Oscillating device for generating electricity and method for adjusting oscillating devices

Described is an oscillating device for generating electricity from a fluid flow, comprising at least one oscillating part, at least one support, fixed to a reference surface and connected to the oscillating part at an oscillation axis, at least one counter-balancing system connected to, and/or acting on the oscillating part, at least one adjustable profile configured to be at least partially immersed in the fluid flow and movably connected to the oscillating part. The oscillating device comprises an adjustment system configured to change the position of the adjustable profile with respect to the fluid flow between at least one position of greatest resistance and at least one position of least resistance. The invention also relates to an adjustment method for oscillating devices designed to generate electricity, according to which adjustments to the position of the adjustable profile are made as a function of certain parameters, such as the speed and/or the change in direction of the oscillation of the oscillating part, detected by a series of sensors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase under 35 U.S.C. § 371 of International Application PCT/IT2021/050181, filed Jun. 10, 2021, which claims priority to IT Application No. 102020000013912, filed Jun. 10, 2020, the entire contents of each of which are incorporated by reference herein and made a part of this specification.

SUMMARY

This invention relates to an oscillating device for generating electricity and a method of adjusting oscillating devices.

The prior art systems use profiles attached to the oscillating part, which are moved to vary their position with respect to the fluid to power the movement of the oscillating part.

The prior art oscillating devices, as they subject to highly variable weather conditions, present some drawbacks in the presence of strong gusts of wind or irregular wind; the drawbacks are related to damaging stresses and risks of breakages to self-supporting or sail profiles with frames with potential breakage and detachment of the frame, which, in addition to damaging the device, may represent a danger to the surrounding environment (oscillating devices of this type are described, for example, in patent documents US2009/224553A1 and BE1018730A3). Moreover, in situations of excessive wind, in the prior art devices a critical intensity of the fluid flow must necessarily be measured (for example, by means of sensors, such as anemometers) and then the oscillating part or individual profiles must be lowered by means of operations (such as folding side fins or shortening the telescopic shaft), which due to the size of the devices cannot be immediate and in any case is substantially longer than tens of seconds, thus exposing the devices to the problems described above.

It should be further considered that incidental failures in the power supply of actuators for the adjustment of the profiles or other mechanical failures would cause the profiles to remain in a position of increased resistance with consequent damage from such exposure. Moreover, in the case of devices whose profiles are configured like Savonius turbines rotating freely (as in patent document BE1018730A3), these profiles would rotate at high speed in the event of gusts, exposing the device to breakages.

Another problem of the prior art technique is related to the profile adjustment systems, which implement both the steps with a stress command (as in patent document US2009/224553A1), with the difficulty of being able to align the profiles to the fluid flow and minimise the damping; even in the systems where the profiles rotate freely to the fluid (due to the difference in resistance between the concave and convex part of the two profiles) even in the return step (as in patent document BE1018730A3) there is a damping, since the profile, rotating during the return step, does not maintain a constant angle of attack with respect to the fluid during the return oscillation and, moreover, in the presence of certain intensities of fluid flow, there may be a loss of synchrony between the rotation of the profiles and the oscillation of the device.

Other disadvantages of the prior art relate to the type of profiles used, which are rigid or framed and which rotate with respect to a shaft and/or pin connected to the oscillating part. Such a coupling causes some problems, also taking into account the aerodynamic and adjustment advantage of making several profiles with a reduced chord for the same overall surface. There can in fact be constructional difficulties in sizing adequate surfaces of the profiles to withstand the stresses of very high winds, increased production and maintenance costs and increased overall structural weight.

A further problem with prior art solutions concerns the method of adjusting the oscillating devices, and in particular when and how the control of the profile adjustment is actuated.

In fact, the adjustment in the prior art devices is obtained by means of weights or actuators that intervene on predetermined values of the oscillation angle (see for example patent documents US2009/0224549 and WO2009/110997) or that modify the inclination of the profiles when the inclination of the oscillating part changes (as in patent document AT508273A1 for the thrust step) or that can also be influenced by the intensity of the flow (as in patent document AT508273A1 for the recall step). One problem with patent document AT508273A1, for example, is that a certain fluid intensity may not be sufficient to keep the profile open for the recall step, whereas above a certain fluid intensity the profiles may remain open.

In the prior art there are no adjustments on the adjustable profiles, which intervene substantially instantaneously when the oscillation is about to be completed in both the thrust and recall steps and also independently of the fluid flow and irrespective of a predetermined value of the oscillation angle.

Another drawback is the resistance that the oscillating part presents when changing direction where the acceleration is maximum.

