Air pressure balancing device of optical fiber sensor

Abstract

The invention discloses an air pressure balancing device for an optical fiber sensor. The air pressure balancing device comprises a detection module and a pressure adjusting module, the detection module comprises a protective shell, a detection optical fiber and protective gas; the detection optical fiber and the protective gas are arranged in the protective shell; the pressure adjusting module comprises a gas transmission channel, an automatic adjusting switch and a gas storage structure; one end of the gas transmission channel communicates with the protective shell, and the other end communicates with the gas storage structure; the automatic adjusting switch is arranged in the gas transmission channel and used for adjusting connection and disconnection of a gas path between the protective shell and the gas storage structure. According to the device, gas circulation between the protection shell and the gas storage structure is achieved by additionally arranging the pressure adjusting module, the gas circulation direction can be controlled through the automatic adjusting switch, and therefore the gas pressure in the protection shell is kept stable; the problem that the measurement result of the detection optical fiber is influenced by the gas pressure change in the protective shell caused by the temperature or pressure change is solved, the measurement error is reduced, and the measurement precision is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber sensing measurement, and in particular to an optical fiber sensor air pressure equalization device. BACKGROUND

[0002] Optical fiber sensors have very important application prospects in the industrial field due to the characteristics of optical fiber sensing multi-point high-density measurement, all-optical and passive, embedded in-situ monitoring, long-distance networking, etc. When in an extremely high temperature, high pressure and high humidity application environment, the coating material of the optical fiber protection layer is directly exposed to the air, and the water molecules or oxygen in the air will accelerate the aging process of the optical fiber material, causing the refractive index change inside the optical fiber, resulting in the decline of the transmission performance of the optical fiber, thereby causing the life of the optical fiber sensor to rapidly attenuate in the extreme environment.

[0003] In order to improve the life of the optical fiber sensor, an effective method at present is to protect the optical fiber detection front end of the optical fiber sensor with a stable performance gas, but the air pressure change of the sealed protective gas will affect the measurement accuracy of the optical fiber sensor and cause measurement errors. SUMMARY

[0004] The present application provides an optical fiber sensor air pressure equalization device to eliminate measurement errors introduced by fluctuations in the air pressure of the protective gas and improve measurement accuracy.

[0005] The present application provides an optical fiber sensor air pressure equalization device, comprising a detection module and a pressure regulating module.

[0006] The detection module comprises a protective shell, a detection optical fiber and a protective gas; the detection optical fiber and the protective gas are both arranged in the protective shell;

[0007] The pressure regulating module comprises a gas transmission channel, an automatic regulating switch and a gas storage structure; one end of the gas transmission channel is in communication with the protective shell, and the other end is in communication with the gas storage structure; the automatic regulating switch is arranged in the gas transmission channel and is used to regulate the on-off of the gas path between the protective shell and the gas storage structure.

[0008] Optionally, the automatic regulating switch is a bidirectional regulating air valve.

[0009] The bidirectional regulating air valve is used to control the gas storage structure to automatically output gas to the protective shell when the gas pressure in the protective shell is less than a first preset pressure, and is also used to control the protective shell to automatically output gas to the gas storage structure when the gas pressure in the protective shell is greater than a second preset pressure; the second preset pressure is greater than or equal to the first preset pressure.

[0010] Optionally, the pressure regulating module comprises a gas supplement unit and a gas discharge unit.

[0011] The gas supplement unit comprises a first gas transmission channel, a first one-way regulating air valve and a first gas storage structure, one end of the first gas transmission channel is in communication with the protective shell, the other end of the first gas transmission channel is in communication with the first gas storage structure; the first one-way regulating air valve is located in the first gas transmission channel, and is used for regulating the opening and closing of the gas path between the protective shell and the first gas storage structure, so that the gas in the first gas storage structure enters the protective shell.

[0012] The gas discharge unit comprises a second gas transmission channel, a second one-way regulating air valve and a second gas storage structure, one end of the second gas transmission channel is in communication with the protective shell, the other end of the second gas transmission channel is in communication with the second gas storage structure; the second one-way regulating air valve is located in the second gas transmission channel, and is used for regulating the opening and closing of the gas path between the protective shell and the second gas storage structure, so that the gas in the protective shell enters the second gas storage structure.

[0013] Optionally, the automatic regulating switch comprises a mechanical air valve structure.

