KR102509172B1 - Corrosion monitoring sensor using electrochemical noise and corrosion monitoring device using the same - Google Patents

Abstract

The present invention relates to a corrosion monitoring sensor using electrochemical noise and a corrosion monitoring device using the same. In the corrosion monitoring sensor using electrochemical noise according to an embodiment of the present invention, voltage and current are measured in an electrochemical reaction for a target structure. a sensing unit for sensing a change over time; and a signal processing unit for measuring voltage and current signals using the sensing result.

Description

Corrosion monitoring sensor using electrochemical noise and corrosion monitoring device using the same

The present invention relates to a corrosion monitoring sensor using electrochemical noise and a corrosion monitoring device using the same. It relates to a corrosion monitoring sensor using electrochemical noise and a corrosion monitoring device using the same for deriving noise resistance and corrosion rate.

In general, 'biomass' refers to living organisms such as plants, animals, and microorganisms that can be used as chemical energy, that is, an energy source of bioenergy, and biomass fuel is a gas, liquid, It refers to fuels in solid form, such as bioethanol, biodiesel, and biojet fuel.

In a boiler furnace using biomass fuel, a serious corrosion problem occurs due to a combustion environment different from the combustion characteristics of a conventional coal boiler furnace.

In other words, these biomass fuels are cheaper than fossil fuels, but have a low combustion rate, high moisture content, various chemical compositions, and a large amount of alkali chlorides are discharged into the combustion gas during combustion. This can cause problems and significantly increase maintenance costs.

Existing corrosion detection methods are mainly indirect methods of measuring resistance to corrosion using a transducer made of the same material as the structure or steel to be measured, or estimating resistance to corrosion by measuring environmental factors in which the structure or steel is placed. used

However, in this method, even if the transducer is made of a material such as a structure or steel, the state of the material is different depending on the exposed environment, so it is impossible to accurately measure corrosion resistance, and there is a limit in that it is difficult to measure corrosion resistance in real time.

Therefore, the existing corrosion detection method requires a technology capable of directly measuring corrosion information in real time and providing the result.

Republic of Korea Patent Registration No. 10-1207612 (registered on November 27, 2012)

An object of the present invention is a corrosion monitoring sensor using electrochemical noise for deriving noise resistance and corrosion rate for a target structure in real time by measuring electrochemical noise by directly contacting the target structure and detecting voltage and current signals, and It is to provide a corrosion monitoring device using the same.

A corrosion monitoring sensor using electrochemical noise according to an embodiment of the present invention includes a sensing unit for sensing changes in voltage and current over time in an electrochemical reaction for a target structure; and a signal processing unit for measuring voltage and current signals using the sensing result.

The sensing part may include an electrolyte area part filled with an electrolyte solution for an electrochemical reaction; electrodes inserted into the electrolyte solution to sense changes in voltage and current over time; and a membrane member for exchanging electrolyte ions between the electrolyte solution and the target structure.

The electrode may be any one of platinum (pt), carbon rod, saturated calomel electrode (SCE), and silver/silver chloride electrode (Ag-AgCl electrode).

The membrane member is a polyvinylidene fluoride-hexafluoropropylene (PolyVinylidene Fluoride-HexaFluoroPropyl, PVdF-HFP) copolymer, polyvinylidene fluoride, polysulfone, polyether sulfone, poly PolyTera FluoroEthylene (PTFE), polyethylene, polycarbonate, polypropylene, polyvinylalcohol, polyphenylene sulfide, cellulose actate ), polyamide (polyamide), polyacrylonitrile (polyacrylonitrile), etc. may be one or more selected from the group used.

According to an embodiment, a frame formed by opening a lower surface of the electrolyte area portion and sealed by the membrane member; and a frame stopper for fixing the membrane member to the frame.

The frame may be any one of Teflon, epoxy resin, and rubber materials.

The sensing unit and the signal processing unit may be electrically connected to each other through a pin connector.

According to the embodiment, the sensor case including a case body in which the sensing unit is installed on the upper side and the signal processing unit is installed in the lower side, and a case cover sealing the case body; further comprising, the outer surface of the sensing unit And an O-ring may be inserted between the inner surface of the case body.

