KR102747423B1 - System for detect leaks based on density distribution of current for anticorrosion - Google Patents

Abstract

The present invention discloses a leak detection system based on a current density distribution.
According to one embodiment of the present invention, the present invention comprises: a rectifier which applies different frequencies of harmonic waves by AC power and low frequencies by DC power between a metal structure buried in the ground and an insoluble anode, so that a mode current flows from the insoluble anode to the metal structure; and a measuring module which compares the magnitudes of potentials of a reference electrode buried in the ground and the metal structure, and measures a corresponding mode current density distribution according to a measuring position on the metal structure, wherein the measuring module detects the harmonic waves applied from the AC power of the rectifier and the fundamental wave of the harmonic waves, and measures the potential value by the magnitudes and phase differences of the harmonic waves and the fundamental wave.

Description

{SYSTEM FOR DETECT LEAKS BASED ON DENSITY DISTRIBUTION OF CURRENT FOR ANTICORROSION}

The present invention relates to a leak detection system based on a current density distribution. More specifically, the present invention relates to a technology capable of detecting a leak (e.g., a water leak) by measuring a current density distribution in a metal structure (e.g., a water pipe) and detecting a corrosion location based on the measured current density distribution.

In general, metal structures (metal pipes) buried underground, such as water pipes, gas pipes, and oil pipelines, can corrode depending on the internal and external environments. If corrosion progresses in metal pipes for a long time, cracks can occur, causing problems such as leakage of substances transported in the metal pipes. For example, if water pipes corrode, water leakage can occur, causing tap water to be lost to the outside. Conversely, foreign substances can enter from the outside, causing tap water to be contaminated.

Corrosion refers to a phenomenon in which a metal releases energy to the outside and changes to a state with a relatively low energy potential, thereby creating or separating compounds and causing damage. Various technologies have been developed to prevent or detect corrosion of metal pipes.

First, as a representative method for preventing corrosion of metal pipes, electrical protection technology has been utilized. The electrical protection method is a method for preventing corrosion of metal by artificially supplying electrons to prevent cationization in order to prevent the phenomenon of metal pipes being cationized and corroded by chemical reaction, and includes a sacrificial anode method that utilizes the potential difference between dissimilar metals and is used in cases where it is difficult to use a separate external power source, and an external power source method that is equipped with a rectifier and can control the protection current.

Next, as a representative method for detecting leaks in metal pipes, a method has been utilized to detect leaks in small-diameter, shallow-burrowed metal pipes using tools such as a sounding board. In addition, a method has been utilized to detect leaked moisture by detecting sound waves generated when a leak occurs or by installing moisture detection sensors inside and outside the metal pipe.

However, in the case of the method using a sounding board, since it ultimately relies on human hearing, it is difficult to detect the exact location of the leak because it can only be detected when a certain amount of leakage occurs. In addition, in the case of the method using a moisture sensor, since the moisture detection area is limited, a large number of sensors must be installed according to the length of the metal pipe, which significantly increases the installation cost and complicates the wiring connecting each sensor.

Therefore, there is a need to develop a new concept of leak detection system that can efficiently detect the location of corrosion in metal structures (e.g., water pipes) and accurately detect the location of leaks.

Patent Registration No. 10-1739562 (Registration Date: 2017.05.18.)

Accordingly, the present invention is intended to solve various problems of the prior art as described above, and provides a method for measuring the distribution of the current density in a metal structure (e.g., a water pipe) by applying different frequencies of harmonic waves by an AC power source (e.g., a high-frequency power source) and low frequencies by a DC power source.

In addition, the present invention has another purpose of being able to detect the location of corrosion occurrence based on the current density distribution value that changes when corrosion occurs.

In addition, the present invention has another purpose of detecting the harmonic waves applied from an AC power source and the fundamental wave of the harmonic waves, and determining the degree of corrosion (corrosion state) based on the potential value by the magnitude and phase difference, thereby detecting leakage (e.g., water leakage) of a metal structure.

