A sensor probe and fiber grating wind speed sensor

Abstract

The application provides a sensor probe and a fiber grating wind speed sensor, and relates to the technical field of wind speed sensors.The sensor probe comprises a flow guide groove;the flow guide groove is a single-rotation-direction asymmetric spiral structure;the surface of the flow guide groove is sequentially covered with a first coating, a second coating and a third coating from outside to inside;the first coating is a multi-gradient coating and is used for grading dust filtration;the second coating is used for waterproofing;and the third coating is used for dust decomposition.The sensor probe can use the centrifugal force generated by the asymmetric spiral structure to throw dust particles to the outer edge of the channel and maintain air flow passability by adopting the flow guide groove with the single-rotation-direction asymmetric spiral structure.The surface of the flow guide groove is covered with three kinds of coatings, dust filtration and waterproofing can be realized at the physical level, dust decomposition can be realized at the chemical level, physical and chemical dual dust prevention is realized, the influence of air humidity and dust concentration on the detection result of the sensor probe is reduced, and the measurement accuracy and stability of the fiber grating wind speed sensor are improved.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the technical field of wind speed sensor, in particular to a sensor probe and a fiber grating wind speed sensor. BACKGROUND

[0002] There are toxic and flammable gases in the coal mine, which can easily cause poisoning, explosion and other operation risks. Therefore, maintaining ventilation is the premise of ensuring safety in production, and it is necessary to detect the wind speed in mine production. The existing wind speed sensor includes mechanical, thermal, ultrasonic and pressure types, which directly or indirectly convert the wind speed through electric signals to obtain the wind speed. When applied in the mine, there are safety hazards.

[0003] The mechanical wind speed sensor measures the wind speed by the force of the wind on the mechanical parts, but it has a start-up wind speed limit and is not suitable for low wind speed measurement, and is greatly affected by the environment; the thermal wind speed sensor calculates the wind speed by measuring the heat loss of the heating element in the airflow, but there are many fluid dynamic interference factors in the mine, and the hot wire is easy to break; the ultrasonic wind speed sensor calculates the wind speed by measuring the time difference of ultrasonic wave propagation in the air, but it has high requirements for installation position and angle; the pressure type wind speed sensor calculates the wind speed by measuring the dynamic pressure and static pressure difference of the airflow, but it is not sensitive to low wind speed and is easy to be blocked by dust and particles. The fiber grating wind speed sensor is based on optical signal transmission and is not affected by electromagnetic field interference, has high sensitivity, corrosion resistance and other advantages.

[0004] However, in the actual production process of the mine, environmental factors such as high air humidity and high dust concentration can cause errors in the detection results of the sensor probe, affect the normal operation of the fiber grating wind speed sensor, and result in low measurement accuracy and poor stability. SUMMARY

[0005] To solve the above problems, the present application provides a sensor probe and a fiber grating wind speed sensor, which can solve the technical problems of low measurement accuracy and poor stability of the wind speed sensor.

[0006] The first aspect of the present application provides a sensor probe, comprising: a flow guide groove; the flow guide groove is a single helical asymmetric structure; the surface of the flow guide groove is sequentially covered with a first coating, a second coating and a third coating from outside to inside; the first coating is a multi-gradient coating for grading dust filtration, the second coating is used for waterproofing, and the third coating is used for decomposing dust.

[0007] The sensor probe adopts a single-rotation asymmetric spiral structure flow guide groove, and centrifugal force generated by the asymmetric spiral structure is used to throw dust particles to the outer edge of the channel and maintain air flow passability. The surface of the flow guide groove is covered with three coatings, which can achieve dust filtration and waterproof at the physical level, dust decomposition at the chemical level, and dual dust prevention of physics and chemistry, reduce the influence of air humidity and dust concentration on the detection results of the sensor probe, and improve the measurement accuracy and stability of the fiber grating wind speed sensor.

