JP2964186B2 - Thermal flow meter - Google Patents
Thermal flow meterInfo
- Publication number
- JP2964186B2 JP2964186B2 JP3298137A JP29813791A JP2964186B2 JP 2964186 B2 JP2964186 B2 JP 2964186B2 JP 3298137 A JP3298137 A JP 3298137A JP 29813791 A JP29813791 A JP 29813791A JP 2964186 B2 JP2964186 B2 JP 2964186B2
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- JP
- Japan
- Prior art keywords
- fluid
- flow rate
- heat capacity
- temperature
- circuit
- 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.)
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、流体に生じる温度差を
検出して流体の流量を計測する熱式流量計に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal flow meter for measuring a flow rate of a fluid by detecting a temperature difference generated in the fluid.
【０００２】[0002]
【従来の技術】従来の熱式流量計の一例として、流体を
通す管にヒータを設け、管の、ヒータの上流側及び下流
側にそれぞれ上流側及び下流側温度検出センサを設け、
かつヒータによる流体への加熱量、両温度検出センサの
検出温度差及び流体の物性データに基づいて管を通過す
る流体の流量を求める演算手段を設けたものがある。こ
の熱式流量計は、管内を流れる流体を発熱体により加熱
し、その際に上流側及び下流側温度センサで温度検出を
行ない、流体への加熱量、両温度検出センサの検出温度
差及び流体の物性データに基づいて流体の流量（質量流
量）を計測するようにしている。2. Description of the Related Art As an example of a conventional thermal flow meter, a heater is provided in a pipe through which a fluid passes, and upstream and downstream temperature detection sensors are provided on the upstream and downstream sides of the heater, respectively.
In addition, there is provided an arithmetic unit for calculating the flow rate of the fluid passing through the pipe based on the amount of heating of the fluid by the heater, the difference between the temperatures detected by the two temperature detection sensors, and the physical property data of the fluid. In this thermal type flow meter, a fluid flowing in a pipe is heated by a heating element, and at that time, the temperature is detected by upstream and downstream temperature sensors. The flow rate (mass flow rate) of the fluid is measured based on the physical property data.
【０００３】[0003]
【発明が解決しようとする課題】ところで、熱式流量計
では種々の流体に対して迅速かつ容易に流量計測できる
ことが望まれている。しかしながら、上述した熱式流量
計では、異なる種類の流体の流量を計測する場合には、
流量計測に先立ってあらかじめその流体の物性データに
対応させて各部材及び設定データ等に対して較正を施し
ておき、その後流量計則を行なうことになり、多種類に
わたる流体の流量計則を行なうには流体毎に各部の較正
が必要となり多くの時間がかかってしまい、上述した要
望に応えられていないというのが実状であった。By the way, it is desired that the thermal type flow meter can measure the flow rate of various fluids quickly and easily. However, with the above-described thermal flow meter, when measuring the flow rates of different types of fluids,
Prior to the flow rate measurement, calibration is performed on each member and setting data in advance in correspondence with the physical property data of the fluid, and thereafter the flow rate regulation is performed, and the flow rate regulation of various kinds of fluids is performed. However, it is necessary to calibrate each part for each fluid, and it takes a lot of time, and it has not been possible to meet the above-mentioned demands.
【０００４】なお、異なる種類の流体の流量を計測する
方策として、複数種類の流体の物性データをあらかじめ
メモリに格納しておき、流体の流量計則を行なう場合、
メモリから対応する物性データを読み出すようにするこ
とが考えられるが、この方策の場合は、計測できる流体
はあらかじめ選択しておいた種類のものに限定されるこ
ととなり、前記要望に対して適切には応えられていない
というのが実状であった。As a measure for measuring the flow rates of different types of fluids, when the physical property data of a plurality of types of fluids is stored in a memory in advance and the flow rate of the fluid is measured,
It is conceivable to read out the corresponding physical property data from the memory, but in the case of this measure, the fluid that can be measured is limited to a preselected type, and it is appropriate to meet the demand. In fact, it was not answered.
