JP2005300244A - Ultrasonic flow meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance measurement accuracy by automatically determining a fluid under measurement to compensate the effect of sound propagation velocity and that of Reynolds number with respect to the fluid. <P>SOLUTION: This ultrasonic flow meter is equipped with a pair of ultrasonic vibrators 2 and 7 capable of transmitting/receiving ultrasonic signals, a propagation time measurement part 5 for measuring the propagation time of ultrasonic wave between the ultrasonic vibrators 2 and 7, a control part 4 for finding the flow volume of the fluid under measurement filling a space between the ultrasonic vibrators 2 and 7, a temperature sensor 11 for measuring the temperature of the fluid, a pressure sensor 12 for measuring the pressure of the fluid, a fluid-under-measurement determination part 13 for determining the kind of the fluid from a correlation between the amplitude of a reception wave voltage received by the vibrator 2 or 7 and the temperature and pressure of the fluid, and a flow correction part 14 for correcting a flow measurement value from the determined kind of a gas based on the Reynolds number, etc. of the gas. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic flowmeter that measures the propagation time of ultrasonic waves using a pair of ultrasonic transducers capable of transmitting and receiving and measures the flow rate of a fluid to be measured.

  Conventional ultrasonic flowmeters are generally as shown in FIG. This apparatus includes a pair of ultrasonic transducers 2 and 7 that can be transmitted and received, and a drive circuit 3 that drives the ultrasonic transducers 2 and 7 installed on the upstream side and the downstream side of the measurement channel 1 through which the fluid to be measured flows. A control unit 4 that outputs a start signal to the drive circuit 3, a propagation time measurement unit 5 that measures the propagation time of ultrasonic waves, a calculation unit 6 that receives measurement data from the propagation time measurement unit 5, and ultrasonic vibration on the reception side The amplifier 8 that amplifies the outputs of the sub-elements 2 and 7 and the reception detection circuit 9 that stops the propagation time measurement unit 5 when the output of the amplifier 8 is compared with the reference voltage and the magnitude relationship is reversed and the transmission / reception of the ultrasonic wave is switched. The changeover switch 10 was provided.

  In the ultrasonic flowmeter, the drive circuit 3 that has received the start signal from the control unit 4 performs pulse driving of the ultrasonic transducer 7 on the upstream side for a certain period of time. Start measuring time by signal. Ultrasound is transmitted from the pulse-driven ultrasonic transducer 7. The ultrasonic wave transmitted from the ultrasonic vibrator 7 propagates through the fluid to be measured and is received by the ultrasonic vibrator 2. The reception output of the ultrasonic transducer 2 is amplified by the amplification factor set by the control unit 4 in the amplifier 8. Then, the reception detection circuit 9 receiving the output of the amplifier 8 determines reception of the ultrasonic wave and stops the propagation time measuring unit 5. In this way, the propagation time t1 of the ultrasonic wave in the flow direction is obtained. The same operation is performed in a state where the transmission / reception of ultrasonic waves is switched by the changeover switch, and the ultrasonic wave propagation time t2 in the direction opposite to the flow is obtained. Then, the calculation unit 6 obtains the flow velocity from the time information t1 and t2 obtained from the propagation time measurement unit 5 by (Equation 1) (however, the propagation time from upstream to downstream is t1, the propagation time from downstream to upstream is t2, L is the effective distance in the flow direction between the acoustic transducers, and v is the flow velocity of the fluid to be measured.

v = L / 2 ((1 / t1)-(1 / t2)) (Formula 1)
According to this method, the flow velocity can be measured without being affected by the change in the sound velocity, and thus it is widely used for measuring the flow velocity, the flow rate, the distance, and the like.
JP 2001-183195 A

  However, the conventional ultrasonic flowmeter has a problem that the measured flow rate value differs for each fluid to be measured due to the sound propagation speed of the fluid to be measured and the number of ray nozzles.

  The present invention solves the above-described conventional problems, and an object thereof is to provide an ultrasonic flowmeter that determines a fluid to be measured, automatically corrects a flow rate measurement value for each gas, and improves measurement accuracy. To do.

