CN102997053B - A kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage - Google Patents
A kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage Download PDFInfo
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Abstract
The present invention is a kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage.It comprises light path system and circuit two parts; Pipeline body is installed a Fibre Optical Sensor unit at a certain distance, multiple Fibre Optical Sensor unit forms a Fibre Optical Sensor group, each Fibre Optical Sensor group optical fiber connects after a beam splitter being serially connected in optical fiber to the light source of receiving end and photodetector, photodetector exports and connects the Signal acquiring and processing module comprising leakage signal identification and state event location function, and described Signal acquiring and processing module comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface; Signal acquiring and processing module exports and connects microcomputer.Its sensitivity and accuracy is high, false alarm rate is low, be not subject to such environmental effects.
Description
Technical field
The present invention is a kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage, relates to the measurement of mechanical vibration, the measurement of impact and piping system technical field.
Background technology
At present, the pipeline overall length built up in the world reaches 2,500,000 kilometers, and having exceeded railway total kilometrage becomes world energy sources prevailing traffic mode, and the oil product of developed country and oil producing area, the Middle East transports and all realizes channelization.China's pipeline have also been obtained very fast development in recent years, overall length is also more than 70,000 kilometers, begun to take shape across thing, stretched from the north to the south, covered the whole nation, be communicated with the large general layout of overseas energy pipe network, pipeline transportation becomes the major way of the allotment conveying of the strategic energy such as oil gas.
Pipeline, due to extensively cross-regional, by reasons such as disaster, third party's breakage in installations, result in more pipe leakage accident and occurs.External pipe safety situation also allows of no optimist very much, and natural gas line big bang occurs San Bruno city on September 9th, 2010 of the U.S., explodes and to cause long 51 meters a, hollow place of wide 9 meters on road surface.The pipeline of one segment length about 8 meters, diameter 76 centimetres is exploded heaven, and fly out about 30 meters far away, and cause large-range fire disaster, cause 4 people dead, 3 people are missing, and at least 52 people are injured, burnt area 4 hectares, and tens of houses are burnt.People's safety, environmental consciousness significantly promote in recent years, and the pipeline transportation safety problem as high risk industries is also more and more paid attention to.
Only have sound wave monitoring method comparatively effective for natural gas line leakage in current proven technique, but in order to improve the accuracy of locating real-time and the leak source of leakage monitoring, the layout density of large sensor must be added on pipeline, increase corresponding power supply, communication facilities simultaneously, cause system cost and installation and maintenance costly.
Along with the development of sensing technology is abroad as the companies such as U.S. CSI, ATMOSI, European TER have carried out the research of SCADA leakage monitoring system, Sensornet company also develops the leakage monitoring system based on distributed optical fiber temperature sensor, and portioned product has also applied for patent protection at home; The units such as domestic University Of Tianjin, Tsing-Hua University, China Renmin People's Liberation Army Office Support Engineering Academy also further investigate the leakage monitoring method of pipeline.
Patent CN200410020046.6 discloses a kind of distribution type fiber-optic method for monitoring leak from oil gas pipe based on principle of interference and monitoring device.This monitoring system requires to lay an optical cable at Near Pipelines side by side along pipeline, utilizes the optical fiber in optical cable to form a Fiber optic micro-vibration sensor.Patent CN200620119429, CN200610113044.0 are the pipeline leakage monitor based on Sagnac fibre optic interferometer, and patent CN200610072879.6 is a kind of pipeline leakage monitor based on distributed optical fiber acoustic sensing technology and method.
" sensor and micro-system " the 26th " the gas pipe line leakage detection method based on distributed fiberoptic sensor " of volume the 7th phase disclose a kind of gas pipe line leak detecting device based on distributed fiberoptic sensor and method, it is installing optical fibres sensor on the pipeline body with certain intervals, the vibration wave signal that continuous real-time monitoring is propagated along pipeline body, analyzing and processing is carried out to the vibration wave signal gathered, comprise type identification and vibration source location, wherein type identification is by differentiating whether it belongs to leak type to the extraction and analysis of vibration wave feature, propagate into the position of time delay in conjunction with the velocity of propagation determination vibration wave source place of vibration wave on pipeline body of adjacent several Fibre Optical Sensor according to vibration wave simultaneously, the light intensity signal that sensor exports realizes the determination of the position of leakage point after opto-electronic conversion.
CN1837674A discloses a kind of pipeline leakage testing device and method based on distributed optical fiber acoustic sensing technology.
US2006/0225507A1 discloses a kind of pipeline leakage testing device and method based on distributed fiberoptic sensor.
Above-mentioned technology all belongs to distributed optical fiber sensing monitoring method.But such technical monitoring is subject to the impact of the interference incident that pipeline occurs when leaking, have very high system false alarm rate, antijamming capability is poor.And be equally also that there is very high system false alarm rate as the pipe leakage vibration wave velocity of propagation Analytical system in distributed optical fiber sensing monitoring system, antijamming capability is poor.
