CN105987771A - Temperature monitoring method and system based on optical fiber - Google Patents

Temperature monitoring method and system based on optical fiber Download PDF

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Publication number
CN105987771A
CN105987771A CN201610512131.7A CN201610512131A CN105987771A CN 105987771 A CN105987771 A CN 105987771A CN 201610512131 A CN201610512131 A CN 201610512131A CN 105987771 A CN105987771 A CN 105987771A
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CN
China
Prior art keywords
light
temperature
signal
telecommunication
optical fiber
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CN201610512131.7A
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Chinese (zh)
Inventor
张强
刘博宇
聂鑫
刘本刚
李建彬
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深圳艾瑞斯通技术有限公司
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Priority to CN201610512131.7A priority Critical patent/CN105987771A/en
Publication of CN105987771A publication Critical patent/CN105987771A/en

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/32Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmission, scattering or fluorescence in optical fibres
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01KMEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/32Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmission, scattering or fluorescence in optical fibres
    • G01K2011/324Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmission, scattering or fluorescence in optical fibres using Raman scattering

Abstract

The invention discloses a temperature monitoring method and a system based on an optical fiber. The temperature monitoring method comprises steps: Raman scattering light returned by a measurement point of a sensing optical fiber is acquired; at least part of the Raman scattering light is splitted to obtain first frequency light and second frequency light; photoelectric conversion is respectively carried out on the first frequency light and the second frequency light, and first electric signals and second electric signals are obtained; and through a corresponding relationship between the first electric signals and the second electric signals and measurement temperature, the measurement temperature of the measurement point is obtained. Through the above mode, the cable temperature can be monitored conveniently and accurately, the structure is simple, the layout is convenient, high temperature can be resisted, and the monitoring cost can be effectively reduced.

Description

Temperature monitoring method based on optical fiber and system

Technical field

The present invention relates to technical field of optical fiber sensing, particularly relate to a kind of temperature based on optical fiber prison Survey method and system.

Background technology

The safety detection of buried cable is directly connected to perimeter security, can carry out body by many indexes Existing.Temperature monitoring is wherein to compare a crucial factor.

The most conventional cable temperature detecting system mainly has temperature-sensitive cable type temp measuring system and heat Quick resistance temperature system.Temperature sensing cable formula temp measuring system is by temperature sensing cable and cable parallelization, When cable temperature exceedes fixed temperature value, sensing cable is shorted, but this system can only be once Property use, it is impossible to a fairly large number of cable is detected, and system install and safeguard the most not Convenient, equipment is easier to damage, and can not carry out temperature and show, therefore, this system can not be entered Row fault forecast and temperature trend analysis can not be carried out.

Critesistor is temp measuring system, although can show temperature, but due to each of which Critesistor is required for independent wiring, wiring, and not only operation is complicated and critesistor is easily damaged, In addition its quantity itself is relatively big, and therefore, maintenance workload is huge, and cost is high.

Summary of the invention

The technical problem that present invention mainly solves is to provide a kind of temperature monitoring method based on optical fiber And system, it is possible to convenience, accurately cable temperature are monitored, and simple in construction, laying side Just, high temperature resistant, it is possible to effectively to reduce monitoring cost.

For solving above-mentioned technical problem, the technical scheme that the present invention uses is: provide a kind of base In the temperature monitoring method of optical fiber, described temperature monitoring method includes:

Obtain sensor fibre measures the Raman diffused light that point returns;

At least part of described Raman diffused light is carried out light splitting and obtains first frequency light and the second frequency Rate light;

Respectively described first frequency light and second frequency light are carried out opto-electronic conversion, obtain the first telecommunications Number and second signal of telecommunication;

Obtained by described first signal of telecommunication and second signal of telecommunication and the corresponding relation measured between temperature To the described measurement temperature measuring point.

Wherein, described by described first signal of telecommunication and second signal of telecommunication and measure between temperature right Also include after should being related to the step of the measurement temperature obtaining described measurement point:

Obtain measurement temperature and the actual temperature of reference optical fiber;Wherein, described reference optical fiber is arranged On the transmission path of described optical signal, the acquisition mode of the measurement temperature of described reference optical fiber and institute The acquisition mode stating the measurement temperature measuring point is identical;

With reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, by described measurement The measurement temperature of point obtains the described actual temperature measuring point.

It is wherein, described with reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, The step being obtained the described actual temperature measuring point by the described measurement temperature measuring point includes:

According to formula 1:Try to achieve the described actual temperature measuring point Degree T,

Wherein, described R (T) is the described measurement temperature measuring point, described R (T0) it is described reference light Fine measurement temperature, described T0For the actual temperature of described reference optical fiber, h is Planck's constant, c For the light velocity, μ is Boltzmann constant, and described k is Boltzmann constant, wherein, K=1.3806488 (13) × 10^-23J/K.

