An ultra-thin array area temperature sensor

Abstract

An embodiment of the present specification provides an ultra-thin array-type regional temperature sensor, comprising: an FBG sensor, an optical fiber, a glass fiber woven prepreg, and a polyimide film, wherein the FBG sensor and the optical fiber are laid on a first polyimide film, and the upper layer of the FBG sensor and the optical fiber is covered with a second polyimide film, a first glass fiber woven prepreg is provided under the first polyimide film, and a second glass fiber woven prepreg is covered on the second polyimide film, and the first glass fiber woven prepreg and the second glass fiber woven prepreg are used to encapsulate the FBG sensor to monitor the temperature field of a planar area and improve the accuracy of planar area temperature monitoring.

Description

Technical Field

[0001] This document relates to the field of optical fiber sensing technology, and in particular to an ultra-thin array type area temperature sensor. Background Art

[0002] Wind power is a clean and renewable energy source. Wind power technology is maturing and is undergoing large-scale development and application. However, wind power systems still face many challenges, one of which is blade icing, which poses the greatest threat. In China, a large number of wind farms are located in northern China or in the mountainous areas of central and southern China, making them vulnerable to ice and snow. Winters in northern my country are dry and cold, with large temperature swings between day and night. From November to February, temperatures in most areas drop below zero, reaching as low as -30°C in the northeast. Cold fronts often bring heavy rain and snow. Although southern China has a warm climate and winter temperatures often remain around zero degrees Celsius, high humidity and abundant winter precipitation also lead to ice accumulation. Ice accumulation increases the load on blades, making them more susceptible to breakage. Even if these blades don't break, the ice often alters the blade's shape, affecting aerodynamic performance and reducing generator efficiency. Modern wind turbines are equipped with ice protection systems, consisting of ice detection and de-icing systems. In the prior art, the anti-icing system is mainly composed of a main control unit, a heating unit, and a monitoring unit. The heating unit and the monitoring unit are used in conjunction with the main control unit to monitor ice formation and remove ice. Traditional monitoring units use a single FBG sensor or a distributed optical fiber sensor to monitor temperature. They can only monitor the temperature at a certain point and cannot know the temperature of a planar area. The distributed optical fiber sensor temperature measurement method used in existing wind turbine blades often regards the temperature on a certain distance of optical fiber as the temperature of a point due to the limitation of its spatial resolution, and cannot monitor the temperature field of a planar area. Therefore, it is necessary to design an array-type regional temperature sensor to monitor the temperature field of a planar area and improve the accuracy of temperature monitoring. Summary of the Invention

[0003] One or more embodiments of the present specification provide an ultra-thin array-type regional temperature sensor, comprising: a plurality of FBG sensors, optical fibers, glass fiber braided prepregs, and polyimide films, wherein the FBG sensors and the optical fibers are laid on a first polyimide film, a first glass fiber braided prepreg is provided under the first polyimide film, the FBG sensors and the optical fibers are covered with a second polyimide film, and the second polyimide film is covered with a second glass fiber braided prepreg.

[0004] Furthermore, the FBG sensor outer shell is provided with a PI sleeve.

[0005] Furthermore, the FBG sensor is arranged at the center of the PI sleeve, the length of the FBG sensor is 15 mm, and the length of the PI sleeve is 26 mm.

[0006] Furthermore, the first polyimide film is 15 mm away from both left and right boundaries of the glass fiber woven prepreg, and 15 mm away from the upper boundary of the first glass fiber woven prepreg.

[0007] Furthermore, the distance between the second polyimide film and the left and right boundaries of the glass fiber woven prepreg is 10 mm, and the distance between the second polyimide film and the upper boundary of the second glass fiber woven prepreg is 10 mm.

[0008] Furthermore, the first polyimide film and the second polyimide film are each divided into two symmetrical parts, and the axis of symmetry is parallel to the upper and lower boundaries of the glass fiber woven prepreg.

[0009] Furthermore, the optical fiber is arranged in a wave shape along the symmetry axis, including a plurality of crests and troughs.

[0010] Furthermore, the FBG sensors are arranged at the crests and troughs of the laid optical fiber, and the interval between the FBG sensors arranged at adjacent crests and troughs is 160 mm.

[0011] Furthermore, the FBG sensors arranged at the crest and trough are 20 mm away from the upper and lower boundaries of the glass fiber woven prepreg, and a straight optical fiber with a length of 20 mm is provided at both the left and right ends of the optical fiber.

[0012] Furthermore, the glass fiber woven prepreg has a length of 1026 mm and a width of 200 mm.