Summary of the invention
The object of the invention is to invent the sensitivity of a kind of high sensitivity based on Fibre Optical Sensor quasi-distributed leakage vibration monitor system and accuracy is high, false alarm rate is low, be not subject to the system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage of such environmental effects.
The sensitivity existed in view of above-mentioned a few class Leak Detection, monitoring technology is low, false alarm rate is high, be subject to the problems such as such environmental effects, the present invention is by the natural gas line leakage system based on quasi-distributed optical fiber interference sensing technology, namely adopt high sensitivity sensing unit and in conjunction with time domain, the frequency domain character of incident of leakage, leakage vibration wave velocity of propagation measured.
This measuring vibration wave propagation velocity in case of natural gas pipeline leakage method is based upon on the basis of natural gas line leakage method of Fibre Optical Sensor; Use natural gas line leakage system, some known sensing unit points are selected to cause vibration by knocking the form simulation pipe leakage such as pipeline, according to the quantity of the duct section used in engineering construction and examination data, time delay estimation is carried out to the leakage signal propagating into two adjacent sensing units and realizes the mensuration to leaking vibration wave speed in conjunction with known duct length, accurately provide the distance of the adjacent sensing unit point of current test point distance two, this simulation test point position X is substituted into: X=L-[v × (t
n+2-t
n)]/2, instead to solve: v=2 (L-X)/(t
n+2-t
n), realize measuring the speed of vibration wave along pipe transmmision according to the signal propagation time of known sensing unit spacing distance and mensuration.In formula, L is the distance between two adjacent sensing unit points; X is the distance of distance first sensing unit point (distance starting point), and v leaks vibration velocity of wave propagation.
Utilize with the common communications optical fibre in optical cable of oil and gas pipes laying in one ditch respectively as sending and receiving Transmission Fibers, pipeline leakage optical fiber sensing probe is connected between transmitting-receiving Transmission Fibers by Optical multiplexing technology is parallel with one another, form light circuit, it is along the line that pipeline leakage optical fiber sensing probe is evenly laid in pipeline, and being formed can the optical fiber sensing system of monitoring pipe road acoustic vibration.Light source is utilized to scan each pipeline leakage optical fiber sensing probe, according to the distribution situation of pipeline leakage optical fiber sensing probe to the photoelectric conversion signal demodulation gathered, extraction, the vibration information realizing each pipeline leakage optical fiber sensing probe obtains, detect analysis conduit leakage optical fiber sensing probe signal and judged whether that pipeline leakage event occurs, detect that the time delay of arrival of signal realizes the mensuration of pipe leakage vibration wave velocity of propagation according to adjacent pipeline leakage optical fiber sensing probe.
This system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage melts based in the natural gas line leakage system of Fibre Optical Sensor.So this system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage is exactly the natural gas line leakage system based on Fibre Optical Sensor.
Formation based on the natural gas line leakage system of Fibre Optical Sensor is shown in Fig. 1, and it comprises light path system and circuit two parts; Pipeline body is installed a Fibre Optical Sensor unit at a certain distance, multiple Fibre Optical Sensor unit forms a Fibre Optical Sensor group, each Fibre Optical Sensor group optical fiber connects after a beam splitter being serially connected in optical fiber to the light source of receiving end and photodetector, photodetector exports and connects the Signal acquiring and processing module comprising leakage signal identification and state event location function, and described Signal acquiring and processing module comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface.Signal acquiring and processing module exports and connects microcomputer.Through the process of Signal acquiring and processing module, the sensor group signal mixed based on frequency division multiplexing mode achieves the demultiplexing of each sensor in sensor group, obtains original leakage vibration wave signal.
Laser is sent by light source, after transmission light path realizes beam splitting, part light is transferred to the Fibre Optical Sensor group be arranged on duct wall, the pickup of Fibre Optical Sensor group is after the leakage vibration signal and noise of pipe transmmision, the photodetector of system is again transmitted back to through transmission light path, carry out leakage signal demodulation and discriminance analysis by Signal acquiring and processing module, and the location of time delay estimation realization to leakage point is carried out to leakage signal.
The light path system (see Fig. 4) of this natural gas line leakage system mainly designs based on frequency division multiplexing principle, is made up of light path adapter, transmission cable and Fibre Optical Sensor unit three part; Light path adapter is made up of beam splitter and combiner device; Fibre Optical Sensor unit adopts Mach-Zehnder interferometer or Michelson interferometer; Each Fibre Optical Sensor connects a light path adapter by two optical fiber, and all light path adapters are connected in series successively, by the light path adapter welding system main frame nearest apart from receiving end.
