Note: Descriptions are shown in the official language in which they were submitted.
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CA 02832246 2013-10-03
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English translation of the originally filed application
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Installation vehicle for a tidal power station and method for the operation
thereof
The invention relates to an installation vehicle for a tidal power plant, in
particular
for two-part plants, for which a nacelle having a turbine generator unit is
fastened
on a coupling device of a foundation part, which is supported against the
floor of
the body of water. Furthermore, a method for the operation of the installation
vehicle is specified.
Water turbines around which water flows freely are known for obtaining energy
from a current of a body of water. They were developed for power generation
from a flowing body of water or an ocean current, in particular a tidal
current, to
be able to dispense with erecting flood barriers. In one possible embodiment,
a
propeller-shaped water turbine is used, which drives an electric generator
arranged inside the nacelle.
For the efficient utilization of slower currents of bodies of water, water
turbines
having a large rotor diameter are required. This requirement results in a
complex
installation in particular in the case of a site in the ocean, so that
installation
vehicles adapted to the respective plan have been proposed. For example, EP 1
980 670 Al discloses a catamaran having an open central region, which is
dimensioned such that a tidal turbine can be guided through. In addition, a
gravity
foundation, to which the tidal turbine is coupled, is transported up to the
installation location on the bottom side of the catamaran. For the
installation, the
plant as a whole, i.e., the combination of tidal turbine and foundation part,
is
lowered from the catamaran, wherein the tidal turbine is guided through the
central opening. The high weight to be handled of the overall plant, to which
the
foundation part substantially contributes, is disadvantageous in this
installation
method. As a result, the installation vehicle must meet a high capacity load
requirement.
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To be able to install particularly large tidal power plants, it has been
proposed that
firstly the foundation be laid with a support structure on the floor of the
body of
water in a first step. A coupling device is provided on the support structure,
on
which the nacelle having the turbine-generator unit is fastenable. For this
purpose,
reference is made, for example, to WO 2002/066828 Al and WO 2004/015264 Al.
These documents disclose the placement of a nacelle having a coupling pin on a
tower-side coupling device implemented as a conical receptacle. The nacelle is
lowered on guide cables, which are stretched between the top part of the tower
and a water vehicle, which is used for the transport of the nacelle having the
turbine-generator unit.
Furthermore, GB 2437533 A and GB 2447514 B describe the installation of two-
part and multipart plants with the aid of a ship crane. This requires precise
maneuvering of the ship vehicle and stabilized crane systems to compensate for
wave movements. Both are complex for the mentioned large-scale plant parts, so
that special installation ships are necessary. In addition, the time window
usable
for the installation is narrowly limited, since placement of the plant
requires calm
weather conditions and a defined, weak incident flow.
To make a crane-based installation of a two-part plant easier, it is proposed
by DE
10 2008 032 625 B3 that a lifting device for a nacelle be equipped with a
foldable
apron, which encloses the tower in the face of the final approach to a
foundation
part and thus centers the lifting device in relation to the coupling device.
To be able to dispense with special installation vehicles, US 7,859,128 B2
proposes
designing a nacelle having a turbine-generator unit for a two-part plant
having a
positive buoyancy. For the installation, a cable connection is set up between
the
tower-side coupling device and the coupling counterpart on the nacelle, which
draws the nacelle to the coupling device. If the cable connection is guided at
the
end of the coupling pin and on the base of the conical receptacle of the
coupling
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device, automatic centering occurs upon retraction of the cable. This concept
has
the disadvantage of the design expenditure for the cable traction system,
which
remains on the plant. Furthermore, the buoyant components provided in the
nacelle require additional structural space.
Alternatively, disconnectable buoyancy aids can be used for the installation,
which
are described by US 3,633,369 und US 3,823,564. Floats are disclosed, which
are
used for the transport and the depositing of support frames for drilling
platforms.
Furthermore, a method for depositing heavy loads on the ocean floor is known
from GB 980,575. For this purpose, the pontoon used for the transport of the
load
is partially flooded and drawn with the aid of winches on an anchor system to
the
ocean floor. Placement without interfering wave influences is thus possible.
