WO2018043775A1

WO2018043775A1 - Corrosion under insulation diagnosis-based wave mode selection device and operating method therefor

Info

Publication number: WO2018043775A1
Application number: PCT/KR2016/009847
Authority: WO
Inventors: 이동훈; 조현준; 허윤실; 김병덕; 조영도; 이연재
Original assignee: 한국가스안전공사
Priority date: 2016-09-01
Filing date: 2016-09-02
Publication date: 2018-03-08

Abstract

The present invention relates to a wave mode selection device and an operating method therefor, the device enabling effective diagnosis of corrosion under insulation, which occurs in a pipe protected with an insulation material encompassing an outer wall of the pipe, by selecting a wave mode, in which an energy attenuation amount of an induced ultrasound can be minimized, in consideration of an energy attenuation characteristic in the pipe.

Description

Wave mode selection device based on thermal load corrosion diagnosis and its operation method

The present invention is a method for selecting an induced ultrasonic wave mode that can effectively diagnose the insulation under corrosion (CUI, Corrosion Under Insulation) generated in the pipe in consideration of the energy attenuation characteristics in the pipe is protected by the outer wall wrapped with a heat insulating material It is about.

Guided ultrasound is a wave propagating in the longitudinal direction along the geometrical shape of the structure, the longitudinal wave and the transverse wave propagating in the longitudinal direction along the geometrical structure of the structure is formed by a number of reflections and overlapping between the walls of the structure.

This is the development of the plate wave technology applied to the plate, it can be understood as a form of ultrasonic vibration propagating in the longitudinal (axial) direction along the geometry of the cylindrical structure, such as piping.

The guided ultrasonic waves may be used to diagnose the integrity of the pipe through a method of analyzing the size, shape, and characteristics of the wave reflected from the pipe defect by injecting ultrasonic waves at a predetermined angle into the pipe.

On the other hand, due to the constraints of the pipe, the outer wall of the pipe is generally wrapped and protected with various insulating materials, and in the case of these pipes, it is essential to diagnose the Corrosion Under Insulation (CUI) to maintain soundness.

However, the thermal insulation material surrounding the outer wall of the pipe induces the energy attenuation characteristics in the pipe to attenuate the energy of the guided ultrasonic waves traveling along the pipe. Disturb.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide thermal insulation corrosion generated in pipes in consideration of energy attenuation characteristics in pipes in which outer walls are covered with a heat insulating material and protected. In order to effectively diagnose under insulation, it is to select the wave mode of the induced ultrasonic wave.

According to one or more embodiments of the present invention, a wave mode selection apparatus includes a frequency and a phase for each of a plurality of wave modes capable of generating an induced ultrasonic wave in a pipe having a fixed thickness between an inner wall and an outer wall. A confirmation unit for confirming a waveform structure illustrated by selecting a combination of frequency and phase velocity based on a dispersion curve representing a functional relationship between velocity; An analysis unit analyzing an energy displacement distribution of a propagation component which each of the plurality of wave modes has in the pipe based on the waveform structure; And selecting a specific wave mode capable of diagnosing Corrosion Under Insulation (CUI) among the plurality of wave modes according to the energy attenuation characteristics of the pipe based on the energy displacement distribution of the propagation component. Characterized in that it comprises a selection unit.

More specifically, the energy displacement distribution of the propagation component is the energy displacement distribution of the axial propagation component and the circumferential propagation component in each of the outer wall region, the inner wall region, and the center region between the outer wall region and the inner wall region of the pipe. And at least one of the energy displacement distribution of and the energy displacement distribution of the radial propagation component.

More specifically, the energy attenuation characteristic of the pipe, the energy attenuation in at least one of the outer wall region and the inner wall region includes an energy attenuation characteristic greater than the threshold value compared to the energy attenuation in the central region of the pipe. It features.

More specifically, the specific wave mode is characterized in that the axial propagation component comprises a wave mode in which variation in energy magnitude seen in the outer wall region, the inner wall region, and the central region is within a threshold.

More specifically, the specific wave mode is characterized in that it comprises a wave mode in which the energy magnitude of the axial propagation component is greater than the energy magnitude of the circumferential propagation component and the radial propagation component.

More specifically, the specific wave mode is characterized in that it comprises a wave mode in which the energy magnitude of the axial propagation component is seen in the central region is greater than the energy magnitude seen in the outer wall region and the inner wall region.

