JP5634072B2 - Piping / equipment monitoring device and method - Google Patents

Description

  The present invention relates to a pipe / equipment monitoring apparatus and method for detecting defects such as thinning and cracks in pipes or equipment that are inspection objects using an electromagnetic ultrasonic probe.

  Corrosion due to coolant and erosion due to erosion that occur during operation of piping or equipment of nuclear or thermal power plants are inspected at regular intervals using ultrasonic waves during regular inspection.

In recent years, in order to cope with the problem of global warming, it has been desired to improve the operation rate of nuclear power generation, which is low CO ₂ power generation, and it is necessary to extend the regular inspection cycle from the current 13 months.

  Moreover, in the conventional plant, in order to further improve the facility utilization rate, it is expected that the plant will increase the output by 5% or more in the future.

  In the future, when a long-term cycle operation of 13 months or more or a plant power increase of 5% or more is carried out, it is difficult to detect a thinning that develops abnormally within the inspection cycle. Longer inspection cycles and increased coolant (water) flow rates due to increased plant output cannot eliminate the possibility of changes in the corrosive environment and increased erosion.

  When unexpected thinning of the pipe or equipment occurs during plant operation, and coolant leaks from this thinning point, in order to stop the plant unplanned and restore the leakage location, It takes a lot of time and money to restart the plant. For this reason, application of state monitoring during plant operation is being promoted from the viewpoint of improving the utilization rate of plant equipment and ensuring plant reliability, and in order to detect and prevent the risk of coolant leakage early, Monitoring equipment thinning is essential.

  In addition, the method of permanently installing the sensor has problems such as cables and power supplies, and it is difficult to monitor the equipment status of piping or equipment over the entire plant.

  Therefore, there is no need for an external power supply or transmission cable, and as a technique for monitoring the thinning of pipes or equipment during plant operation, multiple IC tags are installed in strips in the circumferential direction at locations where thinning is likely to occur, and distortion due to fluid in the pipe Has been disclosed (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2006-283377

  However, in the piping state monitoring technology described in Patent Document 1, the piping state (such as cracks and thinning) is indirectly monitored by detecting piping distortion using an IC tag attached to the piping. Since the pipe state is not directly monitored, it cannot always be accurately detected.

The object of the present invention has been made in consideration of the above-mentioned circumstances. During operation of a plant, defects, particularly surface cracks, which have occurred in piping or equipment constituting the plant are detected directly and early. It is another object of the present invention to provide a piping / equipment monitoring apparatus and method capable of monitoring the soundness of piping or equipment.

The pipe / equipment monitoring apparatus according to the present invention is an electromagnetic ultrasonic probe that is attached to the outer surface of a pipe or equipment with a permanent magnet and transmits / receives ultrasonic waves, and measurement data measured by the electromagnetic ultrasonic probe. Wireless transmission means for transmitting the power, self-feeding means for feeding power to the electromagnetic ultrasonic probe and the wireless transmission means, and signal processing means for receiving the measurement data and obtaining a defect, and the electromagnetic ultrasonic wave the probe consists excited and receiving coils are wound so as to include the permanent magnet Rutotomoni, the axis of the excitation and reception coils, in a plane tangent to the outer surface of the pipe or equipment The ultrasonic wave that is provided perpendicular to the axial direction of the pipe or device and that is excited and transmitted / received by the electromagnetic ultrasonic probe is energized to the outside of the pipe or device when the excitation / reception coil is energized. Excited on the surface Current and the permanent magnet is generated by the Lorentz force caused by the magnetic field formed in the outer surface of the pipe or equipment, a ultrasonic transverse waves propagating through the outer surface of the pipe or equipment, the signal processing means Is a surface crack generated in the pipe or equipment.

According to the piping / equipment monitoring apparatus and method according to the present invention, using ultrasonic waves from an electromagnetic ultrasonic probe that is always attached to the piping or equipment, defects generated in the piping or equipment during operation of the plant , In particular, surface cracks can be detected directly and early to monitor the soundness of piping or equipment.

BRIEF DESCRIPTION OF THE DRAWINGS The block diagram which shows 1st Embodiment of the piping and apparatus monitoring apparatus which concerns on this invention. The block diagram which shows the electromagnetic ultrasonic probe of FIG. The block diagram which shows an example of the harvester power supply of FIG. The block diagram which shows 2nd Embodiment of the piping and apparatus monitoring apparatus which concerns on this invention. The V arrow line view of FIG.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, the present invention is not limited to these embodiments.

