FR3027968A1 - CENTRAL HOULOMOTRICE WITH DEFLECTORS - Google Patents

Abstract

Central (1) wave, which comprises: - a platform (2) semi-submersible provided with at least one box (4) longitudinal extending from a bow to a stern platform (2); - A machine (3) wave mounted on the platform (2) and comprising: o a gantry (20) mounted on the box (4), o at least one float (21, 22) arranged to allow the transformation of energy of the swell in mechanical energy, the float (21, 22) being mounted in rotation on an axis (24) integral with the gantry (20), the float (21, 22) having a bow and a stern (26), at least one deflector (34) mounted on the platform (2) and having an upstream face (35) extending opposite and away from the stern (6) of the float (21, 22) to define therewith a gully (36) for channeling and vertical deviation of the swell.

Description

The invention relates to the field of energy production, and more specifically to the field of producing electrical energy from wave energy. French patent application FR 3,004,223 or its international equivalent VVO 2014/162096 (VVaves Ruiz) is known from a wave power plant comprising: a semi-submersible platform provided with at least one longitudinal box which extends from a bow to a stern of the platform; a wave machine mounted on the platform, this machine comprising: a gantry mounted transversely on the box, at least one float arranged to allow the transformation of the wave energy into mechanical energy, the float being attached to a mounted arm in rotation on a fixed axis of the gantry. In this plant, the upward movement or descent of the float following the swell (which also exerts on the float a horizontal thrust) is converted into electrical energy by means of a transformer (it can be a mechanical system , a hydraulic motor associated with a generator, or a hydroelectric turbine). The architecture of this plant may be satisfactory, but it nevertheless deserves to be improved to optimize energy efficiency, and in particular to increase the angular amplitude of the float (s). To this end, it is proposed a wave power plant, which comprises: a semi-submersible platform provided with at least one longitudinal box which extends from a bow to a stern of the platform; a wave machine mounted on the platform, this machine comprising: a gantry mounted transversely on the box, at least one float arranged to allow the transformation of the wave energy into mechanical energy, the float being fixed to an arm rotatably mounted on a fixed axis of the gantry, the float having a bow facing the bow of the platform and a stern turned towards the stern of the platform, o at least one deflector mounted on the platform, the deflector having an upstream face which extends towards and away from the stern of the float to define with it a narrowing for the channeling and the vertical deviation of the swell. Thanks to the neck and the vertical deviation of the swell, the deflector 10 increases the hydraulic pressure under the float and therefore increases the angular stroke thereof, to the benefit of energy efficiency of the wave machine (and therefore the power plant) . Various additional features may be provided, alone or in combination: the baffle is movably mounted relative to the platform, between an active position in which it extends in the vicinity of the float to define the gut with it, and a position inactive in which it is removed from the float; the baffle is pivotally mounted relative to the platform; The platform comprises at least one vertical wall integral with a box, on which the deflector is fixed; the platform comprises an abutment against which the deflector is applied in the active position; the wave machine comprises several floats arranged in parallel, and a deflector for each float; the floats are mounted in rotation on a common axis; the wave machine comprises at least one upstream float and a downstream float offset from the upstream float towards the stern of the platform; The platform comprises for each float a compartment delimited transversely by longitudinal walls; the platform comprises two longitudinal boxes defining between them a channel, and in that the wave machine comprises at least one float which extends between the boxes; 35 - the platform comprises a stabilizing fin, this fin carrying an anchor point of a mooring attachment of the platform to the seabed, this anchor being offset from the axis of rotation of the float towards the stern ; the wave machine comprises a generator for transforming the mechanical energy of the float (s) into electrical energy.

