CN104132701B - A kind of adaptive coriolis mass flowmeters phase difference detection method - Google Patents
A kind of adaptive coriolis mass flowmeters phase difference detection method Download PDFInfo
- Publication number
- CN104132701B CN104132701B CN201410362986.7A CN201410362986A CN104132701B CN 104132701 B CN104132701 B CN 104132701B CN 201410362986 A CN201410362986 A CN 201410362986A CN 104132701 B CN104132701 B CN 104132701B
- Authority
- CN
- China
- Prior art keywords
- sine wave
- signal
- wave signal
- primary sinusoid
- phase difference
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 26
- 230000003044 adaptive effect Effects 0.000 title claims abstract description 8
- 238000006243 chemical reaction Methods 0.000 claims abstract description 22
- 238000007620 mathematical function Methods 0.000 claims abstract description 8
- 238000012545 processing Methods 0.000 claims description 16
- 238000001914 filtration Methods 0.000 claims description 12
- 238000011282 treatment Methods 0.000 claims description 6
- 238000000034 method Methods 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 4
- 238000005303 weighing Methods 0.000 claims description 2
- 238000005259 measurement Methods 0.000 abstract description 8
- 230000008901 benefit Effects 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 238000013507 mapping Methods 0.000 description 1
- 230000010358 mechanical oscillation Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000010363 phase shift Effects 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Landscapes
- Measuring Volume Flow (AREA)
Abstract
The present invention provides a kind of adaptive coriolis mass flowmeters phase difference detection method, for detecting the phase difference between primary sinusoid signal and the second sine wave signal, handles this two paths of signals first so that the amplitude of two signals is identical with frequency；The two paths of signals carries out plus computing, obtains the 3rd sine wave signal and to the signal transacting；Primary sinusoid signal and the second sine wave signal carry out multiplication with the 3rd sine wave signal respectively, respectively obtain two-way frequency conversion sine wave signal；Two-way frequency conversion sine wave signal to carry out subtracting computing, obtain the mathematical function based on phase difference between primary sinusoid signal and the second sine wave signal.The present invention can reach ns levels by accurate detection sensor phase difference so as to improve measurement accuracy and the degree of accuracy, its measurement accuracy to greatest extent.
Description
Technical field
The present invention relates to a kind of adaptive coriolis mass flowmeters phase difference detection method, suitable for based on Ke Liao
The signal detection of sharp mass flowmenter and extraction.
Background technology
Coriolis mass flowmeters are generally all made up of two parts：Sensor and transmitter.Apply on the market now
Mass flowmenter is all made up of two parallel vibration tubes, and sensor vibration tube can make different structure, such as U-shape structure, T junction
Structure, S types structure, micro-bend type, straight pipe type etc., the sensor of different structure has respective advantage and disadvantage, is adapted to different application scenarios.
One group of drive component being made up of magnet and coil is installed in sensor vibration tube middle part, the drive component continually carries
Energy supply amount, two vibration tubes are allowed ceaselessly to do free vibration on intrinsic frequency point, the component is exciting part；In parallel vibration tube
Import and export both sides are fixed with two electromagnetic assemblies being made up of magnet and coil, and the component vibrates with the vibration of vibration tube, together
When mechanical oscillation are converted into electric signal, for subsequent conditioning circuit processing, this partial circuit is pick-up circuit.Here it is sensor generation
Most original sine wave signal, later all signal transacting carried out both for the signal.
Under normal circumstances, when fluid transfixion in sensor vibration tube, two-way pick-up signal is that frequency and amplitude are complete
Consistent sine wave, two sine wave signal phase differences are zero.When medium has flowing in vibration tube, two sine wave signals are deposited
In certain phase difference, flow is bigger, and phase difference is also bigger.The size of mass flow and the phase difference of two-way sine wave signal into
Proportional relation.The phase difference is accurately detected, with regard to the parameter such as mass flow of fluids within pipes this moment, mass flow can be calculated
The operation principle of meter is all based on this.
Traditional zero passage detection mensuration is limited to the accuracy of detection of phase difference, is limited the measurement accuracy of flowmeter.Will
Think fundamentally to improve the measurement accuracy of flowmeter, it is necessary to find a kind of new detection and method for extracting signal.
The content of the invention
The present invention provides a kind of adaptive coriolis mass flowmeters phase difference detection method, to solve in the prior art
The problem of limited to the accuracy of detection of phase difference.
