WO2004074679A2

WO2004074679A2 - Windmill

Info

Publication number: WO2004074679A2
Application number: PCT/CA2004/000230
Authority: WO
Inventors: René LANDRY, Jr.; Daniel J. Vachon
Original assignee: Eole Canada Inc.
Priority date: 2003-02-19
Filing date: 2004-02-19
Publication date: 2004-09-02
Also published as: CA2419222A1; WO2004074679A3

Abstract

A windmill turbine (1) with a central vertical axis having a rotor (3) and a series of blades (5) operationally connected to the rotor (3) for receiving wind and allowing a rotation of the rotor (3). The blades (5) are provided with internal heat-conducting channels (7) distributed within the blades (5) for receiving a heat-conducting liquid. The windmill also has an electrical generator operationally connected to the rotor (3) for generating electricity. The generator has a liquid cooling system connected to the internal heat conducting channels (7). The cooling system receives the heat-conducting liquid having run through the internal heat-conducting channels (7), so that in operation, the heat-conducting liquid heats the blades (5) and cools down before returning to the cooling system of the generator. The blades (5) may be provided with riblets (13) and the windmill may have an adjusting system for adjusting a position angle of the blades (5).

Description

WINDMILLS

FIELD OF THE INVENTION

The present invention relates to improvements in windmills, in particular with respect to vertical axis windmill turbines.

BACKGROUND OF THE INVENTION

There exist two principal types of windmills. The windmills with horizontal axis or propeller type blades are well known and have been commercialized for a long time. The development of vertical axis windmills is more recent and offers many exploitation possibilities at commercial and even residential levels.

SUMMARY OF THE INVENTION

According to the present invention, there is provided a windmill turbine with a central vertical axis comprising: a rotor; a series of blades operationally connected to the rotor for receiving wind and allowing a rotation of the rotor, the blades being provided with internal heat-conducting channels distributed within the blades for receiving a heat- conducting liquid; and an electrical generator operationally connected to the rotor for generating electricity, the generator having a liquid cooling system connected to the internal heat-conducting channels, the cooling system receiving the heat-conducting liquid having run through the internal heat-conducting channels, so that in operation, the heat-conducting liquid heats the blades and cools down before returning to the cooling system of the generator.

According to another aspect of the present invention, there is provided a windmill comprising: a rotor; and a series of blades operationally connected to the rotor for receiving wind and allowing a rotation of the rotor, the blades having an inner surface and an outer surface, the outer surface being provided with riblets for reducing a drag coefficient of the blades and turbulence generated when the rotor is rotating. According to yet another aspect of the present invention, there is provided a windmill turbine with a central vertical axis comprising: a rotor; a series of blades operationally connected to the rotor for receiving wind and allowing a rotation of the rotor, the blades being connected to the rotor via transversal rods pivotally attached to upper and lower edges of each blade for holding each blade on a peripheral vertical axis that is equidistant to the vertical axis of the windmill; and blade adjusting means for controlling a position angle of each of the blades, the adjusting means having radial rods respectively and pivotally connected to each blade and to a control plate mounted on the rotor, the control plate being activated by a motor controlled by a computer so as to move each radial rod with respect to each transversal rod for automatically adjusting the position angle of the blades according to predetermined parameters.

The invention, its use and its advantages will be better understood upon reading of the following non-restrictive description of preferred embodiments thereof, made with reference to the accompanying drawings, in which like numbers refer to like elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a perspective view of a vertical axis windmill according to a preferred embodiment of the present invention.

FIG 2 is perspective view of a blade provided with internal heat-conducting channels used in blades of a windmill turbine according to a preferred embodiment of the present invention.

FIG 3 is a detailed view of the circle indicated by reference character III of FIG 2.

FIG 4 is a perspective view of a blade provided with a secondary electrical defrosting system used in a blade of a windmill turbine according to a preferred embodiment of the present invention. FIG 5 is a partial front view of a blade provided with riblets used in a windmill turbine according to a preferred embodiment of the present invention.

