CN115342889A - Method for correcting meter coefficient of flowmeter under water-air medium and flowmeter - Google Patents
Method for correcting meter coefficient of flowmeter under water-air medium and flowmeter Download PDFInfo
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Abstract
The invention provides a correction method of meter coefficients of a flowmeter under a water-air medium and a flowmeter, belonging to the technical field of instruments and meters.
Description
Technical Field
The invention belongs to the technical field of instruments and meters, relates to a flowmeter technology for metering, and particularly relates to a meter coefficient correction technology of a Karman vortex shedding flowmeter under a water-air medium by utilizing calibration test results under different media and based on numerical fitting, in particular to a method for correcting the meter coefficient of the flowmeter under the water-air medium and a flowmeter.
Background
Energy conservation and consumption reduction are key focus indexes of energy utilization at present, and accurate air metering plays a key role in promoting energy conservation and consumption reduction, improving product quality and improving the energy management level of enterprises. However, the flow meter is influenced by various factors such as air state, physical properties, design, installation and use of the flow meter, and the like in the metering process, so that the metering accuracy of the flow meter in the actual metering process on site is difficult to accurately guarantee.
At present, the flow standard device for tracing the karman vortex street flow metering value is mainly divided into three types according to the media types: the first type is a steam real flow standard device which takes steam as a verification/calibration medium; the second type is a water flow standard device using water as a medium; the third type is a gas flow rate standard device using atmospheric air as a medium. The Karman vortex street flowmeter for measuring steam on site is generally verified/calibrated by using water, atmospheric air or air medium, but the water, the atmospheric air and the steam have great difference in temperature, pressure, density, viscosity and the like, so that when the water and the atmospheric air are verified/calibrated mutually, the verification/calibration coefficient has 1.5-3% difference, and the formed correction error after verification/calibration is very large.
Disclosure of Invention
The invention provides a method for correcting a flow meter coefficient under a water-air medium and a flow meter, aiming at the problem that the correction error formed after verification/calibration is very large due to the difference of verification/calibration coefficients when water and normal pressure air are used for mutual verification/calibration in the prior art.
The correction factor mathematical model of the instrument coefficient under the water-air medium is established, and the fitting constant in the correction factor mathematical model is determined by using a numerical fitting method, so that the correction method has the advantages of high reliability, good safety and convenience in operation; the specific technical scheme is as follows:
the method for correcting the coefficient of the flowmeter under the water-air medium comprises the following steps:
1) Selecting vortex shedding flowmeters with various calibers;
2) Calculating a geometric parameter variable beta corresponding to the vortex shedding flowmeter with each caliber;
3) Under a standard medium, a plurality of flow points are selected by the vortex shedding flowmeter with each caliber, and the Reynolds number Re of each flow point is determined Steam generating device (i)，iIs the total number of flow points;
4) Based on the Reynolds number similarity principle, the Reynolds number Re of each flow point Standard of merit (i) Determining Reynolds number Re at each flow point in aqueous medium Water (W) (i) And Reynolds number Re for each flow point in air medium Air (a) (i)；
5) According to the caliber of the vortex shedding flowmeter and the Reynolds number Re of each flow point Water (I) (i) Determining the mass flow q of each flow point in an aqueous medium set-water (i) According to the diameter of the vortex shedding flowmeter and the Reynolds number Re of each flow point Air (a) (i) Determining the mass flow q per flow point under an air medium set-air (i)；
6) According to q set-water (i) Measuring the gauge pressure p corresponding to each flow point under the aqueous medium 1 Water （i,j) The unit is: kPa, gauge back pressure p 2 water （i,j) The unit is: kPa, standard cumulative volume V Water (I) （i,j) The unit is: l, and an accumulation pulse N Water (I) （i,j) The unit: a plurality of; wherein the gauge front pressure p 1 Water （i,j) Gauge back pressure p 2 water （i,j) Standard cumulative volume V Water (W) （i,j) And accumulating pulse N Water (W) （i,j) All measurements are carried out for a plurality of times;
