阅读说明：本技术 一种风电叶片监测用光纤光栅传感器 (Fiber bragg grating sensor for monitoring wind power blade ) 是由 邢晓坡 黄司晨 于 2020-07-17 设计创作，主要内容包括：本发明公开了一种风电叶片监测用光纤光栅传感器,包括光纤、布拉格光栅以及玻璃纤维布、表面毡,所述玻璃纤维布为传感器基体,所述光纤沿传感器基体长度方向居中铺设,在光纤铺设长度居中位置刻蚀有布拉格光栅,所述光纤上面使用一层风电叶片用表面毡进行敷设保护层,所述光纤、玻璃纤维布和表面毡抽真空灌注成型为光纤光栅传感器。本发明设计先进、安装简便、寿命长,线性度好,无金属零部件可以做到防雷击,相对于风电叶片其他形式的监测传感器成本较低并具有很强的应用扩展性。(The invention discloses a fiber bragg grating sensor for monitoring wind power blades, which comprises an optical fiber, a Bragg grating, glass fiber cloth and a surface felt, wherein the glass fiber cloth is a sensor substrate, the optical fiber is laid in the middle along the length direction of the sensor substrate, the Bragg grating is etched in the middle of the laying length of the optical fiber, a protective layer is laid on the optical fiber by using the surface felt for the wind power blades, and the optical fiber, the glass fiber cloth and the surface felt are formed into the fiber bragg grating sensor by vacuum pumping and pouring. The invention has advanced design, simple and convenient installation, long service life and good linearity, can prevent lightning stroke without metal parts, has lower cost and strong application expansibility compared with other monitoring sensors of wind power blades.)

1. A fiber bragg grating sensor for monitoring wind power blades is characterized by comprising an optical fiber (1), a Bragg grating (3), glass fiber cloth (5) and a surface felt (4),

glass fiber cloth (5) are the sensor base member, optical fiber (1) are laid along sensor base member length direction between two parties, and it has Bragg grating (3) to lay length position etching between two parties at optical fiber (1), use one deck wind-powered electricity generation blade to lay the protective layer with surperficial felt (4) above optical fiber (1), glass fiber cloth (5) and surperficial felt (4) evacuation infusion shaping.

2. The fiber bragg grating sensor for monitoring the wind turbine blade as claimed in claim 1, wherein the fiber bragg grating sensor can be connected in series in a fusion mode, the joints at two sides of the optical fiber (1) can be fused with the optical fibers (1) of other sensors, and the position of each sensor is identified through the difference of the central wavelength of the bragg grating (3).

3. The fiber bragg grating sensor for monitoring the wind power blade as claimed in claim 1, wherein the glass fiber cloth (5) is biaxial glass fiber cloth for producing the wind power blade, and the thickness of the biaxial glass fiber cloth is 0.4 mm-0.5 mm.

4. The fiber bragg grating sensor for monitoring the wind turbine blade as claimed in claim 1, wherein the gram weight of the surface felt (4) is 30-50 g per square meter.

5. The fiber bragg grating sensor for monitoring the wind turbine blade as claimed in claim 1, wherein the optical fiber (1) is a functional optical fiber and a fiber cable with a diameter of 150 μm to 200 μm.

6. The fiber bragg grating sensor for monitoring the wind power blade as claimed in claim 1, wherein the lower surface of the glass fiber cloth (5) of the fiber bragg grating sensor is bonded with the inner surface of the wind power blade.

7. The fiber bragg grating sensor for monitoring the wind blades as claimed in claim 1, wherein the bragg grating (3) is externally provided with a hard non-metal protective sleeve.

8. The fiber bragg grating sensor for monitoring the wind turbine blade according to claim 1, wherein the fiber bragg grating sensor is adhered to a blade cracking key monitoring area.

9. The fiber bragg grating sensor for monitoring the wind turbine blade as claimed in claim 1, wherein a silicon rubber protective layer is adhered to the surface of the fiber bragg grating sensor.

Technical Field

The invention belongs to the technical field of wind power blade operation state monitoring, relates to a sensor developed aiming at materials, structures and operation environments of wind power generation blades, and particularly relates to a fiber bragg grating sensor for monitoring wind power blades.

Background

According to the statistics of the industry, in 2019, 2574 ten thousand kilowatts of newly-added grid-connected wind power installation machines are added, the accumulated grid-connected installed capacity reaches 21005 thousand kilowatts, and the wind power installation machines account for 10.4 percent of the total installed capacity of power generation. China currently has more than 10 ten thousand grid-connected wind generating sets, and wind blades are key components for energy conversion of the wind generating sets, so that the cost accounts for about 20% of the total cost of the sets, but the failure rate is high. According to statistics of energy companies, shutdown accidents caused by damage and failure of blades are as high as 32% of total accidents, and huge economic losses are brought by power generation loss and replacement of damaged blades.