The above object of the present invention is achieved by a leak detection system including: a rectifier which applies different frequencies of harmonic waves by an AC power supply and low frequencies by a DC power supply between a metal structure buried in the ground and an insoluble anode, so that a fault current flows from the insoluble anode to the metal structure; and a measuring module which compares the magnitudes of potentials of a reference electrode buried in the ground and the metal structure, and measures the corresponding fault current density distribution according to a measuring position on the metal structure, wherein the measuring module detects the harmonic waves applied from the AC power of the rectifier and the fundamental wave of the harmonic waves, and measures the potential value by the magnitude and phase difference of the harmonic waves and the fundamental wave.

At this time, based on the above-mentioned method current density distribution, a corrosion location is detected among the above-mentioned measurement locations of the metal structure, and based on the above-mentioned potential value, a management terminal device may be further included to determine the degree of corrosion at the above-mentioned corrosion location, thereby detecting a leakage of liquid or gas transported inside the metal structure.

In addition, the rectifier controls the mode current by the low frequency and controls the density distribution of the mode current by the harmonic, and the harmonic may be the third harmonic of the fundamental wave.

In addition, the above measurement module can be configured to measure the ground resistance Ri, which is a parameter through harmonic input applied from the high-frequency power source, which is the AC power source, and the polarization potential layer resistance Rd and potential layer Cd, which are parameters by the DC power source.

Additionally, the rectifier and the measuring module can be arranged at regular intervals on the metal structure.

In addition, the present invention is also achieved by other systems, devices and control methods for implementing the present invention.

According to the present invention, there is an effect of being able to measure the current density distribution in a metal structure (e.g., a water pipe) by applying different frequencies of harmonic waves by an AC power source (e.g., a high-frequency power source) and low frequencies by a DC power source.

In addition, according to the present invention, there is an effect of being able to detect the location of corrosion occurrence based on the current density distribution value that changes when corrosion occurs.

In addition, according to the present invention, it is expected that the harmonic waves applied from an AC power source and the fundamental wave of the harmonic waves can be detected, and the corrosion degree (corrosion state) can be determined based on the potential value by the size and phase difference, thereby detecting leakage (e.g., water leakage) of a metal structure.

FIG. 1 is a drawing showing the overall configuration of a leak detection system based on a current density distribution according to one embodiment of the present invention.
FIG. 2 is a drawing showing the electrical configuration of area A of FIG. 1 according to one embodiment of the present invention.
FIG. 3 is a graph showing the fundamental wave current of an electrical configuration according to one embodiment of the present invention.
FIG. 4 is a diagram showing an electrical equivalent circuit according to one embodiment of the present invention.

The detailed description of the present invention set forth below refers to the accompanying drawings which illustrate, by way of example, specific embodiments in which the invention may be practiced. It should be understood that the various embodiments of the present invention, while different from one another, are not necessarily mutually exclusive. For example, specific shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention. It should also be understood that the positions or arrangements of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the invention. Accordingly, the detailed description set forth below is not intended to be limiting, and the scope of the invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly so described. In the drawings, like reference numerals designate the same or similar functions throughout, and lengths, areas, thicknesses, and the like may be exaggerated for convenience.

The combination of each block of the attached configuration diagram (block diagram) and each step of the flowchart in the present invention can be performed by computer program instructions. Each block or each step can represent a module, segment, or part of code that includes one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative embodiments, the functions mentioned in the blocks or steps may occur out of order. For example, two blocks or steps that are depicted adjacent or in sequence may in fact be performed substantially simultaneously, or the blocks or steps may be performed in reverse order depending on the corresponding function.

It should also be understood that the positions or arrangements of individual components within each published embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the following detailed description is not intended to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims, along with the full scope equivalents to which such claims are entitled, if properly described. In addition, similar reference numerals in the drawings designate the same or similar functions throughout the several aspects, and the shapes thereof may be exaggerated for convenience.

