FLANGE CONNECTION FOR A WIND TURBINE AND METHOD OF CONNECTING PARTS OF A WIND TURBINE
A flange connection for two tower sections of a wind energy system is described. The wind energy system includes a first flange including a first portion and a second portion, and a second flange including a first portion and a second portion. The wind energy system further includes a first connecting element having substantially the shape of at least a segment of a ring and a second connecting element having substantially the shape of at least a segment of a ring. The first connecting element and the second connecting element are adapted for being connected to each other and are adapted for connecting the first portion of the first flange with the first portion of the second flange.
The subject matter described herein relates generally to methods and systems for flange connections, and more particularly, to methods and systems for flange connections in a wind turbine.
At least some known wind turbines include a tower and a nacelle mounted on the tower. A rotor is rotatable mounted to the nacelle and is coupled to a generator by a shaft. A plurality of blades extends from the rotor. The blades are oriented such that wind passing over the blades turns the rotor and rotates the shaft, thereby driving the generator to generate electricity.
Wind turbines are placed at locations providing high wind amounts. However, as the conditions are often rough at the wind turbine locations and as the wind turbines become larger, the tower of the wind turbine is subject to heavy threes. Thus, the wind turbine tower is constructed in a stable way, including an appropriate diameter for carrying the nacelle and withstanding the rough conditions.
Due to the increasing size of the wind turbine tower, the tower is segmented in several parts so as to facilitate the transport of the wind, turbine tower to the wind turbine location. The several parts of the wind turbine tower are mounted and connected to each other at the wind turbine location.
When several parts of a wind turbine tower are provided and mounted, the parts are connected by flange connections in order to ensure the required strength of the connections. However, the strong flange connections of the wind turbine tower parts are often space consuming, increase the diameter of the tower segment and consequently the transport costs.
Thus, there is a desire to provide a strong flange connection for wind turbine parts, while taking into account the transport costs at the same time.
BRIEF DESCRIPTION OF THE INVENTIONIn one aspect, a connection for a wind energy system is provided. Typically, the wind energy system includes a first flange including a first portion and a second portion, and a second flange including a first portion and a second portion. The wind energy system may further include a first connecting element having substantially the shape of at least a segment of a ring and a second connecting element having substantially the shape of at least a segment of a ring. The first connecting element and the second connecting element may be adapted for being connected to each other and may be adapted for connecting the first portion of the first flange with the first portion of the second flange.
In another aspect, a wind energy system is provided. Typically, the wind energy system includes a nacelle including a rotor; a tower carrying the nacelle; a flange on at least a part of the tower, wherein the flange includes a first portion and a second portion extending in a substantially horizontal direction. Further the wind energy system includes a connecting element having substantially the shape of at least a segment of a ring, wherein the connecting element is adapted for being placed on the first portion of the flange and is adapted for securing at least a part of the tower.
In yet another aspect, a tower section of a wind energy system is provided. The tower section may include a flange on at least a part of the tower section. Typically, the flange includes a first portion and a second portion extending in a substantially horizontal direction. Further, the tower section may include a connecting element having substantially the shape of at least a segment of a ring, wherein the connecting element is placed on the first portion of the flange and is adapted for securing the tower section.
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 wind turbine system that includes a flange connection having the required strength, whilst at the same time saving transport and manufacturing costs. More specifically, the flange assembly as described herein provides a way to assemble a flange (such as a T-flange) in order to overcome transportation limits. Further, the flanges according to embodiments described herein are easy to transport as well as easy to assemble by providing multiple split parts across the circumference.
As used herein, the term flange is intended to be representative of a connecting element for connecting parts. The parts to he connected may be in the shape of a tube, a ring, a substantially circular device or the like. According to some embodiments, the parts to be connected may include non circular shapes like triangular, pentagonal or multifaceted shapes. The connecting element may he adapted to be used in wind energy systems, such as for connecting parts of the tower of a wind energy system. According to some embodiments, the flange may be used to connect parts of a tower. Typically, a flange connection as used herein may refer to a connection including a flange. For instance, a flange connection may include two flanges to be connected to each other. According to some embodiments, the flange connection may include two flanges to be connected with each other and further connecting components or elements. The flange as described herein may be used in wind energy systems, but may also be applicable for other technologies using flanges.
The term “at least a segment of a ring” as used herein is intended to be representative of a ring-like device, which may be a whole ring or a segment of a ring. Typically, the segment of the ring may include a defined angle, which may be dependent on the respective application. For instance, the angle of a ring segment may be about 5°, about 30°, about 300° or any value between, above or below these examples. According to some embodiments, having “substantially” the shape of a ring means that a certain deviation from the ring-shape may be provided. For instance, the device having “substantially a ring shape” may not have a circular ring shape, but another shape, such as an elliptic shape, a partly circular shape or the like.