[A] First embodiment (FIGS. 1 to 3)
A piping / equipment monitoring apparatus 10 shown in FIG. 1 includes an electromagnetic ultrasonic transducer 11 (EMAT: Electromagnetic Acoustic Transducer) mounted on a pipe 1 as an inspection object, which constitutes a plant such as a nuclear power plant or a thermal power plant. ), And the ultrasonic wave received by the electromagnetic ultrasonic probe 11 is used to detect defects generated in the pipe 1, particularly thinning.

  Here, the pipe 1 is in a high temperature state of 200 ° C. to 600 ° C. when a high temperature fluid (for example, high temperature steam, high temperature pressurized water, etc.) flows inside. For example, the pipe 1 is about 300 ° C. in a nuclear power plant.

  In addition, the pipe 1 has its inner surface shaved by corrosion and erosion due to the fluid flowing inside, and a thinning phenomenon occurs. The pipe / equipment monitoring device 10 directly detects the thinning generated in the pipe 1 by quantitatively measuring the plate thickness of the pipe 1.

  The pipe / equipment monitoring device 10 includes a sensor unit 10A that is always attached to the pipe 1 that is an inspection object, and a signal processing unit 10B that is installed away from the sensor unit 10A. The sensor unit 10A includes an electromagnetic ultrasonic probe 11, a wireless transmitter 12 as wireless transmission means, a harvester power supply 13 as self-power supply means, and a capacitor 14. The electromagnetic ultrasonic probe 11, the wireless transmitter 12, and the capacitor 14 are built in the sensor casing 15, and the harvester power supply 13 is attached to the outer surface of the sensor casing 15, for example. Further, the signal processing unit 10B includes a repeater 21 and a calculator 22 which will be described later.

  As shown in FIGS. 1 and 2, the electromagnetic ultrasonic probe 11 includes a permanent magnet 17, an excitation / reception coil 18, and a potentiometer 16, and generates longitudinal wave ultrasonic waves P <b> 1 as described later. Excitation is transmitted, and longitudinal wave ultrasonic pulse echo P2 is received. The longitudinal ultrasonic waves P1 and the ultrasonic pulse echoes P2 are suitable for measuring the plate thickness of the pipe 1, and thereby the thinning generated in the pipe 1 is detected. In addition, a thinning part is shown with the code | symbol 4 in FIG.1 and FIG.2.

  Since the temperature of the pipe 1 is a high temperature of several hundreds of degrees Celsius, the permanent magnet 17 is a high-temperature magnet that has a Crow point of 500 ° C. or higher and a small decrease in magnetic force even at a high temperature of 200 ° C. to 600 ° C. . For example, the permanent magnet 17 may be a samarium / cobalt magnet or an aluminum / nickel / cobalt magnet. By installing the permanent magnet 17 perpendicularly to the outer surface 2 of the pipe 1, a magnetic field 19 parallel to the axial direction M of the pipe 1 is formed on the outer surface 2 of the pipe 1.

  In general, an ultrasonic probe is bonded to an inspection object by a plant such as water or grease. However, if the piping 1 as the inspection object is in a high temperature state of several hundred degrees Celsius, the coplanar is volatilized. It will leak. In the present embodiment, the sensor unit 10 </ b> A containing the electromagnetic ultrasonic probe 17 is always attached to the outer surface of the pipe 1 by the action of the magnetic force of the permanent magnet 17.

  The excitation / reception coil 18 has an axis O arranged parallel to the axial direction M of the pipe 1. When a high-frequency pulse current flows through the excitation / reception coil 18 by the power stored in the capacitor 14 from the harvester power supply 13, a pulsed eddy current 20 (FIG. 2) is excited on the outer surface 2 of the pipe 1. . A Lorentz force is generated by the eddy current 20 and the magnetic field 19 generated on the outer surface 2 of the pipe 1, and this Lorentz force becomes a pulsed impact force in a direction perpendicular to the outer surface 2 of the pipe 1. From the outer surface 2, a pulsed longitudinal ultrasonic wave P1 is generated in the vertical direction.

  This longitudinal wave ultrasonic wave P1 is reflected by the inner surface 3 of the pipe 1 (including the inner surface of the thinned portion 4), reaches the outer surface 2 of the pipe 1 as an ultrasonic pulse echo P2, and this outer surface 2 Vibrates the magnetic field 19. Then, the vibration of the magnetic field 19 excites a pulsed potential difference in the excitation / reception coil 18 according to Faraday's law. The time difference from when the excitation / reception coil 18 is first energized with the ultrasonic pulse current to when the above-described potential difference is excited in the excitation / reception coil 18 is the total propagation time of the ultrasonic wave P1 and the ultrasonic pulse echo P2. It becomes.

