JP6221624B2 - Fluid type discrimination device and fluid type discrimination method - Google Patents

Description

  The present invention relates to a fluid type discriminating apparatus and a fluid type discriminating method capable of easily and accurately discriminating various types of fluid flowing in a pipe.

  In the ground, gas pipes for supplying city gas and pipes such as water and sewage pipes are buried. And when construction is performed in a place where the pipe is buried, there is a case where these pipes are exposed and it is unclear what kind of the exposed pipe is. In such a case, the type of fluid flowing through the inside of the pipe, for example, the type of fluid such as city gas, water, or air, is determined to determine the type of the exposed pipe, and appropriate measures are taken for each pipe type. There is a need.

  As a conventional fluid type discriminating method for discriminating the type of fluid in a pipe, there is a method of providing a perforation in the pipe and extracting the internal fluid by the perforation. In addition, there is a method of using a neutron moisture meter as another fluid type discrimination method for the piping. This method can discriminate the fluid type without breaking the piping. Furthermore, as described in Patent Document 1, as another fluid type discrimination method for other piping, there is a method for judging the fluid type based on the transmission intensity of ultrasonic waves.

Japanese Patent Laid-Open No. 11-94613

  However, in the fluid type discrimination method in which the internal fluid is extracted by perforation and the type of fluid in the pipe is discriminated, the pipe needs to be restored after the perforation is blocked after the fluid type of the pipe is discriminated, which takes time and labor.

  Also, in the fluid type discrimination method that discriminates the type of fluid in the pipe using a neutron moisture meter, only the presence or absence of water can be determined, so the fluid that can be determined is limited, and sufficient fluid type determination cannot be performed.

  Furthermore, in the fluid type discrimination method described in Patent Document 1 that discriminates the type of fluid in the pipe using the ultrasonic transmission intensity, it is necessary to provide an ultrasonic probe in the pipe. Complex piping work is required.

  The present invention has been made in view of the above, and an object of the present invention is to provide a fluid type discriminating apparatus and a fluid type discriminating method capable of easily and accurately discriminating various types of fluid flowing in a pipe. To do.

  In order to solve the above-described problems and achieve the object, a fluid type discriminating apparatus according to the present invention transmits / receives ultrasonic waves to / from the fluid in the pipe from one ultrasonic probe installed on the outer wall of the pipe. The sound velocity of the fluid is obtained based on the propagation time of the ultrasonic wave propagated in the fluid and the inner diameter of the pipe measured by the time measuring unit that measures the time from transmission to reception of the fluid, and the correspondence between the sound velocity and the fluid type A fluid type discriminating apparatus for discriminating the type of fluid based on a relationship, wherein the ultrasonic probe installs an ultrasonic transducer on a surface parallel to a contact surface of the pipe and transmits the ultrasonic wave. A wedge that vertically enters the fluid, and the time measurement unit includes a first time from transmission of an ultrasonic wave to reception of a reflected wave reflected from an interface between a pipe inner wall and the fluid, and the fluid. At the interface between the pipe inner wall on the opposite side of the pipe and the fluid Characterized in that on the basis of a second time until receiving the reflected wave Isa measuring the propagation time.

  In the fluid type discriminating apparatus according to the present invention, in the above invention, the time measuring unit is a third unit from the transmission of the ultrasonic wave to the reception of the reflected wave reflected from the interface between the wedge and the pipe outer wall. Time is obtained, and the pipe inner diameter is obtained based on the third time, the input pipe outer diameter, and the input sound velocity of the pipe material.

  The fluid type discriminating apparatus according to the present invention further includes a storage unit that stores a correspondence relationship between the piping material and the sound velocity of the piping material in the above-described invention, and based on the correspondence relationship, A speed of sound is obtained, and the inner diameter of the pipe is obtained based on the third time, the input pipe outer diameter, and the speed of sound of the pipe material.

  Moreover, the fluid type discriminating apparatus according to the present invention is characterized in that, in the above invention, an ultrasonic absorber is installed in contact with the outer wall of the pipe around a portion where the wedge and the outer wall of the pipe are in contact with each other.

  In the fluid type discriminating apparatus according to the present invention as set forth in the invention described above, the ultrasonic absorber is characterized in that tungsten is mixed in a base material.

