Heating element, heating system and wind turbine rotor blade

Abstract

The utility model relates to a heating element, a heating system and a wind turbine rotor blade, the heating element is used for the wind turbine rotor blade, the heating element comprises two electric connecting pieces, the two electric connecting pieces are suitable for being connected to a power supply circuit of the wind turbine rotor blade, and the two electric connecting pieces are in a limited geometrical shape. And a heating element configured to be arranged on a specific surface area of the wind turbine rotor blade, the heating element being equipped with a position indicator adapted to be aligned with a leading edge of the wind turbine rotor blade. The utility model provides a heating element for a wind turbine rotor blade, which is easier to install.

Description

Technical Field

[0001] This utility model relates to heating elements, heating systems, and wind turbine rotor blades, and in particular, to a heating element for wind turbine rotor blades. Background Technology

[0002] EP 2 843 228 A1 discloses a wind turbine rotor blade with an electric heating system comprising a plurality of electric heating elements arranged on the outer surface of the wind turbine rotor blade. Each heating element has a carrier layer and heating conductors arranged in a zigzag pattern on the carrier layer between two opposite edges of the heating element. The heating elements can be manufactured as flexible preforms having different shapes adapted to corresponding surface areas of the wind turbine rotor blade being heated. These preforms are positioned, adhered to the outer surface of the wind turbine rotor blade, and connected to a power supply line. Utility Model Content

[0003] Therefore, the purpose of this invention is to provide a heating element for wind turbine rotor blades that is easier to install.

[0004] A heating element (10) for a wind turbine rotor blade (36) includes: two electrical connectors (16) adapted to be connected to a power supply line (48) of the wind turbine rotor blade (36), and a defined geometry configured to be disposed on a specific surface area of ​​the wind turbine rotor blade (36), the heating element (10) being equipped with a position indicator (24) adapted to be aligned with the leading edge (44) of the wind turbine rotor blade (36).

[0005] A heating system (46) comprising a set of heating elements (10) as described herein, the heating elements (10) being adapted to be placed side by side on a wind turbine rotor blade (36), wherein at least some of the heating elements (10) have different geometries from one another.

[0006] A wind turbine rotor blade (36) includes a heating system (46) as described herein, the wind turbine rotor blade (36) having an outer surface and a leading edge (44), wherein each heating element (10) is mounted on the outer surface such that its position indicator (24) is aligned with the leading edge (44).

[0007] The aforementioned problem is solved by a heating element for wind turbine rotor blades having the features described herein. The advantages of the utility model are pointed out herein.

[0008] Heating elements for wind turbine rotor blades have:

[0009] Two electrical connectors are suitable for connection to the power supply lines of wind turbine rotor blades, and

[0010] A defined geometry, configured to be arranged on a specific surface area of ​​a wind turbine rotor blade, wherein

[0011] The heating element is equipped with a position indicator to be aligned with the leading edge of the wind turbine rotor blades.

[0012] The heating element has a predetermined geometry. When arranged on a wind turbine rotor blade, the surface area of ​​the turbine rotor blade covered by the heating element can be heated by a heating current supplied by a power supply line to the wind turbine rotor blade, which is connected to two electrical connectors. The heating current then flows through the heating element, heating the heating element and the surface area it covers to remove accumulated ice and / or prevent ice formation on that surface area.

[0013] The heating element of this invention is equipped with a position indicator suitable for alignment with the leading edge of a wind turbine rotor blade. The position indicator can be a straight line that aligns with the leading edge along its entire length. However, at least two smaller markings, such as line segments, crosses, or dots, can also be used, each easily aligned with the leading edge. The position indicator enables the heating element to be positioned on a specific surface area of ​​the wind turbine rotor blade when it is installed onto the blade.

[0014] When designing heating systems for wind turbine rotor blades, the expected operating conditions of the blades are considered during the design phase to define requirements. The surface area to be heated by each heating element is specified, including the element's geometry and the required heating power. Installing the heating elements in the correct locations is crucial to achieving the desired heating effect. Any errors in element positioning can lead to ice buildup in areas receiving insufficient heating power or overheating and wasted energy in areas receiving more than the required power.

[0015] Installing heating elements onto wind turbine rotor blades presents challenges in arranging them in the desired locations because the elements are relatively large and flexible, and the surface areas on the wind turbine rotor blades where heating elements need to be placed are difficult to identify due to the size of the blades and the complex curvature of their surfaces.

[0016] In the field of wind turbine rotor blade manufacturing, it is known to use laser projection systems to indicate desired locations. For example, a laser projection system can indicate the desired location of the reinforcing material layer within a wind turbine rotor blade half-shell mold. The reinforcing material can then be precisely placed at the location indicated by the laser projection system. However, this positioning technique is complex and requires precise reference to the relationship between the laser projection system and the wind turbine rotor blade half-shell. Typically, a reference mark on the wind turbine rotor blade half-shell mold is identified using a laser projection system. This is a complex process and cannot be applied to mounting heating elements on the outer surface of already demolded wind turbine rotor blades, or to retrofit existing wind turbine rotor blades with heating systems.

