Method of repairing or reinforcing wind turbine blade, or attaching accessory part to wind turbine blade

Patent metadata

Field	Value
Publication number	US-10815974-B2
Application number	US-201816227084-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Mar 29, 2018
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method of repairing or reinforcing, or attaching an accessory part to a wind turbine blade includes: determining a criterion to be satisfied by a repair member including a reinforcing fiber and a UV curable resin, the criterion being an adhesion strength of the repair member relative to a base member of the wind turbine blade; determining a work condition including: dimensions of the repair member, the number of the layers of the reinforcing fiber in the repair member, and/or a fiber extension direction of the reinforcing fiber, based on a damage condition of a repair target portion of the wind turbine blade; placing the reinforcing fiber and UV curable resin on the repair target portion based on the determined work condition; and obtaining the repair member by curing the UV curable resin so that the adhesion strength of the repair member relative to the base member satisfies the criterion.

First claim

The invention claimed is:

1. A method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade, the method comprising the steps of:
determining a criterion to be satisfied by a repair member including at least one layer of reinforcing fiber and a UV curable resin, the criterion being an adhesion strength of the repair member relative to a base member of a wind turbine blade;
determining a work condition including at least one of: dimensions of the repair member in a plan view, the number of the layers of the reinforcing fiber in the repair member, and a fiber extension direction of the reinforcing fiber, on a basis of a damage condition of a repair target portion of the wind turbine blade;
placing the reinforcing fiber and the UV curable resin on the repair target portion in accordance with the determined work condition; and
obtaining the repair member by curing the UV curable resin, with the reinforcing fiber and the UV curable resin being placed on the repair target portion in a manner in which the adhesion strength of the repair member relative to the base member satisfies the criterion,
wherein the determination of the work condition includes measuring dimensions of the repair target portion after removing a coating film on a surface of the base member of the wind turbine blade from the repair target portion,
wherein the placing includes:
on the basis of the dimensions, cutting a prepreg material including a resin composition containing at least one type of glass fiber and the UV curable resin and a transparent film attached on each surface of the resin composition while the prepreg material is contained in a bag having a light shielding property, the prepreg material being cut together with the bag into a size which satisfies the criterion of the adhesion strength; and
removing the bag that has been cut, and then adhering the prepreg material to the repair target portion, and

wherein the curing includes irradiating the prepreg material with UV light through the transparent film, with the transparent film being attached to an opposite surface of the prepreg material to a surface facing an outer skin of the wind turbine blade.

2. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , further comprising a step of checking whether a peel strength of the prepreg material that has been cured is equal to or larger than 3 MPa.

3. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , wherein
the UV curable resin includes vinyl ester or polyester and a UV curable agent impregnated in the vinyl ester or polyester.

4. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , wherein
the glass fiber includes at least one of unidirectional fiber where the fiber extension direction is uniform and a double bias mat including at least two fiber layers with different extension directions.

5. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , further comprising a step of performing a surface treatment on the base member by using a primer that has unsaturated polyester and styrene as main components and is bondable to the UV curable resin, before implementing the placing.

6. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , wherein the curing includes using a UV convergent irradiation device including a light source, and a concentrator or a diffuser arranged on an optical path of the light source.

7. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 6 , wherein the curing includes using the UV convergent irradiation device that includes any one of a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a xenon lamp, a black light blue lamp, a chemical lamp, a fluorescent tube UV lamp, and an excimer lamp, as the light source.

8. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 6 , wherein the curing includes using the UV convergent irradiation device that includes a lens configured to collect or diffuse the UV light emitted from an LED serving as the light source.

9. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , wherein the curing includes irradiating the UV curable resin with the UV light having a wavelength of approximately 380 nm and a light intensity of 150 W/cm 2 or more.

10. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , further comprising a step of implementing treatment of performing sanding on a step at a boundary portion between a surface of the cured UV curable resin and the outer skin of the wind turbine blade, and applying a surface coating agent at least on the outer skin after the sanding or attaching a sheet material at least to the outer skin.

11. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 10 , wherein the implementing treatment includes performing flattening so that the step has a level difference of 200 μm or less.

12. The method of repairing or reinforcing a wind turbine blade, or attaching an accessory part to the wind turbine blade according to claim 1 , wherein the placing includes using a rolling member to make the UV curable resin come into close contact with the repair target portion.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Watanabe Naota
• Yamasaki Hirokazu
• Hayashi Yoshihiko
• Kato Eiji

Classifications

• F03D1/0675

  of the blades · CPC title

• B29C73/10

  using patches sealing on the surface of the article (B29C73/14 takes precedence) · CPC title

• B29C66/026

  Chemical pre-treatments (B29C66/028 takes precedence) · CPC title

• F05B2230/80

  Repairing, retrofitting or upgrading methods · CPC title

• F03D1/0658

  Arrangements for fixing wind-engaging parts to a hub · CPC title