[0014] Optionally, the automatic regulating switch comprises a first electromagnetic air valve structure.

[0015] The optical fiber sensor pressure equalization device further comprises a pressure detection module and a first control module; the pressure detection module comprises a pressure detection signal output end, the first control module comprises a pressure detection signal receiving end and a first control signal output end, and the first electromagnetic air valve structure comprises a first control signal receiving end.

[0016] The pressure detection signal output end is connected with the pressure detection signal receiving end, and the first control signal output end is connected with the first control signal receiving end; the first control module is used for determining the first control signal output by the first control signal output end according to the pressure signal received by the pressure detection signal receiving end, so as to control the conduction state of the first electromagnetic air valve structure.

[0017] Optionally, the automatic regulating switch comprises a second electromagnetic air valve structure.

[0018] The optical fiber sensor pressure equalization device further comprises a temperature detection module and a second control module; the temperature detection module comprises a temperature detection signal output end, the second control module comprises a temperature detection signal receiving end and a second control signal output end, and the second electromagnetic air valve structure comprises a second control signal receiving end.

[0019] The temperature detection signal output end is connected with the temperature detection signal receiving end, and the second control signal output end is connected with the second control signal receiving end; the second control module is used for determining the second control signal output by the second control signal output end according to the temperature signal received by the temperature detection signal receiving end to control the conduction state of the second electromagnetic air valve structure.

[0020] Optionally, the optical fiber sensor air pressure equalization device further comprises a demodulation module, an input end of the demodulation module being connected with an output end of the probe optical fiber.

[0021] Optionally, the demodulation module comprises a conducting optical fiber and a demodulator.

[0022] One end of the conducting optical fiber is connected with the output end of the probe optical fiber, and a second end of the conducting optical fiber is connected with the demodulator.

[0023] Optionally, the demodulator comprises a test light source, an optical fiber circulator and an optical fiber spectrometer.

[0024] One end of the test light source is connected with a first end of the optical fiber circulator, a second end of the optical fiber circulator is connected with the second end of the conducting optical fiber, and a third end of the optical fiber circulator is connected with the optical fiber spectrometer.

[0025] Optionally, the optical fiber sensor air pressure equalization device further comprises a sealing module.

[0026] The input end of the demodulation module is connected with the output end of the probe optical fiber in the sealing module.

[0027] The optical fiber sensor air pressure equalization device provided by the application can realize the gas circulation between the protective shell and the gas storage structure by adding a pressure adjusting module, and can control the gas circulation direction by automatically adjusting the switch, so that the gas pressure in the protective shell is kept stable, the problem that the gas pressure in the protective shell is changed due to temperature or pressure change and then affects the measurement result of the probe optical fiber is solved, the measurement error of the optical fiber sensor air pressure equalization device is reduced, and the measurement accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A structure schematic diagram of the optical fiber sensor air pressure equalization device provided by the application is shown in the figure.

[0029] Figure 2 Another structure schematic diagram of the optical fiber sensor air pressure equalization device provided by the application is shown in the figure.

[0030] Figure 3 A structure schematic diagram of the one-way adjusting mechanical air valve provided by the application is shown in the figure.

[0031] Figure 4 Another optical fiber sensor air pressure equalization device structure schematic view provided by the embodiment of the present application is shown in the figure;

[0032] Figure 5 Another optical fiber sensor air pressure equalization device structure schematic view provided by the embodiment of the present application is shown in the figure;

[0033] Figure 6 Another optical fiber sensor air pressure equalization device structure schematic view provided by the embodiment of the present application is shown in the figure;

[0034] Figure 7 Another optical fiber sensor air pressure equalization device structure schematic view provided by the embodiment of the present application is shown in the figure. DETAILED DESCRIPTION

[0035] The present application will be further described below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures.

[0036] Figure 1 An optical fiber sensor air pressure equalization device structure schematic view provided by the embodiment of the present application is shown in the figure, Figure 1 The optical fiber sensor air pressure equalization device includes a detection module 10 and a pressure regulating module 20.

[0037] The detection module 10 includes a protective shell 101, a detection optical fiber 102 and a protective gas 103; the detection optical fiber 102 and the protective gas 103 are both arranged in the protective shell 101.