[0017] This invention provides a simpler solution. It uses the leading edge of a wind turbine rotor blade as a reference on the wind turbine rotor blade. The leading edge can generally be visually identified as the bonding line between the wind turbine rotor blade housing components. For the purposes of this disclosure, it is not important whether this leading edge completely overlaps with the leading edge of the wind turbine rotor blade, which is more precisely defined in aerodynamic terms.

[0018] Based on visual recognition of the leading edge, it is easy to align the position indicator of the heating element with the leading edge, thereby placing the heating element in a specific surface area. If necessary, it may be necessary to place the heating element at a desired position relative to the longitudinal axis of the wind turbine rotor blade, which can be easily done, for example, by measuring the distance from the tip of the wind turbine rotor blade along the leading edge. Positioning the heating element in a direction perpendicular to the leading edge is more difficult, essentially along the chord of the section, and the relative angle between the heating element and the leading edge, clearly indicated by the position indicator and the relative position of the leading edge. Therefore, precisely mounting the heating element in a specific surface area is a relatively easy task.

[0019] In one aspect, the heating element includes a heating layer made of carbon fiber material. The heating layer can be a textile material, such as a fabric, including non-crimped fabrics. The carbon fibers can be unidirectional along the longitudinal direction of the heating element, but can also be arranged in different directions, for example, in biaxial or triaxial fabrics.

[0020] In one aspect, the heating element includes a carrier layer and heating conductors fastened to the carrier layer. In this aspect, the carrier layer may correspond to a specific surface area and provide the stability required to process the heating element. The heating conductors are fastened to the carrier layer so that the heating element can be mounted to the specific surface area substantially in one step. When the heating element is mounted to the specific surface area, the heating conductors are arranged in predetermined positions so that the distribution of heating power conforms to specifications. Multiple heating conductors can be used on the heating element. For example, a single heating conductor can be arranged in a zigzag pattern on the carrier layer to distribute heating power substantially over the entire specific surface area. In an alternative aspect, multiple heating conductors can be connected in parallel to two electrical connectors and can be fastened to the carrier layer such that each heating conductor covers a defined portion of the heating element.

[0021] In one aspect, the carrier layer comprises a fiber web. For this web, glass fiber can be used, for example, but any other fiber that provides the required stability can also be used. Preferably, these fibers are electrically insulating so that the heating current flows only through the heating conductor in a defined manner. The fiber web provides the required stability and shear stiffness, facilitating the handling of the heating element with low weight. The fiber web can also be mounted to wind turbine rotor blades using established techniques such as lamination and / or resin vacuum infusion.

[0022] In one aspect, the heating conductor is fixed to the carrier layer by stitching. During the stitching process, yarns with sufficient heat resistance, such as polyester or aramid, can be used.

[0023] In one aspect, the position indicator comprises yarn sewn to the heating element. In this way, a reliable position indicator for the heating element can be provided at low cost.

[0024] In one aspect, the position indicator comprises multiple rows of parallel stitching yarns. This contributes to good visibility of the position indicator, especially when using fine yarns. Specifically, the multiple rows of stitching yarns collectively form a strip with a width smaller than the mesh size of the carrier layer fiber web, wherein the strip is arranged within a single mesh in its width direction. This allows for the precise acquisition and maintenance of the position indicator's position on the heating element.

[0025] In one respect, the yarn color of the position indicator differs from the color of the carrier layer and / or the heating conductor and / or any other yarn color used on the heating element. This helps to make the position indicator easily visually identifiable even if the heating element has a complex structure with numerous stitches associated with securing the heating conductor to the carrier layer. A particularly preferred color scheme is the use of red yarn as the position indicator, which is clearly visible on the heating element and provides a good contrast to the background formed by the lamination of the typically green wind turbine rotor blades.

[0026] In one aspect, the heating element has length and width, with two connectors arranged near opposite edges of the heating element extending along the width direction, and a position indicator pointing to the line in the width direction. This design is particularly suitable for heating elements connected to power lines extending along the longitudinal direction of wind turbine rotor blades, one on the pressure side and the other on the suction side. The overall shape of the heating element can be rectangular or trapezoidal, with the edges also incorporating some curvature.

[0027] In one aspect, the line indicated by the position indicator is positioned at a predetermined length. This may correspond to the midpoint of the heating element, but it may also be an asymmetrical design, for example, where the surface area to be heated on the suction side is longer than that on the pressure side when measured from the leading edge, or vice versa.

