CN114607944A - Natural gas pipeline leakage monitoring device and method - Google Patents
Natural gas pipeline leakage monitoring device and method Download PDFInfo
- Publication number
- CN114607944A CN114607944A CN202210170692.9A CN202210170692A CN114607944A CN 114607944 A CN114607944 A CN 114607944A CN 202210170692 A CN202210170692 A CN 202210170692A CN 114607944 A CN114607944 A CN 114607944A
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- pipeline
- natural gas
- gas
- sensing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title claims abstract description 162
- 239000003345 natural gas Substances 0.000 title claims abstract description 55
- 238000012806 monitoring device Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims abstract description 13
- 239000013307 optical fiber Substances 0.000 claims abstract description 92
- 239000007789 gas Substances 0.000 claims abstract description 86
- 238000001514 detection method Methods 0.000 claims abstract description 43
- 239000002689 soil Substances 0.000 claims abstract description 6
- 239000000835 fiber Substances 0.000 claims description 9
- DQXBYHZEEUGOBF-UHFFFAOYSA-N but-3-enoic acid;ethene Chemical compound C=C.OC(=O)CC=C DQXBYHZEEUGOBF-UHFFFAOYSA-N 0.000 claims description 7
- 239000005038 ethylene vinyl acetate Substances 0.000 claims description 7
- 238000012544 monitoring process Methods 0.000 claims description 7
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims description 7
- 230000004044 response Effects 0.000 claims description 7
- 229920000915 polyvinyl chloride Polymers 0.000 claims description 6
- 239000004800 polyvinyl chloride Substances 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 5
- 239000004698 Polyethylene Substances 0.000 claims description 3
- -1 polyethylene Polymers 0.000 claims description 3
- 229920000573 polyethylene Polymers 0.000 claims description 3
- 238000012545 processing Methods 0.000 claims description 3
- 239000004744 fabric Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- 238000012423 maintenance Methods 0.000 abstract description 2
- 230000035945 sensitivity Effects 0.000 abstract description 2
- 238000005516 engineering process Methods 0.000 description 7
- 239000012528 membrane Substances 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- 238000001931 thermography Methods 0.000 description 2
- 230000009471 action Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000005236 sound signal Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
- F17D5/005—Protection or supervision of installations of gas pipelines, e.g. alarm
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
- F17D5/02—Preventing, monitoring, or locating loss
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
- F17D—PIPE-LINE SYSTEMS; PIPE-LINES
- F17D5/00—Protection or supervision of installations
- F17D5/02—Preventing, monitoring, or locating loss
- F17D5/04—Preventing, monitoring, or locating loss by means of a signalling fluid enclosed in a double wall
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Investigating Or Analysing Materials By Optical Means (AREA)
- Examining Or Testing Airtightness (AREA)
Abstract
The invention belongs to the technical field of natural gas pipeline leakage detection, and discloses a natural gas pipeline leakage monitoring device and a method, wherein the natural gas pipeline leakage monitoring device comprises a sensing pipeline, the sensing pipeline is laid above an underground natural gas pipeline in parallel with the natural gas pipeline, leaked gas in the natural gas pipeline can enter the sensing pipeline, a plurality of gas detection units are arranged in the sensing pipeline, the end part of the sensing pipeline extends out of the ground and is connected with an air suction pump, a standard optical fiber extends into soil from the ground and is connected with each gas detection unit, then extends out of the ground and is connected with a signal analysis unit, the standard optical fiber transmits a laser beam to the gas detection units, and the signal analysis unit analyzes the laser signal intensity of the gas detection units so as to judge whether methane leakage exists. The invention can provide higher detection accuracy and sensitivity for slight gas leakage, early warning and maintenance and reduce the accident occurrence probability. The device has the advantages of small volume, low cost, low power consumption, and high stability and reliability.
Description
Technical Field
The invention belongs to the technical field of natural gas pipeline leakage detection, and particularly relates to a natural gas pipeline leakage monitoring device and method.
Background
The pipeline transportation is the most common mode of natural gas transportation, and has the advantages of safety, reliability, low energy consumption, no pollution and basically no influence from climate. Long-distance natural gas pipelines often pass through areas with complex terrains such as rivers, mountainous regions, goafs and the like, and pipelines are easy to be damaged by third parties to cause pipeline leakage. If the pipeline is not exposed or leaked in time and corresponding measures are taken, certain economic loss is inevitably caused to a pipeline operation unit, and serious accidents such as casualties and the like can be caused in severe cases.
