JP2013007605A - Ultrasonic flow meter - Google Patents

Ultrasonic flow meter Download PDF

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JP2013007605A
JP2013007605A JP2011139383A JP2011139383A JP2013007605A JP 2013007605 A JP2013007605 A JP 2013007605A JP 2011139383 A JP2011139383 A JP 2011139383A JP 2011139383 A JP2011139383 A JP 2011139383A JP 2013007605 A JP2013007605 A JP 2013007605A
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ultrasonic
flow velocity
wedge
flow
transmission
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Kitaru Ito
来 伊藤
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Yokogawa Electric Corp
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Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic flow meter capable of highly accurately measuring the flow velocity and flow rate of fluid by selecting the arrangement positions of a wedge and a vibrator and appropriately selecting the transmission timing of the ultrasonic flow meter.SOLUTION: An ultrasonic flow meter for measuring the flow velocity and flow rate of fluid including air bubbles flowing in piping includes: two ultrasonic wave transmission/reception means arranged to be opposed and separated at predetermined distance L in the longitudinal direction of the outer periphery of the piping; and a converter 6 for transmitting ultrasonic signals to the ultrasonic wave transmission/reception means and calculating the velocity of the fluid on the basis of signals reflected against the air bubbles. The predetermined distance L is obtained based on the predetermined and measurable maximum flow velocity Vmax. The transmission interval of the ultrasonic signals to the ultrasonic wave transmission/reception means is obtained by an initial setting flow velocity or the measured flow velocity and the arrangement distance of the wedge 2.

Description

本発明は、流体の流速や流量を高精度に測定する超音波流量計に関し、偏流成分(揺らぎ)の影響をキャンセルした超音波流量計に関する。   The present invention relates to an ultrasonic flowmeter that measures the flow velocity and flow rate of a fluid with high accuracy, and relates to an ultrasonic flowmeter that cancels the influence of a drift component (fluctuation).

超音波流計は、配管内の被測定流体中に含まれる気泡やパーティクルが流体と同じ速度で移動すると仮定し、この移動速度から被測定流体の流速分布や流量を測定している。
図3は、被測定流体の流速分布や流量を求める方法の従来例を示すもので、配管1の外周面に音波伝搬性の楔2a、2bを介して傾斜して固定された超音波振動子3a,3bにより、配管1に対して所定の入射角を与え、特定の周波数で超音波パルスを送信することにより、気泡やパーティクルからの反射体で反射したエコー波の周波数がドップラー効果により反射体の移動速度(流体の流速)に応じて変化するので、この変化量から速度分布を求めるものである。
The ultrasonic flowmeter assumes that bubbles and particles contained in the fluid to be measured in the pipe move at the same speed as the fluid, and measures the flow velocity distribution and flow rate of the fluid to be measured from this moving speed.
FIG. 3 shows a conventional example of a method for obtaining a flow velocity distribution and a flow rate of a fluid to be measured, and an ultrasonic transducer fixed to the outer peripheral surface of the pipe 1 by inclining via sound-transmitting wedges 2a and 2b. By giving a predetermined incident angle to the pipe 1 by 3a and 3b and transmitting an ultrasonic pulse at a specific frequency, the frequency of the echo wave reflected by the reflector from bubbles and particles is reflected by the Doppler effect. Therefore, the velocity distribution is obtained from the amount of change.

あるいは、機器の構成は同じとし、超音波パルスの発振時間間隔をΔt毎に送信し、気泡やパーティクルの反射体からの超音波エコー信号から隣り合う2つの超音波エコー信号の相互相関から速度分布を求める方法等もある。   Alternatively, the equipment configuration is the same, the ultrasonic pulse oscillation time interval is transmitted at every Δt, and the velocity distribution is calculated from the cross-correlation of two adjacent ultrasonic echo signals from the ultrasonic echo signal from the reflector of bubbles or particles. There is also a method to find out.

そして、上述のいずれの方法においても配管内の流れの偏流成分(揺らぎ)の影響をキャンセルするために、対向する面に逆向きで楔、振動子を設置し流速を測定し平均を取る方法で流量の測定を行っている。   In any of the above methods, in order to cancel the influence of the drift component (fluctuation) of the flow in the pipe, a wedge and a vibrator are installed in opposite directions on the opposite surface, and the flow velocity is measured and averaged. The flow rate is being measured.

