WO2014118088A1

WO2014118088A1 - Turbine for hydroelectric generator for rivers and hydroelectric plant comprising such turbine

Info

Publication number: WO2014118088A1
Application number: PCT/EP2014/051397
Authority: WO
Inventors: Adriano GIORIO
Original assignee: Giorio Adriano
Priority date: 2013-01-29
Filing date: 2014-01-24
Publication date: 2014-08-07
Also published as: ITPD20130019A1

Abstract

Turbine (10) for a hydroelectric generator for rivers (11), which comprises a supporting structure (12) for a chassis (13) that rotates about a substantially vertical rotation axis (14), in the configuration for use, which in turn supports, pivoted on axes (15, 16) that are parallel to each other and to the rotation axis (14) of the rotating chassis (13), a plurality of vanes (17, 8, 19, 20, 21), the vanes being designed to assume, depending on the position with respect to the flow, - an active configuration for affecting the flow of water with the free edge (22, 23, 24, 25, 26) of the vane in abutment against a corresponding rotation-preventing locator (27, 28, 29, 30, 31) that is integral with the rotating chassis (13), - an inactive configuration with free orientation.

Description

TURBINE FOR HYDROELECTRIC GENERATOR FOR RIVERS AND HYDROELECTRIC PLANT COMPRISING SUCH TURBINE

The present invention relates to a turbine for a hydroelectric generator for rivers, and a hydroelectric plant comprising such turbine.

Nowadays the use of micro-hydroelectric and mini-hydroelectric plants is increasingly gaining ground.

The terms micro-hydroelectric and mini-hydroelectric are used to designate small hydroelectric plants of a power lower than 100 kW and 1 MW respectively, which are capable of producing electricity from the normal course of the water of rivers and of mountain streams.

These watercourses can represent an important alternative in terms of energy savings, enabling major savings in terms of energy consumption for many small mountain or suburban communities.

In Italy the hydroelectric sector is the leading producer of renewable energy, and contributes 15-20% of the national energy needs.

For the most part, this energy is produced in the big dams that are mainly located in the north of Italy.

The big hydroelectric plants have already tapped most of the existing potential of geomorphological formations in Italy, and it does not appear to be possible to build more of these dams.

Hydroelectric power is in fact a resource that is closely linked to the characteristics of the chosen landscape and sites.

Differently, mini-hydroelectric power offers great potential for investment.

Hydroelectric energy is the electricity that can be obtained from a mass of water by exploiting the potential energy that it yields with a waterfall or with a downhill flow.

An initial, summary differentiation of the various types of plants can be made, between plants that use a waterfall due to a drop in height and plants that take advantage of the speed of currents. In the first case, the power of the system depends on two things: the head (the difference between the height where the flooded water resource is available and the height where that water is returned to the environment after passing through a turbine) and the flow rate (the mass of water that flows through the machine per unit of time).

In the second case, the power is determined on the basis of the velocity of the water mass and by the active surface of the turbine.

An additional distinction between hydroelectric power stations is based on the type of station: run-of-the-river, dammed (using a reservoir with controlled outflow), and pumped- storage.

Power stations of the first type, i.e. run-of-the-river, are located on watercourses; they have no capacity to adjust flow rates, therefore the production of electricity is totally dependent on the flow rate of the river, and this normally results in seasonal variations in production.

Since they operate without interruption, they are capable of covering basic electricity needs.

Power stations of the second type, i.e. dammed, use water collected in natural or artificial reservoirs.

They are capable of adjusting flow rates and, since they can be started and stopped within a few minutes, they can be used as energy storage devices to cover the load during periods of high power demand.

Generally, dammed hydroelectric plants generate more power than the other types of plants, but, against this, they have an environmental impact that is often very negative on the fauna and flora, with all the drawbacks that follow from this.

Power stations of the third type, i.e. pumped-storage, have an upper reservoir, known as the storage reservoir, and a lower reservoir, known as the drawdown reservoir. At periods of low demand, when electricity tariffs are lower (at night), water is raised from the lower reservoir to the upper reservoir by way of a pump, to be reused later in a turbine to produce electricity during periods of peak demand.

