CN104981684A - Method and apparatus for monitoring measurement state of coriolis mass flowmeter - Google Patents
Method and apparatus for monitoring measurement state of coriolis mass flowmeter Download PDFInfo
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Classifications
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/76—Devices for measuring mass flow of a fluid or a fluent solid material
- G01F1/78—Direct mass flowmeters
- G01F1/80—Direct mass flowmeters operating by measuring pressure, force, momentum, or frequency of a fluid flow to which a rotational movement has been imparted
- G01F1/84—Coriolis or gyroscopic mass flowmeters
- G01F1/8409—Coriolis or gyroscopic mass flowmeters constructional details
- G01F1/8436—Coriolis or gyroscopic mass flowmeters constructional details signal processing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/10—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of flowmeters
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Abstract
A method and apparatus for monitoring a measurement state of a Coriolis mass flowmeter. An equivalent driving force F is applied to replace a Coriolis force Fc generated when a liquid passes through a vibration pipeline, it is ensured that an acting effect of the equivalent driving force F is the same as an acting effect of the Coriolis force Fc, a phase difference is generated at two sides of the sensor vibration pipeline without circulating the liquid, and a flow transmitter displays, by means of continuous detection and calculation, a mass flow value when the liquid is circulated. By changing the value of the equivalent driving force F, and comparing a flow value qm' displayed by the transmitter and an assumed flow value qm to obtain a difference, the working state of the flowmeter can be monitored without circulating the liquid. The apparatus comprises an apparatus for applying the equivalent driving force F, the acting effect of the equivalent driving force F is the same as the acting effect of the Coriolis force Fc, and the applying position and the value of the equivalent driving force F satisfy a torque condition 2F.d=T.
Description
Technical field
The present invention relates to the monitoring field of flow instrument, be specifically related to a kind of measuring state monitoring method and device of coriolis mass flowmeters.
Background technology
Coriolis mass flowmeters (hereinafter referred to as mass flowmeter) is a kind of instrument directly can measuring liquid mass flow, is widely used at present in the every field of national product.In order to accuracy and the reliability of flowmeter survey data of ensuring the quality of products, general way is periodically calibrated, in " People's Republic of China's measurement verification article ", the calibration interval of definite quality flowmeter are 0.5 year/time-2 years/time, whether the actual measurement state of instrument in the engineer applied of reality of assay approval can ensure, the calibrating term of validity is by the time only had to terminate, get back to calibrating installation could accurately judge, also cannot accurately judge online by rapid field at present.
For the flowmeter in coming into operation, field working conditions is complicated, the factor affecting flow measurement accuracy of measurement is a lot, as the installation of flowmeter, the fault of flow sensor, extraneous complex environment (shock and vibration) impact, all can the measurement of flow meter impact.In the calibration cycle of flowmeter, the measuring state of flowmeter is difficult to judge.Current general determination methods is that flowmeter is separated pipeline, manually demarcates in the lab, judges whether flowmeter is in abnormal operation.This mode is ripe, accurate, but expends more human and material resources and financial resource, adds the down time of equipment, has a strong impact on production efficiency.According to statistics, the every platform deutero-albumose of mass flowmeter that China comes into operation every year determines testing cost at 2000 to 3000 yuan of thousand Renminbi.And the measuring state of the monitoring method energy flow meter that the present invention proposes carries out effective on-line monitoring, observation process flowmeter is without the need to separating pipeline, and observation process is convenient and swift.At present in disclosed patent, Micro Motion, Inc of U.S. publication number is in the patent of CN 1860350A and CN 101622519A, propose the inline diagnosis method and system of vibrating conduit, the Main Basis of diagnosis is the change of vibrating conduit rigidity in flow meters work process, wherein all lacks the consideration on the impact of fluid in flow vibrating conduit.
Summary of the invention
The object of the invention is: the measuring state monitoring method and the device that propose a kind of brand-new coriolis mass flowmeters, and what solve that conventional offline monitoring brings loses time and the technical matters of waste of manpower, material resources and financial resources.