Pipe leaks typically cause changes in the characteristics of the pipe's internal pressure, flow, sound waves, etc. Thus, a pipe leak can be detected by monitoring the change in the relevant quantity. In the past decades, researchers have proposed various technologies for detecting natural gas pipeline leakage, such as acoustic sensing technology, thermal imaging technology, and distributed optical fiber sensing technology. In addition, chinese patent CN105299477A discloses an oil and gas pipeline leakage monitoring system, which includes a monitoring center, a plurality of monitoring substations, an optical fiber sensing analyzer, a laser, a sensing optical cable and a gas-sensitive sensing array of a distributed device, and can effectively monitor oil and gas leakage, timely locate the leakage site, reduce the trouble of manual investigation, and reduce loss and harm.
The acoustic sensing technology is used for detecting the pipeline by using the acoustic characteristics of a leakage source and the propagation rule of sound waves in the pipeline, but slight leakage can generate a small sound signal, and the system cannot detect background noise, so that many false alarms appear in the system. The pipeline leakage detection based on the infrared thermography technology is difficult to distinguish normal pressure waves from leakage, and the method is only effective to large-scale instantaneous leakage and is easy to cause false alarm. The distributed optical fiber acoustic sensing technology has many problems in the aspects of multi-point detection, environmental interference resistance, positioning accuracy improvement, automatic identification of vibration source types and the like.
Disclosure of Invention
The invention aims to provide a natural gas pipeline leakage monitoring device and a method, which aim to solve the technical problem.
In order to solve the technical problems, the specific technical scheme of the natural gas pipeline leakage monitoring device and the method is as follows:
a natural gas pipeline leakage monitoring device comprises a sensing pipeline, the sensing pipeline is laid in parallel with the natural gas pipeline along the upper part of the underground natural gas pipeline, the sensing pipeline is permeable to gas and impermeable to liquid, gas leaked from the natural gas pipeline can enter the sensing pipeline, a plurality of gas detection units are arranged in the sensing pipeline, the gas detection units are nested and sealed with the sensing pipeline, the gas detection units are used for detecting signals of the leaked gas collected in the sensing pipeline, the end part of the sensing pipeline extends out of the ground and is connected with an air suction pump, the air suction pump is used for conveying the gas in the sensing pipeline to the gas detection units, standard optical fibers extend into soil from the ground and then extend out of the ground to be connected with a signal analysis unit after being connected with each gas detection unit, and the standard optical fibers convey laser beams to the gas detection units, the signal analysis unit analyzes the laser signal intensity of the gas detection unit to judge whether methane leakage exists.
Further, the sensing pipeline is laid along the natural gas pipeline 10-20cm above the natural gas pipeline in parallel.
Further, the sensing pipeline comprises a polyvinyl chloride pipe with an array of holes, an ethylene-vinyl acetate membrane covers the polyvinyl chloride pipe, the ethylene-vinyl acetate membrane is permeable to gas but impermeable to liquid, and a polyethylene braided fabric wraps the outside of the ethylene-vinyl acetate membrane.
Further, the interval between each gas detection unit is 5-10 m.
The device further comprises a current controller, a temperature controller, a distributed feedback laser and a bismuth-doped optical fiber power amplifier, wherein the current controller and the temperature controller are connected with the distributed feedback laser, the distributed feedback laser is connected with the bismuth-doped optical fiber power amplifier, and the bismuth-doped optical fiber power amplifier is connected with a standard optical fiber; the current controller is used for controlling the output current of the distributed feedback laser; the temperature controller is used for controlling the working temperature of the distributed feedback laser; the distributed feedback laser is used for emitting laser beams; the bismuth-doped optical fiber power amplifier is used for amplifying the output power of the distributed feedback laser.
Further, the gas detection unit comprises a first optical fiber coupler, a hollow-core photonic band gap type optical fiber and a second optical fiber coupler; the standard optical fiber is connected with a first optical fiber coupler, the first optical fiber coupler is connected with a hollow photonic band gap type optical fiber, the hollow photonic band gap type optical fiber is connected with a second optical fiber coupler, the second optical fiber coupler is connected with the next section of standard optical fiber, and the next section of standard optical fiber is connected with the next gas detection unit.
Furthermore, the signal analysis unit comprises a photoelectric detector, a phase-locked amplifier and a data processing center, the standard optical fiber is connected with the photoelectric detector after extending out of the ground, the photoelectric detector is connected with the phase-locked amplifier, and the phase-locked amplifier is connected with the data processing center; the photoelectric detector outputs corresponding electric signals according to the detected laser signal intensity, and the lock-in amplifier is used for detecting second harmonic signals in the electric signals output by the photoelectric detector; the data processing center is used for data processing and displaying, and comprises a display unit for displaying whether methane leakage exists or not, displaying the methane leakage concentration and calculating the leakage position according to the response time of the second harmonic signal.
