CN107966234A - Based on stress distribution measuring device and method suffered by the film surface of optical fiber grating sensing - Google Patents
Based on stress distribution measuring device and method suffered by the film surface of optical fiber grating sensing Download PDFInfo
- Publication number
- CN107966234A CN107966234A CN201711188867.4A CN201711188867A CN107966234A CN 107966234 A CN107966234 A CN 107966234A CN 201711188867 A CN201711188867 A CN 201711188867A CN 107966234 A CN107966234 A CN 107966234A
- Authority
- CN
- China
- Prior art keywords
- fiber
- grating
- optic grating
- optical fiber
- film surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L11/00—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00
- G01L11/02—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means
- G01L11/025—Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00 by optical means using a pressure-sensitive optical fibre
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Length Measuring Devices By Optical Means (AREA)
- Optical Transform (AREA)
- Separation Using Semi-Permeable Membranes (AREA)
Abstract
The invention discloses stress distribution measuring method, step suffered by a kind of film surface based on optical fiber grating sensing to be：Select multifiber grating sensor, and the centre wavelength difference of any two of which fiber-optic grating sensor is not less than 2nm, multifiber grating sensor is connected with single mode optical fiber, it is fixed on after applying prestressing force to the fiber-optic grating sensor after series connection using UV glue on membrane module, makes the distance between each fiber-optic grating sensor and film surface in 0 1mm；It is connected after membrane module is encapsulated with fiber Bragg grating (FBG) demodulator, the software carried using fiber Bragg grating (FBG) demodulator measure the centre wavelength of each fiber-optic grating sensor quiescent value and water filling after measured value and changing value, finally according to the sensing principle of light grating obtain it is different in flow rate in the case of stress suffered by film surface distribution situation so that further to lay a good foundation to the science judgment of film surface hydraulics state.
Description
Technical field
The present invention relates to fiber grating sensing technology and Membrane Separation for Water Treatment field, more particularly to one kind to be based on optical fiber light
The film surface stress distribution measurement system of grid sensing.
Background technology
Membrane technology is because of series of advantages such as its energy saving, efficient, economic, simple and convenient, non-secondary pollutions, in water process
It is widely used in brackish water desalination, sea water desalination, industrial water supply processing, pure water and ultra-pure water preparation, wastewater treatment, sewage time
With etc..But in water treatment by membrane such as positive process of osmosis, there are the problem of concentration polarization and fouling membrane so that flux declines.It is logical
Change operating condition (water velocity and pressure etc.) is crossed, concentration polarization and fouling membrane can be slowed down.If can be to the institute of membrane interface
Measured by stress, then can effectively understand film surface hydraulics situation, control fouling membrane, the control hydraulic pressure and energy of science
Consumption, instructs optimization component structure etc..Since membrane pore size is mostly following in the micron-scale in membrane separating process, while pollution and product
It is often also following in the micron-scale in the particulate matter of film surface, therefore hydraulics behavior of the analysis pollutant on film surface can not pass through
It is generally used for the hydraulics analysis equipment in large scale flow field and obtains.At present, can also be directly right without means effectively
The suffered stress of film surface measures, in general, the analysis to film surface in membrane separating process, it is most of be all by numerical simulation and
The method of Fluid Mechanics Computation, analyzes the flow velocity of film surface diverse location, pressure and concentration.
Optical fiber grating structure is simple, light weight, corrosion-resistant, it is small and itself be sensing element, to testee
Influence small, can be used for measuring the physical quantity variation technology in narrow space, and can carry out by distributive array more
Point measurement.Since it can construct the scale category more close with the behavior of film surface microfluid in shape, it is set directly to survey
The information for measuring the hydraulics behavior of film surface is possibly realized.
There has been no the measuring system of the film surface stress distribution based on fiber grating sensing technology at present.
The content of the invention
It is of the invention by fiber grating for board-like forward osmosis membrane component common in prior art forward osmosis membrane treatment technology
It is placed in forward osmosis membrane component, there is provided stress distribution measuring device, Ke Yishi suffered by a kind of film surface based on optical fiber grating sensing
Now stress suffered by synchronization film surface diverse location is measured.The present invention is mainly based upon the characteristic and sensing of fiber grating
Principle, using the method for wavelength-division multiplex, will be evenly distributed on film surface, to film in membrane separating process after multifiber gratings in series
Stress distribution suffered by the diverse location of face is analyzed.
In order to solve the above-mentioned technical problem, all stress of a kind of film surface based on optical fiber grating sensing proposed by the present invention point
Cloth measuring device, its basic scheme are, including the multiple fiber-optic grating sensors being fixed in membrane module, the multiple optical fiber light
The gate sensor position mutual with the membrane module and connection relation be, multiple fiber-optic grating sensors are according to along membrane module
Water (flow) direction during work and the distribution arrangement in gallery regional extent, the film of multiple fiber-optic grating sensors and the membrane module
The distance between face is in 0-1mm；The grating wavelength non-overlapping copies of each fiber-optic grating sensor；Multiple fiber-optic grating sensors are successively
Connected with single mode optical fiber；One end of fiber-optic grating sensor after series connection is free end, the fiber-optic grating sensor after series connection
The other end is connected by single mode optical fiber with the input terminal of a fiber Bragg grating (FBG) demodulator；The output terminal of the fiber Bragg grating (FBG) demodulator
A computer is connected to, data acquisition module and data processing module, the data acquisition module are installed in the computer
Block uses the software supporting with the optical fiber grating sensing demodulator；The data processing module is former according to the sensing of fiber grating
Reason show that the membrane module film surface is all by the change of the grating wavelength of the above-mentioned multiple fiber-optic grating sensors collected and answers
The distribution of power.
