Heating system for wind turbine rotor blade
By designing a heating system on the wind turbine rotor blades and utilizing a specific arrangement of the carrier layer and heating conductors, flashover is prevented and installation is simplified, solving the flashover problem of the heating system in the prior art during lightning strikes and achieving reliable lightning protection and uniform heating.
Patent Information
- Application Number
- CN202422593851.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Priority Date
- 2024-09-16
- Filing Date
- 2024-10-25
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2034-10-25
Smart Images
Figure CN223330727U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a heating system for wind turbine rotor blades. Background Art
[0002] EP2667025A1 discloses a wind turbine rotor blade with a heating mat having two sections arranged parallel to each other in the longitudinal direction of the wind turbine blade. To prevent short circuits between the two sections, a layer of insulating material is placed between adjacent sections, with the layer being arranged below one of the two sections and above the adjacent section.
[0003] EP2843228A1 discloses a wind turbine rotor blade with an electric heating system. The heating system comprises multiple electric heating elements arranged on the outer surface of the wind turbine rotor blade. Each heating element comprises a carrier layer and a heating conductor arranged in a meandering pattern on the carrier layer between two opposing edges of the heating element. The heating elements are arranged on the outer surface of the wind turbine rotor blade. The free end of each heating conductor is connected to two power supply lines that run along the length of the blade and also serve as lightning down conductors. In the event of a lightning strike, the heating elements are designed to provide potential equalization between the two down conductors. Utility Model Content
[0004] In view of the above, an object of the present invention is to provide a heating system for a wind turbine rotor blade and a related method, which heating system is easy to install on the outer surface of a wind turbine rotor blade while providing improved lightning strike protection.
[0005] This object is solved by the following heating system. Various aspects of the invention are given in the dependent claims.
[0006] The heating system is designed for a wind turbine rotor blade having a blade root, a blade tip, a suction side, a pressure side, a first power supply line arranged on the suction side, a second power supply line arranged on the pressure side, and an outer surface. The heating system comprises:
[0007] a plurality of heating elements adapted to be mounted in a row at defined operating positions on the outer surface of a wind turbine rotor blade in a longitudinal direction thereof,
[0008] wherein each heating element comprises a carrier layer and a heating conductor fixed to the carrier layer,
[0009] wherein the heating conductor has a first end adapted to be connected to a first power supply line and a second end adapted to be connected to a second power supply line,
[0010] Wherein, when the heating element is arranged in the defined operating position, each carrier layer has a first edge facing the blade tip and a second edge facing the blade root, characterized in that:
[0011] The carrier layer has a strip-shaped edge portion with a first width along the first edge and a strip-shaped edge portion with a second width along the second edge,
[0012] When the heating elements are arranged in the defined operating position, for each pair of adjacent heating elements, a first edge of one of the heating elements of the pair is arranged adjacent to a second edge of the other heating element of the pair, and
[0013] The first width and the second width are sized to arrange the heating conductors of the pair of heating elements at a predetermined distance sufficient to prevent flashover between the heating conductors.
[0014] A wind turbine rotor blade has an outer surface corresponding to an aerodynamic surface of the wind turbine rotor blade. The wind turbine rotor blade may comprise a shell structure forming the outer surface, such as two turbine rotor blade half shells, such as a pressure side half shell and a suction side half shell.
[0015] The heating system provides heating power via first and second power supply lines, which are arranged on the pressure side and the suction side, respectively. The heating system includes a plurality of heating elements, each of which is connected to two power supply lines.
[0016] Each heating element is designed to be arranged in a specific area of the outer surface of a wind turbine rotor blade. The geometry of the heating element generally corresponds to this surface area. This surface area is referred to as the defined operating position of the heating element. The geometry can be rectangular or trapezoidal, for example, with straight or curved edges. The heating elements can have the same geometry or different geometries. Heating elements are generally flat, flexible components and are therefore sometimes also called heating mats. The heating elements are suitable for installation in rows along the longitudinal direction of the wind turbine rotor blade. The heating elements are arranged side by side so that a relatively large, coherent surface area can be covered and heated by multiple heating elements.
