CN210460945U - Telescopic wind turbine blade - Google Patents

Abstract

The utility model relates to a scalable wind energy conversion system blade, include: the blade root telescopic part is a root cylindrical section of the wind turbine blade; the sealing partition plate is used for sealing the bottom end of the blade root telescopic part so as to enable the blade root telescopic part to form a piston form; the blade root telescopic part is assembled in one end of the air cylinder barrel; the pressure regulating piston is arranged at the other end of the inner cavity wall of the air cylinder barrel, so that a sealing space is enclosed by the sealing end part of the blade root telescopic part and the pressure regulating piston in the air cylinder barrel; and the driving mechanism is used for driving the pressure regulating piston to extend and retract in the other end of the air cylinder barrel so as to regulate the pressure in the air cylinder barrel, and the blades of the wind turbine stretch and retract in the rotating process. By adopting the structure, the blades can be stretched out and drawn back along with the rotation period in a limited stroke, so that the wind catching load is limited, the blade load is balanced, and the alternating load is reduced.

Description

Telescopic wind turbine blade

Technical Field

The utility model belongs to the technical field of wind power generation technique and specifically relates to a scalable wind energy conversion system blade is related to.

Background

With the increasing maturity and the gradually clear cost of wind turbine design and manufacturing technologies applied in scale, the blade as a large part of the wind turbine plays an important role in energy conversion and control, and the manufacturing cost is about 15-20% of the cost of the whole wind turbine, and the wind turbine as a renewable clean energy source only needs to utilize the kinetic energy of wind and does not need fuel consumption in the whole life cycle, so the cost of the wind turbine mainly comprises the following three aspects: manufacturing, installing and debugging, and operating and maintaining. Improving economics can begin with two technological paths, one is the elaborate design that reduces the cost of the major components, and the other is the extension of the expected operating life of the critical components. The latter is the main way to improve the existing blades.

In order to strive for longer service life, more accurate static load and fatigue load need to be mastered in the design of the wind turbine blade. The design life of the wind turbine is more than 20 years, taking a 2MW unit as an example, the blade of the wind turbine needs to rotate by about 10 in the whole life cycle⁸The order of the week is subjected to the effects of alternating gravity, wind shear, yaw error, shaft warping, tower interference, turbulence every week. Therefore, in the design of wind turbine blades, the fatigue load is a very important factor, and the importance degree can be compared with the limit load caused by the limit wind speed. The control system for a wind turbine in the horizontal axis is generally based on active control of sensors, controllers and actuators. The sensor measures wind speed and direction, impeller rotating speed, output power or torque; the actuating mechanism adjusts the torque, the pitch angle, the yaw angle and the like of the motor; the controller is connected with the two and controls the twoThe control algorithm drives the actuating mechanism to carry out necessary reaction on the result measured by the sensor so as to achieve the control targets of optimal power or load and the like.

However, for blade alternating loads due to wind shear induction, the unified pitch based system does not control the load fluctuations well. Therefore, a blade root bending moment sensor is introduced into some strengthened control systems, and an alternating load caused by wind shearing is reduced by adopting a blade independent pitch control method. In recent years, real-time inflow velocity measurement technologies, such as laser wind-finding radar, acoustic wind-finding radar and the like, are also introduced into the independent pitch system. The independent pitch control method can effectively reduce the alternating load, but the corresponding cost is higher, because the pitch frequency is increased, and the requirements of a sensor and an actuating mechanism are greatly improved. It is therefore desirable to develop a reliable and cost effective method of suppressing alternating loads.

The patent refers to the field of 'wind motors'. According to the variable-pitch blade, the local variable pitch of the variable-pitch blade can be realized by controlling the blades of different sections to respectively change the pitch angle, so that the variable-pitch blade can obtain the highest wind energy absorption efficiency under the conditions of different wind speeds and rotating speeds, and the problem that the integral variable-pitch blade cannot obtain the optimal wind energy absorption efficiency under different wind speeds and rotating speeds is solved.

However, the blades mentioned in the technology need to be manually replaced according to the weather conditions, and meanwhile, only one blade can be used within a period of time, and the blade does not have the function of stretching and contracting in real time according to the airflow conditions to reduce alternating loads.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a scalable wind energy conversion system blade, it relies on self gravity and external force to realize blade length change.

