JP3488003B2 - Flow measurement device - Google Patents
Flow measurement deviceInfo
- Publication number
- JP3488003B2 JP3488003B2 JP00282996A JP282996A JP3488003B2 JP 3488003 B2 JP3488003 B2 JP 3488003B2 JP 00282996 A JP00282996 A JP 00282996A JP 282996 A JP282996 A JP 282996A JP 3488003 B2 JP3488003 B2 JP 3488003B2
- Authority
- JP
- Japan
- Prior art keywords
- flow
- flow rate
- rectangular
- flow path
- transducers
- 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.)
- Expired - Lifetime
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- Measuring Volume Flow (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は、超音波を利用して
ガスなどの流量を計測する流量計測装置に関するもので
ある。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow rate measuring device for measuring the flow rate of gas or the like using ultrasonic waves.
【0002】[0002]
【従来の技術】従来のこの種の流量計測装置は、たとえ
ば特開平4−140214号公報が知られており、図8
に示すように、流路101を形成する管路体102の一
部に超音波振動子103と104を流れの上流と下流
に、超音波が流れを横断するように流れ方向にある角度
を有して設けている。2. Description of the Related Art A conventional flow rate measuring device of this type is known, for example, from Japanese Patent Application Laid-Open No. 4-140214.
As shown in, the ultrasonic transducers 103 and 104 are provided in a part of the duct body 102 forming the flow path 101 at an angle in the flow direction so that the ultrasonic waves traverse the flow upstream and downstream. Is provided.
【0003】このように流路の断面を横断して超音波が
走査するようにし、超音波の伝搬時間の差から演算装置
105で流速を算出すると共にそのときの流体のレイノ
ルズ数から流路内の流速分布を類推し、補正係数を求め
流量を演算していた。In this way, the ultrasonic wave is made to scan across the cross section of the flow path, the flow velocity is calculated by the arithmetic unit 105 from the difference in the propagation time of the ultrasonic wave, and the inside of the flow path is calculated from the Reynolds number of the fluid at that time. The flow rate distribution was calculated by analogy, the correction coefficient was calculated, and the flow rate was calculated.
【0004】[0004]
【発明が解決しようとする課題】しかしながら、上記従
来の流量計測装置では、レイノルズ数の変化に対応して
流量補正係数を変更させなければならないばかりか、流
体の種類や温度などの環境条件あるいは上流の流れの状
態によってレイノルズ数に対する流速分布の関係が変化
し、測定値に誤差を生じていた。また流速分布の影響を
小さくするために2対以上の振動子によって計測するこ
とも考えられるが、複雑なうえ高価になる欠点があり、
簡単な構成で流量を精度よく計測できる構成を得ること
が新たな課題となっていた。However, in the above-mentioned conventional flow rate measuring device, not only the flow rate correction coefficient must be changed in accordance with the change in Reynolds number, but also the environmental condition such as the kind of fluid or temperature or the upstream condition. The relationship of the flow velocity distribution to the Reynolds number changed depending on the flow condition of the, and the measurement value had an error. It is also possible to measure with two or more pairs of transducers in order to reduce the influence of the flow velocity distribution, but it has the drawback of being complicated and expensive.
It has been a new problem to obtain a structure that can measure the flow rate with high accuracy by a simple structure.
【0005】本発明は上記課題を解決するもので、広範
囲の流量を高精度で計測することを目的としている。The present invention is intended to solve the above-mentioned problems and has an object to measure a wide range of flow rates with high accuracy.
【0006】[0006]
【課題を解決するための手段】本発明の流量計測装置に
おいては、流体が流れる断面長方形の矩形流路と、前記
矩形流路の短辺側に配置され、前記矩形流路を横断して
超音波を送信または受信する1対の振動子と、前記振動
子間の信号伝搬時間を計測し、その計測結果に基づいて
前記流体の流量を算出する流量演算手段とを具備し、前
記1対の振動子は、前記流路断面の全域で超音波を送信
あるいは受信するようにそれらの送、受信面の長さを矩
形流路の対向する短辺の長さとほぼ等しく設定したもの
である。In the flow rate measuring device of the present invention, a rectangular channel having a rectangular cross section through which a fluid flows, and a short side of the rectangular channel are disposed so as to traverse the rectangular channel. a pair of transducers that transmit or receive sound waves, the signal propagation time between said transducers is measured, and and a flow rate calculation means for calculating the flow rate of the fluid based on the measurement result, before
The pair of transducers transmits ultrasonic waves over the entire cross section of the flow path.