The embodiment of the invention discloses a kind of adaptive coriolis mass flowmeters phase difference detection method, for detecting
Phase difference between primary sinusoid signal and the second sine wave signal, the detection method include：
The primary sinusoid signal and second sine wave signal are handled, so that the primary sinusoid signal and institute
The amplitude for stating the second sine wave signal is identical with frequency；
The treated primary sinusoid signal and the second sine wave signal carry out plus computing, obtains the 3rd sine wave
Signal, the 3rd sine wave signal is handled so that the 3rd sine wave signal is believed with described first and second sine wave
Number amplitude it is identical with frequency；
The primary sinusoid signal and the 3rd sine wave signal carry out multiplication, obtain the first change frequency sine-wave letter
Number；Second sine wave signal and the 3rd sine wave signal carry out multiplication, obtain the second frequency conversion sine wave signal；With
And
The first frequency conversion sine wave signal and the second frequency conversion sine wave signal carry out subtracting computing, obtain based on described
The mathematical function of phase difference between primary sinusoid signal and second sine wave signal, and institute is obtained based on the mathematical function
State the phase difference between primary sinusoid signal and second sine wave signal.
According to such scheme, in the first possible implementation, the primary sinusoid signal and described are handled
In the step of two sine wave signals, the primary sinusoid signal and the second sine wave signal first amplified filtering, then enter
The double Balance Treatments of row standardization.
According to the first possible implementation of such scheme, in second of possible implementation, the standard
Changing double flat weighing apparatus processing procedure includes：
First preset standard magnitude of voltage of the primary sinusoid signal in its signal processing channel and described first is just
The maximum amplitude of string ripple signal waveform voltage carries out division operation, obtains first waveform regulation coefficient；
Second preset standard magnitude of voltage of second sine wave signal in its signal processing channel and described second is just
The maximum amplitude of string ripple signal waveform voltage carries out division operation, obtains the second waveform regulation coefficient；
The primary sinusoid is believed respectively according to the first waveform regulation coefficient and the second waveform regulation coefficient
Number and second sine wave signal carry out range-adjusting so that the amplitude phase of primary sinusoid signal and the second sine wave signal
Together.
According to such scheme, in the third possible implementation, the primary sinusoid signal, second sine
Ripple signal carries out multiplication with the 3rd sine wave signal using multiplier.
According to such scheme, in the 4th kind of possible implementation, the first frequency conversion sine wave signal and described
Two frequency conversion sine wave signals carry out using micro- narrow-band filtering technology to be filtered processing before subtracting computing.
The present invention uses above-mentioned technical proposal, can reach following beneficial effect：
（1）The present invention is standardized double Balance Treatments to original sine ripple signal, ensure that sine wave signal is preferable and becomes
There is identical amplitude before frequency, the error of sine wave signal conversion can be effectively reduced；
（2）It is also right while performing mathematical calculations when carrying out frequency conversion to sine wave signal using multiplier in the present invention
Random noise, white noise etc. have filtering function；
（3）The present invention is handled frequency variation signal using micro- narrow-band filtering technology, and response is fast, filters out caused by frequency conversion
Harmonic wave simultaneously removes random noise, white noise and low-frequency disturbance, can also eliminate the interference that supply frequency is disturbed and more than 1Hz is electric；
（4）Method of the present invention is unrelated with frequency, and the sensor of any frequency is applicable, as a result constant；
（5）The present invention is by accurate detection sensor phase difference, so that measurement accuracy and the degree of accuracy are improved to greatest extent, its
Measurement accuracy can reach ns levels.
Brief description of the drawings
Technical scheme in order to illustrate the embodiments of the present invention more clearly, make required in being described below to embodiment
Accompanying drawing is briefly described, it should be apparent that, drawings in the following description are only some embodiments of the present invention, for
For those of ordinary skill in the art, on the premise of not paying creative work, other can also be obtained according to these accompanying drawings
Accompanying drawing.
Fig. 1 is the phase difference detection method flow chart of present pre-ferred embodiments.
Embodiment
To make the object, technical solutions and advantages of the present invention clearer, below in conjunction with accompanying drawing to embodiment party of the present invention
Formula is described in further detail.
As shown in figure 1, it is the phase difference detection method flow chart of the embodiment of the present invention.Adaptive section disclosed by the invention
Li Aoli mass flowmenter phase difference detection methods, for detecting the phase between primary sinusoid signal and the second sine wave signal
Difference, the detection method comprise the following steps：
First, primary sinusoid signal U is handledaWith the second sine wave signal Ub, so that primary sinusoid signal UaWith second
Sine wave signal UbAmplitude it is identical with frequency.
