CN202734873U - Optical fiber Bragg grating vortex shedding flowmeter based on triangular prism-shaped vortex generating body - Google Patents
Optical fiber Bragg grating vortex shedding flowmeter based on triangular prism-shaped vortex generating body Download PDFInfo
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- CN202734873U CN202734873U CN201220348378.7U CN201220348378U CN202734873U CN 202734873 U CN202734873 U CN 202734873U CN 201220348378 U CN201220348378 U CN 201220348378U CN 202734873 U CN202734873 U CN 202734873U
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- 239000013307 optical fiber Substances 0.000 title claims abstract description 47
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 claims description 8
- FWQHNLCNFPYBCA-UHFFFAOYSA-N fluoran Chemical compound C12=CC=CC=C2OC2=CC=CC=C2C11OC(=O)C2=CC=CC=C21 FWQHNLCNFPYBCA-UHFFFAOYSA-N 0.000 claims description 6
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims 1
- 229910052802 copper Inorganic materials 0.000 claims 1
- 239000010949 copper Substances 0.000 claims 1
- 239000012530 fluid Substances 0.000 abstract description 26
- 238000005259 measurement Methods 0.000 abstract description 7
- 238000001514 detection method Methods 0.000 abstract description 5
- 239000000126 substance Substances 0.000 abstract description 4
- 238000000034 method Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 238000010892 electric spark Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 239000000835 fiber Substances 0.000 description 3
- 230000008054 signal transmission Effects 0.000 description 3
- 241001124569 Lycaenidae Species 0.000 description 2
- 230000008033 biological extinction Effects 0.000 description 2
- 235000014987 copper Nutrition 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000013178 mathematical model Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
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Abstract
The utility model relates an optical fiber Bragg grating vortex shedding flowmeter based on a triangular prism-shaped vortex generating body and belongs to the technical field of photoelectron measuring. The triangular prism-shaped vortex generating body is fixed in a measuring pipe through bases on two ends. Two lateral faces of the middle portion of the triangular prism-shaped vortex generating body are communicated and form a pressure guide cavity. A free end of an equal strength cantilever beam is provided with a mass block in the pressure guide cavity and a fixation end of the equal strength cantilever beam is connected with an axial conduit in the triangular prism-shaped vortex generating body. An optical fiber Bragg grating is adhered to the central axis of the surface of the equal strength cantilever beam and connected with an external connection optical fiber through the axial conduit and optical fibers. A triangular prism is used by the vortex generating body and provides strong reliability for flow detection. The optical fiber Bragg grating is used as a sensing element, resistant to electromagnetic interference and suitable for measuring fluid of varied types and especially has a good prospect for measurement of chemical corrosive fluid.
Description
Technical field
The utility model relates to a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body, belongs to the photoelectron field of measuring technique.
Background technology
What vortex shedding flow meter was exported is the pulse signal that is directly proportional with rate of flow of fluid, and pulse signal is not subjected to the impact of fluid components, density, pressure, temperature; Range ability is wider, and most of vortex shedding flow meters at Reynolds number are
-
In the scope, applicable pipe diameter generally below 300mm, has the preferably linearity, and range ratio can reach more than the 10:1, the reached 20:1 that has even 30:1.Vortex shedding flow meter can be measured liquid, gas and steam flow, and the degree of accuracy of usually measuring liquid is
, flow rates is 0.5 ~ 7m/s; The degree of accuracy of measurement gas is
, flow rates is 5 ~ 50m/s.
A kind of novel fiber grating vortex flow sensors that the people such as Li Hongmin propose (referring to document: Li Hongmin, high magnificence etc., a kind of novel fiber grating vortex flow sensors, sensing technology journal, 2006 years).This technology forms a cantilever beam structure with pipeline and measures vortex signal by sensing grating being placed the downstream of swirl generating body.This detection mode makes the noise contribution more complicated in the vibration wake flow, and the stable undesired signals such as sub-vortex of the main vortex of many impacts are arranged.
Summary of the invention
The purpose of this utility model provides a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body, adopt triangular prism as swirl generating body, the vortex signal that fluid produces in flowing is strong and stable, for flow detection provides very strong reliability; Adopt optical fiber Bragg raster as sensing element, there are not current supply circuit and output signal, signal transmission is light signal, anti-electromagnetic interference (EMI), can play and prevent that electric spark from producing and explosion-proof, be fit to measure the flow of variety classes fluid, particularly some measurements with chemical corrosivity fluid flow had good application prospect.
