RU2660759C1 - Method of forcing horizontal-axial wind turbine - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to wind power engineering. Method of forcing a horizontal-axial wind turbine, consisting in the fact that the blade of the forced wind turbine is deduced in the tip part at the supercritical, in the angle of inflow of the air flow, the flow regime by decreasing the angle of relative twist of the sections of the selected blade prototype with the installation along the leading edge of such a slat blade.

EFFECT: invention is aimed at obtaining the maximum possible coefficient of wind energy use.

1 cl, 2 dwg

Description

FIELD OF THE INVENTION

The invention relates to the field of technology using the energy of air flow, wind (high-pressure).

State of the art

The present invention describes a method of forcing a horizontally axial wind turbine and determines its scope.

In this invention, a one-, two- or three-bladed (in the limit - without limiting the number of blades) horizontally axial wind turbine in which the blade may have a relative twist angle of sections in the range from 0 ° to 90 ° is considered as a prototype.

Disclosure of invention

According to the generally accepted technique, an aerodynamic model of a wind turbine is currently being used, the blades of which are in the regime of laminar flow around the air stream (with angles of attack of up to 5 ° in each section). The present invention considers a forced horizontal axial wind turbine, the blades of which in their butt part are located in the supercritical, at the angles of the inflow of the flow, otherwise, in the stall, flow around zone. This mode is achieved by reducing the angle of relative twist of the sections of the blade. By installing a slat (deflector) along the leading edge of the butt of such a blade, you can use the supercritical flow regime by laminating it.

The application of the method of forcing a horizontally axial wind turbine allows you to get an additional impulse in the direction of its rotation in order to increase the torque. This assumption can be justified by following the theory of the blade: the greater the deviation of the flow behind each section of the blade, the greater the driving force of the wind turbine as a whole.

The method of forcing wind turbines with a horizontal axis of rotation is supported by the determination from the Betz-Zhukovsky theory - the maximum efficiency of a wind turbine (Betz-Zhukovsky limit equal to 59.3%) is achieved when the airflow velocity behind the wind turbine becomes three times lower airflow in front of the wind turbine. The achievement of maximum approximation to the Betz-Zhukovsky limit is facilitated by the use of a slat (deflector): by the principle of its action, it rejects (slows down) the wind flow behind the turbine, more than any of the known devices used in the prototype.

Description of drawings

:FIG. 1 Increasing the efficiency of a wind power plant (wind turbine) through the use of a forced wind turbine on the example of the graph "power - wind"

:

- для выбранного прототипа ветровой турбины;

- for the selected prototype of a wind turbine;

- для форсированной ветровой турбины,

- for forced wind turbine,

Where:

- V ₀₁ - the initial wind speed of the forced wind turbine;

- V ₀₂ - the initial wind speed of the prototype of a wind turbine;

- V _nom1 - nominal wind speed of a forced wind turbine;

- V _nom2 - nominal wind speed of the prototype of a wind turbine;

- V _i - randomly selected wind speed in the range between V ₀₂ and V _nom1 .

A graphical interpretation of the expected effect is presented, consisting in an increase in the output power by ΔР at each moment of time, in relation to the prototype. Upon reaching the wind turbine rated output power R _nom , a program for limiting the angular velocity of rotation of the wind turbine enters into force, similar to the prototype.

FIG. 2 Variants of execution of a forced wind turbine blade, where:

1 - blade;

2 - slat;

β is the angle of relative twist of the sections of the blade and slat:

- для лопасти прототипа;

- for the prototype blade;

- для лопасти форсированной ветровой турбины;

- for a forced wind turbine blade;

- для предкрылка лопасти форсированной ветровой турбины.

- for the slat of the blade of the forced wind turbine.

I - embodiment of a forced wind turbine blade with a jumplike transition along the angles of relative twist of the blade sections from butt to feather.

II is an embodiment of a forced wind turbine blade with an integrated transition from butt to feather.

The shaded area is the feather of the blade.

In a forced wind turbine, the angle of relative torsion of the sections of the blades β by Δβ is less than that of the prototype.

Note to FIG. 2: The ratio OX / OL (where OX is the butt portion serviced by the slat, OL is the total length of the blade), the larger the angle of relative curl of the blade of the wind turbine of the selected prototype.

The implementation of the invention

The value of Δβ, by which the angle of relative torsion of the blade sections of the forced horizontal axial wind turbine should be reduced, can be determined by calculation or empirically, based on the analysis of the polar of the selected aerodynamic profile, with and without a slat, in order to bring the blade blade into the supercritical range angles of inflow of an air stream.

The blade of the forced horizontal axial wind turbine can be made in the variant with an integrated section of the transition from the butt to the feather, as well as in the variant with a jump-like transition in the angle of the relative twist of the sections from the butt to the feather.

In the particular case, the slat can be installed along the leading edge of the blade of the forced wind turbine along its entire length, to simplify production technology or for structural need. In this case, the OX / OL ratio is 1.

Claims (2)

1. The method of forcing a horizontal-axis wind turbine, characterized in that the forced wind turbine blade is brought out to the supercritical, by the angle of inflow of the air flow, flow mode by reducing the relative torsion angle of the cross-sections of the selected prototype blades with the installation of such a slat blade on the front edge . 2. The method of forcing a horizontal-axis wind turbine according to claim 1, characterized in that the butt portion of the blade, brought to the supercritical mode of flow around the air stream, has its own angle of relative twist of the sections; while the slat serving this section of the blade has its own angle of relative twist of the sections.

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