JP2018132358A - Corrosion detection system, piping management system, and corrosion detection method - Google Patents

Abstract

Provided are a corrosion detection system, a pipe management system, and a corrosion detection method for easily detecting the presence or absence of corrosion on the outer surface of a coated pipe without removing the coating on the outer surface of the coated pipe. To do. A corrosion detection system according to the present invention includes an impact mechanism that applies impact to a pipe, a vibration sensor that detects an impact wave that propagates to the pipe due to impact, and is attached to an outer surface of a covering material that covers the pipe; Intensity of the waveform at the same measurement time in the waveform differential operation unit that differentiates the waveform data of the impact wave acquired by the vibration sensor, and even-order differential data or odd-order differential data of the waveform data calculated by the differential operation unit A waveform comparison unit that calculates a correlation value of data and a corrosion determination unit that determines the presence or absence of corrosion on the outer surface of the pipe by the correlation value. [Selection] Figure 2

Description

  The present invention relates to a corrosion detection system, a pipe management system, and a corrosion detection method for detecting corrosion of a surface of a pipe formed of metal.

Conventionally, pipes have been detected in order to prevent leakage accidents in which fluid leaks out of the pipe due to corrosion of the outer surface of the pipe through which fluid flows, such as oil feed pipes used in refinery facilities (for example, , See Patent Document 1).
In Patent Document 1, since pipes covered with piping, such as pipes kept warm with a heat insulating material, cannot be visually detected from the outside by coating, corrosion of the outer surface of the pipe is detected by a guide method using ultrasonic waves. Is doing.

JP 2004-301540 A

However, in the guide method in which corrosion of the outer surface of a pipe covered with a heat insulating material or the like is detected nondestructively as described above, it is necessary to remove the heat insulating material and expose a predetermined range of the pipe in order to apply ultrasonic waves to the pipe. There is.
Therefore, in Patent Document 1, when the corrosion of the outer surface of the pipe is detected, the work is carried out while performing the work of dismantling and removing the heat insulating material for each detectable range by the guide method. Is long and expensive.

  The present invention has been made in view of such circumstances, and a corrosion detection system that easily detects the presence or absence of corrosion on the outer surface of the coated pipe without removing the coating on the outer surface of the coated pipe. An object of the present invention is to provide a pipe management system and a corrosion detection method.

  The present invention has been made to solve the above-described problems, and the corrosion detection system of the present invention includes a striking mechanism that applies striking to the pipe, and a pipe that detects a striking wave that propagates to the pipe by the striking. A vibration sensor that is attached to the outer surface of the covering material that coats the waveform, a waveform differential calculation unit that differentiates the waveform data of the hitting wave acquired by the vibration sensor, and even-order differential data of the waveform data calculated by the waveform differential calculation unit Or, between odd-order differential data, a waveform comparison unit that calculates a correlation value of intensity data of waveforms at the same measurement time, and a corrosion determination unit that determines the presence or absence of corrosion on the outer surface of the pipe by the correlation value It is characterized by providing.

  In the corrosion detection system according to the present invention, the vibration sensor responds to a change in the state of the outer surface of the pipe at the interface via the interface between the outer surface of the pipe and the covering material. It is characterized by detecting as a changing waveform.

  In the corrosion detection system of the present invention, the vibration sensor has a waveform during a period from when the intensity of the waveform of the hitting wave becomes equal to or higher than a predetermined value until the pipe generates resonance of the hitting wave due to the hitting, It is acquired as the waveform data.

  In the corrosion detection system of the present invention, the waveform comparison unit normalizes each of the even-order differential data or the odd-order differential data that uses the correlation value for calculation, based on the maximum intensity of each amplitude, A correlation value is calculated.

  The corrosion detection system of the present invention is characterized in that the vibration sensor is a device having a wireless function (IoT (internet of things) device).

  The piping management system of the present invention is a piping management system using any one of the corrosion detection systems described above, a piping management server, a facility database for storing a design drawing showing the arrangement of piping for each predetermined facility, A management database storing a detection result of the pipe and a detection schedule of the pipe, and the pipe management server performs the piping of the pipe performed by the corrosion detection system corresponding to the design drawing based on the detection schedule. The detection result is written and stored in a management database.

The corrosion detection method of the present invention includes a striking application process in which striking is applied to piping by a striking mechanism,
The vibration sensor detects a striking wave propagating to the pipe by the striking, the striking wave detection process attached to the outer surface of the covering material covering the pipe, and the waveform differential operation unit acquired by the vibration sensor. The waveform differential calculation process for differentiating the waveform data of the waveform, and the waveform comparison unit between the even-numbered differential data or the odd-numbered differential data of the waveform data calculated by the waveform differential calculation unit, the intensity of the waveform at the same measurement time A waveform comparison process for calculating a correlation value of data and a corrosion determination process in which the corrosion determination unit determines the presence or absence of corrosion on the outer surface of the pipe based on the correlation value.

