U.S. patent application number 10/516062 was filed with the patent office on 2006-06-08 for method and crane for installing, maintaining and decommissioning wind turbines.
Invention is credited to James Ingram, Stuart McIntyre, Stewart Kenyon Willis.
Application Number | 20060120809 10/516062 |
Document ID | / |
Family ID | 29587402 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060120809 |
Kind Code |
A1 |
Ingram; James ; et
al. |
June 8, 2006 |
Method and crane for installing, maintaining and decommissioning
wind turbines
Abstract
Method and apparatus for installing, maintaining and
decommissioning wind turbines, both onshore and offshore, comprises
a crane having extendable legs that allow it to climb a tower that
it is erecting in sections by engaging the tower by friction or
mechanical interference. The crane may carry the wind turbine
nacelle on its upper members during construction of the tower and
may be fitted with a crane for handling tower sections, or it may
carry an "A" crane for lifting the nacelle and its components once
the tower is complete or for constructing heavy maintenance. The
crane may be fitted with various lifting and handling means to
facilitate maintenance or the installation, maintenance or removal
or airfoil rotor blades.
Inventors: |
Ingram; James; (Aberdeen,
GB) ; Willis; Stewart Kenyon; (Aberdeenshire, GB)
; McIntyre; Stuart; (Aberdeen, GB) |
Correspondence
Address: |
KIRKPATRICK & LOCKHART NICHOLSON GRAHAM LLP
STATE STREET FINANCIAL CENTER
ONE LINCOLN STREET
BOSTON
MA
02111-2950
US
|
Family ID: |
29587402 |
Appl. No.: |
10/516062 |
Filed: |
May 27, 2003 |
PCT Filed: |
May 27, 2003 |
PCT NO: |
PCT/GB03/02287 |
371 Date: |
September 8, 2005 |
Current U.S.
Class: |
405/195.1 |
Current CPC
Class: |
E02D 27/42 20130101;
F05B 2240/916 20130101; E02D 27/425 20130101; E02B 2017/0091
20130101; Y02P 70/50 20151101; F03D 13/22 20160501; Y02E 10/72
20130101; F05B 2230/6102 20130101; Y02E 10/727 20130101; F03D 13/10
20160501; Y02E 10/728 20130101; F05B 2240/95 20130101 |
Class at
Publication: |
405/195.1 |
International
Class: |
E21B 17/01 20060101
E21B017/01 |
Foreign Application Data
Date |
Code |
Application Number |
May 28, 2002 |
GB |
0212258.8 |
Aug 29, 2002 |
GB |
0219994.1 |
Nov 29, 2002 |
GB |
0227870.3 |
Claims
1. Apparatus for use in the onshore and offshore wind farm
industry, said apparatus comprising a jacking crane and a plurality
of tower sections adapted to be combined to form a tower on which a
nacelle and one or more blades are mounted, wherein the jacking
crane is adapted to be extended and climb upwards on the tower as
the tower is erected from the tower sections and is used to
position each of the tower sections during erection, and is further
adapted to mount the nacelle and one or more blades the tower.
2-7. (canceled)
8. Apparatus as claimed in claim 1, wherein the nacelle is
positioned on top of the jacking crane.
9. (canceled)
10. Apparatus as claimed in claim 1, wherein the jacking crane
comprises a number of legs capable of being extended and
retracted.
11-13. (canceled)
14. Apparatus as claimed in claim 1, wherein the tower sections are
buoyant.
15. (canceled)
16. Apparatus as claimed in claim 1, wherein the jacking crane has
a winch adapted to lift each of the tower sections into a position
on top of a previous tower section.
17. Apparatus as claimed in claim 16, wherein the winch is located
within the nacelle.
18-19. (canceled)
20. Apparatus as claimed in claim 1, wherein the nacelle rotates on
top of the jacking crane to facilitate lifting operations.
21. Apparatus as claimed in claim 1, wherein the nacelle is
equipped with a winch or crane adapted to assist with the
installation of the nacelle or blades and their subsequent
maintenance or replacement.
22-24. (canceled)
25. Apparatus as claimed in claim 1, wherein the tower sections are
provided with purpose built attachment points, which are adapted to
receive the jacking mechanism.
26. Apparatus as claimed in claim 25, wherein the purpose built
attachment points are pockets.
27. (canceled)
28. Apparatus as claimed in claim 1, wherein the jacking crane has
one or more clamps which engage the tower sections by compression
and friction.
29-32. (canceled)
33. Apparatus as claimed in claim 28, wherein the one or more
clamps are mounted on an arrangement of struts, ties and beams
which are capable of being adjusted to accommodate a change in the
cross section of the tower or tower sections.
34. Apparatus for use in the onshore and offshore wind farm
industry, said apparatus comprising a jacking crane and a plurality
of tower sections which can be combined to erect a tower on which a
nacelle and one or more blades can be mounted using the same
jacking crane, wherein the jacking crane comprises a friction clamp
having a flexible backing substrate that is tensioned at the
ends.
35. Apparatus as claimed in claim 34, wherein the flexible backing
substrate contacts the tower in a plurality of locations or
sections to provide even distribution of load.