Further, the hollow-core photonic band gap type optical fiber is 1m long, and a plurality of air holes are formed in one side of the hollow-core photonic band gap type optical fiber.
The invention also discloses a method for monitoring the leakage of the natural gas pipeline, which comprises the following steps:
step 1: connecting an air pump with the sensing pipeline, and opening the air pump to convey the gas in the sensing pipeline from left to right;
step 2: loading a combined modulation signal to a current controller, setting a temperature controller to be 27-30 ℃, and controlling a distributed feedback laser to output a laser beam;
and step 3: connecting the distributed feedback laser to a bismuth-doped optical fiber power amplifier, and amplifying the output power of the distributed feedback laser to 160-200 mW;
and 4, step 4: then, the laser passing through the bismuth-doped optical fiber power amplifier is injected into the gas detection unit through the standard optical fiber, so that the laser beam of the distributed feedback laser enters the hollow photonic band gap type optical fiber 9;
and 5: when the natural gas pipeline leaks, the sensing pipeline collects the leaked methane gas into the sensing pipeline and starts to convey from left to right;
step 6: when leaked methane gas enters the hollow-core photonic band-gap type optical fiber, according to the Lambert-beer law, a laser beam of the standard optical fiber conveying distributed feedback laser is contacted with and absorbed by the methane gas in the hollow-core photonic band-gap type optical fiber, the laser intensity is weakened, the photoelectric detector outputs a corresponding electric signal according to the detected laser signal intensity, wherein a second harmonic term in the electric signal is in direct proportion to the concentration of the leaked gas, the phase-locked amplifier detects a second harmonic signal in the electric signal output by the photoelectric detector, and the concentration of the leaked gas is determined according to the second harmonic signal intensity;
and 7: and finally, the data processing center displays whether the second harmonic signal detected by the phase-locked amplifier leaks or not, inverts the methane leakage concentration according to the amplitude of the second harmonic signal and calculates the leakage position according to the response time of the second harmonic signal.
Further, the modulation signal of the step includes a high-frequency sine signal with an amplitude of 800mV and 5kHz and a sawtooth wave scanning signal with 10Hz, the distributed feedback laser is controlled to output a laser beam with a center wavelength of 1650nm, the power is 3-5mw, and the line width is less than 10 MHz.
The natural gas pipeline leakage monitoring device and the method have the following advantages that: the invention provides a natural gas pipeline leakage monitoring method of hollow photonic band-gap type optical fiber gas sensing by utilizing the advantages of hollow optical fiber gas sensing, which utilizes a hollow photonic band-gap type optical fiber as a gas absorption pool to absorb trace leakage gas collected in a sensing pipeline, and then detects methane gas absorption signals leaked from the natural gas pipeline through a photoelectric detector, thereby determining the leakage position of the pipeline in time, simplifying operation and reducing cost, simultaneously providing higher detection accuracy and sensitivity for slight leakage gas leakage, early warning and overhauling and reducing accident occurrence probability. Compared with the traditional distributed optical fiber detection method, the natural gas pipeline leakage detection method provided by the invention has the advantages of small volume, low cost and lower power consumption, improves the stability and reliability of the instrument, and simultaneously reduces the maintenance cost of the equipment.
Drawings
FIG. 1 is a schematic structural diagram of a natural gas pipeline leakage monitoring device according to the present invention;
the notation in the figure is: 1. an air pump; 2. a bismuth-doped optical fiber power amplifier; 3. a distributed feedback laser; 4. a current controller; 5. a temperature controller; 6. a gas detection unit; 7. a standard optical fiber; 8. a first fiber coupler; 9. a hollow core photonic band gap type optical fiber; 10. a second fiber coupler; 11. a photodetector; 12. a phase-locked amplifier; 13. a data processing center; 14. a sensing conduit; 15. a leak point; 16. a natural gas pipeline; 17. underground soil.