  In order to solve the above-described conventional problems, an ultrasonic flowmeter of the present invention includes a pair of ultrasonic transducers capable of transmitting and receiving an ultrasonic signal, and is transmitted from one of the ultrasonic transducers and propagates through a fluid to be measured. A propagation time measurement unit that measures the propagation time of the ultrasonic wave until the other ultrasonic transducer receives the ultrasonic signal, and the flow rate of the fluid to be measured that fills the space between the ultrasonic transducers by calculation from the propagation time. A control unit to be obtained; a temperature sensor for measuring the temperature of the fluid to be measured; a pressure sensor for measuring the pressure of the fluid to be measured; the propagation time; the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side; A fluid to be measured discriminating unit for discriminating the type of fluid to be measured from the correlation between the temperature and pressure of the fluid to be measured, and a flow rate correcting unit for correcting a flow rate measurement value from the discriminated gas type.

  As a result, even when the fluid to be measured changes, it is possible to always measure the flow rate accurately without being affected by the sound propagation speed of the fluid to be measured and the number of ray nozzles.

  The ultrasonic flowmeter of the present invention can always measure the flow rate accurately without being affected by the propagation speed of sound of the fluid to be measured and the number of ray nozzles even if the fluid to be measured changes. In addition, there is no need to replace the flow meter, and the type of gas can be confirmed.

  According to a first aspect of the present invention, a pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals, and an ultrasonic signal transmitted from one ultrasonic transducer and propagated through a fluid to be measured are transmitted to the other ultrasonic transducer. A propagation time measurement unit that measures the propagation time of ultrasonic waves until reception, a control unit that obtains a flow rate of the fluid to be measured that satisfies the ultrasonic transducer from the propagation time, and measures the temperature of the fluid to be measured A fluid to be measured from the correlation between the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side, and the temperature and pressure of the fluid to be measured. A fluid to be measured discriminating unit for discriminating the type of gas, and a flow rate correcting unit for correcting the flow rate measurement value based on the discriminated gas type on the basis of the Reynolds number of the gas. The sound propagation speed of the measurement fluid, Without being affected by Inozuru number, it is possible to always accurate flow measurement.

  According to a second aspect of the present invention, a pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals, and an ultrasonic signal transmitted from one ultrasonic transducer and propagated through a fluid to be measured are transmitted to the other ultrasonic transducer. A propagation time measurement unit that measures the propagation time of ultrasonic waves until reception, a control unit that obtains a flow rate of the fluid to be measured that satisfies the ultrasonic transducer from the propagation time, and measures the temperature of the fluid to be measured A pressure sensor that measures the pressure of the fluid to be measured, an amplification factor adjustment unit that adjusts the amplification factor so that the received wave voltage received by the ultrasonic transducer on the reception side always has the same amplitude, A fluid to be measured discriminating unit for discriminating the type of fluid to be measured from the correlation between the propagation time, the amplification factor of the received wave voltage, and the temperature and pressure of the fluid to be measured; Flow to be corrected based on number, etc. By providing a correction unit, it can determine more accurately the type of the fluid to be measured.

  According to a third aspect of the present invention, a pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals, and an ultrasonic signal transmitted from one ultrasonic transducer and propagated through a fluid to be measured are transmitted to the other ultrasonic transducer. Sets the propagation time measurement unit that measures the propagation time of ultrasonic waves until reception, the control unit that calculates the flow rate of the fluid to be measured that satisfies the ultrasonic transducer from the propagation time, and the type of fluid to be measured A type setting means, and a temperature calculation unit that calculates the temperature of the fluid to be measured from the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side, and the type of the fluid to be measured, When the type of fluid to be measured is known, the flow value and temperature can be measured simultaneously.

  According to a fourth aspect of the present invention, in the third aspect of the invention, in the third aspect of the invention, the pressure calculating unit for calculating the pressure of the fluid to be measured from the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side, and the type of the fluid to be measured When the type of the fluid to be measured is known, the flow value and the pressure can be measured simultaneously.