In this preferred embodiment, U is seta=a (sin (wt+ ∮/2)), Ub=b(sin(wt-∮/2))=a(sin(wt-∮/2))+
△ (sin (wt- ∮/2)), in formula, a is primary sinusoid amplitude, and b is the second sinusoidal magnitude, wherein b=a+ △, △ first
Difference in magnitude between sine wave signal a and the second sine wave signal b, w are angular frequency, and t is the time, and ∮ is the primary sinusoid and the
Phase difference between two sine waves.
In the step, primary sinusoid signal UaWith the second sine wave signal UbFirst amplified filtering, then be standardized double
Balance Treatment.Wherein, amplify filtering and this two-way sine wave signal is respectively transmitted to its respective signal processing channel A
In B, carry out accurate amplification, filtering denoising Processing, filter out the waveforms such as low-frequency disturbance, higher hamonic wave, white noise carry it is useless
Signal, sine wave signal U be amplified, smooth, realaAnd Ub；Sine wave signal is standardized double Balance Treatments
Including following process：
Primary sinusoid signal UaThe first preset standard magnitude of voltage U in its signal processing channel AStandardIt is sinusoidal with first
Ripple signal UaThe maximum amplitude of waveform voltage carries out division operation, obtains first waveform regulation coefficient；
Second sine wave signal UbThe second preset standard magnitude of voltage U in its signal processing channel BStandardIt is sinusoidal with second
Ripple signal UbThe maximum amplitude of waveform voltage carries out division operation, obtains the second waveform regulation coefficient；
According to the first waveform regulation coefficient and the second waveform regulation coefficient respectively to the primary sinusoid signal Ua
With the second sine wave signal UbRange-adjusting is carried out, so that primary sinusoid signal UaWith the second sine wave signal UbWidth
It is worth identical.
The double Balance Treatments of standardization above have identical amplitude before ensure that sine wave signal ideal frequency conversion, can effectively subtract
Small-signal mapping fault.
Secondly, treated primary sinusoid signal UaWith the second sine wave signal UbCarry out adding computing, obtaining the 3rd just
String ripple signal Uc, handle the 3rd sine wave signal UcSo that the 3rd sine wave signal UcWith primary sinusoid signal UaAnd second just
String ripple signal UbAmplitude it is identical with frequency.
In the step, the 3rd sine wave signal Uc=Ua+Ub=a(sin(wt+∮/2))+a(sin(wt-∮/2))+
△(sin(wt-∮/2))=（2a+△）*（cos∮/2）*coswt+△（sin∮/2）*sinwt.
To the 3rd sine wave signal UcIt is standardized, obtains and primary sinusoid signal UaAnd second sine wave letter
Number UbAmplitude and frequency identical signal, the 3rd sine wave signal U nowcIt can be used as local oscillated signal.
To U in this stepcIt is to have identical amplitude and frequency before ensureing signal operation that signal, which is standardized,.
So far, existing three original sine ripple signal U that amplitude-frequency value is equal, phase is differenta、UbAnd Uc。
Again, primary sinusoid signal UaWith the 3rd sine wave signal UcMultiplication is carried out, obtains the first change frequency sine-wave letter
Number Uac；Second sine wave signal UbWith the 3rd sine wave signal UcMultiplication is carried out, obtains the second frequency conversion sine wave signal Ubc。
In the step, multiplication is carried out using multiplier.Wherein, Uac=Ua*Uc=k(sin∮/2)*(cos∮/2)
+k(cos2∮/2) * sin2wt+k (sin ∮/2) * cos (∮/2) cos2wt, Ubc=Ub*Uc=k(sin∮/2)*(cos∮
/2)+k(cos2∮/2)*sin2wt-k(sin∮/2)*cos(∮/2)cos2wt。
In formula, k is constant.
Multiplication is carried out using multiplier in the step, while performing mathematical calculations, also to random noise, white noise
Etc. there is filtering function.
Finally, the first frequency conversion sine wave signal UacWith the second frequency conversion sine wave signal UbcCarry out subtracting computing, obtain based on the
One sine wave signal UaWith the second sine wave signal UbBetween phase difference mathematical function, and obtaining first just based on the mathematical function
String ripple signal UaWith the second sine wave signal UbBetween phase difference.
In the step, Uac-Ubc=ksin ∮, in phase angle ∮<In the range of 2 ° of normal discharge, the mathematical function and phase difference
It is linear.
In this step, the first frequency conversion sine wave signal UacWith the second frequency conversion sine wave signal UbcIt is first before carrying out subtracting computing
Processing is filtered using micro- narrow-band filtering technology.Signal is handled using micro- narrow-band filtering technology, response is fast, filters out change
Harmonic wave caused by frequency simultaneously removes random noise, white noise and low-frequency disturbance, can also eliminate supply frequency interference and more than 1Hz
The interference of electricity, such as Switching Power Supply, rectifier and radar.