  The sound speeds of the longitudinal ultrasonic wave P1 and the ultrasonic pulse echo P2 propagating through the cross section of the pipe 1 are equal and are determined by the material property values. In the case of steel, it is generally about 5000 m / s. Therefore, it becomes possible to directly measure the plate thickness of the pipe 1 in a non-contact state with the pipe 1 from the speed of sound and the total propagation time of the ultrasonic wave P1 and the ultrasonic pulse echo P2. 1 can be detected.

  The frequency of the ultrasonic wave P1 excited by the excitation / reception coil 18 is set by adjusting the frequency or pulse width of the ultrasonic pulse current supplied to the excitation / reception coil 18. Therefore, by setting the frequency of the ultrasonic wave P1 within a range of several hundred kHz to several MHz, it becomes possible to control the measurement accuracy of the plate thickness (that is, thinning) of the pipe 1 within 1 mm.

  In practice, the pulsed potential difference excited in the excitation / reception coil 18 by the vibration of the magnetic field 19 based on the ultrasonic pulse echo P <b> 2 is measured by the potentiometer 16 connected to the excitation / reception coil 18. This measurement data is transmitted to the computing unit 22 that also constitutes the signal processing unit 10B through the repeater 21 that constitutes the signal processing unit 10B, using the wireless transmitter 12 connected to the potentiometer 16. The calculator 22 calculates a time difference from when the excitation / reception coil 18 is first energized with a high-frequency pulse current until the potential difference is excited, and the thickness of the pipe 1 is measured based on the time difference. , Seek its thinning situation. That is, the arithmetic unit 22 of the signal processing unit 10 </ b> B obtains the thinning state from the measurement data obtained by the electromagnetic ultrasonic probe 11.

  As described above, the sensor unit 10A is always attached to the pipe 1, and in particular, the electromagnetic ultrasonic probe 11 is always attached, so that the state of thinning of the pipe 1 during operation of the nuclear power plant or the thermal power plant is monitored. Thus, this thinning is detected at an initial stage before the leakage of the high-temperature fluid (for example, coolant) flowing in the pipe 1.

  By the way, the harvester power supply 13 in the sensor unit 10 </ b> A has a self-power generation function that generates power using a Peltier element based on the temperature of the pipe 1 or generates power using a piezo element based on vibration of the pipe 1. The electric power generated by the harvester power supply 13 passes through the capacitor 14, that is, is stored in the capacitor 14, and is then fed to the electromagnetic ultrasonic probe 11 and the wireless transmitter 12. An example of the harvester power supply 13 using the Peltier element 23 is shown in FIG.

  In other words, the outer surface 2 of the high-temperature pipe 1 kept at several hundred degrees Celsius is covered with the heat insulating material 24 and kept warm against the outside air of several tens degrees Celsius. Then, the base end of the heat pipe 25 is fixed to the outer surface 2 of the high-temperature pipe 1, and the back surface 23 </ b> B of the Peltier element 23 is bonded to the tip of the heat pipe 25. Thereby, the heat of the high-temperature piping 1 is efficiently transferred to the back surface 23 </ b> B of the Peltier element 23. A heat sink 26 is bonded to the surface 23A of the Peltier element 23. Thereby, the surface 23A of the Peltier element 23 is efficiently cooled by the outside air.

  Therefore, between the back surface 23B of the Peltier element 23 to which the heat of the high-temperature pipe 1 having a temperature of several hundred degrees C. is transferred and the surface 23A of the Peltier element 23 cooled by the outside air of several tens degrees C. As a result, a power of several tens of mW or more can be obtained even with a rectangular Peltier element 23 of several centimeters.

  During plant operation, the temperature of the outer surface 2 of the pipe 1 is kept at several hundred degrees Celsius or higher and the outside air temperature is several tens of degrees Celsius. It becomes possible to constantly obtain power for driving the touch element 11 and the wireless transmitter 12. When larger electric power is required, it can be dealt with by increasing the capacity of the Peltier element 23, the heat pipe 25 and the heat sink 26.

  With the configuration as described above, according to the present embodiment, the following effects (1) to (4) are achieved.

  (1) Reduction generated in the pipe 1 during plant operation using longitudinal ultrasonic waves P1 and ultrasonic pulse echoes P2 transmitted and received by the electromagnetic ultrasonic probe 11 of the sensor unit 10A always attached to the pipe 1 The meat is directly detected, the state of the pipe 1 is monitored, and the thinning is detected at the initial stage. For this reason, the thinning produced in the pipe 1 constituting the operating plant can be detected accurately and early, and the soundness of the pipe 1 can be monitored. As a result, for example, an event in which the coolant leaks from the pipe 1 due to the thinning of the pipe 1 of the nuclear power plant can be prevented, and an unplanned stop of the plant can be avoided.