Operation method of the wave mode selection device according to an embodiment of the present invention for achieving the above object, for each of a plurality of wave modes that can generate an ultrasonic wave in the pipe having a fixed thickness between the inner wall and the outer wall, Identifying a waveform structure illustrated by selecting a combination of frequency and phase velocity based on a dispersion curve representing a function relationship between frequency and phase velocity; An analysis step of analyzing an energy displacement distribution of a propagation component which each of the plurality of wave modes has in the pipe based on the waveform structure; And selecting a specific wave mode capable of diagnosing Corrosion Under Insulation (CUI) among the plurality of wave modes according to the energy attenuation characteristics of the pipe based on the energy displacement distribution of the propagation component. Characterized in that it comprises a selection step.

Accordingly, in the wave mode selection apparatus and the method of operation of the present invention, in consideration of the energy attenuation characteristics in the pipe that is covered with the outer wall is protected by the heat insulating material by selecting the wave mode that can minimize the amount of energy attenuation of the ultrasonic wave generated in the pipe Enables effective diagnosis of insulated corrosion.

1 is a view for explaining a wave mode selection environment of the ultrasonic wave according to an embodiment of the present invention.

2 is a view for explaining the configuration of the wave mode selection apparatus according to an embodiment of the present invention.

3 to 8 are exemplary diagrams for explaining the analysis of the energy distribution of the radio wave component according to an embodiment of the present invention.

9 is a flow chart for explaining the operation flow in the wave mode selection apparatus according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

1 illustrates a wave mode selection environment of an ultrasonic wave according to an embodiment of the present invention.

As shown in Figure 1, the wave mode selection environment of the induced ultrasonic wave according to an embodiment of the present invention generates the induced ultrasonic waves through the transducers (2, 3) installed on the outer circumferential surface of the pipe (1) and at the same time the pipe (1) Diagnosis apparatus 100 for diagnosing the integrity of the pipe 1 by receiving the guided ultrasonic waves through the (), and wave mode selection device for selecting the wave mode of the guided ultrasonic wave used for diagnosis prior to the soundness diagnosis of the pipe (1) It may have a configuration that includes (200).

Here, the pipe (1) refers to a fluid transport path used in industrial equipment, such as petrochemical plants, which can be understood as an insulating pipe that is protected by the outer wall of the pipe is protected by a variety of heat insulating material due to the constraints of the pipe.

In this way, the heat insulating material that audits the outer wall of the pipe 1 attenuates the energy of the induced ultrasonic waves traveling along the pipe. If the fluid is transported through the pipe 1, the outer wall and the inner wall of the pipe 1 are also reduced. Similarly, energy attenuation of induced ultrasonic waves due to fluid is generated.

As a result, in the case of the pipe 1 according to the embodiment of the present invention, the energy of the induced ultrasonic wave is attenuated in the inner wall region as well as the outer wall region.

Of course, in the center region between the outer wall region and the inner wall region of the pipe 1, energy attenuation of the induced ultrasonic waves is expected due to the media characteristics of the pipe 1, but this is the amount of energy attenuation generated in the outer wall region and the inner wall region of the pipe 1. It will be inferior to.

For reference, in one embodiment of the present invention, in order to consider the energy attenuation phenomenon of the induced ultrasonic waves, which may be generated in the center region of the pipe 1 as described above, the energy attenuation characteristics of the pipe 1 may be selected from the outer wall region and the inner wall region. The energy decay amount in at least one region will be defined as being greater than or equal to the threshold compared to the energy decay amount in the central region.

Here, of course, the threshold associated with the amount of energy attenuation may be defined as various values depending on the setting.

In conclusion, the diagnostic apparatus 100 according to an embodiment of the present invention diagnoses Corrosion Under Insulation (CUI) generated in the pipe 1 through guided ultrasonic waves, and thus the pipe 1 has The energy attenuation characteristic significantly reduces the energy of the induced ultrasonic waves via the pipe 1, making it impossible to diagnose normal protective load corrosion.

Therefore, in one embodiment of the present invention, in consideration of the energy attenuation characteristics of the pipe (1), to propose a wave mode selection method of the induced ultrasonic waves that can effectively diagnose the thermal insulation corrosion generated in the pipe (1), In the following will be described in detail the configuration of the wave mode selection apparatus 200 for this purpose.