according to q set-air (i) Measuring the gauge pressure p corresponding to each flow point under the air medium 1 air of （i,j) The unit: kPa, gauge back pressure p 2 air (air) （i,j) The unit: kPa, standard cumulative volume V Air (W) （i,j) The unit: l, and an accumulation pulse N Air (a) （i, j) The unit is: a plurality of; wherein the gauge front pressure p 1 air of （i,j) Gauge back pressure p 2 air (air) （i,j) Standard cumulative volume V Air (a) （i,j) And accumulating pulse N Air (W) （i,j) Measuring for multiple times;
wherein i is the total number of flow points, and j is the number of times of measurement of each flow point;
7) Calculating the average gauge pressure p corresponding to each flow point in the aqueous medium 1 Water (i) Average post gauge pressure p corresponding to each flow point 2 water (i)；
Calculating the average gauge pressure p corresponding to each flow point under the air medium 1 air of (i) Average post gauge pressure p corresponding to each flow point 2 air of (i)；
8) Respectively calculating the instrument coefficients K under the water medium and the air medium Water (I) （i,j) And K Air (W) （i,j) The calculation formula is as follows:
K air (a) （i,j）=N Air (a) （i,j）/V Air (a) （i,j）*1000
K Water (I) （i,j）=N Water (W) （i,j）/V Water (W) （i,j）*1000
According to K Air (a) （i,j) And K Water (I) （i,j) Respectively calculating the average meter coefficient K under the water medium Water (W) (i) And average gauge coefficient under air medium K Air (W) (i)；
9) Establishing a correction factor mathematical model of instrument coefficients under a water-air medium:
K air (a) (i)= K Water (I) (i)/ε
Wherein,
for the correction factors, a, b and c are all fitting constants,
the vortex shedding flowmeter with each caliber corresponds to a geometric parameter variable which is dimensionless;
is an air isentropic adiabatic index which is dimensionless; p is a radical of 1 Equal to the mean pre-gauge pressure p under an air medium 1 air of (i)，p 2 Equal to the mean gauge-rear pressure p in air medium 2 air (air) (i)；
And correcting the flow meter coefficient under the water-air medium according to the correction factor mathematical model.
Further, the fitting constants a, b and c in step 9) are calculated in the following manner:
setting up
，
Can obtain the product
Calculating under different calibers and different flow points
Value, will be under different calibers, different flow points
Fitting calculation is carried out on the values to obtain the values of a, b and c.
Further limiting, in the step 2), a calculation formula of a geometric parameter variable β corresponding to each caliber of the vortex shedding flowmeter is as follows:
wherein d (b) is the characteristic width of the generator, unit: mm; d (b) is the inner diameter of the vortex shedding flowmeter, unit: mm and b are the caliber of the vortex shedding flowmeter and the unit is as follows: mm.
Further limiting, in the step 1), at least 3 kinds of calibers of the vortex shedding flowmeter are selected.
Further limiting, in the step 3), the number of the flow points of the vortex shedding flowmeter with each caliber is more than or equal to 4.
Further limiting, in the step 4), the Reynolds number Re of each flow point Water (W) (i) The Reynolds number of the flow velocity is not lower than the Reynolds number of the lowest flow velocity under the corresponding caliber and is not higher than the Reynolds number of the highest flow velocity under the corresponding caliber; reynolds number Re for each flow point Air (a) (i) The Reynolds number of the lowest flow velocity under the corresponding caliber is not lower than the Reynolds number of the highest flow velocity under the corresponding caliber.
Further, in the step 3), the standard medium is a steam medium.
The flowmeter is obtained by correcting the coefficient of the flowmeter under the water-air medium by using the method for correcting the coefficient of the flowmeter.
Compared with the prior art, the invention has the beneficial effects that:
according to the correction method for the meter coefficient of the flowmeter under the water-air medium, the calibration of the air Karman vortex shedding flowmeter by a water device is realized through the mutual correction relationship of the calibration coefficients of the Karman vortex shedding flowmeter under the water medium and the air medium, so that the traceability cost control and the accurate metering of air energy under the existing equipment are realized, and the calibration/calibration correction error of the vortex shedding flowmeter is reduced; the effective maximum utilization of standard resources is realized, and huge economic loss and personnel potential safety hazards caused by air detection are avoided; the method has important significance for improving the metering guarantee capability and the detection capability of the vortex shedding flowmeter. The tracing accuracy of the Karman vortex shedding flowmeter under the air medium is realized.