Other objects and advantages of the invention will become apparent in the light of the description of an embodiment, given hereinafter with reference to the accompanying drawings, in which: FIG. 1 is a perspective view from above of a central unit; wave generator; - Figure 2 is a perspective view from below of the central of Figure 1; Figure 3 is a top view of the central of Figure 1; Figure 4 is a longitudinal sectional view of the central of Figure 3, along the section plane IV-IV; FIG. 5 is a detailed view, on an enlarged scale, of part of the central unit of FIG. 4, according to the inset V; Figure 6 is a longitudinal sectional view of the central of Figure 3, along the section plane VI-VI; Figure 7 is a detail view, on an enlarged scale, of a portion of the central of Figure 6, according to the inset VII; Figure 8 is a partial schematic view showing a power converter equipping the plant, including a ratchet wheel and a gear wheel in direct gear engagement with the ratchet wheel; FIG. 9 is a detailed view of the converter of FIG. 6, according to the inset IX; Fig. 10 is a view similar to Fig. 8, showing a power converter including a ratchet wheel, and a gear wheel in indirect gear engagement with the ratchet wheel, through a reversing gear; Figure 11 is a view similar to Figure 5, illustrating a variant of the central. In Figure 1 is shown a central 1 wave. This plant 1, intended to be installed offshore, comprises a semi-submersible platform 35 2 and a wave machine 3 mounted on the platform 2.

The semi-submersible platform 2 is equipped with at least one elongated floating box 4. In the example shown, the platform 2 is equipped with several elongate floating caissons 4 arranged substantially parallel in a longitudinal direction which, when the central 1 is at sea, corresponds to the main direction of propagation of the swell (represented by the arrows H of Figures 1, 3 and 5). The (or each) box 4 extends from a bow 5 to a stern 6 of the platform 2. More precisely, in the illustrated example, the boxes 4 are two in number and have a parallelepipedal shape, with a rectangular section , a height preferably greater than their width. Thanks to the side walls 5 of the caissons 4, the seawater is channeled in the channel 7 along the main direction of propagation of the swell, which limits the roll movements (or heel) of the platform 2. Each box 4 presents an upper longitudinal edge 8 and an opposite lower longitudinal edge 9 which are respectively emerged and immersed by calm (although abrupt) sea to moderately agitated.

Each box 4 is preferably hollow, and made by assembling metal plates (for example anti-corrosion treated steel), composite material or any other material sufficiently rigid and resistant to bending forces as corrosion. Each box 4 can be stiffened by means of internal ribs, in order to better withstand bending stresses both in the longitudinal plane (especially when the box extends cantilevered at the top of a ridge, or when is carried at both ends by two successive ridges) only in the transverse plane (especially in case of local vortex).

Each box 4 may further be compartmentalized to form ballasts that can be at least partially filled with seawater or drained so as to adjust the waterline. The filling and emptying of the ballasts can be carried out by means of pumps, preferably actuated automatically. This adjustment is preferably made so that the waterline is substantially median on the caissons 4 - in other words so that the draft and the freeboard of the caissons 4 are substantially identical.

As seen in Figures 1 to 4 and 6, the platform 2 comprises, at its stern 6, a floating beam 10 secured to the caissons 4, and which extends transversely connecting them. In addition to a function of coupling and bracing of the caissons 4, and stiffening of the platform 2, the beam 10 performs a float function to keep the stern 6 permanently at sea level. In other words, the stern 6 follows the swell. The beam 10 may have, in longitudinal section (Figure 4) any form, but it is preferable, to optimize its float function, it has a rounded shape, including elliptical (or oval). In addition, the beam may, with respect to the longitudinal direction defined by the box 4, be inclined to, when it is at the top of a ridge, extend substantially horizontally and thus offer a minimum resistance to flow some water.

The platform 2 further comprises at least one stabilizing fin 11 which, at sea, is normally immersed permanently, this fin 11 extending transversely beyond the lower edges of the caissons 4. According to a preferred embodiment illustrated in the figures the fin 11 is closer to the bow 5 than to the stern 6.

The fin 11 extends over only a portion of the length of the platform 2 (typically between 1/5 and 1/10 of this length). The fin 11 has a surface 12 upper or extrados substantially flat, parallel to and facing the lower longitudinal edges 8 of the caissons 4, and a lower face or intrados 13.

As illustrated in FIG. 4, the fin 11 carries a point 14 for anchoring a tether 15 through which the platform 2 can be fixed to the seabed 16. The anchoring of the tether 15 on the fin 11 can automatically orient the platform 2 to the swell, the forces being applied in the axis thereof and ensuring a continuous tension of the mooring 15 The anchoring point 14 is advantageously located on a horizontal axis of articulation of the central unit 1 in its oscillation movements at the mercy of the swell. In this way, the anchor point 14 remains almost fixed.

The fin 11 has a leading edge 17 and a trailing edge 18 which are preferably bevelled or tapered, so as to limit the resistance of the fin 11 to the flow.