  The fifth aspect of the invention includes a display unit for displaying at least one of the type and flow rate, temperature, and pressure of the fluid to be measured, particularly in any one of the first to fourth aspects of the invention. The type, flow rate, temperature, and pressure of the fluid can be visually confirmed.

  In the sixth invention, in particular, as the display part of the fifth invention, the flow direction and the flow rate of the fluid to be measured are expressed by the direction and size of the arrow, and the state of the fluid to be measured can be visually determined. Easy to do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a configuration diagram of an ultrasonic flowmeter according to the first embodiment of the present invention.

  As shown in FIG. 1, the ultrasonic flowmeter of the present invention transmits a pair of ultrasonic transducers 2 and 7 capable of transmitting and receiving an ultrasonic signal and one of the ultrasonic transducers 2 and 7 to transmit a fluid to be measured. A propagation time measurement unit 5 that measures the propagation time of the ultrasonic wave until the other ultrasonic transducers 2 and 7 receive the propagated ultrasonic signal, and between the ultrasonic transducers 2 and 7 by calculation from the propagation time A control unit 4 for obtaining the flow rate of the fluid to be measured that satisfies the conditions, a temperature sensor 11 for measuring the temperature of the fluid to be measured, a pressure sensor 12 for measuring the pressure of the fluid to be measured, and the propagation time and ultrasonic vibration on the receiving side. The fluid to be measured discriminating unit 13 for discriminating the type of the fluid to be measured from the correlation between the amplitude of the received wave voltage received by the children 2 and 7 and the temperature and pressure of the fluid to be measured, A flow rate correction unit 14 for correcting based on the Reynolds number of the And a display unit 15 for displaying the flow rate at the time of measurement and the type of the fluid to be measured.

  About the ultrasonic flowmeter comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, as the basic operation, as described in the background art, the flow direction of the fluid to be measured and the propagation time of the ultrasonic wave in the direction opposite to the flow are measured. In addition to the operation of the conventional ultrasonic flowmeter, in the first embodiment of the present invention, at the time of propagation time measurement, the temperature sensor 11 and the pressure sensor 12 measure the temperature and pressure of the fluid to be measured, and the amplitude measurement unit At 16, the amplitude of the received wave of the ultrasonic voltage is measured. Then, the propagation time, temperature, pressure, and received wave for each kind of gas set in advance from the measured ultrasonic propagation time, temperature, pressure, and amplitude of the received wave voltage in the measured fluid discriminating unit 13. Based on the amplitude correlation table, the type of gas currently measured is determined. Next, the flow rate correction value calculated by the calculation unit 6 is corrected by the flow rate correction unit 14 based on the Reynolds number of the gas determined by the measured fluid determination unit 13.

  As described above, in this embodiment, the temperature sensor 11, the pressure sensor 12, the measured fluid discriminating unit 13, and the flow rate correcting unit 14 are provided, so that the sound of the measured fluid propagates even if the measured fluid changes. Accurate flow measurement is always possible without being affected by speed or number of lay nozzles.

(Embodiment 2)
FIG. 2 shows a configuration diagram of an ultrasonic flowmeter according to the second embodiment of the present invention.
As shown in FIG. 2, the difference from the first embodiment is that the measured fluid discrimination unit 13 uses the amplification factor of the amplifier 8 instead of the amplitude of the received wave voltage of the ultrasonic wave. .

  And in the ultrasonic flowmeter in which the amplification factor of the amplifier 8 is adjusted by the amplification factor adjustment unit 17 so that the amplitude of the reception waveform after amplification is the same for improving the accuracy in the reception detection circuit 9. As in the first embodiment, the temperature sensor 11, the pressure sensor 12, the measured fluid discriminating unit 13, and the flow rate correcting unit 14 are provided, so that the sound of the measured fluid propagates even if the measured fluid changes. Accurate flow measurement is always possible without being affected by speed or number of lay nozzles.

