EP0172807A1

EP0172807A1 - Wind energy conversion apparatus

Info

Publication number: EP0172807A1
Application number: EP84900999A
Authority: EP
Inventors: Victor Kyprianos Fieros
Original assignee: Individual
Current assignee: Individual
Priority date: 1984-03-05
Filing date: 1984-03-05
Publication date: 1986-03-05
Also published as: WO1985003981A1; AU2651584A

Abstract

L'appareil comprend un dispositif à entonnoir (1, 2) servant à canaliser une portion verticale de la masse d'air vers un rotor (20) possédant un axe vertical de rotation. Les deux parties du dispositif à entonnoir sont montées sur des plateaux tournants, de sorte que le dispositif puisse toujours être orienté contre le vent. Le rotor est cylindrique avec des organes arqués mobiles (24), se déplaçant entre des positions en retrait et d'extension par rapport au rotor. Lorsque les organes en retrait (24) font partie de la surface cylindrique et carénée du rotor et lorsque la masse d'air en écoulement agit sur ces organes, ils se déplacent vers leurs positions d'extension où la force du vent les sollicitant est convertie en un moment de rotation autour de l'axe vertical du rotor.The apparatus includes a funnel device (1, 2) for channeling a vertical portion of the air mass to a rotor (20) having a vertical axis of rotation. The two parts of the funnel device are mounted on turntables, so that the device can always be oriented against the wind. The rotor is cylindrical with movable arcuate members (24), moving between recessed and extended positions relative to the rotor. When the recessed members (24) are part of the cylindrical and shrouded surface of the rotor and when the mass of flowing air acts on these members, they move to their extended positions where the force of the wind urging them is converted in a moment of rotation around the vertical axis of the rotor.

Description

WI D ENERGY COWERSi J APPARATUS ___X_HNICAL FIELD

This invention relates to an apparatus for deriving energy in usable form from the wind. BACKGROUND ART Various kinds of wind energy conversion apparatus are, of course, well known and it is generally accepted that the most efficient forms of such apparatus are the prcpeller type. Efcwever, the propeller type of apparatus has various practical disadvantages so that the provision of a propeller-type wind energy conversion apparatus which is capable of providing large quantities of power is very expensive.

Many of the practical difficulties presented by the propeller type of apparatus can be avoided by adopting a machine which has a rotor with a vertical axis of rotation, and various, vertical axis machines have been suggested such as the Savonius and Darrieus. Moreover there are wind driven power producing apparatus with a vertical axis of rotation, which have been subject to several prior patents, e.g. British Patent No. 304,514 dated January 24, 1929, and U.S. Patent No. 4,004,861 dated January 25, 1977. Both these patents have pivotably mounted members which in their retracted position present very little resistance to the wind, and this aspect is also true of this invention.

It is an object of this invention to provide an improved wind energy conversion apparatus having a rotor with a vertical axis of rotation.

DISCLOSURE OF THE INVENTION According to this invention there is provided a wind energy conversion apparatus comprising a rotor mounted for rotation about a vertical axis, said rotor having a plurality of arcuately shaped wind catching members which are each movably mounted on the rotor for movement between an extended and retracted position relative to the rotor, whereby in the retracted position of said members the n_____bers form a substantially cylindrical and streamlined surface of the rotor, characterised in that the rotor is wind impervious and there is provided at least one deflector mounted for rotation about an axis of rotation which is concentric to the axis of rotation of the rotor, said deflector being arranged to rotate so that it is always positioned for energy production upwind and to one side of said rotor, whereby said deflector acts upon a horizontally proceeding air current, deflects said air

O PI current in such a way as to converge to one side of said rotor facing the wind so as to produce a kinetic force and a pressure force on one side of the rotor in order to force the arcuately shaped wind catching members to move and stay in the retracted or nearly retracted positions thereof, the excess air current being diverted over the surface of the said rotor, past the point of the said rotor nearest the said horizontally proceeding air current, thus allowing each said arcuately shaped wind catching member in turn to start moving at said point of circular rotation thereof from the retracted position to the extended position thereof, and at said point, the full force of the wind flew acts on said meπiber, which ire ber follows the circular path of the rotor until another ire-riber reaches its extended position, the first wind catching meπiber, being out of the wind flow, starts returning to the retracted position thereof.

This invention has two main parts, the first is the funnelling of a relatively large vertical area of wind, (relative to the size of the rotor) to a particular segment of the rotor, and the other part, consists of a wind irrpervious rotor having a vertical axis of rotation, with movably mounted arcuately shaped members which move between retracted and extended positions relative to the rotor. The two parts are interdependent, and both are mounted on turntables, so that the funnelling apparatus may always face the wind at a predetermined position. The funnelling apparatus, and the rotor form an interdependent unit.

