INVENTION
Russian Federation Patent RU2118699

Wind turbines AND ITS WORK

Wind turbines AND ITS WORK

Name of the inventor: NM Bychkov
The name of the patentee: Institute of Theoretical and Applied Mechanics
Address for correspondence:
Starting date of the patent: 1996.06.18

Wind turbine is designed to convert wind energy into energy for the user and can be used in a wide range of wind speeds, including storm without additional energy costs. The radial cylinders wind turbines with a horizontal axis of rotation of the component made from a non-rotating and rotating the end of the root. Each of the cylinders has two turbulators. According to the first embodiment, the turbulators are arranged along the cylinder with the angular coordinates relative to the wind direction, j = o 45 1, j 2= -90 o. In a second embodiment of baffles mounted in a spiral around the cylinder axis with angular coordinates relative to the wind direction j == 1 (1 + kr / R) W @ 30 o 45 o; j = 2 - (1-k / 2 × r / R) 90 H o. Wherein the first and second embodiments of turbulators are arranged asymmetrically relative to the wind direction and with clearance relative to a certain magnitude cylinder surface. Self-propeller carried by the wind force generated by turbulence on the surface of the cylinders.

DESCRIPTION OF THE INVENTION

The invention relates to wind energy and wind turbines with regard to the rotating cylinder is used to operate the Magnus effect. Last characterized by the appearance of lift (Magnus force) for rotating the cylinder in cross-flow [1]. This force is used to rotate the propeller, similar to the lift of the blade, but it has a much greater value.

A method is known for creating a non-rotating lift cylinder via superstructures mounted thereon along one side and having a semicircular shape [2]. These add-ins provide a cross-flow cylinder asymmetry that causes lift, comparable in magnitude to lift the blade. The maximum value of this force is achieved when superstructures location directly on the cylinder surface 90 at points o and -90 o, measured from the wind direction, while the force acts in the direction opposite the location of the superstructure.

The known plant - the wind turbine rotor with a horizontal axis of rotation, comprising a superstructure with radial cylinders in the form of plate interceptors arranged along one side of the cylinder. The cylinders are rotatable around their axes [3].

The disadvantages of this setup are limited opportunities for self-working and self-propeller, including the stabilization of its rotation at high wind speeds; limited possibilities of increasing the length of the rotating cylinder, and hence the diameter of the propeller; insufficiently high capacity due to the limited diameter of the propeller; increased power costs for the rotation of the cylinder lengths. The object of the invention is to improve the efficiency and capacity of wind power, but also the possibility of aerodynamic self and self-regulation in all modes of operation, without additional energy costs in a wide range of wind speeds, including storm.

The task implemented on wind turbines with a horizontal axis of rotation of the propeller, radial cylinders which are made components of the rotating terminal and nonrotating root portion, and each of the cylinders is provided with two turbulators in the form of tubes located along the cylinder at opposite sides thereof, and asymmetrically relative to the direction of wind with angled coordinates

j 1 = 45 o and j 2 = -90 o

The presence of two vortex generators (instead of one on [2, 3] provides the appearance of the total aerodynamic force, which allows more effectively launch and propeller control. Thus there is a self-starting and self-regulation works, up to a maximum of (storm) wind speeds. Self-regulation is achieved by varying strength produced on the cylinders under the influence of turbulence, rejecting speed propeller from the calculated (specified). The result is a compensating force that restores the calculated (specified) propeller speed. Self-regulation by means of turbulence is supplemented by regulation by changing the engine speed. at the same time with increasing the speed of the effect of wind turbulence increases and the effect of rotation of the cylinder, on the contrary, decreases. At high wind speeds, the unit operates only due to turbulence, without rotation of the cylinder, which significantly extends the capabilities and efficiency of the installation.

The use of composite cylinders with rotating and non-rotating end root portions can significantly increase the power of wind turbines, but also its effectiveness. Increased capacity is achieved by adding a non-rotating portion of the root that allows to increase the total length of the cylinder, and hence the diameter of the propeller, and the power is proportional to the square of the diameter. At the same time rotating cylinders having a great lift (engine) power, used more effectively, since It is located at a greater distance from the rotational axis of the propeller and therefore produce higher torque. In the presence of non-rotating cylinders and create turbulence torque which increases with the length and diameter of the cylinders.