First light path adapter is arrived after input optical fibre in the exploring laser light input transmission cable that laser instrument sends enters sensing unit group, two bundle laser are divided into: a branch ofly enter first Fibre Optical Sensor unit through input optical fibre by the beam splitter of this light path adapter, another light beam passes to next light path adapter through time delay optical fiber, two bundle laser are divided into again by the beam splitter in next light path adapter, a branch ofly enter second Fibre Optical Sensor unit, another Shu Zaijing Transmission Fibers is transferred to next light path adapter, by that analogy, until laser arrives last Fibre Optical Sensor unit, every 2-10 adjacent Fibre Optical Sensor is divided into one group, and in group, the interference signal of each Fibre Optical Sensor is by combiner device access passback optical fiber, transfers back to system receiving terminal, at last Fibre Optical Sensor unit of sensing unit group, laser no longer by light path adapter, directly enters Fibre Optical Sensor unit, and the light signal after each Fibre Optical Sensor unit, by the combiner device in respective corresponding light path adapter, close with the light signal passed below and restraint, finally reach the photoelectric conversion module of monitoring system through output optical fibre.
Wherein, light path adapter set beam splitter and combiner device; Input optical fibre and output optical fibre use two in same transmission cable different fibre cores; All light path adapters are together in series by transmission cable; The length of the launching fiber between two sensing units adjacent on pipeline and passback optical fiber is all greater than 1/2 of laser instrument coherent length, to prevent from, between sensing unit, signal cross-talk occurs.
Specifically link as shown in Figure 5 in described light path system between each optical device, it by light path adapter, transmission cable and Fibre Optical Sensor three part form, light path adapter is made up of beam splitter and combiner device, Fibre Optical Sensor adopts Mach-Zehnder interferometer or Michelson interferometer, the leak detection light that light source sends enters the beam splitter I 1 in light path adapter through Transmission Fibers I 5, this beam splitter I 1 adopts splitting ratio to be 24: 1, wherein ratio be 24 output light continue propagate along time delay optical fiber 4, until light path adapter 2, and the output light that export ratio is 1 enters first sensing unit 2 through connecting fiber, sensing unit 2 adopts Mach-Zehnder interferometer structure, in order to ensure that sensing unit has certain sensitivity and controls interferometer arm difference at 20m, this interferometer is wound on the elastic body of elastomeric material, elastic body is close to duct wall, employing protective cover is fixed, distance Accurate Measurement between each sensing unit, controls light source according to the light travel-time and exports, beam splitter 1 in light path adapter 2 adopts the splitting ratio of 23: 1, wherein ratio is that the output light continuation of 23 is along input optical fibre propagation until run into next light path adapter, and the output light that export ratio is 1 enters second sensing unit 2 through connecting fiber, this sensing unit adopts Mach-Zehnder interferometer structure equally and controls interferometer arm difference at 20m, be wound on the elastic body of elastomeric material, elastic body is close to duct wall and is fixed, when pipeline between first and second sensing unit 2 occurs to leak, leak the vibration wave caused to be picked up by two sensing units respectively along pipe transmmision through the regular hour, import system photoelectric conversion module into by Transmission Fibers 5, final system receives the mistiming of leakage signal according to sensing unit and can realize the location of leakage point in conjunction with vibration wave velocity of propagation in the duct,
First the light signal returned by monitoring light path enters in the photodetector of system, carry out opto-electronic conversion, entering signal acquisition processing module processes afterwards, its process is: first carry out signal condition through modulate circuit, then gather through A/D collector, then send into signal processing unit and carry out signal filtering and demodulation process, obtain original leakage vibration wave signal, finally Signal analysis and positioning analysis are carried out to leakage signal, and analysis result is shown in terminal, signal acquisition process module principle is as shown in Figure 6;
Described light source is a kind of special light source system comprising applicable multiplexing and modulation /demodulation, and the laser instrument adjustable by optical frequency and dedicated modulation signal generating module are formed (see Fig. 2); The D/A follower that laser instrument input connects in modulation signal generation module, D/A follower connects signal generator, and signal generator has frequency adjustment, amplitude adjusted and the sawtooth wave/selection of falling sawtooth wave input; Can be selected as sawtooth wave or the signal type of falling saw wave modulator by programming, adjustment signalization amplitude and frequency; Modulation signal acts on laser instrument, exports the laser that changes with modulation signal synchronous waveform of optical frequency, is input in sensing light path, realizes multiplexing, the signal carrier that forms multiple sensing unit of sensing unit;
Wherein laser instrument adopts the semiconductor laser that optical frequency can be modulated, and modulation signal acts on laser instrument Injection Current, realizes the modulation of optical frequency; Laser optical power 1-17mW, laser instrument coherent length is greater than all the sensors interferometer arm length difference, but be less than launching fiber and the delay fiber lengths sum on passback optical fiber between adjacent two interferometers, the requirement postponing optical fiber between sensor interferometer instrument arm difference and adjacent two sensor interferometer instrument can be met;
