JP2020084780A - Windmill blade and wind power generation system - Google Patents

Abstract

【Task】
Equipped with a strain detection system that allows easy replacement of optical fiber sensors.
[Solution]
In order to solve the above problems, a wind turbine blade according to the present invention is a wind turbine blade including at least one blade that constitutes a rotor that receives wind and has a groove provided on an outer surface of the blade. A strain detection system including at least one optical fiber sensor is installed along the groove.
[Selection diagram] Fig. 6(c)

Description

The present invention relates to a wind turbine blade and a wind turbine generator system, and more particularly to a wind turbine blade and a wind turbine generator system including an optical fiber sensor that detects strain of the blade.

In recent years, from the viewpoint of environmental protection such as the problem of global warming, the demand for wind power generation systems using renewable energy has been expanding. The blade of the wind turbine that constitutes the wind power generation system is subjected to wind that changes its speed and direction from moment to moment, and undergoes bending deformation and torsional deformation. Further, the blade vibrates according to the fluctuation of the wind and the rotation cycle of the rotor, and fatigue damage accumulates. In addition, it can be damaged by lightning strikes.

Further, in recent years, there is a tendency to increase the size of a wind power generation system in order to improve power generation efficiency, and a huge wind power generation system having a rotor with a rotation diameter of more than 100 m is being put to practical use.

Therefore, in a large-scale wind power generation system, since the wind-receiving area of the rotor is expanded, the blade is subjected to a larger deformation than in a small-medium-sized wind power generation system. Further, as the size of the wind power generation system increases, the altitude of the rotor from the ground also increases, which increases the risk of lightning strikes on systems such as blades.

Therefore, in order to maintain the soundness of the blade, it is necessary to constantly monitor the deformation behavior of the blade, detect the damage of the blade and grasp the progress of the damage, and perform repair if necessary.

Conventionally, in order to detect the amount of deformation such as bending or twisting of the blade, an electric strain sensor has been attached to the inner surface or the outer surface of the blade to measure the strain. However, the electrical strain sensor has a large risk of being damaged by a lightning strike, and in addition, electromagnetic noise generated by surrounding instruments is apt to be mixed in the measurement data.

Patent Document 1 can be cited as a prior art document for solving such a problem.

This patent document 1 describes a wind turbine generator in which an optical fiber sensor such as a fiber Bragg grating (FBG) sensor is installed on a blade and the strain of the blade is detected by the optical fiber sensor. The optical fiber sensor described in Patent Document 1 is less likely to be damaged by a lightning strike than an electric strain sensor, and electromagnetic noise from surrounding instruments is not mixed into measurement data.

JP 2004-36612 A

However, in the wind turbine generator described in Patent Document 1 described above, not only the method of replacing the optical fiber sensor when the optical fiber sensor fails but also the arrangement of the optical fiber sensor for facilitating the replacement is described. Absent.

For example, if the optical fiber sensor is arranged on the inner surface of the blade, when the optical fiber sensor fails, it is necessary to access the closed space inside the blade and perform replacement work. However, as a structural problem of the blade, the area in which a person can enter is limited to about 1/3 from the root to the entire length of the blade (when the width is 1/3 or more from the root to the entire length of the blade, the width of the blade is Since it becomes narrower, no one can intrude), and it becomes difficult to replace the optical fiber sensor arranged at the tip side of the blade.

Further, when the optical fiber sensor is embedded inside the blade material, it is necessary to remove the material around the optical fiber sensor before replacing the optical fiber sensor. In addition, since the material around the optical fiber sensor needs to be repaired after the replacement of the optical fiber sensor, a lot of cost is required.

On the other hand, when the optical fiber sensor is arranged on the outer surface of the blade, a crane can be used to allow a person to reach the optical fiber sensor from the outer side of the blade, which facilitates replacement of the optical fiber sensor.

However, when the optical fiber sensor is provided on the outer surface of the blade, the optical fiber sensor forms a convex surface on the surface of the blade, and the convex surface acts as wind resistance and deteriorates the aerodynamic performance of the blade. The power generation efficiency of the system may decrease.

Further, when the optical fiber sensor is provided on the outer surface of the blade, the optical fiber sensor is exposed to the atmosphere, so that the adhesive is deteriorated by collision of flying objects such as wind and rain, hail, and dust, and irradiation of ultraviolet rays, and the long-term It may be difficult to measure the strain.

Therefore, it is necessary to determine the arrangement position of the optical fiber sensor in consideration of the ease of replacement of the optical fiber sensor and the protection method of the optical fiber sensor.

The present invention has been made in view of the above points, and an object of the present invention is to provide a wind turbine blade and a wind power generation system including a strain detection system capable of easily replacing an optical fiber sensor.

The wind turbine blade of the present invention is, in order to achieve the above object, a wind turbine blade consisting of at least one blade that constitutes a rotor that receives wind and rotates, and a groove is provided on an outer surface of the blade, A strain detection system including at least one optical fiber sensor is installed along the groove.