FIG 6 is a section view taken at line A-A of FIG 5.

FIG 7 is a perspective view of the windmill turbine shown in FIG 1 without a cover and showing a weight system for controlling the inertia of the windmill turbine according to a preferred embodiment of the present invention.

FIG 8 is is a perspective and partial view of certain elements of the windmill turbine shown in FIG 7 at a low speed operation position.

FIG 9 is a top view of the windmill shown in FIG 8.

FIG 10 is a perspective partial view of certain elements of the windmill shown in FIG 7 at high speed operation position.

FIG 11 is a top view of the windmill shown in FIG 10.

FIG 12 is a perspective partially exploded view of certain elements of the windmill shown in FIG 7.

FIG 13 is a detailed view of the circle indicated by reference character B in FIG 12.

FIG 14 is a side view of the windmill shown in FIG 7.

FIG 15 is a section view taken at line AA-AA of FIG 14.

FIG 16 is a perspective view of a wind deflection system of the windmill turbine shown in FIG 15.

FIG 17 is a perspective view of one of the elements of the wind deflection system including a wind vane and a gear system used in a windmill turbine according to a preferred embodiment of the present invention.

FIG 18 is an exploded perspective view of the elements shown in FIG 17. FIG 19 is a perspective view of three windmill turbines stacked one on top of the other according to a preferred embodiment of the present invention.

FIG 20 is a perspective view of a windmill turbine with vertical axis having inclined and doubled blades according to a preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS 1 to 3, the present invention firstly concerns a windmill turbine 1 with vertical central axis. The windmill 1 has a rotor 3 and a series of blades 5 operationally connected to the rotor 3 for receiving wind and allowing a rotation of the rotor 3. The blades 5 are provided with internal heat- conducting channels 7 distributed within the blades 5 for receiving a heat- conducting liquid. The windmill 1 also has an electrical generator operationally connected to the rotor 3 for generating electricity. The generator has a liquid cooling system that is connected to the internal heat-conducting channels 7 distributed in the blades 5. The cooling system of the generator receives the heat-conducting liquid having run through the internal heat- conducting channels 7 distributed in the blades 5, so that during operation, the heat-conducting liquid heats the blades 5 and cools down before returning to the cooling system of the generator.

Preferably, the electrical generator is located underneath the rotor 3 of the windmill 1 in a space 30. As is discussed further below, the electrical generator may be selected among several suitable electrical generators.

Referring to FIGS 1 and 7, there may be six blades 5 mounted on the windmill 1 , but those skilled in the art will understand that any suitable number of blades may be used in order to achieve the same results.

Referring to Fig. 4, the windmill 1 may further have a secondary electrical defrosting system including a metallic filament 9 integrated on the surfaces of the blades 5. The secondary electrical defrosting system heats up the metallic filament 9 by running a current through it so as to remove frost or ice that accumulates on the blades 5 in a similar way as a defrosting system used in the rear window of a vehicle.

Preferably, each of the blades 5 is streamlined and shaped in such a way so as to allow the integration of a miniature tube therein. The miniature tube may be made of a light alloy and acts as the heat-conducting channel 7 defined above. The tube has two openings. The first opening is located on the upper side edge of each vertically positioned blade 5 and allows the entry of the heat-conducting liquid into the blade 5, which has been heated by the electrical generator. The other opening of the tube is located on the lower side edge of the blade 5 and permits the outflow of the heat-conducting liquid out from blade and back into the cooling system of the electrical generator.

One preferential advantage of the above liquid heat-conducting system in the blades 5 is that it warms up the blades 5 and may allow the defrosting of the blades 5 during extreme cold and/or frost conditions. Indeed, without this heat-conducting system, frost and ice could accumulate on the blades 5 of the windmill 1 , which would result in considerable losses in energy production, and this could also damage certain components of the windmill 1. Secondly, another advantage of this heat-conducting system is that during the rotation of the blades 5, these are subjected to non-negligible cooler air flows on the inner 62 and outer side 60 of each blade 5, which in turn cool down the heat- conducting liquid running inside of each blade 5. In this way, the heat- conducting liquid which is cooled by the blades 5 also cools down the electrical generator when it returns to its cooling system.

