CA2582176A1

CA2582176A1 - Wind turbine

Info

Publication number: CA2582176A1
Application number: CA002582176A
Authority: CA
Inventors: Armand Robitaille; Patrice Austin; Jean-Pierre Binda; Nicolas Marcotte
Original assignee: Turbines Eoliennes Vertica Inc.; Armand Robitaille; Patrice Austin; Jean-Pierre Binda; Nicolas Marcotte; Turbines Eoliennes Esta Inc.
Current assignee: TURBINES EOLIENNES VERTICA Inc
Priority date: 2007-03-19
Filing date: 2007-03-19
Publication date: 2008-09-19
Also published as: KR20100015692A; BRPI0808223A2; EP2134964A4; MX2009010075A; EP2134964A1; WO2008113169B1; WO2008113169A1

Abstract

The present invention provides a wind turbine having an increased efficiency.
The top portion or roof of the wind turbine has an opening and the profile of the top portion induces a downward component to the velocity of the wind, causing it to enter into the opening and increasing the wind intake. A wind deflector device may be added above the wind turbine to force more wind to enter into the opening.

Description

File number: 11174-004 Revision: as filed Date: 2007-03-19 Title of the Invention [0001] Wind turbine rotor Cross-Reference to Related Applications [0002] There is no cross-reference to related applications.
Field of the Invention [0003] The present invention relates generally to wind turbines and more particularly to a rotor for use therein.

Background of the Invention [0004] The goal of a wind turbine system is to convert the kinetic energy of wind to drive a generator, resulting in the conversion of the wind force to electrical energy, or a mechanical device such as a pump, directly. Many attempts have been made in the past to improve the efficiency of vertical axis wind turbine. But in all cases a substantial construction cost and maintenance cost is implied because the installations are very large or they need very complex systems. As seen in US Patent no. 4,052,134 (Rumsey), each blade is pivotally carried on the body supporting the plurality of blades, with a control means to maintain a substantially constant blade angle of attack to a relative wind vector.
Thus the orientation of the blades is constantly moving. This implies a control means at each blade and a lot of precision parts. In this invention, to lighten the weight of the wind turbine structure, the top portion is annular.

[0005] In other inventions using an opening above the blades, the goal is to lighten the structure as for the previous US Patent no. 4,052,134 or to create an air outlet as in US
Patents no. 4,036,916 (Agsten), no. 4,070,131 (Yen) and no. 6,717,285 (Ferraro).

File number: 11174-004 Revision: as filed Date: 2007-03-19 [0006] Others have developed vertical axis turbine wind turbines that are provided with a top without any opening such as shown in US Patents no. 5,020,967 (Gual) and 6,309,172 (Gual).

File number: 11174-004 Revision: as filed Date: 2007-03-19 Objects of the Invention [0007] A first object of the present invention is to improve the efficiency of a wind turbine.

[0008] Another object of the present invention is to provide a wind intake on the top portion of a vertical axis wind turbine to increase the total air volume available inside the turbine.

[0009] An additional object of the present invention is to increase the air volume passing through the wind intake of the top portion.

[0010] A further object of the present invention is to increase the total air volume available inside the wind turbine.

[0011] Another object of the present invention is to provide a wind deflector device to force more wind to pass through the top wind intake.

[0012] Other and further objects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.

Summary of the Invention [0013] The present invention provides a wind turbine of the type having a top portion and base to hold the blades, wherein the wind turbine comprises an opening in the top portion, the top portion having a cross-sectional profile that induces a downward component to the path of the wind, causing it to enter into the opening. A wind deflector device may also be provided to deviate wind into said opening.

File number: 11174-004 Revision: as filed Date: 2007-03-19 [0014] The principal goal of the present invention is to increase the power/efficiency of a "vertical axis" type wind turbine. The inventors have discovered that by allowing and preferably inducing additional wind intake by the top portion of a wind turbine rotor, which is a novel approach, the power of the wind turbine is significantly increased without significantly increasing the overall size of the rotor. In fact, when the wind enters the wind turbine rotor by an opening in the top portion of a turbine rotor, it goes directly on the opposite blades inside the wind turbine rotor and may increase the efficiency coefficient by up to 50% or more. Furthermore, this improvement is obtained while neither the size of the wind turbine rotor nor of the blades has been significantly increased. In the prior art, when an opening in the top portion of a wind turbine was used to lighten the structure of the wind turbine rotor or as an air outlet. The opening in the top portion may increase the wind volume entering in the wind turbine from 10% to 15%
compared to a wind turbine without such an opening in the top portion. It is to be noted that the top portion or roof of the present invention may be used on most "squirrel cage"
type wind turbines, whether vertical or horizontal. The present invention is described for a wind turbine rotor having a plurality of blades disposed between two circular plates, a top plate and a base plate. The blades are preferably located at the circumference of the plates.