Further, in order to achieve the above object, the wind power generation system of the present invention includes a tower, a nacelle installed on the upper part of the tower so as to be rotationally driven in a horizontal plane, and at least one nacelle connected to the nacelle. A wind power generation system comprising: a wind turbine blade and a rotor configured of a hub, wherein the wind turbine blade is the wind turbine blade having the above configuration.

According to the present invention, it is possible to obtain a wind turbine blade and a wind power generation system including a strain detection system capable of easily replacing an optical fiber sensor.

It is an appearance perspective view showing Example 1 of the wind power generation system of the present invention. It is a schematic diagram of one blade showing Example 1 of the wind turbine blade of the present invention. It is sectional drawing which followed the AA line of FIG. 2 (a). It is a schematic diagram which shows an example of a structure of the strain detection system employ|adopted as Example 1 of the windmill blade of this invention. It is a schematic diagram which shows the state which installed the blade of the strain detection system of the structure shown in FIG. It is sectional drawing which followed the BB line|wire of FIG.4(a). FIG. 5 is a detailed view of a C portion of FIG. It is a figure corresponding to Drawing 4 (c) showing Example 2 of the wind turbine blade of the present invention. It is a schematic diagram which shows Example 3 of the windmill blade of this invention, and shows the state which installed the strain detection system in the blade. It is sectional drawing which followed the EE line of FIG.6(a). FIG. 7 is a detailed view of an F portion of FIG. It is a figure equivalent to Drawing 6 (c) showing Example 4 of the wind turbine blade of the present invention. It is a figure which shows Example 5 of the windmill blade of this invention, and is equivalent to FIG.6(c). It is a schematic diagram which shows Example 6 of the windmill blade of this invention, and shows the state which installed the strain detection system in the blade. It is a figure which shows Example 7 of the windmill blade of this invention, and is equivalent to FIG.6(c). It is a figure equivalent to FIG.6(c) which shows Example 8 of the windmill blade of this invention. It is a schematic diagram which shows Example 9 of the windmill blade of this invention, and shows an example of a structure of a strain detection system. It is a schematic diagram which shows Example 10 of the windmill blade of this invention, and shows an example of a structure of a strain detection system. It is a figure which shows Example 11 of the windmill blade of this invention, and is equivalent to FIG.6(c).

Hereinafter, the wind turbine blade and the wind power generation system of the present invention will be described based on the illustrated embodiments. In each embodiment, the same reference numerals are used for the same components.

FIG. 1 shows an external configuration of the wind power generation system of the present invention.

As shown in FIG. 1, a wind turbine 1 includes a tower 2, a nacelle 3 installed above the tower 2 so as to be rotationally driven in a horizontal plane, and three blades 4a, 4b, 4c connected to the nacelle 3. And a rotor 6 composed of a hub 5. The rotor 6 is rotatably supported by the nacelle 3 via a main shaft (not shown). Note that the number of blades 4a, 4b, and 4c is merely an example, and it goes without saying that other numbers may be used.

2A shows a blade 4a, and FIG. 2B shows a sectional structure taken along line AA of FIG. 2A.

As shown in the figure, the blade 4a includes a main girder 15 and an outer skin (shell) 17 on the suction side 13, a main girder 16 and a shell 18 on the pressure side 14, a web 19a and a trailing edge 12 side on the leading edge 11 side. And a web 19b of. In most cases, the main girder 15 on the negative pressure side 13 and the main girder 16 on the positive pressure side 14 are formed by laminating fiber reinforced resin (FRP). Generally, glass fibers or carbon fibers are used as the FRP fibers used for the blades 4a, 4b, 4c, and epoxy resin or unsaturated polyester resin is used as the base resin.

On the other hand, the shell 17 on the negative pressure side 13 and the shell 18 on the positive pressure side 14, the web 19a on the front edge 11 side and the web 19b on the rear edge 12 side are made of a foamed resin material such as polyvinyl chloride or wood such as balsa and the like as an FRP skin. It is made of sandwich material sandwiched between.

In this embodiment, the composition of FRP is glass fiber and epoxy resin, the core material of the shell 17 of the negative pressure side 13 and the shell 18 of the positive pressure side 14 is balsa, the web 19a on the front edge 11 side and the web 19b on the rear edge 12 side. Polyvinyl chloride is assumed for the core material. However, the following examples are not limited to the material composition of the FRP and the core material. Further, the numbers of the webs 19a on the front edge 11 side and the webs 19b on the rear edge 12 side are exemplifications, and other numbers can be taken.

FIG. 3 shows the configuration of the strain detection system 21 used in this embodiment.

The strain detection system 21 shown in FIG. 3 is an interrogator 22 provided with a light source that radiates a wavelength in a wide band, a detector for the wavelength and intensity of reflected light, and an arithmetic unit that converts the amount of change in wavelength into strain, and three optical fibers. Sensors 23a, 23b, 23c, optical fiber cables 25a and 25b connecting the interrogator 22 and the optical fiber sensor 23a, optical fiber cables 25c and 25d connecting the optical fiber sensors 23a and 23b, and light connecting the optical fiber sensors 23b and 23c. It is composed of fiber cables 25e and 25f.

The optical fiber cables 25a and 25b are connected by a connector 24a, the optical fiber cables 25c and 25d are connected by a connector 24b, and the optical fiber cables 25e and 25f are connected by a connector 24c.