In addition, the corrosion monitoring device according to an embodiment of the present invention measures voltage and current signals using a sensing unit for sensing changes over time in voltage and current in an electrochemical reaction for a target structure and the sensing result. Corrosion monitoring sensor including a signal processing unit for; a controller for calculating noise resistance and corrosion rate from the measured voltage and current signals; and an output unit for outputting the calculated noise resistance and corrosion rate.

The control unit may calculate noise resistance using a potential standard deviation and a current standard deviation.

The controller may calculate the corrosion rate by applying the calculated noise resistance to electrochemical Tafel measurement.

The control unit may determine the type of corrosion by calculating a localization index using the measured voltage and current signals.

The present invention can derive noise resistance and corrosion rate of a target structure in real time by directly contacting the target structure and sensing voltage and current signals to measure electrochemical noise.

In addition, the present invention can measure corrosion information in a direct manner in real time and provide the result.

1 is a view showing a corrosion monitoring sensor using electrochemical noise according to an embodiment of the present invention;
2 is a view showing the sensing unit of FIG. 1;
3 is a view showing the signal processing unit of FIG. 1;
4 is a diagram showing voltage and current signals measured in the ZRA of FIG. 3;
5 is a view showing a corrosion monitoring device using a corrosion monitoring sensor according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, detailed descriptions of well-known functions or configurations that may obscure the gist of the present invention will be omitted in the following description and accompanying drawings. In addition, it should be noted that the same components are indicated by the same reference numerals throughout the drawings as much as possible.

The terms or words used in this specification and claims described below should not be construed as being limited to ordinary or dictionary meanings, and the inventors are appropriately defined as terms for describing their invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention. It should be understood that there may be equivalents and variations.

In the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size. The present invention is not limited by the relative sizes or spacings drawn in the accompanying drawings.

When it is said that a certain part "includes" a certain component throughout the specification, it means that it may further include other components without excluding other components unless otherwise stated. In addition, when a part is said to be "connected" to another part, this includes not only the case of being "directly connected" but also the case of being "electrically connected" with another element interposed therebetween.

Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as "comprise" or "having" are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but that one or more other features, numbers, or steps are present. However, it should be understood that it does not preclude the possibility of existence or addition of operations, components, parts, or combinations thereof.

Also, the term "unit" used in the specification means a hardware component such as software, FPGA or ASIC, and "unit" performs certain roles. However, "unit" is not meant to be limited to software or hardware. A “unit” may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Thus, as an example, “unit” can refer to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. Functionality provided within components and "parts" may be combined into fewer components and "parts" or further separated into additional components and "parts".

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a diagram showing a corrosion monitoring sensor using electrochemical noise according to an embodiment of the present invention.

As shown in FIG. 1, a corrosion monitoring sensor (hereinafter referred to as a 'corrosion monitoring sensor') 1 using electrochemical noise according to an embodiment of the present invention detects voltage and current signals by directly contacting a target structure. to measure electrochemical noise.

Here, electrochemical noise refers to a change in current or voltage over time in an electrochemical reaction, and can be analyzed as noise resistance generated during an electrochemical reaction. And, the noise resistance is used to derive the reaction rate (corrosion rate) related to the electrochemical reaction around the electrode.

Meanwhile, in the corrosion monitoring sensor 1, a signal processing unit 30 and a sensing unit 100 electrically interconnected through a pin connector 20 are installed inside the sensor case 10. Here, the signal processing unit 30 and the sensing unit 100 are spaced apart from each other and stacked with the pin connector 20 interposed therebetween.

In addition, since each of the signal processing unit 30 and the sensing unit 100 is connected to each other through the pin connector 20, it is easy to separate and mount for maintenance. At this time, each of the signal processing unit 30 and the sensing unit 100 is connected to the pin connector 20 through a lead wire. The preference processing unit 30 is connected to a communication line for external communication.

