CA2918777A1 - River turbine - Google Patents

Abstract

The invention relates to a river hydrolene (1) which comprises a fairing (3), a generator (22) driven by a first turbine wheel (5) and housed in a volume formed by the fairing to generate an electric current when a first water stream (9) rotates the first turbine wheel, a passage for a second stream of water (10) passing through the fairing (3) without passing through the first turbine wheel and a second wheel turbine (7) arranged to exert a pumping action on the second stream of water (10). The passage of the second water stream (10) is arranged to cause an acceleration of the water through the first turbine wheel.

Description

River water Technical area The present invention relates to a river tidal stream intended to convert the kinetic energy of a river into electricity.
State of the art

[0002] US3986787, US6013955 and US2007063520 describe submersible turbines capable of producing electricity at from a stream of water, for example from a river. US3986787 documents and US6013955 disclose turbines comprising a water passage turbined in the center, and a fairing or other auxiliary elements around of this water passage. The outer shape of these fairings is optimized from way to create a suction effect of the water flow in the area immediately downstream of the turbine.

US2007063520 discloses a device equipping a water flow channel suitable for hydroelectric production. The The dimensions of the channel and its shape are modified to create a zone of acceleration of the flow of water in which a turbine finds a place.
This solution is particularly suitable for vertical axis turbines.

[0004] US2007284884 discloses a submersible turbine for the generation of electrical energy. The acceleration of the water flow crossing the turbine is caused by a passage of water through a empty central part of the turbine as well as on the periphery of the turbine.

[0005] Document US2009087301 discloses a submersible turbine for the generation of hydroelectric energy. The posterior part of the wheel of the turbine can be equipped with blading for the creation of a pressure drop of the water flow in the region posterior to the rotor. The led as well as the vanes are adjustable.

These various solutions certainly make it possible to accelerate the speed of water passing through the tidal turbine and thus to increase the production electric for a given water flow. The increase remains however modest. It also depends on the initial speed of the water flow, and therefore the flow of the river which can be very variable.

[0007] Furthermore, the accelerated flow of water in the passage which does not crossing not the turbine tends to disrupt the flow of water flow through the turbine, which creates disturbances and a non-laminar flow that affects the total efficiency of the tidal turbine.

The anchoring of turbines at the bottom of a river is the subject of documents US2005285407 and GB2445284. Anchoring devices unveiled include either cable or telescopic pillars.
Brief summary of the invention

An object of the present invention is to provide a tidal turbine of river having an increased suction effect compared to tidal turbines for known river.

Another object of the invention is the realization of a tidal turbine river capable of operating in a river with variable water flows between modest flows and larger flows.

Another object of the invention is the realization of a tidal turbine.
capable of being anchored effectively on any type of nature of bottom ground of a river as well as positioned in height in the flow of water to exploit the most profitable water flow.

According to the invention, these aims are achieved in particular by means of a river turbine with:
a fairing;
a generator driven by a first turbine wheel so to generate an electric current when a first stream of water puts the first turbine wheel in rotation;
a passage for a second flow of water passing through said fairing without passing through the first turbine wheel, and arranged to causing an acceleration of the water through the first turbine wheel;
and a second turbine wheel arranged to exert an action pumping on the second stream of water.

This solution has the advantage over the art in particular to provide a higher degree of efficiency through an effect increased suction compared to known turbines.

According to a particularly advantageous embodiment, the tidal turbine further comprises a water flow separator so as to separate the incoming water flow into a first stream of water and into a second flow of water.

According to one embodiment, the generator is connected magnetically to the first turbine wheel.

According to one embodiment, the generator is connected mechanically at the first turbine wheel.

According to one embodiment, the first turbine wheel includes at least one turbine blade and the second turbine wheel comprising at least one pumping blade.

According to a particularly advantageous embodiment, the first turbine wheel and the second turbine wheel are coaxial and are mounted one inside the other.

According to another particularly advantageous embodiment, the first turbine wheel mechanically drives the second wheel of turbine. In one embodiment, the tidal turbine further comprises a multiplication and / or multiplication of rotational ratios suitable for rotating the pump blades at a speed different from that of turbine blades.

According to one embodiment, a first part of the separator is positioned at the entrance of the fairing, a second part of the separator is positioned between the first turbine wheel and the second wheel of turbine.

