful mechanical work that can be used either individually or in an assembly composed of several such devices, in the latter case, on the surface occupied by the whole of these devices, the amplitude (and the energy) of the waves is greatly diminished and their aggressive effect is greatly reduced.

At present, many proposals for wave energy captors are known, far too many to be reviewed here. In essence, it can be said that all these are placed either on the surface of the water or on the seafront, including existing dams and that they have multiple disadvantages. Among them, it is crucial that they have very high investment costs and their efficiency is strongly affected by the fact that the respective systems require numerous successive conversions of energy up to the form of useful energy (usually the electric one). In all cases, the technical - economic calculation regarding the cost / benefit ratio made it impossible for any one to be applied on an industrial scale.

The submersion sensor, according to the invention, has several advantages, essential for industrial application, eliminating almost all the disadvantages of the solutions proposed so far, as follows:

It is submersed; as a result, it does not disrupt sea surface activities and does not affect the marine landscape; this is essential for tourism and boating activities;

- Converts, on the spot, without other intermediate transformations, the relatively diffused energy, with a specific reduced value (related to the surface) of the wave into a "concentrated energy, technically and economically useful; more precisely, the pressure exerted by the wave, with a small value but distributed over a large surface, is instantly converted into a very high pressure, much more useful in industrial applications;

The high pressure produced by the device can be used individually, on the spot, in applications that require very high pressures such as, for example, the devices for desalination of sea water using special membranes and the reverse osmosis process;

The high pressure achieved by the device can also be used by "assembling" several devices of this type, by equipping them with volumetric pumps and coupling them so that they work "in parallel; In this way, high flow rates of fluids can be mobilized at high pressures, which can act with very good efficiency high power turbines in plants that can produce electricity with the parameters (necessary) of a direct injection into the national energy system;

The capture of wave energy produces simultaneously the reduction of their energy; at each "passing of the wave above such a device, its amplitude decreases and when mounted in the" battery, the wave field energy can be significantly reduced, thus representing a good shore protection solution, including beaches threatened by erosion of waves;

The proposed device is extremely simple and, therefore, the investment and operating costs are minimal, incomparably lower than of any solution / type of sensor proposed so far;

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The submersion sensor, according to the invention, comes in the form of a closed, sealed, empty (air-filled) box inside and provided with an elastic lid. The box is fixed in a horizontal position at a convenient depth, by a suitable anchorage. At shallow depths of sea water (for example, near the shores), the box can be placed, by an appropriate ballast, directly on the sea floor.

Figure 1 shows the operating principle of the collector according to the invention.

The collector (box) 1 is placed in relation to the average depth of the water h tic _stand, being fixed by means of anchoring blocks 2 and 3. The shift cable anchor wave, characterized by the wavelength and c the propagation speed of the produce , at the box lid level, successive pressure variations, with values, with approximation, between maximum Yh _ma x and minimum Yh _min (γ, the specific weight of seawater). The pressure variations in turn produce a variable pressure force with the amplitude AF = yAh, where A is the (horizontal) surface of the lid and h = h _ma xh _m i _n is the wave height. Due to the high value of surface A, even at modest h wave heights, the variation of the AF pressure force is very large. For example, at a box of 2mx2m (A-4m ² } and a wave with the height h = 2m, the force AF = 8.10 ⁴ N = 8tf.

According to the invention, this pressure force is transmitted to a rod, placed inside the box and in the center of the lid; this represents the useful force which, for example, acting on a piston in a cylinder (volume pump) produces much higher pressures. For example, in a cylinder with a section of 1 dm ² (0.01 m ² ), with the numerical values above, a pressure of the order of 8.10 ⁶ Pa - 80 bar results.

On the other hand, the variable pressure force acting from the outside on the lid, combined with its elastic reaction, produces the vertical movement of the lid and implicitly the rod that transmits the useful force, ensuring the operation of the volumetric pump.

Figures 2 and 3 show two embodiments of the invention.

In figure 2, the elastic and watertight lid of the box 4 is made of two parts: the grate 5 which provides its rigidity and the elasticity and the elastic membrane 6 which covers the grate and ensures its tightness. The captive air pillow inside the watertight box additionally ensures the elasticity of the lid. The vertical movement of the elastic cover is transmitted to the rod 7 of a piston sliding inside the cylinder 8; it is provided with a suction valve through which the working fluid in the pipe 9 is absorbed, respectively a discharge valve through which the working fluid is pumped into the pipe 10.

In figure 3, the elastic and watertight lid of the box 4 is also made of two parts namely: plate 14, rigid and impermeable and the peripheral elastic membrane 11 which ensures the tightness of the box. The elasticity of the lid is ensured by the presence of the springs 12. As in the example in figure 2, the vertical movement of the elastic lid is transmitted to the rod 7 of a piston sliding inside the cylinder 8; it is provided with a suction valve through which the working fluid in the pipe 9 is absorbed, respectively a discharge valve through which the working fluid is pumped into the pipe 10. In the example here, the air pillow inside the box is permanently kept at the atmospheric pressure through the pipe 13 such that the elasticity of the lid is provided exclusively by the springs 12.

As shown, the submersible wave energy sensor can be used both individually and in the "battery, by coupling several" units. From an economic point of view, it is preferable to use it in "battery", by coupling as many units as possible, creating fields to capture the energy of the waves, this system also having

the advantage of significantly reducing wave energy and reducing their potential for aggression.

Possible industrial applications include:

Seawater desalination plant; In this case, each unit in the catchment field is equipped with a reverse osmosis device, operated by the rod 7 and the desalinated water is discharged into the pipes 10, being collected and stored in a central reservoir by the proper connection of these pipes.

Hydroelectric power station; In this case, each unit in the capture field is equipped with a volumetric pump operated by rod 7; the working fluid, which may be a gas (air) or a liquid (water), is mobilized in the "closed circuit, being sucked in from the pipes 9 and discharged into the pipes 10, being collected and stored then, by the proper connection of these pipes, in a central tank that supplies the turbines (coupled with the electric generators); this reservoir, together with the pipes 10, forms a "buffer necessary to regulate the turbine flow rates but also to maintain their working pressures at the prescribed values; when the working fluid is a liquid (water), the reservoir must take the form of a hydrophoric (gas cushion); at the output of the turbines, the working fluid re-enters the closed circuit through the pipes 9, which are also properly connected.

Claims (1)

CLAIM Submersible wave energy sensor characterized by the shape of a closed, tight, hollow (air filled) box on the inside, a box that is provided at the top with an elastic lid having in the center and inside a normal rod on the lid and which shall be fixed to a suitable depth by anchoring or balling with the lid in a horizontal position; the variable pressure exerted when passing a wave on the surface of the lid induces a force which, combined with the elastic reaction of the lid, produces the vertical movement of the lid together with the inner central rod in which a very useful force is thus concentrated. high, equal to the entire pressure of pressure on the lid of the water from the outside, force capable of performing mechanical work at powers and yields that ensure its competitiveness from an economic point of view.