WO2016173329A1

WO2016173329A1 - Ultrasonic flow measurement method and apparatus based on side-tone phase measurement

Info

Publication number: WO2016173329A1
Application number: PCT/CN2016/076357
Authority: WO
Inventors: 陈勇; 黄奕勇; 陈小前; 郑崇光
Original assignee: 中国人民解放军国防科学技术大学
Priority date: 2015-04-30
Filing date: 2016-03-15
Publication date: 2016-11-03
Also published as: CN105115552B; CN105115552A

Abstract

An ultrasonic flow measurement method and apparatus based on side-tone phase measurement; on the basis of a fluid flow rate estimate, obtaining a minimum side-tone frequency with a difference between the phase variation of the ultrasonic wave transmission in the fluid along the countercurrent direction and the phase variation along the downstream direction not exceeding 180° (S101); on the basis of the minimum side-tone frequency, selecting at least one group of side-tone frequencies (S103); on the basis of the measurement phase difference between the phase variation of the ultrasonic wave transmission in the fluid along the countercurrent direction and the phase variation along the downstream direction in each group of side-tone frequencies, acquiring the actual phase difference corresponding to said group of side-tone frequencies (S105); and on the basis of any one group side-tone frequencies and the actual phase difference corresponding to said group of side-tone frequencies, calculating the fluid flow (S107); thus solving the problem in the prior art of slow flowmeter response caused by the need for multiple numbers of side-tones, improving flowmeter response speed and reducing the system design complexity.

Description

Ultrasonic flow measuring method and device based on side sound phase measurement

Technical field

The invention relates to the field of ultrasonic flow measurement, in particular to a method and a device for measuring ultrasonic flow based on side sound phase measurement.

Background technique

The ultrasonic flowmeter utilizes the significant difference between the sound wave and the countercurrent flow in the pipeline flow, and obtains the average flow velocity information of the pipeline by processing the acoustic wave signal, thereby predicting the pipeline flow flow. Ultrasonic flowmeters have the advantages of not invading the fluid to be measured, moving parts, and not affecting fluid flow, and are widely used in various industrial fields. In the aerospace sector, ESA has developed a pulse wave-based ultrasonic flowmeter for space pipeline measurement, which has been loaded as a load on the Alphabus communications satellite launched by ESA in July 2013.

In the pulse wave system, the energy is greatly attenuated by the bandpass filtering of the transducer. Therefore, the signal-to-noise ratio (SNR) of the received signal will be low, making the measurement of the propagation time more difficult. In addition, due to industrial production, there are inconsistencies in the ultrasonic probes, so that the resonance frequencies are inconsistent and vary with changes in the external environment. Inconsistencies in the resonant frequency of the probe will result in significant measurement errors. In addition, the presence of high-order modes in the process of pipeline acoustic wave propagation makes the detection of direct waves more difficult. For continuous wave systems, the energy of continuous sound waves can be large. The probe is forced to vibrate under the continuous wave system, so there is no frequency inconsistency. The existing flow measurement method based on the continuous wave system is only applicable to the case where there is no fuzzy number, and the measurement range is limited. In order to obtain a larger measurement range, a technique based on a continuous wave and a pulse wave system has been proposed, but the frequency inconsistency in the method has not been solved.

The continuous wave flow measurement method based on sidetone measurement in the prior art solves the problem of measuring the fuzzy number by using the phase of different sidetones, and theoretically expands the flow measurement range of the continuous wave system. However, the method unambiguously blurs the propagation time of the forward and reverse currents, resulting in multiple sidetones in the measurement process, and the system design is more complicated, which reduces the response speed of the flowmeter. Therefore, there is a need to provide a method and apparatus for measuring ultrasonic flow based on side sound phase measurement which can reduce the number of side notes and thereby improve the response speed of the flow meter.

Summary of the invention

The invention provides an ultrasonic flow measurement method and device based on side sound phase measurement, so as to solve the problem that the ultrasonic flow measurement method and the device based on the side sound phase measurement need to have multiple side sounds, resulting in slow response speed of the flow meter. technical problem.