Technical solution of the present invention is:
A measuring state monitoring method for coriolis mass flowmeters, its special character is: comprise the following steps:
1] select and record 5-10 the flow value q be dispersed in coriolis mass flowmeters range
m;
According to the flow value q selected
m, determine that the measurement liquid of each flow value is to the active position of the equivalent driving force F of the coriolis force Fc that coriolis mass flowmeters vibrating tube produces and action direction respectively, calculate and record the size of equivalent driving force F; The action effect of equivalence driving force F is identical with the action effect of coriolis force Fc;
2] close the valve of on-the-spot coriolis mass flowmeters both sides, guarantee to be full of in the vibrating tube of on-the-spot coriolis mass flowmeters to measure liquid and measure liquid being in complete stationary state, start transmitter;
3] in the vibrating tube of coriolis mass flowmeters, apply step 1] in equivalent driving force F corresponding to one of them flow value of record N time altogether, 5>=N>=2, record the flow value q that Displaying Meter each time shows
m'; Obtain q
m' mean value
if
value be less than 1%, continue judge other flow values under,
value whether be less than 1%; If under each flow value,
value be all less than 1%, then the measuring state of coriolis mass flowmeters is normal, otherwise be exception.
Above-mentioned steps 3] in apply the concrete grammar of equivalent driving force F and be:
3.1] for the coriolis mass flowmeters of single-tube, according to step 1 in vibrating tube] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the correspondence position of the shell of coriolis mass flowmeters, make the first permanent magnet stretch into the first analog-driven coil inside, the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein in a vibrating tube according to step 1] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, another root vibrating tube is fixed with about symmetrical axisymmetric first permanent magnet of this vibrating tube and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside;
The output of flow transmitter provides the drive singal of normal work for coriolis mass flowmeters, and the output of flow transmitter also accesses the first analog-driven coil and the second analog-driven coil respectively successively after phase-shift circuit, amplitude control circuitry, power amplification circuit;
3.2] be energized, the number of turns of size of current I and coil and the size of equivalent driving force F meet relations I=F/NBL, and wherein, N is the number of turns of coil, and B is the magnetic field intensity of permanent magnet, and I is the size of current passed in coil, and L is the length of electrified wire.
Above-mentioned steps 3.1] in, phase-shift circuit comprises operational amplifier, feedback resistance R1, resistance R2, resistance Rx, electric capacity c, the positive input terminal of operational amplifier connects the output of flow transmitter by resistance Rx, the positive input terminal of operational amplifier is by electric capacity c ground connection, the negative input end of operational amplifier connects the output of flow transmitter by resistance R2, the negative input end of operational amplifier also connects the output terminal of operational amplifier by feedback resistance R1, operational amplifier exports the input connecing amplitude control circuitry.
Above-mentioned steps 3.1] in, power amplification circuit comprises triangular-wave generator, sinusoidal synthesizer, comparator circuit, Bridge output stage circuit and low-pass filter circuit, the output terminal of triangular-wave generator and sinusoidal synthesizer is connected to the input end of comparator circuit, the output terminal of comparator circuit is connected with low-pass filter circuit by Bridge output stage circuit, low-pass filter circuit exports and connects the first driving former-wound coil and the second driving former-wound coil respectively, and sinusoidal synthesizer connects the output of amplitude control circuitry.
Above-mentioned steps 3.1] in, amplitude control circuitry comprises the filtering circuit and potentiometer that are connected on phase-shift circuit output terminal successively, and the output of potentiometer is connected with the input of sinusoidal synthesizer.
A kind of measuring state monitoring device of coriolis mass flowmeters, its special character is: the bringing device comprising equivalent driving force F, the action effect of equivalence driving force F is identical with the action effect of coriolis force Fc, applying position and the size of equivalence driving force F meet moment condition 2Fd=T, wherein d is the distance of application point to the axis of symmetry of vibrating tube of equivalent driving force, and T is the Coriolis moment of couple.
The bringing device of above-mentioned equivalent driving force F comprises the first analog-driven coil, the second analog-driven coil, the first permanent magnet, the second permanent magnet, phase-shift circuit, amplitude control circuitry and power amplification circuit; For the coriolis mass flowmeters of single-tube, vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the relative position of coriolis mass flowmeters shell, make the first permanent magnet stretch into the first analog-driven coil inside, the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein a vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, the relative position of another root vibrating tube is fixed with the first permanent magnet and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; One tunnel of flow transmitter exports the drive singal that the drive coil being connected to vibration transducer provides normal work, another road of flow transmitter is exported and is connected with the first analog-driven coil and the second analog-driven coil respectively by phase-shift circuit, amplitude control circuitry, power amplification circuit successively, and the input signal access direction of the first analog-driven coil and the second analog-driven coil is contrary.
Above-mentioned phase-shift circuit comprises operational amplifier, feedback resistance R1, resistance R2, resistance Rx, electric capacity c, the positive input terminal of operational amplifier connects the output of flow transmitter by resistance Rx, the positive input terminal of operational amplifier is by electric capacity c ground connection, the negative input end of operational amplifier connects the output of flow transmitter by resistance R2, the negative input end of operational amplifier also connects the output terminal of operational amplifier by feedback resistance R1, operational amplifier exports the input connecing amplitude control circuitry.
