RU2095619C1 - Pressure-and-draft wind-electric power plant - Google Patents

Abstract

FIELD: wind-power engineering. SUBSTANCE: wind-electric power plant has windwheel, shaft, and generator; windwheel in installed in nozzle contained in sound- absorbing chamber of draft tube case with checker placed on its top and with control and safety valves; pressure chamber is located in bottom part and wind headers with blades are provided with external and internal curtains and placed downstream of chamber. EFFECT: improved design. 1 dwg

Description

 The invention relates to the field of wind energy and can be used as an installation for generating electricity using wind energy.

 Well-known wind power plants (hereinafter referred to as wind turbines), both existing and existing in projects, are based on one general principle: a wind receiving device, most often a wind wheel, picks up wind and transmits torque through a shaft and a transmission mechanism to a generator that generates electricity.

Since the energy density of the wind flow is very small, the designers, wanting to get more power, provide for huge sizes of wind wheels. For example, a wind turbine project with a capacity of 50 thousand kW has a rotating part of truly cyclic dimensions [1] A wind turbine project with a power of 0.6-5 MW (prototype) has a wind wheel diameter of 30–70 m [2]
It is obvious that wind turbines with wind wheels of this size will not be able to fully use the power of the air flow, because at a high speed of rotation, inertia forces increase, and against sharp gusts of wind, they are defenseless and unsafe for others. Great difficulties arise when orienting large wind turbines in the direction of the wind. Ecological harm of large wind turbines was also noted: when the blades rotate in the air stream, high-frequency air vibrations (ultrasound) occur leading to mass death of insects in the region where the wind turbines are located.

 The proposed design of a wind turbine of a pressure-exhaust action consists of a wind wheel, a shaft and a generator, the wind wheel being located in a nozzle enclosed in a sound-absorbing chamber of the exhaust pipe body, on which a nozzle is mounted on top and there are control and safety valves, and in the lower part of the exhaust pipe a pressure chamber, behind which there are wind receivers with guide vanes and with external and internal curtains.

 The drawing shows a section along the axis of the structure with a local view.

 This drawing shows the internal structure of the wind turbine and the arrows show the direction of the wind and the movement pattern of the pressure and exhaust air flow arising in the chimney.

 The main wind turbine of a pressure-exhaust action is an exhaust pipe 1, the inner surface of which is made of material with minimal roughness in order to reduce friction losses along the length of the pipe when the air flow is moving. The inner surface of the exhaust pipe 1 has a variable cross-section with smooth transitions and curves to reduce local resistance and eliminate turbulence in the air flow. The narrowest point of the nozzle 2 section in which the wind wheel 3 is located on the shaft 4 connecting it to the generator 5. The cavity resulting from the formation of the nozzle 2, enclosed between the outer and inner surfaces of the exhaust pipe 1, is a sound-absorbing chamber 6, the inner surface of which is covered with sound-absorbing material , because at high speeds of the air flow in the nozzle 2, acoustic phenomena occur.

 The upper part of the exhaust pipe 1 ends with the nozzle 7, there are also control and safety valves 8 that regulate the operation of the nozzle 7.

 In the lower part of the exhaust pipe 1 behind the nozzle 2 there are wind receivers 9, the working body of which are guide vanes 10, directing the wind flow into the pressure chamber 11. Movable curtains 12, external and internal, independently move on the outer and inner surfaces of the wind receiver 9.

 The operation of the nozzle 7 is based on the use of the energy of the air flow - wind, which, hitting the nozzle surface and flowing around it, creates a vacuum near most of its perimeter, which in turn creates a vacuum in the level of air outlet from the exhaust pipe 1. As a result, in the upper part exhaust pipe 1 is installed exhaust air flow directed upward, and air enters into it through the nozzle 2.

 The volume-mass of the extracted air is determined by the productivity of the nozzle 7, which in turn depends on its shape and the magnitude of the vacuum it creates for a given wind speed.

 The operation of the nozzle 7 is regulated by control and safety valves 8, which open at high wind speeds, which makes it possible for external air to flow through them into the exhaust pipe 1, as a result of which the air flow rate in the nozzle 2 will decrease.

 Wind receivers 9 in the lower part of the exhaust pipe 1, on the contrary, use positive wind pressure: guide blades 10 direct the incoming wind flow into the pressure chamber 11, in which the dynamic wind pressure is converted into static air pressure, as a result of which pressure pressure and, accordingly, pressure flow are created in the pressure chamber 11 air directed into the nozzle 2.

 The movable curtains 12, moving along the outer and inner surfaces of the wind receivers 9, overlap the leeward direction, and if necessary, the windward direction, thereby regulating the speed of the air flow in the nozzle 2, and the outer ones protect the wind receivers 9 from snow drifting in winter.

 Thus, these two independently arising air currents, when combined, create a pressure-exhaust air stream in the exhaust pipe 1, which moves a certain volume of air mass through the exhaust pipe 1.

 The volume of mass of transported air depends on the following factors: the diameter of the exhaust pipe 1, the magnitude of the pressure head in the pressure chamber 11 and the vacuum pressure in the nozzle 7, which in turn depend on the wind speed, the degree of restriction of the pressure-exhaust air flow by nozzle 2, and local resistance and the ratio of the diameters of the nozzle 2 and the wind wheel 3.

 Volume The mass of air transported per unit of time anywhere in the exhaust pipe 1 is constant and is determined by the product of the cross-sectional area of the exhaust pipe 1 at a given location and the velocity of the pressure and exhaust air flow at that location. Consequently, in the nozzle 2 the narrowest point of the cross section, the speed of the pressure and exhaust air flow will be maximum, its value will correspond to the volume of air mass transported per unit time through the exhaust pipe 1. Accordingly, the kinetic energy of the pressure and exhaust air flow in the nozzle 2 will reach its maximum, which determines the most favorable location of the wind wheel 3, which uses the kinetic energy of the pressure and exhaust air flow for its rotation. Torque from the wind wheel 3 through the shaft 4 and the transmission mechanism is transmitted to the generator 5, which generates electricity.

The advantages of the proposed design of wind turbines pressure and exhaust action are as follows:
combines the ability to use the energy of the wind flow from a large area and at the same time significantly reduce the size of the wind wheel;
independence of wind turbine operation from wind direction;
the ability to use wind energy from high altitudes, where the winds are stronger and more stable;
the wind wheel and generator are located inside the wind turbine housing, which is convenient for their maintenance and repair;
there is a constructive opportunity to create a simple and effective system of control and safety valves and movable shutters that clean the wind wheel from extremely high wind speeds;
since the wind wheel is located inside the wind turbine body, the direction of the air flow in it is constant and its speed is regulated, it becomes easier to localize the arising acoustic phenomena, which is important from an environmental point of view.

 According to the author, wind turbines of a pressure-exhaust action with a height of 200-250 m, a diameter of a chimney of 1-30 m, at a wind speed of 10 m / s will give power at the terminals of the generator of 2500 to 3000 kW. The diameter of the wind wheel 3 in this case will be 5 m, the diameter of the nozzle 2 6 m, the speed of the pressure and exhaust air flow in the nozzle 2 is about 100 m.

 In order for the wind turbine prototype to give the same power, it will require a wind wheel with a diameter of 140-160 m.

Claims (1)

 Pressure and exhaust wind power installation consisting of a wind wheel, a shaft and a generator, characterized in that the wind wheel is located in a nozzle enclosed in a sound-absorbing chamber of the exhaust pipe body, on which a nozzle is mounted on top and there are control and safety valves, and in the lower part there is a pressure chamber, behind which there are wind receivers with guide vanes, with external and internal curtains.