The advantage of power stations of this type lies in the difference in commercial value of the electricity used for pumping (low night-time rates) and the electricity produced by the plant (high daytime rates) when demand rises, but building such a power station is very invasive to the environment, and requires the construction of extremely expensive structures.

Thus in general hydroelectric plants, although they do not emit pollutant substances during their operation, still require the building of works with a high environmental impact on soil conservation and on other uses of water resources.

The aim of the present invention is to provide a turbine for hydroelectric generator for rivers, which is capable of overcoming the above-mentioned limitations of conventional hydroelectric plants.

Within this aim, an object of the invention is to provide a hydroelectric plant that comprises such a turbine.

Another object of the invention is to provide a turbine for a hydroelectric generator, and a plant that comprises such a turbine, which make it possible to take optimal advantage of the kinetic energy of rivers with relatively low flow speeds.

Another object of the invention is to provide a turbine and a plant the installation of which on a river requires minimal intervention on the landscape, and thus an extremely low environmental impact, causing no damage of any kind to local flora and fauna.

Another object of the invention is to provide a turbine and a hydroelectric plant with a higher yield than similar conventional plants for rivers.

Another object of the invention is to provide a turbine for a hydroelectric generator for rivers and a hydroelectric plant that comprises such turbine, both of which can be provided with conventional technologies and equipment. This aim and these and other objects which will become more evident hereinafter are achieved by a turbine for a hydroelectric generator for rivers, characterized in that it comprises a supporting structure for a chassis that rotates about a substantially vertical rotation axis, in the configuration for use, and which in turn supports, pivoted on axes that are parallel to each other and to the rotation axis of the rotating chassis, a plurality of vanes, said vanes being designed to assume, depending on the position with respect to the flow,

- an active configuration for affecting the flow of water with the free edge of the vane in abutment against a corresponding rotation-preventing locator that is integral with said rotating chassis,

- an inactive configuration with free orientation.

Advantageously, a hydroelectric plant for rivers, comprising a turbine as described above, is characterized in that it comprises a floating structure to be fixed to the shore of a river, inside which there is a water transit channel in which at least one turbine as described above is immersed, said plant comprising

- means for adjusting and controlling the direction of the flow of water fed to the turbine,

- means for transmitting the torque from said rotating chassis to an electricity generator, which is also on board the floating structure.

Further characteristics and advantages of the invention will become more apparent from the description of a preferred, but not exclusive, embodiment of the turbine and of the plant according to the invention, which are illustrated by way of non-limiting example in the accompanying drawings wherein:

- Figure 1 is a schematic plan view of a turbine according to the invention;

- Figure 2 is a sectional view along a line perpendicular to the rotation axis of the turbine in Figure 1 ; - Figure 3 is a side view of the turbine according to the invention as in Figures 1 and 2;

- Figure 4 is a rear view of the turbine according to the invention;

- Figures 5 and 6 show the geometry of a vane of a turbine according to the invention;

- Figure 7 is a schematic plan view from above of a hydroelectric plant according to the invention;

- Figure 8 is a side view of the hydroelectric plant in Figure 7;

- Figure 9 is a rear view of the hydroelectric plant in Figures 7 and 8. With reference to the figures, a turbine for a hydroelectric generator for rivers is generally designated with the reference numeral 10.

The flow of water of a river is generally designated with the reference numeral 11.

Such turbine 10 comprises a supporting structure 12 for a chassis 13 that rotates about a substantially vertical rotation axis 14, the latter shown in Figure 3, in the configuration for use, which in turn supports, pivoted on axes that are parallel to each other, for example the axes 15 and 16 in Figure 3, and are parallel to the rotation axis 14 of the rotating chassis 13, a plurality of vanes, five in the present embodiment, and respectively 17, 18, 19, 20 and 21.