Meanwhile, the terms used in the present invention are terms used to appropriately express preferred embodiments of the present invention, and this may vary depending on the user's intention or the customs of the field to which the present invention belongs. Therefore, the definitions of these terms should be understood based on the contents throughout this specification. When it is said that a certain part "includes" a certain component throughout the specification, this does not mean that other components are excluded, but rather that other components may be further included, unless specifically stated otherwise. In addition, terms such as "module" described in the specification mean a unit that processes at least one function or operation, and this may be implemented as a mechanism, device, hardware or software, or implemented as a combination of hardware and software.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings so that a person skilled in the art to which the present invention pertains can easily practice the present invention.

System configuration

FIG. 1 is a drawing showing the overall configuration of a leak detection system based on a current density distribution according to one embodiment of the present invention.

Referring to FIG. 1, the entire system according to one embodiment of the present invention may be configured to include a communication network (100), a rectifier (200), a measurement module (300), and an administrator terminal device (400).

First, a communication network (100) according to one embodiment of the present invention is a network capable of performing a series of data transmission and reception operations for data reception and control signal transmission between a rectifier (200), a measurement module (300), and a manager terminal device (400), and can be configured regardless of the communication mode, such as wired and/or wireless.

More specifically, it may be any one of a Local Area Network (LAN), a Metropolitan Area Network (MAN), a Wide Area Network (WAN), an Integrated Services Digital Network (ISDN), a wireless LAN, a mobile communication network, Wireless Fidelity, Bluetooth, ZigBee, etc., or various types of wired/wireless communication networks that can be configured by connecting a combination of these, but this is only an example, and the present invention is not limited thereto, and known communication technologies may be adopted and used without limitation.

Next, a rectifier (200) according to one embodiment of the present invention may be a device that can apply different frequencies of harmonic waves by AC power (e.g., high-frequency power) and low-frequency waves by DC power between a metal structure (10) buried in the ground (G) and an insoluble anode (20), thereby allowing a rectifying current to flow from the insoluble anode (20) to the metal structure (10).

More specifically, such a rectifier (200) can apply different frequencies of harmonic waves by AC power (e.g., high-frequency power) and low-frequency waves by DC power so that a method current can flow between a metal structure (10) buried in the ground (G) and an insoluble anode (20). At this time, the metal structure (10) can be a metal pipe buried underground such as a water pipe, a gas pipe, or an oil pipeline, and a liquid (e.g., tap water, etc.) or a gas (e.g., gas, etc.) can be transported inside. In order to prevent the phenomenon of the metal structure (10) being cationized and corroded by a chemical reaction, the current can be controlled by artificially supplying electrons. In the present invention, by applying different frequencies of harmonic waves by AC power (e.g., high-frequency power) and low-frequency waves by DC power, the current can be controlled by the low frequency, and the density distribution of the current can be controlled by the harmonic waves.

Meanwhile, an insoluble anode (20) is placed near a metal structure (10), and a (+) pole of a direct current power source of a predetermined size is connected, and a (-) pole is connected to the metal structure (10), so that a method current can flow to the metal structure through the soil of the electrolyte. At this time, the insoluble anode (20) can be, for example, HSCI (High Silicon Cast Iron), which is a high silicon cast iron.

Next, the measuring module (300) according to one embodiment of the present invention may be a device that can measure the corresponding method current density distribution according to the measuring position on the metal structure (10) by comparing the magnitude of the potential of the reference electrode (30) buried in the ground (G) and the metal structure (10).

More specifically, since corrosion occurs at the point where current flows out from the metal surface of the metal structure (10) through the electrolyte, soil, it is preferable to bury the reference electrode (30) near the metal structure (10). For example, by connecting the (+) terminal to a metal pipe (e.g., a water pipe) buried in the ground (G) and connecting the (-) terminal to the reference electrode (30), the reference potential and the calculated potential value can be compared. At this time, by comparing the potential sizes of the reference electrode (30) and the metal structure (10), the corresponding mode current density distribution according to the measurement position on the metal structure (10), for example, according to the length of the metal pipe, can be measured. The rectifier (200) and the measurement module (300) are arranged at regular intervals on the metal structure (10) to precisely measure the mode current and/or the mode current density distribution.