図4(a,b)は配管内の流れの偏流成分(揺らぎ)の影響をキャンセルするための一例を示すもので、図4(a)は配管1の下側から楔2aを介して振動子3aにより発振された超音波で気泡Aを計ったA測線が計る流速をVAとし、配管1の上側から楔2bを介して振動子3bにより発振された超音波で気泡Bを計ったB測線の計る流速をVBとすると、それぞれの流速は流れの方向成分V1と同一平面内の偏流成分(揺らぎ)成分V2を使ってそれぞれ、VA=V1−V2、VB=V1+V2と表され、それぞれの平均を取ることでV=(VA+VB)/2=V1となり、偏流成分(揺らぎ)成分V2がキャンセル可能である。 4A and 4B show an example for canceling the influence of the drift component (fluctuation) of the flow in the pipe. FIG. 4A shows the vibrator from the lower side of the pipe 1 through the wedge 2a. the flow rate a survey line as measured bubble a at ultrasonic wave oscillation measure the V a by 3a, B survey line as measured bubbles B ultrasonically oscillated by the oscillator 3b from the upper side of the pipe 1 through the wedge 2b , V B = V 1 , V B = V 2 , V A = V 1 −V 2 , V B = V 2 , respectively, using the flow direction component V 1 and the drift component (fluctuation) component V 2 in the same plane. it is expressed as 1 + V 2, each V = (V a + V B ) by taking the mean / 2 = V 1, and the drift component (fluctuation) component V 2 can be canceled.

特開2011−95030号公報JP 2011-95030 A 特許第4544247号公報Japanese Patent No. 4544247

ところで、このような構成の超音波流量計においては、気泡やパーティクルからの反射波からの信号を測定して流量を求めており、偏流成分(揺らぎ)の影響をキャンセルするため、対向する面に逆向きで楔、振動子を設置し測定を行っている。
しかし、図4(a,b)に示すように振動子から送信される超音波のタイミングが異なるため、流速を測定している気泡群が異なっている。そのため、異なる気泡群のもつ偏流成分も異なるため、流れの影響を確実にキャンセルすることができず誤差の原因のひとつとなっている。
By the way, in the ultrasonic flowmeter having such a configuration, a flow rate is obtained by measuring a signal from a reflected wave from a bubble or particle, and in order to cancel the influence of a drift component (fluctuation) Measurement is performed by installing wedges and vibrators in the opposite direction.
However, as shown in FIGS. 4A and 4B, since the timing of the ultrasonic waves transmitted from the vibrator is different, the group of bubbles measuring the flow velocity is different. For this reason, the drift components of the different bubble groups are also different, so that the influence of the flow cannot be canceled reliably, which is one of the causes of errors.

従来は同じ気泡群からの反射信号を測定できないため、A側線で測定できる流速VA=V1−V2、B側線で測定できる流速VBはVB=V1+V2´となる。
そのため、流速成分V1と編流成分V2の2つの成分を含んでおり、平均値Vを求めても編流成分は(−V2−V2´)/2で完全にはキャンセルできないと言う課題があった。
Conventionally, since the reflected signal from the same bubble group cannot be measured, the flow velocity V A = V 1 −V 2 that can be measured on the A side line and the flow velocity V B that can be measured on the B side line are V B = V 1 + V 2 ′.
For this reason, the flow velocity component V 1 and the knitting flow component V 2 are included, and even if the average value V is obtained, the knitting flow component cannot be completely canceled at (−V 2 −V 2 ′) / 2. There was a problem to say.

本測定では楔、振動子の設置位置を選択し、また、超音波流計の送信タイミングを適切に選択することで、同じ気泡群からの反射信号を使うことにより編流成分は同じとみなせることができ、A側線、B側線の平均値を取ってキャンセルすることにより、流体の流速や流量を高精度に測定可能とした超音波流計を提供することを目的としている。   In this measurement, the knitting flow component can be regarded as the same by using the reflected signal from the same bubble group by selecting the installation position of the wedge and transducer, and appropriately selecting the transmission timing of the ultrasonic flowmeter It is possible to provide an ultrasonic flowmeter that can measure the flow velocity and flow rate of a fluid with high accuracy by taking an average value of the A side line and the B side line and canceling.