Wherein, described temperature checking method also includes:

Judge whether described measurement is sent out between the current actual temperature of point and the actual temperature that obtains before The raw change exceeding setting value;

The most then send the alarm that the described temperature measuring point changes.

Wherein, described first signal of telecommunication is the first magnitude of voltage, and described second point signal is the second voltage Value,

Described by described first signal of telecommunication and second signal of telecommunication and the corresponding pass measured between temperature System obtains the step of the described measurement temperature measuring point and specifically includes:

Described first frequency light is obtained respectively according to described first magnitude of voltage and the second magnitude of voltage First light intensity and the second light intensity of second frequency light;

The ratio of described first light intensity and described second light intensity is defined as the described test measuring point Temperature.

Wherein, respectively described first frequency light and second frequency light are carried out opto-electronic conversion described, After obtaining the step of first signal of telecommunication and second signal of telecommunication, described method also includes:

Described first signal of telecommunication and second signal of telecommunication are carried out Kalman filtering respectively.

Wherein, after the step measuring the Raman diffused light that point returns of described acquisition sensor fibre, Also include:

By transmission time and the biography of described Raman diffused light of the Raman diffused light of described return Defeated speed, determines the described position measuring point.

Wherein, described at least part of described Raman diffused light is carried out light splitting obtain first frequency light with And the step of second frequency light specifically includes:

The Raman scattering optical signal of 50% is coupled in described beam splitter, to obtain first frequency light And second frequency light, wherein, described first frequency light is stokes light, described second frequency Light is anti-Stokes light.

For solving above-mentioned technical problem, another technical solution used in the present invention is: provide one Temperature monitoring system based on optical fiber,

Described temperature monitoring system includes: sensor fibre, photo-coupler and light processor, its Described in photo-coupler be arranged on the transmission path of described sensor fibre, described light processor with Described circuit for light coupler connects;

Described light processor includes that the conversion of beam splitter, the first signal conversion unit, secondary signal is single Unit and signal processing unit, described first signal conversion unit and the conversion of described secondary signal are single Unit is connected with described beam splitter and signal processing unit respectively;

Described photo-coupler is for obtaining the Raman diffused light measuring some return of sensor fibre;

Described beam splitter obtains the first frequency at least part of described Raman diffused light carries out light splitting Rate light and second frequency light;

Described first converting unit, for described first frequency light is carried out opto-electronic conversion, obtains first The signal of telecommunication;Described second converting unit, for described second frequency light is carried out opto-electronic conversion, obtains Second signal of telecommunication;

Described signal processing unit is for by described first signal of telecommunication and second signal of telecommunication and survey Corresponding relation between amount temperature obtains the described measurement temperature measuring point.

Wherein, described signal processing unit is additionally operable to obtain measurement temperature and the reality of reference optical fiber Temperature;Wherein, described reference optical fiber is arranged on the transmission path of described optical signal, described reference The acquisition mode of the measurement temperature of optical fiber is identical with the acquisition mode of the described measurement temperature measuring point;

With reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, by described measurement The measurement temperature of point obtains the described actual temperature measuring point.

The invention has the beneficial effects as follows: be different from the situation of prior art, first present embodiment obtains Take sensor fibre measures the Raman diffused light that point returns, then carries out at least part of Raman diffused light Light splitting obtains first frequency light and second frequency light, respectively to first frequency light and second frequency light Carry out opto-electronic conversion, obtain first signal of telecommunication and second signal of telecommunication, finally by described first electricity Signal and second signal of telecommunication and the corresponding relation measured between temperature obtain the described measurement measuring point Temperature.By the way, be possible not only to accurately measurement point to sensor fibre carry out accurately fixed Position, in reality is measured, precision can reach 0.67 meter.And using optical fiber itself as sensor, Realize real distributed measurement, while realizing monitoring in real time, be substantially reduced wrong report and fail to report Rate.Being additionally, since optical fiber electric insulation completely itself, therefore, pulsed light is not subject in transmitting procedure The electromagnetic interference of any external environment, again owing to fiber-optic transfer data volume is big, it is little to be lost and not burn into Fire-resistant, the water-fast and characteristic of life-span length, not only in the case of without relaying, can be real accurately The most remotely monitor, additionally it is possible to effectively reduce the maintenance cost of sensor itself, and then reduce whole prison The operation cost of examining system.

Accompanying drawing explanation

Fig. 1 is the schematic flow sheet of present invention temperature monitoring method based on optical fiber one embodiment;

Fig. 2 is the schematic flow sheet of the present invention another embodiment of temperature monitoring method based on optical fiber;

Fig. 3 is the structural representation of present invention temperature monitoring system based on optical fiber one embodiment;

Fig. 4 is the structural representation of the present invention another embodiment of temperature monitoring system based on optical fiber;

Fig. 5 is the structural representation of present invention temperature monitoring system based on optical fiber a further embodiment.