In addition, the measurement module (300) can detect the harmonic and the fundamental wave of the harmonic applied from the AC power source (e.g., high-frequency power source) of the rectifier (200), and further measure the potential value by the size and phase difference of the harmonic and the fundamental wave. At this time, the harmonic may be the third harmonic of the fundamental wave.

In addition, the measurement module (300) can be configured to measure the ground resistance Ri, which is a parameter through harmonic input applied from the AC power source, which is a high-frequency power source, and the polarization potential layer resistance Rd and potential layer Cd, which are parameters by the DC power source. A more specific description can be understood through the following detailed description with reference to FIGS. 3 and 4.

Next, the manager terminal device (400) according to one embodiment of the present invention may be a device that detects (detects) a corrosion location among the measurement locations of a metal structure (10) based on the above-described method current density distribution, determines the degree of corrosion at the corrosion location based on the potential value by the size and phase difference of the harmonic wave and the fundamental wave, and provides a function of detecting a leak of a liquid or gas transported into the inside of the metal structure (10).

More specifically, the manager terminal device (400) can detect the location where corrosion has occurred in the metal structure (10) based on the density distribution of the current flowing from the insoluble anode (20) to the metal structure (10) measured by the measurement module (300).

At this time, among the density values of the corrosion current according to the measurement position of the metal structure (10), the location (P) where corrosion occurred in the metal structure (10) shows a greater density value of the corrosion current than other locations, so it is possible to detect (detect) that corrosion is occurring at the corresponding location of the metal structure (10). That is, as shown in Fig. 1, it can be seen that the measurement location with the largest value of the corrosion current density among the measurement locations (distances) is the location (P) where corrosion occurred.

In addition, the administrator terminal device (400) can detect the harmonic waves and the fundamental waves of the harmonic waves applied from the AC power of the rectifier (200), and determine the degree of corrosion (corrosion progression level) at the corrosion location based on the potential value by the size and phase difference.

In addition, the administrator terminal device (400) can also detect (determine) whether there is a leak of liquid (e.g., tap water, etc.) or gas (e.g., gas, etc.) being transported inside the metal structure (10) based on data on the location and degree of corrosion on the metal structure (10).

The administrator terminal device (400) according to the embodiment of the present invention described above may be a digital device including a function capable of transmitting and receiving data with the above-described rectifier (200) and/or measurement module (300) by connecting through a communication network (100). In addition, the present invention may perform the function of a server that manages (controls) the operation of a plurality of rectifiers (200) and/or a plurality of measurement modules (300).

More specifically, the administrator terminal device (400) is a digital device, and various terminal devices such as all known mobile communication terminal devices, information and communication devices, and multimedia terminal devices can be applied. Specifically, any digital device equipped with memory means and equipped with a microprocessor and having computational capabilities, such as a smart phone, a portable multimedia player (PMP), a personal digital assistant (PDA), a mobile internet device (MID), a tablet computer (Tablet PC), a notebook, a net book, etc., and including wired/wireless communication functions, can be adopted as the administrator terminal device (400) according to the present invention.

In addition, the administrator terminal device (400) may be equipped with a display means capable of displaying method current information, method current density distribution information, measuring device information, metal structure information, and information related thereto according to the present invention. Here, the display means may be composed of a liquid crystal display (LCD), a thin film transistor LCD (TFT-LCD), an organic light emitting diode (OLED), a light emitting diode (LED), an active matrix organic LED (AMOLED), a flexible display, and a three-dimensional display (3 Dimension), etc. At this time, the display means may include a touch screen form, and may perform some or all of the functions of the input means.

In addition, such an administrator terminal device (400) may perform the function of a server, for example, it may include the function of a server that operates an app or web-only program that can control the method current and transmit and receive method current density distribution measurement information by connecting to a rectifier (200) and/or a measurement module (300).

At this time, the administrator terminal device (400) can control the method current by controlling the power applied from one or more rectifiers (200), and can collect measurement information including the method current density distribution measured from one or more measurement modules (300), analyze the data pattern according to the intelligent algorithm of the present invention, detect the corrosion location of the metal structure (10), and support the implementation of leak detection by determining the degree of corrosion.