(Embodiment 3)
FIG. 3 shows a configuration diagram of an ultrasonic flowmeter according to the third embodiment of the present invention.

  As shown in FIG. 3, the ultrasonic flowmeter is transmitted from a pair of ultrasonic transducers 2 and 7 capable of transmitting and receiving ultrasonic signals and one of the ultrasonic transducers 2 and 7 and propagates through the fluid to be measured. A propagation time measuring unit 5 that measures the propagation time of the ultrasonic wave until the other ultrasonic vibrators 2 and 7 receive the ultrasonic signal, and a fluid to be measured that fills the space between the ultrasonic vibrators by calculation from the propagation time Control unit 4 for determining the flow rate of the fluid, type setting means 4a for setting the type of the fluid to be measured, propagation time, amplitude of the received wave voltage received by the ultrasonic transducers 2 and 7 on the receiving side, and the fluid to be measured The temperature calculation unit 18 that calculates the temperature of the fluid to be measured from the types of the above, and the display unit 15 that displays the type of the fluid to be measured, the flow rate and the temperature at the time of measurement.

  About the ultrasonic flowmeter comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, as the basic operation, as described in the background art, the flow direction of the fluid to be measured and the propagation time of the ultrasonic wave in the direction opposite to the flow are measured. In addition to the operation of the conventional ultrasonic flowmeter, the pressure of the fluid to be measured is measured by the pressure sensor 12 and the amplitude of the received wave voltage of the ultrasonic wave is measured by the amplitude measuring unit 16 when measuring the propagation time. Then, based on the measured propagation time of the ultrasonic wave and the amplitude of the received wave voltage, the temperature calculation unit 18 is based on a correlation table of the propagation time, temperature, and amplitude of the received wave voltage for each preset gas type. Next, the temperature of the gas currently measured is calculated.

  As described above, in the present embodiment, the flow rate and the temperature of the fluid to be measured can be measured without providing the temperature sensor when the fluid to be measured is known by providing the temperature calculation unit 18. .

(Embodiment 4)
FIG. 4 shows a configuration diagram of an ultrasonic flowmeter according to the fourth embodiment of the present invention.

  As shown in FIG. 4, in addition to the third embodiment, the ultrasonic flowmeter receives the propagation time and the reception by the ultrasonic transducers 2 and 7 on the receiving side by setting the type of fluid to be measured. A pressure calculation unit 19 that calculates the pressure of the fluid to be measured from the amplitude of the wave voltage, and a display unit that displays the type of the fluid to be measured, the flow rate at the time of measurement, the temperature and the pressure.

  About the ultrasonic flowmeter comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, as the basic operation, as described in the background art, the flow direction of the fluid to be measured and the propagation time of the ultrasonic wave in the direction opposite to the flow are measured. In addition to the operation of the conventional ultrasonic flowmeter, the amplitude measurement unit 16 measures the amplitude of the received wave voltage of the ultrasonic wave during the propagation time measurement. Then, the pressure calculation unit 19 uses the measured ultrasonic propagation time and the amplitude and temperature of the received wave voltage to correlate the propagation time, temperature and received wave voltage amplitude for each preset gas type. Based on the above, the gas pressure currently measured is calculated.

  As described above, in the present embodiment, by providing the pressure calculation unit 19, when the fluid to be measured is known, the flow rate, temperature, and pressure of the fluid to be measured can be measured without providing a pressure sensor. Can do.

  Further, when the liquid crystal display element is used as the display unit 15 and the flow direction of the fluid to be measured is expressed by the direction of the arrow and the flow rate is expressed by the size of the arrow, The visibility of the direction is improved, and the gas state can be easily grasped by displaying the type, temperature, and pressure of the gas on the same liquid crystal display unit.

  As described above, the ultrasonic flowmeter according to the present invention can always measure the flow rate accurately without being influenced by the sound propagation speed of the fluid to be measured and the number of lay nozzles even if the fluid to be measured changes. Therefore, it is not necessary to replace the flowmeter for each fluid to be measured, and the type of gas can be confirmed, so it is also applicable to equipment that needs to measure multiple types of gas and applications such as gas meters it can. In addition, a single flow meter can be used for equipment that requires measurement of gas flow rate, temperature, and pressure.