Detailed description of the invention

It is the stream of present invention temperature checking method based on optical fiber one embodiment refering to Fig. 1, Fig. 1 Journey schematic diagram.As it is shown in figure 1, the temperature monitoring method of present embodiment comprises the steps:

101: obtain sensor fibre measures the Raman diffused light that point returns.

Owing to optical fiber has simple in construction, lays convenience, electric insulation, high temperature resistant, electromagnetism interference Etc. advantage, light pipe itself is carried out collecting temperature as temperature sensor by present embodiment.It is applicable to Underground or down-hole such as coal mine cable temperature monitoring etc., it is also possible to be applied to other for temperature sensitive Adverse circumstances, do not limit at this.

In order to measure the temperature of monitoring point, laser generator is in the original position of sensor fibre Sending laser, this laser, under the modulating action of light pulse manipulator, forms setting cycle and continues The short pulsed light of time, this pulsed light is being propagated on sensor fibre by photo-coupler.At arteries and veins In the transmitting procedure washed off, owing to pulsed light interacts with optical fiber molecule, there is multiple shape The scattering of formula, the drawing of being formed such as thermal vibration and photon effect generation energy exchange by optical fiber molecule Graceful scattering.The scattered light signal of different distance point has part and is back to optical coupling along transmission light path Device.

Accordingly, the optical signal measuring some return of sensor fibre is obtained by photo-coupler, as drawn Graceful scattered light.

102: at least part of described Raman diffused light is carried out light splitting and obtains first frequency light and Two frequencies of light.

Raman diffused light is during producing, due to thermal vibration and the photon phase interaction of optical fiber molecule With there is energy exchange, a part of luminous energy is converted into thermal vibration, produces a ratio light source pulse light wave Long first frequency light, i.e. stokes light, a part of thermal vibration is converted into luminous energy, produces one The individual second frequency light shorter than light pulse wavelength, i.e. anti-Stokes light.Wherein, this first frequency The side-play amount of the wavelength of light and second frequency light is determined by the fixed attribute of sensor fibre component.

Specifically, the photo-coupler of present embodiment is after receiving this Raman diffused light, by Raman Scattered light signal is coupled in described beam splitter, to obtain first frequency light and second frequency light.

In one preferred embodiment, the Raman scattering optical signal of 50% is coupled by photo-coupler In described beam splitter.

103: respectively described first frequency light and second frequency light are carried out opto-electronic conversion, obtain One signal of telecommunication and second signal of telecommunication.

Analyzed as above-mentioned, owing to pulsed light is in transmitting procedure, can be produced various dissimilar Scattered light, therefore, Raman diffused light may also be mingled with other kinds of scattered light and interference Light, in order to make temperature monitoring more accurate, need as far as possible ensure the first frequency light after light splitting and Second frequency light pure.Therefore, at beam splitter, Raman diffused light is carried out light splitting and obtain the first frequency After rate light and second frequency light, respectively the light of this two-way different frequency is processed.

Specifically, the most respectively the light of this two-way different frequency is carried out bandpass filtering treatment, obtain The purest first frequency light and second frequency light, the most again to after bandpass filtering treatment First frequency light and second frequency light carry out opto-electronic conversion and amplification, obtain first signal of telecommunication and second The signal of telecommunication.

Wherein, this first signal of telecommunication is the first magnitude of voltage, and second signal of telecommunication is the second magnitude of voltage.

Wherein, present embodiment is passed through avalanche photodide APD at bandpass filtering First frequency light and second frequency light after reason carry out opto-electronic conversion and amplification.At other embodiments In, it is also possible to by other devices to the first frequency light after bandpass filtering treatment and the second frequency Rate light carries out photoelectricity and amplification, does not limits at this.

104: by described first signal of telecommunication and second signal of telecommunication and the corresponding pass measured between temperature System obtains the described measurement temperature measuring point.

After obtaining first signal of telecommunication and second signal of telecommunication, in order to make monitoring result more accurate, Further first signal of telecommunication and second signal of telecommunication are carried out Kalman filtering.

In a specific embodiment, realize first signal of telecommunication and the second telecommunications with matlab Number Kalman filtering, to leach noise, obtain the first pure signal of telecommunication and second signal of telecommunication.

Owing to the light intensity of Raman diffused light is relevant with temperature, i.e. can be by the of first frequency light The ratio of the second light intensity of one light intensity and second frequency light determines the test temperature measuring point.

Specifically, there is corresponding relation in the first light intensity and first signal of telecommunication that is first magnitude of voltage, and second There is corresponding relation in light intensity and second signal of telecommunication that is second magnitude of voltage, therefore, and can be according to the first voltage Value obtains the first light intensity, obtains the second light intensity according to the second magnitude of voltage.Passing through formulaReally Temperature R (T) of location survey amount point, wherein, IaIt is the first light intensity, IsIt it is the second light intensity.

