JP2023165580A - hot wire flowmeter - Google Patents
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- JP2023165580A JP2023165580A JP2022096109A JP2022096109A JP2023165580A JP 2023165580 A JP2023165580 A JP 2023165580A JP 2022096109 A JP2022096109 A JP 2022096109A JP 2022096109 A JP2022096109 A JP 2022096109A JP 2023165580 A JP2023165580 A JP 2023165580A
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- 239000012530 fluid Substances 0.000 claims abstract description 72
- 239000000470 constituent Substances 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 claims description 11
- 239000007788 liquid Substances 0.000 abstract description 12
- 230000020169 heat generation Effects 0.000 abstract 4
- 239000011810 insulating material Substances 0.000 abstract 1
- 238000001514 detection method Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
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- 230000005855 radiation Effects 0.000 description 1
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Abstract
Description
本発明は、被測定流体の流路に、被測定流体に接する放熱面部を備えた発熱手段部を配備し、被測定流体への熱伝達により熱を損失する前期発熱手段部の温度を検出することで、被測定流体の流量を検出する熱線式流量計であって、
被測定流体の温度と発熱手段部自身の温度との温度差から被測定流体の流量を検出することで、被測定流体が、気体、液体を問わず、広い流量域および、被測定流体が高温でも流量を測定できる技術を提供するものである。The present invention provides a heat generating means section equipped with a heat radiation surface section in contact with the measured fluid in the flow path of the measured fluid, and detects the temperature of the former heat generating means section which loses heat by heat transfer to the measured fluid. This is a hot wire flow meter that detects the flow rate of the fluid to be measured.
By detecting the flow rate of the fluid to be measured from the temperature difference between the temperature of the fluid to be measured and the temperature of the heating means itself, the fluid to be measured can be detected in a wide flow range regardless of whether it is gas or liquid, and the fluid to be measured can be at a high temperature. However, it provides technology that can measure flow rates.
従来、測定流体の流量を測定する流量計には、図２に示すような熱線式流量計や、図３のようなカルマン式流量計、また、図４のような羽根車式流量計が知られている。 Conventionally, flowmeters that measure the flow rate of the fluid to be measured include a hot wire flowmeter as shown in Figure 2, a Karman flowmeter as shown in Figure 3, and an impeller flowmeter as shown in Figure 4. It is being
図２に示すような熱線式流量計は、発熱手段のヒーター前後で被測定流体の温度を測定することで、被測定流体の流量を測定することができる。このような熱線式流量計の場合、測定流体は気体が適している。液体の場合は、小流量の範囲が適していて、大流量は測定することが困難である。 The hot wire flowmeter as shown in FIG. 2 can measure the flow rate of the fluid to be measured by measuring the temperature of the fluid before and after the heater of the heat generating means. In the case of such a hot wire flowmeter, gas is suitable as the fluid to be measured. For liquids, a range of small flow rates is suitable; large flow rates are difficult to measure.
図３に示すようなカルマン式流量計は、被測定流体の上流側に渦を発生させる障害物を設置し、その下流側に、カルマン渦による測定流体の振動を測定する渦検出素子で周波数を検知し、流量を測定する。 In the Karman flowmeter shown in Figure 3, an obstacle that generates a vortex is installed upstream of the fluid to be measured, and a vortex detection element that measures the vibration of the fluid to be measured due to the Karman vortex is installed downstream of the obstacle to detect the frequency. Detect and measure flow rate.
図４に示すような羽根車式流量計は、被測定流体の流れに応じて羽根車が回転し、回転数を羽根車先端に組み込まれた磁石と磁気検出素子で検知することで、流量を測定する。 In the impeller type flowmeter shown in Figure 4, the impeller rotates according to the flow of the fluid to be measured, and the flow rate is detected by detecting the rotation speed with a magnet and magnetic detection element built into the tip of the impeller. Measure.
