JP2002082098A - Fluid type discriminator and flow meter - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a fluid type discriminating apparatus and a flow meter which can effectively use information on physical properties of a fluid. SOLUTION: When an ultrasonic transmitting unit 3 transmits an ultrasonic wave to a fluid F, an ultrasonic wave passing through the fluid F is received by the ultrasonic receiving unit 4 and a sound speed of the ultrasonic wave passing through the fluid F is determined as a sound speed. The measuring unit 7 measures. The fluid information storage unit 8 stores information on the speed of sound of ultrasonic waves passing through the fluid F for each fluid. The fluid type determination unit 9 reads out the fluid information corresponding to the sound speed information output from the sound speed measurement unit 7 from the fluid information storage unit 8 and determines the type of the fluid F. Fluid type discriminator 9
For example, when water and oil alternately flow in the measuring tube 1 or when the fluid F flowing in the measuring tube 1 changes from water to oil, the type of the fluid F currently flowing in the measuring tube 1 , The change of the fluid F flowing in the measuring tube 1 is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid type discriminating device for discriminating the type of a fluid and a flow meter for measuring a flow rate of a fluid flowing in a measuring pipe.

[0002]

FIG. 8 is a block diagram of a conventional ultrasonic vortex flowmeter. FIG. 9 is a configuration diagram of a vortex detector of a conventional ultrasonic vortex flowmeter. 2. Description of the Related Art Conventionally, there has been known an ultrasonic vortex flowmeter that measures the flow rate of a fluid flowing in a measurement tube using ultrasonic waves. For example, a conventional ultrasonic vortex flowmeter 10 shown in FIG.
1 includes a vortex generator 103 that generates a vortex in the measurement tube 102 through which the fluid F flows, and a vortex detector 104 that detects a row of vortices downstream of the vortex generator 103. As shown in FIG. 9, the vortex detector 104 includes two sets of ultrasonic transmitters 104a and 104b and two sets of ultrasonic receivers 104c and 104c.
104d, an oscillation circuit 104e, and a phase comparator 104f
And The oscillation circuit 104e is connected to the ultrasonic transmitter 10
When ultrasonic waves are oscillated at 4a and 104b and the vortex passes through the path of the ultrasonic wave, the phase of the ultrasonic wave changes and the path S ₀ → S ₁
And the path S ₀ → S ₂ , the direction of the phase shift changes.
In the conventional ultrasonic vortex flowmeter 101, the ultrasonic receiver 10
The vortex signal is detected by comparing the phases of the two received waveforms received by 4c and 104d by the phase comparator 101f.

[0003]

In the conventional ultrasonic vortex flowmeter 101, since the purpose is to measure the flow rate, the fluid F
From the ultrasonic wave that has passed through, and extracts only information relating to the phase change necessary for measuring the flow rate, and performs signal processing. However, the ultrasonic wave passing through the measurement target contains much information on the physical properties of the measurement target. In particular, the sound speed of the ultrasonic wave is an index indicating the property of the object to be measured, but has not been used at all.

[0004] It is an object of the present invention to provide a fluid type discriminating apparatus and a flow meter that can effectively use information on the physical properties of a fluid.

[0005]

The present invention solves the above-mentioned problems by the following means. Note that description will be given with reference numerals corresponding to the embodiment of the present invention, but the present invention is not limited to this embodiment. The invention of claim 1 is
An ultrasonic transmitter (3) for determining the type of a fluid (F), wherein the ultrasonic transmitter transmits an ultrasonic wave to the fluid.
And an ultrasonic receiving unit (4) for receiving an ultrasonic wave passing through the fluid, based on a reception result of the ultrasonic receiving unit,
A fluid comprising: a sound speed measuring unit (7) for measuring a sound speed of an ultrasonic wave passing through the fluid; and a fluid type judging unit (9) for judging the type of the fluid based on a measurement result of the sound speed measuring unit. A type determination device (2).

According to a second aspect of the present invention, there is provided the fluid type discriminating apparatus according to the first aspect, further comprising a fluid information storage section (8) for storing a correlation between the sound speed and the type of the fluid as fluid information. The fluid type discrimination unit is a fluid type discrimination device that reads out the fluid information corresponding to the sound velocity from the fluid information storage unit and discriminates the type of the fluid.