Wherein modulation signal generation module adopts digital form to realize, namely calculate according to wave mode, signal amplitude, frequency parameter the modulation signal segment obtaining one-period by digital form, then exported by digital-to-analog conversion (D/A) mode, the modulated-analog signal exported is connected on laser instrument, wherein can be selected as sawtooth wave or the signal type of falling saw wave modulator by parameter configuration, adjustable signalization amplitude, direct current biasing and frequency; The sawtooth wave that modulation signal generation module exports or the requirement of falling sawtooth signal amplitude are ± 5V to the maximum, and frequency is 200KHz to the maximum; Laser instrument after modulation exports the laser that optical frequency changes with modulation signal synchronous waveform, is input in sensing light path, can realize multiplexing, the signal carrier that forms multiple sensing unit of sensing unit;
Wherein modulation of source circuit as shown in Figure 3, and it is primarily of operational amplifier U7, Distributed Feedback Laser U8, operational amplifier U9 and 2 triode Q4, Q5 group; The 7 termination VDC of U7, connect again with the circuit of electric capacity C38 parallel connection after connecting with diode D8, electric capacity C41 after 6 terminating resistor R18, VDC is met after 6 terminating resistor R19, what meet diode D4, D5, D6, D7 again is connected in series to ground simultaneously, 4,7,8,9,10 end ground connection, 3 ends are ground connection after resistance R17,2 ends and the end meeting U8; 1, the 14 end ground connection of U8,12 ends through electric capacity C34 ground connection, 5,11 termination VDC, 4 termination PDne, 6 termination TEC+, 3 ends connect the collector of triode Q4 after choking coil L 3 connects with resistance R20, and 3 ends connect the collector of triode Q5 after choking coil L3 connects with resistance R21 simultaneously; Between 1,2 ends of U9 after parallel resistance R22 and electric capacity C39 by 1 terminating resistor R25 to 6 ends, Pdne connecting resistance R30 again resistance in series R27 connects 3 ends of U9, the resistance R30 simultaneously meeting Pdne and potentiometer hinder ground connection of connecting after R31, resistance R32, electric capacity C43 three parallel connection, 5 ends meet VREF through resistance R24, and 7 ends meet electric capacity C45 to ground through resistance R28 and 8 ends altogether through resistance R26; Pick out the base stage through diode D11, D12 to Q4 from the upper end of electric capacity C45, base stage meets electric capacity C44 to ground simultaneously, and connect with also arriving with resistance R29 through diode D10, the base stage of Q4 connects the base stage of Q5 simultaneously, and the grounded emitter of Q4, Q5;
The formation of described Signal acquiring and processing module is shown in Fig. 6, and it comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface;
Wherein signal conditioner circuit as shown in Figure 7, and it forms primarily of operational amplifier U14, photoelectric diode U15; 1,5,8 ends of U15 are unsettled, 3,4 end ground connection, and 2 ends connect 6 ends after resistance R39, both electric capacity C60 parallel connection, and 6 ends connect 3 ends of U14 through resistance R43,8 ends of 7 termination U14; The 4 end ground connection of U14,5 ends are unsettled, and 6,7 ends meet AD_VINI altogether, 1 termination AD_OUT mouth, 2 ends through resistance R42 ground connection, the indirect resistance R40 of 1,2 ends, the parallel connection of both electric capacity C59;
The present invention is pipeline leakage monitor and method based on leaking vibration quasi-distributed optical fiber sensing, using the Fibre Optical Sensor without the need to powering as the pick device of leakage signal, the optical fiber laid with ditch with pipeline and Optical multiplexing technology is utilized to realize the signal long-distance transmissions of optical fibre vibration sensor, solve electric transducer to power and the difficult problem of telecommunication, can laying optical fiber vibrating sensing unit comparatively thick and fast, many sensing units are combined and are carried out time delay estimation, improve measuring vibration wave propagation velocity in case of natural gas pipeline leakage precision.
Accompanying drawing explanation
Fig. 1 Fibre Optical Sensor system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage schematic diagram
The modulation principle figure of Fig. 2 optical frequency adjustable type light source
Fig. 3 modulation of source circuit diagram
Fig. 4 monitoring system of fiber optical sensing natural gas pipeline light path system
Fig. 5 light path adapter structure and transmission index path
Fig. 6 Signal acquiring and processing function structure chart
Signal conditioning circuit figure in Fig. 7 Signal acquiring and processing module
Embodiment
In conjunction with the accompanying drawings and embodiments the present invention is further described, but should limit the scope of the invention with this.
Embodiment. the formation of the natural gas line leakage system of the Fibre Optical Sensor that this example is used is shown in Fig. 1, and it comprises light path system and circuit two parts; Pipeline body is installed a Fibre Optical Sensor unit at a certain distance, multiple Fibre Optical Sensor unit forms a Fibre Optical Sensor group, each Fibre Optical Sensor group optical fiber connects after a beam splitter being serially connected in optical fiber to the light source of receiving end and photodetector, photodetector exports and connects the Signal acquiring and processing module comprising leakage signal identification and state event location function, and described Signal acquiring and processing module comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface.Signal acquiring and processing module exports and connects microcomputer.Through the process of Signal acquiring and processing module, the sensor group signal mixed based on frequency division multiplexing mode achieves the demultiplexing of each sensor in sensor group, obtains original leakage vibration wave signal.