A further problem is the frequency of the adjustments, which in prior art devices is bound to the frequency of oscillation.

Lastly, in prior art oscillating devices, there is the structural and overall size problem of using large flywheels in order to accumulate kinetic energy to be constantly transferred to a current generator.

In summary, the main problems that the invention aims to overcome are related to:general efficiency of the device,adaptation and safety of the device to the various and changing working conditions which are possible,frequency and method of implementation of the adjustments to be made to the adjustable profiles,overall structural weight of the device,rated power of the device as a function of the profile surfaces and the length of the oscillating part,anchoring the device support in its positioning location,transmission of the oscillation to storage flywheels and/or current generators,reliability, construction and maintenance cost-effectiveness.

The main aim of the invention is to overcome the above-mentioned drawbacks of the prior art.

In particular, the aim of the invention is to improve the energy efficiency of the prior art oscillating devices.

Another aim is to be able to increase the nominal power by increasing the surface area of the profiles and/or increasing the length of the oscillating so part with respect to the prior art (increase in useful leverage with the same weight, construction costs and safety).

Another aim is to improve the reliability and safety of prior art oscillating devices under the various flow conditions.

These and other aims are achieved by an oscillating device for generating electricity, which advantageously uses an innovative connection system between the adjustable profiles and the oscillating part according to the appended claim1, and by an innovative method of adjusting oscillating devices according to the appended claim14.

Further technical features are indicated in the dependent claims.

According to the invention, advantageously the adjustable profiles are connected to the oscillating part in such a way as to allow the system to implement an active adjustment (that is, by means of a thrust, traction or torque action) on the adjustable profiles to bring them to a position of greatest resistance with respect to the fluid (a position which can be maintained for the entire useful thrust step) and to passively release them so that they adopt a position of least resistance with respect to the fluid (a position which can be maintained for the entire recall step).

The invention also describes an adjustment method which can be advantageously applied independently of the fluid flow, the weight of the profiles and/or a predetermined angle.

DETAILED DESCRIPTION

The accompanying drawings show an oscillating device comprising a support105designed to support an oscillating part101that oscillates with respect to an axis of oscillation103, for example by means of a system of bearings or equivalent means.

The oscillating device is also equipped with:a counter-balancing system107acting on and/or is connected to at least the oscillating part101, the amplitude of which is delimited by end-of-stroke springs133;at least one adjustable profile109connected to the oscillating part101by one or more joining or connecting points129;an adjustment system111connected to the adjustable profiles109and to the oscillating part101or to the support105or other fixed part (FIG.1).

The adjustment system111may comprise an actuating device113, cables and/or rods connected in turn to the adjustable profiles109.

According to a specific embodiment, the adjustable profile109is connected to the oscillating part101by at least one connection point129between a leading edge203of the adjustable profile109itself and a pressure centre207thereof (FIG.2).

Advantageously, by means of such a connection, when the adjustment system111implements a passive release adjustment (schematically represented by the arrow125) or interrupts the active adjustment127, the adjustable profile109moves from a position of greatest resistance121with respect to the fluid flow115to a position of least resistance123by the effect of a mechanical moment, which is generated by the force of the same fluid flow115applied in the pressure centre207of the same adjustable profile109, with respect to the connection point129, thus resulting in a constant alignment of the adjustable profile109in a position of least resistance123, when the oscillation angle varies (FIG.9) and/or also in case of changes in the direction of the fluid flow115, thus reducing the damping1003(FIG.10).

According to specific embodiment, the connection points129may be located near or on the leading edge203of the adjustable profiles109(as shown inFIG.2).

FIG.3shows a particular variant of the invention, which employs a further recall system301,303,309located between the oscillating part101and the adjustable profile109, with the function of maintaining the adjustable profile109in the position of least resistance123(when the active adjustment127is not present); this operation can also take place by means of a system for winding the adjustable profiles109with respect to their leading edge203. Advantageously, this recall system301,303,309, in the event of a failure of the adjustment system111, ensures the position of least resistance of the adjustable profile (based on a normally open position). A variant of the preceding embodiment employs a spring313(FIG.2) to keep the adjustment system111released, for example when the adjustable profile109is made with a sail.

In a particular embodiment (FIG.3), the further recall system309is used in order to balance and/or compensate for the weight of the adjustable profile109with respect to the fluid flow115; this balancing action acts in a complementary and/or combined manner with the pressure of the fluid flow115, which continuously moves and orients the adjustable profile109in the position of least resistance123due to the already described mechanical moment of the resulting pressure force.

