WO2018079269A1 - Fluid measuring device - Google Patents

Fluid measuring device Download PDF

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Publication number
WO2018079269A1
WO2018079269A1 PCT/JP2017/036900 JP2017036900W WO2018079269A1 WO 2018079269 A1 WO2018079269 A1 WO 2018079269A1 JP 2017036900 W JP2017036900 W JP 2017036900W WO 2018079269 A1 WO2018079269 A1 WO 2018079269A1
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Prior art keywords
flow rate
fluid
calculation unit
reynolds number
error
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PCT/JP2017/036900
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French (fr)
Japanese (ja)
Inventor
木代 雅巳
泰文 森本
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富士電機株式会社
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Publication of WO2018079269A1 publication Critical patent/WO2018079269A1/en

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/66Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N11/00Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
    • G01N11/02Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material
    • G01N11/04Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties by measuring flow of the material through a restricted passage, e.g. tube, aperture
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/02Analysing fluids
    • G01N29/024Analysing fluids by measuring propagation velocity or propagation time of acoustic waves
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01PMEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/24Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring the direct influence of the streaming fluid on the properties of a detecting acoustical wave

Definitions

  • the present invention relates to a fluid measuring apparatus that measures a physical quantity such as a flow rate of a fluid in a pipe and a Reynolds number by ultrasonic waves.
  • a flow rate measuring device using ultrasonic waves for measuring the flow rate of a fluid flowing through a pipe (see Patent Document 1).
  • a plurality of ultrasonic transmission / reception units are arranged in a pipe, and ultrasonic transmission / reception is alternately performed, and a flow rate is detected from a difference in propagation time.
  • the flow velocity of the fluid can use a measured value based on a signal obtained from the ultrasonic transmission / reception unit, but it is necessary to input representative values in advance for the piping dimensions and kinematic viscosity.
  • kinematic viscosity varies with fluid temperature.
  • Patent Document 1 the Gaussian numerical integration method is applied, and the average flow velocity of the pipe cross section is obtained by weighted addition of the average flow velocity measured at the n-point survey line.
  • the flow velocity distribution includes high-order terms so that it can be approximated by an exponential function known by the 1 / n power law, for example, in a turbulent flow region.
  • an integration error occurs.
  • the flow velocity distribution which was a parabola in the laminar basin, greatly changes to the shape of an exponential function of 1 / n power in the turbulent region. .
  • the error greatly varies depending on the Reynolds number, and the flow rate of the fluid cannot be obtained accurately.
  • the Reynolds number varies with the flow velocity and kinematic viscosity, so it is laminar when the flow velocity is low, but it becomes turbulent when the flow velocity is high, or it is laminar with a large kinematic viscosity at low temperatures. In the case where becomes smaller and becomes turbulent, there is a problem that accurate measurement cannot be performed from the laminar flow region to the turbulent flow region.
  • the present invention has been made in view of such problems, and the object of the present invention is to measure the physical quantity of fluid with higher accuracy than conventional methods regardless of laminar flow and turbulent flow. It is to provide a fluid measuring device.
  • the fluid measuring device of the present invention forms a plurality of measurement lines by transmitting and receiving ultrasonic waves from a plurality of ultrasonic transmission / reception units installed in a pipe to the fluid in the pipe, and the control unit obtains a physical quantity of the fluid.
  • the control unit calculates a flow rate of the fluid measured along the plurality of survey lines, a flow rate ratio calculation unit that calculates a flow rate ratio based on the flow rate of the fluid, and the flow rate A physical quantity computing unit that computes the physical quantity based on the ratio.
  • This configuration makes it possible to measure the physical quantity of fluid with high accuracy regardless of laminar or turbulent flow.
  • the flow rate ratio of the fluid is obtained, and the physical quantity of the fluid is calculated based on the flow rate ratio.
  • the physical quantity of fluid can be measured with high accuracy regardless of laminar flow or turbulent flow.
  • FIG. 2 is a block diagram of the fluid measuring device according to the first embodiment (including a pipe cut along the line AA shown in FIG. 1 and viewed from the arrow direction, and a partial cross-sectional view of the ultrasonic probe). It is a graph showing the correlation between the flow rate ratio of fluid and the Reynolds (Re) number. It is a graph showing the correlation between the Reynolds (Re) number and the error ⁇ .
  • FIG. 5 is a block diagram of a fluid measuring device according to a second embodiment (including a pipe cut along line AA shown in FIG.
  • FIG. 7 is a graph showing a correlation between a flow rate ratio and an error ⁇ after correcting the error of FIG. 6.
  • FIG. 1 is a front view showing an arrangement of ultrasonic probes constituting the fluid measuring device of the present embodiment on a pipe.
  • the pipe 100 has a cylindrical shape, and three sets of ultrasonic probes (ultrasonic wave transmission / reception units) are arranged in the pipe 100. That is, the ultrasonic probe 10a and the ultrasonic probe 10b shown in FIG. 1 are combined, the ultrasonic probe 13a and the ultrasonic probe 13b are combined, and the ultrasonic probe 14a and the ultrasonic probe 14b are combined. It is a pair.
  • the three measurement lines ⁇ , the measurement line ⁇ , and the measurement line ⁇ of the ultrasonic waves transmitted and received between each set of ultrasonic probes are parallel to each other.
  • the measurement line ⁇ crosses the pipe 100 through the center of the pipe 100, and the measurement line ⁇ and the measurement line ⁇ are in symmetrical positions with the measurement line ⁇ in between.
  • R represents the inner radius of the pipe 100, and r represents the distance between the measurement line ⁇ and the measurement line ⁇ , and the distance between the measurement line ⁇ and the measurement line ⁇ .
  • the survey line position r / R can be appropriately determined based on a numerical integration method such as a Gaussian numerical integration method.
  • the pipe 100 is not limited to a cylindrical shape, and may not be three survey lines if the number of survey lines is plural. Further, the measurement line ⁇ may not pass through the center of the pipe 100, and the measurement line ⁇ and the measurement line ⁇ are not limited to being symmetrical with respect to the measurement line ⁇ .
  • Each of the survey lines ⁇ , ⁇ , ⁇ is not limited to being parallel, but by making each of the survey lines ⁇ , ⁇ , ⁇ parallel, the accuracy of numerical integration for obtaining the average flow velocity is improved. Can be improved.
  • FIG. 2 is a block diagram of the fluid measuring apparatus 1 according to the first embodiment. 2 also includes a partial cross-sectional view of the pipe 100 and the ultrasonic probes 10a and 10b cut along the line AA shown in FIG. 1 and viewed from the arrow direction.
  • the fluid measuring apparatus 1 includes a plurality of ultrasonic probes 10a, 10b, 13a, 13b, 14a, 14b installed in a pipe 100 (however, in FIG. 2, the ultrasonic probe 10a). 10b only) and a control unit 60 for calculating the physical quantity of the fluid 102.
  • ultrasonic probes 10a and 10b are arranged on the outer surfaces 101a and 101b of the pipe 100 as shown in the partial cross-sectional view of FIG.
  • the ultrasonic probes 13a, 13b, 14a, and 14b that are not shown are the same as those described below except for the arrangement of the ultrasonic probes 10a and 10b.
  • the ultrasonic probe 10 a is arranged on the upstream side with respect to the flow of the fluid 102 in the pipe 100, and the ultrasonic probe 10 b is arranged on the downstream side with respect to the flow of the fluid 102.
  • the ultrasonic probe 10a is configured to include an ultrasonic transducer 11a and a wedge 12a
  • the ultrasonic probe 10b is configured to include an ultrasonic transducer 11b and a wedge 12b.
  • the ultrasonic transducers 11 a and 11 b are disposed obliquely with respect to the flow direction of the fluid 102.
  • each ultrasonic transducer 11a, 11b is connected to a switch 33a, 33b, respectively.
  • the ultrasonic probes 13a and 13b shown in FIG. 1 are electrically connected to the switches 34a and 34b shown in FIG. 2, and the ultrasonic probes 14a and 14b shown in FIG. It is electrically connected to 35a, 35b.
  • the control unit 60 includes a transmission unit 31, a reception unit 32, a time measurement unit 40, a switch switching unit 41, a flow rate calculation unit 42, a flow rate ratio calculation unit 43, a Reynolds number calculation unit 46, a flow rate ratio ⁇
  • the Reynolds number conversion table 47, the error calculation unit 44, the Reynolds number-error conversion table 48, the flow rate calculation unit 50, and the viscosity calculation unit 51 are configured.
  • the transmission unit 31 is electrically connected to each switch 33a, 33b, 34a, 34b, 35a, 35b.
  • the transmission unit 31 transmits an electrical signal to an ultrasonic transducer that is electrically connected to the switch to generate an ultrasonic wave.
  • the receiving unit 32 is electrically connected to the switches 33a, 33b, 34a, 34b, 35a, and 35b.
  • the receiving unit 32 receives an electrical signal from an ultrasonic transducer that is electrically connected to the switch.
  • the time measurement unit 40 is electrically connected to the transmission unit 31 and the reception unit 32.
  • the time measuring unit 40 measures the propagation time from transmission to reception of ultrasonic waves on each of the measurement lines ⁇ , ⁇ , and ⁇ (see FIG. 1).
  • the flow velocity calculation unit 42 is electrically connected to the time measurement unit 40.
  • the flow velocity calculation unit 42 calculates the flow velocity of each of the measurement lines ⁇ , ⁇ , and ⁇ of the fluid 102 based on the propagation time transmitted from the time measurement unit 40. Further, the flow velocity calculation unit 42 calculates the average flow velocity of the entire pipe cross section by weighting and adding to each of the survey lines ⁇ , ⁇ , ⁇ by, for example, the Gaussian numerical integration method.
  • the flow rate ratio calculation unit 43 is electrically connected to the flow rate calculation unit 42.
  • the flow rate ratio calculation unit 43 calculates the flow rate ratio based on the flow rates of the respective survey lines ⁇ , ⁇ , and ⁇ obtained by the flow rate calculation unit 42.
  • the Reynolds number calculation unit 46 is electrically connected to the flow rate ratio calculation unit 43.
  • the Reynolds number calculator 46 calculates the Reynolds (Re) number based on the flow rate ratio.
  • the flow rate ratio / Reynolds number conversion table 47 is electrically connected to the Reynolds number calculation unit 46.
  • the flow rate ratio-Reynolds number conversion table 47 is prepared in advance for calculating the Reynolds number and the flow rate. In the flow rate ratio-Reynolds number conversion table 47, the flow rate ratio and the Reynolds number are correlated.
  • the Reynolds number calculation unit 46 calculates the Reynolds number from the flow rate ratio-Reynolds number conversion table 47 based on the flow rate ratio.
  • the error calculation unit 44 is electrically connected to the Reynolds number calculation unit 46.
  • the error calculation unit 44 obtains an error (integration error) of the average flow velocity obtained by the flow velocity calculation unit 42. In the embodiment shown in FIG. 2, this error is obtained from the relationship between the Reynolds number and the error.
  • the Reynolds number-error conversion table 48 is electrically connected to the error calculation unit 44.
  • the Reynolds number-error conversion table 48 is prepared in advance for calculating the flow rate.
  • the Reynolds number and the error are correlated.
  • the error calculator 44 calculates an error from the Reynolds number-error conversion table 48 based on the Reynolds number acquired from the Reynolds number calculator 46.
  • the flow rate calculation unit 50 is electrically connected to the flow rate calculation unit 42 and the error calculation unit 44.
  • the flow rate calculation unit 50 calculates the flow rate based on the average flow velocity and the error.
  • the transmission unit 31 and the switch 33a are electrically connected by a signal from the switch switching unit 41.
  • vibrator 11a and the transmission part 31 are electrically connected via the switch 33a.
  • the receiving unit 32 and the switch 33b are electrically connected by a signal from the switch switching unit 41.
  • vibrator 11b and the receiving part 32 are electrically connected via the switch 33b.
  • the transmission unit 31 transmits an electrical signal to the ultrasonic transducer 11a to generate an ultrasonic wave.
  • the generated ultrasonic wave passes through the wedge 12 a and enters the fluid 102 in the pipe 100.
  • the ultrasonic wave incident on the fluid 102 in the pipe 100 propagates in the fluid 102 at an incident angle ⁇ from the upstream side to the downstream side of the fluid 102.
  • the ultrasonic wave propagated to the ultrasonic probe 10b is converted into an electric signal by the ultrasonic transducer 11b. This electrical signal is received by the receiving unit 32 via the switch 33b.
