FR2868483A1 - Quadri-rotor windmill for windmill park, has four respective rotors arranged in upstream and downstream of pivoting structure in respective stages such that assembly of rotors is balanced on vertical pivoting axis - Google Patents

Abstract

The windmill has two rotors (3, 4) arranged in an upstream and downstream of a pivoting structure (1), respectively in one stage and rotors (5, 6) arranged in downstream and upstream of the structure, respectively in another stage, such that assembly of the rotors is balanced on a vertical pivoting axis (7). The assembly naturally orients opposite to the wind direction and can be disoriented automatically by aerodynamic units. An independent claim is also included for offshore or terrestrial windmill park comprising 6 to 60 quadritotor windmill.

Description

The present invention relates to a type of wind turbine with four rotors

  non coaxial grouped on a common support and called quadrotor wind turbine, and more particularly to means intended to facilitate the practical and economic realization of this type of wind turbine and to make the operation safer, more durable and more

productive.

  Four-rotor wind turbine projects have been in existence for a long time, for example Lucien ROMANI in France and Friedrich KLINGER's more recent one in Germany for wind turbines with a capacity of 10 MW, double that of single-rotor wind turbines. powerful to date. We also know a small wind turbine with four rotors built by the Dutch company LAGERWEY and operated for several years.

  The type of quadrotor wind turbine has the advantage of allowing the realization of a wind turbine of a greater power than that of a wind turbine type monorotor without having to use gigantic rotors or very heavy electromechanical conversion devices. For example the four rotors of a quadrotor wind turbine can advantageously replace a single rotor of double diameter with a mass and a total cost of less than half.

  It is less known that the spacing necessary to avoid wake turbulence between two quadrotor turbines being calculated with respect to the diameter of one of the four rotors, these quadrotor turbines may be twice as close to each other at surface swept by the rotors equal that twin diameter wind turbines monorotors. As a result, with a flat surface swept by equal rotors, a wind farm consisting of quadrotors will occupy only a quarter of the surface of a wind farm composed of monorotors.

  However, these advantages have remained to date purely theoretical because there are many uncertainties regarding the best architecture of a quadrotor wind turbine. Balancing the eccentric masses, the arrangement and direction of rotation of the rotors, the orientation of the rotors with respect to the direction of the wind, the synchronization of the four rotors and the four alternators, the problems of vibrations and resonance of all, means of securing in all weathers, the choice of components, and mechanical arrangements are all difficulties requiring a solution and to avoid a host of unfortunate options.

  For example, the assembly of the four rotors is known all upstream of the pivot axis and their assembly all downstream of this pivot axis. In these two arrangements, one or more counterweights must be used to achieve balancing on the pivot axis. The use of fixed pitch rotors by Lucien ROMANI is also known, which simplifies the aerodynamic balancing of the four rotors. More generally known is the use of variable pitch rotors which can be feathered in the event of a storm but which require synchronization and perfect reliability of pitch variation mechanisms.

  One of the accepted ideas for the constitution of a quadrotor wind turbine is to borrow the rotor and the nacelle from a proven monorotor type wind turbine and to mount four specimens at the ends of swinging yards around a mast, or two horizontal fixed yachts rigidly connected to a mast pivoting at its base. It appears from the examination that this seemingly cost-effective method of avoiding the study and manufacture of specific rotors and nacelles is difficult to achieve and does not provide sufficient safety because the operating 'a wind turbine with four rotors are very specific. For example, the blades of the four rotors rotating in the vicinity of each other must not bend or vibrate at the risk of seeing resonance of the entire wind turbine. It is also of interest to simplify access and maintenance as well as to reduce the suspended and gyrating mass of the four nacelles to share a maximum of functions and devices, electrical control, lubrication and cooling generators. The fixed support, preferably of high height must also benefit from stability and rigidity greater than that of conventional vertical supports and tubular poles.

  The invention therefore relates first of all to the general architecture and arrangement of the four rotors of a quadrotor wind turbine characterized in that its four rotors are of a fixed pitch type and that their rotational planes can all be deviated together or erased on command or automatically in the wind bed or in neutral position. To obtain this result the four rotors are arranged on two floors and in two parallel planes on either side of the pivoting structure which surmounts a fixed pylon. By this means, a double birotor with an upstream / downstream arrangement such as EP96 401 818.8-2317 is formed. According to this crossed and balanced arrangement upstream / downstream at one stage and downstream / upstream at the other end, there are four variants whose rotors are contrarotatives supra divergent at one stage and supra convergent at the other. By naming from left to right A and B the rotors of the lower stage and C and D the rotors of the upper stage, we count these four provisions: 1 A upstream B downstream supra convergent C downstream D upstream supra divergent 2 A upstream B downstream supra divergent C downstream D upstream supra convergent 3 A downstream B upstream supra convergent C upstream D downstream supra divergent 4 A downstream B upstream supra divergent C upstream D downstream supra convergent According to these four provisions, the set of pivoting masses is balanced and its center of gravity coincides with the pivot axis. The torques of the four rotors vanish and the winding movements of the four vortices are a kind of aerodynamic gear that reduces vibrations and probably noise. The left / right aerodynamic balance is maintained when two rotors of the same stage are immobilized but the other two rotors are kept in normal operation. Any failure on one of the rotors thus forces to stop only two rotors and causes the loss of only half of the productive.

