FR2852063A1 - Wind turbine for generating wind energy, has set of propellers surrounded by streamline shroud which includes high, low and lateral panels to canalize wind towards propellers in open position - Google Patents

Abstract

The device has set of propellers (1) surrounded by a streamline shroud to provide a venture effect at the propellers, where the propellers include aero-dynamic surfaces. The shroud has high, low and lateral panels (3,7,5) to canalize wind towards the propellers in open position. A flywheel (33) is installed on a platform (10) to stock the energy, where the platform can be arranged on floating barges anchored far in sea.

Description

The present invention relates to systems for capturing energy from

wind.

  This energy is distributed throughout the planet but irregularly over time. An installation which must collect it cannot be dimensioned to operate with the maximum wind likely to occur at the location of its 5 implantation because the cost would be prohibitive On the north west coasts of France, for example, winds have been recorded reaching 250 km / h. The average wind speed is around 36 km / ht or 10 m / s - It is this last figure which will allow us to estimate the average power and therefore the overall number of kilowatt / hours that the installation will be able to supply in year. On the other hand, the installations must mechanically withstand extreme winds.

  If we consider the surface S of wind interception by a wind turbine, the volume of air passing through this section in one second is S x v, v being the wind speed. The specific mass of air (at ground level and at room temperature) being 1.29 kg per cubic meter, the mass of air passing through section S in l seconds is therefore 1.29 1 5 x S x v. It follows that the kinetic energy of this air mass is E = l / 2 x 1.29 x S x v3. For a wind turbine in the shape of a propeller (generally three-bladed in the current technique) section S is that of the circle containing the propeller. As an example, a propeller 76 meters in diameter (existing in France), i.e. S = 4500 m2, will see passing in its circumscribed circle, with the average wind of 10 m / s, an air mass of 4500 x 10 x 1.29 = 58,000 20 kg per second. The kinetic energy for each second, i.e. the corresponding power is equal to E = x 58,000 x 102 = 2.9 x 106 or 2.9 MW. Unfortunately the propeller will not be able to collect all this energy for two reasons - On the one hand the wind turbine constituting an obstacle in the air stream, part of the air streams bypass the wind turbine, causing a certain reduction in speed 25 prevailing in the air streams passing through section S. - On the other hand, part of the air streams crossing section S between the sectors swept by the blades. Although they contribute to the shape of the aerodynamic field around the blades, these air streams are far from yielding to them all of their kinetic energy. The energy collected by a wind turbine in fact comes only from the kinetic energy of the air stream. There is no thermodynamic energy collected since downstream of the wind turbine, the pressure remains atmospheric pressure and there has therefore been no expansion phenomenon. The theoretical studies of RANKINE-FROUDE have shown that a wind propeller has a possibility of recovering the kinetic energy of the air stream passing through it by a maximum of 60%. - 2

  We can estimate that according to the more or less optimal configurations of the propellers and their angles of attack, the used part of the kinetic energy of the air stream of section S is only 20 to 30 percent according to the conditions of wind.

  Furthermore, the visual impact of a wind propeller placed on a tall mast 5 (in France up to 125 m) is very significant. The best sites being by the sea, or on heights, it would be catastrophic for the environment to cover gigantic propellers of remarkable tourist sites of sea or mountain. Placing wind turbines on hulls floating at sea is a very old idea, many pleasure boats thus obtain their electricity in a very useful way, especially when they are in fairground mooring. Placing large wind turbines on barges anchored far enough from the coast will overcome a harmful visual impact.

  Whether on land or on barges at sea, to obtain the greatest efficiency and therefore the lowest cost, there is an interest in converting as much of the kinetic energy of the vein into usable energy. air appearing in front of the wind turbine.

  The methods according to the present invention overcome the disadvantages mentioned above. They are applicable to installations located on the earth's crust as well as on floating barges anchored at sea.

  These methods allow better efficiency while improving the problems of visual pollution and resistance to extreme winds. They are applicable to fixed installations on land or located on the seabed when the sea is shallow as well as to installations on floating barges anchored at sea.

  The main characteristic of the invention is that the rotating parts of the wind turbine are surrounded by a fairing above, on the sides and below so as to channel the air into a sort of funnel causing an effect. of Venturi. This fairing is composed, advantageously according to the invention, of a fixed part immediately surrounding the rotating parts and of hinged panels added to the fixed part of the fairing, which can, thanks to servo-control, take all positions from wide open to completely closed, in case of excessive winds to protect the rotating parts.

  Still according to the invention, the conventional propellers can then be replaced by turbines with a large number of blades. Several propellers or turbines can be placed side by side in the bottom of the funnel formed by the fairing. According to the invention also, these propellers or turbines can be replaced by mills with axes perpendicular to the direction of the wind.

  According to the invention also all the installations described above can be arranged on a terrestrial platform which can rotate around a pivot so as to always be facing the wind or on a floating barge which can rotate around its anchoring point. Still according to the invention, the installations comprise a tail unit making it possible to keep them facing the wind. In the case of barges at sea, they may also include, on the bow, a device for recovering the energy of the waves.

