CN201787974U - Side-induction differential processing type dual bluff body vortex flowmeter - Google Patents
Side-induction differential processing type dual bluff body vortex flowmeter Download PDFInfo
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- CN201787974U CN201787974U CN2010201057362U CN201020105736U CN201787974U CN 201787974 U CN201787974 U CN 201787974U CN 2010201057362 U CN2010201057362 U CN 2010201057362U CN 201020105736 U CN201020105736 U CN 201020105736U CN 201787974 U CN201787974 U CN 201787974U
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- 238000012545 processing Methods 0.000 title claims abstract description 26
- 230000009977 dual effect Effects 0.000 title abstract 2
- 230000006698 induction Effects 0.000 claims description 5
- 239000012530 fluid Substances 0.000 abstract description 17
- 230000010355 oscillation Effects 0.000 abstract description 6
- 238000006243 chemical reaction Methods 0.000 abstract description 3
- 238000000034 method Methods 0.000 abstract 1
- 238000005259 measurement Methods 0.000 description 5
- 238000009434 installation Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
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- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
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Abstract
The utility model discloses a side-induction differential processing type dual bluff body vortex flowmeter. A front bluff body and a rear bluff body which are respectively perpendicular to the axial line of a pipeline and provided with non-streamline transverse cross-sections are respectively mounted in the pipeline, wherein sensors are respectively mounted in the symmetrical positions where the side surface of the rear bluff body is parallel to the planes where the axial lines of the two bluff bodies are, and the axial lines of the two sensors are respectively parallel to the axial line of the rear bluff body; the Karman vortex generated by the fluid downstream the front bluff body and capable of periodically shedding in a staggered manner flows through the rear bluff body and then is excited for second time to obtain more stable secondary Karman vortex with more powerful vibration, so that the metering lower limit of the flowmeter is lowered; a fluid oscillation signal and a common-mode interference signal with same frequency, similar amplitude and phase difference of 180 degrees are respectively measured by the two sensors; and since the sensing films for the sensors are horizontally placed, the component of the fluid oscillation signal on the horizontal shaft is synchronously enhanced during the differential processing process, simultaneously, the common-mode interference signal is suppressed, and a secondary instrument performs conversion treatment to the signal to obtain flow information.
Description
Technical field
The utility model relates to a kind of device of measuring fluid flow, especially relates to the two bluff body vortex shedding flow meters of a kind of side induction difference processing formula.
Background technology
When fluid is flowed through the blunt form bluff body, producing two vortexs of showing rule in the downstream of bluff body is Karman vortex street, follow the generation of vortex and alternately come off, around bluff body and fluid downstream will produce clocklike and vibrate, there are corresponding relation in its vibration frequency and flow.Utilize the vortex shedding flow meter of this principle development to obtain using more widely at home and abroad.
The principal character of existing vortex shedding flow meter is that cross section of installation is blunt form and symmetrical bluff body in runner, in bluff body or its downstream installation and measuring element, utilize secondary instrument that detected vortex is come off or the fluid oscillation signal is handled, and be converted to the flow of fluid by instrument coefficient.There is two large problems in existing vortex shedding flow meter: 1, measurable flux lower limit is higher.Vortex shedding flow meter requires to measure in certain flow rates, the frequency that vortex comes off is relevant with Strouhal number (Strouhal Number), concern as follows: (f is for stablizing the frequency that vortex comes off for f=(v/d) St, St is a Strouhal number, v is the flow velocity of detected fluid, d is that the post of bluff body is wide), studies show that Strouhal number is the function of Reynolds number in the certain flow scope, the flow velocity of detected fluid and the frequency that vortex comes off satisfy proportional relation at this moment, but Reynolds number hour, fluid oscillation is very faint, signal to noise ratio (S/N ratio) can not satisfy the detection requirement, the metering lower limit of therefore existing vortex shedding flow meter generally is taken at about reynolds number Re=2000, has greatly limited the measures range of flowmeter.2, interference free performance is poor.Vortex shedding flow meter is the measurement that utilizes fluid self vibration realizing fluid, and treat that the pressure fluctuation or extraneous vibration source and the noise source that exist in the examining system also can cause the vibration for the treatment of fluid in the examining system, the vibration signal that these are external, or change vortex vibration frequency, or directly enter secondary instrument, can cause error in dipping.All employing levels of existing vortex shedding flow meter two sensors are installed, and when this makes that carrying out signal differential handles, only can eliminate the external vibration signal of vertical direction, and influence that can not elimination of level direction extraneous interference.
