JP2004317233A

JP2004317233A - Apparatus for measuring fluid flow, program for measuring fluid flow, and record medium for recording the program

Info

Publication number: JP2004317233A
Application number: JP2003110091A
Authority: JP
Inventors: Yuji Nakabayashi; 裕治中林; Koichi Takemura; 晃一竹村
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 2003-04-15
Filing date: 2003-04-15
Publication date: 2004-11-11
Anticipated expiration: 2023-04-15
Also published as: JP4296824B2

Abstract

<P>PROBLEM TO BE SOLVED: To measure a flow velocity and flow rate having a large flow velocity and flow rate fluctuations with low power consumption. <P>SOLUTION: Since a result measured by a power-saving measuring means 6 is retained by a buffer means 8, and a value retained by the buffer means 8 is integrated according to a measurement result by a highly precise measuring means 7, flow rate can be measured with a small amount of power consumption without decreasing measurement precision even in the case of the measurement of the flow rate having large flow rate variations. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は流体の流速や流量等を計測する流体の流れ計測装置に関するものである。
【０００２】
【従来の技術】
従来この種の流体の流れ計測装置は、例えば家庭用のガス流量計として使用されており、１つの流量計測手段を備え流量を計測している（例えば特許文献１参照）。そして、一度設置すると約１０年間動作し続ける必要があるため、少ない消費電力で計測することが重要であった。
【０００３】
図３は従来の流体の流れ計測装置である。図３において、１は流体が流れる流路、２は流体の流量を計測する計測手段、３は計測手段２の出力する計測結果を保持するバッファ手段、４はバッファ手段３に保持した値を積算する積算手段、５は積算手段４の値を表示する表示手段によって構成され、計測手段３は決められた周期で流量を計測している。
【０００４】
特許文献１に記載された従来の流体の流れ計測装置は、計測した流量の変化量が大きい時には計測周期を短くして計測し、流量変動の小さい時には計測周期を大きくすることによって、計測頻度を小さくしている。これによって、計測精度を維持しつつ、省電力化を実現している。
【０００５】
【特許文献１】
特開２０００−１０５１４２号公報
【０００６】
【発明が解決しようとする課題】
しかしながら前記従来の構成では、流量変動が大きいときには計測頻度が高くなり消費電力が多くなる。また、雑音や振動などによって計測精度が悪い環境では、計測精度を上げるため計測回数を増やすなどして消費電力は多くなるが計測安定度を上げる必要があった。そこで市場の流量変動が大きいあるいは計測精度が悪い環境で、精度よく計測しながら１０年間動作する電源容量を、すべての流体の流れ計測装置に搭載する必要があった。
【０００７】
このため流体の流れ計測装置の容積・重量の増大、価格上昇が避けられず商品価値が低くならざるを得なかった。そこで流量変動が大きい環境、雑音や振動がある環境下であっても少ない電力で正確に流体の流速や流量計測する流体の流れ計測装置が求められていた。