This heat-conducting system may therefore defrost and/or de-ice the blades 5 in very cold conditions. The heat-conducting system may still be useful in more warmer climate conditions because the blades 5 act as a radiator when the heat-conducting liquid cools down the electrical generator.

Preferably, a closed-loop pump system pumps the liquid that is heated by the electrical generator into a channel located in the central shaft of the windmill turbine 1. The liquid reaches the upper end of the central shaft and is divided among the available blades 5 which are mounted on the windmill 1. Each blade 5 is held in place by transversal rods 11 that extend from the central shaft. These transversal rods 11 may be provided with internal channels through which the heat-conducting liquid is directed toward the heat- conducting channels 7 integrated in each of the blades 5.

As mentioned above, the heat-conducting liquid system can be assisted by a secondary electrical system which is similar to that used for defrosting the rear windows of vehicles. Preferably, the blades 5 are made of fiberglass and the metallic filament 9 is integrated during the manufacturing process of each blade 5 so as to cover its entire surface. A small electric current is applied to the metallic filament 9 of each blade 5 when the heat conducting liquid is unable to totally defrost the surface of the blades 5. The metallic filament 9 may be located inside one of the external layers of the blades 5 made of fiberglass and may be used to assist the heat-conducting system in situations where the liquid is not available or is not sufficient.

It should be noted that the electrical defrosting system could be used to warm up the blades 5 without using the heat-conducting liquid system. It should also be noted that either the heat-conducting liquid system or the electrical defrosting system could also be used in a horizontal axis windmill.

USE OF RIBLETS ON THE OUTER SIDE OF THE BLADES

Any object that is moving in the air generates aerodynamic turbulence. This is the reason that the shape of a wing of an airplane flies better than a circular shaped object such as a golf ball for example. In this regard, if one would want to improve the efficiency of a golf ball, it has been proven that adding small indentations on its surface reduces drag by as much as 10 to 20%.

In an airplane, more than 50% of the global drag is due to the skin friction that causes turbulence on the fuselage and on the wings. In this context, riblets are defined by NASA as being V-shaped grooves or riblets grooves that are aligned with the aerodynamic shape of the wing for reducing turbulence caused by the skin friction. Typically, in the field of civil aviation, the height of the riblets is about 0.001 inch or 0.00252 cm. In practice, the V-shaped riblets have demonstrated that they can reduce the skin friction in the order of 5 to 10% in many aerodynamic fields (aeronautic, sport, hydraulic, etc.). This technology has been developed by NASA while analyzing the displacement of sharks in water. Indeed, it was demonstrated that the skin of sharks has small channels that are similar to the above described riblets.

Referring to FIGS 2, 5 and 6, according to another aspect of the present invention, the outer side 60 of each blade 5 is provided with riblets 13 (which are best shown in FIGS 5 and 6) for reducing a drag coefficient of the blades 5. Referring to FIG 2, the outer side 60 of the blade 5 is opposed to the inner side 62 of the blade 5. The outer side 60 corresponds to the upper portion of a typical curved airplane wing as is further described below. Preferably, each riblet 13 is V-shaped. The spacing between the riblets 13 can be of the order of 150 micrometers or 0.0004 inches. Of course, persons skilled in the art will understand that other shapes of the riblets can also reduce the drag coefficient of the blades 5 in a suitable manner.

The inclusion of riblets 13 on the outer side of the blades 5 of the windmill turbine 1 according to the present invention contributes to the increase of the overall performances thereof. The manufacture of riblets 13 on the blades 5 can be made in different ways such as by directly molding them on the outer side of fiberglass made blades or by adding a ready-made film provided with riblets that is developed by the 3M company, for example. In addition to reducing skin friction by 5 to 10% and improving the aerodynamic of the blades 5, these riblet grooves 13 reduce the lateral turbulence of the blades 5 and also turbulence in front of the windmill 1. All of this improves the global performance of the windmill and it reduces the vibrations in the structure of the windmill.