Above-mentioned power amplification circuit comprises triangular-wave generator, sinusoidal synthesizer, comparator circuit, Bridge output stage circuit and low-pass filter circuit, the output terminal of triangular-wave generator and sinusoidal synthesizer is connected to the input end of comparator circuit, the output terminal of comparator circuit is connected with low-pass filter circuit by Bridge output stage circuit, low-pass filter circuit exports and connects the first driving former-wound coil and the second driving former-wound coil respectively, and sinusoidal synthesizer connects the output of amplitude control circuitry.
Above-mentioned amplitude control circuitry comprises the filtering circuit and potentiometer that are connected on phase-shift circuit output terminal successively, and the output of potentiometer is connected with the input of sinusoidal synthesizer.
Advantage of the present invention is: method of the present invention and device can be well the periodic detection maintenance service of mass flowmeter, the measuring state of energy flow meter carries out effective on-line monitoring, improve the on-line monitoring efficiency of mass flowmeter, operator can judge whether flowmeter is in abnormal operation at the scene fast, observation process is convenient and swift, the problems such as unreliable, the mount stress impact avoiding unnecessary disassembly cost and off-line refitting to produce, reduce monitoring cost, save human and material resources resource, have great engineering significance in actual applications.
Accompanying drawing explanation
Fig. 1 is the double-C shaped coriolis mass flowmeters sensor schematic diagram that the present invention improves;
Wherein 101 and 201 two vibrating tube being respectively flowmeter; 102 and 202 are respectively the first permanent magnet and the first analog-driven coil; 104 and 204 are respectively the second analog-driven coil and the second permanent magnet; 103 and 203 is left magnetic test coil and left permanent magnet, and 105 and 205 is right permanent magnet and right magnetic test coil; 106 and 206 is the drive coil of vibrating tube and driving permanent magnet.
Fig. 2 a is quality flowmeter flow quantity tube vibrorecord;
Fig. 2 b is quality flowmeter flow quantity tube deflection deformation figure;
Fig. 3 a is double-C shaped mass flowmeter liquid flow schematic diagram;
Fig. 3 b is double-C shaped mass flowmeter vibration distribution of force schematic diagram;
Fig. 4 is monitoring device theory diagram in the present invention;
Fig. 5 is the transmission of each parameter in the mass flowmeter course of work;
Fig. 6 is the phase-shift circuit figure designed in the present invention;
Fig. 7 is the Basic Topological of the power amplification circuit in the present invention.
Embodiment
The ultimate principle of mass flow meter measurement is the Coriolis effect of liquid in vibrating tube.In typical mass flowmeter application, the drive coil 106 of the vibrating tube of self and driving permanent magnet 206 interact to vibrating tube and apply driving force, and vibrating tube is vibrated with certain frequency.Do not have liquid stream when vibrating tube, in vibrating tube, each point is with identical phase oscillation, as Fig. 2 a.When there being liquid to flow through vibrating tube, vibrating tube is subject to the effect of the coriolis force (Fc in Fig. 2 b) that liquid produces, and coriolis force makes vibrating tube each point produce different phase places, as Fig. 2 b.AC section is identical with the coriolis force size suffered by BD section, direction contrary (Fc direction as shown in figure 2b).Left magnetic test coil 103 and right magnetic test coil 205 are placed on drive coil 106 both sides about on axisymmetric two differences of symmetry, are used for the vibration signal of detection 2.The phase difference t of two signals received from this left magnetic test coil 103 and right magnetic test coil 205 is calculated in the unit interval.Between two magnetic test coils, the phase differential of signal is directly proportional to the mass rate of the liquid flowing through this vibrating tube.That is: q
m=K Δ t, K is the instrument coefficient of flowmeter, the fundamental formular of mass flow meter measurement mass rate that Here it is.The essence of flow measurement be liquid by producing coriolis force during pipeline, the contrary coriolis force in direction, pipeline both sides makes pipeline twist deformation.
Based on above analysis, by applying the coriolis force Fc that equivalent driving force F replaces liquid to be produced by pipeline, ensure that equivalent driving force F is identical with the action effect of coriolis force Fc, just can be implemented in when not circulating this liquid, produce phase differential in the both sides of sensor vibration pipe, flow transmitter is by continual detection and resolve the mass flow value demonstrated when circulating this liquid.If the size of additional equivalent driving force F and the liquid stream value q of hypothesis can be determined further
mbetween corresponding relation, by changing the size of equivalent driving force F, contrast transmitter display flow value q
m' with hypothesis flow q
mdifference, monitor with regard to the duty of flow meter when this liquid obstructed can be realized.The transmission of the observation process of coriolis mass flowmeters and each parameter can be illustrated by the flow process of Fig. 5.
