ES2391741B2 - Vertical axis drag turbot with variable intake - Google Patents

Abstract

Vertical axis drag turbine with variable intake, which has a wind intake regulation housing and also eliminates the drag coefficient and force on the back of the blades, achieving a higher power coefficient in relation to those of its class and that allows it to operate in high speed regimes, and that in cases of extreme winds the intake can be completely closed to protect the wind rotor.

Description

Vertical axis drag turbot with variable intake

Field of the Invention

The invention is in the field of fluid mechanics, and more specifically of the machinery for the use of wind energy. The turbine is valid to cover the entire range of powers and will preferably be coupled to an electric generator to generate electricity.

10 Foundations of the invention

The invention relates to an air turbine with a vertical rotation axis that essentially has a wind rotor, preferably with eight-blade drag, which is arranged inside a chamber, and this is arranged on the upper end of a column support. The chamber has an air inlet opening and an outlet opening, preferably diagonally opposite. Said openings are adjustable and can be completely closed or can be regulated, that is, adjustable admission. The main purpose of the variable intake is that since the rotor 2 O is a wind drag, it is known that at high wind speeds, said rotors are packed. Disorientation systems are known in the art to avoid such a phenomenon, but that forces the turbine to become out of order. The invention recommends being able to operate at high wind speeds, closing the admission necessary and in case of extreme winds closing completely.

25 It requires an orientation system, which normally consists of a wind vane for small-sized turbines, and for large-sized turbines it consists of a motorized system.

One of the fundamental aspects of the turbine is focused on the operation of the

3 O wind rotor. The invention proposes a drive rotor preferably of eight blades, and with the same profile for the front and back of the blade, preferably flat and of light and economical material, since it will not have to be subjected to a wind speed greater than the Nominal design It is known in the state of the art that drag turbines require that the front and back have a different shape, for

35 concave and convex example, so that they have different drag coefficients, CD, on the front and back of the blades, giving rise to different drag forces, FD, and therefore at an effective turning moment that will produce a rotational movement in the wind rotor, taking into account that the reverses of the blades generate a turning moment opposite to the movement, which lowers the power coefficient, Cp, of the

4 Or air turbine. The invention recommended in this patent solves this technical problem, increasing the Cp, by eliminating the opposite turning moment of the backs of the blades, and also simplifies and economizes the blades and allows to continue operating with winds higher than the nominal.

45 Another fundamental aspect of aeroturbine focuses on variable admission. It is known in the state of the art that wind rotors cannot enter a loss of lift if they are towing and therefore, the drag force will always be proportional to the square of the wind speed. The invention advocates a variable intake that prevents wind rotor rotor packing, as described above.

5 The other fundamental aspect of the turbine is addressing. The turbine should be oriented with the wind direction. As the turbine has asymmetry with respect to its axis of rotation, the invention recommends the use of an adjustable vane. Front view of the housing, in the wind direction, it presents when the

10 mobile housing is open, from the longitudinal axis, two halves with different drag coefficient (also called resistance coefficient). Each half will be subjected, due to the dynamic wind flow, to the following drag force: 1 2

FD = CD-i-P-A-v

where Co is the drag coefficient, p the wind density, A the projected area in the vertical plane normal to the wind direction and v the wind speed.

As the left half will have a Co that we will call COI, which has the variable opening, and similarly to the right half Coo, which has the closed contour, we will have the corresponding forces:

1 2

POi = CD1 --- p-A-v

25 We can have two cases, well differentiated:

Case A: The wind rotor has not been placed in the Aeroturbine. Case B: The wind rotor has been placed in the Aeroturbina.

3 O Case A will never occur in the operation of the invention, but it is very simple to solve and is set forth by way of illustration.

Case B is the one that will always occur in the operation of the invention, and due to its complexity of resolution it has been solved using computational techniques of fluid dynamics (CFD). The results, in the form of a color chart, are shown in Figure 12.

Case A 40 We know that

COI> Coo, when the opening is fully or partially open, the difference being maximum when the opening is 100%.

._ - _.........

._ ---- _.

CoI = Coo, when the opening is fully closed.

These forces Col and Coo will give rise in a general case to the following moment of rotation, 5 with respect to the axis of rotation:

Mo = (FDI-FDD) · L

where L is the length from the direction of the resultant forces and the axis of rotation.

