JP2005077197A

JP2005077197A - Apparatus for measuring flow rate

Info

Publication number: JP2005077197A
Application number: JP2003306632A
Authority: JP
Inventors: Yukio Sakaguchi; 幸夫坂口
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-08-29
Filing date: 2003-08-29
Publication date: 2005-03-24

Abstract

<P>PROBLEM TO BE SOLVED: To save a power consumption in an ultrasonic flowmeter while ensuring its measurement precision. <P>SOLUTION: The ultrasonic flowmeter is provided with a period setting means 9 which sets a measurement period of measuring flow rates, a resolution setting means 7 which sets a measurement resolution, and a time slot flow rate memory means 12 which stores the maximum value of the flow rates measured at every one hour. Values are set in the period setting means 9 and the resolution setting means 7, respectively, based on the flow rates stored in the time slot flow rate memory means 12, thereby making the measurement period and the measurement resolution adjustable and enabling the power consumption to be saved. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

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。 The present invention relates to a flow rate measuring apparatus that measures a flow rate of gas or the like using ultrasonic waves.

従来この種の流量計測装置は、図５に示すように、流体管路１の一部に超音波振動子２と３を流れの方向に相対して設け、送信手段４で出力された信号は切替手段１５を介し振動子２より流れ方向に超音波として出力される。この超音波を振動子３で受信し、切替手段１５を介して増幅手段１６で信号増幅され、基準比較手段１７で検出される。検出されると繰り返し手段６によりトリガ手段８を介して再び振動子３から超音波を発生させ、この繰り返しを行ってその時間を計時手段１０により計測し、逆に振動子３から流れに逆らって超音波を発生し、同様に繰り返し時間を計測し、この時間の差から流体の速度を演算し、流量算出手段１１で流量を算出していた（例えば、特許文献１参照）。
特開平４−３２８４２４号公報 Conventionally, as shown in FIG. 5, this type of flow rate measuring apparatus is provided with ultrasonic transducers 2 and 3 in a part of a fluid conduit 1 in the direction of flow, and the signal output by the transmission means 4 is Ultrasonic waves are output from the vibrator 2 in the flow direction via the switching means 15. This ultrasonic wave is received by the vibrator 3, signal amplified by the amplification means 16 via the switching means 15, and detected by the reference comparison means 17. When it is detected, the repeating means 6 again generates ultrasonic waves from the vibrator 3 via the trigger means 8, repeats this, measures the time by the time measuring means 10, and conversely counters the flow from the vibrator 3. Ultrasonic waves were generated, the time was repeated in the same manner, the fluid velocity was calculated from the time difference, and the flow rate was calculated by the flow rate calculation means 11 (see, for example, Patent Document 1).
JP-A-4-328424

しかしながら、前記従来の流量計測装置ではある一定の計測周期、計測分解能で計測を行っていた。従って流体が流れていない場合にも決められたサンプリング周波数、計測分解能で計測を行っていた。このため電力を使用する頻度が高く、電池駆動の場合短期間のうちに電池交換が必要になり消費電力の低減が課題となっていた。 However, the conventional flow rate measurement apparatus performs measurement with a certain measurement cycle and measurement resolution. Therefore, measurement is performed with the sampling frequency and measurement resolution determined even when no fluid is flowing. For this reason, the frequency of using electric power is high, and in the case of battery driving, battery replacement is required within a short period of time, and reduction of power consumption has been an issue.

本発明は、前記従来の課題を解決するもので、消費電流を低減することを目的としている。 The present invention solves the above-described conventional problems and aims to reduce current consumption.

