Fiber bragg grating demodulator

Abstract

The invention discloses a fiber bragg grating demodulator, and relates to the technical field of fiber bragg grating detection, the fiber bragg grating demodulator comprises a foaming cement bearing body, the foaming cement bearing body is internally provided with a bearing cavity and a constant temperature cavity, and one side of the bearing cavity and one side of the constant temperature cavity are communicated with the outside; a sealing mechanism used for isolating the bearing cavity from the outside is arranged at an opening of the bearing cavity, hardware equipment, a temperature detection assembly and a temperature adjusting assembly are arranged in the bearing cavity, a constant temperature assembly is arranged in the constant temperature cavity, and a power supply assembly is arranged on the foaming cement bearing body. When the device is used, the temperature in the bearing cavity is adjusted through the cooling mechanism and the heating mechanism, and due to the fact that the inner space of the bearing cavity is small, and foaming cement has the low heat conductivity coefficient and the high heat resistance, the temperature can be conveniently recovered to be normal in time. Meanwhile, the liquid in the constant-temperature water tank can play a role in temperature buffering, so that the monitoring effect is prevented from being influenced by too fast temperature change of the foamed cement bearing body.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber grating detection, and particularly relates to a fiber grating demodulator. Background Art

[0002] Fiber grating detection utilizes the photosensitivity of fiber materials to form a permanent spatial phase grating in the core through ultraviolet light exposure. When broadband light passes through, the wavelength that satisfies the fiber grating Bragg condition will be reflected, and the remaining wavelengths will continue to transmit. Utilizing this characteristic, the fiber grating can be used as a sensitive element to convert external forces into changes in the optical wavelength, thereby achieving high-precision measurement of various parameters such as the stress and temperature of the detected object through a fiber grating demodulator.

[0003] In high-speed bridge sections, in order to reduce signal attenuation and the impact on the performance of the fiber grating demodulator, the device is usually installed in the bridge monitoring computer room or at a suitable position such as the bottom beam in the middle of the bridge that is shielded from light and rain. Such installation options aim to ensure that the fiber grating demodulator can operate in a stable and good environment, thereby accurately and reliably receiving and demodulating the signals from the fiber grating sensors at key structural parts of the bridge.

[0004] When the fiber grating demodulator is in use, temperature fluctuations may cause the laser wavelength scanning step to deviate from the preset value, thereby causing a demodulation error in the grating reflection wavelength. At the same time, temperature changes will also cause thermal deformation of the internal optical components (such as fiber couplers and beam splitters) of the demodulator, resulting in a shift in the baseline wavelength. In order to maintain the measurement accuracy, the demodulator needs to be calibrated frequently (which can be automatically completed), affecting the accuracy of detection. However, in some areas with large temperature differences between day and night, such as some regions in Xinjiang, Gansu, and Inner Mongolia, this temperature change has an adverse impact on maintaining the performance of the fiber grating demodulator, increasing the complexity and frequency of calibration, thereby affecting its overall performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a fiber grating demodulator, which solves the technical problem that in some areas with large temperature differences between day and night, it has an adverse impact on maintaining the performance of the fiber grating demodulator.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A fiber grating demodulator includes a foamed cement carrier. A bearing cavity and a constant temperature cavity are provided inside the foamed cement carrier. One side of the bearing cavity and the constant temperature cavity is connected to the outside. A sealing mechanism for isolating the bearing cavity from the outside is provided at the opening of the bearing cavity. Hardware devices, a temperature detection component, and a temperature regulation component are arranged inside the bearing cavity. A constant temperature component is arranged inside the constant temperature cavity. A power supply component is arranged on the foamed cement carrier.

[0008] As a further solution of the present invention: The constant temperature component includes a constant temperature water tank arranged inside the constant temperature cavity. A liquid injection port is arranged on one side of the constant temperature water tank close to the opening of the constant temperature cavity, and a rotary cover is cooperatively arranged on the liquid injection port.

[0009] As a further solution of the present invention: The temperature regulation component includes a cooling mechanism. The cooling mechanism includes a liquid bag, a liquid pump, and a heat conduction water pipe. The liquid bag is cooperatively connected with the liquid pump. One end of the heat conduction water pipe is cooperatively connected with the liquid pump, and the other end of the heat conduction water pipe is cooperatively connected with the liquid bag. The liquid bag is located inside the constant temperature water tank.

[0010] As a further solution of the present invention: The temperature regulation component further includes a heating mechanism. The heating mechanism includes a heating wire fixedly arranged inside the bearing cavity, and a protective cage is arranged around the side of the heating wire.