[0008] In an implementation form of the first aspect, the flow guide groove is a single-rotation asymmetric spiral structure, and includes: the pitch of the flow guide groove gradually decreases from the inlet to the outlet; the groove depth of the flow guide groove gradually increases from the inlet to the outlet; the width of the flow guide groove gradually decreases from the outside to the inside; and the angle between the groove channel of the flow guide groove and the axis gradually increases from the inlet to the outlet.

[0009] In an implementation form of the first aspect, the pitch of the flow guide groove at the inlet is 10 mm, the pitch of the flow guide groove at the outlet is 5 mm; the groove depth of the flow guide groove at the inlet is 0.5 mm, the groove depth of the flow guide groove at the outlet is 1.5 mm; the width of the flow guide groove at the outside is 1.2 mm, the width of the flow guide groove at the inside is 0.8 mm; and the angle between the groove channel of the flow guide groove and the axis at the inlet is 15°, the angle between the groove channel of the flow guide groove and the axis at the outlet is 45°.

[0010] The flow guide groove of the sensor probe adopts a gradual change design in pitch, groove depth, groove width, and groove channel-axis angle. The pitch gradually decreases from the inlet to the outlet, which can enhance the centrifugal force, gradually compress the airflow, and reduce the initial flow resistance to improve the separation efficiency of dust; the groove depth gradually increases from the inlet to the outlet, which can accelerate airflow rotation; the groove width gradually decreases from the outside to the inside, which can guide dust to move outward, and the narrow groove at the inside can maintain the core airflow speed, and the wide groove at the outside can capture dust; and the angle between the groove channel and the axis gradually increases from the inlet to the outlet, which can gradually enhance the centrifugal effect.

[0011] In an implementation form of the first aspect, the first coating is a porous coating, which includes an outer layer, a middle layer, and an inner layer; the outer layer has a pore size of 10 um and is used to filter coarse particle dust; the middle layer has a pore size of 5 um and is used to filter medium particle dust; and the inner layer has a pore size of 1 um and is used to filter fine particle dust.

[0012] The first coating covering the flow guide groove of the sensor probe is a three-layer porous coating, which can filter coarse particle dust, medium particle dust, and fine particle dust in stages, slow down the clogging speed, and prolong the service life of the coating.

[0013] In an implementation form of the first aspect, the porosity of the first coating is greater than 40%.

[0014] The porosity of the first coating covering the flow guide groove of the sensor probe is greater than 40%, which can ensure the passability of the airflow, reduce the probability of dust adhering to the surface of the sensor probe, and improve the performance of the fiber grating wind speed sensor.

[0015] In an implementation form of the first aspect, the first coating is a porous ceramic coating; the second coating is a hydrophobic material coating; and the third coating is a nano coating with heat conduction performance.

[0016] In an implementation form of the first aspect, the first coating is a porous alumina ceramic coating; the second coating is a fluorosilane coating; and the third coating is a titanium dioxide graphene nano coating.

[0017] In an implementation form of the first aspect, the thickness of the first coating is 100 nm; and the contact angle between the second coating and water is greater than 150°.

[0018] The first coating covering the flow guide groove of the sensor probe is a porous alumina ceramic coating with a thickness of 100 nm, which can improve the service life of the coating. The second coating is a fluorosilane coating with hydrophobic properties, which can prevent water. The third coating is a titanium dioxide graphene nano coating with heat conduction performance, which can decompose organic dust under photocatalysis, reducing the influence of air humidity and dust concentration on the sensor probe.

[0019] The second aspect of the present application provides a fiber grating wind speed sensor, which comprises the sensor probe provided by the first aspect and any possible implementation form thereof, and a fiber grating; and the fiber grating is arranged inside the flow guide groove of the sensor probe.

[0020] In an implementation form of the second aspect, the fiber grating wind speed sensor further comprises a pump source, an optical cable, and a fiber grating demodulator; the top end of the sensor probe is connected to the pump source, and the bottom end of the sensor probe is connected to the optical cable; and the fiber grating is connected to the fiber grating demodulator.

