Vertical axis wind turbine and power plant

Description

[0001] The present invention relates to the technical field of wind turbines and more particularly to vertical axis wind turbines, as well as power plants.

[0002] In the field mentioned above, it is well known that the natural movement of fluids such as wind or water can be transformed into clean domestic energy using a wind turbine. A domestic wind turbine, for example, converts the free energy of the wind into electricity. An inverter then transforms the direct current (DC) produced into alternating current (AC) for feeding into the grid or for on-site consumption.

[0003] Wind turbines consist of a generator, which is the unit that transforms rotating physical energy into electrical energy, and a turbine, which uses the energy produced by the movement of the fluid to drive the generator. The turbine-generator combination transforms the energy produced by the movement of the harnessed fluid into usable electrical energy.

[0004] Different types of wind turbines exist. The horizontal swashplate wind turbine is the most common type. This turbine captures the wind using blades assembled in a propeller shape, which rotate around a horizontal mast. With this type of turbine, the force of the rotating blades drives a generator located at the top of the turbine. The disadvantages of this type of turbine are, firstly, the noise it generates and, secondly, the complexity of installation depending on the height of the mast and its low efficiency.

[0005] It is also known as a vertical axis wind turbine. Unlike a horizontal axis wind turbine, a vertical axis wind turbine rotates around a vertically positioned tower. Such turbines are designed with a set of blades that share the same curvature about the vertical axis to capture the fluid. However, the fluid typically flows in one direction, and thus more than half of the surface area exposed to the fluid works against the direction of blade rotation. Examples of vertical axis wind turbines from the prior art are shown in publications KR 2012 0115612 A and US 1 708 374 A.

[0006] The main drawback of this type of wind turbine is the need for relatively strong winds to begin rotating and therefore producing energy. Furthermore, conventional vertical-axis wind turbines have a very low efficiency.

[0007] The invention aims to overcome these drawbacks by proposing a vertical axis wind turbine capable of capturing slow-moving fluids, thus producing energy even at very low speeds, and exhibiting a higher efficiency than horizontal axis wind turbines.

[0008] To this end, the invention relates to a vertical-axis wind turbine according to claim 1, comprising a generator having a central axis of rotation defining the vertical axis capable of driving in its rotary motion a set of magnets on a set of coils, a turbine capable of driving the generator, said turbine having the form of a first ring comprising a set of movable radial blades extending from the generator, and a peripheral element having the form of a second ring surrounding the first ring comprising a set of fixed radial blades extending from the turbine. The turbine and generator combination transforms the energy produced by the movement of a controlled fluid into usable electrical energy.

[0009] According to the invention, the movable blades are arranged radially with a curvature angle opposite to the fixed radial blades, which are also arranged radially. The wind turbine's efficiency is related to the active surface area exposed to the fluid. The implementation of two sets of radial blades working together allows for improved fluid capture efficiency.

[0010] According to the invention, the angle of curvature of the movable radial blades is progressive. The entire exposed surface is thus optimized to be active.

[0011] Advantageously, the wind turbine according to the invention, due to its concentric ring shape, has a low center of gravity and a wide base. Thus, not requiring a pylon, it is very easy to install a wind turbine according to the invention on a roof.

[0012] Advantageously, the turbine and the peripheral are located away from the central axis of rotation.

[0013] Conventional wind turbines have their aerial area defined by the rated power of their generator when the turbine is exposed to the maximum permissible wind speed before feathering. This maximum speed is generally 90 km / h. Due to the low rotational speed of the wind turbine according to the invention when it reaches its rated power, the turbine's ground stability, and the virtually unlimited achievable solar collector area, it is possible to oversize the aerial area for the same rated power value so that the generator's rated power is obtained at the average wind speed of the installation area, i.e., 30 km / h. Thanks to its regulation system, the wind turbine will continuously deliver its rated power up to wind speeds of approximately 200 km / h.