[0017] The heating element can be fixed to the outer surface of the wind turbine rotor blade, for example, by adhesive. However, the heating element can also be placed in a mold for manufacturing a shell component of the wind turbine rotor blade and can be integrated into the shell component, for example by vacuum infusion of resin.
[0018] When arranged on a wind turbine rotor blade, the surface area of the wind turbine rotor blade covered by the heating element can be heated by a heating current supplied by a power supply line of the wind turbine rotor blade. The heating current flowing through the heating conductor heats the heating element and the corresponding surface area of the wind turbine rotor blade to remove ice accumulation (de-icing) and / or prevent ice from forming on the surface area (anti-icing).
[0019] The power supply circuit for a wind turbine rotor blade is typically integrated into the corresponding wind turbine rotor blade shell component during the shell component's production. The power supply circuit can also be attached to the wind turbine rotor blade shell component or the wind turbine rotor blade at a later time. The power supply circuit can include one or more connection points for connecting the first and second ends of the corresponding heating conductors. The connection points can include, for example, metal blocks, screws, or clips.
[0020] The heating element comprises a carrier layer and at least one heating conductor secured to the carrier layer. The carrier layer provides a basis for arranging the heating conductors in a desired configuration and allows for simplified handling of the heating element. When the heating elements are arranged in their defined operating position, each carrier layer has a first edge facing the blade tip and a second edge facing the blade root. The first and second edges may be arranged substantially in the chord plane and / or perpendicular to the longitudinal axis of the wind turbine rotor blade.
[0021] According to the present invention, each carrier layer has a strip-shaped edge portion with a first width along the first edge and a strip-shaped edge portion with a second width along the second edge. When the heating elements are arranged in a defined operating position, for each pair of adjacent heating elements, the first edge of one heating element in the pair is arranged adjacent to the second edge of the other heating element in the pair. These adjacent edges may abut each other. However, to allow for manufacturing tolerances, a small gap between adjacent edges and a small overlap between adjacent carrier layers are acceptable.
[0022] The first width and the second width are sized to position the heating conductors of the pair of heating elements at a predetermined distance sufficient to prevent flashover between the heating conductors. The predetermined distance may, for example, be in the range of approximately 20 mm to approximately 100 mm, but will depend, among other things, on the size of the heating elements and the location of the power supply lines. The predetermined distance can be calculated based on assumptions about the magnitude and slew rate of the lightning current and the resulting voltage induced in the heating system, as well as other electrical parameters of the wind turbine rotor blade. Alternatively, the required distance can be determined (or verified) experimentally.
[0023] The main advantage of the present invention is that arranging the heating elements in a defined operating position automatically ensures that a predetermined distance between adjacent heating conductors is adhered to, so as to prevent flashovers between the heating conductors when lightning strikes a wind turbine rotor blade and when large potential differences occur between adjacent heating conductors.
[0024] At the same time, arrangement of the heating elements is also particularly easy, since once a first heating element is in place, the position of an adjacent heating element can be found simply by placing the first edge of an adjacent carrier layer adjacent to the second edge of the carrier layer of the first heating element (or vice versa).
[0025] In one aspect, the strip edge portion is free of any heating conductors or other conductive elements. For example, the strip edge portion can be made of a non-conductive fiber material, such as glass fiber. This ensures that the strip edge portion provides good electrical insulation between adjacent heating conductors.
[0026] In one aspect, each heating element has a length measured between a first edge and a second edge thereof, wherein for each heating element, the first width plus the second width is in the range of 2% to 4% of the length of the heating element. In this way, the distance between adjacent heating conductors is generally large enough to prevent flashover, but not more than necessary to obtain smooth heating of the entire surface area covered by the heating element.
[0027] In one aspect, the carrier layer comprises a fiber mesh. For example, not only glass fibers but also any other fibers that provide the required stability can be used for this fiber mesh. Preferably, the fibers are electrically insulating fibers so that the heating current flows exclusively through the heating conductor in a defined manner. The fiber mesh provides the required stability and shear stiffness, which helps to minimize the weight of the heating element. The fiber mesh can also be attached to the wind turbine rotor blade using established techniques, such as lamination and / or vacuum resin infusion. In particular, the mesh size of the fiber mesh ranges from 1 mm to 10 mm, in particular from 2 mm to 6 mm. This represents a good compromise between stiffness and weight.
