GB2466863A

GB2466863A - An upright structure, particularly for use with wind turbines

Info

Publication number: GB2466863A
Application number: GB0920932A
Authority: GB
Inventors: Matthew James Harold Rawlings
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-11-28
Filing date: 2009-11-30
Publication date: 2010-07-14
Anticipated expiration: 2029-11-30
Also published as: GB2466863B; GB0821775D0; GB0920932D0

Abstract

The structure comprises at least one support mast 2, a body 16 and a mount pole 17, the body and mount pole being connected to form a top section that is mountable on each support mast to rotate about a pivot point 24. The mount pole may be secured to each support mast by a pin which is inserted through apertures in each support mast and mount pole. One or more straps may be used to constrain rotational movement of the mount pole relative to each support mast. Each support mast may include a hinged base plate securable to an anchor. The body may be a nacelle of a wind turbine, telecoms equipment, an electrical conductor, lighting, a camera, a display, traffic monitoring equipment or signage. A method for erecting the structure is also claimed such that the structure may be erected where access is restricted without the need for large scale mounting equipment. Erection of the structure may comprise use of a temporary lifting derrick, winch, pulley or jack.

Description

An apparatus and method for erecting wind turbines

Field of the Invention

The invention relates to an apparatus and method for erecting wind turbines in locations where access is restricted without the need for large scale mounting equipment.

Background of the Invention

Climate change coupled with high fuel prices is driving the development of renewable energy technology. In Europe today, renewable resources satisfy only 7% of the total energy consumption, but a target has been proposed to increase this contribution to 2O% by 2020. Of the various types of renewable energy, wind power has seen a 3O% annual growth and has a global capacity of over 100GW.

Wind power may be taken to mean the conversion of wind energy into electrical energy using a wind turbine. Wind turbines fall into two main categories based on the axis about which the turbine rotates. Turbines that rotate about a horizontal axis, horizontal-axis wind turbines (HAWT), are far more common than vertical-axis wind turbines (VAWT), although both are currently in use.

HAWTs have the main rotor shaft and electrical generator at the top of a tower and must be oriented to face the wind. Orientation of the rotor is typically achieved using a wind vane or a wind sensor and servo motor. Most have a gearbox which turns the slow rotation of the blades into a faster rotation that is suitable to drive the electrical generator. All of these components are typically housed within a single structure known as a nacelle. Since a tower produces turbulence behind it, the nacelle is normally positioned upwind of the tower to prevent damage to the nacelle and to enhance turbine performance. As a result, the blades have to be made sufficiently stiff to stop them from contacting the tower in high winds. Advantages of HAWTs include the pitch of the blades, which can be adjusted to achieve the optimum angle and collect the maximum amount of wind energy, and the height of the tower, which allows access to stronger, less turbulent winds at higher altitudes. The main disadvantage of this arrangement is the size of the structure. With towers and blades of up to 90m and 40m in length, respectively, HAWTs are difficult to transport and install.

VAWTs, on the other hand, have the main rotor shaft arranged vertically, with the generator and gearbox located close to the ground. A key advantage of this arrangement is that the turbine does not need to be oriented to face the wind. However, this type of turbine is 50% less effective than HAWTs mainly due to the additional drag associated with the blades rotating against the wind direction.

As well as the large scale wind turbines used for the commercial production of electricity which are normally grouped together in the same location to form a wind farm, smaller privately-owned turbines for supplying electricity to single homes or small businesses also exist. These small scale turbines vary in size from 2m in height with a capacity of 50W, up to 8m in height and a capacity of 10kW.

One of the problems associated with these small scale wind turbines is that they are usually located in places where access is limited. For example, areas of land adjacent to homes, offices and factories are often inaccessible to large scale lifting equipment, this equipment typically including lorry-mounted cranes or rough terrain forklift trucks, as seen in US2008/021630 tAt for example.

An apparatus and method for erecting wind turbines in locations where access is restricted without the need for large scale mounting equipment would be advantageous. A number of different ideas have previously been proposed that offer alternative methods of construction, three of which are briefly described below.

International patent application W02008/099129A2 discloses a wind turbine with collapsible mast and a method of installation. The tower of the turbine is pivotally connected to the ground such that a hoisting cable can be used to raise the pre-assembled turbine from a horizontal loading position to its upright state ready for operation. Temporary liffing derricks are also required to support the turbine as it is being lifted. With this invention, however, the turbine has to be pre-assembled before lifting can commence. This therefore requires the use of stronger lifting equipment than would be needed to erect a turbine from its component parts. In addition, unless the turbine is assembled onsite, transportation costs may prohibit use.

