Patent Application
20120112481
The subject matter described herein relates generally to devices and methods for handling wind turbine blades, for example devices and methods that aid in the handling, transportation, storage, mounting, installation, and/or packaging of wind turbine blades. Wind turbine blades vary in size and shape, often with lengths of many tens of meters. After manufacture, wind turbine blades usually require transport to an installation site. Handling assemblies are used in the transportation and installation of wind turbine blades.
According to one aspect, a handling assembly for a wind turbine blade is provided, comprising a frame adapted to at least partially surround a section of the wind turbine blade, and an expandable cushion adapted to fill at least part of the space between the section of the wind turbine blade and the frame.
According to another aspect, a handling assembly for a wind turbine blade is provided, comprising a frame adapted to at least partially surround a section of the wind turbine blade, an inflatable cushion, and a port; the frame comprises openings adapted to allow the wind turbine blade to be positioned through the frame; the inflatable cushion comprises a chamber; the port is connected to the chamber to allow at least one of an influx and an outflux of a fluid; and the influx of fluid is associated with expansion of the cushion and casting of the cushion to at least a portion of the surface of the wind turbine blade.
According to another aspect, a method of handling a wind turbine blade is provided, comprising placing a handling assembly around a portion of the wind turbine blade, and expanding an expandable cushion between the handling assembly and the wind turbine blade to hold the wind turbine blade.
Further aspects, advantages and features of the present invention are apparent from the dependent claims, the description and the accompanying drawings.
A full and enabling disclosure including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures wherein:
Reference will now be made in detail to the various embodiments, one or more examples of which are illustrated in each figure. Each example is provided by way of explanation and is not meant as a limitation. For example, features illustrated or described as part of one embodiment can be used on or in conjunction with other embodiments to yield yet further embodiments. It is intended that the present disclosure includes such modifications and variations.
The embodiments described herein include a handling assembly for a wind turbine blade that provides a way to safely hold a blade, or fix the position of the blade. More specifically, according to many embodiments, a precise and determined enclosure safely fixes the blade so as to avoid damage to the blade. Alternatively or additionally, the handling assembly adapts to variable blade geometry, enabling an optimal pressure distribution over the surface of the blade, and compensating shape variations which may be due to variable blade geometry. The handling assembly helps to avoid damage to the blade during all types of handling, such as for example transportation, storage, mounting, lifting, installation, packaging, and the like.
Modern, lightweight wind turbine blades may be very sensitive to forces applied at fixing points at given locations of the profile. The blade skin may consist only of a few plies or layers with the exception of the upper and lower girder and/or the sparcap. The handling assembly helps to avoid damage to the blade during handling.
As used herein, the terms “blade,” “wind turbine blade,” and “rotor blade” are used synonymously. As used herein, the term “blade” is intended to be representative of any device that provides a reactive force when in motion relative to a surrounding fluid. As used herein, the term “wind turbine” is intended to be representative of any device that generates rotational energy from wind energy, and more specifically, converts kinetic energy of wind into mechanical energy. As used herein, the term “wind generator” is intended to be representative of any wind turbine that generates electrical power from rotational energy generated from wind energy, and more specifically, converts mechanical energy converted from kinetic energy of wind to electrical power. As used herein, the term “handling” is intended to be representative of activities such as for example transporting, preparing for storage, removing from storage, storing, mounting, lifting, installing, erecting, packaging, erecting, hoisting, and the like. Herein, holding assembly and handling assembly are used interchangeably. Herein: activation of the handling assembly is representative of action taken to hold a blade; deactivation is representative of action taken to release or loosen a blade; and preactivation is representative of action taken before activation of the handling assembly, which may be processes of preparing or enhancing the protective and/or gripping (e.g. holding) action of the cushion on the blade, frame, or both. Herein, a fluid may be a gas such as air. Herein holding, gripping, and fixing the blade are used interchangeably.
In one embodiment, rotor blades 22 have a length ranging from about 15 meters (m) to about 91 m. For example, other non-limiting examples of blade lengths include 10 m or less, 20 m, 37 m, or a length that is greater than 91 m.