According to an aspect of the present invention, a method for measuring ultrasonic flow based on side sound phase measurement is provided, comprising:

Obtaining, according to the fluid flow estimation value, a minimum side audio frequency of the ultrasonic wave propagating the phase change value in the countercurrent direction in the fluid and the phase change value in the downstream direction not exceeding 180°;

Selecting at least one set of side audio frequencies based on a minimum side audio frequency;

Obtaining an actual phase difference value corresponding to the set of side audio frequencies according to a measured phase difference value of the ultrasonic wave propagating the phase change value in the counterflow direction and the phase change value propagating in the downstream direction in the fluid at each side audio frequency rate;

The fluid flow is calculated based on any set of side audio frequencies and actual phase differences corresponding to the set of side audio frequencies.

Further, selecting at least one set of side audio frequencies based on the minimum side audio frequency includes:

Selecting a side audio frequency that does not exceed the minimum side audio frequency as the first group side audio frequency, and setting a preset maximum side audio frequency greater than the minimum side audio frequency as the maximum group side audio frequency;

Determining a progressive multiple between adjacent group side audio frequencies based on the absolute error of the ultrasonic phase measurement;

The other group side audio frequencies between the first group side audio frequency and the maximum group side audio rate are determined according to a progressive multiple between adjacent group side audio frequencies.

Further, the progressive multiple between the adjacent group side audio frequencies satisfies:

Where K(f _i ,f _i+1 ) represents the progressive multiple (i≥1) between the i-th group and the i+1th group side audio frequency, and δ represents the ultrasonic phase measurement absolute error.

Further, the actual phase difference corresponding to the set of side audio frequencies is obtained according to the measured phase difference value of the ultrasonic wave propagating the phase change value in the counterflow direction and the phase change value propagating along the downstream direction in the fluid at each side audio frequency rate. The calculation formula is:

Where ΔΦ(f _i+1 ) represents the actual phase difference value (i≥1) of the _i+ 1th group side audio frequency, and K(f _i ,f _i+1 ) represents the i-th group and the i+1th group. The progressive multiple between the side audio frequencies, ΔΦ ^frac (f _i ) represents the measured phase difference value of the propagation phase change value of the ultrasonic wave in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave in the i-th group side audio frequency. [X] _0.5 represents a rounding operation on X and satisfies ΔΦ(f ₁ )=ΔΦ ^frac (f ₁ ).

Further, any set of side audio frequencies used to calculate fluid flow in the fluid flow is calculated to be equal to the maximum set side audio frequency based on any set of side audio frequencies and actual phase differences corresponding to the set of side audio frequencies.

According to another aspect of the present invention, there is also provided an ultrasonic flow measuring device for side tone phase measurement, comprising:

a minimum side audio frequency determining device, configured to obtain, according to the fluid flow rate estimation value, a minimum side audio frequency in which the ultrasonic wave propagates the phase change value in the reverse flow direction in the fluid and the phase change value in the downstream direction does not exceed 180°;

a plurality of sets of side tone rate determining means for selecting at least one set of side audio frequencies based on a minimum side audio frequency;

An actual phase difference obtaining device for propagating the ultrasonic wave in a countercurrent direction in the fluid according to each set of side audio frequencies The bit change value and the measured phase difference value of the phase change value propagating along the downstream direction are obtained as an actual phase difference value corresponding to the set of side audio frequencies;

A fluid flow obtaining device for calculating a fluid flow rate based on any set of side audio frequencies and an actual phase difference corresponding to the set of side audio frequencies.

Further, the plurality of sets of sidetone rate determining means includes:

a first group and a maximum group side audio frequency determining device, configured to select a side audio frequency that does not exceed a minimum side audio frequency as a first group side audio frequency, and a preset maximum side audio frequency that is greater than a minimum side audio frequency As the maximum group side audio rate;

a progressive multiple determining means for determining a progressive multiple between adjacent group side audio frequencies based on the ultrasonic phase measurement absolute error;

The other groups of side tone rate determining means are configured to determine other group side audio frequencies between the first group side audio frequency and the maximum group side audio frequency according to a progressive multiple between adjacent group side audio frequencies.