According to an alternative embodiment, the adjustment system111is connected to the trailing edge205of the adjustable profiles109, advantageously creating more leverage between the trailing edge205itself and the connection point129.

According to another preferred embodiment shown inFIGS.7,8A,8B,8C,8D and8E, the oscillating part101comprises side elements701,703,705arranged laterally to the oscillation plane and having the function of connecting the adjustable profiles109to each other, with the oscillating part101and with the adjustment system111, thus making it possible to use sail-type adjustable profiles without a frame, which do not require a pivot on which to rotate and which make it possible to optimally distribute the pressure of the fluid flow115through several connection points129for each individual adjustable profile109.

By means of the side elements701, the adjustable profiles can be substantially simply hung on said oscillating part.

The orientation and configuration of the side elements701can be achieved through various combinations of rigid and/or hollow parts, depending on the various shapes and structures of the adjustable profiles109used.

Further configurations provide for the use of adjustable profiles109arranged obliquely and/or in a circular fashion, consisting of kites, of various geometrical shapes, with a structure of a rigid, semi-rigid or mixed type, with inserts inflatable by air or other gases that are lighter than the fluid flow115, also with forced sliding channels1601within the surface of the adjustable profiles109and also depending on the position to be adopted (as shown inFIG.16). According to a preferred embodiment, the connection points129are made in the leading edge203and the adjustment system111is connected to the trailing edge205, it being advantageous to use frameless adjustable profiles109of the sail type without frame, due to their better weight/area and weight/strength ratio (when compared to self-supporting or framed profiles).

By means of this method of connecting the profiles with the oscillating part101, the use of bearings or bushings for the rotation of pins can be advantageously avoided with respect to the prior art, thanks to lower maintenance and production costs; this advantage increases when, with the same overall surface area, series of profiles with reduced chords are used (with aerodynamic and adjustment advantages).

Moreover, this configuration, with the light profiles (not self-supporting and without a rigid shaft to rotate) which move with respect to an oscillating part, advantageously allows the overall surface area of the profiles to be increased and/or to increase the length of the oscillating part, thus being able to increase the nominal power of the devices and limiting the relative manufacturing and maintenance costs and overall weight, whilst also increasing the reliability and safety of the device.

According to one variant embodiment, the adjustable profiles109and part of the side elements701can be raised and lowered from the rest of the oscillating part101.

According to a further variant embodiment, an oscillating shaft101is used, the end of which is connected by cables or side elements701to a kite109which may have the leading edge203supported by an air tube (FIG.8E).

The oscillation of the oscillating part101may vary by a few degrees up to the full maximum angle permitted by the structure and may develop with amplitudes with respect to an equilibrium position131or even in another portion of the oscillation plane. The oscillation plane can also have multiple orientations depending on the type of use.

According to a preferred embodiment (FIGS.4,5), the oscillation axis103is misaligned (positioned downwind) with respect to the axis of rotation of a rotatable fifth wheel509in order to facilitate the alignment of the oscillation plane with the fluid flow115.

According to a particular embodiment (shown in theFIG.2), in the adjustment system111it is possible to adjust the maximum force which can be exerted on each or all of the adjustable profiles109, for example by means of a safety spring311or by means of an automatic release or programmed breakage between the adjustment system111and the adjustable profile109; in the presence, for example, of gusts of wind, the maximum pressure exerted on the adjustable profiles109can be predetermined at a safety value, and such a configuration can also be useful in the event of accidental failure of the adjustment system111, allowing the adjustable profiles109to independently arrange themselves in a position of least resistance123.

Further, the adjustable profiles109and the relative adjustment system111may also be configured to adopt the position of least resistance123to the fluid flow115in both the directions of oscillation of the oscillating part101, as shown in the variant embodiment ofFIG.12.

The oscillating part101is coupled to at least one current generator507and this coupling may comprise elements variously configured with each other, such as (FIGS.4,5,7):at least one flywheel513with an axis of rotation parallel or at right angles or inclined to the axis of oscillation103;elastic accumulation systems519that are also adjustable which can be configured together with unidirectional devices517and/or anti-pull joints.

Advantageously, the accelerations typical of the oscillatory movement (maximum at the change of direction) can be transmitted to a storage flywheel513and/or a generator507uniformly without dissipation.

The configuration which comprises the use of a flywheel513with a substantially vertical axis of rotation (FIGS.5,13,15) facilitates the use of large flywheels513, even with configurations where this axis of rotation is orthogonal or inclined with respect to the axis of oscillation103(in the example ofFIG.5advantageously the barycentre of the device lowers, making it more stable during operation). For example, if the device is positioned above a building, the flywheel513can be placed in a basement compartment by connection with a rigid vertical shaft or with an elastic torsion with a axis of rotation coinciding with any axis of rotation of the rotatable fifth wheel509.