The expandable cushion 190 is adapted to occupy at least part of the space between a section of the blade 22 that is at least partially surrounded by the frame 160 and the inside wall of the frame. In an embodiment, soft packing particles, a fluid, or a combination thereof are disposed within the expandable cushion 190. For example, soft packing particles such as polystyrene fill, polystyrene balls, polystyrene peanuts, starch-based particles, foam peanuts, or the like are used. The expandable cushion may also comprise a chamber, which may be one or more (e.g. all) of the parts of the cushion that is expandable (e.g. inflatable). The expandable cushion may also contract. The expandable cushion may be a hose or a pillow.
In an embodiment, the cushion is activated, deactivated, and preactivated by the flow of fluid. Activation is intended to be representative of preparing to handle the blade, wherein the blade is to be held in the handling assembly. An activated handling assembly is intended to be representative of a handling assembly that is holding a blade, preferably robustly and without causing damage to the blade. Deactivation is intended to be representative of loosening or releasing the handling assembly from the blade, e.g. for removal of a blade. Preactivation is intended to refer to processes of preparing or enhancing the protective and/or gripping action of the cushion on the blade, frame, or both. Preactivation may occur before or after activation, but preferably before activities such as transporting the blade held by the assembly with the blade, lifting the blade that is held by the handling assembly, moving the blade held by the handling assembly, and the like.
For example, a process of transporting a blade may be by: placing the blade in a handling assembly, optionally preactivating the handling assembly to protect or enhance the protection of the blade, activating the handling assembly to hold the blade, transporting the handling assembly and blade, deactivating the handling assembly to release the blade, and removing the blade from the handling assembly. The handling assembly aids, alternatively or additionally to the transport of blades, many other activities associated with the handling of wind turbine blades, for example storing and lifting.
In an embodiment, an influx of fluid into the expandable cushion causes the cushion to expand to fill at least part of the space between the section of the blade within the frame and the inside of the frame. For example, the cushion is activated by an influx of fluid into the cushion which causes the cushion to expand and adapt to the shape of at least part of the space between the blade and the inside of the frame. In other words, the expandable cushion is cast to the profile of at least a portion of a section of the wind turbine blade (e.g. a section of the blade partially or completely surrounded by the frame) by the influx of fluid. The blade is firmly but gently held by the handling assembly. The influx of fluid (e.g. through a port) into the cushion, and optionally the resulting pressurization of the cushion activates the handling assembly. The influx of fluid may be forced by the action of at least one pump or compressor. An activated cushion may be sealed by closing the port or the activated cushion may remain connected to a pump or compressor. A pressure-activated switch may maintain a fairly constant pressure in the cushion.
A precise and robust enclosure is required to safely handle blades, yet the blade surfaces are sensitive to forces applied to them. An activated cushion holds the blade firmly, with optimal load distribution over the surface of the blade. The activated cushion can ensure safe transport of the blade. An advantage of the handling assembly is that it is self-adapting to the actual geometry of the blade at the contacted position or positions. This enables optimal pressure distribution over the surface, provides a safe grip, and/or compensates for shape variations.
The cushion may be deactivated by the outflux of fluid from the cushion, which enables the separation of the handling assembly from the blade (and/or the removal, release, or loosening of the blade from the handling assembly). The outflux of fluid out of the cushion may be induced by opening the port, puncturing the cushion, or applying a negative relative pressure across the port (i.e. applying a relative vacuum). Outflux may be induced by opening a valve of the port or to the port.
In an embodiment, soft packing particles, fluid, or a combination thereof are disposed within the expandable cushion 190. For example, soft packing particles such as starch-based packing particles, polystyrene fill, polystyrene balls, or polystyrene peanuts are used. In an embodiment, the fluid is a gas such as air.