前記従来の課題を解決するために本発明の流量計測装置は、流体管路に設けられた第１振動子と、第１振動子から送信された超音波信号を受信する第２振動子と、振動子間の信号伝搬時間を計測する計測手段と、計測手段の信号に基づいて流量を算出する流量演算手段と、流量演算手段で得られた流量の所定時間毎の最大値を記憶する時間帯流量記憶手段と、振動子間の信号伝搬時間を計測する計測周期を設定する周期設定手段と、計測手段の計測分解能を設定する分解能設定手段と、時間帯流量記憶手段の値に基づいて周期設定手段および分解能設定手段に値を設定する構成としたものである。 In order to solve the conventional problem, a flow rate measuring device of the present invention includes a first vibrator provided in a fluid conduit, a second vibrator for receiving an ultrasonic signal transmitted from the first vibrator, Measuring means for measuring the signal propagation time between the transducers, flow rate calculating means for calculating the flow rate based on the signal of the measuring means, and a time zone for storing the maximum value of the flow rate obtained by the flow rate calculating means for each predetermined time Based on the value of the flow rate storage means, the period setting means for setting the measurement period for measuring the signal propagation time between the transducers, the resolution setting means for setting the measurement resolution of the measurement means, and the time zone flow rate storage means The value is set in the means and the resolution setting means.

上記構成により、時間帯ごとの記憶流量によって計測周期および計測分解能を設定し、計測の動作時間を短くすることができる。 With the above configuration, the measurement period and measurement resolution can be set according to the memory flow rate for each time zone, and the measurement operation time can be shortened.

以上のように本発明によれば、流量値が大きい時には計測周期を短くして正確に測定でき、流量値が小さい時には測定周期を長くして消費電力を低減することができ、また流量値が大きい時には計測分解能を粗くして消費電力を低減することができ、流量値が小さい時には計測分解能を細かくして正確に測定することができる。 As described above, according to the present invention, when the flow rate value is large, the measurement cycle can be shortened for accurate measurement, and when the flow rate value is small, the measurement cycle can be lengthened to reduce power consumption. When the flow rate is large, the power consumption can be reduced by coarsening the measurement resolution, and when the flow rate value is small, the measurement resolution can be made fine and accurate measurement can be performed.

請求項１に記載の発明は、流体管路に設けられた第１振動子と、第１振動子の発振を行う送信回路と、第１振動子から送信された超音波信号を受信する第２振動子と、第２振動子で受信した信号を増幅し基準信号と比較し受信タイミングを検出する受信回路と、振動子間の信号伝搬時間を計測する計時手段と、計時手段の信号に基づいて流量を算出する流量演算手段と、流量演算手段で得られた流量の所定時間毎の最大値を記憶する時間帯流量記憶手段と、第１振動子と第２振動子間の信号伝搬時間を計測する計測周期を設定する周期設定手段と、計時手段の計測分解能を設定する分解能設定手段と、時間帯流量記憶手段の値に基づいて前記周期設定手段の測定周期および前記分解能設定手段の計測分解能に値を設定する構成とすることにより、計測周期および計測分解能が可変となり、計測の動作時間を短くでき、消費電流を低減することができる。 The invention according to claim 1 is a first vibrator provided in the fluid conduit, a transmission circuit that oscillates the first vibrator, and a second that receives the ultrasonic signal transmitted from the first vibrator. Based on an oscillator, a receiving circuit that amplifies a signal received by the second oscillator and compares it with a reference signal to detect a reception timing, a timing unit that measures a signal propagation time between the transducers, and a signal from the timing unit The flow rate calculation means for calculating the flow rate, the time zone flow rate storage means for storing the maximum value of the flow rate obtained by the flow rate calculation means every predetermined time, and the signal propagation time between the first vibrator and the second vibrator are measured. The period setting means for setting the measurement period to be performed, the resolution setting means for setting the measurement resolution of the time measuring means, and the measurement period of the period setting means and the measurement resolution of the resolution setting means based on the value of the time zone flow rate storage means By configuring the value , The measurement cycle and the measurement resolution is variable, can be shortened operation time of the measurement, it is possible to reduce current consumption.