  The use of fixed pitch rotors is allowed on the one hand by using the passive aerodynamic control of the flow on the extrados of the profiles by the known phenomenon of aerodynamic stall and on the other hand by means of the installation of an electric power capable of absorbing without overheating or racing a higher wind torque during gusts and strong winds. Previous experience in France with a monorotor prototype in which the fixed-pitch wind rotor was 30 m in diameter and was equipped with an alternator with a nominal power of 800 KW demonstrated that it was possible to produce power without damage. 1000 KW in wind of 20 m / second. In offshore and in very good terrestrial sites, this rate of electrical equipment of approximately 1250 W per m2 of rotor makes it possible to exploit much better the wind field.

  According to the invention, it is preferable to use three-bladed or two-bladed rotors whose blades are biplanes. The two twisted planes of each blade join in a single fork-shaped foot and are connected by an end hook and by one or more profiled and inclined members, for example FR9700521 5. According to the invention, these connecting members of Preferably, single poles can be twisted, their ends bending at different angles of + or 15% at both upstream and downstream planes. These frames are thus more rigid and in normal regime counteract less air flows of different directions on the intrados of the downstream plane (thrust) and the extrados of the upstream plane (lift). This twisting of the chords and their profiles are also designed to generate aerodynamic drag from a certain speed and thus limit the risk of runaway rotors. Different strings and profiles of the two planes of a biplane blade are known from Honnef. According to another characteristic of the invention, at the same given distance from the hub, different incidences of 0.5% to 5% will also be given. downstream and upstream so they do not drop out at the same time.

  These lightweight, rigid rotors are easier to carry eccentrically and can have high angular velocity and exploit high winds without fear of vibration. According to another characteristic of the invention, the biplane blades may consist of several sections of reduced size in S-shaped cuts, each section may comprise an upstream part of the plane, a downstream part of the plane and all or part of one or more connecting members. All these sections can be easily and rigidly assembled, for example by means of rods.

  The four alternators with central control are preferably asynchronous double feed type and 3 rotational speeds for example 1500 revolutions / minute, 2000 and 2500 TM corresponding to three wind regimes. These alternators are equipped with a known power electronics AC / DC / AC.

  When the rotational speed of the four alternators and the four rotors is synchronized, the aerodynamic operating characteristics of the rotors are the same and they are naturally oriented together in the direction of the wind, all the more easily as their contra rotation cancels the couples of these rotating bodies. When the direction of the wind changes the four rotors are first attacked obliquely by the wind then these rotors tend to come naturally facing the wind.

  This means of purely aerodynamic orientation is called free yaw orientation and allows a gain in efficiency compared to the discontinuous force and mechanized orientation and a very significant reduction of the torsional forces of the support.

  The set of four rotors being mounted on a common pivoting support, this pivot is the most mechanically stressed part of the entire quadrotor wind turbine. On the other hand, seen the continual and more or less rapid changes in yaw orientation oscillations of the moving part must absolutely be attenuated. One of the solutions envisaged by the invention is the installation of electromagnets with variable magnetic flux and controlled by the intensity of the excitation current of the coils of the electromagnets. This device makes it possible to brake and dampen oscillations of the pivoting structure without any wear.

  Several arrangements of the pivot can be employed derived from each of the known slewing mechanisms of the large capacity cranes. For example the pivoting structure can be constituted as a crane lantern resting on a plate at the top of a fixed shaft embedded in the upper part of the fixed pylon and which extends, and be guided laterally in the lower part around the barrel. In this case the sensitivity of the pivoting mechanism is very high. The swivel structure can also rest on a ring of rollers around the base of the fixed and only be guided at its top. The pivoting structure can still extend axially inside the fixed tower by a longer or shorter and pivot on a platen or a ring of strongly supported rollers. In the latter case, a large cylindrical float integral with the shaft will be able to offshore to relieve the very large load supported.

  Before their mechanical immobilization by brakes, it is already possible to avoid the wind and even to stop the fixed pitch rotors in the wind bed by reducing the rotational speed of alternators on the same side (A and C or B and D) for example from 2500 to 2000 rpm. The modification of the aerodynamic operating characteristics of the two rotors concerned then creates a moment that rotates all four rotors. The return to the wind is made in the same way, one or two rotors then acting as driving propeller and creating a moment capable of bringing the four rotors face the wind. Another lace control means is used, one or more flaps articulated on the pivoting support and creating a asymmetry of drag and a moment of rotation.

  The upstream / downstream and downstream / upstream arrangement of the four rotors allows the partial superposition of the disks swept by these rotors. By this means it is possible to substantially reduce the dimensions and the mass of the pivoting support structure.

  It was discovered by wind tunnel tests that a partial superposition of 1/5 to 1/6 of the radii of two counter-rotating rotors located in two parallel planes spaced about 1 / second of the diameter of a rotor total efficiency gain of the two rotors of about 3% to 5% with respect to the same two isolated rotors. It is also known that the efficiency of two counter-rotating rotors located side by side and on either side of a smooth cylindrical or conical axial support is about 10% higher than that of the same two isolated rotors.