According to a third aspect of the present invention, in the fluid type determining apparatus according to the second aspect, when the plurality of types of fluids flow through the measurement tube, the fluid type determination unit determines the type of the fluid flowing through the measurement tube. A fluid type discrimination device that detects a change.

[0008] The invention of claim 4 is the first to third aspects of the present invention.
The fluid type discriminating apparatus according to any one of the above, wherein a temperature measuring unit (10) for measuring a temperature of the fluid;
A fluid type discriminating device comprising a pressure estimating unit (17) for estimating the pressure of the fluid based on the type of the fluid and the sound speed when the temperature is constant.

According to a fifth aspect of the present invention, in the fluid type discriminating apparatus according to the fourth aspect, a pressure information storage section (11) for storing a correlation between the sound velocity and the pressure as pressure information for each type of the fluid. Wherein the pressure estimating unit reads out the pressure information corresponding to the type of the fluid and the sound velocity from the pressure information storage unit to estimate the pressure.

[0010] The invention of claim 6 is the first to third aspects of the present invention.
In the fluid type discriminating apparatus according to any one of the above, a pressure measuring unit (13) that measures a pressure of the fluid,
A fluid type discriminating apparatus comprising: a temperature estimating unit (15) for estimating the temperature of the fluid based on the type of the fluid and the sound velocity when the pressure is constant.

According to a seventh aspect of the present invention, in the fluid type discriminating apparatus according to the sixth aspect, a temperature information storage section (14) for storing a correlation between the sound velocity and the temperature as temperature information for each type of the fluid. Wherein the temperature estimating unit reads out the temperature information corresponding to the type of the fluid and the sound velocity from the temperature information storage unit to estimate the temperature.

[0012] The invention of claim 8 is the first to third aspects of the present invention.
The fluid type discriminating apparatus according to any one of the above, wherein a temperature measuring unit (10) for measuring a temperature of the fluid;
A fluid type discriminating apparatus comprising: a density estimating unit (17) for estimating the density of the fluid based on the type of the fluid and the sound velocity when the temperature is constant.

[0013] The ninth aspect of the present invention is the first to third aspects.
In the fluid type discriminating apparatus according to any one of the above, a pressure measuring unit (13) that measures a pressure of the fluid,
A fluid type discriminating apparatus, comprising: a density estimating unit (17) for estimating the density of the fluid based on the type of the fluid and the sound velocity when the pressure is constant.

According to a tenth aspect of the present invention, in the fluid type discriminating apparatus according to the eighth or ninth aspect, density information storage for storing a correlation between the sound velocity and the density as density information for each type of the fluid. A fluid type discriminating device, comprising: a unit (16), wherein the density estimating unit reads the density information corresponding to the type of the fluid and the sound velocity from the density information storage unit and estimates the density. It is.

According to an eleventh aspect of the present invention, in the fluid type discriminating apparatus according to any one of the first to ninth aspects, at least one of the type of the fluid, the pressure, the temperature, or the density is provided. Display for displaying information (20)
A fluid type discriminating apparatus comprising:

According to a twelfth aspect of the present invention, there is provided a flow meter for measuring a flow rate of a fluid (F) flowing in a measuring pipe (1), wherein the fluid according to any one of the first to eleventh aspects is provided. A type discrimination device (2) and a flow rate calculation unit (2) that calculates a flow rate of the fluid based on a reception result of the ultrasonic reception unit (4).
5) The flow meter (22) comprising:

(First Embodiment) Hereinafter, referring to the drawings,
The first embodiment of the present invention will be described in detail. FIG.
FIG. 1 is a configuration diagram of a fluid type determination device according to a first embodiment of the present invention. The measurement tube 1 is a flow path through which the fluid F flows. A fluid F such as a gas, a liquid, or a vapor flows through the measurement tube 1 in the direction of the arrow in the figure. The fluid type determination device 2 is a device that determines the type of fluid. The fluid type discriminating apparatus 2 is shown in FIG.
As shown in, the ultrasonic transmitting unit 3, the ultrasonic receiving unit 4,
Drive circuit 5, signal processing circuit 6, sound velocity measuring section 7, fluid information storage section 8, fluid type determining section 9, temperature measuring section 1
0, a pressure information storage unit 11, a pressure estimation unit 12, a pressure measurement unit 13, a temperature information storage unit 14, and a temperature estimation unit 15.
And a density information storage unit 16, a density estimation unit 17, a control unit 18, a mode switching unit 19, a display unit 20, and a data output unit 21.