Therefore, the present invention includes following steps:
1, a measuring state monitoring method for coriolis mass flowmeters, comprises the following steps:
1] select and record 5-10 the flow value q be dispersed in coriolis mass flowmeters range
m;
According to the flow value q selected
m, determine that the measurement liquid of each flow value is to the active position of the equivalent driving force F of the coriolis force Fc that coriolis mass flowmeters vibrating tube produces and action direction respectively, calculate and record the size of equivalent driving force F;
2] close the valve of on-the-spot coriolis mass flowmeters both sides, guarantee to be full of in the vibrating tube of on-the-spot coriolis mass flowmeters to measure liquid and measure liquid being in complete stationary state, start transmitter;
3] according to step 1] in record, the vibrating tube of coriolis mass flowmeters applies equivalent driving force F corresponding to certain flow value N time altogether, 5>=N>=2, records the flow value q that Displaying Meter each time shows
m'; Obtain q
m' mean value
if
value be less than 1%, continue judge other flow values under,
value whether be less than 1%, if under each flow value,
value be all less than 1%, then the measuring state of coriolis mass flowmeters is normal, otherwise be exception.
Above-mentioned steps 1] in, the determination of the active position of equivalent driving force F, action direction and size can be realized by following two kinds of methods: A. theory calculate; B. simulate in advance under line.
A. theory calculate
1.1] active position of equivalent driving force F and the determination of size
Count example with double-C shaped mass rate, stressed sketch during measurement fluid flow as shown in Figure 3 a.When liquid flow direction as shown in fig. 3a, when the driving force of E point is outside along paper, left, the liquid velocity V of the straight-tube portion of sensor is parallel with angular velocity omega for the direction level of angular velocity omega,
because θ=0, so straight length liquid can not produce coriolis force.Be subject to the effect of liquid coriolis force at bend loss pipeline, and bend loss θ angle is constantly change, so coriolis force is also constantly change.At C point place, angle theta=90 ° of angular velocity of rotation and liquid velocity V, coriolis force is maximum herein.C point upper and lower both sides coriolis force constantly reduces, and presenting with C is the symmetrical of symmetric points.Coriolis force according to bend loss distributes as shown in Figure 3 b, and the large small magnitude of the coriolis force along B to D is by sinusoidal rule distribution.
The angular velocity supposing vibrating tube actual vibration is ω, and in pipeline, liquid velocity is V, and liquid elementary mass is dm, then the size of coriolis force that liquid infinitesimal produces is:
dFc＝dm·a
k(1)
A
kfor the Coriolis acceleration of liquid infinitesimal, its expression formula is:
Wherein θ is the angle in flow rate of liquid direction in the direction of angular velocity omega and pipeline, as shown in Figure 3 a.
Within the dt time interval, the length of the vibrating tube that liquid flows through is the quality of dl, dl section liquid is dm, supposes that liquid velocity is constant, then
so formula (1) becomes:
The Coriolis moment of couple that in Fig. 3 a, the bend loss on the left side is subject to is:
In formula (4), L is the length of straight length, and R is the radius of bend loss.
On mass flowmeter, the selected application point that will apply equivalent driving force F, need meet moment condition 2Fd=T.Wherein d is the distance of application point to the axis of symmetry (dot-and-dash line in Fig. 3 a) of C shape pipe of equivalent driving force, and the dimensional parameters of needs can obtain with reference to shop instructions or direct measurement, thus determines the size of equivalent driving force F.Determine that the size of equivalent driving force F is the method that the present invention adopts by the integral and calculating coriolis force moment of couple, other methods coriolis force being converted into equivalent driving force also can adopt.
Therefore, at C point and F point, the size of equivalent driving force is
The size of equivalence driving force F and flow q
mrelation determined.
The driving force of simulation coriolis force applies position except C point and F point, also can have multiple, applying position can at the bend loss of corioliseffect, also can at the straight length of non-corioliseffect, concrete applying requirement should meet moment condition 2Fd=T, and the resultant couple square namely applying equivalent force will equal the moment of couple of coriolis force.