【０００８】
本発明は前記従来の課題を解決するもので、流速や流量変動並びに雑音や振動がある環境下であっても正確に低消費電力で動作する流体の流れ計測装置を提供することを目的とする。
【０００９】
【課題を解決するための手段】
前記従来の課題を解決するために本発明の流体の流れ計測装置は、消費電力の少ない省電力計測手段で計測した結果をバッファに保持する。そしてバッファに保持した値を高精度計測手段による計測の結果に応じて積算する。つまり通常の計測は少ない電力で計測し、流速値及び／または流量値を積算する精度は高精度計測手段で計測した結果の高い精度で積算することにより高精度測定の測定頻度を低くし消費電力を小さくする。これによって、流速，流量変動や雑音の多い環境での計測であっても、少ない消費電力で正確に動作する。
【００１０】
【発明の実施の形態】
請求項１に記載の発明は、少なくとも２つの計測手段を備え、前記計測手段のうち電力消費が少なく流速及び／または流量を計測する省電力計測手段と、前記計測手段のうち計測精度が良く流速及び／または流量を計測する高精度計測手段と、前記高精度計測手段の計測結果から流速及び／または流量を判定する流れ判定手段と、前記省電力計測手段の出力を積算し一時的に保持するバッファ手段と、前記流れ判定手段の出力に応じてバッファ手段の出力を積算する積算手段とを備え、通常時は、精度は低いが消費電力の少ない省電力計測手段で流速及び／または流量を計測し計測結果をバッファ手段に保持し、所定の条件となったときに高精度計測手段で流速及び／または流量計測し、バッファ手段に保持した値を高精度計測手段の計測結果に応じて積算手段が積算し表示手段がその結果を表示する。そのため、通常は消費電流が少なく、積算時に高精度で検定するので、計測精度を落とすことなく低消費電力で流速及び／または流量計測が実現できる。また、ガス機器を使用しガスが流れ始めた場合であっても省電力計測手段で定期的に計測しているので流速，流量変化に遅れることなく正確に流速及び／または流量を計測することができる。
【００１１】
請求項２に記載の発明は、特に請求項１に記載の高精度計測手段の計測結果が所定の流速及び／または流量以下の場合、バッファ手段に保持している値をクリアするものであり、流速，流量変動や雑音等また計測装置のオフセットによって発生した計測誤差を除去することができる。
【００１２】
請求項３に記載の発明は、請求項１または２に記載の発明に、バッファ手段に保持している値が所定の値に達したことを検知するバッファ検知手段を備え、前記バッファ検知手段の出力によって高精度計測手段を動作させるので、バッファ手段に保持している値が積算しなければならない値に達したときに高精度計測手段を動作させるようにバッファ検知手段の検知値を設定することにより、高精度計測手段は定期的に動作する必要がなく動作頻度を少なくすることができるので、消費電力を下げることができる。また、バッファ手段の容量を効率的に使用することができ、バッファ手段による平均化の効果で計測ばらつきが小さくなり精度よい流速及び／または流量計測ができる。
【００１３】
請求項４に記載の発明は、請求項１から３のいずれか１項に記載の発明に、特に省電力計測手段の計測結果に応じて高精度計測手段の動作を制御する計測制御手段を備えたものであり、省電力計測手段の計測結果のばらつきが必要な計測精度に対して大きいときに高精度計測手段を動作させることによって、高精度計測手段の動作頻度が低くなり消費電力を低くすることができる。
【００１４】
請求項５に記載の発明は、計測手段のうち電力消費が少ない省電力計測手段を駆動して流速及び／または流量を計測する省電力計測プログラムと、前記計測手段のうち計測精度が良い高精度計測手段を駆動して流速及び／または流量を計測する高精度計測プログラムと、前記高精度計測プログラムによる計測結果から流速及び／または流量を判定する流れ判定プログラムと、前記省電力計測手段の出力を積算し一時的にバッファ手段で保持するバッファプログラムと、前記流れ判定手段の出力に応じて前記バッファ手段の出力を積算する積算プログラムとを備えることにより、通常時は、精度は低いが消費電力の少ない省電力計測手段で流速及び／または流量を計測し計測結果をバッファ手段に保持し、所定の条件となったときに高精度計測手段で流速及び／または流量計測し、バッファ手段に保持した値を高精度計測手段の計測結果に応じて積算手段が積算し表示手段がその結果を表示する。そのため、通常は消費電流が少なく、積算時に高精度で検定するので、計測精度を落とすことなく低消費電力で流速及び／または流量計測が実現できる。また、ガス機器を使用しガスが流れ始めた場合であっても省電力計測手段で定期的に計測しているので流速，流量変化に遅れることなく正確に流速及び／または流量を計測することができる。