  According to another characteristic of the invention, the four rotors of the quadrotor wind turbine are carried by a pivoting structure in the general shape of a four-pointed star whose geometrical shape, the proportions and the dimensions are chosen so that the four rotors attached to the four vertices of the star structure can be superimposed partially from 1/6 to 1/5 of their radius. According to this characteristic, the rotors A and B are arranged substantially tangentially and on either side of the fixed axial pylon in front view, the rotors A and C are superimposed at a distance, C and D are also superimposed at a distance as well as D and B The fixed axial pylon rises from the ground or the seabed substantially up to the height of the axes of the rotors A and B. This pylon preferably has a form of equal strength of the Eiffel tower type, for example at eight feet. and eight triangulated faces. It is fixed in the ground by metal piles. By this means a very stable and rigid support is made by avoiding the use of the large concrete stabilizing masses of the usual wind turbines.

  The swivel structure is formed of several long triangulated and intersecting beams. This structure without cable or hanger presents less risk of vibrations than that of some previous quadrotor projects.

  The tubular chords of the ladder beam consist of two shells of steel sheet internally stiffened by pairs and heddles. It is desirable for the shafts, substantially parallel to one another, to be fixed very rigidly to this structure, for example each being held by two convergent ladder beams forming a bearing spire.

  These four arrows can each be overhanging and away from 1 to 10 of the imaginary transverse axis of the quadrotor wind turbine, with the result of increasing the distance between the planes of the downstream and upstream rotors and to move the end of the blades of the frames of the structure.

  The multipliers of the rotational speed of wind turbine rotors generally consist of several planetary gear trains planetary very heavy and expensive. We also know the light and inexpensive sprocket and gearbox multiplier of the Danish wind turbine from GEDSER. To this day a chain multiplier did not seem compact enough to enter the closed steerable gondola of a large single-rotor wind turbine.

  In the case of a quadrotor wind turbine, it is advantageous to use four external chain multipliers to constitute the first multiplication stage, for example in a ratio of 1 × 6 and four nacelles fixed to the pivoting structure and off-axis containing the stage. rapid multiplication gear in a ratio for example 1 to 12 coupled to the alternator. The four toothed wheels which are integral with the four hubs of the rotors may have, for example, a tenth of a diameter of the rotors and be perforated in an aluminum alloy with added steel teeth. Chains with high tensile strength are made of stainless steel or other materials with self-lubricating properties. These means that lighten the swivel load greatly improve the feasibility of a quadrotor wind turbine.

  Another specific point of the quadrotor turbine is the mechanical resistance of the rotor shafts which can be subjected to gyroscopic forces when the support pivots and the rotors tend to maintain their orientation. According to the invention, fixed and hollow shafts of strong section are used that are integral with the pivoting structure and participate in its resistance. As we have seen, these four fixed shafts are horizontal and can form an angle of 1 to 10 relative to their bearing spire. The hubs of the fixed pitch rotors rotate freely on bearings around the fixed shafts.

  According to another characteristic of the invention, the four alternators are cooled by a closed circuit of pulsed air and the ribbed tubular ribs of the ladder beam act as air ducts and heat exchangers between the internal air and the outside.

  These listed and nonlimiting means and arrangements are specifically adapted to the production of quadrotor wind turbines with an installed power of, for example, between 10 MW and 20 MW, the electrical installation rate of which is approximately 1250 W per square meter of surface area. swept by a rotor. In this power range, the diameter of the rotors is between 55m and 70m in diameter.

  The invention also relates to an ideal wind farm made in successive installments, installed offshore 10 or 20 km from the coast on substantially horizontal funds from 10 to 30m deep. Quad-turbine wind turbines of 20 MW each are installed, equipped with four rotors 70 m in diameter and spaced from each other by a space of 7 times the diameter of a rotor is arranged every 500 m.

  First, a technical center connected to the coast is installed by submarine AC or DC cable. In this center are all the facilities necessary for the control, maintenance and distribution of electricity production. A first installment of 6 wind turbines is installed, ie 120 MW forming a hexagon of 500m on one side, then a second section of 12 turbines totaling 240 MW on a concentric hexagon of 1000m on one side, then possibly a third slice of 18 machines and 350MW and one fourth of 24 and 480 MW. On this basis we can create a wind farm of 60 quadrotor wind turbines totaling 1200 MW in a hexagonal perimeter of 2000m side. This hexagonal geometry is the most favorable to receive and exploit the winds blowing from all directions. This wind-power plant will preferably be associated with a gas-turbine electric unit installed on the ground and with a power of a quarter, for example, 300 MW, in order to provide the installation with guaranteed and predictable minimum power.

  Quad-rotor wind turbines are preferably built in a shipyard or coastal site specifically designed as a construction site. First we bring on a floating barge the recumbent pylon and then it is poured and straightened by a high capacity crane on a pontoon. The pivoting structure is brought to a barge and lifted and laid with the same crane. The nacelles and the rotors are then brought separately and successively, which are raised and assembled by means of hoists carried by the pivoting structure in the absence of the crane. This lifting is facilitated by the fact that the barge that brings the nacelles or rotors can be positioned vertically and under the pivoting structure.