Further, the progressive multiple between the adjacent group side audio frequencies in the progressive multiple determining device satisfies:

Further, the actual phase difference obtaining means obtains the measured phase difference value of the ultrasonic wave propagation phase in the counterflow direction and the measured phase difference value of the phase change value in the downstream direction according to each set of side audio frequencies The formula for calculating the actual phase difference corresponding to the frequency is:

Further, any set of side audio frequencies used to calculate fluid flow in the fluid flow determination device is equal to the maximum group side audio frequency.

The invention has the following beneficial effects:

The method and device for measuring ultrasonic flow based on side sound phase measurement according to the present invention, according to the fluid flow rate estimation value, the difference between the phase change value of the ultrasonic wave propagating in the counterflow direction in the fluid and the phase change value propagating along the downstream direction is not more than 180. Minimum side audio frequency, then select at least one set of side audio frequencies based on the minimum side audio rate, and finally ultrasound based on each set of side audio frequencies The wave propagates a phase change value in a countercurrent direction in the fluid and a measured phase difference value propagating the phase change value in a downstream direction to obtain an actual phase difference value corresponding to the set of side audio frequencies and according to any set of side audio frequencies and Calculating the fluid flow rate based on the actual phase difference corresponding to the side audio frequency, solving the technical problem that the prior art requires multiple sidetones to cause the flowmeter to respond slowly, improving the response speed of the flowmeter and reducing the system design complexity. .

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The invention will now be described in further detail with reference to the drawings.

DRAWINGS

The accompanying drawings, which are incorporated in the claims In the drawing:

1 is a flow chart showing a method for measuring an ultrasonic flow rate of a side sound phase measurement according to a preferred embodiment of the present invention;

2 is a schematic diagram of an ultrasonic flow measuring device for side tone phase measurement according to a preferred embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS:

1. Minimum side audio frequency determining device; 2. Multiple sets of side audio frequency determining devices; 3. Actual phase difference calculating device; 4. Fluid flow obtaining device.

detailed description

The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Referring to FIG. 1, a preferred embodiment of the present invention provides a method for measuring ultrasonic flow of side sound phase measurement, including

Step S101, determining, according to the fluid flow rate estimation value, a minimum side audio frequency that the ultrasonic wave propagates the phase change value in the reverse flow direction in the fluid and the phase change value in the downstream direction does not exceed 180°;

Step S103, selecting at least one set of side audio frequencies according to a minimum side audio frequency and a measurement accuracy requirement;

Step S105: Calculate the actual phase difference corresponding to the set of side audio frequencies according to the measured phase difference value of the ultrasonic wave propagating the phase change value in the counterflow direction and the phase change value in the downstream direction according to the ultrasonic frequency of each set of side audio frequencies. ;

Step S107, calculating a fluid flow rate according to any set of side audio frequencies and actual phase difference values corresponding to the set of side audio frequencies.

The method for measuring the ultrasonic flow rate of the side sound phase measuring according to the present invention is to obtain the minimum side of the difference between the phase change value of the ultrasonic wave propagating in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave not exceeding 180° according to the fluid flow rate estimation value. The audio frequency, then select at least one set of side audio frequencies according to the minimum side audio frequency and the measurement accuracy requirement, and finally, according to each set of side audio frequencies, the ultrasonic wave propagates the phase change value in the fluid in the countercurrent direction and the phase change value in the downstream direction according to the ultrasonic frequency of each group. The measured phase difference is obtained by calculating the actual phase difference corresponding to the set of side audio frequencies and calculating the fluid flow according to any set of side audio frequencies and the actual phase difference corresponding to the set of side audio frequencies, thereby solving the prior art needs. The number of side notes causes the technical problem of slow response of the flowmeter, improves the response speed of the flowmeter, and reduces the complexity of the system design.

Step S101: Calculate, according to the fluid flow rate estimation value, a minimum side audio frequency when the ultrasonic wave propagates the phase change value in the reverse flow direction in the fluid and the phase change value in the downstream direction does not exceed 180°.