The optical fiber cables 25a and 25b are detachably connected to the connector 24a, the optical fiber cables 25c and 25d are detachable from the connector 24b, and the optical fiber cables 25e and 25f are detachable from the connector 24c. It is connected.

In this embodiment, an FBG sensor is assumed as the optical fiber sensors 23a, 23b, 23c, and this FBG sensor is arranged along at least one of the blades 4a, 4b, 4c along the longitudinal direction. There is.

The type of optical fiber sensor is not limited to the FBG sensor. In addition to the FBG sensor, for example, a distributed optical fiber sensor that detects scattered light in the optical fiber may be used. Further, in the present embodiment, the number of optical fiber sensors is illustratively three, but the number of optical fiber sensors is not limited.

Further, the optical fiber sensors 23a, 23b, 23c and the connectors 24a, 24b, 24c are serially connected in a substantially linear shape, but are connected in a curved shape in series depending on the arrangement of the optical fiber sensors 23a, 23b, 23c. Alternatively, at least one of the connectors 24a, 24b, 24c may be branched to connect the optical fiber sensors 23a, 23b, 23c in parallel.

Then, in the strain detection system 21 of the present embodiment, the light emitted from the interrogator 22 is transmitted to the optical fiber sensor 23a via the optical fiber cable 25a, the connector 24a and the optical fiber cable 25b, and transmitted through the optical fiber sensor 23a. The transmitted light is transmitted to the optical fiber sensor 23b via the optical fiber cable 25c, the connector 24b and the optical fiber cable 25d, and the light transmitted through the optical fiber sensor 23b is further transmitted to the optical fiber cable 25e, the connector 24c and the optical fiber cable. It is transmitted to the optical fiber sensor 23c via 25f.

The optical fiber sensors 23a, 23b, 23c emit light having a wavelength corresponding to the amount of change in strain in the sensor axis direction at an arbitrary position on the arranged blade 4a to the optical fiber cables 25a, 25b, 25c, 25d, 25e. And 25f to the interrogator 22. The interrogator 22 detects the wavelength and intensity of the transmitted reflected light and converts it into a strain amount in the sensor axis direction corresponding to the wavelength.

FIG. 4A shows a state in which the strain detection system 21 is installed on the blade 4a, FIG. 4B shows a cross section taken along the line BB in FIG. 4A, and FIG. Details of section C in b) are shown below.

In the embodiment shown in the figure, the optical fiber sensors 23a, 23b, 23c, the connectors 24a, 24b, 24c, the optical fiber cables 25b, 25c, 25d, 25e, 25f and the portion of the optical fiber cable 25a which overlaps with the blade 4a are respectively It is embedded along the groove 31 provided on the outer surface of the main girder 15 on the negative pressure side of the blade 4a.

The width w of the opening of the groove 31 shown in FIG. 4C is w≧D with respect to the diameter D of the cross section of the optical fiber sensor 23b, and the depth h of the groove 31 is the diameter of the cross section of the optical fiber sensor 23b. For D, h≧D. The groove 31 may be formed to have the original shape of the blade 4a, or may be formed by excavation or the like after the outer surface of the blade 4a is formed smoothly.

Although FIG. 4C illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

In this embodiment having such a configuration, no convex surface is formed on the outer surface of the blade 4a even when the optical fiber sensors 23a, 23b, and 23c are arranged on the outer surface of the blade 4a.

Therefore, the turbulence of the air flow along the blade 4a can be suppressed, and the deterioration of the aerodynamic performance of the blade 4a can be suppressed. Further, since the optical fiber sensors 23a, 23b, 23c are arranged on the outer surface of the blade 4a, they can be easily replaced when the optical fiber sensors 23a, 23b, 23c fail. For example, by using a crane, a person can easily reach the outer surface of the blade 4a, so that the defective sensor of the optical fiber sensors 23a, 23b, 23c can be extracted and replaced with a new one.

As an example, when the optical fiber sensor 23b fails, first, the optical fiber cable 25d is detached from the connector 24b and the optical fiber cable 25e is detached from the connector 24c. Then, the optical fiber sensor 23b and the optical fiber cables 25d and 25e are pulled out from the groove 31, and a new optical fiber sensor and the optical fiber cable are installed in the groove 31. Finally, the optical fiber sensor can be replaced by connecting the new optical fiber cable and the connectors 24b and 24c, respectively.

Further, the optical fiber sensors 23a, 23b, 23c may be fixed to the groove 31 by using an adhesive, a double-sided tape or the like. Thereby, the accuracy of measuring the strain of the blade 4a can be improved.

Further, the connectors 24a, 24b, 24c and the optical fiber cables 25a, 25b, 25c, 25d, 25e, and 25f do not have to be fixed to the groove 31 by using an adhesive or a double-sided tape. By not fixing the connectors 24a, 24b, 24c and the optical fiber cables 25a, 25b, 25c, 25d, 25e and 25f in the groove 31, it is possible to connect the new optical fiber cable and the connectors 24a, 24b, 24c more easily. ..