[0015] Usually, for calculation and simplification purposes it is assumed that the wind flows parallel to the ground. A portion of the wind goes through the blades and the other portion continues above and on the sides of the wind turbine. The present invention provides an increase in the power or "utilisation factor" of a wind turbine without changing the projected surface that faces the wind. This is achieved by inducing and forcing the wind to also enter into the wind turbine rotor through an opening in its top portion and not only between the blades of the rotor.

[0016] The top portion of the wind turbine rotor is designed to induce a downward perpendicular component w to the path V. of the wind which is substantially parallel to the surface on which the turbine is installed. In the case of a horizontal wind turbine or for a turbine which is installed on an inclined surface, it is to be understood that the term File number: 11174-004 Revision: as filed Date: 2007-03-19 downward component must be understood as a component causing the wind to enter in the opening. With the downward perpendicular component, the wind enters into the opening and hits the blades from the inside and this is completely counter intuitive. In the preferred embodiment, the profile of the top portion has a rounded outer perimeter or edge followed by a slope going down towards the center of the opening while the inner perimeter has a sharp edge. This design which is similar to the cross-section of a plane wing causes a similar effect on the wind as in the case of a plane wing, where an uplifting vertical component is generated in the wind after it has passed the leading edge of the plane wing. Furthermore, if the internal edge of the profile of the top portion is deflected towards the center of the opening, a ventury effect may be created. In the present document, the tenm leading edge refers to the round outer edge of the profile of the top portion while the term trailing edge refers to the sharp inner edge of the profile. Similarly, in this document, all references to "top' and "bottom" assume that the wind turbine is installed such that the base is lower than the "top" portion. However, the reverse is also possible although not preferred. In such a case, the references to the "top"
portion will in reality be to what will then be the bottom portion.

[0017] The top portion may be divided in a plurality of segments. The global profile is similar to the profile presented above, but there is at least one space provided between the parts wherein the wind enters in the wind turbine. Also, the top portion may be constituted by superposed (at least partially) segments, where at least one segment induces a downward component to the path of the wind. In the latter case, the wind is forced to follow the direction induced by the superposed segments.

[0018] Another way to increase the wind intake is by forcing the wind to enter into the opening of the top portion with a wind deflector device. The wind deflector device may be attached over the top portion to force more wind to enter into the opening.
It captures a portion of the wind that would not normally flow over the wind turbine without entering into the opening. The wind deflector device may rotate with the wind turbine rotor or not.
The wind deflector device may have a plurality of shapes but the common characteristic File number 11174-004 Revision: as filed Date: 2007-03-19 is a curved profile (when viewed from the side) that capt the wind and redirects it into the opening.

[0019] The wind deflector device and the aerodynamic profile for the top portion may be used together or independently but the combination provides better results.

[0020] The features of the present invention which are believed to be novel are set forth with particularity in the appended claims.

Brief Description of the Drawings [00211 The above and other objects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:
[0022] Figure 1 is a cross-sectional side perspective view showing the top portion of a wind turbine rotor.

[0023] Figure 2a and 2b are a side view and a cross-section side view of a wind turbine rotor.

[0024] Figure 3a to 3d are cross-section side views of profiles of different multi-part top portions.

[0025] Figure 3e is a cross-section side view showing the path of the wind with a multi-part top portion.

[0026] Figure 4a is a cross-section perspective view showing a top portion composed by two superposed parts.

File number: 11174-004 Revision: as filed Date: 2007-03-19 [0027] Figure 4b is a cross-section side view showing the path of the wind with the top portion of Figure 4a.

[0028] Figure 5a, 5b and 5c are a top view and a side views of a wind deflector device.
[0029] Figure 6a to 6c are a top view and a side view showing the path of the wind with a wind deflector device.