  In the case of a terrestrial installation, especially of underserved sites or the transport of large metal elements is problematic the fixed tower of the quadrotor is realized in situ in thin veil of reinforced concrete in a form with double curvature of equal broad-based resistance and sharpening upward. In this case the pivoting structure is made in transportable short sections assembled on site while the limited length of the blades in whole or in sections and the compactness of the nacelles of reduced mass facilitate their transport.

  Certain elements and details of the invention intended for the quadrotor can find an application elsewhere. For example, chain drives, fixed axes, tower arrangement and single steerable beam structure and forced air cooling are applicable to any birotor or multirotor wind turbine.

  Beyond their known application to birotors, the downstream upstream architectural arrangement of the rotors, their contra rotation and the principles of synchronization and aerodynamic control by the generators or by shutter can make it possible to develop any multirotor wind turbine with a rotating structure. single comprising an even number of rotor.

  The biplane blades with twisted connecting members described are also suitable for a conventional monorotor wind turbine with variable or fixed pitch.

  Finally, we can advantageously deploy any type of wind turbine, especially offshore in the hexagonal and concentric arrangement described. The invention will be better understood by consulting the Description and the figures which follow.

  Figure 1 is a front view of the quadrotor wind turbine.

  Figure 2 is a side view of the steerable part and rotors of the same quadrotor wind turbine.

  Figure 3 is a top view of the same quadrotor wind turbine.

  Figure 4 is a schematic detail view in front section of a fixed arrangement of the fut 17.

  FIG. 5 is a schematic detail view in front section of a mobile arrangement of the drum 17.

  Figure 6 is a perspective view of the pivoting structure 1 and the arrangement of the four rotors of the quadrotor wind turbine.

  FIG. 7 is a detailed and perspective view of the arrangement of one of the four rotors at the end of an arrow of the quadrotor turbine, specifically of the lower upstream rotor C 3, of the drive mechanism of FIG. an alternator, and an arrangement of the flap 46.

  Figure 8 is a perspective view of one of the biplane blades 23 of the quadrotor wind turbine.

  FIG. 9 is a schematic sectional view of a section approximately mid-length of a biplane blade such as 23.

  FIG. 10 is a detail and perspective view of a twisted chord 26 bonding the two planes of a biplane blade such as 23.

  FIG. 11 is a schematic axial and top view of the same twisted chord 26. of a biplane blade such as 23.

  Figure 12 is a detail view in perspective of the hook 261 linking the two planes to the end of a biplane blade such as 23.

  Figure 13 is an overall perspective view of an offshore wind farm 99 consisting of quad-rotor wind turbines and connected to the coast and a gas-fired power plant.

  DESCRIPTION OF THE QUADRIROTOR WIND

  The quadrotor 70 wind turbine is characterized first and foremost by its general architecture and the layout of its four rotors and secondly by its mode of orientation and safety in the wind bed that allows the use of pitch rotors. fixed and better exploitation of strong winds.

  The rotors 3, 4, 5 and 6 are arranged on two stages at the four corners 8, 9, 10 and 11 of a four-branched star-shaped pivot structure 1 formed by five beam ladders 12, 13, 14, 15 and 16 intertwined with each other and with a fixed or pivoting axial shaft 17 (FIGS. 5 and 6).

  This pivoting structure 1 is carried on a fixed tower 2 octopode Tower type broad-base and tapering towards its top, which has a profile of equal strength and each of the eight feet is fixed by a pile 19 beaten in the ground. In a variant, and while maintaining the same general shape, this fixed pylon can be made in continuous and thin veil of reinforced concrete.

  This fixed pylon 2 can be surmounted by an axial shaft 17 integral with it and penetrating into the pivotingel structure. The pivoting structure 1 can then either be carried suspended and turn on a rotary bearing 211 located at the top of the shaft 17 and be guided by vertical axis rollers 221 disposed around the base of the drum 17, or be carried at the beam scale 12 on a ring of rollers 220 arranged around the base of the drum 17 and then only be guided to the top of the fixed shaft instead of 211.

  In another case, the axial shaft 17 is secured to the pivoting structure 1 and penetrates 15 to 30 m into the upper part of the fixed pylon 2 to bear on a rotary support 210 strongly supported by the fixed pylon 2, and 17 is always guided by vertical axis rollers 221.

  Electromagnets 20 with magnetic flux controlled by coils are located between the fixed pylon 2 and the pivoting structure 1 to brake and control the yaw oscillations of this pivoting structure 1.

  The pivoting structure 1 balanced around the central axis 7 carries the four rotors A 3, B 4, C 5 and D 6 in a downstream / upstream configuration at each stage. This arrangement is reversed between one floor and the other. Thus the rotor A 3 is upstream to the first stage, and the rotor B 4 downstream to the first stage, the rotor C 5 downstream to the second stage and the rotor D 6 upstream of the second stage.

