U.S. patent application number 13/125217 was filed with the patent office on 2011-08-18 for multi-panel wind turbine blade with improved joints on the trailing edge.
Invention is credited to Enrique Vidorreta Garcia.
Application Number | 20110200444 13/125217 |
Document ID | / |
Family ID | 42128292 |
Filed Date | 2011-08-18 |
United States Patent
Application |
20110200444 |
Kind Code |
A1 |
Garcia; Enrique Vidorreta |
August 18, 2011 |
MULTI-PANEL WIND TURBINE BLADE WITH IMPROVED JOINTS ON THE TRAILING
EDGE
Abstract
A multi-panel wind turbine blade with improved joints on the
trailing edge, with an aerodynamic profile with a leading edge (3),
a trailing edge (5) and pressure and suction sides (7, 9) between
the leading edge (3) and the trailing edge (5), where the
transversal section of the edges of the prefabricated panels (31,
41) laid out on the pressure and suction side have a variable
geometry on the trailing edge area (5) along the blade, with at
least a first section (21) of the blade including its tip, in which
the configuration of the edges of these panels (31, 41) includes
some co-operating flattened surfaces (33, 43; 34, 44; 35, 45) to
facilitate its adhesive bonding along the trailing edge (5). This
variable geometry includes the possibility of using a third panel
(51) on a blade section near to its root.
Inventors: |
Garcia; Enrique Vidorreta;
(Pamplona, ES) |
Family ID: |
42128292 |
Appl. No.: |
13/125217 |
Filed: |
October 26, 2009 |
PCT Filed: |
October 26, 2009 |
PCT NO: |
PCT/ES09/70458 |
371 Date: |
April 20, 2011 |
Current U.S.
Class: |
416/223R |
Current CPC
Class: |
F03D 1/0683 20130101;
Y02P 70/50 20151101; F05B 2230/23 20130101; Y02E 10/721 20130101;
Y02E 10/72 20130101; Y02P 70/523 20151101; F05B 2240/301 20130101;
F05B 2230/50 20130101 |
Class at
Publication: |
416/223.R |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 28, 2008 |
ES |
P200803063 |
Claims
1. A wind turbine blade with an aerodynamic profile with a leading
edge (3), a trailing edge (5) and pressure and suction sides (7, 9)
between the leading edge (3) and the trailing edge (5),
characterised by in at least a first section (21) of the blade,
including its tip, its rear part including at least a first
prefabricated panel (31) and on the pressure side and a second
prefabricated panel (41) on the suction side in which the
configuration of the edges of these first and second panels (31,
41) includes some co-operating flattened surfaces (33, 43; 34, 44;
35, 45) to facilitate its adhesive bonding along the trailing edge
(5).
2. A wind turbine blade according to claim 1, wherein the length of
this first section (21) of the blade ranging from 70% to 100% of
the length of the blade from its tip.
3. A wind turbine blade according to claim 2, wherein in a first
area (23) of this first section (21), with a length ranging from
33% to 100% of the length of this first section (21), the edge of
one these two panels (31, 41) having the configuration of the
trailing edge (5) of the blade and its flattened surface (33, 43)
situated on an offset notch and by the other panel (41, 31) having
its flattened surface (43, 33) situated on its edge.
4. A wind turbine blade according to claim 2, wherein in a first
area (25) of this first section (21), with a length ranging from
33% to 100% of the length of this first section (21), these
co-operating flattened surfaces (34, 44) being situated on the
edges of the first and the second panel (31, 41) so that the
trailing edge (5) is configured for connection, with one of the
edges thicker than the other.
5. A wind turbine blade according to claim 2, wherein in a second
area (27) of this first section (21), with a length ranging from
65% to 100% of the length of this first section (21), these
co-operating flattened surfaces (35, 45) being situated on the
edges of the first and the second panel (31, 41) so that the
trailing edge (5) is configured for connection.
6. A wind turbine blade according to claim 5, wherein one of the
edges of the first and second panel (31, 41) being thicker than the
other.
7. A wind turbine blade according to claim 2, wherein in a second
section (23) of the blade next to its root also including a third
prefabricated panel (51) that is joined to the edges of these first
and second panels (31, 41) on the trailing edge (5).