Technical solution adopted in the utility model is: a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body comprises triangle column type swirl generating body 1, pedestal 2, measuring tube 3, pilot chamber 4, equi intensity cantilever 6, axial pipe 7, optical fiber Bragg raster 8, external optical fiber 9 and optical fiber fairlead 10; Triangle column type swirl generating body 1 is fixed in the measuring tube 3 by the pedestal 2 at two ends, two sides, triangle column type swirl generating body 1 middle part communicate, form pilot chamber 4, in pilot chamber 4, the free end of equi intensity cantilever 6 is with mass 5, and the stiff end of equi intensity cantilever 6 is connected with triangle column type swirl generating body inner shaft conductive pipe 7; Optical fiber Bragg raster 8 sticks on the central axis on equi intensity cantilever 6 surfaces, and optical fiber Bragg raster 8 is connected with external optical fiber 9 with optical fiber fairlead 10 by axial pipe 7.
The cross sectional shape of triangle column type swirl generating body 1 is that an isosceles triangle is clipped three isosceles polygons behind the angle, and the bottom surface 11 of triangle column type swirl generating body is as fluoran stream surface, and the base 12 of triangle column type swirl generating body faces toward to come flow path direction; The short seamed edge 13 that is parallel to central axis is arranged in the both sides of triangle column type swirl generating body.
The free end of equi intensity cantilever 6 with mass 5 adopt metallic coppers to make.
The beneficial effects of the utility model are: the utility model adopts triangular prism as swirl generating body, and the vortex signal that fluid produces in flowing is strong and stable, for flow detection provides very strong reliability; Adopt optical fiber Bragg raster as sensing element, there are not current supply circuit and output signal, signal transmission is light signal, anti-electromagnetic interference (EMI), can play and prevent that electric spark from producing and explosion-proof, be fit to measure the flow of variety classes fluid, particularly some measurements with chemical corrosivity fluid flow had good application prospect.
Description of drawings
Fig. 1 is structural representation of the present utility model;
Fig. 2 is triangular prism swirl generating body structural representation of the present utility model;
Fig. 3 is the pilot chamber sectional view of triangle column type swirl generating body of the present utility model;
Among the figure: 1-triangle column type swirl generating body, 2-pedestal, 3-measuring tube, 4-pilot chamber, 5-mass, 6-equi intensity cantilever, 7-axial pipe, 8-optical fiber Bragg raster, the external optical fiber of 9-, 10-optical fiber fairlead.
Embodiment
As shown in Figure 1: triangle column type swirl generating body 1 is fixed in the measuring tube 3 by the pedestal 2 at two ends, two sides, triangle column type swirl generating body 1 middle part communicate, form pilot chamber 4, in pilot chamber 4, the free end of equi intensity cantilever 6 is with mass 5, and the stiff end of equi intensity cantilever 6 is connected with triangle column type swirl generating body inner shaft conductive pipe 7; Optical fiber Bragg raster 8 sticks on the central axis on equi intensity cantilever 6 surfaces, and optical fiber Bragg raster 8 is connected with external optical fiber 9 with optical fiber fairlead 10 by axial pipe 7.
Shown in Fig. 2,3: the cross sectional shape of triangle column type swirl generating body 1 is that an isosceles triangle is clipped three isosceles polygons behind the angle, the bottom surface 11 of triangle column type swirl generating body is as fluoran stream surface, and the base 12 of triangle column type swirl generating body faces toward to come flow path direction; In the both sides of triangle column type swirl generating body the short seamed edge 13 that is parallel to central axis is arranged, short seamed edge 13 has worked two: the one, and force vortex to produce separated in synchronization at this; The 2nd, separation has certain stabilization to vortex.
The free end of equi intensity cantilever 6 with mass 5 adopt metallic coppers to make, its effect is the deformation that increases semi-girder.