  The rotors 3, 4, 5 and 6 are all of the same diameter for example 50m to 70m or at least the same diameter at each floor and are counter-rotating two by two at the same floor and also with respect to the rotor of the other floor located on the same side. The upper rotors C 5 and D 6 are above convergent and the lower rotors A 3 and B 2 are above divergent.

  The four hubs 29, 30, 31 and 32 of the four rotors 3,4,5 and 6 each rotate on a bearing around their fixed horizontal shaft 33, 34, 35 or 36. These fixed shafts located at the vertices 8, 9, 10 and 11 are substantially parallel to each other, integral with the pivoting structure 1 and each of them is held rigidly by two convergent ladder beams: 8 is held by 12 and 15, 9 is held by 12 and 16, 10 by 13 and 16 and 11 by 14and15.

  The four rotors 3, 4, 5 and 6 therefore rotate in substantially parallel planes, ie two main planes, the first common to the rotors A 3 and D 6 upstream and the other common to the downstream rotors B 4 and C 5, either in four distinct planes, two downstream and two upstream of 1.

  In order to move the end of the blades 23 away from the rotors 1, 2, 3 and 4 of the structure 1, each ladder beam 12, 13, 14, 16 and 16 may tend to move towards its end of the horizontal axis imaginary 18 from 1 to 7 to increase the overhang of the rotor 1, 2, 3, or 4. This angle also increases the distance between downstream planes and upstream plans. It follows that each of the ladder beams forms an angle greater than 90 with the fixed shaft 33, 34, 35, or 36 that it carries so that the latter is horizontal.

  The disks of the lower rotors 3 and 4 are substantially tangential to the fixed pylon 2 while the distance between the fixed axes 35 and 36 of the upper stage, 33 and 35 on the port side and 34 and 36 on the other side, identical , is only about 4/5 or 5/6 of the diameter of a rotor such as 3. It follows that the scanned discs of rotors C 5 and D 6, A 3 and C 5 and B 4 and D 6 overlap partially in front view of about 1/5 to 1/6 of the radius of a rotor. This reciprocal overlap of the discs is easily achieved thanks to the distance between downstream and upstream planes which eliminates any risk of the blades colliding.

  The four alternators 41, 42, 43 and 44 have an installed capacity of approximately 1250 Watts per m2 of surface swept by the rotors, ie 5 MW per rotor of 70 m in diameter and 20 MW in total per quadrotor wind turbine 70, whose nominal power is obtained at a wind speed of about 17 mlsec. All upstream alternators 41 and 43 as downstream 42 and 44 however turn in the same direction because of the contra rotation of the rotors apparent in front view.

  The alternators 41, 42, 43 and 44 are housed in closed gondolas and firmly attached to the ladder beam, 12 and 15 in the case of 41, in an eccentric position relative to the fixed shafts 33, 34, 35 and 36. Each alternator 41, 42, 43 or 44 is coupled to its rotor 3, 4, 5, or 6 via a planetary gearbox 40 driven by a pinion gear 38 driven by a chain 39 transmitting the force of another gear pinion of larger diameter 37 whose shape is that of a perforated wheel 45 and which rotates about the fixed shaft 33, 34, 35 or 36 integral with the hub 29, 30, 31 or 32 of each rotor 3, 4, 5 or 6. The four sets of pinions 37 and 38 constitute a multiplier first stage, 37 having a diameter of about 5% to 10% of that of a rotor such as 3 and six times that of 39.

  The alternators 41, 42, 43 and 44 are variable speed and are cooled by the circulation of pulsed air inside the pivoting structure 1, the chords of the ladder beams 12, 13, 14, 15 and 16 playing role of heat exchangers between indoor air at 1 and outside. This system also cools the gearboxes 40, the brakes, etc.

  The geared gear transmission 37 and 38, chain 39 and planetary gear 40 operates in both directions, transmitting energy to the rotors 41 or allowing the alternators 41 to drive the rotors 3, 4, 5 and 6 together. or separately.

  It results from the configuration of the pivoting structure 1 and the upstream / downstream assembly of the rotors 3, 4, 5 and 6, their transmissions 37, 38, 39 and 40 and their alternators 41 that all the masses of the moving parts of 70 are balanced on the vertical axis 7 and on the rotating supports 210, 211 or on the ring of rollers 220. Rotors 3, 4, 5 and 6 stopped and blades 23 placed in a port / starboard symmetrical position with respect to 7, the aerodynamic drag of this pivoting assembly and also the shaft 17 is also balanced on the vertical axis 7, and the assembly is naturally oriented and permanently facing the wind.

  This aerodynamic balance is maintained during normal operation of the quadrotor wind turbine 70 by the synchronization of the four alternators 41, 42, 43 and 44 which causes the rotors 3, 4, 5 and 6 to rotate in a synchronized and counter-rotating manner in front view and to constantly present a symmetrical scale although variable since always centered on the axis 7. At all operating speeds the rotors 3, 4, 5 and 6, whose couples are neutralized and the structure 1 are thus naturally oriented and permanently face in the wind, these yaw movements can however be controlled, braked or even prohibited by the magnetic flux controlled in the windings of the electromagnets 20 placed between the fixed pylon 2 and the pivoting structure 1.