The ultrasonic transmitter 3 is a device for transmitting ultrasonic waves to the fluid F. The ultrasonic transmitter 3 is attached to the outer peripheral surface of the measurement tube 2 and transmits an ultrasonic wave into the measurement tube 2. The ultrasonic receiver 4 is a device that receives an ultrasonic wave that passes through the fluid F. The ultrasonic receiving unit 4 is attached to the outer peripheral surface of the measuring tube 2 and is arranged to face the ultrasonic transmitting unit 3. The drive circuit 5 is a circuit for driving the ultrasonic transmission unit 3, and includes an oscillation circuit that causes the ultrasonic transmission unit 3 to oscillate ultrasonic waves. The signal processing circuit 6 is a circuit that performs predetermined processing on an output signal output from the ultrasonic receiving unit 4. The signal processing circuit 6 includes an amplifier circuit for amplifying an output signal of the ultrasonic receiving unit 4, a filter circuit for passing a predetermined frequency component, and the like.

The sound velocity measuring section 7 is a section for measuring the sound velocity of the ultrasonic wave passing through the fluid F based on the reception result of the ultrasonic receiving section 4. Based on the propagation distance D of the ultrasonic wave passing through the fluid portion and the propagation time t of the ultrasonic wave passing through the fluid portion, the sound speed measuring section 7 determines the sound speed V of the ultrasonic wave passing through the fluid F = D / Calculate t. The sound speed measuring unit 7 outputs the calculated sound speed V as sound speed information to the fluid type determining unit 9, the pressure estimating unit 12, the temperature estimating unit 15, and the density estimating unit 17.

The fluid information storage section 8 is a section for storing, as fluid information, a correlation between the sound velocity V measured by the sound velocity measuring section 7 and the type of the fluid F flowing in the measuring tube 1. The sound velocity V of the ultrasonic wave passing through the fluid F shows different values according to the type, temperature, pressure, and density of the fluid F. For example, the sound velocity V of an ultrasonic wave passing through water is about 1500 (m / s), and the sound velocity V of an ultrasonic wave passing through oil is about 1000 (m / s).
s) The following is true. The fluid information storage unit 8 stores information on the sound velocity V of the ultrasonic wave passing through the fluid F for each fluid.

The fluid type discriminating section 9 is a section for discriminating the type of the fluid F based on the measurement result of the sound velocity measuring section 7.
The fluid type determination unit 9 reads the fluid information corresponding to the sound speed information from the fluid information storage unit 8 and determines the type of the fluid F. For example, when the determination level (threshold) V _th = 1200 (m / s) for determining water and oil, the measured sound velocity V is higher than the determination level V _th. Sometimes, it is determined that the fluid F is water, and when the measured sound velocity V is lower than the determination level _Vth, it is determined that the fluid F is oil. The fluid type discriminating unit 9 may, for example, alternately flow water and oil into the measurement tube 1 or
When the fluid F flowing inside changes from water to oil, the measuring tube 1
It detects the type of the fluid F currently flowing in the inside and changes in the fluid F flowing in the measuring tube 1 and outputs the detection results as fluid information.

The temperature measuring section 10 is a device for measuring the temperature of the fluid F. The temperature measurement unit 10 includes a sensor for detecting the temperature of the fluid F flowing in the measurement tube 1 and the like. The temperature measurement unit 10 outputs the measured temperature of the fluid F to the pressure estimation unit 12 as temperature information.

The pressure information storage section 11 is a section for storing the correlation between the sound velocity measured by the sound velocity measuring section 7 and the pressure of the fluid F as pressure information for each type of the fluid F. When the type of the fluid F is the same, the sound speed of the ultrasonic wave passing through the fluid F is determined by a function of the temperature and the pressure.
If one of the temperature and the pressure is measured by determining the type, the other can be estimated. For example, when the temperature of the fluid F flowing in the measurement tube 1 is constant, the pressure of the fluid F can be estimated based on the sound speed of the ultrasonic wave passing through the fluid F. The pressure information storage unit 11 includes a pressure information table for estimating a pressure from the sound speed measured by the sound speed measurement unit 7 and the temperature measured by the temperature measurement unit 10.