Summary of the invention
The purpose of this utility model is to provide flow measurement lower limit a kind of side induction difference processing formula lower, that interference free performance is high two bluff body vortex shedding flow meters.
The technical scheme that its technical matters that solves the utility model adopts is:
It comprises pipeline, preceding bluff body, back bluff body, two sensors, signal differential processing module and flowmeter secondary instruments the utility model; In pipeline, be equipped with perpendicular to conduit axis, its xsect is the preceding bluff body and the back bluff body of blunt form, be equipped with at the side of bluff body, back and parallel plane symmetric position place, two bluff body axis places the first sensor and second sensor are housed respectively, the first sensor and second sensor are transported to the signal differential processing module by circuit with induced signal respectively, the signal differential processing module again by the signal conveys of circuit after with difference processing to the flowmeter secondary instrument; The axis of the described first sensor and second sensor respectively with the back bluff body axis be parallel to each other.
Be 0.6DN～1.5DN apart between bluff body and the back bluff body end face before described, wherein DN is the diameter of pipeline, and the shape of cross section of two blunt form bluff bodies is
Shape,
Shape,
Shape or
Shape.
Described two sensors are piezoelectric film sensor.
The beneficial effect that the utlity model has is:
1, utilize two bluff body unitized constructions of optimizing to cause the overlapping phenomenon of vortex, can obtain stable more, the stronger fluid oscillation signal of vibration, make under the identical situation of Reynolds number, descended 2～4 times with the fluid-velocity survey lower limit of the linear corresponding relation of vibration frequency, the comparable existing vortex shedding flow meter of fluid-velocity survey scope of responding to the two bluff body vortex shedding flow meters of difference processing formula by the side of this principle design significantly enlarges.
2, the vibration signal that arrives of sensor measurement is after handling through amplification, filtering, shaping, carry out difference processing and conversion by secondary instrument again, make common mode interference signal be suppressed, put owing to sensor sensing pellicular water safety simultaneously, make and strengthened synchronously when the component of vibration signal on transverse axis carries out difference processing, obtain flow information, can effectively improve the flow measurement accuracy of measurement and reduce the metering lower limit.
Description of drawings
Fig. 1 is a structured flowchart of the present utility model.
Fig. 2 is that two sensors are installed cut-open view among Fig. 1.
Fig. 3 is a various bluff body cross-sectional view of the present utility model.
Among the figure: 1. pipeline, 2. before bluff body, 3. back bluff body, 4. sensor, 5. sensor, 6. outlet line, 7. signal differential processing module, 8. flowmeter secondary instrument.
Embodiment
Below in conjunction with drawings and Examples the utility model is further specified.
As shown in Figure 1 and Figure 2, it comprises pipeline 1, preceding bluff body 2, back bluff body 3, two sensors 4,5, signal differential processing module 7 and flowmeter secondary instrument 8 the utility model; In pipeline 1, be equipped with perpendicular to conduit axis, its xsect is the preceding bluff body 2 and the back bluff body 3 of blunt form, be equipped with at the side of bluff body 3, back and parallel plane symmetric position place, two bluff body axis places the first sensor 4 and second sensor 5 are housed respectively, the first sensor 4 and second sensor 5 are transported to signal differential processing module 7 by circuit 6 with induced signal respectively, signal differential processing module 7 again by the signal conveys of circuit after with difference processing to flowmeter secondary instrument 8; The axis of the described first sensor 4 and second sensor 5 respectively with the back bluff body 3 axis be parallel to each other.