For the ultrasonic flow measurement method using side sound phase measurement, since the forward and reverse phase changes of the ultrasonic wave generally exceed 360°, there is a problem of positive period ambiguity, which makes it impossible to perform measurement by a conventional method. Therefore, when using the multi-side sound method for solving, it is necessary to select the forward side phase corresponding to the minimum sidetone without the positive period blur phenomenon, that is, the phase difference satisfies [-180°, 180°]. The existing ultrasonic flow measurement method using side sound phase measurement is generally: (1) Calculate the downstream side audio frequency when the ultrasonic wave does not exceed 180° according to the fluid flow estimation value; (2) Estimate according to the fluid flow rate. The value is obtained as the countercurrent minimum side audio frequency when the ultrasonic countercurrent does not exceed 180°; (3) the plurality of sets of side audio frequencies and the countercurrent multiple sets of side audio frequencies are respectively determined according to the downstream side and the maximum set side audio frequencies of the forward and reverse current respectively. (4) separately calculating the actual phase difference corresponding to the maximum side audio frequency of the downstream multi-group side audio frequencies and the actual phase difference corresponding to the maximum side audio frequency of the multi-group side audio frequencies; (5) The actual phase difference corresponding to the actual phase difference value corresponding to the maximum side audio frequency of the multi-group side audio frequency and the actual phase difference corresponding to the maximum side audio frequency of the multi-group side audio frequency of the reverse current; (6) according to the The flow volume is calculated by countercurrent actual phase difference.

In this embodiment, for the forward propagation, the phase change of the acoustic wave in the process of the propagation distance L is:

Where L is the length of the pipe in the flowmeter, R is the pipe radius, C is the propagation velocity of the acoustic wave in the stationary fluid, and f is the acoustic wave frequency. The sound pressure propagates in the pipe fluid without considering the sound intensity, and the fluid flows. A stable uniform flow field U is formed. For countercurrent propagation, the phase change is:

Therefore, the difference between the phase change value of the ultrasonic wave propagating in the countercurrent direction in the fluid and the phase change value propagating in the downstream direction is:

When the difference ΔΦ(f) does not have a fuzzy number, it needs to satisfy ΔΦ(f)<π, assuming L=0.2m, C=1500m/s, when the fluid flow estimated value U=10m/s,

Can get the minimum side audio frequency

Here, the U value in U=10m/s is an estimated value of the range of the flow to be measured. By setting the fluid flow estimated value U=10m/s, the minimum side audio frequency can be obtained, and then the minimum side is passed. The audio frequency finally obtains the accurate value of the flow to be measured. In the prior art, the value of the minimum side audio frequency is obtained by using the phase difference Φ _down (f) and the reverse phase difference Φ _up (f), respectively:

It can be seen that the minimum side audio frequency obtained by directly calculating the minimum phase audio frequency when the ultrasonic wave propagates the phase change value in the countercurrent direction in the fluid direction and the phase change value in the downstream direction to calculate the difference does not exceed 180°. It is 281.3KHz, and the downstream minimum side audio frequency and the reverse current minimum side audio rate when calculating the forward and reverse current side audio frequencies respectively are 3.76KHz.

Step S103, selecting at least one set of side audio frequencies according to the minimum side audio frequency. Since the measured phase difference value of the ultrasonic flow measurement does not have a fuzzy number when less than or equal to the minimum side audio frequency, the minimum side audio frequency may be less than or equal to The measured phase difference values corresponding to them are used to determine the fluid flow rate. Generally speaking, the frequency of the minimum side audio frequency is small, and when the measurement accuracy of the fluid flow is obtained only by the less than or equal to the minimum side audio frequency and the measured phase difference thereof, in the actual flow measurement, multiple groups are usually selected. The side audio frequency is used for fluid flow measurement.

Optionally, in step S103, selecting at least one set of side audio frequencies according to a minimum side audio frequency and a measurement accuracy requirement includes: selecting a side audio frequency that does not exceed a minimum side audio frequency as the first set of side audio frequencies, which is preset to be greater than The maximum set side audio rate of the minimum side audio frequency is used as the maximum group side audio frequency.