36. Apparatus as claimed in claim 34, wherein the length of the
flexible backing substrate can be altered to ensure the clamp
maintains a secure fit to the tower.
37. Apparatus as claimed in claim 36, wherein the length of the
flexible backing substrate is adjusted using rollers or
sprockets.
38. Apparatus as claimed in claim 37, wherein the ends of the
flexible substrate are made from or covered with a compliant
material, and are adapted to be passed around the rollers or
sprockets which rotate as the length of the substrate is
altered.
39-40. (canceled)
41. Apparatus as claimed in claim 34, wherein the tower sections
have a high grip surface achieved by the use of anti-slip paint or
glue-on grip strips.
42-51. (canceled)
52. Apparatus as claimed in claim 1 wherein the jacking crane
comprises facilities for construction or maintenance personnel.
53-68. (canceled)
69. A jacking crane the for use in the construction of wind turbine
apparatus for the onshore and offshore wind farm industry, said
jacking crane comprising: means for positioning a plurality of
tower sections to form a tower; a jacking mechanism adapted to be
extended and climb upwards on the tower as the tower is erected
from the tower sections, and; means for carrying a nacelle on the
jacking crane as the as the tower is erected.
70. A jacking crane the for use in the construction of wind turbine
apparatus for the onshore and offshore wind farm industry, said
jacking crane comprising: means for positioning a plurality of
tower sections to form a tower; a jacking mechanism adapted to be
extended and climb upwards on the tower as the tower is erected
from the tower sections, and; a friction clamp having a flexible
backing substrate which contacts the tower in a plurality of
locations or sections to provide even distribution of load.
71. A method of constructing wind turbine apparatus for the onshore
and offshore wind farm industry, the method comprising the steps
of: a. Providing a jacking crane and a nacelle on a foundation
platform, the nacelle being positioned on the jacking crane; b.
Erecting a tower from a plurality of tower sections by positioning
each tower section using the jacking crane; c. Extending the
jacking crane to climb up the tower as the tower is erected while
carrying the nacelle on the jacking crane; and d. Installing the
nacelle on top of the erected tower.
72. The method as claimed in claim 71, wherein the method is
automated.
73. The method as claimed in claim 71, wherein the method is
controlled by remote control.
Description
[0001] The present invention relates to a self-installing tower,
nacelle and blades which may be used in the onshore and offshore
wind farm industry.
[0002] The use of fossil fuels such as coal, oil and natural gas,
has become increasingly undesirable as evidence has emerged that
the burning of these fuels is a key factor in environmental
problems, such as global warming, air quality deterioration, oil
spills and acid rain. These problems, together with the depletion
of fossil fuel resources, have encouraged the search for
alternative energy resources.
[0003] Wind energy is recognised world wide as a proven technology
which can be utilised to meet the world's increasing electricity
demands in a sustainable economical and, most importantly,
environmentally friendly manner. In particular, wind power can be
used to generate electricity without air emissions, water pollution
or waste products, and can greatly reduce the pollution which is
currently generated by fossil fuels.
[0004] As a result of its advantageous properties, wind energy is
currently the fastest growing source of electricity in the world.
However, the erection of onshore wind farms is often controversial
due to the visual impact of large and cumbersome wind turbines,
which are visible for miles around. Often, the erection of wind
farms is opposed by residents of nearby populated areas who regard
them as unsightly or feel that their presence will reduce property
values in the area. In addition, a variety of restrictions have
affected the construction of these wind farms, including planning
constraints and restrictions on the visual impact and sound
emissions from the turbines.
[0005] Because of these underlying problems, the idea of taking the
wind industry offshore has developed. Offshore wind farms have
minimal environmental effects and do not encounter the same
planning restrictions or difficulties with nearby residents that
have arisen with the development of onshore wind farms. As a
consequence, the size and sound emissions of the farms do not have
to be strictly regulated and much larger multi-megawatt machines
can be used. In addition, the size of the offshore resource is
huge, even when restrictions such as shipping lanes, areas of
limited sea depth and known dumping grounds are taken into
account.
[0006] Whilst the erection of wind farms offshore has some
advantages over on-land farms, construction of the turbines used to
generate electricity is more expensive than onshore farms. In fact
it is estimated that capital costs are in the region of 30% to 50%
higher offshore due to the larger machine size, maintenance and
operational costs, including the cost of transporting and
installing the wind turbines (including the towers) at sea. It will
be appreciated that the construction of the wind-towers, delivery
to site and assembly of these large machines require specialised
equipment and this greatly increases the cost in installation,
maintenance and decommissioning an offshore farm.
[0007] A problem with wind turbines is that they are big, and
produce a relatively small amount of power (revenue). Therefore,
they need to be installed as efficiently and cheaply as possible,
whilst at the same time minimising the risks to personnel. The
construction industry as a whole is one of the most dangerous
commercial activities undertaken in Europe, with the wind industry
being no different. Given the low energy density of wind
generation, poor safety statistics would mean that the industry as
a whole would run the risk of being seen as a dangerous means of
generation when measured on a "per unit of power generated" basis.
Apparatus is therefore required to make construction of wind farms
safer and deliver improved cost, safety and environmental outcomes.
They should ultimately operate very reliably for many years.