Detailed Description
For better understanding of the objects, structure and functions of the present invention, a natural gas pipeline leakage monitoring device and method according to the present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 1, a natural gas pipeline 16 is buried in underground soil 17, and a natural gas pipeline leakage monitoring device of the present invention includes a sensing pipeline 14, the sensing pipeline 14 is laid parallel to the natural gas pipeline 16 at a position 10-20cm above the natural gas pipeline 16, the sensing pipeline 14 is composed of three parts including a polyvinyl chloride pipe with an array of holes, the polyvinyl chloride pipe is covered with a thin ethylene-vinyl acetate film which is permeable to gas but impermeable to liquid, and finally, the outside is protected with a polyethylene braid. The gas permeable structure of the sensing pipe 14 allows gas leaking from the natural gas pipe to easily enter the inside of the sensing pipe. The end of the sensing pipe 14 extends out of the ground and is connected with a suction pump 1, and the suction pump 1 is used for conveying gas in the sensing pipe from left to right. The sensing pipeline 14 is internally provided with a plurality of gas detection units 6, the gas detection units 6 are nested and sealed with the sensing pipeline 14, the gas detection units 6 are used for detecting signals of leaked gas collected in the sensing pipeline 14, and the interval between every two gas detection units 6 is about 5-10 m. The current controller 4 and the temperature controller 5 are connected with the distributed feedback laser 3, the distributed feedback laser 3 is connected with the bismuth-doped optical fiber power amplifier 2, the bismuth-doped optical fiber power amplifier 2 is connected with the standard optical fiber 7, and the standard optical fiber 7 extends into soil from the ground, is connected with each gas detection unit 6, then extends out of the ground and is connected with the signal analysis unit. The signal analysis unit comprises a photodetector 11, a lock-in amplifier 12 and a data processing center 13. The standard optical fiber 7 extends out of the ground and is connected with a photoelectric detector 11, the photoelectric detector 11 is connected with a phase-locked amplifier 12, and the phase-locked amplifier 12 is connected with a data processing center 13. The standard optical fibre 7 is used to lead out the laser beam of the distributed feedback laser 3. The current controller 4 is used to control the output current of the distributed feedback laser 3. The temperature controller 5 is used to control the operating temperature of the distributed feedback laser 3. The distributed feedback laser 3 is used to emit a laser beam. The bismuth-doped optical fiber power amplifier 2 is used for amplifying the output power of the distributed feedback laser 3. The photodetector 11 outputs a corresponding electrical signal according to the detected intensity of the laser signal, and the lock-in amplifier 12 is used for detecting a second harmonic signal in the electrical signal output by the photodetector 11. The data processing center 13 is a computer for data processing and display, including displaying whether there is methane leak, the methane leak concentration, and calculating the leak location based on the response time.
When the natural gas pipeline 16 leaks, the sensing pipeline 14 absorbs methane gas, and the gas is conveyed from left to right in the sensing pipeline 14 under the action of the air suction pump 1. Leaked methane gas enters the gas detection unit 6, the intensity of laser transmitted by the standard optical fiber 7 is weakened after being absorbed by the leaked gas, the photoelectric detector 11 outputs corresponding electric signals (including various noises and various subharmonic signals) according to the intensity of the laser in the gas detection unit 6, the phase-locked amplifier 12 detects the second harmonic signal in the electric signals output by the photoelectric detector 11, and finally the methane leakage concentration is obtained through the data processing center 13 and the leakage position is calculated according to the response time of the second harmonic signal.
Specifically, the gas detection unit 6 includes a first fiber coupler 8, a hollow-core photonic band gap type fiber 9, and a second fiber coupler 10. The standard optical fiber 7 is connected with the first optical fiber coupler 8, the first optical fiber coupler 8 is connected with the hollow photonic band gap type optical fiber 9, the hollow photonic band gap type optical fiber 9 is connected with the second optical fiber coupler 10, the second optical fiber coupler 10 is connected with the next section of standard optical fiber 7, and the next section of standard optical fiber 7 is connected with the next gas detection unit 6. The length of the hollow-core photonic band-gap type optical fiber 9 is 1m, and 10 air holes with small diameters are formed in one side of the hollow-core photonic band-gap type optical fiber, so that air can enter the hollow-core photonic band-gap type optical fiber 9 more fully.
The distributed feedback laser adopts NP-ICL-1650-T066 produced by Nanoplus company, the center output wavelength is 1650nm, the power is 3-5mw, and the line width is less than 10 MHz.
The photodetector is an MCT photodetector manufactured by VIGO system.
The phase lock amplifier employs SR830 manufactured by STANFORD corporation.
The detection method of the device comprises the following steps:
step 1: the air pump 1 is connected with the sensing pipeline 14, and the air pump 1 is opened to convey the gas in the sensing pipeline 14 from left to right.
Step 2: and loading a combined modulation signal comprising a high-frequency sinusoidal signal with the amplitude of 800mV and 5kHz and a sawtooth wave scanning signal with the amplitude of 10Hz to the current controller 4, setting the temperature controller 5 to be 27-30 ℃, and controlling the distributed feedback laser 3 to output a laser beam with the central wavelength of 1650nm, wherein the power is more than 3-5mw, and the line width is less than 10 MHz.