【０００５】本発明は、上記事情に鑑みてなされたもの
で、流体の種類に応じた適正な流量計測を迅速かつ容易
に達成できる熱式流量計を提供することを目的とする。The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermal flow meter capable of quickly and easily achieving appropriate flow measurement according to the type of fluid.
【０００６】[0006]
【課題を解決するための手段】本発明は、上記目的を達
成するために、流体を通す管に取付けた発熱体と、前記
管の前記発熱体の上流側及び下流側にそれぞれ設けた上
流側及び下流側温度検出手段と、前記発熱体による前記
流体への加熱量、前記両温度検出手段の検出温度差に基
づいて前記管を通過する流体の流量を求める演算手段と
を有した熱式流量計において、前記両温度検出手段のう
ち少なくとも一方に接続し、かつ停止状態において管内
流体に対する積算加熱量及び接続された前記温度検出手
段で得られる温度変化に基づいて前記流体の熱容量を測
定する熱容量測定手段を備えたことを特徴とする。In order to achieve the above object, the present invention provides a heating element mounted on a pipe through which a fluid passes, and an upstream side provided on the upstream and downstream sides of the heating element of the pipe, respectively. And a downstream-side temperature detecting means, and a calculating means for calculating the flow rate of the fluid passing through the pipe based on the amount of heating of the fluid by the heating element and the temperature difference detected by the two temperature detecting means. A heat capacity connected to at least one of the two temperature detecting means, and measuring a heat capacity of the fluid based on an integrated heating amount for the fluid in the pipe and a temperature change obtained by the connected temperature detecting means in a stopped state. It is characterized by having measuring means.
【０００７】[0007]
【作用】このような構成とすれば、熱容量測定手段が、
停止状態における管内流体に対する積算加熱量及び温度
検出手段で得られる温度変化に基づいて流体の熱容量を
得るので、任意の流体の物性データを用いて流量計測す
ることにより、流体を変更することに伴う装置各部に対
する較正を施すことなく、任意の流体の流量を流体の種
類に応じて計測できる。According to this structure, the heat capacity measuring means is
Since the heat capacity of the fluid is obtained based on the integrated heating amount of the fluid in the pipe in the stopped state and the temperature change obtained by the temperature detecting means, the flow rate is measured by using the physical property data of the arbitrary fluid, thereby changing the fluid. It is possible to measure the flow rate of an arbitrary fluid according to the type of fluid without performing calibration on each part of the device.
【０００８】[0008]
【実施例】以下、本発明の一実施例の熱式流量計を図１
ないし図３に基づいて説明する。図において、１は流体
を通す管で、この管１は肉厚の薄いステンレス等の金属
材料またはフッ素樹脂等の樹脂材料で構成されている。
管１の途中にはコイル状のヒータ２が密着した状態で嵌
装されている。ヒータ２には電力供給回路３が接続され
ていてヒータ２に電力を供給してヒータ２を発熱させ、
このヒータ２の発熱により流体を加熱するようになって
いる。この場合、電力供給回路３は常時は後述する流量
演算回路４からの計測制御信号ａに応じて流体を加熱す
る一方、後述する熱容量測定回路５からの変更時制御信
号ｂを入力することにより前記計測制御信号ａによる流
体加熱を中断し、変更時制御信号ｂに応じて流体を加熱
するようになっている。FIG. 1 shows a thermal flow meter according to an embodiment of the present invention.
A description will be given based on FIG. In the figure, reference numeral 1 denotes a pipe through which a fluid passes, and this pipe 1 is made of a thin metal material such as stainless steel or a resin material such as fluororesin.
A coil-shaped heater 2 is fitted in the middle of the tube 1 in a state of being in close contact therewith. A power supply circuit 3 is connected to the heater 2 and supplies power to the heater 2 to cause the heater 2 to generate heat.