[0013] By adopting the embodiment of the present invention, a polyimide film layer is embedded in the glass fiber woven prepreg so that the FBG sensor can move relatively in the glass fiber woven prepreg, thereby preventing the array-type regional temperature sensor from being deformed by external forces during the temperature monitoring process and causing stress interference to the FBG sensor; the polyimide film layer is designed to be large and small, thereby preventing the resin in the glass fiber woven prepreg from entering the unsealed end of the PI sleeve during the packaging process of the array-type regional temperature sensor and affecting the FBG sensor; the temperature field of the planar area can be monitored, thereby improving the accuracy of the planar area temperature monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 This is a schematic structural diagram of an ultra-thin array-type regional temperature sensor according to an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of laying optical fibers and FBG sensors in an array-type area temperature sensor according to an embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of the locations of several FBG sensor monitoring points inside an array-type regional temperature sensor according to an embodiment of the present invention;

[0018] Figure 4 A schematic diagram of a plane area divided by a Delaunay triangle mesh of an array-type area temperature sensor according to an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of constructing Thiessen polygons for an array-type regional temperature sensor according to an embodiment of the present invention;

[0020] Figure 6 A schematic diagram of Thiessen polygon area division for an array-type area temperature sensor according to an embodiment of the present invention.

[0021] Reference numerals:

[0022] 1: FBG sensor; 2: optical fiber; 3: glass fiber braided prepreg; 4: polyimide film; 31: first glass fiber braided prepreg; 32: second glass fiber braided prepreg; 41: first polyimide film; 42: second polyimide film. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the technical solutions in one or more embodiments of this specification will be clearly and completely described below in conjunction with the drawings in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this document.

[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a communication between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] Device embodiment

[0027] According to an embodiment of the present invention, an ultra-thin array type regional temperature sensor is provided. Figure 1 FIG. 1 is a schematic structural diagram of an ultra-thin array type regional temperature sensor according to an embodiment of the present invention. Figure 1 As shown, the ultra-thin array-type area temperature sensor includes: multiple FBG sensors 1, optical fibers 2, glass fiber braided prepreg 3, and polyimide film 4. The glass fiber braided prepreg includes a first glass fiber braided prepreg 31 and a second glass fiber braided prepreg 32, and the polyimide film includes a first polyimide film 41 and a second polyimide film 42. According to the ultra-thin array-type area temperature sensor of this embodiment of the present invention, the FBG sensors 1 and optical fibers 2 are laid on the first polyimide film 41, and the second polyimide film 42 is covered on the FBG sensors 1 and optical fibers 2. The first glass fiber braided prepreg 31 is provided below the first polyimide film 41, and the second glass fiber braided prepreg 32 is covered on the second polyimide film 42. The first glass fiber braided prepreg 31 and the second glass fiber braided prepreg 32 encapsulate the FBG sensors 1.

[0028] The first glass fiber woven prepreg 31 and the second glass fiber woven prepreg 32 have the same size, with a length of 1026 mm and a width of 200 mm.

[0029] The first polyimide film 41 is 996 mm long, with its left and right edges each 15 mm away from the left and right edges of the first woven glass fiber prepreg 31. The first polyimide film 41 is 67 mm wide, with its upper edge 15 mm away from the upper edge of the first woven glass fiber prepreg 31. The second polyimide film 42 is 1006 mm long, with its left and right edges each 10 mm away from the left and right edges of the second woven glass fiber prepreg 32. The second polyimide film 42 is 77 mm wide, with its upper edge 10 mm away from the upper edge of the second woven glass fiber prepreg 32. Both the first polyimide film 41 and the second polyimide film 42 are two equal-sized films, symmetrically arranged on their corresponding woven glass fiber prepregs along an axis of symmetry, separated by 26 mm. The axis of symmetry is parallel to the upper and lower edges of the woven glass fiber prepregs.

[0030] Figure 2 FIG. 1 is a schematic diagram of laying optical fibers and FBG sensors in an array-type regional temperature sensor according to an embodiment of the present invention. Figure 2 As shown, the optical fiber is arranged in a wavy pattern along the axis of symmetry, including several peaks and troughs. Between two equal-sized films, the optical fiber is arranged as a straight segment perpendicular to the axis of symmetry, with a length of 26 mm. The radius of the arc segment at the peaks and troughs is 67 mm. FBG sensors are placed at the peaks and troughs of the laid optical fiber, with the horizontal and horizontal spacing between FBG sensors located at adjacent peaks and troughs being 160 mm.

[0031] The FBG sensor is covered with a PI sleeve, sealed on one end with glue, to protect the internal FBG sensor and prevent it from shrinking at low temperatures and interfering with its temperature measurement accuracy. The FBG sensor is placed in the center of the PI sleeve. The FBG sensor is 15mm long, and the PI sleeve is 26mm long.