Granted US patent U56888264B1 describes an apparatus and method for mounting the nacelle on top of a pre-raised turbine tower comprising a carriage and a pair of spaced apart guide rails located on the side of the tower. The nacelle is first loaded onto the carriage at ground level, and then hoisted to the top of the tower using a winch before being secured in position. Once the nacelle is installed, the carriage is then lowered to the ground and detached for use on another turbine. The main drawback of this technique is the increased cost associated with the rail and carriage.

The invention described in US patent application U52007/0290426A1 uses cables to hoist the components of the rotor to the top of the tower for mounting. This invention also provides support cables to steady the components as they are being raised. Whilst this method may be capable of assembling the blades of the rotor once the nacelle is in position, it does not appear to be suitable for raising the nacelle itself nor any of its heavier components.

It would therefore be desirable to provide an alternative and improved apparatus and method for mounting a small scale wind turbine.

The present invention seeks to overcome or at least alleviate the problems associated with

the prior art

Summary of the Invention

The invention provides an apparatus and method for erecting a body such as a wind turbine in locations where access is restricted, without the need for large scale mounting equipment. In addition, the apparatus used to construct the turbine also provides support for the structure once the turbine is in operation. Furthermore, since the method involves onsite construction of the turbine from its component parts, transportation costs are kept to a minimum.

According to one aspect of the invention, there is provided a structure such as a wind turbine comprising at least one support mast, a body such as a a nacelle and a mount pole such as a turbine mount pole, wherein the nacelle and turbine mount pole are connected together to form a top section of the turbine, and wherein said top section is mountable on the at least one support mast to rotate about a pivot point. When the turbine mount pole is rotated to a position where the said pole is substantially parallel to the axis of the at least one support mast, the nacelle may be in the uppermost position. Alternatively, the turbine mount pole and hence nacelle may be lifted vertically using a jack for example.

The structure of the invention is not limited to wind turbines and may be used in connection with other apparatus having similar requirements. For example, telecommunications masts, support poles or pylons for cables transmitting electrical power or signals, platforms such as those used as observation platforms, lighting equipment, traffic lights, traffic signage, traffic monitoring equipment, cameras and the like.

According to another aspect of the invention, there is provided a method of erecting a wind turbine comprising the steps of: i) hoisting at least one support mast to a substantially vertical position; ii) securing the at least one support mast in the substantially vertical position; iii) lifting the turbine mount pole, having a nacelle attached thereto, towards the top of the at least one support mast; iv) pivotally attaching the turbine mount pole to the at least one support mast; v) rotating the turbine mount pole until the axis of the turbine mount pole is substantially parallel to the axis of the at least one support mast; and vi) fixing the turbine mount pole to the at least one support mast with fixing members.

According to another aspect of the invention, there is provided a top-heavy upright structure comprising at least one support mast, a body and a mount pole, wherein the body and mount pole are connected together to form a top section of the structure, and wherein said top section is mountable on the at least one support mast to rotate about a pivot point.

Advantageously, the structure further comprises a hoisting means.

Preferably, the structure includes a temporary lifting derrick.

In a preferred embodiment, the at least one support mast includes a hinged base plate securable to an anchor.

Advantageously, the structure further comprises a lifting means.

Preferably, the lifting means is a winch and pulley.

In a preferred embodiment, the lifting means is attachable to the top section proximate to the centre of gravity of the top section or to the at least one support mast.

Advantageously, the pivot point is positioned proximate to the body.

Preferably, the structure further comprises at least one securing member arranged to secure the mount pole to the at least one support mast when said mount pole and the at least one support mast are substantially aligned.

In a preferred embodiment, the at least one securing member includes at least one pin.

Advantageously, the at least one pin is inserted through apertures in the at least one support mast and mount pole.

Preferably, the at least one securing member includes at least one strap.

In a preferred embodiment, the at least one securing member comprises at least two straps arranged in pairs on either side of the at least one support mast, said straps constraining movement of the mount pole.

Advantageously, the top section includes a lifting point.

Preferably, the body is a construction arranged to support telecommunications equipment.

In a preferred embodiment, the telecommunications equipment comprises at least one antenna for transmitting or receiving information.

Advantageously, the body is a construction arranged to support overhead electricity conductors for electric power transmission.

Preferably, the body is a platform for standing on.

In a preferred embodiment, the platform is an observation platform.

Advantageously, the body comprises lighting equipment.

Preferably, the lighting equipment is street lighting equipment.

In a preferred embodiment, the lighting equipment incorporates traffic lights.

Advantageously, the body comprises at least one panel for displaying information.