In the first embodiment, the optical fiber sensors 23a, 23b, 23c are arranged on the main girder 15 on the suction side of the blade 4a, but they are arranged on other positions of the blade 4a, for example, on the outer surface of the shell 17 on the suction side. Is also good.

Example 2 of this invention is shown in FIG. FIG. 5 shows a cross section of the optical fiber sensor 23b, the groove 31 and the main girder 15 on the negative pressure side, which is an embodiment in which the shape of the groove 31 is different, and shows an improvement plan of FIG. 4(c) described above.

That is, the width w of the opening of the groove 31 of the embodiment shown in FIG. 5 is w<D with respect to the diameter D of the cross section of the optical fiber sensor 23b, and the depth h of the groove 31 is the cross section of the optical fiber sensor 23b. By setting h≧D with respect to the diameter D, the optical fiber sensor 23b is partially covered by the edge portion 31a of the opening of the groove 31.

The optical fiber sensor 23b is installed in the groove 31 by pressing from the opening of the groove 31. Therefore, the main girder 15 on the negative pressure side in which the groove 31 is formed is preferably flexible, and for example, FRP (GFRP, CFRP) or the like can be considered.

5 illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

As a result, the same effects as those of the first embodiment can be obtained, and since the optical fiber sensors 23a, 23b, and 23c are partially covered by the edge portion 31a of the opening of the groove 31, the main girder 15 on the negative pressure side 15 can be obtained. Is more firmly fixed. Further, since the optical fiber sensors 23a, 23b, 23c are partially protected by the edge portion 31a of the opening of the groove 31, it is possible to suppress a measurement error due to wind, rain, dust, or the like.

Further, it is possible to suppress deterioration of the optical fiber sensors 23a, 23b, 23c due to wind and rain, ultraviolet rays, or the like, and deterioration of the adhesive when the adhesive is used to fix the optical fiber sensors 23a, 23b, 23c.

The minimum value of the width w of the opening of the groove 31 is set to a limit value at which the optical fiber sensors 23a, 23b, and 23c can be pressed and embedded in the groove 31 without damaging the outer surface of the main girder 15 on the negative pressure side. To take. That is, when the optical fiber sensors 23a, 23b, 23c are pushed into the groove 31, the width w of the opening of the groove 31 is set so as not to damage the outer surface of the main girder 15 on the negative pressure side.

In the second embodiment, the optical fiber sensors 23a, 23b, and 23c are arranged on the main girder 15 on the negative pressure side of the blade 4a, but they are arranged on other positions of the blade 4a, for example, on the outer surface of the shell 17 on the negative pressure side. Is also good.

In Examples 1 and 2, the optical fiber sensors 23a, 23b, 23c are arranged on the outer surface of the blade 4a without forming an associated convex surface, thereby facilitating the replacement of the optical fiber sensors 23a, 23b, 23c. At the same time, the deterioration of the aerodynamic performance of the blade 4a is suppressed.

However, in reality, minute irregularities may be formed on the corners of the groove 31 and on the surface side in contact with the atmosphere due to the embedding of the optical fiber sensors 23a, 23b, 23c, and the air flow may be slightly disturbed. Conceivable.

Therefore, more preferably, the third embodiment described below (FIG. 6A, FIG. 6B and FIG. 6C). The third embodiment shown in FIGS. 6(a), 6(b) and 6(c) facilitates replacement of the optical fiber sensors 23a, 23b, 23c, and also reduces the aerodynamic performance of the blade 4a. Is more suppressed.

FIG. 6A shows a state in which the strain detection system 32 is installed on the blade 4a, FIG. 6B shows a cross section taken along the line EE of FIG. 6A, and FIG. Details of the F part of b) are shown respectively.

The strain detection system 32 shown in the figure includes an interrogator 22, optical fiber sensors 23a and 23b, an optical fiber cable 25a connecting the interrogator 22 and the connector 24a, an optical fiber cable 25b connecting the connector 24a and the connector 24b, and a connector 24b. And an optical fiber cable 25c connecting the optical fiber sensor 23a, an optical fiber cable 25d connecting the optical fiber sensor 23a and the connector 24c, an optical fiber cable 25e connecting the connector 24c and the connector 24d, and an optical fiber connecting the connector 24d and the connector 24e. It is roughly configured by a cable 25f and an optical fiber cable 25g connecting the connector 24e and the optical fiber sensor 23b.

The optical fiber sensors 23a and 23b, the connectors 24a, 24b, 24c, 24d and 24e, the optical fiber cables 25b, 25c, 25d, 25e, 25f and 25g, and the portion of the optical fiber cable 25a overlapping the blade 4a are shown in FIG. As shown in (c), it is embedded along a groove 31 provided on the outer surface of the main girder 15 on the negative pressure side of the blade 4a.

In the present embodiment, the openings of the grooves 31 provided on the outer surface of the main girder 15 on the negative pressure side of the blade 4a are covered with the covers 26a, 26b, 26c and 26d. That is, the optical fiber sensors 23a and 23b, the connectors 24a, 24b, 24c, 24d and 24e and the optical fiber cables 25a, 25b, 25c, 25d, 25e, 25f and 25g are covered with covers 26a, 26b, 26c and 26d. (The opening of the groove 31 is covered) to protect them.