The real-time monitoring of the operation state of the blade can timely find out the hidden trouble which can cause the catastrophic damage of the blade, and the proper treatment measures are taken to prevent the blade from being burnt. Most work of wind-powered electricity generation blade is in adverse circumstances areas such as high altitude mountain area, coast or sea, and there are difficult problems of difficult operation, with high costs, can not real-time supervision in conventional inspection monitoring means such as manual work, unmanned aerial vehicle, and rely on conventional electric measuring sensor to monitor and have very big thunder attraction risk again, and the market is urgent to need high-efficient economy and safe monitoring sensor to ensure unit normal operating, reduces economic loss.

Disclosure of Invention

To there is technical problem among the above-mentioned prior art, the utility model aims at providing a fiber grating sensor for wind-powered electricity generation blade monitoring.

In order to realize the purpose of the invention, the invention provides a fiber bragg grating sensor for monitoring a wind power blade, which comprises an optical fiber, a Bragg grating, glass fiber cloth and a surface felt,

the glass fiber cloth is a sensor base body, the optical fiber is laid in the middle along the length direction of the sensor base body, the Bragg grating is etched in the middle of the laying length of the optical fiber, a surface felt for the wind power blade is used for laying a protective layer on the optical fiber, and the optical fiber, the glass fiber cloth and the surface felt are subjected to vacuum pumping and filling molding to form the optical fiber grating sensor.

The fiber bragg grating sensors can be connected in series in a fusion mode, the joints on two sides of the optical fiber can be fused with optical fibers of other sensors, and the position of each sensor is identified through the difference of the central wavelength of the bragg grating.

The glass fiber cloth is biaxial glass fiber cloth for producing wind power blades, and the thickness of the biaxial glass fiber cloth is 0.4-0.5 mm.

Wherein the gram weight of the surfacing mat is 30-50 g per square meter.

Wherein, the optical fiber adopts functional optical fiber and is an optical fiber cable with the diameter of 150-200 μm.

The lower surface of the glass fiber cloth of the fiber grating sensor is connected with the inner surface of the wind power blade in a bonding mode.

The Bragg grating is externally provided with a hard nonmetal protective sleeve, and the protection structure is adopted under the condition that the fiber grating sensor is used as a temperature sensor.

The fiber grating sensor is adhered to a major blade cracking monitoring area, and is arranged in the area under the condition that the fiber grating sensor is used as a fiber grating sensor for cracking monitoring.

And a silicon rubber protective layer is adhered to the surface of the fiber grating sensor.

Compared with the prior art, the fiber grating sensor special for monitoring the real-time state of the wind turbine blade of the wind generating set has the beneficial effects that the fiber grating sensor is special for monitoring the real-time state of the wind turbine blade of the wind generating set, and can realize uninterrupted monitoring on blade vibration, temperature, load, ice coating and surface cracking of dangerous positions. According to the wavelength change signal sent by the sensor, after analysis, the type and the fault level of abnormal conditions of wind field watchers are timely and automatically informed, shutdown inspection and processing can be carried out, safety production accidents are prevented from occurring, and personnel and property loss is avoided.

The invention has advanced design, simple and convenient installation, long service life and good linearity, can prevent lightning stroke without metal parts, has lower cost and strong application expansibility compared with other monitoring sensors of wind power blades.

Drawings

FIG. 1 is a schematic top view of a fiber grating sensor for monitoring wind turbine blades in the present application;

FIG. 2 is a schematic cross-sectional view of a fiber grating sensor for monitoring a wind turbine blade according to the present application;

FIG. 3 is a diagram illustrating an exemplary arrangement of a fiber grating sensor for monitoring wind blades in the present application.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict.

The invention is described in further detail below with reference to the figures and specific examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

As shown in fig. 1 to fig. 3, the present embodiment provides a fiber bragg grating sensor 2 for monitoring a wind turbine blade of a wind turbine generator system, including an optical fiber 1, a bragg grating 3, a glass fiber cloth 5, and a surface felt 4. The glass fiber cloth 5 is used as a sensor substrate, so that the sensor has the same service life as the measured object. Optical fiber 1 lays along base member length direction between two parties, and it has bragg grating 3 to lay length position etching between two parties at optical fiber, uses one deck wind-powered electricity generation blade to lay the protective layer with surperficial felt 4 above optical fiber 1, by optical fiber 1, two axial glass fiber cloth 5 and surperficial felt 4 evacuation infusion shaping for whole optical fiber sensor 2, optical fiber sensor 2 can carry out a plurality of series connections through the mode of butt fusion, discerns the position of every sensor by the difference of bragg grating 3 central wavelength. The fiber grating sensors connected in series can be used as sensors with different purposes, such as a fiber grating sensor 7 for load measurement and a fiber grating sensor 8 for trailing edge crack monitoring, and functional measurement is realized according to the definition of each sensor.