  According to the present invention, there is provided a corrosion detection system, a pipe management system, and a corrosion detection method for easily detecting the presence or absence of corrosion on the outer surface of a coated pipe without removing the coating on the outer surface of the coated pipe. can do.

It is a conceptual diagram explaining the principle of the detection of the corrosion in the outer surface of piping by the frequency change of the vibration wave which arises by the applied impact in this invention. It is a figure which shows the structural example of the corrosion detection system by one Embodiment in this invention. It is a figure which shows the structural example of the measurement table memorize | stored in the memory | storage part 16 in this embodiment. It is a figure explaining calculation of the correlation value of the waveform data and 2nd-order differential waveform data in this embodiment. It is a figure explaining calculation of the correlation value of the waveform data and 2nd-order differential waveform data in this embodiment. It is a flowchart which shows the example of a flow operation | movement of the process which detects the presence or absence of corrosion on the outer surface of piping using the corrosion detection system in this embodiment. It is a figure which shows the structural example of the piping management system using the corrosion detection system in this embodiment.

The present invention applies vibration to a member in contact with a pipe such as a steel pipe when detecting the presence or absence of corrosion on the outer surface of the pipe covered with a heat insulating material, and vibrations generated by the applied blow. The wave is measured on the coated surface, and the presence or absence of corrosion in contact is detected based on the degree of frequency change of the vibration wave.
FIG. 1 is a conceptual diagram illustrating the principle of detection of corrosion on the outer surface of a pipe due to a change in frequency of a vibration wave generated by an applied impact in the present invention. FIG. 1A shows a cross section of the pipe 101 cut along a plane parallel to the arrangement direction of the pipe 101.

  In the following description, the covering material covering the pipe will be described as a heat insulating material. The heat insulating material 102 is, for example, a solid oxide (calcium silicate), has a shape obtained by cutting a cylinder having a predetermined thickness along a plane including the central axis, and the pipe 101 is inserted into the cylinder. Assemble and use. In addition, the covering material such as the heat insulating material 102 needs to be formed of a material that can transmit the vibration wave propagating to the pipe 101 via the interface in contact with the pipe 101.

  In FIG. 1A, the pipe 201 is hit against the flange 201 that connects the pipes 101 to each other. The flange is exposed from the heat insulating material 102, and it is not necessary to remove the heat insulating material 102 as a coating, and an impact can be applied to the pipe 101. In addition to the flange 201, a support member (a shoe (SHOE), a base for fixing / supporting the pipe, a frame, etc.) 202 that supports the pipe 101 to be disposed is also in direct contact with the pipe 101 and has come into contact therewith. There is an exposed portion exposed from the heat insulating material 102 covered by the support member 202, and it can be used to apply a blow to the pipe 101.

When the corroded area (hereinafter referred to as rust hump) 501 is not generated on the outer surface of the pipe 101, a blow wave (shock wave) that propagates as vibration through the pipe 101 due to the hit (impact) applied to the flange 201 is The vibration sensor 11 </ b> _A detects the waveform without changing at the interface between the outer surface of 101 and the heat insulating material 102, that is, as a normal waveform.
On the other hand, when the rust hump 501 is generated on the outer surface of the pipe 101, the waveform of the striking wave changes in the area of the rust hump 501 and a new waveform shape is generated. The waveform of the wave is synthesized (superimposed) and detected by the vibration sensor 11_B as a non-normal waveform of the synthesized wave different from the normal waveform detected in a state where the rust hump 501 is not generated. Hereinafter, the vibration sensor 11 </ b> _A, the vibration sensor 11 </ b> _B, and the vibration sensor 11 </ b> _C will be simply referred to as the vibration sensor 11 when collectively referred to.

The inventor of the present invention has found a method for detecting rust humps using this hitting wave through an experiment using piping in an actual refinery facility.
The above-mentioned abnormal waveform is observed in a predetermined range where the rust hump 501 is generated (for example, a width of about 1 m before and after the position where the rust hump 501 is formed), and the normal waveform is outside the predetermined range. Observed.
The vibration wave having an abnormal waveform does not propagate through the pipe 101 but propagates as a radiated wave in the heat insulating material 102 from the interface between the heat insulating material 102 and the pipe 101 toward the outer surface of the heat insulating material 102.