And step 3: the distributed feedback laser 3 is connected to the bismuth-doped fiber power amplifier 2, and the output power of the distributed feedback laser 3 is amplified to 160-200 mW.
And 4, step 4: and then, the laser passing through the bismuth-doped optical fiber power amplifier 2 is emitted into the gas detection unit 6 through the standard optical fiber 7, so that the laser beam of the distributed feedback laser 3 enters the hollow-core photonic band gap type optical fiber 9.
And 5: when a natural gas pipeline leakage point 15 leaks, the sensing pipeline 14 collects the leaked methane gas into the sensing pipeline 14 and starts to convey from left to right.
Step 6: when leaked methane gas enters the hollow-core photonic band gap type optical fiber 9, according to the lambert-beer law, the standard optical fiber 7 conveys laser beams of the distributed feedback laser 3 to be in contact with and absorbed by the methane gas in the hollow-core photonic band gap type optical fiber 9, the laser intensity is weakened, at the moment, the photoelectric detector 11 outputs corresponding electric signals (including various noises and various harmonic signals mixed) according to the detected laser signal intensity, wherein a second harmonic term in the output electric signals is in direct proportion to the concentration of the leaked gas, the phase-locked amplifier 12 detects the second harmonic signal in the electric signals, and the concentration of the leaked gas is determined according to the intensity of the second harmonic signal.
And 7: finally, the data processing center 13 can display whether the second harmonic signal detected by the lock-in amplifier 12 leaks or not, invert the methane leakage concentration according to the amplitude of the second harmonic signal and calculate the leakage position according to the response time of the second harmonic signal.
It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims (10)
1. A natural gas pipeline leakage monitoring device comprises a sensing pipeline (14), wherein the sensing pipeline (14) is laid above an underground natural gas pipeline (16) in parallel with the natural gas pipeline (16), the sensing pipeline (14) is made of a gas permeable and liquid impermeable material, leaked gas in the natural gas pipeline (16) can enter the sensing pipeline (14), the natural gas pipeline leakage monitoring device is characterized in that a plurality of gas detection units (6) are arranged in the sensing pipeline (14), the gas detection units (6) are nested and sealed with the sensing pipeline (14), the gas detection units (6) are used for detecting signals of the leaked gas collected in the sensing pipeline (14), the end part of the sensing pipeline (14) extends out of the ground and is connected with an air suction pump (1), and the air suction pump (1) is used for conveying the gas in the sensing pipeline (14) to the gas detection units (6), standard optical fiber (7) stretches into soil from ground and stretches out from ground after connecting each gas detecting element (6) and connect signal analysis unit, standard optical fiber (7) carry laser beam to gas detecting element (6), and signal analysis unit analysis gas detecting element's (6) laser signal intensity thereby judges whether has methane leakage.
2. The natural gas pipeline leakage monitoring device according to claim 1, wherein the sensor pipeline (14) is laid parallel to the natural gas pipeline (16) along a distance of 10-20cm above the natural gas pipeline (16).
3. The natural gas pipeline leak monitoring device of claim 1, wherein the sensing pipeline (14) comprises a polyvinyl chloride pipe with an array of holes, the polyvinyl chloride pipe is externally covered by an ethylene-vinyl acetate film, the ethylene-vinyl acetate film is permeable to gas and impermeable to liquid, and the ethylene-vinyl acetate film is externally wrapped by a polyethylene braided fabric.
4. The natural gas pipeline leakage monitoring device according to claim 1, wherein the interval between each of the gas detection units (6) is 5-10 m.
5. The natural gas pipeline leakage monitoring device according to claim 1, comprising a current controller (4), a temperature controller (5), a distributed feedback laser (3) and a bismuth-doped optical fiber power amplifier (2), wherein the current controller (4) and the temperature controller (5) are connected with the distributed feedback laser (3), the distributed feedback laser (3) is connected with the bismuth-doped optical fiber power amplifier (2), and the bismuth-doped optical fiber power amplifier (2) is connected with a standard optical fiber (7); the current controller (4) is used for controlling the output current of the distributed feedback laser (3); the temperature controller (5) is used for controlling the working temperature of the distributed feedback laser (3); the distributed feedback laser (3) is used for emitting a laser beam; the bismuth-doped optical fiber power amplifier (2) is used for amplifying the output power of the distributed feedback laser (3).
