US-20260126028-A1 - WIND TURBINE ROTOR BLADE WITH AN ELECTRICAL HEATING SYSTEM

US20260126028A1US 20260126028 A1US20260126028 A1US 20260126028A1US-20260126028-A1

Abstract

A wind turbine rotor blade including a blade root, a blade tip, a leading edge, a trailing edge, a suction side, a pressure side and a heatable surface area including at least one electrical heating element, wherein the heatable surface area covers a section of the leading edge and has a first edge facing the blade tip, a second edge facing the blade root, a third edge arranged on the suction side and a fourth edge arranged on the pressure side, characterized in that the wind turbine rotor blade includes a first layer of an electrically insulating material, wherein the first layer is smaller than the heatable surface area and is arranged on top of the at least one electrical heating element along the leading edge and such that it extends beyond the first edge.

Inventors

Jochen Kremer
Thomas Lipka

Assignees

NORDEX ENERGY SE & CO. KG

Dates

Publication Date: 20260507
Application Date: 20251106
Priority Date: 20241107

Claims (16)

1 . A wind turbine rotor blade comprising: a blade root, a blade tip, a leading edge, a trailing edge, a suction side, a pressure side, and a heatable surface area including at least one electrical heating element; wherein said heatable surface area covers a section of said leading edge and has a first edge facing said blade tip, a second edge facing said blade root, a third edge arranged on said suction side, and a fourth edge arranged on said pressure side; and, a first layer of an electrically insulating material, wherein said first layer is smaller than said heatable surface area and is arranged on top of said at least one electrical heating element along said leading edge and such that said first layer extends beyond said first edge of said heatable surface area.
2 . The wind turbine rotor blade of claim 1 , wherein said first layer has a second edge facing said blade root; and, at least a section of said second edge of said first layer is arranged on top of said heatable surface area in a distance from said second edge of said heatable surface area.
3 . The wind turbine rotor blade of claim 1 , wherein at least one of: said first layer has a third edge on said suction side, at least a section of said third edge of said first layer is arranged on top of said heatable surface area at a distance from said third edge of said heatable surface area; and, said first layer has a fourth edge on said pressure side, at least a section of said fourth edge of said first layer is arranged on top of said heatable surface area at a distance from said fourth edge of said heatable surface area.
4 . The wind turbine rotor blade of claim 1 further comprising: a second layer of an electrically insulating material; and, said second layer being smaller than said heatable surface area and being arranged on top of said at least one electrical heating element along said leading edge and such that said second layer extends beyond said first edge of said heatable surface area.
5 . The wind turbine rotor blade of claim 4 , wherein a first edge of said second layer in a longitudinal direction is arranged between said first edge of said heatable surface area and said first edge of said first layer.
6 . The wind turbine rotor blade of claim 4 , wherein said second layer has a second edge facing said blade root; and, at least a section of said second edge of said second layer is arranged within a surface covered by said first layer and at a distance from said second edge of said first layer.
7 . The wind turbine rotor blade of claim 4 , wherein at least one of: said second layer has a third edge on said suction side, at least a section of said third edge of said second layer is arranged within a surface covered by said first layer and at a predetermined distance from said third edge of said first layer; and, said second layer has a fourth edge on said pressure side, wherein at least a section of said fourth edge of said second layer is arranged within a surface covered by said first layer and at a distance from said fourth edge of said first layer.
8 . The wind turbine rotor blade of claim 4 further comprising: a third layer of an electrically insulating material, wherein said third layer is smaller than said heatable surface area and is arranged on top of said at least one electrical heating element along said leading edge and such that said third layer extends beyond said first edge of said heatable surface area; said third layer being arranged at least one of: a first edge of said third layer in a longitudinal direction is arranged between said first edge of said heatable surface area and a first edge of said second layer; said third layer has a second edge facing said blade root; and, at least a section of said second edge of said third layer is arranged within a surface covered by said second layer and at a distance from said second edge of said second layer; said third layer has a third edge on said suction side, at least a section of said third edge of said third layer is arranged within a surface covered by said second layer and at a predetermined distance from said third edge of said second layer; and, said third layer has a fourth edge on said pressure side, wherein at least a section of said fourth edge of said third layer is arranged within a surface covered by said second layer and at a distance from said fourth edge of said second layer.
9 . The wind turbine rotor blade of claim 1 , wherein said at least one electrical heating element includes a plurality of electrical heating elements arranged in a row along said leading edge; each of said plurality of electrical heating elements has a first edge facing said blade tip and a second edge facing said blade root; and, the wind turbine rotor blade further comprising at least one strip of an electrically insulating material arranged on top of the first edge of one of said plurality of electrical heating elements and on top of the second edge of an adjacent one of said plurality of electrical heating elements.
10 . The wind turbine rotor blade of claim 1 , wherein said at least one electrical heating element includes a plurality of electrical heating elements arranged in a row along said leading edge; each of said plurality of electrical heating elements has a first connecting section connected to a first electrical supply line on said suction side and a second connecting section connected to a second electrical supply line on said suction side; and, the wind turbine rotor blade further comprising at least one strip of an electrically insulating material arranged on top of at least one of said first connecting section and said second connecting section.