By the way, can accurately the measurement point of sensor fibre be accurately positioned, In actual measurement, precision can reach 0.67 meter.And using optical fiber itself as sensor, it is achieved Real distributed measurement, is substantially reduced wrong report and rate of failing to report while realizing monitoring in real time.

Owing to when the temperature of reality measurement point, the first frequency light and second that wavelength is different is frequently The decay of rate light there are differences, and detector there is also difference to the response of the two, therefore, even if First signal of telecommunication and second signal of telecommunication are carried out repeatedly Filtering Processing, however it remains error.This reality Execute in mode and eliminate this error by reference optical fiber.

Specifically referring to Fig. 2, Fig. 2 is another enforcement of present invention temperature monitoring method based on optical fiber The schematic flow sheet of mode.Present embodiment is by described first signal of telecommunication and second signal of telecommunication And also wrap after the step of the measurement temperature that the corresponding relation measured between temperature obtains described measurement point Include:

205: obtain measurement temperature and the actual temperature of reference optical fiber;.

Wherein, this reference optical fiber is arranged on the transmission path of the i.e. pulsed light of optical signal.Alternatively, In order to reduce error, this reference optical fiber is arranged on first 200 meters of this sensor fibre.

Specifically, first obtain this reference optical fiber measurement temperature and actual temperature.Wherein, should The acquisition mode of the measurement temperature of the acquisition mode of the measurement temperature of reference optical fiber and above-mentioned measurement point Identical, do not repeat them here.This actual temperature is the temperature that this reference optical fiber is stored in calorstat. In a specific embodiment, this actual temperature can be come corresponding by a magnitude of voltage.

206: with reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, by institute The measurement temperature stating measurement point obtains the described actual temperature measuring point.

Specifically, being tried to achieve actual temperature T measuring point by formula 1, formula 1 is as followsWherein, described R (T) is the described measurement temperature measuring point, Described R (T0) it is the measurement temperature of described reference optical fiber, described T0Actual temperature for described reference optical fiber Degree, h is Planck's constant, and c is the light velocity, and μ is Boltzmann constant, and described k is Boltzmann Constant, wherein, K=1.3806488 (13) × 10^-23J/K.

By the way, it is possible to eliminate first frequency light and second frequency light further due to wavelength Different and the difference in attenuation that produces and response difference, improve the temperature measuring point monitored.

In any of the above-described enforcement embodiment, after the actual temperature obtaining measurement point, in order to enter One step determines whether the actual temperature of this sampled point exists exception, as increased substantially or reducing, needs Further the temperature of this monitoring point is judged.

Specifically, actual temperature phase actual temperature current for this measurement point and previous moment obtained Relatively, it is judged that whether described measurement is sent out between the current actual temperature of point and the actual temperature that obtains before The raw change exceeding setting value, if it occur that change, determines whether that whether this change is at default model In enclosing, if in preset range, then the temperature representing this measurement point is normal.If this change is not Do not have in preset range, then send the warning that this measurement point temperature changes.

In any of the above-described embodiment, after obtaining measuring some temperature, further determine that this measurement Point is positioned at the position of sensor fibre, i.e. realizes the location to test point.

In an optional enforcement embodiment, by returning the biography of the Raman diffused light of photo-coupler Defeated time and the transmission speed of this Raman diffused light, i.e. distance=transmission time * transmission speed is former Reason determines the position of this measurement point.

In another particular embodiment of the invention, come really according to the signal sampling frequency of Raman diffused light The position of location survey amount point, such as, sample frequency is 150MHZ, 150M data of collection per second, So time corresponding to each data point is t=1/1.5ns, if the spread speed that light is in a fiber is C=2*108M/s, then corresponding between two sampled points actual range s are S=ct=2*108* (1/1.5)=0.65m.Quantity at the sampled point according to interval determines distance.

In any of the above-described embodiment, to first signal of telecommunication that is first magnitude of voltage and second signal of telecommunication The device that i.e. second magnitude of voltage carries out processing is formed to the laser sent by laser instrument simultaneously and sets week The light pulse manipulator of the short pulsed light of phase and persistent period provides clock, and therefore, this process fills Put Tong Bu with the work clock of light pulse manipulator.