前記のいずれのタイプの流量計であっても、被測定流体が高温（ここでは１００℃以上）の場合、各素子の耐熱に限界があり、高温用の被測定流体の流量測定には適さない。熱線式流量計も、気体の流量計には適するが、液体の場合は発熱手段の容量に限界があり、小流量の測定器に適している。 Regardless of the type of flowmeter mentioned above, if the fluid to be measured is at a high temperature (100°C or higher in this case), each element has a limit to its heat resistance, making it unsuitable for measuring the flow rate of high-temperature fluids. . Hot wire flowmeters are also suitable for gas flowmeters, but in the case of liquids, the capacity of the heating means is limited, making them suitable for measuring small flow rates.
被測定流体の温度と発熱手段部自身の温度との温度差から被測定流体の流量を検出することで、被測定流体が、気体、液体を問わず、広い流量域および、被測定流体が高温でも流量を測定できる技術を提供するものである。 By detecting the flow rate of the fluid to be measured from the temperature difference between the temperature of the fluid to be measured and the temperature of the heating means itself, the fluid to be measured can be detected in a wide flow range regardless of whether it is gas or liquid, and the fluid to be measured can be at a high temperature. However, it provides technology that can measure flow rates.
被測定流体が高温の場合、カルマン式流量計や羽根車式流量計の場合、渦検出素子が耐熱に適している必要がある。 When the fluid to be measured is at a high temperature, the vortex detection element must be suitable for heat resistance in the case of a Karman flowmeter or an impeller flowmeter.
熱式流量計の場合、被測定流体は通常気体の場合が多い。発熱手段部自身の発熱熱量に限度があるので、被測定流体が液体の場合、あまり流量が大きくなると温度差が取れなくなり、流量の測定限界がある。 In the case of thermal flowmeters, the fluid to be measured is usually gas. Since there is a limit to the amount of heat generated by the heating means itself, when the fluid to be measured is a liquid, if the flow rate becomes too large, the temperature difference cannot be taken, and there is a measurement limit for the flow rate.
本発明は、以上のような課題を解決し、高温の被測定流体が液体であっても、流量が測定できる熱線式流量計である。 The present invention is a hot-wire flowmeter that solves the above-mentioned problems and can measure the flow rate even if the high-temperature measured fluid is a liquid.
発熱手段部が、被測定流体の流れの中にあり、発熱手段部で発熱した熱が流量計筐体への熱伝導を防ぐ断熱構造を有しているので、被測定流体が液体であっても、発熱手段部を十分に昇温できる構造を有している。そのため、被測定流体の温度と発熱手段部自身の温度との差から被測定流体の流量を検出することができる。 The heat generating unit is located in the flow of the fluid to be measured and has an insulating structure that prevents the heat generated by the heat generating unit from being conducted to the flowmeter housing, so even if the fluid to be measured is a liquid. It also has a structure that can sufficiently raise the temperature of the heating means. Therefore, the flow rate of the fluid to be measured can be detected from the difference between the temperature of the fluid to be measured and the temperature of the heat generating unit itself.
また、発熱手段部の構成部材が、高温（ここでは１００℃以上）の耐熱性能を持つ部材で構成されているので、被測定流体が高温であっても、流量を測定することが可能である。発熱手段部の構成部材に、半導体素子や、基板部材は含まれていない。 Furthermore, since the constituent members of the heating means are made of materials that are heat resistant to high temperatures (100°C or higher in this case), it is possible to measure the flow rate even if the fluid to be measured is at a high temperature. . The constituent members of the heating means section do not include a semiconductor element or a substrate member.