In a basic form the funnelling apparatus comprises at least one deflector positioned upwind and to one side of the rotor facing the wind so as to deflect a large vertical area of wind towards the rotor. Part of this wind flow, or all of it, will flow over the surface of the rotor facing the wind, and as the wind flow strikes the surface of the rotor nearest the wind direction each movable meπiber canes under the influence of this flow to move frατi it's retracted to it's extended position, whereupon the meπiber will cαtve to a rather sudden stop. The pressure of the wind, plus the hammer effect, or irrpact pressure caused by the member ∞ming to a sudden stop, plus any reaction or lift forces that this sudden stop will produce, will be converted to useful energy about the vertical axis of the rotor. The rotor will then continue to turn with the one member at it's extended position under the influence of the full pressure of all the wind flew, until another meπiber reaches it's extended

OMPI position, in which case, as the pressure will thus be suddenly cut off, the first member will resiliently start returning to it s retracted position through a combination of wind suction, mechanical means, and wind pressure, and it will stay at this retracted position under the influence of mechanical means such as latches or rollers or counter weights, or wind pressure, or a combination thereof.

In the preferred embodiment of the invention, the periphery of the rotor may be regarded as being effectively impermeable to the wind even when the wind catching members are in their extended positions, so that in operation, the majority at least of the air flew passes round the periphery of the rotor, rather than, for example, through it. BRIEF DESCRIPTIC__ OF THE DRAWINGS

The invention will new be described by way of example with reference to the acconpanying drawings in which:- Figure 1 shows, in plan view, the principle of operation of a wind energy conversion apparatus rotatable about a vertical axis,

Figures 2 and 2A illustrate the basic concept, in plan view, of the wind energy conversion apparatus,

Figure 2B is a view similar to Figure 2A but shows another embodiment in which all the wind flow deflects over the rotor surface nearest the wind direction, and there is no wind flew on the left hand side of the rotor,

Figures 3, 4, 5 and 5A diagrammatically shew various embodiments of support apparatus for the invention, Figure 6 shows an underside view of the apparatus.

Figure 7 shows a construction of an alternative funnelling apparatus for this invention,

Figures 8 and 9 illustrate various constructions of the rotors used in this invention, Figure 10 shows a perspective vertical view of an apparatus in accordance with this invention, and shows the relationship of the rotor to the funnel apparatus and to the wind direction,

Figures 11A and 11B respectively shew in cross-section a side and a plan view of a venturi type funnelling apparatus, Figures 12A and 12B respectively show a side and a plan view of an apparatus for orienting the funnelling apparatus in respect to wind direction,

OMPI Figures 13A and 13B respectively show in cross-section a side and a plan view of another embodiment for orienting the funnelling apparatus in respect to wind direction.

In the Figures like reference numerals denote like parts. BEST MODE OF CARRYING OUT THE INVENTION

Referring to Figure 1, the arrow headed line "W" represents the direction of the wind striking the wind energy conversion apparatus, shown schematically as a rotor 20 having an axis of rotation 22. According with convention, the direction directly contrary to the wind direction is reckoned as 0° while directions progressively more clock¬ wise are reckoned (in terms of angles about the rotor axis 22) as progressively greater angles up to 360°.

Referring to Figure 2, the rotor 20 is shown in cx_mbination with a single deflector 1. The wind direction " " is again shown and the flow of air on both sides of the drum is indicated by arrow headed lines Wl, W2. Figure 2 illustrates the basic concepts of this invention, that is, the cylindrical rotor 20 having, in the embodiment shown, six arcuately shaped members 24, each movable between an extended and a retracted position, and the concentration of a large vertical area of wind onto extended movable members 24. From one side of the rotor, the flow of air Wl produces energy, and frcm the other side the flow of air W2 helps keep the manbers 24 substantially in their retracted position. In Figure 2 the inner part of the rotor has a polygonal cross-section, but it could be cylindrical, or any convenient shape. The drum 20, in operation, rotates in the direction indicated by arrcw headed line 5 and the members 24 are placed in their extended positions over at least a substantial part of the portion of the circumferential path of the rotor in the sector extending from 0° through 90° to 180° (which is herein referred to as the "energy sector" denoted by arrow headed line "E" in Figure 1), and are placed in their retracted positions, or nearly their retracted positions, over a substantial part at least,of the portion of said path in the section extending frcm 180° through 270° to 0° again, (this sector being herein referred to as the "return section" denoted by arrow headed line R). It will be appreciated that the force exerted by the wind on the members 24, tangentially to the drum, is substantially greater when the members 24 are in their extended positions, since when the members 24 are in their extended positions this force is produced by a combination of

f OMPI aerodynamic pressure and lift forces, reaction^" forces and a "haπroer effect" caused by the member 24 being extended and suddenly meeting a step, while the force exerted in the retracted positions of the members 24 is substantially limited to skin friction. It must be appreciated 5 that for an anticlockwise rotation of the rotor, "E" will be on the left of 0° while "R" will be on the right of 0°.