請求項２に記載の発明は、時間帯流量記憶手段の時間帯毎の記憶流量が所定流量より小さい時に周期設定手段に設定する計測周期を長くする構成とすることで、計測の動作時間を短くでき、消費電流を低減することができる。 According to the second aspect of the present invention, the measurement operation time is shortened by adopting a configuration in which the measurement cycle set in the cycle setting unit is increased when the storage flow rate of the time zone flow rate storage unit is smaller than the predetermined flow rate. And current consumption can be reduced.

請求項３に記載の発明は、時間帯流量記憶手段の時間帯毎の記憶流量が増大するにしたがって分解能設定手段に設定する計測分解能を粗くする構成とすることで計測の動作時間を短くでき、消費電流を低減することができる。 The invention according to claim 3 can shorten the measurement operation time by adopting a configuration in which the measurement resolution set in the resolution setting means is increased as the storage flow rate for each time zone of the time zone flow rate storage means increases, Current consumption can be reduced.

請求項４に記載の発明は、時間帯流量記憶手段を所定期間の流量の最大値を記憶する構成とすることで、ガス器具の使用パターンに適した計測周期および計測分解能を設定でき、正確な流量計測ができる。 In the invention according to claim 4, by setting the time zone flow rate storage means to store the maximum value of the flow rate for a predetermined period, it is possible to set a measurement cycle and measurement resolution suitable for the usage pattern of the gas appliance, and to accurately Flow rate can be measured.

請求項５に記載の発明は、時間帯流量記憶手段を所定期間の記憶流量を期間毎に更新する構成とすることで、ガス器具の使用パターンに適した計測周期および計測分解能を設定でき、正確な流量計測ができる。 According to the fifth aspect of the present invention, the time period flow rate storage means is configured to update the memory flow rate for a predetermined period for each period, so that a measurement cycle and a measurement resolution suitable for the usage pattern of the gas appliance can be set. Can measure the flow rate.

以下、本発明の実施例について図面を参照しながら説明する。 Embodiments of the present invention will be described below with reference to the drawings.

（実施例１）
図１は、本発明の第１の実施例を示すブロック図である。図において、流体管路１の途中に超音波を発振する第１振動子２と受信する第２振動子３を流れの方向に配置している。４は第１振動子２への送信回路、５は第２振動子３で受信した信号を増幅し基準信号と比較し受信タイミングを検出する受信回路で送信から受信までの時間をタイマカウンタのような計時手段１０で求める。繰り返し手段６は送信から受信までを予め決められた回数だけ繰り返し行う。計時手段１０による超音波伝搬時間に応じて管路の大きさや流れの状態を考慮して流量演算手段１１で流量値を求め、この流量演算手段１１の値の所定時間毎の最大値を時間帯流量記憶手段１２で記憶する。この時間帯流量記憶手段１２の値によって周期設定手段９に計測周期を設定する。また、この時間帯流量記憶手段１２の値によって分解能設定手段７に計測分解能である送信から受信までの繰り返し回数を設定する。トリガ手段８は周期設定手段９で決められた計測周期に基づいて計測を開始する信号を繰り返し手段に送る。 (Example 1)
FIG. 1 is a block diagram showing a first embodiment of the present invention. In the figure, a first vibrator 2 that oscillates an ultrasonic wave and a second vibrator 3 that receives an ultrasonic wave are arranged in the flow direction in the middle of a fluid pipe line 1. 4 is a transmission circuit to the first vibrator 2, and 5 is a reception circuit that amplifies the signal received by the second vibrator 3 and compares it with a reference signal to detect the reception timing. It is obtained by the appropriate time measuring means 10. The repeating means 6 repeatedly performs transmission to reception a predetermined number of times. The flow rate calculation unit 11 obtains a flow rate value in consideration of the size of the pipeline and the flow state according to the ultrasonic wave propagation time by the time measuring unit 10, and the maximum value of the flow rate calculation unit 11 for each predetermined time is determined as a time zone. Stored in the flow rate storage means 12. The measurement period is set in the period setting means 9 according to the value of the time zone flow rate storage means 12. Further, the number of repetitions from transmission to reception, which is the measurement resolution, is set in the resolution setting means 7 by the value of the time zone flow rate storage means 12. The trigger means 8 sends a signal for starting measurement based on the measurement cycle determined by the period setting means 9 to the repetition means.