Typically, the term “connecting” in this context refers to fastening one or more parts to one or more different parts. For instance, connecting two parts may refer to fastening or fixing these two parts to each other. According to some embodiments, further components, such as bolts or screws, may be used for connecting parts together.
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 the 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.
Rotor blades 22 are spaced about hub 20 to facilitate rotating rotor 18 to enable kinetic energy to be transferred from the wind into usable mechanical energy, and subsequently, electrical energy. Rotor blades 22 are mated to hub 20 by coupling a blade root portion 24 to hub 20 at a plurality of load transfer regions 26. Load transfer regions 26 have a hub load transfer region and a blade load transfer region (both not shown in
In one embodiment, rotor blades 22 have a length ranging from about 15 meters (m) to about 91 m. Alternatively, rotor blades 22 may have any suitable length that enables wind turbine 10 to function as described herein. For example, other non-limiting examples of blade lengths include 10 in or less, 20 in, 37 in, or a length that is greater than 91 m. As wind strikes rotor blades 22 from a direction 28, rotor 18 is rotated about an axis of rotation 30. As rotor blades 22 are rotated and subjected to centrifugal forces, rotor blades 22 are also subjected to various forces and moments. As such, rotor blades 22 may deflect and/or rotate from a neutral, or non-deflected, position to a deflected position.
In the exemplary embodiment, control system 36 is shown as being centralized within nacelle 16, however, control system 36 may be a distributed system throughout wind turbine 10, on support system 14, within a wind farm, and/or at a remote control center. Control system 36 includes a processor 40 configured to perform the methods and/or steps described herein. Further, many of the other components described herein include a processor. As used herein, the term “processor” is not limited to integrated circuits referred to in the art as a computer, but broadly refers to a controller, a microcontroller, a microcomputer, a programmable logic controller (PLC), an application specific integrated circuit, and other programmable circuits, and these terms are used interchangeably herein. It should be understood that a processor and/or a control system can also include memory, input channels, and/or output channels.
In the embodiments described herein, memory may include, without limitation, a computer-readable medium, such as a random access memory (RAM), and a computer-readable non-volatile medium, such as flash memory Alternatively, a floppy disk, a compact disc-read only memory (CD-ROM), a magneto-optical disk (MOD), and/or a digital versatile disc (DAM) may also be used. Also, in the embodiments described herein, input channels include, without limitation, sensors and/or computer peripherals associated with an operator interface, such as a mouse and a keyboard. Further, in the exemplary embodiment, output channels may include, without limitation, a control device, an operator interface monitor and/or a display.
Processors described herein process information transmitted flora a plurality of electrical and electronic devices that may include, without limitation, sensors, actuators, compressors, control systems, and/or monitoring devices. Such processors may be physically located in, for example, a control system, a sensor, a monitoring device, a desktop computer, a laptop computer, a programmable logic controller (PLC) cabinet, and/or a distributed control system (DCS) cabinet. RAM and storage devices store and transfer information and instructions to be executed by the processor(s). RAM and storage devices can also be used to store and provide temporary variables, static (i.e., non-changing) information and instructions, or other intermediate information to the processors during execution of instructions by the processor(s). Instructions that are executed may include, without limitation, wind turbine control system control commands. The execution of sequences of instructions is not limited to any specific combination of hardware circuitry and software instructions.
Nacelle 16 also includes a yaw drive mechanism 56 that may be used to rotate nacelle 16 and hub 20 on yaw axis 38 (shown in
According to some embodiments, the tower of a wind turbine may be divided in several parts so as to facilitate the transport and mounting of the wind turbine tower. For instance, the parts or sections being mounted to form the wind enemy tower may have a diameter of about 4 in (such as 4.3 m) and a height in a range of about 10 m to about 25 m (such as in a range from about 12 m to about 24 m). The parts of a wind turbine tower may be connected by a flange connection. Typically, T-flange constructions are proved to be more effective arrangements compared to L-flange arrangements. T-flanges are able to transfer larger moments than L-flanges, which gives a benefit for larger MW rating machines. However, T-flange assemblies providing a larger outer diameter than L-flanges suffer from a drawback concerning transportation costs when used in large wind turbines. A limitation of existing L-flange design is, for instance, the number of bolts which is limited due to space constraints. With increasing hub height and MW rating of the wind turbine, the tower base loads tend to increase continuously A single row of bolts, as for instance used in L-flanges, is not adequate for high tower base moments, which is proved by analysis. It has also been found that having an L-flange configuration with two rows of bolts is inefficient and improves the moment transfer capacity of the joint only marginally. Also, an increasing number of bolts, an increasing size of the bolts and/or an increasing width of the flange cannot deliver the desired properties. Furthermore, increasing the tower base diameter by dividing the tower base in the circumferential direction in order to meet the transportation limits causes undesired side-effects. When compared with the L-flange design, the T-flange design has a high bearing moment due to the equal sharing of loads by both rows of bolts, but transportation limits often prevent an integral T-joint from being used.