The fluid is heated by the heat generated by the heater 2. In this case, the power supply circuit 3 always heats the fluid in accordance with the measurement control signal a from the flow rate calculation circuit 4 described later, while inputting the change control signal b from the heat capacity measurement circuit 5 described later, The fluid heating by the measurement control signal a is interrupted, and the fluid is heated in accordance with the change control signal b.
【０００９】管１の、ヒータ２の上流側部分及び下流側
部分には上流側及び下流側温度センサ６，７がそれぞれ
設けられている。上流側及び下流側温度センサ６，７の
それぞれは、小型のサーミスタ、薄膜の白金測温抵抗体
または白金等の温度係数が大きい金属製の細線等により
構成されており、応答性の優れたものになっている。Upstream and downstream temperature sensors 6 and 7 are provided at the upstream and downstream portions of the heater 1 of the tube 1, respectively. Each of the upstream and downstream temperature sensors 6 and 7 is made of a small thermistor, a thin-film platinum resistance temperature detector, or a thin metal wire having a large temperature coefficient, such as platinum, and has excellent responsiveness. It has become.
【００１０】上流側及び下流側温度センサ６，７及び電
力供給回路３に接続して演算手段８が設けられており、
また下流側温度センサ７に接続して熱容量測定回路５が
設けられている。An arithmetic means 8 is provided connected to the upstream and downstream temperature sensors 6, 7 and the power supply circuit 3.
Further, a heat capacity measuring circuit 5 is provided connected to the downstream temperature sensor 7.
【００１１】演算手段８は、温度差検出回路９と、前記
流量演算回路４と、物性データ変更回路10とから概略構
成されている。The calculating means 8 is generally constituted by a temperature difference detecting circuit 9, the flow rate calculating circuit 4, and a physical property data changing circuit 10.
【００１２】温度差検出回路９は、上流側及び下流側温
度センサ６，７のそれぞれが検出する上流側及び下流側
検出温度Ｔa ，Ｔb を入力して温度差ΔＴ（ΔＴ＝Ｔb
−Ｔa ）を求め、この温度差ΔＴを流量演算回路４に出
力する。[0012] Temperature difference detecting circuit 9, upstream and downstream detection temperature T a respective upstream and downstream temperature sensors 6 and 7 detects, type T b temperature difference [Delta] T ([Delta] T = T b
−T a ), and outputs the temperature difference ΔT to the flow rate calculation circuit 4.
【００１３】流量演算回路４は、基準となる（較正用）
流体Ｓf の比熱ＣP 、流体Ｓf の熱容量Ｃf 等により定
まる、流体Ｓf の物性データとしての係数ｋf 及び温度
差検出回路９からの温度差ΔＴ等に次式（１）の関係が
あることに基づき、この式（１）の演算を行なって質量
流量Ｑを求めるようになっている。 Ｗ＝ｋf ・ＣP ・Ｑ・ΔＴ … … （１） Ｗ：流体に対する加熱量The flow rate calculation circuit 4 serves as a reference (for calibration).
Specific heat C P of the fluid S f, determined by the heat capacity C f, etc. of the fluid S f, the relationship of the following equation (1) to the temperature difference ΔT and the like from the coefficient k f and the temperature difference detecting circuit 9 as property data of the fluid S f Based on the above, there is calculated the mass flow rate Q by performing the calculation of the equation (1). W = k f · C P · Q · ΔT (1) W: Heating amount of fluid
【００１４】物性データ変更回路10は、熱容量測定回路
５から、任意の流体である測定対象流体Ｓa の熱容量Ｃ
a を示すデータを入力することによりその熱容量Ｃa に
応じて次式（２）の演算を行ない、測定対象流体Ｓa の
物性データである係数ｋa を求め、流量演算回路４にお
ける流量算出に用いられる前記係数ｋf に替えてこの測
定対象流体Ｓa の係数ｋa を流量演算回路４に用いさせ
る。 ｋa ＝Ｃa ／Ｃf … … （２） Ｃf ：あらかじめ求められる較正用流体Ｓf の熱容量 （ただし、測定対象流体としてのＣf やＣa は、熱容量
に相当する量である。すなわち、Ｃa ＝ｋ・Ｃ（ｋ：係
数、Ｃ：熱容量）である。）The physical property data changing circuit 10 outputs the heat capacity C of the fluid S a , which is an arbitrary fluid, from the heat capacity measuring circuit 5.