[0038] The pressure regulating module 20 includes a gas transmission channel 201, an automatic regulating switch 202 and a gas storage structure 203; one end of the gas transmission channel 201 is communicated with the protective shell 101, and the other end is communicated with the gas storage structure 203; the automatic regulating switch 202 is arranged in the gas transmission channel 201, and is used for regulating the on-off of the air path between the protective shell 101 and the gas storage structure 203.

[0039] Specifically, the probe optical fiber 102 is placed in the protective shell 101, and the protective gas 103 is filled in the protective shell 101. The protective gas 103 can be an inert gas or a non-reactive gas such as N2, which is beneficial to prolong the service life of the probe optical fiber 102. However, when the optical fiber sensor gas pressure equalization device is in an extreme measurement environment, the probe optical fiber 102 in the probe module 10 is modulated by external factors (such as temperature, pressure, strain, etc.) when light propagates in the optical fiber, so that the characteristics (such as intensity, phase, wavelength, etc.) of the probe optical fiber 102 are changed, thereby realizing high-sensitivity measurement of the measured parameters. Therefore, if the probe module 10 is in a high-temperature measurement environment, for example, 500-2000℃, the pressure of the protective gas 103 in the protective shell 101 can change due to temperature change, thereby affecting the measurement accuracy of the probe optical fiber 102. The protective shell 101 is a sealed shell, which can be a metal high-temperature protective shell or a high-temperature protective shell made of various corundum materials. The probe optical fiber 102 can be a single-point optical fiber sensor or a distributed optical fiber sensor.

[0040] Further, the pressure regulating module 20 is used to adjust the gas pressure in the protective shell 101, thereby eliminating the measurement error introduced by the gas pressure fluctuation of the protective gas 103, and improving the measurement accuracy of the probe optical fiber 102. The pressure regulating module 20 includes a gas transmission channel 201, an automatic adjusting switch 202, and a gas storage structure 203. The gas stored in the gas storage structure 203 is the same as the protective gas 103 in the protective shell 101, and the storage capacity is much larger than the storage capacity of the protective gas 103 in the protective shell 101, so the influence of the gas storage structure 203 due to the decrease of the gas pressure in the gas storage structure 203 caused by filling gas into the protective shell 101 can be ignored. The gas storage structure 203 can be a gas storage bag. One end of the gas transmission channel 201 communicates with the protective shell 101, and the other end communicates with the gas storage structure 203, which is used to realize the gas exchange between the protective shell 101 and the gas storage structure 203. The automatic adjusting switch 202 is arranged in the gas transmission channel 201, which is used to adjust the on-off of the gas path between the protective shell 101 and the gas storage structure 203, so as to keep the gas pressure in the protective shell 101 constant, thereby reducing the detection error of the probe optical fiber 102.

[0041] In the optical fiber sensor gas pressure equalization device, the pressure regulating module is added to realize the gas flow between the protective shell and the gas storage structure, and the automatic adjusting switch can control the gas flow direction, so that the gas pressure in the protective shell is kept stable, the problem of the change of the gas pressure in the protective shell caused by the change of temperature or pressure affecting the measurement result of the probe optical fiber is solved, the measurement error of the optical fiber sensor gas pressure equalization device is reduced, and the measurement accuracy is improved.

[0042] Optionally, the automatic regulating switch 202 is a bidirectional regulating air valve; the bidirectional regulating air valve is configured to control the gas storage structure 203 to output gas to the protection shell 101 when the gas pressure in the protection shell 101 is less than the first preset pressure, and is also configured to control the protection shell 101 to output gas to the gas storage structure 203 when the gas pressure in the protection shell 101 is greater than the second preset pressure; the second preset pressure is greater than or equal to the first preset pressure.

[0043] Specifically, referring to Figure 1 , the automatic regulating switch 202 is configured to control the flow direction of the protection gas 103 in the gas transmission channel 201; when the gas pressure in the protection shell 101 is less than the first preset pressure, it indicates that the gas pressure in the protection shell 101 is lower than the standard level, at this time, the bidirectional regulating air valve controls the gas storage structure 203 to output gas to the protection shell 101, so that the gas pressure in the protection shell 101 returns to the standard level, wherein the standard level refers to the gas pressure in the protection shell 101 at this time, which minimizes the measurement error of the detection optical fiber 102 caused by the gas pressure. When the gas pressure in the protection shell 101 is greater than the second preset pressure, it indicates that the gas pressure in the protection shell 101 is greater than the standard level, at this time, the bidirectional regulating air valve controls the protection shell 101 to output gas to the gas storage structure 203, so that the gas pressure in the protection shell 101 decreases and returns to the standard level.