1.2] the action direction analysis of equivalent driving force F: when liquid flows in the vibrating tube being in vibrational state, vibrating tube is except being that ω does except principal oscillation with self-excited oscillatory frequency, due to the existence of coriolis force, the coriolis force size that same vibrating tube import and export both sides are subject to is identical, direction contrary, and vibrating tube produces the forced torque drive under same frequency.Under corioliseffect, now, vibrating tube is actual is among the principal oscillation of same frequency and the compound vibration of twisting vibration.Coriolis force to be simulated accurately, need the corioliseffect direction considering vibrating tube both sides contrary, and the frequency of action direction change be identical with the frequency that drive singal direction changes.The present invention adopts angular velocity of vibration to be the driving modulating signal source of principal oscillation drive singal as equivalent driving force of ω, and both sides equivalence driving force vibration phase is contrary.Other methods that can produce the equivalent driving force of cycle alternation also can use.
B. simulate in advance under line:
1.1] double-C shaped coriolis mass flowmeters is calibrated;
1.2] make in the vibrating tube of double-C shaped coriolis mass flowmeters, to be full of the set inactive liquid identical with on-the-spot liquid, start transmitter, the vibrating tube of coriolis mass flowmeters applies equal and opposite in direction, direction about axisymmetric two the equivalent driving force F of symmetry of vibrating tube respectively about the axisymmetric both sides of the symmetry of vibrating tube, adjusts two equivalent driving force F and make Displaying Meter display flow be q
m, record active position and the size of now equivalent driving force F.
Adjusting two equivalent driving force F makes Displaying Meter display flow be q
mmethod have two kinds:
The first: by fixing the size of two equivalent driving force F, the active position of adjustment two equivalent driving force F, making Displaying Meter show flow is q
m.
The second: by fixing the active position of two equivalent driving force F, it is q that the size of adjustment two equivalent driving force F makes Displaying Meter show flow
m, record one group of corresponding q
mwith equivalent driving force.Be convenient to realize in this methods engineering practice.
Above-mentioned steps 3] in the mode of equivalent driving force F that applies have multiple, include but not limited to the following method that the present invention adopts:
3.1] for the coriolis mass flowmeters of single-tube, according to step 1 in vibrating tube] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the shell of coriolis mass flowmeters, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein in a vibrating tube according to step 1] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, another root vibrating tube is fixed with about symmetrical axisymmetric first permanent magnet of this vibrating tube and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; Use the applying of the combination realizable force of permanent magnet and drive coil, principle is the effect that electrified wire is subject to power in magnetic field, i.e. the generation principle of Ampère force:
F
drive=NBIL (5)
Wherein, N is the number of turns of coil, and B is the magnetic field intensity of permanent magnet, and I is the size of current passed in coil, and L is the length of electrified wire;
The output of flow transmitter provides the drive singal of normal work for coriolis mass flowmeters, and the drive output signal of flow transmitter also accesses the first analog-driven coil and the second analog-driven coil respectively successively after phase-shift circuit, amplitude control circuitry, power amplification circuit;
3.2] be energized, the number of turns of size of current I and coil and the size of equivalent driving force F meet relations I=F/NBL, and wherein, N is the number of turns of coil, and B is the magnetic field intensity of permanent magnet, and I is the size of current passed in coil, and L is the length of electrified wire; The size of equivalent driving force F is changed by the turn number N that changes the first analog-driven coil and the second analog-driven coil and the size of current I that passes into.
The theory diagram of the monitoring device of coriolis mass flowmeters of the present invention as shown in Figure 4, comprises the bringing device of equivalent driving force F, and the action effect of equivalent driving force F is identical with the action effect of coriolis force Fc.The moment condition 2Fd=T that the applying position of equivalence driving force F and size demand fulfillment are analyzed above.
The bringing device of equivalence driving force F comprises the first analog-driven coil, the second analog-driven coil, the first permanent magnet, the second permanent magnet, phase-shift circuit, power amplification circuit and amplitude control circuitry; For the coriolis mass flowmeters of single-tube, vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the shell of coriolis mass flowmeters, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein a vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, another root vibrating tube is fixed with about symmetrical axisymmetric first permanent magnet of this vibrating tube and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; The drive coil that the driver output of flow transmitter is vibration transducer provides the normal drive singal worked, take out the output of this signal to be connected with the first analog-driven coil and the second analog-driven coil respectively by phase-shift circuit, amplitude control circuitry, power amplification circuit successively, the input signal access direction of the first analog-driven coil and the second analog-driven coil is contrary, to ensure that correct analog vibration pipe both sides are subject to the action character of contrary coriolis force.