本発明は上記課題を解決するためになされたもので、請求項1の超音波流計においては、
配管中を流れる気泡を含む流体の流速及び流量を測定する超音波流計において、
前記配管の外周の長手方向に所定の距離(L)を隔て、かつ対向して配置された2つの超音波送受信手段と、前記超音波送受信手段へ超音波信号を送信し、前記気泡で反射した信号に基づいて前記流体の速度を演算する変換器とを備え、
前記所定の距離(L)は予め定めた測定可能な最大流速(Vmax)により求め、
前記超音波送受信手段への超音波信号の送信間隔は初期設定の流速又は測定した流速と楔の設置距離により求め、前記2つの超音波発信手段がそれぞれ同じ気泡群からの反射信号で流速を測定することを特徴とする。
The present invention has been made to solve the above problems, and in the ultrasonic flowmeter of claim 1,
In an ultrasonic flowmeter that measures the flow velocity and flow rate of fluid containing bubbles flowing in a pipe,
Two ultrasonic transmission / reception means arranged opposite to each other at a predetermined distance (L) in the longitudinal direction of the outer circumference of the pipe, and an ultrasonic signal is transmitted to the ultrasonic transmission / reception means and reflected by the bubbles A transducer for calculating the velocity of the fluid based on the signal,
The predetermined distance (L) is obtained from a predetermined maximum measurable flow velocity (Vmax),
The transmission interval of the ultrasonic signal to the ultrasonic transmission / reception means is obtained from the initial flow velocity or the measured flow velocity and the installation distance of the wedge, and the two ultrasonic transmission devices each measure the flow velocity by the reflected signal from the same bubble group. It is characterized by doing.

請求項2においては、請求項1に記載の超音波流量計において、
前記所定の距離(L)はL=Vmax・Tmax(前記変換器が設定可能な送信間隔の最大値)により求め、前記2つの超音波送受信手段からの送信間隔(t)をt=L/V(測定した流速)により求めることを特徴とする。
In claim 2, in the ultrasonic flowmeter according to claim 1,
The predetermined distance (L) is obtained by L = Vmax · Tmax (the maximum value of the transmission interval that can be set by the converter), and the transmission interval (t) from the two ultrasonic transmission / reception means is set to t = L / V. It is obtained by (measured flow velocity).

以上説明したことから明らかなように本発明によれば、
2つの超音波発信手段がそれぞれ同じ気泡群からの反射信号で流速を測定することで、偏流成分(揺らぎ)の影響を確実にキャンセルすることが可能となる。その結果、超音波流量計の流速や流量を高精度に測定することができる。
As is clear from the above description, according to the present invention,
By measuring the flow velocity with the reflected signals from the same bubble group respectively by the two ultrasonic wave transmitting means, it becomes possible to reliably cancel the influence of the drift component (fluctuation). As a result, the flow velocity and flow rate of the ultrasonic flowmeter can be measured with high accuracy.

本発明の超音波流計の実施形態の一例を示す図である。It is a figure which shows an example of embodiment of the ultrasonic flowmeter of this invention. 本発明の超音波流計の動作を示すフローチャートである。It is a flowchart which shows operation | movement of the ultrasonic flowmeter of this invention. 従来の超音波流計の一例を示す図である。It is a figure which shows an example of the conventional ultrasonic flowmeter. 従来の超音波流計の一例を示す図である。It is a figure which shows an example of the conventional ultrasonic flowmeter.

図1(a)は本発明の超音波流計の実施形態の一例を示す図である。
図1(a)において、超音波信号発振・検出部(以後、検出器)Aを配管の外壁に接するように設置する。検出器Aは、振動子3aと楔2aで構成されている。楔2aは振動子3aを支持し、振動子3aから超音波信号を所定の角度で配管5の外壁から被測定流体に入射させる。
Fig.1 (a) is a figure which shows an example of embodiment of the ultrasonic flowmeter of this invention.
In FIG. 1A, an ultrasonic signal oscillation / detection unit (hereinafter referred to as a detector) A is installed in contact with the outer wall of the pipe. The detector A is composed of a vibrator 3a and a wedge 2a. The wedge 2a supports the vibrator 3a, and causes an ultrasonic signal from the vibrator 3a to enter the fluid to be measured from the outer wall of the pipe 5 at a predetermined angle.