AUTOMATIC ADJUSTMENT OF THE POSITION ANGLE OF THE BLADES AND CONTROL OF THE INERTIA OF THE ROTOR Referring to Figs 7 to 13, according to another aspect of the present invention the blades 5 of the windmill 1 are connected to the rotor 3 via transversal rods 11 pivotally attached on the upper and lower edges of each blade 5 for supporting each blade 5 on a peripheral vertical axis that is equidistant from the vertical axis of the windmill 1. The windmill 1 also has an adjusting system connected to the blades 5 for controlling the position angle of each of the blades 5. The adjusting system include radial rods 41 that are respectively pivotally connected to each blade 5 and to a control plate 12 mounted on the rotor 3. The control plate 12 is activated by a motor controlled by a computer so that when the control plate 12 is rotated, it moves each radial rod 41 with respect to each transversal rod 11 and automatically adjusts the position angle of the blades 5 according to predetermined parameters.

Preferably, the windmills 1 according to the present invention are provided with a mechanical positioning system that is simple and robust and allows varying the position angle of the blades 5. As mentioned above, an onboard computer connected to the windmill 1 controls the position angle of the blades 5 according to different predetermined parameters such as the wind speed, the rotation speed of the central shaft (RPM of the rotor), wind turbulence, wind gusts and/or any other meteorological conditions or any other parameters. The computer controls a step motor which activates the control plate 12 that is used for moving each blade 5 as is best illustrated in Fig 13. In this example, the control plate 12 is connected to six radial rods 41 which are in turn each connected to a first pivot on a pivot mechanism 52 located on the top of each blade 5. Each pivot mechanism 52 has a second pivot point that is connected to the corresponding transversal rod 11. In this way when the radial rods 41 are moved, these act as levers with respect to the transversal rods 11 onto which the blades 5 are mounted so that the blades 5 are thus pivoted around their own peripheral vertical axis at a pivot point connecting each transversal rod 11 to each blade 5.

Referring to Figs 8 and 9, it should be noted that, for facilitating starting the rotation of the rotor 3, the blades 5 are opened at maximum for facilitating wind penetration into the rotor 3. This maximizes wind forces on the blades 5 and thereby the rotor 3 will start to rotate in the clockwise direction. Referring to Figs 10 and 11 , there is shown how the position angle of the blades 5 is changed in a high speed wind condition. Indeed, as the rotor 3 turns faster, the computer automatically controls the step motor so as to close the blades 5 around the rotor 3 and thereby diminish the contact surface between the relative wind and the rotating blades 5. The blades 5 change from a sail mode to an aerodynamic mode and consequently, the blades 5 are more powerful and produce more energy. By increasing excessively the position angle of the blades 5, the onboard computer produces an aerodynamic brake which stabilizes the rotor 3 and this allows to control its speed of rotation. In case of emergency or when maintaining the windmill, a disk brake may also be used for completely stopping the rotor 3.

It is to be noted that the adjustment means for adjusting the position angle of the blades 5 also controls the inertia of the rotor 3 as mass distributions are shifted depending on the position angle of the blades 5.

Another way to control the inertia of the rotor 3 is to use a separated shifting weight system. As shown in FIG 7, two weights 6 that are located at the base of the windmill 1 and are integrally connected to the central shaft of the rotor 3 can be shifted relative to one another so as to modify the inertia characteristics of the windmill 1. The onboard computer controls the separation of the two weights 6 mounted on lever-arms by means of a motor. The controlling of the lever-arms of these weights 6 creates a different torque around the central shaft of the rotor 3 so as to obtain a higher torque at a constant rotation speed of the rotor 3 when the lever-arms are lifted, therefore a higher windmill energy at constant speed.

