FR3086636A1 - FLOAT, ESPECIALLY FOR A FLOATING PLATFORM, ESPECIALLY FOR A FLOATING WIND TURBINE. - Google Patents

Abstract

The invention relates to a float 4 for a floating platform 3, comprising at least one enclosure 20 defining an interior volume 9 and formed by a side wall 22 and an upper wall 21, this enclosure comprising at its base an opening 12, and comprising advantageously means 13 for injecting pressurized air into the volume 9. The invention also relates to such a platform, in particular to a platform comprising a marine wind turbine.

Description

Description

Title of the invention: Float, especially for a floating platform, especially for a floating wind turbine.

The present invention relates to the field of platforms located at sea. It particularly relates to floats fitted to such platforms. More particularly still, it relates to floating platforms equipped with such floats and carrying wind turbines.

Such a platform generally includes at least three floats. These floats are made of thick metal sheets. Such floats are therefore heavy, which affects their buoyancy. In addition, given their dimensions, they require large and expensive equipment for their manufacture, as well as a long manufacturing time. The mass of steel used is also a significant cost factor.

The problem to be solved consists in minimizing the quantities of steel used in order to facilitate the manufacture of a platform, increasing the speed of manufacture, reducing the cost and increasing the buoyancy.

To solve this problem the invention provides a float for floating platform which comprises at least one enclosure defining an interior volume and formed by a side wall and an upper wall, said enclosure comprising at its base an opening. Preferably an opening over the entire horizontal section of the enclosure.

Advantageously, the float advantageously comprises means for supplying pressurized air and injecting it into the volume.

The invention also relates to a platform, which comprises at least three floats according to the invention. It also relates to a platform which includes a wind turbine.

Several embodiments of the invention will be described below, by way of non-limiting examples, with reference to the accompanying drawings in which:

[Fig.l] is an elevational and perspective view, from above, of a wind turbine system equipped with three floats according to a first embodiment of the invention, in the form of a bundle, the bundle comprising several tubes;

[Fig.2] is a detailed and perspective view from above of a float fitted to the platform of Figure 1;

[Fig.3] is a sectional view of a tube for the float of Figure 2;

[Fig.4] is a sectional view of a float according to a second embodiment of the invention;

[Fig.5] illustrates a third embodiment, adapted to a float of the type illustrated in Figures 1 to 3; and, [FIG. 6] illustrates a fourth embodiment, adapted to a float of the type illustrated in FIG. 4.

In the description, the terms "vertical" and "horizontal" refer to an equilibrium position of the wind turbine system, as shown in Figure 1.

Figure 1 illustrates a wind turbine system L In the example illustrated, the system includes a wind turbine 2 mounted on a floating platform 3. The platform 3 includes three floats 4 constructed according to a first embodiment. These floats are substantially identical to each other and equidistant from each other. One of the floats, on the left in the figure, is shown in detail, the other two floats are only represented by silhouettes, in dashed lines.

Figure 2 illustrates in more detail a float 4 according to the first embodiment. In this embodiment, the float 4 is formed from nineteen tubes 6 grouped together in the form of a bundle 7. This bundle 7 is inscribed in a substantially cylindrical shape, with a bundle diameter D7 and a bundle height H7. The tubes are arranged vertically, parallel to a vertical axis X4 of the float 4. The tubes all have substantially the same height, equal to the height H7 of the bundle 7.

In the example illustrated, the tubes are plastic tubes with a tube diameter D6. They are fixed together by glues or welds 8. These tubes are advantageously formed by interlocking of several tubular elements.

A tube 6 is shown in isolation in Figure 3.

Each of the tubes forms substantially over its entire height an enclosure defining an interior volume 9. The interior volume 9 is closed at the upper end 6A of the tube 6 by a plug 11 which forms an upper wall of this enclosure. This enclosure is open at the lower end 6B of the tube, over its entire section, through an opening 12.

Means 13 for supplying pressurized air are provided for injecting pressurized air into the interior volume 9. A tap 15 allows the injection of compressed air into the upper part of the volume 9, here through the plug 11. The injection of air inside the tube 6 makes it possible to maintain a pressure therein such that the free surface 14 of the water in the tube 6 maintains a level N14 close or identical to the lower level N6B of the tube 6. Any air leaks through the opening 12 at the base 6B of the tube, or by an accidental opening, are compensated by a supply of air supplied by the supply means 13.

As illustrated in Figure 2, the float 4 further comprises a belt 16. The belt is disposed in the lower part of the bundle 7. A lower part 17 of the tubes protrudes below the belt 16, over a height H17. The belt has a height H16 and a diameter DI6. The belt helps limit heaving under the effect of the swell.

In the example illustrated, the belt is formed of pipes 18 wound around the base of the bundle. The pipes are flexible or suitably deformed pipes of plastic, preferably of HDPE, welded or glued together and with the bundle.

Advantageously, the belt is formed of a single pipe which can serve as ballast. It can be provided to fill by gravity with water and be emptied by injecting air at one of its ends.