The calibration error of the air Karman vortex shedding flowmeter can be controlled to be below 0.5% after correction by establishing a correction factor mathematical model of instrument coefficients under a water-air medium and determining a fitting constant in the correction factor mathematical model by using a numerical fitting method, and correcting the air Karman vortex shedding flowmeter calibrated by a water device, so that the calibration/calibration error of the air Karman vortex shedding flowmeter is greatly reduced.
Drawings
FIG. 1 is a process schematic diagram of a method for correcting the coefficient of a flowmeter under a water-air medium according to the present application;
fig. 2 is a schematic diagram of measurement of the characteristic width of the shedder in the present application.
Detailed Description
The technical solutions of the present invention will be further explained below with reference to the drawings and examples, but the present invention is not limited to the embodiments explained below.
According to the correction method for the meter coefficient of the flowmeter under the water-air medium, the calibration of the air Karman vortex shedding flowmeter by the water device is realized through the mutual correction relation of the calibration coefficients of the Karman vortex shedding flowmeter under the water medium and the air medium, so that the traceability cost control and the accurate metering of the air energy under the existing equipment are realized.
Example 1
Referring to fig. 1, the method for correcting the meter coefficient of the flow meter under the water-air medium of the embodiment includes the following steps:
1) Selecting vortex shedding flowmeters with various calibers, wherein 8 vortex shedding flowmeters of 4 different brands are selected in the embodiment, the precision grades are 1.5 grades, and the precision grades comprise calibers DN (50), DN (100), DN (150) and DN (200), and two of each calibers are included;
2) Calculating geometric parameter variables beta corresponding to vortex shedding flowmeters with different calibers, wherein the beta is dimensionless, and the calculation formula of the geometric parameter variables beta corresponding to the vortex shedding flowmeters is as follows:
referring to fig. 2, where d (b) is the shedder feature width, in units: mm; d (b) is the inner diameter of the vortex shedding flowmeter, and the unit is as follows: mm, b is the caliber of the vortex shedding flowmeter, unit: mm;
referring to table 1, the geometric parameter variable β calculated for the 8 vortex shedding flowmeters in step 1),
table 1: geometric parameter variable corresponding to vortex shedding flowmeters with different calibers
3) Under a standard medium, a plurality of flow points are selected by the vortex shedding flowmeter with each caliber, and the Reynolds number Re of each flow point is determined Standard of merit (i)，iIs the total number of flow points; specifically, the standard medium here is a steam medium, and may also be other media besides the steam medium, for example: an aqueous medium or an air medium;
in this embodiment, a standard medium is taken as an example of a vapor medium, and specifically, under the vapor medium, 8 flow points are selected for each caliber of the vortex shedding flowmeter:q max 、0.8q max 、0.6q max 、0.4q max 、0.3q max 、0.2q max 、0.15q max 、0.1q max ，q max determining Reynolds number Re of each flow point under each caliber for the maximum flow of the vortex shedding flowmeter under the steam medium Steam generating device (i) I is the total number of flow points; wherein i belongs to N, and N is a natural number;
4) In order to realize the calibration of the vortex shedding flowmeter under the water medium and the air medium, the Reynolds number Re is determined according to the Reynolds number Re of each flow point based on the Reynolds number similarity principle Standard of merit (i) Determining Reynolds number R of each flow point in aqueous mediume Water (I) (i) And Reynolds number Re for each flow point in air medium Air (W) (i)，iIs the total number of flow points; reynolds number Re for each flow point Water (W) (i) And Reynolds number Re for each flow point Air (a) (i) The Reynolds number of the lowest flow velocity and the Reynolds number of the highest flow velocity under the corresponding medium and the corresponding caliber are not exceeded; i.e. Reynolds number Re per flow point in aqueous medium Water (I) (i) The Reynolds number of the lowest flow velocity under the corresponding caliber is not lower than the Reynolds number of the highest flow velocity under the corresponding caliber; reynolds number Re at each flow point in air medium Air (W) (i) The Reynolds number of the lowest flow velocity under the corresponding caliber is not lower than the Reynolds number of the highest flow velocity under the corresponding caliber;