All stress distribution measuring devices of a kind of film surface based on optical fiber grating sensing proposed in the present invention, its combination side
Case is, including more sets are fixed with the membrane module of multiple fiber-optic grating sensors, and membrane module is hollow-fibre membrane or plate membrane
Or rolled film；Often set is fixed with the membrane module of multiple fiber-optic grating sensors, the multiple fiber-optic grating sensor and institute
It is that multiple fiber-optic grating sensors are according to current when working along membrane module to state the mutual position of membrane module and connection relation
The distance between film surface of direction and the distribution arrangement in gallery regional extent, multiple fiber-optic grating sensors and the membrane module
In 0-1mm；The grating wavelength non-overlapping copies of each fiber-optic grating sensor；Multiple fiber-optic grating sensors are successively with single mode optical fiber string
Connection, so as to form a set of membrane module for being fixed with multiple fiber-optic grating sensors；Each set is fixed with multiple optical fiber grating sensings
Two free ends of the fiber grating of the membrane module of device are connected with single mode optical fiber, and connection mode is serial or parallel connection or connection in series-parallel；Will
More sets after connection be fixed with one end of the fiber grating in the membrane module of multiple fiber-optic grating sensors by single mode optical fiber with
The input terminal of one fiber Bragg grating (FBG) demodulator is connected；The output terminal of the fiber Bragg grating (FBG) demodulator is connected to a computer, institute
State and data acquisition module and data processing module are installed in computer, the data acquisition module uses and the fiber grating
The supporting software of sensing demodulator；The data processing module is above-mentioned more by what is collected according to the sensing principle of fiber grating
The change of the grating wavelength of a fiber-optic grating sensor draws the distribution of all stress of membrane module film surface.
Further, in the present invention, the bandwidth of the fiber-optic grating sensor is 0.2nm, reflectivity is higher than 90%, grid region
Length is 10mm and adds coating, the centre wavelength scope of fiber-optic grating sensor to be 1530nm-1570nm, and the fiber grating passes
The centre wavelength of sensor is only influenced by temperature and strain.
The membrane module is any type of ultrafiltration membrane, hollow-fibre membrane, forward osmosis membrane component and reverse osmosis membrane assembly.
The fiber Bragg grating (FBG) demodulator uses Dynamic Optical Fiber grating demodulation instrument.
The data acquisition module uses the software supporting with Dynamic Optical Fiber grating demodulation instrument, and the data acquisition module is set
The data acquiring frequency put is 1-1000 data of collection per second.
The forward osmosis membrane component is board-like forward osmosis membrane component, and the board-like forward osmosis membrane component includes material liquid side cover
Plate, draw liquid side cover plate and FO films, be equipped with the inside of the material liquid side cover plate material liquid groove, material liquid gasket, material liquid into
The mouth of a river and material liquid water outlet, it is described draw to be equipped with the inside of liquid side cover plate draw liquid groove, draw fluid cushion piece, draw liquid water inlet
With draw liquid water outlet；The multiple fiber-optic grating sensor position mutual with the membrane module and connection relation be,
Multiple fiber-optic grating sensors are arranged on the inside of the material liquid side cover plate according to water (flow) direction when working along membrane module
Face or it is described draw liquid side cover plate medial surface, each fiber-optic grating sensor is applied after prestressing force and with the film of the FO films
In 0-1mm, the material liquid side cover plate or draw is used between liquid side cover plate and the fiber-optic grating sensor in the distance between face
UV glue is fixed；The material liquid side cover plate and described draw after liquid side cover plate fastens are connected with part and fixed, so that more
A fiber-optic grating sensor is fixed with the positive filtration module.
The number of the fiber-optic grating sensor is 6, and between the grating of adjacent fiber grating sensor is apart
1cm, the grating wavelength of adjacent fiber grating sensor differ 2~3nm.The grating wavelength of 6 fiber-optic grating sensors is respectively
1556nm、1553nm、1550nm、1548nm、1546nm、1544nm。
It also proposed all stress distribution measuring methods of film surface based on optical fiber grating sensing in the present invention, utilize above-mentioned base
It is as follows in all stress distribution measuring devices of the film surface of optical fiber grating sensing, step：
Step 1: selection multifiber grating sensor, and the centre wavelength of any two of which fiber-optic grating sensor
Difference is not less than 2nm, and multifiber grating sensor is connected with single mode optical fiber, and the fiber-optic grating sensor after series connection is applied
It is fixed on after prestressing force using UV glue on membrane module, makes the distance between each fiber-optic grating sensor and film surface in 0-1mm；Will
It is connected after membrane module encapsulation with the fiber Bragg grating (FBG) demodulator, the software carried using the fiber Bragg grating (FBG) demodulator measures each light
The quiescent value of the centre wavelength of fiber grating sensor；
Step 2: the water outlet of a water pump is connected with the water inlet of membrane module, enter water to membrane module using the water pump
Mouth water filling, setting flow velocity is more than 0 and is less than 0.5m/s, arrived from childhood in the flow rates and select multiple flow velocitys greatly, according to selected
The circulation of multiple flow velocitys carry out the process of step 3 and step 4, until performing step after completing the data acquisition under multiple flow velocitys
Five；
Passed Step 3: data acquisition module gathers each fiber grating with the frequency acquisition of 1-1000 data of collection per second
The centre wavelength of sense, after optical fiber grating sensing demodulator demodulates the wavelength signals collected, the fiber Bragg grating (FBG) demodulator is certainly
The software of band obtains the measured value of the centre wavelength of each fiber-optic grating sensor in real time in the injecting process；
Step 4: the measured value that step 3 is obtained subtracts the quiescent value of step 1 acquisition, obtain each fiber grating and pass
Changing value of the sensor in the centre wavelength at each moment；Each fiber-optic grating sensor of gained in the collection period is asked for each
The average value of the changing value of the centre wavelength at moment, the center using the average value as each fiber-optic grating sensor in the period
The changing value of wavelength；
Step 5: using mapping software, using fiber-optic grating sensor apart from membrane module water inlet distance as abscissa, with
The changing value of the centre wavelength of each fiber-optic grating sensor is ordinate in the collection period that step 4 obtains, and draws out collection
In period it is different in flow rate under each fiber-optic grating sensor center wavelength variation distribution map；
Step 6: using step 5 obtain collection the period in it is different in flow rate under each fiber-optic grating sensor middle cardiac wave
Long changing value, according to the sensing principle of light grating obtain it is different in flow rate in the case of stress suffered by film surface distribution situation.