  Finally, they may have flywheels on board allowing energy to be stored.

  On board l: 10o FIG. 1 represents a sectional view of the invention.

  Figure 2 is a front view o several propellers, or turbines, are arranged side by side.

  Figure 3 is a sectional view of an installation according to the invention mounted on a barge anchored at sea.

  1 5 Figure 4 is a sectional view of an installation according to the invention where the rotating part is a mill with a horizontal axis.

  Figure 5 is a side view of an installation according to the invention with the upper and lower panels partially folded.

  Figure 6 is a sectional view of a wave energy recovery system 20 by filling basins.

  Figure 7 is a sectional view of a wave energy recovery system using floats at the end of articulated arms.

  With reference to these drawings, the systems according to the invention comprise rotating parts (1), surrounded by a fixed fairing (2) to which upper panels (3) can be attached by articulations (4), side panels (5) by joints (6) and bottom panels (7) by joints (8). This whole assembly forms a funnel channeling the air towards the rotating parts by accelerating it by the Venturi effect.

  In the case where, for the rotating parts (1), the technique adopted is the propeller, several of these, still according to the invention, can be grouped side by side as in FIG. 2. The propeller (s) (1), now being inside a channeled vein where the air speed is greater than in the open air, can see their number of blades increased and become blades (9), the system according to the invention then according to the turbine technique. - 4

  When the installation is terrestrial, that is to say fixed either on dry land or on the seabed, the platform (1 O) which supports it, is advantageously mounted on a pivot (11) to be oriented facing in the wind, either by means of a servo controlled by a wind direction sensor, or still according to the invention, by a vertical tail (12).

  When the platform (10) supporting the installation is mounted on a floating barge (13), it is able to orient itself facing the wind by turning around its anchor point (14) comprising a journal also thanks to the invention, as above, to a vertical tail (12). These empennages can, advantageously according to the invention, whether the installation is on pivots or on floating barges, be fitted with movable control surfaces (15) with vertical axis (16) making it possible to increase the rotation in the case where the Windward alignment is thwarted by yaw oscillations due to aerodynamic resonances or by a sea current (tidal current for example).

  It is advantageous that the anchor point (14) of a barge moves as little as possible, 1 s in order to be able to bring the barges closer to one another. To do this, several anchors or dead bodies (17) can be arranged on the bottom of the sea in a circular manner, the pin (14) allowing the barge to rotate around its anchor point.

  Without being limiting, the upper panels (3) and the lower panels (7) can be folded down as shown in FIG. 5 to protect the rotating parts (1) by partially or totally masking them in the event of very strong wind. The lateral parts (5) can also be mobile and fold back towards the front or disappear towards the rear, as also shown in FIG. 5. The aerodynamic drag of the assembly is reduced, which reduces the forces on anchorages, sea or land.

  In what has been explained above, the rotating parts (1) mentioned were propellers or turbines. According to a variant of the invention, the technique of the energy receiver can be that of a mill with a horizontal or vertical axis. Figure 4 is a vertical section of such a mill. The blades such as those indicated (18) in this FIG. 4 have an airplane wing profile, adapted to the low air flow speeds 30 which is the field of work of wind turbines. Advantageously, according to the invention, these wings can be of strong curvature without this being limiting. The advantage of such a mill is to make better use of the space, allowing installations that are lower and more compact, which reduces the impact. visual for terrestrial installations, all the more so since, painted in camouflage fashion, they can appear as ground movements. Finally the drag is reduced: Advantageously, according to the invention, the angle of attack of the different blades of the mill can be optimally adjusted according to their different positions during the rotation, by orienting the cord of each wing constituting These vanes. This orientation can be done either by rotating the whole wing around an axis (19) located at the thrust point of the wing, that is to say about 25% of the chord, or by providing it with high lift flaps (20), the deflection of which can be adjusted, either by carrying out the two operations at the same time. Control of these angles can be obtained either by a servo control controlled by air direction sensors, either by a set of rods similar to that commonly called a “spider” which controls the angle of attack of the helicopter blades.

  To avoid excessive bending of the blades, a mill can be sectioned into sections carried by intermediate bearings. To lighten the construction, several 5 s mills with horizontal axes can be superimposed; similarly several mills with vertical axes can be placed side by side.

  When the wind turbine, according to any one of the variants of the invention, is installed on a barge floating in the sea, in strong storms, with swirling winds, the transverse forces on the wind power device itself with its fairing as well as on the vertical tail (12), necessarily large, could capsize the barge. To counter the capsizing torque of such a barge, it can be provided, according to the invention, with a ballast (21) at the end of a keel (22), the mass and the depth under the hull being calculated to provide sufficient righting torque to counter the capsizing torque for extreme 5 crosswinds. This ballast at great depth inducing a very large draft, it can, still according to the invention, be retractable to allow the barge to navigate in shallow water when it is launched or for fairing operations.

