Method and device for non-destructive testing of wind turbine blades

• US 9,562,870 B2
• Filed: 09/27/2011
• Issued: 02/07/2017
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: ArianeGroup SAS
• Original Assignee: Astrium Sas (Airbus SE)
• Inventors: Bouteyre, Jacques, Jouan, Pascal
• Primary Examiner(s): West, Paul
• Application Number:
  US13/823,645
• Publication Number:
  US 20130235897A1
• Time in Patent Office: 1,960 Days
• US Class Current: 1/1
• CPC Class Codes: F03D 1/065 characterised by their construction elements F03D13/10 takes precedence
• CPC Class Codes: F05B 2260/83 Testing, e.g. methods, components or tools therefor
• CPC Class Codes: G01M 99/002 Thermal testing flaw detection G01N25/72
• CPC Class Codes: G01N 25/72 Investigating presence of flaws
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction

Abstract

The method CND of non-destructive testing of a wind turbine blade includes: stressing the structure of the blade through a modification of a physical characteristic of a fluid filling the hollow interior volume of the blade; observing zones to be tested of the exterior surface of the blade, with the contactless measurement of a physical parameter on points of the exterior surface of the blade; and comparing the map of the values of the physical parameter measured with a reference map. A corresponding system CND for checking the structural integrity of a wind turbine blade includes an aerothermic device for modifying the physical conditions, temperature or pressure, of a fluid filling the hollow interior volume of the blade, a device for contactless measurement of a physical parameter, temperature or dimensions, of the exterior surface of the blade, and a device for processing the measurements.

Claims

1. A NDT method (200) for non destructive testing of a wind turbine blade (10) attached to a wind turbine (100), a structure of said blade including a skin (13) determining a blade external surface (19) and a hollow volume (18) at the interior of the blade, said NDT method including:

a first step (201) for loading the blade structure, fixed to a turning shaft attached to a technical nacelle (30) located in an upper part of a carrying post (20), by a modification of at least one physical characteristic of a fluid filling out the blade hollow volume (18), using an aerothermic device (40) installed in the wind turbine;

a second step (202) for observing regions of the external surface (19) to be checked, said observation comprising the carrying out of contactless measurement with a measurement sensor, fixed remotely from the wind turbine, of at least one physical parameter, sensitive to the loading of the first step (201), on points of the external surface (19) in order to establish a measured map of the physical parameter values measured for said regions to be checked; and

a third step (203) for detecting structural anomalies in the blade by comparing values measured during the second step with expected values for a blade without any notable defect.

2. The NDT method according to claim 1, wherein the at least one modified physical characteristic corresponds to the fluid temperature into the hollow volume (18), said temperature of said fluid being brought to a value different from the temperature at the blade outside during the first step (201), and wherein the physical parameter measured during the second step (202) corresponds to a temperature of the blade external surface (19).

3. The NDT method according to claim 2, wherein the temperature of the blade external surface (19) is measured in a contactless manner by infra-red thermography.

4. The NDT method according to claim 1, wherein the at least one modified physical characteristic corresponds to a fluid pressure into the hollow volume (18), said pressure of said fluid being brought to a value different from the pressure at the blade outside during the first step (201), and wherein the physical parameter measured during the second step (202) corresponds to a geometrical dimension of the external surface (19) characterizing the geometrical form of said external surface.

5. The NDT method according to claim 4, wherein the geometrical dimension of the external surface (19) is measured by one of the laser telemetry, numerical photogrammetry, laser interferometry or shearography methods.

6. The NDT method according to claim 1, wherein the detection of anomalies carried out in the third step (203) includes a step for comparing the measured value at each point with measured values at points near to the considered point in order to establish a map of value contrasts of the measured parameter and includes a step for correlating said contrasts map with internal structures of the blade (10).

7. The NDT method according to claim 1, wherein the detection of anomalies carried out in the third step (203) includes a step for comparing the measured map with a reference map, said reference map being a reference map of the measured parameter values established by measurements according to the first and second steps (201, 202) of the method, on one or more blades considered as without defect, or a reference map established by a digital simulation of the method on a digital blade model, or it is an hybrid map obtained by hybridization of all or a part of reference maps established by measurement or digital simulation.

8. The NDT method according to claim 1, comprising a fourth step (204) for characterizing defects by a comparison of the anomalies identified at the third step (203), in real time during the measurement or in differed time, of each anomaly observed with known anomalies whose characteristics are stored in a bank of anomaly data.