Compared with prior art, the beneficial effects of the invention are as follows：
The present invention is by the use of fiber-optic grating sensor as sensing primitive, using the method for wavelength-division multiplex, by multifiber
Gratings in series is placed in board-like forward osmosis membrane component, it is contacted with film surface, in the micro-interface research to film, being divided
Cloth measures, and the stress suffered by film surface diverse location is analyzed.The analysis method of stress suffered by this film surface based on optical fiber,
Solve the problems, such as that micro-interface, small space can not stress situations effectively suffered by Real-time Feedback film surface.And pass through fiber Bragg grating (FBG) demodulator
The signal of measurement is demodulated, signal is changed into the change of raster center wavelength, and then is analyzed and processed, composition is based on optical fiber
The film surface stress distribution measurement system of grating sensing technique.
Brief description of the drawings
Fig. 1 is the block diagram of the invention based on stress distribution measuring device suffered by the film surface of optical fiber grating sensing；
Fig. 2 is that the main view of the invention based on one embodiment of stress distribution measuring device suffered by the film surface of optical fiber grating sensing is cutd open
View；
Fig. 3 is the top view of measuring device shown in Fig. 2；
Fig. 4 is the center wavelength variation distribution map for the fiber-optic grating sensor that one embodiment of measuring method of the present invention is drawn.
Embodiment
Technical solution of the present invention is described in further detail with specific embodiment below in conjunction with the accompanying drawings, it is described specific
Embodiment is only explained the present invention, is not intended to limit the invention.
The mentality of designing of the present invention is, the characteristics of based on fiber grating and theory of the fiber optical, fiber grating is put
In in membrane module, used in studying the micro-interface of film, distribution measuring is carried out, the stress suffered by film surface diverse location is divided
Analysis.The analysis method of stress suffered by this film surface based on optical fiber, solve micro-interface, small space can not effective Real-time Feedback film surface
The problem of suffered stress situation.
Stress distribution measuring device suffered by a kind of film surface based on optical fiber grating sensing proposed by the present invention, as shown in Figure 1,
Including membrane module, fiber-optic grating sensor, fiber Bragg grating (FBG) demodulator, data acquisition module and data processing module, the number
It is installed on according to acquisition module and data processing module in a computer.Multiple fiber-optic grating sensors are fixed in membrane module, institute
It is multiple fiber-optic grating sensors to state multiple fiber-optic grating sensors position mutual with the membrane module and connection relation
Arrangement, multiple fiber-optic grating sensors and institute are distributed according to water (flow) direction when working along membrane module and in gallery regional extent
The distance between film surface of membrane module is stated in 0-1mm；The distance between the grating of adjacent fiber grating sensor is unrestricted, respectively
The grating wavelength non-overlapping copies of fiber-optic grating sensor；Multiple fiber-optic grating sensors are connected with single mode optical fiber successively；After series connection
One end of fiber-optic grating sensor be free end, the other end of the fiber-optic grating sensor after series connection passes through single mode optical fiber and one
The input terminal of fiber Bragg grating (FBG) demodulator is connected；The output terminal of the fiber Bragg grating (FBG) demodulator is connected to a computer, described
Data acquisition module and data processing module are installed, the data acquisition module is used to be passed with the fiber grating in computer
Feel the supporting software of (FBG) demodulator；The data processing module is above-mentioned multiple by what is collected according to the sensing principle of fiber grating
The change of the grating wavelength of fiber-optic grating sensor draws the distribution of stress suffered by the membrane module film surface.