This example on pipeline body at a certain distance as 5km installs a Fibre Optical Sensor, 3 Fibre Optical Sensors form a Fibre Optical Sensor group, light source and the photodetector of receiving end received by each Fibre Optical Sensor group optical fiber, photodetector exports and connects the Signal acquiring and processing module comprising leakage signal recognition device and state event location device, and Signal acquiring and processing module exports and connects microcomputer.
The light path system (see Fig. 4) of this example designs based on frequency division multiplexing principle, and each Fibre Optical Sensor connects a light path adapter by two optical fiber, and all light path adapters are connected in series successively, by the light path adapter welding system main frame nearest apart from receiving end; Concrete optical routing light path adapter, transmission cable and Fibre Optical Sensor unit three part are formed; Light path adapter is made up of beam splitter and combiner device; Fibre Optical Sensor unit adopts Mach-Zehnder interferometer or Michelson interferometer.
Specifically link as shown in Figure 5 in described light path system between each optical device, the leak detection light that light source sends enters the beam splitter I 1 in light path adapter through Transmission Fibers I 5, this beam splitter I 1 adopts splitting ratio to be 24: 1, wherein ratio be 24 output light continue propagate along time delay optical fiber 4, until light path adapter 2, and the output light that export ratio is 1 enters first sensing unit 2 through connecting fiber, sensing unit 2 adopts Mach-Zehnder interferometer structure, in order to ensure that sensing unit has certain sensitivity and controls interferometer arm difference at 20m, this interferometer is wound on the elastic body of elastomeric material, elastic body is close to duct wall, employing protective cover is fixed, distance Accurate Measurement between each sensing unit, controls light source according to the light travel-time and exports, beam splitter 1 in light path adapter 2 adopts the splitting ratio of 23: 1, wherein ratio is that the output light continuation of 23 is along input optical fibre propagation until run into next light path adapter, and the output light that export ratio is 1 enters second sensing unit 2 through connecting fiber, this sensing unit adopts Mach-Zehnder interferometer structure equally and controls interferometer arm difference at 20m, be wound on the elastic body of elastomeric material, elastic body is close to duct wall and is fixed, when pipeline between first and second sensing unit 2 occurs to leak, leak the vibration wave caused to be picked up by two sensing units respectively along pipe transmmision through the regular hour, import system photoelectric conversion module into by Transmission Fibers 5, final system receives the mistiming of leakage signal according to sensing unit and can realize the location of leakage point in conjunction with vibration wave velocity of propagation in the duct,
Described light source is a kind of special light source system comprising applicable multiplexing and modulation /demodulation, and the laser instrument adjustable by optical frequency and dedicated modulation signal generating module are formed (see Fig. 2); Laser instrument exports the D/A follower connect in modulation signal generation module, and D/A follower connects signal generator, and signal generator has frequency adjustment, amplitude adjusted and the sawtooth wave/selection of falling sawtooth wave input; Can be selected as sawtooth wave or the signal type of falling saw wave modulator by programming, adjustment signalization amplitude and frequency; Modulation signal acts on laser instrument, exports the laser that changes with modulation signal synchronous waveform of optical frequency, is input in sensing light path, realizes multiplexing, the signal carrier that forms multiple sensing unit of sensing unit;
Wherein modulation of source circuit as shown in Figure 3, and it is primarily of operational amplifier U7, Distributed Feedback Laser U8, operational amplifier U9 and 2 triode Q4, Q5 group; The 7 termination VDC of U7, connect again with the circuit of electric capacity C38 parallel connection after connecting with diode D8, electric capacity C41 after 6 terminating resistor R18, VDC is met after 6 terminating resistor R19, what meet diode D4, D5, D6, D7 again is connected in series to ground simultaneously, 4,7,8,9,10 end ground connection, 3 ends are ground connection after resistance R17,2 ends and the end meeting U8; 1, the 14 end ground connection of U8,12 ends through electric capacity C34 ground connection, 5,11 termination VDC, 4 termination PDne, 6 termination TEC+, 3 ends connect the collector of triode Q4 after choking coil L3 connects with resistance R20, and 3 ends connect the collector of triode Q5 after choking coil L3 connects with resistance R21 simultaneously; Between 1,2 ends of U9 after parallel resistance R22 and electric capacity C39 by 1 terminating resistor R25 to 6 ends, Pdne connecting resistance R30 again resistance in series R27 connects 3 ends of U9, the resistance R30 simultaneously meeting Pdne and potentiometer hinder ground connection of connecting after R31, resistance R32, electric capacity C43 three parallel connection, 5 ends meet VREF through resistance R24, and 7 ends meet electric capacity C45 to ground through resistance R28 and 8 ends altogether through resistance R26; Pick out the base stage through diode D11, D12 to Q4 from the upper end of electric capacity C45, base stage meets electric capacity C44 to ground simultaneously, and connect with also arriving with resistance R29 through diode D10, the base stage of Q4 connects the base stage of Q5 simultaneously, and the grounded emitter of Q4, Q5;