The flange assembly according to embodiments described herein concerns connecting tower sections using collar flanges. In embodiments of the invention, the existing L-flanges are provided with a collar of small width on the outer surface to provide a mounting interface for a collar flange. Collar flanges having two halves may be mounted on the respective collar of the tower sections. Typically, the flanges of the flange assembly described herein may be mounted to a tower section (such as welded to a tower section) or may be a part of the tower section.
Typically, in a flange assembly according to embodiments described herein, a collar flange is assembled to an L-flange, whereby an outer row of bolts provided at the collar flange provide the required clamping force. Typically, the outer row of bolts of the collar flange together with the inner row of bolts of the L-flange act as a T-flange. The joint connection is able to transfer high bending moments. Typically, joints for larger MW machines allow designing within transportation limits. The flange connection according to embodiments described herein help in facilitating the transport and assembly of the wind turbine parts. Typically, an outer row of bolts are easily accessible for maintenance since the proposed joint is a tower base ring (TBR) to the tower door section interface.
The term “substantially” as used herein may mean that there may be a certain deviation from the characteristic denoted with “substantially.” For instance, the term “substantially horizontal” refers to a direction which may have certain deviations from the exact horizontal position, such as a deviation of about 1° to 15° of the horizontal direction. According to a further example, the term “having substantially an L-shape” may refer to the shape of an element in a cross-sectional view. For instance, an element may have substantially the form of an L, when two parts of the element are present having a certain angle between them. Typically, the angle between the parts of the element may be between 70° and 100°. Further, according to one embodiment, one of the parts of the element denoted as having an L-shape may be shorter than the other. According to yet a further example, the term “having substantially the shape of a plate” may refer to a case, where an element is formed so as to he planar. Typically, the plate may deviate from the planar arrangement to a certain extent.
As can be seen in
According to some embodiments, which can be combined with other embodiments described herein, the first connecting element and the second connecting element may be adapted to he connected to each other. Typically, the first connecting element and the second connecting element may be adapted to connect the first portion of the first flange to the first portion of the second flange.
Typically, the first portion of a flange as described herein may also be referred to as a collar of the flange. Further, according to some embodiments, the first and the second connecting element as described herein may also be denoted as collar flanges.
Typically, the flange connection according to embodiments described herein is assembled so as to obey transportation limits. According to some embodiments, an L-flange is assembled into a T-flange by providing a collar extension to the L-flange, wherein the extension of the collar in the horizontal direction is smaller than the extension of a T-flange in the respective direction. For instance, the extension of the collar of the flange in the horizontal direction may typically range from about 50 mm to about 200 mm, more typically from about 70 mm to about 150 mm, and even more typically from about 90 mm to about 110 mm. According to one embodiment, which can be combined with other embodiments described herein, the extension of the collar of the flange in the horizontal direction may be about 100 mm.
According to some embodiments, the connecting elements, such as collar flanges described herein, may be made from a substantially rigid or non-elastic material, such as steel, aluminum and like metallic materials, but also composite materials or the like.
In an embodiment described herein, the first and/or second connecting element (such as a collar flanges) may be split into multiple flat plates to reduce manufacturing costs. This could be achieved by either using one flat plate as one of the connecting elements and extending the other connecting element (as described in detail referring to FIG, 4), or using two flat plates and one circular ring to form an integral flange (as described in detail referring to
Typically, the first and second connecting element 430 and 440 are adapted to be connected to each other. In the example shown in
Typically, two of the three connecting elements shown n
According to some embodiments, the flanges of the flange connection may be connected at the second portion of the flanges too. As can exemplarily be seen in
Typically bolted joints may be used to connect the connecting elements (such as collar flanges) according to embodiments described herein, to provide the required clamping force for integrating the joint.