Instead of using the weights 6, one could also use identical weights that may be mounted on the transversal rods 11 that are connected to the blades 5. In a similar way as described above, these weights may be moved by a step motor or an endless screw along the radial rods 11 and controlled by the computer to achieve the same results. WIND DEFLECTION SYSTEM AND POSITIONING OF THE SCREENS AND OF THE WIND VANE

Referring to FIGS 14 to 16, the windmill 1 may also have a wind deflection system 15 having deflectors 8 positioned peripherally with respect to the blades 5. The deflection system 15 is adapted to position itself automatically, pivotally and independently around the rotor 3 for redirecting the wind towards the blades 5 according to predetermined parameters. This may also be achieved by the above-referenced onboard computer and by means of a motor and the predetermined parameters may also include the above- mentioned ones.

Preferably, the wind deflection system 15 has a series of deflectors 8 that direct the wind towards the blades 5. The deflectors 8 are connected via transversal rods 10 to a stator that may move independently from the rotor 3. The deflection system 15 can close itself in case of violent wind for protecting the rotor 3. The beneficial effect of the deflection system 15 is that it redirects the wind towards blades 5 of the rotor 3 with the same angle, which maximizes the efficiency of the blades 5 and also reduces potential vibrations due to differences of forces applied on all the blades 5. The deflection system 15 also maximizes the quantity of air entering into the windmill 1 and impedes the wind from penetrating into the windmill if the wind speed is too high. Preferably, the deflection system 15 is oriented by means of a wind vane 45 which positions itself in the direction of the wind. The wind vane 45 is connected to a mechanical gear system 4 that automatically positions the deflection system 15. An electrical gear system can also be used instead of the mechanical gear system to achieve the same function.

ADDITIONAL PHOTO-ELECTRIC CELLS TO THE COVER OF THE WINDMILL TURBINE

Referring to Fig 1 , the windmill turbine may be provided with a cover 17 for protecting the windmill against adverse weather conditions. Of course, the windmill 1 may work perfectly well without this cover 17, but it is advantageous to use it. Indeed, the windmill 1 may also be provided with photoelectric cells that are mounted on the cover 17 for generating secondary electrical energy.

The cover 17 has several advantages that may distinguish it from the conventional windmills with horizontal axis which cannot be covered. Firstly, the cover 17 provides a certain rigidity to the structure of the windmill 1 so that it can operate in extreme wind conditions and/or wind gusts. Also, the cover 17 limits the exposure to the sun, to rain or to snow that may negatively affect or damage internal components of the windmill 1 , such as the central shaft, the rotor 3 and the blades 5. This cover 17 therefore allows to substantially prolong the useful life of the windmill turbine 1. Also, the cover 17 ensures an excellent physical support for the photoelectric cells which may directly face the sun. This photoelectric exposition ensures a secondary source of energy for different energy needs of the windmill 1 , such as electrical pumps, the onboard computer, communication networks, control systems, etc.

Given the relatively large size of the cover 17 versus the potential power of the windmill 1 , it is also possible to produce electricity by means of the photoelectric cells in parallel with the electric energy generated by the rotation of the blades 5. The secondary power source can be used to charge batteries or to heat water or for other commercial or residential applications.

SHAPE OF THE BLADES ACTING AS A SAIL OR AN AIRPLANE WING

The blades 5 may be similar in shape and have similar functions as airplane wings and also of sails. Indeed, the blades 5 function differently depending on the relative position of the blades 5 with respect to the wind. Preferably, the blade 5 as a shaped based on a S1223 airplane wing which may be adapted for a windmill. It is to be noted that a S1223 profile has excellent aerodynamic performances such as a high bearing pressure and a low drag in aerodynamic mode (when used at higher wind speeds such as in FIG 11). Its shape is also useful in sail mode (when used at lower wind speeds such as in FIG 9) because it produces a higher drag. Also, because the shape of the blade is not ultra thin, it makes it easier to introduce the above mentioned heat- conducting liquid system. USE OF COMPOSITE MATERIALS AND SPECIAL MATERIALS Preferably, windmill 1 is made from materials selected from the group consisting of: carbon fibers and reinforced glass fibers, aluminum 6061 -T6, steel W44, robust and waterproof silicone, copper, weaved carbon fibers and low consuming heating elements. About 45% of the structure of the windmill 1 may be made of aluminum 6061-T6 and about 25% is made of steel W44. The rest of the windmill 1 may be made of special materials that improve its overall performances.