本発明の熱式流量計は、発熱手段部で発熱した熱が流量計筐体への熱伝導を防ぐ断熱構造を有しているので、被測定流体が液体であっても、発熱手段部を十分に昇温できる構造を有している。そのため、被測定流体の温度と発熱手段部自身の温度との差から被測定流体の流量を検出することができる。その効果を図５に示す。 The thermal flowmeter of the present invention has an insulating structure that prevents the heat generated in the heat generating section from being conducted to the flowmeter housing, so even if the fluid to be measured is a liquid, the heat generating section can be removed. It has a structure that allows for sufficient temperature rise. Therefore, the flow rate of the fluid to be measured can be detected from the difference between the temperature of the fluid to be measured and the temperature of the heat generating unit itself. The effect is shown in FIG.
本発明の熱線式流量計は、たとえ大流量の領域であっても、流路の内径を大きくとることで液体でも十分に流量を検出することができる。 The hot wire flowmeter of the present invention can sufficiently detect the flow rate of liquid even in a large flow rate region by making the inner diameter of the flow path large.
本発明の熱式流量計は、発熱手段部の構成部材が、高温（ここでは１００℃以上）の耐熱性能を持つ部材で構成されているので、被測定流体が高温領域でも流量を正しく測定することができる。 In the thermal flowmeter of the present invention, the constituent members of the heating means are made of members that have heat resistance performance at high temperatures (here, 100°C or higher), so the flow rate can be accurately measured even when the fluid to be measured is in a high temperature range. be able to.
以下、図面に基づき、本発明の各種実施の形態を説明する。
まず、本発明に係る熱線式流量計の原理について説明する。
発熱手段部２の温度は、発熱手段部温度センサー４で測定することができる。発熱手段部が被測定流体とは表面積Ｔで接している。被測定流体は、筐体内部の直径Ｄの流路を流れている。ここで、表面積Ｓから単位時間に伝達される熱量Ｑは、次式で表される。
Ｑ＝αＳ（Ｔｗ－ＴＯ）
ＴＷ：発熱手段部の表面温度
ＴＯ：被測定流体の温度
α：熱伝達率
ここで、熱伝達率αは、被測定流体の流速により変化する。発熱部のＱが一定であれば、被測定流体温度と発熱手段部温度の差ΔＴは
Ｔｗ－ＴＯ＝（Ｑ／Ｓ）・（１／α）
ΔＴ＝（Ｑ／Ｓ）・（１／α）
となり、被測定流体温度と発熱手段部温度の差ΔＴは、熱伝達率αの関数となる。
つまり、ΔＴと被測定流体の流速の関係を求めれば、被測定流体の流速を求めることができる。熱線式流量計はこの原理を応用したものである。Hereinafter, various embodiments of the present invention will be described based on the drawings.
First, the principle of the hot wire flowmeter according to the present invention will be explained.
The temperature of the heat generating means section 2 can be measured by the heat generating means section temperature sensor 4. The heating means is in contact with the fluid to be measured over a surface area T. The fluid to be measured flows through a flow path with a diameter D inside the housing. Here, the amount of heat Q transferred from the surface area S per unit time is expressed by the following equation.
Q=αS(Tw−T O )
T W : Surface temperature of the heating means T O : Temperature of the fluid to be measured α : Heat transfer coefficient Here, the heat transfer coefficient α changes depending on the flow rate of the fluid to be measured. If Q of the heat generating part is constant, the difference ΔT between the fluid temperature to be measured and the temperature of the heat generating means part is Tw-T O = (Q/S)・(1/α)
ΔT=(Q/S)・(1/α)
Therefore, the difference ΔT between the temperature of the fluid to be measured and the temperature of the heat generating means becomes a function of the heat transfer coefficient α.
That is, by determining the relationship between ΔT and the flow velocity of the fluid to be measured, the flow velocity of the fluid to be measured can be determined. Hot wire flowmeters apply this principle.
第一の実施形態に係る熱線式流量計は、図１に示すように、被測定流体の流路内に流体温度センサー３と発熱手段部２を具備している。As shown in FIG. 1, the hot wire flowmeter according to the first embodiment includes a fluid temperature sensor 3 and a heat generating unit 2 in a flow path of a fluid to be measured.