  • the time measuring unit 40 measures the propagation time from transmission to reception of ultrasonic waves.
  • the propagation time along the flow of the fluid 102 is Tf.
  • the switch 33a and the switch 33b are respectively switched by a signal from the switch switching unit 41 (shown by dotted lines in the switch 33a and the switch 33b. The same applies to FIG. 5 described later).
  • vibrator 11a and the receiving part 32 are electrically connected via the switch 33a, and the ultrasonic transducer
  • the ultrasonic waves propagate from the downstream ultrasonic transducer 11b toward the upstream ultrasonic transducer 11a.
  • the ultrasonic wave propagated to the ultrasonic probe 10a is converted into an electric signal by the ultrasonic transducer 11a. This electric signal is received by the receiving unit 32 via the switch 33a.
  • the time measuring unit 40 measures the propagation time of the ultrasonic wave against the flow of the fluid 102 as Tr.
  • the propagation times Tf and Tr of the survey line ⁇ shown in FIG. 1 can be acquired.
  • the propagation time of the ultrasonic waves is affected by the flow of the fluid 102, so that Tf is short and Tr is long. Since the difference between Tf and Tr changes according to the flow velocity of the fluid 102, the average flow velocity on the measurement line of the fluid 102 can be measured by measuring this difference.
  • each switch 34a, 34b, 35a, 35b is switched between transmission and reception by a signal from the switch switching unit 41, and the propagation times Tf, Tr of the survey lines ⁇ , ⁇ are obtained in the same manner as described above. To do.
  • the propagation times Tf and Tr of the measurement lines ⁇ , ⁇ , and ⁇ are transmitted from the time measurement unit 40 to the flow velocity calculation unit 42. Then, the flow velocity calculation unit 42 calculates the flow velocity V of the fluid 102 from the propagation times Tf and Tr.
  • the propagation times Tf and Tr are expressed by the following mathematical formulas (1) and (2).
  • C is the speed of sound of the fluid 102
  • is the incident angle
  • L is the propagation path length through which the ultrasonic wave propagates in the fluid 102.
  • V L / 2 cos ⁇ ⁇ ((1 / Tf) ⁇ (1 / Tr)) (3)
  • the flow velocity calculation unit 42 obtains the average flow velocity of the entire pipe cross section by weighting each of the survey lines ⁇ , ⁇ , ⁇ , for example, based on the Gaussian numerical integration method.
  • the Gaussian numerical integration method is one of the numerical integration methods in which the integration of the (2n-1) degree polynomial is obtained by weighted addition of n points. That is, the average flow velocity of the entire pipe cross section can be obtained by weighted addition of the average flow velocity measured at the n-point survey line. This average flow velocity can be determined regardless of the Reynolds number.
  • the average flow velocity can be obtained as an integral value of w1 ⁇ v1 + w2 ⁇ v2 + w3 ⁇ v3.
  • w1, w2, and w3 are weighted addition values for the flow velocity values v1, v2, and v3, respectively, and the weighted addition values w1, w2, and w3 are specified values.
  • there are 3 survey lines (n 3).
  • the weighted addition value of the survey line ⁇ (that is, the flow velocity value v1) is 0.4444444 (rounded to the eighth decimal place).
  • the weighted addition value of the measurement lines ⁇ and ⁇ (that is, the flow velocity values v2 and v3) is 0.2777778 (rounded to the eighth decimal place).
  • a numerical integration method to be applied the Gaussian numerical integration method is representatively used.
  • a Chebyshev integration method or a Lobat integration method can be used in addition to the Gaussian numerical integration method.
  • the numerical integration method as in the normal integration method, when obtaining the area, the area is not divided into strips and all the strip areas are added, but weighted addition is performed at a specific location.
  • the numerical integration method is applied to the fluid measurement device of the present embodiment, the average flow velocity of the entire pipe cross section can be obtained by weighted addition of the flow velocity of the survey line at a specific location.
  • the integration error fluctuation becomes large.
  • the relationship between the flow rate ratio or the Reynolds number correlated with the flow rate ratio and the error is found, and the error can be estimated from the flow rate ratio and the Reynolds number. A specific method for obtaining the error will be described later.
  • the flow velocity ratio calculation unit 43 calculates the flow rate ratio Vr from the flow rate values v1, v2, and v3.
  • the measurement line ⁇ passes through the center of the pipe 100, and the measurement line ⁇ and the measurement line ⁇ are located symmetrically with respect to the measurement line ⁇ .
  • the Reynolds number calculator 46 calculates the Reynolds (Re) number based on the flow rate ratio obtained from the flow rate ratio calculator 43.
  • the relationship between the flow rate ratio Vr and the Reynolds number is derived in advance by simulation or the like.
  • the simulation result is stored in the control unit 60 of the fluid measuring apparatus 1 as a flow rate ratio-Reynolds number conversion table 47.
  • the Reynolds (Re) number can be calculated from the flow rate ratio-Reynolds number conversion table 47 using the flow rate ratio Vr obtained from the flow rate ratio calculation unit 43.
  • FIG. 3 is a graph showing the correlation between the fluid flow rate ratio and the Reynolds (Re) number.
  • the correlation shown in FIG. 3 is numerically analyzed using a 1 / n power law (specifically, a 1/7 power law) as an approximate expression of the turbulent flow velocity distribution and a parabola as a laminar flow velocity distribution. Can be obtained.
  • the Reynolds (Re) number decreases substantially monotonically with respect to the flow rate ratio Vr.
  • the turbulent flow region shown by the solid line in FIG. 3 there is only one Reynolds number corresponding to the flow velocity ratio Vr, and the Reynolds number can be uniquely obtained. 4, 6, and 7, similarly, the turbulent flow region is indicated by a solid line.
  • the flow rate ratio Vr in the laminar flow is a constant value.
  • the Reynolds number cannot be specified from the flow rate ratio, but the error occurring in the laminar basin is a constant value as will be described later, and therefore the error can be corrected.
  • the dotted line shown in FIG. 3 has shown the transition area
  • the laminar flow has a constant value, and the transition region is indicated by a dotted line.
  • the flow rate ratio-Reynolds number conversion table 47 shown in FIG. 2 constitutes a conversion table based on the graph shown in FIG. Therefore, the Reynolds (Re) number can be calculated from the flow rate ratio-Reynolds number conversion table 47 using the flow rate ratio Vr obtained from the flow rate ratio calculation unit 43.
  • the error calculation unit 44 shown in FIG. 2 calculates the error ⁇ based on the Reynolds number acquired by the Reynolds number calculation unit 46.
  • the error ⁇ corresponds to an integration error with respect to the average flow velocity obtained by a numerical integration method such as a Gaussian numerical integration method.
  • the correlation between the Reynolds number and the error ⁇ is prepared in advance in the Reynolds number-error conversion table 48.
  • the relationship between the Reynolds number and the error ⁇ is derived by simulation in advance.
  • the simulation result is stored as a Reynolds number-error conversion table 48 in the control unit 60 of the fluid measuring apparatus 1.
  • the error ⁇ can be calculated from the Reynolds number-error conversion table 48 using the Reynolds number obtained from the Reynolds number calculation unit 46.
  • FIG. 4 is a graph showing the correlation between the Reynolds (Re) number and the error ⁇ .
  • FIG. 4 shows the correlation with the error of the flow rate measurement value obtained by weighted addition using the numerical integration method.
  • the error ⁇ is a constant value.
  • FIG. 3 it has been described that the Reynolds number cannot be specified in the laminar basin. However, since it is understood that the laminar basin is present, the error ⁇ can be obtained.
  • the Reynolds number-error conversion table 48 shown in FIG. 2 constitutes a conversion table based on the graph shown in FIG. Therefore, the error ⁇ can be calculated from the Reynolds number-error conversion table 48 using the Reynolds number obtained from the Reynolds number calculation unit 46.
  • the flow rate calculation unit 50 shown in FIG. 2 calculates the flow rate Q by the following formula (5).
  • A (w1 ⁇ v1 + w2 ⁇ v2 + w3 ⁇ v3) ⁇ (100 / (100 + ⁇ )) (5)
  • A is a cross-sectional area of the pipe 100 and is represented by the following formula (6) using the inner diameter D (inner radius R ⁇ 2) of the pipe 100.
  • D inner radius R ⁇ 2
  • Equation (5) The parts of w1, v1 + w2, v2 + w3, and v3 shown in Equation (5) indicate the average flow velocity, and the error ⁇ corresponds to the integration error of the average flow velocity. Therefore, the flow rate Q can be calculated by adding the error ⁇ by the calculation of the equation (5), whereby the flow rate Q can be calculated with high accuracy.
  • Equation (8) calculates the kinematic viscosity ⁇ of the fluid 102 using Equation (8) obtained by modifying the following Equation (7) for obtaining the Reynolds number.
  • Re D ⁇ v / ⁇ (7)
  • D ⁇ v / Re (8)
  • the flow velocity value v1 of the survey line ⁇ passing through the center of the pipe 100 shown in FIG. 1 can be used as the flow velocity v shown in the mathematical formulas (7) and (8).
  • FIG. 5 is a block diagram of the fluid measuring apparatus 1 according to the second embodiment. 5 includes a partial cross-sectional view of the pipe 100 and the ultrasonic probes 10a and 10b cut along the line AA shown in FIG. 1 and viewed from the arrow direction. In the following, description will be made centering on differences from the block diagram of the first embodiment shown in FIG.
  • the Reynolds number calculation unit 46, the flow rate ratio-Reynolds number conversion table 47, the Reynolds number-error conversion table 48, and the viscosity calculation unit 51 shown in FIG. 2 are not provided.
  • the error calculation unit 44 is electrically connected to the flow rate ratio calculation unit 43, and the error calculation unit 44 acquires the flow rate ratio from the flow rate ratio calculation unit 43. Then, the error ⁇ is calculated based on the flow rate ratio.
  • the flow rate ratio-error conversion table 45 is electrically connected to the error calculation unit 44.
  • the flow rate ratio-error conversion table 45 is prepared in advance for calculating the flow rate.
  • the flow rate ratio and the error ⁇ are correlated.
  • the error calculator 44 calculates an error ⁇ from the flow rate ratio-error conversion table 45 based on the flow rate ratio.
  • the flow rate calculation unit 50 is electrically connected to the flow rate calculation unit 42 and the error calculation unit 44.
  • the flow rate calculation unit 50 calculates the flow rate based on the average flow velocity and the error.
  • FIG. 6 is a graph showing the correlation between the flow rate ratio and the error ⁇ . 3 and 4 described above, the Reynolds number can be obtained from the flow rate ratio, and the error ⁇ can be estimated from the Reynolds number. Therefore, the error ⁇ can be estimated from the flow rate ratio.
  • the relationship between the flow velocity ratio and the error ⁇ can be approximated by a quadratic function (least square method) or can be approximated by a broken line.
  • an equation approximated by a quadratic function is derived from the flow rate ratio-error conversion table 45, and the flow rate ratio acquired from the flow rate ratio calculation unit 43 is approximated by a quadratic function.
  • the error ⁇ can be calculated.
  • the flow rate Q can be calculated by the mathematical formula (5) described above.
  • the error ⁇ of the average flow velocity can be added to the calculation of the flow rate Q, so that the flow rate Q can be calculated with high accuracy.
  • FIG. 7 shows a flow rate error after correcting the relationship between the flow rate ratio and the error ⁇ in the turbulent flow region of FIG. 6 by estimating the error of FIG. 6 using an equation approximated by a quadratic function. That is, FIG. 6 shows the error before correction, and FIG. 7 shows the error after correction.
  • the error shown in FIG. 7 can be reduced to a maximum of 1/100 times the error ⁇ shown in FIG. 6, and according to the present embodiment, the flow rate error can be extremely reduced.
  • the flow rate, the Reynolds number, and the kinematic viscosity are measured as physical quantities of the fluid.
  • both FIG. 2 and FIG. 5 have a block configuration for finally determining the flow rate of the fluid 102.
  • the fluid measuring apparatus 1 of the present embodiment forms a plurality of measurement lines ⁇ , ⁇ , ⁇ by transmitting and receiving ultrasonic waves from a plurality of ultrasonic probes installed in the pipe 100 to the fluid 102 in the pipe 100, and a control unit 60, in the fluid measuring device 1 for obtaining the physical quantity of the fluid 102, the control unit 60 calculates the flow velocity of the fluid 102 measured by a plurality of measurement lines ⁇ , ⁇ , ⁇ , and the flow velocity of the fluid 102.