The midpoint of the present invention's two bend loss in a wherein vibrating tube 101 of double-C shaped coriolis mass flowmeters is fixed with the first permanent magnet 102 and the second analog-driven coil 104 respectively, the midpoint of two bend loss of another root vibrating tube 201 fixes the first analog-driven coil 202 and the second permanent magnet 204, respectively as Fig. 1.First permanent magnet and the second permanent magnet are fixed by permanent magnet bracket; First analog-driven coil and the second analog-driven coil are fixed by coil brace, and permanent magnet bracket and coil brace are welded in respective vibrating tube, also can adopt other reliable fixed forms; Keep permanent magnet bracket and coil brace cross weld during welding, the mass balance of two vibrating conduits can be made like this.
For the coriolis mass flowmeters of single-tube, according to step 1 in vibrating tube] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the shell of coriolis mass flowmeters, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside.
When using device of the present invention to carry out the simulation of coriolis force, first be to the first analog-driven coil and the vibration frequency of the second analog-driven coil and the control of vibration phase, the frequency of the coriolis force that the equivalent driving force F that the first analog-driven coil and the second analog-driven coil are produced produces with actual liquid and phase-locking; And then the amplitude of equivalent driving force F is accurately controlled, control the electric current by the bringing device of equivalent driving force F further, realize equivalent force size and control, simulate the coriolis force of this liquid generation to the action effect of vibrating conduit with regard to can completely.
Therefore, the input signal of the first analog-driven coil and the second analog-driven coil drive signal is directly introduced by the drive singal of vibrating tube, ensure that consistent in vibration frequency of the signal of the drive singal of vibrating tube and the bringing device of equivalent driving force F.
There is the deviation in phase place in the drive singal of flow transmitter and coriolis force, device of the present invention carrys out travel(l)ing phase by phase-shift circuit, as shown in Figure 6.The effect of phase-shift circuit is the skew making drive singal produce stationary phase, to meet the phase relation of vibrating tube drive singal and coriolis force.Phase-shift circuit in the present invention comprises operational amplifier, feedback resistance R1, resistance R2, resistance Rx, electric capacity c, the positive input terminal of operational amplifier connects the output of flow transmitter by resistance Rx, the positive input terminal of operational amplifier is by electric capacity c ground connection, the negative input end of operational amplifier connects the output of flow transmitter by resistance R2, the negative input end of operational amplifier also connects the output terminal of operational amplifier by feedback resistance R1, operational amplifier exports the voltage signal of phase shift to amplitude control circuitry.Other phase-shift circuits met the demands also can adopt.
Amplitude control circuitry comprises the filtering circuit and potentiometer that are connected on phase-shift circuit output terminal successively, and the output of potentiometer is connected with the input of sinusoidal synthesizer.Amplitude control circuit drives the size of electric current in former-wound coil for controlling the first driving former-wound coil and second.
Power amplification circuit comprises triangular-wave generator, sinusoidal synthesizer, comparator circuit, Bridge output stage circuit and low-pass filter circuit, the output terminal of triangular-wave generator and sinusoidal synthesizer is connected to the input end of comparator circuit, the output terminal of comparator circuit is connected with low-pass filter circuit by Bridge output stage circuit, low-pass filter circuit exports and connects the first driving former-wound coil and the second driving former-wound coil respectively, and the sinusoidal synthesizer of power amplification circuit connects the output of amplitude control circuitry.The effect of power amplification circuit improves drive system to the driving force of vibrating tube, and its Basic Topological such as Fig. 7 shows.
Below monitoring precision of the present invention is verified:
1. theoretical calculation
Get a normal double-C shaped coriolis mass flowmeters, apply equivalent driving force F in the mid point section of bend loss,
vibrating tube actual parameter: ω=1.78rad/s, R=0.0955m, L=0.23m,
so F=0.6128q
m(q
munit be kg/s), following table q
munit be kg/h.First drives the former-wound coil number of turn and first to drive the former-wound coil number of turn to be 159 circles, resistance 11.2 Ω, winding diameter φ=9.6mm, permanent magnet magnetic field strength 3200Gs.
The monitor and feedback of test findings, all in 1% scope, illustrates and uses this monitoring device to judge that this type coriolis mass flowmeters is in normal duty.The method and device can realize the on-line monitoring of coriolis mass flowmeters duty.