The fin 11 is secured to the caissons 4 by means of side walls 19 which extend both longitudinally and vertically projecting from the lower longitudinal edges 9, in the extension of the caissons 4, so that the upper surface 12 s extends at a distance from the lower edges 9 so that the fin 11, located below the caissons 4, is always immersed to a depth sufficient to be protected from the effects of the swell. This results in a stable support of the platform 2 platform thanks to the weight of the water column that overcomes the wing 11, and acts as a damper of the movements of the platform 2, including roll (or bed ). The combined effects of the damper function of the fin 11 and the anchoring of the platform 2 by means of the tether 15 cause the bow 5 of the platform 2 is not very sensitive to the swell and is maintained at a minimum. substantially constant trim.

In contrast, the stern 6 follows the swell thanks to the floatation of the stern ends of the caissons 4 combined with that of the beam 10. Thus, the swell induces on the platform 2 a swinging movement of the stern 6, around a transverse axis passing through the anchoring point 14 of the tether 15.

The wave machine 3 is mounted on the platform 2 in the vicinity of its bow 5. The machine 3 comprises, in the first place, a gantry 20 mounted on the caissons 4 extending transversely between them, and which couples them on the side of their 8 upper edges. The wave machine 3 comprises, secondly, at least one float arranged to allow the transformation of the wave energy into mechanical energy. In the illustrated example, the wave machine 3 comprises several floats that are mobile in rotation with respect to the platform 2, namely an upstream float 21 and a downstream float 22 offset from the upstream float 21 toward the stern 6. Each float 21, 22 is fixed to an arm 23 rotatably mounted on an axis 24 common to the floats 21, 22 and integral with the gantry 20. Each float 21, 22 has a bow 25 facing the bow 5 of the platform 2 and a stern 26 facing towards the stern 6 of the platform 2. According to a preferred embodiment illustrated in the figures, the floats 21, 22 are four in number. The floats 21, 22 are advantageously positioned side by side in the channel 7. In the example shown, the upstream floats 21 are positioned laterally, and adjoin the caissons 4, while the downstream floats 22 are positioned centrally, being located between the floats 21 upstream. The arms 23 of the upstream floats 21 are shorter than the arms 23 of the floats 22 downstream. The wave machine 3 further comprises a converter 27 provided with a motor shaft 28 for converting the oscillations of each float 21, 22 into one-way rotation movement, so as to produce electricity via a generator (not shown) . Each float 21, 22 comprises a bottom 29 and flanks 30 which extend both vertically from the bottom 29, and longitudinally from the bow 25 to the stern 26. According to an embodiment illustrated in particular in the figure 4, the stern 26 of each float 21, 22 has an arcuate profile, to facilitate the flow of water. By shifting the float (s) downstream from the float (s) upstream, the oscillations of the upstream float (s) and the downstream float (s). are not synchronous, each peak first reaching the (s) float (s) upstream 21. Such an asynchrony can distribute the torque effect generated by the floats 21, 22, and therefore reduce at every moment the efforts bending applied to the platform 2 (and more precisely to the caissons 4). This makes it possible to minimize the useful section of the caissons 4 and thus to lighten the platform 2 while decreasing the anchoring forces. These oscillations have been illustrated with the swell by arrows in FIG. 5, both in the direction of the rise (arrow M) and in the direction of the descent (arrow D). The rotational movement of the float 21, 22 is illustrated by the dashed arcuate lines in FIGS. 5, 7 and 11. According to a preferred embodiment illustrated in the figures, the volume in which the floats 21 move, 22 is compartmentalized. More specifically, the platform 2 comprises for each float 21, 22 a compartment 31.

