Patent Description:
Modern wind turbines continue to grow in size and be equipped with increasingly long wind turbine blades in order to increase the power production. As the blades get longer, transportation of such blades can be challenging or even impossible in some regions of the world. Navigating in complex terrain and in regions with poor infrastructure poses a challenge for transporting the long blades by road, and in some cases, there is a limit to the length of a blade that can be transported to the wind turbine site. A way of solving this challenge is by blade segmentation, whereby the blade is transported in two or more segments, and is later assembled on-site. A segmented blade offers several additional benefits. The investment into manufacturing assets for producing very long blades can be reduced and transportation cost can be reduced. Hence segmented blades have the potential of bringing sustainable clean wind energy to regions that would otherwise not be a possibility, and improve the business case and economic performance of wind farms located in areas where transportation is challenging.

A segmented blade can be joined or assembled in various different ways, such as by means of bolted joint connections, adhesive joints, joining by lamination etc. These methods of joining are well known and proven from many applications in e.g. automotive, aerospace, and even within wind turbine blade design. However, implementation of these joining strategies are not well proven, and are not widespread in the application of segmented blades. This is strongly influenced from the fact that, although segmented blade concepts have existed in theory for decades, actual implementation and industrialization is limited within the wind industry. The increased technical complexity and derived cost increase of the blade has historically not favoured segmented blade design. But as the development of ever increasing rotor size for wind turbines in complex terrain is accelerating, this picture is starting to change. The need for segmented blades is emerging rapidly, having positive impact on the economy of certain wind projects. Hence, development and application of mechanical joints for segmented blades are an emerging technology, where mechanical joint technologies will be applied in new and innovative solutions.

An example of a prior art system can be found in <CIT>.

Some embodiments of the present invention provide a joint for a segmented wind turbine blade, a segmented wind turbine blade and a method for manufacturing a segmented wind turbine blade.

In one aspect, a joint for a segmented wind turbine blade is provided. The joint comprises a laminate glove integrally formed on a first blade segment of the segmented wind turbine blade, and a protruding laminate integrally formed on a second blade segment of the segmented wind turbine blade. The laminate glove is configured for housing the protruding laminate, and when the segmented wind turbine blade is assembled on-site, the laminate glove and the protruding laminate are connected together so that the first blade segment is assembled with the second blade segment. In a particular embodiment, the laminate glove has an outer glove laminate and an inner glove laminate, and the protruding laminate is located between the outer glove laminate and the inner glove laminate. In a particular embodiment, the protruding laminate is tapered in a spanwise direction of the segmented wind turbine blade, and the outer glove laminate and the inner glove laminate form a tapered glove opening for housing the tapered protruding laminate. In a particular embodiment, the joint comprises the laminate gloves respectively formed on a suction side and a pressure side of the first blade segment, and the protruding laminates respectively formed on a suction side and a pressure side of the second blade segment, and wherein the laminate glove on the suction side is configured for housing the protruding laminate on the suction side, and the laminate glove on the pressure side is configured for housing the protruding laminate on the pressure side. In a particular embodiment, the laminate glove and the protruding laminate are connected by adhesive or resin; or the laminate glove and the protruding laminate are connected by mechanical fasteners.

In another aspect, a segmented wind turbine blade is provided. The segmented wind turbine blade comprises at least two blade segments and one or more joints. The at least two blade segments comprises a first blade segment and a second blade segment. The one or more joints are configured for connecting the first blade segment and the second blade segment. Each of the one or more joints comprises a laminate glove integrally formed on the first blade segment, and a protruding laminate integrally formed on the second blade segment. The protruding laminate is housed in and connected with the laminate glove so that the first blade segment and the second blade segment are assembled together. In a particular embodiment, the joint is positioned at any given desired spanwise location of the segmented wind turbine blade; or the joint is positioned at any given desired chordwise location of the segmented wind turbine blade; or the joint is positioned in any given desired orientation in a cross section of the segmented wind turbine blade.