Each float 4 is secured to the rest of the platform 3 using two straps 19 enclosing the bundle, one at the top, the other at the bottom. The straps also include fixings, not shown, for fixing the bundle 7 there.

In the example illustrated, the specifications are:

- material of the tubes 6 high density polyethylene (HDPE) - nominal diameter of a tube D6 = 2 meters, approximately.

- height of a tube, a bundle H7 = 30 meters, approximately.

- diameter of a bundle D7 = 10 meters, approximately.

- height of a bulb H16 = 6 meters, approximately.

- diameter of a bulb D16 = 15 meters, approximately.

- diameter of a pipe D18 = 1 meter, approximately.

The use of HDPE for tubes and / or pipes is particularly advantageous. Indeed, this material is very durable in water and resists internal pressure.

Figure 4 illustrates a second embodiment for a float 4 according to the invention.

In this second embodiment, the float 4 comprises a single enclosure 20 delimiting a single volume 9, inside the enclosure 20. The enclosure is substantially of revolution about a vertical axis; it is made of sheet steel. It comprises an upper wall 21 and a peripheral wall 22. The enclosure comprises at its base an opening 12.

The absence of a bottom wall of the enclosure, at the location of the opening 12, makes it possible to significantly reduce the weight of the float 4. The economy of steel is proportional. The manufacturing cost is also greatly reduced. Buoyancy is increased.

In addition, the peripheral wall is subjected to low pressure stresses, compared to the closed floats of the prior art. Indeed, the pressure of the air in the enclosure being substantially the same as that of the water at the base of the float. Thus, the peripheral wall can have a reduced thickness compared to that of the prior art, therefore a lower weight and cost for the float.

As in the previous embodiment, means 13 for supplying pressurized air are provided for injecting pressurized air into the interior volume 9. A nozzle 15 allows the injection of compressed air in the upper part of volume 9, here through an upper wall 21 of the enclosure. The opening 13 allows water to rise inside the enclosure, in a controlled manner.

We will now describe a third embodiment, with reference to FIG. 5, in that it differs from the embodiment of FIG. 3.

FIG. 5 illustrates the lower part of a tube intended to form a bundle, as illustrated in FIG. 2.

The base of the tube is partially closed by an annular, horizontal plate 30. The opening 12 is formed in the plate 30, substantially in the axis of the tube 6. Due to the presence of the pierced plate 30, the horizontal section of the opening is reduced compared to the embodiment of Figure 3 The flow of water through the opening is thus hampered, which reduces the penetration of water inside the tube and the exhaust of air outside the tube.

We will now describe a fourth embodiment, with reference to FIG. 6, in that it differs from the embodiment of FIG. 4.

FIG. 6 illustrates the lower part of a metal float, as illustrated in FIG. 4.

The base of the tube is partially closed by a plate 30, substantially horizontal. The plate 30 is pierced with several openings 12, regularly distributed. The pressure on either side of the plate 30 being substantially the same, thanks to the presence of the openings, the thickness of the plate 30 can be reduced compared to a fully sealed plate as in the prior art. Thus, in addition to the presence of the openings, the reduced thickness of the plate allows a significant reduction in the weight of steel used.

As in the previous embodiment, due to the presence of the pierced plate 30, the open horizontal section is reduced compared to the embodiment of FIG. 4. The flow of water is thus hampered, which reduces the penetration of water inside the float 4 and the exhaust of air outside the float 4.

In the embodiments particularly illustrated in Figures 3 to 6, the injection of air inside the volume 9 allows to maintain a pressure such that the free surface 14 of the water can be maintained there at a level N14 close to or identical to that of the opening 12. Any air leaks through the opening 12, or by an accidental opening, can thus be compensated by a supply of air supplied by the supply means 13 .

By varying the pressure inside the volume 9, the level can be varied

N14 water in the enclosure. This stabilizes the stabilization of the platform 3, by ballasting, by adjusting the air pressure in the enclosure. We can thus control the stability and the level of submersion of the platform.

One can in particular intervene when a leak repair is necessary, by maintaining a pressure slightly greater than the hydrostatic pressure at the level of this leak.

It also appears that the volume of air 9, compressible, advantageously serves as a shock absorber for the vertical movements of the float 4.

Of course, the invention is not limited to the examples which have just been described. On the contrary, the invention is defined by the claims which follow.

It will appear to those skilled in the art that various modifications can be made to the embodiments described above, in the light of the teaching which has just been disclosed to him.

Claims (1)

Claims [Claim 1] Float (4) for floating platform (3), characterized in that it comprises at least one enclosure (6,11; 20) defining an interior volume (9) and formed by a side wall (6; 22) and a wall upper (11; 21), said enclosure comprising at its base an opening (12). [Claim 2] Float according to claim 1, characterized in that it further comprises compressor means (13) for injecting pressurized air into the volume (9). [Claim 3] Platform (1), characterized in that it comprises at least three floats according to one of claims 1 or 2. [Claim 4] Platform according to claim 3, characterized in that it comprises a wind turbine (2). 1/5