In the case where the wave machine 3 comprises several floats 21, 22, the platform 2 comprises, between the side walls 19, at least one longitudinal wall 32 which extends vertically projecting from the extrados 12 of the fin 11. In the illustrated example, where the wave machine 3 comprises four floats 21, 22, the platform 2 comprises, between the side walls 19, three longitudinal walls 32. Together, the walls 19, 32 longitudinally transversely delimit four compartments 31, namely: two compartments 31 external, each delimited by a side wall 19 and a longitudinal wall 32 and in each of which moves an upstream float 21, two central compartments 31, delimited each by two longitudinal walls 32 and in each of which moves a float 22 downstream. As can be seen in FIGS. 1, 2, 5 and 7, each compartment 31 is also delimited vertically, downwards, by the extrados 12 of the fin 11, while the compartment 31 is open upwards for let the swell freely. The leading edge 17 of the fin 11 is positioned longitudinally so as not to hinder the oscillations of the floats 21, 22. It is conceivable, as in the example illustrated in FIGS. 2 and 3, to provide the edge with attacks a notch 33 at the central compartments 31, so as to limit the mass of the platform 2 and the amount of material required for its manufacture. The longitudinal walls extend for example to a height such that their upper edge extends substantially halfway up the caissons 4, so as to remain relatively neutral vis-à-vis the swell. As illustrated in FIG. 4, the anchoring point 14 of the tether 15 is offset from the axis 24 of rotation of the float (s) 21 or 22 in the direction of the stern 6. This offset is advantageously understood. between 1/10 and 1/4 of the total length of the platform 2. This results in a greater angular amplitude A of the natural oscillations of the platform 2 at the mercy of the swell, measured between the transverse axis passing through the point 14 anchoring (substantially fixed, as we have seen) and a transverse axis central to the beam 10, between a low position of the beam 14 where it is in the hollow 35 of the swell, and a high position where it is at the top of a ridge. If the unit 2 is dimensioned so that the distance between the floats 21, 22 and the beam 10 is substantially equal to the half wave mean wavelength (ie about 70 to 100 m), the floats 21, 22 and the stern 6 then being respectively at the hollow and at the top of the swell or vice versa, this results in a greater angular amplitude of the floats 21, 22 with respect to the platform 2, and consequently a greater energy efficiency of the machine 3 wave (and therefore the central 1). In order to further increase the energy efficiency of the wave machine 3, it is equipped, for each float 21, 22, with at least one deflector 34 mounted on the platform 2, this deflector 34 having an upstream face 35 which extends opposite and at a distance from the stern 26 of the float 21, 22 to define therewith a narrowing 36 for channeling and vertical deviation of the swell. (In FIGS. 5, 7 and 9, the free surface of the sea is shown in phantom.) As can be seen in FIGS. 5 and 7, the deflector 34 is in the form of a panel which extends transversely over the entire width of the float 21, 22 behind which (in the downstream direction) it is mounted. In the illustrated example, where the wave machine 3 comprises four floats 21, 22, the machine 3 comprises four baffles, respectively associated with each of the floats 21, 22, and each mounted in a compartment 31. According to a preferred embodiment, each deflector 34 is movably mounted relative to the platform 2, between: an active position in which the deflector 34 extends in the vicinity of the float 21, 22 corresponding to define the neck 36 with it to deflect the swell upwards , and an inactive position in which the deflector 34 is spaced from the float 21, 22 to freely pass the swell, especially in case of storm. In practice, the deflector 34 is for example pivotally mounted relative to the platform 2, and more precisely with respect to the longitudinal walls 19 and / or 32. In the example shown, each deflector 34 has a lower edge through which it is mounted articulated about a transverse axis 37 which extends through the compartment 31 between the longitudinal walls 19 and / or 32 whose axis 37 is integral, and a free upper edge which can protrude from the upper longitudinal edge 8 of the boxes 4 .

In its active position (solid line in Figures 5 and 7), the deflector 34 extends substantially vertically or strongly inclined relative to the horizontal. Conversely, in the inactive position (in dashed lines in FIGS. 5 and 7), the deflector 34 extends substantially horizontally, in the vicinity of the extrados 12 of the fin 11. The control of the pivoting of the deflector 34 from its active position at its inactive position (and conversely) can be hydraulic, mechanical or electrical.