  (2) Since the sensor unit 10A of the piping / equipment monitoring device 10 is equipped with the electromagnetic ultrasonic probe 11, it is possible to eliminate the need for a coplant and to detect defects including thinning of the piping 1 in a non-contact state. it can. Moreover, since the permanent magnet 17 which comprises the electromagnetic ultrasonic probe 11 used the magnet for high temperature with little fall of magnetic force with respect to the high temperature of 200 to 600 degreeC, the electromagnetic ultrasonic probe 11 is used. The sensor unit 10 </ b> A including the above can suitably detect defects including the thinning of the high-temperature pipe 1 of the nuclear power plant or the thermal power plant.

  (3) Potential difference data (measurement data) measured by the potentiometer 16 of the electromagnetic ultrasonic probe 11 is wirelessly transmitted to the repeater 21 using the wireless transmitter 12, and is subjected to arithmetic processing by the arithmetic unit 22 and piping. Since 1 thinning is detected, an instrumentation cable can be dispensed with. As a result, it is possible to install the sensor unit 10A between the pipe 1 and the heat insulating material 24. In this case, since the instrumentation cable does not exist, the workability of installation of the sensor unit 10A is improved. Furthermore, an increase in instrumentation cables in the local building can be avoided.

  (4) Since the electric power generated by the harvester power supply 13 having a self-power generation function is supplied to the electromagnetic ultrasonic probe 11 and the wireless transmitter 12, the electromagnetic ultrasonic probe 11 and the wireless transmitter 12 are supplied. It is possible to eliminate the need for a power cable for supplying power to the power supply and a battery for supplying power to the electromagnetic ultrasonic probe 11 and the wireless transmitter 12. As a result, power cable laying work and periodic battery replacement work can be eliminated.

[B] Second embodiment (FIGS. 4 and 5)
FIG. 4 is a block diagram showing a second embodiment of the piping / equipment monitoring apparatus according to the present invention. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description is simplified or omitted.

The pipe / equipment monitoring apparatus 30 of the present embodiment is different from the pipe / equipment monitoring apparatus 10 of the first embodiment in that the pipe 1 is excited by the electromagnetic ultrasonic probe 31 built in the sensor unit 30A. The ultrasonic wave S1 to be received and the ultrasonic pulse echo S2 to be received are both transverse waves, and these ultrasonic waves S1 and the ultrasonic pulse echo S2 are used to detect defects generated in the pipe 1, particularly the surface crack 5. is there.

  The surface crack 5 is a stress-corrosion cracking (SSC), a fatigue defect, a surface defect in a weld overlay, or the like. Further, the signal processing unit (not shown) of the piping / equipment monitoring device 30 is configured to include the repeater 21 and the arithmetic unit 22 as in the first embodiment.

  The electromagnetic ultrasonic probe 31 includes a permanent magnet 32, an excitation / reception coil 33, and a potentiometer 16. The permanent magnet 32 is a high-temperature magnet like the permanent magnet 17 of the first embodiment, but is installed on the outer surface 2 of the pipe 1 so that a magnetic field 34 perpendicular to the axial direction M of the pipe 1 is generated. , Formed on the outer surface 2 of the pipe 1. Further, the sensor unit 30 </ b> A containing the electromagnetic ultrasonic probe 31 is always attached to the pipe 1 by the magnetic force of the permanent magnet 32.

  The excitation / reception coil 33 is wound so as to enclose the permanent magnet 32 from the near side to the far side in FIG. 4, and its axis Q is in the axial direction M of the pipe 1 as shown in FIG. 5. On the other hand, they are arranged orthogonally in a horizontal plane.

  When a high-frequency pulse current flows through the excitation / reception coil 33 by the power stored in the capacitor 14 from the harvester power supply 13, a pulsed eddy current 35 is excited on the outer surface 2 of the pipe 1. The Lorentz force is generated by the eddy current 35 and the magnetic field 34 generated on the outer surface 2 of the pipe 1, and the Lorentz force is along the axial direction M of the pipe 1 in a direction parallel to the outer surface 2 of the pipe 1. A pulsed transverse wave ultrasonic wave S1 is generated.