  The fluid type discriminating apparatus according to the present invention is characterized in that, in the above invention, the ultrasonic absorber is processed into a sheet by mixing a magnetic material with a base material.

  In addition, the fluid type discrimination method according to the present invention is a time measurement in which ultrasonic waves are transmitted / received to / from the fluid in the pipe from one ultrasonic probe installed on the outer wall of the pipe and the time from transmission to reception of the ultrasonic wave is measured. A fluid type discrimination method for discriminating the type of fluid based on a propagation time of ultrasonic waves propagated in the fluid measured by a section and an inner diameter of a pipe, and ultrasonic waves are formed on a surface parallel to a surface in contact with the pipe A transmission / reception step in which an ultrasonic wave is vertically incident on the fluid by installing a vibrator; a first time from reception of an ultrasonic wave to reception of a reflected wave reflected from an interface between a pipe inner wall and the fluid; and A propagation time measuring step for measuring the propagation time based on a second time until a reflected wave that has crossed the fluid and is reflected at the interface between the pipe inner wall opposite to the pipe and the fluid is received; Arrangement for obtaining the inner diameter of the pipe Fluid type determination for determining the fluid type based on the correspondence relationship between the sound velocity and the fluid type, and an inner diameter acquisition step, a sound velocity calculation step for obtaining the sound velocity of the fluid based on the propagation time and the pipe inner diameter And a step.

  Further, in the fluid type discrimination method according to the present invention, in the above invention, the propagation time measurement step may be a process from transmission of ultrasonic waves to reception of a reflected wave reflected from the interface between the wedge and the pipe outer wall. 3 hours, and the pipe inner diameter obtaining step is based on the correspondence between the third time, the input pipe outer diameter, and the input pipe material and the pipe material and the sound velocity of the pipe material. The inner diameter of the pipe is obtained based on the sound velocity of the pipe material determined in (1).

  According to this invention, ultrasonic waves are transmitted / received to / from the fluid in the pipe from one ultrasonic probe installed on the outer wall of the pipe, and measured by the time measuring unit that measures the time from transmission to reception of the ultrasonic wave. Obtaining the sound speed of the fluid based on the propagation time of ultrasonic waves propagated in the fluid and the inner diameter of the pipe, and determining the type of the fluid based on the correspondence between the sound speed and the fluid type, The ultrasonic probe has a wedge that installs an ultrasonic transducer on a plane parallel to a contact surface of the pipe and makes the ultrasonic wave perpendicularly incident on the fluid, and the time measurement unit transmits ultrasonic waves. A first time from when the reflected wave reflected from the interface between the pipe inner wall and the fluid is received, and the reflection reflected at the interface between the pipe inner wall opposite to the pipe and the fluid across the fluid The propagation time is measured based on the second time until the wave is received. It has to. As a result, it is possible to easily and accurately discriminate various types of fluid flowing in the pipe.

FIG. 1 is a schematic diagram showing the overall configuration of a fluid type discriminating apparatus according to an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating a state of a reflected wave of an ultrasonic signal emitted from an ultrasonic transducer toward a pipe. FIG. 3 is a time chart when the ultrasonic transducer receives a reflected wave with respect to the ultrasonic signal transmitted by the ultrasonic transducer. FIG. 4 is a flowchart showing a fluid type determination processing procedure by the fluid type determination unit. FIG. 5 is a detailed flowchart showing a procedure for acquiring the inner diameter of the pipe. FIG. 6 is a schematic diagram illustrating an example of an interference wave transmitted by multiple reflection in a pipe. FIG. 7 is a schematic diagram illustrating an example of an interference wave that is multiple-reflected in a pipe and reflected by a flange. FIG. 8 is a schematic diagram showing a state in which interference waves transmitted by multiple reflection in the pipe are attenuated by the ultrasonic absorber. FIG. 9 is a schematic diagram showing an example in which an ultrasonic absorber is provided so as to cover a range of half or less of the circumference of a pipe.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

(overall structure)
FIG. 1 is a schematic diagram showing the overall configuration of a fluid type discriminating apparatus according to an embodiment of the present invention. In FIG. 1, the fluid type discriminating apparatus 1 discriminates the type of the fluid 103 that flows in the pipe 100.