According to the measurement accuracy, the maximum group side audio frequency is determined. For the phase detection algorithm, the phase measurement error can be characterized by δ _Φ , which is determined by the phase detection algorithm, and the corresponding flow measurement absolute error can be obtained as follows:

Define σ _V as the full scale (FSB) relative error of the flow measurement. The formula for calculating the relative error of full scale is as follows:

Further get the following formula:

In the case of full-scale U=10m/s, the full-scale relative error of flow measurement is σ _V ≤0.5%, and the absolute accuracy of phase measurement is δ _Φ =2°, then the side audio frequency to be achieved is satisfied.

In this embodiment, the maximum set side audio frequency f _M = 1 MHz is preset. In this embodiment, the first group side audio frequency is f ₁ =200 KHz, and the maximum group side audio frequency f _max =f _M =1 MHz, wherein, A set of side audio frequencies f ₁ =200KHz is less than the minimum side audio frequency of 281.3KHz, and the maximum group side audio frequency f _max is equal to the set side audio frequency f _M ; determining the between the adjacent group side audio frequencies according to the ultrasonic phase measurement absolute error The multiplier is determined; the other group side audio frequencies between the first group side audio rate and the maximum group side audio rate are determined according to the progressive multiple between the adjacent group side audio frequencies.

Alternatively, the selection of the progressive multiple K(f _i ,f _i+1 ) between adjacent group side audio frequencies will affect the effectiveness of the measurement method. Assume that the absolute error of the ultrasonic phase measurement is δ (the absolute error of the ultrasonic phase measurement of different ultrasonic measuring instruments is different), and the conditions for the iterative formula in the iterative process that there is no calculation error are:

Then, the progressive multiple K(f _i ,f _i+1 ) between the adjacent group side audio frequencies satisfies:

Where K(f _i ,f _i+1 ) represents the progressive multiple (i≥1) between the i-th group and the i+1th group side audio frequency, and δ represents the ultrasonic phase measurement absolute error. In this embodiment, the progressive multiple K(f _i , f _i+1 ) ≤ 5 is selected. According to the first group side audio frequency f ₁ =200KHz, the maximum group side audio frequency f _max =f _M =1MHz and K(f _i ,f _i+1 )≤5, the first group side audio frequency f ₁ = can be finally determined. 200KHz, the second group side audio frequency, that is, the maximum group side audio frequency is f ₂ =f _max =1MHz.

Compared with the prior art, when the downstream minimum side audio frequency and the reverse current minimum side audio frequency are both 3.76 KHz, and the progression multiples of each group are less than or equal to 5 and the fluid flow measurement accuracy is the same, the side sound needs to be selected. The number of frequency groups is much larger than the two sets of side tone rate groups of this embodiment. It can be seen that, in this embodiment, the method for directly dephasing the phase difference of the forward flow direction is adopted, and the method for defuzzifying the forward flow direction compared with the prior art greatly reduces the number of sound measurement under the premise of achieving the same measurement precision, thereby Reduce the complexity of the system and improve the system response speed.

Step S105: Calculate the actual phase difference corresponding to the set of side audio frequencies according to the measured phase difference value of the ultrasonic wave propagating the phase change value in the counterflow direction and the phase change value in the downstream direction according to the ultrasonic frequency of each set of side audio frequencies. . After measurement, the measured phase difference value of the first group side audio frequency f ₁ =200KHz of the embodiment is ΔΦ ^frac (f ₁ )=128°, and the measured phase difference value of the second group side audio frequency f ₂ =1MHz It is ΔΦ ^frac (f ₂ )=-80°.

Due to the ultrasonic flow measurement using side tone velocity measurement, the instrument can measure the phase range: [-180°, 180°], and the actual phase difference is usually calculated by measuring the phase difference when calculating the flow rate. Optionally, in this embodiment, the actual phase difference value of the other group side audio frequencies except the first group side audio frequency is sequentially obtained by using the superimposing method, because the first group side audio frequency is less than the minimum side audio frequency, that is, f ₁ =200KHz<281.3KHz, so there is no problem of fuzzy number in the first set of side audio frequencies. At this time, the first set of measured phase difference values can be used as the first set of actual phase difference values; The iterative formula for the actual phase difference is:

Where ΔΦ(f _i+1 ) represents the actual phase difference value (i≥1) of the _i+ 1th group side audio frequency, and K(f _i ,f _i+1 ) represents the i-th group and the i+1th group. The progressive multiple between the side audio frequencies, ΔΦ ^frac (f _i ) represents the measured phase difference value of the propagation phase change value of the ultrasonic wave in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave in the i-th group side audio frequency. [X] _0.5 represents a rounding operation on X and satisfies ΔΦ(f ₁ )=ΔΦ ^frac (f ₁ ). ΔΦ(f ₁ )=128°, ΔΦ ^frac (f ₂ )=−80°, K(f ₂ )=5 According to the above iterative formula, ΔΦ(f ₂ )=640° can be obtained. Optionally, the progressive multiples K(f _i , f _i+1 ) of the adjacent group side audio frequencies may be integers or decimals. The progressive multiples in this embodiment are all analyzed on an integer basis. In theory, integers and decimals do not affect the accuracy of the calculation and the effectiveness of the method.

Step S107, calculating a fluid flow rate according to any set of side audio frequencies and an actual phase difference corresponding to the set of side audio frequencies. Optionally, any set of side audible frequencies of the fluid flow rate is calculated based on any set of side audio frequencies and actual phase difference values corresponding to the set of side audio frequencies. In the ultrasonic flow measurement method using the side sound velocity measurement, as the side audio frequency increases, the phase difference of the forward flow is larger and larger, and the time resolution is finer, and the flow measurement error is smaller. Therefore, in order to seek a higher measurement accuracy, an effective method is to increase the side audio frequency. Therefore, in this embodiment, the actual phase difference corresponding to the largest side audio frequency of each group of side audio frequencies is selected to calculate the fluid flow rate, that is, f is adopted. ₂ =f _max =1MHz, the fluid flow calculation formula is:

Where V represents the flow rate of the fluid, L = 0.2m is the length of the pipe in the flowmeter, R represents the radius of the pipe, C = 1500m / s is the propagation velocity of the ultrasonic wave in the stationary fluid, ΔΦ (f _max ) represents the lateral tone of each group The fluid flow rate is calculated from the actual phase difference corresponding to the largest side audio frequency in the frequency. When f _max = f ₂ =1 MHz, it can be concluded that:

ΔΦ(f _max )=ΔΦ(f ₂ )=640° (10)

According to ΔΦ(f _max )=ΔΦ(f ₂ )=640° and f _max =f ₂ =1MHz, it is not difficult to find the fluid flow rate. In this embodiment, the defuzzification of the forward flow direction is greatly reduced compared with the prior art. The number of side notes reduces the complexity of the system and improves the system response speed. The reduction in side audio frequency reduces the need for measurable phase ΔΦ ^frac , which in turn reduces computational resources and will help reduce system cost.

Referring to FIG. 2, the present invention also provides an ultrasonic flow measuring device based on side sound phase measurement, comprising:

The minimum side audio frequency determining device 1 is configured to obtain, according to the fluid flow rate estimation value, a minimum side audio frequency that the ultrasonic wave propagates the phase change value in the reverse flow direction in the fluid and the phase change value in the downstream direction does not exceed 180°;

a plurality of sets of side tone rate determining means 2 for selecting at least one set of side audio frequencies according to a minimum side audio frequency and a measurement accuracy requirement;

The actual phase difference obtaining means 3 is configured to obtain the measured phase difference value of the ultrasonic wave propagating in the fluid in the countercurrent direction and the phase difference value of the phase change value in the downstream direction according to each set of side audio frequencies The actual phase difference corresponding to the audio rate;

The fluid flow obtaining device 4 is configured to calculate the fluid flow rate according to any set of side audio frequencies and an actual phase difference corresponding to the set of side audio frequencies.