In another embodiment, the configuration can also be applied to an internal tower flange if additional space is required inside the tower shell, for instance in the case, where the down tower electrical system is assembled within the tower in pre-assembled power modules (PPM). According to some embodiments, which can be combined with other embodiments described herein, the second portion of the first and the second flange may be connected by connecting elements, the connecting elements being similar to those used for connecting the first portions of the flanges. Such an example is shown in
In the embodiment shown in
According to some embodiments, the flange connection described herein may also be denoted as a bore-free flange connection or at least a partly bore-free flange connections. For instance, the first portion extending outwardly in the radial direction does not provide bores for fastening the flange, as can exemplarily be seen in
According to some embodiments, the connecting element 870 is divided in more than one part in circumferential direction, which is shown and explained in detail with respect to
Generally, the ratio between the extension of the first portion in the horizontal direction and the second portion in the horizontal direction may be about 1:1, 1:2, or up to 1:5. For instance, the embodiments shown in
In
In addition, also the collar of a flange, such as the first or second portion of a flange may be provided with a slope for improving the clamping force between the first or second portion of a flange and the connecting element.
Typically, the angle provided on one or more components of the flange connection or flange assembly for forming the tapered shape or a slope may be between about 0.5° to about 7°, more typically between about 1° and 5°, and even more typically between about 2° and 4°. According to one embodiment, which can be combined with other embodiments described herein, the angle for forming the tapered shape may be about 2°.
According to some embodiments, both the flange and the connecting element may provide a slope in order to improve the clamping force between them. It may also be possible to provide the first and/or second portions of the flange with a slope. Typically, either component of a flange connection as described herein may be equipped with a slope on a contacting face for improving the clamping force. In particular, the embodiments described with respect to
According to some embodiments, which can be combined with other embodiments described herein, the connecting elements (such as the collar flange) can be split into multiple numbers of parts to make it as a split flange for easy connection and transportation. In that way, collar flanges can typically be transported in multiple parts and are within transportation limits. The collar flange can be assembled at the construction site of the wind turbine with minimum equipment.
For instance,
In
Typically, assembled together the segments build a whole ring. According to other embodiments, the segments cover only a part of a 360° ring.
An example of an arrangement, wherein the connecting element covers only a part of the circumference of the wind energy tower, is shown in
Typically, the T-flange 1020 is only partly provided around the circumference of the tower 1010. For instance, the T-flange 1010 may have flattened portions 1030. The flattened portions 1030 may help complying with transportation or packaging limits. According to some embodiments, the flattened portions 1030 ensure that the arrangement 1000 does not exceed a shipping limit. The height 1040 of the arrangement 1000 is thus adapted to comply with shipping limits. However, in order to provide the required strength, although the T-flange covers only a part of the whole circumference of the tower 1010, connecting element 1050 and 1055 may be provided. Typically, the connecting elements 1050, 1055 may be connecting elements as described above and may be provided on a first portion 1060 of the T-flange, such as a collar 1060. The connecting elements 1050, 1055 are exemplarily shown with a curved shape at one side, however, it is to be understood that the shape of the connecting element may also be flat shaped without curvature.
The embodiment shown in
According to some embodiments, the described flange assemblies may also be used to connect a wind energy tower to the ground. In this case, one flange and one connecting element may be used to fix the tower to respective components in the ground.
Typically, embodiments described herein refer to a method for connecting parts of a wind energy system.
According to some embodiments, in block 1110, a first connecting element is placed on the first portion of the first flange. Typically, the first connecting element has substantially the shape of at least a segment of a ring. In block 1120, a second connecting element is placed on the first portion of the second flange.
Typically the first connecting element and the second connecting element may have a ring-like shape or be a segment of a ring-like shape. Further, the first connecting element may be provided in several parts. For instance, in the case where the connecting element is provided as a segment of a ring-like shape, the connecting element may be described as including more than one segment.
Block 1130 refers to connecting the first connecting element and the second connecting element to connect the first portion of the first flange with the first portion of the second flange. Typically, fastening devices may be used to connect the first and second connecting element with each other.
The method according to embodiments described herein may be used for operating a wind energy system as described above. Also, the method may be used to connect parts of a wind energy system using the above described examples of flange connections and assemblies. For instance, the method for operating a wind energy system according to embodiments described herein may further include providing a third connecting element, which may help connecting the first and the second connecting elements.
Typically, the first and the second flanges may additionally be connected through the second portions of the flanges. For instance, fastening devices, such as screws, may be used to connect the second portion of the first flange with the second portion of the second flange.
According to sonic embodiments, the second portion of the first flange may be connected with the second portion of the second flange using further connecting elements, such as a third and fourth connecting element. Typically, the third and fourth connecting elements for connecting the second portion of the first flange with the second portion of the second flange may be of the same design as the first and second connecting elements. In particular, they may be designed as described above with respect to
Embodiments described herein are also applicable for a reverse taper tower door section keeping the collar within transportation limits.