performs the following calculation (2) in accordance with the heat capacity C a by inputting data indicating a, obtains the coefficients k a is the physical property data of the measurement target fluid S a, the flow rate calculation of the flow rate operation circuit 4 instead of the coefficient k f used makes use of a coefficient k a of the measurement object fluid S a flow rate computation circuit 4. k a = C a / C f ... (2) C f : heat capacity of the calibration fluid S f determined in advance (however, C f and C a as the fluid to be measured are amounts corresponding to the heat capacity. , C a = k · C (k: coefficient, C: heat capacity).)
【００１５】熱容量測定回路５は、スイッチ11を接続し
ており、スイッチ11がオン操作されることにより電力供
給回路３に変更時制御信号ｂを出力すると共に、後述す
るようにして測定対象流体Ｓa の熱容量Ｃa の測定処理
を行なって、この測定処理によって得られた熱容量Ｃa
を物性データ変更回路10に出力する。The heat capacity measuring circuit 5 has a switch 11 connected thereto, and when the switch 11 is turned on, outputs a change-time control signal b to the power supply circuit 3 and, as will be described later, a fluid S to be measured. a) to measure the heat capacity C a , and obtain the heat capacity C a obtained by the measurement processing.
Is output to the physical property data change circuit 10.
【００１６】熱容量測定回路５による測定対象流体Ｓa
の熱容量Ｃa の測定処理について説明する。まず、スイ
ッチ11をオン操作して計測時制御信号ａによる電力供給
回路３の作動を停止させ、この状態で管１に測定対象流
体Ｓa を封入して流量ゼロの状態にしておく。次に、加
熱量Ｗ〔 cal／秒〕で測定対象流体Ｓa への加熱を開始
し、時間ｔf 秒後における温度Ｔb ＝Ｔf を測定する。
上記各データに基づいて熱容量測定回路５は次式（３）
の演算を行なって熱容量Ｃa を求める。 Ｃa ＝Ｗ・ｔf ／（Ｔf −Ｔ0 ） … … （３） Ｔ0 ：初期状態における下流側温度検出センサ５の検出
温度The fluid S a to be measured by the heat capacity measuring circuit 5
The measurement processing of the heat capacity C a will be described. First, the operation of the power supply circuit 3 by the time the control signal a measuring switch 11 is turned on to stop, keep the state of zero flow by sealing measurement target fluid S a to the tube 1 in this state. Next, the heating of the fluid S a to be measured is started with the heating amount W [cal / sec], and the temperature T b = T f after the time t f seconds is measured.
Based on the above data, the heat capacity measuring circuit 5 calculates the following equation (3)
Is calculated to find the heat capacity C a . C a = W · t f / (T f −T 0 ) (3) T 0 : temperature detected by the downstream temperature detection sensor 5 in the initial state
【００１７】以上のように構成された熱式流量計では、
管１内を流れる流体をヒータ２により加熱し、その際に
上流側及び下流側温度センサ６，７で温度検出を行な
い、流体への加熱量、両温度検出センサ６，７の検出温
度差及び流体の物性データに基づいて流体の流量（質量
流量）を計測することになるが、その流量計則に先立っ
て比熱ＣP 等が明らかになっている較正用流体f につい
てあらかじめ装置各部の較正を実施すると共に、流量演
算回路４等に対し較正用流体f の固有データを設定して
おく。In the thermal type flow meter configured as described above,
The fluid flowing through the pipe 1 is heated by the heater 2, and at that time, the temperature is detected by the upstream and downstream temperature sensors 6, 7. becomes to measure the fluid flow rate (mass flow rate) on the basis of the property data of the fluid, the calibration of the pre respective units for the calibration fluid f specific heat C P in advance of its flowmeter law is revealed At the same time, specific data of the calibration fluid f is set in the flow rate calculation circuit 4 and the like.