2 shows a schematic configuration of a wave mode selection device 200 according to an embodiment of the present invention.

As shown in Figure 2, the wave mode selection apparatus 200 according to an embodiment of the present invention is a confirmation unit 210 for confirming the wave structure of the wave mode of the induced ultrasonic wave, pipes for each wave mode of the induced ultrasonic wave (1) Analysis unit 220 for analyzing the energy displacement distribution of the propagation component to have within), and selector 230 for selecting a specific wave mode for diagnosing the thermal load corrosion based on the analysis results of the energy displacement distribution of the radio wave component It may have a configuration that includes).

The whole or at least part of the configuration of the wave mode selection apparatus 200 including the identification unit 210, the analysis unit 220, and the selection unit 230 may be implemented in the form of a hardware module or in the form of a software module. Can be.

Here, the software module may be understood as an instruction executed by a processor that processes an operation in the wave mode selection apparatus 200, and the instruction may have a form stored in the wave mode selection apparatus 200.

As a result, the wave mode selection apparatus 200 according to an embodiment of the present invention can effectively diagnose the thermal load corrosion generated in the pipe 1 in consideration of the energy attenuation characteristics of the pipe 1 through the above configuration. The specific wave mode of the induced ultrasonic wave may be selected. Hereinafter, the functions of the respective components in the wave mode selection device 200 will be described in detail.

For reference, the wave mode of the induced ultrasonic wave uses two subscripts 'circumferential order' and 'mode number' when the traveling direction of the induced ultrasonic wave is the longitudinal direction of the pipe (1).

If the 'circumferential order' is '0', it is symmetrical about the axis of the pipe (1). If it is not '0', it is not symmetrical about the axis of the pipe (1).

Therefore, when 'circumferential order' is '0', it indicates axisymmetric modes, which are again referred to as longitudinal mode (hereinafter referred to as 'L mode') and Torsional mode (hereinafter referred to as 'T mode'). Waves are distinguished according to their oscillation in the wall (between the outer and inner surfaces) of the pipe (1).

In the L mode, when the oscillating component of the wave exists only in the length (axial) direction and the radial direction of the pipe (1), it is represented as 'L (0, n)'. If present, it is represented by 'T (0, n)'.

If the 'circumferential order' is '1,2,3, ..., M' instead of '0', it indicates non-axisymmetric modes, which is called Flexural mode (hereinafter referred to as 'F mode'). It is referred to as 'F (0, n)'.

In the case of the F mode, the vibration component of the wave exists in all three directions (radius, circumference, axis) in the wall of the pipe (1).

L and T modes have an infinite number of modes in '0' and 'circumferential order' in 'circumferential order' even if 'circumferential order' is '1,2,3, ..., M'. Can have an infinite number of F modes.

Meanwhile, in the following description, for convenience of explanation, the L mode symmetrical with respect to the axial direction will be described as an example, and the wave mode selection device (assuming that the thickness between the inner wall and the outer wall of the pipe 1 is fixed) 200) The description of each component will be continued.

The identification unit 210 processes a function of confirming a waveform structure for each wave mode of the induced ultrasonic wave.

More specifically, the identification unit 210 confirms the waveform structure illustrated through the selection of frequency and phase velocity combinations based on the dispersion curves of each of the plurality of wave modes capable of generating guided ultrasonic waves in the pipe 1. do.

Here, the dispersion curve represents a functional relationship between the frequency, the thickness of the pipe 1, and the phase speed. In one embodiment of the present invention, since the thickness of the pipe 1 is assumed to be fixed, the dispersion relationship between the frequency and the phase speed is assumed. Can be understood as.

The guided ultrasonic waves have dispersibility in which the propagation speed varies depending on the shape of the pipe 1 and the excitation frequency, and the phase velocity, which is the theoretical propagation speed of the guided ultrasonic waves, is a condition that overlaps each wave from the wave equation. It can be calculated by finding the solution.

As described above, the dispersion curve showing the functional relationship between the phase velocity and the frequency of the induced ultrasonic wave having a dispersibility is, for example, the Korea Gas Safety Corporation induced ultrasonic dispersion diagram program [KGS-GWDC, Registration No .: C-2016-010196]. It can be derived through, but is not limited to this can include all programs that can represent the functional relationship between the phase speed and frequency of the ultrasonic wave.