Such vanes 17, 18, 19, 20 and 21 are designed to assume, depending on the position with respect to the flow 11 ,

- an active configuration for affecting the flow of water with the respective free edge, 22, 23, 24, 25 and 26 in Figure 2, of the vane in abutment against a corresponding rotation-preventing locator, 27, 28, 29, 30 and 31, that is integral with the rotating chassis 13,

- an inactive configuration with free orientation.

In the embodiment described herein, by way of non-limiting example of the invention, the supporting structure 12 is constituted by a quadrangular chassis 32 made of metallic profiles, on which the following are fitted: an upper cross-member 33 and, by way of two opposite brackets 34 and 35 that extend downward and are clearly visible in Figure 4, a lower cross-member 36, the rotation shaft 37 of the rotating chassis 13 being pivoted between the cross-members.

The quadrangular chassis 32 is designed to be integrated in a floating structure of a hydroelectric plant, also according to the invention, described in more detail below.

In the present embodiment, the rotating chassis 13 is constituted by two symmetrical metallic rings, an upper one 38 and a lower one 39, which are fixed to corresponding flanges 40 and 41 of the rotation shaft 37 by way of spokes, for example upper spokes 42 and lower spokes 43.

Between the two metallic rings 38 and 39, at each pair of corresponding spokes, the vanes 17, 18, 19, 20 and 21 are pivoted.

The pivoting is provided, for example, for each vane, by an upper pivot and a lower pivot, which protrude respectively from the upper and lower rings, and are adapted to be inserted in a respective bush mounted at the upper and lower ends of the pivoting portion of each vane.

The rotation-preventing locators 27, 28, 29, 30 and 31 are, for example, each provided by a metallic protrusion, such as a screw, a pin, a block or other, similar element, each protruding from a spoke 42 and 43 or a flange 40 and 41 so as to be arranged so as to interfere with the rotary motion of a corresponding vane, affecting one of its edges.

Each vane 17, 18, 19, 20 and 21 is made of pressed and bent metal sheet, according to a curved profile that is shown clearly in Figure 6, which is designed to enable the vanes to block and deflect the flow of water in the most mechanically efficient manner in order to obtain the best possible yield in the conversion of the kinetic energy of the water to mechanical energy.

The vanes 17, 18, 19, 20 and 21 are mounted so as to offer their concavity to the flow of water when they are in the active configuration.

The supporting structure 12 also has a first baffle 44, with variable trim, that is arranged at a region for the access 45 of the flow of water to the turbine 10.

Such first baffle 44 deflects the flow of water so as to increase the flow rate and deflect it toward the part of the turbine 10 where the vanes are arranged in the active configuration, i.e. with an edge resting on the respective rotation-preventing locator.

Advantageously, there is a second baffle 46 that is fixed and opposite to the first one, and is adapted to prevent the water from flowing externally around the vanes.

The first and second deflectors thus extend until they are proximate to the rotating chassis 13.

Operation of turbine 10 according to the invention is as follows.

The turbine 10 is immersed in the river, and the flow of water is channeled toward the part of the rotating chassis 13 in which the vanes assume the active configuration.

Such active configuration is defined by the fact that the free edges of the vanes come into abutment against the corresponding rotation-preventing locators; in such active configuration the vane is prevented from rotating by the thrust exerted by the flow of water on one side and by the temporary stopping action exerted by the rotation-preventing locator.

In such situation the vane pushes, so as to make it rotate, the rotating chassis 13, with which means are associated for transmitting the torque to a generator, described in more detail below.

As clearly shown in Figure 2 for the vane 19, following the rotation of the rotating chassis 13, the vane stops blocking the flow in a mechanically useful manner, and from that moment on the vane is no longer pushed against its rotation-preventing locator and is free to orient itself, moved by the flow of water, arranging itself freely to ideally follow the flow lines of the river.

In such inactive configuration the vane minimizes its opposition to the rotation of the rotating chassis 13, offering the least resistance possible to the flow.

Following the continuous rotation of the rotating chassis 13, each vane at each revolution alternates between the active configuration and the inactive configuration.

Such technical solution makes it possible to obtain the maximum yield from the turbine 10, since the resisting forces offered by the fluid on the same vanes during the rotation of the rotating chassis 13 are minimized.