specifically, based on the Reynolds number similarity principle, the Reynolds number Re under the aqueous medium is respectively determined according to 8 flow points corresponding to two DN (50), two DN (100), two DN (150) and two DN (200) Water (I) (i) And Reynolds number Re under air medium Air (W) (i) (ii) a Reynolds number Re at the determined aqueous medium in total Water (W) (i) 64, determined total reynolds numbers Re under air medium Air (a) (i) 64 are provided;
5) According to the caliber of the vortex shedding flowmeter and the Reynolds number Re of each flow point Water (W) (i) Determining the mass flow q of each flow point in an aqueous medium set-water (i) The Reynolds number Re of each flow point according to the caliber of the vortex shedding flowmeter Air (W) (i) Determining the mass flow q per flow point under an air medium set-air (i)；
Specifically, the Reynolds number Re of each flow point is determined according to the calibers DN (50), DN (100), DN (150) and DN (200) of the vortex shedding flowmeter Water (W) (i) Determining the mass flow q of each flow point in an aqueous medium set-water (i) That is, the mass flow q of 64 flow points can be determined set-water (i) (ii) a According to the caliber DN (50), DN (100), DN (150) and DN (200) of the vortex shedding flowmeter and the Reynolds number Re of each flow point Air (a) (i) Determining the mass flow q per flow point under an air medium set-air (i) Namely, 64 flow points can be determined;
6) According to the verification regulation of vortex shedding flowmeter JJJG 1029-2007, selecting a corresponding standard device, and respectively carrying out real flow detection on air and water media at corresponding flow points on the vortex shedding flowmeter with the selected DN (b) caliber;
according to q set-water (i) Measuring the gauge pressure p corresponding to each flow point under the aqueous medium 1 Water （i,j) The unit: kPa, gauge back pressure p 2 water （i,j) The unit: kPa, standard cumulative volume V Water (W) （i,j) The unit: l, and an accumulation pulse N Water (I) （i,j) The unit is: a plurality of; wherein the gauge front pressure p 1 Water （i,j) Gauge back pressure p 2 water （i,j) Standard cumulative volume V Water (W) （i,j) And accumulating pulses N Water (I) （i, j) The measurement is carried out for multiple times, specifically, the measurement times are more than or equal to 3, and preferably, the measurement times selected in the embodiment are 3; the working temperature of the medium is measured by a thermometer, the density of the medium is measured by a densimeter, the pressure in front of the meter and the pressure behind the meter are measured by a pressure meter, and the standard accumulated volume, the accumulated pulse and the actual instantaneous flow are measured by a vortex shedding flowmeter;
according to q set-air (i) Measuring the corresponding gauge pressure p of each flow point under the air medium 1 air of （i,j) The unit: kPa, gauge back pressure p 2 air (air) （i,j) The unit: kPa, standard cumulative volume V Air (W) （i,j) The unit is: l, and an accumulation pulse N Air (a) （i, j) The unit is: a plurality of; wherein the gauge front pressure p 1 air of （i,j) Gauge back pressure p 2 air (air) （i,j) Standard cumulative volume V Air (a) （i,j) And accumulating pulse N Air (a) （i,j) All measurements are carried out for a plurality of times; specifically, the number of times of measurement is greater than or equal to 3, and preferably, the number of times of measurement selected in this embodiment is 3; the working temperature of the medium being measured by a thermometerThe mass density is measured by a densimeter, the pressure before and after the meter is measured by a pressure meter, and the standard accumulated volume, the accumulated pulse and the actual instantaneous flow are measured by a vortex shedding flowmeter;
where i is the total number of flow points, j is the number of measurements per flow point, and in this embodimenti=64，j=3；
7) Calculating the average gauge pressure p corresponding to each flow point in the aqueous medium 1 Water (i) Average post gauge pressure p corresponding to each flow point 2 water (i)；