According to one embodiment, the tidal turbine further comprises a turbine diffuser in which is positioned a part of the separator.

According to a particularly advantageous embodiment, the fairing further comprises a water flow convergent adapted to increase the water flow rate of the first and / or second flow of water.

According to a particularly advantageous embodiment, the tidal turbine further comprises at least one water flow distributor able to impose a direction on the flow of water of the first stream of water and / or the second stream of water so as to reduce vortex formation in outlet of the turbine. In one embodiment, at least one dispenser of water flow is able to impose separately a fixed direction to the first flow of water and / or the second stream of water. In one embodiment, less a water flow distributor is able to impose a direction variable to the first stream of water and / or the second stream of water. The distributor can be orientable.

According to a particularly advantageous embodiment, the tidal turbine further comprises an anchoring device which comprises a 5 plurality of adjustable voltage cables as well as a plurality of piles adjustable in height, each pile including an anchor point and a base of distribution of the pressure exerted on a bottom of a river.

According to one embodiment, the anchoring device comprises in addition, an automatic vertical positioning control device of the turbine compared to the bottom of the river.

According to a particularly advantageous embodiment, the tidal turbine further comprises a hub having a support function at less a water flow distributor, at the first turbine wheel, at the second turbine wheel, to a protection device and / or to the device anchor.

According to one embodiment, the generator is housed in the hub.

According to another embodiment, the generator is housed in the fairing.

According to a particularly advantageous embodiment, the fairing has an outer parallelepiped shape allowing a modular stack of several turbines without water passages between the tidal turbines.

Brief description of the figures

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:
FIG. 1 illustrates a side sectional view of a tidal turbine of river according to the invention.
Figures 2 and 3 respectively illustrate a side sectional view and a front view of a hydroelectric generating system comprising a plurality of river turbines of the invention.
Figure 4 illustrates the upper part of a river turbine according to the invention.
Figures 5 and 6 illustrate an embodiment of a first wheel of turbine comprising turbine blades encircling a second turbine wheel comprising pumping vanes, according to the invention. FIG. 5 is a front view of FIG.
the C cup.
Example (s) of embodiment of the invention

The present invention relates to a river tidal stream intended to convert the kinetic energy of a stream of water from a river into electricity, which has the particular advantage of having a degree higher efficiency thanks to an increased suction effect compared to known tidal turbines.

[0032] Figure 1 illustrates a river stream turbine according to the invention.
The tidal turbine 1 comprises a turbine 2, a fairing 3 around the turbine and an anchoring device 18,19,20 to anchor the turbine and the fairing to a land 21 in the river bottom.

The internal structure of the fairing 3 comprises a portion convergent 12 upstream. The convergent portion has for example a frustoconical shape, in funnel, to increase the flow velocity through the turbine and thus increase the power that is proportional to the cube of this speed. The input section of the portion convergent 12 may be circular, square or rectangular.

A central zone of the internal structure has a shape cylindrical, in any case a symmetrical shape axially. The central zone fairing 3 houses the turbine 2 comprising the stator and the rotor. The stator includes distributors 13 (or guidelines) of water flow, while the rotor comprises a first turbine wheel 5, and a second wheel of turbine 7.

The turbine comprises a hub 14 preferably disposed at the center of the turbine 2. The hub can be used to support various components of the tidal turbine 1, in particular to the flow distributors 13 of water. It can accommodate a generator.

A downstream portion of the internal structure of the fairing forms a frustoconical diffuser 11, with a gradually increasing diameter. The diffuser11 makes it possible to recover the kinetic energy at the output of the rotor of the turbine and is preferably longer than the convergent 12.
diffuser 11 may comprise a symmetrical section axially while its output may include a square or rectangular section. The section of this downstream portion can also be circular.

The outer structure of the fairing 3 can be parallelepipedic as illustrated in the figures. This parallelepipedic shape allows to stack several tidal turbines arranged in line or in matrix, as illustrated in Figures 2 and 3.

The outer structure of the fairing can also be optimized from way to voluntarily create a difference in the level of sensitive water between upstream and downstream of the tidal stream, creating resistance which tends to form an accumulation of water upstream. This solution allows to increase the water pressure upstream and on the turbines, and therefore increase the efficiency of the turbines. It is also possible to add other restraining elements, for example of dams, so as to increase the difference in level. The shape of fairings and / or external elements can be adapted to the site and each particular water court. The difference in water level is preferably greater than 10 centimeters, for example greater than 20 centimeters.