Being different from prior art, first present embodiment obtains drawing of the measurement point return of sensor fibre Graceful scattered light, more at least part of Raman diffused light is carried out light splitting obtain first frequency light and second Frequencies of light, carries out opto-electronic conversion to first frequency light and second frequency light respectively, obtains the first telecommunications Number and second signal of telecommunication, finally by described first signal of telecommunication and second signal of telecommunication with measure temperature Corresponding relation between degree obtains the described measurement temperature measuring point.By the way, it is possible not only to Accurately being accurately positioned the measurement point of sensor fibre, in reality is measured, precision can reach To 0.67 meter.And using optical fiber itself as sensor, it is achieved real distributed measurement, in reality Wrong report and rate of failing to report it is substantially reduced while monitoring during reality.It is additionally, since optical fiber electricity completely itself Insulation, therefore, pulsed light in transmitting procedure not by the electromagnetic interference of any external environment, again by Big in fiber-optic transfer data volume, be lost little and burn into is not fire-resistant, water-fast and the characteristic of life-span length, Not only in the case of without relaying, can realize accurately remotely monitoring, additionally it is possible to effectively reduce The maintenance cost of sensor itself, and then reduce the operation cost of whole monitoring system.

It addition, arrange reference optical fiber on the transmission path of optical signal, by with reference to this reference optical fiber Measurement temperature and actual temperature between relation, according further to measure point measurement temperature obtain To the actual temperature of measurement point, finally represented the temperature of this measurement point by this actual temperature, it is possible to The difference in attenuation that further elimination first frequency light is different due to wavelength with second frequency light and produces And response difference, improve the temperature measuring point monitored.

It addition, after determining the actual temperature measuring point, it is judged that current actual temperature is with before To actual temperature between whether exceed the change of setting value, and send described when changing Measure the alarm that the temperature of point changes, it is possible to realize the most long-range detection.

It is the knot of present invention temperature monitoring system based on optical fiber one embodiment refering to Fig. 3, Fig. 3 Structure schematic diagram.

As it is shown on figure 3, the system for detecting temperature of present embodiment includes sensor fibre 301, optocoupler Clutch 302 and light processor 303, wherein, this photo-coupler 302 and light processor 303 Circuit connects, further as it is shown on figure 3, this light processor 303 include beam splitter 3031, the One signal conversion unit 3032, secondary signal converting unit 3033 and signal processing unit 3034, Wherein, this first signal conversion unit 3032 and secondary signal converting unit 3033 respectively with point Light device 3031 and signal processing unit 3034 circuit connect.

This photo-coupler 302 is for obtaining the Raman scattering measuring some return of sensor fibre 301 Light.

Owing to optical fiber has simple in construction, lays convenience, electric insulation, high temperature resistant, electromagnetism interference Etc. advantage, light pipe itself is carried out collecting temperature as temperature sensor by present embodiment.It is applicable to Underground or down-hole such as coal mine cable temperature monitoring etc., it is also possible to be applied to other for temperature sensitive Adverse circumstances, do not limit at this.

In order to the temperature of monitoring point is measured, the most as shown in Figure 4, laser generator 404 Original position at sensor fibre 401 sends laser, and this laser is at the tune of light pulse manipulator 405 Making under using, form setting cycle and the short pulsed light of persistent period, this pulsed light is passing through light Bonder 401 is propagated on sensor fibre.In the transmitting procedure of pulsed light, due to pulsed light with Optical fiber molecule interacts, and the scattering of various ways occurs, such as the thermal vibration by optical fiber molecule The Raman scattering formed with photon effect generation energy exchange.The scattered light signal of different distance point Have part and be back to photo-coupler 402 along transmission light path.

Accordingly, photo-coupler obtains the optical signal measuring some return of sensor fibre, as Raman dissipates Penetrate light.

Beam splitter 3031 obtains the first frequency at least part of described Raman diffused light carries out light splitting Rate light and second frequency light.

Further regarding to Fig. 3, Raman diffused light is during producing, due to the heat of optical fiber molecule Vibration and photon interact and energy exchange occur, and a part of luminous energy is converted into thermal vibration, produce one The individual first frequency light longer than light source pulse optical wavelength, i.e. stokes light, a part of thermal vibration turns Change luminous energy into, produce the second frequency light shorter than light pulse wavelength, i.e. an anti-Stokes light. Wherein, the side-play amount of the wavelength of this first frequency light and second frequency light is by sensor fibre component Fixed attribute determine.

Specifically, the photo-coupler 302 of present embodiment, will after receiving this Raman diffused light Raman scattering optical signal is coupled in described beam splitter 3031, and beam splitter 3031 is at least part of institute State Raman diffused light to carry out light splitting and obtain first frequency light and second frequency light.

In one preferred embodiment, photo-coupler 302 by 50% Raman scattering optical signal It is coupled in described beam splitter 3031.

First converting unit 3032, for described first frequency light is carried out opto-electronic conversion, obtains the One signal of telecommunication;Described second converting unit 3033 turns for described second frequency light is carried out photoelectricity Change, obtain second signal of telecommunication.