同様の構成の検出器Bを間隔Lを空けて配管5の外壁の対向する外周に逆向きに設置する。6は検出器A、Bに対して超音波信号を発信するための電気信号(パルス)を送出し、気泡で反射した超音波信号受信する変換器である。この変換器は交互に超音波信号を送信し、検出器Aでまず流速を測り、次に検出器Bで流速を測定する。   A detector B having the same configuration is installed on the opposite outer periphery of the outer wall of the pipe 5 with an interval L therebetween. Reference numeral 6 denotes a transducer that transmits an electrical signal (pulse) for transmitting an ultrasonic signal to the detectors A and B and receives an ultrasonic signal reflected by bubbles. This transducer alternately transmits ultrasonic signals, detector A first measures the flow velocity, and detector B then measures the flow velocity.

図2は図1(a)に示す超音波流量計の動作フローチャートである。
ステップに従って説明する。
ステップ1 測定のためのパラメータを入力する。
超音波流量計を構成する変換器6には図示しない設定手段により測定前にあらかじめ流速計算をするために必要なパラメータが設定されて保存される(例えば、楔を取り付ける配管肉厚、配管外径、楔音速C1、入射角θ1など)。ここで、楔音速C1は楔の中を伝播するパルスの音速、入射角θ1は配管への超音波の入射角度である。この入射角度は検出器の形で決定される値で固定値である。なお、入射角度は例えば楔に刻印する場合もある。
FIG. 2 is an operation flowchart of the ultrasonic flowmeter shown in FIG.
This will be explained according to the steps.
Step 1 Enter parameters for measurement.
In the transducer 6 constituting the ultrasonic flow meter, parameters necessary for calculating the flow velocity are set and stored in advance by a setting means (not shown) before measurement (for example, pipe wall thickness, pipe outer diameter to which a wedge is attached) , Wedge sound speed C1, incident angle θ1, etc.). Here, the wedge sound speed C1 is the sound speed of a pulse propagating in the wedge, and the incident angle θ1 is an incident angle of the ultrasonic wave to the pipe. This incident angle is a value determined in the form of a detector and is a fixed value. The incident angle may be stamped on the wedge, for example.

ステップ2 流量測定に必要なデータの演算を行う。
配管内を流れる最大流速Vmaxを入力する。この最大流速は配管内径と予測される流量に応じてオペレータが任意に入力する値である。このVmaxは実際の流量計を使用するにあたって流れると予想される最大の流量であり、オペレータ側で予想できる範囲と流量計で測定できる最大の範囲を超えない値となる。オペレータ側で判断できない場合は仕様の最大流速がVmaxとなる。
Step 2 Calculate data necessary for flow measurement.
Enter the maximum flow velocity Vmax flowing in the pipe. This maximum flow velocity is a value arbitrarily input by the operator in accordance with the pipe inner diameter and the predicted flow rate. This Vmax is the maximum flow rate that is expected to flow when the actual flow meter is used, and is a value that does not exceed the range that can be predicted by the operator and the maximum range that can be measured by the flow meter. If the operator cannot make the determination, the maximum flow velocity of the specification is Vmax.

変換器6が設定可能な送信間隔の最大値をTmax、検出器の設置距離をLとすると、
設置距離L=Vmax・Tmaxで与えられるので、その距離(L)を変換器の表示部に表示する。即ち、交互に超音波を発振するタイミングがわかると速さ×時間=距離なので検出器AとBの設置距離を求めることができる。その距離を変換器6に表示し、表示に従い配管の外周に設置距離Lを隔てて向かい合うように検出器A、B(楔)を設定する。この設定は測定前に1度だけ行う。
ステップ3 パラメータを保存する。
変換器が設定可能な送信間隔を入力する。この送信間隔はのちに測定される流速から演算した値をフィードバックして入力するが、初期値として変換器の持つ仕様のTmaxを入力する。
When the maximum value of the transmission interval that can be set by the converter 6 is Tmax and the installation distance of the detector is L,
Since the installation distance L is given by Vmax · Tmax, the distance (L) is displayed on the display unit of the converter. That is, if the timing of alternately oscillating ultrasonic waves is known, since the speed × time = distance, the installation distance between the detectors A and B can be obtained. The distance is displayed on the converter 6, and the detectors A and B (wedges) are set so as to face each other with an installation distance L on the outer periphery of the pipe according to the display. This setting is done only once before measurement.
Step 3 Save the parameters.
Enter the transmission interval that can be set by the converter. The transmission interval is input by feeding back a value calculated from the flow velocity measured later, and Tmax of the specification of the converter is input as an initial value.