Alternatively, the lengths of the sending and receiving surfaces are quadrature so that they can be received.
The length is set to be substantially equal to the length of the opposing short sides of the shaped channel .
【0007】この本発明によれば、流路内の速度分布の
影響を小さくでき、また補正係数の変更も小さくなるの
で、広範囲にわたって計測精度が向上する。According to the present invention, the influence of the velocity distribution in the flow path can be reduced and the correction coefficient can be changed little, so that the measurement accuracy is improved over a wide range.
【0008】[0008]
【発明の実施の形態】上記目的を達成するために本発明
の流量計測装置は、以下の構成とした。BEST MODE FOR CARRYING OUT THE INVENTION In order to achieve the above object, a flow rate measuring device of the present invention has the following configuration.
【0009】流体が流れる断面長方形の矩形流路と、前
記矩形流路の短辺側に配置され、前記矩形流路を横断し
て超音波を送信または受信する1対の振動子と、前記振
動子間の信号伝搬時間を計測し、その計測結果に基づい
て前記流体の流量を算出する流量演算手段とを具備し、
前記1対の振動子は、前記流路断面の全域で超音波を送
信あるいは受信するようにそれらの送、受信面の長さを
矩形流路の対向する短辺の長さとほぼ等しく設定したも
のである。 A rectangular channel having a rectangular cross section through which a fluid flows, a pair of transducers arranged on the short side of the rectangular channel and transmitting or receiving ultrasonic waves across the rectangular channel, and the vibration. And a flow rate calculating means for calculating the flow rate of the fluid based on the measurement result of the signal propagation time between the children.
The pair of transducers transmits ultrasonic waves over the entire cross section of the flow path.
The length of their sending and receiving surfaces to receive or receive
The length of the opposite short sides of the rectangular channel is set to be almost equal.
Of.
【0010】上記矩形流路の縦横の比率は0.3以下に
してあり、また、上記1対の振動子は、その送、受信面
の断面が矩形にしてある。 The aspect ratio of the above rectangular flow path should be 0.3 or less.
In addition, the pair of transducers mentioned above are
Has a rectangular cross section.
【0011】さらに、流路に面した断面の全域で送信感
度あるいは受信感度がほぼ一様となるようにしてある。 Further , the transmission feeling is felt over the entire cross section facing the flow path.
The degree of reception or the reception sensitivity is made substantially uniform.
【0012】本発明は上記構成によって、流速分布に影
響されない受信信号により流速を求めて流量を計測する
ものである。According to the present invention, the flow rate is obtained by measuring the flow rate from the received signal which is not influenced by the flow rate distribution.
【0013】[0013]
【実施例】以下、本発明の第1の実施例を図面にもとづ
いて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings.
【0014】図1において、流路1を形成する流路部材
2に超音波を送受信する矩形形状の第1振動子3と第2
振動子4が流れの上流と下流に配置されている。In FIG. 1, a rectangular first vibrator 3 for transmitting and receiving ultrasonic waves to the flow path member 2 forming the flow path 1 and a second
The oscillators 4 are arranged upstream and downstream of the flow.