次に、その動作について述べる。送信回路４よりバースト信号を送出され第１振動子２で発振された超音波信号は、流れの中を伝搬し第２振動子３で受信され受信回路５で信号処理され、発信から受信までの時間を計時手段１０で測定する。 Next, the operation will be described. The ultrasonic signal transmitted from the transmission circuit 4 and oscillated by the first vibrator 2 is propagated through the flow, received by the second vibrator 3, and subjected to signal processing by the reception circuit 5, from transmission to reception. Time is measured by the time measuring means 10.

静止流体中の音速を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２と３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、超音波が到達する時間ｔは、
ｔ＝Ｌ／（ｃ＋ｖＣＯＳφ）（１）
となり、（１）式より
ｖ＝（Ｌ／ｔ−ｃ）／ＣＯＳφ （２）
となり、Ｌとφが既知ならｔを測定すれば流速ｖが求められる。この流速より流量Ｑは、断面積をＳ、補正係数をＫとすれば、
Ｑ＝ＫＳｖ（３）
となる。 If the velocity of sound in a static fluid is c and the velocity of fluid flow is v, the propagation speed of ultrasonic waves in the forward direction of the flow is (c + v). When the distance between the transducers 2 and 3 is L, and the angle formed by the ultrasonic propagation axis and the central axis of the pipe is φ, the time t when the ultrasonic wave reaches is
t = L / (c + vCOSφ) (1)
From the formula (1), v = (L / tc) / COSφ (2)
If L and φ are known, the flow velocity v can be obtained by measuring t. From this flow velocity, the flow rate Q can be calculated by assuming that the cross-sectional area is S and the correction coefficient is K
Q = KSv (3)
It becomes.

図２は時間帯流量記憶手段の記憶方法を示したフローチャートで、流量演算手段１１の所定時間毎（例えば１時間毎）の流量の最大値を一定の学習期間記憶する手順を示している。まず、学習期間中かどうかをチェック（Ｓ１０１）し、学習期間中であれば、現在記憶している流量値（記憶流量）と今回測定された流調値（今回流量）とを比較（Ｓ１０２）し、次に、今回流量が大きければ、今回流量を記憶流量として記憶する（Ｓ１０３）。以上により、時間帯流量記憶手段は１時間毎の流量の最大値を記憶するとともに、予め定められた計測周期と計測分解能を周期設定手段および分解能設定手段に設定する。学習期間が終了すると、記憶流量に応じた計測周期および計測分解能を周期設定手段および分解能設定手段に設定する。 FIG. 2 is a flowchart showing the storage method of the time zone flow rate storage means, and shows the procedure for storing the maximum value of the flow rate for every predetermined time (for example, every hour) of the flow rate calculation means 11 for a fixed learning period. First, it is checked whether it is during the learning period (S101). If it is during the learning period, the currently stored flow rate value (stored flow rate) is compared with the current measured flow adjustment value (current flow rate) (S102). Then, if the current flow rate is large, the current flow rate is stored as a stored flow rate (S103). As described above, the time zone flow rate storage unit stores the maximum value of the flow rate per hour and sets a predetermined measurement cycle and measurement resolution in the cycle setting unit and the resolution setting unit. When the learning period ends, the measurement cycle and the measurement resolution corresponding to the stored flow rate are set in the cycle setting unit and the resolution setting unit.