In the presence of a non-rotating part of the root at the same time reduced power costs for the rotation of the cylinder end of the decrease in their length in relation to the total length of the cylinder. Moreover, such a wind wheel has increased strength, as determined by circular most robust form cylinder and its larger diameter portion of the non-rotating and rotating the propeller and low speed (about 5 times lower than the paddle).

These characteristics are not found in other technical solutions in the study of the level of the art and, therefore, the proposed solution is new and involves an inventive step. The proposed engineering solution is industrially applicable, in particular, wind energy.

FIG. 1 shows a general view of wind turbines; FIG. 2 - longitudinal turbulator arrangement diagram in section A-A in Fig. 1; FIG. 3 - lift coefficient nonrotating cylinder depending on the angular position of the turbulator T 1 (experimental data ITAM); FIG. 4 - also with turbulence T 1 and T 2 at different Reynolds numbers (ITAM data); FIG. 5 - the influence of the Reynolds number on the lift coefficient of the cylinder with turbulence T 1 (curve C 1) and T 2 (curve C 2) for j = 1 and j 45 o -90 o = 2 (bright icons - ITAM data, dark icons - data [2], Fig 6 - the same for the total lift coefficient;.. Figure 7 - cylinder flow diagram with turbulence T 1 and T 2 at start-up conditions (without rotation of the cylinder and the propeller). FIG 8 - also on the settlement operation propeller;. Figure 9 - the frequency of rotation of the propeller in dependence on the parameter Q - relative speed of rotation of cylinders, with turbulators (curve 9) and without (curve 10) including Re = 0,7 × 10 May (ITAM data ).

Wind turbine (Fig. 1) comprises a wind wheel with horizontal axis of rotation, which is installed on a fixed support (tower), and it can be rotated in the direction of the wind (like a conventional schemes). Wind wheel consists of a housing 1 with front and rear fairings, non-rotating part 2 and cylinder part 3 with the rotating endplate 4 which restrict unwanted overflow stream. The length of the cylinder is rotating at L = a L, respectively for the non-rotating part of the L n= (1- a) L, where L - total length of the cylinder, a = 0,4-0,6. Nonrotating diameter of the cylinder is 1.5 - 2 times greater than the rotating part.

The end portions are thin walled cylinder shell which, through the cantilever bearing planted on the shaft and are rotated by individual drives arranged on the shaft end (not shown in the drawing). The shaft is cantilevered to the fixed end of the cylinder. The drive is powered by an electric wind turbines. Backup power supply - the battery. The generator is rotated by the wind wheel through a multiplier that increases the speed up to the values ​​necessary for the operation of the generator.

FIG. 2 shows a circuit arrangement of the turbulators T 1 - T 2 and 5 - 6, which are arranged along each cylinder and are formed as tubes with a diameter d t = (0,1 - 0,02) d and the length L m = L + aL inn, where d - diameter of the cylinder, a = 0,2 - 0,8 (depending on the nature of the construction and operation of wind turbines). The distance from the cylinder surface to baffle T 1 is h 1 = (0,1 - 0,2) d, to baffle T 2 is h 2 = 0 - on a non-rotating part and h 2 = (0,02 - 0,05) d - around the cylinder rotating part. The angular position of the turbulators T 1 and T 2 are respectively j 1 = 45 o and j 2 = -90 o, where angles j 1 and j 2 are measured from the front of the critical point of cylinders (from the direction of the wind), and j 1 - in the direction of rotation cylinders, j 2 - vice versa.

Work in wind turbines depends largely on the turbulence T 1 and T 2. The mechanism of their effect is rather complicated. Let us dwell on it in more detail. Appointment of turbulence - the creation of the aerodynamic force Y r - in addition to the basic power of Magnus Y m generated by the rotation of the cylinder (see figure 1..). Power Y t Y unlike m occurs on a non-rotating cylinder, and its value decreases as the cylinder rotates. Source of occurrence force Y r - asymmetry flow cylinder due to asymmetric vortex arrangement, namely j 1 <| j 2 |, h 1> h 2, and j 2® 90 o, h2® 0. Under these conditions, the effect of baffle T 2 effect in the near its surroundings, causing flow separation directly behind the baffle. Turbulator T 1 contrast T 2 does not act locally, and through a relatively lengthy transitional separated processes in the boundary layer of the cylinder (the transition from the laminar state to the turbulent intermediate stages to form a so-called separation bubble - closed area between the points of the laminar separation and reattachment boundary layer in a turbulent state, then there is a final flow separation). As a result, the point of flow separation under the influence of baffle T 1 moves up to the tear-off angle j = 130-140 o, and under the influence of baffle T 2 is fixed near the angle j Neg= -100 o [2], there is a flow around a cylinder with the advent of power asymmetry Y ie, directed towards the lower pressure (the point where separation is displaced further downstream). The strength of Y t is used during start-up of the wind wheel, including a non-rotating cylinders, and for self-operation of wind turbines at a deviation from the design mode.