Meanwhile, the sensor case 10 has a structure in which the case body 11 and the case cover 12 can be separated and coupled to each other. The case body 11 and the case cover 12 are sealed and coupled through a first o-ring 12a.

First, the signal processing unit 30 is fixed to the hook 11a extending inwardly from the inner surface of the case body 11 . For example, the signal processing unit 30 may be fastened to the hanging jaw 11a through screw coupling.

Next, the sensing unit 100 is assembled to the lower part of the case body 11 and directly contacts the target structure to be measured.

However, external foreign substances may penetrate through gaps that exist when the sensing unit 100 and the case body 11 are assembled together. Accordingly, a second O-ring 40 is inserted between the outer surface of the sensing unit 100 and the inner surface of the case body 11 to prevent intrusion of foreign substances from the outside.

FIG. 2 is a view showing the sensing unit of FIG. 1 .

As shown in FIG. 2 , the sensing unit 100 senses changes over time in voltage and current in an electrochemical reaction for the target structure S for corrosion detection and monitoring.

The sensing unit 100 includes at least one electrolyte region 110 filled with an electrolyte for an electrochemical reaction, a frame 130 for forming the electrolyte region 110, an electrolyte region 110, and a target structure (S). ) and a frame stopper 150 for fixing the membrane member 140 to the frame 130.

First, each of the electrolyte area units 110 is an area having the same volume, and a solution containing an electrolyte (eg, K ⁺ , Na ⁺ , Ca ₂ ⁺ , Mg ₂ ⁺ , Cl ^- , etc.), that is, an electrolyte solution is filled. there is. At this time, any electrolyte may be used as long as it simulates a corrosive environment.

In addition, each of the electrolyte area units 110 is provided with one electrode 120 inserted into the electrolyte solution to detect changes in voltage and current over time.

Here, the electrode 120 is a material with low reactivity that does not affect the electrical signal (eg, platinum (pt), carbon rod, saturated calomel electrode (Saturated Calomel Electrode, SCE), silver / silver chloride) electrode (Ag-AgCl electrode, etc.) is suitable. One end of the electrode 120 is inserted into the solution of the electrolyte region 110, and the other end is connected to a lead wire 121 connected to the pin connector 20. At this time, the lead wire 121 is connected to the other end of the electrode 120 by screwing.

Next, the frame 130 is preferably selected from a material (eg, Teflon, epoxy resin, rubber, etc.) having excellent chemical resistance and water resistance so as not to react with the electrolyte solution filled in the electrolyte area portion 110 .

In particular, the frame 130 has a structure in which the lower surface of the electrolyte region 110 is opened, and is sealed by the membrane member 140 .

Here, the membrane member 140 uses a polymer material having a pore size through which electrolyte ions in the electrolyte solution can move. Polymer materials include PolyVinylidene Fluoride-HexaFluoroPropyl (PVdF-HFP) copolymer, polyvinylidene fluoride, polysulfone, polyether sulfone, polytetra- Fluoroethylene (PolyTera FluoroEthylene, PTFE), polyethylene, polycarbonate, polypropylene, polyvinylalcohol, polyphenylene sulfide, cellulose actate, One or more types are selected from the group consisting of polyamide, polyacrylonitrile, and the like.

The membrane member 140 has a pore size that allows electrolyte ions to react with the target structure S without allowing electrolyte solution to escape. At this time, when the membrane member 140 adheres to the target structure S, electrolyte ions react with the target structure S to generate voltage and current signals. Electrodes 120 sense the generated voltage and current signals.

Then, the membrane member 140 is fixed by the frame stopper 150 as described above. The frame stoppers 150 may be configured as a pair and assembled into a bolt/nut coupling structure 151 .

The frame stopper 150 may have any shape as long as it serves to fix the membrane member 140, and may be made of the same material as the frame 130 or a different material. Like the frame 130, the frame stopper 150 is preferably made of a material having excellent chemical resistance.

3 is a diagram showing the signal processing unit of FIG. 1, and FIG. 4 is a diagram showing voltage and current signals measured in the ZRA of FIG.