  The transverse ultrasonic wave S1 is reflected by the surface crack 5 generated in the pipe 1 to become an ultrasonic pulse echo S2, and vibrates the magnetic field 34 on the outer surface 2 of the pipe 1. Then, the vibration of the magnetic field 34 excites a pulsed potential difference in the excitation / reception coil 33 according to Faraday's law. The time difference from when the excitation / reception coil 33 is first energized with the ultrasonic pulse current until the above-described potential difference is excited in the excitation / reception coil 33 is the propagation time of the ultrasonic wave S1 and the ultrasonic pulse echo S2. Summed up.

  The sound velocities of the transverse wave ultrasonic wave S1 and the ultrasonic pulse echo S2 propagating on the outer surface 2 of the pipe 1 are both equal and determined by the material property values. In the case of steel, it is generally about 3000 m / s. Therefore, the location and size of the surface crack 5 generated in the pipe 1 are detected from this sound speed and the total propagation time of the ultrasonic wave S1 and the ultrasonic pulse echo S2.

  Also in the present embodiment, in practice, the pulsed potential difference excited in the excitation / reception coil 33 by the vibration of the magnetic field 34 based on the ultrasonic pulse echo S2 is the potentiometer connected to the excitation / reception coil 33. 16 is measured. This measurement data is transmitted to the computing unit 22 via the repeater 21 using the wireless transmitter 12 connected to the potentiometer 16. The calculator 22 calculates a time difference from when the excitation / reception coil 33 is first energized with the high-frequency pulse current until the above-described potential difference is excited, and the surface crack 5 generated in the pipe 1 based on the time difference. Is detected.

  Also in the sensor unit 30A of the pipe / equipment monitoring apparatus 30, the electromagnetic ultrasonic probe 31 is always attached to the pipe 1, the state of the surface crack 5 of the pipe 1 during plant operation is monitored, and the surface crack 5 is initially detected. Detected in stages.

  With the configuration as described above, the present embodiment has the same effects as the effects (2) to (4) of the first embodiment, and also has the following effect (5).

  (5) Surface cracks generated in the pipe 1 during plant operation using the transverse ultrasonic wave S1 and the ultrasonic pulse echo S2 transmitted and received by the electromagnetic ultrasonic probe 31 of the sensor unit 30A always mounted on the pipe 1 5 is directly detected, the state of the pipe 1 is monitored, and the surface crack 5 is detected in the initial stage. For this reason, the surface crack 5 which arose in the piping 1 which comprises the plant in operation can be detected correctly and early, and the soundness of the piping 1 can be monitored.

  In both the first and second embodiments, the pipe / equipment monitoring devices 10 and 30 have described the case where the inspection target for detecting defects using ultrasonic waves is the pipe 1, but the equipment other than the pipe 1 is used. May be.

1 Piping 4 Thinning point (defect)
5 Surface cracks (defects)
DESCRIPTION OF SYMBOLS 10 Piping / equipment monitoring device 11 Electromagnetic ultrasonic probe 12 Wireless transmitter 13 Harvester power supply 17 Permanent magnet 18 Excitation / reception coil 30 Piping / equipment monitoring device 31 Electromagnetic ultrasonic probe 32 Permanent magnet 33 Excitation / reception coil P1 Ultrasonic P2 Ultrasonic Pulse Echo S1 Ultrasonic S2 Ultrasonic Pulse Echo

Claims (2)

An electromagnetic ultrasonic probe that is attached to the outer surface of a pipe or device with a permanent magnet and transmits and receives ultrasonic waves;
Wireless transmission means for transmitting measurement data measured by the electromagnetic ultrasonic probe;
Self-power feeding means for feeding power to the electromagnetic ultrasonic probe and the wireless transmission means;
Signal processing means for receiving the measurement data and obtaining a defect, and
The electromagnetic ultrasonic probe is configured excited and receiving coils are wound so as to include the permanent magnet Rutotomoni, the axis of the excitation and reception coils, the outer surface of the pipe or equipment In the plane that touches, provided perpendicular to the axial direction of the pipe or device,
The ultrasonic waves excited and transmitted / received by the electromagnetic ultrasonic probe are eddy currents excited on the outer surface of the pipe or device when the excitation / reception coil is energized, and the permanent magnet is connected to the pipe or generated by Lorentz force generated by the magnetic field formed in the outer surface of the device, a ultrasonic transverse waves propagating through the outer surface of the pipe or equipment,
The pipe / equipment monitoring apparatus, wherein the defect required by the signal processing means is a surface crack generated in the pipe or equipment. 2. The piping / equipment monitoring apparatus according to claim 1, wherein the permanent magnet is a samarium / cobalt magnet or an aluminum / nickel / cobalt magnet.

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