【００１５】
請求項６に記載の発明は、請求項５に記載の流体の流れ計測プログラムを媒体に記録することにより、プログラムの配布やインストール作業が容易にできる。
【００１６】
【実施例】
以下、本発明の実施例について、図１、図２を参照しながら説明する。
【００１７】
図１は、本発明の実施例における流体の流れ計測装置のブロック図であり、図２は本発明の実施例の各部の動作をあらわすフローチャートを示すものである。
【００１８】
同図において、１は流路であり、被計測流体が流れる。６は省電力計測手段であり、たとえば超音波を流体に伝播させその伝播時間から流体の流速を求め、流路断面積と補正係数とを考慮して流量を求めるものであり、超音波の伝播回数を少なくする或いは、送信出力を小さくすることによって電力が少ない方法で流路１の流量を計測し計測結果を出力する。
【００１９】
７は高精度計測手段であり、たとえば超音波を流体に伝播させその伝播時間から流体の流速を求め、流路断面積と補正係数とを考慮して流量を求めるものであり、超音波の伝播回数を多くする或いは、送信出力を大きくすることによって流路１の流速や流量を計測精度の良い方法で計測し計測結果を出力する。８はバッファ手段（流れ判定手段）であり、省電力計測手段６の計測結果を積算・保持する。９は流量判定手段（流体の流れ判定手段）であり、高精度計測手段７の計測結果から流量を判定する。ここでは所定の値を流量なしの判断基準としＱ２とする。
【００２０】
１０は積算手段であり、流量判定手段９の出力に応じてバッファ手段８に保持している値を積算する。５は表示手段であり積算手段９の積算値を表示する。１１はバッファ検知手段であり、バッファ手段８が所定の値となったことを検知し出力する。ここでは所定の値Ｑ１をバッファ手段８の容量の０．９倍の値とする。１２は計測制御手段であり、省電力計測手段６の出力とバッファ検知手段１１の出力を受け、積算手段９と高精度計測手段７を動作させる。
【００２１】
以上のように構成された流体の流れ計測装置について、以下その動作作用を図２のフローチャートに沿って説明する。
【００２２】
まず、省電力計測手段６は定期的に流体の流速，流量を計測しバッファ手段８に出力する（ＳＴＥＰ１）。バッファ手段８は省電力計測手段６から受けた流量値を積算・保持する（ＳＴＥＰ２）。バッファ手段８の値は、計測結果のばらつきにより増減しながら、流路１の流速，流量に応じて増えていく。計測制御手段１２は、省電力計測手段６の計測した流量Ｑ（省電力）が所定の値Ｑ１に対して大きいかどうか、また計測ばらつきσ（省電力）が所定の値σ１に対して小さいかどうか判断する（ＳＴＥＰ３）。
【００２３】
ＳＴＥＰ３が真の場合、バッファ検知手段１１はバッファ手段８の値が所定に達したかどうか判断する（ＳＴＥＰ４）。ＳＴＥＰ４が偽の場合は、ＳＴＥＰ１に戻り前記動作を繰り返す。ＳＴＥＰ４が真の場合は、高精度計測手段７を動作させる（ＳＴＥＰ５）。流量判定手段９は高精度計測手段７で計測した流量Ｑ（高精度）が所定の値Ｑ２に比べ大きいかどうか判断する（ＳＴＥＰ６）。ＳＴＥＰ６が真の場合は流量が流れていると判断し積算手段１０にバッファ手段８が保持している値を積算し（ＳＴＥＰ７）、バッファ手段８に保持している値をクリアする（ＳＴＥＰ８）。
【００２４】
ＳＴＥＰ３が偽の場合は、バッファ手段８の値は真の値であると判断し高精度計測手段７で確認の計測をすることなくＳＴＥＰ７へ移行し、ＳＴＥＰ７と同じ動作をする。ＳＴＥＰ４が真の場合は高精度計測手段１１で確認するまで流量は積算されていないので、再びＳＴＥＰ１に戻る。ＳＴＥＰ６が偽の場合は、流路１には流量が流れてなくバッファ手段８に積算された値は、ばらつきや雑音の影響で発生した流量と判断しバッファ手段８に積算された値をクリアし、ＳＴＥＰ１に戻る。前記流れとは別に表示手段５は積算手段１０の積算値を表示する。
【００２５】
以上のように本実施例において、定期的に省電力計測手段６で流量を計測し計測結果をバッファ手段８に積算・保持する。バッファ手段８が一杯になる直前で高精度計測手段７を動作させる。そして、バッファ手段８に保持した値を高精度計測手段７の計測結果に応じて積算手段１０が積算するので、通常は消費電流が少なく、積算時に高精度で検定するので、計測精度を落とすことなく低消費電力で流量計測が実現できる。また、ガス機器を使用しガスが流れ始めた場合であっても省電力計測手段６で定期的に計測しているので流量変化に遅れることなく正確に流量を計測することができる。