例えばガスメーターのように積算値を正確に求める場合には、計測は煩雑に行う必要がある。特に流量が大きい時には計測サンプリング時間を速くして誤差を小さくする必要があるが、流量が比較的小さい場合には計測サンプリングを遅くしてもほとんど誤差にはならない。よって流量演算手段１１に応じて計測間隔を変更することが出来る。図３は流量が時間的に変化した時の計測の状態を示したもので、流量演算手段１１の値が小さい時には周期設定手段９で計測時間の間隔を大きくし、流量演算手段１１の値が大きくなるに伴って計測時間の間隔を小さくする。 For example, when the integrated value is accurately obtained as in a gas meter, the measurement needs to be performed complicatedly. In particular, when the flow rate is large, it is necessary to shorten the measurement sampling time to reduce the error, but when the flow rate is relatively small, even if the measurement sampling is delayed, there is almost no error. Therefore, the measurement interval can be changed according to the flow rate calculation means 11. FIG. 3 shows the state of measurement when the flow rate changes with time. When the value of the flow rate calculation means 11 is small, the interval of the measurement time is increased by the cycle setting means 9 and the value of the flow rate calculation means 11 is changed. As the time increases, the measurement time interval is reduced.

また、流量が比較的小さい時には計測分解能を細かくして誤差を小さくする必要があるが、流量が大きい場合には計測分解能を粗くしてもほとんど誤差にはならない。よって流量演算手段１１に応じて計測分解能を変更することが出来る。通常日々ガス器具を使用する時間帯は各家庭によってほぼ同一であるため、予めこの使用パターンを記憶しておき、この記憶流量によって、計測周期または計測分解能を変えるのである。 Further, when the flow rate is relatively small, it is necessary to make the measurement resolution fine to reduce the error. However, when the flow rate is large, even if the measurement resolution is made coarse, there is almost no error. Therefore, the measurement resolution can be changed according to the flow rate calculation means 11. Usually, the time zone in which the gas appliance is used every day is almost the same in each household, so this usage pattern is stored in advance, and the measurement cycle or measurement resolution is changed according to this stored flow rate.

（実施例２）
図４は本発明の第２の実施例を示すフローチャートで、学習期間中かどうかをチェック（Ｓ２０１）し、学習期間中であれば、流量演算手段１１の所定時間毎の流量の最大値をに学習流量に記憶する（Ｓ２０２、Ｓ２０３）。学習期間が終了すると時間帯流量記憶手段１２の記憶流量を学習流量で更新する（Ｓ２０４）。時間帯流量記憶手段１２の記憶流量を更新すると次の学習期間がスタートし、流量演算手段１１の１時間毎の流量の最大値を一定の学習期間中に学習流量に記憶する。 (Example 2)
FIG. 4 is a flow chart showing a second embodiment of the present invention. It is checked whether or not it is during the learning period (S201), and if it is during the learning period, the maximum value of the flow rate per predetermined time of the flow rate calculation means 11 is set. The learning flow rate is stored (S202, S203). When the learning period ends, the storage flow rate of the time zone flow rate storage means 12 is updated with the learning flow rate (S204). When the storage flow rate of the time zone flow rate storage unit 12 is updated, the next learning period starts, and the maximum value of the flow rate per hour of the flow rate calculation unit 11 is stored in the learning flow rate during a fixed learning period.

ガス給湯器等の流量は季節が夏と冬では異なり、温度により流量が変化する。例えば冬に学習した記憶流量により計測分解能を粗く設定したままであると、夏になれば流量が減るため計測精度が落ちることとなる。季節或いは月単位の一定の学習期間で記憶流量を更新することにより、計測分解能は季節に応じた流量に適した分解能となり計測制度を確保でき、正確な流量計測ができる。 The flow rate of gas water heaters differs between summer and winter, and the flow rate changes depending on the temperature. For example, if the measurement resolution is roughly set according to the stored flow rate learned in winter, the flow rate is reduced in summer and the measurement accuracy is lowered. By updating the stored flow rate during a fixed learning period in season or month, the measurement resolution becomes a resolution suitable for the flow rate according to the season, and a measurement system can be secured, so that accurate flow rate measurement can be performed.