In the present invention, membrane module is hollow-fibre membrane plate membrane or rolled film；By aperture for can be micro-filtration,
Ultrafiltration, nanofiltration, reverse osmosis and forward osmosis membrane component any type.As shown in Figures 2 and 3, using membrane module as board-like positive infiltration
Exemplified by membrane module, the board-like forward osmosis membrane component includes material liquid side cover plate 12, draws liquid side cover plate 22 and FO films 3, described
The inner side of material liquid side cover plate 10 is equipped with material liquid groove 11, material liquid gasket 12, material liquid water inlet 13 and material liquid water outlet
14, it is described draw the inner side of liquid side cover plate 20 and be equipped with draw liquid groove 21, draw fluid cushion piece 22, draw liquid water inlet 23 and draw liquid
Water outlet 24；Exemplified by 6 fiber-optic grating sensors are fixed on 10 medial surface of material liquid side cover plate, 6 fiber gratings
The sensor position mutual with the membrane module and connection relation be, 6 fiber-optic grating sensors are according to along membrane module work
Water (flow) direction when making is arranged in 10 medial surface of material liquid side cover plate, and the bandwidth of the fiber-optic grating sensor 4 is
0.2nm, reflectivity are higher than 90%, grid region length is 10mm and add coating, grating wavelength range 1530nm-1570nm, described
The centre wavelength of fiber-optic grating sensor 4 is only influenced by temperature and strain.Between the grating of adjacent fiber grating sensor 3
It is apart 1cm, the grating wavelength of adjacent fiber grating sensor 4 differs 2~3nm, the grating ripple of 6 fiber-optic grating sensors 3
Long is respectively 1556nm, 1553nm, 1550nm, 1548nm, 1546nm, 1544nm.Each fiber-optic grating sensor is applied
In 0-1mm after prestressing force and with the distance between the film surface of the FO films 3, the material liquid side cover plate 10 or liquid side cover plate is drawn
Fixed between 20 and the fiber-optic grating sensor with UV glue 5；By the material liquid side cover plate 10 and described draw liquid side cover plate
Part 6 is connected with after 20 fastenings to fix, so that 6 fiber-optic grating sensors 4 are fixed with the positive filtration module.6 light
Fiber grating sensor is connected with single mode optical fiber successively；One end of fiber-optic grating sensor after series connection is free end, after series connection
The other end of fiber-optic grating sensor is connected by single mode optical fiber with the input terminal of a fiber Bragg grating (FBG) demodulator；The optical fiber light
The output terminal of grid (FBG) demodulator is connected to a computer, and data acquisition module and data processing mould are provided with the computer
Block.
In the present invention, the fiber Bragg grating (FBG) demodulator 7 uses U.S.'s Micron Optics companies production model as SM130
Dynamic Optical Fiber grating sensing (FBG) demodulator, the data acquisition module use with the U.S. Micron Optics company and and type
Number for SM130 the supporting software of Dynamic Optical Fiber grating demodulation instrument, the data acquiring frequency that the data acquisition module is set is
1-1000 data of collection per second.The data processing module according to the sensing principle of fiber grating by collect above-mentioned 6
The change of the grating wavelength of a fiber-optic grating sensor draws the distribution of stress suffered by the membrane module film surface.
In the present invention, it can also be that the membrane module that more sets are fixed with multiple fiber-optic grating sensors connects to form inspection
Survey array, i.e., stress distribution measuring device suffered by a kind of film surface based on optical fiber grating sensing, including more sets and be fixed with multiple light
The membrane module of fiber grating sensor, membrane module are hollow-fibre membrane plate membrane or rolled film；By its aperture for can be with
It is same in micro-filtration, ultrafiltration, nanofiltration, reverse osmosis and forward osmosis membrane component；Often set is fixed with multiple fiber-optic grating sensors
Membrane module in, the multiple fiber-optic grating sensor position mutual with the membrane module and connection relation are, multiple
Fiber-optic grating sensor is distributed arrangement, multiple optical fiber according to water (flow) direction when working along membrane module and in gallery regional extent
The distance between film surface of grating sensor and the membrane module is in 0-1mm；Between the grating of adjacent fiber grating sensor
Apart from unrestricted, the grating wavelength non-overlapping copies of each fiber-optic grating sensor；Multiple fiber-optic grating sensors use single mode successively
Optical fiber is connected, so as to form a set of membrane module for being fixed with multiple fiber-optic grating sensors；Each set is fixed with multiple optical fiber light
Two free ends of the fiber grating of the membrane module of gate sensor are connected with single mode optical fiber, and connection mode is serial or parallel connection or goes here and there simultaneously
Connection；The one end for the fiber grating that more sets after connection are fixed with the membrane module of multiple fiber-optic grating sensors passes through single-mode optics
Fibre is connected with the input terminal of a fiber Bragg grating (FBG) demodulator；The output terminal of the fiber Bragg grating (FBG) demodulator is connected to a calculating
Machine, data acquisition module and data processing module are provided with the computer, and the data acquisition module uses and the light
The supporting software of fine grating sensing (FBG) demodulator；The data processing module is according to the sensing principle of fiber grating by collecting
The change of the grating wavelength of above-mentioned multiple fiber-optic grating sensors draws the distribution of stress suffered by the membrane module film surface.
It is as follows using the step of stress distribution measuring device measures suffered by the above-mentioned film surface based on optical fiber grating sensing：
Step 1: selection multifiber grating sensor, and the centre wavelength of any two of which fiber-optic grating sensor
Difference is not less than 2nm, and multifiber grating sensor is connected with single mode optical fiber, and the fiber-optic grating sensor after series connection is applied
It is fixed on after prestressing force using UV glue on membrane module, the distance between film surface of multiple fiber-optic grating sensors and the membrane module
In 0-1mm；It is connected, is carried using the fiber Bragg grating (FBG) demodulator soft with the fiber Bragg grating (FBG) demodulator after membrane module is encapsulated
Part measures the quiescent value of the centre wavelength of each fiber-optic grating sensor；
In the present embodiment, 6 fiber-optic grating sensors are connected, are fixed on using the distribution of UV glue on membrane module, make its with
Film surface is in close contact, and can also have the distance less than 1mm between fiber-optic grating sensor and film surface.Adjacent fiber grating sensing
That between device is apart 1cm, and the centre wavelength difference of each fiber-optic grating sensor is not less than 2nm.6 fiber-optic grating sensors
The a reference value of centre wavelength be respectively 1537.88nm, 1539.89nm, 1542.09nm, 1547.94nm, 1550.25nm,
1559.23nm.Fiber bragg grating center wavelength is followed successively by from the near to the remote according to apart from membrane module water inlet distance H：It is at 1cm
Be at 1559.23nm, 2cm be at 1550.25nm, 3cm be to be at 1547.94nm, 4cm at 1537.88nm, 5cm
1539.89nm, at 6cm be 1542.09nm.