[0011] As a further solution of the present invention: The heat conduction water pipe includes a first side cooling water pipe, a rear cooling water pipe, and a second side cooling water pipe. The first side cooling water pipe, the rear cooling water pipe, and the second side cooling water pipe all extend longitudinally in a reciprocating manner and are distributed on the inner wall of the bearing cavity. The first side cooling water pipe and the second side cooling water pipe are respectively located on both sides of the bearing cavity, and the rear cooling water pipe is located at the rear side of the bearing cavity. One end of the first side cooling water pipe is communicated with the output end of the liquid pump, and the other end is communicated with the input end of the rear cooling water pipe. The other end of the rear cooling water pipe is communicated with the second side cooling water pipe, and the other end of the second side cooling water pipe is communicated with the liquid bag.

[0012] As a further solution of the present invention: An insertion port communicated with the front side of the bearing cavity is opened above the foamed cement carrier. The closing mechanism includes a plug board slidably matched with the insertion port, and a positioning component for positioning the plug board is arranged on the front side of the foamed cement carrier.

[0013] As a further solution of the present invention: A locking port matched with the insertion port is opened on the front side of the foamed cement carrier. A slot is opened on the plug board. The positioning component includes a locking board slidably matched with the locking port and used for inserting into the slot. A protruding board is arranged below the locking port, and locking holes convenient for inserting a lock ring are opened on both the locking board and the protruding board.

[0014] As a further solution of the present invention: A ventilation component is arranged on the rotary cover.

[0015] As a further solution of the present invention: The power supply component includes a photovoltaic panel, and the photovoltaic panel is fixedly arranged on both sides of the foamed cement carrier.

[0016] As a further solution of the present invention: Slopes are arranged on both sides of the foamed cement carrier, and each group of photovoltaic panels is located on the corresponding slope.

[0017] Advantages of the present invention:

[0018] 1. When in use, when the temperature inside the bearing cavity is too low, the heating mechanism is started, and the heating wire inside the heating mechanism generates heat to realize the heating operation of the bearing cavity. When the temperature inside the bearing cavity is too high, the liquid pump is started to make the coolant inside the liquid bag start to circulate. The coolant sequentially enters the liquid bag, the liquid pump, the first side cooling water pipe, the rear cooling water pipe, the second side cooling water pipe, and the liquid bag, so as to timely reduce the temperature inside the bearing cavity and reduce the impact of high temperature on the hardware equipment. Since the space inside the bearing cavity is small and the foamed cement has a low thermal conductivity and a high thermal resistance, the heat transfer is effectively reduced, and then it is convenient to timely restore the temperature to normal and reduce the impact of high and low temperatures on the hardware equipment.

[0019] 2. When in use, a constant temperature water tank is arranged inside the foamed cement carrier, and a liquid with a high specific heat capacity is filled inside the constant temperature water tank. When the temperature difference between day and night is large, the liquid inside the constant temperature water tank can play a role in temperature buffering, avoiding too fast temperature change of the foamed cement carrier, causing deformation of the optical path (such as fiber optic coupler, optical splitter) inside the demodulator, resulting in baseline wavelength shift, and frequent calibration is required to maintain the accuracy. A ventilation component is arranged on the screw cap to reduce the impact of liquid thermal expansion and contraction on the constant temperature water tank.

[0020] 3. When in use, the internal environment of the cement column is relatively closed, which can effectively isolate external corrosive media such as acids, alkalis, salt mists, and humidity, extend the service life of the fiber Bragg grating sensor, and reduce the frequency and cost of manual inspection. At the same time, the fiber Bragg grating sensor itself is resistant to electromagnetic interference, and cement, as a non-conductive material, further enhances the electromagnetic shielding effect to ensure the detection effect of the fiber optic grating demodulator.

[0021] 4. When in use, photovoltaic panels are arranged on both sides of the foamed cement carrier, and photovoltaic power generation is realized through the photovoltaic panels, and then power is supplied to the heating wire, the temperature detection component or the liquid pump to reduce the transmission of electric energy through the main cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present invention will be further described below with reference to the accompanying drawings.

[0023] Figure 1 is the overall structural schematic diagram of the present invention;

[0024] Figure 2 is the overall longitudinal sectional structural schematic diagram of the present invention;

[0025] Figure 3 is the overall front view structural schematic diagram of the present invention;

[0026] Figure 4 is the structural schematic diagram of the constant temperature component of the present invention;

[0027] Figure 5 It is a schematic structural diagram of the temperature reduction mechanism of the present invention.