[0032] The distance between the FBG sensor set at the crest and the upper boundary of the glass fiber woven prepreg is 20 mm, and the distance between the FBG sensor set at the trough and the lower boundary of the glass fiber woven prepreg is 20 mm. A 20 mm long straight optical fiber is provided at both ends of the optical fiber for connecting to a demodulation device or other array temperature sensor.

[0033] Based on the Thiessen polygon algorithm, the algorithm flow for calculating the temperature of the plane area to be measured using the above array area temperature sensor is as follows:

[0034] Construct a Delaunay triangle mesh: Figure 3This is a schematic diagram of the locations of several FBG sensor monitoring points inside the array-type regional temperature sensor according to an embodiment of the present invention. The plane area is divided into Delaunay triangle meshes according to the locations of each monitoring point (E~K). The division results are shown in FIG. Figure 4 shown.

[0035] Construct Thiessen polygons: Draw the perpendicular bisectors of the sides of each Delaunay triangle. The polygons formed by the perpendicular bisectors are Thiessen polygons, such as Figure 5 shown.

[0036] Calculation of average temperature of plane area: Figure 6 As shown, let the plane area be A, and the temperature (T i , i=1,2,3,4,5,6,7) as the temperature of the Thiessen polygon area, and the area of each Thiessen polygon (S i ,i=E,F,G,H,I,J,K) relative to the total area of the plane area (S A ) is the area ratio of the weight (l i , i=1,2,3,4,5,6,7), the average temperature T of plane area A is calculated by formula 1 A :

[0037]

[0038] By adopting the embodiment of the present invention, a polyimide film layer is embedded in the glass fiber woven prepreg so that the FBG sensor can move relatively in the glass fiber woven prepreg, thereby preventing the array-type regional temperature sensor from being deformed by external forces during the temperature monitoring process and causing stress interference to the FBG sensor; the polyimide film layer is designed to be large and small, thereby preventing the resin in the glass fiber woven prepreg from entering the unsealed end of the PI sleeve during the packaging process of the array-type regional temperature sensor and affecting the FBG sensor; the temperature field of the planar area can be monitored, thereby improving the accuracy of the planar area temperature monitoring.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultra-thin array type area temperature sensor, characterized in that: include: An FBG sensor, an optical fiber, a glass fiber braided prepreg, and a polyimide film, wherein the FBG sensor and the optical fiber are laid on a first polyimide film, the upper layer of the FBG sensor and the optical fiber is covered with a second polyimide film, a first glass fiber braided prepreg is provided under the first polyimide film, and a second glass fiber braided prepreg is covered on the second polyimide film, and the first glass fiber braided prepreg and the second glass fiber braided prepreg are used to encapsulate the FBG sensor; The distance between the first polyimide film and the left and right boundaries of the glass fiber woven prepreg is 15 mm, and the distance between the first polyimide film and the upper boundary of the first glass fiber woven prepreg is 15 mm; the distance between the second polyimide film and the left and right boundaries of the glass fiber woven prepreg is 10 mm, and the distance between the second polyimide film and the upper boundary of the second glass fiber woven prepreg is 10 mm.

2. The sensor according to claim 1, characterized in that There are a plurality of FBG sensors, and the outer shells of the FBG sensors are provided with PI sleeves.

3. The sensor according to claim 2, characterized in that The FBG sensor is arranged at the center of the PI sleeve. The length of the FBG sensor is 15 mm, and the length of the PI sleeve is 26 mm.

4. The sensor according to claim 1, wherein The first polyimide film and the second polyimide film are both divided into two symmetrical parts, and the symmetry axis is parallel to the upper and lower boundaries of the glass fiber woven prepreg.

5. The sensor according to claim 4, characterized in that The optical fiber is arranged in a wave shape along the symmetry axis, including a plurality of wave crests and wave troughs.

6. The sensor according to claim 5, characterized in that The FBG sensors are arranged at the crests and troughs of the laid optical fiber, and the interval between the FBG sensors arranged at adjacent crests and troughs is 160 mm.

7. The sensor according to claim 5, characterized in that The FBG sensors arranged at the crest and trough are 20 mm away from the upper and lower boundaries of the glass fiber woven prepreg respectively, and a 20 mm long straight optical fiber is provided at both the left and right ends of the optical fiber.

8. The sensor according to claim 1, wherein The length and width of the first glass fiber woven prepreg and the second glass fiber woven prepreg are 1026 mm and 200 mm, respectively.

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