Further, the waveform structure can be illustrated as a result of analyzing the energy displacement distribution of the propagation component in each of the outer wall region, the inner wall region, and the central region between the outer wall region and the inner wall region of the pipe 1 as a vector component.

Here, the energy displacement distribution of the propagation component includes the energy displacement distribution U _Z of the axial propagation component in each of the outer wall region, the inner wall region, and the center region of the pipe 1, and the energy displacement distribution U _θ of the circumferential propagation component. ), And the energy displacement distribution U _r of the radial propagation component.

Such a waveform structure can be illustrated through, for example, 'Korea Gas Safety Corporation Induction Ultrasonic Waveform Structure Program [KGS-GWWS, Registration No .: C-2016-010197]', but is not limited thereto. Of course, any program that can illustrate the waveform structure by selecting a combination of frequency and phase velocity can be included.

In this regard, FIGS. 3 to 8 illustrate through the selection of a dispersion curve (a) showing a function relationship of phase velocity and frequency for each mode in the L mode and a combination of frequency and phase velocity in the dispersion curve. Examples of the waveform structure (b) are shown.

For reference, in the dispersion curves a shown in FIGS. 3 to 8, the horizontal axis fd represents the product of the frequency and the thickness of the pipe 1, and the vertical axis represents the phase velocity.

In addition, in the waveform structure (b) illustrated in FIGS. 3 to 8, the horizontal axis represents a magnitude of energy (amplitude) of the propagation component, and the vertical axis represents a thickness of the pipe 1. In order, the range of the inner surface region, the center region, and the outer surface region is sequentially indicated.

The analyzer 220 processes a function of analyzing the energy displacement distribution of the radio wave component for each wave mode.

More specifically, when the analysis unit 220 confirms the waveform structure illustrated through the selection of the frequency and phase velocity combination based on the dispersion curve for each wave mode, the outer wall region of the pipe 1 from the waveform structure, Analyze the energy displacement distribution of the axial propagation component U _Z , the energy displacement distribution of the circumferential propagation component U _θ , and the energy displacement distribution of the radial propagation component U _r in the inner wall region and the central region, respectively. Done.

As described above, the analysis result of the energy displacement distribution of the propagation component made for each wave mode will be described in detail with reference to FIGS. 3 to 8.

3 shows a waveform structure illustrated in the case where a combination of frequency '0.1 MHz' and phase velocity '5.391 mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, in the energy displacement distribution of the propagation component, most of the energy propagated in the pipe 1 is concentrated in the axial propagation component U _Z , and the axial propagation component in each of the outer wall region, the inner wall region, and the center region. It can be analyzed that the energy displacement distribution of (U _Z ) is constant.

4 shows a waveform structure illustrated in the case where a combination of frequency '0.2 MHz' and phase velocity '5.227 mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, the energy displacement distribution of the propagation component is concentrated in the axial propagation component U _Z most of the energy propagated in the pipe 1, and the energy displacement distribution of the axial propagation component U _Z is the outer wall region, It can be analyzed that there is a slight gradient (about 20%) between the inner wall regions.

5 shows a waveform structure illustrated in the case where a combination of frequency '0.25 MHz' and phase velocity '5.139 mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, the energy displacement distribution of the propagation component is larger in the energy propagation of the radial propagation component U _r in the inner surface of the pipe 1 than in the previous case, and the energy displacement distribution of the axial propagation component U _Z is the outer wall region, It can be analyzed that there is a gradient (about 40%) between the inner wall regions, which can be understood as the region where the dispersibility of the propagation component begins.

FIG. 6 shows a waveform structure illustrated in the case where a combination of frequency '0.3 MHz' and phase velocity '4.829 mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, the energy displacement distribution of the propagation component can be analyzed that the energy displacement distribution of the axial propagation component U _Z is small in the outer wall region and the inner wall region and concentrated in the central region. This can be understood as a difficult area.

7 shows a waveform structure illustrated in the case where a combination of frequency '0.4 MHz' and phase velocity '3.567 mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, the energy displacement distribution of the propagation component may be analyzed as the energy displacement distribution of the axial propagation component U _Z is small in the outer wall region and the inner wall region and concentrated in the center region, as in the analysis result of FIG. 6. As the dispersion of components is deepened, it can be understood as an area where signal analysis is difficult.