The invention is based on the object of specifying an installation vehicle for
components of tidal power plants, in particular for a nacelle having a turbine-
generator unit, and also a method for the operation thereof, which is not
influenced by weather and wave influences. The installation vehicle is to be
suitable for precise deposit and recovery of plants of different sizes.
The object is achieved by the features of the independent claims. A diving
device
is used as the installation vehicle, which receives a nacelle having a turbine-
generator unit for a tidal power plant by means of a controllable fastening
device.
The installation vehicle is connected by means of a supply and communication
line
to an above-water ship. This connection line does not absorb any load,
however,
so that the installation vehicle is decoupled from wind and wave influences on
the
water surface after the diving. For an alternative design, the supply line is
omitted
and the installation vehicle is operated as an energy-autonomous and remote
controllable unit.
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The installation vehicle comprises at least two floating devices having a
plurality of
ballast tanks, which are preferably implemented as streamlined, oblong units.
The
nacelle having the turbine-generator unit is held between the floating devices
by
means of a controllable fastening device by a support element, which produces
a
connection between the floating devices. According to the invention, a
detachable
coupling device is used for connecting the floating device to the support
element
and/or the support element comprises a device for size adaptation, which
allows
setting of the spacing of the floating devices. By way of this measure, the
installation vehicle according to the invention is adaptable to different
structural
sizes of the turbine-generator unit. The spacing between the lateral floating
devices is adapted by a replacement or a length change of the support element
such that the turbine-generator unit can be securely accommodated.
Accordingly,
an adaptation is performed as a function of the size and/or the weight of the
nacelle having the turbine-generator unit.
By setting the spacing of the floating devices and adapting the support
element,
which is used as a load-absorbing connection between the floating devices, an
installation vehicle adapted to the respective plant to be placed results, for
which
bending and torsion forces are reduced on the load-absorbing structures, in
particular the support element. Furthermore, the maneuverability and the
service
life are increased as a result of the reduced load.
For a refinement of the installation vehicle according to the invention, the
floating
devices are additionally adaptable in size. They preferably include a
plurality of
ballast tanks, which are arranged in a row and to each of which a device for
accommodating ballast water is assigned. The water inflow advantageously
occurs
against a continuously maintained internal pressure, to be able to ensure
rapid
blowout in case of emergency. To adapt the floating devices, they consist of
individual modules, wherein each module comprises at least one ballast tank.
Furthermore, a detachable connection, which is implemented as load-bearing,
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exists between adjoining modules. Replacing individual modules and adding
additional modules to lengthen an advantageously implemented floating device
is
thus possible.
5 The invention is explained hereafter on the basis of exemplary
embodiments and
illustrations in the drawings, in the individual figures:
Figure 1 shows an installation vehicle according to the
invention, which
accommodates a nacelle.
Figures 2a and 2b shows a top view of installation vehicles according to the
invention having a length-adapted support element, which
produces a connection between lateral floating devices.
Figure 3 shows the arrangement of ballast tanks for the floating device of
an
installation vehicle according to the invention.
Figure 4 shows a subsection in a sectional view of a modularly
constructed
floating device of an installation vehicle according to the invention.
Figure 1 shows an installation vehicle 1 according to the invention in
schematically
simplified form. It is used to accommodate a nacelle 2 having a turbine-
generator
unit 3, which can be placed by means of a coupling connecting piece 15 on a
foundation part (not shown in detail) of a tidal power plant. The nacelle 2 is
held
by a controllable fastening device 7 on a support element 8. The support
element
8 produces a connection between the arrangement in pairs of lateral floating
devices 4, 4.1, 4.2, with the aid of which the installation vehicle 1 dives in
a
controlled manner.
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Figure 3 shows the construction of a floating device 4 as a partial sectional
view.
Ballast tanks 5.1, , 5.8 arranged in a row, which are implemented as
streamlined on the ends of the floating device 4, are sketched. The ballast
tanks
5.1, ... , 5.8 are connected to a compressed air and control unit 16, which
separately sets the ballast water level in each individual ballast tank 5.1,
, 5.8.
By way of this measure, the location of the installation vehicle 1 under water
is
stabilized, wherein a weight compensation is executed in addition to the
setting of
the diving depth and the fixing of the horizontal location during the
depositing and
accommodation of the load.