[0021] The fiber grating wind speed sensor sets the fiber grating inside the flow guide groove of the sensor probe, which can reduce the influence of external dust and humidity on the measurement accuracy of the fiber grating, and improve the measurement accuracy and stability of the fiber grating wind speed sensor.

[0022] According to the above technical solutions, the present application provides a sensor probe and a fiber grating wind speed sensor. The sensor probe comprises a flow guide groove; the flow guide groove has a single-helical asymmetric spiral structure; the surface of the flow guide groove is sequentially covered with a first coating, a second coating, and a third coating from outside to inside; the first coating is a multi-gradient coating for filtering dust in stages; the second coating is used for waterproofing; and the third coating is used for decomposing dust.

[0023] The aforementioned sensor probe employs a single-rotation asymmetric spiral structure in its guide channel. This structure utilizes centrifugal force to deflect dust particles to the outer edge of the channel while maintaining airflow. The guide channel surface is coated with three layers, providing physical dust filtration and waterproofing, and chemical dust decomposition. This dual physical and chemical dust protection reduces the impact of air humidity and dust concentration on the sensor probe's detection results, improving the measurement accuracy and stability of the fiber Bragg grating anemometer. Attached Figure Description

[0024] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of a sensor probe provided in an embodiment of this application;

[0026] Figure 2 This is a flowchart of a method for detecting wind speed using a fiber optic grating anemometer, provided in an embodiment of this application.

[0027] Figure 3 This is a schematic diagram of a fiber Bragg grating wind speed sensor structure provided in an embodiment of this application.

[0028] Illustration markings:

[0029] 1-Guide channel; 101-Inlet; 102-Outlet; 201-Top; 202-Bottom;

[0030] 301 - Sensor probe; 302 - Pump source; 303 - Optical cable; 304 - Fiber grating demodulator. Detailed Implementation

[0031] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application.

[0032] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0033] The terms "first", "second", "third", and the like in the specification of the present application and in the above-described drawings are used to distinguish similar or like objects or entities, and do not necessarily mean to limit a specific order or sequence, unless otherwise specified. It should be understood that the terms used in this way can be interchanged under appropriate circumstances.

[0034] To facilitate the understanding of the scheme, the related terms are explained as follows:

[0035] Fiber grating: a passive optical device with a periodic refractive index modulation structure formed in the fiber core by ultraviolet exposure and other technologies. Its core feature is that the refractive index of the core changes periodically along the fiber axis. This periodic structure selectively affects specific wavelengths of light. When light is transmitted in the fiber, light that meets the Bragg condition (i.e., the matching relationship between the wavelength of light and the refractive index period) is strongly reflected, while other wavelengths of light can be transmitted smoothly.

[0036] Fiber grating wind speed sensor: an optical sensing device that uses fiber grating as the core sensitive element to measure the speed of air movement (wind speed). Its core principle is to convert the mechanical action of wind on the sensor into a detectable optical signal through the sensitivity of fiber grating to physical deformation, thereby realizing quantitative measurement of wind speed.

[0037] Flow guide groove: the core function of the flow guide groove in the fiber grating wind speed sensor is to guide, straighten or focus the airflow, so that the wind speed signal is more stable and accurate to the sensitive components coupled with the fiber grating, thereby improving the measurement accuracy and reliability of the sensor.

[0038] The fiber grating wind speed sensor is based on optical signal transmission and is not affected by electromagnetic field interference, has high sensitivity, corrosion resistance and other advantages, and is widely used in the field of mine wind speed detection.

[0039] However, when using a fiber grating wind speed sensor to detect wind speed, water vapor and dust in the mine air may adhere to the sensor probe, causing blockage of the surface of the sensor probe, reducing the detection accuracy of the sensor probe, and affecting the normal operation of the fiber grating wind speed sensor, resulting in low measurement accuracy and poor stability.