The depth h of the groove 31 in this embodiment is h≧D with respect to the diameter D of the cross section of the optical fiber sensors 23a and 23b, and the width w′ of the covers 26b and 26d covering the optical fiber sensors 23a and 23b is , W′≧D with respect to the diameter D of the cross section of the optical fiber sensors 23a and 23b. The outer surface shape of the covers 26 a, 26 b, 26 c and 26 d is smoothly connected to the outer surface shape of the main girder 15 on the negative pressure side around the groove 31.

When the groove 31 is provided by excavation or the like after forming the blade 4a, it is desirable that the outer surface shape of the covers 26a, 26b, 26c and 26d be formed to be equal to the original surface shape of the blade 4a.

Further, in the present embodiment, the material of the covers 26a, 26b, 26c and 26d is assumed to have the same composition as the FRP constituting the blade 4a.

In this embodiment, since the outer surface of the main girder 15 on the negative pressure side and the outer surfaces of the covers 26a, 26b, 26c and 26d are smoothly connected, unintentional turbulence of the air flow along the outer surface of the blade 4a is further suppressed. it can.

Therefore, the optical fiber sensors 23a and 23b can be arranged while further suppressing the deterioration of the aerodynamic performance of the blade 4a. Further, since the optical fiber sensors 23a and 23b are arranged on the outer surface of the blade 4a, they can be easily replaced when the optical fiber sensors 23a and 23b fail.

For example, when the optical fiber sensor 23a fails, first, the cover 26b is removed, the optical fiber cable 25c is removed from the connector 24b, and the optical fiber cable 25d is removed from the connector 24c. Then, the optical fiber sensor 23a and the optical fiber cables 25c and 25d are pulled out from the groove 31, and a new optical fiber sensor and the optical fiber cable are installed in the groove 31. Finally, the optical fiber sensor can be replaced by connecting the new optical fiber cable and the connectors 24b and 24c, respectively.

The optical fiber sensors 23a and 23b may be fixed to the groove 31 with an adhesive, a double-sided tape or the like. Thereby, the accuracy of measuring the strain of the blade 4a can be improved.

Further, the connectors 24a, 24b, 24c and the optical fiber cables 25a, 25b, 25c, 25d, 25e, and 25f do not have to be fixed to the groove 31 by using an adhesive, a double-sided tape or the like from the viewpoint of workability. By not fixing in the groove 31, the connection between the new optical fiber cable and the connectors 24a, 24b, 24c can be made easier.

Further, the covers 26a, 26b, 26c and 26d may be fixed to the side surface of the groove 31 by using an adhesive, a double-sided tape or the like. In this case, the covers 26a, 26b, 26c and 26d can be more firmly fixed to the main girder 15 on the negative pressure side, and the turbulence of the air flow can be further suppressed.

Example 4 of the present invention is shown in FIG. FIG. 7A shows a cross section of the optical fiber sensor 23b, the groove 31, the cover 26d, and the main girder 15 on the negative pressure side, which is another embodiment of embedding the optical fiber sensor 23b, and is a modification of the third embodiment. is there.

In Example 4 shown in FIG. 7A, a protrusion 26d1 is provided on one side surface of the cover 26d, and a second groove 31A is provided at a position on the side surface of the groove 31 corresponding to the protrusion 26d1 so as to be joined together. It was done like this.

That is, when the optical fiber sensor 23b is installed in the groove 31 and the opening of the groove 31 in which the optical fiber sensor 23b is installed is covered with the cover 26d, the protrusion 26d1 is provided on one side surface of the cover 26d. A second groove 31A is provided at a position on the side surface of the groove 31 corresponding to the protrusion 26d1 so as to fit with the protrusion 26d1, and the protrusion 26d1 of the cover 26d is fitted into the second groove 31A to open the opening of the groove 31. The cover 26d is used.

Although FIG. 7A illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

As a result, the same effects as those of the third embodiment can be obtained, and the covers 26a, 26b, 26c and 26d and the groove 31 can be provided in the second groove 31A by the protrusions of the respective cover covers 26a, 26b, 26c and 26d. They can be fitted mechanically, and the cover 26a, 26b, 26c and 26d and the groove 31 can be fixed more firmly. In addition, the positions of the covers 26a, 26b, 26c and 26d and the groove 31 can be more easily aligned.

In FIG. 7A, the protrusions are provided on one side surface of the covers 26a, 26b, 26c and 26d, but the protrusions may be provided on both side surfaces of the covers 26a, 26b, 26c and 26d. In this case, the covers 26a, 26b, 26c and 26d and the groove 31 can be fixed more firmly.

Example 5 of the present invention is shown in FIG. FIG. 7B shows a cross section of the optical fiber sensor 23b, the groove 31, the cover 26d, and the main girder 15 on the negative pressure side, which is another embodiment of embedding the optical fiber sensor 23b, and is a modification of the third embodiment. is there.

In the fifth embodiment shown in FIG. 7B, the width w'of the cover 26d is set to w'<D with respect to the diameter D of the cross section of the optical fiber sensor 23b.