8. A wind turbine blade according to claim 7, wherein this third
prefabricated panel (51) being U shaped and by in this second
section (23) of the blade the edges of the first and second panel
(31, 41) having some co-operating flattened surfaces (37, 47) with
the wings (55, 57) of this third panel (51) to facilitate an
adhesive bonding between them.
9. A wind turbine blade according to claim 2, wherein in a second
section (23) of the blade near to its root, the flattened surface
(39, 49) of at least one of these two panels (31, 41) being
situated on an extension (61) folded on its edge to be joined to
the flattened surface (49, 39) of the other panel (41, 31).
10. A wind turbine blade according to claim 9, wherein this
extension (61) being L shaped so that this flattened surface (39,
49) is opposite the flattened surface (49, 39) of the other panel
situated on its edge to be able to carry out its adhesive
bonding.
11. A wind turbine blade according to claim 9, wherein the
flattened surface (49, 39) of the other panel also being situated
on an extension (63) folded on its edge, so that both extensions
(61, 63) face each other to carry out the adhesive bonding in a
transversal direction to the blade profile rope.
12. A wind turbine blade according to claim 11, wherein the
direction of these extensions (61, 63) forming an angle
.quadrature., ranging from 0.degree.-30.degree. with the direction
perpendicular to the blade rope.
13. A wind turbine blade according to claim 7, wherein the length
of this second section (23) of the blade ranging from 1% to 30% of
the its length measured from the blade's root.
Description
FIELD OF THE INVENTION
[0001] This invention generally refers to wind turbine blades and
more specifically to multi-panel blades with adhesive bondings on
the trailing edge.
BACKGROUND
[0002] Wind turbines include a rotor that supports one or several
blades that are spread out radially to capture the wind's kinetic
energy and cause a rotary movement of a power train connected to an
electric generator to produce electrical power.
[0003] The amount of energy produced by the wind turbines depends
on the blade rotor sweep surface that receives wind action, and
consequently, increasing the length of the blades normally implies
an increase in the wind turbine's energy production.
[0004] To facilitate the manufacturing of wind turbine blades the
division of the blade into several panels has been proposed that
can be manufactured individually perfectly and assembled later on
to make up the blade. Some of the proposals known are the
following.
[0005] EP 1 184 566 A1 describes a wind turbine blade that is made
up assembling one, two or more longitudinal sections, each of which
make up a central element made up by a longitudinal carbon fibre
tube on which a series of transversal carbon fibre or fibre glass
ribs are assembled connected to this central area and a carbon
fibre or fibre glass cover connected to these ribs.
[0006] WO 01/46582 A2 describes a wind turbine blade that has a
plurality of divided elements connected to the load transmission
box beam and separated by gaskets that allow these divided elements
movements between each other to minimise the traction forces in the
blade region where these divided elements are situated.
[0007] The current trend in the industry for wind turbines with
larger rotor blades requires new blade designs suitable for firstly
complying with transport and quality conditions set out by large
sized blades and secondly by the conditions set out by the
manufacturing processes with a view to obtaining the maximum degree
of automation.
SUMMARY OF THE INVENTION
[0008] An object of this invention is to provide a wind turbine
blade configuration that allows improving the control of the
geometry of the blade's trailing edge.
[0009] Another object of this invention is to provide a wind
turbine blade configuration that allows improving panel connection
on the trailing edge.
[0010] Another object of this invention is to provide a wind
turbine blade configuration that contributes to increasing the
robustness of panel connections on the trailing edge.
[0011] These and other objects of this invention are achieved
providing a wind turbine blade with an aerodynamic profile with a
leading edge, a trailing edge and pressure and suction sides
between the leading edge and trailing edge, the rear part of which
consists of at least a first prefabricated panel on the pressure
side and a second prefabricated panel on the suction side in which
the configuration of the edges of these first and second panels
includes flattened co-operating surfaces to facilitate its adhesive
bonding along the trailing edge.
[0012] In a preferred embodiment of this invention, the edge of one
of the two panels has the configuration of the trailing edge of the
blade and its flattened surface is situated on an offset notch and
on the other panel this flattened surface is situated on the edge.
In another embodiment, these flattened co-operating surfaces are
situated on the edges of the first and the second panel, and one of
them is considerably thicker than the other. These configurations
are suitable for the final section of the blade (although they may
extend along the entire blade, particularly in short length blades)
and allow improving the control of the geometry of the trailing
edge of the blade.