As can be seen in FIGS. 5 and 7, the upstream face of the deflector can substantially match that of the stern 26 of the float 21, 22. Thus, in the case illustrated, where the stern 26 is arched, the face 35 upstream of the float can also be arched. The flow lines of the seawater which rushes under the float 21, 22 are illustrated by means of arrows in FIGS. 5 and 7. It can be seen that the water passes under the float 21, 22 to come engulfing in the neck 36, which acts in the manner of a venturi and induces an overpressure under the float 21, 22 thus increasing the angular amplitude thereof, to the benefit of the energy efficiency of the machine 3 wave. According to an embodiment illustrated in FIGS. 5 and 7, the platform 2 comprises a stop 38 against which the deflector 34 is applied in the active position. In this way, the deflector 34 is maintained in the active position and the neck 36 is retained regardless of the angular position of the float 21, 22. In order to increase the lift of the float 21, 22, it can be provided, on its stern 26, a bead 39 which forms a restriction in the neck 36 and induces a deflection of the flow which locally increases the pressure and further increases the angular amplitude of the float 21, 22, to the benefit of the energy efficiency of the 3 wave machine. A possible embodiment of the converter 27 is now described with reference to FIGS. 8 to 10. The converter 27 (with its motor shaft 28) is preferably housed in the gantry 20, which is advantageously dimensioned sufficiently generously to form a technical room likely to allow human intervention on the converter 27 in an acceptable comfort.

In the example illustrated in FIGS. 8 to 10, the converter 27 comprises a pair of ratchet wheels 40 mounted on the motor shaft 28. According to an embodiment illustrated in the figures, each ratchet wheel 40 comprises a ring 41 provided with a unidirectional internal gearing 42 and an external bidirectional gear (not shown). The converter 27 further comprises a wheel 43 carried integral with the motor shaft 28 and on which is mounted in rotation a pawl 44 in unidirectional engagement with the internal toothing 42. The pawl 44 is biased towards the toothing 42 by a spring 45.

The converter 27 furthermore comprises a geared toothed wheel 46 integral with the arm 23 and in direct gear engagement with the external toothing of the ring gear 41 of a first ratchet wheel 40, as illustrated in FIGS. 8 and 9. converter 27 further comprises a secondary gearwheel 47 integral in rotation with the driving wheel 46 and in gear engagement with the external toothing of the ring gear 41 of the second wheel 40 to ratchet through a gear 48 inverter. When the driving wheel 46 rotates with the arm 23 in a first direction of rotation (clockwise in the figures, see arrow F1, FIGS. 8 and 9), the latter drives the ring gear 41 of the first ratchet wheel 40 into the reverse (counterclockwise, arrow F2, Figure 9). The pawl 44, in engagement with the internal toothing 42, then drives the driven wheel 43 (and therefore the motor shaft 28) in the same direction as the ring 41 (anticlockwise, arrow F3, FIG. 9). At the same time, the secondary gearwheel 47 drives, via the gear 48 inverter, the ring 41 of the second wheel 40 ratchet in the clockwise direction, the ring 41 then rotating freely around the motor shaft 28. Conversely, when the driving gear wheel 46 rotates counterclockwise, it drives the ring 41 of the first wheel 40 ratchet clockwise, the ring 41 then rotating freely around the motor shaft 28. At the same time, the secondary toothed wheel 47 drives (counterclockwise in the figures, see arrow F4, FIG. 10), via the inverter pinion 48 (clockwise, arrow F5), the ring 41 of the second wheel 40 ratchet counterclockwise (arrow F6). The pawl 44, engaged with the internal toothing 42, then drives the driven wheel 43 (and thus the motor shaft 28) in the same direction (counterclockwise) as the ring 41.

Thus, regardless of the direction of rotation of the floats 21, 22, one or the other of the wheels 46, 47 toothed drives the motor shaft 28 via one or other of the wheels 40 ratchet. In other words, the conversion is permanent, whether the movement of the float 21, 22 is upward or downward. The conversion of this mechanical energy into electrical energy is advantageously carried out by means of a generator (such as a transformer) coupled to the live motor shaft 28 or, preferably, via a multiplier. Note that the converter 27 may include at least one flywheel mounted for example directly on the motor shaft 28, so as to limit jolts and thus regulate the speed of rotation of the motor shaft 28 (and therefore the operating regime of the plant 1). This results in a smoothing of the production of electric current. FIG. 11 shows a variant of the central unit 1, in which the (or each) deflector 34, instead of being arched, is straight, the upstream face 35 being substantially flat. This variant allows, in the inactive position of the deflector 34 (in dashed lines in FIG. 11), to offer a minimum resistance to the flow of water. In addition, as is also illustrated in FIG. 11, the pressure of the swell on the (or each) deflector 34 can be used to increase the energy production. For this purpose, the wave machine 3 is provided, for the (or each) deflector, with a cable 49 which, at a downstream end, is fixed to the deflector 34 and which, by an opposite upstream end, is wound on a pulley integral with the axis 24 of rotation of the floats 21, 22. As long as it allows an angular deflection of the deflector 34, the oscillations thereof allow, at least in the direction of rotation tending to move away from its active position , to rotate the pulley which, in the manner of the driving wheel 46, drives the driven wheel 43 (and thus the drive shaft) by the same mechanism as that described above with reference to FIGS. 8 and 9. and the flapping energy of the deflector 34, to the benefit of the energy efficiency of the machine 3 wave (and therefore the central 1). It may optionally adjust the tension of the cable 49 to change the width of the neck 36 and thus modulate the pressure of the water under the float 21, 22 so as to adjust its lift and the power generated.