In the case of the heat insulating material, a sheet metal cover (not shown) is provided on the outer surface of the heat insulating material in order to fix the heat insulating material.
FIG. 1B shows a cross section obtained by cutting the pipe 101 at the position of the line AA on a plane perpendicular to the arrangement direction of the pipe 101.
The outer surface of the heat insulating material 102 is covered with the sheet metal 103, and the vibration sensor 11_C (also other vibration sensors) that detects the striking wave is a striking wave that propagates through the pipe 101 via each of the sheet metal 103 and the heat insulating material 102. Detect the waveform.
The support member 202 is in contact with a portion supported by the pipe 101, and a hitting wave generated by hitting applied to itself can be propagated to the pipe 101.

  The space 102 </ b> B is a space formed between the outer surface of the pipe 101 and the inner surface of the heat insulating material 102. The striking wave propagating through the pipe 101 is not transmitted to the heat insulating material 102 through the space 102B. The rust hump 501 is generated due to moisture that has entered from the gap between the heat insulating material 102, but is likely to be generated at the interface between the pipe 101 and the heat insulating material 102 because it is caused by condensation at the interface between the pipe 101 and the heat insulating material 102. For this reason, by detecting the rust hump 501 at the interface between the pipe 101 and the heat insulating material 102, the same result as that for detecting all the rust humps 501 on the outer surface of the pipe 101 can be obtained.

FIG. 2 is a diagram illustrating a configuration example of a corrosion detection system according to an embodiment of the present invention. The corrosion detection system 1 shown in FIG. 2 includes a corrosion detection device 10, a vibration sensor 11, a striking mechanism 18, and a striking body 18B.
The corrosion detection apparatus 10 includes a vibration measurement unit 12, a waveform differentiation calculation unit 13, a waveform comparison unit 14, a corrosion determination unit 15, a storage unit 16, and an impact control unit 17.

  The vibration sensor 11 may be any sensor that is formed from a vibration acceleration sensor, a vibration speed sensor, an eddy current displacement sensor, and the like and can detect vibration. The vibration sensor 11 is appropriately disposed at the detection position of the pipe 101 that is a target for detecting rust humps, and the waveform of the striking wave propagating to the pipe 101 is changed to the interface between the pipe 101 and the heat insulating material 102 and the heat insulating material 102. The vibration waveform is detected through each of the sheet metals 103. Here, after the intensity of the vibration waveform to be detected becomes a preset intensity, the vibration sensor 11 transmits the waveform data of the vibration waveform detected during a predetermined period to the vibration measuring unit 12 together with its own identification information. As a transmission medium for communication, data is output by wire or wireless (for example, a wireless local area network (LAN)).

  The predetermined period is, for example, a period from when a striking wave is applied to the pipe 101 until resonance occurs. The wave number is, for example, about 3 to 4 waves from the experimental results. Further, when the covering material covering the pipe 101 is the heat insulating material 102, the vibration sensor 11 may be attached to the sheet metal 103 with a magnet because it is covered with a sheet metal for protecting and fixing the outer surface of the heat insulating material 102. good. Further, when the covering material is formed of a non-magnetic material that does not attach to the magnet, the vibration sensor 11 is provided with a fixture, and the vibration sensor 11 is fixed to the outer surface of the covering material to measure the vibration waveform. Also good.

The vibration measurement unit 12 measures the set of the waveform data indicating the vibration waveform supplied from the vibration sensor 11, the identification information for identifying each vibration sensor 11, and the reception time when the waveform data is received in the storage unit 16. Each time waveform data is sequentially supplied to the table, it is written and stored.
The waveform differential calculation unit 13 sequentially reads out the waveform data from the storage unit 16, second-order differentiation of the read-out waveform data, and writes and stores the second-order differential waveform data in the storage unit 16 corresponding to the original waveform data. . At this time, the waveform differential calculation unit 13 matches the polarity (+/−) of the numerical value to the waveform data with respect to the obtained second-order differential waveform data so that the waveform comparison unit 14 described later can calculate the correlation value. Therefore, “−1” is multiplied.

That is, the waveform data (0th-order differential) of the striking wave is expressed by the following equation (1).
f (t) = sin (ωt) + α (1)
The first derivative of the equation (1) is expressed by the following equation (2).
f (t) / dt = ω · cos (ωt) (2)
The second derivative of the equation (1) is expressed by the following equation (3).
f (t) / dt ² = −ω ² · sin (ωt) (3)
The third order differential of the equation (1) is expressed by the following equation (4).
f (t) / dt ³ = −ω ³ · cos (ωt) (4)
Here, in the equation (3), when the second derivative is calculated from the result of the first derivative, that is, when cos (ωt) is differentiated, −sin (ωt) is obtained, and the original waveform data shown in the equation (1) and The polarity changes from “+” to “−”. For this reason, as described above, the waveform differential calculation unit 13 multiplies the obtained second-order differential waveform data by “−1”.