Special emphasis is, in the present invention when placing fiber-optic grating sensor, between fiber-optic grating sensor
Distance does not limit, and is typically employed on film surface, the exhaust position of multiple fiber-optic grating sensors uniformly distributed along water (flow) direction,
Can not have to be placed according to centre wavelength is descending successively yet, as long as any two in all fiber-optic grating sensors
Centre wavelength difference be not less than 2nm.
The either end in fiber-optic grating sensor both ends after series connection is free end, and the other end then passes through single mode optical fiber and one
The input terminal of fiber Bragg grating (FBG) demodulator is connected, and fiber Bragg grating (FBG) demodulator use is by Micron Optics companies of U.S. type of production
Number be SM130 Dynamic Optical Fiber grating sensing (FBG) demodulator.The output terminal of fiber Bragg grating (FBG) demodulator is connected to a computer, calculates
Data acquisition module and data processing module are installed in machine, use U.S.'s Micron Optics companies production model as SM130
The supporting software of Dynamic Optical Fiber grating sensing (FBG) demodulator.After membrane module is encapsulated, the quiet of each fiber bragg grating center wavelength is measured
State value be respectively be at 1cm be at 1559.37nm, 2cm be to be at 1550.46nm, 3cm at 1548.09nm, 4cm
It at 1540.20nm, 6cm is 1542.40nm to be at 1538.16nm, 5cm.
Step 2: the water outlet of a water pump is connected with the water inlet of membrane module, enter water to membrane module using the water pump
Mouth water filling, setting flow velocity is more than 0 and is less than 0.5m/s, arrived from childhood in the flow rates and select multiple flow velocitys greatly, according to selected
The circulation of multiple flow velocitys carry out the process of step 3 and step 4, until performing step after completing the data acquisition under multiple flow velocitys
Five；
In the present embodiment, 4 flow velocitys of setting are respectively 0.16m/s, 0.24m/s, 0.32m/s and 0.40m/s.
Step 3: data acquisition module gathers each optical fiber grating sensing with the frequency acquisition of one data of collection per second
Centre wavelength, after optical fiber grating sensing demodulator demodulates the wavelength signals collected, what the fiber Bragg grating (FBG) demodulator carried
Software measures the measured value of the centre wavelength at intervals of each fiber-optic grating sensor of each moment of 1 second in the injecting process in real time.
Step 4: the quiescent value that step 3 is obtained subtracts the measured value of step 1 acquisition, obtain each fiber grating and pass
Measured value of the sensor at intervals of the centre wavelength of each fiber-optic grating sensor of each moment of 1 second；Ask for gained in the collection period
Each fiber-optic grating sensor at intervals of in the measured value of the centre wavelength of each fiber-optic grating sensor of each moment of 1 second
The average value of the changing value of cardiac wave length, the change using the average value as the centre wavelength of each fiber-optic grating sensor in the period
Change value；
In the present embodiment, water pump is passed through current in the water inlet of membrane module, and the flow rate of water flow for setting water inlet is 0.16m/
s.It is located at the fiber-optic grating sensor of film surface diverse location and the stress signal produced due to current scour effect is converted into light
The wavelength signals of fine raster center wavelength change.The wavelength signals that fiber-optic grating sensor perceives middle use through this embodiment
Micron Optics companies of U.S. production model be SM130 Dynamic Optical Fiber grating sensing (FBG) demodulator be demodulated, optical fiber light
The wavelength variation data of acquisition is transported to by Micron Optics companies of U.S. type of production by grid dynamic demodulation instrument by Ethernet
Number data acquisition is carried out for the supporting software of Dynamic Optical Fiber grating sensing (FBG) demodulator of SM130, data acquisition module is adopted with per second
The frequency acquisition of one data of collection, which changes with time the centre wavelength of fiber grating, to be acquired, and obtains optic fiber grating wavelength
The measured value to change with time is 1559.58nm, 1550.82nm at 1cm, 1548.46nm, 1538.63nm,
1540.51nm、1542.62nm。
Above-mentioned 4 flow velocitys 0.16m/s, 0.24m/s, 0.32m/s are identical with a reference value in the case of 0.40m/s but every kind of
Inlet flow rate measures corresponding quiescent value and measured value, and the numerical value of measured quiescent value is all higher than a reference value, related data
Referring to table 1 to table 5.
The numerical value of 6 each centre wavelength of fiber-optic grating sensor when 1. flow velocity of table is 0.16m/s：
The numerical value of 6 each centre wavelength of fiber-optic grating sensor when 2. flow velocity of table is 0.24m/s：
The numerical value of 6 each centre wavelength of fiber-optic grating sensor when 3. flow velocity of table is 0.32m/s：
The numerical value of 6 each centre wavelength of fiber-optic grating sensor when 4. flow velocity of table is 0.40m/s：
The changing value that table 5. obtains lower wavelength different in flow rate is：
Step 5: using mapping software, in the present embodiment, the origin8.0 that OriginLab companies of the U.S. develop is used to make
Figure software, using fiber-optic grating sensor apart from membrane module water inlet distance as abscissa, with step 4 obtain the collection period
The changing value of the centre wavelength of interior each fiber-optic grating sensor be ordinate, draw out gather it is different in flow rate in the period under it is each
The center wavelength variation distribution map of fiber-optic grating sensor, as shown in Figure 4.