In still another aspect, a method for manufacturing a segmented wind turbine blade is provided. The segmented wind turbine blade at least comprising a first blade segment and a second blade segment. The method comprises steps of: laying up one or more material layers in a blade mold, the one or more material layers comprising a laminate glove of the first blade segment and a protruding laminate of the second blade segment, the laminate glove housing the protruding laminate; co-infusing the one or more material layers together in the blade mold so as to form a single-piece wind turbine blade; demolding the single-piece wind turbine blade from the blade mold; and separating the laminate glove from the protruding laminate to form the first blade segment with the laminate glove and the second blade segment with the protruding laminate so that the segmented wind turbine blade is formed, and the first blade segment and the second blade segment are able to be reassembled together by connection of the laminate glove and the protruding laminate when the segmented wind turbine blade is assembled on-site. In a particular embodiment, the laminate glove has an outer glove laminate and an inner glove laminate, and the protruding laminate is located between the outer glove laminate and the inner glove laminate. In a particular embodiment, the laying up the one or more material layers comprises: wrapping the inner glove laminate onto the protruding laminate prior to co-infusion. In a particular embodiment, the method further comprising adding between the laminate glove and the protruding laminate, a processing material for facilitating disassembly of the laminate glove and the protruding laminate during laying up the one or more material layers; or adding between the laminate glove and the protruding laminate, a processing material for facilitating disassembly of the laminate glove and the protruding laminate during laying up the one or more material layers, and covering the protruding laminate with the processing material. In a particular embodiment, the method further comprising removing the processing material from the protruding laminate before re-assembly. In a particular embodiment, the blade mold comprises two mold halves, and the laying up the one or more material layers in the blade mold and the co-infusing the one or more material layers together in the blade mold comprises: laying up and co-infusing the one or more material layers respectively in the two mold halves so as to form a suction side blade shell and a pressure side blade shell respectively, wherein the laminate glove and the protruding laminate are placed in each of the two mold halves. In a particular embodiment, the method further comprising: closing the two mold halves; and assembling the suction side blade shell and the pressure side blade shell together to form the single-piece wind turbine blade. In a particular embodiment, the co-infusing the one or more material layers together in the blade mold comprises: co-infusing the one or more material layers together with a liquid resin in the blade mold so as to cure the one or more material layers.

To describe the technical solutions in embodiments of the present disclosure more clearly, drawings in descriptions of the embodiments of the present disclosure will be briefly introduced below. It is apparent that the drawings described below are merely some embodiments of the present disclosure and other drawings may be obtained by those of ordinary skill in the art based on these drawings without resorting to creative labor.

The technical solutions of embodiments of the present disclosure will be described clearly and fully below in combination with drawings in the embodiments of the present disclosure. It is apparent that the described embodiments are merely part of embodiments of the present disclosure rather than all the embodiments. Other embodiments achieved by those of ordinary skill in the art based on the embodiments in the present disclosure without paying creative labor shall all fall within the protective scope of the present disclosure.

<FIG> illustrates a schematic view of a segmented wind turbine blade <NUM> according to one embodiment of the present disclosure. Referring now to <FIG>, the segmented wind turbine blade <NUM> according to one embodiment of the present disclosure may include at least two blade segments and one or more joints <NUM> for connecting the at least two blade segments. The at least two blade segments may include for example, but be not limited to a first blade segment <NUM> and a second blade segment <NUM>. The one or more joints <NUM> is used for the segmented wind turbine blade <NUM> and is configured for connecting the first blade segment <NUM> and the second blade segment <NUM>. Thus, by the one or more joints <NUM>, the first blade segment <NUM> and the second blade segment <NUM> of the segmented wind turbine blade <NUM> can be assembled together, thereby enabling transportation of the wind turbine blade <NUM> in segments, and for the segments to be assembled on-site.

The first blade segment <NUM> of the segmented wind turbine blade <NUM> includes one of a blade root segment and a blade tip segment, and the second blade segment <NUM> of the segmented wind turbine blade <NUM> includes the other of the blade root segment and the blade tip segment. For example, in one embodiment, the first blade segment <NUM> may include a blade root segment, and the second blade segment <NUM> may include a blade tip segment. In another embodiment, the first blade segment <NUM> may include the blade tip segment, and the second blade segment <NUM> may include the blade root segment.