Although FIG. 7B illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

As a result, the same effect as that of the third embodiment can be obtained, and the optical fiber sensor 23b is partially covered by the edge portion 31a of the opening of the groove 31, so that the optical fiber sensor 23b can be more firmly fixed to the main girder 15. Done.

Example 6 of the present invention is shown in FIG. FIG. 8 shows an example in which the optical fiber cables can be replaced more easily when the optical fiber cables 25a, 25b, 25c, 25d, 25e, 25f and 25g are damaged.

That is, in the sixth embodiment shown in FIG. 8, when the distance between the root of the blade 4a and the optical fiber sensor 23a or the distance between the optical fiber sensors 23a and 23b is large, the covers 26a and 26c between them are replaced by the cover 26a. 26a' and covers 26c and 26c' are divided into a plurality of pieces in the longitudinal direction of the blade 4a.

As a result, by splitting the optical fiber cables 25a, 25h, 25b or 25e, 25i, 25f laid at a long distance and connecting them with the connectors 24f and 24g, replacement is possible when the optical fiber cable is damaged. You can do it easier.

In this embodiment, the optical fiber sensors 23a and 23b are arranged on the main girder 15 on the suction side of the blade 4a, but may be arranged at other positions on the blade 4a, for example, on the outer surface of the shell 17 on the suction side. .. Further, the embedding of the two optical fiber sensors 23a and 23b has been shown, but the number of optical fiber sensors is not limited.

Further, in this embodiment, the composition of the covers 26a, 26b, 26c and 26d is not limited. For example, the coating material applied to the periphery of the groove 31 or the entire surface of the blade 4a and dried may be treated as a cover.

FIG. 9 shows a seventh embodiment of the present invention. FIG. 9 shows a cross section of the optical fiber sensor 23b, the groove 31, and the main girder 15 on the negative pressure side. The optical fiber sensor 23b and the main girder on the negative pressure side are coated with a polyurethane resin-based paint 33 that is often used for the purpose of protecting the blade 4a. 15 is an example of coating 15.

That is, the optical fiber sensor 23b is installed in the groove 31, and the portion including the opening of the groove 31 of the main girder 15 on the negative pressure side where the optical fiber sensor 23b is installed is coated with the polyurethane resin paint 33. It is a thing.

9 illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

As a result, the same effects as those of the third embodiment can be obtained, and since the optical fiber sensors 23a, 23b, 23c are protected from the atmosphere and the sunlight by the paint 33, the optical fiber sensors 23a, 23b, 23c and the adhesives are adhered. The weather resistance of the agent can be prevented.

In addition, since the film of the paint 33 generally has low strength, it can be easily removed and the optical fiber sensor can be replaced. After the optical fiber sensor is replaced, the replaced optical fiber sensor can be protected by coating with the paint 33 again. The present embodiment is not limited to the components of the paint 33.

Example 8 of the present invention is shown in FIG. FIG. 10 shows a cross section of the two optical fiber sensors 23b and 43b, the groove 31, the cover 26d and the main girder 15 on the negative pressure side, and the two optical fiber sensors 23b and 43b are arranged in parallel in the groove 31. In this example, the opening of the groove 31 in which the two optical fiber sensors 23b and 43b are arranged in parallel is covered with the cover 26d.

That is, the two optical fiber sensors 23b and 43b are arranged in parallel in the groove 31, and the opening of the groove 31 of the main girder 15 on the negative pressure side where the optical fiber sensor 23b is installed is covered with the cover 26d. is there. At this time, the width w′ of the cover 26d is set to w′≧2D with respect to the diameter D of the cross section of the optical fiber sensors 23b and 43b.

10 illustrates the optical fiber sensor 23b as an example, the other optical fiber sensors 23a and 23c have the same configuration.

As a result, the same effect as that of the third embodiment can be obtained, and in this embodiment, since the groove 31 is wide enough to allow the optical fiber sensors 23b and 43b to be arranged in parallel, it is easier to replace the optical fiber sensor. You can Further, by using one of the optical fiber sensors 23b and 43b as a strain temperature correction sensor, the strain measurement accuracy can be further improved.

Example 9 of the present invention is shown in FIG. FIG. 11A has a plurality of optical fiber sensors 23a, 23b, 23c, 43b, and at least two of these optical fiber sensors 23a, 23b, 23c, 43b (in this embodiment, the optical fiber sensor 23b and 43b) are arranged in parallel to configure the strain detection system 34.

That is, the strain detection system 34 of the ninth embodiment shown in FIG. 11A includes an interrogator 22, optical fiber sensors 23a, 23b, 23c and 43b, connectors 24a, 24b and 24c, and optical fiber cables 25a and 25b. 25c, 25d, 25e and 25f, and 45d and 45e, and in this embodiment, the optical fiber sensors 23b and 43b are arranged in parallel.

The optical fiber sensor 23b in the present embodiment is assumed to be a broken sensor, and the optical fiber cables 25d and 25e connected to the broken optical fiber sensor 23b are not connected to the connectors 24b and 24c.