[0028] In one aspect, the first and second widths comprise a defined number of grid cells. This helps provide stability to the carrier layer in the region of the strip-shaped edge portions and facilitates handling of the heating element, thereby achieving a well-defined distance between adjacent heating conductors in practice.
[0029] In one aspect, the heating conductor is secured to the carrier layer by sewing with sewing yarns. The yarn tension and / or the spacing between adjacent stitches can be selected to reliably secure the heating conductor to the carrier layer. The sewing can be continuous or discontinuous, for example, in a zigzag pattern. Overall, using proven technology, a good and precise securement of the heating conductor to the carrier layer is achieved.
[0030] In one aspect, the heating conductor comprises a metal heating wire.The cross section of the metal heating wire and the resistance of the metal can be selected, for example, to provide a desired heating power at a given supply voltage.
[0031] In one aspect, the heating conductor comprises a bundle of carbon fibers. The bundle of carbon fibers can be a fiber roving. The cross-section can be selected to provide the desired electrical properties.
[0032] In one aspect, the heating conductor is fixed to the carrier layer in a meandering pattern over its main section. This way, with the exception of the strip-shaped edge sections, substantially the entire area of the carrier layer is covered by the heating conductor segments, resulting in a substantially uniform heat distribution. However, it is also possible to use more than one heating conductor on a single heating element. In this case, the heating conductors can be connected in parallel to the power supply lines of the wind turbine rotor blade, possibly using a common first and second end section. Each heating conductor can be fixed to the carrier layer to provide the required heating power for the portion of the area covered by the carrier layer.
[0033] The above-mentioned object is also solved by the following method. One aspect is given in the dependent claims. The method is for installing a heating system for a wind turbine rotor blade, comprising the following steps:
[0034] A wind turbine rotor blade is provided, the wind turbine rotor blade comprising a blade root, a blade tip, a suction side, a pressure side, a first power supply line arranged on the suction side, a second power supply line arranged on the pressure side, and an outer surface.
[0035] A plurality of heating elements are provided, wherein each of the heating elements comprises a carrier layer and a heating conductor fixed to the carrier layer, wherein each carrier layer has a first edge and a second edge, wherein the first edge has a strip-shaped edge portion with a first width and the second edge has a strip-shaped edge portion with a second width, wherein each heating conductor comprises a first end adapted to be connected to a first power supply line and a second end adapted to be connected to a second power supply line,
[0036] arranging a first heating element on said outer surface such that a first edge of the first heating element is towards the blade tip and a second edge of the heating element is towards the blade root,
[0037] arranging a second heating element on the outer surface such that a first edge of the second heating element is positioned adjacent to a second edge of the first heating element,
[0038] wherein the first width and the second width are sized to arrange the heating conductors of the first heating element and the second heating element at a predetermined distance, the predetermined distance being sufficient to prevent flashover between the heating conductors,
[0039] Therein, the heating conductor comprises a first end adapted to be connected to a first power supply line and a second end adapted to be connected to a second power supply line.
[0040] For details on the features and advantages of this method, please refer to the corresponding description of the heating system. It should be noted that the steps of this method do not necessarily have to be performed in the given order. In particular, the second heating element may be placed on the outer surface first, followed by the first heating element.
[0041] In one aspect, additional heating elements are arranged on the outer surface until all heating elements are arranged on the outer surface such that for each pair of adjacent heating elements, a first edge of one heating element of the pair is arranged adjacent to a second edge of another heating element of the pair. BRIEF DESCRIPTION OF THE DRAWINGS
[0042] Below, the utility model will be described in more detail with reference to the accompanying drawings:
[0043] Figure 1 shows a perspective view of a wind turbine rotor blade,
[0044] Figure 2 Shown Figure 1 Cross section of a wind turbine rotor blade,
[0045] Figure 3 Shown Figure 2 Schematic diagram of a portion of a wind turbine rotor blade,
[0046] Figure 4 Shown Figure 3 Magnified view of the cross section. DETAILED DESCRIPTION
[0047] Figure 1 A wind turbine rotor blade 10 is shown having a blade root 12, a blade tip 14, a suction side 16, and a pressure side 18. The suction side 16 and the pressure side 18 each extend between a leading edge 20 and a trailing edge 22.