SOFTWARE CONTROLLED WINDMILLS According to another aspect of the present invention, a plurality of windmill turbines 1 with onboard computers may be interconnected together to a master windmill turbine to allow an operator to have access to all the parameters of the windmills.

Accordingly, each of the windmill turbines 1 is provided with special high performance sensors such as MEMS (Micro Electro-Mechanical System) sensors that can allow the operator to control the windmills from a remote distance. These sensors can also allow the windmill to perform autonomous diagnostic procedures and to auto-calibrate themselves. An electronic system may also be used in order to access windmill parks via internet.

Each of the windmills may be provided with an onboard computer for performing its primary operations such as to control the position angle of the blades 5. The plurality of windmills 1 may be connected together via cable or wireless connections for the exchange of digital data. This configuration is similar to that of a computer network where data is exchanged and accessed to. A master windmill may be directly connected to an ISP (Internet Service Provider) either by high speed cable, by modem or satellite link. Satellite links are preferred when the windmills are located in hard to reach places.

From an operation post, the operator can then have access to all of the parameters of the windmills in order to take decisions without having to go on site. A digital camera system may also provide the operator with video images of the plurality of windmills in real time. Furthermore, the windmill can transmit data obtained through its sensors via internet or take its own decisions with the onboard computer. In case of a problem, the windmill transmits security codes to a central server that can then launch an alarm or decide what further steps should be taken. This results in an intelligent windmill that controls its operational parameters according to the readings of its sensors. For example, in case of an sudden increase in vibration in the central shaft of the windmill, it is possible to quantify the wear of joints and ball bearings.

Finally, because the windmill may be highly based on software and because of the fact that the windmill can be remotely reprogrammed, it can become completely reconfigurable. Therefore, it is possible to constantly improve the performances of the windmill by adjusting and/or improving the internal control software of the windmill, which also allows to remotely add on new functions. The SDE (Software Define Eole) is similar to SDR (Software Defined Radio) that are recently used in wireless telecommunications. One can thus recycle the concept of software definition of wireless radios and apply it to windmills.

FLEXIBILITY IN THE CHOICE AND COMPATIBILTY OF TRANSMISSIONS AND GENERATORS Preferably, the windmill turbines may be easily interfaced with any variable step or continuos transmission and also for an electric generator. At the bottom of the windmill, there is a spacing 30 (see FIG 1) that is sufficiently large to accommodate the installation and/or maintenance of a transmission. The windmill may be connected to TM4™ generators from Hydro-Quebec that have an efficiency higher than 97%. Of course, the windmill may be coupled various other types of electrical generators. It should be noted that some of these generators are completely efficient at 3000 RPM. Given that the rotation of the rotor 3 is of about 200 to 300 RPM, it is important to provide a fixed ratio transmission (1/10 for example) or a continuous step transmission. The windmill may be connected to very different ranges of transmissions and of generators. PRODUCTION AND STORING OF ENERGY

The windmills may include generators with permanent magnets that can achieve a very high efficiencies at variable speeds, and also higly efficient power electronics for producing electricity at different voltage ranges and frequencies in a continuos and reliable way. Thereby, the integration of the windmill to the electrical networks is facilitated. Preferably, the windmills produce electricity that is directly compatible with an existing electrical network.

A varialbe or constant step speed multiplier may be used to adapt the windmill to the rotation speed of the generators.

The generators powered by the windmill can activate hydraulic pumps of medium and high pressure. Also, energy may be easily accumulated in hydraulic accumulators or rechargeable batteries. Another possibility is to produce hydrogen for a fuel cell or for direct use in combustion or heating.