11 . The wind turbine rotor blade of claim 10 , wherein at least one of: said first electrical supply line is arranged between said trailing edge and said third edge of said heatable surface area, said at least one strip of electrically insulating material arranged on top of said first connecting section extends from said third edge of said heatable surface area to said first electrical supply line or beyond; and, said second electrical supply line is arranged between said trailing edge and said fourth edge of said heatable surface area, said at least one strip of electrically insulating material arranged on top of said second connecting section extends from said fourth edge of said heatable surface area to said second electrical supply line or beyond.
12 . The wind turbine rotor blade of claim 1 further comprising: a lightning receptor arranged at said blade tip; and, said first edge of said heatable surface area being arranged at a distance in a range of 1 meter to 4 meters from said blade tip.
13 . The wind turbine rotor blade of claim 1 further comprising at least one additional lightning receptor arranged at least one of: between said trailing edge and said third edge of said heatable surface area; and, between said trailing edge and said fourth edge of said heatable surface area.
14 . The wind turbine rotor blade of claim 1 , wherein said insulating material includes glass fibers.
15 . The wind turbine rotor blade of claim 1 , wherein said at least one electrical heating element includes a heating conductor fastened to a carrier layer of the wind turbine rotor blade.
16 . The wind turbine rotor blade of claim 15 , wherein said heating conductor includes a metal heating wire or a bundle of carbon fibers.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority of European patent application no. 24211369.4, filed November 7, 2024, the entire content of which is incorporated herein by reference. TECHNICAL FIELD The disclosure relates to a heating system for a wind turbine rotor blade with an electrical heating system. BACKGROUND EP 2667025 A1 discloses a wind turbine rotor blade with a heating mat having two segments running in parallel along a longitudinal direction of the wind turbine rotor blade. To avoid a short circuit between the two segments, a layer of an insulating material is placed between the adjacent segments, wherein the layer is arranged underneath one of the two segments and on top of the adjacent segment. EP 2843228 A1 discloses a wind turbine rotor blade with an electrical heating system including a plurality of electrical heating elements arranged on an outer surface of the wind turbine rotor blade. Each of the heating elements has a carrier layer and a heating conductor arranged on the carrier layer between two opposite edges of the heating element in a meandering pattern. The heating elements are arranged on an outer surface of the wind turbine rotor blade. Free ends of each heating conductor are connected to two electrical supply lines which are running along a length of the blade and also serve as lightning down conductors. In case of lightning, the heating elements shall provide potential equalization between the two lightning down conductors. An outer side of the heating elements is provided with an erosion protection layer. SUMMARY It is an object of the disclosure to provide a wind turbine rotor blade with an electrical heating system that offers improved lightning protection. This object is, for example, achieved by the wind turbine rotor blade according to various embodiments of the disclosure. A wind turbine rotor blade includes a blade root, a blade tip, , a leading edge, a trailing edge, a suction side, a pressure side and a heatable surface area including at least one electrical heating element, wherein the heatable surface area covers a section of the leading edge and has a first edge facing the blade tip, a second edge facing the blade root, a third edge arranged on the suction side and a fourth edge arranged on the pressure side, wherein the wind turbine rotor blade includes a first layer of an electrically insulating material, wherein the first layer is smaller than the heatable surface area and is arranged on top of the at least one electrical heating element along the leading edge and such that it extends beyond the first edge. The wind turbine rotor blade has an outer surface which corresponds to an aerodynamic surface of the wind turbine rotor blade. The wind turbine rotor blade may include a shell structure forming the outer surface, for example including two wind turbine rotor blade half shells, such as a pressure side half shell and a suction side half shell. The at least one heating element can be connected to first and second electrical supply lines so that a heating current can be guided through the at least one heating element. In this manner, the at least one heating element and the heatable surface area of the wind turbine rotor blade can be heated in order to remove accumulated ice (de-icing) and/or in order to prevent the formation of ice (anti-icing) on this surface area. The at least one heating element may have an essentially rectangular or trapezoidal shape which is folded about the leading edge of the wind turbine rotor blade. The shape of the at least one heating element defines the heatable surface area. Typically, a plurality of heating elements will be arranged on the outer surface of the wind turbine rotor blade, together defining the heatable surface area. The disclosure is based on the observation that lightning striking a wind turbine rotor blade with a suitable lightning protection system may not only damage any electrically conducting elements within the wind turbine rotor blade which are arranged near a lightning down conductor, caused by flashovers between the lightning down conductor and the electrically conducting element. In addition, the heating elements themselves may get struck by a direct lightning strike when under the influence of a high electric field strength free charge carriers (electrons or ions) are accelerated out of the heating element and contribute to the formation of a current channel. This risk may be reduced by an electrical isolation of the heating elements. However, any isolating material placed on top of the heating elements adds to the total weight of the wind turbine rotor blade and also potentially reduces the efficiency of the heating system. The isolating material may also decrease the aerodynamic performance of the wind turbine rotor blade due to unwanted alterations of the surface geometry and surface structure. Based on these considerations, the inventors found a way to achieve a significant r