FIG. 8 shows a waveform structure illustrated in the case where a combination of frequency '0.5MHz' and phase velocity '3.193mm / μs' is selected from the dispersion curve a of the wave mode 'L [0,2]' Giving.

At this time, the energy displacement distribution of the propagation component is analyzed that both the axial propagation component U _Z and the radial propagation component U _r are concentrated in the outer surface region of the pipe 1, which is defective in the inner surface region. In this case, it can be understood that the detection is difficult.

The selecting unit 230 processes a function of selecting a wave mode for diagnosing the thermal insulation corrosion.

More specifically, the selector 230 considers the energy attenuation characteristics of the pipe 1 based on the analysis result when the analysis of the energy displacement distribution of the propagation component that each wave mode has in the pipe 1 is completed. By selecting the wave mode to diagnose the thermal load corrosion.

Here, selecting the wave mode may be understood not only to select the wave mode itself but also to select a combination of frequency and phase velocity in the selected wave mode.

For reference, the energy attenuation characteristic of the pipe 1 has been previously defined as the amount of energy attenuation in at least one of the outer wall region and the inner wall region is larger than a threshold value compared to the energy reduction amount in the central region.

At this time, the selector 230 selects a wave mode for diagnosing the thermal load corrosion as a wave mode for which the energy magnitude of the axial propagation component is larger than the circumferential propagation component and the radial propagation component.

Thus, selecting the wave mode in which the energy magnitude of the axial propagation component is larger than the circumferential propagation component and the radial propagation component is the axis (length) of the pipe 1 in the case of the diagnosis of the thermal insulation load corrosion on the pipe 1. This is to check the distance in the direction of).

That is, in order to enable such a remote inspection under the limited energy generating the induced ultrasonic waves, a sufficient inspection distance can be secured only when the energy is concentrated in the axial propagation component and the axial propagation component rather than the radial propagation component.

In addition, the selector 230 selects a wave mode in which the axial propagation component has a variation in the magnitude of energy seen in the outer wall region, the inner wall region, and the center region within a threshold as a wave mode for diagnosing the thermal insulation corrosion.

Here, it can be understood that the axial propagation component has a small variation in energy magnitudes seen in the outer wall region, the inner wall region, and the central region within a threshold value, and the dispersibility of the axial propagation component is small. Of course, can be defined as a variety of values depending on the setting.

If the axial propagation component has a difference in the magnitude of energy seen in the outer wall region, the inner wall region, and the central region exceeding the threshold, that is, when the dispersion of the axial propagation component is large, the signal reception time for the axial propagation component is It becomes longer and is not suitable for the diagnosis of thermal load corrosion.

In addition, the selector 230 selects a wave mode in which an axial propagation component has an energy magnitude larger than that seen in the center wall region and an inner wall region as a wave mode for diagnosing the thermal insulation corrosion.

As such, selecting a wave mode in which the axial propagation component is larger than the energy magnitude seen in the center region and the inner wall region is such that the amount of energy attenuation in at least one of the outer wall region and the inner wall region is changed in the center region. This is to consider the energy attenuation characteristics of the pipe (1) larger than the threshold value compared to the amount of energy attenuation.

That is, by selecting the wave mode in which the energy distribution of the axial propagation component is concentrated in the center region rather than the outer wall region and the inner wall region, the amount of energy lost by the energy attenuation characteristic of the piping 1 can be minimized. It can be understood that minimizing the amount of energy lost by the energy attenuation characteristic of N) can be remotely diagnosed and the accuracy of the diagnosis can be improved.

As a result, the selector 230 has an energy magnitude of the axial propagation component larger than the circumferential propagation component and the radial propagation component, and the selection unit 230 has an axial propagation component having an outer wall region, an inner wall region, and The wave mode for diagnosing thermal load corrosion is selected as the wave mode where the deviation of the energy magnitude seen in the central region is within the threshold and the energy magnitude in the axial propagation component is greater than the energy magnitude seen in the outer wall region and the inner wall region. By considering the energy attenuation characteristics of the pipe (1) through the way, it is possible to effectively diagnose the thermal insulation corrosion.

For reference, the selection result of the selection unit 230 is, for example, the frequency '0.1MHz' from the dispersion curve a of the wave mode described with reference to FIG. 3 or 4, that is, 'L [0,2]'. And a combination of phase velocity '5.391mm / μs' or a combination of frequency '0.2MHz' and phase velocity '5.227mm / μs' from the dispersion curve (a) of 'L [0,2]'. Can be.