本発明の第１の実施例の流量計測装置の制御ブロック図Control block diagram of the flow rate measuring apparatus of the first embodiment of the present invention 同装置の時間流量記憶手段のフローチャートFlow chart of time flow rate storage means of the same device 同装置の流量の時間的変化を示す特性図Characteristic diagram showing the change over time of the flow rate 本発明の実施例２のフローチャートFlowchart of Embodiment 2 of the present invention 従来の流量計測装置の制御ブロック図Control block diagram of a conventional flow measurement device

符号の説明Explanation of symbols

１流体管路
２第１振動子
３第２振動子
４送信回路
５受信回路
７分解能設定手段
９周期設定手段
１０計時手段
１１流量演算手段
１２時間帯流量記憶手段
１４計測制御手段 DESCRIPTION OF SYMBOLS 1 Fluid pipe line 2 1st vibrator | oscillator 3 2nd vibrator | oscillator 4 Transmitting circuit 5 Receiving circuit 7 Resolution setting means 9 Period setting means 10 Time measuring means 11 Flow rate calculating means 12 Time zone flow memory means 14 Measurement control means

Claims

流体管路に設けられた第１振動子と、前記第１振動子の発振を行う送信回路と、前記第１振動子から送信された超音波信号を受信する第２振動子と、前記第２振動子で受信した信号を増幅し基準信号と比較し受信タイミングを検出する受信回路と、前記第１振動子と第２振動子間の信号伝搬時間を計測する計時手段と、前記計時手段の信号に基づいて流量を算出する流量演算手段と、前記流量演算手段で得られた流量の所定時間毎の最大値を記憶する時間帯流量記憶手段と、前記振動子間の信号伝搬時間を計測する計測周期を設定する周期設定手段と、前記計時手段の計測分解能を設定する分解能設定手段と、前記時間帯流量記憶手段の値に基づいて前記周期設定手段の測定周期および前記分解能設定手段の計測分解能を設定する計測制御手段とを備えた流量計測装置。 A first vibrator provided in a fluid conduit; a transmission circuit that oscillates the first vibrator; a second vibrator that receives an ultrasonic signal transmitted from the first vibrator; and the second vibrator A receiving circuit for amplifying a signal received by the vibrator and comparing it with a reference signal to detect a reception timing; a time measuring means for measuring a signal propagation time between the first vibrator and the second vibrator; and a signal from the time measuring means A flow rate calculation means for calculating a flow rate based on the flow rate, a time zone flow rate storage means for storing a maximum value of the flow rate obtained by the flow rate calculation means for each predetermined time, and a measurement for measuring a signal propagation time between the vibrators A period setting means for setting a period, a resolution setting means for setting the measurement resolution of the time measuring means, and the measurement period of the period setting means and the measurement resolution of the resolution setting means based on the value of the time zone flow rate storage means Measurement control hand to set Flow rate measuring device provided with and.

計測制御手段は、時間帯流量記憶手段の時間帯毎の記憶流量が所定流量より小さい時に前記周期設定手段に設定する計測周期を長くする請求項１記載の流量計測装置。 2. The flow rate measuring device according to claim 1, wherein the measurement control means lengthens the measurement cycle set in the period setting means when the stored flow rate for each time zone of the time zone flow rate storage means is smaller than a predetermined flow rate.

計測制御手段は、時間帯流量記憶手段の時間帯毎の記憶流量が増大するにしたがって分解能設定手段に設定する計測分解能を粗くする請求項１記載の流量計測装置。 2. The flow rate measuring device according to claim 1, wherein the measurement control means coarsens the measurement resolution set in the resolution setting means as the stored flow rate for each time zone of the time zone flow rate storage means increases.

時間帯流量記憶手段は、所定期間の流量の最大値を記憶する請求項１記載の流量計測装置。 The flow rate measuring device according to claim 1, wherein the time zone flow rate storage means stores a maximum value of a flow rate during a predetermined period.

時間帯流量記憶手段は、所定期間の記憶流量を期間毎に更新する請求項１記載の流量計測装置。 The flow rate measuring device according to claim 1, wherein the time zone flow rate storage means updates the stored flow rate for a predetermined period for each period.