The above-described systems and methods facilitate the transportation and assembly of wind turbine parts or components. More specifically, the flange connection according to embodiments described above allows for complying with transportation limits, thereby decreasing costs for transportation and, at the same time, provides a reliable and exact connection of wind turbine parts, such as parts of a wind turbine tower.
Exemplary embodiments of systems and methods for a flange connection and a flange assembly 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. For example, the flange connection described herein may be used in further applications, other than just those concerning connecting parts of a wind turbine, and are not limited to practice with only the wind turbine systems as 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 the invention, 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.
Claims
1. A flange connection for two tower sections of a wind energy system, comprising:
- a) a first flange including a first portion and a second portion;
- b) a second flange including a first portion and a second portion; and,
- c) a first connecting element having substantially the shape of at least a segment of a ring and a second connecting element having substantially the shape of at least a segment of a ring, wherein the first connecting element and the second connecting element are adapted for being connected to each other and are adapted for connecting the first portion of the first flange with the first portion of the second flange.
2. The flange connection according to claim 1, wherein the first portion and the second portion of the first and the second flange extend in a substantially horizontal direction.
3. The flange connection according to claim 1, wherein the second portion of the first flange and the second portion of the second flange are adapted to be connected to each other.
4. The flange connection according to claim 1, further comprising a third connecting element adapted for connecting the first connecting element and the second connecting element.
5. The flange connection according to claim 1, wherein the first connecting element s adapted for being in contact with the first portion of the first flange and the second connecting element is adapted for being in contact with the first portion of the second flange in a mounted condition.
6. The flange connection according to claim 1, wherein at least one of the group consisting of the first portion of the first flange, the first portion of the second flange, the first connecting element and the second connecting element has a tapered shape.
7. The flange connection according to claim 1, wherein at least one of the first and the second connecting elements substantially have an L-shape.
8. The flange connection according to claim 1, wherein the second portion of the first flange and the second portion of the second flange are adapted to be connected to each other by a third connecting element having substantially the shape of at least a segment of a ring and a fourth connecting element having substantiality the shape of at least a segment of a ring.
9. The flange connection according to claim 1, wherein at least one of the group consisting of the first connecting element and the second connecting element substantially has the shape of a plate.
10. The flange connection according to claim 1, wherein at least one of the first connecting element and the second connecting element is divided in more than one part in circumferential direction.
11. The flange connection of claim 1, wherein the flange connection is adapted to connect two parts of a wind energy tower to each other.
12. The flange connection according to claim 1, wherein the first connecting element and the second connecting clement are substantially comprised of a substantially rigid material.
13. A wind energy system, comprising:
- a) a nacelle including a rotor;
- b) a tower carrying the nacelle;
- c) a flange on at least a part of the tower, wherein the flange includes a first portion and a second portion extending in a substantially horizontal direction; and,
- d) a connecting element having substantially the shape of at least a segment of a ring, wherein the connecting element is adapted for being placed on the first portion of the flange and is adapted for securing at least a part of the tower.
14. The wind energy system according to claim 13, wherein at least one of the group consisting of the first portion of the flange and the connecting element provides a tapered shape.
15. The wind energy system according to claim 13, wherein the connecting element is divided in more than one part in the circumferential direction.
16. A tower section of a wind energy system, comprising:
- a) a flange on at least a part of the tower section, wherein the flange includes a first portion and a second portion extending in a substantially horizontal direction; and,
- b) a connecting element having substantially the shape of at least a segment of a ring, wherein the connecting element is placed on the first portion of the flange and is adapted for securing the tower section.
17. The tower section according to claim 16, wherein the connecting element is divided in more than one part in circumferential direction.
18. The tower section according to claim 16, wherein at least one of the first portion of the flange and the connecting element provides a tapered shape.
19. The tower section according to claim 16, further comprising a second connecting element adapted for being placed on the second portion of the flange and adapted for securing the tower section.
20. The tower section according to claim 16, wherein the connecting element is adapted for securing the tower section to at least one of another tower section of the wind energy system, a tower base ring, and a bearing at a tower top of the wind energy system.
Type: Application
Filed: Jan 17, 2012
Publication Date: Jul 18, 2013
Inventors: Venkata Krishna VADLAMUDI (Bangalore), Rajkumar Sivanantham (Banglore), Jay F. Leonard (Greenville, SC)
Application Number: 13/352,292
International Classification: E04H 12/00 (20060101); E04B 1/19 (20060101); E04B 1/38 (20060101);