The using method of described a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body, flow in the measuring tube is crossed triangle column type swirl generating body 1, vortex can alternately be isolated in both sides at triangle column type swirl generating body, there is a side static pressure of vortex to increase, fluid is pressed into pilot chamber 4, produce pulsating fluid in the pilot chamber, pulsating fluid is applied to the free end of equi intensity cantilever 6, cause sticking on the optical fiber Bragg raster 8 periodic wave long shifts on its centre of surface axis, by the frequency measurement to optical fiber Bragg raster 8 wavelength-shifts, can measure vortex shedding frequency
f, according to formula
(wherein,
SrBe Strouhal number,
DBe the measuring tube internal diameter,
D isTriangular prism artificial body for generating fluoran stream surface width,
M isThe ratio of the arc circulation area sum in triangular prism artificial body for generating both sides and the cross-sectional area of measuring tube), can calculate the flow of fluid.
The mathematical model of the utility model measuring technique is as follows:
The mean flow rate of vortex frequency f and the artificial body for generating both sides of flowing through
U 1Between relation can be expressed as:
f =Sr U 1 /d （1）
In the formula,
fBe vortex frequency, the Hz of unit;
SrBe Strouhal number;
U 1Be the mean flow rate of artificial body for generating both sides, the m/s of unit;
dBe the width of artificial body for generating fluoran stream surface, the m of unit.
If the measuring tube internal diameter is
D, the arc circulation area sum in artificial body for generating both sides with the ratio of the cross-sectional area of measuring tube is
m, then
According to the fluid continuity theorem:
U 1=
U/m （3）
In the formula
UBe the mean flow rate in the measuring tube, m/s.
Get with formula (3) substitution formula (1)
If instantaneous volume flow rate is in the measuring tube
, then
Can find out from formula (5), for the measuring tube internal diameter of determining
DWith artificial body for generating fluoran stream surface width
d, the state volumetric flow rate of fluid
With vortex frequency
fBe directly proportional.Therefore, as long as measure vortex frequency
f, just can measure fluid flow.Analyze the frequency of optical fiber Bragg raster wavelength-shift according to the spectrum (FBG) demodulator, namely obtained the cross frequence of vortex, and then can obtain the flow of fluid.
The lift that equi intensity cantilever in the middle of the swirl generating body pilot chamber is subject to is:
（6）
Wherein
Lift coefficient,
The density of fluid.
The wavelength-shift that the even axial strain of optical fiber Bragg raster causes is:
In the formula (1),
Be the centre wavelength of optical fiber Bragg raster,
Be the wavelength-shift amount,
=0.22 is valid round-backscatter extinction logarithmic ratio,
Be the axial strain amount.
Equi intensity cantilever is subject to the lift effect to be had:
Wherein
EBe the elastic modulus of semi-girder material,
H, l, BRespectively the thickness of semi-girder, length and width.
Embodiment
Design parameter in actual fabrication is:
1. measuring tube: steel pipe, Young's modulus of elasticity
GPa, Poisson ratio
Internal diameter 100mm, external diameter 110mm.
2. equi intensity cantilever size: length
l=15mm, thickness 1mm, width 20mm.
3. artificial body for generating width: 28mm.
4. artificial body for generating total length on flow direction: 35mm.
5. the length of artificial body for generating parallel sided seamed edge: 3mm.
6. triangular prism xsect drift angle partly: 19 °.
7. artificial body for generating susceptor diameter: 41.1mm
8. artificial body for generating pedestal end distance is from 90mm.
9. measuring tube and pedestal gap: 0.66mm.
10. the gap depth between measuring tube and pedestal: 6.6mm.
11. optical fiber Bragg raster technical parameter: centre wavelength
Nm, the valid round backscatter extinction logarithmic ratio
12. fluid is selected tap water, mean flow rate is chosen 10m/s in the pipeline;
13. press accompanying drawing 1 and accompanying drawing 2 configuration experiments;
14. obtain the Bragg wavelength of optical fiber Bragg raster with the fiber grating analyser;
According to formula (5) (6) (7) (8), the Bragg wavelength-shift fluid flow of optical fiber Bragg raster
Response sensitivity be:
Get Sr=0.25, E=200GPa,
=1, theory can be calculated: when internal diameter of the pipeline was 100mm, the sensitivity of this flowmeter was 0.48pm/ (m3/h); The flow measurement range of this flowmeter is: 14.13m3/h ~ 282.6 m3/h.