6. The natural gas pipeline leakage monitoring device according to claim 1, wherein the gas detection unit (6) comprises a first fiber coupler (8), a hollow core photonic band gap type fiber (9) and a second fiber coupler (10); the standard optical fiber (7) is connected with a first optical fiber coupler (8), the first optical fiber coupler (8) is connected with a hollow-core photonic band gap type optical fiber (9), the hollow-core photonic band gap type optical fiber (9) is connected with a second optical fiber coupler (10), the second optical fiber coupler (10) is connected with the next section of standard optical fiber (7), and the next section of standard optical fiber (7) is connected with the next gas detection unit (6).
7. The natural gas pipeline leakage monitoring device according to claim 1, wherein the signal analysis unit comprises a photoelectric detector (11), a lock-in amplifier (12) and a data processing center (13), the standard optical fiber (7) is connected with the photoelectric detector (11) after extending out of the ground, the photoelectric detector (11) is connected with the lock-in amplifier (12), and the lock-in amplifier (12) is connected with the data processing center (13); the photoelectric detector (11) outputs corresponding electric signals according to the detected laser signal intensity, and the lock-in amplifier (12) is used for detecting second harmonic signals in the electric signals output by the photoelectric detector (11); the data processing center (13) is used for data processing and displaying, and comprises a display unit for displaying whether methane leakage exists or not, the methane leakage concentration and a calculation unit for calculating the leakage position according to the second harmonic signal response time.
8. The natural gas pipeline leakage monitoring device according to claim 6, wherein the hollow-core photonic band gap type optical fiber (9) is 1m long and has a plurality of air holes on one side.
9. A method for natural gas pipeline leakage monitoring using a natural gas pipeline leakage monitoring device according to any one of claims 1 to 8, comprising the steps of:
step 1: connecting the air pump (1) with the sensing pipeline (14), and opening the air pump (1) to convey the gas in the sensing pipeline (14) from left to right;
step 2: loading a combined modulation signal to a current controller 4, setting a temperature controller (5) to be 27-30 ℃, and controlling a distributed feedback laser (3) to output a laser beam;
and step 3: connecting the distributed feedback laser (3) to the bismuth-doped optical fiber power amplifier (2), and amplifying the output power of the distributed feedback laser (3) to 160-200 mW;
and 4, step 4: then, laser passing through the bismuth-doped optical fiber power amplifier (2) is emitted into the gas detection unit (6) through the standard optical fiber (7), so that laser beams of the distributed feedback laser (3) enter the hollow-core photonic band gap type optical fiber (9);
and 5: when the natural gas pipeline leaks, the sensing pipeline (14) collects the leaked methane gas into the sensing pipeline (14) and conveys the methane gas from left to right;
step 6: when leaked methane gas enters the hollow-core photonic band gap type optical fiber (9), according to the Lambert-beer law, the standard optical fiber (7) transmits laser beams of the distributed feedback laser 3 to be in contact with and absorbed by the methane gas in the hollow-core photonic band gap type optical fiber (9), the laser intensity is weakened, at the moment, the photoelectric detector (11) outputs corresponding electric signals according to the detected laser signal intensity, wherein a second harmonic term in the electric signals is in direct proportion to the concentration of the leaked gas, the phase-locked amplifier (12) detects a second harmonic signal in the electric signals output by the photoelectric detector (11), and the concentration of the leaked gas is determined according to the intensity of the second harmonic signal;
and 7: and finally, the data processing center (13) displays whether the second harmonic signal detected by the phase-locked amplifier (12) leaks or not, inverts the methane leakage concentration according to the amplitude of the second harmonic signal and calculates the leakage position according to the response time of the second harmonic signal.