Preferably, the information is one of the following: road safety, a travel report, a map, directions, a place name, parking information and advertising.

In a preferred embodiment, the body comprises traffic enforcement equipment.

Advantageously, the traffic enforcing equipment incorporates at least one of the following: a speed camera, a red light camera, a bus lane camera, a toll booth camera, a level crossing camera, a congestion charge camera, a double solid line camera, a high occupancy vehicle lane camera, a turn camera and a parking camera.

Preferably, the body comprises traffic monitoring equipment.

In a preferred embodiment, the traffic monitoring equipment is capable of monitoring at least one of the following: vehicle flow, vehicle speed, vehicle classification and vehicle direction.

According to another aspect of the invention, there is provided a method of erecting a structure comprising the steps of: i) hoisting at least one support mast to a substantially vertical position; ii) securing the at least one support mast in the substantially vertical position; iii) lifting a mount pole, having a body attached thereto, towards the top of the at least one support mast; iv) pivotally attaching the mount pole to the at least one support mast; v) rotating the mount pole until the axis of the mount pole is substantially parallel to the axis of the at least one support mast; and vi) fixing the mount pole to the at least one support mast with fixing members.

Advantageously, the method further comprises the steps of: i) securing the at least one support mast and mount pole to constrain relative movement therebetween; ii) removing all fixing members fixing the at least one support mast to the mount pole; iii) raising the mount pole vertically with respect to the at least one support mast; and iv) re-fixing the mount pole to the at least one support mast with the fixing members.

Preferably, the method includes the further steps of: i) securing the at least one support mast and mount pole to constrain relative movement therebetween; ii) removing all fixing members fixing the at least one support mast to the mount pole; iii) raising the mount pole vertically with respect to the at least one support mast; and iv) re-fixing the mount pole to the at least one support mast with the fixing members.

Preferably, the at least one support mast is hoisted using a temporary lifting derrick.

In a preferred embodiment, the at least one support mast is secured in the vertical position by an anchoring means.

Advantageously, the mount pole is lifted using a winch and pulley.

Preferably, the mount pole is rotated manually or using a rope or cable.

In a preferred embodiment, the strapping means comprises at least two bars fixed to the at least one support mast.

Advantageously, the turbine mount pole is raised using a jack.

Brief Description of the Drawings

In the drawings, which illustrate preferred embodiments of the invention and are by way of

example:

Figure 1 shows the support masts being hoisted into the vertical operating position by means of a winch and temporary lifting derrick; Figure 2 shows the support masts fixed in the vertical operating position; Figure 3a shows the nacelle and turbine mount pole attached to a pulley ready for lifting; Figure 3b shows the nacelle and turbine mount pole at the top of the support masts; Figure 3c shows the nacelle and turbine mount pole being rotated into the vertical operating position; Figure 3d shows the nacelle and turbine mount pole fixed in the vertical operating position; Figure 4 shows a strap used to secure the turbine mount pole in the vertical position; and Figure 5 shows the turbine mount pole jacked to a higher position.

Figure 6 shows another embodiment of the present invention.

Detailed Description of the Preferred Embodiments

Referring to Figure 1, there is illustrated the first step involved in the construction of a small scale HAWT. A support mast or tower 1 comprises two elongate mast members 2 (each containing a plurality of carefully spaced bores 3 which will be described later) and base plate 4 pivotally connected to a concrete foundation block 5. The concrete foundation block 5 is situated in the ground 6 at a depth determined by the local ground conditions and acts to anchor the support masts 2. A temporary lifting derrick is used to hoist the support masts 2 from a horizontal loading position to a vertical operating position. The lifting derrick 7 could take various forms but is shown in Figure 1 simply as a tower-like framework 8 with leg supports 9 and two pulleys 10. A derrick 7 is a load-bearing structure used for lifting and moving heavy objects. It differs from a crane by a pivotal boom 11 at its lower end which allows the derrick to adopt different angles of inclination. This feature combined with a high strength-to-weight ratio make derricks 7 a more suitable option than cranes for the task described herein. A hoisting rope or cable 12 is passed over pulleys 10 located both at the top of the derrick framework 8 and on the ground adjacent to the derrick 7. This rope 12 is also attached to a winch 13 such that the length of the rope 12 and the inclination angle of the derrick 7 may be adjusted by operating the winch 13. By connecting a second rope or cable 14 from the top of the derrick 7 to a loop 22 or one of the bores 3 on the top of the support masts 2, the support masts 2 can be raised to the vertical position by operating the winch 13. Once the support masts 2 are in the vertical operating position, studs 15 can be used to fix the base plate 4 to the concrete foundation block 5, after which the temporary lifting derrick 7 and winch 13 can be dismantled. Figure 2 shows the support masts 2 fixed in the vertical operating position.