  As shown in FIG. 1, the fluid type determination device 1 includes a measurement unit 10 and a device body 20. The measurement unit 10 includes an ultrasonic transducer 11 and a wedge 12. The ultrasonic transducer 11 and the wedge 12 are such that the lower surface of the wedge 12 is in contact with the pipe outer wall 101 and the upper surface of the wedge 12 is parallel to the installation surface on which the ultrasonic transducer 11 is installed. The structure is such that ultrasonic waves are vertically applied to and transmitted through the contact surface of the outer wall 101. Note that an ultrasonic connection medium 13 that functions as an ultrasonic coupler is provided at the lower portion of the wedge 12 in order to eliminate the presence of air having poor ultrasonic transmission between the lower portion of the wedge 12 and the pipe outer wall 101. Yes. The ultrasonic connection medium 13 is realized by purified water, alcohol, silicon, or the like. The ultrasonic connection medium 13 may be in any form such as liquid, gel or rubber. The ultrasonic transducer 11, the wedge 12, and the ultrasonic connection medium 13 form an ultrasonic probe 14. In addition, an ultrasonic absorber 15 that absorbs interference waves transmitted by multiple reflection of the thick part of the pipe 100 is disposed on the pipe outer wall 101 around the ultrasonic probe 14. The measurement unit 10 includes an ultrasonic probe 14 and an ultrasonic absorber 15.

  The apparatus main body 20 includes a transmission unit 21, a reception unit 22, a switch 23, a time measurement unit 24, a fluid type determination unit 25, a storage unit 26, and an input / output unit 27, and each unit is connected to a control unit 28. The switch 23 is electrically connected to the ultrasonic transducer 11.

  The transmitter 21 generates an ultrasonic transmission pulse electrical signal that causes the ultrasonic transducer 11 to generate an ultrasonic signal, and outputs the electrical signal to the ultrasonic transducer 11 via the switch 23. The ultrasonic transducer 11 generates an ultrasonic signal by an ultrasonic transmission pulse electrical signal. The generated ultrasonic signal passes through the pipe 100 through the wedge 12 and enters the fluid 103. The ultrasonic signal that has entered the fluid 103 is reflected by the pipe inner wall 102 opposite to the position where the ultrasonic probe 14 is disposed, makes one round trip through the fluid 103, passes through the pipe 100 again, and passes through the wedge 12. Then, it enters the ultrasonic transducer 11. The ultrasonic signal incident on the ultrasonic transducer 11 is converted into an ultrasonic reception pulse electric signal by the ultrasonic transducer 11 and output to the receiving unit 22. The control unit 28 connects the switch 23 to the transmitting unit 21 side only when transmitting an ultrasonic transmission pulse electric signal, and when receiving the ultrasonic reception pulse electric signal after transmitting the ultrasonic transmission pulse electric signal, the control unit 28 connects the switch 23 to the transmission unit 21 side. Is connected to the receiving unit 22 side.

  The time measurement unit 24 transmits the transmission time of the ultrasonic transmission pulse electrical signal transmitted by the transmission unit 21 (the time when the ultrasonic signal is transmitted from the ultrasonic transducer 11) and the ultrasonic reception pulse electrical signal received by the reception unit 22. Based on the reception time (the time at which the ultrasonic transducer 11 receives the reflected wave of the ultrasonic signal), the propagation time for the ultrasonic signal incident perpendicularly to the pipe 100 to reciprocate in the fluid 103 is calculated. measure.

  Here, as shown in FIG. 2, there are three reflected waves of the ultrasonic signal emitted from the ultrasonic transducer 11, Sa, Sb, and Sc. The reflected wave Sa is a part of the ultrasonic signal emitted from the ultrasonic transducer 11 that is reflected at the interface between the wedge 12 and the pipe outer wall 101 and returns to the ultrasonic transducer 11. The reflected wave Sb is a part of the ultrasonic signal transmitted through the interface between the wedge 12 and the pipe outer wall 101 that is reflected at the interface between the pipe inner wall 102 and the fluid 103 and returns to the ultrasonic transducer 11. is there. The reflected wave Sc passes through the interface between the pipe inner wall 102 and the fluid 103, passes through the fluid 103, is reflected by the opposite pipe inner wall 102, and makes one round trip in the fluid 103. 100 passes through the wedge 12 and returns to the ultrasonic transducer 11.