Referring to FIG. 3 , the signal processing unit 30 converts voltage and current signals sensed through the sensing unit 100 into digital signals and transmits them to the outside.

The signal processing unit 30 includes a ZRA (Zero Resistance Ameter) sensing unit 31, an amplifier 32, an A/D conversion unit 33, a filter unit 34, and a data communication unit 35.

The ZRA sensing unit 31 may be a non-resistance ammeter that measures voltage and current signals sensed through the electrode 120 .

For example, as shown in FIGS. 1 and 2 , the case where three electrodes 120 are sequentially disposed, that is, a first electrode, a second electrode, and a third electrode, will be described. In this case, the ZRA sensing unit 31 measures a current signal between the first electrode and the second electrode or a voltage signal between the first electrode and the third electrode. The ZRA sensing unit 31 may measure voltage and current signals as shown in FIG. 4 .

The amplifier 32 amplifies the voltage and current signals measured by the ZRA sensing unit 31, and the A/D converter 33 converts the amplified electrical signal into a digital signal. The filter unit 34 filters the converted digital signal, and the data communication unit 35 transfers the filtered digital signal to the outside (control unit 2 to be described later).

5 is a view showing a corrosion monitoring device using a corrosion monitoring sensor according to an embodiment of the present invention.

As shown in FIG. 5, a corrosion monitoring device using a corrosion monitoring sensor according to an embodiment of the present invention includes a corrosion monitoring sensor 1, a control unit 2, a memory 3, and an output unit 4. .

As described above, the corrosion monitoring sensor 1 measures voltage and current signals through corrosion detection and monitoring of the target structure S.

The control unit 2 calculates noise resistance and corrosion rate in real time from the measured voltage and current signals and outputs the results through the output unit 4.

Here, the control unit 2 executes computer readable instructions as at least one processor, the memory 3 stores computer readable instructions, and the output unit 4 outputs an execution result of the computer readable instructions. The controller 2, the memory 3, and the output unit 4 may be components included in a computer, laptop, smart phone, or the like.

Specifically, noise resistance (Rn) is calculated as in Equation 1 below using a potential standard deviation (σ _V ) and a current standard deviation (σ _I ).

Noise resistance Rn can be equated with polarization resistance Rp. The polarization resistance (Rp) is used as the corrosion rate by the general electrochemical Tafel measurement method as shown in Equation 2 below.

Here, β _ox,M is the positive Tafel constant and β _red,C is the negative Tafel constant.

Accordingly, the corrosion rate (mm/year) can be expressed as in Equation 3 below.

Here, EW (Equivalent Weight) can be expressed as ∑f _i M _i / _ni , where f _i is the atomic fraction, M _i is the atomic weight, and n _i is the valence.

In addition, the controller 2 calculates a known localization index for identifying the type of corrosion using the measured voltage and current signals. Through this, the control unit 2 can determine the type of uniform corrosion or localized corrosion. In the case of uniform corrosion, the localization index value becomes 10 ^-3 , and in the case of localized corrosion, it shows a larger value.

Methods according to some embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the medium may be those specially designed and configured for the present invention or those known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CDROMs and DVDs, and magnetic-optical media such as floptical disks. Included are hardware devices specially configured to store and execute program instructions, such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

Although the foregoing description has been focused on the novel features of the present invention as applied to various embodiments, one skilled in the art will be able to understand the above-described apparatus and method without departing from the scope of the present invention. It will be appreciated that various deletions, substitutions, and changes in the form and detail of are possible. Accordingly, the scope of the present invention is defined by the appended claims rather than by the foregoing description. All modifications that come within the scope of equivalence of the claims are embraced by the scope of the present invention.