As Fig. 1, shown in Figure 3, at a distance of being 0.6DN～1.5DN, wherein DN is the diameter of pipeline 1 between described preceding bluff body 2 and back bluff body 3 end faces, and the shape of cross section of two blunt form bluff bodies is
Shape,
Shape,
Shape or
Shape.Optimum distance between preceding bluff body 2 and back bluff body 3 end faces is by bluff body before changing 2 and back bluff body 3 end distance experimental verification gained results.
Described two sensors are piezoelectric film sensor.
Principle of work of the present utility model is as follows:
Former and later two bluff bodies of blunt form xsect are housed in pipeline, in the symmetria bilateralis position in bluff body downstream, back two piezoelectric film sensors are housed, two sensors are connected with secondary instrument by circuit respectively.The Karman vortex street that the cycle staggering that is produced in preceding bluff body downstream by fluid comes off is inspired secondly behind the back bluff body of flowing through and obtains stable more, the stronger secondary Karman vortex street of vibration, to reduce the metering lower limit of flowmeter.Two sensors measures respectively that frequency is identical, amplitude is approaching, the fluid oscillation signal and the common mode interference signal of 180 ° of phase phasic differences.Two sensor to vibration signal can be decomposed into the vibration signal of level and vertical both direction, in secondary instrument, carry out difference processing and conversion, make common mode interference signal be suppressed.Because two sensors is vertically laid, the sensor film of two piezoelectric film sensors is parallel with surface level, and gained vibration signal its component on transverse axis when signal differential is subsequently handled is strengthened synchronously, has avoided being twisted reinforcement.To remove the strengthened effective vibratory impulse signal of noise and amplitude and offer the flowmeter secondary instrument, to obtain the metering lower limit of the higher flowmeter of precision.
Claims (3)
1. the two bluff body vortex shedding flow meters of difference processing formula are responded in a side, and it comprises pipeline (1), preceding bluff body (2), back bluff body (3), two sensors (4,5), signal differential processing module (7) and flowmeter secondary instrument (8); In pipeline (1), be equipped with perpendicular to conduit axis, its xsect is the preceding bluff body (2) and the back bluff body (3) of blunt form, be equipped with first sensor (4) and second sensor (5) be housed respectively at side and parallel plane symmetric position place, two bluff body axis places at back bluff body (3), first sensor (4) and second sensor (5) are transported to signal differential processing module (7) by circuit (6) with induced signal respectively, signal differential processing module (7) again by the signal conveys of circuit after with difference processing to flowmeter secondary instrument (8); It is characterized in that: the axis of described first sensor (4) and second sensor (5) respectively with the back bluff body (3) axis be parallel to each other.
2. the two bluff body vortex shedding flow meters of a kind of side induction difference processing formula according to claim 1, it is characterized in that: be 0.6DN～1.5DN apart between bluff body (2) and back bluff body (3) end face before described, wherein DN is the diameter of pipeline (1).
3. the two bluff body vortex shedding flow meters of a kind of side induction difference processing formula according to claim 1, it is characterized in that: described two sensors are piezoelectric film sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201057362U CN201787974U (en) | 2010-01-26 | 2010-01-26 | Side-induction differential processing type dual bluff body vortex flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201057362U CN201787974U (en) | 2010-01-26 | 2010-01-26 | Side-induction differential processing type dual bluff body vortex flowmeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201787974U true CN201787974U (en) | 2011-04-06 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010201057362U Expired - Fee Related CN201787974U (en) | 2010-01-26 | 2010-01-26 | Side-induction differential processing type dual bluff body vortex flowmeter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201787974U (en) |
-
2010
- 2010-01-26 CN CN2010201057362U patent/CN201787974U/en not_active Expired - Fee Related
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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: 20110406 Termination date: 20170126 |
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| CF01 | Termination of patent right due to non-payment of annual fee |