In addition, the upstream face 35 of (each) deflector 34 may have roughnesses favoring, in and under the neck 36, the appearance of vortex movements favorable to the lift of the float 21, 22 and thus contributing to the energy efficiency. of the wave machine 3. In addition, it is conceivable to provide that instead of being offset the floats 21, 22 are identical. In this case, one can provide a single deflector that extends over the cumulative width of the floats.

Claims (12)

REVENDICATIONS1. Power plant (1), comprising: a semi-submersible platform (2) provided with at least one longitudinal box (4) extending from a bow (5) to a stern (6) of the platform (2) ); a machine (3) wave mounted on the platform (2), this machine (3) comprising: o a gantry (20) mounted transversely on the box (4), o at least one float (21, 22) arranged to allow the transforming the energy of the swell into mechanical energy, the float (21, 22) being fixed to an arm (22) rotatably mounted on an axis (24) secured to the gantry (20), the float (21, 22) having a bow (25) facing the bow (5) of the platform (2) and a stern (26) facing the stern (6) of the platform (2), the central (1) being characterized in that the machine (3) comprises at least one wind deflector (34) mounted on the platform (2), this deflector (34) having an upstream face (35) extending opposite and at a distance from the stern (6) of the float (21, 22) for defining therewith a neck (36) for channeling and vertical deviation of the swell. 2. Central (1) according to claim 1, characterized in that the deflector (34) is mounted to move relative to the platform (2) between an active position in which it extends in the vicinity of the float (21, 22 ) to define the neck (36) with it, and an inactive position in which it is spaced from the float (21, 22). 3. Central (1) according to claim 2, characterized in that the deflector (34) is pivotally mounted relative to the platform (2). 4. Central (1) according to claim 2 or claim 3, characterized in that the platform (2) comprises at least one wall (19, 32) secured to a vertical box (4), on which is fixed the deflector (34). 5. Central (1) according to one of claims 2 to 4, characterized in that the platform (2) comprises a stop (38) against which comes to apply the deflector (34) in the active position. 6. Power plant (1) according to one of the preceding claims, characterized in that the wave machine (3) comprises several floats (21, 22) arranged in parallel, and a deflector (34) for each float (21, 22). . 7. Central (1) according to claim 6, characterized in that the floats (21, 22) are rotatably mounted on a common axis (21, 22). 8. Central (1) according to claim 6 or claim 7, characterized in that the machine (3) comprises wave at least one float (21) upstream and a float (22) downstream offset float (21) upstream to the stern (6) of the platform (2). 9. Central (1) according to one of the preceding claims, characterized in that the platform (2) comprises for each float (21, 22) a compartment (31) transversely delimited by longitudinal walls (19, 32). 10. Plant (1) according to one of the preceding claims, characterized in that the platform (2) comprises two longitudinal boxes (4) defining between them a channel (7), and in that the machine (3) comprises wave at least one float (21, 22) extending between the caissons (4). 11. Central (1) according to one of the preceding claims, characterized in that the platform (2) comprises a fin (11) stabilizer, this fin (11) carrying a point (14) for anchoring a mooring ( 15) for fixing the platform (2) to the seabed (16), this anchoring point (14) being offset from the axis (24) of rotation of the float (21, 22) in the direction of the stern (6). ). 12. Plant (1) according to one of the preceding claims, characterized in that the machine (3) comprises a wave generator for transforming the mechanical energy of the float (s) (21, 22) into electrical energy.