[0028] In the figure: 1, foamed cement carrier; 101, bearing cavity; 102, constant temperature cavity; 103, locking port; 104, socket; 2, photovoltaic panel; 3, temperature reduction mechanism; 301, liquid bag; 302, liquid pump; 303, heat conduction water pipe; 3031, first side temperature reduction water pipe; 3032, rear temperature reduction water pipe; 3033, second side temperature reduction water pipe; 4, temperature increase mechanism; 5, sealing mechanism; 501, insertion plate; 502, slot; 503, locking plate; 6, constant temperature component; 601, constant temperature water tank; 602, liquid injection port; 603, screw cap; 7, hardware device. Specific embodiments

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] Please refer to Figures 1-5 As shown, the present invention is an optical fiber grating demodulator, including a foamed cement carrier 1, as Figure 2 shown, a bearing cavity 101 and a constant temperature cavity 102 are opened inside the foamed cement carrier 1. Both the bearing cavity 101 and the constant temperature cavity 102 are connected to the outside on one side. A hardware device 7 is arranged inside the bearing cavity 101, and the hardware device 7 includes a photoelectric conversion circuit, an analog-to-digital conversion circuit, a main controller, and a filter circuit module. A sealing mechanism 5 for isolating the bearing cavity 101 from the outside is arranged at the opening of the bearing cavity 101. A socket 104 communicating with the front side of the bearing cavity 101 is opened above the foamed cement carrier 1. The sealing mechanism 5 includes an insertion plate 501 slidably matched with the socket 104. A positioning component for positioning the insertion plate 501 is arranged on the front side of the foamed cement carrier 1. A locking port 103 matched with the socket 104 is opened on the front side of the foamed cement carrier 1. A slot 502 is opened on the insertion plate 501, as Figure 2As described above, there are two sets of slots 502, which are respectively located at the upper and lower ends of the plug board 501. The positioning component includes a locking plate 503 that is slidably engaged with the locking opening 103 and is used to insert into the slot 502. There is a protruding plate below the locking opening 103, and locking holes for facilitating the insertion of the locking ring are provided on both the locking plate 503 and the protruding plate, thereby realizing the positioning of the locking plate 503. When it is necessary to open the bearing cavity 101, the locking plate 503 can be withdrawn from the locking opening 103, so that the locking plate 503 is away from the slot 502 at the upper end of the plug board 501. Lift the plug board 501 to align the slot 502 at the lower end of the plug board 501 with the locking opening 103, and push the locking plate 503 so that the locking plate 503 is inserted into the slot 502 at the lower end of the plug board 501. Fix the plug board 501 through the locking plate 503, so that the bearing cavity 101 is connected to the outside, facilitating the staff to maintain the internal hardware device 7 in the bearing cavity 101.

[0031] A temperature control component 6 is arranged inside the constant temperature cavity 102. The temperature control component 6 includes a constant temperature water tank 601 arranged inside the constant temperature cavity 102. A liquid injection port 602 is arranged on the constant temperature water tank 601 near the opening of the constant temperature cavity 102. A rotary cover 603 is arranged in cooperation with the liquid injection port 602. A liquid with a relatively large specific heat capacity (this liquid can be water) can be injected into the constant temperature water tank 601 through the liquid injection port 602. An air exchange component is arranged on the rotary cover 603. The air exchange component is a set of air filtration equipment, which is used to reduce the influence caused by thermal expansion and contraction on the constant temperature water tank 601.

[0032] A temperature adjustment component is also arranged inside the bearing cavity 101. The temperature adjustment component includes a cooling mechanism 3, such as Figure 5 As shown, the cooling mechanism 3 includes a liquid bag 301, a liquid pump 302 and a heat conduction water pipe 303. The output end of the liquid bag 301 is connected to the input end of the liquid pump 302 in cooperation. The input end of the heat conduction water pipe 303 is connected to the output end of the liquid pump 302 in cooperation. The other end of the heat conduction water pipe 303 is connected to the input end of the liquid bag 301 in cooperation. The liquid bag 301 is located inside the constant temperature water tank 601, and the temperature of the liquid bag 301 is maintained by the constant temperature water tank 601. The heat conduction water pipe 303 includes a first side cooling water pipe 3031, a rear cooling water pipe 3032 and a second side cooling water pipe 3033, such as Figure 4As shown in the figure, the first-side cooling water pipe 3031, the rear cooling water pipe 3032, and the second-side cooling water pipe 3033 all extend longitudinally in a reciprocating manner and are distributed on the inner wall of the bearing cavity 101. The first-side cooling water pipe 3031 and the second-side cooling water pipe 3033 are respectively located on both sides of the bearing cavity 101, and the rear cooling water pipe 3032 is located at the rear side of the bearing cavity 101. One end of the first-side cooling water pipe 3031 is communicated with the output end of the liquid pump 302, and the other end is communicated with the input end of the rear cooling water pipe 3032. The other end of the rear cooling water pipe 3032 is communicated with the second-side cooling water pipe 3033, and the other end of the second-side cooling water pipe 3033 is communicated with the liquid bag 301. A temperature detection component is arranged inside the bearing cavity 101 to detect the temperature inside the bearing cavity 101. When the detected temperature is too high, the liquid pump 302 is started to make the coolant inside the liquid bag 301 start to circulate. The coolant sequentially enters the liquid bag 301, the liquid pump 302, the first-side cooling water pipe 3031, the rear cooling water pipe 3032, the second-side cooling water pipe 3033, and the liquid bag 301, so as to timely reduce the temperature inside the bearing cavity 101 and reduce the influence of high temperature on the hardware device 7.