Wherein:
Operational amplifier U7 selects AD623;
Laser instrument U8 selects internal modulation semiconductor light sources;
Operational amplifier U9 selects AD8572;
Triode Q4, Q5 select NPN9014;
The formation of described Signal acquiring and processing module is shown in Fig. 6, and it comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface;
Wherein signal conditioner circuit as shown in Figure 7, and it forms primarily of operational amplifier U14, photoelectric diode U15; 1,5,8 ends of U15 are unsettled, 3,4 end ground connection, and 2 ends connect 6 ends after resistance R39, both electric capacity C60 parallel connection, and 6 ends connect 3 ends of U14 through resistance R43,8 ends of 7 termination U14; The 4 end ground connection of U14,5 ends are unsettled, and 6,7 ends meet AD_VINI altogether, 1 termination AD_OUT mouth, 2 ends through resistance R42 ground connection, the indirect resistance R40 of 1,2 ends, the parallel connection of both electric capacity C59;
Wherein:
Operational amplifier U14 selects AD8572;
Photoelectric diode U15 selects OPA380AID;
Light source adopts the narrow cable and wide optical fiber laser of 100kHZ live width, laser instrument exports and connects beam splitter 1, beam splitter 1 adopts splitting ratio to be 24: 1, wherein ratio is that the output resume of 24 is along transmission paths until run into beam splitter 2, beam splitter 1 export ratio be 1 output terminal enter sensing unit 1 through connecting fiber, sensing unit 1 adopts Mach-Zehnder interferometer structure, in order to ensure that sensing unit has certain sensitivity and controls interferometer arm difference at 20m, this interferometer is wound on the elastic body of elastomeric material, and elastic body is close to duct wall and is fixed.Beam splitter 2 adopts the splitting ratio of 23: 1, wherein ratio is that the output resume of 23 is along transmission paths until run into next beam splitter 3, beam splitter 2 export ratio be 1 output terminal enter sensing unit 2 through connecting fiber, sensing unit 2 adopts Mach-Zehnder interferometer structure equally and controls interferometer arm difference at 20m, be wound on the elastic body of elastomeric material, elastic body is close to duct wall and is fixed.When pipeline between sensing unit 1 and sensing unit 2 occurs to leak, leak the vibration wave caused to be picked up by sensing unit 1 and 2 respectively through the regular hour along pipe transmmision, receive the mistiming of leakage signal according to sensing unit 1 and 2 and the location of leakage point can be realized in conjunction with vibration wave velocity of propagation in the duct.
Along duct orientation being arranged multiple sensing point, the distance Accurate Measurement between each sensing unit, controls light source according to the light travel-time and exports.
When pipeline between sensing unit n and sensing unit n+1 occurs to leak, leak the vibration wave caused to be picked up by sensing unit n-1, n, n+1 and n+2 respectively along pipe transmmision through the regular hour, receive the mistiming of leakage signal according to adjacent multiple sensing unit, just can measure vibration wave velocity of propagation in the duct.
Use this system, some known sensing unit points are selected to cause vibration by knocking the form simulation pipe leakage such as pipeline, according to the quantity of the duct section used in engineering construction and examination data, time delay estimation is carried out to the leakage signal propagating into two adjacent sensing units and realizes the mensuration to leaking vibration wave speed in conjunction with known duct length, accurately provide the distance of the adjacent sensing unit point of current test point distance two, this simulation test point position X is substituted into: X=L-[v × (t
n+2-t
n)]/2, instead to solve: v=2 (L-X)/(t
n+2-t
n), realize measuring the speed v of vibration wave along pipe transmmision according to the signal propagation time of known sensing unit spacing distance and mensuration.In formula, L is the distance between two adjacent sensing unit points; X is the distance of distance first sensing unit point (distance starting point), and v leaks vibration velocity of wave propagation.
This example is through test of many times, the monitoring to any disturbance behavior along pipe transmmision not only can be realized by installation leakage vibration sensing interfere type sensing unit on duct wall, through can realize the mensuration to vibration wave propagation velocity in case of natural gas pipeline leakage to signal analysis and processing and Intelligent Recognition, and system sensitivity is high, accuracy is high, false alarm rate is low, be not subject to such environmental effects.
Claims (4)
1. a system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage, it comprises light path system and circuit two parts; Pipeline body is installed a Fibre Optical Sensor unit at a certain distance, multiple Fibre Optical Sensor unit forms a Fibre Optical Sensor group, each Fibre Optical Sensor group optical fiber connects after a beam splitter being serially connected in optical fiber to the light source of receiving end and photodetector, photodetector exports and connects the Signal acquiring and processing module comprising leakage signal identification and state event location function, and described Signal acquiring and processing module comprises signal conditioner, signal picker, processing unit, terminal demonstration and external interface; Connect signal conditioner output serial connection signal picker and the processing unit successively that photodetector exports, processing unit exports terminal demonstration and external interface; Signal acquiring and processing module exports and connects microcomputer;
Laser is sent by light source, after transmission light path realizes beam splitting, fraction of laser light is transferred to the Fibre Optical Sensor group be arranged on duct wall, the pickup of Fibre Optical Sensor group is after the leakage vibration signal and noise of pipe transmmision, the photodetector of system is again transmitted back to through transmission light path, carry out the demodulation of leakage vibration signal and discriminance analysis by Signal acquiring and processing module, and carry out the location of time delay estimation realization to leakage point to leaking vibration signal;
Described light source is a kind of special light source system comprising applicable multiplexing and modulation /demodulation, and the laser instrument adjustable by optical frequency and dedicated modulation signal generating module are formed;
Described light path system is based on frequency division multiplexing principle, is made up of light path adapter, transmission cable and Fibre Optical Sensor unit three part; Light path adapter is made up of beam splitter and combiner device; Fibre Optical Sensor unit adopts Mach-Zehnder interferometer or Michelson interferometer; Each Fibre Optical Sensor connects a light path adapter by two optical fiber, and all light path adapters are connected in series successively, by the light path adapter welding system main frame nearest apart from receiving end;
It is characterized in that the light path system exploring laser light input optical fibre inputted in transmission cable that specifically laser instrument sends arrives first light path adapter after entering Fibre Optical Sensor group, two bundle laser are divided into: a branch ofly enter first Fibre Optical Sensor unit through input optical fibre by the beam splitter of this light path adapter, another light beam passes to next light path adapter through time delay optical fiber, two bundle laser are divided into again by the beam splitter in next light path adapter, a branch ofly enter second Fibre Optical Sensor unit, another Shu Zaijing Transmission Fibers is transferred to next light path adapter, by that analogy, until laser arrives last Fibre Optical Sensor unit, every 2-10 adjacent Fibre Optical Sensor is divided into one group, and in group, the interference signal of each Fibre Optical Sensor is by combiner device access passback optical fiber, transfers back to system receiving terminal, at last Fibre Optical Sensor unit of Fibre Optical Sensor group, laser no longer by light path adapter, directly enters Fibre Optical Sensor unit, and the light signal after each Fibre Optical Sensor unit, by the combiner device in respective corresponding light path adapter, close with the light signal passed below and restraint, finally reach the photoelectric conversion module of monitoring system through output optical fibre,
The set of described light path adapter beam splitter and combiner device; Input optical fibre and output optical fibre use two in same transmission cable different fibre cores; All light path adapters are together in series by transmission cable; The length of the launching fiber between two sensing units adjacent on pipeline and passback optical fiber is all greater than 1/2 of laser instrument coherent length.
2. a kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage according to claim 1, it is characterized in that the concrete connection in described light path system between each optical device is: the laser that light source sends enters the beam splitter (1) in light path adapter through Transmission Fibers (5), this beam splitter (1) adopts splitting ratio to be 24:1, wherein ratio be 24 output light continue propagate along time delay optical fiber (4), until run into next light path adapter (2), beam splitter (1) in next light path adapter (2) adopts the splitting ratio of 23:1, wherein ratio is that the output light continuation of 23 is along input optical fibre propagation until run into next light path adapter, and the output light that export ratio is 1 enters second sensing unit (2) through connecting fiber, this sensing unit adopts Mach-Zehnder interferometer structure equally and controls interferometer arm difference at 20m, be wound on the elastic body of elastomeric material, elastic body is close to duct wall and is fixed.
3. a kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage according to claim 1, is characterized in that described dedicated modulation signal generating module is primarily of operational amplifier U7, Distributed Feedback Laser U8, operational amplifier U9 and 2 triode Q4, Q5 composition; The 7 termination VDC of U7, connect again with the circuit of electric capacity C38 parallel connection after connecting with diode D8, electric capacity C41 after 6 terminating resistor R18, VDC is met after 5 terminating resistor R19, what meet diode D4, D5, D6, D7 again is connected in series to ground simultaneously, 4,7,8,9,10 end ground connection, 3 ends are ground connection after resistance R17,2 ends of 2 termination U8; 1, the 14 end ground connection of U8,12 ends through electric capacity C34 ground connection, 5,11 termination VDC, 4 termination PDne, 6 termination TEC+, 3 ends connect the collector of triode Q4 after choking coil L3 connects with resistance R20, and 3 ends connect the collector of triode Q5 after choking coil L3 connects with resistance R21 simultaneously; Between 1,2 ends of U9 after parallel resistance R22 and electric capacity C39 by 1 terminating resistor R25 to 6 ends, PDne connecting resistance R30 again resistance in series R27 connects 3 ends of U9, the resistance R30 simultaneously meeting PDne and potentiometer hinder ground connection of connecting after R31, resistance R32, electric capacity C43 three parallel connection, 5 ends meet VREF through resistance R24, and 7 ends meet electric capacity C45 to ground through resistance R28 and 8 ends altogether through resistance R26; Pick out the base stage through diode D11, D12 to Q4 from the upper end of electric capacity C45, base stage meets electric capacity C44 to ground simultaneously, and connect with also arriving with resistance R29 through diode D10, the base stage of Q4 connects the base stage of Q5 simultaneously, and the grounded emitter of Q4, Q5.