According to particular embodiments (FIG.4), the oscillating device comprises an elastic system519placed between the motion transmission system of the oscillation axis103and the storage flywheel513and/or the current generator507with the function of storing and returning the peak forces relative to the maximum accelerations during the oscillation and/or relative to sudden increases in the fluid intensity; the elastic system519can also be installed in combination with unidirectional and/or non-return devices517of the transmission motion.

According to a particular method of adjustment, devices are used for detecting the oscillation speed and/or direction of the oscillating part101, referred to for simplicity as speed sensors603, in order to perform the adjustment (FIG.6).

According to a particular method of adjustment, a programmable unit607is used to receive data from the speed sensors603, from pressure sensors605on the adjustable profiles109(for example, electronic transducers placed on the adjustment cable or torque control systems of the actuating device113), from flow sensors601and finally from production sensors619,621which detect the electricity produced and/or the number of revolutions of the flywheels513.

Advantageously, the programmable unit607implements the passive release adjustment125(or terminates the active adjustment127) and the active adjustment127through the adjustment system111, in order to trigger, maintain and/or increase the oscillation of the oscillating part101according to the forced harmonic motion or also the resonant motion1001(FIG.10), in order to produce electricity with the highest possible efficiency (also by increasing the amplitude and/or the frequency of oscillation).

The programmable unit607may also actuate the passive release adjustment125and active adjustment127in a manner proportional to the intensity of the fluid flow115and/or the oscillation of the oscillating part101and other parameters, so as to obtain different positions of greater resistance121and different positions of lower resistance123of the adjustable profiles109, based on the values detected by the sensors described above and/or other sensors.

In the presence of very strong winds, it is advantageous, for example, to position the adjustable profiles109, during the thrust step117, in a position of greater resistance121which offers less resistance, possibly minimal, with respect to a maximum position of greater resistance121to the flow of fluid115. Moreover, the position of greatest resistance can be determined and varied in the thrust step117in the various angles of oscillation also in order to advantageously maintain the lift of the adjustable profile109and the above-mentioned lift can be detected for example by the pressure sensors605.

It may then be advantageous, for aerodynamic reasons, to adopt the choice of positions of less resistance123, intermediate with respect to a position of minimum possible resistance123, also in the recall step119, for example to avoid turbulence on the adjustable profile109and/or to maintain the lift of the adjustable profile109also in the recall step119(a component of the lift may contribute to feeding the oscillation also in the recall step119) as the oscillation angle varies and also in this case the above-mentioned lift may be detected by the pressure sensors605.

The multiple adjustments, both for the positions of least resistance123in the recall step119, and for the positions of greatest resistance121in the thrust step117, make it possible to use adjustable profiles109having the same surfaces and constructional characteristics in a wide range of intensities of fluid flow115(in the case of winds that can vary, for example, from a few km/h to over 150 km/h).

The programmable unit607can, based on all or part of the values detected by the different sensors, vary the configuration and strength of the counter-balancing system107, as well as the position of an inertia ballast by means of specific mechanisms615.

The programmable unit607may also control a mechanical actuator613connected to the rotatable fifth wheel509for orienting the oscillating device according to the data detected by the flow sensors601, and may, by means of another actuator609, safely place the oscillating device outside the range of the fluid flow115. The programmable unit607can also receive and transmit data and/or commands from and to a remote unit (block617), according to a process schematically represented by the flow diagram inFIG.6.

The operation of the oscillating device according to the invention is described in more detail below.

According to a particular embodiment with the adjustment system111in normally open mode (passive release adjustment125), the fluid passes through the adjustable profiles109of a sail type or other lightweight types (shown inFIG.11) without causing significant displacements of the oscillating part101, since the fluid flow115moves the trailing edge205which is free to move; this mode is particularly advantageous in case of strong and irregular wind as a safety position.

When the adjustment system111implements the active adjustment127, the oscillating part101moves to implement a first step called the thrust step117(FIG.1).

When the adjustment system111implements the passive release adjustment125(or terminates the stress of the active adjustment127) on the adjustable profiles109, they move to a position of less resistance123and the force of the counter-balancing system107, previously loaded during the thrust step117, moves the oscillating part101in the opposite direction, implementing a second step called the recall step119.

When the adjustment system111implements the active adjustment127, the adjustable profiles109move to a position of greatest resistance121and the device resumes the thrust step117.