[0033] The temperature control component further includes a heating mechanism 4. The heating mechanism 4 includes a heating wire fixedly arranged inside the bearing cavity 101, and a protective cage is arranged around the side of the heating wire. When it is detected that the temperature inside the bearing cavity 101 is too low, the heating wire is heated to make the temperature inside the bearing cavity 101 rise. Since the internal space of the bearing cavity 101 is small, it is convenient to timely restore the temperature and reduce the influence of low temperature on the hardware device 7.

[0034] As Figure 1 shown in the figure, a power supply component is arranged on the foamed cement carrier 1. The power supply component includes a photovoltaic panel 2. The photovoltaic panel 2 is fixedly arranged on both sides of the foamed cement carrier 1. There are slopes on both sides of the foamed cement carrier 1, and each group of photovoltaic panels 2 is located on the corresponding slope. The hardware device 7 further includes a power storage device. Photovoltaic power generation is realized through the photovoltaic panel 2, and the electric energy is stored through the power storage device, and then the heating wire, the temperature detection component or the liquid pump 302 is powered to reduce the transmission of electric energy by the main cable. The internal environment of the cement column is relatively closed, which can effectively isolate external corrosive media such as acids, alkalis, salt mists, and humidity, extend the service life of the fiber Bragg grating sensor, and reduce the frequency and cost of manual inspection. At the same time, the fiber Bragg grating sensor itself is resistant to electromagnetic interference, and the cement, as a non-conductive material, further enhances the electromagnetic shielding effect and ensures the detection effect of the fiber Bragg grating demodulator.

[0035] Working principle of the present invention: During use, when the temperature inside the bearing cavity 101 is too low at night, the heating mechanism 4 is started, and the heating wire inside the heating mechanism 4 generates heat to achieve the heating operation of the bearing cavity 101. In the afternoon, when the temperature inside the bearing cavity 101 is too high, the liquid pump 302 is started to make the coolant inside the liquid bag 301 start to circulate. The coolant sequentially enters the liquid bag 301, the liquid pump 302, the first side cooling water pipe 3031, the rear cooling water pipe 3032, the second side cooling water pipe 3033, and the liquid bag 301, so as to timely lower the temperature inside the bearing cavity 101 and reduce the influence of high temperature on the hardware device 7. Since the space inside the bearing cavity 101 is small and the foamed cement has a low thermal conductivity and a high thermal resistance, the heat transfer is effectively reduced, and then it is convenient to timely restore the temperature to normal and reduce the influence of high and low temperatures on the hardware device 7;

[0036] A constant temperature water tank 601 is arranged inside the foamed cement carrier 1, and a liquid with a high specific heat capacity is filled inside the constant temperature water tank 601. When the temperature difference between day and night is large, the liquid inside the constant temperature water tank 601 can play a role in temperature buffering, avoiding the too fast temperature change of the foamed cement carrier 1 and causing deformation of the optical path (such as fiber optic coupler, optical splitter) inside the demodulator, resulting in baseline wavelength shift and frequent calibration being required to maintain the accuracy;

[0037] When it is necessary to open the bearing cavity 101, the locking plate 503 can be pulled out from the lock port 103, so that the locking plate 503 is far away from the slot 502 at the upper end of the plug board 501. The plug board 501 is lifted so that the slot 502 at the lower end of the plug board 501 is aligned with the lock port 103, and the locking plate 503 is pushed so that the locking plate 503 is inserted into the slot 502 inside the lower end of the plug board 501. The plug board 501 is fixed by the locking plate 503, so that the bearing cavity 101 is connected to the outside, facilitating the staff to maintain the hardware device 7 inside the bearing cavity 101;

[0038] Photovoltaic panels 2 are arranged on both sides of the foamed cement carrier 1. Photovoltaic power generation is realized through the photovoltaic panels 2, and then power is supplied to the heating wire, the temperature detection component or the liquid pump 302 to reduce the transmission of electric energy through the main cable.

