Method for producing a wind turbine rotor blade, and wind turbine rotor blade

Abstract

A method of producing a wind turbine rotor blade For that purpose metal particles, metal powder or metal chips are mixed into a matrix used to produce the rotor blade. Inductive heating of the matrix with the metal particles, metal powder or metal chips is then effected to harden the matrix in at least one portion of the wind turbine rotor blade.

Claims

1. A method comprising: producing a wind turbine rotor blade comprising at least one of a glass fiber-reinforced plastic or carbon fiber-reinforced plastic bounded into a matrix, the producing comprising: mixing metal particles, metal powder, or metal chips into the matrix, and hardening the matrix in at least one portion of the wind turbine rotor blade by inductively heating the matrix with the metal particles, metal powder or metal chips, wherein a proportion of the metal powder, the metal particles, or the metal chips is between 5 and 20 percent by weight of the matrix.

2. The method according to claim 1 wherein the matrix with the metal particles, metal powder, or metal chips is provided at an end of a rotor blade, wherein the end of the rotor blade includes a rotor blade root, and wherein in a region of the rotor blade root, the matrix is exposed to an induction field generated by an induction coil so that the metal particles, metal powder or metal chips are inductively heated and transfer the heat to the matrix.

3. The method according to claim 1 wherein the wind turbine rotor blade has a first portion and a second portion, the second portion being arranged around the first portion, and wherein the matrix with the metal powder, the metal particles, or the metal chips is provided between the first and second portions.

4. The method according to claim 1 wherein the matrix has resin or epoxy resin.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Advantages and embodiments by way of example of the invention are described in greater detail hereinafter with reference to the drawing.

(2) FIG. 1 shows a diagrammatic view of a wind turbine according to the invention,

(3) FIG. 2 shows a diagrammatic view of a wind turbine rotor blade,

(4) FIG. 3 shows a diagrammatic view of a rotor blade root of a wind turbine rotor blade during production of the rotor blade, and

(5) FIG. 4 shows a cross-section through a rotor blade root of a rotor blade according to the invention.

DETAILED DESCRIPTION

(6) FIG. 1 shows a diagrammatic view of a wind turbine according to the invention. The wind turbine 100 has a tower 102 and a pod 104 on the tower 102. Provided on the pod 104 is an aerodynamic rotor 106 having three rotor blades 200 and a spinner 110. In operation of the wind turbine the aerodynamic rotor 106 is caused to rotate by the wind and thus also rotates a rotor or rotor member of a generator directly or indirectly coupled to the aerodynamic rotor 106. The electric generator is arranged in the pod 104 and generates electrical energy. The pitch angles of the rotor blades 200 can be altered by pitch motors at the rotor blade roots of the respective rotor blades 200.

(7) FIG. 2 shows a diagrammatic view of a wind turbine rotor blade. The rotor blade 200 has a rotor blade root 210 and a rotor blade tip 220 and extends along a longitudinal direction L. The rotor blade is made from glass fiber-reinforced plastic GRP and/or carbon fiber-reinforced plastic CRP with a matrix (or adhesive) 600 (for example epoxy resin). Provided in the region of the rotor blade root 210 are fixing means 300 which project with their first end into the rotor blade root region and which can be fixed with their second end to a rotor hub of a wind turbine.

(8) FIG. 3 shows a diagrammatic view of a rotor blade root of a wind turbine rotor blade during production of the rotor blade. Metal powder or metal chips or metal particles 400 can be provided in particular in the region of the rotor blade root 210 in the material or the matrix 600 of the rotor blade root 210. In addition provided in the region of the rotor blade root is a plurality of fixing units 300 which with their first end 310 project into the rotor blade root region 210 and with their second end 320 project out of the rotor blade root 210. The rotor blade root 210 is placed in the region of an induction coil 500 and the induction coil 500 is supplied with current/voltage by means of a power supply 510 to build up an induction field. The result of that induction field is that the metal particles, metal powder or metal chips 400 in the matrix 600 of the rotor blade root 210 are inductively heated. The metal particles 400 deliver the heat to the surrounding matrix 600 so that the matrix 600 is heated in the region of the rotor blade root 210 so that the matrix or adhesive used can be hardened therethrough and can be temperature-conditioned.

(9) According to an embodiment of the invention the metal particles, the metal powder or the metal chips 400 are provided in the rotor blade 200. Optionally the proportion of metal particles in the matrix 600 can be between 5 and 20 percent by weight.

(10) The metal particles 400 can be heated in the induction field generated by the induction coil 500. That makes it possible to achieve active heating in particular of the rotor blade root 210.

(11) The presence of the metal particles 400 in the matrix 600 of the rotor blade 200 can provide that the material becomes conductive in that region. If that is the case sufficient lightning protection has to be ensured as otherwise the rotor blade can be damaged in the event of a lightning strike.

(12) According to an aspect of the present invention the metal powder 400 is provided only in the region of the rotor blade root 210 which in the mounted condition of the rotor blade is typically within the pod. The pod of the wind turbine can here act as a Faraday cage so that the use of metal particles in the matrix 600 of the rotor blade root 210 does not have a detrimental effect on the capability of providing lightning protection for the wind turbine.

(13) Particularly in the case of very thick parts the use of metal particles in the matrix of the rotor blade is advantageous as it is possible to permit faster and more uniform heating.

(14) FIG. 4 shows a cross-section through a rotor blade root of a rotor blade according to the invention. The rotor blade root 210 can have a central portion 212 and a further portion 211 around the portion 212. The portion 211 can be in the form of a GRP (glass fiber-reinforced plastic) thickening. Optionally a portion which is to be bonded in place can be provided between the two portions 211, 212. The matrix or the adhesive 600 is provided with metal particles, metal powder 400 or the like in those regions. In order to bond the portions 211, 212 together the rotor blade root 210 is placed as shown in FIG. 3 in an induction field so that the metal particles 400 are heated and the adhesive bond can harden.

(15) FIG. 4 shows a region 200a outside the rotor blade and a region 200b within the rotor blade. The rotor blade root is preferably of a rotational symmetrical configuration.

(16) The rotor blade of the wind turbine has glass fiber-reinforced plastic GRP and/or carbon fiber-reinforced plastic CRP which are bound into a matrix (resin, epoxy resin). In production of the rotor blade the resin has to be hardened. That is effected by adding metal particles, metal powder or metal chips in the matrix of the rotor blade and by inductive heating of the matrix with the metal particles, metal powder or metal chips. That is advantageous because that provides for uniform heating (from the interior outwardly) of the matrix to harden the matrix.