  • the flow rate ratio calculating unit 43 calculates a flow rate ratio based on the flow rate ratio
  • the physical quantity calculation unit calculates a physical quantity based on the flow rate ratio.
  • the physical quantity calculation unit corresponds to the Reynolds number calculation unit 46, the flow rate calculation unit 50, and the viscosity calculation unit 51 in the embodiment of FIGS.
  • the physical quantity of the fluid 102 can be obtained based on the ratio of the flow rates of the fluid 102, and in particular, the physical quantity can be measured with high accuracy regardless of the laminar flow / turbulent flow. Therefore, it is not necessary to prepare separate fluid measurement devices for laminar flow and turbulent flow, and it is possible to perform highly accurate measurement with a single fluid measurement device.
  • the physical quantity calculation unit is a flow rate calculation unit 50 that calculates at least the flow rate of the fluid 102, and further includes an error calculation unit 44 that calculates an error in the average flow velocity calculated from the flow velocity by the numerical integration method.
  • the flow rate calculation unit 50 preferably calculates the flow rate of the fluid 102 using the average flow velocity and the error obtained by the error calculation unit 44.
  • the embodiment shown in FIGS. 2 and 5 corresponds to this embodiment. Thereby, an error can be taken into account in the flow rate calculation, and in particular, the flow rate can be calculated with high accuracy in a turbulent flow region where the error fluctuation is large.
  • the Reynolds number calculation unit 46 is further provided.
  • the Reynolds number calculation unit 46 calculates the Reynolds number based on the flow rate ratio, and the error calculation unit 44 converts the error into the Reynolds number. It can be set as the structure calculated based on. The embodiment shown in FIG. Thereby, the flow rate can be acquired as the physical quantity together with the Reynolds number.
  • the Reynolds number can be calculated easily and accurately based on the flow rate ratio without requiring piping dimensions and kinematic viscosity that were necessary for the calculation of the Reynolds number.
  • the error calculation unit 44 can calculate an error based on the Reynolds number.
  • the flow rate calculation unit 50 can accurately calculate the flow rate of the fluid 102 using the average flow velocity and the error obtained by the error calculation unit 44.
  • a Reynolds number / error conversion table 48 is further provided, and the error calculation unit 44 uses the Reynolds number obtained from the Reynolds number calculation unit 46 to perform Reynolds number-error conversion. It is preferable to calculate the error based on the table 48.
  • the embodiment shown in FIG. In this way, by providing the Reynolds number-error conversion table 48 in advance, if the Reynolds number is obtained, the error can be calculated quickly, and consequently the flow rate calculation processing time can be shortened.
  • the physical quantity calculation unit is a Reynolds number calculation unit 46 that calculates at least the Reynolds number of the fluid, and the Reynolds number calculation unit 46 preferably calculates the Reynolds number based on the flow rate ratio.
  • the embodiment shown in FIG. 2 and its modifications are applicable.
  • the deformation of FIG. 2 corresponds to a form in which the flow rate of the fluid 102 is calculated in FIG.
  • the Reynolds number can be calculated easily and accurately based on the flow rate ratio without requiring the piping dimensions and kinematic viscosity required for the calculation of the Reynolds number.
  • a conversion table 47 between the flow rate ratio and the Reynolds number is further provided.
  • the Reynolds number calculation unit 46 uses the flow rate ratio acquired from the flow rate ratio calculation unit 43 to use the flow rate ratio ⁇ It is preferable to calculate the Reynolds number based on the Reynolds number conversion table 47.
  • the embodiment shown in FIG. thus, by providing the flow rate ratio-Reynolds number conversion table 47 in advance, the Reynolds number can be calculated quickly and accurately if the flow rate ratio is acquired.
  • a viscosity calculation unit 51 is further provided, and the viscosity calculation unit 51 calculates the kinematic viscosity of the fluid 102 based on the Reynolds number obtained by the Reynolds number calculation unit 46. Is possible. The embodiment shown in FIG. Thus, in this Embodiment, kinematic viscosity can be calculated rapidly and with high precision with Reynolds number.
  • the flow rate ratio / error conversion table 45 is further provided.
  • the error calculation unit 44 uses the flow rate ratio acquired from the flow rate ratio calculation unit 43 to convert the flow rate ratio into the error. Based on the table 45, the error can be calculated.
  • the embodiment shown in FIG. Thereby, an error can be taken into account in the flow rate calculation, and in particular, the flow rate can be calculated with high accuracy in a turbulent flow region where the error fluctuation is large.
  • the error calculation unit 44 can calculate an error based on the flow rate ratio by calculating the flow rate ratio.
  • the flow rate calculation unit 50 can calculate the flow rate of the fluid frequently using the average flow velocity and the error obtained by the error calculation unit 44. In the embodiment of FIG. 5, as shown in FIG. 2, it is possible to calculate the flow rate quickly and accurately based on the flow rate ratio without requiring the calculation of the Reynolds number.
  • the plurality of measurement lines ⁇ , ⁇ , and ⁇ it is possible for the plurality of measurement lines ⁇ , ⁇ , and ⁇ to be parallel to improve the accuracy of numerical integration in obtaining the average flow velocity, which is preferable. It is.
  • the present invention described above is useful for a fluid measurement device for measuring a physical quantity of a fluid, specifically, a flow rate, a Reynolds number, a kinematic viscosity, and the like.

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Abstract

The objective of the present invention is to provide a fluid measuring device with which it is possible to measure easily and accurately a physical quantity relating to a fluid with a higher degree of accuracy than in the past, irrespective of whether flow is laminar or turbulent. A fluid measuring device (1) forms a plurality of traverse lines by transmitting and receiving ultrasonic waves, from a plurality of ultrasonic probes installed in a pipeline (100), into and from a fluid (102) inside the pipeline, and obtains a physical quantity relating to the fluid using a control unit (60). The control unit is configured to include: a flow velocity calculating unit (42) which calculates flow velocities of the fluid, measured using the plurality of traverse lines; a flow velocity ratio calculating unit (43) which calculates a flow velocity ratio on the basis of the flow velocities of the fluid; and a physical quantity calculating unit (Reynolds number calculating unit (46), flow volume calculating unit (50), viscosity calculating unit (51)) which calculates the abovementioned physical quantity on the basis of the flow velocity ratio.

Description

流体計測装置Fluid measuring device
 本発明は、超音波により、配管内の流体の流量やレイノルズ数等の物理量を計測する流体計測装置に関する。 The present invention relates to a fluid measuring apparatus that measures a physical quantity such as a flow rate of a fluid in a pipe and a Reynolds number by ultrasonic waves.
 従来から、配管を流れる流体の流量を計測するにあたり、超音波を利用した流量計測装置が知られている(特許文献1参照)。超音波による流量計測装置では、配管に、複数の超音波送受信部を配置し、交互に超音波の送受信を行って、その伝搬時間の差から流量を検出するものである。 Conventionally, a flow rate measuring device using ultrasonic waves is known for measuring the flow rate of a fluid flowing through a pipe (see Patent Document 1). In an ultrasonic flow measurement device, a plurality of ultrasonic transmission / reception units are arranged in a pipe, and ultrasonic transmission / reception is alternately performed, and a flow rate is detected from a difference in propagation time.
特開昭55-160814号公報JP-A-55-160814
 ところで、流量計測の場合、流体の配管内の流速分布を求めることが必要である。流速分布は、レイノルズ数により変化する。このため、レイノルズ数を求めることが必要となるが、レイノルズ数を求めるには、配管寸法、流体の流速、更には、流体の動粘度が必要である。このうち、流体の流速は、超音波送受信部より得られた信号に基づく測定値を使用できるが、配管寸法と動粘度は、代表値をあらかじめ入力しておく必要があった。特に、動粘度は、流体温度によって変化する。このため、あらかじめ動粘度の温度特性を測定してテーブル等を作成し保存しておかなければならない。そして、別途、温度を測定して正確な動粘度を求める等、複雑な補正をする必要があり、簡単に、流量を計測することができなかった。また、複雑な補正により、精度良く流量を計測することができなかった。 By the way, in the case of flow rate measurement, it is necessary to obtain the flow velocity distribution in the fluid piping. The flow velocity distribution varies depending on the Reynolds number. For this reason, it is necessary to obtain the Reynolds number, but in order to obtain the Reynolds number, the piping dimensions, the flow velocity of the fluid, and the kinematic viscosity of the fluid are necessary. Among these, the flow rate of the fluid can use a measured value based on a signal obtained from the ultrasonic transmission / reception unit, but it is necessary to input representative values in advance for the piping dimensions and kinematic viscosity. In particular, kinematic viscosity varies with fluid temperature. For this reason, the temperature characteristics of kinematic viscosity must be measured in advance and a table or the like must be created and stored. In addition, it is necessary to make complicated corrections such as obtaining the exact kinematic viscosity by measuring the temperature separately, and the flow rate cannot be easily measured. In addition, the flow rate could not be accurately measured due to complicated correction.
 また、従来の流量計測装置にて、流体の流量を計測する際、超音波の測線は、線であるため、配管断面全体の平均流速に対し誤差を生じるという課題があった。 Also, when measuring the flow rate of fluid with a conventional flow rate measuring device, since the ultrasonic measurement line is a line, there is a problem that an error occurs with respect to the average flow velocity of the entire pipe cross section.
 例えば、特許文献1では、ガウス数値積分法を適用して、n点の測線で測定した平均流速の重み付け加算で、配管断面の平均流速を求めている。 For example, in Patent Document 1, the Gaussian numerical integration method is applied, and the average flow velocity of the pipe cross section is obtained by weighted addition of the average flow velocity measured at the n-point survey line.
 しかしながら、流速分布は、例えば、乱流域では1/n乗則で知られるような指数関数で近似されるように高次の項を含む。このため、これにガウス数値積分法を適用すると、積分誤差が発生する。特に、レイノルズ数の小さい層流域からレイノルズ数の大きい乱流域まで広く適用しようとすると、層流域では、放物線であった流速分布が、乱流域では1/n乗の指数関数の形状に大きく変化する。このため、特に乱流域では、レイノルズ数によって誤差が大きく変動し、流体の流量を正確に求めることができない問題があった。 However, the flow velocity distribution includes high-order terms so that it can be approximated by an exponential function known by the 1 / n power law, for example, in a turbulent flow region. For this reason, when the Gaussian numerical integration method is applied to this, an integration error occurs. In particular, when trying to apply widely from a laminar basin with a small Reynolds number to a turbulent region with a large Reynolds number, the flow velocity distribution, which was a parabola in the laminar basin, greatly changes to the shape of an exponential function of 1 / n power in the turbulent region. . For this reason, especially in the turbulent flow region, there is a problem that the error greatly varies depending on the Reynolds number, and the flow rate of the fluid cannot be obtained accurately.
 このため、従来では、精度保証をレイノルズ数で限定し、乱流域、或いは層流域のみとする必要があった。しかしながら、精度保証を、乱流域か層流域かで限定すると、例えば、動粘度が小さい水には、乱流用の流量計を適用し、例えば、動粘度が大きい油には、層流用の流量計を適用するように、流量計を2種類用意する必要がある。また、レイノルズ数は、流速や動粘度で変化するので、流速が低い場合は層流だが、流速が高くなると乱流になる場合や、低温では動粘度が大きく層流だが、高温になると動粘度が小さくなり乱流になる場合では、層流域から乱流域まで、精度良く計測できないといった課題があった。 For this reason, conventionally, it has been necessary to limit the accuracy guarantee to the Reynolds number and to use only a turbulent flow region or a laminar flow region. However, if the accuracy guarantee is limited to a turbulent flow region or a laminar flow region, for example, a turbulent flow meter is applied to water having a small kinematic viscosity, and a laminar flow meter is applied to an oil having a large kinematic viscosity, for example. It is necessary to prepare two types of flow meters so that The Reynolds number varies with the flow velocity and kinematic viscosity, so it is laminar when the flow velocity is low, but it becomes turbulent when the flow velocity is high, or it is laminar with a large kinematic viscosity at low temperatures. In the case where becomes smaller and becomes turbulent, there is a problem that accurate measurement cannot be performed from the laminar flow region to the turbulent flow region.
 本発明は、このような問題に鑑みてなされたもので、その目的とするところは、従来に比べて、層流・乱流にかかわらず、高精度に、流体の物理量を計測することができる流体計測装置を提供することである。 The present invention has been made in view of such problems, and the object of the present invention is to measure the physical quantity of fluid with higher accuracy than conventional methods regardless of laminar flow and turbulent flow. It is to provide a fluid measuring device.