  FIG. 3 is a diagram illustrating a configuration example of a measurement table stored in the storage unit 16 according to the present embodiment. The measurement table is configured for each record from reception time, sensor identification information, waveform data index, second-order differential waveform data index, correlation value, and presence / absence of rust bumps. In the measurement table, the reception time is a time when the vibration measurement unit 12 receives the waveform data from the vibration sensor 11. The sensor identification information is identification information for identifying the vibration sensor 11 that has transmitted the waveform data. The waveform data index is an address of a storage area where the waveform data received in the storage unit 16 is stored.

  The second-order differential waveform data index is an address of a storage area where the second-order differential waveform data is stored in the storage unit 16. The correlation value includes waveform data (0th-order differential waveform data) and second-order differential waveform data (second-order differential waveform data obtained by multiplying “−1” by the waveform intensity (amplitude value) at each time) and It is a numerical value showing the correlation of the waveform intensity for each time (described later). The presence / absence of rust hump is information indicating whether or not there is rust hump on the outer surface of the pipe 101, which is determined from the correlation value indicating the correlation of the waveform intensity at each time between the waveform data and the second-order differential waveform data (described later). ).

  Returning to FIG. 2, the waveform comparison unit 14 sequentially reads out each of the waveform data index and the second-order differential waveform data index in order from the top record of the measurement table. Then, the waveform comparison unit 14 reads out the waveform data and the second-order differential waveform data from the storage unit 16 corresponding to the waveform data index and the second-order differential waveform data index, respectively. The waveform comparison unit 14 extracts the maximum value of the waveform intensity in each of the waveform data and the second-order differential waveform data.

  The waveform comparison unit 14 extracts the maximum value of the waveform intensity from each of the waveform data and the second-order differential waveform data. And the waveform comparison part 14 normalizes the waveform intensity | strength of each waveform data and 2nd-order differential waveform data with the maximum value of each waveform intensity | strength of waveform data and 2nd-order differential waveform data. In addition, the waveform comparison unit 14 calculates a correlation value indicating a correlation between waveform intensities at the same time in each of the normalized waveform data and second-order differential waveform data. Then, the waveform comparison unit 14 writes and stores the calculated correlation value in the measurement table of the storage unit 16 in association with the waveform data and second-order differential waveform data for which the correlation value has been calculated.

  FIG. 4 is a diagram illustrating calculation of a correlation value between waveform data and second-order differential waveform data in the present embodiment. In FIG. 4A, the horizontal axis indicates the time indicating the reception time, and the vertical axis indicates the waveform intensity (the waveform intensity of the vibration sensor signal normalized by the maximum value of the waveform intensity, and thus the maximum value is “1”). ) And the waveform shape of the waveform data (0th-order differential waveform, that is, the original waveform data). The waveform data of FIG. 4A shows the waveform shape when no rust is generated on the outer surface of the pipe 101, that is, the shape of a normal waveform (sound waveform on the outer surface of the pipe 101 without rust hump). Yes.

In FIG. 4B, the horizontal axis indicates the time indicating the reception time, and the vertical axis indicates the waveform intensity (the waveform intensity of the vibration sensor signal normalized by the maximum value of the waveform intensity, and thus the maximum value is “1”). ) And the shape of the waveform of the second-order differential waveform data. When observing the waveform shape of FIG. 4B, in the waveform data shown in FIG. 4A, the change in the waveform shape that cannot be visually recognized is emphasized by differentiation and is slightly visible.
In FIG. 4C, the horizontal axis indicates the waveform intensity at each time of the original waveform signal, and the vertical axis indicates the waveform intensity at each time of the second-order differential waveform. That is, FIG. 4C shows the correlation value of the waveform intensity at the same time in the waveform data and the second-order differential waveform data. In FIG. 4C, the correlation value is 0.95, indicating that the waveform data and the second-order differential waveform data have the same waveform shape.

  FIG. 5 is a diagram illustrating calculation of a correlation value between waveform data and second-order differential waveform data in the present embodiment. In FIG. 5A, the horizontal axis indicates the time indicating the reception time, and the vertical axis indicates the waveform intensity (the waveform intensity of the vibration sensor signal normalized by the maximum value of the waveform intensity, and thus the maximum value is “1”). ) And the waveform shape of the waveform data (0th-order differential waveform, that is, the original waveform data). The waveform data of FIG. 5A shows the shape of a waveform when rust humps are generated on the outer surface of the pipe 101, that is, the shape of an abnormal waveform (the rust hump is the waveform of the overall corrosion of the outer surface of the pipe 101). ing.