[0008] At present, a commonly used method for constructing offshore
wind turbines uses a floating crane vessel. Typically a specially
adapted ship is piloted to the area where the turbine is to be
constructed. Generally as a result of the size of the crane and
tower structure they must carry, these vessels are large in size,
and thus relatively expensive to use. Once the vessel has reached
the area where the turbine is to be positioned, a concrete
structure often known as a "gravity foundation" is placed onto the
seabed. A pylon-like turbine tower is then fitted onto the concrete
foundation using the cranes, the turbine tower carrying the blades
which spin upwind of the tower itself. However, this process incurs
significant costs as it is necessary for the crane carrying vessel
to be of a sufficiently large size to carry the pylon-like turbine
tower and the vessel must remain in the area in order to support
the operation.
[0009] It is therefore an object of the present invention to
provide a self-installing or self-erecting wind tower, nacelle and
blades, which can be erected in a manner, which is easier and
cheaper than conventional wind towers, nacelles and blades.
Particularly it is an object of the present invention to provide a
self-installing or self-erecting wind tower which is reversible,
i.e. can be dismantled, either in entirety or in part, as easily as
it can be erected, is complete and "self sufficient"--i.e., can be
built from an already constructed structure.
[0010] It is a particular object of the present invention to
provide a wind tower, which can be self-erected both offshore and
onshore without the need for specialist vessels or cranes.
[0011] According to the present invention there is provided
apparatus for use in the onshore and offshore wind farm industry,
said apparatus comprising a jacking crane and a plurality of tower
sections which can be combined to erect a tower on which a nacelle
and one or more blades can be mounted using the same jacking
crane.
[0012] Advantageously the jacking crane can be extended and climb
upwards on the tower as the tower is erected from the tower
sections and is used to position each of the tower sections during
erection.
[0013] The tower is erected from the tower sections on a foundation
platform. The jacking crane, tower sections and nacelle may be
attached to or loaded onto the foundation platform before it is
towed to the offshore location. Alternatively, the jacking crane,
tower sections and nacelle may be loaded onto the foundation
platform after it has been towed to the offshore location.
[0014] Preferably the nacelle is positioned on top of the jacking
crane. Where the jacking crane, tower structure and nacelle are
loaded onto the foundation platform after it has been towed to the
offshore location, the jacking crane may be transferred from a
vessel such as a ship or boat onto the foundation platform with the
nacelle positioned on top of the jacking crane.
[0015] Most preferably the jacking crane acts as a motion
compensation system during transferral from the vessel to the
foundation platform.
[0016] The jacking crane may be hydraulically operated.
[0017] The jacking crane comprised a number of legs which can
extend and retract. Preferably the jacking crane has four legs.
[0018] The tower sections may be approximately 10-25 metres in
length.
[0019] Preferably the tower sections are air and water-tight, or
can contain buoyancy units. Most preferably the tower sections are
buoyant. Advantageously, this aids towing of the foundation
platform to the offshore location.
[0020] Preferably the jacking crane has a winch or which can be
used to lift each of the tower sections into position, on top of
the previous tower section. The winch may be located within the
nacelle.
[0021] The tower sections may be mounted on or attached to the
foundation platform. Alternatively, the tower sections may be
transferred from a vessel onto the foundation platform.
[0022] Optionally the nacelle may rotate on top of the jacking
crane to facilitate lifting operations.
[0023] Optionally the nacelle may be equipped with a winch or crane
intended to assist with the installation of the nacelle or blades
and their subsequent maintenance or replacement of the equipment
within the nacelle or blades and then may be used to assist
installation.
[0024] Optionally a boom may be attached to the jacking crane.
[0025] Optionally offshore the apparatus may also comprise a
seawater ballast to counterbalance the boom.
[0026] Preferably the jacking crane is securely anchored to the
tower during and after erection and may have a mechanism to prevent
detachment from the tower. The tower sections may be provided with
purpose built attachment points, which are adapted to receive the
jacking crane.
[0027] Optionally the purpose built attachment points are pockets.
The jacking crane may have a first and second grip assembly which
are adapted to fit into the pockets.
[0028] Optionally the jacking crane may have one or more clamps,
which engage the tower sections. Advantageously this provides a
secure and safe anchorage of the jacking crane to the tower.
[0029] Preferably the one or more clamps grip the tower sections by
compression and friction.
[0030] The one or more clamps may include contact pads, which are
made from a compliant material such as polyurethane. The contact
pads can be brought into contact with one of the tower sections and
will develop vertical frictional resistance upon the application of
pressure.
[0031] Preferably the one or more clamps are mounted on an
arrangement of struts, ties and beams which can be adjusted to
accommodate a change in the cross section of the tower or tower
sections. In this manner the jacking crane can be adapted for use
on a variety of wind turbine tower designs, or on a tapered wind
turbine tower.
[0032] Preferably the contact pads are mounted on a flexible
backing substrate that is tensioned at the ends. Preferably the
flexible backing substrate contacts the tower in a plurality of
locations or sections to provide even distribution of load.
[0033] Preferably the length of the flexible backing substrate can
be altered to ensure the clamp maintains a secure fit to the tower.