One ; corrosion monitoring sensor 2 ; control unit
3 ; memory 4 ; output
10; sensor case 11; case body
12; Case cover 12a: first O-ring
20; Pin connector 30 ; signal processing unit
31; ZRA sensing unit 32; amplifier
33; A/D conversion unit 34; filter part
35; data communication unit 40; 2nd O-ring
100; sensing unit 110; electrolyte area
120; electrode 121; lead wire
130; frame 140; membrane member
150; frame stopper S ; target structure

Claims (16)

a sensing unit for sensing changes over time in voltage and current in an electrochemical reaction for a target structure; and
a signal processor for measuring voltage and current signals using the sensing result;
contains
The sensing unit,
an electrolyte area filled with an electrolyte solution for an electrochemical reaction;
electrodes inserted into the electrolyte solution to sense changes in voltage and current over time; and
a membrane member for exchanging electrolyte ions between the electrolyte solution and the target structure;
and
a frame formed by opening a lower surface of the electrolyte region and sealed by the membrane member; and
a frame stopper for fixing the membrane member to the frame;
contains more
The membrane member is a corrosion monitoring sensor using electrochemical noise, characterized in that the electrolyte solution does not escape and has a pore size that allows only the electrolyte ions to react with the target structure.
delete According to claim 1,
the electrode,
Corrosion monitoring sensor using electrochemical noise, which is any one of platinum (pt), carbon rod, saturated calomel electrode (SCE), and silver/silver chloride electrode (Ag-AgCl electrode).
According to claim 1,
The membrane member,
Polyvinylidene Fluoride-HexaFluoroPropyl (PVdF-HFP) copolymer, polyvinylidene fluoride, polysulfone, polyether sulfone, polytetra-fluoroethylene (PolyTera FluoroEthylene, PTFE), polyethylene, polycarbonate, polypropylene, polyvinylalcohol, polyphenylene sulfide, cellulose actate, polyamide ( A corrosion monitoring sensor using electrochemical noise that is selected from the group consisting of polyamide) and polyacrylonitrile.
delete According to claim 1,
the frame,
Corrosion monitoring sensor using electrochemical noise, which is any one of Teflon, epoxy resin, and rubber materials.
According to claim 1,
The sensing unit and the signal processing unit,
A corrosion monitoring sensor using electrochemical noise that is electrically connected to each other through a pin connector.
According to claim 1,
A sensor case including a case body in which the sensing unit is installed on the upper side and the signal processing unit is installed in the lower side, and a case cover sealing the case body; further comprising,
Corrosion monitoring sensor using electrochemical noise in which an O-ring is inserted between the outer surface of the sensing unit and the inner surface of the case body.
A corrosion monitoring sensor including a sensing unit for sensing changes over time in voltage and current in an electrochemical reaction for a target structure and a signal processing unit for measuring voltage and current signals using the sensing result;
a controller for calculating noise resistance and corrosion rate from the measured voltage and current signals; and
an output unit for outputting the calculated noise resistance and corrosion rate;
contains
The sensing unit,
an electrolyte area filled with an electrolyte solution for an electrochemical reaction;
electrodes inserted into the electrolyte solution to sense changes in voltage and current over time; and
a membrane member for exchanging electrolyte ions between the electrolyte solution and the target structure;
and
a frame formed by opening a lower surface of the electrolyte region and sealed by the membrane member; and
a frame stopper for fixing the membrane member to the frame;
contains more
The corrosion monitoring device, characterized in that the membrane member has a pore size that allows only the electrolyte ions to react with the target structure without allowing the electrolyte solution to escape.
According to claim 9,
The control unit,
A corrosion monitoring device wherein noise resistance is calculated using potential standard deviation and current standard deviation.
According to claim 10,
The control unit,
Corrosion monitoring device to calculate the corrosion rate by applying the calculated noise resistance to the electrochemical Tafel measurement method.
According to claim 9,
The control unit,
Corrosion monitoring device to determine the type of corrosion by calculating the localization index using the measured voltage and current signals.
delete delete According to claim 9,
The sensing unit and the signal processing unit,
Corrosion monitoring devices electrically connected to each other via pin connectors.
According to claim 9,
The corrosion monitoring sensor,
A sensor case including a case body in which the sensing unit is installed on an upper side and the signal processing unit is installed in a lower side, and a case cover sealing the case body;
Corrosion monitoring device wherein an O-ring is inserted between the outer surface of the sensing unit and the inner surface of the case body.

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