【００２６】
また本実施例において、省電力計測手段６と高精度計測手段７を超音波流量計とし、超音波の伝播回数で消費電力と測定精度を変えているので、消費電流と測定精度の関係を容易に変更することができ、必要な精度にあわせ設定することができるので、最低限の消費電力で流量計を実現できる。
【００２７】
また本実施例では、高精度計測手段７の計測結果がＱ２の以下の場合、バッファ手段８に保持している値を破棄するものであり、流量変動や雑音等また計測装置のオフセットによって発生した計測誤差を除去することができる。
【００２８】
また本実施例では、バッファ手段８に保持している値がバッファの９０％の値に達したことを検知するバッファ検知手段１１を備え、前記バッファ検知手段１１の出力によって高精度計測手段７を動作させるので、高精度計測手段７は定期的に動作する必要がなく動作頻度を少なくすることができ、消費電力を下げることができる。また、バッファ手段８の容量を効率的に使用することができ、バッファ手段８による平均化の効果で計測ばらつきが小さくなり精度よい流量計測ができる。
【００２９】
また本実施例のでは、省電力計測手段６の計測結果のばらつきが大きく、かつ流量が少なく計測精度が必要な時のみ高精度計測手段を動作させるので、高精度計測手段７の動作頻度が低くなり消費電力を低くすることができる。
【００３０】
また、本実施例では流量判定手段９と、バッファ手段８と、積算手段１０計測制御手段１２の全てもしくは一部をコンピュータに実行させるためのプログラムであってもよく、プログラムであるので汎用コンピュータやサーバを用いて本発明の流量判定手９段と、バッファ手段８と、積算手段１０の一部あるいは全てを容易に実現することができる。またフレキシブルディスク，ＣＤ−ＲＯＭ等の記録媒体に記録したり、通信回線を用いてプログラムを配信したりすることでプログラムの配布やインストール作業が容易にできる。
【００３１】
なお本実施例では、省電力計測手段６と高精度計測手段７を超音波流量計とし、超音波の伝播回数で消費電力と測定精度を変えているが、他の方法の流量計と組み合わせてもかまわない。
【００３２】
また本実施例においては、省電力計測手段６，高精度計測手段７は、流路１を流れる流体の流速及び流量を求めているが、流速と流量のどちらか一方だけでもよく、流速のみを求める場合は，バッファ手段８は省電力計測手段６から受けた流速値を積算・保持することにより、流速変動や雑音の多い環境での計測であっても、流体の流れ計測装置は少ない消費電力で正確に動作する。
【００３３】
【発明の効果】
以上のように、本発明によれば、流速，流量変動や雑音の多い環境での計測であっても、少ない消費電力で正確に動作する流体の流れ計測装置を実現できる。
【図面の簡単な説明】
【図１】本発明の実施例１における流体の流れ計測装置のブロック図
【図２】本発明の実施例１における流量計測のフローチャート
【図３】従来の流体の流れ計測装置のブロック図
【符号の説明】
６省電力計測手段
７高精度計測手段
８バッファ手段
９流量判定手段（流体の流れ計測装置）
１０積算手段
１１バッファ検知手段
１２計測制御手段[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fluid flow measuring device that measures a flow velocity, a flow rate, and the like of a fluid.
[0002]
[Prior art]
Conventionally, this type of fluid flow measurement device is used as, for example, a household gas flow meter, and is provided with a single flow measurement unit to measure the flow rate (for example, see Patent Document 1). Then, once installed, it is necessary to continue operating for about 10 years, so it is important to measure with low power consumption.