ステップ4 パラメータを読み込む。
ここで、パラメータとは楔を取付ける配管肉厚、外径、材質、音速、測定流体の音速、楔と楔の設置距離、楔の音速、楔の角度(入射角度)などである。楔の角度は固定値で楔の形で決定する。楔は個体であらかじめある角度を持たせている。ここでのパラメータとはステップ1及びステップ3で入力した内容のことである。
ステップ5 超音波信号を生成する。
ステップ6 振動子を振動させて超音波を送信する。
ステップ7 反射波(エコー波)を受信する。
Step 4 Read parameters.
Here, the parameters are the thickness of the pipe to which the wedge is attached, the outer diameter, the material, the speed of sound, the speed of sound of the measurement fluid, the distance between the wedge and the wedge, the speed of sound of the wedge, the angle of the wedge (incident angle), and the like. The wedge angle is fixed and determined by the wedge shape. The wedge is an individual and has a certain angle in advance. The parameters here are the contents input in Step 1 and Step 3.
Step 5 An ultrasonic signal is generated.
Step 6 Transmit the ultrasonic wave by vibrating the vibrator.
Step 7 A reflected wave (echo wave) is received.

ステップ8 流速(VA)を演算する。
検出器Aから超音波を2回、Δt(例えば数μsec)の送信間隔をあけて配管中に送信する。そして、気泡やパーティクルで反射したエコーを受信すると伝搬時間差Δtと移動距離Δxを求めることができる。伝搬する距離xは予めわかっているのでVA=Δx/Δtで求めることができる。
Step 8 Calculate the flow velocity (V A ).
The ultrasonic waves are transmitted from the detector A twice into the pipe with a transmission interval of Δt (for example, several μsec). When an echo reflected by bubbles or particles is received, a propagation time difference Δt and a movement distance Δx can be obtained. Since the propagation distance x is known in advance, it can be obtained by V A = Δx / Δt.

超音波を楔、配管を介して流体内に送信すると、気泡からの反射信号が測定できる。この反射信号から気泡までの伝搬時間tがわかる。楔、配管、流体の音速と楔の長さ、配管の肉厚から気泡までの距離xが特定できる。即ち、気泡までの総伝播時間tは
t=(2楔長さ/C1)+2配管肉厚/cosθ2/C2+2x/C3 となる。
(C2は配管音速、C3は流体の音速)超音波を2回、Δtの送信間隔をあけて送信するので2つの気泡の位置の結果x1とx2を得ることができる。
When ultrasonic waves are transmitted into the fluid via wedges and pipes, the reflected signal from the bubbles can be measured. From this reflected signal, the propagation time t to the bubble is known. The distance x from the wedge to the bubble, the sound velocity of the fluid and the length of the wedge, and the thickness of the pipe to the bubble can be specified. That is, the total propagation time t to the bubble is t = (2 wedge length / C1) +2 pipe wall thickness / cos θ2 / C2 + 2x / C3.
(C2 is the sound velocity of the pipe, C3 is the sound velocity of the fluid) Since the ultrasonic waves are transmitted twice with a transmission interval of Δt, the results x1 and x2 of the positions of the two bubbles can be obtained.

音速と入射角度の間には図1(b)に示すようなスネルの法則、
すなわち、sinθ1/C1=sinθ2/C2=sinθ3/C3 の関係がある。
Between the speed of sound and the incident angle, Snell's law as shown in FIG.
That is, there is a relationship of sin θ1 / C1 = sin θ2 / C2 = sin θ3 / C3.