The rotor of the tidal turbine 1, as illustrated by FIGS. 4-6, is radially divided into two parts. A first turbine wheel 5 is positioned in the outer part while a second turbine wheel 6 is positioned in the inner part. The first turbine wheel 5 includes turbine blades 6 capable of converting the movement linear flow of water in the outer part in a circular motion of the rotor (turbine area), in order to produce electricity.

The second turbine wheel 7 comprises vanes of pumping 8 able to create a suction effect in the water flow in the center (pumping area). It is also possible to reverse the pumping zone and the turbine area. This turbine wheel thus makes it possible to accelerate activates the flow of water through the tidal turbine.

The hydrodynamic profile of the pump blades 8 differs from the turbine blade profile 6. As shown in Figure 6, both profiles can be distinguished by the camber of the blades. The FIG. 6 illustrates an example of a profile of the pump blades 8 and turbine 6, according to sections A and B of FIG. 5. FIG.
additionally, as an indication, the speed triangles at the entrance and the exit of the turbine wheels 5 and 7, where C represents the absolute speed, U "
represents the circumferential speed while W represents the speed relative to the wheel, whose direction is given by the angle of blading.

The tidal turbine 1 preferably comprises a flow separator of water 4 to separate the incoming water flow into a first stream of water 9 and into a second stream of water 10. The first stream of water 9 activates the first wheel 5 (turbine zone) while the second stream 10 is sucked by the action pumping the second wheel 7 (pumping area). This action of pumping creates a Venturi effect, which increases the flow of the first stream 9.
The action of this second wheel 7 makes it possible to obtain a Venturi effect more important compared to that obtained by a turbine with a passage free of water on the periphery and / or center of the turbine.

The water flow separator 4 can be realized by a cone curvilinear able to separate the incoming flow. The length of this cone and its shape may vary from one embodiment to another, in order to maximize the power of the tidal turbine according to the characteristics of the river concerned.
A flow curvilinear cone is also contemplated in the diffuser.

[0044] Advantageously, the separator 4 may comprise several parts: a part 40 may be placed upstream of the turbine wheels 5.7, a portion 41 may be positioned between the two turbine wheels 5.7 and a part 42 can be positioned in the diffuser 11. The downstream part 42 in the diffuser is preferably longer than the front part 40, so to reduce turbulence downstream in the sensitive part where the two flows are join again. The shapes and dimensions of the parts upstream 40 and downstream 42 are adapted to the characteristics of the river concerned, and can be carried out adjusted according to these characteristics.

The generator is coupled to the rotor of the turbine. This coupling can be either directly at the hub of the turbine if the generator is coaxial with the hub, ie at the fairing 3 if the generator is housed in the fairing.

The coupling between the hub and the generator, and therefore the coupling between the two turbine wheels 5.7, may be of mechanical type and / or magnetic, in order to drive the pump 8 bladders through the blades of turbine 6. The blades of turbine 6 and pump 8 can rotate with the 5 same speed of rotation. However, it is also possible to reduction in order to turn the pumping vanes to a different speed, for example faster than the blades of turbine. The adaptation of the dimensions and the shape of the blades of pumping 8 to the flow conditions of the river provides a 10 total efficiency (ie the power of the turbine decreased by power of the pump) higher than the efficiency of a turbine without the pumping device or that of a turbine with simple passage of water.

According to this embodiment, the two turbine wheels 5.7 form a wheel comprising a turbine zone close to the fairing 3 comprising at least one turbine blade 6 on which a first flow of water acts 9. This wheel then comprises a pumping zone, which is positioned radially to the turbine zone and near the hub 14, comprising at least one pumping vane 8 acting on a second water flow 10. A separation of the two streams of water 9 and 10 can be maintained between the vanes 6 and 8 of the two wheels 5 and 7 by a portion 41 water flow separator 4 which is housed between the two wheels 5.7. The movement of the wheel formed by the two wheels 5,7 can be transmitted, mechanically and / or magnetically, to a generator 22 placed at inside the volume formed by the fairing, for example in the fairing 3 (i.e., outside the wheels 5, 7) or in the hub 14 (at interior compared to the wheels 5, 7, but always in the volume delimited by the fairing).