[0003]
FIG. 3 shows a conventional fluid flow measuring device. In FIG. 3, 1 is a flow path through which a fluid flows, 2 is a measuring means for measuring the flow rate of the fluid, 3 is a buffer means for holding a measurement result output from the measuring means 2, and 4 is an integrated value held in the buffer means 3. The integrating means 5 and 5 are constituted by display means for displaying the value of the integrating means 4, and the measuring means 3 measures the flow rate at a predetermined cycle.
[0004]
The conventional fluid flow measurement device described in Patent Document 1 measures the measurement frequency by shortening the measurement cycle when the amount of change in the measured flow rate is large, and increases the measurement cycle when the variation in the flow rate is small, thereby increasing the measurement frequency. I'm making it smaller. This achieves power saving while maintaining measurement accuracy.
[0005]
[Patent Document 1]
JP 2000-105142 A
[Problems to be solved by the invention]
However, in the above-described conventional configuration, when the flow rate fluctuation is large, the measurement frequency increases, and the power consumption increases. In an environment where measurement accuracy is poor due to noise, vibration, or the like, power consumption is increased by increasing the number of measurements in order to increase measurement accuracy, but it is necessary to increase measurement stability. Therefore, it is necessary to mount a power supply capacity capable of operating for 10 years while measuring accurately in an environment where the flow rate fluctuation in the market is large or the measurement accuracy is poor in all the fluid flow measurement devices.
[0007]
For this reason, an increase in volume and weight and an increase in the price of the fluid flow measuring device cannot be avoided, and the commercial value must be reduced. Therefore, there is a need for a fluid flow measuring device that accurately measures the flow velocity and flow rate of a fluid with a small amount of electric power even in an environment where the flow rate fluctuation is large, or in an environment where there is noise or vibration.
[0008]
An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a fluid flow measuring device that operates accurately and with low power consumption even in an environment having fluctuations in flow velocity and flow rate and noise and vibration. .
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned conventional problems, a fluid flow measuring device of the present invention holds a result measured by a power saving measuring unit with low power consumption in a buffer. Then, the values held in the buffer are integrated according to the result of measurement by the high-precision measuring means. In other words, the normal measurement is performed with a small amount of power, and the accuracy of integrating the flow velocity value and / or the flow rate value is reduced with the high accuracy of the result measured by the high-precision measuring means, thereby reducing the measurement frequency of the high-precision measurement and reducing the power consumption. Smaller. As a result, even when measurement is performed in an environment with a lot of flow velocity, flow rate fluctuation, and noise, accurate operation can be performed with low power consumption.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 includes at least two measuring means, wherein the power saving measuring means which consumes less power and measures the flow rate and / or the flow rate among the measuring means, and the flow rate measuring means which has a better measurement accuracy than the measuring means. And / or a high-precision measuring means for measuring a flow rate, a flow determining means for determining a flow velocity and / or a flow rate from a measurement result of the high-precision measuring means, and an output of the power-saving measuring means integrated and temporarily stored. A buffer means; and an integrating means for integrating the output of the buffer means in accordance with the output of the flow determining means. Normally, the flow rate and / or the flow rate are measured by the power saving measuring means having low accuracy but low power consumption. The measurement result is stored in the buffer means, and when a predetermined condition is satisfied, the flow velocity and / or flow rate is measured by the high precision measurement means, and the value held in the buffer means is measured by the high precision measurement means. Integrating and displaying means accumulating means in response to the display the results. Therefore, the current consumption is usually small, and the verification is performed with high accuracy at the time of integration, so that the flow velocity and / or flow rate can be measured with low power consumption without lowering the measurement accuracy. In addition, even when gas starts to flow using gas equipment, it is measured regularly by the power saving measurement means, so that the flow velocity and / or flow rate can be accurately measured without delay in the change of flow velocity and flow rate. it can.
[0011]
The invention according to claim 2 clears the value held in the buffer means, particularly when the measurement result of the high-precision measuring means according to claim 1 is a predetermined flow rate and / or a flow rate or less, Measurement errors caused by flow velocity, flow fluctuation, noise, etc. and offset of the measuring device can be removed.