10. The natural gas pipeline leakage monitoring method according to claim 9, wherein the modulation signal in step 2 includes a high-frequency sinusoidal signal with an amplitude of 800mV and 5kHz and a sawtooth scanning signal with a frequency of 10Hz, and the control distributed feedback laser (3) outputs a laser beam with a center wavelength of 1650nm, the power is 3-5mw, and the line width is less than 10 MHz.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210170692.9A CN114607944A (en) | 2022-02-24 | 2022-02-24 | Natural gas pipeline leakage monitoring device and method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210170692.9A CN114607944A (en) | 2022-02-24 | 2022-02-24 | Natural gas pipeline leakage monitoring device and method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114607944A true CN114607944A (en) | 2022-06-10 |
Family
ID=81858982
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210170692.9A Pending CN114607944A (en) | 2022-02-24 | 2022-02-24 | Natural gas pipeline leakage monitoring device and method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114607944A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116773098A (en) * | 2023-08-24 | 2023-09-19 | 山东冠卓重工科技有限公司 | Gas leakage detection equipment of loading and unloading arm rotary joint |
| CN118482347A (en) * | 2024-07-04 | 2024-08-13 | 山东恒光电子科技有限公司 | Methane leakage detection device and detection method |
Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1431269A (en) * | 1972-11-28 | 1976-04-07 | Amg Zzrbier Ltdbird T J | Detection of gas leakage |
| JP2007033049A (en) * | 2005-07-22 | 2007-02-08 | Tokyo Electric Power Co Inc:The | Multipoint optical detection system for gas concentration |
| CN201575308U (en) * | 2009-09-02 | 2010-09-08 | 胜利油田胜利工程设计咨询有限责任公司 | Tunnel open space natural gas leakage laser monitoring device |
| CN102997043A (en) * | 2011-09-14 | 2013-03-27 | 中国石油天然气集团公司 | Method and system for multiplexing/de-multiplexing natural gas pipe leakage optical fiber monitoring sensor |
| CN203604997U (en) * | 2013-12-10 | 2014-05-21 | 苏州苏净保护气氛有限公司 | Buried gas pipeline leakage monitoring and alarming system |
| CN105403373A (en) * | 2015-12-20 | 2016-03-16 | 安徽中科智泰光电测控科技有限公司 | Diffusion type natural gas station gas leakage laser online monitoring early warning apparatus |
| CN106290248A (en) * | 2016-10-08 | 2017-01-04 | 山东微感光电子有限公司 | Oil-gas mining and accumulating dangerous leakage gas optical fiber sensing system device |
| CN106895267A (en) * | 2015-12-21 | 2017-06-27 | 西安天衡计量仪表有限公司 | A kind of device for monitoring underground gas pipeline leakage |
| CN109000712A (en) * | 2018-05-24 | 2018-12-14 | 国网山东省电力公司济南供电公司 | Cable tunnel multi-parameter distributed fiber-optic sensor measuring device and measuring method |
| CN110376131A (en) * | 2019-08-05 | 2019-10-25 | 江苏禾吉新材料科技有限公司 | A kind of distribution many reference amounts fiber-optic fiber gas detection system and detection method |
| CN209540526U (en) * | 2018-09-30 | 2019-10-25 | 上海电器科学研究所（集团）有限公司 | A kind of underground pipe gallery natural gas cabin leakage monitoring system |
| CN209621401U (en) * | 2019-01-28 | 2019-11-12 | 长安大学 | A kind of early warning system based on thermo parameters method formula fiber-optic monitoring |
| CN110470625A (en) * | 2019-08-26 | 2019-11-19 | 中国计量大学 | A kind of concentration of methane gas detection device |
| CN210462475U (en) * | 2019-07-18 | 2020-05-05 | 中海石油气电集团有限责任公司 | Defeated natural gas of pipe trace leaks continuous monitoring device based on detecting tube |
| CN112033908A (en) * | 2020-07-30 | 2020-12-04 | 大连理工大学 | Single-light-source optical fiber photoacoustic gas sensing system and method |
| CN112129470A (en) * | 2019-06-24 | 2020-12-25 | 北京工业大学 | Pipeline micro-leakage monitoring simulation experiment system of underground comprehensive pipe gallery |
| CN113757570A (en) * | 2021-07-28 | 2021-12-07 | 北京市燃气集团有限责任公司 | Natural gas line methane leak testing device |
-
2022
- 2022-02-24 CN CN202210170692.9A patent/CN114607944A/en active Pending
Patent Citations (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1431269A (en) * | 1972-11-28 | 1976-04-07 | Amg Zzrbier Ltdbird T J | Detection of gas leakage |
| JP2007033049A (en) * | 2005-07-22 | 2007-02-08 | Tokyo Electric Power Co Inc:The | Multipoint optical detection system for gas concentration |
| CN201575308U (en) * | 2009-09-02 | 2010-09-08 | 胜利油田胜利工程设计咨询有限责任公司 | Tunnel open space natural gas leakage laser monitoring device |
| CN102997043A (en) * | 2011-09-14 | 2013-03-27 | 中国石油天然气集团公司 | Method and system for multiplexing/de-multiplexing natural gas pipe leakage optical fiber monitoring sensor |
| CN203604997U (en) * | 2013-12-10 | 2014-05-21 | 苏州苏净保护气氛有限公司 | Buried gas pipeline leakage monitoring and alarming system |