Detailed Description of the Preferred Embodiment [0030] A novel wind turbine rotor and device to increase the wind intake will be described hereinafter. Although the invention is described in terms of specific illustrative embodiment(s), it is to be understood that the embodiment(s) described herein are by way of example only and that the scope of the invention is not intended to be limited thereby as stated earlier, the wind turbine rotor may be installed upside down without departing from the invention.

[0031] Figure 1 shows the top portion 105 of a first embodiment of a wind turbine rotor having an opening 130 and a cross section 140 to 145. The top portion 105 has a profile 110 which cause the wind to enter the opening 130. The path of the wind is shown by the lines 120. The leading edge 145 of the profile 110 is directed towards the exterior of the top portion 105 and the trailing edge 140 is directed towards the opening 130.
This configuration of the profile induces a downward component w to the path V. of the wind.
[0032] A second embodiment is shown in the Figures 2a and 2b, wherein the internal edge 240 of the top portion 205 leans towards the opening 230. The profile 210 has its rounded edge 240 is directed towards the opening 230 and its sharper edge 245 is directed towards the exterior of the top portion 205.

File number. 11174-004 Revision: as filed Date: 2007-03-19 [0033] Figure 3a to 3d show different embodiments for top portions having a profile constituted by a plurality of segments. It is to be noted that even if the top portions shown are constituted by two segments, it is possible to have more than two segments.

[0034] Figure 3e shows the path of the wind with a top portion constituted by two segments. As for the profile of Figure 1, the wind is forced to enter through the opening 330. The wind also enters through the space 370 between the segments 380 and 385 of the top portion, increasing again the wind intake.

[0035] Another embodiment is shown in Figure 4a, wherein the top portion 405 of the wind turbine rotor is constituted by two superposed segments, a first segment 410 and a second segment 415. Each of them have a profile that induces a downward component to the wind path, as shown in Figure 4b and causes the wind to enter into the opening 430.

[0036] Figures 5a and 5b show an embodiment for a wind deflector device, which has a curved profile 510 to capt and redirect the wind and forces it to enter into the opening of the top portion (not shown). The embodiment shown in Figure 5c has a general circular shape.

[0037] The schematic lines in Figure 6a to 6c show how the wind is redirected by the wind deflector device.

[0038] While illustrative and presently preferred embodiment(s) of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may be otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.

Claims

1. A wind turbine rotor of the type having a top portion and base between which blades are attached, said rotor comprising:
a. an opening in said top portion;
b. said top portion comprising means to induce a downward movement to said wind, causing it to enter into said opening.

2. The wind turbine rotor of claim 1, wherein said inducing means include an aerodynamic profile.

3. The wind turbine rotor of claim 2, wherein said aerodynamic profile is an airplane wing like profile.

4. The wind turbine rotor of claim 2, wherein said profile has a first edge which is rounded.

5. The wind turbine rotor of claim 4, wherein said profile has a second edge which is sharper than said first edge.

6. The wind turbine rotor of claim 5, wherein one of said edge slopes towards the center of said opening to create a ventury effect

7. The wind turbine rotor of claim 3, wherein said inducing means comprises a plurality of wing airplane like profiles spaced apart from each other.

8. The wind turbine rotor of claim 3, wherein said inducing means comprises a plurality of spaced segment which together form an airplane wing like profile.

9. The wind turbine rotor of claim 7, wherein wind is forced to go through said spaces.

10. The wind turbine rotor of claim 8, wherein wind is forced to go through said spaces.

11. The wind turbine rotor of claim 3, wherein said inducing means comprises a plurality of at least partially superposed airplane wing like profiles spaced apart from each other.

12. The wind turbine rotor of claim 11, wherein wind is forced to go through said spaces.

13. The wind turbine rotor of claim 1, wherein said inducing means comprises a wind deflector attached to said wind turbine over said opening, said wind deflector forcing wind to enter into said opening.

14. The wind turbine rotor of claim 13, wherein said wind deflector rotates with said wind turbine rotor.

15. The wind turbine rotor of claim 13, wherein said wind deflector device does not rotate with said wind turbine rotor.

16. A wind deflector for a wind turbine, said wind turbine rotor having a top portion having itself an opening, said wind deflector comprising a curved profile to deviate said wind into said opening.

17. The wind deflector of claim 16, wherein said wind deflector is attached over said opening.

18. The wind deflector of claim 16, wherein said wind deflector rotates with said wind turbine rotor.

19. The wind deflector of claim 16, wherein said wind deflector does not rotate with said wind turbine rotor.