【0015】第1振動子3と第2振動子4とは流路に対
して斜めに配置されているので、第1振動子3から送信
された超音波は図2に示すような矩形断面流路5を横断
するように伝搬し、第2振動子4に到達し、逆に第2振
動子4から送信された場合には前述と同様に第1振動子
3に到達する。それぞれの超音波の伝搬時間は流路1内
に流れが存在することで変化する。この伝搬時間は計測
回路6によって測定され流量演算手段7で流量値に変換
される。Since the first oscillator 3 and the second oscillator 4 are arranged obliquely with respect to the flow path, the ultrasonic waves transmitted from the first oscillator 3 flow in a rectangular cross section as shown in FIG. It propagates so as to traverse the path 5, reaches the second oscillator 4, and conversely, when transmitted from the second oscillator 4, reaches the first oscillator 3 as described above. The propagation time of each ultrasonic wave changes due to the existence of a flow in the flow path 1. This propagation time is measured by the measuring circuit 6 and converted into a flow rate value by the flow rate calculating means 7.
【0016】次にその動作について述べる。伝搬時間
は、静止流体中の音をc、流体の流れの速さをvとする
と、流れの順方向の超音波の伝搬速度は(c+v)とな
る。振動子3と4の間の距離をL、超音波伝搬軸と管路
の中心軸とがなす角度をφとすると、上流から下流に超
音波が伝搬する時間t1は、
t1=L/(c+vCOSφ) (1)
となり、下流から上流に伝搬する時間は、
t2=L/(c−vCOSφ) (2)
となり、Lとφが既知ならt1とt2を計測回路6で測
定すれば流速vが求められる。Next, the operation will be described. As for the propagation time, when the sound in the stationary fluid is c and the velocity of the fluid flow is v, the propagation velocity of the ultrasonic wave in the forward direction of the flow is (c + v). Assuming that the distance between the transducers 3 and 4 is L and the angle between the ultrasonic wave propagation axis and the central axis of the conduit is φ, the time t1 for the ultrasonic wave to propagate from upstream to downstream is t1 = L / (c + vCOSφ ) (1) and the time to propagate from the downstream to the upstream is t2 = L / (c-vCOSφ) (2), and if L and φ are known, the flow velocity v can be obtained by measuring t1 and t2 with the measurement circuit 6. To be
【0017】この流速より流量Qは、流路の通過面積を
S、補正計数をKとすれば、流量演算回路7で、
Q=KSv (3)
を演算し流量を求める。From the flow velocity, the flow rate Q is obtained by calculating Q = KSv (3) in the flow rate calculation circuit 7 where S is the passage area of the flow path and K is the correction coefficient.
【0018】流路1内の流速は一般に図1に示すように
流速分布があり、その分布はレイノルズ数や上流の流れ
の乱れによって変化する。この流速分布は2次元的に発
生し、図1に示すように矩形断面の長い方の一辺(長
辺)と図3に示すように矩形断面の短い方の一辺(短
辺)にも発生する。この長辺と短辺の比率(アスペクト
比)は好ましくは0.3以下になるように設定すれば流
速分布はさらに安定する。このように流速分布が存在す
る場合には、その伝搬時間は微小部分で受けた速度の変
化を積分したものになる。The flow velocity in the flow path 1 generally has a flow velocity distribution as shown in FIG. 1, and the distribution changes depending on the Reynolds number and the turbulence of the upstream flow. This flow velocity distribution is two-dimensionally generated, and also occurs on one long side (long side) of the rectangular cross section as shown in FIG. 1 and on one short side (short side) of the rectangular cross section as shown in FIG. . If the ratio of the long side to the short side (aspect ratio) is preferably set to 0.3 or less, the flow velocity distribution is further stabilized. When there is such a flow velocity distribution, its propagation time is the integral of the change in velocity received by the minute portion.
【0019】図4は第2の実施例であり、矩形振動子8
の送受信面8’が矩形の形状をしており、その一辺は矩
形の流路の短辺とほぼ同一の長さになって短辺の流路全
体の超音波を受信することができる。FIG. 4 shows a second embodiment, which is a rectangular vibrator 8
The transmission / reception surface 8'has a rectangular shape, and one side thereof has substantially the same length as the short side of the rectangular flow path, so that ultrasonic waves in the entire short side flow path can be received.