| CN105403373A (en) * | 2015-12-20 | 2016-03-16 | 安徽中科智泰光电测控科技有限公司 | Diffusion type natural gas station gas leakage laser online monitoring early warning apparatus |
| CN106895267A (en) * | 2015-12-21 | 2017-06-27 | 西安天衡计量仪表有限公司 | A kind of device for monitoring underground gas pipeline leakage |
| CN106290248A (en) * | 2016-10-08 | 2017-01-04 | 山东微感光电子有限公司 | Oil-gas mining and accumulating dangerous leakage gas optical fiber sensing system device |
| CN109000712A (en) * | 2018-05-24 | 2018-12-14 | 国网山东省电力公司济南供电公司 | Cable tunnel multi-parameter distributed fiber-optic sensor measuring device and measuring method |
| CN209540526U (en) * | 2018-09-30 | 2019-10-25 | 上海电器科学研究所（集团）有限公司 | A kind of underground pipe gallery natural gas cabin leakage monitoring system |
| CN209621401U (en) * | 2019-01-28 | 2019-11-12 | 长安大学 | A kind of early warning system based on thermo parameters method formula fiber-optic monitoring |
| CN112129470A (en) * | 2019-06-24 | 2020-12-25 | 北京工业大学 | Pipeline micro-leakage monitoring simulation experiment system of underground comprehensive pipe gallery |
| CN210462475U (en) * | 2019-07-18 | 2020-05-05 | 中海石油气电集团有限责任公司 | Defeated natural gas of pipe trace leaks continuous monitoring device based on detecting tube |
| CN110376131A (en) * | 2019-08-05 | 2019-10-25 | 江苏禾吉新材料科技有限公司 | A kind of distribution many reference amounts fiber-optic fiber gas detection system and detection method |
| CN110470625A (en) * | 2019-08-26 | 2019-11-19 | 中国计量大学 | A kind of concentration of methane gas detection device |
| CN112033908A (en) * | 2020-07-30 | 2020-12-04 | 大连理工大学 | Single-light-source optical fiber photoacoustic gas sensing system and method |
| CN113757570A (en) * | 2021-07-28 | 2021-12-07 | 北京市燃气集团有限责任公司 | Natural gas line methane leak testing device |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116773098A (en) * | 2023-08-24 | 2023-09-19 | 山东冠卓重工科技有限公司 | Gas leakage detection equipment of loading and unloading arm rotary joint |
| CN116773098B (en) * | 2023-08-24 | 2023-11-03 | 山东冠卓重工科技有限公司 | Gas leakage detection equipment of loading and unloading arm rotary joint |
| CN118482347A (en) * | 2024-07-04 | 2024-08-13 | 山东恒光电子科技有限公司 | Methane leakage detection device and detection method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114607944A (en) | Natural gas pipeline leakage monitoring device and method | |
| CN201654940U (en) | Aspiration gas detecting system | |
| US11823805B2 (en) | Acousto-optic leakage monitoring system for nuclear power plant main steam pipeline | |
| CN205746047U (en) | A kind of long-distance oil & gas pipeline safety monitoring system | |
| CN109186895B (en) | Distributed passive gas transmission pipeline leakage multi-parameter fusion early warning detection device and method | |
| CN102900955A (en) | Pipeline leakage on-line monitoring device and method based on f fiber temperature detection | |
| CN112576942A (en) | Real-time monitoring system for hydrogen leakage | |
| CN201184499Y (en) | Oil gas pipe leakage monitoring device | |
| CN108240557A (en) | Natural gas transmission pipeline leakage detection system | |
| CN203720081U (en) | Gas parameter multipoint sensing and measurement type light path structure for laser absorption spectroscopy | |
| CN103883353A (en) | Distribution laser gas purely passive warning and monitoring device | |
| CN101324446B (en) | Destabilization sensing localization method | |
| CN110702625A (en) | Coal mine spontaneous ignition prevention monitoring system based on optical fiber sensing and laser spectrum analysis | |
| CN213274636U (en) | Distributed optical fiber heat supply pipeline leakage detection early warning system | |
| CN104456091B (en) | Fiber-optic interferometer CO2 pipe leak detection device based on 3*3 couplers | |
| CN106678551A (en) | Leakage detecting system and method for high-pressure CO2 pipeline | |
| CN211477522U (en) | Leakage distributed optical fiber detection system for acidic medium conveying pipeline | |
| CN206818249U (en) | The monitoring system of subsoil drain | |
| JPH0443934A (en) | Leak detecting device | |
| CN202252868U (en) | Leakage point positioning system of leakage monitoring system of fiber optical sensing natural gas pipeline | |
| CN205428116U (en) | A fiber optic temperature sensing fire detection system for highway tunnel | |
| CN206819417U (en) | Cruising inspection system for intelligent piping lane | |
| CN205808916U (en) | Methane leakage detector with self-calibration device | |
| KR20160103667A (en) | a gas leak of mid infrared optical sensor for vehicle mounted | |
| CN205484032U (en) | Methane leak detection system that can fix a position |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |