CN102352964A - Thermal fluid leak detecting and positioning system based on integrated fiber grating cluster - Google Patents
Thermal fluid leak detecting and positioning system based on integrated fiber grating cluster Download PDFInfo
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- CN102352964A CN102352964A CN2011103028749A CN201110302874A CN102352964A CN 102352964 A CN102352964 A CN 102352964A CN 2011103028749 A CN2011103028749 A CN 2011103028749A CN 201110302874 A CN201110302874 A CN 201110302874A CN 102352964 A CN102352964 A CN 102352964A
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Abstract
The invention provides a thermal fluid leak detecting and positioning system based on integrated fiber grating cluster and belongs to the technical field of thermal fluid pipeline leak detection. The system comprises a C-waveband continuous broadband light source, an integrated fiber grating cluster, a microcontroller and the like, and is characterized in that an optical modulator is arranged behind the C-waveband continuous broadband light source, the port a of a circulator is connected with the rear of the optical modulator, the port b of the circulator is connected with the input end of an optical switch, the output end of the optical switch is connected with the integrated fiber grating cluster; the port c of the circulator is connected with a photoelectric detector, the photoelectric detector is connected to the input end of a filtering and shaping circuit, the output end of the filtering and shaping circuit is connected to an amplifying circuit, the output end of the amplifying circuit is connected to the input end of an analog-to-digital conversion circuit, the output end of the analog-to-digital conversion circuit is connected with the microcontroller through the IO (input output) port of the microcontroller so as to realize the processing on a obtained digital signal; and the optical modulator and the optical switch are respectively connected with the microcontroller through the IO port of the microcontroller so as to realize the synchronous control on the microcontroller. The system provided by the invention has the advantages of low cost and high detection accuracy.
Description
Technical field
The present invention relates to a kind of hot fluid leak detection and navigation system, belong to hot fluid pipeline leak detection technology field based on integrated fiber bragg grating bunch.
Background technique
On the whole, the oil transport pipeline leak hunting method mainly contains three types: tour, direct leak hunting method and software analysis method.
(1) inspection method
This is a kind of traditional leakage detection method; Mainly be personnel selection or trained animal (dog) along pipeline walking check piping attachment abnormal conditions, hear the smell that discharges in the pipeline, listening etc.; This method is directly accurate, but real-time is poor, the manpower of labor.
(2) direct leak hunting method
Use sonic transducer device, gas detecting instrument etc., as utilize the temperature variation of temperature sensor measurement leak, use multisensor cable along pipe laying.Sonic transducer is that fluid outflow pipeline can be sounded when leaking generation, and sound wave is propagated according to the speed of the physical property decision of pipeline inner fluid, and sonic transducer detects this wave sound and finds to leak.Like the acoustics leak detection system (wavealert) of houston, u.s.a sound system company (ASI) according to this principle development; Form by many groups sensor, decoder, wireless launcher etc.; Antenna elevates above the soil and control centre's contact, and the restriction of the examined scope of this method must be along a lot of sound transducers of piping erection.Gas detecting instrument then need use the portable gas sampler along pipe walking, and the gas that leaks is detected.
(3) software analysis method
Data such as the flow that its employing is provided by the SCADA system, pressure, temperature are leaked through the method detection of flow or variation in pressure, quality or volumetric balance, dynamic model and pressure spot analysis software.Offshore company pays much attention to the safe operation of oil transport pipeline, line leakage technology comparative maturity, and obtained using widely.Gone out the novel pipeline leak detection system that a kind of brand name is ATMOS Pine like Shell Co. Ltd through the long term studies Development and Production; ATMOS Pine is based on statistical analysis principle and designs; Utilize optimization analytic method (sequential probability-ratio test method) mensuration pipeline import and export flow and the overall behavior of pressure to change and leak, have advanced person's pattern identification function simultaneously concurrently to detect.This system can detect the leakage of 1.6kg/s and false alarm not take place.
Summary of the invention
In order to overcome defective and the deficiency that prior art exists, the present invention proposes a kind of hot fluid (particularly crude oil) leak detection and navigation system based on integrated fiber bragg grating bunch, aim to provide stable, lay convenient and leak detection and navigation system cheaply.
Technological scheme of the present invention realizes by following mode:
A kind of hot fluid leak detection and navigation system based on integrated optical fiber grating bunch; Comprise C-band continuous wide band light source, optical modulator, optical switch, circulator, photodetector, filtering shaping circuit, amplification circuit, analog to digital conversion circuit, integrated optical fiber grating bunch and single-chip microcomputer; It is characterized in that C-band continuous wide band light source back placement optical modulator; The optical modulator back connects a mouth of circulator; The b mouth of circulator connects the input end of optical switch, and the optical switch output terminal connects integrated optical fiber grating bunch; The c mouth of circulator connects photodetector; Photodetector is connected to the input end of filtering shaping circuit, the output terminal of filtering shaping circuit is connected to amplification circuit; The output terminal of amplification circuit is connected to the input end of analog to digital conversion circuit; The output terminal of analog to digital conversion circuit is connected with single-chip microcomputer through the IO of single-chip microcomputer mouth, with realization the gained digital signal is handled; Optical modulator is connected with single-chip microcomputer respectively through the IO of single-chip microcomputer mouth with optical switch, to realize that single-chip microcomputer carries out synchronization control to it.
Described optical modulator is shutter or chopper.
Described C-band continuous wide band light source is that operation wavelength is C-band zone, continuous radiative light source, like ASE (amplified spontaneous emission) light source of C-band.
Described photodetector is short photodiode of response time.
Described integrated optical fiber grating clustering architecture is following: it is to be made up of multifiber grating group; Wherein every fiber bragg grating group is that fiber bragg grating by different foveal reflex wavelength is in serial connected through connecting optical fiber, and each fiber bragg grating is with to be connected length of fiber equal; It is right that per two fiber bragg grating groups are formed the fiber bragg grating group, and two fiber bragg grating groups fiber bragg grating each other of fiber bragg grating group centering is with to be connected optical fiber interlaced; The fiber bragg grating group is pencil to arrangement; Each fiber bragg grating group is to end-to-end arrangement each other; Make fiber bragg grating in each road fiber bragg grating group be staggered mutually and do not coincide each other, constitute integrated optical fiber grating bunch with fiber bragg grating in other fiber bragg grating groups.
Fiber bragg grating group in the said integrated optical fiber grating bunch is right to being 5-600.
System of the present invention is in use in advance with bunch pipe laying along the conveying hot fluid of integrated optical fiber grating; Be affixed on the outside of pipe insulation layer; The continuous wide band light that C-band continuous wide band light source sends obtains photoderm through light modulator modulates; Make its repetition frequency identical with the switching frequency of optical switch; Get into circulator by a mouth of circulator, get into optical switch and integrated optical fiber grating bunch through the output of b mouth.Light by the optical grating reflection in the integrated optical fiber grating bunch returns is transported to the c mouth through the b oral instructions that optical switch returns circulator, gets into photodetector, converts optical signal into electrical signal (for pulse electrical signal) through photoelectric conversion.After pulse electrical signal is handled by filtering shaping circuit, amplification circuit; After the analog to digital conversion circuit conversion, data are sent in the single-chip microcomputer again; Then according to the noise threshold and other restrictions that obtain by single-chip microcomputer; Carry out data processing, judge the leakage whether hot fluid takes place and confirm leak location.Processing result can be transported to man-machine interface by single-chip microcomputer, realizes reporting to the police and demonstrating the position.
The concrete working principle of system of the present invention is following:
Under the control action of single-chip microcomputer, optical modulator, optical switch are kept synchronously, thereby guarantee that light pulse imports each road fiber bragg grating group of integrated optical fiber grating successively.Grating in each road fiber bragg grating group forms the pulse sequence that gets into photodetector through circulator with the light of reflected back corresponding wavelength.And when pipeline took place to leak, the temperature effect of integrated fiber bragg grating heated fluid changed, and then changes the light pulse sequence of its reflected back.Light pulse sequence is converted into electrical signal by photodetector, and electrical signal carries out data processing by analog to digital conversion circuit and single-chip microcomputer then through filter shape, amplification, and the parameter preset that provides through single-chip microcomputer has judged whether to take place the leakage of hot fluid.If leakage has taken place, poor according to the time of return of corresponding pulses again, can calculate the range difference of leakage place and light-incident end, and the position of light-incident end is set, just can confirm the particular location at temperature variation place.So realized detection, promptly realized leak detection and location hot fluid to the temperature variation place.
The working principle of single optical grating group is in the system of the present invention:
When hot fluid took place to leak, its leak point temperature exceeded several years even tens degree than other local temperature.And variation of temperature can change the wherein phase constant of fiber bragg grating, and then changes its centre wavelength.Selecting the light of suitable wave band to incide a segment length grows (being assumed to be 10m), is in the fiber bragg grating of centre wavelength with λ; The incident light medium wavelength is that the light of λ promptly is reflected back in the very little segment distance of incident ray grating end face, and the light of other wavelength components continues to propagate.When the temperature of follow-up certain point of fiber bragg grating change (situation when corresponding fluid is revealed); The fiber grating at this some place becomes λ '; Then wavelength is that the light of λ ' will be reflected, and new blip (pulse signal of locating like λ ' corresponding among Fig. 4) occurs.
Suppose to be furnished with in the every fiber bragg grating group fiber bragg grating of 8 different foveal reflex wavelength; The working portion that is fiber bragg grating is 10m; Connection length of fiber between each fiber bragg grating is 10m; Then when not taking place to reveal; Return 8 identical pulses of the time lag; Otherwise, just can conclude leakage to have occurred.
The working principle of integrated optical fiber grating bunch:
When light when optical switch incides m road fiber bragg grating group, can be at the very small distance scope internal reflection light echo of the incident end face of each section grating, thus obtain one time of the pulse signal shown in accompanying drawing 3.If revealing appears in (incident end face of non-grating) somewhere, leakage flow is known from experience the fiber bragg grating that makes corresponding points and is produced new pulse, shown in accompanying drawing 4; If leakage place is just at the incident end face place of a certain section grating; Then at the incident end face place with the light pulse of reflected back λ ' (wavelength after the change); Impregnable in the back grating place is with the light pulse of reflected back λ (wavelength that does not change), and its blip situation is also shown in accompanying drawing 4.So need come accurately to judge the position of leak point to this kind special circumstances through certain reasoning from logic.There is the situation of the corresponding same monitoring point of two grating end faces in fiber bragg grating group centering in the fiber bragg grating of native system bunch; If reveal at a certain grating end face; Then this two-way fiber bragg grating group all should obtain the pulse shown in the accompanying drawing 4, can judge that thus leakage place just is positioned at this grating end; If have only one road fiber bragg grating group to obtain the pulse shown in the accompanying drawing 4, and another rood can judge then that to the pulse shown in the accompanying drawing 3 this leakage place is positioned at the incident end face of non-grating.Can accurately judge the position of leak point thus.
As stated, just can get pulse signal and judge whether leakage has taken place through an optical fiber bunch reflected back.Because control circuit makes incident light, optical switch synchronous, the pulse signal that obtains with photodetector carries out the time contrast, just can confirm the particular location of revealing.
The present invention has following advantage:
Adopt integrated fiber bragg grating bunch to make sensor, carry out distributed detection; With temperature difference leak detection, the ingenious interference that variation of ambient temperature causes, the signal to noise ratio height removed; Measure the length change flexibly, when duct length to be detected is long, can adopt a plurality of these systems; Have wide range of applications, be suitable for the leak detection that multiple hot fluid transports.System cost of the present invention is low, and it is high to detect accuracy rate.
Description of drawings
Accompanying drawing 1 is structural representation of the present invention.
Wherein: 1, C-band continuous wide band light source; 2, optical modulator; 3, circulator; 4, optical switch; 5, single-chip microcomputer; 6, analog to digital conversion circuit; 7, photodetector; 8, integrated optical fiber grating bunch; 9, filtering shaping circuit; 10, amplification circuit.
Accompanying drawing 2 is integrated optical fiber grating clustering architecture schematic representation of the present invention.
Wherein: 11. fiber bragg grating groups are right, 12. fiber bragg grating groups, and 13. integrated optical fiber grating bunch access interface, 14. fiber bragg gratings, 15. connect optical fiber..By finding out in the fiber bragg grating of the present invention bunch the situation of arranging of grating on the fiber bragg grating group and every road fiber bragg grating group among the figure; White portion in the fiber bragg grating group of wherein every road is depicted as connection optical fiber, and the black part branch is depicted as fiber bragg grating (the key job part of promptly hunting leak and locating).
Fig. 3 does not scan the pulse signal that m road optical fiber obtains for there being when leakage.