As described above, according to the configuration of the wave mode selection apparatus 200 according to an embodiment of the present invention, the energy attenuation amount of the induced ultrasonic wave is minimized in consideration of the energy attenuation characteristic of the pipe that is protected by the outer wall of the insulation. By selecting the appropriate wave mode, it can be seen that the effective diagnosis of the thermal load corrosion occurring in the pipe is possible.

After the configuration of the wave mode selection device 200 has been described above, the operation flow in the wave mode selection device 200 according to an embodiment of the present invention will be described with reference to FIG. 9.

First, the verification unit 210 derives the dispersion curves of each of the plurality of wave modes capable of generating the induced ultrasonic waves in the pipe 1 according to the steps 'S110' to 'S130' and based on the derived dispersion curve The waveform structure shown is identified through the selection of frequency and phase velocity combinations.

At this time, the dispersion curve showing the functional relationship between the phase velocity and the frequency of the induced ultrasonic waves, for example, can be derived through the 'Korea Gas Safety Corporation guided ultrasonic dispersion diagram program [KGS-GWDC, Registration No .: C-2016-010196]'. Can be.

In addition, the waveform structure can be illustrated, for example, through the 'Korea Gas Safety Corporation Induction Ultrasonic Waveform Structure Program [KGS-GWWS, Registration No .: C-2016-010197]'.

Then, when the analysis unit 220 confirms the illustrated waveform structure through the selection of the frequency and phase velocity combinations based on the dispersion curves for the wave modes, the pipe 1 may be removed from the corresponding waveform structure according to step S140. The energy displacement distribution of the axial propagation component U _Z , the energy displacement distribution of the circumferential propagation component U _θ , and the energy displacement of the radial propagation component U _r in the outer wall region, the inner wall region, and the central region, respectively. Analyze the distribution.

After that, when the analysis of the energy displacement distribution of the propagation component that each of the wave modes has in the pipe 1 is completed, the selector 230 performs the energy of the pipe 1 based on the analysis result according to step S150. Considering the damping characteristics, select the wave mode to diagnose the thermal load corrosion.

Here, it can be understood that the dispersion of the axial propagation component is small that the variation in the magnitude of energy seen in the outer wall region, the inner wall region, and the central region is within a threshold.

As described above, the amount of energy attenuation of the induced ultrasonic wave is minimized in consideration of the energy attenuation characteristic of the pipe in which the outer wall is covered with a heat insulating material in the operation flow in the wave mode selection apparatus 200 according to the embodiment of the present invention. By selecting the wave mode that can be used, it can be seen that the effective diagnosis of the thermal load corrosion occurring in the pipe is possible.

Meanwhile, the functional operations and implementations of the subject matter described in this specification may be implemented in digital electronic circuitry, computer software, firmware or hardware including the structures and structural equivalents disclosed herein, or one or more of them. It can be implemented in combination. Implementations of the subject matter described herein are one or more computer program products, ie one or more modules pertaining to computer program instructions encoded on a program storage medium of tangible type for controlling or by the operation of a processing system. Can be implemented.

The computer readable medium may be a machine readable storage device, a machine readable storage substrate, a memory device, a composition of materials affecting a machine readable propagated signal, or a combination of one or more thereof.

As used herein, the term "system" or "device" encompasses all the instruments, devices, and machines for processing data, including, for example, programmable processors, computers, or multiple processors or computers. The processing system may include, in addition to hardware, code that forms an execution environment for a computer program on demand, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more thereof. .

Computer programs (also known as programs, software, software applications, scripts, or code) may be written in any form of programming language, including compiled or interpreted languages, or a priori or procedural languages. It can be deployed in any form, including components, subroutines, or other units suitable for use in a computer environment. Computer programs do not necessarily correspond to files in the file system. A program may be in a single file provided to the requested program, in multiple interactive files (eg, a file that stores one or more modules, subprograms, or parts of code), or part of a file that holds other programs or data. (Eg, one or more scripts stored in a markup language document). The computer program may be deployed to run on a single computer or on multiple computers located at one site or distributed across multiple sites and interconnected by a communication network.