2. line Imitating method
Select a normal double-C shaped coriolis mass flowmeters, choosing vibrating tube both sides bend loss point midway and fix first, second analog-driven coil, by changing the size of equivalent driving force F, simulating the mass rate q of different size
m.Data and the actual displayed mass rate of simulation are as follows:
Show that the monitor and feedback of test findings is all in 1% scope by upper table, illustrate and use the coriolis mass flowmeters of monitoring device of the present invention monitoring to be in normal operating conditions.So this monitoring method and monitoring device may be used for the on-line monitoring of coriolis mass flowmeters duty.
Claims (10)
1. a measuring state monitoring method for coriolis mass flowmeters, is characterized in that: comprise the following steps:
1] select and record 5-10 the flow value q be dispersed in coriolis mass flowmeters range
m;
According to the flow value q selected
m, determine that the measurement liquid of each flow value is to the active position of the equivalent driving force F of the coriolis force Fc that coriolis mass flowmeters vibrating tube produces and action direction respectively, calculate and record the size of equivalent driving force F; The action effect of equivalence driving force F is identical with the action effect of coriolis force Fc;
2] close the valve of on-the-spot coriolis mass flowmeters both sides, guarantee to be full of in the vibrating tube of on-the-spot coriolis mass flowmeters to measure liquid and measure liquid being in complete stationary state, start transmitter;
3] in the vibrating tube of coriolis mass flowmeters, apply step 1] in equivalent driving force F corresponding to one of them flow value of record N time altogether, 5>=N>=2, record the flow value q that Displaying Meter each time shows
m'; Obtain q
m' mean value
if
value be less than 1%, continue judge other flow values under,
value whether be less than 1%; If under each flow value,
value be all less than 1%, then the measuring state of coriolis mass flowmeters is normal, otherwise be exception.
2. the measuring state monitoring method of a kind of coriolis mass flowmeters according to claim 1, is characterized in that: step 3] in apply the concrete grammar of equivalent driving force F and be:
3.1] for the coriolis mass flowmeters of single-tube, according to step 1 in vibrating tube] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the correspondence position of the shell of coriolis mass flowmeters, make the first permanent magnet stretch into the first analog-driven coil inside, the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein in a vibrating tube according to step 1] the equivalent driving force F that determines applies position and is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, another root vibrating tube is fixed with about symmetrical axisymmetric first permanent magnet of this vibrating tube and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside;
The output of flow transmitter provides the drive singal of normal work for coriolis mass flowmeters, and the output of flow transmitter also accesses the first analog-driven coil and the second analog-driven coil respectively successively after phase-shift circuit, amplitude control circuitry, power amplification circuit;
3.2] be energized, the number of turns of size of current I and coil and the size of equivalent driving force F meet relations I=F/NBL, and wherein, N is the number of turns of coil, and B is the magnetic field intensity of permanent magnet, and I is the size of current passed in coil, and L is the length of electrified wire.
3. the measuring state monitoring method of a kind of coriolis mass flowmeters according to claim 2, it is characterized in that: step 3.1] in, phase-shift circuit comprises operational amplifier, feedback resistance R1, resistance R2, resistance Rx, electric capacity c, the positive input terminal of operational amplifier connects the output of flow transmitter by resistance Rx, the positive input terminal of operational amplifier is by electric capacity c ground connection, the negative input end of operational amplifier connects the output of flow transmitter by resistance R2, the negative input end of operational amplifier also connects the output terminal of operational amplifier by feedback resistance R1, operational amplifier exports the input connecing amplitude control circuitry.
4. the measuring state monitoring method of a kind of coriolis mass flowmeters according to Claims 2 or 3, it is characterized in that: step 3.1] in, power amplification circuit comprises triangular-wave generator, sinusoidal synthesizer, comparator circuit, Bridge output stage circuit and low-pass filter circuit, the output terminal of triangular-wave generator and sinusoidal synthesizer is connected to the input end of comparator circuit, the output terminal of comparator circuit is connected with low-pass filter circuit by Bridge output stage circuit, low-pass filter circuit exports and connects the first driving former-wound coil and the second driving former-wound coil respectively, sinusoidal synthesizer connects the output of amplitude control circuitry.
5. the measuring state monitoring method of a kind of coriolis mass flowmeters according to claim 4, it is characterized in that: step 3.1] in, amplitude control circuitry comprises the filtering circuit and potentiometer that are connected on phase-shift circuit output terminal successively, and the output of potentiometer is connected with the input of sinusoidal synthesizer.
6. the measuring state monitoring device of a coriolis mass flowmeters, it is characterized in that: the bringing device comprising equivalent driving force F, the action effect of equivalence driving force F is identical with the action effect of coriolis force Fc, applying position and the size of equivalence driving force F meet moment condition 2Fd=T, wherein d is the distance of application point to the axis of symmetry of vibrating tube of equivalent driving force, and T is the Coriolis moment of couple.