Lastly, there is the possibility of producing electrical energy by means of the photoelectric cells mounted on the cover 17 of the windmill 1.

MODULAR STRUCTURE AND STACKING OF WINDMILL TURBINES Referring to FIG 19, the windmill turbines according to the present invention may be designed so as to be completely modular. This facilitates the transportation of the windmills and the assembly of the different models. The maintenance of the windmills is also simplified because of the ease of access to the different modules that are fixed on the ground and located at a reasonable height compared to horizontal axis windmills that are usually very tall.

The structure of the windmill turbine is exceptionally rigid that can be used in extreme cold conditions, high winds and gusts.

The windmills are designed such that they can be stacked one on top of another, which is not possible with horizontal axis windmills or known vertical axis windmills. The rigid structure can allow to stack up to 5 or 6 windmills depending on the materials that are used in the manufacture of the structure of the windmill. The stacking of windmills is advantageous because it allows to obtain more energy for a give area. The windmill according to the present invention may be placed on a high pole but its performance is also excellent close to the ground.

STAGGERED AND INCLINED DOUBLE BLADES i

Referring to FIG 20, the windmill 1 may also have blades 5 that are inclined with respect to the vertical axis at about 70 degrees. Also, the blades may be provided with pairs of slightly staggered blades 5. This configuration is especially useful in larger sized windmills to increase the performances of the windmill.

PREFERENTIAL ADVANTAGES OF THE WINDMILLS Preferably, the windmills according to the present invention include some or all of the following non-restrictive advantages: - Production of electricity at relatively low speed.

- Production range of electricity adapted to average wind speed.

- Light weight and use in cold temperatures.

- Autonomous operation.

- Almost constant torque on the main shaft. - Automatic positioning of the blades in high speeds.

- Fail safe braking mechanism.

- Easy installation without requiring specialized personnel.

- Portable and easy maintenance.

- Low noise because of low speed of the main shaft. - Range of power generation is broad: from about 500 W to hundreds of kW.

Although preferred embodiments of the present invention have been described in detail herein and illustrated in the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments and that various changes and modifications may be effected therein without departing from the scope or spirit of the present invention.

Claims

CLAIMS:

1. A windmill turbine (1) with a central vertical axis comprising: a rotor (3); a series of blades (5) operationally connected to the rotor (3) for receiving wind and allowing a rotation of the rotor (3), the blades (5) being provided with internal heat-conducting channels (7) distributed within the blades (5) for receiving a heat-conducting liquid; and an electrical generator operationally connected to the rotor (3) for generating electricity, the generator having a liquid cooling system connected to the internal heat-conducting channels (7), the cooling system receiving the heat-conducting liquid having run through the internal heat-conducting channels (7), so that in operation, the heat-conducting liquid heats the blades (5) and cools down before returning to the cooling system of the generator.

2. The windmill turbine (1) according to claim 1 , further comprising a secondary electrical defrosting system having a metallic filament (9) integrated in each of the blades (5).

3. The windmill turbine (1) according to claim 1, wherein the blades are operationally connected to the rotor (3) via transversal rods (11) pivotally attached to the blades (5), each of the blades (5) having a rotational peripheral vertical axis that is parallel and equidistant to the vertical axis of the windmill turbine.

4. The windmill turbine (1) according to claim 3, wherein each blade (5) is connected to the rotor (3) via a liquid channel located within the rotor (3), each blade (5) having an upper opening for allowing an entry of the heat-conducting liquid from the liquid channel and a lower opening for allowing an exit of the heat-conducting liquid into the liquid channel, and a closed-circuit pump system for pumping the heat conducting liquid into the internal channels (7) of each blade (5) and into the cooling system of the generator.

5. A windmill (1) comprising: a rotor (3); and a series of blades (5) operationally connected to the rotor (3) for receiving wind and allowing a rotation of the rotor (3), the blades (5) having an inner surface and an outer surface, the outer surface being provided with riblets (13) for reducing a drag coefficient of the blades (5) and turbulence generated when the rotor (3) is rotating.