Analyzed as above-mentioned, owing to pulsed light is in transmitting procedure, can be produced various dissimilar Scattered light, therefore, Raman diffused light may also be mingled with other kinds of scattered light and interference Light, in order to make temperature monitoring more accurate, need as far as possible ensure the first frequency light after light splitting and Second frequency light pure.Therefore, at beam splitter 3031, Raman diffused light is carried out light splitting to obtain After first frequency light and second frequency light, respectively the light of this two-way different frequency is processed.

Specifically, the first converting unit 3032 carries out bandpass filtering treatment to first frequency light, so After again the first frequency light after bandpass filtering treatment is carried out opto-electronic conversion and amplification, obtain One signal of telecommunication.Second converting unit 3033 carries out bandpass filtering treatment to second frequency light, then Again the second frequency light after bandpass filtering treatment is carried out opto-electronic conversion and amplification, obtain second The signal of telecommunication.

Wherein, this first signal of telecommunication is the first magnitude of voltage, and second signal of telecommunication is the second magnitude of voltage.

Wherein, in present embodiment, the first converting unit 3032 and the second converting unit 3033 are By avalanche photodide APD to the first frequency light and second after bandpass filtering treatment Frequencies of light carries out opto-electronic conversion and amplification.In other embodiments, it is also possible to by other devices First frequency light after bandpass filtering treatment and second frequency light are carried out photoelectricity and amplification, This does not limits.

Signal processing unit 3034 is for by described first signal of telecommunication and second signal of telecommunication and survey Corresponding relation between amount temperature obtains the described measurement temperature measuring point.

After obtaining first signal of telecommunication and second signal of telecommunication, in order to make monitoring result more accurate, Signal processing unit 3034 carries out Kalman's filter to first signal of telecommunication and second signal of telecommunication further Ripple.

In a specific embodiment, signal processing unit 3034 matlab realizes the One signal of telecommunication and the Kalman filtering of second signal of telecommunication, to leach noise, obtain the first pure electricity Signal and second signal of telecommunication.

Owing to the light intensity of Raman diffused light is relevant with temperature, signal processing unit 3034 is that is permissible Measurement is determined by the ratio of the first light intensity of first frequency light Yu the second light intensity of second frequency light The test temperature of point.

Specifically, there is corresponding relation in the first light intensity and first signal of telecommunication that is first magnitude of voltage, and second There is corresponding relation in light intensity second signal of telecommunication that is second magnitude of voltage, therefore, and signal processing unit 3034 The first light intensity can be obtained according to the first magnitude of voltage, obtain the second light intensity according to the second magnitude of voltage.Logical Cross formulaDetermine temperature R (T) measuring point, wherein, IaIt is the first light intensity, IsFor Second light intensity.

By the way, can accurately the measurement point of sensor fibre be accurately positioned, In actual measurement, precision can reach 0.67 meter.And using optical fiber itself as sensor, it is achieved Real distributed measurement, is substantially reduced wrong report and rate of failing to report while realizing monitoring in real time.

Owing to when the temperature of reality measurement point, the first frequency light and second that wavelength is different is frequently The decay of rate light there are differences, and detector there is also difference to the response of the two, therefore, even if First signal of telecommunication and second signal of telecommunication are carried out repeatedly Filtering Processing, however it remains error.This reality Execute in mode and eliminate this error by reference optical fiber.

Further as it is shown in figure 5, also include calorstat on the transmission path of the i.e. pulsed light of optical signal 506, this calorstat is provided with reference optical fiber, and preserves the actual temperature of reference optical fiber.

Alternatively, in order to reduce error, this calorstat 506 arranging reference optical fiber is arranged on this biography First 200 meters of photosensitive fibre.

Specifically, signal processing unit 5034 obtain this reference optical fiber measurement temperature and reality Temperature.Wherein, the acquisition mode of the measurement temperature of this reference optical fiber and the measurement temperature of above-mentioned measurement point The acquisition mode of degree is identical, does not repeats them here.This actual temperature is that this reference optical fiber is stored in perseverance The temperature of incubator.In a specific embodiment, this actual temperature can be come corresponding by a magnitude of voltage.

Signal processing unit 5034 is with further reference to measurement temperature and the reality temperature of described reference optical fiber Relation between degree, is obtained the described actual temperature measuring point by the described measurement temperature measuring point.

Specifically, signal processing unit 5034 tries to achieve actual temperature T measuring point by formula 1, Formula 1 is as followsWherein, described R (T) is described survey The measurement temperature of amount point, described R (T0) it is the measurement temperature of described reference optical fiber, described T0For described The actual temperature of reference optical fiber, h is Planck's constant, and c is the light velocity, and μ is Boltzmann constant, Described k is Boltzmann constant, wherein, and K=1.3806488 (13) × 10^-23J/K.

By the way, it is possible to eliminate first frequency light and second frequency light further due to wavelength Different and the difference in attenuation that produces and response difference, improve the temperature measuring point monitored.