[0012]
The invention according to claim 3 is the invention according to claim 1 or 2, further comprising a buffer detection unit that detects that a value held in the buffer unit has reached a predetermined value. Since the high-precision measuring means is operated by the output, the detection value of the buffer detecting means should be set so that the high-precision measuring means is operated when the value held in the buffer means reaches a value that must be integrated. Accordingly, the high-precision measuring means does not need to operate periodically, and the frequency of operation can be reduced, so that power consumption can be reduced. In addition, the capacity of the buffer means can be used efficiently, and the averaging effect of the buffer means reduces measurement dispersion, thereby enabling accurate flow velocity and / or flow rate measurement.
[0013]
According to a fourth aspect of the present invention, there is provided the invention according to any one of the first to third aspects, further comprising a measurement control unit that controls an operation of the high-precision measurement unit in accordance with a measurement result of the power-saving measurement unit. By operating the high-precision measuring means when the dispersion of the measurement results of the power-saving measuring means is large relative to the required measurement accuracy, the operation frequency of the high-precision measuring means is reduced and the power consumption is reduced. be able to.
[0014]
According to a fifth aspect of the present invention, there is provided a power saving measurement program for measuring a flow rate and / or a flow rate by driving a power saving measuring means which consumes less power among the measuring means, and a high precision measuring means having a good measuring accuracy. A high-precision measurement program for measuring the flow velocity and / or flow rate by driving the measurement means, a flow determination program for determining the flow velocity and / or flow rate from the measurement result by the high-precision measurement program, and an output of the power saving measurement means. By providing a buffer program that accumulates and temporarily holds in the buffer means, and an accumulation program that accumulates the output of the buffer means in accordance with the output of the flow determination means, the accuracy is normally low, but the power consumption is low. Measures the flow velocity and / or flow rate with a small amount of power saving measurement means and stores the measurement results in the buffer means, and performs high-precision measurement when predetermined conditions are met Flow rate and / or flow measurement in stage, integrating and displaying means integrating means in accordance with the measurement results of high accuracy measurement means the value held in the buffer means to display the results. Therefore, the current consumption is usually small, and the verification is performed with high accuracy at the time of integration, so that the flow velocity and / or flow rate can be measured with low power consumption without lowering the measurement accuracy. In addition, even when gas starts to flow using gas equipment, it is measured regularly by the power saving measurement means, so that the flow velocity and / or flow rate can be accurately measured without delay in the change of flow velocity and flow rate. it can.
[0015]
According to a sixth aspect of the present invention, distribution and installation of the program can be facilitated by recording the fluid flow measurement program according to the fifth aspect on a medium.
[0016]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0017]
FIG. 1 is a block diagram of a fluid flow measuring device according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the operation of each unit of the embodiment of the present invention.
[0018]
In FIG. 1, reference numeral 1 denotes a flow channel through which a fluid to be measured flows. Numeral 6 denotes a power-saving measuring means, for example, for transmitting ultrasonic waves to a fluid, obtaining the flow velocity of the fluid from the propagation time, and obtaining the flow rate in consideration of the flow path cross-sectional area and the correction coefficient. By reducing the number of times or reducing the transmission output, the flow rate of the flow path 1 is measured by a method of reducing power, and the measurement result is output.
[0019]
Numeral 7 is a high-precision measuring means for transmitting ultrasonic waves to a fluid, obtaining the flow velocity of the fluid from the propagation time, and calculating the flow rate in consideration of the flow path cross-sectional area and the correction coefficient. By increasing the number of times or increasing the transmission output, the flow velocity and flow rate of the flow path 1 are measured by a method with high measurement accuracy, and the measurement result is output. Reference numeral 8 denotes a buffer unit (flow determination unit) that accumulates and holds the measurement result of the power saving measurement unit 6. 9 is a flow rate determining means (fluid flow determining means), which determines the flow rate from the measurement result of the high-precision measuring means 7. Here, a predetermined value is set as Q2 as a criterion for determining that there is no flow rate.