[0013] In a preferred embodiment of this invention, these
co-operating flattened surfaces are situated on the edges of the
first and second panel so that the trailing edge is configured for
connection, and both edges may have a similar thickness or one of
them be considerably thicker than the other. These configurations
are suitable for an intermediate section of the blade or near to
its root and allow improving the control of the geometry of the
blade's trailing edge.
[0014] In a preferred embodiment of this invention, in a section of
the blade near to the root, the rear part of the blade also
includes a third prefabricated panel that is joined to the edges of
these first and second panels on the trailing edge which allows
improving the control of the geometry of the blade's trailing edge,
particularly in very long blades. A similar result is obtained
equipping the first or second panel (or both) with flap shaped
extensions.
[0015] Other characteristics and advantages of this invention can
be inferred from the following detailed description regarding the
accompanying figures.
BRIEF DESCRIPTION OF FIGURES
[0016] FIG. 1 is a schematic view in transversal section of a
typical wind turbine blade.
[0017] FIGS. 2a and 2b are some schematic views in transversal
section of the prefabricated panels used to make up two multi-panel
blades.
[0018] FIG. 3 is a schematic view of a wind turbine blade according
to the preferred embodiment of this invention.
[0019] FIG. 4 is a schematic plant view of a blade according to
this invention showing the different areas and sections with a
different configuration on the trailing edge.
[0020] FIGS. 5a, 5b, 5c and 5d are partial views in transversal
section of the blade in FIG. 3 by the C-C plane showing four
possible variants of the embodiment of the invention.
[0021] FIGS. 6a, 6b and 6c are partial views in transversal section
of the blade in FIG. 3 by the B-B plane showing three possible
variants of the embodiment of the invention.
[0022] FIG. 7 is a partial view in transversal section of the blade
in FIG. 3 by the A-A plane showing a possible variant of the
embodiment of the invention.
[0023] FIGS. 8a, 8b, 8c and 8d are partial views in transversal
section of the blade in FIG. 3 by the A-A plane showing four
possible variants of the embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0024] FIG. 1 shows the typical aerodynamic profile of a wind
turbine blade with a leading edge 3, a trailing edge 5 and pressure
and suction sides 7, 9 between the leading edge 3 and the trailing
edge 5 and FIGS. 2a and 2b show two possible multi-panel
configurations.
[0025] In the case of FIG. 2a, the blade components are two
crossbeams 11, a front shell 12 and two rear shells 15 and 17 and
in the case of FIG. 2b the blade components are two crossbeams 11
and two shells 15, 17.
[0026] As is well known in the technique, a multi-panel blade has
several advantages:
[0027] It allows the use of different materials and/or
manufacturing processes and/or structural configurations for each
part of the blade according to its requirements, which optimises
the cost of the blade.
[0028] It makes quality control easier.
[0029] It allows the blade manufacturer to organise its plans
according to different criteria and subcontract the manufacturing
of any of the parts if this is necessary.
[0030] This invention is applicable to the multi-panel
configurations shown in FIGS. 2a and 2b and to any other
configuration that includes panels on the rear area analogous to
the shells 15, 17.
[0031] The basic idea of this invention is to configure the
geometry of the prefabricated panels on the trailing edge so that,
on the one hand, they include specific surfaces for making their
adhesive bonding easier, and on the other that allow guaranteeing
the required shape of the trailing edge. This implies that the
transversal section of the panels has a variable geometry along the
blade and that, even a third panel is used on a section of the
blade near to its root.
[0032] In this sense, and as illustrated in FIG. 4, two sections
21, 23 and, inside the section 21, two areas 25, 27, can be
distinguished that as we will detail below have the edges of their
panels with a different transversal section and each one may have a
different length (the white arrows in FIG. 4 mark the ranges they
move in).
[0033] In section 21, the length of which may range from 70% to
100% of the length of the blade, measured from its tip, the
trailing edge is made gluing the two flattened surfaces on the
edges of the panels 31, 41.
[0034] In area 25, the length of which may range from 33% to 100%
of the length of section 21, and in the embodiments shown in FIGS.