Electrical configuration

In the detailed description below, the configuration and operating characteristics of an electrical method using a rectifier (200) that performs an important function for implementing the present invention will be examined as an example, focusing on area A of FIG. 1 and its equivalent circuit.

FIG. 2 is a drawing showing the electrical configuration of area A of FIG. 1 according to one embodiment of the present invention.

Referring to FIG. 2, in a leak detection system based on a current density distribution according to one embodiment of the present invention, the diagram is an enlarged view of an area A where corrosion of a metal structure (10) buried in the ground (G) has progressed, and shows the configuration and operating characteristics of an electric method capable of preventing corrosion of a metal by artificially supplying electrons to prevent cationization in order to prevent the phenomenon of the metal being cationized and corroded by a chemical reaction.

For example, in the case where tap water is transported inside a pipe through a metal structure (10) as a water pipe, in area A, as described in FIG. 1, a device may be used to apply different frequencies of harmonic waves by AC power (e.g., high-frequency power) and low-frequency waves by DC power between the metal structure (10) and the insoluble anode (20) by a rectifier (200), thereby allowing the rectifying current to flow from the insoluble anode (20) to the metal structure (10).

At this time, the cathode reaction can show an electric reaction of 2H ⁺ + 2e ^- => H2, and the anode reaction can show an electric reaction of Fe => Fe2 ⁺ + 2e ^- . Therefore, metal ions including H2 and Fe2 ⁺ can be dissolved into the electrolyte soil (G), and an electric current can flow by electrical method.

Next, in a leak detection system based on a current density distribution according to an embodiment of the present invention, parameters can be detected through harmonic input by an AC power source between a metal structure (10) buried in the ground (G) and an insoluble anode (20). First, if the parameter is measured by a high-frequency power source as a method of estimating the ground resistance Ri of the ground (G), the battery impedance can be expressed as Ri when the frequency is infinite due to the impedance trajectory.

However, since infinite power configuration is impossible in reality, in the present invention, Ri can be detected by applying high-frequency power whose capacitive impedance approaches zero (0). Assuming that the capacitive impedance of this power frequency is a large frequency approaching zero (0), the fundamental current can be defined as in the mathematical equations below. At this time, FIG. 3 is a graph showing the fundamental current of the electrical configuration according to one embodiment of the present invention.

[Mathematical formula 1]

The above mathematical expression 1 is an equation representing the relationship between the sinusoidal voltage and current and the instantaneous power P(t) of Fig. 3.

[Mathematical formula 2]

The above mathematical expression 2 is an equation representing the relationship between the maximum (max) and minimum (min) values of the active power P1 and the instantaneous power P(t) of Fig. 3.

[Mathematical Formula 3]

The above mathematical expression 3 is an equation representing the relationship between the maximum (max) and minimum (min) values of the apparent power VA1 and the instantaneous power P(t) of Fig. 3.

[Mathematical formula 4]

₁를 나타내는 수식이다.The above mathematical expression 4 is the phase difference between the reactive power Q ₁ obtained from the above mathematical expressions 2 and 3.

This is a formula representing ₁ .

Next, FIG. 4 is a diagram showing an electrical equivalent circuit according to one embodiment of the present invention.

Referring to FIG. 4, in a leak detection system based on a current density distribution according to an embodiment of the present invention, Rd is a polarization potential layer resistance, which is a parameter by the DC power source, Cd is a potential layer, and Ri may mean a ground resistance, which is a parameter through a harmonic input applied from the AC power source, which is a high-frequency power source. At this time, if the Ri parameter is measured from the high-frequency power source, the voltage of the low-frequency capacitor by the DC power source may be defined as in the following mathematical equations.

[Mathematical Formula 5]

The above mathematical expression 5 is an equation representing the voltage v for measuring the Ri parameter in the high-frequency power supply of Fig. 4.

[Mathematical Formula 6]

The above mathematical expression 6 is an equation representing the current i for measuring the Ri parameter in the high-frequency power supply of Fig. 4.

[Mathematical formula 7]

The above mathematical expression 7 is an equation representing the voltage v of a low-frequency capacitor by a DC power source based on the Ri parameter measurement of Fig. 4.