  The aerodynamic balance is maintained with a rotation speed of alternators 41 and rotors different from one stage to another but identical to the same stage for example A 3 and B 4 synchronized and C 5 and D 6 synchronized. Any break in aerodynamic port / starboard symmetry on the vertical axis 7, for example a synchronization fault of the alternators 41 and thus the modification of the drag of the rotors leads the pivoting structure 1 and the rotors 3, 4, 5 and 6 to put skewed with respect to the direction of the wind. It is also possible to control the desynchronization of one or more alternators 40 to orient the structure 1 as well as the rotors 3, 4, 5 and 6 with respect to the direction of the wind or in the absence of wind, for example by using one or two rotors as driving propellers producing a couple.

  At least one articulated flap 46 of a wing surface corresponding for example to 2% of the surface swept by a rotor such as 3 is positioned near the end of one of the ladder beams 12, 13, 14, 15 or 16, preferably close to an upstream rotor and as far as possible from 7, for example on the ladder beam 15. This profiled flap does not generate in normal operation aerodynamic drag 70 but can be deployed on command or automatically for example in pivoting about its central axis 48 under the action for example of a pneumatic cylinder 47 or springs to provide a maximum wind grip. In sufficient wind, the drag of the flap 46 more or less deployed may force the pivoting structure 1 and the rotors 3, 4, 5 and 6 stopped or in operation to take a position partially or totally crooked with respect to the wind direction. Maintained fully deployed, the flap 46 acts as a drift and can hold the rotors 3, 4, 5 and 6 and the pivoting structure 1 completely in the wind bed in the safety position, always 90 of its changing direction.

  In this so-called cloaking safety position by analogy with the navigation, the fixed pitch rotors 3, 4, 5 and 6 are erased and their blades 23 offer a minimum hold to the wind.

  the shutter 46 can operate independently regardless of the power supply of the quadrotor wind turbine 70. The deployment of 46 to rotate 1, 3, 4, 5 and 6 in the safety position is triggered for example in case of overspeed, tornado, any incident or network stall and will be accompanied by an interruption of the magnetic flux of the electromagnets 20 which could counteract its action.

  The rotors 3, 4, 5 and 6 with a fixed pitch of the quadrotor wind turbine 70 are normally three-bladed but may also be two-bladed and are preferably, but without limitation, equipped with biplane blades 23. Two versions of this blade biplane 23, exact mirror one of the other but apart from that rigorously identical fit the rotors 3 and 6 on the one hand and 4 and 5 on the other hand depending on whether these rotors rotate in the direction or in the opposite direction of the clockwise and it would be the same for some type of blade for example conventional monoplane which one wants to equip the wind quadrotor 70, and whose profile can be of the type NACA 23.021 A blade biplane 23 consists of two planes downstream profiles 24 and upstream 25 Tapered and twisted substantially identical joining together at the foot of blade 262 and interconnected by a hook 261 blade end and by several inclined members 26. These members 26 to the number of such three so twisted profiles. That is, the end profile of each chord 26 which joins the intrados of the downstream plane 24 forms an angle of plus or minus 92% or more with the leading edge of 24 and is therefore not perpendicular. to it, while the profile of the other end of each frame 26 which joins the extrados of the upstream plane 24 also forms with the leading edge of the upstream plane 25 an angle of the same order but inverse, as can be seen in FIG. looking axially at a frame 26.

  This twisting and the profiles of the chords 26 are designed to fit in a normal rotation of a rotor such as the direction of the flow of the different air on the extrados of the upstream plane 25 and the intrados of the downstream plane. 24 and also, beyond an air flow rate of 70 m / s to generate a large turbulent drag that opposes the runaway of rotors 3, 4, 5 or 6.

  The profile 27 of the downstream plane 24 and 28 of the upstream plane 25 may be identical, for example biconvex laminar type, whose thickness is located at 40% of the rope for example NACA 65.213, or supercritical laminar type GA 8 (W -1) from NASA. At a given section of the blade 23, these planes 24 and 25 may have a different pitch for example of 1 or more so that their aerodynamic stall does not occur at the same time.

  Each biplane blade 23 may be monobloc or consists of two or more sections, firmly assembled together in S-shaped cuts 231 for example by means of rods. Each of these sections of the blade 23 may comprise part of the upstream plane 25, part of the downstream plane 24 and all or part of one or more connecting members 26. The end hook 261 may also form a section of 23 .

  The quadrotor wind turbines 70, for example of 20 MW each, will be installed in land park or preferably offshore 99 comprising from 6 to 60 quadrotor wind turbines 70 arranged at regular intervals of a distance equal to seven times the diameter of a rotor 3 of the wind turbine. 70 for example 500m, according to a central hexagon 50 and other concentric hexagons 51 and connected by a network 72 consisting of six quarters to a technical center 71 of command and maintenance from where the line 73 connecting the park 99 to the coast and the terrestrial electricity network.