In FIG. 5B, the horizontal axis indicates the time indicating the reception time, and the vertical axis indicates the waveform intensity (the waveform intensity of the vibration sensor signal normalized by the maximum value of the waveform intensity, and thus the maximum value is “1”). ) And the waveform of the second-order differential waveform data. When the waveform shape of FIG. 5B is observed, in the waveform data shown in FIG. 5A, the change in the waveform shape that cannot be visually recognized is emphasized by differentiation, and the waveform is more prominent compared to FIG. 4B. The change in shape is visible.
In FIG. 5C, the horizontal axis represents the waveform intensity at each time of the original waveform signal, and the vertical axis represents the waveform intensity at each time of the second-order differential waveform. That is, FIG. 5C shows the correlation value of the waveform intensity at the same time in the waveform data and the second-order differential waveform data, as in FIG. 4C. However, in FIG. 5C, unlike FIG. 4C, the correlation value is 0.59, indicating that the waveform data and the second-order differential waveform data have different waveform shapes.

  In the present embodiment, as described above, when there is a rust hump, a striking wave that is a vibration propagating through the pipe 101, and a waveform generated by the rust hump based on this striking wave (or the striking wave has changed) Are combined when propagating through the heat insulating material 102, and the waveform data in which the striking wave and the newly generated waveform are combined waves are detected. Then, by differentiating the waveform data, the waveform change in the synthesized wave is emphasized, the second-order differential waveform data is obtained as a waveform shape different from the original waveform data, and the original waveform data and the second-order differential waveform data are obtained. And the shape correlation value decreases. In this embodiment, when there is a rust hump described above, it is used as an index for facilitating detection of the presence or absence of a rust hump using the fact that the correlation value between the waveform data and the differential waveform data decreases.

  In the present embodiment, the correlation between the shapes of the zeroth-order differential waveform data (original waveform) and the second-order differential waveform data, that is, the waveform data subjected to even-order differentiation is calculated. However, the correlation value of the waveform shape between the first-order differential waveform data and the third-order differential waveform data, that is, the waveform data subjected to odd-order differentiation may be calculated and used for the determination of the presence or absence of rust. Further, as can be seen from the equation (1), since the original waveform data includes a constant (α) and a DC (direct current) component as a bias, the first-order differential waveform data and the third-order differential waveform data are When the correlation or the correlation between the second-order differential waveform data and the fourth-order differential waveform data is obtained and compared, the constant α can be removed, so that an accurate correlation value can be obtained.

Returning to FIG. 2, the corrosion determination unit 15 sequentially reads out the correlation values sequentially from the top record of the measurement table in the storage unit 16. And the corrosion determination part 15 compares the threshold value preset in the internal memory | storage part with a correlation value. At this time, when the correlation value is less than the threshold value, the corrosion determination unit 15 determines that the pipe 101 has rust (or is highly likely) at the location where the waveform data used for calculating the correlation value is measured. To do. On the other hand, when the correlation value is equal to or greater than the threshold value, the corrosion determination unit 15 determines that there is no rust (or less likely) at the location where the waveform data used to calculate the correlation value is measured in the pipe 101. .
And the corrosion determination part 15 writes the presence or absence of the determined rust hump into the measurement table of the memory | storage part 16 corresponding to the correlation value used for determination, and memorize | stores it.

  The striking control unit 17 controls the strength of striking applied to the pipe 101. For example, even if the flange 201 and the support member 202 are each given a hit with the same strength, the strength of the hit transmitted from the pipe 201 to the pipe 101 is actually different. For this reason, in the memory | storage part 16, the intensity | strength of the hit | damage given with respect to the flange 201 and the intensity | strength of the hit | damage given with respect to the support member 202 are each written beforehand and memorize | stored. The striking control unit 17 reads the striking strength from the storage unit 16, and controls the striking mechanism 18 so that the striking strength that the striking body 18B applies to the flange 201 and the support member 202 is the strength of the striking read. To do.

  The striking mechanism 18 drives the striking body 18 </ b> B under the control of the striking control unit 17, and applies physical striking with a predetermined strength to the flange 201 and the support member 202 by colliding (crashing). In the striking mechanism 18, a solenoid relay or a magnetostrictive vibrator may be used as the striking body 18B. Alternatively, the striking mechanism 18 is not provided, and the worker uses the hammer 201 or the like as the striking body 18B, and the worker strikes the flange 201 or the supporting member 202 to strike the pipe 101. The striking wave may be generated.

Next, the flow of processing for detecting the presence or absence of corrosion (rust humps) on the outer surface of the pipe using the corrosion detection system in the present embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing a flow operation example of processing for detecting the presence or absence of corrosion on the outer surface of the pipe using the corrosion detection system in the present embodiment.
Step S1:
In order to detect the presence or absence of rust humps in the pipe 101, the worker covers a heat insulating material 102 of the pipe 101 at a predetermined position in the pipe 101 that is set (scheduled) to be detected in advance. The vibration sensor 11 is attached to the outer surface 103. For example, the vibration sensor 11 is provided with a magnet. And an operator fixes and attaches the vibration sensor 11 with respect to a sheet metal with this magnet.