However, it is noted that the segmented wind turbine blade <NUM> of the present disclosure should be not limited to include only two blade segments. In other embodiments, the segmented wind turbine blade <NUM> of the present disclosure may also include three, four or even more blade segments. The number of the segmented wind turbine blade <NUM> of the present disclosure may vary from two to any desired number. Furthermore, the segmented wind turbine blade <NUM> of the present disclosure should be not limited to include the blade root segment and the blade tip segment. In other embodiments, the segmented wind turbine blade <NUM> of the present disclosure may also include one or more medium blade segments located between the blade root segment and the blade tip segment.

<FIG> illustrates a cross-sectional view of the segmented wind turbine blade <NUM> of <FIG> taken along line A-A. <FIG> illustrates a cross-sectional view of the segmented wind turbine blade <NUM> of <FIG> taken along line B-B. As shown in <FIG> and <FIG>, each joint <NUM> may include a laminate glove <NUM> and a protruding laminate <NUM>. The laminate glove <NUM> is configured for housing the protruding laminate <NUM>. The laminate glove <NUM> has the size and the shape so to fit the protruding laminate <NUM>. In one embodiment, the laminate glove <NUM> and the protruding laminate <NUM> of the joint <NUM> are co-infused during manufacturing of the segmented wind turbine blade <NUM>.

<FIG> illustrates a schematic view of a portion of a first blade segment <NUM> of one embodiment according to the present disclosure. As shown in <FIG>, the laminate glove <NUM> of the joint <NUM> is integrally formed on the first blade segment <NUM> of the segmented wind turbine blade <NUM>. The laminate glove <NUM> is as an integral part of the first blade segment <NUM>. <FIG> illustrates a schematic view of a second blade segment <NUM> according to one embodiment of the present disclosure. As shown in <FIG>, the protruding laminate <NUM> of the joint <NUM> is integrally formed on the second blade segment <NUM> of the segmented wind turbine blade <NUM>. The protruding laminate <NUM> is as an integral part of the second blade segment <NUM>.

When the segmented wind turbine blade <NUM> is required to be assembled on-site, the laminate glove <NUM> may house the protruding laminate <NUM> and the laminate glove <NUM> and the protruding laminate <NUM> may be connected together by various connecting methods so that the first blade segment <NUM> is assembled with the second blade segment <NUM>. The joint <NUM> of the present disclosure may realize disassembly for transportation of the wind turbine blade <NUM> and re-assembly on-site for installation.

Referring now to <FIG>, in some embodiments, the laminate glove <NUM> of the joint <NUM> may have an outer glove laminate <NUM> and an inner glove laminate <NUM>. The protruding laminate <NUM> of the joint <NUM> may be located between the outer glove laminate <NUM> and the inner glove laminate <NUM> of the laminate glove <NUM>. Therefore, the protruding laminate <NUM> may be housed in the laminate glove <NUM>. When re-assembly, in one embodiment, the laminate glove <NUM> and the protruding laminate <NUM> may be connected together by adhesive or resin. The adhesive or the resin may act as a load transferring mechanism between the laminate glove <NUM> and the protruding laminate <NUM>. In another embodiment, the laminate glove <NUM> and the protruding laminate <NUM> may define one or more holes (not shown) for mechanical fasteners, and the laminate glove <NUM> and the protruding laminate <NUM> may be connected together by the mechanical fasteners.

In some embodiment, the protruding laminate <NUM> is tapered in a spanwise direction D1 of the segmented wind turbine blade <NUM>, and correspondingly, the outer glove laminate <NUM> and the inner glove laminate <NUM> of the laminate glove <NUM> form a tapered glove opening <NUM> for housing the tapered protruding laminate <NUM>. Such a tapered mating structure of the laminate glove <NUM> and the protruding laminate <NUM> can facilitate disassembly of the laminate glove <NUM> and the protruding laminate <NUM>.