FIG. 2 is a view for explaining a pressure information table stored in the pressure information storage section of the fluid type discriminating apparatus according to the first embodiment of the present invention. Longitudinal column shown in Figure 2, temperature T ₁ of the temperature measuring unit 10 has measured, ..., a T _n, Yokoran the acoustic velocity V ₁ sound speed measuring section 7 is measured, ..., V _m
It is. In the pressure information storage unit 11, as shown in FIG.
The speed of sound V ₁ , when each temperature T ₁ ,..., _Tn is constant,
..., the pressure P ₁₁ corresponding to V _m, ..., P _nm fluid F _1, F ₂
, ..., it is converted into a table as a pressure information stored for each F _x. For example, the fluid F ₁ measured by the temperature measurement unit 10
A temperature T = T _2, the fluid sound speed measuring section 7 is measured F
If it is the _first acoustic velocity V = V ₃ is a pressure P = P ₂₃ when temperature T ₂ of the fluid F ₁ is constant.

When the temperature is constant, the pressure estimating section 12 shown in FIG. 1 estimates the pressure of the fluid F based on the type and sound speed of the fluid F. The pressure estimating unit 12 reads pressure information corresponding to the type of the fluid F determined by the fluid type determining unit 9 and the sound speed measured by the sound speed measuring unit 7 from the pressure information storage unit 11, and estimates the pressure of the fluid F. I do. The pressure estimation unit 12 outputs the pressure information read from the pressure information storage unit 11 to the control unit 18. As described above, in the first embodiment, a pressure measurement function can be added to the fluid type determination device 2.

The pressure measuring section 13 is a device for measuring the pressure of the fluid F. The pressure measuring unit 13 includes a sensor that detects the pressure of the fluid F flowing in the measuring tube 1 and the like. The pressure measuring unit 13 outputs the measured pressure of the fluid F to the temperature estimating unit 15 as pressure information.

The temperature information storage section 14 is a section for storing the correlation between the sound velocity measured by the sound velocity measuring section 7 and the temperature of the fluid F as temperature information for each type of the fluid F. When the pressure of the fluid F flowing in the measurement tube 1 is constant, the fluid F
The temperature of the fluid F can be estimated based on the speed of sound of the ultrasonic wave that has passed through. The temperature information storage unit 14 includes a temperature information table for estimating a temperature from the sound speed measured by the sound speed measurement unit 7 and the pressure measured by the pressure measurement unit 13.

FIG. 3 is a view for explaining a temperature information table stored in the temperature information storage section of the fluid type discriminating apparatus according to the first embodiment of the present invention. Longitudinal column shown in FIG. 3, the pressure P ₁ of the pressure measuring unit 13 has measured, ..., a P _n, Yokoran the acoustic velocity V ₁ sound speed measuring section 7 is measured, ..., V _m
It is. In the temperature information storage unit 14, as shown in FIG.
Each pressure P _1, ..., acoustic velocity V ₁ of the case where P _n is constant,
..., the temperature T ₁₁ corresponding to V _m, ..., T _nm fluid F _1, F ₂
, ..., it is tabulated as the temperature information for each F _x are stored. For example, the fluid F ₁ measured by the pressure measurement unit 13
Pressure P = P ₂ , and the fluid F measured by the sound velocity measuring unit 7
If it is the _first acoustic velocity V = V ₃ is at a temperature T = T ₂₃ when the pressure P ₂ of the fluid F ₁ is constant.

When the pressure is constant, the temperature estimating section 15 shown in FIG. 1 estimates the temperature of the fluid F based on the type and sound speed of the fluid F. The temperature estimating unit 15 reads temperature information corresponding to the type of the fluid F determined by the fluid type determining unit 9 and the sound speed measured by the sound speed measuring unit 7 from the temperature information storage unit 14 and estimates the pressure of the fluid F. I do. The temperature estimating unit 15 outputs the temperature information read from the temperature information storage unit 14 to the control unit 18. As described above, in the first embodiment, a temperature measurement function can be added to the fluid type determination device 2.