Fig. 4 has when leakage to scan the pulse signal that m road optical fiber obtains.Wherein leakage place of the hot fluid pipeline that the pulse signal located of λ ' is corresponding.
Embodiment
The present invention is further illustrated below in conjunction with accompanying drawing and embodiment, but be not limited thereto.
Embodiment 1:
The embodiment of the invention 1 is shown in accompanying drawing 1-2; Comprise C-band continuous wide band light source 1, optical modulator 2, optical switch 4, circulator 3, photodetector 7, filtering shaping circuit 9, amplification circuit 10, analog to digital conversion circuit 6, integrated optical fiber grating bunches 8 and single-chip microcomputer 5; It is characterized in that C-band continuous wide band light source 1 back placement optical modulator 2; Optical modulator 2 back connect a mouth of circulator 3; The b mouth of circulator 3 connects the input end of optical switch 4, and optical switch 4 output terminals connect integrated optical fiber grating bunches 8; The c mouth of circulator 3 connects photodetector 7; Photodetector 7 is connected to the input end of filtering shaping circuit 9, the output terminal of filtering shaping circuit 9 is connected to amplification circuit 10; The output terminal of amplification circuit 10 is connected to the input end of analog to digital conversion circuit 6; The output terminal of analog to digital conversion circuit 6 is connected with single-chip microcomputer 5 through the IO of single-chip microcomputer 5 mouth, with realization the gained digital signal is handled; Optical modulator 2 is connected with single-chip microcomputer 5 respectively through the IO of single-chip microcomputer 5 mouth with optical switch 4, to realize that single-chip microcomputer 5 carries out synchronization control to it.
Described optical modulator 2 is choppers.
Described C-band continuous wide band light source 1 is that operation wavelength is C-band zone, continuous radiative light source, the i.e. ASE of C-band (amplified spontaneous emission) light source.
Described photodetector 7 is short photodiodes of response time.
Described integrated optical fiber grating bunch 8 structures are following: it is to be made up of multifiber grating group 12; Wherein every fiber bragg grating group 12 is that fiber bragg grating 14 by different foveal reflex wavelength is in serial connected each fiber bragg grating 14 and the equal in length that is connected optical fiber 15 through connecting optical fiber 15; Per two fiber bragg grating groups 12 are formed the fiber bragg grating groups to 11, the fiber bragg grating group to two fiber bragg grating groups 12 fiber bragg grating 14 each other in 11 with to be connected optical fiber 15 interlaced; The fiber bragg grating group is pencil to 11 arrangements; Each fiber bragg grating group is to 11 end-to-end arrangements each other; Make fiber bragg grating 14 in each road fiber bragg grating group 12 be staggered mutually and do not coincide, constitute integrated optical fiber grating bunch with fiber bragg grating in other fiber bragg grating groups 12.
Fiber bragg grating group in the said integrated optical fiber grating bunch is to being 400 pairs.
Embodiment 2:
The embodiment of the invention 2 is as identical as described in the embodiment 1, and just optical modulator 2 is shutters; Fiber bragg grating group in the said integrated optical fiber grating bunch is to being 20 pairs.
Claims (6)
1. hot fluid leak detection and navigation system based on an integrated optical fiber grating bunch; Comprise C-band continuous wide band light source, optical modulator, optical switch, circulator, photodetector, filtering shaping circuit, amplification circuit, analog to digital conversion circuit, integrated optical fiber grating bunch and single-chip microcomputer; It is characterized in that C-band continuous wide band light source back placement optical modulator; The optical modulator back connects a mouth of circulator; The b mouth of circulator connects the input end of optical switch, and the optical switch output terminal connects integrated optical fiber grating bunch; The c mouth of circulator connects photodetector; Photodetector is connected to the input end of filtering shaping circuit, the output terminal of filtering shaping circuit is connected to amplification circuit; The output terminal of amplification circuit is connected to the input end of analog to digital conversion circuit; The output terminal of analog to digital conversion circuit is connected with single-chip microcomputer through the IO of single-chip microcomputer mouth, with realization the gained digital signal is handled; Optical modulator is connected with single-chip microcomputer respectively through the IO of single-chip microcomputer mouth with optical switch, to realize that single-chip microcomputer carries out synchronization control to it.
2. a kind of hot fluid leak detection and navigation system based on integrated optical fiber grating bunch as claimed in claim 1 is characterized in that described optical modulator is shutter or chopper.