[0040] To solve the above technical problems, the sensor probe 301 provided by the embodiments of the present application can reduce the influence of dust and water vapor on wind speed detection accuracy and solve the technical problems of low measurement accuracy and poor stability of the fiber grating wind speed sensor.

[0041] Figure 1 is a structural schematic diagram of a sensor probe provided by the embodiments of the present application.

[0042] In combination with Figure 1As shown, the sensor probe 301 provided by the embodiments of the present application comprises: a flow guide groove 1; the flow guide groove 1 is a single-rotation-direction asymmetric spiral structure; the surface of the flow guide groove 1 is sequentially covered by a first coating layer, a second coating layer and a third coating layer from outside to inside; the first coating layer is a multi-gradient coating layer, used for grading filtering dust, the second coating layer is used for waterproofing, and the third coating layer is used for decomposing dust.

[0043] In some embodiments, the airflow in a symmetric flow field is easy to flow smoothly along a "uniform path" (such as laminar flow in a symmetric pipe), with weak disturbance and dispersed effect; in order to break the "symmetric and smooth" flow field in the natural state, the flow guide groove 1 adopts a single-rotation-direction asymmetric spiral structure to force the airflow to flow along a spiral path. Moreover, in order to improve the sensitivity of the sensor probe 301 in performing wind speed detection, it is necessary to enhance the local vortex flow. The single-rotation-direction asymmetric spiral structure can make the airflow be forced to twist and be pressed, forming an asymmetric pressure distribution and flow direction, and the originally uniform flow field is torn, achieving the effect of enhancing the local vortex flow.

[0044] Further, the flow guide groove 1 with the single-rotation-direction asymmetric spiral structure has a flow guide characteristic, and the centrifugal force generated by the asymmetric spiral structure is used to throw dust particles to the outer edge of the channel and maintain the airflow passability. This can reduce impurity accumulation, improve the detection accuracy of the sensor probe 301, and increase the durability of the sensor.

[0045] Exemplarily, Figure 1 The sensor probe 301 in the above embodiment is designed as a bionic shark gill structure, and a 3D printing or micro-processing technology is used to design a single-rotation-direction asymmetric spiral structure flow guide groove 1 (similar to a turbine blade) on the outside of the sensor probe 301. The fluid dynamics principle is used to make dust particles be discharged in a tangential direction under the action of centrifugal force, so as to reduce dust deposition.

[0046] In one implementation, the single-rotation-direction asymmetric spiral structure of the flow guide groove 1 comprises: the pitch of the flow guide groove 1 gradually decreases from the inlet 101 to the outlet 102; the groove depth of the flow guide groove 1 gradually increases from the inlet 101 to the outlet 102; the width of the flow guide groove 1 gradually decreases from the outside to the inside; and the included angle between the channel of the flow guide groove 1 and the axis gradually increases from the inlet 101 to the outlet 102.

[0047] The pitch gradually decreasing from the inlet 101 to the outlet 102 can enhance the centrifugal force, gradually compress the airflow, reduce the initial flow resistance, and improve the separation efficiency of dust; the groove depth gradually increasing from the inlet 101 to the outlet 102 can accelerate the rotation of the airflow; the groove width gradually decreasing from the outside to the inside can guide the dust to move outward, and the narrow groove in the inside can maintain the core airflow speed, and the wide groove in the outside can capture the dust; and the included angle between the channel and the axis gradually increasing from the inlet 101 to the outlet 102 can gradually enhance the centrifugal effect.