In a preferred embodiment this is achieved by the inclusion of
rollers or sprockets. The ends of the flexible substrate are
preferably made from, or covered with a complaint material and are
adapted to be passed around the rollers or sprockets which rotate
as the length of the substrate is altered.
[0034] Preferably the one or more clamps can be locked.
[0035] Preferably the tower sections have means for improving the
attachment of the jacking crane. For example they may have a high
grip surface achieved by the use of anti-slip paint or glue-on grip
strips.
[0036] Mechanical toothed wedges may also be incorporated into the
tower, tower sections, jacking crane or clamps which engage a
wedging action between the tower and jacking crane.
[0037] Preferably the jacking crane is also used to transport the
blades up the tower, for attachment to the nacelle. This process
can also be carried out in reverse to transport the blades down the
tower during decommissioning.
[0038] The jacking crane may also be used for maintenance
purposes.
[0039] Preferably the jacking crane can be connected to a variety
of interface tools. For example, the jacking unit may be adapted to
carry tools, which are used for inspection and/or replacement
and/or repair of the blades, nacelle or tower sections.
[0040] The jacking crane may comprise framework or a crane capable
of plumbing or reaching into the nacelle.
[0041] The framework or additional crane can lift the nacelle or a
sub component of the nacelle. Advantageously this allows the
nacelle to be lifted after the tower is completed.
[0042] The framework or additional crane can also be used for
maintenance of the tower and tower sections. Optionally the
framework or additional crane is extendible.
[0043] Where the jacking crane comprises a crane, said crane may be
a knuckle boom crane.
[0044] The jacking crane may comprise a working platform and
facilities for construction or maintenance personnel. These may be
testing, monitoring, or service facilities, or welfare facilities
for personal use.
[0045] According to a second aspect of the present invention, there
is provided a method for installing the apparatus of the first
aspect of the present invention in an offshore location, the method
comprising the steps of: [0046] (a) loading or attaching tower
sections on to the foundation platform; [0047] (b) towing the
foundation platform to an offshore location using a transportation
vessel; [0048] (c) anchoring the foundation platform in the
offshore position, removing buoyancy from tower sections or other
buoyancy units (possibly by flooding); [0049] (d) transporting the
jacking crane and nacelle from the transportation vessel to the
foundation platform; [0050] (e) removing the transportation vessel,
if required; [0051] (f) extending the jacking crane vertically;
[0052] (g) winching a first tower section from the foundation
platform into position with the jacking crane; [0053] (h) extending
the jacking crane; [0054] (i) winching a second tower section from
the foundation platform into position with the jacking crane and on
top of the first tower section; [0055] (j) repeating steps (f) to
(i) with further tower sections to erect a tower; and [0056] (k)
mounting turbine blades on to the nacelle.
[0057] The tower sections may be used to provide buoyancy to
foundation platform as it is towed to the offshore location.
[0058] Optionally the transportation vessel may be removed during
anchoring of the foundation platform, and may return for step
(d).
[0059] Preferably the jacking crane is used to raise the turbine
blades up to the nacelle. The winch in the nacelle may be used to
transport the blades from the boat to the platform.
[0060] The method may be automated.
[0061] The method may be controlled by remote control.
[0062] According to a third aspect of the present invention there
is provided a method for installing the apparatus of the first
aspect of the present invention on an offshore foundation platform,
the method comprising the steps of: [0063] (a) towing a foundation
platform to an offshore location using a transportation vessel;
[0064] (b) transporting the jacking crane and nacelle from the
transport vessel to the foundation platform; [0065] (c)
transporting a first tower section onto the foundation platform
from the transportation vessel; [0066] (d) positioning the first
tower section within and attached to the jacking crane; [0067] (e)
transporting a second tower section onto the foundation platform
from the transportation vessel; [0068] (f) extending the jacking
crane; [0069] (g) winching the second tower section into position
on top of the first tower section within the jacking crane; [0070]
(h) repeating step d) to f) with further tower sections to erect a
tower; [0071] (i) transporting a blade onto the foundation platform
for mounting on the nacelle from the transportation vessel,
possibly using winch inside nacelle; [0072] (j) moving the jacking
crane up the tower to a position where the blade can be mounted on
the nacelle; and [0073] (k) repeating steps g) to h) for subsequent
blades.
[0074] The method may be automated.
[0075] The method may be controlled by remote control.
[0076] According to a fourth aspect of the present invention, there
is provided a method for installing the apparatus of the first
aspect of the present invention on an foundation platform, the
method comprising the steps of: [0077] (a) loading the nacelle,
tower sections and jacking crane onto an foundation platform;
[0078] (b) towing the foundation platform to an offshore location
using a transportation vessel; [0079] (c) anchoring the foundation
platform to the sea bed at the offshore location; [0080] (d)
removing the transportation vessel; [0081] (e) extending the
jacking crane; [0082] (f) winching a first tower section from the
foundation platform into position with the jacking crane; [0083]
(g) extending the jacking crane; [0084] (h) winching a second tower
section from the foundation platform into position with the jacking
crane and on top of the first tower section; [0085] (i) repeating
steps (e) to (h) with further tower sections to erect a tower;
[0086] (j) mounting the nacelle on the top of the tower; and [0087]
(k) mounting turbine blades on to the nacelle.