[0028] In one aspect, the heating conductor comprises a metal heating wire. The cross-section of the metal heating wire and the resistance of the selected metal can be selected, for example, to provide the required heating power at a given supply voltage.

[0029] In one aspect, the heating conductor comprises a carbon fiber bundle. The carbon fiber bundle can be a roving. The cross-section can be selected to provide the desired electrical properties.

[0030] In one respect, the mesh size of the fiber web ranges from 1 mm to 10 mm. In particular, the mesh size can range from 2 mm to 6 mm. This is a good trade-off between stiffness and weight. Furthermore, this mesh size also helps to achieve the required accuracy in positioning the position indicator and securing the heating conductor to the fiber web, especially when the position indicator and securing are done by stitching.

[0031] This invention also relates to a heating system comprising a set of heating elements as described herein, wherein the heating elements are adapted to be arranged side-by-side on a wind turbine rotor blade, and wherein at least some of the heating elements have different geometries from one another. With such a heating system, the entire surface area of ​​the wind turbine rotor blade to be heated can be covered by a specific set of heating elements.

[0032] This invention also relates to wind turbine rotor blades comprising a heating system as described herein, wherein the wind turbine rotor blades have an outer surface and a leading edge, and each heating element is mounted on the outer surface with its position indicator aligned with the leading edge. When mounting the heating elements to the outer surface, the heating elements can be aligned with the leading edge of the wind turbine rotor blades by relying on their respective position indicators. The heating elements are then secured to the outer surface, for example, by bonding and / or by a vacuum infusion process.

[0033] This invention provides a heating element for wind turbine rotor blades that is easier to install. Attached Figure Description

[0034] The present invention will now be explained in more detail with reference to the accompanying drawings. The drawings show:

[0035] Figure 1 A schematic diagram of the heating element.

[0036] Figure 2 Figure 1 Enlarged segment A,

[0037] Figure 3 Figure 2 Enlarged section B,

[0038] Figure 4 Perspective view of wind turbine rotor blades.

[0039] Figure 5. Schematic cross-sectional view of wind turbine rotor blades, and

[0040] Figure 6 shows an enlarged section C of Figure 5. Detailed Implementation

[0041] Figure 1 The heating element 10 has a geometry defined by a width 12 and a length 14. Two electrical connectors 16 are arranged near opposite edges 18 of the heating element 10, which extends along the width direction. Along the length direction, the heating element 10 has two longitudinal edges 26.

[0042] The heating element 10 includes a carrier layer 20 having a defined geometry and a heating conductor 22 fastened to the carrier layer 20. The heating conductor 22 is arranged in a zigzag pattern on the carrier layer 20 so that when the heating element 10 is mounted to a wind turbine rotor blade, nearly the entire surface area of ​​the wind turbine rotor blade covered by the heating element 10 is supplied with sufficient heating power.

[0043] The heating element 10 also includes a position indicator 24, which forms a line across the width of the heating element 10. The line is arranged along the width direction.

[0044] The heating conductor 22 is formed of a metal heating wire. Each of the two ends of the heating conductor 22 is provided with an electrical connector 16.

[0045] Reference Figure 2 and Figure 3 The enlarged section shown is used to explain more details of the heating element 10. Figure 2In the image, the heating conductor 22 can be seen secured to the carrier layer 20 via various stitches 28 made using the first yarn. The position indicator 24 includes multiple parallel rows of stitching yarns 30. These rows of stitching yarns are implemented using a second yarn of a different color than the first yarn. The second color is also different from the colors of the heating conductor 22 and the carrier layer 20. Stitching the rows of yarns 30 does not interfere with the stitching of the heating conductor 22 to the carrier layer 20. The rows of yarns 30 can be stitched before or after the heating conductor 22 is secured to the carrier layer 20.

[0046] Figure 3 The further magnified view shows the internal structure of the carrier layer 20, formed by a rectangular pattern of fiber webs 32 made of glass fibers 32. The mesh size 34 of the fiber web is approximately 5 mm. It can be seen that all the multiple rows of stitching yarns 30 are placed within a single mesh. In other words, the multiple rows of stitching yarns 30 together form a strip with a width equal to or smaller than the mesh size 34.

[0047] Figure 4 The wind turbine rotor blade 36 shown has a blade root 38, a blade tip 40, a trailing edge 42, and a leading edge 44. A heating system 46 comprising multiple heating elements 10 is arranged along a section of the leading edge 44, extending from near the blade tip 40 toward a center point closer to the blade root over most of the wind turbine rotor blade length. The heating elements 10 are arranged side-by-side. The heating elements 10 are connected via electrical connectors 16 (… Figure 4 (Not shown) is connected to the first power supply line and the second power supply line 48, which extend along the length of the wind turbine rotor blade and terminate at the blade root 38.