A more advanced version of Figure 2 is shewn in Figures 2A, but the basic concepts remain the same. Figure 2A shews an extra deflector 2, to the right of the rotor (next to the energy sector). The purpose of the deflector 2 is to increase the area of wind, and thus increase the flew of air, to the extended members 24. The ^' deflector 2 also has the added advantage of balancing the force of the wind on deflector 1, thus substantially reducing the turning nxxnent on the funnelling part produced by the deflectors. Boths Figures 2 and 2A shew six members 24, but the number of members 24 that a rotor has may be increased or decreased. The size of the members 24, (radial outward length measured from the rotor) may vary from overlapping the preceeding member, to a length whereby a gap is left between the top of one member and the pivot of the adjacent member. Figure 2B shows another location for deflector 1 in which all the wind flow deflected by deflector 1 flows over the surface of the rotor nearest the wind direction. This arrangement presupposes that wind action is not required to retract and hold the member 24 to it's retracted position, and an efficient mechanical means to perform retraction must be incorporated into the apparatus. Such a mechanical means may be provided by springs (not shown) for retracting the members 24 and latches 71 to hold members 24 in their retracted position. The latches 71 are required since inertia of the members 24 when moved out of the wind flew by the springs will tend to swing the members 24 bacik to their extended positions. A simple latch may be formed by a rod and lever type of mechanism to allow the member to swing to it's extended position when the member 24 moves into the energy sector.

Figure 3 illustrates a turntable construction which is similar in nature to the rear axle housing of trucks but with turntables 42 and 43 instead of trucfk wheels, and without a truck's differential. The turn¬ tables 42 and 43 are located outwardly of bearings 40 and 41 respectively which act as thrust bearings and turn only in a horizontal plane. A

OMPI IPO shaft 22 of the rotor 20 is joined to a turntable 43, and passes through a housing 44, through bearing 31 which is bolted onto turntable 42 and is supported at the top part 47 of the funnelling apparatus by a bearing 30. The bottom part 48 of the funnelling apparatus is connected to turntable 42. The housing 44 is supported in a tower structure 36. The two bearings, 30 and 31 may be self aligning bearings. Such a construction is for small units with a small rotor height where there is very little differential movement between the bottom and top members of the funnelling part apparatus. The weight of the rotor is taken by the bottom turntable 43, which turns with the rotor and a flexible joint 35 is provided below the turntable 43. The shaft 22 belcw joint 35 is connected to a driven device which may be, for example, a generator, alternator pump etc.

The embodiment of the apparatus shewn in Figure 4 is very similar to that of Figure 3, but in Figure 4 the shaft of the rotor has a flexible joint 33 just above bearing 31, and this joint 33 helps to eliminate any fatigue failure of shaft 22 at bearing 31. Such a construction is suitable for very much taller rotors than those of Figure 3, the weight of the rotor still being taken by the bottom turntable 43. The em__odiment shewn in Figure 5 is for very big units, and in this -srntodiment, bearing 32 is a self aligning thrust bearing. The weight of the rotor is taken by turntable 42. A flexible joint 34 is provided below bearing 32.

The eπ_bod__ment shown in Figure 5A is similar to that of Figure 5, except there is also provided a rail support 46, which is joined to the tower structure 36, and with rollers 45, which are part of the funnelling apparatus, the whole apparatus thereby beccπies very rigid in a vertical plane. In the Figures 3-5A it will be noted that the rotor 22 is held rigidly in the upright position between the top and bottom members of the funnelling apparatus by bearing 30 and 31 (or 32).

Referring to Figure 6, the funnelling apparatus and it's relationship to the rotor and also to the wind direction "W" is shown. The wind flew is from both sides of the rotor 20 facing the wind, and the gap that deflector 1 makes with the rotor surface 20 will depend on factors such as the inertia of members 24, on whether any counter weights are used, and on how much help the springs or any other mechanical means can exert on matibers 24 to keep them from swinging outwards due to centrifugal force caused by the circular motion of the rotor 20, the

OMP objective always being that member 24 should at^" no time, and under no circumstances cc_re into contact with deflector 1. However, the nearer that the deflector can be to the rotor, the better. In Figure 6 the funnelling apparatus structure is supported on the circular rail 46 by radial arms 200, 201 and 202 in the vertical plane, and by turntable 42 in the horizontal plane. More radial arms may be used if required.