【0020】従って図3に示すような短辺の流速分布が
存在しても、そのすべての超音波を積分した形の信号を
受信するので速度分布を平均した結果が得られる。Therefore, even if there is a flow velocity distribution on the short side as shown in FIG. 3, a signal obtained by integrating all the ultrasonic waves is received, and the result of averaging the velocity distributions can be obtained.
【0021】一方図1に示す流路の長辺の流速分布は、
超音波が長辺を横断して操作しているので、第1振動子
3と第2振動子4との間で流速分布が変化しなければ、
すべての分布による伝搬速度の変化を等しく受けたこと
になり、流速分布の影響を解消することができる。した
がって前述の補正係数Kを変更する必要がない。On the other hand, the flow velocity distribution on the long side of the flow path shown in FIG.
Since the ultrasonic wave is operating across the long side, if the flow velocity distribution does not change between the first vibrator 3 and the second vibrator 4,
This means that the changes in the propagation velocity due to all distributions are received equally, and the influence of the flow velocity distribution can be eliminated. Therefore, it is not necessary to change the above-mentioned correction coefficient K.
【0022】矩形振動子8の送受信面8’は圧電素子の
みで形成されており、全面で送受信が可能で、その送受
信感度は図5に示すようにどの部分もほぼ同一の感度を
有する。図6は、圧電素子の周囲をケーシング7で補強
して機械的強度を増したものであるが、その送受信面
9’は矩形流路の短辺と等しい長さにしてある。The transmission / reception surface 8'of the rectangular vibrator 8 is formed of only a piezoelectric element, and transmission / reception can be performed on the entire surface. The transmission / reception sensitivity is almost the same in all parts as shown in FIG. In FIG. 6, the periphery of the piezoelectric element is reinforced by the casing 7 to increase the mechanical strength, but the transmitting / receiving surface 9'has a length equal to the short side of the rectangular flow path.
【0023】図7は第3の実施例で、振動子10は円形
の断面形状をしているが、その一部は遮蔽体11で覆わ
れており送受信面10’は矩形の流路に対応したところ
のみ超音波が送受信できるように構成している。FIG. 7 shows a third embodiment. The vibrator 10 has a circular cross-sectional shape, a part of which is covered with a shield 11 and the transmitting / receiving surface 10 'corresponds to a rectangular flow path. Ultrasonic waves can be transmitted and received only where they are.
【0024】以上のように本実施例によれば、
(1)流体が流れる断面長方形の矩形流路と、前記矩形
流路に対向配置され、前記矩形流路を横断して超音波を
送信または受信する1対の振動子と、前記振動子間の信
号伝搬時間を計測し、その計測結果に基づいて前記流体
の流量を算出する流量演算手段とを具備し、前記振動子
の矩形流路に対する送、受信は、この矩形流路における
対向辺全域にわたって行われるように設定したので、流
路内の速度分布の影響を小さくでき補正係数の変更も小
さく、測定精度も広範囲にわたって高くなる。また温度
の変化や上流側の流れの乱れに対して安定した計測結果
が得られる。As described above, according to the present embodiment, (1) a rectangular channel having a rectangular cross section through which a fluid flows, and a rectangular channel which is arranged so as to face the rectangular channel and which transmits ultrasonic waves across the rectangular channel or A pair of transducers to be received, and a flow rate calculation means for measuring a signal propagation time between the transducers and calculating a flow rate of the fluid based on the measurement result, are provided for the rectangular flow path of the transducers. Since the sending and receiving are set so as to be performed over the entire opposite sides of the rectangular flow path, the influence of the velocity distribution in the flow path can be reduced, the correction coefficient can be changed little, and the measurement accuracy can be increased over a wide range. In addition, stable measurement results can be obtained against changes in temperature and turbulence in the upstream flow.
【0025】(2)1対の振動子の送、受信面を矩形流
路の短辺側長さとほぼ等しく設定したので、流速分布に
影響されない測定結果が得られ、補正係数の変更も必要
がなくなる。(2) Since the sending and receiving surfaces of the pair of transducers are set to be substantially equal to the length of the short side of the rectangular flow path, the measurement result not affected by the flow velocity distribution can be obtained, and the correction coefficient needs to be changed. Disappear.