The present invention can be offset using the full symmetric processing method of two paths of signals in the finally mathematical operation of extraction phase
Phase shift caused by common mode interference signal and wave filter itself in input signal；And by accurate detection sensor phase difference, from
And measurement accuracy and the degree of accuracy are improved to greatest extent, its measurement accuracy can reach ns levels.
Detection method of the present invention is unrelated with frequency, and the sensor of any frequency is applicable, as a result constant.
The foregoing is only presently preferred embodiments of the present invention, be not intended to limit the invention, it is all the present invention spirit and
Within principle, any modification, equivalent substitution and improvements made etc., it should be included in the scope of the protection.
Claims (5)
- A kind of 1. adaptive coriolis mass flowmeters phase difference detection method, for detecting primary sinusoid signal and second Phase difference between sine wave signal, it is characterised in that the detection method includes：The primary sinusoid signal and second sine wave signal are handled, so that the primary sinusoid signal and described The amplitude of two sine wave signals is identical with frequency；The treated primary sinusoid signal and the second sine wave signal carry out plus computing, obtains the 3rd sine wave letter Number, the 3rd sine wave signal is handled so that the 3rd sine wave signal after processing and described first and institute after processing The amplitude for stating the second sine wave signal is identical with frequency；The primary sinusoid signal and the 3rd sine wave signal carry out multiplication, obtain the first frequency conversion sine wave signal； Second sine wave signal and the 3rd sine wave signal carry out multiplication, obtain the second frequency conversion sine wave signal；The first frequency conversion sine wave signal and the second frequency conversion sine wave signal carry out subtracting computing, obtain being based on described first The mathematical function of phase difference between sine wave signal and second sine wave signal, and obtain described based on the mathematical function Phase difference between one sine wave signal and second sine wave signal.
- 2. detection method according to claim 1, it is characterised in that handle the primary sinusoid signal and described second In the step of sine wave signal, the primary sinusoid signal and the amplified laggard rower of filtering of second sine wave signal are accurate Change double Balance Treatments.
- 3. detection method according to claim 2, it is characterised in that the standardization double flat weighing apparatus processing procedure includes：First preset standard magnitude of voltage of the primary sinusoid signal in its signal processing channel and the primary sinusoid The maximum amplitude of signal waveform voltage carries out division operation, obtains first waveform regulation coefficient；Second preset standard magnitude of voltage of second sine wave signal in its signal processing channel and second sine wave The maximum amplitude of signal waveform voltage carries out division operation, obtains the second waveform regulation coefficient；According to the first waveform regulation coefficient and the second waveform regulation coefficient respectively to the primary sinusoid signal and Second sine wave signal carries out range-adjusting, so that the amplitude of primary sinusoid signal and the second sine wave signal is identical.
- 4. the detection method according to claim 1, it is characterised in that the primary sinusoid signal and described second is just String ripple signal carries out multiplication with the 3rd sine wave signal using multiplier.
- 5. the detection method according to claim 1, it is characterised in that the first frequency conversion sine wave signal and described Two frequency conversion sine wave signals carry out using micro- narrow-band filtering technology to be filtered processing before subtracting computing.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410362986.7A CN104132701B (en) | 2014-07-29 | 2014-07-29 | A kind of adaptive coriolis mass flowmeters phase difference detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410362986.7A CN104132701B (en) | 2014-07-29 | 2014-07-29 | A kind of adaptive coriolis mass flowmeters phase difference detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104132701A CN104132701A (en) | 2014-11-05 |
| CN104132701B true CN104132701B (en) | 2017-11-28 |
Family
ID=51805472
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410362986.7A Active CN104132701B (en) | 2014-07-29 | 2014-07-29 | A kind of adaptive coriolis mass flowmeters phase difference detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104132701B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4843890A (en) * | 1988-07-08 | 1989-07-04 | Micro Motion, Incorporated | Coriolis mass flow rate meter having an absolute frequency output |