Figure 7 shews a special case, where side 1 and side 2 of the funnelling apparatus can swing away from the wind (as shewn in broken lines) on vertical pivots 3, 4 respectively. This design may be used with advantage where wind velocities may be very great, and minimum resistance of the structure to the wind is of importance. As deflectors 1 and 2 swing away, members 24 may not open if they incorporate a latch and lever arrangement that locks the members 24 in their retracted positions. Figures 6 and 7 both have a partial top (not shown) and a bottom cover between deflectors 1 and 2, which covers may be parallel to each other, or they may be inclined to one another to also converge wind onto the rotor. The covers may be more or less complete between deflectors 1 and 2, and may cover all the horizontal area to beyond the extended position of member 24. To summarise the amount of cover for maximum efficiency has many variables; for small average wind velocities, more cover will improve the efficiency, while for greater wind velocities, less cover will allow the wind to get away quickly when member 24 opens to it's extended position, thus have a miriimum of interference with the volume of wind going through the funnel. It is therefore of paramount iirportance that the amount of cover should be such that affects the least the flow of wind through the apparatus under the average wind conditions of the locality. Deflectors 1 and 2 may be flat plates, or corrugated flat plates, or have any number of different curvature configurations. Figure 8 illustrates a plan view of the rotor with different arrangements for absorbing the energy of the movement of members 24 to their retracted and extended positions, but it is to be realised these are only a few of many different possible alternatives that will be self- evident to the nan skilled in the art, but they will help illustrate seme of the actions. Compression springs 61 and 62 are engaged around a rod 60 so that spring 62 is conpressed when member 24 is in the extended position, and spring 61 is ccπpressed when member 24 is in the retracted position. Rod 60 also acts as a stop at the extended position. Any convenient number of rods 60, and springs 61 and 62 may be used for each member 24. Another arrangement is to use a chain 70 as a stop, with springs 64 and 63, and as will be seen frcm Figure 9, a spring 65 may be used between two chains 70. A spring 90 may be required when member 24 reaches to it's retracted position. A latch or ratchet arrangement 71 may be used to lock members 24 in their retracted position when required, as in the case of stopping the rotor when the winds become very strong, and the latches 71 may be automatically activated. Springs 62, 63, 64 and 65 may be used with advantage to keep member 24 in a semi-retracted position until the wind pressure in the return sector acts on member 24 to bring it to it's retracted position. Latch 71 may also be used to hold member 24 into a position towards it's retracted position, because in practice, as soon as member 24 moves out of the wind flow, it will resiliently retract, but then it's inertia will act on it with a tendency to swing it to it's extended position again, and there will be a loss of energy to bring it back towards it's retracted position. Thus by utilising latch 71, (which may also be used to stop the rotor by keeping matibers 24 in their retracted positions), it will be very much easier to further force members 24 to their retracted positions by wind pressure on the return sector. If the apparatus has a deflector 1, as illustrated in Figure 2B, then an arrangement such as latches 71 in ccnjunction with the correct springing to resiliently retract the members 24 as scon as they move out of the wind flow, to as near as possible their retracted position is desirable. The latch 71 is arranged to keep hold the meπiber 24 until the meπiber 24 is ready to start moving towards it's extended position upon reaching the energy sector, whereupon, by mechanical or other means, latch 71 is made to release member 24.

Figure 10 shews a perspective view of the apparatus with "W" indicating the wind direction. It is to be noted that the deflectors 1, 2 are wind irrpervious whilst the support structure extending frcm 180° to 270° is simply a framework.

Figures 11A and 11B show a sectioned side and plan view of a venturi type funnelling apparatus. Such a design may be more efficient in funnelling the air flew through the apparatus, and also has the added advantage of being self aligning, especially with the addition of adjustable rudder vanes. The apparatus has a fin 210, and an adjustable rudder 211. A venturi effect may be produced which extends to the part of the rotor remote from the wind direction.