Step 6: using step 5 obtain collection the period in it is different in flow rate under each fiber-optic grating sensor middle cardiac wave
Long changing value, according to the sensing principle of light grating obtain it is different in flow rate in the case of stress suffered by film surface distribution situation, film surface
The situation of change of fiber-optic grating sensor centre wavelength is the situation of change of film surface stress at diverse location, finally obtains difference
The distribution situation of stress suffered by film surface diverse location in the case of inlet flow rate, so that further to be carried out to film surface hydraulics situation
Research is laid a good foundation.Its principle is as follows：
Fiber grating has when ambient temperature or strain change, the effective refractive index of fiber core and the week of fiber grating
Phase can all change, so as to cause the change of fiber bragg grating center wavelength, such as formula 1：
ΔλB(αΔT+ξΔT)λB+(Δε-PcΔε)λB (1)
In formula (1)：λB--- raster center wavelength, unit nm；ΔλB--- raster center wavelength variable quantity, unit are
nm；PcFor fiber grating valid elastic-optic constants；Δ ε is strain variation；ζ is fiber grating material thermo-optic coefficients；α is fiber grating
Thermal coefficient of expansion；Δ T is temperature change.
When without considering temperature change, Δ T=0 in formula 1, fiber grating is subject to centre wavelength caused by uniform axial strain
Relative displacement formula is formula (2)：
ΔλB/λB=(1-Pc)Δε (2)
In formula (2), PcFor fiber grating valid elastic-optic constants, formula (3) is represented by：
In formula (3)：μ is the Poisson's ratio of fiber optic materials；P11、P12It is the elasto-optical coefficient of optical fiber；neffFor fiber grating
Effective refractive index.
Germanium-doped silica fiber is selected, each parameter is respectively n in formula (3)eff=1.46, μ=0.16, P11=0.12, P12=
0.27, it is possible thereby to calculate Pc=0.22,
By Pc=0.22, which brings formula (2) into, obtains formula (4)
ΔλB/λB=0.78 Δ ε (4)
Stress causes the change of optic fiber grating wavelength by axial strain that stress produces to realize：
E represents the elasticity modulus of optical fiber in formula (5), is determined by material intrinsic property, is definite value；λBFor the middle cardiac wave of grating
It is long, it is definite value.It is hereby achieved that raster center wavelength change Δ λBWith the linear relationship of stress.
Although above in conjunction with attached drawing, invention has been described, and the invention is not limited in above-mentioned specific implementation
Mode, above-mentioned embodiment is only schematical, rather than restricted, and those of ordinary skill in the art are at this
Under the enlightenment of invention, without deviating from the spirit of the invention, many variations can also be made, these belong to the present invention's
Within protection.
Claims (10)
1. stress distribution measuring device suffered by a kind of film surface based on optical fiber grating sensing, including be fixed on multiple in membrane module
Fiber-optic grating sensor, it is characterised in that：
The multiple fiber-optic grating sensor position mutual with the membrane module and connection relation are multiple fiber gratings
Sensor is distributed arrangement, multiple optical fiber grating sensings according to water (flow) direction when working along membrane module and in gallery regional extent
The distance between film surface of device and the membrane module is in 0-1mm；
The grating wavelength non-overlapping copies of each fiber-optic grating sensor；Multiple fiber-optic grating sensors are connected with single mode optical fiber successively；
One end of fiber-optic grating sensor after series connection is free end, and the other end of the fiber-optic grating sensor after series connection passes through list
Mode fiber is connected with the input terminal of a fiber Bragg grating (FBG) demodulator；
The output terminal of the fiber Bragg grating (FBG) demodulator is connected to a computer, and data acquisition module is provided with the computer
And data processing module, the data acquisition module use the software supporting with the optical fiber grating sensing demodulator；The number
The centre wavelength of the above-mentioned multiple fiber-optic grating sensors collected is passed through according to the sensing principle of fiber grating according to processing module
Change draw the distribution of stress suffered by the membrane module film surface.
2. stress distribution measuring device suffered by a kind of film surface based on optical fiber grating sensing, including more sets are fixed with multiple optical fiber light
The membrane module of gate sensor, it is characterised in that：
Membrane module is hollow-fibre membrane plate membrane or rolled film；
Often set is fixed with the membrane module of multiple fiber-optic grating sensors, the multiple fiber-optic grating sensor and the membrane module
Mutual position and connection relation be, multiple fiber-optic grating sensors according to water (flow) direction when working along membrane module and
The distance between film surface of distribution arrangement in gallery regional extent, multiple fiber-optic grating sensors and the membrane module is in 0-1mm；
The grating wavelength non-overlapping copies of each fiber-optic grating sensor；Multiple fiber-optic grating sensors are connected with single mode optical fiber successively, so that
Form a set of membrane module for being fixed with multiple fiber-optic grating sensors；
Two free ends of the fiber grating of each membrane module for covering and being fixed with multiple fiber-optic grating sensors are connected with single mode optical fiber,
Connection mode is serial or parallel connection or connection in series-parallel；More sets after connection are fixed with the membrane module of multiple fiber-optic grating sensors
One end of fiber grating be connected by single mode optical fiber with the input terminal of a fiber Bragg grating (FBG) demodulator；
The output terminal of the fiber Bragg grating (FBG) demodulator is connected to a computer, and data acquisition module is provided with the computer
And data processing module, the data acquisition module use the software supporting with the optical fiber grating sensing demodulator；The number
The centre wavelength of the above-mentioned multiple fiber-optic grating sensors collected is passed through according to the sensing principle of fiber grating according to processing module
Change draw the distribution of stress suffered by the membrane module film surface.