Referring now to Figures 3a to 3d, there is illustrated the second step involved in the construction of a small scale HAWT. The nacelle 16 of the wind turbine is fixed to a long, narrow pole, herein referred to as the turbine mount pole 17. The turbine mount pole 17 incorporates a plurality of spaced bores 18 positioned to align with those of the support masts 2, and a bracket or eye 23 for lifting the turbine mount pole 17. The nacelle 16 may comprise any of the usual turbine components including a rotor 26, blades 27, gearbox, brake, generator, cooling means, wind vane, anemometer, swivel, and a controller. A temporary pulley 19 is attached to the top of the support masts 2 through one of the bores 3. One end of a rope or cable 20 is connected to a wrnch 21 whilst the other end is passed over the pulley 19 and connected to the turbine mount pole 2. By operating the winch 21, the nacelle 16 and turbine mount pole 17, which are pre-connected, can be raised to a selected height. The eye 23 is positioned on the turbine mount pole 17 close to the centre of gravity to ensure that the nacelle 16 is distanced from the support masts 2 whilst it is being lifted to help prevent the blades 27 from being damaged. Once the turbine mount pole 17 is raised to the top of the support masts 2, a bore 18 in the turbine mount pole 17 is aligned with a bore 3 in the support masts 2 before a pin (the pivot pin 24) is inserted through the bores 3,18 to serve as a pivot point for the turbine mount pole 17. With the pivot pin 24 now in position, the nacelle 16 and turbine mount pole 17 are rotated until the axes of the turbine mount pole 17 and support masts 2 are aligned, after which locking pins 25 are inserted through aligned bores 3,18 located at the top and bottom of the support masts 2. The pivot point is located close to the nacelle 16 to minimise the bending moment applied to both the turbine mount pole 17 and the support masts 2, and also to provide maximum leverage to reduce the force required to rotate the turbine mount pole 17 into position.

Referring now to Figure 4, there is shown a strap 28 used to secure the turbine mount pole 17 in the vertical position once the locking pins 25 have been inserted. The strap 28 could take different forms, but is shown in Figure 4 as a bar fixed across the ends of the support masts 2 to enclose the turbine mount pole 17 and prevent it from rotating about the pivot pin 24 when the locking pins 25 are removed. In this embodiment, bars are required across opposite sides of the turbine mount pole 17 to prevent rotation in both directions. Multiple sets of straps 28 may be fixed at different heights on the support masts 2 to provide additional support for the turbine mount pole 17, which in particular allow the turbine mount pole 17 and hence the nacelle 16 to be raised with respect to the support masts 2 as described in detail below.

Referring now to Figure 5, there is illustrated the third optional step involved in the construction of a small scale wind turbine. Once the straps 28 are secured in position, the locking pins 25 can safely be removed without fear of the turbine mount pole 17 rotating about the pivot pin 24 under the weight of the nacelle 16. This allows the turbine mount pole 17 to be raised higher once the pivot pin 24 is removed so that the turbine is able to take advantage of the stronger, less turbulent winds found at higher altitudes. At this stage a jacking point must be assembled before the pivot pin 24 is removed otherwise the turbine mount pole 17 would slide downward between the support masts 2 under the weight of the nacelle 16. With the jacking point assembled, for example by inserting a pin through one of the bores 18, and pivot pin 24 removed, the turbine mount pole 17 is raised using a jack to the pre-deterniined height within the support masts 2 until a bore 18 in the mount pole is aligned with bores 3 in the support masts. At the desired height, locking pins 25 are then inserted through the bores 3,18 to hold the turbine mount pole 17 in place securely.

Advantageously, the support masts 2 and turbine mount pole 17 would contain bores 3,18 at several positions to provide a variety of possible heights, so that the nacelle 16 can be further adjusted to adapt to changes in the wind gradient In order to attach/detach the locking pins 25, pivot pin 24 and pulley 19, access must be provided to the top of the support masts 2. This could be achieved with a ladder or climbing rungs (not shown) attached to the support masts 2, thus negating the need for scaffolding or any hydraulic lifting system. Such means would also provide access to the free end 29 of the turbine mount pole 17 when rotating the nacelle 16 into position. Alternatively, a temporary rope or cable (not shown) could be fed through the lowest bore 18 at the free end of the turbine mount pole 17 before lifting the turbine mount pole 17 to the top of the support masts 2. This would allow rotation of the turbine mount pole 17 to be controlled from the ground, but the rope would of course have to be removed after rotation so that the turbine mount pole 17 could be fixed in position.