[0048] Exemplarily, as shown inFigure 1 As shown, the pitch of the guide groove 1 at the inlet 101 is 10 mm, the pitch of the guide groove 1 at the outlet 102 is 5 mm, and the pitch of the guide groove 1 gradually decreases from 10 mm to 5 mm from the inlet 101 to the outlet 102; the groove depth of the guide groove 1 at the inlet 101 is 0.5 mm, the groove depth of the guide groove 1 at the outlet 102 is 1.5 mm, and the groove depth of the guide groove 1 gradually increases from 0.5 mm to 1.5 mm from the inlet 101 to the outlet 102; the width of the outer side of the guide groove 1 is 1.2 mm, the width of the inner side of the guide groove 1 is 0.8 mm, and the width of the guide groove 1 gradually decreases from 1.2 mm to 0.8 mm from the outer side to the inner side; the angle between the channel of the guide groove 1 at the inlet 101 and the axis is 15°, the angle between the channel of the guide groove 1 at the outlet 102 and the axis is 45°, and the angle between the channel of the guide groove 1 gradually increases from 15° to 45° from the inlet 101 to the outlet 102.

[0049] In some embodiments, the environment under the mine has the characteristics of high air humidity and high dust concentration. Therefore, in order to avoid the water vapor and dust particles in the air from adhering to the sensor probe 301 and affecting the detection accuracy, the surface of the guide groove 1 is covered with the first coating, the second coating and the third coating, which can realize dust filtration and waterproof at the physical level, dust decomposition at the chemical level, and dual dust prevention of physics and chemistry, reduce the influence of air humidity and dust concentration on the detection result of the sensor probe 301, and improve the measurement accuracy and stability of the fiber grating wind speed sensor.

[0050] In an implementation manner, the first coating is a multi-gradient porous coating including an outer layer, a middle layer and an inner layer. Coarse particle dust, medium particle dust and fine particle dust can be filtered in stages, the clogging speed is slowed down, and the service life of the coating is prolonged. Among them, the outer layer, the middle layer and the inner layer respectively realize filtering of dust particles of different gradients.

[0051] For example, the pore size of the outer layer of the first coating is 10 um, which is used for filtering coarse particle dust; the pore size of the middle layer is 5 um, which is used for filtering medium particle dust; and the pore size of the inner layer is 1 um, which is used for filtering fine particle dust.

[0052] In some embodiments, in order to ensure the passability of the airflow, reduce the probability of dust adhering to the surface of the sensor probe 301, and improve the performance of the fiber grating wind speed sensor, the first coating is designed to have a porosity greater than 40%.

[0053] For example, the average porosity of the outer layer, the middle layer and the inner layer of the first coating is 45%. It should be understood that the average porosity of the first coating can also be designed to other values, which are not limited in the embodiments of the present application.

[0054] In some embodiments, to improve the overall protective performance of the sensor probe 301 and enhance its anti-interference capability in environments with high humidity and dust concentration in mines, thereby improving the accuracy and stability of wind speed detection, three coatings of different materials with different protective functions are applied from the outside to the inside to the surface of the guide groove 1 of the sensor probe 301. The first coating is a porous ceramic coating; the second coating is a hydrophobic material coating; and the third coating is a nano-coating with thermal conductivity.

[0055] For example, the first coating is porous aluminum oxide (Alumina). The first coating is a ceramic coating; the second coating is a fluorosilane coating; the third coating is titanium dioxide. ) Graphene nanocoating. Among them, porous The ceramic coating is 100nm thick to prevent wear on the flow channel 1 and extend its service life; the fluorosilane coating has a contact angle with water greater than 150° and has superhydrophobic properties, which can play a waterproof role. The graphene nanocoating has thermal conductivity and can decompose organic dust under photocatalysis, reducing the influence of air humidity and dust concentration on the sensor probe 301, and improving the detection accuracy and stability of the fiber Bragg grating wind speed sensor.

[0056] This application also provides a fiber optic grating wind speed sensor.

[0057] Figure 3 This is a schematic diagram of a fiber Bragg grating wind speed sensor structure provided in an embodiment of this application. Figure 3 As shown, the fiber optic wind speed sensor includes the sensor probe 301 provided in the above embodiment and the fiber optic grating; the fiber optic grating is disposed inside the flow guide groove 1 of the sensor probe 301.

[0058] In one implementation, the fiber Bragg grating is placed in the sensor probe 301, which has the functions of isolating dust and waterproofing. This can reduce the impact of dust and water vapor in the external environment on the measurement accuracy of the fiber Bragg grating, thereby improving the detection accuracy and stability of the fiber Bragg grating wind speed sensor.