Calculating the average gauge pressure p corresponding to each flow point under the air medium 1 air of (i) Average post gauge pressure p corresponding to each flow point 2 air (air) (i)；
8) Respectively calculating the instrument coefficients K under the water medium and the air medium Water (W) （i,j) And K Air (W) （i,j) The calculation formula is as follows:
K air (W) （i,j）=N Air (a) （i,j）/V Air (a) （i,j）*1000
K Water (W) （i,j）=N Water (W) （i,j）/V Water (W) （i,j）*1000
According to K Air (a) （i,j) And K Water (I) （i,j) Respectively calculating the average meter coefficient K under the water medium Water (W) (i) And average gauge coefficient under air medium K Air (a) (i)；
Namely, it is
，
；
9) Establishing a correction factor mathematical model of instrument coefficients under a water-air medium:
K air (W) (i)= K Water (W) (i)/ε
Wherein,
a, b and c are fitting constants for the correction factors,
the vortex shedding flowmeter with each caliber corresponds to a geometric parameter variable which is dimensionless;
is an air isentropic adiabatic index which is dimensionless; p is a radical of formula 1 Equal to the mean pre-gauge pressure p in the air medium 1 air of (i)，p 2 Equal to the mean post-gauge pressure p under air medium 2 air (air) (i)；
And correcting the flow meter coefficient under the water-air medium according to the correction factor mathematical model.
Wherein, the calculation mode of the fitting constants a, b and c in the step 9) is as follows:
setting up
，
Can obtain the product
Under the conditions of determining the caliber DN (b) and determining the flow point, the method can be rewritten as follows:
calculating different apertures and different flow points
Value, will be at different apertures, different flow points
Fitting the values to obtain the values of a, b and c.
Specifically, the values of a, b, and c are obtained by MATLAB fitting calculation, or may be determined by other similar fitting calculation software, even manual calculation, and the like, and preferably, the values of a, b, and c in this embodiment are obtained by MATLAB fitting calculation, and according to the present embodiment, the diameters and the flow points of the embodiments
Value fit calculated a = -0.025, b = -0.0841, c = -0.0746;
so that a correction factor can be determined
Correction formula of instrument coefficient
In order to verify the reliability of the method of the invention, the following two methods are adopted for proving:
error method:
the corrected instrument coefficient under the water-air medium can be determined by the correction factor formula and the instrument coefficient correction formula
And average gauge factor K in air medium Air (a) (i) The error can be calculated according to the error formulaE：
TABLE 2 air Medium correction of Instrument coefficient fitting error
See table 2 for maximum fit error E = -0.64%, much less than its meter maximum allowed error 1.5% (precision 1.5). The correction method of the application is accurate and reliable.
Uncertainty method:
and carrying out uncertainty analysis on the fitting instrument coefficient to obtain:
wherein,
fitting the instrument coefficient K to the air medium Air (a) Uncertainty of (d)%;
referring to table 3, using a DN50 orifice flow meter as an example, one can obtain:
TABLE 3 uncertainty component of air medium instrument fitting coefficient
Uncertainty introduced to fitting formula of fitting instrument coefficientsu r （F) Taking DN50 as an example:
comprehensively considering, the uncertainty of the synthetic standard can be obtainedu r And uncertainty of expansionU r ：
In the same way, the uncertainty introduced by all the test caliber flowmeters in the coefficient fitting process and result of the air medium meter can be obtained:
TABLE 4 uncertainty introduced by correction of flow meter coefficient under air medium
Referring to table 4, from the uncertainty evaluation result, the uncertainty introduced by the fitting process and the result of the coefficient of the air medium instrument is small enough and is less than 1.5% of the maximum allowable error of the instrument, and the accuracy and reliability of the correction method can be proved.
Example 2
The flowmeter of the present embodiment is obtained by correcting the coefficient of the flowmeter under the water-air medium according to the method for correcting the coefficient of the flowmeter of embodiment 1.