【0026】(3)矩形流路の縦横の比率が0.3以下
にしたので、流速分布が小さくなってさらに測定精度が
向上する。(3) Since the ratio of the length and width of the rectangular flow path is set to 0.3 or less, the flow velocity distribution is reduced and the measurement accuracy is further improved.
【0027】(4)振動子は、その送受信側の断面が矩
形であるので、流路の形状と一致させることができより
精度が高くなる。(4) Since the cross section of the vibrator on the transmitting and receiving side is rectangular, it can be made to match the shape of the flow path, and the accuracy becomes higher.
【0028】(5)1対の振動子は流路に面した断面の
全域で送信あるいは受信可能にしたので、流路全体の超
音波信号を得ることができ精度が高くなる。(5) Since the pair of transducers can transmit or receive in the entire area of the cross section facing the flow path, an ultrasonic signal of the entire flow path can be obtained and the accuracy is improved.
【0029】(6)1対の振動子は流路に面した断面の
全域で送信感度あるいは受信感度がほぼ一様にしたの
で、平均的な受信信号が得られ精度が向上する。(6) Since the transmission sensitivity or the reception sensitivity of the pair of transducers is substantially uniform over the entire cross section facing the flow path, an average reception signal is obtained and the accuracy is improved.
【0030】(7)1対の振動子の送、受信面を矩形流
路の短辺側長さよりも大きくし、この短辺側長さ以上の
部分を遮蔽体で塞いだので、振動子の形状に制約されず
様々な振動子に対応可能になり、低価格に構成できる。(7) Since the sending and receiving surfaces of the pair of vibrators are made larger than the length of the short side of the rectangular flow path, and the part of the length of the short side or more is closed by the shield, It can be applied to various vibrators without being restricted by its shape and can be constructed at low cost.
【0031】[0031]
【発明の効果】以上のように本発明によれば、流路内の
速度分布の影響を小さくでき補正係数の変更も小さく、
測定精度も広範囲にわたって高くなる。また温度の変化
や上流側の流れの乱れに対して安定した計測結果が得ら
れる。As described above, according to the present invention, the influence of the velocity distribution in the flow path can be reduced, and the change of the correction coefficient can be reduced.
The measurement accuracy is also high over a wide range. In addition, stable measurement results can be obtained against changes in temperature and turbulence in the upstream flow.
【図1】本発明の第1の実施例の流量計測装置の構成図FIG. 1 is a configuration diagram of a flow rate measuring device according to a first embodiment of the present invention.
【図2】同装置の流路構成の側面図FIG. 2 is a side view of the flow channel structure of the device.
【図3】同装置の流路構成の断面図FIG. 3 is a cross-sectional view of the flow path configuration of the device.
【図4】本発明の第2の実施例の流量計測装置の振動子
の斜視図FIG. 4 is a perspective view of a vibrator of a flow rate measuring device according to a second embodiment of the present invention.
【図5】同装置の受信感度を示す特性図FIG. 5 is a characteristic diagram showing reception sensitivity of the device.
【図6】同装置の振動子の実施例を示す斜視図FIG. 6 is a perspective view showing an embodiment of a vibrator of the same device.
【図7】本発明の第3の実施例の流量計測装置の振動子
の斜視図FIG. 7 is a perspective view of a vibrator of a flow rate measuring device according to a third embodiment of the present invention.
【図8】従来の流量計測装置の構成図FIG. 8 is a block diagram of a conventional flow rate measuring device.