4. a kind of system for measuring vibration wave propagation velocity in case of natural gas pipeline leakage according to claim 1, is characterized in that described signal conditioner circuit forms primarily of operational amplifier U14, photoelectric diode U15; 1,5,8 ends of U15 are unsettled, 3,4 end ground connection, and 2 ends connect 6 ends after resistance R39, both electric capacity C60 parallel connection, and 6 ends connect 3 ends of U14 through resistance R43,8 ends of 7 termination U14; The 4 end ground connection of U14,5 ends are unsettled, and 6,7 ends meet AD_VINI altogether, 1 termination AD_OUT mouth, 2 ends through resistance R42 ground connection, the indirect resistance R40 of 1,2 ends, the parallel connection of both electric capacity C59.
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| CN102997059B (en) * | 2011-09-14 | 2014-08-06 | 中国石油天然气集团公司 | Method and system for measuring propagation speed of natural gas pipe leakage vibration wave |
| CN104456091B (en) * | 2014-11-13 | 2017-02-15 | 中国计量学院 | Fiber-optic interferometer CO2 pipe leak detection device based on 3*3 couplers |
| CN106678553B (en) * | 2017-03-17 | 2019-02-22 | 中国石油大学(华东) | A kind of calculation method leaking dynamic pressure wave spread speed in gas in pipe |
| CN107270133A (en) * | 2017-05-25 | 2017-10-20 | 湖北省郢声机电科技有限责任公司 | A kind of pipeline fluid leakage positioner and its application method |
| CN108278496A (en) * | 2018-01-23 | 2018-07-13 | 常州大学 | Condenser type fuel gas pipeline leakage new detecting method |
| CN112014368A (en) * | 2020-08-24 | 2020-12-01 | 安徽思环科技有限公司 | Novel light path system for water quality three-dimensional fluorescence monitoring system |
| CN113804650A (en) * | 2021-09-18 | 2021-12-17 | 中国特种设备检测研究院 | Monitoring device and monitoring method |
| CN117307989B (en) * | 2023-11-30 | 2024-03-08 | 山东省科学院激光研究所 | Optical fiber pipeline leakage detection system and method |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060225507A1 (en) * | 2003-01-13 | 2006-10-12 | Paulson Peter O | Pipeline monitoring system |
| CN101266024A (en) * | 2008-05-09 | 2008-09-17 | 于晋龙 | Distributed optical fibre oil gas conveying pipeline early early-warning system based on polarization detection |
| CN201191221Y (en) * | 2008-05-09 | 2009-02-04 | 东南大学 | Disturbance signal determination module of distributed optical fiber vibration sensor system |
| CN201413557Y (en) * | 2009-05-31 | 2010-02-24 | 中国石油天然气管道局 | Optical path multiplexing system of regional anti-intrusion system based on fiber optic interferometers |
| CN202252871U (en) * | 2011-09-14 | 2012-05-30 | 中国石油天然气集团公司 | System for measuring vibration wave propagation velocity in case of natural gas pipeline leakage |
| CN102997059A (en) * | 2011-09-14 | 2013-03-27 | 中国石油天然气集团公司 | Method and system for measuring propagation speed of natural gas pipe leakage vibration wave |
-
2011
- 2011-09-14 CN CN201110272063.9A patent/CN102997053B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20060225507A1 (en) * | 2003-01-13 | 2006-10-12 | Paulson Peter O | Pipeline monitoring system |
| CN101266024A (en) * | 2008-05-09 | 2008-09-17 | 于晋龙 | Distributed optical fibre oil gas conveying pipeline early early-warning system based on polarization detection |
| CN201191221Y (en) * | 2008-05-09 | 2009-02-04 | 东南大学 | Disturbance signal determination module of distributed optical fiber vibration sensor system |
| CN201413557Y (en) * | 2009-05-31 | 2010-02-24 | 中国石油天然气管道局 | Optical path multiplexing system of regional anti-intrusion system based on fiber optic interferometers |
| CN202252871U (en) * | 2011-09-14 | 2012-05-30 | 中国石油天然气集团公司 | System for measuring vibration wave propagation velocity in case of natural gas pipeline leakage |
| CN102997059A (en) * | 2011-09-14 | 2013-03-27 | 中国石油天然气集团公司 | Method and system for measuring propagation speed of natural gas pipe leakage vibration wave |
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Effective date of registration: 20170301 Address after: 100007 Dongcheng District, Dongzhimen, China, North Street, No. 9 Oil Mansion, No. Patentee after: China National Petroleum Corporation Patentee after: China Petroleum Pipeline Bureau Engineering Co., Ltd. Address before: 100007 Dongcheng District, Dongzhimen, China, North Street, No. 9 Oil Mansion, No. Patentee before: China National Petroleum Corporation Patentee before: China Petroleum and Natural Gas Pipeline Bureau |