[0020]
Reference numeral 10 denotes an integrating means for integrating the values held in the buffer means 8 according to the output of the flow rate determining means 9. 5 is a display means for displaying the integrated value of the integrating means 9. Reference numeral 11 denotes a buffer detecting unit which detects that the buffer unit 8 has reached a predetermined value and outputs it. Here, the predetermined value Q1 is a value 0.9 times the capacity of the buffer means 8. A measurement control unit 12 receives the output of the power saving measurement unit 6 and the output of the buffer detection unit 11, and operates the integration unit 9 and the high-precision measurement unit 7.
[0021]
The operation of the fluid flow measuring device configured as described above will be described below with reference to the flowchart of FIG.
[0022]
First, the power-saving measuring means 6 periodically measures the flow velocity and flow rate of the fluid and outputs them to the buffer means 8 (STEP 1). The buffer unit 8 integrates and holds the flow rate value received from the power saving measurement unit 6 (STEP 2). The value of the buffer means 8 increases and decreases in accordance with the flow velocity and flow rate of the flow path 1 while increasing and decreasing due to the dispersion of the measurement results. The measurement control unit 12 determines whether the flow rate Q (power saving) measured by the power saving measurement unit 6 is larger than a predetermined value Q1, and whether the measurement variation σ (power saving) is smaller than the predetermined value σ1. It is determined whether or not (STEP 3).
[0023]
If STEP 3 is true, the buffer detecting means 11 determines whether the value of the buffer means 8 has reached a predetermined value (STEP 4). If STEP 4 is false, the process returns to STEP 1 and repeats the above operation. If STEP 4 is true, the high-precision measuring means 7 is operated (STEP 5). The flow rate determining means 9 determines whether the flow rate Q (high accuracy) measured by the high precision measuring means 7 is larger than a predetermined value Q2 (STEP 6). If the result in STEP 6 is true, it is determined that the flow rate is flowing, and the value held in the buffer means 8 is integrated in the integrating means 10 (STEP 7), and the value held in the buffer means 8 is cleared (STEP 8).
[0024]
If the result of STEP 3 is false, the value of the buffer means 8 is determined to be a true value, and the process proceeds to STEP 7 without performing confirmation measurement by the high-accuracy measuring means 7, and performs the same operation as STEP 7. If STEP 4 is true, the flow rate is not integrated until it is confirmed by the high-precision measuring means 11, so the flow returns to STEP 1 again. If step 6 is false, the flow rate does not flow through the flow path 1 and the value integrated in the buffer means 8 is judged to be the flow rate generated due to the influence of variation or noise, and the value integrated in the buffer means 8 is cleared. , And return to STEP1. The display means 5 displays the integrated value of the integrating means 10 separately from the flow.
[0025]
As described above, in the present embodiment, the flow rate is periodically measured by the power saving measurement unit 6, and the measurement result is accumulated and held in the buffer unit 8. Immediately before the buffer means 8 becomes full, the high-precision measuring means 7 is operated. Since the value held in the buffer means 8 is integrated by the integrating means 10 in accordance with the measurement result of the high-precision measuring means 7, the current consumption is normally small. Flow measurement with low power consumption. In addition, even when the gas starts to flow using the gas equipment, the flow rate can be accurately measured without delay in the flow rate change because the power saving measuring means 6 periodically measures the gas.
[0026]
In this embodiment, the power saving measuring means 6 and the high-precision measuring means 7 are ultrasonic flow meters, and the power consumption and the measuring accuracy are changed by the number of times of propagation of the ultrasonic waves. Can be set according to the required accuracy, so that a flow meter can be realized with minimum power consumption.
[0027]
Further, in the present embodiment, when the measurement result of the high-precision measuring means 7 is equal to or less than Q2, the value held in the buffer means 8 is discarded. Measurement errors can be eliminated.
[0028]
Further, in the present embodiment, a buffer detecting means 11 for detecting that the value held in the buffer means 8 has reached a value of 90% of the buffer is provided. Since the high-precision measuring unit 7 is operated, it is not necessary to operate the high-precision measuring unit 7 at regular intervals, the operation frequency can be reduced, and power consumption can be reduced. In addition, the capacity of the buffer means 8 can be used efficiently, and the averaging effect of the buffer means 8 reduces measurement variations, thereby enabling accurate flow rate measurement.