[0039] The above has described a detailed description of an embodiment of the present invention, but the content described is only the preferred embodiment of the present invention and cannot be considered as used to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. An optical fiber grating demodulator, characterized in that It includes a foamed cement carrier (1). A bearing cavity (101) and a constant temperature cavity (102) are provided inside the foamed cement carrier (1). One side of both the bearing cavity (101) and the constant temperature cavity (102) is connected to the outside. A closing mechanism (5) for isolating the bearing cavity (101) from the outside is provided at the opening of the bearing cavity (101). A hardware device (7), a temperature detection component and a temperature regulation component are provided inside the bearing cavity (101). A constant temperature component (6) is provided inside the constant temperature cavity (102). A power supply component is provided on the foamed cement carrier (1).

2. The fiber Bragg grating demodulator according to claim 1, characterized in that, The constant temperature component (6) includes a constant temperature water tank (601) provided inside the constant temperature cavity (102). A liquid injection port (602) is provided on the constant temperature water tank (601) near the opening side of the constant temperature cavity (102). A screw cap (603) is provided in cooperation with the liquid injection port (602).

3. The fiber grating demodulator according to claim 2, characterized in that, The temperature regulation component includes a cooling mechanism (3). The cooling mechanism (3) includes a liquid bag (301), a liquid pump (302) and a heat conduction water pipe (303). The liquid bag (301) is cooperatively connected with the liquid pump (302). One end of the heat conduction water pipe (303) is cooperatively connected with the liquid pump (302). The other end of the heat conduction water pipe (303) is cooperatively connected with the liquid bag (301). The liquid bag (301) is located inside the constant temperature water tank (601).

4. The fiber Bragg grating demodulator according to claim 3, characterized in that The temperature regulation component further includes a heating mechanism (4). The heating mechanism (4) includes a heating wire fixedly provided inside the bearing cavity (101). A protective cage is provided around the side of the heating wire.

5. The fiber Bragg grating demodulator according to claim 3, characterized in that, The heat conduction water pipe (303) includes a first side cooling water pipe (3031), a rear cooling water pipe (3032) and a second side cooling water pipe (3033). The first side cooling water pipe (3031), the rear cooling water pipe (3032) and the second side cooling water pipe (3033) all extend longitudinally in a reciprocating manner and are distributed on the inner wall of the bearing cavity (101). The first side cooling water pipe (3031) and the second side cooling water pipe (3033) are respectively located on both sides of the bearing cavity (101). The rear cooling water pipe (3032) is located at the rear side of the bearing cavity (101). One end of the first side cooling water pipe (3031) is communicated with the output end of the liquid pump (302), and the other end is communicated with the input end of the rear cooling water pipe (3032). The other end of the rear cooling water pipe (3032) is communicated with the second side cooling water pipe (3033). The other end of the second side cooling water pipe (3033) is connected to the liquid bag (301).

6. The fiber Bragg grating demodulator according to claim 3 or 4, characterized in that An insertion port (104) communicating with the front side of the bearing cavity (101) is provided above the foamed cement carrier (1). The closing mechanism (5) includes a plug board (501) slidably matched with the insertion port (104). A positioning component for positioning the plug board (501) is provided on the front side of the foamed cement carrier (1).

7. The fiber Bragg grating demodulator according to claim 6, wherein, A locking port (103) adapted to the socket (104) is provided on the front side of the foamed cement carrier (1). A slot (502) is provided on the insertion plate (501). The positioning assembly includes a locking plate (503) that is slidably engaged with the locking port (103) and is used to insert into the slot (502). A protruding plate is provided below the locking port (103). Locking holes for facilitating the insertion of a lock ring are provided on both the locking plate (503) and the protruding plate.

8. The fiber grating demodulator according to claim 2, characterized in that, An air exchange member is provided on the screw cap (603).

9. The fiber Bragg grating demodulator according to claim 6, characterized in that, The power supply assembly includes a photovoltaic panel (2), and the photovoltaic panel (2) is fixedly provided on both sides of the foamed cement carrier (1).

10. The fiber Bragg grating demodulator according to claim 9, wherein Slopes are provided on both sides of the foamed cement carrier (1), and each group of photovoltaic panels (2) is located on the corresponding slope.

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