[0059] In some embodiments, the fiber Bragg grating wind speed sensor further includes: a pump source 302, an optical cable 303, and a fiber Bragg grating demodulator 304; the top end 201 of the sensor probe 301 is connected to the pump source, and the bottom end 202 of the sensor probe 301 is connected to the optical cable; the fiber Bragg grating is connected to the fiber Bragg grating demodulator.

[0060] For example, the top end 201 of the sensor probe 301 is connected to a pump source, which emits laser light to irradiate the optical fiber grating and heat the hot wire, so that the heat of the optical fiber grating wind speed sensor reaches equilibrium. When there is wind flowing in the environment, the heat of the sensor probe 301 surface is dissipated, the wavelength of the optical fiber grating is shifted, the wavelength shift is detected by the optical fiber grating demodulator connected to the optical fiber grating, and then the temperature change is detected, and the wind speed is calculated according to the temperature change.

[0061] Figure 2 is a flow chart of a method for detecting wind speed by the optical fiber grating wind speed sensor provided in the embodiments of the present application.

[0062] In some embodiments, the optical fiber grating wind speed sensor is based on a fiber Bragg grating, and uses the solution of the heat convection equation to detect the wind speed. Figure 2 As shown, the steps of detecting the wind speed by the optical fiber grating wind speed sensor include S1-S3.

[0063] S1: heating to an equilibrium temperature.

[0064] In some embodiments, the optical fiber in the optical fiber grating wind speed sensor is a silver-doped optical fiber, and a speed measurement grating and a temperature grating are simultaneously engraved on the silver-doped optical fiber. The optical fiber grating is connected to a laser pump source and an optical fiber grating demodulator.

[0065] First, the pump source emits laser light to heat the hot wire in the optical fiber grating temperature sensor to an equilibrium temperature .

[0066] S2: calculating a temperature difference.

[0067] When there is wind flowing through the optical fiber grating temperature sensor, the heat of the hot wire in the optical fiber grating temperature sensor is taken away, resulting in a temperature drop to , and the temperature difference is calculated .

[0068] S3: calculating the wind speed according to the temperature difference.

[0069] Based on King’s Law, the relationship between the heat dissipation of the hot wire in the optical fiber grating temperature sensor and the flow rate is shown in formula (1):

[0070] , (1)

[0071] wherein is the heating power, is the current, is the hot wire resistance, is the fluid velocity, and are the hot wire temperature and the fluid temperature, respectively, and is a constant related to fluid properties and probe geometry.

[0072] According to the heat balance law, in the case of ventilation, the heat consumed by the fiber grating wind speed sensor is the same as the heat absorbed, so formula (1) is written as formula (2):

[0073] , (2)

[0074] wherein, is the power of the pump source, is the correlation coefficient of the pump source, is the absorption coefficient of silver.

[0075] Therefore, the relationship between the wavelength shift of the fiber Bragg grating and the temperature difference is shown in formula (3):

[0076] , (3)

[0077] wherein, is the Bragg wavelength shift, is the thermo-optic coefficient of the fiber Bragg grating.

[0078] In some embodiments, by using formula (3), the Bragg wavelength shift is calculated by the temperature difference , and then the hot-wire temperature change of the fiber grating wind speed sensor is obtained by the fiber grating demodulator, and the wind speed value is calculated according to the King's law, so as to realize the wind speed detection.

[0079] From the above technical solution, the application provides a sensor probe 301 and a fiber grating wind speed sensor. The sensor probe 301 comprises: a flow guide groove 1; the flow guide groove 1 is a single-rotation-direction asymmetric spiral structure; the surface of the flow guide groove 1 is sequentially covered with a first coating, a second coating and a third coating from outside to inside; the first coating is a multi-gradient coating for grading dust filtration, the second coating is used for waterproofing, and the third coating is used for dust decomposition.