Step S2:
After the attachment operation is completed, the worker attaches the striking mechanism 18 to the flange 201 or the support member 202 at a position where the striking body 18B can perform striking. Then, the worker causes the striking body 18B to collide against the flange 201 or the support member 202 by the striking mechanism 18 by the input means (not shown) with respect to the corrosion detection system 1, and the pipe 101 is connected via the flange 201 or the support member 202. Then, control is performed so as to perform the operation of applying the impact.

  Thereby, the hit | damage control part 17 reads the control value corresponding to the intensity | strength of the hit to apply from the memory | storage part 16 by whether the object which applies a hit | damage is the flange 201 or the support member 202. FIG. The striking control unit 17 drives the striking mechanism 18 with a striking strength corresponding to the read control value, so that the striking body 18B strikes the flange 201 or the support member 202 to the flange 201 or the support member 202. Apply impact by hitting. The pipe 101 vibrates due to the impact given through the flange 201 or the support member 202. The generated vibration propagates to the pipe 101 as a hitting wave.

Step S3:
The vibration sensor 11 detects a striking wave propagating through the pipe 101 as a vibration wave through each of the heat insulating material 102 and the sheet metal 103. At this time, the vibration sensor 11 uses the signal wave in the detection period from the time when the detected signal wave exceeds a predetermined intensity until the preset time elapses to the hitting wave used to obtain the correlation value. Acquired as waveform data.
And the vibration sensor 11 transmits the waveform data of the detected hit | damage wave with respect to the corrosion detection apparatus 10 with the identification information which identifies self.
Here, as the vibration sensor 11, a sensor device having a sensor function and a wireless function, for example, a sensor having a configuration of IoT (internet of things) may be used. In this case, the vibration sensor 11 transmits the waveform data of the detected hammering wave together with its own identification information to the corrosion detection device 10 via a communication network including the Internet (including a wireless communication network).

When the vibration sensor 11 is supplied with the identification information and waveform data of the vibration sensor 11, the vibration measurement unit 12 acquires the reception time of receiving them from the internal clock.
Then, the vibration measurement unit 12 writes and stores each of the supplied identification information and waveform data in the measurement table in the storage unit 16 corresponding to the acquired reception time.
In addition, after the writing of data to the measurement table is completed, the vibration measurement unit 12 displays a notification for confirming whether or not to continue the rust hump detection process on a display screen (not shown).

Step S4:
The operator confirms the above notification displayed on the display screen, and whether or not the waveform data has been acquired in all the rust hump detection locations in the planned pipe 101, that is, the processing for all the predetermined detection locations has been completed. Confirm whether or not.
At this time, when confirming that all the processes have been completed, the worker controls the corrosion detection apparatus 10 to start executing the determination process in order to start the determination process for the presence or absence of rust.
On the other hand, when the operator confirms that all the processes have not been completed, in order to cause the process of detecting the waveform data of the hit wave at the remaining other detection locations, the waveform data of the hit wave from step S1 is processed. Repeat the detection process.

Step S5:
For example, the waveform differential calculation unit 13 refers to the measurement table in the storage unit 16 and reads the waveform data of the striking wave in order from the earliest reception time.
Then, the waveform differentiation calculation unit 13 performs second order differentiation on the read waveform data by using the already described equations (1) and (2), and the differential waveform data as a result of the second order differentiation is obtained. Multiply by “−1”. Then, the waveform differential calculation unit 13 sets the multiplication result as the second-order differential waveform data, writes it in the measurement table in the storage unit 16 and stores it in correspondence with the original waveform data before differentiation.
The waveform differential calculation unit 13 sequentially calculates the second-order differential waveform data described above for all the waveform data in the measurement table of the storage unit 16.

Step S6:
For example, the waveform comparison unit 14 refers to the measurement table in the storage unit 16 and, in order of reception time, the waveform data index of the waveform data and the second-order differential waveform data index of the second-order differential waveform data corresponding to this waveform data. Are read as a pair. The waveform comparison unit 14 reads out waveform data from the waveform data index, and reads out second-order differential waveform data from the storage unit 16 from the second-order differential waveform data index.
Then, the waveform comparison unit 14 extracts the maximum waveform intensity (maximum waveform intensity) in the read waveform data, and normalizes the waveform intensity at each time in the read waveform data based on the maximum waveform intensity. Similarly, the waveform comparison unit 14 extracts the maximum waveform intensity in the read second-order differential waveform data, and normalizes the waveform intensity at each time in the read second-order differential waveform data based on this maximum waveform intensity.