[0029]
In the present embodiment, the high-precision measuring means 7 is operated only when the variation in the measurement results of the power-saving measuring means 6 is large, the flow rate is small, and the measuring precision is required. Power consumption can be reduced.
[0030]
Further, in the present embodiment, a program for causing a computer to execute all or a part of the flow rate determining means 9, the buffer means 8, and the integrating means 10 and the measurement control means 12 may be used. Using a server, a part or all of the flow rate determining means 9 of the present invention, the buffer means 8 and the integrating means 10 can be easily realized. Further, by recording the program on a recording medium such as a flexible disk or a CD-ROM or distributing the program using a communication line, the program can be easily distributed and installed.
[0031]
In this embodiment, the power-saving measuring means 6 and the high-precision measuring means 7 are ultrasonic flow meters, and the power consumption and the measuring accuracy are changed by the number of times of transmission of the ultrasonic waves. It doesn't matter.
[0032]
In this embodiment, the power saving measuring means 6 and the high-precision measuring means 7 determine the flow velocity and the flow rate of the fluid flowing through the flow path 1. However, only one of the flow rate and the flow rate may be used. When obtaining the flow rate, the buffer means 8 integrates and holds the flow velocity value received from the power saving measurement means 6 so that the fluid flow measuring device can reduce the power consumption even in a measurement in an environment with a lot of flow velocity fluctuation and noise. Works exactly with.
[0033]
【The invention's effect】
As described above, according to the present invention, it is possible to realize a fluid flow measuring device that operates accurately with low power consumption even when measuring in an environment with a large flow velocity, flow rate fluctuation, and noise.
[Brief description of the drawings]
FIG. 1 is a block diagram of a fluid flow measuring device according to a first embodiment of the present invention. FIG. 2 is a flowchart of flow rate measurement according to a first embodiment of the present invention. FIG. 3 is a block diagram of a conventional fluid flow measuring device. Description]
6 Power saving measuring means 7 High precision measuring means 8 Buffer means 9 Flow rate determining means (fluid flow measuring device)
10 integration means 11 buffer detection means 12 measurement control means

Claims

Power-saving measuring means for measuring the flow rate and / or flow rate, which comprises at least two measuring means and which consumes less power, and high-precision measuring means for measuring the flow rate and / or flow rate with good measurement accuracy among the measuring means; Measuring means, flow determining means for determining the flow velocity and / or flow rate from the measurement result of the high-precision measuring means, buffer means for integrating and temporarily storing the output of the power saving measuring means, A fluid flow measuring device comprising: an integrating means for integrating the output of the buffer means according to the output.

2. The fluid flow measuring device according to claim 1, wherein the value held in the buffer means is cleared when the measurement result of the high-precision measuring means is equal to or lower than a predetermined flow velocity and / or flow rate.

3. The fluid flow measurement according to claim 1, further comprising a buffer detection unit configured to detect that a value held in the buffer unit has reached a predetermined value, and operating the high-precision measurement unit based on an output of the buffer detection unit. apparatus.

The fluid flow measuring device according to any one of claims 1 to 3, further comprising a measurement control unit that controls an operation of the high-precision measurement unit according to a measurement result of the power saving measurement unit.

A power saving measurement program for measuring a flow rate and / or a flow rate by driving a power saving measurement means that consumes less power among the measurement means; and a flow rate and / or a driving rate for a high precision measurement means having a good measurement accuracy among the measurement means. Alternatively, a high-precision measurement program for measuring a flow rate, a flow determination program for determining a flow velocity and / or a flow rate from a measurement result by the high-precision measurement program, and an output of the power-saving measuring means are integrated and temporarily stored in a buffer means. A flow program for measuring the flow of a fluid, comprising: a buffer program for performing the operation;

A medium on which the fluid flow measurement program according to claim 5 is recorded.