The density information storage section 16 is a section for storing the correlation between the sound velocity measured by the sound velocity measuring section 7 and the density of the fluid F as density information for each type of the fluid F. Measuring tube 1
When the fluid F flowing inside is a gas and has a constant temperature or pressure, the density of the fluid F can be estimated based on the sound speed V of the ultrasonic wave passing through the fluid F.
The density information storage unit 16 includes a density information table A for estimating the density from the sound speed measured by the sound speed measurement unit 7 and the temperature measured by the temperature measurement unit 13 when the temperature is constant,
A density information table B for estimating the density from the sound speed measured by the sound speed measuring unit 7 and the pressure measured by the pressure measuring unit 13 when the pressure is constant is provided.

FIG. 4 shows a flow chart according to the first embodiment of the present invention.
Density information stored in the density information storage unit of the body type determination device
FIG. 4 is a diagram for explaining a table A. FIG.
Of density information of the fluid type discriminating apparatus according to the first embodiment of the present invention
For explaining the density information table B stored in the storage unit
FIG. The vertical column shown in FIG.
Temperature T₁ , ..., T_n In the horizontal column, the sound speed measurement unit 7 measures
Fixed sound velocity V₁ , ..., V_m It is. The vertical column shown in FIG.
Pressure P measured by pressure measurement unit 13₁ , ..., P_n And
The horizontal column is the sound velocity V measured by the sound velocity measuring unit 7.₁ , ..., V_m In
You. As shown in FIG.
Degree T₁ , ..., T_n Velocity V when is constant₁ , ..., V
_m And the corresponding density ρ ₁₁,…, Ρ_nmIs fluid F₁ , F_Two ,
…, F_x Tabled and stored as density information for each
I have. In addition, the density information storage unit 16 stores, as shown in FIG.
And each pressure P₁, ..., P_m Velocity V when is constant
₁ , ..., V_n And the corresponding density ρ₁₁,…, Ρ _mnIs fluid F
₁ , F_Two , ..., F_x Is tabulated as density information for each
It is remembered. For example, the flow measured by the temperature measurement unit 10
Body F₁ Temperature T = T_Two And measured by the sound velocity measuring unit 7
Fluid F₁ Speed of sound V = V_Three , This fluid F₁ 
Temperature T_Two Is constant, the density ρ = ρ_{twenty three}It is.

When the temperature or pressure is constant, the density estimating section 17 shown in FIG. 1 estimates the density of the fluid F based on the type of the fluid F and the speed of sound. The density estimating unit 17
The density information corresponding to the type of the fluid F determined by the fluid type determination unit 9 and the sound velocity measured by the sound speed measurement unit 7 is read from the density information storage unit 16 to estimate the density of the fluid F.
The density estimating unit 17 outputs the density information read from the density information storage unit 16 to the control unit 18. As described above, in the first embodiment, a density measurement function can be added to the fluid type determination device 2.

The control unit 18 is a central processing unit (CPU) for controlling various operations of the fluid type discriminating apparatus 2. The control unit 18 includes the drive circuit 5, the temperature measurement unit 10, and the pressure measurement unit 1.
3 and outputs the fluid information output by the fluid type determining unit 9 and the pressure information output by the pressure estimating unit 12 to the display unit 20 and the data output unit 21.

The mode switching section 19 includes a pressure estimation mode for estimating pressure, a temperature estimation mode for estimating temperature, a density estimation mode A for estimating density by measuring temperature, and a density estimation mode A for estimating density by measuring pressure. To switch to the density estimation mode B. The mode switching unit 19 outputs information on the selected estimation mode to the control unit 18. Display unit 20
Is a device for displaying at least one of the type, pressure, temperature and density of the fluid F. The display unit 20 includes a liquid crystal display unit for digitally displaying such information. The data output unit 21 is a unit that outputs at least one of the type, pressure, temperature, and density of the fluid F. The data output unit 21 is connected to a communication line for transmitting such information.

Next, the operation of the fluid type discriminating apparatus according to the first embodiment of the present invention will be described. FIG. 6 is a flowchart for explaining the operation of the fluid type determination device according to the first embodiment of the present invention. In step (hereinafter, referred to as S) 100, the ultrasonic transmitter 3 transmits an ultrasonic wave. When the control unit 18 controls the operation of the drive circuit 5, the ultrasonic transmission unit 3 transmits ultrasonic waves to the fluid F flowing in the measurement tube 1.