In particular situations of river flow, the zone turbine can be placed inside the pumping area. In this configuration, the first wheel 5 is placed inside the second wheel 7. Thanks to the pumping effect of the flow of water passing through the near zone the fairing 3, the total flow of water that passes through the tidal turbine, and particular flow rate of the flow of water through the turbine area located near of the hub 14, is increased.

It is also possible to provide an electric motor for drive the second pump wheel. It is also possible to check the speed of rotation of the second pump wheel, by example by means of this electric motor.

In one embodiment where the generator is mounted in the fairing, the hub 14 serves as support and guidance for the second wheel 7 pumping, while the first turbine wheel 5 can be supported and / or guided by an outer ring. This ring can transmit its movement, mechanically and / or magnetically, to a generator placed in the fairing 3.

In another embodiment where the generator is located at center, in the axis of the hub, the hub 14 serves as support and guidance to the first turbine wheel 5. The movement of the first turbine wheel 5 is directly transmitted to the generator. The second pump wheel 7 can be supported and / or guided externally by an outer ring. It is also possible to have a pump wheel 7 without guidance on the outside, and therefore without an outer ring.

The distributors 13 (or guidelines) of water flow are arranged at the input of the rotor. The role of distributors 13 is to direct the flow of water upstream of the turbine wheel 5.7 so as to reduce the formation of swirl at the outlet of the turbine wheel 5.7 and therefore the losses within the broadcaster 11.

[0053] To adapt to variations in the flow velocity of the river, a fashion embodiment includes a turbine wheel 5 at a speed variable with orientation of the distributors 13 fixed. Another way of embodiment comprises a fixed speed turbine wheel 5 with distributors 13 with variable orientations.

Distributors 13 may have different profiles between the turbine zone and the pumping zone, in order to better adapt to features specific to turbine blading 6 and pumping vane 8.

The tidal turbine 1 may further comprise a device for protection capable of evacuating sediments and / or debris carried by the stream water entering and which may damage the turbine 2. A grid of protection 15 can be used for this purpose, including the size of its mesh so that its positioning are adapted to cause the least loss of speed of incoming water flow.

The tidal turbine 1 can be anchored to the ground 21 at the bottom of a river by a series of piles 18 and by fixing or tensioning cables 17. One end of the securing cables 17 is attached to an element anchored to the field 21, which may be for example a pile, an anchor or a Dedicated platform, which is placed at or upstream of the tidal turbine 1.
The other end can be connected either directly to the fairing 3 or to a support rod 16 secured to the fairing 3 or the hub 14. A flow of water can thus pass under and over the tidal turbine, constituting so also a passage for the fish.

To allow effective anchoring whatever the nature of the 21 at the bottom of the river, these piles 18 are advantageously equipped an anchor point 20 which sinks into the ground and a plate 21 to distribute the anchoring pressure. Anchorage can be so completed by adjusting the cable tension 17.

The height positioning of the tidal turbine 1 with respect to the field in the bottom of the river has the purpose of being able to enjoy a power of the tidal turbine 1. The ideal height depends on the surface free from the river and the flow of the river, the use of piles 18 adjustable in height and tension cables 17 facilitates the positioning of the tidal stream 1 in the stream of water of the river.

[0059] Definitive positioning can be achieved when Installation of the tidal stream 1 in rivers with a low flow rate, whereas a variable positioning can be obtained by equipping the tidal turbine 1 with a automatic adjustment device.

As mentioned, the external structure of the fairing 3 can take a parallelepiped shape to allow mounting efficient modular of several 1 standard turbines, as illustrated on FIGS. 2 and 3. A system comprising several tidal turbines 1 can be make by stacking several turbines 1 fixing the fairings 3 next to each other. This type of arrangement of a plurality of tidal turbines 1, in height and crosswise with respect to the flow of water of a river, forms an effective obstacle to the flow of water in the river. The fall resulting from this increases the unit power over to a solitary tidal turbine.

Installation, anchoring, positioning and protection of a system comprising a plurality of turbines 1 can use protection and anchoring devices mentioned above.
Advantageously, this system allows synergies between the various 1. The placement of a protective grid 15. For example, can operate reinforcement rods 16 fixed to certain fairings 3 and / or to some hubs 14 of these turbines 1. Similarly, the piles 18 of the anchoring device can retain the tidal turbines 1 placed in the lower line whereas the fixing cables 17 can retain the tidal turbines 1 placed in the upper lines.