[0014] Wind turbines thus considerably limit the intermittency of their production while significantly increasing the number of kilowatts produced in a year.

[0015] According to the invention, the respective diameters of the wind turbine's moving blades, rotor magnets, and generator stator coils are brought closer together. This allows the generator to be driven at a speed sufficient to reach at least the required load voltage without needing to increase the turbine's rotational speed with an energy-intensive system. The relationship between the speed of the air mass entering the turbine and the generator's rotational speed is optimized.

[0016] According to one embodiment of the invention, the generator is inserted into the wind turbine's rotor. Advantageously, the torque obtained by the generator's lever arm, located away from the turbine's axis of rotation, is thus optimal at low rotational speeds and without causing any disturbance. This characteristic holds true whether there is one or more generators, depending on the chosen homothety described below.

[0017] The wind turbine according to the invention is designed to be installed on a roof or a flat surface. Since the generator is incorporated into the turbine, the entire windward surface is thus active. Unlike existing wind turbines that capture wind at a 40° angle, the combined shape of the fixed and moving blades allows the turbine to capture air at a 180° angle.

[0018] According to the invention, the movable blades are arranged radially with an angle of curvature opposite to the fixed radial blades also arranged radially.

[0019] According to the invention, the movable and fixed radial blades have the shape of a rectangular panel with a regular curved and hollow profile.

[0020] According to one feature of the invention, the movable radial blades have a more curved profile than the fixed radial blades.

[0021] According to one feature of the invention, the number of fixed radial blades is identical to the number of movable radial blades.

[0022] According to one embodiment of the invention, the wind turbine comprises twelve movable radial blades. This embodiment with twelve blades allows for efficient channeling of the airflow, thus preventing the wind from passing through the turbine without having extracted all of its power.

[0023] According to the invention, the end-to-end profiles of a fixed radial blade and a movable radial blade follow a mathematical curve. The convergence of the two airflows at the tips of the movable and fixed blades eliminates negative resultants and contributes to increasing the pressure pushing the blade through the centrifugal force exerted by the fluid molecules on the lower surface of the movable blades.

[0024] According to the invention, the end-to-end profiles of a fixed radial blade and a movable radial blade follow a continuous convex mathematical curve. This continuous curved shape allows for optimal efficiency in capturing the wind entering the wind turbine. The curvature angle of the radial blades is gradual and not constant to maintain the speed of the air mass thus guided. Furthermore, the continuity of this gradual curvature is maintained during the transition from a fixed radial blade to a movable radial blade with a deliberately reversed curvature angle.

[0025] According to the invention, the profile of the movable radial blades has a more pronounced progressive angle of curvature than the profile of the fixed radial blades. Thus, the plane of the fixed radial blade on the wind turbine's median axis is perfectly aligned with the wind direction, so as not to create any obstacle or negative effect on the forward flow of air captured by the turbine.

[0026] Furthermore, the endpoints of the radial blade profiles are aligned with the center of the wind turbine.

[0027] Consequently, the resultant force applied to the lower surface of the fixed radial blade gradually increases, becoming minimal along its entire length and reaching its maximum at the center of the lower surface of the rotating radial blade. The exponential nature of the increasing curvature angle of the radial blades concentrates the resultant forces applied to the lower surface of the radial blades at the point that contributes most effectively to the rotation of the wind turbine.

[0028] In other words, the fluid molecules are progressively accelerated by centrifugal force and exert increasing thrust on the lower surface of the blades to release all of their kinetic energy before being directed back towards their starting point. These molecules will then make a gradual 180° turn.

[0029] The implementation of such an architecture and arrangement of fixed and movable radial blades allows for the progressive deflection of the air mass moving along a linear axis, causing it to adopt a circular trajectory. Advantageously, this makes it possible to recover all of the kinetic energy of the air mass entering the wind turbine. Thus, the energy collection from the turbine's intake surface is optimized. According to another feature of the invention, the spacing between two successive blades corresponds to the distance obtained at the highest point of said curve.

