Precession vortex flowmeter in root cause analysis (errors in measuring gas medium of On)
by:Kaidi Sensors
2020-09-17
Precession vortex flowmeter, as a kind of measuring instrumentation of gas medium, because of its no mechanical moving parts, corrosion resistance, stable and reliable, long life, long running without special maintenance;
Implements the mechanical and electrical integration, daily measurement process does not need artificial unattended;
Installation conditions is not strict, straight pipe upstream or downstream instrument can greatly shorten the orifice plate and the vortex street flowmeter;
System of measurement accuracy can meet the requirements of the current measurement of trade (
≤
1.
5%)
;
The flow measurement range is wide,
qmax / qmin = 15 ~ 20)
, can be in orifice and vortex flowmeter can not involved in parts of the small flow area to work effectively;
Small volume, light weight, offline calibration more convenient;
Measuring signals as well as local display, also can be on-demand remote transmission and so on a series of advantages, Dali used in industrial production, but for each instrument measurement is impossible to achieve perfect, vortex precession flowmeter is not exceptional also, embellish of instrument science and technology in the process of the feedback information from the user's Dali summed up a set of for how to optimize and improve the vortex precession flowmeter measurement precision and stability of the solution.
In order to help friends to solve in the process of using vortex precession flowmeter doubts and difficulties, specially writing will experience to share with you, this technology is divided into two articles.
One, the principle and process of vortex precession flowmeter precession vortex flow meter belongs to the velocity instrument, when along the axial flow of the fluid at the entrance into the flow sensor, vortex force fluid body blade rotation, then produce spiral flow in the center of the vortex in body.
Vortex flow precession in the venturi tube, reached the contraction section of throttling the vortex flow speed up suddenly, after the vortex flow into the diffuser, due to the effect of reflow forced spiral precession.
The rotation of the vortex flow frequency and is directly proportional to the velocity of the fluid.
Piezoelectric sensors to detect the weak signal processing by preamplifier can get we need traffic signals.
Second, the main reason of measurement deviation caused by 1.
Performance measurement instrument itself (
1)
The length of the straight section of straight pipe standard qualified affect performance measurement instrument itself, because the measuring results is limited by the fluid flow state, so in the before and after parts of the meter, straight pipe should be long enough to cut the qualified, to ensure the steady flow of medium.
Generally, straight pipe not less than 5 d before table, the table after the straight pipe not less than 1 d.
(
2)
Flow range due to the different specifications, so the flowmeter flow range is different also, at the same time, the flowmeter can't detect below the lower limit of flow, it is hard to ensure its accuracy;
At the same time, when the gas is on the high side, more than standard, will cause the loss of pressure, the pulse missing, missing measurement, etc. , in this case, to ensure its accuracy, it is even harder.
(
3)
Accurate detection for the accurate measurement of the gas pressure pressure plays a decisive role, first, the pressure is inversely proportional to the relative error, the higher the pressure, the relative error is smaller and smaller, therefore, in the selection flow timing, to fully consider the condition of high pressure, in order to select the appropriate sensor range.
2.
Various working conditions caused by measurement error (
1)
Mechanical vibration of pipeline strong mechanical vibration, the influence of vortex precession flowmeter metering accuracy is reduced.
(
2)
Impurity gas flowmeter sensor of temperament is very demanding, containing impurities or impurity gas blocking flowmeter in flow, influence the flow meter of eddy current sensor rotation frequency measurement.
Therefore, the separation of gases or filtering effect should be good.
According to the same period volume ratio, dust inside the vortex precession flowmeter is more than the absence of dust reduce about 3% of the volume.
Domestic gas gas transmission pipeline network line due to the construction for a long time, MAO pipe internally produce ferrous sulfide particles, the decline in efficiency sensors;
At the same time, the various original equipment and various connection parts of flowmeter on temperament is very high, the liquid is contained in natural gas, corrosion flowmeter sensors and various connection parts, sealing gasket commonly used in the connection part, the droplets in the electrolyte solution and corrosion parts forming gaskets, gasket of flowmeter even after corrosion forms of local micro leakage may also affect period accurate measurement.
(
3)
Electromagnetic interference manufacturers in developing this kind of flow time, fully consider the power meter under sustainable work, therefore, in the vortex precession flowmeter totalizer. especially electrically erasable programmable read-only memory (
EEPROM)
Have stored manufacturer of setting parameters and calibration set.
But these parameters in case of other strong interference (
The high tension line lightning, overhead)
, some parameter changes.
Instrument display appears in some random measurement results, to paralyze the instrument.
3.
Other reasons for instrument maintenance department in place;
Related parameters drift;
By-pass leakage;
Violation of operating procedures;
No school on schedule;
Damage to equipment and so forth also causes measurement error.
In the process of production, all kinds of phenomena occur, for example, flow instability, selection of range is too small, medium flow frequent fluctuation, etc, will cause measurement error.
A sudden change in the velocity and pressure, the medium into a pulsating flow, differential pressure becomes large or small and appear obvious pulsing flow, measuring may cause greater error.
In this paper by embellish instrument technology co. , LTD. Arrange release.
Guangdong Kaidi Energy Technology Co., Ltd. has various branches in different countries worldwide.
We are proud to be one of the largest suppliers out there. You will love what we offer for your level gauge solution. Check our website at Kaidi level indicator or call to talk to our customer service department with any questions you may have.
customized level indicator level gauge are primarily used for customized level indicator.
Guangdong Kaidi Energy Technology Co., Ltd. have been an established and popular company with an excellent track record for the best customer satisfaction.
Guangdong Kaidi Energy Technology Co., Ltd. has various branches in different countries worldwide.
We are proud to be one of the largest suppliers out there. You will love what we offer for your level gauge solution. Check our website at Kaidi level indicator or call to talk to our customer service department with any questions you may have.
customized level indicator level gauge are primarily used for customized level indicator.
Guangdong Kaidi Energy Technology Co., Ltd. have been an established and popular company with an excellent track record for the best customer satisfaction.
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