The above-described minimum side audio frequency determining means 1, the plurality of sets of side audio frequency determining means 2, the actual phase difference obtaining means 3, and the fluid flow obtaining means 4 can be operated by the terminal processor. The ultrasonic flow measuring device based on side sound phase measurement according to the present invention obtains the minimum value of the difference between the phase change value of the ultrasonic wave propagating in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave not exceeding 180° according to the fluid flow rate estimation value. Side audio frequency, then select at least one set of side audio frequencies according to the minimum side audio frequency, and finally, according to each set of side audio frequencies, the ultrasonic wave propagates the phase change value in the counterflow direction in the fluid and the measured phase of the phase change value in the downstream direction. Calculating the fluid flow rate according to the actual phase difference corresponding to the set of side audio frequencies and the actual phase difference corresponding to the set of side audio frequencies, and solving the prior art requires multiple sides The number of sounds causes the technical problem of slow response of the flowmeter, improves the response speed of the flowmeter, and reduces the complexity of the system design.

Optionally, the plurality of sets of side tone rate determining means 2 comprise:

The other groups of side audio frequency determining devices, the other groups of side audio frequency determining devices are configured to determine other groups between the first group of side audio frequencies and the maximum group side audio rate according to a progressive multiple between adjacent group side audio frequencies Side audio rate.

Optionally, the progressive multiple between adjacent side audio frequencies in the progressive multiple determining device satisfies:

Optionally, the actual phase difference obtaining means 3 obtains the measured phase difference value of the ultrasonic wave propagating in the fluid in the countercurrent direction and the measured phase difference value in the downstream direction according to the amplitude of each set of side audio frequencies. The calculation formula of the actual phase difference corresponding to the side audio frequency is:

Optionally, any set of side audibility rates in the fluid flow determination device 4 for calculating fluid flow is equal to the maximum group side audibility.

In the specific implementation process, since the transducer used for ultrasonic flow measurement is subject to the 3dB passband, In general, the frequency used to excite the ultrasonic transducer to produce a measured sound wave is not the side tone rate, but the folded sound. Specifically, assuming that the resonant frequency of the ultrasonic transducer is 1 MHz, 400 KHz of the 3 dB bandwidth, the folding sound corresponding to the side tone 200 KHz is 800 KHz or 1.2 KHz. In this case, the measurable phase corresponding to the side tone 200KHz can pass

ΔΦ ^frac (f=200KHz)=ΔΦ ^frac (f=1.2MHz)-ΔΦ ^frac (f=1MHz) (11)

or,

ΔΦ ^frac (f=200KHz)=ΔΦ ^frac (f=1MHz)-ΔΦ ^frac (f=0.8MHz) (12)

The working principle and process of the ultrasonic flow measuring device based on the side sound phase measurement of the present embodiment can refer to the working principle and process of the ultrasonic flow measuring method based on the side sound phase measuring.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

An ultrasonic flow measurement method based on side sound phase measurement, characterized in that it comprises:

Obtaining, according to the fluid flow estimation value, a minimum side audio frequency of the ultrasonic wave propagating the phase change value in the countercurrent direction in the fluid and the phase change value in the downstream direction not exceeding 180°;

Selecting at least one set of side audio frequencies based on the minimum side audio frequency;

Obtaining an actual phase difference corresponding to the set of the side audio frequencies according to a measured phase difference value of the ultrasonic wave propagating the phase change value in the countercurrent direction and the phase change value propagating in the downstream direction according to each set of the side audio frequency value;

The fluid flow rate is calculated based on the set of side tone frequencies of any of the sets and the actual phase difference corresponding to the set of side tone frequencies.
The method of claim 1 wherein selecting at least one set of sidetone frequencies based on the minimum side tone rate comprises:

Selecting a side audio frequency that does not exceed the minimum side audio frequency as a first group side audio frequency, and setting a maximum set side audio frequency greater than the minimum side audio frequency as a maximum group side audio frequency;

Determining a progressive multiple between the side audio frequencies of the adjacent groups according to the absolute error of the ultrasonic phase measurement;

The other group side audio frequencies between the first group side audio frequency and the maximum group side audio rate are determined according to a progressive multiple between the side audio frequencies of the adjacent groups.
The method of claim 2 wherein the progressive multiple between said side audio frequencies of adjacent groups satisfies:

Where K(f i ,f i+1 ) represents the progressive multiple (i≥1) between the i-th group and the i+1th group side audio frequency, and δ represents the ultrasonic phase measurement absolute error.
The method according to claim 3, wherein the measured phase difference value of the ultrasonic wave propagating in the fluid in the countercurrent direction and the phase difference value in the downstream direction is obtained according to each set of the side audio frequencies. The formula for calculating the actual phase difference corresponding to each set of the sidetone frequencies is:

Where ΔΦ(f i+1 ) represents the actual phase difference value (i≥1) of the i+ 1th group side audio frequency, and K(f i ,f i+1 ) represents the i-th group and the i+1th group. The progressive multiple between the side audio frequencies, ΔΦ frac (f i ) represents the measured phase difference value of the propagation phase change value of the ultrasonic wave in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave in the i-th group side audio frequency. [X] 0.5 represents a rounding operation on X and satisfies ΔΦ(f 1 )=ΔΦ frac (f 1 ).
The method of claim 4 wherein:

Any set of said side audibility rates used to calculate fluid flow in the fluid flow is calculated to be equal to said maximum set side audible rate based on any set of said side tone frequencies and actual phase difference values corresponding to the set of side audible frequencies.
An ultrasonic flow measuring device for measuring side sounds, comprising:

The minimum side tone rate determining device (1) is configured to obtain, according to the fluid flow rate estimation value, a minimum sidetone in which the ultrasonic wave propagates the phase change value in the countercurrent direction in the fluid direction and the phase change value in the downstream direction does not exceed 180° frequency;

a plurality of sets of side tone rate determining means (2) for selecting at least one set of side audio frequencies based on the minimum side audio frequency;

The actual phase difference obtaining device (3) is configured to obtain, according to each set of the side audio frequencies, a phase difference value of the ultrasonic wave propagating in the fluid in the countercurrent direction and a phase difference value in the downstream direction An actual phase difference corresponding to the side audio frequency of the group;

The fluid flow obtaining device (4) is configured to calculate the fluid flow rate according to any set of the sidetone frequencies and an actual phase difference corresponding to the set of sidetone frequencies.
The apparatus according to claim 6, wherein said plurality of sets of sidetone ratio determining means (2) comprises:

a first group and a maximum group side audio frequency determining device, configured to select a side audio frequency that does not exceed the minimum side audio frequency as a first group side audio frequency, and a preset maximum setting that is greater than the minimum side audio frequency The side audio frequency is used as the maximum group side audio frequency;

a progressive multiple determining means for determining a progressive multiple between the side audio frequencies of the adjacent groups according to the ultrasonic phase measurement absolute error;

And another group of side tone rate determining means, configured to determine another group side tone between the first group side audio frequency and the maximum group side audio frequency according to a progressive multiple between the side audio frequencies of the adjacent group frequency.
The apparatus according to claim 7, wherein the progressive multiple between said side audio frequencies of adjacent groups in said progressive multiple determining means satisfies:

Where K(f i ,f i+1 ) represents the progressive multiple (i≥1) between the i-th group and the i+1th group side audio frequency, and δ represents the ultrasonic phase measurement absolute error.
The device of claim 8 wherein:

The actual phase difference obtaining means (3) obtains a measured phase difference value of the ultrasonic wave propagating in the fluid in the countercurrent direction and the phase difference value in the downstream direction according to each set of the side audio frequencies The calculation formula of the actual phase difference corresponding to the side audio frequency of the group is:

Where ΔΦ(f i+1 ) represents the actual phase difference value (i≥1) of the i+ 1th group side audio frequency, and K(f i ,f i+1 ) represents the i-th group and the i+1th group. The progressive multiple between the side audio frequencies, ΔΦ frac (f i ) represents the measured phase difference value of the propagation phase change value of the ultrasonic wave in the countercurrent direction and the phase change value in the downstream direction of the ultrasonic wave in the i-th group side audio frequency. [X] 0.5 represents a rounding operation on X and satisfies ΔΦ(f 1 )=ΔΦ frac (f 1 ).
The device of claim 9 wherein:

Any of the sets of side audio frequencies used to calculate fluid flow in the fluid flow determining device (4) is equal to the maximum set side audio frequency.