The oscillating cycle is repeated in the presence of the fluid flow115.

The movement of the oscillating part101, by means of suitable mechanical means of coupling to a current generator507, determines the production of electricity.

According to an innovative adjustment method, starting from an initial position shown inFIG.11(normally open), once the fluid flow115has been detected, the adjustment system111actuates the active adjustment127by blocking and/or moving the adjustable profiles109to a position of greater resistance121and causing the oscillating part101to move in one direction.

When the speed of the oscillating part101detected by the speed sensors603decreases to a predefined value, for example close to zero (indicating that the thrust step is about to be completed), the passive release adjustment125is actuated (or the active adjustment127ends), which brings the adjustable profile101to the position of least resistance123. In this way, the thrust step is fully utilised; the oscillating part101thus moves in the opposite direction, advantageously performing the recall step119.

When, by means of the speed sensors603, the speed of the same oscillating part101approaches a predefined value, for example close to zero (indicating that the recall step in the current direction is about to be completed), the adjustment system111again actuates the active adjustment127, which will again bring the adjustable profile101into a position of greater resistance121, thereby triggering a new thrust step117.

Advantageously, the adjustments are not solely dependent on the angle of oscillation of the oscillating part101, but can be carried out according to the values of speed or its variation or change of direction, in each type of oscillation, in a manner independent of the value of the amplitude and in a manner substantially independent of the fluid flow, the weight of the profiles and a predetermined angle; such adjustments are also made, in an innovative manner, according to the speed (or its variation) of oscillation and/or the change in direction of the oscillating part101by intervening when the two steps of the oscillation (thrust117and recall119) are about to be completed.

These adjustments can be implemented in order to produce a forced harmonic motion (of constant amplitude) or a resonant motion1001(of increasing amplitude) compatible with the maximum amplitude provided by the oscillating device.

Advantageously, therefore, compared to the prior art with the same intensity of fluid flow115it is possible to induce a resonance that widens the oscillation.

According to a particular variant of the adjustment method, the passive release adjustment125, with the resulting position of least resistance123of the adjustable profile109, is maintained for several successive recall steps119, exploiting the inertia of the system, until, again based on values detected by means of the speed sensors603and the production sensors619,621, in the appropriate sequence (at the end of a recall step119with opposite direction to the fluid flow “against the wind” or during a recall step119with the same direction of the fluid flow115“in favour of the wind”), the active regulation127is again actuated to bring the adjustable profile109to a position of greatest resistance121in order to actuate a new thrust step117and to power the oscillation and the production of electricity and/or the rotation of flywheels513connected to at least one current generator507. This has the advantage of maintaining an oscillation and/or the rotation of at least one flywheel513in a way that is useful for the continuous production of electricity with a lower frequency of adjustment compared to traditional oscillating systems, and therefore with less consumption, less wear and tear and greater efficiency (as shown in the diagram inFIG.10).

According to a further embodiment, shown inFIG.13, the oscillating device is installed on suitable floating platforms or on vessels, such as cruise ships or merchant ships, and may comprise devices1301oscillating by the wind and/or oscillating devices1302exploiting the movement of the water which advantageously may keep the current generator507out of the water, maintaining in both embodiments a centre of gravity of the device close to the waterline with obvious constructional and general stability advantages.

According to a preferred embodiment, the invention comprises a series of supports105and oscillating parts101constrained to each other, where the oscillating movement may also be transmitted to a single flywheel513and/or to a single current generator507. According to another variant, the different oscillating parts101and the adjustable profiles109have, on the other hand, autonomous adjustment and/or timing of the period of oscillation in order to more uniformly feed the motion of a single flywheel513and/or current generator507.

According to a further embodiment, shown inFIGS.15and16, the device is used in the flow of liquid fluid115, such as waterways or sea currents, and the adjustable profiles109are in contact with the fluid flow115also using a float connected to the oscillating part101, whilst the support105, with the counter-balancing system107and the current generator507and/or the flywheel513, can be located out of the water.

According to the embodiments in which the flow of water is used, the adjustable profiles109and the relative adjustment system111and the oscillating part101must be suitably configured and dimensioned for this purpose, also with the flow of gas between different zones of the adjustable profiles109depending on the position to be adopted (121or123).

According to a further embodiment, the device can be integrated with photovoltaic systems and/or car charging stations.

It is clear from the description how the invention achieves the intended aims; it is also clear that experts in the trade may make various modifications to the described example embodiments, the scope of protection being defined by the appended claims. Industrial use is also evident.