6. Windmill (1) according to claim 5, wherein the riblets (13) are V-shaped.

7. A windmill turbine (1) with a central vertical axis comprising: a rotor (3); a series of blades (5) operationally connected to the rotor (3) for receiving wind and allowing a rotation of the rotor (3), the blades (5) being connected to the rotor (3) via transversal rods (11) pivotally attached to upper and lower edges of each blade (5) for holding each blade (5) on a peripheral vertical axis that is equidistant to the vertical axis of the windmill; and blade adjusting means for controlling a position angle of each of the blades (5), the adjusting means having radial rods (41) respectively and pivotally connected to each blade (5) and to a control plate (12) mounted on the rotor (3), the control plate (12) being activated by a motor controlled by a computer so as to move each radial rod (41) with respect to each transversal rod (11) for automatically adjusting the position angle of the blades (5) according to predetermined parameters.

8. The windmill turbine according to claim 7, further comprising means for adjusting inertia of the blades (5), means for adjusting inertia of the blades (5) having a system of two opposite weights (6) that are moved one with respect to the other by means of a motor controlled by a computer for automatically adjusting the inertia of the blades (5) according to predetermined parameters.

9. The windmill turbine (1) according to claim 7, further comprising: a wind deflection system (15) having deflectors blades (8) positioned in periphery with respect to the blades (5) of the windmill (1), the deflection system (15) being automatically and pivotally and independently positioned around the rotor (3) for redirecting the wind towards the blades (5) according to predetermined parameters.

10. The windmill turbine (1) according to claim 9, comprising a wind vane (45) mounted on the windmill (1) for automatically positioning the wind deflecting system (15).

11. The windmill turbine (1) according to claim 9, comprising an electrical system with mechanical gears for automatically positioning a wind deflecting system (15). ₍

12. The windmill turbine according to claim 7, further comprising: a cover (17) for protecting the windmill; and an electrical generator connected to a rotor (3) for generating electricity and photoelectric cells on the cover (17) for generating secondary electric energy source.

13. The wind turbine according to claim 7, wherein each turbine has a modified S1223 wing shape.

14. The windmill (1) according to claim 7, wherein the windmill is made from materials selected from the group consisting of: carbon fibers and reinforced glass fibers, aluminum 6061 -T6, steel W44, robust and waterproof silicone, and copper.

15. The windmill (1) according to claim 7, wherein the blades (5) have an inner surface and an outer surface, the outer surface being provided with riblets (13) for reducing a drag coefficient of the blades (5) and turbulence generated when the rotor (3) is rotating.

16. The windmill (1) according to claim 7, wherein the blades (5) are provided with internal heat-conducting channels (7) distributed within the blades (5) for receiving a heat-conducting liquid; and the windmill further comprises an electrical generator operationally connected to the rotor (3) for generating electricity, the generator having a liquid cooling system connected to the internal heat-conducting channels (7), the cooling system receiving the heat-conducting liquid having run through the internal heat-conducting channels (7), so that in operation, the heat-conducting liquid heats the blades (5) and cools down before returning to the cooling system of the generator.

17. The windmill turbine (1) according to claim 16, further comprising a secondary electrical defrosting system having a metallic filament (9) integrated in each of the blades (5).

18. The windmill turbine (1) according to claim 7, further comprising a modular frame that is adapted to be stacked on top of another modular frame of a windmill turbine (1 ).

19. The windmill turbine (1) according to claim 7, wherein the blades (5) are inclined with respect to the vertical axis, and pairs of blades (5) are staggered with respect to each other.

20. The windmill turbine (1) according to claim 7, wherein the computer of the windmill turbine (1) is linked to a master computer of another windmill turbine (1), the master computer of said another windmill turbine being connected to a plurality of computers mounted on respective windmills turbines (1) for allowing an operator to access data obtained from sensors located on each windmill (1) and to control each of the windmills (1) via software commands.