If we substitute each force for its expression and we will have:

1 2

Mo = (CDl -CDD) · L · i · p. TO . v 15 It follows that regardless of wind speed, the torque will be zero if we equalize the drag coefficients of the left and right sides. For this, the invention advocates a weather vane that has a variable disorientation angle q>, depending on the degree of admission opening, which makes COI = Coo at all times. 20 CaseB

Due to the influence of the wind rotor, both at rest and in motion, we will have to:

25 Col <Coo, when the opening is fully or partially open, the difference being maximum when the opening is 100%.

Col = Coo, when the opening is fully closed

30 The torque that is produced will therefore be of the opposite sign from the previous case, being resolved analogously to the previous case, by means of a weather vane that presents a

variable disorientation angle q>, depending on the degree of admission opening, which makes COI = Coo at all times, but in this case, the angle, is 3 5 opposite that of the previous case. The power of any turbine will be expressed approximately by:

1 2

p = Cp · --p · A · ll

4 Or where Cp is the power coefficient, p the wind density, A the projected area of the pickup surface in the vertical plane normal to the wind direction and v the wind speed.

The Cp cannot exceed the theoretical maximum of 16/27, called Betz Limit. The Cp of a typical vertical drag aeroturbine hardly exceeds the value of 0.2, due to the moment of antagonistic rotation created by the backs of the blades. For a typical concave obverse blade with Cp = 1.4 Y of convex reverse with Cp = 0.4, the elimination of the moment of antagonistic rotation means a maximum improvement of 40%. Therefore, by similarity we can estimate in a simple initial model, that the invention advocates an improvement in the power coefficient with respect to the typical drag turbines of the state of the art of the order of 40%. This increase in the Cp makes possible and advises the use of this type of drag turbines, which on the other hand present

10 the advantage that they need a lower starting wind speed than those of lift.

It should be noted that in addition to the variable opening mobile housing, the device has another fixed housing, so named because it remains fixed when the air intake and outlet vary, but together they both rotate simultaneously with respect to the support column for orient to the horizontal direction of the wind.

The fundamental application of the invention is that of its location in low wind speed sites, such as in urban spaces, as well as in 2 O locations that may have extreme wind speeds with gusts of wind up to 10 or even value higher according to the Beaufort Wind Force Scale (according to computer simulations), such as mountain observation posts and remote facilities for research. In addition, the invention presents protection for birds, because the housing significantly reduces contact with the wind rotor and minimizes visual impact, since the housing makes it impossible to see the movement of the wind rotor and because in the inlet opening and in the airflow outlet opening, a filter can be arranged to prevent the entry of insects, birds and drag material. Said filter can be arranged in the mobile housing so that when there is an opening

3 Or the filter is visible and when there is no opening said filter is inside the fixed housing.

35 Background of the invention

Different types of aeroturbines are known in the state of the art, which normally admit a first classification according to the horizontal or vertical position of the axis of rotation of the aeroturbine. A second classification is made according to its 4 O principle of operation, based on "Drag" drag forces, "Lifl" lift forces, or a mixture of both. The Darrieus model is well known, being of vertical axis and mainly of support; also the Savonius model, being of vertical axis and of drag; as well as the monopala, bipala, and tripala models constructed by means of an aerodynamic profile, these being horizontal and

45 mainly of support.

Horizontal axis wind rotors are known that present numerous problems and disadvantages, such as the need for an expensive blade rotation system for rotor regulation, or a mechanical brake for rotor stopping, as well as the need to have to remain out of service when the winds are higher than

5 the nominal ones, since if they do not stop the breakage of the same ones can take place, offering these a great resistance in virtue of their horizontal position.

In addition, the vibration that the horizontal axis rotors support during operation is very pronounced, as well as the generation of high noise, resulting, on the other hand, harmful to birds, in addition to generating visual pollution due to the visibility of the turn of the rotor.

Vertical axis wind rotors are known, all of them suffering from low energy efficiency as previously mentioned.

15 Air turbines such as those mentioned can be seen in the documents: US1219339; US3743848; US3793530; US3995170; US4115032; US4208168; US4278894; US7083382; ES2364828; ES2180443; ES2209172; ES2336084; PL200550; among many others.