3. stress distribution measuring device suffered by the film surface according to claim 1 or claim 2 based on optical fiber grating sensing, its feature exist
In the bandwidth of, the fiber-optic grating sensor (4) is 0.2nm, reflectivity is 10mm higher than 90%, grid region length and add coating,
The centre wavelength scope of fiber-optic grating sensor is 1530nm-1570nm, and the centre wavelength of the fiber-optic grating sensor (4) is only
Influenced by temperature and strain.
4. the stress distribution measuring device according to suffered by described in claim 1 or 3 based on the film surface of optical fiber grating sensing, its feature exist
In membrane module is hollow-fibre membrane plate membrane or rolled film.
5. stress distribution measuring device suffered by the film surface according to claim 1 or claim 2 based on optical fiber grating sensing, its feature exist
In the fiber Bragg grating (FBG) demodulator (7) uses Dynamic Optical Fiber grating demodulation instrument.
6. according to claim 5 based on stress distribution measuring device suffered by the film surface of optical fiber grating sensing, it is characterised in that
The data acquisition module uses the software supporting with Dynamic Optical Fiber grating demodulation instrument used, what the data acquisition module was set
Data acquiring frequency is 1-1000 data of collection per second.
7. the stress distribution measuring device according to suffered by described in claim 2 or 4 based on the film surface of optical fiber grating sensing, its feature exist
In the forward osmosis membrane component is board-like forward osmosis membrane component, and the board-like forward osmosis membrane component includes material liquid side cover plate
(12), liquid side cover plate (22) and FO films (3) are drawn, material liquid groove (11), original are equipped with the inside of the material liquid side cover plate (10)
Feed liquid gasket (12), material liquid water inlet (13) and material liquid water outlet (14), described draw are equipped with the inside of liquid side cover plate (20)
Liquid groove (21) is drawn, fluid cushion piece (22) is drawn, draw liquid water inlet (23) and draws liquid water outlet (24)；
The multiple fiber-optic grating sensor position mutual with the membrane module and connection relation be,
Multiple fiber-optic grating sensors are arranged in the material liquid side cover plate according to water (flow) direction when working along membrane module
(10) medial surface or it is described draw liquid side cover plate (20) medial surface, each fiber-optic grating sensor is applied after prestressing force and with
The distance between film surface of the FO films (3) is 0-1mm, the material liquid side cover plate (10) or draws liquid side cover plate (20) and institute
State fixed with UV glue (5) between fiber-optic grating sensor；By the material liquid side cover plate (10) and described draw liquid side cover plate
(20) it is fixed that part (6) is connected with after fastening, so that multiple fiber-optic grating sensors (4) are consolidated with the positive filtration module
It is fixed.
8. according to claim 7 based on stress distribution measuring device suffered by the film surface of optical fiber grating sensing, it is characterised in that
The number of the fiber-optic grating sensor (4) is 6, and between the grating of adjacent fiber grating sensor (3) is apart 1cm,
The grating wavelength of adjacent fiber grating sensor (4) differs 2~3nm.
9. according to claim 7 based on stress distribution measuring device suffered by the film surface of optical fiber grating sensing, it is characterised in that
The grating wavelength of 6 fiber-optic grating sensors (3) be respectively 1556nm, 1553nm, 1550nm, 1548nm, 1546nm,
1544nm。
10. stress distribution measuring method suffered by a kind of film surface based on optical fiber grating sensing, it is characterised in that will using such as right
Ask described in 1 based on stress distribution measuring device suffered by the film surface of optical fiber grating sensing, and comprise the following steps：
Step 1: selection multifiber grating sensor, and the centre wavelength difference of any two of which fiber-optic grating sensor
Not less than 2nm, multifiber grating sensor is connected with single mode optical fiber, the fiber-optic grating sensor after series connection is applied and in advance should
It is fixed on after power using UV glue on membrane module, makes the distance between each fiber-optic grating sensor and film surface in 0-1mm；By film group
It is connected after part encapsulation with the fiber Bragg grating (FBG) demodulator, the software carried using the fiber Bragg grating (FBG) demodulator measures each optical fiber light
The quiescent value of the centre wavelength of gate sensor；
Step 2: the water outlet of a water pump is connected with the water inlet of membrane module, noted using the water pump to the water inlet of membrane module
Water, setting flow velocity, which is more than, 0 and is less than 0.5m/s, arrives multiple flow velocitys selected greatly from childhood in the flow rates, according to selected more
A flow velocity circulation carries out the process of step 3 and step 4, until performing step 5 after completing the data acquisition under multiple flow velocitys；
Step 3: data acquisition module gathers each optical fiber grating sensing with the frequency acquisition of 1-1000 data of collection per second
Centre wavelength, after optical fiber grating sensing demodulator demodulates the wavelength signals collected, what the fiber Bragg grating (FBG) demodulator carried
Software obtains the measured value of the centre wavelength of each fiber-optic grating sensor in real time in the injecting process；
Step 4: the measured value that step 3 is obtained subtracts the quiescent value of step 1 acquisition, each fiber-optic grating sensor is obtained
In the changing value of the centre wavelength at each moment；Each fiber-optic grating sensor of gained in the collection period is asked at each moment
Centre wavelength changing value average value, the centre wavelength using the average value as each fiber-optic grating sensor in the period
Changing value；