 本発明の流体計測装置は、配管に設置した複数の超音波送受信部から前記配管内の流体へ超音波を送受信することにより複数の測線を形成し、制御部にて、前記流体の物理量を求める流体計測装置において、前記制御部は、前記複数の測線で計測した前記流体の流速を演算する流速演算部と、前記流体の流速に基づいて、流速比を演算する流速比演算部と、前記流速比に基づいて、前記物理量を演算する物理量演算部と、を有することを特徴とする。 The fluid measuring device of the present invention forms a plurality of measurement lines by transmitting and receiving ultrasonic waves from a plurality of ultrasonic transmission / reception units installed in a pipe to the fluid in the pipe, and the control unit obtains a physical quantity of the fluid. In the fluid measurement device, the control unit calculates a flow rate of the fluid measured along the plurality of survey lines, a flow rate ratio calculation unit that calculates a flow rate ratio based on the flow rate of the fluid, and the flow rate A physical quantity computing unit that computes the physical quantity based on the ratio.
 この構成により、層流・乱流にかかわらず、高精度に、流体の物理量を計測することができる。 This configuration makes it possible to measure the physical quantity of fluid with high accuracy regardless of laminar or turbulent flow.
 本発明の流体計測装置によれば、流体の流速比を求め、流速比に基づいて、流体の物理量を演算する。これにより、層流・乱流にかかわらず、高精度に、流体の物理量を計測できる。 According to the fluid measuring device of the present invention, the flow rate ratio of the fluid is obtained, and the physical quantity of the fluid is calculated based on the flow rate ratio. Thereby, the physical quantity of fluid can be measured with high accuracy regardless of laminar flow or turbulent flow.
本実施の形態の流体計測装置を構成する超音波プローブの配管への配置を示す正面図である。It is a front view which shows arrangement | positioning to piping of the ultrasonic probe which comprises the fluid measuring device of this Embodiment. 第1の実施の形態の流体計測装置のブロック図である(なお、図1に示すA―Aに沿って切断し矢印方向から見た配管、及び、超音波プローブの部分断面図を含む)。FIG. 2 is a block diagram of the fluid measuring device according to the first embodiment (including a pipe cut along the line AA shown in FIG. 1 and viewed from the arrow direction, and a partial cross-sectional view of the ultrasonic probe). 流体の流速比と、レイノルズ(Re)数との相関を表したグラフである。It is a graph showing the correlation between the flow rate ratio of fluid and the Reynolds (Re) number. レイノルズ(Re)数と、誤差εとの相関を表したグラフである。It is a graph showing the correlation between the Reynolds (Re) number and the error ε. 第2の実施の形態の流体計測装置のブロック図である(なお、図1に示すA―Aに沿って切断し矢印方向から見た配管、及び、超音波プローブの部分断面図を含む)。FIG. 5 is a block diagram of a fluid measuring device according to a second embodiment (including a pipe cut along line AA shown in FIG. 1 and viewed from the direction of an arrow, and a partial sectional view of an ultrasonic probe). 流速比と、誤差εとの相関を表したグラフである。It is a graph showing the correlation between the flow rate ratio and the error ε. 図6の誤差を補正した後の、流速比と、誤差εとの相関を表したグラフである。FIG. 7 is a graph showing a correlation between a flow rate ratio and an error ε after correcting the error of FIG. 6.
 以下、本実施の形態に係る流体計測装置について詳細に説明する。なお、以下の説明では、すべての図面において同様な構成要素には同様の符号を付し、適宜説明を省略する。 Hereinafter, the fluid measuring apparatus according to the present embodiment will be described in detail. In the following description, the same components are denoted by the same reference symbols in all the drawings, and the description thereof is omitted as appropriate.
 図1は、本実施の形態の流体計測装置を構成する超音波プローブの配管への配置を示す正面図である。 FIG. 1 is a front view showing an arrangement of ultrasonic probes constituting the fluid measuring device of the present embodiment on a pipe.
 図1に示す実施の形態では、配管100は円筒形状であり、配管100には、3組の超音波プローブ(超音波送受信部)が配置されている。すなわち、図1に示す超音波プローブ10aと、超音波プローブ10bとが組とされ、超音波プローブ13aと、超音波プローブ13bとが組とされ、超音波プローブ14aと、超音波プローブ14bとが組とされている。 In the embodiment shown in FIG. 1, the pipe 100 has a cylindrical shape, and three sets of ultrasonic probes (ultrasonic wave transmission / reception units) are arranged in the pipe 100. That is, the ultrasonic probe 10a and the ultrasonic probe 10b shown in FIG. 1 are combined, the ultrasonic probe 13a and the ultrasonic probe 13b are combined, and the ultrasonic probe 14a and the ultrasonic probe 14b are combined. It is a pair.
 これら各組の超音波プローブ間で送受信された超音波の3つの測線α、測線β、及び、測線γは、夫々平行である。このうち、測線αは、配管100の中心を通って配管100を横断し、測線βと、測線γとは、測線αを挟んで対称位置にある。また、Rは、配管100の内半径を示し、rは、測線αと測線βとの間の距離、及び、測線αと測線γとの間の距離を示す。なお、測線位置r/Rは、ガウス数値積分法等の適用する数値積分法に基づいて適宜決定することができる。 The three measurement lines α, the measurement line β, and the measurement line γ of the ultrasonic waves transmitted and received between each set of ultrasonic probes are parallel to each other. Among these, the measurement line α crosses the pipe 100 through the center of the pipe 100, and the measurement line β and the measurement line γ are in symmetrical positions with the measurement line α in between. R represents the inner radius of the pipe 100, and r represents the distance between the measurement line α and the measurement line β, and the distance between the measurement line α and the measurement line γ. The survey line position r / R can be appropriately determined based on a numerical integration method such as a Gaussian numerical integration method.
 なお、配管100は、円筒形状に限定されるものではなく、測線数も複数であれば3測線でなくても良い。また、測線αは、配管100の中心を通らなくても良いし、測線βと測線γが測線αを挟んで対称であることにも限定されない。なお、各測線α、β、γは、夫々平行であることに限定されるものでないが、各測線α、β、γを平行とすることで、平均流速を求めるうえでの数値積分の精度を向上させることができる。 The pipe 100 is not limited to a cylindrical shape, and may not be three survey lines if the number of survey lines is plural. Further, the measurement line α may not pass through the center of the pipe 100, and the measurement line β and the measurement line γ are not limited to being symmetrical with respect to the measurement line α. Each of the survey lines α, β, γ is not limited to being parallel, but by making each of the survey lines α, β, γ parallel, the accuracy of numerical integration for obtaining the average flow velocity is improved. Can be improved.
 図2は、第1の実施の形態の流体計測装置1のブロック図である。なお、図2は、図1に示すA―Aに沿って切断し矢印方向から見た配管100、及び、超音波プローブ10a、10bの部分断面図も含む。 FIG. 2 is a block diagram of the fluid measuring apparatus 1 according to the first embodiment. 2 also includes a partial cross-sectional view of the pipe 100 and the ultrasonic probes 10a and 10b cut along the line AA shown in FIG. 1 and viewed from the arrow direction.
 図2に示すように、本実施の形態の流体計測装置1は、配管100に設置した複数の超音波プローブ10a、10b、13a、13b、14a、14b(ただし、図2では、超音波プローブ10a、10bのみを図示)と、流体102の物理量を演算する制御部60と、を有して構成される。 As shown in FIG. 2, the fluid measuring apparatus 1 according to the present embodiment includes a plurality of ultrasonic probes 10a, 10b, 13a, 13b, 14a, 14b installed in a pipe 100 (however, in FIG. 2, the ultrasonic probe 10a). 10b only) and a control unit 60 for calculating the physical quantity of the fluid 102.
 図2の部分断面図に示すように、配管100の外面101a、101bに、超音波プローブ10a、10bが配置されている。なお、図2において、図示を省略した超音波プローブ13a、13b、14a、14bに関しては、超音波プローブ10a、10bと配置が異なるだけで以下と同様の構成であるため、説明を省略する。 2, ultrasonic probes 10a and 10b are arranged on the outer surfaces 101a and 101b of the pipe 100 as shown in the partial cross-sectional view of FIG. In FIG. 2, the ultrasonic probes 13a, 13b, 14a, and 14b that are not shown are the same as those described below except for the arrangement of the ultrasonic probes 10a and 10b.
 図2に示すように、超音波プローブ10aは、配管100内の流体102の流れに対して上流側に配置され、超音波プローブ10bは、流体102の流れに対して下流側に配置されている。超音波プローブ10aは、超音波振動子11aと楔12aを有して構成され、超音波プローブ10bは、超音波振動子11bと楔12bを有して構成されている。図2に示すように、各超音波振動子11a、11bは、流体102の流れ方向に対して斜めに傾斜して配置されている。 As shown in FIG. 2, the ultrasonic probe 10 a is arranged on the upstream side with respect to the flow of the fluid 102 in the pipe 100, and the ultrasonic probe 10 b is arranged on the downstream side with respect to the flow of the fluid 102. . The ultrasonic probe 10a is configured to include an ultrasonic transducer 11a and a wedge 12a, and the ultrasonic probe 10b is configured to include an ultrasonic transducer 11b and a wedge 12b. As shown in FIG. 2, the ultrasonic transducers 11 a and 11 b are disposed obliquely with respect to the flow direction of the fluid 102.
 図2に示すように、各超音波振動子11a、11bは、夫々スイッチ33a、33bに接続されている。なお、図1に示した超音波プローブ13a、13bは、図2に示す各スイッチ34a、34bに電気的に接続され、図1に示した超音波プローブ14a、14bは、図2に示す各スイッチ35a、35bに電気的に接続される。 As shown in FIG. 2, each ultrasonic transducer 11a, 11b is connected to a switch 33a, 33b, respectively. The ultrasonic probes 13a and 13b shown in FIG. 1 are electrically connected to the switches 34a and 34b shown in FIG. 2, and the ultrasonic probes 14a and 14b shown in FIG. It is electrically connected to 35a, 35b.
 続いて、制御部60について説明する。図2に示すように、制御部60は、送信部31、受信部32、時間計測部40、スイッチ切替部41、流速演算部42、流速比演算部43、レイノルズ数演算部46、流速比―レイノルズ数変換テーブル47、誤差演算部44、レイノルズ数―誤差変換テーブル48、流量演算部50、及び、粘度演算部51を有して構成される。 Subsequently, the control unit 60 will be described. As shown in FIG. 2, the control unit 60 includes a transmission unit 31, a reception unit 32, a time measurement unit 40, a switch switching unit 41, a flow rate calculation unit 42, a flow rate ratio calculation unit 43, a Reynolds number calculation unit 46, a flow rate ratio − The Reynolds number conversion table 47, the error calculation unit 44, the Reynolds number-error conversion table 48, the flow rate calculation unit 50, and the viscosity calculation unit 51 are configured.
 送信部31は、各スイッチ33a、33b、34a、34b、35a、35bに電気的に接続される。送信部31では、スイッチに電気的に接続された超音波振動子に電気信号を送信し、超音波を発生させる。 The transmission unit 31 is electrically connected to each switch 33a, 33b, 34a, 34b, 35a, 35b. The transmission unit 31 transmits an electrical signal to an ultrasonic transducer that is electrically connected to the switch to generate an ultrasonic wave.
 受信部32は、各スイッチ33a、33b、34a、34b、35a、35bに電気的に接続される。受信部32では、スイッチに電気的に接続された超音波振動子からの電気信号を受信する。 The receiving unit 32 is electrically connected to the switches 33a, 33b, 34a, 34b, 35a, and 35b. The receiving unit 32 receives an electrical signal from an ultrasonic transducer that is electrically connected to the switch.
 時間計測部40は、送信部31、及び、受信部32に電気的に接続される。時間計測部40では、各測線α、β、γ(図1参照)における超音波の送信から受信までの伝搬時間を計測する。 The time measurement unit 40 is electrically connected to the transmission unit 31 and the reception unit 32. The time measuring unit 40 measures the propagation time from transmission to reception of ultrasonic waves on each of the measurement lines α, β, and γ (see FIG. 1).
 流速演算部42は、時間計測部40と電気的に接続される。流速演算部42では、時間計測部40から送信された伝搬時間に基づいて、流体102の各測線α、β、γの流速を演算する。また、流速演算部42では、配管断面全体の平均流速を、例えば、ガウス数値積分法により、各測線α、β、γに重み付け加算して演算する。 The flow velocity calculation unit 42 is electrically connected to the time measurement unit 40. The flow velocity calculation unit 42 calculates the flow velocity of each of the measurement lines α, β, and γ of the fluid 102 based on the propagation time transmitted from the time measurement unit 40. Further, the flow velocity calculation unit 42 calculates the average flow velocity of the entire pipe cross section by weighting and adding to each of the survey lines α, β, γ by, for example, the Gaussian numerical integration method.