| JP2001116602A (en) * | 1999-10-18 | 2001-04-27 | Oval Corp | Coriolis mass flowmeter |
| CN1532529A (en) * | 2003-03-20 | 2004-09-29 | 加 黄 | Phase difference detection circuit for coriolis'force mass flow meter |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0702212A3 (en) * | 1994-09-13 | 1996-08-14 | Fuji Electric Co Ltd | Phase shift measurement device and associated mass flow meter |
| US6051996A (en) * | 1998-09-30 | 2000-04-18 | Lucent Technologies Inc. | Phase detector |
| JP4436884B1 (en) * | 2009-02-06 | 2010-03-24 | 株式会社オーバル | Signal processing method, signal processing apparatus, and Coriolis flow meter |
| CN101832803B (en) * | 2010-03-31 | 2012-01-11 | 太原太航流量工程有限公司 | Coriolis mass flow meter digital signal processing method |
| CN103353320B (en) * | 2013-07-03 | 2016-07-06 | 太原太航科技有限公司 | Coriolis mass flowmeter signal processing method based on mixing algorithm |
-
2014
- 2014-07-29 CN CN201410362986.7A patent/CN104132701B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4843890A (en) * | 1988-07-08 | 1989-07-04 | Micro Motion, Incorporated | Coriolis mass flow rate meter having an absolute frequency output |
| JP2001116602A (en) * | 1999-10-18 | 2001-04-27 | Oval Corp | Coriolis mass flowmeter |
| CN1532529A (en) * | 2003-03-20 | 2004-09-29 | 加 黄 | Phase difference detection circuit for coriolis'force mass flow meter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN104132701A (en) | 2014-11-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101806832B (en) | Measuring method for frequencies of low-frequency signals | |
| CN101949683B (en) | Eddy current displacement detection method | |
| CN102798748B (en) | Method for calculating amplitude and phase of alternating-voltage signal based on iteration Fourier transform | |
| CN111351535B (en) | A kind of signal processing method of high frequency sine wave excitation electromagnetic flowmeter | |
| CN103558436A (en) | Method for network voltage amplitude, frequency and phase angle detection based on one-phase phase-locked loop algorithm | |
| CN104259081A (en) | Frequency tracking method of piezoelectric transducer and frequency tracking system thereof | |
| CN105676008A (en) | A digital electric field sensor | |
| CN105865547A (en) | Electromagnetic flowmeter and method of using same | |
| CN103399204A (en) | Rife-Vincent (II) window interpolation FFT (Fast Fourier Transform)-based harmonic and inter-harmonic detection method | |
| CN102753982A (en) | A method of subsynchronous resonance detection | |
| CN101832803B (en) | Coriolis mass flow meter digital signal processing method | |
| CN116337191B (en) | Phase difference calculation method for coriolis flowmeter with mixed zero-crossing detection and quadrature demodulation | |
| CN104236646B (en) | Ultrasonic flowmeter and ultrasonic flow measuring method | |
| CN205080193U (en) | Non -contact fluid impedance measurement device based on annular structure | |
| CN103412209B (en) | A kind of off resonance degree detection method of tuned filter | |
| CN104132701B (en) | A kind of adaptive coriolis mass flowmeters phase difference detection method | |
| CN110514258A (en) | A New Electromagnetic Flowmeter | |
| CN105092969B (en) | A kind of phase frequency matching process of phase difference estimation | |
| CN107643442A (en) | A kind of new high-precision zero passage detection method | |
| CN105301365B (en) | The anti-measuring device of contactless fluid resistance and method | |
| CN204165597U (en) | For the echoed signal modulate circuit of flow quantity detecting system | |
| CN205080194U (en) | Non -contact fluid impedance measurement device based on radial structure | |
| CN103344287A (en) | Electromagnetic flow meter power frequency noise restraining method based on zero point detection | |
| CN106771584A (en) | A kind of harmonic detecting method for being applied to power distribution network | |
| CN204536249U (en) | Based on the oil-water two-phase flow moisture content meter of frequency sweep complex impedance measurement |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20210118 Address after: 030006 Shanxi Province, Taiyuan city district and State Road No. 137 Patentee after: Taiyuan Taihang Technology Co.,Ltd. Patentee after: TAIYUAN TAIHANG FLOWRATE ENGINEERING Co.,Ltd. Address before: 7 / F, Taihang building, 137 Bingzhou South Road, Xiaodian District, Taiyuan City, Shanxi Province Patentee before: Taiyuan Taihang Technology Co.,Ltd. |
|
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220622 Address after: 030000 7th floor, Taihang building, No. 137, Bingzhou South Road, Xiaodian District, Taiyuan City, Shanxi Province Patentee after: Taiyuan Taihang Technology Co.,Ltd. Patentee after: Taiyuan Taihang dexen Automatic Control Engineering Co., Ltd Address before: 030006 Shanxi Province, Taiyuan city district and State Road No. 137 Patentee before: Taiyuan Taihang Technology Co.,Ltd. Patentee before: Taiyuan Taihang Flow Engineering Co., Ltd |