In this way, the optical fiber sensors 23b and 43b are arranged in parallel, and the width w'of the cover 26d (26a, 26b, 26c) is set to the optical fiber sensor 23b as in the eighth embodiment shown in FIG. By setting w′≧2D with respect to the diameter D of the cross section of the optical fibers 43 and 43b, the connectors 24b and 24c are connected to the optical fiber sensor 43b without removing the defective optical fiber sensor 23b from the groove 31. All that is required is to reconnect the optical fiber cables 45d and 45e. As a result, the time required to replace the optical fiber sensor 23b can be shortened.

Embodiment 10 of the present invention is shown in FIG. FIG. 11B shows a first strain detection line in which optical fiber sensors 23a, 23b, 23c, connectors 24a, 24b, 24c and optical fiber cables 25a, 25b, 25c, 25d, 25e, 25f are connected in series. 36, and the optical fiber sensors 43a, 43b, 43c, the connectors 44a, 44b, 44c and the optical fiber cables 45a, 45b, 45c, 45d, 45e, 45f are connected in series to form the second strain detection line 37. And the first strain detection line 36 and the second strain detection line 37 are arranged in parallel.

That is, the strain detection system 34 of the tenth embodiment shown in FIG. 11B includes the interrogator 22, the optical fiber sensors 23a, 23b, 23c, the connectors 24a, 24b, 24c, and the optical fibers constituting the first strain detection line 36. The fiber cables 25a, 25b, 25c, 25d, 25e, 25f, the interrogator 22, and the optical fiber sensors 43a, 43b, 43c, the connectors 44a, 44b, 44c, and the optical fiber cable 45a that form the second strain detection line 37. , 45b, 45c, 45d, 45e, 45f.

Then, the optical fiber sensors 23a, 23b, 23c and the connectors 24a, 24b, 24c and the optical fiber cables 25a, 25b, 25c, 25d, 25e, 25f are connected in series to form the first strain detection line 36, The optical fiber sensors 43a, 43b, 43c, the connectors 44a, 44b, 44c and the optical fiber cables 45a, 45b, 45c, 45d, 45e, 45f are connected in series to form the second strain detection line 37, and The first strain detection line 36 and the second strain detection line 37 are arranged in parallel.

That is, as in the eighth embodiment shown in FIG. 10, the width w′ of the cover 26d (26a, 26b, 26c) is set to w′≧2D with respect to the diameter D of the cross section of the optical fiber sensors 23b and 43b. Then, the first strain detection line 36 and the second strain detection line 37 can be arranged in parallel in the groove 31.

Therefore, the redundancy of the strain detection system 34 is enhanced, and the temperature of the strain detection system 34 is measured by using the temperature correction sensor in either the first strain detection line 36 or the second strain detection line 37. The accuracy can be further improved.

In this embodiment, the optical fiber sensors 23a, 23b, 23c and the optical fiber sensors 43a, 43b, 43c are arranged on the main girder 15 on the negative pressure side of the blade 4a. However, for example, the outer surface of the shell 17 on the negative pressure side, etc. It may be arranged at another position of the blade 4a. Further, the number of optical fiber sensors is an example, and the number of optical fiber sensors is not limited in the present embodiment.

Example 11 of the present invention is shown in FIG. In Example 11 shown in FIG. 12, a cover for covering the optical fiber sensor installed in the groove described above is provided with an additional function.

The blades of a wind power generation system are often provided with attachment parts such as a Vortex generator, a spoiler, and a Gurney flap for the purpose of improving power generation efficiency.

For example, the vortex generator intentionally forms a convex surface on the surface of the blade and disturbs the air flow along the surface of the blade to suppress the separation of the boundary layer and improve the reliability of the blade strength.

FIG. 12 shows a cross section of the optical fiber sensor 23b, the groove 31, the cover 26d, and the main girder 15 on the negative pressure side. A vortex generator 51 is provided on the outer surface of the cover 26d. The material of the vortex generator 51 is assumed to be FRP, like the blade 4a. On the other hand, the shape of the outer surface of the cover 26d is smoothly connected to the shape of the outer surface of the main girder 15 on the negative pressure side around the groove 31.

Therefore, since the outer surface of the blade 4a and the outer surface of the cover 26d are smoothly connected, unintentional disturbance of the air flow along the outer surface of the blade 4a can be further suppressed. In addition, since the vortex generator 51 is provided on the outer surface of the cover 26d, the power generation efficiency of the blade 4a can be further increased. Further, since the optical fiber sensor 23b is arranged on the outer surface of the blade 4a, it can be easily replaced when the optical fiber sensor 23b fails.

The above-mentioned vortex generator 51 is fixed to the cover 26d with an adhesive or a double-sided tape.

In this embodiment, the optical fiber sensor 23b is arranged on the main girder 15 on the negative pressure side of the blade 4a, but it may be arranged on another position of the blade 4a, for example, on the outer surface of the shell 17 on the negative pressure side. . Further, the number of optical fiber sensors is not limited.

Although the cover 26d is provided with the vortex generator 51 in this embodiment, the cover 26d may be provided with other attachment components such as a spoiler and a gurney flap. The material of the vortex generator 51 is not limited.