  Thus a barge with a crosswind surface of 5000 m2 with a thrust center at 70 m high, for a lateral component of the wind of 80 30 knots, giving a force of 1000 N / m2, will undergo a capsizing torque of 5000 x 70 x 1000 = 35.107 Newton x meter. At the end of a 35 m keel (22) the ballast should therefore be approximately 1000 tonnes. Advantageously from the economic point of view, this ballast can be made of concrete. - 6

  Whatever their technique, the moving parts (1) drive electric generators (23). Electrical energy can be removed either by alternating current after voltage rise by transformers, or by direct current.

  An additional advantage of the invention resides in the fact that in very strong winds, the panels (3) and (7) can be positioned so as to have only a small opening and thus continue to produce energy, whereas in the old solutions, we are forced to stop the installation and to feather the propeller blades.

  Still according to the invention, when the installation is placed on the surface of the sea, either located in shallow water, or placed on a floating barge, it can advantageously be fitted at the front with a system (24 ) recovery of wave energy. This system, without being limiting, can be constituted by a series of basins (25) placed at different heights. Sealing plates (26) are positioned by servos at the optimum height so that it is the highest possible t 5 pool which is filled by the waves. Non-return valves (27) prevent water from leaving the basins. A tilted pan (28) allows the waves to rush up. The water then flows from the basins through turbines (29) driving electric generators (30).

  Still according to the invention and without being limiting, another possible system for recovering wave energy consists of floats (31) held by arms (32). The alternating movement generated by the raising and lowering of the floats in the waves is recovered either by a connecting rod assembly or by a rack system to drive the generators in rotation (30).

  Still according to the invention, the platform (10) can carry a flywheel 25 (33) enabling energy to be stored in order to restore it at appropriate times.

  In the case of a barge at sea, to evacuate the electrical energy produced by the wind turbine, by the system for recovering water from waves or else drawn from the flywheel, an electric cable can, depending on the invention, exit by the mooring pin (14), which allows the barge to turn according to the wind without constraining the 3 O electric cable.

  Another solution, still according to the invention, for evacuating the above energy, is to transform it on board the platform (10) into hydrogen, by electrolysis, for example, without this being limiting.

Claims (13)

REVENDICA'i lONs i Device intended to collect the energy of the vunt. comprising rotating parts (1) in the form of aerodynamic surfaces ca.racterized by the fact that the rotating parts (1) are surrounded by a fairing causing a 'efr.deVenturi at the location of said rotated parts. (L) and characterized by 5.l1 fail that the energy of the collected wind is transformed into electrical energy.   2) Device according to claim i characterized by the fact that the fairing is composed of a fixed part (2) and of articulated panels (3), (5) and (7) with adjustable positioning.   3) Device according to claim I characterized in that it is installed 10 on a flat platform (10) provided with a pivot (i 1) allowing it to be oriented towards the wind.   4) Device according to claim 3 characterized by the ftait that the orientation facing the wind is obtained through unl control servo by a ia wind direction sensor.   5) Device according to- claims I and 2, characterized in that it is installed on a floating barge.   6) Device according to any of the preceding claims characterized by the fact that the orientation facing the wind is obtained by the effect of the wind on a vertical tailplane (12).   7) Device according to claim 6 characterized in that the tail (12) is provided Uie rudders (15) of vcrtical axis to ensure precise control of the orientation.   8) Device according to one clueicnque these preceding claims characterized ie ie that the rotating parts are solnt of turbines i 2 S blades close in replaccimenet of ciassiclues propellers.   9) Device according to any one of claims 1 to 6 characterized by the fact that the rotating part uses the mill technique whose axis is perpendicular to the direction of the vetnt and that is also characterized by the fact that the blades (18 ) according to this mill technique have an airplane wing profile 30.   10) Device according to claim 9 characterized by the fact that each wing - 8 can rotate around an axis (_9) to present an optimal angle of attack in each of its positions during the rotation of the mill and finally characterized by the fact that each blade in the shape of an airplane wing can be equipped with high-lift flaps (20) with variable deflection.   II) Device according to any one of the preceding claims, characterized in that the articulated panels (3), (5) and (7) of the fairing can tilt to form a shield protecting the moving parts in the event of dangerous wind.   12) Device according to any one of the preceding claims I0 characterized in that it is provided at the front with a device (24) for recovering the energy of the waves when it is installed 'on the bottom of the sea when it is shallow as well as on floating barges 13) Device according to claim 12 characterized in that it comprises a series of superimposed basins (25), which the waves fill by passing 5 over the shutter plates (26), positioned by slaves so that it is the highest basin which is filled and further characterized by the fact that an inclined pan (28) allows the waves to start upward and finally characterized by the fact that the basins (25) pour their water into turbines driving electric 2.0 generators.   14) Device according to claim 12 characterized in that it comprises floats (30) held by arms (31) whose movements caused by the waves cause electric generators.   15) Device according to any one of the preceding claims 25, characterized in that it comprises on board a flywheel (33) intended to store the energy.   16) Device according to any one of claims-.5 to 15 characterized by fact. that it is provided with a pin (14) ercaracléresé equaloeen by lc fact that the energy produced on board a barge is evacuated by 30, an electric cable leaving by the pin (14) anchor 17) Device according to claims 1 and 2 characterized by the fact that the energy produced is transformed on site into hydrogen.