Figures 12A and 12B illustrate an embodiment of an apparatus which is just one possible way of orienting the funnelling apparatus to face the wind "W" in a predetermined position. A chain drive 125 is connected to turntable 42, or to a greater circular path fixed to the bottom radials if a greater circular path is required. For economic reasons sprockets (not shewn) need not extend all the way round the circular path. Tensioners and anti-sag supports (not shown) may be incorporated if required. The chain 125 is connected to a starter arrangement consisting a sprocket 124 connected to a drive shaft located in bearings at each end of a housing 122, the shaft being driven by a wheel 127, in turn driven by a pinion 121 of a starter motor 120. Starter 120 is activated by a wind direction vane (not shown) located at the top of the funnelling apparatus, and as the wind direction changes so the vane activates a switch 123 which releases pin 126, and starts the starter 120. The starter turns clockwise or _tn_iclockwise depending on the wind direction, and when the wind direction and the vane are in their predetermined fixed relationship to each other, the switch is disconnected, and the starter stops, and pin 126 locks the drive in position.

A fin and rudder type of arrangement for orienting the funnelling apparatus to face the wind is shewn in Figure 13. The arrangement has a fixed fin 330 and 331 a rudder, but it is to be understood fin 330 may be an adjustable rudder. Figure 13B shews in broken lines an alternative embodiirient having a twin fin and rudder arrangement 340, 341, the advantage of such an arrangement being that it has a much bigger area of fin and rudder in contact with the air stream. Members 340 and 341 may be hinged in the vertical plane, or they may be fixed, having a rudder arrangement such as 331.

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Claims

CIAIMS:

1. A wind energy conversion apparatus comprising a rotor (20) mounted for rotation about a vertical axis (22), said rotor having a plurality of arcuately shaped wind catching maτibers (24) which are each movably mounted on the rotor for movement between an extended and retracted position relative to the rotor, whereby in the retracted position of said members the members form a substantially cylindrical and streamlined surface of the rotor, characterised in that the rotor (20) is wind iπpervious and there is provided at least one deflector (1) mounted for rotation about an axis of rotation which is concentric to the axis of rotation of the rotor, said deflector being arranged to rotate so that it is always positioned for energy production upwind and to one side of said rotor, whereby said deflector acts upon a horizontally proceeding air current, deflects said air current in such a way as to converge to one side of said rotor facing the wind so as to produce a kinetic force and a pressure force on one side of the rotor in order to force the arcuately shaped wind catching members (24) to move and stay in the retracted or nearly retracted positions thereof, the excess air current being diverted over the surface of the said rotor, past the point of the said rotor nearest the said horizontally proceeding air current, thus allowing each said arcuately shaped wind catching member in turn to start moving at said point of circular rotation thereof from the retracted position to the extended position thereof, and at said point, the full force of the wind flew acts on said member, which member follows the circular path of the rotor until another member reaches its extended position, whereupon the first wind catching meπiber, being out of the wind flow, starts returning to the retracted position thereof.

2. A wind energy conversion apparatus according to claim 1 characterised in that two deflectors (1, 2) are provided, one deflector (2) being positioned to converge wind to said one side of said rotor and the other deflector (1) being positioned to produce a wind flew converging towards said one side of the rotor facing the wind.

3. A wind energy conversion apparatus according to claim 1 or 2 characterised in that there is provided a top and a bottom cover* (49) between the deflectors (1, 2) so as to thereby form a funnel-like arrangement for restricting air spillage between the deflectors (1, 2). 4. A wind energy conversion apparatus according to claim 3 characterised in that the top and bottom covers are inclined toward one another so as to converge the wind towards the rotor.

5. A wind energy conversion apparatus according to claims 3 or 4

5 characterised in that the top and bottom covers are partially removed in the portion adjacent the rotor.

6. A wind energy conversion apparatus according to claims 1 to 4 characterised in that the deflectors and covers are so positioned in relation to the rotor that a venturi effect is produced which extends to

10 the part of the rotor remote from the direction of wind.

7. A wind energy conversion apparatus according to claim 6 characterised in that a fin (210) and an adjustable rudder (211) is provided on the deflector to render the deflector self-aligning in accordance with the direction of wind.

158. A wind energy conversion apparatus according to any of claims 1 to 6 characterised in that the deflectors are oriented in relation to the wind by a motor driven apparatus (120-127) and wherein means (126) are provided for locking the deflectors in position. 9. A wind energy conversion apparatus according to any preceding

20 claim characterised-in that resilient means (61, 62) are provided to assist the members (24) into the extended position thereof and a step member (70) is provided to limit the extension of said members (24), there also being provided a latch means (71) for predeterminedly securing the maribers (24) in the retracted position thereof.

2510. A wind energy conversion apparatus according to any preceding claim characterised in that the deflectors (1, 2) are pivoted about a respective vertical axis (3, 4).

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