[0030] To counteract the Venturi effect, vents are incorporated into the turbine's upper plate. The plate supporting the tops of the rotating radial blades is perforated in its center to facilitate the escape of compressed air flows at the turbine's core. Air entering the turbine naturally escapes through the gap between the blades after they have completed three-quarters of a turn. However, its evacuation is impeded by the contours of the radial blades opposite the inlet axis. This results in an increase in pressure at the turbine's center. Therefore, extraction scoops are attached to the upper plate. The expelled air escapes either through the gap between the cover and the rotating plate or through perforations in the cover.

[0031] According to one embodiment of the invention, the movable and fixed radial blades have the same length and substantially the same height.

[0032] In one embodiment, the wind turbine further includes an extension forming a structure around the perimeter and comprising additional fixed blades in line with each of the fixed radial blades. Adding an extension to the assembly increases the fluid flow collection area. The extensions are individually designed to optimize the fluid movements at each location.

[0033] The invention also relates to a power plant according to claim 7 comprising an assembly of fixed and movable radial blades mounted on a circular turbine rail, said rail running on a track of wheels, each equipped with a generator. Such a power plant is based on the same principle as a wind turbine according to the invention, but with larger dimensions and a greater number of offset generators. A power plant according to the invention can advantageously be located surrounding an area that requires an electrical power supply.

[0034] The power plant according to the invention is a homothety of the claimed wind turbine.

[0035] The wind turbine according to the invention comprises movable radial blades that drive one or more generators arranged horizontally or vertically. The drive is achieved in a known manner, by means of a toothed ring bolted to the generator and a toothed circular rail attached to the lower part of the turbine. This arrangement notably allows for the series connection of the generators to optimize the tracking of the inverters.

[0036] To counter the Venturi effect, the power plant is open-air.

[0037] Of course, the different features, variants and embodiments of the invention can be combined with each other in various ways as long as they are not incompatible or mutually exclusive.

[0038] Furthermore, various other features of the invention become apparent from the attached description made with reference to the drawings which illustrate non-limiting embodiments of the invention and where: [ Fig.1 ] is a perspective view of a wind turbine according to the invention, [ Fig.2 ] is a transparent perspective view of the wind turbine of the figure 1 , [ Fig.3 ] is a view of a detail of the wind turbine and in particular the generator of the figure 1 , [ Fig.4 ] is a cross-sectional view of the wind turbine of the figure 1 presenting a cross-sectional plane DD', [ Fig.5 ] is a view of the section along DD', [ Fig.6 ] is a perspective view of an example embodiment of a movable blade according to the invention, [ Fig.7 ] is a perspective view of an example embodiment of a fixed blade according to the invention, [ Fig.8 ] is a schematic view of the curve enabling the obtaining of examples of blades according to the invention, [ Fig.9 ] is a partial schematic view of the operation of a wind turbine according to the invention, [ Fig.10A ] is a schematic view of an example of a wind turbine design including an extension, [ Fig.10B ] is a schematic view of another example of a wind turbine design including an extension, [ Fig.10C ] is a schematic view of another example of a wind turbine design including an extension, [ Fig.11 ] is a transparent perspective view of an example embodiment of a power plant according to the invention, [ Fig.12 ] is a perspective view of a detail of the power plant of the figure 11 , And [ Fig.13 ] is a schematic view of different generator arrangements for a power plant according to the invention.

[0039] It should be noted that in these figures the structural and / or functional elements common to the different variants may have the same references.

[0040] The invention aims to increase the efficiency of a vertical axis wind turbine. To this end, the invention proposes the implementation of two sets of radial blades, one movable and one fixed, whose angles of curvature work together to increase the efficiency of the wind turbine.

[0041] The wind turbine according to the invention is compatible with a fluid such as air but also with water in the case where the wind turbine is immersed.