Configuration diagram of ultrasonic flowmeter in Embodiment 1 of the present invention Configuration diagram of ultrasonic flowmeter in embodiment 2 of the present invention The block diagram of the ultrasonic flowmeter in Embodiment 3 of this invention The block diagram of the ultrasonic flowmeter in Embodiment 4 of this invention Configuration diagram of conventional ultrasonic flowmeter

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measurement flow path 2, 7 Ultrasonic vibrator 4 Control part 4a Type setting means 5 Propagation time measurement part 9 Reception detection circuit 11 Temperature sensor 12 Pressure sensor 13 Fluid to be measured discrimination | determination part 14 Flow volume correction part 15 Display part 17 Gain adjustment Section 18 Temperature calculation section 19 Pressure calculation section

Claims (6)

A pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals and ultrasonic waves transmitted from one of the ultrasonic transducers until the other ultrasonic transducer receives an ultrasonic signal transmitted through the fluid to be measured A propagation time measurement unit that measures the propagation time of the measurement fluid, a control unit that obtains a flow rate of the fluid to be measured that fills between the ultrasonic transducers by calculation from the propagation time, a temperature sensor that measures the temperature of the fluid to be measured, A pressure sensor for measuring the pressure of the fluid to be measured, and a type of fluid to be measured that determines the type of fluid to be measured from the correlation between the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side, and the temperature and pressure of the fluid to be measured. An ultrasonic flowmeter comprising: a measurement fluid discrimination unit; and a flow rate correction unit that corrects a flow rate measurement value based on the discriminated gas type based on the Reynolds number of the gas. A pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals and ultrasonic waves transmitted from one of the ultrasonic transducers until the other ultrasonic transducer receives an ultrasonic signal transmitted through the fluid to be measured A propagation time measurement unit that measures the propagation time of the measurement fluid, a control unit that obtains a flow rate of the fluid to be measured that fills between the ultrasonic transducers by calculation from the propagation time, a temperature sensor that measures the temperature of the fluid to be measured, A pressure sensor that measures the pressure of the measurement fluid; an amplification factor adjustment unit that adjusts the amplification factor so that the reception wave voltage received by the ultrasonic transducer on the reception side always has the same amplitude; the propagation time and the reception Measured fluid discriminating unit that discriminates the type of fluid to be measured from the correlation between wave voltage amplification factor and temperature and pressure of the fluid to be measured, and corrects the measured flow rate based on the Reynolds number of the gas etc. Equipped with a flow correction unit Ultrasonic flow meter. A pair of ultrasonic transducers capable of transmitting and receiving ultrasonic signals and ultrasonic waves transmitted from one of the ultrasonic transducers until the other ultrasonic transducer receives an ultrasonic signal transmitted through the fluid to be measured A propagation time measurement unit that measures the propagation time of the control unit, a control unit that obtains a flow rate of the fluid to be measured that satisfies the space between the ultrasonic transducers by calculation from the propagation time, a type setting unit that sets a type of the fluid to be measured, The ultrasonic flowmeter provided with the temperature calculation part which calculates the temperature of the fluid to be measured from the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the receiving side, and the type of the fluid to be measured. The ultrasonic flowmeter according to claim 3, further comprising: a pressure calculation unit that calculates the pressure of the fluid to be measured from the propagation time, the amplitude of the received wave voltage received by the ultrasonic transducer on the reception side, and the type of the fluid to be measured. . The ultrasonic flowmeter according to any one of claims 1 to 4, further comprising a display unit for displaying at least one of the type and flow rate, temperature, and pressure of the fluid to be measured. 6. The ultrasonic flowmeter according to claim 5, wherein the display unit displays the flow direction of the fluid to be measured and the magnitude of the flow rate in the direction and size of an arrow.

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