 流速比演算部43は、流速演算部42と電気的に接続される。流速比演算部43では、流速演算部42で得られた各測線α、β、γの流速に基づいて、流速比を演算する。 The flow rate ratio calculation unit 43 is electrically connected to the flow rate calculation unit 42. The flow rate ratio calculation unit 43 calculates the flow rate ratio based on the flow rates of the respective survey lines α, β, and γ obtained by the flow rate calculation unit 42.
 レイノルズ数演算部46は、流速比演算部43と電気的に接続されている。レイノルズ数演算部46では、流速比に基づいて、レイノルズ(Re)数を演算する。 The Reynolds number calculation unit 46 is electrically connected to the flow rate ratio calculation unit 43. The Reynolds number calculator 46 calculates the Reynolds (Re) number based on the flow rate ratio.
 流速比-レイノルズ数変換テーブル47は、レイノルズ数演算部46に電気的に接続される。流速比-レイノルズ数変換テーブル47は、レイノルズ数、及び、流量を演算するにあたって、予め用意されている。流速比-レイノルズ数変換テーブル47では、流速比と、レイノルズ数とが相関づけられている。そして、レイノルズ数演算部46では、流速比に基づいて、流速比-レイノルズ数変換テーブル47からレイノルズ数を演算する。 The flow rate ratio / Reynolds number conversion table 47 is electrically connected to the Reynolds number calculation unit 46. The flow rate ratio-Reynolds number conversion table 47 is prepared in advance for calculating the Reynolds number and the flow rate. In the flow rate ratio-Reynolds number conversion table 47, the flow rate ratio and the Reynolds number are correlated. The Reynolds number calculation unit 46 calculates the Reynolds number from the flow rate ratio-Reynolds number conversion table 47 based on the flow rate ratio.
 誤差演算部44は、レイノルズ数演算部46と電気的に接続される。誤差演算部44では、流速演算部42にて得られた平均流速の誤差(積分誤差)を求める。この誤差を、図2に示す実施の形態では、レイノルズ数と誤差との関係から求めている。 The error calculation unit 44 is electrically connected to the Reynolds number calculation unit 46. The error calculation unit 44 obtains an error (integration error) of the average flow velocity obtained by the flow velocity calculation unit 42. In the embodiment shown in FIG. 2, this error is obtained from the relationship between the Reynolds number and the error.
 レイノルズ数-誤差変換テーブル48は、誤差演算部44に電気的に接続される。レイノルズ数-誤差変換テーブル48は、流量を演算するにあたって予め用意されている。レイノルズ数-誤差変換テーブル48では、レイノルズ数と、誤差とが相関づけられている。そして、誤差演算部44では、レイノルズ数演算部46より取得されたレイノルズ数に基づいて、レイノルズ数-誤差変換テーブル48から誤差を演算する。 The Reynolds number-error conversion table 48 is electrically connected to the error calculation unit 44. The Reynolds number-error conversion table 48 is prepared in advance for calculating the flow rate. In the Reynolds number-error conversion table 48, the Reynolds number and the error are correlated. Then, the error calculator 44 calculates an error from the Reynolds number-error conversion table 48 based on the Reynolds number acquired from the Reynolds number calculator 46.
 流量演算部50は、流速演算部42、及び、誤差演算部44と電気的に接続される。流量演算部50では、平均流速、及び、誤差に基づいて流量を演算する。 The flow rate calculation unit 50 is electrically connected to the flow rate calculation unit 42 and the error calculation unit 44. The flow rate calculation unit 50 calculates the flow rate based on the average flow velocity and the error.
 次に、図2に示すブロック図を用いて、時間計測から流量演算に至るまでの各種演算処理の流れについて説明する。 Next, the flow of various calculation processes from time measurement to flow rate calculation will be described using the block diagram shown in FIG.
 図2に示すように、スイッチ切替部41からの信号により、送信部31とスイッチ33aとを電気的に接続する。これにより、超音波振動子11aと、送信部31とが、スイッチ33aを介して電気的に接続される。また、スイッチ切替部41からの信号により、受信部32とスイッチ33bとを電気的に接続する。これにより、超音波振動子11bと、受信部32とが、スイッチ33bを介して電気的に接続される。 As shown in FIG. 2, the transmission unit 31 and the switch 33a are electrically connected by a signal from the switch switching unit 41. Thereby, the ultrasonic transducer | vibrator 11a and the transmission part 31 are electrically connected via the switch 33a. Further, the receiving unit 32 and the switch 33b are electrically connected by a signal from the switch switching unit 41. Thereby, the ultrasonic transducer | vibrator 11b and the receiving part 32 are electrically connected via the switch 33b.
 このとき、送信部31では、超音波振動子11aに対し、電気信号を送信し超音波を発生させる。発生した超音波は、楔12aを透過し、配管100内の流体102に入射される。配管100内の流体102に入射された超音波は、流体102の上流側から下流側に向かって、流体102内を入射角θで伝搬する。超音波プローブ10bに伝搬した超音波は、超音波振動子11bで電気信号に変換される。この電気信号は、スイッチ33bを介して、受信部32で受信される。 At this time, the transmission unit 31 transmits an electrical signal to the ultrasonic transducer 11a to generate an ultrasonic wave. The generated ultrasonic wave passes through the wedge 12 a and enters the fluid 102 in the pipe 100. The ultrasonic wave incident on the fluid 102 in the pipe 100 propagates in the fluid 102 at an incident angle θ from the upstream side to the downstream side of the fluid 102. The ultrasonic wave propagated to the ultrasonic probe 10b is converted into an electric signal by the ultrasonic transducer 11b. This electrical signal is received by the receiving unit 32 via the switch 33b.
 このとき、時間計測部40では、超音波の送信から受信までの伝搬時間を計測する。流体102の流れに沿った伝搬時間をTfとする。 At this time, the time measuring unit 40 measures the propagation time from transmission to reception of ultrasonic waves. The propagation time along the flow of the fluid 102 is Tf.
 続いて、スイッチ切替部41からの信号により、スイッチ33aと、スイッチ33bとを、夫々切り替える(スイッチ33aと、スイッチ33bに点線で示した。後述の図5においても同様)。これにより、超音波振動子11aと、受信部32とが、スイッチ33aを介して電気的に接続され、超音波振動子11bと、送信部31とが、スイッチ33bを介して接続される。このとき、超音波は、下流側の超音波振動子11bから上流側の超音波振動子11aに向かって伝搬される。そして、超音波プローブ10aにまで伝搬した超音波は、超音波振動子11aで電気信号に変換される。この電気信号は、スイッチ33aを介して、受信部32で受信される。 Subsequently, the switch 33a and the switch 33b are respectively switched by a signal from the switch switching unit 41 (shown by dotted lines in the switch 33a and the switch 33b. The same applies to FIG. 5 described later). Thereby, the ultrasonic transducer | vibrator 11a and the receiving part 32 are electrically connected via the switch 33a, and the ultrasonic transducer | vibrator 11b and the transmission part 31 are connected via the switch 33b. At this time, the ultrasonic waves propagate from the downstream ultrasonic transducer 11b toward the upstream ultrasonic transducer 11a. Then, the ultrasonic wave propagated to the ultrasonic probe 10a is converted into an electric signal by the ultrasonic transducer 11a. This electric signal is received by the receiving unit 32 via the switch 33a.
 このとき、時間計測部40では、流体102の流れに逆らった超音波の伝搬時間をTrとして計測する。 At this time, the time measuring unit 40 measures the propagation time of the ultrasonic wave against the flow of the fluid 102 as Tr.
 これにより、図1に示す測線αの伝搬時間Tf、Trを取得することができる。ここで、超音波の伝搬時間は、流体102の流れの影響を受けて、Tfは短く、Trは長くなる。TfとTrの差は、流体102の流速に応じて変化するので、この差を測定することにより、流体102の測線上の平均流速を計測することができる。 Thereby, the propagation times Tf and Tr of the survey line α shown in FIG. 1 can be acquired. Here, the propagation time of the ultrasonic waves is affected by the flow of the fluid 102, so that Tf is short and Tr is long. Since the difference between Tf and Tr changes according to the flow velocity of the fluid 102, the average flow velocity on the measurement line of the fluid 102 can be measured by measuring this difference.
 図1に示すように、本実施の形態では、測線α、β、γが3つある。したがって、スイッチ切替部41からの信号により、各スイッチ34a、34b、35a、35bを、送信と受信との間で切り替えて、測線β、γの伝搬時間Tf、Trも上記と同様の方法で取得する。 As shown in FIG. 1, in this embodiment, there are three survey lines α, β, and γ. Therefore, each switch 34a, 34b, 35a, 35b is switched between transmission and reception by a signal from the switch switching unit 41, and the propagation times Tf, Tr of the survey lines β, γ are obtained in the same manner as described above. To do.
 各測線α、β、γの伝搬時間Tf、Trは、時間計測部40から流速演算部42に送信される。そして、流速演算部42では、伝搬時間Tf、Trから、流体102の流速Vを演算する。伝搬時間Tf、Trは、以下の数式(1)、(2)より表される。 The propagation times Tf and Tr of the measurement lines α, β, and γ are transmitted from the time measurement unit 40 to the flow velocity calculation unit 42. Then, the flow velocity calculation unit 42 calculates the flow velocity V of the fluid 102 from the propagation times Tf and Tr. The propagation times Tf and Tr are expressed by the following mathematical formulas (1) and (2).
 Tf=L/(C+Vcosθ)              (1)
 Tr=L/(C-Vcosθ)              (2)
 ここで、Cは、流体102の音速、θは、入射角及び、Lは、流体102の中を超音波が伝搬する伝搬路長である。
Tf = L / (C + V cos θ) (1)
Tr = L / (C−Vcos θ) (2)
Here, C is the speed of sound of the fluid 102, θ is the incident angle, and L is the propagation path length through which the ultrasonic wave propagates in the fluid 102.
 各数式(1)、(2)から、流速Vを、以下の数式(3)より表すことができる。
 V=L/2cosθ×((1/Tf)-(1/Tr))   (3)
From each formula (1) and (2), the flow velocity V can be expressed by the following formula (3).
V = L / 2 cos θ × ((1 / Tf) − (1 / Tr)) (3)
 各測線α、β、γの流速Vについて各々演算し、得られた流速値を、それぞれv1、v2、v3とする。 Calculating the flow velocity V of each survey line α, β, γ, respectively, and let the obtained flow velocity values be v1, v2, v3, respectively.
 また、流速演算部42では、例えば、ガウス数値積分法に基づいて、配管断面全体の平均流速を、各測線α、β、γに重み付けして求める。ガウス数値積分法とは、(2n-1)次の多項式の積分は、n点の重み付け加算で求められるという数値積分法の一つである。すなわち、n点の測線で測定した平均流速の重み付け加算で、配管断面全体の平均流速を得ることができる。この平均流速は、レイノルズ数によらず求めることができる。 Further, the flow velocity calculation unit 42 obtains the average flow velocity of the entire pipe cross section by weighting each of the survey lines α, β, γ, for example, based on the Gaussian numerical integration method. The Gaussian numerical integration method is one of the numerical integration methods in which the integration of the (2n-1) degree polynomial is obtained by weighted addition of n points. That is, the average flow velocity of the entire pipe cross section can be obtained by weighted addition of the average flow velocity measured at the n-point survey line. This average flow velocity can be determined regardless of the Reynolds number.