An influx of fluid into the expandable cushion 190, for example upon activation, causes the cushion to expand. Thus, toward the inside of the handling assembly, the expandable cushion 190 conforms to the shape of a section of the blade surrounded by the frame. In other words, the cushion is adapted to be cast to the profile of at least a portion of a section of the wind turbine blade by the influx of the fluid. The blade is held by the expanded (or activated) expandable cushion 190, which may be under pressure of fluid; and, toward the outside, the expandable cushion 190 conforms to at least part of the inner wall of the frame. The expanded cushion 190 holds the wind turbine blade 22.
In deactivating the handling assembly, the expandable cushion 190 can be unexpanded or depressurized by the outflux of fluid from the expandable cushion 190; and the blade is loosened or released from the grip of the handling assembly.
In
In an embodiment, one or more inner chambers compress due to the outflux of fluid from them, causing the one or more inner chambers 640, 660 to be cast to the profile of at least a portion of the blade, e.g. the leading and/or trailing edges. An advantage is that by casting one or more inner chambers 640, 660, the leading and/or trailing edges of the blade 22 are especially well protected from damage during handling.
Alternatively or additionally, preactivation is by the outflux of fluid from the leading and trailing edge cushion portions 640, 660 by the action of a vacuum, pump, or compressor. Following preactivation, the expandable cushion can be activated by expanding (e.g. inflating) the outer chamber 330 by the influx of fluid so that the outer chamber 330 expands to take up at least part of the space between the section of the blade surrounded by the frame and the frame, thus holding the blade. Therefore, a chamber may be compressed or deflated by the outflux of a fluid, for example to cast particles lying within the chamber; or expanded or inflated by an influx of fluid to hold the blade.
In an embodiment, an inner chamber is disposed toward the center of the frame from an outer chamber of the expandable cushion. Thus the inner chamber is adapted to be cast to the profile of at least a portion of the wind turbine blade (e.g. the portion of the section of the blade surrounded by the frame). For example, the inner chamber is cast around the blade 22 by a vacuum applied to the inner chamber. The outer chamber is subsequently expanded (e.g. inflated) to hold the blade.
Alternatively or additionally, a one inner chamber that is adapted to surround a portion of the blade 22, has soft packing particles disposed therein. After insertion of the blade, the one inner chamber may be preactivated by the outflux of fluid from the one inner chamber. Preactivation causes the particles to be cast to the profile or shape of the blade, which increases the cushioning of the blade, e.g. near at least one of the leading and trailing edges.
Other inner chambers are contemplated, additionally or alternatively to the leading and trailing edge chambers 640, 660. Other inner chambers may be “preactivated,” cast, or compressed, for example by the outflux of air from the inner chambers. One, two, three, four, or more inner chambers may be cast to the profile of at least a portion of the section of the blade. For example, a number (1, 2, 3, or 4, for example) of inner chambers with soft packing particles disposed therein may be cast to at least one of: the profile of at least a portion of the section of the blade surrounded by the frame, and at least a portion of the inside of the frame. Casting may be followed by expansion of an outer chamber, to hold the blade, and filling at least part of the space between the blade and the frame.
In yet another embodiment, soft packing particles (for example polystyrene particles) disposed within an inner chamber may be cast to the shape of at least a portion of the blade by the removal of a fluid such as gas, or more specifically air, from the inner chamber. An outer chamber, which is adapted to surround at least part of the blade, may be used to further cushion the blade and the cast the inner chamber. The outer chamber may also be expanded and/or pressurized to hold the blade.
Exemplary embodiments of systems and methods for handling wind turbine blades are described above in detail. The systems and methods are not limited to the specific embodiments described herein, but rather, components of the systems and/or steps of the methods may be utilized independently and separately from other components and/or steps described herein. Rather, the exemplary embodiment can be implemented and utilized in connection with many other rotor blade applications.
Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.
This written description uses examples to disclose embodiments, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. While various specific embodiments have been disclosed in the foregoing, those skilled in the art will recognize that the spirit and scope of the claims allows for equally effective modifications. Especially, mutually non-exclusive features of the embodiments described above may be combined with each other. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