5a and 5b, the blade's trailing edge is made up by one of the two
panels 31, 41 to which the other panel 41, 31 is joined in an
offset notch, and the connection on the co-operating flattened
surfaces 33, 43 is made with the adhesive layer 29. In the
embodiments shown in FIGS. 5c and 5d, the co-operating flattened
surfaces 34, 44, that are joined with the adhesive layer 29, are
situated on the edges of the first and second panel 31, 41 so that
the trailing edge is configured by its joint, and the one of the
edges is thicker than the other.
[0035] In area 27, the length of which may range from 65% to 100%
of the length of section 21, and in the embodiment shown in FIG.
6a, the edges of the first and second panel 31, 41, with a similar
configuration, include some co-operating flattened surfaces 35, 45
on their edges to make it easier to joint them with the adhesive
layer 29, and the blade's trailing edge is demarcated by the edges
of the first and second panel 21, 31. In the embodiments shown in
FIGS. 6b and 6c, one of the edges of the panels 31, 41 is thicker
than the other.
[0036] In section 23 the length of which may range from 1% to 30%
of the length of the blade measured from the root, and in the
embodiment shown in FIG. 7, the blade's edge is configured with the
two rear panels 31, 41 and a third panel 51, that is U shaped with
some wings 55, 57 and a web that decreases in height towards the
tip of the blade (as can be seen in FIG. 3). The edges of the first
and second panel 31, 41 include some planed surfaces 37, 47
co-operating with the wings 45, 47 of the third panel 51 to
facilitate a joint between them with the adhesive layers 29. The
blade's trailing edge is thus demarcated by the third panel 51 and
by the ends of the first and second panel 31, 41.
[0037] Likewise, in section 23, and as shown in FIGS. 8a, 8b, 8c
and 8d, the blade's edge may be configured with the two panels 31,
41 including some flaps 61, 63 to make the flattened surfaces
necessary for connection with an adhesive layer 29.
[0038] In the embodiment shown in FIG. 8a the lower panel 31 is
spread on a L shaped folded flap 61 on which a flattened area 39
that co-operates with the flattened area 49 of the upper panel 41
is situated.
[0039] In the embodiment shown in FIG. 8b the upper panel 41 is
spread on a L shaped folded flap 61 on which a flattened area 49
that co-operates with the flattened area 39 of the lower panel 31
is situated.
[0040] In the embodiment shown in FIG. 8c the two panels 31, 41 are
spread on folded flaps 61, 63 on which the flattened surfaces 39,
49 are situated that are joined with the adhesive layer 29 forming
the direction of these flaps with the direction perpendicular to
the blade profile rope, and angle .OMEGA. that in a preferred
embodiment ranges from 0.degree.-30.degree.. FIG. 8d shows the
special case in which the direction of these flaps 61, 63 coincides
with the direction perpendicular to the blade profile rope, i.e.
when .OMEGA.32 0.degree..
[0041] As an expert in this field will well understand, the term
"co-operating flattened surfaces" used in the previous paragraphs
should be understood in the widest sense as some surfaces suitably
shaped for joints normally used in the wind industry and in
particular for adhesive bondings.
[0042] These flattened surfaces and the schematised geometry in the
Figures may be carried out in several ways, for example by
machining and surfacing the geometry or using counter moulds in
these areas of the parts.
[0043] The following advantages are worthy of mention among the
advantages of this invention regarding the previous technique:
[0044] Better assembly of the different panels to make the complete
blade, due to the greater control in the surfaces to be connected
and the adjacent geometry (lower tolerances).
[0045] Drastic reduction in the finishing phase (cutting surplus
material, polishing, reworks to obtain the correct aerodynamic
profile, reinforcing the trailing edge's joint).
[0046] Better control of the trailing edge's aerodynamic surface.
This better control allows reducing the noise made by the blade
(lower environmental impact) and also increasing the blade's
efficiency, which results in an increase of the wind turbine's
production under the same wind conditions.
[0047] The geometry shown in FIGS. 5a, 5b, 5c and 5d reduces the
concentration of stresses on the trailing edge, preventing
premature failures in the adhesive bonding that occur with the
current solution on the end part of the blade.
[0048] Although this invention has been described entirely in terms
of preferred embodiments, it is clear that could be introduced
modifications within its scope, not regarding the latter as limited
by the embodiments described above, rather by the following
claims.
* * * * *