 平均流速は、w1・v1+w2・v2+w3・v3の積分値で、求めることができる。ここで、w1、w2、及び、w3は、流速値v1、v2、v3の夫々に対する重み付け加算値であり、重み付け加算値w1、w2、及び、w3は、規定値である。例えば、本実施の形態では、3測線(n=3)である。3測線である場合、配管100の中心を通る測線αは、測線位置r/R=0であり、測線β、γは、測線位置r/R=0.7746(小数点第5位を四捨五入)となるよう調整される。そして、ガウス数値積分法によれば、測線α(すなわち、流速値v1)の重み付け加算値は、0.4444444(小数点第8位を四捨五入)である。また、測線β、γ(すなわち、流速値v2、v3)の重み付け加算値は、0.2777778(小数点第8位を四捨五入)である。このような、測線位置(分点)と重み付け加算値との関係は、一般的に知られている。測線位置(分点)と重み付け加算値との関係は、適用する数値積分法により決定することができる。本実施の形態では、ガウス数値積分法を代表して用いるが、数値積分法としては、ガウス数値積分法以外に、チェビシェフ積分法や、ロバット積分法を用いることができる。 The average flow velocity can be obtained as an integral value of w1 · v1 + w2 · v2 + w3 · v3. Here, w1, w2, and w3 are weighted addition values for the flow velocity values v1, v2, and v3, respectively, and the weighted addition values w1, w2, and w3 are specified values. For example, in this embodiment, there are 3 survey lines (n = 3). When there are three survey lines, the survey line α passing through the center of the pipe 100 is the survey line position r / R = 0, and the survey lines β and γ are the survey line position r / R = 0.7746 (rounded to the fifth decimal place). It is adjusted to become. Then, according to the Gaussian numerical integration method, the weighted addition value of the survey line α (that is, the flow velocity value v1) is 0.4444444 (rounded to the eighth decimal place). Further, the weighted addition value of the measurement lines β and γ (that is, the flow velocity values v2 and v3) is 0.2777778 (rounded to the eighth decimal place). Such a relationship between the survey line position (minute point) and the weighted addition value is generally known. The relationship between the survey line position (minute point) and the weighted addition value can be determined by a numerical integration method to be applied. In this embodiment, the Gaussian numerical integration method is representatively used. However, as the numerical integration method, a Chebyshev integration method or a Lobat integration method can be used in addition to the Gaussian numerical integration method.
 数値積分法では、通常の積分法のように、面積を求める際に、面積内を短冊状に分けて各短冊面積を全て加算するものでなく、特定箇所に重み付け加算を行うものである。そして、数値積分法を、本実施の形態の流体計測装置に適用すると、特定箇所の測線の流速を重み付け加算することで、配管断面全体の平均流速を求めることができる。ただし、数値積分法では、特に、流体102の乱流域において、積分誤差変動が大きくなる。そこで、本実施の形態では、流速比、或いは流速比と相関関係のあるレイノルズ数と、誤差(積分誤差)との関係を見出し、流速比やレイノルズ数から誤差を推定することを可能とした。誤差の具体的な求め方に関しては後述する。 In the numerical integration method, as in the normal integration method, when obtaining the area, the area is not divided into strips and all the strip areas are added, but weighted addition is performed at a specific location. When the numerical integration method is applied to the fluid measurement device of the present embodiment, the average flow velocity of the entire pipe cross section can be obtained by weighted addition of the flow velocity of the survey line at a specific location. However, in the numerical integration method, especially in the turbulent region of the fluid 102, the integration error fluctuation becomes large. Thus, in the present embodiment, the relationship between the flow rate ratio or the Reynolds number correlated with the flow rate ratio and the error (integration error) is found, and the error can be estimated from the flow rate ratio and the Reynolds number. A specific method for obtaining the error will be described later.
 次に、流速演算部42で求められた各測線α、β、γの流速値v1、v2、v3が、流速比演算部43に送られる。そして、流速比演算部43では、流速値v1、v2、v3により流速比Vrを演算する。 Next, the flow velocity values v 1, v 2, v 3 of the respective measurement lines α, β, γ obtained by the flow velocity calculation unit 42 are sent to the flow velocity ratio calculation unit 43. The flow rate ratio calculation unit 43 calculates the flow rate ratio Vr from the flow rate values v1, v2, and v3.
 図1に示す実施の形態では、測線αが、配管100の中心を通り、測線βと測線γは、測線αに対して左右対称に位置している。このような構成では、例えば、以下の数式(4)で、流速比を演算することができる。
 Vr=2×v2/(v1+v3)        (4)
In the embodiment shown in FIG. 1, the measurement line α passes through the center of the pipe 100, and the measurement line β and the measurement line γ are located symmetrically with respect to the measurement line α. In such a configuration, for example, the flow rate ratio can be calculated by the following mathematical formula (4).
Vr = 2 × v2 / (v1 + v3) (4)
 続いて、レイノルズ数演算部46では、流速比演算部43より得られた流速比に基づいて、レイノルズ(Re)数を演算する。本実施の形態では、流速比Vrとレイノルズ数との関係を予め、シミュレーション等で導き出している。そして、シミュレーション結果は、流速比-レイノルズ数変換テーブル47として、流体計測装置1の制御部60内に記憶されている。そして、流速比演算部43より得られた流速比Vrを用いて、流速比-レイノルズ数変換テーブル47からレイノルズ(Re)数を演算することができる。 Subsequently, the Reynolds number calculator 46 calculates the Reynolds (Re) number based on the flow rate ratio obtained from the flow rate ratio calculator 43. In the present embodiment, the relationship between the flow rate ratio Vr and the Reynolds number is derived in advance by simulation or the like. The simulation result is stored in the control unit 60 of the fluid measuring apparatus 1 as a flow rate ratio-Reynolds number conversion table 47. The Reynolds (Re) number can be calculated from the flow rate ratio-Reynolds number conversion table 47 using the flow rate ratio Vr obtained from the flow rate ratio calculation unit 43.
 図3は、流体の流速比と、レイノルズ(Re)数との相関を表したグラフである。図3に示す相関関係は、乱流の流速分布の近似式として、1/n乗則(具体的には1/7乗則)を用い、層流の流速分布として放物線を用いて数値解析して得ることができる。図3によれば、流速比Vrに対してレイノルズ(Re)数は、ほぼ単調に減少している。また、図3の実線で示した乱流域においては、流速比Vrに対応するレイノルズ数は1つしかなく、レイノルズ数を一意に求めることができる。なお、図4、図6、図7においても同様に、乱流域を実線で示した。なお、層流での流速比Vrは、一定値とされる。層流域では、流速比からレイノルズ数は特定できないが、後述するように層流域で発生する誤差は一定値なので、誤差を補正することはできる。また、図3に示す点線は、層流と乱流との間の遷移領域を示している。図4、図6、図7においても同様に、層流は、一定値であり、また遷移領域を点線で示した。 FIG. 3 is a graph showing the correlation between the fluid flow rate ratio and the Reynolds (Re) number. The correlation shown in FIG. 3 is numerically analyzed using a 1 / n power law (specifically, a 1/7 power law) as an approximate expression of the turbulent flow velocity distribution and a parabola as a laminar flow velocity distribution. Can be obtained. According to FIG. 3, the Reynolds (Re) number decreases substantially monotonically with respect to the flow rate ratio Vr. Further, in the turbulent flow region shown by the solid line in FIG. 3, there is only one Reynolds number corresponding to the flow velocity ratio Vr, and the Reynolds number can be uniquely obtained. 4, 6, and 7, similarly, the turbulent flow region is indicated by a solid line. The flow rate ratio Vr in the laminar flow is a constant value. In the laminar basin, the Reynolds number cannot be specified from the flow rate ratio, but the error occurring in the laminar basin is a constant value as will be described later, and therefore the error can be corrected. Moreover, the dotted line shown in FIG. 3 has shown the transition area | region between a laminar flow and a turbulent flow. Similarly, in FIGS. 4, 6, and 7, the laminar flow has a constant value, and the transition region is indicated by a dotted line.
 図2に示す流速比―レイノルズ数変換テーブル47は、図3に示すグラフに基づいた変換テーブルを構成している。よって、流速比演算部43から得られた流速比Vrを用いて、流速比―レイノルズ数変換テーブル47からレイノルズ(Re)数を演算することができる。 The flow rate ratio-Reynolds number conversion table 47 shown in FIG. 2 constitutes a conversion table based on the graph shown in FIG. Therefore, the Reynolds (Re) number can be calculated from the flow rate ratio-Reynolds number conversion table 47 using the flow rate ratio Vr obtained from the flow rate ratio calculation unit 43.
 続いて、図2に示す誤差演算部44では、レイノルズ数演算部46で取得されたレイノルズ数に基づいて、誤差εを演算する。ここで、誤差εは、ガウス数値積分法等の数値積分法で求めた平均流速に対する積分誤差に相当する。 Subsequently, the error calculation unit 44 shown in FIG. 2 calculates the error ε based on the Reynolds number acquired by the Reynolds number calculation unit 46. Here, the error ε corresponds to an integration error with respect to the average flow velocity obtained by a numerical integration method such as a Gaussian numerical integration method.
 図2に示すように、レイノルズ数と誤差εとの相関関係は、予め、レイノルズ数―誤差変換テーブル48に用意されている。レイノルズ数と誤差εとの関係を予め、シミュレーションして導き出している。そのシミュレーション結果は、レイノルズ数―誤差変換テーブル48として、流体計測装置1の制御部60内に記憶されている。そして、レイノルズ数演算部46より得られたレイノルズ数を用いて、レイノルズ数―誤差変換テーブル48から誤差εを演算することができる。 As shown in FIG. 2, the correlation between the Reynolds number and the error ε is prepared in advance in the Reynolds number-error conversion table 48. The relationship between the Reynolds number and the error ε is derived by simulation in advance. The simulation result is stored as a Reynolds number-error conversion table 48 in the control unit 60 of the fluid measuring apparatus 1. The error ε can be calculated from the Reynolds number-error conversion table 48 using the Reynolds number obtained from the Reynolds number calculation unit 46.
 図4は、レイノルズ(Re)数と、誤差εとの相関を表したグラフである。図4では、数値積分法を用いて重み付け加算して求めた流量測定値の誤差との相関を示している。図4に示すように、乱流域では、レイノルズ数により、誤差εの変動が大きいことがわかる。層流域では誤差εは一定値となる。図3において、層流域ではレイノルズ数を特定できないと前述したが、層流域であることは判るので、誤差εを求めることができる。 FIG. 4 is a graph showing the correlation between the Reynolds (Re) number and the error ε. FIG. 4 shows the correlation with the error of the flow rate measurement value obtained by weighted addition using the numerical integration method. As shown in FIG. 4, it can be seen that in the turbulent flow region, the variation of the error ε is large due to the Reynolds number. In the laminar basin, the error ε is a constant value. In FIG. 3, it has been described that the Reynolds number cannot be specified in the laminar basin. However, since it is understood that the laminar basin is present, the error ε can be obtained.
 図2に示すレイノルズ数-誤差変換テーブル48は、図4に示すグラフに基づいた変換テーブルを構成している。よって、レイノルズ数演算部46から得られたレイノルズ数を用いて、レイノルズ数-誤差変換テーブル48から誤差εを演算することができる。 The Reynolds number-error conversion table 48 shown in FIG. 2 constitutes a conversion table based on the graph shown in FIG. Therefore, the error ε can be calculated from the Reynolds number-error conversion table 48 using the Reynolds number obtained from the Reynolds number calculation unit 46.
 続いて、図2に示す流量演算部50にて、以下の数式(5)により流量Qを演算する。 Subsequently, the flow rate calculation unit 50 shown in FIG. 2 calculates the flow rate Q by the following formula (5).
 Q=A×(w1・v1+w2・v2+w3・v3)×(100/(100+ε))   (5)
 ここで、Aは、配管100の断面積であり、配管100の内径D(内半径R×2)を用いて、以下の数式(6)で表される。
 A=(D/2)×π                  (6)
Q = A × (w1 · v1 + w2 · v2 + w3 · v3) × (100 / (100 + ε)) (5)
Here, A is a cross-sectional area of the pipe 100 and is represented by the following formula (6) using the inner diameter D (inner radius R × 2) of the pipe 100.
A = (D / 2) 2 × π (6)
 数式(5)に表されるw1・v1+w2・v2+w3・v3の部分は、平均流速を示し、誤差εは、平均流速の積分誤差に該当する。よって、数式(5)の演算により、誤差εを加味して、流量Qを演算でき、これにより、流量Qを精度よく演算することができる。 The parts of w1, v1 + w2, v2 + w3, and v3 shown in Equation (5) indicate the average flow velocity, and the error ε corresponds to the integration error of the average flow velocity. Therefore, the flow rate Q can be calculated by adding the error ε by the calculation of the equation (5), whereby the flow rate Q can be calculated with high accuracy.
 また、図2に示す粘度演算部51では、レイノルズ数を求める以下の数式(7)を変形した数式(8)を用いて、流体102の動粘度νを演算する。
 Re=D・v/ν                     (7)
 ν=D・v/Re                     (8)
2 calculates the kinematic viscosity ν of the fluid 102 using Equation (8) obtained by modifying the following Equation (7) for obtaining the Reynolds number.