[0088] The method may be automated.
[0089] The method may be controlled by remote control.
[0090] Preferably the jacking crane is used to raise the turbine
blades up to the nacelle. The winch in the nacelle may be used to
transport the blades from the boat to the platform.
[0091] According to a fifth aspect of the present invention, there
is provided a method for installing the apparatus of the first
aspect of the present invention on a foundation platform or other
foundation, the method comprising the steps of: [0092] (a)
delivering the nacelle, tower sections and jacking crane over a
foundation platform or other foundation using a transport vehicle;
[0093] (b) lifting the nacelle onto the foundation platform or
foundation; [0094] (c) removing the transport vehicle; [0095] (d)
assembling crane and jacking crane; [0096] (e) extending the
jacking crane; [0097] (f) delivering tower sections to the
foundation platform or foundation using a transport vehicle; [0098]
(g) winching a first tower section from the transport vehicle using
crane; [0099] (h) sliding the first tower section into position
within the jacking crane using the crane; [0100] (i) supporting the
nacelle on the tower section whilst adjusting jacking crane to
provide clearance for one or more clamps; [0101] (j) attaching
clamps to securely and safely anchor jacking crane to tower; [0102]
(k) repeating steps (g) to (j) with further tower sections to erect
a tower; [0103] (l) mounting the nacelle on top of the tower; and
[0104] (m) mounting turbine blades on to the nacelle.
[0105] An embodiment of the present invention will now be described
by way of an example only, with reference to the following Figures,
in which:
[0106] FIG. 1 is a schematic view of the vessel in position next to
an foundation platform ready for the erection of the
self-installing tower in an offshore environment according to the
preferred embodiment of the present invention;
[0107] FIGS. 2 to 22 are schematic views showing installation of
the self-installing tower;
[0108] FIG. 23 is a schematic view of the self-installing tower
when installed and when ready for attachment of the turbine
blades;
[0109] FIGS. 24 to 30 are schematic views of the turbine blades
being attached to the self-installing foundation platform;
[0110] FIG. 31 shows a foundation platform with tower sections
attached being towed to an offshore location;
[0111] FIG. 32 shows the foundation platform of FIG. 31 after the
transportation vessel has left and being anchored in place;
[0112] FIGS. 33 and 34 show the nacelle and jacking crane being
loaded onto the foundation platform; and
[0113] FIGS. 35 to 46 show the tower being erected.
[0114] FIGS. 47 to 58 illustrate a method of erecting a wind
turbine system on an foundation platform or other foundation.
[0115] FIGS. 59 to 67 are schematic drawings of the framework and
jacking crane in position with the tower and tower sections.
[0116] The self-installing wind energy tower, with nacelle and
blades can be erected in an onshore and offshore position in a
first manner illustrated in FIGS. 1 to 14. The Figures illustrate
the apparatus in an offshore environment, although use in an
onshore environment is also possible. Referring firstly to FIG. 1,
in one embodiment, vessel 1 has a small crane 2 which is used to
lift the self installing tower, nacelle and blades onto an
installation (working) platform 3. The foundation platform will be
secured in position on the ocean bed 4, and tested prior to
construction of the remaining parts of the finished wind turbine.
The apparatus described in the present Application is particularly
adapted for erection on the foundation platform described in the
Applicant's co-pending UK Patent Application No 0206569.6 and
International Application No GB2003/001159. It is envisaged that
the apparatus described in the present invention is suitable for
use in both offshore and onshore locations. The apparatus brings
significant cost savings by eliminating the requirement for large
cranes, both onshore and offshore.
[0117] In the first step shown in FIG. 2 a jacking crane 5,
together with the nacelle 6 of the turbine is transferred onto the
foundation platform 3. The jacking crane acts as a motion
compensation system when it is initially transferred to the
platform with the nacelle on top. This effectively means that the
nacelle can be transferred from vessel 1 onto the foundation
platform ready for erection in poorer weather conditions (i.e.
worse sea states) than otherwise possible. Thus, offshore work will
not be disrupted.
[0118] One of the essential requirements for the jacking crane
herein described, is that it must have a secure and safe anchorage
to the tower. This ensures that the turbine is erected safely and
efficiently and allows cranes and other construction operations to
be supported from the frame.
[0119] The jacking crane, as illustrated in the diagrams, comprises
a frame supporting four legs (although the number of legs is not
limited to this) which can extend and retract. These are attached
to upper and lower grip assemblies that can be moved relative to
each other by the actuation of the jack legs. The grip assemblies
grasp the tower using arms that fit into pockets in the tower
sections. The top works of the device contains winches and a
trolley to mechanically handle the tower sections into place under
the nacelle for bolting to sections already in place.
[0120] The apparatus and method described in the present
Application may be used, not only to construct and erect new wind
turbine towers, but also to dismantle or carry out maintenance on
existing towers. Where the tower is new-build, purpose built
attachment points can be provided within the tower sections to
ensure anchorage of the jacking crane. However, where the tower is
already erected a secure anchorage may be provided either by using
fixed attachment points or without fixed attachment points.