The above-mentioned vacuum infusion molding is performed by using a conventional technique in the art to evacuate the optical fiber 1, the biaxial glass cloth 5, and the surfacing mat 4 and infuse the resin.

Wherein, the glass fiber cloth 5 adopts a common biaxial glass fiber cloth for producing wind power blades, and preferably adopts an alkali-free type with the thickness of 0.4 mm-0.5 mm.

Wherein, the surface felt 5 adopts a wind power blade to produce a common surface felt. Preferably, an alkali-free type is used, having a grammage of 30g to 50g per square meter.

The optical fiber 1 is a functional optical fiber, which is beneficial to the inscription of the Bragg grating, and preferably an optical fiber cable with the diameter of 150-200 μm is used.

When the fiber bragg grating sensor 2 is used for mounting the inner surface of the wind power blade, a normal-temperature fast-curing adhesive (502 and the like) is needed, when the fiber bragg grating sensor is pasted in a low-temperature environment (below zero), the cleaned bonding surface of the inner cavity of the blade and the bonding surface of the sensor can be preheated by hot air for 20 seconds through an electrothermal blower, and gluing and pasting operations are performed after the preheating.

The joints at two sides of the optical fiber 1 of the optical fiber grating sensor 2 can be welded with other sensors to be connected in series, a plurality of sensors can be welded in series to form a measuring channel, and the number of the sensors which can be connected in series in each measuring channel is determined by the range of the central wavelength of the Bragg grating 3. The number and the sticking positions of the fiber grating sensors can be adjusted according to a predicted monitoring scheme, and the influence of adhesion of blade structural parts needs to be considered in the routing path of the optical fiber.

Wherein, the external hard nonmetal protective case of bragg grating 3 makes it avoid bearing the strain, can only monitor temperature change, can monitor the temperature and be used for strain gauge sensor temperature compensation.

The fiber bragg grating sensors 2 are adhered to the blade cracking key monitoring area, and because the central wavelengths distributed when the bragg gratings 3 of each sensor are engraved are different, addressing can be carried out according to the demodulated median wavelength range and the corresponding relation between the sensors and the positions.

Wherein, set up location auxiliary line 6 on the blade and be used for assisting the location work when accomplishing the sensor bonding, the blade bonding surface is drawn "ten" style of calligraphy location line with the scriber after the cleaning of polishing, and optic fibre 1 aligns with the horizontal line, and location auxiliary line 6 aligns with the vertical line, can adopt the finger-pressing method to catch up out bonding face bubble after the alignment, guarantees the bonding quality.

After the bonding construction of the fiber grating sensor 2 is finished, a silicon rubber protective layer is adhered to the surface, so that the weather resistance of the sensor can be improved.

It should be noted that the optical fiber 1 is used to connect the sensors inside the blade and to connect to a dedicated demodulator outside the blade through the hub, and its length needs to be estimated in advance and an appropriate margin is taken into account. The length of the optical fiber between the sensors also needs to be calculated in advance, and the welding of the sensors is completed before construction.

It should be noted that the fiber grating sensor is based on a fiber grating sensing technology, and the technology can ensure that the sensor is not interfered in a high electromagnetic radiation environment of a wind turbine generator system. The sensor substrate adopts the glass fiber cloth and resin with equal strength of the wind power blade, and the production process adopts the vacuum infusion method with the same wind power blade, so that the sensor can reach the life cycle with the same wind power blade. The fiber grating sensor is adhered on site by using a normal-temperature quick-setting adhesive, and after the adhesion is finished, a tetrafluoroethylene film is used for covering and applying a finger pressure method to discharge bubbles on an adhesion surface, so that the adhesion quality can be ensured. After the fiber grating sensor is bonded and cured, the surface of the fiber grating sensor needs to be covered with flexible, ageing-resistant and insulating silicon rubber for isolated air protection, and the influence of high temperature and high humidity on the service life of the fiber grating sensor can be obviously reduced when the fiber grating sensor is used in coastal or offshore areas. The fiber bragg grating sensor can provide stable and reliable basic strain and temperature signals according to the requirement of intelligent blade design, and can be used as a peripheral nerve unit for large data analysis of the blade management of the whole wind power plant. The fiber grating sensor can be simultaneously applied to the strength test of the wind power blade, replaces the traditional resistance type strain gauge, and can obviously improve the stability and the linearity of strain test data when being particularly used for fatigue strength test. The fiber grating sensor can be applied to wind power generation blades and can also be applied to state monitoring of other similar glass fiber reinforced plastic composite material structures, such as yachts, cabin covers of wind generating sets and the like.

The technical means not described in detail in the present application are known techniques.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.