Below are the results of the test cylinder with turbulence in the wind tunnel of ITAM. FIG. 3 shows a graph of the lift coefficient C y for a non-rotating cylinder depending on the angular position around the turbulator cylinder T 1, and FIG. 4 - also for the turbulence T 1 and T 2. Where C = Y inr / q × S, where q = r V 2/2 - velocity head, S = d L × t - area, r - air density. It is seen that the coefficient C y depends on the magnitude and sign of the angle turbulator installation. If you change the angle mark j 1 and j 2 C coefficient of it is reversed. Maximum positive value at C is achieved in the field j = 30-50 o 1 and j 2= -90 o

The coefficient C y depends on the Reynolds number, which is expressed as Re = V × d / n, where n - the kinematic viscosity of air. FIG. 5 shows the experimental data for the components of the coefficient C in steps of 1 T baffle (curve C 1) and T 2 turbulator (curve C 2) depending on the number Re at the installation angles of the turbulators 45 = j 1j 2 and o= -90 o.

There bright icons marked data ITAM, dark icons - data [2]. The graphs show that the C 2 ratio is always positive, and the C 1 coefficient changes its sign reversed when passing through the critical number Re cr = 5 × 10 5.

The observed behavior of the coefficients C 1 and C 2 significantly expands the opportunities for self-regulation and self-propeller in relation to the variant with one baffle T 2 (prototype). This follows from the graph in FIG. 6, which shows the total value of the coefficient C f = C 1 + C 2, depending on the Reynolds number (angle j 1 and j 2 are the same as in FIG. 5). In subcritical numbers Re <Re cr = 5 × 10 5 C e ratio> C 2, that is, we have an increase in C is, in relation to C 2 by C 1, which improves the startup propeller and operation at wind speeds of up to 10 - 20 m / with the corresponding specified number Re. When supercritical numbers Re> Re cre have C <C (decrease C e) is also due to a C 1, which limits unwanted speed propeller growth with increasing wind speeds and even allows you to stabilize this rate at a fairly constant level.

The end result of the action of turbulence T 1 and T 2 depends on the wind speed and hence on the Reynolds number and the angular position and the turbulators and their length, which may be different for T 1 and T 2. In particular, the increase in the length T 1 improves launch conditions and limits the speed of the propeller at high wind speeds. Conversely, increasing the length of T 2 increases the propeller speed at high wind speeds, which can be dangerous.

Wind turbine operates as follows. At start-up conditions, when there is no rotation of the cylinder and the propeller (w = w yk = 0, 7) turbulators T 1 and T 2 at the position of the impact point of flow separation (through the mechanisms described above) and create flow asymmetry cylinder: 7, the separation point is downstream than the point 8. There is a pressure differential on the upper and lower sides of the cylinder with the advent of the aerodynamic force Y t, which causes the wind wheel into a rotary motion. The rotation of the propeller is transmitted through the multiplier on the generator, from which the generated electric power is supplied to the cylinder rotation. When you rotate the latter a force Magnus Y m, the effect of which increases propeller speed and thus the speed of the generator, which results in a current mode of operation of wind turbines corresponding to the estimated wind speed and installed a power generator.

When starting the propeller generator power is used only for the cylinder rotation. After the release of the payment mode power costs for the rotation of the cylinder form only a small part of the total capacity of the generator. These costs are reduced with the decrease of the rotating cylinder length. In the absence of a non-rotating portion to rotate root power costs up to 10 - 12%. By reducing the length of the cylinder rotating part due to a non-rotating part of these costs are reduced by at least a factor of 1.5. Moreover, with the increase of wind speed above the design value increases turbulence effect, and the effect of rotation of the cylinder, on the contrary, decreases, which creates conditions for further reducing power costs for the cylinder rotation up to zero at a sufficiently high wind speeds.