[0121] In one embodiment a secure anchorage is provided by
employing one or more clamps that grip the tower sections by
compression and friction alone. Contact pads made of a compliant
material such as Polyurethane are brought into contact with the
tower section and pressure is applied sufficient to develop the
vertical frictional resistance necessary to support the desired
loads.
[0122] An important aspect of these clamps lies in the fact that
adjustment is provided within the clamps and support structure to
accommodate changes in the shape of the tower being climbed, and to
ensure verticality in the climbing frame at all times. The
adjustment should include as a minimum for the pronounced taper
currently employed in wind turbine tower designs.
[0123] The compliant pads may be mounted on a flexible backing
substrate that is tensioned at its ends. To allow for a more even
distribution of the loads imposed by the clamp, the flexible
substrate should contact the tower in a number of sections. In the
embodiment shown in FIGS. 47 to 58, four equal (quadrant) sections
are shown, although it will be appreciated that the number is not
restricted.
[0124] Each clamp is mounted on an arrangement of struts, ties and
beams that can be adjusted to accommodate changes in the tower
cross section, and that can be locked to provide a fail-safe
operation. Adjustment of the length of the flexible substrate can
be achieved by passing its ends around rollers or sprockets that
can rotate as the length is increased or decreased. Preferably
these sections of the flexible substrate comprise an arrangement of
links similar to the tracks of a tracked vehicle, and are also
covered with compliant material. An arrangement of screw-jacks
between the sprocket wheels of adjacent sections of flexible
substrate allows tension to be applied and the length of substrate
to be adjusted whilst allowing an efficient load path of hoop
tension within the flexible substrate/sprocket wheel system.
[0125] Further more the friction coefficient of the tower/clamp
interface can be improved by preparing the relevant sections of
tower with high-grip surfaces such as anti-slip paint and glue-on
grip strips.
[0126] A further safety feature which may be provided is the
inclusion of mechanical toothed wedges that can be activated as
necessary that engage by a wedging action between the tower and
climbing frame.
[0127] Once the jacking crane 5 and nacelle 6 are in position on
the foundation platform 3 the installation tower can be erected. An
important aspect of the present invention is that the tower is
supplied in manageable sections. These may be around 10 to 25
metres in length, and offshore can be transferred onto the
foundation platform in the same manner as the jacking system. As
the tower is supplied in sections the vessel 1 can be smaller than
conventionally used or proposed for offshore wind farm construction
as it will not have to carry or tow a large cumbersome, unitary or
two parts pre-made tower unit. As the decks of these vessels are
frequently very obstructed and congested in any event, this is a
significant advantage. A tower section 7 is transferred onto the
platform 3 and can be positioned within the jacking crane using
hydraulic means 8 as shown in FIGS. 6 and 7. Once first section 7
is in position, a second tower section 9 can be transferred onto
the foundation platform 3 as shown in FIG. 8.
[0128] A crane 10 in the nacelle 6 can be used to perform all the
lifting operation after the initial lift of the sections from
vessel 1. In a first embodiment this may be achieved by allowing
the nacelle 6 to rotate while it is temporarily installed on top of
the jacking crane 5. In an alternative embodiment a temporary boom
(not shown) is attached to the jacking crane 5. In either case the
winch 10 can be located within the nacelle 6. A boom may also be
required to enable the crane to reach over the side of the
foundation platform to be able to lift the tower sections (located
around the side of the foundation platform) and also the blades in
the supply boat. The boom may require a counterbalance. This can be
achieving using a seawater ballast, again removing the requirement
for a large lift.
[0129] The jacking crane 5 may simply be considered as a device for
safely climbing the tower as it is constructed from the tower
sections. In other words, the jacking crane climbs the tower during
construction. Initially it is used for installing tower sections as
shown in FIGS. 7 to 23. The jacking crane is also used to erect the
nacelle and then the blades 11 and 12 as shown in FIGS. 24 to 30.
Whilst the depicted embodiment uses two blades it will be
appreciated that the number of blades mounted on the tower is not
restricted to this. The jacking crane 5 moves up the tower as it is
erected and is used to install a section of the tower on top of
those section which have previously been installed, using the crane
10 of the nacelle 6, which lifts the sections up to the jacking
crane 5. The jacking crane 5 can subsequently be used for
inspection (e.g. non-destructive testing of the tower and blades to
look for cracks), painting, replacing parts (e.g. blades) and any
form of maintenance requiring access up the outside of the tower.
All these different activities will require specially designed
tools and lifting baskets that have a common interface so they can
simply by plugged into the jacking crane.
[0130] The jacking crane 5, is anchored and used to combine the
tower sections that make up the tower. The jacking crane 5 carries
a framework 35 such as an `A` frame (tool) or knuckle boom crane
(tool) capable of plumbing or reaching inside the nacelle 6 so as
to enable nacelle components to be removed for maintenance or to be
replaced completely. This is shown in FIGS. 59 to 61. In FIG. 59
the "A" frame has a runway beam which is plumbed over the nacelle
centreline.