7. the measuring state monitoring device of coriolis mass flowmeters according to claim 6, is characterized in that: the bringing device of equivalent driving force F comprises the first analog-driven coil, the second analog-driven coil, the first permanent magnet, the second permanent magnet, phase-shift circuit, amplitude control circuitry and power amplification circuit; For the coriolis mass flowmeters of single-tube, vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of vibrating tube and the second permanent magnet, first permanent magnet and the second analog-driven coil are fixed on the relative position of coriolis mass flowmeters shell, make the first permanent magnet stretch into the first analog-driven coil inside, the second permanent magnet stretches into the second analog-driven coil inside; For the coriolis mass flowmeters of double-tube type, wherein a vibrating tube is fixed with about the symmetrical axisymmetric first analog-driven coil of this vibrating tube and the second permanent magnet, the relative position of another root vibrating tube is fixed with the first permanent magnet and the second analog-driven coil, first permanent magnet stretches into the first analog-driven coil inside, and the second permanent magnet stretches into the second analog-driven coil inside; One tunnel of flow transmitter exports the drive singal that the drive coil being connected to vibration transducer provides normal work, another road of flow transmitter is exported and is connected with the first analog-driven coil and the second analog-driven coil respectively by phase-shift circuit, amplitude control circuitry, power amplification circuit successively, and the input signal access direction of the first analog-driven coil and the second analog-driven coil is contrary.
8. the measuring state monitoring device of the coriolis mass flowmeters according to claim 6 or 7, it is characterized in that: described phase-shift circuit comprises operational amplifier, feedback resistance R1, resistance R2, resistance Rx, electric capacity c, the positive input terminal of operational amplifier connects the output of flow transmitter by resistance Rx, the positive input terminal of operational amplifier is by electric capacity c ground connection, the negative input end of operational amplifier connects the output of flow transmitter by resistance R2, the negative input end of operational amplifier also connects the output terminal of operational amplifier by feedback resistance R1, operational amplifier exports the input connecing amplitude control circuitry.
9. the measuring state monitoring device of coriolis mass flowmeters according to claim 8, it is characterized in that: described power amplification circuit comprises triangular-wave generator, sinusoidal synthesizer, comparator circuit, Bridge output stage circuit and low-pass filter circuit, the output terminal of triangular-wave generator and sinusoidal synthesizer is connected to the input end of comparator circuit, the output terminal of comparator circuit is connected with low-pass filter circuit by Bridge output stage circuit, low-pass filter circuit exports and connects the first driving former-wound coil and the second driving former-wound coil respectively, sinusoidal synthesizer connects the output of amplitude control circuitry.
10. the measuring state monitoring device of coriolis mass flowmeters according to claim 9, it is characterized in that: described amplitude control circuitry comprises the filtering circuit and potentiometer that are connected on phase-shift circuit output terminal successively, and the output of potentiometer is connected with the input of sinusoidal synthesizer.
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| PCT/CN2014/073978 WO2015143613A1 (en) | 2014-03-24 | 2014-03-24 | Method and apparatus for monitoring measurement state of coriolis mass flowmeter |
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| CN (1) | CN104981684B (en) |
| RU (1) | RU2656294C2 (en) |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107131905A (en) * | 2016-02-26 | 2017-09-05 | 高准公司 | Detect two or more gauge assemblies |
| CN111226575A (en) * | 2018-11-28 | 2020-06-05 | 株式会社久保田 | Harvester and flow calculation method |
| CN113899431A (en) * | 2021-09-07 | 2022-01-07 | 上海裕凡实业有限公司 | Mobile flow online calibration system |
| CN118089893A (en) * | 2024-04-28 | 2024-05-28 | 西南石油大学 | Coriolis flowmeter zero drift early warning monitoring method and monitoring device |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119023036A (en) * | 2024-08-14 | 2024-11-26 | 西安理工大学 | Coriolis flowmeter wall failure detection method based on steady-state response |
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| CN113899431A (en) * | 2021-09-07 | 2022-01-07 | 上海裕凡实业有限公司 | Mobile flow online calibration system |
| CN118089893A (en) * | 2024-04-28 | 2024-05-28 | 西南石油大学 | Coriolis flowmeter zero drift early warning monitoring method and monitoring device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104981684B (en) | 2018-06-05 |
| RU2015151900A (en) | 2017-06-08 |
| RU2656294C2 (en) | 2018-06-04 |
| WO2015143613A1 (en) | 2015-10-01 |
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