Claims (8)
1. The method for correcting the coefficient of the flowmeter under the water-air medium is characterized by comprising the following steps of:
1) Selecting vortex shedding flowmeters with various calibers;
2) Calculating a geometric parameter variable beta corresponding to the vortex shedding flowmeter with each caliber;
3) Under a standard medium, a plurality of flow points are selected by the vortex shedding flowmeter with each caliber, and the Reynolds number Re of each flow point is determined Standard of reference (i)，iIs the total number of flow points;
4) Based on the Reynolds number similarity principle, the Reynolds number Re of each flow point Standard of merit (i) Determining Reynolds number Re at each flow point in aqueous medium Water (I) (i) And Reynolds number Re for each flow point in air medium Air (a) (i)；
5) According to the caliber of the vortex shedding flowmeter and the Reynolds number Re of each flow point Water (W) (i) Determining the mass flow q of each flow point in an aqueous medium set-water (i) According to the diameter of the vortex shedding flowmeter and the Reynolds number Re of each flow point Air (a) (i) Determine each under an air mediumMass flow q of individual flow points set-air (i)；
6) According to said q set-water (i) Measuring the gauge pressure p corresponding to each flow point under the aqueous medium 1 Water （i,j) The unit: kPa, gauge back pressure p 2 water （i,j) The unit: kPa, standard cumulative volume V Water (I) （i,j) The unit: l, and an accumulation pulse N Water (W) （i,j) The unit: a plurality of; wherein the gauge front pressure p 1 Water （i,j) Gauge back pressure p 2 water （i,j) Standard cumulative volume V Water (I) （i,j) And accumulating pulse N Water (W) （i,j) Measuring for multiple times;
according to said q set-air (i) Measuring the gauge pressure p corresponding to each flow point under the air medium 1 air of （i,j) The unit: kPa, gauge back pressure p 2 air (air) （i,j) The unit: kPa, standard cumulative volume V Air (a) （i,j) The unit: l, and an accumulation pulse N Air (a) （i, j) The unit: a plurality of; wherein the gauge front pressure p 1 air of （i,j) Gauge back pressure p 2 air (air) （i,j) Standard cumulative volume V Air (a) （i,j) And accumulating pulse N Air (a) （i,j) Measuring for multiple times;
wherein i is the total number of flow points, and j is the number of times each flow point is measured;
7) Calculating the average gauge pressure p corresponding to each flow point in the aqueous medium 1 Water (i) Average post gauge pressure p corresponding to each flow point 2 water (i)；
Calculating the average gauge pressure p corresponding to each flow point under the air medium 1 air of (i) Average post gauge pressure p corresponding to each flow point 2 air of (i)；
8) Respectively calculating instrument coefficients K under water medium and air medium Water (W) （i,j) And K Air (W) （i,j) The calculation formula is as follows:
K air (a) （i,j）=N Air (a) （i,j）/V Air (a) （i,j）*1000
K Water (W) （i,j）=N Water (I) （i,j）/V Water (W) （i,j）*1000
According to said K Air (W) （i,j) And said K Water (W) （i,j) Respectively calculating the average meter coefficient K under the water medium Water (W) (i) And average gauge coefficient under air medium K Air (W) (i)；
9) Establishing a correction factor mathematical model of instrument coefficients under a water-air medium:
K air (W) (i)= K Water (I) (i)/ε
Wherein,
for the correction factors, a, b and c are fitting constants,
the vortex shedding flowmeter with each caliber corresponds to a geometric parameter variable which is dimensionless;
is an air isentropic adiabatic index which is dimensionless; p is a radical of 1 Equal to the mean pre-gauge pressure p under an air medium 1 air of (i)，p 2 Equal to the mean gauge-rear pressure p in air medium 2 air of (i)；
And correcting the flow meter coefficient under the water-air medium according to the correction factor mathematical model.
2. The method for correcting the coefficients of the flowmeter under the water-air medium of claim 1, wherein the fitting constants a, b and c in the step 9) are calculated by:
setting up
，
To obtain
Calculating under different calibers and different flow points
Value, will be under different calibers, different flow points
Fitting calculation is carried out on the values to obtain the values of a, b and c.