[0131] In an alternative embodiment the jacking crane may carry an
`A` frame that is capable of lifting the assembled nacelle or of
lifting the largest sub assemblies of the nacelle such that the
nacelle is lifted after the tower is completed instead of being
carried by the jacking crane during installation of the tower
sections (as shown in FIG. 63). This alternative "A" frame
configuration can also be used for maintenance and it may need to
be extendible to allow removed components to be lowered passed to
back of the nacelle. This is shown in FIGS. 62 to 67.
[0132] The advantage of using an "A" frame to install the nacelle,
rather than lifting the nacelle with the jacking crane, is that it
allows for much longer hydraulic rams in the jacking unit. This is
because the "A" frame is much lighter than the nacelle and the
reduced buckling loads then allow greater extension, providing
sufficient clearance for full length tower sections to be
installed. It is likely that the tower will not need to be modified
significantly when compared with conventional tower installation
using a crane.
[0133] The tower sections themselves are typically air and
water-tight and in one embodiment suited to offshore applications
may actually be attached to the foundation platform 3 when it is
floated to position. In this manner they may be used to control
buoyancy--i.e. an integral part of the installation process. The
tower sections can be flooded when the platform has reached
location. This may aid installation of the platform by providing
added weight.
[0134] The jacking crane 5 has a fail-safe mechanism that prevents
it from becoming detached from the tower under construction and
falling. The jacking crane may also be used for maintenance
purposes and to provide welfare facilities for construction and/or
maintenance personnel.
[0135] The jacking crane can be connected to a variety of interface
tools and thus adapted for multiplicity. For example, the jacking
unit may be adapted to carry tools, which are used for inspection
and/or replacement of the blades, nacelle or tower sections. The
jacking crane may include an access platform and a variety of
tools.
[0136] It is also possible that the erection process described
herein can by automated to a significant degree. This may be
achieved using remote control and further improves safety and
reduces costs. The design of the self installing tower facilitates
maintenance and decommissioning works and thus is particularly
useful for inspecting blades and replacing if necessary.
[0137] In a second embodiment of the present invention, depicted in
FIGS. 31 to 46, tower sections 13 are pre-mounted or attached onto
an foundation platform 14, and towed into an offshore position by a
transportation vessel 15. In this embodiment, it is of a particular
advantage that the tower sections 13 are air and water-tight and
buoyant, and thus help transportation of the foundation platform to
its offshore position. Once the foundation platform has been towed
to its position, it is anchored 16 onto the seabed, and the
transportation vessel 15 will depart from the area. As the capital
and operational costs of these vessels make them hugely expensive,
it will be appreciated that this is a significant advantage over
existing methods.
[0138] In a preferred embodiment, the foundation platform is of the
type described in the Applicant's co-pending UK Patent Application
No 0206569.6 and International Application No GB2003/001159, and is
anchored to the ocean bed in the manner described in these earlier
Applications.
[0139] Referring to FIG. 33, once the foundation platform has been
anchored onto the seabed, a transportation vessel carrying the
jacking cranes 17 and nacelle 18 arrives. A transportation vessel
has a crane 19 which can be used to lift the jacking crane 17 and
nacelle 18 onto the foundation platform, as shown in FIG. 34. The
transportation vessel may then be removed, as shown in FIG. 35,
leaving the foundation platform with the entire apparatus required
to install a wind turbine. Erection of the wind turbine may be
fully operated and may be controlled by remote control.
Advantageously, the following steps can be carried out after the
transportation vessel 15 has been removed, thus greatly reducing
costs.
[0140] Referring now to FIGS. 36 to 46, the jacking crane 17 is
extended on the foundation platform 14, thereby lifting nacelle 18,
as shown in FIGS. 36 to 37. Nacelle 18 has a winch or crane 19
which is activated and used to winch up tower sections 20 and 21
from their location on the foundation platform 14, as shown in FIG.
38. From the position shown in FIG. 38, tower section 20 can be
moved into position within the jacking crane 17 and in the centre
of foundation platform 14 using hydraulic moving part 22, as shown
in FIG. 39. Once tower section 20 is in position on the foundation
platform within the jacking crane 17, the jacking crane can be
further extended, as shown in FIG. 40. The crane or winch 19 can
thereafter be used to winch up tower section 21, as shown in FIGS.
40 to 41, and then moved into position within the jacking crane 17
on top of first tower section 20 by a hydraulic moving part 22.
Thus, tower sections 20 and 21 are transferred into position within
the jacking crane 17, as shown in FIG. 42 to produce the beginning
of turbine tower 23.
[0141] This process can be repeated using further tower sections,
as shown at 24 and 25 in FIGS. 42 to 45, until the complete tower
23 is erected, as shown in FIG. 46. Following erection of the tower
23, the turbine blades can be erected in the manner previously
described.
[0142] It will be appreciated that whilst the depicted embodiment
for tower sections 20, 21, 24 and 25 are illustrated, the number of
tower sections is not limited to this.
[0143] It is also recognised that an alternative option is to load
or attach not only the tower sections, but also the jacking crane
and nacelle onto the foundation platform 14 before it is towed into
a location by transportation vessel 15. This will completely
eliminate the need for the transportation vessel to be present near
the foundation platform at any stage after the initial towing
process, and will greatly reduce costs. In this option, the size of
the foundation platform may be increased, or may comprise a
temporary extension to allow room for a drilling unit 26 to anchor
the platform, together with the remainder of the apparatus.