Next, as described in FIGS. 4 and 5, the waveform comparison unit 14 correlates the waveform strength correlation values at the same time in the normalized waveform data and second-order differential waveform data, that is, the waveform data and the second-order differential, respectively. The correlation value of the waveform shape with the waveform data is calculated.
Then, the waveform comparison unit 14 causes the calculated correlation value to correspond to the waveform data and second-order differential waveform data for which the correlation value has been calculated, and writes and stores the correlation value in the measurement table of the storage unit 16. The waveform comparison unit 14 sequentially correlates the waveform intensities at the same time in the above-described waveform data and second-order differential waveform data with respect to all combinations of waveform data and second-order differential waveform data in the measurement table of the storage unit 16. The process which calculates is performed.

Step S7:
For example, the corrosion determination unit 15 refers to the measurement table in the storage unit 16 and reads the correlation value for the combination of the waveform data and the second-order differential waveform data corresponding to the waveform data in the order of reception time.
Then, the corrosion determination unit 15 compares the read correlation value with a preset threshold value. At this time, if the correlation value is greater than or equal to the threshold value, the corrosion determination unit 15 determines that no rust has occurred on the outer surface of the pipe 101 at the location where the waveform data has been acquired. On the other hand, when the correlation value is less than the threshold value, the corrosion determination unit 15 has rust bumps on the outer surface of the pipe 101 where the waveform data is acquired (or compared with a case where the correlation value is equal to or greater than the threshold value). And the probability of occurrence of rust humps is high).

  Further, the corrosion determination unit 15 writes and stores the comparison result obtained by comparing the correlation value with the threshold value in the measurement table of the storage unit 16 in association with the correlation value used for the comparison. The waveform comparison unit 14 sequentially compares all the correlation values of the combination in the waveform data and the second-order differential waveform data in the measurement table of the storage unit 16 with the above-described correlation value and the threshold value, thereby generating rust humps. A process for determining the presence or absence of is performed.

After the detection process of the presence or absence of rust humps at the planned location of the pipe 101 is completed, the operator detects the reception time and the vibration sensor 11 determined to have rust humps as a correlation value determination result for the corrosion detection device 10. Control is performed to extract each of the identification information.
As a result, the corrosion determination unit 15 refers to the measurement table of the storage unit 16 and extracts the reception time and the identification information of the vibration sensor 11 in which the term of presence or absence of rust is present. Then, the corrosion determination unit 15 displays the extracted reception time and the identification information of the vibration sensor 11 on the display screen, and notifies the operator of the determination result that there is rust humps.

From the combination of the reception time displayed on the display screen and the identification information of the vibration sensor 11, the operator describes the location of the pipe 101 to which the vibration sensor 11 is attached, for example, the measurement schedule of the detection location in the pipe 101. Specify by referring to the schedule table.
Then, the worker observes the location in the specified pipe 101 in detail with an X-ray detection device or the like, and determines whether or not repair is necessary. Alternatively, the sheet metal 202 and the heat insulating material 201 at the specified locations may be removed, and it may be determined by visual inspection whether repair is necessary.

As described above, according to the present embodiment, the corrosion (rust hump) on the outer surface of the pipe 101 covered with the heat insulating material 102 and the sheet metal 103 is covered with the pipe without being removed from the heat insulating material 102 and the sheet metal 103. The presence or absence of corrosion on the outer surface of 101 can be easily detected.
Further, according to the present embodiment, an X-ray apparatus or the like is used only at a location identified as corroded by simply detecting the presence or absence of corrosion on the outer surface of the pipe 101 while being covered. Detailed confirmation of the necessity of repair can be performed, and the efficiency of confirmation of the necessity of repair can be improved.

In the above-described embodiment, the piping design drawing (two-dimensional coordinate system) in the facility is converted into digital data, and the coordinates of the measurement location are written in the measurement table for the combination of the reception time and the vibration sensor 11. It is also good.
And the corrosion determination part 15 displays the mark which shows corrosion on the coordinate determined as having corrosion in the image of the said design drawing displayed on a display screen, and corrosion generate | occur | produces in any position of piping. It is good also as a structure which can be visually observed on the display screen of the corrosion detection apparatus 10 whether it is doing.