In order to achieve the above object, the utility model provides a scalable wind energy conversion system blade, include: the blade root telescopic part is a cylindrical section of the root of the wind turbine blade; the sealing partition plate is used for sealing the bottom end of the blade root telescopic part so as to enable the blade root telescopic part to form a piston form, the position of the sealing partition plate can be at the end part of the blade root or slightly close to the inner part, and the shape of the sealing partition plate can be a flat plate or a curved surface according to the requirements of control and structural strength; the blade root telescopic part is assembled in one end of the air cylinder barrel; the pressure regulating piston is arranged at the other end of the inner cavity wall of the air cylinder barrel, so that a sealing space is formed by the sealing end part of the blade root telescopic part and the pressure regulating piston in the air cylinder barrel; and the driving mechanism is used for driving the pressure regulating piston to extend and retract in the other end of the air cylinder barrel so as to regulate the pressure in the air cylinder barrel, and the blade of the wind turbine drives the blade root telescopic part to extend and retract in the inner cavity of the air cylinder barrel under the action of self gravity and the air pressure in the air cylinder barrel in the rotating process so as to regulate the length of the blade of the wind turbine.

Optionally or preferably, the side surface of the air cylinder barrel and the side surface of the blade root telescopic part are both provided with frustum structures, the frustum structures of the air cylinder barrel and the blade root telescopic part are opposite, and the blade root telescopic part can freely slide along the side surface of the air cylinder barrel; the frustum structure of the air cylinder barrel and the frustum structure of the blade root telescopic part are used for preventing the blade root telescopic part from falling off from the air cylinder barrel.

Optionally or preferably, the air cylinder and the blade root telescopic part are hermetically assembled through a piston ring group; the piston ring group is positioned in a groove on the side surface of the air cylinder barrel or the side surface of the blade root telescopic part; the groove on the side surface of the air cylinder barrel is positioned above the frustum of the air cylinder barrel; and the groove on the side surface of the blade root telescopic part is positioned below the frustum of the blade root telescopic part.

The utility model provides a beneficial effect that technical scheme brought is: the length of the blade is changed periodically along with the periodic rotation of the blade, so that the wind catching capacity is increased by a large wind sweeping area in a sweeping area with low wind speed, and the wind catching load is limited by a small wind sweeping area in a sweeping area with high wind speed, thereby achieving the effect of load balancing.

Drawings

Fig. 1 is a cross-sectional view of a retractable wind turbine blade provided by the present invention.

Wherein: A. a blade; B. a blade root extension portion; C. a pressure regulating piston; D. an air cylinder barrel; E. a drive mechanism.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the invention.

The terms "mounted," "connected," and "coupled" are to be construed broadly and may, for example, be fixedly coupled, detachably coupled, or integrally coupled; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the creation of the present invention can be understood by those of ordinary skill in the art through specific situations.

The present invention will be described in further detail with reference to specific examples, but the present invention is not limited thereto.

As shown in fig. 1, the embodiment of the utility model provides a retractable wind turbine blade, because blade A is cylindric with air cylinder D, the cross-sectional view has the symmetry along perpendicular axis. The telescopic wind turbine blade comprises an air cylinder barrel D, wherein two ends of the air cylinder barrel D are open and cylindrical, a blade root telescopic part B of the cylindrical wind turbine is arranged on the inner side of the air cylinder barrel D, and the blade root telescopic part B and the air cylinder barrel D can freely slide relatively. The bottom of the telescopic part of the blade root is provided with a sealing clapboard, the sealing clapboard and the lower part of the air cylinder D form a sealing space, the position of the sealing clapboard can be at the end part of the blade root or slightly inside, and the shape of the sealing clapboard can be a flat plate or a curved surface according to the requirements of control and structural strength. In a preferred embodiment, the air cylinder D is provided with a frustum structure at the upper part thereof, and the blade root extension part B is provided with a frustum structure opposite to the air cylinder D.

The blade root telescopic part is assembled in one end of the air cylinder barrel. The pressure regulating piston C is arranged at the other end of the inner cavity wall of the air cylinder barrel, so that a sealing space is enclosed by the sealing end part of the blade root telescopic part and the pressure regulating piston in the air cylinder barrel. The driving mechanism E is used for driving the pressure regulating piston to extend and retract in the other end of the air cylinder barrel so as to regulate the pressure in the air cylinder barrel, and when the wind turbine works, the blade of the wind turbine drives the blade root telescopic part to extend and retract in the inner cavity of the air cylinder barrel under the action of self gravity and the air pressure in the air cylinder barrel in the rotating process so as to regulate the length of the blade of the wind turbine.