Re = D · v / ν (7)
ν = D · v / Re (8)
 なお、数式(7)、及び、数式(8)に示す流速vには、図1に示す配管100の中心を通る測線αの流速値v1を用いることができる。 In addition, the flow velocity value v1 of the survey line α passing through the center of the pipe 100 shown in FIG. 1 can be used as the flow velocity v shown in the mathematical formulas (7) and (8).
 図5は、第2の実施の形態の流体計測装置1のブロック図である。なお、図5には、図1に示すA―Aに沿って切断し矢印方向から見た配管100、及び、超音波プローブ10a、10bの部分断面図を含む。以下、図2に示す第1の実施の形態のブロック図と異なる箇所を中心に説明する。 FIG. 5 is a block diagram of the fluid measuring apparatus 1 according to the second embodiment. 5 includes a partial cross-sectional view of the pipe 100 and the ultrasonic probes 10a and 10b cut along the line AA shown in FIG. 1 and viewed from the arrow direction. In the following, description will be made centering on differences from the block diagram of the first embodiment shown in FIG.
 図5では、図2に示すレイノルズ数演算部46、流速比―レイノルズ数変換テーブル47、レイノルズ数-誤差変換テーブル48、及び、粘度演算部51が設けられていない。一方、図5に示す第2の実施の形態では、誤差演算部44が、流速比演算部43と電気的に接続されており、誤差演算部44では、流速比演算部43から流速比を取得し、流速比に基づいて、誤差εを演算する。 5, the Reynolds number calculation unit 46, the flow rate ratio-Reynolds number conversion table 47, the Reynolds number-error conversion table 48, and the viscosity calculation unit 51 shown in FIG. 2 are not provided. On the other hand, in the second embodiment shown in FIG. 5, the error calculation unit 44 is electrically connected to the flow rate ratio calculation unit 43, and the error calculation unit 44 acquires the flow rate ratio from the flow rate ratio calculation unit 43. Then, the error ε is calculated based on the flow rate ratio.
 また図5に示すように、流速比-誤差変換テーブル45は、誤差演算部44に電気的に接続される。流速比-誤差変換テーブル45は、流量を演算するにあたって予め用意されている。流速比-誤差変換テーブル45では、流速比と、誤差εとが相関づけられている。そして、誤差演算部44では、流速比に基づいて、流速比-誤差変換テーブル45から誤差εを演算する。 Also, as shown in FIG. 5, the flow rate ratio-error conversion table 45 is electrically connected to the error calculation unit 44. The flow rate ratio-error conversion table 45 is prepared in advance for calculating the flow rate. In the flow rate ratio-error conversion table 45, the flow rate ratio and the error ε are correlated. Then, the error calculator 44 calculates an error ε from the flow rate ratio-error conversion table 45 based on the flow rate ratio.
 図5に示すように、流量演算部50は、流速演算部42、及び、誤差演算部44と電気的に接続される。流量演算部50では、平均流速、及び、誤差に基づいて流量を演算する。 As shown in FIG. 5, the flow rate calculation unit 50 is electrically connected to the flow rate calculation unit 42 and the error calculation unit 44. The flow rate calculation unit 50 calculates the flow rate based on the average flow velocity and the error.
 図6は、流速比と、誤差εとの相関を表したグラフである。既に説明した図3、及び、図4の相関関係により、流速比からレイノルズ数を求めることができ、レイノルズ数から誤差εを推定できる。よって、流速比から誤差εを推定することができる。 FIG. 6 is a graph showing the correlation between the flow rate ratio and the error ε. 3 and 4 described above, the Reynolds number can be obtained from the flow rate ratio, and the error ε can be estimated from the Reynolds number. Therefore, the error ε can be estimated from the flow rate ratio.
 図6に示す乱流域においては、流速比と誤差εとの関係を、2次関数で近似(最小二乗法)でき、或いは、折線近似できる。 In the turbulent flow region shown in FIG. 6, the relationship between the flow velocity ratio and the error ε can be approximated by a quadratic function (least square method) or can be approximated by a broken line.
 すなわち、図5に示す誤差演算部44では、例えば、流速比―誤差変換テーブル45から2次関数で近似した式を導き出し、流速比演算部43から取得された流速比を、2次関数で近似した式に当てはめることで、誤差εを算出することができる。 That is, in the error calculation unit 44 shown in FIG. 5, for example, an equation approximated by a quadratic function is derived from the flow rate ratio-error conversion table 45, and the flow rate ratio acquired from the flow rate ratio calculation unit 43 is approximated by a quadratic function. By applying the above equation, the error ε can be calculated.
 図5に示す流量演算部50では、上記に記載した数式(5)により流量Qを演算することができる。このように本実施の形態では、流量Qの演算に、平均流速の誤差εを加味することができ、よって、流量Qを精度よく演算することができる。 In the flow rate calculation unit 50 shown in FIG. 5, the flow rate Q can be calculated by the mathematical formula (5) described above. As described above, in the present embodiment, the error ε of the average flow velocity can be added to the calculation of the flow rate Q, so that the flow rate Q can be calculated with high accuracy.
 図7は、図6の乱流域における流速比と誤差εとの関係を、2次関数で近似した式を用いて図6の誤差を推定して補正した後の、流量誤差を示している。すなわち、図6は、補正前の誤差を示し、図7は、補正後の誤差を示している。図7に示す誤差は、図6に示した誤差εに比べて、最大で1/100倍にまで小さくでき、本実施の形態によれば、流量の誤差を極めて小さくすることができる。 FIG. 7 shows a flow rate error after correcting the relationship between the flow rate ratio and the error ε in the turbulent flow region of FIG. 6 by estimating the error of FIG. 6 using an equation approximated by a quadratic function. That is, FIG. 6 shows the error before correction, and FIG. 7 shows the error after correction. The error shown in FIG. 7 can be reduced to a maximum of 1/100 times the error ε shown in FIG. 6, and according to the present embodiment, the flow rate error can be extremely reduced.
 なお、本発明は上記実施の形態に限定されず、種々変更して実施することが可能である。上記実施の形態において、添付図面に図示されている構成については、これに限定されず、本発明の効果を発揮する範囲内で適宜変更することが可能である。その他、本発明の目的の範囲を逸脱しない限りにおいて適宜変更して実施することが可能である。 It should be noted that the present invention is not limited to the above embodiment, and can be implemented with various modifications. In the above-described embodiment, the configuration illustrated in the accompanying drawings is not limited to this, and can be appropriately changed within a range in which the effect of the present invention is exhibited. In addition, various modifications can be made without departing from the scope of the object of the present invention.
 例えば、本実施の形態においては、流量、レイノルズ数、及び、動粘度を、流体の物理量として測定している。特に、図2、及び、図5は共に、最終的に、流体102の流量を求めるためのブロック構成となっている。ただし、例えば、図2において、流量まで求めず、レイノルズ数と動粘度、或いは、レイノルズ数のみを演算する構成とすることも出来る。 For example, in the present embodiment, the flow rate, the Reynolds number, and the kinematic viscosity are measured as physical quantities of the fluid. In particular, both FIG. 2 and FIG. 5 have a block configuration for finally determining the flow rate of the fluid 102. However, for example, in FIG. 2, it is possible to calculate only the Reynolds number and the kinematic viscosity, or the Reynolds number without obtaining the flow rate.
 また、本実施の形態では、特に、限定するものではないが、スプール型の流体計測装置に好ましく適用できる。 Further, in the present embodiment, although not particularly limited, it can be preferably applied to a spool type fluid measuring device.
 最後に、上記の実施の形態における特徴点を整理する。 Finally, the feature points in the above embodiment are organized.
 本実施の形態の流体計測装置1は、配管100に設置した複数の超音波プローブから配管100内の流体102へ超音波を送受信することにより複数の測線α、β、γを形成し、制御部60にて、流体102の物理量を求める流体計測装置1において、制御部60は、複数の測線α、β、γで計測した流体102の流速を演算する流速演算部42と、流体102の流速に基づいて、流速比を演算する流速比演算部43と、流速比に基づいて、物理量を演算する物理量演算部と、を有することを特徴とする。ここで、物理量演算部は、図1、図2の実施の形態では、レイノルズ数演算部46、流量演算部50、及び、粘度演算部51が該当する。 The fluid measuring apparatus 1 of the present embodiment forms a plurality of measurement lines α, β, γ by transmitting and receiving ultrasonic waves from a plurality of ultrasonic probes installed in the pipe 100 to the fluid 102 in the pipe 100, and a control unit 60, in the fluid measuring device 1 for obtaining the physical quantity of the fluid 102, the control unit 60 calculates the flow velocity of the fluid 102 measured by a plurality of measurement lines α, β, γ, and the flow velocity of the fluid 102. The flow rate ratio calculating unit 43 calculates a flow rate ratio based on the flow rate ratio, and the physical quantity calculation unit calculates a physical quantity based on the flow rate ratio. Here, the physical quantity calculation unit corresponds to the Reynolds number calculation unit 46, the flow rate calculation unit 50, and the viscosity calculation unit 51 in the embodiment of FIGS.
 このように、本実施の形態では、流体102の流速の比に基づいて、流体102の物理量を求めることが可能であり、特に、層流・乱流にかかわらず物理量を高精度に計測できる。したがって、層流用と乱流用とに分けて別々の流体計測装置を用意する必要がなく、一台の流体計測装置で高精度な計測を行うことが可能である。 As described above, in this embodiment, the physical quantity of the fluid 102 can be obtained based on the ratio of the flow rates of the fluid 102, and in particular, the physical quantity can be measured with high accuracy regardless of the laminar flow / turbulent flow. Therefore, it is not necessary to prepare separate fluid measurement devices for laminar flow and turbulent flow, and it is possible to perform highly accurate measurement with a single fluid measurement device.
 また、本実施の形態では、物理量演算部は、少なくとも流体102の流量を演算する流量演算部50であり、更に、流速から数値積分法により演算される平均流速の誤差を求める誤差演算部44を、具備しており、流量演算部50では、平均流速と、誤差演算部44で得られた誤差とを用いて、流体102の流量を演算することが好ましい。図2、及び、図5に示す実施の形態が該当する。これにより、流量演算において、誤差を加味することができ、特に、誤差変動が大きい乱流域において、流量を高精度に演算することができる。 In the present embodiment, the physical quantity calculation unit is a flow rate calculation unit 50 that calculates at least the flow rate of the fluid 102, and further includes an error calculation unit 44 that calculates an error in the average flow velocity calculated from the flow velocity by the numerical integration method. The flow rate calculation unit 50 preferably calculates the flow rate of the fluid 102 using the average flow velocity and the error obtained by the error calculation unit 44. The embodiment shown in FIGS. 2 and 5 corresponds to this embodiment. Thereby, an error can be taken into account in the flow rate calculation, and in particular, the flow rate can be calculated with high accuracy in a turbulent flow region where the error fluctuation is large.
 また、本実施の形態では、レイノルズ数演算部46を、更に備えており、レイノルズ数演算部46では、流速比に基づいてレイノルズ数を演算し、誤差演算部44では、誤差を、レイノルズ数に基づいて演算する構成とすることができる。図2に示す実施の形態が該当する。これにより、物理量として、レイノルズ数と共に、流量を取得することができる。特に、本実施の形態では、レイノルズ数の演算に必要であった配管寸法と動粘度を必要とすることなく、流速比に基づいて、レイノルズ数を簡単且つ精度よく演算することができる。また、レイノルズ数を演算することで、誤差演算部44では、レイノルズ数に基づく誤差を演算できる。そして、流量演算部50では、平均流速と、誤差演算部44で得られた誤差とを用いて、流体102の流量を精度よく演算することが可能である。 In this embodiment, the Reynolds number calculation unit 46 is further provided. The Reynolds number calculation unit 46 calculates the Reynolds number based on the flow rate ratio, and the error calculation unit 44 converts the error into the Reynolds number. It can be set as the structure calculated based on. The embodiment shown in FIG. Thereby, the flow rate can be acquired as the physical quantity together with the Reynolds number. In particular, in the present embodiment, the Reynolds number can be calculated easily and accurately based on the flow rate ratio without requiring piping dimensions and kinematic viscosity that were necessary for the calculation of the Reynolds number. Further, by calculating the Reynolds number, the error calculation unit 44 can calculate an error based on the Reynolds number. The flow rate calculation unit 50 can accurately calculate the flow rate of the fluid 102 using the average flow velocity and the error obtained by the error calculation unit 44.