It should be noted that the present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, with respect to a part of the configuration of each embodiment, other configurations can be added/deleted/replaced.

1... Windmill, 2... Tower, 3... Nacelle, 4a, 4b, 4c... Blade, 5... Hub, 6... Rotor, 11... Leading edge, 12... Trailing edge, 13... Negative pressure side, 14... Positive pressure side, 15... Negative pressure side main girder, 16... Positive pressure side main girder, 17... Negative pressure side outer skin (shell), 18... Positive pressure side outer skin (shell), 19a... Front edge side web, 19b... Rear edge side web, 21, 32, 34... Strain detection system, 22... Interrogator, 23a, 23b, 23c, 43a, 43b, 43c... Optical fiber sensor, 24a, 24b, 24c, 24d, 24e, 44a, 44b, 44c... Connector, 25a, 25b, 25c, 25d, 25e, 25f, 25g, 25h, 25i, 45a, 45b, 45c, 45d, 45e, 45f... Optical fiber cable, 26a, 26b, 26c, 26d, 26', 26c'... Cover, 26d1... Protrusion, 31... Groove, 31a... Edge portion of groove opening, 31A... Second groove, 33... Paint, 36... First strain detection line, 37... Second strain detection line, 51... Vortex generator.

Claims (15)

A wind turbine blade comprising at least one blade that constitutes a rotor that receives wind and rotates,
A wind turbine blade, wherein a groove is provided on an outer surface of the blade, and a strain detection system including at least one optical fiber sensor is installed along the groove. The wind turbine blade according to claim 1,
A plurality of the optical fiber sensors are arranged along the longitudinal direction of at least one of the blades. The wind turbine blade according to claim 1 or 2, wherein
The blade is configured to include a main girder and an outer skin (shell) on the suction side, a main girder and an outer skin (shell) on the pressure side, a web on the leading edge side and a web on the trailing edge side,
The wind turbine blade, wherein the optical fiber sensor is embedded along the main girder of the blade or the groove provided on the outer surface of the shell. The wind turbine blade according to any one of claims 1 to 3,
The strain detection system, a light source for irradiating a wavelength of a wide band, an interrogator equipped with a detector for detecting the wavelength and intensity of reflected light and an amount of change in wavelength to a strain, and a plurality of the optical fiber sensors, A wind turbine blade comprising an optical fiber cable connecting the interrogator and one optical fiber sensor, and a plurality of the optical fiber cables connecting the remaining optical fiber sensors. The wind turbine blade according to claim 4,
A connector is installed in the middle of each of the optical fiber cables connecting the interrogator and one of the optical fiber sensors, and the plurality of optical fiber cables connecting between the remaining optical fiber sensors,
The optical fiber cable on the side of the interrogator and the optical fiber cable on the side of one optical fiber sensor are detachably connected via the connector, and a plurality of each of the remaining optical fiber sensors are connected. A windmill blade, wherein the optical fiber cable is detachably connected midway through the connector. The wind turbine blade according to claim 5,
The optical fiber sensor and the connector are connected in series in a substantially straight line shape, or are connected in series in a curved shape, or the optical fiber sensor is connected in parallel by branching from at least one of the plurality of connectors. A windmill blade that is characterized by being. The wind turbine blade according to claim 3,
The width w of the opening of the groove is w≧D with respect to the diameter D of the cross section of the optical fiber sensor, and the depth h of the groove is h≧D with respect to the diameter D of the cross section of the optical fiber sensor. A windmill blade characterized by: The wind turbine blade according to claim 3,
The width w of the opening of the groove is w<D with respect to the diameter D of the cross section of the optical fiber sensor, and the depth h of the groove is h≧D with respect to the diameter D of the cross section of the optical fiber sensor. The wind turbine blade is characterized in that the optical fiber sensor is partially covered by an edge portion of the opening of the groove. The wind turbine blade according to claim 7 or 8,
A wind turbine blade, wherein an opening of a groove provided on an outer surface of the blade is covered (covered) with a cover. The wind turbine blade according to claim 9,
A wind turbine blade, characterized in that a projection is provided on at least one side surface of the cover, and a second groove is provided on a side surface of the groove corresponding to the projection so that both are combined. The wind turbine blade according to claim 9 or 10,
The wind turbine blade, wherein the outer surface shape of the cover is smoothly connected to the outer surface shape of the main girder around the groove. The wind turbine blade according to any one of claims 9 to 11,
The wind turbine blade, wherein the cover is divided into a plurality of pieces in the longitudinal direction of the blade. The wind turbine blade according to claim 7 or 8,
A wind turbine blade, wherein a portion including an opening of the groove in which the optical fiber sensor is installed is coated with a paint. The wind turbine blade according to any one of claims 9 to 12,
A wind turbine blade, wherein any one of a vortex generator, a spoiler, and a gurney flap is installed on the outer surface of the cover. A wind power generation system including a tower, a nacelle installed on the upper part of the tower so as to be rotationally driven in a horizontal plane, and a rotor connected to the nacelle and configured with at least one windmill blade and a hub. There
The wind turbine blade according to claim 1, wherein the wind turbine blade is the wind turbine blade according to any one of claims 1 to 14.

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