[0048] Figure 5 shows a schematic cross-section of the wind turbine rotor blade 36 at its leading edge 44, with the two half-shells 50, 52 unfolded to show the arrangement of the heating elements 10. It can also be seen that the heating elements 10 have different geometries, each generally rectangular, and are arranged side-by-side with the longitudinal edges 26 of adjacent heating elements 10 abutting each other.

[0049] The enlarged view in Figure 6 shows the heating element 10 closest to the blade tip 40 in more detail. The carrier layer 20 and the heating conductor 22 fastened thereto can be seen. The position indicator 24 is aligned with the leading edge 44 of the wind turbine rotor blade 36.

[0050] List of reference numerals

[0051] 10 Heating elements

[0052] 12 width

[0053] 14 Length

[0054] 16 Electrical connectors

[0055] 18 Edge

[0056] 20. Carrier layer

[0057] 22 Heating conductor

[0058] 24 Position Indicators

[0059] 26 Edges

[0060] 28. Suture

[0061] 30 rows of sewing yarn

[0062] 32 Glass fiber

[0063] 34 mesh size

[0064] 36 Wind turbine rotor blades

[0065] 38. Leaf base

[0066] 40 Leaf tips

[0067] 42. Trailing edge

[0068] 44. Prelude

[0069] 46 Heating System

[0070] 48 Power supply lines

[0071] 50 Half-shell

[0072] 52 Half-shell

Claims

1. A heating element (10) for a wind turbine rotor blade (36), characterized in that, The heating element comprises: two electrical connections (16) which are adapted to be connected to a power supply line (48) of the wind turbine rotor blade (36), and a defined geometry which is configured to be arranged on a surface area of the wind turbine rotor blade (36), characterized in that the heating element (10) is equipped with a position indicator (24) which is adapted to be aligned with a leading edge (44) of the wind turbine rotor blade (36).

2. The heating element (10) as defined in claim 1, characterized in that The heating element comprises a heating layer made of a carbon fiber material.

3. The heating element (10) as defined in claim 1, characterized in that The heating element (10) comprises a carrier layer (20) and a heating conductor (22) which is fastened to the carrier layer (20).

4. The heating element (10) as defined in claim 3, characterized in that The carrier layer (20) comprises a fiber web.

5. The heating element (10) as defined in claim 4, characterized in that The heating conductor (22) is fixed to the carrier layer (20) by stitching.

6. The heating element (10) as defined in claim 4, characterized in that The position indicator (24) comprises a yarn which is connected to the heating element (10) by stitching.

7. The heating element (10) as defined in claim 6, characterized in that The position indicator (24) comprises a plurality of rows (30) of stitched yarns which are arranged in parallel.

8. The heating element (10) as defined in claim 6, characterized in that The color of the yarn of the position indicator (24) is different from the color of the carrier layer (20) and / or the color of the heating conductor (22) and / or the color of any other yarn used on the heating element (10).

9. The heating element (10) according to any one of claims 1 to 8, characterized in that The heating element (10) has a length (14) and a width (12), wherein the two electrical connections (16) are arranged near opposite edges (18) of the heating element (10) which extend in the width direction, and wherein the position indicator (24) indicates a line in the width direction.

10. The heating element (10) as defined in claim 9, characterized in that The line indicated by the position indicator (24) is arranged at a predetermined length position.

11. The heating element (10) according to any one of claims 3 to 8, characterized in that The heating conductor (22) comprises a metal heating wire.

12. The heating element (10) according to any one of claims 3 to 8, characterized in that The heating conductor (22) comprises a carbon fiber bundle.

13. The heating element (10) according to any one of claims 4 to 8, characterized in that The fiber web has a mesh size (34) in the range of 1 mm to 10 mm.

14. The heating element (10) as defined in claim 7, characterized in that The plurality of rows (30) of stitched yarns together form a strip which has a width which is smaller than the mesh size (34) of the fiber web, wherein the strip is arranged within a single mesh in its width direction.

15. A heating system (46) comprising a set of heating elements (10) according to any one of claims 1 to 13, characterized in that, The heating elements (10) are adapted to be placed side by side on the wind turbine rotor blade (36), wherein the geometry of at least some of the heating elements (10) differs from each other.

16. A wind turbine rotor blade (36) comprising a heating system (46) as claimed in claim 15, characterised in that The wind turbine rotor blade (36) has an outer surface and a leading edge (44), wherein each heating element (10) is mounted on the outer surface with its position indicator (24) aligned with the leading edge (44). The heating element (10) is adapted to be placed side by side on the wind turbine rotor blade (36), wherein the geometry of at least some of the heating elements (10) differs from each other. The wind turbine rotor blade (36) has an outer surface and a leading edge (44), wherein each heating element (10) is mounted on the outer surface with its position indicator (24) aligned with the leading edge (44).

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