  One or more gas turbines 74 are land-based and placed under a direction common to the park 99. This unit 74 with a total power approximately equal to 1/5 of that of the park 99 generates on demand a supplement of electrical production. The synergy of the fleet 99 and the turbines 74, their flexibility of use and their great reactivity make it possible to smooth the productive of the wind turbines 70, help to fulfill the productive commitments to six minutes, guarantees a minimal production in the event of calm or allows usefully respond to an unexpected surge in network demand.

Claims (28)

  1) Quadrotor wind turbine of the type according to which four rotors, non-coaxial and rotating in substantially parallel planes, are fixed on a common pivoting structure (1) with a vertical axis which is carried on a fixed pylon (2), and characterized in that two only rotors such as A (3) and D (6) are attached upstream of the pivoting structure (1) and the two other rotors only such as B (4) and C (5) are attached downstream of this structure pivoting (1), that the four rotors A (3), B (4), C (5) and D (6) are arranged on two stages and in an inverted configuration at each stage, for example upstream / downstream to a stage and downstream / upstream to the other stage, that all four rotors is balanced on the vertical pivot axis (7), that this set is naturally oriented towards the direction of the wind and that it can be disoriented on command or automatically by aerodynamic means.   2) quadrotor wind turbine according to claim 1 characterized in that the two rotors of the first stage such as A (3) and B (4) are counter-rotating, for example supra divergent and that the two rotors C (5) and D (6) the second stage are counter-rotating and supra-convergent and that according to these directions of rotation, the four rotors are counter-rotating two by two horizontally and vertically.   3) quadrotor wind turbine according to claims 1 and 2 characterized in that the four rotors are arranged and rotate according to one of the following four configurations 1 A upstream B downstream supra convergent C downstream D upstream supra divergent 2 A upstream B in downstream supra divergent C downstream D upstream supra convergent 3 A downstream B upstream supra convergent C upstream D downstream supra divergent 4 A downstream B upstream supra divergent C upstream D downstream supra convergent 4) quadrotor wind turbine according to claims 1,2, and 3 characterized in that the four rotors A (3), B (4), C (5) and D (6) are fixed to the four vertices (8), (9) ), (10) and (II) of a metal four-point star-shaped pivotal structure formed mainly by the intercrossing of five ladder beams (12), (13), (14), (15) and ( 16) and a vertical one (17).   5) A quadrotor wind turbine according to claims 1,2,3 and 4 characterized in that the rotors which are upstream of the pivoting structure for example A (3) and D (6) rotate substantially in the same plane, and the two rotors which are downstream for example B (4) and C (5) rotate substantially in another plane, than the substantially parallel rotational planes of the rotors A (3), B (4), C (5) and D (6) each form an angle of 1% to 7% with the beam or beams which each carry them, and each of these beams moves towards its end of the transverse imaginary axis (18).   6) quadrotor wind turbine according to claims 1, 2, 3 and 4 characterized in that the scanned discs of the two rotor A (3) and B (4) of the lower stage are substantially tangential to the fixed pylon (2) while the distance between the axes (33) and (35) of the port side rotors A (3) and C (5), (34) and (36) of the starboard side (B) (4) and D (6) rotors (35). ) and (36) rotors C (5) and D (6) of the identical upper stage are equal to only 4/5 or 5/6 of the diameter of a rotor 3, 4, 5 or 6 and that the scanned disks of A (3) and C (5), B (4) and D (6) and C (5) and D (6) thus overlap partially in front view.   7) quadrotor wind turbine according to claims 1 and 4 characterized in that the pivoting movable structure (1) is carried by a fixed pylon (2) made of metal frame whose base is polygonal and which has a profile of equal resistance tower type Eiffel, and that this pylon (2) is fixed by piles (19) in the firm ground or in the seabed.   8) A quadrotor wind turbine according to claims 1 and 4, the fixed pylon (2) has a geometry with double curvature and profile of equal strength and is made of reinforced concrete.   9) A quadrotor wind turbine according to claims 1 and 4 characterized in that electromagnets (20) with magnetic flux controlled by coils are located between the fixed pylon (2) and the pivoting structure (1) and that these electromagnets (20) allow to brake and dampen the yaw oscillations of this pivoting structure (1) and the four rotors (3), (4), (5) and (6).   10) Quadrotor wind turbine according to claims 1,4,7 and 8 characterized in that the ftt (17) integral with (1) penetrates from 15 to 30m in the fixed pylon (2) and pivots on a rotary support (210) or that (17) fixed is integral with the pylon (2) in which case the load of (1) rests and pivots either at the top of (17) on a rotary support (211) or around the base of (17) on a ring of rollers (220), (1) being always guided by rollers with vertical axis (221) placed for example at the top of (2).   11) A quadrotor wind turbine according to claim 1 characterized in that the four rotors such as A (3), B (4), C (5) and D (6) are of the two-bladed or three-bladed type with fixed pitch.   