20 These turbines have a problem that focuses primarily on the following aspects:

-

They require blades with a very complex aerodynamic profile that makes them very expensive and also have to be oversized to withstand higher than nominal winds and withstand high vibrations until they go out of service.

-

They require a complex braking system in the presence of winds higher than the nominal ones, and it is also necessary to leave the aeroturbine out of service, not 3 or being able to take advantage of any of the high energy available at that time to the high-speed air flow.

-

They require, those of horizontal axis, to be placed at high altitude to avoid the friction of the blades with the ground or with the vegetation, in addition to having to maintain a protection distance 35.

-

They cause great visual pollution, by moving blades, and noise pollution.

4 OR -The vertical axis, which does not need an orientation or braking system, has a very low power coefficient.

The aeroturbine that the invention recommends solves in a completely satisfactory way the aforementioned problem, in each and every one of the different aspects mentioned.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a perspective view of a preferred embodiment of an turbine according to the invention 1.

Figure 2 shows an elevation view of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: to the left of its vertical symmetry axis, the mobile air inlet housing 106, in its maximum opening state, and to the right, the fixed housing 105.

Figure 3 shows a profile view of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: to the left of its axis of vertical symmetry, the fixed housing 105, and to the right, the mobile housing 106, air outlet, in its maximum opening state.

Figure 4 shows an elevation view of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: to the left of its axis of vertical symmetry, the mobile housing 106, of air inlet, in its state of minimum opening or complete closing, and to the right, the fixed housing 105.

Figure 5 shows a profile view of a preferred embodiment of an turbine according to the invention, in which it can be seen: to the left of its axis of vertical symmetry, the fixed housing 105, and to the right, the housing mobile 106 air outlet, in its state of minimum opening or complete closing.

Figure 6 shows a section of the elevation view of a preferred embodiment of an turbine according to the invention 1, in which the wind rotor 107, the section of the fixed housing 105, the section of the mobile housing 106, the drive shaft 10 1, and other elements.

Figure 7 shows two plan views of a preferred embodiment of an turbine according to the invention 1, in which the position of the lever 110, which makes the mobile housing 106, can be observed in the top view. is open to

100%, and that the vane 109 is displaced by its variable disorientation angle cp, maximum 35, and in the bottom view, the position of the lever 110, which causes the mobile housing 106 to be open at 0% or completely closed, and that the vane 109 is

shifted its variable disorientation angle cp, minimum or null.

Figure 8 shows a profile view of the regulating chamber 108 of a

4 Or preferred embodiment of an turbine according to the invention 1, in which the output of the lever 110 can be observed, indicating the degree of opening of the mobile housing 106.

Figure 9 shows a section of an elevation view of the regulation chamber 108, 45 of a preferred embodiment of an turbine according to the invention 1, in which the stages and elements of its interior, as well as the anemometer, can be schematically observed 1080, located at the top.

Figure 10 shows a section of a plan view of a preferred embodiment of an turbine according to the invention 1, in which the air flow lines can be observed, when the mobile housing 106 is 100% open and the Vane 109 displaced its variable disorientation angle q>, maximum.

Figure 11 shows a section of a plan view of a preferred embodiment of an turbine according to the invention 1, in which the air flow lines can be observed when the mobile housing 106 is open at 0% (closed) and the weather vane

109 displaced its variable disorientation angle q>, minimum or null.

Figure 12 shows a graph of colored velocity vectors according to the magnitude of velocity.

DESCRIPTION OF A PREFERRED EMBODIMENT

2 O Figure 1 shows a perspective view of a preferred embodiment of an turbine according to the invention 1. In order not to compromise the graphic clarity, the anemometer has not been drawn, which instead appears in the rest of the figures .

Figure 2 shows an elevation view of a preferred embodiment of a

25 turbine according to the invention 1, in which it can be seen: to the left of its axis of vertical symmetry, the mobile air inlet housing 106, in its maximum opening state, and to the right, the fixed housing 105, Y in which the transmission shaft 101 can be seen, which is rigidly connected to the wind rotor 107, and which runs through the inside of a support column 102, and in which the chamber of

3 O regulation 108, which regulates the position of the mobile housing 106 Y of the vane 109. The vane 109 is connected by its arm 111 to the regulation chamber 108,

using a variable disorientation angle q>, which guides the air inlet opening caused by the mobile housing 106, according to the wind direction. The regulation chamber 108 is rigidly attached to the fixed housing 105.