[0048] The first power supply line 24 is arranged on the suction side 16. The second power supply line 26 (see Figure 2 ) is arranged on the pressure side 18. Both power supply lines 24 and 26 extend in the longitudinal direction of the wind turbine rotor blade 10, from the blade root 12 to the blade tip 14.
[0049] The wind turbine rotor blade 10 is provided with a heating system 28 comprising a plurality of heating elements 30. The heating elements 30 are arranged in rows on the outer surface of the wind turbine blade 10 in a longitudinal direction.
[0050] Figure 2 A cross section through a wind turbine rotor blade 10 is shown at a longitudinal location that includes one of the heating elements 30. The wind turbine rotor blade 10 has a chord 32 that extends between a leading edge 20 and a trailing edge 22. The heating element 30 extends over the leading edge 20 and covers a forward portion of the suction side 16 and a forward portion of the pressure side 18.
[0051] The first power supply line 24 is integrated into the wind turbine rotor blade half shell forming the suction side 16 and the second power supply line 26 is integrated into the wind turbine rotor blade half shell forming the pressure side 18. Each heating element 30 is connected to the first power supply line 24 and the second power supply line 26 via a connecting portion 34 of a heating conductor 36 (see Figure 3 ), so as to provide a heating current to the heating element 30.
[0052] Figure 3 A schematic cross-section of a wind turbine rotor blade 10 is shown at the leading edge 20, while the two half-shells forming the outer surface are shown unfolded to make it easier to understand the arrangement of the heating elements 30. The heating elements 30 are arranged in rows along the outer surface in the longitudinal direction. The illustrated arrangement of the heating elements 30 corresponds to a defined operating position of the heating elements 30.
[0053] Each heating element 30 has a carrier layer 38 and a heating conductor 36 fixed to the carrier layer. The heating elements 30, in particular the carrier layers 38, have different geometric shapes, each being approximately rectangular. The lengths 40 of the carrier layers 38 are all the same and extend in the longitudinal direction of the wind turbine blade 10, which is substantially along the longitudinal direction. Figure 3 The width 42 of the carrier layer 38 varies, with the heating element 30 closest to the blade tip 14 having the smallest width 42 and the heating element 30 closest to the blade root 12 having the largest width 42 .
[0054] The heating conductors 36 each have a first and a second connection portion 34 that extend in the longitudinal direction of the carrier layer 38 beyond the edges of the carrier layer arranged in the width direction. These connection portions 34 are connected to the first and second power supply lines 24 and 26, respectively. The main portion 58 of the heating conductor 36 is fixed to the carrier layer 38 in a meandering manner, so that the heating power is distributed substantially over the entire area of the carrier layer 38.
[0055] Each carrier layer 38 has a first edge 44 facing the blade tip 14 and a second edge 46 facing the blade root 12. The first edge 44 and the second edge 46 are arranged along the width direction (i.e., the chord plane) of the corresponding carrier layer 38. For each pair of adjacent heating elements 30, the first edge 44 of one heating element 30 in the pair is arranged adjacent to the second edge 46 of the other heating element 30 in the pair.
[0056] The carrier layers 38 each have a strip-shaped edge portion 48 along the first edge 44, said strip-shaped edge portion having a first width 50, and a strip-shaped edge portion 52 along the second edge 46, said strip-shaped edge portion having a second width 54. Figure 4 The first width 50 and the second width 54 are sized to arrange the heating conductors 36 of a pair of heating elements 30 at a predetermined distance 56 sufficient to prevent flashover between the heating conductors 36.