[0044] Optionally, the second preset pressure is greater than or equal to the first preset pressure. When the second preset pressure is greater than the first preset pressure, if the gas pressure in the protection shell 101 is greater than the first preset pressure and less than the second preset pressure, at this time, the bidirectional regulating air valve is closed, and the protection gas 103 in the gas transmission channel 201 is not allowed to flow, that is, when the gas pressure in the protection shell 101 is in the range, the measurement error of the detection optical fiber 102 is small. When the second preset pressure is equal to the first preset pressure, only when the gas pressure in the protection shell 101 is equal to the first preset pressure, the bidirectional regulating air valve is in the closed state.

[0045] Optionally, Figure 2 Another structure schematic diagram of the optical fiber sensor gas pressure equalization device provided by the embodiment of the present application is shown in Figure 2 , the pressure regulating module includes a gas supplement unit 30 and a gas discharge unit 40;

[0046] The gas supplement unit 30 comprises a first gas transmission channel 301, a first one-way regulating air valve 302 and a first gas storage structure 303. One end of the first gas transmission channel 301 is in communication with the protective shell 101, and the other end of the first gas transmission channel 301 is in communication with the first gas storage structure 303. The first one-way regulating air valve 302 is located in the first gas transmission channel 301 and is used to regulate the on-off of the gas path between the protective shell 101 and the first gas storage structure 303, so that the gas in the first gas storage structure 303 enters the protective shell 101.

[0047] The gas discharge unit 40 comprises a second gas transmission channel 401, a second one-way regulating air valve 402 and a second gas storage structure 403. One end of the second gas transmission channel 401 is in communication with the protective shell 101, and the other end of the second gas transmission channel 401 is in communication with the second gas storage structure 403. The second one-way regulating air valve 402 is located in the second gas transmission channel 401 and is used to regulate the on-off of the gas path between the protective shell 101 and the second gas storage structure 403, so that the gas in the protective shell 101 enters the second gas storage structure 403.

[0048] Specifically, referring to Figure 2 , the gas supplement unit 30 and the gas discharge unit 40 can be two independent structures. The gas supplement unit 30 comprises a first gas transmission channel 301, a first one-way regulating air valve 302 and a first gas storage structure 303. When the first one-way regulating air valve 302 is in a conducting state, it only allows the protective gas 103 to flow from the first gas storage structure 303 to the protective shell 101, i.e. only increases the gas pressure in the protective shell 101. If the gas pressure in the protective shell 101 is less than the first preset pressure, the first one-way regulating air valve 302 is in a conducting state, and the protective gas 103 flows from the first gas storage structure 303 to the protective shell 101. If the gas pressure in the protective shell 101 is greater than or equal to the first preset pressure, the first one-way regulating air valve 302 should be in a closed state and not allow the gas in the first gas transmission channel 301 to flow. Continuing to refer to Figure 2 , the gas discharge unit 40 comprises a second gas transmission channel 401, a second one-way regulating air valve 402 and a second gas storage structure 403. When the second one-way regulating air valve 402 is in a conducting state, it only allows the gas in the protective shell 101 to enter the second gas storage structure 403, i.e. only reduces the gas pressure in the protective shell 101. If the gas pressure in the protective shell 101 is greater than the second preset pressure, the second one-way regulating air valve 402 is in a conducting state, and the protective gas 103 enters the second gas storage structure 403 from the protective shell 101. If the gas pressure in the protective shell 101 is less than or equal to the second preset pressure, the second one-way regulating air valve 402 should be in a closed state and not allow the gas in the second gas transmission channel 401 to flow.

[0049] In addition, the second gas storage structure 403 can be an independent structure as shown in Figure 2 The second gas storage structure 403 can also be shared with the first gas storage structure 303, that is, when the gas pressure in the protective shell 101 is greater than the second preset pressure, the second one-way regulating air valve 402 controls the protective gas 103 to enter the shared gas storage device from the protective shell 101, and when the gas pressure in the protective shell 101 is less than the first preset pressure, the first one-way air valve 302 controls the protective gas 103 to enter the protective shell 101 from the shared gas storage device, thereby realizing the recycling of the protective gas 103 and reducing gas waste.