Computer-readable media suitable for storing computer program instructions and data, on the other hand, include, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices, such as magnetic disks such as internal hard disks or external disks, magneto-optical disks, and CDs. It may include all types of nonvolatile memory, media and memory devices, including -ROM and DVD-ROM disks. The processor and memory can be supplemented by or integrated with special purpose logic circuitry.

Implementations of the subject matter described herein may include, for example, a backend component such as a data server, or include a middleware component such as, for example, an application server, or a web browser or graphical user, for example, where a user may interact with the implementation of the subject matter described herein. It may be implemented in a computing system that includes a front end component, such as a client computer with an interface, or any combination of one or more of such back end, middleware or front end components. The components of the system may be interconnected by any form or medium of digital data communication such as, for example, a communication network.

Although the specification includes numerous specific implementation details, these should not be construed as limiting to any invention or the scope of the claims, but rather as a description of features that may be specific to a particular embodiment of a particular invention. It must be understood. Likewise, certain features described herein in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable subcombination. Furthermore, while the features may operate in a particular combination and may be initially depicted as so claimed, one or more features from the claimed combination may in some cases be excluded from the combination, the claimed combination being a subcombination Or a combination of subcombinations.

In addition, although the drawings depict operations in a particular order, it is to be understood that such operations must be performed in the specific order or sequential order shown in order to obtain desirable results or that all illustrated acts must be performed. Can not be done. In certain cases, multitasking and parallel processing may be advantageous. Moreover, the separation of the various system components of the above-described embodiments should not be understood as requiring such separation in all embodiments, and the described program components and systems will generally be integrated together into a single software product or packaged into multiple software products. Should understand that

As such, the specification is not intended to limit the invention to the specific terms presented. Thus, while the present invention has been described in detail with reference to the above examples, those skilled in the art can make modifications, changes, and variations to the examples without departing from the scope of the invention. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Claims

For each of the multiple wave modes that can generate guided ultrasonic waves in a pipe with a fixed thickness between the inner wall and the outer wall, the selection of frequency and phase velocity combinations is based on a scatter plot that represents the functional relationship between frequency and phase velocity. Confirmation unit for confirming the waveform structure illustrated through;

An analysis unit analyzing an energy displacement distribution of a propagation component which each of the plurality of wave modes has in the pipe based on the waveform structure; And

Selecting a specific wave mode for diagnosing Corrosion Under Insulation (CUI) among the plurality of wave modes according to the energy attenuation characteristics of the pipe based on the energy displacement distribution of the propagation component Wave mode selection device comprising a selection unit.
The method of claim 1,

The energy displacement distribution of the propagation component is

The energy displacement distribution of the axial propagation component, the energy displacement distribution of the circumferential propagation component, and the energy displacement of the radial propagation component in each of the outer wall region, the inner wall region, and the center region between the outer wall region and the inner wall region of the pipe. Wave mode selection device comprising at least one of the distribution.
The method of claim 2,

The energy decay characteristics of the pipe,

And an energy attenuation characteristic in which at least one of the outer wall region and the inner wall region has an energy attenuation characteristic that is greater than or equal to a threshold amount of energy in the central region of the pipe.
The method of claim 3, wherein

The specific wave mode,

And a wave mode in which the energy magnitude of the axial propagation component is greater than the energy magnitude of the circumferential propagation component and the radial propagation component.
The method of claim 3, wherein

The specific wave mode,

And the wave mode in which the axial propagation component includes a wave mode in which variation in energy magnitude seen in the outer wall region, the inner wall region, and the central region is within a threshold.
The method of claim 3, wherein

The specific wave mode,

And a wave mode in which the axial propagation component has an energy magnitude seen in the center region greater than an energy magnitude seen in the outer wall region and the inner wall region.
For each of the multiple wave modes that can generate guided ultrasonic waves in a pipe with a fixed thickness between the inner wall and the outer wall, the selection of frequency and phase velocity combinations is based on a scatter plot that represents the functional relationship between frequency and phase velocity. Confirming the waveform structure illustrated through;

An analysis step of analyzing an energy displacement distribution of a propagation component which each of the plurality of wave modes has in the pipe based on the waveform structure; And

Selecting a specific wave mode for diagnosing Corrosion Under Insulation (CUI) among the plurality of wave modes according to the energy attenuation characteristics of the pipe based on the energy displacement distribution of the propagation component A method of operating a wave mode selection device comprising a step of selecting.