[0057] Figure 4 The enlarged view of FIG shows more details of the structure of the heating element 30, namely a fiber mesh 60 with a mesh size 62. The heating conductor 36 is fixed to the carrier layer 38 by means of stitches 64. Figure 3 and Figure 4 In FIG. 3 , the strip-shaped edge portions 48 and 52 are indicated by imaginary dashed lines, which separate the strip-shaped edge portions 48 and 52 from the remaining portion of the carrier layer 38 covered by the heating conductor 36 .
[0058] Reference Signs
[0059] 10 wind turbine rotor blades
[0060] 12 blade root
[0061] 14 blade end
[0062] 16 Suction side
[0063] 18 pressure side
[0064] 20 Front Edge
[0065] 22 trailing edge
[0066] 24 First power supply line
[0067] 26 Second power supply line
[0068] 28 Heating system
[0069] 30 heating elements
[0070] 32 chord
[0071] 34 Connection part
[0072] 36 heating conductors
[0073] 38 carrier layer
[0074] 40 (carrier layer) length
[0075] 42 (carrier layer) width
[0076] 44 First Edge
[0077] 46 Second Edge
[0078] 48 strip edge portion
[0079] 50 first width
[0080] 52 strip edge portion
[0081] 54 second width
[0082] 56 Predetermined distance
[0083] 58 Main Parts
[0084] 60 fiber mesh
[0085] 62 grid size
[0086] 64 stitches
[0087] 66 imaginary dotted line.
Claims
1. A heating system (28) for a wind turbine rotor blade (10), the wind turbine rotor blade (10) having a blade root (12), a blade tip (14), a suction side (16), a pressure side (18), a first power supply line (24) arranged on the suction side (16), a second power supply line (26) arranged on the pressure side (18), and an outer surface, wherein the heating system (28) comprises: a plurality of heating elements (30) adapted to be mounted in a row along the longitudinal direction of the wind turbine rotor blade (10) at defined operating positions on the outer surface, Each heating element (30) comprises a carrier layer (38) and a heating conductor (36) fixed to the carrier layer (38), wherein the heating conductor (36) has a first end adapted to be connected to the first power supply line (24) and a second end adapted to be connected to the second power supply line (26), wherein, when the heating element (30) is arranged in the defined operating position, each carrier layer (38) has a first edge (44) facing the blade tip (14) and a second edge (46) facing the blade root (12), characterized in that: The carrier layer (38) has a strip-shaped edge portion (48) with a first width (50) along the first edge (44) and a strip-shaped edge portion (52) with a second width (54) along the second edge (46), When the heating elements (30) are arranged in the defined operating position, for each pair of adjacent heating elements (30), a first edge (44) of one heating element (30) of the pair is arranged adjacent to a second edge (46) of the other heating element (30) of the pair, The first width (50) and the second width (54) are sized to arrange the heating conductors (36) of the pair of heating elements (30) at a predetermined distance (56) sufficient to prevent flashover between the heating conductors (36).
2. The heating system (28) according to claim 1, characterized in that The strip-shaped edge portions (48, 52) do not include any heating conductors (36) or any other electrically conductive elements.
3. The heating system (28) according to claim 1 or 2, characterized in that Each heating element (30) has a length (40) measured between its first edge (44) and its second edge (46), wherein for each heating element (30), the first width (50) plus the second width (54) is in the range of 2% to 4% of the length (40) of the heating element (30).
4. The heating system (28) according to claim 1 or 2, characterized in that The carrier layer (38) includes a fiber web (60).
5. The heating system (28) according to claim 4, characterized in that The first width (50) and the second width (54) include a defined number of grid cells (62).
6. The heating system (28) according to claim 1 or 2, characterized in that The heating conductor (36) is fixed to the carrier layer (38) by sewing with sewing yarns.
7. The heating system (28) according to claim 1 or 2, characterized in that The heating conductor (36) comprises a metal heating wire.
8. The heating system (28) according to claim 1 or 2, characterized in that The heating conductor (36) comprises a bundle of carbon fibers.
9. The heating system (28) according to claim 1 or 2, characterized in that The heating conductor (36) is fixed to the carrier layer (38) in a meandering manner in a main portion (58).