9. A set including a wind turbine (100) and a NDT system for non destructive testing intended to check the structural integrity of a wind turbine blade (10), fixed to a turning shaft attached to a technical nacelle (30) located in an upper part of a carrying post (20) of the wind turbine (100) according to the process of claim 1, said blade comprising a skin (13) determining a blade external surface (19) and a blade hollow volume (18), comprising:

an aerothermic device (40) intended to modify physical conditions of a fluid filling out the blade internal hollow volume (18) and implemented either in the technical nacelle (30) or the wind turbine blade (10);

a contactless measurement device fixed remotely from the blade to be checked during the measurements and implementing at least a contactless sensor (51) of at least a physical parameter of the blade external surface (19);

a measurement processing device configured to establish a measured value map of the at least one parameter on the blade external surface (19) and to identify anomalies of said measured values map,

wherein the aerothermic device (40) is a heating or cooling device intended to modify the fluid temperature within the blade hollow volume (18) at a value different from the temperature at the blade outside,

wherein the measurement device provided with at least a contactless sensor (51) implements a thermal camera measuring the temperature of the blade external surface (19), and

wherein the contactless measurement device (50) is fixed on the ground, or on a terrestrial vehicle, or on a surface vessel, remotely from the wind turbine during the measurements.

10. A set including a wind turbine (100) and a NDT system for non destructive testing intended to check the structural integrity of a wind turbine blade (10), fixed to a turning shaft attached to a technical nacelle (30) located in an upper part of a carrying post (20) of the wind turbine (100) according to the process of claim 1, said blade comprising a skin (13) determining a blade external surface (19) and a blade hollow volume (18), characterized in that it comprises:

an aerothermic device (40) intended to modify physical conditions of a fluid filling out the blade internal hollow volume (18) and implemented either in the technical nacelle (30) or the wind turbine blade (10);

a measurement device implementing at least a contactless sensor (51) of at least a physical parameter of the blade external surface (19); and

a measurement processing device configured to establish a measured value map of the at least one parameter on the blade external surface (19) and to identify anomalies of said measured values map,

wherein the aerothermic device (40) is a heating or cooling device intended to modify the fluid temperature within the blade hollow volume (18) at a value different from the temperature at the blade outside,

wherein the measurement device provided with contactless sensors (51) implements a thermal camera measuring the temperature of the blade external surface (19), and

wherein the contactless measurement device (50) is fixed to an airborne platform (50) movable along the blade (10), near said blade.

11. The set including the wind turbine (100) and the NDT system according to claim 10, wherein the airborne platform (50) is maintained in levitation by a drone or micro-drone with a rotary aerofoil (53a) and controlled in position relatively to the blade (10) to be checked.

12. The set including the wind turbine (100) and the NDT system according to claim 10 wherein the airborne platform (50) is maintained in levitation by a captive balloon (53b) lighter than the air and controlled in position relatively to the blade (10) to be checked.

13. A set including a wind turbine (100) and a NDT system for non destructive testing intended to check the structural integrity of a wind turbine blade (10), fixed to a turning shaft attached to a technical nacelle (30) located in an upper part of a carrying post (20) of the wind turbine (100) according to the process of claim 1, said blade comprising a skin (13) determining a blade external surface (19) and a blade hollow volume (18), comprising:

an aerothermic device (40) intended to modify physical conditions of a fluid filling out the blade internal hollow volume (18) and implemented either in the technical nacelle (30) or the wind turbine blade (10);

a contactless measurement device fixed remotely from the blade to be checked during the measurements and implementing at least a contactless sensor (51) of at least a physical parameter of the blade external surface (19);

a measurement processing device configured to establish a measured value map of the at least one parameter on the blade external surface (19) and to identify anomalies of said measured values map,

wherein the aerothermic device (40) is a heating or cooling device intended to modify the fluid temperature within the blade hollow volume (18) at a value different from the temperature at the blade outside,

wherein the measurement device provided with contactless sensors (51) implements a thermal camera measuring the temperature of the blade external surface (19), and

wherein the contactless measurement device (50) is fixed on a robot movable along the blade (10) and bearing on said blade.

14. A set including a wind turbine (100) and a NDT system for non destructive testing intended to check the structural integrity of a wind turbine blade (10), fixed to a turning shaft attached to a technical nacelle 25 (30) located in an upper part of a carrying post (20) of the wind turbine (100) according to the process of claim 1, said blade comprising a skin (13) determining a blade external surface (19) and a blade hollow volume (18), comprising:

an aerothermic device (40) intended to modify physical conditions of a fluid filling out the blade internal hollow volume (18) and implemented either in the technical nacelle (30) or the wind turbine blade (10);

a contactless measurement device fixed remotely from the blade to be checked during the measurements and implementing at least a contactless sensor (51) of at least a physical parameter of the blade external surface (19);

a measurement processing device configured to establish a measured value map of the at least one parameter on the blade external surface (19) and to identify anomalies of said measured values map;

wherein the aerothermic device (40) is a heating or cooling device intended to modify the fluid temperature within the blade hollow volume (18) at a value different from the temperature at the blade outside,

wherein the measurement device provided with contactless sensors (51) implements a thermal camera measuring the temperature of the blade external surface (19), and wherein the contactless measurement device is movable along the blade (10) and the contactless sensor (51) is free of any physical contact with the blade (10).