Next, FIG. 7 is a diagram illustrating a configuration example of a pipe management system using the corrosion detection system in the present embodiment described above. The piping management system 20 in FIG. 7 includes a piping management server 21, a corrosion detection system 1, a facility database 22, and a management database 23.
In the facility database 22, image data of a design drawing showing the arrangement (installation) shape of the piping for each predetermined facility that is a management target is written and stored in advance.
In the management database 23, a schedule for detecting the presence or absence of corrosion in the piping of each facility is pre-written and stored in a detection schedule table in which each facility and each piping is described. In the management database 23, a measurement table indicating the detection of the presence / absence of corrosion of the facility and piping that has been detected in the detection schedule table is sent from the corrosion detection system 1, and the facility and piping (for example, the detection date and time) , Identification information such as the facility name of the facility and the coordinate value of the detected part of the piping on the design drawing).

  The management server 21 refers to the detection schedule table in the management database 23, displays the facilities and pipes scheduled for detection on the display screen, and notifies the operator that the facilities and pipes are to be detected. At this time, the management server 21 reads an image of the facility and piping design drawing from the facility database 22 and displays it on the display screen. Thereby, the operator confirms the display screen and detects the presence or absence of corrosion in the notified facility and piping by the corrosion detection system 1. In addition, the management server 21 detects the date and time when the detection table sent from the corrosion detection system 1 and showing the detection of the presence or absence of corrosion of the facility and the pipe where the detection of the presence or absence of corrosion is completed, as described above. In correspondence with the facility and the piping, it is written and stored in the management database 23 as a detection result table.

  Further, the program for realizing the function of the corrosion detection apparatus 10 in FIG. 2 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into the computer system and executed, thereby executing the above-described operation. Using the waveform data of the impact wave propagating through the pipe, a process for detecting the presence or absence of a region where corrosion has occurred on the outer surface of the pipe may be performed. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Corrosion detection system 10 ... Corrosion detection apparatus 11, 11_A, 11_B, 11_C ... Vibration sensor 12 ... Vibration measurement part 13 ... Waveform differential calculation part 14 ... Waveform comparison part 15 ... Corrosion judgment part 16 ... Memory | storage part 17 ... Impact control part DESCRIPTION OF SYMBOLS 18 ... Blowing mechanism 18B ... Impacting body 20 ... Piping management system 21 ... Piping management server 22 ... Facility database 23 ... Management database 101 ... Piping 102 ... Insulation material 103 ... Sheet metal 201 ... Flange 202 ... Support member

Claims (7)

A striking mechanism that applies striking to the piping;
A vibration sensor that detects a striking wave propagating to the pipe by the hit, and is attached to an outer surface of a covering material that covers the pipe;
A waveform differentiation calculation unit for differentiating the waveform data of the hitting wave acquired by the vibration sensor;
Between the even-order differential data of the waveform data calculated by the waveform differential calculation unit, or between the odd-order differential data, a waveform comparison unit that calculates the correlation value of the intensity data of the waveform at the same measurement time,
A corrosion detection system comprising: a corrosion determination unit that determines the presence or absence of corrosion on the outer surface of the pipe based on the correlation value. The vibration sensor is
The waveform of the striking wave transmitted to the pipe is detected as a waveform that changes in response to a change in the state of the outer surface of the pipe at the interface via the interface between the outer surface of the pipe and the covering material. The corrosion detection system according to claim 1. The vibration sensor is
The waveform of a period from when the intensity of the waveform of the hitting wave becomes a predetermined value or more to when the pipe generates resonance of the hitting wave due to the hitting is acquired as the waveform data. The corrosion detection system according to claim 1 or 2. The waveform comparison unit
The correlation value is calculated after normalizing each even-numbered differential data or odd-numbered differential data that uses the correlation value for calculation with the maximum intensity of each amplitude. The corrosion detection system according to claim 3. The vibration sensor is
The corrosion detection system according to any one of claims 1 to 4, wherein the corrosion detection system is a device having a wireless function. A pipe management system using the corrosion detection system according to any one of claims 1 to 5,
A piping management server;
A facility database that stores a blueprint showing the arrangement of piping for each predetermined facility;
A management database storing the detection result of the pipe and the detection schedule of the pipe, and
The piping management system, wherein the piping management server writes and stores in a management database the detection result of the piping performed in response to the design drawing by the corrosion detection system based on the detection schedule. A striking application process in which a striking mechanism applies striking to the pipe,
The vibration sensor detects a striking wave propagating to the pipe by the striking, a striking wave detection process attached to the outer surface of the covering material covering the pipe,
A waveform differential operation unit, a waveform differential operation process for differentiating the waveform data of the hitting wave acquired by the vibration sensor;
A waveform comparison process in which the waveform comparison unit calculates the correlation value of the intensity data of the waveform at the same measurement time between the even-order differential data of the waveform data calculated by the waveform differential calculation unit or between the odd-order differential data,
A corrosion detection method, wherein the corrosion determination unit includes a corrosion determination process for determining the presence or absence of corrosion on the outer surface of the pipe based on the correlation value.

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