伝播時間差Δt=(x1−x2)sinθ3/C3となり、伝搬時間差Δtの間に進む気泡の移動距離Δxがわかり超音波の2回の送信時間はΔtの間隔があるので、VA=Δx/Δtを解くと最終的にVA=ΔtCl/2Δtsin(θ1)となり流速を求めることができる。同様の計算をB測線でも行い平均値を流速Vとする。 Propagation time difference Δt = (x1-x2) sinθ3 / C3 , and the air bubbles moving distance [Delta] x is understandable twice the transmission time of the ultrasonic wave going between the propagation time difference Delta] t is the interval Δt, V A = Δx / Δt Is finally obtained, V A = ΔtCl / 2Δtsin (θ1), and the flow velocity can be obtained. The same calculation is performed for the B survey line, and the average value is defined as the flow velocity V.

ステップ9 流量Qを下式により演算する。
Q=ρAV
ここで、ρ:密度、A:配管の断面積、V:ステップ8で測定した流速
Step 9 The flow rate Q is calculated by the following equation.
Q = ρAV
Here, ρ: density, A: cross-sectional area of piping, V: flow velocity measured in step 8

ステップ10 測定結果を変換器の表示手段に表示する。
ステップ11 ステップ8で測定された流速VAが設定されたVmaxと同じ場合はステップ12に進んで測定は終了する。流速VAが設定されたVmaxより小さな場合はステップ13に進む。ここで、測定が終了するとはそのパラメータを使って続けて計測するという意味で、流速が変化しなければパラメータは変更せず、流速が変化した場合はステップ13に進んでパラメータを変更して測定を続行するということを意味している。
Step 10 The measurement result is displayed on the display means of the converter.
Step 11 When the flow velocity V A measured in Step 8 is the same as the set Vmax, the process proceeds to Step 12 and the measurement ends. When the flow velocity V A is smaller than the set Vmax, the process proceeds to step 13. Here, when the measurement is completed, it means that measurement is continuously performed using the parameter. If the flow velocity does not change, the parameter is not changed. If the flow velocity changes, the process proceeds to step 13 where the parameter is changed and measured. Means to continue.

ステップ13 同じ気泡群を続けて測定するために、測定した流速VAから検出器AとBを送信する間隔(送信間隔)tをt=L/VAにより求める。
ステップ14 楔設置距離の読み込みを行う。一度設置した楔の距離Lは不変なのでここでは同じ距離を読み込むこととなる。
Step 13 In order to continuously measure the same bubble group, an interval (transmission interval) t for transmitting the detectors A and B from the measured flow velocity V A is obtained by t = L / V A.
Step 14 Read the wedge installation distance. Since the distance L of the wedge once set does not change, the same distance is read here.

ステップ15 送信間隔tはt=L/VAで与えられるので、t、Vmaxの設定を上書きし、B側の流速VBを算出しステップ3に進んで保存されたパラメータの書き換えを行った後流量演算を行う動作を繰り返す。 Step 15 Since the transmission interval t is given by t = L / V A , after overwriting the settings of t and Vmax, calculating the B-side flow velocity V B and proceeding to Step 3 to rewrite the stored parameters Repeat the flow calculation.

即ち、A側線で測定できる流速VA=V1−V2とB側線で測定できる流速VBはVB=V1+V2となり、流速成分V1と編流成分V2の2つの成分を含んでおり、流速はA側線、B側線の平均値を取るので偏流成分(揺らぎ)をキャンセルすることができる。 That is, the flow velocity V A = V 1 −V 2 that can be measured on the A side line and the flow velocity V B that can be measured on the B side line are V B = V 1 + V 2 , and the two components of the flow velocity component V 1 and the knitting flow component V 2 are included. In addition, since the flow velocity takes an average value of the A side line and the B side line, the drift component (fluctuation) can be canceled.

上述のステップ1〜15によれば、検出器A、Bがそれぞれ同じ気泡群からの反射信号で流速を測定するので、偏流成分(揺らぎ)の影響を確実にキャンセルすることが可能になり、結果として超音波流量計の流速や流量を高精度に測定することが可能となる。   According to the above-described steps 1 to 15, since the detectors A and B each measure the flow velocity with the reflected signal from the same bubble group, it becomes possible to reliably cancel the influence of the drift component (fluctuation). As a result, the flow velocity and flow rate of the ultrasonic flowmeter can be measured with high accuracy.