Such a turbine is to be considered optimal for operating in river waters with speeds of no less than 0.3 meters per second.

This makes such turbine very attractive for application in a hydroelectric plant for rivers that are typical for example of northern Italy, and also in many other parts of the world.

The invention also relates to a hydroelectric plant 50, as in Figures 7, 8 and 9, for rivers, which comprises a turbine 10 as described above.

Such plant 50 comprises a floating structure 51 that is to be fixed to the shore 52 of a river 11.

Within the floating structure 51 there is a water transit channel 53 in which at least one turbine 10 is immersed.

Such plant 50 comprises

- means 54 for adjusting and controlling the direction of the flow of water fed to the turbine, i.e. the deflectors 44 and 46 described above,

- means 56 for transmitting the torque from the rotating chassis 13 to an electricity generator 57, which is also on board the floating structure 51.

Such plant 50 also conveniently comprises means 55 for adjusting the immersion of the turbine 10 and of the waterline of the floating structure 51.

The floating structure 51 is fixed to the shore 52, or to the bed of the river, by way of at least one stake-pillar, for example two stake-pillars 58 and 59. The immersion adjustment means 55 are constituted by a series of hermetic chambers, for example three for each side of the floating structure 51, of which four, 60, 61 , 62 and 63, are shown in Figures 8 and 9.

Depending on the degree of flooding of each chamber, the inclination of the floating structure is adjusted and the structure is raised or lowered with respect to the water surface, optimizing the immersion of the turbine 10.

On board the floating structure 51, in addition to the turbine 10 and the corresponding generator 57, there is also an electrical switchboard 70, for managing the floating structure and for converting the electrical power generated by the generator.

The electrical cable, or the electrical cables if there are more than one, leave the electrical switchboard 70 and, by way of the columns 58 and 59, extend to the riverbank, protected by adapted galvanized protection tubes 72.

The region for the access 45 of the water to the turbine 10 is protected by an external grille 74, and by a debris deflector 75, which extend away from the floating structure 51 at the level of the water surface.

In the present embodiment, the means 56 for transmitting the torque from the rotating chassis 13 to an electricity generator 57 are constituted by a ring gear 76, clearly visible in Figure 3, which is defined externally to the upper metallic ring 38, and is adapted to mesh with a driven gear 77 that is constituted by rollers 78 with axes parallel to the rotation axis of the driven gear 77, the teeth of the ring gear being designed to mesh between two laterally adjacent rollers 78.

The driven gear 77 is keyed on a rotation shaft that supports above it a pulley 80 adapted to transfer the torque to the generator 57.

Such a hydroelectric plant 50 can be provided with one or more turbines 10, and thus with a corresponding number of electricity generators in order to supply current in a manner very much adaptable to the needs of the surrounding communities.

Such hydroelectric plant 50 furthermore has substantially no environmental impact, being supported by a floating structure that does not require modifications either to the river or to the riverbanks, except for the laying of the anchoring poles and of the tubes for protecting the electrical cables.

In practice it has been found that the invention fully achieves the intended aim and objects.

In particular, with the invention a turbine for a hydroelectric generator and a plant that comprises such a turbine are provided which make it possible to take optimal advantage of the kinetic energy of rivers with relatively low flow speeds, for example down to a minimum of 0.3 meters per second.

Furthermore, with the invention a turbine and a plant are provided, the installation of which on a river requires minimal intervention on the landscape, and thus an extremely low environmental impact, causing no damage of any kind to local flora and fauna.

What is more, with the invention a turbine and a hydroelectric plant are provided which have a higher yield than similar conventional plants for rivers, thanks to the particular structure of the turbine with vanes rotating about an axis thereof and thanks to the specially-designed configuration of the profile of the vanes.

In addition, with the invention a turbine for a hydroelectric generator for rivers and a hydroelectric plant that comprises such turbine are provided, both of which can be provided with conventional technologies and equipment.

Hydroelectric plants of this type can be built wherever there is a constant and sufficient flow of water.