3. a kind of hot fluid leak detection and navigation system based on integrated optical fiber grating bunch as claimed in claim 1 is characterized in that described C-band continuous wide band light source is that operation wavelength is C-band zone, continuous radiative light source, i.e. the ASE light source of C-band.
4. a kind of hot fluid leak detection and navigation system based on integrated optical fiber grating bunch as claimed in claim 1 is characterized in that described photodetector is short photodiode of response time.
5. a kind of hot fluid leak detection and navigation system as claimed in claim 1 based on integrated optical fiber grating bunch; It is characterized in that described integrated optical fiber grating clustering architecture is following: it is to be made up of multifiber grating group; Wherein every fiber bragg grating group is that fiber bragg grating by different foveal reflex wavelength is in serial connected through connecting optical fiber, and each fiber bragg grating is with to be connected length of fiber equal; It is right that per two fiber bragg grating groups are formed the fiber bragg grating group, and two fiber bragg grating groups fiber bragg grating each other of fiber bragg grating group centering is with to be connected optical fiber interlaced; The fiber bragg grating group is pencil to arrangement; Each fiber bragg grating group is to end-to-end arrangement each other; Make fiber bragg grating in each road fiber bragg grating group be staggered mutually and do not coincide each other, constitute integrated optical fiber grating bunch with fiber bragg grating in other fiber bragg grating groups.
6. a kind of hot fluid leak detection and navigation system as claimed in claim 5 based on integrated optical fiber grating bunch, it is characterized in that in the said integrated optical fiber grating bunch the fiber bragg grating group to for 5-600 right.
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| Application Number | Priority Date | Filing Date | Title |
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| CN 201110302874 CN102352964B (en) | 2011-10-09 | 2011-10-09 | Thermal fluid leak detecting and positioning system based on integrated fiber grating cluster |
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| CN 201110302874 CN102352964B (en) | 2011-10-09 | 2011-10-09 | Thermal fluid leak detecting and positioning system based on integrated fiber grating cluster |
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| CN102352964B CN102352964B (en) | 2013-04-10 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106015947A (en) * | 2016-05-11 | 2016-10-12 | 吉林省中科环宇智能科技有限公司 | Internet-based pipeline in-situ monitoring system |
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| CN1837674A (en) * | 2006-04-14 | 2006-09-27 | 北京工业大学 | Apparatus and method for monitoring pipeline leakage based on distributed optical fiber acoustic sensing technology |
| CN2842391Y (en) * | 2005-11-21 | 2006-11-29 | 天津爱天光电子科技有限公司 | Optical-fiber grating detector and its optical-fiber grating sensor |
| CN102176684A (en) * | 2011-03-23 | 2011-09-07 | 东南大学 | Distributed optical fiber sensor for simultaneously monitoring engineering structure entirety and local strain |
| CN202252874U (en) * | 2011-10-09 | 2012-05-30 | 山东大学 | Hot fluid leakage detection and location system based on integrated optical fiber and grating cluster |
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2011
- 2011-10-09 CN CN 201110302874 patent/CN102352964B/en not_active Expired - Fee Related
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1980001941A1 (en) * | 1979-03-13 | 1980-09-18 | Pi Kommunalproekt | Device for location of points of loss in a pipe-line |
| CN1363828A (en) * | 2002-02-08 | 2002-08-14 | 武汉理工大学 | Temp monitoring and alarming system with identity optical fibre raster |
| CN2842391Y (en) * | 2005-11-21 | 2006-11-29 | 天津爱天光电子科技有限公司 | Optical-fiber grating detector and its optical-fiber grating sensor |
| CN1837674A (en) * | 2006-04-14 | 2006-09-27 | 北京工业大学 | Apparatus and method for monitoring pipeline leakage based on distributed optical fiber acoustic sensing technology |
| CN102176684A (en) * | 2011-03-23 | 2011-09-07 | 东南大学 | Distributed optical fiber sensor for simultaneously monitoring engineering structure entirety and local strain |
| CN202252874U (en) * | 2011-10-09 | 2012-05-30 | 山东大学 | Hot fluid leakage detection and location system based on integrated optical fiber and grating cluster |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN106015947A (en) * | 2016-05-11 | 2016-10-12 | 吉林省中科环宇智能科技有限公司 | Internet-based pipeline in-situ monitoring system |
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