JPWO2017090390A1 - Pipe thickness measuring apparatus and method using ultrasonic waves - Google Patents

Abstract

Provided are a pipe thickness measuring apparatus and method using ultrasonic waves of a stand-alone type (cableless) for measuring the thickness of a pipe having a structural discontinuity from the inner surface. In a pipe thickness measuring apparatus using ultrasonic waves, a plurality of ultrasonic sensors that transmit / receive ultrasonic waves to / from a liquid in the pipe, a means for transmitting / receiving ultrasonic waves, and a plurality of reflected wave propagation times for each ultrasonic sensor And a means for calculating the pipe thickness using the propagation time of the ultrasonic wave incident substantially perpendicularly on the inner wall of the pipe.

Description

  The present invention relates to a pipe thickness measuring apparatus and method used in, for example, a plant.

  When piping for a power plant, chemical plant, etc. is laid for a long time, defects (thinning) occur on the inner surface. As this thinning progresses, there is a risk that the internal fluid that passes through the thick wall of the pipe and flows through the pipe, such as liquid and vapor, will leak to the outside. In order to avoid such leakage of internal fluid, it is necessary to grasp the state of thinning by regular non-destructive inspection of piping, and to take measures such as replacement and repair.

  As a nondestructive inspection means for nondestructive inspection of the thickness of a pipe, an ultrasonic thickness meter that measures the thickness of an inspection object is known. As the ultrasonic thickness meter, an ultrasonic sensor having a piezoelectric element capable of mutually converting electricity and sound is generally used. Install an ultrasonic sensor on the outer surface of the pipe, transmit ultrasonic waves (longitudinal waves and transverse waves) to the pipe to be inspected, and receive the ultrasonic waves reflected on the inner surface of the pipe with the same or another ultrasonic sensor to obtain the thickness of the pipe. Measure the thickness. Since this ultrasonic thickness gauge has a narrow inspection range, in order to inspect a wide range, it is necessary to inspect a plurality of locations along the pipe, which requires a long inspection time. In addition, the application may be difficult, for example, when the pipe is buried, when a heat insulating material is installed around the pipe, or when the pipe is doubled.

  For such a pipe, there is a pipe insertion type inspection device having an ultrasonic sensor, an electromagnetic sensor, or the like, which is used for actual use. However, when the distance to be inspected becomes long, there is a problem that the cable of the pipe insertion type inspection apparatus becomes long and the installation cost increases.

  On the other hand, a technique for measuring the thickness from the inner surface of a pipe without connecting a cable is disclosed. For example, Patent Document 1 discloses an in-tube insertion type ultrasonic flaw detection apparatus having an ultrasonic pulse generation / reception unit, a control unit, a recording unit, and the like inside the apparatus. Patent Document 2 discloses a measuring device in which electromagnetic ultrasonic probes are three-dimensionally arranged in a spherical measuring device main body and moved in a pipe. Patent Document 3 discloses a technique for measuring a water leak location, a water leak amount, and an air reservoir position by having an acoustic sensor in a sphere and detecting and recording a sound generated by a leak or an air reservoir in a pressure tube. Is disclosed.

JP 2011-75384 A JP 2005-290204 A WO2006 / 081671

  However, in the above Patent Documents 1 to 3, there is a problem that the pipe thickness cannot be measured for a pipe having a structural discontinuity portion such as a branch or a change in diameter.

  In Patent Document 1, the device structure is divided into a plurality of units such as a sensor unit, a pulsar receiver unit, and a power supply unit, and these are arranged and connected along the pipe axis direction. Thus, in the structure where the whole apparatus is long, there is a possibility that the discontinuous part (branch etc.) of the piping structure cannot be smoothly passed.

  In Patent Document 2, an electromagnetic ultrasonic probe is three-dimensionally arranged in a spherical measuring device main body, but the electromagnetic ultrasonic probe is an object that transmits and receives ultrasonic waves (in this case, the inner wall of a pipe). ) Must be close to the inner diameter of the pipe. Therefore, there is a problem that it is not possible to cope with a change in the diameter of the pipe, and there is a concern that the pipe cannot pass when there is a deposit on the inner wall of the pipe.

  Moreover, in patent document 3, although it has an acoustic sensor in a spherical body, it is not disclosed regarding the technique which measures the thickness of piping.

  The present invention has been made in view of the above, and provides a pipe thickness measuring apparatus and method using ultrasonic waves of an independent type (cableless) for measuring the thickness of a pipe having a discontinuous structure from the inner surface. The purpose is to do.

  In order to achieve the above object, a pipe thickness measuring apparatus according to the present invention includes a plurality of ultrasonic sensors that transmit and receive ultrasonic waves to and from the liquid in the pipe, and ultrasonic waves. The pipe thickness is calculated by using means for transmitting and receiving, means for measuring and recording a plurality of reflected wave propagation times for each ultrasonic sensor, and propagation time of ultrasonic waves that are incident substantially perpendicularly to the inner wall of the pipe. It has the means.

  In order to achieve the above object, a pipe thickness measuring method according to the present invention is a pipe thickness measuring method using ultrasonic waves, comprising: a pipe thickness measuring device comprising a plurality of ultrasonic sensors and means for transmitting and receiving ultrasonic waves. It is arranged so that it can move in the pipe, and the reflected wave propagation time is measured from the inside of the pipe by each ultrasonic sensor on the pipe thickness measuring device, and is incident substantially perpendicular to the inner wall of the pipe. The pipe thickness is calculated using the propagation time of ultrasonic waves.

  According to the present invention, it is possible to measure the thickness of a pipe having a structural discontinuity portion.

It is a figure which shows schematic structure of the pipe thickness measuring apparatus using the ultrasonic wave by Example 1 of this invention. It is a flowchart which shows operation | movement of the pipe thickness measuring apparatus using the ultrasonic wave by Example 1 of this invention. It is the figure explaining the mode of propagation of the ultrasonic wave transmitted from each ultrasonic sensor of the pipe thickness measuring device using the ultrasonic wave by Example 1 of the present invention. It is the figure which showed typically the received signal of the ultrasonic wave transmitted from the pipe thickness measuring apparatus using the ultrasonic wave by Example 1 of this invention. It is the figure explaining a mode that the piping thickness measuring apparatus using the ultrasonic wave by Example 1 of this invention moved the inside of piping. It is the figure which showed typically the display screen of the pipe thickness measurement result by the pipe thickness measuring apparatus using the ultrasonic wave by Example 1 of this invention. It is a flowchart which shows operation | movement of the pipe thickness measuring apparatus using the ultrasonic wave by Example 2 of this invention. It is the figure which showed typically the display screen of the pipe thickness measurement result by the pipe thickness measuring apparatus using the ultrasonic wave by Example 2 of this invention.

  Hereinafter, examples will be described with reference to the drawings.

  An embodiment of the present invention will be described below with reference to FIGS.

  FIG. 1 is a diagram schematically showing an overall configuration of a pipe thickness measuring apparatus using ultrasonic waves according to the present embodiment, along with pipes to be inspected.

  In FIG. 1, a pipe thickness measuring device 2 is output from an ultrasonic sensor 11, an ultrasonic transmission / reception unit 12 that drives the ultrasonic sensor 11 and receives a waveform signal from the ultrasonic sensor 11, and an ultrasonic transmission / reception unit 12. An ultrasonic wave propagation time measuring / recording means 14 for converting the waveform signal into a digital waveform signal and measuring and recording the ultrasonic wave propagation time, and a pipe thickness calculating means 15 for calculating the pipe thickness from the propagation time.

  A plurality of ultrasonic transmission sensors 11 are arranged around the pipe thickness measuring device 2 and connected to the ultrasonic transmission / reception means 12 by a coaxial cable or the like. The ultrasonic sensor 11 is composed of, for example, a piezoelectric element.

  The ultrasonic transmission / reception means 12 is connected to the ultrasonic propagation time measurement / recording means 14 by a digital cable, and applies a transmission waveform signal to the ultrasonic transmission sensor 11 under the control of the pipe thickness calculation means 15. Furthermore, the ultrasonic sensor 11 amplifies the received waveform signal from 11 and outputs the received waveform signal.

  The posture measuring means 13 is composed of a gyroscope or the like, and measures a relative change in the posture of the pipe thickness measuring device 2.

  The ultrasonic propagation time measuring / recording means 14 is composed of an A / D converter, a memory, etc., and records the received waveform data received by the ultrasonic transmission sensor 11.

  The pipe thickness calculation means 15 calculates the pipe thickness based on the received waveform data recorded by the ultrasonic propagation time measurement / recording means 14.

  It is appropriate that the pipe thickness measuring device 2 moves substantially on the central axis of the pipe 1, and the volume and mass should be adjusted so that the buoyancy is neutral with respect to the liquid 8. Although not shown, the pipe thickness measuring apparatus 2 is arranged around the pipe thickness measuring apparatus 2 by arranging a string-like elastic body having a thickness that does not affect the propagation of ultrasonic waves. Can be moved almost on the central axis.

  A pipe thickness measurement method using ultrasonic waves will be described below using the flowchart of FIG.

  In step S <b> 101, the pipe thickness measuring device 2 is put into the pipe 1.

  Next, in step S <b> 102, the ultrasonic transmission / reception unit 12 drives one of the ultrasonic transmission sensors 11 and receives the ultrasonic waves by the same ultrasonic transmission sensor 11.

  In step S103, the ultrasonic wave propagation time measurement / recording unit 14 records the ultrasonic reception waveform as digital waveform data.

  In step S104, the pipe thickness calculation means 15 calculates the thickness of the pipe.

Steps S <b> 102 to S <b> 104 are repeated for all the ultrasonic sensors 11. For example, as shown in FIG. 3, when 26 ultrasonic sensors 11 are arranged around the pipe thickness measuring device 2, the process is repeated for the 26 ultrasonic sensors 11. At this time, if there is an inner wall that faces the ultrasonic sensor 11 within the range of the directivity angle of the ultrasonic sensor 11, it is substantially perpendicular to the inner wall of the pipe 1 as shown by the ultrasonic wave 61 shown by the solid line. There is a propagation path incident on the. On the other hand, when there is no inner wall facing the ultrasonic sensor 11 within the range of the directivity angle of the ultrasonic sensor 11, the incident is perpendicular to the inner wall of the pipe 1 like the ultrasonic wave 62 indicated by a broken line. There is no route to do. FIG. 4 schematically shows each received signal. FIG. 4A shows the received signal 21 of the ultrasonic wave 61 incident substantially perpendicularly to the inner wall of the pipe 1, passing through the signal 21 a reflected on the surface of the inner wall of the pipe and the surface of the inner wall of the pipe 1. A signal 21b reflected on the outer wall of the pipe 1 is observed (21b may be repeatedly observed). The time difference (t _21b −t _21a ) between the signal 21a and the signal 21b corresponds to the pipe thickness of the part. On the other hand, FIG. 4B shows the reception signal 22 of the ultrasonic wave 62 that is not perpendicularly incident on the inner wall of the pipe 1 and no reflected wave is observed.

  Thus, the repetition of steps S102 to S104 for all the ultrasonic sensors 11 is repeated at a specific time interval. For example, as shown in FIG. 5, when the pipe thickness measuring device is inserted at the position shown in 2a, the pipe 1 is flowed until the distance L advances, and the pipe thickness measuring device is collected at the position shown in 2b, During this time, steps S102 to S104 are repeated.

  Finally, in step S106, the pipe thickness measuring device 2 is recovered from the pipe 1.

  FIG. 6 shows an example of a screen in which the pipe thickness data recorded in the collected pipe thickness measuring device 2 is displayed with the horizontal axis as the pipe axis direction distance L (m) and the vertical axis as the ultrasonic sensor channel. It is shown. Of the 26 ultrasonic sensors 11, there are pipe thickness measurement data in the received waveforms of the eight ultrasonic sensors 11 that face the inner wall of the pipe 1, and there are no pipe thickness measurement data in the other cases. The pipe shown in FIG. 5 is an example in which the thinnings 31 and 32 exist in the same circumferential direction of the pipe 1, but the pipe thickness measuring device 2 flows in the pipe 1 while rotating three-dimensionally. The eight ultrasonic sensors 11 in which pipe thickness measurement data exist vary depending on the pipe axis direction distance L. However, the thinned portion thickness measurement results 41a and 42a corresponding to the thinnings 31 and 32 are displayed by any of the eight ultrasonic sensors 11.

  The effect of the present embodiment configured as described above will be described.

  As a prior art, for example, the device structure is divided into a plurality of units such as a sensor unit, a pulsar receiver unit, a power supply unit, etc., and these are arranged and connected along the pipe axis direction. There was a device. However, in such a long structure of the entire apparatus, there is a possibility that the discontinuous part (branch or the like) of the piping structure cannot be smoothly passed. As another prior art, there has been a measuring device in which electromagnetic ultrasonic probes are arranged three-dimensionally in a spherical measuring device body and moved in a pipe. However, since the electromagnetic ultrasonic probe needs to be close to the object (in this case, the pipe inner wall) that transmits and receives ultrasonic waves, the spherical outer diameter needs to be substantially the same as the pipe inner diameter. Therefore, there is a problem that it is not possible to cope with a change in the diameter of the pipe, and there is a concern that the pipe cannot pass when there is a deposit on the inner wall of the pipe.

  On the other hand, in the present embodiment, in the pipe thickness measuring apparatus 2 using ultrasonic waves, a plurality of ultrasonic sensors 11 that transmit and receive the ultrasonic waves 6 to and from the liquid 8 in the pipes 1 and ultrasonic waves. The pipe thickness is determined by using the means 12 for transmitting / receiving, the means 14 for measuring / recording a plurality of reflected wave propagation times for each ultrasonic sensor 11, and the propagation time of the ultrasonic wave substantially perpendicularly incident on the pipe inner wall. Since the calculating means 15 is provided, it is possible to measure the thickness of the pipe having the structural discontinuity portion.

  A second embodiment of the present invention will be described with reference to FIGS.

  FIG. 7 is a flowchart showing a pipe thickness measuring method using ultrasonic waves according to the second embodiment of the present invention. Since the operations other than step S104 are the same as those in the first embodiment, description thereof will be omitted.

  In step S105, ultrasonic waves are transmitted to all ultrasonic sensors 11 at every time interval (step S102), received waves are recorded (step S103), and pipe thicknesses are calculated (step S104). The posture of the pipe thickness measuring device 2 is recorded.

  FIG. 8 is a diagram schematically showing the result of pipe thickness measurement according to this example for the pipe shown in FIG. Since the posture data of the pipe thickness measuring device 2 for each hour is recorded, the ultrasonic wave is incident substantially perpendicular to the inner surface of the pipe 1 among the 26 ultrasonic sensors 11 of the pipe thickness measuring device 2. It is possible to identify a sensor that can measure ultrasonic waves to be measured, and to grasp the relative position of the ultrasonic sensor 11 with respect to the circumferential position of the pipe 1. From this, at the positions corresponding to the thinnings 31 and 32, the thickness of the thinning part is measured as 41b and 42b. That is, it is possible to display the pipe circumferential direction position of the thinning.

  The effect of the present embodiment configured as described above will be described.

  In the present embodiment, since a means for measuring the posture of the pipe thickness measuring device is additionally provided with respect to the first embodiment, it is possible to specify the position in the pipe circumferential direction of the thinning.

DESCRIPTION OF SYMBOLS 1 Pipe 2 Pipe thickness measurement apparatus 6 Ultrasonic 7 Movement path 8 Liquid 11 Ultrasonic sensor 12 Ultrasonic transmission / reception means 13 Attitude measurement means 14 Ultrasonic propagation time measurement and recording means 15 Pipe thickness calculation means 21, 22 Received signals 31, 32 Thinning thickness 41a, 42a, 41b, 42b Thinning portion thickness

Claims (6)

A plurality of ultrasonic sensors that transmit and receive ultrasonic waves to and from the liquid in the pipe;
Means for transmitting and receiving ultrasound;
Means for measuring and recording a plurality of reflected wave propagation times for each ultrasonic sensor;
Means for calculating the pipe thickness using the propagation time of the ultrasonic wave perpendicularly incident on the pipe inner wall;
A pipe thickness measuring device using ultrasonic waves, characterized by comprising: In claim 1,
The pipe thickness measuring apparatus using ultrasonic waves further includes means for measuring the posture of the pipe thickness measuring apparatus. In claim 2,
The pipe thickness measuring apparatus using ultrasonic waves, wherein the means for measuring the posture of the pipe thickness measuring apparatus is an acceleration sensor. A pipe thickness measuring device including a plurality of ultrasonic sensors and means for transmitting and receiving ultrasonic waves is arranged so as to be movable in the pipe,
The reflected wave propagation time is measured by the respective ultrasonic sensors on the pipe thickness measuring device from the inside of the pipe,
A pipe thickness measurement method using ultrasonic waves, characterized in that the pipe thickness is calculated using propagation time of ultrasonic waves incident perpendicularly to the pipe inner wall. In claim 4,
Further, the pipe thickness measuring method using ultrasonic waves, characterized in that the posture of the pipe thickness measuring device is measured. In claim 5,
Propagation time of ultrasonic waves perpendicular to the pipe inner wall by selectively transmitting / receiving ultrasonic sensors in the direction perpendicular to the pipe inner wall from the posture measurement result of the pipe thickness measuring device A method for measuring the thickness of a pipe using ultrasonic waves, characterized in that the method is used.

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