JP2003254942A - Pipe inspection device and pipe inspection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect easily and accurately the laying state, such as exfoliation of lining, from the outer face of a pipe during plant operation regardless of the pipe state, by a pipe inspection device for inspecting abnormality of the lining applied to the inner face of the pipe in a plant facility or the like. <P>SOLUTION: The installation position of a reception sensor 7 relative to a transmission sensor 6 installed on the surface of the pipe 2 is determined by an ultrasonic wave range on the pipe surface from the transmission sensor 6 calculated based on the thicknesses of the pipe 2 and a lining 1, an incident angle θ<SB>p</SB>of an ultrasonic wave 5 to the pipe 2, and an angle of refraction θ<SB>l</SB>of the ultrasonic wave 5 from the pipe 2 to the lining 1 corresponding to the difference of ultrasonic wave velocities v<SB>p</SB>, v<SB>l</SB>caused by the difference in acoustic impedances Z<SB>1</SB>, Z<SB>2</SB>of the pipe 2 and the lining 1, and the installation position of the reception sensor 7 is finely adjusted and optimized onto the position where a signal level of a lining bottom face echo 5b becomes maximum in consideration of an error of the thickness, to thereby detect surely the lining bottom face echo 5b. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention effectively detects an echo from a bottom surface of a lining, which is an abnormality of a lining constructed on an inner surface of piping such as plant equipment.
The present invention relates to a pipe inspection device and a pipe inspection method for inspecting a lining installation state from the outer surface of a pipe.

[0002]

2. Description of the Related Art For example, the inspection of the state of the lining of seawater system piping in a nuclear power plant is performed by performing visual inspection, tapping sound inspection, by opening the piping at the time of regular inspections performed about once a year.
Inspections such as pinhole testers are being conducted.

As a method of estimating the lining installation state in a pipe from the outer surface of the pipe, there is an open patent "Piping inspection method and device" (Publication No. P2000329751). This is to estimate the installation state of the lining in the pipe by detecting the multiple echo from the bottom of the pipe and calculating the attenuation constant of the peak value of the multiple echo.

Although the object is different, as a method for inspecting the inner surface of a pipe having a double structure, for example, as a method for measuring the thickness of a scale attached to the inner surface of a carbon steel pipe, the published patent " There is a “Pipe inner scale thickness measurement system” (PH11-367815), and this method uses the fact that the waveform pattern changes depending on the presence or absence of scale. In addition to the above method, a method of directly detecting the echo from the scale and converting the thickness thereof is also applied.

Further, as a method of measuring the lining thickness of a pipe in which a carbon steel pipe is lined with a natural hard rubber or the like, an open patent "Method for measuring thickness of double-layer metal body" (PH11-122429) There is. This method detects the echoes of the pipe and lining by vertical flaw detection with a single piezoelectric element for an object that has a certain relationship between the pipe and lining thickness, and determines the thickness of the pipe and lining from the propagation time. It is something to measure.

There is also an oblique angle flaw detection method using a two-probe, which is generally used for detecting defects on the back surface of an iron plate or the like.

[0007]

As described above, the state inspection of the lining in the seawater system piping of the nuclear power plant is
Normally, the piping is opened only during a regular inspection once a year. In order to open the pipe, it is necessary to isolate the system, drain the seawater accumulated in the pipe, and remove the heat insulating material. Further, in order to visually inspect the state of the lining, it is necessary to remove the shellfish attached to the inner surface of the pipe.

Since these operations are basically performed manually, there are problems in terms of both time and cost. Further, since it is necessary to isolate the system, the position and number of pipes that can be inspected during one regular inspection are limited.
Moreover, in order to increase the operation of the power plant, it is necessary to keep the periodic inspections as short as possible, and since the number of pipes that can be inspected in one regular inspection is reduced, all pipes can be inspected by the prescribed number of regular inspections. It is becoming stricter to check the soundness of the process.

On the other hand, the published patent "Piping Inspection Method and Apparatus", in which the state of the inner surface of the pipe is estimated from the outer surface of the pipe
(Publication No .: P2000329751) is a method that can inspect the lining installation status during operation, which makes it easier to carry out periodic inspections compared to the above-mentioned artificial inspection method.
However, in the piping of the actual plant, it is assumed that stable echo cannot be obtained due to the rust generated on the surface, the non-uniformity of the coating state, and the effect of noise. In this case, an accurate piping inspection is required. I can't do it.

The piping used in the seawater system of a nuclear power plant is a carbon steel piping provided with a polyethylene or natural rubber lining. For this reason, unlike the adhesion of scale, the acoustic impedance between the pipe and the lining is different, and the level of the echo from the bottom of the lining is markedly reduced, and the above-mentioned "Pipe inner scale thickness measurement system" (PH11-367815) Like,
Detecting changes in the waveform due to changes in lining thickness is a difficult problem.

[Method for measuring thickness of double-layered metal body]
Regarding (PH11-122429), although the measurement target is the same as the seawater piping of the nuclear power plant, the thickness of the piping and lining may not meet the measurement conditions.In this case, the echo on the bottom of the piping and the lining Sometimes the bottom echo cannot be separated and the lining condition cannot be accurately inspected.

[0012] Further, the bevel flaw detection method generally applied conventionally is a method of detecting a defect on the back surface of a pipe by the presence or absence of an echo easily obtained from the back surface of the pipe, and detects a state between the pipe and the lining. Not a thing.

The present invention has been made in view of the above problems, and can easily and accurately detect a laying state such as peeling of the lining from the outer surface of the pipe during plant operation, regardless of the state of the pipe. An object of the present invention is to provide a pipe inspection device and a pipe inspection method that can be performed.

[0014]

That is, a pipe inspection device according to the present invention is a pipe inspection device for inspecting a state of a lining which is in close contact with an inner surface of the pipe, the pipe inspection device being installed on the surface of the pipe. Ultrasonic transmitting means for transmitting and injecting ultrasonic waves from the surface toward the inside, and is installed on the surface of the pipe, with the transmission of ultrasonic waves from the surface of the pipe by the ultrasonic transmitting means, Ultrasonic receiving means for receiving the pipe reflected wave reflected by the bottom surface and the lining reflected wave reflected by the bottom surface of the lining,
A reflected wave signal processing means for processing the signal of the pipe reflected wave and the signal of the lining reflected wave received by the ultrasonic wave receiving means, wherein the ultrasonic wave receiving means is provided for the ultrasonic wave to the pipe from the ultrasonic wave transmitting means. Incident angle, thickness of pipe and lining, of the lining reflected wave calculated based on each of the refraction angle of ultrasonic waves from the pipe to the lining according to the difference in ultrasonic sound velocity due to the difference in acoustic impedance between the pipe and lining The installation position of the ultrasonic receiving means is finely adjusted to a position where the signal level of the lining reflected wave processed by the reflected wave signal processing means is maximized while being installed at the position where the pipe surface reaches. .

In such a pipe inspection apparatus according to the present invention, the installation position of the ultrasonic wave receiving means on the surface of the pipe is determined by the angle of incidence of ultrasonic waves from the ultrasonic wave transmitting means to the pipe, the thickness of the pipe and the lining, It is installed according to the pipe surface arrival position of the lining reflected wave calculated based on each of the refraction angle of the ultrasonic wave from the pipe to the lining according to the difference in ultrasonic velocity of sound due to the difference in acoustic impedance between the pipe and the lining. At the same time, since the installation position of the ultrasonic wave receiving means is finely adjusted to a position where the signal level of the lining reflected wave processed by the reflected wave signal processing means is maximum, when the adhesion of the lining on the inner surface of the pipe is normal. , The lining reflected wave can be reliably detected.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the arrangement of a pipe inspection apparatus according to the embodiment of the present invention.

In FIG. 1, a polyethylene lining 1 is installed in close contact with the inner surface of a pipe 2 to be inspected.

This pipe inspection apparatus is composed of a transmission sensor 6 which is a piezoelectric element for transmitting the ultrasonic wave 5 from the surface of the pipe 2 to the inside and a piezoelectric element for receiving the ultrasonic wave 5 which is a reflected wave from the inside of the pipe 2. It has a certain receiving sensor 7, and the transmitting sensor 6 and the receiving sensor 7 are pulsar / receiver 8
Driven by.

The transmitting sensor 6 is oriented by a shoe 3 so that the ultrasonic wave 5 is incident and propagated at an oblique angle of 45 degrees with respect to the surface of the pipe 2, and the shoe 3 is designed so that impedance matching with the pipe 2 is improved. It is attached to the surface of the pipe 2 via 4.

The receiving sensor 7 is also oriented by the shoe 3 so as to receive the ultrasonic wave 5 propagating at an angle of 45 degrees as a reflected wave from the bottom surface of the pipe 2 with respect to the surface of the pipe 2. The shoe 3 on the receiving side is also attached to the surface of the pipe 2 via the couplant 4 so that the impedance matching with the pipe 2 is improved.

The ultrasonic wave 5 which is propagated by the transmission sensor 6 from the surface of the pipe 2 at an oblique angle of 45 degrees becomes the reflection echoes 5a and 5a 'by the bottom surface of the pipe 2 and the reflection echo 5b by the bottom surface of the lining 1 and the oblique angle. At 45 degrees, it propagates toward the surface of the relevant 2 and is received by the reception sensor 7.

The respective signals of the reflection echoes 5a, 5a 'by the bottom surface of the pipe 2 and the reflection echo 5b by the bottom surface of the lining 1 received by the reception sensor 7 are
After being converted into a digital signal via the AD converter 9, the presence or absence of peeling of the lining 1 is detected by inputting to the personal computer 10 and signal processing.

That is, this piping inspection apparatus is an inspection apparatus by the oblique angle 2 probe method using two piezoelectric elements, that is, the ultrasonic wave transmission sensor 6 and the ultrasonic wave reception sensor 7.
Depending on the reception time difference between the echoes 5a and 5b due to the different propagation paths of the reflection echo 5a due to the bottom surface of the lining 1 and the reflection echo 5b due to the bottom surface of the lining 1, the lining bottom surface reflection echo 5b is received after receiving the piping bottom surface reflection echo 5a. Whether or not the lining 1 is peeled off is detected depending on whether or not the lining 1 is reliably received.

In this embodiment, the thickness of the pipe 2 is 9.5 m.
The thickness of m and lining 1 is 3 mm.

FIG. 2 is a diagram showing a propagation path of the ultrasonic wave 5 in the pipe 2 and the lining 1 by the pipe inspection device. Here, for simplification of description, the pipe 2 is a flat plate.

Since the ultrasonic wave 5 is incident on the pipe 2 at an angle of 45 degrees, the propagation distance Lp in the pipe 2 is calculated as Lp = 9.5 / cos45 °, which is 13.44 mm.

Ultrasonic waves propagating in the pipe 2 and the lining 1.
Since the sound velocity of 5 is different, refraction occurs at the boundary,
The angle follows Snell's law, v_p/ V_l= Sin θ_p/ Sin θ_l (V_p: Ultrasonic velocity in pipe 2, v_l: Inside lining 1
Ultrasonic speed of sound, θ_p, Θ _l: Ultrasonic wave 5 incident angle 11 and
And refraction angle 12), and v_p: 5950m / s, v
_l: 2000m / s, θ_p: At 45 degrees, enter lining 1
Refraction angle θ_lIs 13.75 degrees.

Therefore, similarly to the case where the propagation distance Lp in the pipe 2 is obtained, the propagation distance Ll in the lining 1 is 3.09 mm, which is obtained by Ll = 3.0 / cos 13.75 °.

Therefore, each propagation time t in the propagation path 1 (13) of the pipe bottom reflection echo 5a and the propagation path 2 (14) of the lining bottom reflection echo 5b shown in FIG.
1 and t2 are route 1: t1 = 13.44 (mm) / 5950 (m / s) × 2 = 4.52
(Μs) Path 2: t2 = (13.44 (mm) / 5950 (m / s) +3.09 (mm) /
It becomes 2000 (m / s) × 2 = 7.61 (μs).

FIG. 3 is a diagram showing an ideal inspection echo waveform by the pipe inspection device.

From these facts, theoretically, the echo 5b from the bottom of the lining will be obtained 3.09 μs (= t2-t1) after the echo 5a from the bottom of the pipe is obtained.
Ideally, if the echo waveform as shown in FIG. 3 is obtained, the state of the lining 1 can be inspected without any modification.

Since the carbon steel pipe 2 and the lining 1 have different acoustic impedances Z, the ratio of the ultrasonic waves 5 transmitted from the carbon steel pipe 2 to the lining 1 is only about 16% as shown below.

R = 1-((Z ₁ -Z ₂ ) / (Z ₁ +
Z ₂ )) ² = 0.16 (R: transmittance, Z ₁ : acoustic impedance of pipe 2 (4.
6 × 10 ⁷ ), Z ₂ : Acoustic impedance of lining 1 (2.0 × 10 ⁶ )) Actual ultrasonic transmission / reception sensors 6 and 7 have frequency characteristics,
Since it has damping characteristics and its transmittance is very small, it is not possible to obtain an ideal echo waveform as shown in FIG. Therefore, how to obtain the echo 5b from the lining 1 by emphasizing it becomes an issue of the inspection device.

Therefore, in this embodiment, 1) the distance between the sensors is optimized, and 2) the output of the pulsar / receiver is optimized, so that the lining bottom surface reflection echo 5b is obtained.
Was emphasized.

First, 1) As an adjusting method for optimizing the distance between the sensors, the sensors 6, 7 during the lining propagation are used.
Each sensor 6,7 for obtaining the echo 5a from the bottom of the pipe for 1.47 mm (0.73 × 2.014) that propagates in the direction in which
It will be installed at 20.47 mm in addition to the center distance of 19 mm (9.5 × 2). Then, by adjusting the distance between the sensors 6 and 7 centering on this center-to-center distance of 20.47 mm and setting the point at which the lining bottom surface reflected echo 5b propagates to the maximum as the optimum point, the reception sensor 7 echoes the lining 1. 5b can be sampled and received with high sensitivity.

FIG. 4 is a diagram showing respective inspection echo waveforms when the distance between the transmission / reception sensors 6 and 7 of the pipe inspection apparatus is arranged at an optimum position and when the distance is changed and arranged before and after the optimum position.

As shown in FIG. 4A, when the distance between the transmission / reception sensors 6 and 7 is set at the optimum position corresponding to the propagation path of the lining bottom surface reflection echo 5b,
The lining bottom echo 5b is obtained from the pipe bottom echo 5a with a delay of about 3 μs as the theoretical value. Moreover, this FIG.
As is clear from (A), the pipe bottom echo 5a has a high signal level, and due to the damping characteristics of the sensors 6 and 7, a high level echo remains even in the vicinity of the lining bottom echo 5b, which separates the lining bottom echo 5b. This is one of the causes for making it difficult. Here, since the lining bottom echo 5b starts at a position about 1.5 μs away from the end of the echo due to damping, it is possible to separate the pipe bottom echo 5a and the lining bottom echo 5b. It turns out to be easy.

The installation position of the reception sensor 7 with respect to the transmission sensor 6 installed on the surface of the pipe 2 is in accordance with the optimization of the inter-sensor distance described above.
Thickness, the incident angle θ _{p of} the ultrasonic wave 5 with respect to the pipe 2, the difference in the acoustic sonic speeds v _p and v _{l due to} the difference in the acoustic impedances Z ₁ and Z ₂ between the pipe 2 and the lining 1, and the lining from the pipe 2 It is determined by the ultrasonic wave arrival distance on the pipe surface from the transmission sensor 6 calculated based on the refraction angle θ _{l of} the ultrasonic wave 5 to 1. However, further considering the thickness error, the lining bottom echo 5b The installation position of the reception sensor 7 is finely adjusted to a position where the signal level becomes maximum.

On the other hand, as shown in FIG. 4B, when the transmitter / receiver sensors 6 and 7 are installed at positions closer to each other than the optimum position, the pipe bottom echo 5a and the lining bottom echo 5b are separated. Although possible, the signal level of the lining bottom echo 5b is less than half that in the case of the optimum distance, and it is possible that the lining bottom echo 5b cannot be determined due to the influence of noise.

Further, as shown in FIG. 4 (C), when the distance between the transmission / reception sensors 6 and 7 is set to a position farther than the optimum position, the optimum distance shown in FIG. 4 (A) is obtained. As compared with the case, it can be seen that there is a large wave behind the lining bottom echo 5b. This is a pipe bottom echo 5a 'which is reflected twice on the bottom of the pipe 2, and the lining bottom echo 5b is a pipe bottom echo 5a and 2 which are reflected once.
It will be sandwiched between the circular reflection bottom surface echo 5a '. In this case, if the thickness of the lining 1 or the pipe 2 changes, the lining bottom echo 5b and any one of the pipe bottom echoes 5a and 5a 'may overlap. It may not be possible to judge.

As described above, by optimizing and adjusting the distance between the transmission / reception sensors 6 and 7, it becomes possible to receive the lining bottom surface echo 5b simply and accurately.

2) As an adjusting method for optimizing the output of the pulsar / receiver, echo 5 from the bottom of the pipe is used.
By ignoring a, even if the pipe bottom echo 5a is saturated, the energy of ultrasonic transmission by the pulser / receiver 8 and the damping rate are adjusted so that the signal level of the lining bottom echo 5b is set to the maximum. ,
The ratio between the lining bottom echo 5b and the stationary noise is set to be as large as possible.

By combining the two methods according to 1) and 2) above, the echo 5b from the bottom surface of the lining can be obtained with good S / N.

Next, the operation of automatically determining the normality / abnormality of the lining 1 from the echo signal obtained by the pipe inspection by the pipe inspection device having the above-mentioned configuration will be described.

Here, the case where the pipe thickness is 9.5 mm and the lining thickness is 3 mm, which is shown in this embodiment as in the above, will be described.

First, the propagation time of the ultrasonic wave 5 propagating in the shoes 3 and 3 on the transmitting side and the receiving side is measured in advance (here, about 8 μs).

The propagation time until the echo 5a reflected by the bottom surface of the pipe 2 (path 1 in FIG. 2) reaches the reception sensor 7 and is received by the ultrasonic wave 5 output from the transmission sensor 6 is the above-mentioned pipe. Pipe bottom echo 5 only inside 2
Approximately 12.5 μs, which is the propagation time t1 (= 4.52 μs) of a plus the propagation time of 8 μs inside the shoes 3 and 3, which is over 12.5 μs as seen from the control system (personal computer 10) of the pulsar / receiver 8. The pipe bottom echo 5a is obtained about 12.5 μs after the start of transmission of the sound wave 5.

Although the thickness of the pipe 2 is almost uniform, the pipe bottom echo 5a is taken into consideration in consideration of the case where the wall thickness is reduced.
The detection start time is 10 μs or less, which is slightly shorter than the theoretical propagation time of the pipe bottom echo 5a of about 12.5 μs, and is the time at which a predetermined signal level threshold value is reached. To do.

Since the propagation time t2 of the lining bottom echo 5b lags behind the propagation time t1 of the pipe bottom echo 5a by about 3.09 μs as described above, even when the lining 1 is thinned to 2 mm As possible,
2 μs after the detection of the bottom surface echo 5a of the pipe is set as the start point of the detection of the bottom surface echo 5b of the lining. Then, 2 μs after the start of detection of the lining bottom echo 5b
The gate processing is performed so as to detect only during the period, and the lining bottom surface echo 5b is detected based on the threshold value of the signal level determined in advance in consideration of stationary noise.

As described above, by performing the gate processing on the detection time of the lining bottom echo 5b, it is possible to reliably detect the lining bottom echo 5b separately from the other pipe bottom echoes 5a and 5a '. , Normal / abnormal of the lining 1 can be accurately detected.

Further, within the gate processing time for detecting the lining bottom echo 5b, instead of detecting the lining bottom echo 5b based on a predetermined signal level threshold value, the gate processing time is changed. Squared signal level value and integrated, the detection value is determined based on a predetermined threshold value considering the integrated value of stationary noise, or the absolute value of the signal level value within the gate processing time. By adopting a configuration in which the value obtained by integrating is detected and determined based on a predetermined threshold value in consideration of the integrated value of stationary noise, the lining bottom surface echo 5b can be detected more remarkably, and a more accurate lining is achieved. It is possible to make a normality / abnormality determination of 1.

Therefore, according to the pipe inspection apparatus having the above-mentioned configuration, the installation position of the reception sensor 7 with respect to the transmission sensor 6 installed on the surface of the pipe 2, the thickness of the pipe 2 and the lining 1, the ultrasonic wave 5 with respect to the pipe 2. Incident angle θ _p ,
Acoustic impedance Z ₁ , Z between the pipe 2 and the lining 1
Ultrasonic sound velocity _v p due to the difference of _{2, v} according to the difference between _l pipe 2
From the transmission sensor 6 calculated based on the refraction angle θ _{l of} the ultrasonic wave 5 from the lining 1 to the lining 1, and in consideration of the thickness error, the bottom surface echo of the lining is considered. Since the installation position of the reception sensor 7 is finely adjusted and optimized to the position where the signal level of 5b is maximized, when the lining 1 laid on the inner surface of the pipe 2 is in normal contact, the lining The bottom echo 5b can be reliably detected, and the pipe 2
The peeling of the lining 1 on the inner surface of the pipe 2 can be reliably detected from the outside of the pipe 2.

Further, according to the pipe inspection apparatus having the above structure,
Since the energy of the ultrasonic wave transmission by the pulser / receiver 8 and the damping rate are adjusted so that the signal level of the lining bottom echo 5b is maximized, the presence or absence of the lining bottom echo 5b can be reliably detected. Yes, the lining 1 on the inside of the pipe 2
It becomes possible to accurately detect the abnormalities.

Further, according to the pipe inspection device having the above structure,
Based on the difference between the propagation time t1 of the pipe bottom echo 5a and the propagation time t2 of the lining bottom echo 5b (about 3.09 μs), the detection start timing of the lining bottom echo 5b after the pipe bottom echo 5a is detected is set. At the same time, the gate processing is performed so that the detection target is a fixed time (2 μs) after the detection start timing, and the lining bottom echo 5b is detected by comparison with the threshold value of the signal level considering stationary noise. The lining bottom surface echo 5b can be reliably detected by separating from the other piping bottom surface echoes 5a and 5a ', and the normality / abnormality of the lining 1 can be accurately detected.

Further, according to the pipe inspection apparatus having the above-mentioned configuration, the pipe bottom echo 5a is detected based on the difference (about 3.09 μs) between the propagation time t1 of the pipe bottom echo 5a and the propagation time t2 of the lining bottom echo 5b. In addition to setting the detection start timing of the lining bottom surface echo 5b from the beginning, the gate processing is performed for a fixed time (2 μs) after the detection start timing, and the echo signal level value within the gate processing time is set. Since the lining bottom surface echo 5b is detected by comparing the integrated value of the squared value or the absolute value with the threshold value of the signal level considering the integration value of stationary noise, the lining bottom surface echo 5b is detected more significantly. Therefore, the normality / abnormality of the lining 1 can be accurately detected.

The invention of the present application is not limited to the above-described embodiments, but can be variously modified at the stage of implementation without departing from the scope of the invention. Furthermore, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, some constituents may be deleted from all constituents shown in each embodiment, or even if some constituents are combined, the problems described in the section of the problem to be solved by the invention can be solved, When the effects described in the section of the effects of the invention can be obtained, a structure in which these constituent elements are deleted or combined can be extracted as the invention.

[0058]

As described above, according to the pipe inspection apparatus of the present invention, it is possible to easily and accurately detect the laying state such as the peeling of the lining from the outer surface of the pipe during the plant operation regardless of the state of the pipe. It will be possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a pipe inspection device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a propagation path of an ultrasonic wave 5 in a pipe 2 and a lining 1 by the pipe inspection device.

FIG. 3 is a view showing an ideal inspection echo waveform by the pipe inspection device.

FIG. 4 is a diagram showing respective inspection echo waveforms when the distance between the transmission / reception sensors 6 and 7 of the pipe inspection device is arranged at an optimum position and when the arrangement is changed to the front and rear positions thereof.

[Explanation of symbols]

1 ... Lining 2 ... Piping 3 ... Shoe 4 ... Couplant 5 ... Ultrasonic wave 5a ... Piping bottom surface (one reflection) echo 5a '... Piping bottom surface (twice reflection) echo 5b ... Lining bottom surface (reflection) echo 6 ... Transmission sensor 7 ... Reception sensor 8 ... Pulsar / Receiver 9 ... A / D converter 10 ... PC 11 ... Ultrasonic wave incident angle (θ _p ) 12 ... Piping / lining boundary refraction angle (θ _l ) 13 ... Pipe bottom echo propagation path (1) 14 ... Lining bottom surface echo propagation path (2)

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kiyoshi Iwata             8th Shinsugita Town, Isogo Ward, Yokohama City, Kanagawa Prefecture             Ceremony company Toshiba Yokohama office F-term (reference) 2G047 AA07 AB01 AB05 AC01 BA02                       BB02 BB04 BC09 CA01 EA10                       EA12 GA03 GA15 GB27 GF06                       GF10 GG01 GG06 GG14 GG28                       GG30 GG33                 2G075 CA13 CA36 DA16 FA16 FC15                       GA09

Claims (10)

[Claims] 1. A pipe inspection device for inspecting a state of a lining which is in close contact with an inner surface of a pipe, which is installed on a surface of the pipe and transmits an ultrasonic wave toward the inside from the surface of the pipe to make the ultrasonic wave incident. Ultrasonic wave transmitting means, installed on the surface of the pipe, the ultrasonic wave transmitting means transmits ultrasonic waves from the surface of the pipe, and the pipe reflected wave reflected by the bottom surface of the pipe and the bottom surface of the lining. The ultrasonic wave receiving means for receiving the lined reflected wave and the reflected wave signal processing means for processing the signal of the pipe reflected wave and the signal of the lined reflected wave received by the ultrasonic wave receiving means. The means depends on the incident angle of ultrasonic waves from the ultrasonic wave transmitting means to the pipe, the thickness of the pipe and the lining, and the difference in acoustic impedance between the pipe and the lining. Installed at the pipe surface arrival position of the lining reflected wave calculated based on each of the refraction angles of the ultrasonic waves from the pipe to the lining according to the difference in sound velocity of sound, the lining reflection processed by the reflected wave signal processing means A pipe inspection apparatus, wherein the installation position of the ultrasonic receiving means is finely adjusted to a position where the signal level of the wave is maximized. 2. A pipe inspection device for inspecting a state of a lining which is in close contact with an inner surface of a pipe, which is installed on the surface of the pipe and transmits ultrasonic waves from the surface of the pipe toward the inside to make the ultrasonic wave incident. Ultrasonic wave transmitting means, installed on the surface of the pipe, the ultrasonic wave transmitting means transmits ultrasonic waves from the surface of the pipe, and the pipe reflected wave reflected by the bottom surface of the pipe and the bottom surface of the lining. An ultrasonic wave receiving means for receiving the lined reflected wave, a reflected wave signal processing means for processing the signal of the pipe reflected wave and the signal of the lined reflected wave received by the ultrasonic wave receiving means, and the ultrasonic wave transmitting means. The energy of ultrasonic transmission and the damping rate are adjusted to set the signal level of the lining reflected wave processed by the reflected wave signal processing means to the maximum. Pipe inspection device, wherein the transmission adjustment means, by comprising the that. 3. The pipe inspection apparatus according to claim 1, further comprising: a lining reflection that is processed by the reflected wave signal processing means by adjusting energy and damping rate of ultrasonic wave transmission by the ultrasonic wave transmitting means. A pipe inspection apparatus comprising a transmission adjusting means for setting a wave signal level to a maximum. 4. The reflected wave signal processing means does not include stationary noise at a constant gate time after signal detection of the pipe reflected wave based on a difference in propagation time between the pipe reflected wave and the lining reflected wave. The pipe inspection apparatus according to any one of claims 1 to 3, wherein the signal of the lining reflected wave is detected by comparison with a predetermined threshold value. 5. The reflected wave signal processing means sets a detection signal level value at a fixed gate time after signal detection of the pipe reflected wave based on a difference in propagation time between the pipe reflected wave and the lining reflected wave. The signal of the lining reflected wave is detected by comparing an integral value of a squared value or an absolute value with a predetermined threshold value that does not include an integral value of stationary noise. Or the pipe inspection device according to item 1. 6. A pipe inspection method for inspecting a state of a lining which is in close contact with an inner surface of a pipe, wherein ultrasonic waves are transmitted from the surface of the pipe toward the inside and are incident on the surface of the pipe. Transmitting step, on the surface of the pipe, with the transmission of ultrasonic waves from the surface of the pipe by the ultrasonic wave transmitting step, the pipe reflected wave reflected by the bottom surface of the pipe and the lining reflection reflected by the bottom surface of the lining An ultrasonic wave receiving step for receiving a wave, and a reflected wave signal processing step for processing the signal of the pipe reflected wave and the signal of the lining reflected wave received by this ultrasonic wave receiving step, and the reflected wave by the ultrasonic wave receiving step The reception position of the ultrasonic wave, the incident angle of the ultrasonic wave to the pipe in the ultrasonic wave transmitting step, the thickness of the pipe and the lining, And set to the pipe surface arrival position of the lining reflected wave calculated based on each of the refraction angle of the ultrasonic waves from the pipe to the lining according to the difference in the ultrasonic speed of sound due to the difference in the acoustic impedance of the lining and the reflection, A pipe inspection method characterized in that the receiving position of the reflected wave is finely adjusted to a position where the signal level of the reflected wave of the lining processed by the wave signal processing step is maximized. 7. A pipe inspection method for inspecting a state of a lining which is in close contact with an inner surface of a pipe, wherein ultrasonic waves are transmitted from a surface of the pipe to an inside thereof to be incident. Transmitting step, on the surface of the pipe, with the transmission of ultrasonic waves from the surface of the pipe by the ultrasonic wave transmitting step, the pipe reflected wave reflected by the bottom surface of the pipe and the lining reflection reflected by the bottom surface of the lining An ultrasonic wave receiving step of receiving a wave, a reflected wave signal processing step of processing a pipe reflected wave signal and a lining reflected wave signal received by this ultrasonic wave receiving step, and an ultrasonic wave transmitting step of the ultrasonic wave transmitting step. The lining reflected wave processed by the reflected wave signal processing step by adjusting energy and damping rate. Piping inspection wherein a transmission adjustment step of setting the signal level to the maximum, in that it consists of. 8. The pipe inspection method according to claim 6, further comprising: a lining reflection processed by the reflected wave signal processing step by adjusting energy and damping rate of ultrasonic wave transmission by the ultrasonic wave transmission step. A pipe inspection method comprising a transmission adjusting step for setting a wave signal level to a maximum. 9. The reflected wave signal processing step does not include stationary noise in a constant gate time after signal detection of the pipe reflected wave based on a difference in propagation time between the pipe reflected wave and the lining reflected wave. The pipe inspection method according to any one of claims 6 to 8, wherein the signal of the lining reflected wave is detected by comparison with a predetermined threshold value. 10. In the reflected wave signal processing step, a detection signal level value of a detected signal level value is set at a constant gate time after signal detection of the pipe reflected wave based on a difference in propagation time between the pipe reflected wave and the lining reflected wave. 9. A signal of a lining reflected wave is detected by comparing an integral value of a squared value or an absolute value with a predetermined threshold value that does not include an integral value of stationary noise. The piping inspection method according to item 1.