In S200, the ultrasonic wave receiving section 4 receives an ultrasonic wave. The ultrasonic wave that has passed through the fluid F is received by the ultrasonic wave receiving unit 4.

In S300, the sound speed measuring section 7 measures the sound speed. Based on the output signal output from the ultrasonic receiving unit 4, the sound speed of the ultrasonic wave passing through the fluid F is measured by the sound speed measuring unit 7.
Measure.

In S400, the fluid type determining section 9 determines the type of the fluid F. The fluid type determination unit 9 reads out fluid information corresponding to the sound speed information from the fluid information storage unit 8 based on the sound speed information output from the sound speed measurement unit 7, and reads the fluid F
Is determined.

In S500, the control unit 18 determines whether the pressure estimation mode has been selected. The control unit 18
It is determined whether or not the pressure estimation mode has been selected based on the output signal output from the mode switching unit 19. When the pressure estimation mode is selected, the process proceeds to S600, and when the pressure estimation mode is not selected, the process proceeds to S900.

In S600, the temperature measuring section 10 measures the temperature. When the control unit 18 controls the operation of the temperature measurement unit 10, the temperature measurement unit 10 measures the temperature of the fluid F in the measurement tube 1.

In S700, the pressure estimating unit 12 refers to the pressure information table. The pressure estimating unit 12 refers to the pressure information table stored in the pressure information storage unit 8.

In S800, the pressure estimating unit 12 estimates the pressure. The pressure estimating unit 12 estimates pressure of the fluid F by reading pressure information corresponding to the sound speed information and the fluid information from the pressure information table.

In S900, control unit 18 determines whether or not the temperature estimation mode has been selected. When the temperature estimation mode is selected, the process proceeds to S1000, and when the temperature estimation mode is not selected, the process proceeds to S1300.

In S1000, the pressure measuring section 13 measures the pressure. When the control unit 18 controls the operation of the pressure measurement unit 13, the pressure measurement unit 13 measures the pressure of the fluid F in the measurement pipe 1.

In S1100, temperature estimating section 15 refers to the temperature information table. The temperature estimating unit 15 refers to the temperature information table stored in the temperature information storage unit 14.

At S1200, temperature estimating section 15 estimates the temperature. The temperature estimating unit 15 reads out temperature information corresponding to the sound velocity information and the fluid information from the temperature information table, and estimates the temperature of the fluid F.

In S1300, control unit 18 determines whether or not density estimation mode A has been selected. When the density estimation mode A is selected, the process proceeds to S1400, and when the density estimation mode B is selected, the process proceeds to S1700.

In S1400, the temperature measuring section 10 measures the temperature. In S1500, the density estimating section 17 refers to the density information table A. In S1600, the density estimating unit 17 estimates the density. The density estimating unit 17 reads the density information corresponding to the sound velocity information and the fluid information from the density information table A, and estimates the density of the fluid F.

In S1700, the pressure measuring unit 13 measures the pressure. In S1800, the density estimating unit 17 refers to the density information table B. In S1900, the density estimating unit 17 estimates the density. The density estimating unit 17 reads the density information corresponding to the sound velocity information and the fluid information from the density information table B and estimates the density of the fluid F.

The fluid type discriminating apparatus according to the first embodiment of the present invention has the following effects. (1) In the first embodiment, the sound velocity of the ultrasonic wave passing through the fluid F is measured by the sound velocity measuring unit 7, and the type of the fluid F is determined by the fluid type determining unit 9. As a result, information on the physical properties of the fluid F, which serves as an index when indicating the properties of the fluid F, can be extracted and effectively used from the ultrasonic signal that has passed through the fluid F.

(2) In the first embodiment, the fluid information storage unit 8 stores the correlation between the type of the fluid F and the sound speed as fluid information, and stores the fluid information corresponding to the sound speed measured by the sound speed measuring unit 7. The type of the fluid F read from the fluid information storage unit 8 is determined by the fluid type determination unit 9. For this reason, the type of the fluid F flowing in the measurement tube 1 can be determined by measuring the sound speed of the ultrasonic wave that has passed through the fluid F. Also,
When a plurality of types of fluids flow through the measuring tube 1, the type of the current flowing fluid can be determined, and when the fluid F flowing through the measuring tube 1 changes from one fluid to another fluid, A change in the type of F can be detected.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
It is a lineblock diagram of a flow meter concerning an embodiment. In the following, FIG.
The same reference numerals are given to the same parts as those shown in FIG. The flow meter 22 is a device that measures the flow rate of the fluid F flowing in the measurement tube 1. The flow meter 22 is an ultrasonic vortex flow meter that detects the frequency of a vortex generated in the measurement tube 1 by ultrasonic waves. The flow meter 22 includes the measuring tube 1 and
The apparatus includes a fluid type determination device 2, a vortex generator 23, a signal processing circuit 24, and a flow rate calculation unit 25.

The vortex generator 23 is a column that generates a vortex in the measuring tube 1. The signal processing circuit 24 is a circuit that performs a predetermined process on an output signal output from the ultrasonic receiving unit 4.
The signal processing circuit 24 includes a circuit for converting a pulse train signal proportional to the frequency of the vortex. Flow rate calculator 25
Is a part for calculating the flow rate of the fluid F based on the reception result of the ultrasonic receiving unit 4.

Next, the operation of the flow meter according to the second embodiment of the present invention will be described. When the fluid F flows in the measuring tube 1,
Vortices are alternately discharged to the downstream side of the vortex generator 23, and the measuring tube 1
A meandering flow occurs in the flow, and this flow reverses direction in synchronization with the discharge of the vortex. As a result, the ultrasonic wave passing through the fluid F repeats acceleration and deceleration, and the sound speed of the ultrasonic wave changes periodically, and the arrival time at the ultrasonic receiver 4 changes. The flow rate calculation unit 25 detects the vortex based on frequency modulation (FM modulation) proportional to the cycle of the vortex, and calculates the flow rate of the fluid F.

The flow meter according to the second embodiment of the present invention has the following effects. In the second embodiment, a fluid type determining device 3 for determining the type of the fluid F is provided. For this reason, in addition to the flow rate measurement function for measuring the flow rate of the fluid F, a fluid type determination function, a temperature measurement function, and the like can be added. In addition, since the ultrasonic wave transmitting unit 3 and the ultrasonic wave receiving unit 4 for measuring the flow rate can also be used for discriminating the fluid type, a compact device with a simple configuration can be provided.

The present invention is not limited to the embodiment described above, but various modifications or changes can be made as described below, and these are also within the scope of the present invention. (1) In the first embodiment, a case has been described as an example in which all of the fluid type determination function, the temperature measurement function, the pressure measurement function, and the like are provided, but a device configuration in which these functions are arbitrarily combined or a single device It may be configured. In addition, this first
In the embodiment, the pressure information table or the like prepared in advance as a database has been described as an example. However, the pressure may be calculated and estimated from the sound speed information and the temperature information by an arithmetic expression.

(2) In the second embodiment, the case where the fluid type discriminating function is added to the ultrasonic vortex flowmeter has been described as an example, but the present invention is not limited to this. For example, ultrasonic waves pass obliquely across the fluid in the measurement tube to measure the difference in the reciprocation of the propagation time, and a propagation time difference type ultrasonic flow meter that measures the flow rate of the fluid, or the ultrasonic wave in the fluid in the measurement tube The present invention can also be applied to a Doppler ultrasonic flowmeter that transmits a sound wave, reflects ultrasonic waves from the fluid, and measures the flow rate of the fluid using the Doppler effect.

[0058]

As described above, according to the present invention, the type of the fluid is determined by measuring the sound velocity of the ultrasonic wave passing through the fluid, so that information on the physical properties of the fluid can be effectively used. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a fluid type determination device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining a pressure information table stored in a pressure information storage unit of the fluid type identification device according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a temperature information table stored in a temperature information storage unit of the fluid type identification device according to the first embodiment of the present invention.

FIG. 4 is a diagram for explaining a density information table A stored in a density information storage unit of the fluid type identification device according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining a density information table B stored in a density information storage unit of the fluid type identification device according to the first embodiment of the present invention.

FIG. 6 is a flowchart for explaining the operation of the fluid type determination device according to the first embodiment of the present invention.

FIG. 7 is a configuration diagram of a flow meter according to a second embodiment of the present invention.