The growing influence of turbulence with increasing wind velocity follows from the fact that the power of any wind turbine has the form

N = K B C F H V H 3 S; S = d W L T,

Where

K - coefficient of proportionality;

S - area (in this case S = d L × t;

C F - propeller drive force ratio, which depends on the magnitude of lift and drag of the cylinder and is a function of the coefficients C 1 and C 2, the above-mentioned (see FIGS 5, 6,..). The formula implies that the power is proportional to the cube of the wind speed. Then, at constant values ​​of K, C and S increase in wind speed, such as twice the capacity would lead to an increase of 8 times, which may exceed the capacity of the rotating cylinder and, consequently, their rotation is not required, will only wind wheel through the turbulators.

On the other hand, the current mode of operation of the wind wheel is achieved at a certain optimum value of the relative speed of rotation of the cylinder

Q = w u d / 2V = 2-3,

which shows that with an increase in wind speed, but at a constant frequency of rotation of the cylinder w n = const, Q value decreases. This means lower the contribution to the total cylinder rotating propeller power, and hence power costs rotating cylinders can be reduced compared to the conditions in the current mode, where these costs are maximized.

FIG. 8 shows the pattern of flow around a cylinder in the current mode. Rotation of the propeller is carried by a driving force F <Y = Y t + Y m when decelerating drag force action cylinder (not shown on the diagram). When rotating propeller arises circumferential component of the flow velocity, and as a result the total flow around each cylinder with a total speed V e, is rotated from its original direction (from the velocity vector V) by an angle Je. The optimal condition for this equality of angles is Je = j 1 (shown in FIG. 8). In this case the turbulator T 1 does not generate the driving force, but reduces the resistance of the cylinder, which increases the efficiency of the propeller. Turbulator T 2 at a certain part of its length is in this case in the wind shadow, ie 8 behind the separation point, where it enters, starting from the end sections where the peripheral speed is higher, so Je angle larger than the root sections. Changing the pattern of flow around cylinders associated with the deflection, it creates the conditions for self-regulation works via propeller turbulence T 1 and T 2.

Self-regulation works propeller follows. In the event of a settlement mode, ie, with an increase or, conversely, decrease the speed of the propeller design value accordingly varies the angle characterizing the direction of the velocity V is, total flux incident on the cylinder (see. Fig. 8). This means that the original, optimal condition Je = j 1 is broken, there is a misalignment angle Dj = j 11 - 0 je№.

If there is a mismatch of the angle under the influence of baffle T 1 appears restoring force D Y 1(Dj 1), the magnitude and sign of which vary according to the schedule behavior factor FIG. 3 and 4. By increasing the speed of the wind wheel is the angle Dj 1 <0, the force D Y 1 <0, and vice versa, which helps to restore the original (estimated) mode. T 2 turbulator unlike T carries 1 wherein the self-regulation by changing the length of the active part of the baffle located outside the aerodynamic shadow. With increasing speed propeller, ie Dj at 1 <0, the active part length of the baffle decreases T 2, Y 2 force also decreases, and vice versa, helping to restore the initial operating mode.

FIG. 9 according to the results of wind tunnel tests at ITAM including Re = 0,7 H May 10 shows the propeller speed to n depending on the relative rotational speed of the cylinder Q = w i d / 2V if turbulators (curve 9) or without ( curve 10). It can be seen that the baffles provide self-starting wind wheel (n> 0 at Q = 0), a and n to increase with in Q <1, ie, an increase Q We have improved propeller characteristics as compared to the embodiment without turbulence. When Q <0,5 windwheel without turbulence can not be started, and with turbulence rotates at a rate sufficient for the initial electric operation, providing electric power cylinder rotation. The rotation of the cylinder, as already noted, contributes to further increase the speed of the wind wheel and the achievement of a settlement mode with the self-regulation by turbulence T 1 and T 2. If necessary extra regulating cylinder by changing the rotational frequency, which is most effective when the estimated wind speed and deviations from it to 50%. With an increase in wind speed is more than twice the cylinder speed regulation will be ineffective, as is evident from the graph in FIG. 9.