[0050] It should be noted that Figure 2 The gas supplement unit and the gas discharge unit can be arranged on different sides of the protective shell (not shown in the figure). For example, as shown in the figure, the gas supplement unit is arranged on the upper side of the protective shell, and the gas discharge unit is arranged on the lower side of the protective shell. The present embodiment does not limit the positional relationship between the gas supplement unit and the gas discharge unit. Figure 2

[0051] The present embodiment realizes the regulation of the gas pressure in the protective shell by separately arranging the gas supplement unit and the gas discharge unit, prevents the measurement accuracy of the optical fiber sensor gas pressure equalization device from deviating due to the change of the gas pressure, and further allows the second gas storage structure in the gas discharge unit to be an independent gas storage structure, to be shared with the first gas storage structure, or to be free of the second gas storage structure, that is, to allow the protective gas to be discharged into the air, so that the optical fiber sensor gas pressure equalization device can be applied to different working scenarios by diversification.

[0052] Optionally, the automatic adjusting switch comprises a mechanical air valve structure, wherein the mechanical air valve structure can realize bidirectional regulation or unidirectional regulation. Exemplarily, the unidirectional regulating mechanical air valve can be a mechanical spring structure, Figure 3 A schematic diagram of a unidirectional regulating mechanical air valve structure provided by the present embodiment is shown in Figure 3 When the gas pressure on the left side of the air valve is greater than the gas pressure on the right side of the air valve, the left side gas will push the spring to compress, so that the gas can enter the right side of the air valve from the left side of the air valve, and when the gas pressure on the left side of the air valve is less than or equal to the gas pressure on the right side of the air valve, the spring in the air valve retracts, and the air valve is closed, thereby realizing the unidirectional flow of the gas.​

[0053] The Figure 3 The one-way regulating mechanical air valve shown in FIG. 1 is applied as the first one-way air valve 302 and the second one-way air valve 402 in the optical fiber sensor gas pressure equalization device, and reference is made to FIG. 2. Figure 2 When the gas pressure of the protective shell 101 is less than the gas pressure of the first gas storage structure 303, the first one-way air valve 302 allows the protective gas 103 to flow from the first gas storage structure 303 to the protective shell 101, thereby increasing the gas pressure of the protective shell 101; when the gas pressure of the protective shell 101 is greater than the gas pressure of the second gas storage structure 403, the second one-way air valve 402 allows the protective gas 103 to flow from the protective shell 101 to the second gas storage structure 403, thereby reducing the gas pressure of the protective shell 101.

[0054] Optionally, Figure 4 Another structure schematic diagram of the optical fiber sensor gas pressure equalization device provided by the embodiment of the present application is shown in FIG. 4. Figure 4 As shown in FIG. 4, the automatic regulating switch 202 includes a first electromagnetic air valve structure 2022.

[0055] The optical fiber sensor gas pressure equalization device further includes a pressure detection module 501 and a first control module 502; the pressure detection module 501 includes a pressure detection signal output end 5011, the first control module 502 includes a pressure detection signal receiving end 5021 and a first control signal output end 5022, and the first electromagnetic air valve structure 2022 includes a first control signal receiving end 2023.

[0056] The pressure detection signal output end 5011 is connected with the pressure detection signal receiving end 5021, and the first control signal output end 5022 is connected with the first control signal receiving end 2023; the first control module 502 is configured to determine the first control signal output by the first control signal output end 5022 according to the pressure signal received by the pressure detection signal receiving end 5021, so as to control the conduction state of the first electromagnetic air valve structure 2022.

[0057] Specifically, reference is made to FIG. 4. Figure 4The first electromagnetic valve structure 2022 is an electronic component that can be opened and closed using electronic signals, thus having higher sensitivity. The first electromagnetic valve structure 2022 can be a two-way guide vent valve or a one-way guide vent valve. It is understandable that if the first electromagnetic valve structure 2022 is a one-way guide vent valve, two independent gas transmission channels are required, and the two independent first electromagnetic valve structures 2022 are respectively placed in the two independent gas transmission channels to achieve gas discharge and replenishment. This embodiment is described using the first electromagnetic valve structure 2022 as a two-way guide vent valve, and defines forward conduction as the first electromagnetic valve structure 2022 allowing the protective gas 103 to enter the gas storage structure 203 from the protective housing 101, and defines reverse conduction as the first electromagnetic valve structure 2022 allowing the protective gas 103 to enter the protective housing 101 from the gas storage structure 203.