筐体１は、筐体流路入口１ａと筐体流路出口１ｂの配管接続口形状を具備し、被測定流体を測定する部分の配管と接続することができる。The housing 1 has a pipe connection port shape of a housing flow path inlet 1a and a housing flow path outlet 1b, and can be connected to piping of a portion where the fluid to be measured is measured.
本実施形態の流量計は、産業機器等で、流体を供給する装置に接続し、装置の流量を測定することで、生産設備の生産条件を監視する目的で使用されるものである。The flowmeter of this embodiment is connected to a device that supplies fluid in industrial equipment, etc., and is used for the purpose of monitoring the production conditions of production equipment by measuring the flow rate of the device.
生産設備の場合、被測定流体は高温の流体の場合があり、流量計には耐熱性を求められる。本実施形態は、それらの要望に応えるものである。In the case of production equipment, the fluid to be measured may be a high-temperature fluid, and flowmeters are required to have heat resistance. This embodiment meets those demands.
Claims (4)
被測定流体の温度と発熱手段部自身の温度との差から被測定流体の流量を検出することを特徴とする熱線式流量計。By disposing a heat generating unit with a heat dissipating surface in contact with the measured fluid in the flow path of the measured fluid, and detecting the temperature of the former heat generating unit that loses heat through heat transfer to the measured fluid, A hot wire flowmeter that detects the flow rate of a measured fluid,
A hot wire flowmeter characterized in that the flow rate of the fluid to be measured is detected from the difference between the temperature of the fluid to be measured and the temperature of the heating means itself.
発熱手段部が、被測定流体の流れの中にあり、発熱手段部で発熱した熱が流量計筐体への熱伝導を防ぐ断熱構造を有することを特徴とする熱線式流量計。By disposing a heat generating unit with a heat dissipating surface in contact with the measured fluid in the flow path of the measured fluid, and detecting the temperature of the former heat generating unit that loses heat through heat transfer to the measured fluid, A hot wire flowmeter that detects the flow rate of a measured fluid,
A hot wire flowmeter characterized in that a heat generating section is located in the flow of a fluid to be measured and has an adiabatic structure that prevents heat generated by the heat generating section from being conducted to a flowmeter housing.
前記発熱手段部の構成部材が、高温（ここでは１００℃以上）の耐熱性能を持つ部材で構成されることを特徴とする熱線式流量計。By disposing a heat generating unit with a heat dissipating surface in contact with the measured fluid in the flow path of the measured fluid, and detecting the temperature of the former heat generating unit that loses heat through heat transfer to the measured fluid, A hot wire flowmeter that detects the flow rate of a measured fluid,
A hot wire flowmeter characterized in that the constituent members of the heat generating means are made of members having heat resistance performance at high temperatures (here, 100° C. or higher).
被測定流体の温度、粘度、密度などを補正して流量を測定することを特徴とする熱線式流量計。By disposing a heat generating unit with a heat dissipating surface in contact with the measured fluid in the flow path of the measured fluid, and detecting the temperature of the former heat generating unit that loses heat through heat transfer to the measured fluid, A hot wire flowmeter that detects the flow rate of a measured fluid,
A hot wire flow meter that measures the flow rate by correcting the temperature, viscosity, density, etc. of the fluid being measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022096109A JP2023165580A (en) | 2022-05-03 | 2022-05-03 | hot wire flowmeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022096109A JP2023165580A (en) | 2022-05-03 | 2022-05-03 | hot wire flowmeter |
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| Publication Number | Publication Date |
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| JP2023165580A true JP2023165580A (en) | 2023-11-16 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2022096109A Pending JP2023165580A (en) | 2022-05-03 | 2022-05-03 | hot wire flowmeter |
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| JP (1) | JP2023165580A (en) |
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2022
- 2022-05-03 JP JP2022096109A patent/JP2023165580A/en active Pending
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