Reference numbers used in the figures 1 tidal stream 2 turbine 3 fairing 4 water flow separator first turbine wheel 6 turbine blading 7 second turbine wheel 8 pumping blades 9 first stream of water second stream of water 11 diffuser of the turbine 12 converging water flow 13 water flow distributor 14 hub protective grid 16 reinforcement rod 17 fixing cable 18 anchor pile 19 anchor plate anchor point 21 ground in the bottom of a river 22 generator 40-42 Parts of the water flow separator

Claims (20)

claims 1. River water heater (1) comprising:
a fairing (3);
a generator (22) driven by a first turbine wheel (5) to generate an electric current when a first stream of water (9) the first rotating turbine wheel;
a passage for a second stream of water (10) passing through said fairing (3) without passing through the first turbine wheel, and arranged to causing an acceleration of the water through the first turbine wheel;
characterized by a second turbine wheel (7) arranged to exert an action pumping on the second stream of water (10). 2. River water heater according to claim 1, comprising a water flow separator (4,40,41,42) so as to separate the flow of water entering a first stream of water (9) and a second stream of water (10). 3. river water turbine according to one of claims 1 or 2, wherein the generator (22) is magnetically connected to the first turbine wheel. 4. river water turbine according to one of claims 1 to 3, wherein the first turbine wheel (5) comprises at least one turbine blade (6) and wherein the second turbine wheel (7) comprising at least one pumping blade (8). 5. River water heater according to one of claims 1 to 4, the first turbine wheel (5) and the second turbine wheel (7) being coaxial and mounted one inside the other. 6. River water heater according to one of claims 1 to 5, the first turbine wheel (5) driving mechanically or magnetically the second turbine wheel (7). 7. A river hydrothermal fluid according to claim 6, comprising in in addition to a gearing able to rotate the pump blades at a speed different from that of the turbine blades. 8. river water turbine according to one of claims 2 to 7, wherein a first portion (40) of said separator is positioned at the entrance of the fairing, a second part (41) of said separator is positioned between the first turbine wheel (5) and the second wheel of turbine (7). 9. river water turbine according to one of claims 2 to 8, comprising a turbine diffuser (11), and wherein a portion of said separator is positioned in the turbine diffuser (11). 10. River water heater according to one of claims 1 to 9, wherein said fairing (3) further comprises a flow convergent of water (12) capable of increasing the water flow rate of the first and / or the second stream of water. 11. river water turbine according to one of claims 1 to 10, further comprising at least one water flow distributor (13) adapted to directing the flow of water from the first stream of water (9) and / or the second stream of water (10) to reduce vortex formation at the outlet of the turbine (2). The river water heater according to claim 11, wherein the said at least one water flow distributor (13) is able to impose separately a fixed direction to said first water flow (9) and / or said second stream of water (10). 13. River water heater according to claim 11, wherein said at least one water flow distributor (13) is able to impose a variable direction to said first stream of water (9) and / or said second stream of water (10). 14. River water heater according to one of claims 11 to 13, said water flow distributor being adjustable in orientation. 15. River water turbine according to one of claims 1 to 14, further comprising an anchoring device comprising a plurality of adjustable tension cables (17) and a plurality of piles (18) height-adjustable, each pile including an anchor point (20) and a plate (19) for distributing the pressure exerted on a bottom (21) of a river. 16. A river hydrothermal fluid according to claim 15, said device anchoring device comprising an automatic control device vertical positioning of said turbine (2) relative to said bottom (21). 17. River water heater according to one of claims 1 to 16, further comprising a hub (14) having a support function at least one distributor (13) of water flow, at the first turbine wheel, at the second turbine wheel, to a protection device (15) and / or anchoring device. 18. A river hydrothermal fluid according to claim 17, said generator (22) being housed in the hub (14). 19. river water turbine according to one of claims 1 to 17, said generator (22) being housed in the fairing (3). 20. river water turbine according to one of claims 1 to 19, said fairing (3) having an outer parallelepiped shape allowing a modular stack of several turbines without water passages between tidal turbines.