1 矩形流路 2 流路部材 3 第1振動子 4 第2振動子 6 計測回路 7 流量演算手段 8 矩形振動子 11 遮蔽体 1 rectangular flow path 2 flow path members 3 First transducer 4 second oscillator 6 measuring circuit 7 Flow rate calculation means 8 Rectangular vibrator 11 Shield
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中林 裕治 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (72)発明者 名和 基之 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 平5−223608(JP,A) 特表 平5−506092(JP,A) 国際公開91/09282(WO,A1) (58)調査した分野(Int.Cl.7,DB名) G01F 1/66 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yuji Nakabayashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Motoyuki Nawa, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Incorporated (56) References JP-A-5-223608 (JP, A) JP-A-5-506092 (JP, A) International Publication 91/09282 (WO, A1) (58) Fields investigated (Int.Cl . 7 , DB name) G01F 1/66
Claims (4)
前記矩形流路の短辺側に配置され、前記矩形流路を横断
して超音波を送信または受信する1対の振動子と、前記
振動子間の信号伝搬時間を計測し、その計測結果に基づ
いて前記流体の流量を算出する流量演算手段とを具備
し、前記1対の振動子は、前記流路断面の全域で超音波
を送信あるいは受信するようにそれらの送、受信面の長
さを矩形流路の対向する短辺の長さとほぼ等しく設定し
た流量計測装置。1. A rectangular channel having a rectangular cross section, in which a fluid flows,
The signal propagation time between a pair of transducers arranged on the short side of the rectangular channel and transmitting or receiving ultrasonic waves across the rectangular channel and the transducers is measured. Flow rate calculating means for calculating the flow rate of the fluid based on the ultrasonic wave in the entire cross section of the flow path.
The length of their sending and receiving surfaces to send or receive
Set the length to be approximately equal to the length of the opposite short sides of the rectangular flow path.
Flow rate measuring device.
る請求項1記載の流量計測装置。2. The flow rate measuring device according to claim 1, wherein the ratio of the length and width of the rectangular flow path is 0.3 or less.
が矩形である請求項1記載の流量計測装置。3. A pair of transducers are cross-sections of their transmitting and receiving surfaces.
The flow measuring device according to claim 1 , wherein is a rectangle .
域で送信感度あるいは受信感度がほぼ一様である請求項
1記載の流量計測装置。4. A pair of transducers comprises an entire cross section facing the flow path.
The flow rate measuring device according to claim 1 , wherein the transmission sensitivity or the reception sensitivity is substantially uniform in the range .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP00282996A JP3488003B2 (en) | 1996-01-11 | 1996-01-11 | Flow measurement device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP00282996A JP3488003B2 (en) | 1996-01-11 | 1996-01-11 | Flow measurement device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH09189589A JPH09189589A (en) | 1997-07-22 |
JP3488003B2 true JP3488003B2 (en) | 2004-01-19 |
Family
ID=11540317
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP00282996A Expired - Lifetime JP3488003B2 (en) | 1996-01-11 | 1996-01-11 | Flow measurement device |
Country Status (1)
Country | Link |
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JP (1) | JP3488003B2 (en) |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH1144561A (en) * | 1997-07-24 | 1999-02-16 | Kaijo Corp | Ultrasonic flow rate and flow velocity meter |
JP2003075218A (en) * | 2001-09-06 | 2003-03-12 | Matsushita Electric Ind Co Ltd | Ultrasonic flowmeter |
JP3948335B2 (en) * | 2002-04-19 | 2007-07-25 | 松下電器産業株式会社 | Ultrasonic flow meter |
JP4561071B2 (en) * | 2003-09-26 | 2010-10-13 | パナソニック株式会社 | Flow measuring device |
JP2012242090A (en) * | 2011-05-16 | 2012-12-10 | Panasonic Corp | Ultrasonic flowmeter |
US9003894B2 (en) * | 2012-04-25 | 2015-04-14 | General Electric Company | Ultrasonic flow measurement system |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4010148A1 (en) * | 1990-03-29 | 1991-10-02 | Siemens Ag | IMPROVEMENT FOR AN ULTRASONIC GAS / LIQUID FLOW METER |
JPH05223608A (en) * | 1992-02-18 | 1993-08-31 | Tokimec Inc | Ultrasonic flowmeter |
-
1996
- 1996-01-11 JP JP00282996A patent/JP3488003B2/en not_active Expired - Lifetime
Also Published As
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JPH09189589A (en) | 1997-07-22 |
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