As a rough guide to the size and weight of the wind turbines envisaged for construction using the apparatus and method described herein, the support masts 2 may each be around 7.5m in length and weigh around 135kg, whilst the combined nacelle 16 and turbine mount pole 17 will typically weigh in excess of 300kg. The length of the turbine mount pole 17 will be around the same length as the support masts 2, with the pivot point located about lm from the nacelle 16. The material of choice for each part would typically be box section steel, but could be any material with similar properties.

Despite the focus on small scale wind turbines, this apparatus and method may also be applied to turbines on a larger scale, such as those installed in wind farms for the commercial production of electricity. For this purpose, however, the lifting equipment and materials for construction would have to be stronger than those used in the construction of turbines for home and small business use.

Furthermore, this apparatus and method may be used for erecting other structures. For example, the invention may be applied to (but is not limited to) the construction of mobile phone masts/towers, television masts/towers, radio masts/towers, electricity pylons, observation towers, lamp posts, traffic lights, sign posts, traffic enforcement equipment and traffic monitoring equipment. Figure 6 shows a telecommunications tower 30 installed using the apparatus and method of the present invention. As with wind turbines, the lifting equipment and materials for construction would need to be selected to suit the particular structure.

Claims

Claims 1. An upright structure comprising at least one support mast, a body and a mount pole, wherein the body and mount pole are connected together to form a top section of the structure, and wherein said top section is mountable on the at least one support mast to rotate about a pivot point.
2. A structure according to Claim 1, further comprising a hoisting means.
3. A structure according to Claim 2, wherein the hoisting means includes a temporary lifting derrick.
4. A structure according to any preceding claim, wherein the at least one support mast includes a hinged base plate securable to an anchor.
5. A structure according to any preceding claim, further comprising a lifting means.
6. A structure according to Claim 5, wherein the lifting means is a winch and pulley.
7. A structure according to Claim 5 or 6, wherein the lifting means is attachable to the top section proximate to the centre of gravity of the top section or to the at least one support mast.
8. A structure according to any preceding claim, wherein the pivot point is positioned proximate to the body.
9. A structure according to any preceding claim, further comprising at least one securing member arranged to secure the mount pole to the at least one support mast when said mount pole and the at least one support mast are substantially aligned.
10. A structure according to Claim 9, wherein the at least one securing member includes at least one pin.
11. A structure according to Claim 10, wherein the at least one pin is inserted through apertures in the at least one support mast and mount pole.
12. A structure according to any of Claims 9 to 11, wherein the at least one securing member includes at least one strap.
13. A structure according to any of Claims 9 to 12, wherein the at least one securing member comprises at least two straps arranged in pairs on either side of the at least one support mast, said straps constraining movement of the mount pole.
14. A structure according to any preceding claim, wherein the top section includes a lifting point.
15. A structure according to Claim 14, further comprising a lifting means.
16. A wind turbine comprising a structure according to any preceding claim, wherein the body is a nacelle of a wind turbine.
17. A structure according to any of Claims 1 to 15, wherein the body includes at least one of the following group: telecommunications equipment, an electrical conductor for electrical power transmission, a platform, lighting equipment, traffic signage, traffic monitoring equipment, a camera, and a display.
18. A structure substantially as shown in, and as described with reference to, the drawings.
19. A method of erecting a structure comprising the steps of: i) hoisting at least one support mast to a substantially vertical position; ii) securing the at least one support mast in the substantially vertical position; iii) lifting a mount pole, having a body attached thereto, towards the top of the at least one support mast; iv) pivotally attaching the mount pole to the at least one support mast; v) rotating the mount pole until the axis of the mount pole is substantially parallel to the axis of the at least one support mast; and vi) fixing the mount pole to the at least one support mast with fixing members.
20. A method according to Claim 19, further comprising the steps of: i) securing the at least one support mast and mount pole to constrain relative movement therebetween; ii) removing all fixing members fixing the at least one support mast to the mount pole; iii) raising the mount pole vertically with respect to the at least one support mast; and iv) re-fixing the mount pole to the at least one support mast with the fixing members.
21. A method according to Claim 19 or 20, wherein the at least one support mast is hoisted using a temporary lifting derrick.
22. A method according to any of Claims 19 to 21, wherein the at least one support mast is secured in the vertical position by an anchoring means.
23. A method according to any of Claims 19 to 22, wherein the mount pole is lifted using a winch and pulley.
24. A method according to any of (kitnR 19 to 23, wherein the mount -is raised using a