Any public or private agency, once the necessary authorizations have been obtained, can start a business to exploit a small watercourse in order to draw electricity to be sold on to an operator of the national grid, or for own use, supporting a business similar to photovoltaic energy.

The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In practice the materials employed, provided they are compatible with the specific use, and the contingent dimensions and shapes, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. PD2013A000019 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, such reference signs have been inserted for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

1. A turbine (10) for a hydroelectric generator for rivers (11), characterized in that it comprises a supporting structure (12) for a chassis (13) that rotates about a substantially vertical rotation axis (14), in the configuration for use, which in turn supports, pivoted on axes (15, 16) that are parallel to each other and to the rotation axis (14) of the rotating chassis (13), a plurality of vanes (17, 18, 19, 20, 21), said vanes being designed to assume, depending on the position with respect to the flow,

- an active configuration for affecting the flow of water with the free edge (22, 23, 24, 25, 26) of the vane in abutment against a corresponding rotation-preventing locator (27, 28, 29, 30, 31) that is integral with said rotating chassis (13),

- an inactive configuration with free orientation.

2. The turbine according to claim 1 , characterized in that the supporting structure (12) is constituted by a quadrangular chassis (32) made of metallic profiles, on which the following are fitted: an upper cross- member (33) and, by way of two opposite brackets (34, 35) that extend downward and are clearly visible in Figure 4, a lower cross-member (36), the rotation shaft (37) of the rotating chassis (13) being pivoted between said cross-members.

3. The turbine according to the preceding claims, characterized in that said rotating chassis (13) is constituted by two symmetrical metallic rings, an upper one (38) and a lower one (39), which are fixed to corresponding flanges (40, 41) of the rotation shaft (37) by way of upper spokes (42) and lower spokes (43), said vanes (17, 18, 19, 20, 21) being pivoted between the two metallic rings (38, 39).

4. The turbine according to the preceding claims, characterized in that said rotation-preventing locators (27, 28, 29, 30, 31) are each provided by a metallic protrusion, such as a screw, a pin, a block or other, similar element, each protruding from a spoke (42, 43) or a flange (40, 41) so as to be arranged so as to interfere with the rotary motion of a corresponding vane, affecting one of its edges.

5. The turbine according to the preceding claims, characterized in that each vane (17, 18, 19, 20, 21) is made of pressed and bent metal plate, according to a curved profile that is shown clearly in Figure 6.

6. The turbine according to the preceding claims, characterized in that said supporting structure (12) has a first baffle (44), with variable trim, that is arranged at a region (45) for the access of the flow of water to the turbine (10).

7. The turbine according to the preceding claims, characterized in that it has a second baffle (46) that is fixed and opposite to the first one and is adapted to prevent the flow from flowing externally around the vanes.

8. A hydroelectric plant (50) for rivers, comprising a turbine (10) according to the preceding claims, characterized in that it comprises a floating structure (51) to be fixed to the shore (52) of a river, inside which there is a water transit channel (53) in which at least one turbine (10) according to the preceding claims is immersed, said plant comprising

- means (54) for adjusting and controlling the direction of the flow of water fed to the turbine (10),

- means (56) for transmitting the torque from said rotating chassis

(13) to an electricity generator (57), which is also on board the floating structure.

9. The plant according to the preceding claim, characterized in that said floating structure (51) is fixed to the shore (52) or to the bed of the river by way of at least one stake-pillar, for example two stake-pillars (58, 59), and comprises means (55) for adjusting the immersion of the turbine (10) and the waterline of the floating structure (51).

10. The plant according to claims 8 and 9, characterized in that said immersion adjustment means (55) are constituted by a series of hermetic chambers, for example three for each side of the floating structure (51), four of which (60, 61 , 62, 63) are shown in Figures 8 and 9.

11. The plant according to claims 8 to 10, characterized in that on board the floating structure (51) there is also an electrical switchboard (70) for managing the floating structure and for converting the electrical power generated by the generator.

12. The plant according to claims 8 to 11, characterized in that said region (45) for access of the water to the turbine (10) is protected by an external grille (74) and by a debris deflector (75).