[0042] A vertical axis wind turbine according to the invention, as illustrated in figures 1 And 2 and designated as a whole by reference 1 comprises a generator 2 capable of driving in its rotary motion a set of magnets 3 (rotor) on a set of coils 4 (stator) and a turbine 5 capable of driving the generator 2 around a vertical axis V defining a bottom and a top.

[0043] There figure 3 illustrates an example of a generator 2 comprising twenty-four movable magnets 3 arranged on a support 4. According to other embodiments, a larger number of movable magnets 3 can be fixed to the generator 2.

[0044] Visible to figures 1 And 2 , a turbine 5 forms a first ring around the generator 2. The turbine 5 comprises a set of movable radial blades 6 arranged radially around the generator 2. The movable radial blades 6 are contained within a casing forming a hollow cylinder closed at both ends.

[0045] The movable radial blades 6 are vertically elongated, with their lower end fixed to a support for the turbine 5. The turbine 5 is a moving monobloc that drives the generator 2.

[0046] Also visible to figure 1 And 2, a peripheral 7 forming a second ring around the first which includes a set of fixed radial blades 8 arranged radially with respect to the generatrix 2. The fixed radial blades 8 are contained within a casing forming a hollow cylinder.

[0047] The fixed radial blades 8 are also vertically elongated, with one lower end fixed to a lower fixed ring of the peripheral structure 7 and the upper end fixed to a high disc of the peripheral structure 7 which advantageously protects the wind turbine 1. The peripheral 7 is a fixed monobloc of the wind turbine 1.

[0048] According to the illustrated embodiment, the radial blades 6, 8 are all evenly spaced. This ensures regularity in the rotation of the turbine 5.

[0049] The fixed radial blades 8 and movable 6 are of different heights, in particular to provide space under the movable radial blades 6 for the assembly of the wind turbine 1.

[0050] According to the illustrated embodiment, the wind turbine 1 comprises twelve fixed blades 8 and twelve movable blades 6. Depending on the power required and therefore depending on the choice of the sizing of the generator 2, the wind turbine 1 comprises a higher number of fixed radial blades 8 and movable radial blades 6, the number of fixed radial blades 8 and movable radial blades 6 remaining the same.

[0051] There figure 4 presents a cross-section along axis DD' of wind turbine 1 at the level of generator 2. This cross-section along DD' is presented at the figure 5 . Nine fixed coils 4 are thus located in the centre of the generator 2 of the wind turbine 1 and are surrounded by the turbine 5 and then the peripheral 7.

[0052] The larger the diameter of turbine 5, the slower it rotates. The wind flow circulating over the central perimeter of generator 2 maintains its own speed. The number of revolutions per minute (RPM) obtained for a given wind speed must correspond to the RPM of generator 2 for a desired power output in watts per hour. Braking generator 2 under load will prevent it from overspeeding and will maintain a comfortable rotational speed.

[0053] The chosen diameter of turbine 5 maintains sufficient leverage. The aim is to coordinate the range of average wind speeds, the rotational speed of turbine 5, and the rotational speed of generator 2 to achieve a linear progression of the power output of generator 2 as wind speed increases.

[0054] Each movable radial blade 6 of the turbine 5 uses the pressure on the inner wall of its profile to move forward. The airflow intended for each movable radial blade 6 is concentrated and directed to the precise optimal location without pressure loss.

[0055] The movable radial blades 6 and the fixed radial blades 8 are illustrated respectively in figures 6 And 7 According to these examples, the radial blades 6 and 8 have a rectangular shape with a curved profile. These two profiles were chosen to maximize the capture of wind or fluid driving the wind turbine 1.

[0056] The 8 fixed radial blades have a hollow profile. This hollow profile is a slow and powerful suction profile.

[0057] There figure 8 This illustrates a mathematical curve on which the profile of the fixed radial blades 8 and movable radial blades 6 is based. This curve is contained within a section with an angle α approximately equal to 47.5°. The radial blades 6 and 8 are designed by dividing this mathematical shape into two parts; the more deeply concave part forms a movable radial blade 6, and the part with less curvature forms a fixed radial blade 8.