Step 5: using mapping software, using fiber-optic grating sensor apart from membrane module water inlet distance as abscissa, with step
The changing value of the centre wavelength of each fiber-optic grating sensor is ordinate in the four collection periods obtained, draws out the collection period
It is interior it is different in flow rate under each fiber-optic grating sensor center wavelength variation distribution map；
Step 6: the centre wavelength of each fiber-optic grating sensor becomes under different in flow rate in the collection period obtained using step 5
Change value, according to the sensing principle of fiber grating obtain it is different in flow rate in the case of stress suffered by film surface distribution situation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711188867.4A CN107966234B (en) | 2017-11-24 | 2017-11-24 | Membrane surface stress distribution measuring device and method based on fiber bragg grating sensing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711188867.4A CN107966234B (en) | 2017-11-24 | 2017-11-24 | Membrane surface stress distribution measuring device and method based on fiber bragg grating sensing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107966234A true CN107966234A (en) | 2018-04-27 |
| CN107966234B CN107966234B (en) | 2020-02-28 |
Family
ID=62000540
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711188867.4A Active CN107966234B (en) | 2017-11-24 | 2017-11-24 | Membrane surface stress distribution measuring device and method based on fiber bragg grating sensing |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107966234B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118310672A (en) * | 2024-06-07 | 2024-07-09 | 苏州南智传感科技有限公司 | Continuous osmotic pressure sensor and working method thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7680363B2 (en) * | 2006-08-15 | 2010-03-16 | Suncall Corporation | Optical pressure sensor |
| CN201662451U (en) * | 2010-04-26 | 2010-12-01 | 同济大学 | Membrane surface tension measuring instrument |
| CN105157900A (en) * | 2015-08-31 | 2015-12-16 | 北京交通大学 | Measurement apparatus of prestress of membrane material |
| CN105352652A (en) * | 2015-09-30 | 2016-02-24 | 南京航空航天大学 | Difference fiber bragg grating baroceptor and method of monitoring airspeed tube dynamic pressure of airplane employing the same |
-
2017
- 2017-11-24 CN CN201711188867.4A patent/CN107966234B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7680363B2 (en) * | 2006-08-15 | 2010-03-16 | Suncall Corporation | Optical pressure sensor |
| CN201662451U (en) * | 2010-04-26 | 2010-12-01 | 同济大学 | Membrane surface tension measuring instrument |
| CN105157900A (en) * | 2015-08-31 | 2015-12-16 | 北京交通大学 | Measurement apparatus of prestress of membrane material |
| CN105352652A (en) * | 2015-09-30 | 2016-02-24 | 南京航空航天大学 | Difference fiber bragg grating baroceptor and method of monitoring airspeed tube dynamic pressure of airplane employing the same |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118310672A (en) * | 2024-06-07 | 2024-07-09 | 苏州南智传感科技有限公司 | Continuous osmotic pressure sensor and working method thereof |
| CN118310672B (en) * | 2024-06-07 | 2024-09-13 | 苏州南智传感科技有限公司 | Continuous osmotic pressure sensor and working method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107966234B (en) | 2020-02-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103669429B (en) | Based on the circular solids concrete pile pile strain monitoring method of FBG sensor | |
| CN102519499B (en) | Based on the quasi-distributed sensor of micro-structure fiber optic Fabry-Perot cavity quasi | |
| CN105043458B (en) | A kind of fibrous composite lightning damage on-line measuring device and method | |
| CN103398800B (en) | A kind of for large structure quasi-distributed fiber grating temperature strain measuring system | |
| Hongo et al. | Applications of fiber Bragg grating sensors and high‐speed interrogation techniques | |
| CN102620858B (en) | Double long period fiber grating (LPFG) temperature and humidity sensor | |
| CN109781240A (en) | Optical fibre vibration sensor phase demodulating device and method based on dual wavelength regression analysis | |
| CN107966234A (en) | Based on stress distribution measuring device and method suffered by the film surface of optical fiber grating sensing | |
| CN110174068A (en) | A kind of sensitizing type Fabry-perot optical fiber microcavity strain transducer and preparation method thereof | |
| CN207540631U (en) | A kind of fiber grating Level monitor | |
| JP2018517908A (en) | Optical fiber pressure device, method and application | |
| CN202191081U (en) | Intelligent bed sheet | |
| CN206192392U (en) | Adopt dry wet process temperature and humidity sensing probe of fiber bragg grating sensor ware | |
| CN105606275A (en) | Online monitoring system and method for core plate of membrane filter board | |
| CN102680134A (en) | Dual-parameter measurement optical fiber grating sensor using chemical corrosion and chemical plating | |
| CN112649052A (en) | Ship body multi-parameter monitoring system and method based on all-fiber grating sensing network | |
| CN110017925B (en) | Waveguide pressure sensor based on M-Z structure and detection method | |
| CN1287127C (en) | Large capacity coding optical fiber grating sensing monitoring system | |
| CN110017926A (en) | A kind of contact-type linear stress sensor and its stress mornitoring method based on micro-loop structure | |
| Yin et al. | Integrated-optics pressure sensor with improved range and sensitivity based on a SiO2 arrayed waveguide grating (AWG) and a 3D printed stereolithography resin module | |
| CN202305070U (en) | Sensor for measuring stress and distortion of polarization maintaining optical fiber based on optical loop mirror | |
| Singh et al. | Simultaneous measurement of strain and temperature using optical fiber sensors: Two novel configuration | |
| CN109374028B (en) | A kind of distributed multiplex demodulating system based on cascade-connection long period fiber grating | |
| CN113340457A (en) | Seawater surface temperature dense profile sensor based on FBG array | |
| CN202281843U (en) | Distributed sensing demodulation system based on tapered fiber gratings |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |