JP2003294718A - Device and method for piping inspection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems such that exfoliation and laying defects of polyethylene lining, which are applied inside the piping of an atomic power plant, and difficult to detect in its early stages because a visual inspection of lining exfoliation and condition thereof can be only conducted when piping spools are disassembled during regular inspections, and working hours of the plant regular inspections need much time for the piping inspection which are required to be reduced. <P>SOLUTION: By emitting ultrasonic pulses to a pipe wall from a bent portion of the pipe, a reflected echo from the interface between the pipe and the lining and a reflected echo from the surface of the lining can be detected. When exfoliation of the lining occurs, the reflected echo from the surface of the lining cannot be detected, and thereby the condition of lining can be examined from the outside of the piping during plant operation. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipe inspection device and a pipe inspection method for inspecting a lining installation state of a pipe having an inner surface lined like a seawater pipe used in a nuclear power plant.

[0002]

2. Description of the Related Art In a nuclear power plant, seawater is used for cooling plant equipment such as turbine equipment and nuclear reactor equipment. The inner surface of seawater piping (hereinafter simply referred to as piping) that guides seawater to plant equipment has a lining (lining) made of polyethylene resin or the like to increase corrosion resistance.
Has been applied. However, if the pipe is used for a long period of time, a damage phenomenon such as peeling of the lining may appear.

Piping is generally made of carbon steel, and if the lining is damaged, corrosion will be reduced, and seawater will leak, which may lead to an accident in the cooling system, or a serious accident in the entire nuclear power plant. is assumed. Therefore, promptly detecting damage to the piping such as peeling of the lining and repairing or replacing it as necessary not only ensures the integrity of the piping but also ensures the safety of the entire plant. It is also important. In particular, in the bent portion where the flange of the pipe is formed, the peeling of the lining tends to occur more frequently than in other portions, and it is an important issue to monitor the installed state of the lining in the bent portion.

[0004]

Conventionally, the lining of pipes is monitored by visual inspection. However, in a nuclear power plant, it is not possible to directly visually inspect the lining laying condition in the pipes because seawater for cooling flows in the pipes during plant operation. Further, it is not easy to stop the plant unnecessarily and inspect the inner surface of the pipe in consideration of the operation plan and efficiency of the plant. For this reason, conventionally, a part of the piping spool is removed within a limited period of periodic inspection in which the plant is stopped and plant equipment is inspected, and the lining installation state of the inner surface of the pipe is visually inspected. However, during operation of the plant, if the lining of the pipe is peeled off without notice, and the damage to the pipe itself develops, it will threaten the safety of the plant as described above, and depending on the degree of the damage. May need to be brought back to the factory for repair or replacement.

Therefore, it is important to detect the state of peeling of the lining and the like at an early stage even during the operation of the plant and take measures such as repairs in order to secure the safety and reliability of the nuclear power plant. That is. Also, in order to inspect the lining condition of the pipe lining during the periodic inspection of the plant, it is necessary to remove the pipe spool, and the disassembling and assembling work is troublesome, and the inspection time required for it is extra. However, there is a problem that the periodical inspection itself takes a long time. Therefore, there is a demand for a pipe inspection device and a pipe inspection method capable of monitoring the installation state of the pipe lining when it is always necessary even in the plant operating state.

The present invention solves the above problems and can monitor the lining laying state such as peeling from the outside of the pipe, can always confirm the soundness of the lining even during plant operation, and facilitate the work required for inspection. An object of the present invention is to provide a pipe inspection device and a pipe inspection method that shorten the inspection time.

[0007]

In order to achieve the above object, the invention of a pipe inspection apparatus according to claim 1 is a piezoelectric ultrasonic transducer provided outside a bent portion of a pipe whose inner surface is lined. An ultrasonic transmitter / receiver that transmits a pulse to the piezoelectric ultrasonic transducer and receives an ultrasonic reflection echo, and an ultrasonic pulse transmitted from the piezoelectric ultrasonic transducer toward a bent portion of a pipe. Characterized by a signal processing circuit that monitors the waveforms of the ultrasonic reflection echo reflected from the boundary between the pipe and the lining material and the ultrasonic reflection echo transmitted and propagated through the boundary between the pipe and the lining material and reflected from the lining surface. And

The invention of the pipe inspection device according to claim 2 is
In the pipe inspection apparatus according to claim 1, the ultrasonic wave transmitting surface of the piezoelectric ultrasonic transducer has a curvature according to the shape of the bent portion of the pipe.

The invention of the pipe inspection apparatus according to claim 3 is
The pipe inspection apparatus according to claim 1, wherein the piezoelectric ultrasonic transducer comprises two ultrasonic transducers for oblique angles, one of which is for transmitting and the other is for receiving, provided outside the bent portion of the pipe. Characterize.

The invention of the pipe inspection device according to claim 4 is
The pipe inspection apparatus according to claim 3, wherein the two ultrasonic transducers for oblique angles are provided separately along the axial direction of the pipe. In the pipe inspection apparatus according to the third aspect, the two ultrasonic transducers for oblique angles are provided separately along the circumferential direction of the pipe.

The invention of the pipe inspection apparatus according to claim 6 is
4. The pipe inspection apparatus according to claim 3, wherein two oblique-angle ultrasonic transducers having different incident angles are provided on one side of the bent portion of the pipe so as to be separated from each other along the axial direction of the pipe. And

According to the invention described in claims 1 to 6,
If the lining on the inside of the pipe is peeled off, or if it is not laid properly, the ultrasonic pulse is reflected from the lining surface.No lining echo is detected, or the lining is peeled off or laid poorly because the echo level decreases. Can be monitored from outside the pipe.

The invention of a pipe inspection method according to claim 7 is
Remove the pipe pool when the pipe is not in use, insert the pipe inner surface inspection jig from the pipe opening, and inspect the inner surface of the straight pipe portion of the pipe, and the outside of the bent portion of the pipe when the pipe is in use. It is characterized in that it comprises means for inspecting the presence or absence of the lining peeling or the installation condition by transmitting ultrasonic waves from the above to monitor the reflection echo.

According to the present invention, at the time of periodic inspection of the plant, the pipe spool is removed and the lining is visually inspected.
During operation of the plant, ultrasonically inspect the lining installation condition.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a pipe,
In the figure, only the bent portion 2 is shown. 3 is the inner surface 1 of the pipe 1.
It is a lining made of polyethylene resin applied to a. The pipe inspection apparatus according to the present invention for inspecting the laying state of the lining 3 includes a piezoelectric ultrasonic transducer 4 provided outside the bent portion 2 of the pipe 1 and a delay provided at the tip of the piezoelectric ultrasonic transducer 4. Material 5
An ultrasonic transmitter / receiver 6 connected to the piezoelectric ultrasonic transducer 4, a waveform display device 7 such as an oscilloscope connected to the ultrasonic transmitter / receiver 6, and a lining 3
And a signal processing device 8 for determining the presence / absence of lining separation.

In FIG. 1, the delay member 5 provided at the tip of the piezoelectric ultrasonic transducer 4 has an ultrasonic wave transmitting surface having a curvature depending on the shape of the outer surface 1b of the bent pipe portion 2, as shown in FIG. It is provided so that the ultrasonic pulse can be efficiently transmitted to the bent portion 2 of the pipe 1.

Next, the operation of the above pipe inspection apparatus will be described.
1 and 2, when a pulse is input to the ultrasonic transducer 4 from the ultrasonic transmitter / receiver 6, an ultrasonic pulse 9 is generated in the ultrasonic transducer 4, and the ultrasonic pulse 9 is passed through the delay member 5 to the pipe 1 Send to the bending section 2. The ultrasonic pulse 9 is applied to the delay material 5 and the outer surface 1b of the pipe 1.
It is divided into an ultrasonic wave reflection echo 11 which is reflected at a boundary 10 between and, and an ultrasonic wave pulse 12 which propagates through the plate thickness of the bent portion 2 of the pipe 1. Further, the ultrasonic pulse 12 is applied to the inner surface 1a of the pipe 1.
When it reaches the boundary 13 of the lining 3, it is divided into an ultrasonic reflection echo 14 reflected at the boundary 13 and an ultrasonic pulse 15 propagating in the lining 3. The ultrasonic reflection echo 14 reflected by the boundary 13 is received by the ultrasonic transducer 4. Further, the ultrasonic pulse 15 propagating through the lining 3 becomes a lining echo 17, which is an ultrasonic reflection echo reflected by the surface 16 of the lining 3, and again,
It passes through a boundary 13 between the inner surface of the pipe 1 and the lining 3 and is received by the ultrasonic transducer 4. These ultrasonic reflection echoes received by the ultrasonic transducer 4 are received by the ultrasonic transmitter / receiver 6 and further sent to the signal processing circuit 8. The waveform of the reflected echo received by the ultrasonic transceiver 6 is as shown in FIG.

In FIG. 3A, 18 is a waveform of the ultrasonic reflection echo 11 from the boundary 10 between the delay member 5 and the outer surface 1b of the pipe 1, and 19 is a boundary 13 between the inner surface 1a of the pipe 1 and the lining 3. Represents the waveform of the ultrasonic reflection echo 14 from
20 represents the waveform of the lining echo 17 reflected from the surface 16 of the lining 3. Piping 1 and lining 3
If the and are not peeled off and are installed well,
Since the ultrasonic pulse 15 propagates from the pipe 1 to the lining 3, the ultrasonic transducer 4 installed outside the pipe 1 detects the lining echo 17 reflected by the surface 16 of the lining 3 as a waveform 20. However, if the lining 3 is peeled from the pipe 1, the pipe 1
An air layer is formed at the boundary 13 between the inner surface 1a and the lining 3 and the ultrasonic pulse 12 is completely reflected, so that the ultrasonic pulse does not propagate from the pipe 1 to the lining 3, and as shown in FIG. The lining echo 17 from the surface 16 of No. 3 is not detected, and it is determined that the lining is separated.

Further, even when the pipe 1 and the lining 3 are not properly laid, even if the lining echo 17 reflected from the surface 16 of the lining 3 is detected, the echo level is higher than that when the lining echo 17 is laid well. Will be lowered and the lining installation will be judged to be defective.

In this way, the presence or absence of peeling of the lining,
Alternatively, the installed condition can be inspected by transmitting an ultrasonic wave from the outside of the pipe 1 and monitoring a reflection echo.
In the above-mentioned embodiment, the waveform display device 7 is not always necessary because it has only the function of monitoring the waveform.

Next, a second embodiment of the present invention will be described with reference to FIG. 4, those parts that are the same as those corresponding parts in FIG. 2 are designated by the same reference numerals, and a detailed description thereof will be omitted. In FIG. 4, two oblique-angle ultrasonic transducers 4a and 4b are used as means for transmitting and receiving ultrasonic waves, one for transmitting and the other for receiving. Two bevel angle ultrasonic transducers 4a, 4b are arranged outside the pipe bent portion 2 so as to be separated along the axial direction X of the pipe 1 so as to sandwich the center portion of the bent portion 2 of the pipe 1. .

The ultrasonic pulse 15 transmitted from the transmitting ultrasonic transducer 4a toward the bent portion 2 of the pipe 1.
Penetrates the bent portion 2 of the pipe 1 and the surface 1 of the lining 3
It is reflected by 6 and becomes a lining echo 17, which is received by the other receiving ultrasonic transducer 4b.

Also in the means shown in FIG. 4, the signal processing for detecting the lining peeling and the defective lining installation is the same as that in the means shown in FIG. That is, the lining 3 is the pipe 1
When it is peeled from the lining 3, the lining echo from the surface 16 of the lining 3 is not detected. On the other hand, when the lining 3 is laid well, the lining echo 17 from the surface 16 of the lining 3 is detected, and the presence or absence of the lining peeling or the laying state can be monitored.

Next, a third embodiment of the present invention will be described with reference to FIGS. 5 and 6, the same parts as those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 5 and FIG. 6, as the means for transmitting and receiving ultrasonic waves, two bevel angle ultrasonic transducers 4a,
4b is used, one for transmission and the other for reception. Two oblique-angle ultrasonic transducers 4a and 4b are arranged outside the bent pipe portion 2 along the circumferential direction Y of the pipe 1 so as to sandwich the center portion of the bent portion 2 of the pipe 1.

Ultrasonic pulse 15 transmitted from the transmitting ultrasonic transducer 4a toward the bent portion of the pipe 1 in two directions.
Penetrates the bent portion 2 of the pipe 1 and the surface 1 of the lining 3
It is reflected by 6 and becomes a lining echo 17, which is received by the other receiving ultrasonic transducer 4b.

Also in the means shown in FIGS. 5 and 6, the signal processing means for detecting the lining peeling and the lining installation defect is the same as the means shown in FIG. With such a configuration, since two ultrasonic transducers, one for transmitting and one for receiving, are used as means for transmitting and receiving ultrasonic waves, the configuration of the ultrasonic transducer is simplified and the size is increased as a whole. Be reduced.

Next, a fourth embodiment of the present invention will be described with reference to FIG. 7, the same parts as those in FIG. 2 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 7, two ultrasonic transducers 4a and 4b for oblique angles having different incident angles are used as means for transmitting and receiving ultrasonic waves, one for transmitting and the other for receiving. Two bevel angle ultrasonic transducers 4a, 4b are arranged on one side of the center of the bent portion 2 of the pipe 1 along the axial direction X of the pipe 1 and outside the bent portion 2 of the pipe 1. .

Ultrasonic pulse 15 transmitted from the transmitting ultrasonic transducer 4a toward the bent portion 2 of the pipe 1.
Penetrates the bent portion 2 of the pipe 1 and the surface 1 of the lining 3
It is reflected by 6 and becomes a lining echo 17, which is received by the other receiving ultrasonic transducer 4b.

Even in the means shown in FIG. 7, the signal processing means for detecting the peeling of the lining and the defect of the lining installation is the same as that shown in FIG.
It is the same as the means shown in. With such a configuration,
It becomes possible to dispose the transmitting ultrasonic transducer 4a and the receiving ultrasonic transducer 4b in the vicinity, and it is possible to reduce the mounting space of the ultrasonic transducer.

Next, a fifth embodiment of the present invention will be described with reference to FIG. When the pipe is not used, that is, at the time of periodic inspection of the plant, the spool 1A of the pipe 1 is appropriately removed, and the pipe inner surface inspection jig 21 equipped with the CCD camera is inserted into the pipe 1 through the opening of the pipe 1A. Visually inspect the lining condition on the inner surface of the straight pipe. Also,
The bent portion with the flange formed cannot be inspected by the pipe inner surface inspection jig 21 in the installed state because the gap is narrow, but pipes are used for the bent portion by using the pipe inspection device by the ultrasonic transducer of the present invention. The lining installation condition is inspected during the operation of the plant.

As described above, by combining the visual inspection method by the pipe inner surface inspection jig 21 performed at the time of periodic inspection of the plant and the pipe inspection method by the ultrasonic transducer of the present invention performed at the time of plant operation, during operation of the nuclear power plant The installed state of the lining of the bent part in the pipe can be checked in real time, and deterioration such as peeling of the lining can be detected at the initial stage. Further, during the periodic inspection of the plant, the lining inspection of the straight pipe portion of the pipe 1 can be efficiently performed by the pipe inner surface inspection jig 21 in a short time. Further, with this means, it is not necessary to provide an ultrasonic transducer on the straight pipe portion of the pipe 1, so that the cost is further reduced.

Next, FIG. 9 shows an example of the system of the pipe inspection apparatus according to the present invention, and FIG. 10 shows an example of the system sequence.
Shown in. First, as shown in FIG. 10, "pipe spool data 30" and "pipe three-dimensional data 3" to be inspected
"1" is stored in the database 32, and the bar code that recognizes the spool number is attached to the spool when performing the inspection, and it is called into the database before the inspection. In addition, "Conditions of pipe spool to be removed during regular inspection and general scheduled inspection period information 33"
In addition, the database 32 is called up with the “damaged area required for factory repair of lining piping and required construction period information 34”. Based on these pieces of information, the "lined piping inspection planning process 35" is performed. Based on this inspection plan, "Inspection plan development table 36 for lining pipes" and "Inner inspection procedure 37 for lining pipes at the time of inspection" are created, and the lining condition of the lining pipes is actually inspected during plant operation.
"Measurement data 38 from outside during driving" is collected. The data measured at the site is the signal processor 8 as shown in FIG.
Via the signal transmitter 22 to the signal receiver 2 in the office 23
4 is transmitted to the personal computer 25 and is stored in the database. Using the measurement data taken in, "Processing for reviewing inspection plan of lining piping 3
9 ”. In this case, "Seawater system removal process 4 of regular inspection
"0" is incorporated. Also, if repairs are necessary, the local inspection plan will be reviewed. By reviewing the inspection plan, a “planned inspection schedule 41 for lining pipe during regular inspection”, a “spool removal procedure 42 for lining pipe”, and an “inner inspection procedure for lining pipe during regular inspection” are created. As a result, the "inside surface inspection data 44 of the lining pipe" and the "lining pipe repair record data" are obtained again, and this is repeated.

Thus, the lining state of the lining in the pipe can be inspected in real time during the operation of the nuclear power plant, and the deterioration state such as the peeling of the lining can be detected at the initial stage, and the repair plan can be planned during the plant operation. It is also possible to carry out an efficient lining inspection of pipes.

[0034]

As described above, according to the present invention, ultrasonic pulses are transmitted from the outside of the pipe to the lining inside the pipe, and the lining echo reflected from the lining surface is monitored, so that the lining can be obtained even during plant operation. It is possible to monitor the laying state of the lining, detect the deterioration state such as the peeling of the lining in the initial stage, and plan and execute an efficient inspection plan.

Further, by combining the ultrasonic monitoring during the plant operation and the visual monitoring during the plant regular inspection, the inspection time can be shortened, the work can be facilitated, and the work cost can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a pipe inspection device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is an ultrasonic echo waveform diagram for explaining the operation of the pipe inspection device.

FIG. 4 is a sectional view showing a pipe inspection device according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing a pipe inspection device according to a third embodiment of the present invention.

FIG. 6 is a front view showing a pipe inspection device according to a third embodiment of the present invention.

FIG. 7 is a schematic block diagram showing a pipe inspection device according to a fourth embodiment of the present invention.

FIG. 8 is a side view showing a pipe inspection method according to a fifth embodiment of the present invention.

FIG. 9 is a schematic block diagram showing a pipe inspection system of the present invention.

FIG. 10 is a system sequence diagram showing a pipe inspection system of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Piping, 2 ... Bending part delay material, 3 ... Lining, 4 ... Piezoelectric ultrasonic transducer, 4a, 4b ... Oblique angle ultrasonic transducer, 5 ... Delay material, 6 ... Ultrasonic transceiver, 7 ... Waveform display Device, 8 ... Signal processing device, 9, 12,
15 ... Ultrasonic pulse, 11, 14 ... Ultrasonic reflection echo,
16 ... Lining surface, 17 ... Lining echo, 1
8, 19 ... Waveform of ultrasonic echo, 20 ... Waveform of lining echo, 21 ... Pipe inner surface inspection jig, 22 ... Signal transmitter / receiver, 23 ... Office, 24 ... Signal transmitter / receiver, 25 ... Personal computer.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2G047 AB01 AC01 BA03 BB01 BB02                       BC07 CA01 EA09 EA12 EA19                       GA03 GA21 GB29                 2G075 BA03 CA13 CA36 DA16 FA16                       FC14 GA09 GA15 GA16

Claims (7)

[Claims] 1. A piezoelectric ultrasonic transducer provided on the outer side of a bent portion of a pipe whose inner surface is lined,
An ultrasonic transceiver that transmits a pulse to the piezoelectric ultrasonic transducer and receives an ultrasonic reflection echo,
The ultrasonic pulse transmitted from the piezoelectric ultrasonic transducer toward the bent portion of the pipe is transmitted through the boundary between the pipe and the lining material and the ultrasonic reflection echo reflected from the boundary between the pipe and the lining material, and propagates from the lining surface. A pipe inspection device comprising: a signal processing circuit for monitoring the lining installation state in a bent portion of a pipe based on a waveform of a reflected ultrasonic reflection echo. 2. The pipe inspection apparatus according to claim 1, wherein the ultrasonic wave transmitting surface of the piezoelectric ultrasonic transducer has a curvature corresponding to the shape of the bent portion of the pipe. 3. The piezoelectric ultrasonic transducer comprises two ultrasonic transducers for oblique angles, one for transmitting and the other for receiving, provided outside the bent portion of the pipe. The described pipe inspection device. 4. The pipe inspection device according to claim 3, wherein the two ultrasonic transducers for oblique angles are provided separately from each other along the axial direction of the pipe. 5. The pipe inspection apparatus according to claim 3, wherein the two ultrasonic transducers for oblique angles are provided separately from each other along the circumferential direction of the pipe. 6. The two ultrasonic transducers for oblique angles having different incident angles are provided on one side of the bent portion of the pipe, spaced apart along the axial direction of the pipe. The described pipe inspection device. 7. A means for inspecting the inner surface of a straight pipe portion of a pipe by removing the pipe spool when the pipe is not used, and inserting a pipe inner surface inspection jig from the pipe opening, and a pipe when the pipe is in use Whether or not there is lining peeling by transmitting ultrasonic waves from the outside to the bent part and monitoring the reflected echo,
Or a pipe inspection method comprising a means for inspecting the installed condition.