[0058] The two directions of curvature of each of the radial blades 6,8 are then reversed in order to promote the capture of the fluid as seen in the cross-section figures of the example of the realization of the wind turbine 1.

[0059] The arc of a movable blade 6 is the same length as the arc of a fixed blade 8.

[0060] Tests have been carried out to demonstrate the effectiveness of this particular shape which allows the design of the two types of radial blades 6,8 described above.

[0061] This particular mathematical form illustrated in the figure 8 also allows defining the optimized space E between two radial blades 6,8. Preferably, the spacing E between each movable radial blade 6 is substantially the same on the turbine 5.

[0062] Wind turbine 1 comprises a lower and upper support. The fairing created by the upper and lower supports plays an important role in preventing air from escaping vertically. The space E between two fixed radial blades 8 of the peripheral 7 and the lower and upper supports of wind turbine 1 forms a box that concentrates the airflow precisely in the trough of the movable radial blades 6.

[0063] There figure 9 This diagram schematically represents the movement of wind turbine 1. The solid arrows represent the wind (this could also correspond to other fluids). The direction of movement of the movable radial blades 6 is indicated by the dashed arrow. Advantageously, the entire surface of wind turbine 1 exposed to the wind is active and captures all the energy from even the slightest breeze, thus increasing the efficiency of wind turbine 1.

[0064] According to one embodiment of the invention, the wind turbine 1 further comprises an extension 10. This extension 10 is a continuation of the peripheral 8. The figures 10A, 10B And 10Cillustrate alternative embodiments of an extension 10 according to the invention. Other embodiments are also possible, the extension 10 allowing for better fluid capture. To achieve this, the extension 10 comprises additional blades 11 which are a straight extension of the fixed radial blades 8. The additional blades 11 therefore have the shape of a flat panel of the same height as the fixed radial blades 8.

[0065] The rotation of the movable radial blades 6 induces the rotation of the generator 2, which drives the magnets 3. This movement near the coils 4 creates an electric current. According to the illustrated embodiment, the twenty-four movable magnets 3 and the twelve fixed coils 4 convert the rotary motion of the turbine 5 into electrical energy. The current produced is three-phase alternating current. This current is converted into direct current by a regulator (not shown). The direct current is then converted back into alternating current by an inverter (not shown) for direct consumption or for sale to the grid. This embodiment is not limiting to the invention.

[0066] A generator 2 compatible with the invention comprises permanent magnets and operates by means of the induction produced in a winding 4 passing between at least two magnets 3. The generator 2 therefore does not require brushes. This is the same principle as a "brushless motor". Depending on the relative number of windings and magnets, the alternating current produced by the generator 2 can be either three-phase or single-phase.

[0067] A domestic wind turbine 1 according to the invention produces 3 to 5 Kilowatts per day placed flat or on a ridge on a roof or on a short pylon in a garden.

[0068] The operating system of a power plant 20 according to the invention is the same as the operating system of a wind turbine 1. It is a homothety in particular of the dimensions of a wind turbine 1.

[0069] In a power plant 20, the number of generators 2 increases, and these generators 2 are offset from the center of the previously described wind turbine system. This notably frees up the central space in power plant 20.

[0070] Thus, the invention is also applied to large dimensions, allowing for the multiplication of generators 2, which are then driven by an oversized turbine 5. The movable blades 6 of the generator 2 are then connected to a circular rail of the turbine 5. The generators 2 constitute a fixed circular track positioned under the rail of the movable blades 6.

[0071] The driving of the generators 2 by the movable blades 6 is done asynchronously regardless of the arrangement of the generators 2 with respect to the rail.

[0072] Advantageously, by increasing the number of blades, one moves from an arrangement of movable blades 6 and fixed blades 8 on two plates as described for wind turbine 1 to an arrangement of movable blades 6 and fixed blades 8 on two rings as they are visible in the figure 11 The central space is thus freed up.