In this way, if the current (i ₁ ) is expanded using a Fourier series based on the capacitor voltage phase, it can be separated into an active current component flowing in the resistor that is in phase with the capacitor voltage and a reactive component that is 90° out of phase with the capacitor voltage. At this time, the polarization potential layer resistance Rd and the potential layer Cd by the DC power can be defined as in the following mathematical formula.

[Mathematical formula 8]

The above mathematical expression 8 is an equation representing the effective current i(t) flowing through the resistor that is in phase with the capacitor voltage of Fig. 4.

[Mathematical formula 9]

The above mathematical expression 9 is an equation representing the current id(t) flowing in the polarization potential layer resistance Rd of Fig. 4.

[Mathematical formula 10]

The above mathematical expression 10 is an equation representing the current iq(t) flowing in the potential layer Cd of Fig. 4.

[Mathematical Formula 11]

The above mathematical expression 11 is an equation representing the parameters Rd, which is the polarization potential layer resistance by the DC power source, and Cd, which is the potential layer, calculated by the low-frequency active/inactive current classification of Fig. 4.

Therefore, according to the present invention, there is an effect of being able to measure the current density distribution in a metal structure (e.g., a water pipe) by applying different frequencies of harmonic waves by an AC power source (e.g., a high-frequency power source) and low frequencies by a DC power source.

In addition, based on the current density distribution value that changes when corrosion occurs, it is possible to detect the location of corrosion occurrence, and by detecting the harmonic waves applied from the AC power source and the fundamental wave of the harmonic waves, it is possible to expect the effect of being able to detect leakage (e.g., water leakage) in a metal structure by determining the degree of corrosion (corrosion state) based on the potential value by the size and phase difference.

Although the detailed description of the present invention has been described with specific details such as specific components and limited embodiments and drawings, this has been provided only to help a more general understanding of the present invention, and the present invention is not limited to the above embodiments, and those with ordinary knowledge in the technical field to which the present invention pertains can attempt various modifications and variations from this description. Therefore, the spirit of the present invention is not limited to the embodiments described above, and not only the claims described below but also all things that are equally or equivalently modified by the claims are considered to belong to the scope of the spirit of the present invention.

G: Mediterranean
10: Metal structures
20: Insoluble anode
30: Reference electrode
100: Communication network
200: Rectifier
300: Measurement module
400: Administrator terminal

Claims (5)

A rectifier that applies different frequencies of harmonic waves by AC power and low frequencies by DC power between a metal structure buried in the ground and an insoluble anode, thereby causing a rectifying current to flow from the insoluble anode to the metal structure; and
It includes a measuring module that compares the magnitude of the potential of the reference electrode buried in the ground and the metal structure, and measures the corresponding method current density distribution according to the measuring position on the metal structure.
The above measurement module,
A leak detection system characterized in that it detects the harmonic and the fundamental wave of the harmonic applied from the AC power of the rectifier, and further measures the potential value by the magnitude and phase difference of the harmonic and the fundamental wave.
In the first paragraph,
Based on the above method current density distribution, the corrosion location is detected among the above measurement locations of the metal structure,
A management terminal device that detects leakage of liquid or gas transported inside the metal structure by determining the degree of corrosion at the corrosion location based on the potential value by the magnitude and phase difference of the harmonic and fundamental waves
A leak detection system characterized by further comprising:
In the first paragraph,
The above rectifier is,
The above method controls the current by the low frequency,
A leak detection system characterized in that the density distribution of the above-described method current is controlled by the above-described harmonic, and the above-described harmonic is the third harmonic of the above-described fundamental wave.
In the first paragraph,
The above measurement module,
A leak detection system characterized in that it is configured to measure the ground resistance Ri, which is a parameter through harmonic input applied from the high-frequency power source, which is the AC power source, and the polarization potential layer resistance Rd and the potential layer Cd, which are parameters by the DC power source.
In the first paragraph,
A leak detection system, characterized in that the above rectifier and the above measuring module are arranged at regular intervals on the metal structure.