FIG. 8 is a configuration diagram of a conventional ultrasonic vortex flowmeter.

FIG. 9 is a configuration diagram of a vortex detector of a conventional ultrasonic vortex flowmeter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Measuring pipe 2 Fluid type discriminating device 3 Ultrasonic transmitting unit 4 Ultrasonic receiving unit 7 Sound velocity measuring unit 8 Fluid information storage unit 9 Fluid type discriminating unit 10 Temperature measuring unit 11 Pressure information storing unit 12 Pressure estimating unit 13 Pressure measuring unit 14 Temperature information storage unit 15 Temperature estimation unit 16 Density information storage unit 17 Density estimation unit 20 Display unit 22 Flow meter 25 Flow rate calculation unit F Fluid

Claims (12)

[Claims] 1. An apparatus for determining a type of a fluid, comprising: an ultrasonic transmitter for transmitting an ultrasonic wave to the fluid; an ultrasonic receiver for receiving an ultrasonic wave passing through the fluid; A sound speed measuring unit that measures a sound speed of an ultrasonic wave passing through the fluid based on a reception result of the ultrasonic receiving unit; and a fluid type that determines a type of the fluid based on a measurement result of the sound speed measuring unit. A fluid type determination device comprising: a determination unit. 2. The fluid type discrimination device according to claim 1, further comprising: a fluid information storage unit that stores a correlation between the sound speed and the type of the fluid as fluid information, wherein the fluid type discrimination unit includes the fluid speed. Reading the fluid information corresponding to the above from the fluid information storage unit to determine the type of the fluid, wherein: 3. The fluid type determination device according to claim 2, wherein the fluid type determination unit detects a change in the type of the fluid flowing in the measurement tube when a plurality of types of fluid flow in the measurement tube. A fluid type discriminating device characterized by the following. 4. One of claims 1 to 3
In the fluid type determination device according to the item, a temperature measuring unit that measures the temperature of the fluid, and a pressure that estimates a pressure of the fluid based on the type of the fluid and the sound velocity when the temperature is constant. A fluid type discriminating device, comprising: an estimating unit. 5. The fluid type determination device according to claim 4, further comprising: a pressure information storage unit that stores a correlation between the sound speed and the pressure as pressure information for each type of the fluid, wherein the pressure estimating unit is Reading out the pressure information corresponding to the type of the fluid and the sound velocity from the pressure information storage unit to estimate the pressure, wherein: 6. Any one of claims 1 to 3
In the fluid type determination device according to the item, a pressure measurement unit that measures the pressure of the fluid, and a temperature that estimates a temperature of the fluid based on the type of the fluid and the sound velocity when the pressure is constant. A fluid type discriminating device, comprising: an estimating unit. 7. The fluid type determination device according to claim 6, further comprising: a temperature information storage unit that stores a correlation between the sound speed and the temperature as temperature information for each type of the fluid, wherein the temperature estimating unit includes: Reading out the temperature information corresponding to the type of the fluid and the sound velocity from the temperature information storage unit to estimate the temperature. 8. Any one of claims 1 to 3
In the fluid type determination device according to the item, a temperature measuring unit that measures the temperature of the fluid, and a density that estimates a density of the fluid based on the type of the fluid and the sound velocity when the temperature is constant. A fluid type discriminating device, comprising: an estimating unit. 9. Any one of claims 1 to 3
In the fluid type determination device according to the item, a pressure measuring unit that measures a pressure of the fluid, and a density that estimates a density of the fluid based on the type of the fluid and the sound velocity when the pressure is constant. A fluid type discriminating device, comprising: an estimating unit. 10. The fluid type discriminating apparatus according to claim 8, further comprising: a density information storage unit that stores a correlation between the sound velocity and the density as density information for each type of the fluid. A density estimating unit that reads out the density information corresponding to the type of the fluid and the sound velocity from the density information storage unit and estimates the density; 11. The fluid type identification device according to claim 1, wherein at least one of information of the type of the fluid, the pressure, the temperature, or the density is displayed. A fluid type discriminating device, comprising: 12. A flow meter for measuring a flow rate of a fluid flowing through a measurement pipe, wherein the fluid type discriminating apparatus according to claim 1 and reception of the ultrasonic receiving unit. A flow rate calculating unit configured to calculate a flow rate of the fluid based on a result.