12) quadrotor wind turbine according to claims 1 and 11 characterized in that the blades (23) of its rotors 3, 4, 5 and 6 are of the biplane type, each blade (23) consists of two planes profiled, tapered and twisted downstream (24) and upstream (25) connected to each other at the blade root (262), by a hook at the end of the blade (261) and by ribs (26) and that the twisting and the profiles of these members (26) are designed to fit the different directional flow on the 24-sided surface and the 25-sided extrados in normal operation and to generate a large turbulent drag opposing runaway of the rotors from a flow rate of 70m / s.   13) quadrotor wind turbine according to claims 1,11 and 12 characterized in that the profiles (27) and (28) of the planes (24) and (25) are biconvex, the laminar type whose maximum thickness is located at 40% example NACA 65.213, or supercritical laminar GA 8 (W-1) from NASA.   14) A quadrotor wind turbine according to claims 1 and 11 characterized in that the monoplane blades, twisted and tapered of its rotors have a profile of NACA type 23.021.   15) quadrotor wind turbine according to claims 1,11 and 12 characterized in that the planes (24) and (25) of one of its blade biplanes (23) have between them at a given section of the blade (23) a different setting for example of 1 and that (23) is formed of separately transportable sections according to cuts S (231) cutting the blade root (262), the downstream plane (24), upstream (25), the ribs (26). ) or the hook (261). 16) A quadrotor wind turbine according to claims 1,2 and 3 characterized in that the two upstream and downstream rotors for example A (3) and B (4) of the same stage can operate separately from the two rotors stopped for example C (5) and D (6) of the other stage and that the pivoting assembly (1), (3), (4), (5) and (6) remains balanced and manoeuvrable.   17) quadrotor wind turbine according to claims 1,2,3 and 16 characterized in that the rotational speeds of the rotors of a stage for example A (3) and B (4) and the other stage for example C (5). ) and D (6) can be differentiated and that the set (1), (3), (4), (5) and (6) remains balanced and manoeuvrable.   18) A quadrotor wind turbine according to claim 1 and 11 characterized in that the four hubs (29), (30), (31) and (32) of the four rotors rotate on bearings around four fixed horizontal shafts (33), ( 34), (35) and (36) substantially parallel to each other and integral with the pivoting structure (1).   19) A quadrotor wind turbine according to claims 1 and 18, the four rotors (3), (4), (5) and (6) are coupled to four alternators such as (41) variable rotational speed by means of four transmissions chain gear (37) and (38) chain (39) and four gear boxes (40).   20) quadrotor wind turbine according to claim 1, 18 and 19 characterized in that the toothed gears (37) coaxial with the rotors (3), (4), (5) and (6) are in the form of a perforated wheel (45). ) with a diameter of 5% to 10% of that of the rotors.   21) quadrotor wind turbine according to claim 1 and 4, the four alternators such as (41) are cooled by a pulsed air circuit flowing inside the beam ladders (12), (13), (14), (15). ) and (16) whose internally and possibly externally ribbed ribs serve as a large surface air heat exchanger.   22) Quadrotor wind turbine according to claim 1 characterized in that its installed electrical power is about 1250 W per m2 of surface swept by the rotors and that its nominal power is obtained in wind of about 17 m / second.   23) quadrotor wind turbine according to claim 1 16 and 17 characterized in that the planes of the four rotors (3), (4), (5) and (6) are naturally oriented towards the direction of the wind when the speed of rotation of the four alternators (41), (42), (43) and (44) is synchronized or the same at each stage.   24) A quadrotor wind turbine according to claim 1, 16 and 17, characterized in that the safety and safeguard system of the four fixed pitch rotors (3), (4), (5) and (6) is to rotate on its axis (7) the structure (1) of about 90 and to put the rotation planes of (3), (4), (5) and (6) crosswise with respect to the direction of the wind, for example by modifying electrically the rotational speed of an alternator (41), (42), (43) or (44) and its rotor (3), (4), (5) or (6).   25) quadrotor wind turbine according to claim 1 and 24 characterized in that in the absence of power supply, the structure (1) pivots about 90 on the axis (7) and that the rotational planes of the rotors ( 3), (4), (5) and (6) are skewed relative to the wind direction and are maintained in this safety position by the aerodynamic drag of at least one hinged flap (46), which ( 46) is articulated to one of the ladder beams (12), (13), (14), (15) or (16) and actuated for example by a pneumatic cylinder (47) or springs, and for example switches around from its central axis (48) to form drift.   26) quadrotor wind turbine according to claim 1,16,17 and 24 characterized in that the structure (1) and the four rotors (3), (4), (5) and (6) in the neutral position of backup, are brought back in operating position facing the wind direction by electrically actuating at least one alternator (41), (42), (43) or (44) driving a rotor (3), (4), (5) or (6) who then acts as a driving propeller.   27) A quadrotor wind turbines (70) according to claim 1 with a total power of 10 MW to 20 MW and whose rotors such as (3) have a diameter of 50m to 70m approximately.   28) Offshore or onshore wind farm (99) with an installed capacity of 120 to 1200 MW, characterized in that it comprises from 6 to 60 quadrotor wind turbines (70) according to one of claims 1 to 27 whose spacing ( 77) is about seven times the diameter of one of the rotors (3), said wind turbines being distributed over an interconnection network (72) according to a central hexagon (50) and a variable number of concentric hexagons (51). ) around a common technical center (71) for electrical connection to the coast (73), remote control and maintenance, and that the park (99) of 1200MW falls within a hexagon ( 51) of 2 km of side.