Figure 3 shows a profile view of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: to the left of its axis of vertical symmetry, the fixed housing 105, and to the right, the mobile housing 106 of air outlet, in its maximum opening state.

Figure 4 shows an elevation view of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: to the left of its axis of vertical symmetry, the mobile air inlet housing 106, in its minimum opening or complete closing state, and to the right, the fixed housing 105.

Figure 5 shows a profile view of a preferred embodiment of an turbine according to the invention, in which it can be seen: to the left of its axis of vertical symmetry, the fixed housing 105, and to the right, the mobile housing 106 of air outlet, in its state of minimum opening or complete closing.

Figure 6 shows a section of the elevation view of a preferred embodiment of an turbine according to the invention 1, in which the wind rotor 107, the section of the fixed housing 105, the section of the section can be observed in detail. mobile housing 106, and the drive shaft 101 running through the support column 102. The drive shaft 101

10 is supported to the fixed housing 105 by means of two bearings 103A and 103B. The fixed housing 105 is supported on the support column 102 by the bearing 104, being able to rotate freely to orient the air inlet to the wind direction. The fixed housing 105 differs from the mobile housing 106, because it remains fixed when the air intake and outlet vary, but together they both rotate simultaneously with respect to

15 support column 102.

Figure 7 shows two plan views of a preferred embodiment of an turbine according to the invention 1, in which it can be seen: in the top view, the position of the lever 110 that makes the mobile housing 106 open to the

2 O 100% And that the vane 109 is displaced by its variable disorientation angle cp, maximum, and in the bottom view, the position of the lever 110 which causes the mobile housing 106 to be open at 0% or complete closure, and that vane 109 is

shifted its variable disorientation angle cp, minimum or null. The lever 110 attached to the mobile housing and the arm 111 attached to the vane 109 generate the simultaneous movement 25 that can be seen in the views of the figure, but in their movement they generate different angles. For example, for a preferred diametrically opposed air inlet and outlet opening of 90 °, the lever 110 will travel 90 ° simultaneously with the arm 111, which will travel the variable disorientation angle

cp, own of the aeroturbina. This is achieved with any simple mechanism, 3 O widely known in the state of the art, and which is included in step 1082 which is a motorized dual output orientation system, described in the

Figure 9. The variable disorientation angle cp depends on several factors, the main one being the geometry of the fixed and mobile housings 105 Y 106 and the vane 109. Each

Specific type of aeroturbine will have its own cp variable disorientation angle, 35 whose value will be obtained through computational fluid dynamics techniques and validated in a wind tunnel.

Figure 8 shows a profile view of the regulation chamber 108 of the mobile housing 106 Y of the vane 109 of a preferred embodiment of an turbine according to the

4 Or invention 1, in which the output of the lever 110 can be observed, with indication of the degree of opening of the mobile housing 106

Figure 9 shows a section of an elevation view of the regulation chamber 108 of a preferred embodiment of an turbine according to the invention 1, in which it can

Observe schematically the stages and elements of its interior, as well as the anemometer 1080, located in its upper part. The anemometer 1080 has two functions: to generate the wind speed signal and feed the same signal to stage 1083. Stage 1083 is an electric energy accumulator that incorporates a simple charge regulator, and that feeds electrical energy. to the rest of the stages Step 1081 is a programmable microcontroller, which captures the signal from anemometer 1080, and captures the speed of rotation of the drive shaft 101, and which sends the signal corresponding to step 1082, which is a motorized dual output orientation system. . The step 1082 acts simultaneously on the lever 110, integral with the

10 mobile housing 106, and on the arm 111, integral with the vane 109. The operating procedure, programmed in step 1081, is based on

the wind speed (although a continuous opening function can also be programmed) and the rotation axis speed, either by sections or continuously, as for example shown below with a 5-section control (value

15 nominal and 3 preset maximum values):

start:

o: s wind speed: s nominal Y

2 O packing speed> shaft speed then: open mobile housing 106, 100% and move vane 109, at a = 100%

25 nominal <wind speed: s 1 maximum and packing speed> shaft speed then: open mobile housing 106, at 75% and move vane 109, at a = 75%