Additional drive devices 6.1, ..., 6.4, which are preferably designed as
thrusters
aligned in the forward, transverse, and vertical directions, are used for the
control
of the installation vehicle 1. Alternatively, pivotable drives or steel
rudders can be
used.
The floating devices 4, 4.1, 4.2 represent substantial components for the
incident
flow resistance because of their structural size, in spite of a streamlined
design. By
way of the measure according to the invention, of designing the transverse
spacing between the lateral floating devices 4, 4.1, 4.2 as adaptable, an
installation vehicle 1 results having a transverse extension adapted for the
respective turbine-generator unit 3 of the nacelle 2 to be installed. As a
result, the
bending and torsion loads acting on the support element 8 are minimized, so
that
its service life increases. In addition, an installation vehicle 1 which is
more
maneuverable than an oversized floating aid arises due to the adaptation of
the
support element 8.
To adapt the transverse spacing between the floating devices 4, 4.1, 4.2, the
connection between the support element 8 and the floating devices 4, 4.1, 4.2
is
disconnectable. For this purpose, a detachable coupling device 9.1, 9.2 having
a
bolt connection 12 is used to implement this connection. This detachable
coupling
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device 9.1, 9.2 can be fastened on various fastening points 11.1, 11.2, 11.3,
11.4
on the support element 8, so that different spacings for the floating device
4, 4.1,
4.2 are settable on the support element 8.
Alternatively, the support element 8 can be replaced depending on the
installation
task. This embodiment is shown in Figures 2a and 2b. Figure 2a shows a first
support element 8.1, which sets a spacing d1 between the floating devices 4,
4.1,
4.2, which is less than the spacing d2 for an installation vehicle 1 adapted
to a
larger turbine-generator unit 3. For a further alternative embodiment, a
device for
size adaptation 10 can be provided on the support element 8, 8.1, 8.2. This
can
be an extension part or an extendable unit.
Figure 4 shows a refinement for an installation vehicle according to the
invention,
wherein the lateral floating device 4 has a modular structure. Modules 13.1,
13.2,
13.3 are sketched, which each accommodate a ballast tank 5.9, 5.10, 5.11. The
ballast tanks 5.9, 5.10, 5.11 themselves or a structure which encloses them
are
implemented as load-bearing, so that by arranging self-supporting modules
13.1,
13.2, 13.3 in a row, a size-adaptable floating device 4, 4.1, 4.2 results.
Therefore,
depending on the weight to be accommodated of the nacelle 2 provided for the
installation, the necessary overhang length in the longitudinal direction for
the
floating devices 4, 4.1, 4.2 can be set by the selection of the module number.
The
modules are coupled 13.1, 13.2, 13.3 by connection components 14, ..., 14.n,
which are reachable via access openings 18.1, 18.2, 18.3, 18.4.
Further embodiments of the invention are conceivable. The connection between
the floating devices 4, 4.1, 4.2 can be produced by a plurality of support
elements
8, 8.1, 8.2, wherein some of the elements can run diagonally in relation to
the
longitudinal axis of the installation vehicle predefined by the floating
devices 4,
4.1, 4.2, if the region provided for accommodating the turbine-generator unit
3
remains free. Furthermore, it is conceivable to implement the support elements
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8.1, 8.2 as a supporting frame or by means of a streamlined profile, to allow
improved installation under incident flow. The installation vehicle is
oriented such
that the longitudinal axis of the lateral floating devices 4, 4.1, 4.2 is
aligned as
parallel as possible to the incident flow. Additional fins or rudders can be
provided
accordingly for the transverse stabilization.
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List of reference numerals
1 installation vehicle
2 nacelle
3 turbine-generator unit
4, 4.1, 4.2 floating device
5.1, ..., 5.11 ballast tank
6.1, 6.2, 6.3, 6.4 drive device
7 controllable fastening device
8 support element
8.1 first support element
8.2 second support element
9.1, 9.2 detachable coupling unit
d1, d2 spacing
10 device for size adaptation
11.1, 11.2, 11.3, 11.4 fastening point
12 bolt connection
13.1, 13.2, 13.3 module
14.1, 14.2, ..., 14.n connection components
15 coupling connecting piece
16 compressed air and control unit
17 supply and control line
18.1, 18.2, 18.3, 18.4 access opening