[0058] Continue to refer Figure 4 The pressure detection module 501 is located within the protective housing 101 and is used to detect the gas pressure within the protective housing 101 in real time and transmit the detected signal to the first control module 502 via the pressure detection signal output terminal 5011. For example, the pressure detection module 501 may be a pressure sensor. A first pressure threshold and a second pressure threshold are set in the first control module 502. When the gas pressure within the protective housing 101 changes, the pressure detection signal receiving terminal 5021 transmits the pressure detection signal to the first control module 502, where the pressure detection signal is compared with the first and second pressure thresholds. When the measured pressure value is less than the first pressure threshold, the first control signal output terminal 5022 outputs a first control signal that reverses the flow of the first electromagnetic valve structure 2022, i.e., allows the protective gas 103 to enter the protective housing 101 from the gas storage structure 203, thereby increasing the gas pressure within the protective housing 101. When the measured pressure value is greater than the second pressure threshold, the first control signal outputted by the first control signal output terminal 5022 causes the first electromagnetic valve structure 2022 to conduct forward, i.e., allows the protective gas 103 to enter the gas storage structure 203 from the protective housing 101, thereby reducing the gas pressure in the protective housing 101. The second pressure threshold is greater than or equal to the first pressure threshold. When the measured pressure value is greater than or equal to the first pressure threshold and less than or equal to the second pressure threshold, the first control signal outputted by the first control signal output terminal 5022 causes the first electromagnetic valve structure 2022 to close.

[0059] Optionally, Figure 5 A schematic structural diagram of another optical fiber sensor pressure equalization device provided in an embodiment of the present invention is shown in FIG. Figure 5 As shown, the automatic regulating switch 202 includes a second electromagnetic valve structure 2024;

[0060] The optical fiber sensor air pressure equalization device further comprises a temperature detection module 601 and a second control module 602; the temperature detection module 601 comprises a temperature detection signal output end 6011, the second control module 602 comprises a temperature detection signal receiving end 6021 and a second control signal output end 6022, and the second electromagnetic air valve structure 2024 comprises a second control signal receiving end 2025;

[0061] The temperature detection signal output end 6011 is connected with the temperature detection signal receiving end 6021, and the second control signal output end 6022 is connected with the second control signal receiving end 2025; the second control module 602 is used for determining the second control signal output by the second control signal output end 6022 according to the temperature signal received by the temperature detection signal receiving end 6021, so as to control the conduction state of the second electromagnetic air valve structure 2024.

[0062] Specifically, when the optical fiber sensor air pressure equalization device is used for high-temperature detection, due to the thermal expansion and cold shrinkage effect, when the external temperature of the protective shell 101 changes, the temperature in the protective shell 101 will change accordingly, so that the pressure of the protective gas 103 increases or decreases, therefore, the temperature detection module 601 is arranged in the optical fiber sensor air pressure equalization device, which can further adjust the gas pressure in the protective shell 101, thereby further reducing the measurement error of the optical fiber sensor air pressure equalization device.

[0063] With reference to the foregoing Figure 5 The second electromagnetic air valve structure 2024 can be a bidirectional conduction air valve or a unidirectional conduction air valve, and the embodiment is also described by taking the second electromagnetic air valve structure 2024 as a bidirectional conduction air valve.

[0064] Part of the temperature detection module 601 is located in the protective shell 101, which is used to detect the temperature change in the protective shell 101. Exemplarily, the temperature detection module 601 can be a thermocouple. The first temperature threshold and the second temperature threshold are set in the second control module 602. When the temperature in the protective shell 101 changes, the temperature detection signal receiving end 6021 transmits the temperature detection signal to the second control module 602 and compares it with the first temperature threshold and the second temperature threshold in the second control module 602. When the measured temperature value is less than the first temperature threshold, it indicates that the gas pressure in the protective shell 101 is small at this time, and the second control signal output end 6022 outputs the second control signal to make the second electromagnetic air valve structure 2025 reverse conduction, that is, to make the protective gas 103 enter the protective shell 101 from the gas storage structure 203, thereby increasing the gas pressure in the protective shell 101. When the measured temperature value is greater than the second temperature threshold, it indicates that the gas pressure in the protective shell 101 is large at this time, and the second control signal output end 6022 outputs the second control signal to make the second electromagnetic air valve structure 2024 forward conduction, that is, to make the protective gas 103 enter the gas storage structure 203 from the protective shell 101, thereby reducing the gas pressure in the protective shell 101. The second temperature threshold is greater than or equal to the first temperature threshold. When the measured temperature value is greater than or equal to the first temperature threshold and less than or equal to the second temperature threshold, the second control signal output end 6022 outputs the second control signal to make the second electromagnetic air valve structure 2024 closed.