In any of the above-described enforcement embodiment, signal processing unit is obtaining measuring the actual temperature of point After degree, in order to further determine that whether the actual temperature of this sampled point exists exception, as significantly carried Height or reduction, need judge the temperature of this monitoring point further.

Specifically, actual temperature current for this measurement point is obtained by signal processing unit with previous moment Actual temperature compare, it is judged that described measure the current actual temperature of point and the reality obtained before Whether exceed the change of setting value between temperature, if it occur that change, determine whether this change Whether in preset range, if in preset range, then the temperature representing this measurement point is normal. If this change does not have in preset range, then send the warning that this measurement point temperature changes.

In any of the above-described embodiment, after obtaining measuring some temperature, signal processing unit enters one Step determines that this measurement point is positioned at the position of sensor fibre, i.e. realizes the location to test point.

In an optional enforcement embodiment, signal processing unit is by returning drawing of photo-coupler The transmission time of graceful scattered light and the transmission speed of this Raman diffused light, i.e. distance=transmission time * The principle of transmission speed determines the position of this measurement point.

In another particular embodiment of the invention, signal processing unit is according to the signal of Raman diffused light Sample frequency determines the position measuring point, and such as, sample frequency is 150MHZ, collection per second 150M data, so time corresponding to each data point is t=1/1.5ns, if light is at optical fiber In spread speed be c=2*108M/s, then corresponding between two sampled points actual range s are S=ct=2*108* (1/1.5)=0.65m.Quantity at the sampled point according to interval determines distance.

In any of the above-described embodiment, to first signal of telecommunication that is first magnitude of voltage and second signal of telecommunication The signal processing unit that i.e. second magnitude of voltage carries out processing is simultaneously to the laser shape sent by laser instrument The light pulse manipulator offer clock of one-tenth setting cycle and the short pulsed light of persistent period, therefore, This signal processing unit is Tong Bu with the work clock of light pulse manipulator.Such as signal processing list in Fig. 4 Unit 4034 is connected with light pulse manipulator 405 circuit, signal processing unit 5034 and light in Fig. 5 Pulse-modulator 505 circuit connects.

Being different from prior art, the photo-coupler of present embodiment temperature monitoring system obtains sense light Fine measures the Raman diffused light that point returns, and beam splitter carries out light splitting at least part of Raman diffused light Obtaining first frequency light and second frequency light, the first converting unit is for carrying out first frequency light Opto-electronic conversion, obtains first signal of telecommunication;Second converting unit is for carrying out photoelectricity to second frequency light Conversion, obtains second signal of telecommunication, and signal processing unit is by described first signal of telecommunication and the second electricity Signal and the corresponding relation measured between temperature obtain the described measurement temperature measuring point.By above-mentioned side Formula, is possible not only to accurately be accurately positioned the measurement point of sensor fibre, in reality is measured, Precision can reach 0.67 meter.And using optical fiber itself as sensor, it is achieved real is distributed Measure, while realizing monitoring in real time, be substantially reduced wrong report and rate of failing to report.It is additionally, since optical fiber Complete electric insulation itself, therefore, pulsed light in transmitting procedure not by the electromagnetism of any external environment Interference, again owing to fiber-optic transfer data volume is big, it is little to be lost and burn into is not fire-resistant, water-fast and the life-span Long characteristic, not only in the case of without relaying, can realize remotely monitoring accurately, moreover it is possible to The most effectively reduce the maintenance cost of sensor itself, and then the operation reducing whole monitoring system becomes This.

It addition, arrange reference optical fiber on the transmission path of optical signal, by with reference to this reference optical fiber Measurement temperature and actual temperature between relation, according further to measure point measurement temperature obtain To the actual temperature of measurement point, finally represented the temperature of this measurement point by this actual temperature, it is possible to The difference in attenuation that further elimination first frequency light is different due to wavelength with second frequency light and produces And response difference, improve the temperature measuring point monitored.

It addition, after determining the actual temperature measuring point, it is judged that current actual temperature is with before To actual temperature between whether exceed the change of setting value, and send described when changing Measure the alarm that the temperature of point changes, it is possible to realize the most long-range detection.

The foregoing is only embodiments of the present invention, not thereby limit the patent model of the present invention Enclosing, every equivalent structure utilizing description of the invention and accompanying drawing content to be made or equivalence flow process become Change, or be directly or indirectly used in other relevant technical fields, be the most in like manner included in the present invention's In scope of patent protection.