30 maximum 1 <wind speed: s 2 maximum and packing speed> shaft speed then: open mobile housing 106, at 50% and

35 move vane 109, a a = 50%

maximum 2 <wind speed: s maximum 3 Y packing speed> shaft speed so:

4 Or open mobile housing 106, at 25% and move vane 109, at a = 25%

maximum 3 <wind speed OR packing speed <shaft speed 45 then: open mobile housing 106, at 0% and

move vane 109, a a = 0%

at the beginning:

Figure 10 shows a section of a plan view of a preferred embodiment of an turbine according to the invention 1, in which the air flow lines can be observed when the mobile housing 106 is 100% open AND the vane 109

shifted its variable disorientation angle <p, maximum. In the indicated position,

10 the air inlet is perfectly oriented with the wind direction, said position being the nominal operating. When the anemometer records higher than nominal winds, stage 1081 gives order to stage 1082 to

move the mobile housing 106 And reduce the variable disorientation angle <p of the vane 109, closing the air inlet but maintaining the orientation indicated in the

15 figure.

Figure 11 shows a section of a plan view of a preferred embodiment of an turbine according to the invention 1, in which the air flow lines can be observed when the mobile housing 106 is open at 0% (closed) and the weather vane

2 or 109 displaced its variable disorientation angle <p minimum or null. This situation occurs when the anemometer registers winds higher than the structural maximum: step 1081 orders step 1082 to move the mobile housing 106 to the maximum and cancel

the variable disorientation angle <p of the vane 109, closing the air inlet but maintaining the orientation indicated in the figure.

25 Figure 12 shows a graph of colored velocity vectors according to the magnitude of velocity. It was obtained by performing a simulation for a speed V of 10 mis, and for a rotation of the impeller of 35 r.p.m.

Claims (5)

 Claims 1. Vertical-axis drag turbine with variable intake 1, to take advantage of the kinetic energy of the airflow, valid in low-speed locations 5 of wind, such as urban spaces, and in locations that may have extreme wind speeds with wind gusts of 10 or higher according to the Beaufort scale, of which they have:

-

a support column that supports the rest of the elements by means of a

10 bearing; -a mobile housing that modifies the air flow that reaches the wind rotor; -a wind rotor that captures the kinetic energy of the air flow and transmits its rotating movement through a transmission shaft; 15 characterized by the following configuration of elements and their relative arrangement in the set:

-

a fixed housing 105 with two openings to regulate, together with a mobile housing 106 which also has two openings, totally or partially the flow 2 O of air that reaches the wind rotor, the air inlet opening being identical at all times to the exit, but standing diametrically opposite;

-

a vane 109, which has a variable disorientation angle a, with respect to the edge of the air flow inlet, which guarantees that at all times the air inlet opening is aligned with the incident air flow;

-

a regulation chamber 108, which by means of an anemometer 1080, has a series of devices capable of controlling the variable disorientation angle a and the degree of opening caused by the mobile housing 106, with respect to

3 Or the fixed housing 105. 2. Vertical-axis drag turbine with variable intake 1, according to claims 1 and 2, characterized in that the mobile housing 106 has an independent degree of freedom in its movement with respect to the fixed housing 35 105. 3. Vertical-axis drag turbine with variable intake 1, according to claims 1 and 2, characterized in that the fixed housing 105, and the mobile housing 106, are in the form of a hollow radial revolution solid, preferably 4 Or cylindrical. 4. Vertical axis drag turbine with variable intake 1, according to claims 1 and 2, characterized in that a filter can be provided in the inlet and outlet openings of air flow to prevent the entry of 45 insects, birds and drag material.

5.

Vertical axis air turbine drag with variable admission 1, according to

claims 1 and 2, characterized in that the wind rotor is a turbine of

radial flow of a plurality of flat blades.

5

6. Procedure for generating electricity using device 1,

consisting of moving an electric generator using work

developed by wind turbine 107, and transmitted by the drive shaft

101, through a series of transmission mechanisms characterized by

Wind speed and shaft speed are simultaneously compared

10

rotation with preset setpoints.

fifteen