【００１８】そして、測定対象流体Ｓa の流量を測定す
る場合、あらかじめ時間ｔ＝０かつ加熱量Ｗ＝０におい
て下流側温度検出センサ５の検出温度Ｔb ＝Ｔ0 を測定
し（ステップS1，S2）、この段階で、スイッチ11をオン
操作し、時間計測を開始すると共に、ヒータ２を発熱さ
せて測定対象流体Ｓa を加熱量Ｗ〔 cal／秒〕で加熱し
て熱容量測定処理を開始する（ステップS3）。[0018] Then, when measuring the flow rate of the measurement target fluid S a, to measure the detected temperature T b = T 0 of the downstream side temperature detecting sensor 5 in advance the time t = 0 and the heating amount W = 0 (step S1, S2), at this stage, the switch 11 is turned on, and starts a time measurement, starting the heat capacity measurement process by heating the measurement object fluid S a by heating the heater 2 at a heating amount W [cal / sec] (Step S3).
【００１９】下流側温度検出センサ７が検出温度Ｔb を
熱容量測定回路５に出力する（ステップS4）一方、熱容
量測定回路５が、ステップS3からの時間ｔが時間ｔf と
同等になった段階での下流側温度検出センサ７の検出温
度Ｔf を入力する（ステップS5，S6）ことにより、前記
式（３）の演算を行なって熱容量Ｃa を求めて、この熱
容量Ｃa を物性データ変更回路10に出力する（ステップ
S7）。The downstream temperature sensor 7 outputs a detected temperature T b to the heat capacity measurement circuit 5 (step S4) On the other hand, stage heat capacity measuring circuit 5, the time t from the step S3 becomes equal to the time t f inputting a detected temperature T f of the downstream temperature sensor 7 at (step S5, S6) by, seeking heat capacity C a by performing calculation of the equation (3), the physical data change heat capacity C a Output to circuit 10 (step
S7).
【００２０】物性データ変更回路10は、熱容量Ｃa を入
力することにより前記式（２）の演算を行なって係数ｋ
a を求め（ステップS8）、この係数ｋa を流量演算回路
４に出力して流量演算回路４で流量算出に用いられる式
（１）の係数ｋに、この係数ｋa を替えて用いさせ（ス
テップS9）、この処理終了によりスイッチ11をオフ操作
して変更時制御信号ｂによる電力供給回路３の作動を停
止した状態にする。The physical property data changing circuit 10 calculates the coefficient k by inputting the heat capacity C a and performing the operation of the above equation (2).
seeking a (step S8), and the coefficient k of the coefficient k a a is output to the flow rate calculation circuit 4 flow rate calculation circuit 4 used in the flow rate calculated by the equation (1), let used instead of the coefficients k a ( In step S9), upon completion of this process, the switch 11 is turned off, and the operation of the power supply circuit 3 by the change-time control signal b is stopped.
【００２１】以上の処理を終了した段階で、測定対象流
体Ｓa を管１中に流し、管１内を流れる測定対象流体Ｓ
a をヒータ２により加熱し、その際に上流側及び下流側
温度センサ６，７で温度検出を行ない、測定対象流体Ｓ
a への加熱量Ｗ、両温度検出センサ６，７の検出温度差
ΔＴ及びステップS9で変更された係数ｋa に基づいて前
記（１）の演算を行なって測定対象流体Ｓa の流量（質
量流量）Ｑを得る。At the stage where the above processing is completed, the fluid S a to be measured flows into the pipe 1 and the fluid S a flowing through the pipe 1
a is heated by the heater 2, and at that time, the temperature is detected by the upstream and downstream temperature sensors 6 and 7, and the fluid S to be measured is
heating amount W to a, of the measurement object fluid S a and performs the calculation of the based on the modified coefficients ka at the detected temperature difference ΔT and S9 both temperature sensors 6, 7 (1) flow rate (mass flow rate ) Get Q.
【００２２】また、他の種類の流体の流量を計測する場
合には、上述した図３に示す処理をこの新たな測定対象
の流体に対して上述した説明と同様に実施することによ
り新たな測定対象の流体の流量を精度高く計測できる。When measuring the flow rate of another type of fluid, the above-described processing shown in FIG. 3 is performed on the new fluid to be measured in the same manner as described above, thereby obtaining a new measurement. The flow rate of the target fluid can be measured with high accuracy.
【００２３】このように熱容量測定回路５が測定対象流
体Ｓa の熱容量Ｃa を求め、熱容量測定回路５が測定対
象流体Ｓa の熱容量Ｃa に基づいて測定対象流体Ｓa の
係数ｋa を求め、流量演算回路４で用いられる、あらか
じめ設定された所定流体Ｓfの係数ｋf に替えてこの測
定対象流体Ｓa の係数ｋa を用いさせるので、流体を変
更することに伴う装置各部に対する流体毎の較正を施す
ことなく、測定対象流体Ｓa の流量を計測できることに
なる。装置各部に対する較正を施さなくて済むことによ
り、多種類の流体の流量計測を短時間でかつ容易に実施
できることになる。また、メモリに流体の物性データ等
格納しておいて流体の流量を計測するようにした従来の
熱式流量計では、計測できる流体の種類があらかじめメ
モリにデータが格納されたものに限定されるのに比し
て、本発明の熱式流量計では多種類にわたって流体の流
量を計測できることになる。[0023] Thus determined the heat capacity C a heat capacity measuring circuit 5 is measured fluid S a, the coefficient k a measurement target fluid S a on the basis of the heat capacity measurement circuit 5 in the heat capacity C a measurement target fluid S a Since the coefficient k a of the fluid S a to be measured is used instead of the coefficient k f of the predetermined fluid S f used in the flow rate calculation circuit 4, the flow rate of the fluid is changed. without performing a calibration for each fluid, becomes possible to measure the flow rate of the measurement target fluid S a. Since it is not necessary to perform calibration for each part of the apparatus, the flow rate measurement of various kinds of fluids can be easily performed in a short time. Further, in a conventional thermal flow meter in which the physical property data of a fluid is stored in a memory and the flow rate of the fluid is measured, the types of fluid that can be measured are limited to those in which data is stored in the memory in advance. In contrast, the thermal type flow meter according to the present invention can measure the flow rate of the fluid over many types.
【００２４】なお、上述した実施例では熱容量測定回路
５を下流側温度検出センサ７に接続して設けた場合を例
にしたが、本発明は、これに限定されるものではなく、
上流側温度検出センサ６に接続して設けたり、あるいは
例えば平均値を利用するように上流側及び下流側温度検
出センサ６，７に接続して設けて構成してもよい。In the above-described embodiment, the case where the heat capacity measuring circuit 5 is provided so as to be connected to the downstream temperature detecting sensor 7 is taken as an example. However, the present invention is not limited to this.
It may be configured to be connected to the upstream temperature detection sensor 6 or to be connected to the upstream and downstream temperature detection sensors 6 and 7 to use, for example, an average value.
【００２５】[0025]
【発明の効果】本発明は、以上説明したように構成され
た熱式流量計であるから、流体毎の装置各部に対する較
正を施すことなく、測定対象流体の流量の、流体の種類
に応じた計測を図れるので、多種類の流体の流量計測を
短時間でかつ容易に実施できる。また、流体の種類に応
じて流量計測できることにより、多種類にわたって流体
の流量を計測できることになる。Since the present invention is a thermal flow meter constructed as described above, the flow rate of the fluid to be measured can be adjusted according to the type of fluid without performing calibration for each part of the apparatus for each fluid. Since measurement can be performed, the flow rate measurement of various types of fluids can be performed easily in a short time. Further, since the flow rate can be measured in accordance with the type of the fluid, the flow rate of the fluid can be measured in various types.