Thus, the regulating effect of the turbulators T 1 and T 2 depends on the deviation of the actual speed of rotation of the propeller design value, which is reflected angle mismatch Dj 1. The latter, in turn, depends on several parameters: the length and angle of the turbulators their installation, the wind velocity and the Reynolds number, the cylinder rotation frequency. By selecting the length of the vortex and the angle of installation provides the most optimal conditions for the self-propeller, and to secure its operation at higher wind speeds and storm. For this purpose, at the initial stage of operation is appropriate to reduce the length of the baffle T 2 to a minimum, allowing to provide a baffle with one self-starting wind wheel T, and at the same time limit the rate of rotation to a safe level at high wind speeds. It should further be able to increase the length of the turbulator T 2, if the wind speed with increasing propeller rotational speed will drop below the required values, as is the case for the propeller without turbulence, which is evident from the graph in FIG. 9.

Angles turbulator installation mentioned above, j = 1, 45 o, j2= -90 o, (see. P. 1 of the claims) are optimal for self-propeller, but not optimal for self-regulation of its operation, since There are limits on the circumferential cylinder speed and the propeller, and the number and Reynolds number.

To simultaneously satisfy these conditions baffles installed as follows (see. P. 2 claims)



where R - radius of the wind wheel, r - distance from the propeller axis, k = 0,5 - 0,8 - coefficient dependent on wind turbine design and operation, and k <0,6 at numbers Re <Re cr and k> 0, 6 at numbers Re> Re cr. On a rotating angle of the cylinder j 1 shall not exceed 45 o.

The minimum wind speed at which the propeller to start rotating cylinders (with their drive power from the batteries or other external power supply) is about 1 m / s. The wind speed at which the self-starting wind wheel under the influence of turbulence without rotation of the cylinder (fully autonomous operation), is about 3 m / sec. Working wind speed range for the propeller rotating cylinder with turbulence and ranges from 2 to 40 m / s, which significantly overlaps that of traditional vane wind turbines.

CLAIM

1. Wind turbine comprising a wind wheel with a horizontal axis of rotation and radially mounted cylinder end washers and the longitudinal vortex generators, and a cylinder and an electric drive, characterized in that the cylinders are made of a rotating component and a nonrotating root end portions, and equipped with two turbulators in the form of tubes, cylinders along with angular coordinates relative to the wind direction 1j = 45 °, j 2= -90 ° and the gap h 1 = (0,1-0,2) d, 0 <h <0,05d, where d is the diameter of the tubes T = (0,1-0,2) d, their length L t = L + aL inn, where d - diameter of the cylinder; h 1, h 2 - the distance from the surface of the cylinder to the corresponding baffle; L n - length of the non-rotating part of the cylinder; In L - the length of the rotating part of the cylinder; a = 0,2 - 0,8 - coefficient depending on the design of the installation and operating conditions.

2. Wind turbine comprising a wind wheel with a horizontal axis of rotation and radially mounted cylinder end washers and the longitudinal vortex generators, and a cylinder and an electric drive, characterized in that the cylinders are made of a rotating component and a nonrotating root end portions, and equipped with two turbulators in the form of tubes, installed spirally around the cylinder axis with angular coordinates relative to the wind direction



where r - the distance from the axis of the propeller;

R - radius of the wind wheel;

k = 0,5-0,8 - coefficient depending on the design of wind turbines and the mode of operation,

and the gap h 1 = (0,1-0,2) d, 0 <h <0,05d, where d is the diameter of the tubes T = (0,1-0,2) d, their length L t = L + aL inn, where d - diameter of the cylinder; h 1 h 2 - the distance from the surface of the cylinder to the corresponding baffle; L n - length of the non-rotating part of the cylinder; In L - the length of the rotating part; a = 0,2 - 0,8 - coefficient depending on the design of the installation and operating conditions.

3. The method of operating a wind turbine comprising a propeller start, power generation and its regulation, characterized in that a self-starting wind wheel by means of aerodynamic force generated by turbulence at the surface of the cylinder, the received energy is partially transmitted to the drive cylinders moving parts to achieve regular operation mode setting and support this mode constant by compensating forces turbulence and further control cylinder speed from nominal to zero.

print version
Publication date 10.04.2007gg