[0080] The sensor probe 301 described above adopts the flow guide groove 1 with a single-rotation-direction asymmetric spiral structure, which can use the centrifugal force generated by the asymmetric spiral structure to throw dust particles to the outer edge of the channel and maintain air flow passability. The surface of the flow guide groove 1 is covered with three coatings, which can realize dust filtration and waterproofing at the physical level, and dust decomposition at the chemical level, achieving double dust prevention of physics and chemistry, reducing the influence of air humidity and dust concentration on the detection results of the sensor probe 301, and improving the measurement accuracy and stability of the fiber grating wind speed sensor.

[0081] The similar parts among the embodiments provided in the application can be referred to each other, the specific embodiments provided above are only several examples under the general concept of the application, and do not constitute the limitation of the protection scope of the application. Any other embodiments extended according to the application scheme without creative labor for those skilled in the art shall fall within the protection scope of the application.

Claims

1. A fiber optic Bragg grating wind speed sensor, characterized by, The sensor probe (301) and the fiber grating are included. The fiber grating is arranged inside the flow guide groove (1) of the sensor probe (301). The sensor probe (301) includes a flow guide groove (1). The flow guide groove (1) is a single-helical asymmetric spiral structure, so that the airflow flows along a spiral path and forms an asymmetric pressure distribution and flow direction. The pitch of the flow guide groove (1) gradually decreases from the inlet (101) to the outlet (102), the pitch of the flow guide groove (1) at the inlet (101) is 10mm, and the pitch of the flow guide groove (1) at the outlet (102) is 5mm. The groove depth of the flow guide groove (1) gradually increases from the inlet (101) to the outlet (102), the groove depth of the flow guide groove (1) at the inlet (101) is 0.5mm, and the groove depth of the flow guide groove (1) at the outlet (102) is 1.5mm. The width of the flow guide groove (1) gradually decreases from the outside to the inside, the width of the flow guide groove (1) on the outside is 1.2mm, and the width of the flow guide groove (1) on the inside is 0.8mm. The angle between the groove of the flow guide groove (1) and the axis gradually increases from the inlet (101) to the outlet (102), the angle between the groove of the flow guide groove (1) and the axis at the inlet (101) is 15°, and the angle between the groove of the flow guide groove (1) and the axis at the outlet (102) is 45°. The surface of the flow guide groove (1) is sequentially covered with a first coating, a second coating and a third coating from the outside to the inside; the first coating is a multi-gradient coating for filtering dust in stages, the second coating is a hydrophobic material coating for waterproofing, and the third coating is a nano coating with heat conduction performance for decomposing dust under photocatalysis; the thickness of the first coating is 100nm; the contact angle between the second coating and water is greater than 150°. The first coating is a porous ceramic coating including an outer layer, a middle layer and an inner layer; the outer layer has a pore size of 10um for filtering coarse particle dust; the middle layer has a pore size of 5um for filtering medium particle dust; and the inner layer has a pore size of 1um for filtering fine particle dust. The fiber grating wind speed sensor further includes a pump source (302), an optical cable (303) and a fiber grating demodulator (304). The top end (201) of the sensor probe (301) is connected to the pump source (302), and the bottom end (202) of the sensor probe (301) is connected to the optical cable (303). The fiber grating is connected to the fiber grating demodulator (304). The pump source (302) emits laser light to heat the fiber grating to an equilibrium temperature. After the airflow passes through the fiber grating, the current temperature of the fiber grating is detected, and the temperature difference is calculated according to the current temperature and the equilibrium temperature. The wind speed is calculated according to the temperature difference.

2. The fiber grating wind speed sensor according to claim 1, wherein the porosity of the first coating is greater than 40%.

3. The fiber grating wind speed sensor according to claim 1, wherein the first coating is a porous aluminum oxide ceramic coating. ​ ​ ​ The second coating is a fluorosilane coating; The third coating is a titanium dioxide graphene nano coating.

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