Claims (10)

1. a temperature monitoring method based on optical fiber, it is characterised in that described temperature monitoring method Including:
Obtain sensor fibre measures the Raman diffused light that point returns;
At least part of described Raman diffused light is carried out light splitting and obtains first frequency light and the second frequency Rate light;
Respectively described first frequency light and second frequency light are carried out opto-electronic conversion, obtain the first telecommunications Number and second signal of telecommunication;
Obtained by described first signal of telecommunication and second signal of telecommunication and the corresponding relation measured between temperature To the described measurement temperature measuring point.
Temperature monitoring method the most according to claim 1, it is characterised in that described in pass through institute State first signal of telecommunication and second signal of telecommunication and the corresponding relation measured between temperature obtains described measurement Also include after the step of the measurement temperature of point:
Obtain measurement temperature and the actual temperature of reference optical fiber;Wherein, described reference optical fiber is arranged On the transmission path of optical signal, the acquisition mode of the measurement temperature of described reference optical fiber and described survey The acquisition mode of the measurement temperature of amount point is identical;
With reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, by described measurement The measurement temperature of point obtains the described actual temperature measuring point.
3. according to the temperature monitoring method described in right 2, it is characterised in that described with reference to described ginseng Examine the relation between measurement temperature and the actual temperature of optical fiber, the described measurement temperature measuring point obtain Step to the described actual temperature measuring point includes:
According to formula 1:Try to achieve the described actual temperature measuring point Degree T,
Wherein, described R (T) is the described measurement temperature measuring point, described R (T0) it is described reference light Fine measurement temperature, described T0For the actual temperature of described reference optical fiber, h is Planck's constant, c For the light velocity, μ is Boltzmann constant, and described k is Boltzmann constant, wherein, K=1.3806488 (13) × 10^-23J/K.
Temperature monitoring method the most according to claim 2, it is characterised in that also include:
Judge whether described measurement is sent out between the current actual temperature of point and the actual temperature that obtains before The raw change exceeding setting value;
The most then send the alarm that the described temperature measuring point changes.
5. according to the temperature monitoring method described in right 1, it is characterised in that described first signal of telecommunication Being the first magnitude of voltage, described second point signal is the second magnitude of voltage,
Described by described first signal of telecommunication and second signal of telecommunication and the corresponding pass measured between temperature System obtains the step of the described measurement temperature measuring point and specifically includes:
Described first frequency light is obtained respectively according to described first magnitude of voltage and the second magnitude of voltage First light intensity and the second light intensity of second frequency light;
The ratio of described first light intensity and described second light intensity is defined as the described test measuring point Temperature.
Temperature monitoring method the most according to claim 1, it is characterised in that in described difference Described first frequency light and second frequency light are carried out opto-electronic conversion, obtains first signal of telecommunication and After the step of two signals of telecommunication, described method also includes:
Described first signal of telecommunication and second signal of telecommunication are carried out Kalman filtering respectively.
Cable temperature monitoring method the most according to claim 1, it is characterised in that described in obtain After taking the step measuring the Raman diffused light that point returns of sensor fibre, also include:
By transmission time and the biography of described Raman diffused light of the Raman diffused light of described return Defeated speed, determines the described position measuring point.
Temperature monitoring method the most according to claim 1, it is characterised in that described at least The described Raman diffused light of part carries out light splitting and obtains first frequency light and the step of second frequency light Specifically include:
The Raman scattering optical signal of 50% is coupled in described beam splitter, to obtain first frequency light And second frequency light, wherein, described first frequency light is stokes light, described second frequency Light is anti-Stokes light.
9. a temperature monitoring system based on optical fiber, it is characterised in that described temperature monitoring system Including: sensor fibre, photo-coupler and light processor, wherein said photo-coupler is arranged on On the transmission path of described sensor fibre, described light processor is with described circuit for light coupler even Connect;
Described light processor includes that the conversion of beam splitter, the first signal conversion unit, secondary signal is single Unit and signal processing unit, described first signal conversion unit and the conversion of described secondary signal are single Unit is connected with described beam splitter and signal processing unit respectively;
Described photo-coupler is for obtaining the Raman diffused light measuring some return of sensor fibre;
Described beam splitter obtains the first frequency at least part of described Raman diffused light carries out light splitting Rate light and second frequency light;
Described first converting unit, for described first frequency light is carried out opto-electronic conversion, obtains first The signal of telecommunication;Described second converting unit, for described second frequency light is carried out opto-electronic conversion, obtains Second signal of telecommunication;
Described signal processing unit is for by described first signal of telecommunication and second signal of telecommunication and survey Corresponding relation between amount temperature obtains the described measurement temperature measuring point.
Temperature monitoring system the most according to claim 9, it is characterised in that at described signal Reason unit is additionally operable to obtain measurement temperature and the actual temperature of reference optical fiber;Wherein, described reference Optical fiber is arranged on the transmission path of described optical signal, the acquisition of the measurement temperature of described reference optical fiber Mode is identical with the acquisition mode of the described measurement temperature measuring point;
With reference to the relation between measurement temperature and the actual temperature of described reference optical fiber, by described measurement The measurement temperature of point obtains the described actual temperature measuring point.
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