【図１】本発明の一実施例の熱式流量計を模式的に示す
図である。FIG. 1 is a view schematically showing a thermal flow meter according to one embodiment of the present invention.
【図２】同熱式流量計の回路部分を示すブロック図であ
る。FIG. 2 is a block diagram showing a circuit portion of the thermal type flow meter.
【図３】同熱式流量計の作用を示すフローチャートであ
る。FIG. 3 is a flowchart showing the operation of the thermal type flow meter.
１ 管 ２ ヒータ ４ 流量演算回路 ５ 熱容量測定回路 ６ 上流側温度センサ ７ 下流側温度センサ ８ 演算手段 10 物性データ変更回路 Ｗ 流体に対する加熱量 ΔＴ 検出温度差 Ｓf 所定流体 Ｓa 測定対象流体（任意の流体） ｋf 係数（所定流体の物性データ） ｋa 係数（任意の流体の物性データ） Ｑa 任意の流体熱容量1 tube 2 heater 4 flow rate computation circuit 5 heat capacity measuring circuit 6 upstream temperature sensor 7 downstream temperature sensor 8 arithmetic unit 10 physical data changing circuit W fluid to the heat quantity ΔT detected temperature difference S f predetermined fluid S a measurement target fluid (optionally fluid) property data of k f factor (physical data of a predetermined fluid) k a coefficient (any fluid) Q a any fluid heat capacity
フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) G01F 1/68 G01P 5/12 Continuation of the front page (58) Field surveyed (Int.Cl. 6 , DB name) G01F 1/68 G01P 5/12
Claims (1)
管の前記発熱体の上流側及び下流側にそれぞれ設けた上
流側及び下流側温度検出手段と、前記発熱体による前記
流体への加熱量、前記両温度検出手段の検出温度差に基
づいて前記管を通過する流体の流量を求める演算手段と
を有した熱式流量計において、前記両温度検出手段のう
ち少なくとも一方に接続し、かつ停止状態において管内
流体に対する積算加熱量及び接続された前記温度検出手
段で得られる温度変化に基づいて前記流体の熱容量を測
定する熱容量測定手段を備えたことを特徴とする熱式流
量計。1. A heating element attached to a pipe through which a fluid passes, upstream and downstream temperature detecting means provided on an upstream side and a downstream side of the heating element of the pipe, respectively; Heating amount, in a thermal flow meter having computing means for calculating the flow rate of the fluid passing through the pipe based on the difference between the detected temperatures of the two temperature detecting means, connected to at least one of the two temperature detecting means, A thermal type flow meter further comprising a heat capacity measuring means for measuring a heat capacity of the fluid based on an integrated heating amount of the fluid in the pipe in a stopped state and a temperature change obtained by the connected temperature detecting means.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3298137A JP2964186B2 (en) | 1991-10-18 | 1991-10-18 | Thermal flow meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3298137A JP2964186B2 (en) | 1991-10-18 | 1991-10-18 | Thermal flow meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05107093A JPH05107093A (en) | 1993-04-27 |
| JP2964186B2 true JP2964186B2 (en) | 1999-10-18 |
Family
ID=17855667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3298137A Expired - Fee Related JP2964186B2 (en) | 1991-10-18 | 1991-10-18 | Thermal flow meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2964186B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4050857B2 (en) * | 1999-04-27 | 2008-02-20 | 矢崎総業株式会社 | Fluid discrimination device and flow rate measuring device |
| JP6110073B2 (en) * | 2012-03-29 | 2017-04-05 | 高砂熱学工業株式会社 | Flow rate measuring device and flow rate measuring method |
| AT513674B1 (en) * | 2012-11-28 | 2014-08-15 | Fronius Int Gmbh | Method and device for monitoring the protective gas in a welding process |
| JP6499851B2 (en) * | 2014-12-05 | 2019-04-10 | 新日本空調株式会社 | Flow rate measurement method |
-
1991
- 1991-10-18 JP JP3298137A patent/JP2964186B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05107093A (en) | 1993-04-27 |
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