In some embodiment, the segmented wind turbine blade <NUM> may include the one or more joints <NUM> on a suction side (SS) and the one or more joints <NUM> on a pressure side (PS). In the figures of the present disclosure, one joint <NUM> on the suction side and one joint <NUM> on the pressure side are shown as an example. Each joint <NUM> on the suction side includes the laminate glove <NUM> formed on a suction side of the first blade segment <NUM> and the protruding laminate <NUM> formed on a suction side of the second blade segment <NUM>. The laminate glove <NUM> on the suction side is configured for housing the protruding laminate <NUM> on the suction side so as to create a load transferring joint connecting the first blade segment <NUM> and the second blade segment <NUM> on the suction side. Each joint <NUM> on the pressure side includes the laminate glove <NUM> formed on the pressure side of the first blade segment <NUM> and the protruding laminate <NUM> formed on the pressure side of the second blade segment <NUM>. The laminate glove <NUM> on the pressure side is configured for housing the protruding laminate <NUM> on the pressure side so as to create a load transferring joint connecting the first blade segment <NUM> and the second blade segment <NUM> on the pressure side.

The joint <NUM>, i.e. the laminate glove <NUM> and the corresponding protruding laminate <NUM> may be positioned at any given desired spanwise location of the segmented wind turbine blade <NUM>, and the joint <NUM> may be positioned at any given desired chordwise location of the segmented wind turbine blade <NUM>. The joint <NUM> may also be positioned in any given desired orientation in a cross section of the segmented wind turbine blade <NUM>. The segmented wind turbine blade <NUM> may include a plurality of joints <NUM> in a cross-section. The plurality of joints <NUM> may be positioned in any desired pattern or spacing sequence in a given cross section. That is to say, the first blade segment <NUM> may include one or more laminate gloves <NUM>, and the second blade segment <NUM> may include one or more corresponding protruding laminates <NUM>.

The segmented wind turbine blade <NUM> of the present disclosure adopts the joint <NUM> with the laminate glove <NUM> fitting the protruding laminate <NUM> and may be thus disassembled for transportation and re-assembled on-site for installation.

The segmented wind turbine blade <NUM> of the present disclosure is completely scalable in the number of connections per joint <NUM>. The segmented wind turbine blade <NUM> of the present disclosure is completely scalable in dimensions, positioning, and orientation.

The present disclosure further provides a method for manufacturing the segmented wind turbine blade <NUM> above-mentioned. <FIG> illustrates a flow chart of a method for manufacturing the segmented wind turbine blade <NUM> according to one embodiment of the present disclosure. As described above, the segmented wind turbine blade <NUM> at least includes the first blade segment <NUM> and the second blade segment <NUM>. As shown in <FIG>, a method for manufacturing the segmented wind turbine blade <NUM> according to one embodiment of the present disclosure may include steps S11 to S14.

In step S11, one or more material layers are laid up in a blade mold. The one or more material layers include the laminate glove <NUM> of the first blade segment <NUM> and the protruding laminate <NUM> of the second blade segment <NUM>. The laminate glove <NUM> of the first blade segment <NUM> houses the protruding laminate <NUM> of the second blade segment <NUM>.

The one or more material layers may include one or more fiber layers. The one or more fiber layers may include at least one of glass fiber layers and carbon fiber layers. Optionally, the one or more material layers may further include one or more core material layers made of polymer foam or balsa wood.

In step S12, the one or more material layers are co-infused together in the blade mold so as to form a single-piece wind turbine blade <NUM>. For example, the one or more material layers are co-infused together with a liquid resin in the blade mold so as to cure the one or more material layers.

In step S13, the single-piece wind turbine blade <NUM> is demolded from the blade mold.

In step S14, the laminate glove <NUM> is separated from the protruding laminate <NUM> to form the first blade segment <NUM> with the laminate glove <NUM> and the second blade segment <NUM> with the protruding laminate <NUM> so that the segmented wind turbine blade <NUM> is formed, and the first blade segment <NUM> and the second blade segment <NUM> are able to be reassembled together by connection of the laminate glove <NUM> and the protruding laminate <NUM> when the segmented wind turbine blade <NUM> is assembled on-site.

