RU2465485C2 - Composite sail for high-altitude wind-driven power plant - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: sail equipped with areas for connection of power ropes is made of partial sails joined to each other by means of connection ropes. Partial sails are equipped with areas for connection of connection ropes having length exceeding linear dimensions of partial sails. For convenience of transportation, assembly and disassembly of the composite sail, partial sails and connection ropes may be equipped with devices for quick and convenient connection and disconnection, for instance, clasps and rings. Ropes that connect partial sails are equipped with areas for attachment of aerostats.

EFFECT: stable control of orientation and trajectory of sail movement by prevention of power ropes twisting and increase of linear dimensions of a sail with preservation of its surface area due to extension of connection channels to reduce cost and provide for convenience of assembly, disassembly, transportation and repair.

3 cl, 1 dwg

Description

The invention relates to high-altitude wind energy and can be used in high-altitude wind energy installations designed to convert wind energy at high altitude (more than 100 m above the Earth's surface) into electrical energy.

Known high-altitude wind power installations in which the wind power part, consisting of parallel-mounted sails, together with an electric generator rises above the surface of the earth with the help of aerodynamic forces [1]. The disadvantage of such devices is the complexity of their wind power parts.

Known high-altitude wind power installation containing two sails, each of which is divided into sections [2]. A disadvantage of the known sail is the complexity of its design.

Known high-altitude wind power installation in which the contour of the cross section of the sail of a rigid structure is similar to the contour of the cross section of the wing of an airplane [3]. The disadvantages of such a sail: high cost, large mass per unit area, the difficulty of controlling orientation in space.

For the prototype, a triangular-shaped sail was selected, which is part of a high-altitude wind power installation [4].

It contains a sail made in the form of a triangle, the sides of which are straight sections, power ropes connected to the sail and located on the drums connected to electric machines, and balloons through which the drums are connected to the sail using ropes.

Ropes are wound or wound from drums when the sail moves under the influence of wind. When the ropes are wound from the drums, electrical machines, mechanically connected to the drums, generate electrical energy that enters the network. When the ropes are wound on drums, electric machines consume energy from the network.

When the ropes are unwound from the drums, the orientation of the sail in space and the trajectory of its movement are selected by changing the ratios of the lengths of the ropes when changing the rotation speeds of electric machines (by changing the current strength in their windings) so that the maximum selection of wind energy takes place. When the sail returns to its former place, the orientation of the sail in space and the trajectory of its movement are chosen such by changing the lengths of the ropes so that the energy spent on overcoming the aerodynamic resistance to the movement of the sail, balloons and ropes is minimal during the return of the sail.

The functions of the ratios of the lengths of the ropes from time are obtained theoretically and corrected by experiments.

The energy consumption for the return of the sail will be significantly less than the energy that was obtained when the sail was removed from the drums.

The difference of these energies is sent to the consumer network in the form of a useful energy output.

Famous sail has the following disadvantages:

- if the flight height of the sail is many times greater than its linear dimensions, then controlling its orientation and trajectory by changing the rope lengths will be unstable, since small, percentage-wise, random changes in rope lengths, for example, due to turbulent air movements, will significantly affect the angle of attack of the sail;

- with a large ratio of height to the size of the sail, it is possible to twist the ropes as a result of vortex air movements, while control of the trajectory of the sail becomes impossible;

- if the sail is large, then there are difficulties in disassembling and assembling the installation, when folding the sail, its manufacture, packaging, transportation and repair;

- in each application, the optimal size and shape of the sails will be different, this increases the cost of their production due to the insufficient number of sails of each size for production with low cost.

The technical result of the invention is the provision of stable control of the orientation and trajectory of the sail by changing the ratios of the lengths of power cables, preventing twisting of the ropes, simplifying the assembly and disassembly of the sail, its packaging, transportation, repair and manufacturing, reducing the cost of its production.

The technical result is achieved by the fact that the sail of the wind power installation is made composite, that is, it consists of partial sails interconnected by newly introduced connecting ropes. This design of the sail has the following advantages over the well-known:

- by increasing the length of the connecting ropes, it is possible to increase the linear dimensions of the sail as a whole while maintaining its surface area equal to the sum of the areas of the partial sails. This increases the ratio of the linear dimensions of the sail to the height of its flight, which increases the stability of sail control and reduces the risk of twisting power ropes. If the speed of the sail has a component perpendicular to the direction of the wind, then energy is taken from the entire mass of air passing through the sail, therefore, with an increase in the linear dimensions of the sail, the power of the wind power installation can be increased without increasing the surface area of the sail;

- it becomes possible to assemble sails of any size and any shape from standard elements: partial sails and connecting ropes, which simplifies the assembly and disassembly of the sail, and therefore, the wind power installation as a whole, reduces the cost of production of sails, simplifies the manufacture, packaging, transportation and repair of sails , especially large sizes.

The invention is illustrated in the drawing, which shows a schematic representation of one of the possible configurations of the proposed sail.

The composite sail contains (Fig. 1) partial sails 1 interconnected by connecting ropes 2, and a partial sail 3 connected to sails 1 by connecting ropes 4. To the attachment points 5 of the sails 1 and to the attachment points of 7 ropes 2 and 4 can be attached balloons (not shown) for lifting the composite sail and ropes to the working height. The possibility of connecting balloons to ropes 2 and 4, as well as sail 3, which can cause the sag of the composite sail in the absence of wind, as a result of which the power ropes 6 get closer, the composite sail will fold and it will be difficult to straighten it.

When repairing a composite sail, during maintenance work, and also when deploying and curtailing a wind power installation on the ground, the ability to quickly and conveniently connect and disconnect connecting ropes and partial sails is required. For this, connecting ropes and partial sails can be equipped with special devices, for example, carbines and rings (not shown).

The proposed sail works as follows.

Under the action of the air running on the composite sail and the forces applied to the power ropes, the partial sails 1 acquire such angles of attack that forces are applied to the ropes 2 and 4, stretching the composite sail. Due to the presence of a central partial sail 3, the angles of attack of sails 1 and 3 will be approximately the same as if the sails were parts of a continuous sail with the linear dimensions of the composite sail, therefore, the composite sail will work in the same way as the prototype sail, therefore. The operation of the wind power plant with the proposed sail will not differ from that described on page 1 of the description of the operation of the wind power plant with the sail, which is the prototype, except that when dividing a solid sail into partial sails, the power of the installation increases due to an increase in the mass of moving air with which the sail comes into contact if the sail has a velocity component directed perpendicular to the direction of the wind.

The use of the proposed sail is especially effective when using the energy of the so-called jet air currents that run at heights of 8 to 15 kilometers above the Earth’s surface, having a specific power of more than 10 kW per 1 square meter of cross section.

References

1. US patent No. 4572962, 1986

2. A.S. USSR No. 1216416, 1986

3. US Patent No. 6523781, 2003

4. A.S. USSR No. 1590628, 1990

Claims (3)

1. Sail for high-altitude wind power installation, having places for connecting power ropes, characterized in that it is made of interconnected newly introduced connecting ropes of partial sails with places for connecting ropes, and the connecting ropes have a length exceeding the linear dimensions of the partial sails. 2. The sail according to claim 1, characterized in that the connecting ropes and partial sails are equipped with devices for quick and convenient attachment and detachment, for example carbines and rings. 3. The sail according to claim 1, characterized in that the ropes connecting the partial sails are provided with places for connecting balloons.