[0144] Referring now to FIGS. 47 to 58 a further method of
installing the apparatus described in the present invention on an
foundation platform or other foundation 27 is illustrated.
[0145] The nacelle 28, tower sections and jacking crane are
transported over an foundation platform or other foundation using a
transport vehicle 29 as shown in FIG. 47 and the nacelle is lifted
onto the foundation platform or other foundation. The transport
vehicle may then be removed. A crane 30 can then be assembled as
shown in FIGS. 50 and 51 for use in winching the tower sections
into position. The nacelle can the be temporarily supported whilst
the jacking crane 31 is assembled and/or placed in position, as
shown in FIG. 52. The jacking crane is then extended. The tower
sections can then be delivered to the foundation platform or
foundation using a transport vehicle, as shown in FIG. 53.
[0146] In order to erect the wind turbine tower a first tower
section 32 is winched from the transport vehicle using the crane
(FIG. 54). This section is then slid into position within the
jacking crane using the crane (FIG. 55). The first tower section
can thereafter be used to support the nacelle whilst the jacking
crane is adjusted to provide clearance blocks at 33 for one or more
clamps 34 which are used to safely and securely attach the jacking
crane to the tower. This is shown in FIGS. 56 and 57. This process
is then repeated with further tower sections to erect a tower
having the nacelle located at the top, on which turbine blades can
be mounted. In the example embodiment and outline procedure for
erecting a wind turbine is as follows: [0147] (a) The nacelle and
hub is delivered over the foundation (or assembled there if it is
very large) and the jacking crane is assembled around it using a
small site crane. [0148] (b) The jacks lift the nacelle off the
transporter or support platform to a height sufficient for the
onboard cranes to upend and insert a tower section directly beneath
the nacelle. [0149] (c) The jacks extend further to make space for
a second tower section, and the upper grippers engage with the top
of the first tower section. [0150] (d) The second section is
lifted, inserted, and bolted to the first. [0151] (e) The upper
grips now release and the jacks extend slightly so that the upper
grippers now engage with the bottom of the newly installed upper
tower section. [0152] (f) With the upper set of grippers locked,
the jacks contract to bring a bottom set of grippers to engage with
the top of the lower section of tower. [0153] (g) The top set of
grippers can now release and the jacking crane extends to make
space for the third tower section. The upper grips engage with the
top of the tower before the next section is fitted. [0154] (h) The
process repeats from step (c) until the tower is complete. [0155]
(i) When the tower is complete, the jacks lower the nacelle onto
the tower for bolting, and the onboard cranes lift the blades into
the hub for bolting.
[0156] It will be appreciated that there are fundamental
differences between the jacking crane and a conventional crane. A
conventional crane is optimised for flexibility, whilst the jacking
crane is designed for a specific task--to erect large wind
turbines. In practice this means: [0157] there is no need for a
road-going chassis--it only climbs towers. [0158] there is no need
for a slew capability. [0159] the hook is replaced by a transfer
carriage in the top-works of the jacking crane to provide precision
handling and mechanical control at all times.
[0160] An advantage of the jacking system herein described lies in
the fact that it can be used, not only to erect and disassemble
towers, but can also be used to climb existing towers for
maintenance. A particular advantage of the present invention lies
in the fact that the wind turbine can be erected in its entirety
(including the erection of the tower, nacelle and blades) in an
offshore location, without the requirement for a specialist vessel
is required to be in attendance. As a consequence lifetime costs
are greatly reduced. In addition the process has desirable
reversibility and thus the wind turbine can be removed, or the
blades, nacelle or indeed tower can be replaced if required. This
facilitates ongoing maintenance. The apparatus described herein and
in the Applicant's co-pending UK Application No 0206569.6 and
International Application No GB2003/001159 is also self sufficient,
in other words all of the delicate lifting and handling operations
are controlled from the already constructed structure. The vessel
may therefore deliver the jacking mechanism and the tower sections
and leave and does not need to remain in the area. Components are
landed onto the foundation platform in a conventional way, but from
there they are handled by handling equipment that is supported by
the already erected structure. This eliminates relative movement
(e.g. between vessel hook and structure) which makes the operation
safer and eliminates the requirement for massive offshore
cranes.
[0161] A further advantage is that erection of the self installing
turbine is inherently safer than convention methods because all of
the lifts are controlled and do not require high unsupported loads.
Thus the safety of the construction crew is ensured. The apparatus
brings significant cost savings by eliminating the requirement for
large cranes both on and offshore, and is less sensitive to weather
and geotechnical conditions. This is of particular advantage as
offshore work will not be disrupted by sea state (tide and waves or
wide).
[0162] A yet further important advantage lies in the use of one or
more clamps which ensure that the jacking crane is securely and
safely attached to the tower or tower sections. Other advantages
are inherent in the described apparatus as a low cost crane is
used, the tower sections are easier to handle and transport, the
cost and time of erection is minimised and the apparatus can also
be used for the maintenance of existing turbines, as well as
building new turbines.
[0163] Various modifications may be made to the invention herein
described, without departing from the scope thereof.
* * * * *