The method of the present disclosure may manufacture the segmented wind turbine blade <NUM> in a non-segmented blade mold with the co-infused laminate glove <NUM> fitting the protruding laminate <NUM>, which can be subsequently disassembled for transportation and re-assembled on-site for installation.

By manufacturing the segmented wind turbine blade <NUM> in a non-segmented blade mold, the method of the present disclosure enables a unique elimination of tolerance chains, elsewhere causing difficulties of aligning segments for assembly on-site.

The method of the present disclosure does not incur additional capital expenditures on manufacturing as the non-segmented blade mold is utilized.

In some embodiment, the laminate glove <NUM> has an outer glove laminate <NUM> and an inner glove laminate <NUM> as shown in <FIG>, and the protruding laminate <NUM> is located between the outer glove laminate <NUM> and the inner glove laminate <NUM>. Thus, the laying up the one or more material layers of step S11 may include: wrapping the inner glove laminate <NUM> onto the protruding laminate <NUM> prior to co-infusion.

The laminate glove <NUM> and the protruding laminate <NUM> are co-infused in the blade mold. The laminate glove <NUM> and the protruding laminate <NUM> are processed in such a specific way, which enables disassembly of the two elements subsequent to demolding, and for re-assembly after transportation to the wind farm site. Thus, the method of the present disclosure may further include: adding between the laminate glove <NUM> and the protruding laminate <NUM>, a processing material for facilitating disassembly of the laminate glove <NUM> and the protruding laminate <NUM> during laying up the one or more material layers of step S11. In an optional embodiment, the adding the processing material between the laminate glove <NUM> and the protruding laminate <NUM> may include: covering the protruding laminate <NUM> with the processing material.

The processing material of the present disclosure may have the characteristics of surface tension and bonding characteristics, which enables disassembly of the protruding laminate <NUM> and the laminate glove <NUM>. Hence making possible for having such the segmented wind turbine blade <NUM>, which can be re-assembled. For example, the processing material may include Teflon.

In some embodiments, the method of the present disclosure may further include: removing the processing material from the protruding laminate <NUM> before re-assembly.

In one embodiment, the blade mold for manufacturing the segmented wind turbine blade <NUM> according to the present disclosure may include two mold halves. Thus, in step S11 and step S12, the one or more material layers may be laid up and co-infused respectively in the two mold halves so as to form a suction side blade shell and a pressure side blade shell respectively. The laminate glove <NUM> and the protruding laminate <NUM> are placed in each of the two mold halves. Therefore, the laminate glove <NUM> and the corresponding protruding laminate <NUM> on the suction side, as well as the laminate glove <NUM> and the corresponding protruding laminate <NUM> on the pressure side are formed.

In this case, the method of the present disclosure may further include: closing the two mold halves; and assembling the suction side blade shell and the pressure side blade shell together to form the single-piece wind turbine blade <NUM>.

The method of the present disclosure can manufacture the segmented wind turbine blade <NUM> in a blade mold in a single piece, and can be demolded in a single piece. Thus, the method of the present disclosure has a lower manufacturing cost.

Claim 1:
A joint (<NUM>) for a segmented wind turbine blade (<NUM>), comprising:
one or more scarfed laminate gloves (<NUM>) integrally formed on a first blade segment (<NUM>) of the segmented wind turbine blade, wherein the one or more scarfed laminate gloves (<NUM>) are arranged along a chordwise direction of the first blade segment (<NUM>), and the one or more scarfed laminate gloves (<NUM>) are inside the first blade segment (<NUM>); and
one or more scarfed protruding laminates (<NUM>) integrally formed on a second blade segment (<NUM>) of the segmented wind turbine blade, wherein the one or more scarfed protruding laminates (<NUM>) are arranged along the chordwise direction of the second blade segment (<NUM>), and the one or more scarfed protruding laminates (<NUM>) protrude from the second blade segment (<NUM>),
wherein the one or more scarfed laminate gloves are configured for housing the one or more scarfed protruding laminates, and when the segmented wind turbine blade is assembled on-site, the one or more scarfed laminate gloves and the one or more scarfed protruding laminates are connected together so that the first blade segment is assembled with the second blade segment.