3. The method for correcting the meter coefficient of the water-air medium lower flow meter according to claim 1, wherein in the step 2), the calculation formula of the geometric parameter variable β corresponding to the vortex shedding meter with each caliber is as follows:
wherein d (b) is the characteristic width of the generator, unit: mm; d (b) is the inner diameter of the vortex shedding flowmeter, and the unit is as follows: mm, b is the caliber of the vortex shedding flowmeter, unit: mm.
4. The method for correcting the meter coefficient of the flowmeter under the water-air medium as claimed in claim 1, wherein in the step 1), at least 3 kinds of calibers of the vortex shedding flowmeter are selected.
5. The method for correcting the meter coefficient of the water-air medium lower flow meter according to claim 1, wherein in the step 3), the number of the flow points of each caliber of the vortex shedding meter is more than or equal to 4.
6. The method for correcting the meter coefficient of a flow meter under a water-air medium according to claim 1, wherein in the step 4), the Reynolds number Re of each flow point Water (W) (i) The Reynolds number of the flow velocity is not lower than the Reynolds number of the lowest flow velocity under the corresponding caliber and is not higher than the Reynolds number of the highest flow velocity under the corresponding caliber; reynolds number Re for each flow point Air (a) (i) The Reynolds number of the lowest flow velocity under the corresponding caliber is not lower than the Reynolds number of the highest flow velocity under the corresponding caliber.
7. The method for correcting the meter coefficient of a water-air medium lower flow meter according to claim 1, wherein in the step 3), the standard medium is a steam medium.
8. A flowmeter, characterized in that it is corrected by the method for correcting the meter coefficient of a flowmeter under a water-air medium according to any one of claims 1 to 7.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH226256A (en) * | 1940-02-29 | 1943-03-31 | Gehre Hans Ing Dipl | Quantity measuring device for flowing media. |
| JPS57100311A (en) * | 1980-12-15 | 1982-06-22 | Oval Eng Co Ltd | Method for correcting instrument error of vortex flowmeter |
| CN1251652A (en) * | 1997-03-27 | 2000-04-26 | 罗斯蒙德公司 | Vortex flowmeter with signal processor |
| CN101720420A (en) * | 2007-06-30 | 2010-06-02 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
| CN105043511A (en) * | 2015-07-24 | 2015-11-11 | 合肥科迈捷智能传感技术有限公司 | Coefficient modification method of vortex shedding flowmeter based on Reynolds numbers |
| CN109945936A (en) * | 2019-03-25 | 2019-06-28 | 中国电力工程顾问集团西北电力设计院有限公司 | A kind of water and steam flow calculating method based on throttling set measurement |
-
2022
- 2022-10-19 CN CN202211280951.XA patent/CN115342889B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH226256A (en) * | 1940-02-29 | 1943-03-31 | Gehre Hans Ing Dipl | Quantity measuring device for flowing media. |
| JPS57100311A (en) * | 1980-12-15 | 1982-06-22 | Oval Eng Co Ltd | Method for correcting instrument error of vortex flowmeter |
| CN1251652A (en) * | 1997-03-27 | 2000-04-26 | 罗斯蒙德公司 | Vortex flowmeter with signal processor |
| CN101720420A (en) * | 2007-06-30 | 2010-06-02 | 恩德斯+豪斯流量技术股份有限公司 | Measuring system for a medium flowing in a process line |
| CN105043511A (en) * | 2015-07-24 | 2015-11-11 | 合肥科迈捷智能传感技术有限公司 | Coefficient modification method of vortex shedding flowmeter based on Reynolds numbers |
| CN109945936A (en) * | 2019-03-25 | 2019-06-28 | 中国电力工程顾问集团西北电力设计院有限公司 | A kind of water and steam flow calculating method based on throttling set measurement |
Non-Patent Citations (3)
| Title |
|---|
| KYUNG-WON LEE: "Interfacial condensation for countercurrent steam–water stratified wavy flow in a horizontal circular pipe", 《INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER》 * |
| SAMANZARE: "Experimental study of direct contact condensation of steam jet in water flow in a vertical pipe with square cross section", 《MULTIPHASE FLOW》 * |
| 康勇: "涡轮流量计测量结果的不确定度分析", 《仪器仪表标准化与计量》 * |
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