The relative positions of the blade A and the air cylinder D are periodically changed along with the rotation of the air cylinder barrel around the axis of the wind turbine, the rotating plane is vertical to the ground, when the blade A rotates to the upper part of the wind turbine, the air cylinder barrel D is positioned below the blade A, the blade A moves towards the direction of the air cylinder barrel D under the action of the self weight, and a sealing space formed by a sealing partition plate of the blade root telescopic part B and the air cylinder barrel D is compressed; when the blade A rotates to the lower part of the wind turbine, the air cylinder barrel D is positioned above the blade A, the blade A deviates from the direction of the air cylinder barrel due to self gravity, and meanwhile, compressed air between the sealing partition plate and the air cylinder barrel D has the tendency of outward expansion, so that a sealing space formed by the sealing partition plate arranged on the blade root telescopic part B and the air cylinder barrel D is stretched, the working length of the blade A is extended, and the wind sweeping area is increased. The length of the blade A is changed periodically along with the periodic rotation of the blade A, so that the wind catching capacity is increased by a large wind sweeping area in a sweeping area with low wind speed, and the wind catching load is limited by a small wind sweeping area in a sweeping area with high wind speed, thereby achieving the effect of load balancing.

According to the scheme, the blade root of a common blade can be improved to form a shape close to a cylinder, the end part of the blade root is sealed, the rigidity and the wear resistance of the blade root are improved, the roughness is reduced, an air cylinder is adopted to connect a blade flange or replace a flange (a special-shaped flange) to connect the blade and a hub, and sealing elements such as a piston ring and the like are used for strengthening sealing between the air cylinder and the blade root. Meanwhile, a pressure regulating piston and a corresponding control mechanism such as a hydraulic cylinder, a turbine worm, a gear rack and the like are added for flexible control.

In the rotation process of the blade, the blade can stretch out and draw back in a limited stroke under the action of the gravity of the blade and the difference between the air pressure inside and outside the cylinder barrel, so that the effect of increasing wind catching capacity by having a larger wind sweeping area in a sweeping area with lower wind speed and limiting wind catching load by having a smaller wind sweeping area in a sweeping area with higher wind speed is achieved, and the effect of load balancing is achieved.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. The use of "first," "second," and similar terms in the description and claims do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. Also, the use of the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect.

The above description is only exemplary of the present invention and should not be construed as limiting the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (3)

1. A retractable wind turbine blade, comprising:

the blade root telescopic part is a section of cylindrical section of the root of the wind turbine blade;

a sealing diaphragm for closing the bottom end of the blade root extension so that the blade root extension forms a piston form;

the blade root telescopic part is assembled in one end of the air cylinder barrel;

the pressure regulating piston is arranged at the other end of the inner cavity wall of the air cylinder barrel, so that a sealing space is formed by the sealing end part of the blade root telescopic part and the pressure regulating piston in the air cylinder barrel; and

and the driving mechanism is used for driving the pressure regulating piston to extend and retract in the other end of the air cylinder barrel so as to regulate the pressure in the air cylinder barrel, and the blade of the wind turbine drives the blade root telescopic part to extend and retract in the inner cavity of the air cylinder barrel under the action of self gravity and the air pressure in the air cylinder barrel in the rotating process so as to regulate the length of the blade of the wind turbine.

2. The retractable wind turbine blade as claimed in claim 1, wherein the side of the air cylinder barrel and the side of the blade root retractable part are both provided with frustum structures, the frustum structures of the air cylinder barrel and the blade root retractable part are opposite to each other, and the blade root retractable part can freely slide along the side of the air cylinder barrel; the frustum structure of the air cylinder barrel and the frustum structure of the blade root telescopic part are used for preventing the blade root telescopic part from falling out of the air cylinder barrel.

3. The retractable wind turbine blade as claimed in claim 1, wherein the hollow cylinder barrel and the blade root retractable part are hermetically assembled by a piston ring set; the piston ring group is positioned in a groove on the side surface of the air cylinder barrel or the side surface of the blade root telescopic part; the groove on the side surface of the air cylinder barrel is positioned above the frustum of the air cylinder barrel; the groove on the side face of the blade root telescopic part is positioned below the frustum of the blade root telescopic part.

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