[0065] The embodiment of the present application improves the adjustment speed of the gas pressure in the protective shell by using an electric signal to control the electromagnetic air valve structure. At the same time, by increasing the temperature detection module, the gas pressure in the protective shell can be directly adjusted through temperature change, further enhancing the detection accuracy of the optical fiber sensor gas pressure equalization device in a high temperature environment.

[0066] Optionally, Figure 6 Another structure schematic diagram of the optical fiber sensor gas pressure equalization device provided by the embodiment of the present application is shown in Figure 6 As shown, the optical fiber sensor gas pressure equalization device further comprises a demodulation module 70, and an input end of the demodulation module 70 is connected with an output end of the probe optical fiber 102.

[0067] Specifically, the optical signal in the probe optical fiber 102 contains information of the measured physical quantity. The optical signal output from the probe optical fiber 102 can be extracted, converted and analyzed by the demodulation module 70, so as to obtain accurate information of the measured physical quantity and obtain a detection conclusion.

[0068] Optionally, the demodulation module 70 comprises a transmission optical fiber 701 and a demodulator 702, one end of the transmission optical fiber 701 is connected with the output end of the probe optical fiber 102, and the second end of the transmission optical fiber 701 is connected with the demodulator 702.

[0069] Specifically, referring to Figure 6 , the detection optical fiber 102 outputs the modulated optical signal into the transmission optical fiber 701, and the transmission optical fiber 701 transmits the optical signal into the demodulator 702. The transmission optical fiber 701 has the advantages of anti-electromagnetic interference, long-distance lossless transmission and multi-parameter integration, and the demodulator 702 is responsible for converting the optical signal into usable physical quantity data, completing signal analysis and data output. Exemplarily, the demodulator 702 can be a single integrated demodulator.

[0070] Optionally, Figure 7 Another structure diagram of the optical fiber sensor air pressure equalization device provided by the embodiment of the present application is shown in Figure 7 The demodulator 702 includes a test light source 7021, an optical fiber circulator 7022 and an optical fiber spectrometer 7023. One end of the test light source 7021 is connected with a first end of the optical fiber circulator 7022, a second end of the optical fiber circulator 7022 is connected with a second end of the transmission optical fiber 701, and a third end of the optical fiber circulator 7022 is connected with the optical fiber spectrometer 7023.

[0071] Specifically, the optical fiber circulator 7022 has a fixed optical signal transmission direction, which can realize directional transmission of the optical signal. The test light source 7021 emits an optical signal into the first end of the optical fiber circulator 7022, and the optical signal is output from the second end of the optical fiber circulator 7022 to the transmission optical fiber 701. The transmission optical fiber 701 further transmits the optical signal to the detection optical fiber 102. The detection optical fiber 102 converts the to-be-detected physical quantity into a modulated optical signal and transmits the modulated optical signal back to the transmission optical fiber 701. The modulated optical signal is transmitted back to the second end of the optical fiber circulator 7022 through the transmission optical fiber 701. The second end of the optical fiber circulator 7022 receives the modulated optical signal and outputs the modulated optical signal to the third end of the optical fiber circulator 7022. Finally, the modulated optical signal enters the optical fiber spectrometer 7023 for optical signal demodulation.

[0072] Optionally, as shown in Figure 6 and Figure 7 The optical fiber sensor air pressure equalization device further includes a sealing module 80. The input end of the demodulation module 70 is connected with the output end of the detection optical fiber 102 in the sealing module 80, so as to realize the close connection between the detection module 10 and the demodulation module 70 and enhance the accuracy of the detection result.

[0073] Note that the above merely describes preferred embodiments of the present application and the principles of the technology applied. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, modifications and substitutions can be made without departing from the scope of the present application. Therefore, although the present application has been described in detail through the above embodiments, the present application is not limited to the above embodiments, and can include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the claims.