  FIG. 3 is a time chart in which the ultrasonic transducer 11 receives the reflected waves Sa, Sb, and Sc with respect to the ultrasonic signal S transmitted by the ultrasonic transducer 11. As shown in FIG. 3, the time ta is the time (third time) from when the ultrasonic transducer 11 transmits the ultrasonic signal S until the reflected wave Sa is received. The time tb is a time (first time) from when the ultrasonic transducer 11 transmits the ultrasonic signal S to when the reflected wave Sb is received. The time tc is a time (second time) from when the ultrasonic transducer 11 transmits the ultrasonic signal S until the reflected wave Sc is received.

As described above, the time measuring unit 24 obtains the propagation time tf in which the ultrasonic signal incident perpendicularly to the pipe 100 travels once in the fluid 103 by the following equation (1). That is,
tf = tc−tb (1)

(Determination of fluid type when pipe inner diameter Di is known)
The fluid type discriminating unit 25 obtains the sound velocity of the fluid 103 by dividing twice the pipe inner diameter Di by the propagation time tf obtained by the time measuring unit 24. Here, the memory | storage part 26 hold | maintains the sonic speed versus fluid kind relationship information DT1. The sound speed / fluid type relationship information DT1 indicates the relationship between the specific sound speed determined by the type of fluid and the fluid type. For example, when the fluid type is city gas, the city gas contains methane as a main component, and the speed of sound is about 430 m / s. When the fluid type is water, the sound speed is about 1500 m / s. When the fluid type is air, the sound speed is about 340 m / s. On the other hand, the pipe inner diameter Di is a known value input from the input / output unit 27. The pipe inner diameter Di and the pipe outer diameter Do of the pipe 100 buried underground are standardized by JIS and the like, and the pipe inner diameter Di can be known by reading the standard notation of the pipe outer surface of the pipe 100 to be measured. . That is, the fluid type discriminating unit 25 obtains the sound speed of the fluid 103 by dividing twice the pipe inner diameter Di by the propagation time tf, and refers to the sound speed / fluid type relationship information DT1 for the obtained fluid type. Determine. The control unit 28 outputs the fluid type determined by the fluid type determination unit 25 from the input / output unit 27.

(Determination of fluid type when pipe inner diameter Di is unknown)
On the other hand, in old pipes and buried pipes, there are many cases where the standard notation becomes thin and cannot be read or the standard notation is buried and cannot be seen. There are also pipes without the standard notation itself. In such a case, the fluid type determination unit 25 estimates the pipe inner diameter Di using the time ta (third time), the pipe outer diameter Do, and the pipe material. If the pipe inner diameter Di can be estimated, the fluid type determination unit 25 can perform the fluid type determination process in the same manner as when the pipe inner diameter Di is known.

  The pipe outer diameter Do can be measured by digging up the pipe 100 about half. Further, the pipe material of the pipe 100 can be determined by the appearance. The pipe outer diameter Do and the pipe material are input from the input / output unit 27.

  The fluid type discriminating unit 25 obtains the sound speed of the pipe 100 with respect to the input pipe material based on the pipe material versus sound speed relation information DT2 held in the storage unit 26 in advance. For example, the pipe speed is about 6000 m / s for metals such as iron and stainless steel, the speed of sound is about 2300 m / s for polyvinyl chloride, which is plastic, and the pipe material is polyethylene, which is plastic. On the other hand, the sound speed is about 1900 m / s. It is easy to visually discriminate whether the pipe material is metal or plastic. For this reason, the piping material versus sonic relationship information DT2 holds the sonic velocity Cp of the piping 100 as 6000 m / s when the piping material is metal, and the sonic velocity Cp of the piping 100 as 2000 m / s when the piping material is plastic. Is done.

The fluid type discriminating unit 25 uses the pipe outer diameter Do, the sonic velocity Cp of the pipe 100, the time tb, and the time ta to obtain the pipe inner diameter Di by the following equation (2). That is,
Di = Do-Cp (tb-ta) (2)
Here, the value of Cp (tb−ta) corresponds to twice the thickness of the pipe 100.

  By the way, in Formula (2), since the sonic velocity Cp of the pipe 100 is estimated, there is an error in the value of the pipe inner diameter Di. However, for example, if the thickness of the pipe 100 is estimated from the pipe outer diameter Do, the thickness is 1.5 to 9 mm for the metal pipe and the thickness is 2 to 2 for the plastic pipe in the case of the diameter 50A (50 mm). The deviation is large and the error is large. On the other hand, since the deviation due to the difference in the pipe material of the sonic velocity Cp of the pipe 100 can be visually discriminated whether the pipe material is metal or plastic, the sonic velocity Cp of the pipe 100 is estimated as described above. Can estimate the wall thickness more accurately. As a result, in this embodiment, a highly accurate pipe inner diameter Di can be obtained.

(Fluid type discrimination processing)
Here, based on the flowchart shown in FIG.4 and FIG.5, the fluid type discrimination | determination processing procedure by the fluid type discrimination | determination part 25 is demonstrated. First, as shown in FIG. 4, the fluid type discriminating unit 25 acquires the times ta, tb, and tc from the time measuring unit 24 (step S101). Thereafter, the propagation time tf is calculated by the equation (1) (step S102). Thereafter, the pipe inner diameter Di that is input by the input / output unit 27 or the pipe inner diameter Di that is calculated by the equation (2) is acquired (step S103).

  Thereafter, the fluid type discriminating unit 25 calculates the sound speed of the fluid 103 by dividing twice the pipe inner diameter Di by the propagation time tf (step S104). Further, the fluid type discriminating unit 25 discriminates the fluid type corresponding to the obtained sonic velocity using the sonic speed vs. fluid type relation information DT1 (step S105), and outputs the fluid type from the input / output unit 27 (step S106). ), This process is terminated.

  FIG. 5 is a detailed flowchart of the procedure for acquiring the pipe inner diameter Di shown in step S103. As shown in FIG. 5, the fluid type determination unit 25 first determines whether or not the pipe inner diameter Di has been input by the input / output unit 27 (step S <b> 201). If the pipe inner diameter Di has already been input (step S201, Yes), the process directly returns to step S103.

  On the other hand, if the pipe inner diameter Di has not been input (No at Step S201), the pipe outer diameter Do and the pipe material input from the input / output unit 27 are acquired (Step S202). Thereafter, the fluid type discriminating unit 25 determines the sonic velocity Cp of the pipe 100 corresponding to the acquired pipe material based on the pipe material versus sonic speed relation information DT2 (step S203). Thereafter, the fluid type determination unit 25 calculates the pipe inner diameter Di using the equation (2) (step S204), and returns to step S103.

(Ultrasonic absorber)
By the way, a part of the ultrasonic signal incident from the contact surface between the wedge 12 and the pipe outer wall 101 is transmitted with multiple reflections using the pipe 100 as a waveguide. For example, as shown in FIG. 6, an interference wave transmitted through multiple reflections in the pipe 100 may return to the ultrasonic transducer 11 after several turns in the pipe 100. FIG. 7 is a longitudinal sectional view of the pipe 100. As shown in FIG. 7, the interference wave transmitted through the pipe 100 is reflected by the flange 130 provided at the end of the pipe 100 in the axial direction or the like. In some cases, the sound wave may be returned to the sonic transducer 11. The solid line shown in FIG. 7 represents the forward ultrasonic signal, and the broken line represents the ultrasonic signal that is reflected by the flange 130 and returns to the ultrasonic transducer 11. These interference waves overlap with the reflected wave Sc shown in FIG. 3 in time, or cause a measurement error with respect to the time tc when it is in the vicinity of the reception time of the reflected wave Sc.

  Therefore, as shown in FIGS. 1 and 8, an ultrasonic absorber 15 is provided on the surface of the pipe outer wall 101 around the ultrasonic probe 14. The ultrasonic absorber 15 is made of a material whose base material attenuates ultrasonic waves such as rubber and clay. As shown in FIG. 8, every time the interference wave is multiple-reflected in the pipe 100, a part of the interference wave is transmitted to the ultrasonic absorber 15 and attenuates and disappears in the ultrasonic absorber 15. Therefore, most of the interference wave disappears while passing through the pipe portion where the ultrasonic absorber 15 and the pipe outer wall 101 are in contact with each other. For this reason, it is possible to suppress a measurement error of the reflected wave Sc that occurs when the interference wave overlaps with the reception point of the reflected wave Sc or exists in the vicinity. The ultrasonic absorber 15 is preferably disposed not only in the circumferential direction of the pipe 100 but also in the axial direction of the pipe 100 so as to surround the four sides of the ultrasonic probe 14. Thereby, the interference wave reflected by the flange 130 shown in FIG. 7 can be absorbed.

  In addition, as shown in FIG. 9, it is desirable for the ultrasonic absorber 15 to cover a range of half or less of the circumference of the pipe 100. In this case, if the pipe 100 is dug up by about half, the measurement of the pipe outer diameter Do, the installation of the ultrasonic absorber 15 and the installation of the measurement unit 10 can be easily performed.

  In addition, when the pipe 100 is a metal, the ultrasonic absorber 15 is preferably mixed with a base material such as rubber or clay to increase the specific gravity and increase the interference wave absorption effect. This is because if the specific gravity between the pipe 100 and the ultrasonic absorber 15 is close, the ratio of the interference wave transmitted to the ultrasonic absorber 15 increases and the effect of ultrasonic absorption can be increased. In general, the specific gravity of rubber or clay serving as the base material of the ultrasonic absorber 15 is about 1-2, and there is a large difference with respect to the specific gravity of the metal pipe being about 8, and the specific gravity of tungsten is about By mixing 19 tungsten, the specific gravity of the ultrasonic absorber 15 can be brought close to the metal pipe.

  Furthermore, when the pipe 100 is a magnetic material such as iron or steel, it is preferable to mix the magnetic material with the ultrasonic absorber 15, process it into a sheet shape, and magnetize it to obtain a magnet sheet. By making the ultrasonic absorber 15 into a sheet shape, the ultrasonic absorber 15 can be easily installed on the pipe 100. Further, when iron is used as the magnetic material, the specific gravity is as small as 8, so it is preferable to mix tungsten having a large specific gravity together.

  In the embodiment described above, an ultrasonic signal is incident perpendicularly to the pipe outer wall 101 of the pipe 100 from one ultrasonic probe 14. As a result, the fluid 103 in various types of piping can be discriminated with a structure that can be easily installed without breaking the piping 100.

  In a configuration that uses a pair of ultrasonic probes that inject an ultrasonic signal obliquely into the pipe as in a conventional ultrasonic probe, and determines the speed of sound by measuring the propagation time in the fluid, the configuration Is complicated. Further, in the conventional ultrasonic probe, since the ultrasonic signal is obliquely incident on the pipe, the reflected waves Sa and Sb cannot be obtained as in the present embodiment, and the wall thickness of the pipe 100 is not obtained. Therefore, the fluid type is determined with low accuracy. Further, in the conventional ultrasonic probe, the ultrasonic signal is obliquely incident on the pipe, and the incident angle setting from the pipe to the fluid changes according to the sound velocity in the fluid in accordance with Snell's law. Therefore, this incident angle cannot be specified if the fluid in the pipe is unknown. As a result, since it is not possible to specify the optimum mounting interval between the pair of ultrasonic probes, measurement errors are likely to occur.

  In contrast, in the above-described embodiment, the propagation time tf through which the ultrasonic signal passes through the fluid 103 can be accurately measured, and the pipe inner diameter Di can be easily estimated even when the thickness of the pipe 100 is unknown. The sound speed of the fluid can be obtained with high accuracy, and as a result, the fluid type with high accuracy can be determined.

  Furthermore, in the above-described embodiment, since the interference wave that wraps around the pipe 100 due to multiple reflection can be reduced by the ultrasonic absorber 15, the influence of the interference wave can be suppressed, and a more accurate propagation time tf can be obtained. Measurement is possible, and as a result, a highly accurate fluid type can be identified.

DESCRIPTION OF SYMBOLS 1 Fluid type discrimination | determination apparatus 10 Measurement part 11 Ultrasonic transducer 12 Wedge 13 Ultrasonic connection medium 14 Ultrasonic probe 15 Ultrasonic absorber 20 Apparatus main body 21 Transmission part 22 Reception part 23 Switch 24 Time measurement part 25 Fluid type discrimination | determination 26 Storage unit 27 Input / output unit 28 Control unit 100 Piping 101 Piping outer wall 102 Piping inner wall 103 Fluid 130 Flange Cp Sonic speed Pi Piping inner diameter Do Piping outer diameter DT1 Sonic vs. fluid type relation information DT2 Piping material vs. sonic relation information S Ultrasonic signal Sa, Sb, Sc Reflected wave ta, tb, tc Time tf Propagation time

Claims (6)

Ultrasound propagated in the fluid measured by the time measurement unit that transmits and receives ultrasound to and from the fluid in the pipe from one ultrasonic probe installed on the pipe outer wall and measures the time from transmission to reception of the ultrasonic wave A fluid type discriminating device for obtaining a sound speed of the fluid based on a propagation time of a sound wave and a pipe inner diameter, and discriminating the type of the fluid based on a correspondence relationship between the sound speed and a fluid type,
The ultrasonic probe has a wedge for installing an ultrasonic vibrator on a plane parallel to a contact surface of the pipe and allowing the ultrasonic wave to enter the fluid vertically.
The time measuring unit includes a first time from transmission of an ultrasonic wave to reception of a reflected wave reflected from an interface between a pipe inner wall and the fluid, and a pipe inner wall on the opposite side of the pipe across the fluid. A second time until receiving a reflected wave reflected at the interface with the fluid, and a third time until receiving a reflected wave reflected from the interface between the wedge and the outer wall of the pipe from the transmission of ultrasonic waves; And measuring the propagation time based on the first time and the second time, and based on the third time, the input pipe outer diameter, and the input sound velocity of the pipe material. A fluid type discriminating apparatus characterized in that the pipe inner diameter is obtained. A storage unit for storing a correspondence relationship between the piping material and a sound velocity of the piping material; obtaining a sound velocity of the piping material based on the correspondence; the third time; and the input pipe outer diameter If, on the basis of the sound velocity of the pipe material, fluid type determination apparatus according to claim 1, characterized in that determining the pipe inner diameter. The fluid type discriminating apparatus according to claim 1 or 2 , wherein an ultrasonic absorber is installed in contact with the pipe outer wall around a place where the wedge and the pipe outer wall are in contact with each other. The fluid type discriminating apparatus according to claim 3 , wherein the ultrasonic absorber has a base material mixed with tungsten. 5. The fluid type discriminating apparatus according to claim 3, wherein the ultrasonic absorber is processed into a sheet by mixing a magnetic material with a base material. Ultrasound propagated in the fluid measured by the time measurement unit that transmits and receives ultrasound to and from the fluid in the pipe from one ultrasonic probe installed on the pipe outer wall and measures the time from transmission to reception of the ultrasonic wave A fluid type discrimination method for discriminating the type of fluid based on the propagation time of sound waves and the inner diameter of a pipe,
A transmission / reception step in which an ultrasonic transducer is installed on a plane parallel to the contact surface of the pipe and an ultrasonic wave is vertically incident on the fluid; and
A first time from transmission of an ultrasonic wave to reception of a reflected wave reflected from an interface between a pipe inner wall and the fluid; and at an interface between the pipe inner wall on the opposite side of the pipe and the fluid across the fluid. A propagation time measuring step for measuring the propagation time based on a second time until the reflected wave is received;
A pipe inner diameter obtaining step for obtaining a pipe inner diameter of the pipe;
A sound velocity calculating step for obtaining a sound velocity of the fluid based on the propagation time and the pipe inner diameter;
A fluid type discriminating step for discriminating the type of fluid based on the correspondence between the speed of sound and the fluid type;
Only including,
The propagation time measurement step obtains a third time from transmission of ultrasonic waves until reception of a reflected wave reflected from the interface between the wedge and the pipe outer wall,
The pipe inner diameter acquisition step is a pipe determined based on a correspondence relationship between the pipe material and the sound velocity of the pipe material with respect to the third time, the input pipe outer diameter, and the input pipe material. A fluid type discrimination method characterized in that the pipe inner diameter is obtained based on the sound velocity of a material .

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