[0073] According to the example illustrated in the figure 11 , the power plant 20 includes 120 movable blades 6 mounted on a turbine rail 5 and 120 fixed blades 8.

[0074] A power plant 20 includes the same profile of moving blades 6 and fixed blades 8 as a wind turbine 1.

[0075] The fixed blades 8 and mobile blades 6 are of different heights in order in particular to provide a track for the central unit 20.

[0076] As illustrated in the figure 12 The movable blades 6 located on the turbine 5 prevent the airflow from escaping. And, the airflow is channeled on all sides by the fixed blades 8 (not shown).

[0077] The power plant 20 can also include an extension 10. The fixed radial blades 8 are thus of two types, namely, fixed profiled blades which progressively transform linear airflows into rotating airflows and additional blades 11 (which have a substantially flat shape) which will increase the air capture surface in harmony with the movements of the terrain and the plane on which the wind turbine 1 is positioned. For example at the top of a roof or a hill, the extension 10 will have the shape of a half diabolo to block the slope flows.

[0078] For a power plant 20, the position of the generators 2 relative to the turbine 5 differs. The number and position of the generators 2 are variable to allow for horizontal homothety. The figure 13illustrates the possibilities of arrangement of generators 2 in relation to turbine 5. Indeed, various arrangement architectures of generators 2 on turbines 5 are possible for a power plant 20 according to the invention.

[0079] Of course, various other modifications can be made to the invention within the scope of the attached claims.

Claims

1. Wind turbine (1) having a vertical axis, comprising: - a generator (2) having a central rotational axis defining the vertical axis (V), which generator is capable of driving, in its rotary movement, an assembly of magnets (3) on an assembly of coils (4), - a turbine (5) capable of driving the generator (2), said turbine (5) being in the shape of a first ring around the generator (2) and comprising an assembly of movable radial blades (6) extending from the generator (2), - a periphery (7) in the shape of a second ring surrounding the first ring, and comprising an assembly of fixed radial blades (8) extending from the turbine (5), in which vertical-axis wind turbine the movable radial blades (6) are arranged radially at an angle of curvature, opposite the fixed radial blades (8) which are also arranged radially, the movable radial blades (6) and fixed radial blades (8) are in the shape of a rectangular panel having a regular curved and hollow profile, and the profiles of a fixed radial blade (8) and a movable radial blade (6), which profiles have been placed end-to-end, follow a continuous convex mathematical curve, the profile of the movable radial blades (6) having a greater progressive angle of curvature than the profile of the fixed radial blades (8) having an inverted angle of curvature.

2. Wind turbine (1) according to the preceding claim, wherein the number of fixed radial blades (8) is identical to the number of movable radial blades (6).

3. Wind turbine (1) according to either of the preceding claims, comprising twelve movable radial blades (6).

4. Wind turbine (1) according to any of the preceding claims, wherein the spacing between two successive radial blades (6,8) corresponds to the distance obtained for the highest point of said curve.

5. Wind turbine (1) according to any of the preceding claims, wherein the movable radial blades (6) and fixed radial blades (8) are the same length and substantially the same height.

6. Wind turbine (1) according to any of the preceding claims, further comprising an extension (10) forming a structure around the periphery (7) and comprising additional fixed blades (11) in continuity with each of the fixed radial blades (8).

7. Power plant (20) comprising an assembly of fixed radial blades (8) and movable radial blades (6) mounted on a rail of a circular turbine (5), said rail traveling on a track of wheels, each wheel provided with a generator (2), the movable radial blades (6) and fixed radial blades (8) are in the shape of a rectangular panel having a regular curved and hollow profile, and the profiles of a fixed radial blade (8) and a movable radial blade (6), which profiles have been placed end-to-end, follow a continuous convex mathematical curve, the profile of the movable radial blades (6) having a greater progressive angle of curvature than the profile of the fixed radial blades (8).