 また、本実施の形態では、レイノルズ数と誤差との変換テーブル48を、更に備えており、誤差演算部44では、レイノルズ数演算部46から取得されたレイノルズ数を用いて、レイノルズ数-誤差変換テーブル48に基づき、誤差を演算することが好ましい。図2に示す実施の形態が該当する。このように、予め、レイノルズ数-誤差変換テーブル48を設けておくことで、レイノルズ数を取得すれば、迅速に誤差を演算でき、ひいては、流量の演算処理時間を短縮することができる。 In the present embodiment, a Reynolds number / error conversion table 48 is further provided, and the error calculation unit 44 uses the Reynolds number obtained from the Reynolds number calculation unit 46 to perform Reynolds number-error conversion. It is preferable to calculate the error based on the table 48. The embodiment shown in FIG. In this way, by providing the Reynolds number-error conversion table 48 in advance, if the Reynolds number is obtained, the error can be calculated quickly, and consequently the flow rate calculation processing time can be shortened.
 また、本実施の形態では、物理量演算部は、少なくとも流体のレイノルズ数を演算するレイノルズ数演算部46であり、レイノルズ数演算部46では、流速比に基づいてレイノルズ数を算出することが好ましい。図2に示す実施の形態、及び、その変形が該当する。図2の変形とは、図2では、流体102の流量まで演算しているが、流量まで演算しない形態が該当する。これにより、本実施の形態では、レイノルズ数の演算に必要であった配管寸法と動粘度を必要とすることなく、流速比に基づいて、レイノルズ数を簡単且つ精度よく演算することができる。 Further, in the present embodiment, the physical quantity calculation unit is a Reynolds number calculation unit 46 that calculates at least the Reynolds number of the fluid, and the Reynolds number calculation unit 46 preferably calculates the Reynolds number based on the flow rate ratio. The embodiment shown in FIG. 2 and its modifications are applicable. The deformation of FIG. 2 corresponds to a form in which the flow rate of the fluid 102 is calculated in FIG. Thus, in this embodiment, the Reynolds number can be calculated easily and accurately based on the flow rate ratio without requiring the piping dimensions and kinematic viscosity required for the calculation of the Reynolds number.
 また、本実施の形態では、流速比とレイノルズ数との変換テーブル47を、更に備えており、レイノルズ数演算部46では、流速比演算部43から取得された流速比を用いて、流速比-レイノルズ数変換テーブル47に基づき、レイノルズ数を演算することが好ましい。図2に示す実施の形態が該当する。このように、予め、流速比―レイノルズ数変換テーブル47を設けておくことで、流速比を取得すれば、迅速かつ精度よくレイノルズ数を演算できる。 In the present embodiment, a conversion table 47 between the flow rate ratio and the Reynolds number is further provided. The Reynolds number calculation unit 46 uses the flow rate ratio acquired from the flow rate ratio calculation unit 43 to use the flow rate ratio − It is preferable to calculate the Reynolds number based on the Reynolds number conversion table 47. The embodiment shown in FIG. Thus, by providing the flow rate ratio-Reynolds number conversion table 47 in advance, the Reynolds number can be calculated quickly and accurately if the flow rate ratio is acquired.
 また、本実施の形態では、粘度演算部51を、更に備えており、粘度演算部51では、レイノルズ数演算部46にて求められたレイノルズ数に基づいて、流体102の動粘度を演算することが可能である。図2に示す実施の形態が該当する。このように、本実施の形態では、レイノルズ数とともに動粘度を迅速かつ高精度に演算することができる。 Further, in the present embodiment, a viscosity calculation unit 51 is further provided, and the viscosity calculation unit 51 calculates the kinematic viscosity of the fluid 102 based on the Reynolds number obtained by the Reynolds number calculation unit 46. Is possible. The embodiment shown in FIG. Thus, in this Embodiment, kinematic viscosity can be calculated rapidly and with high precision with Reynolds number.
 また、本実施の形態では、流速比と誤差との変換テーブル45を、更に備えており、誤差演算部44では、流速比演算部43から取得された流速比を用いて、流速比-誤差変換テーブル45に基づき、誤差を演算することが可能である。図5に示す実施の形態が該当する。これにより、流量演算において、誤差を加味することができ、特に、誤差変動が大きい乱流域において、流量を高精度に演算することができる。特に、本実施の形態では、流速比を演算することで、誤差演算部44では、流速比に基づく誤差を演算できる。そして、流量演算部50では、平均流速と、誤差演算部44で得られた誤差とを用いて、流体の流量を度よく演算することが可能である。図5の実施の形態においては、図2のように、レイノルズ数の演算を必要とせず、流速比に基づいて、迅速かつ精度よく、流量演算を行うことが可能である。 In this embodiment, the flow rate ratio / error conversion table 45 is further provided. The error calculation unit 44 uses the flow rate ratio acquired from the flow rate ratio calculation unit 43 to convert the flow rate ratio into the error. Based on the table 45, the error can be calculated. The embodiment shown in FIG. Thereby, an error can be taken into account in the flow rate calculation, and in particular, the flow rate can be calculated with high accuracy in a turbulent flow region where the error fluctuation is large. In particular, in the present embodiment, the error calculation unit 44 can calculate an error based on the flow rate ratio by calculating the flow rate ratio. The flow rate calculation unit 50 can calculate the flow rate of the fluid frequently using the average flow velocity and the error obtained by the error calculation unit 44. In the embodiment of FIG. 5, as shown in FIG. 2, it is possible to calculate the flow rate quickly and accurately based on the flow rate ratio without requiring the calculation of the Reynolds number.
 また、本実施の形態では、図1に示すように、複数の測線α、β、γは、平行であることが、平均流速を求めるうえでの数値積分の精度を向上させることができ、好適である。 Further, in the present embodiment, as shown in FIG. 1, it is possible for the plurality of measurement lines α, β, and γ to be parallel to improve the accuracy of numerical integration in obtaining the average flow velocity, which is preferable. It is.
 以上説明した本発明は、流体の物理量、具体的には、流量や、レイノルズ数、及び、動粘度等を計測するための流体計測装置に有用である。 The present invention described above is useful for a fluid measurement device for measuring a physical quantity of a fluid, specifically, a flow rate, a Reynolds number, a kinematic viscosity, and the like.
 本出願は、2016年10月25日出願の特願2016-208860に基づく。この内容は、全てここに含めておく。 This application is based on Japanese Patent Application No. 2016-208860 filed on Oct. 25, 2016. All this content is included here.

Claims (10)

  1.  配管に設置した複数の超音波送受信部から前記配管内の流体へ超音波を送受信することにより複数の測線を形成し、制御部にて、前記流体の物理量を求める流体計測装置において、
     前記制御部は、前記複数の測線で計測した前記流体の流速を演算する流速演算部と、
     前記流体の流速に基づいて、流速比を演算する流速比演算部と、
     前記流速比に基づいて、前記物理量を演算する物理量演算部と、
     を有することを特徴とする流体計測装置。
    In a fluid measurement device that forms a plurality of measurement lines by transmitting and receiving ultrasonic waves to and from the fluid in the pipe from a plurality of ultrasonic transmission and reception units installed in the pipe, and in the control unit to obtain the physical quantity of the fluid,
    The control unit is a flow rate calculation unit that calculates the flow rate of the fluid measured by the plurality of survey lines,
    A flow rate ratio calculation unit for calculating a flow rate ratio based on the flow rate of the fluid;
    A physical quantity computing unit for computing the physical quantity based on the flow rate ratio;
    A fluid measuring device comprising:
  2.  前記物理量演算部は、少なくとも前記流体の流量を演算する流量演算部であり、
     更に、前記流速演算部により演算される平均流速の誤差を求める誤差演算部を、具備しており、
     前記流量演算部では、前記平均流速と、前記誤差演算部で得られた前記誤差とを用いて、前記流体の流量を演算することを特徴とする請求項1に記載の流体計測装置。
    The physical quantity calculation unit is a flow rate calculation unit that calculates at least the flow rate of the fluid,
    Furthermore, an error calculation unit for obtaining an error of the average flow velocity calculated by the flow velocity calculation unit is provided,
    2. The fluid measurement device according to claim 1, wherein the flow rate calculation unit calculates the flow rate of the fluid using the average flow velocity and the error obtained by the error calculation unit.
  3.  前記流速演算部は、前記流速から数値積分法により平均流速を演算することを特徴とする請求項2に記載の流体計測装置。 3. The fluid measuring device according to claim 2, wherein the flow velocity calculation unit calculates an average flow velocity from the flow velocity by a numerical integration method.
  4.  レイノルズ数演算部を、更に備えており、
     前記レイノルズ数演算部では、前記流速比に基づいてレイノルズ数を演算し、
     前記誤差演算部では、前記誤差を、前記レイノルズ数に基づいて演算することを特徴とする請求項3に記載の流体計測装置。
    A Reynolds number calculation unit,
    The Reynolds number calculation unit calculates the Reynolds number based on the flow rate ratio,
    The fluid measurement apparatus according to claim 3, wherein the error calculation unit calculates the error based on the Reynolds number.
  5.  前記レイノルズ数と前記誤差との変換テーブルを、更に備えており、
     前記誤差演算部では、前記レイノルズ数演算部から取得された前記レイノルズ数を用いて、レイノルズ数-誤差変換テーブルに基づき、前記誤差を演算することを特徴とする請求項4に記載の流体計測装置。
    Further comprising a conversion table between the Reynolds number and the error,
    5. The fluid measurement device according to claim 4, wherein the error calculation unit calculates the error based on a Reynolds number-error conversion table using the Reynolds number acquired from the Reynolds number calculation unit. .
  6.  前記物理量演算部は、少なくとも前記流体のレイノルズ数を演算するレイノルズ数演算部であり、
     前記レイノルズ数演算部では、前記流速比に基づいてレイノルズ数を算出することを特徴とする請求項1に記載の流体計測装置。
    The physical quantity computing unit is a Reynolds number computing unit that computes at least the Reynolds number of the fluid,
    The fluid measuring apparatus according to claim 1, wherein the Reynolds number calculation unit calculates a Reynolds number based on the flow rate ratio.
  7.  前記流速比と前記レイノルズ数との変換テーブルを、更に備えており、
     前記レイノルズ数演算部では、前記流速比演算部から取得された流速比を用いて、流速比-レイノルズ数変換テーブルに基づき、前記レイノルズ数を演算することを特徴とする請求項4から請求項6のいずれかに記載の流体計測装置。
    A conversion table between the flow rate ratio and the Reynolds number;
    7. The Reynolds number calculation unit calculates the Reynolds number based on a flow rate ratio-Reynolds number conversion table using the flow rate ratio acquired from the flow rate ratio calculation unit. The fluid measuring device according to any of the above.
  8.  粘度演算部を、更に備えており、
     前記粘度演算部では、前記レイノルズ数演算部にて求められた前記レイノルズ数に基づいて、前記流体の動粘度を演算することを特徴とする請求項4から請求項7のいずれかに記載の流体計測装置。
    It further includes a viscosity calculation unit,
    The fluid according to any one of claims 4 to 7, wherein the viscosity calculating unit calculates a kinematic viscosity of the fluid based on the Reynolds number obtained by the Reynolds number calculating unit. Measuring device.
  9.  前記流速比と前記誤差との変換テーブルを、更に備えており、
     前記誤差演算部では、前記流速比演算部から取得された流速比を用いて、流速比-誤差変換テーブルに基づき、前記誤差を演算することを特徴とする請求項3に記載の流体計測装置。
    A conversion table of the flow rate ratio and the error is further provided;
    4. The fluid measuring device according to claim 3, wherein the error calculation unit calculates the error based on a flow rate ratio-error conversion table using the flow rate ratio acquired from the flow rate ratio calculation unit.
  10.  前記複数の測線は、平行であることを特徴とする請求項1から請求項9のいずれかに記載の流体計測装置。 The fluid measuring device according to any one of claims 1 to 9, wherein the plurality of survey lines are parallel to each other.
PCT/JP2017/036900 2016-10-25 2017-10-12 Fluid measuring device WO2018079269A1 (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109917152A (en) * 2019-04-12 2019-06-21 江苏亚楠电子科技有限公司 A kind of mean velocity in vertical measurement method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3478833B2 (en) * 1995-11-22 2003-12-15 クローネ アクチェンゲゼルシャフト Ultrasonic flow measurement method

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3478833B2 (en) * 1995-11-22 2003-12-15 クローネ アクチェンゲゼルシャフト Ultrasonic flow measurement method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109917152A (en) * 2019-04-12 2019-06-21 江苏亚楠电子科技有限公司 A kind of mean velocity in vertical measurement method

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