The utility model adopts triangular prism as swirl generating body, and the vortex signal that fluid produces in flowing is strong and stable, for flow detection provides very strong reliability; Simultaneously, because sensing grating is built in the triangle column type swirl generating body 1, can arrive strong vortex signal by direct feeling, signal to noise ratio (S/N ratio) is very high; At the middle part of artificial body for generating pilot chamber 4 is set, can prevents well that some solid impurities in the fluid to the damage of senser element, having played certain protective effect, and safeguard simply, increased the serviceable life of flowmeter; Sensing grating sticks on the comparatively responsive equi intensity cantilever 6 of micro-stress, as long as the effect of the pulsating fluid that equi intensity cantilever 6 produces when being subject to the vortex generation, obvious deformation will occur in equi intensity cantilever 6, optical fiber Bragg raster 8 wavelength will produce comparatively significantly wavelength-shift, have improved the accuracy of measuring; Adopt optical fiber Bragg raster 8 as sensing element, there are not current supply circuit and output signal, signal transmission is light signal, anti-electromagnetic interference (EMI), can play and prevent that electric spark from producing and explosion-proof, be fit to measure the flow of variety classes fluid, particularly some measurements with chemical corrosivity fluid flow had good application prospect.
The utility model describes by specific implementation process, without departing from the present invention, can also carry out various conversion and be equal to replacement patent of the present invention, therefore, the utility model patent is not limited to disclosed specific implementation process, and should comprise the whole embodiments that fall in the utility model Patent right requirement scope.
Claims (3)
1. optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body, it is characterized in that: flowmeter comprises triangle column type swirl generating body, pedestal, measuring tube, pilot chamber, equi intensity cantilever, axial pipe, optical fiber Bragg raster, optical fiber fairlead and external optical fiber; Triangle column type swirl generating body is fixed in the measuring tube by the pedestal at two ends, and two sides, triangle column type swirl generating body middle part communicate, and form the pilot chamber; In the pilot chamber, the free end of equi intensity cantilever is with mass, and the stiff end of equi intensity cantilever is connected with triangle column type swirl generating body inner shaft conductive pipe; Optical fiber Bragg raster sticks on the central axis on equi intensity cantilever surface, and optical fiber Bragg raster is connected with external optical fiber with the optical fiber fairlead by axial pipe.
2. a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body according to claim 1, it is characterized in that: the cross sectional shape of triangle column type swirl generating body is that an isosceles triangle is clipped three isosceles polygons behind the angle, the bottom surface of triangle column type swirl generating body is as fluoran stream surface, and the base of triangle column type swirl generating body faces toward to come flow path direction; The short seamed edge that is parallel to central axis is arranged in the both sides of triangle column type swirl generating body.
3. a kind of optical fiber Bragg raster vortex shedding flow meter based on triangle column type swirl generating body according to claim 1 is characterized in that: the free end of equi intensity cantilever with mass adopt metallic copper to make.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220348378.7U CN202734873U (en) | 2012-07-18 | 2012-07-18 | Optical fiber Bragg grating vortex shedding flowmeter based on triangular prism-shaped vortex generating body |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201220348378.7U CN202734873U (en) | 2012-07-18 | 2012-07-18 | Optical fiber Bragg grating vortex shedding flowmeter based on triangular prism-shaped vortex generating body |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768048A (en) * | 2012-07-18 | 2012-11-07 | 昆明理工大学 | Fiber Bragg grating vortex shedding flow meter based on triangular prism-shaped vortex-forming body and using method thereof |
| CN105699690A (en) * | 2016-01-28 | 2016-06-22 | 山东省科学院激光研究所 | A vortex street wind speed sensor based on fiber gratings and an assembly method thereof |
-
2012
- 2012-07-18 CN CN201220348378.7U patent/CN202734873U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102768048A (en) * | 2012-07-18 | 2012-11-07 | 昆明理工大学 | Fiber Bragg grating vortex shedding flow meter based on triangular prism-shaped vortex-forming body and using method thereof |
| CN105699690A (en) * | 2016-01-28 | 2016-06-22 | 山东省科学院激光研究所 | A vortex street wind speed sensor based on fiber gratings and an assembly method thereof |
| CN105699690B (en) * | 2016-01-28 | 2018-09-28 | 山东省科学院激光研究所 | A kind of vortex street air velocity transducer and its assemble method based on fiber grating |
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| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130213 Termination date: 20150718 |
|
| EXPY | Termination of patent right or utility model |