Claims

1. An optical fiber sensor air pressure equalization device, characterized in that: Including detection module and pressure regulation module; The detection module includes a protective shell, a detection optical fiber and a protective gas; the detection optical fiber and the protective gas are both arranged in the protective shell; The pressure regulating module includes a gas transmission channel, an automatic regulating switch and a gas storage structure; one end of the gas transmission channel is connected to the protective shell, and the other end is connected to the gas storage structure; the automatic regulating switch is arranged in the gas transmission channel, and is used to adjust the open and close of the gas path between the protective shell and the gas storage structure.

2. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The automatic regulating switch is a two-way regulating valve; The two-way regulating gas valve is used to control the gas storage structure to output gas to the protective shell when the gas pressure in the protective shell is less than a first preset pressure, and is also used to control the protective shell to output gas to the gas storage structure when the gas pressure in the protective shell is greater than a second preset pressure; the second preset pressure is greater than or equal to the first preset pressure.

3. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The pressure regulating module includes a gas replenishing unit and a gas discharging unit; The gas replenishment unit includes a first gas transmission channel, a first one-way regulating gas valve, and a first gas storage structure. One end of the first gas transmission channel is connected to the protective shell, and the other end of the first gas transmission channel is connected to the first gas storage structure. The first one-way regulating gas valve is located in the first gas transmission channel and is used to adjust the connection and disconnection of the gas path between the protective shell and the first gas storage structure so that the gas in the first gas storage structure enters the protective shell. The gas discharge unit includes a second gas transmission channel, a second one-way regulating gas valve and a second gas storage structure. One end of the second gas transmission channel is connected to the protective shell, and the other end of the second gas transmission channel is connected to the second gas storage structure; the second one-way regulating gas valve is located in the second gas transmission channel, and is used to adjust the open and close of the gas path between the protective shell and the second gas storage structure so that the gas in the protective shell enters the second gas storage structure.

4. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The automatic regulating switch includes a mechanical air valve structure.

5. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The automatic regulating switch includes a first electromagnetic valve structure; The optical fiber sensor air pressure equalization device further includes a pressure detection module and a first control module; the pressure detection module includes a pressure detection signal output terminal, the first control module includes a pressure detection signal receiving terminal and a first control signal output terminal, and the first electromagnetic valve structure includes a first control signal receiving terminal; The pressure detection signal output end is connected to the pressure detection signal receiving end, and the first control signal output end is connected to the first control signal receiving end; the first control module is used to determine the first control signal output by the first control signal output end according to the pressure signal received by the pressure detection signal receiving end to control the conduction state of the first solenoid valve structure.

6. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The automatic regulating switch includes a second electromagnetic valve structure; The optical fiber sensor pressure equalization device further includes a temperature detection module and a second control module; the temperature detection module includes a temperature detection signal output terminal, the second control module includes a temperature detection signal receiving terminal and a second control signal output terminal, and the second electromagnetic valve structure includes a second control signal receiving terminal; The temperature detection signal output end is connected to the temperature detection signal receiving end, and the second control signal output end is connected to the second control signal receiving end; the second control module is used to determine the second control signal output from the second control signal output end according to the temperature signal received by the temperature detection signal receiving end to control the conduction state of the second solenoid valve structure.

7. The optical fiber sensor air pressure equalization device according to claim 1, characterized in that: The optical fiber sensor air pressure equalization device further comprises a demodulation module, the input end of the demodulation module is connected to the output end of the detection optical fiber.

8. The optical fiber sensor air pressure equalization device according to claim 7, characterized in that: The demodulation module includes a transmission optical fiber and a demodulator; One end of the transmission optical fiber is connected to the output end of the detection optical fiber, and the second end of the transmission optical fiber is connected to the demodulator.

9. The optical fiber sensor air pressure equalization device according to claim 8, characterized in that: The demodulator includes a test light source, an optical fiber circulator and an optical fiber spectrometer; One end of the test light source is connected to the first end of the fiber optic circulator, the second end of the fiber optic circulator is connected to the second end of the transmission optical fiber, and the third end of the fiber optic circulator is connected to the fiber optic spectrometer.

10. The optical fiber sensor air pressure equalization device according to claim 7, characterized in that: The optical fiber sensor air pressure equalization device further includes a sealing module; The input end of the demodulation module and the output end of the detection optical fiber are connected in the sealing module.

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