即ち、検出器Aと検出器Bが超音波信号を送信するにはΔtの間隔だけ時間を空けてある。そのため上流側Aで送信したのち、Δt秒間に進む気泡群の距離Lを空けて下流側検出器Bが設置されているので同じ気泡群を測定できることとなる。   In other words, the detector A and the detector B have a time interval Δt for transmitting the ultrasonic signal. For this reason, after transmitting on the upstream side A, the distance L of the bubble group proceeding for Δt seconds is set apart and the downstream detector B is installed, so that the same bubble group can be measured.

気泡群はほぼ同じ塊で進むことは公知である。検出器AとBは交互に送信しているので検出器Aを送信した後、配管内を流れる被測定体の進む距離がわかっていればその距離Lを離した検出器Bで測定すれば同じ気泡群を測定することができる。   It is well known that bubble groups travel in approximately the same mass. Since the detectors A and B transmit alternately, if the distance traveled by the object to be measured flowing in the pipe is known after transmitting the detector A, it is the same if measurement is performed with the detector B separated from the distance L. Bubble groups can be measured.

なお、以上の説明は、本発明の説明および例示を目的として特定の好適な実施例を示したに過ぎない。
従って本発明は、上記実施例に限定されることなく、その本質から逸脱しない範囲で更に多くの変更、変形を含むものである。
The above description merely shows a specific preferred embodiment for the purpose of explanation and illustration of the present invention.
Therefore, the present invention is not limited to the above-described embodiments, and includes many changes and modifications without departing from the essence thereof.

1 配管
2 楔
3 振動子
6 変換器
1 Piping 2 Wedge 3 Vibrator 6 Transducer

Claims (2)

配管中を流れる気泡を含む流体の流速及び流量を測定する超音波流計において、
前記配管の外周の長手方向に所定の距離(L)を隔て、かつ対向して配置された2つの超音波送受信手段と、前記超音波送受信手段へ超音波信号を送信し、前記気泡で反射した信号に基づいて前記流体の速度を演算する変換器とを備え、
前記所定の距離(L)は予め定めた測定可能な最大流速(Vmax)により求め、
前記超音波送受信手段への超音波信号の送信間隔は初期設定の流速又は測定した流速と楔の設置距離により求めることを特徴とする超音波流量計。
In an ultrasonic flowmeter that measures the flow velocity and flow rate of fluid containing bubbles flowing in a pipe,
Two ultrasonic transmission / reception means arranged opposite to each other at a predetermined distance (L) in the longitudinal direction of the outer circumference of the pipe, and an ultrasonic signal is transmitted to the ultrasonic transmission / reception means and reflected by the bubbles A transducer for calculating the velocity of the fluid based on the signal,
The predetermined distance (L) is obtained from a predetermined maximum measurable flow velocity (Vmax),
The ultrasonic flowmeter is characterized in that the transmission interval of the ultrasonic signal to the ultrasonic transmission / reception means is obtained from an initial flow velocity or a measured flow velocity and a wedge installation distance.
前記所定の距離(L)はL=Vmax・tmax(前記変換器が設定可能な送信間隔の最大値)により求め、前記2つの超音波送受信手段からの送信間隔(t)をt=L/V(測定した流速)により求めることを特徴とする請求項1に記載の超音波流量計。   The predetermined distance (L) is obtained by L = Vmax · tmax (the maximum value of the transmission interval that can be set by the converter), and the transmission interval (t) from the two ultrasonic transmission / reception means is set to t = L / V. The ultrasonic flowmeter according to claim 1, wherein the ultrasonic flowmeter is obtained by (measured flow velocity).
JP2011139383A 2011-06-23 2011-06-23 Ultrasonic flow meter Withdrawn JP2013007605A (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019164012A (en) * 2018-03-19 2019-09-26 京セラ株式会社 Fluid measuring device, fluid measuring method, and program

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019164012A (en) * 2018-03-19 2019-09-26 京セラ株式会社 Fluid measuring device, fluid measuring method, and program
JP2021107841A (en) * 2018-03-19 2021-07-29 京セラ株式会社 Fluid measuring device, fluid measuring method, and program
JP7011097B2 (en) 2018-03-19 2022-01-26 京セラ株式会社 Fluid measuring device, fluid measuring method, and program

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